xref: /dragonfly/sys/kern/kern_proc.c (revision 19fe1c42)
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  * $DragonFly: src/sys/kern/kern_proc.c,v 1.45 2008/06/12 23:25:02 dillon Exp $
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/sysctl.h>
42 #include <sys/malloc.h>
43 #include <sys/proc.h>
44 #include <sys/jail.h>
45 #include <sys/filedesc.h>
46 #include <sys/tty.h>
47 #include <sys/signalvar.h>
48 #include <sys/spinlock.h>
49 #include <vm/vm.h>
50 #include <sys/lock.h>
51 #include <vm/pmap.h>
52 #include <vm/vm_map.h>
53 #include <sys/user.h>
54 #include <machine/smp.h>
55 
56 #include <sys/spinlock2.h>
57 
58 static MALLOC_DEFINE(M_PGRP, "pgrp", "process group header");
59 MALLOC_DEFINE(M_SESSION, "session", "session header");
60 MALLOC_DEFINE(M_PROC, "proc", "Proc structures");
61 MALLOC_DEFINE(M_LWP, "lwp", "lwp structures");
62 MALLOC_DEFINE(M_SUBPROC, "subproc", "Proc sub-structures");
63 
64 int ps_showallprocs = 1;
65 static int ps_showallthreads = 1;
66 SYSCTL_INT(_security, OID_AUTO, ps_showallprocs, CTLFLAG_RW,
67     &ps_showallprocs, 0,
68     "Unprivileged processes can see proccesses with different UID/GID");
69 SYSCTL_INT(_security, OID_AUTO, ps_showallthreads, CTLFLAG_RW,
70     &ps_showallthreads, 0,
71     "Unprivileged processes can see kernel threads");
72 
73 static void pgdelete(struct pgrp *);
74 static void orphanpg(struct pgrp *pg);
75 static pid_t proc_getnewpid_locked(int random_offset);
76 
77 /*
78  * Other process lists
79  */
80 struct pidhashhead *pidhashtbl;
81 u_long pidhash;
82 struct pgrphashhead *pgrphashtbl;
83 u_long pgrphash;
84 struct proclist allproc;
85 struct proclist zombproc;
86 struct spinlock allproc_spin;
87 
88 /*
89  * Random component to nextpid generation.  We mix in a random factor to make
90  * it a little harder to predict.  We sanity check the modulus value to avoid
91  * doing it in critical paths.  Don't let it be too small or we pointlessly
92  * waste randomness entropy, and don't let it be impossibly large.  Using a
93  * modulus that is too big causes a LOT more process table scans and slows
94  * down fork processing as the pidchecked caching is defeated.
95  */
96 static int randompid = 0;
97 
98 static int
99 sysctl_kern_randompid(SYSCTL_HANDLER_ARGS)
100 {
101 	int error, pid;
102 
103 	pid = randompid;
104 	error = sysctl_handle_int(oidp, &pid, 0, req);
105 	if (error || !req->newptr)
106 		return (error);
107 	if (pid < 0 || pid > PID_MAX - 100)     /* out of range */
108 		pid = PID_MAX - 100;
109 	else if (pid < 2)                       /* NOP */
110 		pid = 0;
111 	else if (pid < 100)                     /* Make it reasonable */
112 		pid = 100;
113 	randompid = pid;
114 	return (error);
115 }
116 
117 SYSCTL_PROC(_kern, OID_AUTO, randompid, CTLTYPE_INT|CTLFLAG_RW,
118 	    0, 0, sysctl_kern_randompid, "I", "Random PID modulus");
119 
120 /*
121  * Initialize global process hashing structures.
122  */
123 void
124 procinit(void)
125 {
126 	LIST_INIT(&allproc);
127 	LIST_INIT(&zombproc);
128 	spin_init(&allproc_spin);
129 	lwkt_init();
130 	pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash);
131 	pgrphashtbl = hashinit(maxproc / 4, M_PROC, &pgrphash);
132 	uihashinit();
133 }
134 
135 /*
136  * Is p an inferior of the current process?
