[PATCH v4 kunit-next 0/3] kunit: add debugfs representation to show results

[PATCH v4 kunit-next 0/3] kunit: add debugfs representation to show results

[Alan Maguire]

When kunit tests are run on native (i.e. non-UML) environments, the results
of test execution are often intermixed with dmesg output.  This patch
series attempts to solve this by providing a debugfs representation
of the results of the last test run, available as

/sys/kernel/debug/kunit/<testsuite>/results

Changes since v3:

- added CONFIG_KUNIT_DEBUGFS to support conditional compilation of debugfs
  representation, including string logging (Frank, patch 1)
- removed unneeded NULL check for test_case in kunit_suite_for_each_test_case()
  (Frank, patch 1)
- added kunit log test to verify logging multiple strings works
  (Frank, patch 2)
- rephrased description of results file (Frank, patch 3)

Changes since v2:

- updated kunit_status2str() to kunit_status_to_string() and made it
  static inline in include/kunit/test.h (Brendan)
- added log string to struct kunit_suite and kunit_case, with log
  pointer in struct kunit pointing at the case log.  This allows us
  to collect kunit_[err|info|warning]() messages at the same time
  as we printk() them.  This solves for the most part the sharing
  of log messages between test execution and debugfs since we
  just print the suite log (which contains the test suite preamble)
  and the individual test logs.  The only exception is the suite-level
  status, which we cannot store in the suite log as it would mean
  we'd print the suite and its status prior to the suite's results.
  (Brendan, patch 1)
- dropped debugfs-based kunit run patch for now so as not to cause
  problems with tests currently under development (Brendan)
- fixed doc issues with code block (Brendan, patch 3)

Changes since v1:
 - trimmed unneeded include files in lib/kunit/debugfs.c (Greg)
 - renamed global debugfs functions to be prefixed with kunit_ (Greg)
 - removed error checking for debugfs operations (Greg)

Alan Maguire (3):
  kunit: add debugfs /sys/kernel/debug/kunit/<suite>/results display
  kunit: add log test
  kunit: update documentation to describe debugfs representation

 Documentation/dev-tools/kunit/usage.rst |  13 ++++
 include/kunit/test.h                    |  54 +++++++++++---
 lib/kunit/Kconfig                       |   8 +++
 lib/kunit/Makefile                      |   4 ++
 lib/kunit/debugfs.c                     | 116 ++++++++++++++++++++++++++++++
 lib/kunit/debugfs.h                     |  30 ++++++++
 lib/kunit/kunit-test.c                  |  31 +++++++-
 lib/kunit/test.c                        | 122 ++++++++++++++++++++++++--------
 8 files changed, 336 insertions(+), 42 deletions(-)
 create mode 100644 lib/kunit/debugfs.c
 create mode 100644 lib/kunit/debugfs.h

-- 
1.8.3.1

[PATCH v4 kunit-next 1/3] kunit: add debugfs /sys/kernel/debug/kunit/<suite>/results display

[Alan Maguire]

add debugfs support for displaying kunit test suite results; this is
especially useful for module-loaded tests to allow disentangling of
test result display from other dmesg events.  debugfs support is
provided if CONFIG_KUNIT_DEBUGFS=y.

As well as printk()ing messages, we append them to a per-test log.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
---
 include/kunit/test.h   |  54 ++++++++++++++++++----
 lib/kunit/Kconfig      |   8 ++++
 lib/kunit/Makefile     |   4 ++
 lib/kunit/debugfs.c    | 116 ++++++++++++++++++++++++++++++++++++++++++++++
 lib/kunit/debugfs.h    |  30 ++++++++++++
 lib/kunit/kunit-test.c |   4 +-
 lib/kunit/test.c       | 122 ++++++++++++++++++++++++++++++++++++-------------
 7 files changed, 297 insertions(+), 41 deletions(-)
 create mode 100644 lib/kunit/debugfs.c
 create mode 100644 lib/kunit/debugfs.h

diff --git a/include/kunit/test.h b/include/kunit/test.h
index 2dfb550..7ce5125 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -81,6 +81,9 @@ struct kunit_resource {
 
 struct kunit;
 
