This is the code repository for Linux Kernel Programming, Second Edition, published by Packt.

A comprehensive and practical guide to kernel internals, writing modules, and kernel synchronization

The author of this book is - Kaiwan N. Billimoria

The 2nd Edition of Linux Kernel Programming is an updated, comprehensive guide for new programmers to the Linux kernel. This book uses the recent 6.1 Long-Term Support (LTS) Linux kernel series, which will be maintained until Dec 2026, and also delves into its many new features. Further, the Civil Infrastructure Project has pledged to maintain and support this 6.1 Super LTS (SLTS) kernel right until August 2033, keeping this book valid for years to come!

You’ll begin this exciting journey by learning how to build the kernel from source. In a step by step manner, you will then learn how to write your first kernel module by leveraging the kernel’s powerful Loadable Kernel Module (LKM) framework. With this foundation, you will delve into key kernel internals topics including Linux kernel architecture, memory management, and CPU (task) scheduling. You’ll finish with understanding the deep issues of concurrency, and gain insight into how they can be addressed with various synchronization/locking technologies (e.g., mutexes, spinlocks, atomic/refcount operators, rw-spinlocks and even lock-free technologies such as per-CPU and RCU).

By the end of this book, you’ll have a much better understanding of the fundamentals of writing the Linux kernel and kernel module code that can straight away be used in real-world projects and products.

• Configure and build the 6.1 LTS kernel from source
• Write high-quality modular kernel code (LKM framework) for 6.x kernels
• Explore modern Linux kernel architecture
• Get to grips with key internals details regarding memory management within the kernel
• Understand and work with various dynamic kernel memory alloc/dealloc APIs
• Discover key internals aspects regarding CPU scheduling within the kernel, including cgroups v2
• Gain a deeper understanding of kernel concurrency issues
• Learn how to work with key kernel synchronization primitives

This book, LKP 2E, is an ideal guide to Linux kernel development for programmers new to it, as well as for experienced developers. It incorporates a judicious mix of theory and practice, with more focus on practical aspects. It deliberately moves away from bland and generic 'OS theory' topics and instead covers them where required from the clear and distilled viewpoint of implementation details in a real, live OS - Linux. The book's chapters are as follows:

1. Linux Kernel Programming – A Quick Introduction
2. Building the 6.x Linux Kernel from Source – Part 1
3. Building the 6.x Linux Kernel from Source – Part 2
4. Writing Your First Kernel Module – Part 1
5. Writing Your First Kernel Module – Part 2
6. Kernel Internals Essentials – Processes and Threads
7. Memory Management Internals – Essentials
8. Kernel Memory Allocation for Module Authors – Part 1
9. Kernel Memory Allocation for Module Authors – Part 2
10. The CPU Scheduler – Part 1
11. The CPU Scheduler – Part 2
12. Kernel Synchronization – Part 1
13. Kernel Synchronization – Part 2

If you feel this book is for you, get your copy today!

With the following software and hardware list you can run all code files present in the book.

These are the Linux platforms upon which the book's codebase has been developed and tested:

• x86_64 Ubuntu 22.04 LTS native and guest OS
• x86_64 Ubuntu 23.04 LTS native and guest OS
• x86_64 Fedora 38 (and 39) on a native and guest OS
  • All guest OS's have been run upon the host Oracle VirtualBox 7.0 hypervisor
• ARM Raspberry Pi 4 Model B (64-bit, running both its “distro” kernel as well as our custom 6.1 kernel); lightly tested

• page 9:
  • The phrase 'the 6.1 kernel is a Long-Term Stable (LTS) version', should be 'the 6.1 kernel is a Long-Term Support (LTS) version'.

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We also provide a PDF file that has color images of the screenshots/diagrams used in this book at GraphicBundle

Kaiwan N. Billimoria taught himself BASIC programming on his dad's IBM PC back in 1983. He was programming in C and Assembly on DOS until he discovered the joys of Unix, and by around 1997, Linux! Kaiwan has worked on many aspects of the Linux system programming stack, including Bash scripting, system programming in C, kernel internals, device drivers, and embedded Linux work. He has actively worked on several commercial/FOSS projects. His contributions include drivers to the mainline Linux OS and many smaller projects hosted on GitHub. His Linux passion feeds well into his passion for teaching these topics to engineers, which he has done for well over two decades now. He's also the author of Hands-On System Programming with Linux, Linux Kernel Programming (and its Part 2 book) and Linux Kernel Debugging. It doesn't hurt that he is a recreational ultrarunner too.

• The Software Developer’s Guide to Linux
• Mastering Linux Security and Hardening - Third Edition