Introduce example_params_test_with_init_dynamic_arr(). This new
KUnit test demonstrates directly assigning a dynamic parameter
array, using the kunit_register_params_array() macro, to a
parameterized test context.
It highlights the use of param_init() and param_exit() for
initialization and exit of a parameterized test, and their
registration to the test case with KUNIT_CASE_PARAM_WITH_INIT().
Signed-off-by: Marie Zhussupova <marievic@google.com>
---
Changes in v2:
- kunit_array_gen_params() is now explicitly passed to
KUNIT_CASE_PARAM_WITH_INIT() to be consistent with
the parameterized test being defined by the existence
of the generate_params() function.
- param_init() was changed to output a log at the start
of a parameterized test.
- The parameter array was changed to be allocated
using kunit_kmalloc_array(), a KUnit memory allocation
API, as that would be the preferred/easier method. To
still demonstrate a use of param_exit(), it now outputs
a log at the end of the parameterized test.
- 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.
---
lib/kunit/kunit-example-test.c | 104 +++++++++++++++++++++++++++++++++
1 file changed, 104 insertions(+)
diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
index f2819ee58965..ff21511889a4 100644
--- a/lib/kunit/kunit-example-test.c
+++ b/lib/kunit/kunit-example-test.c
@@ -393,6 +393,107 @@ static void example_params_test_with_init(struct kunit *test)
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.
@@ -414,6 +515,9 @@ static struct kunit_case example_test_cases[] = {
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),
{}
};
--
2.51.0.rc0.205.g4a044479a3-googOn Tue, 12 Aug 2025 at 06:18, Marie Zhussupova <marievic@google.com> wrote:
>
> Introduce example_params_test_with_init_dynamic_arr(). This new
> KUnit test demonstrates directly assigning a dynamic parameter
> array, using the kunit_register_params_array() macro, to a
> parameterized test context.
>
> It highlights the use of param_init() and param_exit() for
> initialization and exit of a parameterized test, and their
> registration to the test case with KUNIT_CASE_PARAM_WITH_INIT().
>
> Signed-off-by: Marie Zhussupova <marievic@google.com>
> ---
I really like this example now. Thanks!
Reviewed-by: David Gow <davidgow@google.com>
Cheers,
-- David
>
> Changes in v2:
>
> - kunit_array_gen_params() is now explicitly passed to
> KUNIT_CASE_PARAM_WITH_INIT() to be consistent with
> the parameterized test being defined by the existence
> of the generate_params() function.
> - param_init() was changed to output a log at the start
> of a parameterized test.
> - The parameter array was changed to be allocated
> using kunit_kmalloc_array(), a KUnit memory allocation
> API, as that would be the preferred/easier method. To
> still demonstrate a use of param_exit(), it now outputs
> a log at the end of the parameterized test.
> - 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.
>
> ---
> lib/kunit/kunit-example-test.c | 104 +++++++++++++++++++++++++++++++++
> 1 file changed, 104 insertions(+)
>
> diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
> index f2819ee58965..ff21511889a4 100644
> --- a/lib/kunit/kunit-example-test.c
> +++ b/lib/kunit/kunit-example-test.c
> @@ -393,6 +393,107 @@ static void example_params_test_with_init(struct kunit *test)
> 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.
> @@ -414,6 +515,9 @@ static struct kunit_case example_test_cases[] = {
> 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),
> {}
> };
> --
> 2.51.0.rc0.205.g4a044479a3-goog
>
On Mon, Aug 11, 2025 at 6:18 PM Marie Zhussupova <marievic@google.com> wrote:
>
> Introduce example_params_test_with_init_dynamic_arr(). This new
> KUnit test demonstrates directly assigning a dynamic parameter
> array, using the kunit_register_params_array() macro, to a
> parameterized test context.
>
> It highlights the use of param_init() and param_exit() for
> initialization and exit of a parameterized test, and their
> registration to the test case with KUNIT_CASE_PARAM_WITH_INIT().
>
> Signed-off-by: Marie Zhussupova <marievic@google.com>
> ---
>
> Changes in v2:
>
> - kunit_array_gen_params() is now explicitly passed to
> KUNIT_CASE_PARAM_WITH_INIT() to be consistent with
> the parameterized test being defined by the existence
> of the generate_params() function.
> - param_init() was changed to output a log at the start
> of a parameterized test.
> - The parameter array was changed to be allocated
> using kunit_kmalloc_array(), a KUnit memory allocation
> API, as that would be the preferred/easier method. To
> still demonstrate a use of param_exit(), it now outputs
> a log at the end of the parameterized test.
> - 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.
>
Hi!
I am happy with these changes and I really like this test!
Happy to mark this as:
Reviewed-by: Rae Moar <rmoar@google.com>
Thanks!
-Rae
> ---
> lib/kunit/kunit-example-test.c | 104 +++++++++++++++++++++++++++++++++
> 1 file changed, 104 insertions(+)
>
> diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
> index f2819ee58965..ff21511889a4 100644
> --- a/lib/kunit/kunit-example-test.c
> +++ b/lib/kunit/kunit-example-test.c
> @@ -393,6 +393,107 @@ static void example_params_test_with_init(struct kunit *test)
> 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.
> @@ -414,6 +515,9 @@ static struct kunit_case example_test_cases[] = {
> 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),
> {}
> };
> --
> 2.51.0.rc0.205.g4a044479a3-goog
>
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