xref: /freebsd/sys/kern/kern_procctl.c (revision 8eb2bee6c0f4957c6c1cea826e59cda4d18a2a64)
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/_unrhdr.h>
35 #include <sys/systm.h>
36 #include <sys/capsicum.h>
37 #include <sys/lock.h>
38 #include <sys/mman.h>
39 #include <sys/mutex.h>
40 #include <sys/priv.h>
41 #include <sys/proc.h>
42 #include <sys/procctl.h>
43 #include <sys/sx.h>
44 #include <sys/syscallsubr.h>
45 #include <sys/sysproto.h>
46 #include <sys/wait.h>
47 
48 #include <vm/vm.h>
49 #include <vm/pmap.h>
50 #include <vm/vm_map.h>
51 #include <vm/vm_extern.h>
52 
53 static int
54 protect_setchild(struct thread *td, struct proc *p, int flags)
55 {
56 
57 	PROC_LOCK_ASSERT(p, MA_OWNED);
58 	if (p->p_flag & P_SYSTEM || p_cansched(td, p) != 0)
59 		return (0);
60 	if (flags & PPROT_SET) {
61 		p->p_flag |= P_PROTECTED;
62 		if (flags & PPROT_INHERIT)
63 			p->p_flag2 |= P2_INHERIT_PROTECTED;
64 	} else {
65 		p->p_flag &= ~P_PROTECTED;
66 		p->p_flag2 &= ~P2_INHERIT_PROTECTED;
67 	}
68 	return (1);
69 }
70 
71 static int
72 protect_setchildren(struct thread *td, struct proc *top, int flags)
73 {
74 	struct proc *p;
75 	int ret;
76 
77 	p = top;
78 	ret = 0;
79 	sx_assert(&proctree_lock, SX_LOCKED);
80 	for (;;) {
81 		ret |= protect_setchild(td, p, flags);
82 		PROC_UNLOCK(p);
83 		/*
84 		 * If this process has children, descend to them next,
85 		 * otherwise do any siblings, and if done with this level,
86 		 * follow back up the tree (but not past top).
87 		 */
88 		if (!LIST_EMPTY(&p->p_children))
89 			p = LIST_FIRST(&p->p_children);
90 		else for (;;) {
91 			if (p == top) {
92 				PROC_LOCK(p);
93 				return (ret);
94 			}
95 			if (LIST_NEXT(p, p_sibling)) {
96 				p = LIST_NEXT(p, p_sibling);
97 				break;
98 			}
99 			p = p->p_pptr;
100 		}
101 		PROC_LOCK(p);
102 	}
103 }
104 
105 static int
106 protect_set(struct thread *td, struct proc *p, void *data)
107 {
108 	int error, flags, ret;
109 
110 	flags = *(int *)data;
111 	switch (PPROT_OP(flags)) {
112 	case PPROT_SET:
113 	case PPROT_CLEAR:
114 		break;
115 	default:
116 		return (EINVAL);
117 	}
118 
119 	if ((PPROT_FLAGS(flags) & ~(PPROT_DESCEND | PPROT_INHERIT)) != 0)
120 		return (EINVAL);
121 
122 	error = priv_check(td, PRIV_VM_MADV_PROTECT);
123 	if (error)
124 		return (error);
125 
126 	if (flags & PPROT_DESCEND)
127 		ret = protect_setchildren(td, p, flags);
128 	else
129 		ret = protect_setchild(td, p, flags);
130 	if (ret == 0)
131 		return (EPERM);
132 	return (0);
133 }
134 
135 static int
136 reap_acquire(struct thread *td, struct proc *p, void *data __unused)
137 {
138 
139 	sx_assert(&proctree_lock, SX_XLOCKED);
140 	if (p != td->td_proc)
141 		return (EPERM);
142 	if ((p->p_treeflag & P_TREE_REAPER) != 0)
143 		return (EBUSY);
144 	p->p_treeflag |= P_TREE_REAPER;
145 	/*
146 	 * We do not reattach existing children and the whole tree
147 	 * under them to us, since p->p_reaper already seen them.
