xref: /freebsd/lib/libthread_db/libthr_db.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*
2  * Copyright (c) 2004 Marcel Moolenaar
3  * Copyright (c) 2005 David Xu
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <proc_service.h>
32 #include <stddef.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <sys/types.h>
36 #include <sys/linker_set.h>
37 #include <sys/ptrace.h>
38 #include <thread_db.h>
39 #include <unistd.h>
40 
41 #include "thread_db_int.h"
42 
43 #define	TERMINATED	1
44 
45 struct td_thragent {
46 	TD_THRAGENT_FIELDS;
47 	psaddr_t	libthr_debug_addr;
48 	psaddr_t	thread_list_addr;
49 	psaddr_t	thread_active_threads_addr;
50 	psaddr_t	thread_keytable_addr;
51 	psaddr_t	thread_last_event_addr;
52 	psaddr_t	thread_event_mask_addr;
53 	psaddr_t	thread_bp_create_addr;
54 	psaddr_t	thread_bp_death_addr;
55 	int		thread_off_dtv;
56 	int		thread_off_tlsindex;
57 	int		thread_off_attr_flags;
58 	int		thread_size_key;
59 	int		thread_off_tcb;
60 	int		thread_off_linkmap;
61 	int		thread_off_next;
62 	int		thread_off_state;
63 	int		thread_off_tid;
64 	int		thread_max_keys;
65 	int		thread_off_key_allocated;
66 	int		thread_off_key_destructor;
67 	int		thread_off_report_events;
68 	int		thread_off_event_mask;
69 	int		thread_off_event_buf;
70 	int		thread_state_zoombie;
71 	int		thread_state_running;
72 };
73 
74 #define P2T(c) ps2td(c)
75 
76 static int pt_validate(const td_thrhandle_t *th);
77 
78 static int
79 ps2td(int c)
80 {
81 	switch (c) {
82 	case PS_OK:
83 		return TD_OK;
84 	case PS_ERR:
85 		return TD_ERR;
86 	case PS_BADPID:
87 		return TD_BADPH;
88 	case PS_BADLID:
89 		return TD_NOLWP;
90 	case PS_BADADDR:
91 		return TD_ERR;
92 	case PS_NOSYM:
93 		return TD_NOLIBTHREAD;
94 	case PS_NOFREGS:
95 		return TD_NOFPREGS;
96 	default:
97 		return TD_ERR;
98 	}
99 }
100 
101 static td_err_e
102 pt_init(void)
103 {
104 	return (0);
105 }
106 
107 static td_err_e
108 pt_ta_new(struct ps_prochandle *ph, td_thragent_t **pta)
109 {
110 #define LOOKUP_SYM(proc, sym, addr) 			\
111 	ret = ps_pglobal_lookup(proc, NULL, sym, addr);	\
112 	if (ret != 0) {					\
113 		TDBG("can not find symbol: %s\n", sym);	\
114 		ret = TD_NOLIBTHREAD;			\
115 		goto error;				\
116 	}
117 
118 #define	LOOKUP_VAL(proc, sym, val)			\
119 	ret = ps_pglobal_lookup(proc, NULL, sym, &vaddr);\
120 	if (ret != 0) {					\
121 		TDBG("can not find symbol: %s\n", sym);	\
122 		ret = TD_NOLIBTHREAD;			\
123 		goto error;				\
124 	}						\
125 	ret = ps_pread(proc, vaddr, val, sizeof(int));	\
126 	if (ret != 0) {					\
127 		TDBG("can not read value of %s\n", sym);\
128 		ret = TD_NOLIBTHREAD;			\
129 		goto error;				\
130 	}
131 
132 	td_thragent_t *ta;
133 	psaddr_t vaddr;
134 	int dbg;
135 	int ret;
136 
137 	TDBG_FUNC();
138 
139 	ta = malloc(sizeof(td_thragent_t));
140 	if (ta == NULL)
141 		return (TD_MALLOC);
142 
143 	ta->ph = ph;
144 
145 	LOOKUP_SYM(ph, "_libthr_debug",		&ta->libthr_debug_addr);
146 	LOOKUP_SYM(ph, "_thread_list",		&ta->thread_list_addr);
147 	LOOKUP_SYM(ph, "_thread_active_threads",&ta->thread_active_threads_addr);
148 	LOOKUP_SYM(ph, "_thread_keytable",	&ta->thread_keytable_addr);
149 	LOOKUP_SYM(ph, "_thread_last_event",	&ta->thread_last_event_addr);
150 	LOOKUP_SYM(ph, "_thread_event_mask",	&ta->thread_event_mask_addr);
151 	LOOKUP_SYM(ph, "_thread_bp_create",	&ta->thread_bp_create_addr);
152 	LOOKUP_SYM(ph, "_thread_bp_death",	&ta->thread_bp_death_addr);
153 	LOOKUP_VAL(ph, "_thread_off_dtv",	&ta->thread_off_dtv);
154 	LOOKUP_VAL(ph, "_thread_off_tlsindex",	&ta->thread_off_tlsindex);
155 	LOOKUP_VAL(ph, "_thread_off_attr_flags",	&ta->thread_off_attr_flags);
156 	LOOKUP_VAL(ph, "_thread_size_key",	&ta->thread_size_key);
157 	LOOKUP_VAL(ph, "_thread_off_tcb",	&ta->thread_off_tcb);
158 	LOOKUP_VAL(ph, "_thread_off_tid",	&ta->thread_off_tid);
159 	LOOKUP_VAL(ph, "_thread_off_linkmap",	&ta->thread_off_linkmap);
160 	LOOKUP_VAL(ph, "_thread_off_next",	&ta->thread_off_next);
161 	LOOKUP_VAL(ph, "_thread_off_state",	&ta->thread_off_state);
162 	LOOKUP_VAL(ph, "_thread_max_keys",	&ta->thread_max_keys);
163 	LOOKUP_VAL(ph, "_thread_off_key_allocated", &ta->thread_off_key_allocated);
164 	LOOKUP_VAL(ph, "_thread_off_key_destructor", &ta->thread_off_key_destructor);
165 	LOOKUP_VAL(ph, "_thread_state_running", &ta->thread_state_running);
166 	LOOKUP_VAL(ph, "_thread_state_zoombie", &ta->thread_state_zoombie);
167 	LOOKUP_VAL(ph, "_thread_off_report_events", &ta->thread_off_report_events);
168 	LOOKUP_VAL(ph, "_thread_off_event_mask", &ta->thread_off_event_mask);
169 	LOOKUP_VAL(ph, "_thread_off_event_buf", &ta->thread_off_event_buf);
170 	dbg = getpid();
171 	/*
172 	 * If this fails it probably means we're debugging a core file and
173 	 * can't write to it.
174 	 */
175 	ps_pwrite(ph, ta->libthr_debug_addr, &dbg, sizeof(int));
176 	*pta = ta;
177 	return (0);
178 
179 error:
180 	free(ta);
181 	return (ret);
182 }
183 
184 static td_err_e
185 pt_ta_delete(td_thragent_t *ta)
186 {
187 	int dbg;
188 
189 	TDBG_FUNC();
190 
191 	dbg = 0;
192 	/*
193 	 * Error returns from this write are not really a problem;
194 	 * the process doesn't exist any more.
