Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755974Ab2B2Upz (ORCPT ); Wed, 29 Feb 2012 15:45:55 -0500 Received: from tx2ehsobe001.messaging.microsoft.com ([65.55.88.11]:30046 "EHLO TX2EHSOBE001.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755749Ab2B2Upx (ORCPT ); Wed, 29 Feb 2012 15:45:53 -0500 X-SpamScore: -11 X-BigFish: VPS-11(zzbb2dI9371I1432N98dKzz1202hzz8275bhz2fh668h839h93fh) X-Forefront-Antispam-Report: CIP:160.33.98.74;KIP:(null);UIP:(null);IPV:NLI;H:mail7.fw-bc.sony.com;RD:mail7.fw-bc.sony.com;EFVD:NLI Message-ID: <4F4E8E6A.2020601@am.sony.com> Date: Wed, 29 Feb 2012 12:45:30 -0800 From: Tim Bird User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.12) Gecko/20100907 Fedora/3.0.7-1.fc12 Thunderbird/3.0.7 MIME-Version: 1.0 To: Andi Kleen CC: Oleg Nesterov , Denys Vlasenko , linux kernel Subject: Re: Questions about ptrace on a dying process References: <4F4E6915.1010209@am.sony.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-OriginatorOrg: am.sony.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1587 Lines: 39 On 02/29/2012 11:12 AM, Andi Kleen wrote: > Tim Bird writes: > >> ptrace maintainers (and interested parties)... >> >> I'm working on a crash handler for Linux, which uses ptrace to retrieve information >> about a process during it's coredump. Specifically, from within a core handler >> program (started within do_coredump() as a user_mode_helper), I would like to make >> ptrace calls against the dying process. > > The standard approach is to define a core pipe handler and parse the > elf memory dump. Yeah - I may be doing something new here. Android uses ptrace in debuggerd, which is their crash reporting tool, but they wake it up with signals before the dying program goes into coredump. I'm taking a different approach and trying to do initiated by the coredump feature in Linux. This makes it so that a process does not need to be persistently running to capture these events. This is on embedded systems, where the dump is not saved. The dump is available via stdin to the core pipe handler, but it would be kind of a pain to wrapper that for random access, which is needed for stuff like stack unwinding. -- Tim ============================= Tim Bird Architecture Group Chair, CE Workgroup of the Linux Foundation Senior Staff Engineer, Sony Network Entertainment ============================= -- 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/