From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756162AbXGBTD1 (ORCPT ); Mon, 2 Jul 2007 15:03:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753299AbXGBTDV (ORCPT ); Mon, 2 Jul 2007 15:03:21 -0400 Received: from mx1.redhat.com ([66.187.233.31]:55335 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753187AbXGBTDU (ORCPT ); Mon, 2 Jul 2007 15:03:20 -0400 Message-ID: <46894BE6.1040302@redhat.com> Date: Mon, 02 Jul 2007 15:03:02 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Andy Isaacson CC: Kyle Moffett , Davide Libenzi , Linux Kernel Mailing List Subject: Re: [patch 0/4] MAP_NOZERO v2 - VM_NOZERO/MAP_NOZERO early summer madness References: <20070629193954.GL9157@hexapodia.org> <8F40BE4A-BD38-4C3F-B77D-35661E84C553@mac.com> <20070702190043.GN9157@hexapodia.org> In-Reply-To: <20070702190043.GN9157@hexapodia.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andy Isaacson wrote: > On Sat, Jun 30, 2007 at 08:21:52PM -0400, Kyle Moffett wrote: >> That's why you'd need to call an LSM hook to get a unique identifier, >> as the LSM would actually need to allocate identifiers for >> equivalence classes. Secondly, processes may change labels as they >> run, so you couldn't just call it once and cache the result, you >> would need to call it for every freed page (or every re-use of a page). > > Davide's patch adds a owner_uid field to mm_struct. Assuming that turns > into a "mm security equivalence class identifier", the LSM can simply > update it when a label-change-event occurs. No need to call out to > (potentially heavyweight!) LSM code in page allocation critical paths. > > I'm a bit concerned that tracking the equivalence classes will get > expensive. I think you can end up with quadratic explosion in the worst > case (every user using every permutation of LSM bits). That should not happen. The default SELinux configuration in Fedora (and Debian?) runs a few daemons in their own restricted modes and has most of the system running in unconfined_t, including the majority of user programs. -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic.