xref: /freebsd/sys/kern/kern_proc.c (revision cacdd70cc751fb68dec4b86c5e5b8c969b6e26ef)
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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)kern_proc.c	8.7 (Berkeley) 2/14/95
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include "opt_ddb.h"
36 #include "opt_kdtrace.h"
37 #include "opt_ktrace.h"
38 #include "opt_kstack_pages.h"
39 #include "opt_stack.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/malloc.h>
46 #include <sys/mount.h>
47 #include <sys/mutex.h>
48 #include <sys/proc.h>
49 #include <sys/refcount.h>
50 #include <sys/sbuf.h>
51 #include <sys/sysent.h>
52 #include <sys/sched.h>
53 #include <sys/smp.h>
54 #include <sys/stack.h>
55 #include <sys/sysctl.h>
56 #include <sys/filedesc.h>
57 #include <sys/tty.h>
58 #include <sys/signalvar.h>
59 #include <sys/sdt.h>
60 #include <sys/sx.h>
61 #include <sys/user.h>
62 #include <sys/jail.h>
63 #include <sys/vnode.h>
64 #include <sys/eventhandler.h>
65 #ifdef KTRACE
66 #include <sys/uio.h>
67 #include <sys/ktrace.h>
68 #endif
69 
70 #ifdef DDB
71 #include <ddb/ddb.h>
72 #endif
73 
74 #include <vm/vm.h>
75 #include <vm/vm_extern.h>
76 #include <vm/pmap.h>
77 #include <vm/vm_map.h>
78 #include <vm/vm_object.h>
79 #include <vm/uma.h>
80 
81 SDT_PROVIDER_DEFINE(proc);
82 SDT_PROBE_DEFINE(proc, kernel, ctor, entry);
83 SDT_PROBE_ARGTYPE(proc, kernel, ctor, entry, 0, "struct proc *");
84 SDT_PROBE_ARGTYPE(proc, kernel, ctor, entry, 1, "int");
85 SDT_PROBE_ARGTYPE(proc, kernel, ctor, entry, 2, "void *");
86 SDT_PROBE_ARGTYPE(proc, kernel, ctor, entry, 3, "int");
87 SDT_PROBE_DEFINE(proc, kernel, ctor, return);
88 SDT_PROBE_ARGTYPE(proc, kernel, ctor, return, 0, "struct proc *");
89 SDT_PROBE_ARGTYPE(proc, kernel, ctor, return, 1, "int");
90 SDT_PROBE_ARGTYPE(proc, kernel, ctor, return, 2, "void *");
91 SDT_PROBE_ARGTYPE(proc, kernel, ctor, return, 3, "int");
92 SDT_PROBE_DEFINE(proc, kernel, dtor, entry);
93 SDT_PROBE_ARGTYPE(proc, kernel, dtor, entry, 0, "struct proc *");
94 SDT_PROBE_ARGTYPE(proc, kernel, dtor, entry, 1, "int");
95 SDT_PROBE_ARGTYPE(proc, kernel, dtor, entry, 2, "void *");
96 SDT_PROBE_ARGTYPE(proc, kernel, dtor, entry, 3, "struct thread *");
97 SDT_PROBE_DEFINE(proc, kernel, dtor, return);
98 SDT_PROBE_ARGTYPE(proc, kernel, dtor, return, 0, "struct proc *");
99 SDT_PROBE_ARGTYPE(proc, kernel, dtor, return, 1, "int");
100 SDT_PROBE_ARGTYPE(proc, kernel, dtor, return, 2, "void *");
101 SDT_PROBE_DEFINE(proc, kernel, init, entry);
102 SDT_PROBE_ARGTYPE(proc, kernel, init, entry, 0, "struct proc *");
103 SDT_PROBE_ARGTYPE(proc, kernel, init, entry, 1, "int");
104 SDT_PROBE_ARGTYPE(proc, kernel, init, entry, 2, "int");
105 SDT_PROBE_DEFINE(proc, kernel, init, return);
106 SDT_PROBE_ARGTYPE(proc, kernel, init, return, 0, "struct proc *");
107 SDT_PROBE_ARGTYPE(proc, kernel, init, return, 1, "int");
108 SDT_PROBE_ARGTYPE(proc, kernel, init, return, 2, "int");
109 
110 MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
111 MALLOC_DEFINE(M_SESSION, "session", "session header");
112 static MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
113 MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
114 
115 static void doenterpgrp(struct proc *, struct pgrp *);
116 static void orphanpg(struct pgrp *pg);
117 static void fill_kinfo_proc_only(struct proc *p, struct kinfo_proc *kp);
118 static void fill_kinfo_thread(struct thread *td, struct kinfo_proc *kp,
119     int preferthread);
120 static void pgadjustjobc(struct pgrp *pgrp, int entering);
121 static void pgdelete(struct pgrp *);
122 static int proc_ctor(void *mem, int size, void *arg, int flags);
123 static void proc_dtor(void *mem, int size, void *arg);
124 static int proc_init(void *mem, int size, int flags);
125 static void proc_fini(void *mem, int size);
126 static void pargs_free(struct pargs *pa);
127 
128 /*
129  * Other process lists
130  */
131 struct pidhashhead *pidhashtbl;
132 u_long pidhash;
133 struct pgrphashhead *pgrphashtbl;
134 u_long pgrphash;
135 struct proclist allproc;
136 struct proclist zombproc;
137 struct sx allproc_lock;
138 struct sx proctree_lock;
139 struct mtx ppeers_lock;
140 uma_zone_t proc_zone;
141 uma_zone_t ithread_zone;
142 
143 int kstack_pages = KSTACK_PAGES;
144 SYSCTL_INT(_kern, OID_AUTO, kstack_pages, CTLFLAG_RD, &kstack_pages, 0, "");
145 
146 CTASSERT(sizeof(struct kinfo_proc) == KINFO_PROC_SIZE);
147 
148 /*
149  * Initialize global process hashing structures.
150  */
151 void
152 procinit()
153 {
154 
155 	sx_init(&allproc_lock, "allproc");
156 	sx_init(&proctree_lock, "proctree");
157 	mtx_init(&ppeers_lock, "p_peers", NULL, MTX_DEF);
158 	LIST_INIT(&allproc);
159 	LIST_INIT(&zombproc);
160 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
161 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
162 	proc_zone = uma_zcreate("PROC", sched_sizeof_proc(),
163 	    proc_ctor, proc_dtor, proc_init, proc_fini,
164 	    UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
165 	uihashinit();
166 }
167 
168 /*
169  * Prepare a proc for use.
170  */
171 static int
172 proc_ctor(void *mem, int size, void *arg, int flags)
173 {
174 	struct proc *p;
175 
176 	p = (struct proc *)mem;
177 	SDT_PROBE(proc, kernel, ctor , entry, p, size, arg, flags, 0);
178 	EVENTHANDLER_INVOKE(process_ctor, p);
179 	SDT_PROBE(proc, kernel, ctor , return, p, size, arg, flags, 0);
180 	return (0);
181 }
182 
183 /*
184  * Reclaim a proc after use.
185  */
186 static void
187 proc_dtor(void *mem, int size, void *arg)
188 {
189 	struct proc *p;
190 	struct thread *td;
191 
192 	/* INVARIANTS checks go here */
193 	p = (struct proc *)mem;
194 	td = FIRST_THREAD_IN_PROC(p);
195 	SDT_PROBE(proc, kernel, dtor, entry, p, size, arg, td, 0);
196 	if (td != NULL) {
197 #ifdef INVARIANTS
198 		KASSERT((p->p_numthreads == 1),
199 		    ("bad number of threads in exiting process"));
200 		KASSERT(STAILQ_EMPTY(&p->p_ktr), ("proc_dtor: non-empty p_ktr"));
201 #endif
202 		/* Dispose of an alternate kstack, if it exists.
203 		 * XXX What if there are more than one thread in the proc?
204 		 *     The first thread in the proc is special and not
205 		 *     freed, so you gotta do this here.
