xref: /csrg-svn/sys/kern/kern_exit.c (revision 39410)
1 /*
2  * Copyright (c) 1982, 1986, 1989 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  *
17  *	@(#)kern_exit.c	7.10 (Berkeley) 10/27/89
18  */
19 
20 #include "param.h"
21 #include "systm.h"
22 #include "map.h"
23 #include "user.h"
24 #include "kernel.h"
25 #include "proc.h"
26 #include "buf.h"
27 #include "wait.h"
28 #include "vm.h"
29 #include "file.h"
30 #include "vnode.h"
31 #include "ioctl.h"
32 #include "tty.h"
33 #include "syslog.h"
34 #include "malloc.h"
35 
36 #include "machine/reg.h"
37 #ifdef COMPAT_43
38 #include "machine/psl.h"
39 #endif
40 
41 /*
42  * Exit system call: pass back caller's arg
43  */
44 rexit()
45 {
46 	struct a {
47 		int	rval;
48 	} *uap;
49 
50 	uap = (struct a *)u.u_ap;
51 	exit(W_EXITCODE(uap->rval, 0));
52 }
53 
54 /*
55  * Release resources.
56  * Save u. area for parent to look at.
57  * Enter zombie state.
58  * Wake up parent and init processes,
59  * and dispose of children.
60  */
61 exit(rv)
62 	int rv;
63 {
64 	register int i;
65 	register struct proc *p, *q, *nq;
66 	register int x;
67 
68 #ifdef PGINPROF
69 	vmsizmon();
70 #endif
71 	p = u.u_procp;
72 	MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
73 		M_ZOMBIE, M_WAITOK);
74 	p->p_flag &= ~(STRC|SULOCK);
75 	p->p_flag |= SWEXIT;
76 	p->p_sigignore = ~0;
77 	p->p_sig = 0;
78 	p->p_cpticks = 0;
79 	p->p_pctcpu = 0;
80 	for (i = 0; i < NSIG; i++)
81 		u.u_signal[i] = SIG_IGN;
82 	untimeout(realitexpire, (caddr_t)p);
83 	/*
84 	 * Release virtual memory.  If we resulted from
85 	 * a vfork(), instead give the resources back to
86 	 * the parent.
87 	 */
88 	if ((p->p_flag & SVFORK) == 0)
89 		vrelvm();
90 	else {
91 		p->p_flag &= ~SVFORK;
92 		wakeup((caddr_t)p);
93 		while ((p->p_flag & SVFDONE) == 0)
94 			sleep((caddr_t)p, PZERO - 1);
95 		p->p_flag &= ~SVFDONE;
96 	}
97 	for (i = 0; i <= u.u_lastfile; i++) {
98 		struct file *f;
99 
100 		f = u.u_ofile[i];
101 		if (f) {
102 			u.u_ofile[i] = NULL;
103 			u.u_pofile[i] = 0;
104 			(void) closef(f);
105 		}
106 	}
107 	if (SESS_LEADER(p)) {
108 		p->p_session->s_leader = 0;
109 		/* TODO: vhangup(); */
110 		if (u.u_ttyp) {
111 			u.u_ttyp->t_session = 0;
112 			u.u_ttyp->t_pgid = 0;
113 		}
114 	}
115 	VOP_LOCK(u.u_cdir);
116 	vput(u.u_cdir);
117 	if (u.u_rdir) {
118 		VOP_LOCK(u.u_rdir);
119 		vput(u.u_rdir);
120 	}
121 	u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
122 	acct();
123 #ifdef QUOTA
124 	qclean();
125 #endif
126 	crfree(u.u_cred);
127 #ifdef KTRACE
128 	/*
129 	 * release trace file
130 	 */
131 	if (p->p_tracep)
132 		vrele(p->p_tracep);
133 #endif
134 	/*
135 	/*
136 	 * Freeing the user structure and kernel stack
137 	 * for the current process: have to run a bit longer
138 	 * using the pages which are about to be freed...
139 	 * vrelu will block memory allocation by raising ipl.
