OSDev.org

Posted: **Tue Feb 01, 2005 9:37 am**

Is it possible to have a user pagetable in a superuser pagedirectory and the other way around?

Posted: **Tue Feb 01, 2005 10:19 am**

you can have a USER=1 PTE in a USER=0 PDE, if that's what you mean. However, the access control that applies is

if (CPL=3)
 if(!PTE.USER || !PDE.USER) throw new PageFault;

so as soon as one of the P*E entries has USER=0, you cannot access the page from userland.

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