kunit: tool: allow filtering test cases via glob

Commit 1d71307a ("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>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

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.

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();

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) {}
+
+static 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_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;
 }

tools/testing/kunit/kunit.py

@@ -263,9 +263,8 @@ 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='',