140 	 */
141 	vrelu(u.u_procp, 0);
142 	vrelpt(u.u_procp);
143 	if (*p->p_prev = p->p_nxt)		/* off allproc queue */
144 		p->p_nxt->p_prev = p->p_prev;
145 	if (p->p_nxt = zombproc)		/* onto zombproc */
146 		p->p_nxt->p_prev = &p->p_nxt;
147 	p->p_prev = &zombproc;
148 	zombproc = p;
149 	multprog--;
150 	p->p_stat = SZOMB;
151 	noproc = 1;
152 	i = PIDHASH(p->p_pid);
153 	x = p - proc;
154 	if (pidhash[i] == x)
155 		pidhash[i] = p->p_idhash;
156 	else {
157 		for (i = pidhash[i]; i != 0; i = proc[i].p_idhash)
158 			if (proc[i].p_idhash == x) {
159 				proc[i].p_idhash = p->p_idhash;
160 				goto done;
161 			}
162 		panic("exit");
163 	}
164 	if (p->p_pid == 1) {
165 		if (p->p_dsize == 0) {
166 			printf("Can't exec init (errno %d)\n", WEXITSTATUS(rv));
167 			for (;;)
168 				;
169 		} else
170 			panic("init died");
171 	}
172 done:
173 	p->p_xstat = rv;
174 	*p->p_ru = u.u_ru;
175 	ruadd(p->p_ru, &u.u_cru);
176 	if (p->p_cptr)		/* only need this if any child is S_ZOMB */
177 		wakeup((caddr_t)&proc[1]);
178 	if (PGRP_JOBC(p))
179 		p->p_pgrp->pg_jobc--;
180 	for (q = p->p_cptr; q != NULL; q = nq) {
181 		if (PGRP_JOBC(q))
182 			q->p_pgrp->pg_jobc--;
183 		nq = q->p_osptr;
184 		if (nq != NULL)
185 			nq->p_ysptr = NULL;
186 		if (proc[1].p_cptr)
187 			proc[1].p_cptr->p_ysptr = q;
188 		q->p_osptr = proc[1].p_cptr;
189 		q->p_ysptr = NULL;
190 		proc[1].p_cptr = q;
191 
192 		q->p_pptr = &proc[1];
193 		q->p_ppid = 1;
194 		/*
195 		 * Traced processes are killed
196 		 * since their existence means someone is screwing up.
197 		 * Stopped processes are sent a hangup and a continue.
198 		 * This is designed to be ``safe'' for setuid
199 		 * processes since they must be willing to tolerate
200 		 * hangups anyways.
201 		 */
202 		if (q->p_flag&STRC) {
203 			q->p_flag &= ~STRC;
204 			psignal(q, SIGKILL);
205 		} else if (q->p_stat == SSTOP) {
206 			psignal(q, SIGHUP);
207 			psignal(q, SIGCONT);
208 		}
209 		/*
210 		 * Protect this process from future
211 		 * tty signals, clear TSTP/TTIN/TTOU if pending.
212 		 */
213 		(void) spgrp(q);
214 	}
215 	p->p_cptr = NULL;
216 	psignal(p->p_pptr, SIGCHLD);
217 	wakeup((caddr_t)p->p_pptr);
218 #if defined(tahoe)
219 	dkeyrelease(p->p_dkey), p->p_dkey = 0;
220 	ckeyrelease(p->p_ckey), p->p_ckey = 0;
221 	u.u_pcb.pcb_savacc.faddr = (float *)NULL;
222 #endif
223 	swtch();
224 }
225 
226 #ifdef COMPAT_43
227 owait()
228 {
229 	register struct a {
230 		int	pid;
231 		int	*status;
232 		int	options;
233 		struct	rusage *rusage;
234 		int	compat;
235 	} *uap = (struct a *)u.u_ap;
236 
237 	if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
238 		uap->options = 0;
239 		uap->rusage = 0;
240 	} else {
241 		uap->options = u.u_ar0[R0];
242 		uap->rusage = (struct rusage *)u.u_ar0[R1];
243 	}
244 	uap->pid = WAIT_ANY;
245 	uap->status = 0;
246 	uap->compat = 1;
247 	u.u_error = wait1();
248 }
249 
250 wait4()
251 {
252 	register struct a {
253 		int	pid;
254 		int	*status;
255 		int	options;
256 		struct	rusage *rusage;
257 		int	compat;
258 	} *uap = (struct a *)u.u_ap;
259 
260 	uap->compat = 0;
261 	u.u_error = wait1();
262 }
263 #else
264 #define	wait1	wait4
265 #endif
266 
267 /*
268  * Wait system call.
