quick kmdb cheatsheet

quick kmdb cheatsheet

This is mainly a reference for myself since I have been playing with OpenSolaris kernel internals lately:

• To enable kmdb edit the kernel’s grub entry and append -kto it.
• Break into kmdb: f1+a
• Display status: ::status
• List available kmdb commands (and be amazed): ::dcmds
• View registers for CPU 0: ::cpuregs -c 0 and/or ::regs
• Set a breakpoint at the given symbol or address: ::bp [symbol or address]
• Set a read/write watchpoint at the given symbol or address: [symbol or address] ::wp -rw
• Display breakpoints and watchpoints: ::events
• Delete breakpoint (or watchpoint) #1: ::delete 1
• Continue execution: :c
• Next instruction, step into function calls: ::step
• Next instruction, step over function calls: ::step over
• Return from current function: ::step out
• Continue execution until the next branching instruction (only x86): ::step branch
• Disassemble around RIP: <rip::dis
• Disassemble 100 instructions starting at the given symbol or address: ::dis -n 100 [symbol or address]
• View backtrace: $C
• View IDT: ::idt
• View symbols: ::nm
• View the kernel message buffer: ::msgbuf
• Quit kmdb and reboot: ::quit

This brief cheatsheet does not do kmdb justice; it is an amazing built-in kernel debugger with countless features. For more details read the manpage.