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mArTi

(SOLVED) ODBG2 plugins: permanent breakpoint

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mArTi

Hello !

I'm currently writing some ollydbg plugin and I'm trying to put some breakpoint on a few external functions, because I need to get the passed values to those at each hit.

 

I'm using this snippet to set the breakpoint :

t_module* module = Findmodulebyname(L"(nameofthemodule)");wchar_t* error = L"Error";ulong funcaddress = 0;FindaddressW(L"(function name)",module,&funcaddress,error);Setint3breakpoint(funcaddress,BP_TEMP,0,0,0,BA_PERMANENT|BA_PLUGIN ,NULL,NULL,NULL);
But, even with a BA_PERMANENT (even with changing ODBG2_Plugintempbreakpoint to ODBG2_Pluginexception to catch the bp), the breakpoints are deleted... meaning I only can break at those functions once, at the first hit.

 

Do you have an idea on how to bp on *every* call to those functions (and not getting the bp deleted at each hit) ?

 

Many thanks for your answers !

Edited by mArTi (see edit history)

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mrexodia

intercept the code that deletes this breakpoint (should be possible in plugin interface) and re-set it :)

greetings

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mArTi

Re-setting the breakpoint each time would slow a lot the debugging (the breakpoint is deleted right after the callback function has been deleted, even if flag BA_PERMANENT has been set). Got any idea that would not slow that much, and that would permit to break each time at those functions ?


 


Thank you for your answer ;)


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mrexodia

ehm, you could hook the remove_breakpoint function to not remove your breakpoint (just redirect, check addr, return if it's one of yours, continue if it's another one)...

I dont know much about the olly engine so I really can't tell.. maybe email oleh for some help (he said he would answer emails regarding the new plugin interface).

out of curiosity: what are you making??

greetings

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deepzero

well, i a mguessing this is the culprit: BP_TEMP.


INT3 Breakpoints should be permanent by default, no hooking required.


Does it work if you set the BP manually?


 


Are you sure writing a script wouldnt be easier here?


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mArTi

@Mr. eXoDia: Well, hooking ollydbg is not my goal :rudolph:

@deepzero: I'd prefer to write a plugin  :smilie3: BP_TEMP is the best way to use bp from a plugin, and it was written that it would be keeped if BA_PERMANENT flag was kept. However I did as exodia told.

 

I emailed Oleh, as exodia said and here's the answer if anyone's interested :

thank you for the bug report. Currently temporary breakpoints must be enabled in Options|Debugging options|Set permanent breakpoints on system calls, otherwise flag BA_PERMANENT is ignored, even for plugins. This issue will be corrected in the next OllyDbg release.

Edited by mArTi (see edit history)

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mrexodia

great news!

now what are you working on?? im really curious :D

Greetings

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