xref: /netbsd-src/sys/kern/sys_ptrace_common.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: sys_ptrace_common.c,v 1.45 2018/06/23 03:32:48 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 1.45 2018/06/23 03:32:48 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 # ifdef PTRACE_DEBUG
158 #  define DPRINTF(a) uprintf a
159 # else
160 #  define DPRINTF(a)
161 # endif
162 
163 static kauth_listener_t ptrace_listener;
164 static int process_auxv_offset(struct proc *, struct uio *);
165 
166 #if 0
167 static int ptrace_cbref;
168 static kmutex_t ptrace_mtx;
169 static kcondvar_t ptrace_cv;
170 #endif
171 
172 #ifdef PT_GETREGS
173 # define case_PT_GETREGS	case PT_GETREGS:
174 #else
175 # define case_PT_GETREGS
176 #endif
177 
178 #ifdef PT_SETREGS
179 # define case_PT_SETREGS	case PT_SETREGS:
180 #else
181 # define case_PT_SETREGS
182 #endif
183 
184 #ifdef PT_GETFPREGS
185 # define case_PT_GETFPREGS	case PT_GETFPREGS:
186 #else
187 # define case_PT_GETFPREGS
188 #endif
189 
190 #ifdef PT_SETFPREGS
191 # define case_PT_SETFPREGS	case PT_SETFPREGS:
192 #else
193 # define case_PT_SETFPREGS
194 #endif
195 
196 #ifdef PT_GETDBREGS
197 # define case_PT_GETDBREGS	case PT_GETDBREGS:
198 #else
199 # define case_PT_GETDBREGS
200 #endif
201 
202 #ifdef PT_SETDBREGS
203 # define case_PT_SETDBREGS	case PT_SETDBREGS:
204 #else
205 # define case_PT_SETDBREGS
206 #endif
207 
208 #if defined(PT_SETREGS) || defined(PT_GETREGS) || \
209     defined(PT_SETFPREGS) || defined(PT_GETFOREGS) || \
210     defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
211 # define PT_REGISTERS
212 #endif
213 
214 static int
215 ptrace_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
216     void *arg0, void *arg1, void *arg2, void *arg3)
217 {
218 	struct proc *p;
219 	int result;
220 #ifdef PT_SETDBREGS
221 	extern int user_set_dbregs;
222 #endif
223 
224 	result = KAUTH_RESULT_DEFER;
225 	p = arg0;
226 
227 #if 0
228 	mutex_enter(&ptrace_mtx);
229 	ptrace_cbref++;
230 	mutex_exit(&ptrace_mtx);
231 #endif
232 	if (action != KAUTH_PROCESS_PTRACE)
233 		goto out;
234 
235 	switch ((u_long)arg1) {
236 #ifdef PT_SETDBREGS
237 	case_PT_SETDBREGS
238 		if (kauth_cred_getuid(cred) != 0 && user_set_dbregs == 0) {
239 			result = KAUTH_RESULT_DENY;
240 			break;
241 		}
242 #endif
243 	case PT_TRACE_ME:
244 	case PT_ATTACH:
245 	case PT_WRITE_I:
246 	case PT_WRITE_D:
247 	case PT_READ_I:
248 	case PT_READ_D:
249 	case PT_IO:
250 	case_PT_GETREGS
251 	case_PT_SETREGS
252 	case_PT_GETFPREGS
253 	case_PT_SETFPREGS
254 	case_PT_GETDBREGS
255 	case PT_SET_EVENT_MASK:
256 	case PT_GET_EVENT_MASK:
257 	case PT_GET_PROCESS_STATE:
258 	case PT_SET_SIGINFO:
259 	case PT_GET_SIGINFO:
260 #ifdef __HAVE_PTRACE_MACHDEP
261 	PTRACE_MACHDEP_REQUEST_CASES
262 #endif
263 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
264 		    ISSET(p->p_flag, PK_SUGID)) {
265 			break;
266 		}
267 
268 		result = KAUTH_RESULT_ALLOW;
269 
270 	break;
271 
272 #ifdef PT_STEP
273 	case PT_STEP:
274 	case PT_SETSTEP:
275 	case PT_CLEARSTEP:
276 #endif
277 	case PT_CONTINUE:
278 	case PT_KILL:
279 	case PT_DETACH:
280 	case PT_LWPINFO:
281 	case PT_SYSCALL:
282 	case PT_SYSCALLEMU:
283 	case PT_DUMPCORE:
284 	case PT_RESUME:
285 	case PT_SUSPEND:
286 		result = KAUTH_RESULT_ALLOW;
287 		break;
288 
289 	default:
290 		break;
291 	}
292 
293  out:
294 #if 0
295 	mutex_enter(&ptrace_mtx);
296 	if (--ptrace_cbref == 0)
297 		cv_broadcast(&ptrace_cv);
298 	mutex_exit(&ptrace_mtx);
299 #endif
300 
301 	return result;
302 }
303 
304 int
305 ptrace_init(void)
306 {
307 
308 #if 0
309 	mutex_init(&ptrace_mtx, MUTEX_DEFAULT, IPL_NONE);
310 	cv_init(&ptrace_cv, "ptracecb");
311 	ptrace_cbref = 0;
312 #endif
313 	ptrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
314 	    ptrace_listener_cb, NULL);
315 	return 0;
316 }
317 
318 int
319 ptrace_fini(void)
320 {
321 
322 	kauth_unlisten_scope(ptrace_listener);
323 
324 #if 0
325 	/* Make sure no-one is executing our kauth listener */
326 
327 	mutex_enter(&ptrace_mtx);
328 	while (ptrace_cbref != 0)
329 		cv_wait(&ptrace_cv, &ptrace_mtx);
330 	mutex_exit(&ptrace_mtx);
331 	mutex_destroy(&ptrace_mtx);
332 	cv_destroy(&ptrace_cv);
333 #endif
334 
335 	return 0;
336 }
337 
338 static struct proc *
339 ptrace_find(struct lwp *l, int req, pid_t pid)
340 {
341 	struct proc *t;
342 
343 	/* "A foolish consistency..." XXX */
344 	if (req == PT_TRACE_ME) {
345 		t = l->l_proc;
346 		mutex_enter(t->p_lock);
347 		return t;
348 	}
349 
350 	/* Find the process we're supposed to be operating on. */
351 	t = proc_find(pid);
352 	if (t == NULL)
353 		return NULL;
354 
355 	/* XXX-elad */
356 	mutex_enter(t->p_lock);
357 	int error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
358 	    t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
359 	if (error) {
360 		mutex_exit(t->p_lock);
361 		return NULL;
362 	}
363 	return t;
364 }
365 
366 static int
367 ptrace_allowed(struct lwp *l, int req, struct proc *t, struct proc *p)
368 {
369 	/*
370 	 * Grab a reference on the process to prevent it from execing or
371 	 * exiting.
372 	 */
373 	if (!rw_tryenter(&t->p_reflock, RW_READER))
374 		return EBUSY;
375 
376 	/* Make sure we can operate on it. */
377 	switch (req) {
378 	case PT_TRACE_ME:
379 		/*
380 		 * You can't say to the parent of a process to start tracing if:
381 		 *	(1) the parent is initproc,
382 		 */
383 		if (p->p_pptr == initproc)
384 			return EPERM;
385 
386 		/*
387 		 *	(2) the process is initproc, or
388 		 */
389 		if (p == initproc)
390 			return EPERM;
391 
392 		/*
393 		 *	(3) the child is already traced.
394 		 */
395 		if (ISSET(p->p_slflag, PSL_TRACED))
396 			return EBUSY;
397 
398 		return 0;
399 
400 	case PT_ATTACH:
401 		/*
402 		 * You can't attach to a process if:
403 		 *	(1) it's the process that's doing the attaching,
404 		 */
405 		if (t == p)
406 			return EINVAL;
407 
408 		/*
409 		 *	(2) it's a system process,
410 		 */
411 		if (t->p_flag & PK_SYSTEM)
412 			return EPERM;
413 
414 		/*
415 		 *	(3) the tracer is initproc,
416 		 */
417 		if (p == initproc)
418 			return EPERM;
419 
420 		/*
421 		 *	(4) it's already being traced,
422 		 */
423 		if (ISSET(t->p_slflag, PSL_TRACED))
424 			return EBUSY;
425 
426 		/*
427 		 *	(5) it's a vfork(2)ed parent of the current process, or
428 		 */
429 		if (ISSET(p->p_lflag, PL_PPWAIT) && p->p_pptr == t)
430 			return EPERM;
431 
432 		/*
433 		 * 	(6) the tracer is chrooted, and its root directory is
434 		 * 	    not at or above the root directory of the tracee
435 		 */
436 		mutex_exit(t->p_lock);	/* XXXSMP */
437 		int tmp = proc_isunder(t, l);
438 		mutex_enter(t->p_lock);	/* XXXSMP */
439 		if (!tmp)
440 			return EPERM;
441 		return 0;
442 
443 	case PT_READ_I:
444 	case PT_READ_D:
445 	case PT_WRITE_I:
446 	case PT_WRITE_D:
447 	case PT_IO:
448 	case PT_SET_SIGINFO:
449 	case PT_GET_SIGINFO:
450 	case_PT_GETREGS
451 	case_PT_SETREGS
452 	case_PT_GETFPREGS
453 	case_PT_SETFPREGS
454 	case_PT_GETDBREGS
455 	case_PT_SETDBREGS
456 #ifdef __HAVE_PTRACE_MACHDEP
457 	PTRACE_MACHDEP_REQUEST_CASES
458 #endif
459 		/*
460 		 * You can't read/write the memory or registers of a process
461 		 * if the tracer is chrooted, and its root directory is not at
462 		 * or above the root directory of the tracee.
463 		 */
464 		mutex_exit(t->p_lock);	/* XXXSMP */
465 		tmp = proc_isunder(t, l);
466 		mutex_enter(t->p_lock);	/* XXXSMP */
467 		if (!tmp)
468 			return EPERM;
469 		/*FALLTHROUGH*/
470 
471 	case PT_CONTINUE:
472 	case PT_KILL:
473 	case PT_DETACH:
474 	case PT_LWPINFO:
475 	case PT_SYSCALL:
476 	case PT_SYSCALLEMU:
477 	case PT_DUMPCORE:
478 #ifdef PT_STEP
479 	case PT_STEP:
480 	case PT_SETSTEP:
481 	case PT_CLEARSTEP:
482 #endif
483 	case PT_SET_EVENT_MASK:
484 	case PT_GET_EVENT_MASK:
485 	case PT_GET_PROCESS_STATE:
486 	case PT_RESUME:
487 	case PT_SUSPEND:
488 		/*
489 		 * You can't do what you want to the process if:
490 		 *	(1) It's not being traced at all,
491 		 */
492 		if (!ISSET(t->p_slflag, PSL_TRACED))
493 			return EPERM;
494 
495 		/*
496 		 *	(2) it's not being traced by _you_, or
497 		 */
498 		if (t->p_pptr != p) {
499 			DPRINTF(("parent %d != %d\n", t->p_pptr->p_pid,
500 			    p->p_pid));
501 			return EBUSY;
502 		}
503 
504 		/*
505 		 *	(3) it's not currently stopped.
