xref: /freebsd/sys/kern/kern_procctl.c (revision 86aa9539fef591a363b06a0ebd3aa7a07f4c1579)
1 /*-
2  * Copyright (c) 2014 John Baldwin
3  * Copyright (c) 2014, 2016 The FreeBSD Foundation
4  *
5  * Portions of this software were developed by Konstantin Belousov
6  * under sponsorship from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/capsicum.h>
36 #include <sys/lock.h>
37 #include <sys/mman.h>
38 #include <sys/mutex.h>
39 #include <sys/priv.h>
40 #include <sys/proc.h>
41 #include <sys/procctl.h>
42 #include <sys/sx.h>
43 #include <sys/syscallsubr.h>
44 #include <sys/sysproto.h>
45 #include <sys/wait.h>
46 
47 #include <vm/vm.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_map.h>
50 #include <vm/vm_extern.h>
51 
52 static int
53 protect_setchild(struct thread *td, struct proc *p, int flags)
54 {
55 
56 	PROC_LOCK_ASSERT(p, MA_OWNED);
57 	if (p->p_flag & P_SYSTEM || p_cansched(td, p) != 0)
58 		return (0);
59 	if (flags & PPROT_SET) {
60 		p->p_flag |= P_PROTECTED;
61 		if (flags & PPROT_INHERIT)
62 			p->p_flag2 |= P2_INHERIT_PROTECTED;
63 	} else {
64 		p->p_flag &= ~P_PROTECTED;
65 		p->p_flag2 &= ~P2_INHERIT_PROTECTED;
66 	}
67 	return (1);
68 }
69 
70 static int
71 protect_setchildren(struct thread *td, struct proc *top, int flags)
72 {
73 	struct proc *p;
74 	int ret;
75 
76 	p = top;
77 	ret = 0;
78 	sx_assert(&proctree_lock, SX_LOCKED);
79 	for (;;) {
80 		ret |= protect_setchild(td, p, flags);
81 		PROC_UNLOCK(p);
82 		/*
83 		 * If this process has children, descend to them next,
84 		 * otherwise do any siblings, and if done with this level,
85 		 * follow back up the tree (but not past top).
86 		 */
87 		if (!LIST_EMPTY(&p->p_children))
88 			p = LIST_FIRST(&p->p_children);
89 		else for (;;) {
90 			if (p == top) {
91 				PROC_LOCK(p);
92 				return (ret);
93 			}
94 			if (LIST_NEXT(p, p_sibling)) {
95 				p = LIST_NEXT(p, p_sibling);
96 				break;
97 			}
98 			p = p->p_pptr;
99 		}
100 		PROC_LOCK(p);
101 	}
102 }
103 
104 static int
105 protect_set(struct thread *td, struct proc *p, int flags)
106 {
107 	int error, ret;
108 
109 	switch (PPROT_OP(flags)) {
110 	case PPROT_SET:
111 	case PPROT_CLEAR:
112 		break;
113 	default:
114 		return (EINVAL);
115 	}
116 
117 	if ((PPROT_FLAGS(flags) & ~(PPROT_DESCEND | PPROT_INHERIT)) != 0)
118 		return (EINVAL);
119 
120 	error = priv_check(td, PRIV_VM_MADV_PROTECT);
121 	if (error)
122 		return (error);
123 
124 	if (flags & PPROT_DESCEND)
125 		ret = protect_setchildren(td, p, flags);
126 	else
127 		ret = protect_setchild(td, p, flags);
128 	if (ret == 0)
129 		return (EPERM);
130 	return (0);
131 }
132 
133 static int
134 reap_acquire(struct thread *td, struct proc *p)
135 {
136 
137 	sx_assert(&proctree_lock, SX_XLOCKED);
138 	if (p != curproc)
139 		return (EPERM);
140 	if ((p->p_treeflag & P_TREE_REAPER) != 0)
141 		return (EBUSY);
142 	p->p_treeflag |= P_TREE_REAPER;
143 	/*
144 	 * We do not reattach existing children and the whole tree
145 	 * under them to us, since p->p_reaper already seen them.
