1 /* $NetBSD: sys_sig.c,v 1.31 2011/02/03 21:45:32 joerg 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 1.31 2011/02/03 21:45:32 joerg 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/sa.h> 77 #include <sys/savar.h> 78 #include <sys/syscallargs.h> 79 #include <sys/kauth.h> 80 #include <sys/wait.h> 81 #include <sys/kmem.h> 82 #include <sys/module.h> 83 84 int 85 sys___sigaction_sigtramp(struct lwp *l, 86 const struct sys___sigaction_sigtramp_args *uap, register_t *retval) 87 { 88 /* { 89 syscallarg(int) signum; 90 syscallarg(const struct sigaction *) nsa; 91 syscallarg(struct sigaction *) osa; 92 syscallarg(void *) tramp; 93 syscallarg(int) vers; 94 } */ 95 struct sigaction nsa, osa; 96 int error; 97 98 if (SCARG(uap, nsa)) { 99 error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa)); 100 if (error) 101 return (error); 102 } 103 error = sigaction1(l, SCARG(uap, signum), 104 SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0, 105 SCARG(uap, tramp), SCARG(uap, vers)); 106 if (error) 107 return (error); 108 if (SCARG(uap, osa)) { 109 error = copyout(&osa, SCARG(uap, osa), sizeof(osa)); 110 if (error) 111 return (error); 112 } 113 return 0; 114 } 115 116 /* 117 * Manipulate signal mask. Note that we receive new mask, not pointer, and 118 * return old mask as return value; the library stub does the rest. 119 */ 120 int 121 sys___sigprocmask14(struct lwp *l, const struct sys___sigprocmask14_args *uap, 122 register_t *retval) 123 { 124 /* { 125 syscallarg(int) how; 126 syscallarg(const sigset_t *) set; 127 syscallarg(sigset_t *) oset; 128 } */ 129 struct proc *p = l->l_proc; 130 sigset_t nss, oss; 131 int error; 132 133 if (SCARG(uap, set)) { 134 error = copyin(SCARG(uap, set), &nss, sizeof(nss)); 135 if (error) 136 return error; 137 } 138 mutex_enter(p->p_lock); 139 error = sigprocmask1(l, SCARG(uap, how), 140 SCARG(uap, set) ? &nss : 0, SCARG(uap, oset) ? &oss : 0); 141 mutex_exit(p->p_lock); 142 if (error) 143 return error; 144 if (SCARG(uap, oset)) { 145 error = copyout(&oss, SCARG(uap, oset), sizeof(oss)); 146 if (error) 147 return error; 148 } 149 return 0; 150 } 151 152 int 153 sys___sigpending14(struct lwp *l, const struct sys___sigpending14_args *uap, 154 register_t *retval) 155 { 156 /* { 157 syscallarg(sigset_t *) set; 158 } */ 159 sigset_t ss; 160 161 sigpending1(l, &ss); 162 return copyout(&ss, SCARG(uap, set), sizeof(ss)); 163 } 164 165 /* 166 * Suspend process until signal, providing mask to be set in the meantime. 167 * Note nonstandard calling convention: libc stub passes mask, not pointer, 168 * to save a copyin. 169 */ 170 int 171 sys___sigsuspend14(struct lwp *l, const struct sys___sigsuspend14_args *uap, 172 register_t *retval) 173 { 174 /* { 175 syscallarg(const sigset_t *) set; 176 } */ 177 sigset_t ss; 178 int error; 179 180 if (SCARG(uap, set)) { 181 error = copyin(SCARG(uap, set), &ss, sizeof(ss)); 182 if (error) 183 return error; 184 } 185 return sigsuspend1(l, SCARG(uap, set) ? &ss : 0); 186 } 187 188 int 189 sys___sigaltstack14(struct lwp *l, const struct sys___sigaltstack14_args *uap, 190 register_t *retval) 191 { 192 /* { 193 syscallarg(const struct sigaltstack *) nss; 194 syscallarg(struct sigaltstack *) oss; 195 } */ 196 struct sigaltstack nss, oss; 197 int error; 198 199 if (SCARG(uap, nss)) { 200 error = copyin(SCARG(uap, nss), &nss, sizeof(nss)); 201 if (error) 202 return error; 203 } 204 error = sigaltstack1(l, 205 SCARG(uap, nss) ? &nss : 0, SCARG(uap, oss) ? &oss : 0); 206 if (error) 207 return error; 208 if (SCARG(uap, oss)) { 209 error = copyout(&oss, SCARG(uap, oss), sizeof(oss)); 210 if (error) 211 return error; 212 } 213 return 0; 214 } 215 216 217 static int 218 kill1(struct lwp *l, pid_t pid, ksiginfo_t *ksi, register_t *retval) 219 { 220 int error; 221 struct proc *p; 222 223 if ((u_int)ksi->ksi_signo >= NSIG) 224 return EINVAL; 225 226 if (ksi->ksi_pid != l->l_proc->p_pid) 227 return EPERM; 228 229 if (ksi->ksi_uid != kauth_cred_geteuid(l->l_cred)) 230 return EPERM; 231 232 switch (ksi->ksi_code) { 233 case SI_USER: 234 case SI_QUEUE: 235 break; 236 default: 237 return EPERM; 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, 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 int more; 555 struct proc *p = l->l_proc; 556 sigset_t *mask; 557 mask = (p->p_sa != NULL) ? &p->p_sa->sa_sigmask : &l->l_sigmask; 558 559 KASSERT(mutex_owned(p->p_lock)); 560 561 if (oss) 562 *oss = *mask; 563 if (nss) { 564 switch (how) { 565 case SIG_BLOCK: 566 sigplusset(nss, mask); 567 more = 0; 568 break; 569 case SIG_UNBLOCK: 570 sigminusset(nss, mask); 571 more = 1; 572 break; 573 case SIG_SETMASK: 574 *mask = *nss; 575 more = 1; 576 break; 577 default: 578 return (EINVAL); 579 } 580 sigminusset(&sigcantmask, mask); 581 if (more && sigispending(l, 0)) { 582 /* 583 * Check for pending signals on return to user. 584 */ 585 lwp_lock(l); 586 l->l_flag |= LW_PENDSIG; 587 lwp_unlock(l); 588 } 589 } 590 591 return 0; 592 } 593 594 void 595 sigpending1(struct lwp *l, sigset_t *ss) 596 { 597 struct proc *p = l->l_proc; 598 599 mutex_enter(p->p_lock); 600 *ss = l->l_sigpend.sp_set; 601 sigplusset(&p->p_sigpend.sp_set, ss); 602 mutex_exit(p->p_lock); 603 } 604 605 int 606 sigsuspend1(struct lwp *l, const sigset_t *ss) 607 { 608 struct proc *p = l->l_proc; 609 610 if (ss) { 611 /* 612 * When returning from sigsuspend, 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 while (kpause("pause", true, 0, NULL) == 0) 634 ; 635 636 /* always return EINTR rather than ERESTART... */ 637 return EINTR; 638 } 639 640 int 641 sigaltstack1(struct lwp *l, const struct sigaltstack *nss, 642 struct sigaltstack *oss) 643 { 644 struct proc *p = l->l_proc; 645 int error = 0; 646 647 mutex_enter(p->p_lock); 648 649 if (oss) 650 *oss = l->l_sigstk; 651 652 if (nss) { 653 if (nss->ss_flags & ~SS_ALLBITS) 654 error = EINVAL; 655 else if (nss->ss_flags & SS_DISABLE) { 656 if (l->l_sigstk.ss_flags & SS_ONSTACK) 657 error = EINVAL; 658 } else if (nss->ss_size < MINSIGSTKSZ) 659 error = ENOMEM; 660 661 if (!error) 662 l->l_sigstk = *nss; 663 } 664 665 mutex_exit(p->p_lock); 666 667 return error; 668 } 669 670 int 671 sigtimedwait1(struct lwp *l, const struct sys_____sigtimedwait50_args *uap, 672 register_t *retval, copyout_t storeinf, copyin_t fetchts, copyout_t storets) 673 { 674 /* { 675 syscallarg(const sigset_t *) set; 676 syscallarg(siginfo_t *) info; 677 syscallarg(struct timespec *) timeout; 678 } */ 679 struct proc *p = l->l_proc; 680 int error, signum, timo; 681 struct timespec ts, tsstart, tsnow; 682 ksiginfo_t ksi; 683 684 /* 685 * Calculate timeout, if it was specified. 686 */ 687 if (SCARG(uap, timeout)) { 688 error = (*fetchts)(SCARG(uap, timeout), &ts, sizeof(ts)); 689 if (error) 690 return error; 691 692 if ((error = itimespecfix(&ts)) != 0) 693 return error; 694 695 timo = tstohz(&ts); 696 if (timo == 0 && ts.tv_sec == 0 && ts.tv_nsec != 0) 697 timo++; 698 699 /* 700 * Remember current uptime, it would be used in 701 * ECANCELED/ERESTART case. 702 */ 703 getnanouptime(&tsstart); 704 } else { 705 memset(&tsstart, 0, sizeof(tsstart)); /* XXXgcc */ 706 timo = 0; 707 } 708 709 error = copyin(SCARG(uap, set), &l->l_sigwaitset, 710 sizeof(l->l_sigwaitset)); 711 if (error) 712 return error; 713 714 /* 715 * Silently ignore SA_CANTMASK signals. psignal1() would ignore 716 * SA_CANTMASK signals in waitset, we do this only for the below 717 * siglist check. 718 */ 719 sigminusset(&sigcantmask, &l->l_sigwaitset); 720 721 mutex_enter(p->p_lock); 722 723 /* SA processes can have no more than 1 sigwaiter. */ 724 if ((p->p_sflag & PS_SA) != 0 && !LIST_EMPTY(&p->p_sigwaiters)) { 725 mutex_exit(p->p_lock); 726 error = EINVAL; 727 goto out; 728 } 729 730 /* Check for pending signals in the process, if no - then in LWP. */ 731 if ((signum = sigget(&p->p_sigpend, &ksi, 0, &l->l_sigwaitset)) == 0) 732 signum = sigget(&l->l_sigpend, &ksi, 0, &l->l_sigwaitset); 733 734 if (signum != 0) { 735 /* If found a pending signal, just copy it out to the user. */ 736 mutex_exit(p->p_lock); 737 goto out; 738 } 739 740 /* 741 * Set up the sigwait list and wait for signal to arrive. 742 * We can either be woken up or time out. 743 */ 744 l->l_sigwaited = &ksi; 745 LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter); 746 error = cv_timedwait_sig(&l->l_sigcv, p->p_lock, timo); 747 748 /* 749 * Need to find out if we woke as a result of _lwp_wakeup() or a 750 * signal outside our wait set. 751 */ 752 if (l->l_sigwaited != NULL) { 753 if (error == EINTR) { 754 /* Wakeup via _lwp_wakeup(). */ 755 error = ECANCELED; 756 } else if (!error) { 757 /* Spurious wakeup - arrange for syscall restart. */ 758 error = ERESTART; 759 } 760 l->l_sigwaited = NULL; 761 LIST_REMOVE(l, l_sigwaiter); 762 } 763 mutex_exit(p->p_lock); 764 765 /* 766 * If the sleep was interrupted (either by signal or wakeup), update 767 * the timeout and copyout new value back. It would be used when 768 * the syscall would be restarted or called again. 769 */ 770 if (timo && (error == ERESTART || error == ECANCELED)) { 771 getnanouptime(&tsnow); 772 773 /* Compute how much time has passed since start. */ 774 timespecsub(&tsnow, &tsstart, &tsnow); 775 776 /* Substract passed time from timeout. */ 777 timespecsub(&ts, &tsnow, &ts); 778 779 if (ts.tv_sec < 0) 780 error = EAGAIN; 781 else { 782 /* Copy updated timeout to userland. */ 783 error = (*storets)(&ts, SCARG(uap, timeout), 784 sizeof(ts)); 785 } 786 } 787 out: 788 /* 789 * If a signal from the wait set arrived, copy it to userland. 790 * Copy only the used part of siginfo, the padding part is 791 * left unchanged (userland is not supposed to touch it anyway). 792 */ 793 if (error == 0 && SCARG(uap, info)) { 794 error = (*storeinf)(&ksi.ksi_info, SCARG(uap, info), 795 sizeof(ksi.ksi_info)); 796 } 797 if (error == 0) 798 *retval = ksi.ksi_info._signo; 799 return error; 800 } 801