137  */
138 int
139 inferior(struct proc *p)
140 {
141 	for (; p != curproc; p = p->p_pptr)
142 		if (p->p_pid == 0)
143 			return (0);
144 	return (1);
145 }
146 
147 /*
148  * Locate a process by number
149  */
150 struct proc *
151 pfind(pid_t pid)
152 {
153 	struct proc *p;
154 
155 	LIST_FOREACH(p, PIDHASH(pid), p_hash) {
156 		if (p->p_pid == pid)
157 			return (p);
158 	}
159 	return (NULL);
160 }
161 
162 /*
163  * Locate a process group by number
164  */
165 struct pgrp *
166 pgfind(pid_t pgid)
167 {
168 	struct pgrp *pgrp;
169 
170 	LIST_FOREACH(pgrp, PGRPHASH(pgid), pg_hash) {
171 		if (pgrp->pg_id == pgid)
172 			return (pgrp);
173 	}
174 	return (NULL);
175 }
176 
177 /*
178  * Move p to a new or existing process group (and session)
179  */
180 int
181 enterpgrp(struct proc *p, pid_t pgid, int mksess)
182 {
183 	struct pgrp *pgrp = pgfind(pgid);
184 
185 	KASSERT(pgrp == NULL || !mksess,
186 	    ("enterpgrp: setsid into non-empty pgrp"));
187 	KASSERT(!SESS_LEADER(p),
188 	    ("enterpgrp: session leader attempted setpgrp"));
189 
190 	if (pgrp == NULL) {
191 		pid_t savepid = p->p_pid;
192 		struct proc *np;
193 		/*
194 		 * new process group
195 		 */
196 		KASSERT(p->p_pid == pgid,
197 		    ("enterpgrp: new pgrp and pid != pgid"));
198 		if ((np = pfind(savepid)) == NULL || np != p)
199 			return (ESRCH);
200 		MALLOC(pgrp, struct pgrp *, sizeof(struct pgrp), M_PGRP,
201 		    M_WAITOK);
202 		if (mksess) {
203 			struct session *sess;
204 
205 			/*
206 			 * new session
207 			 */
208 			MALLOC(sess, struct session *, sizeof(struct session),
209 			    M_SESSION, M_WAITOK);
210 			sess->s_leader = p;
211 			sess->s_sid = p->p_pid;
212 			sess->s_count = 1;
213 			sess->s_ttyvp = NULL;
214 			sess->s_ttyp = NULL;
215 			bcopy(p->p_session->s_login, sess->s_login,
216 			    sizeof(sess->s_login));
217 			p->p_flag &= ~P_CONTROLT;
218 			pgrp->pg_session = sess;
219 			KASSERT(p == curproc,
220 			    ("enterpgrp: mksession and p != curproc"));
221 		} else {
222 			pgrp->pg_session = p->p_session;
223 			sess_hold(pgrp->pg_session);
224 		}
225 		pgrp->pg_id = pgid;
226 		LIST_INIT(&pgrp->pg_members);
227 		LIST_INSERT_HEAD(PGRPHASH(pgid), pgrp, pg_hash);
228 		pgrp->pg_jobc = 0;
229 		SLIST_INIT(&pgrp->pg_sigiolst);
230 		lockinit(&pgrp->pg_lock, "pgwt", 0, 0);
231 	} else if (pgrp == p->p_pgrp)
232 		return (0);
233 
234 	/*
235 	 * Adjust eligibility of affected pgrps to participate in job control.
236 	 * Increment eligibility counts before decrementing, otherwise we
237 	 * could reach 0 spuriously during the first call.
238 	 */
239 	fixjobc(p, pgrp, 1);
240 	fixjobc(p, p->p_pgrp, 0);
241 
242 	LIST_REMOVE(p, p_pglist);
243 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
244 		pgdelete(p->p_pgrp);
245 	p->p_pgrp = pgrp;
246 	LIST_INSERT_HEAD(&pgrp->pg_members, p, p_pglist);
247 	return (0);
248 }
249 
250 /*
251  * remove process from process group
252  */
253 int
254 leavepgrp(struct proc *p)
255 {
256 
257 	LIST_REMOVE(p, p_pglist);
258 	if (LIST_EMPTY(&p->p_pgrp->pg_members))
259 		pgdelete(p->p_pgrp);
260 	p->p_pgrp = 0;
261 	return (0);
262 }
263 
264 /*
265  * delete a process group
266  */
267 static void
268 pgdelete(struct pgrp *pgrp)
269 {
270 
271 	/*
272 	 * Reset any sigio structures pointing to us as a result of
273 	 * F_SETOWN with our pgid.