148 	 */
149 	return (0);
150 }
151 
152 static int
153 reap_release(struct thread *td, struct proc *p, void *data __unused)
154 {
155 
156 	sx_assert(&proctree_lock, SX_XLOCKED);
157 	if (p != td->td_proc)
158 		return (EPERM);
159 	if (p == initproc)
160 		return (EINVAL);
161 	if ((p->p_treeflag & P_TREE_REAPER) == 0)
162 		return (EINVAL);
163 	reaper_abandon_children(p, false);
164 	return (0);
165 }
166 
167 static int
168 reap_status(struct thread *td, struct proc *p, void *data)
169 {
170 	struct proc *reap, *p2, *first_p;
171 	struct procctl_reaper_status *rs;
172 
173 	rs = data;
174 	sx_assert(&proctree_lock, SX_LOCKED);
175 	if ((p->p_treeflag & P_TREE_REAPER) == 0) {
176 		reap = p->p_reaper;
177 	} else {
178 		reap = p;
179 		rs->rs_flags |= REAPER_STATUS_OWNED;
180 	}
181 	if (reap == initproc)
182 		rs->rs_flags |= REAPER_STATUS_REALINIT;
183 	rs->rs_reaper = reap->p_pid;
184 	rs->rs_descendants = 0;
185 	rs->rs_children = 0;
186 	if (!LIST_EMPTY(&reap->p_reaplist)) {
187 		first_p = LIST_FIRST(&reap->p_children);
188 		if (first_p == NULL)
189 			first_p = LIST_FIRST(&reap->p_reaplist);
190 		rs->rs_pid = first_p->p_pid;
191 		LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) {
192 			if (proc_realparent(p2) == reap)
193 				rs->rs_children++;
194 			rs->rs_descendants++;
195 		}
196 	} else {
197 		rs->rs_pid = -1;
198 	}
199 	return (0);
200 }
201 
202 static int
203 reap_getpids(struct thread *td, struct proc *p, void *data)
204 {
205 	struct proc *reap, *p2;
206 	struct procctl_reaper_pidinfo *pi, *pip;
207 	struct procctl_reaper_pids *rp;
208 	u_int i, n;
209 	int error;
210 
211 	rp = data;
212 	sx_assert(&proctree_lock, SX_LOCKED);
213 	PROC_UNLOCK(p);
214 	reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p;
215 	n = i = 0;
216 	error = 0;
217 	LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling)
218 		n++;
219 	sx_unlock(&proctree_lock);
220 	if (rp->rp_count < n)
221 		n = rp->rp_count;
222 	pi = malloc(n * sizeof(*pi), M_TEMP, M_WAITOK);
223 	sx_slock(&proctree_lock);
224 	LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) {
225 		if (i == n)
226 			break;
227 		pip = &pi[i];
228 		bzero(pip, sizeof(*pip));
229 		pip->pi_pid = p2->p_pid;
230 		pip->pi_subtree = p2->p_reapsubtree;
231 		pip->pi_flags = REAPER_PIDINFO_VALID;
232 		if (proc_realparent(p2) == reap)
233 			pip->pi_flags |= REAPER_PIDINFO_CHILD;
234 		if ((p2->p_treeflag & P_TREE_REAPER) != 0)
235 			pip->pi_flags |= REAPER_PIDINFO_REAPER;
236 		i++;
237 	}
238 	sx_sunlock(&proctree_lock);
239 	error = copyout(pi, rp->rp_pids, i * sizeof(*pi));
240 	free(pi, M_TEMP);
241 	sx_slock(&proctree_lock);
242 	PROC_LOCK(p);
243 	return (error);
244 }
245 
246 static void
247 reap_kill_proc_relock(struct proc *p, int xlocked)
248 {
249 	PROC_UNLOCK(p);
250 	if (xlocked)
251 		sx_xlock(&proctree_lock);
252 	else
253 		sx_slock(&proctree_lock);
254 	PROC_LOCK(p);
255 }
256 
257 static void
258 reap_kill_proc_locked(struct thread *td, struct proc *p2,
259     ksiginfo_t *ksi, struct procctl_reaper_kill *rk, int *error)
260 {
261 	int error1, r, xlocked;
262 	bool need_stop;
263 
264 	PROC_LOCK_ASSERT(p2, MA_OWNED);
265 	PROC_ASSERT_HELD(p2);
266 
267 	error1 = p_cansignal(td, p2, rk->rk_sig);
268 	if (error1 != 0) {
269 		if (*error == ESRCH) {
270 			rk->rk_fpid = p2->p_pid;
271 			*error = error1;
272 		}
273 		return;
274 	}
275 
276 	/*
277 	 * The need_stop indicates if the target process needs to be
278 	 * suspended before being signalled.  This is needed when we
279 	 * guarantee that all processes in subtree are signalled,
280 	 * avoiding the race with some process not yet fully linked
281 	 * into all structures during fork, ignored by iterator, and
282 	 * then escaping signalling.
283 	 *
284 	 * If need_stop is true, then reap_kill_proc() returns true if
285 	 * the process was successfully stopped and signalled, and
286 	 * false if stopping failed and the signal was not sent.
287 	 *
288 	 * The thread cannot usefully stop itself anyway, and if other
289 	 * thread of the current process forks while the current
290 	 * thread signals the whole subtree, it is an application
291 	 * race.
292 	 */
293 	need_stop = p2 != td->td_proc &&
294 	    (td->td_proc->p_flag2 & P2_WEXIT) == 0 &&
295 	    (p2->p_flag & (P_KPROC | P_SYSTEM | P_STOPPED)) == 0 &&
296 	    (rk->rk_flags & REAPER_KILL_CHILDREN) == 0;
297 
298 	if (need_stop) {
299 		xlocked = sx_xlocked(&proctree_lock);
300 		sx_unlock(&proctree_lock);
301 		r = thread_single(p2, SINGLE_ALLPROC);
302 		reap_kill_proc_relock(p2, xlocked);
303 		if (r != 0)
304 			need_stop = false;
305 	}
306 
307 	pksignal(p2, rk->rk_sig, ksi);
308 	rk->rk_killed++;
309 	*error = error1;
310 
311 	if (need_stop)
312 		thread_single_end(p2, SINGLE_ALLPROC);
313 }
314 
315 static void
316 reap_kill_proc(struct thread *td, struct proc *p2, ksiginfo_t *ksi,
317     struct procctl_reaper_kill *rk, int *error)
318 {
319 	PROC_LOCK(p2);
320 	if ((p2->p_flag2 & P2_WEXIT) == 0) {
321 		_PHOLD_LITE(p2);
322 		reap_kill_proc_locked(td, p2, ksi, rk, error);
323 		_PRELE(p2);
324 	}
325 	PROC_UNLOCK(p2);
326 }
327 
328 struct reap_kill_tracker {
329 	struct proc *parent;
330 	TAILQ_ENTRY(reap_kill_tracker) link;
331 };
332 
333 TAILQ_HEAD(reap_kill_tracker_head, reap_kill_tracker);
334 
335 static void
336 reap_kill_sched(struct reap_kill_tracker_head *tracker, struct proc *p2)
337 {
338 	struct reap_kill_tracker *t;
339 
340 	PROC_LOCK(p2);
341 	if ((p2->p_flag2 & P2_WEXIT) != 0) {
342 		PROC_UNLOCK(p2);
343 		return;
344 	}
345 	_PHOLD_LITE(p2);
346 	PROC_UNLOCK(p2);
347 	t = malloc(sizeof(struct reap_kill_tracker), M_TEMP, M_WAITOK);
348 	t->parent = p2;
349 	TAILQ_INSERT_TAIL(tracker, t, link);
350 }
351 
352 static void
353 reap_kill_sched_free(struct reap_kill_tracker *t)
354 {
355 	PRELE(t->parent);
356 	free(t, M_TEMP);
357 }
358 
359 static void
360 reap_kill_children(struct thread *td, struct proc *reaper,
361     struct procctl_reaper_kill *rk, ksiginfo_t *ksi, int *error)
362 {
363 	struct proc *p2;
364 
365 	LIST_FOREACH(p2, &reaper->p_children, p_sibling) {
366 		(void)reap_kill_proc(td, p2, ksi, rk, error);
367 		/*
368 		 * Do not end the loop on error, signal everything we
369 		 * can.
