xref: /titanic_52/usr/src/lib/libc/port/threads/scalls.c (revision b6c3f7863936abeae522e48a13887dddeb691a45)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include "lint.h"
30 #include "thr_uberdata.h"
31 #include <stdarg.h>
32 #include <poll.h>
33 #include <stropts.h>
34 #include <dlfcn.h>
35 #include <wait.h>
36 #include <sys/socket.h>
37 #include <sys/uio.h>
38 #include <sys/file.h>
39 #include <sys/door.h>
40 
41 /*
42  * atfork_lock protects the pthread_atfork() data structures.
43  *
44  * fork_lock does double-duty.  Not only does it (and atfork_lock)
45  * serialize calls to fork() and forkall(), but it also serializes calls
46  * to thr_suspend() and thr_continue() (because fork() and forkall() also
47  * suspend and continue other threads and they want no competition).
48  *
49  * Functions called in dlopen()ed L10N objects can do anything, including
50  * call malloc() and free().  Such calls are not fork-safe when protected
51  * by an ordinary mutex that is acquired in libc's prefork processing
52  * because, with an interposed malloc library present, there would be a
53  * lock ordering violation due to the pthread_atfork() prefork function
54  * in the interposition library acquiring its malloc lock(s) before the
55  * ordinary mutex in libc being acquired by libc's prefork functions.
56  *
57  * Within libc, calls to malloc() and free() are fork-safe if the calls
58  * are made while holding no other libc locks.  This covers almost all
59  * of libc's malloc() and free() calls.  For those libc code paths, such
60  * as the above-mentioned L10N calls, that require serialization and that
61  * may call malloc() or free(), libc uses callout_lock_enter() to perform
62  * the serialization.  This works because callout_lock is not acquired as
63  * part of running the pthread_atfork() prefork handlers (to avoid the
64  * lock ordering violation described above).  Rather, it is simply
65  * reinitialized in postfork1_child() to cover the case that some
66  * now-defunct thread might have been suspended while holding it.
67  */
68 
69 void
70 fork_lock_enter(void)
71 {
72 	ASSERT(curthread->ul_critical == 0);
73 	(void) _private_mutex_lock(&curthread->ul_uberdata->fork_lock);
74 }
75 
76 void
77 fork_lock_exit(void)
78 {
79 	ASSERT(curthread->ul_critical == 0);
80 	(void) _private_mutex_unlock(&curthread->ul_uberdata->fork_lock);
81 }
82 
83 /*
84  * Use cancel_safe_mutex_lock() to protect against being cancelled while
85  * holding callout_lock and calling outside of libc (via L10N plugins).
86  * We will honor a pending cancellation request when callout_lock_exit()
87  * is called, by calling cancel_safe_mutex_unlock().
88  */
89 void
90 callout_lock_enter(void)
91 {
92 	ASSERT(curthread->ul_critical == 0);
93 	cancel_safe_mutex_lock(&curthread->ul_uberdata->callout_lock);
94 }
95 
96 void
97 callout_lock_exit(void)
98 {
99 	ASSERT(curthread->ul_critical == 0);
100 	cancel_safe_mutex_unlock(&curthread->ul_uberdata->callout_lock);
101 }
102 
103 #pragma weak forkx = _private_forkx
104 #pragma weak _forkx = _private_forkx
105 pid_t
106 _private_forkx(int flags)
107 {
108 	ulwp_t *self = curthread;
109 	uberdata_t *udp = self->ul_uberdata;
110 	pid_t pid;
111 
112 	if (self->ul_vfork) {
113 		/*
114 		 * We are a child of vfork(); omit all of the fork
115 		 * logic and go straight to the system call trap.
116 		 * A vfork() child of a multithreaded parent
117 		 * must never call fork().
118 		 */
119 		if (udp->uberflags.uf_mt) {
120 			errno = ENOTSUP;
121 			return (-1);
122 		}
123 		pid = __forkx(flags);
124 		if (pid == 0) {		/* child */
125 			udp->pid = _private_getpid();
126 			self->ul_vfork = 0;
127 		}
128 		return (pid);
129 	}
130 
131 	sigoff(self);
132 	if (self->ul_fork) {
133 		/*
134 		 * Cannot call fork() from a fork handler.
135 		 */
136 		sigon(self);
137 		errno = EDEADLK;
138 		return (-1);
139 	}
140 	self->ul_fork = 1;
141 
142 	/*
143 	 * The functions registered by pthread_atfork() are defined by
144 	 * the application and its libraries and we must not hold any
145 	 * internal lmutex_lock()-acquired locks while invoking them.
146 	 * We hold only udp->atfork_lock to protect the atfork linkages.
147 	 * If one of these pthread_atfork() functions attempts to fork
148 	 * or to call pthread_atfork(), libc will detect the error and
149 	 * fail the call with EDEADLK.  Otherwise, the pthread_atfork()
150 	 * functions are free to do anything they please (except they
151 	 * will not receive any signals).
152 	 */
153 	(void) _private_mutex_lock(&udp->atfork_lock);
154 	_prefork_handler();
155 
156 	/*
157 	 * Block every other thread attempting thr_suspend() or thr_continue().
158 	 */
159 	(void) _private_mutex_lock(&udp->fork_lock);
160 
161 	/*
162 	 * Block all signals.
163 	 * Just deferring them via sigoff() is not enough.
164 	 * We have to avoid taking a deferred signal in the child
165 	 * that was actually sent to the parent before __forkx().
166 	 */
167 	block_all_signals(self);
168 
169 	/*
170 	 * This suspends all threads but this one, leaving them
171 	 * suspended outside of any critical regions in the library.
172 	 * Thus, we are assured that no lmutex_lock()-acquired library
173 	 * locks are held while we invoke fork() from the current thread.
174 	 */
175 	suspend_fork();
176 
177 	pid = __forkx(flags);
178 
179 	if (pid == 0) {		/* child */
180 		/*
181 		 * Clear our schedctl pointer.
182 		 * Discard any deferred signal that was sent to the parent.
183 		 * Because we blocked all signals before __forkx(), a
184 		 * deferred signal cannot have been taken by the child.
185 		 */
186 		self->ul_schedctl_called = NULL;
187 		self->ul_schedctl = NULL;
188 		self->ul_cursig = 0;
189 		self->ul_siginfo.si_signo = 0;
190 		udp->pid = _private_getpid();
191 		/* reset the library's data structures to reflect one thread */
192 		unregister_locks();
193 		postfork1_child();
194 		restore_signals(self);
195 		(void) _private_mutex_unlock(&udp->fork_lock);
196 		_postfork_child_handler();
197 	} else {
198 		/* restart all threads that were suspended for fork() */
199 		continue_fork(0);
200 		restore_signals(self);
201 		(void) _private_mutex_unlock(&udp->fork_lock);
202 		_postfork_parent_handler();
203 	}
204 
205 	(void) _private_mutex_unlock(&udp->atfork_lock);
206 	self->ul_fork = 0;
207 	sigon(self);
208 
209 	return (pid);
210 }
211 
212 /*
213  * fork() is fork1() for both Posix threads and Solaris threads.
214  * The forkall() interface exists for applications that require
215  * the semantics of replicating all threads.
216  */
217 #pragma weak fork1 = _fork
218 #pragma weak _fork1 = _fork
219 #pragma weak fork = _fork
220 pid_t
221 _fork(void)
222 {
223 	return (_private_forkx(0));
224 }
225 
226 /*
227  * Much of the logic here is the same as in forkx().
228  * See the comments in forkx(), above.
229  */
230 #pragma weak forkallx = _private_forkallx
231 #pragma weak _forkallx = _private_forkallx
232 pid_t
233 _private_forkallx(int flags)
234 {
235 	ulwp_t *self = curthread;
236 	uberdata_t *udp = self->ul_uberdata;
237 	pid_t pid;
238 
239 	if (self->ul_vfork) {
240 		if (udp->uberflags.uf_mt) {
241 			errno = ENOTSUP;
242 			return (-1);
243 		}
244 		pid = __forkallx(flags);
245 		if (pid == 0) {		/* child */
246 			udp->pid = _private_getpid();
247 			self->ul_vfork = 0;
248 		}
249 		return (pid);
250 	}
251 
252 	sigoff(self);
253 	if (self->ul_fork) {
254 		sigon(self);
255 		errno = EDEADLK;
256 		return (-1);
257 	}
258 	self->ul_fork = 1;
259 	(void) _private_mutex_lock(&udp->atfork_lock);
260 	(void) _private_mutex_lock(&udp->fork_lock);
261 	block_all_signals(self);
262 	suspend_fork();
263 
264 	pid = __forkallx(flags);
265 
266 	if (pid == 0) {
267 		self->ul_schedctl_called = NULL;
268 		self->ul_schedctl = NULL;
269 		self->ul_cursig = 0;
270 		self->ul_siginfo.si_signo = 0;
271 		udp->pid = _private_getpid();
272 		unregister_locks();
273 		continue_fork(1);
274 	} else {
275 		continue_fork(0);
276 	}
277 	restore_signals(self);
278 	(void) _private_mutex_unlock(&udp->fork_lock);
279 	(void) _private_mutex_unlock(&udp->atfork_lock);
280 	self->ul_fork = 0;
281 	sigon(self);
282 
283 	return (pid);
284 }
285 
286 #pragma weak forkall = _forkall
287 pid_t
288 _forkall(void)
289 {
290 	return (_private_forkallx(0));
291 }
292 
293 /*
294  * For the implementation of cancellation at cancellation points.
