1 /* 2 * Copyright (c) 2005, David Xu <davidxu@freebsd.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice unmodified, this list of conditions, and the following 10 * disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include "namespace.h" 30 #include <sys/param.h> 31 #include <sys/types.h> 32 #include <sys/signalvar.h> 33 #include <signal.h> 34 #include <errno.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <pthread.h> 38 #include "un-namespace.h" 39 #include "libc_private.h" 40 41 #include "thr_private.h" 42 43 /* #define DEBUG_SIGNAL */ 44 #ifdef DEBUG_SIGNAL 45 #define DBG_MSG stdout_debug 46 #else 47 #define DBG_MSG(x...) 48 #endif 49 50 struct usigaction { 51 struct sigaction sigact; 52 struct urwlock lock; 53 }; 54 55 static struct usigaction _thr_sigact[_SIG_MAXSIG]; 56 57 static void thr_sighandler(int, siginfo_t *, void *); 58 static void handle_signal(struct sigaction *, int, siginfo_t *, ucontext_t *); 59 static void check_deferred_signal(struct pthread *); 60 static void check_suspend(struct pthread *); 61 static void check_cancel(struct pthread *curthread, ucontext_t *ucp); 62 63 int ___pause(void); 64 int _raise(int); 65 int __sigtimedwait(const sigset_t *set, siginfo_t *info, 66 const struct timespec * timeout); 67 int _sigtimedwait(const sigset_t *set, siginfo_t *info, 68 const struct timespec * timeout); 69 int __sigwaitinfo(const sigset_t *set, siginfo_t *info); 70 int _sigwaitinfo(const sigset_t *set, siginfo_t *info); 71 int ___sigwait(const sigset_t *set, int *sig); 72 int _sigwait(const sigset_t *set, int *sig); 73 int __sigsuspend(const sigset_t *sigmask); 74 int _sigaction(int, const struct sigaction *, struct sigaction *); 75 int _setcontext(const ucontext_t *); 76 int _swapcontext(ucontext_t *, const ucontext_t *); 77 78 static const sigset_t _thr_deferset={{ 79 0xffffffff & ~(_SIG_BIT(SIGBUS)|_SIG_BIT(SIGILL)|_SIG_BIT(SIGFPE)| 80 _SIG_BIT(SIGSEGV)|_SIG_BIT(SIGTRAP)|_SIG_BIT(SIGSYS)), 81 0xffffffff, 82 0xffffffff, 83 0xffffffff}}; 84 85 static const sigset_t _thr_maskset={{ 86 0xffffffff, 87 0xffffffff, 88 0xffffffff, 89 0xffffffff}}; 90 91 void 92 _thr_signal_block(struct pthread *curthread) 93 { 94 95 if (curthread->sigblock > 0) { 96 curthread->sigblock++; 97 return; 98 } 99 __sys_sigprocmask(SIG_BLOCK, &_thr_maskset, &curthread->sigmask); 100 curthread->sigblock++; 101 } 102 103 void 104 _thr_signal_unblock(struct pthread *curthread) 105 { 106 if (--curthread->sigblock == 0) 107 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 108 } 109 110 int 111 _thr_send_sig(struct pthread *thread, int sig) 112 { 113 return thr_kill(thread->tid, sig); 114 } 115 116 static inline void 117 remove_thr_signals(sigset_t *set) 118 { 119 if (SIGISMEMBER(*set, SIGCANCEL)) 120 SIGDELSET(*set, SIGCANCEL); 121 } 122 123 static const sigset_t * 124 thr_remove_thr_signals(const sigset_t *set, sigset_t *newset) 125 { 126 *newset = *set; 127 remove_thr_signals(newset); 128 return (newset); 129 } 130 131 static void 132 sigcancel_handler(int sig __unused, 133 siginfo_t *info __unused, ucontext_t *ucp) 134 { 135 struct pthread *curthread = _get_curthread(); 136 int err; 137 138 if (THR_IN_CRITICAL(curthread)) 139 return; 140 err = errno; 141 check_suspend(curthread); 142 check_cancel(curthread, ucp); 143 errno = err; 144 } 145 146 typedef void (*ohandler)(int sig, int code, 147 struct sigcontext *scp, char *addr, __sighandler_t *catcher); 148 149 /* 150 * The signal handler wrapper is entered with all signal masked. 