[Crash-utility] Crash Setup

[Dave Anderson]

----- "ADITYA KRISHNAN" <princeofporsche at gmail.com> wrote:

> Hi,
> Thanks for the help and guidance, I downloaded and ran the latest
> version of crash. it gives me the following output:
> 
> 
> crash 4.0-7.4
> Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Red Hat, Inc.
> Copyright (C) 2004, 2005, 2006 IBM Corporation
> Copyright (C) 1999-2006 Hewlett-Packard Co
> Copyright (C) 2005, 2006 Fujitsu Limited
> Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
> Copyright (C) 2005 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 6.1
> Copyright 2004 Free Software Foundation, Inc.
> GDB 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.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details.
> This GDB was configured as "x86_64-unknown-linux-gnu"...(no debugging
> symbols found)...
> 
> 
> crash: /boot/vmlinux-syms-2.6.16.13-xen: no debugging data available
> 
> 
> On running gdb /boot/vmlinux-syms-2.6.16.13-xen i got the following
> output:
> 
> 
> 
> GNU gdb 6.1
> Copyright 2004 Free Software Foundation, Inc.
> GDB 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.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details.
> This GDB was configured as "x86_64-unknown-linux-gnu"...(no debugging
> symbols found)...
> 
> 
> crash: /boot/vmlinux-syms-2.6.16.13-xen: no debugging data available
> 
> 
> 
> 
> GNU gdb Red Hat Linux (6.3.0.0-1.122rh)
> Copyright 2004 Free Software Foundation, Inc.
> GDB 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.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB. Type "show warranty" for
> details.
> This GDB was configured as "x86_64-redhat-linux-gnu"...
> (no debugging symbols found)
> Using host libthread_db library "/lib64/libthread_db.so.1".
> 
> 
> (gdb)
> 
> 
> The common point being debug info was not found. But when running
> crash it says GDB was configured as "x86_64-unknown-linux-gnu" and
> when running only gdb it says GDB was configured as
> "x86_64-redhat-linux-gnu"

The lack of debuginfo is the only issue.  The "configured as..." message
is irrelevant, as long as the machine type x86_64 is correct. 

> 
> This may be a stupid question... but am I right in assuming that crash
> will now run if I compile xen again with -g option ?

That should be correct.  I don't know how your "vmlinux-syms-2.6.16.13-xen"
kernel was built, but it's surprising to me that it's got the "syms" string
in its name, but was built without -g.  But the "(no debugging symbols found)"
message from gdb is proof of that.  

When xensource builds their hypervisor binary, it's debuginfo-full version
is called "xen-syms".  I would have thought the same would apply to your vmlinux
kernel, but I don't know what distribution/procedure is responsible for creating
your vmlinux file?
  
Dave