/* file: experiment1.c
   -------------------
   author:  Ted Baker
   version: $Version$
   last modified by: $Author: cop4610 $ on: $Date: 2002/08/21 19:27:43 $
   purpose: demonstrate linux/x86 stack modification 
*/ 

#include <unistd.h> 
#include <stdio.h> 

void alt () {
  fprintf (stderr, "in alt...\n");
}

void sub () {
  char buf[10];
  /* overwrite return address with entrypoint of alt */
  *((int *)((char *)buf + 28)) = (int) alt;
}

int main (int argc, char *const argv[]) { 
  sub ();
  fprintf (stderr, "done.\n");
  return 0;
}