xref: /netbsd-src/sys/kern/sys_ptrace_common.c (revision 7c192b2a5e1093666e67801684f930ef49b3b363)
1 /*	$NetBSD: sys_ptrace_common.c,v 1.22 2017/05/03 15:53:31 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 1.22 2017/05/03 15:53:31 kamil Exp $");
122 
123 #ifdef _KERNEL_OPT
124 #include "opt_ptrace.h"
125 #include "opt_ktrace.h"
126 #include "opt_pax.h"
127 #endif
128 
129 #include <sys/param.h>
130 #include <sys/systm.h>
131 #include <sys/proc.h>
132 #include <sys/errno.h>
133 #include <sys/exec.h>
134 #include <sys/pax.h>
135 #include <sys/ptrace.h>
136 #include <sys/uio.h>
137 #include <sys/ras.h>
138 #include <sys/kmem.h>
139 #include <sys/kauth.h>
140 #include <sys/mount.h>
141 #include <sys/syscallargs.h>
142 #include <sys/module.h>
143 #include <sys/condvar.h>
144 #include <sys/mutex.h>
145 
146 #include <uvm/uvm_extern.h>
147 
148 #include <machine/reg.h>
149 
150 #ifdef PTRACE
151 
152 # ifdef DEBUG
153 #  define DPRINTF(a) uprintf a
154 # else
155 #  define DPRINTF(a)
156 # endif
157 
158 static kauth_listener_t ptrace_listener;
159 static int process_auxv_offset(struct proc *, struct uio *);
160 
161 #if 0
162 static int ptrace_cbref;
163 static kmutex_t ptrace_mtx;
164 static kcondvar_t ptrace_cv;
165 #endif
166 
167 static int
168 ptrace_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
169     void *arg0, void *arg1, void *arg2, void *arg3)
170 {
171 	struct proc *p;
172 	int result;
173 
174 	result = KAUTH_RESULT_DEFER;
175 	p = arg0;
176 
177 #if 0
178 	mutex_enter(&ptrace_mtx);
179 	ptrace_cbref++;
180 	mutex_exit(&ptrace_mtx);
181 #endif
182 	if (action != KAUTH_PROCESS_PTRACE)
183 		goto out;
184 
185 	switch ((u_long)arg1) {
186 	case PT_TRACE_ME:
187 	case PT_ATTACH:
188 	case PT_WRITE_I:
189 	case PT_WRITE_D:
190 	case PT_READ_I:
191 	case PT_READ_D:
192 	case PT_IO:
193 #ifdef PT_GETREGS
194 	case PT_GETREGS:
195 #endif
196 #ifdef PT_SETREGS
197 	case PT_SETREGS:
198 #endif
199 #ifdef PT_GETFPREGS
200 	case PT_GETFPREGS:
201 #endif
202 #ifdef PT_SETFPREGS
203 	case PT_SETFPREGS:
204 #endif
205 #ifdef PT_GETDBREGS
206 	case PT_GETDBREGS:
207 #endif
208 #ifdef PT_SETDBREGS
209 	case PT_SETDBREGS:
210 #endif
211 	case PT_SET_EVENT_MASK:
212 	case PT_GET_EVENT_MASK:
213 	case PT_GET_PROCESS_STATE:
214 	case PT_SET_SIGINFO:
215 	case PT_GET_SIGINFO:
216 	case PT_SET_SIGMASK:
217 	case PT_GET_SIGMASK:
218 #ifdef __HAVE_PTRACE_MACHDEP
219 	PTRACE_MACHDEP_REQUEST_CASES
220 #endif
221 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
222 		    ISSET(p->p_flag, PK_SUGID)) {
223 			break;
224 		}
225 
226 		result = KAUTH_RESULT_ALLOW;
227 
228 	break;
229 
230 #ifdef PT_STEP
231 	case PT_STEP:
232 	case PT_SETSTEP:
233 	case PT_CLEARSTEP:
234 #endif
235 	case PT_CONTINUE:
236 	case PT_KILL:
237 	case PT_DETACH:
238 	case PT_LWPINFO:
239 	case PT_SYSCALL:
240 	case PT_SYSCALLEMU:
241 	case PT_DUMPCORE:
242 	case PT_RESUME:
243 	case PT_SUSPEND:
244 		result = KAUTH_RESULT_ALLOW;
245 		break;
246 
247 	default:
248 		break;
249 	}
250 
251  out:
252 #if 0
253 	mutex_enter(&ptrace_mtx);
254 	if (--ptrace_cbref == 0)
255 		cv_broadcast(&ptrace_cv);
256 	mutex_exit(&ptrace_mtx);
257 #endif
258 
259 	return result;
260 }
261 
262 int
263 ptrace_init(void)
264 {
265 
266 #if 0
267 	mutex_init(&ptrace_mtx, MUTEX_DEFAULT, IPL_NONE);
268 	cv_init(&ptrace_cv, "ptracecb");
269 	ptrace_cbref = 0;
270 #endif
271 	ptrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
272 	    ptrace_listener_cb, NULL);
273 	return 0;
274 }
275 
276 int
277 ptrace_fini(void)
278 {
279 
280 	kauth_unlisten_scope(ptrace_listener);
281 
282 #if 0
283 	/* Make sure no-one is executing our kauth listener */
284 
285 	mutex_enter(&ptrace_mtx);
286 	while (ptrace_cbref != 0)
287 		cv_wait(&ptrace_cv, &ptrace_mtx);
288 	mutex_exit(&ptrace_mtx);
289 	mutex_destroy(&ptrace_mtx);
290 	cv_destroy(&ptrace_cv);
291 #endif
292 
293 	return 0;
294 }
295 
296 int
297 do_ptrace(struct ptrace_methods *ptm, struct lwp *l, int req, pid_t pid,
298     void *addr, int data, register_t *retval)
299 {
300 	struct proc *p = l->l_proc;
301 	struct lwp *lt;
302 	struct lwp *lt2;
303 	struct proc *t;				/* target process */
304 	struct uio uio;
305 	struct iovec iov;
306 	struct ptrace_io_desc piod;
307 	struct ptrace_event pe;
308 	struct ptrace_state ps;
309 	struct ptrace_lwpinfo pl;
310 	struct ptrace_siginfo psi;
311 	struct vmspace *vm;
312 	int error, write, tmp, pheld;
313 	int signo = 0;
314 	int resume_all;
315 	ksiginfo_t ksi;
316 	char *path;
317 	int len = 0;
318 	error = 0;
319 
320 	/*
321 	 * If attaching or detaching, we need to get a write hold on the
322 	 * proclist lock so that we can re-parent the target process.
