Date: Fri, 7 Nov 1997 14:26:02 -0600 From: Kenny Hanson <khanson@pdspc.com> To: "FreeBSD Hackers (E-mail)" <freebsd-hackers@FreeBSD.ORG> Subject: FW: Newest Pentium bug (fatal) Message-ID: <91DD7FDA88E4D011BED00000C0DD87E7124C6E@pds-gateway.pdspc.com>
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> -----Original Message-----
> From: Kenny Hanson
> Sent: Friday, November 07, 1997 2:24 PM
> To: 'Julian Elischer'
> Subject: RE: Newest Pentium bug (fatal)
>
> Yessir.... this one screeched to a halt... hehehe
>
> CPU: Pentium (89.81-MHz 586-class CPU)
> Origin = "GenuineIntel" Id = 0x524 Stepping=4
> Features=0x1bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8>
>
> Trying a 233MMX as soon as I got the compiler installed...
>
> Kenny
>
> -----Original Message-----
> From: Julian Elischer [SMTP:julian@whistle.com]
> Sent: Friday, November 07, 1997 12:39 PM
> To: hackers@FreeBSD.ORG
> Subject: Newest Pentium bug (fatal)
>
> 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[] = { 0xf0, 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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