xref: /netbsd-src/sys/kern/sys_ptrace_common.c (revision 7330f729ccf0bd976a06f95fad452fe774fc7fd1)
1 /*	$NetBSD: sys_ptrace_common.c,v 1.69 2019/10/16 18:29:49 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 1.69 2019/10/16 18:29:49 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 extern int user_va0_disable;
167 
168 #if 0
169 static int ptrace_cbref;
170 static kmutex_t ptrace_mtx;
171 static kcondvar_t ptrace_cv;
172 #endif
173 
174 #ifdef PT_GETREGS
175 # define case_PT_GETREGS	case PT_GETREGS:
176 #else
177 # define case_PT_GETREGS
178 #endif
179 
180 #ifdef PT_SETREGS
181 # define case_PT_SETREGS	case PT_SETREGS:
182 #else
183 # define case_PT_SETREGS
184 #endif
185 
186 #ifdef PT_GETFPREGS
187 # define case_PT_GETFPREGS	case PT_GETFPREGS:
188 #else
189 # define case_PT_GETFPREGS
190 #endif
191 
192 #ifdef PT_SETFPREGS
193 # define case_PT_SETFPREGS	case PT_SETFPREGS:
194 #else
195 # define case_PT_SETFPREGS
196 #endif
197 
198 #ifdef PT_GETDBREGS
199 # define case_PT_GETDBREGS	case PT_GETDBREGS:
200 #else
201 # define case_PT_GETDBREGS
202 #endif
203 
204 #ifdef PT_SETDBREGS
205 # define case_PT_SETDBREGS	case PT_SETDBREGS:
206 #else
207 # define case_PT_SETDBREGS
208 #endif
209 
210 #if defined(PT_SETREGS) || defined(PT_GETREGS) || \
211     defined(PT_SETFPREGS) || defined(PT_GETFPREGS) || \
212     defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
213 # define PT_REGISTERS
214 #endif
215 
216 static int
217 ptrace_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
218     void *arg0, void *arg1, void *arg2, void *arg3)
219 {
220 	struct proc *p;
221 	int result;
222 #ifdef PT_SETDBREGS
223 	extern int user_set_dbregs;
224 #endif
225 
226 	result = KAUTH_RESULT_DEFER;
227 	p = arg0;
228 
229 #if 0
230 	mutex_enter(&ptrace_mtx);
231 	ptrace_cbref++;
232 	mutex_exit(&ptrace_mtx);
233 #endif
234 	if (action != KAUTH_PROCESS_PTRACE)
235 		goto out;
236 
237 	switch ((u_long)arg1) {
238 #ifdef PT_SETDBREGS
239 	case_PT_SETDBREGS
240 		if (kauth_cred_getuid(cred) != 0 && user_set_dbregs == 0) {
241 			result = KAUTH_RESULT_DENY;
242 			break;
243 		}
244 #endif
245 		/* FALLTHROUGH */
246 	case PT_TRACE_ME:
247 	case PT_ATTACH:
248 	case PT_WRITE_I:
249 	case PT_WRITE_D:
250 	case PT_READ_I:
251 	case PT_READ_D:
252 	case PT_IO:
253 	case_PT_GETREGS
254 	case_PT_SETREGS
255 	case_PT_GETFPREGS
256 	case_PT_SETFPREGS
257 	case_PT_GETDBREGS
258 	case PT_SET_EVENT_MASK:
259 	case PT_GET_EVENT_MASK:
260 	case PT_GET_PROCESS_STATE:
261 	case PT_SET_SIGINFO:
262 	case PT_GET_SIGINFO:
263 #ifdef __HAVE_PTRACE_MACHDEP
264 	PTRACE_MACHDEP_REQUEST_CASES
265 #endif
266 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
267 		    ISSET(p->p_flag, PK_SUGID)) {
268 			break;
269 		}
270 
271 		result = KAUTH_RESULT_ALLOW;
272 
273 	break;
274 
275 #ifdef PT_STEP
276 	case PT_STEP:
277 	case PT_SETSTEP:
278 	case PT_CLEARSTEP:
279 #endif
280 	case PT_CONTINUE:
281 	case PT_KILL:
282 	case PT_DETACH:
283 	case PT_LWPINFO:
284 	case PT_SYSCALL:
285 	case PT_SYSCALLEMU:
286 	case PT_DUMPCORE:
287 	case PT_RESUME:
288 	case PT_SUSPEND:
289 	case PT_STOP:
290 		result = KAUTH_RESULT_ALLOW;
291 		break;
292 
293 	default:
294 		break;
295 	}
296 
297  out:
298 #if 0
299 	mutex_enter(&ptrace_mtx);
300 	if (--ptrace_cbref == 0)
301 		cv_broadcast(&ptrace_cv);
302 	mutex_exit(&ptrace_mtx);
303 #endif
304 
305 	return result;
306 }
307 
308 int
309 ptrace_init(void)
310 {
311 
312 #if 0
313 	mutex_init(&ptrace_mtx, MUTEX_DEFAULT, IPL_NONE);
314 	cv_init(&ptrace_cv, "ptracecb");
315 	ptrace_cbref = 0;
316 #endif
317 	ptrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
318 	    ptrace_listener_cb, NULL);
319 	return 0;
320 }
321 
322 int
323 ptrace_fini(void)
324 {
325 
326 	kauth_unlisten_scope(ptrace_listener);
327 
328 #if 0
329 	/* Make sure no-one is executing our kauth listener */
330 
331 	mutex_enter(&ptrace_mtx);
332 	while (ptrace_cbref != 0)
333 		cv_wait(&ptrace_cv, &ptrace_mtx);
334 	mutex_exit(&ptrace_mtx);
335 	mutex_destroy(&ptrace_mtx);
336 	cv_destroy(&ptrace_cv);
337 #endif
338 
339 	return 0;
340 }
341 
342 static struct proc *
343 ptrace_find(struct lwp *l, int req, pid_t pid)
344 {
345 	struct proc *t;
346 
347 	/* "A foolish consistency..." XXX */
348 	if (req == PT_TRACE_ME) {
349 		t = l->l_proc;
350 		mutex_enter(t->p_lock);
351 		return t;
352 	}
353 
354 	/* Find the process we're supposed to be operating on. */
355 	t = proc_find(pid);
356 	if (t == NULL)
357 		return NULL;
358 
359 	/* XXX-elad */
360 	mutex_enter(t->p_lock);
361 	int error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
362 	    t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
363 	if (error) {
364 		mutex_exit(t->p_lock);
365 		return NULL;
366 	}
367 	return t;
368 }
369 
370 static int
371 ptrace_allowed(struct lwp *l, int req, struct proc *t, struct proc *p,
372     bool *locked)
373 {
374 	*locked = false;
375 
376 	/*
377 	 * Grab a reference on the process to prevent it from execing or
378 	 * exiting.
