From 11425c4519e2c974a100fc984867046d905b9380 Mon Sep 17 00:00:00 2001 From: Xiyu Yang Date: Sat, 13 Jun 2020 20:30:25 +0800 Subject: [PATCH] drm/ttm: Fix dma_fence refcnt leak when adding move fence MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: Xiyu Yang Signed-off-by: Xin Tan Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/370221/ Signed-off-by: Christian König --- drivers/gpu/drm/ttm/ttm_bo.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 9e07c3f..ef5bc00 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -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); -- 2.7.4