xref: /netbsd-src/sys/kern/sys_ptrace_common.c (revision 06d8aeb822e8ca87302d029eddc6e17d1f12a4d5)
1 /*	$NetBSD: sys_ptrace_common.c,v 1.38 2018/04/29 04:28:09 kamil 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 1.38 2018/04/29 04:28:09 kamil 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 #ifdef PT_SETDBREGS
222 	extern int user_set_dbregs;
223 #endif
224 
225 	result = KAUTH_RESULT_DEFER;
226 	p = arg0;
227 
228 #if 0
229 	mutex_enter(&ptrace_mtx);
230 	ptrace_cbref++;
231 	mutex_exit(&ptrace_mtx);
232 #endif
233 	if (action != KAUTH_PROCESS_PTRACE)
234 		goto out;
235 
236 	switch ((u_long)arg1) {
237 #ifdef PT_SETDBREGS
238 	case_PT_SETDBREGS
239 		if (kauth_cred_getuid(cred) != 0 && user_set_dbregs == 0) {
240 			result = KAUTH_RESULT_DENY;
241 			break;
242 		}
243 #endif
244 	case PT_TRACE_ME:
245 	case PT_ATTACH:
246 	case PT_WRITE_I:
247 	case PT_WRITE_D:
248 	case PT_READ_I:
249 	case PT_READ_D:
250 	case PT_IO:
251 	case_PT_GETREGS
252 	case_PT_SETREGS
253 	case_PT_GETFPREGS
254 	case_PT_SETFPREGS
255 	case_PT_GETDBREGS
256 	case PT_SET_EVENT_MASK:
257 	case PT_GET_EVENT_MASK:
258 	case PT_GET_PROCESS_STATE:
259 	case PT_SET_SIGINFO:
260 	case PT_GET_SIGINFO:
261 #ifdef __HAVE_PTRACE_MACHDEP
262 	PTRACE_MACHDEP_REQUEST_CASES
263 #endif
264 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
265 		    ISSET(p->p_flag, PK_SUGID)) {
266 			break;
267 		}
268 
269 		result = KAUTH_RESULT_ALLOW;
270 
271 	break;
272 
273 #ifdef PT_STEP
274 	case PT_STEP:
275 	case PT_SETSTEP:
276 	case PT_CLEARSTEP:
277 #endif
278 	case PT_CONTINUE:
279 	case PT_KILL:
280 	case PT_DETACH:
281 	case PT_LWPINFO:
282 	case PT_SYSCALL:
283 	case PT_SYSCALLEMU:
284 	case PT_DUMPCORE:
285 	case PT_RESUME:
286 	case PT_SUSPEND:
287 		result = KAUTH_RESULT_ALLOW;
288 		break;
289 
290 	default:
291 		break;
292 	}
293 
294  out:
295 #if 0
296 	mutex_enter(&ptrace_mtx);
297 	if (--ptrace_cbref == 0)
298 		cv_broadcast(&ptrace_cv);
299 	mutex_exit(&ptrace_mtx);
300 #endif
301 
302 	return result;
303 }
304 
305 int
306 ptrace_init(void)
307 {
308 
309 #if 0
310 	mutex_init(&ptrace_mtx, MUTEX_DEFAULT, IPL_NONE);
311 	cv_init(&ptrace_cv, "ptracecb");
312 	ptrace_cbref = 0;
313 #endif
314 	ptrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
315 	    ptrace_listener_cb, NULL);
316 	return 0;
317 }
318 
319 int
320 ptrace_fini(void)
321 {
322 
323 	kauth_unlisten_scope(ptrace_listener);
324 
325 #if 0
326 	/* Make sure no-one is executing our kauth listener */
327 
328 	mutex_enter(&ptrace_mtx);
329 	while (ptrace_cbref != 0)
330 		cv_wait(&ptrace_cv, &ptrace_mtx);
331 	mutex_exit(&ptrace_mtx);
332 	mutex_destroy(&ptrace_mtx);
333 	cv_destroy(&ptrace_cv);
334 #endif
335 
336 	return 0;
337 }
338 
339 static struct proc *
340 ptrace_find(struct lwp *l, int req, pid_t pid)
341 {
342 	struct proc *t;
343 
344 	/* "A foolish consistency..." XXX */
345 	if (req == PT_TRACE_ME) {
346 		t = l->l_proc;
347 		mutex_enter(t->p_lock);
348 		return t;
349 	}
350 
351 	/* Find the process we're supposed to be operating on. */
352 	t = proc_find(pid);
353 	if (t == NULL)
354 		return NULL;
355 
356 	/* XXX-elad */
357 	mutex_enter(t->p_lock);
358 	int error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
359 	    t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
360 	if (error) {
361 		mutex_exit(t->p_lock);
362 		return NULL;
363 	}
364 	return t;
365 }
366 
367 static int
368 ptrace_allowed(struct lwp *l, int req, struct proc *t, struct proc *p)
369 {
370 	/*
371 	 * Grab a reference on the process to prevent it from execing or
372 	 * exiting.
373 	 */
374 	if (!rw_tryenter(&t->p_reflock, RW_READER))
375 		return EBUSY;
376 
377 	/* Make sure we can operate on it. */
378 	switch (req) {
379 	case PT_TRACE_ME:
380 		/*
381 		 * You can't say to the parent of a process to start tracing if:
382 		 *	(1) the parent is initproc,
383 		 */
384 		if (p->p_pptr == initproc)
385 			return EPERM;
386 
387 		/*
388 		 *	(2) the child is already traced.
