Initial import from FreeBSD RELENG_4:
[dragonfly.git] / sys / kern / kern_exit.c
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1/*
2 * Copyright (c) 1982, 1986, 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * @(#)kern_exit.c 8.7 (Berkeley) 2/12/94
39 * $FreeBSD: src/sys/kern/kern_exit.c,v 1.92.2.11 2003/01/13 22:51:16 dillon Exp $
40 */
41
42#include "opt_compat.h"
43#include "opt_ktrace.h"
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/sysproto.h>
48#include <sys/kernel.h>
49#include <sys/malloc.h>
50#include <sys/proc.h>
51#include <sys/pioctl.h>
52#include <sys/tty.h>
53#include <sys/wait.h>
54#include <sys/vnode.h>
55#include <sys/resourcevar.h>
56#include <sys/signalvar.h>
57#include <sys/ptrace.h>
58#include <sys/acct.h> /* for acct_process() function prototype */
59#include <sys/filedesc.h>
60#include <sys/shm.h>
61#include <sys/sem.h>
62#include <sys/aio.h>
63#include <sys/jail.h>
64
65#include <vm/vm.h>
66#include <vm/vm_param.h>
67#include <sys/lock.h>
68#include <vm/pmap.h>
69#include <vm/vm_map.h>
70#include <vm/vm_zone.h>
71#include <vm/vm_extern.h>
72#include <sys/user.h>
73
74/* Required to be non-static for SysVR4 emulator */
75MALLOC_DEFINE(M_ZOMBIE, "zombie", "zombie proc status");
76
77static MALLOC_DEFINE(M_ATEXIT, "atexit", "atexit callback");
78
79static int wait1 __P((struct proc *, struct wait_args *, int));
80
81/*
82 * callout list for things to do at exit time
83 */
84struct exitlist {
85 exitlist_fn function;
86 TAILQ_ENTRY(exitlist) next;
87};
88
89TAILQ_HEAD(exit_list_head, exitlist);
90static struct exit_list_head exit_list = TAILQ_HEAD_INITIALIZER(exit_list);
91
92/*
93 * exit --
94 * Death of process.
95 */
96void
97sys_exit(p, uap)
98 struct proc *p;
99 struct sys_exit_args /* {
100 int rval;
101 } */ *uap;
102{
103
104 exit1(p, W_EXITCODE(uap->rval, 0));
105 /* NOTREACHED */
106}
107
108/*
109 * Exit: deallocate address space and other resources, change proc state
110 * to zombie, and unlink proc from allproc and parent's lists. Save exit
111 * status and rusage for wait(). Check for child processes and orphan them.
112 */
113void
114exit1(p, rv)
115 register struct proc *p;
116 int rv;
117{
118 register struct proc *q, *nq;
119 register struct vmspace *vm;
120 struct vnode *vtmp;
121 struct exitlist *ep;
122
123 if (p->p_pid == 1) {
124 printf("init died (signal %d, exit %d)\n",
125 WTERMSIG(rv), WEXITSTATUS(rv));
126 panic("Going nowhere without my init!");
127 }
128
129 aio_proc_rundown(p);
130
131 /* are we a task leader? */
132 if(p == p->p_leader) {
133 struct kill_args killArgs;
134 killArgs.signum = SIGKILL;
135 q = p->p_peers;
136 while(q) {
137 killArgs.pid = q->p_pid;
138 /*
139 * The interface for kill is better
140 * than the internal signal
141 */
142 kill(p, &killArgs);
143 nq = q;
144 q = q->p_peers;
145 }
146 while (p->p_peers)
147 tsleep((caddr_t)p, PWAIT, "exit1", 0);
148 }
149
150#ifdef PGINPROF
151 vmsizmon();
152#endif
153 STOPEVENT(p, S_EXIT, rv);
154 wakeup(&p->p_stype); /* Wakeup anyone in procfs' PIOCWAIT */
155
156 /*
157 * Check if any loadable modules need anything done at process exit.
158 * e.g. SYSV IPC stuff
159 * XXX what if one of these generates an error?