146 	 */
147 	return (0);
148 }
149 
150 static int
151 reap_release(struct thread *td, struct proc *p)
152 {
153 
154 	sx_assert(&proctree_lock, SX_XLOCKED);
155 	if (p != curproc)
156 		return (EPERM);
157 	if (p == initproc)
158 		return (EINVAL);
159 	if ((p->p_treeflag & P_TREE_REAPER) == 0)
160 		return (EINVAL);
161 	reaper_abandon_children(p, false);
162 	return (0);
163 }
164 
165 static int
166 reap_status(struct thread *td, struct proc *p,
167     struct procctl_reaper_status *rs)
168 {
169 	struct proc *reap, *p2, *first_p;
170 
171 	sx_assert(&proctree_lock, SX_LOCKED);
172 	bzero(rs, sizeof(*rs));
173 	if ((p->p_treeflag & P_TREE_REAPER) == 0) {
174 		reap = p->p_reaper;
175 	} else {
176 		reap = p;
177 		rs->rs_flags |= REAPER_STATUS_OWNED;
178 	}
179 	if (reap == initproc)
180 		rs->rs_flags |= REAPER_STATUS_REALINIT;
181 	rs->rs_reaper = reap->p_pid;
182 	rs->rs_descendants = 0;
183 	rs->rs_children = 0;
184 	if (!LIST_EMPTY(&reap->p_reaplist)) {
185 		first_p = LIST_FIRST(&reap->p_children);
186 		if (first_p == NULL)
187 			first_p = LIST_FIRST(&reap->p_reaplist);
188 		rs->rs_pid = first_p->p_pid;
189 		LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) {
190 			if (proc_realparent(p2) == reap)
191 				rs->rs_children++;
192 			rs->rs_descendants++;
193 		}
194 	} else {
195 		rs->rs_pid = -1;
196 	}
197 	return (0);
198 }
199 
200 static int
201 reap_getpids(struct thread *td, struct proc *p, struct procctl_reaper_pids *rp)
202 {
203 	struct proc *reap, *p2;
204 	struct procctl_reaper_pidinfo *pi, *pip;
205 	u_int i, n;
206 	int error;
207 
208 	sx_assert(&proctree_lock, SX_LOCKED);
209 	PROC_UNLOCK(p);
210 	reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p;
211 	n = i = 0;
212 	error = 0;
213 	LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling)
214 		n++;
215 	sx_unlock(&proctree_lock);
216 	if (rp->rp_count < n)
217 		n = rp->rp_count;
218 	pi = malloc(n * sizeof(*pi), M_TEMP, M_WAITOK);
219 	sx_slock(&proctree_lock);
220 	LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) {
221 		if (i == n)
222 			break;
223 		pip = &pi[i];
224 		bzero(pip, sizeof(*pip));
225 		pip->pi_pid = p2->p_pid;
226 		pip->pi_subtree = p2->p_reapsubtree;
227 		pip->pi_flags = REAPER_PIDINFO_VALID;
228 		if (proc_realparent(p2) == reap)
229 			pip->pi_flags |= REAPER_PIDINFO_CHILD;
230 		if ((p2->p_treeflag & P_TREE_REAPER) != 0)
231 			pip->pi_flags |= REAPER_PIDINFO_REAPER;
232 		i++;
233 	}
234 	sx_sunlock(&proctree_lock);
235 	error = copyout(pi, rp->rp_pids, i * sizeof(*pi));
236 	free(pi, M_TEMP);
237 	sx_slock(&proctree_lock);
238 	PROC_LOCK(p);
239 	return (error);
240 }
241 
242 static void
243 reap_kill_proc(struct thread *td, struct proc *p2, ksiginfo_t *ksi,
244     struct procctl_reaper_kill *rk, int *error)
245 {
246 	int error1;
247 
248 	PROC_LOCK(p2);
249 	error1 = p_cansignal(td, p2, rk->rk_sig);
250 	if (error1 == 0) {
251 		pksignal(p2, rk->rk_sig, ksi);
