Commit 7b72d3ba authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by DidntRead
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android: unconditionally remove callbacks in sync_fence_free() 



[ Upstream commit 699f685569434510d944e419f4048c4e3ba8d631 ]

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: default avatarAndrew Bresticker <abrestic@chromium.org>
Signed-off-by: default avatarDmitry Torokhov <dtor@chromium.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent ab985cb3

drivers/staging/android/sync.c

+2 −2
Original line number Diff line number Diff line
@@ -531,10 +531,10 @@ 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; // Google Patch 4f4f7cc

	int i;



	for (i = 0; i < fence->num_fences; ++i) {

		fence_remove_callback(fence->cbs[i].sync_pt, &fence->cbs[i].cb); // Google Patch 4f4f7cc

		fence_remove_callback(fence->cbs[i].sync_pt, &fence->cbs[i].cb);

		fence_put(fence->cbs[i].sync_pt);

	}