On Fri, Mar 18, 2022 at 2:50 AM David Gow davidgow@google.com wrote:
The kunit_remove_resource() function is used to unlink a resource from the list of resources in the test, making it no longer show up in kunit_find_resource().
However, this could lead to a race condition if two threads called kunit_remove_resource() on the same resource at the same time: the resource would be removed from the list twice (causing a crash at the second list_del()), and the refcount for the resource would be decremented twice (instead of once, for the reference held by the resource list).
Fix both problems, the first by using list_del_init(), and the second by checking if the resource has already been removed using list_empty(), and only decrementing its refcount if it has not.
Also add a KUnit test for the kunit_remove_resource() function which tests this behaviour.
Reported-by: Daniel Latypov dlatypov@google.com Signed-off-by: David Gow davidgow@google.com
Reviewed-by: Brendan Higgins brendanhiggins@google.com