295  */
296 #define	PROLOGUE							\
297 {									\
298 	ulwp_t *self = curthread;					\
299 	int nocancel =							\
300 	    (self->ul_vfork | self->ul_nocancel | self->ul_libc_locks |	\
301 	    self->ul_critical | self->ul_sigdefer);			\
302 	int abort = 0;							\
303 	if (nocancel == 0) {						\
304 		self->ul_save_async = self->ul_cancel_async;		\
305 		if (!self->ul_cancel_disabled) {			\
306 			self->ul_cancel_async = 1;			\
307 			if (self->ul_cancel_pending)			\
308 				_pthread_exit(PTHREAD_CANCELED);	\
309 		}							\
310 		self->ul_sp = stkptr();					\
311 	} else if (self->ul_cancel_pending &&				\
312 	    !self->ul_cancel_disabled) {				\
313 		set_cancel_eintr_flag(self);				\
314 		abort = 1;						\
315 	}
316 
317 #define	EPILOGUE							\
318 	if (nocancel == 0) {						\
319 		self->ul_sp = 0;					\
320 		self->ul_cancel_async = self->ul_save_async;		\
321 	}								\
322 }
323 
324 /*
325  * Perform the body of the action required by most of the cancelable
326  * function calls.  The return(function_call) part is to allow the
327  * compiler to make the call be executed with tail recursion, which
328  * saves a register window on sparc and slightly (not much) improves
329  * the code for x86/x64 compilations.
330  */
331 #define	PERFORM(function_call)						\
332 	PROLOGUE							\
333 	if (abort) {							\
334 		*self->ul_errnop = EINTR;				\
335 		return (-1);						\
336 	}								\
337 	if (nocancel)							\
338 		return (function_call);					\
339 	rv = function_call;						\
340 	EPILOGUE							\
341 	return (rv);
342 
343 /*
344  * Specialized prologue for sigsuspend() and pollsys().
345  * These system calls pass a signal mask to the kernel.
346  * The kernel replaces the thread's signal mask with the
347  * temporary mask before the thread goes to sleep.  If
348  * a signal is received, the signal handler will execute
349  * with the temporary mask, as modified by the sigaction
350  * for the particular signal.
351  *
352  * We block all signals until we reach the kernel with the
353  * temporary mask.  This eliminates race conditions with
354  * setting the signal mask while signals are being posted.
355  */
356 #define	PROLOGUE_MASK(sigmask)						\
357 {									\
358 	ulwp_t *self = curthread;					\
359 	int nocancel =							\
360 	    (self->ul_vfork | self->ul_nocancel | self->ul_libc_locks |	\
361 	    self->ul_critical | self->ul_sigdefer);			\
362 	if (!self->ul_vfork) {						\
363 		if (sigmask) {						\
364 			block_all_signals(self);			\
365 			self->ul_tmpmask.__sigbits[0] = sigmask->__sigbits[0]; \
366 			self->ul_tmpmask.__sigbits[1] = sigmask->__sigbits[1]; \
367 			delete_reserved_signals(&self->ul_tmpmask);	\
368 			self->ul_sigsuspend = 1;			\
369 		}							\
370 		if (nocancel == 0) {					\
371 			self->ul_save_async = self->ul_cancel_async;	\
372 			if (!self->ul_cancel_disabled) {		\
373 				self->ul_cancel_async = 1;		\
374 				if (self->ul_cancel_pending) {		\
375 					if (self->ul_sigsuspend) {	\
376 						self->ul_sigsuspend = 0;\
377 						restore_signals(self);	\
378 					}				\
379 					_pthread_exit(PTHREAD_CANCELED);\
380 				}					\
381 			}						\
382 			self->ul_sp = stkptr();				\
383 		}							\
384 	}
385 
386 /*
387  * If a signal is taken, we return from the system call wrapper with
388  * our original signal mask restored (see code in call_user_handler()).
389  * If not (self->ul_sigsuspend is still non-zero), we must restore our
390  * original signal mask ourself.
391  */
392 #define	EPILOGUE_MASK							\
393 	if (nocancel == 0) {						\
394 		self->ul_sp = 0;					\
395 		self->ul_cancel_async = self->ul_save_async;		\
396 	}								\
397 	if (self->ul_sigsuspend) {					\
398 		self->ul_sigsuspend = 0;				\
399 		restore_signals(self);					\
400 	}								\
401 }
402 
403 /*
404  * Cancellation prologue and epilogue functions,
405  * for cancellation points too complex to include here.
406  */
407 void
408 _cancel_prologue(void)
409 {
410 	ulwp_t *self = curthread;
411 
412 	self->ul_cancel_prologue =
413 	    (self->ul_vfork | self->ul_nocancel | self->ul_libc_locks |
414 	    self->ul_critical | self->ul_sigdefer) != 0;
415 	if (self->ul_cancel_prologue == 0) {
416 		self->ul_save_async = self->ul_cancel_async;
417 		if (!self->ul_cancel_disabled) {
418 			self->ul_cancel_async = 1;
419 			if (self->ul_cancel_pending)
420 				_pthread_exit(PTHREAD_CANCELED);
421 		}
422 		self->ul_sp = stkptr();
423 	} else if (self->ul_cancel_pending &&
424 	    !self->ul_cancel_disabled) {
425 		set_cancel_eintr_flag(self);
426 	}
427 }
428 
429 void
430 _cancel_epilogue(void)
431 {
432 	ulwp_t *self = curthread;
433 
434 	if (self->ul_cancel_prologue == 0) {
435 		self->ul_sp = 0;
436 		self->ul_cancel_async = self->ul_save_async;
437 	}
438 }
439 
440 /*
441  * Called from _thrp_join() (thr_join() is a cancellation point)
442  */
443 int
444 lwp_wait(thread_t tid, thread_t *found)
445 {
446 	int error;
447 
448 	PROLOGUE
449 	if (abort)
450 		return (EINTR);
451 	while ((error = __lwp_wait(tid, found)) == EINTR && !cancel_active())
452 		continue;
453 	EPILOGUE
454 	return (error);
455 }
456 
457 #pragma weak read = _read
458 ssize_t
459 _read(int fd, void *buf, size_t size)
460 {
461 	extern ssize_t __read(int, void *, size_t);
462 	ssize_t rv;
463 
464 	PERFORM(__read(fd, buf, size))
465 }
466 
467 #pragma weak write = _write
468 ssize_t
469 _write(int fd, const void *buf, size_t size)
470 {
471 	extern ssize_t __write(int, const void *, size_t);
472 	ssize_t rv;
473 
474 	PERFORM(__write(fd, buf, size))
475 }
476 
477 #pragma weak getmsg = _getmsg
478 int
479 _getmsg(int fd, struct strbuf *ctlptr, struct strbuf *dataptr,
480 	int *flagsp)
481 {
482 	extern int __getmsg(int, struct strbuf *, struct strbuf *, int *);
483 	int rv;
484 
485 	PERFORM(__getmsg(fd, ctlptr, dataptr, flagsp))
486 }
487 
488 #pragma weak getpmsg = _getpmsg
489 int
490 _getpmsg(int fd, struct strbuf *ctlptr, struct strbuf *dataptr,
491 	int *bandp, int *flagsp)
492 {
493 	extern int __getpmsg(int, struct strbuf *, struct strbuf *,
494 	    int *, int *);
495 	int rv;
496 
497 	PERFORM(__getpmsg(fd, ctlptr, dataptr, bandp, flagsp))
498 }
499 
500 #pragma weak putmsg = _putmsg
501 int
502 _putmsg(int fd, const struct strbuf *ctlptr,
503 	const struct strbuf *dataptr, int flags)
504 {
505 	extern int __putmsg(int, const struct strbuf *,
506 	    const struct strbuf *, int);
507 	int rv;
508 
509 	PERFORM(__putmsg(fd, ctlptr, dataptr, flags))
510 }
511 
512 int
513 __xpg4_putmsg(int fd, const struct strbuf *ctlptr,
514 	const struct strbuf *dataptr, int flags)
515 {
516 	extern int __putmsg(int, const struct strbuf *,
517 	    const struct strbuf *, int);
518 	int rv;
519 
520 	PERFORM(__putmsg(fd, ctlptr, dataptr, flags|MSG_XPG4))
521 }
522 
523 #pragma weak putpmsg = _putpmsg
524 int
525 _putpmsg(int fd, const struct strbuf *ctlptr,
526 	const struct strbuf *dataptr, int band, int flags)
527 {
528 	extern int __putpmsg(int, const struct strbuf *,
529 	    const struct strbuf *, int, int);
530 	int rv;
531 
532 	PERFORM(__putpmsg(fd, ctlptr, dataptr, band, flags))
533 }
534 
535 int
536 __xpg4_putpmsg(int fd, const struct strbuf *ctlptr,
537 	const struct strbuf *dataptr, int band, int flags)
538 {
539 	extern int __putpmsg(int, const struct strbuf *,
540 	    const struct strbuf *, int, int);
541 	int rv;
542 
543 	PERFORM(__putpmsg(fd, ctlptr, dataptr, band, flags|MSG_XPG4))
544 }
545 
546 #pragma weak nanosleep = _nanosleep
547 int
548 _nanosleep(const timespec_t *rqtp, timespec_t *rmtp)
549 {
550 	int error;
551 
552 	PROLOGUE
553 	error = abort? EINTR : __nanosleep(rqtp, rmtp);
554 	EPILOGUE
555 	if (error) {
556 		errno = error;
557 		return (-1);
558 	}
559 	return (0);
560 }
561 
562 #pragma weak clock_nanosleep = _clock_nanosleep
