Kernel Debugging

Purpose

Guide agents through debugging the Linux kernel: kgdb over serial or USB, kdb built-in debugger commands, ftrace and trace-cmd, kprobes and kretprobes, dynamic debug (dyndbg), crash dump analysis with crash and makedumpfile, dmesg log levels, and /proc/sys runtime tuning for debugging.

When to Use

• Kernel panic or oops with unclear stack trace
• Live debugging a kernel module or driver with kgdb
• Tracing function calls without recompiling (ftrace, kprobes)
• Enabling verbose driver logging with dyndbg
• Analyzing production crash dumps from kdump
• Tuning kernel runtime parameters for debug sessions

Workflow

1. dmesg and log levels