From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752145Ab3KKCsT (ORCPT ); Sun, 10 Nov 2013 21:48:19 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44836 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003Ab3KKCsL (ORCPT ); Sun, 10 Nov 2013 21:48:11 -0500 Date: Mon, 11 Nov 2013 10:47:01 +0800 From: Dave Young To: "H. Peter Anvin" Cc: Matt Fleming , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, x86@kernel.org, mjg59@srcf.ucam.org, James.Bottomley@HansenPartnership.com, vgoyal@redhat.com, ebiederm@xmission.com, horms@verge.net.au, kexec@lists.infradead.org, bp@alien8.de, Greg KH Subject: Re: [patch 0/7 v2] kexec kernel efi runtime support Message-ID: <20131111024701.GD4407@dhcp-16-126.nay.redhat.com> References: <20131105082007.872550445@dhcp-16-126.nay.redhat.com> <20131108143118.GA22636@console-pimps.org> <20131109035739.GB4294@dhcp-16-126.nay.redhat.com> <527DC1BE.6030107@zytor.com> <20131111021356.GC4407@dhcp-16-126.nay.redhat.com> <52803F15.3080204@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52803F15.3080204@zytor.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/10/13 at 06:21pm, H. Peter Anvin wrote: > On 11/10/2013 06:13 PM, Dave Young wrote: > > > > Huang Ying created the debugfs file for boot_params. > > His first version patch tried sysfs, but sysfs is not designed for such > > binary blobs so finally it go to debugfs. > > > > That is a misunderstanding. Binary blobs can exist in sysfs as long as > the blob is something that is inherently a blob. This is admittedly a > corner case, but it is without any doubt a protocol-defined binary > structure. You are right. Greg objected that the whole structure being exported directly. > > The reason it was put in debugfs is that there was no non-debug user for > it at the time. Ok, I did not know this background. > > > Any idea for this is welcome, till now I have no better idea for such kind > > of data. We should have another *fs instead of using debugfs. > > The problem with debugfs is that things go into debugfs with largely no > auditing. As a result, mounting debugfs is very likely to mean that > your system is exploitable one way or another. Hmm, agree. Thanks for explaining about it. Thanks Dave