206 		 */
207 		if (((p->p_flag & P_KTHREAD) != 0) && (td->td_altkstack != 0))
208 			vm_thread_dispose_altkstack(td);
209 	}
210 	EVENTHANDLER_INVOKE(process_dtor, p);
211 	if (p->p_ksi != NULL)
212 		KASSERT(! KSI_ONQ(p->p_ksi), ("SIGCHLD queue"));
213 	SDT_PROBE(proc, kernel, dtor, return, p, size, arg, 0, 0);
214 }
215 
216 /*
217  * Initialize type-stable parts of a proc (when newly created).
218  */
219 static int
220 proc_init(void *mem, int size, int flags)
221 {
222 	struct proc *p;
223 
224 	p = (struct proc *)mem;
225 	SDT_PROBE(proc, kernel, init, entry, p, size, flags, 0, 0);
226 	p->p_sched = (struct p_sched *)&p[1];
227 	bzero(&p->p_mtx, sizeof(struct mtx));
228 	mtx_init(&p->p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
229 	mtx_init(&p->p_slock, "process slock", NULL, MTX_SPIN | MTX_RECURSE);
230 	TAILQ_INIT(&p->p_threads);	     /* all threads in proc */
231 	EVENTHANDLER_INVOKE(process_init, p);
232 	p->p_stats = pstats_alloc();
233 	SDT_PROBE(proc, kernel, init, return, p, size, flags, 0, 0);
234 	return (0);
235 }
236 
237 /*
238  * UMA should ensure that this function is never called.
239  * Freeing a proc structure would violate type stability.
240  */
241 static void
242 proc_fini(void *mem, int size)
243 {
244 #ifdef notnow
245 	struct proc *p;
246 
247 	p = (struct proc *)mem;
248 	EVENTHANDLER_INVOKE(process_fini, p);
249 	pstats_free(p->p_stats);
250 	thread_free(FIRST_THREAD_IN_PROC(p));
251 	mtx_destroy(&p->p_mtx);
252 	if (p->p_ksi != NULL)
253 		ksiginfo_free(p->p_ksi);
254 #else
255 	panic("proc reclaimed");
256 #endif
257 }
258 
259 /*
260  * Is p an inferior of the current process?
261  */
262 int
263 inferior(p)
264 	register struct proc *p;
265 {
266 
267 	sx_assert(&proctree_lock, SX_LOCKED);
268 	for (; p != curproc; p = p->p_pptr)
269 		if (p->p_pid == 0)
270 			return (0);
271 	return (1);
272 }
273 
274 /*
275  * Locate a process by number; return only "live" processes -- i.e., neither
276  * zombies nor newly born but incompletely initialized processes.  By not
277  * returning processes in the PRS_NEW state, we allow callers to avoid
278  * testing for that condition to avoid dereferencing p_ucred, et al.
279  */
280 struct proc *
281 pfind(pid)
282 	register pid_t pid;
283 {
284 	register struct proc *p;
285 
286 	sx_slock(&allproc_lock);
287 	LIST_FOREACH(p, PIDHASH(pid), p_hash)
288 		if (p->p_pid == pid) {
289 			if (p->p_state == PRS_NEW) {
290 				p = NULL;
291 				break;
292 			}
293 			PROC_LOCK(p);
294 			break;
295 		}
296 	sx_sunlock(&allproc_lock);
297 	return (p);
298 }
299 
300 /*
301  * Locate a process group by number.
302  * The caller must hold proctree_lock.
303  */
304 struct pgrp *
305 pgfind(pgid)
306 	register pid_t pgid;
307 {
308 	register struct pgrp *pgrp;
309 
310 	sx_assert(&proctree_lock, SX_LOCKED);
311 
312 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash) {
313 		if (pgrp->pg_id == pgid) {
314 			PGRP_LOCK(pgrp);
315 			return (pgrp);
316 		}
317 	}
318 	return (NULL);
319 }
320 
321 /*
322  * Create a new process group.
323  * pgid must be equal to the pid of p.
324  * Begin a new session if required.
325  */
326 int
327 enterpgrp(p, pgid, pgrp, sess)
328 	register struct proc *p;
329 	pid_t pgid;
330 	struct pgrp *pgrp;
331 	struct session *sess;
332 {
333 	struct pgrp *pgrp2;
334 
335 	sx_assert(&proctree_lock, SX_XLOCKED);
336 
337 	KASSERT(pgrp != NULL, ("enterpgrp: pgrp == NULL"));
338 	KASSERT(p->p_pid == pgid,
339 	    ("enterpgrp: new pgrp and pid != pgid"));
340 
341 	pgrp2 = pgfind(pgid);
342 
343 	KASSERT(pgrp2 == NULL,
344 	    ("enterpgrp: pgrp with pgid exists"));
345 	KASSERT(!SESS_LEADER(p),
346 	    ("enterpgrp: session leader attempted setpgrp"));
347 
348 	mtx_init(&pgrp->pg_mtx, "process group", NULL, MTX_DEF | MTX_DUPOK);
349 
350 	if (sess != NULL) {
351 		/*
352 		 * new session
353 		 */
354 		mtx_init(&sess->s_mtx, "session", NULL, MTX_DEF);
355 		mtx_lock(&Giant);       /* XXX TTY */
356 		PROC_LOCK(p);
357 		p->p_flag &= ~P_CONTROLT;
358 		PROC_UNLOCK(p);
359 		PGRP_LOCK(pgrp);
360 		sess->s_leader = p;
361 		sess->s_sid = p->p_pid;
362 		sess->s_count = 1;
363 		sess->s_ttyvp = NULL;
364 		sess->s_ttyp = NULL;
365 		bcopy(p->p_session->s_login, sess->s_login,
366 			    sizeof(sess->s_login));
367 		pgrp->pg_session = sess;
368 		KASSERT(p == curproc,
369 		    ("enterpgrp: mksession and p != curproc"));
370 	} else {
371 		mtx_lock(&Giant);       /* XXX TTY */
372 		pgrp->pg_session = p->p_session;
373 		SESS_LOCK(pgrp->pg_session);
374 		pgrp->pg_session->s_count++;
375 		SESS_UNLOCK(pgrp->pg_session);
376 		PGRP_LOCK(pgrp);
377 	}
378 	pgrp->pg_id = pgid;
379 	LIST_INIT(&pgrp->pg_members);
380 
381 	/*
382 	 * As we have an exclusive lock of proctree_lock,
383 	 * this should not deadlock.
384 	 */
385 	LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
386 	pgrp->pg_jobc = 0;
387 	SLIST_INIT(&pgrp->pg_sigiolst);
388 	PGRP_UNLOCK(pgrp);
389 	mtx_unlock(&Giant);       /* XXX TTY */
390 
391 	doenterpgrp(p, pgrp);
392 
393 	return (0);
394 }
395 
396 /*
397  * Move p to an existing process group
398  */
399 int
400 enterthispgrp(p, pgrp)
401 	register struct proc *p;
402 	struct pgrp *pgrp;
403 {
404 
405 	sx_assert(&proctree_lock, SX_XLOCKED);
406 	PROC_LOCK_ASSERT(p, MA_NOTOWNED);
407 	PGRP_LOCK_ASSERT(pgrp, MA_NOTOWNED);
408 	PGRP_LOCK_ASSERT(p->p_pgrp, MA_NOTOWNED);
409 	SESS_LOCK_ASSERT(p->p_session, MA_NOTOWNED);
410 	KASSERT(pgrp->pg_session == p->p_session,
411 		("%s: pgrp's session %p, p->p_session %p.\n",
412 		__func__,
413 		pgrp->pg_session,
414 		p->p_session));
415 	KASSERT(pgrp != p->p_pgrp,
416 		("%s: p belongs to pgrp.", __func__));
417 
418 	doenterpgrp(p, pgrp);
419 
420 	return (0);
421 }
422 
423 /*
424  * Move p to a process group
425  */
426 static void
427 doenterpgrp(p, pgrp)
428 	struct proc *p;
429 	struct pgrp *pgrp;
430 {
431 	struct pgrp *savepgrp;
432 
433 	sx_assert(&proctree_lock, SX_XLOCKED);
434 	PROC_LOCK_ASSERT(p, MA_NOTOWNED);
435 	PGRP_LOCK_ASSERT(pgrp, MA_NOTOWNED);
436 	PGRP_LOCK_ASSERT(p->p_pgrp, MA_NOTOWNED);
437 	SESS_LOCK_ASSERT(p->p_session, MA_NOTOWNED);
438 
439 	savepgrp = p->p_pgrp;
440 
441 	/*
442 	 * Adjust eligibility of affected pgrps to participate in job control.
