android: unconditionally remove callbacks in sync_fence_free()
PATCH 1/1 android: unconditionally remove callbacks in sync_fence_free()
Using fence->status to determine whether or not there are callbacks remaining on the sync_fence is racy since fence->status may have been decremented to 0 on another CPU before fence_check_cb_func() has completed. By unconditionally calling fence_remove_callback() for each fence in the sync_fence, we guarantee that each callback has either completed (since fence_remove_callback() grabs the fence lock) or been removed.
Signed-off-by Andrew Bresticker <[email protected]>
Signed-off-by Dmitry Torokhov <[email protected]>
--- drivers/staging/android/sync.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
drivers/staging/android/sync.c +2 -4
@@ -527,12 +527,10 @@ static const struct fence_ops android_fence_ops = {static void sync_fence_free (struct kref *kref) { struct sync_fence *fence = container_of(kref, struct sync_fence, kref); -int i, status =atomic_read (&fence->status); +int i;for (i =0 ; i < fence->num_fences; ++i) { -if (status) -fence_remove_callback (fence->cbs[i].sync_pt, - &fence->cbs[i].cb); +fence_remove_callback (fence->cbs[i].sync_pt, &fence->cbs[i].cb);fence_put (fence->cbs[i].sync_pt); }
Signature · 5 lines
2.6.0.rc2.230.g3dd15c0 -- Dmitry