melvinvarkey / voltron

A hacky debugger UI for hackers

Voltron

Voltron is an extensible debugger UI for hackers. It allows you to attach utility views running in other terminals to your debugger (LLDB or GDB), displaying helpful information such as disassembly, stack contents, register values, etc, while still giving you the same debugger CLI you're used to. You can still have your pimped out custom prompt, macros, plugins, terminal colour scheme - whatever you're used to - but you get the added bonus of a sweet customisable heads-up display.

Voltron also provides a platform on which to build your own UI views, requesting and processing data from the debugger back end to suit your own requirements. To this end, Voltron provides (and uses internally) a JSON API available over UNIX domain sockets, TCP sockets and an HTTP server.

Support

voltron is built primarily for LLDB. GDB version 7 and later and VDB are both supported.

The following architectures are supported:

	lldb	gdb	vdb
x86	✓	✓	✓
x86_64	✓	✓	✓
arm	✓	✓	✓
arm64	✓	x	x
powerpc	x	✓	x

Installation

A standard python setup script is included.

# python setup.py install

This will install the voltron egg wherever that happens on your system, and an executable named voltron to /usr/local/bin/.

Quick Start

1. Configure your debugger to load Voltron when it starts by sourcing the dbgentry.py entry point script. The full path will be inside the voltron egg. For example, on OS X it might be /Library/Python/2.7/site-packages/voltron-0.1-py2.7.egg/dbgentry.py.

   For LLDB:

    command script import /path/to/voltron/dbgentry.py
   

   For GDB:

    source /path/to/voltron/dbgentry.py
    voltron init
   

   This part can go in your .lldbinit or .gdbinit so it's automatically executed when the debugger starts.

2. Start your debugger. On LLDB you need to call voltron init after you load the inferior, as a target must be loaded before Voltron's hooks can be installed. This means voltron init cannot be called from .lldbinit the way it can from .gdbinit. Hopefully this will be remedied with a more versatile hooking mechanism in a future version of LLDB (this has been discussed with the developers).

    $ lldb file_to_debug
    (lldb) voltron init
   

3. In another terminal (I use iTerm panes) start one of the UI views

    $ voltron view register -v
    $ voltron view stack
    $ voltron view disassembly
    $ voltron view backtrace
    $ voltron view command 'reg read'
   

4. Set a breakpoint and run your inferior. Once the inferior has started and the debugger has stopped (either because you interrupted it or because it hit a breakpoint) the views will update.

    (*db) b main
    (*db) run
   

5. The debugger should hit the breakpoint and the views will be updated. A forced update can be triggered with the following command:

    (lldb) voltron stopped
   

Documentation

See the wiki on github.

Bugs

See the issue tracker on github.

License

This software is released under the "Buy snare a beer" license. If you use this and don't hate it, buy me a beer at a conference some time. This license also extends to other contributors - richo definitely deserves a few beers for his contributions.

Credits

Thanks to Azimuth Security for letting me spend time working on this.

Props to richo for all his contributions to Voltron.

fG!'s gdbinit was the original inspiration for this project.

Thanks to Willi for implementing the VDB support.