xref: /freebsd-src/lib/libthr/thread/thr_syscalls.c (revision b2db760808f74bb53c232900091c9da801ebbfcc)
1 /*
2  * Copyright (C) 2005 David Xu <davidxu@freebsd.org>.
3  * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>.
4  * Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice(s), this list of conditions and the following disclaimer as
12  *    the first lines of this file unmodified other than the possible
13  *    addition of one or more copyright notices.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice(s), this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
20  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
23  * 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
26  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
28  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
29  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 /*
35  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
36  * All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the author nor the names of any co-contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  */
63 
64 #include "namespace.h"
65 #include <sys/types.h>
66 #include <sys/mman.h>
67 #include <sys/param.h>
68 #include <sys/select.h>
69 #include <sys/signalvar.h>
70 #include <sys/socket.h>
71 #include <sys/stat.h>
72 #include <sys/time.h>
73 #include <sys/uio.h>
74 #include <sys/wait.h>
75 #include <aio.h>
76 #include <dirent.h>
77 #include <errno.h>
78 #include <fcntl.h>
79 #include <poll.h>
80 #include <signal.h>
81 #include <stdarg.h>
82 #include <stdio.h>
83 #include <stdlib.h>
84 #include <string.h>
85 #include <termios.h>
86 #include <unistd.h>
87 #include <pthread.h>
88 #include "un-namespace.h"
89 
90 #include "thr_private.h"
91 
92 extern int	__creat(const char *, mode_t);
93 extern int	__pselect(int, fd_set *, fd_set *, fd_set *,
94 			const struct timespec *, const sigset_t *);
95 extern unsigned	__sleep(unsigned int);
96 extern int	__system(const char *);
97 extern int	__tcdrain(int);
98 extern int	__usleep(useconds_t);
99 extern pid_t	__wait(int *);
100 extern pid_t	__waitpid(pid_t, int *, int);
101 extern int	__sys_aio_suspend(const struct aiocb * const[], int,
102 			const struct timespec *);
103 extern int	__sys_accept(int, struct sockaddr *, socklen_t *);
104 extern int	__sys_connect(int, const struct sockaddr *, socklen_t);
105 extern int	__sys_fsync(int);
106 extern int	__sys_msync(void *, size_t, int);
107 extern int	__sys_pselect(int, fd_set *, fd_set *, fd_set *,
108 			const struct timespec *, const sigset_t *);
109 extern int	__sys_poll(struct pollfd *, unsigned, int);
110 extern ssize_t	__sys_recv(int, void *, size_t, int);
111 extern ssize_t	__sys_recvfrom(int, void *, size_t, int, struct sockaddr *, socklen_t *);
112 extern ssize_t	__sys_recvmsg(int, struct msghdr *, int);
113 extern int	__sys_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
114 extern int	__sys_sendfile(int, int, off_t, size_t, struct sf_hdtr *,
115 			off_t *, int);
116 extern ssize_t	__sys_sendmsg(int, const struct msghdr *, int);
117 extern ssize_t	__sys_sendto(int, const void *,size_t, int, const struct sockaddr *, socklen_t);
118 extern ssize_t	__sys_readv(int, const struct iovec *, int);
119 extern pid_t	__sys_wait4(pid_t, int *, int, struct rusage *);
120 extern ssize_t	__sys_writev(int, const struct iovec *, int);
121 
122 int	___creat(const char *, mode_t);
123 int	___pselect(int, fd_set *, fd_set *, fd_set *,
124 		const struct timespec *, const sigset_t *);
125 unsigned	___sleep(unsigned);
126 int	___system(const char *);
127 int	___tcdrain(int);
128 int	___usleep(useconds_t useconds);
129 pid_t	___wait(int *);
130 pid_t	___waitpid(pid_t, int *, int);
131 int	__accept(int, struct sockaddr *, socklen_t *);
132 int	__aio_suspend(const struct aiocb * const iocbs[], int,
133 		const struct timespec *);
134 int	__close(int);
135 int	__connect(int, const struct sockaddr *, socklen_t);
136 int	__fcntl(int, int,...);
137 #ifdef SYSCALL_COMPAT
138 extern int __fcntl_compat(int, int,...);
139 #endif
140 int	__fsync(int);
141 int	__msync(void *, size_t, int);
142 int	__nanosleep(const struct timespec *, struct timespec *);
143 int	__open(const char *, int,...);
144 int	__openat(int, const char *, int,...);
145 int	__poll(struct pollfd *, unsigned int, int);
146 ssize_t	__read(int, void *buf, size_t);
147 ssize_t	__readv(int, const struct iovec *, int);
148 ssize_t	__recvfrom(int, void *, size_t, int f, struct sockaddr *, socklen_t *);
149 ssize_t	__recvmsg(int, struct msghdr *, int);
150 int	__select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
151 ssize_t	__sendmsg(int, const struct msghdr *, int);
152 ssize_t	__sendto(int, const void *, size_t, int,
153 		const struct sockaddr *, socklen_t);
154 pid_t	__wait3(int *, int, struct rusage *);
155 pid_t	__wait4(pid_t, int *, int, struct rusage *);
156 ssize_t	__write(int, const void *, size_t);
157 ssize_t	__writev(int, const struct iovec *, int);
158 
159 __weak_reference(__accept, accept);
160 
161 /*
162  * Cancellation behavior:
163  *   If thread is canceled, no socket is created.
164  */
165 int
166 __accept(int s, struct sockaddr *addr, socklen_t *addrlen)
167 {
168 	struct pthread *curthread;
169 	int ret;
170 
171 	curthread = _get_curthread();
172 	_thr_cancel_enter_defer(curthread, 1);
173 	ret = __sys_accept(s, addr, addrlen);
174 	_thr_cancel_leave_defer(curthread, ret == -1);
175 
176  	return (ret);
177 }
178 
179 __weak_reference(__aio_suspend, aio_suspend);
180 
181 int
182 __aio_suspend(const struct aiocb * const iocbs[], int niocb, const struct
183     timespec *timeout)
184 {
185 	struct pthread *curthread = _get_curthread();
186 	int ret;
187 
188 	_thr_cancel_enter(curthread);
189 	ret = __sys_aio_suspend(iocbs, niocb, timeout);
190 	_thr_cancel_leave(curthread);
191 
192 	return (ret);
193 }
194 
195 __weak_reference(__close, close);
196 
197 /*
198  * Cancellation behavior:
199  *   According to manual of close(), the file descriptor is always deleted.
200  *   Here, thread is only canceled after the system call, so the file
201  *   descriptor is always deleted despite whether the thread is canceled
202  *   or not.
203  */
204 int
205 __close(int fd)
206 {
207 	struct pthread	*curthread = _get_curthread();
208 	int	ret;
209 
210 	_thr_cancel_enter_defer(curthread, 0);
211 	ret = __sys_close(fd);
212 	_thr_cancel_leave_defer(curthread, 1);
213 
214 	return (ret);
215 }
216 
217 __weak_reference(__connect, connect);
218 
219 /*
220  * Cancellation behavior:
221  *   If the thread is canceled, connection is not made.
222  */
223 int
224 __connect(int fd, const struct sockaddr *name, socklen_t namelen)
225 {
226 	struct pthread *curthread = _get_curthread();
227 	int ret;
228 
229 	_thr_cancel_enter_defer(curthread, 0);
230 	ret = __sys_connect(fd, name, namelen);
231 	_thr_cancel_leave_defer(curthread, ret == -1);
232 
233  	return (ret);
234 }
235 
236 __weak_reference(___creat, creat);
237 
238 /*
239  * Cancellation behavior:
240  *   If thread is canceled, file is not created.
241  */
242 int
243 ___creat(const char *path, mode_t mode)
244 {
245 	struct pthread *curthread = _get_curthread();
246 	int ret;
247 
248 	_thr_cancel_enter_defer(curthread, 1);
249 	ret = __creat(path, mode);
250 	_thr_cancel_leave_defer(curthread, ret == -1);
251 
252 	return ret;
253 }
254 
255 __weak_reference(__fcntl, fcntl);
256 
257 /*
258  * Cancellation behavior:
259  *   According to specification, only F_SETLKW is a cancellation point.
260  *   Thread is only canceled at start, or canceled if the system call
261  *   is failure, this means the function does not generate side effect
262  *   if it is canceled.
263  */
264 int
265 __fcntl(int fd, int cmd,...)
266 {
267 	struct pthread *curthread = _get_curthread();
268 	int	ret;
269 	va_list	ap;
270 
271 	va_start(ap, cmd);
272 	switch (cmd) {
273 	case F_DUPFD:
274 	case F_DUP2FD:
275 		ret = __sys_fcntl(fd, cmd, va_arg(ap, int));
276 		break;
277 	case F_SETFD:
278 	case F_SETFL:
279 		ret = __sys_fcntl(fd, cmd, va_arg(ap, int));
280 		break;
281 	case F_GETFD:
282 	case F_GETFL:
283 		ret = __sys_fcntl(fd, cmd);
284 		break;
285 	case F_OSETLKW:
286 	case F_SETLKW:
287 		_thr_cancel_enter_defer(curthread, 1);
288 #ifdef SYSCALL_COMPAT
289 		ret = __fcntl_compat(fd, cmd, va_arg(ap, void *));
290 #else
291 		ret = __sys_fcntl(fd, cmd, va_arg(ap, void *));
292 #endif
293 		_thr_cancel_leave_defer(curthread, ret == -1);
294 		break;
295 	default:
296 #ifdef SYSCALL_COMPAT
297 		ret = __fcntl_compat(fd, cmd, va_arg(ap, void *));
298 #else
299 		ret = __sys_fcntl(fd, cmd, va_arg(ap, void *));
300 #endif
301 	}
302 	va_end(ap);
303 
304 	return (ret);
305 }
306 
307 __weak_reference(__fsync, fsync);
308 
309 /*
310  * Cancellation behavior:
311  *   Thread may be canceled after system call.
312  */
313 int
314 __fsync(int fd)
315 {
316 	struct pthread *curthread = _get_curthread();
317 	int	ret;
318 
319 	_thr_cancel_enter_defer(curthread, 0);
320 	ret = __sys_fsync(fd);
321 	_thr_cancel_leave_defer(curthread, 1);
322 
323 	return (ret);
324 }
325 
326 __weak_reference(__msync, msync);
327 
328 /*
329  * Cancellation behavior:
330  *   Thread may be canceled after system call.
331  */
332 int
333 __msync(void *addr, size_t len, int flags)
334 {
335 	struct pthread *curthread = _get_curthread();
336 	int	ret;
337 
338 	_thr_cancel_enter_defer(curthread, 0);
339 	ret = __sys_msync(addr, len, flags);
340 	_thr_cancel_leave_defer(curthread, 1);
341 
342 	return ret;
343 }
344 
345 __weak_reference(__nanosleep, nanosleep);
346 
347 int
348 __nanosleep(const struct timespec *time_to_sleep,
349     struct timespec *time_remaining)
350 {
351 	struct pthread *curthread = _get_curthread();
352 	int		ret;
353 
354 	_thr_cancel_enter(curthread);
355 	ret = __sys_nanosleep(time_to_sleep, time_remaining);
356 	_thr_cancel_leave(curthread);
357 
358 	return (ret);
359 }
360 
361 __weak_reference(__open, open);
362 
363 /*
364  * Cancellation behavior:
365  *   If the thread is canceled, file is not opened.
366  */
367 int
368 __open(const char *path, int flags,...)
369 {
370 	struct pthread *curthread = _get_curthread();
371 	int	ret;
372 	int	mode = 0;
373 	va_list	ap;
374 
375 	/* Check if the file is being created: */
376 	if (flags & O_CREAT) {
377 		/* Get the creation mode: */
378 		va_start(ap, flags);
379 		mode = va_arg(ap, int);
380 		va_end(ap);
381 	}
382 
383 	_thr_cancel_enter_defer(curthread, 1);
384 	ret = __sys_open(path, flags, mode);
385 	_thr_cancel_leave_defer(curthread, ret == -1);
386 
387 	return ret;
388 }
389 
390 __weak_reference(__openat, openat);
391 
392 /*
393  * Cancellation behavior:
394  *   If the thread is canceled, file is not opened.
