xref: /freebsd/sys/kern/kern_proc.c (revision 2ad872c5794e4c26fdf6ed219ad3f09ca0d5304a) 
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 1.41 1999/01/08 17:31:09 eivind 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/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 struct prochd qs[NQS];		/* as good a place as any... */
59 struct prochd rtqs[NQS];	/* Space for REALTIME queues too */
60 struct prochd idqs[NQS];	/* Space for IDLE queues too */
61 
62 static void pgdelete	__P((struct pgrp *));
63 
64 /*
65  * Structure associated with user cacheing.
66  */
67 struct uidinfo {
68 	LIST_ENTRY(uidinfo) ui_hash;
69 	uid_t	ui_uid;
70 	long	ui_proccnt;
71 };
72 #define	UIHASH(uid)	(&uihashtbl[(uid) & uihash])
73 static LIST_HEAD(uihashhead, uidinfo) *uihashtbl;
74 static u_long uihash;		/* size of hash table - 1 */
75 
76 static void	orphanpg __P((struct pgrp *pg));
77 
78 /*
79  * Other process lists
80  */
81 struct pidhashhead *pidhashtbl;
82 u_long pidhash;
83 struct pgrphashhead *pgrphashtbl;
84 u_long pgrphash;
85 struct proclist allproc;
86 struct proclist zombproc;
87 vm_zone_t proc_zone;
88 
89 /*
90  * Initialize global process hashing structures.
91  */
92 void
93 procinit()
94 {
95 
96 	LIST_INIT(&allproc);
97 	LIST_INIT(&zombproc);
98 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
99 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
100 	uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
101 	proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
102 }
103 
104 /*
105  * Change the count associated with number of processes
106  * a given user is using.
107  */
108 int
109 chgproccnt(uid, diff)
110 	uid_t	uid;
111 	int	diff;
112 {
113 	register struct uidinfo *uip;
114 	register struct uihashhead *uipp;
115 
116 	uipp = UIHASH(uid);
117 	for (uip = uipp->lh_first; uip != 0; uip = uip->ui_hash.le_next)
118 		if (uip->ui_uid == uid)
119 			break;
120 	if (uip) {
121 		uip->ui_proccnt += diff;
122 		if (uip->ui_proccnt > 0)
123 			return (uip->ui_proccnt);
124 		if (uip->ui_proccnt < 0)
125 			panic("chgproccnt: procs < 0");
126 		LIST_REMOVE(uip, ui_hash);
127 		FREE(uip, M_PROC);
128 		return (0);
129 	}
130 	if (diff <= 0) {
131 		if (diff == 0)
132 			return(0);
133 		panic("chgproccnt: lost user");
134 	}
135 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
136 	LIST_INSERT_HEAD(uipp, uip, ui_hash);
137 	uip->ui_uid = uid;
138 	uip->ui_proccnt = diff;
139 	return (diff);
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 	for (p = PIDHASH(pid)->lh_first; p != 0; p = p->p_hash.le_next)
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 	for (pgrp = PGRPHASH(pgid)->lh_first; pgrp != 0;
181 	     pgrp = pgrp->pg_hash.le_next)
182 		if (pgrp->pg_id == pgid)
183 			return (pgrp);
184 	return (NULL);
185 }
186 
187 /*
188  * Move p to a new or existing process group (and session)
189  */
190 int
191 enterpgrp(p, pgid, mksess)
192 	register struct proc *p;
193 	pid_t pgid;
194 	int mksess;
195 {
196 	register struct pgrp *pgrp = pgfind(pgid);
197 
198 	KASSERT(pgrp == NULL || !mksess,
199 	    ("enterpgrp: setsid into non-empty pgrp"));
200 	KASSERT(!SESS_LEADER(p),
201 	    ("enterpgrp: session leader attempted setpgrp"));
202 
203 	if (pgrp == NULL) {
204 		pid_t savepid = p->p_pid;
205 		struct proc *np;
206 		/*
207 		 * new process group
208 		 */
209 		KASSERT(p->p_pid == pgid,
210 		    ("enterpgrp: new pgrp and pid != pgid"));
211 		MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
212 		    M_WAITOK);
213 		if ((np = pfind(savepid)) == NULL || np != p)
214 			return (ESRCH);
215 		if (mksess) {
216 			register struct session *sess;
217 
218 			/*
219 			 * new session
220 			 */
221 			MALLOC(sess, struct session *, sizeof(struct session),
222 			    M_SESSION, M_WAITOK);
223 			sess->s_leader = p;
224 			sess->s_sid = p->p_pid;
225 			sess->s_count = 1;
226 			sess->s_ttyvp = NULL;
227 			sess->s_ttyp = NULL;
228 			bcopy(p->p_session->s_login, sess->s_login,
229 			    sizeof(sess->s_login));
230 			p->p_flag &= ~P_CONTROLT;
231 			pgrp->pg_session = sess;
232 			KASSERT(p == curproc,
233 			    ("enterpgrp: mksession and p != curproc"));
234 		} else {
235 			pgrp->pg_session = p->p_session;
236 			pgrp->pg_session->s_count++;
237 		}
238 		pgrp->pg_id = pgid;
239 		LIST_INIT(&pgrp->pg_members);
240 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
241 		pgrp->pg_jobc = 0;
242 		SLIST_INIT(&pgrp->pg_sigiolst);
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 (p->p_pgrp->pg_members.lh_first == 0)
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 (p->p_pgrp->pg_members.lh_first == 0)
272 		pgdelete(p->p_pgrp);
273 	p->p_pgrp = 0;
274 	return (0);
275 }
276 
277 /*
278  * delete a process group
279  */
280 static void
281 pgdelete(pgrp)
282 	register struct pgrp *pgrp;
283 {
284 
285 	/*
286 	 * Reset any sigio structures pointing to us as a result of
287 	 * F_SETOWN with our pgid.
288 	 */
289 	funsetownlst(&pgrp->pg_sigiolst);
290 
291 	if (pgrp->pg_session->s_ttyp != NULL &&
292 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
293 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
294 	LIST_REMOVE(pgrp, pg_hash);
295 	if (--pgrp->pg_session->s_count == 0)
296 		FREE(pgrp->pg_session, M_SESSION);
297 	FREE(pgrp, M_PGRP);
298 }
299 
300 /*
301  * Adjust pgrp jobc counters when specified process changes process group.
302  * We count the number of processes in each process group that "qualify"
303  * the group for terminal job control (those with a parent in a different
304  * process group of the same session).  If that count reaches zero, the
305  * process group becomes orphaned.  Check both the specified process'
306  * process group and that of its children.
307  * entering == 0 => p is leaving specified group.
308  * entering == 1 => p is entering specified group.
309  */
310 void
311 fixjobc(p, pgrp, entering)
312 	register struct proc *p;
313 	register struct pgrp *pgrp;
314 	int entering;
315 {
316 	register struct pgrp *hispgrp;
317 	register struct session *mysession = pgrp->pg_session;
318 
319 	/*
320 	 * Check p's parent to see whether p qualifies its own process
321 	 * group; if so, adjust count for p's process group.
322 	 */
323 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
324 	    hispgrp->pg_session == mysession)
325 		if (entering)
326 			pgrp->pg_jobc++;
327 		else if (--pgrp->pg_jobc == 0)
328 			orphanpg(pgrp);
329 
330 	/*
331 	 * Check this process' children to see whether they qualify
332 	 * their process groups; if so, adjust counts for children's
333 	 * process groups.
334 	 */
335 	for (p = p->p_children.lh_first; p != 0; p = p->p_sibling.le_next)
336 		if ((hispgrp = p->p_pgrp) != pgrp &&
337 		    hispgrp->pg_session == mysession &&
338 		    p->p_stat != SZOMB)
339 			if (entering)
340 				hispgrp->pg_jobc++;
341 			else if (--hispgrp->pg_jobc == 0)
342 				orphanpg(hispgrp);
343 }
344 
345 /*
346  * A process group has become orphaned;
347  * if there are any stopped processes in the group,
348  * hang-up all process in that group.
349  */
350 static void
351 orphanpg(pg)
352 	struct pgrp *pg;
353 {
354 	register struct proc *p;
355 
356 	for (p = pg->pg_members.lh_first; p != 0; p = p->p_pglist.le_next) {
357 		if (p->p_stat == SSTOP) {
358 			for (p = pg->pg_members.lh_first; p != 0;
359 			    p = p->p_pglist.le_next) {
360 				psignal(p, SIGHUP);
361 				psignal(p, SIGCONT);
362 			}
363 			return;
364 		}
365 	}
366 }
367 
368 #include "opt_ddb.h"
369 #ifdef DDB
370 #include <ddb/ddb.h>
371 
372 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
373 {
374 	register struct pgrp *pgrp;
375 	register struct proc *p;
376 	register int i;
377 
378 	for (i = 0; i <= pgrphash; i++) {
379 		if (pgrp = pgrphashtbl[i].lh_first) {
380 			printf("\tindx %d\n", i);
381 			for (; pgrp != 0; pgrp = pgrp->pg_hash.le_next) {
382 				printf(
383 			"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
384 				    (void *)pgrp, (long)pgrp->pg_id,
385 				    (void *)pgrp->pg_session,
386 				    pgrp->pg_session->s_count,
387 				    (void *)pgrp->pg_members.lh_first);
388 				for (p = pgrp->pg_members.lh_first; p != 0;
389 				    p = p->p_pglist.le_next) {
390 					printf("\t\tpid %ld addr %p pgrp %p\n",
391 					    (long)p->p_pid, (void *)p,
392 					    (void *)p->p_pgrp);
393 				}
394 			}
395 		}
396 	}
397 }
398 #endif /* DDB */
399 
400 /*
401  * Fill in an eproc structure for the specified process.
402  */
403 void
404 fill_eproc(p, ep)
405 	register struct proc *p;
406 	register struct eproc *ep;
407 {
408 	register struct tty *tp;
409 
410 	bzero(ep, sizeof(*ep));
411 
412 	ep->e_paddr = p;
413 	if (p->p_cred) {
414 		ep->e_pcred = *p->p_cred;
415 		if (p->p_ucred)
416 			ep->e_ucred = *p->p_ucred;
417 	}
418 	if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
419 		register struct vmspace *vm = p->p_vmspace;
420 
421 #ifdef pmap_resident_count
422 		ep->e_vm.vm_rssize = pmap_resident_count(&vm->vm_pmap); /*XXX*/
423 #else
424 		ep->e_vm.vm_rssize = vm->vm_rssize;
425 #endif
426 		ep->e_vm.vm_tsize = vm->vm_tsize;
427 		ep->e_vm.vm_dsize = vm->vm_dsize;
428 		ep->e_vm.vm_ssize = vm->vm_ssize;
429 		ep->e_vm.vm_taddr = vm->vm_taddr;
430 		ep->e_vm.vm_daddr = vm->vm_daddr;
431 		ep->e_vm.vm_minsaddr = vm->vm_minsaddr;
432 		ep->e_vm.vm_maxsaddr = vm->vm_maxsaddr;
433 		ep->e_vm.vm_map = vm->vm_map;
434 #ifndef sparc
435 		ep->e_vm.vm_pmap = vm->vm_pmap;
436 #endif
437 	}
438 	if (p->p_pptr)
439 		ep->e_ppid = p->p_pptr->p_pid;
440 	if (p->p_pgrp) {
441 		ep->e_pgid = p->p_pgrp->pg_id;
442 		ep->e_jobc = p->p_pgrp->pg_jobc;
443 		ep->e_sess = p->p_pgrp->pg_session;
444 
445 		if (ep->e_sess) {
446 			bcopy(ep->e_sess->s_login, ep->e_login, sizeof(ep->e_login));
447 			if (ep->e_sess->s_ttyvp)
448 				ep->e_flag = EPROC_CTTY;
449 			if (p->p_session && SESS_LEADER(p))
450 				ep->e_flag |= EPROC_SLEADER;
451 		}
452 	}
453 	if ((p->p_flag & P_CONTROLT) &&
454 	    (ep->e_sess != NULL) &&
455 	    ((tp = ep->e_sess->s_ttyp) != NULL)) {
456 		ep->e_tdev = tp->t_dev;
457 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
458 		ep->e_tsess = tp->t_session;
459 	} else
460 		ep->e_tdev = NODEV;
461 	if (p->p_wmesg) {
462 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
463 		ep->e_wmesg[WMESGLEN] = 0;
464 	}
465 }
466 
467 static struct proc *
468 zpfind(pid_t pid)
469 {
470 	struct proc *p;
471 
472 	for (p = zombproc.lh_first; p != 0; p = p->p_list.le_next)
473 		if (p->p_pid == pid)
474 			return (p);
475 	return (NULL);
476 }
477 
478 
479 static int
480 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
481 {
482 	struct eproc eproc;
483 	int error;
484 	pid_t pid = p->p_pid;
485 
486 	fill_eproc(p, &eproc);
487 	error = SYSCTL_OUT(req,(caddr_t)p, sizeof(struct proc));
488 	if (error)
489 		return (error);
490 	error = SYSCTL_OUT(req,(caddr_t)&eproc, sizeof(eproc));
491 	if (error)
492 		return (error);
493 	if (!doingzomb && pid && (pfind(pid) != p))
494 		return EAGAIN;
495 	if (doingzomb && zpfind(pid) != p)
496 		return EAGAIN;
497 	return (0);
498 }
499 
500 static int
501 sysctl_kern_proc SYSCTL_HANDLER_ARGS
502 {
503 	int *name = (int*) arg1;
504 	u_int namelen = arg2;
505 	struct proc *p;
506 	int doingzomb;
507 	int error = 0;
508 
509 	if (oidp->oid_number == KERN_PROC_PID) {
510 		if (namelen != 1)
511 			return (EINVAL);
512 		p = pfind((pid_t)name[0]);
513 		if (!p)
514 			return (0);
515 		error = sysctl_out_proc(p, req, 0);
516 		return (error);
517 	}
518 	if (oidp->oid_number == KERN_PROC_ALL && !namelen)
519 		;
520 	else if (oidp->oid_number != KERN_PROC_ALL && namelen == 1)
521 		;
522 	else
523 		return (EINVAL);
524 
525 	if (!req->oldptr) {
526 		/* overestimate by 5 procs */
527 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
528 		if (error)
529 			return (error);
530 	}
531 	for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
532 		if (!doingzomb)
533 			p = allproc.lh_first;
534 		else
535 			p = zombproc.lh_first;
536 		for (; p != 0; p = p->p_list.le_next) {
537 			/*
538 			 * Skip embryonic processes.
539 			 */
540 			if (p->p_stat == SIDL)
541 				continue;
542 			/*
543 			 * TODO - make more efficient (see notes below).
544 			 * do by session.
545 			 */
546 			switch (oidp->oid_number) {
547 
548 			case KERN_PROC_PGRP:
549 				/* could do this by traversing pgrp */
550 				if (p->p_pgrp == NULL ||
551 				    p->p_pgrp->pg_id != (pid_t)name[0])
552 					continue;
553 				break;
554 
555 			case KERN_PROC_TTY:
556 				if ((p->p_flag & P_CONTROLT) == 0 ||
557 				    p->p_session == NULL ||
558 				    p->p_session->s_ttyp == NULL ||
559 				    p->p_session->s_ttyp->t_dev != (dev_t)name[0])
560 					continue;
561 				break;
562 
563 			case KERN_PROC_UID:
564 				if (p->p_ucred == NULL ||
565 				    p->p_ucred->cr_uid != (uid_t)name[0])
566 					continue;
567 				break;
568 
569 			case KERN_PROC_RUID:
570 				if (p->p_ucred == NULL ||
571 				    p->p_cred->p_ruid != (uid_t)name[0])
572 					continue;
573 				break;
574 			}
575 
576 			error = sysctl_out_proc(p, req, doingzomb);
577 			if (error)
578 				return (error);
579 		}
580 	}
581 	return (0);
582 }
583 
584 
585 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
586 
587 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
588 	0, 0, sysctl_kern_proc, "S,proc", "");
589 
590 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
591 	sysctl_kern_proc, "Process table");
592 
593 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
594 	sysctl_kern_proc, "Process table");
595 
596 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
597 	sysctl_kern_proc, "Process table");
598 
599 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
600 	sysctl_kern_proc, "Process table");
601 
602 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
603 	sysctl_kern_proc, "Process table");
604