+/* Size of log associated with test. */
+#define KUNIT_LOG_SIZE	512
+
 /**
  * struct kunit_case - represents an individual test case.
  *
@@ -123,8 +126,14 @@ struct kunit_case {
 
 	/* private: internal use only. */
 	bool success;
+	char *log;
 };
 
+static inline char *kunit_status_to_string(bool status)
+{
+	return status ? "ok" : "not ok";
+}
+
 /**
  * KUNIT_CASE - A helper for creating a &struct kunit_case
  *
@@ -157,6 +166,10 @@ struct kunit_suite {
 	int (*init)(struct kunit *test);
 	void (*exit)(struct kunit *test);
 	struct kunit_case *test_cases;
+
+	/* private - internal use only */
+	struct dentry *debugfs;
+	char *log;
 };
 
 /**
@@ -175,6 +188,7 @@ struct kunit {
 
 	/* private: internal use only. */
 	const char *name; /* Read only after initialization! */
+	char *log; /* Points at case log after initialization */
 	struct kunit_try_catch try_catch;
 	/*
 	 * success starts as true, and may only be set to false during a
@@ -193,10 +207,19 @@ struct kunit {
 	struct list_head resources; /* Protected by lock. */
 };
 
-void kunit_init_test(struct kunit *test, const char *name);
+void kunit_init_test(struct kunit *test, const char *name, char *log);
 
 int kunit_run_tests(struct kunit_suite *suite);
 
+size_t kunit_suite_num_test_cases(struct kunit_suite *suite);
+
+unsigned int kunit_test_case_num(struct kunit_suite *suite,
+				 struct kunit_case *test_case);
+
+int __kunit_test_suites_init(struct kunit_suite **suites);
+
+void __kunit_test_suites_exit(struct kunit_suite **suites);
+
 /**
  * kunit_test_suites() - used to register one or more &struct kunit_suite
  *			 with KUnit.
@@ -226,20 +249,22 @@ struct kunit {
 	static struct kunit_suite *suites[] = { __VA_ARGS__, NULL};	\
 	static int kunit_test_suites_init(void)				\
 	{								\
-		unsigned int i;						\
-		for (i = 0; suites[i] != NULL; i++)			\
-			kunit_run_tests(suites[i]);			\
-		return 0;						\
+		return __kunit_test_suites_init(suites);		\
 	}								\
 	late_initcall(kunit_test_suites_init);				\
 	static void __exit kunit_test_suites_exit(void)			\
 	{								\
-		return;							\
+		return __kunit_test_suites_exit(suites);		\
 	}								\
 	module_exit(kunit_test_suites_exit)
 
 #define kunit_test_suite(suite)	kunit_test_suites(&suite)
 
+#define kunit_suite_for_each_test_case(suite, test_case)		\
+	for (test_case = suite->test_cases; test_case->run_case; test_case++)
+
+bool kunit_suite_has_succeeded(struct kunit_suite *suite);
+
 /*
  * Like kunit_alloc_resource() below, but returns the struct kunit_resource
  * object that contains the allocation. This is mostly for testing purposes.
@@ -356,8 +381,21 @@ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp)
 
 void kunit_cleanup(struct kunit *test);
 
