1 /* $NetBSD: sys_sig.c,v 1.37 2012/02/19 21:06:57 rmind Exp $ */ 2 3 /*- 4 * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Copyright (c) 1982, 1986, 1989, 1991, 1993 34 * The Regents of the University of California. All rights reserved. 35 * (c) UNIX System Laboratories, Inc. 36 * All or some portions of this file are derived from material licensed 37 * to the University of California by American Telephone and Telegraph 38 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 39 * the permission of UNIX System Laboratories, Inc. 40 * 41 * Redistribution and use in source and binary forms, with or without 42 * modification, are permitted provided that the following conditions 43 * are met: 44 * 1. Redistributions of source code must retain the above copyright 45 * notice, this list of conditions and the following disclaimer. 46 * 2. Redistributions in binary form must reproduce the above copyright 47 * notice, this list of conditions and the following disclaimer in the 48 * documentation and/or other materials provided with the distribution. 49 * 3. Neither the name of the University nor the names of its contributors 50 * may be used to endorse or promote products derived from this software 51 * without specific prior written permission. 52 * 53 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 54 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 55 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 56 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 57 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 58 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 59 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 60 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 61 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 62 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 63 * SUCH DAMAGE. 64 * 65 * @(#)kern_sig.c 8.14 (Berkeley) 5/14/95 66 */ 67 68 #include <sys/cdefs.h> 69 __KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.37 2012/02/19 21:06:57 rmind Exp $"); 70 71 #include <sys/param.h> 72 #include <sys/kernel.h> 73 #include <sys/signalvar.h> 74 #include <sys/proc.h> 75 #include <sys/pool.h> 76 #include <sys/syscallargs.h> 77 #include <sys/kauth.h> 78 #include <sys/wait.h> 79 #include <sys/kmem.h> 80 #include <sys/module.h> 81 82 int 83 sys___sigaction_sigtramp(struct lwp *l, 84 const struct sys___sigaction_sigtramp_args *uap, register_t *retval) 85 { 86 /* { 87 syscallarg(int) signum; 88 syscallarg(const struct sigaction *) nsa; 89 syscallarg(struct sigaction *) osa; 90 syscallarg(void *) tramp; 91 syscallarg(int) vers; 92 } */ 93 struct sigaction nsa, osa; 94 int error; 95 96 if (SCARG(uap, nsa)) { 97 error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa)); 98 if (error) 99 return (error); 100 } 101 error = sigaction1(l, SCARG(uap, signum), 102 SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0, 103 SCARG(uap, tramp), SCARG(uap, vers)); 104 if (error) 105 return (error); 106 if (SCARG(uap, osa)) { 107 error = copyout(&osa, SCARG(uap, osa), sizeof(osa)); 108 if (error) 109 return (error); 110 } 111 return 0; 112 } 113 114 /* 115 * Manipulate signal mask. Note that we receive new mask, not pointer, and 116 * return old mask as return value; the library stub does the rest. 117 */ 118 int 119 sys___sigprocmask14(struct lwp *l, const struct sys___sigprocmask14_args *uap, 120 register_t *retval) 121 { 122 /* { 123 