370 		 */
371 	}
372 }
373 
374 static bool
375 reap_kill_subtree_once(struct thread *td, struct proc *p, struct proc *reaper,
376     struct procctl_reaper_kill *rk, ksiginfo_t *ksi, int *error,
377     struct unrhdr *pids)
378 {
379 	struct reap_kill_tracker_head tracker;
380 	struct reap_kill_tracker *t;
381 	struct proc *p2;
382 	bool res;
383 
384 	res = false;
385 	TAILQ_INIT(&tracker);
386 	reap_kill_sched(&tracker, reaper);
387 	while ((t = TAILQ_FIRST(&tracker)) != NULL) {
388 		TAILQ_REMOVE(&tracker, t, link);
389 
390 		/*
391 		 * Since reap_kill_proc() drops proctree_lock sx, it
392 		 * is possible that the tracked reaper is no longer.
393 		 * In this case the subtree is reparented to the new
394 		 * reaper, which should handle it.
395 		 */
396 		if ((t->parent->p_treeflag & P_TREE_REAPER) == 0) {
397 			reap_kill_sched_free(t);
398 			res = true;
399 			continue;
400 		}
401 
402 		LIST_FOREACH(p2, &t->parent->p_reaplist, p_reapsibling) {
403 			if (t->parent == reaper &&
404 			    (rk->rk_flags & REAPER_KILL_SUBTREE) != 0 &&
405 			    p2->p_reapsubtree != rk->rk_subtree)
406 				continue;
407 			if ((p2->p_treeflag & P_TREE_REAPER) != 0)
408 				reap_kill_sched(&tracker, p2);
409 			if (alloc_unr_specific(pids, p2->p_pid) != p2->p_pid)
410 				continue;
411 			reap_kill_proc(td, p2, ksi, rk, error);
412 			res = true;
413 		}
414 		reap_kill_sched_free(t);
415 	}
416 	return (res);
417 }
418 
419 static void
420 reap_kill_subtree(struct thread *td, struct proc *p, struct proc *reaper,
421     struct procctl_reaper_kill *rk, ksiginfo_t *ksi, int *error)
422 {
423 	struct unrhdr pids;
424 
425 	/*
426 	 * pids records processes which were already signalled, to
427 	 * avoid doubling signals to them if iteration needs to be
428 	 * repeated.
429 	 */
430 	init_unrhdr(&pids, 1, PID_MAX, UNR_NO_MTX);
431 	PROC_LOCK(td->td_proc);
432 	if ((td->td_proc->p_flag2 & P2_WEXIT) != 0) {
433 		PROC_UNLOCK(td->td_proc);
434 		goto out;
435 	}
436 	td->td_proc->p_singlethr++;
437 	PROC_UNLOCK(td->td_proc);
438 	while (reap_kill_subtree_once(td, p, reaper, rk, ksi, error, &pids))
439 	       ;
440 	PROC_LOCK(td->td_proc);
441 	td->td_proc->p_singlethr--;
442 	if (td->td_proc->p_singlethr == 0)
443 		wakeup(&p->p_singlethr);
444 	PROC_UNLOCK(td->td_proc);
445 out:
446 	clean_unrhdr(&pids);
447 	clear_unrhdr(&pids);
448 }
449 
450 static bool
451 reap_kill_sapblk(struct thread *td __unused, void *data)
452 {
453 	struct procctl_reaper_kill *rk;
454 
455 	rk = data;
456 	return ((rk->rk_flags & REAPER_KILL_CHILDREN) == 0);
457 }
458 
459 static int
460 reap_kill(struct thread *td, struct proc *p, void *data)
461 {
462 	struct proc *reaper;
463 	ksiginfo_t ksi;
464 	struct procctl_reaper_kill *rk;
465 	int error;
466 
467 	rk = data;
468 	sx_assert(&proctree_lock, SX_LOCKED);
469 	if (IN_CAPABILITY_MODE(td))
470 		return (ECAPMODE);
471 	if (rk->rk_sig <= 0 || rk->rk_sig > _SIG_MAXSIG ||
472 	    (rk->rk_flags & ~(REAPER_KILL_CHILDREN |
473 	    REAPER_KILL_SUBTREE)) != 0 || (rk->rk_flags &
474 	    (REAPER_KILL_CHILDREN | REAPER_KILL_SUBTREE)) ==
475 	    (REAPER_KILL_CHILDREN | REAPER_KILL_SUBTREE))
476 		return (EINVAL);
477 	PROC_UNLOCK(p);
478 	reaper = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p;
479 	ksiginfo_init(&ksi);
480 	ksi.ksi_signo = rk->rk_sig;
481 	ksi.ksi_code = SI_USER;
482 	ksi.ksi_pid = td->td_proc->p_pid;
483 	ksi.ksi_uid = td->td_ucred->cr_ruid;
484 	error = ESRCH;
485 	rk->rk_killed = 0;
486 	rk->rk_fpid = -1;
487 	if ((rk->rk_flags & REAPER_KILL_CHILDREN) != 0) {
488 		reap_kill_children(td, reaper, rk, &ksi, &error);
489 	} else {
490 		reap_kill_subtree(td, p, reaper, rk, &ksi, &error);
491 	}
492 	PROC_LOCK(p);
493 	return (error);
494 }
495 
496 static int
497 trace_ctl(struct thread *td, struct proc *p, void *data)
498 {
499 	int state;
500 
501 	PROC_LOCK_ASSERT(p, MA_OWNED);
502 	state = *(int *)data;
503 
504 	/*
505 	 * Ktrace changes p_traceflag from or to zero under the
506 	 * process lock, so the test does not need to acquire ktrace
507 	 * mutex.
