From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from gv-out-0910.google.com ([216.239.58.191]) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1N5L5G-0007D9-Qw for kexec@lists.infradead.org; Tue, 03 Nov 2009 15:14:16 +0000 Received: by gv-out-0910.google.com with SMTP id r4so739991gve.5 for ; Tue, 03 Nov 2009 07:14:09 -0800 (PST) Message-ID: <4AF048D1.4090402@gmail.com> Date: Tue, 03 Nov 2009 16:14:25 +0100 From: Jiri Slaby MIME-Version: 1.0 Subject: Re: kdump fails to load and crashes [was: mmotm 2009-11-01-10-01 uploaded] References: <200911011807.nA1I7o95016136@imap1.linux-foundation.org> <4AEF673E.5030509@gmail.com> <20091103144450.GB4235@redhat.com> In-Reply-To: <20091103144450.GB4235@redhat.com> 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-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Vivek Goyal Cc: mm-commits@vger.kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, hbabu@us.ibm.com, "Eric W. Biederman" , Andrew Morton On 11/03/2009 03:44 PM, Vivek Goyal wrote: > On Tue, Nov 03, 2009 at 12:11:58AM +0100, Jiri Slaby wrote: >> On 11/01/2009 07:07 PM, akpm@linux-foundation.org wrote: >>> The mm-of-the-moment snapshot 2009-11-01-10-01 has been uploaded to >> >> Hi, kdump loading crashes: >> BUG: unable to handle kernel paging request at ffff8800010a7000 >> IP: [] machine_kexec_prepare+0x16b/0x13e0 >> PGD 1806063 PUD 180a063 PMD 10001e1 ... >> ffff8800010a7000 should be OK, as crashkernel=64M@16M was passed to the >> kernel. >> > > This is strange. As you said, ffff8800010a7000, should be a valid address > as you reserved memory from 16M. Hmm, PMD has not RW bit set and we do store (see below). > I took above -mm and for me kernel loads fine. I reserved memory 64M@32M > as by default kernel is loading at address 16M. > > How does your /proc/iomem look like in first kernel? I'm not any longer on that machine. init_pgtable() overwrites random memory, so possibly even host's page tables, hence the oops above, I suppose. I'm currently chasing it down in the qemu virtual machine, since I already got a garbage into my ~/.viminfo (some overwritten page got flushed, I guess). There /proc/iomem looks like: 00100000-12beffff : System RAM 01000000-04ffffff : Crash kernel 01000000-014680c2 : Kernel code 014680c3-016f39f7 : Kernel data 0175b000-017d97ab : Kernel bss I'll keep you informed. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec