Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757089Ab2BXPTj (ORCPT ); Fri, 24 Feb 2012 10:19:39 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:56372 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753982Ab2BXPTh (ORCPT ); Fri, 24 Feb 2012 10:19:37 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of jidong.xiao@gmail.com designates 10.216.134.39 as permitted sender) smtp.mail=jidong.xiao@gmail.com; dkim=pass header.i=jidong.xiao@gmail.com MIME-Version: 1.0 In-Reply-To: References: Date: Fri, 24 Feb 2012 10:19:36 -0500 Message-ID: Subject: Re: Can we move device drivers into user-space? From: Jidong Xiao To: Kernel development list Cc: Greg KH Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1938 Lines: 43 On Wed, Feb 22, 2012 at 11:56 PM, Jidong Xiao wrote: > Hi, > > I am just curious. Since the concept user-space device drivers has > been proposed for several years, and some related projects and > research papers have demonstrated the feasibility of of moving device > drivers into use space. In particular, this paper: > > Tolerating Malicious Device Drivers in Linux. > http://pdos.csail.mit.edu/papers/sud:usenix10.pdf > > In this paper, existing device driver code need not to be changed, > which should help the idea to be applied in practice. > > The advantage and disadvantage of move device drivers into use space > of both obvious: > > Advantage: Since most of kernel bugs are caused by device drivers > issues, moving device drivers into user space can reduce the impact of > device driver bugs. From security perspective, the system can be more > secure and robust if most device drivers are working in user space. > Disadvantage: At least, existing techniques as well as the above paper > showed a relatively high overhead. > > So is it mainly because the high overhead that prevents the user-space > device drivers ideas being accepted in Linux? > Actually, my major concern is, since UIO has been accepted, then why don't we move all the rest device drivers into user space as well. As I understand, currently, some of device drivers are running on user space, while the other (or say the majority of) device drivers are running on kernel space, so why don't we maintain a consistent device drivers infrastructure, say, either all in user space, or all in kernel space. (Sure some critical device drivers still need to be kept in kernel space.) -Jidong -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/