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 <sys/syscall.h> 34 #include <signal.h> 35 #include <errno.h> 36 #include <stdlib.h> 37 #include <string.h> 38 #include <pthread.h> 39 #include "un-namespace.h" 40 #include "libc_private.h" 41 42 #include "libc_private.h" 43 #include "thr_private.h" 44 45 /* #define DEBUG_SIGNAL */ 46 #ifdef DEBUG_SIGNAL 47 #define DBG_MSG stdout_debug 48 #else 49 #define DBG_MSG(x...) 50 #endif 51 52 struct usigaction { 53 struct sigaction sigact; 54 struct urwlock lock; 55 }; 56 57 static struct usigaction _thr_sigact[_SIG_MAXSIG]; 58 59 static inline struct usigaction * 60 __libc_sigaction_slot(int signo) 61 { 62 63 return (&_thr_sigact[signo - 1]); 64 } 65 66 static void thr_sighandler(int, siginfo_t *, void *); 67 static void handle_signal(struct sigaction *, int, siginfo_t *, ucontext_t *); 68 static void check_deferred_signal(struct pthread *); 69 static void check_suspend(struct pthread *); 70 static void check_cancel(struct pthread *curthread, ucontext_t *ucp); 71 72 int _sigtimedwait(const sigset_t *set, siginfo_t *info, 73 const struct timespec * timeout); 74 int _sigwaitinfo(const sigset_t *set, siginfo_t *info); 75 int _sigwait(const sigset_t *set, int *sig); 76 int _setcontext(const ucontext_t *); 77 int _swapcontext(ucontext_t *, const ucontext_t *); 78 79 static const sigset_t _thr_deferset={{ 80 0xffffffff & ~(_SIG_BIT(SIGBUS)|_SIG_BIT(SIGILL)|_SIG_BIT(SIGFPE)| 81 _SIG_BIT(SIGSEGV)|_SIG_BIT(SIGTRAP)|_SIG_BIT(SIGSYS)), 82 0xffffffff, 83 0xffffffff, 84 0xffffffff}}; 85 86 static const sigset_t _thr_maskset={{ 87 0xffffffff, 88 0xffffffff, 89 0xffffffff, 90 0xffffffff}}; 91 92 void 93 _thr_signal_block(struct pthread *curthread) 94 { 95 96 if (curthread->sigblock > 0) { 97 curthread->sigblock++; 98 return; 99 } 100 __sys_sigprocmask(SIG_BLOCK, &_thr_maskset, &curthread->sigmask); 101 curthread->sigblock++; 102 } 103 104 void 105 _thr_signal_unblock(struct pthread *curthread) 106 { 107 if (--curthread->sigblock == 0) 108 __sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL); 109 } 110 111 int 112 _thr_send_sig(struct pthread *thread, int sig) 113 { 114 return thr_kill(thread->tid, sig); 115 } 116 117 static inline void 118 remove_thr_signals(sigset_t *set) 119 { 120 if (SIGISMEMBER(*set, SIGCANCEL)) 121 SIGDELSET(*set, SIGCANCEL); 122 } 123 124 static const sigset_t * 125 thr_remove_thr_signals(const sigset_t *set, sigset_t *newset) 126 { 127 *newset = *set; 128 remove_thr_signals(newset); 129 return (newset); 130 } 131 132 static void 133 sigcancel_handler(int sig __unused, 134 siginfo_t *info __unused, ucontext_t *ucp) 135 { 136 struct pthread *curthread = _get_curthread(); 137 int err; 138 139 if (THR_IN_CRITICAL(curthread)) 140 return; 141 err = errno; 142 check_suspend(curthread); 143 check_cancel(curthread, ucp); 144 errno = err; 145 } 146 147 typedef void (*ohandler)(int sig, int code, struct sigcontext *scp, 148 char *addr, __sighandler_t *catcher); 149 150 /* 151 * The signal handler wrapper is entered with all signal masked. 