title: Meaning of a gdb backtrace when there is not source code
body: <p>I have a <code>gdb</code> backtrace of a crashed process, but I can't see the specific line in which the crash occurred because the source code was not in that moment. <strong>I don't understand some of the information given by the mentioned backtrace.</strong></p>
  
  <p>The backtrace is made of lines like the following one:</p>
  
  <pre><code>&lt;path_to_binary_file&gt;(_Z12someFunction+0x18)[0x804a378]
  </code></pre>
  
  <p>Notice that <code>_Z12someFunction</code> is the mangled name of <code>int someFunction(double )</code>.</p>
  
  <p><strong>My questions are:</strong></p>
  
  <p>Does the <code>+0x18</code> indicate the offset, starting at <code>_Z12someFunction</code> address, of the assembly instruction that produced the crash? </p>
  
  <p>If the previous question is affirmative, and taking into account that I am working with a 32-bit architecture, does the <code>+0x18</code> indicates 0x18 * 4 bytes? </p>
  
  <p>If the above is affirmative, I assume that the address <code>0x804a378</code> is the <code>_Z12someFunction</code> plus <code>0x18</code>, am I right?</p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>The error has ocurred in a <strong>production machine</strong> (no cores enabled), and it seems to be a timing-dependant bug, so it is not easy to reproduce it. That is because the information I am asking for is important to me in this occasion.</p>