From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762232AbYHICVR (ORCPT ); Fri, 8 Aug 2008 22:21:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755066AbYHICVE (ORCPT ); Fri, 8 Aug 2008 22:21:04 -0400 Received: from e36.co.us.ibm.com ([32.97.110.154]:57731 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752904AbYHICVC (ORCPT ); Fri, 8 Aug 2008 22:21:02 -0400 Subject: Re: [RFC][PATCH 2/4] checkpoint/restart: x86 support From: Dave Hansen To: Oren Laadan Cc: containers@lists.linux-foundation.org, Theodore Tso , linux-kernel@vger.kernel.org, Arnd Bergmann In-Reply-To: <489CF0CE.1000603@cs.columbia.edu> References: <20080807224033.FFB3A2C1@kernel> <200808081409.30591.arnd@arndb.de> <489CAC70.7090809@cs.columbia.edu> <200808090029.28286.arnd@arndb.de> <489CD0F9.9060603@cs.columbia.edu> <1218242286.19082.62.camel@nimitz> <489CF0CE.1000603@cs.columbia.edu> Content-Type: text/plain Date: Fri, 08 Aug 2008 19:20:58 -0700 Message-Id: <1218248458.19082.68.camel@nimitz> Mime-Version: 1.0 X-Mailer: Evolution 2.22.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2008-08-08 at 21:20 -0400, Oren Laadan wrote: > hehehe .. both; I meant that while it doesn't change per architecture, it > varies between architectures. So "struct pt_regs" compiled for x86-32 is > different than that compiled for x86-64. Therefore we can't just dump the > structure as is and expect that 64 bit would be able to parse the 32 bit. > In other words, we need an intermediate representation. Surely we already handle this, though. Don't we allow a 32-bit app running on a 64-bit kernel to PTRACE_GETREGS and get the 32-bit version? A 64-bit app will get the 64-bit version making the same syscall. It's all handled in the syscall compatibility code. -- Dave