[PATCH v3 1/2] kunit: drop assumption in kunit-log-test about current suite

[PATCH v3 1/2] kunit: drop assumption in kunit-log-test about current suite

[Daniel Latypov]

This test assumes that the declared kunit_suite object is the exact one
which is being executed, which KUnit will not guarantee [1].

Specifically, `suite->log` is not initialized until a suite object is
executed. So if KUnit makes a copy of the suite and runs that instead,
this test dereferences an invalid pointer and (hopefully) segfaults.

N.B. since we no longer assume this, we can no longer verify that
`suite->log` is *not* allocated during normal execution.

An alternative to this patch that would allow us to test that would
require exposing an API for the current test to get its current suite.
Exposing that for one internal kunit test seems like overkill, and
grants users more footguns (e.g. reusing a test case in multiple suites
and changing behavior based on the suite name, dynamically modifying the
setup/cleanup funcs, storing/reading stuff out of the suite->log, etc.).

[1] In a subsequent patch, KUnit will allow running subsets of test
cases within a suite by making a copy of the suite w/ the filtered test
list. But there are other reasons KUnit might execute a copy, e.g. if it
ever wants to support parallel execution of different suites, recovering
from errors and restarting suites

Signed-off-by: Daniel Latypov <dlatypov@google.com>
---
 lib/kunit/kunit-test.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index d69efcbed624..555601d17f79 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -415,12 +415,15 @@ static struct kunit_suite kunit_log_test_suite = {
 
 static void kunit_log_test(struct kunit *test)
 {
-	struct kunit_suite *suite = &kunit_log_test_suite;
+	struct kunit_suite suite;
+
+	suite.log = kunit_kzalloc(test, KUNIT_LOG_SIZE, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, suite.log);
 
 	kunit_log(KERN_INFO, test, "put this in log.");
 	kunit_log(KERN_INFO, test, "this too.");
-	kunit_log(KERN_INFO, suite, "add to suite log.");
-	kunit_log(KERN_INFO, suite, "along with this.");
+	kunit_log(KERN_INFO, &suite, "add to suite log.");
+	kunit_log(KERN_INFO, &suite, "along with this.");
 
 #ifdef CONFIG_KUNIT_DEBUGFS
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
@@ -428,12 +431,11 @@ static void kunit_log_test(struct kunit *test)
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
 				     strstr(test->log, "this too."));
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
-				     strstr(suite->log, "add to suite log."));
+				     strstr(suite.log, "add to suite log."));
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
-				     strstr(suite->log, "along with this."));
+				     strstr(suite.log, "along with this."));
 #else
 	KUNIT_EXPECT_PTR_EQ(test, test->log, (char *)NULL);
-	KUNIT_EXPECT_PTR_EQ(test, suite->log, (char *)NULL);
 #endif
 }
 

base-commit: 9c849ce86e0fa93a218614eac562ace44053d7ce
-- 
2.33.0.259.gc128427fd7-goog

[PATCH v3 2/2] kunit: tool: allow filtering test cases via glob

[Daniel Latypov]

Commit 1d71307a6f94 ("kunit: add unit test for filtering suites by
names") introduced the ability to filter which suites we run via glob.

This change extends it so we can also filter individual test cases
inside of suites as well.

This is quite useful when, e.g.
* trying to run just the tests cases you've just added or are working on
* trying to debug issues with test hermeticity

Examples:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit '*exec*.parse*'
...
============================================================
======== [PASSED] kunit_executor_test ========
[PASSED] parse_filter_test
============================================================
Testing complete. 1 tests run. 0 failed. 0 crashed.

$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit '*.no_matching_tests'
...
[ERROR] no tests run!

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
---
v1 -> v2: update Documentation/.../running_tips.rst
v2 -> v3: add missing `static` (thanks lkp bot), add prework patch to
fix kunit-log-test's assumption about the current suite.
---
 .../dev-tools/kunit/running_tips.rst          |  11 +-
 lib/kunit/executor.c                          | 107 +++++++++++++++--
 lib/kunit/executor_test.c                     | 109 +++++++++++++++---
 tools/testing/kunit/kunit.py                  |   5 +-
 4 files changed, 203 insertions(+), 29 deletions(-)

diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
index d1626d548fa5..f471bcbdabd4 100644
--- a/Documentation/dev-tools/kunit/running_tips.rst
+++ b/Documentation/dev-tools/kunit/running_tips.rst
@@ -25,8 +25,8 @@ It can be handy to create a bash function like:
 Running a subset of tests
 -------------------------
 
-``kunit.py run`` accepts an optional glob argument to filter tests. Currently
-this only matches against suite names, but this may change in the future.
+``kunit.py run`` accepts an optional glob argument to filter tests. The format
+is ``"<suite_glob>[.test_glob]"``.
 
 Say that we wanted to run the sysctl tests, we could do so via:
 
@@ -35,6 +35,13 @@ Say that we wanted to run the sysctl tests, we could do so via:
 	$ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
 	$ ./tools/testing/kunit/kunit.py run 'sysctl*'
 
+We can filter down to just the "write" tests via:
+
+.. code-block:: bash
+
+	$ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+	$ ./tools/testing/kunit/kunit.py run 'sysctl*.*write*'
+
 We're paying the cost of building more tests than we need this way, but it's
 easier than fiddling with ``.kunitconfig`` files or commenting out
 ``kunit_suite``'s.
diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index acd1de436f59..bab3ab940acc 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -17,21 +17,80 @@ extern struct kunit_suite * const * const __kunit_suites_end[];
 static char *filter_glob_param;
 module_param_named(filter_glob, filter_glob_param, charp, 0);
 MODULE_PARM_DESC(filter_glob,
-		"Filter which KUnit test suites run at boot-time, e.g. list*");
+		"Filter which KUnit test suites/tests run at boot-time, e.g. list* or list*.*del_test");
+
+/* glob_match() needs NULL terminated strings, so we need a copy of filter_glob_param. */
+struct kunit_test_filter {
+	char *suite_glob;
+	char *test_glob;
+};
+
+/* Split "suite_glob.test_glob" into two. Assumes filter_glob is not empty. */
+static void kunit_parse_filter_glob(struct kunit_test_filter *parsed,
+				    const char *filter_glob)
+{
+	const int len = strlen(filter_glob);
+	const char *period = strchr(filter_glob, '.');
+
+	if (!period) {
+		parsed->suite_glob = kmalloc(len, GFP_KERNEL);
+		parsed->test_glob = NULL;
+		strcpy(parsed->suite_glob, filter_glob);
+		return;
+	}
+
+	parsed->suite_glob = kzalloc(period - filter_glob + 1, GFP_KERNEL);
+	parsed->test_glob = kzalloc(len - (period - filter_glob) + 1, GFP_KERNEL);
+
+	strncpy(parsed->suite_glob, filter_glob, period - filter_glob);
+	strncpy(parsed->test_glob, period + 1, len - (period - filter_glob));
+}
+
+/* Create a copy of suite with only tests that match test_glob. */
+static struct kunit_suite *
+kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
+{
+	int n = 0;
+	struct kunit_case *filtered, *test_case;
+	struct kunit_suite *copy;
+
+	kunit_suite_for_each_test_case(suite, test_case) {
+		if (!test_glob || glob_match(test_glob, test_case->name))
+			++n;
+	}
+
+	if (n == 0)
+		return NULL;
+
+	/* Use memcpy to workaround copy->name being const. */
+	copy = kmalloc(sizeof(*copy), GFP_KERNEL);
+	memcpy(copy, suite, sizeof(*copy));
+
+	filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
+
+	n = 0;
+	kunit_suite_for_each_test_case(suite, test_case) {
+		if (!test_glob || glob_match(test_glob, test_case->name))
+			filtered[n++] = *test_case;
+	}
+
+	copy->test_cases = filtered;
+	return copy;
+}
 
 static char *kunit_shutdown;
 core_param(kunit_shutdown, kunit_shutdown, charp, 0644);
 
 static struct kunit_suite * const *
 kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
-			const char *filter_glob)
+		      struct kunit_test_filter *filter)
 {
 	int i, n = 0;
-	struct kunit_suite **filtered;
+	struct kunit_suite **filtered, *filtered_suite;
 
 	n = 0;
-	for (i = 0; subsuite[i] != NULL; ++i) {
-		if (glob_match(filter_glob, subsuite[i]->name))
+	for (i = 0; subsuite[i]; ++i) {
+		if (glob_match(filter->suite_glob, subsuite[i]->name))
 			++n;
 	}
 
