Lua and random WoW crashes

[jockel]

Hello there,

since patch 3.3.5 I'm getting some problems with my lua handler.
First of all my lua handler is working in the wow process (as injected library) and communicates with my main program via IPC.

With patch 3.3.5 the problems began, Wow is crashing randomly when executing lua commands. There is no pattern, sometimes after 10 executions sometimes after 200.

There is also no Wow crashlog.




Any ideas on how I may find out whats causing the crash?

[DrGonzo]

New antidebug? Are you using debug registers, or attaching to wow process or anything debug related? It'll generally crash out wow without a wowerror message (unless its a single step exception).

[caytchen]

I guess you invoke the lua stuff from an extra thread, the one that also handles IPC communication? If so, stop assuming the game api is thread-safe.

[Cypher]

You need to call FrameScript__Execute from the game's main thread.

[jockel]

Sorry forgot to say that I'm hooking endscene, and all lua functions are being executed in the hook (therefore in the mainthread).

@FearAndLawyering
No debuggers attached, I'm just injecting the library and open the process with read/write rights.

Since the crashes are totally random, I can't figure out a way to solve it.
(Any ideas on how I should manage to find the issue?)

[caytchen]

Then you should probably start attaching a debugger or at least using the JIT one.

[Sednogmah]

Just a blind assumption... If you're interfacing Lua via lua_pcall and manage the Lua stack on your own: Are you clearing the stack with lua_remove() after every call? WoW will crash sooner or later if you don't remove all the return values.

[jockel]

I'm using a luacallback with lua_tostring and lua_gettop to get the returnvalues.


I attached a debugger to see where it's crashing:

When it crashes the debugger halts at:


after clicking "continue executing", we are here, and Wow exits:

[Cypher]

Post your code imo. It's not easy to debug based on guess-work, lol.