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authorDaniel Latypov <dlatypov@google.com>2022-07-22 17:15:32 +0000
committerShuah Khan <skhan@linuxfoundation.org>2022-10-07 10:15:44 -0600
commit047a8a0a2da716fecfd325d21ccf509c431992d9 (patch)
treee437da59bc25dfba6f15fe8c6a4864f1ca6b4d48 /lib
parent4db4598b5ed8fc26f5fd9312623a9ec5cebbe74a (diff)
kunit: make kunit_kfree() only work on pointers from kunit_malloc() and friends
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> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/kunit/kunit-test.c7
-rw-r--r--lib/kunit/test.c10
2 files changed, 15 insertions, 2 deletions
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 638df598bcf9..0f9c1fb32da7 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -713,12 +713,18 @@ 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