[PATCH v4 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework

[PATCH v4 00/18] kunit: introduce KUnit, the Linux kernel unit testing framework

[Brendan Higgins]

## TLDR

A quick follow up to yesterday's revision. I got some feedback that I
wanted to incorporate before anyone else read the update. For this
reason, I will leave a TLDR of the biggest changes since v2.

Biggest things to look out for (since v2):

- KUnit core now outputs results in TAP14.
- Heavily reworked tools/testing/kunit/kunit.py
  - Changed how parsing works.
  - Added testing.
  - Greg, Logan, you might want to re-review this.
- Added documentation on how to use KUnit on non-UML kernels. You can
  see the docs rendered here[1].

There is still some discussion going on on the [PATCH v2 00/17] thread,
but I wanted to get some of these updates out before they got too stale
(and too difficult for me to keep track of). I hope no one minds.

## 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) 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 under 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/v5.1/v4 branch.

## Changes Since Last Version

As I mentioned above, there are a significant number of updates since
v2:
- Converted KUnit core to print test results in TAP14 format as
  suggested by Greg and Frank.
- Heavily reworked tools/testing/kunit/kunit.py
  - Changed how parsing works.
  - Added testing.
- Added documentation on how to use KUnit on non-UML kernels. You can
  see the docs rendered here[1].
- Added a new set of EXPECTs and ASSERTs for pointer comparison.
- Removed more function indirection as suggested by Logan.
- Added a new patch that adds `kunit_try_catch_throw` to objtool's
  noreturn list.
- Fixed a number of minorish issues pointed out by Shuah, Masahiro, and
  kbuild bot.

Nevertheless, there are only a couple of minor updates since v3:
- Added more context to the changelog on the objtool patch, as per
  Peter's request.
- Moved all KUnit documentation under the Documentation/dev-tools/
  directory as per Jonathan's suggestion.

[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/v5.1/v4

-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 01/18] kunit: test: add KUnit test runner core

[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>
---
 include/kunit/test.h | 162 ++++++++++++++++++++++++++++++
 kunit/Kconfig        |  16 +++
 kunit/Makefile       |   1 +
 kunit/test.c         | 229 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 408 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..e682ea0e1f9a5
--- /dev/null
+++ b/include/kunit/test.h
@@ -0,0 +1,162 @@
+/* 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>
+#include <linux/slab.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_module and will be run after the
+ * module's init function and followed by the module'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[256];
+
+	/* 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_module - 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_module 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_module for KUnit to
+ * run it.
+ */
+struct kunit_module {
+	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_module).
+ *
+ * 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! */
+	spinlock_t lock; /* Gaurds all mutable test state. */
+	bool success; /* Protected by lock. */
+};
+
+void kunit_init_test(struct kunit *test, const char *name);
+
+int kunit_run_tests(struct kunit_module *module);
+
+/**
+ * module_test() - used to register a &struct kunit_module with KUnit.
+ * @module: a statically allocated &struct kunit_module.
+ *
+ * Registers @module with the test framework. See &struct kunit_module for more
+ * information.
+ */
+#define module_test(module) \
+		static int module_kunit_init##module(void) \
+		{ \
+			return kunit_run_tests(&module); \
+		} \
+		late_initcall(module_kunit_init##module)
+
+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 module 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.
+ *
+ * See kunit_info().
+ */
+#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.
+ *
+ * See kunit_info().
+ */
+#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..64480092b2c24
--- /dev/null
+++ b/kunit/Kconfig
@@ -0,0 +1,16 @@
+#
+# 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. For more information, please see
+	  Documentation/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..86f65ba2bcf92
--- /dev/null
+++ b/kunit/test.c
@@ -0,0 +1,229 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Base unit test (KUnit) API.
+ *
+ * Copyright (C) 2019, Google LLC.
+ * Author: Brendan Higgins <brendanhiggins@google.com>
+ */
+
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <kunit/test.h>
+
+static bool kunit_get_success(struct kunit *test)
+{
+	unsigned long flags;
+	bool success;
+
+	spin_lock_irqsave(&test->lock, flags);
+	success = test->success;
+	spin_unlock_irqrestore(&test->lock, flags);
+
+	return success;
+}
+
+static void kunit_set_success(struct kunit *test, bool success)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&test->lock, flags);
+	test->success = success;
+	spin_unlock_irqrestore(&test->lock, flags);
+}
+
+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 bool kunit_has_printed_tap_version;
+
+static void kunit_print_tap_version(void)
+{
+	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_module *module)
+{
+	kunit_print_tap_version();
+	kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", module->name);
+	kunit_printk_emit(LOGLEVEL_INFO,
+			  "\t1..%zd\n",
+			  kunit_test_cases_len(module->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_module_has_succeeded(struct kunit_module *module)
+{
+	struct kunit_case *test_case;
+	bool success = true;
+
+	for (test_case = module->test_cases; test_case->run_case; test_case++)
+		if (!test_case->success)
+			success = false;
+
+	return success;
+}
+
+size_t kunit_module_counter = 1;
+
+static void kunit_print_subtest_end(struct kunit_module *module)
+{
+	kunit_print_ok_not_ok(false,
+			      kunit_module_has_succeeded(module),
+			      kunit_module_counter++,
+			      module->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)
+{
+	spin_lock_init(&test->lock);
+	test->name = name;
+}
+
+/*
+ * Initializes and runs test case. Does not clean up or do post validations.
+ */
+static void kunit_run_case_internal(struct kunit *test,
+				    struct kunit_module *module,
+				    struct kunit_case *test_case)
+{
+	int ret;
+
+	if (module->init) {
+		ret = module->init(test);
+		if (ret) {
+			kunit_err(test, "failed to initialize: %d\n", ret);
+			kunit_set_success(test, false);
+			return;
+		}
+	}
+
+	test_case->run_case(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_module *module,
+				   struct kunit_case *test_case)
+{
+	if (module->exit)
+		module->exit(test);
+}
+
+/*
+ * Performs all logic to run a test case.
+ */
+static void kunit_run_case(struct kunit_module *module,
+			   struct kunit_case *test_case)
+{
+	struct kunit test;
+
+	kunit_init_test(&test, test_case->name);
+	kunit_set_success(&test, true);
+
+	kunit_run_case_internal(&test, module, test_case);
+	kunit_run_case_cleanup(&test, module, test_case);
+
+	test_case->success = kunit_get_success(&test);
+}
+
+int kunit_run_tests(struct kunit_module *module)
+{
+	struct kunit_case *test_case;
+	size_t test_case_count = 1;
+
+	kunit_print_subtest_start(module);
+
+	for (test_case = module->test_cases; test_case->run_case; test_case++) {
+		kunit_run_case(module, test_case);
+		kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
+	}
+
+	kunit_print_subtest_end(module);
+
+	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);
+}
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 02/18] kunit: test: add test resource management API

[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 | 109 +++++++++++++++++++++++++++++++++++++++++++
 kunit/test.c         |  95 +++++++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index e682ea0e1f9a5..5e86d88cd5305 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -12,6 +12,69 @@
 #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;
+ *		else
+ *			return NULL;
+ *	}
+ */
+struct kunit_resource {
+	void *allocation;
+	kunit_resource_free_t free;
+
+	/* private: internal use only. */
+	struct list_head node;
+};
+
 struct kunit;
 
 /**
@@ -104,6 +167,7 @@ struct kunit {
 	const char *name; /* Read only after initialization! */
 	spinlock_t lock; /* Gaurds all mutable test state. */
 	bool success; /* Protected by lock. */
+	struct list_head resources; /* Protected by lock. */
 };
 
 void kunit_init_test(struct kunit *test, const char *name);
@@ -124,6 +188,51 @@ int kunit_run_tests(struct kunit_module *module);
 		} \
 		late_initcall(module_kunit_init##module)
 
+/**
+ * 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 86f65ba2bcf92..a15e6f8c41582 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -141,6 +141,7 @@ static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
 void kunit_init_test(struct kunit *test, const char *name)
 {
 	spin_lock_init(&test->lock);
+	INIT_LIST_HEAD(&test->resources);
 	test->name = name;
 }
 
@@ -165,6 +166,11 @@ static void kunit_run_case_internal(struct kunit *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!
@@ -175,6 +181,8 @@ static void kunit_run_case_cleanup(struct kunit *test,
 {
 	if (module->exit)
 		module->exit(test);
+
+	kunit_case_internal_cleanup(test);
 }
 
 /*
@@ -211,6 +219,93 @@ int kunit_run_tests(struct kunit_module *module)
 	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;
+	unsigned long flags;
+	int ret;
+
+	res = kzalloc(sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return NULL;
+
+	ret = init(res, context);
+	if (ret)
+		return NULL;
+
+	res->free = free;
+	spin_lock_irqsave(&test->lock, flags);
+	list_add_tail(&res->node, &test->resources);
+	spin_unlock_irqrestore(&test->lock, flags);
+
+	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;
+	else
+		return NULL;
+}
+
+void kunit_cleanup(struct kunit *test)
+{
+	struct kunit_resource *resource, *resource_safe;
+	unsigned long flags;
+
+	spin_lock_irqsave(&test->lock, flags);
+	list_for_each_entry_safe(resource,
+				 resource_safe,
+				 &test->resources,
+				 node) {
+		kunit_free_resource(test, resource);
+	}
+	spin_unlock_irqrestore(&test->lock, flags);
+}
+
 void kunit_printk(const char *level,
 		  const struct kunit *test,
 		  const char *fmt, ...)
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 03/18] kunit: test: add string_stream a std::stream like string builder

[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 |  51 ++++++++++++
 kunit/Makefile                |   3 +-
 kunit/string-stream.c         | 143 ++++++++++++++++++++++++++++++++++
 3 files changed, 196 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..567a4629406da
--- /dev/null
+++ b/include/kunit/string-stream.h
@@ -0,0 +1,51 @@
+/* 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 kref refcount;
+};
+
+struct string_stream *new_string_stream(void);
+
+void destroy_string_stream(struct string_stream *stream);
+
+void string_stream_get(struct string_stream *stream);
+
+int string_stream_put(struct string_stream *stream);
+
+int string_stream_add(struct string_stream *this, const char *fmt, ...);
+
+int string_stream_vadd(struct string_stream *this,
+		       const char *fmt,
+		       va_list args);
+
+char *string_stream_get_string(struct string_stream *this);
+
+void string_stream_clear(struct string_stream *this);
+
+bool string_stream_is_empty(struct string_stream *this);
+
+#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..d4e4252dc10b8
--- /dev/null
+++ b/kunit/string-stream.c
@@ -0,0 +1,143 @@
+// 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>
+
+int string_stream_vadd(struct string_stream *this,
+		       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(&this->lock, flags);
+	this->length += len;
+	list_add_tail(&frag_container->node, &this->fragments);
+	spin_unlock_irqrestore(&this->lock, flags);
+	return 0;
+}
+
+int string_stream_add(struct string_stream *this, const char *fmt, ...)
+{
+	va_list args;
+	int result;
+
+	va_start(args, fmt);
+	result = string_stream_vadd(this, fmt, args);
+	va_end(args);
+	return result;
+}
+
+void string_stream_clear(struct string_stream *this)
+{
+	struct string_stream_fragment *frag_container, *frag_container_safe;
+	unsigned long flags;
+
+	spin_lock_irqsave(&this->lock, flags);
+	list_for_each_entry_safe(frag_container,
+				 frag_container_safe,
+				 &this->fragments,
+				 node) {
+		list_del(&frag_container->node);
+		kfree(frag_container->fragment);
+		kfree(frag_container);
+	}
+	this->length = 0;
+	spin_unlock_irqrestore(&this->lock, flags);
+}
+
+char *string_stream_get_string(struct string_stream *this)
+{
+	struct string_stream_fragment *frag_container;
+	size_t buf_len = this->length + 1; /* +1 for null byte. */
+	char *buf;
+	unsigned long flags;
+
+	buf = kzalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		return NULL;
+
+	spin_lock_irqsave(&this->lock, flags);
+	list_for_each_entry(frag_container, &this->fragments, node)
+		strlcat(buf, frag_container->fragment, buf_len);
+	spin_unlock_irqrestore(&this->lock, flags);
+
+	return buf;
+}
+
+bool string_stream_is_empty(struct string_stream *this)
+{
+	bool is_empty;
+	unsigned long flags;
+
+	spin_lock_irqsave(&this->lock, flags);
+	is_empty = list_empty(&this->fragments);
+	spin_unlock_irqrestore(&this->lock, flags);
+
+	return is_empty;
+}
+
+void destroy_string_stream(struct string_stream *stream)
+{
+	string_stream_clear(stream);
+	kfree(stream);
+}
+
+static void string_stream_destroy(struct kref *kref)
+{
+	struct string_stream *stream = container_of(kref,
+						    struct string_stream,
+						    refcount);
+	destroy_string_stream(stream);
+}
+
+struct string_stream *new_string_stream(void)
+{
+	struct string_stream *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
+
+	if (!stream)
+		return NULL;
+
+	INIT_LIST_HEAD(&stream->fragments);
+	spin_lock_init(&stream->lock);
+	kref_init(&stream->refcount);
+	return stream;
+}
+
+void string_stream_get(struct string_stream *stream)
+{
+	kref_get(&stream->refcount);
+}
+
+int string_stream_put(struct string_stream *stream)
+{
+	return kref_put(&stream->refcount, &string_stream_destroy);
+}
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 04/18] kunit: test: add kunit_stream a std::stream like logger

