xref: /openbsd-src/sys/kern/kern_proc.c (revision fb8aa7497fded39583f40e800732f9c046411717)
1 /*	$OpenBSD: kern_proc.c,v 1.67 2016/06/27 19:55:02 jca 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_init(&process_pool, sizeof(struct process), 0, 0, PR_WAITOK,
99 	    "processpl", NULL);
100 	pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, PR_WAITOK,
101 	    "zombiepl", NULL);
102 	pool_init(&ucred_pool, sizeof(struct ucred), 0, 0, PR_WAITOK,
103 	    "ucredpl", NULL);
104 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, PR_WAITOK,
105 	    "pgrppl", NULL);
106 	pool_init(&session_pool, sizeof(struct session), 0, 0, PR_WAITOK,
107 	    "sessionpl", NULL);
108 }
109 
110 struct uidinfo *
111 uid_find(uid_t uid)
112 {
113 	struct uidinfo *uip, *nuip;
114 	struct uihashhead *uipp;
115 
116 	uipp = UIHASH(uid);
117 	LIST_FOREACH(uip, uipp, ui_hash)
118 		if (uip->ui_uid == uid)
119 			break;
120 	if (uip)
121 		return (uip);
122 	nuip = malloc(sizeof(*nuip), M_PROC, M_WAITOK|M_ZERO);
123 	LIST_FOREACH(uip, uipp, ui_hash)
124 		if (uip->ui_uid == uid)
125 			break;
126 	if (uip) {
127 		free(nuip, M_PROC, sizeof(*nuip));
128 		return (uip);
129 	}
130 	nuip->ui_uid = uid;
131 	LIST_INSERT_HEAD(uipp, nuip, ui_hash);
132 
133 	return (nuip);
134 }
135 
136 /*
137  * Change the count associated with number of threads
138  * a given user is using.
139  */
140 int
141 chgproccnt(uid_t uid, int diff)
142 {
143 	struct uidinfo *uip;
144 
145 	uip = uid_find(uid);
146 	uip->ui_proccnt += diff;
147 	if (uip->ui_proccnt < 0)
148 		panic("chgproccnt: procs < 0");
149 	return (uip->ui_proccnt);
150 }
151 
152 /*
153  * Is pr an inferior of parent?
154  */
155 int
156 inferior(struct process *pr, struct process *parent)
157 {
158 
159 	for (; pr != parent; pr = pr->ps_pptr)
160 		if (pr->ps_pid == 0 || pr->ps_pid == 1)
161 			return (0);
162 	return (1);
163 }
164 
165 /*
166  * Locate a proc (thread) by number
167  */
168 struct proc *
169 pfind(pid_t pid)
170 {
171 	struct proc *p;
172 
173 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
174 		if (p->p_pid == pid)
175 			return (p);
176 	return (NULL);
177 }
178 
179 /*
180  * Locate a process by number
181  */
182 struct process *
183 prfind(pid_t pid)
184 {
185 	struct proc *p;
186 
187 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
188 		if (p->p_pid == pid)
189 			return (p->p_flag & P_THREAD ? NULL : p->p_p);
190 	return (NULL);
191 }
192 
193 /*
194  * Locate a process group by number
195  */
196 struct pgrp *
197 pgfind(pid_t pgid)
198 {
199 	struct pgrp *pgrp;
200 
201 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
202 		if (pgrp->pg_id == pgid)
203 			return (pgrp);
204 	return (NULL);
205 }
206 
207 /*
208  * Locate a zombie process
209  */
210 struct process *
211 zombiefind(pid_t pid)
212 {
213 	struct process *pr;
214 
215 	LIST_FOREACH(pr, &zombprocess, ps_list)
216 		if (pr->ps_mainproc->p_pid == pid)
217 			return (pr);
218 	return (NULL);
219 }
220 
221 /*
222  * Move p to a new or existing process group (and session)
223  * Caller provides a pre-allocated pgrp and session that should
224  * be freed if they are not used.
