From: Christoph Lameter <cl@linux.com>
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: [RFC][PATCH] fix move/migrate_pages() race on task struct
Date: Fri, 24 Feb 2012 10:54:15 -0600 (CST) [thread overview]
Message-ID: <alpine.DEB.2.00.1202241053220.3726@router.home> (raw)
In-Reply-To: <4F47BF56.6010602@linux.vnet.ibm.com>
On Fri, 24 Feb 2012, Dave Hansen wrote:
> On 02/24/2012 07:20 AM, Christoph Lameter wrote:
> > Subject: migration: Do not do rcu_read_unlock until the last time we need the task_struct pointer
> >
> > Migration functions perform the rcu_read_unlock too early. As a result the
> > task pointed to may change. Bugs were introduced when adding security checks
> > because rcu_unlock/lock sequences were inserted. Plus the security checks
> > and do_move_pages used the task_struct pointer after rcu_unlock.
> >
> > Fix those issues by removing the unlock/lock sequences and moving the
> > rcu_read_unlock after the last use of the task struct pointer.
> >
> > Signed-off-by: Christoph Lameter <cl@linux.com>
>
> It doesn't fix the code duplication, but it definitely does fix the bug
Yes I did not want to override all your good work.
Could you do another patch that removed the duplication?
next prev parent reply other threads:[~2012-02-24 16:54 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-23 18:07 [RFC][PATCH] fix move/migrate_pages() race on task struct Dave Hansen
2012-02-23 18:45 ` Andi Kleen
2012-02-23 18:45 ` Christoph Lameter
2012-02-23 19:10 ` Dave Hansen
2012-02-23 19:40 ` Christoph Lameter
2012-02-23 20:04 ` Dave Hansen
2012-02-23 21:41 ` Christoph Lameter
2012-02-24 3:14 ` Eric W. Biederman
2012-02-24 15:20 ` Christoph Lameter
2012-02-24 15:41 ` Eric W. Biederman
2012-02-24 16:48 ` Dave Hansen
2012-02-24 16:54 ` Christoph Lameter [this message]
2012-02-24 17:04 ` Dave Hansen
2012-02-24 17:08 ` Christoph Lameter
2012-02-24 17:25 ` Dave Hansen
2012-02-24 17:32 ` Christoph Lameter
2012-02-24 21:37 ` Dave Hansen
2012-02-24 23:12 ` Eric W. Biederman
2012-02-27 16:43 ` Christoph Lameter
2012-02-25 12:13 ` Eric W. Biederman
2012-02-27 19:01 ` Christoph Lameter
2012-02-27 20:15 ` Eric W. Biederman
2012-02-27 22:39 ` Christoph Lameter
2012-02-28 19:30 ` Christoph Lameter
2012-02-29 20:31 ` Andrew Morton
2012-02-29 20:33 ` Christoph Lameter
2012-02-29 20:36 ` Dave Hansen
2012-02-24 17:07 ` KOSAKI Motohiro
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