Speculative execution, variant 4: speculative store bypass
Possibly completely unrelated question (this stuff is firmly over my head): toward the end of the first PoC there's<p><pre><code>      /* if we don't break the loop after some time when it doesn't
  work, in NO_INTERRUPTS mode with SMP disabled, the machine will lock
  up */
</code></pre>
The bit at the top of the that says<p><pre><code>  ======== Demo code (no privilege boundaries crossed) ========
</code></pre>
is suggestive and unambiguous, but the program executions show (with "$"s) that this is being executed as non-root.<p>So... is this deadlock fundamentally related to the speculative execution glitch(es)?