xref: /openbsd-src/sys/kern/kern_proc.c (revision 5ff140d246573b102762c244776a1297acc30fd9)
1 /*	$OpenBSD: kern_proc.c,v 1.61 2014/11/03 03:08:00 deraadt 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, 0, "procpl",
97 	    &pool_allocator_nointr);
98 	pool_init(&process_pool, sizeof(struct process), 0, 0, 0, "processpl",
99 	    &pool_allocator_nointr);
100 	pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "zombiepl",
101 	    &pool_allocator_nointr);
102 	pool_init(&ucred_pool, sizeof(struct ucred), 0, 0, 0, "ucredpl",
103 	    &pool_allocator_nointr);
104 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl",
105 	    &pool_allocator_nointr);
106 	pool_init(&session_pool, sizeof(struct session), 0, 0, 0, "sessionpl",
107 	    &pool_allocator_nointr);
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 p 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  * Move p to a new or existing process group (and session)
209  * Caller provides a pre-allocated pgrp and session that should
210  * be freed if they are not used.
211  * XXX need proctree lock
212  */
213 int
214 enterpgrp(struct process *pr, pid_t pgid, struct pgrp *newpgrp,
215     struct session *newsess)
216 {
217 	struct pgrp *pgrp = pgfind(pgid);
218 
219 #ifdef DIAGNOSTIC
220 	if (pgrp != NULL && newsess)	/* firewalls */
221 		panic("enterpgrp: setsid into non-empty pgrp");
222 	if (SESS_LEADER(pr))
223 		panic("enterpgrp: session leader attempted setpgrp");
224 #endif
225 	if (pgrp == NULL) {
226 		/*
227 		 * new process group
228 		 */
229 #ifdef DIAGNOSTIC
230 		if (pr->ps_pid != pgid)
231 			panic("enterpgrp: new pgrp and pid != pgid");
232 #endif
233 
234 		pgrp = newpgrp;
235 		if (newsess) {
236 			/*
237 			 * new session
238 			 */
239 			newsess->s_leader = pr;
240 			newsess->s_count = 1;
241 			newsess->s_ttyvp = NULL;
242 			newsess->s_ttyp = NULL;
243 			bcopy(pr->ps_session->s_login, newsess->s_login,
244 			    sizeof(newsess->s_login));
245 			atomic_clearbits_int(&pr->ps_flags, PS_CONTROLT);
246 			pgrp->pg_session = newsess;
247 #ifdef DIAGNOSTIC
248 			if (pr != curproc->p_p)
249 				panic("enterpgrp: mksession but not curproc");
250 #endif
251 		} else {
252 			pgrp->pg_session = pr->ps_session;
253 			pgrp->pg_session->s_count++;
254 		}
255 		pgrp->pg_id = pgid;
256 		LIST_INIT(&pgrp->pg_members);
257 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
258 		pgrp->pg_jobc = 0;
259 	} else if (pgrp == pr->ps_pgrp) {
260 		if (newsess)
261 			pool_put(&session_pool, newsess);
262 		pool_put(&pgrp_pool, newpgrp);
263 		return (0);
264 	} else {
265 		if (newsess)
266 			pool_put(&session_pool, newsess);
267 		pool_put(&pgrp_pool, newpgrp);
268 	}
269 
270 	/*
271 	 * Adjust eligibility of affected pgrps to participate in job control.
272 	 * Increment eligibility counts before decrementing, otherwise we
273 	 * could reach 0 spuriously during the first call.
274 	 */
275 	fixjobc(pr, pgrp, 1);
276 	fixjobc(pr, pr->ps_pgrp, 0);
277 
278 	LIST_REMOVE(pr, ps_pglist);
279 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
280 		pgdelete(pr->ps_pgrp);
281 	pr->ps_pgrp = pgrp;
282 	LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
283 	return (0);
284 }
285 
286 /*
287  * remove process from process group
288  */
289 void
290 leavepgrp(struct process *pr)
291 {
292 
293 	LIST_REMOVE(pr, ps_pglist);
294 	if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
295 		pgdelete(pr->ps_pgrp);
296 	pr->ps_pgrp = 0;
297 }
298 
299 /*
300  * delete a process group
301  */
302 void
303 pgdelete(struct pgrp *pgrp)
304 {
305 
306 	if (pgrp->pg_session->s_ttyp != NULL &&
307 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
308 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
309 	LIST_REMOVE(pgrp, pg_hash);
310 	SESSRELE(pgrp->pg_session);
311 	pool_put(&pgrp_pool, pgrp);
312 }
313 
314 /*
315  * Adjust pgrp jobc counters when specified process changes process group.
