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SubjectRe: Kernel OOPS on boot
On Thu, 26 Oct 2000, Brian Gerst wrote:

> "Richard B. Johnson" wrote:
> > Stand-alone, it can't do anything useful. However, if it generates
> > a page-fault due to the read or write, the page-fault handler could
> > do "something". Currently, the fault it fatal, probably because
> > the passed pointer is invalid.
>
> The write-protect test code is a red herring. This was caused by GCC
> 2.7.x trashing kernel_module, causing the page fault handler to fail
> when trying to find an exception handler. This code is intentionally
> trying to generate a page fault, to test if the processor allows writes
> to a write-protected page while in ring 0. Some 386's and 486's won't
> generate a page fault in this case, and we need to work around this or
> else security problems arise.

Yes.

Cheers,
Dick Johnson

Penguin : Linux version 2.2.17 on an i686 machine (801.18 BogoMips).

"Memory is like gasoline. You use it up when you are running. Of
course you get it all back when you reboot..."; Actual explanation
obtained from the Micro$oft help desk.


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