From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758126Ab1EaIIR (ORCPT ); Tue, 31 May 2011 04:08:17 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:33865 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751368Ab1EaIIO (ORCPT ); Tue, 31 May 2011 04:08:14 -0400 Date: Tue, 31 May 2011 10:07:58 +0200 From: Ingo Molnar To: Andrew Lutomirski Cc: Thomas Gleixner , x86@kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Arjan van de Ven , Jan Beulich Subject: Re: [PATCH 0/5] x86-64: Remove syscall instructions at fixed addresses Message-ID: <20110531080758.GA24172@elte.hu> References: <20110529191924.GD9835@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Lutomirski wrote: > On Sun, May 29, 2011 at 3:19 PM, Ingo Molnar wrote: > > Btw., do you know CONFIG_X86_PTDUMP=y and /debug/kernel_page_tables? > > You could use that to double check that after your patches all > > executable (and fixed address) pages are removed [or are harmless]. > > Done. Now there's only one user-executable page and it's mostly harmless. ok. Will test your v3 series. > Maybe I'll try to get rid of vread_tsc and vread_hpet later on to > make it even more harmless. Yeah, that's a good idea. They need pushing into the INT 0xCC do_intcc() handler, that's all that's needed AFAICS - or can you see other complications with them? Thanks, Ingo