Exit

Problem

This problem comes from pwn.college - Building a Web Server ⤴.

Your first task is to create the simplest possible program - one that immediately terminates when run. In this challenge, you will use the exit ⤴ syscall, which is responsible for ending a process and returning an exit status to the operating system. This syscall takes a single argument: the exit status (with 0 typically indicating success). Understanding how to cleanly exit a program is crucial because it ensures your process communicates its completion state properly.

Solution

Run /challenge/run and the code below will be printed to the console. I saved the output to server.s, compiled it and then ran /challenge/run server to finish. Then compile it and run /challenge/run server to finish the challenge.

# server.s

.intel_syntax noprefix
.global _start

.section .text

_start:
  # Exit
  mov rdi, 0
  mov rax, 60        # exit syscall number: 60
  syscall

.section .data