syscallarg(int) how; 124 syscallarg(const sigset_t *) set; 125 syscallarg(sigset_t *) oset; 126 } */ 127 struct proc *p = l->l_proc; 128 sigset_t nss, oss; 129 int error; 130 131 if (SCARG(uap, set)) { 132 error = copyin(SCARG(uap, set), &nss, sizeof(nss)); 133 if (error) 134 return error; 135 } 136 mutex_enter(p->p_lock); 137 error = sigprocmask1(l, SCARG(uap, how), 138 SCARG(uap, set) ? &nss : 0, SCARG(uap, oset) ? &oss : 0); 139 mutex_exit(p->p_lock); 140 if (error) 141 return error; 142 if (SCARG(uap, oset)) { 143 error = copyout(&oss, SCARG(uap, oset), sizeof(oss)); 144 if (error) 145 return error; 146 } 147 return 0; 148 } 149 150 int 151 sys___sigpending14(struct lwp *l, const struct sys___sigpending14_args *uap, 152 register_t *retval) 153 { 154 /* { 155 syscallarg(sigset_t *) set; 156 } */ 157 sigset_t ss; 158 159 sigpending1(l, &ss); 160 return copyout(&ss, SCARG(uap, set), sizeof(ss)); 161 } 162 163 /* 164 * Suspend process until signal, providing mask to be set in the meantime. 165 * Note nonstandard calling convention: libc stub passes mask, not pointer, 166 * to save a copyin. 167 */ 168 int 169 sys___sigsuspend14(struct lwp *l, const struct sys___sigsuspend14_args *uap, 170 register_t *retval) 171 { 172 /* { 173 syscallarg(const sigset_t *) set; 174 } */ 175 sigset_t ss; 176 int error; 177 178 if (SCARG(uap, set)) { 179 error = copyin(SCARG(uap, set), &ss, sizeof(ss)); 180 if (error) 181 return error; 182 } 183 return sigsuspend1(l, SCARG(uap, set) ? &ss : 0); 184 } 185 186 int 187 sys___sigaltstack14(struct lwp *l, const struct sys___sigaltstack14_args *uap, 188 register_t *retval) 189 { 190 /* { 191 syscallarg(const struct sigaltstack *) nss; 192 syscallarg(struct sigaltstack *) oss; 193 } */ 194 struct sigaltstack nss, oss; 195 int error; 196 197 if (SCARG(uap, nss)) { 198 error = copyin(SCARG(uap, nss), &nss, sizeof(nss)); 199 if (error) 200 return error; 201 } 202 error = sigaltstack1(l, 203 SCARG(uap, nss) ? &nss : 0, SCARG(uap, oss) ? &oss : 0); 204 if (error) 205 return error; 206 if (SCARG(uap, oss)) { 207 error = copyout(&oss, SCARG(uap, oss), sizeof(oss)); 208 if (error) 209 return error; 210 } 211 return 0; 212 } 213 214 215 static int 216 kill1(struct lwp *l, pid_t pid, ksiginfo_t *ksi, register_t *retval) 217 { 218 int error; 219 struct proc *p; 220 221 if ((u_int)ksi->ksi_signo >= NSIG) 222 return EINVAL; 223 224 if (pid != l->l_proc->p_pid) { 225 if (ksi->ksi_pid != l->l_proc->p_pid) 226 return EPERM; 227 228 if (ksi->ksi_uid != kauth_cred_geteuid(l->l_cred)) 229 return EPERM; 230 231 switch (ksi->ksi_code) { 232 case SI_USER: 233 case SI_QUEUE: 234 break; 235 default: 236 return EPERM; 237 } 238 } 239 240 if (pid > 0) { 241 /* kill single process */ 242 mutex_enter(proc_lock); 243 p = proc_find(pid); 244 if (p == NULL) { 245 mutex_exit(proc_lock); 246 return ESRCH; 247 } 248 mutex_enter(p->p_lock); 249 error = kauth_authorize_process(l->l_cred, 250 KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(ksi->ksi_signo), 251 NULL, NULL); 252 if (!error && ksi->ksi_signo) { 253 kpsignal2(p, ksi); 254 } 255 mutex_exit(p->p_lock); 256 mutex_exit(proc_lock); 257 return error; 258 } 259 260 switch (pid) { 261 case -1: /* broadcast signal */ 262 return killpg1(l, ksi, 0, 1); 263 case 0: /* signal own process group */ 264 return killpg1(l, ksi, 0, 0); 265 default: /* negative explicit process group */ 266 return killpg1(l, ksi, -pid, 0); 267 } 268 /* NOTREACHED */ 269 } 270 271 int 272 sys_sigqueueinfo(struct lwp *l, const struct sys_sigqueueinfo_args *uap, 273 register_t *retval) 274 { 275 /* { 276 syscallarg(pid_t int) pid; 277 syscallarg(const siginfo_t *) info; 278 } */ 279 ksiginfo_t ksi; 280 int error; 281 282 KSI_INIT(&ksi); 283 284 if ((error = copyin(&SCARG(uap, info)->_info, &ksi.ksi_info, 285 sizeof(ksi.ksi_info))) != 0) 286 return error; 287 288 return kill1(l, SCARG(uap, pid), &ksi, retval); 289 } 290 291 int 292 sys_kill(struct lwp *l, const struct sys_kill_args *uap, register_t *retval) 293 { 294 /* { 295 syscallarg(pid_t) pid; 296 syscallarg(int) signum; 297 } */ 298 ksiginfo_t ksi; 299 300 KSI_INIT(&ksi); 301 302 ksi.ksi_signo = SCARG(uap, signum); 303 ksi.ksi_code = SI_USER; 304 ksi.ksi_pid = l->l_proc->p_pid; 305 ksi.ksi_uid = kauth_cred_geteuid(l->l_cred); 306 307 return kill1(l, SCARG(uap, pid), &ksi, retval); 308 } 309 310 int 311 sys_getcontext(struct lwp *l, const struct sys_getcontext_args *uap, 312 register_t *retval) 313 { 314 /* { 315 syscallarg(struct __ucontext *) ucp; 316 } */ 317 struct proc *p = l->l_proc; 318 ucontext_t uc; 319 320 memset(&uc, 0, sizeof(uc)); 321 322 mutex_enter(p->p_lock); 323 getucontext(l, &uc); 324 mutex_exit(p->p_lock); 325 326 return copyout(&uc, SCARG(uap, ucp), sizeof (*SCARG(uap, ucp))); 327 } 328 329 int 330 sys_setcontext(struct lwp *l, const struct sys_setcontext_args *uap, 331 register_t *retval) 332 { 333 /* { 334 syscallarg(const ucontext_t *) ucp; 335 } */ 336 struct proc *p = l->l_proc; 337 ucontext_t uc; 338 int error; 339 340 error = copyin(SCARG(uap, ucp), &uc, sizeof (uc)); 341 if (error) 342 return error; 343 if ((uc.uc_flags & _UC_CPU) == 0) 344 return EINVAL; 345 mutex_enter(p->p_lock); 346 error = setucontext(l, &uc); 347 mutex_exit(p->p_lock); 348 if (error) 349 return error; 350 351 return EJUSTRETURN; 352 } 353 354 /* 355 * sigtimedwait(2) system call, used also for implementation 356 * of sigwaitinfo() and sigwait(). 357 * 358 * This only handles single LWP in signal wait. libpthread provides 359 * it's own sigtimedwait() wrapper to DTRT WRT individual threads. 360 */ 361 int 362 sys_____sigtimedwait50(struct lwp *l, 363 const struct sys_____sigtimedwait50_args *uap, register_t *retval) 364 { 365 366 return sigtimedwait1(l, uap, retval, copyin, copyout, copyin, copyout); 367 } 368 369 int 370 sigaction1(struct lwp *l, int signum, const struct sigaction *nsa, 371 struct sigaction *osa, const void *tramp, int vers) 372 { 373 struct proc *p; 374 struct sigacts *ps; 375 sigset_t tset; 376 int prop, error; 377 ksiginfoq_t kq; 378 static bool v0v1valid; 379 380 if (signum <= 0 || signum >= NSIG) 381 return EINVAL; 382 383 p = l->l_proc; 384 error = 0; 385 ksiginfo_queue_init(&kq); 386 387 /* 388 * Trampoline ABI version 0 is reserved for the legacy kernel 389 * provided on-stack trampoline. Conversely, if we are using a 390 * non-0 ABI version, we must have a trampoline. Only validate the 391 * vers if a new sigaction was supplied. Emulations use legacy 392 * kernel trampolines with version 0, alternatively check for that 393 * too. 394 * 395 * If version < 2, we try to autoload the compat module. Note 396 * that we interlock with the unload check in compat_modcmd() 397 * using kernconfig_lock. If the autoload fails, we don't try it 398 * again for this process. 