From 0f10425e811355986907c54f7d1d06703e406092 Mon Sep 17 00:00:00 2001 From: Grazvydas Ignotas Date: Sun, 23 Oct 2016 21:31:43 +0300 Subject: [PATCH] drm/amdgpu: fix fence slab teardown MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit To free fences, call_rcu() is used, which calls amdgpu_fence_free() after a grace period. During teardown, there is no guarantee all callbacks have finished, so amdgpu_fence_slab may be destroyed before all fences have been freed. If we are lucky, this results in some slab warnings, if not, we get a crash in one of rcu threads because callback is called after amdgpu has already been unloaded. Fix it with a rcu_barrier(). Fixes: b44135351a3a ("drm/amdgpu: RCU protected amdgpu_fence_release") Acked-by: Chunming Zhou Reviewed-by: Christian König Signed-off-by: Grazvydas Ignotas Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 3a2e42f4b897..77b34ec92632 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -68,6 +68,7 @@ int amdgpu_fence_slab_init(void) void amdgpu_fence_slab_fini(void) { + rcu_barrier(); kmem_cache_destroy(amdgpu_fence_slab); } /* -- 2.45.2