151 */ 152 static void 153 thr_sighandler(int sig, siginfo_t *info, void *_ucp) 154 { 155 struct pthread *curthread = _get_curthread(); 156 ucontext_t *ucp = _ucp; 157 struct sigaction act; 158 int err; 159 160 err = errno; 161 _thr_rwl_rdlock(&_thr_sigact[sig-1].lock); 162 act = _thr_sigact[sig-1].sigact; 163 _thr_rwl_unlock(&_thr_sigact[sig-1].lock); 164 errno = err; 165 166 /* 167 * if a thread is in critical region, for example it holds low level locks, 168 * try to defer the signal processing, however if the signal is synchronous 169 * signal, it means a bad thing has happened, this is a programming error, 170 * resuming fault point can not help anything (normally causes deadloop), 171 * so here we let user code handle it immediately. 172 */ 173 if (THR_IN_CRITICAL(curthread) && SIGISMEMBER(_thr_deferset, sig)) { 174 memcpy(&curthread->deferred_sigact, &act, sizeof(struct sigaction)); 175 memcpy(&curthread->deferred_siginfo, info, sizeof(siginfo_t)); 176 curthread->deferred_sigmask = ucp->uc_sigmask; 177 /* mask all signals, we will restore it later. */ 178 ucp->uc_sigmask = _thr_deferset; 179 return; 180 } 181 182 handle_signal(&act, sig, info, ucp); 183 } 184 185 static void 186 handle_signal(struct sigaction *actp, int sig, siginfo_t *info, ucontext_t *ucp) 187 { 188 struct pthread *curthread = _get_curthread(); 189 ucontext_t uc2; 190 __siginfohandler_t *sigfunc; 191 int cancel_point; 192 int cancel_async; 193 int cancel_enable; 194 int in_sigsuspend; 195 int err; 196 197 /* add previous level mask */ 198 SIGSETOR(actp->sa_mask, ucp->uc_sigmask); 199 200 /* add this signal's mask */ 201 if (!(actp->sa_flags & SA_NODEFER)) 202 SIGADDSET(actp->sa_mask, sig); 203 204 in_sigsuspend = curthread->in_sigsuspend; 205 curthread->in_sigsuspend = 0; 206 207 /* 208 * If thread is in deferred cancellation mode, disable cancellation 209 * in signal handler. 210 * If user signal handler calls a cancellation point function, e.g, 211 * it calls write() to write data to file, because write() is a 212 * cancellation point, the thread is immediately cancelled if 213 * cancellation is pending, to avoid this problem while thread is in 214 * deferring mode, cancellation is temporarily disabled. 215 */ 216 cancel_point = curthread->cancel_point; 217 cancel_async = curthread->cancel_async; 218 cancel_enable = curthread->cancel_enable; 219 curthread->cancel_point = 0; 220 if (!cancel_async) 221 curthread->cancel_enable = 0; 222 223 /* restore correct mask before calling user handler */ 224 __sys_sigprocmask(SIG_SETMASK, &actp->sa_mask, NULL); 225 226 sigfunc = actp->sa_sigaction; 227 228 /* 229 * We have already reset cancellation point flags, so if user's code 230 * longjmp()s out of its signal handler, wish its jmpbuf was set 231 * outside of a cancellation point, in most cases, this would be 232 * true. However, there is no way to save cancel_enable in jmpbuf, 233 * so after setjmps() returns once more, the user code may need to 234 * re-set cancel_enable flag by calling pthread_setcancelstate(). 