323 	 */
324 	mutex_enter(proc_lock);
325 
326 	/* "A foolish consistency..." XXX */
327 	if (req == PT_TRACE_ME) {
328 		t = p;
329 		mutex_enter(t->p_lock);
330 	} else {
331 		/* Find the process we're supposed to be operating on. */
332 		t = proc_find(pid);
333 		if (t == NULL) {
334 			mutex_exit(proc_lock);
335 			return ESRCH;
336 		}
337 
338 		/* XXX-elad */
339 		mutex_enter(t->p_lock);
340 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
341 		    t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
342 		if (error) {
343 			mutex_exit(proc_lock);
344 			mutex_exit(t->p_lock);
345 			return ESRCH;
346 		}
347 	}
348 
349 	/*
350 	 * Grab a reference on the process to prevent it from execing or
351 	 * exiting.
352 	 */
353 	if (!rw_tryenter(&t->p_reflock, RW_READER)) {
354 		mutex_exit(proc_lock);
355 		mutex_exit(t->p_lock);
356 		return EBUSY;
357 	}
358 
359 	/* Make sure we can operate on it. */
360 	switch (req) {
361 	case  PT_TRACE_ME:
362 		/* Saying that you're being traced is always legal. */
363 		break;
364 
365 	case  PT_ATTACH:
366 		/*
367 		 * You can't attach to a process if:
368 		 *	(1) it's the process that's doing the attaching,
369 		 */
370 		if (t->p_pid == p->p_pid) {
371 			error = EINVAL;
372 			break;
373 		}
374 
375 		/*
376 		 *  (2) it's a system process
377 		 */
378 		if (t->p_flag & PK_SYSTEM) {
379 			error = EPERM;
380 			break;
381 		}
382 
383 		/*
384 		 *	(3) it's already being traced, or
385 		 */
386 		if (ISSET(t->p_slflag, PSL_TRACED)) {
387 			error = EBUSY;
388 			break;
389 		}
390 
391 		/*
392 		 * 	(4) the tracer is chrooted, and its root directory is
393 		 * 	    not at or above the root directory of the tracee
394 		 */
395 		mutex_exit(t->p_lock);	/* XXXSMP */
396 		tmp = proc_isunder(t, l);
397 		mutex_enter(t->p_lock);	/* XXXSMP */
398 		if (!tmp) {
399 			error = EPERM;
400 			break;
401 		}
402 		break;
403 
404 	case  PT_READ_I:
405 	case  PT_READ_D:
406 	case  PT_WRITE_I:
407 	case  PT_WRITE_D:
408 	case  PT_IO:
409 	case  PT_SET_SIGINFO:
410 	case  PT_GET_SIGINFO:
411 	case  PT_SET_SIGMASK:
412 	case  PT_GET_SIGMASK:
413 #ifdef PT_GETREGS
414 	case  PT_GETREGS:
415 #endif
416 #ifdef PT_SETREGS
417 	case  PT_SETREGS:
418 #endif
419 #ifdef PT_GETFPREGS
420 	case  PT_GETFPREGS:
421 #endif
422 #ifdef PT_SETFPREGS
423 	case  PT_SETFPREGS:
424 #endif
425 #ifdef PT_GETDBREGS
426 	case  PT_GETDBREGS:
427 #endif
428 #ifdef PT_SETDBREGS
429 	case  PT_SETDBREGS:
430 #endif
431 #ifdef __HAVE_PTRACE_MACHDEP
432 	PTRACE_MACHDEP_REQUEST_CASES
433 #endif
434 		/*
435 		 * You can't read/write the memory or registers of a process
436 		 * if the tracer is chrooted, and its root directory is not at
437 		 * or above the root directory of the tracee.
438 		 */
439 		mutex_exit(t->p_lock);	/* XXXSMP */
440 		tmp = proc_isunder(t, l);
441 		mutex_enter(t->p_lock);	/* XXXSMP */
442 		if (!tmp) {
443 			error = EPERM;
444 			break;
445 		}
446 		/*FALLTHROUGH*/
447 
448 	case  PT_CONTINUE:
449 	case  PT_KILL:
450 	case  PT_DETACH:
451 	case  PT_LWPINFO:
452 	case  PT_SYSCALL:
453 	case  PT_SYSCALLEMU:
454 	case  PT_DUMPCORE:
455 #ifdef PT_STEP
456 	case  PT_STEP:
457 	case  PT_SETSTEP:
458 	case  PT_CLEARSTEP:
459 #endif
460 	case  PT_SET_EVENT_MASK:
461 	case  PT_GET_EVENT_MASK:
462 	case  PT_GET_PROCESS_STATE:
463 	case  PT_RESUME:
464 	case  PT_SUSPEND:
465 		/*
466 		 * You can't do what you want to the process if:
467 		 *	(1) It's not being traced at all,
468 		 */
469 		if (!ISSET(t->p_slflag, PSL_TRACED)) {
470 			error = EPERM;
471 			break;
472 		}
473 
474 		/*
475 		 *	(2) it's being traced by procfs (which has
476 		 *	    different signal delivery semantics),
477 		 */
478 		if (ISSET(t->p_slflag, PSL_FSTRACE)) {
479 			DPRINTF(("file system traced\n"));
480 			error = EBUSY;
481 			break;
482 		}
483 
484 		/*
485 		 *	(3) it's not being traced by _you_, or
486 		 */
487 		if (t->p_pptr != p) {
488 			DPRINTF(("parent %d != %d\n", t->p_pptr->p_pid,
489 			    p->p_pid));
490 			error = EBUSY;
491 			break;
492 		}
493 
494 		/*
495 		 *	(4) it's not currently stopped.
496 		 */
497 		if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) {
498 			DPRINTF(("stat %d flag %d\n", t->p_stat,
499 			    !t->p_waited));
500 			error = EBUSY;
501 			break;
502 		}
503 		break;
504 
505 	default:			/* It was not a legal request. */
506 		error = EINVAL;
507 		break;
508 	}
509 
510 	if (error == 0) {
511 		error = kauth_authorize_process(l->l_cred,
512 		    KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req),
513 		    NULL, NULL);
514 	}
515 	if (error == 0) {
516 		lt = lwp_find_first(t);
517 		if (lt == NULL)
518 			error = ESRCH;
519 	}
520 
521 	if (error != 0) {
522 		mutex_exit(proc_lock);
523 		mutex_exit(t->p_lock);
524 		rw_exit(&t->p_reflock);
525 		return error;
526 	}
527 
528 	/* Do single-step fixup if needed. */
529 	FIX_SSTEP(t);
530 	KASSERT(lt != NULL);
531 	lwp_addref(lt);
532 
533 	/*
534 	 * Which locks do we need held? XXX Ugly.
535 	 */
536 	switch (req) {
537 #ifdef PT_STEP
538 	case PT_STEP:
539 #endif
540 	case PT_CONTINUE:
541 	case PT_DETACH:
542 	case PT_KILL:
543 	case PT_SYSCALL:
544 	case PT_SYSCALLEMU:
545 	case PT_ATTACH:
546 	case PT_TRACE_ME:
547 		pheld = 1;
548 		break;
549 	default:
550 		mutex_exit(proc_lock);
551 		mutex_exit(t->p_lock);
552 		pheld = 0;
553 		break;
554 	}
555 
556 	/* Now do the operation. */
557 	write = 0;
558 	*retval = 0;
559 	tmp = 0;
560 	resume_all = 1;
561 
562 	switch (req) {
563 	case  PT_TRACE_ME:
564 		/* Just set the trace flag. */
565 		SET(t->p_slflag, PSL_TRACED);
566 		t->p_opptr = t->p_pptr;
567 		break;
568 
569 	case  PT_WRITE_I:		/* XXX no separate I and D spaces */
570 	case  PT_WRITE_D:
571 #if defined(__HAVE_RAS)
572 		/*
573 		 * Can't write to a RAS
574 		 */
575 		if (ras_lookup(t, addr) != (void *)-1) {
576 			error = EACCES;
577 			break;
578 		}
579 #endif
580 		write = 1;
581 		tmp = data;
582 		/* FALLTHROUGH */
583 
584 	case  PT_READ_I:		/* XXX no separate I and D spaces */
585 	case  PT_READ_D:
586 		/* write = 0 done above. */
587 		iov.iov_base = (void *)&tmp;
588 		iov.iov_len = sizeof(tmp);
589 		uio.uio_iov = &iov;
590 		uio.uio_iovcnt = 1;
591 		uio.uio_offset = (off_t)(unsigned long)addr;
592 		uio.uio_resid = sizeof(tmp);
593 		uio.uio_rw = write ? UIO_WRITE : UIO_READ;
594 		UIO_SETUP_SYSSPACE(&uio);
595 
596 		error = process_domem(l, lt, &uio);
597 		if (!write)
598 			*retval = tmp;
599 		break;
600 
601 	case  PT_IO:
602 		error = ptm->ptm_copyinpiod(&piod, addr);
603 		if (error)
604 			break;
605 
606 		iov.iov_base = piod.piod_addr;
607 		iov.iov_len = piod.piod_len;
608 		uio.uio_iov = &iov;
609 		uio.uio_iovcnt = 1;
610 		uio.uio_offset = (off_t)(unsigned long)piod.piod_offs;
611 		uio.uio_resid = piod.piod_len;
612 
613 		switch (piod.piod_op) {
614 		case PIOD_READ_D:
615 		case PIOD_READ_I:
616 			uio.uio_rw = UIO_READ;
617 			break;
618 		case PIOD_WRITE_D:
619 		case PIOD_WRITE_I:
620 			/*
621 			 * Can't write to a RAS
622 			 */
623 			if (ras_lookup(t, addr) != (void *)-1) {
624 				return EACCES;
625 			}
626 			uio.uio_rw = UIO_WRITE;
627 			break;
628 		case PIOD_READ_AUXV:
629 			req = PT_READ_D;
630 			uio.uio_rw = UIO_READ;
631 			tmp = t->p_execsw->es_arglen;
632 			if (uio.uio_offset > tmp)
633 				return EIO;
634 			if (uio.uio_resid > tmp - uio.uio_offset)
635 				uio.uio_resid = tmp - uio.uio_offset;
636 			piod.piod_len = iov.iov_len = uio.uio_resid;
637 			error = process_auxv_offset(t, &uio);
638 			break;
639 		default:
640 			error = EINVAL;
641 			break;
642 		}
643 		if (error)
644 			break;
645 		error = proc_vmspace_getref(l->l_proc, &vm);
646 		if (error)
647 			break;
648 		uio.uio_vmspace = vm;
649 
650 		error = process_domem(l, lt, &uio);
651 		piod.piod_len -= uio.uio_resid;
652 		(void) ptm->ptm_copyoutpiod(&piod, addr);
653 
654 		uvmspace_free(vm);
655 		break;
656 
657 	case  PT_DUMPCORE:
658 		if ((path = addr) != NULL) {
659 			char *dst;
660 			len = data;
661 
662 			if (len < 0 || len >= MAXPATHLEN) {
663 				error = EINVAL;
664 				break;
665 			}
666 			dst = kmem_alloc(len + 1, KM_SLEEP);
667 			if ((error = copyin(path, dst, len)) != 0) {
668 				kmem_free(dst, len + 1);
669 				break;
670 			}
671 			path = dst;
672 			path[len] = '\0';
673 		}
674 		error = (*coredump_vec)(lt, path);
675 		if (path)
676 			kmem_free(path, len + 1);
677 		break;
678 
679 #ifdef PT_STEP
680 	case  PT_STEP:
681 		/*
682 		 * From the 4.4BSD PRM:
683 		 * "Execution continues as in request PT_CONTINUE; however
684 		 * as soon as possible after execution of at least one
685 		 * instruction, execution stops again. [ ... ]"
686 		 */
687 #endif
688 	case  PT_CONTINUE:
689 	case  PT_SYSCALL:
690 	case  PT_DETACH:
691 		if (req == PT_SYSCALL) {
692 			if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
693 				SET(t->p_slflag, PSL_SYSCALL);
694 #ifdef __HAVE_SYSCALL_INTERN
695 				(*t->p_emul->e_syscall_intern)(t);
696 #endif
697 			}
698 		} else {
699 			if (ISSET(t->p_slflag, PSL_SYSCALL)) {
700 				CLR(t->p_slflag, PSL_SYSCALL);
701 #ifdef __HAVE_SYSCALL_INTERN
702 				(*t->p_emul->e_syscall_intern)(t);
703 #endif
704 			}
705 		}
706 		t->p_trace_enabled = trace_is_enabled(t);
707 
708 		/*
709 		 * Pick up the LWPID, if supplied.  There are two cases:
710 		 * data < 0 : step or continue single thread, lwp = -data
711 		 * data > 0 in PT_STEP : step this thread, continue others
712 		 * For operations other than PT_STEP, data > 0 means
713 		 * data is the signo to deliver to the process.
714 		 */
715 		tmp = data;
716 		if (tmp >= 0) {
717 #ifdef PT_STEP
718 			if (req == PT_STEP)
719 				signo = 0;
720 			else
721 #endif
722 			{
723 				signo = tmp;
724 				tmp = 0;	/* don't search for LWP */
725 			}
726 		} else
727 			tmp = -tmp;
728 
729 		if (tmp > 0) {
730 			if (req == PT_DETACH) {
731 				error = EINVAL;
732 				break;
733 			}
734 			lwp_delref2 (lt);
735 			lt = lwp_find(t, tmp);
736 			if (lt == NULL) {
737 				error = ESRCH;
738 				break;
739 			}
740 			lwp_addref(lt);
741 			resume_all = 0;
742 			signo = 0;
743 		}
744 
745 		/*
746 		 * From the 4.4BSD PRM:
747 		 * "The data argument is taken as a signal number and the
748 		 * child's execution continues at location addr as if it
749 		 * incurred that signal.  Normally the signal number will
750 		 * be either 0 to indicate that the signal that caused the
751 		 * stop should be ignored, or that value fetched out of
752 		 * the process's image indicating which signal caused
753 		 * the stop.  If addr is (int *)1 then execution continues
754 		 * from where it stopped."
755 		 */
756 
757 		/* Check that the data is a valid signal number or zero. */
758 		if (signo < 0 || signo >= NSIG) {
759 			error = EINVAL;
760 			break;
761 		}
762 
763 		/* Prevent process deadlock */
764 		if (resume_all) {
765 #ifdef PT_STEP
766 			if (req == PT_STEP) {
767 				if (lt->l_flag & LW_WSUSPEND) {
768 					error = EDEADLK;
769 					break;
770 				}
771 			} else
772 #endif
773 			{
774 				error = EDEADLK;
775 				LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
776 					if ((lt2->l_flag & LW_WSUSPEND) == 0) {
777 						error = 0;
778 						break;
779 					}
780 				}
781 				if (error != 0)
782 					break;
783 			}
784 		} else {
785 			if (lt->l_flag & LW_WSUSPEND) {
786 				error = EDEADLK;
787 				break;
788 			}
789 		}
790 
791 		/* If the address parameter is not (int *)1, set the pc. */
792 		if ((int *)addr != (int *)1) {
793 			error = process_set_pc(lt, addr);
794 			if (error != 0)
795 				break;
796 		}
797 #ifdef PT_STEP
798 		/*
799 		 * Arrange for a single-step, if that's requested and possible.
800 		 * More precisely, set the single step status as requested for
801 		 * the requested thread, and clear it for other threads.
802 		 */
803 		LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
804 			if (ISSET(lt2->l_pflag, LP_SINGLESTEP)) {
805 				lwp_lock(lt2);
806 				process_sstep(lt2, 1);
807 				lwp_unlock(lt2);
808 			} else if (lt != lt2) {
809 				lwp_lock(lt2);
810 				process_sstep(lt2, 0);
811 				lwp_unlock(lt2);
812 			}
813 		}
814 		error = process_sstep(lt,
815 		    ISSET(lt->l_pflag, LP_SINGLESTEP) || req == PT_STEP);
816 		if (error)
817 			break;
818 #endif
819 		if (req == PT_DETACH) {
820 			CLR(t->p_slflag, PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL);
821 
822 			/* give process back to original parent or init */
823 			if (t->p_opptr != t->p_pptr) {
824 				struct proc *pp = t->p_opptr;
825 				proc_reparent(t, pp ? pp : initproc);
826 			}
827 
828 			/* not being traced any more */
829 			t->p_opptr = NULL;
830 
831 			/* clear single step */
832 			LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
833 				CLR(lt2->l_pflag, LP_SINGLESTEP);
834 			}
835 			CLR(lt->l_pflag, LP_SINGLESTEP);
836 		}
837 	sendsig:
838 		t->p_fpid = 0;
839 		t->p_vfpid = 0;
840 		t->p_vfpid_done = 0;
841 		t->p_lwp_created = 0;
842 		t->p_lwp_exited = 0;
843 		/* Finally, deliver the requested signal (or none). */
844 		if (t->p_stat == SSTOP) {
845 			/*
846 			 * Unstop the process.  If it needs to take a
847 			 * signal, make all efforts to ensure that at
848 			 * an LWP runs to see it.
