xref: /csrg-svn/sys/kern/kern_exit.c (revision 41104)
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	7.18 (Berkeley) 04/27/90
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 struct proc **pp;
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 		if (p->p_session->s_ttyvp) {
110 			vgoneall(p->p_session->s_ttyvp);
111 			vrele(p->p_session->s_ttyvp);
112 			p->p_session->s_ttyvp = NULL;
113 			/*
114 			 * s_ttyp is not zero'd; we use this to indicate
115 			 * that the session once had a controlling terminal.
116 			 */
117 		}
118 	}
119 	VOP_LOCK(u.u_cdir);
120 	vput(u.u_cdir);
121 	if (u.u_rdir) {
122 		VOP_LOCK(u.u_rdir);
123 		vput(u.u_rdir);
124 	}
125 	u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
126 	acct();
127 	crfree(u.u_cred);
128 #ifdef KTRACE
129 	/*
130 	 * release trace file
131 	 */
132 	if (p->p_tracep)
133 		vrele(p->p_tracep);
134 #endif
135 	/*
136 	/*
137 	 * Freeing the user structure and kernel stack
138 	 * for the current process: have to run a bit longer
139 	 * using the pages which are about to be freed...
140 	 * vrelu will block memory allocation by raising ipl.
141 	 */
142 	vrelu(u.u_procp, 0);
143 	vrelpt(u.u_procp);
144 	if (*p->p_prev = p->p_nxt)		/* off allproc queue */
145 		p->p_nxt->p_prev = p->p_prev;
146 	if (p->p_nxt = zombproc)		/* onto zombproc */
147 		p->p_nxt->p_prev = &p->p_nxt;
148 	p->p_prev = &zombproc;
149 	zombproc = p;
150 	multprog--;
151 	p->p_stat = SZOMB;
152 	noproc = 1;
153 	for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash)
154 		if (*pp == p) {
155 			*pp = p->p_hash;
156 			goto done;
157 		}
158 	panic("exit");
159 done:
160 	if (p->p_pid == 1) {
161 		if (p->p_dsize == 0) {
162 			printf("Can't exec init (errno %d)\n", WEXITSTATUS(rv));
163 			for (;;)
164 				;
165 		} else
166 			panic("init died");
167 	}
168 	p->p_xstat = rv;
169 	*p->p_ru = u.u_ru;
170 	i = splclock();
171 	p->p_ru->ru_stime = p->p_stime;
172 	p->p_ru->ru_utime = p->p_utime;
173 	splx(i);
174 	ruadd(p->p_ru, &u.u_cru);
175 	if (p->p_cptr)		/* only need this if any child is S_ZOMB */
176 		wakeup((caddr_t)&proc[1]);
177 	if (PGRP_JOBC(p))
178 		p->p_pgrp->pg_jobc--;
179 	for (q = p->p_cptr; q != NULL; q = nq) {
180 		if (PGRP_JOBC(q))
181 			q->p_pgrp->pg_jobc--;
182 		nq = q->p_osptr;
183 		if (nq != NULL)
184 			nq->p_ysptr = NULL;
185 		if (proc[1].p_cptr)
186 			proc[1].p_cptr->p_ysptr = q;
187 		q->p_osptr = proc[1].p_cptr;
188 		q->p_ysptr = NULL;
189 		proc[1].p_cptr = q;
190 
191 		q->p_pptr = &proc[1];
192 		q->p_ppid = 1;
193 		/*
194 		 * Traced processes are killed
195 		 * since their existence means someone is screwing up.
196 		 * Stopped processes are sent a hangup and a continue.
197 		 * This is designed to be ``safe'' for setuid
198 		 * processes since they must be willing to tolerate
199 		 * hangups anyways.
200 		 */
201 		if (q->p_flag&STRC) {
202 			q->p_flag &= ~STRC;
203 			psignal(q, SIGKILL);
204 		} else if (q->p_stat == SSTOP) {
205 			psignal(q, SIGHUP);
206 			psignal(q, SIGCONT);
207 		}
208 		/*
209 		 * Protect this process from future
210 		 * tty signals, clear TSTP/TTIN/TTOU if pending.
