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* [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework
@ 2019-07-12  8:17 Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 01/18] kunit: test: add KUnit test runner core Brendan Higgins
                   ` (17 more replies)
  0 siblings, 18 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins, Michal Marek, Jonathan Corbet, Iurii Zaikin

## TL;DR

This new patch set only contains a very minor change to address a sparse
warning in the PROC SYSCTL KUnit test. Otherwise this patchset is
identical to the previous.

As I mentioned in the previous patchset, all patches now have acks and
reviews.

## Background

This patch set proposes KUnit, a lightweight unit testing and mocking
framework for the Linux kernel.

Unlike Autotest and kselftest, KUnit is a true unit testing framework;
it does not require installing the kernel on a test machine or in a VM
(however, KUnit still allows you to run tests on test machines or in VMs
if you want[1]) and does not require tests to be written in userspace
running on a host kernel. Additionally, KUnit is fast: From invocation
to completion KUnit can run several dozen tests in about a second.
Currently, the entire KUnit test suite for KUnit runs in under a second
from the initial invocation (build time excluded).

KUnit is heavily inspired by JUnit, Python's unittest.mock, and
Googletest/Googlemock for C++. KUnit provides facilities for defining
unit test cases, grouping related test cases into test suites, providing
common infrastructure for running tests, mocking, spying, and much more.

### What's so special about unit testing?

A unit test is supposed to test a single unit of code in isolation,
hence the name. There should be no dependencies outside the control of
the test; this means no external dependencies, which makes tests orders
of magnitudes faster. Likewise, since there are no external dependencies,
there are no hoops to jump through to run the tests. Additionally, this
makes unit tests deterministic: a failing unit test always indicates a
problem. Finally, because unit tests necessarily have finer granularity,
they are able to test all code paths easily solving the classic problem
of difficulty in exercising error handling code.

### Is KUnit trying to replace other testing frameworks for the kernel?

No. Most existing tests for the Linux kernel are end-to-end tests, which
have their place. A well tested system has lots of unit tests, a
reasonable number of integration tests, and some end-to-end tests. KUnit
is just trying to address the unit test space which is currently not
being addressed.

### More information on KUnit

There is a bunch of documentation near the end of this patch set that
describes how to use KUnit and best practices for writing unit tests.
For convenience I am hosting the compiled docs here[2].

Additionally for convenience, I have applied these patches to a
branch[3]. The repo may be cloned with:
git clone https://kunit.googlesource.com/linux
This patchset is on the kunit/rfc/v5.2/v9 branch.

## Changes Since Last Version

Like I said in the TL;DR, there is only one minor change since the
previous revision. That change only affects patch 17/18; it addresses a
sparse warning in the PROC SYSCTL unit test.

Thanks to Masahiro for applying previous patches to a branch in his
kbuild tree and running sparse and other static analysis tools against
my patches.

[1] https://google.github.io/kunit-docs/third_party/kernel/docs/usage.html#kunit-on-non-uml-architectures
[2] https://google.github.io/kunit-docs/third_party/kernel/docs/
[3] https://kunit.googlesource.com/linux/+/kunit/rfc/v5.2/v9

-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 01/18] kunit: test: add KUnit test runner core
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-15 20:10   ` Stephen Boyd
  2019-07-12  8:17 ` [PATCH v9 02/18] kunit: test: add test resource management API Brendan Higgins
                   ` (16 subsequent siblings)
  17 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add core facilities for defining unit tests; this provides a common way
to define test cases, functions that execute code which is under test
and determine whether the code under test behaves as expected; this also
provides a way to group together related test cases in test suites (here
we call them test_modules).

Just define test cases and how to execute them for now; setting
expectations on code will be defined later.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
---
 include/kunit/test.h | 179 ++++++++++++++++++++++++++++++++++++++++
 kunit/Kconfig        |  17 ++++
 kunit/Makefile       |   1 +
 kunit/test.c         | 189 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 386 insertions(+)
 create mode 100644 include/kunit/test.h
 create mode 100644 kunit/Kconfig
 create mode 100644 kunit/Makefile
 create mode 100644 kunit/test.c

diff --git a/include/kunit/test.h b/include/kunit/test.h
new file mode 100644
index 0000000000000..e0b34acb9ee4e
--- /dev/null
+++ b/include/kunit/test.h
@@ -0,0 +1,179 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Base unit test (KUnit) API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_TEST_H
+#define _KUNIT_TEST_H
+
+#include <linux/types.h>
+
+struct kunit;
+
+/**
+ * struct kunit_case - represents an individual test case.
+ * @run_case: the function representing the actual test case.
+ * @name: the name of the test case.
+ *
+ * A test case is a function with the signature, ``void (*)(struct kunit *)``
+ * that makes expectations (see KUNIT_EXPECT_TRUE()) about code under test. Each
+ * test case is associated with a &struct kunit_suite and will be run after the
+ * suite's init function and followed by the suite's exit function.
+ *
+ * A test case should be static and should only be created with the KUNIT_CASE()
+ * macro; additionally, every array of test cases should be terminated with an
+ * empty test case.
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ *	void add_test_basic(struct kunit *test)
+ *	{
+ *		KUNIT_EXPECT_EQ(test, 1, add(1, 0));
+ *		KUNIT_EXPECT_EQ(test, 2, add(1, 1));
+ *		KUNIT_EXPECT_EQ(test, 0, add(-1, 1));
+ *		KUNIT_EXPECT_EQ(test, INT_MAX, add(0, INT_MAX));
+ *		KUNIT_EXPECT_EQ(test, -1, add(INT_MAX, INT_MIN));
+ *	}
+ *
+ *	static struct kunit_case example_test_cases[] = {
+ *		KUNIT_CASE(add_test_basic),
+ *		{}
+ *	};
+ *
+ */
+struct kunit_case {
+	void (*run_case)(struct kunit *test);
+	const char *name;
+
+	/* private: internal use only. */
+	bool success;
+};
+
+/**
+ * KUNIT_CASE - A helper for creating a &struct kunit_case
+ * @test_name: a reference to a test case function.
+ *
+ * Takes a symbol for a function representing a test case and creates a
+ * &struct kunit_case object from it. See the documentation for
+ * &struct kunit_case for an example on how to use it.
+ */
+#define KUNIT_CASE(test_name) { .run_case = test_name, .name = #test_name }
+
+/**
+ * struct kunit_suite - describes a related collection of &struct kunit_case s.
+ * @name: the name of the test. Purely informational.
+ * @init: called before every test case.
+ * @exit: called after every test case.
+ * @test_cases: a null terminated array of test cases.
+ *
+ * A kunit_suite is a collection of related &struct kunit_case s, such that
+ * @init is called before every test case and @exit is called after every test
+ * case, similar to the notion of a *test fixture* or a *test class* in other
+ * unit testing frameworks like JUnit or Googletest.
+ *
+ * Every &struct kunit_case must be associated with a kunit_suite for KUnit to
+ * run it.
+ */
+struct kunit_suite {
+	const char name[256];
+	int (*init)(struct kunit *test);
+	void (*exit)(struct kunit *test);
+	struct kunit_case *test_cases;
+};
+
+/**
+ * struct kunit - represents a running instance of a test.
+ * @priv: for user to store arbitrary data. Commonly used to pass data created
+ * in the init function (see &struct kunit_suite).
+ *
+ * Used to store information about the current context under which the test is
+ * running. Most of this data is private and should only be accessed indirectly
+ * via public functions; the one exception is @priv which can be used by the
+ * test writer to store arbitrary data.
+ */
+struct kunit {
+	void *priv;
+
+	/* private: internal use only. */
+	const char *name; /* Read only after initialization! */
+	/*
+	 * success starts as true, and may only be set to false during a test
+	 * case; thus, it is safe to update this across multiple threads using
+	 * WRITE_ONCE; however, as a consequence, it may only be read after the
+	 * test case finishes once all threads associated with the test case
+	 * have terminated.
+	 */
+	bool success; /* Read only after test_case finishes! */
+};
+
+void kunit_init_test(struct kunit *test, const char *name);
+
+int kunit_run_tests(struct kunit_suite *suite);
+
+/**
+ * kunit_test_suite() - used to register a &struct kunit_suite with KUnit.
+ * @suite: a statically allocated &struct kunit_suite.
+ *
+ * Registers @suite with the test framework. See &struct kunit_suite for more
+ * information.
+ *
+ * NOTE: Currently KUnit tests are all run as late_initcalls; this means that
+ * they cannot test anything where tests must run at a different init phase. One
+ * significant restriction resulting from this is that KUnit cannot reliably
+ * test anything that is initialize in the late_init phase; another is that
+ * KUnit is useless to test things that need to be run in an earlier init phase.
+ */
+#define kunit_test_suite(suite)						       \
+		/*
+		 * TODO(brendanhiggins@google.com): Don't run all KUnit tests as
+		 * late_initcalls.  I have some future work planned to dispatch
+		 * all KUnit tests from the same place, and at the very least to
+		 * do so after everything else is definitely initialized.
+		 */							       \
+		static int kunit_suite_init##suite(void)		       \
+		{							       \
+			return kunit_run_tests(&suite);			       \
+		}							       \
+		late_initcall(kunit_suite_init##suite)
+
+void __printf(3, 4) kunit_printk(const char *level,
+				 const struct kunit *test,
+				 const char *fmt, ...);
+
+/**
+ * kunit_info() - Prints an INFO level message associated with the current test.
+ * @test: The test context object.
+ * @fmt: A printk() style format string.
+ *
+ * Prints an info level message associated with the test suite being run. Takes
+ * a variable number of format parameters just like printk().
+ */
+#define kunit_info(test, fmt, ...) \
+		kunit_printk(KERN_INFO, test, fmt, ##__VA_ARGS__)
+
+/**
+ * kunit_warn() - Prints a WARN level message associated with the current test.
+ * @test: The test context object.
+ * @fmt: A printk() style format string.
+ *
+ * Prints a warning level message.
+ */
+#define kunit_warn(test, fmt, ...) \
+		kunit_printk(KERN_WARNING, test, fmt, ##__VA_ARGS__)
+
+/**
+ * kunit_err() - Prints an ERROR level message associated with the current test.
+ * @test: The test context object.
+ * @fmt: A printk() style format string.
+ *
+ * Prints an error level message.
+ */
+#define kunit_err(test, fmt, ...) \
+		kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)
+
+#endif /* _KUNIT_TEST_H */
diff --git a/kunit/Kconfig b/kunit/Kconfig
new file mode 100644
index 0000000000000..330ae83527c23
--- /dev/null
+++ b/kunit/Kconfig
@@ -0,0 +1,17 @@
+#
+# KUnit base configuration
+#
+
+menu "KUnit support"
+
+config KUNIT
+	bool "Enable support for unit tests (KUnit)"
+	help
+	  Enables support for kernel unit tests (KUnit), a lightweight unit
+	  testing and mocking framework for the Linux kernel. These tests are
+	  able to be run locally on a developer's workstation without a VM or
+	  special hardware when using UML. Can also be used on most other
+	  architectures. For more information, please see
+	  Documentation/dev-tools/kunit/.
+
+endmenu
diff --git a/kunit/Makefile b/kunit/Makefile
new file mode 100644
index 0000000000000..5efdc4dea2c08
--- /dev/null
+++ b/kunit/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_KUNIT) +=			test.o
diff --git a/kunit/test.c b/kunit/test.c
new file mode 100644
index 0000000000000..571e4c65deb5c
--- /dev/null
+++ b/kunit/test.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Base unit test (KUnit) API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <linux/kernel.h>
+#include <kunit/test.h>
+
+static void kunit_set_failure(struct kunit *test)
+{
+	WRITE_ONCE(test->success, false);
+}
+
+static int kunit_vprintk_emit(int level, const char *fmt, va_list args)
+{
+	return vprintk_emit(0, level, NULL, 0, fmt, args);
+}
+
+static int kunit_printk_emit(int level, const char *fmt, ...)
+{
+	va_list args;
+	int ret;
+
+	va_start(args, fmt);
+	ret = kunit_vprintk_emit(level, fmt, args);
+	va_end(args);
+
+	return ret;
+}
+
+static void kunit_vprintk(const struct kunit *test,
+			  const char *level,
+			  struct va_format *vaf)
+{
+	kunit_printk_emit(level[1] - '0', "\t# %s: %pV", test->name, vaf);
+}
+
+static void kunit_print_tap_version(void)
+{
+	static bool kunit_has_printed_tap_version;
+
+	if (!kunit_has_printed_tap_version) {
+		kunit_printk_emit(LOGLEVEL_INFO, "TAP version 14\n");
+		kunit_has_printed_tap_version = true;
+	}
+}
+
+static size_t kunit_test_cases_len(struct kunit_case *test_cases)
+{
+	struct kunit_case *test_case;
+	size_t len = 0;
+
+	for (test_case = test_cases; test_case->run_case; test_case++)
+		len++;
+
+	return len;
+}
+
+static void kunit_print_subtest_start(struct kunit_suite *suite)
+{
+	kunit_print_tap_version();
+	kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", suite->name);
+	kunit_printk_emit(LOGLEVEL_INFO,
+			  "\t1..%zd\n",
+			  kunit_test_cases_len(suite->test_cases));
+}
+
+static void kunit_print_ok_not_ok(bool should_indent,
+				  bool is_ok,
+				  size_t test_number,
+				  const char *description)
+{
+	const char *indent, *ok_not_ok;
+
+	if (should_indent)
+		indent = "\t";
+	else
+		indent = "";
+
+	if (is_ok)
+		ok_not_ok = "ok";
+	else
+		ok_not_ok = "not ok";
+
+	kunit_printk_emit(LOGLEVEL_INFO,
+			  "%s%s %zd - %s\n",
+			  indent, ok_not_ok, test_number, description);
+}
+
+static bool kunit_suite_has_succeeded(struct kunit_suite *suite)
+{
+	const struct kunit_case *test_case;
+
+	for (test_case = suite->test_cases; test_case->run_case; test_case++)
+		if (!test_case->success)
+			return false;
+
+	return true;
+}
+
+static void kunit_print_subtest_end(struct kunit_suite *suite)
+{
+	static size_t kunit_suite_counter = 1;
+
+	kunit_print_ok_not_ok(false,
+			      kunit_suite_has_succeeded(suite),
+			      kunit_suite_counter++,
+			      suite->name);
+}
+
+static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
+					    size_t test_number)
+{
+	kunit_print_ok_not_ok(true,
+			      test_case->success,
+			      test_number,
+			      test_case->name);
+}
+
+void kunit_init_test(struct kunit *test, const char *name)
+{
+	test->name = name;
+	test->success = true;
+}
+
+/*
+ * Performs all logic to run a test case.
+ */
+static void kunit_run_case(struct kunit_suite *suite,
+			   struct kunit_case *test_case)
+{
+	struct kunit test;
+	int ret = 0;
+
+	kunit_init_test(&test, test_case->name);
+
+	if (suite->init) {
+		ret = suite->init(&test);
+		if (ret) {
+			kunit_err(&test, "failed to initialize: %d\n", ret);
+			kunit_set_failure(&test);
+			return;
+		}
+	}
+
+	test_case->run_case(&test);
+
+	if (suite->exit)
+		suite->exit(&test);
+
+	test_case->success = test.success;
+}
+
+int kunit_run_tests(struct kunit_suite *suite)
+{
+	struct kunit_case *test_case;
+	size_t test_case_count = 1;
+
+	kunit_print_subtest_start(suite);
+
+	for (test_case = suite->test_cases; test_case->run_case; test_case++) {
+		kunit_run_case(suite, test_case);
+		kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
+	}
+
+	kunit_print_subtest_end(suite);
+
+	return 0;
+}
+
+void kunit_printk(const char *level,
+		  const struct kunit *test,
+		  const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	kunit_vprintk(test, level, &vaf);
+
+	va_end(args);
+}
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 02/18] kunit: test: add test resource management API
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 01/18] kunit: test: add KUnit test runner core Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-15 20:24   ` Stephen Boyd
  2019-07-12  8:17 ` [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder Brendan Higgins
                   ` (15 subsequent siblings)
  17 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Create a common API for test managed resources like memory and test
objects. A lot of times a test will want to set up infrastructure to be
used in test cases; this could be anything from just wanting to allocate
some memory to setting up a driver stack; this defines facilities for
creating "test resources" which are managed by the test infrastructure
and are automatically cleaned up at the conclusion of the test.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 include/kunit/test.h | 116 +++++++++++++++++++++++++++++++++++++++++++
 kunit/test.c         |  94 +++++++++++++++++++++++++++++++++++
 2 files changed, 210 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index e0b34acb9ee4e..bdf41d31c343c 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -10,6 +10,70 @@
 #define _KUNIT_TEST_H
 
 #include <linux/types.h>
+#include <linux/slab.h>
+
+struct kunit_resource;
+
+typedef int (*kunit_resource_init_t)(struct kunit_resource *, void *);
+typedef void (*kunit_resource_free_t)(struct kunit_resource *);
+
+/**
+ * struct kunit_resource - represents a *test managed resource*
+ * @allocation: for the user to store arbitrary data.
+ * @free: a user supplied function to free the resource. Populated by
+ * kunit_alloc_resource().
+ *
+ * Represents a *test managed resource*, a resource which will automatically be
+ * cleaned up at the end of a test case.
+ *
+ * Example:
+ *
+ * .. code-block:: c
+ *
+ *	struct kunit_kmalloc_params {
+ *		size_t size;
+ *		gfp_t gfp;
+ *	};
+ *
+ *	static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
+ *	{
+ *		struct kunit_kmalloc_params *params = context;
+ *		res->allocation = kmalloc(params->size, params->gfp);
+ *
+ *		if (!res->allocation)
+ *			return -ENOMEM;
+ *
+ *		return 0;
+ *	}
+ *
+ *	static void kunit_kmalloc_free(struct kunit_resource *res)
+ *	{
+ *		kfree(res->allocation);
+ *	}
+ *
+ *	void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
+ *	{
+ *		struct kunit_kmalloc_params params;
+ *		struct kunit_resource *res;
+ *
+ *		params.size = size;
+ *		params.gfp = gfp;
+ *
+ *		res = kunit_alloc_resource(test, kunit_kmalloc_init,
+ *			kunit_kmalloc_free, &params);
+ *		if (res)
+ *			return res->allocation;
+ *
+ *		return NULL;
+ *	}
+ */
+struct kunit_resource {
+	void *allocation;
+	kunit_resource_free_t free;
+
+	/* private: internal use only. */
+	struct list_head node;
+};
 
 struct kunit;
 
@@ -109,6 +173,13 @@ struct kunit {
 	 * have terminated.
 	 */
 	bool success; /* Read only after test_case finishes! */
+	struct mutex lock; /* Gaurds all mutable test state. */
+	/*
+	 * Because resources is a list that may be updated multiple times (with
+	 * new resources) from any thread associated with a test case, we must
+	 * protect it with some type of lock.
+	 */
+	struct list_head resources; /* Protected by lock. */
 };
 
 void kunit_init_test(struct kunit *test, const char *name);
@@ -141,6 +212,51 @@ int kunit_run_tests(struct kunit_suite *suite);
 		}							       \
 		late_initcall(kunit_suite_init##suite)
 
+/**
+ * kunit_alloc_resource() - Allocates a *test managed resource*.
+ * @test: The test context object.
+ * @init: a user supplied function to initialize the resource.
+ * @free: a user supplied function to free the resource.
+ * @context: for the user to pass in arbitrary data to the init function.
+ *
+ * Allocates a *test managed resource*, a resource which will automatically be
+ * cleaned up at the end of a test case. See &struct kunit_resource for an
+ * example.
+ */
+struct kunit_resource *kunit_alloc_resource(struct kunit *test,
+					    kunit_resource_init_t init,
+					    kunit_resource_free_t free,
+					    void *context);
+
+void kunit_free_resource(struct kunit *test, struct kunit_resource *res);
+
+/**
+ * kunit_kmalloc() - Like kmalloc() except the allocation is *test managed*.
+ * @test: The test context object.
+ * @size: The size in bytes of the desired memory.
+ * @gfp: flags passed to underlying kmalloc().
+ *
+ * Just like `kmalloc(...)`, except the allocation is managed by the test case
+ * and is automatically cleaned up after the test case concludes. See &struct
+ * kunit_resource for more information.
+ */
+void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp);
+
+/**
+ * kunit_kzalloc() - Just like kunit_kmalloc(), but zeroes the allocation.
+ * @test: The test context object.
+ * @size: The size in bytes of the desired memory.
+ * @gfp: flags passed to underlying kmalloc().
+ *
+ * See kzalloc() and kunit_kmalloc() for more information.
+ */
+static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp)
+{
+	return kunit_kmalloc(test, size, gfp | __GFP_ZERO);
+}
+
+void kunit_cleanup(struct kunit *test);
+
 void __printf(3, 4) kunit_printk(const char *level,
 				 const struct kunit *test,
 				 const char *fmt, ...);
diff --git a/kunit/test.c b/kunit/test.c
index 571e4c65deb5c..f165c9d8e10b0 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -122,6 +122,8 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
 
 void kunit_init_test(struct kunit *test, const char *name)
 {
+	mutex_init(&test->lock);
+	INIT_LIST_HEAD(&test->resources);
 	test->name = name;
 	test->success = true;
 }
@@ -151,6 +153,8 @@ static void kunit_run_case(struct kunit_suite *suite,
 	if (suite->exit)
 		suite->exit(&test);
 
+	kunit_cleanup(&test);
+
 	test_case->success = test.success;
 }
 
@@ -171,6 +175,96 @@ int kunit_run_tests(struct kunit_suite *suite)
 	return 0;
 }
 
+struct kunit_resource *kunit_alloc_resource(struct kunit *test,
+					    kunit_resource_init_t init,
+					    kunit_resource_free_t free,
+					    void *context)
+{
+	struct kunit_resource *res;
+	int ret;
+
+	res = kzalloc(sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return NULL;
+
+	ret = init(res, context);
+	if (ret)
+		return NULL;
+
+	res->free = free;
+	mutex_lock(&test->lock);
+	list_add_tail(&res->node, &test->resources);
+	mutex_unlock(&test->lock);
+
+	return res;
+}
+
+void kunit_free_resource(struct kunit *test, struct kunit_resource *res)
+{
+	res->free(res);
+	list_del(&res->node);
+	kfree(res);
+}
+
+struct kunit_kmalloc_params {
+	size_t size;
+	gfp_t gfp;
+};
+
+static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_kmalloc_params *params = context;
+
+	res->allocation = kmalloc(params->size, params->gfp);
+	if (!res->allocation)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void kunit_kmalloc_free(struct kunit_resource *res)
+{
+	kfree(res->allocation);
+}
+
+void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
+{
+	struct kunit_kmalloc_params params;
+	struct kunit_resource *res;
+
+	params.size = size;
+	params.gfp = gfp;
+
+	res = kunit_alloc_resource(test,
+				   kunit_kmalloc_init,
+				   kunit_kmalloc_free,
+				   &params);
+
+	if (res)
+		return res->allocation;
+
+	return NULL;
+}
+
+void kunit_cleanup(struct kunit *test)
+{
+	struct kunit_resource *resource, *resource_safe;
+
+	mutex_lock(&test->lock);
+	/*
+	 * test->resources is a stack - each allocation must be freed in the
+	 * reverse order from which it was added since one resource may depend
+	 * on another for its entire lifetime.
+	 */
+	list_for_each_entry_safe_reverse(resource,
+					 resource_safe,
+					 &test->resources,
+					 node) {
+		kunit_free_resource(test, resource);
+	}
+	mutex_unlock(&test->lock);
+}
+
 void kunit_printk(const char *level,
 		  const struct kunit *test,
 		  const char *fmt, ...)
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 01/18] kunit: test: add KUnit test runner core Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 02/18] kunit: test: add test resource management API Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-15 20:43   ` Stephen Boyd
  2019-07-12  8:17 ` [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger Brendan Higgins
                   ` (14 subsequent siblings)
  17 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

A number of test features need to do pretty complicated string printing
where it may not be possible to rely on a single preallocated string
with parameters.

So provide a library for constructing the string as you go similar to
C++'s std::string.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 include/kunit/string-stream.h |  49 ++++++++++++
 kunit/Makefile                |   3 +-
 kunit/string-stream.c         | 147 ++++++++++++++++++++++++++++++++++
 3 files changed, 198 insertions(+), 1 deletion(-)
 create mode 100644 include/kunit/string-stream.h
 create mode 100644 kunit/string-stream.c

diff --git a/include/kunit/string-stream.h b/include/kunit/string-stream.h
new file mode 100644
index 0000000000000..0552a05781afe
--- /dev/null
+++ b/include/kunit/string-stream.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * C++ stream style string builder used in KUnit for building messages.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_STRING_STREAM_H
+#define _KUNIT_STRING_STREAM_H
+
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/kref.h>
+#include <stdarg.h>
+
+struct string_stream_fragment {
+	struct list_head node;
+	char *fragment;
+};
+
+struct string_stream {
+	size_t length;
+	struct list_head fragments;
+	/* length and fragments are protected by this lock */
+	spinlock_t lock;
+};
+
+struct kunit;
+
+struct string_stream *alloc_string_stream(struct kunit *test);
+
+void string_stream_get(struct string_stream *stream);
+
+int string_stream_put(struct string_stream *stream);
+
+int string_stream_add(struct string_stream *stream, const char *fmt, ...);
+
+int string_stream_vadd(struct string_stream *stream,
+		       const char *fmt,
+		       va_list args);
+
+char *string_stream_get_string(struct string_stream *stream);
+
+void string_stream_clear(struct string_stream *stream);
+
+bool string_stream_is_empty(struct string_stream *stream);
+
+#endif /* _KUNIT_STRING_STREAM_H */
diff --git a/kunit/Makefile b/kunit/Makefile
index 5efdc4dea2c08..275b565a0e81f 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -1 +1,2 @@
-obj-$(CONFIG_KUNIT) +=			test.o
+obj-$(CONFIG_KUNIT) +=			test.o \
+					string-stream.o
diff --git a/kunit/string-stream.c b/kunit/string-stream.c
new file mode 100644
index 0000000000000..0463a92dad74b
--- /dev/null
+++ b/kunit/string-stream.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * C++ stream style string builder used in KUnit for building messages.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <kunit/string-stream.h>
+#include <kunit/test.h>
+
+int string_stream_vadd(struct string_stream *stream,
+		       const char *fmt,
+		       va_list args)
+{
+	struct string_stream_fragment *frag_container;
+	int len;
+	va_list args_for_counting;
+	unsigned long flags;
+
+	/* Make a copy because `vsnprintf` could change it */
+	va_copy(args_for_counting, args);
+
+	/* Need space for null byte. */
+	len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
+
+	va_end(args_for_counting);
+
+	frag_container = kmalloc(sizeof(*frag_container), GFP_KERNEL);
+	if (!frag_container)
+		return -ENOMEM;
+
+	frag_container->fragment = kmalloc(len, GFP_KERNEL);
+	if (!frag_container->fragment) {
+		kfree(frag_container);
+		return -ENOMEM;
+	}
+
+	len = vsnprintf(frag_container->fragment, len, fmt, args);
+	spin_lock_irqsave(&stream->lock, flags);
+	stream->length += len;
+	list_add_tail(&frag_container->node, &stream->fragments);
+	spin_unlock_irqrestore(&stream->lock, flags);
+
+	return 0;
+}
+
+int string_stream_add(struct string_stream *stream, const char *fmt, ...)
+{
+	va_list args;
+	int result;
+
+	va_start(args, fmt);
+	result = string_stream_vadd(stream, fmt, args);
+	va_end(args);
+
+	return result;
+}
+
+void string_stream_clear(struct string_stream *stream)
+{
+	struct string_stream_fragment *frag_container, *frag_container_safe;
+	unsigned long flags;
+
+	spin_lock_irqsave(&stream->lock, flags);
+	list_for_each_entry_safe(frag_container,
+				 frag_container_safe,
+				 &stream->fragments,
+				 node) {
+		list_del(&frag_container->node);
+		kfree(frag_container->fragment);
+		kfree(frag_container);
+	}
+	stream->length = 0;
+	spin_unlock_irqrestore(&stream->lock, flags);
+}
+
+char *string_stream_get_string(struct string_stream *stream)
+{
+	struct string_stream_fragment *frag_container;
+	size_t buf_len = stream->length + 1; /* +1 for null byte. */
+	char *buf;
+	unsigned long flags;
+
+	buf = kzalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	spin_lock_irqsave(&stream->lock, flags);
+	list_for_each_entry(frag_container, &stream->fragments, node)
+		strlcat(buf, frag_container->fragment, buf_len);
+	spin_unlock_irqrestore(&stream->lock, flags);
+
+	return buf;
+}
+
+bool string_stream_is_empty(struct string_stream *stream)
+{
+	bool is_empty;
+	unsigned long flags;
+
+	spin_lock_irqsave(&stream->lock, flags);
+	is_empty = list_empty(&stream->fragments);
+	spin_unlock_irqrestore(&stream->lock, flags);
+
+	return is_empty;
+}
+
+static int string_stream_init(struct kunit_resource *res, void *context)
+{
+	struct string_stream *stream;
+
+	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+	if (!stream)
+		return -ENOMEM;
+
+	res->allocation = stream;
+	INIT_LIST_HEAD(&stream->fragments);
+	spin_lock_init(&stream->lock);
+
+	return 0;
+}
+
+static void string_stream_free(struct kunit_resource *res)
+{
+	struct string_stream *stream = res->allocation;
+
+	string_stream_clear(stream);
+	kfree(stream);
+}
+
+struct string_stream *alloc_string_stream(struct kunit *test)
+{
+	struct kunit_resource *res;
+
+	res = kunit_alloc_resource(test,
+				   string_stream_init,
+				   string_stream_free,
+				   NULL);
+
+	if (!res)
+		return NULL;
+
+	return res->allocation;
+}
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (2 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-15 22:15   ` Stephen Boyd
  2019-07-12  8:17 ` [PATCH v9 05/18] kunit: test: add the concept of expectations Brendan Higgins
                   ` (13 subsequent siblings)
  17 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

A lot of the expectation and assertion infrastructure prints out fairly
complicated test failure messages, so add a C++ style log library for
for logging test results.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 include/kunit/kunit-stream.h |  81 +++++++++++++++++++++++
 include/kunit/test.h         |   3 +
 kunit/Makefile               |   3 +-
 kunit/kunit-stream.c         | 123 +++++++++++++++++++++++++++++++++++
 kunit/test.c                 |   6 ++
 5 files changed, 215 insertions(+), 1 deletion(-)
 create mode 100644 include/kunit/kunit-stream.h
 create mode 100644 kunit/kunit-stream.c

diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
new file mode 100644
index 0000000000000..a7b53eabf6be4
--- /dev/null
+++ b/include/kunit/kunit-stream.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * C++ stream style string formatter and printer used in KUnit for outputting
+ * KUnit messages.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_KUNIT_STREAM_H
+#define _KUNIT_KUNIT_STREAM_H
+
+#include <linux/types.h>
+#include <kunit/string-stream.h>
+
+struct kunit;
+
+/**
+ * struct kunit_stream - a std::stream style string builder.
+ *
+ * A std::stream style string builder. Allows messages to be built up and
+ * printed all at once.
+ */
+struct kunit_stream {
+	/* private: internal use only. */
+	struct kunit *test;
+	const char *level;
+	struct string_stream *internal_stream;
+};
+
+/**
+ * alloc_kunit_stream() - constructs a new &struct kunit_stream.
+ * @test: The test context object.
+ * @level: The log level at which to print out the message.
+ *
+ * Constructs a new test managed &struct kunit_stream.
+ */
+struct kunit_stream *alloc_kunit_stream(struct kunit *test, const char *level);
+
+/**
+ * kunit_stream_add(): adds the formatted input to the internal buffer.
+ * @kstream: the stream being operated on.
+ * @fmt: printf style format string to append to stream.
+ *
+ * Appends the formatted string, @fmt, to the internal buffer.
+ */
+void __printf(2, 3) kunit_stream_add(struct kunit_stream *kstream,
+				     const char *fmt, ...);
+
+/**
+ * kunit_stream_append(): appends the contents of @other to @kstream.
+ * @kstream: the stream to which @other is appended.
+ * @other: the stream whose contents are appended to @kstream.
+ *
+ * Appends the contents of @other to @kstream.
+ */
+void kunit_stream_append(struct kunit_stream *kstream,
+			 struct kunit_stream *other);
+
+/**
+ * kunit_stream_commit(): prints out the internal buffer to the user.
+ * @kstream: the stream being operated on.
+ *
+ * Outputs the contents of the internal buffer as a kunit_printk formatted
+ * output. KUNIT_STREAM ONLY OUTPUTS ITS BUFFER TO THE USER IF COMMIT IS
+ * CALLED!!! The reason for this is that it allows us to construct a message
+ * before we know whether we want to print it out; this can be extremely handy
+ * if there is information you might need for a failure message that is easiest
+ * to collect in the steps leading up to the actual check.
+ */
+void kunit_stream_commit(struct kunit_stream *kstream);
+
+/**
+ * kunit_stream_clear(): clears the internal buffer.
+ * @kstream: the stream being operated on.
+ *
+ * Clears the contents of the internal buffer.
+ */
+void kunit_stream_clear(struct kunit_stream *kstream);
+
+#endif /* _KUNIT_KUNIT_STREAM_H */
diff --git a/include/kunit/test.h b/include/kunit/test.h
index bdf41d31c343c..bc7dbdcf8abab 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -11,6 +11,7 @@
 
 #include <linux/types.h>
 #include <linux/slab.h>
+#include <kunit/kunit-stream.h>
 
 struct kunit_resource;
 
@@ -184,6 +185,8 @@ struct kunit {
 
 void kunit_init_test(struct kunit *test, const char *name);
 
+void kunit_fail(struct kunit *test, struct kunit_stream *stream);
+
 int kunit_run_tests(struct kunit_suite *suite);
 
 /**
diff --git a/kunit/Makefile b/kunit/Makefile
index 275b565a0e81f..6ddc622ee6b1c 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -1,2 +1,3 @@
 obj-$(CONFIG_KUNIT) +=			test.o \
-					string-stream.o
+					string-stream.o \
+					kunit-stream.o
diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
new file mode 100644
index 0000000000000..8bea1f22eafb5
--- /dev/null
+++ b/kunit/kunit-stream.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * C++ stream style string formatter and printer used in KUnit for outputting
+ * KUnit messages.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/test.h>
+#include <kunit/kunit-stream.h>
+#include <kunit/string-stream.h>
+
+void kunit_stream_add(struct kunit_stream *kstream, const char *fmt, ...)
+{
+	va_list args;
+	struct string_stream *stream = kstream->internal_stream;
+
+	va_start(args, fmt);
+
+	if (string_stream_vadd(stream, fmt, args) < 0)
+		kunit_err(kstream->test,
+			  "Failed to allocate fragment: %s\n",
+			  fmt);
+
+	va_end(args);
+}
+
+void kunit_stream_append(struct kunit_stream *kstream,
+				struct kunit_stream *other)
+{
+	struct string_stream *other_stream = other->internal_stream;
+	const char *other_content;
+
+	other_content = string_stream_get_string(other_stream);
+
+	if (!other_content) {
+		kunit_err(kstream->test,
+			  "Failed to get string from second argument for appending\n");
+		return;
+	}
+
+	kunit_stream_add(kstream, other_content);
+}
+
+void kunit_stream_clear(struct kunit_stream *kstream)
+{
+	string_stream_clear(kstream->internal_stream);
+}
+
+void kunit_stream_commit(struct kunit_stream *kstream)
+{
+	struct string_stream *stream = kstream->internal_stream;
+	struct string_stream_fragment *fragment;
+	struct kunit *test = kstream->test;
+	char *buf;
+
+	buf = string_stream_get_string(stream);
+	if (!buf) {
+		kunit_err(test,
+			  "Could not allocate buffer, dumping stream:\n");
+		list_for_each_entry(fragment, &stream->fragments, node) {
+			kunit_err(test, fragment->fragment);
+		}
+		kunit_err(test, "\n");
+		goto cleanup;
+	}
+
+	kunit_printk(kstream->level, test, buf);
+	kfree(buf);
+
+cleanup:
+	kunit_stream_clear(kstream);
+}
+
+static int kunit_stream_init(struct kunit_resource *res, void *context)
+{
+	struct kunit *test = context;
+	struct kunit_stream *stream;
+
+	stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+	if (!stream)
+		return -ENOMEM;
+
+	res->allocation = stream;
+	stream->test = test;
+	stream->internal_stream = alloc_string_stream(test);
+
+	if (!stream->internal_stream)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void kunit_stream_free(struct kunit_resource *res)
+{
+	struct kunit_stream *stream = res->allocation;
+
+	if (!string_stream_is_empty(stream->internal_stream)) {
+		kunit_err(stream->test,
+			  "End of test case reached with uncommitted stream entries\n");
+		kunit_stream_commit(stream);
+	}
+}
+
+struct kunit_stream *alloc_kunit_stream(struct kunit *test, const char *level)
+{
+	struct kunit_stream *kstream;
+	struct kunit_resource *res;
+
+	res = kunit_alloc_resource(test,
+				   kunit_stream_init,
+				   kunit_stream_free,
+				   test);
+
+	if (!res)
+		return NULL;
+
+	kstream = res->allocation;
+	kstream->level = level;
+
+	return kstream;
+}
diff --git a/kunit/test.c b/kunit/test.c
index f165c9d8e10b0..29edf34a89a37 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -120,6 +120,12 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
 			      test_case->name);
 }
 
+void kunit_fail(struct kunit *test, struct kunit_stream *stream)
+{
+	kunit_set_failure(test);
+	kunit_stream_commit(stream);
+}
+
 void kunit_init_test(struct kunit *test, const char *name)
 {
 	mutex_init(&test->lock);
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 05/18] kunit: test: add the concept of expectations
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (3 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 06/18] kbuild: enable building KUnit Brendan Higgins
                   ` (12 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add support for expectations, which allow properties to be specified and
then verified in tests.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 include/kunit/test.h | 525 +++++++++++++++++++++++++++++++++++++++++++
 kunit/test.c         |  66 ++++++
 2 files changed, 591 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index bc7dbdcf8abab..df18765e6ea25 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -9,6 +9,7 @@
 #ifndef _KUNIT_TEST_H
 #define _KUNIT_TEST_H
 
+#include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <kunit/kunit-stream.h>
@@ -295,4 +296,528 @@ void __printf(3, 4) kunit_printk(const char *level,
 #define kunit_err(test, fmt, ...) \
 		kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)
 
+/*
+ * Generates a compile-time warning in case of comparing incompatible types.
+ */
+#define __kunit_typecheck(lhs, rhs) \
+	((void) __typecheck(lhs, rhs))
+
+static inline struct kunit_stream *kunit_expect_start(struct kunit *test,
+						      const char *file,
+						      const char *line)
+{
+	struct kunit_stream *stream = alloc_kunit_stream(test, KERN_ERR);
+
+	kunit_stream_add(stream, "EXPECTATION FAILED at %s:%s\n\t", file, line);
+
+	return stream;
+}
+
+static inline void kunit_expect_end(struct kunit *test,
+				    bool success,
+				    struct kunit_stream *stream)
+{
+	if (!success)
+		kunit_fail(test, stream);
+	else
+		kunit_stream_clear(stream);
+}
+
+#define KUNIT_EXPECT_START(test) \
+		kunit_expect_start(test, __FILE__, __stringify(__LINE__))
+
+#define KUNIT_EXPECT_END(test, success, stream) \
+		kunit_expect_end(test, success, stream)
+
+#define KUNIT_EXPECT_MSG(test, success, message, fmt, ...) do {		       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+									       \
+	kunit_stream_add(__stream, message);				       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+	KUNIT_EXPECT_END(test, success, __stream);			       \
+} while (0)
+
+#define KUNIT_EXPECT(test, success, message) do {			       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+									       \
+	kunit_stream_add(__stream, message);				       \
+	KUNIT_EXPECT_END(test, success, __stream);			       \
+} while (0)
+
+/**
+ * KUNIT_SUCCEED() - A no-op expectation. Only exists for code clarity.
+ * @test: The test context object.
+ *
+ * The opposite of KUNIT_FAIL(), it is an expectation that cannot fail. In other
+ * words, it does nothing and only exists for code clarity. See
+ * KUNIT_EXPECT_TRUE() for more information.
+ */
+#define KUNIT_SUCCEED(test) do {} while (0)
+
+/**
+ * KUNIT_FAIL() - Always causes a test to fail when evaluated.
+ * @test: The test context object.
+ * @fmt: an informational message to be printed when the assertion is made.
+ * @...: string format arguments.
+ *
+ * The opposite of KUNIT_SUCCEED(), it is an expectation that always fails. In
+ * other words, it always results in a failed expectation, and consequently
+ * always causes the test case to fail when evaluated. See KUNIT_EXPECT_TRUE()
+ * for more information.
+ */
+#define KUNIT_FAIL(test, fmt, ...) do {					       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+									       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+	KUNIT_EXPECT_END(test, false, __stream);			       \
+} while (0)
+
+/**
+ * KUNIT_EXPECT_TRUE() - Causes a test failure when the expression is not true.
+ * @test: The test context object.
+ * @condition: an arbitrary boolean expression. The test fails when this does
+ * not evaluate to true.
+ *
+ * This and expectations of the form `KUNIT_EXPECT_*` will cause the test case
+ * to fail when the specified condition is not met; however, it will not prevent
+ * the test case from continuing to run; this is otherwise known as an
+ * *expectation failure*.
+ */
+#define KUNIT_EXPECT_TRUE(test, condition)				       \
+		KUNIT_EXPECT(test, (condition),				       \
+		       "Expected " #condition " is true, but is false\n")
+
+#define KUNIT_EXPECT_TRUE_MSG(test, condition, fmt, ...)		       \
+		KUNIT_EXPECT_MSG(test, (condition),			       \
+				"Expected " #condition " is true, but is false\n",\
+				fmt, ##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_FALSE() - Makes a test failure when the expression is not false.
+ * @test: The test context object.
+ * @condition: an arbitrary boolean expression. The test fails when this does
+ * not evaluate to false.
+ *
+ * Sets an expectation that @condition evaluates to false. See
+ * KUNIT_EXPECT_TRUE() for more information.
+ */
+#define KUNIT_EXPECT_FALSE(test, condition)				       \
+		KUNIT_EXPECT(test, !(condition),			       \
+		       "Expected " #condition " is false, but is true\n")
+
+#define KUNIT_EXPECT_FALSE_MSG(test, condition, fmt, ...)		       \
+		KUNIT_EXPECT_MSG(test, !(condition),			       \
+				"Expected " #condition " is false, but is true\n",\
+				fmt, ##__VA_ARGS__)
+
+void kunit_expect_binary_msg(struct kunit *test,
+			     long long left, const char *left_name,
+			     long long right, const char *right_name,
+			     bool compare_result,
+			     const char *compare_name,
+			     const char *file,
+			     const char *line,
+			     const char *fmt, ...);
+
+static inline void kunit_expect_binary(struct kunit *test,
+				       long long left, const char *left_name,
+				       long long right, const char *right_name,
+				       bool compare_result,
+				       const char *compare_name,
+				       const char *file,
+				       const char *line)
+{
+	kunit_expect_binary_msg(test,
+				left, left_name,
+				right, right_name,
+				compare_result,
+				compare_name,
+				file,
+				line,
+				NULL);
+}
+
+void kunit_expect_ptr_binary_msg(struct kunit *test,
+				 void *left, const char *left_name,
+				 void *right, const char *right_name,
+				 bool compare_result,
+				 const char *compare_name,
+				 const char *file,
+				 const char *line,
+				 const char *fmt, ...);
+
+static inline void kunit_expect_ptr_binary(struct kunit *test,
+					   void *left, const char *left_name,
+					   void *right, const char *right_name,
+					   bool compare_result,
+					   const char *compare_name,
+					   const char *file,
+					   const char *line)
+{
+	kunit_expect_ptr_binary_msg(test,
+				    left, left_name,
+				    right, right_name,
+				    compare_result,
+				    compare_name,
+				    file,
+				    line,
+				    NULL);
+}
+
+/*
+ * A factory macro for defining the expectations for the basic comparisons
+ * defined for the built in types.
+ *
+ * Unfortunately, there is no common type that all types can be promoted to for
+ * which all the binary operators behave the same way as for the actual types
+ * (for example, there is no type that long long and unsigned long long can
+ * both be cast to where the comparison result is preserved for all values). So
+ * the best we can do is do the comparison in the original types and then coerce
+ * everything to long long for printing; this way, the comparison behaves
+ * correctly and the printed out value usually makes sense without
+ * interpretation, but can always be interpretted to figure out the actual
+ * value.
+ */
+#define KUNIT_EXPECT_BINARY(test, left, condition, right) do {		       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_expect_binary(test,					       \
+			    (long long) __left, #left,			       \
+			    (long long) __right, #right,		       \
+			    __left condition __right, #condition,	       \
+			    __FILE__, __stringify(__LINE__));		       \
+} while (0)
+
+#define KUNIT_EXPECT_BINARY_MSG(test, left, condition, right, fmt, ...) do {   \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_expect_binary_msg(test,					       \
+				(long long) __left, #left,		       \
+				(long long) __right, #right,		       \
+				__left condition __right, #condition,	       \
+				__FILE__, __stringify(__LINE__),	       \
+				fmt, ##__VA_ARGS__);			       \
+} while (0)
+
+/*
+ * Just like KUNIT_EXPECT_BINARY, but for comparing pointer types.
+ */
+#define KUNIT_EXPECT_PTR_BINARY(test, left, condition, right) do {	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_expect_ptr_binary(test,					       \
+			    (void *) __left, #left,			       \
+			    (void *) __right, #right,			       \
+			    __left condition __right, #condition,	       \
+			    __FILE__, __stringify(__LINE__));		       \
+} while (0)
+
+#define KUNIT_EXPECT_PTR_BINARY_MSG(test, left, condition, right, fmt, ...)    \
+do {									       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_expect_ptr_binary_msg(test,				       \
+				    (void *) __left, #left,		       \
+				    (void *) __right, #right,		       \
+				    __left condition __right, #condition,      \
+				    __FILE__, __stringify(__LINE__),	       \
+				    fmt, ##__VA_ARGS__);		       \
+} while (0)
+
+/**
+ * KUNIT_EXPECT_EQ() - Sets an expectation that @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) == (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_EQ(test, left, right) \
+		KUNIT_EXPECT_BINARY(test, left, ==, right)
+
+#define KUNIT_EXPECT_EQ_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_BINARY_MSG(test,				       \
+					left,				       \
+					==,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_PTR_EQ() - Expects that pointers @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a pointer.
+ * @right: an arbitrary expression that evaluates to a pointer.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) == (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_PTR_EQ(test, left, right) \
+		KUNIT_EXPECT_PTR_BINARY(test, left, ==, right)
+
+#define KUNIT_EXPECT_PTR_EQ_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_PTR_BINARY_MSG(test,			       \
+					    left,			       \
+					    ==,				       \
+					    right,			       \
+					    fmt,			       \
+					    ##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_NE() - An expectation that @left and @right are not equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are not
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) != (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_NE(test, left, right) \
+		KUNIT_EXPECT_BINARY(test, left, !=, right)
+
+#define KUNIT_EXPECT_NE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_BINARY_MSG(test,				       \
+					left,				       \
+					!=,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_PTR_NE() - Expects that pointers @left and @right are not equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a pointer.
+ * @right: an arbitrary expression that evaluates to a pointer.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are not
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) != (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_PTR_NE(test, left, right) \
+		KUNIT_EXPECT_PTR_BINARY(test, left, !=, right)
+
+#define KUNIT_EXPECT_PTR_NE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_PTR_BINARY_MSG(test,			       \
+					    left,			       \
+					    !=,				       \
+					    right,			       \
+					    fmt,			       \
+					    ##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_LT() - An expectation that @left is less than @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is less than the
+ * value that @right evaluates to. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) < (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_LT(test, left, right) \
+		KUNIT_EXPECT_BINARY(test, left, <, right)
+
+#define KUNIT_EXPECT_LT_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_BINARY_MSG(test,				       \
+					left,				       \
+					<,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_LE() - Expects that @left is less than or equal to @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is less than or
+ * equal to the value that @right evaluates to. Semantically this is equivalent
+ * to KUNIT_EXPECT_TRUE(@test, (@left) <= (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_LE(test, left, right) \
+		KUNIT_EXPECT_BINARY(test, left, <=, right)
+
+#define KUNIT_EXPECT_LE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_BINARY_MSG(test,				       \
+					left,				       \
+					<=,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_GT() - An expectation that @left is greater than @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is greater than
+ * the value that @right evaluates to. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) > (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_GT(test, left, right) \
+		KUNIT_EXPECT_BINARY(test, left, >, right)
+
+#define KUNIT_EXPECT_GT_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_BINARY_MSG(test,				       \
+					left,				       \
+					>,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_GE() - Expects that @left is greater than or equal to @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an expectation that the value that @left evaluates to is greater than
+ * the value that @right evaluates to. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, (@left) >= (@right)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_GE(test, left, right) \
+		KUNIT_EXPECT_BINARY(test, left, >=, right)
+
+#define KUNIT_EXPECT_GE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_EXPECT_BINARY_MSG(test,				       \
+					left,				       \
+					>=,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_EXPECT_STREQ() - Expects that strings @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a null terminated string.
+ * @right: an arbitrary expression that evaluates to a null terminated string.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, !strcmp((@left), (@right))). See KUNIT_EXPECT_TRUE()
+ * for more information.
+ */
+#define KUNIT_EXPECT_STREQ(test, left, right) do {			       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Expected " #left " == " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+									       \
+	KUNIT_EXPECT_END(test, !strcmp(left, right), __stream);		       \
+} while (0)
+
+#define KUNIT_EXPECT_STREQ_MSG(test, left, right, fmt, ...) do {	       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Expected " #left " == " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+									       \
+	KUNIT_EXPECT_END(test, !strcmp(left, right), __stream);		       \
+} while (0)
+
+/**
+ * KUNIT_EXPECT_STRNEQ() - Expects that strings @left and @right are not equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a null terminated string.
+ * @right: an arbitrary expression that evaluates to a null terminated string.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * not equal. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, strcmp((@left), (@right))). See KUNIT_EXPECT_TRUE()
+ * for more information.
+ */
+#define KUNIT_EXPECT_STRNEQ(test, left, right) do {			       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Expected " #left " != " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+									       \
+	KUNIT_EXPECT_END(test, strcmp(left, right), __stream);		       \
+} while (0)
+
+#define KUNIT_EXPECT_STRNEQ_MSG(test, left, right, fmt, ...) do {	       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Expected " #left " != " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+									       \
+	KUNIT_EXPECT_END(test, strcmp(left, right), __stream);		       \
+} while (0)
+
+/**
+ * KUNIT_EXPECT_NOT_ERR_OR_NULL() - Expects that @ptr is not null and not err.
+ * @test: The test context object.
+ * @ptr: an arbitrary pointer.
+ *
+ * Sets an expectation that the value that @ptr evaluates to is not null and not
+ * an errno stored in a pointer. This is semantically equivalent to
+ * KUNIT_EXPECT_TRUE(@test, !IS_ERR_OR_NULL(@ptr)). See KUNIT_EXPECT_TRUE() for
+ * more information.
+ */
+#define KUNIT_EXPECT_NOT_ERR_OR_NULL(test, ptr) do {			       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+	typeof(ptr) __ptr = (ptr);					       \
+									       \
+	if (!__ptr)							       \
+		kunit_stream_add(__stream,				       \
+			      "Expected " #ptr " is not null, but is\n");      \
+	if (IS_ERR(__ptr))						       \
+		kunit_stream_add(__stream,				       \
+			      "Expected " #ptr " is not error, but is: %ld",   \
+			      PTR_ERR(__ptr));				       \
+									       \
+	KUNIT_EXPECT_END(test, !IS_ERR_OR_NULL(__ptr), __stream);	       \
+} while (0)
+
+#define KUNIT_EXPECT_NOT_ERR_OR_NULL_MSG(test, ptr, fmt, ...) do {	       \
+	struct kunit_stream *__stream = KUNIT_EXPECT_START(test);	       \
+	typeof(ptr) __ptr = (ptr);					       \
+									       \
+	if (!__ptr) {							       \
+		kunit_stream_add(__stream,				       \
+			      "Expected " #ptr " is not null, but is\n");      \
+		kunit_stream_add(__stream, fmt, ##__VA_ARGS__);		       \
+	}								       \
+	if (IS_ERR(__ptr)) {						       \
+		kunit_stream_add(__stream,				       \
+			      "Expected " #ptr " is not error, but is: %ld",   \
+			      PTR_ERR(__ptr));				       \
+									       \
+		kunit_stream_add(__stream, fmt, ##__VA_ARGS__);		       \
+	}								       \
+	KUNIT_EXPECT_END(test, !IS_ERR_OR_NULL(__ptr), __stream);	       \
+} while (0)
+
 #endif /* _KUNIT_TEST_H */
diff --git a/kunit/test.c b/kunit/test.c
index 29edf34a89a37..8c745fd0c82d3 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -287,3 +287,69 @@ void kunit_printk(const char *level,
 
 	va_end(args);
 }
+
+void kunit_expect_binary_msg(struct kunit *test,
+			     long long left, const char *left_name,
+			     long long right, const char *right_name,
+			     bool compare_result,
+			     const char *compare_name,
+			     const char *file,
+			     const char *line,
+			     const char *fmt, ...)
+{
+	struct kunit_stream *stream = kunit_expect_start(test, file, line);
+	struct va_format vaf;
+	va_list args;
+
+	kunit_stream_add(stream,
+			 "Expected %s %s %s, but\n",
+			 left_name, compare_name, right_name);
+	kunit_stream_add(stream, "\t\t%s == %lld\n", left_name, left);
+	kunit_stream_add(stream, "\t\t%s == %lld", right_name, right);
+
+	if (fmt) {
+		va_start(args, fmt);
+
+		vaf.fmt = fmt;
+		vaf.va = &args;
+
+		kunit_stream_add(stream, "\n%pV", &vaf);
+
+		va_end(args);
+	}
+
+	kunit_expect_end(test, compare_result, stream);
+}
+
+void kunit_expect_ptr_binary_msg(struct kunit *test,
+				 void *left, const char *left_name,
+				 void *right, const char *right_name,
+				 bool compare_result,
+				 const char *compare_name,
+				 const char *file,
+				 const char *line,
+				 const char *fmt, ...)
+{
+	struct kunit_stream *stream = kunit_expect_start(test, file, line);
+	struct va_format vaf;
+	va_list args;
+
+	kunit_stream_add(stream,
+			 "Expected %s %s %s, but\n",
+			 left_name, compare_name, right_name);
+	kunit_stream_add(stream, "\t\t%s == %pK\n", left_name, left);
+	kunit_stream_add(stream, "\t\t%s == %pK", right_name, right);
+
+	if (fmt) {
+		va_start(args, fmt);
+
+		vaf.fmt = fmt;
+		vaf.va = &args;
+
+		kunit_stream_add(stream, "\n%pV", &vaf);
+
+		va_end(args);
+	}
+
+	kunit_expect_end(test, compare_result, stream);
+}
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 06/18] kbuild: enable building KUnit
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (4 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 05/18] kunit: test: add the concept of expectations Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-15 20:49   ` Stephen Boyd
  2019-07-12  8:17 ` [PATCH v9 07/18] kunit: test: add initial tests Brendan Higgins
                   ` (11 subsequent siblings)
  17 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins, Michal Marek

KUnit is a new unit testing framework for the kernel and when used is
built into the kernel as a part of it. Add KUnit to the root Kconfig and
Makefile to allow it to be actually built.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 Kconfig  | 2 ++
 Makefile | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/Kconfig b/Kconfig
index 48a80beab6853..10428501edb78 100644
--- a/Kconfig
+++ b/Kconfig
@@ -30,3 +30,5 @@ source "crypto/Kconfig"
 source "lib/Kconfig"
 
 source "lib/Kconfig.debug"
+
+source "kunit/Kconfig"
diff --git a/Makefile b/Makefile
index 3e4868a6498b2..0ce1a8a2b6fec 100644
--- a/Makefile
+++ b/Makefile
@@ -993,6 +993,8 @@ PHONY += prepare0
 ifeq ($(KBUILD_EXTMOD),)
 core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
 
+core-$(CONFIG_KUNIT) += kunit/
+
 vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
 		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
 		     $(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 07/18] kunit: test: add initial tests
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (5 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 06/18] kbuild: enable building KUnit Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 08/18] objtool: add kunit_try_catch_throw to the noreturn list Brendan Higgins
                   ` (10 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add a test for string stream along with a simpler example.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 kunit/Kconfig              | 21 +++++++++
 kunit/Makefile             |  4 ++
 kunit/example-test.c       | 88 ++++++++++++++++++++++++++++++++++++++
 kunit/string-stream-test.c | 75 ++++++++++++++++++++++++++++++++
 4 files changed, 188 insertions(+)
 create mode 100644 kunit/example-test.c
 create mode 100644 kunit/string-stream-test.c

diff --git a/kunit/Kconfig b/kunit/Kconfig
index 330ae83527c23..8541ef95b65ad 100644
--- a/kunit/Kconfig
+++ b/kunit/Kconfig
@@ -14,4 +14,25 @@ config KUNIT
 	  architectures. For more information, please see
 	  Documentation/dev-tools/kunit/.
 