195 	 */
196 	ps_pwrite(ta->ph, ta->libthr_debug_addr, &dbg, sizeof(int));
197 	free(ta);
198 	return (TD_OK);
199 }
200 
201 static td_err_e
202 pt_ta_map_id2thr(const td_thragent_t *ta, thread_t id, td_thrhandle_t *th)
203 {
204 	psaddr_t pt;
205 	int32_t lwp;
206 	int ret;
207 
208 	TDBG_FUNC();
209 
210 	if (id == 0)
211 		return (TD_NOTHR);
212 	ret = thr_pread_ptr(ta, ta->thread_list_addr, &pt);
213 	if (ret != 0)
214 		return (TD_ERR);
215 	/* Iterate through thread list to find pthread */
216 	while (pt != 0) {
217 		ret = thr_pread_int(ta, pt + ta->thread_off_tid, &lwp);
218 		if (ret != 0)
219 			return (TD_ERR);
220 		if (lwp == id)
221 			break;
222 		/* get next thread */
223 		ret = thr_pread_ptr(ta, pt + ta->thread_off_next, &pt);
224 		if (ret != 0)
225 			return (TD_ERR);
226 	}
227 	if (pt == 0)
228 		return (TD_NOTHR);
229 	th->th_ta = ta;
230 	th->th_tid = id;
231 	th->th_thread = pt;
232 	return (TD_OK);
233 }
234 
235 static td_err_e
236 pt_ta_map_lwp2thr(const td_thragent_t *ta, lwpid_t lwp, td_thrhandle_t *th)
237 {
238 	return (pt_ta_map_id2thr(ta, lwp, th));
239 }
240 
241 static td_err_e
242 pt_ta_thr_iter(const td_thragent_t *ta, td_thr_iter_f *callback,
243     void *cbdata_p, td_thr_state_e state __unused, int ti_pri __unused,
244     sigset_t *ti_sigmask_p __unused, unsigned int ti_user_flags __unused)
245 {
246 	td_thrhandle_t th;
247 	psaddr_t pt;
248 	int32_t lwp;
249 	int ret;
250 
251 	TDBG_FUNC();
252 
253 	ret = thr_pread_ptr(ta, ta->thread_list_addr, &pt);
254 	if (ret != 0)
255 		return (TD_ERR);
256 	while (pt != 0) {
257 		ret = thr_pread_int(ta, pt + ta->thread_off_tid, &lwp);
258 		if (ret != 0)
259 			return (TD_ERR);
260 		if (lwp != 0 && lwp != TERMINATED) {
261 			th.th_ta = ta;
262 			th.th_tid = (thread_t)lwp;
263 			th.th_thread = pt;
264 			if ((*callback)(&th, cbdata_p))
265 				return (TD_DBERR);
266 		}
267 		/* get next thread */
268 		ret = thr_pread_ptr(ta, pt + ta->thread_off_next, &pt);
269 		if (ret != 0)
270 			return (TD_ERR);
271 	}
272 	return (TD_OK);
273 }
274 
275 static td_err_e
276 pt_ta_tsd_iter(const td_thragent_t *ta, td_key_iter_f *ki, void *arg)
277 {
278 	void *keytable;
279 	void *destructor;
280 	int i, ret, allocated;
281 
282 	TDBG_FUNC();
283 
284 	keytable = malloc(ta->thread_max_keys * ta->thread_size_key);
285 	if (keytable == NULL)
286 		return (TD_MALLOC);
287 	ret = ps_pread(ta->ph, (psaddr_t)ta->thread_keytable_addr, keytable,
288 	               ta->thread_max_keys * ta->thread_size_key);
289 	if (ret != 0) {
290 		free(keytable);
291 		return (P2T(ret));
292 	}
293 	for (i = 0; i < ta->thread_max_keys; i++) {
294 		allocated = *(int *)(void *)((uintptr_t)keytable +
295 		    i * ta->thread_size_key + ta->thread_off_key_allocated);
296 		destructor = *(void **)(void *)((uintptr_t)keytable +
297 		    i * ta->thread_size_key + ta->thread_off_key_destructor);
298 		if (allocated) {
299 			ret = (ki)(i, destructor, arg);
300 			if (ret != 0) {
301 				free(keytable);
302 				return (TD_DBERR);
303 			}
304 		}
305 	}
306 	free(keytable);
307 	return (TD_OK);
308 }
309 
310 static td_err_e
311 pt_ta_event_addr(const td_thragent_t *ta, td_event_e event, td_notify_t *ptr)
312 {
313 
314 	TDBG_FUNC();
315 
316 	switch (event) {
317 	case TD_CREATE:
318 		ptr->type = NOTIFY_BPT;
319 		ptr->u.bptaddr = ta->thread_bp_create_addr;
320 		return (0);
321 	case TD_DEATH:
322 		ptr->type = NOTIFY_BPT;
323 		ptr->u.bptaddr = ta->thread_bp_death_addr;
324 		return (0);
325 	default:
326 		return (TD_ERR);
327 	}
328 }
329 
330 static td_err_e
331 pt_ta_set_event(const td_thragent_t *ta, td_thr_events_t *events)
332 {
333 	td_thr_events_t mask;
334 	int ret;
335 
336 	TDBG_FUNC();
337 	ret = ps_pread(ta->ph, ta->thread_event_mask_addr, &mask,
338 		sizeof(mask));
339 	if (ret != 0)
340 		return (P2T(ret));
341 	mask |= *events;
342 	ret = ps_pwrite(ta->ph, ta->thread_event_mask_addr, &mask,
343 		sizeof(mask));
344 	return (P2T(ret));
345 }
346 
347 static td_err_e
348 pt_ta_clear_event(const td_thragent_t *ta, td_thr_events_t *events)
349 {
350 	td_thr_events_t mask;
351 	int ret;
352 
353 	TDBG_FUNC();
354 	ret = ps_pread(ta->ph, ta->thread_event_mask_addr, &mask,
355 		sizeof(mask));
356 	if (ret != 0)
357 		return (P2T(ret));
358 	mask &= ~*events;
359 	ret = ps_pwrite(ta->ph, ta->thread_event_mask_addr, &mask,
360 		sizeof(mask));
361 	return (P2T(ret));
362 }
363 
364 static td_err_e
365 pt_ta_event_getmsg(const td_thragent_t *ta, td_event_msg_t *msg)
366 {
367 	static td_thrhandle_t handle;
368 
369 	psaddr_t pt;
370 	td_thr_events_e	tmp;
371 	int32_t lwp;
372 	int ret;
373 
374 	TDBG_FUNC();
375 
376 	ret = thr_pread_ptr(ta, ta->thread_last_event_addr, &pt);
377 	if (ret != 0)
378 		return (TD_ERR);
379 	if (pt == 0)
380 		return (TD_NOMSG);
381 	/*
382 	 * Take the event pointer, at the time, libthr only reports event
383 	 * once a time, so it is not a link list.
384 	 */
385 	thr_pwrite_ptr(ta, ta->thread_last_event_addr, 0);
386 
387 	/* Read event info */
388 	ret = ps_pread(ta->ph, pt + ta->thread_off_event_buf, msg, sizeof(*msg));
389 	if (ret != 0)
390 		return (P2T(ret));
391 	if (msg->event == 0)
392 		return (TD_NOMSG);
393 	/* Clear event */
394 	tmp = 0;
395 	ps_pwrite(ta->ph, pt + ta->thread_off_event_buf, &tmp, sizeof(tmp));
396 	/* Convert event */
397 	pt = msg->th_p;
398 	ret = thr_pread_int(ta, pt + ta->thread_off_tid, &lwp);
399 	if (ret != 0)
400 		return (TD_ERR);
401 	handle.th_ta = ta;
402 	handle.th_tid = lwp;
403 	handle.th_thread = pt;
404 	msg->th_p = (uintptr_t)&handle;
405 	return (0);
406 }
407 
408 static td_err_e
409 pt_dbsuspend(const td_thrhandle_t *th, int suspend)
410 {
411 	const td_thragent_t *ta = th->th_ta;
412 	int ret;
413 
414 	TDBG_FUNC();
415 
416 	ret = pt_validate(th);
417 	if (ret)
418 		return (ret);
419 
420 	if (suspend)
421 		ret = ps_lstop(ta->ph, th->th_tid);
422 	else
423 		ret = ps_lcontinue(ta->ph, th->th_tid);
424 	return (P2T(ret));
425 }
426 
427 static td_err_e
