1 files changed, 409 insertions, 0 deletions

diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
index 66cc4e2365ec..9452b163956f 100644
--- a/lib/kunit/kunit-example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -7,6 +7,7 @@
  */
 
 #include <kunit/test.h>
+#include <kunit/static_stub.h>
 
 /*
  * This is the most fundamental element of KUnit, the test case. A test case
@@ -41,6 +42,16 @@ static int example_test_init(struct kunit *test)
 }
 
 /*
+ * This is run once after each test case, see the comment on
+ * example_test_suite for more information.
+ */
+static void example_test_exit(struct kunit *test)
+{
+	kunit_info(test, "cleaning up\n");
+}
+
+
+/*
  * This is run once before all test cases in the suite.
  * See the comment on example_test_suite for more information.
  */
@@ -52,6 +63,16 @@ static int example_test_init_suite(struct kunit_suite *suite)
 }
 
 /*
+ * This is run once after all test cases in the suite.
+ * See the comment on example_test_suite for more information.
+ */
+static void example_test_exit_suite(struct kunit_suite *suite)
+{
+	kunit_info(suite, "exiting suite\n");
+}
+
+
+/*
  * This test should always be skipped.
  */
 static void example_skip_test(struct kunit *test)
@@ -130,6 +151,344 @@ static void example_all_expect_macros_test(struct kunit *test)
 	KUNIT_ASSERT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!");
 }
 