389 		 */
390 		if (ISSET(p->p_slflag, PSL_TRACED))
391 			return EBUSY;
392 
393 		return 0;
394 
395 	case PT_ATTACH:
396 		/*
397 		 * You can't attach to a process if:
398 		 *	(1) it's the process that's doing the attaching,
399 		 */
400 		if (t->p_pid == p->p_pid)
401 			return EINVAL;
402 
403 		/*
404 		 *	(2) it's a system process
405 		 */
406 		if (t->p_flag & PK_SYSTEM)
407 			return EPERM;
408 
409 		/*
410 		 *	(3) it's already being traced, or
411 		 */
412 		if (ISSET(t->p_slflag, PSL_TRACED))
413 			return EBUSY;
414 
415 		/*
416 		 * 	(4) the tracer is chrooted, and its root directory is
417 		 * 	    not at or above the root directory of the tracee
418 		 */
419 		mutex_exit(t->p_lock);	/* XXXSMP */
420 		int tmp = proc_isunder(t, l);
421 		mutex_enter(t->p_lock);	/* XXXSMP */
422 		if (!tmp)
423 			return EPERM;
424 		return 0;
425 
426 	case PT_READ_I:
427 	case PT_READ_D:
428 	case PT_WRITE_I:
429 	case PT_WRITE_D:
430 	case PT_IO:
431 	case PT_SET_SIGINFO:
432 	case PT_GET_SIGINFO:
433 	case_PT_GETREGS
434 	case_PT_SETREGS
435 	case_PT_GETFPREGS
436 	case_PT_SETFPREGS
437 	case_PT_GETDBREGS
438 	case_PT_SETDBREGS
439 #ifdef __HAVE_PTRACE_MACHDEP
440 	PTRACE_MACHDEP_REQUEST_CASES
441 #endif
442 		/*
443 		 * You can't read/write the memory or registers of a process
444 		 * if the tracer is chrooted, and its root directory is not at
445 		 * or above the root directory of the tracee.
446 		 */
447 		mutex_exit(t->p_lock);	/* XXXSMP */
448 		tmp = proc_isunder(t, l);
449 		mutex_enter(t->p_lock);	/* XXXSMP */
450 		if (!tmp)
451 			return EPERM;
452 		/*FALLTHROUGH*/
453 
454 	case PT_CONTINUE:
455 	case PT_KILL:
456 	case PT_DETACH:
457 	case PT_LWPINFO:
458 	case PT_SYSCALL:
459 	case PT_SYSCALLEMU:
460 	case PT_DUMPCORE:
461 #ifdef PT_STEP
462 	case PT_STEP:
463 	case PT_SETSTEP:
464 	case PT_CLEARSTEP:
465 #endif
466 	case PT_SET_EVENT_MASK:
467 	case PT_GET_EVENT_MASK:
468 	case PT_GET_PROCESS_STATE:
469 	case PT_RESUME:
470 	case PT_SUSPEND:
471 		/*
472 		 * You can't do what you want to the process if:
473 		 *	(1) It's not being traced at all,
474 		 */
475 		if (!ISSET(t->p_slflag, PSL_TRACED))
476 			return EPERM;
477 
478 		/*
479 		 *	(2) it's not being traced by _you_, or
480 		 */
481 		if (t->p_pptr != p) {
482 			DPRINTF(("parent %d != %d\n", t->p_pptr->p_pid,
483 			    p->p_pid));
484 			return EBUSY;
485 		}
486 
487 		/*
488 		 *	(3) it's not currently stopped.
489 		 */
490 		if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) {
491 			DPRINTF(("stat %d flag %d\n", t->p_stat,
492 			    !t->p_waited));
493 			return EBUSY;
494 		}
495 		return 0;
496 
497 	default:			/* It was not a legal request. */
498 		return EINVAL;
499 	}
500 }
501 
502 static int
503 ptrace_needs_hold(int req)
504 {
505 	switch (req) {
506 #ifdef PT_STEP
507 	case PT_STEP:
508 #endif
509 	case PT_CONTINUE:
510 	case PT_DETACH:
511 	case PT_KILL:
512 	case PT_SYSCALL:
513 	case PT_SYSCALLEMU:
514 	case PT_ATTACH:
515 	case PT_TRACE_ME:
516 	case PT_GET_SIGINFO:
517 	case PT_SET_SIGINFO:
518 		return 1;
519 	default:
520 		return 0;
521 	}
522 }
523 
524 static int
525 ptrace_update_lwp(struct proc *t, struct lwp **lt, lwpid_t lid)
526 {
527 	if (lid == 0 || lid == (*lt)->l_lid || t->p_nlwps == 1)
528 		return 0;
529 
530 	lwp_delref(*lt);
531 
532 	mutex_enter(t->p_lock);
533 	*lt = lwp_find(t, lid);
534 	if (*lt == NULL) {
535 		mutex_exit(t->p_lock);
536 		return ESRCH;
537 	}
538 
539 	if ((*lt)->l_flag & LW_SYSTEM) {
540 		*lt = NULL;
541 		return EINVAL;
542 	}
543 
544 	lwp_addref(*lt);
545 	mutex_exit(t->p_lock);
546 
547 	return 0;
548 }
549 
550 static int
551 ptrace_get_siginfo(struct proc *t, struct ptrace_methods *ptm, void *addr,
552     size_t data)
553 {
554 	struct ptrace_siginfo psi;
555 
556 	psi.psi_siginfo._info = t->p_sigctx.ps_info;
557 	psi.psi_lwpid = t->p_sigctx.ps_lwp;
558 
559 	return ptm->ptm_copyout_siginfo(&psi, addr, data);
560 }
561 
562 static int
563 ptrace_set_siginfo(struct proc *t, struct lwp **lt, struct ptrace_methods *ptm,
564     void *addr, size_t data)
565 {
566 	struct ptrace_siginfo psi;
567 
568 	int error = ptm->ptm_copyin_siginfo(&psi, addr, data);
569 	if (error)
570 		return error;
571 
572 	/* Check that the data is a valid signal number or zero. */
573 	if (psi.psi_siginfo.si_signo < 0 || psi.psi_siginfo.si_signo >= NSIG)
574 		return EINVAL;
575 
576 	if ((error = ptrace_update_lwp(t, lt, psi.psi_lwpid)) != 0)
577 		return error;
578 
579 	t->p_sigctx.ps_faked = true;
580 	t->p_sigctx.ps_info = psi.psi_siginfo._info;
581 	t->p_sigctx.ps_lwp = psi.psi_lwpid;
582 	return 0;
583 }
584 
585 static int
586 ptrace_get_event_mask(struct proc *t, void *addr, size_t data)
587 {
588 	struct ptrace_event pe;
589 
590 	if (data != sizeof(pe)) {
591 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
592 		return EINVAL;
593 	}
594 	memset(&pe, 0, sizeof(pe));
595 	pe.pe_set_event = ISSET(t->p_slflag, PSL_TRACEFORK) ?
