usr/src/sys/kern/kern_exit.c

/*
 * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *	@(#)kern_exit.c	7.52 (Berkeley) %G%
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/map.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/kernel.h>
#include <sys/buf.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <sys/vnode.h>
#include <sys/syslog.h>
#include <sys/malloc.h>
#include <sys/resourcevar.h>
#include <sys/ptrace.h>

#include <machine/cpu.h>
#ifdef COMPAT_43
#include <machine/reg.h>
#include <machine/psl.h>
#endif

#include <vm/vm.h>
#include <vm/vm_kern.h>

/*
 * Exit system call: pass back caller's arg
 */
struct rexit_args {
	int	rval;
};
/* ARGSUSED */
rexit(p, uap, retval)
	struct proc *p;
	struct rexit_args *uap;
	int *retval;
{

	exit1(p, W_EXITCODE(uap->rval, 0));
	/* NOTREACHED */
}

/*
 * 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.
 */
exit1(p, rv)
	register struct proc *p;
	int rv;
{
	register struct proc *q, *nq;
	register struct proc **pp;
	register struct vmspace *vm;
	int s;

	if (p->p_pid == 1)
		panic("init died (signal %d, exit %d)",
		    WTERMSIG(rv), WEXITSTATUS(rv));
#ifdef PGINPROF
	vmsizmon();
#endif
	if (p->p_flag & SPROFIL)
		stopprofclock(p);
	MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
		M_ZOMBIE, M_WAITOK);
	/*
	 * If parent is waiting for us to exit or exec,
	 * SPPWAIT is set; we will wakeup the parent below.
	 */
	p->p_flag &= ~(STRC|SPPWAIT);
	p->p_flag |= SWEXIT;
	p->p_sigignore = ~0;
	p->p_sig = 0;
	untimeout(realitexpire, (caddr_t)p);

	/*
	 * Close open files and release open-file table.
	 * This may block!
	 */
	fdfree(p);

	/* The next two chunks should probably be moved to vmspace_exit. */
	vm = p->p_vmspace;
#ifdef SYSVSHM
	if (vm->vm_shm)
		shmexit(p);
#endif
	/*
	 * Release user portion of address space.
	 * This releases references to vnodes,
	 * which could cause I/O if the file has been unlinked.
	 * Need to do this early enough that we can still sleep.
	 * Can't free the entire vmspace as the kernel stack
	 * may be mapped within that space also.
	 */
	if (vm->vm_refcnt == 1)
		(void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
		    VM_MAXUSER_ADDRESS);

	if (SESS_LEADER(p)) {
		register struct session *sp = p->p_session;

		if (sp->s_ttyvp) {
			/*
			 * Controlling process.
			 * Signal foreground pgrp,
			 * drain controlling terminal
			 * and revoke access to controlling terminal.
			 */
			if (sp->s_ttyp->t_session == sp) {
				if (sp->s_ttyp->t_pgrp)
					pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
				(void) ttywait(sp->s_ttyp);
				vgoneall(sp->s_ttyvp);
			}
			vrele(sp->s_ttyvp);
			sp->s_ttyvp = NULL;
			/*
			 * s_ttyp is not zero'd; we use this to indicate
			 * that the session once had a controlling terminal.
			 * (for logging and informational purposes)
			 */
		}
		sp->s_leader = NULL;
	}
	fixjobc(p, p->p_pgrp, 0);
	p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
	(void) acct(p);
#ifdef KTRACE
	/*
	 * release trace file
	 */
	p->p_traceflag = 0;	/* don't trace the vrele() */
	if (p->p_tracep)
		vrele(p->p_tracep);
#endif
	/*
	 * Remove proc from allproc queue and pidhash chain.
	 * Place onto zombproc.  Unlink from parent's child list.
	 */
	if (*p->p_prev = p->p_nxt)
		p->p_nxt->p_prev = p->p_prev;
	if (p->p_nxt = zombproc)
		p->p_nxt->p_prev = &p->p_nxt;
	p->p_prev = &zombproc;
	zombproc = p;
	p->p_stat = SZOMB;

