title: mmap on /proc/pid/mem
body: <p>Has anybody succeeded in mmap'ing a /proc/pid/mem file with Linux kernel 2.6?  I am getting an ENODEV (No such device) error.  My call looks like this:</p>
  
  <pre><code>char * map = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, mem_fd, offset);
  </code></pre>
  
  <p>And I have verified by looking at the /proc/pid/maps file while debugging that, when execution reaches this call, offset has the value of the top of the stack minus PAGE_SIZE.  I have also verified with ptrace that mmap is setting errno to ENODEV.</p>