Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384AbYKHMG1 (ORCPT ); Sat, 8 Nov 2008 07:06:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753153AbYKHMGT (ORCPT ); Sat, 8 Nov 2008 07:06:19 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:34629 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753125AbYKHMGT (ORCPT ); Sat, 8 Nov 2008 07:06:19 -0500 Date: Sat, 8 Nov 2008 13:06:01 +0100 From: Ingo Molnar To: Alexey Dobriyan Cc: Andrew Morton , Ken Chen , linux-kernel@vger.kernel.org, Peter Zijlstra Subject: Re: [patch] add /proc/pid/stack to dump task's stack trace Message-ID: <20081108120601.GF8354@elte.hu> References: <20081107074147.GA26607@elte.hu> <20081107075925.GA1825@elte.hu> <20081107082003.GA15800@x200.localdomain> <20081107083249.GD4435@elte.hu> <20081107084943.GA16147@x200.localdomain> <20081107085352.GA27245@elte.hu> <20081107090304.GA30540@elte.hu> <20081107011659.98d3788a.akpm@linux-foundation.org> <20081107092902.GB7787@elte.hu> <20081107175157.GB3469@x200.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081107175157.GB3469@x200.localdomain> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00,DNS_FROM_SECURITYSAGE autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0021] 0.0 DNS_FROM_SECURITYSAGE RBL: Envelope sender in blackholes.securitysage.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 979 Lines: 25 * Alexey Dobriyan wrote: > > 1) only root should be allowed to do this - i.e. file needs to be > > root-owned. > > > > 2) there also needs to be a .config entry for folks to be able to > > turn it off altogether - just like folks can turn off sysrq-t > > dumping via the .config. > > In the name of everything holy, don't add another config option. > It's a _tiny_ piece of code and you have select STACKTRACE via fault > injection, latencytop or lockdep before that. We could make it depend on DEBUG_KERNEL or so, and always select STACKTRACE infrastructure when DEBUG_KERNEL is enabled? There's no reason not to get high quality backtraces via /proc when one debugs the kernel. Ingo -- 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/