+config KUNIT_TEST
+	bool "KUnit test for KUnit"
+	depends on KUNIT
+	help
+	  Enables the unit tests for the KUnit test framework. These tests test
+	  the KUnit test framework itself; the tests are both written using
+	  KUnit and test KUnit. This option should only be enabled for testing
+	  purposes by developers interested in testing that KUnit works as
+	  expected.
+
+config KUNIT_EXAMPLE_TEST
+	bool "Example test for KUnit"
+	depends on KUNIT
+	help
+	  Enables an example unit test that illustrates some of the basic
+	  features of KUnit. This test only exists to help new users understand
+	  what KUnit is and how it is used. Please refer to the example test
+	  itself, kunit/example-test.c, for more information. This option is
+	  intended for curious hackers who would like to understand how to use
+	  KUnit for kernel development.
+
 endmenu
diff --git a/kunit/Makefile b/kunit/Makefile
index 6ddc622ee6b1c..60a9ea6cb4697 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -1,3 +1,7 @@
 obj-$(CONFIG_KUNIT) +=			test.o \
 					string-stream.o \
 					kunit-stream.o
+
+obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
+
+obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	example-test.o
diff --git a/kunit/example-test.c b/kunit/example-test.c
new file mode 100644
index 0000000000000..f64a829aa441f
--- /dev/null
+++ b/kunit/example-test.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Example KUnit test to show how to use KUnit.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/test.h>
+
+/*
+ * This is the most fundamental element of KUnit, the test case. A test case
+ * makes a set EXPECTATIONs and ASSERTIONs about the behavior of some code; if
+ * any expectations or assertions are not met, the test fails; otherwise, the
+ * test passes.
+ *
+ * In KUnit, a test case is just a function with the signature
+ * `void (*)(struct kunit *)`. `struct kunit` is a context object that stores
+ * information about the current test.
+ */
+static void example_simple_test(struct kunit *test)
+{
+	/*
+	 * This is an EXPECTATION; it is how KUnit tests things. When you want
+	 * to test a piece of code, you set some expectations about what the
+	 * code should do. KUnit then runs the test and verifies that the code's
+	 * behavior matched what was expected.
+	 */
+	KUNIT_EXPECT_EQ(test, 1 + 1, 2);
+}
+
+/*
+ * This is run once before each test case, see the comment on
+ * example_test_suite for more information.
+ */
+static int example_test_init(struct kunit *test)
+{
+	kunit_info(test, "initializing\n");
+
+	return 0;
+}
+
+/*
+ * Here we make a list of all the test cases we want to add to the test suite
+ * below.
+ */
+static struct kunit_case example_test_cases[] = {
+	/*
+	 * This is a helper to create a test case object from a test case
+	 * function; its exact function is not important to understand how to
+	 * use KUnit, just know that this is how you associate test cases with a
+	 * test suite.
+	 */
+	KUNIT_CASE(example_simple_test),
+	{}
+};
+
+/*
+ * This defines a suite or grouping of tests.
+ *
+ * Test cases are defined as belonging to the suite by adding them to
+ * `kunit_cases`.
+ *
+ * Often it is desirable to run some function which will set up things which
+ * will be used by every test; this is accomplished with an `init` function
+ * which runs before each test case is invoked. Similarly, an `exit` function
+ * may be specified which runs after every test case and can be used to for
+ * cleanup. For clarity, running tests in a test suite would behave as follows:
+ *
+ * suite.init(test);
+ * suite.test_case[0](test);
+ * suite.exit(test);
+ * suite.init(test);
+ * suite.test_case[1](test);
+ * suite.exit(test);
+ * ...;
+ */
+static struct kunit_suite example_test_suite = {
+	.name = "example",
+	.init = example_test_init,
+	.test_cases = example_test_cases,
+};
+
+/*
+ * This registers the above test suite telling KUnit that this is a suite of
+ * tests that need to be run.
+ */
+kunit_test_suite(example_test_suite);
diff --git a/kunit/string-stream-test.c b/kunit/string-stream-test.c
new file mode 100644
index 0000000000000..b5641b078b8f6
--- /dev/null
+++ b/kunit/string-stream-test.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for struct string_stream.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <linux/slab.h>
+#include <kunit/test.h>
+#include <kunit/string-stream.h>
+
+static void string_stream_test_empty_on_creation(struct kunit *test)
+{
+	struct string_stream *stream = alloc_string_stream(test);
+
+	KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
+}
+
+static void string_stream_test_not_empty_after_add(struct kunit *test)
+{
+	struct string_stream *stream = alloc_string_stream(test);
+
+	string_stream_add(stream, "Foo");
+
+	KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+}
+static void string_stream_test_get_string(struct kunit *test)
+{
+	struct string_stream *stream = alloc_string_stream(test);
+	char *output;
+
+	string_stream_add(stream, "Foo");
+	string_stream_add(stream, " %s", "bar");
+
+	output = string_stream_get_string(stream);
+	KUNIT_EXPECT_STREQ(test, output, "Foo bar");
+	kfree(output);
+}
+
+static void string_stream_test_add_and_clear(struct kunit *test)
+{
+	struct string_stream *stream = alloc_string_stream(test);
+	char *output;
+	int i;
+
+	for (i = 0; i < 10; i++)
+		string_stream_add(stream, "A");
+
+	output = string_stream_get_string(stream);
+	KUNIT_EXPECT_STREQ(test, output, "AAAAAAAAAA");
+	KUNIT_EXPECT_EQ(test, stream->length, (size_t)10);
+	KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+	kfree(output);
+
+	string_stream_clear(stream);
+
+	output = string_stream_get_string(stream);
+	KUNIT_EXPECT_STREQ(test, output, "");
+	KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
+}
+
+static struct kunit_case string_stream_test_cases[] = {
+	KUNIT_CASE(string_stream_test_empty_on_creation),
+	KUNIT_CASE(string_stream_test_not_empty_after_add),
+	KUNIT_CASE(string_stream_test_get_string),
+	KUNIT_CASE(string_stream_test_add_and_clear),
+	{}
+};
+
+static struct kunit_suite string_stream_test_suite = {
+	.name = "string-stream-test",
+	.test_cases = string_stream_test_cases
+};
+kunit_test_suite(string_stream_test_suite);
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 08/18] objtool: add kunit_try_catch_throw to the noreturn list
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (6 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 07/18] kunit: test: add initial tests Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 09/18] kunit: test: add support for test abort Brendan Higgins
                   ` (9 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins, kbuild test robot

Fix the following warning seen on GCC 7.3:
  kunit/test-test.o: warning: objtool: kunit_test_unsuccessful_try() falls through to next function kunit_test_catch()

kunit_try_catch_throw is a function added in the following patch in this
series; it allows KUnit, a unit testing framework for the kernel, to
bail out of a broken test. As a consequence, it is a new __noreturn
function that objtool thinks is broken (as seen above). So fix this
warning by adding kunit_try_catch_throw to objtool's noreturn list.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://www.spinics.net/lists/linux-kbuild/msg21708.html
Cc: Peter Zijlstra <peterz@infradead.org>
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 172f991957269..98db5fe85c797 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -134,6 +134,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"usercopy_abort",
 		"machine_real_restart",
 		"rewind_stack_do_exit",
+		"kunit_try_catch_throw",
 	};
 
 	if (func->bind == STB_WEAK)
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 09/18] kunit: test: add support for test abort
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (7 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 08/18] objtool: add kunit_try_catch_throw to the noreturn list Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 10/18] kunit: test: add tests for kunit " Brendan Higgins
                   ` (8 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add support for aborting/bailing out of test cases, which is needed for
implementing assertions.

An assertion is like an expectation, but bails out of the test case
early if the assertion is not met. The idea with assertions is that you
use them to state all the preconditions for your test. Logically
speaking, these are the premises of the test case, so if a premise isn't
true, there is no point in continuing the test case because there are no
conclusions that can be drawn without the premises. Whereas, the
expectation is the thing you are trying to prove.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 include/kunit/test.h      |  16 ++++
 include/kunit/try-catch.h |  69 +++++++++++++++
 kunit/Makefile            |   3 +-
 kunit/test.c              | 176 +++++++++++++++++++++++++++++++++++---
 kunit/try-catch.c         |  95 ++++++++++++++++++++
 5 files changed, 344 insertions(+), 15 deletions(-)
 create mode 100644 include/kunit/try-catch.h
 create mode 100644 kunit/try-catch.c

diff --git a/include/kunit/test.h b/include/kunit/test.h
index df18765e6ea25..01440f3569847 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -13,6 +13,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <kunit/kunit-stream.h>
+#include <kunit/try-catch.h>
 
 struct kunit_resource;
 
@@ -167,6 +168,7 @@ struct kunit {
 
 	/* private: internal use only. */
 	const char *name; /* Read only after initialization! */
+	struct kunit_try_catch try_catch;
 	/*
 	 * success starts as true, and may only be set to false during a test
 	 * case; thus, it is safe to update this across multiple threads using
@@ -176,6 +178,11 @@ struct kunit {
 	 */
 	bool success; /* Read only after test_case finishes! */
 	struct mutex lock; /* Gaurds all mutable test state. */
+	/*
+	 * death_test may be both set and unset from multiple threads in a test
+	 * case.
+	 */
+	bool death_test; /* Protected by lock. */
 	/*
 	 * Because resources is a list that may be updated multiple times (with
 	 * new resources) from any thread associated with a test case, we must
@@ -184,10 +191,19 @@ struct kunit {
 	struct list_head resources; /* Protected by lock. */
 };
 
+static inline void kunit_set_death_test(struct kunit *test, bool death_test)
+{
+	mutex_lock(&test->lock);
+	test->death_test = death_test;
+	mutex_unlock(&test->lock);
+}
+
 void kunit_init_test(struct kunit *test, const char *name);
 
 void kunit_fail(struct kunit *test, struct kunit_stream *stream);
 
+void kunit_abort(struct kunit *test);
+
 int kunit_run_tests(struct kunit_suite *suite);
 
 /**
diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h
new file mode 100644
index 0000000000000..8a414a9af0b64
--- /dev/null
+++ b/include/kunit/try-catch.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * An API to allow a function, that may fail, to be executed, and recover in a
+ * controlled manner.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_TRY_CATCH_H
+#define _KUNIT_TRY_CATCH_H
+
+#include <linux/types.h>
+
+typedef void (*kunit_try_catch_func_t)(void *);
+
+struct kunit;
+
+/*
+ * struct kunit_try_catch - provides a generic way to run code which might fail.
+ * @context: used to pass user data to the try and catch functions.
+ *
+ * kunit_try_catch provides a generic, architecture independent way to execute
+ * an arbitrary function of type kunit_try_catch_func_t which may bail out by
+ * calling kunit_try_catch_throw(). If kunit_try_catch_throw() is called, @try
+ * is stopped at the site of invocation and @catch is catch is called.
+ *
+ * struct kunit_try_catch provides a generic interface for the functionality
+ * needed to implement kunit->abort() which in turn is needed for implementing
+ * assertions. Assertions allow stating a precondition for a test simplifying
+ * how test cases are written and presented.
+ *
+ * Assertions are like expectations, except they abort (call
+ * kunit_try_catch_throw()) when the specified condition is not met. This is
+ * useful when you look at a test case as a logical statement about some piece
+ * of code, where assertions are the premises for the test case, and the
+ * conclusion is a set of predicates, rather expectations, that must all be
+ * true. If your premises are violated, it does not makes sense to continue.
+ */
+struct kunit_try_catch {
+	/* private: internal use only. */
+	struct kunit *test;
+	struct completion *try_completion;
+	int try_result;
+	kunit_try_catch_func_t try;
+	kunit_try_catch_func_t catch;
+	void *context;
+};
+
+void kunit_try_catch_init(struct kunit_try_catch *try_catch,
+			  struct kunit *test,
+			  kunit_try_catch_func_t try,
+			  kunit_try_catch_func_t catch);
+
+void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context);
+
+void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch);
+
+static inline int kunit_try_catch_get_result(struct kunit_try_catch *try_catch)
+{
+	return try_catch->try_result;
+}
+
+/*
+ * Exposed for testing only.
+ */
+void kunit_generic_try_catch_init(struct kunit_try_catch *try_catch);
+
+#endif /* _KUNIT_TRY_CATCH_H */
diff --git a/kunit/Makefile b/kunit/Makefile
index 60a9ea6cb4697..1f7680cfa11ad 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_KUNIT) +=			test.o \
 					string-stream.o \
-					kunit-stream.o
+					kunit-stream.o \
+					try-catch.o
 
 obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
 
diff --git a/kunit/test.c b/kunit/test.c
index 8c745fd0c82d3..731f3c9eecf20 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -7,13 +7,26 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/sched/debug.h>
 #include <kunit/test.h>
+#include <kunit/try-catch.h>
 
 static void kunit_set_failure(struct kunit *test)
 {
 	WRITE_ONCE(test->success, false);
 }
 
+static bool kunit_get_death_test(struct kunit *test)
+{
+	bool death_test;
+
+	mutex_lock(&test->lock);
+	death_test = test->death_test;
+	mutex_unlock(&test->lock);
+
+	return death_test;
+}
+
 static int kunit_vprintk_emit(int level, const char *fmt, va_list args)
 {
 	return vprintk_emit(0, level, NULL, 0, fmt, args);
@@ -126,40 +139,175 @@ void kunit_fail(struct kunit *test, struct kunit_stream *stream)
 	kunit_stream_commit(stream);
 }
 
+void __noreturn kunit_abort(struct kunit *test)
+{
+	kunit_set_death_test(test, true);
+
+	kunit_try_catch_throw(&test->try_catch);
+
+	/*
+	 * Throw could not abort from test.
+	 *
+	 * XXX: we should never reach this line! As kunit_try_catch_throw is
+	 * marked __noreturn.
+	 */
+	WARN_ONCE(true, "Throw could not abort from test!\n");
+}
+
 void kunit_init_test(struct kunit *test, const char *name)
 {
 	mutex_init(&test->lock);
 	INIT_LIST_HEAD(&test->resources);
 	test->name = name;
 	test->success = true;
+	test->death_test = false;
 }
 
 /*
- * Performs all logic to run a test case.
+ * Initializes and runs test case. Does not clean up or do post validations.
  */
-static void kunit_run_case(struct kunit_suite *suite,
-			   struct kunit_case *test_case)
+static void kunit_run_case_internal(struct kunit *test,
+				    struct kunit_suite *suite,
+				    struct kunit_case *test_case)
 {
-	struct kunit test;
-	int ret = 0;
-
-	kunit_init_test(&test, test_case->name);
+	int ret;
 
 	if (suite->init) {
-		ret = suite->init(&test);
+		ret = suite->init(test);
 		if (ret) {
-			kunit_err(&test, "failed to initialize: %d\n", ret);
-			kunit_set_failure(&test);
+			kunit_err(test, "failed to initialize: %d\n", ret);
+			kunit_set_failure(test);
 			return;
 		}
 	}
 
-	test_case->run_case(&test);
+	test_case->run_case(test);
+}
+
+static void kunit_case_internal_cleanup(struct kunit *test)
+{
+	kunit_cleanup(test);
+}
 
+/*
+ * Performs post validations and cleanup after a test case was run.
+ * XXX: Should ONLY BE CALLED AFTER kunit_run_case_internal!
+ */
+static void kunit_run_case_cleanup(struct kunit *test,
+				   struct kunit_suite *suite)
+{
 	if (suite->exit)
-		suite->exit(&test);
+		suite->exit(test);
+
+	kunit_case_internal_cleanup(test);
+}
+
+/*
+ * Handles an unexpected crash in a test case.
+ */
+static void kunit_handle_test_crash(struct kunit *test,
+				   struct kunit_suite *suite,
+				   struct kunit_case *test_case)
+{
+	kunit_err(test, "kunit test case crashed!");
+	/*
+	 * TODO(brendanhiggins@google.com): This prints the stack trace up
+	 * through this frame, not up to the frame that caused the crash.
+	 */
+	show_stack(NULL, NULL);
+
+	kunit_case_internal_cleanup(test);
+}
+
+struct kunit_try_catch_context {
+	struct kunit *test;
+	struct kunit_suite *suite;
+	struct kunit_case *test_case;
+};
+
+static void kunit_try_run_case(void *data)
+{
+	struct kunit_try_catch_context *ctx = data;
+	struct kunit *test = ctx->test;
+	struct kunit_suite *suite = ctx->suite;
+	struct kunit_case *test_case = ctx->test_case;
+
+	/*
+	 * kunit_run_case_internal may encounter a fatal error; if it does,
+	 * abort will be called, this thread will exit, and finally the parent
+	 * thread will resume control and handle any necessary clean up.
+	 */
+	kunit_run_case_internal(test, suite, test_case);
+	/* This line may never be reached. */
+	kunit_run_case_cleanup(test, suite);
+}
+
+static void kunit_catch_run_case(void *data)
+{
+	struct kunit_try_catch_context *ctx = data;
+	struct kunit *test = ctx->test;
+	struct kunit_suite *suite = ctx->suite;
+	struct kunit_case *test_case = ctx->test_case;
+	int try_exit_code = kunit_try_catch_get_result(&test->try_catch);
+
+	if (try_exit_code) {
+		kunit_set_failure(test);
+		/*
+		 * Test case could not finish, we have no idea what state it is
+		 * in, so don't do clean up.
+		 */
+		if (try_exit_code == -ETIMEDOUT)
+			kunit_err(test, "test case timed out\n");
+		/*
+		 * Unknown internal error occurred preventing test case from
+		 * running, so there is nothing to clean up.
+		 */
+		else
+			kunit_err(test, "internal error occurred preventing test case from running: %d\n",
+				  try_exit_code);
+		return;
+	}
+
+	if (kunit_get_death_test(test)) {
+		/*
+		 * EXPECTED DEATH: kunit_run_case_internal encountered
+		 * anticipated fatal error. Everything should be in a safe
+		 * state.
+		 */
+		kunit_run_case_cleanup(test, suite);
+	} else {
+		/*
+		 * UNEXPECTED DEATH: kunit_run_case_internal encountered an
+		 * unanticipated fatal error. We have no idea what the state of
+		 * the test case is in.
+		 */
+		kunit_handle_test_crash(test, suite, test_case);
+		kunit_set_failure(test);
+	}
+}
+
+/*
+ * Performs all logic to run a test case. It also catches most errors that
+ * occurs in a test case and reports them as failures.
+ */
+static void kunit_run_case_catch_errors(struct kunit_suite *suite,
+					struct kunit_case *test_case)
+{
+	struct kunit_try_catch_context context;
+	struct kunit_try_catch *try_catch;
+	struct kunit test;
+
+	kunit_init_test(&test, test_case->name);
+	try_catch = &test.try_catch;
 
-	kunit_cleanup(&test);
+	kunit_try_catch_init(try_catch,
+			     &test,
+			     kunit_try_run_case,
+			     kunit_catch_run_case);
+	context.test = &test;
+	context.suite = suite;
+	context.test_case = test_case;
+	kunit_try_catch_run(try_catch, &context);
 
 	test_case->success = test.success;
 }
@@ -172,7 +320,7 @@ int kunit_run_tests(struct kunit_suite *suite)
 	kunit_print_subtest_start(suite);
 
 	for (test_case = suite->test_cases; test_case->run_case; test_case++) {
-		kunit_run_case(suite, test_case);
+		kunit_run_case_catch_errors(suite, test_case);
 		kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
 	}
 
diff --git a/kunit/try-catch.c b/kunit/try-catch.c
new file mode 100644
index 0000000000000..de580f074387b
--- /dev/null
+++ b/kunit/try-catch.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * An API to allow a function, that may fail, to be executed, and recover in a
+ * controlled manner.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <kunit/try-catch.h>
+#include <kunit/test.h>
+#include <linux/completion.h>
+#include <linux/kthread.h>
+
+void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
+{
+	try_catch->try_result = -EFAULT;
+	complete_and_exit(try_catch->try_completion, -EFAULT);
+}
+
+static int kunit_generic_run_threadfn_adapter(void *data)
+{
+	struct kunit_try_catch *try_catch = data;
+
+	try_catch->try(try_catch->context);
+
+	complete_and_exit(try_catch->try_completion, 0);
+}
+
+void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
+{
+	DECLARE_COMPLETION_ONSTACK(try_completion);
+	struct kunit *test = try_catch->test;
+	struct task_struct *task_struct;
+	int exit_code, status;
+
+	try_catch->context = context;
+	try_catch->try_completion = &try_completion;
+	try_catch->try_result = 0;
+	task_struct = kthread_run(kunit_generic_run_threadfn_adapter,
+				  try_catch,
+				  "kunit_try_catch_thread");
+	if (IS_ERR(task_struct)) {
+		try_catch->catch(try_catch->context);
+		return;
+	}
+
+	/*
+	 * TODO(brendanhiggins@google.com): We should probably have some type of
+	 * variable timeout here. The only question is what that timeout value
+	 * should be.
+	 *
+	 * The intention has always been, at some point, to be able to label
+	 * tests with some type of size bucket (unit/small, integration/medium,
+	 * large/system/end-to-end, etc), where each size bucket would get a
+	 * default timeout value kind of like what Bazel does:
+	 * https://docs.bazel.build/versions/master/be/common-definitions.html#test.size
+	 * There is still some debate to be had on exactly how we do this. (For
+	 * one, we probably want to have some sort of test runner level
+	 * timeout.)
+	 *
+	 * For more background on this topic, see:
+	 * https://mike-bland.com/2011/11/01/small-medium-large.html
+	 */
+	status = wait_for_completion_timeout(&try_completion,
+					     300 * MSEC_PER_SEC); /* 5 min */
+	if (status < 0) {
+		kunit_err(test, "try timed out\n");
+		try_catch->try_result = -ETIMEDOUT;
+	}
+
+	exit_code = try_catch->try_result;
+
+	if (!exit_code)
+		return;
+
+	if (exit_code == -EFAULT)
+		try_catch->try_result = 0;
+	else if (exit_code == -EINTR)
+		kunit_err(test, "wake_up_process() was never called\n");
+	else if (exit_code)
+		kunit_err(test, "Unknown error: %d\n", exit_code);
+
+	try_catch->catch(try_catch->context);
+}
+
+void kunit_try_catch_init(struct kunit_try_catch *try_catch,
+			  struct kunit *test,
+			  kunit_try_catch_func_t try,
+			  kunit_try_catch_func_t catch)
+{
+	try_catch->test = test;
+	try_catch->try = try;
+	try_catch->catch = catch;
+}
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 10/18] kunit: test: add tests for kunit test abort
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (8 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 09/18] kunit: test: add support for test abort Brendan Higgins
@ 2019-07-12  8:17 ` " Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 11/18] kunit: test: add the concept of assertions Brendan Higgins
                   ` (7 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add KUnit tests for the KUnit test abort mechanism (see preceding
commit). Add tests both for general try catch mechanism as well as
non-architecture specific mechanism.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 kunit/Makefile    |   3 +-
 kunit/test-test.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+), 1 deletion(-)
 create mode 100644 kunit/test-test.c

diff --git a/kunit/Makefile b/kunit/Makefile
index 1f7680cfa11ad..533355867abd2 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -3,6 +3,7 @@ obj-$(CONFIG_KUNIT) +=			test.o \
 					kunit-stream.o \
 					try-catch.o
 
-obj-$(CONFIG_KUNIT_TEST) +=		string-stream-test.o
+obj-$(CONFIG_KUNIT_TEST) +=		test-test.o \
+					string-stream-test.o
 
 obj-$(CONFIG_KUNIT_EXAMPLE_TEST) +=	example-test.o
diff --git a/kunit/test-test.c b/kunit/test-test.c
new file mode 100644
index 0000000000000..88f4cdf03db2a
--- /dev/null
+++ b/kunit/test-test.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for core test infrastructure.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+#include <kunit/test.h>
+
+struct kunit_try_catch_test_context {
+	struct kunit_try_catch *try_catch;
+	bool function_called;
+};
+
+void kunit_test_successful_try(void *data)
+{
+	struct kunit *test = data;
+	struct kunit_try_catch_test_context *ctx = test->priv;
+
+	ctx->function_called = true;
+}
+
+void kunit_test_no_catch(void *data)
+{
+	struct kunit *test = data;
+
+	KUNIT_FAIL(test, "Catch should not be called\n");
+}
+
+static void kunit_test_try_catch_successful_try_no_catch(struct kunit *test)
+{
+	struct kunit_try_catch_test_context *ctx = test->priv;
+	struct kunit_try_catch *try_catch = ctx->try_catch;
+
+	kunit_try_catch_init(try_catch,
+			     test,
+			     kunit_test_successful_try,
+			     kunit_test_no_catch);
+	kunit_try_catch_run(try_catch, test);
+
+	KUNIT_EXPECT_TRUE(test, ctx->function_called);
+}
+
+void kunit_test_unsuccessful_try(void *data)
+{
+	struct kunit *test = data;
+	struct kunit_try_catch_test_context *ctx = test->priv;
+	struct kunit_try_catch *try_catch = ctx->try_catch;
+
+	kunit_try_catch_throw(try_catch);
+	KUNIT_FAIL(test, "This line should never be reached\n");
+}
+
+void kunit_test_catch(void *data)
+{
+	struct kunit *test = data;
+	struct kunit_try_catch_test_context *ctx = test->priv;
+
+	ctx->function_called = true;
+}
+
+static void kunit_test_try_catch_unsuccessful_try_does_catch(struct kunit *test)
+{
+	struct kunit_try_catch_test_context *ctx = test->priv;
+	struct kunit_try_catch *try_catch = ctx->try_catch;
+
+	kunit_try_catch_init(try_catch,
+			     test,
+			     kunit_test_unsuccessful_try,
+			     kunit_test_catch);
+	kunit_try_catch_run(try_catch, test);
+
+	KUNIT_EXPECT_TRUE(test, ctx->function_called);
+}
+
+static int kunit_try_catch_test_init(struct kunit *test)
+{
+	struct kunit_try_catch_test_context *ctx;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	test->priv = ctx;
+
+	ctx->try_catch = kunit_kmalloc(test,
+				       sizeof(*ctx->try_catch),
+				       GFP_KERNEL);
+
+	return 0;
+}
+
+static struct kunit_case kunit_try_catch_test_cases[] = {
+	KUNIT_CASE(kunit_test_try_catch_successful_try_no_catch),
+	KUNIT_CASE(kunit_test_try_catch_unsuccessful_try_does_catch),
+	{}
+};
+
+static struct kunit_suite kunit_try_catch_test_suite = {
+	.name = "kunit-try-catch-test",
+	.init = kunit_try_catch_test_init,
+	.test_cases = kunit_try_catch_test_cases,
+};
+kunit_test_suite(kunit_try_catch_test_suite);
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 11/18] kunit: test: add the concept of assertions
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (9 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 10/18] kunit: test: add tests for kunit " Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 12/18] kunit: test: add tests for KUnit managed resources Brendan Higgins
                   ` (6 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add support for assertions which are like expectations except the test
terminates if the assertion is not satisfied.

The idea with assertions is that you use them to state all the
preconditions for your test. Logically speaking, these are the premises
of the test case, so if a premise isn't true, there is no point in
continuing the test case because there are no conclusions that can be
drawn without the premises. Whereas, the expectation is the thing you
are trying to prove. It is not used universally in x-unit style test
frameworks, but I really like it as a convention.  You could still
express the idea of a premise using the above idiom, but I think
KUNIT_ASSERT_* states the intended idea perfectly.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 include/kunit/test.h       | 499 ++++++++++++++++++++++++++++++++++++-
 kunit/string-stream-test.c |  12 +-
 kunit/test-test.c          |   2 +
 kunit/test.c               |  66 +++++
 4 files changed, 570 insertions(+), 9 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 01440f3569847..e97273eb52f55 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -86,9 +86,10 @@ struct kunit;
  * @name: the name of the test case.
  *
  * A test case is a function with the signature, ``void (*)(struct kunit *)``
- * that makes expectations (see KUNIT_EXPECT_TRUE()) about code under test. Each
- * test case is associated with a &struct kunit_suite and will be run after the
- * suite's init function and followed by the suite's exit function.
+ * that makes expectations and assertions (see KUNIT_EXPECT_TRUE() and
+ * KUNIT_ASSERT_TRUE()) about code under test. Each test case is associated with
+ * a &struct kunit_suite and will be run after the suite's init function and
+ * followed by the suite's exit function.
  *
  * A test case should be static and should only be created with the KUNIT_CASE()
  * macro; additionally, every array of test cases should be terminated with an
@@ -836,4 +837,496 @@ do {									       \
 	KUNIT_EXPECT_END(test, !IS_ERR_OR_NULL(__ptr), __stream);	       \
 } while (0)
 
+static inline struct kunit_stream *kunit_assert_start(struct kunit *test,
+						      const char *file,
+						      const char *line)
+{
+	struct kunit_stream *stream = alloc_kunit_stream(test, KERN_ERR);
+
+	kunit_stream_add(stream, "ASSERTION FAILED at %s:%s\n\t", file, line);
+
+	return stream;
+}
+
+static inline void kunit_assert_end(struct kunit *test,
+				    bool success,
+				    struct kunit_stream *stream)
+{
+	if (!success) {
+		kunit_fail(test, stream);
+		kunit_abort(test);
+	} else {
+		kunit_stream_clear(stream);
+	}
+}
+
+#define KUNIT_ASSERT_START(test) \
+		kunit_assert_start(test, __FILE__, __stringify(__LINE__))
+
+#define KUNIT_ASSERT_END(test, success, stream) \
+		kunit_assert_end(test, success, stream)
+
+#define KUNIT_ASSERT(test, success, message) do {			       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+									       \
+	kunit_stream_add(__stream, message);				       \
+	KUNIT_ASSERT_END(test, success, __stream);			       \
+} while (0)
+
+#define KUNIT_ASSERT_MSG(test, success, message, fmt, ...) do {		       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+									       \
+	kunit_stream_add(__stream, message);				       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+	KUNIT_ASSERT_END(test, success, __stream);			       \
+} while (0)
+
+#define KUNIT_ASSERT_FAILURE(test, fmt, ...) do {			       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+									       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+	KUNIT_ASSERT_END(test, false, __stream);			       \
+} while (0)
+
+/**
+ * KUNIT_ASSERT_TRUE() - Sets an assertion that @condition is true.
+ * @test: The test context object.
+ * @condition: an arbitrary boolean expression. The test fails and aborts when
+ * this does not evaluate to true.
+ *
+ * This and assertions of the form `KUNIT_ASSERT_*` will cause the test case to
+ * fail *and immediately abort* when the specified condition is not met. Unlike
+ * an expectation failure, it will prevent the test case from continuing to run;
+ * this is otherwise known as an *assertion failure*.
+ */
+#define KUNIT_ASSERT_TRUE(test, condition)				       \
+		KUNIT_ASSERT(test, (condition),				       \
+			     "Asserted " #condition " is true, but is false\n")
+
+#define KUNIT_ASSERT_TRUE_MSG(test, condition, fmt, ...)		       \
+		KUNIT_ASSERT_MSG(test, (condition),			       \
+				 "Asserted " #condition " is true, but is false\n",\
+				 fmt, ##__VA_ARGS__)
+
+/**
+ * KUNIT_ASSERT_FALSE() - Sets an assertion that @condition is false.
+ * @test: The test context object.
+ * @condition: an arbitrary boolean expression.
+ *
+ * Sets an assertion that the value that @condition evaluates to is false. This
+ * is the same as KUNIT_EXPECT_FALSE(), except it causes an assertion failure
+ * (see KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_FALSE(test, condition)				       \
+		KUNIT_ASSERT(test, !(condition),			       \
+			     "Asserted " #condition " is false, but is true\n")
+
+#define KUNIT_ASSERT_FALSE_MSG(test, condition, fmt, ...)		       \
+		KUNIT_ASSERT_MSG(test, !(condition),			       \
+				 "Asserted " #condition " is false, but is true\n",\
+				 fmt, ##__VA_ARGS__)
+
+void kunit_assert_binary_msg(struct kunit *test,
+			     long long left, const char *left_name,
+			     long long right, const char *right_name,
+			     bool compare_result,
+			     const char *compare_name,
+			     const char *file,
+			     const char *line,
+			     const char *fmt, ...);
+
+static inline void kunit_assert_binary(struct kunit *test,
+				       long long left, const char *left_name,
+				       long long right, const char *right_name,
+				       bool compare_result,
+				       const char *compare_name,
+				       const char *file,
+				       const char *line)
+{
+	kunit_assert_binary_msg(test,
+				left, left_name,
+				right, right_name,
+				compare_result,
+				compare_name,
+				file,
+				line,
+				NULL);
+}
+
+void kunit_assert_ptr_binary_msg(struct kunit *test,
+				 void *left, const char *left_name,
+				 void *right, const char *right_name,
+				 bool compare_result,
+				 const char *compare_name,
+				 const char *file,
+				 const char *line,
+				 const char *fmt, ...);
+
+static inline void kunit_assert_ptr_binary(struct kunit *test,
+					   void *left, const char *left_name,
+					   void *right, const char *right_name,
+					   bool compare_result,
+					   const char *compare_name,
+					   const char *file,
+					   const char *line)
+{
+	kunit_assert_ptr_binary_msg(test,
+				    left, left_name,
+				    right, right_name,
+				    compare_result,
+				    compare_name,
+				    file,
+				    line,
+				    NULL);
+}
+
+/*
+ * A factory macro for defining the expectations for the basic comparisons
+ * defined for the built in types.
+ *
+ * Unfortunately, there is no common type that all types can be promoted to for
+ * which all the binary operators behave the same way as for the actual types
+ * (for example, there is no type that long long and unsigned long long can
+ * both be cast to where the comparison result is preserved for all values). So
+ * the best we can do is do the comparison in the original types and then coerce
+ * everything to long long for printing; this way, the comparison behaves
+ * correctly and the printed out value usually makes sense without
+ * interpretation, but can always be interpretted to figure out the actual
+ * value.
+ */
+#define KUNIT_ASSERT_BINARY(test, left, condition, right) do {		       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_assert_binary(test,					       \
+			    (long long) __left, #left,			       \
+			    (long long) __right, #right,		       \
+			    __left condition __right, #condition,	       \
+			    __FILE__, __stringify(__LINE__));		       \
+} while (0)
+
+#define KUNIT_ASSERT_BINARY_MSG(test, left, condition, right, fmt, ...) do {   \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_assert_binary_msg(test,					       \
+				(long long) __left, #left,		       \
+				(long long) __right, #right,		       \
+				__left condition __right, #condition,	       \
+				__FILE__, __stringify(__LINE__),	       \
+				fmt, ##__VA_ARGS__);			       \
+} while (0)
+
+/*
+ * Just like KUNIT_EXPECT_BINARY, but for comparing pointer types.
+ */
+#define KUNIT_ASSERT_PTR_BINARY(test, left, condition, right) do {	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_assert_ptr_binary(test,					       \
+				(void *) __left, #left,			       \
+				(void *) __right, #right,		       \
+				__left condition __right, #condition,	       \
+				__FILE__, __stringify(__LINE__));	       \
+} while (0)
+
+#define KUNIT_ASSERT_PTR_BINARY_MSG(test, left, condition, right, fmt, ...)    \
+do {									       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+	__kunit_typecheck(__left, __right);				       \
+	kunit_assert_ptr_binary_msg(test,				       \
+				    (void *) __left, #left,		       \
+				    (void *) __right, #right,		       \
+				    __left condition __right, #condition,      \
+				    __FILE__, __stringify(__LINE__),	       \
+				    fmt, ##__VA_ARGS__);		       \
+} while (0)
+
+/**
+ * KUNIT_ASSERT_EQ() - Sets an assertion that @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an assertion that the values that @left and @right evaluate to are
+ * equal. This is the same as KUNIT_EXPECT_EQ(), except it causes an assertion
+ * failure (see KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_EQ(test, left, right) \
+		KUNIT_ASSERT_BINARY(test, left, ==, right)
+
+#define KUNIT_ASSERT_EQ_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_BINARY_MSG(test,				       \
+					left,				       \
+					==,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_ASSERT_PTR_EQ() - Asserts that pointers @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a pointer.
+ * @right: an arbitrary expression that evaluates to a pointer.
+ *
+ * Sets an assertion that the values that @left and @right evaluate to are
+ * equal. This is the same as KUNIT_EXPECT_EQ(), except it causes an assertion
+ * failure (see KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_PTR_EQ(test, left, right) \
+		KUNIT_ASSERT_PTR_BINARY(test, left, ==, right)
+
+#define KUNIT_ASSERT_PTR_EQ_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_PTR_BINARY_MSG(test,			       \
+					    left,			       \
+					    ==,				       \
+					    right,			       \
+					    fmt,			       \
+					    ##__VA_ARGS__)
+
+/**
+ * KUNIT_ASSERT_NE() - An assertion that @left and @right are not equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an assertion that the values that @left and @right evaluate to are not
+ * equal. This is the same as KUNIT_EXPECT_NE(), except it causes an assertion
+ * failure (see KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_NE(test, left, right) \
+		KUNIT_ASSERT_BINARY(test, left, !=, right)
+
+#define KUNIT_ASSERT_NE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_BINARY_MSG(test,				       \
+					left,				       \
+					!=,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_ASSERT_PTR_NE() - Asserts that pointers @left and @right are not equal.
+ * KUNIT_ASSERT_PTR_EQ() - Asserts that pointers @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a pointer.
+ * @right: an arbitrary expression that evaluates to a pointer.
+ *
+ * Sets an assertion that the values that @left and @right evaluate to are not
+ * equal. This is the same as KUNIT_EXPECT_NE(), except it causes an assertion
+ * failure (see KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_PTR_NE(test, left, right) \
+		KUNIT_ASSERT_PTR_BINARY(test, left, !=, right)
+
+#define KUNIT_ASSERT_PTR_NE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_PTR_BINARY_MSG(test,			       \
+					    left,			       \
+					    !=,				       \
+					    right,			       \
+					    fmt,			       \
+					    ##__VA_ARGS__)
+/**
+ * KUNIT_ASSERT_LT() - An assertion that @left is less than @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an assertion that the value that @left evaluates to is less than the
+ * value that @right evaluates to. This is the same as KUNIT_EXPECT_LT(), except
+ * it causes an assertion failure (see KUNIT_ASSERT_TRUE()) when the assertion
+ * is not met.
+ */
+#define KUNIT_ASSERT_LT(test, left, right) \
+		KUNIT_ASSERT_BINARY(test, left, <, right)
+
+#define KUNIT_ASSERT_LT_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_BINARY_MSG(test,				       \
+					left,				       \
+					<,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+/**
+ * KUNIT_ASSERT_LE() - An assertion that @left is less than or equal to @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an assertion that the value that @left evaluates to is less than or
+ * equal to the value that @right evaluates to. This is the same as
+ * KUNIT_EXPECT_LE(), except it causes an assertion failure (see
+ * KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_LE(test, left, right) \
+		KUNIT_ASSERT_BINARY(test, left, <=, right)
+
+#define KUNIT_ASSERT_LE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_BINARY_MSG(test,				       \
+					left,				       \
+					<=,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+/**
+ * KUNIT_ASSERT_GT() - An assertion that @left is greater than @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an assertion that the value that @left evaluates to is greater than the
+ * value that @right evaluates to. This is the same as KUNIT_EXPECT_GT(), except
+ * it causes an assertion failure (see KUNIT_ASSERT_TRUE()) when the assertion
+ * is not met.
+ */
+#define KUNIT_ASSERT_GT(test, left, right) \
+		KUNIT_ASSERT_BINARY(test, left, >, right)
+
+#define KUNIT_ASSERT_GT_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_BINARY_MSG(test,				       \
+					left,				       \
+					>,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_ASSERT_GE() - Assertion that @left is greater than or equal to @right.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a primitive C type.
+ * @right: an arbitrary expression that evaluates to a primitive C type.
+ *
+ * Sets an assertion that the value that @left evaluates to is greater than the
+ * value that @right evaluates to. This is the same as KUNIT_EXPECT_GE(), except
+ * it causes an assertion failure (see KUNIT_ASSERT_TRUE()) when the assertion
+ * is not met.
+ */
+#define KUNIT_ASSERT_GE(test, left, right) \
+		KUNIT_ASSERT_BINARY(test, left, >=, right)
+
+#define KUNIT_ASSERT_GE_MSG(test, left, right, fmt, ...)		       \
+		KUNIT_ASSERT_BINARY_MSG(test,				       \
+					left,				       \
+					>=,				       \
+					right,				       \
+					fmt,				       \
+					##__VA_ARGS__)
+
+/**
+ * KUNIT_ASSERT_STREQ() - An assertion that strings @left and @right are equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a null terminated string.
+ * @right: an arbitrary expression that evaluates to a null terminated string.
+ *
+ * Sets an assertion that the values that @left and @right evaluate to are
+ * equal. This is the same as KUNIT_EXPECT_STREQ(), except it causes an
+ * assertion failure (see KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_STREQ(test, left, right) do {			       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Asserted " #left " == " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+									       \
+	KUNIT_ASSERT_END(test, !strcmp(left, right), __stream);		       \
+} while (0)
+
+#define KUNIT_ASSERT_STREQ_MSG(test, left, right, fmt, ...) do {	       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Asserted " #left " == " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+									       \
+	KUNIT_ASSERT_END(test, !strcmp(left, right), __stream);		       \
+} while (0)
+
+/**
+ * KUNIT_ASSERT_STRNEQ() - Expects that strings @left and @right are not equal.
+ * @test: The test context object.
+ * @left: an arbitrary expression that evaluates to a null terminated string.
+ * @right: an arbitrary expression that evaluates to a null terminated string.
+ *
+ * Sets an expectation that the values that @left and @right evaluate to are
+ * not equal. This is semantically equivalent to
+ * KUNIT_ASSERT_TRUE(@test, strcmp((@left), (@right))). See KUNIT_ASSERT_TRUE()
+ * for more information.
+ */
+#define KUNIT_ASSERT_STRNEQ(test, left, right) do {			       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Asserted " #left " == " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+									       \
+	KUNIT_ASSERT_END(test, strcmp(left, right), __stream);		       \
+} while (0)
+
+#define KUNIT_ASSERT_STRNEQ_MSG(test, left, right, fmt, ...) do {	       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+	typeof(left) __left = (left);					       \
+	typeof(right) __right = (right);				       \
+									       \
+	kunit_stream_add(__stream, "Asserted " #left " == " #right ", but\n"); \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #left, __left);	       \
+	kunit_stream_add(__stream, "\t\t%s == %s\n", #right, __right);	       \
+	kunit_stream_add(__stream, fmt, ##__VA_ARGS__);			       \
+									       \
+	KUNIT_ASSERT_END(test, strcmp(left, right), __stream);		       \
+} while (0)
+
+/**
+ * KUNIT_ASSERT_NOT_ERR_OR_NULL() - Assertion that @ptr is not null and not err.
+ * @test: The test context object.
+ * @ptr: an arbitrary pointer.
+ *
+ * Sets an assertion that the value that @ptr evaluates to is not null and not
+ * an errno stored in a pointer. This is the same as
+ * KUNIT_EXPECT_NOT_ERR_OR_NULL(), except it causes an assertion failure (see
+ * KUNIT_ASSERT_TRUE()) when the assertion is not met.
+ */
+#define KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr) do {			       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+	typeof(ptr) __ptr = (ptr);					       \
+									       \
+	if (!__ptr)							       \
+		kunit_stream_add(__stream,				       \
+				 "Asserted " #ptr " is not null, but is\n");  \
+	if (IS_ERR(__ptr))						       \
+		kunit_stream_add(__stream,				       \
+				 "Asserted " #ptr " is not error, but is: %ld\n",\
+				 PTR_ERR(__ptr));			       \
+									       \
+	KUNIT_ASSERT_END(test, !IS_ERR_OR_NULL(__ptr), __stream);	       \
+} while (0)
+
+#define KUNIT_ASSERT_NOT_ERR_OR_NULL_MSG(test, ptr, fmt, ...) do {	       \
+	struct kunit_stream *__stream = KUNIT_ASSERT_START(test);	       \
+	typeof(ptr) __ptr = (ptr);					       \
+									       \
+	if (!__ptr) {							       \
+		kunit_stream_add(__stream,				       \
+				 "Asserted " #ptr " is not null, but is\n");  \
+		kunit_stream_add(__stream, fmt, ##__VA_ARGS__);		       \
+	}								       \
+	if (IS_ERR(__ptr)) {						       \
+		kunit_stream_add(__stream,				       \
+				 "Asserted " #ptr " is not error, but is: %ld\n",\
+				 PTR_ERR(__ptr));			       \
+									       \
+		kunit_stream_add(__stream, fmt, ##__VA_ARGS__);		       \
+	}								       \
+	KUNIT_ASSERT_END(test, !IS_ERR_OR_NULL(__ptr), __stream);	       \
+} while (0)
+
 #endif /* _KUNIT_TEST_H */
diff --git a/kunit/string-stream-test.c b/kunit/string-stream-test.c
index b5641b078b8f6..5f27d576d2daf 100644
--- a/kunit/string-stream-test.c
+++ b/kunit/string-stream-test.c
@@ -34,7 +34,7 @@ static void string_stream_test_get_string(struct kunit *test)
 	string_stream_add(stream, " %s", "bar");
 
 	output = string_stream_get_string(stream);
-	KUNIT_EXPECT_STREQ(test, output, "Foo bar");
+	KUNIT_ASSERT_STREQ(test, output, "Foo bar");
 	kfree(output);
 }
 
@@ -48,16 +48,16 @@ static void string_stream_test_add_and_clear(struct kunit *test)
 		string_stream_add(stream, "A");
 
 	output = string_stream_get_string(stream);
-	KUNIT_EXPECT_STREQ(test, output, "AAAAAAAAAA");
-	KUNIT_EXPECT_EQ(test, stream->length, (size_t)10);
-	KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+	KUNIT_ASSERT_STREQ(test, output, "AAAAAAAAAA");
+	KUNIT_ASSERT_EQ(test, stream->length, (size_t)10);
+	KUNIT_ASSERT_FALSE(test, string_stream_is_empty(stream));
 	kfree(output);
 
 	string_stream_clear(stream);
 
 	output = string_stream_get_string(stream);
-	KUNIT_EXPECT_STREQ(test, output, "");
-	KUNIT_EXPECT_TRUE(test, string_stream_is_empty(stream));
+	KUNIT_ASSERT_STREQ(test, output, "");
+	KUNIT_ASSERT_TRUE(test, string_stream_is_empty(stream));
 }
 
 static struct kunit_case string_stream_test_cases[] = {
diff --git a/kunit/test-test.c b/kunit/test-test.c
index 88f4cdf03db2a..058f3fb37458a 100644
--- a/kunit/test-test.c
+++ b/kunit/test-test.c
@@ -78,11 +78,13 @@ static int kunit_try_catch_test_init(struct kunit *test)
 	struct kunit_try_catch_test_context *ctx;
 
 	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
 	test->priv = ctx;
 
 	ctx->try_catch = kunit_kmalloc(test,
 				       sizeof(*ctx->try_catch),
 				       GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->try_catch);
 
 	return 0;
 }
diff --git a/kunit/test.c b/kunit/test.c
index 731f3c9eecf20..52b818d756704 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -501,3 +501,69 @@ void kunit_expect_ptr_binary_msg(struct kunit *test,
 
 	kunit_expect_end(test, compare_result, stream);
 }
+
+void kunit_assert_binary_msg(struct kunit *test,
+			     long long left, const char *left_name,
+			     long long right, const char *right_name,
+			     bool compare_result,
+			     const char *compare_name,
+			     const char *file,
+			     const char *line,
+			     const char *fmt, ...)
+{
+	struct kunit_stream *stream = kunit_assert_start(test, file, line);
+	struct va_format vaf;
+	va_list args;
+
+	kunit_stream_add(stream,
+			 "Asserted %s %s %s, but\n",
+			 left_name, compare_name, right_name);
+	kunit_stream_add(stream, "\t\t%s == %lld\n", left_name, left);
+	kunit_stream_add(stream, "\t\t%s == %lld\n", right_name, right);
+
+	if (fmt) {
+		va_start(args, fmt);
+
+		vaf.fmt = fmt;
+		vaf.va = &args;
+
+		kunit_stream_add(stream, "\n%pV", &vaf);
+
+		va_end(args);
+	}
+
+	kunit_assert_end(test, compare_result, stream);
+}
+
+void kunit_assert_ptr_binary_msg(struct kunit *test,
+				 void *left, const char *left_name,
+				 void *right, const char *right_name,
+				 bool compare_result,
+				 const char *compare_name,
+				 const char *file,
+				 const char *line,
+				 const char *fmt, ...)
+{
+	struct kunit_stream *stream = kunit_assert_start(test, file, line);
+	struct va_format vaf;
+	va_list args;
+
+	kunit_stream_add(stream,
+			 "Asserted %s %s %s, but\n",
+			 left_name, compare_name, right_name);
+	kunit_stream_add(stream, "\t\t%s == %pK\n", left_name, left);
+	kunit_stream_add(stream, "\t\t%s == %pK", right_name, right);
+
+	if (fmt) {
+		va_start(args, fmt);
+
+		vaf.fmt = fmt;
+		vaf.va = &args;
+
+		kunit_stream_add(stream, "\n%pV", &vaf);
+
+		va_end(args);
+	}
+
+	kunit_assert_end(test, compare_result, stream);
+}
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 12/18] kunit: test: add tests for KUnit managed resources
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (10 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 11/18] kunit: test: add the concept of assertions Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 13/18] kunit: tool: add Python wrappers for running KUnit tests Brendan Higgins
                   ` (5 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Avinash Kondareddy, Brendan Higgins

From: Avinash Kondareddy <akndr41@gmail.com>

Add unit tests for KUnit managed resources. KUnit managed resources
(struct kunit_resource) are resources that are automatically cleaned up
at the end of a KUnit test, similar to the concept of devm_* managed
resources.

