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ipc/sem.c: prevent queue.status tearing in semop

[ Upstream commit f075faa ]

In order for load/store tearing prevention to work, _all_ accesses to
the variable in question need to be done around READ and WRITE_ONCE()
macros.  Ensure everyone does so for q->status variable for
semtimedop().

Link: http://lkml.kernel.org/r/20180717052654.676-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information...
Davidlohr Bueso authored and gregkh committed Jul 26, 2018
1 parent 2dd2f77 commit 92c159863d8afefa9ca25a180feba6bff11c2be5
Showing with 1 addition and 1 deletion.
  1. +1 −1 ipc/sem.c
@@ -2041,7 +2041,7 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops,
}

do {
queue.status = -EINTR;
WRITE_ONCE(queue.status, -EINTR);
queue.sleeper = current;

__set_current_state(TASK_INTERRUPTIBLE);

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