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sys_ptrace_common.c revision 1.4
      1 /*	$NetBSD: sys_ptrace_common.c,v 1.4 2016/11/12 20:03:17 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 1.4 2016/11/12 20:03:17 christos 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 	case PT_SET_EVENT_MASK:
    206 	case PT_GET_EVENT_MASK:
    207 	case PT_GET_PROCESS_STATE:
    208 #ifdef __HAVE_PTRACE_MACHDEP
    209 	PTRACE_MACHDEP_REQUEST_CASES
    210 #endif
    211 		if (kauth_cred_getuid(cred) != kauth_cred_getuid(p->p_cred) ||
    212 		    ISSET(p->p_flag, PK_SUGID)) {
    213 			break;
    214 		}
    215 
    216 		result = KAUTH_RESULT_ALLOW;
    217 
    218 	break;
    219 
    220 #ifdef PT_STEP
    221 	case PT_STEP:
    222 #endif
    223 	case PT_CONTINUE:
    224 	case PT_KILL:
    225 	case PT_DETACH:
    226 	case PT_LWPINFO:
    227 	case PT_SYSCALL:
    228 	case PT_SYSCALLEMU:
    229 	case PT_DUMPCORE:
    230 		result = KAUTH_RESULT_ALLOW;
    231 		break;
    232 
    233 	default:
    234 		break;
    235 	}
    236 
    237  out:
    238 #if 0
    239 	mutex_enter(&ptrace_mtx);
    240 	if (--ptrace_cbref == 0)
    241 		cv_broadcast(&ptrace_cv);
    242 	mutex_exit(&ptrace_mtx);
    243 #endif
    244 
    245 	return result;
    246 }
    247 
    248 int
    249 ptrace_init(void)
    250 {
    251 
    252 #if 0
    253 	mutex_init(&ptrace_mtx, MUTEX_DEFAULT, IPL_NONE);
    254 	cv_init(&ptrace_cv, "ptracecb");
    255 	ptrace_cbref = 0;
    256 #endif
    257 	ptrace_listener = kauth_listen_scope(KAUTH_SCOPE_PROCESS,
    258 	    ptrace_listener_cb, NULL);
    259 	return 0;
    260 }
    261 
    262 int
    263 ptrace_fini(void)
    264 {
    265 
    266 	kauth_unlisten_scope(ptrace_listener);
    267 
    268 #if 0
    269 	/* Make sure no-one is executing our kauth listener */
    270 
    271 	mutex_enter(&ptrace_mtx);
    272 	while (ptrace_cbref != 0)
    273 		cv_wait(&ptrace_cv, &ptrace_mtx);
    274 	mutex_exit(&ptrace_mtx);
    275 	mutex_destroy(&ptrace_mtx);
    276 	cv_destroy(&ptrace_cv);
    277 #endif
    278 
    279 	return 0;
    280 }
    281 
    282 int
    283 do_ptrace(struct ptrace_methods *ptm, struct lwp *l, int req, pid_t pid,
    284     void *addr, int data, register_t *retval)
    285 {
    286 	struct proc *p = l->l_proc;
    287 	struct lwp *lt;
    288 #ifdef PT_STEP
    289 	struct lwp *lt2;
    290 #endif
    291 	struct proc *t;				/* target process */
    292 	struct uio uio;
    293 	struct iovec iov;
    294 	struct ptrace_io_desc piod;
    295 	struct ptrace_event pe;
    296 	struct ptrace_state ps;
    297 	struct ptrace_lwpinfo pl;
    298 	struct vmspace *vm;
    299 	int error, write, tmp, pheld;
    300 	int signo = 0;
    301 	int resume_all;
    302 	ksiginfo_t ksi;
    303 	char *path;
    304 	int len = 0;
    305 	error = 0;
    306 
    307 	/*
    308 	 * If attaching or detaching, we need to get a write hold on the
    309 	 * proclist lock so that we can re-parent the target process.
