xref: /openbsd-src/sys/kern/kern_proc.c (revision da90d235d9a0994d7ea5dba99a7c0b53d9268201)
1 /*	$OpenBSD: kern_proc.c,v 1.25 2005/03/10 17:26:10 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 proclist allproc;
64 struct proclist zombproc;
65 
66 struct pool proc_pool;
67 struct pool rusage_pool;
68 struct pool ucred_pool;
69 struct pool pgrp_pool;
70 struct pool session_pool;
71 struct pool pcred_pool;
72 
73 static void orphanpg(struct pgrp *);
74 #ifdef DEBUG
75 void pgrpdump(void);
76 #endif
77 
78 /*
79  * Initialize global process hashing structures.
80  */
81 void
82 procinit()
83 {
84 
85 	LIST_INIT(&allproc);
86 	LIST_INIT(&zombproc);
87 
88 	pidhashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pidhash);
89 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, M_WAITOK, &pgrphash);
90 	uihashtbl = hashinit(maxproc / 16, M_PROC, M_WAITOK, &uihash);
91 
92 	pool_init(&proc_pool, sizeof(struct proc), 0, 0, 0, "procpl",
93 	    &pool_allocator_nointr);
94 	pool_init(&rusage_pool, sizeof(struct rusage), 0, 0, 0, "zombiepl",
95 	    &pool_allocator_nointr);
96 	pool_init(&ucred_pool, sizeof(struct ucred), 0, 0, 0, "ucredpl",
97 	    &pool_allocator_nointr);
98 	pool_init(&pgrp_pool, sizeof(struct pgrp), 0, 0, 0, "pgrppl",
99 	    &pool_allocator_nointr);
100 	pool_init(&session_pool, sizeof(struct session), 0, 0, 0, "sessionpl",
101 	    &pool_allocator_nointr);
102 	pool_init(&pcred_pool, sizeof(struct pcred), 0, 0, 0, "pcredpl",
103 	    &pool_allocator_nointr);
104 }
105 
106 /*
107  * Change the count associated with number of processes
108  * a given user is using.
109  */
110 struct uidinfo *
111 uid_find(uid_t uid)
112 {
113 	struct uidinfo *uip;
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 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
123 	bzero(uip, sizeof(*uip));
124 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
125 	uip->ui_uid = uid;
126 
127 	return (uip);
128 }
129 
130 int
131 chgproccnt(uid_t uid, int diff)
132 {
133 	struct uidinfo *uip;
134 
135 	uip = uid_find(uid);
136 	uip->ui_proccnt += diff;
137 	if (uip->ui_proccnt < 0)
138 		panic("chgproccnt: procs < 0");
139 	return (uip->ui_proccnt);
140 }
141 
142 /*
143  * Is p an inferior of the current process?
144  */
145 int
146 inferior(p)
147 	register struct proc *p;
148 {
149 
150 	for (; p != curproc; p = p->p_pptr)
151 		if (p->p_pid == 0)
152 			return (0);
153 	return (1);
154 }
155 
156 /*
157  * Locate a process by number
158  */
159 struct proc *
160 pfind(pid)
161 	register pid_t pid;
162 {
163 	register struct proc *p;
164 
165 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
166 		if (p->p_pid == pid)
167 			return (p);
168 	return (NULL);
169 }
170 
171 /*
172  * Locate a process group by number
173  */
174 struct pgrp *
175 pgfind(pgid)
176 	register pid_t pgid;
177 {
178 	register struct pgrp *pgrp;
179 
180 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
181 		if (pgrp->pg_id == pgid)
182 			return (pgrp);
183 	return (NULL);
184 }
185 
186 /*
187  * Move p to a new or existing process group (and session)
188  */
189 int
190 enterpgrp(p, pgid, mksess)
191 	register struct proc *p;
192 	pid_t pgid;
193 	int mksess;
194 {
195 	register struct pgrp *pgrp = pgfind(pgid);
196 
197 #ifdef DIAGNOSTIC
198 	if (pgrp != NULL && mksess)	/* firewalls */
199 		panic("enterpgrp: setsid into non-empty pgrp");
200 	if (SESS_LEADER(p))
201 		panic("enterpgrp: session leader attempted setpgrp");
202 #endif
203 	if (pgrp == NULL) {
204 		pid_t savepid = p->p_pid;
205 		struct proc *np;
206 		/*
207 		 * new process group
208 		 */
209 #ifdef DIAGNOSTIC
210 		if (p->p_pid != pgid)
211 			panic("enterpgrp: new pgrp and pid != pgid");
212 #endif
213 		if ((np = pfind(savepid)) == NULL || np != p)
214 			return (ESRCH);
215 		pgrp = pool_get(&pgrp_pool, PR_WAITOK);
216 		if (mksess) {
217 			register struct session *sess;
218 
219 			/*
220 			 * new session
221 			 */
222 			sess = pool_get(&session_pool, PR_WAITOK);
223 			sess->s_leader = p;
224 			sess->s_count = 1;
225 			sess->s_ttyvp = NULL;
226 			sess->s_ttyp = NULL;
227 			bcopy(p->p_session->s_login, sess->s_login,
228 			    sizeof(sess->s_login));
229 			p->p_flag &= ~P_CONTROLT;
230 			pgrp->pg_session = sess;
231 #ifdef DIAGNOSTIC
232 			if (p != curproc)
233 				panic("enterpgrp: mksession and p != curproc");
234 #endif
235 		} else {
236 			pgrp->pg_session = p->p_session;
237 			pgrp->pg_session->s_count++;
238 		}
239 		pgrp->pg_id = pgid;
240 		LIST_INIT(&pgrp->pg_members);
241 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
242 		pgrp->pg_jobc = 0;
243 	} else if (pgrp == p->p_pgrp)
244 		return (0);
245 
246 	/*
247 	 * Adjust eligibility of affected pgrps to participate in job control.