[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 |  85 ++++++++++++++++++++
 include/kunit/test.h         |   3 +
 kunit/Makefile               |   3 +-
 kunit/kunit-stream.c         | 152 +++++++++++++++++++++++++++++++++++
 kunit/test.c                 |   7 ++
 5 files changed, 249 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..d457a54fe0100
--- /dev/null
+++ b/include/kunit/kunit-stream.h
@@ -0,0 +1,85 @@
+/* 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;
+	spinlock_t lock; /* Guards level. */
+	const char *level;
+	struct string_stream *internal_stream;
+};
+
+/**
+ * kunit_new_stream() - constructs a new &struct kunit_stream.
+ * @test: The test context object.
+ *
+ * Constructs a new test managed &struct kunit_stream.
+ */
+struct kunit_stream *kunit_new_stream(struct kunit *test);
+
+/**
+ * kunit_stream_set_level(): sets the level that string should be printed at.
+ * @this: the stream being operated on.
+ * @level: the print level the stream is set to output to.
+ *
+ * Sets the print level at which the stream outputs.
+ */
+void kunit_stream_set_level(struct kunit_stream *this, const char *level);
+
+/**
+ * kunit_stream_add(): adds the formatted input to the internal buffer.
+ * @this: 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 *this,
+				     const char *fmt, ...);
+
+/**
+ * kunit_stream_append(): appends the contents of @other to @this.
+ * @this: the stream to which @other is appended.
+ * @other: the stream whose contents are appended to @this.
+ *
+ * Appends the contents of @other to @this.
+ */
+void kunit_stream_append(struct kunit_stream *this, struct kunit_stream *other);
+
+/**
+ * kunit_stream_commit(): prints out the internal buffer to the user.
+ * @this: the stream being operated on.
+ *
+ * Outputs the contents of the internal buffer as a kunit_printk formatted
+ * output.
+ */
+void kunit_stream_commit(struct kunit_stream *this);
+
+/**
+ * kunit_stream_clear(): clears the internal buffer.
+ * @this: the stream being operated on.
+ *
+ * Clears the contents of the internal buffer.
+ */
+void kunit_stream_clear(struct kunit_stream *this);
+
+#endif /* _KUNIT_KUNIT_STREAM_H */
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 5e86d88cd5305..4bc839884a83c 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;
 
@@ -172,6 +173,8 @@ 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_module *module);
 
 /**
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..1884f1b550888
--- /dev/null
+++ b/kunit/kunit-stream.c
@@ -0,0 +1,152 @@
+// 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>
+
+static const char *kunit_stream_get_level(struct kunit_stream *this)
+{
+	unsigned long flags;
+	const char *level;
+
+	spin_lock_irqsave(&this->lock, flags);
+	level = this->level;
+	spin_unlock_irqrestore(&this->lock, flags);
+
+	return level;
+}
+
+void kunit_stream_set_level(struct kunit_stream *this, const char *level)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&this->lock, flags);
+	this->level = level;
+	spin_unlock_irqrestore(&this->lock, flags);
+}
+
+void kunit_stream_add(struct kunit_stream *this, const char *fmt, ...)
+{
+	va_list args;
+	struct string_stream *stream = this->internal_stream;
+
+	va_start(args, fmt);
+
+	if (string_stream_vadd(stream, fmt, args) < 0)
+		kunit_err(this->test, "Failed to allocate fragment: %s\n", fmt);
+
+	va_end(args);
+}
+
+void kunit_stream_append(struct kunit_stream *this,
+				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(this->test,
+			  "Failed to get string from second argument for appending.\n");
+		return;
+	}
+
+	kunit_stream_add(this, other_content);
+}
+
+void kunit_stream_clear(struct kunit_stream *this)
+{
+	string_stream_clear(this->internal_stream);
+}
+
+void kunit_stream_commit(struct kunit_stream *this)
+{
+	struct string_stream *stream = this->internal_stream;
+	struct string_stream_fragment *fragment;
+	const char *level;
+	char *buf;
+
+	level = kunit_stream_get_level(this);
+	if (!level) {
+		kunit_err(this->test,
+			  "Stream was committed without a specified log level.\n");
+		level = KERN_ERR;
+		kunit_stream_set_level(this, level);
+	}
+
+	buf = string_stream_get_string(stream);
+	if (!buf) {
+		kunit_err(this->test,
+			 "Could not allocate buffer, dumping stream:\n");
+		list_for_each_entry(fragment, &stream->fragments, node) {
+			kunit_err(this->test, fragment->fragment);
+		}
+		kunit_err(this->test, "\n");
+		goto cleanup;
+	}
+
+	kunit_printk(level, this->test, buf);
+	kfree(buf);
+
+cleanup:
+	kunit_stream_clear(this);
+}
+
+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;
+	spin_lock_init(&stream->lock);
+	stream->internal_stream = new_string_stream();
+
+	if (!stream->internal_stream) {
+		kfree(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);
+	}
+
+	destroy_string_stream(stream->internal_stream);
+	kfree(stream);
+}
+
+struct kunit_stream *kunit_new_stream(struct kunit *test)
+{
+	struct kunit_resource *res;
+
+	res = kunit_alloc_resource(test,
+				   kunit_stream_init,
+				   kunit_stream_free,
+				   test);
+
+	if (res)
+		return res->allocation;
+	else
+		return NULL;
+}
diff --git a/kunit/test.c b/kunit/test.c
index a15e6f8c41582..0bb6f53a7f87e 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -138,6 +138,13 @@ 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_success(test, false);
+	kunit_stream_set_level(stream, KERN_ERR);
+	kunit_stream_commit(stream);
+}
+
 void kunit_init_test(struct kunit *test, const char *name)
 {
 	spin_lock_init(&test->lock);
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 05/18] kunit: test: add the concept of expectations

[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 | 518 +++++++++++++++++++++++++++++++++++++++++++
 kunit/test.c         |  66 ++++++
 2 files changed, 584 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 4bc839884a83c..86187ba069a5d 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -271,4 +271,522 @@ void __printf(3, 4) kunit_printk(const char *level,
 #define kunit_err(test, fmt, ...) \
 		kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)
 
+static inline struct kunit_stream *kunit_expect_start(struct kunit *test,
+						      const char *file,
+						      const char *line)
+{
+	struct kunit_stream *stream = kunit_new_stream(test);
+
+	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.")
+
+#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_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_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_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_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.");       \
+	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.");       \
+		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 0bb6f53a7f87e..e0727afb5d8a9 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -329,3 +329,69 @@ 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);
+}
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 06/18] kbuild: enable building KUnit

[Brendan Higgins]

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>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
---
 Kconfig  | 2 ++
 Makefile | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

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 26c92f892d24b..2ea87a8fe770d 100644
--- a/Makefile
+++ b/Makefile
@@ -969,7 +969,7 @@ endif
 PHONY += prepare0
 
 ifeq ($(KBUILD_EXTMOD),)
-core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
+core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ kunit/
 
 vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
 		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 07/18] kunit: test: add initial tests

[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              | 25 ++++++++++-
 kunit/Makefile             |  4 ++
 kunit/example-test.c       | 88 ++++++++++++++++++++++++++++++++++++++
 kunit/string-stream-test.c | 60 ++++++++++++++++++++++++++
 4 files changed, 175 insertions(+), 2 deletions(-)
 create mode 100644 kunit/example-test.c
 create mode 100644 kunit/string-stream-test.c

diff --git a/kunit/Kconfig b/kunit/Kconfig
index 64480092b2c24..2052536cf9d3c 100644
--- a/kunit/Kconfig
+++ b/kunit/Kconfig
@@ -10,7 +10,28 @@ config KUNIT
 	  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. For more information, please see
-	  Documentation/kunit/
+	  special hardware when using UML. Can also be used on most other
+	  architectures. For more information, please see Documentation/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..3947dd7c8f922
--- /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_module 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 module
+ * 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 module.
+	 */
+	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 module would behave as follows:
+ *
+ * module.init(test);
+ * module.test_case[0](test);
+ * module.exit(test);
+ * module.init(test);
+ * module.test_case[1](test);
+ * module.exit(test);
+ * ...;
+ */
+static struct kunit_module example_test_module = {
+	.name = "example",
+	.init = example_test_init,
+	.test_cases = example_test_cases,
+};
+
+/*
+ * This registers the above test module telling KUnit that this is a suite of
+ * tests that need to be run.
+ */
+module_test(example_test_module);
diff --git a/kunit/string-stream-test.c b/kunit/string-stream-test.c
new file mode 100644
index 0000000000000..9cbd99236d15e
--- /dev/null
+++ b/kunit/string-stream-test.c
@@ -0,0 +1,60 @@
+// 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_get_string(struct kunit *test)
+{
+	struct string_stream *stream = new_string_stream();
+	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);
+	destroy_string_stream(stream);
+}
+
+static void string_stream_test_add_and_clear(struct kunit *test)
+{
+	struct string_stream *stream = new_string_stream();
+	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, 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));
+	destroy_string_stream(stream);
+}
+
+static struct kunit_case string_stream_test_cases[] = {
+	KUNIT_CASE(string_stream_test_get_string),
+	KUNIT_CASE(string_stream_test_add_and_clear),
+	{}
+};
+
+static struct kunit_module string_stream_test_module = {
+	.name = "string-stream-test",
+	.test_cases = string_stream_test_cases
+};
+module_test(string_stream_test_module);
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 08/18] objtool: add kunit_try_catch_throw to the noreturn list

[Brendan Higgins]

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>
Link: https://www.spinics.net/lists/linux-kbuild/msg21708.html
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 479196aeb4096..be431d4557fe5 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -166,6 +166,7 @@ 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)
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 09/18] kunit: test: add support for test abort

[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      |  14 ++++
 include/kunit/try-catch.h |  69 +++++++++++++++++++
 kunit/Makefile            |   3 +-
 kunit/test.c              | 136 ++++++++++++++++++++++++++++++++++++--
 kunit/try-catch.c         |  95 ++++++++++++++++++++++++++
 5 files changed, 309 insertions(+), 8 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 86187ba069a5d..aff55b5610e7d 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -12,6 +12,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <kunit/kunit-stream.h>
+#include <kunit/try-catch.h>
 
 struct kunit_resource;
 
@@ -166,15 +167,28 @@ struct kunit {
 
 	/* private: internal use only. */
 	const char *name; /* Read only after initialization! */
+	struct kunit_try_catch try_catch;
 	spinlock_t lock; /* Gaurds all mutable test state. */
 	bool success; /* Protected by lock. */
+	bool death_test; /* Protected by lock. */
 	struct list_head resources; /* Protected by lock. */
 };
 
+static inline void kunit_set_death_test(struct kunit *test, bool death_test)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&test->lock, flags);
+	test->death_test = death_test;
+	spin_unlock_irqrestore(&test->lock, flags);
+}
+
 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_module *module);
 
 /**
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 e0727afb5d8a9..34cecc5c805e8 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -6,9 +6,9 @@
  * Author: Brendan Higgins <brendanhiggins@google.com>
  */
 
-#include <linux/sched.h>
 #include <linux/sched/debug.h>
 #include <kunit/test.h>
+#include <kunit/try-catch.h>
 
 static bool kunit_get_success(struct kunit *test)
 {
@@ -31,6 +31,18 @@ static void kunit_set_success(struct kunit *test, bool success)
 	spin_unlock_irqrestore(&test->lock, flags);
 }
 
+static bool kunit_get_death_test(struct kunit *test)
+{
+	unsigned long flags;
+	bool death_test;
+
+	spin_lock_irqsave(&test->lock, flags);
+	death_test = test->death_test;
+	spin_unlock_irqrestore(&test->lock, flags);
+
+	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);
@@ -145,6 +157,21 @@ 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)
 {
 	spin_lock_init(&test->lock);
@@ -193,18 +220,113 @@ static void kunit_run_case_cleanup(struct kunit *test,
 }
 
