xref: /freebsd/sys/kern/kern_proc.c (revision ef5d438ed4bc17ad7ece3e40fe4d1f9baf3aadf7)
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	8.4 (Berkeley) 1/4/94
34  * $Id: kern_proc.c,v 1.14 1995/12/14 08:31:30 phk 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/buf.h>
43 #include <sys/acct.h>
44 #include <sys/wait.h>
45 #include <sys/file.h>
46 #include <ufs/ufs/quota.h>
47 #include <sys/uio.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/ioctl.h>
51 #include <sys/tty.h>
52 #include <sys/signalvar.h>
53 #include <vm/vm.h>
54 #include <vm/vm_param.h>
55 #include <vm/vm_prot.h>
56 #include <vm/lock.h>
57 #include <vm/pmap.h>
58 #include <vm/vm_map.h>
59 #include <sys/user.h>
60 
61 struct prochd qs[NQS];		/* as good a place as any... */
62 struct prochd rtqs[NQS];	/* Space for REALTIME queues too */
63 struct prochd idqs[NQS];	/* Space for IDLE queues too */
64 
65 volatile struct proc *allproc;	/* all processes */
66 struct proc *zombproc;		/* just zombies */
67 
68 static void pgdelete	__P((struct pgrp *));
69 
70 /*
71  * Structure associated with user cacheing.
72  */
73 static struct uidinfo {
74 	struct	uidinfo *ui_next;
75 	struct	uidinfo **ui_prev;
76 	uid_t	ui_uid;
77 	long	ui_proccnt;
78 } **uihashtbl;
79 static u_long	uihash;		/* size of hash table - 1 */
80 #define	UIHASH(uid)	((uid) & uihash)
81 
82 static void	orphanpg __P((struct pgrp *pg));
83 
84 /*
85  * Allocate a hash table.
86  */
87 void
88 usrinfoinit()
89 {
90 
91 	uihashtbl = hashinit(maxproc / 16, M_PROC, &uihash);
92 }
93 
94 /*
95  * Change the count associated with number of processes
96  * a given user is using.
97  */
98 int
99 chgproccnt(uid, diff)
100 	uid_t	uid;
101 	int	diff;
102 {
103 	register struct uidinfo **uipp, *uip, *uiq;
104 
105 	uipp = &uihashtbl[UIHASH(uid)];
106 	for (uip = *uipp; uip; uip = uip->ui_next)
107 		if (uip->ui_uid == uid)
108 			break;
109 	if (uip) {
110 		uip->ui_proccnt += diff;
111 		if (uip->ui_proccnt > 0)
112 			return (uip->ui_proccnt);
113 		if (uip->ui_proccnt < 0)
114 			panic("chgproccnt: procs < 0");
115 		if ((uiq = uip->ui_next))
116 			uiq->ui_prev = uip->ui_prev;
117 		*uip->ui_prev = uiq;
118 		FREE(uip, M_PROC);
119 		return (0);
120 	}
121 	if (diff <= 0) {
122 		if (diff == 0)
123 			return(0);
124 		panic("chgproccnt: lost user");
125 	}
126 	MALLOC(uip, struct uidinfo *, sizeof(*uip), M_PROC, M_WAITOK);
127 	if ((uiq = *uipp))
128 		uiq->ui_prev = &uip->ui_next;
129 	uip->ui_next = uiq;
130 	uip->ui_prev = uipp;
131 	*uipp = uip;
132 	uip->ui_uid = uid;
133 	uip->ui_proccnt = diff;
134 	return (diff);
135 }
136 
137 /*
138  * Is p an inferior of the current process?
