Date: Fri, 7 Nov 1997 22:03:48 +0100 (MET) From: Finn Arne Gangstad <finnag@guardian.no> To: hackers@FreeBSD.ORG Subject: Re: Newest Pentium bug (fatal) Message-ID: <Pine.LNX.3.95.971107214918.23770A-100000@lucifer.guardian.no> In-Reply-To: <3463605C.41C67EA6@whistle.com>
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On Fri, 7 Nov 1997, Julian Elischer wrote:
> 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();
> }
EEk - don't try this on a compaq armada 1510 - no hard reset button (that
i can find) and power button is also soft power - so now I have to wait
for the battery to go empty on me..
objdump --disassemble-all --show-raw-insn pentiumcrash.o
Disassembly of section .data:
00000000 <x> f0 0f c7 c8 lock cmpxchg8b %eax
Bleh - illegal address mode but why oh why does it have to hang :(
- Finn Arne
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