From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935080AbaLLU1p (ORCPT ); Fri, 12 Dec 2014 15:27:45 -0500 Received: from www.sr71.net ([198.145.64.142]:53734 "EHLO blackbird.sr71.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934871AbaLLU1o (ORCPT ); Fri, 12 Dec 2014 15:27:44 -0500 Message-ID: <548B4FBE.5090101@sr71.net> Date: Fri, 12 Dec 2014 12:27:42 -0800 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Andy Lutomirski , linux-kernel@vger.kernel.org CC: tglx@linutronix.de, x86@kernel.org Subject: Re: [RFC][PATCH 0/8] x86, mpx: Support 32-bit binaries on 64-bit kernels References: <20141212191213.579887D2@viggo.jf.intel.com> <548B4E75.5010507@amacapital.net> In-Reply-To: <548B4E75.5010507@amacapital.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/12/2014 12:22 PM, Andy Lutomirski wrote: > On 12/12/2014 11:12 AM, Dave Hansen wrote: >> This is 3.20 material. I'm hoping to get some comments early >> in case folks have some issues with the way it's being done. >> >> The MPX hardware structures differ in layout in 32 and 64-bit >> mode. A 32-bit binary running on a 64-bit kernel needs the >> 32-bit structures, so we need code which switches between >> the two modes. > > The OS community figured out years ago that you aren't supposed to do > this. Did everyone forget to tell the hardware people? What is your concern with it, exactly? You want the same size structures with the same format for 32-bit and 64-bit modes?