563 int
564 _clock_nanosleep(clockid_t clock_id, int flags,
565 	const timespec_t *rqtp, timespec_t *rmtp)
566 {
567 	timespec_t reltime;
568 	hrtime_t start;
569 	hrtime_t rqlapse;
570 	hrtime_t lapse;
571 	int error;
572 
573 	switch (clock_id) {
574 	case CLOCK_VIRTUAL:
575 	case CLOCK_PROCESS_CPUTIME_ID:
576 	case CLOCK_THREAD_CPUTIME_ID:
577 		return (ENOTSUP);
578 	case CLOCK_REALTIME:
579 	case CLOCK_HIGHRES:
580 		break;
581 	default:
582 		return (EINVAL);
583 	}
584 	if (flags & TIMER_ABSTIME) {
585 		abstime_to_reltime(clock_id, rqtp, &reltime);
586 		rmtp = NULL;
587 	} else {
588 		reltime = *rqtp;
589 		if (clock_id == CLOCK_HIGHRES)
590 			start = gethrtime();
591 	}
592 restart:
593 	PROLOGUE
594 	error = abort? EINTR : __nanosleep(&reltime, rmtp);
595 	EPILOGUE
596 	if (error == 0 && clock_id == CLOCK_HIGHRES) {
597 		/*
598 		 * Don't return yet if we didn't really get a timeout.
599 		 * This can happen if we return because someone resets
600 		 * the system clock.
601 		 */
602 		if (flags & TIMER_ABSTIME) {
603 			if ((hrtime_t)(uint32_t)rqtp->tv_sec * NANOSEC +
604 			    rqtp->tv_nsec > gethrtime()) {
605 				abstime_to_reltime(clock_id, rqtp, &reltime);
606 				goto restart;
607 			}
608 		} else {
609 			rqlapse = (hrtime_t)(uint32_t)rqtp->tv_sec * NANOSEC +
610 			    rqtp->tv_nsec;
611 			lapse = gethrtime() - start;
612 			if (rqlapse > lapse) {
613 				hrt2ts(rqlapse - lapse, &reltime);
614 				goto restart;
615 			}
616 		}
617 	}
618 	if (error == 0 && clock_id == CLOCK_REALTIME &&
619 	    (flags & TIMER_ABSTIME)) {
620 		/*
621 		 * Don't return yet just because someone reset the
622 		 * system clock.  Recompute the new relative time
623 		 * and reissue the nanosleep() call if necessary.
624 		 *
625 		 * Resetting the system clock causes all sorts of
626 		 * problems and the SUSV3 standards body should
627 		 * have made the behavior of clock_nanosleep() be
628 		 * implementation-defined in such a case rather than
629 		 * being specific about honoring the new system time.
630 		 * Standards bodies are filled with fools and idiots.
631 		 */
632 		abstime_to_reltime(clock_id, rqtp, &reltime);
633 		if (reltime.tv_sec != 0 || reltime.tv_nsec != 0)
634 			goto restart;
635 	}
636 	return (error);
637 }
638 
639 #pragma weak sleep = _sleep
640 unsigned int
641 _sleep(unsigned int sec)
642 {
643 	unsigned int rem = 0;
644 	timespec_t ts;
645 	timespec_t tsr;
646 
647 	ts.tv_sec = (time_t)sec;
648 	ts.tv_nsec = 0;
649 	if (_nanosleep(&ts, &tsr) == -1 && errno == EINTR) {
650 		rem = (unsigned int)tsr.tv_sec;
651 		if (tsr.tv_nsec >= NANOSEC / 2)
652 			rem++;
653 	}
654 	return (rem);
655 }
656 
657 #pragma weak usleep = _usleep
658 int
659 _usleep(useconds_t usec)
660 {
661 	timespec_t ts;
662 
663 	ts.tv_sec = usec / MICROSEC;
664 	ts.tv_nsec = (long)(usec % MICROSEC) * 1000;
665 	(void) _nanosleep(&ts, NULL);
666 	return (0);
667 }
668 
669 #pragma weak close = _close
670 int
671 _close(int fildes)
672 {
673 	extern void _aio_close(int);
674 	extern int __close(int);
675 	int rv;
676 
677 	_aio_close(fildes);
678 	PERFORM(__close(fildes))
679 }
680 
681 #pragma weak creat = _creat
682 int
683 _creat(const char *path, mode_t mode)
684 {
685 	extern int __creat(const char *, mode_t);
686 	int rv;
687 
688 	PERFORM(__creat(path, mode))
689 }
690 
691 #if !defined(_LP64)
692 #pragma weak creat64 = _creat64
693 int
694 _creat64(const char *path, mode_t mode)
695 {
696 	extern int __creat64(const char *, mode_t);
697 	int rv;
698 
699 	PERFORM(__creat64(path, mode))
700 }
701 #endif	/* !_LP64 */
702 
703 #pragma weak door_call = _door_call
704 int
705 _door_call(int d, door_arg_t *params)
706 {
707 	extern int __door_call(int, door_arg_t *);
708 	int rv;
709 
710 	PERFORM(__door_call(d, params))
711 }
712 
713 #pragma weak fcntl = _fcntl
714 int
715 _fcntl(int fildes, int cmd, ...)
