pid_t fork();
This syscall creates a new process based on the parent process. The created process will only have 1 thread copying the caller one, and will be placed on the 1st thread cluster.
This syscall returns 0 on success for the child, and the new child PID
to the parent, in failure, the parent gets -1 with the following errno:
EAGAIN: The system could not create the entity right now, try again
later.
EACCES: MAC disallowed this.