274 	 */
275 	funsetownlst(&pgrp->pg_sigiolst);
276 
277 	if (pgrp->pg_session->s_ttyp != NULL &&
278 	    pgrp->pg_session->s_ttyp->t_pgrp == pgrp)
279 		pgrp->pg_session->s_ttyp->t_pgrp = NULL;
280 	LIST_REMOVE(pgrp, pg_hash);
281 	sess_rele(pgrp->pg_session);
282 	kfree(pgrp, M_PGRP);
283 }
284 
285 /*
286  * Adjust the ref count on a session structure.  When the ref count falls to
287  * zero the tty is disassociated from the session and the session structure
288  * is freed.  Note that tty assocation is not itself ref-counted.
289  */
290 void
291 sess_hold(struct session *sp)
292 {
293 	++sp->s_count;
294 }
295 
296 void
297 sess_rele(struct session *sp)
298 {
299 	KKASSERT(sp->s_count > 0);
300 	if (--sp->s_count == 0) {
301 		if (sp->s_ttyp && sp->s_ttyp->t_session) {
302 #ifdef TTY_DO_FULL_CLOSE
303 			/* FULL CLOSE, see ttyclearsession() */
304 			KKASSERT(sp->s_ttyp->t_session == sp);
305 			sp->s_ttyp->t_session = NULL;
306 #else
307 			/* HALF CLOSE, see ttyclearsession() */
308 			if (sp->s_ttyp->t_session == sp)
309 				sp->s_ttyp->t_session = NULL;
310 #endif
311 		}
312 		kfree(sp, M_SESSION);
313 	}
314 }
315 
316 /*
317  * Adjust pgrp jobc counters when specified process changes process group.
318  * We count the number of processes in each process group that "qualify"
319  * the group for terminal job control (those with a parent in a different
320  * process group of the same session).  If that count reaches zero, the
321  * process group becomes orphaned.  Check both the specified process'
322  * process group and that of its children.
323  * entering == 0 => p is leaving specified group.
324  * entering == 1 => p is entering specified group.
325  */
326 void
327 fixjobc(struct proc *p, struct pgrp *pgrp, int entering)
328 {
329 	struct pgrp *hispgrp;
330 	struct session *mysession = pgrp->pg_session;
331 
332 	/*
333 	 * Check p's parent to see whether p qualifies its own process
334 	 * group; if so, adjust count for p's process group.
335 	 */
336 	if ((hispgrp = p->p_pptr->p_pgrp) != pgrp &&
337 	    hispgrp->pg_session == mysession) {
338 		if (entering)
339 			pgrp->pg_jobc++;
340 		else if (--pgrp->pg_jobc == 0)
341 			orphanpg(pgrp);
342 	}
343 
344 	/*
345 	 * Check this process' children to see whether they qualify
346 	 * their process groups; if so, adjust counts for children's
347 	 * process groups.
348 	 */
349 	LIST_FOREACH(p, &p->p_children, p_sibling)
350 		if ((hispgrp = p->p_pgrp) != pgrp &&
351 		    hispgrp->pg_session == mysession &&
352 		    p->p_stat != SZOMB) {
353 			if (entering)
354 				hispgrp->pg_jobc++;
355 			else if (--hispgrp->pg_jobc == 0)
356 				orphanpg(hispgrp);
357 		}
358 }
359 
360 /*
361  * A process group has become orphaned;
362  * if there are any stopped processes in the group,
363  * hang-up all process in that group.
364  */
365 static void
366 orphanpg(struct pgrp *pg)
367 {
368 	struct proc *p;
369 
370 	LIST_FOREACH(p, &pg->pg_members, p_pglist) {
371 		if (p->p_stat == SSTOP) {
372 			LIST_FOREACH(p, &pg->pg_members, p_pglist) {
373 				ksignal(p, SIGHUP);
374 				ksignal(p, SIGCONT);
375 			}
376 			return;
377 		}
378 	}
379 }
380 
381 /*
382  * Add a new process to the allproc list and the PID hash.  This
383  * also assigns a pid to the new process.
384  *
385  * MPALMOSTSAFE - acquires mplock for karc4random() call
386  */
387 void
388 proc_add_allproc(struct proc *p)
389 {
390 	int random_offset;
391 
392 	if ((random_offset = randompid) != 0) {
393 		get_mplock();
394 		random_offset = karc4random() % random_offset;
395 		rel_mplock();
396 	}
397 
398 	spin_lock_wr(&allproc_spin);
399 	p->p_pid = proc_getnewpid_locked(random_offset);
400 	LIST_INSERT_HEAD(&allproc, p, p_list);
401 	LIST_INSERT_HEAD(PIDHASH(p->p_pid), p, p_hash);
402 	spin_unlock_wr(&allproc_spin);
403 }
404 
405 /*
406  * Calculate a new process pid.  This function is integrated into
407  * proc_add_allproc() to guarentee that the new pid is not reused before
408  * the new process can be added to the allproc list.
409  *
410  * MPSAFE - must be called with allproc_spin held.
411  */
412 static
413 pid_t
414 proc_getnewpid_locked(int random_offset)
415 {
416 	static pid_t nextpid;
417 	static pid_t pidchecked;
418 	struct proc *p;
419 
420 	/*
421 	 * Find an unused process ID.  We remember a range of unused IDs
422 	 * ready to use (from nextpid+1 through pidchecked-1).
423 	 */
424 	nextpid = nextpid + 1 + random_offset;
425 retry:
426 	/*
427 	 * If the process ID prototype has wrapped around,
428 	 * restart somewhat above 0, as the low-numbered procs
429 	 * tend to include daemons that don't exit.
430 	 */
431 	if (nextpid >= PID_MAX) {
432 		nextpid = nextpid % PID_MAX;
433 		if (nextpid < 100)
434 			nextpid += 100;
435 		pidchecked = 0;
436 	}
437 	if (nextpid >= pidchecked) {
438 		int doingzomb = 0;
439 
440 		pidchecked = PID_MAX;
441 		/*
442 		 * Scan the active and zombie procs to check whether this pid
443 		 * is in use.  Remember the lowest pid that's greater
444 		 * than nextpid, so we can avoid checking for a while.
445 		 */
446 		p = LIST_FIRST(&allproc);
447 again:
448 		for (; p != 0; p = LIST_NEXT(p, p_list)) {
449 			while (p->p_pid == nextpid ||
450 			    p->p_pgrp->pg_id == nextpid ||
451 			    p->p_session->s_sid == nextpid) {
452 				nextpid++;
453 				if (nextpid >= pidchecked)
454 					goto retry;
455 			}
456 			if (p->p_pid > nextpid && pidchecked > p->p_pid)
457 				pidchecked = p->p_pid;
458 			if (p->p_pgrp->pg_id > nextpid &&
459 			    pidchecked > p->p_pgrp->pg_id)
460 				pidchecked = p->p_pgrp->pg_id;
461 			if (p->p_session->s_sid > nextpid &&
462 			    pidchecked > p->p_session->s_sid)
463 				pidchecked = p->p_session->s_sid;
464 		}
465 		if (!doingzomb) {
466 			doingzomb = 1;
467 			p = LIST_FIRST(&zombproc);
468 			goto again;
469 		}
470 	}
471 	return(nextpid);
472 }
473 
474 /*
475  * Called from exit1 to remove a process from the allproc
476  * list and move it to the zombie list.
477  *
478  * MPSAFE
479  */
480 void
481 proc_move_allproc_zombie(struct proc *p)
482 {
483 	spin_lock_wr(&allproc_spin);
484 	while (p->p_lock) {
485 		spin_unlock_wr(&allproc_spin);
486 		tsleep(p, 0, "reap1", hz / 10);
487 		spin_lock_wr(&allproc_spin);
488 	}
489 	LIST_REMOVE(p, p_list);
490 	LIST_INSERT_HEAD(&zombproc, p, p_list);
491 	LIST_REMOVE(p, p_hash);
492 	p->p_stat = SZOMB;
493 	spin_unlock_wr(&allproc_spin);
494 }
495 
496 /*
497  * This routine is called from kern_wait() and will remove the process
498  * from the zombie list and the sibling list.  This routine will block
499  * if someone has a lock on the proces (p_lock).
500  *
501  * MPSAFE
502  */
503 void
504 proc_remove_zombie(struct proc *p)
505 {
506 	spin_lock_wr(&allproc_spin);
507 	while (p->p_lock) {
508 		spin_unlock_wr(&allproc_spin);
509 		tsleep(p, 0, "reap1", hz / 10);
510 		spin_lock_wr(&allproc_spin);
511 	}
512 	LIST_REMOVE(p, p_list); /* off zombproc */
513 	LIST_REMOVE(p, p_sibling);
514 	spin_unlock_wr(&allproc_spin);
515 }
516 
517 /*
518  * Scan all processes on the allproc list.  The process is automatically
519  * held for the callback.  A return value of -1 terminates the loop.
520  *
521  * MPSAFE
522  */
523 void
524 allproc_scan(int (*callback)(struct proc *, void *), void *data)
525 {
526 	struct proc *p;
527 	int r;
528 
529 	spin_lock_rd(&allproc_spin);
530 	LIST_FOREACH(p, &allproc, p_list) {
531 		PHOLD(p);
532 		spin_unlock_rd(&allproc_spin);
533 		r = callback(p, data);
534 		spin_lock_rd(&allproc_spin);
535 		PRELE(p);
536 		if (r < 0)
537 			break;
538 	}
539 	spin_unlock_rd(&allproc_spin);
540 }
541 
542 /*
543  * Scan all lwps of processes on the allproc list.  The lwp is automatically
544  * held for the callback.  A return value of -1 terminates the loop.
545  *
546  * possibly not MPSAFE, needs to access foreingn proc structures
547  */
548 void
549 alllwp_scan(int (*callback)(struct lwp *, void *), void *data)
550 {
551 	struct proc *p;
552 	struct lwp *lp;
553 	int r = 0;
554 
555 	spin_lock_rd(&allproc_spin);
556 	LIST_FOREACH(p, &allproc, p_list) {
557 		PHOLD(p);
558 		spin_unlock_rd(&allproc_spin);
559 		FOREACH_LWP_IN_PROC(lp, p) {
560 			LWPHOLD(lp);
561 			r = callback(lp, data);
562 			LWPRELE(lp);
563 		}
564 		spin_lock_rd(&allproc_spin);
565 		PRELE(p);
566 		if (r < 0)
567 			break;
568 	}
569 	spin_unlock_rd(&allproc_spin);
570 }
571 
572 /*
573  * Scan all processes on the zombproc list.  The process is automatically
574  * held for the callback.  A return value of -1 terminates the loop.
575  *
576  * MPSAFE
577  */
578 void
579 zombproc_scan(int (*callback)(struct proc *, void *), void *data)
580 {
581 	struct proc *p;
582 	int r;
583 
584 	spin_lock_rd(&allproc_spin);
585 	LIST_FOREACH(p, &zombproc, p_list) {
586 		PHOLD(p);
587 		spin_unlock_rd(&allproc_spin);
588 		r = callback(p, data);
589 		spin_lock_rd(&allproc_spin);
590 		PRELE(p);
591 		if (r < 0)
592 			break;
593 	}
594 	spin_unlock_rd(&allproc_spin);
595 }
596 
597 #include "opt_ddb.h"
598 #ifdef DDB
599 #include <ddb/ddb.h>
600 
601 DB_SHOW_COMMAND(pgrpdump, pgrpdump)
602 {
603 	struct pgrp *pgrp;
604 	struct proc *p;
605 	int i;
606 
607 	for (i = 0; i <= pgrphash; i++) {
608 		if (!LIST_EMPTY(&pgrphashtbl[i])) {
609 			kprintf("\tindx %d\n", i);
610 			LIST_FOREACH(pgrp, &pgrphashtbl[i], pg_hash) {
611 				kprintf(
612 			"\tpgrp %p, pgid %ld, sess %p, sesscnt %d, mem %p\n",
613 				    (void *)pgrp, (long)pgrp->pg_id,
614 				    (void *)pgrp->pg_session,
615 				    pgrp->pg_session->s_count,
616 				    (void *)LIST_FIRST(&pgrp->pg_members));
617 				LIST_FOREACH(p, &pgrp->pg_members, p_pglist) {
618 					kprintf("\t\tpid %ld addr %p pgrp %p\n",
619 					    (long)p->p_pid, (void *)p,
620 					    (void *)p->p_pgrp);
621 				}
622 			}
623 		}
624 	}
625 }
626 #endif /* DDB */
627 
628 /*
629  * Locate a process on the zombie list.  Return a held process or NULL.
