From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932383Ab1LEPKY (ORCPT ); Mon, 5 Dec 2011 10:10:24 -0500 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:45805 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932246Ab1LEPKX (ORCPT ); Mon, 5 Dec 2011 10:10:23 -0500 Date: Mon, 5 Dec 2011 16:10:16 +0100 From: Borislav Petkov To: Ingo Molnar Cc: "H. Peter Anvin" , Thomas Gleixner , "Srivatsa S. Bhat" , LKML , Jan Beulich Subject: Re: [GIT PULL] x86, microcode fixes for 3.2 Message-ID: <20111205151016.GC7834@aftab> References: <20111128204311.GA2814@aftab> <20111202194658.GF15204@aftab> <20111205092612.GB29641@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111205092612.GB29641@elte.hu> 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 Mon, Dec 05, 2011 at 10:26:12AM +0100, Ingo Molnar wrote: > Mind respinning this once more against latest -git? There's a > new conflict due to: > > 8e8da023f5af: x86: Fix boot failures on older AMD CPU's Branch is updated, it also contains the following patch: -- From: Borislav Petkov Date: Mon, 5 Dec 2011 14:28:37 +0100 Subject: [PATCH] x86: Document rdmsr_safe restrictions Recently, I got bitten by using rdmsr_safe too early in the boot process. Document its shortcomings for future reference. Link: http://lkml.kernel.org/r/4ED5B70F.606@lwfinger.net Signed-off-by: Borislav Petkov --- arch/x86/include/asm/msr.h | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index 084ef95..95203d4 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -169,7 +169,14 @@ static inline int wrmsr_safe(unsigned msr, unsigned low, unsigned high) return native_write_msr_safe(msr, low, high); } -/* rdmsr with exception handling */ +/* + * rdmsr with exception handling. + * + * Please note that the exception handling works only after we've + * switched to the "smart" #GP handler in trap_init() which knows about + * exception tables - using this macro earlier than that causes machine + * hangs on boxes which do not implement the @msr in the first argument. + */ #define rdmsr_safe(msr, p1, p2) \ ({ \ int __err; \ -- 1.7.8.rc0 Thanks. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551