[PATCH v2 1/4] kunit: rename print_subtest_{start,end} for clarity (s/subtest/suite)

[PATCH v2 1/4] kunit: rename print_subtest_{start,end} for clarity (s/subtest/suite)

[Daniel Latypov]

These names sound more general than they are.

The _end() function increments a `static int kunit_suite_counter`, so it
can only safely be called on suites, aka top-level subtests.
It would need to have a separate counter for each level of subtest to be
generic enough.

So rename it to make it clear it's only appropriate for suites.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
---
v1 -> v2: no change (see patch 2 and 4)
---
 lib/kunit/test.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 0f66c13d126e..64ee6a9d8003 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -134,7 +134,7 @@ size_t kunit_suite_num_test_cases(struct kunit_suite *suite)
 }
 EXPORT_SYMBOL_GPL(kunit_suite_num_test_cases);
 
-static void kunit_print_subtest_start(struct kunit_suite *suite)
+static void kunit_print_suite_start(struct kunit_suite *suite)
 {
 	kunit_log(KERN_INFO, suite, KUNIT_SUBTEST_INDENT "# Subtest: %s",
 		  suite->name);
@@ -192,7 +192,7 @@ EXPORT_SYMBOL_GPL(kunit_suite_has_succeeded);
 
 static size_t kunit_suite_counter = 1;
 
-static void kunit_print_subtest_end(struct kunit_suite *suite)
+static void kunit_print_suite_end(struct kunit_suite *suite)
 {
 	kunit_print_ok_not_ok((void *)suite, false,
 			      kunit_suite_has_succeeded(suite),
@@ -498,7 +498,7 @@ int kunit_run_tests(struct kunit_suite *suite)
 	struct kunit_result_stats suite_stats = { 0 };
 	struct kunit_result_stats total_stats = { 0 };
 
-	kunit_print_subtest_start(suite);
+	kunit_print_suite_start(suite);
 
 	kunit_suite_for_each_test_case(suite, test_case) {
 		struct kunit test = { .param_value = NULL, .param_index = 0 };
@@ -552,7 +552,7 @@ int kunit_run_tests(struct kunit_suite *suite)
 	}
 
 	kunit_print_suite_stats(suite, suite_stats, total_stats);
-	kunit_print_subtest_end(suite);
+	kunit_print_suite_end(suite);
 
 	return 0;
 }

base-commit: 59729170afcd4900e08997a482467ffda8d88c7f
-- 
2.36.0.464.gb9c8b46e94-goog

[PATCH v2 2/4] kunit: add ability to specify suite-level init and exit functions

[Daniel Latypov]

KUnit has support for setup/cleanup logic for each test case in a suite.
But it lacks the ability to specify setup/cleanup for the entire suite
itself.

This can be used to do setup that is too expensive or cumbersome to do
for each test.
Or it can be used to do simpler things like log debug information after
the suite completes.
It's a fairly common feature, so the lack of it is noticeable.

Some examples in other frameworks and languages:
* https://docs.python.org/3/library/unittest.html#setupclass-and-teardownclass
* https://google.github.io/googletest/reference/testing.html#Test::SetUpTestSuite

Meta:
This is very similar to this patch here: https://lore.kernel.org/linux-kselftest/20210805043503.20252-3-bvanassche@acm.org/
The changes from that patch:
* pass in `struct kunit *` so users can do stuff like
  `kunit_info(suite, "debug message")`
* makes sure the init failure is bubbled up as a failure
* updates kunit-example-test.c to use a suite init
* Updates kunit/usage.rst to mention the new support
* some minor cosmetic things
  * use `suite_{init,exit}` instead of `{init/exit}_suite`
  * make suite init error message more consistent w/ test init
  * etc.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
---
v1 -> v2: add suite_init_err to struct kunit_suite so
kunit_suite_has_succeeded() still works for CONFIG_KUNIT_DEBUGFS=y.
---
 Documentation/dev-tools/kunit/usage.rst | 19 +++++++++++--------
 include/kunit/test.h                    |  5 +++++
 lib/kunit/kunit-example-test.c          | 14 ++++++++++++++
 lib/kunit/test.c                        | 17 +++++++++++++++++
 4 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/Documentation/dev-tools/kunit/usage.rst b/Documentation/dev-tools/kunit/usage.rst
index 1c83e7d60a8a..d62a04255c2e 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -125,8 +125,8 @@ We need many test cases covering all the unit's behaviors. It is common to have
 many similar tests. In order to reduce duplication in these closely related
 tests, most unit testing frameworks (including KUnit) provide the concept of a
 *test suite*. A test suite is a collection of test cases for a unit of code
-with a setup function that gets invoked before every test case and then a tear
-down function that gets invoked after every test case completes. For example:
+with optional setup and teardown functions that run before/after the whole
+suite and/or every test case. For example:
 
 .. code-block:: c
 
@@ -141,16 +141,19 @@ down function that gets invoked after every test case completes. For example:
 		.name = "example",
 		.init = example_test_init,
 		.exit = example_test_exit,
+		.suite_init = example_suite_init,
+		.suite_exit = example_suite_exit,
 		.test_cases = example_test_cases,
 	};
 	kunit_test_suite(example_test_suite);
 
-In the above example, the test suite ``example_test_suite`` would run the test
-cases ``example_test_foo``, ``example_test_bar``, and ``example_test_baz``. Each
-would have ``example_test_init`` called immediately before it and
-``example_test_exit`` called immediately after it.
-``kunit_test_suite(example_test_suite)`` registers the test suite with the
-KUnit test framework.
+In the above example, the test suite ``example_test_suite`` would first run
+``example_suite_init``, then 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 ``example_test_exit``
+called immediately after it. Finally, ``example_suite_exit`` would be called
+after everything else. ``kunit_test_suite(example_test_suite)`` registers the
+test suite with the KUnit test framework.
 
 .. note::
    A test case will only run if it is associated with a test suite.
diff --git a/include/kunit/test.h b/include/kunit/test.h
index 97cd76461886..604eb5263b6b 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -153,6 +153,8 @@ static inline char *kunit_status_to_ok_not_ok(enum kunit_status status)
  * struct kunit_suite - describes a related collection of &struct kunit_case
  *
  * @name:	the name of the test. Purely informational.
+ * @suite_init:	called once per test suite before the test cases.
+ * @suite_exit:	called once per test suite after all test cases.
  * @init:	called before every test case.
  * @exit:	called after every test case.
  * @test_cases:	a null terminated array of test cases.
@@ -167,6 +169,8 @@ static inline char *kunit_status_to_ok_not_ok(enum kunit_status status)
  */
 struct kunit_suite {
 	const char name[256];
+	int (*suite_init)(struct kunit_suite *suite);
+	void (*suite_exit)(struct kunit_suite *suite);
 	int (*init)(struct kunit *test);
 	void (*exit)(struct kunit *test);
 	struct kunit_case *test_cases;
@@ -175,6 +179,7 @@ struct kunit_suite {
 	char status_comment[KUNIT_STATUS_COMMENT_SIZE];
 	struct dentry *debugfs;
 	char *log;
+	int suite_init_err;
 };
 
 /**
diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
index 91b1df7f59ed..f8fe582c9e36 100644
--- a/lib/kunit/kunit-example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -40,6 +40,17 @@ static int example_test_init(struct kunit *test)
 	return 0;
 }
 
+/*
+ * This is run once before all test cases in the suite.
+ * See the comment on example_test_suite for more information.
+ */
+static int example_test_init_suite(struct kunit_suite *suite)
+{
+	kunit_info(suite, "initializing suite\n");
+
+	return 0;
+}
+
 /*
  * This test should always be skipped.
  */
@@ -142,17 +153,20 @@ static struct kunit_case example_test_cases[] = {
  * may be specified which runs after every test case and can be used to for
  * cleanup. For clarity, running tests in a test suite would behave as follows:
  *
+ * suite.suite_init(suite);
  * suite.init(test);
  * suite.test_case[0](test);
  * suite.exit(test);
  * suite.init(test);
  * suite.test_case[1](test);
  * suite.exit(test);
+ * suite.suite_exit(suite);
  * ...;
  */
 static struct kunit_suite example_test_suite = {
 	.name = "example",
 	.init = example_test_init,
+	.suite_init = example_test_init_suite,
 	.test_cases = example_test_cases,
 };
 
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 64ee6a9d8003..65c56bd0545d 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -179,6 +179,9 @@ enum kunit_status kunit_suite_has_succeeded(struct kunit_suite *suite)
 	const struct kunit_case *test_case;
 	enum kunit_status status = KUNIT_SKIPPED;
 
+	if (suite->suite_init_err)
+		return KUNIT_FAILURE;
+
 	kunit_suite_for_each_test_case(suite, test_case) {
 		if (test_case->status == KUNIT_FAILURE)
 			return KUNIT_FAILURE;
@@ -498,6 +501,15 @@ int kunit_run_tests(struct kunit_suite *suite)
 	struct kunit_result_stats suite_stats = { 0 };
 	struct kunit_result_stats total_stats = { 0 };
 
+	if (suite->suite_init) {
+		suite->suite_init_err = suite->suite_init(suite);
+		if (suite->suite_init_err) {
+			kunit_err(suite, KUNIT_SUBTEST_INDENT
+				  "# failed to initialize (%d)", suite->suite_init_err);
+			goto suite_end;
+		}
+	}
+
 	kunit_print_suite_start(suite);
 
 	kunit_suite_for_each_test_case(suite, test_case) {
@@ -551,7 +563,11 @@ int kunit_run_tests(struct kunit_suite *suite)
 		kunit_accumulate_stats(&total_stats, param_stats);
 	}
 
