xref: /openbsd/sys/kern/kern_proc.c (revision 998de4a5)
1 /*	$OpenBSD: kern_proc.c,v 1.68 2016/08/25 00:00:02 dlg 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 pidhashhead *pidhashtbl;
60 u_long pidhash;
61 struct pgrphashhead *pgrphashtbl;
62 u_long pgrphash;
63 struct processlist allprocess;
64 struct processlist zombprocess;
65 struct proclist allproc;
66 
67 struct pool proc_pool;
68 struct pool process_pool;
69 struct pool rusage_pool;
70 struct pool ucred_pool;
71 struct pool pgrp_pool;
72 struct pool session_pool;
73 
74 static void orphanpg(struct pgrp *);
75 #ifdef DEBUG
76 void pgrpdump(void);
77 #endif
78 
79 /*
80  * Initialize global process hashing structures.
81  */
82 void
83 procinit(void)
84 {
85 	LIST_INIT(&allprocess);
86 	LIST_INIT(&zombprocess);
87 	LIST_INIT(&allproc);
88 
89 
90 	pidhashtbl = hashinit(maxthread / 4, M_PROC, M_NOWAIT, &pidhash);
91 	pgrphashtbl = hashinit(maxprocess / 4, M_PROC, M_NOWAIT, &pgrphash);
92 	uihashtbl = hashinit(maxprocess / 16, M_PROC, M_NOWAIT, &uihash);
93 	if (!pidhashtbl || !pgrphashtbl || !uihashtbl)
94 		panic("procinit: malloc");
95 
96 	pool_init(&proc_pool, sizeof(struct proc), 0, 0, PR_WAITOK,
97 	    "procpl", NULL);
98 	pool_setipl(&proc_pool, IPL_NONE);
99 	pool_init(&process_pool, sizeof(struct process), 0, 0, PR_WAITOK,
100 	    "processpl", NULL);
101 	pool_setipl(&process_pool, IPL_NONE);
102 	pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, PR_WAITOK,
103 	    "zombiepl", NULL);
104 	pool_setipl(&rusage_pool, IPL_NONE);
105 	pool_init(&ucred_pool, sizeof(struct ucred), 0, 0, PR_WAITOK,
106 	    "ucredpl", NULL);
107 	pool_setipl(&ucred_pool, IPL_NONE);
108 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, PR_WAITOK,
109 	    "pgrppl", NULL);
110 	pool_setipl(&pgrp_pool, IPL_NONE);
111 	pool_init(&session_pool, sizeof(struct session), 0, 0, PR_WAITOK,
112 	    "sessionpl", NULL);
113 	pool_setipl(&session_pool, IPL_NONE);
114 }
115 
116 struct uidinfo *
117 uid_find(uid_t uid)
118 {
119 	struct uidinfo *uip, *nuip;
120 	struct uihashhead *uipp;
121 
122 	uipp = UIHASH(uid);
123 	LIST_FOREACH(uip, uipp, ui_hash)
124 		if (uip->ui_uid == uid)
125 			break;
126 	if (uip)
127 		return (uip);
128 	nuip = malloc(sizeof(*nuip), M_PROC, M_WAITOK|M_ZERO);
129 	LIST_FOREACH(uip, uipp, ui_hash)
130 		if (uip->ui_uid == uid)
131 			break;
132 	if (uip) {
133 		free(nuip, M_PROC, sizeof(*nuip));
134 		return (uip);
135 	}
136 	nuip->ui_uid = uid;
137 	LIST_INSERT_HEAD(uipp, nuip, ui_hash);
138 
139 	return (nuip);
140 }
141 
142 /*
143  * Change the count associated with number of threads
144  * a given user is using.
145  */
146 int
147 chgproccnt(uid_t uid, int diff)
148 {
149 	struct uidinfo *uip;
150 
151 	uip = uid_find(uid);
152 	uip->ui_proccnt += diff;
153 	if (uip->ui_proccnt < 0)
154 		panic("chgproccnt: procs < 0");
155 	return (uip->ui_proccnt);
156 }
157 
158 /*
159  * Is pr an inferior of parent?
160  */
161 int
162 inferior(struct process *pr, struct process *parent)
163 {
164 
165 	for (; pr != parent; pr = pr->ps_pptr)
166 		if (pr->ps_pid == 0 || pr->ps_pid == 1)
167 			return (0);
168 	return (1);
169 }
170 
171 /*
172  * Locate a proc (thread) by number
173  */
174 struct proc *
175 pfind(pid_t pid)
176 {
177 	struct proc *p;
178 
179 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
180 		if (p->p_pid == pid)
181 			return (p);
182 	return (NULL);
183 }
184 
185 /*
186  * Locate a process by number
187  */
188 struct process *
189 prfind(pid_t pid)
190 {
191 	struct proc *p;
192 
193 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
194 		if (p->p_pid == pid)
195 			return (p->p_flag & P_THREAD ? NULL : p->p_p);
196 	return (NULL);
197 }
198 
199 /*
200  * Locate a process group by number
201  */
202 struct pgrp *
203 pgfind(pid_t pgid)
204 {
205 	struct pgrp *pgrp;
206 
207 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
208 		if (pgrp->pg_id == pgid)
209 			return (pgrp);
210 	return (NULL);
211 }
212 
213 /*
214  * Locate a zombie process
215  */
216 struct process *
217 zombiefind(pid_t pid)
218 {
219 	struct process *pr;
220 
221 	LIST_FOREACH(pr, &zombprocess, ps_list)
222 		if (pr->ps_mainproc->p_pid == pid)
223 			return (pr);
224 	return (NULL);
225 }
226 
227 /*
228  * Move p to a new or existing process group (and session)
229  * Caller provides a pre-allocated pgrp and session that should
230  * be freed if they are not used.
231  * XXX need proctree lock
232  */
233 int
234 enterpgrp(struct process *pr, pid_t pgid, struct pgrp *newpgrp,
235     struct session *newsess)
236 {
237 	struct pgrp *pgrp = pgfind(pgid);
238 
239 #ifdef DIAGNOSTIC
240 	if (pgrp != NULL && newsess)	/* firewalls */
241 		panic("enterpgrp: setsid into non-empty pgrp");
242 	if (SESS_LEADER(pr))
243 		panic("enterpgrp: session leader attempted setpgrp");
244 #endif
245 	if (pgrp == NULL) {
246 		/*
247 		 * new process group
248 		 */
249 #ifdef DIAGNOSTIC
250 		if (pr->ps_pid != pgid)
251 			panic("enterpgrp: new pgrp and pid != pgid");
252 #endif
253 
254 		pgrp = newpgrp;
255 		if (newsess) {
256 			/*
257 			 * new session
258 			 */
259 			newsess->s_leader = pr;
260 			newsess->s_count = 1;
261 			newsess->s_ttyvp = NULL;
262 			newsess->s_ttyp = NULL;
263 			memcpy(newsess->s_login, pr->ps_session->s_login,
264 			    sizeof(newsess->s_login));
265 			atomic_clearbits_int(&pr->ps_flags, PS_CONTROLT);
266 			pgrp->pg_session = newsess;
267 #ifdef DIAGNOSTIC
268 			if (pr != curproc->p_p)
269 				panic("enterpgrp: mksession but not curproc");
270 #endif
271 		} else {
272 			pgrp->pg_session = pr->ps_session;
273 			pgrp->pg_session->s_count++;
274 		}
275 		pgrp->pg_id = pgid;
276 		LIST_INIT(&pgrp->pg_members);
277 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
278 		pgrp->pg_jobc = 0;
279 	} else if (pgrp == pr->ps_pgrp) {
280 		if (newsess)
281 			pool_put(&session_pool, newsess);
282 		pool_put(&pgrp_pool, newpgrp);
283 		return (0);
284 	} else {
285 		if (newsess)
286 			pool_put(&session_pool, newsess);
287 		pool_put(&pgrp_pool, newpgrp);
288 	}
289 
290 	/*
291 	 * Adjust eligibility of affected pgrps to participate in job control.
292 	 * Increment eligibility counts before decrementing, otherwise we
293 	 * could reach 0 spuriously during the first call.
