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>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
We've split out the declarations from include/kunit/test.h into
resource.h.
This patch splits out the definitions as well for consistency.
A side effect of this is git blame won't properly track history by
default, users need to run
$ git blame -L ,1 -C13 lib/kunit/resource.c
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>