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

An introduction to kernel tracing with LTTng and Trace Compass

The Linux Trace Toolkit – next generation (LTTng) is a powerful and popular tracing system for the Linux kernel as well as userspace apps and libraries; it's open source, released under the Lesser GPL (modules and libraries), the GPL (tooling), and some components under the MIT license. Its original version (LTT) dates back to 2005, and LTTng is actively maintained. It has made a name for itself in helping track down performance and debug issues on multicore parallel and real-time systems. (Here, we're using the latest stable version at the time of writing – v2.13.)

The LTTng website (https://lttng.org/) does an excellent job documenting all aspects (learn what exactly tracing is at https://lttng.org/docs/v2.13/#doc-what-is-tracing). Due to space constraints, we shall simply refer you to the appropriate links. To install LTTng, please see this link: https://lttng.org/docs/v2.13/#doc-installing...