Re: Signal 11

Peter Samuelson
2000-12-08T18:13:20Z

[Dick Johnson]
> > > char main[]={0xf0,0x0f,0xc0,0xc8}; /* try also on NT (: */
> > me2v@reliant DRFDecoder $ ./op
> > Illegal instruction (core dumped)
>
> Yep. And on early Pentinums, the ones with the "f00f" bug, it would
> lock the machine tighter than a witches crotch. Ooops, not
> politically correct.... It would allow user-mode code to halt the
> machine.

...Until Linux 2.0.34 or so (can't remember the exact version number)
which had the workaround for this bug, about a week after the bug was
discovered.

And I was reminded in private mail that the correct lockup sequence is
actually

char main[]={0xf0,0x0f,0xc7,0xc8};

where the 0xc8 can be anything from 0xc8 to 0xcf.

Peter