Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753098Ab0BBIRH (ORCPT ); Tue, 2 Feb 2010 03:17:07 -0500 Received: from ernst.netinsight.se ([194.16.221.21]:16700 "HELO ernst.netinsight.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751031Ab0BBIRB (ORCPT ); Tue, 2 Feb 2010 03:17:01 -0500 Date: Tue, 2 Feb 2010 09:16:57 +0100 From: Simon Kagstrom To: ebiederm@xmission.com (Eric W. Biederman) Cc: Andrew Morton , dedekind1@gmail.com, =?ISO-8859-1?Q?Am=E9rico?= Wang , linux-kernel@vger.kernel.org, David Woodhouse , Ingo Molnar Subject: Re: [PATCH] Provide ways of crashing the kernel through debugfs Message-ID: <20100202091657.124e6b0c@marrow.netinsight.se> In-Reply-To: References: <20100126105640.6bf9488c@marrow.netinsight.se> <2375c9f91001260208t31379702tb49cb57d12d5890b@mail.gmail.com> <20100126111853.10890fc6@marrow.netinsight.se> <2375c9f91001261853t1158a66aw86546a61e613338f@mail.gmail.com> <1264689482.1973.132.camel@localhost> <20100129071324.2521705c@marrow.netinsight.se> <20100129023327.021cb23d.akpm@linux-foundation.org> X-Mailer: Claws Mail 3.7.4 (GTK+ 2.16.1; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1894 Lines: 44 On Mon, 01 Feb 2010 20:16:46 -0800 ebiederm@xmission.com (Eric W. Biederman) wrote: > Andrew Morton writes: > > Yes, it's the sort of thing which lots of people have written > > throw-away ad-hoc versions of. It probably makes sense to do it once, > > do it right to save people from having to rererereinvent that wheel. > > > > What do others think? > > I think it makes sense, and in fact we have already merged one attempt > at doing this generically. drivers/misc/lkdtm.c So this functionality was already there - it would appear that I didn't do my research good enough then (I did actually look for this kind of thing). If something, I guess it shows that the kernel source is getting big! To add to the irony, I work for a company that works on "DTM", although it's not related to this functionality :-) > I think Simon's patch adds some additional interesting failure modes. > write_after_free, corrupt_stack_write, unaligned_load_store. > > Simon is there any chance you can change your patch to an enhancement of lkdtm? > > lkdtm actually digs into the interesting failure points with a jprobe > to trigger the harder to reproduce scenarios. Like stack overflow in > an interrupt handler. Yes, this would be a better way of supporting the crash functionality. I'll take a look on integrating the extra tests into lkdtm. I think it would also be good to provide a debugfs interface to lkdtm similar to what provoke-crash has. Right now you have to set it up via module parameters, and for some tests (write_after_free) I think that's a limitation since it often doesn't crash immediately. // Simon -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/