[PATCH v1 6/6] fastrpc: Assert held reservation lock for dma-buf mmapping

Dmitry Osipenko
2022-11-10T20:15:19Z

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(+)

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