630  */
631 struct proc *
632 zpfind(pid_t pid)
633 {
634 	struct proc *p;
635 
636 	LIST_FOREACH(p, &zombproc, p_list)
637 		if (p->p_pid == pid)
638 			return (p);
639 	return (NULL);
640 }
641 
642 static int
643 sysctl_out_proc(struct proc *p, struct sysctl_req *req, int flags)
644 {
645 	struct kinfo_proc ki;
646 	struct lwp *lp;
647 	int skp = 0, had_output = 0;
648 	int error;
649 
650 	bzero(&ki, sizeof(ki));
651 	fill_kinfo_proc(p, &ki);
652 	if ((flags & KERN_PROC_FLAG_LWP) == 0)
653 		skp = 1;
654 	error = 0;
655 	FOREACH_LWP_IN_PROC(lp, p) {
656 		LWPHOLD(lp);
657 		fill_kinfo_lwp(lp, &ki.kp_lwp);
658 		had_output = 1;
659 		error = SYSCTL_OUT(req, &ki, sizeof(ki));
660 		LWPRELE(lp);
661 		if (error)
662 			break;
663 		if (skp)
664 			break;
665 	}
666 	/* We need to output at least the proc, even if there is no lwp. */
667 	if (had_output == 0) {
668 		error = SYSCTL_OUT(req, &ki, sizeof(ki));
669 	}
670 	return (error);
671 }
672 
673 static int
674 sysctl_out_proc_kthread(struct thread *td, struct sysctl_req *req, int flags)
675 {
676 	struct kinfo_proc ki;
677 	int error;
678 
679 	fill_kinfo_proc_kthread(td, &ki);
680 	error = SYSCTL_OUT(req, &ki, sizeof(ki));
681 	if (error)
682 		return error;
683 	return(0);
684 }
685 
686 static int
687 sysctl_kern_proc(SYSCTL_HANDLER_ARGS)
688 {
689 	int *name = (int*) arg1;
690 	int oid = oidp->oid_number;
691 	u_int namelen = arg2;
692 	struct proc *p;
693 	struct proclist *plist;
694 	struct thread *td;
695 	int doingzomb, flags = 0;
696 	int error = 0;
697 	int n;
698 	int origcpu;
699 	struct ucred *cr1 = curproc->p_ucred;
700 
701 	flags = oid & KERN_PROC_FLAGMASK;
702 	oid &= ~KERN_PROC_FLAGMASK;
703 
704 	if ((oid == KERN_PROC_ALL && namelen != 0) ||
705 	    (oid != KERN_PROC_ALL && namelen != 1))
706 		return (EINVAL);
707 
708 	if (oid == KERN_PROC_PID) {
709 		p = pfind((pid_t)name[0]);
710 		if (!p)
711 			return (0);
712 		if (!PRISON_CHECK(cr1, p->p_ucred))
713 			return (0);
714 		PHOLD(p);
715 		error = sysctl_out_proc(p, req, flags);
716 		PRELE(p);
717 		return (error);
718 	}
719 
720 	if (!req->oldptr) {
721 		/* overestimate by 5 procs */
722 		error = SYSCTL_OUT(req, 0, sizeof (struct kinfo_proc) * 5);
723 		if (error)
724 			return (error);
725 	}
726 	for (doingzomb = 0; doingzomb <= 1; doingzomb++) {
727 		if (doingzomb)
728 			plist = &zombproc;
729 		else
730 			plist = &allproc;
731 		LIST_FOREACH(p, plist, p_list) {
732 			/*
733 			 * Show a user only their processes.