849 			 */
850 			t->p_xsig = signo;
851 			if (resume_all)
852 				proc_unstop(t);
853 			else
854 				lwp_unstop(lt);
855 		} else if (t->p_sigctx.ps_faked) {
856 			if (signo != t->p_sigctx.ps_info._signo) {
857 				error = EINVAL;
858 				break;
859 			}
860 			t->p_sigctx.ps_faked = false;
861 			KSI_INIT_EMPTY(&ksi);
862 			ksi.ksi_info = t->p_sigctx.ps_info;
863 			ksi.ksi_lid = t->p_sigctx.ps_lwp;
864 			kpsignal2(t, &ksi);
865 		} else if (signo != 0) {
866 			KSI_INIT_EMPTY(&ksi);
867 			ksi.ksi_signo = signo;
868 			kpsignal2(t, &ksi);
869 		}
870 		break;
871 
872 	case  PT_SYSCALLEMU:
873 		if (!ISSET(t->p_slflag, PSL_SYSCALL) || t->p_stat != SSTOP) {
874 			error = EINVAL;
875 			break;
876 		}
877 		SET(t->p_slflag, PSL_SYSCALLEMU);
878 		break;
879 
880 #ifdef PT_STEP
881 	case  PT_SETSTEP:
882 		write = 1;
883 
884 	case  PT_CLEARSTEP:
885 		/* write = 0 done above. */
886 
887 		tmp = data;
888 		if (tmp != 0 && t->p_nlwps > 1) {
889 			lwp_delref(lt);
890 			mutex_enter(t->p_lock);
891 			lt = lwp_find(t, tmp);
892 			if (lt == NULL) {
893 				mutex_exit(t->p_lock);
894 				error = ESRCH;
895 				break;
896 			}
897 			lwp_addref(lt);
898 			mutex_exit(t->p_lock);
899 		}
900 
901 		if (ISSET(lt->l_flag, LW_SYSTEM))
902 			error = EINVAL;
903 		else if (write)
904 			SET(lt->l_pflag, LP_SINGLESTEP);
905 		else
906 			CLR(lt->l_pflag, LP_SINGLESTEP);
907 		break;
908 #endif
909 
910 	case  PT_KILL:
911 		/* just send the process a KILL signal. */
912 		signo = SIGKILL;
913 		goto sendsig;	/* in PT_CONTINUE, above. */
914 
915 	case  PT_ATTACH:
916 		/*
917 		 * Go ahead and set the trace flag.
918 		 * Save the old parent (it's reset in
919 		 *   _DETACH, and also in kern_exit.c:wait4()
920 		 * Reparent the process so that the tracing
921 		 *   proc gets to see all the action.
922 		 * Stop the target.
923 		 */
924 		proc_changeparent(t, p);
925 		signo = SIGSTOP;
926 		goto sendsig;
927 
928 	case  PT_GET_EVENT_MASK:
929 		if (data != sizeof(pe)) {
930 			DPRINTF(("ptrace(%d): %d != %zu\n", req,
931 			    data, sizeof(pe)));
932 			error = EINVAL;
933 			break;
934 		}
935 		memset(&pe, 0, sizeof(pe));
936 		pe.pe_set_event = ISSET(t->p_slflag, PSL_TRACEFORK) ?
937 		    PTRACE_FORK : 0;
938 		pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK) ?
939 		    PTRACE_VFORK : 0;
940 		pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACEVFORK_DONE) ?
941 		    PTRACE_VFORK_DONE : 0;
942 		pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_CREATE) ?
943 		    PTRACE_LWP_CREATE : 0;
944 		pe.pe_set_event |= ISSET(t->p_slflag, PSL_TRACELWP_EXIT) ?
945 		    PTRACE_LWP_EXIT : 0;
946 		error = copyout(&pe, addr, sizeof(pe));
947 		break;
948 
949 	case  PT_SET_EVENT_MASK:
950 		if (data != sizeof(pe)) {
951 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
952 			    sizeof(pe)));
953 			error = EINVAL;
954 			break;
955 		}
956 		if ((error = copyin(addr, &pe, sizeof(pe))) != 0)
957 			return error;
958 		if (pe.pe_set_event & PTRACE_FORK)
959 			SET(t->p_slflag, PSL_TRACEFORK);
960 		else
961 			CLR(t->p_slflag, PSL_TRACEFORK);
962 #if notyet
963 		if (pe.pe_set_event & PTRACE_VFORK)
964 			SET(t->p_slflag, PSL_TRACEVFORK);
965 		else
966 			CLR(t->p_slflag, PSL_TRACEVFORK);
967 #else
968 		if (pe.pe_set_event & PTRACE_VFORK) {
969 			error = ENOTSUP;
970 			break;
971 		}
972 #endif
973 		if (pe.pe_set_event & PTRACE_VFORK_DONE)
974 			SET(t->p_slflag, PSL_TRACEVFORK_DONE);
975 		else
976 			CLR(t->p_slflag, PSL_TRACEVFORK_DONE);
977 		if (pe.pe_set_event & PTRACE_LWP_CREATE)
978 			SET(t->p_slflag, PSL_TRACELWP_CREATE);
979 		else
980 			CLR(t->p_slflag, PSL_TRACELWP_CREATE);
981 		if (pe.pe_set_event & PTRACE_LWP_EXIT)
982 			SET(t->p_slflag, PSL_TRACELWP_EXIT);
983 		else
984 			CLR(t->p_slflag, PSL_TRACELWP_EXIT);
985 		break;
986 
987 	case  PT_GET_PROCESS_STATE:
988 		if (data != sizeof(ps)) {
989 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
990 			    sizeof(ps)));
991 			error = EINVAL;
992 			break;
993 		}
994 		memset(&ps, 0, sizeof(ps));
995 		if (t->p_fpid) {
996 			ps.pe_report_event = PTRACE_FORK;
997 			ps.pe_other_pid = t->p_fpid;
998 		} else if (t->p_vfpid) {
999 			ps.pe_report_event = PTRACE_VFORK;
1000 			ps.pe_other_pid = t->p_vfpid;
1001 		} else if (t->p_vfpid_done) {
1002 			ps.pe_report_event = PTRACE_VFORK_DONE;
