From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755434AbZBKHmO (ORCPT ); Wed, 11 Feb 2009 02:42:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751945AbZBKHl6 (ORCPT ); Wed, 11 Feb 2009 02:41:58 -0500 Received: from hera.kernel.org ([140.211.167.34]:46122 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751398AbZBKHl5 (ORCPT ); Wed, 11 Feb 2009 02:41:57 -0500 Message-ID: <4992812B.1050800@kernel.org> Date: Wed, 11 Feb 2009 16:41:31 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Brian Gerst CC: Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] x86: Pass in pt_regs pointer for syscalls that need it References: <1234277507-4987-1-git-send-email-brgerst@gmail.com> <1234277507-4987-3-git-send-email-brgerst@gmail.com> In-Reply-To: <1234277507-4987-3-git-send-email-brgerst@gmail.com> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Wed, 11 Feb 2009 07:41:45 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Brian. Brian Gerst wrote: > Some syscalls need to access the pt_regs structure, either to copy > user register state or to modifiy it. This patch adds stubs to load > the address of the pt_regs struct into the %eax register, and changes > the syscalls to regparm(1) to receive the pt_regs pointer as the > first argument. Heh... neat. Just one question. > -asmlinkage long sys_iopl(unsigned long regsp) > +ptregscall long sys_iopl(struct pt_regs *regs, unsigned int level) > { > - struct pt_regs *regs = (struct pt_regs *)®sp; > - unsigned int level = regs->bx; Here and at other places where the function takes more than one arguments, wouldn't it be better to just take *regs and use other parameters from regs? That way we won't have to worry about gcc corrupting register frame at all and I think it's cleaner that way. Thanks. -- tejun