Re: [Crash-utility] crash: invalid kernel virtual address: 0 type: "memory section"

On Mon, Jan 5, 2015 at 6:49 PM, Dave Anderson <anderson(a)redhat.com&gt; wrote: > > > Just for sanity's sake, try this: > > $ ./crash --minimal ../ddeb/usr/lib/debug/boot/vmlinux-3.13.0-39-generic ../dump.201412280256 > > and see if you can read the linux_banner string successfully. For example, using > my sample 3.13 kernel: > > $ crash --minimal 3.13.0-0.rc1.git2.1.fc20_SLAB/vmlinux.gz 3.13.0-0.rc1.git2.1.fc20_SLAB/vmcore_c_d31 > > crash 7.0.9 > Copyright (C) 2002-2014 Red Hat, Inc. > Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation > Copyright (C) 1999-2006 Hewlett-Packard Co > Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited > Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. > Copyright (C) 2005, 2011 NEC Corporation > Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc. > Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. > This program is free software, covered by the GNU General Public License, > and you are welcome to change it and/or distribute copies of it under > certain conditions. Enter "help copying" to see the conditions. > This program has absolutely no warranty. Enter "help warranty" for > details. > > GNU gdb (GDB) 7.6 > Copyright (C) 2013 Free Software Foundation, Inc. > License GPLv3+: GNU GPL version 3 or later > <http://gnu.org/licenses/gpl.html> > This is free software: you are free to change and redistribute it. > There is NO WARRANTY, to the extent permitted by law. Type "show copying" > and "show warranty" for details. > This GDB was configured as "x86_64-unknown-linux-gnu"... > > NOTE: minimal mode commands: log, dis, rd, sym, eval, set, extend and exit > > crash> rd -a linux_banner > ffffffff818000c0: Linux version 3.13.0-0.rc1.git2.1.fc20.x86_64 (root@hp-xw455 > ffffffff818000fc: 0-02.ml3.eng.bos.redhat.com) (gcc version 4.8.1 20130814 (Re > ffffffff81800138: d Hat 4.8.1-6) (GCC) ) #1 SMP Tue Nov 26 14:42:45 EST 2013 > crash>

> > And then try reading other stuff, most notably the __per_cpu_offset[] array, > like this: > > crash> rd __per_cpu_offset 256 Attached - __per_cpu_offset seems busted. Thanks, Ilya

crash> rd __per_cpu_offset 256 ffffffff81d130e0: 0000000000000000 0000000000000000 ................ ffffffff81d130f0: 0000000000000000 0000000000000000 ................ ffffffff81d13100: 0000000000000000 0000000000000000 ................ ffffffff81d13110: 0000000000000000 0000000000000000 ................ ffffffff81d13120: 0000000000000000 0000000000000000 ................ ffffffff81d13130: 0000000000000000 0000000000000000 ................ ffffffff81d13140: 0000000000000000 0000000000000000 ................ ffffffff81d13150: 0000000000000000 0000000000000000 ................ ... [ cut ] ... ffffffff81d137e0: 0000003000000001 0000000100000000 ....0........... ffffffff81d137f0: 0000000100000000 ffff880417106100 .........a...... ffffffff81d13800: ffffffff81766240 0000000000000000 @bv............. ffffffff81d13810: 0000000000000010 0000000000000000 ................ ffffffff81d13820: 0000000000000000 0000000000000000 ................ ffffffff81d13830: 0000000000000000 0000000000000000 ................ ffffffff81d13840: 0000000000000000 0000000000000000 ................ ffffffff81d13850: 0000000000000000 0000000000000000 ................ ffffffff81d13860: 000000000000000a 0000000000000078 ........x....... ffffffff81d13870: 0000000000400000 0000000a00000000 ..@............. ffffffff81d13880: 00000000ee6b2800 0000000100000001 .(k............. ffffffff81d13890: 0000000000000000 0000000000000000 ................ ffffffff81d138a0: 0000000000000000 0000000000000000 ................ ffffffff81d138b0: 0000000000000000 0000000000000000 ................ ffffffff81d138c0: 0000000000000000 0000000000000000 ................ ffffffff81d138d0: 0000000000000000 0000000000000000 ................