xref: /openbsd-src/sys/kern/kern_proc.c (revision ae3cb403620ab940fbaabb3055fac045a63d56b7)
1 /*	$OpenBSD: kern_proc.c,v 1.79 2017/12/30 20:47:00 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 <ufs/ufs/quota.h>
43 #include <sys/uio.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/ioctl.h>
47 #include <sys/tty.h>
48 #include <sys/signalvar.h>
49 #include <sys/pool.h>
50 
51 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
52 LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
53 u_long uihash;		/* size of hash table - 1 */
54 
55 /*
56  * Other process lists
57  */
58 struct tidhashhead *tidhashtbl;
59 u_long tidhash;
60 struct pidhashhead *pidhashtbl;
61 u_long pidhash;
62 struct pgrphashhead *pgrphashtbl;
63 u_long pgrphash;
64 struct processlist allprocess;
65 struct processlist zombprocess;
66 struct proclist allproc;
67 
68 struct pool proc_pool;
69 struct pool process_pool;
70 struct pool rusage_pool;
71 struct pool ucred_pool;
72 struct pool pgrp_pool;
73 struct pool session_pool;
74 
75 static void orphanpg(struct pgrp *);
76 #ifdef DEBUG
77 void pgrpdump(void);
78 #endif
79 
80 /*
81  * Initialize global process hashing structures.
82  */
83 void
84 procinit(void)
85 {
86 	LIST_INIT(&allprocess);
87 	LIST_INIT(&zombprocess);
88 	LIST_INIT(&allproc);
89 
90 
91 	tidhashtbl = hashinit(maxthread / 4, M_PROC, M_NOWAIT, &tidhash);
92 	pidhashtbl = hashinit(maxprocess / 4, M_PROC, M_NOWAIT, &pidhash);
93 	pgrphashtbl = hashinit(maxprocess / 4, M_PROC, M_NOWAIT, &pgrphash);
94 	uihashtbl = hashinit(maxprocess / 16, M_PROC, M_NOWAIT, &uihash);
95 	if (!tidhashtbl || !pidhashtbl || !pgrphashtbl || !uihashtbl)
96 		panic("procinit: malloc");
97 
98 	pool_init(&proc_pool, sizeof(struct proc), 0, IPL_NONE,
99 	    PR_WAITOK, "procpl", NULL);
100 	pool_init(&process_pool, sizeof(struct process), 0, IPL_NONE,
101 	    PR_WAITOK, "processpl", NULL);
102 	pool_init(&rusage_pool, sizeof(struct rusage), 0, IPL_NONE,
103 	    PR_WAITOK, "zombiepl", NULL);
104 	pool_init(&ucred_pool, sizeof(struct ucred), 0, IPL_NONE,
105 	    PR_WAITOK, "ucredpl", NULL);
106 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, IPL_NONE,
107 	    PR_WAITOK, "pgrppl", NULL);
108 	pool_init(&session_pool, sizeof(struct session), 0, IPL_NONE,
109 	    PR_WAITOK, "sessionpl", NULL);
110 }
111 
112 struct uidinfo *
113 uid_find(uid_t uid)
114 {
115 	struct uidinfo *uip, *nuip;
116 	struct uihashhead *uipp;
117 
118 	uipp = UIHASH(uid);
119 	LIST_FOREACH(uip, uipp, ui_hash)
120 		if (uip->ui_uid == uid)
121 			break;
122 	if (uip)
123 		return (uip);
124 	nuip = malloc(sizeof(*nuip), M_PROC, M_WAITOK|M_ZERO);
125 	LIST_FOREACH(uip, uipp, ui_hash)
126 		if (uip->ui_uid == uid)
127 			break;
128 	if (uip) {
129 		free(nuip, M_PROC, sizeof(*nuip));
130 		return (uip);
131 	}
132 	nuip->ui_uid = uid;
133 	LIST_INSERT_HEAD(uipp, nuip, ui_hash);
134 
135 	return (nuip);
136 }
137 
138 /*
139  * Change the count associated with number of threads
140  * a given user is using.
141  */
142 int
143 chgproccnt(uid_t uid, int diff)
144 {
145 	struct uidinfo *uip;
146 
147 	uip = uid_find(uid);
148 	uip->ui_proccnt += diff;
149 	if (uip->ui_proccnt < 0)
150 		panic("chgproccnt: procs < 0");
151 	return (uip->ui_proccnt);
152 }
153 
154 /*
155  * Is pr an inferior of parent?
