From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756510AbbE2Pb6 (ORCPT <rfc822;w@1wt.eu>);
	Fri, 29 May 2015 11:31:58 -0400
Received: from www.sr71.net ([198.145.64.142]:53311 "EHLO blackbird.sr71.net"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1756045AbbE2Pb4 (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Fri, 29 May 2015 11:31:56 -0400
Message-ID: <55688669.5090701@sr71.net>
Date: Fri, 29 May 2015 08:31:53 -0700
From: Dave Hansen <dave@sr71.net>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0
MIME-Version: 1.0
To: Andy Lutomirski <luto@amacapital.net>
CC: Ingo Molnar <mingo@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        X86 ML <x86@kernel.org>, Thomas Gleixner <tglx@linutronix.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Oleg Nesterov <oleg@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Rik van Riel <riel@redhat.com>, Suresh Siddha <sbsiddha@gmail.com>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH 02/19] x86, fpu: Wrap get_xsave_addr() to make it safer
References: <20150527183609.964CC3BA@viggo.jf.intel.com> <20150527183610.56178C96@viggo.jf.intel.com> <20150528084140.GA31719@gmail.com> <556729FE.1020007@sr71.net> <20150528150114.GA10146@gmail.com> <55674157.4070108@sr71.net> <CALCETrV0h+i+PiBTW7ssQ7Hmn9+r97AK4TyauXd5qApHBcfgpA@mail.gmail.com>
In-Reply-To: <CALCETrV0h+i+PiBTW7ssQ7Hmn9+r97AK4TyauXd5qApHBcfgpA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 05/28/2015 06:05 PM, Andy Lutomirski wrote:
> I would propose that we take the opposite approach and just ban
> eagerfpu=off when MPX is enabled.  We could then take the next step
> and default eagerfpu=on for everyone and, if nothing breaks, then just
> delete lazy mode entirely.

No objections from me on this.

It's definitely the simplest thing to do, and it's one less potential
delta that enabling MPX could impose on someone, so it makes me happy on
that front.