code: def allocate_stack(size=DEFAULT_STACK_SIZE):
      
      # Allocate memory with appropriate flags for a stack as in https://blog.fefe.de/?ts=a85c8ba7
      base = libc.mmap(
          None,
          size + GUARD_PAGE_SIZE,
          libc.PROT_READ | libc.PROT_WRITE,
          libc.MAP_PRIVATE | libc.MAP_ANONYMOUS | libc.MAP_GROWSDOWN | libc.MAP_STACK,
          -1, 0)
  
      try:
          # create a guard page that crashes the application when it is written to (on stack overflow)
          libc.mprotect(base, GUARD_PAGE_SIZE, libc.PROT_NONE)
  
          yield ctypes.c_void_p(base + size + GUARD_PAGE_SIZE)
      finally:
          libc.munmap(base, size + GUARD_PAGE_SIZE)
docs: Allocate some memory that can be used as a stack.
      @return: a ctypes void pointer to the *top* of the stack.