160 */
161 TAILQ_FOREACH(ep, &exit_list, next)
162 (*ep->function)(p);
163
164 if (p->p_flag & P_PROFIL)
165 stopprofclock(p);
166 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage),
167 M_ZOMBIE, M_WAITOK);
168 /*
169 * If parent is waiting for us to exit or exec,
170 * P_PPWAIT is set; we will wakeup the parent below.
171 */
172 p->p_flag &= ~(P_TRACED | P_PPWAIT);
173 p->p_flag |= P_WEXIT;
174 SIGEMPTYSET(p->p_siglist);
175 if (timevalisset(&p->p_realtimer.it_value))
176 untimeout(realitexpire, (caddr_t)p, p->p_ithandle);
177
178 /*
179 * Reset any sigio structures pointing to us as a result of
180 * F_SETOWN with our pid.
181 */
182 funsetownlst(&p->p_sigiolst);
183
184 /*
185 * Close open files and release open-file table.
186 * This may block!
187 */
188 fdfree(p);
189
190 if(p->p_leader->p_peers) {
191 q = p->p_leader;
192 while(q->p_peers != p)
193 q = q->p_peers;
194 q->p_peers = p->p_peers;
195 wakeup((caddr_t)p->p_leader);
196 }
197
198 /*
199 * XXX Shutdown SYSV semaphores
200 */
201 semexit(p);
202
203 /* The next two chunks should probably be moved to vmspace_exit. */
204 vm = p->p_vmspace;
205 /*
206 * Release user portion of address space.
207 * This releases references to vnodes,
208 * which could cause I/O if the file has been unlinked.
209 * Need to do this early enough that we can still sleep.
210 * Can't free the entire vmspace as the kernel stack
211 * may be mapped within that space also.
212 *
213 * Processes sharing the same vmspace may exit in one order, and
214 * get cleaned up by vmspace_exit() in a different order. The
215 * last exiting process to reach this point releases as much of
216 * the environment as it can, and the last process cleaned up
217 * by vmspace_exit() (which decrements exitingcnt) cleans up the
218 * remainder.
219 */
220 ++vm->vm_exitingcnt;
221 if (--vm->vm_refcnt == 0) {
222 if (vm->vm_shm)
223 shmexit(p);
224 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_ADDRESS,
225 VM_MAXUSER_ADDRESS);
226 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS,
227 VM_MAXUSER_ADDRESS);
228 }
229
230 if (SESS_LEADER(p)) {
231 register struct session *sp = p->p_session;
232
233 if (sp->s_ttyvp) {
234 /*
235 * Controlling process.
236 * Signal foreground pgrp,
237 * drain controlling terminal
238 * and revoke access to controlling terminal.
239 */
240 if (sp->s_ttyp && (sp->s_ttyp->t_session == sp)) {
241 if (sp->s_ttyp->t_pgrp)
242 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1);
243 (void) ttywait(sp->s_ttyp);
244 /*
245 * The tty could have been revoked
246 * if we blocked.
247 */
248 if (sp->s_ttyvp)
249 VOP_REVOKE(sp->s_ttyvp, REVOKEALL);
250 }
251 if (sp->s_ttyvp)
252 vrele(sp->s_ttyvp);
253 sp->s_ttyvp = NULL;
254 /*
255 * s_ttyp is not zero'd; we use this to indicate
256 * that the session once had a controlling terminal.
257 * (for logging and informational purposes)
258 */
259 }
260 sp->s_leader = NULL;
261 }
262 fixjobc(p, p->p_pgrp, 0);
263 (void)acct_process(p);
264#ifdef KTRACE
265 /*
266 * release trace file
267 */
268 p->p_traceflag = 0; /* don't trace the vrele() */
269 if ((vtmp = p->p_tracep) != NULL) {
270 p->p_tracep = NULL;
271 vrele(vtmp);
272 }
273#endif
274 /*
275 * Release reference to text vnode
276 */
277 if ((vtmp = p->p_textvp) != NULL) {
278 p->p_textvp = NULL;
279 vrele(vtmp);
280 }
281
282 /*
283 * Remove proc from allproc queue and pidhash chain.