156  */
157 int
158 inferior(struct process *pr, struct process *parent)
159 {
160 
161 	for (; pr != parent; pr = pr->ps_pptr)
162 		if (pr->ps_pid == 0 || pr->ps_pid == 1)
163 			return (0);
164 	return (1);
165 }
166 
167 /*
168  * Locate a proc (thread) by number
169  */
170 struct proc *
171 tfind(pid_t tid)
172 {
173 	struct proc *p;
174 
175 	LIST_FOREACH(p, TIDHASH(tid), p_hash)
176 		if (p->p_tid == tid)
177 			return (p);
178 	return (NULL);
179 }
180 
181 /*
182  * Locate a process by number
183  */
184 struct process *
185 prfind(pid_t pid)
186 {
187 	struct process *pr;
188 
189 	LIST_FOREACH(pr, PIDHASH(pid), ps_hash)
190 		if (pr->ps_pid == pid)
191 			return (pr);
192 	return (NULL);
193 }
194 
195 /*
196  * Locate a process group by number
197  */
198 struct pgrp *
199 pgfind(pid_t pgid)
200 {
201 	struct pgrp *pgrp;
202 
203 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
204 		if (pgrp->pg_id == pgid)
205 			return (pgrp);
206 	return (NULL);
207 }
208 
209 /*
210  * Locate a zombie process
211  */
212 struct process *
213 zombiefind(pid_t pid)
214 {
215 	struct process *pr;
216 
217 	LIST_FOREACH(pr, &zombprocess, ps_list)
218 		if (pr->ps_pid == pid)
219 			return (pr);
220 	return (NULL);
221 }
222 
223 /*
224  * Move p to a new or existing process group (and session)
225  * Caller provides a pre-allocated pgrp and session that should
226  * be freed if they are not used.
227  * XXX need proctree lock
228  */
229 int
230 enterpgrp(struct process *pr, pid_t pgid, struct pgrp *newpgrp,
231     struct session *newsess)
232 {
233 	struct pgrp *pgrp = pgfind(pgid);
234 
235 #ifdef DIAGNOSTIC
236 	if (pgrp != NULL && newsess)	/* firewalls */
237 		panic("enterpgrp: setsid into non-empty pgrp");
238 	if (SESS_LEADER(pr))
239 		panic("enterpgrp: session leader attempted setpgrp");
240 #endif
241 	if (pgrp == NULL) {
242 		/*
243 		 * new process group
244 		 */
245 #ifdef DIAGNOSTIC
246 		if (pr->ps_pid != pgid)
247 			panic("enterpgrp: new pgrp and pid != pgid");
248 #endif
249 
250 		pgrp = newpgrp;
251 		if (newsess) {
252 			/*
253 			 * new session
254 			 */
255 			newsess->s_leader = pr;
256 			newsess->s_count = 1;
257 			newsess->s_ttyvp = NULL;
258 			newsess->s_ttyp = NULL;
259 			memcpy(newsess->s_login, pr->ps_session->s_login,
260 			    sizeof(newsess->s_login));
261 			atomic_clearbits_int(&pr->ps_flags, PS_CONTROLT);
262 			pgrp->pg_session = newsess;
263 #ifdef DIAGNOSTIC
264 			if (pr != curproc->p_p)
265 				panic("enterpgrp: mksession but not curproc");
266 #endif
267 		} else {
268 			pgrp->pg_session = pr->ps_session;
269 			pgrp->pg_session->s_count++;
270 		}
271 		pgrp->pg_id = pgid;
272 		LIST_INIT(&pgrp->pg_members);
273 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
274 		pgrp->pg_jobc = 0;
275 	} else if (pgrp == pr->ps_pgrp) {
276 		if (newsess)
277 			pool_put(&session_pool, newsess);
278 		pool_put(&pgrp_pool, newpgrp);
279 		return (0);
280 	} else {
281 		if (newsess)
282 			pool_put(&session_pool, newsess);
283 		pool_put(&pgrp_pool, newpgrp);
284 	}
285 
286 	/*
287 	 * Adjust eligibility of affected pgrps to participate in job control.
288 	 * Increment eligibility counts before decrementing, otherwise we
289 	 * could reach 0 spuriously during the first call.
290 	 */
291 	fixjobc(pr, pgrp, 1);
292 	fixjobc(pr, pr->ps_pgrp, 0);
293 
294 	LIST_REMOVE(pr, ps_pglist);
295 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
296 		pgdelete(pr->ps_pgrp);
297 	pr->ps_pgrp = pgrp;
298 	LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
299 	return (0);
300 }
301 
302 /*
303  * remove process from process group
304  */
305 void
306 leavepgrp(struct process *pr)
307 {
308 
309 	if (pr->ps_session->s_verauthppid == pr->ps_pid)
310 		zapverauth(pr->ps_session);
311 	LIST_REMOVE(pr, ps_pglist);
312 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
313 		pgdelete(pr->ps_pgrp);
314 	pr->ps_pgrp = 0;
315 }
316 
317 /*
318  * delete a process group
319  */
320 void
321 pgdelete(struct pgrp *pgrp)
322 {
323 
324 	if (pgrp->pg_session->s_ttyp != NULL &&
325 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
326 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
327 	LIST_REMOVE(pgrp, pg_hash);
328 	SESSRELE(pgrp->pg_session);
329 	pool_put(&pgrp_pool, pgrp);
330 }
331 
332 void
333 zapverauth(void *v)
334 {
335 	struct session *sess = v;
336 	sess->s_verauthuid = 0;
337 	sess->s_verauthppid = 0;
338 }
339 
340 /*
341  * Adjust pgrp jobc counters when specified process changes process group.
