From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265636AbUBGAhq (ORCPT ); Fri, 6 Feb 2004 19:37:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265657AbUBGAhq (ORCPT ); Fri, 6 Feb 2004 19:37:46 -0500 Received: from cpe-24-221-190-179.ca.sprintbbd.net ([24.221.190.179]:38559 "EHLO myware.akkadia.org") by vger.kernel.org with ESMTP id S265636AbUBGAho (ORCPT ); Fri, 6 Feb 2004 19:37:44 -0500 Message-ID: <4024333B.6020805@redhat.com> Date: Fri, 06 Feb 2004 16:37:15 -0800 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7a) Gecko/20040205 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrea Arcangeli CC: Rik van Riel , Jamie Lokier , Andi Kleen , johnstul@us.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH] linux-2.6.2-rc2_vsyscall-gtod_B1.patch References: <20040205214348.GK31926@dualathlon.random> <20040206042815.GO31926@dualathlon.random> <40235D0B.5090008@redhat.com> <20040206154906.GS31926@dualathlon.random> In-Reply-To: <20040206154906.GS31926@dualathlon.random> X-Enigmail-Version: 0.83.2.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrea Arcangeli wrote: > by the same argument the 2.6 i386 vsyscall is not acceptable too since > it has an hardcoded address too that is the same for all binary kernels > that you ship, and furthmore it has the sysenter or int 0x80 hardcoded > at a fixed address to jump into. You don't read what I write. The official kernel might have the vdso at a fixed address part no part of the ABI requires this address and so anybody with some security conscience can change the kernel to randomize the vdso address. It's not my or Ingo's fault that Linus doesn't like the exec-shield code which would introduce the randomization. The important aspect is that we can add vdso randomization and nothing else needs changing. The same libc will run6 on a stock kernel and the one with the randomized vdso. This is not the case on x86-64 where the absolute address for the gettimeofday is used. -- ➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