+/* This is a function we'll replace with static stubs. */
+static int add_one(int i)
+{
+	/* This will trigger the stub if active. */
+	KUNIT_STATIC_STUB_REDIRECT(add_one, i);
+
+	return i + 1;
+}
+
+/* This is used as a replacement for the above function. */
+static int subtract_one(int i)
+{
+	/* We don't need to trigger the stub from the replacement. */
+
+	return i - 1;
+}
+
+/*
+ * If the function to be replaced is static within a module it is
+ * useful to export a pointer to that function instead of having
+ * to change the static function to a non-static exported function.
+ *
+ * This pointer simulates a module exporting a pointer to a static
+ * function.
+ */
+static int (* const add_one_fn_ptr)(int i) = add_one;
+
+/*
+ * This test shows the use of static stubs.
+ */
+static void example_static_stub_test(struct kunit *test)
+{
+	/* By default, function is not stubbed. */
+	KUNIT_EXPECT_EQ(test, add_one(1), 2);
+
+	/* Replace add_one() with subtract_one(). */
+	kunit_activate_static_stub(test, add_one, subtract_one);
+
+	/* add_one() is now replaced. */
+	KUNIT_EXPECT_EQ(test, add_one(1), 0);
+
+	/* Return add_one() to normal. */
+	kunit_deactivate_static_stub(test, add_one);
+	KUNIT_EXPECT_EQ(test, add_one(1), 2);
+}
+
+/*
+ * This test shows the use of static stubs when the function being
+ * replaced is provided as a pointer-to-function instead of the
+ * actual function. This is useful for providing access to static
+ * functions in a module by exporting a pointer to that function
+ * instead of having to change the static function to a non-static
+ * exported function.
+ */
+static void example_static_stub_using_fn_ptr_test(struct kunit *test)
+{
+	/* By default, function is not stubbed. */
+	KUNIT_EXPECT_EQ(test, add_one(1), 2);
+
+	/* Replace add_one() with subtract_one(). */
+	kunit_activate_static_stub(test, add_one_fn_ptr, subtract_one);
+
+	/* add_one() is now replaced. */
+	KUNIT_EXPECT_EQ(test, add_one(1), 0);
+
+	/* Return add_one() to normal. */
+	kunit_deactivate_static_stub(test, add_one_fn_ptr);
+	KUNIT_EXPECT_EQ(test, add_one(1), 2);
+}
+
+static const struct example_param {
+	int value;
+} example_params_array[] = {
+	{ .value = 3, },
+	{ .value = 2, },
+	{ .value = 1, },
+	{ .value = 0, },
+};
+
+static void example_param_get_desc(const struct example_param *p, char *desc)
+{
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "example value %d", p->value);
+}
+
+KUNIT_ARRAY_PARAM(example, example_params_array, example_param_get_desc);
+
+/*
+ * This test shows the use of params.
+ */
+static void example_params_test(struct kunit *test)
+{
+	const struct example_param *param = test->param_value;
+
+	/* By design, param pointer will not be NULL */
+	KUNIT_ASSERT_NOT_NULL(test, param);
+
+	/* Test can be skipped on unsupported param values */
+	if (!is_power_of_2(param->value))
+		kunit_skip(test, "unsupported param value %d", param->value);
+
+	/* You can use param values for parameterized testing */
+	KUNIT_EXPECT_EQ(test, param->value % param->value, 0);
+}
+
+/*
+ * This test shows the use of test->priv.
+ */
+static void example_priv_test(struct kunit *test)
+{
+	/* unless setup in suite->init(), test->priv is NULL */
+	KUNIT_ASSERT_NULL(test, test->priv);
+
+	/* but can be used to pass arbitrary data to other functions */
+	test->priv = kunit_kzalloc(test, 1, GFP_KERNEL);
+	KUNIT_EXPECT_NOT_NULL(test, test->priv);
+	KUNIT_ASSERT_PTR_EQ(test, test->priv, kunit_get_current_test()->priv);
+}
+
+/*
+ * This test should always pass. Can be used to practice filtering attributes.
+ */
+static void example_slow_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1 + 1, 2);
+}
+
+/*
+ * This custom function allocates memory and sets the information we want
+ * stored in the kunit_resource->data field.
+ */
+static int example_resource_init(struct kunit_resource *res, void *context)
+{
+	int *info = kmalloc(sizeof(*info), GFP_KERNEL);
+
+	if (!info)
+		return -ENOMEM;
+	*info = *(int *)context;
+	res->data = info;
+	return 0;
+}
+
+/*
+ * This function deallocates memory for the kunit_resource->data field.
+ */
+static void example_resource_free(struct kunit_resource *res)
+{
+	kfree(res->data);
+}
+
+/*
+ * This match function is invoked by kunit_find_resource() to locate
+ * a test resource based on certain criteria.
+ */
+static bool example_resource_alloc_match(struct kunit *test,
+					 struct kunit_resource *res,
+					 void *match_data)
+{
+	return res->data && res->free == example_resource_free;
+}
+
+/*
+ * This is an example of a function that provides a description for each of the
+ * parameters in a parameterized test.
+ */
+static void example_param_array_get_desc(struct kunit *test, const void *p, char *desc)
+{
+	const struct example_param *param = p;
+
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE,
+		 "example check if %d is less than or equal to 3", param->value);
+}
+
+/*
+ * This function gets passed in the parameterized test context i.e. the
+ * struct kunit belonging to the parameterized test. You can use this function
+ * to add resources you want shared across the whole parameterized test or
+ * for additional setup.
+ */
+static int example_param_init(struct kunit *test)
+{
+	int ctx = 3; /* Data to be stored. */
+	size_t arr_size = ARRAY_SIZE(example_params_array);
+
+	/*
+	 * This allocates a struct kunit_resource, sets its data field to
+	 * ctx, and adds it to the struct kunit's resources list. Note that
+	 * this is parameterized test managed. So, it doesn't need to have
+	 * a custom exit function to deallocation as it will get cleaned up at
+	 * the end of the parameterized test.
+	 */
+	void *data = kunit_alloc_resource(test, example_resource_init, example_resource_free,
+					  GFP_KERNEL, &ctx);
+
+	if (!data)
+		return -ENOMEM;
+	/*
+	 * Pass the parameter array information to the parameterized test context
+	 * struct kunit. Note that you will need to provide kunit_array_gen_params()
+	 * as the generator function to KUNIT_CASE_PARAM_WITH_INIT() when registering
+	 * a parameter array this route.
+	 */
+	kunit_register_params_array(test, example_params_array, arr_size,
+				    example_param_array_get_desc);
+	return 0;
+}
+
+/*
+ * This is an example of a test that uses shared resources available in the
+ * parameterized test context.
+ */
+static void example_params_test_with_init(struct kunit *test)
+{
+	int threshold;
+	struct kunit_resource *res;
+	const struct example_param *param = test->param_value;
+
+	/* By design, param pointer will not be NULL. */
+	KUNIT_ASSERT_NOT_NULL(test, param);
+
+	/*
+	 * Here we pass test->parent to search for shared resources in the
+	 * parameterized test context.
+	 */
+	res = kunit_find_resource(test->parent, example_resource_alloc_match, NULL);
+
+	KUNIT_ASSERT_NOT_NULL(test, res);
+
+	/* Since kunit_resource->data is a void pointer we need to typecast it. */
+	threshold = *((int *)res->data);
+
+	/* Assert that the parameter is less than or equal to a certain threshold. */
+	KUNIT_ASSERT_LE(test, param->value, threshold);
+
+	/* This decreases the reference count after calling kunit_find_resource(). */
+	kunit_put_resource(res);
+}
+
+/*
+ * Helper function to create a parameter array of Fibonacci numbers. This example
+ * highlights a parameter generation scenario that is:
+ * 1. Not feasible to fully pre-generate at compile time.
+ * 2. Challenging to implement with a standard generate_params() function,
+ * as it only provides the previous parameter, while Fibonacci requires
+ * access to two preceding values for calculation.
+ */
+static void *make_fibonacci_params(struct kunit *test, size_t seq_size)
+{
+	int *seq;
+
+	if (seq_size <= 0)
+		return NULL;
+	/*
+	 * Using kunit_kmalloc_array here ties the lifetime of the array to
+	 * the parameterized test i.e. it will get automatically cleaned up
+	 * by KUnit after the parameterized test finishes.
+	 */
+	seq = kunit_kmalloc_array(test, seq_size, sizeof(int), GFP_KERNEL);
+
+	if (!seq)
+		return NULL;
+	if (seq_size >= 1)
+		seq[0] = 0;
+	if (seq_size >= 2)
+		seq[1] = 1;
+	for (int i = 2; i < seq_size; i++)
+		seq[i] = seq[i - 1] + seq[i - 2];
+	return seq;
+}
+
+/*
+ * This is an example of a function that provides a description for each of the
+ * parameters.
+ */
+static void example_param_dynamic_arr_get_desc(struct kunit *test, const void *p, char *desc)
+{
+	const int *fib_num = p;
+
+	snprintf(desc, KUNIT_PARAM_DESC_SIZE, "fibonacci param: %d", *fib_num);
+}
+
+/*
+ * Example of a parameterized test param_init() function that registers a dynamic
+ * array of parameters.
+ */
+static int example_param_init_dynamic_arr(struct kunit *test)
+{
+	size_t seq_size;
+	int *fibonacci_params;
+
+	kunit_info(test, "initializing parameterized test\n");
+
+	seq_size = 6;
+	fibonacci_params = make_fibonacci_params(test, seq_size);
+
+	if (!fibonacci_params)
+		return -ENOMEM;
+
+	/*
+	 * Passes the dynamic parameter array information to the parameterized test
+	 * context struct kunit. The array and its metadata will be stored in
+	 * test->parent->params_array. The array itself will be located in
+	 * params_data.params.
+	 *
+	 * Note that you will need to pass kunit_array_gen_params() as the
+	 * generator function to KUNIT_CASE_PARAM_WITH_INIT() when registering
+	 * a parameter array this route.
+	 */
+	kunit_register_params_array(test, fibonacci_params, seq_size,
+				    example_param_dynamic_arr_get_desc);
+	return 0;
+}
+
+/*
+ * Example of a parameterized test param_exit() function that outputs a log
+ * at the end of the parameterized test. It could also be used for any other
+ * teardown logic.
+ */
+static void example_param_exit_dynamic_arr(struct kunit *test)
+{
+	kunit_info(test, "exiting parameterized test\n");
+}
+
+/*
+ * Example of test that uses the registered dynamic array to perform assertions
+ * and expectations.
+ */
+static void example_params_test_with_init_dynamic_arr(struct kunit *test)
+{
+	const int *param = test->param_value;
+	int param_val;
+
+	/* By design, param pointer will not be NULL. */
+	KUNIT_ASSERT_NOT_NULL(test, param);
+
+	param_val = *param;
+	KUNIT_EXPECT_EQ(test, param_val - param_val, 0);
+}
+
 /*
  * Here we make a list of all the test cases we want to add to the test suite
  * below.
@@ -145,6 +504,16 @@ static struct kunit_case example_test_cases[] = {
 	KUNIT_CASE(example_skip_test),
 	KUNIT_CASE(example_mark_skipped_test),
 	KUNIT_CASE(example_all_expect_macros_test),
+	KUNIT_CASE(example_static_stub_test),
+	KUNIT_CASE(example_static_stub_using_fn_ptr_test),
+	KUNIT_CASE(example_priv_test),
+	KUNIT_CASE_PARAM(example_params_test, example_gen_params),
+	KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init, kunit_array_gen_params,
+				   example_param_init, NULL),
+	KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init_dynamic_arr,
+				   kunit_array_gen_params, example_param_init_dynamic_arr,
+				   example_param_exit_dynamic_arr),
+	KUNIT_CASE_SLOW(example_slow_test),
 	{}
 };
 