Signed-off-by: Avinash Kondareddy <akndr41@gmail.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 kunit/test-test.c | 219 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 219 insertions(+)

diff --git a/kunit/test-test.c b/kunit/test-test.c
index 058f3fb37458a..b044659fe868b 100644
--- a/kunit/test-test.c
+++ b/kunit/test-test.c
@@ -101,3 +101,222 @@ static struct kunit_suite kunit_try_catch_test_suite = {
 	.test_cases = kunit_try_catch_test_cases,
 };
 kunit_test_suite(kunit_try_catch_test_suite);
+
+/*
+ * Context for testing test managed resources
+ * is_resource_initialized is used to test arbitrary resources
+ */
+struct kunit_test_resource_context {
+	struct kunit test;
+	bool is_resource_initialized;
+	int allocate_order[2];
+	int free_order[2];
+};
+
+static int fake_resource_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_test_resource_context *ctx = context;
+
+	res->allocation = &ctx->is_resource_initialized;
+	ctx->is_resource_initialized = true;
+	return 0;
+}
+
+static void fake_resource_free(struct kunit_resource *res)
+{
+	bool *is_resource_initialized = res->allocation;
+
+	*is_resource_initialized = false;
+}
+
+static void kunit_resource_test_init_resources(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+
+	kunit_init_test(&ctx->test, "testing_test_init_test");
+
+	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
+}
+
+static void kunit_resource_test_alloc_resource(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+	struct kunit_resource *res;
+	kunit_resource_free_t free = fake_resource_free;
+
+	res = kunit_alloc_resource(&ctx->test,
+				   fake_resource_init,
+				   fake_resource_free,
+				   ctx);
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, res);
+	KUNIT_EXPECT_PTR_EQ(test,
+			    &ctx->is_resource_initialized,
+			    (bool *) res->allocation);
+	KUNIT_EXPECT_TRUE(test, list_is_last(&res->node, &ctx->test.resources));
+	KUNIT_EXPECT_PTR_EQ(test, free, res->free);
+}
+
+static void kunit_resource_test_free_resource(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+	struct kunit_resource *res = kunit_alloc_resource(&ctx->test,
+							  fake_resource_init,
+							  fake_resource_free,
+							  ctx);
+
+	kunit_free_resource(&ctx->test, res);
+
+	KUNIT_EXPECT_FALSE(test, ctx->is_resource_initialized);
+	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
+}
+
+static void kunit_resource_test_cleanup_resources(struct kunit *test)
+{
+	int i;
+	struct kunit_test_resource_context *ctx = test->priv;
+	struct kunit_resource *resources[5];
+
+	for (i = 0; i < ARRAY_SIZE(resources); i++) {
+		resources[i] = kunit_alloc_resource(&ctx->test,
+						    fake_resource_init,
+						    fake_resource_free,
+						    ctx);
+	}
+
+	kunit_cleanup(&ctx->test);
+
+	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
+}
+
+static void kunit_resource_test_mark_order(int order_array[],
+					   size_t order_size,
+					   int key)
+{
+	int i;
+
+	for (i = 0; i < order_size && order_array[i]; i++)
+		;
+
+	order_array[i] = key;
+}
+
+#define KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, order_field, key)		       \
+		kunit_resource_test_mark_order(ctx->order_field,	       \
+					       ARRAY_SIZE(ctx->order_field),   \
+					       key)
+
+static int fake_resource_2_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_test_resource_context *ctx = context;
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, allocate_order, 2);
+
+	res->allocation = ctx;
+
+	return 0;
+}
+
+static void fake_resource_2_free(struct kunit_resource *res)
+{
+	struct kunit_test_resource_context *ctx = res->allocation;
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, free_order, 2);
+}
+
+static int fake_resource_1_init(struct kunit_resource *res, void *context)
+{
+	struct kunit_test_resource_context *ctx = context;
+
+	kunit_alloc_resource(&ctx->test,
+			     fake_resource_2_init,
+			     fake_resource_2_free,
+			     ctx);
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, allocate_order, 1);
+
+	res->allocation = ctx;
+
+	return 0;
+}
+
+static void fake_resource_1_free(struct kunit_resource *res)
+{
+	struct kunit_test_resource_context *ctx = res->allocation;
+
+	KUNIT_RESOURCE_TEST_MARK_ORDER(ctx, free_order, 1);
+}
+
+/*
+ * TODO(brendanhiggins@google.com): replace the arrays that keep track of the
+ * order of allocation and freeing with strict mocks using the IN_SEQUENCE macro
+ * to assert allocation and freeing order when the feature becomes available.
+ */
+static void kunit_resource_test_proper_free_ordering(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+
+	/* fake_resource_1 allocates a fake_resource_2 in its init. */
+	kunit_alloc_resource(&ctx->test,
+			     fake_resource_1_init,
+			     fake_resource_1_free,
+			     ctx);
+
+	/*
+	 * Since fake_resource_2_init calls KUNIT_RESOURCE_TEST_MARK_ORDER
+	 * before returning to fake_resource_1_init, it should be the first to
+	 * put its key in the allocate_order array.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->allocate_order[0], 2);
+	KUNIT_EXPECT_EQ(test, ctx->allocate_order[1], 1);
+
+	kunit_cleanup(&ctx->test);
+
+	/*
+	 * Because fake_resource_2 finishes allocation before fake_resource_1,
+	 * fake_resource_1 should be freed first since it could depend on
+	 * fake_resource_2.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->free_order[0], 1);
+	KUNIT_EXPECT_EQ(test, ctx->free_order[1], 2);
+}
+
+static int kunit_resource_test_init(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx =
+			kzalloc(sizeof(*ctx), GFP_KERNEL);
+
+	if (!ctx)
+		return -ENOMEM;
+
+	test->priv = ctx;
+
+	kunit_init_test(&ctx->test, "test_test_context");
+
+	return 0;
+}
+
+static void kunit_resource_test_exit(struct kunit *test)
+{
+	struct kunit_test_resource_context *ctx = test->priv;
+
+	kunit_cleanup(&ctx->test);
+	kfree(ctx);
+}
+
+static struct kunit_case kunit_resource_test_cases[] = {
+	KUNIT_CASE(kunit_resource_test_init_resources),
+	KUNIT_CASE(kunit_resource_test_alloc_resource),
+	KUNIT_CASE(kunit_resource_test_free_resource),
+	KUNIT_CASE(kunit_resource_test_cleanup_resources),
+	KUNIT_CASE(kunit_resource_test_proper_free_ordering),
+	{}
+};
+
+static struct kunit_suite kunit_resource_test_suite = {
+	.name = "kunit-resource-test",
+	.init = kunit_resource_test_init,
+	.exit = kunit_resource_test_exit,
+	.test_cases = kunit_resource_test_cases,
+};
+kunit_test_suite(kunit_resource_test_suite);
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 13/18] kunit: tool: add Python wrappers for running KUnit tests
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (11 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 12/18] kunit: test: add tests for KUnit managed resources Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 14/18] kunit: defconfig: add defconfigs for building " Brendan Higgins
                   ` (4 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Felix Guo, Brendan Higgins

From: Felix Guo <felixguoxiuping@gmail.com>

The ultimate goal is to create minimal isolated test binaries; in the
meantime we are using UML to provide the infrastructure to run tests, so
define an abstract way to configure and run tests that allow us to
change the context in which tests are built without affecting the user.
This also makes pretty and dynamic error reporting, and a lot of other
nice features easier.

kunit_config.py:
  - parse .config and Kconfig files.

kunit_kernel.py: provides helper functions to:
  - configure the kernel using kunitconfig.
  - build the kernel with the appropriate configuration.
  - provide function to invoke the kernel and stream the output back.

kunit_parser.py: parses raw logs returned out by kunit_kernel and
displays them in a user friendly way.

test_data/*: samples of test data for testing kunit.py, kunit_config.py,
etc.

Signed-off-by: Felix Guo <felixguoxiuping@gmail.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 tools/testing/kunit/.gitignore                |   3 +
 tools/testing/kunit/kunit.py                  | 116 +++++++
 tools/testing/kunit/kunit_config.py           |  66 ++++
 tools/testing/kunit/kunit_kernel.py           | 148 +++++++++
 tools/testing/kunit/kunit_parser.py           | 290 ++++++++++++++++++
 tools/testing/kunit/kunit_tool_test.py        | 206 +++++++++++++
 .../test_is_test_passed-all_passed.log        |  32 ++
 .../test_data/test_is_test_passed-crash.log   |  69 +++++
 .../test_data/test_is_test_passed-failure.log |  36 +++
 .../test_is_test_passed-no_tests_run.log      |  75 +++++
 .../test_output_isolated_correctly.log        | 106 +++++++
 .../test_data/test_read_from_file.kconfig     |  17 +
 12 files changed, 1164 insertions(+)
 create mode 100644 tools/testing/kunit/.gitignore
 create mode 100755 tools/testing/kunit/kunit.py
 create mode 100644 tools/testing/kunit/kunit_config.py
 create mode 100644 tools/testing/kunit/kunit_kernel.py
 create mode 100644 tools/testing/kunit/kunit_parser.py
 create mode 100755 tools/testing/kunit/kunit_tool_test.py
 create mode 100644 tools/testing/kunit/test_data/test_is_test_passed-all_passed.log
 create mode 100644 tools/testing/kunit/test_data/test_is_test_passed-crash.log
 create mode 100644 tools/testing/kunit/test_data/test_is_test_passed-failure.log
 create mode 100644 tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log
 create mode 100644 tools/testing/kunit/test_data/test_output_isolated_correctly.log
 create mode 100644 tools/testing/kunit/test_data/test_read_from_file.kconfig

diff --git a/tools/testing/kunit/.gitignore b/tools/testing/kunit/.gitignore
new file mode 100644
index 0000000000000..c791ff59a37a9
--- /dev/null
+++ b/tools/testing/kunit/.gitignore
@@ -0,0 +1,3 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
\ No newline at end of file
diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
new file mode 100755
index 0000000000000..da11bd62a4b82
--- /dev/null
+++ b/tools/testing/kunit/kunit.py
@@ -0,0 +1,116 @@
+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# A thin wrapper on top of the KUnit Kernel
+#
+# Copyright (C) 2019, Google LLC.
+# Author: Felix Guo <felixguoxiuping@gmail.com>
+# Author: Brendan Higgins <brendanhiggins@google.com>
+
+import argparse
+import sys
+import os
+import time
+
+from collections import namedtuple
+from enum import Enum, auto
+
+import kunit_config
+import kunit_kernel
+import kunit_parser
+
+KunitResult = namedtuple('KunitResult', ['status','result'])
+
+KunitRequest = namedtuple('KunitRequest', ['raw_output','timeout', 'jobs', 'build_dir'])
+
+class KunitStatus(Enum):
+	SUCCESS = auto()
+	CONFIG_FAILURE = auto()
+	BUILD_FAILURE = auto()
+	TEST_FAILURE = auto()
+
+def run_tests(linux: kunit_kernel.LinuxSourceTree,
+	      request: KunitRequest) -> KunitResult:
+	config_start = time.time()
+	success = linux.build_reconfig(request.build_dir)
+	config_end = time.time()
+	if not success:
+		return KunitResult(KunitStatus.CONFIG_FAILURE, 'could not configure kernel')
+
+	kunit_parser.print_with_timestamp('Building KUnit Kernel ...')
+
+	build_start = time.time()
+	success = linux.build_um_kernel(request.jobs, request.build_dir)
+	build_end = time.time()
+	if not success:
+		return KunitResult(KunitStatus.BUILD_FAILURE, 'could not build kernel')
+
+	kunit_parser.print_with_timestamp('Starting KUnit Kernel ...')
+	test_start = time.time()
+
+	test_result = kunit_parser.TestResult(kunit_parser.TestStatus.SUCCESS,
+					      [],
+					      'Tests not Parsed.')
+	if request.raw_output:
+		kunit_parser.raw_output(
+			linux.run_kernel(timeout=request.timeout))
+	else:
+		kunit_output = linux.run_kernel(timeout=request.timeout)
+		test_result = kunit_parser.parse_run_tests(kunit_output)
+	test_end = time.time()
+
+	kunit_parser.print_with_timestamp((
+		'Elapsed time: %.3fs total, %.3fs configuring, %.3fs ' +
+		'building, %.3fs running\n') % (
+				test_end - config_start,
+				config_end - config_start,
+				build_end - build_start,
+				test_end - test_start))
+
+	if test_result.status != kunit_parser.TestStatus.SUCCESS:
+		return KunitResult(KunitStatus.TEST_FAILURE, test_result)
+	else:
+		return KunitResult(KunitStatus.SUCCESS, test_result)
+
+def main(argv, linux):
+	parser = argparse.ArgumentParser(
+			description='Helps writing and running KUnit tests.')
+	subparser = parser.add_subparsers(dest='subcommand')
+
+	run_parser = subparser.add_parser('run', help='Runs KUnit tests.')
+	run_parser.add_argument('--raw_output', help='don\'t format output from kernel',
+				action='store_true')
+
+	run_parser.add_argument('--timeout',
+				help='maximum number of seconds to allow for all tests '
+				'to run. This does not include time taken to build the '
+				'tests.',
+				type=int,
+				default=300,
+				metavar='timeout')
+
+	run_parser.add_argument('--jobs',
+				help='As in the make command, "Specifies  the number of '
+				'jobs (commands) to run simultaneously."',
+				type=int, default=8, metavar='jobs')
+
+	run_parser.add_argument('--build_dir',
+				help='As in the make command, it specifies the build '
+				'directory.',
+				type=str, default=None, metavar='build_dir')
+
+	cli_args = parser.parse_args(argv)
+
+	if cli_args.subcommand == 'run':
+		request = KunitRequest(cli_args.raw_output,
+				       cli_args.timeout,
+				       cli_args.jobs,
+				       cli_args.build_dir)
+		result = run_tests(linux, request)
+		if result.status != KunitStatus.SUCCESS:
+			sys.exit(1)
+	else:
+		parser.print_help()
+
+if __name__ == '__main__':
+	main(sys.argv[1:], kunit_kernel.LinuxSourceTree())
diff --git a/tools/testing/kunit/kunit_config.py b/tools/testing/kunit/kunit_config.py
new file mode 100644
index 0000000000000..ebf3942b23f51
--- /dev/null
+++ b/tools/testing/kunit/kunit_config.py
@@ -0,0 +1,66 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Builds a .config from a kunitconfig.
+#
+# Copyright (C) 2019, Google LLC.
+# Author: Felix Guo <felixguoxiuping@gmail.com>
+# Author: Brendan Higgins <brendanhiggins@google.com>
+
+import collections
+import re
+
+CONFIG_IS_NOT_SET_PATTERN = r'^# CONFIG_\w+ is not set$'
+CONFIG_PATTERN = r'^CONFIG_\w+=\S+$'
+
+KconfigEntryBase = collections.namedtuple('KconfigEntry', ['raw_entry'])
+
+
+class KconfigEntry(KconfigEntryBase):
+
+	def __str__(self) -> str:
+		return self.raw_entry
+
+
+class KconfigParseError(Exception):
+	"""Error parsing Kconfig defconfig or .config."""
+
+
+class Kconfig(object):
+	"""Represents defconfig or .config specified using the Kconfig language."""
+
+	def __init__(self):
+		self._entries = []
+
+	def entries(self):
+		return set(self._entries)
+
+	def add_entry(self, entry: KconfigEntry) -> None:
+		self._entries.append(entry)
+
+	def is_subset_of(self, other: 'Kconfig') -> bool:
+		return self.entries().issubset(other.entries())
+
+	def write_to_file(self, path: str) -> None:
+		with open(path, 'w') as f:
+			for entry in self.entries():
+				f.write(str(entry) + '\n')
+
+	def parse_from_string(self, blob: str) -> None:
+		"""Parses a string containing KconfigEntrys and populates this Kconfig."""
+		self._entries = []
+		is_not_set_matcher = re.compile(CONFIG_IS_NOT_SET_PATTERN)
+		config_matcher = re.compile(CONFIG_PATTERN)
+		for line in blob.split('\n'):
+			line = line.strip()
+			if not line:
+				continue
+			elif config_matcher.match(line) or is_not_set_matcher.match(line):
+				self._entries.append(KconfigEntry(line))
+			elif line[0] == '#':
+				continue
+			else:
+				raise KconfigParseError('Failed to parse: ' + line)
+
+	def read_from_file(self, path: str) -> None:
+		with open(path, 'r') as f:
+			self.parse_from_string(f.read())
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
new file mode 100644
index 0000000000000..07c0abf2f47df
--- /dev/null
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -0,0 +1,148 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Runs UML kernel, collects output, and handles errors.
+#
+# Copyright (C) 2019, Google LLC.
+# Author: Felix Guo <felixguoxiuping@gmail.com>
+# Author: Brendan Higgins <brendanhiggins@google.com>
+
+
+import logging
+import subprocess
+import os
+
+import kunit_config
+
+KCONFIG_PATH = '.config'
+
+class ConfigError(Exception):
+	"""Represents an error trying to configure the Linux kernel."""
+
+
+class BuildError(Exception):
+	"""Represents an error trying to build the Linux kernel."""
+
+
+class LinuxSourceTreeOperations(object):
+	"""An abstraction over command line operations performed on a source tree."""
+
+	def make_mrproper(self):
+		try:
+			subprocess.check_output(['make', 'mrproper'])
+		except OSError as e:
+			raise ConfigError('Could not call make command: ' + e)
+		except subprocess.CalledProcessError as e:
+			raise ConfigError(e.output)
+
+	def make_olddefconfig(self, build_dir):
+		command = ['make', 'ARCH=um', 'olddefconfig']
+		if build_dir:
+			command += ['O=' + build_dir]
+		try:
+			subprocess.check_output(command)
+		except OSError as e:
+			raise ConfigError('Could not call make command: ' + e)
+		except subprocess.CalledProcessError as e:
+			raise ConfigError(e.output)
+
+	def make(self, jobs, build_dir):
+		command = ['make', 'ARCH=um', '--jobs=' + str(jobs)]
+		if build_dir:
+			command += ['O=' + build_dir]
+		try:
+			subprocess.check_output(command)
+		except OSError as e:
+			raise BuildError('Could not call execute make: ' + e)
+		except subprocess.CalledProcessError as e:
+			raise BuildError(e.output)
+
+	def linux_bin(self, params, timeout, build_dir):
+		"""Runs the Linux UML binary. Must be named 'linux'."""
+		linux_bin = './linux'
+		if build_dir:
+			linux_bin = os.path.join(build_dir, 'linux')
+		process = subprocess.Popen(
+			[linux_bin] + params,
+			stdin=subprocess.PIPE,
+			stdout=subprocess.PIPE,
+			stderr=subprocess.PIPE)
+		process.wait(timeout=timeout)
+		return process
+
+
+def get_kconfig_path(build_dir):
+	kconfig_path = KCONFIG_PATH
+	if build_dir:
+		kconfig_path = os.path.join(build_dir, KCONFIG_PATH)
+	return kconfig_path
+
+class LinuxSourceTree(object):
+	"""Represents a Linux kernel source tree with KUnit tests."""
+
+	def __init__(self):
+		self._kconfig = kunit_config.Kconfig()
+		self._kconfig.read_from_file('kunitconfig')
+		self._ops = LinuxSourceTreeOperations()
+
+	def clean(self):
+		try:
+			self._ops.make_mrproper()
+		except ConfigError as e:
+			logging.error(e)
+			return False
+		return True
+
+	def build_config(self, build_dir):
+		kconfig_path = get_kconfig_path(build_dir)
+		if build_dir and not os.path.exists(build_dir):
+			os.mkdir(build_dir)
+		self._kconfig.write_to_file(kconfig_path)
+		try:
+			self._ops.make_olddefconfig(build_dir)
+		except ConfigError as e:
+			logging.error(e)
+			return False
+		validated_kconfig = kunit_config.Kconfig()
+		validated_kconfig.read_from_file(kconfig_path)
+		if not self._kconfig.is_subset_of(validated_kconfig):
+			logging.error('Provided Kconfig is not contained in validated .config!')
+			return False
+		return True
+
+	def build_reconfig(self, build_dir):
+		"""Creates a new .config if it is not a subset of the kunitconfig."""
+		kconfig_path = get_kconfig_path(build_dir)
+		if os.path.exists(kconfig_path):
+			existing_kconfig = kunit_config.Kconfig()
+			existing_kconfig.read_from_file(kconfig_path)
+			if not self._kconfig.is_subset_of(existing_kconfig):
+				print('Regenerating .config ...')
+				os.remove(kconfig_path)
+				return self.build_config(build_dir)
+			else:
+				return True
+		else:
+			print('Generating .config ...')
+			return self.build_config(build_dir)
+
+	def build_um_kernel(self, jobs, build_dir):
+		try:
+			self._ops.make_olddefconfig(build_dir)
+			self._ops.make(jobs, build_dir)
+		except (ConfigError, BuildError) as e:
+			logging.error(e)
+			return False
+		used_kconfig = kunit_config.Kconfig()
+		used_kconfig.read_from_file(get_kconfig_path(build_dir))
+		if not self._kconfig.is_subset_of(used_kconfig):
+			logging.error('Provided Kconfig is not contained in final config!')
+			return False
+		return True
+
+	def run_kernel(self, args=[], timeout=None, build_dir=None):
+		args.extend(['mem=256M'])
+		process = self._ops.linux_bin(args, timeout, build_dir)
+		with open('test.log', 'w') as f:
+			for line in process.stdout:
+				f.write(line.rstrip().decode('ascii') + '\n')
+				yield line.rstrip().decode('ascii')
diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
new file mode 100644
index 0000000000000..f27f3d675c3bb
--- /dev/null
+++ b/tools/testing/kunit/kunit_parser.py
@@ -0,0 +1,290 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Parses test results from a kernel dmesg log.
+#
+# Copyright (C) 2019, Google LLC.
+# Author: Felix Guo <felixguoxiuping@gmail.com>
+# Author: Brendan Higgins <brendanhiggins@google.com>
+
+import re
+
+from collections import namedtuple
+from datetime import datetime
+from enum import Enum, auto
+from functools import reduce
+from typing import List
+
+TestResult = namedtuple('TestResult', ['status','suites','log'])
+
+class TestSuite(object):
+	def __init__(self):
+		self.status = None
+		self.name = None
+		self.cases = []
+
+	def __str__(self):
+		return 'TestSuite(' + self.status + ',' + self.name + ',' + str(self.cases) + ')'
+
+	def __repr__(self):
+		return str(self)
+
+class TestCase(object):
+	def __init__(self):
+		self.status = None
+		self.name = ''
+		self.log = []
+
+	def __str__(self):
+		return 'TestCase(' + self.status + ',' + self.name + ',' + str(self.log) + ')'
+
+	def __repr__(self):
+		return str(self)
+
+class TestStatus(Enum):
+	SUCCESS = auto()
+	FAILURE = auto()
+	TEST_CRASHED = auto()
+	NO_TESTS = auto()
+
+kunit_start_re = re.compile(r'^TAP version [0-9]+$')
+kunit_end_re = re.compile('List of all partitions:')
+
+def isolate_kunit_output(kernel_output):
+	started = False
+	for line in kernel_output:
+		if kunit_start_re.match(line):
+			started = True
+			yield line
+		elif kunit_end_re.match(line):
+			break
+		elif started:
+			yield line
+
+def raw_output(kernel_output):
+	for line in kernel_output:
+		print(line)
+
+DIVIDER = '=' * 60
+
+RESET = '\033[0;0m'
+
+def red(text):
+	return '\033[1;31m' + text + RESET
+
+def yellow(text):
+	return '\033[1;33m' + text + RESET
+
+def green(text):
+	return '\033[1;32m' + text + RESET
+
+def print_with_timestamp(message):
+	print('[%s] %s' % (datetime.now().strftime('%H:%M:%S'), message))
+
+def format_suite_divider(message):
+	return '======== ' + message + ' ========'
+
+def print_suite_divider(message):
+	print_with_timestamp(DIVIDER)
+	print_with_timestamp(format_suite_divider(message))
+
+def print_log(log):
+	for m in log:
+		print_with_timestamp(m)
+
+TAP_ENTRIES = re.compile(r'^(TAP|\t?ok|\t?not ok|\t?[0-9]+\.\.[0-9]+|\t?#).*$')
+
+def consume_non_diagnositic(lines: List[str]) -> None:
+	while not TAP_ENTRIES.match(lines[0]):
+		lines.pop(0)
+
+def save_non_diagnositic(lines: List[str], test_case: TestCase) -> None:
+	while not TAP_ENTRIES.match(lines[0]):
+		test_case.log.append(lines[0])
+		lines.pop(0)
+
+OkNotOkResult = namedtuple('OkNotOkResult', ['is_ok','description', 'text'])
+
+OK_NOT_OK_SUBTEST = re.compile(r'^\t(ok|not ok) [0-9]+ - (.*)$')
+
+OK_NOT_OK_MODULE = re.compile(r'^(ok|not ok) [0-9]+ - (.*)$')
+
+def parse_ok_not_ok_test_case(lines: List[str], test_case: TestCase) -> bool:
+	save_non_diagnositic(lines, test_case)
+	line = lines[0]
+	match = OK_NOT_OK_SUBTEST.match(line)
+	if match:
+		test_case.log.append(lines.pop(0))
+		test_case.name = match.group(2)
+		if test_case.status == TestStatus.TEST_CRASHED:
+			return True
+		if match.group(1) == 'ok':
+			test_case.status = TestStatus.SUCCESS
+		else:
+			test_case.status = TestStatus.FAILURE
+		return True
+	else:
+		return False
+
+SUBTEST_DIAGNOSTIC = re.compile(r'^\t# .*?: (.*)$')
+DIAGNOSTIC_CRASH_MESSAGE = 'kunit test case crashed!'
+
+def parse_diagnostic(lines: List[str], test_case: TestCase) -> bool:
+	save_non_diagnositic(lines, test_case)
+	line = lines[0]
+	match = SUBTEST_DIAGNOSTIC.match(line)
+	if match:
+		test_case.log.append(lines.pop(0))
+		if match.group(1) == DIAGNOSTIC_CRASH_MESSAGE:
+			test_case.status = TestStatus.TEST_CRASHED
+		return True
+	else:
+		return False
+
+def parse_test_case(lines: List[str]) -> TestCase:
+	test_case = TestCase()
+	save_non_diagnositic(lines, test_case)
+	while parse_diagnostic(lines, test_case):
+		pass
+	if parse_ok_not_ok_test_case(lines, test_case):
+		return test_case
+	else:
+		return None
+
+SUBTEST_HEADER = re.compile(r'^\t# Subtest: (.*)$')
+
+def parse_subtest_header(lines: List[str]) -> str:
+	consume_non_diagnositic(lines)
+	match = SUBTEST_HEADER.match(lines[0])
+	if match:
+		lines.pop(0)
+		return match.group(1)
+	else:
+		return None
+
+SUBTEST_PLAN = re.compile(r'\t[0-9]+\.\.([0-9]+)')
+
+def parse_subtest_plan(lines: List[str]) -> int:
+	consume_non_diagnositic(lines)
+	match = SUBTEST_PLAN.match(lines[0])
+	if match:
+		lines.pop(0)
+		return match.group(1)
+	else:
+		return None
+
+def max_status(left: TestStatus, right: TestStatus) -> TestStatus:
+	if left == TestStatus.TEST_CRASHED or right == TestStatus.TEST_CRASHED:
+		return TestStatus.TEST_CRASHED
+	elif left == TestStatus.FAILURE or right == TestStatus.FAILURE:
+		return TestStatus.FAILURE
+	elif left != TestStatus.SUCCESS:
+		return left
+	elif right != TestStatus.SUCCESS:
+		return right
+	else:
+		return TestStatus.SUCCESS
+
+def parse_ok_not_ok_test_suite(lines: List[str], test_suite: TestSuite) -> bool:
+	consume_non_diagnositic(lines)
+	line = lines[0]
+	match = OK_NOT_OK_MODULE.match(line)
+	if match:
+		lines.pop(0)
+		if match.group(1) == 'ok':
+			test_suite.status = TestStatus.SUCCESS
+		else:
+			test_suite.status = TestStatus.FAILURE
+		return True
+	else:
+		return False
+
+def bubble_up_errors(to_status, status_container_list) -> TestStatus:
+	status_list = map(to_status, status_container_list)
+	return reduce(max_status, status_list, TestStatus.SUCCESS)
+
+def bubble_up_test_case_errors(test_suite: TestSuite) -> TestStatus:
+	max_test_case_status = bubble_up_errors(lambda x: x.status, test_suite.cases)
+	return max_status(max_test_case_status, test_suite.status)
+
+def parse_test_suite(lines: List[str]) -> TestSuite:
+	if not lines:
+		return None
+	consume_non_diagnositic(lines)
+	test_suite = TestSuite()
+	test_suite.status = TestStatus.SUCCESS
+	name = parse_subtest_header(lines)
+	if not name:
+		return None
+	test_suite.name = name
+	test_case_num = parse_subtest_plan(lines)
+	if not test_case_num:
+		return None
+	test_case = parse_test_case(lines)
+	while test_case:
+		test_suite.cases.append(test_case)
+		test_case = parse_test_case(lines)
+	if parse_ok_not_ok_test_suite(lines, test_suite):
+		test_suite.status = bubble_up_test_case_errors(test_suite)
+		return test_suite
+	else:
+		print('failed to parse end of suite' + lines[0])
+		return None
+
+TAP_HEADER = re.compile(r'^TAP version 14$')
+
+def parse_tap_header(lines: List[str]) -> bool:
+	consume_non_diagnositic(lines)
+	if TAP_HEADER.match(lines[0]):
+		lines.pop(0)
+		return True
+	else:
+		return False
+
+def bubble_up_suite_errors(test_suite_list: List[TestSuite]) -> TestStatus:
+	return bubble_up_errors(lambda x: x.status, test_suite_list)
+
+def parse_test_result(lines: List[str]) -> TestResult:
+	if not lines:
+		return TestResult(TestStatus.NO_TESTS, [], lines)
+	consume_non_diagnositic(lines)
+	if not parse_tap_header(lines):
+		return None
+	test_suites = []
+	test_suite = parse_test_suite(lines)
+	while test_suite:
+		test_suites.append(test_suite)
+		test_suite = parse_test_suite(lines)
+	return TestResult(bubble_up_suite_errors(test_suites), test_suites, lines)
+
+def parse_run_tests(kernel_output) -> TestResult:
+	total_tests = 0
+	failed_tests = 0
+	crashed_tests = 0
+	test_result = parse_test_result(list(isolate_kunit_output(kernel_output)))
+	for test_suite in test_result.suites:
+		if test_suite.status == TestStatus.SUCCESS:
+			print_suite_divider(green('[PASSED] ') + test_suite.name)
+		elif test_suite.status == TestStatus.TEST_CRASHED:
+			print_suite_divider(red('[CRASHED] ' + test_suite.name))
+		else:
+			print_suite_divider(red('[FAILED] ') + test_suite.name)
+		for test_case in test_suite.cases:
+			total_tests += 1
+			if test_case.status == TestStatus.SUCCESS:
+				print_with_timestamp(green('[PASSED] ') + test_case.name)
+			elif test_case.status == TestStatus.TEST_CRASHED:
+				crashed_tests += 1
+				print_with_timestamp(red('[CRASHED] ' + test_case.name))
+				print_log(map(yellow, test_case.log))
+				print_with_timestamp('')
+			else:
+				failed_tests += 1
+				print_with_timestamp(red('[FAILED] ') + test_case.name)
+				print_log(map(yellow, test_case.log))
+				print_with_timestamp('')
+	print_with_timestamp(DIVIDER)
+	fmt = green if test_result.status == TestStatus.SUCCESS else red
+	print_with_timestamp(
+		fmt('Testing complete. %d tests run. %d failed. %d crashed.' %
+		    (total_tests, failed_tests, crashed_tests)))
+	return test_result
diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
new file mode 100755
index 0000000000000..4a12baa0cd4e0
--- /dev/null
+++ b/tools/testing/kunit/kunit_tool_test.py
@@ -0,0 +1,206 @@
+#!/usr/bin/python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# A collection of tests for tools/testing/kunit/kunit.py
+#
+# Copyright (C) 2019, Google LLC.
+# Author: Brendan Higgins <brendanhiggins@google.com>
+
+import unittest
+from unittest import mock
+
+import tempfile, shutil # Handling test_tmpdir
+
+import os
+
+import kunit_config
+import kunit_parser
+import kunit_kernel
+import kunit
+
+test_tmpdir = ''
+
+def setUpModule():
+	global test_tmpdir
+	test_tmpdir = tempfile.mkdtemp()
+
+def tearDownModule():
+	shutil.rmtree(test_tmpdir)
+
+def get_absolute_path(path):
+	return os.path.join(os.path.dirname(__file__), path)
+
+class KconfigTest(unittest.TestCase):
+
+	def test_is_subset_of(self):
+		kconfig0 = kunit_config.Kconfig()
+		self.assertTrue(kconfig0.is_subset_of(kconfig0))
+
+		kconfig1 = kunit_config.Kconfig()
+		kconfig1.add_entry(kunit_config.KconfigEntry('CONFIG_TEST=y'))
+		self.assertTrue(kconfig1.is_subset_of(kconfig1))
+		self.assertTrue(kconfig0.is_subset_of(kconfig1))
+		self.assertFalse(kconfig1.is_subset_of(kconfig0))
+
+	def test_read_from_file(self):
+		kconfig = kunit_config.Kconfig()
+		kconfig_path = get_absolute_path(
+			'test_data/test_read_from_file.kconfig')
+
+		kconfig.read_from_file(kconfig_path)
+
+		expected_kconfig = kunit_config.Kconfig()
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_UML=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_MMU=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_TEST=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_EXAMPLE_TEST=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('# CONFIG_MK8 is not set'))
+
+		self.assertEqual(kconfig.entries(), expected_kconfig.entries())
+
+	def test_write_to_file(self):
+		kconfig_path = os.path.join(test_tmpdir, '.config')
+
+		expected_kconfig = kunit_config.Kconfig()
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_UML=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_MMU=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_TEST=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('CONFIG_EXAMPLE_TEST=y'))
+		expected_kconfig.add_entry(
+			kunit_config.KconfigEntry('# CONFIG_MK8 is not set'))
+
+		expected_kconfig.write_to_file(kconfig_path)
+
+		actual_kconfig = kunit_config.Kconfig()
+		actual_kconfig.read_from_file(kconfig_path)
+
+		self.assertEqual(actual_kconfig.entries(),
+				 expected_kconfig.entries())
+
+class KUnitParserTest(unittest.TestCase):
+
+	def assertContains(self, needle, haystack):
+		for line in haystack:
+			if needle in line:
+				return
+		raise AssertionError('"' +
+			str(needle) + '" not found in "' + str(haystack) + '"!')
+
+	def test_output_isolated_correctly(self):
+		log_path = get_absolute_path(
+			'test_data/test_output_isolated_correctly.log')
+		file = open(log_path)
+		result = kunit_parser.isolate_kunit_output(file.readlines())
+		self.assertContains('TAP version 14\n', result)
+		self.assertContains('	# Subtest: example', result)
+		self.assertContains('	1..2', result)
+		self.assertContains('	ok 1 - example_simple_test', result)
+		self.assertContains('	ok 2 - example_mock_test', result)
+		self.assertContains('ok 1 - example', result)
+		file.close()
+
+	def test_parse_successful_test_log(self):
+		all_passed_log = get_absolute_path(
+			'test_data/test_is_test_passed-all_passed.log')
+		file = open(all_passed_log)
+		result = kunit_parser.parse_run_tests(file.readlines())
+		self.assertEqual(
+			kunit_parser.TestStatus.SUCCESS,
+			result.status)
+		file.close()
+
+	def test_parse_failed_test_log(self):
+		failed_log = get_absolute_path(
+			'test_data/test_is_test_passed-failure.log')
+		file = open(failed_log)
+		result = kunit_parser.parse_run_tests(file.readlines())
+		self.assertEqual(
+			kunit_parser.TestStatus.FAILURE,
+			result.status)
+		file.close()
+
+	def test_no_tests(self):
+		empty_log = get_absolute_path(
+			'test_data/test_is_test_passed-no_tests_run.log')
+		file = open(empty_log)
+		result = kunit_parser.parse_run_tests(
+			kunit_parser.isolate_kunit_output(file.readlines()))
+		self.assertEqual(0, len(result.suites))
+		self.assertEqual(
+			kunit_parser.TestStatus.NO_TESTS,
+			result.status)
+		file.close()
+
+	def test_crashed_test(self):
+		crashed_log = get_absolute_path(
+			'test_data/test_is_test_passed-crash.log')
+		file = open(crashed_log)
+		result = kunit_parser.parse_run_tests(file.readlines())
+		self.assertEqual(
+			kunit_parser.TestStatus.TEST_CRASHED,
+			result.status)
+		file.close()
+
+class StrContains(str):
+	def __eq__(self, other):
+		return self in other
+
+class KUnitMainTest(unittest.TestCase):
+	def setUp(self):
+		path = get_absolute_path('test_data/test_is_test_passed-all_passed.log')
+		file = open(path)
+		all_passed_log = file.readlines()
+		self.print_patch = mock.patch('builtins.print')
+		self.print_mock = self.print_patch.start()
+		self.linux_source_mock = mock.Mock()
+		self.linux_source_mock.build_reconfig = mock.Mock(return_value=True)
+		self.linux_source_mock.build_um_kernel = mock.Mock(return_value=True)
+		self.linux_source_mock.run_kernel = mock.Mock(return_value=all_passed_log)
+
+	def tearDown(self):
+		self.print_patch.stop()
+		pass
+
+	def test_run_passes_args_pass(self):
+		kunit.main(['run'], self.linux_source_mock)
+		assert self.linux_source_mock.build_reconfig.call_count == 1
+		assert self.linux_source_mock.run_kernel.call_count == 1
+		self.print_mock.assert_any_call(StrContains('Testing complete.'))
+
+	def test_run_passes_args_fail(self):
+		self.linux_source_mock.run_kernel = mock.Mock(return_value=[])
+		with self.assertRaises(SystemExit) as e:
+			kunit.main(['run'], self.linux_source_mock)
+		assert type(e.exception) == SystemExit
+		assert e.exception.code == 1
+		assert self.linux_source_mock.build_reconfig.call_count == 1
+		assert self.linux_source_mock.run_kernel.call_count == 1
+		self.print_mock.assert_any_call(StrContains(' 0 tests run'))
+
+	def test_run_raw_output(self):
+		self.linux_source_mock.run_kernel = mock.Mock(return_value=[])
+		kunit.main(['run', '--raw_output'], self.linux_source_mock)
+		assert self.linux_source_mock.build_reconfig.call_count == 1
+		assert self.linux_source_mock.run_kernel.call_count == 1
+		for kall in self.print_mock.call_args_list:
+			assert kall != mock.call(StrContains('Testing complete.'))
+			assert kall != mock.call(StrContains(' 0 tests run'))
+
+	def test_run_timeout(self):
+		timeout = 3453
+		kunit.main(['run', '--timeout', str(timeout)], self.linux_source_mock)
+		assert self.linux_source_mock.build_reconfig.call_count == 1
+		self.linux_source_mock.run_kernel.assert_called_once_with(timeout=timeout)
+		self.print_mock.assert_any_call(StrContains('Testing complete.'))
+
+if __name__ == '__main__':
+	unittest.main()
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-all_passed.log b/tools/testing/kunit/test_data/test_is_test_passed-all_passed.log
new file mode 100644
index 0000000000000..62ebc0288355c
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_is_test_passed-all_passed.log
@@ -0,0 +1,32 @@
+TAP version 14
+	# Subtest: sysctl_test
+	1..8
+	# sysctl_test_dointvec_null_tbl_data: sysctl_test_dointvec_null_tbl_data passed
+	ok 1 - sysctl_test_dointvec_null_tbl_data
+	# sysctl_test_dointvec_table_maxlen_unset: sysctl_test_dointvec_table_maxlen_unset passed
+	ok 2 - sysctl_test_dointvec_table_maxlen_unset
+	# sysctl_test_dointvec_table_len_is_zero: sysctl_test_dointvec_table_len_is_zero passed
+	ok 3 - sysctl_test_dointvec_table_len_is_zero
+	# sysctl_test_dointvec_table_read_but_position_set: sysctl_test_dointvec_table_read_but_position_set passed
+	ok 4 - sysctl_test_dointvec_table_read_but_position_set
+	# sysctl_test_dointvec_happy_single_positive: sysctl_test_dointvec_happy_single_positive passed
+	ok 5 - sysctl_test_dointvec_happy_single_positive
+	# sysctl_test_dointvec_happy_single_negative: sysctl_test_dointvec_happy_single_negative passed
+	ok 6 - sysctl_test_dointvec_happy_single_negative
+	# sysctl_test_dointvec_single_less_int_min: sysctl_test_dointvec_single_less_int_min passed
+	ok 7 - sysctl_test_dointvec_single_less_int_min
+	# sysctl_test_dointvec_single_greater_int_max: sysctl_test_dointvec_single_greater_int_max passed
+	ok 8 - sysctl_test_dointvec_single_greater_int_max
+kunit sysctl_test: all tests passed
+ok 1 - sysctl_test
+	# Subtest: example
+	1..2
+init_suite
+	# example_simple_test: initializing
+	# example_simple_test: example_simple_test passed
+	ok 1 - example_simple_test
+	# example_mock_test: initializing
+	# example_mock_test: example_mock_test passed
+	ok 2 - example_mock_test
+kunit example: all tests passed
+ok 2 - example
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-crash.log b/tools/testing/kunit/test_data/test_is_test_passed-crash.log
new file mode 100644
index 0000000000000..0b249870c8be4
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_is_test_passed-crash.log
@@ -0,0 +1,69 @@
+printk: console [tty0] enabled
+printk: console [mc-1] enabled
+TAP version 14
+	# Subtest: sysctl_test
+	1..8
+	# sysctl_test_dointvec_null_tbl_data: sysctl_test_dointvec_null_tbl_data passed
+	ok 1 - sysctl_test_dointvec_null_tbl_data
+	# sysctl_test_dointvec_table_maxlen_unset: sysctl_test_dointvec_table_maxlen_unset passed
+	ok 2 - sysctl_test_dointvec_table_maxlen_unset
+	# sysctl_test_dointvec_table_len_is_zero: sysctl_test_dointvec_table_len_is_zero passed
+	ok 3 - sysctl_test_dointvec_table_len_is_zero
+	# sysctl_test_dointvec_table_read_but_position_set: sysctl_test_dointvec_table_read_but_position_set passed
+	ok 4 - sysctl_test_dointvec_table_read_but_position_set
+	# sysctl_test_dointvec_happy_single_positive: sysctl_test_dointvec_happy_single_positive passed
+	ok 5 - sysctl_test_dointvec_happy_single_positive
+	# sysctl_test_dointvec_happy_single_negative: sysctl_test_dointvec_happy_single_negative passed
+	ok 6 - sysctl_test_dointvec_happy_single_negative
+	# sysctl_test_dointvec_single_less_int_min: sysctl_test_dointvec_single_less_int_min passed
+	ok 7 - sysctl_test_dointvec_single_less_int_min
+	# sysctl_test_dointvec_single_greater_int_max: sysctl_test_dointvec_single_greater_int_max passed
+	ok 8 - sysctl_test_dointvec_single_greater_int_max
+kunit sysctl_test: all tests passed
+ok 1 - sysctl_test
+	# Subtest: example
+	1..2
+init_suite
+	# example_simple_test: initializing
+Stack:
+ 6016f7db 6f81bd30 6f81bdd0 60021450
+ 6024b0e8 60021440 60018bbe 16f81bdc0
+ 00000001 6f81bd30 6f81bd20 6f81bdd0
+Call Trace:
+ [<6016f7db>] ? kunit_try_run_case+0xab/0xf0
+ [<60021450>] ? set_signals+0x0/0x60
+ [<60021440>] ? get_signals+0x0/0x10
+ [<60018bbe>] ? kunit_um_run_try_catch+0x5e/0xc0
+ [<60021450>] ? set_signals+0x0/0x60
+ [<60021440>] ? get_signals+0x0/0x10
+ [<60018bb3>] ? kunit_um_run_try_catch+0x53/0xc0
+ [<6016f321>] ? kunit_run_case_catch_errors+0x121/0x1a0
+ [<60018b60>] ? kunit_um_run_try_catch+0x0/0xc0
+ [<600189e0>] ? kunit_um_throw+0x0/0x180
+ [<6016f730>] ? kunit_try_run_case+0x0/0xf0
+ [<6016f600>] ? kunit_catch_run_case+0x0/0x130
+ [<6016edd0>] ? kunit_vprintk+0x0/0x30
+ [<6016ece0>] ? kunit_fail+0x0/0x40
+ [<6016eca0>] ? kunit_abort+0x0/0x40
+ [<6016ed20>] ? kunit_printk_emit+0x0/0xb0
+ [<6016f200>] ? kunit_run_case_catch_errors+0x0/0x1a0
+ [<6016f46e>] ? kunit_run_tests+0xce/0x260
+ [<6005b390>] ? unregister_console+0x0/0x190
+ [<60175b70>] ? suite_kunit_initexample_test_suite+0x0/0x20
+ [<60001cbb>] ? do_one_initcall+0x0/0x197
+ [<60001d47>] ? do_one_initcall+0x8c/0x197
+ [<6005cd20>] ? irq_to_desc+0x0/0x30
+ [<60002005>] ? kernel_init_freeable+0x1b3/0x272
+ [<6005c5ec>] ? printk+0x0/0x9b
+ [<601c0086>] ? kernel_init+0x26/0x160
+ [<60014442>] ? new_thread_handler+0x82/0xc0
+
+	# example_simple_test: kunit test case crashed!
+	# example_simple_test: example_simple_test failed
+	not ok 1 - example_simple_test
+	# example_mock_test: initializing
+	# example_mock_test: example_mock_test passed
+	ok 2 - example_mock_test
+kunit example: one or more tests failed
+not ok 2 - example
+List of all partitions:
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-failure.log b/tools/testing/kunit/test_data/test_is_test_passed-failure.log
new file mode 100644
index 0000000000000..2ed870b6de72f
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_is_test_passed-failure.log
@@ -0,0 +1,36 @@
+TAP version 14
+	# Subtest: sysctl_test
+	1..8
+	# sysctl_test_dointvec_null_tbl_data: sysctl_test_dointvec_null_tbl_data passed
+	ok 1 - sysctl_test_dointvec_null_tbl_data
+	# sysctl_test_dointvec_table_maxlen_unset: sysctl_test_dointvec_table_maxlen_unset passed
+	ok 2 - sysctl_test_dointvec_table_maxlen_unset
+	# sysctl_test_dointvec_table_len_is_zero: sysctl_test_dointvec_table_len_is_zero passed
+	ok 3 - sysctl_test_dointvec_table_len_is_zero
+	# sysctl_test_dointvec_table_read_but_position_set: sysctl_test_dointvec_table_read_but_position_set passed
+	ok 4 - sysctl_test_dointvec_table_read_but_position_set
+	# sysctl_test_dointvec_happy_single_positive: sysctl_test_dointvec_happy_single_positive passed
+	ok 5 - sysctl_test_dointvec_happy_single_positive
+	# sysctl_test_dointvec_happy_single_negative: sysctl_test_dointvec_happy_single_negative passed
+	ok 6 - sysctl_test_dointvec_happy_single_negative
+	# sysctl_test_dointvec_single_less_int_min: sysctl_test_dointvec_single_less_int_min passed
+	ok 7 - sysctl_test_dointvec_single_less_int_min
+	# sysctl_test_dointvec_single_greater_int_max: sysctl_test_dointvec_single_greater_int_max passed
+	ok 8 - sysctl_test_dointvec_single_greater_int_max
+kunit sysctl_test: all tests passed
+ok 1 - sysctl_test
+	# Subtest: example
+	1..2
+init_suite
+	# example_simple_test: initializing
+	# example_simple_test: EXPECTATION FAILED at kunit/example-test.c:30
+	Expected 1 + 1 == 3, but
+		1 + 1 == 2
+		3 == 3
+	# example_simple_test: example_simple_test failed
+	not ok 1 - example_simple_test
+	# example_mock_test: initializing
+	# example_mock_test: example_mock_test passed
+	ok 2 - example_mock_test
+kunit example: one or more tests failed
+not ok 2 - example
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log
new file mode 100644
index 0000000000000..ba69f5c94b75f
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log
@@ -0,0 +1,75 @@
+Core dump limits :
+	soft - 0
+	hard - NONE
+Checking environment variables for a tempdir...none found
+Checking if /dev/shm is on tmpfs...OK
+Checking PROT_EXEC mmap in /dev/shm...OK
+Adding 24743936 bytes to physical memory to account for exec-shield gap
+Linux version 4.12.0-rc3-00010-g7319eb35f493-dirty (brendanhiggins@mactruck.svl.corp.google.com) (gcc version 7.3.0 (Debian 7.3.0-5) ) #29 Thu Mar 15 14:57:19 PDT 2018
+Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 14038
+Kernel command line: root=98:0
+PID hash table entries: 256 (order: -1, 2048 bytes)
+Dentry cache hash table entries: 8192 (order: 4, 65536 bytes)
+Inode-cache hash table entries: 4096 (order: 3, 32768 bytes)
+Memory: 27868K/56932K available (1681K kernel code, 480K rwdata, 400K rodata, 89K init, 205K bss, 29064K reserved, 0K cma-reserved)
+SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
+NR_IRQS:15
+clocksource: timer: mask: 0xffffffffffffffff max_cycles: 0x1cd42e205, max_idle_ns: 881590404426 ns
+Calibrating delay loop... 7384.26 BogoMIPS (lpj=36921344)
+pid_max: default: 32768 minimum: 301
+Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
+Mountpoint-cache hash table entries: 512 (order: 0, 4096 bytes)
+Checking that host ptys support output SIGIO...Yes
+Checking that host ptys support SIGIO on close...No, enabling workaround
+Using 2.6 host AIO
+clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
+futex hash table entries: 256 (order: 0, 6144 bytes)
+clocksource: Switched to clocksource timer
+console [stderr0] disabled
+mconsole (version 2) initialized on /usr/local/google/home/brendanhiggins/.uml/6Ijecl/mconsole
+Checking host MADV_REMOVE support...OK
+workingset: timestamp_bits=62 max_order=13 bucket_order=0
+Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
+io scheduler noop registered
+io scheduler deadline registered
+io scheduler cfq registered (default)
+io scheduler mq-deadline registered
+io scheduler kyber registered
+Initialized stdio console driver
+Using a channel type which is configured out of UML
+setup_one_line failed for device 1 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 2 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 3 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 4 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 5 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 6 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 7 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 8 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 9 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 10 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 11 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 12 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 13 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 14 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 15 : Configuration failed
+Console initialized on /dev/tty0
+console [tty0] enabled
+console [mc-1] enabled
+List of all partitions:
+No filesystem could mount root, tried:
+
+Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(98,0)
diff --git a/tools/testing/kunit/test_data/test_output_isolated_correctly.log b/tools/testing/kunit/test_data/test_output_isolated_correctly.log
new file mode 100644
index 0000000000000..94a6b3aeaa922
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_output_isolated_correctly.log
@@ -0,0 +1,106 @@
+Linux version 5.1.0-rc7-00061-g04652f1cb4aa0 (brendanhiggins@mactruck.svl.corp.google.com) (gcc version 7.3.0 (Debian 7.3.0-18)) #163 Wed May 8 16:18:20 PDT 2019
+Built 1 zonelists, mobility grouping on.  Total pages: 69906
+Kernel command line: mem=256M root=98:0
+Dentry cache hash table entries: 65536 (order: 7, 524288 bytes)
+Inode-cache hash table entries: 32768 (order: 6, 262144 bytes)
+Memory: 254468K/283500K available (1734K kernel code, 489K rwdata, 396K rodata, 85K init, 216K bss, 29032K reserved, 0K cma-reserved)
+SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
+NR_IRQS: 15
+clocksource: timer: mask: 0xffffffffffffffff max_cycles: 0x1cd42e205, max_idle_ns: 881590404426 ns
+------------[ cut here ]------------
+WARNING: CPU: 0 PID: 0 at kernel/time/clockevents.c:458 clockevents_register_device+0x143/0x160
+posix-timer cpumask == cpu_all_mask, using cpu_possible_mask instead
+CPU: 0 PID: 0 Comm: swapper Not tainted 5.1.0-rc7-00061-g04652f1cb4aa0 #163
+Stack:
+ 6005cc00 60233e18 60233e60 60233e18
+ 60233e60 00000009 00000000 6002a1b4
+ 1ca00000000 60071c23 60233e78 100000000000062
+Call Trace:
+ [<600214c5>] ? os_is_signal_stack+0x15/0x30
+ [<6005c5ec>] ? printk+0x0/0x9b
+ [<6001597e>] ? show_stack+0xbe/0x1c0
+ [<6005cc00>] ? __printk_safe_exit+0x0/0x40
+ [<6002a1b4>] ? __warn+0x144/0x170
+ [<60071c23>] ? clockevents_register_device+0x143/0x160
+ [<60021440>] ? get_signals+0x0/0x10
+ [<6005c5ec>] ? printk+0x0/0x9b
+ [<6002a27b>] ? warn_slowpath_fmt+0x9b/0xb0
+ [<6005c5ec>] ? printk+0x0/0x9b
+ [<6002a1e0>] ? warn_slowpath_fmt+0x0/0xb0
+ [<6005c5ec>] ? printk+0x0/0x9b
+ [<60021440>] ? get_signals+0x0/0x10
+ [<600213f0>] ? block_signals+0x0/0x20
+ [<60071c23>] ? clockevents_register_device+0x143/0x160
+ [<60021440>] ? get_signals+0x0/0x10
+ [<600213f0>] ? block_signals+0x0/0x20
+ [<6005c5ec>] ? printk+0x0/0x9b
+ [<60001bc8>] ? start_kernel+0x477/0x56a
+ [<600036f1>] ? start_kernel_proc+0x46/0x4d
+ [<60014442>] ? new_thread_handler+0x82/0xc0
+
+random: get_random_bytes called from print_oops_end_marker+0x4c/0x60 with crng_init=0
+---[ end trace c83434852b3702d3 ]---
+Calibrating delay loop... 6958.28 BogoMIPS (lpj=34791424)
+pid_max: default: 32768 minimum: 301
+Mount-cache hash table entries: 1024 (order: 1, 8192 bytes)
+Mountpoint-cache hash table entries: 1024 (order: 1, 8192 bytes)
+*** VALIDATE proc ***
+Checking that host ptys support output SIGIO...Yes
+Checking that host ptys support SIGIO on close...No, enabling workaround
+clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns
+futex hash table entries: 256 (order: 0, 6144 bytes)
+clocksource: Switched to clocksource timer
+printk: console [stderr0] disabled
+mconsole (version 2) initialized on /usr/local/google/home/brendanhiggins/.uml/VZ2qMm/mconsole
+Checking host MADV_REMOVE support...OK
+workingset: timestamp_bits=62 max_order=16 bucket_order=0
+Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
+io scheduler mq-deadline registered
+io scheduler kyber registered
+Initialized stdio console driver
+Using a channel type which is configured out of UML
+setup_one_line failed for device 1 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 2 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 3 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 4 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 5 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 6 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 7 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 8 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 9 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 10 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 11 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 12 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 13 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 14 : Configuration failed
+Using a channel type which is configured out of UML
+setup_one_line failed for device 15 : Configuration failed
+Console initialized on /dev/tty0
+printk: console [tty0] enabled
+printk: console [mc-1] enabled
+TAP version 14
+	# Subtest: example
+	1..2
+init_suite
+	# example_simple_test: initializing
+	# example_simple_test: example_simple_test passed
+	ok 1 - example_simple_test
+	# example_mock_test: initializing
+	# example_mock_test: example_mock_test passed
+	ok 2 - example_mock_test
+kunit example: all tests passed
+ok 1 - example
+List of all partitions:
diff --git a/tools/testing/kunit/test_data/test_read_from_file.kconfig b/tools/testing/kunit/test_data/test_read_from_file.kconfig
new file mode 100644
index 0000000000000..d2a4928ac773b
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_read_from_file.kconfig
@@ -0,0 +1,17 @@
+#
+# Automatically generated file; DO NOT EDIT.
+# User Mode Linux/x86 4.12.0-rc3 Kernel Configuration
+#
+CONFIG_UML=y
+CONFIG_MMU=y
+
+#
+# UML-specific options
+#
+
+#
+# Host processor type and features
+#
+# CONFIG_MK8 is not set
+CONFIG_TEST=y
+CONFIG_EXAMPLE_TEST=y
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 14/18] kunit: defconfig: add defconfigs for building KUnit tests
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (12 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 13/18] kunit: tool: add Python wrappers for running KUnit tests Brendan Higgins
@ 2019-07-12  8:17 ` " Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 15/18] Documentation: kunit: add documentation for KUnit Brendan Higgins
                   ` (3 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add defconfig for UML and a fragment that can be used to configure other
architectures for building KUnit tests. Add option to kunit_tool to use
a defconfig to create the kunitconfig.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 arch/um/configs/kunit_defconfig              |  8 ++++++++
 tools/testing/kunit/configs/all_tests.config |  8 ++++++++
 tools/testing/kunit/kunit.py                 | 18 ++++++++++++++++--
 tools/testing/kunit/kunit_kernel.py          |  3 ++-
 4 files changed, 34 insertions(+), 3 deletions(-)
 create mode 100644 arch/um/configs/kunit_defconfig
 create mode 100644 tools/testing/kunit/configs/all_tests.config

