Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758514Ab0DHHSO (ORCPT ); Thu, 8 Apr 2010 03:18:14 -0400 Received: from mail.windriver.com ([147.11.1.11]:35555 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758449Ab0DHHSK (ORCPT ); Thu, 8 Apr 2010 03:18:10 -0400 Date: Thu, 8 Apr 2010 15:16:17 +0800 From: Liang Li To: "Rafael J. Wysocki" Cc: Linux Kernel Mailing List , Kernel Testers List , Maciej Rutecki , Amit Shah Subject: Re: [Bug #15615] NULL pointer deref in task_is_waking Message-ID: <20100408071617.GC26543@localhost> Reply-To: Liang Li References: <6Pphclm24fK.A.lSF.qsPvLB@chimera> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-OriginalArrivalTime: 08 Apr 2010 07:17:35.0429 (UTC) FILETIME=[8FF44750:01CAD6EB] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2132 Lines: 63 On Wed, Apr 07, 2010 at 11:13:48PM +0200, Rafael J. Wysocki wrote: > This message has been generated automatically as a part of a summary report > of recent regressions. > > The following bug entry is on the current list of known regressions > from 2.6.33. Please verify if it still should be listed and let the tracking team > know (either way). The bug still there. I just met it. And seems its quite simple to get it fixed. diff --git a/kernel/sched.c b/kernel/sched.c index a3dff1f..2df1a76 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -913,7 +913,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) */ static inline int task_is_waking(struct task_struct *p) { - return unlikely((p->state == TASK_WAKING) && !(p->flags & PF_STARTING)); + return unlikely(p && (p->state == TASK_WAKING) && !(p->flags & PF_STARTING)); } /* But seems commitid 0017d735092844118bef006696a750a0e4ef6ebd in tip tree also touched task_is_waking. So the patch for tip tree should be: diff --git a/kernel/sched.c b/kernel/sched.c index 3acf694..d259641 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -920,7 +920,7 @@ static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) */ static inline int task_is_waking(struct task_struct *p) { - return unlikely(p->state == TASK_WAKING); + return unlikely(p && p->state == TASK_WAKING); } /* Regards, -Liang Li > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=15615 > Subject : NULL pointer deref in task_is_waking > Submitter : Amit Shah > Date : 2010-03-23 04:04 (16 days old) > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/