drm/gem: WARN about unbalanced handle refcounts

Trying to drop a reference we don't have is a pretty serious bug.
Trying to paper over it is an even worse offense.

So scream into dmesg with a big WARN in case that ever happens.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 44978bcf81255acd3b0c384d37c4fdc0c2c267eb..dcbd2f559e3978b2c4e3362477ecb8ff75a7c4de 100644 (file)
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -238,7 +238,7 @@ static void drm_gem_object_handle_free(struct drm_gem_object *obj)
 void
 drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj)
 {
-       if (atomic_read(&obj->handle_count) == 0)
+       if (WARN_ON(atomic_read(&obj->handle_count) == 0))
                return;
 
        /*