From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1757423Ab0EESOS (ORCPT <rfc822;w@1wt.eu>);
	Wed, 5 May 2010 14:14:18 -0400
Received: from mail-vw0-f46.google.com ([209.85.212.46]:44651 "EHLO
	mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1757352Ab0EESOP convert rfc822-to-8bit (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 5 May 2010 14:14:15 -0400
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :cc:content-type:content-transfer-encoding;
        b=sX4jUHTMSa++LWZUno2WJfx1JvwOvXNW6tJ9ltidlLJ8nrweZMs2vvqzhAe2Cpu7Su
         msYjoiWs4aDeRpvfB7eUijpibY20E2G97+rMiRwULDVZZR2vPpl949kAkapIaPAW2Jkw
         SWRWcfYeeso9pvuQCZHtGFxDAMQNmsblvgPfg=
MIME-Version: 1.0
In-Reply-To: <g2g817ecb6f1004060751s1fd3d42bqc19b5c36b33c3c13@mail.gmail.com>
References: <v2o817ecb6f1003311859nb14bab83y80f743a0accc5028@mail.gmail.com>
	 <1270277000.2686.20.camel@sbs-t61>
	 <g2g817ecb6f1004060751s1fd3d42bqc19b5c36b33c3c13@mail.gmail.com>
Date: Wed, 5 May 2010 14:14:13 -0400
Message-ID: <g2s817ecb6f1005051114kfbf4f33dwf473e0a30e00d614@mail.gmail.com>
Subject: Re: [PATCH 1/4] [tip:x86/mm] Correcting improper large page 
	preservation
From: Siarhei Liakh <sliakh.lkml@gmail.com>
To: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "linux-security-module@vger.kernel.org" 
	<linux-security-module@vger.kernel.org>,
       "linux-next@vger.kernel.org" <linux-next@vger.kernel.org>
Cc: Arjan van de Ven <arjan@infradead.org>, James Morris <jmorris@namei.org>,
       Andrew Morton <akpm@linux-foundation.org>, Andi Kleen <ak@muc.de>,
       Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>,
       Ingo Molnar <mingo@elte.hu>, Rusty Russell <rusty@rustcorp.com.au>,
       Stephen Rothwell <sfr@canb.auug.org.au>, Dave Jones <davej@redhat.com>,
       Suresh Siddha <suresh.b.siddha@intel.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8BIT
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, Apr 6, 2010 at 10:51 AM, Siarhei Liakh <sliakh.lkml@gmail.com> wrote:
> On Sat, Apr 3, 2010 at 2:43 AM, Suresh Siddha <suresh.b.siddha@intel.com> wrote:
>> On Wed, 2010-03-31 at 18:59 -0700, Siarhei Liakh wrote:
>>> +     /*
>>> +      * .data and .bss should always be writable.
>>> +      */
>>> +     if ((within(pfn, __pa((unsigned long)_sdata) >> PAGE_SHIFT,
>>> +                __pa((unsigned long)_edata) >> PAGE_SHIFT)) ||
>>> +         (within(pfn, __pa((unsigned long)__bss_start) >> PAGE_SHIFT,
>>> +                __pa((unsigned long)__bss_stop) >> PAGE_SHIFT))) {
>>> +             pgprot_val(required) |= _PAGE_RW;
>>> +     }
>>
>> I have reviewed this patch and the only comment I have is:
>>
>> On 64bit kernels, kernel text/data mapping and kernel identity mappings
>> are different virtual addresses mapping to same pfn ranges. For the
>> data/bss pages, does it help (in identifying certain data corruptions
>> more easily) in making the kernel identity mapping to be set to
>> read-only and enforce the need of RW only for the kernel data mappings.
>>
>> Or is there some obscure code that uses something like
>> __va(__pa(data_symbol)) and writes to it?
>>
>> If not, we can remove the __pa() constructs above and use the addr for
>> comparisons.
>
> Done.
> Patch V2 have been posted.

Does anyone have  any feedback on the whole kernel RO/NX patch set?
Or should I re-post all 4 patches one more time?

Thank you.