From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754307Ab1IHFBs (ORCPT ); Thu, 8 Sep 2011 01:01:48 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:64018 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751060Ab1IHFBr convert rfc822-to-8bit (ORCPT ); Thu, 8 Sep 2011 01:01:47 -0400 X-Greylist: delayed 18350 seconds by postgrey-1.27 at vger.kernel.org; Thu, 08 Sep 2011 01:01:47 EDT From: Pedro Alves Organization: CodeSourcery To: Denys Vlasenko Subject: Re: [PATCH v2] Make PTRACE_SEIZE set ptrace options specified in 'data' parameter Date: Thu, 8 Sep 2011 00:55:51 +0100 User-Agent: KMail/1.13.6 (Linux/2.6.38-11-generic; KDE/4.7.0; x86_64; ; ) Cc: Oleg Nesterov , Tejun Heo , linux-kernel@vger.kernel.org, dvlasenk@redhat.com References: <201109072340.31460.vda.linux@googlemail.com> In-Reply-To: <201109072340.31460.vda.linux@googlemail.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Message-Id: <201109080055.52232.pedro@codesourcery.com> X-OriginalArrivalTime: 07 Sep 2011 23:55:54.0750 (UTC) FILETIME=[AE4C11E0:01CC6DB9] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 07 September 2011 22:40:31, Denys Vlasenko wrote: > Make PTRACE_SEIZE set ptrace options specified in 'data' parameter (I wonder if it'd be a good idea to be more future proof and pass in a pointer to a `struct { int my_size; int options; }', so we can add more things in the future other than option bits, if we need to.) > This can be used to close a few corner cases in strace where we get > unwanted racy behavior after attach, but before we have a chance > to set options (the notorious post-execve SIGTRAP comes to mind), (irrespective of the patch being a good idea or not) >>From previous discussions, I understood that PTRACE_SEIZE _always_ disables the post-execve SIGTRAP, so I don't believe that race actually exists. Or is that not the case? -- Pedro Alves