From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755706AbYHJOzx (ORCPT ); Sun, 10 Aug 2008 10:55:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753599AbYHJOzp (ORCPT ); Sun, 10 Aug 2008 10:55:45 -0400 Received: from gw.goop.org ([64.81.55.164]:53902 "EHLO mail.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751511AbYHJOzo (ORCPT ); Sun, 10 Aug 2008 10:55:44 -0400 Message-ID: <489F015E.9080704@goop.org> Date: Sun, 10 Aug 2008 07:55:26 -0700 From: Jeremy Fitzhardinge User-Agent: Thunderbird 2.0.0.16 (X11/20080723) MIME-Version: 1.0 To: Dave Hansen CC: Oren Laadan , Arnd Bergmann , containers@lists.linux-foundation.org, Theodore Tso , linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 2/4] checkpoint/restart: x86 support References: <20080807224033.FFB3A2C1@kernel> <200808081409.30591.arnd@arndb.de> <489CAC70.7090809@cs.columbia.edu> <200808090029.28286.arnd@arndb.de> <489CD0F9.9060603@cs.columbia.edu> <1218242286.19082.62.camel@nimitz> In-Reply-To: <1218242286.19082.62.camel@nimitz> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dave Hansen wrote: > On Fri, 2008-08-08 at 19:04 -0400, Oren Laadan wrote: > >>> struct pt_regs is part of the kernel ABI, it will not change. >>> >> I'm in favor about keeping the format identical between the variations of >> each architecture. Note, however, that "struct pt_regs" won't do because it >> may change with these variations. >> > > "Part of the kernel ABI" makes it sound to me like it won't change. > Who's right here? :) Struct pt_regs is not ABI, and can (and has) changed on x86. It's not suitable for a checkpoint structure because it only contains the registers that the kernel trashes, not all usermode registers (on i386, it leaves out %gs, for example). asm-x86/ptrace-abi.h does define stuff that's fixed in stone; it expresses it in terms of a register array, with constants defining what element is which register. J