-#define kunit_printk(lvl, test, fmt, ...) \
-	printk(lvl "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)
+/*
+ * printk and log to per-test or per-suite log buffer.  Logging only done
+ * if CONFIG_KUNIT_DEBUGFS is 'y'; if it is 'n', no log is allocated/used.
+ */
+#define kunit_log(lvl, test_or_suite, fmt, ...)				\
+	do {								\
+		printk(lvl fmt, ##__VA_ARGS__);				\
+		if ((test_or_suite)->log)				\
+			snprintf((test_or_suite)->log, KUNIT_LOG_SIZE,	\
+				 "%s" fmt "\n",				\
+				 (test_or_suite)->log, ##__VA_ARGS__);	\
+	} while (0)
+
+#define kunit_printk(lvl, test, fmt, ...)				\
+	kunit_log(lvl, test, "\t# %s: " fmt, (test)->name, ##__VA_ARGS__)
 
 /**
  * kunit_info() - Prints an INFO level message associated with @test.
diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
index 065aa16..95d12e3 100644
--- a/lib/kunit/Kconfig
+++ b/lib/kunit/Kconfig
@@ -14,6 +14,14 @@ menuconfig KUNIT
 
 if KUNIT
 
+config KUNIT_DEBUGFS
+	bool "KUnit - Enable /sys/kernel/debug/kunit debugfs representation"
+	help
+	  Enable debugfs representation for kunit.  Currently this consists
+	  of /sys/kernel/debug/kunit/<test_suite>/results files for each
+	  test suite, which allow users to see results of the last test suite
+	  run that occurred.
+
 config KUNIT_TEST
 	tristate "KUnit test for KUnit"
 	help
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile
index fab5564..724b943 100644
--- a/lib/kunit/Makefile
+++ b/lib/kunit/Makefile
@@ -5,6 +5,10 @@ kunit-objs +=				test.o \
 					assert.o \
 					try-catch.o
 
+ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
+kunit-objs +=				debugfs.o
+endif
+
 obj-$(CONFIG_KUNIT_TEST) +=		kunit-test.o
 