428 pt_thr_dbresume(const td_thrhandle_t *th)
429 {
430 	TDBG_FUNC();
431 
432 	return pt_dbsuspend(th, 0);
433 }
434 
435 static td_err_e
436 pt_thr_dbsuspend(const td_thrhandle_t *th)
437 {
438 	TDBG_FUNC();
439 
440 	return pt_dbsuspend(th, 1);
441 }
442 
443 static td_err_e
444 pt_thr_validate(const td_thrhandle_t *th)
445 {
446 	td_thrhandle_t temp;
447 	int ret;
448 
449 	TDBG_FUNC();
450 
451 	ret = pt_ta_map_id2thr(th->th_ta, th->th_tid, &temp);
452 	return (ret);
453 }
454 
455 static td_err_e
456 pt_thr_get_info(const td_thrhandle_t *th, td_thrinfo_t *info)
457 {
458 	const td_thragent_t *ta = th->th_ta;
459 	struct ptrace_lwpinfo linfo;
460 	int traceme;
461 	int state;
462 	int ret;
463 
464 	TDBG_FUNC();
465 
466 	bzero(info, sizeof(*info));
467 	ret = pt_validate(th);
468 	if (ret)
469 		return (ret);
470 	ret = thr_pread_int(ta, th->th_thread + ta->thread_off_state, &state);
471 	if (ret != 0)
472 		return (TD_ERR);
473 	ret = thr_pread_int(ta, th->th_thread + ta->thread_off_report_events,
474 	    &traceme);
475 	info->ti_traceme = traceme;
476 	if (ret != 0)
477 		return (TD_ERR);
478 	ret = ps_pread(ta->ph, th->th_thread + ta->thread_off_event_mask,
479 		&info->ti_events, sizeof(td_thr_events_t));
480 	if (ret != 0)
481 		return (P2T(ret));
482 	ret = ps_pread(ta->ph, th->th_thread + ta->thread_off_tcb,
483 		&info->ti_tls, sizeof(void *));
484 	info->ti_lid = th->th_tid;
485 	info->ti_tid = th->th_tid;
486 	info->ti_thread = th->th_thread;
487 	info->ti_ta_p = th->th_ta;
488 	ret = ps_linfo(ta->ph, th->th_tid, &linfo);
489 	if (ret == PS_OK) {
490 		info->ti_sigmask = linfo.pl_sigmask;
491 		info->ti_pending = linfo.pl_siglist;
492 	} else
493 		return (ret);
494 	if (state == ta->thread_state_running)
495 		info->ti_state = TD_THR_RUN;
496 	else if (state == ta->thread_state_zoombie)
497 		info->ti_state = TD_THR_ZOMBIE;
498 	else
499 		info->ti_state = TD_THR_SLEEP;
500 	info->ti_type = TD_THR_USER;
501 	return (0);
502 }
503 
504 #ifdef __i386__
505 static td_err_e
506 pt_thr_getxmmregs(const td_thrhandle_t *th, char *fxsave)
507 {
508 	const td_thragent_t *ta = th->th_ta;
509 	int ret;
510 
511 	TDBG_FUNC();
512 
513 	ret = pt_validate(th);
514 	if (ret)
515 		return (ret);
516 
517 	ret = ps_lgetxmmregs(ta->ph, th->th_tid, fxsave);
518 	return (P2T(ret));
519 }
520 #endif
521 
522 static td_err_e
523 pt_thr_getfpregs(const td_thrhandle_t *th, prfpregset_t *fpregs)
524 {
525 	const td_thragent_t *ta = th->th_ta;
526 	int ret;
527 
528 	TDBG_FUNC();
529 
530 	ret = pt_validate(th);
531 	if (ret)
532 		return (ret);
533 
534 	ret = ps_lgetfpregs(ta->ph, th->th_tid, fpregs);
535 	return (P2T(ret));
536 }
537 
538 static td_err_e
539 pt_thr_getgregs(const td_thrhandle_t *th, prgregset_t gregs)
540 {
541 	const td_thragent_t *ta = th->th_ta;
542 	int ret;
543 
544 	TDBG_FUNC();
545 
546 	ret = pt_validate(th);
547 	if (ret)
548 		return (ret);
549 
550 	ret = ps_lgetregs(ta->ph, th->th_tid, gregs);
551 	return (P2T(ret));
552 }
