Re: WARNING: Serious Pentium Bug

[ichudov@algebra.com (Igor Chudov @ home)]

Anonymous wrote:
> >Anonymous <anon@anon.efga.org> wrote:
> >>There is a SERIOUS bug in all pentium CPUs. The following
> >>code will crash any machine running on a pentium CPU, MMX or no
> >>MMX, any speed, regardless of OS (crash as in instant seize, hard
> >>reboot the only cure):
> >>
> >>char x [5] = { 0xf0, 0x0f, 0xc7, 0xc8 };
> >>
> >>main ()
> >>{
> >>       void (*f)() = x;
> >>       f();
> >>}
> >>
> >>This require no special permissions to run, it works fine with
> >>average-joe-userspace permissions. I have verified this, it works.
> >>Demand a new CPU from Intel.
> >
> >This didn't crash my Pentium.  Hoax?
> 
> Absolutely not. It crashed mine and is a major bug. It doesn't seem to

Crashed mine, too. The following piece of code does the same thing
but compiles cleaner:

char x [5] = { 0xf0, 0x0f, 0xc7, 0xc8 };

main ()
{
       void (*f)() = (void (*)())x;
       f();
}

> affect the PPro, though, and not the P2 due to its relation to the PPro. It
> might be fixed in later Pentiums, which begs the question of why Intel
> didn't issue a recall back then. Supposidly they were informed about it
> months ago.
> 
> Read comp.sys.intel.
> 



	- Igor.