From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762846AbXGEU5w (ORCPT ); Thu, 5 Jul 2007 16:57:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760289AbXGEU5p (ORCPT ); Thu, 5 Jul 2007 16:57:45 -0400 Received: from mx1.redhat.com ([66.187.233.31]:60914 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758902AbXGEU5o (ORCPT ); Thu, 5 Jul 2007 16:57:44 -0400 Message-ID: <468D5B28.8080308@redhat.com> Date: Thu, 05 Jul 2007 16:57:12 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Chuck Ebbert CC: Jiri Kosina , Jakub Jelinek , Andrew Morton , Jan Kratochvil , Ingo Molnar , linux-kernel@vger.kernel.org, Ernie Petrides Subject: Re: [PATCH][RESEND] PIE randomization References: <20070511125629.3df919cf.akpm@linux-foundation.org> <20070511133651.63f8a14d.akpm@linux-foundation.org> <20070522161642.b71ddacb.akpm@linux-foundation.org> <20070704082554.GQ7012@devserv.devel.redhat.com> <468D5A3A.1010306@redhat.com> In-Reply-To: <468D5A3A.1010306@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Chuck Ebbert wrote: > On 07/04/2007 01:35 PM, Jiri Kosina wrote: >> On Wed, 4 Jul 2007, Jakub Jelinek wrote: >> >>> The above highlighted changes are the cause of random segfaults of PIE >>> binaries. See >>> https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=246623 >> Thanks a lot for pointing this out. Andrew, could this be folded into >> pie-randomization.patch please? >> >> >> From: Jiri Kosina >> >> pie randomization: fix BAD_ADDR macro >> >> pie-randomization.patch makes the load_addr in load_elf_interp() the load >> bias of ld.so (difference between the actual load base address and first >> PT_LOAD segment's p_vaddr). If the difference equals (on x86) to >> 0xfffff000 (which is valid [1]), SIGSEGV is incorrectly sent. >> >> This patch changes the BAD_ADDR so that it catches the mappings to the >> error-area properly. > > But what about this patch that made the opposite change: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ce51059be56f63762089412b3ece348067afda85 Ohhh, interesting. So the original patch has: #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) For some reason(?) it got changed to the clearly buggy: #define BAD_ADDR(x) ((unsigned long)(x) >= PAGE_MASK) Jiri's patch undoes that second buggy define, which is very different from the original that was sent in by you and Ernie. -- Politics is the struggle between those who want to make their country the best in the world, and those who believe it already is. Each group calls the other unpatriotic.