[PATCH v2 2/7] kunit: Introduce param_init/exit for parameterized test context management

Rae Moar rmoar at google.com
Tue Aug 12 22:22:20 UTC 2025


On Mon, Aug 11, 2025 at 6:17 PM Marie Zhussupova <marievic at google.com> wrote:
>
> Add (*param_init) and (*param_exit) function pointers to
> `struct kunit_case`. Users will be able to set them
> via the new KUNIT_CASE_PARAM_WITH_INIT() macro.
>
> param_init/exit will be invoked by kunit_run_tests() once before
> and once after the parameterized test, respectively.
> They will receive the `struct kunit` that holds the parameterized
> test context; facilitating init and exit for shared state.
>
> This patch also sets param_init/exit to None in
> rust/kernel/kunit.rs.
>
> Signed-off-by: Marie Zhussupova <marievic at google.com>
> ---
>
> Changes in v2:
>
> - param init/exit were set to None
>   in rust/kernel/kunit.rs to fix the Rust breakage.
> - The name of __kunit_init_parent_test was
>   changed to kunit_init_parent_param_test and
>   its call was changed to happen only if the
>   test is parameterized.
> - The param_exit call was also moved inside
>   the check for if the test is parameterized.
> - KUNIT_CASE_PARAM_WITH_INIT() macro logic was changed
>   to not automatically set generate_params() to KUnit's
>   built-in generator function. Instead, the test user
>   will be asked to provide it themselves.
> - The comments and the commit message were changed to
>   reflect the parameterized testing terminology. See
>   the patch series cover letter change log for the
>   definitions.

Hello!

This patch looks good to me. Thank you for fixing the Rust breakage! I
also appreciate the terminology changes here as well.

Reviewed-by: Rae Moar <rmoar at google.com>

Thanks!

-Rae

>
> ---
>  include/kunit/test.h | 25 +++++++++++++++++++++++++
>  lib/kunit/test.c     | 20 ++++++++++++++++++++
>  rust/kernel/kunit.rs |  4 ++++
>  3 files changed, 49 insertions(+)
>
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index b47b9a3102f3..d2e1b986b161 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -92,6 +92,8 @@ struct kunit_attributes {
>   * @name:     the name of the test case.
>   * @generate_params: the generator function for parameterized tests.
>   * @attr:     the attributes associated with the test
> + * @param_init: The init function to run before a parameterized test.
> + * @param_exit: The exit function to run after a parameterized test.
>   *
>   * A test case is a function with the signature,
>   * ``void (*)(struct kunit *)``
> @@ -128,6 +130,8 @@ struct kunit_case {
>         const char *name;
>         const void* (*generate_params)(const void *prev, char *desc);
>         struct kunit_attributes attr;
> +       int (*param_init)(struct kunit *test);
> +       void (*param_exit)(struct kunit *test);
>
>         /* private: internal use only. */
>         enum kunit_status status;
> @@ -218,6 +222,27 @@ static inline char *kunit_status_to_ok_not_ok(enum kunit_status status)
>                   .generate_params = gen_params,                                \
>                   .attr = attributes, .module_name = KBUILD_MODNAME}
>
> +/**
> + * KUNIT_CASE_PARAM_WITH_INIT - Define a parameterized KUnit test case with custom
> + * param_init() and param_exit() functions.
> + * @test_name: The function implementing the test case.
> + * @gen_params: The function to generate parameters for the test case.
> + * @init: A reference to the param_init() function to run before a parameterized test.
> + * @exit: A reference to the param_exit() function to run after a parameterized test.
> + *
> + * Provides the option to register param_init() and param_exit() functions.
> + * param_init/exit will be passed the parameterized test context and run once
> + * before and once after the parameterized test. The init function can be used
> + * to add resources to share between parameter runs, and any other setup logic.
> + * The exit function can be used to clean up resources that were not managed by
> + * the parameterized test, and any other teardown logic.
> + */
> +#define KUNIT_CASE_PARAM_WITH_INIT(test_name, gen_params, init, exit)          \
> +               { .run_case = test_name, .name = #test_name,                    \
> +                 .generate_params = gen_params,                                \
> +                 .param_init = init, .param_exit = exit,                       \
> +                 .module_name = KBUILD_MODNAME}
> +
>  /**
>   * struct kunit_suite - describes a related collection of &struct kunit_case
>   *
> diff --git a/lib/kunit/test.c b/lib/kunit/test.c
> index 14a8bd846939..49a5e6c30c86 100644
> --- a/lib/kunit/test.c
> +++ b/lib/kunit/test.c
> @@ -641,6 +641,19 @@ static void kunit_accumulate_stats(struct kunit_result_stats *total,
>         total->total += add.total;
>  }
>
> +static void kunit_init_parent_param_test(struct kunit_case *test_case, struct kunit *test)
> +{
> +       if (test_case->param_init) {
> +               int err = test_case->param_init(test);
> +
> +               if (err) {
> +                       kunit_err(test_case, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
> +                               "# failed to initialize parent parameter test.");
> +                       test_case->status = KUNIT_FAILURE;
> +               }
> +       }
> +}
> +
>  int kunit_run_tests(struct kunit_suite *suite)
>  {
>         char param_desc[KUNIT_PARAM_DESC_SIZE];
> @@ -678,6 +691,7 @@ int kunit_run_tests(struct kunit_suite *suite)
>                         kunit_run_case_catch_errors(suite, test_case, &test);
>                         kunit_update_stats(&param_stats, test.status);
>                 } else {
> +                       kunit_init_parent_param_test(test_case, &test);
>                         /* Get initial param. */
>                         param_desc[0] = '\0';
>                         /* TODO: Make generate_params try-catch */
> @@ -714,6 +728,12 @@ int kunit_run_tests(struct kunit_suite *suite)
>                                 param_desc[0] = '\0';
>                                 curr_param = test_case->generate_params(curr_param, param_desc);
>                         }
> +                       /*
> +                        * TODO: Put into a try catch. Since we don't need suite->exit
> +                        * for it we can't reuse kunit_try_run_cleanup for this yet.
> +                        */
> +                       if (test_case->param_exit)
> +                               test_case->param_exit(&test);
>                         /* TODO: Put this kunit_cleanup into a try-catch. */
>                         kunit_cleanup(&test);
>                 }
> diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
> index 4b8cdcb21e77..cda64574b44d 100644
> --- a/rust/kernel/kunit.rs
> +++ b/rust/kernel/kunit.rs
> @@ -207,6 +207,8 @@ pub const fn kunit_case(
>          status: kernel::bindings::kunit_status_KUNIT_SUCCESS,
>          module_name: core::ptr::null_mut(),
>          log: core::ptr::null_mut(),
> +        param_init: None,
> +        param_exit: None,
>      }
>  }
>
> @@ -226,6 +228,8 @@ pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
>          status: kernel::bindings::kunit_status_KUNIT_SUCCESS,
>          module_name: core::ptr::null_mut(),
>          log: core::ptr::null_mut(),
> +        param_init: None,
> +        param_exit: None,
>      }
>  }
>
> --
> 2.51.0.rc0.205.g4a044479a3-goog
>


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