Commit f075faa3 authored Jul 26, 2018 by Davidlohr Bueso Committed by Linus Torvalds Jul 26, 2018

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

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>

parent 15d36fec

ipc/sem.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2118,7 +2118,7 @@ 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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