734 			 */
735 			if ((!ps_showallprocs) && p_trespass(cr1, p->p_ucred))
736 				continue;
737 			/*
738 			 * Skip embryonic processes.
739 			 */
740 			if (p->p_stat == SIDL)
741 				continue;
742 			/*
743 			 * TODO - make more efficient (see notes below).
744 			 * do by session.
745 			 */
746 			switch (oid) {
747 			case KERN_PROC_PGRP:
748 				/* could do this by traversing pgrp */
749 				if (p->p_pgrp == NULL ||
750 				    p->p_pgrp->pg_id != (pid_t)name[0])
751 					continue;
752 				break;
753 
754 			case KERN_PROC_TTY:
755 				if ((p->p_flag & P_CONTROLT) == 0 ||
756 				    p->p_session == NULL ||
757 				    p->p_session->s_ttyp == NULL ||
758 				    dev2udev(p->p_session->s_ttyp->t_dev) !=
759 					(udev_t)name[0])
760 					continue;
761 				break;
762 
763 			case KERN_PROC_UID:
764 				if (p->p_ucred == NULL ||
765 				    p->p_ucred->cr_uid != (uid_t)name[0])
766 					continue;
767 				break;
768 
769 			case KERN_PROC_RUID:
770 				if (p->p_ucred == NULL ||
771 				    p->p_ucred->cr_ruid != (uid_t)name[0])
772 					continue;
773 				break;
774 			}
775 
776 			if (!PRISON_CHECK(cr1, p->p_ucred))
777 				continue;
778 			PHOLD(p);
779 			error = sysctl_out_proc(p, req, flags);
780 			PRELE(p);
781 			if (error)
782 				return (error);
783 		}
784 	}
785 
786 	/*
787 	 * Iterate over all active cpus and scan their thread list.  Start
788 	 * with the next logical cpu and end with our original cpu.  We
789 	 * migrate our own thread to each target cpu in order to safely scan
790 	 * its thread list.  In the last loop we migrate back to our original
791 	 * cpu.
792 	 */
793 	origcpu = mycpu->gd_cpuid;
794 	if (!ps_showallthreads || jailed(cr1))
795 		goto post_threads;
796 	for (n = 1; n <= ncpus; ++n) {
797 		globaldata_t rgd;
798 		int nid;
799 
800 		nid = (origcpu + n) % ncpus;
801 		if ((smp_active_mask & (1 << nid)) == 0)
802 			continue;
803 		rgd = globaldata_find(nid);
804 		lwkt_setcpu_self(rgd);
805 
806 		TAILQ_FOREACH(td, &mycpu->gd_tdallq, td_allq) {
807 			if (td->td_proc)
808 				continue;
809 			switch (oid) {
810 			case KERN_PROC_PGRP:
811 			case KERN_PROC_TTY:
812 			case KERN_PROC_UID:
813 			case KERN_PROC_RUID:
814 				continue;
815 			default:
816 				break;
817 			}
818 			lwkt_hold(td);
819 			error = sysctl_out_proc_kthread(td, req, doingzomb);
820 			lwkt_rele(td);
821 			if (error)
822 				return (error);
823 		}
824 	}
825 post_threads:
826 	return (0);
827 }
828 
829 /*
830  * This sysctl allows a process to retrieve the argument list or process
831  * title for another process without groping around in the address space
832  * of the other process.  It also allow a process to set its own "process
833  * title to a string of its own choice.
