Writing a Simple Linux Kernel Module

In Summary :

Linux provides a powerful and expansive API for applications, but sometimes that’s not enough. Interacting with a piece of hardware or conducting operations that require accessed to privileged information in the system require a kernel module.

A Linux kernel module is a piece of compiled binary code that is inserted directly into the Linux kernel, running at ring 0, the lowest and least protected ring of execution in the x86–64 processor. Code here runs completely unchecked but operates at incredible speed and has access to everything in the system. [...]

kindly refer the following link as follow up :
https://blog.sourcerer.io/writing-a-simple-linux-kernel-module-d9dc3762c234