Re: Pentium bug fix

Adam D. Bradley (
Thu, 18 Dec 1997 13:48:52 -0500 (EST)

> > 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.

In case anyone is curious, I kept just about the entire f00f thread
from linux-kernel, beginning to end, in a Pine folder. It's about
420Kb uncompressed, I've posted a gzipped copy (100Kb or so):


Things look so bad everywhere      Adam D. Bradley
In this whole world what is fair        Boston University Computer Science
We walk blind and we try to see             Ph.D. student and Linux hacker
Falling behind in what could be  ---->  Bring me a Higher Love  ---->  <><