Module fails to load

[Xartos]

Describe your environment

• v4l2loopback version: master, v0.12.3, v0.12.0

• kernel version:

$ uname -a
Linux my-computer-name 4.15.0-1067-oem #77-Ubuntu SMP Mon Jan 20 09:23:07 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

• Distribution (+version):

$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 19.10
Release:	19.10
Codename:	eoan

• Compiler: gcc (Ubuntu 9.2.1-9ubuntu2) 9.2.1 20191008

Describe the problem:

After the module is built successfully and I try to load the module I get:

$ sudo modprobe v4l2loopback 
modprobe: ERROR: could not insert 'v4l2loopback': Exec format error

And the message that the kernel prints is:

[ 1667.728397] module: x86/modules: Skipping invalid relocation target, existing value is nonzero for type 1, loc 000000002619fd62, val ffffffffc0cc929d

Steps to reproduce:

1. make
2. sudo make install
3. sudo depmod -a
4. sudo modprobe v4l2loopback

Observed Results:

$ sudo modprobe v4l2loopback 
modprobe: ERROR: could not insert 'v4l2loopback': Exec format error

$ dmesg
.
.
.
[ 1667.728397] module: x86/modules: Skipping invalid relocation target, existing value is nonzero for type 1, loc 000000002619fd62, val ffffffffc0cc929d

Expected Results:

Expected the module to load correctly

Notes:

The same exact problem occurs if I download the v4l2loopback-dkms package. And secure boot is disabled.

[umlaeute]

while i acknowledge your problem, this is not fixable on the v4l2loopback side.

the issue is either

• with your kernel/kernel-headers installation (as in: they don't match), or
• with your kbuild toolchain installation (to build kernel-modules you must use the same compiler that was used for building the kernel).

see also related issues like abperiasamy/rtl8812AU_8821AU_linux#84

[Xartos]

Thanks, the link help me fix the problem!
I built it with make CC=/usr/bin/gcc-8 and now it works