379 	 */
380 	if (!rw_tryenter(&t->p_reflock, RW_READER))
381 		return EBUSY;
382 
383 	*locked = true;
384 
385 	/* Make sure we can operate on it. */
386 	switch (req) {
387 	case PT_TRACE_ME:
388 		/*
389 		 * You can't say to the parent of a process to start tracing if:
390 		 *	(1) the parent is initproc,
391 		 */
392 		if (p->p_pptr == initproc)
393 			return EPERM;
394 
395 		/*
396 		 *	(2) the process is initproc, or
397 		 */
398 		if (p == initproc)
399 			return EPERM;
400 
401 		/*
402 		 *	(3) the child is already traced.
403 		 */
404 		if (ISSET(p->p_slflag, PSL_TRACED))
405 			return EBUSY;
406 
407 		return 0;
408 
409 	case PT_ATTACH:
410 		/*
411 		 * You can't attach to a process if:
412 		 *	(1) it's the process that's doing the attaching,
413 		 */
414 		if (t == p)
415 			return EINVAL;
416 
417 		/*
418 		 *	(2) it's a system process,
419 		 */
420 		if (t->p_flag & PK_SYSTEM)
421 			return EPERM;
422 
423 		/*
424 		 *	(3) the tracer is initproc,
425 		 */
426 		if (p == initproc)
427 			return EPERM;
428 
429 		/*
430 		 *	(4) it's already being traced,
431 		 */
432 		if (ISSET(t->p_slflag, PSL_TRACED))
433 			return EBUSY;
434 
435 		/*
436 		 *	(5) it's a vfork(2)ed parent of the current process, or
437 		 */
438 		if (ISSET(p->p_lflag, PL_PPWAIT) && p->p_pptr == t)
439 			return EPERM;
440 
441 		/*
442 		 * 	(6) the tracer is chrooted, and its root directory is
443 		 * 	    not at or above the root directory of the tracee
444 		 */
445 		mutex_exit(t->p_lock);	/* XXXSMP */
446 		int tmp = proc_isunder(t, l);
447 		mutex_enter(t->p_lock);	/* XXXSMP */
448 		if (!tmp)
449 			return EPERM;
450 		return 0;
451 
452 	case PT_READ_I:
453 	case PT_READ_D:
454 	case PT_WRITE_I:
455 	case PT_WRITE_D:
456 	case PT_IO:
457 	case PT_SET_SIGINFO:
458 	case PT_GET_SIGINFO:
459 	case_PT_GETREGS
460 	case_PT_SETREGS
461 	case_PT_GETFPREGS
462 	case_PT_SETFPREGS
463 	case_PT_GETDBREGS
464 	case_PT_SETDBREGS
465 #ifdef __HAVE_PTRACE_MACHDEP
466 	PTRACE_MACHDEP_REQUEST_CASES
467 #endif
468 		/*
469 		 * You can't read/write the memory or registers of a process
470 		 * if the tracer is chrooted, and its root directory is not at
471 		 * or above the root directory of the tracee.
472 		 */
473 		mutex_exit(t->p_lock);	/* XXXSMP */
474 		tmp = proc_isunder(t, l);
475 		mutex_enter(t->p_lock);	/* XXXSMP */
476 		if (!tmp)
477 			return EPERM;
478 		/*FALLTHROUGH*/
479 
480 	case PT_CONTINUE:
481 	case PT_KILL:
482 	case PT_DETACH:
483 	case PT_LWPINFO:
484 	case PT_SYSCALL:
485 	case PT_SYSCALLEMU:
486 	case PT_DUMPCORE:
487 #ifdef PT_STEP
488 	case PT_STEP:
489 	case PT_SETSTEP:
490 	case PT_CLEARSTEP:
491 #endif
492 	case PT_SET_EVENT_MASK:
493 	case PT_GET_EVENT_MASK:
494 	case PT_GET_PROCESS_STATE:
495 	case PT_RESUME:
496 	case PT_SUSPEND:
497 	case PT_STOP:
498 		/*
499 		 * You can't do what you want to the process if:
500 		 *	(1) It's not being traced at all,
501 		 */
502 		if (!ISSET(t->p_slflag, PSL_TRACED))
503 			return EPERM;
504 
505 		/*
506 		 *	(2) it's not being traced by _you_, or
507 		 */
508 		if (t->p_pptr != p) {
509 			DPRINTF(("parent %d != %d\n", t->p_pptr->p_pid,
510 			    p->p_pid));
511 			return EBUSY;
512 		}
513 
514 		/*
515 		 *	(3) it's not currently stopped.
516 		 *
517 		 *	As an exception allow PT_KILL and PT_STOP here.