443 	 * Increment eligibility counts before decrementing, otherwise we
444 	 * could reach 0 spuriously during the first call.
445 	 */
446 	fixjobc(p, pgrp, 1);
447 	fixjobc(p, p->p_pgrp, 0);
448 
449 	mtx_lock(&Giant);       /* XXX TTY */
450 	PGRP_LOCK(pgrp);
451 	PGRP_LOCK(savepgrp);
452 	PROC_LOCK(p);
453 	LIST_REMOVE(p, p_pglist);
454 	p->p_pgrp = pgrp;
455 	PROC_UNLOCK(p);
456 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
457 	PGRP_UNLOCK(savepgrp);
458 	PGRP_UNLOCK(pgrp);
459 	mtx_unlock(&Giant);     /* XXX TTY */
460 	if (LIST_EMPTY(&savepgrp->pg_members))
461 		pgdelete(savepgrp);
462 }
463 
464 /*
465  * remove process from process group
466  */
467 int
468 leavepgrp(p)
469 	register struct proc *p;
470 {
471 	struct pgrp *savepgrp;
472 
473 	sx_assert(&proctree_lock, SX_XLOCKED);
474 	savepgrp = p->p_pgrp;
475 	mtx_lock(&Giant);	/* XXX TTY */
476 	PGRP_LOCK(savepgrp);
477 	PROC_LOCK(p);
478 	LIST_REMOVE(p, p_pglist);
479 	p->p_pgrp = NULL;
480 	PROC_UNLOCK(p);
481 	PGRP_UNLOCK(savepgrp);
482 	mtx_unlock(&Giant);	/* XXX TTY */
483 	if (LIST_EMPTY(&savepgrp->pg_members))
484 		pgdelete(savepgrp);
485 	return (0);
486 }
487 
488 /*
489  * delete a process group
490  */
491 static void
492 pgdelete(pgrp)
493 	register struct pgrp *pgrp;
494 {
495 	struct session *savesess;
496 
497 	sx_assert(&proctree_lock, SX_XLOCKED);
498 	PGRP_LOCK_ASSERT(pgrp, MA_NOTOWNED);
499 	SESS_LOCK_ASSERT(pgrp->pg_session, MA_NOTOWNED);
500 
501 	/*
502 	 * Reset any sigio structures pointing to us as a result of
503 	 * F_SETOWN with our pgid.
504 	 */
505 	funsetownlst(&pgrp->pg_sigiolst);
506 
507 	mtx_lock(&Giant);       /* XXX TTY */
508 	PGRP_LOCK(pgrp);
509 	if (pgrp->pg_session->s_ttyp != NULL &&
510 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
511 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
512 	LIST_REMOVE(pgrp, pg_hash);
513 	savesess = pgrp->pg_session;
514 	SESSRELE(savesess);
515 	PGRP_UNLOCK(pgrp);
516 	mtx_destroy(&pgrp->pg_mtx);
517 	FREE(pgrp, M_PGRP);
518 	mtx_unlock(&Giant);     /* XXX TTY */
519 }
520 
521 static void
522 pgadjustjobc(pgrp, entering)
523 	struct pgrp *pgrp;
524 	int entering;
525 {
526 
527 	PGRP_LOCK(pgrp);
528 	if (entering)
529 		pgrp->pg_jobc++;
530 	else {
531 		--pgrp->pg_jobc;
532 		if (pgrp->pg_jobc == 0)
533 			orphanpg(pgrp);
534 	}
535 	PGRP_UNLOCK(pgrp);
536 }
537 
538 /*
539  * Adjust pgrp jobc counters when specified process changes process group.
540  * We count the number of processes in each process group that "qualify"
541  * the group for terminal job control (those with a parent in a different
542  * process group of the same session).  If that count reaches zero, the
543  * process group becomes orphaned.  Check both the specified process'
544  * process group and that of its children.
545  * entering == 0 => p is leaving specified group.
546  * entering == 1 => p is entering specified group.
547  */
548 void
549 fixjobc(p, pgrp, entering)
550 	register struct proc *p;
551 	register struct pgrp *pgrp;
552 	int entering;
553 {
554 	register struct pgrp *hispgrp;
555 	register struct session *mysession;
556 
557 	sx_assert(&proctree_lock, SX_LOCKED);
558 	PROC_LOCK_ASSERT(p, MA_NOTOWNED);
559 	PGRP_LOCK_ASSERT(pgrp, MA_NOTOWNED);
560 	SESS_LOCK_ASSERT(pgrp->pg_session, MA_NOTOWNED);
561 
562 	/*
563 	 * Check p's parent to see whether p qualifies its own process
564 	 * group; if so, adjust count for p's process group.
565 	 */
566 	mysession = pgrp->pg_session;
567 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
568 	    hispgrp->pg_session == mysession)
569 		pgadjustjobc(pgrp, entering);
570 
571 	/*
572 	 * Check this process' children to see whether they qualify
573 	 * their process groups; if so, adjust counts for children's
574 	 * process groups.
575 	 */
576 	LIST_FOREACH(p, &p->p_children, p_sibling) {
577 		hispgrp = p->p_pgrp;
578 		if (hispgrp == pgrp ||
579 		    hispgrp->pg_session != mysession)
580 			continue;
581 		PROC_LOCK(p);
582 		if (p->p_state == PRS_ZOMBIE) {
583 			PROC_UNLOCK(p);
584 			continue;
585 		}
586 		PROC_UNLOCK(p);
587 		pgadjustjobc(hispgrp, entering);
588 	}
589 }
590 
591 /*
592  * A process group has become orphaned;
593  * if there are any stopped processes in the group,
594  * hang-up all process in that group.
595  */
596 static void
597 orphanpg(pg)
598 	struct pgrp *pg;
599 {
600 	register struct proc *p;
601 
602 	PGRP_LOCK_ASSERT(pg, MA_OWNED);
603 
604 	LIST_FOREACH(p, &pg->pg_members, p_pglist) {
605 		PROC_LOCK(p);
606 		if (P_SHOULDSTOP(p)) {
607 			PROC_UNLOCK(p);
608 			LIST_FOREACH(p, &pg->pg_members, p_pglist) {
609 				PROC_LOCK(p);
610 				psignal(p, SIGHUP);
611 				psignal(p, SIGCONT);
612 				PROC_UNLOCK(p);
613 			}
614 			return;
615 		}
616 		PROC_UNLOCK(p);
617 	}
618 }
619 
620 void
621 sessrele(struct session *s)
622 {
623 	int i;
624 
625 	SESS_LOCK(s);
626 	i = --s->s_count;
627 	SESS_UNLOCK(s);
628 	if (i == 0) {
629 		if (s->s_ttyp != NULL)
630 			ttyrel(s->s_ttyp);
631 		mtx_destroy(&s->s_mtx);
632 		FREE(s, M_SESSION);
633 	}
634 }
635 
636 #include "opt_ddb.h"
637 #ifdef DDB
638 #include <ddb/ddb.h>
639 
640 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
641 {
642 	register struct pgrp *pgrp;
643 	register struct proc *p;
644 	register int i;
645 
646 	for (i = 0; i <= pgrphash; i++) {
647 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
648 			printf("\tindx %d\n", i);
649 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
650 				printf(
651 			"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
652 				    (void *)pgrp, (long)pgrp->pg_id,
653 				    (void *)pgrp->pg_session,
654 				    pgrp->pg_session->s_count,
655 				    (void *)LIST_FIRST(&pgrp->pg_members));
656 				LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
657 					printf("\t\tpid %ld addr %p pgrp %p\n",
658 					    (long)p->p_pid, (void *)p,
659 					    (void *)p->p_pgrp);
660 				}
661 			}
662 		}
663 	}
664 }
665 #endif /* DDB */
666 
667 /*
668  * Clear kinfo_proc and fill in any information that is common
669  * to all threads in the process.
670  * Must be called with the target process locked.
671  */
672 static void
673 fill_kinfo_proc_only(struct proc *p, struct kinfo_proc *kp)
674 {
675 	struct thread *td0;
676 	struct tty *tp;
677 	struct session *sp;
678 	struct ucred *cred;
679 	struct sigacts *ps;
680 
681 	PROC_LOCK_ASSERT(p, MA_OWNED);
682 	bzero(kp, sizeof(*kp));
683 
684 	kp->ki_structsize = sizeof(*kp);
685 	kp->ki_paddr = p;
686 	kp->ki_addr =/* p->p_addr; */0; /* XXX */
687 	kp->ki_args = p->p_args;
688 	kp->ki_textvp = p->p_textvp;
689 #ifdef KTRACE
690 	kp->ki_tracep = p->p_tracevp;
691 	mtx_lock(&ktrace_mtx);
692 	kp->ki_traceflag = p->p_traceflag;
693 	mtx_unlock(&ktrace_mtx);
694 #endif
695 	kp->ki_fd = p->p_fd;
696 	kp->ki_vmspace = p->p_vmspace;
697 	kp->ki_flag = p->p_flag;
698 	cred = p->p_ucred;
699 	if (cred) {
700 		kp->ki_uid = cred->cr_uid;
701 		kp->ki_ruid = cred->cr_ruid;
702 		kp->ki_svuid = cred->cr_svuid;
703 		/* XXX bde doesn't like KI_NGROUPS */
704 		kp->ki_ngroups = min(cred->cr_ngroups, KI_NGROUPS);
705 		bcopy(cred->cr_groups, kp->ki_groups,
706 		    kp->ki_ngroups * sizeof(gid_t));
707 		kp->ki_rgid = cred->cr_rgid;
708 		kp->ki_svgid = cred->cr_svgid;
709 		/* If jailed(cred), emulate the old P_JAILED flag. */
710 		if (jailed(cred)) {
711 			kp->ki_flag |= P_JAILED;
712 			/* If inside a jail, use 0 as a jail ID. */
713 			if (!jailed(curthread->td_ucred))
714 				kp->ki_jid = cred->cr_prison->pr_id;
715 		}
716 	}
717 	ps = p->p_sigacts;
718 	if (ps) {
719 		mtx_lock(&ps->ps_mtx);
720 		kp->ki_sigignore = ps->ps_sigignore;
721 		kp->ki_sigcatch = ps->ps_sigcatch;
722 		mtx_unlock(&ps->ps_mtx);
723 	}
724 	PROC_SLOCK(p);
725 	if (p->p_state != PRS_NEW &&
726 	    p->p_state != PRS_ZOMBIE &&
727 	    p->p_vmspace != NULL) {
728 		struct vmspace *vm = p->p_vmspace;
729 
730 		kp->ki_size = vm->vm_map.size;
731 		kp->ki_rssize = vmspace_resident_count(vm); /*XXX*/
732 		FOREACH_THREAD_IN_PROC(p, td0) {
733 			if (!TD_IS_SWAPPED(td0))
734 				kp->ki_rssize += td0->td_kstack_pages;
735 			if (td0->td_altkstack_obj != NULL)
736 				kp->ki_rssize += td0->td_altkstack_pages;
737 		}
738 		kp->ki_swrss = vm->vm_swrss;
739 		kp->ki_tsize = vm->vm_tsize;
740 		kp->ki_dsize = vm->vm_dsize;
741 		kp->ki_ssize = vm->vm_ssize;
742 	} else if (p->p_state == PRS_ZOMBIE)
743 		kp->ki_stat = SZOMB;
744 	if (kp->ki_flag & P_INMEM)
745 		kp->ki_sflag = PS_INMEM;
746 	else
747 		kp->ki_sflag = 0;
748 	/* Calculate legacy swtime as seconds since 'swtick'. */
749 	kp->ki_swtime = (ticks - p->p_swtick) / hz;
750 	kp->ki_pid = p->p_pid;
751 	kp->ki_nice = p->p_nice;
752 	rufetch(p, &kp->ki_rusage);
753 	kp->ki_runtime = cputick2usec(p->p_rux.rux_runtime);
754 	PROC_SUNLOCK(p);
755 	if ((p->p_flag & P_INMEM) && p->p_stats != NULL) {
756 		kp->ki_start = p->p_stats->p_start;
757 		timevaladd(&kp->ki_start, &boottime);
758 		PROC_SLOCK(p);
759 		calcru(p, &kp->ki_rusage.ru_utime, &kp->ki_rusage.ru_stime);
760 		PROC_SUNLOCK(p);
761 		calccru(p, &kp->ki_childutime, &kp->ki_childstime);
762 
763 		/* Some callers want child-times in a single value */
764 		kp->ki_childtime = kp->ki_childstime;
765 		timevaladd(&kp->ki_childtime, &kp->ki_childutime);
766 	}
767 	tp = NULL;
768 	if (p->p_pgrp) {
769 		kp->ki_pgid = p->p_pgrp->pg_id;
770 		kp->ki_jobc = p->p_pgrp->pg_jobc;
771 		sp = p->p_pgrp->pg_session;
772 
773 		if (sp != NULL) {
774 			kp->ki_sid = sp->s_sid;
775 			SESS_LOCK(sp);
776 			strlcpy(kp->ki_login, sp->s_login,
777 			    sizeof(kp->ki_login));
778 			if (sp->s_ttyvp)
779 				kp->ki_kiflag |= KI_CTTY;
780 			if (SESS_LEADER(p))
781 				kp->ki_kiflag |= KI_SLEADER;
782 			tp = sp->s_ttyp;
783 			SESS_UNLOCK(sp);
784 		}
785 	}
786 	if ((p->p_flag & P_CONTROLT) && tp != NULL) {
787 		kp->ki_tdev = dev2udev(tp->t_dev);
788 		kp->ki_tpgid = tp->t_pgrp ? tp->t_pgrp->pg_id : NO_PID;
789 		if (tp->t_session)
790 			kp->ki_tsid = tp->t_session->s_sid;
791 	} else
792 		kp->ki_tdev = NODEV;
793 	if (p->p_comm[0] != '\0')
794 		strlcpy(kp->ki_comm, p->p_comm, sizeof(kp->ki_comm));
795 	if (p->p_sysent && p->p_sysent->sv_name != NULL &&
796 	    p->p_sysent->sv_name[0] != '\0')
797 		strlcpy(kp->ki_emul, p->p_sysent->sv_name, sizeof(kp->ki_emul));
798 	kp->ki_siglist = p->p_siglist;
799 	kp->ki_xstat = p->p_xstat;
800 	kp->ki_acflag = p->p_acflag;
801 	kp->ki_lock = p->p_lock;
802 	if (p->p_pptr)
803 		kp->ki_ppid = p->p_pptr->p_pid;
804 }
805 
806 /*
807  * Fill in information that is thread specific.  Must be called with p_slock
808  * locked.  If 'preferthread' is set, overwrite certain process-related
809  * fields that are maintained for both threads and processes.
810  */
811 static void
812 fill_kinfo_thread(struct thread *td, struct kinfo_proc *kp, int preferthread)
813 {
814 	struct proc *p;
815 
816 	p = td->td_proc;
817 	PROC_LOCK_ASSERT(p, MA_OWNED);
818 
819 	thread_lock(td);
820 	if (td->td_wmesg != NULL)
821 		strlcpy(kp->ki_wmesg, td->td_wmesg, sizeof(kp->ki_wmesg));
822 	else
823 		bzero(kp->ki_wmesg, sizeof(kp->ki_wmesg));
824 	if (td->td_name[0] != '\0')
825 		strlcpy(kp->ki_ocomm, td->td_name, sizeof(kp->ki_ocomm));
826 	if (TD_ON_LOCK(td)) {
827 		kp->ki_kiflag |= KI_LOCKBLOCK;
828 		strlcpy(kp->ki_lockname, td->td_lockname,
829 		    sizeof(kp->ki_lockname));
830 	} else {
831 		kp->ki_kiflag &= ~KI_LOCKBLOCK;
832 		bzero(kp->ki_lockname, sizeof(kp->ki_lockname));
833 	}
834 
835 	if (p->p_state == PRS_NORMAL) { /* approximate. */
836 		if (TD_ON_RUNQ(td) ||
837 		    TD_CAN_RUN(td) ||
838 		    TD_IS_RUNNING(td)) {
839 			kp->ki_stat = SRUN;
840 		} else if (P_SHOULDSTOP(p)) {
841 			kp->ki_stat = SSTOP;
842 		} else if (TD_IS_SLEEPING(td)) {
843 			kp->ki_stat = SSLEEP;
844 		} else if (TD_ON_LOCK(td)) {
845 			kp->ki_stat = SLOCK;
846 		} else {
847 			kp->ki_stat = SWAIT;
848 		}
849 	} else if (p->p_state == PRS_ZOMBIE) {
850 		kp->ki_stat = SZOMB;
851 	} else {
852 		kp->ki_stat = SIDL;
853 	}
854 
855 	/* Things in the thread */
856 	kp->ki_wchan = td->td_wchan;
857 	kp->ki_pri.pri_level = td->td_priority;
858 	kp->ki_pri.pri_native = td->td_base_pri;
859 	kp->ki_lastcpu = td->td_lastcpu;
860 	kp->ki_oncpu = td->td_oncpu;
861 	kp->ki_tdflags = td->td_flags;
862 	kp->ki_tid = td->td_tid;
863 	kp->ki_numthreads = p->p_numthreads;
864 	kp->ki_pcb = td->td_pcb;
865 	kp->ki_kstack = (void *)td->td_kstack;
866 	kp->ki_pctcpu = sched_pctcpu(td);
867 	kp->ki_estcpu = td->td_estcpu;
868 	kp->ki_slptime = (ticks - td->td_slptick) / hz;
869 	kp->ki_pri.pri_class = td->td_pri_class;
870 	kp->ki_pri.pri_user = td->td_user_pri;
871 
872 	if (preferthread)
873 		kp->ki_runtime = cputick2usec(td->td_runtime);
874 
875 	/* We can't get this anymore but ps etc never used it anyway. */
876 	kp->ki_rqindex = 0;
877 
878 	SIGSETOR(kp->ki_siglist, td->td_siglist);
879 	kp->ki_sigmask = td->td_sigmask;
880 	thread_unlock(td);
881 }
882 
883 /*
884  * Fill in a kinfo_proc structure for the specified process.
885  * Must be called with the target process locked.
886  */
887 void
888 fill_kinfo_proc(struct proc *p, struct kinfo_proc *kp)
889 {
890 
891 	fill_kinfo_proc_only(p, kp);
892 	if (FIRST_THREAD_IN_PROC(p) != NULL)
893 		fill_kinfo_thread(FIRST_THREAD_IN_PROC(p), kp, 0);
894 }
895 
896 struct pstats *
897 pstats_alloc(void)
898 {
899 
900 	return (malloc(sizeof(struct pstats), M_SUBPROC, M_ZERO|M_WAITOK));
901 }
902 
903 /*
904  * Copy parts of p_stats; zero the rest of p_stats (statistics).
905  */
906 void
907 pstats_fork(struct pstats *src, struct pstats *dst)
908 {
909 
910 	bzero(&dst->pstat_startzero,
911 	    __rangeof(struct pstats, pstat_startzero, pstat_endzero));
912 	bcopy(&src->pstat_startcopy, &dst->pstat_startcopy,
913 	    __rangeof(struct pstats, pstat_startcopy, pstat_endcopy));
914 }
915 
916 void
917 pstats_free(struct pstats *ps)
918 {
919 
920 	free(ps, M_SUBPROC);
921 }
922 
923 /*
924  * Locate a zombie process by number
925  */
926 struct proc *
927 zpfind(pid_t pid)
928 {
929 	struct proc *p;
930 
931 	sx_slock(&allproc_lock);
932 	LIST_FOREACH(p, &zombproc, p_list)
933 		if (p->p_pid == pid) {
934 			PROC_LOCK(p);
935 			break;
936 		}
937 	sx_sunlock(&allproc_lock);
938 	return (p);
939 }
940 
941 #define KERN_PROC_ZOMBMASK	0x3
942 #define KERN_PROC_NOTHREADS	0x4
943 
944 /*
945  * Must be called with the process locked and will return with it unlocked.
946  */
947 static int
948 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int flags)
949 {
950 	struct thread *td;
951 	struct kinfo_proc kinfo_proc;
952 	int error = 0;
953 	struct proc *np;
954 	pid_t pid = p->p_pid;
955 
956 	PROC_LOCK_ASSERT(p, MA_OWNED);
957 
958 	fill_kinfo_proc_only(p, &kinfo_proc);
959 	if (flags & KERN_PROC_NOTHREADS) {
960 		if (FIRST_THREAD_IN_PROC(p) != NULL)
961 			fill_kinfo_thread(FIRST_THREAD_IN_PROC(p),
962 			    &kinfo_proc, 0);
963 		error = SYSCTL_OUT(req, (caddr_t)&kinfo_proc,
964 				   sizeof(kinfo_proc));
965 	} else {
966 		if (FIRST_THREAD_IN_PROC(p) != NULL)
967 			FOREACH_THREAD_IN_PROC(p, td) {
968 				fill_kinfo_thread(td, &kinfo_proc, 1);
969 				error = SYSCTL_OUT(req, (caddr_t)&kinfo_proc,
970 						   sizeof(kinfo_proc));
971 				if (error)
972 					break;
973 			}
974 		else
975 			error = SYSCTL_OUT(req, (caddr_t)&kinfo_proc,
976 					   sizeof(kinfo_proc));
977 	}
978 	PROC_UNLOCK(p);
979 	if (error)
980 		return (error);
981 	if (flags & KERN_PROC_ZOMBMASK)
982 		np = zpfind(pid);
983 	else {
984 		if (pid == 0)
985 			return (0);
986 		np = pfind(pid);
987 	}
988 	if (np == NULL)
989 		return EAGAIN;
990 	if (np != p) {
991 		PROC_UNLOCK(np);
992 		return EAGAIN;
993 	}
994 	PROC_UNLOCK(np);
995 	return (0);
996 }
997 
998 static int
999 sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
1000 {
1001 	int *name = (int*) arg1;
1002 	u_int namelen = arg2;
1003 	struct proc *p;
1004 	int flags, doingzomb, oid_number;
1005 	int error = 0;
1006 
1007 	oid_number = oidp->oid_number;
1008 	if (oid_number != KERN_PROC_ALL &&
1009 	    (oid_number & KERN_PROC_INC_THREAD) == 0)
1010 		flags = KERN_PROC_NOTHREADS;
1011 	else {
1012 		flags = 0;
1013 		oid_number &= ~KERN_PROC_INC_THREAD;
1014 	}
1015 	if (oid_number == KERN_PROC_PID) {
1016 		if (namelen != 1)
1017 			return (EINVAL);
1018 		error = sysctl_wire_old_buffer(req, 0);
1019 		if (error)
1020 			return (error);
1021 		p = pfind((pid_t)name[0]);
1022 		if (!p)
1023 			return (ESRCH);
1024 		if ((error = p_cansee(curthread, p))) {
1025 			PROC_UNLOCK(p);
1026 			return (error);
1027 		}
1028 		error = sysctl_out_proc(p, req, flags);
1029 		return (error);
1030 	}
1031 
1032 	switch (oid_number) {
1033 	case KERN_PROC_ALL:
1034 		if (namelen != 0)
1035 			return (EINVAL);
1036 		break;
1037 	case KERN_PROC_PROC:
1038 		if (namelen != 0 && namelen != 1)
1039 			return (EINVAL);
1040 		break;
1041 	default:
1042 		if (namelen != 1)
1043 			return (EINVAL);
1044 		break;
1045 	}
1046 
1047 	if (!req->oldptr) {
1048 		/* overestimate by 5 procs */
1049 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
1050 		if (error)
1051 			return (error);
1052 	}
1053 	error = sysctl_wire_old_buffer(req, 0);
1054 	if (error != 0)
1055 		return (error);
1056 	sx_slock(&allproc_lock);
1057 	for (doingzomb=0 ; doingzomb < 2 ; doingzomb++) {
1058 		if (!doingzomb)
1059 			p = LIST_FIRST(&allproc);
1060 		else
1061 			p = LIST_FIRST(&zombproc);
1062 		for (; p != 0; p = LIST_NEXT(p, p_list)) {
1063 			/*
1064 			 * Skip embryonic processes.