399 */ 400 if (nsa != NULL) { 401 if (__predict_false(vers < 2) && 402 (p->p_lflag & PL_SIGCOMPAT) == 0) { 403 kernconfig_lock(); 404 if (sendsig_sigcontext_vec == NULL) { 405 (void)module_autoload("compat", 406 MODULE_CLASS_ANY); 407 } 408 if (sendsig_sigcontext_vec != NULL) { 409 /* 410 * We need to remember if the 411 * sigcontext method may be useable, 412 * because libc may use it even 413 * if siginfo is available. 414 */ 415 v0v1valid = true; 416 } 417 mutex_enter(proc_lock); 418 /* 419 * Prevent unload of compat module while 420 * this process remains. 421 */ 422 p->p_lflag |= PL_SIGCOMPAT; 423 mutex_exit(proc_lock); 424 kernconfig_unlock(); 425 } 426 427 switch (vers) { 428 case 0: 429 /* sigcontext, kernel supplied trampoline. */ 430 if (tramp != NULL || !v0v1valid) { 431 return EINVAL; 432 } 433 break; 434 case 1: 435 /* sigcontext, user supplied trampoline. */ 436 if (tramp == NULL || !v0v1valid) { 437 return EINVAL; 438 } 439 break; 440 case 2: 441 case 3: 442 /* siginfo, user supplied trampoline. */ 443 if (tramp == NULL) { 444 return EINVAL; 445 } 446 break; 447 default: 448 return EINVAL; 449 } 450 } 451 452 mutex_enter(p->p_lock); 453 454 ps = p->p_sigacts; 455 if (osa) 456 *osa = SIGACTION_PS(ps, signum); 457 if (!nsa) 458 goto out; 459 460 prop = sigprop[signum]; 461 if ((nsa->sa_flags & ~SA_ALLBITS) || (prop & SA_CANTMASK)) { 462 error = EINVAL; 463 goto out; 464 } 465 466 SIGACTION_PS(ps, signum) = *nsa; 467 ps->sa_sigdesc[signum].sd_tramp = tramp; 468 ps->sa_sigdesc[signum].sd_vers = vers; 469 sigminusset(&sigcantmask, &SIGACTION_PS(ps, signum).sa_mask); 470 471 if ((prop & SA_NORESET) != 0) 472 SIGACTION_PS(ps, signum).sa_flags &= ~SA_RESETHAND; 473 474 if (signum == SIGCHLD) { 475 if (nsa->sa_flags & SA_NOCLDSTOP) 476 p->p_sflag |= PS_NOCLDSTOP; 477 else 478 p->p_sflag &= ~PS_NOCLDSTOP; 479 if (nsa->sa_flags & SA_NOCLDWAIT) { 480 /* 481 * Paranoia: since SA_NOCLDWAIT is implemented by 482 * reparenting the dying child to PID 1 (and trust 483 * it to reap the zombie), PID 1 itself is forbidden 484 * to set SA_NOCLDWAIT. 485 */ 486 if (p->p_pid == 1) 487 p->p_flag &= ~PK_NOCLDWAIT; 488 else 489 p->p_flag |= PK_NOCLDWAIT; 490 } else 491 p->p_flag &= ~PK_NOCLDWAIT; 492 493 if (nsa->sa_handler == SIG_IGN) { 494 /* 495 * Paranoia: same as above. 496 */ 497 if (p->p_pid == 1) 498 p->p_flag &= ~PK_CLDSIGIGN; 499 else 500 p->p_flag |= PK_CLDSIGIGN; 501 } else 502 p->p_flag &= ~PK_CLDSIGIGN; 503 } 504 505 if ((nsa->sa_flags & SA_NODEFER) == 0) 506 sigaddset(&SIGACTION_PS(ps, signum).sa_mask, signum); 507 else 508 sigdelset(&SIGACTION_PS(ps, signum).sa_mask, signum); 509 510 /* 511 * Set bit in p_sigctx.ps_sigignore for signals that are set to 512 * SIG_IGN, and for signals set to SIG_DFL where the default is to 513 * ignore. However, don't put SIGCONT in p_sigctx.ps_sigignore, as 514 * we have to restart the process. 515 */ 516 if (nsa->sa_handler == SIG_IGN || 517 (nsa->sa_handler == SIG_DFL && (prop & SA_IGNORE) != 0)) { 518 /* Never to be seen again. */ 519 sigemptyset(&tset); 520 sigaddset(&tset, signum); 521 sigclearall(p, &tset, &kq); 522 if (signum != SIGCONT) { 523 /* Easier in psignal */ 524 sigaddset(&p->p_sigctx.ps_sigignore, signum); 525 } 526 sigdelset(&p->p_sigctx.ps_sigcatch, signum); 527 } else { 528 sigdelset(&p->p_sigctx.ps_sigignore, signum); 529 if (nsa->sa_handler == SIG_DFL) 530 sigdelset(&p->p_sigctx.ps_sigcatch, signum); 531 else 532 sigaddset(&p->p_sigctx.ps_sigcatch, signum); 533 } 534 535 /* 536 * Previously held signals may now have become visible. Ensure that 537 * we check for them before returning to userspace. 