xref: /dragonfly/sys/kern/kern_proc.c (revision 984263bc) 
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: src/sys/kern/kern_proc.c,v 1.63.2.9 2003/05/08 07:47:16 kbyanc 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/malloc.h>
42 #include <sys/proc.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 int ps_showallprocs = 1;
59 SYSCTL_INT(_kern, OID_AUTO, ps_showallprocs, CTLFLAG_RW,
60     &ps_showallprocs, 0, "");
61 
62 static void pgdelete	__P((struct pgrp *));
63 
64 static void	orphanpg __P((struct pgrp *pg));
65 
66 /*
67  * Other process lists
68  */
69 struct pidhashhead *pidhashtbl;
70 u_long pidhash;
71 struct pgrphashhead *pgrphashtbl;
72 u_long pgrphash;
73 struct proclist allproc;
74 struct proclist zombproc;
75 vm_zone_t proc_zone;
76 
77 /*
78  * Initialize global process hashing structures.
79  */
80 void
81 procinit()
82 {
83 
84 	LIST_INIT(&allproc);
85 	LIST_INIT(&zombproc);
86 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
87 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
88 	proc_zone = zinit("PROC", sizeof (struct proc), 0, 0, 5);
89 	uihashinit();
90 }
91 
92 /*
93  * Is p an inferior of the current process?
94  */
95 int
96 inferior(p)
97 	register struct proc *p;
98 {
99 
100 	for (; p != curproc; p = p->p_pptr)
101 		if (p->p_pid == 0)
102 			return (0);
103 	return (1);
104 }
105 
106 /*
107  * Locate a process by number
108  */
109 struct proc *
110 pfind(pid)
111 	register pid_t pid;
112 {
113 	register struct proc *p;
114 
115 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
116 		if (p->p_pid == pid)
117 			return (p);
118 	return (NULL);
119 }
120 
121 /*
122  * Locate a process group by number
123  */
124 struct pgrp *
125 pgfind(pgid)
126 	register pid_t pgid;
127 {
128 	register struct pgrp *pgrp;
129 
130 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash)
131 		if (pgrp->pg_id == pgid)
132 			return (pgrp);
133 	return (NULL);
134 }
135 
136 /*
137  * Move p to a new or existing process group (and session)
138  */
139 int
140 enterpgrp(p, pgid, mksess)
141 	register struct proc *p;
142 	pid_t pgid;
143 	int mksess;
144 {
145 	register struct pgrp *pgrp = pgfind(pgid);
146 
147 	KASSERT(pgrp == NULL || !mksess,
148 	    ("enterpgrp: setsid into non-empty pgrp"));
149 	KASSERT(!SESS_LEADER(p),
150 	    ("enterpgrp: session leader attempted setpgrp"));
151 
152 	if (pgrp == NULL) {
153 		pid_t savepid = p->p_pid;
154 		struct proc *np;
155 		/*
156 		 * new process group
157 		 */
158 		KASSERT(p->p_pid == pgid,
159 		    ("enterpgrp: new pgrp and pid != pgid"));
160 		if ((np = pfind(savepid)) == NULL || np != p)
161 			return (ESRCH);
162 		MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
163 		    M_WAITOK);
164 		if (mksess) {
165 			register struct session *sess;
166 
167 			/*
168 			 * new session
169 			 */
170 			MALLOC(sess, struct session *, sizeof(struct session),
171 			    M_SESSION, M_WAITOK);
172 			sess->s_leader = p;
173 			sess->s_sid = p->p_pid;
174 			sess->s_count = 1;
175 			sess->s_ttyvp = NULL;
176 			sess->s_ttyp = NULL;
177 			bcopy(p->p_session->s_login, sess->s_login,
178 			    sizeof(sess->s_login));
179 			p->p_flag &= ~P_CONTROLT;
180 			pgrp->pg_session = sess;
181 			KASSERT(p == curproc,
182 			    ("enterpgrp: mksession and p != curproc"));
183 		} else {
184 			pgrp->pg_session = p->p_session;
185 			pgrp->pg_session->s_count++;
186 		}
187 		pgrp->pg_id = pgid;
188 		LIST_INIT(&pgrp->pg_members);
189 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
190 		pgrp->pg_jobc = 0;
191 		SLIST_INIT(&pgrp->pg_sigiolst);
192 	} else if (pgrp == p->p_pgrp)
193 		return (0);
194 
195 	/*
196 	 * Adjust eligibility of affected pgrps to participate in job control.
