When userspace mmaps dma-buf's fd, the dma-buf reservation lock must be held. Add locking sanity check to the dma-buf mmaping callback to ensure that the locking assumption won't regress in the future. Suggested-by: Daniel Vetter <daniel@xxxxxxxx> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> --- drivers/misc/fastrpc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c index 1ad580865525..0f467a71b069 100644 --- a/drivers/misc/fastrpc.c +++ b/drivers/misc/fastrpc.c @@ -6,6 +6,7 @@ #include <linux/device.h> #include <linux/dma-buf.h> #include <linux/dma-mapping.h> +#include <linux/dma-resv.h> #include <linux/idr.h> #include <linux/list.h> #include <linux/miscdevice.h> @@ -682,6 +683,8 @@ static int fastrpc_mmap(struct dma_buf *dmabuf, struct fastrpc_buf *buf = dmabuf->priv; size_t size = vma->vm_end - vma->vm_start; + dma_resv_assert_held(dmabuf->resv); + return dma_mmap_coherent(buf->dev, vma, buf->virt, FASTRPC_PHYS(buf->phys), size); } -- 2.37.3
