| Message ID | 20221110201349.351294-4-dmitry.osipenko@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Move dma_buf_mmap_internal() to dynamic locking specification | expand |
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index 2bcdb935a3ac..283816fbd72f 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -2,6 +2,7 @@ #include <linux/cred.h> #include <linux/device.h> #include <linux/dma-buf.h> +#include <linux/dma-resv.h> #include <linux/highmem.h> #include <linux/init.h> #include <linux/kernel.h> @@ -49,6 +50,8 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma) { struct udmabuf *ubuf = buf->priv; + dma_resv_assert_held(buf->resv); + if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0) return -EINVAL;
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@ffwll.ch> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> --- drivers/dma-buf/udmabuf.c | 3 +++ 1 file changed, 3 insertions(+)