From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from e06smtp17.uk.ibm.com ([195.75.94.113]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ua6IV-0003ua-1R for kexec@lists.infradead.org; Wed, 08 May 2013 15:28:51 +0000 Received: from /spool/local by e06smtp17.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 8 May 2013 16:25:23 +0100 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id A52161B0805D for ; Wed, 8 May 2013 16:28:22 +0100 (BST) Received: from d06av07.portsmouth.uk.ibm.com (d06av07.portsmouth.uk.ibm.com [9.149.37.248]) by b06cxnps3075.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r48FSCCn43516028 for ; Wed, 8 May 2013 15:28:12 GMT Received: from d06av07.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av07.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r48FSMK5010628 for ; Wed, 8 May 2013 11:28:22 -0400 Date: Wed, 8 May 2013 17:28:20 +0200 From: Michael Holzheu Subject: Re: [PATCH 0/4] kdump: Allow ELF header creation in new kernel Message-ID: <20130508172820.77075d23@holzheu> In-Reply-To: <20130507163701.GA14403@redhat.com> References: <1367845799-29125-1-git-send-email-holzheu@linux.vnet.ibm.com> <20130507163701.GA14403@redhat.com> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Vivek Goyal Cc: kexec@lists.infradead.org, Heiko Carstens , linux-kernel@vger.kernel.org, Jan Willeke , HATAYAMA Daisuke , Martin Schwidefsky Hello Vivek, On Tue, 7 May 2013 12:37:01 -0400 Vivek Goyal wrote: > On Mon, May 06, 2013 at 03:09:55PM +0200, Michael Holzheu wrote: > > Hello Vivek, > > > > For s390 we want to use /proc/vmcore for our SCSI stand-alone > > dump (zfcpdump). We have support where the first HSA_SIZE bytes are > > saved into a hypervisor owned memory area (HSA) before the kdump > > kernel is booted. When the kdump kernel starts, it is restricted > > to use only HSA_SIZE bytes. > > > > Hi Michael, > > Hatayama is changing /proc/vmcore interface to support mmap(). Can you > please rebase your changes on top of those patches. > > http://thread.gmane.org/gmane.linux.kernel/1477622 Fine, we will do that. > Secondly, I think /proc/vmcore does not have to know whether elf > headers are in old memory or new memory. Given that s390 is taking > a deviation, so it now becomes an arch specific detail. Can't we > just create few arch specific helper functions to retrieve and free > elf headers. > > - arch_get_crash_headers() > - All arch except return elfcorehdr_add except s390. > - arch_read_crash_header_data() > - All arch just call into read_from_oldmem() except s390. We > can provide a generic implementation in /proc/vmcore.c so > all other arch can use that generic implementation. Or > use symbol override trick. > - arch_free_crash_headers() > - All arch do nothing except s390 which can reclaim the memory > for elf headers prepared. Generic code has parsed/copied > the headers by now. > > What do you think? Above 3 calls should solve the problem and allow > arch to handle elf headers differently. And generic implementation > still keeps common logic for processing headers. Ok, we will try that. There might be a problem that our ELF notes content is also in the new kernel memory. But also for that there be a solution. Michael _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec