From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 3 Jul 2001 10:52:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 3 Jul 2001 10:51:50 -0400 Received: from perninha.conectiva.com.br ([200.250.58.156]:2830 "HELO perninha.conectiva.com.br") by vger.kernel.org with SMTP id ; Tue, 3 Jul 2001 10:51:30 -0400 Date: Tue, 3 Jul 2001 11:51:18 -0300 From: Arnaldo Carvalho de Melo To: Guillaume Lancelin Cc: linux-kernel@vger.kernel.org Subject: Re: Memory access Message-ID: <20010703115118.B1616@conectiva.com.br> Mail-Followup-To: Arnaldo Carvalho de Melo , Guillaume Lancelin , linux-kernel@vger.kernel.org In-Reply-To: <20010703144532.11007.qmail@web4201.mail.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.17i In-Reply-To: <20010703144532.11007.qmail@web4201.mail.yahoo.com>; from guillaumelancelin@yahoo.es on Tue, Jul 03, 2001 at 04:45:32PM +0200 X-Url: http://advogato.org/person/acme Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Jul 03, 2001 at 04:45:32PM +0200, Guillaume Lancelin escreveu: > Writing a device driver for a IO card, I have the following message from > the kernel: > Unable to handle kernel paging request at virtual address 000d0804. > [then it gives the register values] > Segmentation fault." > > This address (0xd0804) is the location of a "mailbox" reserved by the IO > card, and from which commands are passed to the card. > > My question: is the kernel using or protecting this area of the memory, > and is there a way to deprotect it??? (how dangerous!) are you accessing it directly? read Documentation/IO-mapping.txt - Arnaldo