284 * Place onto zombproc. Unlink from parent's child list.
285 */
286 LIST_REMOVE(p, p_list);
287 LIST_INSERT_HEAD(&zombproc, p, p_list);
288 p->p_stat = SZOMB;
289
290 LIST_REMOVE(p, p_hash);
291
292 q = LIST_FIRST(&p->p_children);
293 if (q) /* only need this if any child is S_ZOMB */
294 wakeup((caddr_t) initproc);
295 for (; q != 0; q = nq) {
296 nq = LIST_NEXT(q, p_sibling);
297 LIST_REMOVE(q, p_sibling);
298 LIST_INSERT_HEAD(&initproc->p_children, q, p_sibling);
299 q->p_pptr = initproc;
300 q->p_sigparent = SIGCHLD;
301 /*
302 * Traced processes are killed
303 * since their existence means someone is screwing up.
304 */
305 if (q->p_flag & P_TRACED) {
306 q->p_flag &= ~P_TRACED;
307 psignal(q, SIGKILL);
308 }
309 }
310
311 /*
312 * Save exit status and final rusage info, adding in child rusage
313 * info and self times.
314 */
315 p->p_xstat = rv;
316 *p->p_ru = p->p_stats->p_ru;
317 calcru(p, &p->p_ru->ru_utime, &p->p_ru->ru_stime, NULL);
318 ruadd(p->p_ru, &p->p_stats->p_cru);
319
320 /*
321 * Pretend that an mi_switch() to the next process occurs now. We
322 * must set `switchtime' directly since we will call cpu_switch()
323 * directly. Set it now so that the rest of the exit time gets
324 * counted somewhere if possible.
325 */
326 microuptime(&switchtime);
327 switchticks = ticks;
328
329 /*
330 * notify interested parties of our demise.
331 */
332 KNOTE(&p->p_klist, NOTE_EXIT);
333
334 /*
335 * Notify parent that we're gone. If parent has the PS_NOCLDWAIT
336 * flag set, notify process 1 instead (and hope it will handle
337 * this situation).
338 */
339 if (p->p_pptr->p_procsig->ps_flag & PS_NOCLDWAIT) {
340 struct proc *pp = p->p_pptr;
341 proc_reparent(p, initproc);
342 /*
343 * If this was the last child of our parent, notify
344 * parent, so in case he was wait(2)ing, he will
345 * continue.
346 */
347 if (LIST_EMPTY(&pp->p_children))
348 wakeup((caddr_t)pp);
349 }
350
351 if (p->p_sigparent && p->p_pptr != initproc) {
352 psignal(p->p_pptr, p->p_sigparent);
353 } else {
354 psignal(p->p_pptr, SIGCHLD);
355 }
356
357 wakeup((caddr_t)p->p_pptr);
358#if defined(tahoe)
359 /* move this to cpu_exit */
360 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL;
361#endif
362 /*
363 * Clear curproc after we've done all operations
364 * that could block, and before tearing down the rest
365 * of the process state that might be used from clock, etc.
366 * Also, can't clear curproc while we're still runnable,
367 * as we're not on a run queue (we are current, just not
368 * a proper proc any longer!).
369 *
370 * Other substructures are freed from wait().
371 */
372 SET_CURPROC(NULL);
373 if (--p->p_limit->p_refcnt == 0) {
374 FREE(p->p_limit, M_SUBPROC);
375 p->p_limit = NULL;
376 }
377
378 /*
379 * Finally, call machine-dependent code to release the remaining
380 * resources including address space, the kernel stack and pcb.
381 * The address space is released by "vmspace_free(p->p_vmspace)";
382 * This is machine-dependent, as we may have to change stacks
383 * or ensure that the current one isn't reallocated before we
384 * finish. cpu_exit will end with a call to cpu_switch(), finishing
385 * our execution (pun intended).
