xref: /openbsd/sys/kern/kern_proc.c (revision 6f40fd34)
1 /*	$OpenBSD: kern_proc.c,v 1.76 2017/02/04 07:42:52 guenther Exp $	*/
2 /*	$NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1989, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)kern_proc.c	8.4 (Berkeley) 1/4/94
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/proc.h>
39 #include <sys/buf.h>
40 #include <sys/acct.h>
41 #include <sys/wait.h>
42 #include <sys/file.h>
43 #include <ufs/ufs/quota.h>
44 #include <sys/uio.h>
45 #include <sys/malloc.h>
46 #include <sys/mbuf.h>
47 #include <sys/ioctl.h>
48 #include <sys/tty.h>
49 #include <sys/signalvar.h>
50 #include <sys/pool.h>
51 
52 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
53 LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
54 u_long uihash;		/* size of hash table - 1 */
55 
56 /*
57  * Other process lists
58  */
59 struct tidhashhead *tidhashtbl;
60 u_long tidhash;
61 struct pidhashhead *pidhashtbl;
62 u_long pidhash;
63 struct pgrphashhead *pgrphashtbl;
64 u_long pgrphash;
65 struct processlist allprocess;
66 struct processlist zombprocess;
67 struct proclist allproc;
68 
69 struct pool proc_pool;
70 struct pool process_pool;
71 struct pool rusage_pool;
72 struct pool ucred_pool;
73 struct pool pgrp_pool;
74 struct pool session_pool;
75 
76 static void orphanpg(struct pgrp *);
77 #ifdef DEBUG
78 void pgrpdump(void);
79 #endif
80 
81 /*
82  * Initialize global process hashing structures.
83  */
84 void
85 procinit(void)
86 {
87 	LIST_INIT(&allprocess);
88 	LIST_INIT(&zombprocess);
89 	LIST_INIT(&allproc);
90 
91 
92 	tidhashtbl = hashinit(maxthread / 4, M_PROC, M_NOWAIT, &tidhash);
93 	pidhashtbl = hashinit(maxprocess / 4, M_PROC, M_NOWAIT, &pidhash);
94 	pgrphashtbl = hashinit(maxprocess / 4, M_PROC, M_NOWAIT, &pgrphash);
95 	uihashtbl = hashinit(maxprocess / 16, M_PROC, M_NOWAIT, &uihash);
96 	if (!tidhashtbl || !pidhashtbl || !pgrphashtbl || !uihashtbl)
97 		panic("procinit: malloc");
98 
99 	pool_init(&proc_pool, sizeof(struct proc), 0, IPL_NONE,
100 	    PR_WAITOK, "procpl", NULL);
101 	pool_init(&process_pool, sizeof(struct process), 0, IPL_NONE,
102 	    PR_WAITOK, "processpl", NULL);
103 	pool_init(&rusage_pool, sizeof(struct rusage), 0, IPL_NONE,
104 	    PR_WAITOK, "zombiepl", NULL);
105 	pool_init(&ucred_pool, sizeof(struct ucred), 0, IPL_NONE,
106 	    PR_WAITOK, "ucredpl", NULL);
107 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, IPL_NONE,
108 	    PR_WAITOK, "pgrppl", NULL);
109 	pool_init(&session_pool, sizeof(struct session), 0, IPL_NONE,
110 	    PR_WAITOK, "sessionpl", NULL);
111 }
112 
113 struct uidinfo *
114 uid_find(uid_t uid)
115 {
116 	struct uidinfo *uip, *nuip;
117 	struct uihashhead *uipp;
118 
119 	uipp = UIHASH(uid);
120 	LIST_FOREACH(uip, uipp, ui_hash)
121 		if (uip->ui_uid == uid)
122 			break;
123 	if (uip)
124 		return (uip);
125 	nuip = malloc(sizeof(*nuip), M_PROC, M_WAITOK|M_ZERO);
126 	LIST_FOREACH(uip, uipp, ui_hash)
127 		if (uip->ui_uid == uid)
128 			break;
129 	if (uip) {
130 		free(nuip, M_PROC, sizeof(*nuip));
131 		return (uip);
132 	}
133 	nuip->ui_uid = uid;
134 	LIST_INSERT_HEAD(uipp, nuip, ui_hash);
135 
136 	return (nuip);
137 }
138 
139 /*
140  * Change the count associated with number of threads
141  * a given user is using.
142  */
143 int
144 chgproccnt(uid_t uid, int diff)
145 {
146 	struct uidinfo *uip;
147 
148 	uip = uid_find(uid);
149 	uip->ui_proccnt += diff;
150 	if (uip->ui_proccnt < 0)
151 		panic("chgproccnt: procs < 0");
152 	return (uip->ui_proccnt);
153 }
154 
155 /*
156  * Is pr an inferior of parent?
157  */
158 int
159 inferior(struct process *pr, struct process *parent)
160 {
161 
162 	for (; pr != parent; pr = pr->ps_pptr)
163 		if (pr->ps_pid == 0 || pr->ps_pid == 1)
164 			return (0);
165 	return (1);
166 }
167 
168 /*
169  * Locate a proc (thread) by number
170  */
171 struct proc *
172 tfind(pid_t tid)
173 {
174 	struct proc *p;
175 
176 	LIST_FOREACH(p, TIDHASH(tid), p_hash)
177 		if (p->p_tid == tid)
178 			return (p);
179 	return (NULL);
180 }
181 
182 /*
183  * Locate a process by number
184  */
185 struct process *
186 prfind(pid_t pid)
187 {
188 	struct process *pr;
189 
190 	LIST_FOREACH(pr, PIDHASH(pid), ps_hash)
191 		if (pr->ps_pid == pid)
192 			return (pr);
193 	return (NULL);
194 }
195 
196 /*
197  * Locate a process group by number
198  */
199 struct pgrp *
200 pgfind(pid_t pgid)
201 {
202 	struct pgrp *pgrp;
203 
204 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
205 		if (pgrp->pg_id == pgid)
206 			return (pgrp);
207 	return (NULL);
208 }
209 
210 /*
211  * Locate a zombie process
212  */
213 struct process *
214 zombiefind(pid_t pid)
215 {
216 	struct process *pr;
217 
218 	LIST_FOREACH(pr, &zombprocess, ps_list)
219 		if (pr->ps_pid == pid)
220 			return (pr);
221 	return (NULL);
222 }
223 
224 /*
225  * Move p to a new or existing process group (and session)
226  * Caller provides a pre-allocated pgrp and session that should
227  * be freed if they are not used.
228  * XXX need proctree lock
229  */
230 int
231 enterpgrp(struct process *pr, pid_t pgid, struct pgrp *newpgrp,
232     struct session *newsess)
233 {
234 	struct pgrp *pgrp = pgfind(pgid);
235 
236 #ifdef DIAGNOSTIC
237 	if (pgrp != NULL && newsess)	/* firewalls */
238 		panic("enterpgrp: setsid into non-empty pgrp");
239 	if (SESS_LEADER(pr))
240 		panic("enterpgrp: session leader attempted setpgrp");
241 #endif
242 	if (pgrp == NULL) {
243 		/*
244 		 * new process group
245 		 */
246 #ifdef DIAGNOSTIC
247 		if (pr->ps_pid != pgid)
248 			panic("enterpgrp: new pgrp and pid != pgid");
249 #endif
250 
251 		pgrp = newpgrp;
252 		if (newsess) {
253 			/*
254 			 * new session
255 			 */
256 			newsess->s_leader = pr;
257 			newsess->s_count = 1;
258 			newsess->s_ttyvp = NULL;
259 			newsess->s_ttyp = NULL;
260 			memcpy(newsess->s_login, pr->ps_session->s_login,
261 			    sizeof(newsess->s_login));
262 			atomic_clearbits_int(&pr->ps_flags, PS_CONTROLT);
263 			pgrp->pg_session = newsess;
264 #ifdef DIAGNOSTIC
265 			if (pr != curproc->p_p)
266 				panic("enterpgrp: mksession but not curproc");
267 #endif
268 		} else {
269 			pgrp->pg_session = pr->ps_session;
270 			pgrp->pg_session->s_count++;
271 		}
272 		pgrp->pg_id = pgid;
273 		LIST_INIT(&pgrp->pg_members);
274 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
275 		pgrp->pg_jobc = 0;
276 	} else if (pgrp == pr->ps_pgrp) {
277 		if (newsess)
278 			pool_put(&session_pool, newsess);
279 		pool_put(&pgrp_pool, newpgrp);
280 		return (0);
281 	} else {
282 		if (newsess)
283 			pool_put(&session_pool, newsess);
284 		pool_put(&pgrp_pool, newpgrp);
285 	}
286 
287 	/*
288 	 * Adjust eligibility of affected pgrps to participate in job control.
289 	 * Increment eligibility counts before decrementing, otherwise we
290 	 * could reach 0 spuriously during the first call.