248 	 * Increment eligibility counts before decrementing, otherwise we
249 	 * could reach 0 spuriously during the first call.
250 	 */
251 	fixjobc(p, pgrp, 1);
252 	fixjobc(p, p->p_pgrp, 0);
253 
254 	LIST_REMOVE(p, p_pglist);
255 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
256 		pgdelete(p->p_pgrp);
257 	p->p_pgrp = pgrp;
258 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
259 	return (0);
260 }
261 
262 /*
263  * remove process from process group
264  */
265 int
266 leavepgrp(p)
267 	register struct proc *p;
268 {
269 
270 	LIST_REMOVE(p, p_pglist);
271 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
272 		pgdelete(p->p_pgrp);
273 	p->p_pgrp = 0;
274 	return (0);
275 }
276 
277 /*
278  * delete a process group
279  */
280 void
281 pgdelete(pgrp)
282 	register struct pgrp *pgrp;
283 {
284 
285 	if (pgrp->pg_session->s_ttyp != NULL &&
286 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
287 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
288 	LIST_REMOVE(pgrp, pg_hash);
289 	SESSRELE(pgrp->pg_session);
290 	pool_put(&pgrp_pool, pgrp);
291 }
292 
293 /*
294  * Adjust pgrp jobc counters when specified process changes process group.
295  * We count the number of processes in each process group that "qualify"
296  * the group for terminal job control (those with a parent in a different
297  * process group of the same session).  If that count reaches zero, the
298  * process group becomes orphaned.  Check both the specified process'
299  * process group and that of its children.
300  * entering == 0 => p is leaving specified group.
301  * entering == 1 => p is entering specified group.
302  */
303 void
304 fixjobc(p, pgrp, entering)
305 	register struct proc *p;
306 	register struct pgrp *pgrp;
307 	int entering;
308 {
309 	register struct pgrp *hispgrp;
310 	register struct session *mysession = pgrp->pg_session;
311 
312 	/*
313 	 * Check p's parent to see whether p qualifies its own process
314 	 * group; if so, adjust count for p's process group.
315 	 */
316 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
317 	    hispgrp->pg_session == mysession) {
318 		if (entering)
319 			pgrp->pg_jobc++;
320 		else if (--pgrp->pg_jobc == 0)
321 			orphanpg(pgrp);
322 	}
323 
324 	/*
325 	 * Check this process' children to see whether they qualify
326 	 * their process groups; if so, adjust counts for children's
327 	 * process groups.
328 	 */
329 	LIST_FOREACH(p, &p->p_children, p_sibling)
330 		if ((hispgrp = p->p_pgrp) != pgrp &&
331 		    hispgrp->pg_session == mysession &&
332 		    P_ZOMBIE(p) == 0) {
333 			if (entering)
334 				hispgrp->pg_jobc++;
335 			else if (--hispgrp->pg_jobc == 0)
336 				orphanpg(hispgrp);
337 		}
338 }
339 
340 /*
341  * A process group has become orphaned;
342  * if there are any stopped processes in the group,
343  * hang-up all process in that group.
344  */
345 static void
346 orphanpg(pg)
347 	struct pgrp *pg;
348 {
349 	register struct proc *p;
350 
351 	LIST_FOREACH(p, &pg->pg_members, p_pglist) {
352 		if (p->p_stat == SSTOP) {
353 			LIST_FOREACH(p, &pg->pg_members, p_pglist) {
354 				psignal(p, SIGHUP);
355 				psignal(p, SIGCONT);
356 			}
357 			return;
358 		}
359 	}
360 }
361 
362 #ifdef DDB
363 void
364 proc_printit(struct proc *p, const char *modif, int (*pr)(const char *, ...))
