x64dbgpy: application unresponsive when trying to automate inside breakpoint callback

Question

When a breakpoint callback is triggered trying to automate the debugger inside the callback causes the application to become unresponsive. x64dbg continues functioning but the application itself doesn't resume execution.

This is only happening when the functions are called inside the BP callback.

Script:

from x64dbgpy import *

def handle():
    pluginsdk.Run()


Breakpoint.add(0x81755, handle)

Calling any function such as pluginsdk.StepOver, etc also causes the freeze.

Does x64dbgpy not support automating the debugger inside breakpoint callbacks? Or am I doing something wrong? Suggestions would be great.

Answer 1

Currently it is not supported to do debug automation in callbacks. This is related to the threading model and is further explained at https://x64dbg.com/blog/2016/10/20/threading-model.html, which links to some older resources.

Recently there was an interesting development though, because it became possible to automate in the debug callbacks with x64dbg’s built in scripting language (which I do not recommend). The idea now is to port this idea to a C api, which can then be used by plugins like x64dbgpy or x64dbgPlaytime.