xref: /netbsd-src/sys/kern/sys_ptrace_common.c (revision c9496f6b604074a9451a67df576a5b423068e71e)
1 /*	$NetBSD: sys_ptrace_common.c,v 1.34 2018/01/08 06:10:30 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c) 1982, 1986, 1989, 1993
34  *	The Regents of the University of California.  All rights reserved.
35  * (c) UNIX System Laboratories, Inc.
36  * All or some portions of this file are derived from material licensed
37  * to the University of California by American Telephone and Telegraph
38  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
39  * the permission of UNIX System Laboratories, Inc.
40  *
41  * This code is derived from software contributed to Berkeley by
42  * Jan-Simon Pendry.
43  *
44  * Redistribution and use in source and binary forms, with or without
45  * modification, are permitted provided that the following conditions
46  * are met:
47  * 1. Redistributions of source code must retain the above copyright
48  *    notice, this list of conditions and the following disclaimer.
49  * 2. Redistributions in binary form must reproduce the above copyright
50  *    notice, this list of conditions and the following disclaimer in the
51  *    documentation and/or other materials provided with the distribution.
52  * 3. Neither the name of the University nor the names of its contributors
53  *    may be used to endorse or promote products derived from this software
54  *    without specific prior written permission.
55  *
56  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
57  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
58  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
59  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
60  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
61  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
62  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
63  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
64  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
65  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
66  * SUCH DAMAGE.
67  *
68  *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
69  */
70 
71 /*-
72  * Copyright (c) 1993 Jan-Simon Pendry.
73  * Copyright (c) 1994 Christopher G. Demetriou.  All rights reserved.
74  *
75  * This code is derived from software contributed to Berkeley by
76  * Jan-Simon Pendry.
77  *
78  * Redistribution and use in source and binary forms, with or without
79  * modification, are permitted provided that the following conditions
80  * are met:
81  * 1. Redistributions of source code must retain the above copyright
82  *    notice, this list of conditions and the following disclaimer.
83  * 2. Redistributions in binary form must reproduce the above copyright
84  *    notice, this list of conditions and the following disclaimer in the
85  *    documentation and/or other materials provided with the distribution.
86  * 3. All advertising materials mentioning features or use of this software
87  *    must display the following acknowledgement:
88  *	This product includes software developed by the University of
89  *	California, Berkeley and its contributors.
90  * 4. Neither the name of the University nor the names of its contributors
91  *    may be used to endorse or promote products derived from this software
92  *    without specific prior written permission.
93  *
94  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
95  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
96  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
97  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
98  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
99  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
100  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
101  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
102  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
103  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
104  * SUCH DAMAGE.
105  *
106  *	from: @(#)sys_process.c	8.1 (Berkeley) 6/10/93
107  */
108 
109 /*
110  * References:
111  *	(1) Bach's "The Design of the UNIX Operating System",
112  *	(2) sys/miscfs/procfs from UCB's 4.4BSD-Lite distribution,
113  *	(3) the "4.4BSD Programmer's Reference Manual" published
114  *		by USENIX and O'Reilly & Associates.
115  * The 4.4BSD PRM does a reasonably good job of documenting what the various
116  * ptrace() requests should actually do, and its text is quoted several times
117  * in this file.
118  */
119 
120 #include <sys/cdefs.h>
121 __KERNEL_RCSID(0, "$NetBSD: sys_ptrace_common.c,v 1.34 2018/01/08 06:10:30 christos Exp $");
122 
123 #ifdef _KERNEL_OPT
124 #include "opt_ptrace.h"
125 #include "opt_ktrace.h"
126 #include "opt_pax.h"
127 #include "opt_compat_netbsd32.h"
128 #endif
129 
130 #if defined(__HAVE_COMPAT_NETBSD32) && !defined(COMPAT_NETBSD32) \
131     && !defined(_RUMPKERNEL)
132 #define COMPAT_NETBSD32
133 #endif
134 
135 #include <sys/param.h>
136 #include <sys/systm.h>
137 #include <sys/proc.h>
138 #include <sys/errno.h>
139 #include <sys/exec.h>
140 #include <sys/pax.h>
141 #include <sys/ptrace.h>
142 #include <sys/uio.h>
143 #include <sys/ras.h>
144 #include <sys/kmem.h>
145 #include <sys/kauth.h>
146 #include <sys/mount.h>
147 #include <sys/syscallargs.h>
148 #include <sys/module.h>
149 #include <sys/condvar.h>
150 #include <sys/mutex.h>
151 
152 #include <uvm/uvm_extern.h>
153 
154 #include <machine/reg.h>
155 
156 #ifdef PTRACE
157 
158 # ifdef DEBUG
159 #  define DPRINTF(a) uprintf a
160 # else
161 #  define DPRINTF(a)
162 # endif
163 
164 static kauth_listener_t ptrace_listener;
165 static int process_auxv_offset(struct proc *, struct uio *);
166 
167 #if 0
168 static int ptrace_cbref;
169 static kmutex_t ptrace_mtx;
170 static kcondvar_t ptrace_cv;
171 #endif
172 
173 #ifdef PT_GETREGS
174 # define case_PT_GETREGS	case PT_GETREGS:
175 #else
176 # define case_PT_GETREGS
177 #endif
178 
179 #ifdef PT_SETREGS
180 # define case_PT_SETREGS	case PT_SETREGS:
181 #else
182 # define case_PT_SETREGS
183 #endif
184 
185 #ifdef PT_GETFPREGS
186 # define case_PT_GETFPREGS	case PT_GETFPREGS:
187 #else
188 # define case_PT_GETFPREGS
189 #endif
190 
191 #ifdef PT_SETFPREGS
192 # define case_PT_SETFPREGS	case PT_SETFPREGS:
193 #else
194 # define case_PT_SETFPREGS
195 #endif
196 
197 #ifdef PT_GETDBREGS
198 # define case_PT_GETDBREGS	case PT_GETDBREGS:
199 #else
200 # define case_PT_GETDBREGS
201 #endif
202 
203 #ifdef PT_SETDBREGS
204 # define case_PT_SETDBREGS	case PT_SETDBREGS:
205 #else
206 # define case_PT_SETDBREGS
207 #endif
208 
209 #if defined(PT_SETREGS) || defined(PT_GETREGS) || \
210     defined(PT_SETFPREGS) || defined(PT_GETFOREGS) || \
211     defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
212 # define PT_REGISTERS
213 #endif
214 
215 static int
216 ptrace_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
217     void *arg0, void *arg1, void *arg2, void *arg3)
218 {
219 	struct proc *p;
220 	int result;
221 
222 	result = KAUTH_RESULT_DEFER;
223 	p = arg0;
224 
225 #if 0
226 	mutex_enter(&ptrace_mtx);
227 	ptrace_cbref++;
228 	mutex_exit(&ptrace_mtx);
229 #endif
230 	if (action != KAUTH_PROCESS_PTRACE)
231 		goto out;
232 
233 	switch ((u_long)arg1) {
234 	case PT_TRACE_ME:
235 	case PT_ATTACH:
236 	case PT_WRITE_I:
237 	case PT_WRITE_D:
238 	case PT_READ_I:
239 	case PT_READ_D:
240 	case PT_IO:
241 	case_PT_GETREGS
242 	case_PT_SETREGS
243 	case_PT_GETFPREGS
244 	case_PT_SETFPREGS
245 	case_PT_GETDBREGS
246 	case_PT_SETDBREGS
247 	case PT_SET_EVENT_MASK:
248 	case PT_GET_EVENT_MASK:
249 	case PT_GET_PROCESS_STATE:
250 	case PT_SET_SIGINFO:
251 	case PT_GET_SIGINFO:
252 	case PT_SET_SIGMASK:
253 	case PT_GET_SIGMASK:
254 #ifdef __HAVE_PTRACE_MACHDEP
255 	PTRACE_MACHDEP_REQUEST_CASES
256 #endif
257 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
258 		    ISSET(p->p_flag, PK_SUGID)) {
259 			break;
260 		}
261 
262 		result = KAUTH_RESULT_ALLOW;
263 
264 	break;
265 
266 #ifdef PT_STEP
267 	case PT_STEP:
268 	case PT_SETSTEP:
269 	case PT_CLEARSTEP:
270 #endif
271 	case PT_CONTINUE:
272 	case PT_KILL:
273 	case PT_DETACH:
274 	case PT_LWPINFO:
275 	case PT_SYSCALL:
276 	case PT_SYSCALLEMU:
277 	case PT_DUMPCORE:
278 	case PT_RESUME:
279 	case PT_SUSPEND:
280 		result = KAUTH_RESULT_ALLOW;
281 		break;
282 
283 	default:
284 		break;
285 	}
286 
287  out:
288 #if 0
289 	mutex_enter(&ptrace_mtx);
290 	if (--ptrace_cbref == 0)
291 		cv_broadcast(&ptrace_cv);
292 	mutex_exit(&ptrace_mtx);
293 #endif
294 
295 	return result;
296 }
297 
298 int
299 ptrace_init(void)
300 {
301 
302 #if 0
303 	mutex_init(&ptrace_mtx, MUTEX_DEFAULT, IPL_NONE);
304 	cv_init(&ptrace_cv, "ptracecb");
305 	ptrace_cbref = 0;
306 #endif
307 	ptrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
308 	    ptrace_listener_cb, NULL);
309 	return 0;
310 }
311 
312 int
313 ptrace_fini(void)
314 {
315 
316 	kauth_unlisten_scope(ptrace_listener);
317 
318 #if 0
319 	/* Make sure no-one is executing our kauth listener */
320 
321 	mutex_enter(&ptrace_mtx);
322 	while (ptrace_cbref != 0)
323 		cv_wait(&ptrace_cv, &ptrace_mtx);
324 	mutex_exit(&ptrace_mtx);
325 	mutex_destroy(&ptrace_mtx);
326 	cv_destroy(&ptrace_cv);
327 #endif
328 
329 	return 0;
330 }
331 
332 static struct proc *
333 ptrace_find(struct lwp *l, int req, pid_t pid)
334 {
335 	struct proc *t;
336 
337 	/* "A foolish consistency..." XXX */
338 	if (req == PT_TRACE_ME) {
339 		t = l->l_proc;
340 		mutex_enter(t->p_lock);
341 		return t;
342 	}
343 
344 	/* Find the process we're supposed to be operating on. */
345 	t = proc_find(pid);
346 	if (t == NULL)
347 		return NULL;
348 
349 	/* XXX-elad */
350 	mutex_enter(t->p_lock);
351 	int error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
352 	    t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
353 	if (error) {
354 		mutex_exit(t->p_lock);
355 		return NULL;
356 	}
357 	return t;
358 }
359 
360 static int
361 ptrace_allowed(struct lwp *l, int req, struct proc *t, struct proc *p)
362 {
363 	/*
364 	 * Grab a reference on the process to prevent it from execing or
365 	 * exiting.
366 	 */
367 	if (!rw_tryenter(&t->p_reflock, RW_READER))
368 		return EBUSY;
369 
370 	/* Make sure we can operate on it. */
371 	switch (req) {
372 	case PT_TRACE_ME:
373 		/* Saying that you're being traced is always legal. */
374 		return 0;
375 
376 	case PT_ATTACH:
377 		/*
378 		 * You can't attach to a process if:
379 		 *	(1) it's the process that's doing the attaching,
380 		 */
381 		if (t->p_pid == p->p_pid)
382 			return EINVAL;
383 
384 		/*
385 		 *  (2) it's a system process
386 		 */
387 		if (t->p_flag & PK_SYSTEM)
388 			return EPERM;
389 
390 		/*
391 		 *	(3) it's already being traced, or
392 		 */
393 		if (ISSET(t->p_slflag, PSL_TRACED))
394 			return EBUSY;
395 
396 		/*
397 		 * 	(4) the tracer is chrooted, and its root directory is
398 		 * 	    not at or above the root directory of the tracee
399 		 */
400 		mutex_exit(t->p_lock);	/* XXXSMP */
401 		int tmp = proc_isunder(t, l);
402 		mutex_enter(t->p_lock);	/* XXXSMP */
403 		if (!tmp)
404 			return EPERM;
405 		return 0;
406 
407 	case PT_READ_I:
408 	case PT_READ_D:
409 	case PT_WRITE_I:
410 	case PT_WRITE_D:
411 	case PT_IO:
412 	case PT_SET_SIGINFO:
413 	case PT_GET_SIGINFO:
414 	case PT_SET_SIGMASK:
415 	case PT_GET_SIGMASK:
416 	case_PT_GETREGS
417 	case_PT_SETREGS
418 	case_PT_GETFPREGS
419 	case_PT_SETFPREGS
420 	case_PT_GETDBREGS
421 	case_PT_SETDBREGS
422 #ifdef __HAVE_PTRACE_MACHDEP
423 	PTRACE_MACHDEP_REQUEST_CASES
424 #endif
425 		/*
426 		 * You can't read/write the memory or registers of a process
427 		 * if the tracer is chrooted, and its root directory is not at
428 		 * or above the root directory of the tracee.