518 		 */
519 		if (req != PT_KILL && req != PT_STOP &&
520 		    (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */)) {
521 			DPRINTF(("stat %d flag %d\n", t->p_stat,
522 			    !t->p_waited));
523 			return EBUSY;
524 		}
525 		return 0;
526 
527 	default:			/* It was not a legal request. */
528 		return EINVAL;
529 	}
530 }
531 
532 static int
533 ptrace_needs_hold(int req)
534 {
535 	switch (req) {
536 #ifdef PT_STEP
537 	case PT_STEP:
538 #endif
539 	case PT_CONTINUE:
540 	case PT_DETACH:
541 	case PT_KILL:
542 	case PT_SYSCALL:
543 	case PT_SYSCALLEMU:
544 	case PT_ATTACH:
545 	case PT_TRACE_ME:
546 	case PT_GET_SIGINFO:
547 	case PT_SET_SIGINFO:
548 	case PT_STOP:
549 		return 1;
550 	default:
551 		return 0;
552 	}
553 }
554 
555 static int
556 ptrace_update_lwp(struct proc *t, struct lwp **lt, lwpid_t lid)
557 {
558 	if (lid == 0 || lid == (*lt)->l_lid || t->p_nlwps == 1)
559 		return 0;
560 
561 	mutex_enter(t->p_lock);
562 	lwp_delref2(*lt);
563 
564 	*lt = lwp_find(t, lid);
565 	if (*lt == NULL) {
566 		mutex_exit(t->p_lock);
567 		return ESRCH;
568 	}
569 
570 	if ((*lt)->l_flag & LW_SYSTEM) {
571 		mutex_exit(t->p_lock);
572 		*lt = NULL;
573 		return EINVAL;
574 	}
575 
576 	lwp_addref(*lt);
577 	mutex_exit(t->p_lock);
578 
579 	return 0;
580 }
581 
582 static int
583 ptrace_get_siginfo(struct proc *t, struct ptrace_methods *ptm, void *addr,
584     size_t data)
585 {
586 	struct ptrace_siginfo psi;
587 
588 	memset(&psi, 0, sizeof(psi));
589 	psi.psi_siginfo._info = t->p_sigctx.ps_info;
590 	psi.psi_lwpid = t->p_sigctx.ps_lwp;
591 	DPRINTF(("%s: lwp=%d signal=%d\n", __func__, psi.psi_lwpid,
592 	    psi.psi_siginfo.si_signo));
593 
594 	return ptm->ptm_copyout_siginfo(&psi, addr, data);
595 }
596 
597 static int
598 ptrace_set_siginfo(struct proc *t, struct lwp **lt, struct ptrace_methods *ptm,
599     void *addr, size_t data)
600 {
601 	struct ptrace_siginfo psi;
602 
603 	int error = ptm->ptm_copyin_siginfo(&psi, addr, data);
604 	if (error)
605 		return error;
606 
607 	/* Check that the data is a valid signal number or zero. */
608 	if (psi.psi_siginfo.si_signo < 0 || psi.psi_siginfo.si_signo >= NSIG)
609 		return EINVAL;
610 
611 	t->p_sigctx.ps_faked = true;
612 	t->p_sigctx.ps_info = psi.psi_siginfo._info;
613 	t->p_sigctx.ps_lwp = psi.psi_lwpid;
614 	DPRINTF(("%s: lwp=%d signal=%d\n", __func__, psi.psi_lwpid,
615 	    psi.psi_siginfo.si_signo));
616 	return 0;
617 }
618 
619 static int
620 ptrace_get_event_mask(struct proc *t, void *addr, size_t data)
621 {
622 	struct ptrace_event pe;
623 
624 	if (data != sizeof(pe)) {
625 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
626 		return EINVAL;
627 	}
628 	memset(&pe, 0, sizeof(pe));
629 	pe.pe_set_event = ISSET(t->p_slflag, PSL_TRACEFORK) ?
630 	    PTRACE_FORK : 0;
631 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK) ?
632 	    PTRACE_VFORK : 0;
633 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK_DONE) ?
634 	    PTRACE_VFORK_DONE : 0;
635 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_CREATE) ?
636 	    PTRACE_LWP_CREATE : 0;
637 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_EXIT) ?
638 	    PTRACE_LWP_EXIT : 0;
639 	pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEPOSIX_SPAWN) ?
640 	    PTRACE_POSIX_SPAWN : 0;
641 	DPRINTF(("%s: lwp=%d event=%#x\n", __func__,
642 	    t->p_sigctx.ps_lwp, pe.pe_set_event));
643 	return copyout(&pe, addr, sizeof(pe));
644 }
645 
646 static int
647 ptrace_set_event_mask(struct proc *t, void *addr, size_t data)
648 {
649 	struct ptrace_event pe;
650 	int error;
651 
652 	if (data != sizeof(pe)) {
653 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pe)));
654 		return EINVAL;
655 	}
656 	if ((error = copyin(addr, &pe, sizeof(pe))) != 0)
657 		return error;
658 
659 	DPRINTF(("%s: lwp=%d event=%#x\n", __func__,
660 	    t->p_sigctx.ps_lwp, pe.pe_set_event));
661 	if (pe.pe_set_event & PTRACE_FORK)
662 		SET(t->p_slflag, PSL_TRACEFORK);
663 	else
664 		CLR(t->p_slflag, PSL_TRACEFORK);
665 
666 	if (pe.pe_set_event & PTRACE_VFORK)
667 		SET(t->p_slflag, PSL_TRACEVFORK);
668 	else
669 		CLR(t->p_slflag, PSL_TRACEVFORK);
670 
671 	if (pe.pe_set_event & PTRACE_VFORK_DONE)
672 		SET(t->p_slflag, PSL_TRACEVFORK_DONE);
673 	else
674 		CLR(t->p_slflag, PSL_TRACEVFORK_DONE);
675 
676 	if (pe.pe_set_event & PTRACE_LWP_CREATE)
677 		SET(t->p_slflag, PSL_TRACELWP_CREATE);
678 	else
679 		CLR(t->p_slflag, PSL_TRACELWP_CREATE);
680 
681 	if (pe.pe_set_event & PTRACE_LWP_EXIT)
682 		SET(t->p_slflag, PSL_TRACELWP_EXIT);
683 	else
684 		CLR(t->p_slflag, PSL_TRACELWP_EXIT);
685 
686 	if (pe.pe_set_event & PTRACE_POSIX_SPAWN)
687 		SET(t->p_slflag, PSL_TRACEPOSIX_SPAWN);
688 	else
689 		CLR(t->p_slflag, PSL_TRACEPOSIX_SPAWN);
690 
691 	return 0;
692 }
693 
694 static int
695 ptrace_get_process_state(struct proc *t, void *addr, size_t data)
696 {
697 	struct _ksiginfo *si;
698 	struct ptrace_state ps;
699 
700 	if (data != sizeof(ps)) {
701 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(ps)));
702 		return EINVAL;
703 	}
704 
705 	if (t->p_sigctx.ps_info._signo != SIGTRAP ||
706 	    (t->p_sigctx.ps_info._code != TRAP_CHLD &&
707 	        t->p_sigctx.ps_info._code != TRAP_LWP)) {
708 		memset(&ps, 0, sizeof(ps));
709 	} else {
710 		si = &t->p_sigctx.ps_info;
711 
712 		KASSERT(si->_reason._ptrace_state._pe_report_event > 0);
713 		KASSERT(si->_reason._ptrace_state._option._pe_other_pid > 0);
714 
715 		ps.pe_report_event = si->_reason._ptrace_state._pe_report_event;
716 
717 		CTASSERT(sizeof(ps.pe_other_pid) == sizeof(ps.pe_lwp));
718 		ps.pe_other_pid =
719 			si->_reason._ptrace_state._option._pe_other_pid;
720 	}
721 
722 	DPRINTF(("%s: lwp=%d event=%#x pid=%d lwp=%d\n", __func__,
723 	    t->p_sigctx.ps_lwp, ps.pe_report_event,
724 	    ps.pe_other_pid, ps.pe_lwp));
725 	return copyout(&ps, addr, sizeof(ps));
726 }
727 
728 static int
729 ptrace_lwpinfo(struct proc *t, struct lwp **lt, void *addr, size_t data)
730 {
731 	struct ptrace_lwpinfo pl;
732 
733 	if (data != sizeof(pl)) {
734 		DPRINTF(("%s: %zu != %zu\n", __func__, data, sizeof(pl)));
735 		return EINVAL;
736 	}
737 	int error = copyin(addr, &pl, sizeof(pl));
738 	if (error)
739 		return error;
740 
741 	lwpid_t tmp = pl.pl_lwpid;
742 	lwp_delref(*lt);
743 	mutex_enter(t->p_lock);
744 	if (tmp == 0)
745 		*lt = lwp_find_first(t);
746 	else {
747 		*lt = lwp_find(t, tmp);
748 		if (*lt == NULL) {
749 			mutex_exit(t->p_lock);
750 			return ESRCH;
751 		}
752 		*lt = LIST_NEXT(*lt, l_sibling);
753 	}
754 
755 	while (*lt != NULL && !lwp_alive(*lt))
756 		*lt = LIST_NEXT(*lt, l_sibling);
757 
758 	pl.pl_lwpid = 0;
759 	pl.pl_event = 0;
760 	if (*lt) {
761 		lwp_addref(*lt);
762 		pl.pl_lwpid = (*lt)->l_lid;
763 
764 		if ((*lt)->l_flag & LW_WSUSPEND)
765 			pl.pl_event = PL_EVENT_SUSPENDED;
766 		/*
767 		 * If we match the lwp, or it was sent to every lwp,
768 		 * we set PL_EVENT_SIGNAL.
