On Fri, Jul 22, 2022 at 1:15 PM Daniel Latypov <dlatypov@xxxxxxxxxx> wrote: > > 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@xxxxxxxxxx> > Reviewed-by: David Gow <davidgow@xxxxxxxxxx> Reviewed-by: Brendan Higgins <brendanhiggins@xxxxxxxxxx>
