sys_sig.c revision 1.13
1 /* $NetBSD: sys_sig.c,v 1.13 2008/04/24 15:35:30 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 2006, 2007 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Copyright (c) 1982, 1986, 1989, 1991, 1993 41 * The Regents of the University of California. All rights reserved. 42 * (c) UNIX System Laboratories, Inc. 43 * All or some portions of this file are derived from material licensed 44 * to the University of California by American Telephone and Telegraph 45 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 46 * the permission of UNIX System Laboratories, Inc. 47 * 48 * Redistribution and use in source and binary forms, with or without 49 * modification, are permitted provided that the following conditions 50 * are met: 51 * 1. Redistributions of source code must retain the above copyright 52 * notice, this list of conditions and the following disclaimer. 53 * 2. Redistributions in binary form must reproduce the above copyright 54 * notice, this list of conditions and the following disclaimer in the 55 * documentation and/or other materials provided with the distribution. 56 * 3. Neither the name of the University nor the names of its contributors 57 * may be used to endorse or promote products derived from this software 58 * without specific prior written permission. 59 * 60 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 61 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 62 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 63 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 64 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 65 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 66 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 67 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 68 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 69 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 70 * SUCH DAMAGE. 71 * 72 * @(#)kern_sig.c 8.14 (Berkeley) 5/14/95 73 */ 74 75 #include <sys/cdefs.h> 76 __KERNEL_RCSID(0, "$NetBSD: sys_sig.c,v 1.13 2008/04/24 15:35:30 ad Exp $"); 77 78 #include "opt_ptrace.h" 79 #include "opt_compat_netbsd.h" 80 #include "opt_compat_netbsd32.h" 81 82 #include <sys/param.h> 83 #include <sys/kernel.h> 84 #include <sys/signalvar.h> 85 #include <sys/proc.h> 86 #include <sys/pool.h> 87 #include <sys/syscallargs.h> 88 #include <sys/kauth.h> 89 #include <sys/wait.h> 90 #include <sys/kmem.h> 91 92 #ifdef COMPAT_16 93 /* ARGSUSED */ 94 int 95 compat_16_sys___sigaction14(struct lwp *l, const struct compat_16_sys___sigaction14_args *uap, register_t *retval) 96 { 97 /* { 98 syscallarg(int) signum; 99 syscallarg(const struct sigaction *) nsa; 100 syscallarg(struct sigaction *) osa; 101 } */ 102 struct sigaction nsa, osa; 103 int error; 104 105 if (SCARG(uap, nsa)) { 106 error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa)); 107 if (error) 108 return (error); 109 } 110 error = sigaction1(l, SCARG(uap, signum), 111 SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0, 112 NULL, 0); 113 if (error) 114 return (error); 115 if (SCARG(uap, osa)) { 116 error = copyout(&osa, SCARG(uap, osa), sizeof(osa)); 117 if (error) 118 return (error); 119 } 120 return (0); 121 } 122 #endif 123 124 /* ARGSUSED */ 125 int 126 sys___sigaction_sigtramp(struct lwp *l, const struct sys___sigaction_sigtramp_args *uap, register_t *retval) 127 { 128 /* { 129 syscallarg(int) signum; 130 syscallarg(const struct sigaction *) nsa; 131 syscallarg(struct sigaction *) osa; 132 syscallarg(void *) tramp; 133 syscallarg(int) vers; 134 } */ 135 struct sigaction nsa, osa; 136 int error; 137 138 if (SCARG(uap, nsa)) { 139 error = copyin(SCARG(uap, nsa), &nsa, sizeof(nsa)); 140 if (error) 141 return (error); 142 } 143 error = sigaction1(l, SCARG(uap, signum), 144 SCARG(uap, nsa) ? &nsa : 0, SCARG(uap, osa) ? &osa : 0, 145 SCARG(uap, tramp), SCARG(uap, vers)); 146 if (error) 147 return (error); 148 if (SCARG(uap, osa)) { 149 error = copyout(&osa, SCARG(uap, osa), sizeof(osa)); 150 if (error) 151 return (error); 152 } 153 return (0); 154 } 155 156 /* 157 * Manipulate signal mask. Note that we receive new mask, not pointer, and 158 * return old mask as return value; the library stub does the rest. 159 */ 160 int 161 sys___sigprocmask14(struct lwp *l, const struct sys___sigprocmask14_args *uap, register_t *retval) 162 { 163 /* { 164 syscallarg(int) how; 165 syscallarg(const sigset_t *) set; 166 syscallarg(sigset_t *) oset; 167 } */ 168 struct proc *p = l->l_proc; 169 sigset_t nss, oss; 170 int error; 171 172 if (SCARG(uap, set)) { 173 error = copyin(SCARG(uap, set), &nss, sizeof(nss)); 174 if (error) 175 return (error); 176 } 177 mutex_enter(&p->p_smutex); 178 error = sigprocmask1(l, SCARG(uap, how), 179 SCARG(uap, set) ? &nss : 0, SCARG(uap, oset) ? &oss : 0); 180 mutex_exit(&p->p_smutex); 181 if (error) 182 return (error); 183 if (SCARG(uap, oset)) { 184 error = copyout(&oss, SCARG(uap, oset), sizeof(oss)); 185 if (error) 186 return (error); 187 } 188 return (0); 189 } 190 191 /* ARGSUSED */ 192 int 193 sys___sigpending14(struct lwp *l, const struct sys___sigpending14_args *uap, register_t *retval) 194 { 195 /* { 196 syscallarg(sigset_t *) set; 197 } */ 198 sigset_t ss; 199 200 sigpending1(l, &ss); 201 return (copyout(&ss, SCARG(uap, set), sizeof(ss))); 202 } 203 204 /* 205 * Suspend process until signal, providing mask to be set in the meantime. 206 * Note nonstandard calling convention: libc stub passes mask, not pointer, 207 * to save a copyin. 208 */ 209 /* ARGSUSED */ 210 int 211 sys___sigsuspend14(struct lwp *l, const struct sys___sigsuspend14_args *uap, register_t *retval) 212 { 213 /* { 214 syscallarg(const sigset_t *) set; 215 } */ 216 sigset_t ss; 217 int error; 218 219 if (SCARG(uap, set)) { 220 error = copyin(SCARG(uap, set), &ss, sizeof(ss)); 221 if (error) 222 return (error); 223 } 224 225 return (sigsuspend1(l, SCARG(uap, set) ? &ss : 0)); 226 } 227 228 /* ARGSUSED */ 229 int 230 sys___sigaltstack14(struct lwp *l, const struct sys___sigaltstack14_args *uap, register_t *retval) 231 { 232 /* { 233 syscallarg(const struct sigaltstack *) nss; 234 syscallarg(struct sigaltstack *) oss; 235 } */ 236 struct sigaltstack nss, oss; 237 int error; 238 239 if (SCARG(uap, nss)) { 240 error = copyin(SCARG(uap, nss), &nss, sizeof(nss)); 241 if (error) 242 return (error); 243 } 244 error = sigaltstack1(l, 245 SCARG(uap, nss) ? &nss : 0, SCARG(uap, oss) ? &oss : 0); 246 if (error) 247 return (error); 248 if (SCARG(uap, oss)) { 249 error = copyout(&oss, SCARG(uap, oss), sizeof(oss)); 250 if (error) 251 return (error); 252 } 253 return (0); 254 } 255 256 /* ARGSUSED */ 257 int 258 sys_kill(struct lwp *l, const struct sys_kill_args *uap, register_t *retval) 259 { 260 /* { 261 syscallarg(int) pid; 262 syscallarg(int) signum; 263 } */ 264 struct proc *p; 265 ksiginfo_t ksi; 266 int signum = SCARG(uap, signum); 267 int error; 268 269 if ((u_int)signum >= NSIG) 270 return (EINVAL); 271 KSI_INIT(&ksi); 272 ksi.ksi_signo = signum; 273 ksi.ksi_code = SI_USER; 274 ksi.ksi_pid = l->l_proc->p_pid; 275 ksi.ksi_uid = kauth_cred_geteuid(l->l_cred); 276 if (SCARG(uap, pid) > 0) { 277 /* kill single process */ 278 mutex_enter(proc_lock); 279 if ((p = p_find(SCARG(uap, pid), PFIND_LOCKED)) == NULL) { 280 mutex_exit(proc_lock); 281 return (ESRCH); 282 } 283 mutex_enter(&p->p_mutex); 284 error = kauth_authorize_process(l->l_cred, 285 KAUTH_PROCESS_SIGNAL, p, KAUTH_ARG(signum), 286 NULL, NULL); 287 if (!error && signum) { 288 mutex_enter(&p->p_smutex); 289 kpsignal2(p, &ksi); 290 mutex_exit(&p->p_smutex); 291 } 292 mutex_exit(&p->p_mutex); 293 mutex_exit(proc_lock); 294 return (error); 295 } 296 switch (SCARG(uap, pid)) { 297 case -1: /* broadcast signal */ 298 return (killpg1(l, &ksi, 0, 1)); 299 case 0: /* signal own process group */ 300 return (killpg1(l, &ksi, 0, 0)); 301 default: /* negative explicit process group */ 302 return (killpg1(l, &ksi, -SCARG(uap, pid), 0)); 303 } 304 /* NOTREACHED */ 305 } 306 307 /* ARGSUSED */ 308 int 309 sys_getcontext(struct lwp *l, const struct sys_getcontext_args *uap, register_t *retval) 310 { 311 /* { 312 syscallarg(struct __ucontext *) ucp; 313 } */ 314 struct proc *p = l->l_proc; 315 ucontext_t uc; 316 317 mutex_enter(&p->p_smutex); 318 getucontext(l, &uc); 319 mutex_exit(&p->p_smutex); 320 321 return (copyout(&uc, SCARG(uap, ucp), sizeof (*SCARG(uap, ucp)))); 322 } 323 324 /* ARGSUSED */ 325 int 326 sys_setcontext(struct lwp *l, const struct sys_setcontext_args *uap, register_t *retval) 327 { 328 /* { 329 syscallarg(const ucontext_t *) ucp; 330 } */ 331 struct proc *p = l->l_proc; 332 ucontext_t uc; 333 int error; 334 335 error = copyin(SCARG(uap, ucp), &uc, sizeof (uc)); 336 if (error) 337 return (error); 338 if (!(uc.uc_flags & _UC_CPU)) 339 return (EINVAL); 340 mutex_enter(&p->p_smutex); 341 error = setucontext(l, &uc); 342 mutex_exit(&p->p_smutex); 343 if (error) 344 return (error); 345 346 return (EJUSTRETURN); 347 } 348 349 /* 350 * sigtimedwait(2) system call, used also for implementation 351 * of sigwaitinfo() and sigwait(). 352 * 353 * This only handles single LWP in signal wait. libpthread provides 354 * it's own sigtimedwait() wrapper to DTRT WRT individual threads. 