How to debug the init_module() call of a Linux kernel module?

I am doing first steps into Linux kernel development. I have some code producing a .ko kernel module that I install with insmod. I would like a way to debug what happens when I install the module but I am facing some difficulties.

1. I need to debug the call to init_module. Is this function called when I run insmode ?

2. I try to use insmod "/my/url/fil.ko" -m to debug what happens but each time I got error -1 Unknown symbol in module while in /cat/log/message I can see the error unknown parameter -m

3. Do you know if there is a way to debug with GDB?

Answer

Yes, the init_module function gets called as soon as you load it to the kernel using insmod. You can just add a line of printk and verify it being printed as soon as you insert the module.

You cannot pass a parameter such as -m to debug the kernel module.

You can only pass parameters that are intended to be handled within the kernel module that you have written, using MODULE_PARAMS.