kernel/linux.git/lib/kunit/test.c, branch v6.1.18

kunit: update NULL vs IS_ERR() tests

2022-10-18T21:08:42+00:00

The alloc_string_stream() functions were changed from returning NULL on error to returning error pointers so these caller needs to be updated as well. Fixes: 78b1c6584fce ("kunit: string-stream: Simplify resource use") Signed-off-by: Dan Carpenter Reviewed-by: Daniel Latypov Reviewed-by: David Gow Signed-off-by: Shuah Khan

kunit: remove format func from struct kunit_assert, get it to 0 bytes

2022-10-07T16:16:38+00:00

Each calll to a KUNIT_EXPECT_*() macro creates a local variable which contains a struct kunit_assert. Normally, we'd hope the compiler would be able to optimize this away, but we've seen cases where it hasn't, see https://groups.google.com/g/kunit-dev/c/i3fZXgvBrfA/m/GbrMNej2BAAJ. In changes like commit 21957f90b28f ("kunit: split out part of kunit_assert into a static const"), we've moved more and more parts out of struct kunit_assert and its children types (kunit_binary_assert). This patch removes the final field and gets us to: sizeof(struct kunit_assert) == 0 sizeof(struct kunit_binary_assert) == 24 (on UML x86_64). This also reduces the amount of macro plumbing going on at the cost of passing in one more arg to the base KUNIT_ASSERTION macro and kunit_do_failed_assertion(). Signed-off-by: Daniel Latypov Reviewed-by: David Gow Signed-off-by: Shuah Khan

kunit: make kunit_kfree(NULL) a no-op to match kfree()

2022-10-07T16:15:56+00:00

The real kfree() function will silently return when given a NULL. So a user might reasonably think they can write the following code: char *buffer = NULL; if (param->use_buffer) buffer = kunit_kzalloc(test, 10, GFP_KERNEL); ... kunit_kfree(test, buffer); As-is, kunit_kfree() will mark the test as FAILED when buffer is NULL. (And in earlier times, it would segfault). Let's match the semantics of kfree(). Suggested-by: David Gow Signed-off-by: Daniel Latypov Reviewed-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: make kunit_kfree() not segfault on invalid inputs

2022-10-07T16:15:50+00:00

kunit_kfree() can only work on data ("resources") allocated by KUnit. Currently for code like this, > void *ptr = kmalloc(4, GFP_KERNEL); > kunit_kfree(test, ptr); kunit_kfree() will segfault. It'll try and look up the kunit_resource associated with `ptr` and get a NULL back, but it won't check for this. This means we also segfault if you double-free. Change kunit_kfree() so it'll notice these invalid pointers and respond by failing the test. Implementation: kunit_destroy_resource() does what kunit_kfree() does, but is more generic and returns -ENOENT when it can't find the resource. Sadly, unlike just letting it crash, this means we don't get a stack trace. But kunit_kfree() is so infrequently used it shouldn't be hard to track down the bad callsite anyways. After this change, the above code gives: > # example_simple_test: EXPECTATION FAILED at lib/kunit/test.c:702 > kunit_kfree: 00000000626ec200 already freed or not allocated by kunit Signed-off-by: Daniel Latypov Reviewed-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: make kunit_kfree() only work on pointers from kunit_malloc() and friends

2022-10-07T16:15:44+00:00

kunit_kfree() exists to clean up allocations from kunit_kmalloc() and friends early instead of waiting for this to happen automatically at the end of the test. But it can be used on *anything* registered with the kunit resource API. E.g. the last 2 statements are equivalent: struct kunit_resource *res = something(); kfree(res->data); kunit_put_resource(res); The problem is that there could be multiple resources that point to the same `data`. E.g. you can have a named resource acting as a pseudo-global variable in a test. If you point it to data allocated with kunit_kmalloc(), then calling `kunit_kfree(ptr)` has the chance to delete either the named resource or to kfree `ptr`. Which one it does depends on the order the resources are registered as kunit_kfree() will delete resources in LIFO order. So this patch restricts kunit_kfree() to only working on resources created by kunit_kmalloc(). Calling it is therefore guaranteed to free the memory, not do anything else. Note: kunit_resource_instance_match() wasn't used outside of KUnit, so it should be safe to remove from the public interface. It's also generally dangerous, as shown above, and shouldn't be used. Signed-off-by: Daniel Latypov Reviewed-by: David Gow Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: string-stream: Simplify resource use

