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Re: WARNING: Linux Intel Pentium Bug


From: seifried () LEXIE V-WAVE COM (Kurt Seifried)
Date: Fri, 7 Nov 1997 11:55:07 -0700


This Program was distributed in the newsgroups and on irc so i thought i
would post it here....
 (prog attached)

In article <3462ADCD.135B () noname com>,  <noname () noname com> wrote:
      Check this out.  If you execute F0 0F C7 C8 on a P5 it will lock the
machine up.  This is true for any operating system including usermode
Linux.  It's pretty cool.  Basically, the opcodes are an invalid form of
cmpxchg8b eax with a lock prefix.  Has anyone seen this before?  The
problem doesn't show itself for the Pentium Pro or Pentium 2.

Cool.  It also works (sic) from V86 mode, so if you want to play around, just
use DOS debug under whatever DOS emulator the OS you are using provides.
Anyone try it on a Pentium MMX?

--Tim Smith

Ran it on my P166, kaboom, ran it on my new P166MMX, kaboom. I guess that
would be a yes. This is kind of scary, is there any possibility of a
kernel patch that can take care of this?

-seifried



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