From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <jens.axboe@oracle.com>,
Pekka J Enberg <penberg@cs.helsinki.fi>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Vegard Nossum <vegard.nossum@gmail.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: kmemcheck caught read from freed memory (cfq_free_io_context)
Date: Wed, 2 Apr 2008 03:55:39 -0700 [thread overview]
Message-ID: <20080402105539.GA5610@linux.vnet.ibm.com> (raw)
In-Reply-To: <20080402072846.GA16454@elte.hu>
On Wed, Apr 02, 2008 at 09:28:46AM +0200, Ingo Molnar wrote:
>
> * Jens Axboe <jens.axboe@oracle.com> wrote:
>
> > On Wed, Apr 02 2008, Pekka J Enberg wrote:
> > > On Wed, 2 Apr 2008, Jens Axboe wrote:
> > > > Good catch, I wonder why it didn't complain in my testing. I've added a
> > > > patch to fix that, please see it here:
> > >
> > > You probably don't have kmemcheck in your kernel ;-)
> >
> > Ehm no, you are right :)
>
> ... and you can get kmemcheck by testing on x86.git/latest:
>
> http://people.redhat.com/mingo/x86.git/README
>
> ;-)
I will check this when I get back to some bandwidth -- but in the meantime,
does kmemcheck special-case SLAB_DESTROY_BY_RCU? It is legal to access
newly-freed items in that case, as long as you did rcu_read_lock()
before gaining a reference to them and don't hold the reference past
the matching rcu_read_unlock().
Thanx, Paul
next prev parent reply other threads:[~2008-04-02 10:55 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-04-01 21:08 kmemcheck caught read from freed memory (cfq_free_io_context) Vegard Nossum
2008-04-01 21:36 ` Peter Zijlstra
2008-04-01 22:51 ` Paul E. McKenney
2008-04-02 6:15 ` Peter Zijlstra
2008-04-02 7:19 ` Jens Axboe
2008-04-02 10:24 ` Paul E. McKenney
2008-04-02 7:17 ` Jens Axboe
2008-04-02 7:20 ` Pekka J Enberg
2008-04-02 7:24 ` Jens Axboe
2008-04-02 7:28 ` Ingo Molnar
2008-04-02 7:31 ` Jens Axboe
2008-04-02 10:55 ` Paul E. McKenney [this message]
2008-04-02 10:59 ` Peter Zijlstra
2008-04-02 11:33 ` Fabio Checconi
2008-04-02 11:43 ` Jens Axboe
2008-04-02 12:36 ` Jens Axboe
2008-04-02 12:36 ` Jens Axboe
2008-04-02 12:55 ` Fabio Checconi
2008-04-02 12:58 ` Jens Axboe
2008-04-02 12:58 ` Jens Axboe
2008-04-02 13:16 ` Fabio Checconi
2008-04-02 16:14 ` Paul E. McKenney
2008-04-02 13:37 ` Paul E. McKenney
2008-04-02 13:41 ` Jens Axboe
2008-04-02 15:33 ` Paul E. McKenney
2008-04-02 16:31 ` Jens Axboe
2008-04-02 17:00 ` Paul E. McKenney
2008-04-02 13:32 ` Paul E. McKenney
2008-04-02 13:40 ` Jens Axboe
2008-04-02 16:15 ` Paul E. McKenney
2008-04-02 11:01 ` Pekka Enberg
2008-04-02 11:07 ` Jens Axboe
2008-04-02 11:08 ` Peter Zijlstra
2008-04-02 11:11 ` Pekka Enberg
2008-04-02 11:14 ` Peter Zijlstra
2008-04-02 11:18 ` Pekka Enberg
2008-04-02 17:36 ` Christoph Lameter
2008-04-02 11:14 ` Jens Axboe
2008-04-02 11:20 ` Peter Zijlstra
2008-04-02 11:25 ` Peter Zijlstra
2008-04-02 11:32 ` Jens Axboe
2008-04-02 11:37 ` Peter Zijlstra
2008-04-02 11:42 ` Jens Axboe
2008-04-02 11:47 ` Peter Zijlstra
2008-04-02 11:53 ` Jens Axboe
2008-04-02 12:13 ` Peter Zijlstra
2008-04-02 12:28 ` Jens Axboe
2008-04-02 13:26 ` Paul E. McKenney
2008-04-02 13:43 ` Andi Kleen
2008-04-02 12:26 ` Peter Zijlstra
2008-04-02 12:34 ` Jens Axboe
2008-04-02 16:08 ` Paul E. McKenney
2008-04-02 16:15 ` Vegard Nossum
2008-04-02 16:32 ` Pekka J Enberg
2008-04-02 18:23 ` Paul E. McKenney
2008-04-02 19:53 ` Pekka Enberg
2008-04-02 20:15 ` Paul E. McKenney
2008-04-03 15:18 ` Paul E. McKenney
2008-04-03 19:49 ` Pekka J Enberg
2008-04-03 21:27 ` Paul E. McKenney
2008-04-02 16:59 ` Paul E. McKenney
2008-04-02 17:31 ` Vegard Nossum
2008-04-02 10:40 ` Paul E. McKenney
2008-04-02 10:46 ` Pekka Enberg
2008-04-02 10:49 ` Peter Zijlstra
2008-04-02 10:54 ` Pekka J Enberg
2008-04-02 17:35 ` Christoph Lameter
2008-04-02 10:53 ` Peter Zijlstra
2008-04-02 11:13 ` Jens Axboe
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