235 */ 236 if ((actp->sa_flags & SA_SIGINFO) != 0) 237 (*(sigfunc))(sig, info, ucp); 238 else { 239 ((ohandler)(*sigfunc))( 240 sig, info->si_code, (struct sigcontext *)ucp, 241 info->si_addr, (__sighandler_t *)sigfunc); 242 } 243 err = errno; 244 245 curthread->in_sigsuspend = in_sigsuspend; 246 curthread->cancel_point = cancel_point; 247 curthread->cancel_enable = cancel_enable; 248 249 memcpy(&uc2, ucp, sizeof(uc2)); 250 SIGDELSET(uc2.uc_sigmask, SIGCANCEL); 251 252 /* reschedule cancellation */ 253 check_cancel(curthread, &uc2); 254 errno = err; 255 __sys_sigreturn(&uc2); 256 } 257 258 void 259 _thr_ast(struct pthread *curthread) 260 { 261 262 if (!THR_IN_CRITICAL(curthread)) { 263 check_deferred_signal(curthread); 264 check_suspend(curthread); 265 check_cancel(curthread, NULL); 266 } 267 } 268 269 /* reschedule cancellation */ 270 static void 271 check_cancel(struct pthread *curthread, ucontext_t *ucp) 272 { 273 274 if (__predict_true(!curthread->cancel_pending || 275 !curthread->cancel_enable || curthread->no_cancel)) 276 return; 277 278 /* 279 * Otherwise, we are in defer mode, and we are at 280 * cancel point, tell kernel to not block the current 281 * thread on next cancelable system call. 282 * 283 * There are three cases we should call thr_wake() to 284 * turn on TDP_WAKEUP or send SIGCANCEL in kernel: 285 * 1) we are going to call a cancelable system call, 286 * non-zero cancel_point means we are already in 287 * cancelable state, next system call is cancelable. 288 * 2) because _thr_ast() may be called by 289 * THR_CRITICAL_LEAVE() which is used by rtld rwlock 290 * and any libthr internal locks, when rtld rwlock 291 * is used, it is mostly caused my an unresolved PLT. 292 * those routines may clear the TDP_WAKEUP flag by 293 * invoking some system calls, in those cases, we 294 * also should reenable the flag. 295 * 3) thread is in sigsuspend(), and the syscall insists 296 * on getting a signal before it agrees to return. 297 */ 298 if (curthread->cancel_point) { 299 if (curthread->in_sigsuspend && ucp) { 300 SIGADDSET(ucp->uc_sigmask, SIGCANCEL); 301 curthread->unblock_sigcancel = 1; 302 _thr_send_sig(curthread, SIGCANCEL); 303 } else 304 thr_wake(curthread->tid); 305 } else if (curthread->cancel_async) { 306 /* 307 * asynchronous cancellation mode, act upon 308 * immediately. 309 */ 310 _pthread_exit_mask(PTHREAD_CANCELED, 311 ucp? &ucp->uc_sigmask : NULL); 312 } 313 } 314 315 static void 316 check_deferred_signal(struct pthread *curthread) 317 { 318 ucontext_t *uc; 319 struct sigaction act; 320 siginfo_t info; 321 322 if (__predict_true(curthread->deferred_siginfo.si_signo == 0)) 323 return; 324 325 #if defined(__amd64__) || defined(__i386__) 326 int uc_len; 327 uc_len = __getcontextx_size(); 328 uc = alloca(uc_len); 329 getcontext(uc); 330 if (curthread->deferred_siginfo.si_signo == 0) 331 return; 332 __fillcontextx2((char *)uc); 333 #else 334 ucontext_t ucv; 335 uc = &ucv; 336 getcontext(uc); 337 #endif 338 if (curthread->deferred_siginfo.si_signo != 0) { 339 act = curthread->deferred_sigact; 340 uc->uc_sigmask = curthread->deferred_sigmask; 341 memcpy(&info, &curthread->deferred_siginfo, sizeof(siginfo_t)); 342 /* remove signal */ 343 curthread->deferred_siginfo.si_signo = 0; 344 handle_signal(&act, info.si_signo, &info, uc); 345 } 346 } 347 348 static void 349 check_suspend(struct pthread *curthread) 350 { 351 uint32_t cycle; 352 353 if (__predict_true((curthread->flags & 354 (THR_FLAGS_NEED_SUSPEND | THR_FLAGS_SUSPENDED)) 355 != THR_FLAGS_NEED_SUSPEND)) 356 return; 357 if (curthread == _single_thread) 358 return; 359 if (curthread->force_exit) 360 return; 361 362 /* 363 * Blocks SIGCANCEL which other threads must send. 364 */ 365 _thr_signal_block(curthread); 366 367 /* 368 * Increase critical_count, here we don't use THR_LOCK/UNLOCK 369 * because we are leaf code, we don't want to recursively call 370 * ourself. 