[PATCH 3/8] dma-buf: test shared slot allocation when mutex debugging is active

[Christian König]

Set shared_max to the number of shared fences right before we release
the lock.

This way every attempt to add a shared fence without previously
reserving a slot will cause an error.

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 include/linux/reservation.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/reservation.h b/include/linux/reservation.h
index 5ddb0e143721..2f0ffca35780 100644
--- a/include/linux/reservation.h
+++ b/include/linux/reservation.h
@@ -214,6 +214,11 @@ reservation_object_trylock(struct reservation_object *obj)
 static inline void
 reservation_object_unlock(struct reservation_object *obj)
 {
+#ifdef CONFIG_DEBUG_MUTEXES
+	/* Test shared fence slot reservation */
+	if (obj->fence)
+		obj->fence->shared_max = obj->fence->shared_count;
+#endif
 	ww_mutex_unlock(&obj->lock);
 }
 
-- 
2.14.1