355 */ 356 int 357 sys___sigtimedwait(struct lwp *l, const struct sys___sigtimedwait_args *uap, register_t *retval) 358 { 359 360 return __sigtimedwait1(l, uap, retval, copyout, copyin, copyout); 361 } 362 363 int 364 sigaction1(struct lwp *l, int signum, const struct sigaction *nsa, 365 struct sigaction *osa, const void *tramp, int vers) 366 { 367 struct proc *p; 368 struct sigacts *ps; 369 sigset_t tset; 370 int prop, error; 371 ksiginfoq_t kq; 372 373 if (signum <= 0 || signum >= NSIG) 374 return (EINVAL); 375 376 p = l->l_proc; 377 error = 0; 378 ksiginfo_queue_init(&kq); 379 380 /* 381 * Trampoline ABI version 0 is reserved for the legacy kernel 382 * provided on-stack trampoline. Conversely, if we are using a 383 * non-0 ABI version, we must have a trampoline. Only validate the 384 * vers if a new sigaction was supplied. Emulations use legacy 385 * kernel trampolines with version 0, alternatively check for that 386 * too. 387 */ 388 if ((vers != 0 && tramp == NULL) || 389 #ifdef SIGTRAMP_VALID 390 (nsa != NULL && 391 ((vers == 0) ? 392 (p->p_emul->e_sigcode == NULL) : 393 !SIGTRAMP_VALID(vers))) || 394 #endif 395 (vers == 0 && tramp != NULL)) { 396 return (EINVAL); 397 } 398 399 mutex_enter(&p->p_mutex); /* p_flag */ 400 mutex_enter(&p->p_smutex); 401 402 ps = p->p_sigacts; 403 if (osa) 404 *osa = SIGACTION_PS(ps, signum); 405 if (!nsa) 406 goto out; 407 408 prop = sigprop[signum]; 409 if ((nsa->sa_flags & ~SA_ALLBITS) || (prop & SA_CANTMASK)) { 410 error = EINVAL; 411 goto out; 412 } 413 414 SIGACTION_PS(ps, signum) = *nsa; 415 ps->sa_sigdesc[signum].sd_tramp = tramp; 416 ps->sa_sigdesc[signum].sd_vers = vers; 417 sigminusset(&sigcantmask, &SIGACTION_PS(ps, signum).sa_mask); 418 419 if ((prop & SA_NORESET) != 0) 420 SIGACTION_PS(ps, signum).sa_flags &= ~SA_RESETHAND; 421 422 if (signum == SIGCHLD) { 423 if (nsa->sa_flags & SA_NOCLDSTOP) 424 p->p_sflag |= PS_NOCLDSTOP; 425 else 426 p->p_sflag &= ~PS_NOCLDSTOP; 427 if (nsa->sa_flags & SA_NOCLDWAIT) { 428 /* 429 * Paranoia: since SA_NOCLDWAIT is implemented by 430 * reparenting the dying child to PID 1 (and trust 431 * it to reap the zombie), PID 1 itself is forbidden 432 * to set SA_NOCLDWAIT. 433 */ 434 if (p->p_pid == 1) 435 p->p_flag &= ~PK_NOCLDWAIT; 436 else 437 p->p_flag |= PK_NOCLDWAIT; 438 } else 439 p->p_flag &= ~PK_NOCLDWAIT; 440 441 if (nsa->sa_handler == SIG_IGN) { 442 /* 443 * Paranoia: same as above. 444 */ 445 if (p->p_pid == 1) 446 p->p_flag &= ~PK_CLDSIGIGN; 447 else 448 p->p_flag |= PK_CLDSIGIGN; 449 } else 450 p->p_flag &= ~PK_CLDSIGIGN; 451 } 452 453 if ((nsa->sa_flags & SA_NODEFER) == 0) 454 sigaddset(&SIGACTION_PS(ps, signum).sa_mask, signum); 455 else 456 sigdelset(&SIGACTION_PS(ps, signum).sa_mask, signum); 457 458 /* 459 * Set bit in p_sigctx.ps_sigignore for signals that are set to 460 * SIG_IGN, and for signals set to SIG_DFL where the default is to 461 * ignore. However, don't put SIGCONT in p_sigctx.ps_sigignore, as 462 * we have to restart the process. 463 */ 464 if (nsa->sa_handler == SIG_IGN || 465 (nsa->sa_handler == SIG_DFL && (prop & SA_IGNORE) != 0)) { 466 /* Never to be seen again. */ 467 sigemptyset(&tset); 468 sigaddset(&tset, signum); 469 sigclearall(p, &tset, &kq); 470 if (signum != SIGCONT) { 471 /* Easier in psignal */ 472 sigaddset(&p->p_sigctx.ps_sigignore, signum); 473 } 474 sigdelset(&p->p_sigctx.ps_sigcatch, signum); 475 } else { 476 sigdelset(&p->p_sigctx.ps_sigignore, signum); 477 if (nsa->sa_handler == SIG_DFL) 478 sigdelset(&p->p_sigctx.ps_sigcatch, signum); 479 else 480 sigaddset(&p->p_sigctx.ps_sigcatch, signum); 481 } 482 483 /* 484 * Previously held signals may now have become visible. Ensure that 485 * we check for them before returning to userspace. 