139  */
140 int
141 inferior(p)
142 	register struct proc *p;
143 {
144 
145 	for (; p != curproc; p = p->p_pptr)
146 		if (p->p_pid == 0)
147 			return (0);
148 	return (1);
149 }
150 
151 /*
152  * Locate a process by number
153  */
154 struct proc *
155 pfind(pid)
156 	register pid_t pid;
157 {
158 	register struct proc *p;
159 
160 	for (p = pidhash[PIDHASH(pid)]; p != NULL; p = p->p_hash)
161 		if (p->p_pid == pid)
162 			return (p);
163 	return (NULL);
164 }
165 
166 /*
167  * Locate a process group by number
168  */
169 struct pgrp *
170 pgfind(pgid)
171 	register pid_t pgid;
172 {
173 	register struct pgrp *pgrp;
174 
175 	for (pgrp = pgrphash[PIDHASH(pgid)];
176 	    pgrp != NULL; pgrp = pgrp->pg_hforw)
177 		if (pgrp->pg_id == pgid)
178 			return (pgrp);
179 	return (NULL);
180 }
181 
182 /*
183  * Move p to a new or existing process group (and session)
184  */
185 int
186 enterpgrp(p, pgid, mksess)
187 	register struct proc *p;
188 	pid_t pgid;
189 	int mksess;
190 {
191 	register struct pgrp *pgrp = pgfind(pgid);
192 	register struct proc **pp;
193 	int n;
194 
195 #ifdef DIAGNOSTIC
196 	if (pgrp != NULL && mksess)	/* firewalls */
197 		panic("enterpgrp: setsid into non-empty pgrp");
198 	if (SESS_LEADER(p))
199 		panic("enterpgrp: session leader attempted setpgrp");
200 #endif
201 	if (pgrp == NULL) {
202 		pid_t savepid = p->p_pid;
203 		struct proc *np;
204 		/*
205 		 * new process group
206 		 */
207 #ifdef DIAGNOSTIC
208 		if (p->p_pid != pgid)
209 			panic("enterpgrp: new pgrp and pid != pgid");
210 #endif
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_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 		pgrp->pg_hforw = pgrphash[n = PIDHASH(pgid)];
241 		pgrphash[n] = pgrp;
242 		pgrp->pg_jobc = 0;
243 		pgrp->pg_mem = NULL;
244 	} else if (pgrp == p->p_pgrp)
245 		return (0);
246 
247 	/*
248 	 * Adjust eligibility of affected pgrps to participate in job control.
249 	 * Increment eligibility counts before decrementing, otherwise we
250 	 * could reach 0 spuriously during the first call.
251 	 */
252 	fixjobc(p, pgrp, 1);
253 	fixjobc(p, p->p_pgrp, 0);
254 
255 	/*
256 	 * unlink p from old process group
257 	 */
258 	for (pp = &p->p_pgrp->pg_mem; *pp; pp = &(*pp)->p_pgrpnxt) {
259 		if (*pp == p) {
260 			*pp = p->p_pgrpnxt;
261 			break;
262 		}
263 	}
264 #ifdef DIAGNOSTIC
265 	if (pp == NULL)
266 		panic("enterpgrp: can't find p on old pgrp");
267 #endif
268 	/*
269 	 * delete old if empty
270 	 */
271 	if (p->p_pgrp->pg_mem == 0)
272 		pgdelete(p->p_pgrp);
273 	/*
274 	 * link into new one
275 	 */
276 	p->p_pgrp = pgrp;
277 	p->p_pgrpnxt = pgrp->pg_mem;
278 	pgrp->pg_mem = p;
279 	return (0);
280 }
281 
282 /*
283  * remove process from process group
284  */
285 int
286 leavepgrp(p)
287 	register struct proc *p;
288 {
289 	register struct proc **pp = &p->p_pgrp->pg_mem;
290 
291 	for (; *pp; pp = &(*pp)->p_pgrpnxt) {
292 		if (*pp == p) {
293 			*pp = p->p_pgrpnxt;
294 			break;
295 		}
296 	}
297 #ifdef DIAGNOSTIC
298 	if (pp == NULL)
299 		panic("leavepgrp: can't find p in pgrp");
300 #endif
301 	if (!p->p_pgrp->pg_mem)
302 		pgdelete(p->p_pgrp);
303 	p->p_pgrp = 0;
304 	return (0);
305 }
306 
307 /*
308  * delete a process group
309  */
310 static void
311 pgdelete(pgrp)
312 	register struct pgrp *pgrp;
313 {
314 	register struct pgrp **pgp = &pgrphash[PIDHASH(pgrp->pg_id)];
315 
316 	if (pgrp->pg_session->s_ttyp != NULL &&
317 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
318 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
319 	for (; *pgp; pgp = &(*pgp)->pg_hforw) {
320 		if (*pgp == pgrp) {
321 			*pgp = pgrp->pg_hforw;
322 			break;
323 		}
324 	}
325 #ifdef DIAGNOSTIC
326 	if (pgp == NULL)
327 		panic("pgdelete: can't find pgrp on hash chain");
328 #endif
329 	if (--pgrp->pg_session->s_count == 0)
330 		FREE(pgrp->pg_session, M_SESSION);
331 	FREE(pgrp, M_PGRP);
332 }
333 
334 /*
335  * Adjust pgrp jobc counters when specified process changes process group.
