From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S940214AbXHIOFk (ORCPT ); Thu, 9 Aug 2007 10:05:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S940081AbXHIOFS (ORCPT ); Thu, 9 Aug 2007 10:05:18 -0400 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:53111 "EHLO the-village.bc.nu" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S940052AbXHIOFP (ORCPT ); Thu, 9 Aug 2007 10:05:15 -0400 Date: Thu, 9 Aug 2007 15:12:20 +0100 From: Alan Cox To: =?UTF-8?B?SGFucy1Kw7xyZ2Vu?= Koch Cc: Valdis.Kletnieks@vt.edu, Jesper Juhl , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] UIO: Documentation Message-ID: <20070809151220.3f389efc@the-village.bc.nu> In-Reply-To: <200708091502.45417.hjk@linutronix.de> References: <20070718232332.GA4620@kroah.com> <9a8748490708081436g23c8f01cga585d6612b380f16@mail.gmail.com> <14166.1186611154@turing-police.cc.vt.edu> <200708091502.45417.hjk@linutronix.de> X-Mailer: Claws Mail 2.9.1 (GTK+ 2.10.13; i386-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > That's no UIO invention. Userspace software that uses kernel interfaces like > syscall, device files, sysfs, and so on, is by definition _not_ a derived work > of the kernel and can be distributed under any license. This I believe incorrect. Please cite caselaw if you know better. > With UIO, you have a kernel module that is so small, that even somebody who > hasn't got the hardware can easily review it and tell if the code is OK or not. > It is easy to maintain and doesn't reveal any secrets about the hardware. False Because you have no idea if the interface is correct or the userspace is doing stuff like triggering DMA to arbitary addresses via the interface or mmap functions. If it does so then even if its root only you've blown your security model.