kernel debugging - "internal-error: inferior_thread"

[Ran Shalit <ranshalit at gmail dot com>]

Hello,

I hope someone here is familiar with kernel debugging using kgdb.
I am doing the following steps in target and host, but get error
messages in gdb:

Target
====
# echo ttyS0,9600 > /sys/module/kgdboc/parameters/kgdboc
kgdb: Registered I/O driver kgdboc.
echo g # echo g > /proc/sysrq-trigger
SysRq : DEBUG
Entering KGDB
+$#00+$md0,0114,011a,03ab,03ba,03bc,03c7,03cf,03e3,03e8,03ed,03ee,03ef,03f2,03f3,03f5,03fc#ba+$#00+$QC03fc#c0

HOST
=====
ubuntu@ubuntu-laptop:~/dtu/dtu_src/dtu/src/linux-3.14.25$
~/dtu/jjj/gdb-7.9.1/gdb/gdb -b 9600
~/dtu/dtu_src/dtu/src/linux-3.14.25/vmlinux
Python Exception <type 'exceptions.ImportError'> No module named gdb:
/home/ubuntu/dtu/jjj/gdb-7.9.1/gdb/gdb: warning:
Could not load the Python gdb module from `/home/tigran/gdb/share/gdb/python'.
Limited Python support is available from the _gdb module.
Suggest passing --data-directory=/path/to/gdb/data-directory.

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Reading symbols from
/home/ubuntu/dtu/dtu_src/dtu/src/linux-3.14.25/vmlinux...done.
(gdb) target remote /dev/ttyUSB0
Remote debugging using /dev/ttyUSB0
thread.c:89: internal-error: inferior_thread: Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) y
Command aborted.

Thanks for any suggestions,

Ran