386 */
387 cpu_exit(p);
388}
389
390#ifdef COMPAT_43
391int
392owait(p, uap)
393 struct proc *p;
394 register struct owait_args /* {
395 int dummy;
396 } */ *uap;
397{
398 struct wait_args w;
399
400 w.options = 0;
401 w.rusage = NULL;
402 w.pid = WAIT_ANY;
403 w.status = NULL;
404 return (wait1(p, &w, 1));
405}
406#endif /* COMPAT_43 */
407
408int
409wait4(p, uap)
410 struct proc *p;
411 struct wait_args *uap;
412{
413
414 return (wait1(p, uap, 0));
415}
416
417static int
418wait1(q, uap, compat)
419 register struct proc *q;
420 register struct wait_args /* {
421 int pid;
422 int *status;
423 int options;
424 struct rusage *rusage;
425 } */ *uap;
426 int compat;
427{
428 register int nfound;
429 register struct proc *p, *t;
430 int status, error;
431
432 if (uap->pid == 0)
433 uap->pid = -q->p_pgid;
434 if (uap->options &~ (WUNTRACED|WNOHANG|WLINUXCLONE))
435 return (EINVAL);
436loop:
437 nfound = 0;
438 LIST_FOREACH(p, &q->p_children, p_sibling) {
439 if (uap->pid != WAIT_ANY &&
440 p->p_pid != uap->pid && p->p_pgid != -uap->pid)
441 continue;
442
443 /* This special case handles a kthread spawned by linux_clone
444 * (see linux_misc.c). The linux_wait4 and linux_waitpid functions
445 * need to be able to distinguish between waiting on a process and
446 * waiting on a thread. It is a thread if p_sigparent is not SIGCHLD,
447 * and the WLINUXCLONE option signifies we want to wait for threads
448 * and not processes.
449 */
450 if ((p->p_sigparent != SIGCHLD) ^ ((uap->options & WLINUXCLONE) != 0))
451 continue;
452
453 nfound++;
454 if (p->p_stat == SZOMB) {
455 /* charge childs scheduling cpu usage to parent */
456 if (curproc->p_pid != 1) {
457 curproc->p_estcpu =
458 ESTCPULIM(curproc->p_estcpu + p->p_estcpu);
459 }
460
461 q->p_retval[0] = p->p_pid;
462#ifdef COMPAT_43
463 if (compat)
464 q->p_retval[1] = p->p_xstat;
465 else
466#endif
467 if (uap->status) {
468 status = p->p_xstat; /* convert to int */
469 if ((error = copyout((caddr_t)&status,
470 (caddr_t)uap->status, sizeof(status))))
471 return (error);
472 }
473 if (uap->rusage && (error = copyout((caddr_t)p->p_ru,
474 (caddr_t)uap->rusage, sizeof (struct rusage))))
475 return (error);
476 /*
477 * If we got the child via a ptrace 'attach',
478 * we need to give it back to the old parent.
479 */
480 if (p->p_oppid && (t = pfind(p->p_oppid))) {
481 p->p_oppid = 0;
482 proc_reparent(p, t);
483 psignal(t, SIGCHLD);
484 wakeup((caddr_t)t);
485 return (0);
486 }
487 p->p_xstat = 0;
488 ruadd(&q->p_stats->p_cru, p->p_ru);
489 FREE(p->p_ru, M_ZOMBIE);
490 p->p_ru = NULL;
491
492 /*
493 * Decrement the count of procs running with this uid.
494 */
495 (void)chgproccnt(p->p_cred->p_uidinfo, -1, 0);
496
497 /*
498 * Free up credentials.
499 */
500 if (--p->p_cred->p_refcnt == 0) {
501 crfree(p->p_ucred);
502 uifree(p->p_cred->p_uidinfo);
503 FREE(p->p_cred, M_SUBPROC);
504 p->p_cred = NULL;
505 }
506
507 /*
508 * Destroy empty prisons
509 */
510 if (p->p_prison && !--p->p_prison->pr_ref) {
511 if (p->p_prison->pr_linux != NULL)
512 FREE(p->p_prison->pr_linux, M_PRISON);
513 FREE(p->p_prison, M_PRISON);
514 }
515
516 /*
517 * Remove unused arguments
518 */
519 if (p->p_args && --p->p_args->ar_ref == 0)
520 FREE(p->p_args, M_PARGS);
521
522 /*
523 * Finally finished with old proc entry.