395  */
396 int
397 __openat(int fd, const char *path, int flags, ...)
398 {
399 	struct pthread *curthread = _get_curthread();
400 	int	ret;
401 	int	mode = 0;
402 	va_list	ap;
403 
404 
405 	/* Check if the file is being created: */
406 	if (flags & O_CREAT) {
407 		/* Get the creation mode: */
408 		va_start(ap, flags);
409 		mode = va_arg(ap, int);
410 		va_end(ap);
411 	}
412 
413 	_thr_cancel_enter_defer(curthread, 1);
414 	ret = __sys_openat(fd, path, flags, mode);
415 	_thr_cancel_leave_defer(curthread, ret == -1);
416 
417 	return ret;
418 }
419 
420 __weak_reference(__poll, poll);
421 
422 /*
423  * Cancellation behavior:
424  *   Thread may be canceled at start, but if the system call returns something,
425  *   the thread is not canceled.
426  */
427 int
428 __poll(struct pollfd *fds, unsigned int nfds, int timeout)
429 {
430 	struct pthread *curthread = _get_curthread();
431 	int ret;
432 
433 	_thr_cancel_enter_defer(curthread, 1);
434 	ret = __sys_poll(fds, nfds, timeout);
435 	_thr_cancel_leave_defer(curthread, ret == -1);
436 
437 	return ret;
438 }
439 
440 __weak_reference(___pselect, pselect);
441 
442 /*
443  * Cancellation behavior:
444  *   Thread may be canceled at start, but if the system call returns something,
445  *   the thread is not canceled.
446  */
447 int
448 ___pselect(int count, fd_set *rfds, fd_set *wfds, fd_set *efds,
449 	const struct timespec *timo, const sigset_t *mask)
450 {
451 	struct pthread *curthread = _get_curthread();
452 	int ret;
453 
454 	_thr_cancel_enter_defer(curthread, 1);
455 	ret = __sys_pselect(count, rfds, wfds, efds, timo, mask);
456 	_thr_cancel_leave_defer(curthread, ret == -1);
457 
458 	return (ret);
459 }
460 
461 __weak_reference(__read, read);
462 
463 /*
464  * Cancellation behavior:
465  *   Thread may be canceled at start, but if the system call got some data,
466  *   the thread is not canceled.
467  */
468 ssize_t
469 __read(int fd, void *buf, size_t nbytes)
470 {
471 	struct pthread *curthread = _get_curthread();
472 	ssize_t	ret;
473 
474 	_thr_cancel_enter_defer(curthread, 1);
475 	ret = __sys_read(fd, buf, nbytes);
476 	_thr_cancel_leave_defer(curthread, ret == -1);
477 
478 	return ret;
479 }
480 
481 __weak_reference(__readv, readv);
482 
483 /*
484  * Cancellation behavior:
485  *   Thread may be canceled at start, but if the system call got some data,
486  *   the thread is not canceled.
487  */
488 ssize_t
489 __readv(int fd, const struct iovec *iov, int iovcnt)
490 {
491 	struct pthread *curthread = _get_curthread();
492 	ssize_t ret;
493 
494 	_thr_cancel_enter_defer(curthread, 1);
495 	ret = __sys_readv(fd, iov, iovcnt);
496 	_thr_cancel_leave_defer(curthread, ret == -1);
497 	return ret;
498 }
499 
500 __weak_reference(__recvfrom, recvfrom);
501 
502 /*
503  * Cancellation behavior:
504  *   Thread may be canceled at start, but if the system call got some data,
505  *   the thread is not canceled.
506  */
507 ssize_t
508 __recvfrom(int s, void *b, size_t l, int f, struct sockaddr *from,
509     socklen_t *fl)
510 {
511 	struct pthread *curthread = _get_curthread();
512 	ssize_t ret;
513 
514 	_thr_cancel_enter_defer(curthread, 1);
515 	ret = __sys_recvfrom(s, b, l, f, from, fl);
516 	_thr_cancel_leave_defer(curthread, ret == -1);
517 	return (ret);
518 }
519 
520 __weak_reference(__recvmsg, recvmsg);
521 
522 /*
523  * Cancellation behavior:
524  *   Thread may be canceled at start, but if the system call got some data,
525  *   the thread is not canceled.
