From: Oleg Nesterov <oleg@tv-sign.ru>
Date: Wed, 29 Jun 2005 03:44:47 +0000 (-0700)
Subject: [PATCH] ITIMER_REAL: fix possible deadlock and race
X-Git-Tag: v2.6.13-rc1~33
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f01b1b0baa454825ed95c28d2a6a71bbf4510836;p=pandora-kernel.git

[PATCH] ITIMER_REAL: fix possible deadlock and race

As Steven Rostedt pointed out, there are 2 problems with ITIMER_REAL
timers.

1. do_setitimer() does not call del_timer_sync() in case
   when the timer is not pending (it_real_value() returns 0).
   This is wrong, the timer may still be running, and it can
   rearm itself.

2. It calls del_timer_sync() with tsk->sighand->siglock held.
   This is deadlockable, because timer's handler needs this
   lock too.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

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