xref: /freebsd/sys/kern/kern_proc.c (revision 4cf49a43559ed9fdad601bdcccd2c55963008675) 
1 /*
2  * Copyright (c) 1982, 1986, 1989, 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)kern_proc.c	8.7 (Berkeley) 2/14/95
34  * $FreeBSD$
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/sysctl.h>
41 #include <sys/proc.h>
42 #include <sys/malloc.h>
43 #include <sys/filedesc.h>
44 #include <sys/tty.h>
45 #include <sys/signalvar.h>
46 #include <vm/vm.h>
47 #include <sys/lock.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_map.h>
50 #include <sys/user.h>
51 #include <vm/vm_zone.h>
52 
53 static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
54 MALLOC_DEFINE(M_SESSION, "session", "session header");
55 static MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
56 MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
57 
58 static void pgdelete	__P((struct pgrp *));
59 
60 /*
61  * Structure associated with user cacheing.
62  */
63 struct uidinfo {
64 	LIST_ENTRY(uidinfo) ui_hash;
65 	uid_t	ui_uid;
66 	long	ui_proccnt;
67 	rlim_t	ui_sbsize;
68 };
69 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
70 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
71 static u_long uihash;		/* size of hash table - 1 */
72 
73 static void	orphanpg __P((struct pgrp *pg));
74 
75 /*
76  * Other process lists
77  */
78 struct pidhashhead *pidhashtbl;
79 u_long pidhash;
80 struct pgrphashhead *pgrphashtbl;
81 u_long pgrphash;
82 struct proclist allproc;
83 struct proclist zombproc;
84 vm_zone_t proc_zone;
85 
86 /*
87  * Initialize global process hashing structures.
88  */
89 void
90 procinit()
91 {
92 
93 	LIST_INIT(&allproc);
94 	LIST_INIT(&zombproc);
95 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
96 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
97 	uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
98 	proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
99 }
100 
101 /*
102  * Change the count associated with number of processes
103  * a given user is using.
104  */
105 int
106 chgproccnt(uid, diff)
107 	uid_t	uid;
108 	int	diff;
109 {
110 	register struct uidinfo *uip;
111 	register struct uihashhead *uipp;
112 
113 	uipp = UIHASH(uid);
114 	for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next)
115 		if (uip->ui_uid == uid)
116 			break;
117 	if (uip) {
118 		uip->ui_proccnt += diff;
119 		if (uip->ui_proccnt < 0)
120 			panic("chgproccnt: procs < 0");
121 		if (uip->ui_proccnt > 0 || uip->ui_sbsize > 0)
122 			return (uip->ui_proccnt);
123 		LIST_REMOVE(uip, ui_hash);
124 		FREE(uip, M_PROC);
125 		return (0);
126 	}
127 	if (diff <= 0) {
128 		if (diff == 0)
129 			return(0);
130 		panic("chgproccnt: lost user");
131 	}
132 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
133 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
134 	uip->ui_uid = uid;
135 	uip->ui_proccnt = diff;
136 	uip->ui_sbsize = 0;
137 	return (diff);
138 }
139 
140 /*
141  * Change the total socket buffer size a user has used.
142  */
143 rlim_t
144 chgsbsize(uid, diff)
145 	uid_t	uid;
146 	rlim_t	diff;
147 {
148 	register struct uidinfo *uip;
149 	register struct uihashhead *uipp;
150 
151 	uipp = UIHASH(uid);
152 	for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next)
153 		if (uip->ui_uid == uid)
154 			break;
155 	if (diff <= 0) {
156 		if (diff == 0)
157 			return (uip ? uip->ui_sbsize : 0);
158 		KASSERT(uip != NULL, ("uidinfo (%d) gone", uid));
159 	}
160 	if (uip) {
161 		uip->ui_sbsize += diff;
162 		KASSERT(uip->ui_sbsize >= 0, ("ui_sbsize (%d) < 0", uid));
163 		if (uip->ui_sbsize == 0 && uip->ui_proccnt == 0) {
164 			LIST_REMOVE(uip, ui_hash);
165 			FREE(uip, M_PROC);
166 			return (0);
167 		}
168 		return (uip->ui_sbsize);
169 	}
170 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
171 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
172 	uip->ui_uid = uid;
173 	uip->ui_proccnt = 0;
174 	uip->ui_sbsize = diff;
175 	return (diff);
176 }
177 
178 /*
179  * Is p an inferior of the current process?
180  */
181 int
182 inferior(p)
183 	register struct proc *p;
184 {
185 
186 	for (; p != curproc; p = p->p_pptr)
187 		if (p->p_pid == 0)
188 			return (0);
189 	return (1);
190 }
191 
192 /*
193  * Locate a process by number
194  */
195 struct proc *
196 pfind(pid)
197 	register pid_t pid;
198 {
199 	register struct proc *p;
200 
201 	for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next)
202 		if (p->p_pid == pid)
203 			return (p);
204 	return (NULL);
205 }
206 
207 /*
208  * Locate a process group by number
209  */
210 struct pgrp *
211 pgfind(pgid)
212 	register pid_t pgid;
213 {
214 	register struct pgrp *pgrp;
215 
216 	for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0;
217 	     pgrp = pgrp->pg_hash.le_next)
218 		if (pgrp->pg_id == pgid)
219 			return (pgrp);
220 	return (NULL);
221 }
222 
223 /*
224  * Move p to a new or existing process group (and session)
225  */
226 int
227 enterpgrp(p, pgid, mksess)
228 	register struct proc *p;
229 	pid_t pgid;
230 	int mksess;
231 {
232 	register struct pgrp *pgrp = pgfind(pgid);
233 
234 	KASSERT(pgrp == NULL || !mksess,
235 	    ("enterpgrp: setsid into non-empty pgrp"));
236 	KASSERT(!SESS_LEADER(p),
237 	    ("enterpgrp: session leader attempted setpgrp"));
238 
239 	if (pgrp == NULL) {
240 		pid_t savepid = p->p_pid;
241 		struct proc *np;
242 		/*
243 		 * new process group
244 		 */
245 		KASSERT(p->p_pid == pgid,
246 		    ("enterpgrp: new pgrp and pid != pgid"));
247 		MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
248 		    M_WAITOK);
249 		if ((np = pfind(savepid)) == NULL || np != p)
250 			return (ESRCH);
251 		if (mksess) {
252 			register struct session *sess;
253 
254 			/*
255 			 * new session
256 			 */
257 			MALLOC(sess, struct session *, sizeof(struct session),
258 			    M_SESSION, M_WAITOK);
259 			sess->s_leader = p;
260 			sess->s_sid = p->p_pid;
261 			sess->s_count = 1;
262 			sess->s_ttyvp = NULL;
263 			sess->s_ttyp = NULL;
264 			bcopy(p->p_session->s_login, sess->s_login,
265 			    sizeof(sess->s_login));
266 			p->p_flag &= ~P_CONTROLT;
267 			pgrp->pg_session = sess;
268 			KASSERT(p == curproc,
269 			    ("enterpgrp: mksession and p != curproc"));
270 		} else {
271 			pgrp->pg_session = p->p_session;
272 			pgrp->pg_session->s_count++;
273 		}
274 		pgrp->pg_id = pgid;
275 		LIST_INIT(&pgrp->pg_members);
276 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
277 		pgrp->pg_jobc = 0;
278 		SLIST_INIT(&pgrp->pg_sigiolst);
279 	} else if (pgrp == p->p_pgrp)
280 		return (0);
281 
282 	/*
283 	 * Adjust eligibility of affected pgrps to participate in job control.
284 	 * Increment eligibility counts before decrementing, otherwise we
285 	 * could reach 0 spuriously during the first call.
286 	 */
287 	fixjobc(p, pgrp, 1);
288 	fixjobc(p, p->p_pgrp, 0);
289 
290 	LIST_REMOVE(p, p_pglist);
291 	if (p->p_pgrp->pg_members.lh_first == 0)
292 		pgdelete(p->p_pgrp);
293 	p->p_pgrp = pgrp;
294 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
295 	return (0);
296 }
297 
298 /*
299  * remove process from process group
300  */
301 int
302 leavepgrp(p)
303 	register struct proc *p;
304 {
305 
306 	LIST_REMOVE(p, p_pglist);
307 	if (p->p_pgrp->pg_members.lh_first == 0)
308 		pgdelete(p->p_pgrp);
309 	p->p_pgrp = 0;
310 	return (0);
311 }
312 
313 /*
314  * delete a process group
315  */
316 static void
317 pgdelete(pgrp)
318 	register struct pgrp *pgrp;
319 {
320 
321 	/*
322 	 * Reset any sigio structures pointing to us as a result of
323 	 * F_SETOWN with our pgid.
324 	 */
325 	funsetownlst(&pgrp->pg_sigiolst);
326 
327 	if (pgrp->pg_session->s_ttyp != NULL &&
328 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
329 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
330 	LIST_REMOVE(pgrp, pg_hash);
331 	if (--pgrp->pg_session->s_count == 0)
332 		FREE(pgrp->pg_session, M_SESSION);
333 	FREE(pgrp, M_PGRP);
334 }
335 
336 /*
337  * Adjust pgrp jobc counters when specified process changes process group.
338  * We count the number of processes in each process group that "qualify"
339  * the group for terminal job control (those with a parent in a different
340  * process group of the same session).  If that count reaches zero, the
341  * process group becomes orphaned.  Check both the specified process'
342  * process group and that of its children.
343  * entering == 0 => p is leaving specified group.
344  * entering == 1 => p is entering specified group.
345  */
346 void
347 fixjobc(p, pgrp, entering)
348 	register struct proc *p;
349 	register struct pgrp *pgrp;
350 	int entering;
351 {
352 	register struct pgrp *hispgrp;
353 	register struct session *mysession = pgrp->pg_session;
354 
355 	/*
356 	 * Check p's parent to see whether p qualifies its own process
357 	 * group; if so, adjust count for p's process group.
358 	 */
359 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
360 	    hispgrp->pg_session == mysession) {
361 		if (entering)
362 			pgrp->pg_jobc++;
363 		else if (--pgrp->pg_jobc == 0)
364 			orphanpg(pgrp);
365 	}
366 
367 	/*
368 	 * Check this process' children to see whether they qualify
369 	 * their process groups; if so, adjust counts for children's
370 	 * process groups.
371 	 */
372 	for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next)
373 		if ((hispgrp = p->p_pgrp) != pgrp &&
374 		    hispgrp->pg_session == mysession &&
375 		    p->p_stat != SZOMB) {
376 			if (entering)
377 				hispgrp->pg_jobc++;
378 			else if (--hispgrp->pg_jobc == 0)
379 				orphanpg(hispgrp);
380 		}
381 }
382 
383 /*
384  * A process group has become orphaned;
385  * if there are any stopped processes in the group,
386  * hang-up all process in that group.
387  */
388 static void
389 orphanpg(pg)
390 	struct pgrp *pg;
391 {
392 	register struct proc *p;
393 
394 	for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) {
395 		if (p->p_stat == SSTOP) {
396 			for (p = pg->pg_members.lh_first; p != 0;
397 			    p = p->p_pglist.le_next) {
398 				psignal(p, SIGHUP);
399 				psignal(p, SIGCONT);
400 			}
401 			return;
402 		}
403 	}
404 }
405 
406 #include "opt_ddb.h"
407 #ifdef DDB
408 #include <ddb/ddb.h>
409 
410 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
411 {
412 	register struct pgrp *pgrp;
413 	register struct proc *p;
414 	register int i;
415 
416 	for (i = 0; i <= pgrphash; i++) {
417 		if ((pgrp = pgrphashtbl[i].lh_first) != NULL) {
418 			printf("\tindx %d\n", i);
419 			for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) {
420 				printf(
421 			"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
422 				    (void *)pgrp, (long)pgrp->pg_id,
423 				    (void *)pgrp->pg_session,
424 				    pgrp->pg_session->s_count,
425 				    (void *)pgrp->pg_members.lh_first);
426 				for (p = pgrp->pg_members.lh_first; p != 0;
427 				    p = p->p_pglist.le_next) {
428 					printf("\t\tpid %ld addr %p pgrp %p\n",
429 					    (long)p->p_pid, (void *)p,
430 					    (void *)p->p_pgrp);
431 				}
432 			}
433 		}
434 	}
435 }
436 #endif /* DDB */
437 
438 /*
439  * Fill in an eproc structure for the specified process.
440  */
441 void
442 fill_eproc(p, ep)
443 	register struct proc *p;
444 	register struct eproc *ep;
445 {
446 	register struct tty *tp;
447 
448 	bzero(ep, sizeof(*ep));
449 
450 	ep->e_paddr = p;
451 	if (p->p_cred) {
452 		ep->e_pcred = *p->p_cred;
453 		if (p->p_ucred)
454 			ep->e_ucred = *p->p_ucred;
455 	}
456 	if (p->p_procsig){
457 		ep->e_procsig = *p->p_procsig;
458 	}
459 	if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
460 		register struct vmspace *vm = p->p_vmspace;
461 		ep->e_vm = *vm;
462 		ep->e_vm.vm_rssize = vmspace_resident_count(vm); /*XXX*/
463 	}
464 	if (p->p_pptr)
465 		ep->e_ppid = p->p_pptr->p_pid;
466 	if (p->p_pgrp) {
467 		ep->e_pgid = p->p_pgrp->pg_id;
468 		ep->e_jobc = p->p_pgrp->pg_jobc;
469 		ep->e_sess = p->p_pgrp->pg_session;
470 
471 		if (ep->e_sess) {
472 			bcopy(ep->e_sess->s_login, ep->e_login, sizeof(ep->e_login));
473 			if (ep->e_sess->s_ttyvp)
474 				ep->e_flag = EPROC_CTTY;
475 			if (p->p_session && SESS_LEADER(p))
476 				ep->e_flag |= EPROC_SLEADER;
477 		}
478 	}
479 	if ((p->p_flag & P_CONTROLT) &&
480 	    (ep->e_sess != NULL) &&
481 	    ((tp = ep->e_sess->s_ttyp) != NULL)) {
482 		ep->e_tdev = dev2udev(tp->t_dev);