diff --git a/arch/um/configs/kunit_defconfig b/arch/um/configs/kunit_defconfig
new file mode 100644
index 0000000000000..bfe49689038f1
--- /dev/null
+++ b/arch/um/configs/kunit_defconfig
@@ -0,0 +1,8 @@
+CONFIG_OF=y
+CONFIG_OF_UNITTEST=y
+CONFIG_OF_OVERLAY=y
+CONFIG_I2C=y
+CONFIG_I2C_MUX=y
+CONFIG_KUNIT=y
+CONFIG_KUNIT_TEST=y
+CONFIG_KUNIT_EXAMPLE_TEST=y
diff --git a/tools/testing/kunit/configs/all_tests.config b/tools/testing/kunit/configs/all_tests.config
new file mode 100644
index 0000000000000..bfe49689038f1
--- /dev/null
+++ b/tools/testing/kunit/configs/all_tests.config
@@ -0,0 +1,8 @@
+CONFIG_OF=y
+CONFIG_OF_UNITTEST=y
+CONFIG_OF_OVERLAY=y
+CONFIG_I2C=y
+CONFIG_I2C_MUX=y
+CONFIG_KUNIT=y
+CONFIG_KUNIT_TEST=y
+CONFIG_KUNIT_EXAMPLE_TEST=y
diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
index da11bd62a4b82..3e51dc4febfdc 100755
--- a/tools/testing/kunit/kunit.py
+++ b/tools/testing/kunit/kunit.py
@@ -11,6 +11,7 @@ import argparse
 import sys
 import os
 import time
+import shutil
 
 from collections import namedtuple
 from enum import Enum, auto
@@ -21,7 +22,7 @@ import kunit_parser
 
 KunitResult = namedtuple('KunitResult', ['status','result'])
 
-KunitRequest = namedtuple('KunitRequest', ['raw_output','timeout', 'jobs', 'build_dir'])
+KunitRequest = namedtuple('KunitRequest', ['raw_output','timeout', 'jobs', 'build_dir', 'defconfig'])
 
 class KunitStatus(Enum):
 	SUCCESS = auto()
@@ -29,8 +30,16 @@ class KunitStatus(Enum):
 	BUILD_FAILURE = auto()
 	TEST_FAILURE = auto()
 
+def create_default_kunitconfig():
+	if not os.path.exists(kunit_kernel.KUNITCONFIG_PATH):
+		shutil.copyfile('arch/um/configs/kunit_defconfig',
+				kunit_kernel.KUNITCONFIG_PATH)
+
 def run_tests(linux: kunit_kernel.LinuxSourceTree,
 	      request: KunitRequest) -> KunitResult:
+	if request.defconfig:
+		create_default_kunitconfig()
+
 	config_start = time.time()
 	success = linux.build_reconfig(request.build_dir)
 	config_end = time.time()
@@ -99,13 +108,18 @@ def main(argv, linux):
 				'directory.',
 				type=str, default=None, metavar='build_dir')
 
+	run_parser.add_argument('--defconfig',
+				help='Uses a default kunitconfig.',
+				action='store_true')
+
 	cli_args = parser.parse_args(argv)
 
 	if cli_args.subcommand == 'run':
 		request = KunitRequest(cli_args.raw_output,
 				       cli_args.timeout,
 				       cli_args.jobs,
-				       cli_args.build_dir)
+				       cli_args.build_dir,
+				       cli_args.defconfig)
 		result = run_tests(linux, request)
 		if result.status != KunitStatus.SUCCESS:
 			sys.exit(1)
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index 07c0abf2f47df..bf38768353313 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -14,6 +14,7 @@ import os
 import kunit_config
 
 KCONFIG_PATH = '.config'
+KUNITCONFIG_PATH = 'kunitconfig'
 
 class ConfigError(Exception):
 	"""Represents an error trying to configure the Linux kernel."""
@@ -81,7 +82,7 @@ class LinuxSourceTree(object):
 
 	def __init__(self):
 		self._kconfig = kunit_config.Kconfig()
-		self._kconfig.read_from_file('kunitconfig')
+		self._kconfig.read_from_file(KUNITCONFIG_PATH)
 		self._ops = LinuxSourceTreeOperations()
 
 	def clean(self):
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 15/18] Documentation: kunit: add documentation for KUnit
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (13 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 14/18] kunit: defconfig: add defconfigs for building " Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 16/18] MAINTAINERS: add entry for KUnit the unit testing framework Brendan Higgins
                   ` (2 subsequent siblings)
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins, Felix Guo, Jonathan Corbet

Add documentation for KUnit, the Linux kernel unit testing framework.
- Add intro and usage guide for KUnit
- Add API reference

Signed-off-by: Felix Guo <felixguoxiuping@gmail.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 Documentation/dev-tools/index.rst           |   1 +
 Documentation/dev-tools/kunit/api/index.rst |  16 +
 Documentation/dev-tools/kunit/api/test.rst  |  14 +
 Documentation/dev-tools/kunit/faq.rst       |  62 +++
 Documentation/dev-tools/kunit/index.rst     |  79 +++
 Documentation/dev-tools/kunit/start.rst     | 180 ++++++
 Documentation/dev-tools/kunit/usage.rst     | 575 ++++++++++++++++++++
 7 files changed, 927 insertions(+)
 create mode 100644 Documentation/dev-tools/kunit/api/index.rst
 create mode 100644 Documentation/dev-tools/kunit/api/test.rst
 create mode 100644 Documentation/dev-tools/kunit/faq.rst
 create mode 100644 Documentation/dev-tools/kunit/index.rst
 create mode 100644 Documentation/dev-tools/kunit/start.rst
 create mode 100644 Documentation/dev-tools/kunit/usage.rst

diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst
index b0522a4dd1073..09dee10d25928 100644
--- a/Documentation/dev-tools/index.rst
+++ b/Documentation/dev-tools/index.rst
@@ -24,6 +24,7 @@ whole; patches welcome!
    gdb-kernel-debugging
    kgdb
    kselftest
+   kunit/index
 
 
 .. only::  subproject and html
diff --git a/Documentation/dev-tools/kunit/api/index.rst b/Documentation/dev-tools/kunit/api/index.rst
new file mode 100644
index 0000000000000..9b9bffe5d41a0
--- /dev/null
+++ b/Documentation/dev-tools/kunit/api/index.rst
@@ -0,0 +1,16 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============
+API Reference
+=============
+.. toctree::
+
+	test
+
+This section documents the KUnit kernel testing API. It is divided into the
+following sections:
+
+================================= ==============================================
+:doc:`test`                       documents all of the standard testing API
+                                  excluding mocking or mocking related features.
+================================= ==============================================
diff --git a/Documentation/dev-tools/kunit/api/test.rst b/Documentation/dev-tools/kunit/api/test.rst
new file mode 100644
index 0000000000000..d0ce19b1e1185
--- /dev/null
+++ b/Documentation/dev-tools/kunit/api/test.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+========
+Test API
+========
+
+This file documents all of the standard testing API excluding mocking or mocking
+related features.
+
+.. kernel-doc:: include/kunit/test.h
+   :internal:
+
+.. kernel-doc:: include/kunit/kunit-stream.h
+   :internal:
diff --git a/Documentation/dev-tools/kunit/faq.rst b/Documentation/dev-tools/kunit/faq.rst
new file mode 100644
index 0000000000000..bf2095112d899
--- /dev/null
+++ b/Documentation/dev-tools/kunit/faq.rst
@@ -0,0 +1,62 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+Frequently Asked Questions
+==========================
+
+How is this different from Autotest, kselftest, etc?
+====================================================
+KUnit is a unit testing framework. Autotest, kselftest (and some others) are
+not.
+
+A `unit test <https://martinfowler.com/bliki/UnitTest.html>`_ is supposed to
+test a single unit of code in isolation, hence the name. A unit test should be
+the finest granularity of testing and as such should allow all possible code
+paths to be tested in the code under test; this is only possible if the code
+under test is very small and does not have any external dependencies outside of
+the test's control like hardware.
+
+There are no testing frameworks currently available for the kernel that do not
+require installing the kernel on a test machine or in a VM and all require
+tests to be written in userspace and run on the kernel under test; this is true
+for Autotest, kselftest, and some others, disqualifying any of them from being
+considered unit testing frameworks.
+
+Does KUnit support running on architectures other than UML?
+===========================================================
+
+Yes, well, mostly.
+
+For the most part, the KUnit core framework (what you use to write the tests)
+can compile to any architecture; it compiles like just another part of the
+kernel and runs when the kernel boots. However, there is some infrastructure,
+like the KUnit Wrapper (``tools/testing/kunit/kunit.py``) that does not support
+other architectures.
+
+In short, this means that, yes, you can run KUnit on other architectures, but
+it might require more work than using KUnit on UML.
+
+For more information, see :ref:`kunit-on-non-uml`.
+
+What is the difference between a unit test and these other kinds of tests?
+==========================================================================
+Most existing tests for the Linux kernel would be categorized as an integration
+test, or an end-to-end test.
+
+- A unit test is supposed to test a single unit of code in isolation, hence the
+  name. A unit test should be the finest granularity of testing and as such
+  should allow all possible code paths to be tested in the code under test; this
+  is only possible if the code under test is very small and does not have any
+  external dependencies outside of the test's control like hardware.
+- An integration test tests the interaction between a minimal set of components,
+  usually just two or three. For example, someone might write an integration
+  test to test the interaction between a driver and a piece of hardware, or to
+  test the interaction between the userspace libraries the kernel provides and
+  the kernel itself; however, one of these tests would probably not test the
+  entire kernel along with hardware interactions and interactions with the
+  userspace.
+- An end-to-end test usually tests the entire system from the perspective of the
+  code under test. For example, someone might write an end-to-end test for the
+  kernel by installing a production configuration of the kernel on production
+  hardware with a production userspace and then trying to exercise some behavior
+  that depends on interactions between the hardware, the kernel, and userspace.
diff --git a/Documentation/dev-tools/kunit/index.rst b/Documentation/dev-tools/kunit/index.rst
new file mode 100644
index 0000000000000..a317ab45bfe2d
--- /dev/null
+++ b/Documentation/dev-tools/kunit/index.rst
@@ -0,0 +1,79 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================================
+KUnit - Unit Testing for the Linux Kernel
+=========================================
+
+.. toctree::
+	:maxdepth: 2
+
+	start
+	usage
+	api/index
+	faq
+
+What is KUnit?
+==============
+
+KUnit is a lightweight unit testing and mocking framework for the Linux kernel.
+These tests are able to be run locally on a developer's workstation without a VM
+or special hardware.
+
+KUnit is heavily inspired by JUnit, Python's unittest.mock, and
+Googletest/Googlemock for C++. KUnit provides facilities for defining unit test
+cases, grouping related test cases into test suites, providing common
+infrastructure for running tests, and much more.
+
+Get started now: :doc:`start`
+
+Why KUnit?
+==========
+
+A unit test is supposed to test a single unit of code in isolation, hence the
+name. A unit test should be the finest granularity of testing and as such should
+allow all possible code paths to be tested in the code under test; this is only
+possible if the code under test is very small and does not have any external
+dependencies outside of the test's control like hardware.
+
+Outside of KUnit, there are no testing frameworks currently
+available for the kernel that do not require installing the kernel on a test
+machine or in a VM and all require tests to be written in userspace running on
+the kernel; this is true for Autotest, and kselftest, disqualifying
+any of them from being considered unit testing frameworks.
+
+KUnit addresses the problem of being able to run tests without needing a virtual
+machine or actual hardware with User Mode Linux. User Mode Linux is a Linux
+architecture, like ARM or x86; however, unlike other architectures it compiles
+to a standalone program that can be run like any other program directly inside
+of a host operating system; to be clear, it does not require any virtualization
+support; it is just a regular program.
+
+KUnit is fast. Excluding build time, from invocation to completion KUnit can run
+several dozen tests in only 10 to 20 seconds; this might not sound like a big
+deal to some people, but having such fast and easy to run tests fundamentally
+changes the way you go about testing and even writing code in the first place.
+Linus himself said in his `git talk at Google
+<https://gist.github.com/lorn/1272686/revisions#diff-53c65572127855f1b003db4064a94573R874>`_:
+
+	"... a lot of people seem to think that performance is about doing the
+	same thing, just doing it faster, and that is not true. That is not what
+	performance is all about. If you can do something really fast, really
+	well, people will start using it differently."
+
+In this context Linus was talking about branching and merging,
+but this point also applies to testing. If your tests are slow, unreliable, are
+difficult to write, and require a special setup or special hardware to run,
+then you wait a lot longer to write tests, and you wait a lot longer to run
+tests; this means that tests are likely to break, unlikely to test a lot of
+things, and are unlikely to be rerun once they pass. If your tests are really
+fast, you run them all the time, every time you make a change, and every time
+someone sends you some code. Why trust that someone ran all their tests
+correctly on every change when you can just run them yourself in less time than
+it takes to read his / her test log?
+
+How do I use it?
+================
+
+*   :doc:`start` - for new users of KUnit
+*   :doc:`usage` - for a more detailed explanation of KUnit features
+*   :doc:`api/index` - for the list of KUnit APIs used for testing
diff --git a/Documentation/dev-tools/kunit/start.rst b/Documentation/dev-tools/kunit/start.rst
new file mode 100644
index 0000000000000..6dc229e46bb34
--- /dev/null
+++ b/Documentation/dev-tools/kunit/start.rst
@@ -0,0 +1,180 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============
+Getting Started
+===============
+
+Installing dependencies
+=======================
+KUnit has the same dependencies as the Linux kernel. As long as you can build
+the kernel, you can run KUnit.
+
+KUnit Wrapper
+=============
+Included with KUnit is a simple Python wrapper that helps format the output to
+easily use and read KUnit output. It handles building and running the kernel, as
+well as formatting the output.
+
+The wrapper can be run with:
+
+.. code-block:: bash
+
+   ./tools/testing/kunit/kunit.py run
+
+Creating a kunitconfig
+======================
+The Python script is a thin wrapper around Kbuild as such, it needs to be
+configured with a ``kunitconfig`` file. This file essentially contains the
+regular Kernel config, with the specific test targets as well.
+
+.. code-block:: bash
+
+	git clone -b master https://kunit.googlesource.com/kunitconfig $PATH_TO_KUNITCONFIG_REPO
+	cd $PATH_TO_LINUX_REPO
+	ln -s $PATH_TO_KUNIT_CONFIG_REPO/kunitconfig kunitconfig
+
+You may want to add kunitconfig to your local gitignore.
+
+Verifying KUnit Works
+---------------------
+
+To make sure that everything is set up correctly, simply invoke the Python
+wrapper from your kernel repo:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py
+
+.. note::
+   You may want to run ``make mrproper`` first.
+
+If everything worked correctly, you should see the following:
+
+.. code-block:: bash
+
+	Generating .config ...
+	Building KUnit Kernel ...
+	Starting KUnit Kernel ...
+
+followed by a list of tests that are run. All of them should be passing.
+
+.. note::
+   Because it is building a lot of sources for the first time, the ``Building
+   kunit kernel`` step may take a while.
+
+Writing your first test
+=======================
+
+In your kernel repo let's add some code that we can test. Create a file
+``drivers/misc/example.h`` with the contents:
+
+.. code-block:: c
+
+	int misc_example_add(int left, int right);
+
+create a file ``drivers/misc/example.c``:
+
+.. code-block:: c
+
+	#include <linux/errno.h>
+
+	#include "example.h"
+
+	int misc_example_add(int left, int right)
+	{
+		return left + right;
+	}
+
+Now add the following lines to ``drivers/misc/Kconfig``:
+
+.. code-block:: kconfig
+
+	config MISC_EXAMPLE
+		bool "My example"
+
+and the following lines to ``drivers/misc/Makefile``:
+
+.. code-block:: make
+
+	obj-$(CONFIG_MISC_EXAMPLE) += example.o
+
+Now we are ready to write the test. The test will be in
+``drivers/misc/example-test.c``:
+
+.. code-block:: c
+
+	#include <kunit/test.h>
+	#include "example.h"
+
+	/* Define the test cases. */
+
+	static void misc_example_add_test_basic(struct kunit *test)
+	{
+		KUNIT_EXPECT_EQ(test, 1, misc_example_add(1, 0));
+		KUNIT_EXPECT_EQ(test, 2, misc_example_add(1, 1));
+		KUNIT_EXPECT_EQ(test, 0, misc_example_add(-1, 1));
+		KUNIT_EXPECT_EQ(test, INT_MAX, misc_example_add(0, INT_MAX));
+		KUNIT_EXPECT_EQ(test, -1, misc_example_add(INT_MAX, INT_MIN));
+	}
+
+	static void misc_example_test_failure(struct kunit *test)
+	{
+		KUNIT_FAIL(test, "This test never passes.");
+	}
+
+	static struct kunit_case misc_example_test_cases[] = {
+		KUNIT_CASE(misc_example_add_test_basic),
+		KUNIT_CASE(misc_example_test_failure),
+		{}
+	};
+
+	static struct kunit_suite misc_example_test_suite = {
+		.name = "misc-example",
+		.test_cases = misc_example_test_cases,
+	};
+	kunit_test_suite(misc_example_test_suite);
+
+Now add the following to ``drivers/misc/Kconfig``:
+
+.. code-block:: kconfig
+
+	config MISC_EXAMPLE_TEST
+		bool "Test for my example"
+		depends on MISC_EXAMPLE && KUNIT
+
+and the following to ``drivers/misc/Makefile``:
+
+.. code-block:: make
+
+	obj-$(CONFIG_MISC_EXAMPLE_TEST) += example-test.o
+
+Now add it to your ``kunitconfig``:
+
+.. code-block:: none
+
+	CONFIG_MISC_EXAMPLE=y
+	CONFIG_MISC_EXAMPLE_TEST=y
+
+Now you can run the test:
+
+.. code-block:: bash
+
+	./tools/testing/kunit/kunit.py
+
+You should see the following failure:
+
+.. code-block:: none
+
+	...
+	[16:08:57] [PASSED] misc-example:misc_example_add_test_basic
+	[16:08:57] [FAILED] misc-example:misc_example_test_failure
+	[16:08:57] EXPECTATION FAILED at drivers/misc/example-test.c:17
+	[16:08:57] 	This test never passes.
+	...
+
+Congrats! You just wrote your first KUnit test!
+
+Next Steps
+==========
+*   Check out the :doc:`usage` page for a more
+    in-depth explanation of KUnit.
diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
new file mode 100644
index 0000000000000..049886006dbce
--- /dev/null
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -0,0 +1,575 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========
+Using KUnit
+===========
+
+The purpose of this document is to describe what KUnit is, how it works, how it
+is intended to be used, and all the concepts and terminology that are needed to
+understand it. This guide assumes a working knowledge of the Linux kernel and
+some basic knowledge of testing.
+
+For a high level introduction to KUnit, including setting up KUnit for your
+project, see :doc:`start`.
+
+Organization of this document
+=============================
+
+This document is organized into two main sections: Testing and Isolating
+Behavior. The first covers what a unit test is and how to use KUnit to write
+them. The second covers how to use KUnit to isolate code and make it possible
+to unit test code that was otherwise un-unit-testable.
+
+Testing
+=======
+
+What is KUnit?
+--------------
+
+"K" is short for "kernel" so "KUnit" is the "(Linux) Kernel Unit Testing
+Framework." KUnit is intended first and foremost for writing unit tests; it is
+general enough that it can be used to write integration tests; however, this is
+a secondary goal. KUnit has no ambition of being the only testing framework for
+the kernel; for example, it does not intend to be an end-to-end testing
+framework.
+
+What is Unit Testing?
+---------------------
+
+A `unit test <https://martinfowler.com/bliki/UnitTest.html>`_ is a test that
+tests code at the smallest possible scope, a *unit* of code. In the C
+programming language that's a function.
+
+Unit tests should be written for all the publicly exposed functions in a
+compilation unit; so that is all the functions that are exported in either a
+*class* (defined below) or all functions which are **not** static.
+
+Writing Tests
+-------------
+
+Test Cases
+~~~~~~~~~~
+
+The fundamental unit in KUnit is the test case. A test case is a function with
+the signature ``void (*)(struct kunit *test)``. It calls a function to be tested
+and then sets *expectations* for what should happen. For example:
+
+.. code-block:: c
+
+	void example_test_success(struct kunit *test)
+	{
+	}
+
+	void example_test_failure(struct kunit *test)
+	{
+		KUNIT_FAIL(test, "This test never passes.");
+	}
+
+In the above example ``example_test_success`` always passes because it does
+nothing; no expectations are set, so all expectations pass. On the other hand
+``example_test_failure`` always fails because it calls ``KUNIT_FAIL``, which is
+a special expectation that logs a message and causes the test case to fail.
+
+Expectations
+~~~~~~~~~~~~
+An *expectation* is a way to specify that you expect a piece of code to do
+something in a test. An expectation is called like a function. A test is made
+by setting expectations about the behavior of a piece of code under test; when
+one or more of the expectations fail, the test case fails and information about
+the failure is logged. For example:
+
+.. code-block:: c
+
+	void add_test_basic(struct kunit *test)
+	{
+		KUNIT_EXPECT_EQ(test, 1, add(1, 0));
+		KUNIT_EXPECT_EQ(test, 2, add(1, 1));
+	}
+
+In the above example ``add_test_basic`` makes a number of assertions about the
+behavior of a function called ``add``; the first parameter is always of type
+``struct kunit *``, which contains information about the current test context;
+the second parameter, in this case, is what the value is expected to be; the
+last value is what the value actually is. If ``add`` passes all of these
+expectations, the test case, ``add_test_basic`` will pass; if any one of these
+expectations fail, the test case will fail.
+
+It is important to understand that a test case *fails* when any expectation is
+violated; however, the test will continue running, potentially trying other
+expectations until the test case ends or is otherwise terminated. This is as
+opposed to *assertions* which are discussed later.
+
+To learn about more expectations supported by KUnit, see :doc:`api/test`.
+
+.. note::
+   A single test case should be pretty short, pretty easy to understand,
+   focused on a single behavior.
+
+For example, if we wanted to properly test the add function above, we would
+create additional tests cases which would each test a different property that an
+add function should have like this:
+
+.. code-block:: c
+
+	void add_test_basic(struct kunit *test)
+	{
+		KUNIT_EXPECT_EQ(test, 1, add(1, 0));
+		KUNIT_EXPECT_EQ(test, 2, add(1, 1));
+	}
+
+	void add_test_negative(struct kunit *test)
+	{
+		KUNIT_EXPECT_EQ(test, 0, add(-1, 1));
+	}
+
+	void add_test_max(struct kunit *test)
+	{
+		KUNIT_EXPECT_EQ(test, INT_MAX, add(0, INT_MAX));
+		KUNIT_EXPECT_EQ(test, -1, add(INT_MAX, INT_MIN));
+	}
+
+	void add_test_overflow(struct kunit *test)
+	{
+		KUNIT_EXPECT_EQ(test, INT_MIN, add(INT_MAX, 1));
+	}
+
+Notice how it is immediately obvious what all the properties that we are testing
+for are.
+
+Assertions
+~~~~~~~~~~
+
+KUnit also has the concept of an *assertion*. An assertion is just like an
+expectation except the assertion immediately terminates the test case if it is
+not satisfied.
+
+For example:
+
+.. code-block:: c
+
+	static void mock_test_do_expect_default_return(struct kunit *test)
+	{
+		struct mock_test_context *ctx = test->priv;
+		struct mock *mock = ctx->mock;
+		int param0 = 5, param1 = -5;
+		const char *two_param_types[] = {"int", "int"};
+		const void *two_params[] = {&param0, &param1};
+		const void *ret;
+
+		ret = mock->do_expect(mock,
+				      "test_printk", test_printk,
+				      two_param_types, two_params,
+				      ARRAY_SIZE(two_params));
+		KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ret);
+		KUNIT_EXPECT_EQ(test, -4, *((int *) ret));
+	}
+
+In this example, the method under test should return a pointer to a value, so
+if the pointer returned by the method is null or an errno, we don't want to
+bother continuing the test since the following expectation could crash the test
+case. `ASSERT_NOT_ERR_OR_NULL(...)` allows us to bail out of the test case if
+the appropriate conditions have not been satisfied to complete the test.
+
+Test Suites
+~~~~~~~~~~~
+
+Now obviously one unit test isn't very helpful; the power comes from having
+many test cases covering all of your behaviors. Consequently it is common to
+have many *similar* tests; in order to reduce duplication in these closely
+related tests most unit testing frameworks provide the concept of a *test
+suite*, in KUnit we call it a *test suite*; all it is is just a collection of
+test cases for a unit of code with a set up function that gets invoked before
+every test cases and then a tear down function that gets invoked after every
+test case completes.
+
+Example:
+
+.. code-block:: c
+
+	static struct kunit_case example_test_cases[] = {
+		KUNIT_CASE(example_test_foo),
+		KUNIT_CASE(example_test_bar),
+		KUNIT_CASE(example_test_baz),
+		{}
+	};
+
+	static struct kunit_suite example_test_suite = {
+		.name = "example",
+		.init = example_test_init,
+		.exit = example_test_exit,
+		.test_cases = example_test_cases,
+	};
+	kunit_test_suite(example_test_suite);
+
+In the above example the test suite, ``example_test_suite``, would run the test
+cases ``example_test_foo``, ``example_test_bar``, and ``example_test_baz``,
+each would have ``example_test_init`` called immediately before it and would
+have ``example_test_exit`` called immediately after it.
+``kunit_test_suite(example_test_suite)`` registers the test suite with the
+KUnit test framework.
+
+.. note::
+   A test case will only be run if it is associated with a test suite.
+
+For a more information on these types of things see the :doc:`api/test`.
+
+Isolating Behavior
+==================
+
+The most important aspect of unit testing that other forms of testing do not
+provide is the ability to limit the amount of code under test to a single unit.
+In practice, this is only possible by being able to control what code gets run
+when the unit under test calls a function and this is usually accomplished
+through some sort of indirection where a function is exposed as part of an API
+such that the definition of that function can be changed without affecting the
+rest of the code base. In the kernel this primarily comes from two constructs,
+classes, structs that contain function pointers that are provided by the
+implementer, and architecture specific functions which have definitions selected
+at compile time.
+
+Classes
+-------
+
+Classes are not a construct that is built into the C programming language;
+however, it is an easily derived concept. Accordingly, pretty much every project
+that does not use a standardized object oriented library (like GNOME's GObject)
+has their own slightly different way of doing object oriented programming; the
+Linux kernel is no exception.
+
+The central concept in kernel object oriented programming is the class. In the
+kernel, a *class* is a struct that contains function pointers. This creates a
+contract between *implementers* and *users* since it forces them to use the
+same function signature without having to call the function directly. In order
+for it to truly be a class, the function pointers must specify that a pointer
+to the class, known as a *class handle*, be one of the parameters; this makes
+it possible for the member functions (also known as *methods*) to have access
+to member variables (more commonly known as *fields*) allowing the same
+implementation to have multiple *instances*.
+
+Typically a class can be *overridden* by *child classes* by embedding the
+*parent class* in the child class. Then when a method provided by the child
+class is called, the child implementation knows that the pointer passed to it is
+of a parent contained within the child; because of this, the child can compute
+the pointer to itself because the pointer to the parent is always a fixed offset
+from the pointer to the child; this offset is the offset of the parent contained
+in the child struct. For example:
+
+.. code-block:: c
+
+	struct shape {
+		int (*area)(struct shape *this);
+	};
+
+	struct rectangle {
+		struct shape parent;
+		int length;
+		int width;
+	};
+
+	int rectangle_area(struct shape *this)
+	{
+		struct rectangle *self = container_of(this, struct shape, parent);
+
+		return self->length * self->width;
+	};
+
+	void rectangle_new(struct rectangle *self, int length, int width)
+	{
+		self->parent.area = rectangle_area;
+		self->length = length;
+		self->width = width;
+	}
+
+In this example (as in most kernel code) the operation of computing the pointer
+to the child from the pointer to the parent is done by ``container_of``.
+
+Faking Classes
+~~~~~~~~~~~~~~
+
+In order to unit test a piece of code that calls a method in a class, the
+behavior of the method must be controllable, otherwise the test ceases to be a
+unit test and becomes an integration test.
+
+A fake just provides an implementation of a piece of code that is different than
+what runs in a production instance, but behaves identically from the standpoint
+of the callers; this is usually done to replace a dependency that is hard to
+deal with, or is slow.
+
+A good example for this might be implementing a fake EEPROM that just stores the
+"contents" in an internal buffer. For example, let's assume we have a class that
+represents an EEPROM:
+
+.. code-block:: c
+
+	struct eeprom {
+		ssize_t (*read)(struct eeprom *this, size_t offset, char *buffer, size_t count);
+		ssize_t (*write)(struct eeprom *this, size_t offset, const char *buffer, size_t count);
+	};
+
+And we want to test some code that buffers writes to the EEPROM:
+
+.. code-block:: c
+
+	struct eeprom_buffer {
+		ssize_t (*write)(struct eeprom_buffer *this, const char *buffer, size_t count);
+		int flush(struct eeprom_buffer *this);
+		size_t flush_count; /* Flushes when buffer exceeds flush_count. */
+	};
+
+	struct eeprom_buffer *new_eeprom_buffer(struct eeprom *eeprom);
+	void destroy_eeprom_buffer(struct eeprom *eeprom);
+
+We can easily test this code by *faking out* the underlying EEPROM:
+
+.. code-block:: c
+
+	struct fake_eeprom {
+		struct eeprom parent;
+		char contents[FAKE_EEPROM_CONTENTS_SIZE];
+	};
+
+	ssize_t fake_eeprom_read(struct eeprom *parent, size_t offset, char *buffer, size_t count)
+	{
+		struct fake_eeprom *this = container_of(parent, struct fake_eeprom, parent);
+
+		count = min(count, FAKE_EEPROM_CONTENTS_SIZE - offset);
+		memcpy(buffer, this->contents + offset, count);
+
+		return count;
+	}
+
+	ssize_t fake_eeprom_write(struct eeprom *this, size_t offset, const char *buffer, size_t count)
+	{
+		struct fake_eeprom *this = container_of(parent, struct fake_eeprom, parent);
+
+		count = min(count, FAKE_EEPROM_CONTENTS_SIZE - offset);
+		memcpy(this->contents + offset, buffer, count);
+
+		return count;
+	}
+
+	void fake_eeprom_init(struct fake_eeprom *this)
+	{
+		this->parent.read = fake_eeprom_read;
+		this->parent.write = fake_eeprom_write;
+		memset(this->contents, 0, FAKE_EEPROM_CONTENTS_SIZE);
+	}
+
+We can now use it to test ``struct eeprom_buffer``:
+
+.. code-block:: c
+
+	struct eeprom_buffer_test {
+		struct fake_eeprom *fake_eeprom;
+		struct eeprom_buffer *eeprom_buffer;
+	};
+
+	static void eeprom_buffer_test_does_not_write_until_flush(struct kunit *test)
+	{
+		struct eeprom_buffer_test *ctx = test->priv;
+		struct eeprom_buffer *eeprom_buffer = ctx->eeprom_buffer;
+		struct fake_eeprom *fake_eeprom = ctx->fake_eeprom;
+		char buffer[] = {0xff};
+
+		eeprom_buffer->flush_count = SIZE_MAX;
+
+		eeprom_buffer->write(eeprom_buffer, buffer, 1);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[0], 0);
+
+		eeprom_buffer->write(eeprom_buffer, buffer, 1);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[1], 0);
+
+		eeprom_buffer->flush(eeprom_buffer);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[0], 0xff);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[1], 0xff);
+	}
+
+	static void eeprom_buffer_test_flushes_after_flush_count_met(struct kunit *test)
+	{
+		struct eeprom_buffer_test *ctx = test->priv;
+		struct eeprom_buffer *eeprom_buffer = ctx->eeprom_buffer;
+		struct fake_eeprom *fake_eeprom = ctx->fake_eeprom;
+		char buffer[] = {0xff};
+
+		eeprom_buffer->flush_count = 2;
+
+		eeprom_buffer->write(eeprom_buffer, buffer, 1);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[0], 0);
+
+		eeprom_buffer->write(eeprom_buffer, buffer, 1);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[0], 0xff);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[1], 0xff);
+	}
+
+	static void eeprom_buffer_test_flushes_increments_of_flush_count(struct kunit *test)
+	{
+		struct eeprom_buffer_test *ctx = test->priv;
+		struct eeprom_buffer *eeprom_buffer = ctx->eeprom_buffer;
+		struct fake_eeprom *fake_eeprom = ctx->fake_eeprom;
+		char buffer[] = {0xff, 0xff};
+
+		eeprom_buffer->flush_count = 2;
+
+		eeprom_buffer->write(eeprom_buffer, buffer, 1);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[0], 0);
+
+		eeprom_buffer->write(eeprom_buffer, buffer, 2);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[0], 0xff);
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[1], 0xff);
+		/* Should have only flushed the first two bytes. */
+		KUNIT_EXPECT_EQ(test, fake_eeprom->contents[2], 0);
+	}
+
+	static int eeprom_buffer_test_init(struct kunit *test)
+	{
+		struct eeprom_buffer_test *ctx;
+
+		ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+		ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+		ctx->fake_eeprom = kunit_kzalloc(test, sizeof(*ctx->fake_eeprom), GFP_KERNEL);
+		ASSERT_NOT_ERR_OR_NULL(test, ctx->fake_eeprom);
+
+		ctx->eeprom_buffer = new_eeprom_buffer(&ctx->fake_eeprom->parent);
+		ASSERT_NOT_ERR_OR_NULL(test, ctx->eeprom_buffer);
+
+		test->priv = ctx;
+
+		return 0;
+	}
+
+	static void eeprom_buffer_test_exit(struct kunit *test)
+	{
+		struct eeprom_buffer_test *ctx = test->priv;
+
+		destroy_eeprom_buffer(ctx->eeprom_buffer);
+	}
+
+.. _kunit-on-non-uml:
+
+KUnit on non-UML architectures
+==============================
+
+By default KUnit uses UML as a way to provide dependencies for code under test.
+Under most circumstances KUnit's usage of UML should be treated as an
+implementation detail of how KUnit works under the hood. Nevertheless, there
+are instances where being able to run architecture specific code, or test
+against real hardware is desirable. For these reasons KUnit supports running on
+other architectures.
+
+Running existing KUnit tests on non-UML architectures
+-----------------------------------------------------
+
+There are some special considerations when running existing KUnit tests on
+non-UML architectures:
+
+*   Hardware may not be deterministic, so a test that always passes or fails
+    when run under UML may not always do so on real hardware.
+*   Hardware and VM environments may not be hermetic. KUnit tries its best to
+    provide a hermetic environment to run tests; however, it cannot manage state
+    that it doesn't know about outside of the kernel. Consequently, tests that
+    may be hermetic on UML may not be hermetic on other architectures.
+*   Some features and tooling may not be supported outside of UML.
+*   Hardware and VMs are slower than UML.
+
+None of these are reasons not to run your KUnit tests on real hardware; they are
+only things to be aware of when doing so.
+
+The biggest impediment will likely be that certain KUnit features and
+infrastructure may not support your target environment. For example, at this
+time the KUnit Wrapper (``tools/testing/kunit/kunit.py``) does not work outside
+of UML. Unfortunately, there is no way around this. Using UML (or even just a
+particular architecture) allows us to make a lot of assumptions that make it
+possible to do things which might otherwise be impossible.
+
+Nevertheless, all core KUnit framework features are fully supported on all
+architectures, and using them is straightforward: all you need to do is to take
+your kunitconfig, your Kconfig options for the tests you would like to run, and
+merge them into whatever config your are using for your platform. That's it!
+
+For example, let's say you have the following kunitconfig:
+
+.. code-block:: none
+
+	CONFIG_KUNIT=y
+	CONFIG_KUNIT_EXAMPLE_TEST=y
+
+If you wanted to run this test on an x86 VM, you might add the following config
+options to your ``.config``:
+
+.. code-block:: none
+
+	CONFIG_KUNIT=y
+	CONFIG_KUNIT_EXAMPLE_TEST=y
+	CONFIG_SERIAL_8250=y
+	CONFIG_SERIAL_8250_CONSOLE=y
+
+All these new options do is enable support for a common serial console needed
+for logging.
+
+Next, you could build a kernel with these tests as follows:
+
+
+.. code-block:: bash
+
+	make ARCH=x86 olddefconfig
+	make ARCH=x86
+
+Once you have built a kernel, you could run it on QEMU as follows:
+
+.. code-block:: bash
+
+	qemu-system-x86_64 -enable-kvm \
+			   -m 1024 \
+			   -kernel arch/x86_64/boot/bzImage \
+			   -append 'console=ttyS0' \
+			   --nographic
+
+Interspersed in the kernel logs you might see the following:
+
+.. code-block:: none
+
+	TAP version 14
+		# Subtest: example
+		1..1
+		# example_simple_test: initializing
+		ok 1 - example_simple_test
+	ok 1 - example
+
+Congratulations, you just ran a KUnit test on the x86 architecture!
+
+Writing new tests for other architectures
+-----------------------------------------
+
+The first thing you must do is ask yourself whether it is necessary to write a
+KUnit test for a specific architecture, and then whether it is necessary to
+write that test for a particular piece of hardware. In general, writing a test
+that depends on having access to a particular piece of hardware or software (not
+included in the Linux source repo) should be avoided at all costs.
+
+Even if you only ever plan on running your KUnit test on your hardware
+configuration, other people may want to run your tests and may not have access
+to your hardware. If you write your test to run on UML, then anyone can run your
+tests without knowing anything about your particular setup, and you can still
+run your tests on your hardware setup just by compiling for your architecture.
+
+.. important::
+   Always prefer tests that run on UML to tests that only run under a particular
+   architecture, and always prefer tests that run under QEMU or another easy
+   (and monitarily free) to obtain software environment to a specific piece of
+   hardware.
+
+Nevertheless, there are still valid reasons to write an architecture or hardware
+specific test: for example, you might want to test some code that really belongs
+in ``arch/some-arch/*``. Even so, try your best to write the test so that it
+does not depend on physical hardware: if some of your test cases don't need the
+hardware, only require the hardware for tests that actually need it.
+
+Now that you have narrowed down exactly what bits are hardware specific, the
+actual procedure for writing and running the tests is pretty much the same as
+writing normal KUnit tests. One special caveat is that you have to reset
+hardware state in between test cases; if this is not possible, you may only be
+able to run one test case per invocation.
+
+.. TODO(brendanhiggins@google.com): Add an actual example of an architecture
+   dependent KUnit test.
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 16/18] MAINTAINERS: add entry for KUnit the unit testing framework
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (14 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 15/18] Documentation: kunit: add documentation for KUnit Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section Brendan Higgins
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Add myself as maintainer of KUnit, the Linux kernel's unit testing
framework.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 MAINTAINERS | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 677ef41cb012c..48d04d180a988 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8599,6 +8599,17 @@ S:	Maintained
 F:	tools/testing/selftests/
 F:	Documentation/dev-tools/kselftest*
 
+KERNEL UNIT TESTING FRAMEWORK (KUnit)
+M:	Brendan Higgins <brendanhiggins@google.com>
+L:	linux-kselftest@vger.kernel.org
+L:	kunit-dev@googlegroups.com
+W:	https://google.github.io/kunit-docs/third_party/kernel/docs/
+S:	Maintained
+F:	Documentation/dev-tools/kunit/
+F:	include/kunit/
+F:	kunit/
+F:	tools/testing/kunit/
+
 KERNEL USERMODE HELPER
 M:	Luis Chamberlain <mcgrof@kernel.org>
 L:	linux-kernel@vger.kernel.org
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (15 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 16/18] MAINTAINERS: add entry for KUnit the unit testing framework Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  2019-07-12  8:17 ` [PATCH v9 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section Brendan Higgins
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Iurii Zaikin, Brendan Higgins

From: Iurii Zaikin <yzaikin@google.com>

KUnit tests for initialized data behavior of proc_dointvec that is
explicitly checked in the code. Includes basic parsing tests including
int min/max overflow.

