From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbaAOLLG (ORCPT ); Wed, 15 Jan 2014 06:11:06 -0500 Received: from mail.skyhub.de ([78.46.96.112]:36895 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199AbaAOLLD (ORCPT ); Wed, 15 Jan 2014 06:11:03 -0500 Date: Wed, 15 Jan 2014 12:10:56 +0100 From: Borislav Petkov To: "H. Peter Anvin" Cc: Henrique de Moraes Holschuh , X86 ML , LKML , Kim Naru , Aravind Gopalakrishnan , Sherry Hurwitz Subject: [PATCH -v1.2] x86, CPU, AMD: Add workaround for family 16h, erratum 793 Message-ID: <20140115111056.GB32056@pd.tnic> References: <20140114114133.GA31473@khazad-dum.debian.net> <20140114115547.GA29887@pd.tnic> <52D55468.6000000@zytor.com> <20140114153534.GE29865@pd.tnic> <20140114162722.GF29865@pd.tnic> <52D56627.9060802@zytor.com> <20140114164208.GK29865@pd.tnic> <52D5780E.4070700@zytor.com> <20140114230711.GS29865@pd.tnic> <52D5D883.802@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <52D5D883.802@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 14, 2014 at 04:38:27PM -0800, H. Peter Anvin wrote: > In file included from > /home/hpa/kernel/distwork/arch/x86/include/asm/processor.h:20:0, Finnish! Well, Boris the dumbass forgot to amend, changes were still in the index but not committed. This is what I get when I do a couple of things at the same time. :( --- From: Borislav Petkov This adds the workaround for erratum 793 as a precaution in case not every BIOS implements it. This addresses CVE-2013-6885. Signed-off-by: Borislav Petkov Tested-by: Aravind Gopalakrishnan --- arch/x86/include/uapi/asm/msr-index.h | 1 + arch/x86/kernel/cpu/amd.c | 10 ++++++++++ 2 files changed, 11 insertions(+) diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h index 37813b5ddc37..59cea185ad1d 100644 --- a/arch/x86/include/uapi/asm/msr-index.h +++ b/arch/x86/include/uapi/asm/msr-index.h @@ -184,6 +184,7 @@ #define MSR_AMD64_PATCH_LOADER 0xc0010020 #define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140 #define MSR_AMD64_OSVW_STATUS 0xc0010141 +#define MSR_AMD64_LS_CFG 0xc0011020 #define MSR_AMD64_DC_CFG 0xc0011022 #define MSR_AMD64_BU_CFG2 0xc001102a #define MSR_AMD64_IBSFETCHCTL 0xc0011030 diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 4a48e8bbd857..6ac3a67ad471 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -507,6 +507,16 @@ static void early_init_amd(struct cpuinfo_x86 *c) set_cpu_cap(c, X86_FEATURE_EXTD_APICID); } #endif + + /* F16h erratum 793, CVE-2013-6885 */ + if (c->x86 == 0x16 && c->x86_model <= 0xf) { + u64 val; + + rdmsrl(MSR_AMD64_LS_CFG, val); + if (!(val & BIT(15))) + wrmsrl(MSR_AMD64_LS_CFG, val | BIT(15)); + } + } static const int amd_erratum_383[]; -- 1.8.5.2.192.g7794a68 -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --