In the third part of this guide we will explain what system calls actually are and how they work under the Linux kernel. Furthermore, we will also try to write a simple syscall that will greet the user. Do note that this article is part of a series of guides on kernel hacking for Linux, you can find the rest of the guide here: Part one: Introduction to the Linux kernel architecture; Part two: Building a device driver from scratch; Part three(this one): Introduction to syscalls, how to create a new syscall; Be sure to read the previous two before starting with this one.

Welcome back to the second part of this series of tutorial on Linux kernel hacking. Below, you will find the links to the other parts of the series. If you have not read the first part yet, make sure to start from there. Part one: Introduction to the Linux kernel architecture; Part two(this one): Building a device driver from scratch; Part three: Introduction to syscalls, how to create a new syscall; In this article, we will try to extend our knowledge about Linux programming by building a kernel module that actually does something.

This guide will walk you through a brief introduction on how to get started with kernel hacking. The guide is split into three parts, each one covering one of the following topic: Part one(this one): Introduction to the Linux kernel architecture; Part two: Building a device driver from scratch; Part three: Introduction to syscalls, how to create a new syscall; While this guide aims to provide a beginner-friendly resource to get started on kernel hacking, I take for granted some prior knowledge: