Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753274AbZAFFzO (ORCPT ); Tue, 6 Jan 2009 00:55:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751013AbZAFFzA (ORCPT ); Tue, 6 Jan 2009 00:55:00 -0500 Received: from wf-out-1314.google.com ([209.85.200.171]:40652 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750950AbZAFFy7 (ORCPT ); Tue, 6 Jan 2009 00:54:59 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=mwz89t4tHRfyNWPVOT1lpXzA3T5RjuDnux2bpHr02IAH6z2MKddXdoOXKm8CYXcS0T VMlh20FoIXkNvQ35bGZ0WiZ2mPm1l+qGK6QmGymc/8ipupGu3nUb8VbN7apk0YmrcfNf J+PqVseYO462MpejbezajkuyJEMsh+nAzzMjo= Message-ID: <8bd0f97a0901052154w213f9a03oafdd07645b1b7dc7@mail.gmail.com> Date: Tue, 6 Jan 2009 00:54:58 -0500 From: "Mike Frysinger" To: "Greg KH" Subject: Re: debugfs & vfs file permission issue? Cc: "Robin Getz" , viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org In-Reply-To: <20090106054858.GA9040@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200901052157.07306.rgetz@blackfin.uclinux.org> <20090106054858.GA9040@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1266 Lines: 33 On Tue, Jan 6, 2009 at 00:48, Greg KH wrote: > On Mon, Jan 05, 2009 at 09:57:07PM -0500, Robin Getz wrote: >> On 2.6.28-rc2, If I create a debugfs file with >> >> debugfs_create_x16("SPORT1_TX", 0200 , parent, 0xFFC00910); > > Um, are you are passing in a pointer to a known memory location > properly? Why would it be ok for the kernel to directly read that > location? it's a nommu system and the 0xffc00000+ addresses are always available >> Although the file shows up as write only (no read): >> >> root:/> ls -l /sys/kernel/debug/blackfin/SPORT/SPORT1_TX >> --w------- 1 root root 0 Jan 1 >> 2007 /sys/kernel/debug/blackfin/SPORT/SPORT1_TX >> >> root:/> cat /sys/kernel/debug/blackfin/SPORT/SPORT1_TX >> >> Still works - and causes the read to occur, which crashes :( > > You're root, you can do anything :) any thoughts on how to declare debugfs files that are read or write only ? we'll have to add new helper functions or have it be a parameter or declare our own debugfs file ? -mike -- 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/