xref: /freebsd/lib/libthr/thread/thr_syscalls.c (revision 28f42739a547ffe0b5dfaaf9f49fb4c4813aa232)
1 /*
2  * Copyright (c) 2014 The FreeBSD Foundation.
3  * Copyright (C) 2005 David Xu <davidxu@freebsd.org>.
4  * Copyright (c) 2003 Daniel Eischen <deischen@freebsd.org>.
5  * Copyright (C) 2000 Jason Evans <jasone@freebsd.org>.
6  * All rights reserved.
7  *
8  * Portions of this software were developed by Konstantin Belousov
9  * under sponsorship from the FreeBSD Foundation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice(s), this list of conditions and the following disclaimer as
16  *    the first lines of this file unmodified other than the possible
17  *    addition of one or more copyright notices.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice(s), this list of conditions and the following disclaimer in
20  *    the documentation and/or other materials provided with the
21  *    distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
24  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE
27  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
31  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
32  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
33  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /*
37  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
38  * All rights reserved.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  * 3. Neither the name of the author nor the names of any co-contributors
49  *    may be used to endorse or promote products derived from this software
50  *    without specific prior written permission.
51  *
52  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62  * SUCH DAMAGE.
63  *
64  */
65 
66 #include <sys/cdefs.h>
67 __FBSDID("$FreeBSD$");
68 
69 #include "namespace.h"
70 #include <sys/types.h>
71 #include <sys/mman.h>
72 #include <sys/param.h>
73 #include <sys/select.h>
74 #include <sys/signalvar.h>
75 #include <sys/socket.h>
76 #include <sys/stat.h>
77 #include <sys/time.h>
78 #include <sys/uio.h>
79 #include <sys/wait.h>
80 #include <aio.h>
81 #include <dirent.h>
82 #include <errno.h>
83 #include <fcntl.h>
84 #include <poll.h>
85 #include <signal.h>
86 #include <stdarg.h>
87 #include <stdio.h>
88 #include <stdlib.h>
89 #include <string.h>
90 #include <termios.h>
91 #include <unistd.h>
92 #include <pthread.h>
93 #include "un-namespace.h"
94 
95 #include "libc_private.h"
96 #include "thr_private.h"
97 
98 #ifdef SYSCALL_COMPAT
99 extern int __fcntl_compat(int, int, ...);
100 #endif
101 
102 /*
103  * Cancellation behavior:
104  *   If thread is canceled, no socket is created.
105  */
106 static int
107 __thr_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
108 {
109 	struct pthread *curthread;
110 	int ret;
111 
112 	curthread = _get_curthread();
113 	_thr_cancel_enter(curthread);
114 	ret = __sys_accept(s, addr, addrlen);
115 	_thr_cancel_leave(curthread, ret == -1);
116 
117  	return (ret);
118 }
119 
120 /*
121  * Cancellation behavior:
122  *   If thread is canceled, no socket is created.
123  */
124 static int
125 __thr_accept4(int s, struct sockaddr *addr, socklen_t *addrlen, int flags)
126 {
127 	struct pthread *curthread;
128 	int ret;
129 
130 	curthread = _get_curthread();
131 	_thr_cancel_enter(curthread);
132 	ret = __sys_accept4(s, addr, addrlen, flags);
133 	_thr_cancel_leave(curthread, ret == -1);
134 
135  	return (ret);
136 }
137 
138 static int
139 __thr_aio_suspend(const struct aiocb * const iocbs[], int niocb, const struct
140     timespec *timeout)
141 {
142 	struct pthread *curthread;
143 	int ret;
144 
145 	curthread = _get_curthread();
146 	_thr_cancel_enter(curthread);
147 	ret = __sys_aio_suspend(iocbs, niocb, timeout);
148 	_thr_cancel_leave(curthread, 1);
149 
150 	return (ret);
151 }
152 
153 /*
154  * Cancellation behavior:
155  *   According to manual of close(), the file descriptor is always deleted.
156  *   Here, thread is only canceled after the system call, so the file
157  *   descriptor is always deleted despite whether the thread is canceled
158  *   or not.
159  */
160 static int
161 __thr_close(int fd)
162 {
163 	struct pthread *curthread;
164 	int ret;
165 
166 	curthread = _get_curthread();
167 	_thr_cancel_enter2(curthread, 0);
168 	ret = __sys_close(fd);
169 	_thr_cancel_leave(curthread, 1);
170 
171 	return (ret);
172 }
173 
174 /*
175  * Cancellation behavior:
176  *   If the thread is canceled, connection is not made.
177  */
178 static int
179 __thr_connect(int fd, const struct sockaddr *name, socklen_t namelen)
180 {
181 	struct pthread *curthread;
182 	int ret;
183 
184 	curthread = _get_curthread();
185 	_thr_cancel_enter(curthread);
186 	ret = __sys_connect(fd, name, namelen);
187 	_thr_cancel_leave(curthread, ret == -1);
188 
189  	return (ret);
190 }
191 
192 
193 /*
194  * Cancellation behavior:
195  *   If thread is canceled, file is not created.
196  */
197 static int
198 __thr_creat(const char *path, mode_t mode)
199 {
200 	struct pthread *curthread;
201 	int ret;
202 
203 	curthread = _get_curthread();
204 	_thr_cancel_enter(curthread);
205 	ret = __libc_creat(path, mode);
206 	_thr_cancel_leave(curthread, ret == -1);
207 
208 	return (ret);
209 }
210 
211 /*
212  * Cancellation behavior:
213  *   According to specification, only F_SETLKW is a cancellation point.
214  *   Thread is only canceled at start, or canceled if the system call
215  *   is failure, this means the function does not generate side effect
216  *   if it is canceled.
217  */
218 static int
219 __thr_fcntl(int fd, int cmd, ...)
220 {
221 	struct pthread *curthread;
222 	int ret;
223 	va_list	ap;
224 
225 	curthread = _get_curthread();
226 	va_start(ap, cmd);
227 	if (cmd == F_OSETLKW || cmd == F_SETLKW) {
228 		_thr_cancel_enter(curthread);
229 #ifdef SYSCALL_COMPAT
230 		ret = __fcntl_compat(fd, cmd, va_arg(ap, void *));
231 #else
232 		ret = __sys_fcntl(fd, cmd, va_arg(ap, void *));
233 #endif
234 		_thr_cancel_leave(curthread, ret == -1);
235 	} else {
236 #ifdef SYSCALL_COMPAT
237 		ret = __fcntl_compat(fd, cmd, va_arg(ap, void *));
238 #else
239 		ret = __sys_fcntl(fd, cmd, va_arg(ap, void *));
240 #endif
241 	}
242 	va_end(ap);
243 
244 	return (ret);
245 }
246 
247 /*
248  * Cancellation behavior:
249  *   Thread may be canceled after system call.
250  */
251 static int
252 __thr_fsync(int fd)
253 {
254 	struct pthread *curthread;
255 	int ret;
256 
257 	curthread = _get_curthread();
258 	_thr_cancel_enter2(curthread, 0);
259 	ret = __sys_fsync(fd);
260 	_thr_cancel_leave(curthread, 1);
261 
262 	return (ret);
263 }
264 
265 /*
266  * Cancellation behavior:
267  *   Thread may be canceled after system call.
268  */
269 static int
270 __thr_msync(void *addr, size_t len, int flags)
271 {
272 	struct pthread *curthread;
273 	int ret;
274 
275 	curthread = _get_curthread();
276 	_thr_cancel_enter2(curthread, 0);
277 	ret = __sys_msync(addr, len, flags);
278 	_thr_cancel_leave(curthread, 1);
279 
280 	return (ret);
281 }
282 
283 static int
284 __thr_nanosleep(const struct timespec *time_to_sleep,
285     struct timespec *time_remaining)
286 {
287 	struct pthread *curthread;
288 	int ret;
289 
290 	curthread = _get_curthread();
291 	_thr_cancel_enter(curthread);
292 	ret = __sys_nanosleep(time_to_sleep, time_remaining);
293 	_thr_cancel_leave(curthread, 1);
294 
295 	return (ret);
296 }
297 
298 /*
299  * Cancellation behavior:
300  *   If the thread is canceled, file is not opened.
301  */
302 static int
303 __thr_open(const char *path, int flags,...)
304 {
305 	struct pthread *curthread;
306 	int mode, ret;
307 	va_list	ap;
308 
309 	/* Check if the file is being created: */
310 	if ((flags & O_CREAT) != 0) {
311 		/* Get the creation mode: */
312 		va_start(ap, flags);
313 		mode = va_arg(ap, int);
314 		va_end(ap);
315 	} else {
316 		mode = 0;
317 	}
318 
319 	curthread = _get_curthread();
320 	_thr_cancel_enter(curthread);
321 	ret = __sys_open(path, flags, mode);
322 	_thr_cancel_leave(curthread, ret == -1);
323 
324 	return (ret);
325 }
326 
327 /*
328  * Cancellation behavior:
329  *   If the thread is canceled, file is not opened.
330  */
331 static int
332 __thr_openat(int fd, const char *path, int flags, ...)
333 {
334 	struct pthread *curthread;
335 	int mode, ret;
336 	va_list	ap;
337 
338 
339 	/* Check if the file is being created: */
340 	if ((flags & O_CREAT) != 0) {
341 		/* Get the creation mode: */
342 		va_start(ap, flags);
343 		mode = va_arg(ap, int);
344 		va_end(ap);
345 	} else {
346 		mode = 0;
347 	}
348 
349 	curthread = _get_curthread();
350 	_thr_cancel_enter(curthread);
351 	ret = __sys_openat(fd, path, flags, mode);
352 	_thr_cancel_leave(curthread, ret == -1);
353 
354 	return (ret);
355 }
356 
357 /*
358  * Cancellation behavior:
359  *   Thread may be canceled at start, but if the system call returns something,
360  *   the thread is not canceled.
361  */
362 static int
363 __thr_poll(struct pollfd *fds, unsigned int nfds, int timeout)
364 {
365 	struct pthread *curthread;
366 	int ret;
367 
368 	curthread = _get_curthread();
369 	_thr_cancel_enter(curthread);
370 	ret = __sys_poll(fds, nfds, timeout);
371 	_thr_cancel_leave(curthread, ret == -1);
372 
373 	return (ret);
374 }
375 
376 /*
377  * Cancellation behavior:
378  *   Thread may be canceled at start, but if the system call returns something,
379  *   the thread is not canceled.
380  */
381 static int
382 __thr_pselect(int count, fd_set *rfds, fd_set *wfds, fd_set *efds,
383 	const struct timespec *timo, const sigset_t *mask)
384 {
385 	struct pthread *curthread;
386 	int ret;
387 
388 	curthread = _get_curthread();
389 	_thr_cancel_enter(curthread);
390 	ret = __sys_pselect(count, rfds, wfds, efds, timo, mask);
391 	_thr_cancel_leave(curthread, ret == -1);
392 
393 	return (ret);
394 }
395 
396 /*
397  * Cancellation behavior:
398  *   Thread may be canceled at start, but if the system call got some data,
399  *   the thread is not canceled.
400  */
401 static ssize_t
402 __thr_read(int fd, void *buf, size_t nbytes)
403 {
404 	struct pthread *curthread;
405 	ssize_t	ret;
406 
407 	curthread = _get_curthread();
408 	_thr_cancel_enter(curthread);
409 	ret = __sys_read(fd, buf, nbytes);
410 	_thr_cancel_leave(curthread, ret == -1);
411 
412 	return (ret);
413 }
414 
415 /*
416  * Cancellation behavior:
417  *   Thread may be canceled at start, but if the system call got some data,
418  *   the thread is not canceled.
419  */
420 static ssize_t
421 __thr_readv(int fd, const struct iovec *iov, int iovcnt)
422 {
423 	struct pthread *curthread;
424 	ssize_t ret;
425 
426 	curthread = _get_curthread();
427 	_thr_cancel_enter(curthread);
428 	ret = __sys_readv(fd, iov, iovcnt);
429 	_thr_cancel_leave(curthread, ret == -1);
430 	return (ret);
431 }
432 
433 /*
434  * Cancellation behavior:
435  *   Thread may be canceled at start, but if the system call got some data,
436  *   the thread is not canceled.
437  */
438 static ssize_t
439 __thr_recvfrom(int s, void *b, size_t l, int f, struct sockaddr *from,
440     socklen_t *fl)
441 {
442 	struct pthread *curthread;
443 	ssize_t ret;
444 
445 	curthread = _get_curthread();
446 	_thr_cancel_enter(curthread);
447 	ret = __sys_recvfrom(s, b, l, f, from, fl);
448 	_thr_cancel_leave(curthread, ret == -1);
449 	return (ret);
450 }
451 
452 /*
453  * Cancellation behavior:
454  *   Thread may be canceled at start, but if the system call got some data,
455  *   the thread is not canceled.
456  */
457 static ssize_t
458 __thr_recvmsg(int s, struct msghdr *m, int f)
459 {
460 	struct pthread *curthread;
461 	ssize_t ret;
462 
463 	curthread = _get_curthread();
464 	_thr_cancel_enter(curthread);
465 	ret = __sys_recvmsg(s, m, f);
466 	_thr_cancel_leave(curthread, ret == -1);
467 	return (ret);
468 }
469 
470 /*
471  * Cancellation behavior:
472  *   Thread may be canceled at start, but if the system call returns something,
473  *   the thread is not canceled.
474  */
475 static int
476 __thr_select(int numfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
477 	struct timeval *timeout)
478 {
479 	struct pthread *curthread;
480 	int ret;
481 
482 	curthread = _get_curthread();
483 	_thr_cancel_enter(curthread);
484 	ret = __sys_select(numfds, readfds, writefds, exceptfds, timeout);
485 	_thr_cancel_leave(curthread, ret == -1);
486 	return (ret);
487 }
488 
489 /*
490  * Cancellation behavior:
491  *   Thread may be canceled at start, but if the system call sent
492  *   data, the thread is not canceled.
493  */
494 static ssize_t
495 __thr_sendmsg(int s, const struct msghdr *m, int f)
496 {
497 	struct pthread *curthread;
498 	ssize_t ret;
499 
500 	curthread = _get_curthread();
501 	_thr_cancel_enter(curthread);
502 	ret = __sys_sendmsg(s, m, f);
503 	_thr_cancel_leave(curthread, ret <= 0);
504 	return (ret);
505 }
506 
507 /*
508  * Cancellation behavior:
509  *   Thread may be canceled at start, but if the system call sent some
510  *   data, the thread is not canceled.
511  */
512 static ssize_t
513 __thr_sendto(int s, const void *m, size_t l, int f, const struct sockaddr *t,
514     socklen_t tl)
515 {
516 	struct pthread *curthread;
517 	ssize_t ret;
518 
519 	curthread = _get_curthread();
520 	_thr_cancel_enter(curthread);
521 	ret = __sys_sendto(s, m, l, f, t, tl);
522 	_thr_cancel_leave(curthread, ret <= 0);
523 	return (ret);
524 }
525 
526 static unsigned int
527 __thr_sleep(unsigned int seconds)
528 {
529 	struct pthread *curthread;
530 	unsigned int ret;
531 
532 	curthread = _get_curthread();
533 	_thr_cancel_enter(curthread);
534 	ret = __libc_sleep(seconds);
535 	_thr_cancel_leave(curthread, 1);
536 	return (ret);
537 }
538 
539 static int
540 __thr_system(const char *string)
541 {
542 	struct pthread *curthread;
543 	int ret;
544 
545 	curthread = _get_curthread();
546 	_thr_cancel_enter(curthread);
547 	ret = __libc_system(string);
548 	_thr_cancel_leave(curthread, 1);
549 	return (ret);
550 }
551 
552 /*
553  * Cancellation behavior:
554  *   If thread is canceled, the system call is not completed,
555  *   this means not all bytes were drained.
556  */
557 static int
558 __thr_tcdrain(int fd)
559 {
560 	struct pthread *curthread;
561 	int ret;
562 
563 	curthread = _get_curthread();
564 	_thr_cancel_enter(curthread);
565 	ret = __libc_tcdrain(fd);
566 	_thr_cancel_leave(curthread, ret == -1);
567 	return (ret);
568 }
569 
570 static int
571 __thr_usleep(useconds_t useconds)
572 {
573 	struct pthread *curthread;
574 	int ret;
575 
576 	curthread = _get_curthread();
577 	_thr_cancel_enter(curthread);
578 	ret = __libc_usleep(useconds);
579 	_thr_cancel_leave(curthread, 1);
580 	return (ret);
581 }
582 
583 /*
584  * Cancellation behavior:
585  *   Thread may be canceled at start, but if the system call returns
586  *   a child pid, the thread is not canceled.
587  */
588 static pid_t
589 __thr_wait(int *istat)
590 {
591 	struct pthread *curthread;
592 	pid_t ret;
593 
594 	curthread = _get_curthread();
595 	_thr_cancel_enter(curthread);
596 	ret = __libc_wait(istat);
597 	_thr_cancel_leave(curthread, ret <= 0);
598 	return (ret);
599 }
600 
601 /*
602  * Cancellation behavior:
603  *   Thread may be canceled at start, but if the system call returns
604  *   a child pid, the thread is not canceled.
