From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wm0-x22b.google.com ([2a00:1450:400c:c09::22b]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bn456-0001tm-6U for kexec@lists.infradead.org; Thu, 22 Sep 2016 13:30:29 +0000 Received: by mail-wm0-x22b.google.com with SMTP id l132so328199667wmf.0 for ; Thu, 22 Sep 2016 06:30:06 -0700 (PDT) Received: from [192.168.1.2] (191.181.12.109.rev.sfr.net. [109.12.181.191]) by smtp.gmail.com with ESMTPSA id bw9sm2124700wjc.33.2016.09.22.06.30.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Sep 2016 06:30:03 -0700 (PDT) From: Louis Bouchard Subject: makedumpfile issues many readpage_elf: Attempt to read non-existent page Message-ID: <57E3DCDB.5020308@canonical.com> Date: Thu, 22 Sep 2016 15:30:03 +0200 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=infradead.org@lists.infradead.org To: "kexec@lists.infradead.org" Hello, I am investigating an issue with makedumpfile and kernel 4.8 where makedumpfile (1.6.0) exits on error with the following message : get_mem_map: Can't distinguish the memory type. I found commit 2c21d4656e8d3c2af2b1e14809d076941ae69e96 in the upstream development branch that is supposed to fix this : [PATCH v2] Support _count -> _refcount rename in struct page _count member was renamed to _refcount in linux commit 0139aa7b7fa12 ("mm: rename _count, field of the struct page, to _refcount") and this broke makedumpfile. The reason for making the change was to find all users accessing it directly and not through the recommended API. I tried suggesting to revert the change but failed, I see no other choice than to start supporting both _count and _refcount in makedumpfile. Though, when I apply the patch and test on either Ubuntu's 4.8.0-11 kernel, or kernel.org's mainline 4.8.0-040800rc7 kernel, I get the following repeated multiple times : > makedumpfile -c -d 31 /proc/vmcore /var/crash/201609221517/dump-incomplete > [ 7.513337] kdump-tools[715]: readpage_elf: Attempt to read non-existent page at 0x134dfff78000. > [ 7.524186] kdump-tools[715]: readmem: type_addr: 0, addr:ffff9b4dfff78000, size:16 > [ 7.528440] kdump-tools[715]: section_mem_map_addr: Can't get a struct mem_section(ffff9b4dfff78000). > [ 7.536562] kdump-tools[715]: readpage_elf: Attempt to read non-existent page at 0x134dfff78000. > [ 7.544356] kdump-tools[715]: readmem: type_addr: 0, addr:ffff9b4dfff78010, size:16 > [ 7.552422] kdump-tools[715]: section_mem_map_addr: Can't get a struct mem_section(ffff9b4dfff78010). > [ 7.560317] kdump-tools[715]: readpage_elf: Attempt to read non-existent page at 0x134dfff78000. > [ 7.568422] kdump-tools[715]: readmem: type_addr: 0, addr:ffff9b4dfff78020, size:16 > [ 7.572296] kdump-tools[715]: section_mem_map_addr: Can't get a struct mem_section(ffff9b4dfff78020). I also tested with all the commits in the upstream/development branch with no luck, I still get the same behavior. Does someone have an idea of where this could come from ? TIA, Louis -- Louis Bouchard Software engineer, Cloud & Sustaining eng. Canonical Ltd Ubuntu developer Debian Maintainer GPG : 429D 7A3B DD05 B6F8 AF63 B9C4 8B3D 867C 823E 7A61 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec