Commit 2b15af6f95 ("af_unix: use freezable blocking calls in read")
converts schedule_timeout() to its freezable version, it was probably
correct at that time, but later, commit 2b514574f7
("net: af_unix: implement splice for stream af_unix sockets") breaks
the strong requirement for a freezable sleep, according to
commit 0f9548ca10:
We shouldn't try_to_freeze if locks are held. Holding a lock can cause a
deadlock if the lock is later acquired in the suspend or hibernate path
(e.g. by dpm). Holding a lock can also cause a deadlock in the case of
cgroup_freezer if a lock is held inside a frozen cgroup that is later
acquired by a process outside that group.
The pipe_lock is still held at that point.
So use freezable version only for the recvmsg call path, avoid impact for
Android.
Fixes: 2b514574f7 ("net: af_unix: implement splice for stream af_unix sockets")
Reported-by: Dmitry Vyukov <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Colin Cross <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Hannes Frederic Sowa <[email protected]>
Signed-off-by: Cong Wang <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
06a77b07e3