10.3. GDB Startup File and Utility Scripts

In addition to the add-module macro, the followin example GDB startup file contains a few other useful settings and macros, which you may want to adjust to your local environment:

set output-radix 16

target remote bdi:2001

define reset
        detach
        target remote bdi:2001
end

define add-module
        shell ~/add-symbol-file.sh $arg0
        source ~/add-symbol-file.gdb
end
document add-module
        Usage: add-module <module>

        Do add-symbol-file for module <module> automatically.
        Note: A map file with the extension ".map" must have
        been created with "insmod -m <module> > <module>.map"
        in advance.
end

The following shell script ~/add-symbol-file.sh is used to run the GDB add-symbol-file command automatically:

#!/bin/sh
#
# Constructs the GDB "add-symbol-file" command string
# from the map file of the specified kernel module.

add_sect() {
    ADDR=`awk '/^'$1' / {print $3}' $MAPFILE`
    if [ "$ADDR" != "" ]; then
        echo "-s $1 0x`awk '/^'$1' / {print $3}' $MAPFILE`"
    fi
}

[ $# == 1 ] && [ -r "$1" ] || { echo "Usage: $0 <module>" >&2 ; exit 1 ; }

MAPFILE=$1.map

ARGS="0x`awk '/^.text / {print $3}' $MAPFILE`\
 `add_sect .rodata`\
 `add_sect .data`\
 `add_sect .sdata`\
 `add_sect .bss`\
 `add_sect .sbss`\
"

echo "add-symbol-file $1 $ARGS" > ~/add-symbol-file.gdb