newly created module works well, but depmod results in errors

From: roadster (
Date: 02/10/04

Date: 10 Feb 2004 05:06:18 -0800


I've created a new device driver (my first;-)). I managed to build it
without any warnings and I was able to test it after installation.
Everything goes OK.

The driver is taken from the 'linux device drivers' book (second
edition), so I'm pretty sure that the code is OK. It is the scull char

However, a day after the tests, I noticed following error while
starting up linux (it is RH9, version 2.4).

Checking module dependencies :

depmod : *** Unresolved symbols in /lib/modules/2.4.20-8/misc/scull.o

So although the tests are OK it seems that there is still something
wrong. I issued the depmod cmd. myself later on in order to see which
symbols aren't known.

/sbin/depmod -e results in :

depmod: *** Unresolved symbols in /lib/modules/2.4.20-8/misc/scull.o
depmod: __generic_copy_from_user
depmod: kmalloc
depmod: unregister_chrdev
depmod: register_chrdev
depmod: kfree
depmod: printk
depmod: __generic_copy_to_user

These are all kernel functions and I'm sure that the according kernel
headers are included (otherwise it wouldn't build).

I don't get this message while linking the driver, so at that time it
seems that these functions are all known.

The question is of course why I still get these dependency errors
after executing the depmod command?