Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752504AbcDZUud (ORCPT ); Tue, 26 Apr 2016 16:50:33 -0400 Received: from one.firstfloor.org ([193.170.194.197]:53277 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248AbcDZUuc (ORCPT ); Tue, 26 Apr 2016 16:50:32 -0400 Date: Tue, 26 Apr 2016 13:50:30 -0700 From: Andi Kleen To: Andy Lutomirski Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Borislav Petkov , Brian Gerst , Andi Kleen Subject: Re: [PATCH 5/8] x86/arch_prctl/64: Remove FSBASE/GSBASE < 4G optimization Message-ID: <20160426205030.GI13997@two.firstfloor.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 353 Lines: 9 On Tue, Apr 26, 2016 at 12:23:28PM -0700, Andy Lutomirski wrote: > As far as I know, the optimization doesn't work on any modern distro > because modern distros use high addresses for ASLR. Remove it. I disagree with this patch. For example it will be a regression for static executables. And randomly making old systems slower is a bad idea. -Andi