371 */ 372 curthread->critical_count++; 373 THR_UMUTEX_LOCK(curthread, &(curthread)->lock); 374 while ((curthread->flags & (THR_FLAGS_NEED_SUSPEND | 375 THR_FLAGS_SUSPENDED)) == THR_FLAGS_NEED_SUSPEND) { 376 curthread->cycle++; 377 cycle = curthread->cycle; 378 379 /* Wake the thread suspending us. */ 380 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0); 381 382 /* 383 * if we are from pthread_exit, we don't want to 384 * suspend, just go and die. 385 */ 386 if (curthread->state == PS_DEAD) 387 break; 388 curthread->flags |= THR_FLAGS_SUSPENDED; 389 THR_UMUTEX_UNLOCK(curthread, &(curthread)->lock); 390 _thr_umtx_wait_uint(&curthread->cycle, cycle, NULL, 0); 391 THR_UMUTEX_LOCK(curthread, &(curthread)->lock); 392 curthread->flags &= ~THR_FLAGS_SUSPENDED; 393 } 394 THR_UMUTEX_UNLOCK(curthread, &(curthread)->lock); 395 curthread->critical_count--; 396 397 _thr_signal_unblock(curthread); 398 } 399 400 void 401 _thr_signal_init(void) 402 { 403 struct sigaction act; 404 405 /* Install SIGCANCEL handler. */ 406 SIGFILLSET(act.sa_mask); 407 act.sa_flags = SA_SIGINFO; 408 act.sa_sigaction = (__siginfohandler_t *)&sigcancel_handler; 409 __sys_sigaction(SIGCANCEL, &act, NULL); 410 411 /* Unblock SIGCANCEL */ 412 SIGEMPTYSET(act.sa_mask); 413 SIGADDSET(act.sa_mask, SIGCANCEL); 414 __sys_sigprocmask(SIG_UNBLOCK, &act.sa_mask, NULL); 415 } 416 417 void 418 _thr_sigact_unload(struct dl_phdr_info *phdr_info) 419 { 420 #if 0 421 struct pthread *curthread = _get_curthread(); 422 struct urwlock *rwlp; 423 struct sigaction *actp; 424 struct sigaction kact; 425 void (*handler)(int); 426 int sig; 427 428 _thr_signal_block(curthread); 429 for (sig = 1; sig <= _SIG_MAXSIG; sig++) { 430 actp = &_thr_sigact[sig-1].sigact; 431 retry: 432 handler = actp->sa_handler; 433 if (handler != SIG_DFL && handler != SIG_IGN && 434 __elf_phdr_match_addr(phdr_info, handler)) { 435 rwlp = &_thr_sigact[sig-1].lock; 436 _thr_rwl_wrlock(rwlp); 437 if (handler != actp->sa_handler) { 438 _thr_rwl_unlock(rwlp); 439 goto retry; 440 } 441 actp->sa_handler = SIG_DFL; 442 actp->sa_flags = SA_SIGINFO; 443 SIGEMPTYSET(actp->sa_mask); 444 if (__sys_sigaction(sig, NULL, &kact) == 0 && 445 kact.sa_handler != SIG_DFL && 446 kact.sa_handler != SIG_IGN) 447 __sys_sigaction(sig, actp, NULL); 448 _thr_rwl_unlock(rwlp); 449 } 450 } 451 _thr_signal_unblock(curthread); 452 #endif 453 } 454 455 void 456 _thr_signal_prefork(void) 457 { 458 int i; 459 460 for (i = 1; i <= _SIG_MAXSIG; ++i) 461 _thr_rwl_rdlock(&_thr_sigact[i-1].lock); 462 } 463 464 void 465 _thr_signal_postfork(void) 466 { 467 int i; 468 469 for (i = 1; i <= _SIG_MAXSIG; ++i) 470 _thr_rwl_unlock(&_thr_sigact[i-1].lock); 471 } 472 473 void 474 _thr_signal_postfork_child(void) 475 { 476 int i; 477 478 for (i = 1; i <= _SIG_MAXSIG; ++i) 479 bzero(&_thr_sigact[i-1].lock, sizeof(struct urwlock)); 480 } 481 482 void 483 _thr_signal_deinit(void) 