506 		 */
507 		if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) {
508 			DPRINTF(("stat %d flag %d\n", t->p_stat,
509 			    !t->p_waited));
510 			return EBUSY;
511 		}
512 		return 0;
513 
514 	default:			/* It was not a legal request. */
515 		return EINVAL;
516 	}
517 }
518 
519 static int
520 ptrace_needs_hold(int req)
521 {
522 	switch (req) {
523 #ifdef PT_STEP
524 	case PT_STEP:
525 #endif
526 	case PT_CONTINUE:
527 	case PT_DETACH:
528 	case PT_KILL:
529 	case PT_SYSCALL:
530 	case PT_SYSCALLEMU:
531 	case PT_ATTACH:
532 	case PT_TRACE_ME:
533 	case PT_GET_SIGINFO:
534 	case PT_SET_SIGINFO:
535 		return 1;
536 	default:
537 		return 0;
538 	}
539 }
540 
541 static int
542 ptrace_update_lwp(struct proc *t, struct lwp **lt, lwpid_t lid)
543 {
544 	if (lid == 0 || lid == (*lt)->l_lid || t->p_nlwps == 1)
545 		return 0;
546 
547 	lwp_delref(*lt);
548 
549 	mutex_enter(t->p_lock);
550 	*lt = lwp_find(t, lid);
551 	if (*lt == NULL) {
552 		mutex_exit(t->p_lock);
553 		return ESRCH;
554 	}
555 
556 	if ((*lt)->l_flag & LW_SYSTEM) {
557 		*lt = NULL;
558 		return EINVAL;
559 	}
560 
561 	lwp_addref(*lt);
562 	mutex_exit(t->p_lock);
563 
564 	return 0;
565 }
566 
567 static int
568 ptrace_get_siginfo(struct proc *t, struct ptrace_methods *ptm, void *addr,
569     size_t data)
570 {
571 	struct ptrace_siginfo psi;
572 
573 	psi.psi_siginfo._info = t->p_sigctx.ps_info;
574 	psi.psi_lwpid = t->p_sigctx.ps_lwp;
575 	DPRINTF(("%s: lwp=%d signal=%d\n", __func__, psi.psi_lwpid,
576 	    psi.psi_siginfo.si_signo));
577 
578 	return ptm->ptm_copyout_siginfo(&psi, addr, data);
579 }
580 
581 static int
582 ptrace_set_siginfo(struct proc *t, struct lwp **lt, struct ptrace_methods *ptm,
583     void *addr, size_t data)
584 {
585 	struct ptrace_siginfo psi;
586 
587 	int error = ptm->ptm_copyin_siginfo(&psi, addr, data);
588 	if (error)
589 		return error;
590 
591 	/* Check that the data is a valid signal number or zero. */
592 	if (psi.psi_siginfo.si_signo < 0 || psi.psi_siginfo.si_signo >= NSIG)
593 		return EINVAL;
594 
595 	if ((error = ptrace_update_lwp(t, lt, psi.psi_lwpid)) != 0)
596 		return error;
597 
598 	t->p_sigctx.ps_faked = true;
599 	t->p_sigctx.ps_info = psi.psi_siginfo._info;
600 	t->p_sigctx.ps_lwp = psi.psi_lwpid;
601 	DPRINTF(("%s: lwp=%d signal=%d\n", __func__, psi.psi_lwpid,
602 	    psi.psi_siginfo.si_signo));
603 	return 0;
604 }
605 
606 static int
607 ptrace_get_event_mask(struct proc *t, void *addr, size_t data)
608 {
609 	struct ptrace_event pe;
610 
611 	if (data != sizeof(pe)) {
612 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
613 		return EINVAL;
614 	}
615 	memset(&pe, 0, sizeof(pe));
616 	pe.pe_set_event = ISSET(t->p_slflag, PSL_TRACEFORK) ?
617 	    PTRACE_FORK : 0;
618 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK) ?
619 	    PTRACE_VFORK : 0;
620 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK_DONE) ?
621 	    PTRACE_VFORK_DONE : 0;
622 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_CREATE) ?
623 	    PTRACE_LWP_CREATE : 0;
624 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_EXIT) ?
625 	    PTRACE_LWP_EXIT : 0;
626 	DPRINTF(("%s: lwp=%d event=%#x\n", __func__,
627 	    t->p_sigctx.ps_lwp, pe.pe_set_event));
628 	return copyout(&pe, addr, sizeof(pe));
629 }
630 
631 static int
632 ptrace_set_event_mask(struct proc *t, void *addr, size_t data)
633 {
634 	struct ptrace_event pe;
635 	int error;
636 
637 	if (data != sizeof(pe)) {
638 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
639 		return EINVAL;
640 	}
641 	if ((error = copyin(addr, &pe, sizeof(pe))) != 0)
642 		return error;
643 
644 	DPRINTF(("%s: lwp=%d event=%#x\n", __func__,
645 	    t->p_sigctx.ps_lwp, pe.pe_set_event));
646 	if (pe.pe_set_event & PTRACE_FORK)
647 		SET(t->p_slflag, PSL_TRACEFORK);
648 	else
649 		CLR(t->p_slflag, PSL_TRACEFORK);
650 
651 	if (pe.pe_set_event & PTRACE_VFORK)
652 		SET(t->p_slflag, PSL_TRACEVFORK);
653 	else
654 		CLR(t->p_slflag, PSL_TRACEVFORK);
655 
656 	if (pe.pe_set_event & PTRACE_VFORK_DONE)
657 		SET(t->p_slflag, PSL_TRACEVFORK_DONE);
658 	else
659 		CLR(t->p_slflag, PSL_TRACEVFORK_DONE);
660 
661 	if (pe.pe_set_event & PTRACE_LWP_CREATE)
662 		SET(t->p_slflag, PSL_TRACELWP_CREATE);
663 	else
664 		CLR(t->p_slflag, PSL_TRACELWP_CREATE);
665 
666 	if (pe.pe_set_event & PTRACE_LWP_EXIT)
667 		SET(t->p_slflag, PSL_TRACELWP_EXIT);
668 	else
669 		CLR(t->p_slflag, PSL_TRACELWP_EXIT);
670 	return 0;
671 }
672 
673 static int
674 ptrace_get_process_state(struct proc *t, void *addr, size_t data)
675 {
676 	struct ptrace_state ps;
677 
678 	if (data != sizeof(ps)) {
679 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(ps)));
680 		return EINVAL;
681 	}
682 	memset(&ps, 0, sizeof(ps));
683 
684 	if (t->p_fpid) {
685 		ps.pe_report_event = PTRACE_FORK;
686 		ps.pe_other_pid = t->p_fpid;
687 	} else if (t->p_vfpid) {
688 		ps.pe_report_event = PTRACE_VFORK;
689 		ps.pe_other_pid = t->p_vfpid;
690 	} else if (t->p_vfpid_done) {
691 		ps.pe_report_event = PTRACE_VFORK_DONE;
692 		ps.pe_other_pid = t->p_vfpid_done;
693 	} else if (t->p_lwp_created) {
694 		ps.pe_report_event = PTRACE_LWP_CREATE;
695 		ps.pe_lwp = t->p_lwp_created;
696 	} else if (t->p_lwp_exited) {
697 		ps.pe_report_event = PTRACE_LWP_EXIT;
698 		ps.pe_lwp = t->p_lwp_exited;
699 	}
700 	DPRINTF(("%s: lwp=%d event=%#x pid=%d lwp=%d\n", __func__,
701 	    t->p_sigctx.ps_lwp, ps.pe_report_event,
702 	    ps.pe_other_pid, ps.pe_lwp));
703 	return copyout(&ps, addr, sizeof(ps));
704 }
705 
706 static int
707 ptrace_lwpinfo(struct proc *t, struct lwp **lt, void *addr, size_t data)
708 {
709 	struct ptrace_lwpinfo pl;
710 
711 	if (data != sizeof(pl)) {
712 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pl)));
713 		return EINVAL;
714 	}
715 	int error = copyin(addr, &pl, sizeof(pl));
716 	if (error)
717 		return error;
718 
719 	lwpid_t tmp = pl.pl_lwpid;
720 	lwp_delref(*lt);
721 	mutex_enter(t->p_lock);
722 	if (tmp == 0)
723 		*lt = lwp_find_first(t);
724 	else {
725 		*lt = lwp_find(t, tmp);
726 		if (*lt == NULL) {
727 			mutex_exit(t->p_lock);
728 			return ESRCH;
729 		}
730 		*lt = LIST_NEXT(*lt, l_sibling);
731 	}
732 
733 	while (*lt != NULL && !lwp_alive(*lt))
734 		*lt = LIST_NEXT(*lt, l_sibling);
735 
736 	pl.pl_lwpid = 0;
737 	pl.pl_event = 0;
738 	if (*lt) {
739 		lwp_addref(*lt);
740 		pl.pl_lwpid = (*lt)->l_lid;
741 
742 		if ((*lt)->l_flag & LW_WSUSPEND)
743 			pl.pl_event = PL_EVENT_SUSPENDED;
744 		/*
745 		 * If we match the lwp, or it was sent to every lwp,
746 		 * we set PL_EVENT_SIGNAL.
