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Index > Windows > guard pages, ring0, raised irql

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b1528932



Joined: 21 May 2010
Posts: 287
b1528932
I have a simple question for wich i cant find an answer.
After raising irql to DISPATCH_LEVEL i can still use the stack, right?
What if i hit guard page? Will windows bugcheck because of this? Its just a page fault, but will windows detect its on guard page, and spare me the bsod?
Post 11 Feb 2011, 07:50
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17260
Location: In your JS exploiting you and your system
revolution
Not many people here will likely have a definitive answer to this sort of question so rather you wait in vain for an informed and accurate answer that may never come I would suggest that you test it for yourself. Should be easy to set up a test, just keep pushing to the stack until something breaks.

Why are people so reluctant to test stuff these days? Is it a sign of the Internet society where people expect all the answers to be readily available? Or is it just that people are scared of breaking something? Anyhow whatever the reason is, you should still test it, even if someone gives an answer, because that answer may be wrong.
Post 11 Feb 2011, 08:15
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b1528932



Joined: 21 May 2010
Posts: 287
b1528932
why i wont test?
This question came up to me by random, doint something much diffrent and i belive its simple and documented somewere that google cant find it.

I dont exactly remember how to write seh, so i would have to go deeper into it wich i dont want. I am looking right now for an answer. If i wont find, i will test myself in few days.


This is a simple question, people who write drivers every day must know that.


my deduction right now:
It would crash. Unless OS use task gate for page fault. when usermode program gets to guard page - stack switch to ss0 since idt contain ring0 cs.
kernel mode - no stack switch unless it use TSS. And it doesnt, so thats it.
guard page -> exception -> push trap frame -> another exception?
Post 11 Feb 2011, 09:04
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