	for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash)
		if (*pp == p) {
			*pp = p->p_hash;
			goto done;
		}
	panic("exit");
done:

	if (p->p_cptr)		/* only need this if any child is S_ZOMB */
		wakeup((caddr_t) initproc);
	for (q = p->p_cptr; q != NULL; q = nq) {
		nq = q->p_osptr;
		if (nq != NULL)
			nq->p_ysptr = NULL;
		if (initproc->p_cptr)
			initproc->p_cptr->p_ysptr = q;
		q->p_osptr = initproc->p_cptr;
		q->p_ysptr = NULL;
		initproc->p_cptr = q;

		q->p_pptr = initproc;
		/*
		 * Traced processes are killed
		 * since their existence means someone is screwing up.
		 */
		if (q->p_flag&STRC) {
			q->p_flag &= ~STRC;
			psignal(q, SIGKILL);
		}
	}
	p->p_cptr = NULL;

	/*
	 * Save exit status and final rusage info, adding in child rusage
	 * info and self times.
	 */
	p->p_xstat = rv;
	*p->p_ru = p->p_stats->p_ru;
	calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
	ruadd(p->p_ru, &p->p_stats->p_cru);

	/*
	 * Notify parent that we're gone.
	 */
	psignal(p->p_pptr, SIGCHLD);
	wakeup((caddr_t)p->p_pptr);
#if defined(tahoe)
	/* move this to cpu_exit */
	p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
#endif
	/*
	 * Clear curproc after we've done all operations
	 * that could block, and before tearing down the rest
	 * of the process state that might be used from clock, etc.
	 * Also, can't clear curproc while we're still runnable,
	 * as we're not on a run queue (we are current, just not
	 * a proper proc any longer!).
	 *
	 * Other substructures are freed from wait().
	 */
	curproc = NULL;
	if (--p->p_limit->p_refcnt == 0)
		FREE(p->p_limit, M_SUBPROC);

	/*
	 * Finally, call machine-dependent code to release the remaining
	 * resources including address space, the kernel stack and pcb.
	 * The address space is released by "vmspace_free(p->p_vmspace)";
	 * This is machine-dependent, as we may have to change stacks
	 * or ensure that the current one isn't reallocated before we
	 * finish.  cpu_exit will end with a call to cpu_swtch(), finishing
	 * our execution (pun intended).
	 */
	cpu_exit(p);
	/* NOTREACHED */
}

struct wait_args {
	int	pid;
	int	*status;
	int	options;
	struct	rusage *rusage;
#ifdef COMPAT_43
	int	compat;		/* pseudo */
#endif
};

#ifdef COMPAT_43
#ifdef hp300
#include <machine/frame.h>
#define GETPS(rp)	((struct frame *)(rp))->f_sr
#else
#define GETPS(rp)	(rp)[PS]
#endif

owait(p, uap, retval)
	struct proc *p;
	register struct wait_args *uap;
	int *retval;
{

#ifdef PSL_ALLCC
	if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) {
		uap->options = 0;
		uap->rusage = NULL;
	} else {
		uap->options = p->p_md.md_regs[R0];
		uap->rusage = (struct rusage *)p->p_md.md_regs[R1];
	}
#else
	uap->options = 0;
	uap->rusage = NULL;
#endif
	uap->pid = WAIT_ANY;
	uap->status = NULL;
	uap->compat = 1;
	return (wait1(p, uap, retval));
}

wait4(p, uap, retval)
	struct proc *p;
	struct wait_args *uap;
	int *retval;
{

	uap->compat = 0;
	return (wait1(p, uap, retval));
}
#else
#define	wait1	wait4
#endif