@@ -44,8 +103,11 @@ kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
 
 	n = 0;
 	for (i = 0; subsuite[i] != NULL; ++i) {
-		if (glob_match(filter_glob, subsuite[i]->name))
-			filtered[n++] = subsuite[i];
+		if (!glob_match(filter->suite_glob, subsuite[i]->name))
+			continue;
+		filtered_suite = kunit_filter_tests(subsuite[i], filter->test_glob);
+		if (filtered_suite)
+			filtered[n++] = filtered_suite;
 	}
 	filtered[n] = NULL;
 
@@ -57,12 +119,32 @@ struct suite_set {
 	struct kunit_suite * const * const *end;
 };
 
+static void kunit_free_subsuite(struct kunit_suite * const *subsuite)
+{
+	unsigned int i;
+
+	for (i = 0; subsuite[i]; i++)
+		kfree(subsuite[i]);
+
+	kfree(subsuite);
+}
+
+static void kunit_free_suite_set(struct suite_set suite_set)
+{
+	struct kunit_suite * const * const *suites;
+
+	for (suites = suite_set.start; suites < suite_set.end; suites++)
+		kunit_free_subsuite(*suites);
+	kfree(suite_set.start);
+}
+
 static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 					    const char *filter_glob)
 {
 	int i;
 	struct kunit_suite * const **copy, * const *filtered_subsuite;
 	struct suite_set filtered;
+	struct kunit_test_filter filter;
 
 	const size_t max = suite_set->end - suite_set->start;
 
@@ -73,12 +155,17 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 		return filtered;
 	}
 
+	kunit_parse_filter_glob(&filter, filter_glob);
+
 	for (i = 0; i < max; ++i) {
-		filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], filter_glob);
+		filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], &filter);
 		if (filtered_subsuite)
 			*copy++ = filtered_subsuite;
 	}
 	filtered.end = copy;
+
+	kfree(filter.suite_glob);
+	kfree(filter.test_glob);
 	return filtered;
 }
 
@@ -126,9 +213,7 @@ int kunit_run_all_tests(void)
 		__kunit_test_suites_init(*suites);
 
 	if (filter_glob_param) { /* a copy was made of each array */
-		for (suites = suite_set.start; suites < suite_set.end; suites++)
-			kfree(*suites);
-		kfree(suite_set.start);
+		kunit_free_suite_set(suite_set);
 	}
 
 	kunit_handle_shutdown();
diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
index cdbe54b16501..ffa18f3ec0c1 100644
--- a/lib/kunit/executor_test.c
+++ b/lib/kunit/executor_test.c
@@ -9,38 +9,103 @@
 #include <kunit/test.h>
 
 static void kfree_at_end(struct kunit *test, const void *to_free);
+static void free_subsuite_at_end(struct kunit *test,
+				 struct kunit_suite *const *to_free);
 static struct kunit_suite *alloc_fake_suite(struct kunit *test,
-					    const char *suite_name);
+					    const char *suite_name,
+					    struct kunit_case *test_cases);
+
+static void dummy_test(struct kunit *test) {}
+
+struct kunit_case dummy_test_cases[] = {
+	/* .run_case is not important, just needs to be non-NULL */
+	{ .name = "test1", .run_case = dummy_test },
+	{ .name = "test2", .run_case = dummy_test },
+	{},
+};
+
+static void parse_filter_test(struct kunit *test)
+{
+	struct kunit_test_filter filter = {NULL, NULL};
+
+	kunit_parse_filter_glob(&filter, "suite");
+	KUNIT_EXPECT_STREQ(test, filter.suite_glob, "suite");
+	KUNIT_EXPECT_FALSE(test, filter.test_glob);
+	kfree(filter.suite_glob);
+	kfree(filter.test_glob);
+
+	kunit_parse_filter_glob(&filter, "suite.test");
+	KUNIT_EXPECT_STREQ(test, filter.suite_glob, "suite");
+	KUNIT_EXPECT_STREQ(test, filter.test_glob, "test");
+	kfree(filter.suite_glob);
+	kfree(filter.test_glob);
+}
 
 static void filter_subsuite_test(struct kunit *test)
 {
 	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
 	struct kunit_suite * const *filtered;
+	struct kunit_test_filter filter = {
+		.suite_glob = "suite2",
+		.test_glob = NULL,
+	};
 
