title: _THIS_IP_ macro in linux kernel
body: <p>The following macro appears in include/linux/kernel.h</p>
  
  <pre><code>#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&amp;&amp;__here; })
  </code></pre>
  
  <p>I don't understand what the second &amp; applied to __here would do. The first takes the address of the local label, but what about the second? </p>