Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752807AbZIZAWZ (ORCPT ); Fri, 25 Sep 2009 20:22:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752664AbZIZAWZ (ORCPT ); Fri, 25 Sep 2009 20:22:25 -0400 Received: from claw.goop.org ([74.207.240.146]:58147 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbZIZAWY (ORCPT ); Fri, 25 Sep 2009 20:22:24 -0400 Message-ID: <4ABD5EC3.5040204@goop.org> Date: Fri, 25 Sep 2009 17:22:27 -0700 From: Jeremy Fitzhardinge 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 Lightning/1.0pre Thunderbird/3.0b3 MIME-Version: 1.0 To: Brian Gerst CC: Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List Subject: Re: [GIT PULL] x86: unify sys_iopl References: <4ABD3EC2.1020104@goop.org> <73c1f2160909251556g40f3c5b1o1c29b7f012912873@mail.gmail.com> <4ABD50A5.5000309@goop.org> <73c1f2160909251654v1c9f8eb9k9211f1e0c5e15f67@mail.gmail.com> In-Reply-To: <73c1f2160909251654v1c9f8eb9k9211f1e0c5e15f67@mail.gmail.com> X-Enigmail-Version: 0.97a 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: 1017 Lines: 25 On 09/25/09 16:54, Brian Gerst wrote: > Using task_pt_regs is less effecient than getting the pointer directly > from the syscall entry code. (really not an issue in this case) > On 32-bit it probably doesn't matter too > much, but on 64-bit, you still need the special stub code in > entry_64.S to put the full pt_regs struct on the stack. Changing the > calling conventions should be a seperate patch, and should be done for > all pt_regs-using syscalls. > iopl only really cares about [er]flags, so it probably doesn't need a full ptregs structure anyway. But I'm not sure what changes you'd consider for the rest of the ptregs calls; sigaltstack probably doesn't need full ptregs either (it just updates [er]sp I think), but fork/clone definitely do. J -- 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/