From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753339AbYCCL4Q (ORCPT ); Mon, 3 Mar 2008 06:56:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751278AbYCCL4E (ORCPT ); Mon, 3 Mar 2008 06:56:04 -0500 Received: from cantor2.suse.de ([195.135.220.15]:34644 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751270AbYCCL4D (ORCPT ); Mon, 3 Mar 2008 06:56:03 -0500 To: "Theodore Ts'o" Cc: linux-kernel@vger.kernel.org Subject: Re: Should a x86 gdb work under an x86_64 kernel? From: Andi Kleen References: Date: Mon, 03 Mar 2008 12:56:00 +0100 In-Reply-To: (Theodore Ts'o's message of "Mon\, 25 Feb 2008 09\:49\:43 -0500") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Theodore Ts'o" writes: > Hi, > > I've noticed that if I try to use a 32-bit x86 gdb to debug a > 32-bit program under a 64-bit x86_64 kernel, gdb (version 6.6-debian, > from Ubuntu Gutsy) immediately core dumps as soon as I run the test > program under the debugger. Is this normal/expected/known bug? It's clearly a bug. x86-64 compat user space should be 99+% compatible and running full 32bit user land with a 64bit kernel is supposed to work. The main exceptions are a few programs that rely on the 3GB address space (these can be used with linux32 --3gb), some programs which make bogus assumptions about /proc,/sys which cannot be fixed and a few programs which use obscure driver specific ioctls with no compat wrapper. -Andi