Function exit1

freebsd/kern/kern_exit.c:203–690

* Exit: deallocate address space and other resources, change proc state to * zombie, and unlink proc from allproc and parent's lists. Save exit status * and rusage for wait(). Check for child processes and orphan them. */

 * and rusage for wait().  Check for child processes and orphan them.
 */
void
exit1(struct thread *td, int rval, int signo)
{
	struct proc *p, *nq, *q, *t;
	struct thread *tdt;
	ksiginfo_t *ksi, *ksi1;
	int signal_parent;

	mtx_assert(&Giant, MA_NOTOWNED);
	KASSERT(rval == 0 || signo == 0, ("exit1 rv %d sig %d", rval, signo));

	p = td->td_proc;
	/*
	 * XXX in case we're rebooting we just let init die in order to
	 * work around an unsolved stack overflow seen very late during
	 * shutdown on sparc64 when the gmirror worker process exists.
	 * XXX what to do now that sparc64 is gone... remove if?
	 */
	if (p == initproc && rebooting == 0) {
		printf("init died (signal %d, exit %d)\n", signo, rval);
		panic("Going nowhere without my init!");
	}

	/*
	 * Deref SU mp, since the thread does not return to userspace.
	 */
	td_softdep_cleanup(td);

	/*
	 * MUST abort all other threads before proceeding past here.
	 */
	PROC_LOCK(p);
	/*
	 * First check if some other thread or external request got
	 * here before us.  If so, act appropriately: exit or suspend.
	 * We must ensure that stop requests are handled before we set
	 * P_WEXIT.
	 */
	thread_suspend_check(0);
	while (p->p_flag & P_HADTHREADS) {
		/*
		 * Kill off the other threads. This requires
		 * some co-operation from other parts of the kernel
		 * so it may not be instantaneous.  With this state set
		 * any thread entering the kernel from userspace will
		 * thread_exit() in trap().  Any thread attempting to
		 * sleep will return immediately with EINTR or EWOULDBLOCK
		 * which will hopefully force them to back out to userland
		 * freeing resources as they go.  Any thread attempting
		 * to return to userland will thread_exit() from userret().
		 * thread_exit() will unsuspend us when the last of the
		 * other threads exits.
		 * If there is already a thread singler after resumption,
		 * calling thread_single will fail; in that case, we just
		 * re-check all suspension request, the thread should
		 * either be suspended there or exit.
		 */
		if (!thread_single(p, SINGLE_EXIT))