@@ -173,7 +542,9 @@ static struct kunit_case example_test_cases[] = {
 static struct kunit_suite example_test_suite = {
 	.name = "example",
 	.init = example_test_init,
+	.exit = example_test_exit,
 	.suite_init = example_test_init_suite,
+	.suite_exit = example_test_exit_suite,
 	.test_cases = example_test_cases,
 };
 
@@ -183,4 +554,42 @@ static struct kunit_suite example_test_suite = {
  */
 kunit_test_suites(&example_test_suite);
 
+static int __init init_add(int x, int y)
+{
+	return (x + y);
+}
+
+/*
+ * This test should always pass. Can be used to test init suites.
+ */
+static void __init example_init_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, init_add(1, 1), 2);
+}
+
+/*
+ * The kunit_case struct cannot be marked as __initdata as this will be
+ * used in debugfs to retrieve results after test has run
+ */
+static struct kunit_case __refdata example_init_test_cases[] = {
+	KUNIT_CASE(example_init_test),
+	{}
+};
+
+/*
+ * The kunit_suite struct cannot be marked as __initdata as this will be
+ * used in debugfs to retrieve results after test has run
+ */
+static struct kunit_suite example_init_test_suite = {
+	.name = "example_init",
+	.test_cases = example_init_test_cases,
+};
+
+/*
+ * This registers the test suite and marks the suite as using init data
+ * and/or functions.
+ */
+kunit_test_init_section_suites(&example_init_test_suite);
+
+MODULE_DESCRIPTION("Example KUnit test suite");
 MODULE_LICENSE("GPL v2");