 # string-stream-test compiles built-in only.
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
new file mode 100644
index 0000000..9214c49
--- /dev/null
+++ b/lib/kunit/debugfs.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ *    Author: Alan Maguire <alan.maguire@oracle.com>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/module.h>
+
+#include <kunit/test.h>
+
+#include "string-stream.h"
+
+#define KUNIT_DEBUGFS_ROOT             "kunit"
+#define KUNIT_DEBUGFS_RESULTS          "results"
+
+/*
+ * Create a debugfs representation of test suites:
+ *
+ * Path						Semantics
+ * /sys/kernel/debug/kunit/<testsuite>/results	Show results of last run for
+ *						testsuite
+ *
+ */
+
+static struct dentry *debugfs_rootdir;
+
+void kunit_debugfs_cleanup(void)
+{
+	debugfs_remove_recursive(debugfs_rootdir);
+}
+
+void kunit_debugfs_init(void)
+{
+	if (!debugfs_rootdir)
+		debugfs_rootdir = debugfs_create_dir(KUNIT_DEBUGFS_ROOT, NULL);
+}
+
+static void debugfs_print_result(struct seq_file *seq,
+				 struct kunit_suite *suite,
+				 struct kunit_case *test_case)
+{
+	if (!test_case || !test_case->log)
+		return;
+
+	seq_printf(seq, "%s", test_case->log);
+}
+
+/*
+ * /sys/kernel/debug/kunit/<testsuite>/results shows all results for testsuite.
+ */
+static int debugfs_print_results(struct seq_file *seq, void *v)
+{
+	struct kunit_suite *suite = (struct kunit_suite *)seq->private;
+	bool success = kunit_suite_has_succeeded(suite);
+	struct kunit_case *test_case;
+
+	if (!suite || !suite->log)
+		return 0;
+
+	seq_printf(seq, "%s", suite->log);
+
+	kunit_suite_for_each_test_case(suite, test_case)
+		debugfs_print_result(seq, suite, test_case);
+
+	seq_printf(seq, "%s %d - %s\n",
+		   kunit_status_to_string(success), 1, suite->name);
+	return 0;
+}
+
+static int debugfs_release(struct inode *inode, struct file *file)
+{
+	return single_release(inode, file);
+}
+
+static int debugfs_results_open(struct inode *inode, struct file *file)
+{
+	struct kunit_suite *suite;
+
+	suite = (struct kunit_suite *)inode->i_private;
+
+	return single_open(file, debugfs_print_results, suite);
+}
+
+static const struct file_operations debugfs_results_fops = {
+	.open = debugfs_results_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = debugfs_release,
+};
+
+void kunit_debugfs_create_suite(struct kunit_suite *suite)
+{
+	struct kunit_case *test_case;
+
+	/* Allocate logs before creating debugfs representation. */
+	suite->log = kzalloc(KUNIT_LOG_SIZE, GFP_KERNEL);
+	kunit_suite_for_each_test_case(suite, test_case)
+		test_case->log = kzalloc(KUNIT_LOG_SIZE, GFP_KERNEL);
+
+	suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir);
+
+	debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444,
+			    suite->debugfs,
+			    suite, &debugfs_results_fops);
+}
+
+void kunit_debugfs_destroy_suite(struct kunit_suite *suite)
+{
+	struct kunit_case *test_case;
+
+	debugfs_remove_recursive(suite->debugfs);
+	kfree(suite->log);
+	kunit_suite_for_each_test_case(suite, test_case)
+		kfree(test_case->log);
+}
diff --git a/lib/kunit/debugfs.h b/lib/kunit/debugfs.h
new file mode 100644
index 0000000..dcc7d75
--- /dev/null
+++ b/lib/kunit/debugfs.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020, Oracle and/or its affiliates.
+ */
+
+#ifndef _KUNIT_DEBUGFS_H
+#define _KUNIT_DEBUGFS_H
+
+#include <kunit/test.h>
+
+#ifdef CONFIG_KUNIT_DEBUGFS
+
+void kunit_debugfs_create_suite(struct kunit_suite *suite);
+void kunit_debugfs_destroy_suite(struct kunit_suite *suite);
+void kunit_debugfs_init(void);
+void kunit_debugfs_cleanup(void);
+
+#else
+
+static inline void kunit_debugfs_create_suite(struct kunit_suite *suite) { }
+
+static inline void kunit_debugfs_destroy_suite(struct kunit_suite *suite) { }
+
+static inline void kunit_debugfs_init(void) { }
+
+static inline void kunit_debugfs_cleanup(void) { }
+
+#endif /* CONFIG_KUNIT_DEBUGFS */
+
+#endif /* _KUNIT_DEBUGFS_H */
diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index ccb8d2e..aceb5bf 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -134,7 +134,7 @@ 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_init_test(&ctx->test, "testing_test_init_test", NULL);
 
 	KUNIT_EXPECT_TRUE(test, list_empty(&ctx->test.resources));
 }
@@ -301,7 +301,7 @@ static int kunit_resource_test_init(struct kunit *test)
 
 	test->priv = ctx;
 
-	kunit_init_test(&ctx->test, "test_test_context");
+	kunit_init_test(&ctx->test, "test_test_context", NULL);
 
 	return 0;
 }
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 9242f93..c0f65b9 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -10,6 +10,7 @@
 #include <linux/kernel.h>
 #include <linux/sched/debug.h>
 
+#include "debugfs.h"
 #include "string-stream.h"
 #include "try-catch-impl.h"
 
@@ -28,73 +29,91 @@ static void kunit_print_tap_version(void)
 	}
 }
 
-static size_t kunit_test_cases_len(struct kunit_case *test_cases)
+size_t kunit_suite_num_test_cases(struct kunit_suite *suite)
 {
 	struct kunit_case *test_case;
 	size_t len = 0;
 