1065 			 */
1066 			PROC_SLOCK(p);
1067 			if (p->p_state == PRS_NEW) {
1068 				PROC_SUNLOCK(p);
1069 				continue;
1070 			}
1071 			PROC_SUNLOCK(p);
1072 			PROC_LOCK(p);
1073 			KASSERT(p->p_ucred != NULL,
1074 			    ("process credential is NULL for non-NEW proc"));
1075 			/*
1076 			 * Show a user only appropriate processes.
1077 			 */
1078 			if (p_cansee(curthread, p)) {
1079 				PROC_UNLOCK(p);
1080 				continue;
1081 			}
1082 			/*
1083 			 * TODO - make more efficient (see notes below).
1084 			 * do by session.
1085 			 */
1086 			switch (oid_number) {
1087 
1088 			case KERN_PROC_GID:
1089 				if (p->p_ucred->cr_gid != (gid_t)name[0]) {
1090 					PROC_UNLOCK(p);
1091 					continue;
1092 				}
1093 				break;
1094 
1095 			case KERN_PROC_PGRP:
1096 				/* could do this by traversing pgrp */
1097 				if (p->p_pgrp == NULL ||
1098 				    p->p_pgrp->pg_id != (pid_t)name[0]) {
1099 					PROC_UNLOCK(p);
1100 					continue;
1101 				}
1102 				break;
1103 
1104 			case KERN_PROC_RGID:
1105 				if (p->p_ucred->cr_rgid != (gid_t)name[0]) {
1106 					PROC_UNLOCK(p);
1107 					continue;
1108 				}
1109 				break;
1110 
1111 			case KERN_PROC_SESSION:
1112 				if (p->p_session == NULL ||
1113 				    p->p_session->s_sid != (pid_t)name[0]) {
1114 					PROC_UNLOCK(p);
1115 					continue;
1116 				}
1117 				break;
1118 
1119 			case KERN_PROC_TTY:
1120 				if ((p->p_flag & P_CONTROLT) == 0 ||
1121 				    p->p_session == NULL) {
1122 					PROC_UNLOCK(p);
1123 					continue;
1124 				}
1125 				SESS_LOCK(p->p_session);
1126 				if (p->p_session->s_ttyp == NULL ||
1127 				    dev2udev(p->p_session->s_ttyp->t_dev) !=
1128 				    (dev_t)name[0]) {
1129 					SESS_UNLOCK(p->p_session);
1130 					PROC_UNLOCK(p);
1131 					continue;
1132 				}
1133 				SESS_UNLOCK(p->p_session);
1134 				break;
1135 
1136 			case KERN_PROC_UID:
1137 				if (p->p_ucred->cr_uid != (uid_t)name[0]) {
1138 					PROC_UNLOCK(p);
1139 					continue;
1140 				}
1141 				break;
1142 
1143 			case KERN_PROC_RUID:
1144 				if (p->p_ucred->cr_ruid != (uid_t)name[0]) {
1145 					PROC_UNLOCK(p);
1146 					continue;
1147 				}
1148 				break;
1149 
1150 			case KERN_PROC_PROC:
1151 				break;
1152 
1153 			default:
1154 				break;
1155 
1156 			}
1157 
1158 			error = sysctl_out_proc(p, req, flags | doingzomb);
1159 			if (error) {
1160 				sx_sunlock(&allproc_lock);
1161 				return (error);
1162 			}
1163 		}
1164 	}
1165 	sx_sunlock(&allproc_lock);
1166 	return (0);
1167 }
1168 
1169 struct pargs *
1170 pargs_alloc(int len)
1171 {
1172 	struct pargs *pa;
1173 
1174 	MALLOC(pa, struct pargs *, sizeof(struct pargs) + len, M_PARGS,
1175 		M_WAITOK);
1176 	refcount_init(&pa->ar_ref, 1);
1177 	pa->ar_length = len;
1178 	return (pa);
1179 }
1180 
1181 static void
1182 pargs_free(struct pargs *pa)
1183 {
1184 
1185 	FREE(pa, M_PARGS);
1186 }
1187 
1188 void
1189 pargs_hold(struct pargs *pa)
1190 {
1191 
1192 	if (pa == NULL)
1193 		return;
1194 	refcount_acquire(&pa->ar_ref);
1195 }
1196 
1197 void
1198 pargs_drop(struct pargs *pa)
1199 {
1200 
1201 	if (pa == NULL)
1202 		return;
1203 	if (refcount_release(&pa->ar_ref))
1204 		pargs_free(pa);
1205 }
1206 
1207 /*
1208  * This sysctl allows a process to retrieve the argument list or process
1209  * title for another process without groping around in the address space
1210  * of the other process.  It also allow a process to set its own "process
1211  * title to a string of its own choice.
1212  */
1213 static int
1214 sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
1215 {
1216 	int *name = (int*) arg1;
1217 	u_int namelen = arg2;
1218 	struct pargs *newpa, *pa;
1219 	struct proc *p;
1220 	int error = 0;
1221 
1222 	if (namelen != 1)
1223 		return (EINVAL);
1224 
1225 	p = pfind((pid_t)name[0]);
1226 	if (!p)
1227 		return (ESRCH);
1228 
1229 	if ((error = p_cansee(curthread, p)) != 0) {
1230 		PROC_UNLOCK(p);
1231 		return (error);
1232 	}
1233 
1234 	if (req->newptr && curproc != p) {
1235 		PROC_UNLOCK(p);
1236 		return (EPERM);
1237 	}
1238 
1239 	pa = p->p_args;
1240 	pargs_hold(pa);
1241 	PROC_UNLOCK(p);
1242 	if (req->oldptr != NULL && pa != NULL)
1243 		error = SYSCTL_OUT(req, pa->ar_args, pa->ar_length);
1244 	pargs_drop(pa);
1245 	if (error != 0 || req->newptr == NULL)
1246 		return (error);
1247 
1248 	if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
1249 		return (ENOMEM);
1250 	newpa = pargs_alloc(req->newlen);
1251 	error = SYSCTL_IN(req, newpa->ar_args, req->newlen);
1252 	if (error != 0) {
1253 		pargs_free(newpa);
1254 		return (error);
1255 	}
1256 	PROC_LOCK(p);
1257 	pa = p->p_args;
1258 	p->p_args = newpa;
1259 	PROC_UNLOCK(p);
1260 	pargs_drop(pa);
1261 	return (0);
1262 }
1263 
1264 /*
1265  * This sysctl allows a process to retrieve the path of the executable for
1266  * itself or another process.
