IDT

[rijnahts]

Hi,
This is regarding IDT on windows. I have modified unsused Interrupt descriptor (indexe 0x1e). And i am trying to execute the modified interrupt from user level program...
INT 1Eh
This is causing Access voilation error. When i tried with
INT 2Eh

the user program running successfully. What i understand is only some descriptors will allow to execute from user level (ring 3). And i tried modifying the 1Eh index previleges similar to 2Eh index. But still i am facing same access violation issue.

Please help me if any of you have idea onthis.


Thanks

[evaluator]

show, what bytes you wrote in INT 1E descriptor;
what OS..
also read iNT_ELS manuals, there are some ..

[rijnahts]

I am trying to set my own function address in the hi(2 bytes) and low(2 bytes) part of the 64 bit address.... remaing fileds i have set it using the following 0x2E (software interrupt) descriptor

51 c6 08 00 00 ee 53 80

I am using Windows XP as operating system

what is iNT_ELS manuals? Can you point me the link... I have tried in google but not getting related information.

Thanks

[deroko]

Seems ok, P = 1, DPL = 3...

[evaluator]

but do you know, what means "Newbies forum"!?

[esther]

he/she meant intel manuals...

[rijnahts]

esther.... what ?

[deroko]

intel manuals - http://www.intel.com/products/processor/manuals/ Quite strange, you are playing with IDT and you don't have these manuals

[JMI]

evaluator has a great sense of humor and wrote "iNT_ELS manuals" for "Intel's Manuals!" (iNT_ELS = INTEL's)

Which means you should consult "Intel's Manuals" to find the information you are looking for!

This comment about the "Newbie Forum" was probably a suggestion that if "you don't know anything about IDT on Windows," perhaps your Post belongs in the "Newbie Forum," rather in the "Advanced Reversing and Programing Forum".

At least, that is my understanding of the comments, having had alot of experience with evaluator's posting style.

Regards,

[rijnahts]

Thanks for all your responses