Conor McCarthy : vkd3d: Handle the case where a descriptor is null and is concurrently written non-null.

[Alexandre Julliard]

Module: vkd3d
Branch: master
Commit: 3d49b59a68687cf32ee489c22d133c9f758a37c6
URL:    https://gitlab.winehq.org/wine/vkd3d/-/commit/3d49b59a68687cf32ee489c22d133c...

Author: Conor McCarthy 
Date:   Tue Jul 25 15:14:36 2023 +1000

vkd3d: Handle the case where a descriptor is null and is concurrently written non-null.

If view is null and the comparison (view == src->s.u.object) is false,
vkd3d_view_decref will be called on null.

---

libs/vkd3d/vkd3d_private.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libs/vkd3d/vkd3d_private.h b/libs/vkd3d/vkd3d_private.h
index 3be12be7..a5eed59a 100644
--- a/libs/vkd3d/vkd3d_private.h
+++ b/libs/vkd3d/vkd3d_private.h
@@ -882,8 +882,9 @@ static inline void *d3d12_desc_get_object_ref(const volatile struct d3d12_desc *
     {
         do
         {
-            view = src->s.u.object;
-        } while (view && !vkd3d_view_incref(view));
+            if (!(view = src->s.u.object))
+                return NULL;
+        } while (!vkd3d_view_incref(view));

/* Check if the object is still in src to handle the case where it was
          * already freed and reused elsewhere when the refcount was incremented. */