/*
 * Wait: check child processes to see if any have exited,
 * stopped under trace, or (optionally) stopped by a signal.
 * Pass back status and deallocate exited child's proc structure.
 */
wait1(q, uap, retval)
	register struct proc *q;
	register struct wait_args *uap;
	int retval[];
{
	register int nfound;
	register struct proc *p, *t;
	int status, error;

	if (uap->pid == 0)
		uap->pid = -q->p_pgid;
#ifdef notyet
	if (uap->options &~ (WUNTRACED|WNOHANG))
		return (EINVAL);
#endif
loop:
	nfound = 0;
	for (p = q->p_cptr; p; p = p->p_osptr) {
		if (uap->pid != WAIT_ANY &&
		    p->p_pid != uap->pid && p->p_pgid != -uap->pid)
			continue;
		nfound++;
		if (p->p_stat == SZOMB) {
			retval[0] = p->p_pid;
#ifdef COMPAT_43
			if (uap->compat)
				retval[1] = p->p_xstat;
			else
#endif
			if (uap->status) {
				status = p->p_xstat;	/* convert to int */
				if (error = copyout((caddr_t)&status,
				    (caddr_t)uap->status, sizeof(status)))
					return (error);
			}
			if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
			    (caddr_t)uap->rusage, sizeof (struct rusage))))
				return (error);
			/*
			 * If we got the child via a ptrace 'attach',
			 * we need to give it back to the old parent.
			 */
			if (p->p_oppid && (t = pfind(p->p_oppid))) {
				p->p_oppid = 0;
				proc_reparent(p, t);
				psignal(t, SIGCHLD);
				wakeup((caddr_t)t);
				return (0);
			}
			p->p_xstat = 0;
			ruadd(&q->p_stats->p_cru, p->p_ru);
			FREE(p->p_ru, M_ZOMBIE);

			/*
			 * Decrement the count of procs running with this uid.
			 */
			(void)chgproccnt(p->p_cred->p_ruid, -1);

			/*
			 * Free up credentials.
			 */
			if (--p->p_cred->p_refcnt == 0) {
				crfree(p->p_cred->pc_ucred);
				FREE(p->p_cred, M_SUBPROC);
			}

			/*
			 * Finally finished with old proc entry.
			 * Unlink it from its process group and free it.
			 */
			leavepgrp(p);
			if (*p->p_prev = p->p_nxt)	/* off zombproc */
				p->p_nxt->p_prev = p->p_prev;
			if (q = p->p_ysptr)
				q->p_osptr = p->p_osptr;
			if (q = p->p_osptr)
				q->p_ysptr = p->p_ysptr;
			if ((q = p->p_pptr)->p_cptr == p)
				q->p_cptr = p->p_osptr;

			/*
			 * Give machine-dependent layer a chance
			 * to free anything that cpu_exit couldn't
			 * release while still running in process context.
			 */
			cpu_wait(p);
			FREE(p, M_PROC);
			nprocs--;
			return (0);
		}
		if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
		    (p->p_flag & STRC || uap->options & WUNTRACED)) {
			p->p_flag |= SWTED;
			retval[0] = p->p_pid;
#ifdef COMPAT_43
			if (uap->compat) {
				retval[1] = W_STOPCODE(p->p_xstat);
				error = 0;
			} else
#endif
			if (uap->status) {
				status = W_STOPCODE(p->p_xstat);
				error = copyout((caddr_t)&status,
					(caddr_t)uap->status, sizeof(status));
			} else
				error = 0;
			return (error);
		}
	}
	if (nfound == 0)
		return (ECHILD);
	if (uap->options & WNOHANG) {
		retval[0] = 0;
		return (0);
	}
	if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0))
		return (error);
	goto loop;
}

/*
 * make process 'parent' the new parent of process 'child'.
 */
void
proc_reparent(child, parent)
	register struct proc *child;
	register struct proc *parent;
{
	register struct proc *o;
	register struct proc *y;

	if (child->p_pptr == parent)
		return;

	/* fix up the child linkage for the old parent */
	o = child->p_osptr;
	y = child->p_ysptr;
	if (y)
		y->p_osptr = o;
	if (o)
		o->p_ysptr = y;
	if (child->p_pptr->p_cptr == child)
		child->p_pptr->p_cptr = o;