342  * We count the number of processes in each process group that "qualify"
343  * the group for terminal job control (those with a parent in a different
344  * process group of the same session).  If that count reaches zero, the
345  * process group becomes orphaned.  Check both the specified process'
346  * process group and that of its children.
347  * entering == 0 => pr is leaving specified group.
348  * entering == 1 => pr is entering specified group.
349  * XXX need proctree lock
350  */
351 void
352 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
353 {
354 	struct pgrp *hispgrp;
355 	struct session *mysession = pgrp->pg_session;
356 
357 	/*
358 	 * Check pr's parent to see whether pr qualifies its own process
359 	 * group; if so, adjust count for pr's process group.
360 	 */
361 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
362 	    hispgrp->pg_session == mysession) {
363 		if (entering)
364 			pgrp->pg_jobc++;
365 		else if (--pgrp->pg_jobc == 0)
366 			orphanpg(pgrp);
367 	}
368 
369 	/*
370 	 * Check this process' children to see whether they qualify
371 	 * their process groups; if so, adjust counts for children's
372 	 * process groups.
373 	 */
374 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
375 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
376 		    hispgrp->pg_session == mysession &&
377 		    (pr->ps_flags & PS_ZOMBIE) == 0) {
378 			if (entering)
379 				hispgrp->pg_jobc++;
380 			else if (--hispgrp->pg_jobc == 0)
381 				orphanpg(hispgrp);
382 		}
383 }
384 
385 /*
386  * A process group has become orphaned;
387  * if there are any stopped processes in the group,
388  * hang-up all process in that group.
389  */
390 static void
391 orphanpg(struct pgrp *pg)
392 {
393 	struct process *pr;
394 
395 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
396 		if (pr->ps_mainproc->p_stat == SSTOP) {
397 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
398 				prsignal(pr, SIGHUP);
399 				prsignal(pr, SIGCONT);
400 			}
401 			return;
402 		}
403 	}
404 }
405 
406 #ifdef DDB
407 void
408 proc_printit(struct proc *p, const char *modif,
409     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
410 {
411 	static const char *const pstat[] = {
412 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
413 	};
414 	char pstbuf[5];
415 	const char *pst = pstbuf;
416 
417 
418 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
419 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
420 	else
421 		pst = pstat[(int)p->p_stat - 1];
422 
423 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_p->ps_comm, p->p_tid, pst);
424 	(*pr)("    flags process=%b proc=%b\n",
425 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
426 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
427 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
428 	(*pr)("    forw=%p, list=%p,%p\n",
429 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
430 	(*pr)("    process=%p user=%p, vmspace=%p\n",
431 	    p->p_p, p->p_addr, p->p_vmspace);
432 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u\n",
433 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100);
434 	(*pr)("    user=%u, sys=%u, intr=%u\n",
435 	    p->p_uticks, p->p_sticks, p->p_iticks);
436 }
437 #include <machine/db_machdep.h>
438 
439 #include <ddb/db_output.h>
440 
441 void
442 db_kill_cmd(db_expr_t addr, int have_addr, db_expr_t count, char *modif)
443 {
444 	struct process *pr;
445 	struct sigaction sa;
446 	struct proc *p;
447 
448 	pr = prfind(addr);
449 	if (pr == NULL) {
450 		db_printf("%ld: No such process", addr);
451 		return;
452 	}
453 
454 	p = TAILQ_FIRST(&pr->ps_threads);
455 
456 	/* Send uncatchable SIGABRT for coredump */
457 	memset(&sa, 0, sizeof sa);
458 	sa.sa_handler = SIG_DFL;
459 	setsigvec(p, SIGABRT, &sa);
460 	psignal(p, SIGABRT);
461 }
462 
463 void
464 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
465 {
466 	char *mode;
467 	int skipzomb = 0;
468 	int has_kernel_lock = 0;
