From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261562AbVFENoq (ORCPT ); Sun, 5 Jun 2005 09:44:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261566AbVFENop (ORCPT ); Sun, 5 Jun 2005 09:44:45 -0400 Received: from imf22aec.mail.bellsouth.net ([205.152.59.70]:5113 "EHLO imf22aec.mail.bellsouth.net") by vger.kernel.org with ESMTP id S261562AbVFENoo (ORCPT ); Sun, 5 Jun 2005 09:44:44 -0400 Message-ID: <007e01c569dc$1d6d2160$2800000a@pc365dualp2> From: To: References: <42A09190.8080703@ccur.com> <20050605112119.GU23831@wotan.suse.de> Subject: Re: [PATCH] ptrace(2) single-stepping into signal handlers Date: Sun, 5 Jun 2005 10:37:29 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1478 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1478 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org ----- Original Message ----- From: "Andi Kleen" To: "John Blackwood" Cc: ; ; ; ; Sent: Sunday, June 05, 2005 07:21 Subject: Re: [PATCH] ptrace(2) single-stepping into signal handlers > On Fri, Jun 03, 2005 at 01:21:20PM -0400, John Blackwood wrote: > > 1. Make the default behavior that we single-step to the next instruction > > in the main (non-signal handler) stream of execution, instead of > > single-stepping into the user's signal handler. > > I think it is better to not change the default behaviour. You risk > breaking programs and there are much more that use ptrace than just gdb. A performance trace profiler would want to step through signal handlers. Sometimes they're an architected norm for a program rather than an abnormal condition handler (ex. Lisp systems routinely handling GP faults on null pointers rather than doing null pointer checks in critical loops)