	/* fix up child linkage for new parent */
	o = parent->p_cptr;
	if (o)
		o->p_ysptr = child;
	child->p_osptr = o;
	child->p_ysptr = NULL;
	parent->p_cptr = child;
	child->p_pptr = parent;
}
Commit	Line	Data
	1	/*
	2	* Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* %sccs.include.redist.c%
	6	*
	7	* @(#)kern_exit.c 7.52 (Berkeley) %G%
	8	*/
	9
	10	#include <sys/param.h>
	11	#include <sys/systm.h>
	12	#include <sys/map.h>
	13	#include <sys/ioctl.h>
	14	#include <sys/proc.h>
	15	#include <sys/tty.h>
	16	#include <sys/time.h>
	17	#include <sys/resource.h>
	18	#include <sys/kernel.h>
	19	#include <sys/buf.h>
	20	#include <sys/wait.h>
	21	#include <sys/file.h>
	22	#include <sys/vnode.h>
	23	#include <sys/syslog.h>
	24	#include <sys/malloc.h>
	25	#include <sys/resourcevar.h>
	26	#include <sys/ptrace.h>
	27
	28	#include <machine/cpu.h>
	29	#ifdef COMPAT_43
	30	#include <machine/reg.h>
	31	#include <machine/psl.h>
	32	#endif
	33
	34	#include <vm/vm.h>
	35	#include <vm/vm_kern.h>
	36
	37	/*
	38	* Exit system call: pass back caller's arg
	39	*/
	40	struct rexit_args {
	41	int rval;
	42	};
	43	/* ARGSUSED */
	44	rexit(p, uap, retval)
	45	struct proc *p;
	46	struct rexit_args *uap;
	47	int *retval;
	48	{
	49
	50	exit1(p, W_EXITCODE(uap->rval, 0));
	51	/* NOTREACHED */
	52	}
	53
	54	/*
	55	* Exit: deallocate address space and other resources,
	56	* change proc state to zombie, and unlink proc from allproc
	57	* and parent's lists. Save exit status and rusage for wait().
	58	* Check for child processes and orphan them.
	59	*/
	60	exit1(p, rv)
	61	register struct proc *p;
	62	int rv;
	63	{
	64	register struct proc q, nq;
	65	register struct proc **pp;
	66	register struct vmspace *vm;
	67	int s;
	68
	69	if (p->p_pid == 1)
	70	panic("init died (signal %d, exit %d)",
	71	WTERMSIG(rv), WEXITSTATUS(rv));
	72	#ifdef PGINPROF
	73	vmsizmon();
	74	#endif
	75	if (p->p_flag & SPROFIL)
	76	stopprofclock(p);
	77	MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
	78	M_ZOMBIE, M_WAITOK);
	79	/*
	80	* If parent is waiting for us to exit or exec,
	81	* SPPWAIT is set; we will wakeup the parent below.
	82	*/
	83	p->p_flag &= ~(STRC\|SPPWAIT);
	84	p->p_flag \|= SWEXIT;
	85	p->p_sigignore = ~0;
	86	p->p_sig = 0;
	87	untimeout(realitexpire, (caddr_t)p);
	88
	89	/*
	90	* Close open files and release open-file table.
	91	* This may block!
	92	*/
	93	fdfree(p);
	94
	95	/* The next two chunks should probably be moved to vmspace_exit. */
	96	vm = p->p_vmspace;
	97	#ifdef SYSVSHM
	98	if (vm->vm_shm)
	99	shmexit(p);
	100	#endif
	101	/*
	102	* Release user portion of address space.
	103	* This releases references to vnodes,
	104	* which could cause I/O if the file has been unlinked.
	105	* Need to do this early enough that we can still sleep.
	106	* Can't free the entire vmspace as the kernel stack
	107	* may be mapped within that space also.
	108	*/
	109	if (vm->vm_refcnt == 1)
	110	(void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
	111	VM_MAXUSER_ADDRESS);
	112
	113	if (SESS_LEADER(p)) {
	114	register struct session *sp = p->p_session;
	115
	116	if (sp->s_ttyvp) {
	117	/*
	118	* Controlling process.
	119	* Signal foreground pgrp,
	120	* drain controlling terminal
	121	* and revoke access to controlling terminal.
	122	*/
	123	if (sp->s_ttyp->t_session == sp) {
	124	if (sp->s_ttyp->t_pgrp)
	125	pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
	126	(void) ttywait(sp->s_ttyp);
	127	vgoneall(sp->s_ttyvp);
	128	}
	129	vrele(sp->s_ttyvp);
	130	sp->s_ttyvp = NULL;
	131	/*
	132	* s_ttyp is not zero'd; we use this to indicate
	133	* that the session once had a controlling terminal.
	134	* (for logging and informational purposes)
	135	*/
	136	}
	137	sp->s_leader = NULL;
	138	}
	139	fixjobc(p, p->p_pgrp, 0);
	140	p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
	141	(void) acct(p);
	142	#ifdef KTRACE
	143	/*
	144	* release trace file
	145	*/
	146	p->p_traceflag = 0; /* don't trace the vrele() */
	147	if (p->p_tracep)
	148	vrele(p->p_tracep);
	149	#endif
	150	/*
	151	* Remove proc from allproc queue and pidhash chain.
	152	* Place onto zombproc. Unlink from parent's child list.
	153	*/
	154	if (*p->p_prev = p->p_nxt)
	155	p->p_nxt->p_prev = p->p_prev;
	156	if (p->p_nxt = zombproc)
	157	p->p_nxt->p_prev = &p->p_nxt;
	158	p->p_prev = &zombproc;
	159	zombproc = p;
	160	p->p_stat = SZOMB;
	161
	162	for (pp = &pidhash[PIDHASH(p->p_pid)]; pp; pp = &(pp)->p_hash)
	163	if (*pp == p) {
	164	*pp = p->p_hash;
	165	goto done;
	166	}
	167	panic("exit");
	168	done:
	169
	170	if (p->p_cptr) /* only need this if any child is S_ZOMB */
	171	wakeup((caddr_t) initproc);
	172	for (q = p->p_cptr; q != NULL; q = nq) {
	173	nq = q->p_osptr;
	174	if (nq != NULL)
	175	nq->p_ysptr = NULL;
	176	if (initproc->p_cptr)
	177	initproc->p_cptr->p_ysptr = q;
	178	q->p_osptr = initproc->p_cptr;
	179	q->p_ysptr = NULL;
	180	initproc->p_cptr = q;
	181
	182	q->p_pptr = initproc;
	183	/*
	184	* Traced processes are killed
	185	* since their existence means someone is screwing up.
	186	*/
	187	if (q->p_flag&STRC) {
	188	q->p_flag &= ~STRC;
	189	psignal(q, SIGKILL);
	190	}
	191	}
	192	p->p_cptr = NULL;
	193
	194	/*
	195	* Save exit status and final rusage info, adding in child rusage
	196	* info and self times.
	197	*/
	198	p->p_xstat = rv;
	199	*p->p_ru = p->p_stats->p_ru;
	200	calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
	201	ruadd(p->p_ru, &p->p_stats->p_cru);
	202
	203	/*
	204	* Notify parent that we're gone.
	205	*/
	206	psignal(p->p_pptr, SIGCHLD);
	207	wakeup((caddr_t)p->p_pptr);
	208	#if defined(tahoe)
	209	/* move this to cpu_exit */
	210	p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
	211	#endif
	212	/*
	213	* Clear curproc after we've done all operations
	214	* that could block, and before tearing down the rest
	215	* of the process state that might be used from clock, etc.
	216	* Also, can't clear curproc while we're still runnable,
	217	* as we're not on a run queue (we are current, just not
