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 dlatypov@google.com Reviewed-by: David Gow davidgow@google.com --- v1 -> v2: no changes --- include/kunit/resource.h | 16 ---------------- lib/kunit/kunit-test.c | 7 +++++++ lib/kunit/test.c | 10 ++++++++-- 3 files changed, 15 insertions(+), 18 deletions(-)
diff --git a/include/kunit/resource.h b/include/kunit/resource.h index 09c2b34d1c61..cf6fb8f2ac1b 100644 --- a/include/kunit/resource.h +++ b/include/kunit/resource.h @@ -300,22 +300,6 @@ typedef bool (*kunit_resource_match_t)(struct kunit *test, struct kunit_resource *res, void *match_data);
-/** - * kunit_resource_instance_match() - Match a resource with the same instance. - * @test: Test case to which the resource belongs. - * @res: The resource. - * @match_data: The resource pointer to match against. - * - * An instance of kunit_resource_match_t that matches a resource whose - * allocation matches @match_data. - */ -static inline bool kunit_resource_instance_match(struct kunit *test, - struct kunit_resource *res, - void *match_data) -{ - return res->data == match_data; -} - /** * kunit_resource_name_match() - Match a resource with the same name. * @test: Test case to which the resource belongs. diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c index 13d0bd8b07a9..4df0335d0d06 100644 --- a/lib/kunit/kunit-test.c +++ b/lib/kunit/kunit-test.c @@ -161,6 +161,13 @@ static void kunit_resource_test_alloc_resource(struct kunit *test) kunit_put_resource(res); }
+static inline bool kunit_resource_instance_match(struct kunit *test, + struct kunit_resource *res, + void *match_data) +{ + return res->data == match_data; +} + /* * Note: tests below use kunit_alloc_and_get_resource(), so as a consequence * they have a reference to the associated resource that they must release diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 0fb2771ca03e..82019a78462e 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -689,12 +689,18 @@ void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t gfp) } EXPORT_SYMBOL_GPL(kunit_kmalloc_array);
+static inline bool kunit_kfree_match(struct kunit *test, + struct kunit_resource *res, void *match_data) +{ + /* Only match resources allocated with kunit_kmalloc() and friends. */ + return res->free == kunit_kmalloc_array_free && res->data == match_data; +} + void kunit_kfree(struct kunit *test, const void *ptr) { struct kunit_resource *res;
- res = kunit_find_resource(test, kunit_resource_instance_match, - (void *)ptr); + res = kunit_find_resource(test, kunit_kfree_match, (void *)ptr);
/* * Removing the resource from the list of resources drops the