+	if (suite->suite_exit)
+		suite->suite_exit(suite);
+
 	kunit_print_suite_stats(suite, suite_stats, total_stats);
+suite_end:
 	kunit_print_suite_end(suite);
 
 	return 0;
@@ -562,6 +578,7 @@ static void kunit_init_suite(struct kunit_suite *suite)
 {
 	kunit_debugfs_create_suite(suite);
 	suite->status_comment[0] = '\0';
+	suite->suite_init_err = 0;
 }
 
 int __kunit_test_suites_init(struct kunit_suite * const * const suites)
-- 
2.36.0.464.gb9c8b46e94-goog

[PATCH v2 3/4] kfence: test: use new suite_{init/exit} support, add .kunitconfig

[Daniel Latypov]

Currently, the kfence test suite could not run via "normal" means since
KUnit didn't support per-suite setup/teardown. So it manually called
internal kunit functions to run itself.
This has some downsides, like missing TAP headers => can't use kunit.py
to run or even parse the test results (w/o tweaks).

Use the newly added support and convert it over, adding a .kunitconfig
so it's even easier to run from kunit.py.

People can now run the test via
$ ./tools/testing/kunit/kunit.py run --kunitconfig=mm/kfence --arch=x86_64
...
[11:02:32] Testing complete. Passed: 23, Failed: 0, Crashed: 0, Skipped: 2, Errors: 0
[11:02:32] Elapsed time: 43.562s total, 0.003s configuring, 9.268s building, 34.281s running

Cc: kasan-dev@googlegroups.com
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: Marco Elver <elver@google.com>
---
v1 -> v2: no change (see patch 2 and 4)
---
 mm/kfence/.kunitconfig  |  6 ++++++
 mm/kfence/kfence_test.c | 31 +++++++++++++------------------
 2 files changed, 19 insertions(+), 18 deletions(-)
 create mode 100644 mm/kfence/.kunitconfig

diff --git a/mm/kfence/.kunitconfig b/mm/kfence/.kunitconfig
new file mode 100644
index 000000000000..f3d65e939bfa
--- /dev/null
+++ b/mm/kfence/.kunitconfig
@@ -0,0 +1,6 @@
+CONFIG_KUNIT=y
+CONFIG_KFENCE=y
+CONFIG_KFENCE_KUNIT_TEST=y
+
+# Additional dependencies.
+CONFIG_FTRACE=y
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index 1b50f70a4c0f..96206a4ee9ab 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -826,14 +826,6 @@ static void test_exit(struct kunit *test)
 	test_cache_destroy();
 }
 
-static struct kunit_suite kfence_test_suite = {
-	.name = "kfence",
-	.test_cases = kfence_test_cases,
-	.init = test_init,
-	.exit = test_exit,
-};
-static struct kunit_suite *kfence_test_suites[] = { &kfence_test_suite, NULL };
-
 static void register_tracepoints(struct tracepoint *tp, void *ignore)
 {
 	check_trace_callback_type_console(probe_console);
@@ -847,11 +839,7 @@ static void unregister_tracepoints(struct tracepoint *tp, void *ignore)
 		tracepoint_probe_unregister(tp, probe_console, NULL);
 }
 
-/*
- * We only want to do tracepoints setup and teardown once, therefore we have to
- * customize the init and exit functions and cannot rely on kunit_test_suite().
- */
-static int __init kfence_test_init(void)
+static int kfence_suite_init(struct kunit_suite *suite)
 {
 	/*
 	 * Because we want to be able to build the test as a module, we need to
@@ -859,18 +847,25 @@ static int __init kfence_test_init(void)
 	 * won't work here.
 	 */
 	for_each_kernel_tracepoint(register_tracepoints, NULL);
-	return __kunit_test_suites_init(kfence_test_suites);
+	return 0;
 }
 
-static void kfence_test_exit(void)
+static void kfence_suite_exit(struct kunit_suite *suite)
 {
-	__kunit_test_suites_exit(kfence_test_suites);
 	for_each_kernel_tracepoint(unregister_tracepoints, NULL);
 	tracepoint_synchronize_unregister();
 }
 
-late_initcall_sync(kfence_test_init);
-module_exit(kfence_test_exit);
+static struct kunit_suite kfence_test_suite = {
+	.name = "kfence",
+	.test_cases = kfence_test_cases,
+	.init = test_init,
+	.exit = test_exit,
+	.suite_init = kfence_suite_init,
+	.suite_exit = kfence_suite_exit,
+};
+
+kunit_test_suites(&kfence_test_suite);
 
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Alexander Potapenko <glider@google.com>, Marco Elver <elver@google.com>");
-- 
2.36.0.464.gb9c8b46e94-goog

[PATCH v2 4/4] kunit: fix debugfs code to use enum kunit_status, not bool

[Daniel Latypov]

Commit 6d2426b2f258 ("kunit: Support skipped tests") switched to using
`enum kunit_status` to track the result of running a test/suite since we
now have more than just pass/fail.