429 		 */
430 		mutex_exit(t->p_lock);	/* XXXSMP */
431 		tmp = proc_isunder(t, l);
432 		mutex_enter(t->p_lock);	/* XXXSMP */
433 		if (!tmp)
434 			return EPERM;
435 		/*FALLTHROUGH*/
436 
437 	case PT_CONTINUE:
438 	case PT_KILL:
439 	case PT_DETACH:
440 	case PT_LWPINFO:
441 	case PT_SYSCALL:
442 	case PT_SYSCALLEMU:
443 	case PT_DUMPCORE:
444 #ifdef PT_STEP
445 	case PT_STEP:
446 	case PT_SETSTEP:
447 	case PT_CLEARSTEP:
448 #endif
449 	case PT_SET_EVENT_MASK:
450 	case PT_GET_EVENT_MASK:
451 	case PT_GET_PROCESS_STATE:
452 	case PT_RESUME:
453 	case PT_SUSPEND:
454 		/*
455 		 * You can't do what you want to the process if:
456 		 *	(1) It's not being traced at all,
457 		 */
458 		if (!ISSET(t->p_slflag, PSL_TRACED))
459 			return EPERM;
460 
461 		/*
462 		 *	(2) it's not being traced by _you_, or
463 		 */
464 		if (t->p_pptr != p) {
465 			DPRINTF(("parent %d != %d\n", t->p_pptr->p_pid,
466 			    p->p_pid));
467 			return EBUSY;
468 		}
469 
470 		/*
471 		 *	(3) it's not currently stopped.
472 		 */
473 		if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) {
474 			DPRINTF(("stat %d flag %d\n", t->p_stat,
475 			    !t->p_waited));
476 			return EBUSY;
477 		}
478 		return 0;
479 
480 	default:			/* It was not a legal request. */
481 		return EINVAL;
482 	}
483 }
484 
485 static int
486 ptrace_needs_hold(int req)
487 {
488 	switch (req) {
489 #ifdef PT_STEP
490 	case PT_STEP:
491 #endif
492 	case PT_CONTINUE:
493 	case PT_DETACH:
494 	case PT_KILL:
495 	case PT_SYSCALL:
496 	case PT_SYSCALLEMU:
497 	case PT_ATTACH:
498 	case PT_TRACE_ME:
499 	case PT_GET_SIGINFO:
500 	case PT_SET_SIGINFO:
501 		return 1;
502 	default:
503 		return 0;
504 	}
505 }
506 
507 static int
508 ptrace_update_lwp(struct proc *t, struct lwp **lt, lwpid_t lid)
509 {
510 	if (lid == 0 || lid == (*lt)->l_lid || t->p_nlwps == 1)
511 		return 0;
512 
513 	lwp_delref(*lt);
514 
515 	mutex_enter(t->p_lock);
516 	*lt = lwp_find(t, lid);
517 	if (*lt == NULL) {
518 		mutex_exit(t->p_lock);
519 		return ESRCH;
520 	}
521 
522 	if ((*lt)->l_flag & LW_SYSTEM) {
523 		*lt = NULL;
524 		return EINVAL;
525 	}
526 
527 	lwp_addref(*lt);
528 	mutex_exit(t->p_lock);
529 
530 	return 0;
531 }
532 
533 static int
534 ptrace_get_siginfo(struct proc *t, struct ptrace_methods *ptm, void *addr,
535     size_t data)
536 {
537 	struct ptrace_siginfo psi;
538 
539 	psi.psi_siginfo._info = t->p_sigctx.ps_info;
540 	psi.psi_lwpid = t->p_sigctx.ps_lwp;
541 
542 	return ptm->ptm_copyout_siginfo(&psi, addr, data);
543 }
544 
545 static int
546 ptrace_set_siginfo(struct proc *t, struct lwp **lt, struct ptrace_methods *ptm,
547     void *addr, size_t data)
548 {
549 	struct ptrace_siginfo psi;
550 
551 	int error = ptm->ptm_copyin_siginfo(&psi, addr, data);
552 	if (error)
553 		return error;
554 
555 	/* Check that the data is a valid signal number or zero. */
556 	if (psi.psi_siginfo.si_signo < 0 || psi.psi_siginfo.si_signo >= NSIG)
557 		return EINVAL;
558 
559 	if ((error = ptrace_update_lwp(t, lt, psi.psi_lwpid)) != 0)
560 		return error;
561 
562 	t->p_sigctx.ps_faked = true;
563 	t->p_sigctx.ps_info = psi.psi_siginfo._info;
564 	t->p_sigctx.ps_lwp = psi.psi_lwpid;
565 	return 0;
566 }
567 
568 static int
569 ptrace_get_event_mask(struct proc *t, void *addr, size_t data)
570 {
571 	struct ptrace_event pe;
572 
573 	if (data != sizeof(pe)) {
574 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
575 		return EINVAL;
576 	}
577 	memset(&pe, 0, sizeof(pe));
578 	pe.pe_set_event = ISSET(t->p_slflag, PSL_TRACEFORK) ?
579 	    PTRACE_FORK : 0;
580 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK) ?
581 	    PTRACE_VFORK : 0;
582 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK_DONE) ?
583 	    PTRACE_VFORK_DONE : 0;
584 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_CREATE) ?
585 	    PTRACE_LWP_CREATE : 0;
586 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_EXIT) ?
