title: kprobes not working in Ubuntu
body: <p>I am trying to run one of the standard example scripts from Systemtap. 
  The procmod_watcher.stp uses kprobes to watch fork, exec, etc.
  But when I try to Run this script I get an error. </p>
  
  <pre><code>semantic error: while resolving probe point: identifier 'kprobe' at /usr/share/systemtap/tapset/linux/nd_syscalls.stp:967:27
      source: probe nd_syscall.execve = kprobe.function("do_execve")
  </code></pre>
  
  <p>sure enough :<code>stap -L 'kprobe.function("do_execve")'</code> returns nothing.
  How can this be?</p>
  
  <p>I am using Ubuntu have followed the instructions in:
  <a href="https://sourceware.org/systemtap/wiki/SystemtapOnUbuntu" rel="nofollow">Systemtap on Ubuntu @sourceware</a> </p>
  
  <p>I have also tried compiling my own kernel and making sure Kprobes, debug_info and all the other required items are enabled though config.
  I get the same error.</p>
  
  <p>I have tried the same script on fedora and it runs practically out of the box. But I only have a virtual machine with fedora on and would like to continue with ubuntu for a while.</p>
  
  <p>What do I need to do to enable kprobes in systemtap on ubuntu?</p>