How to Use BO Demos. ©2002, Jedidiah R. Crandall, Susan L. Gerhart, Jan G. Hogle.  http://sfsecurity.pr.erau.edu
10 - stack
The stack stores return pointers, temporary variables and buffers, and sometimes other things.
When something stored on the stack is no longer needed it is destroyed.  You can watch the stack be built and destroyed as you execute the program.
Notice that a ‘$’ is a return pointer to the subroutine with the same color as the box the ‘$’ is in.
A ‘?’ is a canary which only StackGuard uses.