From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932418Ab3BIPMA (ORCPT ); Sat, 9 Feb 2013 10:12:00 -0500 Received: from co1ehsobe006.messaging.microsoft.com ([216.32.180.189]:34327 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932274Ab3BIPL7 (ORCPT ); Sat, 9 Feb 2013 10:11:59 -0500 X-Forefront-Antispam-Report: CIP:157.56.236.101;KIP:(null);UIP:(null);IPV:NLI;H:BY2PRD0510HT001.namprd05.prod.outlook.com;RD:none;EFVD:NLI X-SpamScore: -3 X-BigFish: PS-3(zz98dI936eI1432Izz1f42h1ee6h1de0h1202h1e76h1d1ah1d2ahzzz2fh2a8h668h839h93fhd24he5bhf0ah1288h12a5h12a9h12bdh137ah13b6h1441h1504h1537h153bh162dh1631h1758h18e1h1946h19b5h1155h) From: Matthew Garrett To: Borislav Petkov CC: Kees Cook , "H. Peter Anvin" , LKML , Thomas Gleixner , Ingo Molnar , "x86@kernel.org" , "linux-efi@vger.kernel.org" , linux-security-module Subject: Re: [PATCH] x86: Lock down MSR writing in secure boot Thread-Topic: [PATCH] x86: Lock down MSR writing in secure boot Thread-Index: AQHOBjA7mQsIMlqU/k+EElzc7Yz1iZhwVXgAgAAAbACAAAawAIAACLcAgAABPICAAAKrAIAAAdKAgAAHwICAABjCAIAAChOAgAAFkwCAACBDAIAAAhCAgABYQICAAC3GgIAAX64A Date: Sat, 9 Feb 2013 15:11:53 +0000 Message-ID: <1360422712.18083.24.camel@x230.lan> References: <1360355671.18083.18.camel@x230.lan> <51157C9C.6030501@zytor.com> <20130208230655.GB28990@pd.tnic> <1360366012.18083.21.camel@x230.lan> <5115A4CC.3080102@zytor.com> <1360373383.18083.23.camel@x230.lan> <20130209092925.GA17728@pd.tnic> In-Reply-To: <20130209092925.GA17728@pd.tnic> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.255.116.4] Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-OriginatorOrg: nebula.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r19FC3va009443 On Sat, 2013-02-09 at 10:29 +0100, Borislav Petkov wrote: > On Fri, Feb 08, 2013 at 10:45:35PM -0800, Kees Cook wrote: > > Also, _reading_ MSRs from userspace arguably has utility that doesn't > > compromise ring-0. > > And to come back to the original question: what is that utility, who > would need it on a secure boot system and why? Things like Turbostat are useful, although perhaps that information should be exposed in a better way. {.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I