524 * Unlink it from its process group and free it.
525 */
526 leavepgrp(p);
527 LIST_REMOVE(p, p_list); /* off zombproc */
528 LIST_REMOVE(p, p_sibling);
529
530 if (--p->p_procsig->ps_refcnt == 0) {
531 if (p->p_sigacts != &p->p_addr->u_sigacts)
532 FREE(p->p_sigacts, M_SUBPROC);
533 FREE(p->p_procsig, M_SUBPROC);
534 p->p_procsig = NULL;
535 }
536
537 /*
538 * Give machine-dependent layer a chance
539 * to free anything that cpu_exit couldn't
540 * release while still running in process context.
541 */
542 vm_waitproc(p);
543 zfree(proc_zone, p);
544 nprocs--;
545 return (0);
546 }
547 if (p->p_stat == SSTOP && (p->p_flag & P_WAITED) == 0 &&
548 (p->p_flag & P_TRACED || uap->options & WUNTRACED)) {
549 p->p_flag |= P_WAITED;
550 q->p_retval[0] = p->p_pid;
551#ifdef COMPAT_43
552 if (compat) {
553 q->p_retval[1] = W_STOPCODE(p->p_xstat);
554 error = 0;
555 } else
556#endif
557 if (uap->status) {
558 status = W_STOPCODE(p->p_xstat);
559 error = copyout((caddr_t)&status,
560 (caddr_t)uap->status, sizeof(status));
561 } else
562 error = 0;
563 return (error);
564 }
565 }
566 if (nfound == 0)
567 return (ECHILD);
568 if (uap->options & WNOHANG) {
569 q->p_retval[0] = 0;
570 return (0);
571 }
572 if ((error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)))
573 return (error);
574 goto loop;
575}
576
577/*
578 * make process 'parent' the new parent of process 'child'.
579 */
580void
581proc_reparent(child, parent)
582 register struct proc *child;
583 register struct proc *parent;
584{
585
586 if (child->p_pptr == parent)
587 return;
588
589 LIST_REMOVE(child, p_sibling);
590 LIST_INSERT_HEAD(&parent->p_children, child, p_sibling);
591 child->p_pptr = parent;
592}
593
594/*
595 * The next two functions are to handle adding/deleting items on the
596 * exit callout list
597 *
598 * at_exit():
599 * Take the arguments given and put them onto the exit callout list,
600 * However first make sure that it's not already there.
601 * returns 0 on success.
602 */
603
604int
605at_exit(function)
606 exitlist_fn function;
607{
608 struct exitlist *ep;
609
610#ifdef INVARIANTS
611 /* Be noisy if the programmer has lost track of things */
612 if (rm_at_exit(function))
613 printf("WARNING: exit callout entry (%p) already present\n",
614 function);
615#endif
616 ep = malloc(sizeof(*ep), M_ATEXIT, M_NOWAIT);
617 if (ep == NULL)
618 return (ENOMEM);
619 ep->function = function;
620 TAILQ_INSERT_TAIL(&exit_list, ep, next);
621 return (0);
622}
623
624/*
625 * Scan the exit callout list for the given item and remove it.
626 * Returns the number of items removed (0 or 1)
627 */
628int
629rm_at_exit(function)
630 exitlist_fn function;
631{
632 struct exitlist *ep;
633
634 TAILQ_FOREACH(ep, &exit_list, next) {
635 if (ep->function == function) {
636 TAILQ_REMOVE(&exit_list, ep, next);
637 free(ep, M_ATEXIT);
638 return(1);
639 }
640 }
641 return (0);
642}
643
644void check_sigacts (void)
645{
646 struct proc *p = curproc;
647 struct sigacts *pss;
648 int s;
649
650 if (p->p_procsig->ps_refcnt == 1 &&
651 p->p_sigacts != &p->p_addr->u_sigacts) {
652 pss = p->p_sigacts;
653 s = splhigh();
654 p->p_addr->u_sigacts = *pss;
655 p->p_sigacts = &p->p_addr->u_sigacts;
656 splx(s);
657 FREE(pss, M_SUBPROC);
658 }
659}
660