225  * XXX need proctree lock
226  */
227 int
228 enterpgrp(struct process *pr, pid_t pgid, struct pgrp *newpgrp,
229     struct session *newsess)
230 {
231 	struct pgrp *pgrp = pgfind(pgid);
232 
233 #ifdef DIAGNOSTIC
234 	if (pgrp != NULL && newsess)	/* firewalls */
235 		panic("enterpgrp: setsid into non-empty pgrp");
236 	if (SESS_LEADER(pr))
237 		panic("enterpgrp: session leader attempted setpgrp");
238 #endif
239 	if (pgrp == NULL) {
240 		/*
241 		 * new process group
242 		 */
243 #ifdef DIAGNOSTIC
244 		if (pr->ps_pid != pgid)
245 			panic("enterpgrp: new pgrp and pid != pgid");
246 #endif
247 
248 		pgrp = newpgrp;
249 		if (newsess) {
250 			/*
251 			 * new session
252 			 */
253 			newsess->s_leader = pr;
254 			newsess->s_count = 1;
255 			newsess->s_ttyvp = NULL;
256 			newsess->s_ttyp = NULL;
257 			memcpy(newsess->s_login, pr->ps_session->s_login,
258 			    sizeof(newsess->s_login));
259 			atomic_clearbits_int(&pr->ps_flags, PS_CONTROLT);
260 			pgrp->pg_session = newsess;
261 #ifdef DIAGNOSTIC
262 			if (pr != curproc->p_p)
263 				panic("enterpgrp: mksession but not curproc");
264 #endif
265 		} else {
266 			pgrp->pg_session = pr->ps_session;
267 			pgrp->pg_session->s_count++;
268 		}
269 		pgrp->pg_id = pgid;
270 		LIST_INIT(&pgrp->pg_members);
271 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
272 		pgrp->pg_jobc = 0;
273 	} else if (pgrp == pr->ps_pgrp) {
274 		if (newsess)
275 			pool_put(&session_pool, newsess);
276 		pool_put(&pgrp_pool, newpgrp);
277 		return (0);
278 	} else {
279 		if (newsess)
280 			pool_put(&session_pool, newsess);
281 		pool_put(&pgrp_pool, newpgrp);
282 	}
283 
284 	/*
285 	 * Adjust eligibility of affected pgrps to participate in job control.
286 	 * Increment eligibility counts before decrementing, otherwise we
287 	 * could reach 0 spuriously during the first call.
288 	 */
289 	fixjobc(pr, pgrp, 1);
290 	fixjobc(pr, pr->ps_pgrp, 0);
291 
292 	LIST_REMOVE(pr, ps_pglist);
293 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
294 		pgdelete(pr->ps_pgrp);
295 	pr->ps_pgrp = pgrp;
296 	LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
297 	return (0);
298 }
299 
300 /*
301  * remove process from process group
302  */
303 void
304 leavepgrp(struct process *pr)
305 {
306 
307 	LIST_REMOVE(pr, ps_pglist);
308 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
309 		pgdelete(pr->ps_pgrp);
310 	pr->ps_pgrp = 0;
311 }
312 
313 /*
314  * delete a process group
315  */
316 void
317 pgdelete(struct pgrp *pgrp)
318 {
319 
320 	if (pgrp->pg_session->s_ttyp != NULL &&
321 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
322 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
323 	LIST_REMOVE(pgrp, pg_hash);
324 	SESSRELE(pgrp->pg_session);
325 	pool_put(&pgrp_pool, pgrp);
326 }
327 
328 /*
329  * Adjust pgrp jobc counters when specified process changes process group.
330  * We count the number of processes in each process group that "qualify"
331  * the group for terminal job control (those with a parent in a different
332  * process group of the same session).  If that count reaches zero, the
333  * process group becomes orphaned.  Check both the specified process'
334  * process group and that of its children.
335  * entering == 0 => pr is leaving specified group.
336  * entering == 1 => pr is entering specified group.
337  * XXX need proctree lock
338  */
339 void
340 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
341 {
342 	struct pgrp *hispgrp;
343 	struct session *mysession = pgrp->pg_session;
344 
345 	/*
346 	 * Check pr's parent to see whether pr qualifies its own process
347 	 * group; if so, adjust count for pr's process group.
348 	 */
349 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
350 	    hispgrp->pg_session == mysession) {
351 		if (entering)
352 			pgrp->pg_jobc++;
353 		else if (--pgrp->pg_jobc == 0)
354 			orphanpg(pgrp);
355 	}
356 
357 	/*
358 	 * Check this process' children to see whether they qualify
359 	 * their process groups; if so, adjust counts for children's
360 	 * process groups.
361 	 */
362 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
363 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
364 		    hispgrp->pg_session == mysession &&
365 		    (pr->ps_flags & PS_ZOMBIE) == 0) {
366 			if (entering)
367 				hispgrp->pg_jobc++;
368 			else if (--hispgrp->pg_jobc == 0)
369 				orphanpg(hispgrp);
370 		}
371 }
372 
373 /*
374  * A process group has become orphaned;
375  * if there are any stopped processes in the group,
376  * hang-up all process in that group.
