From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756598AbcBQHV3 (ORCPT ); Wed, 17 Feb 2016 02:21:29 -0500 Received: from mail-wm0-f44.google.com ([74.125.82.44]:33766 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754244AbcBQHV1 (ORCPT ); Wed, 17 Feb 2016 02:21:27 -0500 Date: Wed, 17 Feb 2016 08:21:23 +0100 From: Ingo Molnar To: Andy Lutomirski Cc: x86@kernel.org, Denys Vlasenko , Stas Sergeev , Cyrill Gorcunov , Pavel Emelyanov , Brian Gerst , "linux-kernel@vger.kernel.org" , Linus Torvalds , Oleg Nesterov , Borislav Petkov Subject: Re: [PATCH v5 1/4] x86/signal/64: Add a comment about sigcontext->fs and gs Message-ID: <20160217072122.GA19718@gmail.com> References: 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 * Andy Lutomirski wrote: > + * If the kernel ever adds explicit fs, gs, fsbase, and gsbase > + * save/restore, it will most likely need to be opt-in and use > + * different context slots. Btw., that's not necessarily true: it could also be made opt-out, and a modify_ldt() or any other cleanly identifiable legacy usage/signature that is associated with DOSEMU might trigger the opt-out automatically as well. I.e. behaviorally it would still keep the ABI and modern default behavior could still be whatever we want to make it. Thanks, Ingo