From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753845AbXLAMMm (ORCPT ); Sat, 1 Dec 2007 07:12:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752605AbXLAMMe (ORCPT ); Sat, 1 Dec 2007 07:12:34 -0500 Received: from mu-out-0910.google.com ([209.85.134.185]:3850 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752406AbXLAMMd (ORCPT ); Sat, 1 Dec 2007 07:12:33 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=received:date:from:to:cc:subject:message-id:references:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=kU3cmAhtMwI/Q35mEQjCi0D+UYtKV6dXx3mFdfazy3d5316DziX9DrB0qhH8GSZjNGG2CIC62Spv7cqQ+8Bsn3qlcQDIExtozNxAbnigU1Pgys6pfqUTSNpddvPzxbEEVOuhT7mAtWjst7kte9HwZqjWOIkuqZr4fk83foUiikY= Date: Sat, 1 Dec 2007 15:12:20 +0300 From: Cyrill Gorcunov To: Udo van den Heuvel Cc: LKML Subject: Re: possible BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000 Message-ID: <20071201121220.GA28875@cvg> References: <47481590.8090009@xs4all.nl> <200711241951.37817.rjw@sisk.pl> <474870F5.4050504@xs4all.nl> <474C3659.600@xs4all.nl> <20071127164929.GA7279@cvg> <474C56C8.80206@xs4all.nl> <20071127175503.GC7279@cvg> <47513EE5.30703@xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47513EE5.30703@xs4all.nl> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Udo van den Heuvel - Sat, Dec 01, 2007 at 12:00:53PM +0100] | Hallo Cyrill, | | Cyrill Gorcunov wrote: | > | I made a do while loop doing make bzImage modules and a make clean. | > | Should be OK? | > | | > | > well, test the patch enveloped. if the bug is really heppens then | > BUG message should appear. and the thing is much important - does | > that bug appears on the same actions (make bzImage and etc..) on pure | > kernel? or that happened from time to time? | | I only had teh bug once, that was the reason for my post. | Since then the system has been busy, with intervals, doing kernel | compiles and no repeat of the BUG yet... | It's a VIA EN12000 with 1GB of RAM. How could I increase the chances of | hitting it? | | | Kind regards, | Udo | Hi Udo, if my guessing is right - the only chance to hit it faster - is to increase files' activity i.e. compiling the kernel involves a lot of file being readed thru dcache system. First we have to locate the bug on a pure kernel and 'case it's a rare thing to happen... well I don't really know how to get it up to known point. So i think you could play with a pure kernel by compiling it or run several copies of 'grep' thru kernel searching the same pattern like "grep -r -n for ./*" in kernel sources. But Udo, I'm not a kernel specialist so my suggestions could be not really usefull ;) And as only you have found "approximated events" when the bug happend - then we could try the same actions with my latest patch applied to find if it happening exactly in dcache system. (damn, so many *if* there ;) if you will not find that bug being reproducible in a simple way - just leave all as it is, i'm trying to find problems in dcache system by code reading. P.S. Lets CC LKML - that could help us ;) Cyrill