Commit d3292dae authored by Dmitry Osipenko's avatar Dmitry Osipenko
Browse files

dma-buf: Make locking consistent in dma_buf_detach() 



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: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/dri-devel/Y1fLfsccW3AS%2Fo+%2F@kili/


Fixes: 809d9c72 ("dma-buf: Move dma_buf_attach() to dynamic locking specification")
Signed-off-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221030154412.8320-2-dmitry.osipenko@collabora.com
parent 38765993

drivers/dma-buf/dma-buf.c

+2 −2
Original line number Diff line number Diff line
@@ -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) {