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From: Manfred Spraul <manfred@colorfullife.com>
To: Nadia Derbey <Nadia.Derbey@bull.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	cboulte@gmail.com, linux-kernel@vger.kernel.org,
	Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH] SYSVIPC - Fix the ipc structures initialization
Date: Thu, 13 Nov 2008 18:53:57 +0100	[thread overview]
Message-ID: <491C69B5.100@colorfullife.com> (raw)
In-Reply-To: <1226570880.2585.41.camel@frecb000730.frec.bull.fr>

Nadia Derbey wrote:
> That's what the patch I sent at the beginning of this thread
> (http://lkml.org/lkml/2008/10/28/177) fixes: the ipc structure is not
> completely initialized before being inserted in the tree.
>
> The patched kernel has been running for 4 days on my victim without any
> problem, but Clement is still facing a problem (that comes later).
>
> I think this patch should be included anyways, because ipc structures
> initialization is not correct the way it is done today.
>
>   
Definitively: Your patch belongs into 2.6.28 and the next 2.6.27.

> I'm still reviewing the code to see what else could be wrong.
>   
I started looking into the idr code: perhaps idr returns a stale entry? 
A race somewhere in the RCU code.
I.e. the new bug is not corruption due to access before 
spin_lock_init(), but due to access after kfree()?

Clement: Could you send us an ipcs output from before the test?
Do you have any sysv msg queues on your system?
And: Do you use PREEMPT, do you use PREEMPT_RCU?

If there are no message queues around, then every msgget()/IPC_RMID will 
create a new idr layer/tear the layer down again.

--
    Manfred

      reply	other threads:[~2008-11-13 17:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20081028145952.620752409@bull.net>
2008-10-28 14:59 ` Nadia.Derbey
2008-10-28 17:22   ` Manfred Spraul
2008-10-29  9:11   ` cboulte
2008-11-11 22:16     ` Andrew Morton
2008-11-12  6:41       ` Manfred Spraul
2008-11-13  6:10       ` Manfred Spraul
2008-11-13  8:06         ` Peter Zijlstra
2008-11-13 10:08         ` Nadia Derbey
2008-11-13 17:53           ` Manfred Spraul [this message]

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