486 */ 487 if (sigispending(l, 0)) { 488 lwp_lock(l); 489 l->l_flag |= LW_PENDSIG; 490 lwp_unlock(l); 491 } 492 out: 493 mutex_exit(&p->p_smutex); 494 mutex_exit(&p->p_mutex); 495 ksiginfo_queue_drain(&kq); 496 497 return (error); 498 } 499 500 int 501 sigprocmask1(struct lwp *l, int how, const sigset_t *nss, sigset_t *oss) 502 { 503 int more; 504 505 KASSERT(mutex_owned(&l->l_proc->p_smutex)); 506 507 if (oss) 508 *oss = l->l_sigmask; 509 if (nss) { 510 switch (how) { 511 case SIG_BLOCK: 512 sigplusset(nss, &l->l_sigmask); 513 more = 0; 514 break; 515 case SIG_UNBLOCK: 516 sigminusset(nss, &l->l_sigmask); 517 more = 1; 518 break; 519 case SIG_SETMASK: 520 l->l_sigmask = *nss; 521 more = 1; 522 break; 523 default: 524 return (EINVAL); 525 } 526 sigminusset(&sigcantmask, &l->l_sigmask); 527 if (more && sigispending(l, 0)) { 528 /* 529 * Check for pending signals on return to user. 530 */ 531 lwp_lock(l); 532 l->l_flag |= LW_PENDSIG; 533 lwp_unlock(l); 534 } 535 } 536 537 return (0); 538 } 539 540 void 541 sigpending1(struct lwp *l, sigset_t *ss) 542 { 543 struct proc *p = l->l_proc; 544 545 mutex_enter(&p->p_smutex); 546 *ss = l->l_sigpend.sp_set; 547 sigplusset(&p->p_sigpend.sp_set, ss); 548 sigminusset(&l->l_sigmask, ss); 549 mutex_exit(&p->p_smutex); 550 } 551 552 int 553 sigsuspend1(struct lwp *l, const sigset_t *ss) 554 { 555 struct proc *p; 556 557 p = l->l_proc; 558 559 if (ss) { 560 /* 561 * When returning from sigsuspend, we want 562 * the old mask to be restored after the 563 * signal handler has finished. Thus, we 564 * save it here and mark the sigctx structure 565 * to indicate this. 566 */ 567 mutex_enter(&p->p_smutex); 568 l->l_sigrestore = 1; 569 l->l_sigoldmask = l->l_sigmask; 570 l->l_sigmask = *ss; 571 sigminusset(&sigcantmask, &l->l_sigmask); 572 573 /* Check for pending signals when sleeping. */ 574 if (sigispending(l, 0)) { 575 lwp_lock(l); 576 l->l_flag |= LW_PENDSIG; 577 lwp_unlock(l); 578 } 579 mutex_exit(&p->p_smutex); 580 } 581 582 while (kpause("pause", true, 0, NULL) == 0) 583 ; 584 585 /* always return EINTR rather than ERESTART... */ 586 return (EINTR); 587 } 588 589 int 590 sigaltstack1(struct lwp *l, const struct sigaltstack *nss, 591 struct sigaltstack *oss) 592 { 593 struct proc *p = l->l_proc; 594 int error = 0; 595 596 mutex_enter(&p->p_smutex); 597 598 if (oss) 599 *oss = l->l_sigstk; 600 601 if (nss) { 602 if (nss->ss_flags & ~SS_ALLBITS) 603 error = EINVAL; 604 else if (nss->ss_flags & SS_DISABLE) { 605 if (l->l_sigstk.ss_flags & SS_ONSTACK) 606 error = EINVAL; 607 } else if (nss->ss_size < MINSIGSTKSZ) 608 error = ENOMEM; 609 610 if (!error) 611 l->l_sigstk = *nss; 612 } 613 614 mutex_exit(&p->p_smutex); 615 616 return (error); 617 } 618 619 int 620 __sigtimedwait1(struct lwp *l, const struct sys___sigtimedwait_args *uap, register_t *retval, 621 copyout_t put_info, copyin_t fetch_timeout, copyout_t put_timeout) 622 { 623 /* { 624 syscallarg(const sigset_t *) set; 625 syscallarg(siginfo_t *) info; 626 syscallarg(struct timespec *) timeout; 627 } */ 628 struct proc *p = l->l_proc; 629 int error, signum; 630 int timo = 0; 631 struct timespec ts, tsstart, tsnow; 632 ksiginfo_t *ksi; 633 634 memset(&tsstart, 0, sizeof tsstart); /* XXX gcc */ 635 636 /* 637 * Calculate timeout, if it was specified. 