365 {
366 	static const char *const pstat[] = {
367 		"idle", "run", "sleep", "stop", "zombie", "dead", "onproc"
368 	};
369 	char pstbuf[5];
370 	const char *pst = pstbuf;
371 
372 	if (p->p_stat < 1 || p->p_stat > sizeof(pstat) / sizeof(pstat[0]))
373 		snprintf(pstbuf, sizeof(pstbuf), "%d", p->p_stat);
374 	else
375 		pst = pstat[(int)p->p_stat - 1];
376 
377 	(*pr)("PROC (%s) pid=%d stat=%s flags=%b\n",
378 	    p->p_comm, p->p_pid, pst, p->p_flag, P_BITS);
379 	(*pr)("    pri=%u, usrpri=%u, nice=%d\n",
380 	    p->p_priority, p->p_usrpri, p->p_nice);
381 	(*pr)("    forw=%p, back=%p, list=%p,%p\n",
382 	    p->p_forw, p->p_back, p->p_list.le_next, p->p_list.le_prev);
383 	(*pr)("    user=%p, vmspace=%p\n",
384 	    p->p_addr, p->p_vmspace);
385 	(*pr)("    estcpu=%u, cpticks=%d, pctcpu=%u.%u%, swtime=%u\n",
386 	    p->p_estcpu, p->p_cpticks, p->p_pctcpu / 100, p->p_pctcpu % 100,
387 	    p->p_swtime);
388 	(*pr)("    user=%llu, sys=%llu, intr=%llu\n",
389 	    p->p_uticks, p->p_sticks, p->p_iticks);
390 }
391 #include <machine/db_machdep.h>
392 
393 #include <ddb/db_interface.h>
394 #include <ddb/db_output.h>
395 
396 void
397 db_show_all_procs(addr, haddr, count, modif)
398 	db_expr_t addr;
399 	int haddr;
400 	db_expr_t count;
401 	char *modif;
402 {
403 	char *mode;
404 	int doingzomb = 0;
405 	struct proc *p, *pp;
406 
407 	if (modif[0] == 0)
408 		modif[0] = 'n';			/* default == normal mode */
409 
410 	mode = "mawn";
411 	while (*mode && *mode != modif[0])
412 		mode++;
413 	if (*mode == 0 || *mode == 'm') {
414 		db_printf("usage: show all procs [/a] [/n] [/w]\n");
415 		db_printf("\t/a == show process address info\n");
416 		db_printf("\t/n == show normal process info [default]\n");
417 		db_printf("\t/w == show process wait/emul info\n");
418 		return;
419 	}
420 
421 	p = LIST_FIRST(&allproc);
422 
423 	switch (*mode) {
424 
425 	case 'a':
426 		db_printf("   PID  %-10s  %18s  %18s  %18s\n",
427 		    "COMMAND", "STRUCT PROC *", "UAREA *", "VMSPACE/VM_MAP");
428 		break;
429 	case 'n':
430 		db_printf("   PID  %5s  %5s  %5s  S  %10s  %-9s  %-16s\n",
431 		    "PPID", "PGRP", "UID", "FLAGS", "WAIT", "COMMAND");
432 		break;
433 	case 'w':
434 		db_printf("   PID  %-16s  %-8s  %18s  %s\n",
435 		    "COMMAND", "EMUL", "WAIT-CHANNEL", "WAIT-MSG");
436 		break;
437 	}
438 
439 	while (p != 0) {
440 		pp = p->p_pptr;
441 		if (p->p_stat) {
442 
443 			db_printf("%c%5d  ", p == curproc ? '*' : ' ',
444 				p->p_pid);
445 
446 			switch (*mode) {
447 
448 			case 'a':
449 				db_printf("%-10.10s  %18p  %18p  %18p\n",
450 				    p->p_comm, p, p->p_addr, p->p_vmspace);
451 				break;
452 
453 			case 'n':
454 				db_printf("%5d  %5d  %5d  %d  %#10x  "
455 				    "%-9.9s  %-16s\n",
456 				    pp ? pp->p_pid : -1, p->p_pgrp->pg_id,
457 				    p->p_cred->p_ruid, p->p_stat, p->p_flag,
458 				    (p->p_wchan && p->p_wmesg) ?
459 					p->p_wmesg : "", p->p_comm);
460 				break;
461 
462 			case 'w':
463 				db_printf("%-16s  %-8s  %18p  %s\n", p->p_comm,
464 				    p->p_emul->e_name, p->p_wchan,
465 				    (p->p_wchan && p->p_wmesg) ?
466 					p->p_wmesg : "");
467 				break;
468 
469 			}
470 		}
471 		p = LIST_NEXT(p, p_list);
472 		if (p == 0 && doingzomb == 0) {
473 			doingzomb = 1;
474 			p = LIST_FIRST(&zombproc);
475 		}
476 	}
477 }
478 #endif
479 
480 #ifdef DEBUG
481 void
482 pgrpdump()
483 {
484 	register struct pgrp *pgrp;
485 	register struct proc *p;
486 	register int i;
487 
488 	for (i = 0; i <= pgrphash; i++) {
489 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
490 			printf("\tindx %d\n", i);
491 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
492 				printf("\tpgrp %p, pgid %d, sess %p, sesscnt %d, mem %p\n",
493 				    pgrp, pgrp->pg_id, pgrp->pg_session,
494 				    pgrp->pg_session->s_count,
495 				    LIST_FIRST(&pgrp->pg_members));
496 				LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
497 					printf("\t\tpid %d addr %p pgrp %p\n",
498 					    p->p_pid, p, p->p_pgrp);
499 				}
500 			}
501 		}
502 	}
503 }
504 #endif /* DEBUG */
505