769 		 * XXX: ps_lwp == 0 means everyone and noone, so
770 		 * check ps_signo too.
771 		 */
772 		else if ((*lt)->l_lid == t->p_sigctx.ps_lwp
773 			 || (t->p_sigctx.ps_lwp == 0 &&
774 			     t->p_sigctx.ps_info._signo)) {
775 			DPRINTF(("%s: lwp=%d siglwp=%d signo %d\n", __func__,
776 			    pl.pl_lwpid, t->p_sigctx.ps_lwp,
777 			    t->p_sigctx.ps_info._signo));
778 			pl.pl_event = PL_EVENT_SIGNAL;
779 		}
780 	}
781 	mutex_exit(t->p_lock);
782 	DPRINTF(("%s: lwp=%d event=%#x\n", __func__,
783 	    pl.pl_lwpid, pl.pl_event));
784 
785 	return copyout(&pl, addr, sizeof(pl));
786 }
787 
788 static int
789 ptrace_startstop(struct proc *t, struct lwp **lt, int rq, void *addr,
790     size_t data)
791 {
792 	int error;
793 
794 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
795 		return error;
796 
797 	DPRINTF(("%s: lwp=%d request=%d\n", __func__, (*lt)->l_lid, rq));
798 	lwp_lock(*lt);
799 	if (rq == PT_SUSPEND)
800 		(*lt)->l_flag |= LW_DBGSUSPEND;
801 	else {
802 		(*lt)->l_flag &= ~LW_DBGSUSPEND;
803 		if ((*lt)->l_flag != LSSUSPENDED)
804 			(*lt)->l_stat = LSSTOP;
805 	}
806 	lwp_unlock(*lt);
807 	return 0;
808 }
809 
810 #ifdef PT_REGISTERS
811 static int
812 ptrace_uio_dir(int req)
813 {
814 	switch (req) {
815 	case_PT_GETREGS
816 	case_PT_GETFPREGS
817 	case_PT_GETDBREGS
818 		return UIO_READ;
819 	case_PT_SETREGS
820 	case_PT_SETFPREGS
821 	case_PT_SETDBREGS
822 		return UIO_WRITE;
823 	default:
824 		return -1;
825 	}
826 }
827 
828 static int
829 ptrace_regs(struct lwp *l, struct lwp **lt, int rq, struct ptrace_methods *ptm,
830     void *addr, size_t data)
831 {
832 	int error;
833 	struct proc *t = (*lt)->l_proc;
834 	struct vmspace *vm;
835 
836 	if ((error = ptrace_update_lwp(t, lt, data)) != 0)
837 		return error;
838 
839 	int dir = ptrace_uio_dir(rq);
840 	size_t size;
841 	int (*func)(struct lwp *, struct lwp *, struct uio *);
842 
843 	DPRINTF(("%s: lwp=%d request=%d\n", __func__, l->l_lid, rq));
844 
845 	switch (rq) {
846 #if defined(PT_SETREGS) || defined(PT_GETREGS)
847 	case_PT_GETREGS
848 	case_PT_SETREGS
849 		if (!process_validregs(*lt))
850 			return EINVAL;
851 		size = PROC_REGSZ(t);
852 		func = ptm->ptm_doregs;
853 		break;
854 #endif
855 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
856 	case_PT_GETFPREGS
857 	case_PT_SETFPREGS
858 		if (!process_validfpregs(*lt))
859 			return EINVAL;
860 		size = PROC_FPREGSZ(t);
861 		func = ptm->ptm_dofpregs;
862 		break;
863 #endif
864 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
865 	case_PT_GETDBREGS
866 	case_PT_SETDBREGS
867 		if (!process_validdbregs(*lt))
868 			return EINVAL;
869 		size = PROC_DBREGSZ(t);
870 		func = ptm->ptm_dodbregs;
871 		break;
872 #endif
873 	default:
874 		return EINVAL;
875 	}
876 
877 	error = proc_vmspace_getref(l->l_proc, &vm);
878 	if (error)
879 		return error;
880 
881 	struct uio uio;
882 	struct iovec iov;
883 
884 	iov.iov_base = addr;
885 	iov.iov_len = size;
886 	uio.uio_iov = &iov;
887 	uio.uio_iovcnt = 1;
888 	uio.uio_offset = 0;
889 	uio.uio_resid = iov.iov_len;
890 	uio.uio_rw = dir;
891 	uio.uio_vmspace = vm;
892 
893 	error = (*func)(l, *lt, &uio);
894 	uvmspace_free(vm);
895 	return error;
896 }
897 #endif
898 
899 static int
900 ptrace_sendsig(struct lwp *l, int req, struct proc *t, struct lwp *lt, int signo, int resume_all)
901 {
902 	ksiginfo_t ksi;
903 
904 	/* Finally, deliver the requested signal (or none). */
905 	if (t->p_stat == SSTOP) {
906 		/*
907 		 * Unstop the process.  If it needs to take a
908 		 * signal, make all efforts to ensure that at
909 		 * an LWP runs to see it.
910 		 */
911 		t->p_xsig = signo;
912 
913 		/*
914 		 * signo > 0 check prevents a potential panic, as
915 		 * sigismember(&...,0) is invalid check and signo
916 		 * can be equal to 0 as a special case of no-signal.