508 	 */
509 	if ((p->p_flag & P_TRACED) != 0 || p->p_traceflag != 0)
510 		return (EBUSY);
511 
512 	switch (state) {
513 	case PROC_TRACE_CTL_ENABLE:
514 		if (td->td_proc != p)
515 			return (EPERM);
516 		p->p_flag2 &= ~(P2_NOTRACE | P2_NOTRACE_EXEC);
517 		break;
518 	case PROC_TRACE_CTL_DISABLE_EXEC:
519 		p->p_flag2 |= P2_NOTRACE_EXEC | P2_NOTRACE;
520 		break;
521 	case PROC_TRACE_CTL_DISABLE:
522 		if ((p->p_flag2 & P2_NOTRACE_EXEC) != 0) {
523 			KASSERT((p->p_flag2 & P2_NOTRACE) != 0,
524 			    ("dandling P2_NOTRACE_EXEC"));
525 			if (td->td_proc != p)
526 				return (EPERM);
527 			p->p_flag2 &= ~P2_NOTRACE_EXEC;
528 		} else {
529 			p->p_flag2 |= P2_NOTRACE;
530 		}
531 		break;
532 	default:
533 		return (EINVAL);
534 	}
535 	return (0);
536 }
537 
538 static int
539 trace_status(struct thread *td, struct proc *p, void *data)
540 {
541 	int *status;
542 
543 	status = data;
544 	if ((p->p_flag2 & P2_NOTRACE) != 0) {
545 		KASSERT((p->p_flag & P_TRACED) == 0,
546 		    ("%d traced but tracing disabled", p->p_pid));
547 		*status = -1;
548 	} else if ((p->p_flag & P_TRACED) != 0) {
549 		*status = p->p_pptr->p_pid;
550 	} else {
551 		*status = 0;
552 	}
553 	return (0);
554 }
555 
556 static int
557 trapcap_ctl(struct thread *td, struct proc *p, void *data)
558 {
559 	int state;
560 
561 	PROC_LOCK_ASSERT(p, MA_OWNED);
562 	state = *(int *)data;
563 
564 	switch (state) {
565 	case PROC_TRAPCAP_CTL_ENABLE:
566 		p->p_flag2 |= P2_TRAPCAP;
567 		break;
568 	case PROC_TRAPCAP_CTL_DISABLE:
569 		p->p_flag2 &= ~P2_TRAPCAP;
570 		break;
571 	default:
572 		return (EINVAL);
573 	}
574 	return (0);
575 }
576 
577 static int
578 trapcap_status(struct thread *td, struct proc *p, void *data)
579 {
580 	int *status;
581 
582 	status = data;
583 	*status = (p->p_flag2 & P2_TRAPCAP) != 0 ? PROC_TRAPCAP_CTL_ENABLE :
584 	    PROC_TRAPCAP_CTL_DISABLE;
585 	return (0);
586 }
587 
588 static int
589 no_new_privs_ctl(struct thread *td, struct proc *p, void *data)
590 {
591 	int state;
592 
593 	PROC_LOCK_ASSERT(p, MA_OWNED);
594 	state = *(int *)data;
595 
596 	if (state != PROC_NO_NEW_PRIVS_ENABLE)
597 		return (EINVAL);
598 	p->p_flag2 |= P2_NO_NEW_PRIVS;
599 	return (0);
600 }
601 
602 static int
603 no_new_privs_status(struct thread *td, struct proc *p, void *data)
604 {
605 
606 	*(int *)data = (p->p_flag2 & P2_NO_NEW_PRIVS) != 0 ?