483 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
484 		ep->e_tsess = tp->t_session;
485 	} else
486 		ep->e_tdev = NOUDEV;
487 	if (p->p_wmesg) {
488 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
489 		ep->e_wmesg[WMESGLEN] = 0;
490 	}
491 }
492 
493 static struct proc *
494 zpfind(pid_t pid)
495 {
496 	struct proc *p;
497 
498 	for (p = zombproc.lh_first; p != 0; p = p->p_list.le_next)
499 		if (p->p_pid == pid)
500 			return (p);
501 	return (NULL);
502 }
503 
504 
505 static int
506 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
507 {
508 	struct eproc eproc;
509 	int error;
510 	pid_t pid = p->p_pid;
511 
512 	fill_eproc(p, &eproc);
513 	error = SYSCTL_OUT(req,(caddr_t)p, sizeof(struct proc));
514 	if (error)
515 		return (error);
516 	error = SYSCTL_OUT(req,(caddr_t)&eproc, sizeof(eproc));
517 	if (error)
518 		return (error);
519 	if (!doingzomb && pid && (pfind(pid) != p))
520 		return EAGAIN;
521 	if (doingzomb && zpfind(pid) != p)
522 		return EAGAIN;
523 	return (0);
524 }
525 
526 static int
527 sysctl_kern_proc SYSCTL_HANDLER_ARGS
528 {
529 	int *name = (int*) arg1;
530 	u_int namelen = arg2;
531 	struct proc *p;
532 	int doingzomb;
533 	int error = 0;
534 
535 	if (oidp->oid_number == KERN_PROC_PID) {
536 		if (namelen != 1)
537 			return (EINVAL);
538 		p = pfind((pid_t)name[0]);
539 		if (!p)
540 			return (0);
541 		if (!PRISON_CHECK(curproc, p))
542 			return (0);
543 		error = sysctl_out_proc(p, req, 0);
544 		return (error);
545 	}
546 	if (oidp->oid_number == KERN_PROC_ALL && !namelen)
547 		;
548 	else if (oidp->oid_number != KERN_PROC_ALL && namelen == 1)
549 		;
550 	else
551 		return (EINVAL);
552 
553 	if (!req->oldptr) {
554 		/* overestimate by 5 procs */
555 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
556 		if (error)
557 			return (error);
558 	}
559 	for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
560 		if (!doingzomb)
561 			p = allproc.lh_first;
562 		else
563 			p = zombproc.lh_first;
564 		for (; p != 0; p = p->p_list.le_next) {
565 			/*
566 			 * Skip embryonic processes.
567 			 */
568 			if (p->p_stat == SIDL)
569 				continue;
570 			/*
571 			 * TODO - make more efficient (see notes below).
572 			 * do by session.
573 			 */
574 			switch (oidp->oid_number) {
575 
576 			case KERN_PROC_PGRP:
577 				/* could do this by traversing pgrp */
578 				if (p->p_pgrp == NULL ||
579 				    p->p_pgrp->pg_id != (pid_t)name[0])
580 					continue;
581 				break;
582 
583 			case KERN_PROC_TTY:
584 				if ((p->p_flag & P_CONTROLT) == 0 ||
585 				    p->p_session == NULL ||
586 				    p->p_session->s_ttyp == NULL ||
587 				    dev2udev(p->p_session->s_ttyp->t_dev) !=
588 					(udev_t)name[0])
589 					continue;
590 				break;
591 
592 			case KERN_PROC_UID:
593 				if (p->p_ucred == NULL ||
594 				    p->p_ucred->cr_uid != (uid_t)name[0])
595 					continue;
596 				break;
597 
598 			case KERN_PROC_RUID:
599 				if (p->p_ucred == NULL ||
600 				    p->p_cred->p_ruid != (uid_t)name[0])
601 					continue;
602 				break;
603 			}
604 
605 			if (!PRISON_CHECK(curproc, p))
606 				continue;
607 
608 			error = sysctl_out_proc(p, req, doingzomb);
609 			if (error)
610 				return (error);
611 		}
612 	}
613 	return (0);
614 }
615 
616 
617 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
618 
619 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
620 	0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
621 
622 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
623 	sysctl_kern_proc, "Process table");
624 
625 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
626 	sysctl_kern_proc, "Process table");
627 
628 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
629 	sysctl_kern_proc, "Process table");
630 
631 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
632 	sysctl_kern_proc, "Process table");
633 
634 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
635 	sysctl_kern_proc, "Process table");
636