553 
554 #ifdef __i386__
555 static td_err_e
556 pt_thr_setxmmregs(const td_thrhandle_t *th, const char *fxsave)
557 {
558 	const td_thragent_t *ta = th->th_ta;
559 	int ret;
560 
561 	TDBG_FUNC();
562 
563 	ret = pt_validate(th);
564 	if (ret)
565 		return (ret);
566 
567 	ret = ps_lsetxmmregs(ta->ph, th->th_tid, fxsave);
568 	return (P2T(ret));
569 }
570 #endif
571 
572 static td_err_e
573 pt_thr_setfpregs(const td_thrhandle_t *th, const prfpregset_t *fpregs)
574 {
575 	const td_thragent_t *ta = th->th_ta;
576 	int ret;
577 
578 	TDBG_FUNC();
579 
580 	ret = pt_validate(th);
581 	if (ret)
582 		return (ret);
583 
584 	ret = ps_lsetfpregs(ta->ph, th->th_tid, fpregs);
585 	return (P2T(ret));
586 }
587 
588 static td_err_e
589 pt_thr_setgregs(const td_thrhandle_t *th, const prgregset_t gregs)
590 {
591 	const td_thragent_t *ta = th->th_ta;
592 	int ret;
593 
594 	TDBG_FUNC();
595 
596 	ret = pt_validate(th);
597 	if (ret)
598 		return (ret);
599 
600 	ret = ps_lsetregs(ta->ph, th->th_tid, gregs);
601 	return (P2T(ret));
602 }
603 
604 static td_err_e
605 pt_thr_event_enable(const td_thrhandle_t *th, int en)
606 {
607 	const td_thragent_t *ta = th->th_ta;
608 	int ret;
609 
610 	TDBG_FUNC();
611 	ret = ps_pwrite(ta->ph, th->th_thread + ta->thread_off_report_events,
612 		&en, sizeof(int));
613 	return (P2T(ret));
614 }
615 
616 static td_err_e
617 pt_thr_set_event(const td_thrhandle_t *th, td_thr_events_t *setp)
618 {
619 	const td_thragent_t *ta = th->th_ta;
620 	td_thr_events_t mask;
621 	int ret;
622 
623 	TDBG_FUNC();
624 	ret = ps_pread(ta->ph, th->th_thread + ta->thread_off_event_mask,
625 			&mask, sizeof(mask));
626 	mask |= *setp;
627 	ret = ps_pwrite(ta->ph, th->th_thread + ta->thread_off_event_mask,
628 			&mask, sizeof(mask));
629 	return (P2T(ret));
630 }
631 
632 static td_err_e
633 pt_thr_clear_event(const td_thrhandle_t *th, td_thr_events_t *setp)
634 {
635 	const td_thragent_t *ta = th->th_ta;
636 	td_thr_events_t mask;
637 	int ret;
638 
639 	TDBG_FUNC();
640 	ret = ps_pread(ta->ph, th->th_thread + ta->thread_off_event_mask,
641 			&mask, sizeof(mask));
642 	mask &= ~*setp;
643 	ret = ps_pwrite(ta->ph, th->th_thread + ta->thread_off_event_mask,
644 			&mask, sizeof(mask));
645 	return (P2T(ret));
646 }
647 
648 static td_err_e
649 pt_thr_event_getmsg(const td_thrhandle_t *th, td_event_msg_t *msg)
650 {
651 	static td_thrhandle_t handle;
652 	const td_thragent_t *ta = th->th_ta;
653 	psaddr_t pt, pt_temp;
654 	int32_t lwp;
655 	int ret;
656 	td_thr_events_e	tmp;
657 
658 	TDBG_FUNC();
659 	pt = th->th_thread;
660 	ret = thr_pread_ptr(ta, ta->thread_last_event_addr, &pt_temp);
661 	if (ret != 0)
662 		return (TD_ERR);
663 	/* Get event */
664 	ret = ps_pread(ta->ph, pt + ta->thread_off_event_buf, msg, sizeof(*msg));
665 	if (ret != 0)
666 		return (P2T(ret));
667 	if (msg->event == 0)
668 		return (TD_NOMSG);
669 	/*
670 	 * Take the event pointer, at the time, libthr only reports event
671 	 * once a time, so it is not a link list.
