Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760652AbZJMRPr (ORCPT ); Tue, 13 Oct 2009 13:15:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760625AbZJMRPr (ORCPT ); Tue, 13 Oct 2009 13:15:47 -0400 Received: from terminus.zytor.com ([198.137.202.10]:46176 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760612AbZJMRPq (ORCPT ); Tue, 13 Oct 2009 13:15:46 -0400 Message-ID: <4AD4B54C.2060804@zytor.com> Date: Tue, 13 Oct 2009 10:13:48 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Thunderbird/3.0b3 MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Ingo Molnar , Thomas Gleixner , Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List Subject: Re: [GIT PULL] x86: unify sys_iopl References: <4ABD3EC2.1020104@goop.org> <20091013103044.GA3915@elte.hu> <4AD4A9AE.10306@zytor.com> <4AD4B0A0.6050200@goop.org> In-Reply-To: <4AD4B0A0.6050200@goop.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1318 Lines: 33 On 10/13/2009 09:53 AM, Jeremy Fitzhardinge wrote: > On 10/13/09 09:24, H. Peter Anvin wrote: >> First of all, the unification looks good. >> >> As far as .32 is concerned... this *is* a bug even if this is only for >> paravirt, and given the small amount of code I am personally OK with >> taking the whole patch for .32. >> >> However, the patch is not complete! The patch incidentally eliminates >> the need to have assembly stubs for sys_iopl, and those assembly stubs >> should be removed. I have a patch for that currently test building. >> > > I wasn't sure whether task_pt_regs() needed the full register set to be > saved to correctly return rflags (that is, does PTREGSCALL change the > shape of the stack, or just the contents?). > PTREGSCALL does change the shape of the stack on 64 bits, but not on 32 bits. However, I believe it only matters for the additional fields, since the structure is anchored at the top. I will double-check. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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/