526  */
527 ssize_t
528 __recvmsg(int s, struct msghdr *m, int f)
529 {
530 	struct pthread *curthread = _get_curthread();
531 	ssize_t ret;
532 
533 	_thr_cancel_enter_defer(curthread, 1);
534 	ret = __sys_recvmsg(s, m, f);
535 	_thr_cancel_leave_defer(curthread, ret == -1);
536 	return (ret);
537 }
538 
539 __weak_reference(__select, select);
540 
541 /*
542  * Cancellation behavior:
543  *   Thread may be canceled at start, but if the system call returns something,
544  *   the thread is not canceled.
545  */
546 int
547 __select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
548 	struct timeval *timeout)
549 {
550 	struct pthread *curthread = _get_curthread();
551 	int ret;
552 
553 	_thr_cancel_enter_defer(curthread, 1);
554 	ret = __sys_select(numfds, readfds, writefds, exceptfds, timeout);
555 	_thr_cancel_leave_defer(curthread, ret == -1);
556 	return ret;
557 }
558 
559 __weak_reference(__sendmsg, sendmsg);
560 
561 /*
562  * Cancellation behavior:
563  *   Thread may be canceled at start, but if the system call sent
564  *   data, the thread is not canceled.
565  */
566 ssize_t
567 __sendmsg(int s, const struct msghdr *m, int f)
568 {
569 	struct pthread *curthread = _get_curthread();
570 	ssize_t ret;
571 
572 	_thr_cancel_enter_defer(curthread, 1);
573 	ret = __sys_sendmsg(s, m, f);
574 	_thr_cancel_leave_defer(curthread, ret <= 0);
575 	return (ret);
576 }
577 
578 __weak_reference(__sendto, sendto);
579 
580 /*
581  * Cancellation behavior:
582  *   Thread may be canceled at start, but if the system call sent some
583  *   data, the thread is not canceled.
584  */
585 ssize_t
586 __sendto(int s, const void *m, size_t l, int f, const struct sockaddr *t,
587     socklen_t tl)
588 {
589 	struct pthread *curthread = _get_curthread();
590 	ssize_t ret;
591 
592 	_thr_cancel_enter_defer(curthread, 1);
593 	ret = __sys_sendto(s, m, l, f, t, tl);
594 	_thr_cancel_leave_defer(curthread, ret <= 0);
595 	return (ret);
596 }
597 
598 __weak_reference(___sleep, sleep);
599 
600 unsigned int
601 ___sleep(unsigned int seconds)
602 {
603 	struct pthread *curthread = _get_curthread();
604 	unsigned int	ret;
605 
606 	_thr_cancel_enter(curthread);
607 	ret = __sleep(seconds);
608 	_thr_cancel_leave(curthread);
609 
610 	return (ret);
611 }
612 
613 __weak_reference(___system, system);
614 
615 int
616 ___system(const char *string)
617 {
618 	struct pthread *curthread = _get_curthread();
619 	int	ret;
620 
621 	_thr_cancel_enter(curthread);
622 	ret = __system(string);
623 	_thr_cancel_leave(curthread);
624 
625 	return ret;
626 }
627 
628 __weak_reference(___tcdrain, tcdrain);
629 
630 /*
631  * Cancellation behavior:
632  *   If thread is canceled, the system call is not completed,
633  *   this means not all bytes were drained.
