From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754774Ab1ATUcO (ORCPT ); Thu, 20 Jan 2011 15:32:14 -0500 Received: from smtp6-g21.free.fr ([212.27.42.6]:41781 "EHLO smtp6-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753006Ab1ATUcM (ORCPT ); Thu, 20 Jan 2011 15:32:12 -0500 Message-ID: <4D389BC0.8080900@free.fr> Date: Thu, 20 Jan 2011 21:32:00 +0100 From: matthieu castet User-Agent: Mozilla/5.0 (X11; U; Linux i686; fr; rv:1.8.1.23) Gecko/20090823 SeaMonkey/1.1.18 MIME-Version: 1.0 To: Xiaotian Feng CC: Valdis.Kletnieks@vt.edu, Ingo Molnar , Kees Cook , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-next@vger.kernel.org, Arjan van de Ven , James Morris , Andrew Morton , Andi Kleen , Thomas Gleixner , "H. Peter Anvin" , Rusty Russell , Stephen Rothwell , Dave Jones , Siarhei Liakh , Steven Rostedt Subject: Re: [PATCH 3/3 V13] RO/NX protection for loadable kernel References: <4CE2F914.9070106@free.fr> <24422.1290656467@localhost> <20101126182355.62615dff@mat-laptop> <20101208221951.GO5750@outflux.net> <20101211001857.4c5e0794@mat-laptop> <20101222124019.GG10809@elte.hu> <34428.1293053719@localhost> In-Reply-To: Content-Type: multipart/mixed; boundary="------------050706020502070606060903" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a multi-part message in MIME format. --------------050706020502070606060903 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Xiaotian Feng a écrit : > On Thu, Dec 23, 2010 at 5:35 AM, wrote: >> On Wed, 22 Dec 2010 13:40:19 +0100, Ingo Molnar said: >>> * mat wrote: >>> >>>> Le Wed, 8 Dec 2010 14:19:51 -0800, >>>> Kees Cook a écrit : >>>> >>>>> On Fri, Nov 26, 2010 at 06:23:55PM +0100, mat wrote: >>>>>> could you try the attached patch ? >>>>>> >>>>>> on module load, we sort the __jump_table section. So we should make >>>>>> it writable. >>>>>> >>>>>> >>>>>> Matthieu >>>>>> diff --git a/arch/x86/include/asm/jump_label.h >>>>>> b/arch/x86/include/asm/jump_label.h index f52d42e..574dbc2 100644 >>>>>> --- a/arch/x86/include/asm/jump_label.h >>>>>> +++ b/arch/x86/include/asm/jump_label.h >>>>>> @@ -14,7 +14,7 @@ >>>>>> do >>>>>> { \ asm >>>>>> goto("1:" \ >>>>>> JUMP_LABEL_INITIAL_NOP \ >>>>>> - ".pushsection __jump_table, \"a\" \n\t"\ >>>>>> + ".pushsection __jump_table, \"aw\" \n\t"\ >>>>>> _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \ >>>>>> ".popsection \n\t" \ >>>>>> : : "i" (key) : : label); >>>>>> \ >>>>> Acked-by: Kees Cook >>>>> >>>>> Can this please get committed to tip? >>>> I think it is not need anymore with Steven Rostedt patch [1] >>>> >>>> Matthieu >>>> >>>> [1] >>>>>> Here we set the text read only before we call the notifiers. The >>>>>> function tracer changes the calls to mcount into nops via a notifier >>>>>> call so this must be done after the module notifiers. >>> What's the status of this bug? >>> >>> If we still need the patch then please submit it standalone with a proper subject >>> line, with acks/signoffs added, etc. >> Steve Rostedt's patch that moves the setting of the page permissions seems to >> make this patch no longer necessary. I tripped over this same issue, but the >> version in the latest -mmotm does not need it, as it includes Steve's fix. >> > > I'm facing a boot failure (panic'ed on remove_jump_label_module_init) > on 2.6.37 (latest commit 3c0cb7c), which is 100% reproducible. > With this patch applied, I can boot my machine successfully, so I do > think this patch is needed. > Could you confirm that this patch fix the problem ? Matthieu --------------050706020502070606060903 Content-Type: text/x-diff; name="0001-Fix-jump-table-in-module-init-section.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="0001-Fix-jump-table-in-module-init-section.patch" >>From 0eeba453aaba0ebff86f0a7ad9bfb8afbde0c0dc Mon Sep 17 00:00:00 2001 From: Matthieu CASTET Date: Thu, 20 Jan 2011 21:25:03 +0100 Subject: [PATCH] Fix jump table in module init section If we use jump table in module init, there are marked as removed in __jump_table section after init is done. But we already applied ro permissions on the module, so we can't modify a read only section (crash in remove_jump_label_module_init). Make the __jump_table section rw. Signed-off-by: Matthieu CASTET --- arch/x86/include/asm/jump_label.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index f52d42e..574dbc2 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -14,7 +14,7 @@ do { \ asm goto("1:" \ JUMP_LABEL_INITIAL_NOP \ - ".pushsection __jump_table, \"a\" \n\t"\ + ".pushsection __jump_table, \"aw\" \n\t"\ _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \ ".popsection \n\t" \ : : "i" (key) : : label); \ -- 1.7.2.3 --------------050706020502070606060903--