Signed-off-by: Iurii Zaikin <yzaikin@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
---
 kernel/Makefile      |   2 +
 kernel/sysctl-test.c | 392 +++++++++++++++++++++++++++++++++++++++++++
 lib/Kconfig.debug    |  11 ++
 3 files changed, 405 insertions(+)
 create mode 100644 kernel/sysctl-test.c

diff --git a/kernel/Makefile b/kernel/Makefile
index a8d923b5481ba..50fd511cd0ee0 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -114,6 +114,8 @@ obj-$(CONFIG_HAS_IOMEM) += iomem.o
 obj-$(CONFIG_ZONE_DEVICE) += memremap.o
 obj-$(CONFIG_RSEQ) += rseq.o
 
+obj-$(CONFIG_SYSCTL_KUNIT_TEST) += sysctl-test.o
+
 obj-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak.o
 KASAN_SANITIZE_stackleak.o := n
 KCOV_INSTRUMENT_stackleak.o := n
diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
new file mode 100644
index 0000000000000..2a63241a8453b
--- /dev/null
+++ b/kernel/sysctl-test.c
@@ -0,0 +1,392 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test of proc sysctl.
+ */
+
+#include <kunit/test.h>
+#include <linux/sysctl.h>
+
+#define KUNIT_PROC_READ 0
+#define KUNIT_PROC_WRITE 1
+
+static int i_zero;
+static int i_one_hundred = 100;
+
+/*
+ * Test that proc_dointvec will not try to use a NULL .data field even when the
+ * length is non-zero.
+ */
+static void sysctl_test_api_dointvec_null_tbl_data(struct kunit *test)
+{
+	struct ctl_table null_data_table = {
+		.procname = "foo",
+		/*
+		 * Here we are testing that proc_dointvec behaves correctly when
+		 * we give it a NULL .data field. Normally this would point to a
+		 * piece of memory where the value would be stored.
+		 */
+		.data		= NULL,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	/*
+	 * proc_dointvec expects a buffer in user space, so we allocate one. We
+	 * also need to cast it to __user so sparse doesn't get mad.
+	 */
+	void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
+							   GFP_USER);
+	size_t len;
+	loff_t pos;
+
+	/*
+	 * We don't care what the starting length is since proc_dointvec should
+	 * not try to read because .data is NULL.
+	 */
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table,
+					       KUNIT_PROC_READ, buffer, &len,
+					       &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+
+	/*
+	 * See above.
+	 */
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&null_data_table,
+					       KUNIT_PROC_WRITE, buffer, &len,
+					       &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+}
+
+/*
+ * Similar to the previous test, we create a struct ctrl_table that has a .data
+ * field that proc_dointvec cannot do anything with; however, this time it is
+ * because we tell proc_dointvec that the size is 0.
+ */
+static void sysctl_test_api_dointvec_table_maxlen_unset(struct kunit *test)
+{
+	int data = 0;
+	struct ctl_table data_maxlen_unset_table = {
+		.procname = "foo",
+		.data		= &data,
+		/*
+		 * So .data is no longer NULL, but we tell proc_dointvec its
+		 * length is 0, so it still shouldn't try to use it.
+		 */
+		.maxlen		= 0,
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
+							   GFP_USER);
+	size_t len;
+	loff_t pos;
+
+	/*
+	 * As before, we don't care what buffer length is because proc_dointvec
+	 * cannot do anything because its internal .data buffer has zero length.
+	 */
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table,
+					       KUNIT_PROC_READ, buffer, &len,
+					       &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+
+	/*
+	 * See previous comment.
+	 */
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&data_maxlen_unset_table,
+					       KUNIT_PROC_WRITE, buffer, &len,
+					       &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+}
+
+/*
+ * Here we provide a valid struct ctl_table, but we try to read and write from
+ * it using a buffer of zero length, so it should still fail in a similar way as
+ * before.
+ */
+static void sysctl_test_api_dointvec_table_len_is_zero(struct kunit *test)
+{
+	int data = 0;
+	/* Good table. */
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
+							   GFP_USER);
+	/*
+	 * However, now our read/write buffer has zero length.
+	 */
+	size_t len = 0;
+	loff_t pos;
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer,
+					       &len, &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE, buffer,
+					       &len, &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+}
+
+/*
+ * Test that proc_dointvec refuses to read when the file position is non-zero.
+ */
+static void sysctl_test_api_dointvec_table_read_but_position_set(
+		struct kunit *test)
+{
+	int data = 0;
+	/* Good table. */
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void __user *buffer = (void __user *)kunit_kzalloc(test, sizeof(int),
+							   GFP_USER);
+	/*
+	 * We don't care about our buffer length because we start off with a
+	 * non-zero file position.
+	 */
+	size_t len = 1234;
+	/*
+	 * proc_dointvec should refuse to read into the buffer since the file
+	 * pos is non-zero.
+	 */
+	loff_t pos = 1;
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ, buffer,
+					       &len, &pos));
+	KUNIT_EXPECT_EQ(test, (size_t)0, len);
+}
+
+/*
+ * Test that we can read a two digit number in a sufficiently size buffer.
+ * Nothing fancy.
+ */
+static void sysctl_test_dointvec_read_happy_single_positive(struct kunit *test)
+{
+	int data = 0;
+	/* Good table. */
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	size_t len = 4;
+	loff_t pos = 0;
+	char *buffer = kunit_kzalloc(test, len, GFP_USER);
+	char __user *user_buffer = (char __user *)buffer;
+	/* Store 13 in the data field. */
+	*((int *)table.data) = 13;
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ,
+					       user_buffer, &len, &pos));
+	KUNIT_ASSERT_EQ(test, (size_t)3, len);
+	buffer[len] = '\0';
+	/* And we read 13 back out. */
+	KUNIT_EXPECT_STREQ(test, "13\n", buffer);
+}
+
+/*
+ * Same as previous test, just now with negative numbers.
+ */
+static void sysctl_test_dointvec_read_happy_single_negative(struct kunit *test)
+{
+	int data = 0;
+	/* Good table. */
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	size_t len = 5;
+	loff_t pos = 0;
+	char *buffer = kunit_kzalloc(test, len, GFP_USER);
+	char __user *user_buffer = (char __user *)buffer;
+	*((int *)table.data) = -16;
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_READ,
+					       user_buffer, &len, &pos));
+	KUNIT_ASSERT_EQ(test, (size_t)4, len);
+	buffer[len] = '\0';
+	KUNIT_EXPECT_STREQ(test, "-16\n", (char *)buffer);
+}
+
+/*
+ * Test that a simple positive write works.
+ */
+static void sysctl_test_dointvec_write_happy_single_positive(struct kunit *test)
+{
+	int data = 0;
+	/* Good table. */
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	char input[] = "9";
+	size_t len = sizeof(input) - 1;
+	loff_t pos = 0;
+	char *buffer = kunit_kzalloc(test, len, GFP_USER);
+	char __user *user_buffer = (char __user *)buffer;
+
+	memcpy(buffer, input, len);
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE,
+					       user_buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, (size_t)pos);
+	KUNIT_EXPECT_EQ(test, 9, *((int *)table.data));
+}
+
+/*
+ * Same as previous test, but now with negative numbers.
+ */
+static void sysctl_test_dointvec_write_happy_single_negative(struct kunit *test)
+{
+	int data = 0;
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	char input[] = "-9";
+	size_t len = sizeof(input) - 1;
+	loff_t pos = 0;
+	char *buffer = kunit_kzalloc(test, len, GFP_USER);
+	char __user *user_buffer = (char __user *)buffer;
+
+	memcpy(buffer, input, len);
+
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, KUNIT_PROC_WRITE,
+					       user_buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, (size_t)pos);
+	KUNIT_EXPECT_EQ(test, -9, *((int *)table.data));
+}
+
+/*
+ * Test that writing a value smaller than the minimum possible value is not
+ * allowed.
+ */
+static void sysctl_test_api_dointvec_write_single_less_int_min(
+		struct kunit *test)
+{
+	int data = 0;
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	size_t max_len = 32, len = max_len;
+	loff_t pos = 0;
+	char *buffer = kunit_kzalloc(test, max_len, GFP_USER);
+	char __user *user_buffer = (char __user *)buffer;
+	unsigned long abs_of_less_than_min = (unsigned long)INT_MAX
+					     - (INT_MAX + INT_MIN) + 1;
+
+	/*
+	 * We use this rigmarole to create a string that contains a value one
+	 * less than the minimum accepted value.
+	 */
+	KUNIT_ASSERT_LT(test,
+			(size_t)snprintf(buffer, max_len, "-%lu",
+					 abs_of_less_than_min),
+			max_len);
+
+	KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE,
+						     user_buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, max_len, len);
+	KUNIT_EXPECT_EQ(test, 0, *((int *)table.data));
+}
+
+/*
+ * Test that writing the maximum possible value works.
+ */
+static void sysctl_test_api_dointvec_write_single_greater_int_max(
+		struct kunit *test)
+{
+	int data = 0;
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &data,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	size_t max_len = 32, len = max_len;
+	loff_t pos = 0;
+	char *buffer = kunit_kzalloc(test, max_len, GFP_USER);
+	char __user *user_buffer = (char __user *)buffer;
+	unsigned long greater_than_max = (unsigned long)INT_MAX + 1;
+
+	KUNIT_ASSERT_GT(test, greater_than_max, (unsigned long)INT_MAX);
+	KUNIT_ASSERT_LT(test, (size_t)snprintf(buffer, max_len, "%lu",
+					       greater_than_max),
+			max_len);
+	KUNIT_EXPECT_EQ(test, -EINVAL, proc_dointvec(&table, KUNIT_PROC_WRITE,
+						     user_buffer, &len, &pos));
+	KUNIT_ASSERT_EQ(test, max_len, len);
+	KUNIT_EXPECT_EQ(test, 0, *((int *)table.data));
+}
+
+static struct kunit_case sysctl_test_cases[] = {
+	KUNIT_CASE(sysctl_test_api_dointvec_null_tbl_data),
+	KUNIT_CASE(sysctl_test_api_dointvec_table_maxlen_unset),
+	KUNIT_CASE(sysctl_test_api_dointvec_table_len_is_zero),
+	KUNIT_CASE(sysctl_test_api_dointvec_table_read_but_position_set),
+	KUNIT_CASE(sysctl_test_dointvec_read_happy_single_positive),
+	KUNIT_CASE(sysctl_test_dointvec_read_happy_single_negative),
+	KUNIT_CASE(sysctl_test_dointvec_write_happy_single_positive),
+	KUNIT_CASE(sysctl_test_dointvec_write_happy_single_negative),
+	KUNIT_CASE(sysctl_test_api_dointvec_write_single_less_int_min),
+	KUNIT_CASE(sysctl_test_api_dointvec_write_single_greater_int_max),
+	{}
+};
+
+static struct kunit_suite sysctl_test_suite = {
+	.name = "sysctl_test",
+	.test_cases = sysctl_test_cases,
+};
+
+kunit_test_suite(sysctl_test_suite);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cbdfae3798965..6f8007800a76f 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1939,6 +1939,17 @@ config TEST_SYSCTL
 
 	  If unsure, say N.
 
+config SYSCTL_KUNIT_TEST
+	bool "KUnit test for sysctl"
+	depends on KUNIT
+	help
+	  This builds the proc sysctl unit test, which runs on boot.
+	  Tests the API contract and implementation correctness of sysctl.
+	  For more information on KUnit and unit tests in general please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.
+
 config TEST_UDELAY
 	tristate "udelay test driver"
 	help
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* [PATCH v9 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section
  2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
                   ` (16 preceding siblings ...)
  2019-07-12  8:17 ` [PATCH v9 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() Brendan Higgins
@ 2019-07-12  8:17 ` Brendan Higgins
  17 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-12  8:17 UTC (permalink / raw)
  To: frowand.list, gregkh, jpoimboe, keescook, kieran.bingham, mcgrof,
	peterz, robh, sboyd, shuah, tytso, yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins, Iurii Zaikin

Add entry for the new proc sysctl KUnit test to the PROC SYSCTL section,
and add Iurii as a maintainer.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
---
 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 48d04d180a988..f8204c75114da 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12721,12 +12721,14 @@ F:	Documentation/filesystems/proc.txt
 PROC SYSCTL
 M:	Luis Chamberlain <mcgrof@kernel.org>
 M:	Kees Cook <keescook@chromium.org>
+M:	Iurii Zaikin <yzaikin@google.com>
 L:	linux-kernel@vger.kernel.org
 L:	linux-fsdevel@vger.kernel.org
 S:	Maintained
 F:	fs/proc/proc_sysctl.c
 F:	include/linux/sysctl.h
 F:	kernel/sysctl.c
+F:	kernel/sysctl-test.c
 F:	tools/testing/selftests/sysctl/
 
 PS3 NETWORK SUPPORT
-- 
2.22.0.410.gd8fdbe21b5-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 01/18] kunit: test: add KUnit test runner core
  2019-07-12  8:17 ` [PATCH v9 01/18] kunit: test: add KUnit test runner core Brendan Higgins
@ 2019-07-15 20:10   ` Stephen Boyd
  2019-07-15 21:25     ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 20:10 UTC (permalink / raw)
  To: Brendan Higgins, frowand.list, gregkh, jpoimboe, keescook,
	kieran.bingham, mcgrof, peterz, robh, shuah, tytso,
	yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Quoting Brendan Higgins (2019-07-12 01:17:27)
> Add core facilities for defining unit tests; this provides a common way
> to define test cases, functions that execute code which is under test
> and determine whether the code under test behaves as expected; this also
> provides a way to group together related test cases in test suites (here
> we call them test_modules).
> 
> Just define test cases and how to execute them for now; setting
> expectations on code will be defined later.
> 
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>

Reviewed-by: Stephen Boyd <sboyd@kernel.org>

Minor nits below.

> diff --git a/kunit/test.c b/kunit/test.c
> new file mode 100644
> index 0000000000000..571e4c65deb5c
> --- /dev/null
> +++ b/kunit/test.c
> @@ -0,0 +1,189 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Base unit test (KUnit) API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <kunit/test.h>
> +
> +static void kunit_set_failure(struct kunit *test)
> +{
> +       WRITE_ONCE(test->success, false);
> +}
> +
[...]
> +
> +void kunit_init_test(struct kunit *test, const char *name)
> +{
> +       test->name = name;
> +       test->success = true;
> +}
> +
> +/*
> + * Performs all logic to run a test case.
> + */
> +static void kunit_run_case(struct kunit_suite *suite,
> +                          struct kunit_case *test_case)
> +{
> +       struct kunit test;
> +       int ret = 0;
> +
> +       kunit_init_test(&test, test_case->name);
> +
> +       if (suite->init) {
> +               ret = suite->init(&test);

Can you push the ret definition into this if scope? That way we can
avoid default initialize to 0 for it.

> +               if (ret) {
> +                       kunit_err(&test, "failed to initialize: %d\n", ret);
> +                       kunit_set_failure(&test);

Do we need to 'test_case->success = test.success' here too? Or is the
test failure extracted somewhere else?

> +                       return;
> +               }
> +       }
> +
> +       test_case->run_case(&test);
> +
> +       if (suite->exit)
> +               suite->exit(&test);
> +
> +       test_case->success = test.success;

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 02/18] kunit: test: add test resource management API
  2019-07-12  8:17 ` [PATCH v9 02/18] kunit: test: add test resource management API Brendan Higgins
@ 2019-07-15 20:24   ` Stephen Boyd
  2019-07-15 20:30     ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 20:24 UTC (permalink / raw)
  To: Brendan Higgins, frowand.list, gregkh, jpoimboe, keescook,
	kieran.bingham, mcgrof, peterz, robh, shuah, tytso,
	yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Quoting Brendan Higgins (2019-07-12 01:17:28)
> diff --git a/kunit/test.c b/kunit/test.c
> index 571e4c65deb5c..f165c9d8e10b0 100644
> --- a/kunit/test.c
> +++ b/kunit/test.c
> @@ -171,6 +175,96 @@ int kunit_run_tests(struct kunit_suite *suite)
>         return 0;
>  }
>  
> +struct kunit_resource *kunit_alloc_resource(struct kunit *test,
> +                                           kunit_resource_init_t init,
> +                                           kunit_resource_free_t free,
> +                                           void *context)
> +{
> +       struct kunit_resource *res;
> +       int ret;
> +
> +       res = kzalloc(sizeof(*res), GFP_KERNEL);

This uses GFP_KERNEL.

> +       if (!res)
> +               return NULL;
> +
> +       ret = init(res, context);
> +       if (ret)
> +               return NULL;
> +
> +       res->free = free;
> +       mutex_lock(&test->lock);

And this can sleep.

> +       list_add_tail(&res->node, &test->resources);
> +       mutex_unlock(&test->lock);
> +
> +       return res;
> +}
> +
> +void kunit_free_resource(struct kunit *test, struct kunit_resource *res)

Should probably add a note that we assume the test lock is held here, or
even add a lockdep_assert_held(&test->lock) into the function to
document that and assert it at the same time.

> +{
> +       res->free(res);
> +       list_del(&res->node);
> +       kfree(res);
> +}
> +
> +struct kunit_kmalloc_params {
> +       size_t size;
> +       gfp_t gfp;
> +};
> +
> +static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
> +{
> +       struct kunit_kmalloc_params *params = context;
> +
> +       res->allocation = kmalloc(params->size, params->gfp);
> +       if (!res->allocation)
> +               return -ENOMEM;
> +
> +       return 0;
> +}
> +
> +static void kunit_kmalloc_free(struct kunit_resource *res)
> +{
> +       kfree(res->allocation);
> +}
> +
> +void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
> +{
> +       struct kunit_kmalloc_params params;
> +       struct kunit_resource *res;
> +
> +       params.size = size;
> +       params.gfp = gfp;
> +
> +       res = kunit_alloc_resource(test,

This calls that sleeping function above...

> +                                  kunit_kmalloc_init,
> +                                  kunit_kmalloc_free,
> +                                  &params);

but this passes a GFP flags parameter through to the
kunit_kmalloc_init() function. How is this going to work if some code
uses GFP_ATOMIC, but then we try to allocate and sleep in
kunit_alloc_resource() with GFP_KERNEL? 

One solution would be to piggyback on all the existing devres allocation
logic we already have and make each struct kunit a device that we pass
into the devres functions. A far simpler solution would be to just
copy/paste what devres does and use a spinlock and an allocation
function that takes GFP flags.

> +
> +       if (res)
> +               return res->allocation;
> +
> +       return NULL;
> +}

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 02/18] kunit: test: add test resource management API
  2019-07-15 20:24   ` Stephen Boyd
@ 2019-07-15 20:30     ` Brendan Higgins
  2019-07-15 20:51       ` Stephen Boyd
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-15 20:30 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 15, 2019 at 1:24 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-12 01:17:28)
> > diff --git a/kunit/test.c b/kunit/test.c
> > index 571e4c65deb5c..f165c9d8e10b0 100644
> > --- a/kunit/test.c
> > +++ b/kunit/test.c
> > @@ -171,6 +175,96 @@ int kunit_run_tests(struct kunit_suite *suite)
> >         return 0;
> >  }
> >
> > +struct kunit_resource *kunit_alloc_resource(struct kunit *test,
> > +                                           kunit_resource_init_t init,
> > +                                           kunit_resource_free_t free,
> > +                                           void *context)
> > +{
> > +       struct kunit_resource *res;
> > +       int ret;
> > +
> > +       res = kzalloc(sizeof(*res), GFP_KERNEL);
>
> This uses GFP_KERNEL.
>
> > +       if (!res)
> > +               return NULL;
> > +
> > +       ret = init(res, context);
> > +       if (ret)
> > +               return NULL;
> > +
> > +       res->free = free;
> > +       mutex_lock(&test->lock);
>
> And this can sleep.
>
> > +       list_add_tail(&res->node, &test->resources);
> > +       mutex_unlock(&test->lock);
> > +
> > +       return res;
> > +}
> > +
> > +void kunit_free_resource(struct kunit *test, struct kunit_resource *res)
>
> Should probably add a note that we assume the test lock is held here, or
> even add a lockdep_assert_held(&test->lock) into the function to
> document that and assert it at the same time.

Seems reasonable.

> > +{
> > +       res->free(res);
> > +       list_del(&res->node);
> > +       kfree(res);
> > +}
> > +
> > +struct kunit_kmalloc_params {
> > +       size_t size;
> > +       gfp_t gfp;
> > +};
> > +
> > +static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
> > +{
> > +       struct kunit_kmalloc_params *params = context;
> > +
> > +       res->allocation = kmalloc(params->size, params->gfp);
> > +       if (!res->allocation)
> > +               return -ENOMEM;
> > +
> > +       return 0;
> > +}
> > +
> > +static void kunit_kmalloc_free(struct kunit_resource *res)
> > +{
> > +       kfree(res->allocation);
> > +}
> > +
> > +void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
> > +{
> > +       struct kunit_kmalloc_params params;
> > +       struct kunit_resource *res;
> > +
> > +       params.size = size;
> > +       params.gfp = gfp;
> > +
> > +       res = kunit_alloc_resource(test,
>
> This calls that sleeping function above...
>
> > +                                  kunit_kmalloc_init,
> > +                                  kunit_kmalloc_free,
> > +                                  &params);
>
> but this passes a GFP flags parameter through to the
> kunit_kmalloc_init() function. How is this going to work if some code
> uses GFP_ATOMIC, but then we try to allocate and sleep in
> kunit_alloc_resource() with GFP_KERNEL?

Yeah, that's an inconsistency. I need to fix that.

> One solution would be to piggyback on all the existing devres allocation
> logic we already have and make each struct kunit a device that we pass
> into the devres functions. A far simpler solution would be to just
> copy/paste what devres does and use a spinlock and an allocation
> function that takes GFP flags.

Yeah, that's what I did originally, but I thought from the discussion
on patch 01 that you thought a spinlock was overkill for struct kunit.
I take it you only meant in that initial patch?

> > +
> > +       if (res)
> > +               return res->allocation;
> > +
> > +       return NULL;
> > +}

Cheers

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-12  8:17 ` [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder Brendan Higgins
@ 2019-07-15 20:43   ` Stephen Boyd
  2019-07-15 21:11     ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 20:43 UTC (permalink / raw)
  To: Brendan Higgins, frowand.list, gregkh, jpoimboe, keescook,
	kieran.bingham, mcgrof, peterz, robh, shuah, tytso,
	yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Quoting Brendan Higgins (2019-07-12 01:17:29)
> diff --git a/include/kunit/string-stream.h b/include/kunit/string-stream.h
> new file mode 100644
> index 0000000000000..0552a05781afe
> --- /dev/null
> +++ b/include/kunit/string-stream.h
> @@ -0,0 +1,49 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * C++ stream style string builder used in KUnit for building messages.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#ifndef _KUNIT_STRING_STREAM_H
> +#define _KUNIT_STRING_STREAM_H
> +
> +#include <linux/types.h>
> +#include <linux/spinlock.h>
> +#include <linux/kref.h>

What is this include for? I'd expect to see linux/list.h instead.

> +#include <stdarg.h>
> +
> +struct string_stream_fragment {
> +       struct list_head node;
> +       char *fragment;
> +};
> +
> +struct string_stream {
> +       size_t length;
> +       struct list_head fragments;
> +       /* length and fragments are protected by this lock */
> +       spinlock_t lock;
> +};
> +
> diff --git a/kunit/string-stream.c b/kunit/string-stream.c
> new file mode 100644
> index 0000000000000..0463a92dad74b
> --- /dev/null
> +++ b/kunit/string-stream.c
> @@ -0,0 +1,147 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * C++ stream style string builder used in KUnit for building messages.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#include <linux/list.h>
> +#include <linux/slab.h>
> +#include <kunit/string-stream.h>
> +#include <kunit/test.h>
> +
> +int string_stream_vadd(struct string_stream *stream,
> +                      const char *fmt,
> +                      va_list args)
> +{
> +       struct string_stream_fragment *frag_container;
> +       int len;
> +       va_list args_for_counting;
> +       unsigned long flags;
> +
> +       /* Make a copy because `vsnprintf` could change it */
> +       va_copy(args_for_counting, args);
> +
> +       /* Need space for null byte. */
> +       len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
> +
> +       va_end(args_for_counting);
> +
> +       frag_container = kmalloc(sizeof(*frag_container), GFP_KERNEL);

This is confusing in that it allocates with GFP_KERNEL but then grabs a
spinlock to add and remove from the fragment list. Is it ever going to
be called from a place where it can't sleep? If so, the GFP_KERNEL needs
to be changed. Otherwise, maybe a mutex would work better to protect
access to the fragment list.

I also wonder if it would be better to just have a big slop buffer of a
4K page or something so that we almost never have to allocate anything
with a string_stream and we can just rely on a reader consuming data
while writers are writing. That might work out better, but I don't quite
understand the use case for the string stream.

> +       if (!frag_container)
> +               return -ENOMEM;
> +
> +       frag_container->fragment = kmalloc(len, GFP_KERNEL);
> +       if (!frag_container->fragment) {
> +               kfree(frag_container);
> +               return -ENOMEM;
> +       }
> +
> +       len = vsnprintf(frag_container->fragment, len, fmt, args);
> +       spin_lock_irqsave(&stream->lock, flags);
> +       stream->length += len;
> +       list_add_tail(&frag_container->node, &stream->fragments);
> +       spin_unlock_irqrestore(&stream->lock, flags);
> +
> +       return 0;
> +}
> +
[...]
> +
> +bool string_stream_is_empty(struct string_stream *stream)
> +{
> +       bool is_empty;
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&stream->lock, flags);

I'm not sure what benefit grabbing the lock is having here. If the list
isn't empty after this is called then the race isn't resolved by
grabbing and releasing the lock. The function is returning stale data in
that case.

> +       is_empty = list_empty(&stream->fragments);
> +       spin_unlock_irqrestore(&stream->lock, flags);
> +
> +       return is_empty;
> +}
> +
> +static int string_stream_init(struct kunit_resource *res, void *context)
> +{
> +       struct string_stream *stream;
> +
> +       stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> +       if (!stream)
> +               return -ENOMEM;
> +
> +       res->allocation = stream;
> +       INIT_LIST_HEAD(&stream->fragments);
> +       spin_lock_init(&stream->lock);
> +
> +       return 0;
> +}
> +
> +static void string_stream_free(struct kunit_resource *res)
> +{
> +       struct string_stream *stream = res->allocation;
> +
> +       string_stream_clear(stream);
> +       kfree(stream);
> +}
> +
> +struct string_stream *alloc_string_stream(struct kunit *test)
> +{
> +       struct kunit_resource *res;
> +
> +       res = kunit_alloc_resource(test,
> +                                  string_stream_init,
> +                                  string_stream_free,
> +                                  NULL);
> +
> +       if (!res)
> +               return NULL;
> +
> +       return res->allocation;

Maybe kunit_alloc_resource() should just return res->allocation, or
NULL, so that these functions can be simplified to 'return
kunit_alloc_resource()'? Does the caller ever care to do anything with
struct kunit_resource anyway?


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 06/18] kbuild: enable building KUnit
  2019-07-12  8:17 ` [PATCH v9 06/18] kbuild: enable building KUnit Brendan Higgins
@ 2019-07-15 20:49   ` Stephen Boyd
  0 siblings, 0 replies; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 20:49 UTC (permalink / raw)
  To: Brendan Higgins, frowand.list, gregkh, jpoimboe, keescook,
	kieran.bingham, mcgrof, peterz, robh, shuah, tytso,
	yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins, Michal Marek

Quoting Brendan Higgins (2019-07-12 01:17:32)
> KUnit is a new unit testing framework for the kernel and when used is
> built into the kernel as a part of it. Add KUnit to the root Kconfig and
> Makefile to allow it to be actually built.
> 
> Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: Michal Marek <michal.lkml@markovi.net>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
> ---

Reviewed-by: Stephen Boyd <sboyd@kernel.org>


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 02/18] kunit: test: add test resource management API
  2019-07-15 20:30     ` Brendan Higgins
@ 2019-07-15 20:51       ` Stephen Boyd
  0 siblings, 0 replies; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 20:51 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-15 13:30:22)
> On Mon, Jul 15, 2019 at 1:24 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Brendan Higgins (2019-07-12 01:17:28)
> > > diff --git a/kunit/test.c b/kunit/test.c
> > > index 571e4c65deb5c..f165c9d8e10b0 100644
> 
> > One solution would be to piggyback on all the existing devres allocation
> > logic we already have and make each struct kunit a device that we pass
> > into the devres functions. A far simpler solution would be to just
> > copy/paste what devres does and use a spinlock and an allocation
> > function that takes GFP flags.
> 
> Yeah, that's what I did originally, but I thought from the discussion
> on patch 01 that you thought a spinlock was overkill for struct kunit.
> I take it you only meant in that initial patch?

Correct. I was only talking about the success bit in there.


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-15 20:43   ` Stephen Boyd
@ 2019-07-15 21:11     ` Brendan Higgins
  2019-07-15 22:04       ` Stephen Boyd
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-15 21:11 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 15, 2019 at 1:43 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-12 01:17:29)
> > diff --git a/include/kunit/string-stream.h b/include/kunit/string-stream.h
> > new file mode 100644
> > index 0000000000000..0552a05781afe
> > --- /dev/null
> > +++ b/include/kunit/string-stream.h
> > @@ -0,0 +1,49 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * C++ stream style string builder used in KUnit for building messages.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#ifndef _KUNIT_STRING_STREAM_H
> > +#define _KUNIT_STRING_STREAM_H
> > +
> > +#include <linux/types.h>
> > +#include <linux/spinlock.h>
> > +#include <linux/kref.h>
>
> What is this include for? I'd expect to see linux/list.h instead.

Sorry about that. I used to reference count this before I made it a
kunit managed resource.

> > +#include <stdarg.h>
> > +
> > +struct string_stream_fragment {
> > +       struct list_head node;
> > +       char *fragment;
> > +};
> > +
> > +struct string_stream {
> > +       size_t length;
> > +       struct list_head fragments;
> > +       /* length and fragments are protected by this lock */
> > +       spinlock_t lock;
> > +};
> > +
> > diff --git a/kunit/string-stream.c b/kunit/string-stream.c
> > new file mode 100644
> > index 0000000000000..0463a92dad74b
> > --- /dev/null
> > +++ b/kunit/string-stream.c
> > @@ -0,0 +1,147 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * C++ stream style string builder used in KUnit for building messages.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#include <linux/list.h>
> > +#include <linux/slab.h>
> > +#include <kunit/string-stream.h>
> > +#include <kunit/test.h>
> > +
> > +int string_stream_vadd(struct string_stream *stream,
> > +                      const char *fmt,
> > +                      va_list args)
> > +{
> > +       struct string_stream_fragment *frag_container;
> > +       int len;
> > +       va_list args_for_counting;
> > +       unsigned long flags;
> > +
> > +       /* Make a copy because `vsnprintf` could change it */
> > +       va_copy(args_for_counting, args);
> > +
> > +       /* Need space for null byte. */
> > +       len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
> > +
> > +       va_end(args_for_counting);
> > +
> > +       frag_container = kmalloc(sizeof(*frag_container), GFP_KERNEL);
>
> This is confusing in that it allocates with GFP_KERNEL but then grabs a
> spinlock to add and remove from the fragment list. Is it ever going to
> be called from a place where it can't sleep? If so, the GFP_KERNEL needs
> to be changed. Otherwise, maybe a mutex would work better to protect
> access to the fragment list.

Right, using a mutex here would be fine. Sorry, I meant to filter for
my usage of them after you asked me to remove them in 01, but
evidently I forgot to do so. Sorry, will fix.

> I also wonder if it would be better to just have a big slop buffer of a
> 4K page or something so that we almost never have to allocate anything
> with a string_stream and we can just rely on a reader consuming data
> while writers are writing. That might work out better, but I don't quite
> understand the use case for the string stream.

That makes sense, but might that also waste memory since we will
almost never need that much memory?

> > +       if (!frag_container)
> > +               return -ENOMEM;
> > +
> > +       frag_container->fragment = kmalloc(len, GFP_KERNEL);
> > +       if (!frag_container->fragment) {
> > +               kfree(frag_container);
> > +               return -ENOMEM;
> > +       }
> > +
> > +       len = vsnprintf(frag_container->fragment, len, fmt, args);
> > +       spin_lock_irqsave(&stream->lock, flags);
> > +       stream->length += len;
> > +       list_add_tail(&frag_container->node, &stream->fragments);
> > +       spin_unlock_irqrestore(&stream->lock, flags);
> > +
> > +       return 0;
> > +}
> > +
> [...]
> > +
> > +bool string_stream_is_empty(struct string_stream *stream)
> > +{
> > +       bool is_empty;
> > +       unsigned long flags;
> > +
> > +       spin_lock_irqsave(&stream->lock, flags);
>
> I'm not sure what benefit grabbing the lock is having here. If the list
> isn't empty after this is called then the race isn't resolved by
> grabbing and releasing the lock. The function is returning stale data in
> that case.

Good point, I didn't realize list_empty was protected by READ_ONCE. Will fix.

> > +       is_empty = list_empty(&stream->fragments);
> > +       spin_unlock_irqrestore(&stream->lock, flags);
> > +
> > +       return is_empty;
> > +}
> > +
> > +static int string_stream_init(struct kunit_resource *res, void *context)
> > +{
> > +       struct string_stream *stream;
> > +
> > +       stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> > +       if (!stream)
> > +               return -ENOMEM;
> > +
> > +       res->allocation = stream;
> > +       INIT_LIST_HEAD(&stream->fragments);
> > +       spin_lock_init(&stream->lock);
> > +
> > +       return 0;
> > +}
> > +
> > +static void string_stream_free(struct kunit_resource *res)
> > +{
> > +       struct string_stream *stream = res->allocation;
> > +
> > +       string_stream_clear(stream);
> > +       kfree(stream);
> > +}
> > +
> > +struct string_stream *alloc_string_stream(struct kunit *test)
> > +{
> > +       struct kunit_resource *res;
> > +
> > +       res = kunit_alloc_resource(test,
> > +                                  string_stream_init,
> > +                                  string_stream_free,
> > +                                  NULL);
> > +
> > +       if (!res)
> > +               return NULL;
> > +
> > +       return res->allocation;
>
> Maybe kunit_alloc_resource() should just return res->allocation, or
> NULL, so that these functions can be simplified to 'return
> kunit_alloc_resource()'? Does the caller ever care to do anything with
> struct kunit_resource anyway?

Another good point. I think originally I thought it might, but now
with the mandatory init function, the user has to provide a function
where they can do the init work. They might as well do it there. Will
fix.

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 01/18] kunit: test: add KUnit test runner core
  2019-07-15 20:10   ` Stephen Boyd
@ 2019-07-15 21:25     ` Brendan Higgins
  0 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-15 21:25 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 15, 2019 at 1:10 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-12 01:17:27)
> > Add core facilities for defining unit tests; this provides a common way
> > to define test cases, functions that execute code which is under test
> > and determine whether the code under test behaves as expected; this also
> > provides a way to group together related test cases in test suites (here
> > we call them test_modules).
> >
> > Just define test cases and how to execute them for now; setting
> > expectations on code will be defined later.
> >
> > Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
> > Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
> > Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
>
> Reviewed-by: Stephen Boyd <sboyd@kernel.org>
>
> Minor nits below.
>
> > diff --git a/kunit/test.c b/kunit/test.c
> > new file mode 100644
> > index 0000000000000..571e4c65deb5c
> > --- /dev/null
> > +++ b/kunit/test.c
> > @@ -0,0 +1,189 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Base unit test (KUnit) API.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <kunit/test.h>
> > +
> > +static void kunit_set_failure(struct kunit *test)
> > +{
> > +       WRITE_ONCE(test->success, false);
> > +}
> > +
> [...]
> > +
> > +void kunit_init_test(struct kunit *test, const char *name)
> > +{
> > +       test->name = name;
> > +       test->success = true;
> > +}
> > +
> > +/*
> > + * Performs all logic to run a test case.
> > + */
> > +static void kunit_run_case(struct kunit_suite *suite,
> > +                          struct kunit_case *test_case)
> > +{
> > +       struct kunit test;
> > +       int ret = 0;
> > +
> > +       kunit_init_test(&test, test_case->name);
> > +
> > +       if (suite->init) {
> > +               ret = suite->init(&test);
>
> Can you push the ret definition into this if scope? That way we can
> avoid default initialize to 0 for it.

Sure! I would actually prefer that from a cosmetic standpoint. I just
thought that mixing declarations and code was against the style guide.

> > +               if (ret) {
> > +                       kunit_err(&test, "failed to initialize: %d\n", ret);
> > +                       kunit_set_failure(&test);
>
> Do we need to 'test_case->success = test.success' here too? Or is the
> test failure extracted somewhere else?

Er, yes. That's kind of embarrassing. Good catch.

> > +                       return;
> > +               }
> > +       }
> > +
> > +       test_case->run_case(&test);
> > +
> > +       if (suite->exit)
> > +               suite->exit(&test);
> > +
> > +       test_case->success = test.success;

Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-15 21:11     ` Brendan Higgins
@ 2019-07-15 22:04       ` Stephen Boyd
  2019-07-15 22:11         ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 22:04 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-15 14:11:50)
> On Mon, Jul 15, 2019 at 1:43 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > I also wonder if it would be better to just have a big slop buffer of a
> > 4K page or something so that we almost never have to allocate anything
> > with a string_stream and we can just rely on a reader consuming data
> > while writers are writing. That might work out better, but I don't quite
> > understand the use case for the string stream.
> 
> That makes sense, but might that also waste memory since we will
> almost never need that much memory?

Why do we care? These are unit tests. Having allocations in here makes
things more complicated, whereas it would be simpler to have a pointer
and a spinlock operating on a chunk of memory that gets flushed out
periodically.


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-15 22:04       ` Stephen Boyd
@ 2019-07-15 22:11         ` Brendan Higgins
  2019-07-15 22:43           ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-15 22:11 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 15, 2019 at 3:04 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-15 14:11:50)
> > On Mon, Jul 15, 2019 at 1:43 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > I also wonder if it would be better to just have a big slop buffer of a
> > > 4K page or something so that we almost never have to allocate anything
> > > with a string_stream and we can just rely on a reader consuming data
> > > while writers are writing. That might work out better, but I don't quite
> > > understand the use case for the string stream.
> >
> > That makes sense, but might that also waste memory since we will
> > almost never need that much memory?
>
> Why do we care? These are unit tests.

Agreed.

> Having allocations in here makes
> things more complicated, whereas it would be simpler to have a pointer
> and a spinlock operating on a chunk of memory that gets flushed out
> periodically.

I am not so sure. I have to have the logic to allocate memory in some
case no matter what (what if I need more memory that my preallocated
chuck?). I think it is simpler to always request an allocation than to
only sometimes request an allocation.

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-12  8:17 ` [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger Brendan Higgins
@ 2019-07-15 22:15   ` Stephen Boyd
  2019-07-16  7:57     ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-15 22:15 UTC (permalink / raw)
  To: Brendan Higgins, frowand.list, gregkh, jpoimboe, keescook,
	kieran.bingham, mcgrof, peterz, robh, shuah, tytso,
	yamada.masahiro
  Cc: devicetree, dri-devel, kunit-dev, linux-doc, linux-fsdevel,
	linux-kbuild, linux-kernel, linux-kselftest, linux-nvdimm,
	linux-um, Alexander.Levin, Tim.Bird, amir73il, dan.carpenter,
	daniel, jdike, joel, julia.lawall, khilman, knut.omang, logang,
	mpe, pmladek, rdunlap, richard, rientjes, rostedt, wfg,
	Brendan Higgins

Quoting Brendan Higgins (2019-07-12 01:17:30)
> diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
> new file mode 100644
> index 0000000000000..a7b53eabf6be4
> --- /dev/null
> +++ b/include/kunit/kunit-stream.h
> @@ -0,0 +1,81 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * C++ stream style string formatter and printer used in KUnit for outputting
> + * KUnit messages.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#ifndef _KUNIT_KUNIT_STREAM_H
> +#define _KUNIT_KUNIT_STREAM_H
> +
> +#include <linux/types.h>
> +#include <kunit/string-stream.h>
> +
> +struct kunit;
> +
> +/**
> + * struct kunit_stream - a std::stream style string builder.
> + *
> + * A std::stream style string builder. Allows messages to be built up and
> + * printed all at once.
> + */
> +struct kunit_stream {
> +       /* private: internal use only. */
> +       struct kunit *test;
> +       const char *level;

Is the level changed? See my comment below, but I wonder if this whole
struct can go away and the wrappers can just operate on 'struct
string_stream' instead.

> +       struct string_stream *internal_stream;
> +};
> diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
> new file mode 100644
> index 0000000000000..8bea1f22eafb5
> --- /dev/null
> +++ b/kunit/kunit-stream.c
> @@ -0,0 +1,123 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * C++ stream style string formatter and printer used in KUnit for outputting
> + * KUnit messages.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#include <kunit/test.h>
> +#include <kunit/kunit-stream.h>
> +#include <kunit/string-stream.h>
> +
> +void kunit_stream_add(struct kunit_stream *kstream, const char *fmt, ...)
> +{
> +       va_list args;
> +       struct string_stream *stream = kstream->internal_stream;
> +
> +       va_start(args, fmt);
> +
> +       if (string_stream_vadd(stream, fmt, args) < 0)
> +               kunit_err(kstream->test,
> +                         "Failed to allocate fragment: %s\n",
> +                         fmt);
> +
> +       va_end(args);
> +}
> +
> +void kunit_stream_append(struct kunit_stream *kstream,
> +                               struct kunit_stream *other)
> +{
> +       struct string_stream *other_stream = other->internal_stream;
> +       const char *other_content;
> +
> +       other_content = string_stream_get_string(other_stream);
> +
> +       if (!other_content) {
> +               kunit_err(kstream->test,
> +                         "Failed to get string from second argument for appending\n");
> +               return;
> +       }
> +
> +       kunit_stream_add(kstream, other_content);
> +}

Why can't this function be implemented in the string_stream API? Seems
valid to want to append one stream to another and that isn't
kunit_stream specific.

> +
> +void kunit_stream_clear(struct kunit_stream *kstream)
> +{
> +       string_stream_clear(kstream->internal_stream);
> +}
> +
> +void kunit_stream_commit(struct kunit_stream *kstream)
> +{
> +       struct string_stream *stream = kstream->internal_stream;
> +       struct string_stream_fragment *fragment;
> +       struct kunit *test = kstream->test;
> +       char *buf;
> +
> +       buf = string_stream_get_string(stream);
> +       if (!buf) {
> +               kunit_err(test,
> +                         "Could not allocate buffer, dumping stream:\n");
> +               list_for_each_entry(fragment, &stream->fragments, node) {
> +                       kunit_err(test, fragment->fragment);
> +               }
> +               kunit_err(test, "\n");
> +               goto cleanup;
> +       }
> +
> +       kunit_printk(kstream->level, test, buf);
> +       kfree(buf);
> +
> +cleanup:

Drop the goto and use an 'else' please.

> +       kunit_stream_clear(kstream);
> +}
> +
> +static int kunit_stream_init(struct kunit_resource *res, void *context)
> +{
> +       struct kunit *test = context;
> +       struct kunit_stream *stream;
> +
> +       stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> +       if (!stream)
> +               return -ENOMEM;
> +
> +       res->allocation = stream;
> +       stream->test = test;
> +       stream->internal_stream = alloc_string_stream(test);
> +
> +       if (!stream->internal_stream)
> +               return -ENOMEM;
> +
> +       return 0;
> +}
> +
> +static void kunit_stream_free(struct kunit_resource *res)
> +{
> +       struct kunit_stream *stream = res->allocation;
> +
> +       if (!string_stream_is_empty(stream->internal_stream)) {
> +               kunit_err(stream->test,
> +                         "End of test case reached with uncommitted stream entries\n");
> +               kunit_stream_commit(stream);
> +       }
> +}
> +

Nitpick: Drop this extra newline.

> diff --git a/kunit/test.c b/kunit/test.c
> index f165c9d8e10b0..29edf34a89a37 100644
> --- a/kunit/test.c
> +++ b/kunit/test.c
> @@ -120,6 +120,12 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
>                               test_case->name);
>  }
>  
> +void kunit_fail(struct kunit *test, struct kunit_stream *stream)

Why doesn't 'struct kunit' have a 'struct kunit_stream' inside of it? It
seems that the two are highly related, to the point that it might just
make sense to have

	struct kunit {
		struct kunit_stream stream;
		...
	};

> +{
> +       kunit_set_failure(test);
> +       kunit_stream_commit(stream);

And then this function can just take a test and the stream can be
associated with the test directly. Use container_of() to get to the test
when the only pointer in hand is for the stream too.

> +}
> +
>  void kunit_init_test(struct kunit *test, const char *name)
>  {
>         mutex_init(&test->lock);

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-15 22:11         ` Brendan Higgins
@ 2019-07-15 22:43           ` Brendan Higgins
  2019-07-16 15:33             ` Stephen Boyd
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-15 22:43 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 15, 2019 at 3:11 PM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> On Mon, Jul 15, 2019 at 3:04 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Brendan Higgins (2019-07-15 14:11:50)
> > > On Mon, Jul 15, 2019 at 1:43 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > >
> > > > I also wonder if it would be better to just have a big slop buffer of a
> > > > 4K page or something so that we almost never have to allocate anything
> > > > with a string_stream and we can just rely on a reader consuming data
> > > > while writers are writing. That might work out better, but I don't quite
> > > > understand the use case for the string stream.
> > >
> > > That makes sense, but might that also waste memory since we will
> > > almost never need that much memory?
> >
> > Why do we care? These are unit tests.
>
> Agreed.
>
> > Having allocations in here makes
> > things more complicated, whereas it would be simpler to have a pointer
> > and a spinlock operating on a chunk of memory that gets flushed out
> > periodically.
>
> I am not so sure. I have to have the logic to allocate memory in some
> case no matter what (what if I need more memory that my preallocated
> chuck?). I think it is simpler to always request an allocation than to
> only sometimes request an allocation.

Another even simpler alternative might be to just allocate memory
using kunit_kmalloc as we need it and just let the kunit_resource code
handle cleaning it all up when the test case finishes.

What do you think?

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-15 22:15   ` Stephen Boyd
@ 2019-07-16  7:57     ` Brendan Higgins
  2019-07-16  8:37       ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-16  7:57 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 15, 2019 at 3:15 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-12 01:17:30)
> > diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
> > new file mode 100644
> > index 0000000000000..a7b53eabf6be4
> > --- /dev/null
> > +++ b/include/kunit/kunit-stream.h
> > @@ -0,0 +1,81 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * C++ stream style string formatter and printer used in KUnit for outputting
> > + * KUnit messages.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#ifndef _KUNIT_KUNIT_STREAM_H
> > +#define _KUNIT_KUNIT_STREAM_H
> > +
> > +#include <linux/types.h>
> > +#include <kunit/string-stream.h>
> > +
> > +struct kunit;
> > +
> > +/**
> > + * struct kunit_stream - a std::stream style string builder.
> > + *
> > + * A std::stream style string builder. Allows messages to be built up and
> > + * printed all at once.
> > + */
> > +struct kunit_stream {
> > +       /* private: internal use only. */
> > +       struct kunit *test;
> > +       const char *level;
>
> Is the level changed? See my comment below, but I wonder if this whole
> struct can go away and the wrappers can just operate on 'struct
> string_stream' instead.

I was inclined to agree with you when I first read your comment, but
then I thought about the case that someone wants to add in a debug
message (of which I currently have none). I think under most
circumstances a user of kunit_stream would likely want to pick a
default verbosity that maybe I should provide, but may still want
different verbosity levels.

The main reason I want to keep the types separate, string_stream vs.
kunit_stream, is that they are intended to be used differently.
string_stream is just a generic string builder. If you are using that,
you are expecting to see someone building the string at some point and
then doing something interesting with it. kunit_stream really tells
you specifically that KUnit is putting together a message to
communicate something to a user of KUnit. It is really used in a very
specific way, and I wouldn't want to generalize its usage beyond how
it is currently used. I think in order to preserve the author's
intention it adds clarity to keep the types separate regardless of how
similar they might be in reality.

> > +       struct string_stream *internal_stream;
> > +};
> > diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
> > new file mode 100644
> > index 0000000000000..8bea1f22eafb5
> > --- /dev/null
> > +++ b/kunit/kunit-stream.c
> > @@ -0,0 +1,123 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * C++ stream style string formatter and printer used in KUnit for outputting
> > + * KUnit messages.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#include <kunit/test.h>
> > +#include <kunit/kunit-stream.h>
> > +#include <kunit/string-stream.h>
> > +
> > +void kunit_stream_add(struct kunit_stream *kstream, const char *fmt, ...)
> > +{
> > +       va_list args;
> > +       struct string_stream *stream = kstream->internal_stream;
> > +
> > +       va_start(args, fmt);
> > +
> > +       if (string_stream_vadd(stream, fmt, args) < 0)
> > +               kunit_err(kstream->test,
> > +                         "Failed to allocate fragment: %s\n",
> > +                         fmt);
> > +
> > +       va_end(args);
> > +}
> > +
> > +void kunit_stream_append(struct kunit_stream *kstream,
> > +                               struct kunit_stream *other)
> > +{
> > +       struct string_stream *other_stream = other->internal_stream;
> > +       const char *other_content;
> > +
> > +       other_content = string_stream_get_string(other_stream);
> > +
> > +       if (!other_content) {
> > +               kunit_err(kstream->test,
> > +                         "Failed to get string from second argument for appending\n");
> > +               return;
> > +       }
> > +
> > +       kunit_stream_add(kstream, other_content);
> > +}
>
> Why can't this function be implemented in the string_stream API? Seems
> valid to want to append one stream to another and that isn't
> kunit_stream specific.

Fair point. Will do.

> > +
> > +void kunit_stream_clear(struct kunit_stream *kstream)
> > +{
> > +       string_stream_clear(kstream->internal_stream);
> > +}
> > +
> > +void kunit_stream_commit(struct kunit_stream *kstream)
> > +{
> > +       struct string_stream *stream = kstream->internal_stream;
> > +       struct string_stream_fragment *fragment;
> > +       struct kunit *test = kstream->test;
> > +       char *buf;
> > +
> > +       buf = string_stream_get_string(stream);
> > +       if (!buf) {
> > +               kunit_err(test,
> > +                         "Could not allocate buffer, dumping stream:\n");
> > +               list_for_each_entry(fragment, &stream->fragments, node) {
> > +                       kunit_err(test, fragment->fragment);
> > +               }
> > +               kunit_err(test, "\n");
> > +               goto cleanup;
> > +       }
> > +
> > +       kunit_printk(kstream->level, test, buf);
> > +       kfree(buf);
> > +
> > +cleanup:
>
> Drop the goto and use an 'else' please.

Will do.

> > +       kunit_stream_clear(kstream);
> > +}
> > +
> > +static int kunit_stream_init(struct kunit_resource *res, void *context)
> > +{
> > +       struct kunit *test = context;
> > +       struct kunit_stream *stream;
> > +
> > +       stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> > +       if (!stream)
> > +               return -ENOMEM;
> > +
> > +       res->allocation = stream;
> > +       stream->test = test;
> > +       stream->internal_stream = alloc_string_stream(test);
> > +
> > +       if (!stream->internal_stream)
> > +               return -ENOMEM;
> > +
> > +       return 0;
> > +}
> > +
> > +static void kunit_stream_free(struct kunit_resource *res)
> > +{
> > +       struct kunit_stream *stream = res->allocation;
> > +
> > +       if (!string_stream_is_empty(stream->internal_stream)) {
> > +               kunit_err(stream->test,
> > +                         "End of test case reached with uncommitted stream entries\n");
> > +               kunit_stream_commit(stream);
> > +       }
> > +}
> > +
>
> Nitpick: Drop this extra newline.

Oops, nice catch.

> > diff --git a/kunit/test.c b/kunit/test.c
> > index f165c9d8e10b0..29edf34a89a37 100644
> > --- a/kunit/test.c
> > +++ b/kunit/test.c
> > @@ -120,6 +120,12 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
> >                               test_case->name);
> >  }
> >
> > +void kunit_fail(struct kunit *test, struct kunit_stream *stream)
>
> Why doesn't 'struct kunit' have a 'struct kunit_stream' inside of it? It
> seems that the two are highly related, to the point that it might just
> make sense to have

A `struct kunit_stream` is usually associated with a message that is
being built up over time like maybe an expectation; it is meant to
capture the idea that we might want to send some information out to
the user pertaining to some thing 'X', but we aren't sure that we
actually want to send it until 'X' is complete, but do to the nature
of 'X' it is easier to start constructing the message before 'X' is
complete.

Consider a complicated expectation, there might be multiple conditions
that satisfy it and multiple conditions which could make it fail. As
we start exploring the input to the expectation we gain information
that we might want to share back with the user if the expectation were
to fail and we might get that information before we are actually sure
that the expectation does indeed fail.

When we first step into the expectation we immediately know the
function name, file name, and line number where we are called and
would want to put that information into any message we would send to
the user about this expectation. Next, we might want to check a
property of the input, it may or may not be enough information on its
own for the expectation to fail, but we want to share the result of
the property check with the user regardless, BUT only if the
expectation as a whole fails.

Hence, we can have multiple `struct kunit_stream`s associated with a
`struct kunit` active at any given time.

>         struct kunit {
>                 struct kunit_stream stream;
>                 ...
>         };
>
> > +{
> > +       kunit_set_failure(test);
> > +       kunit_stream_commit(stream);
>
> And then this function can just take a test and the stream can be
> associated with the test directly. Use container_of() to get to the test
> when the only pointer in hand is for the stream too.

Unfortunately that wouldn't work. See my above explanation.