-	for (test_case = test_cases; test_case->run_case; test_case++)
+	kunit_suite_for_each_test_case(suite, test_case)
 		len++;
 
 	return len;
 }
+EXPORT_SYMBOL_GPL(kunit_suite_num_test_cases);
 
 static void kunit_print_subtest_start(struct kunit_suite *suite)
 {
 	kunit_print_tap_version();
-	pr_info("\t# Subtest: %s\n", suite->name);
-	pr_info("\t1..%zd\n", kunit_test_cases_len(suite->test_cases));
+	kunit_log(KERN_INFO, suite, "# Subtest: %s", suite->name);
+	kunit_log(KERN_INFO, suite, "1..%zd",
+		  kunit_suite_num_test_cases(suite));
 }
 
-static void kunit_print_ok_not_ok(bool should_indent,
+static void kunit_print_ok_not_ok(void *test_or_suite,
+				  bool is_test,
 				  bool is_ok,
 				  size_t test_number,
 				  const char *description)
 {
-	const char *indent, *ok_not_ok;
+	struct kunit_suite *suite = is_test ? NULL : test_or_suite;
+	struct kunit *test = is_test ? test_or_suite : NULL;
 
-	if (should_indent)
-		indent = "\t";
-	else
-		indent = "";
-
-	if (is_ok)
-		ok_not_ok = "ok";
+	/*
+	 * We do not log the test suite results as doing so would
+	 * mean debugfs display would consist of the test suite
+	 * description and status prior to individual test results.
+	 * Hence directly printk the suite status, and we will
+	 * separately seq_printf() the suite status for the debugfs
+	 * representation.
+	 */
+	if (suite)
+		pr_info("%s %zd - %s",
+			kunit_status_to_string(is_ok),
+			test_number, description);
 	else
-		ok_not_ok = "not ok";
-
-	pr_info("%s%s %zd - %s\n", indent, ok_not_ok, test_number, description);
+		kunit_log(KERN_INFO, test, "\t%s %zd - %s",
+			  kunit_status_to_string(is_ok),
+			  test_number, description);
 }
 
-static bool kunit_suite_has_succeeded(struct kunit_suite *suite)
+bool kunit_suite_has_succeeded(struct kunit_suite *suite)
 {
 	const struct kunit_case *test_case;
 
-	for (test_case = suite->test_cases; test_case->run_case; test_case++)
+	kunit_suite_for_each_test_case(suite, test_case) {
 		if (!test_case->success)
 			return false;
+	}
 
 	return true;
 }
+EXPORT_SYMBOL_GPL(kunit_suite_has_succeeded);
 
 static void kunit_print_subtest_end(struct kunit_suite *suite)
 {
 	static size_t kunit_suite_counter = 1;
 
-	kunit_print_ok_not_ok(false,
+	kunit_print_ok_not_ok((void *)suite, false,
 			      kunit_suite_has_succeeded(suite),
 			      kunit_suite_counter++,
 			      suite->name);
 }
 
-static void kunit_print_test_case_ok_not_ok(struct kunit_case *test_case,
-					    size_t test_number)
+unsigned int kunit_test_case_num(struct kunit_suite *suite,
+				 struct kunit_case *test_case)
 {
-	kunit_print_ok_not_ok(true,
-			      test_case->success,
-			      test_number,
-			      test_case->name);
+	struct kunit_case *tc;
+	unsigned int i = 1;
+
+	kunit_suite_for_each_test_case(suite, tc) {
+		if (tc == test_case)
+			return i;
+		i++;
+	}
+
+	return 0;
 }
+EXPORT_SYMBOL_GPL(kunit_test_case_num);
 
 static void kunit_print_string_stream(struct kunit *test,
 				      struct string_stream *stream)
@@ -102,6 +121,9 @@ static void kunit_print_string_stream(struct kunit *test,
 	struct string_stream_fragment *fragment;
 	char *buf;
 
+	if (string_stream_is_empty(stream))
+		return;
+
 	buf = string_stream_get_string(stream);
 	if (!buf) {
 		kunit_err(test,
@@ -175,11 +197,14 @@ void kunit_do_assertion(struct kunit *test,
 }
 EXPORT_SYMBOL_GPL(kunit_do_assertion);
 
