How to find breakpoint if value never changes ?

Sethioz · **Posted:** 08 Apr 2010 16:23

I know that Luigi doesn't like this much, but i really need to find out how i can find the breakpoint for an address where value never changes.

usually in applications, if you need to find a breakpoint, then you simply set a breakpoint and then make application change the value, but the specific value never changes.
i can find the "breakpoint on read", but i need to find "breakpoint on write".

aluigi · **Posted:** 08 Apr 2010 17:40

ehmmm if the value never changes it means that the program:
- writes ever the same value on it, but in this case the debugger must break (ok exist some exceptions but doesn't matter now)
- just writes nothing at that address

so if the value is the same you can't break something that doesn't happen :)

Sethioz · **Posted:** 09 Apr 2010 02:39

there's been lot of games and applications which acts this way. but if i take one game as example, then it loads the value from a file (encrypted or non readable by humans) when game boots up and then it stays the same. if you find the location manually and change it, then it has effect in the game, but game never writes anything else there, however when you quit the game and restart, address is different. address also changes, when i load the game from a different save point.

so basically it changes, but address changes.
isn't it possible to do a pointer search or something ?

its weird that nobody else seem to be knowing anything about such things :S
because game trainers for example, they have found such things, so there has to be a way. i know for sure that lot of game trainers have things where value never changes, but this isnt about trainer at all, its general debugging questions, which have been bugging me for years.

aluigi · **Posted:** 09 Apr 2010 10:50

"address change" is a completely different thing than "value change".
in this case you must find the structure which points to this value (finding the one that reads it to know "how" it finds it) or the function that moves/reallocates it

Sethioz · **Posted:** 09 Apr 2010 16:42

i will bring example:
lets say that my address is "01234567" and my value is "700" (float).
i want to find breakpoint for this address, but value 700 never changes, when game loads a new area or level, then game will load this very same 700 on a new address, lets say like "76543210". so my value 700 will be stored on this address 76543210 instead of the 01234567 one.

i can easily find breakpoint on read, but i don't think it's any use ?
so how can i track it in order to find the breakpoint for the first one OR alternatively, which is as good as breakpoint, is to prevent game/application from changing the address at all.

Luigi Auriemma

How to find breakpoint if value never changes ?