607 	    PROC_NO_NEW_PRIVS_ENABLE : PROC_NO_NEW_PRIVS_DISABLE;
608 	return (0);
609 }
610 
611 static int
612 protmax_ctl(struct thread *td, struct proc *p, void *data)
613 {
614 	int state;
615 
616 	PROC_LOCK_ASSERT(p, MA_OWNED);
617 	state = *(int *)data;
618 
619 	switch (state) {
620 	case PROC_PROTMAX_FORCE_ENABLE:
621 		p->p_flag2 &= ~P2_PROTMAX_DISABLE;
622 		p->p_flag2 |= P2_PROTMAX_ENABLE;
623 		break;
624 	case PROC_PROTMAX_FORCE_DISABLE:
625 		p->p_flag2 |= P2_PROTMAX_DISABLE;
626 		p->p_flag2 &= ~P2_PROTMAX_ENABLE;
627 		break;
628 	case PROC_PROTMAX_NOFORCE:
629 		p->p_flag2 &= ~(P2_PROTMAX_ENABLE | P2_PROTMAX_DISABLE);
630 		break;
631 	default:
632 		return (EINVAL);
633 	}
634 	return (0);
635 }
636 
637 static int
638 protmax_status(struct thread *td, struct proc *p, void *data)
639 {
640 	int d;
641 
642 	switch (p->p_flag2 & (P2_PROTMAX_ENABLE | P2_PROTMAX_DISABLE)) {
643 	case 0:
644 		d = PROC_PROTMAX_NOFORCE;
645 		break;
646 	case P2_PROTMAX_ENABLE:
647 		d = PROC_PROTMAX_FORCE_ENABLE;
648 		break;
649 	case P2_PROTMAX_DISABLE:
650 		d = PROC_PROTMAX_FORCE_DISABLE;
651 		break;
652 	}
653 	if (kern_mmap_maxprot(p, PROT_READ) == PROT_READ)
654 		d |= PROC_PROTMAX_ACTIVE;
655 	*(int *)data = d;
656 	return (0);
657 }
658 
659 static int
660 aslr_ctl(struct thread *td, struct proc *p, void *data)
661 {
662 	int state;
663 
664 	PROC_LOCK_ASSERT(p, MA_OWNED);
665 	state = *(int *)data;
666 
667 	switch (state) {
668 	case PROC_ASLR_FORCE_ENABLE:
669 		p->p_flag2 &= ~P2_ASLR_DISABLE;
670 		p->p_flag2 |= P2_ASLR_ENABLE;
671 		break;
672 	case PROC_ASLR_FORCE_DISABLE:
673 		p->p_flag2 |= P2_ASLR_DISABLE;
674 		p->p_flag2 &= ~P2_ASLR_ENABLE;
675 		break;
676 	case PROC_ASLR_NOFORCE:
677 		p->p_flag2 &= ~(P2_ASLR_ENABLE | P2_ASLR_DISABLE);
678 		break;
679 	default:
680 		return (EINVAL);
681 	}
682 	return (0);
683 }
684 
685 static int
686 aslr_status(struct thread *td, struct proc *p, void *data)
687 {
688 	struct vmspace *vm;
689 	int d;
690 
691 	switch (p->p_flag2 & (P2_ASLR_ENABLE | P2_ASLR_DISABLE)) {
692 	case 0:
693 		d = PROC_ASLR_NOFORCE;
694 		break;
695 	case P2_ASLR_ENABLE:
696 		d = PROC_ASLR_FORCE_ENABLE;
697 		break;
698 	case P2_ASLR_DISABLE:
699 		d = PROC_ASLR_FORCE_DISABLE;
700 		break;
701 	}
702 	if ((p->p_flag & P_WEXIT) == 0) {
703 		_PHOLD(p);
704 		PROC_UNLOCK(p);
705 		vm = vmspace_acquire_ref(p);
706 		if (vm != NULL) {
707 			if ((vm->vm_map.flags & MAP_ASLR) != 0)
708 				d |= PROC_ASLR_ACTIVE;
709 			vmspace_free(vm);
710 		}
711 		PROC_LOCK(p);
712 		_PRELE(p);
713 	}
714 	*(int *)data = d;
715 	return (0);
716 }
717 
718 static int
719 stackgap_ctl(struct thread *td, struct proc *p, void *data)
720 {
721 	int state;
722 
723 	PROC_LOCK_ASSERT(p, MA_OWNED);
724 	state = *(int *)data;
725 
726 	if ((state & ~(PROC_STACKGAP_ENABLE | PROC_STACKGAP_DISABLE |
727 	    PROC_STACKGAP_ENABLE_EXEC | PROC_STACKGAP_DISABLE_EXEC)) != 0)
728 		return (EINVAL);
729 	switch (state & (PROC_STACKGAP_ENABLE | PROC_STACKGAP_DISABLE)) {
730 	case PROC_STACKGAP_ENABLE:
731 		if ((p->p_flag2 & P2_STKGAP_DISABLE) != 0)
732 			return (EINVAL);
733 		break;
734 	case PROC_STACKGAP_DISABLE:
735 		p->p_flag2 |= P2_STKGAP_DISABLE;
736 		break;
737 	case 0:
738 		break;
739 	default:
740 		return (EINVAL);
741 	}
742 	switch (state & (PROC_STACKGAP_ENABLE_EXEC |
743 	    PROC_STACKGAP_DISABLE_EXEC)) {
744 	case PROC_STACKGAP_ENABLE_EXEC:
745 		p->p_flag2 &= ~P2_STKGAP_DISABLE_EXEC;
746 		break;
747 	case PROC_STACKGAP_DISABLE_EXEC:
748 		p->p_flag2 |= P2_STKGAP_DISABLE_EXEC;
749 		break;
750 	case 0:
751 		break;
752 	default:
753 		return (EINVAL);
754 	}
755 	return (0);
756 }
757 
758 static int
759 stackgap_status(struct thread *td, struct proc *p, void *data)
760 {
761 	int d;
762 
763 	PROC_LOCK_ASSERT(p, MA_OWNED);
764 
765 	d = (p->p_flag2 & P2_STKGAP_DISABLE) != 0 ? PROC_STACKGAP_DISABLE :
766 	    PROC_STACKGAP_ENABLE;
767 	d |= (p->p_flag2 & P2_STKGAP_DISABLE_EXEC) != 0 ?
768 	    PROC_STACKGAP_DISABLE_EXEC : PROC_STACKGAP_ENABLE_EXEC;
769 	*(int *)data = d;
770 	return (0);
771 }
772 
773 static int
774 wxmap_ctl(struct thread *td, struct proc *p, void *data)
775 {
776 	struct vmspace *vm;
777 	vm_map_t map;
778 	int state;
779 
780 	PROC_LOCK_ASSERT(p, MA_OWNED);
781 	if ((p->p_flag & P_WEXIT) != 0)
782 		return (ESRCH);
783 	state = *(int *)data;
784 
785 	switch (state) {
786 	case PROC_WX_MAPPINGS_PERMIT:
787 		p->p_flag2 |= P2_WXORX_DISABLE;
788 		_PHOLD(p);
789 		PROC_UNLOCK(p);
790 		vm = vmspace_acquire_ref(p);
791 		if (vm != NULL) {
792 			map = &vm->vm_map;
793 			vm_map_lock(map);
794 			map->flags &= ~MAP_WXORX;
795 			vm_map_unlock(map);
796 			vmspace_free(vm);
797 		}
798 		PROC_LOCK(p);
799 		_PRELE(p);
800 		break;
801 	case PROC_WX_MAPPINGS_DISALLOW_EXEC:
802 		p->p_flag2 |= P2_WXORX_ENABLE_EXEC;
803 		break;
804 	default:
805 		return (EINVAL);
806 	}
807 
808 	return (0);
809 }
810 
811 static int
812 wxmap_status(struct thread *td, struct proc *p, void *data)
813 {
814 	struct vmspace *vm;
815 	int d;
816 
817 	PROC_LOCK_ASSERT(p, MA_OWNED);
818 	if ((p->p_flag & P_WEXIT) != 0)
819 		return (ESRCH);
820 
821 	d = 0;
822 	if ((p->p_flag2 & P2_WXORX_DISABLE) != 0)
823 		d |= PROC_WX_MAPPINGS_PERMIT;
824 	if ((p->p_flag2 & P2_WXORX_ENABLE_EXEC) != 0)
825 		d |= PROC_WX_MAPPINGS_DISALLOW_EXEC;
826 	_PHOLD(p);
827 	PROC_UNLOCK(p);
828 	vm = vmspace_acquire_ref(p);
829 	if (vm != NULL) {
830 		if ((vm->vm_map.flags & MAP_WXORX) != 0)
831 			d |= PROC_WXORX_ENFORCE;
832 		vmspace_free(vm);
833 	}
834 	PROC_LOCK(p);
835 	_PRELE(p);
836 	*(int *)data = d;
837 	return (0);
838 }
839 
840 static int
841 pdeathsig_ctl(struct thread *td, struct proc *p, void *data)
842 {
843 	int signum;
844 
845 	signum = *(int *)data;
846 	if (p != td->td_proc || (signum != 0 && !_SIG_VALID(signum)))
847 		return (EINVAL);
848 	p->p_pdeathsig = signum;
849 	return (0);
850 }
851 
852 static int
853 pdeathsig_status(struct thread *td, struct proc *p, void *data)
854 {
855 	if (p != td->td_proc)
856 		return (EINVAL);
857 	*(int *)data = p->p_pdeathsig;
858 	return (0);
859 }
860 
861 enum {
862 	PCTL_SLOCKED,
863 	PCTL_XLOCKED,
864 	PCTL_UNLOCKED,
865 };
866 
867 struct procctl_cmd_info {
868 	int lock_tree;
869 	bool one_proc : 1;
870 	bool esrch_is_einval : 1;
871 	bool copyout_on_error : 1;
872 	bool no_nonnull_data : 1;
873 	bool need_candebug : 1;
874 	int copyin_sz;
875 	int copyout_sz;
876 	int (*exec)(struct thread *, struct proc *, void *);
877 	bool (*sapblk)(struct thread *, void *);
878 };
879 static const struct procctl_cmd_info procctl_cmds_info[] = {
880 	[PROC_SPROTECT] =
881 	    { .lock_tree = PCTL_SLOCKED, .one_proc = false,
882 	      .esrch_is_einval = false, .no_nonnull_data = false,
883 	      .need_candebug = false,
884 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
885 	      .exec = protect_set, .copyout_on_error = false, },
886 	[PROC_REAP_ACQUIRE] =
887 	    { .lock_tree = PCTL_XLOCKED, .one_proc = true,
888 	      .esrch_is_einval = false, .no_nonnull_data = true,
889 	      .need_candebug = false,
890 	      .copyin_sz = 0, .copyout_sz = 0,
891 	      .exec = reap_acquire, .copyout_on_error = false, },
892 	[PROC_REAP_RELEASE] =
893 	    { .lock_tree = PCTL_XLOCKED, .one_proc = true,
894 	      .esrch_is_einval = false, .no_nonnull_data = true,
895 	      .need_candebug = false,
896 	      .copyin_sz = 0, .copyout_sz = 0,
897 	      .exec = reap_release, .copyout_on_error = false, },
898 	[PROC_REAP_STATUS] =
899 	    { .lock_tree = PCTL_SLOCKED, .one_proc = true,
900 	      .esrch_is_einval = false, .no_nonnull_data = false,
901 	      .need_candebug = false,
902 	      .copyin_sz = 0,
903 	      .copyout_sz = sizeof(struct procctl_reaper_status),
904 	      .exec = reap_status, .copyout_on_error = false, },
905 	[PROC_REAP_GETPIDS] =
906 	    { .lock_tree = PCTL_SLOCKED, .one_proc = true,
907 	      .esrch_is_einval = false, .no_nonnull_data = false,
908 	      .need_candebug = false,
909 	      .copyin_sz = sizeof(struct procctl_reaper_pids),
910 	      .copyout_sz = 0,
911 	      .exec = reap_getpids, .copyout_on_error = false, },
912 	[PROC_REAP_KILL] =
913 	    { .lock_tree = PCTL_SLOCKED, .one_proc = true,
914 	      .esrch_is_einval = false, .no_nonnull_data = false,
915 	      .need_candebug = false,
916 	      .copyin_sz = sizeof(struct procctl_reaper_kill),
917 	      .copyout_sz = sizeof(struct procctl_reaper_kill),
918 	      .exec = reap_kill, .copyout_on_error = true,
919 	      .sapblk = reap_kill_sapblk, },
920 	[PROC_TRACE_CTL] =
921 	    { .lock_tree = PCTL_SLOCKED, .one_proc = false,
922 	      .esrch_is_einval = false, .no_nonnull_data = false,
923 	      .need_candebug = true,
924 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
925 	      .exec = trace_ctl, .copyout_on_error = false, },
926 	[PROC_TRACE_STATUS] =
927 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
928 	      .esrch_is_einval = false, .no_nonnull_data = false,
929 	      .need_candebug = false,
930 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
931 	      .exec = trace_status, .copyout_on_error = false, },
932 	[PROC_TRAPCAP_CTL] =
933 	    { .lock_tree = PCTL_SLOCKED, .one_proc = false,
934 	      .esrch_is_einval = false, .no_nonnull_data = false,
935 	      .need_candebug = true,
936 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
937 	      .exec = trapcap_ctl, .copyout_on_error = false, },
938 	[PROC_TRAPCAP_STATUS] =
939 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
940 	      .esrch_is_einval = false, .no_nonnull_data = false,
941 	      .need_candebug = false,
942 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
943 	      .exec = trapcap_status, .copyout_on_error = false, },
944 	[PROC_PDEATHSIG_CTL] =
945 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
946 	      .esrch_is_einval = true, .no_nonnull_data = false,
947 	      .need_candebug = false,
948 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
949 	      .exec = pdeathsig_ctl, .copyout_on_error = false, },
950 	[PROC_PDEATHSIG_STATUS] =
951 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
952 	      .esrch_is_einval = true, .no_nonnull_data = false,
953 	      .need_candebug = false,
954 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
955 	      .exec = pdeathsig_status, .copyout_on_error = false, },
956 	[PROC_ASLR_CTL] =
957 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
958 	      .esrch_is_einval = false, .no_nonnull_data = false,
959 	      .need_candebug = true,
960 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
961 	      .exec = aslr_ctl, .copyout_on_error = false, },
962 	[PROC_ASLR_STATUS] =
963 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
964 	      .esrch_is_einval = false, .no_nonnull_data = false,
965 	      .need_candebug = false,
966 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
967 	      .exec = aslr_status, .copyout_on_error = false, },
968 	[PROC_PROTMAX_CTL] =
969 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
970 	      .esrch_is_einval = false, .no_nonnull_data = false,
971 	      .need_candebug = true,
972 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
973 	      .exec = protmax_ctl, .copyout_on_error = false, },
974 	[PROC_PROTMAX_STATUS] =
975 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
976 	      .esrch_is_einval = false, .no_nonnull_data = false,
977 	      .need_candebug = false,
978 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
979 	      .exec = protmax_status, .copyout_on_error = false, },
980 	[PROC_STACKGAP_CTL] =
981 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
982 	      .esrch_is_einval = false, .no_nonnull_data = false,
983 	      .need_candebug = true,
984 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
985 	      .exec = stackgap_ctl, .copyout_on_error = false, },
986 	[PROC_STACKGAP_STATUS] =
987 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
988 	      .esrch_is_einval = false, .no_nonnull_data = false,
989 	      .need_candebug = false,
990 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
991 	      .exec = stackgap_status, .copyout_on_error = false, },
992 	[PROC_NO_NEW_PRIVS_CTL] =
993 	    { .lock_tree = PCTL_SLOCKED, .one_proc = true,
994 	      .esrch_is_einval = false, .no_nonnull_data = false,
995 	      .need_candebug = true,
996 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
997 	      .exec = no_new_privs_ctl, .copyout_on_error = false, },
998 	[PROC_NO_NEW_PRIVS_STATUS] =
999 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
1000 	      .esrch_is_einval = false, .no_nonnull_data = false,
1001 	      .need_candebug = false,
1002 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
1003 	      .exec = no_new_privs_status, .copyout_on_error = false, },
1004 	[PROC_WXMAP_CTL] =
1005 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
1006 	      .esrch_is_einval = false, .no_nonnull_data = false,
1007 	      .need_candebug = true,
1008 	      .copyin_sz = sizeof(int), .copyout_sz = 0,
1009 	      .exec = wxmap_ctl, .copyout_on_error = false, },
1010 	[PROC_WXMAP_STATUS] =