2022-10-07T16:15:22+00:00

Currently, KUnit's string streams are themselves "KUnit resources". This is redundant since the stream itself is already allocated with kunit_kzalloc() and will thus be freed automatically at the end of the test. string-stream is only used internally within KUnit, and isn't using the extra features that resources provide like reference counting, being able to locate them dynamically as "test-local variables", etc. Indeed, the resource's refcount is never incremented when the pointer is returned. The fact that it's always manually destroyed is more evidence that the reference counting is unused. Signed-off-by: David Gow Signed-off-by: Daniel Latypov Reviewed-by: Brendan Higgins Signed-off-by: Shuah Khan

kunit: add kunit.enable to enable/disable KUnit test

2022-09-30T19:17:39+00:00

This patch adds the kunit.enable module parameter that will need to be set to true in addition to KUNIT being enabled for KUnit tests to run. The default value is true giving backwards compatibility. However, for the production+testing use case the new config option KUNIT_DEFAULT_ENABLED can be set to N requiring the tester to opt-in by passing kunit.enable=1 to the kernel. Signed-off-by: Joe Fradley Reviewed-by: David Gow Signed-off-by: Shuah Khan

kunit: flatten kunit_suite* to kunit_suite in .kunit_test_suites

2022-07-11T23:13:15+00:00

We currently store kunit suites in the .kunit_test_suites ELF section as a `struct kunit_suite***` (modulo some `const`s). For every test file, we store a struct kunit_suite** NULL-terminated array. This adds quite a bit of complexity to the test filtering code in the executor. Instead, let's just make the .kunit_test_suites section contain a single giant array of struct kunit_suite pointers, which can then be directly manipulated. This array is not NULL-terminated, and so none of the test filtering code needs to NULL-terminate anything. Tested-by: Maíra Canal Reviewed-by: Brendan Higgins Signed-off-by: Daniel Latypov Co-developed-by: David Gow Signed-off-by: David Gow Signed-off-by: Shuah Khan

kunit: unify module and builtin suite definitions

2022-07-11T23:13:09+00:00

Currently, KUnit runs built-in tests and tests loaded from modules differently. For built-in tests, the kunit_test_suite{,s}() macro adds a list of suites in the .kunit_test_suites linker section. However, for kernel modules, a module_init() function is used to run the test suites. This causes problems if tests are included in a module which already defines module_init/exit_module functions, as they'll conflict with the kunit-provided ones. This change removes the kunit-defined module inits, and instead parses the kunit tests from their own section in the module. After module init, we call __kunit_test_suites_init() on the contents of that section, which prepares and runs the suite. This essentially unifies the module- and non-module kunit init formats. Tested-by: Maíra Canal Reviewed-by: Brendan Higgins Signed-off-by: Jeremy Kerr Signed-off-by: Daniel Latypov Signed-off-by: David Gow Signed-off-by: Shuah Khan

kunit: Taint the kernel when KUnit tests are run

2022-07-01T22:38:43+00:00

Make KUnit trigger the new TAINT_TEST taint when any KUnit test is run. Due to KUnit tests not being intended to run on production systems, and potentially causing problems (or security issues like leaking kernel addresses), the kernel's state should not be considered safe for production use after KUnit tests are run. This both marks KUnit modules as test modules using MODULE_INFO() and manually taints the kernel when tests are run (which catches builtin tests). Acked-by: Luis Chamberlain Tested-by: Daniel Latypov Reviewed-by: Brendan Higgins Signed-off-by: David Gow Tested-by: Maíra Canal Signed-off-by: Shuah Khan