	218	* a proper proc any longer!).
	219	*
	220	* Other substructures are freed from wait().
	221	*/
	222	curproc = NULL;
	223	if (--p->p_limit->p_refcnt == 0)
	224	FREE(p->p_limit, M_SUBPROC);
	225
	226	/*
	227	* Finally, call machine-dependent code to release the remaining
	228	* resources including address space, the kernel stack and pcb.
	229	* The address space is released by "vmspace_free(p->p_vmspace)";
	230	* This is machine-dependent, as we may have to change stacks
	231	* or ensure that the current one isn't reallocated before we
	232	* finish. cpu_exit will end with a call to cpu_swtch(), finishing
	233	* our execution (pun intended).
	234	*/
	235	cpu_exit(p);
	236	/* NOTREACHED */
	237	}
	238
	239	struct wait_args {
	240	int pid;
	241	int *status;
	242	int options;
	243	struct rusage *rusage;
	244	#ifdef COMPAT_43
	245	int compat; /* pseudo */
	246	#endif
	247	};
	248
	249	#ifdef COMPAT_43
	250	#ifdef hp300
	251	#include <machine/frame.h>
	252	#define GETPS(rp) ((struct frame *)(rp))->f_sr
	253	#else
	254	#define GETPS(rp) (rp)[PS]
	255	#endif
	256
	257	owait(p, uap, retval)
	258	struct proc *p;
	259	register struct wait_args *uap;
	260	int *retval;
	261	{
	262
	263	#ifdef PSL_ALLCC
	264	if ((GETPS(p->p_md.md_regs) & PSL_ALLCC) != PSL_ALLCC) {
	265	uap->options = 0;
	266	uap->rusage = NULL;
	267	} else {
	268	uap->options = p->p_md.md_regs[R0];
	269	uap->rusage = (struct rusage *)p->p_md.md_regs[R1];
	270	}
	271	#else
	272	uap->options = 0;
	273	uap->rusage = NULL;
	274	#endif
	275	uap->pid = WAIT_ANY;
	276	uap->status = NULL;
	277	uap->compat = 1;
	278	return (wait1(p, uap, retval));
	279	}
	280
	281	wait4(p, uap, retval)
	282	struct proc *p;
	283	struct wait_args *uap;
	284	int *retval;
	285	{
	286
	287	uap->compat = 0;
	288	return (wait1(p, uap, retval));
	289	}
	290	#else
	291	#define wait1 wait4
	292	#endif
	293
	294	/*
	295	* Wait: check child processes to see if any have exited,
	296	* stopped under trace, or (optionally) stopped by a signal.
	297	* Pass back status and deallocate exited child's proc structure.
	298	*/
	299	wait1(q, uap, retval)
	300	register struct proc *q;
	301	register struct wait_args *uap;
	302	int retval[];
	303	{
	304	register int nfound;
	305	register struct proc p, t;
	306	int status, error;
	307
	308	if (uap->pid == 0)
	309	uap->pid = -q->p_pgid;
	310	#ifdef notyet
	311	if (uap->options &~ (WUNTRACED\|WNOHANG))
	312	return (EINVAL);
	313	#endif
	314	loop:
	315	nfound = 0;
	316	for (p = q->p_cptr; p; p = p->p_osptr) {
	317	if (uap->pid != WAIT_ANY &&
	318	p->p_pid != uap->pid && p->p_pgid != -uap->pid)
	319	continue;
	320	nfound++;
	321	if (p->p_stat == SZOMB) {
	322	retval[0] = p->p_pid;
	323	#ifdef COMPAT_43
	324	if (uap->compat)
	325	retval[1] = p->p_xstat;
	326	else
	327	#endif
	328	if (uap->status) {
	329	status = p->p_xstat; /* convert to int */
	330	if (error = copyout((caddr_t)&status,
	331	(caddr_t)uap->status, sizeof(status)))
	332	return (error);
	333	}
