[v1,6/6] fastrpc: Assert held reservation lock for dma-buf mmapping
Commit Message
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/misc/fastrpc.c | 3 +++
1 file changed, 3 insertions(+)
@@ -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);
}