638 */ 639 if (SCARG(uap, timeout)) { 640 uint64_t ms; 641 642 if ((error = (*fetch_timeout)(SCARG(uap, timeout), &ts, sizeof(ts)))) 643 return (error); 644 645 ms = (ts.tv_sec * 1000) + (ts.tv_nsec / 1000000); 646 timo = mstohz(ms); 647 if (timo == 0 && ts.tv_sec == 0 && ts.tv_nsec > 0) 648 timo = 1; 649 if (timo <= 0) 650 return (EAGAIN); 651 652 /* 653 * Remember current uptime, it would be used in 654 * ECANCELED/ERESTART case. 655 */ 656 getnanouptime(&tsstart); 657 } 658 659 error = copyin(SCARG(uap, set), &l->l_sigwaitset, 660 sizeof(l->l_sigwaitset)); 661 if (error != 0) 662 return (error); 663 664 /* 665 * Silently ignore SA_CANTMASK signals. psignal1() would ignore 666 * SA_CANTMASK signals in waitset, we do this only for the below 667 * siglist check. 668 */ 669 sigminusset(&sigcantmask, &l->l_sigwaitset); 670 671 /* 672 * Allocate a ksi up front. We can't sleep with the mutex held. 673 */ 674 ksi = ksiginfo_alloc(p, NULL, PR_WAITOK); 675 if (ksi == NULL) 676 return (ENOMEM); 677 678 mutex_enter(&p->p_smutex); 679 680 if ((signum = sigget(&p->p_sigpend, ksi, 0, &l->l_sigwaitset)) == 0) 681 signum = sigget(&l->l_sigpend, ksi, 0, &l->l_sigwaitset); 682 683 if (signum != 0) { 684 /* 685 * We found a pending signal - copy it out to the user. 686 */ 687 mutex_exit(&p->p_smutex); 688 goto out; 689 } 690 691 /* 692 * Set up the sigwait list. 693 */ 694 l->l_sigwaited = ksi; 695 LIST_INSERT_HEAD(&p->p_sigwaiters, l, l_sigwaiter); 696 697 /* 698 * Wait for signal to arrive. We can either be woken up or time out. 699 */ 700 error = cv_timedwait_sig(&l->l_sigcv, &p->p_smutex, timo); 701 702 /* 703 * Need to find out if we woke as a result of lwp_wakeup() or a 704 * signal outside our wait set. 705 */ 706 if (l->l_sigwaited != NULL) { 707 if (error == EINTR) { 708 /* wakeup via _lwp_wakeup() */ 709 error = ECANCELED; 710 } else if (!error) { 711 /* spurious wakeup - arrange for syscall restart */ 712 error = ERESTART; 713 } 714 l->l_sigwaited = NULL; 715 LIST_REMOVE(l, l_sigwaiter); 716 } 717 718 mutex_exit(&p->p_smutex); 719 720 /* 721 * If the sleep was interrupted (either by signal or wakeup), update 722 * the timeout and copyout new value back. It would be used when 723 * the syscall would be restarted or called again. 724 */ 725 if (timo && (error == ERESTART || error == ECANCELED)) { 726 getnanouptime(&tsnow); 727 728 /* compute how much time has passed since start */ 729 timespecsub(&tsnow, &tsstart, &tsnow); 730 /* substract passed time from timeout */ 731 timespecsub(&ts, &tsnow, &ts); 732 733 if (ts.tv_sec < 0) 734 error = EAGAIN; 735 else { 736 /* copy updated timeout to userland */ 737 error = (*put_timeout)(&ts, SCARG(uap, timeout), 738 sizeof(ts)); 739 } 740 } 741 742 /* 743 * If a signal from the wait set arrived, copy it to userland. 744 * Copy only the used part of siginfo, the padding part is 745 * left unchanged (userland is not supposed to touch it anyway). 746 */ 747 out: 748 if (error == 0) 749 error = (*put_info)(&ksi->ksi_info, SCARG(uap, info), 750 sizeof(ksi->ksi_info)); 751 752 ksiginfo_free(ksi); 753 754 return error; 755 } 756
Indexes created Mon Sep 22 13:09:51 GMT 2025