587 	    PTRACE_LWP_EXIT : 0;
588 	return copyout(&pe, addr, sizeof(pe));
589 }
590 
591 static int
592 ptrace_set_event_mask(struct proc *t, void *addr, size_t data)
593 {
594 	struct ptrace_event pe;
595 	int error;
596 
597 	if (data != sizeof(pe)) {
598 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
599 		return EINVAL;
600 	}
601 	if ((error = copyin(addr, &pe, sizeof(pe))) != 0)
602 		return error;
603 
604 	if (pe.pe_set_event & PTRACE_FORK)
605 		SET(t->p_slflag, PSL_TRACEFORK);
606 	else
607 		CLR(t->p_slflag, PSL_TRACEFORK);
608 #if notyet
609 	if (pe.pe_set_event & PTRACE_VFORK)
610 		SET(t->p_slflag, PSL_TRACEVFORK);
611 	else
612 		CLR(t->p_slflag, PSL_TRACEVFORK);
613 #else
614 	if (pe.pe_set_event & PTRACE_VFORK)
615 		return ENOTSUP;
616 #endif
617 	if (pe.pe_set_event & PTRACE_VFORK_DONE)
618 		SET(t->p_slflag, PSL_TRACEVFORK_DONE);
619 	else
620 		CLR(t->p_slflag, PSL_TRACEVFORK_DONE);
621 	if (pe.pe_set_event & PTRACE_LWP_CREATE)
622 		SET(t->p_slflag, PSL_TRACELWP_CREATE);
623 	else
624 		CLR(t->p_slflag, PSL_TRACELWP_CREATE);
625 	if (pe.pe_set_event & PTRACE_LWP_EXIT)
626 		SET(t->p_slflag, PSL_TRACELWP_EXIT);
627 	else
628 		CLR(t->p_slflag, PSL_TRACELWP_EXIT);
629 	return 0;
630 }
631 
632 static int
633 ptrace_get_process_state(struct proc *t, void *addr, size_t data)
634 {
635 	struct ptrace_state ps;
636 
637 	if (data != sizeof(ps)) {
638 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(ps)));
639 		return EINVAL;
640 	}
641 	memset(&ps, 0, sizeof(ps));
642 
643 	if (t->p_fpid) {
644 		ps.pe_report_event = PTRACE_FORK;
645 		ps.pe_other_pid = t->p_fpid;
646 	} else if (t->p_vfpid) {
647 		ps.pe_report_event = PTRACE_VFORK;
648 		ps.pe_other_pid = t->p_vfpid;
649 	} else if (t->p_vfpid_done) {
650 		ps.pe_report_event = PTRACE_VFORK_DONE;
651 		ps.pe_other_pid = t->p_vfpid_done;
652 	} else if (t->p_lwp_created) {
653 		ps.pe_report_event = PTRACE_LWP_CREATE;
654 		ps.pe_lwp = t->p_lwp_created;
655 	} else if (t->p_lwp_exited) {
656 		ps.pe_report_event = PTRACE_LWP_EXIT;
657 		ps.pe_lwp = t->p_lwp_exited;
658 	}
659 	return copyout(&ps, addr, sizeof(ps));
660 }
661 
662 static int
663 ptrace_lwpinfo(struct proc *t, struct lwp **lt, void *addr, size_t data)
664 {
665 	struct ptrace_lwpinfo pl;
666 
667 	if (data != sizeof(pl)) {
668 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pl)));
669 		return EINVAL;
670 	}
671 	int error = copyin(addr, &pl, sizeof(pl));
672 	if (error)
673 		return error;
674 
675 	lwpid_t tmp = pl.pl_lwpid;
676 	lwp_delref(*lt);
677 	mutex_enter(t->p_lock);
678 	if (tmp == 0)
679 		*lt = lwp_find_first(t);
680 	else {
681 		*lt = lwp_find(t, tmp);
682 		if (*lt == NULL) {
683 			mutex_exit(t->p_lock);
684 			return ESRCH;
685 		}
686 		*lt = LIST_NEXT(*lt, l_sibling);
687 	}
688 
689 	while (*lt != NULL && !lwp_alive(*lt))
690 		*lt = LIST_NEXT(*lt, l_sibling);
691 
692 	pl.pl_lwpid = 0;
693 	pl.pl_event = 0;
694 	if (*lt) {
695 		lwp_addref(*lt);
696 		pl.pl_lwpid = (*lt)->l_lid;
697 
698 		if ((*lt)->l_flag & LW_WSUSPEND)
699 			pl.pl_event = PL_EVENT_SUSPENDED;
700 		/*
701 		 * If we match the lwp, or it was sent to every lwp,
702 		 * we set PL_EVENT_SIGNAL.
703 		 * XXX: ps_lwp == 0 means everyone and noone, so
704 		 * check ps_signo too.
705 		 */
706 		else if ((*lt)->l_lid == t->p_sigctx.ps_lwp
707 			 || (t->p_sigctx.ps_lwp == 0 &&
708 			     t->p_sigctx.ps_info._signo))
709 			pl.pl_event = PL_EVENT_SIGNAL;
710 	}
711 	mutex_exit(t->p_lock);
712 
713 	return copyout(&pl, addr, sizeof(pl));
714 }
715 
716 static int
717 ptrace_sigmask(struct proc *t, struct lwp **lt, int rq, void *addr, size_t data)
718 {
719 	int error;
720 
721 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
722 		return error;
723 
724 	if (rq == PT_GET_SIGMASK)
725 		return copyout(&(*lt)->l_sigmask, addr, sizeof(sigset_t));
726 
727 	error = copyin(addr, &(*lt)->l_sigmask, sizeof(sigset_t));
728 	if (error)
729 		return error;
730 	sigminusset(&sigcantmask, &(*lt)->l_sigmask);
731 	return 0;
732 }
733 
734 static int
735 ptrace_startstop(struct proc *t, struct lwp **lt, int rq, void *addr,
736     size_t data)
737 {
738 	int error;
739 
740 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
741 		return error;
742 
743 	lwp_lock(*lt);
744 	if (rq == PT_SUSPEND)
745 		(*lt)->l_flag |= LW_WSUSPEND;
746 	else
747 		(*lt)->l_flag &= ~LW_WSUSPEND;
748 	lwp_unlock(*lt);
749 	return 0;
750 }
751 
752 #ifdef PT_REGISTERS
753 static int
754 ptrace_uio_dir(int req)
755 {
756 	switch (req) {
757 	case_PT_GETREGS
758 	case_PT_GETFPREGS
759 	case_PT_GETDBREGS
760 		return UIO_READ;
761 	case_PT_SETREGS
762 	case_PT_SETFPREGS
763 	case_PT_SETDBREGS
764 		return UIO_WRITE;
765 	default:
766 		return -1;
767 	}
768 }
769 
770 static int
771 ptrace_regs(struct lwp *l, struct lwp **lt, int rq, struct ptrace_methods *ptm,
772     void *addr, size_t data)
773 {
774 	int error;
775 	struct proc *t = (*lt)->l_proc;
776 	struct vmspace *vm;
777 
778 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
779 		return error;
780 
781 	int dir = ptrace_uio_dir(rq);
782 	size_t size;
783 	int (*func)(struct lwp *, struct lwp *, struct uio *);
784 
785 	switch (rq) {
786 #if defined(PT_SETREGS) || defined(PT_GETREGS)
787 	case_PT_GETREGS
788 	case_PT_SETREGS
789 		if (!process_validregs(*lt))
790 			return EINVAL;
791 		size = PROC_REGSZ(t);
792 		func = ptm->ptm_doregs;
793 		break;
794 #endif
795 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
796 	case_PT_GETFPREGS
797 	case_PT_SETFPREGS
798 		if (!process_validfpregs(*lt))
799 			return EINVAL;
800 		size = PROC_FPREGSZ(t);
801 		func = ptm->ptm_dofpregs;
802 		break;
803 #endif
804 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
805 	case_PT_GETDBREGS
806 	case_PT_SETDBREGS
807 		if (!process_validdbregs(*lt))
808 			return EINVAL;
809 		size = PROC_DBREGSZ(t);
810 		func = ptm->ptm_dodbregs;
811 		break;
812 #endif
813 	default:
814 		return EINVAL;
815 	}
816 
817 	error = proc_vmspace_getref(l->l_proc, &vm);
818 	if (error)
819 		return error;
820 
821 	struct uio uio;
822 	struct iovec iov;
823 
824 	iov.iov_base = addr;
825 	iov.iov_len = size;
826 	uio.uio_iov = &iov;
827 	uio.uio_iovcnt = 1;
828 	uio.uio_offset = 0;
829 	uio.uio_resid = iov.iov_len;
830 	uio.uio_rw = dir;
831 	uio.uio_vmspace = vm;
832 
833 	error = (*func)(l, *lt, &uio);
834 	uvmspace_free(vm);
835 	return error;
836 }
837 #endif
838 
839 static int
840 ptrace_sendsig(struct proc *t, struct lwp *lt, int signo, int resume_all)
841 {
842 	ksiginfo_t ksi;
843 
844 	t->p_fpid = 0;
845 	t->p_vfpid = 0;
846 	t->p_vfpid_done = 0;
847 	t->p_lwp_created = 0;
848 	t->p_lwp_exited = 0;
849 
850 	/* Finally, deliver the requested signal (or none). */
851 	if (t->p_stat == SSTOP) {
852 		/*
853 		 * Unstop the process.  If it needs to take a
854 		 * signal, make all efforts to ensure that at
855 		 * an LWP runs to see it.
856 		 */
857 		t->p_xsig = signo;
858 		if (resume_all)
859 			proc_unstop(t);
860 		else
861 			lwp_unstop(lt);
862 		return 0;
863 	}
864 
865 	KSI_INIT_EMPTY(&ksi);
866 	if (t->p_sigctx.ps_faked) {
867 		if (signo != t->p_sigctx.ps_info._signo)
868 			return EINVAL;
869 		t->p_sigctx.ps_faked = false;
870 		ksi.ksi_info = t->p_sigctx.ps_info;
871 		ksi.ksi_lid = t->p_sigctx.ps_lwp;
872 	} else if (signo == 0) {
873 		return 0;
874 	} else {
875 		ksi.ksi_signo = signo;
876 	}
877 
878 	kpsignal2(t, &ksi);
879 	return 0;
880 }
881 
882 static int
883 ptrace_dumpcore(struct lwp *lt, char *path, size_t len)
884 {
885 	int error;
886 	if (path != NULL) {
887 
888 		if (len >= MAXPATHLEN)
889 			return EINVAL;
890 
891 		char *src = path;
892 		path = kmem_alloc(len + 1, KM_SLEEP);
893 		error = copyin(src, path, len);
894 		if (error)
895 			goto out;
896 		path[len] = '\0';
897 	}
898 	error = (*coredump_vec)(lt, path);
899 out:
900 	if (path)
901 		kmem_free(path, len + 1);
902 	return error;
903 }
904 
905 static int
906 ptrace_doio(struct lwp *l, struct proc *t, struct lwp *lt,
907     struct ptrace_io_desc *piod, void *addr, bool sysspace)
908 {
909 	struct uio uio;
910 	struct iovec iov;
911 	int error, tmp;
912 
913 	error = 0;
914 	iov.iov_base = piod->piod_addr;
915 	iov.iov_len = piod->piod_len;
916 	uio.uio_iov = &iov;
917 	uio.uio_iovcnt = 1;
918 	uio.uio_offset = (off_t)(unsigned long)piod->piod_offs;
919 	uio.uio_resid = piod->piod_len;
920 
921 	switch (piod->piod_op) {
922 	case PIOD_READ_D:
923 	case PIOD_READ_I:
924 		uio.uio_rw = UIO_READ;
925 		break;
926 	case PIOD_WRITE_D:
927 	case PIOD_WRITE_I:
928 		/*
929 		 * Can't write to a RAS
930 		 */
931 		if (ras_lookup(t, addr) != (void *)-1) {
932 			return EACCES;
933 		}
934 		uio.uio_rw = UIO_WRITE;
935 		break;
936 	case PIOD_READ_AUXV:
937 		uio.uio_rw = UIO_READ;
938 		tmp = t->p_execsw->es_arglen;
939 		if (uio.uio_offset > tmp)
940 			return EIO;
941 		if (uio.uio_resid > tmp - uio.uio_offset)
942 			uio.uio_resid = tmp - uio.uio_offset;
943 		piod->piod_len = iov.iov_len = uio.uio_resid;
944 		error = process_auxv_offset(t, &uio);
945 		break;
946 	default:
947 		error = EINVAL;
948 		break;
949 	}
950 
951 	if (error)
952 		return error;
953 
954 	if (sysspace) {
955 		uio.uio_vmspace = vmspace_kernel();
956 	} else {
957 		error = proc_vmspace_getref(l->l_proc, &uio.uio_vmspace);
958 		if (error)
959 			return error;
960 	}
961 
962 	error = process_domem(l, lt, &uio);
963 	if (!sysspace)
964 		uvmspace_free(uio.uio_vmspace);
965 	if (error)
966 		return error;
967 	piod->piod_len -= uio.uio_resid;
968 	return 0;
969 }
970 
971 int
972 do_ptrace(struct ptrace_methods *ptm, struct lwp *l, int req, pid_t pid,
973     void *addr, int data, register_t *retval)
974 {
975 	struct proc *p = l->l_proc;
976 	struct lwp *lt = NULL;
977 	struct lwp *lt2;
978 	struct proc *t;				/* target process */
979 	struct ptrace_io_desc piod;
980 	int error, write, tmp, pheld;
981 	int signo = 0;
982 	int resume_all;
983 	error = 0;
984 
985 	/*
986 	 * If attaching or detaching, we need to get a write hold on the
987 	 * proclist lock so that we can re-parent the target process.
988 	 */
989 	mutex_enter(proc_lock);
990 
991 	t = ptrace_find(l, req, pid);
992 	if (t == NULL) {
993 		mutex_exit(proc_lock);
994 		return ESRCH;
995 	}
996 
997 	pheld = 1;
998 	if ((error = ptrace_allowed(l, req, t, p)) != 0)
999 		goto out;
1000 
1001 	if ((error = kauth_authorize_process(l->l_cred,
1002 	    KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req), NULL, NULL)) != 0)
1003 		goto out;
1004 
1005 	if ((lt = lwp_find_first(t)) == NULL) {
1006 	    error = ESRCH;
1007 	    goto out;
1008 	}
1009 
1010 	/* Do single-step fixup if needed. */
1011 	FIX_SSTEP(t);
1012 	KASSERT(lt != NULL);
1013 	lwp_addref(lt);
1014 
1015 	/*
1016 	 * Which locks do we need held? XXX Ugly.
1017 	 */
1018 	if ((pheld = ptrace_needs_hold(req)) == 0) {
1019 		mutex_exit(t->p_lock);
1020 		mutex_exit(proc_lock);
1021 	}
1022 
1023 	/* Now do the operation. */
1024 	write = 0;
1025 	*retval = 0;
1026 	tmp = 0;
1027 	resume_all = 1;
1028 
1029 	switch (req) {
1030 	case PT_TRACE_ME:
1031 		/* Just set the trace flag. */
1032 		SET(t->p_slflag, PSL_TRACED);
1033 		t->p_opptr = t->p_pptr;
1034 		break;
1035 
1036 	case PT_WRITE_I:		/* XXX no separate I and D spaces */
1037 	case PT_WRITE_D:
1038 		write = 1;
1039 		tmp = data;
1040 		/* FALLTHROUGH */
1041 	case PT_READ_I:			/* XXX no separate I and D spaces */
1042 	case PT_READ_D:
1043 		piod.piod_addr = &tmp;
1044 		piod.piod_len = sizeof(tmp);
1045 		piod.piod_offs = addr;
1046 		piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D;
1047 		if ((error = ptrace_doio(l, t, lt, &piod, addr, true)) != 0)
1048 			break;
1049 		if (!write)
1050 			*retval = tmp;
1051 		break;
1052 
1053 	case PT_IO:
1054 		if ((error = ptm->ptm_copyin_piod(&piod, addr, data)) != 0)
1055 			break;
1056 		if ((error = ptrace_doio(l, t, lt, &piod, addr, false)) != 0)
1057 			break;
1058 		error = ptm->ptm_copyout_piod(&piod, addr, data);
1059 		break;
1060 
1061 	case PT_DUMPCORE:
1062 		error = ptrace_dumpcore(lt, addr, data);
1063 		break;
1064 
1065 #ifdef PT_STEP
1066 	case PT_STEP:
1067 		/*
1068 		 * From the 4.4BSD PRM:
1069 		 * "Execution continues as in request PT_CONTINUE; however
1070 		 * as soon as possible after execution of at least one
1071 		 * instruction, execution stops again. [ ... ]"
1072 		 */
1073 #endif
1074 	case PT_CONTINUE:
1075 	case PT_SYSCALL:
1076 	case PT_DETACH:
1077 		if (req == PT_SYSCALL) {
1078 			if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
1079 				SET(t->p_slflag, PSL_SYSCALL);
1080 #ifdef __HAVE_SYSCALL_INTERN
1081 				(*t->p_emul->e_syscall_intern)(t);
1082 #endif
1083 			}
1084 		} else {
1085 			if (ISSET(t->p_slflag, PSL_SYSCALL)) {
1086 				CLR(t->p_slflag, PSL_SYSCALL);
1087 #ifdef __HAVE_SYSCALL_INTERN
1088 				(*t->p_emul->e_syscall_intern)(t);
1089 #endif
1090 			}
1091 		}
1092 		t->p_trace_enabled = trace_is_enabled(t);
1093 
1094 		/*
1095 		 * Pick up the LWPID, if supplied.  There are two cases:
1096 		 * data < 0 : step or continue single thread, lwp = -data
1097 		 * data > 0 in PT_STEP : step this thread, continue others
1098 		 * For operations other than PT_STEP, data > 0 means
1099 		 * data is the signo to deliver to the process.
1100 		 */
1101 		tmp = data;
1102 		if (tmp >= 0) {
1103 #ifdef PT_STEP
1104 			if (req == PT_STEP)
1105 				signo = 0;
1106 			else
1107 #endif
1108 			{
1109 				signo = tmp;
1110 				tmp = 0;	/* don't search for LWP */
1111 			}
1112 		} else
1113 			tmp = -tmp;
1114 
1115 		if (tmp > 0) {
1116 			if (req == PT_DETACH) {
1117 				error = EINVAL;
1118 				break;
1119 			}
1120 			lwp_delref2 (lt);
1121 			lt = lwp_find(t, tmp);
1122 			if (lt == NULL) {
1123 				error = ESRCH;
1124 				break;
1125 			}
1126 			lwp_addref(lt);
1127 			resume_all = 0;
1128 			signo = 0;
1129 		}
1130 
1131 		/*
1132 		 * From the 4.4BSD PRM:
1133 		 * "The data argument is taken as a signal number and the
1134 		 * child's execution continues at location addr as if it
1135 		 * incurred that signal.  Normally the signal number will
1136 		 * be either 0 to indicate that the signal that caused the
1137 		 * stop should be ignored, or that value fetched out of
1138 		 * the process's image indicating which signal caused
1139 		 * the stop.  If addr is (int *)1 then execution continues
1140 		 * from where it stopped."
1141 		 */
1142 
1143 		/* Check that the data is a valid signal number or zero. */
1144 		if (signo < 0 || signo >= NSIG) {
1145 			error = EINVAL;
1146 			break;
1147 		}
1148 
1149 		/* Prevent process deadlock */
1150 		if (resume_all) {
1151 #ifdef PT_STEP
1152 			if (req == PT_STEP) {
1153 				if (lt->l_flag & LW_WSUSPEND) {
1154 					error = EDEADLK;
1155 					break;
1156 				}
1157 			} else
1158 #endif
1159 			{
1160 				error = EDEADLK;
1161 				LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1162 					if ((lt2->l_flag & LW_WSUSPEND) == 0) {
1163 						error = 0;
1164 						break;
1165 					}
1166 				}
1167 				if (error != 0)
1168 					break;
1169 			}
1170 		} else {
1171 			if (lt->l_flag & LW_WSUSPEND) {
1172 				error = EDEADLK;
1173 				break;
1174 			}
1175 		}
1176 
1177 		/* If the address parameter is not (int *)1, set the pc. */
1178 		if ((int *)addr != (int *)1) {
1179 			error = process_set_pc(lt, addr);
1180 			if (error != 0)
1181 				break;
1182 		}
1183 #ifdef PT_STEP
1184 		/*
1185 		 * Arrange for a single-step, if that's requested and possible.
1186 		 * More precisely, set the single step status as requested for
1187 		 * the requested thread, and clear it for other threads.
1188 		 */
1189 		LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1190 			if (ISSET(lt2->l_pflag, LP_SINGLESTEP)) {
1191 				lwp_lock(lt2);
1192 				process_sstep(lt2, 1);
1193 				lwp_unlock(lt2);
1194 			} else if (lt != lt2) {
1195 				lwp_lock(lt2);
1196 				process_sstep(lt2, 0);
1197 				lwp_unlock(lt2);
1198 			}
1199 		}
1200 		error = process_sstep(lt,
1201 		    ISSET(lt->l_pflag, LP_SINGLESTEP) || req == PT_STEP);
1202 		if (error)
1203 			break;
1204 #endif
1205 		if (req == PT_DETACH) {
1206 			CLR(t->p_slflag, PSL_TRACED|PSL_SYSCALL);
1207 
1208 			/* give process back to original parent or init */
1209 			if (t->p_opptr != t->p_pptr) {
1210 				struct proc *pp = t->p_opptr;
1211 				proc_reparent(t, pp ? pp : initproc);
1212 			}
1213 
1214 			/* not being traced any more */
1215 			t->p_opptr = NULL;
1216 
1217 			/* clear single step */
1218 			LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1219 				CLR(lt2->l_pflag, LP_SINGLESTEP);
1220 			}
1221 			CLR(lt->l_pflag, LP_SINGLESTEP);
1222 		}
1223 	sendsig:
1224 		error = ptrace_sendsig(t, lt, signo, resume_all);
1225 		break;
1226 
1227 	case PT_SYSCALLEMU:
1228 		if (!ISSET(t->p_slflag, PSL_SYSCALL) || t->p_stat != SSTOP) {
1229 			error = EINVAL;
1230 			break;
1231 		}
1232 		SET(t->p_slflag, PSL_SYSCALLEMU);
1233 		break;
1234 
1235 #ifdef PT_STEP
1236 	case PT_SETSTEP:
1237 		write = 1;
1238 
1239 	case PT_CLEARSTEP:
1240 		/* write = 0 done above. */
1241 		if ((error = ptrace_update_lwp(t, &lt, data)) != 0)
1242 			break;
1243 
1244 		if (write)
1245 			SET(lt->l_pflag, LP_SINGLESTEP);
1246 		else
1247 			CLR(lt->l_pflag, LP_SINGLESTEP);
1248 		break;
1249 #endif
1250 
1251 	case PT_KILL:
1252 		/* just send the process a KILL signal. */
1253 		signo = SIGKILL;
1254 		goto sendsig;	/* in PT_CONTINUE, above. */
1255 
1256 	case PT_ATTACH:
1257 		/*
1258 		 * Go ahead and set the trace flag.
1259 		 * Save the old parent (it's reset in
1260 		 *   _DETACH, and also in kern_exit.c:wait4()
1261 		 * Reparent the process so that the tracing
1262 		 *   proc gets to see all the action.
1263 		 * Stop the target.
1264 		 */
1265 		proc_changeparent(t, p);
1266 		signo = SIGSTOP;
1267 		goto sendsig;
1268 
1269 	case PT_GET_EVENT_MASK:
1270 		error = ptrace_get_event_mask(t, addr, data);
1271 		break;
1272 
1273 	case PT_SET_EVENT_MASK:
1274 		error = ptrace_set_event_mask(t, addr, data);
1275 		break;
1276 
1277 	case PT_GET_PROCESS_STATE:
1278 		error = ptrace_get_process_state(t, addr, data);
1279 		break;
1280 
1281 	case PT_LWPINFO:
1282 		error = ptrace_lwpinfo(t, &lt, addr, data);
1283 		break;
1284 
1285 	case PT_SET_SIGINFO:
1286 		error = ptrace_set_siginfo(t, &lt, ptm, addr, data);
1287 		break;
1288 
1289 	case PT_GET_SIGINFO:
1290 		error = ptrace_get_siginfo(t, ptm, addr, data);
1291 		break;
1292 
1293 	case PT_SET_SIGMASK:
1294 	case PT_GET_SIGMASK:
1295 		error = ptrace_sigmask(t, &lt, req, addr, data);
1296 		break;
1297 
1298 	case PT_RESUME:
1299 	case PT_SUSPEND:
1300 		error = ptrace_startstop(t, &lt, req, addr, data);
1301 		break;
1302 
1303 #ifdef PT_REGISTERS
1304 	case_PT_SETREGS
1305 	case_PT_GETREGS
1306 	case_PT_SETFPREGS
1307 	case_PT_GETFPREGS
1308 	case_PT_SETDBREGS
1309 	case_PT_GETDBREGS
1310 		error = ptrace_regs(l, &lt, req, ptm, addr, data);
1311 		break;
1312 #endif
1313 
1314 #ifdef __HAVE_PTRACE_MACHDEP
1315 	PTRACE_MACHDEP_REQUEST_CASES
1316 		error = ptrace_machdep_dorequest(l, lt, req, addr, data);
1317 		break;
1318 #endif
1319 	}
1320 
1321 out:
1322 	if (pheld) {
1323 		mutex_exit(t->p_lock);
1324 		mutex_exit(proc_lock);
1325 	}
1326 	if (lt != NULL)
1327 		lwp_delref(lt);
1328 	rw_exit(&t->p_reflock);
1329 
1330 	return error;
1331 }
1332 
1333 typedef int (*regrfunc_t)(struct lwp *, void *, size_t *);
1334 typedef int (*regwfunc_t)(struct lwp *, void *, size_t);