	334	if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
	335	(caddr_t)uap->rusage, sizeof (struct rusage))))
	336	return (error);
	337	/*
	338	* If we got the child via a ptrace 'attach',
	339	* we need to give it back to the old parent.
	340	*/
	341	if (p->p_oppid && (t = pfind(p->p_oppid))) {
	342	p->p_oppid = 0;
	343	proc_reparent(p, t);
	344	psignal(t, SIGCHLD);
	345	wakeup((caddr_t)t);
	346	return (0);
	347	}
	348	p->p_xstat = 0;
	349	ruadd(&q->p_stats->p_cru, p->p_ru);
	350	FREE(p->p_ru, M_ZOMBIE);
	351
	352	/*
	353	* Decrement the count of procs running with this uid.
	354	*/
	355	(void)chgproccnt(p->p_cred->p_ruid, -1);
	356
	357	/*
	358	* Free up credentials.
	359	*/
	360	if (--p->p_cred->p_refcnt == 0) {
	361	crfree(p->p_cred->pc_ucred);
	362	FREE(p->p_cred, M_SUBPROC);
	363	}
	364
	365	/*
	366	* Finally finished with old proc entry.
	367	* Unlink it from its process group and free it.
	368	*/
	369	leavepgrp(p);
	370	if (p->p_prev = p->p_nxt) / off zombproc */
	371	p->p_nxt->p_prev = p->p_prev;
	372	if (q = p->p_ysptr)
	373	q->p_osptr = p->p_osptr;
	374	if (q = p->p_osptr)
	375	q->p_ysptr = p->p_ysptr;
	376	if ((q = p->p_pptr)->p_cptr == p)
	377	q->p_cptr = p->p_osptr;
	378
	379	/*
	380	* Give machine-dependent layer a chance
	381	* to free anything that cpu_exit couldn't
	382	* release while still running in process context.
	383	*/
	384	cpu_wait(p);
	385	FREE(p, M_PROC);
	386	nprocs--;
	387	return (0);
	388	}
	389	if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
	390	(p->p_flag & STRC \|\| uap->options & WUNTRACED)) {
	391	p->p_flag \|= SWTED;
	392	retval[0] = p->p_pid;
	393	#ifdef COMPAT_43
	394	if (uap->compat) {
	395	retval[1] = W_STOPCODE(p->p_xstat);
	396	error = 0;
	397	} else
	398	#endif
	399	if (uap->status) {
	400	status = W_STOPCODE(p->p_xstat);
	401	error = copyout((caddr_t)&status,
	402	(caddr_t)uap->status, sizeof(status));
	403	} else
	404	error = 0;
	405	return (error);
	406	}
	407	}
	408	if (nfound == 0)
	409	return (ECHILD);
	410	if (uap->options & WNOHANG) {
	411	retval[0] = 0;
	412	return (0);
	413	}
	414	if (error = tsleep((caddr_t)q, PWAIT \| PCATCH, "wait", 0))
	415	return (error);
	416	goto loop;
	417	}
	418
	419	/*
	420	* make process 'parent' the new parent of process 'child'.
	421	*/
	422	void
	423	proc_reparent(child, parent)
	424	register struct proc *child;
	425	register struct proc *parent;
	426	{
	427	register struct proc *o;
	428	register struct proc *y;
	429
	430	if (child->p_pptr == parent)
	431	return;
	432
	433	/* fix up the child linkage for the old parent */
	434	o = child->p_osptr;
	435	y = child->p_ysptr;
	436	if (y)
	437	y->p_osptr = o;
	438	if (o)
	439	o->p_ysptr = y;
	440	if (child->p_pptr->p_cptr == child)
	441	child->p_pptr->p_cptr = o;
	442
	443	/* fix up child linkage for new parent */
	444	o = parent->p_cptr;
	445	if (o)
	446	o->p_ysptr = child;
	447	child->p_osptr = o;
	448	child->p_ysptr = NULL;
	449	parent->p_cptr = child;
	450	child->p_pptr = parent;
	451	}