716 {
717 	extern int __fcntl(int, int, ...);
718 	intptr_t arg;
719 	int rv;
720 	va_list ap;
721 
722 	va_start(ap, cmd);
723 	arg = va_arg(ap, intptr_t);
724 	va_end(ap);
725 	if (cmd != F_SETLKW)
726 		return (__fcntl(fildes, cmd, arg));
727 	PERFORM(__fcntl(fildes, cmd, arg))
728 }
729 
730 #pragma weak fdatasync = _fdatasync
731 int
732 _fdatasync(int fildes)
733 {
734 	extern int __fdsync(int, int);
735 	int rv;
736 
737 	PERFORM(__fdsync(fildes, FDSYNC))
738 }
739 
740 #pragma weak fsync = _fsync
741 int
742 _fsync(int fildes)
743 {
744 	extern int __fdsync(int, int);
745 	int rv;
746 
747 	PERFORM(__fdsync(fildes, FSYNC))
748 }
749 
750 #pragma weak lockf = _lockf
751 int
752 _lockf(int fildes, int function, off_t size)
753 {
754 	extern int __lockf(int, int, off_t);
755 	int rv;
756 
757 	PERFORM(__lockf(fildes, function, size))
758 }
759 
760 #if !defined(_LP64)
761 #pragma weak lockf64 = _lockf64
762 int
763 _lockf64(int fildes, int function, off64_t size)
764 {
765 	extern int __lockf64(int, int, off64_t);
766 	int rv;
767 
768 	PERFORM(__lockf64(fildes, function, size))
769 }
770 #endif	/* !_LP64 */
771 
772 #pragma weak msgrcv = _msgrcv
773 ssize_t
774 _msgrcv(int msqid, void *msgp, size_t msgsz, long msgtyp, int msgflg)
775 {
776 	extern ssize_t __msgrcv(int, void *, size_t, long, int);
777 	ssize_t rv;
778 
779 	PERFORM(__msgrcv(msqid, msgp, msgsz, msgtyp, msgflg))
780 }
781 
782 #pragma weak msgsnd = _msgsnd
783 int
784 _msgsnd(int msqid, const void *msgp, size_t msgsz, int msgflg)
785 {
786 	extern int __msgsnd(int, const void *, size_t, int);
787 	int rv;
788 
789 	PERFORM(__msgsnd(msqid, msgp, msgsz, msgflg))
790 }
791 
792 #pragma weak msync = _msync
793 int
794 _msync(caddr_t addr, size_t len, int flags)
795 {
796 	extern int __msync(caddr_t, size_t, int);
797 	int rv;
798 
799 	PERFORM(__msync(addr, len, flags))
800 }
801 
802 #pragma weak open = _open
803 int
804 _open(const char *path, int oflag, ...)
805 {
806 	extern int __open(const char *, int, ...);
807 	mode_t mode;
808 	int rv;
809 	va_list ap;
810 
811 	va_start(ap, oflag);
812 	mode = va_arg(ap, mode_t);
813 	va_end(ap);
814 	PERFORM(__open(path, oflag, mode))
815 }
816 
817 #pragma weak openat = _openat
818 int
819 _openat(int fd, const char *path, int oflag, ...)
820 {
821 	extern int __openat(int, const char *, int, ...);
822 	mode_t mode;
823 	int rv;
824 	va_list ap;
825 
826 	va_start(ap, oflag);
827 	mode = va_arg(ap, mode_t);
828 	va_end(ap);
829 	PERFORM(__openat(fd, path, oflag, mode))
830 }
831 
832 #if !defined(_LP64)
833 #pragma weak open64 = _open64
834 int
835 _open64(const char *path, int oflag, ...)