197 	 * Increment eligibility counts before decrementing, otherwise we
198 	 * could reach 0 spuriously during the first call.
199 	 */
200 	fixjobc(p, pgrp, 1);
201 	fixjobc(p, p->p_pgrp, 0);
202 
203 	LIST_REMOVE(p, p_pglist);
204 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
205 		pgdelete(p->p_pgrp);
206 	p->p_pgrp = pgrp;
207 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
208 	return (0);
209 }
210 
211 /*
212  * remove process from process group
213  */
214 int
215 leavepgrp(p)
216 	register struct proc *p;
217 {
218 
219 	LIST_REMOVE(p, p_pglist);
220 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
221 		pgdelete(p->p_pgrp);
222 	p->p_pgrp = 0;
223 	return (0);
224 }
225 
226 /*
227  * delete a process group
228  */
229 static void
230 pgdelete(pgrp)
231 	register struct pgrp *pgrp;
232 {
233 
234 	/*
235 	 * Reset any sigio structures pointing to us as a result of
236 	 * F_SETOWN with our pgid.
237 	 */
238 	funsetownlst(&pgrp->pg_sigiolst);
239 
240 	if (pgrp->pg_session->s_ttyp != NULL &&
241 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
242 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
243 	LIST_REMOVE(pgrp, pg_hash);
244 	if (--pgrp->pg_session->s_count == 0)
245 		FREE(pgrp->pg_session, M_SESSION);
246 	FREE(pgrp, M_PGRP);
247 }
248 
249 /*
250  * Adjust pgrp jobc counters when specified process changes process group.
251  * We count the number of processes in each process group that "qualify"
252  * the group for terminal job control (those with a parent in a different
253  * process group of the same session).  If that count reaches zero, the
254  * process group becomes orphaned.  Check both the specified process'
255  * process group and that of its children.
256  * entering == 0 => p is leaving specified group.
257  * entering == 1 => p is entering specified group.
258  */
259 void
260 fixjobc(p, pgrp, entering)
261 	register struct proc *p;
262 	register struct pgrp *pgrp;
263 	int entering;
264 {
265 	register struct pgrp *hispgrp;
266 	register struct session *mysession = pgrp->pg_session;
267 
268 	/*
269 	 * Check p's parent to see whether p qualifies its own process
270 	 * group; if so, adjust count for p's process group.
271 	 */
272 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
273 	    hispgrp->pg_session == mysession) {
274 		if (entering)
275 			pgrp->pg_jobc++;
276 		else if (--pgrp->pg_jobc == 0)
277 			orphanpg(pgrp);
278 	}
279 
280 	/*
281 	 * Check this process' children to see whether they qualify
282 	 * their process groups; if so, adjust counts for children's
283 	 * process groups.
284 	 */
285 	LIST_FOREACH(p, &p->p_children, p_sibling)
286 		if ((hispgrp = p->p_pgrp) != pgrp &&
287 		    hispgrp->pg_session == mysession &&
288 		    p->p_stat != SZOMB) {
289 			if (entering)
290 				hispgrp->pg_jobc++;
291 			else if (--hispgrp->pg_jobc == 0)
292 				orphanpg(hispgrp);
293 		}
294 }
295 
296 /*
297  * A process group has become orphaned;
298  * if there are any stopped processes in the group,
299  * hang-up all process in that group.
300  */
301 static void
302 orphanpg(pg)
303 	struct pgrp *pg;
304 {
305 	register struct proc *p;
306 
307 	LIST_FOREACH(p, &pg->pg_members, p_pglist) {
308 		if (p->p_stat == SSTOP) {
309 			LIST_FOREACH(p, &pg->pg_members, p_pglist) {
310 				psignal(p, SIGHUP);
311 				psignal(p, SIGCONT);
312 			}
313 			return;
314 		}
315 	}
316 }
317 
318 #include "opt_ddb.h"
319 #ifdef DDB
320 #include <ddb/ddb.h>
321 
322 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
323 {
324 	register struct pgrp *pgrp;
325 	register struct proc *p;
326 	register int i;
327 
328 	for (i = 0; i <= pgrphash; i++) {
329 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
330 			printf("\tindx %d\n", i);
331 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
332 				printf(
333 			"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
334 				    (void *)pgrp, (long)pgrp->pg_id,
335 				    (void *)pgrp->pg_session,
336 				    pgrp->pg_session->s_count,
337 				    (void *)LIST_FIRST(&pgrp->pg_members));
338 				LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
339 					printf("\t\tpid %ld addr %p pgrp %p\n",
340 					    (long)p->p_pid, (void *)p,
341 					    (void *)p->p_pgrp);
342 				}
343 			}
344 		}
345 	}
346 }
347 #endif /* DDB */
348 
349 /*
350  * Fill in an eproc structure for the specified process.
