ipc,shm: shorten critical region for shmctl
ipc,shm: shorten critical region for shmctl

With the *_INFO, *_STAT, IPC_RMID and IPC_SET commands already optimized,
deal with the remaining SHM_LOCK and SHM_UNLOCK commands.  Take the
shm_perm lock after doing the initial auditing and security checks.  The
rest of the logic remains unchanged.

Signed-off-by: Davidlohr Bueso <d7ca2ed3e31360a26e5e60317ed1b792bd41becb@hp.com>
Tested-by: Sedat Dilek <4946ef7dd8f3b21b6f8e2f51ee1d2e36059c35a6@gmail.com>
Cc: Rik van Riel <a21938f5d463ddf41aa718934c205ca2cce8ebbc@redhat.com>
Cc: Manfred Spraul <e4eddfaff1fc5d7affa656f47ee4d83207ccac30@colorfullife.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs