title: GDB: lx-symbols undefined command
body: <p>I am following the guide below:
  <a href="https://docs.kernel.org/dev-tools/gdb-kernel-debugging.html" rel="nofollow noreferrer">Debugging kernel and modules via gdb</a></p>
  <p>When I try to load the module symbols using the command below:
  (gdb) lx-symbols</p>
  <p>gdb says that the command is undefined.  How do I add these helper command to gdb?</p>
  <p>gdb info: gdb-7.6.1-51.el7.x86-64 on Centos 7.0</p>