309a5482fa
The atomic exchange operation in drm_syncobj_replace_fence is sufficient for the case where it races with itself. However, if you have a race between a replace_fence and dma_fence_get(syncobj->fence), you may end up with the entire replace_fence happening between the point in time where the one thread gets the syncobj->fence pointer and when it calls dma_fence_get() on it. If this happens, then the reference may be dropped before we get a chance to get a new one. The new helper uses dma_fence_get_rcu_safe to get rid of the race. This is also needed because it allows us to do a bit more than just get a reference in drm_syncobj_fence_get should we wish to do so. v2: - RCU isn't that scary - Call rcu_read_lock/unlock - Don't rename fence to _fence - Make the helper static inline Signed-off-by: Jason Ekstrand <jason@jlekstrand.net> Acked-by: Christian König <christian.koenig@amd.com> (v1) Signed-off-by: Dave Airlie <airlied@redhat.com> |
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| drm | ||
| host1x | ||
| ipu-v3 | ||
| vga | ||
| Makefile | ||