1011 	    { .lock_tree = PCTL_UNLOCKED, .one_proc = true,
1012 	      .esrch_is_einval = false, .no_nonnull_data = false,
1013 	      .need_candebug = false,
1014 	      .copyin_sz = 0, .copyout_sz = sizeof(int),
1015 	      .exec = wxmap_status, .copyout_on_error = false, },
1016 };
1017 
1018 int
1019 sys_procctl(struct thread *td, struct procctl_args *uap)
1020 {
1021 	union {
1022 		struct procctl_reaper_status rs;
1023 		struct procctl_reaper_pids rp;
1024 		struct procctl_reaper_kill rk;
1025 		int flags;
1026 	} x;
1027 	const struct procctl_cmd_info *cmd_info;
1028 	int error, error1;
1029 
1030 	if (uap->com >= PROC_PROCCTL_MD_MIN)
1031 		return (cpu_procctl(td, uap->idtype, uap->id,
1032 		    uap->com, uap->data));
1033 	if (uap->com == 0 || uap->com >= nitems(procctl_cmds_info))
1034 		return (EINVAL);
1035 	cmd_info = &procctl_cmds_info[uap->com];
1036 	bzero(&x, sizeof(x));
1037 
1038 	if (cmd_info->copyin_sz > 0) {
1039 		error = copyin(uap->data, &x, cmd_info->copyin_sz);
1040 		if (error != 0)
1041 			return (error);
1042 	} else if (cmd_info->no_nonnull_data && uap->data != NULL) {
1043 		return (EINVAL);
1044 	}
1045 
1046 	error = kern_procctl(td, uap->idtype, uap->id, uap->com, &x);
1047 
1048 	if (cmd_info->copyout_sz > 0 && (error == 0 ||
1049 	    cmd_info->copyout_on_error)) {
1050 		error1 = copyout(&x, uap->data, cmd_info->copyout_sz);
1051 		if (error == 0)
1052 			error = error1;
1053 	}
1054 	return (error);
1055 }
1056 
1057 static int
1058 kern_procctl_single(struct thread *td, struct proc *p, int com, void *data)
1059 {
1060 
1061 	PROC_LOCK_ASSERT(p, MA_OWNED);
1062 	return (procctl_cmds_info[com].exec(td, p, data));
1063 }
1064 
1065 int
1066 kern_procctl(struct thread *td, idtype_t idtype, id_t id, int com, void *data)
1067 {
1068 	struct pgrp *pg;
1069 	struct proc *p;
1070 	const struct procctl_cmd_info *cmd_info;
1071 	int error, first_error, ok;
1072 	bool sapblk;
1073 
1074 	MPASS(com > 0 && com < nitems(procctl_cmds_info));
1075 	cmd_info = &procctl_cmds_info[com];
1076 	if (idtype != P_PID && cmd_info->one_proc)
1077 		return (EINVAL);
1078 
1079 	sapblk = false;
1080 	if (cmd_info->sapblk != NULL) {
1081 		sapblk = cmd_info->sapblk(td, data);
1082 		if (sapblk && !stop_all_proc_block())
1083 			return (ERESTART);
1084 	}
1085 
1086 	switch (cmd_info->lock_tree) {
1087 	case PCTL_XLOCKED:
1088 		sx_xlock(&proctree_lock);
1089 		break;
1090 	case PCTL_SLOCKED:
1091 		sx_slock(&proctree_lock);
1092 		break;
1093 	default:
1094 		break;
1095 	}
1096 
1097 	switch (idtype) {
1098 	case P_PID:
1099 		if (id == 0) {
1100 			p = td->td_proc;
1101 			error = 0;
1102 			PROC_LOCK(p);
1103 		} else {
1104 			p = pfind(id);
1105 			if (p == NULL) {
1106 				error = cmd_info->esrch_is_einval ?
1107 				    EINVAL : ESRCH;
1108 				break;
1109 			}
1110 			error = cmd_info->need_candebug ? p_candebug(td, p) :
1111 			    p_cansee(td, p);
1112 		}
1113 		if (error == 0)
1114 			error = kern_procctl_single(td, p, com, data);
1115 		PROC_UNLOCK(p);
1116 		break;
1117 	case P_PGID:
1118 		/*
1119 		 * Attempt to apply the operation to all members of the
1120 		 * group.  Ignore processes in the group that can't be
1121 		 * seen.  Ignore errors so long as at least one process is
1122 		 * able to complete the request successfully.
1123 		 */
1124 		pg = pgfind(id);
1125 		if (pg == NULL) {
1126 			error = ESRCH;
1127 			break;
1128 		}
1129 		PGRP_UNLOCK(pg);
1130 		ok = 0;
1131 		first_error = 0;
1132 		LIST_FOREACH(p, &pg->pg_members, p_pglist) {
1133 			PROC_LOCK(p);
1134 			if (p->p_state == PRS_NEW ||
1135 			    p->p_state == PRS_ZOMBIE ||
1136 			    (cmd_info->need_candebug ? p_candebug(td, p) :
1137 			    p_cansee(td, p)) != 0) {
1138 				PROC_UNLOCK(p);
1139 				continue;
1140 			}
1141 			error = kern_procctl_single(td, p, com, data);
1142 			PROC_UNLOCK(p);
1143 			if (error == 0)
1144 				ok = 1;
1145 			else if (first_error == 0)
1146 				first_error = error;
1147 		}
1148 		if (ok)
1149 			error = 0;
1150 		else if (first_error != 0)
1151 			error = first_error;
1152 		else
1153 			/*
1154 			 * Was not able to see any processes in the
1155 			 * process group.
1156 			 */
1157 			error = ESRCH;
1158 		break;
1159 	default:
1160 		error = EINVAL;
1161 		break;
1162 	}
1163 
1164 	switch (cmd_info->lock_tree) {
1165 	case PCTL_XLOCKED:
1166 		sx_xunlock(&proctree_lock);
1167 		break;
1168 	case PCTL_SLOCKED:
1169 		sx_sunlock(&proctree_lock);
1170 		break;
1171 	default:
1172 		break;
1173 	}
1174 	if (sapblk)
1175 		stop_all_proc_unblock();
1176 	return (error);
1177 }
1178