336  * We count the number of processes in each process group that "qualify"
337  * the group for terminal job control (those with a parent in a different
338  * process group of the same session).  If that count reaches zero, the
339  * process group becomes orphaned.  Check both the specified process'
340  * process group and that of its children.
341  * entering == 0 => p is leaving specified group.
342  * entering == 1 => p is entering specified group.
343  */
344 void
345 fixjobc(p, pgrp, entering)
346 	register struct proc *p;
347 	register struct pgrp *pgrp;
348 	int entering;
349 {
350 	register struct pgrp *hispgrp;
351 	register struct session *mysession = pgrp->pg_session;
352 
353 	/*
354 	 * Check p's parent to see whether p qualifies its own process
355 	 * group; if so, adjust count for p's process group.
356 	 */
357 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
358 	    hispgrp->pg_session == mysession)
359 		if (entering)
360 			pgrp->pg_jobc++;
361 		else if (--pgrp->pg_jobc == 0)
362 			orphanpg(pgrp);
363 
364 	/*
365 	 * Check this process' children to see whether they qualify
366 	 * their process groups; if so, adjust counts for children's
367 	 * process groups.
368 	 */
369 	for (p = p->p_cptr; p; p = p->p_osptr)
370 		if ((hispgrp = p->p_pgrp) != pgrp &&
371 		    hispgrp->pg_session == mysession &&
372 		    p->p_stat != SZOMB)
373 			if (entering)
374 				hispgrp->pg_jobc++;
375 			else if (--hispgrp->pg_jobc == 0)
376 				orphanpg(hispgrp);
377 }
378 
379 /*
380  * A process group has become orphaned;
381  * if there are any stopped processes in the group,
382  * hang-up all process in that group.
383  */
384 static void
385 orphanpg(pg)
386 	struct pgrp *pg;
387 {
388 	register struct proc *p;
389 
390 	for (p = pg->pg_mem; p; p = p->p_pgrpnxt) {
391 		if (p->p_stat == SSTOP) {
392 			for (p = pg->pg_mem; p; p = p->p_pgrpnxt) {
393 				psignal(p, SIGHUP);
394 				psignal(p, SIGCONT);
395 			}
396 			return;
397 		}
398 	}
399 }
400 
401 #ifdef debug
402 /* DEBUG */
403 pgrpdump()
404 {
405 	register struct pgrp *pgrp;
406 	register struct proc *p;
407 	register i;
408 
409 	for (i=0; i<PIDHSZ; i++) {
410 		if (pgrphash[i]) {
411 		  printf("\tindx %d\n", i);
412 		  for (pgrp=pgrphash[i]; pgrp; pgrp=pgrp->pg_hforw) {
413 		    printf("\tpgrp %x, pgid %d, sess %x, sesscnt %d, mem %x\n",
414 			pgrp, pgrp->pg_id, pgrp->pg_session,
415 			pgrp->pg_session->s_count, pgrp->pg_mem);
416 		    for (p=pgrp->pg_mem; p; p=p->p_pgrpnxt) {
417 			printf("\t\tpid %d addr %x pgrp %x\n",
418 				p->p_pid, p, p->p_pgrp);
419 		    }
420 		  }
421 
422 		}
423 	}
424 }
425 #endif /* debug */
426 
427 /*
428  * Fill in an eproc structure for the specified process.
