xref: /openbsd-src/sys/kern/kern_proc.c (revision bb5dd46a8458ce3e04e7bbee8bfe3ad51905912d)
1 /*	$OpenBSD: kern_proc.c,v 1.69 2016/09/02 18:11:28 tedu 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 	if (pr->ps_session->s_verauthppid == pr->ps_pid)
314 		zapverauth(pr->ps_session);
315 	LIST_REMOVE(pr, ps_pglist);
316 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
317 		pgdelete(pr->ps_pgrp);
318 	pr->ps_pgrp = 0;
319 }
320 
321 /*
322  * delete a process group
323  */
324 void
325 pgdelete(struct pgrp *pgrp)
326 {
327 
328 	if (pgrp->pg_session->s_ttyp != NULL &&
329 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
330 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
331 	LIST_REMOVE(pgrp, pg_hash);
332 	SESSRELE(pgrp->pg_session);
333 	pool_put(&pgrp_pool, pgrp);
334 }
335 
336 void
337 zapverauth(void *v)
338 {
339 	struct session *sess = v;
340 	sess->s_verauthuid = 0;
341 	sess->s_verauthppid = 0;
342 }
343 
344 /*
345  * Adjust pgrp jobc counters when specified process changes process group.
346  * We count the number of processes in each process group that "qualify"
347  * the group for terminal job control (those with a parent in a different
348  * process group of the same session).  If that count reaches zero, the
349  * process group becomes orphaned.  Check both the specified process'
350  * process group and that of its children.
351  * entering == 0 => pr is leaving specified group.
352  * entering == 1 => pr is entering specified group.
353  * XXX need proctree lock
354  */
355 void
356 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
357 {
358 	struct pgrp *hispgrp;
359 	struct session *mysession = pgrp->pg_session;
360 
361 	/*
362 	 * Check pr's parent to see whether pr qualifies its own process
363 	 * group; if so, adjust count for pr's process group.
364 	 */
365 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
366 	    hispgrp->pg_session == mysession) {
367 		if (entering)
368 			pgrp->pg_jobc++;
369 		else if (--pgrp->pg_jobc == 0)
370 			orphanpg(pgrp);
371 	}
372 
373 	/*
374 	 * Check this process' children to see whether they qualify
375 	 * their process groups; if so, adjust counts for children's
376 	 * process groups.
377 	 */
378 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
379 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
380 		    hispgrp->pg_session == mysession &&
381 		    (pr->ps_flags & PS_ZOMBIE) == 0) {
382 			if (entering)
383 				hispgrp->pg_jobc++;
384 			else if (--hispgrp->pg_jobc == 0)
385 				orphanpg(hispgrp);
386 		}
387 }
388 
389 /*
390  * A process group has become orphaned;
391  * if there are any stopped processes in the group,
392  * hang-up all process in that group.
393  */
394 static void
395 orphanpg(struct pgrp *pg)
396 {
397 	struct process *pr;
398 
399 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
400 		if (pr->ps_mainproc->p_stat == SSTOP) {
401 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
402 				prsignal(pr, SIGHUP);
403 				prsignal(pr, SIGCONT);
404 			}
405 			return;
406 		}
407 	}
408 }
409 
410 #ifdef DDB
411 void
412 proc_printit(struct proc *p, const char *modif,
413     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
414 {
415 	static const char *const pstat[] = {
416 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
417 	};
418 	char pstbuf[5];
419 	const char *pst = pstbuf;
420 
421 
422 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
423 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
424 	else
425 		pst = pstat[(int)p->p_stat - 1];
426 
427 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_comm, p->p_pid, pst);
428 	(*pr)("    flags process=%b proc=%b\n",
429 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
430 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
431 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
432 	(*pr)("    forw=%p, list=%p,%p\n",
433 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
434 	(*pr)("    process=%p user=%p, vmspace=%p\n",
435 	    p->p_p, p->p_addr, p->p_vmspace);
436 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u\n",
437 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100);
438 	(*pr)("    user=%u, sys=%u, intr=%u\n",
439 	    p->p_uticks, p->p_sticks, p->p_iticks);
440 }
441 #include <machine/db_machdep.h>
442 
443 #include <ddb/db_output.h>
444 
445 void
446 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
447 {
448 	char *mode;
449 	int skipzomb = 0;
450 	struct proc *p;
451 	struct process *pr, *ppr;
452 
453 	if (modif[0] == 0)
454 		modif[0] = 'n';			/* default == normal mode */
455 
456 	mode = "mawno";
457 	while (*mode && *mode != modif[0])
458 		mode++;
459 	if (*mode == 0 || *mode == 'm') {
460 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
461 		db_printf("\t/a == show process address info\n");
462 		db_printf("\t/n == show normal process info [default]\n");
463 		db_printf("\t/w == show process wait/emul info\n");
464 		db_printf("\t/o == show normal info for non-idle SONPROC\n");
465 		return;
466 	}
467 
468 	pr = LIST_FIRST(&allprocess);
469 
470 	switch (*mode) {
471 
472 	case 'a':
473 		db_printf("   TID  %-10s  %18s  %18s  %18s\n",
474 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
475 		break;
476 	case 'n':
477 		db_printf("   TID  %5s  %5s  %5s  S  %10s  %-12s  %-16s\n",
478 		    "PPID", "PGRP", "UID", "FLAGS", "WAIT", "COMMAND");
479 		break;
480 	case 'w':
481 		db_printf("   TID  %-16s  %-8s  %18s  %s\n",
482 		    "COMMAND", "EMUL", "WAIT-CHANNEL", "WAIT-MSG");
483 		break;
484 	case 'o':
485 		skipzomb = 1;
486 		db_printf("   TID  %5s  %5s  %10s %10s  %3s  %-31s\n",
487 		    "PID", "UID", "PRFLAGS", "PFLAGS", "CPU", "COMMAND");
488 		break;
489 	}
490 
491 	while (pr != NULL) {
492 		ppr = pr->ps_pptr;
493 
494 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
495 			if (p->p_stat) {
496 				if (*mode == 'o') {
497 					if (p->p_stat != SONPROC)
498 						continue;
499 					if (p->p_cpu != NULL && p->p_cpu->
500 					    ci_schedstate.spc_idleproc == p)
501 						continue;
502 				}
503 				db_printf("%c%5d  ", p == curproc ? '*' : ' ',
504 					p->p_pid);
505 
506 				switch (*mode) {
507 
508 				case 'a':
509 					db_printf("%-10.10s  %18p  %18p  %18p\n",
510 					    p->p_comm, p, p->p_addr, p->p_vmspace);
511 					break;
512 
513 				case 'n':
514 					db_printf("%5d  %5d  %5d  %d  %#10x  "
515 					    "%-12.12s  %-16s\n",
516 					    ppr ? ppr->ps_pid : -1,
517 					    pr->ps_pgrp ? pr->ps_pgrp->pg_id : -1,
518 					    pr->ps_ucred->cr_ruid, p->p_stat,
519 					    p->p_flag | pr->ps_flags,
520 					    (p->p_wchan && p->p_wmesg) ?
521 						p->p_wmesg : "", p->p_comm);
522 					break;
523 
524 				case 'w':
525 					db_printf("%-16s  %-8s  %18p  %s\n", p->p_comm,
526 					    pr->ps_emul->e_name, p->p_wchan,
527 					    (p->p_wchan && p->p_wmesg) ?
528 						p->p_wmesg : "");
529 					break;
530 
531 				case 'o':
532 					db_printf("%5d  %5d  %#10x %#10x  %3d"
533 					    "  %-31s\n",
534 					    pr->ps_pid, pr->ps_ucred->cr_ruid,
535 					    pr->ps_flags, p->p_flag,
536 					    CPU_INFO_UNIT(p->p_cpu),
537 					    p->p_comm);
538 					break;
539 
540 				}
541 			}
542 		}
543 		pr = LIST_NEXT(pr, ps_list);
544 		if (pr == NULL && skipzomb == 0) {
545 			skipzomb = 1;
546 			pr = LIST_FIRST(&zombprocess);
547 		}
548 	}
549 }
550 #endif
551 
552 #ifdef DEBUG
553 void
554 pgrpdump(void)
555 {
556 	struct pgrp *pgrp;
557 	struct process *pr;
558 	int i;
559 
560 	for (i = 0; i <= pgrphash; i++) {
561 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
562 			printf("\tindx %d\n", i);
563 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
564 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
565 				    pgrp, pgrp->pg_id, pgrp->pg_session,
566 				    pgrp->pg_session->s_count,
567 				    LIST_FIRST(&pgrp->pg_members));
568 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
569 					printf("\t\tpid %d addr %p pgrp %p\n",
570 					    pr->ps_pid, pr, pr->ps_pgrp);
571 				}
572 			}
573 		}
574 	}
575 }
576 #endif /* DEBUG */
577