596 	    PTRACE_FORK : 0;
597 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK) ?
598 	    PTRACE_VFORK : 0;
599 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK_DONE) ?
600 	    PTRACE_VFORK_DONE : 0;
601 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_CREATE) ?
602 	    PTRACE_LWP_CREATE : 0;
603 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_EXIT) ?
604 	    PTRACE_LWP_EXIT : 0;
605 	return copyout(&pe, addr, sizeof(pe));
606 }
607 
608 static int
609 ptrace_set_event_mask(struct proc *t, void *addr, size_t data)
610 {
611 	struct ptrace_event pe;
612 	int error;
613 
614 	if (data != sizeof(pe)) {
615 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
616 		return EINVAL;
617 	}
618 	if ((error = copyin(addr, &pe, sizeof(pe))) != 0)
619 		return error;
620 
621 	if (pe.pe_set_event & PTRACE_FORK)
622 		SET(t->p_slflag, PSL_TRACEFORK);
623 	else
624 		CLR(t->p_slflag, PSL_TRACEFORK);
625 #if notyet
626 	if (pe.pe_set_event & PTRACE_VFORK)
627 		SET(t->p_slflag, PSL_TRACEVFORK);
628 	else
629 		CLR(t->p_slflag, PSL_TRACEVFORK);
630 #else
631 	if (pe.pe_set_event & PTRACE_VFORK)
632 		return ENOTSUP;
633 #endif
634 	if (pe.pe_set_event & PTRACE_VFORK_DONE)
635 		SET(t->p_slflag, PSL_TRACEVFORK_DONE);
636 	else
637 		CLR(t->p_slflag, PSL_TRACEVFORK_DONE);
638 	if (pe.pe_set_event & PTRACE_LWP_CREATE)
639 		SET(t->p_slflag, PSL_TRACELWP_CREATE);
640 	else
641 		CLR(t->p_slflag, PSL_TRACELWP_CREATE);
642 	if (pe.pe_set_event & PTRACE_LWP_EXIT)
643 		SET(t->p_slflag, PSL_TRACELWP_EXIT);
644 	else
645 		CLR(t->p_slflag, PSL_TRACELWP_EXIT);
646 	return 0;
647 }
648 
649 static int
650 ptrace_get_process_state(struct proc *t, void *addr, size_t data)
651 {
652 	struct ptrace_state ps;
653 
654 	if (data != sizeof(ps)) {
655 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(ps)));
656 		return EINVAL;
657 	}
658 	memset(&ps, 0, sizeof(ps));
659 
660 	if (t->p_fpid) {
661 		ps.pe_report_event = PTRACE_FORK;
662 		ps.pe_other_pid = t->p_fpid;
663 	} else if (t->p_vfpid) {
664 		ps.pe_report_event = PTRACE_VFORK;
665 		ps.pe_other_pid = t->p_vfpid;
666 	} else if (t->p_vfpid_done) {
667 		ps.pe_report_event = PTRACE_VFORK_DONE;
668 		ps.pe_other_pid = t->p_vfpid_done;
669 	} else if (t->p_lwp_created) {
670 		ps.pe_report_event = PTRACE_LWP_CREATE;
671 		ps.pe_lwp = t->p_lwp_created;
672 	} else if (t->p_lwp_exited) {
673 		ps.pe_report_event = PTRACE_LWP_EXIT;
674 		ps.pe_lwp = t->p_lwp_exited;
675 	}
676 	return copyout(&ps, addr, sizeof(ps));
677 }
678 
679 static int
680 ptrace_lwpinfo(struct proc *t, struct lwp **lt, void *addr, size_t data)
681 {
682 	struct ptrace_lwpinfo pl;
683 
684 	if (data != sizeof(pl)) {
685 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pl)));
686 		return EINVAL;
687 	}
688 	int error = copyin(addr, &pl, sizeof(pl));
689 	if (error)
690 		return error;
691 
692 	lwpid_t tmp = pl.pl_lwpid;
693 	lwp_delref(*lt);
694 	mutex_enter(t->p_lock);
695 	if (tmp == 0)
696 		*lt = lwp_find_first(t);
697 	else {
698 		*lt = lwp_find(t, tmp);
699 		if (*lt == NULL) {
700 			mutex_exit(t->p_lock);
701 			return ESRCH;
702 		}
703 		*lt = LIST_NEXT(*lt, l_sibling);
704 	}
705 
706 	while (*lt != NULL && !lwp_alive(*lt))
707 		*lt = LIST_NEXT(*lt, l_sibling);
708 
709 	pl.pl_lwpid = 0;
710 	pl.pl_event = 0;
711 	if (*lt) {
712 		lwp_addref(*lt);
713 		pl.pl_lwpid = (*lt)->l_lid;
714 
715 		if ((*lt)->l_flag & LW_WSUSPEND)
716 			pl.pl_event = PL_EVENT_SUSPENDED;
717 		/*
718 		 * If we match the lwp, or it was sent to every lwp,
719 		 * we set PL_EVENT_SIGNAL.
720 		 * XXX: ps_lwp == 0 means everyone and noone, so
721 		 * check ps_signo too.
722 		 */
723 		else if ((*lt)->l_lid == t->p_sigctx.ps_lwp
724 			 || (t->p_sigctx.ps_lwp == 0 &&
725 			     t->p_sigctx.ps_info._signo))
726 			pl.pl_event = PL_EVENT_SIGNAL;
727 	}
728 	mutex_exit(t->p_lock);
729 
730 	return copyout(&pl, addr, sizeof(pl));
731 }
732 
733 static int
734 ptrace_startstop(struct proc *t, struct lwp **lt, int rq, void *addr,
735     size_t data)
736 {
737 	int error;
738 
739 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
740 		return error;
741 
742 	lwp_lock(*lt);
743 	if (rq == PT_SUSPEND)
744 		(*lt)->l_flag |= LW_WSUSPEND;
745 	else
746 		(*lt)->l_flag &= ~LW_WSUSPEND;
747 	lwp_unlock(*lt);
748 	return 0;
749 }
750 
751 #ifdef PT_REGISTERS
752 static int
753 ptrace_uio_dir(int req)
754 {
755 	switch (req) {
756 	case_PT_GETREGS
757 	case_PT_GETFPREGS
758 	case_PT_GETDBREGS
759 		return UIO_READ;
760 	case_PT_SETREGS
761 	case_PT_SETFPREGS
762 	case_PT_SETDBREGS
763 		return UIO_WRITE;
764 	default:
765 		return -1;
766 	}
767 }
768 
769 static int
770 ptrace_regs(struct lwp *l, struct lwp **lt, int rq, struct ptrace_methods *ptm,
771     void *addr, size_t data)
772 {
773 	int error;
774 	struct proc *t = (*lt)->l_proc;
775 	struct vmspace *vm;
776 
777 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
778 		return error;
779 
780 	int dir = ptrace_uio_dir(rq);
781 	size_t size;
782 	int (*func)(struct lwp *, struct lwp *, struct uio *);
783 
784 	switch (rq) {
785 #if defined(PT_SETREGS) || defined(PT_GETREGS)
786 	case_PT_GETREGS
787 	case_PT_SETREGS
788 		if (!process_validregs(*lt))
789 			return EINVAL;
790 		size = PROC_REGSZ(t);
791 		func = ptm->ptm_doregs;
792 		break;
793 #endif
794 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
795 	case_PT_GETFPREGS
796 	case_PT_SETFPREGS
797 		if (!process_validfpregs(*lt))
798 			return EINVAL;
799 		size = PROC_FPREGSZ(t);
800 		func = ptm->ptm_dofpregs;
801 		break;
802 #endif
803 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
804 	case_PT_GETDBREGS
805 	case_PT_SETDBREGS
806 		if (!process_validdbregs(*lt))
807 			return EINVAL;
808 		size = PROC_DBREGSZ(t);
809 		func = ptm->ptm_dodbregs;
810 		break;
811 #endif
812 	default:
813 		return EINVAL;
814 	}
815 
816 	error = proc_vmspace_getref(l->l_proc, &vm);
817 	if (error)
818 		return error;
819 
820 	struct uio uio;
821 	struct iovec iov;
822 
823 	iov.iov_base = addr;
824 	iov.iov_len = size;
825 	uio.uio_iov = &iov;
826 	uio.uio_iovcnt = 1;
827 	uio.uio_offset = 0;
828 	uio.uio_resid = iov.iov_len;
829 	uio.uio_rw = dir;
830 	uio.uio_vmspace = vm;
831 
832 	error = (*func)(l, *lt, &uio);
833 	uvmspace_free(vm);
834 	return error;
835 }
836 #endif
837 
838 static int
839 ptrace_sendsig(struct proc *t, struct lwp *lt, int signo, int resume_all)
840 {
841 	ksiginfo_t ksi;
842 
843 	t->p_fpid = 0;
844 	t->p_vfpid = 0;
845 	t->p_vfpid_done = 0;
846 	t->p_lwp_created = 0;
847 	t->p_lwp_exited = 0;
848 
849 	/* Finally, deliver the requested signal (or none). */
850 	if (t->p_stat == SSTOP) {
851 		/*
852 		 * Unstop the process.  If it needs to take a
853 		 * signal, make all efforts to ensure that at
854 		 * an LWP runs to see it.
855 		 */
856 		t->p_xsig = signo;
857 		if (resume_all)
858 			proc_unstop(t);
859 		else
860 			lwp_unstop(lt);
861 		return 0;
862 	}
863 
864 	KSI_INIT_EMPTY(&ksi);
865 	if (t->p_sigctx.ps_faked) {
866 		if (signo != t->p_sigctx.ps_info._signo)
867 			return EINVAL;
868 		t->p_sigctx.ps_faked = false;
869 		ksi.ksi_info = t->p_sigctx.ps_info;
870 		ksi.ksi_lid = t->p_sigctx.ps_lwp;
871 	} else if (signo == 0) {
872 		return 0;
873 	} else {
874 		ksi.ksi_signo = signo;
875 	}
876 
877 	kpsignal2(t, &ksi);
878 	return 0;
879 }
880 
881 static int
882 ptrace_dumpcore(struct lwp *lt, char *path, size_t len)
883 {
884 	int error;
885 	if (path != NULL) {
886 
887 		if (len >= MAXPATHLEN)
888 			return EINVAL;
889 
890 		char *src = path;
891 		path = kmem_alloc(len + 1, KM_SLEEP);
892 		error = copyin(src, path, len);
893 		if (error)
894 			goto out;
895 		path[len] = '\0';
896 	}
897 	error = (*coredump_vec)(lt, path);
898 out:
899 	if (path)
900 		kmem_free(path, len + 1);
901 	return error;
902 }
903 
904 static int
905 ptrace_doio(struct lwp *l, struct proc *t, struct lwp *lt,
906     struct ptrace_io_desc *piod, void *addr, bool sysspace)
907 {
908 	struct uio uio;
909 	struct iovec iov;
910 	int error, tmp;
911 
912 	error = 0;
913 	iov.iov_base = piod->piod_addr;
914 	iov.iov_len = piod->piod_len;
915 	uio.uio_iov = &iov;
916 	uio.uio_iovcnt = 1;
917 	uio.uio_offset = (off_t)(unsigned long)piod->piod_offs;
918 	uio.uio_resid = piod->piod_len;
919 
920 	switch (piod->piod_op) {
921 	case PIOD_READ_D:
922 	case PIOD_READ_I:
923 		uio.uio_rw = UIO_READ;
924 		break;
925 	case PIOD_WRITE_D:
926 	case PIOD_WRITE_I:
927 		/*
928 		 * Can't write to a RAS
929 		 */
930 		if (ras_lookup(t, addr) != (void *)-1) {
931 			return EACCES;
932 		}
933 		uio.uio_rw = UIO_WRITE;
934 		break;
935 	case PIOD_READ_AUXV:
936 		uio.uio_rw = UIO_READ;
937 		tmp = t->p_execsw->es_arglen;
938 		if (uio.uio_offset > tmp)
939 			return EIO;
940 		if (uio.uio_resid > tmp - uio.uio_offset)
941 			uio.uio_resid = tmp - uio.uio_offset;
942 		piod->piod_len = iov.iov_len = uio.uio_resid;
943 		error = process_auxv_offset(t, &uio);
944 		break;
945 	default:
946 		error = EINVAL;
947 		break;
948 	}
949 
950 	if (error)
951 		return error;
952 
953 	if (sysspace) {
954 		uio.uio_vmspace = vmspace_kernel();
955 	} else {
956 		error = proc_vmspace_getref(l->l_proc, &uio.uio_vmspace);
957 		if (error)
958 			return error;
959 	}
960 
961 	error = process_domem(l, lt, &uio);
962 	if (!sysspace)
963 		uvmspace_free(uio.uio_vmspace);
964 	if (error)
965 		return error;
966 	piod->piod_len -= uio.uio_resid;
967 	return 0;
968 }
969 
970 int
971 do_ptrace(struct ptrace_methods *ptm, struct lwp *l, int req, pid_t pid,
972     void *addr, int data, register_t *retval)
973 {
974 	struct proc *p = l->l_proc;
975 	struct lwp *lt = NULL;
976 	struct lwp *lt2;
977 	struct proc *t;				/* target process */
978 	struct ptrace_io_desc piod;
979 	int error, write, tmp, pheld;
980 	int signo = 0;
981 	int resume_all;
982 	error = 0;
983 
984 	/*
985 	 * If attaching or detaching, we need to get a write hold on the
986 	 * proclist lock so that we can re-parent the target process.
987 	 */
988 	mutex_enter(proc_lock);
989 
990 	t = ptrace_find(l, req, pid);
991 	if (t == NULL) {
992 		mutex_exit(proc_lock);
993 		return ESRCH;
994 	}
995 
996 	pheld = 1;
997 	if ((error = ptrace_allowed(l, req, t, p)) != 0)
998 		goto out;
999 
1000 	if ((error = kauth_authorize_process(l->l_cred,
1001 	    KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req), NULL, NULL)) != 0)
1002 		goto out;
1003 
1004 	if ((lt = lwp_find_first(t)) == NULL) {
1005 	    error = ESRCH;
1006 	    goto out;
1007 	}
1008 
1009 	/* Do single-step fixup if needed. */
1010 	FIX_SSTEP(t);
1011 	KASSERT(lt != NULL);
1012 	lwp_addref(lt);
1013 
1014 	/*
1015 	 * Which locks do we need held? XXX Ugly.
1016 	 */
1017 	if ((pheld = ptrace_needs_hold(req)) == 0) {
1018 		mutex_exit(t->p_lock);
1019 		mutex_exit(proc_lock);
1020 	}
1021 
1022 	/* Now do the operation. */
1023 	write = 0;
1024 	*retval = 0;
1025 	tmp = 0;
1026 	resume_all = 1;
1027 
1028 	switch (req) {
1029 	case PT_TRACE_ME:
1030 		/* Just set the trace flag. */
1031 		SET(t->p_slflag, PSL_TRACED);
1032 		t->p_opptr = t->p_pptr;
1033 		break;
1034 
1035 	/*
1036 	 * The I and D separate address space has been inherited from PDP-11.
1037 	 * The 16-bit UNIX started with a single address space per program,
1038 	 * but was extended to two 16-bit (2 x 64kb) address spaces.
1039 	 *
1040 	 * We no longer maintain this feature in maintained architectures, but
1041 	 * we keep the API for backward compatiblity. Currently the I and D
1042 	 * operations are exactly the same and not distinguished in debuggers.
1043 	 */
1044 	case PT_WRITE_I:
1045 	case PT_WRITE_D:
1046 		write = 1;
1047 		tmp = data;
1048 		/* FALLTHROUGH */
1049 	case PT_READ_I:
1050 	case PT_READ_D:
1051 		piod.piod_addr = &tmp;
1052 		piod.piod_len = sizeof(tmp);
1053 		piod.piod_offs = addr;
1054 		piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D;
1055 		if ((error = ptrace_doio(l, t, lt, &piod, addr, true)) != 0)
1056 			break;
1057 		if (!write)
1058 			*retval = tmp;
1059 		break;
1060 
1061 	case PT_IO:
1062 		if ((error = ptm->ptm_copyin_piod(&piod, addr, data)) != 0)
1063 			break;
1064 		if ((error = ptrace_doio(l, t, lt, &piod, addr, false)) != 0)
1065 			break;
1066 		error = ptm->ptm_copyout_piod(&piod, addr, data);
1067 		break;
1068 
1069 	case PT_DUMPCORE:
1070 		error = ptrace_dumpcore(lt, addr, data);
1071 		break;
1072 
1073 #ifdef PT_STEP
1074 	case PT_STEP:
1075 		/*
1076 		 * From the 4.4BSD PRM:
1077 		 * "Execution continues as in request PT_CONTINUE; however
1078 		 * as soon as possible after execution of at least one
1079 		 * instruction, execution stops again. [ ... ]"
1080 		 */
1081 #endif
1082 	case PT_CONTINUE:
1083 	case PT_SYSCALL:
1084 	case PT_DETACH:
1085 		if (req == PT_SYSCALL) {
1086 			if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
1087 				SET(t->p_slflag, PSL_SYSCALL);
1088 #ifdef __HAVE_SYSCALL_INTERN
1089 				(*t->p_emul->e_syscall_intern)(t);
1090 #endif
1091 			}
1092 		} else {
1093 			if (ISSET(t->p_slflag, PSL_SYSCALL)) {
1094 				CLR(t->p_slflag, PSL_SYSCALL);
1095 #ifdef __HAVE_SYSCALL_INTERN
1096 				(*t->p_emul->e_syscall_intern)(t);
1097 #endif
1098 			}
1099 		}
1100 		t->p_trace_enabled = trace_is_enabled(t);
1101 
1102 		/*
1103 		 * Pick up the LWPID, if supplied.  There are two cases:
1104 		 * data < 0 : step or continue single thread, lwp = -data
1105 		 * data > 0 in PT_STEP : step this thread, continue others
1106 		 * For operations other than PT_STEP, data > 0 means
1107 		 * data is the signo to deliver to the process.
1108 		 */
1109 		tmp = data;
1110 		if (tmp >= 0) {
1111 #ifdef PT_STEP
1112 			if (req == PT_STEP)
1113 				signo = 0;
1114 			else
1115 #endif
1116 			{
1117 				signo = tmp;
1118 				tmp = 0;	/* don't search for LWP */
1119 			}
1120 		} else
1121 			tmp = -tmp;
1122 
1123 		if (tmp > 0) {
1124 			if (req == PT_DETACH) {
1125 				error = EINVAL;
1126 				break;
1127 			}
1128 			lwp_delref2 (lt);
1129 			lt = lwp_find(t, tmp);
1130 			if (lt == NULL) {
1131 				error = ESRCH;
1132 				break;
1133 			}
1134 			lwp_addref(lt);
1135 			resume_all = 0;
1136 			signo = 0;
1137 		}
1138 
1139 		/*
1140 		 * From the 4.4BSD PRM:
1141 		 * "The data argument is taken as a signal number and the
1142 		 * child's execution continues at location addr as if it
1143 		 * incurred that signal.  Normally the signal number will
1144 		 * be either 0 to indicate that the signal that caused the
1145 		 * stop should be ignored, or that value fetched out of
1146 		 * the process's image indicating which signal caused
1147 		 * the stop.  If addr is (int *)1 then execution continues
1148 		 * from where it stopped."
1149 		 */
1150 
1151 		/* Check that the data is a valid signal number or zero. */
1152 		if (signo < 0 || signo >= NSIG) {
1153 			error = EINVAL;
1154 			break;
1155 		}
1156 
1157 		/* Prevent process deadlock */
1158 		if (resume_all) {
1159 #ifdef PT_STEP
1160 			if (req == PT_STEP) {
1161 				if (lt->l_flag & LW_WSUSPEND) {
1162 					error = EDEADLK;
1163 					break;
1164 				}
1165 			} else
1166 #endif
1167 			{
1168 				error = EDEADLK;
1169 				LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1170 					if ((lt2->l_flag & LW_WSUSPEND) == 0) {
1171 						error = 0;
1172 						break;
1173 					}
1174 				}
1175 				if (error != 0)
1176 					break;
1177 			}
1178 		} else {
1179 			if (lt->l_flag & LW_WSUSPEND) {
1180 				error = EDEADLK;
1181 				break;
1182 			}
1183 		}
1184 
1185 		/* If the address parameter is not (int *)1, set the pc. */
1186 		if ((int *)addr != (int *)1) {
1187 			error = process_set_pc(lt, addr);
1188 			if (error != 0)
1189 				break;
1190 		}
1191 #ifdef PT_STEP
1192 		/*
1193 		 * Arrange for a single-step, if that's requested and possible.
1194 		 * More precisely, set the single step status as requested for
1195 		 * the requested thread, and clear it for other threads.