294 	 */
295 	fixjobc(pr, pgrp, 1);
296 	fixjobc(pr, pr->ps_pgrp, 0);
297 
298 	LIST_REMOVE(pr, ps_pglist);
299 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
300 		pgdelete(pr->ps_pgrp);
301 	pr->ps_pgrp = pgrp;
302 	LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
303 	return (0);
304 }
305 
306 /*
307  * remove process from process group
308  */
309 void
310 leavepgrp(struct process *pr)
311 {
312 
313 	LIST_REMOVE(pr, ps_pglist);
314 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
315 		pgdelete(pr->ps_pgrp);
316 	pr->ps_pgrp = 0;
317 }
318 
319 /*
320  * delete a process group
321  */
322 void
323 pgdelete(struct pgrp *pgrp)
324 {
325 
326 	if (pgrp->pg_session->s_ttyp != NULL &&
327 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
328 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
329 	LIST_REMOVE(pgrp, pg_hash);
330 	SESSRELE(pgrp->pg_session);
331 	pool_put(&pgrp_pool, pgrp);
332 }
333 
334 /*
335  * Adjust pgrp jobc counters when specified process changes process group.
336  * We count the number of processes in each process group that "qualify"
337  * the group for terminal job control (those with a parent in a different
338  * process group of the same session).  If that count reaches zero, the
339  * process group becomes orphaned.  Check both the specified process'
340  * process group and that of its children.
341  * entering == 0 => pr is leaving specified group.
342  * entering == 1 => pr is entering specified group.
343  * XXX need proctree lock
344  */
345 void
346 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
347 {
348 	struct pgrp *hispgrp;
349 	struct session *mysession = pgrp->pg_session;
350 
351 	/*
352 	 * Check pr's parent to see whether pr qualifies its own process
353 	 * group; if so, adjust count for pr's process group.
354 	 */
355 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
356 	    hispgrp->pg_session == mysession) {
357 		if (entering)
358 			pgrp->pg_jobc++;
359 		else if (--pgrp->pg_jobc == 0)
360 			orphanpg(pgrp);
361 	}
362 
363 	/*
364 	 * Check this process' children to see whether they qualify
365 	 * their process groups; if so, adjust counts for children's
366 	 * process groups.
367 	 */
368 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
369 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
370 		    hispgrp->pg_session == mysession &&
371 		    (pr->ps_flags & PS_ZOMBIE) == 0) {
372 			if (entering)
373 				hispgrp->pg_jobc++;
374 			else if (--hispgrp->pg_jobc == 0)
375 				orphanpg(hispgrp);
376 		}
377 }
378 
379 /*
380  * A process group has become orphaned;
381  * if there are any stopped processes in the group,
382  * hang-up all process in that group.
383  */
384 static void
385 orphanpg(struct pgrp *pg)
386 {
387 	struct process *pr;
388 
389 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
390 		if (pr->ps_mainproc->p_stat == SSTOP) {
391 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
392 				prsignal(pr, SIGHUP);
393 				prsignal(pr, SIGCONT);
394 			}
395 			return;
396 		}
397 	}
398 }
399 
400 #ifdef DDB
401 void
402 proc_printit(struct proc *p, const char *modif,
403     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
404 {
405 	static const char *const pstat[] = {
406 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
407 	};
408 	char pstbuf[5];
409 	const char *pst = pstbuf;
410 
411 
412 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
413 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
414 	else
415 		pst = pstat[(int)p->p_stat - 1];
416 
417 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_comm, p->p_pid, pst);
418 	(*pr)("    flags process=%b proc=%b\n",
419 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
420 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
421 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
422 	(*pr)("    forw=%p, list=%p,%p\n",
423 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
424 	(*pr)("    process=%p user=%p, vmspace=%p\n",
425 	    p->p_p, p->p_addr, p->p_vmspace);
