Book Image

Linux Kernel Programming

By : Kaiwan N. Billimoria
Book Image

Linux Kernel Programming

By: Kaiwan N. Billimoria

Overview of this book

Linux Kernel Programming is a comprehensive introduction for those new to Linux kernel and module development. This easy-to-follow guide will have you up and running with writing kernel code in next-to-no time. This book uses the latest 5.4 Long-Term Support (LTS) Linux kernel, which will be maintained from November 2019 through to December 2025. By working with the 5.4 LTS kernel throughout the book, you can be confident that your knowledge will continue to be valid for years to come. You’ll start the journey by learning how to build the kernel from the source. Next, you’ll write your first kernel module using the powerful Loadable Kernel Module (LKM) framework. The following chapters will cover key kernel internals topics including Linux kernel architecture, memory management, and CPU scheduling. During the course of this book, you’ll delve into the fairly complex topic of concurrency within the kernel, understand the issues it can cause, and learn how they can be addressed with various locking technologies (mutexes, spinlocks, atomic, and refcount operators). You’ll also benefit from more advanced material on cache effects, a primer on lock-free techniques within the kernel, deadlock avoidance (with lockdep), and kernel lock debugging techniques. By the end of this kernel book, you’ll have a detailed understanding of the fundamentals of writing Linux kernel module code for real-world projects and products.
Table of Contents (19 chapters)
1
Section 1: The Basics
6
Writing Your First Kernel Module - LKMs Part 2
7
Section 2: Understanding and Working with the Kernel
10
Kernel Memory Allocation for Module Authors - Part 1
11
Kernel Memory Allocation for Module Authors - Part 2
14
Section 3: Delving Deeper
17
About Packt

The LDV - Linux Driver Verification - project

The Russian Linux Verification Center, founded in 2005, is an opensource project; it has specialists in, and thus specializes in, automated testing of complex software projects. This includes comprehensive test suites, frameworks, and detailed analyses (both static and dynamic) being performed on the core Linux kernel as well as on the primarily device drivers within the kernel. This project puts a great deal of focus on the testing and verification of kernel modules as well, which many similar projects tend to skim.

Of particular interest to us here is the Online Linux Driver Verification Service page (http://linuxtesting.org/ldv/online?action=rules); it contains a list of a few verified Rules (Figure 1.11):

Figure 1.11 – Screenshot of the 'Rules' page of the Linux Driver Verification (LDV) project site

By glancing through these rules, we'll be able to not only see the rule but also instances of actual cases where these rules were violated by driver/kernel code within the mainline kernel, thus introducing bugs. The LDV project has successfully discovered and fixed (by sending in patches in the usual manner) several driver/kernel bugs. In a few of the upcoming chapters, we shall mention instances of these LDV rule violations (for example, memory leakage, Use After Free (UAF) bugs, and locking violations) having been uncovered, and (probably) even fixed.

Here are some useful links on the LDV website: