title: GDB attatching to PID - Cannot Access Memory Address
body: <p>I'm attempting to inspect a process that has "hung" on my server. I am using gdb to attatch to the process like so:</p>
  
  <pre><code>gdb -p PID
  </code></pre>
  
  <p>Whilst inside gdb I run <code>bt</code> and get the following:</p>
  
  <pre><code>(gdb) bt
  #0  0x00007f57f4be73ba in __getpwuid_r (uid=4113672712, resbuf=0x7f57f531ce40, buffer=0x1 &lt;error: Cannot access memory at address 0x1&gt;, buflen=0, 
      result=0x7f57f531a048) at ../nss/getXXbyYY_r.c:198
  #1  0x00007f5700000004 in ?? ()
  #2  0x0000000000000060 in ?? ()
  #3  0x0000000000000001 in ?? ()
  #4  0x00007f5700000031 in ?? ()
  #5  0x0000000000000000 in ?? ()
  </code></pre>
  
  <p>Is the <code>Cannot Access Memory Address</code> a potential reason for causing this process to hang? Or does it mean the software has quit but still has a running process?</p>
  
  <p>This is a CasperJS script btw.</p>