Re: Handle kernel page faults using task gate

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> * eliad lubovsky <eliadl@013.net> wrote:
> 
> > I am trying to handle page faults exceptions in the kernel using the 
> > task gate mechanism. I succeeded to transfer the execution to my page 
> > fault handler using a new TSS and updates to the GDT and IDT tables 
> > (similar to the double fault mechanism in 2.6). After handling the 
> > fault and allocating the physical page I use the iret instruction to 
> > switch back to the previous task. The problem is that I got a double 
> > fault with the same address that cause the fault (although the 
> > physical page is allocated and mapped). Any clues?
> 
> are you clearing the 'nested task' (NT) flag of the new TSS once you 
> have switched to it?

correction - i meant the 'busy' bit in the TSS descriptor. It's being 
set by TSS-switch operations, and needs to be cleared.

	Ingo