From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030182AbWGMMtP (ORCPT ); Thu, 13 Jul 2006 08:49:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030185AbWGMMtO (ORCPT ); Thu, 13 Jul 2006 08:49:14 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:37507 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1030182AbWGMMtM (ORCPT ); Thu, 13 Jul 2006 08:49:12 -0400 Date: Thu, 13 Jul 2006 14:43:16 +0200 From: Ingo Molnar To: Andi Kleen Cc: Albert Cahalan , torvalds@osdl.org, alan@lxorguk.ukuu.org.uk, arjan@infradead.org, akpm@osdl.org, linux-kernel@vger.kernel.org, Roland McGrath Subject: Re: utrace vs. ptrace Message-ID: <20060713124316.GA18852@elte.hu> References: <787b0d920607122243g24f5a003p1f004c9a1779f75c@mail.gmail.com> <20060713070445.GA30842@elte.hu> <20060713092432.GA11812@elte.hu> <200607131437.28727.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200607131437.28727.ak@suse.de> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -3.1 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-3.1 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] 0.2 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Andi Kleen wrote: > On Thursday 13 July 2006 11:24, Ingo Molnar wrote: > > * Ingo Molnar wrote: > > > utrace enables something like 'transparent live debugging': an app > > > crashes in your distro, a window pops up, and you can 'hand over' a > > > debugging session to a developer you trust. Or you can instruct the > > > system to generate a coredump. Or you can generate a shorter summary > > > of the crash, sent to a central site. > > > > not to mention that utrace could be used to move most of the ELF > > coredumping code out of the kernel. (the moment you have access to all > > crashed threads userspace can construct its own coredump - instead of > > having the kernel construct a coredump file) Roland's patch does not go > > as far yet, but it could be a possible target. > > I'm not sure that's particularly useful (I think I would prefer to > keep it in kernel), [...] why would we want to keep this in the kernel? Coredumping in the kernel is fragile, and it's nowhere near performance-critical to really live within the kernel. Ingo