469 	struct proc *p;
470 	struct process *pr, *ppr;
471 
472 	if (modif[0] == 0)
473 		modif[0] = 'n';			/* default == normal mode */
474 
475 	mode = "mawno";
476 	while (*mode && *mode != modif[0])
477 		mode++;
478 	if (*mode == 0 || *mode == 'm') {
479 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
480 		db_printf("\t/a == show process address info\n");
481 		db_printf("\t/n == show normal process info [default]\n");
482 		db_printf("\t/w == show process pgrp/wait info\n");
483 		db_printf("\t/o == show normal info for non-idle SONPROC\n");
484 		return;
485 	}
486 
487 	pr = LIST_FIRST(&allprocess);
488 
489 	switch (*mode) {
490 
491 	case 'a':
492 		db_printf("    TID  %-9s  %18s  %18s  %18s\n",
493 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
494 		break;
495 	case 'n':
496 		db_printf("   PID  %6s  %5s  %5s  S  %10s  %-12s  %-15s\n",
497 		    "TID", "PPID", "UID", "FLAGS", "WAIT", "COMMAND");
498 		break;
499 	case 'w':
500 		db_printf("    TID  %-15s  %-5s  %18s  %s\n",
501 		    "COMMAND", "PGRP", "WAIT-CHANNEL", "WAIT-MSG");
502 		break;
503 	case 'o':
504 		skipzomb = 1;
505 		db_printf("    TID  %5s  %5s  %10s %10s  %3s  %-30s\n",
506 		    "PID", "UID", "PRFLAGS", "PFLAGS", "CPU", "COMMAND");
507 		break;
508 	}
509 
510 	while (pr != NULL) {
511 		ppr = pr->ps_pptr;
512 
513 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
514 #ifdef MULTIPROCESSOR
515 			if (__mp_lock_held(&kernel_lock, p->p_cpu))
516 				has_kernel_lock = 1;
517 			else
518 				has_kernel_lock = 0;
519 #endif
520 			if (p->p_stat) {
521 				if (*mode == 'o') {
522 					if (p->p_stat != SONPROC)
523 						continue;
524 					if (p->p_cpu != NULL && p->p_cpu->
525 					    ci_schedstate.spc_idleproc == p)
526 						continue;
527 				}
528 
529 				if (*mode == 'n') {
530 					db_printf("%c%5d  ", (p == curproc ?
531 					    '*' : ' '), pr->ps_pid);
532 				} else {
533 					db_printf("%c%6d  ", (p == curproc ?
534 					    '*' : ' '), p->p_tid);
535 				}
536 
537 				switch (*mode) {
538 
539 				case 'a':
540 					db_printf("%-9.9s  %18p  %18p  %18p\n",
541 					    pr->ps_comm, p, p->p_addr, p->p_vmspace);
542 					break;
543 
544 				case 'n':
545 					db_printf("%6d  %5d  %5d  %d  %#10x  "
546 					    "%-12.12s  %-15s\n",
547 					    p->p_tid, ppr ? ppr->ps_pid : -1,
548 					    pr->ps_ucred->cr_ruid, p->p_stat,
549 					    p->p_flag | pr->ps_flags,
550 					    (p->p_wchan && p->p_wmesg) ?
551 						p->p_wmesg : "", pr->ps_comm);
552 					break;
553 
554 				case 'w':
555 					db_printf("%-15s  %-5d  %18p  %s\n",
556 					    pr->ps_comm, (pr->ps_pgrp ?
557 						pr->ps_pgrp->pg_id : -1),
558 					    p->p_wchan,
559 					    (p->p_wchan && p->p_wmesg) ?
560 						p->p_wmesg : "");
561 					break;
562 
563 				case 'o':
564 					db_printf("%5d  %5d  %#10x %#10x  %3d"
565 					    "%c %-31s\n",
566 					    pr->ps_pid, pr->ps_ucred->cr_ruid,
567 					    pr->ps_flags, p->p_flag,
568 					    CPU_INFO_UNIT(p->p_cpu),
569 					    has_kernel_lock ? 'K' : ' ',
570 					    pr->ps_comm);
571 					break;
572 
573 				}
574 			}
575 		}
576 		pr = LIST_NEXT(pr, ps_list);
577 		if (pr == NULL && skipzomb == 0) {
578 			skipzomb = 1;
579 			pr = LIST_FIRST(&zombprocess);
580 		}
581 	}
582 }
583 #endif
584 
585 #ifdef DEBUG
586 void
587 pgrpdump(void)
588 {
589 	struct pgrp *pgrp;
590 	struct process *pr;
591 	int i;
592 
593 	for (i = 0; i <= pgrphash; i++) {
594 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
595 			printf("\tindx %d\n", i);
596 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
597 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
598 				    pgrp, pgrp->pg_id, pgrp->pg_session,
599 				    pgrp->pg_session->s_count,
600 				    LIST_FIRST(&pgrp->pg_members));
601 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
602 					printf("\t\tpid %d addr %p pgrp %p\n",
603 					    pr->ps_pid, pr, pr->ps_pgrp);
604 				}
605 			}
606 		}
607 	}
608 }
609 #endif /* DEBUG */
610