836 {
837 	extern int __open64(const char *, int, ...);
838 	mode_t mode;
839 	int rv;
840 	va_list ap;
841 
842 	va_start(ap, oflag);
843 	mode = va_arg(ap, mode_t);
844 	va_end(ap);
845 	PERFORM(__open64(path, oflag, mode))
846 }
847 
848 #pragma weak openat64 = _openat64
849 int
850 _openat64(int fd, const char *path, int oflag, ...)
851 {
852 	extern int __openat64(int, const char *, int, ...);
853 	mode_t mode;
854 	int rv;
855 	va_list ap;
856 
857 	va_start(ap, oflag);
858 	mode = va_arg(ap, mode_t);
859 	va_end(ap);
860 	PERFORM(__openat64(fd, path, oflag, mode))
861 }
862 #endif	/* !_LP64 */
863 
864 #pragma weak pause = _pause
865 int
866 _pause(void)
867 {
868 	extern int __pause(void);
869 	int rv;
870 
871 	PERFORM(__pause())
872 }
873 
874 #pragma weak pread = _pread
875 ssize_t
876 _pread(int fildes, void *buf, size_t nbyte, off_t offset)
877 {
878 	extern ssize_t __pread(int, void *, size_t, off_t);
879 	ssize_t rv;
880 
881 	PERFORM(__pread(fildes, buf, nbyte, offset))
882 }
883 
884 #if !defined(_LP64)
885 #pragma weak pread64 = _pread64
886 ssize_t
887 _pread64(int fildes, void *buf, size_t nbyte, off64_t offset)
888 {
889 	extern ssize_t __pread64(int, void *, size_t, off64_t);
890 	ssize_t rv;
891 
892 	PERFORM(__pread64(fildes, buf, nbyte, offset))
893 }
894 #endif	/* !_LP64 */
895 
896 #pragma weak pwrite = _pwrite
897 ssize_t
898 _pwrite(int fildes, const void *buf, size_t nbyte, off_t offset)
899 {
900 	extern ssize_t __pwrite(int, const void *, size_t, off_t);
901 	ssize_t rv;
902 
903 	PERFORM(__pwrite(fildes, buf, nbyte, offset))
904 }
905 
906 #if !defined(_LP64)
907 #pragma weak pwrite64 = _pwrite64
908 ssize_t
909 _pwrite64(int fildes, const void *buf, size_t nbyte, off64_t offset)
910 {
911 	extern ssize_t __pwrite64(int, const void *, size_t, off64_t);
912 	ssize_t rv;
913 
914 	PERFORM(__pwrite64(fildes, buf, nbyte, offset))
915 }
916 #endif	/* !_LP64 */
917 
918 #pragma weak readv = _readv
919 ssize_t
920 _readv(int fildes, const struct iovec *iov, int iovcnt)
921 {
922 	extern ssize_t __readv(int, const struct iovec *, int);
923 	ssize_t rv;
924 
925 	PERFORM(__readv(fildes, iov, iovcnt))
926 }
927 
928 #pragma weak sigpause = _sigpause
929 int
930 _sigpause(int sig)
931 {
932 	extern int __sigpause(int);
933 	int rv;
934 
935 	PERFORM(__sigpause(sig))
936 }
937 
938 #pragma weak sigsuspend = _sigsuspend
939 int
940 _sigsuspend(const sigset_t *set)
941 {
942 	extern int __sigsuspend(const sigset_t *);
943 	int rv;
944 
945 	PROLOGUE_MASK(set)
946 	rv = __sigsuspend(set);
947 	EPILOGUE_MASK
948 	return (rv);
949 }
950 
951 int
952 _pollsys(struct pollfd *fds, nfds_t nfd, const timespec_t *timeout,
953 	const sigset_t *sigmask)
954 {
955 	extern int __pollsys(struct pollfd *, nfds_t, const timespec_t *,
956 	    const sigset_t *);
957 	int rv;
958 
959 	PROLOGUE_MASK(sigmask)
960 	rv = __pollsys(fds, nfd, timeout, sigmask);
961 	EPILOGUE_MASK
962 	return (rv);
963 }
964 
965 #pragma weak sigtimedwait = _sigtimedwait
966 int
967 _sigtimedwait(const sigset_t *set, siginfo_t *infop, const timespec_t *timeout)
968 {
969 	extern int __sigtimedwait(const sigset_t *, siginfo_t *,
970 	    const timespec_t *);
971 	siginfo_t info;
972 	int sig;
973 
974 	PROLOGUE
975 	if (abort) {
976 		*self->ul_errnop = EINTR;
977 		sig = -1;
978 	} else {
979 		sig = __sigtimedwait(set, &info, timeout);
980 		if (sig == SIGCANCEL &&
981 		    (SI_FROMKERNEL(&info) || info.si_code == SI_LWP)) {
982 			do_sigcancel();
983 			*self->ul_errnop = EINTR;
984 			sig = -1;
985 		}
986 	}
987 	EPILOGUE
