Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755954AbaAJCOK (ORCPT ); Thu, 9 Jan 2014 21:14:10 -0500 Received: from terminus.zytor.com ([198.137.202.10]:36240 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753435AbaAJCOI (ORCPT ); Thu, 9 Jan 2014 21:14:08 -0500 Message-ID: <52CF573F.8030300@zytor.com> Date: Thu, 09 Jan 2014 18:13:19 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Linus Torvalds , Borislav Petkov CC: halfdog , Konrad Rzeszutek Wilk , Thomas Gleixner , Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List , Ben Hutchings Subject: Re: Sanitize CPU-state when switching tasks (was sanitize CPU-state when switching from virtual-8086 mode to other task) References: <52C0C9F4.50101@zytor.com> <52C196C3.1040300@halfdog.net> <52C31027.2030101@zytor.com> <20131231192106.GA22535@phenom.dumpdata.com> <52C347F0.8070902@zytor.com> <52CD022E.9040107@halfdog.net> <52CD8E10.3010204@zytor.com> <20140108193655.GD5098@pd.tnic> <52CDC316.4050503@halfdog.net> <52CDD3AE.4030301@zytor.com> <20140109225815.GI11594@pd.tnic> In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/09/2014 04:42 PM, Linus Torvalds wrote: > On Fri, Jan 10, 2014 at 6:58 AM, Borislav Petkov wrote: >> >> Ok, I was able to reproduce > > Looking at this, I think this is just a bug in our > restore_fpu_checking() hackery for X86_FEATURE_FXSAVE_LEAK.. > > Which also explains why it only triggers on E-350 - it's only relevant > for those K7/K8 CPU's that use this. > > Maybe just add a fcnlex to before the emms? Something like this > (TOTALLY UNTESTED!!) attached patch. > OK, that sounds very reasonable. Boris, halfdog, does something like this resolve your problem? -hpa -- 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/