[RFC v2 11/13] sync_file: Protect access to driver and timeline name

[Tvrtko Ursulin]

Protect the access to driver and timeline name which otherwise could be
freed as dma-fence exported is signalling fences.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
---
 drivers/dma-buf/sync_file.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 212df4b849fe..ad87116baa24 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -136,11 +136,13 @@ char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len)
 	} else {
 		struct dma_fence *fence = sync_file->fence;
 
+		dma_fence_access_begin();
 		snprintf(buf, len, "%s-%s%llu-%lld",
 			 dma_fence_driver_name(fence),
 			 dma_fence_timeline_name(fence),
 			 fence->context,
 			 fence->seqno);
+		dma_fence_access_end();
 	}
 
 	return buf;
@@ -262,6 +264,8 @@ static long sync_file_ioctl_merge(struct sync_file *sync_file,
 static int sync_fill_fence_info(struct dma_fence *fence,
 				 struct sync_fence_info *info)
 {
+	dma_fence_access_begin();
+
 	strscpy(info->obj_name, dma_fence_timeline_name(fence),
 		sizeof(info->obj_name));
 	strscpy(info->driver_name, dma_fence_driver_name(fence),
@@ -273,6 +277,8 @@ static int sync_fill_fence_info(struct dma_fence *fence,
 			ktime_to_ns(dma_fence_timestamp(fence)) :
 			ktime_set(0, 0);
 
+	dma_fence_access_end();
+
 	return info->status;
 }
 
-- 
2.48.0