On Mon, Jan 5, 2015 at 6:49 PM, Dave Anderson
<anderson(a)redhat.com> 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.
OK, so the banner read with crash is
ffffffff818000a0: Linux version 3.13.0-39-generic (buildd@brownie) (gcc versio
ffffffff818000dc: n 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5) ) #66~precise1-Ubuntu
ffffffff81800118: SMP Wed Oct 29 09:56:49 UTC 2014 (Ubuntu 3.13.0-39.66~preci
ffffffff81800154: se1-generic 3.13.11.8)
whereas the banner from vmlinux-3.13.0-39-generic is
0a000a0: 4c69 6e75 7820 7665 7273 696f 6e20 332e Linux version 3.
0a000b0: 3133 2e30 2d33 392d 6765 6e65 7269 6320 13.0-39-generic
0a000c0: 2862 7569 6c64 6440 746f 796f 6c29 2028 (buildd@toyol) (
0a000d0: 6763 6320 7665 7273 696f 6e20 342e 382e gcc version 4.8.
0a000e0: 3220 2855 6275 6e74 7520 342e 382e 322d 2 (Ubuntu 4.8.2-
0a000f0: 3139 7562 756e 7475 3129 2029 2023 3636 19ubuntu1) ) #66
0a00100: 2d55 6275 6e74 7520 534d 5020 5475 6520 -Ubuntu SMP Tue
0a00110: 4f63 7420 3238 2031 333a 3330 3a32 3720 Oct 28 13:30:27
0a00120: 5554 4320 3230 3134 2028 5562 756e 7475 UTC 2014 (Ubuntu
0a00130: 2033 2e31 332e 302d 3339 2e36 362d 6765 3.13.0-39.66-ge
0a00140: 6e65 7269 6320 332e 3133 2e31 312e 3829 neric 3.13.11.8)
I guess I need to try to hunt down that exact vmlinux. Sigh.
Thanks,
Ilya