747 		 * XXX: ps_lwp == 0 means everyone and noone, so
748 		 * check ps_signo too.
749 		 */
750 		else if ((*lt)->l_lid == t->p_sigctx.ps_lwp
751 			 || (t->p_sigctx.ps_lwp == 0 &&
752 			     t->p_sigctx.ps_info._signo)) {
753 			DPRINTF(("%s: lwp=%d siglwp=%d signo %d\n", __func__,
754 			    pl.pl_lwpid, t->p_sigctx.ps_lwp,
755 			    t->p_sigctx.ps_info._signo));
756 			pl.pl_event = PL_EVENT_SIGNAL;
757 		}
758 	}
759 	mutex_exit(t->p_lock);
760 	DPRINTF(("%s: lwp=%d event=%#x\n", __func__,
761 	    pl.pl_lwpid, pl.pl_event));
762 
763 	return copyout(&pl, addr, sizeof(pl));
764 }
765 
766 static int
767 ptrace_startstop(struct proc *t, struct lwp **lt, int rq, void *addr,
768     size_t data)
769 {
770 	int error;
771 
772 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
773 		return error;
774 
775 	DPRINTF(("%s: lwp=%d request=%d\n", __func__, (*lt)->l_lid, rq));
776 	lwp_lock(*lt);
777 	if (rq == PT_SUSPEND)
778 		(*lt)->l_flag |= LW_WSUSPEND;
779 	else
780 		(*lt)->l_flag &= ~LW_WSUSPEND;
781 	lwp_unlock(*lt);
782 	return 0;
783 }
784 
785 #ifdef PT_REGISTERS
786 static int
787 ptrace_uio_dir(int req)
788 {
789 	switch (req) {
790 	case_PT_GETREGS
791 	case_PT_GETFPREGS
792 	case_PT_GETDBREGS
793 		return UIO_READ;
794 	case_PT_SETREGS
795 	case_PT_SETFPREGS
796 	case_PT_SETDBREGS
797 		return UIO_WRITE;
798 	default:
799 		return -1;
800 	}
801 }
802 
803 static int
804 ptrace_regs(struct lwp *l, struct lwp **lt, int rq, struct ptrace_methods *ptm,
805     void *addr, size_t data)
806 {
807 	int error;
808 	struct proc *t = (*lt)->l_proc;
809 	struct vmspace *vm;
810 
811 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
812 		return error;
813 
814 	int dir = ptrace_uio_dir(rq);
815 	size_t size;
816 	int (*func)(struct lwp *, struct lwp *, struct uio *);
817 
818 	DPRINTF(("%s: lwp=%d request=%d\n", __func__, l->l_lid, rq));
819 
820 	switch (rq) {
821 #if defined(PT_SETREGS) || defined(PT_GETREGS)
822 	case_PT_GETREGS
823 	case_PT_SETREGS
824 		if (!process_validregs(*lt))
825 			return EINVAL;
826 		size = PROC_REGSZ(t);
827 		func = ptm->ptm_doregs;
828 		break;
829 #endif
830 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
831 	case_PT_GETFPREGS
832 	case_PT_SETFPREGS
833 		if (!process_validfpregs(*lt))
834 			return EINVAL;
835 		size = PROC_FPREGSZ(t);
836 		func = ptm->ptm_dofpregs;
837 		break;
838 #endif
839 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
840 	case_PT_GETDBREGS
841 	case_PT_SETDBREGS
842 		if (!process_validdbregs(*lt))
843 			return EINVAL;
844 		size = PROC_DBREGSZ(t);
845 		func = ptm->ptm_dodbregs;
846 		break;
847 #endif
848 	default:
849 		return EINVAL;
850 	}
851 
852 	error = proc_vmspace_getref(l->l_proc, &vm);
853 	if (error)
854 		return error;
855 
856 	struct uio uio;
857 	struct iovec iov;
858 
859 	iov.iov_base = addr;
860 	iov.iov_len = size;
861 	uio.uio_iov = &iov;
862 	uio.uio_iovcnt = 1;
863 	uio.uio_offset = 0;
864 	uio.uio_resid = iov.iov_len;
865 	uio.uio_rw = dir;
866 	uio.uio_vmspace = vm;
867 
868 	error = (*func)(l, *lt, &uio);
869 	uvmspace_free(vm);
870 	return error;
871 }
872 #endif
873 
874 static int
875 ptrace_sendsig(struct proc *t, struct lwp *lt, int signo, int resume_all)
876 {
877 	ksiginfo_t ksi;
878 
879 	t->p_fpid = 0;
880 	t->p_vfpid = 0;
881 	t->p_vfpid_done = 0;
882 	t->p_lwp_created = 0;
883 	t->p_lwp_exited = 0;
884 
885 	/* Finally, deliver the requested signal (or none). */
886 	if (t->p_stat == SSTOP) {
887 		/*
888 		 * Unstop the process.  If it needs to take a
889 		 * signal, make all efforts to ensure that at
890 		 * an LWP runs to see it.