377  */
378 static void
379 orphanpg(struct pgrp *pg)
380 {
381 	struct process *pr;
382 
383 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
384 		if (pr->ps_mainproc->p_stat == SSTOP) {
385 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
386 				prsignal(pr, SIGHUP);
387 				prsignal(pr, SIGCONT);
388 			}
389 			return;
390 		}
391 	}
392 }
393 
394 #ifdef DDB
395 void
396 proc_printit(struct proc *p, const char *modif,
397     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
398 {
399 	static const char *const pstat[] = {
400 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
401 	};
402 	char pstbuf[5];
403 	const char *pst = pstbuf;
404 
405 
406 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
407 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
408 	else
409 		pst = pstat[(int)p->p_stat - 1];
410 
411 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_comm, p->p_pid, pst);
412 	(*pr)("    flags process=%b proc=%b\n",
413 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
414 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
415 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
416 	(*pr)("    forw=%p, list=%p,%p\n",
417 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
418 	(*pr)("    process=%p user=%p, vmspace=%p\n",
419 	    p->p_p, p->p_addr, p->p_vmspace);
420 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u\n",
421 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100);
422 	(*pr)("    user=%u, sys=%u, intr=%u\n",
423 	    p->p_uticks, p->p_sticks, p->p_iticks);
424 }
425 #include <machine/db_machdep.h>
426 
427 #include <ddb/db_output.h>
428 
429 void
430 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
431 {
432 	char *mode;
433 	int skipzomb = 0;
434 	struct proc *p;
435 	struct process *pr, *ppr;
436 
437 	if (modif[0] == 0)
438 		modif[0] = 'n';			/* default == normal mode */
439 
440 	mode = "mawno";
441 	while (*mode && *mode != modif[0])
442 		mode++;
443 	if (*mode == 0 || *mode == 'm') {
444 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
445 		db_printf("\t/a == show process address info\n");
446 		db_printf("\t/n == show normal process info [default]\n");
447 		db_printf("\t/w == show process wait/emul info\n");
448 		db_printf("\t/o == show normal info for non-idle SONPROC\n");
449 		return;
450 	}
451 
452 	pr = LIST_FIRST(&allprocess);
453 
454 	switch (*mode) {
455 
456 	case 'a':
457 		db_printf("   TID  %-10s  %18s  %18s  %18s\n",
458 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
459 		break;
460 	case 'n':
461 		db_printf("   TID  %5s  %5s  %5s  S  %10s  %-12s  %-16s\n",
462 		    "PPID", "PGRP", "UID", "FLAGS", "WAIT", "COMMAND");
463 		break;
464 	case 'w':
465 		db_printf("   TID  %-16s  %-8s  %18s  %s\n",
466 		    "COMMAND", "EMUL", "WAIT-CHANNEL", "WAIT-MSG");
467 		break;
468 	case 'o':
469 		skipzomb = 1;
470 		db_printf("   TID  %5s  %5s  %10s %10s  %3s  %-31s\n",
471 		    "PID", "UID", "PRFLAGS", "PFLAGS", "CPU", "COMMAND");
472 		break;
473 	}
474 
475 	while (pr != NULL) {
476 		ppr = pr->ps_pptr;
477 
478 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
479 			if (p->p_stat) {
480 				if (*mode == 'o') {
481 					if (p->p_stat != SONPROC)
482 						continue;
483 					if (p->p_cpu != NULL && p->p_cpu->
484 					    ci_schedstate.spc_idleproc == p)
485 						continue;
486 				}
487 				db_printf("%c%5d  ", p == curproc ? '*' : ' ',
488 					p->p_pid);
489 
490 				switch (*mode) {
491 
492 				case 'a':
493 					db_printf("%-10.10s  %18p  %18p  %18p\n",
494 					    p->p_comm, p, p->p_addr, p->p_vmspace);
495 					break;
496 
497 				case 'n':
498 					db_printf("%5d  %5d  %5d  %d  %#10x  "
499 					    "%-12.12s  %-16s\n",
500 					    ppr ? ppr->ps_pid : -1,
501 					    pr->ps_pgrp ? pr->ps_pgrp->pg_id : -1,
502 					    pr->ps_ucred->cr_ruid, p->p_stat,
503 					    p->p_flag | pr->ps_flags,
504 					    (p->p_wchan && p->p_wmesg) ?
505 						p->p_wmesg : "", p->p_comm);
506 					break;
507 
508 				case 'w':
509 					db_printf("%-16s  %-8s  %18p  %s\n", p->p_comm,
510 					    pr->ps_emul->e_name, p->p_wchan,
511 					    (p->p_wchan && p->p_wmesg) ?
512 						p->p_wmesg : "");
513 					break;
514 
515 				case 'o':
516 					db_printf("%5d  %5d  %#10x %#10x  %3d"
517 					    "  %-31s\n",
518 					    pr->ps_pid, pr->ps_ucred->cr_ruid,
519 					    pr->ps_flags, p->p_flag,
520 					    CPU_INFO_UNIT(p->p_cpu),
521 					    p->p_comm);
522 					break;
523 
524 				}
525 			}
526 		}
527 		pr = LIST_NEXT(pr, ps_list);
528 		if (pr == NULL && skipzomb == 0) {
529 			skipzomb = 1;
530 			pr = LIST_FIRST(&zombprocess);
531 		}
532 	}
533 }
534 #endif
535 
536 #ifdef DEBUG
537 void
538 pgrpdump(void)
539 {
540 	struct pgrp *pgrp;
541 	struct process *pr;
542 	int i;
543 
544 	for (i = 0; i <= pgrphash; i++) {
545 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
546 			printf("\tindx %d\n", i);
547 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
548 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
549 				    pgrp, pgrp->pg_id, pgrp->pg_session,
550 				    pgrp->pg_session->s_count,
551 				    LIST_FIRST(&pgrp->pg_members));
552 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
553 					printf("\t\tpid %d addr %p pgrp %p\n",
554 					    pr->ps_pid, pr, pr->ps_pgrp);
555 				}
556 			}
557 		}
558 	}
559 }
560 #endif /* DEBUG */
561