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>
This commit is contained in:
Davidlohr Bueso 2018-07-26 16:37:19 -07:00 committed by Linus Torvalds
parent 15d36fecd0
commit f075faa300

View File

@ -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);