    310 	 */
    311 	mutex_enter(proc_lock);
    312 
    313 	/* "A foolish consistency..." XXX */
    314 	if (req == PT_TRACE_ME) {
    315 		t = p;
    316 		mutex_enter(t->p_lock);
    317 	} else {
    318 		/* Find the process we're supposed to be operating on. */
    319 		t = proc_find(pid);
    320 		if (t == NULL) {
    321 			mutex_exit(proc_lock);
    322 			return ESRCH;
    323 		}
    324 
    325 		/* XXX-elad */
    326 		mutex_enter(t->p_lock);
    327 		error = kauth_authorize_process(l->l_cred, KAUTH_PROCESS_CANSEE,
    328 		    t, KAUTH_ARG(KAUTH_REQ_PROCESS_CANSEE_ENTRY), NULL, NULL);
    329 		if (error) {
    330 			mutex_exit(proc_lock);
    331 			mutex_exit(t->p_lock);
    332 			return ESRCH;
    333 		}
    334 	}
    335 
    336 	/*
    337 	 * Grab a reference on the process to prevent it from execing or
    338 	 * exiting.
    339 	 */
    340 	if (!rw_tryenter(&t->p_reflock, RW_READER)) {
    341 		mutex_exit(proc_lock);
    342 		mutex_exit(t->p_lock);
    343 		return EBUSY;
    344 	}
    345 
    346 	/* Make sure we can operate on it. */
    347 	switch (req) {
    348 	case  PT_TRACE_ME:
    349 		/* Saying that you're being traced is always legal. */
    350 		break;
    351 
    352 	case  PT_ATTACH:
    353 		/*
    354 		 * You can't attach to a process if:
    355 		 *	(1) it's the process that's doing the attaching,
    356 		 */
    357 		if (t->p_pid == p->p_pid) {
    358 			error = EINVAL;
    359 			break;
    360 		}
    361 
    362 		/*
    363 		 *  (2) it's a system process
    364 		 */
    365 		if (t->p_flag & PK_SYSTEM) {
    366 			error = EPERM;
    367 			break;
    368 		}
    369 
    370 		/*
    371 		 *	(3) it's already being traced, or
    372 		 */
    373 		if (ISSET(t->p_slflag, PSL_TRACED)) {
    374 			error = EBUSY;
    375 			break;
    376 		}
    377 
    378 		/*
    379 		 * 	(4) the tracer is chrooted, and its root directory is
    380 		 * 	    not at or above the root directory of the tracee
    381 		 */
    382 		mutex_exit(t->p_lock);	/* XXXSMP */
    383 		tmp = proc_isunder(t, l);
    384 		mutex_enter(t->p_lock);	/* XXXSMP */
    385 		if (!tmp) {
    386 			error = EPERM;
    387 			break;
    388 		}
    389 		break;
    390 
    391 	case  PT_READ_I:
    392 	case  PT_READ_D:
    393 	case  PT_WRITE_I:
    394 	case  PT_WRITE_D:
    395 	case  PT_IO:
    396 #ifdef PT_GETREGS
    397 	case  PT_GETREGS:
    398 #endif
    399 #ifdef PT_SETREGS
    400 	case  PT_SETREGS:
    401 #endif
    402 #ifdef PT_GETFPREGS
    403 	case  PT_GETFPREGS:
    404 #endif
    405 #ifdef PT_SETFPREGS
    406 	case  PT_SETFPREGS:
    407 #endif
    408 #ifdef __HAVE_PTRACE_MACHDEP
    409 	PTRACE_MACHDEP_REQUEST_CASES
    410 #endif
    411 		/*
    412 		 * You can't read/write the memory or registers of a process
    413 		 * if the tracer is chrooted, and its root directory is not at
    414 		 * or above the root directory of the tracee.
    415 		 */
    416 		mutex_exit(t->p_lock);	/* XXXSMP */
    417 		tmp = proc_isunder(t, l);
    418 		mutex_enter(t->p_lock);	/* XXXSMP */
    419 		if (!tmp) {
    420 			error = EPERM;
    421 			break;
    422 		}
    423 		/*FALLTHROUGH*/
    424 
    425 	case  PT_CONTINUE:
    426 	case  PT_KILL:
    427 	case  PT_DETACH:
    428 	case  PT_LWPINFO:
    429 	case  PT_SYSCALL:
    430 	case  PT_SYSCALLEMU:
    431 	case  PT_DUMPCORE:
    432 #ifdef PT_STEP
    433 	case  PT_STEP:
    434 #endif
    435 	case  PT_SET_EVENT_MASK:
    436 	case  PT_GET_EVENT_MASK:
    437 	case  PT_GET_PROCESS_STATE:
    438 		/*
    439 		 * You can't do what you want to the process if:
    440 		 *	(1) It's not being traced at all,
    441 		 */
    442 		if (!ISSET(t->p_slflag, PSL_TRACED)) {
    443 			error = EPERM;
    444 			break;
    445 		}
    446 
    447 		/*
    448 		 *	(2) it's being traced by procfs (which has
    449 		 *	    different signal delivery semantics),
    450 		 */
    451 		if (ISSET(t->p_slflag, PSL_FSTRACE)) {
    452 			DPRINTF(("file system traced\n"));
    453 			error = EBUSY;
    454 			break;
    455 		}
    456 
    457 		/*
    458 		 *	(3) it's not being traced by _you_, or
    459 		 */
    460 		if (t->p_pptr != p) {
    461 			DPRINTF(("parent %d != %d\n", t->p_pptr->p_pid,
    462 			    p->p_pid));
    463 			error = EBUSY;
    464 			break;
    465 		}
    466 
    467 		/*
    468 		 *	(4) it's not currently stopped.