316  * We count the number of processes in each process group that "qualify"
317  * the group for terminal job control (those with a parent in a different
318  * process group of the same session).  If that count reaches zero, the
319  * process group becomes orphaned.  Check both the specified process'
320  * process group and that of its children.
321  * entering == 0 => pr is leaving specified group.
322  * entering == 1 => pr is entering specified group.
323  * XXX need proctree lock
324  */
325 void
326 fixjobc(struct process *pr, struct pgrp *pgrp, int entering)
327 {
328 	struct pgrp *hispgrp;
329 	struct session *mysession = pgrp->pg_session;
330 
331 	/*
332 	 * Check pr's parent to see whether pr qualifies its own process
333 	 * group; if so, adjust count for pr's process group.
334 	 */
335 	if ((hispgrp = pr->ps_pptr->ps_pgrp) != pgrp &&
336 	    hispgrp->pg_session == mysession) {
337 		if (entering)
338 			pgrp->pg_jobc++;
339 		else if (--pgrp->pg_jobc == 0)
340 			orphanpg(pgrp);
341 	}
342 
343 	/*
344 	 * Check this process' children to see whether they qualify
345 	 * their process groups; if so, adjust counts for children's
346 	 * process groups.
347 	 */
348 	LIST_FOREACH(pr, &pr->ps_children, ps_sibling)
349 		if ((hispgrp = pr->ps_pgrp) != pgrp &&
350 		    hispgrp->pg_session == mysession &&
351 		    (pr->ps_flags & PS_ZOMBIE) == 0) {
352 			if (entering)
353 				hispgrp->pg_jobc++;
354 			else if (--hispgrp->pg_jobc == 0)
355 				orphanpg(hispgrp);
356 		}
357 }
358 
359 /*
360  * A process group has become orphaned;
361  * if there are any stopped processes in the group,
362  * hang-up all process in that group.
363  */
364 static void
365 orphanpg(struct pgrp *pg)
366 {
367 	struct process *pr;
368 
369 	LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
370 		if (pr->ps_mainproc->p_stat == SSTOP) {
371 			LIST_FOREACH(pr, &pg->pg_members, ps_pglist) {
372 				prsignal(pr, SIGHUP);
373 				prsignal(pr, SIGCONT);
374 			}
375 			return;
376 		}
377 	}
378 }
379 
380 #ifdef DDB
381 void
382 proc_printit(struct proc *p, const char *modif,
383     int (*pr)(const char *, ...) __attribute__((__format__(__kprintf__,1,2))))
384 {
385 	static const char *const pstat[] = {
386 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
387 	};
388 	char pstbuf[5];
389 	const char *pst = pstbuf;
390 
391 
392 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
393 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
394 	else
395 		pst = pstat[(int)p->p_stat - 1];
396 
397 	(*pr)("PROC (%s) pid=%d stat=%s\n", p->p_comm, p->p_pid, pst);
398 	(*pr)("    flags process=%b proc=%b\n",
399 	    p->p_p->ps_flags, PS_BITS, p->p_flag, P_BITS);
400 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
401 	    p->p_priority, p->p_usrpri, p->p_p->ps_nice);
402 	(*pr)("    forw=%p, list=%p,%p\n",
403 	    TAILQ_NEXT(p, p_runq), p->p_list.le_next, p->p_list.le_prev);
404 	(*pr)("    process=%p user=%p, vmspace=%p\n",
405 	    p->p_p, p->p_addr, p->p_vmspace);
406 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u\n",
407 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100);
408 	(*pr)("    user=%u, sys=%u, intr=%u\n",
409 	    p->p_uticks, p->p_sticks, p->p_iticks);
410 }
411 #include <machine/db_machdep.h>
412 
413 #include <ddb/db_interface.h>
414 #include <ddb/db_output.h>
415 
416 void
417 db_show_all_procs(db_expr_t addr, int haddr, db_expr_t count, char *modif)
418 {
419 	char *mode;
420 	int doingzomb = 0;
421 	struct proc *p;
422 	struct process *pr, *ppr;
423 
424 	if (modif[0] == 0)
425 		modif[0] = 'n';			/* default == normal mode */
426 
427 	mode = "mawn";
428 	while (*mode && *mode != modif[0])
429 		mode++;
430 	if (*mode == 0 || *mode == 'm') {
431 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
432 		db_printf("\t/a == show process address info\n");
433 		db_printf("\t/n == show normal process info [default]\n");
434 		db_printf("\t/w == show process wait/emul info\n");
435 		return;
436 	}
437 
438 	pr = LIST_FIRST(&allprocess);
439 
440 	switch (*mode) {
441 
442 	case 'a':
443 		db_printf("   PID  %-10s  %18s  %18s  %18s\n",
444 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
445 		break;
446 	case 'n':
447 		db_printf("   PID  %5s  %5s  %5s  S  %10s  %-12s  %-16s\n",
448 		    "PPID", "PGRP", "UID", "FLAGS", "WAIT", "COMMAND");
449 		break;
450 	case 'w':
451 		db_printf("   PID  %-16s  %-8s  %18s  %s\n",
452 		    "COMMAND", "EMUL", "WAIT-CHANNEL", "WAIT-MSG");
453 		break;
454 	}
455 
456 	while (pr != NULL) {
457 		ppr = pr->ps_pptr;
458 
459 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
460 			if (p->p_stat) {
461 				db_printf("%c%5d  ", p == curproc ? '*' : ' ',
462 					p->p_pid);
463 
464 				switch (*mode) {
465 
466 				case 'a':
467 					db_printf("%-10.10s  %18p  %18p  %18p\n",
468 					    p->p_comm, p, p->p_addr, p->p_vmspace);
469 					break;
470 
471 				case 'n':
472 					db_printf("%5d  %5d  %5d  %d  %#10x  "
473 					    "%-12.12s  %-16s\n",
474 					    ppr ? ppr->ps_pid : -1,
475 					    pr->ps_pgrp ? pr->ps_pgrp->pg_id : -1,
476 					    pr->ps_ucred->cr_ruid, p->p_stat,
477 					    p->p_flag | pr->ps_flags,
478 					    (p->p_wchan && p->p_wmesg) ?
479 						p->p_wmesg : "", p->p_comm);
480 					break;
481 
482 				case 'w':
483 					db_printf("%-16s  %-8s  %18p  %s\n", p->p_comm,
484 					    pr->ps_emul->e_name, p->p_wchan,
485 					    (p->p_wchan && p->p_wmesg) ?
486 						p->p_wmesg : "");
487 					break;
488 
489 				}
490 			}
491 		}
492 		pr = LIST_NEXT(pr, ps_list);
493 		if (pr == NULL && doingzomb == 0) {
494 			doingzomb = 1;
495 			pr = LIST_FIRST(&zombprocess);
496 		}
497 	}
498 }
499 #endif
500 
501 #ifdef DEBUG
502 void
503 pgrpdump(void)
504 {
505 	struct pgrp *pgrp;
506 	struct process *pr;
507 	int i;
508 
509 	for (i = 0; i <= pgrphash; i++) {
510 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
511 			printf("\tindx %d\n", i);
512 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
513 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
514 				    pgrp, pgrp->pg_id, pgrp->pg_session,
515 				    pgrp->pg_session->s_count,
516 				    LIST_FIRST(&pgrp->pg_members));
517 				LIST_FOREACH(pr, &pgrp->pg_members, ps_pglist) {
518 					printf("\t\tpid %d addr %p pgrp %p\n",
519 					    pr->ps_pid, pr, pr->ps_pgrp);
520 				}
521 			}
522 		}
523 	}
524 }
525 #endif /* DEBUG */
526