From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268669AbUHLTVl (ORCPT ); Thu, 12 Aug 2004 15:21:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268673AbUHLTVk (ORCPT ); Thu, 12 Aug 2004 15:21:40 -0400 Received: from host81-7-2-179.adsl.v21.co.uk ([81.7.2.179]:53469 "EHLO hilly.house") by vger.kernel.org with ESMTP id S268669AbUHLTVd (ORCPT ); Thu, 12 Aug 2004 15:21:33 -0400 Message-ID: <411BC339.30504@vu.a.la> Date: Thu, 12 Aug 2004 20:21:29 +0100 From: Charlie Brej User-Agent: Mozilla Thunderbird 0.7.2 (Windows/20040707) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linux Kernel Mailing List Subject: Reproducable user mode system hang Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I have seem to have found a method to hang the kernel from user mode. The system hangs and does not print an Oops. It still responds to network pings but nothing else. I have successfully crashed the 2.6 kernels on three different machines (all athlon 2.6 kernels): Linux rain.cs.man.ac.uk 2.6.5-1.358 #1 Sat May 8 09:04:50 EDT 2004 i686 athlon i386 GNU/Linux Linux solem.cs.man.ac.uk 2.6.6-1.374 #1 Wed May 19 12:44:14 EDT 2004 i686 athlon i386 GNU/Linux Linux hogshead 2.4.20-8 #1 Thu Mar 13 17:18:24 EST 2003 i686 athlon i386 GNU/Linux This problem does not occur on any 2.4 kernel machines I have tried. Reproducing the problem: Unfortunately the problem occurs in the middle of a program execution and I have been unable to track it down. Download kmd 0.9.19pre1 from (If anyone wants I could distribute my binarys): http://www.cs.man.ac.uk/~brejc8/kmd/dist/KMD-0.9.19.pre1.tar.gz In user mode configure, compile and execute from the source directory: "./kmd -e ./jimulator" In the memory windows in the address box type in "E1000000" and press return. This should now crash the system. Kmd sporns an emulator (jimulator) with which it communicates using stdin/out pipes. I suspect it is a problem in the pipe communication. It occurs even when run under valgrind. I don't know of many methods of narrowing down the search. -- Charlie Brej APT Group, Dept. Computer Science, University of Manchester Web: http://www.cs.man.ac.uk/~brejc8/ Tel: +44 161 275 6844 Mail: IT302, Manchester University, Manchester, M13 9PL, UK