    469 		 */
    470 		if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) {
    471 			DPRINTF(("stat %d flag %d\n", t->p_stat,
    472 			    !t->p_waited));
    473 			error = EBUSY;
    474 			break;
    475 		}
    476 		break;
    477 
    478 	default:			/* It was not a legal request. */
    479 		error = EINVAL;
    480 		break;
    481 	}
    482 
    483 	if (error == 0) {
    484 		error = kauth_authorize_process(l->l_cred,
    485 		    KAUTH_PROCESS_PTRACE, t, KAUTH_ARG(req),
    486 		    NULL, NULL);
    487 	}
    488 	if (error == 0) {
    489 		lt = lwp_find_first(t);
    490 		if (lt == NULL)
    491 			error = ESRCH;
    492 	}
    493 
    494 	if (error != 0) {
    495 		mutex_exit(proc_lock);
    496 		mutex_exit(t->p_lock);
    497 		rw_exit(&t->p_reflock);
    498 		return error;
    499 	}
    500 
    501 	/* Do single-step fixup if needed. */
    502 	FIX_SSTEP(t);
    503 	KASSERT(lt != NULL);
    504 	lwp_addref(lt);
    505 
    506 	/*
    507 	 * Which locks do we need held? XXX Ugly.
    508 	 */
    509 	switch (req) {
    510 #ifdef PT_STEP
    511 	case PT_STEP:
    512 #endif
    513 	case PT_CONTINUE:
    514 	case PT_DETACH:
    515 	case PT_KILL:
    516 	case PT_SYSCALL:
    517 	case PT_SYSCALLEMU:
    518 	case PT_ATTACH:
    519 	case PT_TRACE_ME:
    520 		pheld = 1;
    521 		break;
    522 	default:
    523 		mutex_exit(proc_lock);
    524 		mutex_exit(t->p_lock);
    525 		pheld = 0;
    526 		break;
    527 	}
    528 
    529 	/* Now do the operation. */
    530 	write = 0;
    531 	*retval = 0;
    532 	tmp = 0;
    533 	resume_all = 1;
    534 
    535 	switch (req) {
    536 	case  PT_TRACE_ME:
    537 		/* Just set the trace flag. */
    538 		SET(t->p_slflag, PSL_TRACED);
    539 		t->p_opptr = t->p_pptr;
    540 		break;
    541 
    542 	case  PT_WRITE_I:		/* XXX no separate I and D spaces */
    543 	case  PT_WRITE_D:
    544 #if defined(__HAVE_RAS)
    545 		/*
    546 		 * Can't write to a RAS
    547 		 */
    548 		if (ras_lookup(t, addr) != (void *)-1) {
    549 			error = EACCES;
    550 			break;
    551 		}
    552 #endif
    553 		write = 1;
    554 		tmp = data;
    555 		/* FALLTHROUGH */
    556 
    557 	case  PT_READ_I:		/* XXX no separate I and D spaces */
    558 	case  PT_READ_D:
    559 		/* write = 0 done above. */
    560 		iov.iov_base = (void *)&tmp;
    561 		iov.iov_len = sizeof(tmp);
    562 		uio.uio_iov = &iov;
    563 		uio.uio_iovcnt = 1;
    564 		uio.uio_offset = (off_t)(unsigned long)addr;
    565 		uio.uio_resid = sizeof(tmp);
    566 		uio.uio_rw = write ? UIO_WRITE : UIO_READ;
    567 		UIO_SETUP_SYSSPACE(&uio);
    568 
    569 		error = process_domem(l, lt, &uio);
    570 		if (!write)
    571 			*retval = tmp;
    572 		break;
    573 
    574 	case  PT_IO:
    575 		error = ptm->ptm_copyinpiod(&piod, addr);
    576 		if (error)
    577 			break;
    578 
    579 		iov.iov_base = piod.piod_addr;
    580 		iov.iov_len = piod.piod_len;
    581 		uio.uio_iov = &iov;
    582 		uio.uio_iovcnt = 1;
    583 		uio.uio_offset = (off_t)(unsigned long)piod.piod_offs;
    584 		uio.uio_resid = piod.piod_len;
    585 
    586 		switch (piod.piod_op) {