269  * Search for a terminated (zombie) child,
270  * finally lay it to rest, and collect its status.
271  * Look also for stopped (traced) children,
272  * and pass back status from them.
273  */
274 wait1()
275 {
276 	register struct a {
277 		int	pid;
278 		int	*status;
279 		int	options;
280 		struct	rusage *rusage;
281 #ifdef COMPAT_43
282 		int compat;
283 #endif
284 	} *uap = (struct a *)u.u_ap;
285 	register f;
286 	register struct proc *p, *q;
287 	int status, error;
288 
289 	q = u.u_procp;
290 	if (uap->pid == 0)
291 		uap->pid = -q->p_pgid;
292 #ifdef notyet
293 	if (uap->options &~ (WUNTRACED|WNOHANG))
294 		return (EINVAL);
295 #endif
296 loop:
297 	f = 0;
298 	for (p = q->p_cptr; p; p = p->p_osptr) {
299 		if (uap->pid != WAIT_ANY &&
300 		    p->p_pid != uap->pid && p->p_pgid != -uap->pid)
301 			continue;
302 		f++;
303 		if (p->p_stat == SZOMB) {
304 			u.u_r.r_val1 = p->p_pid;
305 #ifdef COMPAT_43
306 			if (uap->compat)
307 				u.u_r.r_val2 = p->p_xstat;
308 			else
309 #endif
310 			if (uap->status) {
311 				status = p->p_xstat;	/* convert to int */
312 				if (error = copyout((caddr_t)&status,
313 				    (caddr_t)uap->status, sizeof(status)))
314 					return (error);
315 			}
316 			if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
317 			    (caddr_t)uap->rusage, sizeof (struct rusage))))
318 				return (error);
319 			pgrm(p);			/* off pgrp */
320 			p->p_xstat = 0;
321 			ruadd(&u.u_cru, p->p_ru);
322 			FREE(p->p_ru, M_ZOMBIE);
323 			p->p_ru = 0;
324 			p->p_stat = NULL;
325 			p->p_pid = 0;
326 			p->p_ppid = 0;
327 			if (*p->p_prev = p->p_nxt)	/* off zombproc */
328 				p->p_nxt->p_prev = p->p_prev;
329 			p->p_nxt = freeproc;		/* onto freeproc */
330 			freeproc = p;
331 			if (q = p->p_ysptr)
332 				q->p_osptr = p->p_osptr;
333 			if (q = p->p_osptr)
334 				q->p_ysptr = p->p_ysptr;
335 			if ((q = p->p_pptr)->p_cptr == p)
336 				q->p_cptr = p->p_osptr;
337 			p->p_pptr = 0;
338 			p->p_ysptr = 0;
339 			p->p_osptr = 0;
340 			p->p_cptr = 0;
341 			p->p_sig = 0;
342 			p->p_sigcatch = 0;
343 			p->p_sigignore = 0;
344 			p->p_sigmask = 0;
345 			/*p->p_pgrp = 0;*/
346 			p->p_flag = 0;
347 			p->p_wchan = 0;
348 			p->p_cursig = 0;
349 			return (0);
350 		}
351 		if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
352 		    (p->p_flag & STRC || uap->options & WUNTRACED)) {
353 			p->p_flag |= SWTED;
354 			u.u_r.r_val1 = p->p_pid;
355 #ifdef COMPAT_43
356 			if (uap->compat)
357 				u.u_r.r_val2 = W_STOPCODE(p->p_cursig);
358 			else
359 #endif
360 			if (uap->status) {
361 				status = W_STOPCODE(p->p_cursig);
362 				error = copyout((caddr_t)&status,
363 				    (caddr_t)uap->status, sizeof(status));
364 			} else
365 				error = 0;
366 			return (error);
367 		}
368 	}
369 	if (f == 0)
370 		return (ECHILD);
371 	if (uap->options & WNOHANG) {
372 		u.u_r.r_val1 = 0;
373 		return (0);
374 	}
375 	if (setjmp(&u.u_qsave)) {
376 		p = u.u_procp;
377 		if ((u.u_sigintr & sigmask(p->p_cursig)) != 0)
378 			return (EINTR);
379 		u.u_eosys = RESTARTSYS;
380 		return (0);
381 	}
382 	sleep((caddr_t)u.u_procp, PWAIT);
383 	goto loop;
384 }
385