From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933236AbbENKmI (ORCPT ); Thu, 14 May 2015 06:42:08 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:44094 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933032AbbENKlh (ORCPT ); Thu, 14 May 2015 06:41:37 -0400 X-Originating-IP: 50.43.43.179 Date: Thu, 14 May 2015 03:41:28 -0700 From: Josh Triplett To: Arjan van de Ven Cc: Ingo Molnar , Alex Henrie , One Thousand Gnomes , Kees Cook , "H . Peter Anvin" , Doug Johnson , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] x86: Preserve iopl on fork and execve Message-ID: <20150514104127.GA31892@x> References: <1431387505-13410-1-git-send-email-alexhenrie24@gmail.com> <20150512064032.GA25097@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Tue, May 12, 2015 at 08:25:59AM -0700, Arjan van de Ven wrote: > > also the interesting question is: > > can a process give up these perms? > > otherwise it becomes a "once given, never gotten rid of" hell hole. > > If you look at a modern linux distro, nothing should need/use iopl and > co anymore, so maybe an interesting > question is if we can stick these behind a CONFIG_ option (default on > of course for compatibility)... just like > some of the /dev/mem like things are now hidable for folks who know > they don't need them. I have a patch series that does exactly that, compiling out the syscalls as well as the underlying architecture-specific infrastructure. (Saves quite a bit of space, too.) It still needs some more detailed x86 architecture review. Peter, Ingo? Would you be interested in taking (an updated version of) that patch series for the next merge window? - Josh Triplett