    587 		case PIOD_READ_D:
    588 		case PIOD_READ_I:
    589 			uio.uio_rw = UIO_READ;
    590 			break;
    591 		case PIOD_WRITE_D:
    592 		case PIOD_WRITE_I:
    593 			/*
    594 			 * Can't write to a RAS
    595 			 */
    596 			if (ras_lookup(t, addr) != (void *)-1) {
    597 				return EACCES;
    598 			}
    599 			uio.uio_rw = UIO_WRITE;
    600 			break;
    601 		case PIOD_READ_AUXV:
    602 			req = PT_READ_D;
    603 			uio.uio_rw = UIO_READ;
    604 			tmp = t->p_execsw->es_arglen * PROC_PTRSZ(t);
    605 			if (uio.uio_offset > tmp)
    606 				return EIO;
    607 			if (uio.uio_resid > tmp - uio.uio_offset)
    608 				uio.uio_resid = tmp - uio.uio_offset;
    609 			piod.piod_len = iov.iov_len = uio.uio_resid;
    610 			error = process_auxv_offset(t, &uio);
    611 			if (error)
    612 				return error;
    613 			break;
    614 		default:
    615 			error = EINVAL;
    616 			break;
    617 		}
    618 		if (error)
    619 			break;
    620 		error = proc_vmspace_getref(l->l_proc, &vm);
    621 		if (error)
    622 			break;
    623 		uio.uio_vmspace = vm;
    624 
    625 		error = process_domem(l, lt, &uio);
    626 		piod.piod_len -= uio.uio_resid;
    627 		(void) ptm->ptm_copyoutpiod(&piod, addr);
    628 
    629 		uvmspace_free(vm);
    630 		break;
    631 
    632 	case  PT_DUMPCORE:
    633 		if ((path = addr) != NULL) {
    634 			char *dst;
    635 			len = data;
    636 
    637 			if (len < 0 || len >= MAXPATHLEN) {
    638 				error = EINVAL;
    639 				break;
    640 			}
    641 			dst = kmem_alloc(len + 1, KM_SLEEP);
    642 			if ((error = copyin(path, dst, len)) != 0) {
    643 				kmem_free(dst, len + 1);
    644 				break;
    645 			}
    646 			path = dst;
    647 			path[len] = '\0';
    648 		}
    649 		error = (*coredump_vec)(lt, path);
    650 		if (path)
    651 			kmem_free(path, len + 1);
    652 		break;
    653 
    654 #ifdef PT_STEP
    655 	case  PT_STEP:
    656 		/*
    657 		 * From the 4.4BSD PRM:
    658 		 * "Execution continues as in request PT_CONTINUE; however
    659 		 * as soon as possible after execution of at least one
    660 		 * instruction, execution stops again. [ ... ]"
    661 		 */
    662 #endif
    663 	case  PT_CONTINUE:
    664 	case  PT_SYSCALL:
    665 	case  PT_DETACH:
    666 		if (req == PT_SYSCALL) {
    667 			if (!ISSET(t->p_slflag, PSL_SYSCALL)) {
    668 				SET(t->p_slflag, PSL_SYSCALL);
    669 #ifdef __HAVE_SYSCALL_INTERN
    670 				(*t->p_emul->e_syscall_intern)(t);
    671 #endif
    672 			}
    673 		} else {
    674 			if (ISSET(t->p_slflag, PSL_SYSCALL)) {
    675 				CLR(t->p_slflag, PSL_SYSCALL);
    676 #ifdef __HAVE_SYSCALL_INTERN
    677 				(*t->p_emul->e_syscall_intern)(t);
    678 #endif
    679 			}
    680 		}
    681 		t->p_trace_enabled = trace_is_enabled(t);
    682 
    683 		/*
    684 		 * Pick up the LWPID, if supplied.  There are two cases:
    685 		 * data < 0 : step or continue single thread, lwp = -data
    686 		 * data > 0 in PT_STEP : step this thread, continue others
    687 		 * For operations other than PT_STEP, data > 0 means
    688 		 * data is the signo to deliver to the process.