484 { 485 } 486 487 __weak_reference(___pause, pause); 488 489 int 490 ___pause(void) 491 { 492 sigset_t oset; 493 494 if (_sigprocmask(SIG_BLOCK, NULL, &oset) == -1) 495 return (-1); 496 return (__sigsuspend(&oset)); 497 } 498 499 __weak_reference(_raise, raise); 500 501 int 502 _raise(int sig) 503 { 504 return _thr_send_sig(_get_curthread(), sig); 505 } 506 507 __weak_reference(_sigaction, sigaction); 508 509 int 510 _sigaction(int sig, const struct sigaction * act, struct sigaction * oact) 511 { 512 struct sigaction newact, oldact, oldact2; 513 sigset_t oldset; 514 int ret = 0, err = 0; 515 516 if (!_SIG_VALID(sig) || sig == SIGCANCEL) { 517 errno = EINVAL; 518 return (-1); 519 } 520 521 if (act) 522 newact = *act; 523 524 __sys_sigprocmask(SIG_SETMASK, &_thr_maskset, &oldset); 525 _thr_rwl_wrlock(&_thr_sigact[sig-1].lock); 526 527 if (act != NULL) { 528 oldact2 = _thr_sigact[sig-1].sigact; 529 530 /* 531 * if a new sig handler is SIG_DFL or SIG_IGN, 532 * don't remove old handler from _thr_sigact[], 533 * so deferred signals still can use the handlers, 534 * multiple threads invoking sigaction itself is 535 * a race condition, so it is not a problem. 536 */ 537 if (newact.sa_handler != SIG_DFL && 538 newact.sa_handler != SIG_IGN) { 539 _thr_sigact[sig-1].sigact = newact; 540 remove_thr_signals( 541 &_thr_sigact[sig-1].sigact.sa_mask); 542 newact.sa_flags &= ~SA_NODEFER; 543 newact.sa_flags |= SA_SIGINFO; 544 newact.sa_sigaction = thr_sighandler; 545 newact.sa_mask = _thr_maskset; /* mask all signals */ 546 } 547 if ((ret = __sys_sigaction(sig, &newact, &oldact))) { 548 err = errno; 549 _thr_sigact[sig-1].sigact = oldact2; 550 } 551 } else if (oact != NULL) { 552 ret = __sys_sigaction(sig, NULL, &oldact); 553 err = errno; 554 } 555 556 if (oldact.sa_handler != SIG_DFL && 557 oldact.sa_handler != SIG_IGN) { 558 if (act != NULL) 559 oldact = oldact2; 560 else if (oact != NULL) 561 oldact = _thr_sigact[sig-1].sigact; 562 } 563 564 _thr_rwl_unlock(&_thr_sigact[sig-1].lock); 565 __sys_sigprocmask(SIG_SETMASK, &oldset, NULL); 566 567 if (ret == 0) { 568 if (oact != NULL) 569 *oact = oldact; 570 } else { 571 errno = err; 572 } 573 return (ret); 574 } 575 576 __weak_reference(_sigprocmask, sigprocmask); 577 578 int 579 _sigprocmask(int how, const sigset_t *set, sigset_t *oset) 580 { 581 const sigset_t *p = set; 582 sigset_t newset; 583 584 if (how != SIG_UNBLOCK) { 585 if (set != NULL) { 586 newset = *set; 587 SIGDELSET(newset, SIGCANCEL); 588 p = &newset; 589 } 590 } 591 return (__sys_sigprocmask(how, p, oset)); 592 } 593 594 __weak_reference(_pthread_sigmask, pthread_sigmask); 595 596 int 597 _pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) 598 { 599 if (_sigprocmask(how, set, oset)) 600 return (errno); 601 return (0); 602 } 603 604 __weak_reference(__sigsuspend, sigsuspend); 605 606 int 607 _sigsuspend(const sigset_t * set) 608 { 609 sigset_t newset; 610 611 return (__sys_sigsuspend(thr_remove_thr_signals(set, &newset))); 612 } 613 614 int 615 __sigsuspend(const sigset_t * set) 616 { 617 struct pthread *curthread; 618 sigset_t newset; 619 int ret, old; 620 621 curthread = _get_curthread(); 622 623 old = curthread->in_sigsuspend; 624 curthread->in_sigsuspend = 1; 625 _thr_cancel_enter(curthread); 626 ret = __sys_sigsuspend(thr_remove_thr_signals(set, &newset)); 