From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from e06smtp14.uk.ibm.com ([195.75.94.110]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WSTzy-0000ug-J6 for kexec@lists.infradead.org; Tue, 25 Mar 2014 16:14:47 +0000 Received: from /spool/local by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 25 Mar 2014 16:14:24 -0000 Received: from b06cxnps4076.portsmouth.uk.ibm.com (d06relay13.portsmouth.uk.ibm.com [9.149.109.198]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id 2E38B17D8059 for ; Tue, 25 Mar 2014 16:15:08 +0000 (GMT) Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213]) by b06cxnps4076.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s2PGEAvc60096722 for ; Tue, 25 Mar 2014 16:14:10 GMT Received: from d06av03.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av03.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s2PGELRp029779 for ; Tue, 25 Mar 2014 10:14:22 -0600 Date: Tue, 25 Mar 2014 17:14:20 +0100 From: Michael Holzheu Subject: [PATCH 2/2] makedumpfile: Use max_pfn from mem_map array Message-ID: <20140325171420.6b558576@holzheu> 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: Atsushi Kumagai Cc: d.hatayama@jp.fujitsu.com, kexec@lists.infradead.org There are dump mechansims like s390 stand-alond dump or KVM virsh dump that write the physical memory of a machine and are not aware of the dumped operating system. For those dump mechanisms it can happen that for the Linux kernel of the dumped system the "mem=" kernel parameter has been specified. In this case max_mapnr that makedumpfile gets from the ELF header can be bigger than the maximum page frame number used by the dumped Linux kernel. With this patch makedumpfile gets the maximum page frame number from the mem_map array and adjusts info->max_mapnr if this value is smaller than the value calculated from the ELF header. Signed-off-by: Michael Holzheu --- makedumpfile.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) --- a/makedumpfile.c +++ b/makedumpfile.c @@ -2829,7 +2829,8 @@ get_mem_map_without_mm(void) int get_mem_map(void) { - int ret; + unsigned long max_pfn = 0; + int ret, i; switch (get_mem_type()) { case SPARSEMEM: @@ -2861,6 +2862,17 @@ get_mem_map(void) ret = FALSE; break; } + /* + * Adjust "max_mapnr" for the case that Linux uses less memory + * than is dumped. For example when "mem=" has been used for the + * dumped system. + */ + for (i = 0; i < info->num_mem_map; i++) { + if (info->mem_map_data[i].mem_map == NOT_MEMMAP_ADDR) + continue; + max_pfn = MAX(max_pfn, info->mem_map_data[i].pfn_end); + } + info->max_mapnr = MIN(info->max_mapnr, max_pfn); return ret; } _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec