tree f16f344a3d414db2a0d848b7ca19470b468c902e
parent 92788ac1eb06e69a822de45e2a8a63fa45eb5be2
author Manfred Spraul <manfred@colorfullife.com> 1417564774 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1417628163 -0800

ipc/sem.c: fully initialize sem_array before making it visible

ipc_addid() makes a new ipc identifier visible to everyone.  New objects
start as locked, so that the caller can complete the initialization
after the call.  Within struct sem_array, at least sma->sem_base and
sma->sem_nsems are accessed without any locks, therefore this approach
doesn't work.

Thus: Move the ipc_addid() to the end of the initialization.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reported-by: Rik van Riel <riel@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>