xref: /csrg-svn/sys/kern/kern_exit.c (revision 42916)
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	7.21 (Berkeley) 06/05/90
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 #ifdef MAPMEM
90 		if (u.u_mmap)
91 			mmexit();
92 #endif
93 		vrelvm();
94 	} else {
95 		p->p_flag &= ~SVFORK;
96 		wakeup((caddr_t)p);
97 		while ((p->p_flag & SVFDONE) == 0)
98 			sleep((caddr_t)p, PZERO - 1);
99 		p->p_flag &= ~SVFDONE;
100 	}
101 	for (i = 0; i <= u.u_lastfile; i++) {
102 		struct file *f;
103 
104 		f = u.u_ofile[i];
105 		if (f) {
106 			u.u_ofile[i] = NULL;
107 			u.u_pofile[i] = 0;
108 			(void) closef(f);
109 		}
110 	}
111 	if (SESS_LEADER(p)) {
112 		register struct session *sp = p->p_session;
113 
114 		if (sp->s_ttyvp) {
115 			/*
116 			 * Controlling process.
117 			 * Signal foreground pgrp and revoke access
118 			 * to controlling terminal.
119 			 */
120 			if (sp->s_ttyp->t_pgrp)
121 				pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
122 			vgoneall(sp->s_ttyvp);
123 			vrele(sp->s_ttyvp);
124 			sp->s_ttyvp = NULL;
125 			/*
126 			 * s_ttyp is not zero'd; we use this to indicate
127 			 * that the session once had a controlling terminal.
128 			 * (for logging and informational purposes)
129 			 */
130 		}
131 		sp->s_leader = 0;
132 	}
133 	VOP_LOCK(u.u_cdir);
134 	vput(u.u_cdir);
135 	if (u.u_rdir) {
136 		VOP_LOCK(u.u_rdir);
137 		vput(u.u_rdir);
138 	}
139 	u.u_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
140 	acct();
141 	crfree(u.u_cred);
142 #ifdef KTRACE
143 	/*
144 	 * release trace file
145 	 */
146 	if (p->p_tracep)
147 		vrele(p->p_tracep);
148 #endif
149 	/*
150 	 * Freeing the user structure and kernel stack
151 	 * for the current process: have to run a bit longer
152 	 * using the pages which are about to be freed...
153 	 * vrelu will block memory allocation by raising ipl.
154 	 */
155 	vrelu(u.u_procp, 0);
156 	vrelpt(u.u_procp);
157 	if (*p->p_prev = p->p_nxt)		/* off allproc queue */
158 		p->p_nxt->p_prev = p->p_prev;
159 	if (p->p_nxt = zombproc)		/* onto zombproc */
160 		p->p_nxt->p_prev = &p->p_nxt;
161 	p->p_prev = &zombproc;
162 	zombproc = p;
163 	multprog--;
164 	p->p_stat = SZOMB;
165 	noproc = 1;
166 	for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash)
167 		if (*pp == p) {
168 			*pp = p->p_hash;
169 			goto done;
170 		}
171 	panic("exit");
172 done:
173 	if (p->p_pid == 1) {
174 		if (p->p_dsize == 0) {
175 			printf("Can't exec init (errno %d)\n", WEXITSTATUS(rv));
176 			for (;;)
177 				;
178 		} else
179 			panic("init died");
180 	}
181 	p->p_xstat = rv;
182 	*p->p_ru = u.u_ru;
183 	i = splclock();
184 	p->p_ru->ru_stime = p->p_stime;
185 	p->p_ru->ru_utime = p->p_utime;
186 	splx(i);
187 	ruadd(p->p_ru, &u.u_cru);
188 	if (p->p_cptr)		/* only need this if any child is S_ZOMB */
189 		wakeup((caddr_t)&proc[1]);
190 	fixjobc(p, 0);
191 	for (q = p->p_cptr; q != NULL; q = nq) {
192 		nq = q->p_osptr;
193 		if (nq != NULL)
194 			nq->p_ysptr = NULL;
195 		if (proc[1].p_cptr)
196 			proc[1].p_cptr->p_ysptr = q;
197 		q->p_osptr = proc[1].p_cptr;
198 		q->p_ysptr = NULL;
199 		proc[1].p_cptr = q;
200 
201 		q->p_pptr = &proc[1];
202 		q->p_ppid = 1;
203 		/*
204 		 * Traced processes are killed
205 		 * since their existence means someone is screwing up.