426 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u\n",
427 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100);
428 	(*pr)("    user=%u, sys=%u, intr=%u\n",
429 	    p->p_uticks, p->p_sticks, p->p_iticks);
430 }
431 #include <machine/db_machdep.h>
432 
433 #include <ddb/db_output.h>
434 
435 void
436 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
437 {
438 	char *mode;
439 	int skipzomb = 0;
440 	struct proc *p;
441 	struct process *pr, *ppr;
442 
443 	if (modif[0] == 0)
444 		modif[0] = 'n';			/* default == normal mode */
445 
446 	mode = "mawno";
447 	while (*mode && *mode != modif[0])
448 		mode++;
449 	if (*mode == 0 || *mode == 'm') {
450 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
451 		db_printf("\t/a == show process address info\n");
452 		db_printf("\t/n == show normal process info [default]\n");
453 		db_printf("\t/w == show process wait/emul info\n");
454 		db_printf("\t/o == show normal info for non-idle SONPROC\n");
455 		return;
456 	}
457 
458 	pr = LIST_FIRST(&allprocess);
459 
460 	switch (*mode) {
461 
462 	case 'a':
463 		db_printf("   TID  %-10s  %18s  %18s  %18s\n",
464 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
465 		break;
466 	case 'n':
467 		db_printf("   TID  %5s  %5s  %5s  S  %10s  %-12s  %-16s\n",
468 		    "PPID", "PGRP", "UID", "FLAGS", "WAIT", "COMMAND");
469 		break;
470 	case 'w':
471 		db_printf("   TID  %-16s  %-8s  %18s  %s\n",
472 		    "COMMAND", "EMUL", "WAIT-CHANNEL", "WAIT-MSG");
473 		break;
474 	case 'o':
475 		skipzomb = 1;
476 		db_printf("   TID  %5s  %5s  %10s %10s  %3s  %-31s\n",
477 		    "PID", "UID", "PRFLAGS", "PFLAGS", "CPU", "COMMAND");
478 		break;
479 	}
480 
481 	while (pr != NULL) {
482 		ppr = pr->ps_pptr;
483 
484 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
485 			if (p->p_stat) {
486 				if (*mode == 'o') {
487 					if (p->p_stat != SONPROC)
488 						continue;
489 					if (p->p_cpu != NULL && p->p_cpu->
490 					    ci_schedstate.spc_idleproc == p)
491 						continue;
492 				}
493 				db_printf("%c%5d  ", p == curproc ? '*' : ' ',
494 					p->p_pid);
495 
496 				switch (*mode) {
497 
498 				case 'a':
499 					db_printf("%-10.10s  %18p  %18p  %18p\n",
500 					    p->p_comm, p, p->p_addr, p->p_vmspace);
501 					break;
502 
503 				case 'n':
504 					db_printf("%5d  %5d  %5d  %d  %#10x  "
505 					    "%-12.12s  %-16s\n",
506 					    ppr ? ppr->ps_pid : -1,
507 					    pr->ps_pgrp ? pr->ps_pgrp->pg_id : -1,
508 					    pr->ps_ucred->cr_ruid, p->p_stat,
509 					    p->p_flag | pr->ps_flags,
510 					    (p->p_wchan && p->p_wmesg) ?
511 						p->p_wmesg : "", p->p_comm);
512 					break;
513 
514 				case 'w':
515 					db_printf("%-16s  %-8s  %18p  %s\n", p->p_comm,
516 					    pr->ps_emul->e_name, p->p_wchan,
517 					    (p->p_wchan && p->p_wmesg) ?
518 						p->p_wmesg : "");
519 					break;
520 
521 				case 'o':
522 					db_printf("%5d  %5d  %#10x %#10x  %3d"
523 					    "  %-31s\n",
524 					    pr->ps_pid, pr->ps_ucred->cr_ruid,
525 					    pr->ps_flags, p->p_flag,
526 					    CPU_INFO_UNIT(p->p_cpu),
527 					    p->p_comm);
528 					break;
529 
530 				}
531 			}
532 		}
533 		pr = LIST_NEXT(pr, ps_list);
534 		if (pr == NULL && skipzomb == 0) {
535 			skipzomb = 1;
536 			pr = LIST_FIRST(&zombprocess);
537 		}
538 	}
539 }
540 #endif
541 
542 #ifdef DEBUG
543 void
544 pgrpdump(void)
545 {
546 	struct pgrp *pgrp;
547 	struct process *pr;
548 	int i;
549 
550 	for (i = 0; i <= pgrphash; i++) {
551 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
552 			printf("\tindx %d\n", i);
553 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
554 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
555 				    pgrp, pgrp->pg_id, pgrp->pg_session,
556 				    pgrp->pg_session->s_count,
557 				    LIST_FIRST(&pgrp->pg_members));
558 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
559 					printf("\t\tpid %d addr %p pgrp %p\n",
560 					    pr->ps_pid, pr, pr->ps_pgrp);
561 				}
562 			}
563 		}
564 	}
565 }
566 #endif /* DEBUG */
567