1267  */
1268 static int
1269 sysctl_kern_proc_pathname(SYSCTL_HANDLER_ARGS)
1270 {
1271 	pid_t *pidp = (pid_t *)arg1;
1272 	unsigned int arglen = arg2;
1273 	struct proc *p;
1274 	struct vnode *vp;
1275 	char *retbuf, *freebuf;
1276 	int error;
1277 
1278 	if (arglen != 1)
1279 		return (EINVAL);
1280 	if (*pidp == -1) {	/* -1 means this process */
1281 		p = req->td->td_proc;
1282 	} else {
1283 		p = pfind(*pidp);
1284 		if (p == NULL)
1285 			return (ESRCH);
1286 		if ((error = p_cansee(curthread, p)) != 0) {
1287 			PROC_UNLOCK(p);
1288 			return (error);
1289 		}
1290 	}
1291 
1292 	vp = p->p_textvp;
1293 	if (vp == NULL) {
1294 		if (*pidp != -1)
1295 			PROC_UNLOCK(p);
1296 		return (0);
1297 	}
1298 	vref(vp);
1299 	if (*pidp != -1)
1300 		PROC_UNLOCK(p);
1301 	error = vn_fullpath(req->td, vp, &retbuf, &freebuf);
1302 	vrele(vp);
1303 	if (error)
1304 		return (error);
1305 	error = SYSCTL_OUT(req, retbuf, strlen(retbuf) + 1);
1306 	free(freebuf, M_TEMP);
1307 	return (error);
1308 }
1309 
1310 static int
1311 sysctl_kern_proc_sv_name(SYSCTL_HANDLER_ARGS)
1312 {
1313 	struct proc *p;
1314 	char *sv_name;
1315 	int *name;
1316 	int namelen;
1317 	int error;
1318 
1319 	namelen = arg2;
1320 	if (namelen != 1)
1321 		return (EINVAL);
1322 
1323 	name = (int *)arg1;
1324 	if ((p = pfind((pid_t)name[0])) == NULL)
1325 		return (ESRCH);
1326 	if ((error = p_cansee(curthread, p))) {
1327 		PROC_UNLOCK(p);
1328 		return (error);
1329 	}
1330 	sv_name = p->p_sysent->sv_name;
1331 	PROC_UNLOCK(p);
1332 	return (sysctl_handle_string(oidp, sv_name, 0, req));
1333 }
1334 
1335 static int
1336 sysctl_kern_proc_vmmap(SYSCTL_HANDLER_ARGS)
1337 {
1338 	vm_map_entry_t entry, tmp_entry;
1339 	unsigned int last_timestamp;
1340 	char *fullpath, *freepath;
1341 	struct kinfo_vmentry *kve;
1342 	int error, *name;
1343 	struct vnode *vp;
1344 	struct proc *p;
1345 	vm_map_t map;
1346 
1347 	name = (int *)arg1;
1348 	if ((p = pfind((pid_t)name[0])) == NULL)
1349 		return (ESRCH);
1350 	if (p->p_flag & P_WEXIT) {
1351 		PROC_UNLOCK(p);
1352 		return (ESRCH);
1353 	}
1354 	if ((error = p_candebug(curthread, p))) {
1355 		PROC_UNLOCK(p);
1356 		return (error);
1357 	}
1358 	_PHOLD(p);
1359 	PROC_UNLOCK(p);
1360 
1361 	kve = malloc(sizeof(*kve), M_TEMP, M_WAITOK);
1362 
1363 	map = &p->p_vmspace->vm_map;	/* XXXRW: More locking required? */
1364 	vm_map_lock_read(map);
1365 	for (entry = map->header.next; entry != &map->header;
1366 	    entry = entry->next) {
1367 		vm_object_t obj, tobj, lobj;
1368 		vm_offset_t addr;
1369 		int vfslocked;
1370 
1371 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
1372 			continue;
1373 
1374 		bzero(kve, sizeof(*kve));
1375 		kve->kve_structsize = sizeof(*kve);
1376 
1377 		kve->kve_private_resident = 0;
1378 		obj = entry->object.vm_object;
1379 		if (obj != NULL) {
1380 			VM_OBJECT_LOCK(obj);
1381 			if (obj->shadow_count == 1)
1382 				kve->kve_private_resident =
1383 				    obj->resident_page_count;
1384 		}
1385 		kve->kve_resident = 0;
1386 		addr = entry->start;
1387 		while (addr < entry->end) {
1388 			if (pmap_extract(map->pmap, addr))
1389 				kve->kve_resident++;
1390 			addr += PAGE_SIZE;
1391 		}
1392 
1393 		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
1394 			if (tobj != obj)
1395 				VM_OBJECT_LOCK(tobj);
1396 			if (lobj != obj)
1397 				VM_OBJECT_UNLOCK(lobj);
1398 			lobj = tobj;
1399 		}
1400 
1401 		freepath = NULL;
1402 		fullpath = "";
1403 		if (lobj) {
1404 			vp = NULL;
1405 			switch(lobj->type) {
1406 			case OBJT_DEFAULT:
1407 				kve->kve_type = KVME_TYPE_DEFAULT;
1408 				break;
1409 			case OBJT_VNODE:
1410 				kve->kve_type = KVME_TYPE_VNODE;
1411 				vp = lobj->handle;
1412 				vref(vp);
1413 				break;
1414 			case OBJT_SWAP:
1415 				kve->kve_type = KVME_TYPE_SWAP;
1416 				break;
1417 			case OBJT_DEVICE:
1418 				kve->kve_type = KVME_TYPE_DEVICE;
1419 				break;
1420 			case OBJT_PHYS:
1421 				kve->kve_type = KVME_TYPE_PHYS;
1422 				break;
1423 			case OBJT_DEAD:
1424 				kve->kve_type = KVME_TYPE_DEAD;
1425 				break;
1426 			default:
1427 				kve->kve_type = KVME_TYPE_UNKNOWN;
1428 				break;
1429 			}
1430 			if (lobj != obj)
1431 				VM_OBJECT_UNLOCK(lobj);
1432 
1433 			kve->kve_ref_count = obj->ref_count;
1434 			kve->kve_shadow_count = obj->shadow_count;
1435 			VM_OBJECT_UNLOCK(obj);
1436 			if (vp != NULL) {
1437 				vfslocked = VFS_LOCK_GIANT(vp->v_mount);
1438 				vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
1439 				vn_fullpath(curthread, vp, &fullpath,
1440 				    &freepath);
1441 				vput(vp);
1442 				VFS_UNLOCK_GIANT(vfslocked);
1443 			}
1444 		} else {
1445 			kve->kve_type = KVME_TYPE_NONE;
1446 			kve->kve_ref_count = 0;
1447 			kve->kve_shadow_count = 0;
1448 		}
1449 
1450 		kve->kve_start = (void*)entry->start;
1451 		kve->kve_end = (void*)entry->end;
1452 
1453 		if (entry->protection & VM_PROT_READ)
1454 			kve->kve_protection |= KVME_PROT_READ;
1455 		if (entry->protection & VM_PROT_WRITE)
1456 			kve->kve_protection |= KVME_PROT_WRITE;
1457 		if (entry->protection & VM_PROT_EXECUTE)
1458 			kve->kve_protection |= KVME_PROT_EXEC;
1459 
1460 		if (entry->eflags & MAP_ENTRY_COW)
1461 			kve->kve_flags |= KVME_FLAG_COW;
1462 		if (entry->eflags & MAP_ENTRY_NEEDS_COPY)
1463 			kve->kve_flags |= KVME_FLAG_NEEDS_COPY;
1464 
1465 		strlcpy(kve->kve_path, fullpath, sizeof(kve->kve_path));
1466 		if (freepath != NULL)
1467 			free(freepath, M_TEMP);
1468 
1469 		last_timestamp = map->timestamp;
1470 		vm_map_unlock_read(map);
1471 		error = SYSCTL_OUT(req, kve, sizeof(*kve));
1472 		vm_map_lock_read(map);
1473 		if (error)
1474 			break;
1475 		if (last_timestamp + 1 != map->timestamp) {
1476 			vm_map_lookup_entry(map, addr - 1, &tmp_entry);
1477 			entry = tmp_entry;
1478 		}
1479 	}
1480 	vm_map_unlock_read(map);
1481 	PRELE(p);
1482 	free(kve, M_TEMP);
1483 	return (error);
1484 }
1485 
1486 #if defined(STACK) || defined(DDB)
1487 static int
1488 sysctl_kern_proc_kstack(SYSCTL_HANDLER_ARGS)
1489 {
1490 	struct kinfo_kstack *kkstp;
1491 	int error, i, *name, numthreads;
1492 	lwpid_t *lwpidarray;
1493 	struct thread *td;
1494 	struct stack *st;
1495 	struct sbuf sb;
1496 	struct proc *p;
1497 
1498 	name = (int *)arg1;
1499 	if ((p = pfind((pid_t)name[0])) == NULL)
1500 		return (ESRCH);
1501 	/* XXXRW: Not clear ESRCH is the right error during proc execve(). */
1502 	if (p->p_flag & P_WEXIT || p->p_flag & P_INEXEC) {
1503 		PROC_UNLOCK(p);
1504 		return (ESRCH);
1505 	}
1506 	if ((error = p_candebug(curthread, p))) {
1507 		PROC_UNLOCK(p);
1508 		return (error);
1509 	}
1510 	_PHOLD(p);
1511 	PROC_UNLOCK(p);
1512 
1513 	kkstp = malloc(sizeof(*kkstp), M_TEMP, M_WAITOK);
1514 	st = stack_create();
1515 
1516 	lwpidarray = NULL;
1517 	numthreads = 0;
1518 	PROC_LOCK(p);
1519 repeat:
1520 	if (numthreads < p->p_numthreads) {
1521 		if (lwpidarray != NULL) {
1522 			free(lwpidarray, M_TEMP);
1523 			lwpidarray = NULL;
1524 		}
1525 		numthreads = p->p_numthreads;
1526 		PROC_UNLOCK(p);
1527 		lwpidarray = malloc(sizeof(*lwpidarray) * numthreads, M_TEMP,
1528 		    M_WAITOK | M_ZERO);
1529 		PROC_LOCK(p);
1530 		goto repeat;
1531 	}
1532 	i = 0;
1533 
1534 	/*
1535 	 * XXXRW: During the below loop, execve(2) and countless other sorts
1536 	 * of changes could have taken place.  Should we check to see if the
1537 	 * vmspace has been replaced, or the like, in order to prevent
1538 	 * giving a snapshot that spans, say, execve(2), with some threads
1539 	 * before and some after?  Among other things, the credentials could
1540 	 * have changed, in which case the right to extract debug info might
1541 	 * no longer be assured.