627 _thr_cancel_leave(curthread, 1); 628 curthread->in_sigsuspend = old; 629 if (curthread->unblock_sigcancel) { 630 curthread->unblock_sigcancel = 0; 631 SIGEMPTYSET(newset); 632 SIGADDSET(newset, SIGCANCEL); 633 __sys_sigprocmask(SIG_UNBLOCK, &newset, NULL); 634 } 635 636 return (ret); 637 } 638 639 __weak_reference(___sigwait, sigwait); 640 __weak_reference(__sigtimedwait, sigtimedwait); 641 __weak_reference(__sigwaitinfo, sigwaitinfo); 642 643 int 644 _sigtimedwait(const sigset_t *set, siginfo_t *info, 645 const struct timespec * timeout) 646 { 647 sigset_t newset; 648 649 return (__sys_sigtimedwait(thr_remove_thr_signals(set, &newset), info, 650 timeout)); 651 } 652 653 /* 654 * Cancellation behavior: 655 * Thread may be canceled at start, if thread got signal, 656 * it is not canceled. 657 */ 658 int 659 __sigtimedwait(const sigset_t *set, siginfo_t *info, 660 const struct timespec * timeout) 661 { 662 struct pthread *curthread = _get_curthread(); 663 sigset_t newset; 664 int ret; 665 666 _thr_cancel_enter(curthread); 667 ret = __sys_sigtimedwait(thr_remove_thr_signals(set, &newset), info, 668 timeout); 669 _thr_cancel_leave(curthread, (ret == -1)); 670 return (ret); 671 } 672 673 int 674 _sigwaitinfo(const sigset_t *set, siginfo_t *info) 675 { 676 sigset_t newset; 677 678 return (__sys_sigwaitinfo(thr_remove_thr_signals(set, &newset), info)); 679 } 680 681 /* 682 * Cancellation behavior: 683 * Thread may be canceled at start, if thread got signal, 684 * it is not canceled. 685 */ 686 int 687 __sigwaitinfo(const sigset_t *set, siginfo_t *info) 688 { 689 struct pthread *curthread = _get_curthread(); 690 sigset_t newset; 691 int ret; 692 693 _thr_cancel_enter(curthread); 694 ret = __sys_sigwaitinfo(thr_remove_thr_signals(set, &newset), info); 695 _thr_cancel_leave(curthread, ret == -1); 696 return (ret); 697 } 698 699 int 700 _sigwait(const sigset_t *set, int *sig) 701 { 702 sigset_t newset; 703 704 return (__sys_sigwait(thr_remove_thr_signals(set, &newset), sig)); 705 } 706 707 /* 708 * Cancellation behavior: 709 * Thread may be canceled at start, if thread got signal, 710 * it is not canceled. 711 */ 712 int 713 ___sigwait(const sigset_t *set, int *sig) 714 { 715 struct pthread *curthread = _get_curthread(); 716 sigset_t newset; 717 int ret; 718 719 do { 720 _thr_cancel_enter(curthread); 721 ret = __sys_sigwait(thr_remove_thr_signals(set, &newset), sig); 722 _thr_cancel_leave(curthread, (ret != 0)); 723 } while (ret == EINTR); 724 return (ret); 725 } 726 727 __weak_reference(_setcontext, setcontext); 728 int 729 _setcontext(const ucontext_t *ucp) 730 { 731 ucontext_t uc; 732 733 if (ucp == NULL) { 734 errno = EINVAL; 735 return (-1); 736 } 737 if (!SIGISMEMBER(uc.uc_sigmask, SIGCANCEL)) 738 return __sys_setcontext(ucp); 739 (void) memcpy(&uc, ucp, sizeof(uc)); 740 SIGDELSET(uc.uc_sigmask, SIGCANCEL); 741 return __sys_setcontext(&uc); 742 } 743 744 __weak_reference(_swapcontext, swapcontext); 745 int 746 _swapcontext(ucontext_t *oucp, const ucontext_t *ucp) 747 { 748 ucontext_t uc; 749 750 if (oucp == NULL || ucp == NULL) { 751 errno = EINVAL; 752 return (-1); 753 } 754 if (SIGISMEMBER(ucp->uc_sigmask, SIGCANCEL)) { 755 (void) memcpy(&uc, ucp, sizeof(uc)); 756 SIGDELSET(uc.uc_sigmask, SIGCANCEL); 757 ucp = &uc; 758 } 759 return __sys_swapcontext(oucp, ucp); 760 } 761