flat assembler
Message board for the users of flat assembler.

Index > Main > repnz scasb - strange error?..

Author
Thread Post new topic Reply to topic
yoshimitsu



Joined: 07 Jul 2011
Posts: 96
yoshimitsu
I guess I'm experiencing some strange error if I'm not mistaken..

I'm using "repnz scasb", edi is equal to "0042CB16" which points to "8B" and al is equal to "8B", though ZF doesn't get set.. (target is run in ollydbg)
I seriously don't know what's wrong with this..
Post 10 Sep 2011, 15:56
View user's profile Send private message Reply with quote
idle



Joined: 06 Jan 2011
Posts: 360
Location: Ukraine
idle
ecx = 0 ?
Post 10 Sep 2011, 16:21
View user's profile Send private message Reply with quote
yoshimitsu



Joined: 07 Jul 2011
Posts: 96
yoshimitsu
Nope :/
the point of the code is to search a string in memory, but instead of stopping at the correct byte, it just keeps on looping.
the strange thing is that 3 bytes further there is again "8B" and it stops at that one..
Post 10 Sep 2011, 18:48
View user's profile Send private message Reply with quote
ouadji



Joined: 24 Dec 2008
Posts: 1081
Location: Belgium
ouadji

upload all your code

_________________
I am not young enough to know everything (Oscar Wilde)- Image
Post 10 Sep 2011, 20:18
View user's profile Send private message Send e-mail Reply with quote
yoshimitsu



Joined: 07 Jul 2011
Posts: 96
yoshimitsu
ah.. I guess I got it now and yes, apparently it was just a stupid mistake of mine..
It seems like it simply got fuxed up by a breakpoint (CCh) which wasn't shown in OllyDbg but was inserted by it.
Dunno why I didn't think of something like this.. guess because I've never really experienced anything similiar
btw. normally I use OllyAdvanced and I've read somewhere that it uses a different system of inserting breakpoints, I wonder if the problem wouldn't have occurred if I have had it activated..
thanks anyways
Post 10 Sep 2011, 22:56
View user's profile Send private message Reply with quote
Display posts from previous:
Post new topic Reply to topic

Jump to:  


< Last Thread | Next Thread >
Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Copyright © 1999-2020, Tomasz Grysztar. Also on GitHub, YouTube, Twitter.

Website powered by rwasa.