-	subsuite[0] = alloc_fake_suite(test, "suite1");
-	subsuite[1] = alloc_fake_suite(test, "suite2");
+	subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+	subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
 
 	/* Want: suite1, suite2, NULL -> suite2, NULL */
-	filtered = kunit_filter_subsuite(subsuite, "suite2*");
+	filtered = kunit_filter_subsuite(subsuite, &filter);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
-	kfree_at_end(test, filtered);
+	free_subsuite_at_end(test, filtered);
 
+	/* Validate we just have suite2 */
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]);
 	KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->name, "suite2");
+	KUNIT_EXPECT_FALSE(test, filtered[1]);
+}
+
+static void filter_subsuite_test_glob_test(struct kunit *test)
+{
+	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
+	struct kunit_suite * const *filtered;
+	struct kunit_test_filter filter = {
+		.suite_glob = "suite2",
+		.test_glob = "test2",
+	};
+
+	subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+	subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
 
+	/* Want: suite1, suite2, NULL -> suite2 (just test1), NULL */
+	filtered = kunit_filter_subsuite(subsuite, &filter);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
+	free_subsuite_at_end(test, filtered);
+
+	/* Validate we just have suite2 */
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]);
+	KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->name, "suite2");
 	KUNIT_EXPECT_FALSE(test, filtered[1]);
+
+	/* Now validate we just have test2 */
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]->test_cases);
+	KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->test_cases[0].name, "test2");
+	KUNIT_EXPECT_FALSE(test, filtered[0]->test_cases[1].name);
 }
 
 static void filter_subsuite_to_empty_test(struct kunit *test)
 {
 	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
 	struct kunit_suite * const *filtered;
+	struct kunit_test_filter filter = {
+		.suite_glob = "not_found",
+		.test_glob = NULL,
+	};
 
-	subsuite[0] = alloc_fake_suite(test, "suite1");
-	subsuite[1] = alloc_fake_suite(test, "suite2");
+	subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+	subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
 
-	filtered = kunit_filter_subsuite(subsuite, "not_found");
-	kfree_at_end(test, filtered); /* just in case */
+	filtered = kunit_filter_subsuite(subsuite, &filter);
+	free_subsuite_at_end(test, filtered); /* just in case */
 
 	KUNIT_EXPECT_FALSE_MSG(test, filtered,
 			       "should be NULL to indicate no match");
@@ -52,7 +117,7 @@ static void kfree_subsuites_at_end(struct kunit *test, struct suite_set *suite_s
 
 	kfree_at_end(test, suite_set->start);
 	for (suites = suite_set->start; suites < suite_set->end; suites++)
-		kfree_at_end(test, *suites);
+		free_subsuite_at_end(test, *suites);
 }
 
 static void filter_suites_test(struct kunit *test)
@@ -74,8 +139,8 @@ static void filter_suites_test(struct kunit *test)
 	struct suite_set filtered = {.start = NULL, .end = NULL};
 
 	/* Emulate two files, each having one suite */
-	subsuites[0][0] = alloc_fake_suite(test, "suite0");
-	subsuites[1][0] = alloc_fake_suite(test, "suite1");
+	subsuites[0][0] = alloc_fake_suite(test, "suite0", dummy_test_cases);
+	subsuites[1][0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
 
 	/* Filter out suite1 */
 	filtered = kunit_filter_suites(&suite_set, "suite0");
@@ -88,7 +153,9 @@ static void filter_suites_test(struct kunit *test)
 }
 
 static struct kunit_case executor_test_cases[] = {
+	KUNIT_CASE(parse_filter_test),
 	KUNIT_CASE(filter_subsuite_test),
+	KUNIT_CASE(filter_subsuite_test_glob_test),
 	KUNIT_CASE(filter_subsuite_to_empty_test),
 	KUNIT_CASE(filter_suites_test),
 	{}
@@ -120,14 +187,30 @@ static void kfree_at_end(struct kunit *test, const void *to_free)
 				     (void *)to_free);
 }
 
