Commit Graph

2 Commits

Author SHA1 Message Date
David Gow 59729170af kunit: Make kunit_remove_resource() idempotent
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>
2022-04-05 13:32:50 -06:00
Daniel Latypov cdebea6968 kunit: split resource API impl from test.c into new resource.c
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>
2022-04-04 16:23:14 -06:00