605  */
606 static pid_t
607 __thr_wait3(int *status, int options, struct rusage *rusage)
608 {
609 	struct pthread *curthread;
610 	pid_t ret;
611 
612 	curthread = _get_curthread();
613 	_thr_cancel_enter(curthread);
614 	ret = __libc_wait3(status, options, rusage);
615 	_thr_cancel_leave(curthread, ret <= 0);
616 	return (ret);
617 }
618 
619 /*
620  * Cancellation behavior:
621  *   Thread may be canceled at start, but if the system call returns
622  *   a child pid, the thread is not canceled.
623  */
624 static pid_t
625 __thr_wait4(pid_t pid, int *status, int options, struct rusage *rusage)
626 {
627 	struct pthread *curthread;
628 	pid_t ret;
629 
630 	curthread = _get_curthread();
631 	_thr_cancel_enter(curthread);
632 	ret = __sys_wait4(pid, status, options, rusage);
633 	_thr_cancel_leave(curthread, ret <= 0);
634 	return (ret);
635 }
636 
637 /*
638  * Cancellation behavior:
639  *   Thread may be canceled at start, but if the system call returns
640  *   a child pid, the thread is not canceled.
641  */
642 static pid_t
643 __thr_waitpid(pid_t wpid, int *status, int options)
644 {
645 	struct pthread *curthread;
646 	pid_t ret;
647 
648 	curthread = _get_curthread();
649 	_thr_cancel_enter(curthread);
650 	ret = __libc_waitpid(wpid, status, options);
651 	_thr_cancel_leave(curthread, ret <= 0);
652 	return (ret);
653 }
654 
655 /*
656  * Cancellation behavior:
657  *   Thread may be canceled at start, but if the thread wrote some data,
658  *   it is not canceled.
659  */
660 static ssize_t
661 __thr_write(int fd, const void *buf, size_t nbytes)
662 {
663 	struct pthread *curthread;
664 	ssize_t	ret;
665 
666 	curthread = _get_curthread();
667 	_thr_cancel_enter(curthread);
668 	ret = __sys_write(fd, buf, nbytes);
669 	_thr_cancel_leave(curthread, (ret <= 0));
670 	return (ret);
671 }
672 
673 /*
674  * Cancellation behavior:
675  *   Thread may be canceled at start, but if the thread wrote some data,
676  *   it is not canceled.
677  */
678 static ssize_t
679 __thr_writev(int fd, const struct iovec *iov, int iovcnt)
680 {
681 	struct pthread *curthread;
682 	ssize_t ret;
683 
684 	curthread = _get_curthread();
685 	_thr_cancel_enter(curthread);
686 	ret = __sys_writev(fd, iov, iovcnt);
687 	_thr_cancel_leave(curthread, (ret <= 0));
688 	return (ret);
689 }
690 
691 void
692 __thr_interpose_libc(void)
693 {
694 
695 	__set_error_selector(__error_threaded);
696 #define	SLOT(name)					\
697 	*(__libc_interposing_slot(INTERPOS_##name)) =	\
698 	    (interpos_func_t)__thr_##name;
699 	SLOT(accept);
700 	SLOT(accept4);
701 	SLOT(aio_suspend);
702 	SLOT(close);
703 	SLOT(connect);
704 	SLOT(creat);
705 	SLOT(fcntl);
706 	SLOT(fsync);
707 	SLOT(fork);
708 	SLOT(msync);
709 	SLOT(nanosleep);
710 	SLOT(open);
711 	SLOT(openat);
712 	SLOT(poll);
713 	SLOT(pselect);
714 	SLOT(raise);
715 	SLOT(read);
716 	SLOT(readv);
717 	SLOT(recvfrom);
718 	SLOT(recvmsg);
719 	SLOT(select);
720 	SLOT(sendmsg);
721 	SLOT(sendto);
722 	SLOT(setcontext);
723 	SLOT(sigaction);
724 	SLOT(sigprocmask);
725 	SLOT(sigsuspend);
726 	SLOT(sigwait);
727 	SLOT(sigtimedwait);
728 	SLOT(sigwaitinfo);
729 	SLOT(swapcontext);
730 	SLOT(system);
731 	SLOT(sleep);
732 	SLOT(tcdrain);
733 	SLOT(usleep);
734 	SLOT(pause);
735 	SLOT(wait);
736 	SLOT(wait3);
737 	SLOT(wait4);
738 	SLOT(waitpid);
739 	SLOT(write);
740 	SLOT(writev);
741 #undef SLOT
742 	*(__libc_interposing_slot(
743 	    INTERPOS__pthread_mutex_init_calloc_cb)) =
744 	    (interpos_func_t)_pthread_mutex_init_calloc_cb;
745 }
746