From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756199AbdELGUI (ORCPT ); Fri, 12 May 2017 02:20:08 -0400 Received: from mx2.suse.de ([195.135.220.15]:38093 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755287AbdELGUG (ORCPT ); Fri, 12 May 2017 02:20:06 -0400 Date: Fri, 12 May 2017 08:20:04 +0200 From: Michal Hocko To: Pavel Machek Cc: Jingoo Han , Lee Jones , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: setting brightness as privileged operation? Message-ID: <20170512062003.GB6803@dhcp22.suse.cz> References: <20170105092307.GD21618@dhcp22.suse.cz> <20170511210755.GA1360@xo-6d-61-c0.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170511210755.GA1360@xo-6d-61-c0.localdomain> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 11-05-17 23:07:55, Pavel Machek wrote: > On Thu 2017-01-05 10:23:07, Michal Hocko wrote: > > Hi, > > I have just learned that my Xfce Power Manager cannot manipulate > > brightness because I do not have policykit installed on my computer. > > There is a reason for that (yeah it depends on systemd which I prefer > > not have). > > > > While this is clearly a problem of the Xfce applet I am wondering why > > setting the brightness has to be a privileged operation at all. Is there > > any strong reason for it or just a general policy that we do not give > > world writable files into sysfs? > > Well, if you have another user logged in using ssh, and changing _your_ > brightness, that will be somehow annoying, right? I am pretty sure that such a user can do much larger harm than playing with brigtness of my LCD. Anyway I went with my own rc.local hack. -- Michal Hocko SUSE Labs