206 		 */
207 		if (q->p_flag&STRC) {
208 			q->p_flag &= ~STRC;
209 			psignal(q, SIGKILL);
210 		}
211 	}
212 	p->p_cptr = NULL;
213 	psignal(p->p_pptr, SIGCHLD);
214 	wakeup((caddr_t)p->p_pptr);
215 #if defined(tahoe)
216 	dkeyrelease(p->p_dkey), p->p_dkey = 0;
217 	ckeyrelease(p->p_ckey), p->p_ckey = 0;
218 	u.u_pcb.pcb_savacc.faddr = (float *)NULL;
219 #endif
220 	swtch();
221 }
222 
223 #ifdef COMPAT_43
224 owait()
225 {
226 	register struct a {
227 		int	pid;
228 		int	*status;
229 		int	options;
230 		struct	rusage *rusage;
231 		int	compat;
232 	} *uap = (struct a *)u.u_ap;
233 
234 	if ((u.u_ar0[PS] & PSL_ALLCC) != PSL_ALLCC) {
235 		uap->options = 0;
236 		uap->rusage = 0;
237 	} else {
238 		uap->options = u.u_ar0[R0];
239 		uap->rusage = (struct rusage *)u.u_ar0[R1];
240 	}
241 	uap->pid = WAIT_ANY;
242 	uap->status = 0;
243 	uap->compat = 1;
244 	u.u_error = wait1();
245 }
246 
247 wait4()
248 {
249 	register struct a {
250 		int	pid;
251 		int	*status;
252 		int	options;
253 		struct	rusage *rusage;
254 		int	compat;
255 	} *uap = (struct a *)u.u_ap;
256 
257 	uap->compat = 0;
258 	u.u_error = wait1();
259 }
260 #else
261 #define	wait1	wait4
262 #endif
263 
264 /*
265  * Wait system call.
266  * Search for a terminated (zombie) child,
267  * finally lay it to rest, and collect its status.
268  * Look also for stopped (traced) children,
269  * and pass back status from them.
270  */
271 wait1()
272 {
273 	register struct a {
274 		int	pid;
275 		int	*status;
276 		int	options;
277 		struct	rusage *rusage;
278 #ifdef COMPAT_43
279 		int compat;
280 #endif
281 	} *uap = (struct a *)u.u_ap;
282 	register f;
283 	register struct proc *p, *q;
284 	int status, error;
285 
286 	q = u.u_procp;
287 	if (uap->pid == 0)
288 		uap->pid = -q->p_pgid;
289 #ifdef notyet
290 	if (uap->options &~ (WUNTRACED|WNOHANG))
291 		return (EINVAL);
292 #endif
293 loop:
294 	f = 0;
295 	for (p = q->p_cptr; p; p = p->p_osptr) {
296 		if (uap->pid != WAIT_ANY &&
297 		    p->p_pid != uap->pid && p->p_pgid != -uap->pid)
298 			continue;
299 		f++;
300 		if (p->p_stat == SZOMB) {
301 			u.u_r.r_val1 = p->p_pid;
302 #ifdef COMPAT_43
303 			if (uap->compat)
304 				u.u_r.r_val2 = p->p_xstat;
305 			else
306 #endif
307 			if (uap->status) {
308 				status = p->p_xstat;	/* convert to int */
309 				if (error = copyout((caddr_t)&status,
310 				    (caddr_t)uap->status, sizeof(status)))
311 					return (error);
312 			}
313 			if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
314 			    (caddr_t)uap->rusage, sizeof (struct rusage))))
315 				return (error);
316 			pgrm(p);			/* off pgrp */
317 			p->p_xstat = 0;
318 			ruadd(&u.u_cru, p->p_ru);
319 			FREE(p->p_ru, M_ZOMBIE);
320 			p->p_ru = 0;
321 			p->p_stat = NULL;
322 			p->p_pid = 0;
323 			p->p_ppid = 0;
324 			if (*p->p_prev = p->p_nxt)	/* off zombproc */
325 				p->p_nxt->p_prev = p->p_prev;
326 			p->p_nxt = freeproc;		/* onto freeproc */
327 			freeproc = p;
328 			if (q = p->p_ysptr)
329 				q->p_osptr = p->p_osptr;
330 			if (q = p->p_osptr)
331 				q->p_ysptr = p->p_ysptr;
332 			if ((q = p->p_pptr)->p_cptr == p)
333 				q->p_cptr = p->p_osptr;
334 			p->p_pptr = 0;
335 			p->p_ysptr = 0;
336 			p->p_osptr = 0;
337 			p->p_cptr = 0;
338 			p->p_sig = 0;
339 			p->p_sigcatch = 0;
340 			p->p_sigignore = 0;
341 			p->p_sigmask = 0;
342 			/*p->p_pgrp = 0;*/
343 			p->p_flag = 0;
344 			p->p_wchan = 0;
345 			p->p_cursig = 0;
346 			return (0);
347 		}
348 		if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 &&
349 		    (p->p_flag & STRC || uap->options & WUNTRACED)) {
350 			p->p_flag |= SWTED;
351 			u.u_r.r_val1 = p->p_pid;
352 #ifdef COMPAT_43
353 			if (uap->compat) {
354 				u.u_r.r_val2 = W_STOPCODE(p->p_cursig);
355 				error = 0;
356 			} else
357 #endif
358 			if (uap->status) {
359 				status = W_STOPCODE(p->p_cursig);
360 				error = copyout((caddr_t)&status,
361 				    (caddr_t)uap->status, sizeof(status));
362 			} else
363 				error = 0;
364 			return (error);
365 		}
366 	}
367 	if (f == 0)
368 		return (ECHILD);
369 	if (uap->options & WNOHANG) {
370 		u.u_r.r_val1 = 0;
371 		return (0);
372 	}
373 	if (error = tsleep((caddr_t)u.u_procp, PWAIT | PCATCH, "wait", 0))
374 		return (error);
375 	goto loop;
376 }
377