834  */
835 static int
836 sysctl_kern_proc_args(SYSCTL_HANDLER_ARGS)
837 {
838 	int *name = (int*) arg1;
839 	u_int namelen = arg2;
840 	struct proc *p;
841 	struct pargs *pa;
842 	int error = 0;
843 	struct ucred *cr1 = curproc->p_ucred;
844 
845 	if (namelen != 1)
846 		return (EINVAL);
847 
848 	p = pfind((pid_t)name[0]);
849 	if (!p)
850 		return (0);
851 
852 	if ((!ps_argsopen) && p_trespass(cr1, p->p_ucred))
853 		return (0);
854 
855 	if (req->newptr && curproc != p)
856 		return (EPERM);
857 
858 	if (req->oldptr && p->p_args != NULL)
859 		error = SYSCTL_OUT(req, p->p_args->ar_args, p->p_args->ar_length);
860 	if (req->newptr == NULL)
861 		return (error);
862 
863 	if (p->p_args && --p->p_args->ar_ref == 0)
864 		FREE(p->p_args, M_PARGS);
865 	p->p_args = NULL;
866 
867 	if (req->newlen + sizeof(struct pargs) > ps_arg_cache_limit)
868 		return (error);
869 
870 	MALLOC(pa, struct pargs *, sizeof(struct pargs) + req->newlen,
871 	    M_PARGS, M_WAITOK);
872 	pa->ar_ref = 1;
873 	pa->ar_length = req->newlen;
874 	error = SYSCTL_IN(req, pa->ar_args, req->newlen);
875 	if (!error)
876 		p->p_args = pa;
877 	else
878 		FREE(pa, M_PARGS);
879 	return (error);
880 }
881 
882 SYSCTL_NODE(_kern, KERN_PROC, proc, CTLFLAG_RD,  0, "Process table");
883 
884 SYSCTL_PROC(_kern_proc, KERN_PROC_ALL, all, CTLFLAG_RD|CTLTYPE_STRUCT,
885 	0, 0, sysctl_kern_proc, "S,proc", "Return entire process table");
886 
887 SYSCTL_NODE(_kern_proc, KERN_PROC_PGRP, pgrp, CTLFLAG_RD,
888 	sysctl_kern_proc, "Process table");
889 
890 SYSCTL_NODE(_kern_proc, KERN_PROC_TTY, tty, CTLFLAG_RD,
891 	sysctl_kern_proc, "Process table");
892 
893 SYSCTL_NODE(_kern_proc, KERN_PROC_UID, uid, CTLFLAG_RD,
894 	sysctl_kern_proc, "Process table");
895 
896 SYSCTL_NODE(_kern_proc, KERN_PROC_RUID, ruid, CTLFLAG_RD,
897 	sysctl_kern_proc, "Process table");
898 
899 SYSCTL_NODE(_kern_proc, KERN_PROC_PID, pid, CTLFLAG_RD,
900 	sysctl_kern_proc, "Process table");
901 
902 SYSCTL_NODE(_kern_proc, (KERN_PROC_ALL | KERN_PROC_FLAG_LWP), all_lwp, CTLFLAG_RD,
903 	sysctl_kern_proc, "Process table");
904 
905 SYSCTL_NODE(_kern_proc, (KERN_PROC_PGRP | KERN_PROC_FLAG_LWP), pgrp_lwp, CTLFLAG_RD,
906 	sysctl_kern_proc, "Process table");
907 
908 SYSCTL_NODE(_kern_proc, (KERN_PROC_TTY | KERN_PROC_FLAG_LWP), tty_lwp, CTLFLAG_RD,
909 	sysctl_kern_proc, "Process table");
910 
911 SYSCTL_NODE(_kern_proc, (KERN_PROC_UID | KERN_PROC_FLAG_LWP), uid_lwp, CTLFLAG_RD,
912 	sysctl_kern_proc, "Process table");
913 
914 SYSCTL_NODE(_kern_proc, (KERN_PROC_RUID | KERN_PROC_FLAG_LWP), ruid_lwp, CTLFLAG_RD,
915 	sysctl_kern_proc, "Process table");
916 
917 SYSCTL_NODE(_kern_proc, (KERN_PROC_PID | KERN_PROC_FLAG_LWP), pid_lwp, CTLFLAG_RD,
918 	sysctl_kern_proc, "Process table");
919 
920 SYSCTL_NODE(_kern_proc, KERN_PROC_ARGS, args, CTLFLAG_RW | CTLFLAG_ANYBODY,
921 	sysctl_kern_proc_args, "Process argument list");
922