My guess is that you can fix both the "need to exit()" and all the other issues that you haven't run into but exist, by making your entry point _start instead o

My guess is that you can fix both the "need to exit()" and all the other issues that you haven't run into but exist, by making your entry point _start instead of main (which is NOT the first thing that runs in your program; _start is!). If you `readelf -h` an executable on your system and then look up the entry point it gives you in the executable's symbols you'll see it's indeed _start.