917 		 */
918 		if (signo > 0 && sigismember(&stopsigmask, signo)) {
919 			t->p_waited = 0;
920 			child_psignal(t, 0);
921 		} else if (resume_all)
922 			proc_unstop(t);
923 		else
924 			lwp_unstop(lt);
925 		return 0;
926 	}
927 
928 	KASSERT(req == PT_KILL || req == PT_STOP || req == PT_ATTACH);
929 
930 	KSI_INIT(&ksi);
931 	ksi.ksi_signo = signo;
932 	ksi.ksi_code = SI_USER;
933 	ksi.ksi_pid = l->l_proc->p_pid;
934 	ksi.ksi_uid = kauth_cred_geteuid(l->l_cred);
935 
936 	t->p_sigctx.ps_faked = false;
937 
938 	DPRINTF(("%s: pid=%d.%d signal=%d resume_all=%d\n", __func__, t->p_pid,
939 	    lt->l_lid, signo, resume_all));
940 
941 	return kpsignal2(t, &ksi);
942 }
943 
944 static int
945 ptrace_dumpcore(struct lwp *lt, char *path, size_t len)
946 {
947 	int error;
948 	if (path != NULL) {
949 
950 		if (len >= MAXPATHLEN)
951 			return EINVAL;
952 
953 		char *src = path;
954 		path = kmem_alloc(len + 1, KM_SLEEP);
955 		error = copyin(src, path, len);
956 		if (error)
957 			goto out;
958 		path[len] = '\0';
959 	}
960 	DPRINTF(("%s: lwp=%d\n", __func__, lt->l_lid));
961 	error = (*coredump_vec)(lt, path);
962 out:
963 	if (path)
964 		kmem_free(path, len + 1);
965 	return error;
966 }
967 
968 static int
969 ptrace_doio(struct lwp *l, struct proc *t, struct lwp *lt,
970     struct ptrace_io_desc *piod, void *addr, bool sysspace)
971 {
972 	struct uio uio;
973 	struct iovec iov;
974 	int error, tmp;
975 
976 	error = 0;
977 	iov.iov_base = piod->piod_addr;
978 	iov.iov_len = piod->piod_len;
979 	uio.uio_iov = &iov;
980 	uio.uio_iovcnt = 1;
981 	uio.uio_offset = (off_t)(unsigned long)piod->piod_offs;
982 	uio.uio_resid = piod->piod_len;
983 
984 	DPRINTF(("%s: lwp=%d request=%d\n", __func__, l->l_lid, piod->piod_op));
985 
986 	switch (piod->piod_op) {
987 	case PIOD_READ_D:
988 	case PIOD_READ_I:
989 		uio.uio_rw = UIO_READ;
990 		break;
991 	case PIOD_WRITE_D:
992 	case PIOD_WRITE_I:
993 		/*
994 		 * Can't write to a RAS
995 		 */
996 		if (ras_lookup(t, addr) != (void *)-1) {
997 			return EACCES;
998 		}
999 		uio.uio_rw = UIO_WRITE;
1000 		break;
1001 	case PIOD_READ_AUXV:
1002 		uio.uio_rw = UIO_READ;
1003 		tmp = t->p_execsw->es_arglen;
1004 		if (uio.uio_offset > tmp)
1005 			return EIO;
1006 		if (uio.uio_resid > tmp - uio.uio_offset)
1007 			uio.uio_resid = tmp - uio.uio_offset;
1008 		piod->piod_len = iov.iov_len = uio.uio_resid;
1009 		error = process_auxv_offset(t, &uio);
1010 		break;
1011 	default:
1012 		error = EINVAL;
1013 		break;
1014 	}
1015 
1016 	if (error)
1017 		return error;
1018 
1019 	if (sysspace) {
1020 		uio.uio_vmspace = vmspace_kernel();
1021 	} else {
1022 		error = proc_vmspace_getref(l->l_proc, &uio.uio_vmspace);
1023 		if (error)
1024 			return error;
1025 	}
1026 
1027 	error = process_domem(l, lt, &uio);
1028 	if (!sysspace)
1029 		uvmspace_free(uio.uio_vmspace);
1030 	if (error)
1031 		return error;
1032 	piod->piod_len -= uio.uio_resid;
1033 	return 0;
1034 }
1035 
1036 int
1037 do_ptrace(struct ptrace_methods *ptm, struct lwp *l, int req, pid_t pid,
1038     void *addr, int data, register_t *retval)
1039 {
1040 	struct proc *p = l->l_proc;
1041 	struct lwp *lt = NULL;
1042 	struct lwp *lt2;
1043 	struct proc *t;				/* target process */
1044 	struct ptrace_io_desc piod;
1045 	int error, write, tmp, pheld;
1046 	int signo = 0;
1047 	int resume_all;
1048 	bool locked;
1049 	error = 0;
1050 
1051 	/*
1052 	 * If attaching or detaching, we need to get a write hold on the
1053 	 * proclist lock so that we can re-parent the target process.
1054 	 */
1055 	mutex_enter(proc_lock);
1056 
1057 	t = ptrace_find(l, req, pid);
1058 	if (t == NULL) {
1059 		mutex_exit(proc_lock);
1060 		return ESRCH;
1061 	}
1062 
1063 	pheld = 1;
1064 	if ((error = ptrace_allowed(l, req, t, p, &locked)) != 0)
1065 		goto out;
1066 
1067 	if ((error = kauth_authorize_process(l->l_cred,
1068 	    KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req), NULL, NULL)) != 0)
1069 		goto out;
1070 
1071 	if ((lt = lwp_find_first(t)) == NULL) {
1072 	    error = ESRCH;
1073 	    goto out;
1074 	}
1075 
1076 	/* Do single-step fixup if needed. */
1077 	FIX_SSTEP(t);
1078 	KASSERT(lt != NULL);
1079 	lwp_addref(lt);
1080 
1081 	/*
1082 	 * Which locks do we need held? XXX Ugly.
1083 	 */
1084 	if ((pheld = ptrace_needs_hold(req)) == 0) {
1085 		mutex_exit(t->p_lock);
1086 		mutex_exit(proc_lock);
1087 	}
1088 
1089 	/* Now do the operation. */
1090 	write = 0;
1091 	*retval = 0;
1092 	tmp = 0;
1093 	resume_all = 1;
1094 
1095 	switch (req) {
1096 	case PT_TRACE_ME:
1097 		/* Just set the trace flag. */
1098 		SET(t->p_slflag, PSL_TRACED);
1099 		t->p_opptr = t->p_pptr;
1100 		break;
1101 
1102 	/*
1103 	 * The I and D separate address space has been inherited from PDP-11.
1104 	 * The 16-bit UNIX started with a single address space per program,
1105 	 * but was extended to two 16-bit (2 x 64kb) address spaces.
1106 	 *
1107 	 * We no longer maintain this feature in maintained architectures, but
1108 	 * we keep the API for backward compatiblity. Currently the I and D
1109 	 * operations are exactly the same and not distinguished in debuggers.