291 	 */
292 	fixjobc(pr, pgrp, 1);
293 	fixjobc(pr, pr->ps_pgrp, 0);
294 
295 	LIST_REMOVE(pr, ps_pglist);
296 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
297 		pgdelete(pr->ps_pgrp);
298 	pr->ps_pgrp = pgrp;
299 	LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
300 	return (0);
301 }
302 
303 /*
304  * remove process from process group
305  */
306 void
307 leavepgrp(struct process *pr)
308 {
309 
310 	if (pr->ps_session->s_verauthppid == pr->ps_pid)
311 		zapverauth(pr->ps_session);
312 	LIST_REMOVE(pr, ps_pglist);
313 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
314 		pgdelete(pr->ps_pgrp);
315 	pr->ps_pgrp = 0;
316 }
317 
318 /*
319  * delete a process group
320  */
321 void
322 pgdelete(struct pgrp *pgrp)
323 {
324 
325 	if (pgrp->pg_session->s_ttyp != NULL &&
326 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
327 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
328 	LIST_REMOVE(pgrp, pg_hash);
329 	SESSRELE(pgrp->pg_session);
330 	pool_put(&pgrp_pool, pgrp);
331 }
332 
333 void
334 zapverauth(void *v)
335 {
336 	struct session *sess = v;
337 	sess->s_verauthuid = 0;
338 	sess->s_verauthppid = 0;
339 }
340 
341 /*
342  * Adjust pgrp jobc counters when specified process changes process group.
343  * We count the number of processes in each process group that "qualify"
344  * the group for terminal job control (those with a parent in a different
345  * process group of the same session).  If that count reaches zero, the
346  * process group becomes orphaned.  Check both the specified process'
347  * process group and that of its children.
348  * entering == 0 => pr is leaving specified group.
349  * entering == 1 => pr is entering specified group.
350  * XXX need proctree lock
351  */
352 void
353 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
354 {
355 	struct pgrp *hispgrp;
356 	struct session *mysession = pgrp->pg_session;
357 
358 	/*
359 	 * Check pr's parent to see whether pr qualifies its own process
360 	 * group; if so, adjust count for pr's process group.
361 	 */
362 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
363 	    hispgrp->pg_session == mysession) {
364 		if (entering)
365 			pgrp->pg_jobc++;
366 		else if (--pgrp->pg_jobc == 0)
367 			orphanpg(pgrp);
368 	}
369 
370 	/*
371 	 * Check this process' children to see whether they qualify
372 	 * their process groups; if so, adjust counts for children's
373 	 * process groups.
374 	 */
375 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
376 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
377 		    hispgrp->pg_session == mysession &&
378 		    (pr->ps_flags & PS_ZOMBIE) == 0) {
379 			if (entering)
380 				hispgrp->pg_jobc++;
381 			else if (--hispgrp->pg_jobc == 0)
382 				orphanpg(hispgrp);
383 		}
384 }
385 
386 /*
387  * A process group has become orphaned;
388  * if there are any stopped processes in the group,
389  * hang-up all process in that group.
390  */
391 static void
392 orphanpg(struct pgrp *pg)
393 {
394 	struct process *pr;
395 
396 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
397 		if (pr->ps_mainproc->p_stat == SSTOP) {
398 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
399 				prsignal(pr, SIGHUP);
400 				prsignal(pr, SIGCONT);
401 			}
402 			return;
403 		}
404 	}
405 }
406 
407 #ifdef DDB
408 void
409 proc_printit(struct proc *p, const char *modif,
410     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
411 {
412 	static const char *const pstat[] = {
413 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
414 	};
415 	char pstbuf[5];
416 	const char *pst = pstbuf;
417 
418 
419 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
420 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
421 	else
422 		pst = pstat[(int)p->p_stat - 1];
423 
424 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_p->ps_comm, p->p_tid, pst);
425 	(*pr)("    flags process=%b proc=%b\n",
426 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
427 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
428 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
429 	(*pr)("    forw=%p, list=%p,%p\n",
430 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
431 	(*pr)("    process=%p user=%p, vmspace=%p\n",
432 	    p->p_p, p->p_addr, p->p_vmspace);
433 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u\n",
434 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100);
435 	(*pr)("    user=%u, sys=%u, intr=%u\n",
436 	    p->p_uticks, p->p_sticks, p->p_iticks);
437 }
438 #include <machine/db_machdep.h>
439 
440 #include <ddb/db_output.h>
441 
442 void
443 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
444 {
445 	char *mode;
446 	int skipzomb = 0;
447 	struct proc *p;
448 	struct process *pr, *ppr;
449 
450 	if (modif[0] == 0)
451 		modif[0] = 'n';			/* default == normal mode */
452 
453 	mode = "mawno";
454 	while (*mode && *mode != modif[0])
455 		mode++;
456 	if (*mode == 0 || *mode == 'm') {
457 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
458 		db_printf("\t/a == show process address info\n");
459 		db_printf("\t/n == show normal process info [default]\n");
460 		db_printf("\t/w == show process pgrp/wait info\n");
461 		db_printf("\t/o == show normal info for non-idle SONPROC\n");
462 		return;
463 	}
464 
465 	pr = LIST_FIRST(&allprocess);
466 
467 	switch (*mode) {
468 
469 	case 'a':
470 		db_printf("    TID  %-9s  %18s  %18s  %18s\n",
471 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
472 		break;
473 	case 'n':
474 		db_printf("   PID  %6s  %5s  %5s  S  %10s  %-12s  %-15s\n",
475 		    "TID", "PPID", "UID", "FLAGS", "WAIT", "COMMAND");
476 		break;
477 	case 'w':
478 		db_printf("    TID  %-15s  %-5s  %18s  %s\n",
479 		    "COMMAND", "PGRP", "WAIT-CHANNEL", "WAIT-MSG");
480 		break;
481 	case 'o':
482 		skipzomb = 1;
483 		db_printf("    TID  %5s  %5s  %10s %10s  %3s  %-30s\n",
484 		    "PID", "UID", "PRFLAGS", "PFLAGS", "CPU", "COMMAND");
485 		break;
486 	}
487 
488 	while (pr != NULL) {
489 		ppr = pr->ps_pptr;
490 
491 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
492 			if (p->p_stat) {
493 				if (*mode == 'o') {
494 					if (p->p_stat != SONPROC)
495 						continue;
496 					if (p->p_cpu != NULL && p->p_cpu->
497 					    ci_schedstate.spc_idleproc == p)
498 						continue;
499 				}
500 
501 				if (*mode == 'n') {
502 					db_printf("%c%5d  ", (p == curproc ?
503 					    '*' : ' '), pr->ps_pid);
504 				} else {
505 					db_printf("%c%6d  ", (p == curproc ?
506 					    '*' : ' '), p->p_tid);
507 				}
508 
509 				switch (*mode) {
510 
511 				case 'a':
512 					db_printf("%-9.9s  %18p  %18p  %18p\n",
513 					    pr->ps_comm, p, p->p_addr, p->p_vmspace);
514 					break;
515 
516 				case 'n':
517 					db_printf("%6d  %5d  %5d  %d  %#10x  "
518 					    "%-12.12s  %-15s\n",
519 					    p->p_tid, ppr ? ppr->ps_pid : -1,
520 					    pr->ps_ucred->cr_ruid, p->p_stat,
521 					    p->p_flag | pr->ps_flags,
522 					    (p->p_wchan && p->p_wmesg) ?
523 						p->p_wmesg : "", pr->ps_comm);
524 					break;
525 
526 				case 'w':
527 					db_printf("%-15s  %-5d  %18p  %s\n",
528 					    pr->ps_comm, (pr->ps_pgrp ?
529 						pr->ps_pgrp->pg_id : -1),
530 					    p->p_wchan,
531 					    (p->p_wchan && p->p_wmesg) ?
532 						p->p_wmesg : "");
533 					break;
534 
535 				case 'o':
536 					db_printf("%5d  %5d  %#10x %#10x  %3d"
537 					    "  %-31s\n",
538 					    pr->ps_pid, pr->ps_ucred->cr_ruid,
539 					    pr->ps_flags, p->p_flag,
540 					    CPU_INFO_UNIT(p->p_cpu),
541 					    pr->ps_comm);
542 					break;
543 
544 				}
545 			}
546 		}
547 		pr = LIST_NEXT(pr, ps_list);
548 		if (pr == NULL && skipzomb == 0) {
549 			skipzomb = 1;
550 			pr = LIST_FIRST(&zombprocess);
551 		}
552 	}
553 }
554 #endif
555 
556 #ifdef DEBUG
557 void
558 pgrpdump(void)
559 {
560 	struct pgrp *pgrp;
561 	struct process *pr;
562 	int i;
563 
564 	for (i = 0; i <= pgrphash; i++) {
565 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
566 			printf("\tindx %d\n", i);
567 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
568 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
569 				    pgrp, pgrp->pg_id, pgrp->pg_session,
570 				    pgrp->pg_session->s_count,
571 				    LIST_FIRST(&pgrp->pg_members));
572 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
573 					printf("\t\tpid %d addr %p pgrp %p\n",
574 					    pr->ps_pid, pr, pr->ps_pgrp);
575 				}
576 			}
577 		}
578 	}
579 }
580 #endif /* DEBUG */
581