dbg

A toy debugger. Just started out goofing around with ptrace(2) and this came out the other end.

Currently works on:

• CPUs: x86/amd64 only at the moment.

• Operating Systems: Linux, FreeBSD, OpenBSD, macOS.

Commands are inspired by windbg. Currently:

• bp - Create breakpoint

• bl - List breakpoints

• bc - Clear breakpoint

• db, dw, dd, dq - Dump memory in 8, 16, 32, and 64 bit quantities respectively

• eb, ew, ed, eq - Edit memory in the same units.

• .detach - Detach the target

• t - Single instruction step

• g - Go (continue execution)

• k - Stack trace

• r - Print or edit registers

• u - Disassemble

• q - Quit the process & debugger

TODO

• Symbolication, DWARF, etc.
• Threads.
• More CPU arches and operating systems:
  • Windows? The APIs are pretty clean.
  • ARM? RISC-V?
  • Dead platforms? (Solaris, SPARC, PowerPC?)

Building

$ git submodule update --init
$ make   # (or gmake on some systems, eg. *BSD)

For x86 you will need python2 on the path.

For macOS you will need a code sign identity, as Apple does not allow unsigned apps to attach for debugging.

The app requires libreadline.