891 		 */
892 		t->p_xsig = signo;
893 
894 		/*
895 		 * signo > 0 check prevents a potential panic, as
896 		 * sigismember(&...,0) is invalid check and signo
897 		 * can be equal to 0 as a special case of no-signal.
898 		 */
899 		if (signo > 0 && sigismember(&stopsigmask, signo)) {
900 			t->p_waited = 0;
901 			child_psignal(t, 0);
902 		} else if (resume_all)
903 			proc_unstop(t);
904 		else
905 			lwp_unstop(lt);
906 		return 0;
907 	}
908 
909 	KSI_INIT_EMPTY(&ksi);
910 	if (t->p_sigctx.ps_faked) {
911 		if (signo != t->p_sigctx.ps_info._signo)
912 			return EINVAL;
913 		t->p_sigctx.ps_faked = false;
914 		ksi.ksi_info = t->p_sigctx.ps_info;
915 		ksi.ksi_lid = t->p_sigctx.ps_lwp;
916 	} else if (signo == 0) {
917 		return 0;
918 	} else {
919 		ksi.ksi_signo = signo;
920 	}
921 	DPRINTF(("%s: pid=%d.%d signal=%d resume_all=%d\n", __func__, t->p_pid,
922 	    t->p_sigctx.ps_lwp, signo, resume_all));
923 
924 	kpsignal2(t, &ksi);
925 	return 0;
926 }
927 
928 static int
929 ptrace_dumpcore(struct lwp *lt, char *path, size_t len)
930 {
931 	int error;
932 	if (path != NULL) {
933 
934 		if (len >= MAXPATHLEN)
935 			return EINVAL;
936 
937 		char *src = path;
938 		path = kmem_alloc(len + 1, KM_SLEEP);
939 		error = copyin(src, path, len);
940 		if (error)
941 			goto out;
942 		path[len] = '\0';
943 	}
944 	DPRINTF(("%s: lwp=%d\n", __func__, lt->l_lid));
945 	error = (*coredump_vec)(lt, path);
946 out:
947 	if (path)
948 		kmem_free(path, len + 1);
949 	return error;
950 }
951 
952 static int
953 ptrace_doio(struct lwp *l, struct proc *t, struct lwp *lt,
954     struct ptrace_io_desc *piod, void *addr, bool sysspace)
955 {
956 	struct uio uio;
957 	struct iovec iov;
958 	int error, tmp;
959 
960 	error = 0;
961 	iov.iov_base = piod->piod_addr;
962 	iov.iov_len = piod->piod_len;
963 	uio.uio_iov = &iov;
964 	uio.uio_iovcnt = 1;
965 	uio.uio_offset = (off_t)(unsigned long)piod->piod_offs;
966 	uio.uio_resid = piod->piod_len;
967 
968 	DPRINTF(("%s: lwp=%d request=%d\n", __func__, l->l_lid, piod->piod_op));
969 
970 	switch (piod->piod_op) {
971 	case PIOD_READ_D:
972 	case PIOD_READ_I:
973 		uio.uio_rw = UIO_READ;
974 		break;
975 	case PIOD_WRITE_D:
976 	case PIOD_WRITE_I:
977 		/*
978 		 * Can't write to a RAS
979 		 */
980 		if (ras_lookup(t, addr) != (void *)-1) {
981 			return EACCES;
982 		}
983 		uio.uio_rw = UIO_WRITE;
984 		break;
985 	case PIOD_READ_AUXV:
986 		uio.uio_rw = UIO_READ;
987 		tmp = t->p_execsw->es_arglen;
988 		if (uio.uio_offset > tmp)
989 			return EIO;
990 		if (uio.uio_resid > tmp - uio.uio_offset)
991 			uio.uio_resid = tmp - uio.uio_offset;
992 		piod->piod_len = iov.iov_len = uio.uio_resid;
993 		error = process_auxv_offset(t, &uio);
994 		break;
995 	default:
996 		error = EINVAL;
997 		break;
998 	}
999 
1000 	if (error)
1001 		return error;
1002 
1003 	if (sysspace) {
1004 		uio.uio_vmspace = vmspace_kernel();
1005 	} else {
1006 		error = proc_vmspace_getref(l->l_proc, &uio.uio_vmspace);
1007 		if (error)
1008 			return error;
1009 	}
1010 
1011 	error = process_domem(l, lt, &uio);
1012 	if (!sysspace)
1013 		uvmspace_free(uio.uio_vmspace);
1014 	if (error)
1015 		return error;
1016 	piod->piod_len -= uio.uio_resid;
1017 	return 0;
1018 }
1019 
1020 int
1021 do_ptrace(struct ptrace_methods *ptm, struct lwp *l, int req, pid_t pid,
1022     void *addr, int data, register_t *retval)
1023 {
1024 	struct proc *p = l->l_proc;
1025 	struct lwp *lt = NULL;
1026 	struct lwp *lt2;
1027 	struct proc *t;				/* target process */
1028 	struct ptrace_io_desc piod;
1029 	int error, write, tmp, pheld;
1030 	int signo = 0;
1031 	int resume_all;
1032 	error = 0;
1033 
1034 	/*
1035 	 * If attaching or detaching, we need to get a write hold on the
1036 	 * proclist lock so that we can re-parent the target process.
1037 	 */
1038 	mutex_enter(proc_lock);
1039 
1040 	t = ptrace_find(l, req, pid);
1041 	if (t == NULL) {
1042 		mutex_exit(proc_lock);
1043 		return ESRCH;
1044 	}
1045 
1046 	pheld = 1;
1047 	if ((error = ptrace_allowed(l, req, t, p)) != 0)
1048 		goto out;
1049 
1050 	if ((error = kauth_authorize_process(l->l_cred,
1051 	    KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req), NULL, NULL)) != 0)
1052 		goto out;
1053 
1054 	if ((lt = lwp_find_first(t)) == NULL) {
1055 	    error = ESRCH;
1056 	    goto out;
1057 	}
1058 
1059 	/* Do single-step fixup if needed. */
1060 	FIX_SSTEP(t);
1061 	KASSERT(lt != NULL);
1062 	lwp_addref(lt);
1063 
1064 	/*
1065 	 * Which locks do we need held? XXX Ugly.
