xref: /freebsd/sys/kern/kern_proc.c (revision a8445737e740901f5f2c8d24c12ef7fc8b00134e)
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  * $Id: kern_proc.c,v 1.36 1998/02/20 13:52:14 bde Exp $
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/tty.h>
44 #include <sys/signalvar.h>
45 #include <vm/vm.h>
46 #include <sys/lock.h>
47 #include <vm/pmap.h>
48 #include <vm/vm_map.h>
49 #include <sys/user.h>
50 #include <vm/vm_zone.h>
51 
52 static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
53 MALLOC_DEFINE(M_SESSION, "session", "session header");
54 static MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
55 MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
56 
57 struct prochd qs[NQS];		/* as good a place as any... */
58 struct prochd rtqs[NQS];	/* Space for REALTIME queues too */
59 struct prochd idqs[NQS];	/* Space for IDLE queues too */
60 
61 static void pgdelete	__P((struct pgrp *));
62 
63 /*
64  * Structure associated with user cacheing.
65  */
66 struct uidinfo {
67 	LIST_ENTRY(uidinfo) ui_hash;
68 	uid_t	ui_uid;
69 	long	ui_proccnt;
70 };
71 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
72 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
73 static u_long uihash;		/* size of hash table - 1 */
74 
75 static void	orphanpg __P((struct pgrp *pg));
76 
77 /*
78  * Other process lists
79  */
80 struct pidhashhead *pidhashtbl;
81 u_long pidhash;
82 struct pgrphashhead *pgrphashtbl;
83 u_long pgrphash;
84 struct proclist allproc;
85 struct proclist zombproc;
86 vm_zone_t proc_zone;
87 
88 /*
89  * Initialize global process hashing structures.
90  */
91 void
92 procinit()
93 {
94 
95 	LIST_INIT(&allproc);
96 	LIST_INIT(&zombproc);
97 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
98 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
99 	uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
100 	proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
101 }
102 
103 /*
104  * Change the count associated with number of processes
105  * a given user is using.
106  */
107 int
108 chgproccnt(uid, diff)
109 	uid_t	uid;
110 	int	diff;
111 {
112 	register struct uidinfo *uip;
113 	register struct uihashhead *uipp;
114 
115 	uipp = UIHASH(uid);
116 	for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next)
117 		if (uip->ui_uid == uid)
118 			break;
119 	if (uip) {
120 		uip->ui_proccnt += diff;
121 		if (uip->ui_proccnt > 0)
122 			return (uip->ui_proccnt);
123 		if (uip->ui_proccnt < 0)
124 			panic("chgproccnt: procs < 0");
125 		LIST_REMOVE(uip, ui_hash);
126 		FREE(uip, M_PROC);
127 		return (0);
128 	}
129 	if (diff <= 0) {
130 		if (diff == 0)
131 			return(0);
132 		panic("chgproccnt: lost user");
133 	}
134 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
135 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
136 	uip->ui_uid = uid;
137 	uip->ui_proccnt = diff;
138 	return (diff);
139 }
140 
141 /*
142  * Is p an inferior of the current process?
143  */
144 int
145 inferior(p)
146 	register struct proc *p;
147 {
148 
149 	for (; p != curproc; p = p->p_pptr)
150 		if (p->p_pid == 0)
151 			return (0);
152 	return (1);
153 }
154 
155 /*
156  * Locate a process by number
157  */
158 struct proc *
159 pfind(pid)
160 	register pid_t pid;
161 {
162 	register struct proc *p;
163 
164 	for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next)
165 		if (p->p_pid == pid)
166 			return (p);
167 	return (NULL);
168 }
169 
170 /*
171  * Locate a process group by number
172  */
173 struct pgrp *
174 pgfind(pgid)
175 	register pid_t pgid;
176 {
177 	register struct pgrp *pgrp;
178 
179 	for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0;
180 	     pgrp = pgrp->pg_hash.le_next)
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 		MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
214 		    M_WAITOK);
215 		if ((np = pfind(savepid)) == NULL || np != p)
216 			return (ESRCH);
217 		if (mksess) {
218 			register struct session *sess;
219 
220 			/*
221 			 * new session
222 			 */
223 			MALLOC(sess, struct session *, sizeof(struct session),
224 			    M_SESSION, M_WAITOK);
225 			sess->s_leader = p;
226 			sess->s_count = 1;
227 			sess->s_ttyvp = NULL;
228 			sess->s_ttyp = NULL;
229 			bcopy(p->p_session->s_login, sess->s_login,
230 			    sizeof(sess->s_login));
231 			p->p_flag &= ~P_CONTROLT;
232 			pgrp->pg_session = sess;
233 #ifdef DIAGNOSTIC
234 			if (p != curproc)
235 				panic("enterpgrp: mksession and p != curproc");
236 #endif
237 		} else {
238 			pgrp->pg_session = p->p_session;
239 			pgrp->pg_session->s_count++;
240 		}
241 		pgrp->pg_id = pgid;
242 		LIST_INIT(&pgrp->pg_members);
243 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
244 		pgrp->pg_jobc = 0;
245 	} else if (pgrp == p->p_pgrp)
246 		return (0);
247 
248 	/*
249 	 * Adjust eligibility of affected pgrps to participate in job control.
250 	 * Increment eligibility counts before decrementing, otherwise we
251 	 * could reach 0 spuriously during the first call.
252 	 */
253 	fixjobc(p, pgrp, 1);
254 	fixjobc(p, p->p_pgrp, 0);
255 
256 	LIST_REMOVE(p, p_pglist);
257 	if (p->p_pgrp->pg_members.lh_first == 0)
258 		pgdelete(p->p_pgrp);
259 	p->p_pgrp = pgrp;
260 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
261 	return (0);
262 }
263 
264 /*
265  * remove process from process group
266  */
267 int
268 leavepgrp(p)
269 	register struct proc *p;
270 {
271 
272 	LIST_REMOVE(p, p_pglist);
273 	if (p->p_pgrp->pg_members.lh_first == 0)
274 		pgdelete(p->p_pgrp);
275 	p->p_pgrp = 0;
276 	return (0);
277 }
278 
279 /*
280  * delete a process group
281  */
282 static void
283 pgdelete(pgrp)
284 	register struct pgrp *pgrp;
285 {
286 
287 	if (pgrp->pg_session->s_ttyp != NULL &&
288 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
289 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
290 	LIST_REMOVE(pgrp, pg_hash);
291 	if (--pgrp->pg_session->s_count == 0)
292 		FREE(pgrp->pg_session, M_SESSION);
293 	FREE(pgrp, M_PGRP);
294 }
295 
296 /*
297  * Adjust pgrp jobc counters when specified process changes process group.
298  * We count the number of processes in each process group that "qualify"
299  * the group for terminal job control (those with a parent in a different
300  * process group of the same session).  If that count reaches zero, the
301  * process group becomes orphaned.  Check both the specified process'
302  * process group and that of its children.
303  * entering == 0 => p is leaving specified group.
304  * entering == 1 => p is entering specified group.
305  */
306 void
307 fixjobc(p, pgrp, entering)
308 	register struct proc *p;
309 	register struct pgrp *pgrp;
310 	int entering;
311 {
312 	register struct pgrp *hispgrp;
313 	register struct session *mysession = pgrp->pg_session;
314 
315 	/*
316 	 * Check p's parent to see whether p qualifies its own process
317 	 * group; if so, adjust count for p's process group.
318 	 */
319 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
320 	    hispgrp->pg_session == mysession)
321 		if (entering)
322 			pgrp->pg_jobc++;
323 		else if (--pgrp->pg_jobc == 0)
324 			orphanpg(pgrp);
325 
326 	/*
327 	 * Check this process' children to see whether they qualify
328 	 * their process groups; if so, adjust counts for children's
329 	 * process groups.
330 	 */
331 	for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next)
332 		if ((hispgrp = p->p_pgrp) != pgrp &&
333 		    hispgrp->pg_session == mysession &&
334 		    p->p_stat != SZOMB)
335 			if (entering)
336 				hispgrp->pg_jobc++;
337 			else if (--hispgrp->pg_jobc == 0)
338 				orphanpg(hispgrp);
339 }
340 
341 /*
342  * A process group has become orphaned;
343  * if there are any stopped processes in the group,
344  * hang-up all process in that group.