> > +}
> > +
> >  void kunit_init_test(struct kunit *test, const char *name)
> >  {
> >         mutex_init(&test->lock);

Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-16  7:57     ` Brendan Higgins
@ 2019-07-16  8:37       ` Brendan Higgins
  2019-07-16 15:30         ` Stephen Boyd
  2019-07-16 17:50         ` Stephen Boyd
  0 siblings, 2 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-16  8:37 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Tue, Jul 16, 2019 at 12:57 AM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> On Mon, Jul 15, 2019 at 3:15 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Brendan Higgins (2019-07-12 01:17:30)
> > > diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
> > > new file mode 100644
> > > index 0000000000000..a7b53eabf6be4
> > > --- /dev/null
> > > +++ b/include/kunit/kunit-stream.h
> > > @@ -0,0 +1,81 @@
> > > +/* SPDX-License-Identifier: GPL-2.0 */
> > > +/*
> > > + * C++ stream style string formatter and printer used in KUnit for outputting
> > > + * KUnit messages.
> > > + *
> > > + * Copyright (C) 2019, Google LLC.
> > > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > > + */
> > > +
> > > +#ifndef _KUNIT_KUNIT_STREAM_H
> > > +#define _KUNIT_KUNIT_STREAM_H
> > > +
> > > +#include <linux/types.h>
> > > +#include <kunit/string-stream.h>
> > > +
> > > +struct kunit;
> > > +
> > > +/**
> > > + * struct kunit_stream - a std::stream style string builder.
> > > + *
> > > + * A std::stream style string builder. Allows messages to be built up and
> > > + * printed all at once.
> > > + */
> > > +struct kunit_stream {
> > > +       /* private: internal use only. */
> > > +       struct kunit *test;
> > > +       const char *level;
> >
> > Is the level changed? See my comment below, but I wonder if this whole
> > struct can go away and the wrappers can just operate on 'struct
> > string_stream' instead.
>
> I was inclined to agree with you when I first read your comment, but
> then I thought about the case that someone wants to add in a debug
> message (of which I currently have none). I think under most
> circumstances a user of kunit_stream would likely want to pick a
> default verbosity that maybe I should provide, but may still want
> different verbosity levels.
>
> The main reason I want to keep the types separate, string_stream vs.
> kunit_stream, is that they are intended to be used differently.
> string_stream is just a generic string builder. If you are using that,
> you are expecting to see someone building the string at some point and
> then doing something interesting with it. kunit_stream really tells
> you specifically that KUnit is putting together a message to
> communicate something to a user of KUnit. It is really used in a very
> specific way, and I wouldn't want to generalize its usage beyond how
> it is currently used. I think in order to preserve the author's
> intention it adds clarity to keep the types separate regardless of how
> similar they might be in reality.
>
> > > +       struct string_stream *internal_stream;
> > > +};
> > > diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
> > > new file mode 100644
> > > index 0000000000000..8bea1f22eafb5
> > > --- /dev/null
> > > +++ b/kunit/kunit-stream.c
> > > @@ -0,0 +1,123 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/*
> > > + * C++ stream style string formatter and printer used in KUnit for outputting
> > > + * KUnit messages.
> > > + *
> > > + * Copyright (C) 2019, Google LLC.
> > > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > > + */
> > > +
> > > +#include <kunit/test.h>
> > > +#include <kunit/kunit-stream.h>
> > > +#include <kunit/string-stream.h>
> > > +
> > > +void kunit_stream_add(struct kunit_stream *kstream, const char *fmt, ...)
> > > +{
> > > +       va_list args;
> > > +       struct string_stream *stream = kstream->internal_stream;
> > > +
> > > +       va_start(args, fmt);
> > > +
> > > +       if (string_stream_vadd(stream, fmt, args) < 0)
> > > +               kunit_err(kstream->test,
> > > +                         "Failed to allocate fragment: %s\n",
> > > +                         fmt);
> > > +
> > > +       va_end(args);
> > > +}
> > > +
> > > +void kunit_stream_append(struct kunit_stream *kstream,
> > > +                               struct kunit_stream *other)
> > > +{
> > > +       struct string_stream *other_stream = other->internal_stream;
> > > +       const char *other_content;
> > > +
> > > +       other_content = string_stream_get_string(other_stream);
> > > +
> > > +       if (!other_content) {
> > > +               kunit_err(kstream->test,
> > > +                         "Failed to get string from second argument for appending\n");
> > > +               return;
> > > +       }
> > > +
> > > +       kunit_stream_add(kstream, other_content);
> > > +}
> >
> > Why can't this function be implemented in the string_stream API? Seems
> > valid to want to append one stream to another and that isn't
> > kunit_stream specific.
>
> Fair point. Will do.
>
> > > +
> > > +void kunit_stream_clear(struct kunit_stream *kstream)
> > > +{
> > > +       string_stream_clear(kstream->internal_stream);
> > > +}
> > > +
> > > +void kunit_stream_commit(struct kunit_stream *kstream)
> > > +{
> > > +       struct string_stream *stream = kstream->internal_stream;
> > > +       struct string_stream_fragment *fragment;
> > > +       struct kunit *test = kstream->test;
> > > +       char *buf;
> > > +
> > > +       buf = string_stream_get_string(stream);
> > > +       if (!buf) {
> > > +               kunit_err(test,
> > > +                         "Could not allocate buffer, dumping stream:\n");
> > > +               list_for_each_entry(fragment, &stream->fragments, node) {
> > > +                       kunit_err(test, fragment->fragment);
> > > +               }
> > > +               kunit_err(test, "\n");
> > > +               goto cleanup;
> > > +       }
> > > +
> > > +       kunit_printk(kstream->level, test, buf);
> > > +       kfree(buf);
> > > +
> > > +cleanup:
> >
> > Drop the goto and use an 'else' please.
>
> Will do.
>
> > > +       kunit_stream_clear(kstream);
> > > +}
> > > +
> > > +static int kunit_stream_init(struct kunit_resource *res, void *context)
> > > +{
> > > +       struct kunit *test = context;
> > > +       struct kunit_stream *stream;
> > > +
> > > +       stream = kzalloc(sizeof(*stream), GFP_KERNEL);
> > > +       if (!stream)
> > > +               return -ENOMEM;
> > > +
> > > +       res->allocation = stream;
> > > +       stream->test = test;
> > > +       stream->internal_stream = alloc_string_stream(test);
> > > +
> > > +       if (!stream->internal_stream)
> > > +               return -ENOMEM;
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +static void kunit_stream_free(struct kunit_resource *res)
> > > +{
> > > +       struct kunit_stream *stream = res->allocation;
> > > +
> > > +       if (!string_stream_is_empty(stream->internal_stream)) {
> > > +               kunit_err(stream->test,
> > > +                         "End of test case reached with uncommitted stream entries\n");
> > > +               kunit_stream_commit(stream);
> > > +       }
> > > +}
> > > +
> >
> > Nitpick: Drop this extra newline.
>
> Oops, nice catch.

Not super important, but I don't want you to think that I am ignoring
you. I think you must have unintentionally deleted the last function
in this file, or maybe you are referring to something that I am just
not seeing, but I don't see the extra newline here.

> > > diff --git a/kunit/test.c b/kunit/test.c
> > > index f165c9d8e10b0..29edf34a89a37 100644
> > > --- a/kunit/test.c
> > > +++ b/kunit/test.c
> > > @@ -120,6 +120,12 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
> > >                               test_case->name);
> > >  }
> > >
> > > +void kunit_fail(struct kunit *test, struct kunit_stream *stream)
> >
> > Why doesn't 'struct kunit' have a 'struct kunit_stream' inside of it? It
> > seems that the two are highly related, to the point that it might just
> > make sense to have
>
> A `struct kunit_stream` is usually associated with a message that is
> being built up over time like maybe an expectation; it is meant to
> capture the idea that we might want to send some information out to
> the user pertaining to some thing 'X', but we aren't sure that we
> actually want to send it until 'X' is complete, but do to the nature
> of 'X' it is easier to start constructing the message before 'X' is
> complete.
>
> Consider a complicated expectation, there might be multiple conditions
> that satisfy it and multiple conditions which could make it fail. As
> we start exploring the input to the expectation we gain information
> that we might want to share back with the user if the expectation were
> to fail and we might get that information before we are actually sure
> that the expectation does indeed fail.
>
> When we first step into the expectation we immediately know the
> function name, file name, and line number where we are called and
> would want to put that information into any message we would send to
> the user about this expectation. Next, we might want to check a
> property of the input, it may or may not be enough information on its
> own for the expectation to fail, but we want to share the result of
> the property check with the user regardless, BUT only if the
> expectation as a whole fails.
>
> Hence, we can have multiple `struct kunit_stream`s associated with a
> `struct kunit` active at any given time.
>
> >         struct kunit {
> >                 struct kunit_stream stream;
> >                 ...
> >         };
> >
> > > +{
> > > +       kunit_set_failure(test);
> > > +       kunit_stream_commit(stream);
> >
> > And then this function can just take a test and the stream can be
> > associated with the test directly. Use container_of() to get to the test
> > when the only pointer in hand is for the stream too.
>
> Unfortunately that wouldn't work. See my above explanation.
>
> > > +}
> > > +
> > >  void kunit_init_test(struct kunit *test, const char *name)
> > >  {
> > >         mutex_init(&test->lock);
>
> Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-16  8:37       ` Brendan Higgins
@ 2019-07-16 15:30         ` Stephen Boyd
  2019-07-16 17:51           ` Brendan Higgins
  2019-07-16 17:50         ` Stephen Boyd
  1 sibling, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-16 15:30 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-16 01:37:34)
> On Tue, Jul 16, 2019 at 12:57 AM Brendan Higgins
> <brendanhiggins@google.com> wrote:
> >
> > On Mon, Jul 15, 2019 at 3:15 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Brendan Higgins (2019-07-12 01:17:30)
> > > > diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
> > > > new file mode 100644
> > > > index 0000000000000..a7b53eabf6be4
> > > > --- /dev/null
> > > > +++ b/include/kunit/kunit-stream.h
> > > > +/**
> > > > + * struct kunit_stream - a std::stream style string builder.
> > > > + *
> > > > + * A std::stream style string builder. Allows messages to be built up and
> > > > + * printed all at once.
> > > > + */
> > > > +struct kunit_stream {
> > > > +       /* private: internal use only. */
> > > > +       struct kunit *test;
> > > > +       const char *level;
> > >
> > > Is the level changed? See my comment below, but I wonder if this whole
> > > struct can go away and the wrappers can just operate on 'struct
> > > string_stream' instead.
> >
> > I was inclined to agree with you when I first read your comment, but
> > then I thought about the case that someone wants to add in a debug
> > message (of which I currently have none). I think under most
> > circumstances a user of kunit_stream would likely want to pick a
> > default verbosity that maybe I should provide, but may still want
> > different verbosity levels.
> >
> > The main reason I want to keep the types separate, string_stream vs.
> > kunit_stream, is that they are intended to be used differently.
> > string_stream is just a generic string builder. If you are using that,
> > you are expecting to see someone building the string at some point and
> > then doing something interesting with it. kunit_stream really tells
> > you specifically that KUnit is putting together a message to
> > communicate something to a user of KUnit. It is really used in a very
> > specific way, and I wouldn't want to generalize its usage beyond how
> > it is currently used. I think in order to preserve the author's
> > intention it adds clarity to keep the types separate regardless of how
> > similar they might be in reality.

You may want to add some of these reasons to the commit text.

> > > > +
> > > > +       if (!string_stream_is_empty(stream->internal_stream)) {
> > > > +               kunit_err(stream->test,
> > > > +                         "End of test case reached with uncommitted stream entries\n");
> > > > +               kunit_stream_commit(stream);
> > > > +       }
> > > > +}
> > > > +
> > >
> > > Nitpick: Drop this extra newline.
> >
> > Oops, nice catch.
> 
> Not super important, but I don't want you to think that I am ignoring
> you. I think you must have unintentionally deleted the last function
> in this file, or maybe you are referring to something that I am just
> not seeing, but I don't see the extra newline here.

No worries. Sorry for the noise.

> > property of the input, it may or may not be enough information on its
> > own for the expectation to fail, but we want to share the result of
> > the property check with the user regardless, BUT only if the
> > expectation as a whole fails.
> >
> > Hence, we can have multiple `struct kunit_stream`s associated with a
> > `struct kunit` active at any given time.

Makes sense. I wasn't sure if there were more than one stream associated
with a test. Sounds like there are many to one so it can't just be a
member of the test. This could be documented somewhere so this question
doesn't come up again.


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-15 22:43           ` Brendan Higgins
@ 2019-07-16 15:33             ` Stephen Boyd
  2019-07-16 18:55               ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-16 15:33 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-15 15:43:20)
> On Mon, Jul 15, 2019 at 3:11 PM Brendan Higgins
> <brendanhiggins@google.com> wrote:
> >
> > On Mon, Jul 15, 2019 at 3:04 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Brendan Higgins (2019-07-15 14:11:50)
> > > > On Mon, Jul 15, 2019 at 1:43 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > > >
> > > > > I also wonder if it would be better to just have a big slop buffer of a
> > > > > 4K page or something so that we almost never have to allocate anything
> > > > > with a string_stream and we can just rely on a reader consuming data
> > > > > while writers are writing. That might work out better, but I don't quite
> > > > > understand the use case for the string stream.
> > > >
> > > > That makes sense, but might that also waste memory since we will
> > > > almost never need that much memory?
> > >
> > > Why do we care? These are unit tests.
> >
> > Agreed.
> >
> > > Having allocations in here makes
> > > things more complicated, whereas it would be simpler to have a pointer
> > > and a spinlock operating on a chunk of memory that gets flushed out
> > > periodically.
> >
> > I am not so sure. I have to have the logic to allocate memory in some
> > case no matter what (what if I need more memory that my preallocated
> > chuck?). I think it is simpler to always request an allocation than to
> > only sometimes request an allocation.
> 
> Another even simpler alternative might be to just allocate memory
> using kunit_kmalloc as we need it and just let the kunit_resource code
> handle cleaning it all up when the test case finishes.

Sure, sounds like a nice way to avoid duplicating similar logic to
maintain a list of things to free later.

> 
> What do you think?

If you go the allocation route then you'll need to have the flags to
know what context you're in to allocate appropriately. Does that mean
all the string operations will now take GFP flags?


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-16  8:37       ` Brendan Higgins
  2019-07-16 15:30         ` Stephen Boyd
@ 2019-07-16 17:50         ` Stephen Boyd
  2019-07-16 18:52           ` Brendan Higgins
  1 sibling, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-16 17:50 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-16 01:37:34)
> On Tue, Jul 16, 2019 at 12:57 AM Brendan Higgins
> <brendanhiggins@google.com> wrote:
> >
> > A `struct kunit_stream` is usually associated with a message that is
> > being built up over time like maybe an expectation; it is meant to
> > capture the idea that we might want to send some information out to
> > the user pertaining to some thing 'X', but we aren't sure that we
> > actually want to send it until 'X' is complete, but do to the nature
> > of 'X' it is easier to start constructing the message before 'X' is
> > complete.
> >
> > Consider a complicated expectation, there might be multiple conditions
> > that satisfy it and multiple conditions which could make it fail. As
> > we start exploring the input to the expectation we gain information
> > that we might want to share back with the user if the expectation were
> > to fail and we might get that information before we are actually sure
> > that the expectation does indeed fail.
> >
> > When we first step into the expectation we immediately know the
> > function name, file name, and line number where we are called and
> > would want to put that information into any message we would send to
> > the user about this expectation. Next, we might want to check a
> > property of the input, it may or may not be enough information on its
> > own for the expectation to fail, but we want to share the result of
> > the property check with the user regardless, BUT only if the
> > expectation as a whole fails.
> >
> > Hence, we can have multiple `struct kunit_stream`s associated with a
> > `struct kunit` active at any given time.

I'm coming back to this now after reading the rest of the patches that
deal with assertions and expectations. It looks like the string stream
is there to hold a few different pieces of information:

 - Line Number
 - File Name
 - Function Name

The above items could be stored in a structure on the stack that then
gets printed and formatted when the expectation or assertion fails. That
would make the whole string stream structure and code unnecessary.

The only hypothetical case where this can't be done is a complicated
assertion or expectation that does more than one check and can't be
written as a function that dumps out what went wrong. Is this a real
problem? Maybe such an assertion should just open code that logic so we
don't have to build up a string for all the other simple cases.

It seems far simpler to get rid of the string stream API and just have a
struct for this.

	struct kunit_fail_msg {
		const char *line;
		const char *file;
		const char *func;
		const char *msg;
	};

Then you can have the assertion macros create this on the stack (with
another macro?).

	#define DEFINE_KUNIT_FAIL_MSG(name, _msg) \
		struct kunit_fail_msg name = { \
			.line =  __LINE__, \
			.file = __FILE__, \
			.func = __func__, \
			.msg = _msg, \
		}

Note: I don't know if the __LINE__ above will use the macro location, so
this probably needs another wrapper to put the right line number there.

I don't want to derail this whole series on this topic, but it seems
like a bunch of code is there to construct this same set of information
over and over again into a buffer a little bit at a time and then throw
it away when nothing fails just because we may want to support the case
where we have some unstructured data to inform the user about.

Why not build in the structured part into the framework (i.e. the struct
above) so that it's always there and then add the string building part
later when we have to?


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-16 15:30         ` Stephen Boyd
@ 2019-07-16 17:51           ` Brendan Higgins
  0 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-16 17:51 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Tue, Jul 16, 2019 at 8:30 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-16 01:37:34)
> > On Tue, Jul 16, 2019 at 12:57 AM Brendan Higgins
> > <brendanhiggins@google.com> wrote:
> > >
> > > On Mon, Jul 15, 2019 at 3:15 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > >
> > > > Quoting Brendan Higgins (2019-07-12 01:17:30)
> > > > > diff --git a/include/kunit/kunit-stream.h b/include/kunit/kunit-stream.h
> > > > > new file mode 100644
> > > > > index 0000000000000..a7b53eabf6be4
> > > > > --- /dev/null
> > > > > +++ b/include/kunit/kunit-stream.h
> > > > > +/**
> > > > > + * struct kunit_stream - a std::stream style string builder.
> > > > > + *
> > > > > + * A std::stream style string builder. Allows messages to be built up and
> > > > > + * printed all at once.
> > > > > + */
> > > > > +struct kunit_stream {
> > > > > +       /* private: internal use only. */
> > > > > +       struct kunit *test;
> > > > > +       const char *level;
> > > >
> > > > Is the level changed? See my comment below, but I wonder if this whole
> > > > struct can go away and the wrappers can just operate on 'struct
> > > > string_stream' instead.
> > >
> > > I was inclined to agree with you when I first read your comment, but
> > > then I thought about the case that someone wants to add in a debug
> > > message (of which I currently have none). I think under most
> > > circumstances a user of kunit_stream would likely want to pick a
> > > default verbosity that maybe I should provide, but may still want
> > > different verbosity levels.
> > >
> > > The main reason I want to keep the types separate, string_stream vs.
> > > kunit_stream, is that they are intended to be used differently.
> > > string_stream is just a generic string builder. If you are using that,
> > > you are expecting to see someone building the string at some point and
> > > then doing something interesting with it. kunit_stream really tells
> > > you specifically that KUnit is putting together a message to
> > > communicate something to a user of KUnit. It is really used in a very
> > > specific way, and I wouldn't want to generalize its usage beyond how
> > > it is currently used. I think in order to preserve the author's
> > > intention it adds clarity to keep the types separate regardless of how
> > > similar they might be in reality.
>
> You may want to add some of these reasons to the commit text.

Will do.

> > > > > +
> > > > > +       if (!string_stream_is_empty(stream->internal_stream)) {
> > > > > +               kunit_err(stream->test,
> > > > > +                         "End of test case reached with uncommitted stream entries\n");
> > > > > +               kunit_stream_commit(stream);
> > > > > +       }
> > > > > +}
> > > > > +
> > > >
> > > > Nitpick: Drop this extra newline.
> > >
> > > Oops, nice catch.
> >
> > Not super important, but I don't want you to think that I am ignoring
> > you. I think you must have unintentionally deleted the last function
> > in this file, or maybe you are referring to something that I am just
> > not seeing, but I don't see the extra newline here.
>
> No worries. Sorry for the noise.
>
> > > property of the input, it may or may not be enough information on its
> > > own for the expectation to fail, but we want to share the result of
> > > the property check with the user regardless, BUT only if the
> > > expectation as a whole fails.
> > >
> > > Hence, we can have multiple `struct kunit_stream`s associated with a
> > > `struct kunit` active at any given time.
>
> Makes sense. I wasn't sure if there were more than one stream associated
> with a test. Sounds like there are many to one so it can't just be a
> member of the test. This could be documented somewhere so this question
> doesn't come up again.

Sounds good. Will do.

Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-16 17:50         ` Stephen Boyd
@ 2019-07-16 18:52           ` Brendan Higgins
  2019-07-18 17:50             ` Stephen Boyd
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-16 18:52 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Tue, Jul 16, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-16 01:37:34)
> > On Tue, Jul 16, 2019 at 12:57 AM Brendan Higgins
> > <brendanhiggins@google.com> wrote:
> > >
> > > A `struct kunit_stream` is usually associated with a message that is
> > > being built up over time like maybe an expectation; it is meant to
> > > capture the idea that we might want to send some information out to
> > > the user pertaining to some thing 'X', but we aren't sure that we
> > > actually want to send it until 'X' is complete, but do to the nature
> > > of 'X' it is easier to start constructing the message before 'X' is
> > > complete.
> > >
> > > Consider a complicated expectation, there might be multiple conditions
> > > that satisfy it and multiple conditions which could make it fail. As
> > > we start exploring the input to the expectation we gain information
> > > that we might want to share back with the user if the expectation were
> > > to fail and we might get that information before we are actually sure
> > > that the expectation does indeed fail.
> > >
> > > When we first step into the expectation we immediately know the
> > > function name, file name, and line number where we are called and
> > > would want to put that information into any message we would send to
> > > the user about this expectation. Next, we might want to check a
> > > property of the input, it may or may not be enough information on its
> > > own for the expectation to fail, but we want to share the result of
> > > the property check with the user regardless, BUT only if the
> > > expectation as a whole fails.
> > >
> > > Hence, we can have multiple `struct kunit_stream`s associated with a
> > > `struct kunit` active at any given time.
>
> I'm coming back to this now after reading the rest of the patches that
> deal with assertions and expectations. It looks like the string stream
> is there to hold a few different pieces of information:
>
>  - Line Number
>  - File Name
>  - Function Name
>
> The above items could be stored in a structure on the stack that then
> gets printed and formatted when the expectation or assertion fails. That
> would make the whole string stream structure and code unnecessary.

Most of the expectations and assertions in this patchset are fairly
simple, and what you are describing would probably work. However, I
have some expectations I plan on adding in later patchsets that make
much more complicated checks.

> The only hypothetical case where this can't be done is a complicated
> assertion or expectation that does more than one check and can't be
> written as a function that dumps out what went wrong. Is this a real
> problem? Maybe such an assertion should just open code that logic so we
> don't have to build up a string for all the other simple cases.

I have some expectations in follow up patchsets for which I created a
set of composable matchers for matching structures and function calls
that by their nature cannot be written as a single function. The
matcher thing is a bit speculative, I know, but for any kind of
function call matching, you need to store a record of functions you
are expecting to have called and then each one needs to have a set of
expectations defined by the user; I don't think there is a way to do
that that doesn't involve having multiple separate functions each
having some information useful to constructing the message.

I know the code in question isn't in this patchset; the function
matching code was in one of the earlier versions of the RFC, but I
dropped it to make this patchset smaller and more manageable. So I get
it if you would like me to drop it and add it back in when I try to
get the function and structure matching stuff in, but I would really
prefer to keep it as is if you don't care too much.

> It seems far simpler to get rid of the string stream API and just have a
> struct for this.
>
>         struct kunit_fail_msg {
>                 const char *line;
>                 const char *file;
>                 const char *func;
>                 const char *msg;
>         };
>
> Then you can have the assertion macros create this on the stack (with
> another macro?).
>
>         #define DEFINE_KUNIT_FAIL_MSG(name, _msg) \
>                 struct kunit_fail_msg name = { \
>                         .line =  __LINE__, \
>                         .file = __FILE__, \
>                         .func = __func__, \
>                         .msg = _msg, \
>                 }
>
> Note: I don't know if the __LINE__ above will use the macro location, so
> this probably needs another wrapper to put the right line number there.

No, that should work. It picks up where the macro ends up being
finally evaluated.

> I don't want to derail this whole series on this topic, but it seems
> like a bunch of code is there to construct this same set of information
> over and over again into a buffer a little bit at a time and then throw
> it away when nothing fails just because we may want to support the case
> where we have some unstructured data to inform the user about.

Yeah, that's fair. I think there are a number of improvements to be
made with how the expectations are defined other than that, but I was
hoping I could do that after this patchset is merged. I just figured
with the kinds of things I would like to do, it would lead to a whole
new round of discussion.

In either case, I think I would still like to use the `struct
kunit_stream` as part of the interface to share the failure message
with the test case runner code in test.c, at least eventually, so that
I only have to have one way to receive data from expectations, but I
think I can do that and still do what you suggest by just constructing
the kunit_stream at the end of expectations where it is feasible.

All in all I agree with what you are saying, but I would rather do it
as a follow up possibly once we have some more code on the table. I
could just see this opening up a whole new can of worms where we
debate about exactly how expectations and assertions work for another
several months, only to rip it all out shortly there after. I know
that's how these things go, but that's my preference.

I can do what you suggest if you feel strongly about it, but I would
prefer to hold off until later. It's your call.

> Why not build in the structured part into the framework (i.e. the struct
> above) so that it's always there and then add the string building part
> later when we have to?

See above comments.

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder
  2019-07-16 15:33             ` Stephen Boyd
@ 2019-07-16 18:55               ` Brendan Higgins
  0 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-16 18:55 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Tue, Jul 16, 2019 at 8:34 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-15 15:43:20)
> > On Mon, Jul 15, 2019 at 3:11 PM Brendan Higgins
> > <brendanhiggins@google.com> wrote:
> > >
> > > On Mon, Jul 15, 2019 at 3:04 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > >
> > > > Quoting Brendan Higgins (2019-07-15 14:11:50)
> > > > > On Mon, Jul 15, 2019 at 1:43 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > > > >
> > > > > > I also wonder if it would be better to just have a big slop buffer of a
> > > > > > 4K page or something so that we almost never have to allocate anything
> > > > > > with a string_stream and we can just rely on a reader consuming data
> > > > > > while writers are writing. That might work out better, but I don't quite
> > > > > > understand the use case for the string stream.
> > > > >
> > > > > That makes sense, but might that also waste memory since we will
> > > > > almost never need that much memory?
> > > >
> > > > Why do we care? These are unit tests.
> > >
> > > Agreed.
> > >
> > > > Having allocations in here makes
> > > > things more complicated, whereas it would be simpler to have a pointer
> > > > and a spinlock operating on a chunk of memory that gets flushed out
> > > > periodically.
> > >
> > > I am not so sure. I have to have the logic to allocate memory in some
> > > case no matter what (what if I need more memory that my preallocated
> > > chuck?). I think it is simpler to always request an allocation than to
> > > only sometimes request an allocation.
> >
> > Another even simpler alternative might be to just allocate memory
> > using kunit_kmalloc as we need it and just let the kunit_resource code
> > handle cleaning it all up when the test case finishes.
>
> Sure, sounds like a nice way to avoid duplicating similar logic to
> maintain a list of things to free later.

I think I will go that route for now.

> >
> > What do you think?
>
> If you go the allocation route then you'll need to have the flags to
> know what context you're in to allocate appropriately. Does that mean
> all the string operations will now take GFP flags?

We could set the GFP flags in the constructor, store them in a field,
and then just reuse them.

Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-16 18:52           ` Brendan Higgins
@ 2019-07-18 17:50             ` Stephen Boyd
  2019-07-18 19:22               ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-18 17:50 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-16 11:52:01)
> On Tue, Jul 16, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> 
> > The only hypothetical case where this can't be done is a complicated
> > assertion or expectation that does more than one check and can't be
> > written as a function that dumps out what went wrong. Is this a real
> > problem? Maybe such an assertion should just open code that logic so we
> > don't have to build up a string for all the other simple cases.
> 
> I have some expectations in follow up patchsets for which I created a
> set of composable matchers for matching structures and function calls
> that by their nature cannot be written as a single function. The
> matcher thing is a bit speculative, I know, but for any kind of
> function call matching, you need to store a record of functions you
> are expecting to have called and then each one needs to have a set of
> expectations defined by the user; I don't think there is a way to do
> that that doesn't involve having multiple separate functions each
> having some information useful to constructing the message.
> 
> I know the code in question isn't in this patchset; the function
> matching code was in one of the earlier versions of the RFC, but I
> dropped it to make this patchset smaller and more manageable. So I get
> it if you would like me to drop it and add it back in when I try to
> get the function and structure matching stuff in, but I would really
> prefer to keep it as is if you don't care too much.

Do you have a link to those earlier patches?

> 
> > It seems far simpler to get rid of the string stream API and just have a
> > struct for this.
> >
> >         struct kunit_fail_msg {
> >                 const char *line;
> >                 const char *file;
> >                 const char *func;
> >                 const char *msg;
> >         };
> >
> > Then you can have the assertion macros create this on the stack (with
> > another macro?).
> >
> >         #define DEFINE_KUNIT_FAIL_MSG(name, _msg) \
> >                 struct kunit_fail_msg name = { \
> >                         .line =  __LINE__, \
> >                         .file = __FILE__, \
> >                         .func = __func__, \
> >                         .msg = _msg, \
> >                 }
> >
> > I don't want to derail this whole series on this topic, but it seems
> > like a bunch of code is there to construct this same set of information
> > over and over again into a buffer a little bit at a time and then throw
> > it away when nothing fails just because we may want to support the case
> > where we have some unstructured data to inform the user about.
> 
> Yeah, that's fair. I think there are a number of improvements to be
> made with how the expectations are defined other than that, but I was
> hoping I could do that after this patchset is merged. I just figured
> with the kinds of things I would like to do, it would lead to a whole
> new round of discussion.
> 
> In either case, I think I would still like to use the `struct
> kunit_stream` as part of the interface to share the failure message
> with the test case runner code in test.c, at least eventually, so that
> I only have to have one way to receive data from expectations, but I
> think I can do that and still do what you suggest by just constructing
> the kunit_stream at the end of expectations where it is feasible.
> 
> All in all I agree with what you are saying, but I would rather do it
> as a follow up possibly once we have some more code on the table. I
> could just see this opening up a whole new can of worms where we
> debate about exactly how expectations and assertions work for another
> several months, only to rip it all out shortly there after. I know
> that's how these things go, but that's my preference.
> 
> I can do what you suggest if you feel strongly about it, but I would
> prefer to hold off until later. It's your call.
> 

The crux of my complaint is that the string stream API is too loosely
defined to be usable. It allows tests to build up a string of
unstructured information, but with certain calling constraints so we
have to tread carefully. If there was more structure to the data that's
being recorded then the test case runner could operate on the data
without having to do string/stream operations, allocations, etc. This
would make the assertion logic much more concrete and specific to kunit,
instead of this small kunit wrapper that's been placed on top of string
stream.

TL;DR: If we can get rid of the string stream API I'd view that as an
improvement because building arbitrary strings in the kernel is complex,
error prone and has calling context concerns.

Is the intention that other code besides unit tests will use this string
stream API to build up strings? Any targets in mind? This would be a
good way to get the API merged upstream given that its 2019 and we
haven't had such an API in the kernel so far.

An "object oriented" (strong quotes!) approach where kunit_fail_msg is
the innermost struct in some assertion specific structure might work
nicely and allow the test runner to call a generic 'format' function to
print out the message based on the type of assertion/expectation it is.
It probably would mean less code size too because the strings that are
common will be in the common printing function instead of created twice,
in the macros/code and then copied to the heap for the string stream.

	struct kunit_assert {
		const char *line;
		const char *file;
		const char *func;
		void (*format)(struct kunit_assert *assert);
	};

	struct kunit_comparison_assert {
		enum operator operator;
		const char *left;
		const char *right;
		struct kunit_assert assert;
	};

	struct kunit_bool_assert {
		const char *truth;
		const char *statement;
		struct kunit_assert assert;
	};

	void kunit_format_comparison(struct kunit_assert *assert)
	{
		struct kunit_comparison_assert *comp = container_of(assert, ...)

		kunit_printk(...)
	}

Maybe other people have opinions here on if you should do it now or
later. Future coding is not a great argument because it's hard to
predict the future. On the other hand, this patchset is in good shape to
merge and I'd like to use it to write unit tests for code I maintain so
I don't want to see this stall out. Sorry if I'm opening the can of
worms you're talking about.


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-18 17:50             ` Stephen Boyd
@ 2019-07-18 19:22               ` Brendan Higgins
  2019-07-19  0:08                 ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-18 19:22 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Thu, Jul 18, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-16 11:52:01)
> > On Tue, Jul 16, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> >
> > > The only hypothetical case where this can't be done is a complicated
> > > assertion or expectation that does more than one check and can't be
> > > written as a function that dumps out what went wrong. Is this a real
> > > problem? Maybe such an assertion should just open code that logic so we
> > > don't have to build up a string for all the other simple cases.
> >
> > I have some expectations in follow up patchsets for which I created a
> > set of composable matchers for matching structures and function calls
> > that by their nature cannot be written as a single function. The
> > matcher thing is a bit speculative, I know, but for any kind of
> > function call matching, you need to store a record of functions you
> > are expecting to have called and then each one needs to have a set of
> > expectations defined by the user; I don't think there is a way to do
> > that that doesn't involve having multiple separate functions each
> > having some information useful to constructing the message.
> >
> > I know the code in question isn't in this patchset; the function
> > matching code was in one of the earlier versions of the RFC, but I
> > dropped it to make this patchset smaller and more manageable. So I get
> > it if you would like me to drop it and add it back in when I try to
> > get the function and structure matching stuff in, but I would really
> > prefer to keep it as is if you don't care too much.
>
> Do you have a link to those earlier patches?

This is the first patchset:

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788057.html

In particular you can see the code for matching functions here:

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788073.html

And parameter matching code here:

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788072.html

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788086.html

My apologies in advance, but the code at this early stage had not
adopted the kunit_* prefix and was still using the test_* and mock_*
prefix. (Hence, struct kunit_stream was known as struct test_stream).

> > > It seems far simpler to get rid of the string stream API and just have a
> > > struct for this.
> > >
> > >         struct kunit_fail_msg {
> > >                 const char *line;
> > >                 const char *file;
> > >                 const char *func;
> > >                 const char *msg;
> > >         };
> > >
> > > Then you can have the assertion macros create this on the stack (with
> > > another macro?).
> > >
> > >         #define DEFINE_KUNIT_FAIL_MSG(name, _msg) \
> > >                 struct kunit_fail_msg name = { \
> > >                         .line =  __LINE__, \
> > >                         .file = __FILE__, \
> > >                         .func = __func__, \
> > >                         .msg = _msg, \
> > >                 }
> > >
> > > I don't want to derail this whole series on this topic, but it seems
> > > like a bunch of code is there to construct this same set of information
> > > over and over again into a buffer a little bit at a time and then throw
> > > it away when nothing fails just because we may want to support the case
> > > where we have some unstructured data to inform the user about.
> >
> > Yeah, that's fair. I think there are a number of improvements to be
> > made with how the expectations are defined other than that, but I was
> > hoping I could do that after this patchset is merged. I just figured
> > with the kinds of things I would like to do, it would lead to a whole
> > new round of discussion.
> >
> > In either case, I think I would still like to use the `struct
> > kunit_stream` as part of the interface to share the failure message
> > with the test case runner code in test.c, at least eventually, so that
> > I only have to have one way to receive data from expectations, but I
> > think I can do that and still do what you suggest by just constructing
> > the kunit_stream at the end of expectations where it is feasible.
> >
> > All in all I agree with what you are saying, but I would rather do it
> > as a follow up possibly once we have some more code on the table. I
> > could just see this opening up a whole new can of worms where we
> > debate about exactly how expectations and assertions work for another
> > several months, only to rip it all out shortly there after. I know
> > that's how these things go, but that's my preference.
> >
> > I can do what you suggest if you feel strongly about it, but I would
> > prefer to hold off until later. It's your call.
> >
>
> The crux of my complaint is that the string stream API is too loosely
> defined to be usable. It allows tests to build up a string of
> unstructured information, but with certain calling constraints so we
> have to tread carefully. If there was more structure to the data that's
> being recorded then the test case runner could operate on the data
> without having to do string/stream operations, allocations, etc. This
> would make the assertion logic much more concrete and specific to kunit,
> instead of this small kunit wrapper that's been placed on top of string
> stream.

Yeah, I can see the point of wanting something that provides more
structure than the raw `struct kunit_stream` interface. In fact, it is
something I had already started working on, when I had determined it
would be a large effort to capture all the variations. I was further
put off from the idea when I had been asked to convert the KUnit
intermediate format from what I was using to TAP, because, as it is,
the current data printed out by KUnit doesn't contain all the data I
would like to put in it in a way that best takes advantage of the TAP
specification. One problematic area in particular: TAP already
provides a way to present a lot of the data I would like to export,
but it involves JSON serialization which was an idea that some of the
other reviewers understandably weren't too keen on. TAP also wants to
report data some time after it is available, which is generally not a
good idea for test debug information; you want to make it available as
soon as you can or you risk crashing with the data still inside.

Hence, I decided we could probably spend a good long while debating
how I present the information. So the idea of having a loose
definition seemed attractive to me in its own right since it would
likely conform to whatever we ended up deciding in the long run. Also,
all the better that it was what I already had and no one seemed to
mind too much.

The only constant I expect is that `struct kunit` will likely need to
take an abstract object with a `commit` method, or a `format` method
or whatever so it could control when data was going to be printed out
to the user. We will probably also use a string builder in there
somewhere.

> TL;DR: If we can get rid of the string stream API I'd view that as an
> improvement because building arbitrary strings in the kernel is complex,
> error prone and has calling context concerns.

True. No argument there.

> Is the intention that other code besides unit tests will use this string
> stream API to build up strings? Any targets in mind? This would be a
> good way to get the API merged upstream given that its 2019 and we
> haven't had such an API in the kernel so far.

Someone, (was it you?) asked about code sharing with a string builder
thingy that was used for creating structured human readable files, but
that seemed like a pretty massive undertaking.

Aside from that, no. I would kind of prefered that nobody used it for
anything else because I the issues you described.

Nevertheless, I think the debate over the usefulness of the
string_stream and kunit_stream are separate topics. Even if we made
kunit_stream more structured, I am pretty sure I would want to use
string_stream or some variation for constructing the message.

> An "object oriented" (strong quotes!) approach where kunit_fail_msg is
> the innermost struct in some assertion specific structure might work
> nicely and allow the test runner to call a generic 'format' function to
> print out the message based on the type of assertion/expectation it is.
> It probably would mean less code size too because the strings that are
> common will be in the common printing function instead of created twice,
> in the macros/code and then copied to the heap for the string stream.
>
>         struct kunit_assert {
>                 const char *line;
>                 const char *file;
>                 const char *func;
>                 void (*format)(struct kunit_assert *assert);
>         };
>
>         struct kunit_comparison_assert {
>                 enum operator operator;
>                 const char *left;
>                 const char *right;
>                 struct kunit_assert assert;
>         };
>
>         struct kunit_bool_assert {
>                 const char *truth;
>                 const char *statement;
>                 struct kunit_assert assert;
>         };
>
>         void kunit_format_comparison(struct kunit_assert *assert)
>         {
>                 struct kunit_comparison_assert *comp = container_of(assert, ...)
>
>                 kunit_printk(...)
>         }

I started working on something similarish, but by the time I ended up
coming up with a parent object whose definition was loose enough to
satisfy all the properties required by the child classes it ended up
basically being the same as what I have now just with a more complex
hierarchy of message manipulation logic.

On the other hand, I didn't have the idea of doing the parent object
quite the way you did and that would clean up a lot of the duplicated
first line logic.

I would like to give it a try, but I am afraid I am going to get
sucked down a really deep rabbit hole.

> Maybe other people have opinions here on if you should do it now or
> later. Future coding is not a great argument because it's hard to
> predict the future. On the other hand, this patchset is in good shape to

Yeah, that's kind of why I am afraid to go down this road when I have
something that works now and I know works with the mocking stuff I
want to do.

I would like to try your suggestion, but I want to try to make it work
with my mocking patches before I commit to it because otherwise I am
just going to have to back it out in a follow up patchset.

> merge and I'd like to use it to write unit tests for code I maintain so
> I don't want to see this stall out. Sorry if I'm opening the can of
> worms you're talking about.

Don't be sorry. I agree with you that the kunit_stream stuff is not very pretty.

Shuah, have we missed the merge window for 5.3?

I saw you only sent one PR out so far for this release, and there
wasn't much in it; I imagine you are going to send at least one more?

I figure, if we still got time to try out your suggestion, Stephen, no
harm in trying.

Also if we missed it, then I have another couple months to play around with it.

What do you think?

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-18 19:22               ` Brendan Higgins
@ 2019-07-19  0:08                 ` Brendan Higgins
  2019-07-22 18:10                   ` Brendan Higgins
  2019-07-22 20:03                   ` Stephen Boyd
  0 siblings, 2 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-19  0:08 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Thu, Jul 18, 2019 at 12:22:33PM -0700, Brendan Higgins wrote:
> On Thu, Jul 18, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Brendan Higgins (2019-07-16 11:52:01)
> > > On Tue, Jul 16, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
[...]
> > Do you have a link to those earlier patches?
> 
> This is the first patchset:
> 
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788057.html
> 
> In particular you can see the code for matching functions here:
> 
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788073.html
> 
> And parameter matching code here:
> 
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788072.html
> 
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788086.html
> 
> My apologies in advance, but the code at this early stage had not
> adopted the kunit_* prefix and was still using the test_* and mock_*
> prefix. (Hence, struct kunit_stream was known as struct test_stream).
[...]
> > The crux of my complaint is that the string stream API is too loosely
> > defined to be usable. It allows tests to build up a string of
> > unstructured information, but with certain calling constraints so we
> > have to tread carefully. If there was more structure to the data that's
> > being recorded then the test case runner could operate on the data
> > without having to do string/stream operations, allocations, etc. This
> > would make the assertion logic much more concrete and specific to kunit,
> > instead of this small kunit wrapper that's been placed on top of string
> > stream.
> 
> Yeah, I can see the point of wanting something that provides more
> structure than the raw `struct kunit_stream` interface. In fact, it is
> something I had already started working on, when I had determined it
> would be a large effort to capture all the variations. I was further
> put off from the idea when I had been asked to convert the KUnit
> intermediate format from what I was using to TAP, because, as it is,
> the current data printed out by KUnit doesn't contain all the data I
> would like to put in it in a way that best takes advantage of the TAP
> specification. One problematic area in particular: TAP already
> provides a way to present a lot of the data I would like to export,
> but it involves JSON serialization which was an idea that some of the
> other reviewers understandably weren't too keen on. TAP also wants to
> report data some time after it is available, which is generally not a
> good idea for test debug information; you want to make it available as
> soon as you can or you risk crashing with the data still inside.
> 
> Hence, I decided we could probably spend a good long while debating
> how I present the information. So the idea of having a loose
> definition seemed attractive to me in its own right since it would
> likely conform to whatever we ended up deciding in the long run. Also,
> all the better that it was what I already had and no one seemed to
> mind too much.
> 
> The only constant I expect is that `struct kunit` will likely need to
> take an abstract object with a `commit` method, or a `format` method
> or whatever so it could control when data was going to be printed out
> to the user. We will probably also use a string builder in there
> somewhere.
> 
> > TL;DR: If we can get rid of the string stream API I'd view that as an
> > improvement because building arbitrary strings in the kernel is complex,
> > error prone and has calling context concerns.
> 
> True. No argument there.
> 
> > Is the intention that other code besides unit tests will use this string
> > stream API to build up strings? Any targets in mind? This would be a
> > good way to get the API merged upstream given that its 2019 and we
> > haven't had such an API in the kernel so far.
> 
> Someone, (was it you?) asked about code sharing with a string builder
> thingy that was used for creating structured human readable files, but
> that seemed like a pretty massive undertaking.
> 
> Aside from that, no. I would kind of prefered that nobody used it for
> anything else because I the issues you described.
> 
> Nevertheless, I think the debate over the usefulness of the
> string_stream and kunit_stream are separate topics. Even if we made
> kunit_stream more structured, I am pretty sure I would want to use
> string_stream or some variation for constructing the message.
> 
> > An "object oriented" (strong quotes!) approach where kunit_fail_msg is
> > the innermost struct in some assertion specific structure might work
> > nicely and allow the test runner to call a generic 'format' function to
> > print out the message based on the type of assertion/expectation it is.
> > It probably would mean less code size too because the strings that are
> > common will be in the common printing function instead of created twice,
> > in the macros/code and then copied to the heap for the string stream.
> >
> >         struct kunit_assert {
> >                 const char *line;
> >                 const char *file;
> >                 const char *func;
> >                 void (*format)(struct kunit_assert *assert);
> >         };
> >
> >         struct kunit_comparison_assert {
> >                 enum operator operator;
> >                 const char *left;
> >                 const char *right;
> >                 struct kunit_assert assert;
> >         };
> >
> >         struct kunit_bool_assert {
> >                 const char *truth;
> >                 const char *statement;
> >                 struct kunit_assert assert;
> >         };
> >
> >         void kunit_format_comparison(struct kunit_assert *assert)
> >         {
> >                 struct kunit_comparison_assert *comp = container_of(assert, ...)
> >
> >                 kunit_printk(...)
> >         }

I started poking around with your suggestion while we are waiting. A
couple early observations:

1) It is actually easier to do than I previously thought and will probably
   help with getting more of the planned TAP output stuff working.

   That being said, this is still a pretty substantial undertaking and
   will likely take *at least* a week to implement and properly review.
   Assuming everything goes extremely well (no unexpected issues on my
   end, very responsive reviewers, etc).

2) It *will* eliminate the need for kunit_stream.

3) ...but, it *will not* eliminate the need for string_stream.

Based on my early observations, I do think it is worth doing, but I
don't think it is worth trying to make it in this patchset (unless I
have already missed the window, or it is going to be open for a while):
I do think it will make things much cleaner, but I don't think it will
achieve your desired goal of getting rid of an unstructured
{kunit|string}_stream style interface; it just adds a layer on top of it
that makes it harder to misuse.

I attached a patch of what I have so far at the end of this email so you
can see what I am talking about. And of course, if you agree with my
assessment, so we can start working on it as a future patch.

A couple things in regard to the patch I attached:

1) I wrote it pretty quickly so there are almost definitely mistakes.
   You should consider it RFC. I did verify it compiles though.

2) Also, I did use kunit_stream in writing it: all occurences should be
   pretty easy to replace with string_stream; nevertheless, the reason
   for this is just to make it easier to play with the current APIs. I
   wanted to have something working before I went through a big tedious
   refactoring. So sorry if it causes any confusion.

3) I also based the patch on all the KUnit patches I have queued up
   (includes things like mocking and such) since I want to see how this
   serialization thing will work with mocks and matchers and things like
   that.

> I started working on something similarish, but by the time I ended up
> coming up with a parent object whose definition was loose enough to
> satisfy all the properties required by the child classes it ended up
> basically being the same as what I have now just with a more complex
> hierarchy of message manipulation logic.
> 
> On the other hand, I didn't have the idea of doing the parent object
> quite the way you did and that would clean up a lot of the duplicated
> first line logic.
> 
> I would like to give it a try, but I am afraid I am going to get
> sucked down a really deep rabbit hole.
> 
> > Maybe other people have opinions here on if you should do it now or
> > later. Future coding is not a great argument because it's hard to
> > predict the future. On the other hand, this patchset is in good shape to
> 
> Yeah, that's kind of why I am afraid to go down this road when I have
> something that works now and I know works with the mocking stuff I
> want to do.
> 
> I would like to try your suggestion, but I want to try to make it work
> with my mocking patches before I commit to it because otherwise I am
> just going to have to back it out in a follow up patchset.
> 
> > merge and I'd like to use it to write unit tests for code I maintain so
> > I don't want to see this stall out. Sorry if I'm opening the can of
> > worms you're talking about.
> 
> Don't be sorry. I agree with you that the kunit_stream stuff is not very pretty.
> 
> Shuah, have we missed the merge window for 5.3?
> 
> I saw you only sent one PR out so far for this release, and there
> wasn't much in it; I imagine you are going to send at least one more?
> 
> I figure, if we still got time to try out your suggestion, Stephen, no
> harm in trying.
> 
> Also if we missed it, then I have another couple months to play around with it.
> 
> What do you think?

I attached the patch mentioned above below. Let me know what you think!

Cheers!