1542 	 */
1543 	FOREACH_THREAD_IN_PROC(p, td) {
1544 		KASSERT(i < numthreads,
1545 		    ("sysctl_kern_proc_kstack: numthreads"));
1546 		lwpidarray[i] = td->td_tid;
1547 		i++;
1548 	}
1549 	numthreads = i;
1550 	for (i = 0; i < numthreads; i++) {
1551 		td = thread_find(p, lwpidarray[i]);
1552 		if (td == NULL) {
1553 			continue;
1554 		}
1555 		bzero(kkstp, sizeof(*kkstp));
1556 		(void)sbuf_new(&sb, kkstp->kkst_trace,
1557 		    sizeof(kkstp->kkst_trace), SBUF_FIXEDLEN);
1558 		thread_lock(td);
1559 		kkstp->kkst_tid = td->td_tid;
1560 		if (TD_IS_SWAPPED(td))
1561 			kkstp->kkst_state = KKST_STATE_SWAPPED;
1562 		else if (TD_IS_RUNNING(td))
1563 			kkstp->kkst_state = KKST_STATE_RUNNING;
1564 		else {
1565 			kkstp->kkst_state = KKST_STATE_STACKOK;
1566 			stack_save_td(st, td);
1567 		}
1568 		thread_unlock(td);
1569 		PROC_UNLOCK(p);
1570 		stack_sbuf_print(&sb, st);
1571 		sbuf_finish(&sb);
1572 		sbuf_delete(&sb);
1573 		error = SYSCTL_OUT(req, kkstp, sizeof(*kkstp));
1574 		PROC_LOCK(p);
1575 		if (error)
1576 			break;
1577 	}
1578 	_PRELE(p);
1579 	PROC_UNLOCK(p);
1580 	if (lwpidarray != NULL)
1581 		free(lwpidarray, M_TEMP);
1582 	stack_destroy(st);
1583 	free(kkstp, M_TEMP);
1584 	return (error);
1585 }
1586 #endif
1587 
1588 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
1589 
1590 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
1591 	0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
1592 
1593 static SYSCTL_NODE(_kern_proc, KERN_PROC_GID, gid, CTLFLAG_RD,
1594 	sysctl_kern_proc, "Process table");
1595 
1596 static SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
1597 	sysctl_kern_proc, "Process table");
1598 
1599 static SYSCTL_NODE(_kern_proc, KERN_PROC_RGID, rgid, CTLFLAG_RD,
1600 	sysctl_kern_proc, "Process table");
1601 
1602 static SYSCTL_NODE(_kern_proc, KERN_PROC_SESSION, sid, CTLFLAG_RD,
1603 	sysctl_kern_proc, "Process table");
1604 
1605 static SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
1606 	sysctl_kern_proc, "Process table");
1607 
1608 static SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
1609 	sysctl_kern_proc, "Process table");
1610 
1611 static SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
1612 	sysctl_kern_proc, "Process table");
1613 
1614 static SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
1615 	sysctl_kern_proc, "Process table");
1616 
1617 static SYSCTL_NODE(_kern_proc, KERN_PROC_PROC, proc, CTLFLAG_RD,
1618 	sysctl_kern_proc, "Return process table, no threads");
1619 
1620 static SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args,
1621 	CTLFLAG_RW | CTLFLAG_ANYBODY,
1622 	sysctl_kern_proc_args, "Process argument list");
1623 
1624 static SYSCTL_NODE(_kern_proc, KERN_PROC_PATHNAME, pathname, CTLFLAG_RD,
1625 	sysctl_kern_proc_pathname, "Process executable path");
1626 
1627 static SYSCTL_NODE(_kern_proc, KERN_PROC_SV_NAME, sv_name, CTLFLAG_RD,
1628 	sysctl_kern_proc_sv_name, "Process syscall vector name (ABI type)");
1629 
1630 static SYSCTL_NODE(_kern_proc, (KERN_PROC_GID | KERN_PROC_INC_THREAD), gid_td,
1631 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1632 
1633 static SYSCTL_NODE(_kern_proc, (KERN_PROC_PGRP | KERN_PROC_INC_THREAD), pgrp_td,
1634 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1635 
1636 static SYSCTL_NODE(_kern_proc, (KERN_PROC_RGID | KERN_PROC_INC_THREAD), rgid_td,
1637 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1638 
1639 static SYSCTL_NODE(_kern_proc, (KERN_PROC_SESSION | KERN_PROC_INC_THREAD),
1640 	sid_td, CTLFLAG_RD, sysctl_kern_proc, "Process table");
1641 
1642 static SYSCTL_NODE(_kern_proc, (KERN_PROC_TTY | KERN_PROC_INC_THREAD), tty_td,
1643 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1644 
1645 static SYSCTL_NODE(_kern_proc, (KERN_PROC_UID | KERN_PROC_INC_THREAD), uid_td,
1646 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1647 
1648 static SYSCTL_NODE(_kern_proc, (KERN_PROC_RUID | KERN_PROC_INC_THREAD), ruid_td,
1649 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1650 
1651 static SYSCTL_NODE(_kern_proc, (KERN_PROC_PID | KERN_PROC_INC_THREAD), pid_td,
1652 	CTLFLAG_RD, sysctl_kern_proc, "Process table");
1653 
1654 static SYSCTL_NODE(_kern_proc, (KERN_PROC_PROC | KERN_PROC_INC_THREAD), proc_td,
1655 	CTLFLAG_RD, sysctl_kern_proc, "Return process table, no threads");
1656 
1657 static SYSCTL_NODE(_kern_proc, KERN_PROC_VMMAP, vmmap, CTLFLAG_RD,
1658 	sysctl_kern_proc_vmmap, "Process vm map entries");
1659 
1660 #if defined(STACK) || defined(DDB)
1661 static SYSCTL_NODE(_kern_proc, KERN_PROC_KSTACK, kstack, CTLFLAG_RD,
1662 	sysctl_kern_proc_kstack, "Process kernel stacks");
1663 #endif
1664