From mboxrd@z Thu Jan 1 00:00:00 1970 Reply-To: kernel-hardening@lists.openwall.com Sender: Ingo Molnar Date: Sat, 7 Jan 2017 08:46:58 +0100 From: Ingo Molnar Message-ID: <20170107074658.GC13565@gmail.com> References: <20170104221630.831-1-thgarnie@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: [kernel-hardening] Re: [RFC] x86/mm/KASLR: Remap GDTs at fixed location To: Andy Lutomirski Cc: Thomas Garnier , Linus Torvalds , Arjan van de Ven , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Kees Cook , Borislav Petkov , Dave Hansen , Chen Yucong , Paul Gortmaker , Andrew Morton , Masahiro Yamada , Sebastian Andrzej Siewior , Anna-Maria Gleixner , Boris Ostrovsky , Rasmus Villemoes , Michael Ellerman , Juergen Gross , Richard Weinberger , X86 ML , "linux-kernel@vger.kernel.org" , "kernel-hardening@lists.openwall.com" List-ID: * Andy Lutomirski wrote: > > When I looked at the fixmap, you had to define the space you need ahead of > > time and I am not sure there was enough space as you said. > > Can you try it and see if anything goes wrong? Even if something does go wrong, > I think we should fix *that* rather than making the memory layout more > complicated. Absolutely! This should always be the driving principle when complicating the kernel's memory layout. Thanks, Ingo From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S941052AbdAGHrE (ORCPT ); Sat, 7 Jan 2017 02:47:04 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:33623 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751218AbdAGHrD (ORCPT ); Sat, 7 Jan 2017 02:47:03 -0500 Date: Sat, 7 Jan 2017 08:46:58 +0100 From: Ingo Molnar To: Andy Lutomirski Cc: Thomas Garnier , Linus Torvalds , Arjan van de Ven , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Kees Cook , Borislav Petkov , Dave Hansen , Chen Yucong , Paul Gortmaker , Andrew Morton , Masahiro Yamada , Sebastian Andrzej Siewior , Anna-Maria Gleixner , Boris Ostrovsky , Rasmus Villemoes , Michael Ellerman , Juergen Gross , Richard Weinberger , X86 ML , "linux-kernel@vger.kernel.org" , "kernel-hardening@lists.openwall.com" Subject: Re: [RFC] x86/mm/KASLR: Remap GDTs at fixed location Message-ID: <20170107074658.GC13565@gmail.com> References: <20170104221630.831-1-thgarnie@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Lutomirski wrote: > > When I looked at the fixmap, you had to define the space you need ahead of > > time and I am not sure there was enough space as you said. > > Can you try it and see if anything goes wrong? Even if something does go wrong, > I think we should fix *that* rather than making the memory layout more > complicated. Absolutely! This should always be the driving principle when complicating the kernel's memory layout. Thanks, Ingo