From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752329AbdLLKoB convert rfc822-to-8bit (ORCPT ); Tue, 12 Dec 2017 05:44:01 -0500 Received: from prv-mh.provo.novell.com ([137.65.248.74]:42622 "EHLO prv-mh.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752131AbdLLKoA (ORCPT ); Tue, 12 Dec 2017 05:44:00 -0500 Message-Id: <5A2FC0FC0200007800196BA4@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.2 Date: Tue, 12 Dec 2017 03:43:56 -0700 From: "Jan Beulich" To: "Ingo Molnar" Cc: , , "xen-devel" , "Boris Ostrovsky" , "Juergen Gross" , , , Subject: Re: [PATCH 1/2] x86: consider effective protection attributes in W+X check References: <5A2FBC570200007800196B3E@prv-mh.provo.novell.com> <5A2FBE0A0200007800196B4F@prv-mh.provo.novell.com> <20171212103640.qcpyj7wxuimfkvjp@gmail.com> In-Reply-To: <20171212103640.qcpyj7wxuimfkvjp@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> On 12.12.17 at 11:36, wrote: > * Jan Beulich wrote: > >> Using just the leaf page table entry flags would cause a false warning >> in case _PAGE_RW is clear or _PAGE_NX is set in a higher level entry. > > Good find - I assume this bug can cause both false positives and false > negatives > as well, right? Yes, albeit I'm not aware of any outside of Xen (with that other patch applied). Jan