return_one
extern char return_one[];
int return_one(void); /* begin marker -- shellcode entry */
memcpy(map, (void *)return_one,
(uintptr_t)return_one_end - (uintptr_t)return_one);
memcpy(map, (void *)return_one,
(uintptr_t)return_one_end - (uintptr_t)return_one);