1066 	 */
1067 	if ((pheld = ptrace_needs_hold(req)) == 0) {
1068 		mutex_exit(t->p_lock);
1069 		mutex_exit(proc_lock);
1070 	}
1071 
1072 	/* Now do the operation. */
1073 	write = 0;
1074 	*retval = 0;
1075 	tmp = 0;
1076 	resume_all = 1;
1077 
1078 	switch (req) {
1079 	case PT_TRACE_ME:
1080 		/* Just set the trace flag. */
1081 		SET(t->p_slflag, PSL_TRACED);
1082 		t->p_opptr = t->p_pptr;
1083 		break;
1084 
1085 	/*
1086 	 * The I and D separate address space has been inherited from PDP-11.
1087 	 * The 16-bit UNIX started with a single address space per program,
1088 	 * but was extended to two 16-bit (2 x 64kb) address spaces.
1089 	 *
1090 	 * We no longer maintain this feature in maintained architectures, but
1091 	 * we keep the API for backward compatiblity. Currently the I and D
1092 	 * operations are exactly the same and not distinguished in debuggers.
1093 	 */
1094 	case PT_WRITE_I:
1095 	case PT_WRITE_D:
1096 		write = 1;
1097 		tmp = data;
1098 		/* FALLTHROUGH */
1099 	case PT_READ_I:
1100 	case PT_READ_D:
1101 		piod.piod_addr = &tmp;
1102 		piod.piod_len = sizeof(tmp);
1103 		piod.piod_offs = addr;
1104 		piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D;
1105 		if ((error = ptrace_doio(l, t, lt, &piod, addr, true)) != 0)
1106 			break;
1107 		if (!write)
1108 			*retval = tmp;
1109 		break;
1110 
1111 	case PT_IO:
1112 		if ((error = ptm->ptm_copyin_piod(&piod, addr, data)) != 0)
1113 			break;
1114 		if ((error = ptrace_doio(l, t, lt, &piod, addr, false)) != 0)
1115 			break;
1116 		error = ptm->ptm_copyout_piod(&piod, addr, data);
1117 		break;
1118 
1119 	case PT_DUMPCORE:
1120 		error = ptrace_dumpcore(lt, addr, data);
1121 		break;
1122 
1123 #ifdef PT_STEP
1124 	case PT_STEP:
1125 		/*
1126 		 * From the 4.4BSD PRM:
1127 		 * "Execution continues as in request PT_CONTINUE; however
1128 		 * as soon as possible after execution of at least one
1129 		 * instruction, execution stops again. [ ... ]"
1130 		 */
1131 #endif
1132 	case PT_CONTINUE:
1133 	case PT_SYSCALL:
1134 	case PT_DETACH:
1135 		if (req == PT_SYSCALL) {
1136 			if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
1137 				SET(t->p_slflag, PSL_SYSCALL);
1138 #ifdef __HAVE_SYSCALL_INTERN
1139 				(*t->p_emul->e_syscall_intern)(t);
1140 #endif
1141 			}
1142 		} else {
1143 			if (ISSET(t->p_slflag, PSL_SYSCALL)) {
1144 				CLR(t->p_slflag, PSL_SYSCALL);
1145 #ifdef __HAVE_SYSCALL_INTERN
1146 				(*t->p_emul->e_syscall_intern)(t);
1147 #endif
1148 			}
1149 		}
1150 		t->p_trace_enabled = trace_is_enabled(t);
1151 
1152 		/*
1153 		 * Pick up the LWPID, if supplied.  There are two cases:
1154 		 * data < 0 : step or continue single thread, lwp = -data
1155 		 * data > 0 in PT_STEP : step this thread, continue others
1156 		 * For operations other than PT_STEP, data > 0 means
1157 		 * data is the signo to deliver to the process.
1158 		 */
1159 		tmp = data;
1160 		if (tmp >= 0) {
1161 #ifdef PT_STEP
1162 			if (req == PT_STEP)
1163 				signo = 0;
1164 			else
1165 #endif
1166 			{
1167 				signo = tmp;
1168 				tmp = 0;	/* don't search for LWP */
1169 			}
1170 		} else
1171 			tmp = -tmp;
1172 
1173 		if (tmp > 0) {
1174 			if (req == PT_DETACH) {
1175 				error = EINVAL;
1176 				break;
1177 			}
1178 			lwp_delref2 (lt);
1179 			lt = lwp_find(t, tmp);
1180 			if (lt == NULL) {
1181 				error = ESRCH;
1182 				break;
1183 			}
1184 			lwp_addref(lt);
1185 			resume_all = 0;
1186 			signo = 0;
1187 		}
1188 
1189 		/*
1190 		 * From the 4.4BSD PRM:
1191 		 * "The data argument is taken as a signal number and the
1192 		 * child's execution continues at location addr as if it
1193 		 * incurred that signal.  Normally the signal number will
1194 		 * be either 0 to indicate that the signal that caused the
1195 		 * stop should be ignored, or that value fetched out of
1196 		 * the process's image indicating which signal caused
1197 		 * the stop.  If addr is (int *)1 then execution continues
1198 		 * from where it stopped."
1199 		 */
1200 
1201 		/* Check that the data is a valid signal number or zero. */
1202 		if (signo < 0 || signo >= NSIG) {
1203 			error = EINVAL;
1204 			break;
1205 		}
1206 
1207 		/* Prevent process deadlock */
1208 		if (resume_all) {
1209 #ifdef PT_STEP
1210 			if (req == PT_STEP) {
1211 				if (lt->l_flag & LW_WSUSPEND) {
1212 					error = EDEADLK;
1213 					break;
1214 				}
1215 			} else
1216 #endif
1217 			{
1218 				error = EDEADLK;
1219 				LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1220 					if ((lt2->l_flag & LW_WSUSPEND) == 0) {
1221 						error = 0;
1222 						break;
1223 					}
1224 				}
1225 				if (error != 0)
1226 					break;
1227 			}
1228 		} else {
1229 			if (lt->l_flag & LW_WSUSPEND) {
1230 				error = EDEADLK;
1231 				break;
1232 			}
1233 		}
1234 
1235 		/* If the address parameter is not (int *)1, set the pc. */
1236 		if ((int *)addr != (int *)1) {
1237 			error = process_set_pc(lt, addr);
1238 			if (error != 0)
1239 				break;
1240 		}
1241 #ifdef PT_STEP
1242 		/*
1243 		 * Arrange for a single-step, if that's requested and possible.
