Re: [PATCH 6/9] kunit: Enable direct registration of parameter arrays to a KUnit test

On Tue, Jul 29, 2025 at 4:14 PM Rae Moar rmoar@google.com wrote:

On Tue, Jul 29, 2025 at 3:37 PM Marie Zhussupova marievic@google.com wrote:

...

KUnit parameterized tests currently support two primary methods for getting parameters:

1. Defining custom logic within a `generate_params` function.
2. Using the KUNIT_ARRAY_PARAM and KUNIT_ARRAY_PARAM_DESC macros with pre-defined static arrays.

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.

This patch addresses these limitations by adding a new `params_data` field to `struct kunit`, of the type `kunit_params`. The struct `kunit_params` is designed to store the parameter array itself, along with essential metadata including the parameter count, parameter size, and a `get_description` function for providing custom descriptions for individual parameters.

The `params_data` field can be populated by calling the new `kunit_register_params_array` macro from within a `param_init` function. By attaching the parameter array directly to the parent kunit test instance, these parameters can be iterated over in kunit_run_tests() behind the scenes.

This modification provides greater flexibility to the KUnit framework, allowing testers to easily register and utilize both dynamic and static parameter arrays.

Signed-off-by: Marie Zhussupova marievic@google.com

include/kunit/test.h | 54 ++++++++++++++++++++++++++++++++++++++++---- lib/kunit/test.c | 26 ++++++++++++++++++++- 2 files changed, 75 insertions(+), 5 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h index 4ba65dc35710..9143f0e22323 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -245,7 +245,8 @@ static inline char *kunit_status_to_ok_not_ok(enum kunit_status status) */ #define KUNIT_CASE_PARAM_WITH_INIT(test_name, gen_params, init, exit) \ { .run_case = test_name, .name = #test_name, \

•             .generate_params = gen_params,                                \
  

•             .generate_params = (gen_params)                               \
  

•              ?: kunit_get_next_param_and_desc,                            \
              .param_init = init, .param_exit = exit,                       \
              .module_name = KBUILD_MODNAME}
  
  

@@ -294,6 +295,21 @@ struct kunit_suite_set { struct kunit_suite * const *end; };

+/* Stores the pointer to the parameter array and its metadata. */ +struct kunit_params {

•   /*
  

•    * Reference to the parameter array for the parameterized tests. This
  

•    * is NULL if a parameter array wasn't directly passed to the
  

•    * parent kunit struct via the kunit_register_params_array macro.
  

•    */
  

•   const void *params;
  

•   /* Reference to a function that gets the description of a parameter. */
  

•   void (*get_description)(const void *param, char *desc);
  

•   int num_params;
  

•   size_t elem_size;
  

+};

/**

• struct kunit - represents a running instance of a test.

@@ -302,12 +318,14 @@ struct kunit_suite_set {

• @parent: for user to store data that they want to shared across

•     parameterized tests. Typically, the data is provided in
  

•     the param_init function (see &struct kunit_case).
  

• • @params_data: for users to directly store the parameter array.
  • Used to store information about the current context under which the test
  • is running. Most of this data is private and should only be accessed

• • indirectly via public functions; the two exceptions are @priv and @parent
• • which can be used by the test writer to store arbitrary data or data that is
• • available to all parameter test executions, respectively.

• • indirectly via public functions. There are three exceptions to this: @priv,
• • @parent, and @params_data. These members can be used by the test writer to
• • store arbitrary data, data available to all parameter test executions, and
• • the parameter array, respectively.
  */

struct kunit { void *priv; @@ -316,6 +334,8 @@ struct kunit { * during parameterized testing. */ struct kunit *parent;

•   /* Stores the params array and all data related to it. */
  

•   struct kunit_params params_data;
  
    /* private: internal use only. */
    const char *name; /* Read only after initialization! */
  

@@ -386,6 +406,8 @@ void kunit_exec_list_tests(struct kunit_suite_set *suite_set, bool include_attr) struct kunit_suite_set kunit_merge_suite_sets(struct kunit_suite_set init_suite_set, struct kunit_suite_set suite_set);

+const void *kunit_get_next_param_and_desc(struct kunit *test, const void *prev, char *desc);

Hello!

Thanks for sending out this series! I will do a full review of it. For now, I noticed that I get an error when I try to run KUnit tests as modules. I get the following error: "ERROR: modpost: "kunit_get_next_param_and_desc" [lib/kunit/kunit-example-test.ko] undefined!". As a possible fix, I suggest moving the function definition into the header file and making it a static inline function.

Thanks! -Rae

Hello! Feel free to also use EXPORT_SYMBOL_GPL(). Either solution should work here. Thanks!