1196 		 */
1197 		LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1198 			if (ISSET(lt2->l_pflag, LP_SINGLESTEP)) {
1199 				lwp_lock(lt2);
1200 				process_sstep(lt2, 1);
1201 				lwp_unlock(lt2);
1202 			} else if (lt != lt2) {
1203 				lwp_lock(lt2);
1204 				process_sstep(lt2, 0);
1205 				lwp_unlock(lt2);
1206 			}
1207 		}
1208 		error = process_sstep(lt,
1209 		    ISSET(lt->l_pflag, LP_SINGLESTEP) || req == PT_STEP);
1210 		if (error)
1211 			break;
1212 #endif
1213 		if (req == PT_DETACH) {
1214 			CLR(t->p_slflag, PSL_TRACED|PSL_SYSCALL);
1215 
1216 			/* give process back to original parent or init */
1217 			if (t->p_opptr != t->p_pptr) {
1218 				struct proc *pp = t->p_opptr;
1219 				proc_reparent(t, pp ? pp : initproc);
1220 			}
1221 
1222 			/* not being traced any more */
1223 			t->p_opptr = NULL;
1224 
1225 			/* clear single step */
1226 			LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1227 				CLR(lt2->l_pflag, LP_SINGLESTEP);
1228 			}
1229 			CLR(lt->l_pflag, LP_SINGLESTEP);
1230 		}
1231 	sendsig:
1232 		error = ptrace_sendsig(t, lt, signo, resume_all);
1233 		break;
1234 
1235 	case PT_SYSCALLEMU:
1236 		if (!ISSET(t->p_slflag, PSL_SYSCALL) || t->p_stat != SSTOP) {
1237 			error = EINVAL;
1238 			break;
1239 		}
1240 		SET(t->p_slflag, PSL_SYSCALLEMU);
1241 		break;
1242 
1243 #ifdef PT_STEP
1244 	case PT_SETSTEP:
1245 		write = 1;
1246 
1247 	case PT_CLEARSTEP:
1248 		/* write = 0 done above. */
1249 		if ((error = ptrace_update_lwp(t, &lt, data)) != 0)
1250 			break;
1251 
1252 		if (write)
1253 			SET(lt->l_pflag, LP_SINGLESTEP);
1254 		else
1255 			CLR(lt->l_pflag, LP_SINGLESTEP);
1256 		break;
1257 #endif
1258 
1259 	case PT_KILL:
1260 		/* just send the process a KILL signal. */
1261 		signo = SIGKILL;
1262 		goto sendsig;	/* in PT_CONTINUE, above. */
1263 
1264 	case PT_ATTACH:
1265 		/*
1266 		 * Go ahead and set the trace flag.
1267 		 * Save the old parent (it's reset in
1268 		 *   _DETACH, and also in kern_exit.c:wait4()
1269 		 * Reparent the process so that the tracing
1270 		 *   proc gets to see all the action.
1271 		 * Stop the target.
1272 		 */
1273 		proc_changeparent(t, p);
1274 		signo = SIGSTOP;
1275 		goto sendsig;
1276 
1277 	case PT_GET_EVENT_MASK:
1278 		error = ptrace_get_event_mask(t, addr, data);
1279 		break;
1280 
1281 	case PT_SET_EVENT_MASK:
1282 		error = ptrace_set_event_mask(t, addr, data);
1283 		break;
1284 
1285 	case PT_GET_PROCESS_STATE:
1286 		error = ptrace_get_process_state(t, addr, data);
1287 		break;
1288 
1289 	case PT_LWPINFO:
1290 		error = ptrace_lwpinfo(t, &lt, addr, data);
1291 		break;
1292 
1293 	case PT_SET_SIGINFO:
1294 		error = ptrace_set_siginfo(t, &lt, ptm, addr, data);
1295 		break;
1296 
1297 	case PT_GET_SIGINFO:
1298 		error = ptrace_get_siginfo(t, ptm, addr, data);
1299 		break;
1300 
1301 	case PT_RESUME:
1302 	case PT_SUSPEND:
1303 		error = ptrace_startstop(t, &lt, req, addr, data);
1304 		break;
1305 
1306 #ifdef PT_REGISTERS
1307 	case_PT_SETREGS
1308 	case_PT_GETREGS
1309 	case_PT_SETFPREGS
1310 	case_PT_GETFPREGS
1311 	case_PT_SETDBREGS
1312 	case_PT_GETDBREGS
1313 		error = ptrace_regs(l, &lt, req, ptm, addr, data);
1314 		break;
1315 #endif
1316 
1317 #ifdef __HAVE_PTRACE_MACHDEP
1318 	PTRACE_MACHDEP_REQUEST_CASES
1319 		error = ptrace_machdep_dorequest(l, lt, req, addr, data);
1320 		break;
1321 #endif
1322 	}
1323 
1324 out:
1325 	if (pheld) {
1326 		mutex_exit(t->p_lock);
1327 		mutex_exit(proc_lock);
1328 	}
1329 	if (lt != NULL)
1330 		lwp_delref(lt);
1331 	rw_exit(&t->p_reflock);
1332 
1333 	return error;
1334 }
1335 
1336 typedef int (*regrfunc_t)(struct lwp *, void *, size_t *);
1337 typedef int (*regwfunc_t)(struct lwp *, void *, size_t);
1338 
1339 #ifdef PT_REGISTERS
1340 static int
1341 proc_regio(struct lwp *l, struct uio *uio, size_t ks, regrfunc_t r,
1342     regwfunc_t w)
1343 {
1344 	char buf[1024];
1345 	int error;
1346 	char *kv;
1347 	size_t kl;
1348 
1349 	if (ks > sizeof(buf))
1350 		return E2BIG;
1351 
1352 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)ks)
1353 		return EINVAL;
1354 
1355 	kv = buf + uio->uio_offset;
1356 	kl = ks - uio->uio_offset;
1357 
1358 	if (kl > uio->uio_resid)
1359 		kl = uio->uio_resid;
1360 
1361 	error = (*r)(l, buf, &ks);
1362 	if (error == 0)
1363 		error = uiomove(kv, kl, uio);
1364 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1365 		if (l->l_stat != LSSTOP)
