So here I am trying to write about how one can apply gdb to a running
kernel, and I'd like to tell people how to debug loadable modules.  Only
with the 2.6 module loader, there's no way to find out where the various
sections in the module image ended up, so you can't do much.  This patch
attempts to fix that by adding a "sections" subdirectory to every module's
entry in /sys/module; each attribute in that directory associates a
beginning address with the section name.  Those attributes can be used by a
a simple script to generate an add-symbol-file command for gdb, something
like:

#!/bin/bash
#
# gdbline module image
#
# Outputs an add-symbol-file line suitable for pasting into gdb to examine
# a loaded module.
#
cd /sys/module/$1/sections
echo -n add-symbol-file $2 `/bin/cat .text`

for section in .[a-z]* *; do
    if [ $section != ".text" ]; then
	echo  " \\"
	echo -n "	-s" $section `/bin/cat $section`
    fi
done
echo

Currently, this feature is absent if CONFIG_KALLSYMS is not set.  I do
wonder if CONFIG_DEBUG_INFO might not be a better choice, now that I think
about it.  Section names are unmunged, so "ls -a" is needed to see most of
them.
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>