From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753384AbaI2UB7 (ORCPT ); Mon, 29 Sep 2014 16:01:59 -0400 Received: from terminus.zytor.com ([198.137.202.10]:41619 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751028AbaI2UB6 (ORCPT ); Mon, 29 Sep 2014 16:01:58 -0400 Message-ID: <5429BAA7.8060406@zytor.com> Date: Mon, 29 Sep 2014 13:01:43 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 MIME-Version: 1.0 To: Thomas Gleixner CC: Andy Lutomirski , Anish Bhatt , "linux-kernel@vger.kernel.org" , X86 ML , Ingo Molnar , Sebastian Lackner Subject: Re: [PATCH] x86 : Ensure X86_FLAGS_NT is cleared on syscall entry References: <1411674171-24442-1-git-send-email-anish@chelsio.com> <54299979.6080705@amacapital.net> <5429B664.4060003@zytor.com> In-Reply-To: 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 On 09/29/2014 12:57 PM, Thomas Gleixner wrote: > >> I think we should mask the bit anyway. > > I tend to disagree. If we clear it there we need to consequentely > audit ALL other possibilites and if there are any we need to clear the > bit there as well. Just to make buggy user space happy? > The entry options into the kernel are: interrupt/exception (already known to be OK), SYSENTER32, SYSCALL32, and SYSCALL64. It is not too much to work through those issues, I don't think. -hpa