252 		rk->rk_killed++;
253 		*error = error1;
254 	} else if (*error == ESRCH) {
255 		rk->rk_fpid = p2->p_pid;
256 		*error = error1;
257 	}
258 	PROC_UNLOCK(p2);
259 }
260 
261 struct reap_kill_tracker {
262 	struct proc *parent;
263 	TAILQ_ENTRY(reap_kill_tracker) link;
264 };
265 
266 TAILQ_HEAD(reap_kill_tracker_head, reap_kill_tracker);
267 
268 static void
269 reap_kill_sched(struct reap_kill_tracker_head *tracker, struct proc *p2)
270 {
271 	struct reap_kill_tracker *t;
272 
273 	t = malloc(sizeof(struct reap_kill_tracker), M_TEMP, M_WAITOK);
274 	t->parent = p2;
275 	TAILQ_INSERT_TAIL(tracker, t, link);
276 }
277 
278 static int
279 reap_kill(struct thread *td, struct proc *p, struct procctl_reaper_kill *rk)
280 {
281 	struct proc *reap, *p2;
282 	ksiginfo_t ksi;
283 	struct reap_kill_tracker_head tracker;
284 	struct reap_kill_tracker *t;
285 	int error;
286 
287 	sx_assert(&proctree_lock, SX_LOCKED);
288 	if (IN_CAPABILITY_MODE(td))
289 		return (ECAPMODE);
290 	if (rk->rk_sig <= 0 || rk->rk_sig > _SIG_MAXSIG ||
291 	    (rk->rk_flags & ~(REAPER_KILL_CHILDREN |
292 	    REAPER_KILL_SUBTREE)) != 0 || (rk->rk_flags &
293 	    (REAPER_KILL_CHILDREN | REAPER_KILL_SUBTREE)) ==
294 	    (REAPER_KILL_CHILDREN | REAPER_KILL_SUBTREE))
295 		return (EINVAL);
296 	PROC_UNLOCK(p);
297 	reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p;
298 	ksiginfo_init(&ksi);
299 	ksi.ksi_signo = rk->rk_sig;
300 	ksi.ksi_code = SI_USER;
301 	ksi.ksi_pid = td->td_proc->p_pid;
302 	ksi.ksi_uid = td->td_ucred->cr_ruid;
303 	error = ESRCH;
304 	rk->rk_killed = 0;
305 	rk->rk_fpid = -1;
306 	if ((rk->rk_flags & REAPER_KILL_CHILDREN) != 0) {
307 		for (p2 = LIST_FIRST(&reap->p_children); p2 != NULL;
308 		    p2 = LIST_NEXT(p2, p_sibling)) {
309 			reap_kill_proc(td, p2, &ksi, rk, &error);
310 			/*
311 			 * Do not end the loop on error, signal
312 			 * everything we can.
313 			 */
314 		}
315 	} else {
316 		TAILQ_INIT(&tracker);
317 		reap_kill_sched(&tracker, reap);
318 		while ((t = TAILQ_FIRST(&tracker)) != NULL) {
319 			MPASS((t->parent->p_treeflag & P_TREE_REAPER) != 0);
320 			TAILQ_REMOVE(&tracker, t, link);
321 			for (p2 = LIST_FIRST(&t->parent->p_reaplist); p2 != NULL;
322 			    p2 = LIST_NEXT(p2, p_reapsibling)) {
323 				if (t->parent == reap &&
324 				    (rk->rk_flags & REAPER_KILL_SUBTREE) != 0 &&
325 				    p2->p_reapsubtree != rk->rk_subtree)
326 					continue;
327 				if ((p2->p_treeflag & P_TREE_REAPER) != 0)
328 					reap_kill_sched(&tracker, p2);
329 				reap_kill_proc(td, p2, &ksi, rk, &error);
330 			}
331 			free(t, M_TEMP);
332 		}
333 	}
334 	PROC_LOCK(p);
335 	return (error);
336 }
337 
338 static int
339 trace_ctl(struct thread *td, struct proc *p, int state)
340 {
341 
342 	PROC_LOCK_ASSERT(p, MA_OWNED);
343 
344 	/*
345 	 * Ktrace changes p_traceflag from or to zero under the
346 	 * process lock, so the test does not need to acquire ktrace
347 	 * mutex.
