Hi
On Thu, 16 Mar 2000, you 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();
> }
>
In a proper Protected mode OS
THis can cause different programs which use a similar code snippet some
where in their code to behave differently depending on the Memory map for
processes on that OS. But it should never cause any serious problem to any
other processes or components. If it does then its not virtualizing the
enviornment properly for the processes.
In a Real mode OS
If f is a FAR POINTER then as 0x0ff0:0xc8c7 may be pointing to some Dos or
some other Bois service,(Verify using DEBUG in DOS) then its behaviour depends
on what its pointing to. However In a Real mode OS the system could be held to
ransom using this code :-)
---------
Keep :-)
HanishKVC
http://HanishKVC.tripod.com/
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