Essential Tools for Linux Device Drivers Development

Debugging Linux Drivers in Kernel Space

Writing kernel-space code requires precise tracing and memory safety tools. A single null dereference inside a character driver crashes the entire system with a kernel panic.

Must-Have Toolchain

1. **Ftrace & Trace-cmd**: Trace kernel function calls with zero overhead. 2. **KGDB & GDB over Serial**: Step-by-step kernel debugging with breakpoints. 3. **KASAN (Kernel Address Sanitizer)**: Catch out-of-bound memory accesses and use-after-free bugs.

# Enabling ftrace for driver function tracing
echo function > /sys/kernel/debug/tracing/current_tracer
echo my_custom_driver_ioctl > /sys/kernel/debug/tracing/set_ftrace_filter
cat /sys/kernel/debug/tracing/trace

Summary Checklist - Always test drivers with KASAN compiled into the test kernel. - Use dynamic debug (`pr_debug`) instead of hardcoding `printk` statements.