    689 		 */
    690 		tmp = data;
    691 		if (tmp >= 0) {
    692 #ifdef PT_STEP
    693 			if (req == PT_STEP)
    694 				signo = 0;
    695 			else
    696 #endif
    697 			{
    698 				signo = tmp;
    699 				tmp = 0;	/* don't search for LWP */
    700 			}
    701 		} else
    702 			tmp = -tmp;
    703 
    704 		if (tmp > 0) {
    705 			if (req == PT_DETACH) {
    706 				error = EINVAL;
    707 				break;
    708 			}
    709 			lwp_delref2 (lt);
    710 			lt = lwp_find(t, tmp);
    711 			if (lt == NULL) {
    712 				error = ESRCH;
    713 				break;
    714 			}
    715 			lwp_addref(lt);
    716 			resume_all = 0;
    717 			signo = 0;
    718 		}
    719 
    720 		/*
    721 		 * From the 4.4BSD PRM:
    722 		 * "The data argument is taken as a signal number and the
    723 		 * child's execution continues at location addr as if it
    724 		 * incurred that signal.  Normally the signal number will
    725 		 * be either 0 to indicate that the signal that caused the
    726 		 * stop should be ignored, or that value fetched out of
    727 		 * the process's image indicating which signal caused
    728 		 * the stop.  If addr is (int *)1 then execution continues
    729 		 * from where it stopped."
    730 		 */
    731 
    732 		/* Check that the data is a valid signal number or zero. */
    733 		if (signo < 0 || signo >= NSIG) {
    734 			error = EINVAL;
    735 			break;
    736 		}
    737 
    738 		/* If the address parameter is not (int *)1, set the pc. */
    739 		if ((int *)addr != (int *)1) {
    740 			error = process_set_pc(lt, addr);
    741 			if (error != 0)
    742 				break;
    743 		}
    744 #ifdef PT_STEP
    745 		/*
    746 		 * Arrange for a single-step, if that's requested and possible.
    747 		 * More precisely, set the single step status as requested for
    748 		 * the requested thread, and clear it for other threads.
    749 		 */
    750 		LIST_FOREACH(lt2, &t->p_lwps, l_sibling) {
    751 			if (lt != lt2) {
    752 				lwp_lock(lt2);
    753 				process_sstep(lt2, 0);
    754 				lwp_unlock(lt2);
    755 			}
    756 		}
    757 		error = process_sstep(lt, req == PT_STEP);
    758 		if (error)
    759 			break;
    760 #endif
    761 		if (req == PT_DETACH) {
    762 			CLR(t->p_slflag, PSL_TRACED|PSL_FSTRACE|PSL_SYSCALL);
    763 
    764 			/* give process back to original parent or init */
    765 			if (t->p_opptr != t->p_pptr) {
    766 				struct proc *pp = t->p_opptr;
    767 				proc_reparent(t, pp ? pp : initproc);
    768 			}
    769 
    770 			/* not being traced any more */
    771 			t->p_opptr = NULL;
    772 		}
    773 	sendsig:
    774 		t->p_fpid = 0;
    775 		/* Finally, deliver the requested signal (or none). */
    776 		if (t->p_stat == SSTOP) {
    777 			/*
    778 			 * Unstop the process.  If it needs to take a
    779 			 * signal, make all efforts to ensure that at
    780 			 * an LWP runs to see it.
    781 			 */
    782 			t->p_xsig = signo;
    783 			if (resume_all)
    784 				proc_unstop(t);
    785 			else
    786 				lwp_unstop(lt);
    787 		} else if (signo != 0) {
    788 			KSI_INIT_EMPTY(&ksi);
    789 			ksi.ksi_signo = signo;
    790 			kpsignal2(t, &ksi);
    791 		}
    792 		break;
    793 
    794 	case  PT_SYSCALLEMU:
    795 		if (!ISSET(t->p_slflag, PSL_SYSCALL) || t->p_stat != SSTOP) {
    796 			error = EINVAL;
    797 			break;
    798 		}
    799 		SET(t->p_slflag, PSL_SYSCALLEMU);
    800 		break;
    801 
    802 	case  PT_KILL:
    803 		/* just send the process a KILL signal. */
    804 		signo = SIGKILL;
    805 		goto sendsig;	/* in PT_CONTINUE, above. */
    806 
    807 	case  PT_ATTACH:
    808 		/*
    809 		 * Go ahead and set the trace flag.
