Cheat Engine

fakerlol · Newbie cheater Reputation: 0 Joined: 06 Feb 2016 Posts: 21

So I've been using CheatEngine for some time now and was mesmerized by the Mono utilities which were introduced some years ago.

I really love the freedom this gives to me, as I can not only change minor things, but can even add whole modifications of the game without having to spend hours trying to figure out where to hook into and what how methods are linked together.

As far as I can recall, I was able to set a breakpoint somewhere with Mono features enabled (and seeing the labels instead of addresses) and use the debugger to step within the code.

For at least 2 major updates it won't work for me, at all. Whenever I use the debugger to step withint the code or "find out what writes to an adress", CE disables the Mono features with a LUA-Error ("Failed to launch..."), leaving me with boring hexadecimal addresses instead of labels.
With the latest release (v7.2) it outright hangs up for several seconds up to a minute before displaying an error.

Isn't the Mono features supposed to work with the (VEH) debugger or am I just the odd one out?
This really kills my joy working with mono-code, as I have to re-enable Mono features every time I "deep-dived" into the code Sad

Dark Byte · Posted: Wed Nov 25, 2020 2:04 pm Post subject:

When you look at an address, CE will ask the mono process what the name of that address is
If it takes longer than 3 seconds, ce will disconnect from the mono system to prevent a full freeze

When a breakpoint hits, CE also asks that mono process what the name is, but since the target process is frozen, it will not respond, so therefore it will disconnect.

In the previous version where CE didn't disconnect, CE would try not show any symbols at all if any breakpoint is set or the target is halted on a breakpoint, but since sometimes a breakpoint hits because the address is fetched, that would cause CE to freeze infinitely, so I went for a timeout system instead.
At least this way you don't have to restart CE when a breakpoint hits

But try https://raw.githubusercontent.com/cheat-engine/cheat-engine/master/Cheat%20Engine/bin/autorun/monoscript.lua
it shouldn't disconnect that quickly (Just not show any symbols when debugging, and IF the mono dll is the one triggering the BP, still disconnect)

fakerlol · Newbie cheater Reputation: 0 Joined: 06 Feb 2016 Posts: 21

Dark Byte · Posted: Wed Nov 25, 2020 4:58 pm Post subject:

Sorry, that script had a typo. Try again

the 6.x versions would never show symbols, and even then still sometimes end in a complete lockout of CE as it would freeze if a breakpoint did happen. If it worked, it'd likely be .net or a .PDB with data, but not mono

You just need to understand that it's literally impossible to query mono routines while the target is suspended. Maybe in some rare cases where you use VEH debug and the collector thread is not suspended it may work, but modern versions of mono are more thread safe and will apply locks to certain structures, so asking for a name for an address will cause mono to acquire an method lock, which will then have to wait for the current mono method to finish executing, so infinite lock if that method is the one currently halted on a breakpoint and that address's name is being queried

fakerlol · Newbie cheater Reputation: 0 Joined: 06 Feb 2016 Posts: 21

Damn, now that you mention it, I had .pdb's or native .net applications when using the debugger, so it seemed to work flawlessly.
Seems that I confused .net with mono, so your explanation does make a lot of sense.

Yeah, back to learning more about the backend I guess.
Thanks for your fast replies DB!