From 53d475d3d56afcf92b452c6d347dbedfa1a17d34 Mon Sep 17 00:00:00 2001
From: Brendan Higgins <brendanhiggins@google.com>
Date: Thu, 18 Jul 2019 16:08:52 -0700
Subject: [PATCH v1] DO NOT MERGE: started playing around with the
 serialization api

---
 include/kunit/assert.h | 130 ++++++++++++++++++++++++++++++
 include/kunit/mock.h   |   4 +
 kunit/Makefile         |   3 +-
 kunit/assert.c         | 179 +++++++++++++++++++++++++++++++++++++++++
 kunit/mock.c           |   6 +-
 5 files changed, 318 insertions(+), 4 deletions(-)
 create mode 100644 include/kunit/assert.h
 create mode 100644 kunit/assert.c

diff --git a/include/kunit/assert.h b/include/kunit/assert.h
new file mode 100644
index 0000000000000..e054fdff4642f
--- /dev/null
+++ b/include/kunit/assert.h
@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Assertion and expectation serialization API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#ifndef _KUNIT_ASSERT_H
+#define _KUNIT_ASSERT_H
+
+#include <kunit/test.h>
+#include <kunit/mock.h>
+
+enum kunit_assert_type {
+	KUNIT_ASSERTION,
+	KUNIT_EXPECTATION,
+};
+
+struct kunit_assert {
+	enum kunit_assert_type type;
+	const char *line;
+	const char *file;
+	struct va_format message;
+	void (*format)(struct kunit_assert *assert,
+		       struct kunit_stream *stream);
+};
+
+void kunit_base_assert_format(struct kunit_assert *assert,
+			      struct kunit_stream *stream);
+
+void kunit_assert_print_msg(struct kunit_assert *assert,
+			    struct kunit_stream *stream);
+
+struct kunit_unary_assert {
+	struct kunit_assert assert;
+	const char *condition;
+	bool expected_true;
+};
+
+void kunit_unary_assert_format(struct kunit_assert *assert,
+			       struct kunit_stream *stream);
+
+struct kunit_ptr_not_err_assert {
+	struct kunit_assert assert;
+	const char *text;
+	void *value;
+};
+
+void kunit_ptr_not_err_assert_format(struct kunit_assert *assert,
+				     struct kunit_stream *stream);
+
+struct kunit_binary_assert {
+	struct kunit_assert assert;
+	const char *operation;
+	const char *left_text;
+	long long left_value;
+	const char *right_text;
+	long long right_value;
+};
+
+void kunit_binary_assert_format(struct kunit_assert *assert,
+				struct kunit_stream *stream);
+
+struct kunit_binary_ptr_assert {
+	struct kunit_assert assert;
+	const char *operation;
+	const char *left_text;
+	void *left_value;
+	const char *right_text;
+	void *right_value;
+};
+
+void kunit_binary_ptr_assert_format(struct kunit_assert *assert,
+				    struct kunit_stream *stream);
+
+struct kunit_binary_str_assert {
+	struct kunit_assert assert;
+	const char *operation;
+	const char *left_text;
+	const char *left_value;
+	const char *right_text;
+	const char *right_value;
+};
+
+void kunit_binary_str_assert_format(struct kunit_assert *assert,
+				    struct kunit_stream *stream);
+
+struct kunit_mock_assert {
+	struct kunit_assert assert;
+};
+
+struct kunit_mock_no_expectations {
+	struct kunit_mock_assert assert;
+};
+
+struct kunit_mock_declaration {
+	const char *function_name;
+	const char **type_names;
+	const void **params;
+	int len;
+};
+
+void kunit_mock_declaration_format(struct kunit_mock_declaration *declaration,
+				   struct kunit_stream *stream);
+
+struct kunit_matcher_result {
+	struct kunit_assert assert;
+};
+
+struct kunit_mock_failed_match {
+	struct list_head node;
+	const char *expectation_text;
+	struct kunit_matcher_result *matcher_list;
+	size_t matcher_list_len;
+};
+
+void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
+				    struct kunit_stream *stream);
+
+struct kunit_mock_no_match {
+	struct kunit_mock_assert assert;
+	struct kunit_mock_declaration declaration;
+	struct list_head failed_match_list;
+};
+
+void kunit_mock_no_match_format(struct kunit_assert *assert,
+				struct kunit_stream *stream);
+
+#endif /*  _KUNIT_ASSERT_H */
diff --git a/include/kunit/mock.h b/include/kunit/mock.h
index 001b96af62f1e..52c9e427c831b 100644
--- a/include/kunit/mock.h
+++ b/include/kunit/mock.h
@@ -144,6 +144,10 @@ void mock_register_formatter(struct mock_param_formatter *formatter);
 
 void mock_unregister_formatter(struct mock_param_formatter *formatter);
 
+void mock_format_param(struct kunit_stream *stream,
+		       const char *type_name,
+		       const void *param);
+
 struct mock *mock_get_global_mock(void);
 
 #define MOCK(name) name##_mock
diff --git a/kunit/Makefile b/kunit/Makefile
index bbf43fcfb93a9..149d856a30f04 100644
--- a/kunit/Makefile
+++ b/kunit/Makefile
@@ -3,7 +3,8 @@ obj-$(CONFIG_KUNIT) +=			test.o \
 					common-mocks.o \
 					string-stream.o \
 					kunit-stream.o \
-					try-catch.o
+					try-catch.o \
+					assert.o
 
 obj-$(CONFIG_KUNIT_TEST) +=		test-test.o \
 					test-mock.o \
diff --git a/kunit/assert.c b/kunit/assert.c
new file mode 100644
index 0000000000000..75bb6922a994e
--- /dev/null
+++ b/kunit/assert.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Assertion and expectation serialization API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+#include <kunit/assert.h>
+
+void kunit_base_assert_format(struct kunit_assert *assert,
+			      struct kunit_stream *stream)
+{
+	const char *expect_or_assert;
+
+	if (assert->type == KUNIT_EXPECTATION)
+		expect_or_assert = "EXPECTATION";
+	else
+		expect_or_assert = "ASSERTION";
+
+	kunit_stream_add(stream, "%s FAILED at %s:%s\n",
+			 expect_or_assert, assert->file, assert->line);
+}
+
+void kunit_assert_print_msg(struct kunit_assert *assert,
+			    struct kunit_stream *stream)
+{
+	if (assert->message.fmt)
+		kunit_stream_add(stream, "\n%pV", &assert->message);
+}
+
+void kunit_unary_assert_format(struct kunit_assert *assert,
+			       struct kunit_stream *stream)
+{
+	struct kunit_unary_assert *unary_assert = container_of(
+			assert, struct kunit_unary_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	if (unary_assert->expected_true)
+		kunit_stream_add(stream,
+				 "\tExpected %s to be true, but is false\n",
+				 unary_assert->condition);
+	else
+		kunit_stream_add(stream,
+				 "\tExpected %s to be false, but is true\n",
+				 unary_assert->condition);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_ptr_not_err_assert_format(struct kunit_assert *assert,
+				     struct kunit_stream *stream)
+{
+	struct kunit_ptr_not_err_assert *ptr_assert = container_of(
+			assert, struct kunit_ptr_not_err_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	if (!ptr_assert->value) {
+		kunit_stream_add(stream,
+				 "\tExpected %s is not null, but is\n",
+				 ptr_assert->text);
+	} else if (IS_ERR(ptr_assert->value)) {
+		kunit_stream_add(stream,
+				 "\tExpected %s is not error, but is: %ld\n",
+				 ptr_assert->text,
+				 PTR_ERR(ptr_assert->value));
+	}
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_binary_assert_format(struct kunit_assert *assert,
+				struct kunit_stream *stream)
+{
+	struct kunit_binary_assert *binary_assert = container_of(
+			assert, struct kunit_binary_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	kunit_stream_add(stream,
+			 "\tExpected %s %s %s, but\n",
+			 binary_assert->left_text,
+			 binary_assert->operation,
+			 binary_assert->right_text);
+	kunit_stream_add(stream, "\t\t%s == %lld\n",
+			 binary_assert->left_text,
+			 binary_assert->left_value);
+	kunit_stream_add(stream, "\t\t%s == %lld",
+			 binary_assert->right_text,
+			 binary_assert->right_value);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_binary_ptr_assert_format(struct kunit_assert *assert,
+				    struct kunit_stream *stream)
+{
+	struct kunit_binary_ptr_assert *binary_assert = container_of(
+			assert, struct kunit_binary_ptr_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	kunit_stream_add(stream,
+			 "\tExpected %s %s %s, but\n",
+			 binary_assert->left_text,
+			 binary_assert->operation,
+			 binary_assert->right_text);
+	kunit_stream_add(stream, "\t\t%s == %pK\n",
+			 binary_assert->left_text,
+			 binary_assert->left_value);
+	kunit_stream_add(stream, "\t\t%s == %pK",
+			 binary_assert->right_text,
+			 binary_assert->right_value);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_binary_str_assert_format(struct kunit_assert *assert,
+				    struct kunit_stream *stream)
+{
+	struct kunit_binary_str_assert *binary_assert = container_of(
+			assert, struct kunit_binary_str_assert, assert);
+
+	kunit_base_assert_format(assert, stream);
+	kunit_stream_add(stream,
+			 "\tExpected %s %s %s, but\n",
+			 binary_assert->left_text,
+			 binary_assert->operation,
+			 binary_assert->right_text);
+	kunit_stream_add(stream, "\t\t%s == %s\n",
+			 binary_assert->left_text,
+			 binary_assert->left_value);
+	kunit_stream_add(stream, "\t\t%s == %s",
+			 binary_assert->right_text,
+			 binary_assert->right_value);
+	kunit_assert_print_msg(assert, stream);
+}
+
+void kunit_mock_declaration_format(struct kunit_mock_declaration *declaration,
+				   struct kunit_stream *stream)
+{
+	int i;
+
+	kunit_stream_add(stream, "%s(", declaration->function_name);
+	for (i = 0; i < declaration->len; i++) {
+		mock_format_param(stream,
+				  declaration->type_names[i],
+				  declaration->params[i]);
+		if (i < declaration->len - 1)
+			kunit_stream_add(stream, ", ");
+	}
+	kunit_stream_add(stream, ")\n");
+}
+
+void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
+				    struct kunit_stream *stream)
+{
+	struct kunit_matcher_result *result;
+	size_t i;
+
+	kunit_stream_add(stream,
+			 "Tried expectation: %s, but\n",
+			 match->expectation_text);
+	for (i = 0; i < match->matcher_list_len; i++) {
+		result = &match->matcher_list[i];
+		kunit_stream_add(stream, "\t");
+		result->assert.format(&result->assert, stream);
+		kunit_stream_add(stream, "\n");
+	}
+}
+
+void kunit_mock_no_match_format(struct kunit_assert *assert,
+				struct kunit_stream *stream)
+{
+	struct kunit_mock_assert *mock_assert = container_of(
+			assert, struct kunit_mock_assert, assert);
+	struct kunit_mock_no_match *no_match = container_of(
+			mock_assert, struct kunit_mock_no_match, assert);
+	struct kunit_mock_failed_match *expectation;
+
+	kunit_base_assert_format(assert, stream);
+	kunit_mock_declaration_format(&no_match->declaration, stream);
+
+	list_for_each_entry(expectation, &no_match->failed_match_list, node)
+		kunit_mock_failed_match_format(expectation, stream);
+}
diff --git a/kunit/mock.c b/kunit/mock.c
index ccb0abe111402..ab441a58a918c 100644
--- a/kunit/mock.c
+++ b/kunit/mock.c
@@ -269,9 +269,9 @@ struct mock_param_formatter *mock_find_formatter(const char *type_name)
 	return NULL;
 }
 
-static void mock_format_param(struct kunit_stream *stream,
-			      const char *type_name,
-			      const void *param)
+void mock_format_param(struct kunit_stream *stream,
+		       const char *type_name,
+		       const void *param)
 {
 	struct mock_param_formatter *formatter;
 
-- 
2.22.0.657.g960e92d24f-goog


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-19  0:08                 ` Brendan Higgins
@ 2019-07-22 18:10                   ` Brendan Higgins
  2019-07-22 20:03                   ` Stephen Boyd
  1 sibling, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-22 18:10 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Thu, Jul 18, 2019 at 5:08 PM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> On Thu, Jul 18, 2019 at 12:22:33PM -0700, Brendan Higgins wrote:
> > On Thu, Jul 18, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Brendan Higgins (2019-07-16 11:52:01)
> > > > On Tue, Jul 16, 2019 at 10:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
> [...]
> > > Do you have a link to those earlier patches?
> >
> > This is the first patchset:
> >
> > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788057.html
> >
> > In particular you can see the code for matching functions here:
> >
> > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788073.html
> >
> > And parameter matching code here:
> >
> > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788072.html
> >
> > https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1788086.html
> >
> > My apologies in advance, but the code at this early stage had not
> > adopted the kunit_* prefix and was still using the test_* and mock_*
> > prefix. (Hence, struct kunit_stream was known as struct test_stream).
> [...]
> > > The crux of my complaint is that the string stream API is too loosely
> > > defined to be usable. It allows tests to build up a string of
> > > unstructured information, but with certain calling constraints so we
> > > have to tread carefully. If there was more structure to the data that's
> > > being recorded then the test case runner could operate on the data
> > > without having to do string/stream operations, allocations, etc. This
> > > would make the assertion logic much more concrete and specific to kunit,
> > > instead of this small kunit wrapper that's been placed on top of string
> > > stream.
> >
> > Yeah, I can see the point of wanting something that provides more
> > structure than the raw `struct kunit_stream` interface. In fact, it is
> > something I had already started working on, when I had determined it
> > would be a large effort to capture all the variations. I was further
> > put off from the idea when I had been asked to convert the KUnit
> > intermediate format from what I was using to TAP, because, as it is,
> > the current data printed out by KUnit doesn't contain all the data I
> > would like to put in it in a way that best takes advantage of the TAP
> > specification. One problematic area in particular: TAP already
> > provides a way to present a lot of the data I would like to export,
> > but it involves JSON serialization which was an idea that some of the
> > other reviewers understandably weren't too keen on. TAP also wants to
> > report data some time after it is available, which is generally not a
> > good idea for test debug information; you want to make it available as
> > soon as you can or you risk crashing with the data still inside.
> >
> > Hence, I decided we could probably spend a good long while debating
> > how I present the information. So the idea of having a loose
> > definition seemed attractive to me in its own right since it would
> > likely conform to whatever we ended up deciding in the long run. Also,
> > all the better that it was what I already had and no one seemed to
> > mind too much.
> >
> > The only constant I expect is that `struct kunit` will likely need to
> > take an abstract object with a `commit` method, or a `format` method
> > or whatever so it could control when data was going to be printed out
> > to the user. We will probably also use a string builder in there
> > somewhere.
> >
> > > TL;DR: If we can get rid of the string stream API I'd view that as an
> > > improvement because building arbitrary strings in the kernel is complex,
> > > error prone and has calling context concerns.
> >
> > True. No argument there.
> >
> > > Is the intention that other code besides unit tests will use this string
> > > stream API to build up strings? Any targets in mind? This would be a
> > > good way to get the API merged upstream given that its 2019 and we
> > > haven't had such an API in the kernel so far.
> >
> > Someone, (was it you?) asked about code sharing with a string builder
> > thingy that was used for creating structured human readable files, but
> > that seemed like a pretty massive undertaking.
> >
> > Aside from that, no. I would kind of prefered that nobody used it for
> > anything else because I the issues you described.
> >
> > Nevertheless, I think the debate over the usefulness of the
> > string_stream and kunit_stream are separate topics. Even if we made
> > kunit_stream more structured, I am pretty sure I would want to use
> > string_stream or some variation for constructing the message.
> >
> > > An "object oriented" (strong quotes!) approach where kunit_fail_msg is
> > > the innermost struct in some assertion specific structure might work
> > > nicely and allow the test runner to call a generic 'format' function to
> > > print out the message based on the type of assertion/expectation it is.
> > > It probably would mean less code size too because the strings that are
> > > common will be in the common printing function instead of created twice,
> > > in the macros/code and then copied to the heap for the string stream.
> > >
> > >         struct kunit_assert {
> > >                 const char *line;
> > >                 const char *file;
> > >                 const char *func;
> > >                 void (*format)(struct kunit_assert *assert);
> > >         };
> > >
> > >         struct kunit_comparison_assert {
> > >                 enum operator operator;
> > >                 const char *left;
> > >                 const char *right;
> > >                 struct kunit_assert assert;
> > >         };
> > >
> > >         struct kunit_bool_assert {
> > >                 const char *truth;
> > >                 const char *statement;
> > >                 struct kunit_assert assert;
> > >         };
> > >
> > >         void kunit_format_comparison(struct kunit_assert *assert)
> > >         {
> > >                 struct kunit_comparison_assert *comp = container_of(assert, ...)
> > >
> > >                 kunit_printk(...)
> > >         }
>
> I started poking around with your suggestion while we are waiting. A
> couple early observations:
>
> 1) It is actually easier to do than I previously thought and will probably
>    help with getting more of the planned TAP output stuff working.
>
>    That being said, this is still a pretty substantial undertaking and
>    will likely take *at least* a week to implement and properly review.
>    Assuming everything goes extremely well (no unexpected issues on my
>    end, very responsive reviewers, etc).
>
> 2) It *will* eliminate the need for kunit_stream.
>
> 3) ...but, it *will not* eliminate the need for string_stream.
>
> Based on my early observations, I do think it is worth doing, but I
> don't think it is worth trying to make it in this patchset (unless I
> have already missed the window, or it is going to be open for a while):
> I do think it will make things much cleaner, but I don't think it will
> achieve your desired goal of getting rid of an unstructured
> {kunit|string}_stream style interface; it just adds a layer on top of it
> that makes it harder to misuse.
>
> I attached a patch of what I have so far at the end of this email so you
> can see what I am talking about. And of course, if you agree with my
> assessment, so we can start working on it as a future patch.
>
> A couple things in regard to the patch I attached:
>
> 1) I wrote it pretty quickly so there are almost definitely mistakes.
>    You should consider it RFC. I did verify it compiles though.
>
> 2) Also, I did use kunit_stream in writing it: all occurences should be
>    pretty easy to replace with string_stream; nevertheless, the reason
>    for this is just to make it easier to play with the current APIs. I
>    wanted to have something working before I went through a big tedious
>    refactoring. So sorry if it causes any confusion.
>
> 3) I also based the patch on all the KUnit patches I have queued up
>    (includes things like mocking and such) since I want to see how this
>    serialization thing will work with mocks and matchers and things like
>    that.
>
> > I started working on something similarish, but by the time I ended up
> > coming up with a parent object whose definition was loose enough to
> > satisfy all the properties required by the child classes it ended up
> > basically being the same as what I have now just with a more complex
> > hierarchy of message manipulation logic.
> >
> > On the other hand, I didn't have the idea of doing the parent object
> > quite the way you did and that would clean up a lot of the duplicated
> > first line logic.
> >
> > I would like to give it a try, but I am afraid I am going to get
> > sucked down a really deep rabbit hole.
> >
> > > Maybe other people have opinions here on if you should do it now or
> > > later. Future coding is not a great argument because it's hard to
> > > predict the future. On the other hand, this patchset is in good shape to
> >
> > Yeah, that's kind of why I am afraid to go down this road when I have
> > something that works now and I know works with the mocking stuff I
> > want to do.
> >
> > I would like to try your suggestion, but I want to try to make it work
> > with my mocking patches before I commit to it because otherwise I am
> > just going to have to back it out in a follow up patchset.
> >
> > > merge and I'd like to use it to write unit tests for code I maintain so
> > > I don't want to see this stall out. Sorry if I'm opening the can of
> > > worms you're talking about.
> >
> > Don't be sorry. I agree with you that the kunit_stream stuff is not very pretty.
> >
> > Shuah, have we missed the merge window for 5.3?
> >
> > I saw you only sent one PR out so far for this release, and there
> > wasn't much in it; I imagine you are going to send at least one more?
> >
> > I figure, if we still got time to try out your suggestion, Stephen, no
> > harm in trying.
> >
> > Also if we missed it, then I have another couple months to play around with it.
> >
> > What do you think?

I talked to Shuah off thread, she would like us to resolve this
discussion before accepting the patchset.

She also said that this is probably going to have to wait until v5.4.

Nevertheless, Stephen, would you mind taking a look at the patch I
posted below? I would like to get your thoughts on the sum of all the
changes I am going to have to make before I try to integrate them into
the existing patches.

Sorry for being lazy, but I suspect you won't like the first pass of
how I am doing it, and I think it will probably be easier for you to
give early feedback on it as its own change anyway.

> I attached the patch mentioned above below. Let me know what you think!
>
> Cheers!
>
> From 53d475d3d56afcf92b452c6d347dbedfa1a17d34 Mon Sep 17 00:00:00 2001
> From: Brendan Higgins <brendanhiggins@google.com>
> Date: Thu, 18 Jul 2019 16:08:52 -0700
> Subject: [PATCH v1] DO NOT MERGE: started playing around with the
>  serialization api
>
> ---
>  include/kunit/assert.h | 130 ++++++++++++++++++++++++++++++
>  include/kunit/mock.h   |   4 +
>  kunit/Makefile         |   3 +-
>  kunit/assert.c         | 179 +++++++++++++++++++++++++++++++++++++++++
>  kunit/mock.c           |   6 +-
>  5 files changed, 318 insertions(+), 4 deletions(-)
>  create mode 100644 include/kunit/assert.h
>  create mode 100644 kunit/assert.c
>
> diff --git a/include/kunit/assert.h b/include/kunit/assert.h
> new file mode 100644
> index 0000000000000..e054fdff4642f
> --- /dev/null
> +++ b/include/kunit/assert.h
> @@ -0,0 +1,130 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Assertion and expectation serialization API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#ifndef _KUNIT_ASSERT_H
> +#define _KUNIT_ASSERT_H
> +
> +#include <kunit/test.h>
> +#include <kunit/mock.h>
> +
> +enum kunit_assert_type {
> +       KUNIT_ASSERTION,
> +       KUNIT_EXPECTATION,
> +};
> +
> +struct kunit_assert {
> +       enum kunit_assert_type type;
> +       const char *line;
> +       const char *file;
> +       struct va_format message;
> +       void (*format)(struct kunit_assert *assert,
> +                      struct kunit_stream *stream);
> +};
> +
> +void kunit_base_assert_format(struct kunit_assert *assert,
> +                             struct kunit_stream *stream);
> +
> +void kunit_assert_print_msg(struct kunit_assert *assert,
> +                           struct kunit_stream *stream);
> +
> +struct kunit_unary_assert {
> +       struct kunit_assert assert;
> +       const char *condition;
> +       bool expected_true;
> +};
> +
> +void kunit_unary_assert_format(struct kunit_assert *assert,
> +                              struct kunit_stream *stream);
> +
> +struct kunit_ptr_not_err_assert {
> +       struct kunit_assert assert;
> +       const char *text;
> +       void *value;
> +};
> +
> +void kunit_ptr_not_err_assert_format(struct kunit_assert *assert,
> +                                    struct kunit_stream *stream);
> +
> +struct kunit_binary_assert {
> +       struct kunit_assert assert;
> +       const char *operation;
> +       const char *left_text;
> +       long long left_value;
> +       const char *right_text;
> +       long long right_value;
> +};
> +
> +void kunit_binary_assert_format(struct kunit_assert *assert,
> +                               struct kunit_stream *stream);
> +
> +struct kunit_binary_ptr_assert {
> +       struct kunit_assert assert;
> +       const char *operation;
> +       const char *left_text;
> +       void *left_value;
> +       const char *right_text;
> +       void *right_value;
> +};
> +
> +void kunit_binary_ptr_assert_format(struct kunit_assert *assert,
> +                                   struct kunit_stream *stream);
> +
> +struct kunit_binary_str_assert {
> +       struct kunit_assert assert;
> +       const char *operation;
> +       const char *left_text;
> +       const char *left_value;
> +       const char *right_text;
> +       const char *right_value;
> +};
> +
> +void kunit_binary_str_assert_format(struct kunit_assert *assert,
> +                                   struct kunit_stream *stream);
> +
> +struct kunit_mock_assert {
> +       struct kunit_assert assert;
> +};
> +
> +struct kunit_mock_no_expectations {
> +       struct kunit_mock_assert assert;
> +};
> +
> +struct kunit_mock_declaration {
> +       const char *function_name;
> +       const char **type_names;
> +       const void **params;
> +       int len;
> +};
> +
> +void kunit_mock_declaration_format(struct kunit_mock_declaration *declaration,
> +                                  struct kunit_stream *stream);
> +
> +struct kunit_matcher_result {
> +       struct kunit_assert assert;
> +};
> +
> +struct kunit_mock_failed_match {
> +       struct list_head node;
> +       const char *expectation_text;
> +       struct kunit_matcher_result *matcher_list;
> +       size_t matcher_list_len;
> +};
> +
> +void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
> +                                   struct kunit_stream *stream);
> +
> +struct kunit_mock_no_match {
> +       struct kunit_mock_assert assert;
> +       struct kunit_mock_declaration declaration;
> +       struct list_head failed_match_list;
> +};
> +
> +void kunit_mock_no_match_format(struct kunit_assert *assert,
> +                               struct kunit_stream *stream);
> +
> +#endif /*  _KUNIT_ASSERT_H */
> diff --git a/include/kunit/mock.h b/include/kunit/mock.h
> index 001b96af62f1e..52c9e427c831b 100644
> --- a/include/kunit/mock.h
> +++ b/include/kunit/mock.h
> @@ -144,6 +144,10 @@ void mock_register_formatter(struct mock_param_formatter *formatter);
>
>  void mock_unregister_formatter(struct mock_param_formatter *formatter);
>
> +void mock_format_param(struct kunit_stream *stream,
> +                      const char *type_name,
> +                      const void *param);
> +
>  struct mock *mock_get_global_mock(void);
>
>  #define MOCK(name) name##_mock
> diff --git a/kunit/Makefile b/kunit/Makefile
> index bbf43fcfb93a9..149d856a30f04 100644
> --- a/kunit/Makefile
> +++ b/kunit/Makefile
> @@ -3,7 +3,8 @@ obj-$(CONFIG_KUNIT) +=                  test.o \
>                                         common-mocks.o \
>                                         string-stream.o \
>                                         kunit-stream.o \
> -                                       try-catch.o
> +                                       try-catch.o \
> +                                       assert.o
>
>  obj-$(CONFIG_KUNIT_TEST) +=            test-test.o \
>                                         test-mock.o \
> diff --git a/kunit/assert.c b/kunit/assert.c
> new file mode 100644
> index 0000000000000..75bb6922a994e
> --- /dev/null
> +++ b/kunit/assert.c
> @@ -0,0 +1,179 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Assertion and expectation serialization API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +#include <kunit/assert.h>
> +
> +void kunit_base_assert_format(struct kunit_assert *assert,
> +                             struct kunit_stream *stream)
> +{
> +       const char *expect_or_assert;
> +
> +       if (assert->type == KUNIT_EXPECTATION)
> +               expect_or_assert = "EXPECTATION";
> +       else
> +               expect_or_assert = "ASSERTION";
> +
> +       kunit_stream_add(stream, "%s FAILED at %s:%s\n",
> +                        expect_or_assert, assert->file, assert->line);
> +}
> +
> +void kunit_assert_print_msg(struct kunit_assert *assert,
> +                           struct kunit_stream *stream)
> +{
> +       if (assert->message.fmt)
> +               kunit_stream_add(stream, "\n%pV", &assert->message);
> +}
> +
> +void kunit_unary_assert_format(struct kunit_assert *assert,
> +                              struct kunit_stream *stream)
> +{
> +       struct kunit_unary_assert *unary_assert = container_of(
> +                       assert, struct kunit_unary_assert, assert);
> +
> +       kunit_base_assert_format(assert, stream);
> +       if (unary_assert->expected_true)
> +               kunit_stream_add(stream,
> +                                "\tExpected %s to be true, but is false\n",
> +                                unary_assert->condition);
> +       else
> +               kunit_stream_add(stream,
> +                                "\tExpected %s to be false, but is true\n",
> +                                unary_assert->condition);
> +       kunit_assert_print_msg(assert, stream);
> +}
> +
> +void kunit_ptr_not_err_assert_format(struct kunit_assert *assert,
> +                                    struct kunit_stream *stream)
> +{
> +       struct kunit_ptr_not_err_assert *ptr_assert = container_of(
> +                       assert, struct kunit_ptr_not_err_assert, assert);
> +
> +       kunit_base_assert_format(assert, stream);
> +       if (!ptr_assert->value) {
> +               kunit_stream_add(stream,
> +                                "\tExpected %s is not null, but is\n",
> +                                ptr_assert->text);
> +       } else if (IS_ERR(ptr_assert->value)) {
> +               kunit_stream_add(stream,
> +                                "\tExpected %s is not error, but is: %ld\n",
> +                                ptr_assert->text,
> +                                PTR_ERR(ptr_assert->value));
> +       }
> +       kunit_assert_print_msg(assert, stream);
> +}
> +
> +void kunit_binary_assert_format(struct kunit_assert *assert,
> +                               struct kunit_stream *stream)
> +{
> +       struct kunit_binary_assert *binary_assert = container_of(
> +                       assert, struct kunit_binary_assert, assert);
> +
> +       kunit_base_assert_format(assert, stream);
> +       kunit_stream_add(stream,
> +                        "\tExpected %s %s %s, but\n",
> +                        binary_assert->left_text,
> +                        binary_assert->operation,
> +                        binary_assert->right_text);
> +       kunit_stream_add(stream, "\t\t%s == %lld\n",
> +                        binary_assert->left_text,
> +                        binary_assert->left_value);
> +       kunit_stream_add(stream, "\t\t%s == %lld",
> +                        binary_assert->right_text,
> +                        binary_assert->right_value);
> +       kunit_assert_print_msg(assert, stream);
> +}
> +

I could probably reduce some of the code duplication here by using a
variable type struct for left_value and right_value, but that would
actually increase the usage of {kunit|string}_stream; it is probably
the right thing to do, but I wanted to get your thoughts on it first.

> +void kunit_binary_ptr_assert_format(struct kunit_assert *assert,
> +                                   struct kunit_stream *stream)
> +{
> +       struct kunit_binary_ptr_assert *binary_assert = container_of(
> +                       assert, struct kunit_binary_ptr_assert, assert);
> +
> +       kunit_base_assert_format(assert, stream);
> +       kunit_stream_add(stream,
> +                        "\tExpected %s %s %s, but\n",
> +                        binary_assert->left_text,
> +                        binary_assert->operation,
> +                        binary_assert->right_text);
> +       kunit_stream_add(stream, "\t\t%s == %pK\n",
> +                        binary_assert->left_text,
> +                        binary_assert->left_value);
> +       kunit_stream_add(stream, "\t\t%s == %pK",
> +                        binary_assert->right_text,
> +                        binary_assert->right_value);
> +       kunit_assert_print_msg(assert, stream);
> +}
> +
> +void kunit_binary_str_assert_format(struct kunit_assert *assert,
> +                                   struct kunit_stream *stream)
> +{
> +       struct kunit_binary_str_assert *binary_assert = container_of(
> +                       assert, struct kunit_binary_str_assert, assert);
> +
> +       kunit_base_assert_format(assert, stream);
> +       kunit_stream_add(stream,
> +                        "\tExpected %s %s %s, but\n",
> +                        binary_assert->left_text,
> +                        binary_assert->operation,
> +                        binary_assert->right_text);
> +       kunit_stream_add(stream, "\t\t%s == %s\n",
> +                        binary_assert->left_text,
> +                        binary_assert->left_value);
> +       kunit_stream_add(stream, "\t\t%s == %s",
> +                        binary_assert->right_text,
> +                        binary_assert->right_value);
> +       kunit_assert_print_msg(assert, stream);
> +}
> +
> +void kunit_mock_declaration_format(struct kunit_mock_declaration *declaration,
> +                                  struct kunit_stream *stream)
> +{
> +       int i;
> +
> +       kunit_stream_add(stream, "%s(", declaration->function_name);
> +       for (i = 0; i < declaration->len; i++) {
> +               mock_format_param(stream,
> +                                 declaration->type_names[i],
> +                                 declaration->params[i]);
> +               if (i < declaration->len - 1)
> +                       kunit_stream_add(stream, ", ");
> +       }
> +       kunit_stream_add(stream, ")\n");
> +}
> +
> +void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
> +                                   struct kunit_stream *stream)
> +{
> +       struct kunit_matcher_result *result;
> +       size_t i;
> +
> +       kunit_stream_add(stream,
> +                        "Tried expectation: %s, but\n",
> +                        match->expectation_text);
> +       for (i = 0; i < match->matcher_list_len; i++) {
> +               result = &match->matcher_list[i];
> +               kunit_stream_add(stream, "\t");
> +               result->assert.format(&result->assert, stream);
> +               kunit_stream_add(stream, "\n");
> +       }
> +}
> +
> +void kunit_mock_no_match_format(struct kunit_assert *assert,
> +                               struct kunit_stream *stream)
> +{
> +       struct kunit_mock_assert *mock_assert = container_of(
> +                       assert, struct kunit_mock_assert, assert);
> +       struct kunit_mock_no_match *no_match = container_of(
> +                       mock_assert, struct kunit_mock_no_match, assert);
> +       struct kunit_mock_failed_match *expectation;
> +
> +       kunit_base_assert_format(assert, stream);
> +       kunit_mock_declaration_format(&no_match->declaration, stream);
> +
> +       list_for_each_entry(expectation, &no_match->failed_match_list, node)
> +               kunit_mock_failed_match_format(expectation, stream);
> +}
> diff --git a/kunit/mock.c b/kunit/mock.c
> index ccb0abe111402..ab441a58a918c 100644
> --- a/kunit/mock.c
> +++ b/kunit/mock.c
> @@ -269,9 +269,9 @@ struct mock_param_formatter *mock_find_formatter(const char *type_name)
>         return NULL;
>  }
>
> -static void mock_format_param(struct kunit_stream *stream,
> -                             const char *type_name,
> -                             const void *param)
> +void mock_format_param(struct kunit_stream *stream,
> +                      const char *type_name,
> +                      const void *param)
>  {
>         struct mock_param_formatter *formatter;
>
> --
> 2.22.0.657.g960e92d24f-goog
>

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-19  0:08                 ` Brendan Higgins
  2019-07-22 18:10                   ` Brendan Higgins
@ 2019-07-22 20:03                   ` Stephen Boyd
  2019-07-22 22:30                     ` Brendan Higgins
  1 sibling, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-07-22 20:03 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-18 17:08:34)
> On Thu, Jul 18, 2019 at 12:22:33PM -0700, Brendan Higgins wrote:
>
> I started poking around with your suggestion while we are waiting. A
> couple early observations:
> 
> 1) It is actually easier to do than I previously thought and will probably
>    help with getting more of the planned TAP output stuff working.
> 
>    That being said, this is still a pretty substantial undertaking and
>    will likely take *at least* a week to implement and properly review.
>    Assuming everything goes extremely well (no unexpected issues on my
>    end, very responsive reviewers, etc).
> 
> 2) It *will* eliminate the need for kunit_stream.
> 
> 3) ...but, it *will not* eliminate the need for string_stream.
> 
> Based on my early observations, I do think it is worth doing, but I
> don't think it is worth trying to make it in this patchset (unless I
> have already missed the window, or it is going to be open for a while):

The merge window is over. Typically code needs to be settled a few weeks
before it opens (i.e. around -rc4 or -rc5) for most maintainers to pick
up patches for the next merge window.

> I do think it will make things much cleaner, but I don't think it will
> achieve your desired goal of getting rid of an unstructured
> {kunit|string}_stream style interface; it just adds a layer on top of it
> that makes it harder to misuse.

Ok.

> 
> I attached a patch of what I have so far at the end of this email so you
> can see what I am talking about. And of course, if you agree with my
> assessment, so we can start working on it as a future patch.
> 
> A couple things in regard to the patch I attached:
> 
> 1) I wrote it pretty quickly so there are almost definitely mistakes.
>    You should consider it RFC. I did verify it compiles though.
> 
> 2) Also, I did use kunit_stream in writing it: all occurences should be
>    pretty easy to replace with string_stream; nevertheless, the reason
>    for this is just to make it easier to play with the current APIs. I
>    wanted to have something working before I went through a big tedious
>    refactoring. So sorry if it causes any confusion.
> 
> 3) I also based the patch on all the KUnit patches I have queued up
>    (includes things like mocking and such) since I want to see how this
>    serialization thing will work with mocks and matchers and things like
>    that.

Great!

> 
> From 53d475d3d56afcf92b452c6d347dbedfa1a17d34 Mon Sep 17 00:00:00 2001
> From: Brendan Higgins <brendanhiggins@google.com>
> Date: Thu, 18 Jul 2019 16:08:52 -0700
> Subject: [PATCH v1] DO NOT MERGE: started playing around with the
>  serialization api
> 
> ---
>  include/kunit/assert.h | 130 ++++++++++++++++++++++++++++++
>  include/kunit/mock.h   |   4 +
>  kunit/Makefile         |   3 +-
>  kunit/assert.c         | 179 +++++++++++++++++++++++++++++++++++++++++
>  kunit/mock.c           |   6 +-
>  5 files changed, 318 insertions(+), 4 deletions(-)
>  create mode 100644 include/kunit/assert.h
>  create mode 100644 kunit/assert.c
> 
> diff --git a/include/kunit/assert.h b/include/kunit/assert.h
> new file mode 100644
> index 0000000000000..e054fdff4642f
> --- /dev/null
> +++ b/include/kunit/assert.h
> @@ -0,0 +1,130 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Assertion and expectation serialization API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#ifndef _KUNIT_ASSERT_H
> +#define _KUNIT_ASSERT_H
> +
> +#include <kunit/test.h>
> +#include <kunit/mock.h>
> +
> +enum kunit_assert_type {
> +       KUNIT_ASSERTION,
> +       KUNIT_EXPECTATION,
> +};
> +
> +struct kunit_assert {
> +       enum kunit_assert_type type;
> +       const char *line;
> +       const char *file;
> +       struct va_format message;
> +       void (*format)(struct kunit_assert *assert,
> +                      struct kunit_stream *stream);

Would passing in the test help too?

> +};
> +
> +void kunit_base_assert_format(struct kunit_assert *assert,
> +                             struct kunit_stream *stream);
> +
> +void kunit_assert_print_msg(struct kunit_assert *assert,
> +                           struct kunit_stream *stream);
> +
> +struct kunit_unary_assert {
> +       struct kunit_assert assert;
> +       const char *condition;
> +       bool expected_true;
> +};
> +
> +void kunit_unary_assert_format(struct kunit_assert *assert,
> +                              struct kunit_stream *stream);
> +
> +struct kunit_ptr_not_err_assert {
> +       struct kunit_assert assert;
> +       const char *text;
> +       void *value;
> +};
> +
> +void kunit_ptr_not_err_assert_format(struct kunit_assert *assert,
> +                                    struct kunit_stream *stream);
> +
> +struct kunit_binary_assert {
> +       struct kunit_assert assert;
> +       const char *operation;
> +       const char *left_text;
> +       long long left_value;
> +       const char *right_text;
> +       long long right_value;
> +};
> +
> +void kunit_binary_assert_format(struct kunit_assert *assert,
> +                               struct kunit_stream *stream);
> +
> +struct kunit_binary_ptr_assert {
> +       struct kunit_assert assert;
> +       const char *operation;
> +       const char *left_text;
> +       void *left_value;
> +       const char *right_text;
> +       void *right_value;
> +};
> +
> +void kunit_binary_ptr_assert_format(struct kunit_assert *assert,
> +                                   struct kunit_stream *stream);
> +
> +struct kunit_binary_str_assert {
> +       struct kunit_assert assert;
> +       const char *operation;
> +       const char *left_text;
> +       const char *left_value;
> +       const char *right_text;
> +       const char *right_value;
> +};
> +
> +void kunit_binary_str_assert_format(struct kunit_assert *assert,
> +                                   struct kunit_stream *stream);
> +
> +struct kunit_mock_assert {
> +       struct kunit_assert assert;
> +};
> +
> +struct kunit_mock_no_expectations {
> +       struct kunit_mock_assert assert;
> +};

What's the purpose of making a wrapper struct with no other members?
Just to make a different struct for some sort of type checking? I guess
it's OK but I don't think it will be very useful in practice.

> +
> +struct kunit_mock_declaration {
> +       const char *function_name;
> +       const char **type_names;
> +       const void **params;
> +       int len;
> +};
> +
> +void kunit_mock_declaration_format(struct kunit_mock_declaration *declaration,
> +                                  struct kunit_stream *stream);
> +
> +struct kunit_matcher_result {
> +       struct kunit_assert assert;
> +};
> +
> +struct kunit_mock_failed_match {
> +       struct list_head node;
> +       const char *expectation_text;
> +       struct kunit_matcher_result *matcher_list;

Minor nitpick: this code could use some const sprinkling.

> +       size_t matcher_list_len;
> +};
> +
> +void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
> +                                   struct kunit_stream *stream);
> +
> +struct kunit_mock_no_match {
> +       struct kunit_mock_assert assert;
> +       struct kunit_mock_declaration declaration;
> +       struct list_head failed_match_list;
> +};
> +
> +void kunit_mock_no_match_format(struct kunit_assert *assert,
> +                               struct kunit_stream *stream);
> +
> +#endif /*  _KUNIT_ASSERT_H */
> diff --git a/kunit/assert.c b/kunit/assert.c
> new file mode 100644
> index 0000000000000..75bb6922a994e
> --- /dev/null
> +++ b/kunit/assert.c
> @@ -0,0 +1,179 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Assertion and expectation serialization API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +#include <kunit/assert.h>
> +
> +void kunit_base_assert_format(struct kunit_assert *assert,
> +                             struct kunit_stream *stream)
> +{
> +       const char *expect_or_assert;
> +
> +       if (assert->type == KUNIT_EXPECTATION)
> +               expect_or_assert = "EXPECTATION";
> +       else
> +               expect_or_assert = "ASSERTION";

Make this is a switch statement so we can have the compiler complain if
an enum is missing.

> +
> +       kunit_stream_add(stream, "%s FAILED at %s:%s\n",
> +                        expect_or_assert, assert->file, assert->line);
> +}
> +
> +void kunit_assert_print_msg(struct kunit_assert *assert,
> +                           struct kunit_stream *stream)
> +{
> +       if (assert->message.fmt)
> +               kunit_stream_add(stream, "\n%pV", &assert->message);
> +}
> +
[...]
> +
> +void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
> +                                   struct kunit_stream *stream)
> +{
> +       struct kunit_matcher_result *result;
> +       size_t i;
> +
> +       kunit_stream_add(stream,
> +                        "Tried expectation: %s, but\n",
> +                        match->expectation_text);
> +       for (i = 0; i < match->matcher_list_len; i++) {
> +               result = &match->matcher_list[i];
> +               kunit_stream_add(stream, "\t");
> +               result->assert.format(&result->assert, stream);
> +               kunit_stream_add(stream, "\n");
> +       }

What's the calling context of the assertions and expectations? I still
don't like the fact that string stream needs to allocate buffers and
throw them into a list somewhere because the calling context matters
there. I'd prefer we just wrote directly to the console/log via printk
instead. That way things are simple because we use the existing
buffering path of printk, but maybe there's some benefit to the string
stream that I don't see? Right now it looks like it builds a string and
then dumps it to printk so I'm sort of lost what the benefit is over
just writing directly with printk.

Maybe it's this part that you wrote up above?

> > Nevertheless, I think the debate over the usefulness of the
> > string_stream and kunit_stream are separate topics. Even if we made
> > kunit_stream more structured, I am pretty sure I would want to use
> > string_stream or some variation for constructing the message.

Why do we need string_stream to construct the message? Can't we just
print it as we process it?


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-22 20:03                   ` Stephen Boyd
@ 2019-07-22 22:30                     ` Brendan Higgins
  2019-07-22 23:54                       ` Stephen Boyd
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-22 22:30 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-18 17:08:34)
> > On Thu, Jul 18, 2019 at 12:22:33PM -0700, Brendan Higgins wrote:
> >
> > I started poking around with your suggestion while we are waiting. A
> > couple early observations:
> >
> > 1) It is actually easier to do than I previously thought and will probably
> >    help with getting more of the planned TAP output stuff working.
> >
> >    That being said, this is still a pretty substantial undertaking and
> >    will likely take *at least* a week to implement and properly review.
> >    Assuming everything goes extremely well (no unexpected issues on my
> >    end, very responsive reviewers, etc).
> >
> > 2) It *will* eliminate the need for kunit_stream.
> >
> > 3) ...but, it *will not* eliminate the need for string_stream.
> >
> > Based on my early observations, I do think it is worth doing, but I
> > don't think it is worth trying to make it in this patchset (unless I
> > have already missed the window, or it is going to be open for a while):
>
> The merge window is over. Typically code needs to be settled a few weeks
> before it opens (i.e. around -rc4 or -rc5) for most maintainers to pick
> up patches for the next merge window.

Yeah, it closed on Sunday, right?

I thought we might be able to squeak in since it was *mostly* settled,
and Shuah sent me an email two weeks ago which I interpreted to mean
she was still willing to take it.

In any case, it doesn't matter now.

> > I do think it will make things much cleaner, but I don't think it will
> > achieve your desired goal of getting rid of an unstructured
> > {kunit|string}_stream style interface; it just adds a layer on top of it
> > that makes it harder to misuse.
>
> Ok.
>
> >
> > I attached a patch of what I have so far at the end of this email so you
> > can see what I am talking about. And of course, if you agree with my
> > assessment, so we can start working on it as a future patch.
> >
> > A couple things in regard to the patch I attached:
> >
> > 1) I wrote it pretty quickly so there are almost definitely mistakes.
> >    You should consider it RFC. I did verify it compiles though.
> >
> > 2) Also, I did use kunit_stream in writing it: all occurences should be
> >    pretty easy to replace with string_stream; nevertheless, the reason
> >    for this is just to make it easier to play with the current APIs. I
> >    wanted to have something working before I went through a big tedious
> >    refactoring. So sorry if it causes any confusion.
> >
> > 3) I also based the patch on all the KUnit patches I have queued up
> >    (includes things like mocking and such) since I want to see how this
> >    serialization thing will work with mocks and matchers and things like
> >    that.
>
> Great!
>
> >
> > From 53d475d3d56afcf92b452c6d347dbedfa1a17d34 Mon Sep 17 00:00:00 2001
> > From: Brendan Higgins <brendanhiggins@google.com>
> > Date: Thu, 18 Jul 2019 16:08:52 -0700
> > Subject: [PATCH v1] DO NOT MERGE: started playing around with the
> >  serialization api
> >
> > ---
> >  include/kunit/assert.h | 130 ++++++++++++++++++++++++++++++
> >  include/kunit/mock.h   |   4 +
> >  kunit/Makefile         |   3 +-
> >  kunit/assert.c         | 179 +++++++++++++++++++++++++++++++++++++++++
> >  kunit/mock.c           |   6 +-
> >  5 files changed, 318 insertions(+), 4 deletions(-)
> >  create mode 100644 include/kunit/assert.h
> >  create mode 100644 kunit/assert.c
> >
> > diff --git a/include/kunit/assert.h b/include/kunit/assert.h
> > new file mode 100644
> > index 0000000000000..e054fdff4642f
> > --- /dev/null
> > +++ b/include/kunit/assert.h
> > @@ -0,0 +1,130 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Assertion and expectation serialization API.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#ifndef _KUNIT_ASSERT_H
> > +#define _KUNIT_ASSERT_H
> > +
> > +#include <kunit/test.h>
> > +#include <kunit/mock.h>
> > +
> > +enum kunit_assert_type {
> > +       KUNIT_ASSERTION,
> > +       KUNIT_EXPECTATION,
> > +};
> > +
> > +struct kunit_assert {
> > +       enum kunit_assert_type type;
> > +       const char *line;
> > +       const char *file;
> > +       struct va_format message;
> > +       void (*format)(struct kunit_assert *assert,
> > +                      struct kunit_stream *stream);
>
> Would passing in the test help too?

Yeah, it would probably be good to put one in `struct kunit_assert`.

> > +};
> > +
> > +void kunit_base_assert_format(struct kunit_assert *assert,
> > +                             struct kunit_stream *stream);
> > +
> > +void kunit_assert_print_msg(struct kunit_assert *assert,
> > +                           struct kunit_stream *stream);
> > +
> > +struct kunit_unary_assert {
> > +       struct kunit_assert assert;
> > +       const char *condition;
> > +       bool expected_true;
> > +};
> > +
> > +void kunit_unary_assert_format(struct kunit_assert *assert,
> > +                              struct kunit_stream *stream);
> > +
> > +struct kunit_ptr_not_err_assert {
> > +       struct kunit_assert assert;
> > +       const char *text;
> > +       void *value;
> > +};
> > +
> > +void kunit_ptr_not_err_assert_format(struct kunit_assert *assert,
> > +                                    struct kunit_stream *stream);
> > +
> > +struct kunit_binary_assert {
> > +       struct kunit_assert assert;
> > +       const char *operation;
> > +       const char *left_text;
> > +       long long left_value;
> > +       const char *right_text;
> > +       long long right_value;
> > +};
> > +
> > +void kunit_binary_assert_format(struct kunit_assert *assert,
> > +                               struct kunit_stream *stream);
> > +
> > +struct kunit_binary_ptr_assert {
> > +       struct kunit_assert assert;
> > +       const char *operation;
> > +       const char *left_text;
> > +       void *left_value;
> > +       const char *right_text;
> > +       void *right_value;
> > +};
> > +
> > +void kunit_binary_ptr_assert_format(struct kunit_assert *assert,
> > +                                   struct kunit_stream *stream);
> > +
> > +struct kunit_binary_str_assert {
> > +       struct kunit_assert assert;
> > +       const char *operation;
> > +       const char *left_text;
> > +       const char *left_value;
> > +       const char *right_text;
> > +       const char *right_value;
> > +};
> > +
> > +void kunit_binary_str_assert_format(struct kunit_assert *assert,
> > +                                   struct kunit_stream *stream);
> > +
> > +struct kunit_mock_assert {
> > +       struct kunit_assert assert;
> > +};
> > +
> > +struct kunit_mock_no_expectations {
> > +       struct kunit_mock_assert assert;
> > +};
>
> What's the purpose of making a wrapper struct with no other members?
> Just to make a different struct for some sort of type checking? I guess
> it's OK but I don't think it will be very useful in practice.

Yeah, just for typing purposes. I don't mind integrating this into the
current patchset and then deciding if we want it or not.

> > +
> > +struct kunit_mock_declaration {
> > +       const char *function_name;
> > +       const char **type_names;
> > +       const void **params;
> > +       int len;
> > +};
> > +
> > +void kunit_mock_declaration_format(struct kunit_mock_declaration *declaration,
> > +                                  struct kunit_stream *stream);
> > +
> > +struct kunit_matcher_result {
> > +       struct kunit_assert assert;
> > +};
> > +
> > +struct kunit_mock_failed_match {
> > +       struct list_head node;
> > +       const char *expectation_text;
> > +       struct kunit_matcher_result *matcher_list;
>
> Minor nitpick: this code could use some const sprinkling.

Will do.

> > +       size_t matcher_list_len;
> > +};
> > +
> > +void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
> > +                                   struct kunit_stream *stream);
> > +
> > +struct kunit_mock_no_match {
> > +       struct kunit_mock_assert assert;
> > +       struct kunit_mock_declaration declaration;
> > +       struct list_head failed_match_list;
> > +};
> > +
> > +void kunit_mock_no_match_format(struct kunit_assert *assert,
> > +                               struct kunit_stream *stream);
> > +
> > +#endif /*  _KUNIT_ASSERT_H */
> > diff --git a/kunit/assert.c b/kunit/assert.c
> > new file mode 100644
> > index 0000000000000..75bb6922a994e
> > --- /dev/null
> > +++ b/kunit/assert.c
> > @@ -0,0 +1,179 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Assertion and expectation serialization API.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +#include <kunit/assert.h>
> > +
> > +void kunit_base_assert_format(struct kunit_assert *assert,
> > +                             struct kunit_stream *stream)
> > +{
> > +       const char *expect_or_assert;
> > +
> > +       if (assert->type == KUNIT_EXPECTATION)
> > +               expect_or_assert = "EXPECTATION";
> > +       else
> > +               expect_or_assert = "ASSERTION";
>
> Make this is a switch statement so we can have the compiler complain if
> an enum is missing.

Nice call! I didn't know the compiler warned about that. Will fix.

> > +
> > +       kunit_stream_add(stream, "%s FAILED at %s:%s\n",
> > +                        expect_or_assert, assert->file, assert->line);
> > +}
> > +
> > +void kunit_assert_print_msg(struct kunit_assert *assert,
> > +                           struct kunit_stream *stream)
> > +{
> > +       if (assert->message.fmt)
> > +               kunit_stream_add(stream, "\n%pV", &assert->message);
> > +}
> > +
> [...]
> > +
> > +void kunit_mock_failed_match_format(struct kunit_mock_failed_match *match,
> > +                                   struct kunit_stream *stream)
> > +{
> > +       struct kunit_matcher_result *result;
> > +       size_t i;
> > +
> > +       kunit_stream_add(stream,
> > +                        "Tried expectation: %s, but\n",
> > +                        match->expectation_text);
> > +       for (i = 0; i < match->matcher_list_len; i++) {
> > +               result = &match->matcher_list[i];
> > +               kunit_stream_add(stream, "\t");
> > +               result->assert.format(&result->assert, stream);
> > +               kunit_stream_add(stream, "\n");
> > +       }
>
> What's the calling context of the assertions and expectations? I still
> don't like the fact that string stream needs to allocate buffers and
> throw them into a list somewhere because the calling context matters
> there.

The calling context is the same as before, which is anywhere.

> I'd prefer we just wrote directly to the console/log via printk
> instead. That way things are simple because we use the existing
> buffering path of printk, but maybe there's some benefit to the string
> stream that I don't see? Right now it looks like it builds a string and
> then dumps it to printk so I'm sort of lost what the benefit is over
> just writing directly with printk.

It's just buffering it so the whole string gets printed uninterrupted.
If we were to print out piecemeal to printk, couldn't we have another
call to printk come in causing it to garble the KUnit message we are
in the middle of printing?

> Maybe it's this part that you wrote up above?
>
> > > Nevertheless, I think the debate over the usefulness of the
> > > string_stream and kunit_stream are separate topics. Even if we made
> > > kunit_stream more structured, I am pretty sure I would want to use
> > > string_stream or some variation for constructing the message.
>
> Why do we need string_stream to construct the message? Can't we just
> print it as we process it?

See preceding comment.

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-22 22:30                     ` Brendan Higgins
@ 2019-07-22 23:54                       ` Stephen Boyd
  2019-07-23  0:32                         ` Brendan Higgins
  2019-07-24  7:31                         ` Petr Mladek
  0 siblings, 2 replies; 57+ messages in thread
From: Stephen Boyd @ 2019-07-22 23:54 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

Quoting Brendan Higgins (2019-07-22 15:30:49)
> On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> >
> > What's the calling context of the assertions and expectations? I still
> > don't like the fact that string stream needs to allocate buffers and
> > throw them into a list somewhere because the calling context matters
> > there.
> 
> The calling context is the same as before, which is anywhere.

Ok. That's concerning then.

> 
> > I'd prefer we just wrote directly to the console/log via printk
> > instead. That way things are simple because we use the existing
> > buffering path of printk, but maybe there's some benefit to the string
> > stream that I don't see? Right now it looks like it builds a string and
> > then dumps it to printk so I'm sort of lost what the benefit is over
> > just writing directly with printk.
> 
> It's just buffering it so the whole string gets printed uninterrupted.
> If we were to print out piecemeal to printk, couldn't we have another
> call to printk come in causing it to garble the KUnit message we are
> in the middle of printing?

Yes, printing piecemeal by calling printk many times could lead to
interleaving of messages if something else comes in such as an interrupt
printing something. Printk has some support to hold "records" but I'm
not sure how that would work here because KERN_CONT talks about only
being used early on in boot code. I haven't looked at printk in detail
though so maybe I'm all wrong and KERN_CONT just works?

Can printk be called once with whatever is in the struct? Otherwise if
this is about making printk into a structured log then maybe printk
isn't the proper solution anyway. Maybe a dev interface should be used
instead that can handle starting and stopping tests (via ioctl) in
addition to reading test results, records, etc. with read() and a
clearing of the records. Then the seqfile API works naturally. All of
this is a bit premature, but it looks like you're going down the path of
making something akin to ftrace that stores binary formatted
assertion/expectation records in a lockless ring buffer that then
formats those records when the user asks for them.

I can imagine someone wanting to write unit tests that check conditions
from a simulated hardirq context via irq works (a driver mock
framework?), so this doesn't seem far off.


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-22 23:54                       ` Stephen Boyd
@ 2019-07-23  0:32                         ` Brendan Higgins
  2019-07-24  7:31                         ` Petr Mladek
  1 sibling, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-07-23  0:32 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Frank Rowand, Greg KH, Josh Poimboeuf, Kees Cook, Kieran Bingham,
	Luis Chamberlain, Peter Zijlstra, Rob Herring, shuah,
	Theodore Ts'o, Masahiro Yamada, devicetree, dri-devel,
	kunit-dev, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK,
	linux-nvdimm, linux-um, Sasha Levin, Bird, Timothy,
	Amir Goldstein, Dan Carpenter, Daniel Vetter, Jeff Dike,
	Joel Stanley, Julia Lawall, Kevin Hilman, Knut Omang,
	Logan Gunthorpe, Michael Ellerman, Petr Mladek, Randy Dunlap,
	Richard Weinberger, David Rientjes, Steven Rostedt, wfg

On Mon, Jul 22, 2019 at 4:54 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-07-22 15:30:49)
> > On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > >
> > > What's the calling context of the assertions and expectations? I still
> > > don't like the fact that string stream needs to allocate buffers and
> > > throw them into a list somewhere because the calling context matters
> > > there.
> >
> > The calling context is the same as before, which is anywhere.
>
> Ok. That's concerning then.