 /*
- * Performs all logic to run a test case.
+ * Handles an unexpected crash in a test case.
+ */
+static void kunit_handle_test_crash(struct kunit *test,
+				   struct kunit_module *module,
+				   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_module *module;
+	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_module *module = ctx->module;
+	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, module, test_case);
+	/* This line may never be reached. */
+	kunit_run_case_cleanup(test, module, test_case);
+}
+
+static void kunit_catch_run_case(void *data)
+{
+	struct kunit_try_catch_context *ctx = data;
+	struct kunit *test = ctx->test;
+	struct kunit_module *module = ctx->module;
+	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_success(test, false);
+		/*
+		 * 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, module, test_case);
+	} 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, module, test_case);
+		kunit_set_success(test, false);
+	}
+}
+
+/*
+ * 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(struct kunit_module *module,
-			   struct kunit_case *test_case)
+static void kunit_run_case_catch_errors(struct kunit_module *module,
+					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_set_success(&test, true);
+	kunit_set_death_test(&test, false);
 
-	kunit_run_case_internal(&test, module, test_case);
-	kunit_run_case_cleanup(&test, module, test_case);
+	kunit_try_catch_init(try_catch,
+			     &test,
+			     kunit_try_run_case,
+			     kunit_catch_run_case);
+	context.test = &test;
+	context.module = module;
+	context.test_case = test_case;
+	kunit_try_catch_run(try_catch, &context);
 
 	test_case->success = kunit_get_success(&test);
 }
@@ -217,7 +339,7 @@ int kunit_run_tests(struct kunit_module *module)
 	kunit_print_subtest_start(module);
 
 	for (test_case = module->test_cases; test_case->run_case; test_case++) {
-		kunit_run_case(module, test_case);
+		kunit_run_case_catch_errors(module, 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;
+}
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 10/18] kunit: test: add tests for kunit test abort

[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..577df5a8d309e
--- /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_module kunit_try_catch_test_module = {
+	.name = "kunit-try-catch-test",
+	.init = kunit_try_catch_test_init,
+	.test_cases = kunit_try_catch_test_cases,
+};
+module_test(kunit_try_catch_test_module);
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 11/18] kunit: test: add the concept of assertions

[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       | 498 ++++++++++++++++++++++++++++++++++++-
 kunit/string-stream-test.c |  12 +-
 kunit/test-test.c          |   2 +
 kunit/test.c               |  66 +++++
 4 files changed, 569 insertions(+), 9 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index aff55b5610e7d..48e76c5c204b5 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -85,9 +85,10 @@ 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_module and will be run after the
- * module's init function and followed by the module'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_module and will be run after the module's init function and
+ * followed by the module'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
@@ -803,4 +804,495 @@ static inline void kunit_expect_ptr_binary(struct kunit *test,
 	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 = kunit_new_stream(test);
+
+	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_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_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_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_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 9cbd99236d15e..f760c6ddb7919 100644
--- a/kunit/string-stream-test.c
+++ b/kunit/string-stream-test.c
@@ -19,7 +19,7 @@ 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);
 	destroy_string_stream(stream);
 }
@@ -34,16 +34,16 @@ 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, 10);
-	KUNIT_EXPECT_FALSE(test, string_stream_is_empty(stream));
+	KUNIT_ASSERT_STREQ(test, output, "AAAAAAAAAA");
+	KUNIT_ASSERT_EQ(test, stream->length, 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));
 	destroy_string_stream(stream);
 }
 
diff --git a/kunit/test-test.c b/kunit/test-test.c
index 577df5a8d309e..7afc9bb52f7be 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 34cecc5c805e8..94d6886043d8d 100644
--- a/kunit/test.c
+++ b/kunit/test.c
@@ -517,3 +517,69 @@ 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);
+}
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 12/18] kunit: test: add tests for KUnit managed resources

[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 | 123 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)

diff --git a/kunit/test-test.c b/kunit/test-test.c
index 7afc9bb52f7be..ee926f798b266 100644
--- a/kunit/test-test.c
+++ b/kunit/test-test.c
@@ -101,3 +101,126 @@ static struct kunit_module kunit_try_catch_test_module = {
 	.test_cases = kunit_try_catch_test_cases,
 };
 module_test(kunit_try_catch_test_module);
+
+/*
+ * 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;
+};
+
+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, 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_EQ(test, false, 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 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),
+	{},
+};
+
+static struct kunit_module kunit_resource_test_module = {
+	.name = "kunit-resource-test",
+	.init = kunit_resource_test_init,
+	.exit = kunit_resource_test_exit,
+	.test_cases = kunit_resource_test_cases,
+};
+module_test(kunit_resource_test_module);
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 13/18] kunit: tool: add Python wrappers for running KUnit tests

[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.

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..85ed1c32a6c48
--- /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..31c634e4202b1
--- /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','modules','log'])
+
+class TestModule(object):
+	def __init__(self):
+		self.status = None
+		self.name = None
+		self.cases = []
+
+	def __str__(self):
+		return 'TestModule(' + 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]+$')
+kunit_end_re = re.compile('List of all partitions:')
+
+def isolate_kunit_output(kernel_output):
+	started = False
+	for line in kernel_output:
+		if kunit_start_re.match(line):
+			started = True
+			yield line
+		elif kunit_end_re.match(line):
+			break
+		elif started:
+			yield line
+
+def raw_output(kernel_output):
+	for line in kernel_output:
+		print(line)
+
+DIVIDER = '=' * 60
+
+RESET = '\033[0;0m'
+
+def red(text):
+	return '\033[1;31m' + text + RESET
+
+def yellow(text):
+	return '\033[1;33m' + text + RESET
+
+def green(text):
+	return '\033[1;32m' + text + RESET
+
+def print_with_timestamp(message):
+	print('[%s] %s' % (datetime.now().strftime('%H:%M:%S'), message))
+
+def format_module_divider(message):
+	return '======== ' + message + ' ========'
+
+def print_module_divider(message):
+	print_with_timestamp(DIVIDER)
+	print_with_timestamp(format_module_divider(message))
+
+def print_log(log):
+	for m in log:
+		print_with_timestamp(m)
+
+TAP_ENTRIES = re.compile(r'^(TAP|\t?ok|\t?not ok|\t?[0-9]+\.\.[0-9]+|\t?#).*$')
+
+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_module(lines: List[str], test_module: TestModule) -> 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_module.status = TestStatus.SUCCESS
+		else:
+			test_module.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_module: TestModule) -> TestStatus:
+	max_test_case_status = bubble_up_errors(lambda x: x.status, test_module.cases)
+	return max_status(max_test_case_status, test_module.status)
+
+def parse_test_module(lines: List[str]) -> TestModule:
+	if not lines:
+		return None
+	consume_non_diagnositic(lines)
+	test_module = TestModule()
+	test_module.status = TestStatus.SUCCESS
+	name = parse_subtest_header(lines)
+	if not name:
+		return None
+	test_module.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_module.cases.append(test_case)
+		test_case = parse_test_case(lines)
+	if parse_ok_not_ok_test_module(lines, test_module):
+		test_module.status = bubble_up_test_case_errors(test_module)
+		return test_module
+	else:
+		print('failed to parse end of module' + 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_module_errors(test_module_list: List[TestModule]) -> TestStatus:
+	return bubble_up_errors(lambda x: x.status, test_module_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_modules = []
+	test_module = parse_test_module(lines)
+	while test_module:
+		test_modules.append(test_module)
+		test_module = parse_test_module(lines)
+	return TestResult(bubble_up_module_errors(test_modules), test_modules, 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_module in test_result.modules:
+		if test_module.status == TestStatus.SUCCESS:
+			print_module_divider(green('[PASSED] ') + test_module.name)
+		elif test_module.status == TestStatus.TEST_CRASHED:
+			print_module_divider(red('[CRASHED] ' + test_module.name))
+		else:
+			print_module_divider(red('[FAILED] ') + test_module.name)
+		for test_case in test_module.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..50c3ed3108a6e
--- /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.modules))
+		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..8b5aa2f0cb498
--- /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_module
+	# 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..9ea558882d524
--- /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_module
+	# 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>] ? module_kunit_initexample_test_module+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..73ed8730b76b2
--- /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_module
+	# 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..6e92bc7e28041
--- /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_module
+	# 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
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 14/18] kunit: defconfig: add defconfigs for building KUnit tests

[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 85ed1c32a6c48..956326f87101f 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):
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 15/18] Documentation: kunit: add documentation for KUnit

[Brendan Higgins]

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>
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..1f8d1f247202c
--- /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
+
+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_module misc_example_test_module = {
+		.name = "misc-example",
+		.test_cases = misc_example_test_cases,
+	};
+	module_test(misc_example_test_module);
+
+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..4647219f99b4c
--- /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.
+
+Modules / 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 module*; 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_module example_test_module = {
+		.name = "example",
+		.init = example_test_init,
+		.exit = example_test_exit,
+		.test_cases = example_test_cases,
+	};
+	module_test(example_test_module);
+
+In the above example the test suite, ``example_test_module``, 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.
+``module_test(example_test_module)`` 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.
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 16/18] MAINTAINERS: add entry for KUnit the unit testing framework

[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 2c2fce72e694f..8a91887c8d541 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8448,6 +8448,17 @@ 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/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
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[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>
---
 kernel/Makefile      |   2 +
 kernel/sysctl-test.c | 293 +++++++++++++++++++++++++++++++++++++++++++
 lib/Kconfig.debug    |   6 +
 3 files changed, 301 insertions(+)
 create mode 100644 kernel/sysctl-test.c

diff --git a/kernel/Makefile b/kernel/Makefile
index 6c57e78817dad..c81a8976b6a4b 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -112,6 +112,8 @@ 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..fe0f2bae66085
--- /dev/null
+++ b/kernel/sysctl-test.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test of proc sysctl.
+ */
+
+#include <kunit/test.h>
+#include <linux/printk.h>
+#include <linux/sysctl.h>
+#include <linux/uaccess.h>
+
+static int i_zero;
+static int i_one_hundred = 100;
+
+struct test_sysctl_data {
+	int int_0001;
+	int int_0002;
+	int int_0003[4];
+
+	unsigned int uint_0001;
+
+	char string_0001[65];
+};
+
+static struct test_sysctl_data test_data = {
+	.int_0001 = 60,
+	.int_0002 = 1,
+
+	.int_0003[0] = 0,
+	.int_0003[1] = 1,
+	.int_0003[2] = 2,
+	.int_0003[3] = 3,
+
+	.uint_0001 = 314,
+
+	.string_0001 = "(none)",
+};
+
+static void sysctl_test_dointvec_null_tbl_data(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= NULL,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void  *buffer = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	size_t len;
+	loff_t pos;
+
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 0, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+}
+
+static void sysctl_test_dointvec_table_maxlen_unset(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.maxlen		= 0,
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void  *buffer = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	size_t len;
+	loff_t pos;
+
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 0, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+	len = 1234;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+}
+
+static void sysctl_test_dointvec_table_len_is_zero(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void  *buffer = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	size_t len;
+	loff_t pos;
+
+	len = 0;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 0, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+}
+
+static void sysctl_test_dointvec_table_read_but_position_set(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	void  *buffer = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	size_t len;
+	loff_t pos;
+
+	len = 1234;
+	pos = 1;
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 0, buffer, &len, &pos));
+	KUNIT_EXPECT_EQ(test, 0, len);
+}
+
+static void sysctl_test_dointvec_happy_single_positive(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.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;
+
+	table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
+	KUNIT_EXPECT_EQ(test, 9, *(int *)table.data);
+}
+
+static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.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;
+
+	table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
+	KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
+}
+
+static void sysctl_test_dointvec_single_less_int_min(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	char input[32];
+	size_t len = sizeof(input) - 1;
+	loff_t pos = 0;
+	unsigned long abs_of_less_than_min = (unsigned long)INT_MAX
+					     - (INT_MAX + INT_MIN) + 1;
+
+	KUNIT_EXPECT_LT(test,
+			snprintf(input, sizeof(input), "-%lu",
+				 abs_of_less_than_min),
+			sizeof(input));
+
+	table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	KUNIT_EXPECT_EQ(test, -EINVAL,
+			proc_dointvec(&table, 1, input, &len, &pos));
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
+	KUNIT_EXPECT_EQ(test, 0, *(int *)table.data);
+}
+
+static void sysctl_test_dointvec_single_greater_int_max(struct kunit *test)
+{
+	struct ctl_table table = {
+		.procname = "foo",
+		.data		= &test_data.int_0001,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec,
+		.extra1		= &i_zero,
+		.extra2         = &i_one_hundred,
+	};
+	char input[32];
+	size_t len = sizeof(input) - 1;
+	loff_t pos = 0;
+	unsigned long greater_than_max = (unsigned long)INT_MAX + 1;
+
+	KUNIT_EXPECT_GT(test, greater_than_max, INT_MAX);
+	KUNIT_EXPECT_LT(test, snprintf(input, sizeof(input), "%lu",
+				       greater_than_max),
+			sizeof(input));
+	table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
+	KUNIT_EXPECT_EQ(test, -EINVAL,
+			proc_dointvec(&table, 1, input, &len, &pos));
+	KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
+	KUNIT_EXPECT_EQ(test, 0, *(int *)table.data);
+}
+
+static int sysctl_test_init(struct kunit *test)
+{
+	return 0;
+}
+
+/*
+ * This is run once after each test case, see the comment on example_test_module
+ * for more information.
+ */
+static void sysctl_test_exit(struct kunit *test)
+{
+}
+
+/*
+ * Here we make a list of all the test cases we want to add to the test module
+ * below.
+ */
+static struct kunit_case sysctl_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 module.
+	 */
+	KUNIT_CASE(sysctl_test_dointvec_null_tbl_data),
+	KUNIT_CASE(sysctl_test_dointvec_table_maxlen_unset),
+	KUNIT_CASE(sysctl_test_dointvec_table_len_is_zero),
+	KUNIT_CASE(sysctl_test_dointvec_table_read_but_position_set),
+	KUNIT_CASE(sysctl_test_dointvec_happy_single_positive),
+	KUNIT_CASE(sysctl_test_dointvec_happy_single_negative),
+	KUNIT_CASE(sysctl_test_dointvec_single_less_int_min),
+	KUNIT_CASE(sysctl_test_dointvec_single_greater_int_max),
+	{},
+};
+
+/*
+ * This defines a suite or grouping of tests.
+ *
+ * Test cases are defined as belonging to the suite by adding them to
+ * `test_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 module would behave as follows:
+ *
+ * module.init(test);
+ * module.test_case[0](test);
+ * module.exit(test);
+ * module.init(test);
+ * module.test_case[1](test);
+ * module.exit(test);
+ * ...;
+ */
+static struct kunit_module sysctl_test_module = {
+	.name = "sysctl_test",
+	.init = sysctl_test_init,
+	.exit = sysctl_test_exit,
+	.test_cases = sysctl_test_cases,
+};
+
+/*
+ * This registers the above test module telling KUnit that this is a suite of
+ * tests that need to be run.
+ */
+module_test(sysctl_test_module);
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index d5a4a4036d2f8..772af4ec70111 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1908,6 +1908,12 @@ config TEST_SYSCTL
 