+static void free_subsuite_res_free(struct kunit_resource *res)
+{
+	kunit_free_subsuite(res->data);
+}
+
+static void free_subsuite_at_end(struct kunit *test,
+				 struct kunit_suite *const *to_free)
+{
+	if (IS_ERR_OR_NULL(to_free))
+		return;
+	kunit_alloc_and_get_resource(test, NULL, free_subsuite_res_free,
+				     GFP_KERNEL, (void *)to_free);
+}
+
 static struct kunit_suite *alloc_fake_suite(struct kunit *test,
-					    const char *suite_name)
+					    const char *suite_name,
+					    struct kunit_case *test_cases)
 {
 	struct kunit_suite *suite;
 
 	/* We normally never expect to allocate suites, hence the non-const cast. */
 	suite = kunit_kzalloc(test, sizeof(*suite), GFP_KERNEL);
 	strncpy((char *)suite->name, suite_name, sizeof(suite->name) - 1);
+	suite->test_cases = test_cases;
 
 	return suite;
 }
diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
index 6276ce0c0196..558c12f34838 100755
--- a/tools/testing/kunit/kunit.py
+++ b/tools/testing/kunit/kunit.py
@@ -231,9 +231,8 @@ def add_exec_opts(parser) -> None:
 			    default=300,
 			    metavar='timeout')
 	parser.add_argument('filter_glob',
-			    help='maximum number of seconds to allow for all tests '
-			    'to run. This does not include time taken to build the '
-			    'tests.',
+			    help='Filter which KUnit test suites/tests run at '
+			    'boot-time, e.g. list* or list*.*del_test',
 			    type=str,
 			    nargs='?',
 			    default='',
-- 
2.33.0.259.gc128427fd7-goog

Re: [PATCH v3 1/2] kunit: drop assumption in kunit-log-test about current suite

[Brendan Higgins]

On Tue, Aug 31, 2021 at 10:19 AM Daniel Latypov <dlatypov@google.com> wrote:
>
> This test assumes that the declared kunit_suite object is the exact one
> which is being executed, which KUnit will not guarantee [1].
>
> Specifically, `suite->log` is not initialized until a suite object is
> executed. So if KUnit makes a copy of the suite and runs that instead,
> this test dereferences an invalid pointer and (hopefully) segfaults.
>
> N.B. since we no longer assume this, we can no longer verify that
> `suite->log` is *not* allocated during normal execution.
>
> An alternative to this patch that would allow us to test that would
> require exposing an API for the current test to get its current suite.
> Exposing that for one internal kunit test seems like overkill, and
> grants users more footguns (e.g. reusing a test case in multiple suites
> and changing behavior based on the suite name, dynamically modifying the
> setup/cleanup funcs, storing/reading stuff out of the suite->log, etc.).
>
> [1] In a subsequent patch, KUnit will allow running subsets of test
> cases within a suite by making a copy of the suite w/ the filtered test
> list. But there are other reasons KUnit might execute a copy, e.g. if it
> ever wants to support parallel execution of different suites, recovering
> from errors and restarting suites
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>

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

Re: [PATCH v3 2/2] kunit: tool: allow filtering test cases via glob

[Brendan Higgins]

On Tue, Aug 31, 2021 at 10:19 AM Daniel Latypov <dlatypov@google.com> wrote:
>
> Commit 1d71307a6f94 ("kunit: add unit test for filtering suites by
> names") introduced the ability to filter which suites we run via glob.
>
> This change extends it so we can also filter individual test cases
> inside of suites as well.
>
> This is quite useful when, e.g.
> * trying to run just the tests cases you've just added or are working on
> * trying to debug issues with test hermeticity
>
> Examples:
> $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit '*exec*.parse*'
> ...
> ============================================================
> ======== [PASSED] kunit_executor_test ========
> [PASSED] parse_filter_test
> ============================================================
> Testing complete. 1 tests run. 0 failed. 0 crashed.
>
> $ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit '*.no_matching_tests'
> ...
> [ERROR] no tests run!
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> Reviewed-by: David Gow <davidgow@google.com>

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