-void kunit_init_test(struct kunit *test, const char *name)
+void kunit_init_test(struct kunit *test, const char *name, char *log)
 {
 	spin_lock_init(&test->lock);
 	INIT_LIST_HEAD(&test->resources);
 	test->name = name;
+	test->log = log;
+	if (test->log)
+		test->log[0] = '\0';
 	test->success = true;
 }
 EXPORT_SYMBOL_GPL(kunit_init_test);
@@ -290,7 +315,7 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite,
 	struct kunit_try_catch *try_catch;
 	struct kunit test;
 
-	kunit_init_test(&test, test_case->name);
+	kunit_init_test(&test, test_case->name, test_case->log);
 	try_catch = &test.try_catch;
 
 	kunit_try_catch_init(try_catch,
@@ -303,19 +328,20 @@ static void kunit_run_case_catch_errors(struct kunit_suite *suite,
 	kunit_try_catch_run(try_catch, &context);
 
 	test_case->success = test.success;
+
+	kunit_print_ok_not_ok(&test, true, test_case->success,
+			      kunit_test_case_num(suite, test_case),
+			      test_case->name);
 }
 
 int kunit_run_tests(struct kunit_suite *suite)
 {
 	struct kunit_case *test_case;
-	size_t test_case_count = 1;
 
 	kunit_print_subtest_start(suite);
 
-	for (test_case = suite->test_cases; test_case->run_case; test_case++) {
+	kunit_suite_for_each_test_case(suite, test_case)
 		kunit_run_case_catch_errors(suite, test_case);
-		kunit_print_test_case_ok_not_ok(test_case, test_case_count++);
-	}
 
 	kunit_print_subtest_end(suite);
 
@@ -323,6 +349,37 @@ int kunit_run_tests(struct kunit_suite *suite)
 }
 EXPORT_SYMBOL_GPL(kunit_run_tests);
 
+static void kunit_init_suite(struct kunit_suite *suite)
+{
+	kunit_debugfs_create_suite(suite);
+}
+
+int __kunit_test_suites_init(struct kunit_suite **suites)
+{
+	unsigned int i;
+
+	for (i = 0; suites[i] != NULL; i++) {
+		kunit_init_suite(suites[i]);
+		kunit_run_tests(suites[i]);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__kunit_test_suites_init);
+
+static void kunit_exit_suite(struct kunit_suite *suite)
+{
+	kunit_debugfs_destroy_suite(suite);
+}
+
+void __kunit_test_suites_exit(struct kunit_suite **suites)
+{
+	unsigned int i;
+
+	for (i = 0; suites[i] != NULL; i++)
+		kunit_exit_suite(suites[i]);
+}
+EXPORT_SYMBOL_GPL(__kunit_test_suites_exit);
+
 struct kunit_resource *kunit_alloc_and_get_resource(struct kunit *test,
 						    kunit_resource_init_t init,
 						    kunit_resource_free_t free,
@@ -489,12 +546,15 @@ void kunit_cleanup(struct kunit *test)
 
 static int __init kunit_init(void)
 {
+	kunit_debugfs_init();
+
 	return 0;
 }
 late_initcall(kunit_init);
 
 static void __exit kunit_exit(void)
 {
+	kunit_debugfs_cleanup();
 }
 module_exit(kunit_exit);
 