1244 		 * More precisely, set the single step status as requested for
1245 		 * the requested thread, and clear it for other threads.
1246 		 */
1247 		LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1248 			if (ISSET(lt2->l_pflag, LP_SINGLESTEP)) {
1249 				lwp_lock(lt2);
1250 				process_sstep(lt2, 1);
1251 				lwp_unlock(lt2);
1252 			} else if (lt != lt2) {
1253 				lwp_lock(lt2);
1254 				process_sstep(lt2, 0);
1255 				lwp_unlock(lt2);
1256 			}
1257 		}
1258 		error = process_sstep(lt,
1259 		    ISSET(lt->l_pflag, LP_SINGLESTEP) || req == PT_STEP);
1260 		if (error)
1261 			break;
1262 #endif
1263 		if (req == PT_DETACH) {
1264 			CLR(t->p_slflag, PSL_TRACED|PSL_SYSCALL);
1265 
1266 			/* give process back to original parent or init */
1267 			if (t->p_opptr != t->p_pptr) {
1268 				struct proc *pp = t->p_opptr;
1269 				proc_reparent(t, pp ? pp : initproc);
1270 			}
1271 
1272 			/* not being traced any more */
1273 			t->p_opptr = NULL;
1274 
1275 			/* clear single step */
1276 			LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1277 				CLR(lt2->l_pflag, LP_SINGLESTEP);
1278 			}
1279 			CLR(lt->l_pflag, LP_SINGLESTEP);
1280 		}
1281 	sendsig:
1282 		error = ptrace_sendsig(t, lt, signo, resume_all);
1283 		break;
1284 
1285 	case PT_SYSCALLEMU:
1286 		if (!ISSET(t->p_slflag, PSL_SYSCALL) || t->p_stat != SSTOP) {
1287 			error = EINVAL;
1288 			break;
1289 		}
1290 		SET(t->p_slflag, PSL_SYSCALLEMU);
1291 		break;
1292 
1293 #ifdef PT_STEP
1294 	case PT_SETSTEP:
1295 		write = 1;
1296 
1297 	case PT_CLEARSTEP:
1298 		/* write = 0 done above. */
1299 		if ((error = ptrace_update_lwp(t, &lt, data)) != 0)
1300 			break;
1301 
1302 		if (write)
1303 			SET(lt->l_pflag, LP_SINGLESTEP);
1304 		else
1305 			CLR(lt->l_pflag, LP_SINGLESTEP);
1306 		break;
1307 #endif
1308 
1309 	case PT_KILL:
1310 		/* just send the process a KILL signal. */
1311 		signo = SIGKILL;
1312 		goto sendsig;	/* in PT_CONTINUE, above. */
1313 
1314 	case PT_ATTACH:
1315 		/*
1316 		 * Go ahead and set the trace flag.
1317 		 * Save the old parent (it's reset in
1318 		 *   _DETACH, and also in kern_exit.c:wait4()
1319 		 * Reparent the process so that the tracing
1320 		 *   proc gets to see all the action.
1321 		 * Stop the target.
1322 		 */
1323 		proc_changeparent(t, p);
1324 		signo = SIGSTOP;
1325 		goto sendsig;
1326 
1327 	case PT_GET_EVENT_MASK:
1328 		error = ptrace_get_event_mask(t, addr, data);
1329 		break;
1330 
1331 	case PT_SET_EVENT_MASK:
1332 		error = ptrace_set_event_mask(t, addr, data);
1333 		break;
1334 
1335 	case PT_GET_PROCESS_STATE:
1336 		error = ptrace_get_process_state(t, addr, data);
1337 		break;
1338 
1339 	case PT_LWPINFO:
1340 		error = ptrace_lwpinfo(t, &lt, addr, data);
1341 		break;
1342 
1343 	case PT_SET_SIGINFO:
1344 		error = ptrace_set_siginfo(t, &lt, ptm, addr, data);
1345 		break;
1346 
1347 	case PT_GET_SIGINFO:
1348 		error = ptrace_get_siginfo(t, ptm, addr, data);
1349 		break;
1350 
1351 	case PT_RESUME:
1352 	case PT_SUSPEND:
1353 		error = ptrace_startstop(t, &lt, req, addr, data);
1354 		break;
1355 
1356 #ifdef PT_REGISTERS
1357 	case_PT_SETREGS
1358 	case_PT_GETREGS
1359 	case_PT_SETFPREGS
1360 	case_PT_GETFPREGS
1361 	case_PT_SETDBREGS
1362 	case_PT_GETDBREGS
1363 		error = ptrace_regs(l, &lt, req, ptm, addr, data);
1364 		break;
1365 #endif
1366 
1367 #ifdef __HAVE_PTRACE_MACHDEP
1368 	PTRACE_MACHDEP_REQUEST_CASES
1369 		error = ptrace_machdep_dorequest(l, lt, req, addr, data);
1370 		break;
1371 #endif
1372 	}
1373 
1374 out:
1375 	if (pheld) {
1376 		mutex_exit(t->p_lock);
1377 		mutex_exit(proc_lock);
1378 	}
1379 	if (lt != NULL)
1380 		lwp_delref(lt);
1381 	rw_exit(&t->p_reflock);
1382 
1383 	return error;
1384 }
1385 
1386 typedef int (*regrfunc_t)(struct lwp *, void *, size_t *);
1387 typedef int (*regwfunc_t)(struct lwp *, void *, size_t);
1388 
1389 #ifdef PT_REGISTERS
1390 static int
1391 proc_regio(struct lwp *l, struct uio *uio, size_t ks, regrfunc_t r,
1392     regwfunc_t w)
1393 {
1394 	char buf[1024];
1395 	int error;
1396 	char *kv;
1397 	size_t kl;
1398 
1399 	if (ks > sizeof(buf))
1400 		return E2BIG;
1401 
1402 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)ks)
1403 		return EINVAL;
1404 
1405 	kv = buf + uio->uio_offset;
1406 	kl = ks - uio->uio_offset;
1407 
1408 	if (kl > uio->uio_resid)
1409 		kl = uio->uio_resid;
1410 
1411 	error = (*r)(l, buf, &ks);
1412 	if (error == 0)
1413 		error = uiomove(kv, kl, uio);
