From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754755Ab1ACMqr (ORCPT ); Mon, 3 Jan 2011 07:46:47 -0500 Received: from mail-fx0-f46.google.com ([209.85.161.46]:47986 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754306Ab1ACMqq (ORCPT ); Mon, 3 Jan 2011 07:46:46 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=subject:from:to:content-type:date:message-id:mime-version:x-mailer :content-transfer-encoding; b=cGcvi6JUkoUWk4JCc7OZAg6JI/ZgloNYOgYAQ1UMvIi8iCsbl/SxEVSIdN+Kn0pJW8 zl/IjGhKhJ/3/hHYmOY+q0KsyC+IvRCdIMvHzs/dYgCmbw6xxwX/5RGpRZfqr0QfVVzz XDaJcbOPldESJbQw7N98hhpjHiYctIukMFrWM= Subject: Re: [PATCH 3/3 V13] RO/NX protection for loadable kernel From: Tobias Karnat To: "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" Date: Mon, 03 Jan 2011 13:46:42 +0100 Message-ID: <1294058802.19182.28.camel@Tobias-Karnat> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Sure. I can verify that the patch series (a) doesn't break well-behaved > modules and (b) it *does* trigger for misbehaving modules (I sent the > VirtualBox crew a bug report for a module that tried to write to an area > marked executable). This seems to be fixed by VirtualBox 4. I applied the patchset to 2.6.36. ('All in one' patch, http://pastebin.com/raw.php?i=6CDnAkjP ) I have however noticed that after enabling; CONFIG_DEBUG_KERNEL, CONFIG_DEBUG_RODATA and CONFIG_DEBUG_SET_MODULE_RONX there are three "Freeing unused kernel memory" messages, is this correct? Before applying patch: [ 1.449499] Freeing initrd memory: 16328k freed [ 3.336464] Freeing unused kernel memory: 844k freed After applying patch: [ 1.449262] Freeing initrd memory: 16328k freed [ 3.297901] Freeing unused kernel memory: 844k freed [ 3.311849] Write protecting the kernel read-only data: 8192k [ 3.327592] Freeing unused kernel memory: 448k freed [ 3.342651] Freeing unused kernel memory: 276k freed And why does CONFIG_DEBUG_RODATA depend on CONFIG_DEBUG_KERNEL; Isn't it primarily a security enhancement? -Tobias