Loading a module file in gdb with kgdb 1.8 and earlier:

You have to explicitly load module object files in gdb when using kgdb versions 1.8 or earlier. This procedure is given below.

Procedure to be followed after running the loadmodule.sh script:
For gdb to be able to use debugging information in a module object file it has to be loaded in gdb. An object file is loaded in gdb with the gdb command add-symbol-file. The gdb script generated by loadmodule.sh script after loading a module file in the test kernel is sourced in gdb to load the module object file in gdb. To force gdb to wait for a user command, press Ctrl+C in the terminal running gdb on the development machine. Then source the file in gdb.
Following example shows the procedure. Gdb is assumed to be connected to the test kernel.

Use presses Ctrl + C.
Program received signal SIGTRAP, Trace/breakpoint trap.
breakpoint () at gdbstub.c:1153
1153    }
(gdb) source /mnt/work/gdbscripts/loadtrfs
add symbol table from file "/mnt/work/build/old-pc/trfs/modules/trfs/trfs" at
        .text_addr = 0xc1808060
        .text.lock_addr = 0xc180968c
        .rodata_addr = 0xc18097a0
        __ksymtab_addr = 0xc1809a44
        .data_addr = 0xc1809bc0
(gdb)

gdb is now all set for debugging the module trfs. We can continue here.

(gdb) c
Continuing.

Procedure to be followed for loading into gdb object files for modules not loaded using the loadmodule.sh script:
A module may be loaded either automatically or using modprobe or insmod commands. For modules which are not loaded using loadmodule.sh script, you'll have to extract module information from the target machine and give it to gdb. Use the script getsyms.sh on the target machine to get the information needed by gdb. The script is available from downloads page. Let's say a kernel has a module audio.o loaded in it. Run the script with module name as the argument as shown below.

[amitkale@askii-pc amitkale]$ bash getsyms.sh audio.o
add-symbol-file audio.o 0xd00b4060 -s .rodata 0xd00bc9bc -s .bss 0x -s .data 0xd00bf4e0
[amitkale@askii-pc amitkale]$

Supply the line printed by the script to gdb.
(gdb) add-symbol-file audio.o 0xd00b4060 -s .rodata 0xd00bc9bc -s .bss 0x -s .data 0xd00bf4e0
add symbol table from file "audio.o" at
        .text_addr = 0xd00b4060
        .rodata_addr = 0xd00bc9bc
        .bss_addr = 0x0
        .data_addr = 0xd00bf4e0
(y or n) y
Reading symbols from audio.o...done.
(gdb)

Now gdb is ready with the debugging information about the module, so you can place breakpoints in it and debug it.