From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263898AbUBKJwh (ORCPT ); Wed, 11 Feb 2004 04:52:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263953AbUBKJwh (ORCPT ); Wed, 11 Feb 2004 04:52:37 -0500 Received: from hermine.idb.hist.no ([158.38.50.15]:26643 "HELO hermine.idb.hist.no") by vger.kernel.org with SMTP id S263898AbUBKJwg (ORCPT ); Wed, 11 Feb 2004 04:52:36 -0500 Message-ID: <4029FE68.9020206@aitel.hist.no> Date: Wed, 11 Feb 2004 11:05:28 +0100 From: Helge Hafting Organization: AITeL, HiST User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20031107 Debian/1.5-3 X-Accept-Language: no, en MIME-Version: 1.0 To: Matthew Reppert CC: Mike Bell , linux-kernel@vger.kernel.org Subject: Re: devfs vs udev, thoughts from a devfs user References: <20040210113417.GD4421@tinyvaio.nome.ca> <20040210170157.GA27421@kroah.com> <20040210171337.GK4421@tinyvaio.nome.ca> <20040210172552.GB27779@kroah.com> <20040210174603.GL4421@tinyvaio.nome.ca> <20040210181242.GH28111@kroah.com> <20040210182943.GO4421@tinyvaio.nome.ca> <1076451567.21725.21.camel@minerva> In-Reply-To: <1076451567.21725.21.camel@minerva> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Matthew Reppert wrote: > At the very least, sysfs' and devfs' approaches to devices differ in > philosophy. devfs says "here's a device node, you can tell where it is > in the bus hierarchy by looking at its filename". sysfs, on the other > hand, says "here's the device hierarchy", and gives you enough information > to create device nodes for each point in the hierarchy if you wish to do > so. > There's an interesting security implication here. I used to think "why don't they make a device node instead of exporting numbers, udev could then simply make a link to it" It'd be simpler, and the minimalists could use the node in sysf directly. The security advantage is that we don't get a device with some default permissions that might get abused. The udev config can decide to create a node with stricter than usual permissions, or decide to not make the node at all. Helge Hafting