 	  If unsure, say N.
 
+config SYSCTL_KUNIT_TEST
+	bool "KUnit test for sysctl"
+	depends on KUNIT
+	help
+	  Enables KUnit sysctl test.
+
 config TEST_UDELAY
 	tristate "udelay test driver"
 	help
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH v4 18/18] MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section

[Brendan Higgins]

Add entry for the new proc sysctl KUnit test to the PROC SYSCTL section.

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

diff --git a/MAINTAINERS b/MAINTAINERS
index 8a91887c8d541..2e539647589fd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12526,6 +12526,7 @@ 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
-- 
2.21.0.1020.gf2820cf01a-goog

Re: [PATCH v4 16/18] MAINTAINERS: add entry for KUnit the unit testing framework

[Brendan Higgins]

On Tue, May 14, 2019 at 03:17:09PM -0700, Brendan Higgins wrote:
> 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 2c2fce72e694f..8a91887c8d541 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8448,6 +8448,17 @@ 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/kunit/

Dang it! I forgot to update the documentation path...

Will fix in next revision.

> +F:	include/kunit/
> +F:	kunit/
> +F:	tools/testing/kunit/
> +
>  KERNEL USERMODE HELPER
>  M:	Luis Chamberlain <mcgrof@kernel.org>
>  L:	linux-kernel@vger.kernel.org
> -- 
> 2.21.0.1020.gf2820cf01a-goog
> 

Re: [PATCH v4 01/18] kunit: test: add KUnit test runner core

[Stephen Boyd]

Quoting Brendan Higgins (2019-05-14 15:16:54)
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> new file mode 100644
> index 0000000000000..e682ea0e1f9a5
> --- /dev/null
> +++ b/include/kunit/test.h
> @@ -0,0 +1,162 @@
[..]
> +/**
> + * 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_module).
> + *
> + * 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! */
> +       spinlock_t lock; /* Gaurds all mutable test state. */
> +       bool success; /* Protected by lock. */

Is this all the spinlock protects? Doesn't seem useful if it's just
protecting access to the variable being set or not because code that
reads it will have a stale view of the value.

> diff --git a/kunit/test.c b/kunit/test.c
> new file mode 100644
> index 0000000000000..86f65ba2bcf92
> --- /dev/null
> +++ b/kunit/test.c
> @@ -0,0 +1,229 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Base unit test (KUnit) API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#include <linux/sched.h>
> +#include <linux/sched/debug.h>
> +#include <kunit/test.h>
> +
[...]
> +
> +size_t kunit_module_counter = 1;

static?

Re: [PATCH v4 02/18] kunit: test: add test resource management API

[Stephen Boyd]

Quoting Brendan Higgins (2019-05-14 15:16:55)
> diff --git a/kunit/test.c b/kunit/test.c
> index 86f65ba2bcf92..a15e6f8c41582 100644
> --- a/kunit/test.c
> +++ b/kunit/test.c
[..]
> +
> +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;
> +       else
> +               return NULL;

Can be written as

	if (res)
		return ....
	return 

and some static analysis tools prefer this.

> +}
> +
> +void kunit_cleanup(struct kunit *test)
> +{
> +       struct kunit_resource *resource, *resource_safe;
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&test->lock, flags);

Ah ok, test->lock is protecting everything now? Does it need to be a
spinlock, or can it be a mutex?

> +       list_for_each_entry_safe(resource,
> +                                resource_safe,
> +                                &test->resources,
> +                                node) {
> +               kunit_free_resource(test, resource);
> +       }
> +       spin_unlock_irqrestore(&test->lock, flags);
> +}
> +

Re: [PATCH v4 03/18] kunit: test: add string_stream a std::stream like string builder

[Stephen Boyd]

Quoting Brendan Higgins (2019-05-14 15:16:56)
> 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>

Is there any reason why we can't use the seqfile API for this? These
both share a similar goal, formatting strings into a buffer to be read
later. Maybe some new APIs would be needed to extract the buffer
differently, but I hope we could share the code.

If it can't be used, can you please add the reasoning to the commit text
here?

Re: [PATCH v4 04/18] kunit: test: add kunit_stream a std::stream like logger

[Stephen Boyd]

Quoting Brendan Higgins (2019-05-14 15:16:57)
> diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
> new file mode 100644
> index 0000000000000..1884f1b550888
> --- /dev/null
> +++ b/kunit/kunit-stream.c
> @@ -0,0 +1,152 @@
> +// 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>
> +
> +static const char *kunit_stream_get_level(struct kunit_stream *this)
> +{
> +       unsigned long flags;
> +       const char *level;
> +
> +       spin_lock_irqsave(&this->lock, flags);
> +       level = this->level;
> +       spin_unlock_irqrestore(&this->lock, flags);
> +
> +       return level;

Please remove this whole function and inline it to the one call-site.

> +}
> +
> +void kunit_stream_set_level(struct kunit_stream *this, const char *level)
> +{
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&this->lock, flags);
> +       this->level = level;
> +       spin_unlock_irqrestore(&this->lock, flags);

I don't get the locking here. What are we protecting against? Are tests
running in parallel using the same kunit_stream? If so, why is the level
changeable in one call and then adding strings is done in a different
function call? It would make sense to combine the level setting and
string adding so that it's one atomic operation if it's truly a parallel
operation, or remove the locking entirely.

> +}
> +
> +void kunit_stream_add(struct kunit_stream *this, const char *fmt, ...)
> +{
> +       va_list args;
> +       struct string_stream *stream = this->internal_stream;
> +
> +       va_start(args, fmt);
> +
> +       if (string_stream_vadd(stream, fmt, args) < 0)
> +               kunit_err(this->test, "Failed to allocate fragment: %s\n", fmt);
> +
> +       va_end(args);
> +}
> +
> +void kunit_stream_append(struct kunit_stream *this,
> +                               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(this->test,
> +                         "Failed to get string from second argument for appending.\n");
> +               return;
> +       }
> +
> +       kunit_stream_add(this, other_content);
> +}
> +
> +void kunit_stream_clear(struct kunit_stream *this)
> +{
> +       string_stream_clear(this->internal_stream);
> +}
> +
> +void kunit_stream_commit(struct kunit_stream *this)

Should this be rather called kunit_stream_flush()?

> +{
> +       struct string_stream *stream = this->internal_stream;
> +       struct string_stream_fragment *fragment;
> +       const char *level;
> +       char *buf;
> +
> +       level = kunit_stream_get_level(this);
> +       if (!level) {
> +               kunit_err(this->test,
> +                         "Stream was committed without a specified log level.\n");

Drop the full-stop?

> +               level = KERN_ERR;
> +               kunit_stream_set_level(this, level);
> +       }
> +
> +       buf = string_stream_get_string(stream);
> +       if (!buf) {
> +               kunit_err(this->test,

Can you grow a local variable for 'this->test'? It's used many times.

Also, 'this' is not very kernel idiomatic. We usually name variables by
their type instead of 'this' which is a keyword in other languages.
Perhaps it could be named 'kstream'?

> +                        "Could not allocate buffer, dumping stream:\n");
> +               list_for_each_entry(fragment, &stream->fragments, node) {
> +                       kunit_err(this->test, fragment->fragment);
> +               }
> +               kunit_err(this->test, "\n");
> +               goto cleanup;
> +       }
> +
> +       kunit_printk(level, this->test, buf);
> +       kfree(buf);
> +
> +cleanup:
> +       kunit_stream_clear(this);
> +}
> +
> +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);

Of course, here it's called 'stream', so maybe it should be 'kstream'
here too.

> +       if (!stream)
> +               return -ENOMEM;
> +
> +       res->allocation = stream;
> +       stream->test = test;
> +       spin_lock_init(&stream->lock);
> +       stream->internal_stream = new_string_stream();

Can new_string_stream() be renamed to alloc_string_stream()? Sorry, I
just see so much C++ isms in here it's hard to read from the kernel
developer perspective.

> +
> +       if (!stream->internal_stream) {

Nitpick: Please join this to the "allocation" event above instead of
keeping it separated.

> +               kfree(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);
> +       }
> +
> +       destroy_string_stream(stream->internal_stream);
> +       kfree(stream);
> +}
> +
> +struct kunit_stream *kunit_new_stream(struct kunit *test)
> +{
> +       struct kunit_resource *res;
> +
> +       res = kunit_alloc_resource(test,
> +                                  kunit_stream_init,
> +                                  kunit_stream_free,
> +                                  test);
> +
> +       if (res)
> +               return res->allocation;
> +       else
> +               return NULL;

Don't have if (...) return ...; else return ..., just return instead of
else.

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Stephen Boyd]

Quoting Brendan Higgins (2019-05-14 15:17:10)
> diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> new file mode 100644
> index 0000000000000..fe0f2bae66085
> --- /dev/null
> +++ b/kernel/sysctl-test.c
> @@ -0,0 +1,293 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * KUnit test of proc sysctl.
> + */
> +
> +#include <kunit/test.h>
> +#include <linux/printk.h>

Is this include used?

> +#include <linux/sysctl.h>
> +#include <linux/uaccess.h>

Is this include used?

> +
> +
> +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> +{
> +       struct ctl_table table = {
> +               .procname = "foo",
> +               .data           = &test_data.int_0001,
> +               .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;
> +
> +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);

Is the casting necessary? Or can the macro do a type coercion of the
second parameter based on the first type?

