From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932093AbbJUIJ4 (ORCPT ); Wed, 21 Oct 2015 04:09:56 -0400 Received: from terminus.zytor.com ([198.137.202.10]:40420 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753719AbbJUIJr (ORCPT ); Wed, 21 Oct 2015 04:09:47 -0400 Subject: Re: [PATCH] x86: Kill some chicken bits To: Borislav Petkov References: <1445358810-12800-1-git-send-email-bp@alien8.de> <90D1893E-1143-4B81-B849-74EB8B27574F@zytor.com> <20151020170457.GF31130@pd.tnic> Cc: X86 ML , LKML From: "H. Peter Anvin" Message-ID: <56274828.6020909@zytor.com> Date: Wed, 21 Oct 2015 01:09:12 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151020170457.GF31130@pd.tnic> 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 10/20/2015 10:04 AM, Borislav Petkov wrote: > On Tue, Oct 20, 2015 at 09:58:18AM -0700, H. Peter Anvin wrote: >> I would like to keep nosmap until SMAP hardware is more ubiquitous >> since SMAP is vulnerable to kernel bugs. We have already had a case >> where a maintainer pushed "cleanup" code straight to Linus, bypassing >> the x86 maintainers, which broke booting on SMAP hardware. > > Right, so the thought came to my mind while going through those, that we > don't really know what they're going to be good for and what we're going > to need them for in the future. So maybe we want to keep them after all > - you never know. > > For example, luto made me use "nosep" recently even though that's an > ancient chicken bit. > > So maybe we want to not remove them ever - the cleanup win is not that > great to even care... > Some chicken bits may be better than others, though. -hpa