672 	 */
673 	if (pt == pt_temp)
674 		thr_pwrite_ptr(ta, ta->thread_last_event_addr, 0);
675 
676 	/* Clear event */
677 	tmp = 0;
678 	ps_pwrite(ta->ph, pt + ta->thread_off_event_buf, &tmp, sizeof(tmp));
679 	/* Convert event */
680 	pt = msg->th_p;
681 	ret = thr_pread_int(ta, pt + ta->thread_off_tid, &lwp);
682 	if (ret != 0)
683 		return (TD_ERR);
684 	handle.th_ta = ta;
685 	handle.th_tid = lwp;
686 	handle.th_thread = pt;
687 	msg->th_p = (uintptr_t)&handle;
688 	return (0);
689 }
690 
691 static td_err_e
692 pt_thr_sstep(const td_thrhandle_t *th, int step __unused)
693 {
694 	TDBG_FUNC();
695 
696 	return pt_validate(th);
697 }
698 
699 static int
700 pt_validate(const td_thrhandle_t *th)
701 {
702 
703 	if (th->th_tid == 0 || th->th_thread == 0)
704 		return (TD_ERR);
705 	return (TD_OK);
706 }
707 
708 static td_err_e
709 pt_thr_tls_get_addr(const td_thrhandle_t *th, psaddr_t _linkmap, size_t offset,
710     psaddr_t *address)
711 {
712 	const td_thragent_t *ta = th->th_ta;
713 	psaddr_t dtv_addr, obj_entry, tcb_addr;
714 	int tls_index, ret;
715 
716 	/* linkmap is a member of Obj_Entry */
717 	obj_entry = _linkmap - ta->thread_off_linkmap;
718 
719 	/* get tlsindex of the object file */
720 	ret = ps_pread(ta->ph,
721 		obj_entry + ta->thread_off_tlsindex,
722 		&tls_index, sizeof(tls_index));
723 	if (ret != 0)
724 		return (P2T(ret));
725 
726 	/* get thread tcb */
727 	ret = ps_pread(ta->ph, th->th_thread + ta->thread_off_tcb,
728 		&tcb_addr, sizeof(tcb_addr));
729 	if (ret != 0)
730 		return (P2T(ret));
731 
732 	/* get dtv array address */
733 	ret = ps_pread(ta->ph, tcb_addr + ta->thread_off_dtv,
734 		&dtv_addr, sizeof(dtv_addr));
735 	if (ret != 0)
736 		return (P2T(ret));
737 	/* now get the object's tls block base address */
738 	ret = ps_pread(ta->ph, dtv_addr + sizeof(void *) * (tls_index+1),
739 	    address, sizeof(*address));
740 	if (ret != 0)
741 		return (P2T(ret));
742 
743 	*address += offset;
744 	return (TD_OK);
745 }
746 
747 struct ta_ops libthr_db_ops = {
748 	.to_init		= pt_init,
749 	.to_ta_clear_event	= pt_ta_clear_event,
750 	.to_ta_delete		= pt_ta_delete,
751 	.to_ta_event_addr	= pt_ta_event_addr,
752 	.to_ta_event_getmsg	= pt_ta_event_getmsg,
753 	.to_ta_map_id2thr	= pt_ta_map_id2thr,
754 	.to_ta_map_lwp2thr	= pt_ta_map_lwp2thr,
755 	.to_ta_new		= pt_ta_new,
756 	.to_ta_set_event	= pt_ta_set_event,
757 	.to_ta_thr_iter		= pt_ta_thr_iter,
758 	.to_ta_tsd_iter		= pt_ta_tsd_iter,
759 	.to_thr_clear_event	= pt_thr_clear_event,
760 	.to_thr_dbresume	= pt_thr_dbresume,
761 	.to_thr_dbsuspend	= pt_thr_dbsuspend,
762 	.to_thr_event_enable	= pt_thr_event_enable,
763 	.to_thr_event_getmsg	= pt_thr_event_getmsg,
764 	.to_thr_get_info	= pt_thr_get_info,
765 	.to_thr_getfpregs	= pt_thr_getfpregs,
766 	.to_thr_getgregs	= pt_thr_getgregs,
767 	.to_thr_set_event	= pt_thr_set_event,
768 	.to_thr_setfpregs	= pt_thr_setfpregs,
769 	.to_thr_setgregs	= pt_thr_setgregs,
770 	.to_thr_validate	= pt_thr_validate,
771 	.to_thr_tls_get_addr	= pt_thr_tls_get_addr,
772 
773 	/* FreeBSD specific extensions. */
774 	.to_thr_sstep		= pt_thr_sstep,
775 #ifdef __i386__
776 	.to_thr_getxmmregs	= pt_thr_getxmmregs,
777 	.to_thr_setxmmregs	= pt_thr_setxmmregs,
778 #endif
779 };
780 
781 DATA_SET(__ta_ops, libthr_db_ops);
782