Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933416AbYCFPzS (ORCPT ); Thu, 6 Mar 2008 10:55:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760335AbYCFPzD (ORCPT ); Thu, 6 Mar 2008 10:55:03 -0500 Received: from terminus.zytor.com ([198.137.202.10]:47555 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756237AbYCFPzB (ORCPT ); Thu, 6 Mar 2008 10:55:01 -0500 Message-ID: <47D012B4.3020104@zytor.com> Date: Thu, 06 Mar 2008 07:50:12 -0800 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: "H.J. Lu" CC: NightStrike , Olivier Galibert , Chris Lattner , Michael Matz , Richard Guenther , Joe Buck , Jan Hubicka , Aurelien Jarno , linux-kernel@vger.kernel.org, gcc@gcc.gnu.org Subject: Re: RELEASE BLOCKER: Linux doesn't follow x86/x86-64 ABI wrt direction flag References: <47CF11D6.7070901@zytor.com> <738B72DB-A1D6-43F8-813A-E49688D05771@apple.com> <2F47E21A-9055-4EC3-99CF-B666BBC045C3@apple.com> <47CF3F09.4080606@zytor.com> <578FCA7D-D7A6-44F6-9310-4A97C13CDCBE@apple.com> <47CF44E7.3020106@zytor.com> <20080306135139.GA5236@dspnet.fr.eu.org> <6dc9ffc80803060743h502fc96bj6117ef87a8555c3a@mail.gmail.com> In-Reply-To: <6dc9ffc80803060743h502fc96bj6117ef87a8555c3a@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1162 Lines: 28 H.J. Lu wrote: > I agree with it. There is no right or wrong here Let's start from > scratch and figure out > what is the best way to handle this, assuming we are defining a new psABI. No, I believe the right way to approach this is by applying the good old-fashioned principle from Ask Mr. Protocol: Be liberal in what you receive, conservative in what you send In other words: a. Fix the kernel. Already in progress. b. Do *not* make gcc assume DF is clean for now. Adding a switch would be a useful thing, since if nothing else it would benefit embedded environments. We might assume DF is clean on 64 bits, since it appears it is rarely used anyway, and 64 bits is more important in the long run. c. Once fixed kernels have been out long enough, we can flip the default of the switch, one platform at a time if need be (e.g. there may never be another SCO OpenServer.) -hpa -- 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/