211 		 */
212 		(void) spgrp(q);
213 	}
214 	p->p_cptr = NULL;
215 	psignal(p->p_pptr, SIGCHLD);
216 	wakeup((caddr_t)p->p_pptr);
217 #if defined(tahoe)
218 	dkeyrelease(p->p_dkey), p->p_dkey = 0;
219 	ckeyrelease(p->p_ckey), p->p_ckey = 0;
220 	u.u_pcb.pcb_savacc.faddr = (float *)NULL;
221 #endif
222 	swtch();
223 }
224 
225 #ifdef COMPAT_43
226 owait()
227 {
228 	register struct a {
229 		int	pid;
230 		int	*status;
231 		int	options;
232 		struct	rusage *rusage;
233 		int	compat;
234 	} *uap = (struct a *)u.u_ap;
235 
236 	if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
237 		uap->options = 0;
238 		uap->rusage = 0;
239 	} else {
240 		uap->options = u.u_ar0[R0];
241 		uap->rusage = (struct rusage *)u.u_ar0[R1];
242 	}
243 	uap->pid = WAIT_ANY;
244 	uap->status = 0;
245 	uap->compat = 1;
246 	u.u_error = wait1();
247 }
248 
249 wait4()
250 {
251 	register struct a {
252 		int	pid;
253 		int	*status;
254 		int	options;
255 		struct	rusage *rusage;
256 		int	compat;
257 	} *uap = (struct a *)u.u_ap;
258 
259 	uap->compat = 0;
260 	u.u_error = wait1();
261 }
262 #else
263 #define	wait1	wait4
264 #endif
265 
266 /*
267  * Wait system call.
268  * Search for a terminated (zombie) child,
269  * finally lay it to rest, and collect its status.
270  * Look also for stopped (traced) children,
271  * and pass back status from them.
272  */
273 wait1()
274 {
275 	register struct a {
276 		int	pid;
277 		int	*status;
278 		int	options;
279 		struct	rusage *rusage;
280 #ifdef COMPAT_43
281 		int compat;
282 #endif
283 	} *uap = (struct a *)u.u_ap;
284 	register f;
285 	register struct proc *p, *q;
286 	int status, error;
287 
288 	q = u.u_procp;
289 	if (uap->pid == 0)
290 		uap->pid = -q->p_pgid;
291 #ifdef notyet
292 	if (uap->options &~ (WUNTRACED|WNOHANG))
293 		return (EINVAL);
294 #endif
295 loop:
296 	f = 0;
297 	for (p = q->p_cptr; p; p = p->p_osptr) {
298 		if (uap->pid != WAIT_ANY &&
299 		    p->p_pid != uap->pid && p->p_pgid != -uap->pid)
300 			continue;
301 		f++;
302 		if (p->p_stat == SZOMB) {
303 			u.u_r.r_val1 = p->p_pid;
304 #ifdef COMPAT_43
305 			if (uap->compat)
306 				u.u_r.r_val2 = p->p_xstat;
307 			else
308 #endif
309 			if (uap->status) {
310 				status = p->p_xstat;	/* convert to int */
311 				if (error = copyout((caddr_t)&status,
312 				    (caddr_t)uap->status, sizeof(status)))
313 					return (error);
314 			}
315 			if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
316 			    (caddr_t)uap->rusage, sizeof (struct rusage))))
317 				return (error);
318 			pgrm(p);			/* off pgrp */
319 			p->p_xstat = 0;
320 			ruadd(&u.u_cru, p->p_ru);
321 			FREE(p->p_ru, M_ZOMBIE);
322 			p->p_ru = 0;
323 			p->p_stat = NULL;
324 			p->p_pid = 0;
325 			p->p_ppid = 0;
326 			if (*p->p_prev = p->p_nxt)	/* off zombproc */
327 				p->p_nxt->p_prev = p->p_prev;
328 			p->p_nxt = freeproc;		/* onto freeproc */
329 			freeproc = p;
330 			if (q = p->p_ysptr)
331 				q->p_osptr = p->p_osptr;
332 			if (q = p->p_osptr)
333 				q->p_ysptr = p->p_ysptr;
334 			if ((q = p->p_pptr)->p_cptr == p)
335 				q->p_cptr = p->p_osptr;
336 			p->p_pptr = 0;
337 			p->p_ysptr = 0;
338 			p->p_osptr = 0;
339 			p->p_cptr = 0;
340 			p->p_sig = 0;
341 			p->p_sigcatch = 0;
342 			p->p_sigignore = 0;
343 			p->p_sigmask = 0;
344 			/*p->p_pgrp = 0;*/
345 			p->p_flag = 0;
346 			p->p_wchan = 0;
347 			p->p_cursig = 0;
348 			return (0);
349 		}
350 		if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
351 		    (p->p_flag & STRC || uap->options & WUNTRACED)) {
352 			p->p_flag |= SWTED;
353 			u.u_r.r_val1 = p->p_pid;
354 #ifdef COMPAT_43
355 			if (uap->compat) {
356 				u.u_r.r_val2 = W_STOPCODE(p->p_cursig);
357 				error = 0;
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 (error = tsleep((caddr_t)u.u_procp, PWAIT | PCATCH, "wait", 0))
376 		return (error);
377 	goto loop;
378 }
379