xref: /openbsd-src/sys/kern/kern_proc.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: kern_proc.c,v 1.55 2014/01/20 21:19:28 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 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 struct pool pcred_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 	pidhashtbl = hashinit(maxthread / 4, M_PROC, M_NOWAIT, &pidhash);
92 	pgrphashtbl = hashinit(maxprocess / 4, M_PROC, M_NOWAIT, &pgrphash);
93 	uihashtbl = hashinit(maxprocess / 16, M_PROC, M_NOWAIT, &uihash);
94 	if (!pidhashtbl || !pgrphashtbl || !uihashtbl)
95 		panic("procinit: malloc");
96 
97 	pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl",
98 	    &pool_allocator_nointr);
99 	pool_init(&process_pool, sizeof(struct process), 0, 0, 0, "processpl",
100 	    &pool_allocator_nointr);
101 	pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "zombiepl",
102 	    &pool_allocator_nointr);
103 	pool_init(&ucred_pool, sizeof(struct ucred), 0, 0, 0, "ucredpl",
104 	    &pool_allocator_nointr);
105 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl",
106 	    &pool_allocator_nointr);
107 	pool_init(&session_pool, sizeof(struct session), 0, 0, 0, "sessionpl",
108 	    &pool_allocator_nointr);
109 	pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl",
110 	    &pool_allocator_nointr);
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);
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 p 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 pfind(pid_t pid)
173 {
174 	struct proc *p;
175 
176 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
177 		if (p->p_pid == pid)
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 proc *p;
189 
190 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
191 		if (p->p_pid == pid)
192 			return (p->p_flag & P_THREAD ? NULL : p->p_p);
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  * Move p to a new or existing process group (and session)
212  * Caller provides a pre-allocated pgrp and session that should
213  * be freed if they are not used.
214  * XXX need proctree lock
215  */
216 int
217 enterpgrp(struct process *pr, pid_t pgid, struct pgrp *newpgrp,
218     struct session *newsess)
219 {
220 	struct pgrp *pgrp = pgfind(pgid);
221 
222 #ifdef DIAGNOSTIC
223 	if (pgrp != NULL && newsess)	/* firewalls */
224 		panic("enterpgrp: setsid into non-empty pgrp");
225 	if (SESS_LEADER(pr))
226 		panic("enterpgrp: session leader attempted setpgrp");
227 #endif
228 	if (pgrp == NULL) {
229 		/*
230 		 * new process group
231 		 */
232 #ifdef DIAGNOSTIC
233 		if (pr->ps_pid != pgid)
234 			panic("enterpgrp: new pgrp and pid != pgid");
235 #endif
236 
237 		pgrp = newpgrp;
238 		if (newsess) {
239 			/*
240 			 * new session
241 			 */
242 			newsess->s_leader = pr;
243 			newsess->s_count = 1;
244 			newsess->s_ttyvp = NULL;
245 			newsess->s_ttyp = NULL;
246 			bcopy(pr->ps_session->s_login, newsess->s_login,
247 			    sizeof(newsess->s_login));
248 			atomic_clearbits_int(&pr->ps_flags, PS_CONTROLT);
249 			pgrp->pg_session = newsess;
250 #ifdef DIAGNOSTIC
251 			if (pr != curproc->p_p)
252 				panic("enterpgrp: mksession but not curproc");
253 #endif
254 		} else {
255 			pgrp->pg_session = pr->ps_session;
256 			pgrp->pg_session->s_count++;
257 		}
258 		pgrp->pg_id = pgid;
259 		LIST_INIT(&pgrp->pg_members);
260 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
261 		pgrp->pg_jobc = 0;
262 	} else if (pgrp == pr->ps_pgrp) {
263 		if (newsess)
264 			pool_put(&session_pool, newsess);
265 		pool_put(&pgrp_pool, newpgrp);
266 		return (0);
267 	} else {
268 		if (newsess)
269 			pool_put(&session_pool, newsess);
270 		pool_put(&pgrp_pool, newpgrp);
271 	}
272 
273 	/*
274 	 * Adjust eligibility of affected pgrps to participate in job control.
275 	 * Increment eligibility counts before decrementing, otherwise we
276 	 * could reach 0 spuriously during the first call.
277 	 */
278 	fixjobc(pr, pgrp, 1);
279 	fixjobc(pr, pr->ps_pgrp, 0);
280 
281 	LIST_REMOVE(pr, ps_pglist);
282 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
283 		pgdelete(pr->ps_pgrp);
284 	pr->ps_pgrp = pgrp;
285 	LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
286 	return (0);
287 }
288 
289 /*
290  * remove process from process group
291  */
292 void
293 leavepgrp(struct process *pr)
294 {
295 
296 	LIST_REMOVE(pr, ps_pglist);
297 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
298 		pgdelete(pr->ps_pgrp);
299 	pr->ps_pgrp = 0;
300 }
301 
302 /*
303  * delete a process group
304  */
305 void
306 pgdelete(struct pgrp *pgrp)
307 {
308 
309 	if (pgrp->pg_session->s_ttyp != NULL &&
310 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
311 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
312 	LIST_REMOVE(pgrp, pg_hash);
313 	SESSRELE(pgrp->pg_session);
314 	pool_put(&pgrp_pool, pgrp);
315 }
316 
317 /*
318  * Adjust pgrp jobc counters when specified process changes process group.
319  * We count the number of processes in each process group that "qualify"
320  * the group for terminal job control (those with a parent in a different
321  * process group of the same session).  If that count reaches zero, the
322  * process group becomes orphaned.  Check both the specified process'
323  * process group and that of its children.
324  * entering == 0 => pr is leaving specified group.
325  * entering == 1 => pr is entering specified group.
326  * XXX need proctree lock
327  */
328 void
329 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
330 {
331 	struct pgrp *hispgrp;
332 	struct session *mysession = pgrp->pg_session;
333 
334 	/*
335 	 * Check pr's parent to see whether pr qualifies its own process
336 	 * group; if so, adjust count for pr's process group.
337 	 */
338 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
339 	    hispgrp->pg_session == mysession) {
340 		if (entering)
341 			pgrp->pg_jobc++;
342 		else if (--pgrp->pg_jobc == 0)
343 			orphanpg(pgrp);
344 	}
345 
346 	/*
347 	 * Check this process' children to see whether they qualify
348 	 * their process groups; if so, adjust counts for children's
349 	 * process groups.
350 	 */
351 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
352 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
353 		    hispgrp->pg_session == mysession &&
354 		    P_ZOMBIE(pr->ps_mainproc) == 0) {
355 			if (entering)
356 				hispgrp->pg_jobc++;
357 			else if (--hispgrp->pg_jobc == 0)
358 				orphanpg(hispgrp);
359 		}
360 }
361 
362 /*
363  * A process group has become orphaned;
364  * if there are any stopped processes in the group,
365  * hang-up all process in that group.
366  */
367 static void
368 orphanpg(struct pgrp *pg)
369 {
370 	struct process *pr;
371 
372 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
373 		if (pr->ps_mainproc->p_stat == SSTOP) {
374 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
375 				prsignal(pr, SIGHUP);
376 				prsignal(pr, SIGCONT);
377 			}
378 			return;
379 		}
380 	}
381 }
382 
383 #ifdef DDB
384 void
385 proc_printit(struct proc *p, const char *modif,
386     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
387 {
388 	static const char *const pstat[] = {
389 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
390 	};
391 	char pstbuf[5];
392 	const char *pst = pstbuf;
393 
394 
395 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
396 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
397 	else
398 		pst = pstat[(int)p->p_stat - 1];
399 
400 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_comm, p->p_pid, pst);
401 	(*pr)("    flags process=%b proc=%b\n",
402 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
403 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
404 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
405 	(*pr)("    forw=%p, list=%p,%p\n",
406 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
407 	(*pr)("    process=%p user=%p, vmspace=%p\n",
408 	    p->p_p, p->p_addr, p->p_vmspace);
409 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u, swtime=%u\n",
410 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100,
411 	    p->p_swtime);
412 	(*pr)("    user=%u, sys=%u, intr=%u\n",
413 	    p->p_uticks, p->p_sticks, p->p_iticks);
414 }
415 #include <machine/db_machdep.h>
416 
417 #include <ddb/db_interface.h>
418 #include <ddb/db_output.h>
419 
420 void
421 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
422 {
423 	char *mode;
424 	int doingzomb = 0;
425 	struct proc *p;
426 	struct process *pr, *ppr;
427 
428 	if (modif[0] == 0)
429 		modif[0] = 'n';			/* default == normal mode */
430 
431 	mode = "mawn";
432 	while (*mode && *mode != modif[0])
433 		mode++;
434 	if (*mode == 0 || *mode == 'm') {
435 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
436 		db_printf("\t/a == show process address info\n");
437 		db_printf("\t/n == show normal process info [default]\n");
438 		db_printf("\t/w == show process wait/emul info\n");
439 		return;
440 	}
441 
442 	pr = LIST_FIRST(&allprocess);
443 
444 	switch (*mode) {
445 
446 	case 'a':
447 		db_printf("   PID  %-10s  %18s  %18s  %18s\n",
448 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
449 		break;
450 	case 'n':
451 		db_printf("   PID  %5s  %5s  %5s  S  %10s  %-12s  %-16s\n",
452 		    "PPID", "PGRP", "UID", "FLAGS", "WAIT", "COMMAND");
453 		break;
454 	case 'w':
455 		db_printf("   PID  %-16s  %-8s  %18s  %s\n",
456 		    "COMMAND", "EMUL", "WAIT-CHANNEL", "WAIT-MSG");
457 		break;
458 	}
459 
460 	while (pr != NULL) {
461 		ppr = pr->ps_pptr;
462 
463 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
464 			if (p->p_stat) {
465 				db_printf("%c%5d  ", p == curproc ? '*' : ' ',
466 					p->p_pid);
467 
468 				switch (*mode) {
469 
470 				case 'a':
471 					db_printf("%-10.10s  %18p  %18p  %18p\n",
472 					    p->p_comm, p, p->p_addr, p->p_vmspace);
473 					break;
474 
475 				case 'n':
476 					db_printf("%5d  %5d  %5d  %d  %#10x  "
477 					    "%-12.12s  %-16s\n",
478 					    ppr ? ppr->ps_pid : -1,
479 					    pr->ps_pgrp ? pr->ps_pgrp->pg_id : -1,
480 					    pr->ps_cred->p_ruid, p->p_stat,
481 					    p->p_flag | pr->ps_flags,
482 					    (p->p_wchan && p->p_wmesg) ?
483 						p->p_wmesg : "", p->p_comm);
484 					break;
485 
486 				case 'w':
487 					db_printf("%-16s  %-8s  %18p  %s\n", p->p_comm,
488 					    p->p_emul->e_name, p->p_wchan,
489 					    (p->p_wchan && p->p_wmesg) ?
490 						p->p_wmesg : "");
491 					break;
492 
493 				}
494 			}
495 		}
496 		pr = LIST_NEXT(pr, ps_list);
497 		if (pr == NULL && doingzomb == 0) {
498 			doingzomb = 1;
499 			pr = LIST_FIRST(&zombprocess);
500 		}
501 	}
502 }
503 #endif
504 
505 #ifdef DEBUG
506 void
507 pgrpdump(void)
508 {
509 	struct pgrp *pgrp;
510 	struct process *pr;
511 	int i;
512 
513 	for (i = 0; i <= pgrphash; i++) {
514 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
515 			printf("\tindx %d\n", i);
516 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
517 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
518 				    pgrp, pgrp->pg_id, pgrp->pg_session,
519 				    pgrp->pg_session->s_count,
520 				    LIST_FIRST(&pgrp->pg_members));
521 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
522 					printf("\t\tpid %d addr %p pgrp %p\n",
523 					    pr->ps_pid, pr, pr->ps_pgrp);
524 				}
525 			}
526 		}
527 	}
528 }
529 #endif /* DEBUG */
530