1003 			ps.pe_other_pid = t->p_vfpid_done;
1004 		} else if (t->p_lwp_created) {
1005 			ps.pe_report_event = PTRACE_LWP_CREATE;
1006 			ps.pe_lwp = t->p_lwp_created;
1007 		} else if (t->p_lwp_exited) {
1008 			ps.pe_report_event = PTRACE_LWP_EXIT;
1009 			ps.pe_lwp = t->p_lwp_exited;
1010 		}
1011 		error = copyout(&ps, addr, sizeof(ps));
1012 		break;
1013 
1014 	case PT_LWPINFO:
1015 		if (data != sizeof(pl)) {
1016 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
1017 			    sizeof(pl)));
1018 			error = EINVAL;
1019 			break;
1020 		}
1021 		error = copyin(addr, &pl, sizeof(pl));
1022 		if (error)
1023 			break;
1024 		tmp = pl.pl_lwpid;
1025 		lwp_delref(lt);
1026 		mutex_enter(t->p_lock);
1027 		if (tmp == 0)
1028 			lt = lwp_find_first(t);
1029 		else {
1030 			lt = lwp_find(t, tmp);
1031 			if (lt == NULL) {
1032 				mutex_exit(t->p_lock);
1033 				error = ESRCH;
1034 				break;
1035 			}
1036 			lt = LIST_NEXT(lt, l_sibling);
1037 		}
1038 		while (lt != NULL && !lwp_alive(lt))
1039 			lt = LIST_NEXT(lt, l_sibling);
1040 		pl.pl_lwpid = 0;
1041 		pl.pl_event = 0;
1042 		if (lt) {
1043 			lwp_addref(lt);
1044 			pl.pl_lwpid = lt->l_lid;
1045 
1046 			if (lt->l_flag & LW_WSUSPEND)
1047 				pl.pl_event = PL_EVENT_SUSPENDED;
1048 			/*
1049 			 * If we match the lwp, or it was sent to every lwp,
1050 			 * we set PL_EVENT_SIGNAL.
1051 			 * XXX: ps_lwp == 0 means everyone and noone, so
1052 			 * check ps_signo too.
1053 			 */
1054 			else if (lt->l_lid == t->p_sigctx.ps_lwp
1055 			         || (t->p_sigctx.ps_lwp == 0 &&
1056 			             t->p_sigctx.ps_info._signo))
1057 				pl.pl_event = PL_EVENT_SIGNAL;
1058 		}
1059 		mutex_exit(t->p_lock);
1060 
1061 		error = copyout(&pl, addr, sizeof(pl));
1062 		break;
1063 
1064 	case  PT_SET_SIGINFO:
1065 		if (data != sizeof(psi)) {
1066 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
1067 			    sizeof(psi)));
1068 			error = EINVAL;
1069 			break;
1070 		}
1071 
1072 		error = copyin(addr, &psi, sizeof(psi));
1073 		if (error)
1074 			break;
1075 
1076 		/* Check that the data is a valid signal number or zero. */
1077 		if (psi.psi_siginfo.si_signo < 0 ||
1078 		    psi.psi_siginfo.si_signo >= NSIG) {
1079 			error = EINVAL;
1080 			break;
1081 		}
1082 
1083 		tmp = psi.psi_lwpid;
1084 		if (tmp != 0)
1085 			lwp_delref(lt);
1086 
1087 		mutex_enter(t->p_lock);
1088 
1089 		if (tmp != 0) {
1090 			lt = lwp_find(t, tmp);
1091 			if (lt == NULL) {
1092 				mutex_exit(t->p_lock);
1093 				error = ESRCH;
1094 				break;
1095 			}
1096 			lwp_addref(lt);
1097 		}
1098 
1099 		t->p_sigctx.ps_faked = true;
1100 		t->p_sigctx.ps_info = psi.psi_siginfo._info;
1101 		t->p_sigctx.ps_lwp = psi.psi_lwpid;
1102 		mutex_exit(t->p_lock);
1103 		break;
1104 
1105 	case  PT_GET_SIGINFO:
1106 		if (data != sizeof(psi)) {
1107 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
1108 			    sizeof(psi)));
1109 			error = EINVAL;
1110 			break;
1111 		}
1112 		mutex_enter(t->p_lock);
1113 		psi.psi_siginfo._info = t->p_sigctx.ps_info;
1114 		psi.psi_lwpid = t->p_sigctx.ps_lwp;
1115 		mutex_exit(t->p_lock);
1116 
1117 		error = copyout(&psi, addr, sizeof(psi));
1118 		if (error)
1119 			break;
1120 
1121 		break;
1122 
1123 	case  PT_SET_SIGMASK:
1124 		write = 1;
1125 
1126 	case  PT_GET_SIGMASK:
1127 		/* write = 0 done above. */
1128 
1129 		tmp = data;
1130 		if (tmp != 0 && t->p_nlwps > 1) {
1131 			lwp_delref(lt);
1132 			mutex_enter(t->p_lock);
1133 			lt = lwp_find(t, tmp);
1134 			if (lt == NULL) {
1135 				mutex_exit(t->p_lock);
1136 				error = ESRCH;
1137 				break;
1138 			}
1139 			lwp_addref(lt);
1140 			mutex_exit(t->p_lock);
1141 		}
1142 
1143 		if (lt->l_flag & LW_SYSTEM)
1144 			error = EINVAL;
1145 		else if (write == 1) {
1146 			error = copyin(addr, &lt->l_sigmask, sizeof(sigset_t));
1147 			sigminusset(&sigcantmask, &lt->l_sigmask);
1148 		} else
1149 			error = copyout(&lt->l_sigmask, addr, sizeof(sigset_t));
1150 
1151 		break;
1152 
1153 	case  PT_RESUME:
1154 		write = 1;
1155 
1156 	case  PT_SUSPEND:
1157 		/* write = 0 done above. */
1158 
1159 		tmp = data;
1160 		if (tmp != 0 && t->p_nlwps > 1) {
1161 			lwp_delref(lt);
1162 			mutex_enter(t->p_lock);
1163 			lt = lwp_find(t, tmp);
1164 			if (lt == NULL) {
1165 				mutex_exit(t->p_lock);
1166 				error = ESRCH;
1167 				break;
1168 			}
