Read of memory location 0x7ffe0000 in windows NT

[Laurent Pinchart]

> > After some investigation, it seems that reading the memory location
> > 0x7ffe0000 should return KeTickCount.LowPart to the user process. Has
> > anyone ever heard about that ? I was wondering if it was a native windows
> > NT behaviour, or if it was done by a special kernel-space exception
> > handler installed by the program.
>
> It's a native NT thing; a page of memory at that address is shared
> between user and kernel space. The definition in the w2k ddk.

I downloaded the w2k ddk, and SharedUserData seems to be located at 
0xffdf0000 (line 5099 of ntddk.h). Did Microsoft move the page around between 
NT4 and NT5, or is there something I don't understand ?

Laurent Pinchart