> Linus discovered that the F00F bug actually attempted to write to
> the IDT. This made the trap easier. The IDT was simply marked present,
> but read-only. The resulting code became trivial because nobody but
> the kernel ever writes to the IDT (it doesn't exist in user space).
Wee historical note. Linus "discovered" this via a call from Intel
engineering. The earliest fix was based on a reverse engineered code which
also originated with Intel... considerable improved/debugged of course.
john alvord