From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756741AbbLDW7B (ORCPT ); Fri, 4 Dec 2015 17:59:01 -0500 Received: from terminus.zytor.com ([198.137.202.10]:39152 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754888AbbLDW7A (ORCPT ); Fri, 4 Dec 2015 17:59:00 -0500 User-Agent: K-9 Mail for Android In-Reply-To: <20151204224837.GU21177@pd.tnic> References: <1449018060-1742-3-git-send-email-andi@firstfloor.org> <20151204121115.GA21524@pd.tnic> <20151204182802.GF18534@tassilo.jf.intel.com> <20151204183017.GO21177@pd.tnic> <20151204224837.GU21177@pd.tnic> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Subject: Re: [tip:perf/core] x86, tracing, perf: Add trace point for MSR accesses From: "H. Peter Anvin" Date: Fri, 04 Dec 2015 14:57:57 -0800 To: Borislav Petkov CC: Andi Kleen , Ingo Molnar , linux-tip-commits@vger.kernel.org, vincent.weaver@maine.edu, eranian@google.com, efault@gmx.de, peterz@infradead.org, jolsa@redhat.com, torvalds@linux-foundation.org, tglx@linutronix.de, rostedt@goodmis.org, acme@redhat.com, linux-kernel@vger.kernel.org Message-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On December 4, 2015 2:48:37 PM PST, Borislav Petkov wrote: >On Fri, Dec 04, 2015 at 02:35:38PM -0800, H. Peter Anvin wrote: >> How about this: it is easy too easy to hard code MSR accesses, and >the >> last things we need is alien non-GPL drivers doing their own >low-level >> hacks bypassing these facilities. > >Yeah, that doesn't stop alien, non-GPL drivers from doing > > asm("rdmsr ..) > >Hell, they can even do naked byte opcodes " ...0f 32... " > >But I see your point, thanks! Yes, we can't keep them from being stupid, and they clearly are being so in the first place, but we can at least make it a bit easier to not be. Since it is so easy to do that dumb thing let's not make it harder. -- Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.