152 */ 153 static void 154 thr_sighandler(int sig, siginfo_t *info, void *_ucp) 155 { 156 struct pthread *curthread; 157 ucontext_t *ucp; 158 struct sigaction act; 159 struct usigaction *usa; 160 int err; 161 162 err = errno; 163 curthread = _get_curthread(); 164 ucp = _ucp; 165 usa = __libc_sigaction_slot(sig); 166 _thr_rwl_rdlock(&usa->lock); 167 act = usa->sigact; 168 _thr_rwl_unlock(&usa->lock); 169 errno = err; 170 curthread->deferred_run = 0; 171 172 /* 173 * if a thread is in critical region, for example it holds low level locks, 174 * try to defer the signal processing, however if the signal is synchronous 175 * signal, it means a bad thing has happened, this is a programming error, 176 * resuming fault point can not help anything (normally causes deadloop), 177 * so here we let user code handle it immediately. 178 */ 179 if (THR_IN_CRITICAL(curthread) && SIGISMEMBER(_thr_deferset, sig)) { 180 memcpy(&curthread->deferred_sigact, &act, sizeof(struct sigaction)); 181 memcpy(&curthread->deferred_siginfo, info, sizeof(siginfo_t)); 182 curthread->deferred_sigmask = ucp->uc_sigmask; 183 /* mask all signals, we will restore it later. */ 184 ucp->uc_sigmask = _thr_deferset; 185 return; 186 } 187 188 handle_signal(&act, sig, info, ucp); 189 } 190 191 static void 192 handle_signal(struct sigaction *actp, int sig, siginfo_t *info, ucontext_t *ucp) 193 { 194 struct pthread *curthread = _get_curthread(); 195 ucontext_t uc2; 196 __siginfohandler_t *sigfunc; 197 int cancel_point; 198 int cancel_async; 199 int cancel_enable; 200 int in_sigsuspend; 201 int err; 202 203 /* add previous level mask */ 204 SIGSETOR(actp->sa_mask, ucp->uc_sigmask); 205 206 /* add this signal's mask */ 207 if (!(actp->sa_flags & SA_NODEFER)) 208 SIGADDSET(actp->sa_mask, sig); 209 210 in_sigsuspend = curthread->in_sigsuspend; 211 curthread->in_sigsuspend = 0; 212 213 /* 214 * If thread is in deferred cancellation mode, disable cancellation 215 * in signal handler. 216 * If user signal handler calls a cancellation point function, e.g, 217 * it calls write() to write data to file, because write() is a 218 * cancellation point, the thread is immediately cancelled if 219 * cancellation is pending, to avoid this problem while thread is in 220 * deferring mode, cancellation is temporarily disabled. 221 */ 222 cancel_point = curthread->cancel_point; 223 cancel_async = curthread->cancel_async; 224 cancel_enable = curthread->cancel_enable; 225 curthread->cancel_point = 0; 226 if (!cancel_async) 227 curthread->cancel_enable = 0; 228 229 /* restore correct mask before calling user handler */ 230 __sys_sigprocmask(SIG_SETMASK, &actp->sa_mask, NULL); 231 232 sigfunc = actp->sa_sigaction; 233 234 /* 235 * We have already reset cancellation point flags, so if user's code 236 * longjmp()s out of its signal handler, wish its jmpbuf was set 237 * outside of a cancellation point, in most cases, this would be 238 * true. However, there is no way to save cancel_enable in jmpbuf, 239 * so after setjmps() returns once more, the user code may need to 240 * re-set cancel_enable flag by calling pthread_setcancelstate(). 241 */ 242 if ((actp->sa_flags & SA_SIGINFO) != 0) { 243 sigfunc(sig, info, ucp); 244 } else { 245 ((ohandler)sigfunc)(sig, info->si_code, 246 (struct sigcontext *)ucp, info->si_addr, 247 (__sighandler_t *)sigfunc); 248 } 249 err = errno; 250 251 curthread->in_sigsuspend = in_sigsuspend; 252 curthread->cancel_point = cancel_point; 253 curthread->cancel_enable = cancel_enable; 254 255 memcpy(&uc2, ucp, sizeof(uc2)); 256 SIGDELSET(uc2.uc_sigmask, SIGCANCEL); 257 258 /* reschedule cancellation */ 259 check_cancel(curthread, &uc2); 260 errno = err; 261 syscall(SYS_sigreturn, &uc2); 262 } 263 264 void 265 _thr_ast(struct pthread *curthread) 266 { 267 268 if (!THR_IN_CRITICAL(curthread)) { 269 check_deferred_signal(curthread); 270 check_suspend(curthread); 271 check_cancel(curthread, NULL); 272 } 273 } 274 275 /* reschedule cancellation */ 276 static void 277 check_cancel(struct pthread *curthread, ucontext_t *ucp) 278 { 279 280 if (__predict_true(!curthread->cancel_pending || 281 !curthread->cancel_enable || curthread->no_cancel)) 282 return; 283 284 /* 285 * Otherwise, we are in defer mode, and we are at 286 * cancel point, tell kernel to not block the current 287 * thread on next cancelable system call. 288 * 289 * There are three cases we should call thr_wake() to 290 * turn on TDP_WAKEUP or send SIGCANCEL in kernel: 291 * 1) we are going to call a cancelable system call, 292 * non-zero cancel_point means we are already in 293 * cancelable state, next system call is cancelable. 294 * 2) because _thr_ast() may be called by 295 * THR_CRITICAL_LEAVE() which is used by rtld rwlock 296 * and any libthr internal locks, when rtld rwlock 297 * is used, it is mostly caused by an unresolved PLT. 298 * Those routines may clear the TDP_WAKEUP flag by 299 * invoking some system calls, in those cases, we 300 * also should reenable the flag. 301 * 3) thread is in sigsuspend(), and the syscall insists 302 * on getting a signal before it agrees to return. 303 */ 304 if (curthread->cancel_point) { 305 if (curthread->in_sigsuspend && ucp) { 306 SIGADDSET(ucp->uc_sigmask, SIGCANCEL); 307 curthread->unblock_sigcancel = 1; 308 _thr_send_sig(curthread, SIGCANCEL); 309 } else 310 thr_wake(curthread->tid); 311 } else if (curthread->cancel_async) { 312 /* 313 * asynchronous cancellation mode, act upon 314 * immediately. 315 */ 316 _pthread_exit_mask(PTHREAD_CANCELED, 317 ucp? &ucp->uc_sigmask : NULL); 318 } 319 } 320 321 static void 322 check_deferred_signal(struct pthread *curthread) 323 { 324 ucontext_t *uc; 325 struct sigaction act; 326 siginfo_t info; 327 int uc_len; 328 329 if (__predict_true(curthread->deferred_siginfo.si_signo == 0 || 330 curthread->deferred_run)) 331 return; 332 333 curthread->deferred_run = 1; 334 uc_len = __getcontextx_size(); 335 uc = alloca(uc_len); 336 getcontext(uc); 337 if (curthread->deferred_siginfo.si_signo == 0) { 338 curthread->deferred_run = 0; 339 return; 340 } 341 __fillcontextx2((char *)uc); 342 act = curthread->deferred_sigact; 343 uc->uc_sigmask = curthread->deferred_sigmask; 344 memcpy(&info, &curthread->deferred_siginfo, sizeof(siginfo_t)); 345 /* remove signal */ 346 curthread->deferred_siginfo.si_signo = 0; 347 handle_signal(&act, info.si_signo, &info, uc); 348 } 349 350 static void 351 check_suspend(struct pthread *curthread) 352 { 353 uint32_t cycle; 354 355 if (__predict_true((curthread->flags & 356 (THR_FLAGS_NEED_SUSPEND | THR_FLAGS_SUSPENDED)) 357 != THR_FLAGS_NEED_SUSPEND)) 358 return; 359 if (curthread == _single_thread) 360 return; 361 if (curthread->force_exit) 362 return; 363 364 /* 365 * Blocks SIGCANCEL which other threads must send. 366 */ 367 _thr_signal_block(curthread); 368 369 /* 370 * Increase critical_count, here we don't use THR_LOCK/UNLOCK 371 * because we are leaf code, we don't want to recursively call 372 * ourself. 373 */ 374 curthread->critical_count++; 375 THR_UMUTEX_LOCK(curthread, &(curthread)->lock); 376 while ((curthread->flags & (THR_FLAGS_NEED_SUSPEND | 377 THR_FLAGS_SUSPENDED)) == THR_FLAGS_NEED_SUSPEND) { 378 curthread->cycle++; 379 cycle = curthread->cycle; 380 381 /* Wake the thread suspending us. */ 382 _thr_umtx_wake(&curthread->cycle, INT_MAX, 0); 383 384 /* 385 * if we are from pthread_exit, we don't want to 386 * suspend, just go and die. 387 */ 388 if (curthread->state == PS_DEAD) 389 break; 390 curthread->flags |= THR_FLAGS_SUSPENDED; 391 THR_UMUTEX_UNLOCK(curthread, &(curthread)->lock); 392 _thr_umtx_wait_uint(&curthread->cycle, cycle, NULL, 0); 393 THR_UMUTEX_LOCK(curthread, &(curthread)->lock); 394 curthread->flags &= ~THR_FLAGS_SUSPENDED; 395 } 396 THR_UMUTEX_UNLOCK(curthread, &(curthread)->lock); 397 curthread->critical_count--; 398 399 _thr_signal_unblock(curthread); 400 } 401 402 void 403 _thr_signal_init(int dlopened) 404 { 405 struct sigaction act, nact, oact; 406 struct usigaction *usa; 407 sigset_t oldset; 408 int sig, error; 409 410 if (dlopened) { 411 __sys_sigprocmask(SIG_SETMASK, &_thr_maskset, &oldset); 412 for (sig = 1; sig <= _SIG_MAXSIG; sig++) { 413 if (sig == SIGCANCEL) 414 continue; 415 error = __sys_sigaction(sig, NULL, &oact); 416 if (error == -1 || oact.sa_handler == SIG_DFL || 417 oact.sa_handler == SIG_IGN) 418 continue; 419 usa = __libc_sigaction_slot(sig); 420 usa->sigact = oact; 421 nact = oact; 422 remove_thr_signals(&usa->sigact.sa_mask); 423 nact.sa_flags &= ~SA_NODEFER; 424 nact.sa_flags |= SA_SIGINFO; 425 nact.sa_sigaction = thr_sighandler; 426 nact.sa_mask = _thr_maskset; 427 (void)__sys_sigaction(sig, &nact, NULL); 428 } 429 __sys_sigprocmask(SIG_SETMASK, &oldset, NULL); 430 } 431 432 /* Install SIGCANCEL handler. */ 433 SIGFILLSET(act.sa_mask); 434 act.sa_flags = SA_SIGINFO; 435 act.sa_sigaction = (__siginfohandler_t *)&sigcancel_handler; 436 __sys_sigaction(SIGCANCEL, &act, NULL); 437 438 /* Unblock SIGCANCEL */ 439 SIGEMPTYSET(act.sa_mask); 440 SIGADDSET(act.sa_mask, SIGCANCEL); 441 __sys_sigprocmask(SIG_UNBLOCK, &act.sa_mask, NULL); 442 } 443 444 void 445 _thr_sigact_unload(struct dl_phdr_info *phdr_info) 446 { 447 #if 0 448 struct pthread *curthread = _get_curthread(); 449 struct urwlock *rwlp; 450 struct sigaction *actp; 451 struct usigaction *usa; 452 struct sigaction kact; 453 void (*handler)(int); 454 int sig; 455 456 _thr_signal_block(curthread); 457 for (sig = 1; sig <= _SIG_MAXSIG; sig++) { 458 usa = __libc_sigaction_slot(sig); 459 actp = &usa->sigact; 460 retry: 461 handler = actp->sa_handler; 462 if (handler != SIG_DFL && handler != SIG_IGN && 463 __elf_phdr_match_addr(phdr_info, handler)) { 464 rwlp = &usa->lock; 465 _thr_rwl_wrlock(rwlp); 466 if (handler != actp->sa_handler) { 467 _thr_rwl_unlock(rwlp); 468 goto retry; 469 } 470 actp->sa_handler = SIG_DFL; 471 actp->sa_flags = SA_SIGINFO; 472 SIGEMPTYSET(actp->sa_mask); 473 if (__sys_sigaction(sig, NULL, &kact) == 0 && 474 kact.sa_handler != SIG_DFL && 475 kact.sa_handler != SIG_IGN) 476 __sys_sigaction(sig, actp, NULL); 477 _thr_rwl_unlock(rwlp); 478 } 479 } 480 _thr_signal_unblock(curthread); 481 #endif 482 } 483 484 void 485 _thr_signal_prefork(void) 486 { 487 int i; 488 489 for (i = 1; i <= _SIG_MAXSIG; ++i) 490 _thr_rwl_rdlock(&__libc_sigaction_slot(i)->lock); 491 } 492 493 void 494 _thr_signal_postfork(void) 495 { 496 int i; 497 498 for (i = 1; i <= _SIG_MAXSIG; ++i) 499 _thr_rwl_unlock(&__libc_sigaction_slot(i)->lock); 500 } 501 502 void 503 _thr_signal_postfork_child(void) 504 { 505 int i; 506 507 for (i = 1; i <= _SIG_MAXSIG; ++i) { 508 bzero(&__libc_sigaction_slot(i) -> lock, 509 sizeof(struct urwlock)); 510 } 511 } 512 513 void 514 _thr_signal_deinit(void) 515 { 516 } 517 518 int 519 __thr_sigaction(int sig, const struct sigaction *act, struct sigaction *oact) 520 { 521 struct sigaction newact, oldact, oldact2; 522 sigset_t oldset; 523 struct usigaction *usa; 524 int ret, err; 525 526 if (!_SIG_VALID(sig) || sig == SIGCANCEL) { 527 errno = EINVAL; 528 return (-1); 529 } 530 531 ret = 0; 532 err = 0; 533 usa = __libc_sigaction_slot(sig); 534 535 __sys_sigprocmask(SIG_SETMASK, &_thr_maskset, &oldset); 536 _thr_rwl_wrlock(&usa->lock); 537 538 if (act != NULL) { 539 oldact2 = usa->sigact; 540 newact = *act; 541 542 /* 543 * if a new sig handler is SIG_DFL or SIG_IGN, 544 * don't remove old handler from __libc_sigact[], 545 * so deferred signals still can use the handlers, 546 * multiple threads invoking sigaction itself is 547 * a race condition, so it is not a problem. 548 */ 549 if (newact.sa_handler != SIG_DFL && 550 newact.sa_handler != SIG_IGN) { 551 usa->sigact = newact; 552 remove_thr_signals(&usa->sigact.sa_mask); 553 newact.sa_flags &= ~SA_NODEFER; 554 newact.sa_flags |= SA_SIGINFO; 555 newact.sa_sigaction = thr_sighandler; 556 newact.sa_mask = _thr_maskset; /* mask all signals */ 557 } 558 ret = __sys_sigaction(sig, &newact, &oldact); 559 if (ret == -1) { 560 err = errno; 561 usa->sigact = oldact2; 562 } 563 } else if (oact != NULL) { 564 ret = __sys_sigaction(sig, NULL, &oldact); 565 err = errno; 566 } 567 568 if (oldact.sa_handler != SIG_DFL && oldact.sa_handler != SIG_IGN) { 569 if (act != NULL) 570 oldact = oldact2; 571 else if (oact != NULL) 572 oldact = usa->sigact; 573 } 574 575 _thr_rwl_unlock(&usa->lock); 576 __sys_sigprocmask(SIG_SETMASK, &oldset, NULL); 577 578 if (ret == 0) { 579 if (oact != NULL) 580 *oact = oldact; 581 } else { 582 errno = err; 583 } 584 return (ret); 585 } 586 587 int 588 __thr_sigprocmask(int how, const sigset_t *set, sigset_t *oset) 589 { 590 const sigset_t *p = set; 591 sigset_t newset; 592 593 if (how != SIG_UNBLOCK) { 594 if (set != NULL) { 595 newset = *set; 596 SIGDELSET(newset, SIGCANCEL); 597 p = &newset; 598 } 599 } 600 return (__sys_sigprocmask(how, p, oset)); 601 } 602 603 __weak_reference(_pthread_sigmask, pthread_sigmask); 604 605 int 606 _pthread_sigmask(int how, const sigset_t *set, sigset_t *oset) 607 { 608 609 if (__thr_sigprocmask(how, set, oset)) 610 return (errno); 611 return (0); 612 } 613 614 int 615 _sigsuspend(const sigset_t * set) 616 { 617 sigset_t newset; 618 619 return (__sys_sigsuspend(thr_remove_thr_signals(set, &newset))); 620 } 621 622 int 623 __thr_sigsuspend(const sigset_t * set) 624 { 625 struct pthread *curthread; 626 sigset_t newset; 627 int ret, old; 628 629 curthread = _get_curthread(); 630 631 old = curthread->in_sigsuspend; 632 curthread->in_sigsuspend = 1; 633 _thr_cancel_enter(curthread); 634 ret = __sys_sigsuspend(thr_remove_thr_signals(set, &newset)); 635 _thr_cancel_leave(curthread, 1); 636 curthread->in_sigsuspend = old; 637 if (curthread->unblock_sigcancel) { 638 curthread->unblock_sigcancel = 0; 639 SIGEMPTYSET(newset); 640 SIGADDSET(newset, SIGCANCEL); 641 __sys_sigprocmask(SIG_UNBLOCK, &newset, NULL); 642 } 643 644 return (ret); 645 } 646 647 int 648 _sigtimedwait(const sigset_t *set, siginfo_t *info, 649 const struct timespec * timeout) 650 { 651 sigset_t newset; 652 653 return (__sys_sigtimedwait(thr_remove_thr_signals(set, &newset), info, 654 timeout)); 655 } 656 657 /* 658 * Cancellation behavior: 659 * Thread may be canceled at start, if thread got signal, 660 * it is not canceled. 661 */ 662 int 663 __thr_sigtimedwait(const sigset_t *set, siginfo_t *info, 664 const struct timespec * timeout) 665 { 666 struct pthread *curthread = _get_curthread(); 667 sigset_t newset; 668 int ret; 669 670 _thr_cancel_enter(curthread); 671 ret = __sys_sigtimedwait(thr_remove_thr_signals(set, &newset), info, 672 timeout); 673 _thr_cancel_leave(curthread, (ret == -1)); 674 return (ret); 675 } 676 677 int 678 _sigwaitinfo(const sigset_t *set, siginfo_t *info) 679 { 680 sigset_t newset; 681 682 return (__sys_sigwaitinfo(thr_remove_thr_signals(set, &newset), info)); 683 } 684 685 /* 686 * Cancellation behavior: 687 * Thread may be canceled at start, if thread got signal, 688 * it is not canceled. 689 */ 690 int 691 __thr_sigwaitinfo(const sigset_t *set, siginfo_t *info) 692 { 693 struct pthread *curthread = _get_curthread(); 694 sigset_t newset; 695 int ret; 696 697 _thr_cancel_enter(curthread); 698 ret = __sys_sigwaitinfo(thr_remove_thr_signals(set, &newset), info); 699 _thr_cancel_leave(curthread, ret == -1); 700 return (ret); 701 } 702 703 int 704 _sigwait(const sigset_t *set, int *sig) 705 { 706 sigset_t newset; 707 708 return (__sys_sigwait(thr_remove_thr_signals(set, &newset), sig)); 709 } 710 711 /* 712 * Cancellation behavior: 713 * Thread may be canceled at start, if thread got signal, 714 * it is not canceled. 715 */ 716 int 717 __thr_sigwait(const sigset_t *set, int *sig) 718 { 719 struct pthread *curthread = _get_curthread(); 720 sigset_t newset; 721 int ret; 722 723 do { 724 _thr_cancel_enter(curthread); 725 ret = __sys_sigwait(thr_remove_thr_signals(set, &newset), sig); 726 _thr_cancel_leave(curthread, (ret != 0)); 727 } while (ret == EINTR); 728 return (ret); 729 } 730 731 int 732 __thr_setcontext(const ucontext_t *ucp) 733 { 734 ucontext_t uc; 735 736 if (ucp == NULL) { 737 errno = EINVAL; 738 return (-1); 739 } 740 if (!SIGISMEMBER(uc.uc_sigmask, SIGCANCEL)) 741 return __sys_setcontext(ucp); 742 (void) memcpy(&uc, ucp, sizeof(uc)); 743 SIGDELSET(uc.uc_sigmask, SIGCANCEL); 744 return (__sys_setcontext(&uc)); 745 } 746 747 int 748 __thr_swapcontext(ucontext_t *oucp, const ucontext_t *ucp) 749 { 750 ucontext_t uc; 751 752 if (oucp == NULL || ucp == NULL) { 753 errno = EINVAL; 754 return (-1); 755 } 756 if (SIGISMEMBER(ucp->uc_sigmask, SIGCANCEL)) { 757 (void) memcpy(&uc, ucp, sizeof(uc)); 758 SIGDELSET(uc.uc_sigmask, SIGCANCEL); 759 ucp = &uc; 760 } 761 return (__sys_swapcontext(oucp, ucp)); 762 } 763