title: Replacing shorter with longers instructions in-place (assembly)
body: <p>When replacing a longer instruction with a shorter one, we can just pad with <code>nop</code>s.</p>
  
  <p>How would I do an inline replace of an the other way around?</p>
  
  <p>And by <b>inline</b> I mean not a <code>jmp</code> to some other free memory and then getting back.</p>
  
  <p>Said with other words, is it possible to somehow <b>insert</b> more ops? How is that done? Should the header of the binary be modified somehow? What happens with all the <code>jmp</code> ops (will they keep working after that theoretical change?). What about if there are absolute <code>jmp</code>s? Those should be modified as well, right? What else should be done (if this is actually possible)?</p>