From mboxrd@z Thu Jan  1 00:00:00 1970
From: compudj@krystal.dyndns.org (Mathieu Desnoyers)
Date: Thu, 11 Feb 2010 09:31:06 -0500
Subject: [ltt-dev] kernel panic
In-Reply-To: <4B71AB45.8040804@polymtl.ca>
References: <4B66FE92.7070608@polymtl.ca> <20100201165235.GA12946@Krystal>
	<4B673EC4.3090204@polymtl.ca> <20100202220928.GD656@Krystal>
	<4B698E79.9010803@polymtl.ca> <20100206175514.GA1726@Krystal>
	<4B703231.7080407@polymtl.ca> <20100209181137.GA21812@Krystal>
	<4B71AB45.8040804@polymtl.ca>
Message-ID: <20100211143106.GA31577@Krystal>

* Benjamin Poirier (benjamin.poirier at polymtl.ca) wrote:
> 
 [...]
> kvm -m 512 -drive file=rootFile32,index=0,media=disk,snapshot=on
> -nographic -kernel linux-2.6-lttng/arch/i386/boot/bzImage -append
> "root=/dev/sda1 console=tty0 console=ttyS0,38400 ro"
> 
> vdebian32 login: root
> Password: root
> root at vdebian32:~# while true; do ltt-armall && ltt-disarmall; done
> Connecting /mnt/debugfs/lt[   51.944778] BUG: unable to handle kernel
> NULL pointer dereference at (null)
> [   51.945031] IP: [<c1007258>] add_nops+0x51/0x6b
> [   51.945031] *pde = 00000000
> [   51.945031] Oops: 0000 [#1] SMP
> [   51.945031] LTT NESTING LEVEL : 0

Just found the problem. Commit

commit 8b5a10fc6fd02289ea03480f93382b1a99006142
Author: Jan Beulich <JBeulich at novell.com>
Date:   Wed Aug 19 08:40:48 2009 +0100

from mainline breaks add_nops for lttng in !CONFIG_MODULE configs. Will
fix in the next release. Thanks for providing me an easy way to
reproduce the bug.

Thanks,

Mathieu


-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68