348 	 */
349 	if ((p->p_flag & P_TRACED) != 0 || p->p_traceflag != 0)
350 		return (EBUSY);
351 
352 	switch (state) {
353 	case PROC_TRACE_CTL_ENABLE:
354 		if (td->td_proc != p)
355 			return (EPERM);
356 		p->p_flag2 &= ~(P2_NOTRACE | P2_NOTRACE_EXEC);
357 		break;
358 	case PROC_TRACE_CTL_DISABLE_EXEC:
359 		p->p_flag2 |= P2_NOTRACE_EXEC | P2_NOTRACE;
360 		break;
361 	case PROC_TRACE_CTL_DISABLE:
362 		if ((p->p_flag2 & P2_NOTRACE_EXEC) != 0) {
363 			KASSERT((p->p_flag2 & P2_NOTRACE) != 0,
364 			    ("dandling P2_NOTRACE_EXEC"));
365 			if (td->td_proc != p)
366 				return (EPERM);
367 			p->p_flag2 &= ~P2_NOTRACE_EXEC;
368 		} else {
369 			p->p_flag2 |= P2_NOTRACE;
370 		}
371 		break;
372 	default:
373 		return (EINVAL);
374 	}
375 	return (0);
376 }
377 
378 static int
379 trace_status(struct thread *td, struct proc *p, int *data)
380 {
381 
382 	if ((p->p_flag2 & P2_NOTRACE) != 0) {
383 		KASSERT((p->p_flag & P_TRACED) == 0,
384 		    ("%d traced but tracing disabled", p->p_pid));
385 		*data = -1;
386 	} else if ((p->p_flag & P_TRACED) != 0) {
387 		*data = p->p_pptr->p_pid;
388 	} else {
389 		*data = 0;
390 	}
391 	return (0);
392 }
393 
394 static int
395 trapcap_ctl(struct thread *td, struct proc *p, int state)
396 {
397 
398 	PROC_LOCK_ASSERT(p, MA_OWNED);
399 
400 	switch (state) {
401 	case PROC_TRAPCAP_CTL_ENABLE:
402 		p->p_flag2 |= P2_TRAPCAP;
403 		break;
404 	case PROC_TRAPCAP_CTL_DISABLE:
405 		p->p_flag2 &= ~P2_TRAPCAP;
406 		break;
407 	default:
408 		return (EINVAL);
409 	}
410 	return (0);
411 }
412 
413 static int
414 trapcap_status(struct thread *td, struct proc *p, int *data)
415 {
416 
417 	*data = (p->p_flag2 & P2_TRAPCAP) != 0 ? PROC_TRAPCAP_CTL_ENABLE :
418 	    PROC_TRAPCAP_CTL_DISABLE;
419 	return (0);
420 }
421 
422 static int
423 protmax_ctl(struct thread *td, struct proc *p, int state)
424 {
425 	PROC_LOCK_ASSERT(p, MA_OWNED);
426 
427 	switch (state) {
428 	case PROC_PROTMAX_FORCE_ENABLE:
429 		p->p_flag2 &= ~P2_PROTMAX_DISABLE;
430 		p->p_flag2 |= P2_PROTMAX_ENABLE;
431 		break;
432 	case PROC_PROTMAX_FORCE_DISABLE:
433 		p->p_flag2 |= P2_PROTMAX_DISABLE;
434 		p->p_flag2 &= ~P2_PROTMAX_ENABLE;
435 		break;
436 	case PROC_PROTMAX_NOFORCE:
437 		p->p_flag2 &= ~(P2_PROTMAX_ENABLE | P2_PROTMAX_DISABLE);
438 		break;
439 	default:
440 		return (EINVAL);
441 	}
442 	return (0);
443 }
444 
445 static int
446 protmax_status(struct thread *td, struct proc *p, int *data)
447 {
448 	int d;
449 
450 	switch (p->p_flag2 & (P2_PROTMAX_ENABLE | P2_PROTMAX_DISABLE)) {
451 	case 0:
452 		d = PROC_ASLR_NOFORCE;
453 		break;
454 	case P2_PROTMAX_ENABLE:
455 		d = PROC_PROTMAX_FORCE_ENABLE;
456 		break;
457 	case P2_PROTMAX_DISABLE:
458 		d = PROC_PROTMAX_FORCE_DISABLE;
459 		break;
460 	}
461 	if (kern_mmap_maxprot(p, PROT_READ) == PROT_READ)
