From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752059AbaAONwW (ORCPT ); Wed, 15 Jan 2014 08:52:22 -0500 Received: from mga09.intel.com ([134.134.136.24]:61805 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751664AbaAONwT (ORCPT ); Wed, 15 Jan 2014 08:52:19 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,663,1384329600"; d="scan'208";a="439224207" Message-ID: <52D69291.8080003@linux.intel.com> Date: Wed, 15 Jan 2014 05:52:17 -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: Borislav Petkov , Ingo Molnar CC: "H. Peter Anvin" , linux-kernel@vger.kernel.org, aravind.gopalakrishnan@amd.com, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/urgent] x86, cpu, amd: Add workaround for family 16h, erratum 793 References: <20140114230711.GS29865@pd.tnic> <52D5DC51.9010606@zytor.com> <20140115062817.GA11869@gmail.com> <20140115133619.GA32051@pd.tnic> In-Reply-To: <20140115133619.GA32051@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 01/15/2014 05:36 AM, Borislav Petkov wrote: >> >> msr_read() would essentially map to rdmsr_safe(). Each method has a >> return value that can be checked for failure. > > I'm not sure we want to use the _safe() variants by default as it would > generate the exception tables even in cases where they're clearly not > needed. > It would be particularly silly if what you end up with is in effect to wrap msr_read/write() in a BUG_ON(), which is the effect of the current (trapping) form. There is something to be said for hard errors. -hpa