351  */
352 void
353 fill_eproc(p, ep)
354 	register struct proc *p;
355 	register struct eproc *ep;
356 {
357 	register struct tty *tp;
358 
359 	bzero(ep, sizeof(*ep));
360 
361 	ep->e_paddr = p;
362 	if (p->p_cred) {
363 		ep->e_pcred = *p->p_cred;
364 		if (p->p_ucred)
365 			ep->e_ucred = *p->p_ucred;
366 	}
367 	if (p->p_procsig) {
368 		ep->e_procsig = *p->p_procsig;
369 	}
370 	if (p->p_stat != SIDL && p->p_stat != SZOMB && p->p_vmspace != NULL) {
371 		register struct vmspace *vm = p->p_vmspace;
372 		ep->e_vm = *vm;
373 		ep->e_vm.vm_rssize = vmspace_resident_count(vm); /*XXX*/
374 	}
375 	if ((p->p_flag & P_INMEM) && p->p_stats)
376 		ep->e_stats = *p->p_stats;
377 	if (p->p_pptr)
378 		ep->e_ppid = p->p_pptr->p_pid;
379 	if (p->p_pgrp) {
380 		ep->e_pgid = p->p_pgrp->pg_id;
381 		ep->e_jobc = p->p_pgrp->pg_jobc;
382 		ep->e_sess = p->p_pgrp->pg_session;
383 
384 		if (ep->e_sess) {
385 			bcopy(ep->e_sess->s_login, ep->e_login, sizeof(ep->e_login));
386 			if (ep->e_sess->s_ttyvp)
387 				ep->e_flag = EPROC_CTTY;
388 			if (p->p_session && SESS_LEADER(p))
389 				ep->e_flag |= EPROC_SLEADER;
390 		}
391 	}
392 	if ((p->p_flag & P_CONTROLT) &&
393 	    (ep->e_sess != NULL) &&
394 	    ((tp = ep->e_sess->s_ttyp) != NULL)) {
395 		ep->e_tdev = dev2udev(tp->t_dev);
396 		ep->e_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
397 		ep->e_tsess = tp->t_session;
398 	} else
399 		ep->e_tdev = NOUDEV;
400 	if (p->p_wmesg) {
401 		strncpy(ep->e_wmesg, p->p_wmesg, WMESGLEN);
402 		ep->e_wmesg[WMESGLEN] = 0;
403 	}
404 }
405 
406 struct proc *
407 zpfind(pid_t pid)
408 {
409 	struct proc *p;
410 
411 	LIST_FOREACH(p, &zombproc, p_list)
412 		if (p->p_pid == pid)
413 			return (p);
414 	return (NULL);
415 }
416 
417 
418 static int
419 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int doingzomb)
420 {
421 	struct eproc eproc;
422 	int error;
423 	pid_t pid = p->p_pid;
424 
425 	fill_eproc(p, &eproc);
426 	error = SYSCTL_OUT(req,(caddr_t)p, sizeof(struct proc));
427 	if (error)
428 		return (error);
429 	error = SYSCTL_OUT(req,(caddr_t)&eproc, sizeof(eproc));
430 	if (error)
431 		return (error);
432 	if (!doingzomb && pid && (pfind(pid) != p))
433 		return EAGAIN;
434 	if (doingzomb && zpfind(pid) != p)
435 		return EAGAIN;
436 	return (0);
437 }
438 
439 static int
440 sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
441 {
442 	int *name = (int*) arg1;
443 	u_int namelen = arg2;
444 	struct proc *p;
445 	int doingzomb;
446 	int error = 0;
447 
448 	if (oidp->oid_number == KERN_PROC_PID) {
449 		if (namelen != 1)
450 			return (EINVAL);
451 		p = pfind((pid_t)name[0]);
452 		if (!p)
453 			return (0);
454 		if (!PRISON_CHECK(curproc, p))
455 			return (0);
456 		error = sysctl_out_proc(p, req, 0);
457 		return (error);
458 	}
459 	if (oidp->oid_number == KERN_PROC_ALL && !namelen)
460 		;
461 	else if (oidp->oid_number != KERN_PROC_ALL && namelen == 1)
462 		;
463 	else
464 		return (EINVAL);
465 
466 	if (!req->oldptr) {
467 		/* overestimate by 5 procs */
468 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
469 		if (error)
470 			return (error);
471 	}
472 	for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
473 		if (!doingzomb)
474 			p = LIST_FIRST(&allproc);
475 		else
476 			p = LIST_FIRST(&zombproc);
477 		for (; p != 0; p = LIST_NEXT(p, p_list)) {
478 			/*
479 			 * Show a user only their processes.
