[PATCH] kunit: Fix merge issue in suite filtering test

[David Gow]

There were a couple of errors introuced when
"kunit: add unit test for filtering suites by names"[1] was merged in
c9d80ffc5a.

An erroneous '+' was introduced in executor.c, and the executor_test.c
file went missing. This causes the kernel to fail to compile if
CONFIG_KUNIT is enabled, as reported in [2,3].

As with the original, I've tested by running just the new tests using
itself:
$ ./tools/testing/kunit/kunit.py run '*exec*'

[1]: https://lore.kernel.org/linux-kselftest/20210421020427.2384721-1-dlatypov@xxxxxxxxxx/
[2]: https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx/thread/6IKQX5JXZF7I3NFH4IAWUMHXEQSCPNDP/
[3]: https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx/thread/EKY7ZH5YDCCTSJF2G7XFPMGIXQSUVD3Y/

Fixes: c9d80ffc5a ("kunit: add unit test for filtering suites by names")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
---

This is another fix for the kunit-fixes branch, where there seems to
have been an issue merging the "kunit: add unit test for filtering
suites by names" patch here:
https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/commit/?h=kunit-fixes&id=c9d80ffc5a0a30955de0b8c5c46a05906d417800

Again, feel free to squash this into the original patch if that works
better.

Cheers,
-- David

 lib/kunit/executor.c      |   2 +-
 lib/kunit/executor_test.c | 133 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 134 insertions(+), 1 deletion(-)
 create mode 100644 lib/kunit/executor_test.c

diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index 672f91486d23..acd1de436f59 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -23,7 +23,7 @@ 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,
+kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
 			const char *filter_glob)
 {
 	int i, n = 0;
diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
new file mode 100644
index 000000000000..cdbe54b16501
--- /dev/null
+++ b/lib/kunit/executor_test.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for the KUnit executor.
+ *
+ * Copyright (C) 2021, Google LLC.
+ * Author: Daniel Latypov <dlatypov@xxxxxxxxxx>
+ */
+
+#include <kunit/test.h>
+
+static void kfree_at_end(struct kunit *test, const void *to_free);
+static struct kunit_suite *alloc_fake_suite(struct kunit *test,
+					    const char *suite_name);
+
+static void filter_subsuite_test(struct kunit *test)
+{
+	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
+	struct kunit_suite * const *filtered;
+
+	subsuite[0] = alloc_fake_suite(test, "suite1");
+	subsuite[1] = alloc_fake_suite(test, "suite2");
+
+	/* Want: suite1, suite2, NULL -> suite2, NULL */
+	filtered = kunit_filter_subsuite(subsuite, "suite2*");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
+	kfree_at_end(test, filtered);
+
+	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_to_empty_test(struct kunit *test)
+{
+	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
+	struct kunit_suite * const *filtered;
+
+	subsuite[0] = alloc_fake_suite(test, "suite1");
+	subsuite[1] = alloc_fake_suite(test, "suite2");
+
+	filtered = kunit_filter_subsuite(subsuite, "not_found");
+	kfree_at_end(test, filtered); /* just in case */
+
+	KUNIT_EXPECT_FALSE_MSG(test, filtered,
+			       "should be NULL to indicate no match");
+}
+
+static void kfree_subsuites_at_end(struct kunit *test, struct suite_set *suite_set)
+{
+	struct kunit_suite * const * const *suites;
+
+	kfree_at_end(test, suite_set->start);
+	for (suites = suite_set->start; suites < suite_set->end; suites++)
+		kfree_at_end(test, *suites);
+}
+
+static void filter_suites_test(struct kunit *test)
+{
+	/* Suites per-file are stored as a NULL terminated array */
+	struct kunit_suite *subsuites[2][2] = {
+		{NULL, NULL},
+		{NULL, NULL},
+	};
+	/* Match the memory layout of suite_set */
+	struct kunit_suite * const * const suites[2] = {
+		subsuites[0], subsuites[1],
+	};
+
+	const struct suite_set suite_set = {
+		.start = suites,
+		.end = suites + 2,
+	};
+	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");
+
+	/* Filter out suite1 */
+	filtered = kunit_filter_suites(&suite_set, "suite0");
+	kfree_subsuites_at_end(test, &filtered); /* let us use ASSERTs without leaking */
+	KUNIT_ASSERT_EQ(test, filtered.end - filtered.start, (ptrdiff_t)1);
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0]);
+	KUNIT_EXPECT_STREQ(test, (const char *)filtered.start[0][0]->name, "suite0");
+}
+
+static struct kunit_case executor_test_cases[] = {
+	KUNIT_CASE(filter_subsuite_test),
+	KUNIT_CASE(filter_subsuite_to_empty_test),
+	KUNIT_CASE(filter_suites_test),
+	{}
+};
+
+static struct kunit_suite executor_test_suite = {
+	.name = "kunit_executor_test",
+	.test_cases = executor_test_cases,
+};
+
+kunit_test_suites(&executor_test_suite);
+
+/* Test helpers */
+
+static void kfree_res_free(struct kunit_resource *res)
+{
+	kfree(res->data);
+}
+
+/* Use the resource API to register a call to kfree(to_free).
+ * Since we never actually use the resource, it's safe to use on const data.
+ */
+static void kfree_at_end(struct kunit *test, const void *to_free)
+{
+	/* kfree() handles NULL already, but avoid allocating a no-op cleanup. */
+	if (IS_ERR_OR_NULL(to_free))
+		return;
+	kunit_alloc_and_get_resource(test, NULL, kfree_res_free, GFP_KERNEL,
+				     (void *)to_free);
+}
+
+static struct kunit_suite *alloc_fake_suite(struct kunit *test,
+					    const char *suite_name)
+{
+	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);
+
+	return suite;
+}
-- 
2.32.0.93.g670b81a890-goog