How to fix “insmod invalid module format” for a out-of-tree linux device driver or kernel module?
If your kernel source tree matched your run time kernel, it turns out that it can be easily fixed by on debian 8:
cp /usr/src/linux-headers-3.16.0-4-amd64/Module.symvers /usr/src/linux
then make
More step by step details on debian 8:
(1) setup a build environment
apt-get install llinux-image-3.16.0-4-amd64 ( but linux-image-amd64 will not work as it will NOT update to the latest debian 8 kernel)
apt-get install linux-headers-3.16.0-4-amd64 linux-source # => linux-source-3.16.tar.xz,
cp /boot/config-3.16.0-4-amd64 /usr/src/linux/.config
make oldconfig && make prepare && make scripts
cp /usr/src/linux-headers-3.16.0-4-amd64/Module.symvers /usr/src/linux
#make && make modules ( it can generate Module.symvers, but it will take a long time)
(2) make your own kernel module
you can cd your module do the make
(3) some sample drivers at:
https://github.com/mingewang/linux_device_driver
Useful commands:
make clean
make distclean
modinfo, insmod, modprobe, dmesg
apt-get source linux-image-$(uname -r)
References:
http://www.freesoftwaremagazine.com/articles/drivers_linux
