Debugging kernel code

You can use kgdb for source-level debugging, in a manner similar to remote debugging with gdbserver. There is also a self-hosted kernel debugger, kdb, that is handy for lighter-weight tasks such as seeing whether an instruction is executed and getting the backtrace to find out how it got there. Finally, there are kernel Oops messages and panics, which tell you a lot about the cause of a kernel exception.

Debugging kernel code with kgdb

When looking at kernel code using a source debugger, you must remember that the kernel is a complex system, with real-time behaviors. Don't expect debugging to be as easy as it is for applications. Stepping through code that changes the memory mapping or switches context...