Book Image

Mastering Linux Kernel Development

By : CH Raghav Maruthi
Book Image

Mastering Linux Kernel Development

By: CH Raghav Maruthi

Overview of this book

Mastering Linux Kernel Development looks at the Linux kernel, its internal arrangement and design, and various core subsystems, helping you to gain significant understanding of this open source marvel. You will look at how the Linux kernel, which possesses a kind of collective intelligence thanks to its scores of contributors, remains so elegant owing to its great design. This book also looks at all the key kernel code, core data structures, functions, and macros, giving you a comprehensive foundation of the implementation details of the kernel’s core services and mechanisms. You will also look at the Linux kernel as well-designed software, which gives us insights into software design in general that are easily scalable yet fundamentally strong and safe. By the end of this book, you will have considerable understanding of and appreciation for the Linux kernel.
Table of Contents (19 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Kernel modules


Kernel module is an easy and effective mechanism to extend the functionality of a running system without the baggage of rebuilding the whole kernel, they have been vital in ushering dynamism and scalability to the Linux operating system. Kernel modules not only satiate the extendable nature of the kernel but also usher the following functionalities:

  • Allowing kernel the ability to only keep features which are necessary, in-turn boosting capacity utilization
  • Allowing proprietary/non-GPL compliant services to load and unload
  • The bottom-line feature of extensibility of the kernel

Elements of an LKM

Each module object comprises of the init(constructor) and exit(destructor) routines. The init routine is invoked when a module is deployed into kernel address space, and the exit routine is called while the module is being removed. As the name innately suggests, the init routine is usually programmed to carry out operations and actions which are essential to set up the module body: such...