From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763992AbXKTSe5 (ORCPT ); Tue, 20 Nov 2007 13:34:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761814AbXKTS1T (ORCPT ); Tue, 20 Nov 2007 13:27:19 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:51992 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761790AbXKTS1R (ORCPT ); Tue, 20 Nov 2007 13:27:17 -0500 Date: Tue, 20 Nov 2007 10:24:43 -0800 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Huang Ying , Andi Kleen , Ingo Molnar , Thomas Gleixner Subject: [patch 21/29] x86: NX bit handling in change_page_attr() Message-ID: <20071120182443.GW28611@kroah.com> References: <20071120181733.702234406@mini.kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="x86-nx-bit-handling-in-change-page-attr.patch" In-Reply-To: <20071120182248.GA28611@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) X-Bad-Reply: References and In-Reply-To but no 'Re:' in Subject. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 2.6.23-stable review patch. If anyone has any objections, please let us know. ------------------ From: Huang, Ying patch 84e0fdb1754d066dd0a8b257de7299f392d1e727 in mainline. x86: NX bit handling in change_page_attr() This patch fixes a bug of change_page_attr/change_page_attr_addr on Intel x86_64 CPUs. 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 Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86_64/mm/pageattr.c | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86_64/mm/pageattr.c +++ b/arch/x86_64/mm/pageattr.c @@ -148,6 +148,7 @@ __change_page_attr(unsigned long address 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; } --