Yeah. Luis suggested just not supporting the IRQ context until later.
See my later comment.

> > > I'd prefer we just wrote directly to the console/log via printk
> > > instead. That way things are simple because we use the existing
> > > buffering path of printk, but maybe there's some benefit to the string
> > > stream that I don't see? Right now it looks like it builds a string and
> > > then dumps it to printk so I'm sort of lost what the benefit is over
> > > just writing directly with printk.
> >
> > It's just buffering it so the whole string gets printed uninterrupted.
> > If we were to print out piecemeal to printk, couldn't we have another
> > call to printk come in causing it to garble the KUnit message we are
> > in the middle of printing?
>
> Yes, printing piecemeal by calling printk many times could lead to
> interleaving of messages if something else comes in such as an interrupt
> printing something. Printk has some support to hold "records" but I'm
> not sure how that would work here because KERN_CONT talks about only
> being used early on in boot code. I haven't looked at printk in detail
> though so maybe I'm all wrong and KERN_CONT just works?

It says KERN_CONT is not SMP safe, and it isn't supposed to contain
newlines, so it doesn't sound like it does any buffering for you. I
looked at it a while ago and those comments agreed with my
understanding of the code, but I could be wrong.

> Can printk be called once with whatever is in the struct?

Unfortunately, no. That is part of what I was trying to illustrate
with this patch. Most of the messages are deterministic, but
hardcoding all the possible message types would lead to a massive
number of hard coded strings. However, even this would break down for
the mocking formatters. All the different ways a function can be
called are just too complex to encode into a finite set of hard coded
fmt strings.

> Otherwise if
> this is about making printk into a structured log then maybe printk
> isn't the proper solution anyway. Maybe a dev interface should be used
> instead that can handle starting and stopping tests (via ioctl) in
> addition to reading test results, records, etc. with read() and a
> clearing of the records. Then the seqfile API works naturally. All of

Ehhh...I wouldn't mind providing such an interface, but I would really
like to be able to provide the results without having to depend on a
userland doing something to get test results. That has always been a
pretty important goal for me.

> this is a bit premature, but it looks like you're going down the path of
> making something akin to ftrace that stores binary formatted
> assertion/expectation records in a lockless ring buffer that then
> formats those records when the user asks for them.

Like you said, I think it is a bit premature to go that far.

In anycase, I don't see a way to get rid of string_stream, without
significantly sacrificing usability.

> I can imagine someone wanting to write unit tests that check conditions
> from a simulated hardirq context via irq works (a driver mock
> framework?), so this doesn't seem far off.

Yep, I actually presented the first pieces of that in the RFC v1 that
I linked to you earlier in this discussion. I have a more fleshed out
example here:

https://kunit.googlesource.com/linux/+/e10484ad2f9fc7926412ec84739fe105981b4771/drivers/i2c/busses/i2c-aspeed-test.c

I actually already have some people at Google playing around with it.
So yeah, not far off at all! However, in these cases we are not
actually running in the IRQ context (despite the fact that we are
testing IRQ code) because we provide a fake IRQ chip, or some other
fake mechanism that triggers the IRQ. Still, I could see someone
wanting to do it in a non-fake-IRQ context.

Luis' suggestion was just to hold off on the IRQ safe stuff at the
outset, since that is going to require a lot more effort to review. I
know that's kind of the future coding argument again, but maybe the
answer will be to just restrict what features an IRQ user has access
to (maybe just really simple expectations, for example). I mean, we
will probably have to restrict what they are allowed to use anyway.

Luis, do you have any ideas?

Cheers

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-22 23:54                       ` Stephen Boyd
  2019-07-23  0:32                         ` Brendan Higgins
@ 2019-07-24  7:31                         ` Petr Mladek
  2019-07-25 20:21                           ` Brendan Higgins
  1 sibling, 1 reply; 57+ messages in thread
From: Petr Mladek @ 2019-07-24  7:31 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Brendan Higgins, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, devicetree,
	open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
> Quoting Brendan Higgins (2019-07-22 15:30:49)
> > On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > >
> > > What's the calling context of the assertions and expectations? I still
> > > don't like the fact that string stream needs to allocate buffers and
> > > throw them into a list somewhere because the calling context matters
> > > there.
> > 
> > The calling context is the same as before, which is anywhere.
> 
> Ok. That's concerning then.
> 
> > 
> > > I'd prefer we just wrote directly to the console/log via printk
> > > instead. That way things are simple because we use the existing
> > > buffering path of printk, but maybe there's some benefit to the string
> > > stream that I don't see? Right now it looks like it builds a string and
> > > then dumps it to printk so I'm sort of lost what the benefit is over
> > > just writing directly with printk.
> > 
> > It's just buffering it so the whole string gets printed uninterrupted.
> > If we were to print out piecemeal to printk, couldn't we have another
> > call to printk come in causing it to garble the KUnit message we are
> > in the middle of printing?
> 
> Yes, printing piecemeal by calling printk many times could lead to
> interleaving of messages if something else comes in such as an interrupt
> printing something. Printk has some support to hold "records" but I'm
> not sure how that would work here because KERN_CONT talks about only
> being used early on in boot code. I haven't looked at printk in detail
> though so maybe I'm all wrong and KERN_CONT just works?

KERN_CONT does not guarantee that the message will get printed
together. The pieces get interleaved with messages printed in
parallel.

Note that KERN_CONT was originally really meant to be used only during
boot. It was later used more widely and ended in the best effort category.

There were several attempts to make it more reliable. But it was
always either too complicated or error prone or both.

You need to use your own buffering if you rely want perfect output.
The question is if it is really worth the complexity. Also note that
any buffering reduces the chance that the messages will reach
the console.

BTW: There is a work in progress on a lockless printk ring buffer.
It will make printk() more secure regarding deadlocks. But it might
make transparent handling of continuous lines even more tricky.

I guess that local buffering, before calling printk(), will be
even more important then. Well, it might really force us to create
an API for it.


> Can printk be called once with whatever is in the struct? Otherwise if
> this is about making printk into a structured log then maybe printk
> isn't the proper solution anyway. Maybe a dev interface should be used
> instead that can handle starting and stopping tests (via ioctl) in
> addition to reading test results, records, etc. with read() and a
> clearing of the records. Then the seqfile API works naturally. All of
> this is a bit premature, but it looks like you're going down the path of
> making something akin to ftrace that stores binary formatted
> assertion/expectation records in a lockless ring buffer that then
> formats those records when the user asks for them.

IMHO, ftrace postpones the text formatting primary because it does not
not want to slow down the traced code more than necessary. It is yet
another layer and there should be some strong reason for it.

> I can imagine someone wanting to write unit tests that check conditions
> from a simulated hardirq context via irq works (a driver mock
> framework?), so this doesn't seem far off.

Note that stroring the messages into the printk log is basically safe in any
context. It uses temporary per-CPU buffers for recursive messages and
in NMI. The only problem is panic() when some CPU gets stuck with the
lock taken. This will get solved by the lockless ringbuffer. Also
the temporary buffers will not be necessary any longer.

Much bigger problems are with consoles. There are many of them. It
means a lot of code and more locks involved, including scheduler
locks. Note that console lock is a semaphore.

Best Regards,
Petr

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-24  7:31                         ` Petr Mladek
@ 2019-07-25 20:21                           ` Brendan Higgins
  2019-07-26  8:31                             ` Petr Mladek
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-07-25 20:21 UTC (permalink / raw)
  To: Petr Mladek
  Cc: Stephen Boyd, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, devicetree,
	open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Wed, Jul 24, 2019 at 12:31 AM Petr Mladek <pmladek@suse.com> wrote:
>
> On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
> > Quoting Brendan Higgins (2019-07-22 15:30:49)
> > > On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > >
> > > >
> > > > What's the calling context of the assertions and expectations? I still
> > > > don't like the fact that string stream needs to allocate buffers and
> > > > throw them into a list somewhere because the calling context matters
> > > > there.
> > >
> > > The calling context is the same as before, which is anywhere.
> >
> > Ok. That's concerning then.
> >
> > >
> > > > I'd prefer we just wrote directly to the console/log via printk
> > > > instead. That way things are simple because we use the existing
> > > > buffering path of printk, but maybe there's some benefit to the string
> > > > stream that I don't see? Right now it looks like it builds a string and
> > > > then dumps it to printk so I'm sort of lost what the benefit is over
> > > > just writing directly with printk.
> > >
> > > It's just buffering it so the whole string gets printed uninterrupted.
> > > If we were to print out piecemeal to printk, couldn't we have another
> > > call to printk come in causing it to garble the KUnit message we are
> > > in the middle of printing?
> >
> > Yes, printing piecemeal by calling printk many times could lead to
> > interleaving of messages if something else comes in such as an interrupt
> > printing something. Printk has some support to hold "records" but I'm
> > not sure how that would work here because KERN_CONT talks about only
> > being used early on in boot code. I haven't looked at printk in detail
> > though so maybe I'm all wrong and KERN_CONT just works?
>
> KERN_CONT does not guarantee that the message will get printed
> together. The pieces get interleaved with messages printed in
> parallel.
>
> Note that KERN_CONT was originally really meant to be used only during
> boot. It was later used more widely and ended in the best effort category.
>
> There were several attempts to make it more reliable. But it was
> always either too complicated or error prone or both.
>
> You need to use your own buffering if you rely want perfect output.
> The question is if it is really worth the complexity. Also note that
> any buffering reduces the chance that the messages will reach
> the console.

Seems like that settles it then. Thanks!

> BTW: There is a work in progress on a lockless printk ring buffer.
> It will make printk() more secure regarding deadlocks. But it might
> make transparent handling of continuous lines even more tricky.
>
> I guess that local buffering, before calling printk(), will be
> even more important then. Well, it might really force us to create
> an API for it.

Cool! Can you CC me on that discussion?

> > Can printk be called once with whatever is in the struct? Otherwise if
> > this is about making printk into a structured log then maybe printk
> > isn't the proper solution anyway. Maybe a dev interface should be used
> > instead that can handle starting and stopping tests (via ioctl) in
> > addition to reading test results, records, etc. with read() and a
> > clearing of the records. Then the seqfile API works naturally. All of
> > this is a bit premature, but it looks like you're going down the path of
> > making something akin to ftrace that stores binary formatted
> > assertion/expectation records in a lockless ring buffer that then
> > formats those records when the user asks for them.
>
> IMHO, ftrace postpones the text formatting primary because it does not
> not want to slow down the traced code more than necessary. It is yet
> another layer and there should be some strong reason for it.

Noted. Yeah, I would prefer avoiding printing out the info at a separate time.

> > I can imagine someone wanting to write unit tests that check conditions
> > from a simulated hardirq context via irq works (a driver mock
> > framework?), so this doesn't seem far off.
>
> Note that stroring the messages into the printk log is basically safe in any
> context. It uses temporary per-CPU buffers for recursive messages and
> in NMI. The only problem is panic() when some CPU gets stuck with the
> lock taken. This will get solved by the lockless ringbuffer. Also
> the temporary buffers will not be necessary any longer.

Sure, I think Stephen's concern is all the supporting code that is
involved. Not printk specifically. It just means a lot more of KUnit
has to be IRQ safe.

> Much bigger problems are with consoles. There are many of them. It
> means a lot of code and more locks involved, including scheduler
> locks. Note that console lock is a semaphore.

That shouldn't affect us though, right? As long as we continue to use
the printk interface?

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-25 20:21                           ` Brendan Higgins
@ 2019-07-26  8:31                             ` Petr Mladek
  2019-08-01 18:55                               ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Petr Mladek @ 2019-07-26  8:31 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Jeff Dike, Kevin Hilman, Logan Gunthorpe, Michael Ellerman,
	Daniel Vetter, Amir Goldstein, Frank Rowand, Steven Rostedt,
	Kees Cook, David Rientjes, kunit-dev, Kieran Bingham,
	Peter Zijlstra, Randy Dunlap, Joel Stanley, Luis Chamberlain,
	Rob Herring, Stephen Boyd, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, John Ogness,
	devicetree, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Thu 2019-07-25 13:21:12, Brendan Higgins wrote:
> On Wed, Jul 24, 2019 at 12:31 AM Petr Mladek <pmladek@suse.com> wrote:
> >
> > On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
> > > Quoting Brendan Higgins (2019-07-22 15:30:49)
> > > > On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > > >
> > > > >
> > > > > What's the calling context of the assertions and expectations? I still
> > > > > don't like the fact that string stream needs to allocate buffers and
> > > > > throw them into a list somewhere because the calling context matters
> > > > > there.
> > > >
> > > > The calling context is the same as before, which is anywhere.
> > >
> > > Ok. That's concerning then.
> > >
> > > >
> > > > > I'd prefer we just wrote directly to the console/log via printk
> > > > > instead. That way things are simple because we use the existing
> > > > > buffering path of printk, but maybe there's some benefit to the string
> > > > > stream that I don't see? Right now it looks like it builds a string and
> > > > > then dumps it to printk so I'm sort of lost what the benefit is over
> > > > > just writing directly with printk.
> > > >
> > > > It's just buffering it so the whole string gets printed uninterrupted.
> > > > If we were to print out piecemeal to printk, couldn't we have another
> > > > call to printk come in causing it to garble the KUnit message we are
> > > > in the middle of printing?
> > >
> > > Yes, printing piecemeal by calling printk many times could lead to
> > > interleaving of messages if something else comes in such as an interrupt
> > > printing something. Printk has some support to hold "records" but I'm
> > > not sure how that would work here because KERN_CONT talks about only
> > > being used early on in boot code. I haven't looked at printk in detail
> > > though so maybe I'm all wrong and KERN_CONT just works?
> >
> > KERN_CONT does not guarantee that the message will get printed
> > together. The pieces get interleaved with messages printed in
> > parallel.
> >
> > Note that KERN_CONT was originally really meant to be used only during
> > boot. It was later used more widely and ended in the best effort category.
> >
> > There were several attempts to make it more reliable. But it was
> > always either too complicated or error prone or both.
> >
> > You need to use your own buffering if you rely want perfect output.
> > The question is if it is really worth the complexity. Also note that
> > any buffering reduces the chance that the messages will reach
> > the console.
> 
> Seems like that settles it then. Thanks!
> 
> > BTW: There is a work in progress on a lockless printk ring buffer.
> > It will make printk() more secure regarding deadlocks. But it might
> > make transparent handling of continuous lines even more tricky.
> >
> > I guess that local buffering, before calling printk(), will be
> > even more important then. Well, it might really force us to create
> > an API for it.
> 
> Cool! Can you CC me on that discussion?

Adding John Oggness into CC.

John, please CC Brendan Higgins on the patchsets eventually switching
printk() into the lockless buffer. The test framework is going to
do its own buffering to keep the related messages together.

The lockless ringbuffer might make handling of related (partial)
lines worse or better. It might justify KUnit's extra buffering
or it might allow to get rid of it.

> > Note that stroring the messages into the printk log is basically safe in any
> > context. It uses temporary per-CPU buffers for recursive messages and
> > in NMI. The only problem is panic() when some CPU gets stuck with the
> > lock taken. This will get solved by the lockless ringbuffer. Also
> > the temporary buffers will not be necessary any longer.
> 
> Sure, I think Stephen's concern is all the supporting code that is
> involved. Not printk specifically. It just means a lot more of KUnit
> has to be IRQ safe.

I see.

BTW: I wonder if KUnit could reuse the existing seq_buf implementation
for buffering messages.

I am sorry if it has already been proposed and rejected for some
reason. I might have missed it. Feel free to just point me to
same older mail.

> > Much bigger problems are with consoles. There are many of them. It
> > means a lot of code and more locks involved, including scheduler
> > locks. Note that console lock is a semaphore.
> 
> That shouldn't affect us though, right? As long as we continue to use
> the printk interface?

I guess that it should not affect KUnit.

The only problem might be if the testing framework calls printk()
inside scheduler or console code. And only when the tested code
uses the same locks that will be used by the called printk().

To be honest I do not fully understand KUnit design. I am not
completely sure how the tested code is isolated from the running
system. Namely, I do not know if the tested code shares
the same locks with the system running the test.

Best Regards,
Petr

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-07-26  8:31                             ` Petr Mladek
@ 2019-08-01 18:55                               ` Brendan Higgins
  2019-08-01 18:59                                 ` Brendan Higgins
  2019-08-02  7:37                                 ` John Ogness
  0 siblings, 2 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-08-01 18:55 UTC (permalink / raw)
  To: Petr Mladek
  Cc: Jeff Dike, Kevin Hilman, Logan Gunthorpe, Michael Ellerman,
	Daniel Vetter, Amir Goldstein, Frank Rowand, Steven Rostedt,
	Kees Cook, David Rientjes, kunit-dev, Kieran Bingham,
	Peter Zijlstra, Randy Dunlap, Joel Stanley, Luis Chamberlain,
	Rob Herring, Stephen Boyd, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, John Ogness,
	devicetree, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
>
> On Thu 2019-07-25 13:21:12, Brendan Higgins wrote:
> > On Wed, Jul 24, 2019 at 12:31 AM Petr Mladek <pmladek@suse.com> wrote:
> > >
> > > On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
> > > > Quoting Brendan Higgins (2019-07-22 15:30:49)
> > > > > On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > > > >
> > > > > >
> > > > > > What's the calling context of the assertions and expectations? I still
> > > > > > don't like the fact that string stream needs to allocate buffers and
> > > > > > throw them into a list somewhere because the calling context matters
> > > > > > there.
> > > > >
> > > > > The calling context is the same as before, which is anywhere.
> > > >
> > > > Ok. That's concerning then.
> > > >
> > > > >
> > > > > > I'd prefer we just wrote directly to the console/log via printk
> > > > > > instead. That way things are simple because we use the existing
> > > > > > buffering path of printk, but maybe there's some benefit to the string
> > > > > > stream that I don't see? Right now it looks like it builds a string and
> > > > > > then dumps it to printk so I'm sort of lost what the benefit is over
> > > > > > just writing directly with printk.
> > > > >
> > > > > It's just buffering it so the whole string gets printed uninterrupted.
> > > > > If we were to print out piecemeal to printk, couldn't we have another
> > > > > call to printk come in causing it to garble the KUnit message we are
> > > > > in the middle of printing?
> > > >
> > > > Yes, printing piecemeal by calling printk many times could lead to
> > > > interleaving of messages if something else comes in such as an interrupt
> > > > printing something. Printk has some support to hold "records" but I'm
> > > > not sure how that would work here because KERN_CONT talks about only
> > > > being used early on in boot code. I haven't looked at printk in detail
> > > > though so maybe I'm all wrong and KERN_CONT just works?
> > >
> > > KERN_CONT does not guarantee that the message will get printed
> > > together. The pieces get interleaved with messages printed in
> > > parallel.
> > >
> > > Note that KERN_CONT was originally really meant to be used only during
> > > boot. It was later used more widely and ended in the best effort category.
> > >
> > > There were several attempts to make it more reliable. But it was
> > > always either too complicated or error prone or both.
> > >
> > > You need to use your own buffering if you rely want perfect output.
> > > The question is if it is really worth the complexity. Also note that
> > > any buffering reduces the chance that the messages will reach
> > > the console.
> >
> > Seems like that settles it then. Thanks!
> >
> > > BTW: There is a work in progress on a lockless printk ring buffer.
> > > It will make printk() more secure regarding deadlocks. But it might
> > > make transparent handling of continuous lines even more tricky.
> > >
> > > I guess that local buffering, before calling printk(), will be
> > > even more important then. Well, it might really force us to create
> > > an API for it.
> >
> > Cool! Can you CC me on that discussion?
>
> Adding John Oggness into CC.
>
> John, please CC Brendan Higgins on the patchsets eventually switching
> printk() into the lockless buffer. The test framework is going to
> do its own buffering to keep the related messages together.
>
> The lockless ringbuffer might make handling of related (partial)
> lines worse or better. It might justify KUnit's extra buffering
> or it might allow to get rid of it.

Thanks for CC'ing me on the printk ringbuffer thread. It looks like it
actually probably won't affect my needs for KUnit logging. The biggest
reason I need some sort of buffering system is to be able to compose
messages piece meal into a single message that will be printed out to
the user as a single message with no messages from other printk
callers printed out in the middle of mine.

The prb does look interesting; however, it appears that to get the
semantics that I need, I would have to put my entire message in a
single data block and would consequently need to know the size of my
message a priori, which is problematic. Consequently, it seems as
though I will probably need to compose my entire message using my own
buffering system.

> > > Note that stroring the messages into the printk log is basically safe in any
> > > context. It uses temporary per-CPU buffers for recursive messages and
> > > in NMI. The only problem is panic() when some CPU gets stuck with the
> > > lock taken. This will get solved by the lockless ringbuffer. Also
> > > the temporary buffers will not be necessary any longer.
> >
> > Sure, I think Stephen's concern is all the supporting code that is
> > involved. Not printk specifically. It just means a lot more of KUnit
> > has to be IRQ safe.
>
> I see.
>
> BTW: I wonder if KUnit could reuse the existing seq_buf implementation
> for buffering messages.
>
> I am sorry if it has already been proposed and rejected for some
> reason. I might have missed it. Feel free to just point me to
> same older mail.

Yeah, we discussed it briefly here:

https://lkml.org/lkml/2019/5/17/497

Looks like I forgot to include my reasoning in the commit text, sorry
about that.

> > > Much bigger problems are with consoles. There are many of them. It
> > > means a lot of code and more locks involved, including scheduler
> > > locks. Note that console lock is a semaphore.
> >
> > That shouldn't affect us though, right? As long as we continue to use
> > the printk interface?
>
> I guess that it should not affect KUnit.
>
> The only problem might be if the testing framework calls printk()
> inside scheduler or console code. And only when the tested code
> uses the same locks that will be used by the called printk().

Yeah, well printk will not be our only problem in those instances.

> To be honest I do not fully understand KUnit design. I am not
> completely sure how the tested code is isolated from the running
> system. Namely, I do not know if the tested code shares
> the same locks with the system running the test.

No worries, I don't expect printk to be the hang up in those cases. It
sounds like KUnit has a long way to evolve before printk is going to
be a limitation.

Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-08-01 18:55                               ` Brendan Higgins
@ 2019-08-01 18:59                                 ` Brendan Higgins
  2019-08-01 21:14                                   ` Stephen Boyd
  2019-08-02  7:37                                 ` John Ogness
  1 sibling, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-08-01 18:59 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Petr Mladek, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, John Ogness,
	devicetree, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Thu, Aug 1, 2019 at 11:55 AM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
> >
> > On Thu 2019-07-25 13:21:12, Brendan Higgins wrote:
> > > On Wed, Jul 24, 2019 at 12:31 AM Petr Mladek <pmladek@suse.com> wrote:
> > > >
> > > > On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
> > > > > Quoting Brendan Higgins (2019-07-22 15:30:49)
> > > > > > On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> > > > > > >
> > > > > > >
> > > > > > > What's the calling context of the assertions and expectations? I still
> > > > > > > don't like the fact that string stream needs to allocate buffers and
> > > > > > > throw them into a list somewhere because the calling context matters
> > > > > > > there.
> > > > > >
> > > > > > The calling context is the same as before, which is anywhere.
> > > > >
> > > > > Ok. That's concerning then.
> > > > >
> > > > > >
> > > > > > > I'd prefer we just wrote directly to the console/log via printk
> > > > > > > instead. That way things are simple because we use the existing
> > > > > > > buffering path of printk, but maybe there's some benefit to the string
> > > > > > > stream that I don't see? Right now it looks like it builds a string and
> > > > > > > then dumps it to printk so I'm sort of lost what the benefit is over
> > > > > > > just writing directly with printk.
> > > > > >
> > > > > > It's just buffering it so the whole string gets printed uninterrupted.
> > > > > > If we were to print out piecemeal to printk, couldn't we have another
> > > > > > call to printk come in causing it to garble the KUnit message we are
> > > > > > in the middle of printing?
> > > > >
> > > > > Yes, printing piecemeal by calling printk many times could lead to
> > > > > interleaving of messages if something else comes in such as an interrupt
> > > > > printing something. Printk has some support to hold "records" but I'm
> > > > > not sure how that would work here because KERN_CONT talks about only
> > > > > being used early on in boot code. I haven't looked at printk in detail
> > > > > though so maybe I'm all wrong and KERN_CONT just works?
> > > >
> > > > KERN_CONT does not guarantee that the message will get printed
> > > > together. The pieces get interleaved with messages printed in
> > > > parallel.
> > > >
> > > > Note that KERN_CONT was originally really meant to be used only during
> > > > boot. It was later used more widely and ended in the best effort category.
> > > >
> > > > There were several attempts to make it more reliable. But it was
> > > > always either too complicated or error prone or both.
> > > >
> > > > You need to use your own buffering if you rely want perfect output.
> > > > The question is if it is really worth the complexity. Also note that
> > > > any buffering reduces the chance that the messages will reach
> > > > the console.
> > >
> > > Seems like that settles it then. Thanks!
> > >
> > > > BTW: There is a work in progress on a lockless printk ring buffer.
> > > > It will make printk() more secure regarding deadlocks. But it might
> > > > make transparent handling of continuous lines even more tricky.
> > > >
> > > > I guess that local buffering, before calling printk(), will be
> > > > even more important then. Well, it might really force us to create
> > > > an API for it.
> > >
> > > Cool! Can you CC me on that discussion?
> >
> > Adding John Oggness into CC.
> >
> > John, please CC Brendan Higgins on the patchsets eventually switching
> > printk() into the lockless buffer. The test framework is going to
> > do its own buffering to keep the related messages together.
> >
> > The lockless ringbuffer might make handling of related (partial)
> > lines worse or better. It might justify KUnit's extra buffering
> > or it might allow to get rid of it.
>
> Thanks for CC'ing me on the printk ringbuffer thread. It looks like it
> actually probably won't affect my needs for KUnit logging. The biggest
> reason I need some sort of buffering system is to be able to compose
> messages piece meal into a single message that will be printed out to
> the user as a single message with no messages from other printk
> callers printed out in the middle of mine.
>
> The prb does look interesting; however, it appears that to get the
> semantics that I need, I would have to put my entire message in a
> single data block and would consequently need to know the size of my
> message a priori, which is problematic. Consequently, it seems as
> though I will probably need to compose my entire message using my own
> buffering system.
>
> > > > Note that stroring the messages into the printk log is basically safe in any
> > > > context. It uses temporary per-CPU buffers for recursive messages and
> > > > in NMI. The only problem is panic() when some CPU gets stuck with the
> > > > lock taken. This will get solved by the lockless ringbuffer. Also
> > > > the temporary buffers will not be necessary any longer.
> > >
> > > Sure, I think Stephen's concern is all the supporting code that is
> > > involved. Not printk specifically. It just means a lot more of KUnit
> > > has to be IRQ safe.
> >
> > I see.
> >
> > BTW: I wonder if KUnit could reuse the existing seq_buf implementation
> > for buffering messages.
> >
> > I am sorry if it has already been proposed and rejected for some
> > reason. I might have missed it. Feel free to just point me to
> > same older mail.
>
> Yeah, we discussed it briefly here:
>
> https://lkml.org/lkml/2019/5/17/497
>
> Looks like I forgot to include my reasoning in the commit text, sorry
> about that.
>
> > > > Much bigger problems are with consoles. There are many of them. It
> > > > means a lot of code and more locks involved, including scheduler
> > > > locks. Note that console lock is a semaphore.
> > >
> > > That shouldn't affect us though, right? As long as we continue to use
> > > the printk interface?
> >
> > I guess that it should not affect KUnit.
> >
> > The only problem might be if the testing framework calls printk()
> > inside scheduler or console code. And only when the tested code
> > uses the same locks that will be used by the called printk().
>
> Yeah, well printk will not be our only problem in those instances.
>
> > To be honest I do not fully understand KUnit design. I am not
> > completely sure how the tested code is isolated from the running
> > system. Namely, I do not know if the tested code shares
> > the same locks with the system running the test.
>
> No worries, I don't expect printk to be the hang up in those cases. It
> sounds like KUnit has a long way to evolve before printk is going to
> be a limitation.

So Stephen, what do you think?

Do you want me to go forward with the new kunit_assert API wrapping
the string_stream as I have it now? Would you prefer to punt this to a
later patch? Or would you prefer something else?

Cheers

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-08-01 18:59                                 ` Brendan Higgins
@ 2019-08-01 21:14                                   ` Stephen Boyd
  2019-08-01 21:43                                     ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Stephen Boyd @ 2019-08-01 21:14 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Petr Mladek, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, John Ogness,
	devicetree, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

Quoting Brendan Higgins (2019-08-01 11:59:57)
> On Thu, Aug 1, 2019 at 11:55 AM Brendan Higgins
> <brendanhiggins@google.com> wrote:
> >
> > On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
> >
> > > To be honest I do not fully understand KUnit design. I am not
> > > completely sure how the tested code is isolated from the running
> > > system. Namely, I do not know if the tested code shares
> > > the same locks with the system running the test.
> >
> > No worries, I don't expect printk to be the hang up in those cases. It
> > sounds like KUnit has a long way to evolve before printk is going to
> > be a limitation.
> 
> So Stephen, what do you think?
> 
> Do you want me to go forward with the new kunit_assert API wrapping
> the string_stream as I have it now? Would you prefer to punt this to a
> later patch? Or would you prefer something else?
> 

I like the struct based approach. If anything, it can be adjusted to
make the code throw some records into a spinlock later on and delay the
formatting of the assertion if need be. Can you resend with that
approach? I don't think I'll have any more comments after that.


^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-08-01 21:14                                   ` Stephen Boyd
@ 2019-08-01 21:43                                     ` Brendan Higgins
  2019-08-12 20:41                                       ` Brendan Higgins
  0 siblings, 1 reply; 57+ messages in thread
From: Brendan Higgins @ 2019-08-01 21:43 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Petr Mladek, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, John Ogness,
	devicetree, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Thu, Aug 1, 2019 at 2:14 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-08-01 11:59:57)
> > On Thu, Aug 1, 2019 at 11:55 AM Brendan Higgins
> > <brendanhiggins@google.com> wrote:
> > >
> > > On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
> > >
> > > > To be honest I do not fully understand KUnit design. I am not
> > > > completely sure how the tested code is isolated from the running
> > > > system. Namely, I do not know if the tested code shares
> > > > the same locks with the system running the test.
> > >
> > > No worries, I don't expect printk to be the hang up in those cases. It
> > > sounds like KUnit has a long way to evolve before printk is going to
> > > be a limitation.
> >
> > So Stephen, what do you think?
> >
> > Do you want me to go forward with the new kunit_assert API wrapping
> > the string_stream as I have it now? Would you prefer to punt this to a
> > later patch? Or would you prefer something else?
> >
>
> I like the struct based approach. If anything, it can be adjusted to
> make the code throw some records into a spinlock later on and delay the
> formatting of the assertion if need be.

That's a fair point.

> Can you resend with that
> approach? I don't think I'll have any more comments after that.

Cool, will do.

Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-08-01 18:55                               ` Brendan Higgins
  2019-08-01 18:59                                 ` Brendan Higgins
@ 2019-08-02  7:37                                 ` John Ogness
  2019-08-12 21:12                                   ` Brendan Higgins
  1 sibling, 1 reply; 57+ messages in thread
From: John Ogness @ 2019-08-02  7:37 UTC (permalink / raw)
  To: Brendan Higgins
  Cc: Petr Mladek, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, Stephen Boyd, shuah, wfg, Greg KH,
	Julia Lawall, linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, devicetree,
	open list\:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list\:KERNEL SELFTEST FRAMEWORK

On 2019-08-01, Brendan Higgins <brendanhiggins@google.com> wrote:
> On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
>> On Thu 2019-07-25 13:21:12, Brendan Higgins wrote:
>>> On Wed, Jul 24, 2019 at 12:31 AM Petr Mladek <pmladek@suse.com> wrote:
>>>> On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
>>>>> Quoting Brendan Higgins (2019-07-22 15:30:49)
>>>>>> On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
>>>>>>> What's the calling context of the assertions and expectations? I
>>>>>>> still don't like the fact that string stream needs to allocate
>>>>>>> buffers and throw them into a list somewhere because the calling
>>>>>>> context matters there.
>>>>>>
>>>>>> The calling context is the same as before, which is anywhere.
>>>>>
>>>>> Ok. That's concerning then.
>>>>>
>>>>>>> I'd prefer we just wrote directly to the console/log via printk
>>>>>>> instead. That way things are simple because we use the existing
>>>>>>> buffering path of printk, but maybe there's some benefit to the
>>>>>>> string stream that I don't see? Right now it looks like it
>>>>>>> builds a string and then dumps it to printk so I'm sort of lost
>>>>>>> what the benefit is over just writing directly with printk.
>>>>>>
>>>>>> It's just buffering it so the whole string gets printed
>>>>>> uninterrupted.  If we were to print out piecemeal to printk,
>>>>>> couldn't we have another call to printk come in causing it to
>>>>>> garble the KUnit message we are in the middle of printing?
>>>>>
>>>>> Yes, printing piecemeal by calling printk many times could lead to
>>>>> interleaving of messages if something else comes in such as an
>>>>> interrupt printing something. Printk has some support to hold
>>>>> "records" but I'm not sure how that would work here because
>>>>> KERN_CONT talks about only being used early on in boot code. I
>>>>> haven't looked at printk in detail though so maybe I'm all wrong
>>>>> and KERN_CONT just works?
>>>>
>>>> KERN_CONT does not guarantee that the message will get printed
>>>> together. The pieces get interleaved with messages printed in
>>>> parallel.
>>>>
>>>> Note that KERN_CONT was originally really meant to be used only
>>>> during boot. It was later used more widely and ended in the best
>>>> effort category.
>>>>
>>>> There were several attempts to make it more reliable. But it was
>>>> always either too complicated or error prone or both.
>>>>
>>>> You need to use your own buffering if you rely want perfect output.
>>>> The question is if it is really worth the complexity. Also note
>>>> that any buffering reduces the chance that the messages will reach
>>>> the console.
>>>
>>> Seems like that settles it then. Thanks!
>>>
>>>> BTW: There is a work in progress on a lockless printk ring buffer.
>>>> It will make printk() more secure regarding deadlocks. But it might
>>>> make transparent handling of continuous lines even more tricky.
>>>>
>>>> I guess that local buffering, before calling printk(), will be
>>>> even more important then. Well, it might really force us to create
>>>> an API for it.
>>>
>>> Cool! Can you CC me on that discussion?
>>
>> Adding John Oggness into CC.
>>
>> John, please CC Brendan Higgins on the patchsets eventually switching
>> printk() into the lockless buffer. The test framework is going to
>> do its own buffering to keep the related messages together.
>>
>> The lockless ringbuffer might make handling of related (partial)
>> lines worse or better. It might justify KUnit's extra buffering
>> or it might allow to get rid of it.
>
> Thanks for CC'ing me on the printk ringbuffer thread. It looks like it
> actually probably won't affect my needs for KUnit logging. The biggest
> reason I need some sort of buffering system is to be able to compose
> messages piece meal into a single message that will be printed out to
> the user as a single message with no messages from other printk
> callers printed out in the middle of mine.

printk has this same requirement for its CONT messages. You can read
about how I propose to implement that here[0], using a separate prb
ringbuffer for buffered storage until all the pieces are available.

It is not my goal that multiple subsystems start making use of the prb
ringbuffer. However, its features can be attractive if you don't want to
worry about multiple writers/readers or context (including NMI). Before
writing "yet another ringbuffer" [1] it might be worth the effort to at
least see if one of the existing implementations can work (or be
extended to work) for you.

John Ogness

[0] https://lkml.kernel.org/r/87imt2bl0k.fsf@linutronix.de
[1] https://lwn.net/Articles/789603/

> The prb does look interesting; however, it appears that to get the
> semantics that I need, I would have to put my entire message in a
> single data block and would consequently need to know the size of my
> message a priori, which is problematic. Consequently, it seems as
> though I will probably need to compose my entire message using my own
> buffering system.
>
>>>> Note that stroring the messages into the printk log is basically
>>>> safe in any context. It uses temporary per-CPU buffers for
>>>> recursive messages and in NMI. The only problem is panic() when
>>>> some CPU gets stuck with the lock taken. This will get solved by
>>>> the lockless ringbuffer. Also the temporary buffers will not be
>>>> necessary any longer.
>>>
>>> Sure, I think Stephen's concern is all the supporting code that is
>>> involved. Not printk specifically. It just means a lot more of KUnit
>>> has to be IRQ safe.
>>
>> I see.
>>
>> BTW: I wonder if KUnit could reuse the existing seq_buf
>> implementation for buffering messages.
>>
>> I am sorry if it has already been proposed and rejected for some
>> reason. I might have missed it. Feel free to just point me to
>> same older mail.
>
> Yeah, we discussed it briefly here:
>
> https://lkml.org/lkml/2019/5/17/497
>
> Looks like I forgot to include my reasoning in the commit text, sorry
> about that.
>
>>>> Much bigger problems are with consoles. There are many of them. It
>>>> means a lot of code and more locks involved, including scheduler
>>>> locks. Note that console lock is a semaphore.
>>>
>>> That shouldn't affect us though, right? As long as we continue to
>>> use the printk interface?
>>
>> I guess that it should not affect KUnit.
>>
>> The only problem might be if the testing framework calls printk()
>> inside scheduler or console code. And only when the tested code
>> uses the same locks that will be used by the called printk().
>
> Yeah, well printk will not be our only problem in those instances.
>
>> To be honest I do not fully understand KUnit design. I am not
>> completely sure how the tested code is isolated from the running
>> system. Namely, I do not know if the tested code shares
>> the same locks with the system running the test.
>
> No worries, I don't expect printk to be the hang up in those cases. It
> sounds like KUnit has a long way to evolve before printk is going to
> be a limitation.
>
> Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-08-01 21:43                                     ` Brendan Higgins
@ 2019-08-12 20:41                                       ` Brendan Higgins
  0 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-08-12 20:41 UTC (permalink / raw)
  To: Stephen Boyd
  Cc: Petr Mladek, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, shuah, wfg, Greg KH, Julia Lawall,
	linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, John Ogness,
	devicetree, open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Thu, Aug 1, 2019 at 2:43 PM Brendan Higgins
<brendanhiggins@google.com> wrote:
>
> On Thu, Aug 1, 2019 at 2:14 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Brendan Higgins (2019-08-01 11:59:57)
> > > On Thu, Aug 1, 2019 at 11:55 AM Brendan Higgins
> > > <brendanhiggins@google.com> wrote:
> > > >
> > > > On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
> > > >
> > > > > To be honest I do not fully understand KUnit design. I am not
> > > > > completely sure how the tested code is isolated from the running
> > > > > system. Namely, I do not know if the tested code shares
> > > > > the same locks with the system running the test.
> > > >
> > > > No worries, I don't expect printk to be the hang up in those cases. It
> > > > sounds like KUnit has a long way to evolve before printk is going to
> > > > be a limitation.
> > >
> > > So Stephen, what do you think?
> > >
> > > Do you want me to go forward with the new kunit_assert API wrapping
> > > the string_stream as I have it now? Would you prefer to punt this to a
> > > later patch? Or would you prefer something else?
> > >
> >
> > I like the struct based approach. If anything, it can be adjusted to
> > make the code throw some records into a spinlock later on and delay the
> > formatting of the assertion if need be.
>
> That's a fair point.
>
> > Can you resend with that
> > approach? I don't think I'll have any more comments after that.

I sent a new revision, v12, that incorporates the kunit_assert stuff.

Let me know what you think!

^ permalink raw reply	[flat|nested] 57+ messages in thread

* Re: [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger
  2019-08-02  7:37                                 ` John Ogness
@ 2019-08-12 21:12                                   ` Brendan Higgins
  0 siblings, 0 replies; 57+ messages in thread
From: Brendan Higgins @ 2019-08-12 21:12 UTC (permalink / raw)
  To: John Ogness
  Cc: Petr Mladek, Jeff Dike, Kevin Hilman, Logan Gunthorpe,
	Michael Ellerman, Daniel Vetter, Amir Goldstein, Frank Rowand,
	Steven Rostedt, Kees Cook, David Rientjes, kunit-dev,
	Kieran Bingham, Peter Zijlstra, Randy Dunlap, Joel Stanley,
	Luis Chamberlain, Rob Herring, Stephen Boyd, shuah, wfg, Greg KH,
	Julia Lawall, linux-nvdimm, dri-devel, linux-um, Sasha Levin,
	Theodore Ts'o, Richard Weinberger, Dan Carpenter, Knut Omang,
	Josh Poimboeuf, Masahiro Yamada, Timothy Bird, devicetree,
	open list:DOCUMENTATION, linux-fsdevel, linux-kbuild,
	Linux Kernel Mailing List, open list:KERNEL SELFTEST FRAMEWORK

On Fri, Aug 02, 2019 at 09:37:53AM +0200, John Ogness wrote:
> On 2019-08-01, Brendan Higgins <brendanhiggins@google.com> wrote:
> > On Fri, Jul 26, 2019 at 1:31 AM Petr Mladek <pmladek@suse.com> wrote:
> >> On Thu 2019-07-25 13:21:12, Brendan Higgins wrote:
> >>> On Wed, Jul 24, 2019 at 12:31 AM Petr Mladek <pmladek@suse.com> wrote:
> >>>> On Mon 2019-07-22 16:54:10, Stephen Boyd wrote:
> >>>>> Quoting Brendan Higgins (2019-07-22 15:30:49)
> >>>>>> On Mon, Jul 22, 2019 at 1:03 PM Stephen Boyd <sboyd@kernel.org> wrote:
> >>>>>>> What's the calling context of the assertions and expectations? I
> >>>>>>> still don't like the fact that string stream needs to allocate
> >>>>>>> buffers and throw them into a list somewhere because the calling
> >>>>>>> context matters there.
> >>>>>>
> >>>>>> The calling context is the same as before, which is anywhere.
> >>>>>
> >>>>> Ok. That's concerning then.
> >>>>>
> >>>>>>> I'd prefer we just wrote directly to the console/log via printk
> >>>>>>> instead. That way things are simple because we use the existing
> >>>>>>> buffering path of printk, but maybe there's some benefit to the
> >>>>>>> string stream that I don't see? Right now it looks like it
> >>>>>>> builds a string and then dumps it to printk so I'm sort of lost
> >>>>>>> what the benefit is over just writing directly with printk.
> >>>>>>
> >>>>>> It's just buffering it so the whole string gets printed
> >>>>>> uninterrupted.  If we were to print out piecemeal to printk,
> >>>>>> couldn't we have another call to printk come in causing it to
> >>>>>> garble the KUnit message we are in the middle of printing?
> >>>>>
> >>>>> Yes, printing piecemeal by calling printk many times could lead to
> >>>>> interleaving of messages if something else comes in such as an
> >>>>> interrupt printing something. Printk has some support to hold
> >>>>> "records" but I'm not sure how that would work here because
> >>>>> KERN_CONT talks about only being used early on in boot code. I
> >>>>> haven't looked at printk in detail though so maybe I'm all wrong
> >>>>> and KERN_CONT just works?
> >>>>
> >>>> KERN_CONT does not guarantee that the message will get printed
> >>>> together. The pieces get interleaved with messages printed in
> >>>> parallel.
> >>>>
> >>>> Note that KERN_CONT was originally really meant to be used only
> >>>> during boot. It was later used more widely and ended in the best
> >>>> effort category.
> >>>>
> >>>> There were several attempts to make it more reliable. But it was
> >>>> always either too complicated or error prone or both.
> >>>>
> >>>> You need to use your own buffering if you rely want perfect output.
> >>>> The question is if it is really worth the complexity. Also note
> >>>> that any buffering reduces the chance that the messages will reach
> >>>> the console.
> >>>
> >>> Seems like that settles it then. Thanks!
> >>>
> >>>> BTW: There is a work in progress on a lockless printk ring buffer.
> >>>> It will make printk() more secure regarding deadlocks. But it might
> >>>> make transparent handling of continuous lines even more tricky.
> >>>>
> >>>> I guess that local buffering, before calling printk(), will be
> >>>> even more important then. Well, it might really force us to create
> >>>> an API for it.
> >>>
> >>> Cool! Can you CC me on that discussion?
> >>
> >> Adding John Oggness into CC.
> >>
> >> John, please CC Brendan Higgins on the patchsets eventually switching
> >> printk() into the lockless buffer. The test framework is going to
> >> do its own buffering to keep the related messages together.
> >>
> >> The lockless ringbuffer might make handling of related (partial)
> >> lines worse or better. It might justify KUnit's extra buffering
> >> or it might allow to get rid of it.
> >
> > Thanks for CC'ing me on the printk ringbuffer thread. It looks like it
> > actually probably won't affect my needs for KUnit logging. The biggest
> > reason I need some sort of buffering system is to be able to compose
> > messages piece meal into a single message that will be printed out to
> > the user as a single message with no messages from other printk
> > callers printed out in the middle of mine.
> 
> printk has this same requirement for its CONT messages. You can read
> about how I propose to implement that here[0], using a separate prb
> ringbuffer for buffered storage until all the pieces are available.
> 
> It is not my goal that multiple subsystems start making use of the prb
> ringbuffer. However, its features can be attractive if you don't want to
> worry about multiple writers/readers or context (including NMI). Before

That sounds like it might be useful down the road, but not to replace
the string_stream.

> writing "yet another ringbuffer" [1] it might be worth the effort to at
> least see if one of the existing implementations can work (or be
> extended to work) for you.

In regards to the conversation here about string_stream/kunit_stream, I
think Petr already answered that question. As I said previously:
> [I]t appears that to get the
> semantics that I need, I would have to put my entire message in a
> single data block and would consequently need to know the size of my
> message a priori, which is problematic. Consequently, it seems as
> though I will probably need to compose my entire message using my own
> buffering system.

I could potentially use my own set of prbs for that buffering; however,
I think this use case is probably closer to seq_buf than your prb.
Really, I just want some kind of string builder, not a message queue.

The place where I think your prb is relevant here is once I have
composed the message and I just want to print it, having a way to print
it without worrying about context is nice, but I think that is a
separate discussion from the main topic here which was just figuring out
the right way to compose that message in the first place.

Cheers

> John Ogness
> 
> [0] https://lkml.kernel.org/r/87imt2bl0k.fsf@linutronix.de
> [1] https://lwn.net/Articles/789603/
> 
> > The prb does look interesting; however, it appears that to get the
> > semantics that I need, I would have to put my entire message in a
> > single data block and would consequently need to know the size of my
> > message a priori, which is problematic. Consequently, it seems as
> > though I will probably need to compose my entire message using my own
> > buffering system.
> >
> >>>> Note that stroring the messages into the printk log is basically
> >>>> safe in any context. It uses temporary per-CPU buffers for
> >>>> recursive messages and in NMI. The only problem is panic() when
> >>>> some CPU gets stuck with the lock taken. This will get solved by
> >>>> the lockless ringbuffer. Also the temporary buffers will not be
> >>>> necessary any longer.
> >>>
> >>> Sure, I think Stephen's concern is all the supporting code that is
> >>> involved. Not printk specifically. It just means a lot more of KUnit
> >>> has to be IRQ safe.
> >>
> >> I see.
> >>
> >> BTW: I wonder if KUnit could reuse the existing seq_buf
> >> implementation for buffering messages.
> >>
> >> I am sorry if it has already been proposed and rejected for some
> >> reason. I might have missed it. Feel free to just point me to
> >> same older mail.
> >
> > Yeah, we discussed it briefly here:
> >
> > https://lkml.org/lkml/2019/5/17/497
> >
> > Looks like I forgot to include my reasoning in the commit text, sorry
> > about that.
> >
> >>>> Much bigger problems are with consoles. There are many of them. It
> >>>> means a lot of code and more locks involved, including scheduler
> >>>> locks. Note that console lock is a semaphore.
> >>>
> >>> That shouldn't affect us though, right? As long as we continue to
> >>> use the printk interface?
> >>
> >> I guess that it should not affect KUnit.
> >>
> >> The only problem might be if the testing framework calls printk()
> >> inside scheduler or console code. And only when the tested code
> >> uses the same locks that will be used by the called printk().
> >
> > Yeah, well printk will not be our only problem in those instances.
> >
> >> To be honest I do not fully understand KUnit design. I am not
> >> completely sure how the tested code is isolated from the running
> >> system. Namely, I do not know if the tested code shares
> >> the same locks with the system running the test.
> >
> > No worries, I don't expect printk to be the hang up in those cases. It
> > sounds like KUnit has a long way to evolve before printk is going to
> > be a limitation.
> >
> > Thanks!

^ permalink raw reply	[flat|nested] 57+ messages in thread

end of thread, back to index

Thread overview: 57+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-07-12  8:17 [PATCH v9 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 01/18] kunit: test: add KUnit test runner core Brendan Higgins
2019-07-15 20:10   ` Stephen Boyd
2019-07-15 21:25     ` Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 02/18] kunit: test: add test resource management API Brendan Higgins
2019-07-15 20:24   ` Stephen Boyd
2019-07-15 20:30     ` Brendan Higgins
2019-07-15 20:51       ` Stephen Boyd
2019-07-12  8:17 ` [PATCH v9 03/18] kunit: test: add string_stream a std::stream like string builder Brendan Higgins
2019-07-15 20:43   ` Stephen Boyd
2019-07-15 21:11     ` Brendan Higgins
2019-07-15 22:04       ` Stephen Boyd
2019-07-15 22:11         ` Brendan Higgins
2019-07-15 22:43           ` Brendan Higgins
2019-07-16 15:33             ` Stephen Boyd
2019-07-16 18:55               ` Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 04/18] kunit: test: add kunit_stream a std::stream like logger Brendan Higgins
2019-07-15 22:15   ` Stephen Boyd
2019-07-16  7:57     ` Brendan Higgins
2019-07-16  8:37       ` Brendan Higgins
2019-07-16 15:30         ` Stephen Boyd
2019-07-16 17:51           ` Brendan Higgins
2019-07-16 17:50         ` Stephen Boyd
2019-07-16 18:52           ` Brendan Higgins
2019-07-18 17:50             ` Stephen Boyd
2019-07-18 19:22               ` Brendan Higgins
2019-07-19  0:08                 ` Brendan Higgins
2019-07-22 18:10                   ` Brendan Higgins
2019-07-22 20:03                   ` Stephen Boyd
2019-07-22 22:30                     ` Brendan Higgins
2019-07-22 23:54                       ` Stephen Boyd
2019-07-23  0:32                         ` Brendan Higgins
2019-07-24  7:31                         ` Petr Mladek
2019-07-25 20:21                           ` Brendan Higgins
2019-07-26  8:31                             ` Petr Mladek
2019-08-01 18:55                               ` Brendan Higgins
2019-08-01 18:59                                 ` Brendan Higgins
2019-08-01 21:14                                   ` Stephen Boyd
2019-08-01 21:43                                     ` Brendan Higgins
2019-08-12 20:41                                       ` Brendan Higgins
2019-08-02  7:37                                 ` John Ogness
2019-08-12 21:12                                   ` Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 05/18] kunit: test: add the concept of expectations Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 06/18] kbuild: enable building KUnit Brendan Higgins
2019-07-15 20:49   ` Stephen Boyd
2019-07-12  8:17 ` [PATCH v9 07/18] kunit: test: add initial tests Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 08/18] objtool: add kunit_try_catch_throw to the noreturn list Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 09/18] kunit: test: add support for test abort Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 10/18] kunit: test: add tests for kunit " Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 11/18] kunit: test: add the concept of assertions Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 12/18] kunit: test: add tests for KUnit managed resources Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 13/18] kunit: tool: add Python wrappers for running KUnit tests Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 14/18] kunit: defconfig: add defconfigs for building " Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 15/18] Documentation: kunit: add documentation for KUnit Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 16/18] MAINTAINERS: add entry for KUnit the unit testing framework Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() Brendan Higgins
2019-07-12  8:17 ` [PATCH v9 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section Brendan Higgins

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