From d3292daee319581d0a502fcd8ef3c3c285a1750a Mon Sep 17 00:00:00 2001 From: Dmitry Osipenko Date: Sun, 30 Oct 2022 18:44:11 +0300 Subject: [PATCH] dma-buf: Make locking consistent in dma_buf_detach() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The dma_buf_detach() locks attach->dmabuf->resv and then unlocks dmabuf->resv, which could be a two different locks from a static code checker perspective. In particular this triggers Smatch to report the "double unlock" error. Make the locking pointers consistent. Reported-by: Dan Carpenter Reviewed-by: Christian König Link: https://lore.kernel.org/dri-devel/Y1fLfsccW3AS%2Fo+%2F@kili/ Fixes: 809d9c72c2f8 ("dma-buf: Move dma_buf_attach() to dynamic locking specification") Signed-off-by: Dmitry Osipenko Link: https://patchwork.freedesktop.org/patch/msgid/20221030154412.8320-2-dmitry.osipenko@collabora.com --- drivers/dma-buf/dma-buf.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index c40d72d318fd..13bfd2d09c56 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -995,10 +995,10 @@ static void __unmap_dma_buf(struct dma_buf_attachment *attach, */ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) { - if (WARN_ON(!dmabuf || !attach)) + if (WARN_ON(!dmabuf || !attach || dmabuf != attach->dmabuf)) return; - dma_resv_lock(attach->dmabuf->resv, NULL); + dma_resv_lock(dmabuf->resv, NULL); if (attach->sgt) {