From 12afce08ed51a67aafcc678f4b6e428d71b1f6fb Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Thu, 29 Aug 2019 12:33:01 +0200 Subject: [PATCH] drm/virtio: add fence sanity check Make sure we don't leak half-initialized fences outside the driver. Signed-off-by: Gerd Hoffmann Reviewed-by: Chia-I Wu Link: http://patchwork.freedesktop.org/patch/msgid/20190829103301.3539-19-kraxel@redhat.com --- drivers/gpu/drm/virtio/virtgpu_fence.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_fence.c b/drivers/gpu/drm/virtio/virtgpu_fence.c index a0514f5..a4b9881 100644 --- a/drivers/gpu/drm/virtio/virtgpu_fence.c +++ b/drivers/gpu/drm/virtio/virtgpu_fence.c @@ -41,6 +41,10 @@ bool virtio_fence_signaled(struct dma_fence *f) { struct virtio_gpu_fence *fence = to_virtio_fence(f); + if (WARN_ON_ONCE(fence->f.seqno == 0)) + /* leaked fence outside driver before completing + * initialization with virtio_gpu_fence_emit */ + return false; if (atomic64_read(&fence->drv->last_seq) >= fence->f.seqno) return true; return false; -- 2.7.4