From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753613Ab1BCVwr (ORCPT ); Thu, 3 Feb 2011 16:52:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:9050 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750888Ab1BCVwq (ORCPT ); Thu, 3 Feb 2011 16:52:46 -0500 Date: Thu, 3 Feb 2011 22:44:50 +0100 From: Oleg Nesterov To: Roland McGrath Cc: Tejun Heo , jan.kratochvil@redhat.com, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org Subject: Re: [PATCH 1/1] ptrace: make sure do_wait() won't hang after PTRACE_ATTACH Message-ID: <20110203214450.GA29496@redhat.com> References: <1296227324-25295-1-git-send-email-tj@kernel.org> <1296227324-25295-11-git-send-email-tj@kernel.org> <20110203204122.GA26371@redhat.com> <20110203204154.GB26371@redhat.com> <20110203213640.1F516180995@magilla.sf.frob.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110203213640.1F516180995@magilla.sf.frob.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/03, Roland McGrath wrote: > > IMHO this sort of band-aid does not really help the overall situation. > It takes something that is intricate and fiddly and just fiddles it a > bit more. Userland will still have to handle older kernels where this > behavior is not there. If userland does anything that relies on this > new behavior, then it will have to try somehow to figure out which > kernel versions have which behavior and adapt, etc. Absolutely agreed. As I said, I am not sure this patch makes sense. I only sent it because I have to react to the bug report. > When the old behaviors are unhelpful like this, I think it is really > better to add new mechanisms instead. Agreed! Can't resist, let me repeat... imho ptrace is unfixable ;) OK, please ignore this patch. Oleg.