kgdb debugging

[Calin Iaru]

I am trying to debug over serial console using the 2.6.27.6 kernel, but I get stuck into some issues.

On the server side:
- the kernel is built with all debug options from make menuconfig
- the grub.conf entry shows:
title CentOS (2.6.27.6) Serial Debugging
        root (hd0,0)
        kernel /vmlinuz-2.6.27.6 ro root=LABEL=/ kgdboc=ttyS0,115200
        initrd /initrd-2.6.27.6.img
On the client side, the kernel is booted with these settings:
title CentOS (2.6.27.6)
        root (hd0,0)
        kernel /vmlinuz-2.6.27.6 ro root=LABEL=/ crashkernel=128M at 16M
        initrd /initrd-2.6.27.6.img
[root at node1 linux-2.6.27.6]# stty -F /dev/ttyS0
speed 115200 baud; line = 0;
min = 0; time = 10;
-brkint -icrnl -imaxbel
-opost -onlcr
-isig -icanon -iexten -echo -echoe -echok -echoctl -echoke
- run echo -e "003" > /dev/ttyS0
- run gdb ./vmlinux
[root at node1 ~]# gdb /usr/src/linux-2.6.27.6/vmlinux
GNU gdb Red Hat Linux (6.5-25.el5_1.1rh)
Copyright (C) 2006 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"...Using host libthread_db library "/lib64/libthread_db.so.1".

(gdb) set remotebaud 115200
(gdb) target remote /dev/ttyS0
Remote debugging using /dev/ttyS0
Ignoring packet error, continuing...
Ignoring packet error, continuing...
Ignoring packet error, continuing...
Malformed response to offset query, qOffset4b


Why can't I connect with gdb and run all the break commands?