From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752443AbdI0Qu4 (ORCPT ); Wed, 27 Sep 2017 12:50:56 -0400 Received: from bombadil.infradead.org ([65.50.211.133]:38200 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751959AbdI0Qux (ORCPT ); Wed, 27 Sep 2017 12:50:53 -0400 Date: Wed, 27 Sep 2017 09:50:51 -0700 From: Darren Hart To: Mario.Limonciello@dell.com Cc: andy.shevchenko@gmail.com, pali.rohar@gmail.com, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org, quasisec@google.com Subject: Re: [PATCH 06/12] platform/x86: dell-wmi-smbios: Add a sysfs interface for SMBIOS tokens Message-ID: <20170927165051.GE23572@fury> References: <1342f21a4f2c9af86d3033a9af9d9a4d05d27106.1505999739.git.mario.limonciello@dell.com> <20170925162333.GL22190@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 25, 2017 at 05:31:05PM +0000, Mario.Limonciello@dell.com wrote: > > -----Original Message----- > > From: Andy Shevchenko [mailto:andy.shevchenko@gmail.com] > > Sent: Monday, September 25, 2017 1:04 PM > > To: Pali Rohár > > Cc: Limonciello, Mario ; dvhart@infradead.org; > > LKML ; Platform Driver > x86@vger.kernel.org>; quasisec@google.com > > Subject: Re: [PATCH 06/12] platform/x86: dell-wmi-smbios: Add a sysfs interface > > for SMBIOS tokens > > > > On Mon, Sep 25, 2017 at 7:23 PM, Pali Rohár wrote: > > > On Thursday 21 September 2017 08:57:11 Mario Limonciello wrote: > > >> Currently userspace tools can access system tokens via the dcdbas > > >> kernel module and a SMI call that will cause the platform to execute > > >> SMM code. > > >> > > >> With a goal in mind of deprecating the dcdbas kernel module a different > > >> method for accessing these tokens from userspace needs to be created. > > >> > > >> This is intentionally marked to only be readable as root as it can > > >> contain sensitive information about the platform's configuration. > > > > > > Darren, Andy, any comments? I'm not quite sure if such API is suitable > > > for long term in kernel. > > > > I would try to avoid sysfs interfaces for some particular devices. > > Besides we are creating a character device. Would it be suitable there? > > If the character device having 2 different ioctls for different needs is > acceptable I'm happy to adjust the series to do this instead. One piece of feedback I had re the char device was to see if we could avoid the need for the IOCTL altogether, I'd like to have that discussion before we add another. > > > > > > Basically tokens are list of tuples with > > > possibility to active them, right? > > > > > I didn't add a way to activate them through this, it was only for > reading purpose. Activating them should be possible through the > SMBIOS calling interface though. > These are read-only as I understood it, and only with the right privileges. Sysfs seemed appropriate for this to me. -- Darren Hart VMware Open Source Technology Center