From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932409AbXCZUSK (ORCPT ); Mon, 26 Mar 2007 16:18:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932253AbXCZUSK (ORCPT ); Mon, 26 Mar 2007 16:18:10 -0400 Received: from mylar.outflux.net ([69.93.193.226]:53296 "EHLO mylar.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932436AbXCZUSI (ORCPT ); Mon, 26 Mar 2007 16:18:08 -0400 Date: Mon, 26 Mar 2007 13:17:43 -0700 From: Kees Cook To: Hugh Dickins Cc: Andrew Morton , Linus Torvalds , Marcus Meissner , Andi Kleen , Ingo Molnar , Dave Jones , Arjan van de Ven , linux-kernel@vger.kernel.org Subject: Re: revert PIE randomization? Message-ID: <20070326201743.GZ22797@outflux.net> References: <20070321181730.GV22797@outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Outflux X-HELO: gorgon.outflux.net Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 21, 2007 at 08:01:50PM +0000, Hugh Dickins wrote: > It was in doing kernel builds that I hit it, nothing special: an > overnight cycle of kernel building would collapse in a few hours. > openSUSE 10.2. I wonder it was the combination of the base addr randomization patch and something specific to the openSuSE loader that was sparking the failures? I ran about 22 million execs on Ubuntu Feisty (patched to re-include the base addr randomization), with a PIE bash, and never saw it. Hmpf. > Andi would tell definitively, but I guess it's merely that with so > much more address space to play with, x86_64 can divide up that space > more satisfactorily. > > But don't be misled: try "ulimit -s unlimited" and I expect you'll > find i386 allocating mmap addresses (hence libraries) from the > opposite end, below ELF_ET_DYN_BASE. Is there any explicitly documented per-arch "here is the memory layout of a process"? I haven't been able to find anything like this. I suspect it would be a good reference to have; so if no one has any hints, I'll try to get something written up. -- Kees Cook @outflux.net