Doing access control checks with rq_lock held can cause deadlock when
audit messages are created (via printk or audit infrastructure) which
trigger a wakeup and deadlock, as noted by both SELinux and SubDomain
folks.  This patch will let the security checks happen w/out lock held,
then re-sample the p->policy in case it was raced. 

Originally from John Johansen <johansen@immunix.com>, reworked by me.
AFAIK, this version drew no objections from Ingo or Andrea. 

From: John Johansen <johansen@immunix.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>