[Crash-utility] Throw read error on vmcore produced by ARM soc.

[Dave Anderson]

----- Original Message -----
> Hi, list.
> 
> I use crash-utility to analyse crash dump core from ARM soc. When I
> execute command below, I get the error "crash: read error: kernel
> virtual address: c0c1e040  type: "first vmap_area va_start"". I also
> test it by gdb. It works fine. The Linux kernel's version is v3.0.8.
> 
> hfli at pc1935:~/work/crash-utility$ ./crash vmlinux Vmcore
> 
> crash 6.1.4
> Copyright (C) 2002-2013  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) 7.3.1
> Copyright (C) 2011 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 "--host=i686-pc-linux-gnu --target=arm-elf-linux"...
> 
> crash: read error: kernel virtual address: c0c1e040  type: "first vmap_area va_start"
> 
> Errors like the one above typically occur when the kernel and memory source
> do not match.  These are the files being used:
> 
>       KERNEL: vmlinux
>     DUMPFILE: Vmcore

You've answered your own question -- you should always see errors if the vmlinux 
kernel does not match the kernel crashed system. 

If you cannot find/access the original vmlinux file that was being run
by the crashed kernel, then get the /boot/System.map file of the crashed
kernel, and enter it on the command line:

 $ crash vmlinux Vmcore System.map

The crash utility will replace all of the invalid symbol values from the
"wrong" vmlinux file with their correct values from the System.map file.

Dave