1110 	 */
1111 	case PT_WRITE_I:
1112 	case PT_WRITE_D:
1113 		write = 1;
1114 		tmp = data;
1115 		/* FALLTHROUGH */
1116 	case PT_READ_I:
1117 	case PT_READ_D:
1118 		piod.piod_addr = &tmp;
1119 		piod.piod_len = sizeof(tmp);
1120 		piod.piod_offs = addr;
1121 		piod.piod_op = write ? PIOD_WRITE_D : PIOD_READ_D;
1122 		if ((error = ptrace_doio(l, t, lt, &piod, addr, true)) != 0)
1123 			break;
1124 		/*
1125 		 * For legacy reasons we treat here two results as success:
1126 		 *  - incomplete transfer  piod.piod_len < sizeof(tmp)
1127 		 *  - no transfer          piod.piod_len == 0
1128 		 *
1129 		 * This means that there is no way to determine whether
1130 		 * transfer operation was performed in PT_WRITE and PT_READ
1131 		 * calls.
1132 		 */
1133 		if (!write)
1134 			*retval = tmp;
1135 		break;
1136 
1137 	case PT_IO:
1138 		if ((error = ptm->ptm_copyin_piod(&piod, addr, data)) != 0)
1139 			break;
1140 		if (piod.piod_len < 1) {
1141 			error = EINVAL;
1142 			break;
1143 		}
1144 		if ((error = ptrace_doio(l, t, lt, &piod, addr, false)) != 0)
1145 			break;
1146 		/*
1147 		 * For legacy reasons we treat here two results as success:
1148 		 *  - incomplete transfer  piod.piod_len < sizeof(tmp)
1149 		 *  - no transfer          piod.piod_len == 0
1150 		 */
1151 		error = ptm->ptm_copyout_piod(&piod, addr, data);
1152 		break;
1153 
1154 	case PT_DUMPCORE:
1155 		error = ptrace_dumpcore(lt, addr, data);
1156 		break;
1157 
1158 #ifdef PT_STEP
1159 	case PT_STEP:
1160 		/*
1161 		 * From the 4.4BSD PRM:
1162 		 * "Execution continues as in request PT_CONTINUE; however
1163 		 * as soon as possible after execution of at least one
1164 		 * instruction, execution stops again. [ ... ]"
1165 		 */
1166 #endif
1167 	case PT_CONTINUE:
1168 	case PT_SYSCALL:
1169 	case PT_DETACH:
1170 		if (req == PT_SYSCALL) {
1171 			if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
1172 				SET(t->p_slflag, PSL_SYSCALL);
1173 #ifdef __HAVE_SYSCALL_INTERN
1174 				(*t->p_emul->e_syscall_intern)(t);
1175 #endif
1176 			}
1177 		} else {
1178 			if (ISSET(t->p_slflag, PSL_SYSCALL)) {
1179 				CLR(t->p_slflag, PSL_SYSCALL);
1180 #ifdef __HAVE_SYSCALL_INTERN
1181 				(*t->p_emul->e_syscall_intern)(t);
1182 #endif
1183 			}
1184 		}
1185 		t->p_trace_enabled = trace_is_enabled(t);
1186 
1187 		/*
1188 		 * Pick up the LWPID, if supplied.  There are two cases:
1189 		 * data < 0 : step or continue single thread, lwp = -data
1190 		 * data > 0 in PT_STEP : step this thread, continue others
1191 		 * For operations other than PT_STEP, data > 0 means
1192 		 * data is the signo to deliver to the process.
1193 		 */
1194 		tmp = data;
1195 		if (tmp >= 0) {
1196 #ifdef PT_STEP
1197 			if (req == PT_STEP)
1198 				signo = 0;
1199 			else
1200 #endif
1201 			{
1202 				signo = tmp;
1203 				tmp = 0;	/* don't search for LWP */
1204 			}
1205 		} else if (tmp == INT_MIN) {
1206 			error = ESRCH;
1207 			break;
1208 		} else {
1209 			tmp = -tmp;
1210 		}
1211 
1212 		if (tmp > 0) {
1213 			if (req == PT_DETACH) {
1214 				error = EINVAL;
1215 				break;
1216 			}
1217 			lwp_delref2 (lt);
1218 			lt = lwp_find(t, tmp);
1219 			if (lt == NULL) {
1220 				error = ESRCH;
1221 				break;
1222 			}
1223 			lwp_addref(lt);
1224 			resume_all = 0;
1225 			signo = 0;
1226 		}
1227 
1228 		/*
1229 		 * From the 4.4BSD PRM:
1230 		 * "The data argument is taken as a signal number and the
1231 		 * child's execution continues at location addr as if it
1232 		 * incurred that signal.  Normally the signal number will
1233 		 * be either 0 to indicate that the signal that caused the
1234 		 * stop should be ignored, or that value fetched out of
1235 		 * the process's image indicating which signal caused
1236 		 * the stop.  If addr is (int *)1 then execution continues
1237 		 * from where it stopped."
1238 		 */
1239 
1240 		/* Check that the data is a valid signal number or zero. */
1241 		if (signo < 0 || signo >= NSIG) {
1242 			error = EINVAL;
1243 			break;
1244 		}
1245 
1246 		/* Prevent process deadlock */
1247 		if (resume_all) {
1248 #ifdef PT_STEP
1249 			if (req == PT_STEP) {
1250 				if (lt->l_flag &
1251 				    (LW_WSUSPEND | LW_DBGSUSPEND)) {
1252 					error = EDEADLK;
1253 					break;
1254 				}
1255 			} else
1256 #endif
1257 			{
1258 				error = EDEADLK;
1259 				LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1260 					if ((lt2->l_flag &
1261 					    (LW_WSUSPEND | LW_DBGSUSPEND)) == 0
1262 					    ) {
1263 						error = 0;
1264 						break;
1265 					}
1266 				}
1267 				if (error != 0)
1268 					break;
1269 			}
1270 		} else {
1271 			if (lt->l_flag & (LW_WSUSPEND | LW_DBGSUSPEND)) {
1272 				error = EDEADLK;
1273 				break;
1274 			}
1275 		}
1276 
1277 		/*
1278 		 * Reject setting program counter to 0x0 if VA0 is disabled.
1279 		 *
1280 		 * Not all kernels implement this feature to set Program
1281 		 * Counter in one go in PT_CONTINUE and similar operations.
1282 		 * This causes portability issues as passing address 0x0
1283 		 * on these kernels is no-operation, but can cause failure
1284 		 * in most cases on NetBSD.
