From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933085AbaJXMDa (ORCPT ); Fri, 24 Oct 2014 08:03:30 -0400 Received: from mail.skyhub.de ([78.46.96.112]:43879 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932374AbaJXMD2 (ORCPT ); Fri, 24 Oct 2014 08:03:28 -0400 Date: Fri, 24 Oct 2014 14:03:23 +0200 From: Borislav Petkov To: Andy Lutomirski Cc: Ben Harris , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: Don't allow stackprotector without TSC Message-ID: <20141024120323.GA30459@pd.tnic> References: <54499287.5070803@amacapital.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <54499287.5070803@amacapital.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 23, 2014 at 04:43:03PM -0700, Andy Lutomirski wrote: > Presumably the actual failure is a #GP when trying to do the rdtsc. If > so, wouldn't a better fix be to make that rdtsc check cpuid first? Can > we easily check cpuid that early? I don't see why not. The real question, though is, can we have a fallback for RDTSC on those machines so that they don't have to disable stack protector in order to boot. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. --