Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761603AbcLPOzr (ORCPT ); Fri, 16 Dec 2016 09:55:47 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35466 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755331AbcLPOzi (ORCPT ); Fri, 16 Dec 2016 09:55:38 -0500 Subject: Re: RFC: capabilities(7): notes for kernel developers To: Casey Schaufler , John Stultz References: <43dcc6dc-265b-5eaf-3a70-701e05200b9f@gmail.com> <9ed6371f-3d38-45b1-a85b-1fbb3e5b4fc7@schaufler-ca.com> <7a6b5f38-de8e-d8d4-e6f7-feae3f8d192e@schaufler-ca.com> Cc: mtk.manpages@gmail.com, "Serge E. Hallyn" , James Morris , Kees Cook , Andy Lutomirski , Jann Horn , "Eric W. Biederman" , linux-man , linux-security-module , lkml From: "Michael Kerrisk (man-pages)" Message-ID: Date: Fri, 16 Dec 2016 15:55:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <7a6b5f38-de8e-d8d4-e6f7-feae3f8d192e@schaufler-ca.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1612 Lines: 45 On 12/16/2016 01:44 AM, Casey Schaufler wrote: > On 12/15/2016 4:31 PM, John Stultz wrote: >> On Thu, Dec 15, 2016 at 12:40 PM, Casey Schaufler >> wrote: >>> On 12/15/2016 11:41 AM, Michael Kerrisk (man-pages) wrote: >>>> On 12/15/2016 05:29 PM, Casey Schaufler wrote: >>>>> CAP_WAKE_ALARM could readily be CAP_TIME. >>>> Actually, I don't quite understand what you mean with that sentence. >>>> Could you elaborate? >>> Should have said CAP_SYS_TIME >>> >>> Setting an alarm could be considered a time management function, >>> depending on what it actually does. >> Just a nit here. CAP_WAKE_ALARM is more about the privilege of waking >> a system from suspend, while CAP_SYS_TIME covers the ability to set >> the time. One wouldn't necessarily want to give applications which >> could wake a system up the capability to also set the time. > > Doesn't really matter, except that an ignorant developer > might make the mistake I did and assume that WAKE_ALARM > was somehow related to time management. If you want to use > it as an example don't let my dunderheadedness get in your > way. Actually, I decided it wasn't such a good example anyway. That capability could potentially be generic. (But it probably should better have been named something like 'CAP_WAKE_SYSTEM'.) >> thanks >> -john > > Again, thank you for taking this on. It should be a > big help. You're welcome. And thanks for your help, Casey. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/