title: Some confusing problems in reversing with IDA about gs segment
body: <p>Once I used IDA Pro to disassemble an ELF and I found some code like</p>
  
  <p><code>*mk_fp(\__gs__,12)</code> or <code>*mk_fp(\__gs__,8)</code> and so on.</p>
  
  <p>What does this mean? Does it mean something about system calls or function calls?</p>
  
  <p>Thanks a lot for some help</p>