462 		d |= PROC_PROTMAX_ACTIVE;
463 	*data = d;
464 	return (0);
465 }
466 
467 static int
468 aslr_ctl(struct thread *td, struct proc *p, int state)
469 {
470 
471 	PROC_LOCK_ASSERT(p, MA_OWNED);
472 
473 	switch (state) {
474 	case PROC_ASLR_FORCE_ENABLE:
475 		p->p_flag2 &= ~P2_ASLR_DISABLE;
476 		p->p_flag2 |= P2_ASLR_ENABLE;
477 		break;
478 	case PROC_ASLR_FORCE_DISABLE:
479 		p->p_flag2 |= P2_ASLR_DISABLE;
480 		p->p_flag2 &= ~P2_ASLR_ENABLE;
481 		break;
482 	case PROC_ASLR_NOFORCE:
483 		p->p_flag2 &= ~(P2_ASLR_ENABLE | P2_ASLR_DISABLE);
484 		break;
485 	default:
486 		return (EINVAL);
487 	}
488 	return (0);
489 }
490 
491 static int
492 aslr_status(struct thread *td, struct proc *p, int *data)
493 {
494 	struct vmspace *vm;
495 	int d;
496 
497 	switch (p->p_flag2 & (P2_ASLR_ENABLE | P2_ASLR_DISABLE)) {
498 	case 0:
499 		d = PROC_ASLR_NOFORCE;
500 		break;
501 	case P2_ASLR_ENABLE:
502 		d = PROC_ASLR_FORCE_ENABLE;
503 		break;
504 	case P2_ASLR_DISABLE:
505 		d = PROC_ASLR_FORCE_DISABLE;
506 		break;
507 	}
508 	if ((p->p_flag & P_WEXIT) == 0) {
509 		_PHOLD(p);
510 		PROC_UNLOCK(p);
511 		vm = vmspace_acquire_ref(p);
512 		if (vm != NULL && (vm->vm_map.flags & MAP_ASLR) != 0) {
513 			d |= PROC_ASLR_ACTIVE;
514 			vmspace_free(vm);
515 		}
516 		PROC_LOCK(p);
517 		_PRELE(p);
518 	}
519 	*data = d;
520 	return (0);
521 }
522 
523 #ifndef _SYS_SYSPROTO_H_
524 struct procctl_args {
525 	idtype_t idtype;
526 	id_t	id;
527 	int	com;
528 	void	*data;
529 };
530 #endif
531 /* ARGSUSED */
532 int
533 sys_procctl(struct thread *td, struct procctl_args *uap)
534 {
535 	void *data;
536 	union {
537 		struct procctl_reaper_status rs;
538 		struct procctl_reaper_pids rp;
539 		struct procctl_reaper_kill rk;
540 	} x;
541 	int error, error1, flags, signum;
542 
543 	if (uap->com >= PROC_PROCCTL_MD_MIN)
544 		return (cpu_procctl(td, uap->idtype, uap->id,
545 		    uap->com, uap->data));
546 
547 	switch (uap->com) {
548 	case PROC_ASLR_CTL:
549 	case PROC_PROTMAX_CTL:
550 	case PROC_SPROTECT:
551 	case PROC_TRACE_CTL:
552 	case PROC_TRAPCAP_CTL:
553 		error = copyin(uap->data, &flags, sizeof(flags));
554 		if (error != 0)
555 			return (error);
556 		data = &flags;
557 		break;
558 	case PROC_REAP_ACQUIRE:
559 	case PROC_REAP_RELEASE:
560 		if (uap->data != NULL)
561 			return (EINVAL);
562 		data = NULL;
563 		break;
564 	case PROC_REAP_STATUS:
565 		data = &x.rs;
566 		break;
567 	case PROC_REAP_GETPIDS:
568 		error = copyin(uap->data, &x.rp, sizeof(x.rp));
569 		if (error != 0)
570 			return (error);
571 		data = &x.rp;
572 		break;
573 	case PROC_REAP_KILL:
574 		error = copyin(uap->data, &x.rk, sizeof(x.rk));
575 		if (error != 0)
576 			return (error);
577 		data = &x.rk;
578 		break;
579 	case PROC_ASLR_STATUS:
580 	case PROC_PROTMAX_STATUS:
581 	case PROC_TRACE_STATUS:
582 	case PROC_TRAPCAP_STATUS:
583 		data = &flags;
584 		break;
585 	case PROC_PDEATHSIG_CTL:
586 		error = copyin(uap->data, &signum, sizeof(signum));
587 		if (error != 0)
588 			return (error);
589 		data = &signum;
590 		break;
591 	case PROC_PDEATHSIG_STATUS:
592 		data = &signum;
593 		break;
594 	default:
595 		return (EINVAL);
596 	}
597 	error = kern_procctl(td, uap->idtype, uap->id, uap->com, data);
598 	switch (uap->com) {
599 	case PROC_REAP_STATUS:
600 		if (error == 0)
601 			error = copyout(&x.rs, uap->data, sizeof(x.rs));
602 		break;
603 	case PROC_REAP_KILL:
604 		error1 = copyout(&x.rk, uap->data, sizeof(x.rk));
605 		if (error == 0)
606 			error = error1;
607 		break;
608 	case PROC_ASLR_STATUS:
609 	case PROC_PROTMAX_STATUS:
610 	case PROC_TRACE_STATUS:
611 	case PROC_TRAPCAP_STATUS:
612 		if (error == 0)
613 			error = copyout(&flags, uap->data, sizeof(flags));
614 		break;
615 	case PROC_PDEATHSIG_STATUS:
616 		if (error == 0)
617 			error = copyout(&signum, uap->data, sizeof(signum));
618 		break;
619 	}
620 	return (error);
621 }
622 
623 static int
624 kern_procctl_single(struct thread *td, struct proc *p, int com, void *data)
625 {
626 
627 	PROC_LOCK_ASSERT(p, MA_OWNED);
628 	switch (com) {
629 	case PROC_ASLR_CTL:
630 		return (aslr_ctl(td, p, *(int *)data));
631 	case PROC_ASLR_STATUS:
632 		return (aslr_status(td, p, data));
633 	case PROC_SPROTECT:
634 		return (protect_set(td, p, *(int *)data));
635 	case PROC_PROTMAX_CTL:
636 		return (protmax_ctl(td, p, *(int *)data));
637 	case PROC_PROTMAX_STATUS:
638 		return (protmax_status(td, p, data));
639 	case PROC_REAP_ACQUIRE:
640 		return (reap_acquire(td, p));
641 	case PROC_REAP_RELEASE:
642 		return (reap_release(td, p));
643 	case PROC_REAP_STATUS:
644 		return (reap_status(td, p, data));
645 	case PROC_REAP_GETPIDS:
646 		return (reap_getpids(td, p, data));
647 	case PROC_REAP_KILL:
648 		return (reap_kill(td, p, data));
649 	case PROC_TRACE_CTL:
650 		return (trace_ctl(td, p, *(int *)data));
651 	case PROC_TRACE_STATUS:
652 		return (trace_status(td, p, data));
653 	case PROC_TRAPCAP_CTL:
654 		return (trapcap_ctl(td, p, *(int *)data));
655 	case PROC_TRAPCAP_STATUS:
656 		return (trapcap_status(td, p, data));
657 	default:
658 		return (EINVAL);
659 	}
660 }
661 
662 int
663 kern_procctl(struct thread *td, idtype_t idtype, id_t id, int com, void *data)
664 {
665 	struct pgrp *pg;
666 	struct proc *p;
667 	int error, first_error, ok;
668 	int signum;
669 	bool tree_locked;
670 
671 	switch (com) {
672 	case PROC_ASLR_CTL:
673 	case PROC_ASLR_STATUS:
674 	case PROC_PROTMAX_CTL:
675 	case PROC_PROTMAX_STATUS:
676 	case PROC_REAP_ACQUIRE:
677 	case PROC_REAP_RELEASE:
678 	case PROC_REAP_STATUS:
679 	case PROC_REAP_GETPIDS:
680 	case PROC_REAP_KILL:
681 	case PROC_TRACE_STATUS:
682 	case PROC_TRAPCAP_STATUS:
683 	case PROC_PDEATHSIG_CTL:
684 	case PROC_PDEATHSIG_STATUS:
685 		if (idtype != P_PID)
686 			return (EINVAL);
687 	}
688 
689 	switch (com) {
690 	case PROC_PDEATHSIG_CTL:
691 		signum = *(int *)data;
692 		p = td->td_proc;
693 		if ((id != 0 && id != p->p_pid) ||
694 		    (signum != 0 && !_SIG_VALID(signum)))
695 			return (EINVAL);
696 		PROC_LOCK(p);
697 		p->p_pdeathsig = signum;
698 		PROC_UNLOCK(p);
699 		return (0);
700 	case PROC_PDEATHSIG_STATUS:
701 		p = td->td_proc;
702 		if (id != 0 && id != p->p_pid)
703 			return (EINVAL);
704 		PROC_LOCK(p);
705 		*(int *)data = p->p_pdeathsig;
706 		PROC_UNLOCK(p);
707 		return (0);
708 	}
709 
710 	switch (com) {
711 	case PROC_SPROTECT:
712 	case PROC_REAP_STATUS:
713 	case PROC_REAP_GETPIDS:
714 	case PROC_REAP_KILL:
715 	case PROC_TRACE_CTL:
716 	case PROC_TRAPCAP_CTL:
717 		sx_slock(&proctree_lock);
718 		tree_locked = true;
719 		break;
720 	case PROC_REAP_ACQUIRE:
721 	case PROC_REAP_RELEASE:
722 		sx_xlock(&proctree_lock);
723 		tree_locked = true;
724 		break;
725 	case PROC_ASLR_CTL:
726 	case PROC_ASLR_STATUS:
727 	case PROC_PROTMAX_CTL:
728 	case PROC_PROTMAX_STATUS:
729 	case PROC_TRACE_STATUS:
730 	case PROC_TRAPCAP_STATUS:
731 		tree_locked = false;
732 		break;
733 	default:
734 		return (EINVAL);
735 	}
736 
737 	switch (idtype) {
738 	case P_PID:
739 		p = pfind(id);
740 		if (p == NULL) {
741 			error = ESRCH;
742 			break;
743 		}
744 		error = p_cansee(td, p);
745 		if (error == 0)
746 			error = kern_procctl_single(td, p, com, data);
747 		PROC_UNLOCK(p);
748 		break;
749 	case P_PGID:
750 		/*
751 		 * Attempt to apply the operation to all members of the
752 		 * group.  Ignore processes in the group that can't be
753 		 * seen.  Ignore errors so long as at least one process is
754 		 * able to complete the request successfully.
755 		 */
756 		pg = pgfind(id);
757 		if (pg == NULL) {
758 			error = ESRCH;
759 			break;
760 		}
761 		PGRP_UNLOCK(pg);
762 		ok = 0;
763 		first_error = 0;
764 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
765 			PROC_LOCK(p);
766 			if (p->p_state == PRS_NEW || p_cansee(td, p) != 0) {
767 				PROC_UNLOCK(p);
768 				continue;
769 			}
770 			error = kern_procctl_single(td, p, com, data);
771 			PROC_UNLOCK(p);
772 			if (error == 0)
773 				ok = 1;
774 			else if (first_error == 0)
775 				first_error = error;
776 		}
777 		if (ok)
778 			error = 0;
779 		else if (first_error != 0)
780 			error = first_error;
781 		else
782 			/*
783 			 * Was not able to see any processes in the
784 			 * process group.
785 			 */
786 			error = ESRCH;
787 		break;
788 	default:
789 		error = EINVAL;
790 		break;
791 	}
792 	if (tree_locked)
793 		sx_unlock(&proctree_lock);
794 	return (error);
795 }
796