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From: Kenny Hanson <khanson@pdspc.com>
To: "FreeBSD Hackers (E-mail)" <freebsd-hackers@FreeBSD.ORG>
Subject: FW: Newest Pentium bug (fatal)
Date: Fri, 7 Nov 1997 14:26:02 -0600
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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