Merge tag 'linux_kselftest-kunit-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kunit updates from Shuah Khan:

 - New parameterized test features

   KUnit parameterized tests supported two primary methods for getting
   parameters:

    - Defining custom logic within a generate_params() function.

    - Using the KUNIT_ARRAY_PARAM() and KUNIT_ARRAY_PARAM_DESC() macros
      with a pre-defined static array and passing the created
      *_gen_params() to KUNIT_CASE_PARAM().

   These methods present limitations when dealing with dynamically
   generated parameter arrays, or in scenarios where populating
   parameters sequentially via generate_params() is inefficient or
   overly complex.

   These limitations are fixed with a parameterized test method

 - Fix issues in kunit build artifacts cleanup

 - Fix parsing skipped test problem in kselftest framework

 - Enable PCI on UML without triggering WARN()

 - a few other fixes and adds support for new configs such as MIPS

* tag 'linux_kselftest-kunit-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  kunit: Extend kconfig help text for KUNIT_UML_PCI
  rust: kunit: allow `cfg` on `test`s
  kunit: qemu_configs: Add MIPS configurations
  kunit: Enable PCI on UML without triggering WARN()
  Documentation: kunit: Document new parameterized test features
  kunit: Add example parameterized test with direct dynamic parameter array setup
  kunit: Add example parameterized test with shared resource management using the Resource API
  kunit: Enable direct registration of parameter arrays to a KUnit test
  kunit: Pass parameterized test context to generate_params()
  kunit: Introduce param_init/exit for parameterized test context management
  kunit: Add parent kunit for parameterized test context
  kunit: tool: Accept --raw_output=full as an alias of 'all'
  kunit: tool: Parse skipped tests from kselftest.h
  kunit: Always descend into kunit directory during build

1 files changed, 217 insertions, 0 deletions

diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
index 3056d6bc705d..9452b163956f 100644
--- a/lib/kunit/kunit-example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -278,6 +278,218 @@ static void example_slow_test(struct kunit *test)
 }
 
 /*
+ * 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.
  */
@@ -296,6 +508,11 @@ static struct kunit_case example_test_cases[] = {
 	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),
 	{}
 };