You're reading from Linux Kernel Debugging Leverage proven tools and advanced techniques to effectively debug Linux kernels and kernel modules

Product type Paperback

Published in Aug 2022

Publisher Packt

ISBN-13 9781801075039

Length 638 pages

Edition 1st Edition

Tools

Linux

Concepts

System Administration

Author (1):

Kaiwan N. Billimoria

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Table of Contents (17) Chapters

Preface

1. Part 1: A General Introduction and Approaches to Kernel Debugging

2. Chapter 1: A General Introduction to Debugging Software FREE CHAPTER

3. Chapter 2: Approaches to Kernel Debugging

4. Part 2: Kernel and Driver Debugging Tools and Techniques

5. Chapter 3: Debug via Instrumentation – printk and Friends

6. Chapter 4: Debug via Instrumentation – Kprobes

7. Chapter 5: Debugging Kernel Memory Issues – Part 1

8. Chapter 6: Debugging Kernel Memory Issues – Part 2

9. Chapter 7: Oops! Interpreting the Kernel Bug Diagnostic

10. Chapter 8: Lock Debugging

11. Part 3: Additional Kernel Debugging Tools and Techniques

12. Chapter 9: Tracing the Kernel Flow

13. Chapter 10: Kernel Panic, Lockups, and Hangs

14. Chapter 11: Using Kernel GDB (KGDB)

15. Chapter 12: A Few More Kernel Debugging Approaches

16. Other Books You May Enjoy

Kprobes – limitations and downsides

We do realize that no single feature can do anything and everything – in the words of Frederick J Brooks (in his incomparable book The Mythical Man Month): "there is no silver bullet".

As we've seen, certain kernel/module functions cannot be probed, including the following:

Functions marked with the __kprobes or nokprobe_inline annotation.
Functions marked via the NOKPROBE_SYMBOL() macro.
The pseudofile /sys/kernel/debug/kprobes/blacklist holds the names of functions that can't be probed. (Incidentally, our ch4/kprobes/4_kprobe_helper/kp_load.sh script checks this against the function attempting to be probed). Also, some inline functions might not be able to be probed.

There's more to note on the point of using k[ret]probes on production systems due to the possibility of stability issues; the next section throws some light on this.