From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757875Ab2GMOoL (ORCPT ); Fri, 13 Jul 2012 10:44:11 -0400 Received: from fias.uni-frankfurt.de ([141.2.248.1]:58650 "EHLO fias.uni-frankfurt.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753807Ab2GMOoJ convert rfc822-to-8bit (ORCPT ); Fri, 13 Jul 2012 10:44:09 -0400 Message-ID: <1342190647.6607.37.camel@blech> Subject: Re: UIO: missing resource mapping From: Dominic Eschweiler To: "Hans J. Koch" Cc: "Michael S. Tsirkin" , Andreas Schallenberg , "linux-kernel@vger.kernel.org" , Greg Kroah-Hartman , kvm@vger.kernel.org Date: Fri, 13 Jul 2012 16:44:07 +0200 In-Reply-To: <20120713141816.GB2554@local> References: <4FFE7C1F.7080702@gmx.net> <20120712194432.GA2592@local> <20120712231632.GC9317@redhat.com> <1342166955.6607.5.camel@blech> <20120713132223.GA10959@redhat.com> <20120713141816.GB2554@local> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3 Content-Transfer-Encoding: 8BIT Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Freitag, den 13.07.2012, 16:18 +0200 schrieb Hans J. Koch: > If somebody maps the card's memory through the UIO driver and somebody > else also maps it using sysfs, that is possible. What happens if both > write to the same hardware registers is a different topic. Writing a > driver implies some responsibility, even if it's done in userspace. That's true and I would not complain. I'm just saying that there is the possibility to disturb a kernel driver by mapping memory etc. I think it is worth to considerate moving the BAR mapping code to UIO. Especially, when I look at the discussions about what effects mappable DMA memory can have on the system security. -- Gruß Dominic