From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752808AbZHKMAn (ORCPT ); Tue, 11 Aug 2009 08:00:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752610AbZHKMAl (ORCPT ); Tue, 11 Aug 2009 08:00:41 -0400 Received: from outbound-dub.frontbridge.com ([213.199.154.16]:33708 "EHLO IE1EHSOBE005.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752783AbZHKMAg convert rfc822-to-8bit (ORCPT ); Tue, 11 Aug 2009 08:00:36 -0400 X-SpamScore: -12 X-BigFish: VPS-12(zz1432R98dNzz1202hzz5a6ciz32i6bh203h43j61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0KO7HQI-04-8LX-01 Date: Tue, 11 Aug 2009 11:44:06 +0200 From: Borislav Petkov To: Kevin Winchester CC: Borislav Petkov , Ingo Molnar , LKML Subject: Re: [PATCH v3] x86: clear incorrectly forced X86_FEATURE_LAHF_LM flag Message-ID: <20090811094406.GA16173@aftab> References: <4A7D673A.1090401@gmail.com> <20090808152016.GB25374@liondog.tnic> <4A7E0797.7060504@gmail.com> <20090810131219.GD21879@aftab> <4A80A5AD.2000209@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline In-Reply-To: <4A80A5AD.2000209@gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-OriginalArrivalTime: 11 Aug 2009 09:44:08.0896 (UTC) FILETIME=[4620DC00:01CA1A68] Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 10, 2009 at 07:56:45PM -0300, Kevin Winchester wrote: > Due to an erratum with certain AMD Athlon 64 processors, the BIOS may > need to force enable the LAHF_LM capability. Unfortunately, in at > least one case, the BIOS does this even for processors that do not > support the functionality. > > Add a specific check that will clear the feature bit for processors > known not to support the LAHF/SAHF instructions. > > Signed-off-by: Kevin Winchester Acked-by: Borislav Petkov -- Regards/Gruss, Boris. Operating | Advanced Micro Devices GmbH System | Karl-Hammerschmidt-Str. 34, 85609 Dornach b. München, Germany Research | Geschäftsführer: Thomas M. McCoy, Giuliano Meroni Center | Sitz: Dornach, Gemeinde Aschheim, Landkreis München (OSRC) | Registergericht München, HRB Nr. 43632