Source : Free On-Line Dictionary of Computing

unwind the stack
     
        During the execution of a {procedural} language, one is said
        to "unwind the stack" from a called {procedure} up to a caller
        when one discards the {stack frame} and any number of frames
        above it, {pop}ping back up to the level of the given caller.
        In {C} this is done with "{longjmp}"/"{setjmp}", in {Lisp}
        with "{throw}/{catch}".  See also {smash the stack}.
     
        [{Jargon File}]