1285 		 */
1286 		if (user_va0_disable && addr == 0) {
1287 			error = EINVAL;
1288 			break;
1289 		}
1290 
1291 		/* If the address parameter is not (int *)1, set the pc. */
1292 		if ((int *)addr != (int *)1) {
1293 			error = process_set_pc(lt, addr);
1294 			if (error != 0)
1295 				break;
1296 		}
1297 #ifdef PT_STEP
1298 		/*
1299 		 * Arrange for a single-step, if that's requested and possible.
1300 		 * More precisely, set the single step status as requested for
1301 		 * the requested thread, and clear it for other threads.
1302 		 */
1303 		LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1304 			if (ISSET(lt2->l_pflag, LP_SINGLESTEP)) {
1305 				lwp_lock(lt2);
1306 				process_sstep(lt2, 1);
1307 				lwp_unlock(lt2);
1308 			} else if (lt != lt2) {
1309 				lwp_lock(lt2);
1310 				process_sstep(lt2, 0);
1311 				lwp_unlock(lt2);
1312 			}
1313 		}
1314 		error = process_sstep(lt,
1315 		    ISSET(lt->l_pflag, LP_SINGLESTEP) || req == PT_STEP);
1316 		if (error)
1317 			break;
1318 #endif
1319 		if (req == PT_DETACH) {
1320 			CLR(t->p_slflag, PSL_TRACED|PSL_SYSCALL);
1321 
1322 			/* give process back to original parent or init */
1323 			if (t->p_opptr != t->p_pptr) {
1324 				struct proc *pp = t->p_opptr;
1325 				proc_reparent(t, pp ? pp : initproc);
1326 			}
1327 
1328 			/* not being traced any more */
1329 			t->p_opptr = NULL;
1330 
1331 			/* clear single step */
1332 			LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
1333 				CLR(lt2->l_pflag, LP_SINGLESTEP);
1334 			}
1335 			CLR(lt->l_pflag, LP_SINGLESTEP);
1336 		}
1337 	sendsig:
1338 		error = ptrace_sendsig(l, req, t, lt, signo, resume_all);
1339 		break;
1340 
1341 	case PT_SYSCALLEMU:
1342 		if (!ISSET(t->p_slflag, PSL_SYSCALL) || t->p_stat != SSTOP) {
1343 			error = EINVAL;
1344 			break;
1345 		}
1346 		SET(t->p_slflag, PSL_SYSCALLEMU);
1347 		break;
1348 
1349 #ifdef PT_STEP
1350 	case PT_SETSTEP:
1351 		write = 1;
1352 
1353 		/* FALLTHROUGH */
1354 	case PT_CLEARSTEP:
1355 		/* write = 0 done above. */
1356 		if ((error = ptrace_update_lwp(t, &lt, data)) != 0)
1357 			break;
1358 
1359 		if (write)
1360 			SET(lt->l_pflag, LP_SINGLESTEP);
1361 		else
1362 			CLR(lt->l_pflag, LP_SINGLESTEP);
1363 		break;
1364 #endif
1365 
1366 	case PT_KILL:
1367 		/* just send the process a KILL signal. */
1368 		signo = SIGKILL;
1369 		goto sendsig;	/* in PT_CONTINUE, above. */
1370 
1371 	case PT_STOP:
1372 		/* just send the process a STOP signal. */
1373 		signo = SIGSTOP;
1374 		goto sendsig;	/* in PT_CONTINUE, above. */
1375 
1376 	case PT_ATTACH:
1377 		/*
1378 		 * Go ahead and set the trace flag.
1379 		 * Save the old parent (it's reset in
1380 		 *   _DETACH, and also in kern_exit.c:wait4()
1381 		 * Reparent the process so that the tracing
1382 		 *   proc gets to see all the action.
1383 		 * Stop the target.
1384 		 */
1385 		proc_changeparent(t, p);
1386 		signo = SIGSTOP;
1387 		goto sendsig;
1388 
1389 	case PT_GET_EVENT_MASK:
1390 		error = ptrace_get_event_mask(t, addr, data);
1391 		break;
1392 
1393 	case PT_SET_EVENT_MASK:
1394 		error = ptrace_set_event_mask(t, addr, data);
1395 		break;
1396 
1397 	case PT_GET_PROCESS_STATE:
1398 		error = ptrace_get_process_state(t, addr, data);
1399 		break;
1400 
1401 	case PT_LWPINFO:
1402 		error = ptrace_lwpinfo(t, &lt, addr, data);
1403 		break;
1404 
1405 	case PT_SET_SIGINFO:
1406 		error = ptrace_set_siginfo(t, &lt, ptm, addr, data);
1407 		break;
1408 
1409 	case PT_GET_SIGINFO:
1410 		error = ptrace_get_siginfo(t, ptm, addr, data);
1411 		break;
1412 
1413 	case PT_RESUME:
1414 	case PT_SUSPEND:
1415 		error = ptrace_startstop(t, &lt, req, addr, data);
1416 		break;
1417 
1418 #ifdef PT_REGISTERS
1419 	case_PT_SETREGS
1420 	case_PT_GETREGS
1421 	case_PT_SETFPREGS
1422 	case_PT_GETFPREGS
1423 	case_PT_SETDBREGS
1424 	case_PT_GETDBREGS
1425 		error = ptrace_regs(l, &lt, req, ptm, addr, data);
1426 		break;
1427 #endif
1428 
1429 #ifdef __HAVE_PTRACE_MACHDEP
1430 	PTRACE_MACHDEP_REQUEST_CASES
1431 		error = ptrace_machdep_dorequest(l, lt, req, addr, data);
1432 		break;
1433 #endif
1434 	}
1435 
1436 out:
1437 	if (pheld) {
1438 		mutex_exit(t->p_lock);
1439 		mutex_exit(proc_lock);
1440 	}
1441 	if (lt != NULL)
1442 		lwp_delref(lt);
1443 	if (locked)
1444 		rw_exit(&t->p_reflock);
1445 
1446 	return error;
1447 }
1448 
1449 typedef int (*regrfunc_t)(struct lwp *, void *, size_t *);
1450 typedef int (*regwfunc_t)(struct lwp *, void *, size_t);
1451 
1452 #ifdef PT_REGISTERS
1453 static int
1454 proc_regio(struct lwp *l, struct uio *uio, size_t ks, regrfunc_t r,
1455     regwfunc_t w)
1456 {
1457 	char buf[1024];
1458 	int error;
1459 	char *kv;
1460 	size_t kl;
1461 
1462 	if (ks > sizeof(buf))
1463 		return E2BIG;
1464 
1465 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)ks)
1466 		return EINVAL;
1467 
1468 	kv = buf + uio->uio_offset;
1469 	kl = ks - uio->uio_offset;
1470 
1471 	if (kl > uio->uio_resid)
1472 		kl = uio->uio_resid;