1169 			lwp_addref(lt);
1170 			mutex_exit(t->p_lock);
1171 		}
1172 		if (lt->l_flag & LW_SYSTEM) {
1173 			error = EINVAL;
1174 		} else {
1175 			lwp_lock(lt);
1176 			if (write == 0)
1177 				lt->l_flag |= LW_WSUSPEND;
1178 			else
1179 				lt->l_flag &= ~LW_WSUSPEND;
1180 			lwp_unlock(lt);
1181 		}
1182 		break;
1183 
1184 #ifdef PT_SETREGS
1185 	case  PT_SETREGS:
1186 		write = 1;
1187 #endif
1188 #ifdef PT_GETREGS
1189 	case  PT_GETREGS:
1190 		/* write = 0 done above. */
1191 #endif
1192 #if defined(PT_SETREGS) || defined(PT_GETREGS)
1193 		tmp = data;
1194 		if (tmp != 0 && t->p_nlwps > 1) {
1195 			lwp_delref(lt);
1196 			mutex_enter(t->p_lock);
1197 			lt = lwp_find(t, tmp);
1198 			if (lt == NULL) {
1199 				mutex_exit(t->p_lock);
1200 				error = ESRCH;
1201 				break;
1202 			}
1203 			lwp_addref(lt);
1204 			mutex_exit(t->p_lock);
1205 		}
1206 		if (!process_validregs(lt))
1207 			error = EINVAL;
1208 		else {
1209 			error = proc_vmspace_getref(p, &vm);
1210 			if (error)
1211 				break;
1212 			iov.iov_base = addr;
1213 			iov.iov_len = PROC_REGSZ(p);
1214 			uio.uio_iov = &iov;
1215 			uio.uio_iovcnt = 1;
1216 			uio.uio_offset = 0;
1217 			uio.uio_resid = iov.iov_len;
1218 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1219 			uio.uio_vmspace = vm;
1220 
1221 			error = ptm->ptm_doregs(l, lt, &uio);
1222 			uvmspace_free(vm);
1223 		}
1224 		break;
1225 #endif
1226 
1227 #ifdef PT_SETFPREGS
1228 	case  PT_SETFPREGS:
1229 		write = 1;
1230 		/*FALLTHROUGH*/
1231 #endif
1232 #ifdef PT_GETFPREGS
1233 	case  PT_GETFPREGS:
1234 		/* write = 0 done above. */
1235 #endif
1236 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
1237 		tmp = data;
1238 		if (tmp != 0 && t->p_nlwps > 1) {
1239 			lwp_delref(lt);
1240 			mutex_enter(t->p_lock);
1241 			lt = lwp_find(t, tmp);
1242 			if (lt == NULL) {
1243 				mutex_exit(t->p_lock);
1244 				error = ESRCH;
1245 				break;
1246 			}
1247 			lwp_addref(lt);
1248 			mutex_exit(t->p_lock);
1249 		}
1250 		if (!process_validfpregs(lt))
1251 			error = EINVAL;
1252 		else {
1253 			error = proc_vmspace_getref(p, &vm);
1254 			if (error)
1255 				break;
1256 			iov.iov_base = addr;
1257 			iov.iov_len = PROC_FPREGSZ(p);
1258 			uio.uio_iov = &iov;
1259 			uio.uio_iovcnt = 1;
1260 			uio.uio_offset = 0;
1261 			uio.uio_resid = iov.iov_len;
1262 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1263 			uio.uio_vmspace = vm;
1264 
1265 			error = ptm->ptm_dofpregs(l, lt, &uio);
1266 			uvmspace_free(vm);
1267 		}
1268 		break;
1269 #endif
1270 
1271 #ifdef PT_SETDBREGS
1272 	case  PT_SETDBREGS:
1273 		write = 1;
1274 		/*FALLTHROUGH*/
1275 #endif
1276 #ifdef PT_GETDBREGS
1277 	case  PT_GETDBREGS:
1278 		/* write = 0 done above. */
1279 #endif
1280 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
1281 		tmp = data;
1282 		if (tmp != 0 && t->p_nlwps > 1) {
1283 			lwp_delref(lt);
1284 			mutex_enter(t->p_lock);
1285 			lt = lwp_find(t, tmp);
1286 			if (lt == NULL) {
1287 				mutex_exit(t->p_lock);
1288 				error = ESRCH;
1289 				break;
1290 			}
1291 			lwp_addref(lt);
1292 			mutex_exit(t->p_lock);
1293 		}
1294 		if (!process_validdbregs(lt))
1295 			error = EINVAL;
1296 		else {
1297 			error = proc_vmspace_getref(p, &vm);
1298 			if (error)
1299 				break;
1300 			iov.iov_base = addr;
1301 			iov.iov_len = PROC_DBREGSZ(p);
1302 			uio.uio_iov = &iov;
1303 			uio.uio_iovcnt = 1;
1304 			uio.uio_offset = 0;
1305 			uio.uio_resid = iov.iov_len;
1306 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
1307 			uio.uio_vmspace = vm;
1308 
1309 			error = ptm->ptm_dodbregs(l, lt, &uio);
1310 			uvmspace_free(vm);
1311 		}
1312 		break;
1313 #endif
1314 
1315 #ifdef __HAVE_PTRACE_MACHDEP
1316 	PTRACE_MACHDEP_REQUEST_CASES
1317 		error = ptrace_machdep_dorequest(l, lt, req, addr, data);
1318 		break;
1319 #endif
1320 	}
1321 
1322 	if (pheld) {
1323 		mutex_exit(t->p_lock);
1324 		mutex_exit(proc_lock);
1325 	}
1326 	if (lt != NULL)
1327 		lwp_delref(lt);
1328 	rw_exit(&t->p_reflock);
1329 
1330 	return error;
1331 }
1332 
1333 int
1334 process_doregs(struct lwp *curl /*tracer*/,
1335     struct lwp *l /*traced*/,
1336     struct uio *uio)
1337 {
1338 #if defined(PT_GETREGS) || defined(PT_SETREGS)
1339 	int error;
1340 	struct reg r;
1341 	char *kv;
1342 	int kl;
1343 
1344 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