This callsite wasn't updated, silently converting to enum to a bool and
then back.

Fixes: 6d2426b2f258 ("kunit: Support skipped tests")
Signed-off-by: Daniel Latypov <dlatypov@google.com>
---
v1 -> v2: added this patch.
---
 lib/kunit/debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index b71db0abc12b..1048ef1b8d6e 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -52,7 +52,7 @@ static void debugfs_print_result(struct seq_file *seq,
 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);
+	enum kunit_status success = kunit_suite_has_succeeded(suite);
 	struct kunit_case *test_case;
 
 	if (!suite || !suite->log)
-- 
2.36.0.464.gb9c8b46e94-goog

Re: [PATCH v2 1/4] kunit: rename print_subtest_{start,end} for clarity (s/subtest/suite)

[Brendan Higgins]

On Fri, Apr 29, 2022 at 2:13 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> These names sound more general than they are.
>
> The _end() function increments a `static int kunit_suite_counter`, so it
> can only safely be called on suites, aka top-level subtests.
> It would need to have a separate counter for each level of subtest to be
> generic enough.
>
> So rename it to make it clear it's only appropriate for suites.
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> Reviewed-by: David Gow <davidgow@google.com>

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

Re: [PATCH v2 2/4] kunit: add ability to specify suite-level init and exit functions

[Brendan Higgins]

On Fri, Apr 29, 2022 at 2:13 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> KUnit has support for setup/cleanup logic for each test case in a suite.
> But it lacks the ability to specify setup/cleanup for the entire suite
> itself.
>
> This can be used to do setup that is too expensive or cumbersome to do
> for each test.
> Or it can be used to do simpler things like log debug information after
> the suite completes.
> It's a fairly common feature, so the lack of it is noticeable.
>
> Some examples in other frameworks and languages:
> * https://docs.python.org/3/library/unittest.html#setupclass-and-teardownclass
> * https://google.github.io/googletest/reference/testing.html#Test::SetUpTestSuite
>
> Meta:
> This is very similar to this patch here: https://lore.kernel.org/linux-kselftest/20210805043503.20252-3-bvanassche@acm.org/
> The changes from that patch:
> * pass in `struct kunit *` so users can do stuff like
>   `kunit_info(suite, "debug message")`
> * makes sure the init failure is bubbled up as a failure
> * updates kunit-example-test.c to use a suite init
> * Updates kunit/usage.rst to mention the new support
> * some minor cosmetic things
>   * use `suite_{init,exit}` instead of `{init/exit}_suite`
>   * make suite init error message more consistent w/ test init
>   * etc.
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> Reviewed-by: David Gow <davidgow@google.com>

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

Re: [PATCH v2 3/4] kfence: test: use new suite_{init/exit} support, add .kunitconfig

[Brendan Higgins]

On Fri, Apr 29, 2022 at 2:13 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> Currently, the kfence test suite could not run via "normal" means since
> KUnit didn't support per-suite setup/teardown. So it manually called
> internal kunit functions to run itself.
> This has some downsides, like missing TAP headers => can't use kunit.py
> to run or even parse the test results (w/o tweaks).
>
> Use the newly added support and convert it over, adding a .kunitconfig
> so it's even easier to run from kunit.py.
>
> People can now run the test via
> $ ./tools/testing/kunit/kunit.py run --kunitconfig=mm/kfence --arch=x86_64
> ...
> [11:02:32] Testing complete. Passed: 23, Failed: 0, Crashed: 0, Skipped: 2, Errors: 0
> [11:02:32] Elapsed time: 43.562s total, 0.003s configuring, 9.268s building, 34.281s running
>
> Cc: kasan-dev@googlegroups.com
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> Tested-by: David Gow <davidgow@google.com>
> Reviewed-by: Marco Elver <elver@google.com>

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

Re: [PATCH v2 4/4] kunit: fix debugfs code to use enum kunit_status, not bool

[Brendan Higgins]

On Fri, Apr 29, 2022 at 2:13 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> Commit 6d2426b2f258 ("kunit: Support skipped tests") switched to using
> `enum kunit_status` to track the result of running a test/suite since we
> now have more than just pass/fail.
>
> This callsite wasn't updated, silently converting to enum to a bool and
> then back.
>
> Fixes: 6d2426b2f258 ("kunit: Support skipped tests")
> Signed-off-by: Daniel Latypov <dlatypov@google.com>

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