[PATCH] drm/amd: fix memory leak in amdgpu_cs_sync_rings

[Bert Karwatzki]

amdgpu_sync_get_fence deletes the returned fence from the syncobj, so
the refcount of fence needs to lowered to avoid a memory leak:
https://gitlab.freedesktop.org/drm/amd/-/issues/2360

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 0f4cb41078c1..08eced097bd8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -1222,10 +1222,13 @@ static int amdgpu_cs_sync_rings(struct
amdgpu_cs_parser *p)
                 * next job actually sees the results from the previous
one
                 * before we start executing on the same scheduler
ring.
                 */
-               if (!s_fence || s_fence->sched != sched)
+               if (!s_fence || s_fence->sched != sched) {
+                       dma_fence_put(fence);
                        continue;
+               }
 
                r = amdgpu_sync_fence(&p->gang_leader->explicit_sync,
fence);
+               dma_fence_put(fence);
                if (r)
                        return r;
        }


Bert Karwatzki