tree f12310c2c6492dd7ef4b25dd0c6052f7a114b9cf
parent 20a2078ce7705a6e0722ef5184336eb8657a58d8
author Al Viro <viro@ZenIV.linux.org.uk> 1367537449 +0100
committer Linus Torvalds <torvalds@linux-foundation.org> 1367549491 -0700

ipc: fix GETALL/IPC_RM race for sysv semaphores

We can step on WARN_ON_ONCE() in sem_getref() if a semaphore is removed
just as we are about to call sem_getref() from semctl_main(); results
are not pretty.

We should fail with -EIDRM, same as if IPC_RM happened while we'd been
doing allocation there.  This also expands sem_getref() at its only
callsite (and fixed there), while sem_getref_and_unlock() is simply
killed off - it has no callers at all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>