Commit 11425c45 authored by Xiyu Yang's avatar Xiyu Yang Committed by Christian König
Browse files

drm/ttm: Fix dma_fence refcnt leak when adding move fence 



ttm_bo_add_move_fence() invokes dma_fence_get(), which returns a
reference of the specified dma_fence object to "fence" with increased
refcnt.

When ttm_bo_add_move_fence() returns, local variable "fence" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
ttm_bo_add_move_fence(). When no_wait_gpu flag is equals to true, the
function forgets to decrease the refcnt increased by dma_fence_get(),
causing a refcnt leak.

Fix this issue by calling dma_fence_put() when no_wait_gpu flag is
equals to true.

Signed-off-by: default avatarXiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: default avatarXin Tan <tanxin.ctf@gmail.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/370221/


Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
parent 37cc4b95

drivers/gpu/drm/ttm/ttm_bo.c

+3 −1
Original line number Diff line number Diff line
@@ -881,8 +881,10 @@ static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo, 
	if (!fence)

		return 0;



	if (no_wait_gpu)

	if (no_wait_gpu) {

		dma_fence_put(fence);

		return -EBUSY;

	}



	dma_resv_add_shared_fence(bo->base.resv, fence);