Book Image

Linux Kernel Debugging

By : Kaiwan N. Billimoria
Book Image

Linux Kernel Debugging

By: Kaiwan N. Billimoria

Overview of this book

The Linux kernel is at the very core of arguably the world’s best production-quality OS. Debugging it, though, can be a complex endeavor. Linux Kernel Debugging is a comprehensive guide to learning all about advanced kernel debugging. This book covers many areas in-depth, such as instrumentation-based debugging techniques (printk and the dynamic debug framework), and shows you how to use Kprobes. Memory-related bugs tend to be a nightmare – two chapters are packed with tools and techniques devoted to debugging them. When the kernel gifts you an Oops, how exactly do you interpret it to be able to debug the underlying issue? We’ve got you covered. Concurrency tends to be an inherently complex topic, so a chapter on lock debugging will help you to learn precisely what data races are, including using KCSAN to detect them. Some thorny issues, both debug- and performance-wise, require detailed kernel-level tracing; you’ll learn to wield the impressive power of Ftrace and its frontends. You’ll also discover how to handle kernel lockups, hangs, and the dreaded kernel panic, as well as leverage the venerable GDB tool within the kernel (KGDB), along with much more. By the end of this book, you will have at your disposal a wide range of powerful kernel debugging tools and techniques, along with a keen sense of when to use which.
Table of Contents (17 chapters)
1
Part 1: A General Introduction and Approaches to Kernel Debugging
4
Part 2: Kernel and Driver Debugging Tools and Techniques
11
Part 3: Additional Kernel Debugging Tools and Techniques

Chapter 2: Approaches to Kernel Debugging

Even a casual perusal of topics related to kernel debugging will quickly have you realize that there are many approaches to it, and correspondingly, many tools and techniques that can and are brought to bear on the problem. In this relatively short chapter, we'll first check out some ways of classifying bugs by type. Classifying defects or bugs by type will help you gain a high-level understanding of them and where they fall, and at times overlap. We shall classify bugs by various types or views: the classic view – by memory issues, the security-related view, and finally, by typical issues caused within the Linux kernel.

Next, we consider why there are various approaches to kernel debugging, and then summarize exactly what these approaches are and when it's generally appropriate to use which approach. These topics will help lay the foundation for the remainder of the book, where we'll delve into learning how to employ...