// SPDX-License-Identifier: GPL-2.0 /* * Example KUnit test to show how to use KUnit. * * Copyright (C) 2019, Google LLC. * Author: Brendan Higgins <brendanhiggins@google.com> */ #include <kunit/test.h> #include <kunit/static_stub.h> /* * This is the most fundamental element of KUnit, the test case. A test case * makes a set EXPECTATIONs and ASSERTIONs about the behavior of some code; if * any expectations or assertions are not met, the test fails; otherwise, the * test passes. * * In KUnit, a test case is just a function with the signature * `void (*)(struct kunit *)`. `struct kunit` is a context object that stores * information about the current test. */ static void example_simple_test(struct kunit *test) { /* * This is an EXPECTATION; it is how KUnit tests things. When you want * to test a piece of code, you set some expectations about what the * code should do. KUnit then runs the test and verifies that the code's * behavior matched what was expected. */ KUNIT_EXPECT_EQ(test, 1 + 1, 2); } /* * This is run once before each test case, see the comment on * example_test_suite for more information. */ static int example_test_init(struct kunit *test) { kunit_info(test, "initializing\n"); return 0; } /* * 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. */ static int example_test_init_suite(struct kunit_suite *suite) { kunit_info(suite, "initializing suite\n"); return 0; } /* * 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) { /* This line should run */ kunit_info(test, "You should not see a line below."); /* Skip (and abort) the test */ kunit_skip(test, "this test should be skipped"); /* This line should not execute */ KUNIT_FAIL(test, "You should not see this line."); } /* * This test should always be marked skipped. */ static void example_mark_skipped_test(struct kunit *test) { /* This line should run */ kunit_info(test, "You should see a line below."); /* Skip (but do not abort) the test */ kunit_mark_skipped(test, "this test should be skipped"); /* This line should run */ kunit_info(test, "You should see this line."); } /* * This test shows off all the types of KUNIT_EXPECT macros. */ static void example_all_expect_macros_test(struct kunit *test) { const u32 array1[] = { 0x0F, 0xFF }; const u32 array2[] = { 0x1F, 0xFF }; /* Boolean assertions */ KUNIT_EXPECT_TRUE(test, true); KUNIT_EXPECT_FALSE(test, false); /* Integer assertions */ KUNIT_EXPECT_EQ(test, 1, 1); /* check == */ KUNIT_EXPECT_GE(test, 1, 1); /* check >= */ KUNIT_EXPECT_LE(test, 1, 1); /* check <= */ KUNIT_EXPECT_NE(test, 1, 0); /* check != */ KUNIT_EXPECT_GT(test, 1, 0); /* check > */ KUNIT_EXPECT_LT(test, 0, 1); /* check < */ /* Pointer assertions */ KUNIT_EXPECT_NOT_ERR_OR_NULL(test, test); KUNIT_EXPECT_PTR_EQ(test, NULL, NULL); KUNIT_EXPECT_PTR_NE(test, test, NULL); KUNIT_EXPECT_NULL(test, NULL); KUNIT_EXPECT_NOT_NULL(test, test); /* String assertions */ KUNIT_EXPECT_STREQ(test, "hi", "hi"); KUNIT_EXPECT_STRNEQ(test, "hi", "bye"); /* Memory block assertions */ KUNIT_EXPECT_MEMEQ(test, array1, array1, sizeof(array1)); KUNIT_EXPECT_MEMNEQ(test, array1, array2, sizeof(array1)); /* * There are also ASSERT variants of all of the above that abort test * execution if they fail. Useful for memory allocations, etc. */ KUNIT_ASSERT_GT(test, sizeof(char), 0); /* * There are also _MSG variants of all of the above that let you include * additional text on failure. */ KUNIT_EXPECT_GT_MSG(test, sizeof(int), 0, "Your ints are 0-bit?!"); 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_obj(*info); 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. */ static struct kunit_case example_test_cases[] = { /* * This is a helper to create a test case object from a test case * function; its exact function is not important to understand how to * use KUnit, just know that this is how you associate test cases with a * test suite. */ KUNIT_CASE(example_simple_test), 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), {} }; /* * This defines a suite or grouping of tests. * * Test cases are defined as belonging to the suite by adding them to * `kunit_cases`. * * Often it is desirable to run some function which will set up things which * will be used by every test; this is accomplished with an `init` function * which runs before each test case is invoked. Similarly, an `exit` function * may be specified which runs after every test case and can be used to for * cleanup. For clarity, running tests in a test suite would behave as follows: * * suite.suite_init(suite); * suite.init(test); * suite.test_case[0](test); * suite.exit(test); * suite.init(test); * suite.test_case[1](test); * suite.exit(test); * suite.suite_exit(suite); * ...; */ 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, }; /* * This registers the above test suite telling KUnit that this is a suite of * tests that need to be run. */ 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");