1335 
1336 #ifdef PT_REGISTERS
1337 static int
1338 proc_regio(struct lwp *l, struct uio *uio, size_t ks, regrfunc_t r,
1339     regwfunc_t w)
1340 {
1341 	char buf[1024];
1342 	int error;
1343 	char *kv;
1344 	size_t kl;
1345 
1346 	if (ks > sizeof(buf))
1347 		return E2BIG;
1348 
1349 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)ks)
1350 		return EINVAL;
1351 
1352 	kv = buf + uio->uio_offset;
1353 	kl = ks - uio->uio_offset;
1354 
1355 	if (kl > uio->uio_resid)
1356 		kl = uio->uio_resid;
1357 
1358 	error = (*r)(l, buf, &ks);
1359 	if (error == 0)
1360 		error = uiomove(kv, kl, uio);
1361 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1362 		if (l->l_stat != LSSTOP)
1363 			error = EBUSY;
1364 		else
1365 			error = (*w)(l, buf, ks);
1366 	}
1367 
1368 	uio->uio_offset = 0;
1369 	return error;
1370 }
1371 #endif
1372 
1373 int
1374 process_doregs(struct lwp *curl /*tracer*/,
1375     struct lwp *l /*traced*/,
1376     struct uio *uio)
1377 {
1378 #if defined(PT_GETREGS) || defined(PT_SETREGS)
1379 	size_t s;
1380 	regrfunc_t r;
1381 	regwfunc_t w;
1382 
1383 #ifdef COMPAT_NETBSD32
1384 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1385 
1386 	if (__predict_false(pk32)) {
1387 		s = sizeof(process_reg32);
1388 		r = (regrfunc_t)process_read_regs32;
1389 		w = (regwfunc_t)process_write_regs32;
1390 	} else
1391 #endif
1392 	{
1393 		s = sizeof(struct reg);
1394 		r = (regrfunc_t)process_read_regs;
1395 		w = (regwfunc_t)process_write_regs;
1396 	}
1397 	return proc_regio(l, uio, s, r, w);
1398 #else
1399 	return EINVAL;
1400 #endif
1401 }
1402 
1403 int
1404 process_validregs(struct lwp *l)
1405 {
1406 
1407 #if defined(PT_SETREGS) || defined(PT_GETREGS)
1408 	return (l->l_flag & LW_SYSTEM) == 0;
1409 #else
1410 	return 0;
1411 #endif
1412 }
1413 
1414 int
1415 process_dofpregs(struct lwp *curl /*tracer*/,
1416     struct lwp *l /*traced*/,
1417     struct uio *uio)
1418 {
1419 #if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
1420 	size_t s;
1421 	regrfunc_t r;
1422 	regwfunc_t w;
1423 
1424 #ifdef COMPAT_NETBSD32
1425 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1426 
1427 	if (__predict_false(pk32)) {
1428 		s = sizeof(process_fpreg32);
1429 		r = (regrfunc_t)process_read_fpregs32;
1430 		w = (regwfunc_t)process_write_fpregs32;
1431 	} else
1432 #endif
1433 	{
1434 		s = sizeof(struct fpreg);
1435 		r = (regrfunc_t)process_read_fpregs;
1436 		w = (regwfunc_t)process_write_fpregs;
1437 	}
1438 	return proc_regio(l, uio, s, r, w);
1439 #else
1440 	return EINVAL;
1441 #endif
1442 }
1443 
1444 int
1445 process_validfpregs(struct lwp *l)
1446 {
1447 
1448 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
1449 	return (l->l_flag & LW_SYSTEM) == 0;
1450 #else
1451 	return 0;
1452 #endif
1453 }
1454 
1455 int
1456 process_dodbregs(struct lwp *curl /*tracer*/,
1457     struct lwp *l /*traced*/,
1458     struct uio *uio)
1459 {
1460 #if defined(PT_GETDBREGS) || defined(PT_SETDBREGS)
1461 	size_t s;
1462 	regrfunc_t r;
1463 	regwfunc_t w;
1464 
1465 #ifdef COMPAT_NETBSD32
1466 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1467 
1468 	if (__predict_false(pk32)) {
1469 		s = sizeof(process_dbreg32);
1470 		r = (regrfunc_t)process_read_dbregs32;
1471 		w = (regwfunc_t)process_write_dbregs32;
1472 	} else
1473 #endif
1474 	{
1475 		s = sizeof(struct dbreg);
1476 		r = (regrfunc_t)process_read_dbregs;
1477 		w = (regwfunc_t)process_write_dbregs;
1478 	}
1479 	return proc_regio(l, uio, s, r, w);
1480 #else
1481 	return EINVAL;
1482 #endif
1483 }
1484 
1485 int
1486 process_validdbregs(struct lwp *l)
1487 {
1488 
1489 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
1490 	return (l->l_flag & LW_SYSTEM) == 0;
1491 #else
1492 	return 0;
1493 #endif
1494 }
1495 
1496 static int
1497 process_auxv_offset(struct proc *p, struct uio *uio)
1498 {
1499 	struct ps_strings pss;
1500 	int error;
1501 	off_t off = (off_t)p->p_psstrp;
1502 
1503 	if ((error = copyin_psstrings(p, &pss)) != 0)
1504 		return error;
1505 
1506 	if (pss.ps_envstr == NULL)
1507 		return EIO;
1508 
1509 	uio->uio_offset += (off_t)(vaddr_t)(pss.ps_envstr + pss.ps_nenvstr + 1);
1510 #ifdef __MACHINE_STACK_GROWS_UP
1511 	if (uio->uio_offset < off)
1512 		return EIO;
1513 #else
1514 	if (uio->uio_offset > off)
1515 		return EIO;
1516 	if ((uio->uio_offset + uio->uio_resid) > off)
1517 		uio->uio_resid = off - uio->uio_offset;
1518 #endif
1519 	return 0;
1520 }
1521 #endif /* PTRACE */
1522 
1523 MODULE(MODULE_CLASS_EXEC, ptrace_common, "");
1524 
1525 static int
1526 ptrace_common_modcmd(modcmd_t cmd, void *arg)
1527 {
1528         int error;
1529 
1530         switch (cmd) {
1531         case MODULE_CMD_INIT:
1532                 error = ptrace_init();
1533                 break;
1534         case MODULE_CMD_FINI:
1535                 error = ptrace_fini();
1536                 break;
1537         default:
1538 		ptrace_hooks();
1539                 error = ENOTTY;
1540                 break;
1541         }
1542         return error;
1543 }
1544