From owner-freebsd-hackers Fri Nov 14 20:29:47 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id UAA28766 for hackers-outgoing; Fri, 14 Nov 1997 20:29:47 -0800 (PST) (envelope-from owner-freebsd-hackers) Received: from vinyl.quickweb.com (vinyl.quickweb.com [209.112.4.14]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id UAA28761 for ; Fri, 14 Nov 1997 20:29:44 -0800 (PST) (envelope-from mark@quickweb.com) Received: (from mark@localhost) by vinyl.quickweb.com (8.8.7/8.6.12) id XAA08303; Fri, 14 Nov 1997 23:30:45 -0500 (EST) Message-ID: <19971114233044.08889@vmunix.com> Date: Fri, 14 Nov 1997 23:30:44 -0500 From: Mark Mayo To: Jonathan Lemon Cc: hackers@FreeBSD.ORG Subject: Re: FreeBSD Pentium Bug fix (proposed) References: <19971114171214.44521@right.PCS> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.85e In-Reply-To: <19971114171214.44521@right.PCS>; from Jonathan Lemon on Fri, Nov 14, 1997 at 05:12:15PM -0600 X-Operating-System: FreeBSD 2.2.5-STABLE i386 Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Fri, Nov 14, 1997 at 05:12:15PM -0600, Jonathan Lemon wrote: > [SNIP] > My ``fix'' is to have the IDT descriptor reference a segemnt which has > a length of 0. This has the effect of mapping SIGILL into SIGBUS, so that > the `cmpxchg8' crash now generates a Bus error. (I didn't bother returning > the correct signal; it can probably be added if it is important) Cool idea! FWIW, I applied the changes on the 4 remaining Pentium systems I have (everything else has gotten a K6 upgrade, or has been moved to PPro): 90MHz Classic, 150MHz Classic, 166MHz MMX, 233MHz MMX. In short, it worked. No measurable performance loss as far as I can tell. Hip Hip hooray! I'd buy you a beer if you were within a 100km radius of me! :-) -Mark -- ------------------------------------------------------------------------ Mark Mayo mark@vmunix.com RingZero Comp. http://www.vmunix.com/mark finger mark@vmunix.com for my PGP key and GCS code ------------------------------------------------------------------------ Win95/NT - 32 bit extensions and a graphical shell for a 16 bit patch to an an 8 bit operating system originally coded for a 4 bit microprocessor, written by a 2 bit company that can't stand 1 bit of competition. -UGU