From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761572AbXILGRR (ORCPT ); Wed, 12 Sep 2007 02:17:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756011AbXILGRF (ORCPT ); Wed, 12 Sep 2007 02:17:05 -0400 Received: from mga03.intel.com ([143.182.124.21]:41701 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755929AbXILGRE (ORCPT ); Wed, 12 Sep 2007 02:17:04 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.20,242,1186383600"; d="scan'208";a="277173608" Subject: Re: [BUGFIX] x86_64: NX bit handling in change_page_attr From: "Huang, Ying" To: Andrew Morton Cc: Andi Kleen , linux-kernel@vger.kernel.org In-Reply-To: <20070911202332.c539f1fe.akpm@linux-foundation.org> References: <1187328518.28497.6.camel@caritas-dev.intel.com> <20070911202332.c539f1fe.akpm@linux-foundation.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 12 Sep 2007 14:18:43 +0800 Message-Id: <1189577923.23838.6.camel@caritas-dev.intel.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 X-OriginalArrivalTime: 12 Sep 2007 06:17:00.0303 (UTC) FILETIME=[875CD1F0:01C7F504] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2007-09-11 at 20:23 -0700, Andrew Morton wrote: > On Fri, 17 Aug 2007 13:28:38 +0800 "Huang, Ying" wrote: > > > This patch fixes a bug of change_page_attr/change_page_attr_addr on > > Intel x86_64 CPU. After changing page attribute to be executable with > > these functions, the page remains un-executable on Intel x86_64 > > CPU. Because on Intel x86_64 CPU, only if the "NX" bits of all four > > level page tables are cleared, the corresponding page is executable > > (refer to section 4.13.2 of Intel 64 and IA-32 Architectures Software > > Developer's Manual). So, the bug is fixed through clearing the "NX" > > bit of PMD when splitting the huge PMD. > > > > Signed-off-by: Huang Ying > > > > --- > > > > Index: linux-2.6.23-rc2-mm2/arch/x86_64/mm/pageattr.c > > =================================================================== > > --- linux-2.6.23-rc2-mm2.orig/arch/x86_64/mm/pageattr.c 2007-08-17 12:50:25.000000000 +0800 > > +++ linux-2.6.23-rc2-mm2/arch/x86_64/mm/pageattr.c 2007-08-17 12:50:48.000000000 +0800 > > @@ -147,6 +147,7 @@ > > split = split_large_page(address, prot, ref_prot2); > > if (!split) > > return -ENOMEM; > > + pgprot_val(ref_prot2) &= ~_PAGE_NX; > > set_pte(kpte, mk_pte(split, ref_prot2)); > > kpte_page = split; > > } > > What happened with this? Still valid? I am waiting for reviewing or merging. And I think it is still valid. Best Regards, Huang Ying