1345 		return EINVAL;
1346 
1347 	kl = sizeof(r);
1348 	kv = (char *)&r;
1349 
1350 	kv += uio->uio_offset;
1351 	kl -= uio->uio_offset;
1352 	if ((size_t)kl > uio->uio_resid)
1353 		kl = uio->uio_resid;
1354 
1355 	error = process_read_regs(l, &r);
1356 	if (error == 0)
1357 		error = uiomove(kv, kl, uio);
1358 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1359 		if (l->l_stat != LSSTOP)
1360 			error = EBUSY;
1361 		else
1362 			error = process_write_regs(l, &r);
1363 	}
1364 
1365 	uio->uio_offset = 0;
1366 	return error;
1367 #else
1368 	return EINVAL;
1369 #endif
1370 }
1371 
1372 int
1373 process_validregs(struct lwp *l)
1374 {
1375 
1376 #if defined(PT_SETREGS) || defined(PT_GETREGS)
1377 	return (l->l_flag & LW_SYSTEM) == 0;
1378 #else
1379 	return 0;
1380 #endif
1381 }
1382 
1383 int
1384 process_dofpregs(struct lwp *curl /*tracer*/,
1385     struct lwp *l /*traced*/,
1386     struct uio *uio)
1387 {
1388 #if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
1389 	int error;
1390 	struct fpreg r;
1391 	char *kv;
1392 	size_t kl;
1393 
1394 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
1395 		return EINVAL;
1396 
1397 	kl = sizeof(r);
1398 	kv = (char *)&r;
1399 
1400 	kv += uio->uio_offset;
1401 	kl -= uio->uio_offset;
1402 	if (kl > uio->uio_resid)
1403 		kl = uio->uio_resid;
1404 
1405 	error = process_read_fpregs(l, &r, &kl);
1406 	if (error == 0)
1407 		error = uiomove(kv, kl, uio);
1408 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1409 		if (l->l_stat != LSSTOP)
1410 			error = EBUSY;
1411 		else
1412 			error = process_write_fpregs(l, &r, kl);
1413 	}
1414 	uio->uio_offset = 0;
1415 	return error;
1416 #else
1417 	return EINVAL;
1418 #endif
1419 }
1420 
1421 int
1422 process_validfpregs(struct lwp *l)
1423 {
1424 
1425 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
1426 	return (l->l_flag & LW_SYSTEM) == 0;
1427 #else
1428 	return 0;
1429 #endif
1430 }
1431 
1432 int
1433 process_dodbregs(struct lwp *curl /*tracer*/,
1434     struct lwp *l /*traced*/,
1435     struct uio *uio)
1436 {
1437 #if defined(PT_GETDBREGS) || defined(PT_SETDBREGS)
1438 	int error;
1439 	struct dbreg r;
1440 	char *kv;
1441 	size_t kl;
1442 
1443 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
1444 		return EINVAL;
1445 
1446 	kl = sizeof(r);
1447 	kv = (char *)&r;
1448 
1449 	kv += uio->uio_offset;
1450 	kl -= uio->uio_offset;
1451 	if (kl > uio->uio_resid)
1452 		kl = uio->uio_resid;
1453 
1454 	error = process_read_dbregs(l, &r, &kl);
1455 	if (error == 0)
1456 		error = uiomove(kv, kl, uio);
1457 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
1458 		if (l->l_stat != LSSTOP)
1459 			error = EBUSY;
1460 		else
1461 			error = process_write_dbregs(l, &r, kl);
1462 	}
1463 	uio->uio_offset = 0;
1464 	return error;
1465 #else
1466 	return EINVAL;
1467 #endif
1468 }
1469 
1470 int
1471 process_validdbregs(struct lwp *l)
1472 {
1473 
1474 #if defined(PT_SETDBREGS) || defined(PT_GETDBREGS)
1475 	return (l->l_flag & LW_SYSTEM) == 0;
1476 #else
1477 	return 0;
1478 #endif
1479 }
1480 
1481 static int
1482 process_auxv_offset(struct proc *p, struct uio *uio)
1483 {
1484 	struct ps_strings pss;
1485 	int error;
1486 	off_t off = (off_t)p->p_psstrp;
1487 
1488 	if ((error = copyin_psstrings(p, &pss)) != 0)
1489 		return error;
1490 
1491 	if (pss.ps_envstr == NULL)
1492 		return EIO;
1493 
1494 	uio->uio_offset += (off_t)(vaddr_t)(pss.ps_envstr + pss.ps_nenvstr + 1);
1495 #ifdef __MACHINE_STACK_GROWS_UP
1496 	if (uio->uio_offset < off)
1497 		return EIO;
1498 #else
1499 	if (uio->uio_offset > off)
1500 		return EIO;
1501 	if ((uio->uio_offset + uio->uio_resid) > off)
1502 		uio->uio_resid = off - uio->uio_offset;
1503 #endif
1504 	return 0;
1505 }
1506 #endif /* PTRACE */
1507 
1508 MODULE(MODULE_CLASS_EXEC, ptrace_common, "");
1509 
1510 static int
1511 ptrace_common_modcmd(modcmd_t cmd, void *arg)
1512 {
1513         int error;
1514 
1515         switch (cmd) {
1516         case MODULE_CMD_INIT:
1517                 error = ptrace_init();
1518                 break;
1519         case MODULE_CMD_FINI:
1520                 error = ptrace_fini();
1521                 break;
1522         default:
1523 		ptrace_hooks();
1524                 error = ENOTTY;
1525                 break;
1526         }
1527         return error;
1528 }
1529