Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757872Ab2EGXrP (ORCPT ); Mon, 7 May 2012 19:47:15 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:33828 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757349Ab2EGXrN (ORCPT ); Mon, 7 May 2012 19:47:13 -0400 Message-ID: <4FA85EE5.9030102@fb.com> Date: Mon, 7 May 2012 16:46:45 -0700 From: Arun Sharma User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:11.0) Gecko/20120327 Thunderbird/11.0.1 MIME-Version: 1.0 To: CC: Ingo Molnar , Arnaldo Carvalho de Melo , Frederic Weisbecker , Mike Galbraith , Paul Mackerras , Peter Zijlstra , Stephane Eranian , Namhyung Kim , Tom Zanussi , Subject: Re: [PATCH 1/4] perf, x86: Allow multiple stacks References: <1334961696-19580-1-git-send-email-asharma@fb.com> <1334961696-19580-2-git-send-email-asharma@fb.com> In-Reply-To: <1334961696-19580-2-git-send-email-asharma@fb.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.18.252] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.6.7580,1.0.260,0.0.0000 definitions=2012-05-07_05:2012-05-07,2012-05-07,1970-01-01 signatures=0 X-Proofpoint-Spam-Reason: safe Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 976 Lines: 23 On 4/20/12 3:41 PM, Arun Sharma wrote: > Without this patch, applications with two different stack > regions (eg: native stack vs JIT stack) get truncated > callchains even when RBP chaining is present. GDB shows proper > stack traces and the frame pointer chaining is intact. > > This patch disables the (fp< RSP) check, hoping that other checks > in the code save the day for us. In our limited testing, this > didn't seem to break anything. > > In the long term, we could potentially have userspace advise > the kernel on the range of valid stack addresses, so we don't > spend a lot of time unwinding from bogus addresses. Ingo/Peter: Did you get a chance to look at this patch series (Support multiple stacks v3)? -Arun -- 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/