I want to build a kernel module for a custom Debian derivative.
I do have the kernel headers and make seemed to work at first shot. But when I did insmod the module, it crashed.

BTW: In order to not screw up the target system, I built in a Docker container on the target system.

I found that the contents of the .config file in the kernel-headers folder do not match the contents of /proc/config.gz of the target system.

My question is: When I copy the configuration from /proc/config.gz (from the target) to .config in the kernel-headers folder (inside the container where I build), what do I do next to "apply" the changes before building my module?

I admit, I am a bit confused by all the make targets available and for a while I was trying things google found for me, like:
make headers_check
make headers_install
make scripts

This combination finally worked - at least the module seems to work without crashing.

But I am unsure whether this was the proper way of doing things or just luck with who-knows-what-side-effects lurking behind the curtains!

What would be the correct way?
Thanks a lot!

Hm. looks like we have Carlsbad in California, but also we have Karlsbad in Europe.
You need to use modprobe instead of insmod.
What you posted is not enough to answer. It depends on a lot of things, especially would be nice to know why did it crash. What steps did you make before?
Anyway, I would start here: https://wiki.debian.org/Modules (you can find additional links at the bottom of this page). But probably you know it already.

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Trying random things on google works for some things, but not the best idea for kernel modules. Best is to use the directions in the kernel source.

https://elixir.bootlin.com/linux/lat...ld/modules.rst

"make help" prints a description of the kernel make targets.

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Thanks guys!
It's Carlsbad in California BTW. But I'm back in Europe since 2011 though... But not in Karlsbad...