480 			 */
481 			if ((!ps_showallprocs) && p_trespass(curproc, p))
482 				continue;
483 			/*
484 			 * Skip embryonic processes.
485 			 */
486 			if (p->p_stat == SIDL)
487 				continue;
488 			/*
489 			 * TODO - make more efficient (see notes below).
490 			 * do by session.
491 			 */
492 			switch (oidp->oid_number) {
493 
494 			case KERN_PROC_PGRP:
495 				/* could do this by traversing pgrp */
496 				if (p->p_pgrp == NULL ||
497 				    p->p_pgrp->pg_id != (pid_t)name[0])
498 					continue;
499 				break;
500 
501 			case KERN_PROC_TTY:
502 				if ((p->p_flag & P_CONTROLT) == 0 ||
503 				    p->p_session == NULL ||
504 				    p->p_session->s_ttyp == NULL ||
505 				    dev2udev(p->p_session->s_ttyp->t_dev) !=
506 					(udev_t)name[0])
507 					continue;
508 				break;
509 
510 			case KERN_PROC_UID:
511 				if (p->p_ucred == NULL ||
512 				    p->p_ucred->cr_uid != (uid_t)name[0])
513 					continue;
514 				break;
515 
516 			case KERN_PROC_RUID:
517 				if (p->p_ucred == NULL ||
518 				    p->p_cred->p_ruid != (uid_t)name[0])
519 					continue;
520 				break;
521 			}
522 
523 			if (!PRISON_CHECK(curproc, p))
524 				continue;
525 
526 			error = sysctl_out_proc(p, req, doingzomb);
527 			if (error)
528 				return (error);
529 		}
530 	}
531 	return (0);
532 }
533 
534 /*
535  * This sysctl allows a process to retrieve the argument list or process
536  * title for another process without groping around in the address space
537  * of the other process.  It also allow a process to set its own "process
538  * title to a string of its own choice.
539  */
540 static int
541 sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
542 {
543 	int *name = (int*) arg1;
544 	u_int namelen = arg2;
545 	struct proc *p;
546 	struct pargs *pa;
547 	int error = 0;
548 
549 	if (namelen != 1)
550 		return (EINVAL);
551 
552 	p = pfind((pid_t)name[0]);
553 	if (!p)
554 		return (0);
555 
556 	if ((!ps_argsopen) && p_trespass(curproc, p))
557 		return (0);
558 
559 	if (req->newptr && curproc != p)
560 		return (EPERM);
561 
562 	if (req->oldptr && p->p_args != NULL)
563 		error = SYSCTL_OUT(req, p->p_args->ar_args, p->p_args->ar_length);
564 	if (req->newptr == NULL)
565 		return (error);
566 
567 	if (p->p_args && --p->p_args->ar_ref == 0)
568 		FREE(p->p_args, M_PARGS);
569 	p->p_args = NULL;
570 
571 	if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
572 		return (error);
573 
574 	MALLOC(pa, struct pargs *, sizeof(struct pargs) + req->newlen,
575 	    M_PARGS, M_WAITOK);
576 	pa->ar_ref = 1;
577 	pa->ar_length = req->newlen;
578 	error = SYSCTL_IN(req, pa->ar_args, req->newlen);
579 	if (!error)
580 		p->p_args = pa;
581 	else
582 		FREE(pa, M_PARGS);
583 	return (error);
584 }
585 
586 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
587 
588 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
589 	0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
590 
591 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
592 	sysctl_kern_proc, "Process table");
593 
594 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
595 	sysctl_kern_proc, "Process table");
596 
597 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
598 	sysctl_kern_proc, "Process table");
599 
600 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
601 	sysctl_kern_proc, "Process table");
602 
603 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
604 	sysctl_kern_proc, "Process table");
605 
606 SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY,
607 	sysctl_kern_proc_args, "Process argument list");
608