988 	if (sig != -1 && infop)
989 		(void) _private_memcpy(infop, &info, sizeof (*infop));
990 	return (sig);
991 }
992 
993 #pragma weak sigwait = _sigwait
994 int
995 _sigwait(sigset_t *set)
996 {
997 	return (_sigtimedwait(set, NULL, NULL));
998 }
999 
1000 #pragma weak sigwaitinfo = _sigwaitinfo
1001 int
1002 _sigwaitinfo(const sigset_t *set, siginfo_t *info)
1003 {
1004 	return (_sigtimedwait(set, info, NULL));
1005 }
1006 
1007 #pragma weak sigqueue = _sigqueue
1008 int
1009 _sigqueue(pid_t pid, int signo, const union sigval value)
1010 {
1011 	extern int __sigqueue(pid_t pid, int signo,
1012 	    /* const union sigval */ void *value, int si_code, int block);
1013 	return (__sigqueue(pid, signo, value.sival_ptr, SI_QUEUE, 0));
1014 }
1015 
1016 int
1017 _so_accept(int sock, struct sockaddr *addr, uint_t *addrlen, int version)
1018 {
1019 	extern int __so_accept(int, struct sockaddr *, uint_t *, int);
1020 	int rv;
1021 
1022 	PERFORM(__so_accept(sock, addr, addrlen, version))
1023 }
1024 
1025 int
1026 _so_connect(int sock, struct sockaddr *addr, uint_t addrlen, int version)
1027 {
1028 	extern int __so_connect(int, struct sockaddr *, uint_t, int);
1029 	int rv;
1030 
1031 	PERFORM(__so_connect(sock, addr, addrlen, version))
1032 }
1033 
1034 int
1035 _so_recv(int sock, void *buf, size_t len, int flags)
1036 {
1037 	extern int __so_recv(int, void *, size_t, int);
1038 	int rv;
1039 
1040 	PERFORM(__so_recv(sock, buf, len, flags))
1041 }
1042 
1043 int
1044 _so_recvfrom(int sock, void *buf, size_t len, int flags,
1045     struct sockaddr *addr, int *addrlen)
1046 {
1047 	extern int __so_recvfrom(int, void *, size_t, int,
1048 	    struct sockaddr *, int *);
1049 	int rv;
1050 
1051 	PERFORM(__so_recvfrom(sock, buf, len, flags, addr, addrlen))
1052 }
1053 
1054 int
1055 _so_recvmsg(int sock, struct msghdr *msg, int flags)
1056 {
1057 	extern int __so_recvmsg(int, struct msghdr *, int);
1058 	int rv;
1059 
1060 	PERFORM(__so_recvmsg(sock, msg, flags))
1061 }
1062 
1063 int
1064 _so_send(int sock, const void *buf, size_t len, int flags)
1065 {
1066 	extern int __so_send(int, const void *, size_t, int);
1067 	int rv;
1068 
1069 	PERFORM(__so_send(sock, buf, len, flags))
1070 }
1071 
1072 int
1073 _so_sendmsg(int sock, const struct msghdr *msg, int flags)
1074 {
1075 	extern int __so_sendmsg(int, const struct msghdr *, int);
1076 	int rv;
1077 
1078 	PERFORM(__so_sendmsg(sock, msg, flags))
1079 }
1080 
1081 int
1082 _so_sendto(int sock, const void *buf, size_t len, int flags,
1083     const struct sockaddr *addr, int *addrlen)
1084 {
1085 	extern int __so_sendto(int, const void *, size_t, int,
1086 	    const struct sockaddr *, int *);
1087 	int rv;
1088 
1089 	PERFORM(__so_sendto(sock, buf, len, flags, addr, addrlen))
1090 }
1091 
1092 #pragma weak tcdrain = _tcdrain
1093 int
1094 _tcdrain(int fildes)
1095 {
1096 	extern int __tcdrain(int);
1097 	int rv;
1098 
1099 	PERFORM(__tcdrain(fildes))
1100 }
1101 
1102 #pragma weak waitid = _waitid
1103 int
1104 _waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options)
1105 {
1106 	extern int __waitid(idtype_t, id_t, siginfo_t *, int);
1107 	int rv;
1108 
1109 	if (options & WNOHANG)
1110 		return (__waitid(idtype, id, infop, options));
1111 	PERFORM(__waitid(idtype, id, infop, options))
1112 }
1113 
1114 #pragma weak writev = _writev
1115 ssize_t
1116 _writev(int fildes, const struct iovec *iov, int iovcnt)
1117 {
1118 	extern ssize_t __writev(int, const struct iovec *, int);
1119 	ssize_t rv;
1120 
1121 	PERFORM(__writev(fildes, iov, iovcnt))
1122 }
1123