From owner-freebsd-hackers Fri Nov 7 12:25:57 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id MAA21026 for hackers-outgoing; Fri, 7 Nov 1997 12:25:57 -0800 (PST) (envelope-from owner-freebsd-hackers) Received: from pds-gateway.pdspc.com ([207.170.17.234]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id MAA21021 for ; Fri, 7 Nov 1997 12:25:53 -0800 (PST) (envelope-from khanson@pdspc.com) Received: by pds-gateway.pdspc.com with Internet Mail Service (5.0.1457.3) id ; Fri, 7 Nov 1997 14:26:03 -0600 Message-ID: <91DD7FDA88E4D011BED00000C0DD87E7124C6E@pds-gateway.pdspc.com> From: Kenny Hanson To: "FreeBSD Hackers (E-mail)" Subject: FW: Newest Pentium bug (fatal) Date: Fri, 7 Nov 1997 14:26:02 -0600 X-Priority: 3 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.0.1457.3) Content-Type: text/plain Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > -----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 > > 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 > > > share and enjoy.. > > julian