    810 		 * Save the old parent (it's reset in
    811 		 *   _DETACH, and also in kern_exit.c:wait4()
    812 		 * Reparent the process so that the tracing
    813 		 *   proc gets to see all the action.
    814 		 * Stop the target.
    815 		 */
    816 		proc_changeparent(t, p);
    817 		signo = SIGSTOP;
    818 		goto sendsig;
    819 
    820 	case  PT_GET_EVENT_MASK:
    821 		if (data != sizeof(pe)) {
    822 			DPRINTF(("ptrace(%d): %d != %zu\n", req,
    823 			    data, sizeof(pe)));
    824 			error = EINVAL;
    825 			break;
    826 		}
    827 		memset(&pe, 0, sizeof(pe));
    828 		pe.pe_set_event = ISSET(t->p_slflag, PSL_TRACEFORK) ?
    829 		    PTRACE_FORK : 0;
    830 		error = copyout(&pe, addr, sizeof(pe));
    831 		break;
    832 
    833 	case  PT_SET_EVENT_MASK:
    834 		if (data != sizeof(pe)) {
    835 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
    836 			    sizeof(pe)));
    837 			error = EINVAL;
    838 			break;
    839 		}
    840 		if ((error = copyin(addr, &pe, sizeof(pe))) != 0)
    841 			return error;
    842 		if (pe.pe_set_event & PTRACE_FORK)
    843 			SET(t->p_slflag, PSL_TRACEFORK);
    844 		else
    845 			CLR(t->p_slflag, PSL_TRACEFORK);
    846 		break;
    847 
    848 	case  PT_GET_PROCESS_STATE:
    849 		if (data != sizeof(ps)) {
    850 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
    851 			    sizeof(ps)));
    852 			error = EINVAL;
    853 			break;
    854 		}
    855 		memset(&ps, 0, sizeof(ps));
    856 		if (t->p_fpid) {
    857 			ps.pe_report_event = PTRACE_FORK;
    858 			ps.pe_other_pid = t->p_fpid;
    859 		}
    860 		error = copyout(&ps, addr, sizeof(ps));
    861 		break;
    862 
    863 	case PT_LWPINFO:
    864 		if (data != sizeof(pl)) {
    865 			DPRINTF(("ptrace(%d): %d != %zu\n", req, data,
    866 			    sizeof(pl)));
    867 			error = EINVAL;
    868 			break;
    869 		}
    870 		error = copyin(addr, &pl, sizeof(pl));
    871 		if (error)
    872 			break;
    873 		tmp = pl.pl_lwpid;
    874 		lwp_delref(lt);
    875 		mutex_enter(t->p_lock);
    876 		if (tmp == 0)
    877 			lt = lwp_find_first(t);
    878 		else {
    879 			lt = lwp_find(t, tmp);
    880 			if (lt == NULL) {
    881 				mutex_exit(t->p_lock);
    882 				error = ESRCH;
    883 				break;
    884 			}
    885 			lt = LIST_NEXT(lt, l_sibling);
    886 		}
    887 		while (lt != NULL && !lwp_alive(lt))
    888 			lt = LIST_NEXT(lt, l_sibling);
    889 		pl.pl_lwpid = 0;
    890 		pl.pl_event = 0;
    891 		if (lt) {
    892 			lwp_addref(lt);
    893 			pl.pl_lwpid = lt->l_lid;
    894 			if (lt->l_lid == t->p_sigctx.ps_lwp)
    895 				pl.pl_event = PL_EVENT_SIGNAL;
    896 		}
    897 		mutex_exit(t->p_lock);
    898 
    899 		error = copyout(&pl, addr, sizeof(pl));
    900 		break;
    901 
    902 #ifdef PT_SETREGS
    903 	case  PT_SETREGS:
    904 		write = 1;
    905 #endif
    906 #ifdef PT_GETREGS
    907 	case  PT_GETREGS:
    908 		/* write = 0 done above. */
    909 #endif
    910 #if defined(PT_SETREGS) || defined(PT_GETREGS)
    911 		tmp = data;
    912 		if (tmp != 0 && t->p_nlwps > 1) {
    913 			lwp_delref(lt);
    914 			mutex_enter(t->p_lock);
    915 			lt = lwp_find(t, tmp);
