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SubjectRe: Kernel OOPS on boot
"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.

--

Brian Gerst
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