634  */
635 int
636 ___tcdrain(int fd)
637 {
638 	struct pthread *curthread = _get_curthread();
639 	int	ret;
640 
641 	_thr_cancel_enter_defer(curthread, 1);
642 	ret = __tcdrain(fd);
643 	_thr_cancel_leave_defer(curthread, ret == -1);
644 	return (ret);
645 }
646 
647 __weak_reference(___usleep, usleep);
648 
649 int
650 ___usleep(useconds_t useconds)
651 {
652 	struct pthread *curthread = _get_curthread();
653 	int		ret;
654 
655 	_thr_cancel_enter(curthread);
656 	ret = __usleep(useconds);
657 	_thr_cancel_leave(curthread);
658 
659 	return (ret);
660 }
661 
662 __weak_reference(___wait, wait);
663 
664 /*
665  * Cancellation behavior:
666  *   Thread may be canceled at start, but if the system call returns
667  *   a child pid, the thread is not canceled.
668  */
669 pid_t
670 ___wait(int *istat)
671 {
672 	struct pthread *curthread = _get_curthread();
673 	pid_t	ret;
674 
675 	_thr_cancel_enter_defer(curthread, 1);
676 	ret = __wait(istat);
677 	_thr_cancel_leave_defer(curthread, ret <= 0);
678 
679 	return ret;
680 }
681 
682 __weak_reference(__wait3, wait3);
683 
684 /*
685  * Cancellation behavior:
686  *   Thread may be canceled at start, but if the system call returns
687  *   a child pid, the thread is not canceled.
688  */
689 pid_t
690 __wait3(int *status, int options, struct rusage *rusage)
691 {
692 	struct pthread *curthread = _get_curthread();
693 	pid_t ret;
694 
695 	_thr_cancel_enter_defer(curthread, 1);
696 	ret = _wait4(WAIT_ANY, status, options, rusage);
697 	_thr_cancel_leave_defer(curthread, ret <= 0);
698 
699 	return (ret);
700 }
701 
702 __weak_reference(__wait4, wait4);
703 
704 /*
705  * Cancellation behavior:
706  *   Thread may be canceled at start, but if the system call returns
707  *   a child pid, the thread is not canceled.
708  */
709 pid_t
710 __wait4(pid_t pid, int *status, int options, struct rusage *rusage)
711 {
712 	struct pthread *curthread = _get_curthread();
713 	pid_t ret;
714 
715 	_thr_cancel_enter_defer(curthread, 1);
716 	ret = __sys_wait4(pid, status, options, rusage);
717 	_thr_cancel_leave_defer(curthread, ret <= 0);
718 
719 	return ret;
720 }
721 
722 __weak_reference(___waitpid, waitpid);
723 
724 /*
725  * Cancellation behavior:
726  *   Thread may be canceled at start, but if the system call returns
727  *   a child pid, the thread is not canceled.
728  */
729 pid_t
730 ___waitpid(pid_t wpid, int *status, int options)
731 {
732 	struct pthread *curthread = _get_curthread();
733 	pid_t	ret;
734 
735 	_thr_cancel_enter_defer(curthread, 1);
736 	ret = __waitpid(wpid, status, options);
737 	_thr_cancel_leave_defer(curthread, ret <= 0);
738 
739 	return ret;
740 }
741 
742 __weak_reference(__write, write);
743 
744 /*
745  * Cancellation behavior:
746  *   Thread may be canceled at start, but if the thread wrote some data,
747  *   it is not canceled.
748  */
749 ssize_t
750 __write(int fd, const void *buf, size_t nbytes)
751 {
752 	struct pthread *curthread = _get_curthread();
753 	ssize_t	ret;
754 
755 	_thr_cancel_enter_defer(curthread, 1);
756 	ret = __sys_write(fd, buf, nbytes);
757 	_thr_cancel_leave_defer(curthread, (ret <= 0));
758 	return ret;
759 }
760 
761 __weak_reference(__writev, writev);
762 
763 /*
764  * Cancellation behavior:
765  *   Thread may be canceled at start, but if the thread wrote some data,
766  *   it is not canceled.
767  */
768 ssize_t
769 __writev(int fd, const struct iovec *iov, int iovcnt)
770 {
771 	struct pthread *curthread = _get_curthread();
772 	ssize_t ret;
773 
774 	_thr_cancel_enter_defer(curthread, 1);
775 	ret = __sys_writev(fd, iov, iovcnt);
776 	_thr_cancel_leave_defer(curthread, (ret <= 0));
777 	return ret;
778 }
779