From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753949AbZGOKj5 (ORCPT ); Wed, 15 Jul 2009 06:39:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753461AbZGOKj5 (ORCPT ); Wed, 15 Jul 2009 06:39:57 -0400 Received: from mx2.redhat.com ([66.187.237.31]:44862 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753219AbZGOKj4 (ORCPT ); Wed, 15 Jul 2009 06:39:56 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <4A5CFFD8.7020106@t-online.de> References: <4A5CFFD8.7020106@t-online.de> <1247591665-12000-1-git-send-email-vapier@gentoo.org> <20090714161416.GA19147@cmpxchg.org> <6206.1247592126@redhat.com> To: Bernd Schmidt Cc: dhowells@redhat.com, Mike Frysinger , linux-kernel@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, Bryan Wu Subject: Re: [PATCH v2] NOMMU: add support for Memory Protection Units (MPU) Date: Wed, 15 Jul 2009 11:37:35 +0100 Message-ID: <12377.1247654255@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Bernd Schmidt wrote: > No page table, just three bitmaps (r/w/x), with one bit per page, per mm. I presume that all you do is maintain a distinction between userspace-accessible areas and kernel-only areas, and don't prevent userspace processes from destroying each other. David