> +}
> +
> +static void sysctl_test_dointvec_single_less_int_min(struct kunit *test)
> +{
> +       struct ctl_table table = {
> +               .procname = "foo",
> +               .data           = &test_data.int_0001,
> +               .maxlen         = sizeof(int),
> +               .mode           = 0644,
> +               .proc_handler   = proc_dointvec,
> +               .extra1         = &i_zero,
> +               .extra2         = &i_one_hundred,
> +       };
> +       char input[32];
> +       size_t len = sizeof(input) - 1;
> +       loff_t pos = 0;
> +       unsigned long abs_of_less_than_min = (unsigned long)INT_MAX
> +                                            - (INT_MAX + INT_MIN) + 1;
> +
> +       KUNIT_EXPECT_LT(test,
> +                       snprintf(input, sizeof(input), "-%lu",
> +                                abs_of_less_than_min),
> +                       sizeof(input));
> +
> +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> +       KUNIT_EXPECT_EQ(test, -EINVAL,
> +                       proc_dointvec(&table, 1, input, &len, &pos));
> +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> +       KUNIT_EXPECT_EQ(test, 0, *(int *)table.data);
> +}
> +
> +static void sysctl_test_dointvec_single_greater_int_max(struct kunit *test)
> +{
> +       struct ctl_table table = {
> +               .procname = "foo",
> +               .data           = &test_data.int_0001,
> +               .maxlen         = sizeof(int),
> +               .mode           = 0644,
> +               .proc_handler   = proc_dointvec,
> +               .extra1         = &i_zero,
> +               .extra2         = &i_one_hundred,
> +       };
> +       char input[32];
> +       size_t len = sizeof(input) - 1;
> +       loff_t pos = 0;
> +       unsigned long greater_than_max = (unsigned long)INT_MAX + 1;
> +
> +       KUNIT_EXPECT_GT(test, greater_than_max, INT_MAX);
> +       KUNIT_EXPECT_LT(test, snprintf(input, sizeof(input), "%lu",
> +                                      greater_than_max),
> +                       sizeof(input));
> +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> +       KUNIT_EXPECT_EQ(test, -EINVAL,
> +                       proc_dointvec(&table, 1, input, &len, &pos));
> +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> +       KUNIT_EXPECT_EQ(test, 0, *(int *)table.data);
> +}
> +
> +static int sysctl_test_init(struct kunit *test)
> +{
> +       return 0;
> +}
> +
> +/*
> + * This is run once after each test case, see the comment on example_test_module
> + * for more information.
> + */
> +static void sysctl_test_exit(struct kunit *test)
> +{
> +}

Can the above two be omitted? If they can be empty sometimes it would be
nice to avoid the extra symbols and code by letting them be assigned to
NULL in the kunit_module.

> +
> +/*
> + * Here we make a list of all the test cases we want to add to the test module
> + * below.
> + */
> +static struct kunit_case sysctl_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 module.
> +        */
> +       KUNIT_CASE(sysctl_test_dointvec_null_tbl_data),
> +       KUNIT_CASE(sysctl_test_dointvec_table_maxlen_unset),
> +       KUNIT_CASE(sysctl_test_dointvec_table_len_is_zero),
> +       KUNIT_CASE(sysctl_test_dointvec_table_read_but_position_set),
> +       KUNIT_CASE(sysctl_test_dointvec_happy_single_positive),
> +       KUNIT_CASE(sysctl_test_dointvec_happy_single_negative),
> +       KUNIT_CASE(sysctl_test_dointvec_single_less_int_min),
> +       KUNIT_CASE(sysctl_test_dointvec_single_greater_int_max),
> +       {},
> +};
> +
> +/*
> + * This defines a suite or grouping of tests.
> + *
> + * Test cases are defined as belonging to the suite by adding them to
> + * `test_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 module would behave as follows:
> + *
> + * module.init(test);
> + * module.test_case[0](test);
> + * module.exit(test);
> + * module.init(test);
> + * module.test_case[1](test);
> + * module.exit(test);
> + * ...;

This comment (and the one above for "this is a helper") looks generic
and should probably only be in some documentation somewhere and not for
a sysctl test?

> + */
> +static struct kunit_module sysctl_test_module = {
> +       .name = "sysctl_test",
> +       .init = sysctl_test_init,
> +       .exit = sysctl_test_exit,
> +       .test_cases = sysctl_test_cases,
> +};
> +
> +/*
> + * This registers the above test module telling KUnit that this is a suite of
> + * tests that need to be run.
> + */

Same comment about generic comment.

> +module_test(sysctl_test_module);
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index d5a4a4036d2f8..772af4ec70111 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1908,6 +1908,12 @@ config TEST_SYSCTL
>  
>           If unsure, say N.
>  
> +config SYSCTL_KUNIT_TEST
> +       bool "KUnit test for sysctl"

Why not tristate?

> +       depends on KUNIT
> +       help
> +         Enables KUnit sysctl test.
> +

Re: [PATCH v4 01/18] kunit: test: add KUnit test runner core

[Stephen Boyd]

Quoting Brendan Higgins (2019-05-14 15:16:54)
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> new file mode 100644
> index 0000000000000..e682ea0e1f9a5
> --- /dev/null
> +++ b/include/kunit/test.h
> @@ -0,0 +1,162 @@
> +/* 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>
> +#include <linux/slab.h>

Is this include used here?

> +
> +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_module and will be run after the
> + * module's init function and followed by the module'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),
> + *             {},

Nitpick: Please drop the comma on the sentinel so nobody gets ideas to
add another entry after it.

> + *     };
> + *
> + */
> +struct kunit_case {
> +       void (*run_case)(struct kunit *test);
> +       const char name[256];

Maybe 256 can be a #define KUNIT_NAME_MAX_LEN? Or it could just be a
const char pointer to a literal pool? Are unit tests making up names at
runtime?

> +
> +       /* 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_module - 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_module 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_module for KUnit to
> + * run it.
> + */
> +struct kunit_module {
> +       const char name[256];
> +       int (*init)(struct kunit *test);
> +       void (*exit)(struct kunit *test);
> +       struct kunit_case *test_cases;

Can this variable be const? Or we expect test modules to adjust test_cases after
the fact?

> +};
> +
> +/**
> + * 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_module).
> + *
> + * 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! */
> +       spinlock_t lock; /* Gaurds all mutable test state. */
> +       bool success; /* Protected by lock. */
> +};
> +
> +void kunit_init_test(struct kunit *test, const char *name);
> +
> +int kunit_run_tests(struct kunit_module *module);
> +
> +/**
> + * module_test() - used to register a &struct kunit_module with KUnit.
> + * @module: a statically allocated &struct kunit_module.
> + *
> + * Registers @module with the test framework. See &struct kunit_module for more
> + * information.
> + */
> +#define module_test(module) \
> +               static int module_kunit_init##module(void) \
> +               { \
> +                       return kunit_run_tests(&module); \
> +               } \
> +               late_initcall(module_kunit_init##module)

Maybe we need to introduce another initcall level after
late_initcall_sync() for tests? I wonder if there will be tests that
need to run after all other initcalls have run, including late sync
initcalls.

> +
> +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 module 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.
> + *
> + * See kunit_info().

Why? Just write out that it "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.
> + *
> + * See kunit_info().

Same comment.

> + */
> +#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..64480092b2c24
> --- /dev/null
> +++ b/kunit/Kconfig
> @@ -0,0 +1,16 @@
> +#
> +# 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. For more information, please see
> +         Documentation/kunit/

This moved and needs an update.

> +
> +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..86f65ba2bcf92
> --- /dev/null
> +++ b/kunit/test.c
> @@ -0,0 +1,229 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Base unit test (KUnit) API.
> + *
> + * Copyright (C) 2019, Google LLC.
> + * Author: Brendan Higgins <brendanhiggins@google.com>
> + */
> +
> +#include <linux/sched.h>

This include gets removed later in the series, was it ever needed?

> +#include <linux/sched/debug.h>
> +#include <kunit/test.h>
> +
> +static bool kunit_get_success(struct kunit *test)
> +{
> +       unsigned long flags;
> +       bool success;
> +
> +       spin_lock_irqsave(&test->lock, flags);
> +       success = test->success;
> +       spin_unlock_irqrestore(&test->lock, flags);
> +
> +       return success;
> +}
> +
> +static void kunit_set_success(struct kunit *test, bool success)
> +{
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&test->lock, flags);
> +       test->success = success;
> +       spin_unlock_irqrestore(&test->lock, flags);
> +}
> +
> +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 bool kunit_has_printed_tap_version;
> +
> +static void kunit_print_tap_version(void)
> +{
> +       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_module *module)
> +{
> +       kunit_print_tap_version();
> +       kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", module->name);
> +       kunit_printk_emit(LOGLEVEL_INFO,
> +                         "\t1..%zd\n",
> +                         kunit_test_cases_len(module->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_module_has_succeeded(struct kunit_module *module)
> +{
> +       struct kunit_case *test_case;

This can be const?

> +       bool success = true;
> +
> +       for (test_case = module->test_cases; test_case->run_case; test_case++)
> +               if (!test_case->success)
> +                       success = false;

Bail out early here on first "fail" with return false?

> +
> +       return success;
> +}
> +
> +size_t kunit_module_counter = 1;
> +
> +static void kunit_print_subtest_end(struct kunit_module *module)
> +{
> +       kunit_print_ok_not_ok(false,
> +                             kunit_module_has_succeeded(module),
> +                             kunit_module_counter++,
> +                             module->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)
> +{
> +       spin_lock_init(&test->lock);
> +       test->name = name;
> +}
> +
> +/*
> + * Initializes and runs test case. Does not clean up or do post validations.
> + */
> +static void kunit_run_case_internal(struct kunit *test,
> +                                   struct kunit_module *module,
> +                                   struct kunit_case *test_case)
> +{
> +       int ret;
> +
> +       if (module->init) {
> +               ret = module->init(test);
> +               if (ret) {
> +                       kunit_err(test, "failed to initialize: %d\n", ret);
> +                       kunit_set_success(test, false);
> +                       return;
> +               }
> +       }
> +
> +       test_case->run_case(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_module *module,
> +                                  struct kunit_case *test_case)

But test_case isn't used?

> +{
> +       if (module->exit)

Aha, so we don't need empty functions in the sysctl test.

> +               module->exit(test);
> +}
> +
> +/*
> + * Performs all logic to run a test case.
> + */
> +static void kunit_run_case(struct kunit_module *module,
> +                          struct kunit_case *test_case)
> +{
> +       struct kunit test;
> +
> +       kunit_init_test(&test, test_case->name);
> +       kunit_set_success(&test, true);

Can kunit_init_test() also kunit_set_success() to true or false,
depending on what is desired as the initial state?

> +
> +       kunit_run_case_internal(&test, module, test_case);
> +       kunit_run_case_cleanup(&test, module, test_case);

I find this odd, we have run_case_internal() that does two things, init
and run_case, while case_cleanup() does one thing, call module->exit().

Can we just inline all those functions in here so that it looks like
this:

       int ret = 0;

       if (module->init) {
              ret = module->init(test);
               if (ret) {
                       kunit_err(test, "failed to initialize: %d\n", ret);
                       kunit_set_success(&test, false);
               }
       }

       if (!ret)
               test_case->run_case(&test);

       if (module->exit)
               module->exit(&test);

       return kunit_get_success(&test);

Then I don't have to read two more functions to figure out the flow of
running a test case.

> +
> +       test_case->success = kunit_get_success(&test);
> +}
> +
> +int kunit_run_tests(struct kunit_module *module)
> +{
> +       struct kunit_case *test_case;
> +       size_t test_case_count = 1;

Might make sense to assign this to 0 first and then pre-increment so
that test_case_count can't be 1 when there aren't any tests?

> +
> +       kunit_print_subtest_start(module);
> +
> +       for (test_case = module->test_cases; test_case->run_case; test_case++) {
> +               kunit_run_case(module, test_case);
> +               kunit_print_test_case_ok_not_ok(test_case, test_case_count++);

Can this be pushed into kunit_run_case() and have that function take a
test_case_count number? Maybe that would allow us to avoid storing
test_case->success entirely? Assuming that kunit_run_case() returned a
value like success or failure, then yes it would work.

       unsigned int failed = 0;

       for (test_case = module->test_cases; test_case->run_case; test_case++) {
               failed |= kunit_run_case(module, test_case, ++test_case_count);

       kunit_print_ok_not_ok(false,
                             !failed,
                             kunit_module_counter++,
                             module->name);

> +       kunit_print_subtest_end(module);
> +
> +       return 0;
> +}

Re: [PATCH v4 02/18] kunit: test: add test resource management API

[Brendan Higgins]

On Thu, May 16, 2019 at 5:38 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-05-14 15:16:55)
> > diff --git a/kunit/test.c b/kunit/test.c
> > index 86f65ba2bcf92..a15e6f8c41582 100644
> > --- a/kunit/test.c
> > +++ b/kunit/test.c
> [..]
> > +
> > +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;
> > +       else
> > +               return NULL;
>
> Can be written as
>
>         if (res)
>                 return ....
>         return
>
> and some static analysis tools prefer this.

Sounds reasonable, will fix in next revision.

> > +}
> > +
> > +void kunit_cleanup(struct kunit *test)
> > +{
> > +       struct kunit_resource *resource, *resource_safe;
> > +       unsigned long flags;
> > +
> > +       spin_lock_irqsave(&test->lock, flags);
>
> Ah ok, test->lock is protecting everything now? Does it need to be a
> spinlock, or can it be a mutex?

No it needs to be a spin lock. There are some conceivable
circumstances where the test object can be accessed by code in which
it isn't safe to sleep.

> > +       list_for_each_entry_safe(resource,
> > +                                resource_safe,
> > +                                &test->resources,
> > +                                node) {
> > +               kunit_free_resource(test, resource);
> > +       }
> > +       spin_unlock_irqrestore(&test->lock, flags);
> > +}
> > +

Re: [PATCH v4 03/18] kunit: test: add string_stream a std::stream like string builder

[Brendan Higgins]

On Fri, May 17, 2019 at 10:43 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-05-14 15:16:56)
> > 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>
>
> Is there any reason why we can't use the seqfile API for this? These
> both share a similar goal, formatting strings into a buffer to be read
> later. Maybe some new APIs would be needed to extract the buffer
> differently, but I hope we could share the code.

I can see why you are asking. It seems as though they are trying to do
*similar* things, and it seems possible that we might be able to
extract some common functionality out of seq_file that could replace
this; however, it looks like it would be require a significant
refactoring of seq_file to separate out the file system specific bits
from the more general stringbuilder functionality.

In my opinion, a refactoring like this makes no sense in this
patchset; it probably belongs in its own patchset (preferably as a
follow on). I also am not sure if the FS people would appreciate
indirection that serves them no benefit, but I can ask if you like.

> If it can't be used, can you please add the reasoning to the commit text
> here?

Will do.

Thanks!

Re: [PATCH v4 04/18] kunit: test: add kunit_stream a std::stream like logger

[Brendan Higgins]

On Fri, May 17, 2019 at 10:58 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-05-14 15:16:57)
> > diff --git a/kunit/kunit-stream.c b/kunit/kunit-stream.c
> > new file mode 100644
> > index 0000000000000..1884f1b550888
> > --- /dev/null
> > +++ b/kunit/kunit-stream.c
> > @@ -0,0 +1,152 @@
> > +// 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>
> > +
> > +static const char *kunit_stream_get_level(struct kunit_stream *this)
> > +{
> > +       unsigned long flags;
> > +       const char *level;
> > +
> > +       spin_lock_irqsave(&this->lock, flags);
> > +       level = this->level;
> > +       spin_unlock_irqrestore(&this->lock, flags);
> > +
> > +       return level;
>
> Please remove this whole function and inline it to the one call-site.
>
> > +}
> > +
> > +void kunit_stream_set_level(struct kunit_stream *this, const char *level)
> > +{
> > +       unsigned long flags;
> > +
> > +       spin_lock_irqsave(&this->lock, flags);
> > +       this->level = level;
> > +       spin_unlock_irqrestore(&this->lock, flags);
>
> I don't get the locking here. What are we protecting against? Are tests
> running in parallel using the same kunit_stream? If so, why is the level
> changeable in one call and then adding strings is done in a different
> function call? It would make sense to combine the level setting and
> string adding so that it's one atomic operation if it's truly a parallel
> operation, or remove the locking entirely.

I think you are right. I am not sure it makes sense for two separate
threads to share a kunit_stream; even if locked properly, it would end
up printing out corrupted text.

In anycase, I think it makes sense to decide the level when the stream
is allocated which would sidestep this issue entirely.

> > +}
> > +
> > +void kunit_stream_add(struct kunit_stream *this, const char *fmt, ...)
> > +{
> > +       va_list args;
> > +       struct string_stream *stream = this->internal_stream;
> > +
> > +       va_start(args, fmt);
> > +
> > +       if (string_stream_vadd(stream, fmt, args) < 0)
> > +               kunit_err(this->test, "Failed to allocate fragment: %s\n", fmt);
> > +
> > +       va_end(args);
> > +}
> > +
> > +void kunit_stream_append(struct kunit_stream *this,
> > +                               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(this->test,
> > +                         "Failed to get string from second argument for appending.\n");
> > +               return;
> > +       }
> > +
> > +       kunit_stream_add(this, other_content);
> > +}
> > +
> > +void kunit_stream_clear(struct kunit_stream *this)
> > +{
> > +       string_stream_clear(this->internal_stream);
> > +}
> > +
> > +void kunit_stream_commit(struct kunit_stream *this)
>
> Should this be rather called kunit_stream_flush()?

So the intention is that the string in the buffer will not get printed
out until commit is called. In this way, you can build up a message
and then decide not to print it. This is useful when you are parsing
through a lot of data that would be useful in debugging a failing or
broken test, but are not yet sure if it is going to pass or not.

I think flush has the connotation, that you are just forcing the
buffer to get written out now, but that it will happen regardless
eventually, where commit has the correct connotation that you *must*
call it in order to write out the data stored in the buffer.

Seems as though I should probably add this distinction to the
kernel-doc comment.

> > +{
> > +       struct string_stream *stream = this->internal_stream;
> > +       struct string_stream_fragment *fragment;
> > +       const char *level;
> > +       char *buf;
> > +
> > +       level = kunit_stream_get_level(this);
> > +       if (!level) {
> > +               kunit_err(this->test,
> > +                         "Stream was committed without a specified log level.\n");
>
> Drop the full-stop?

Whoops, nice catch. Will fix in next revision.

> > +               level = KERN_ERR;
> > +               kunit_stream_set_level(this, level);
> > +       }
> > +
> > +       buf = string_stream_get_string(stream);
> > +       if (!buf) {
> > +               kunit_err(this->test,
>
> Can you grow a local variable for 'this->test'? It's used many times.

Sure, will fix in next revision.

> Also, 'this' is not very kernel idiomatic. We usually name variables by
> their type instead of 'this' which is a keyword in other languages.
> Perhaps it could be named 'kstream'?

Seems reasonable. Will fix in next revision.

> > +                        "Could not allocate buffer, dumping stream:\n");
> > +               list_for_each_entry(fragment, &stream->fragments, node) {
> > +                       kunit_err(this->test, fragment->fragment);
> > +               }
> > +               kunit_err(this->test, "\n");
> > +               goto cleanup;
> > +       }
> > +
> > +       kunit_printk(level, this->test, buf);
> > +       kfree(buf);
> > +
> > +cleanup:
> > +       kunit_stream_clear(this);
> > +}
> > +
> > +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);
>
> Of course, here it's called 'stream', so maybe it should be 'kstream'
> here too.

Will do.

>
> > +       if (!stream)
> > +               return -ENOMEM;
> > +
> > +       res->allocation = stream;
> > +       stream->test = test;
> > +       spin_lock_init(&stream->lock);
> > +       stream->internal_stream = new_string_stream();
>
> Can new_string_stream() be renamed to alloc_string_stream()? Sorry, I
> just see so much C++ isms in here it's hard to read from the kernel
> developer perspective.

No problem. WIll fix in next revision.

> > +
> > +       if (!stream->internal_stream) {
>
> Nitpick: Please join this to the "allocation" event above instead of
> keeping it separated.

Yeah, that's a lot cleaner. Will do.

> > +               kfree(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);
> > +       }
> > +
> > +       destroy_string_stream(stream->internal_stream);
> > +       kfree(stream);
> > +}
> > +
> > +struct kunit_stream *kunit_new_stream(struct kunit *test)
> > +{
> > +       struct kunit_resource *res;
> > +
> > +       res = kunit_alloc_resource(test,
> > +                                  kunit_stream_init,
> > +                                  kunit_stream_free,
> > +                                  test);
> > +
> > +       if (res)
> > +               return res->allocation;
> > +       else
> > +               return NULL;
>
> Don't have if (...) return ...; else return ..., just return instead of
> else.

Sorry. Will fix.

Thanks!

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Iurii Zaikin]

On Fri, May 17, 2019 at 11:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-05-14 15:17:10)
> > diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> > new file mode 100644
> > index 0000000000000..fe0f2bae66085
> > --- /dev/null
> > +++ b/kernel/sysctl-test.c
> > @@ -0,0 +1,293 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * KUnit test of proc sysctl.
> > + */
> > +
> > +#include <kunit/test.h>
> > +#include <linux/printk.h>
>
> Is this include used?
  Deleted.
>
> > +#include <linux/sysctl.h>
> > +#include <linux/uaccess.h>
>
> Is this include used?
Deleted.
>
> > +
> > +
> > +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> > +{
> > +       struct ctl_table table = {
> > +               .procname = "foo",
> > +               .data           = &test_data.int_0001,
> > +               .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;
> > +
> > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> > +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
>
> Is the casting necessary? Or can the macro do a type coercion of the
> second parameter based on the first type?
 Data field is defined as void* so I believe casting is necessary to
dereference it as a pointer to an array of ints. I don't think the
macro should do any type coercion that == operator wouldn't do.
 I did change the cast to make it more clear that it's a pointer to an
array of ints being dereferenced.
>
> > +}
> > +
> > +static void sysctl_test_dointvec_single_less_int_min(struct kunit *test)
> > +{
> > +       struct ctl_table table = {
> > +               .procname = "foo",
> > +               .data           = &test_data.int_0001,
> > +               .maxlen         = sizeof(int),
> > +               .mode           = 0644,
> > +               .proc_handler   = proc_dointvec,
> > +               .extra1         = &i_zero,
> > +               .extra2         = &i_one_hundred,
> > +       };
> > +       char input[32];
> > +       size_t len = sizeof(input) - 1;
> > +       loff_t pos = 0;
> > +       unsigned long abs_of_less_than_min = (unsigned long)INT_MAX
> > +                                            - (INT_MAX + INT_MIN) + 1;
> > +
> > +       KUNIT_EXPECT_LT(test,
> > +                       snprintf(input, sizeof(input), "-%lu",
> > +                                abs_of_less_than_min),
> > +                       sizeof(input));
> > +
> > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > +       KUNIT_EXPECT_EQ(test, -EINVAL,
> > +                       proc_dointvec(&table, 1, input, &len, &pos));
> > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > +       KUNIT_EXPECT_EQ(test, 0, *(int *)table.data);
> > +}
> > +
> > +static void sysctl_test_dointvec_single_greater_int_max(struct kunit *test)
> > +{
> > +       struct ctl_table table = {
> > +               .procname = "foo",
> > +               .data           = &test_data.int_0001,
> > +               .maxlen         = sizeof(int),
> > +               .mode           = 0644,
> > +               .proc_handler   = proc_dointvec,
> > +               .extra1         = &i_zero,
> > +               .extra2         = &i_one_hundred,
> > +       };
> > +       char input[32];
> > +       size_t len = sizeof(input) - 1;
> > +       loff_t pos = 0;
> > +       unsigned long greater_than_max = (unsigned long)INT_MAX + 1;
> > +
> > +       KUNIT_EXPECT_GT(test, greater_than_max, INT_MAX);
> > +       KUNIT_EXPECT_LT(test, snprintf(input, sizeof(input), "%lu",
> > +                                      greater_than_max),
> > +                       sizeof(input));
> > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > +       KUNIT_EXPECT_EQ(test, -EINVAL,
> > +                       proc_dointvec(&table, 1, input, &len, &pos));
> > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > +       KUNIT_EXPECT_EQ(test, 0, *(int *)table.data);
> > +}
> > +
> > +static int sysctl_test_init(struct kunit *test)
> > +{
> > +       return 0;
> > +}
> > +
> > +/*
> > + * This is run once after each test case, see the comment on example_test_module
> > + * for more information.
> > + */
> > +static void sysctl_test_exit(struct kunit *test)
> > +{
> > +}
> Can the above two be omitted? If they can be empty sometimes it would be
> nice to avoid the extra symbols and code by letting them be assigned to
> NULL in the kunit_module.
 Deleted.
>
> > +
> > +/*
> > + * Here we make a list of all the test cases we want to add to the test module
> > + * below.
> > + */
> > +static struct kunit_case sysctl_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 module.
> > +        */
> > +       KUNIT_CASE(sysctl_test_dointvec_null_tbl_data),
> > +       KUNIT_CASE(sysctl_test_dointvec_table_maxlen_unset),
> > +       KUNIT_CASE(sysctl_test_dointvec_table_len_is_zero),
> > +       KUNIT_CASE(sysctl_test_dointvec_table_read_but_position_set),
> > +       KUNIT_CASE(sysctl_test_dointvec_happy_single_positive),
> > +       KUNIT_CASE(sysctl_test_dointvec_happy_single_negative),
> > +       KUNIT_CASE(sysctl_test_dointvec_single_less_int_min),
> > +       KUNIT_CASE(sysctl_test_dointvec_single_greater_int_max),
> > +       {},
> > +};
> > +
> > +/*
> > + * This defines a suite or grouping of tests.
> > + *
> > + * Test cases are defined as belonging to the suite by adding them to
> > + * `test_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 module would behave as follows:
> > + *
> > + * module.init(test);
> > + * module.test_case[0](test);
> > + * module.exit(test);
> > + * module.init(test);
> > + * module.test_case[1](test);
> > + * module.exit(test);
> > + * ...;
>
> This comment (and the one above for "this is a helper") looks generic
> and should probably only be in some documentation somewhere and not for
> a sysctl test?
>
Deleted.
> > + */
> > +static struct kunit_module sysctl_test_module = {
> > +       .name = "sysctl_test",
> > +       .init = sysctl_test_init,
> > +       .exit = sysctl_test_exit,
> > +       .test_cases = sysctl_test_cases,
> > +};
> > +
> > +/*
> > + * This registers the above test module telling KUnit that this is a suite of
> > + * tests that need to be run.
> > + */
>
> Same comment about generic comment.
>
Deleted.
> > +module_test(sysctl_test_module);
> > diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> > index d5a4a4036d2f8..772af4ec70111 100644
> > --- a/lib/Kconfig.debug
> > +++ b/lib/Kconfig.debug
> > @@ -1908,6 +1908,12 @@ config TEST_SYSCTL
> >
> >           If unsure, say N.
> >
> > +config SYSCTL_KUNIT_TEST
> > +       bool "KUnit test for sysctl"
>
> Why not tristate?
>
I don't believe KUnit as a module is currently supported.
> > +       depends on KUNIT
> > +       help
> > +         Enables KUnit sysctl test.
> > +

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Stephen Boyd]

Quoting Iurii Zaikin (2019-06-05 18:29:42)
> On Fri, May 17, 2019 at 11:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
> >
> > Quoting Brendan Higgins (2019-05-14 15:17:10)
> > > diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> > > new file mode 100644
> > > index 0000000000000..fe0f2bae66085
> > > --- /dev/null
> > > +++ b/kernel/sysctl-test.c
> > > +
> > > +
> > > +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> > > +{
> > > +       struct ctl_table table = {
> > > +               .procname = "foo",
> > > +               .data           = &test_data.int_0001,
> > > +               .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;
> > > +
> > > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > > +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> > > +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
> >
> > Is the casting necessary? Or can the macro do a type coercion of the
> > second parameter based on the first type?
>  Data field is defined as void* so I believe casting is necessary to
> dereference it as a pointer to an array of ints. I don't think the
> macro should do any type coercion that == operator wouldn't do.
>  I did change the cast to make it more clear that it's a pointer to an
> array of ints being dereferenced.

Ok, I still wonder if we should make KUNIT_EXPECT_EQ check the types on
both sides and cause a build warning/error if the types aren't the same.
This would be similar to our min/max macros that complain about
mismatched types in the comparisons. Then if a test developer needs to
convert one type or the other they could do so with a
KUNIT_EXPECT_EQ_T() macro that lists the types to coerce both sides to
explicitly.

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Brendan Higgins]

On Fri, Jun 7, 2019 at 12:00 PM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Iurii Zaikin (2019-06-05 18:29:42)
> > On Fri, May 17, 2019 at 11:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Brendan Higgins (2019-05-14 15:17:10)
> > > > diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> > > > new file mode 100644
> > > > index 0000000000000..fe0f2bae66085
> > > > --- /dev/null
> > > > +++ b/kernel/sysctl-test.c
> > > > +
> > > > +
> > > > +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> > > > +{
> > > > +       struct ctl_table table = {
> > > > +               .procname = "foo",
> > > > +               .data           = &test_data.int_0001,
> > > > +               .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;
> > > > +
> > > > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > > > +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> > > > +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
> > >
> > > Is the casting necessary? Or can the macro do a type coercion of the
> > > second parameter based on the first type?
> >  Data field is defined as void* so I believe casting is necessary to
> > dereference it as a pointer to an array of ints. I don't think the
> > macro should do any type coercion that == operator wouldn't do.
> >  I did change the cast to make it more clear that it's a pointer to an
> > array of ints being dereferenced.
>
> Ok, I still wonder if we should make KUNIT_EXPECT_EQ check the types on
> both sides and cause a build warning/error if the types aren't the same.
> This would be similar to our min/max macros that complain about
> mismatched types in the comparisons. Then if a test developer needs to
> convert one type or the other they could do so with a
> KUNIT_EXPECT_EQ_T() macro that lists the types to coerce both sides to
> explicitly.

Good point. I would definitely like to do this, for me it is only a
question of how difficult it would be to make all that happen.

We will investigate and report back on it.

Thanks for the suggestion! It's a really good idea!

Cheers

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Brendan Higgins]

On Fri, Jun 07, 2019 at 12:00:47PM -0700, Stephen Boyd wrote:
> Quoting Iurii Zaikin (2019-06-05 18:29:42)
> > On Fri, May 17, 2019 at 11:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
> > >
> > > Quoting Brendan Higgins (2019-05-14 15:17:10)
> > > > diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> > > > new file mode 100644
> > > > index 0000000000000..fe0f2bae66085
> > > > --- /dev/null
> > > > +++ b/kernel/sysctl-test.c
> > > > +
> > > > +
> > > > +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> > > > +{
> > > > +       struct ctl_table table = {
> > > > +               .procname = "foo",
> > > > +               .data           = &test_data.int_0001,
> > > > +               .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;
> > > > +
> > > > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > > > +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> > > > +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
> > >
> > > Is the casting necessary? Or can the macro do a type coercion of the
> > > second parameter based on the first type?
> >  Data field is defined as void* so I believe casting is necessary to
> > dereference it as a pointer to an array of ints. I don't think the
> > macro should do any type coercion that == operator wouldn't do.
> >  I did change the cast to make it more clear that it's a pointer to an
> > array of ints being dereferenced.
> 
> Ok, I still wonder if we should make KUNIT_EXPECT_EQ check the types on
> both sides and cause a build warning/error if the types aren't the same.
> This would be similar to our min/max macros that complain about
> mismatched types in the comparisons. Then if a test developer needs to
> convert one type or the other they could do so with a
> KUNIT_EXPECT_EQ_T() macro that lists the types to coerce both sides to
> explicitly.

Do you think it would be better to do a phony compare similar to how
min/max used to work prior to 4.17, or to use the new __typecheck(...)
macro? This might seem like a dumb question (and maybe it is), but Iurii
and I thought the former created an error message that was a bit easier
to understand, whereas __typecheck is obviously superior in terms of
code reuse.

This is what we are thinking right now; if you don't have any complaints
I will squash it into the relevant commits on the next revision:
---
From: Iurii Zaikin <yzaikin@google.com>

Adds a warning message when comparing values of different types similar
to what min() / max() macros do.

Signed-off-by: Iurii Zaikin <yzaikin@google.com>
---
 include/kunit/test.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 511c9e85401a6..791e22fba5620 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -335,6 +335,13 @@ void __printf(3, 4) kunit_printk(const char *level,
 #define kunit_err(test, fmt, ...) \
 		kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)
 
+/*
+ * 'Unnecessary' cast serves to generate a compile-time warning in case
+ * of comparing incompatible types. Inspired by include/linux/kernel.h
+ */
+#define __kunit_typecheck(lhs, rhs) \
+	((void) (&(lhs) == &(rhs)))
+
 static inline struct kunit_stream *kunit_expect_start(struct kunit *test,
 						      const char *file,
 						      const char *line)
@@ -514,6 +521,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test,
 #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,		       \
@@ -524,6 +532,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test,
 #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,		       \
@@ -538,6 +547,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test,
 #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,			       \
@@ -553,6 +563,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test,
 				    ...) 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,		       \
@@ -1013,6 +1024,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test,
 #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,		       \
@@ -1023,6 +1035,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test,
 #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,		       \
@@ -1037,6 +1050,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test,
 #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,		       \
@@ -1051,6 +1065,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test,
 				    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,		       \
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Stephen Boyd]

Quoting Brendan Higgins (2019-06-11 10:58:30)
> On Fri, Jun 07, 2019 at 12:00:47PM -0700, Stephen Boyd wrote:
> > Quoting Iurii Zaikin (2019-06-05 18:29:42)
> > > On Fri, May 17, 2019 at 11:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
> > > >
> > > > Quoting Brendan Higgins (2019-05-14 15:17:10)
> > > > > diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> > > > > new file mode 100644
> > > > > index 0000000000000..fe0f2bae66085
> > > > > --- /dev/null
> > > > > +++ b/kernel/sysctl-test.c
> > > > > +
> > > > > +
> > > > > +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> > > > > +{
> > > > > +       struct ctl_table table = {
> > > > > +               .procname = "foo",
> > > > > +               .data           = &test_data.int_0001,
> > > > > +               .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;
> > > > > +
> > > > > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > > > > +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> > > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> > > > > +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
> > > >
> > > > Is the casting necessary? Or can the macro do a type coercion of the
> > > > second parameter based on the first type?
> > >  Data field is defined as void* so I believe casting is necessary to
> > > dereference it as a pointer to an array of ints. I don't think the
> > > macro should do any type coercion that == operator wouldn't do.
> > >  I did change the cast to make it more clear that it's a pointer to an
> > > array of ints being dereferenced.
> > 
> > Ok, I still wonder if we should make KUNIT_EXPECT_EQ check the types on
> > both sides and cause a build warning/error if the types aren't the same.
> > This would be similar to our min/max macros that complain about
> > mismatched types in the comparisons. Then if a test developer needs to
> > convert one type or the other they could do so with a
> > KUNIT_EXPECT_EQ_T() macro that lists the types to coerce both sides to
> > explicitly.
> 
> Do you think it would be better to do a phony compare similar to how
> min/max used to work prior to 4.17, or to use the new __typecheck(...)
> macro? This might seem like a dumb question (and maybe it is), but Iurii
> and I thought the former created an error message that was a bit easier
> to understand, whereas __typecheck is obviously superior in terms of
> code reuse.
> 
> This is what we are thinking right now; if you don't have any complaints
> I will squash it into the relevant commits on the next revision:

Can you provide the difference in error messages and describe that in
the commit text? The commit message is where you "sell" the patch, so
being able to compare the tradeoff of having another macro to do type
comparisons vs. reusing the one that's there in kernel.h would be useful
to allay concerns that we're duplicating logic for better error
messages.

Honestly, I'd prefer we just use the macros that we've developed in
kernel.h to do comparisons here so that we can get code reuse, but more
importantly so that we don't trip over problems that caused those macros
to be created in the first place. If the error message is bad, perhaps
that can be fixed with some sort of compiler directive to make the error
message a little more useful, i.e. compiletime_warning() thrown into
__typecheck() or something.

> ---
> From: Iurii Zaikin <yzaikin@google.com>
> 
> Adds a warning message when comparing values of different types similar
> to what min() / max() macros do.
> 
> Signed-off-by: Iurii Zaikin <yzaikin@google.com>

Re: [PATCH v4 17/18] kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec()

[Brendan Higgins]

On Tue, Jun 11, 2019 at 11:50 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-06-11 10:58:30)
> > On Fri, Jun 07, 2019 at 12:00:47PM -0700, Stephen Boyd wrote:
> > > Quoting Iurii Zaikin (2019-06-05 18:29:42)
> > > > On Fri, May 17, 2019 at 11:22 AM Stephen Boyd <sboyd@kernel.org> wrote:
> > > > >
> > > > > Quoting Brendan Higgins (2019-05-14 15:17:10)
> > > > > > diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
> > > > > > new file mode 100644
> > > > > > index 0000000000000..fe0f2bae66085
> > > > > > --- /dev/null
> > > > > > +++ b/kernel/sysctl-test.c
> > > > > > +
> > > > > > +
> > > > > > +static void sysctl_test_dointvec_happy_single_negative(struct kunit *test)
> > > > > > +{
> > > > > > +       struct ctl_table table = {
> > > > > > +               .procname = "foo",
> > > > > > +               .data           = &test_data.int_0001,
> > > > > > +               .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;
> > > > > > +
> > > > > > +       table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);
> > > > > > +       KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));
> > > > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);
> > > > > > +       KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);
> > > > > > +       KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);
> > > > >
> > > > > Is the casting necessary? Or can the macro do a type coercion of the
> > > > > second parameter based on the first type?
> > > >  Data field is defined as void* so I believe casting is necessary to
> > > > dereference it as a pointer to an array of ints. I don't think the
> > > > macro should do any type coercion that == operator wouldn't do.
> > > >  I did change the cast to make it more clear that it's a pointer to an
> > > > array of ints being dereferenced.
> > >
> > > Ok, I still wonder if we should make KUNIT_EXPECT_EQ check the types on
> > > both sides and cause a build warning/error if the types aren't the same.
> > > This would be similar to our min/max macros that complain about
> > > mismatched types in the comparisons. Then if a test developer needs to
> > > convert one type or the other they could do so with a
> > > KUNIT_EXPECT_EQ_T() macro that lists the types to coerce both sides to
> > > explicitly.
> >
> > Do you think it would be better to do a phony compare similar to how
> > min/max used to work prior to 4.17, or to use the new __typecheck(...)
> > macro? This might seem like a dumb question (and maybe it is), but Iurii
> > and I thought the former created an error message that was a bit easier
> > to understand, whereas __typecheck is obviously superior in terms of
> > code reuse.
> >
> > This is what we are thinking right now; if you don't have any complaints
> > I will squash it into the relevant commits on the next revision:
>
> Can you provide the difference in error messages and describe that in
> the commit text? The commit message is where you "sell" the patch, so
> being able to compare the tradeoff of having another macro to do type
> comparisons vs. reusing the one that's there in kernel.h would be useful
> to allay concerns that we're duplicating logic for better error
> messages.