538 */ 539 if (sigispending(l, 0)) { 540 lwp_lock(l); 541 l->l_flag |= LW_PENDSIG; 542 lwp_unlock(l); 543 } 544 out: 545 mutex_exit(p->p_lock); 546 ksiginfo_queue_drain(&kq); 547 548 return error; 549 } 550 551 int 552 sigprocmask1(struct lwp *l, int how, const sigset_t *nss, sigset_t *oss) 553 { 554 sigset_t *mask = &l->l_sigmask; 555 bool more; 556 557 KASSERT(mutex_owned(l->l_proc->p_lock)); 558 559 if (oss) { 560 *oss = *mask; 561 } 562 563 if (nss == NULL) { 564 return 0; 565 } 566 567 switch (how) { 568 case SIG_BLOCK: 569 sigplusset(nss, mask); 570 more = false; 571 break; 572 case SIG_UNBLOCK: 573 sigminusset(nss, mask); 574 more = true; 575 break; 576 case SIG_SETMASK: 577 *mask = *nss; 578 more = true; 579 break; 580 default: 581 return EINVAL; 582 } 583 sigminusset(&sigcantmask, mask); 584 if (more && sigispending(l, 0)) { 585 /* 586 * Check for pending signals on return to user. 587 */ 588 lwp_lock(l); 589 l->l_flag |= LW_PENDSIG; 590 lwp_unlock(l); 591 } 592 return 0; 593 } 594 595 void 596 sigpending1(struct lwp *l, sigset_t *ss) 597 { 598 struct proc *p = l->l_proc; 599 600 mutex_enter(p->p_lock); 601 *ss = l->l_sigpend.sp_set; 602 sigplusset(&p->p_sigpend.sp_set, ss); 603 mutex_exit(p->p_lock); 604 } 605 606 void 607 sigsuspendsetup(struct lwp *l, const sigset_t *ss) 608 { 609 struct proc *p = l->l_proc; 610 611 /* 612 * When returning from sigsuspend/pselect/pollts, we want 613 * the old mask to be restored after the 614 * signal handler has finished. Thus, we 615 * save it here and mark the sigctx structure 616 * to indicate this. 617 */ 618 mutex_enter(p->p_lock); 619 l->l_sigrestore = 1; 620 l->l_sigoldmask = l->l_sigmask; 621 l->l_sigmask = *ss; 622 sigminusset(&sigcantmask, &l->l_sigmask); 623 624 /* Check for pending signals when sleeping. */ 625 if (sigispending(l, 0)) { 626 lwp_lock(l); 627 l->l_flag |= LW_PENDSIG; 628 lwp_unlock(l); 629 } 630 mutex_exit(p->p_lock); 631 } 632 633 void 634 sigsuspendteardown(struct lwp *l) 635 { 636 struct proc *p = l->l_proc; 637 638 mutex_enter(p->p_lock); 639 /* Check for pending signals when sleeping. */ 640 if (l->l_sigrestore) { 641 if (sigispending(l, 0)) { 642 lwp_lock(l); 643 l->l_flag |= LW_PENDSIG; 644 lwp_unlock(l); 645 } else { 646 l->l_sigrestore = 0; 647 l->l_sigmask = l->l_sigoldmask; 648 } 649 } 650 mutex_exit(p->p_lock); 651 } 652 653 int 654 sigsuspend1(struct lwp *l, const sigset_t *ss) 655 { 656 657 if (ss) 658 sigsuspendsetup(l, ss); 659 660 while (kpause("pause", true, 0, NULL) == 0) 661 ; 662 663 /* always return EINTR rather than ERESTART... */ 664 return EINTR; 665 } 666 667 int 668 sigaltstack1(struct lwp *l, const struct sigaltstack *nss, 669 struct sigaltstack *oss) 670 { 671 struct proc *p = l->l_proc; 672 int error = 0; 673 674 mutex_enter(p->p_lock); 675 676 if (oss) 677 *oss = l->l_sigstk; 678 679 if (nss) { 680 if (nss->ss_flags & ~SS_ALLBITS) 681 error = EINVAL; 682 else if (nss->ss_flags & SS_DISABLE) { 683 if (l->l_sigstk.ss_flags & SS_ONSTACK) 684 error = EINVAL; 685 } else if (nss->ss_size < MINSIGSTKSZ) 686 error = ENOMEM; 687 688 if (!error) 689 l->l_sigstk = *nss; 690 } 691 692 mutex_exit(p->p_lock); 693 694 return error; 695 } 696 697 int 698 sigtimedwait1(struct lwp *l, const struct sys_____sigtimedwait50_args *uap, 699 register_t *retval, copyin_t fetchss, copyout_t storeinf, copyin_t fetchts, 700 copyout_t storets) 701 { 702 /* { 703 syscallarg(const sigset_t *) set; 704 syscallarg(siginfo_t *) info; 705 syscallarg(struct timespec *) timeout; 706 } */ 707 struct proc *p = l->l_proc; 708 int error, signum, timo; 709 struct timespec ts, tsstart, tsnow; 710 ksiginfo_t ksi; 711 712 /* 713 * Calculate timeout, if it was specified. 714 */ 715 if (SCARG(uap, timeout)) { 716 error = (*fetchts)(SCARG(uap, timeout), &ts, sizeof(ts)); 717 if (error) 718 return error; 719 720 if ((error = itimespecfix(&ts)) != 0) 721 return error; 722 723 timo = tstohz(&ts); 724 if (timo == 0 && ts.tv_sec == 0 && ts.tv_nsec != 0) 725 timo++; 726 727 /* 728 * Remember current uptime, it would be used in 729 * ECANCELED/ERESTART case. 730 */ 731 getnanouptime(&tsstart); 732 } else { 733 memset(&tsstart, 0, sizeof(tsstart)); /* XXXgcc */ 734 timo = 0; 735 } 736 737 error = (*fetchss)(SCARG(uap, set), &l->l_sigwaitset, 738 sizeof(l->l_sigwaitset)); 739 if (error) 740 return error; 741 742 /* 743 * Silently ignore SA_CANTMASK signals. psignal1() would ignore 744 * SA_CANTMASK signals in waitset, we do this only for the below 745 * siglist check. 746 */ 747 sigminusset(&sigcantmask, &l->l_sigwaitset); 748 749 mutex_enter(p->p_lock); 750 751 /* Check for pending signals in the process, if no - then in LWP. */ 752 if ((signum = sigget(&p->p_sigpend, &ksi, 0, &l->l_sigwaitset)) == 0) 753 signum = sigget(&l->l_sigpend, &ksi, 0, &l->l_sigwaitset); 754 755 if (signum != 0) { 756 /* If found a pending signal, just copy it out to the user. */ 757 mutex_exit(p->p_lock); 758 goto out; 759 } 760 761 /* 762 * Set up the sigwait list and wait for signal to arrive. 763 * We can either be woken up or time out. 764 */ 765 l->l_sigwaited = &ksi; 766 LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter); 767 error = cv_timedwait_sig(&l->l_sigcv, p->p_lock, timo); 768 769 /* 770 * Need to find out if we woke as a result of _lwp_wakeup() or a 771 * signal outside our wait set. 772 */ 773 if (l->l_sigwaited != NULL) { 774 if (error == EINTR) { 775 /* Wakeup via _lwp_wakeup(). */ 776 error = ECANCELED; 777 } else if (!error) { 778 /* Spurious wakeup - arrange for syscall restart. */ 779 error = ERESTART; 780 } 781 l->l_sigwaited = NULL; 782 LIST_REMOVE(l, l_sigwaiter); 783 } 784 mutex_exit(p->p_lock); 785 786 /* 787 * If the sleep was interrupted (either by signal or wakeup), update 788 * the timeout and copyout new value back. It would be used when 789 * the syscall would be restarted or called again. 790 */ 791 if (timo && (error == ERESTART || error == ECANCELED)) { 792 getnanouptime(&tsnow); 793 794 /* Compute how much time has passed since start. */ 795 timespecsub(&tsnow, &tsstart, &tsnow); 796 797 /* Substract passed time from timeout. */ 798 timespecsub(&ts, &tsnow, &ts); 799 800 if (ts.tv_sec < 0) 801 error = EAGAIN; 802 else { 803 /* Copy updated timeout to userland. */ 804 error = (*storets)(&ts, SCARG(uap, timeout), 805 sizeof(ts)); 806 } 807 } 808 out: 809 /* 810 * If a signal from the wait set arrived, copy it to userland. 811 * Copy only the used part of siginfo, the padding part is 812 * left unchanged (userland is not supposed to touch it anyway). 813 */ 814 if (error == 0 && SCARG(uap, info)) { 815 error = (*storeinf)(&ksi.ksi_info, SCARG(uap, info), 816 sizeof(ksi.ksi_info)); 817 } 818 if (error == 0) 819 *retval = ksi.ksi_info._signo; 820 return error; 821 } 822