1473 
1474 	error = (*r)(l, buf, &ks);
1475 	if (error == 0)
1476 		error = uiomove(kv, kl, uio);
1477 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1478 		if (l->l_stat != LSSTOP)
1479 			error = EBUSY;
1480 		else
1481 			error = (*w)(l, buf, ks);
1482 	}
1483 
1484 	uio->uio_offset = 0;
1485 	return error;
1486 }
1487 #endif
1488 
1489 int
1490 process_doregs(struct lwp *curl /*tracer*/,
1491     struct lwp *l /*traced*/,
1492     struct uio *uio)
1493 {
1494 #if defined(PT_GETREGS) || defined(PT_SETREGS)
1495 	size_t s;
1496 	regrfunc_t r;
1497 	regwfunc_t w;
1498 
1499 #ifdef COMPAT_NETBSD32
1500 	const bool pk32 = (curl->l_proc->p_flag & PK_32) != 0;
1501 
1502 	if (__predict_false(pk32)) {
1503 		if ((l->l_proc->p_flag & PK_32) == 0) {
1504 			// 32 bit tracer can't trace 64 bit process
1505 			return EINVAL;
1506 		}
1507 		s = sizeof(process_reg32);
1508 		r = __FPTRCAST(regrfunc_t, process_read_regs32);
1509 		w = __FPTRCAST(regwfunc_t, process_write_regs32);
1510 	} else
1511 #endif
1512 	{
1513 		s = sizeof(struct reg);
1514 		r = __FPTRCAST(regrfunc_t, process_read_regs);
1515 		w = __FPTRCAST(regwfunc_t, process_write_regs);
1516 	}
1517 	return proc_regio(l, uio, s, r, w);
1518 #else
1519 	return EINVAL;
1520 #endif
1521 }
1522 
1523 int
1524 process_validregs(struct lwp *l)
1525 {
1526 
1527 #if defined(PT_SETREGS) || defined(PT_GETREGS)
1528 	return (l->l_flag & LW_SYSTEM) == 0;
1529 #else
1530 	return 0;
1531 #endif
1532 }
1533 
1534 int
1535 process_dofpregs(struct lwp *curl /*tracer*/,
1536     struct lwp *l /*traced*/,
1537     struct uio *uio)
1538 {
1539 #if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
1540 	size_t s;
1541 	regrfunc_t r;
1542 	regwfunc_t w;
1543 
1544 #ifdef COMPAT_NETBSD32
1545 	const bool pk32 = (curl->l_proc->p_flag & PK_32) != 0;
1546 
1547 	if (__predict_false(pk32)) {
1548 		if ((l->l_proc->p_flag & PK_32) == 0) {
1549 			// 32 bit tracer can't trace 64 bit process
1550 			return EINVAL;
1551 		}
1552 		s = sizeof(process_fpreg32);
1553 		r = (regrfunc_t)process_read_fpregs32;
1554 		w = (regwfunc_t)process_write_fpregs32;
1555 	} else
1556 #endif
1557 	{
1558 		s = sizeof(struct fpreg);
1559 		r = (regrfunc_t)process_read_fpregs;
1560 		w = (regwfunc_t)process_write_fpregs;
1561 	}
1562 	return proc_regio(l, uio, s, r, w);
1563 #else
1564 	return EINVAL;
1565 #endif
1566 }
1567 
1568 int
1569 process_validfpregs(struct lwp *l)
1570 {
1571 
1572 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
1573 	return (l->l_flag & LW_SYSTEM) == 0;
1574 #else
1575 	return 0;
1576 #endif
1577 }
1578 
1579 int
1580 process_dodbregs(struct lwp *curl /*tracer*/,
1581     struct lwp *l /*traced*/,
1582     struct uio *uio)
1583 {
1584 #if defined(PT_GETDBREGS) || defined(PT_SETDBREGS)
1585 	size_t s;
1586 	regrfunc_t r;
1587 	regwfunc_t w;
1588 
1589 #ifdef COMPAT_NETBSD32
1590 	const bool pk32 = (curl->l_proc->p_flag & PK_32) != 0;
1591 
1592 	if (__predict_false(pk32)) {
1593 		if ((l->l_proc->p_flag & PK_32) == 0) {
1594 			// 32 bit tracer can't trace 64 bit process
1595 			return EINVAL;
1596 		}
1597 		s = sizeof(process_dbreg32);
1598 		r = (regrfunc_t)process_read_dbregs32;
1599 		w = (regwfunc_t)process_write_dbregs32;
1600 	} else
1601 #endif
1602 	{
1603 		s = sizeof(struct dbreg);
1604 		r = (regrfunc_t)process_read_dbregs;
1605 		w = (regwfunc_t)process_write_dbregs;
1606 	}
1607 	return proc_regio(l, uio, s, r, w);
1608 #else
1609 	return EINVAL;
1610 #endif
1611 }
1612 
1613 int
1614 process_validdbregs(struct lwp *l)
1615 {
1616 
1617 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
1618 	return (l->l_flag & LW_SYSTEM) == 0;
1619 #else
1620 	return 0;
1621 #endif
1622 }
1623 
1624 static int
1625 process_auxv_offset(struct proc *p, struct uio *uio)
1626 {
1627 	struct ps_strings pss;
1628 	int error;
1629 	off_t off = (off_t)p->p_psstrp;
1630 
1631 	if ((error = copyin_psstrings(p, &pss)) != 0)
1632 		return error;
1633 
1634 	if (pss.ps_envstr == NULL)
1635 		return EIO;
1636 
1637 	uio->uio_offset += (off_t)(vaddr_t)(pss.ps_envstr + pss.ps_nenvstr + 1);
1638 #ifdef __MACHINE_STACK_GROWS_UP
1639 	if (uio->uio_offset < off)
1640 		return EIO;
1641 #else
1642 	if (uio->uio_offset > off)
1643 		return EIO;
1644 	if ((uio->uio_offset + uio->uio_resid) > off)
1645 		uio->uio_resid = off - uio->uio_offset;
1646 #endif
1647 	return 0;
1648 }
1649 #endif /* PTRACE */
1650 
1651 MODULE(MODULE_CLASS_EXEC, ptrace_common, NULL);
1652 
1653 static int
1654 ptrace_common_modcmd(modcmd_t cmd, void *arg)
1655 {
1656         int error;
1657 
1658         switch (cmd) {
1659         case MODULE_CMD_INIT:
1660                 error = ptrace_init();
1661                 break;
1662         case MODULE_CMD_FINI:
1663                 error = ptrace_fini();
1664                 break;
1665         default:
1666 		ptrace_hooks();
1667                 error = ENOTTY;
1668                 break;
1669         }
1670         return error;
1671 }
1672