how to locate linux kernel module module_init(function), function offset from ELF header?

Question

The header is self explanatory but to explain my self better. I have an ELF binary - loadable kernel module, compiled with symbols. I want to know how to locate the offset of the init function. Can i find this info using "readelf" ?

Thanks,

Answer 1

To read with readelf the parameter is "-s":

 Options are:
    -a --all               Equivalent to: -h -l -S -s -r -d -V -A -I
    -h --file-header       Display the ELF file header
    -l --program-headers   Display the program headers
        --segments          An alias for --program-headers
    -S --section-headers   Display the sections' header
       --sections          An alias for --section-headers
    -g --section-groups    Display the section groups
    -t --section-details   Display the section details
    -e --headers           Equivalent to: -h -l -S
    -s --syms              Display the symbol table
       --symbols           An alias for --syms
    --dyn-syms             Display the dynamic symbol table
    -n --notes             Display the core notes (if present)

So, with readelf -s module.ko is enough to read the symbols.

Answer 2

First disassemble your module

objdump -xDsl module.ko > disassemble.txt

Then edit the file and search for section init. It look like this:

Disassembly of section .init.text:

002bdb01 : init_fct():