Search icon CANCEL
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Conferences
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Linux Kernel Debugging

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

Arrow left icon
Product type Paperback
Published in Aug 2022
Publisher Packt
ISBN-13 9781801075039
Length 638 pages
Edition 1st Edition
Tools
Arrow right icon
Author (1):
Arrow left icon
Kaiwan N. Billimoria Kaiwan N. Billimoria
Author Profile Icon Kaiwan N. Billimoria
Kaiwan N. Billimoria
Arrow right icon
View More author details
Toc

Table of Contents (17) Chapters Close

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

Panic! – what happens when a kernel panics

To conquer the beast, you must first understand it. In that spirit, let's panic!

The primary panic handling code in the kernel lies here: kernel/panic.c:panic(). The panic() function – the heart of it – receives, as parameters, a variable argument list – a printf-style format specifier and associated variables (whose values will be printed):

// kernel/panic.c
/**
*  panic - halt the system
*  @fmt: The text string to print
*
*  Display a message, then perform cleanups.
*  This function never returns.
*/
void panic(const char *fmt, ...)
{ [...]

This function should (quite obviously) never be lightly invoked; calling it implies that the kernel is in an unusable, unusable state; once called, the system effectively comes to a grinding halt.

Let's panic

Here, with a view to being empirical and experimenting (on our test VM, of...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at €18.99/month. Cancel anytime