345  */
346 static void
347 orphanpg(pg)
348 	struct pgrp *pg;
349 {
350 	register struct proc *p;
351 
352 	for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) {
353 		if (p->p_stat == SSTOP) {
354 			for (p = pg->pg_members.lh_first; p != 0;
355 			    p = p->p_pglist.le_next) {
356 				psignal(p, SIGHUP);
357 				psignal(p, SIGCONT);
358 			}
359 			return;
360 		}
361 	}
362 }
363 
364 #include "opt_ddb.h"
365 #ifdef DDB
366 #include <ddb/ddb.h>
367 
368 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
369 {
370 	register struct pgrp *pgrp;
371 	register struct proc *p;
372 	register int i;
373 
374 	for (i = 0; i <= pgrphash; i++) {
375 		if (pgrp = pgrphashtbl[i].lh_first) {
376 			printf("\tindx %d\n", i);
377 			for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) {
378 				printf(
379 			"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
380 				    (void *)pgrp, (long)pgrp->pg_id,
381 				    (void *)pgrp->pg_session,
382 				    pgrp->pg_session->s_count,
383 				    (void *)pgrp->pg_members.lh_first);
384 				for (p = pgrp->pg_members.lh_first; p != 0;
385 				    p = p->p_pglist.le_next) {
386 					printf("\t\tpid %ld addr %p pgrp %p\n",
387 					    (long)p->p_pid, (void *)p,
388 					    (void *)p->p_pgrp);
389 				}
390 			}
391 		}
392 	}
393 }
394 #endif /* DDB */
395 
396 /*
397  * Fill in an eproc structure for the specified process.
398  */
399 void
400 fill_eproc(p, ep)
401 	register struct proc *p;
402 	register struct eproc *ep;
403 {
404 	register struct tty *tp;
405 
406 	bzero(ep, sizeof(*ep));
407 
408 	ep->e_paddr = p;
409 	if (p->p_cred) {
410 		ep->e_pcred = *p->p_cred;
411 		if (p->p_ucred)
412 			ep->e_ucred = *p->p_ucred;
413 	}
414 	if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
415 		register struct vmspace *vm = p->p_vmspace;
416 
417 #ifdef pmap_resident_count
418 		ep->e_vm.vm_rssize = pmap_resident_count(&vm->vm_pmap); /*XXX*/
419 #else
420 		ep->e_vm.vm_rssize = vm->vm_rssize;
421 #endif
422 		ep->e_vm.vm_tsize = vm->vm_tsize;
423 		ep->e_vm.vm_dsize = vm->vm_dsize;
424 		ep->e_vm.vm_ssize = vm->vm_ssize;
425 		ep->e_vm.vm_taddr = vm->vm_taddr;
426 		ep->e_vm.vm_daddr = vm->vm_daddr;
427 		ep->e_vm.vm_minsaddr = vm->vm_minsaddr;
428 		ep->e_vm.vm_maxsaddr = vm->vm_maxsaddr;
429 		ep->e_vm.vm_map = vm->vm_map;
430 #ifndef sparc
431 		ep->e_vm.vm_pmap = vm->vm_pmap;
432 #endif
433 	}
434 	if (p->p_pptr)
435 		ep->e_ppid = p->p_pptr->p_pid;
436 	if (p->p_pgrp) {
437 		ep->e_pgid = p->p_pgrp->pg_id;
438 		ep->e_jobc = p->p_pgrp->pg_jobc;
439 		ep->e_sess = p->p_pgrp->pg_session;
440 
441 		if (ep->e_sess) {
442 			bcopy(ep->e_sess->s_login, ep->e_login, sizeof(ep->e_login));
443 			if (ep->e_sess->s_ttyvp)
444 				ep->e_flag = EPROC_CTTY;
445 			if (p->p_session && SESS_LEADER(p))
446 				ep->e_flag |= EPROC_SLEADER;
447 		}
448 	}
449 	if ((p->p_flag & P_CONTROLT) &&
450 	    (ep->e_sess != NULL) &&
451 	    ((tp = ep->e_sess->s_ttyp) != NULL)) {
452 		ep->e_tdev = tp->t_dev;
453 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
454 		ep->e_tsess = tp->t_session;
455 	} else
456 		ep->e_tdev = NODEV;
457 	if (p->p_wmesg) {
458 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
459 		ep->e_wmesg[WMESGLEN] = 0;
460 	}
461 }
462 
463 static struct proc *
464 zpfind(pid_t pid)
465 {
466 	struct proc *p;
467 
468 	for (p = zombproc.lh_first; p != 0; p = p->p_list.le_next)
469 		if (p->p_pid == pid)
470 			return (p);
471 	return (NULL);
472 }
473 
474 
475 static int
476 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
477 {
478 	struct eproc eproc;
479 	int error;
480 	pid_t pid = p->p_pid;
481 
482 	fill_eproc(p, &eproc);
483 	error = SYSCTL_OUT(req,(caddr_t)p, sizeof(struct proc));
484 	if (error)
485 		return (error);
486 	error = SYSCTL_OUT(req,(caddr_t)&eproc, sizeof(eproc));
487 	if (error)
488 		return (error);
489 	if (!doingzomb && pid && (pfind(pid) != p))
490 		return EAGAIN;
491 	if (doingzomb && zpfind(pid) != p)
492 		return EAGAIN;
493 	return (0);
494 }
495 
496 static int
497 sysctl_kern_proc SYSCTL_HANDLER_ARGS
498 {
499 	int *name = (int*) arg1;
500 	u_int namelen = arg2;
501 	struct proc *p;
502 	int doingzomb;
503 	int error = 0;
504 
505 	if (oidp->oid_number == KERN_PROC_PID) {
506 		if (namelen != 1)
507 			return (EINVAL);
508 		p = pfind((pid_t)name[0]);
509 		if (!p)
510 			return (0);
511 		error = sysctl_out_proc(p, req, 0);
512 		return (error);
513 	}
514 	if (oidp->oid_number == KERN_PROC_ALL && !namelen)
515 		;
516 	else if (oidp->oid_number != KERN_PROC_ALL && namelen == 1)
517 		;
518 	else
519 		return (EINVAL);
520 
521 	if (!req->oldptr) {
522 		/* overestimate by 5 procs */
523 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
524 		if (error)
525 			return (error);
526 	}
527 	for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
528 		if (!doingzomb)
529 			p = allproc.lh_first;
530 		else
531 			p = zombproc.lh_first;
532 		for (; p != 0; p = p->p_list.le_next) {
533 			/*
534 			 * Skip embryonic processes.
535 			 */
536 			if (p->p_stat == SIDL)
537 				continue;
538 			/*
539 			 * TODO - make more efficient (see notes below).
540 			 * do by session.
541 			 */
542 			switch (oidp->oid_number) {
543 
544 			case KERN_PROC_PGRP:
545 				/* could do this by traversing pgrp */
546 				if (p->p_pgrp == NULL ||
547 				    p->p_pgrp->pg_id != (pid_t)name[0])
548 					continue;
549 				break;
550 
551 			case KERN_PROC_TTY:
552 				if ((p->p_flag & P_CONTROLT) == 0 ||
553 				    p->p_session == NULL ||
554 				    p->p_session->s_ttyp == NULL ||
555 				    p->p_session->s_ttyp->t_dev != (dev_t)name[0])
556 					continue;
557 				break;
558 
559 			case KERN_PROC_UID:
560 				if (p->p_ucred == NULL ||
561 				    p->p_ucred->cr_uid != (uid_t)name[0])
562 					continue;
563 				break;
564 
565 			case KERN_PROC_RUID:
566 				if (p->p_ucred == NULL ||
567 				    p->p_cred->p_ruid != (uid_t)name[0])
568 					continue;
569 				break;
570 			}
571 
572 			error = sysctl_out_proc(p, req, doingzomb);
573 			if (error)
574 				return (error);
575 		}
576 	}
577 	return (0);
578 }
579 
580 
581 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
582 
583 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
584 	0, 0, sysctl_kern_proc, "S,proc", "");
585 
586 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
587 	sysctl_kern_proc, "Process table");
588 
589 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
590 	sysctl_kern_proc, "Process table");
591 
592 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
593 	sysctl_kern_proc, "Process table");
594 
595 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
596 	sysctl_kern_proc, "Process table");
597 
598 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
599 	sysctl_kern_proc, "Process table");
600