[SOLVED] Provide kernel source for 4.15.0-37 generic kernel

vini_gajjar

Hello folks,
I can see here https://wiki.up-community.org/Linux_Kernels that the kernel sources for 4.9 and 4.12 are provided, but not for 4.15.
It is much required to modify few modules and drivers and to recompile them.
Does someone know where to find it .
the kernel source for 4.15.0-37 generic is found no where on kernel.org

DCleri

From your UP board, once you have installed the UP specific Ubuntu Kernel 4.15: https://wiki.up-community.org/Ubuntu

sudo apt-get source linux-hwe

Also you can find instructions to build the kernel using Ubuntu tools here:
https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel#Build_Environment

vini_gajjar

@DCleri
Thank you for your valuable repsonse.
Just another question.
Is the kernel source that is downloaded using above command specific for up board or is it generic ??
Moreover, if I pick a specific ".ko" module from this new source and copy it to /lib/modules/4.15.0-37-generic/kernel/drivers/... , will it be completely okay and not cause me version mismatch error ??

ccalde

Hi @vini_gajjar

The kernel is a generic version for all UP family boards. The drivers are adapted for each board specially.

You should be able to send any module to /lib/modules without problems.

You can try these steps:
sudo cp .ko /lib/modules/4.15.0-37-generic/kernel/drivers/
sudo echo '' | sudo tee -a /etc/modules
sudo depmod -a 4.15.0-37-generic

vini_gajjar

hello @ccalde ,
I downloaded kernel source using "sudo apt-get source linux-hwe", I performed following steps entering the root of kernel source.

make mrproper
cp /boot/config-4.15.0-37-generic .config
make oldconfig
make prepare
make scripts
make SUBDIRS=$drivers/usb/gadget/legacy modules
cp drivers/usb/gadget/legacy/g_mass_storage.ko /lib/modules/4.15.0-37-generic/kernel/drivers/usb/gadget/legacy/
depmod -a 4.15.0-37-generic
modprobe g_mass_storage file= removable=1

This caused an error as "version magic 4.15.18 SMP mod_unload should be 4.15.0-37-generic SMP mod_unload"

For this I modified a line in /usr/src/linux-hwe-4.15.0/include/generated/utsrelease as,
define UTS_RELEASE "4.15.18" to #define UTS_RELEASE "4.15.0-37-generic"

Now the module can be successfully loaded

The reason to post this comment is to verify whether the above steps are valid ??

vini_gajjar

@DCleri Can you please check with the above comment

ccalde

Hi @vini_gajjar ,

Yes, that makes sense for me!

vini_gajjar

Thank you folks. Your comments helped me a lot and may help many.

vini_gajjar

@DCleri @ccalde
Folks, I need a help with this.
I compiled the module and loaded as per above discussions
But after loading the module, when check kernel logs using dmesg, I read this.

Loading Out-of-Tree kernel module taints kernel.
Module verification failed - Signature mismatch taints kernel

Although modified module is loaded successfully and the system is stable.
Is the above message a serious problem
Is kernel tainting unacceptable

I'll appreciate if you can help me with this

ccalde

Hi @vini_gajjar

That shouldn't be an issue for your kernel.
It seems a warning message about the signature for verification, due to the manual loading.