1366 			error = EBUSY;
1367 		else
1368 			error = (*w)(l, buf, ks);
1369 	}
1370 
1371 	uio->uio_offset = 0;
1372 	return error;
1373 }
1374 #endif
1375 
1376 int
1377 process_doregs(struct lwp *curl /*tracer*/,
1378     struct lwp *l /*traced*/,
1379     struct uio *uio)
1380 {
1381 #if defined(PT_GETREGS) || defined(PT_SETREGS)
1382 	size_t s;
1383 	regrfunc_t r;
1384 	regwfunc_t w;
1385 
1386 #ifdef COMPAT_NETBSD32
1387 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1388 
1389 	if (__predict_false(pk32)) {
1390 		s = sizeof(process_reg32);
1391 		r = (regrfunc_t)process_read_regs32;
1392 		w = (regwfunc_t)process_write_regs32;
1393 	} else
1394 #endif
1395 	{
1396 		s = sizeof(struct reg);
1397 		r = (regrfunc_t)process_read_regs;
1398 		w = (regwfunc_t)process_write_regs;
1399 	}
1400 	return proc_regio(l, uio, s, r, w);
1401 #else
1402 	return EINVAL;
1403 #endif
1404 }
1405 
1406 int
1407 process_validregs(struct lwp *l)
1408 {
1409 
1410 #if defined(PT_SETREGS) || defined(PT_GETREGS)
1411 	return (l->l_flag & LW_SYSTEM) == 0;
1412 #else
1413 	return 0;
1414 #endif
1415 }
1416 
1417 int
1418 process_dofpregs(struct lwp *curl /*tracer*/,
1419     struct lwp *l /*traced*/,
1420     struct uio *uio)
1421 {
1422 #if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
1423 	size_t s;
1424 	regrfunc_t r;
1425 	regwfunc_t w;
1426 
1427 #ifdef COMPAT_NETBSD32
1428 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1429 
1430 	if (__predict_false(pk32)) {
1431 		s = sizeof(process_fpreg32);
1432 		r = (regrfunc_t)process_read_fpregs32;
1433 		w = (regwfunc_t)process_write_fpregs32;
1434 	} else
1435 #endif
1436 	{
1437 		s = sizeof(struct fpreg);
1438 		r = (regrfunc_t)process_read_fpregs;
1439 		w = (regwfunc_t)process_write_fpregs;
1440 	}
1441 	return proc_regio(l, uio, s, r, w);
1442 #else
1443 	return EINVAL;
1444 #endif
1445 }
1446 
1447 int
1448 process_validfpregs(struct lwp *l)
1449 {
1450 
1451 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
1452 	return (l->l_flag & LW_SYSTEM) == 0;
1453 #else
1454 	return 0;
1455 #endif
1456 }
1457 
1458 int
1459 process_dodbregs(struct lwp *curl /*tracer*/,
1460     struct lwp *l /*traced*/,
1461     struct uio *uio)
1462 {
1463 #if defined(PT_GETDBREGS) || defined(PT_SETDBREGS)
1464 	size_t s;
1465 	regrfunc_t r;
1466 	regwfunc_t w;
1467 
1468 #ifdef COMPAT_NETBSD32
1469 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1470 
1471 	if (__predict_false(pk32)) {
1472 		s = sizeof(process_dbreg32);
1473 		r = (regrfunc_t)process_read_dbregs32;
1474 		w = (regwfunc_t)process_write_dbregs32;
1475 	} else
1476 #endif
1477 	{
1478 		s = sizeof(struct dbreg);
1479 		r = (regrfunc_t)process_read_dbregs;
1480 		w = (regwfunc_t)process_write_dbregs;
1481 	}
1482 	return proc_regio(l, uio, s, r, w);
1483 #else
1484 	return EINVAL;
1485 #endif
1486 }
1487 
1488 int
1489 process_validdbregs(struct lwp *l)
1490 {
1491 
1492 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
1493 	return (l->l_flag & LW_SYSTEM) == 0;
1494 #else
1495 	return 0;
1496 #endif
1497 }
1498 
1499 static int
1500 process_auxv_offset(struct proc *p, struct uio *uio)
1501 {
1502 	struct ps_strings pss;
1503 	int error;
1504 	off_t off = (off_t)p->p_psstrp;
1505 
1506 	if ((error = copyin_psstrings(p, &pss)) != 0)
1507 		return error;
1508 
1509 	if (pss.ps_envstr == NULL)
1510 		return EIO;
1511 
1512 	uio->uio_offset += (off_t)(vaddr_t)(pss.ps_envstr + pss.ps_nenvstr + 1);
1513 #ifdef __MACHINE_STACK_GROWS_UP
1514 	if (uio->uio_offset < off)
1515 		return EIO;
1516 #else
1517 	if (uio->uio_offset > off)
1518 		return EIO;
1519 	if ((uio->uio_offset + uio->uio_resid) > off)
1520 		uio->uio_resid = off - uio->uio_offset;
1521 #endif
1522 	return 0;
1523 }
1524 #endif /* PTRACE */
1525 
1526 MODULE(MODULE_CLASS_EXEC, ptrace_common, "");
1527 
1528 static int
1529 ptrace_common_modcmd(modcmd_t cmd, void *arg)
1530 {
1531         int error;
1532 
1533         switch (cmd) {
1534         case MODULE_CMD_INIT:
1535                 error = ptrace_init();
1536                 break;
1537         case MODULE_CMD_FINI:
1538                 error = ptrace_fini();
1539                 break;
1540         default:
1541 		ptrace_hooks();
1542                 error = ENOTTY;
1543                 break;
1544         }
1545         return error;
1546 }
1547