-- 
1.8.3.1

[PATCH v4 kunit-next 2/3] kunit: add log test

[Alan Maguire]

the logging test ensures multiple strings logged appear in the
log string associated with the test when CONFIG_KUNIT_DEBUGFS is
enabled.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
---
 lib/kunit/kunit-test.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index aceb5bf..0789060 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -329,6 +329,31 @@ static void kunit_resource_test_exit(struct kunit *test)
 	.exit = kunit_resource_test_exit,
 	.test_cases = kunit_resource_test_cases,
 };
-kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite);
+
+static void kunit_log_test(struct kunit *test)
+{
+	kunit_log(KERN_INFO, test, "put this in log.");
+	kunit_log(KERN_INFO, test, "this too.");
+
+#ifdef CONFIG_KUNIT_DEBUGFS
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
+				     strstr(test->log, "put this in log."));
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
+				     strstr(test->log, "this too."));
+#endif
+}
+
+static struct kunit_case kunit_log_test_cases[] = {
+	KUNIT_CASE(kunit_log_test),
+	{}
+};
+
+static struct kunit_suite kunit_log_test_suite = {
+	.name = "kunit-log-test",
+	.test_cases = kunit_log_test_cases,
+};
+
+kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite,
+		  &kunit_log_test_suite);
 
 MODULE_LICENSE("GPL v2");
-- 
1.8.3.1

[PATCH v4 kunit-next 3/3] kunit: update documentation to describe debugfs representation

[Alan Maguire]

Documentation should describe debugfs layout and semantics.

Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
---
 Documentation/dev-tools/kunit/usage.rst | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index 7cd56a1..816fff4 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -590,3 +590,16 @@ able to run one test case per invocation.
 
 .. TODO(brendanhiggins@google.com): Add an actual example of an architecture
    dependent KUnit test.
+
+KUnit debugfs representation
+============================
+When kunit test suites are initialized, they create an associated directory
+in /sys/kernel/debug/kunit/<test-suite>.  The directory contains one file
+
+- results: "cat results" displays results of each test case and the results
+  of the entire suite for the last test run.
+
+The debugfs representation is primarily of use when kunit test suites are
+run in a native environment, either as modules or builtin.  Having a way
+to display results like this is valuable as otherwise results can be
+intermixed with other events in dmesg output.
-- 
1.8.3.1

Re: [PATCH v4 kunit-next 2/3] kunit: add log test

[Brendan Higgins]

On Mon, Feb 17, 2020 at 6:28 AM Alan Maguire <alan.maguire@oracle.com> wrote:
>
> the logging test ensures multiple strings logged appear in the
> log string associated with the test when CONFIG_KUNIT_DEBUGFS is
> enabled.
>
> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>

Reviewed-by: Brendan Higgins <brendanhiggins@google.com>

One minor comment below.

> ---
>  lib/kunit/kunit-test.c | 27 ++++++++++++++++++++++++++-
>  1 file changed, 26 insertions(+), 1 deletion(-)
>
> diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
> index aceb5bf..0789060 100644
> --- a/lib/kunit/kunit-test.c
> +++ b/lib/kunit/kunit-test.c
> @@ -329,6 +329,31 @@ static void kunit_resource_test_exit(struct kunit *test)
>         .exit = kunit_resource_test_exit,
>         .test_cases = kunit_resource_test_cases,
>  };
> -kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite);
> +
> +static void kunit_log_test(struct kunit *test)
> +{
> +       kunit_log(KERN_INFO, test, "put this in log.");
> +       kunit_log(KERN_INFO, test, "this too.");
> +
> +#ifdef CONFIG_KUNIT_DEBUGFS
> +       KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
> +                                    strstr(test->log, "put this in log."));
> +       KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
> +                                    strstr(test->log, "this too."));
> +#endif
> +}

Would you mind adding some expectations against the suite log? It
might be good for the sake of completeness.

> +
> +static struct kunit_case kunit_log_test_cases[] = {
> +       KUNIT_CASE(kunit_log_test),
> +       {}
> +};
> +
> +static struct kunit_suite kunit_log_test_suite = {
> +       .name = "kunit-log-test",
> +       .test_cases = kunit_log_test_cases,
> +};
> +
> +kunit_test_suites(&kunit_try_catch_test_suite, &kunit_resource_test_suite,
> +                 &kunit_log_test_suite);
>
>  MODULE_LICENSE("GPL v2");
> --
> 1.8.3.1
>