    916 			if (lt == NULL) {
    917 				mutex_exit(t->p_lock);
    918 				error = ESRCH;
    919 				break;
    920 			}
    921 			lwp_addref(lt);
    922 			mutex_exit(t->p_lock);
    923 		}
    924 		if (!process_validregs(lt))
    925 			error = EINVAL;
    926 		else {
    927 			error = proc_vmspace_getref(p, &vm);
    928 			if (error)
    929 				break;
    930 			iov.iov_base = addr;
    931 			iov.iov_len = PROC_REGSZ(p);
    932 			uio.uio_iov = &iov;
    933 			uio.uio_iovcnt = 1;
    934 			uio.uio_offset = 0;
    935 			uio.uio_resid = iov.iov_len;
    936 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
    937 			uio.uio_vmspace = vm;
    938 
    939 			error = ptm->ptm_doregs(l, lt, &uio);
    940 			uvmspace_free(vm);
    941 		}
    942 		break;
    943 #endif
    944 
    945 #ifdef PT_SETFPREGS
    946 	case  PT_SETFPREGS:
    947 		write = 1;
    948 #endif
    949 #ifdef PT_GETFPREGS
    950 	case  PT_GETFPREGS:
    951 		/* write = 0 done above. */
    952 #endif
    953 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
    954 		tmp = data;
    955 		if (tmp != 0 && t->p_nlwps > 1) {
    956 			lwp_delref(lt);
    957 			mutex_enter(t->p_lock);
    958 			lt = lwp_find(t, tmp);
    959 			if (lt == NULL) {
    960 				mutex_exit(t->p_lock);
    961 				error = ESRCH;
    962 				break;
    963 			}
    964 			lwp_addref(lt);
    965 			mutex_exit(t->p_lock);
    966 		}
    967 		if (!process_validfpregs(lt))
    968 			error = EINVAL;
    969 		else {
    970 			error = proc_vmspace_getref(p, &vm);
    971 			if (error)
    972 				break;
    973 			iov.iov_base = addr;
    974 			iov.iov_len = PROC_FPREGSZ(p);
    975 			uio.uio_iov = &iov;
    976 			uio.uio_iovcnt = 1;
    977 			uio.uio_offset = 0;
    978 			uio.uio_resid = iov.iov_len;
    979 			uio.uio_rw = write ? UIO_WRITE : UIO_READ;
    980 			uio.uio_vmspace = vm;
    981 
    982 			error = ptm->ptm_dofpregs(l, lt, &uio);
    983 			uvmspace_free(vm);
    984 		}
    985 		break;
    986 #endif
    987 
    988 #ifdef __HAVE_PTRACE_MACHDEP
    989 	PTRACE_MACHDEP_REQUEST_CASES
    990 		error = ptrace_machdep_dorequest(l, lt, req, addr, data);
    991 		break;
    992 #endif
    993 	}
    994 
    995 	if (pheld) {
    996 		mutex_exit(t->p_lock);
    997 		mutex_exit(proc_lock);
    998 	}
    999 	if (lt != NULL)
   1000 		lwp_delref(lt);
   1001 	rw_exit(&t->p_reflock);
   1002 
   1003 	return error;
   1004 }
   1005 
   1006 int
   1007 process_doregs(struct lwp *curl /*tracer*/,
   1008     struct lwp *l /*traced*/,
   1009     struct uio *uio)
   1010 {
   1011 #if defined(PT_GETREGS) || defined(PT_SETREGS)
   1012 	int error;
   1013 	struct reg r;
   1014 	char *kv;
   1015 	int kl;
   1016 
   1017 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
   1018 		return EINVAL;
   1019 
   1020 	kl = sizeof(r);
   1021 	kv = (char *)&r;
   1022 
   1023 	kv += uio->uio_offset;
   1024 	kl -= uio->uio_offset;
   1025 	if ((size_t)kl > uio->uio_resid)
   1026 		kl = uio->uio_resid;
   1027 
   1028 	error = process_read_regs(l, &r);
   1029 	if (error == 0)
   1030 		error = uiomove(kv, kl, uio);
   1031 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
   1032 		if (l->l_stat != LSSTOP)
   1033 			error = EBUSY;
   1034 		else
   1035 			error = process_write_regs(l, &r);
   1036 	}
   1037 
   1038 	uio->uio_offset = 0;
   1039 	return error;
   1040 #else
   1041 	return EINVAL;
   1042 #endif
   1043 }
   1044 
   1045 int
   1046 process_validregs(struct lwp *l)
   1047 {
   1048 
   1049 #if defined(PT_SETREGS) || defined(PT_GETREGS)
   1050 	return (l->l_flag & LW_SYSTEM) == 0;
   1051 #else
   1052 	return 0;
   1053 #endif
   1054 }
   1055 
   1056 int
   1057 process_dofpregs(struct lwp *curl /*tracer*/,
   1058     struct lwp *l /*traced*/,
   1059     struct uio *uio)
   1060 {
   1061 #if defined(PT_GETFPREGS) || defined(PT_SETFPREGS)
   1062 	int error;
   1063 	struct fpreg r;
   1064 	char *kv;
   1065 	size_t kl;
   1066 
   1067 	if (uio->uio_offset < 0 || uio->uio_offset > (off_t)sizeof(r))
   1068 		return EINVAL;
   1069 
   1070 	kl = sizeof(r);
   1071 	kv = (char *)&r;
   1072 
   1073 	kv += uio->uio_offset;
   1074 	kl -= uio->uio_offset;
   1075 	if (kl > uio->uio_resid)
   1076 		kl = uio->uio_resid;
   1077 
   1078 	error = process_read_fpregs(l, &r, &kl);
   1079 	if (error == 0)
   1080 		error = uiomove(kv, kl, uio);
   1081 	if (error == 0 && uio->uio_rw == UIO_WRITE) {
   1082 		if (l->l_stat != LSSTOP)
   1083 			error = EBUSY;
   1084 		else
   1085 			error = process_write_fpregs(l, &r, kl);
   1086 	}
   1087 	uio->uio_offset = 0;
   1088 	return error;
   1089 #else
   1090 	return EINVAL;
   1091 #endif
   1092 }
   1093 
   1094 int
   1095 process_validfpregs(struct lwp *l)
   1096 {
   1097 
   1098 #if defined(PT_SETFPREGS) || defined(PT_GETFPREGS)
   1099 	return (l->l_flag & LW_SYSTEM) == 0;
   1100 #else
   1101 	return 0;
   1102 #endif
   1103 }
   1104 
   1105 static int
   1106 process_auxv_offset(struct proc *p, struct uio *uio)
   1107 {
   1108 	struct ps_strings pss;
   1109 	int error;
   1110 	off_t off = (off_t)p->p_psstrp;
   1111 
   1112 	if ((error = copyin_psstrings(p, &pss)) != 0)
   1113 		return error;
   1114 
   1115 	if (pss.ps_envstr == NULL)
   1116 		return EIO;
   1117 
   1118 	uio->uio_offset += (off_t)(vaddr_t)(pss.ps_envstr + pss.ps_nenvstr + 1);
   1119 #ifdef __MACHINE_STACK_GROWS_UP
   1120 	if (uio->uio_offset < off)
   1121 		return EIO;
   1122 #else
   1123 	if (uio->uio_offset > off)
   1124 		return EIO;
   1125 	if ((uio->uio_offset + uio->uio_resid) > off)
   1126 		uio->uio_resid = off - uio->uio_offset;
   1127 #endif
   1128 	return 0;
   1129 }
   1130 #endif /* PTRACE */
   1131 
   1132 MODULE(MODULE_CLASS_EXEC, ptrace_common, "");
   1133 
   1134 static int
   1135 ptrace_common_modcmd(modcmd_t cmd, void *arg)
   1136 {
   1137         int error;
   1138 
   1139         switch (cmd) {
   1140         case MODULE_CMD_INIT:
   1141                 error = ptrace_init();
   1142                 break;
   1143         case MODULE_CMD_FINI:
   1144                 error = ptrace_fini();
   1145                 break;
   1146         default:
   1147 		ptrace_hooks();
   1148                 error = ENOTTY;
   1149                 break;
   1150         }
   1151         return error;
   1152 }
   1153 
   1154