429  */
430 void
431 fill_eproc(p, ep)
432 	register struct proc *p;
433 	register struct eproc *ep;
434 {
435 	register struct tty *tp;
436 
437 	bzero(ep, sizeof(*ep));
438 
439 	ep->e_paddr = p;
440 	if (p->p_cred) {
441 		ep->e_pcred = *p->p_cred;
442 		if (p->p_ucred)
443 			ep->e_ucred = *p->p_ucred;
444 	}
445 	if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
446 		register struct vmspace *vm = p->p_vmspace;
447 
448 #ifdef pmap_resident_count
449 		ep->e_vm.vm_rssize = pmap_resident_count(&vm->vm_pmap); /*XXX*/
450 #else
451 		ep->e_vm.vm_rssize = vm->vm_rssize;
452 #endif
453 		ep->e_vm.vm_tsize = vm->vm_tsize;
454 		ep->e_vm.vm_dsize = vm->vm_dsize;
455 		ep->e_vm.vm_ssize = vm->vm_ssize;
456 #ifndef sparc
457 		ep->e_vm.vm_pmap = vm->vm_pmap;
458 #endif
459 	}
460 	if (p->p_pptr)
461 		ep->e_ppid = p->p_pptr->p_pid;
462 	if (p->p_pgrp) {
463 		ep->e_sess = p->p_pgrp->pg_session;
464 		ep->e_pgid = p->p_pgrp->pg_id;
465 		ep->e_jobc = p->p_pgrp->pg_jobc;
466 	}
467 	if (ep->e_sess)
468 		bcopy(ep->e_sess->s_login, ep->e_login, sizeof(ep->e_login));
469 	if ((p->p_flag & P_CONTROLT) &&
470 	    (ep->e_sess != NULL) &&
471 	    ((tp = ep->e_sess->s_ttyp) != NULL)) {
472 		ep->e_tdev = tp->t_dev;
473 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
474 		ep->e_tsess = tp->t_session;
475 	} else
476 		ep->e_tdev = NODEV;
477 	if (ep->e_sess && ep->e_sess->s_ttyvp)
478 		ep->e_flag = EPROC_CTTY;
479 	if (SESS_LEADER(p))
480 		ep->e_flag |= EPROC_SLEADER;
481 	if (p->p_wmesg) {
482 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
483 		ep->e_wmesg[WMESGLEN] = 0;
484 	}
485 }
486 
487 static int
488 sysctl_kern_proc SYSCTL_HANDLER_ARGS
489 {
490 	int *name = (int*) arg1;
491 	u_int namelen = arg2;
492 	struct proc *p;
493 	int doingzomb;
494 	struct eproc eproc;
495 	int error = 0;
496 
497 	if (namelen != 2 && !(namelen == 1 && name[0] == KERN_PROC_ALL))
498 		return (EINVAL);
499 	if (!req->oldptr) {
500 		/*
501 		 * try over estimating by 5 procs
502 		 */
503 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
504 		if (error)
505 			return (error);
506 	}
507 	p = (struct proc *)allproc;
508 	doingzomb = 0;
509 again:
510 	for (; p != NULL; p = p->p_next) {
511 		/*
512 		 * Skip embryonic processes.
513 		 */
514 		if (p->p_stat == SIDL)
515 			continue;
516 		/*
517 		 * TODO - make more efficient (see notes below).
518 		 * do by session.
519 		 */
520 		switch (name[0]) {
521 
522 		case KERN_PROC_PID:
523 			/* could do this with just a lookup */
524 			if (p->p_pid != (pid_t)name[1])
525 				continue;
526 			break;
527 
528 		case KERN_PROC_PGRP:
529 			/* could do this by traversing pgrp */
530 			if (p->p_pgrp == NULL || p->p_pgrp->pg_id != (pid_t)name[1])
531 				continue;
532 			break;
533 
534 		case KERN_PROC_TTY:
535 			if ((p->p_flag & P_CONTROLT) == 0 ||
536 			    p->p_session == NULL ||
537 			    p->p_session->s_ttyp == NULL ||
538 			    p->p_session->s_ttyp->t_dev != (dev_t)name[1])
539 				continue;
540 			break;
541 
542 		case KERN_PROC_UID:
543 			if (p->p_ucred == NULL || p->p_ucred->cr_uid != (uid_t)name[1])
544 				continue;
545 			break;
546 
547 		case KERN_PROC_RUID:
548 			if (p->p_ucred == NULL || p->p_cred->p_ruid != (uid_t)name[1])
549 				continue;
550 			break;
551 		}
552 
553 		fill_eproc(p, &eproc);
554 		error = SYSCTL_OUT(req,(caddr_t)p, sizeof(struct proc));
555 		if (error)
556 			return (error);
557 		error = SYSCTL_OUT(req,(caddr_t)&eproc, sizeof(eproc));
558 		if (error)
559 			return (error);
560 	}
561 	if (doingzomb == 0) {
562 		p = zombproc;
563 		doingzomb++;
564 		goto again;
565 	}
566 	return (0);
567 }
568 
569 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,
570 	sysctl_kern_proc, "Process table");
571