Oh sorry, I didn't think too hard about the commit message since I
figured it would get split up and squashed into the existing commits.
I just wanted to get it out sooner to discuss this before I post the
next revision (probably later this week).

> Honestly, I'd prefer we just use the macros that we've developed in
> kernel.h to do comparisons here so that we can get code reuse, but more
> importantly so that we don't trip over problems that caused those macros
> to be created in the first place. If the error message is bad, perhaps
> that can be fixed with some sort of compiler directive to make the error
> message a little more useful, i.e. compiletime_warning() thrown into
> __typecheck() or something.

That's a good point. I have no qualms sticking with __typecheck(...)
for now; if we later feel that it is causing problems, we can always
fix it later by supplying our own warning in the manner you suggest.

Iurii, do you have any additional thoughts on this?

>
> > ---
> > From: Iurii Zaikin <yzaikin@google.com>
> >
> > Adds a warning message when comparing values of different types similar
> > to what min() / max() macros do.
> >
> > Signed-off-by: Iurii Zaikin <yzaikin@google.com>

Re: [PATCH v4 01/18] kunit: test: add KUnit test runner core

[Brendan Higgins]

On Fri, May 17, 2019 at 11:53 AM Stephen Boyd <sboyd@kernel.org> wrote:
>
> Quoting Brendan Higgins (2019-05-14 15:16:54)
> > diff --git a/include/kunit/test.h b/include/kunit/test.h
> > new file mode 100644
> > index 0000000000000..e682ea0e1f9a5
> > --- /dev/null
> > +++ b/include/kunit/test.h
> > @@ -0,0 +1,162 @@
> > +/* 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>
> > +#include <linux/slab.h>
>
> Is this include used here?

Err, it is used in the very next commit in the sequence. Sorry, I will
add it in the commit that actually uses it in the next revision.

> > +
> > +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_module and will be run after the
> > + * module's init function and followed by the module'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),
> > + *             {},
>
> Nitpick: Please drop the comma on the sentinel so nobody gets ideas to
> add another entry after it.

Good idea. Will fix here and elsewhere.

> > + *     };
> > + *
> > + */
> > +struct kunit_case {
> > +       void (*run_case)(struct kunit *test);
> > +       const char name[256];
>
> Maybe 256 can be a #define KUNIT_NAME_MAX_LEN? Or it could just be a
> const char pointer to a literal pool? Are unit tests making up names at
> runtime?

Yeah, sorry, I forgot why I did it this way in the first place. Will
fix in next revision.

> > +
> > +       /* 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_module - 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_module 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_module for KUnit to
> > + * run it.
> > + */
> > +struct kunit_module {
> > +       const char name[256];
> > +       int (*init)(struct kunit *test);
> > +       void (*exit)(struct kunit *test);
> > +       struct kunit_case *test_cases;
>
> Can this variable be const? Or we expect test modules to adjust test_cases after
> the fact?

I understand why it would be nice to do it that way, but we store the
failed result on test cases; I don't think it really makes sense to
have another parallel data structure just for the results on each test
case.

> > +};
> > +
> > +/**
> > + * 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_module).
> > + *
> > + * 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! */
> > +       spinlock_t lock; /* Gaurds all mutable test state. */
> > +       bool success; /* Protected by lock. */
> > +};
> > +
> > +void kunit_init_test(struct kunit *test, const char *name);
> > +
> > +int kunit_run_tests(struct kunit_module *module);
> > +
> > +/**
> > + * module_test() - used to register a &struct kunit_module with KUnit.
> > + * @module: a statically allocated &struct kunit_module.
> > + *
> > + * Registers @module with the test framework. See &struct kunit_module for more
> > + * information.
> > + */
> > +#define module_test(module) \
> > +               static int module_kunit_init##module(void) \
> > +               { \
> > +                       return kunit_run_tests(&module); \
> > +               } \
> > +               late_initcall(module_kunit_init##module)
>
> Maybe we need to introduce another initcall level after
> late_initcall_sync() for tests? I wonder if there will be tests that
> need to run after all other initcalls have run, including late sync
> initcalls.

Yeah, I have another patch ready to go to do that. I guess I just
figured that was something that could lead to a lot of bikeshedding
that I wanted to avoid in the initial patchset.

Nevertheless, I can add it in if you feel it is better to discuss now.

> > +
> > +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 module 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.
> > + *
> > + * See kunit_info().
>
> Why? Just write out that it "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.
> > + *
> > + * See kunit_info().
>
> Same comment.
>
> > + */
> > +#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..64480092b2c24
> > --- /dev/null
> > +++ b/kunit/Kconfig
> > @@ -0,0 +1,16 @@
> > +#
> > +# 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. For more information, please see
> > +         Documentation/kunit/
>
> This moved and needs an update.
>
> > +
> > +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..86f65ba2bcf92
> > --- /dev/null
> > +++ b/kunit/test.c
> > @@ -0,0 +1,229 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Base unit test (KUnit) API.
> > + *
> > + * Copyright (C) 2019, Google LLC.
> > + * Author: Brendan Higgins <brendanhiggins@google.com>
> > + */
> > +
> > +#include <linux/sched.h>
>
> This include gets removed later in the series, was it ever needed?

Nope, that was a mistake. Sorry.

> > +#include <linux/sched/debug.h>
> > +#include <kunit/test.h>
> > +
> > +static bool kunit_get_success(struct kunit *test)
> > +{
> > +       unsigned long flags;
> > +       bool success;
> > +
> > +       spin_lock_irqsave(&test->lock, flags);
> > +       success = test->success;
> > +       spin_unlock_irqrestore(&test->lock, flags);
> > +
> > +       return success;
> > +}
> > +
> > +static void kunit_set_success(struct kunit *test, bool success)
> > +{
> > +       unsigned long flags;
> > +
> > +       spin_lock_irqsave(&test->lock, flags);
> > +       test->success = success;
> > +       spin_unlock_irqrestore(&test->lock, flags);
> > +}
> > +
> > +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 bool kunit_has_printed_tap_version;
> > +
> > +static void kunit_print_tap_version(void)
> > +{
> > +       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_module *module)
> > +{
> > +       kunit_print_tap_version();
> > +       kunit_printk_emit(LOGLEVEL_INFO, "\t# Subtest: %s\n", module->name);
> > +       kunit_printk_emit(LOGLEVEL_INFO,
> > +                         "\t1..%zd\n",
> > +                         kunit_test_cases_len(module->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_module_has_succeeded(struct kunit_module *module)
> > +{
> > +       struct kunit_case *test_case;
>
> This can be const?

Yep, nice catch.

> > +       bool success = true;
> > +
> > +       for (test_case = module->test_cases; test_case->run_case; test_case++)
> > +               if (!test_case->success)
> > +                       success = false;
>
> Bail out early here on first "fail" with return false?

Will fix on next revision.

> > +
> > +       return success;
> > +}
> > +
> > +size_t kunit_module_counter = 1;
> > +
> > +static void kunit_print_subtest_end(struct kunit_module *module)
> > +{
> > +       kunit_print_ok_not_ok(false,
> > +                             kunit_module_has_succeeded(module),
> > +                             kunit_module_counter++,
> > +                             module->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)
> > +{
> > +       spin_lock_init(&test->lock);
> > +       test->name = name;
> > +}
> > +
> > +/*
> > + * Initializes and runs test case. Does not clean up or do post validations.
> > + */
> > +static void kunit_run_case_internal(struct kunit *test,
> > +                                   struct kunit_module *module,
> > +                                   struct kunit_case *test_case)
> > +{
> > +       int ret;
> > +
> > +       if (module->init) {
> > +               ret = module->init(test);
> > +               if (ret) {
> > +                       kunit_err(test, "failed to initialize: %d\n", ret);
> > +                       kunit_set_success(test, false);
> > +                       return;
> > +               }
> > +       }
> > +
> > +       test_case->run_case(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_module *module,
> > +                                  struct kunit_case *test_case)
>
> But test_case isn't used?

Whoops, will fix.

> > +{
> > +       if (module->exit)
>
> Aha, so we don't need empty functions in the sysctl test.

Nope, sorry about that. That will be fixed in the next revision.

> > +               module->exit(test);
> > +}
> > +
> > +/*
> > + * Performs all logic to run a test case.
> > + */
> > +static void kunit_run_case(struct kunit_module *module,
> > +                          struct kunit_case *test_case)
> > +{
> > +       struct kunit test;
> > +
> > +       kunit_init_test(&test, test_case->name);
> > +       kunit_set_success(&test, true);
>
> Can kunit_init_test() also kunit_set_success() to true or false,
> depending on what is desired as the initial state?
>
> > +
> > +       kunit_run_case_internal(&test, module, test_case);
> > +       kunit_run_case_cleanup(&test, module, test_case);
>
> I find this odd, we have run_case_internal() that does two things, init
> and run_case, while case_cleanup() does one thing, call module->exit().
>
> Can we just inline all those functions in here so that it looks like
> this:
>
>        int ret = 0;
>
>        if (module->init) {
>               ret = module->init(test);
>                if (ret) {
>                        kunit_err(test, "failed to initialize: %d\n", ret);
>                        kunit_set_success(&test, false);
>                }
>        }
>
>        if (!ret)
>                test_case->run_case(&test);
>
>        if (module->exit)
>                module->exit(&test);
>
>        return kunit_get_success(&test);
>
> Then I don't have to read two more functions to figure out the flow of
> running a test case.

Sorry about that. A lot more logic gets added to running test cases
later on in this patchset. This logic added "later" is actually older
than what's here, so I basically "unrefactored" something I had
already written to get this earlier patch.

In anycase, you are right; these little tiny functions don't make any
sense (yet); I will remove them in the next revision (and let the
later patch make these changes in a  more organic looking way).

>
> > +
> > +       test_case->success = kunit_get_success(&test);
> > +}
> > +
> > +int kunit_run_tests(struct kunit_module *module)
> > +{
> > +       struct kunit_case *test_case;
> > +       size_t test_case_count = 1;
>
> Might make sense to assign this to 0 first and then pre-increment so
> that test_case_count can't be 1 when there aren't any tests?

No, sorry, this is actually specified by the Test Anything Protocol
(TAP); it indexes it's tests starting at 1; not what I would have
done, but we (Greg, Frank, myself, and others) previously agreed that
KUnit should follow TAP[1].

Maybe the name of this variable is a bit misleading since it is the
"test number" or test index. Would `test_case_number` be better?

> > +
> > +       kunit_print_subtest_start(module);
> > +
> > +       for (test_case = module->test_cases; test_case->run_case; test_case++) {
> > +               kunit_run_case(module, test_case);
> > +               kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
>
> Can this be pushed into kunit_run_case() and have that function take a
> test_case_count number? Maybe that would allow us to avoid storing
> test_case->success entirely? Assuming that kunit_run_case() returned a
> value like success or failure, then yes it would work.

Eh, I would prefer not to do that. I like keeping the
printing/reporting functions as orthogonal as possible; it kind of
mirrors the parsing logic on the test harness script side, and will
also be easier to pull out when I go back to improve the expectation
failure reporting when I get around to that later. Even if I never get
around to that, I think this will be much easier for me to maintain.

>        unsigned int failed = 0;
>
>        for (test_case = module->test_cases; test_case->run_case; test_case++) {
>                failed |= kunit_run_case(module, test_case, ++test_case_count);
>
>        kunit_print_ok_not_ok(false,
>                              !failed,
>                              kunit_module_counter++,
>                              module->name);
>
> > +       kunit_print_subtest_end(module);
> > +
> > +       return 0;
> > +}

[1] https://github.com/TestAnything/Specification/blob/tap-14-specification/specification.md#the-test-line