1414 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1415 		if (l->l_stat != LSSTOP)
1416 			error = EBUSY;
1417 		else
1418 			error = (*w)(l, buf, ks);
1419 	}
1420 
1421 	uio->uio_offset = 0;
1422 	return error;
1423 }
1424 #endif
1425 
1426 int
1427 process_doregs(struct lwp *curl /*tracer*/,
1428     struct lwp *l /*traced*/,
1429     struct uio *uio)
1430 {
1431 #if defined(PT_GETREGS) || defined(PT_SETREGS)
1432 	size_t s;
1433 	regrfunc_t r;
1434 	regwfunc_t w;
1435 
1436 #ifdef COMPAT_NETBSD32
1437 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1438 
1439 	if (__predict_false(pk32)) {
1440 		s = sizeof(process_reg32);
1441 		r = (regrfunc_t)process_read_regs32;
1442 		w = (regwfunc_t)process_write_regs32;
1443 	} else
1444 #endif
1445 	{
1446 		s = sizeof(struct reg);
1447 		r = (regrfunc_t)process_read_regs;
1448 		w = (regwfunc_t)process_write_regs;
1449 	}
1450 	return proc_regio(l, uio, s, r, w);
1451 #else
1452 	return EINVAL;
1453 #endif
1454 }
1455 
1456 int
1457 process_validregs(struct lwp *l)
1458 {
1459 
1460 #if defined(PT_SETREGS) || defined(PT_GETREGS)
1461 	return (l->l_flag & LW_SYSTEM) == 0;
1462 #else
1463 	return 0;
1464 #endif
1465 }
1466 
1467 int
1468 process_dofpregs(struct lwp *curl /*tracer*/,
1469     struct lwp *l /*traced*/,
1470     struct uio *uio)
1471 {
1472 #if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
1473 	size_t s;
1474 	regrfunc_t r;
1475 	regwfunc_t w;
1476 
1477 #ifdef COMPAT_NETBSD32
1478 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1479 
1480 	if (__predict_false(pk32)) {
1481 		s = sizeof(process_fpreg32);
1482 		r = (regrfunc_t)process_read_fpregs32;
1483 		w = (regwfunc_t)process_write_fpregs32;
1484 	} else
1485 #endif
1486 	{
1487 		s = sizeof(struct fpreg);
1488 		r = (regrfunc_t)process_read_fpregs;
1489 		w = (regwfunc_t)process_write_fpregs;
1490 	}
1491 	return proc_regio(l, uio, s, r, w);
1492 #else
1493 	return EINVAL;
1494 #endif
1495 }
1496 
1497 int
1498 process_validfpregs(struct lwp *l)
1499 {
1500 
1501 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
1502 	return (l->l_flag & LW_SYSTEM) == 0;
1503 #else
1504 	return 0;
1505 #endif
1506 }
1507 
1508 int
1509 process_dodbregs(struct lwp *curl /*tracer*/,
1510     struct lwp *l /*traced*/,
1511     struct uio *uio)
1512 {
1513 #if defined(PT_GETDBREGS) || defined(PT_SETDBREGS)
1514 	size_t s;
1515 	regrfunc_t r;
1516 	regwfunc_t w;
1517 
1518 #ifdef COMPAT_NETBSD32
1519 	const bool pk32 = (l->l_proc->p_flag & PK_32) != 0;
1520 
1521 	if (__predict_false(pk32)) {
1522 		s = sizeof(process_dbreg32);
1523 		r = (regrfunc_t)process_read_dbregs32;
1524 		w = (regwfunc_t)process_write_dbregs32;
1525 	} else
1526 #endif
1527 	{
1528 		s = sizeof(struct dbreg);
1529 		r = (regrfunc_t)process_read_dbregs;
1530 		w = (regwfunc_t)process_write_dbregs;
1531 	}
1532 	return proc_regio(l, uio, s, r, w);
1533 #else
1534 	return EINVAL;
1535 #endif
1536 }
1537 
1538 int
1539 process_validdbregs(struct lwp *l)
1540 {
1541 
1542 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
1543 	return (l->l_flag & LW_SYSTEM) == 0;
1544 #else
1545 	return 0;
1546 #endif
1547 }
1548 
1549 static int
1550 process_auxv_offset(struct proc *p, struct uio *uio)
1551 {
1552 	struct ps_strings pss;
1553 	int error;
1554 	off_t off = (off_t)p->p_psstrp;
1555 
1556 	if ((error = copyin_psstrings(p, &pss)) != 0)
1557 		return error;
1558 
1559 	if (pss.ps_envstr == NULL)
1560 		return EIO;
1561 
1562 	uio->uio_offset += (off_t)(vaddr_t)(pss.ps_envstr + pss.ps_nenvstr + 1);
1563 #ifdef __MACHINE_STACK_GROWS_UP
1564 	if (uio->uio_offset < off)
1565 		return EIO;
1566 #else
1567 	if (uio->uio_offset > off)
1568 		return EIO;
1569 	if ((uio->uio_offset + uio->uio_resid) > off)
1570 		uio->uio_resid = off - uio->uio_offset;
1571 #endif
1572 	return 0;
1573 }
1574 #endif /* PTRACE */
1575 
1576 MODULE(MODULE_CLASS_EXEC, ptrace_common, "");
1577 
1578 static int
1579 ptrace_common_modcmd(modcmd_t cmd, void *arg)
1580 {
1581         int error;
1582 
1583         switch (cmd) {
1584         case MODULE_CMD_INIT:
1585                 error = ptrace_init();
1586                 break;
1587         case MODULE_CMD_FINI:
1588                 error = ptrace_fini();
1589                 break;
1590         default:
1591 		ptrace_hooks();
1592                 error = ENOTTY;
1593                 break;
1594         }
1595         return error;
1596 }
1597