From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267226AbUG1PXs (ORCPT ); Wed, 28 Jul 2004 11:23:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267230AbUG1PXs (ORCPT ); Wed, 28 Jul 2004 11:23:48 -0400 Received: from jade.spiritone.com ([216.99.193.136]:42207 "EHLO jade.spiritone.com") by vger.kernel.org with ESMTP id S267226AbUG1PXk (ORCPT ); Wed, 28 Jul 2004 11:23:40 -0400 Date: Wed, 28 Jul 2004 08:23:29 -0700 From: "Martin J. Bligh" To: "Eric W. Biederman" , suparna@in.ibm.com cc: Andrew Morton , fastboot@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [Fastboot] Re: Announce: dumpfs v0.01 - common RAS output API Message-ID: <120540000.1091028208@[10.10.2.4]> In-Reply-To: References: <16734.1090513167@ocs3.ocs.com.au><20040725235705.57b804cc.akpm@osdl.org><20040728105455.GA11282@in.ibm.com> X-Mailer: Mulberry/2.2.1 (Linux/x86) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >> > Does anyone have a proof of concept implementation? I have been able to find >> >> Yes, Hari has a nice POC implementation - it might make sense for him to post >> it rightaway for you to take a look. Basically, in addition to hmem (oldmem), >> the upcoming kernel exports an ELF core view of the saved register and memory >> state of the previous kernel as /proc/vmcore.prev (remember your suggestion >> of using an ELF core file format for dump ?), so one can use cp or scp to >> save the core dump to disk. He has a quick demo, where he uses gdb (unmodified) >> to open the dump and show a stack trace of the dumping cpu. > > Yes I would like to look at that. > > I am tempted to suggest the data buffer with the registers and memory > actually be in ELF format with virtual address representing where the > data was in memory, and the physical addresses reporting where the > data actually is in memory now. Then we could just grab everything > with /dev/mem.. > > But I don't know how much of pain this would be. /dev/mem expects mem_map to be there, the size of which would easily blow away the reserved section. /dev/oldmem (or whatever we call it) is just a magic copy that does a kmap-like operation to get at pages without a struct page. M.