1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 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 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 #include "opt_core.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/signalvar.h> 47 #include <sys/vnode.h> 48 #include <sys/acct.h> 49 #include <sys/capsicum.h> 50 #include <sys/condvar.h> 51 #include <sys/event.h> 52 #include <sys/fcntl.h> 53 #include <sys/imgact.h> 54 #include <sys/kernel.h> 55 #include <sys/ktr.h> 56 #include <sys/ktrace.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mutex.h> 60 #include <sys/refcount.h> 61 #include <sys/namei.h> 62 #include <sys/proc.h> 63 #include <sys/procdesc.h> 64 #include <sys/posix4.h> 65 #include <sys/pioctl.h> 66 #include <sys/racct.h> 67 #include <sys/resourcevar.h> 68 #include <sys/sdt.h> 69 #include <sys/sbuf.h> 70 #include <sys/sleepqueue.h> 71 #include <sys/smp.h> 72 #include <sys/stat.h> 73 #include <sys/sx.h> 74 #include <sys/syscallsubr.h> 75 #include <sys/sysctl.h> 76 #include <sys/sysent.h> 77 #include <sys/syslog.h> 78 #include <sys/sysproto.h> 79 #include <sys/timers.h> 80 #include <sys/unistd.h> 81 #include <sys/wait.h> 82 #include <vm/vm.h> 83 #include <vm/vm_extern.h> 84 #include <vm/uma.h> 85 86 #include <sys/jail.h> 87 88 #include <machine/cpu.h> 89 90 #include <security/audit/audit.h> 91 92 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 93 94 SDT_PROVIDER_DECLARE(proc); 95 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *", 96 "struct proc *", "int"); 97 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int", 98 "ksiginfo_t *"); 99 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard, 100 "struct thread *", "struct proc *", "int"); 101 102 static int coredump(struct thread *); 103 static int killpg1(struct thread *td, int sig, int pgid, int all, 104 ksiginfo_t *ksi); 105 static int issignal(struct thread *td); 106 static int sigprop(int sig); 107 static void tdsigwakeup(struct thread *, int, sig_t, int); 108 static void sig_suspend_threads(struct thread *, struct proc *, int); 109 static int filt_sigattach(struct knote *kn); 110 static void filt_sigdetach(struct knote *kn); 111 static int filt_signal(struct knote *kn, long hint); 112 static struct thread *sigtd(struct proc *p, int sig, int prop); 113 static void sigqueue_start(void); 114 115 static uma_zone_t ksiginfo_zone = NULL; 116 struct filterops sig_filtops = { 117 .f_isfd = 0, 118 .f_attach = filt_sigattach, 119 .f_detach = filt_sigdetach, 120 .f_event = filt_signal, 121 }; 122 123 static int kern_logsigexit = 1; 124 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 125 &kern_logsigexit, 0, 126 "Log processes quitting on abnormal signals to syslog(3)"); 127 128 static int kern_forcesigexit = 1; 129 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 130 &kern_forcesigexit, 0, "Force trap signal to be handled"); 131 132 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 133 "POSIX real time signal"); 134 135 static int max_pending_per_proc = 128; 136 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 137 &max_pending_per_proc, 0, "Max pending signals per proc"); 138 139 static int preallocate_siginfo = 1024; 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 141 &preallocate_siginfo, 0, "Preallocated signal memory size"); 142 143 static int signal_overflow = 0; 144 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 145 &signal_overflow, 0, "Number of signals overflew"); 146 147 static int signal_alloc_fail = 0; 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 149 &signal_alloc_fail, 0, "signals failed to be allocated"); 150 151 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 152 153 /* 154 * Policy -- Can ucred cr1 send SIGIO to process cr2? 155 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 156 * in the right situations. 157 */ 158 #define CANSIGIO(cr1, cr2) \ 159 ((cr1)->cr_uid == 0 || \ 160 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 161 (cr1)->cr_uid == (cr2)->cr_ruid || \ 162 (cr1)->cr_ruid == (cr2)->cr_uid || \ 163 (cr1)->cr_uid == (cr2)->cr_uid) 164 165 static int sugid_coredump; 166 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 167 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 168 169 static int capmode_coredump; 170 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 171 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 172 173 static int do_coredump = 1; 174 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 175 &do_coredump, 0, "Enable/Disable coredumps"); 176 177 static int set_core_nodump_flag = 0; 178 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 179 0, "Enable setting the NODUMP flag on coredump files"); 180 181 /* 182 * Signal properties and actions. 183 * The array below categorizes the signals and their default actions 184 * according to the following properties: 185 */ 186 #define SA_KILL 0x01 /* terminates process by default */ 187 #define SA_CORE 0x02 /* ditto and coredumps */ 188 #define SA_STOP 0x04 /* suspend process */ 189 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 190 #define SA_IGNORE 0x10 /* ignore by default */ 191 #define SA_CONT 0x20 /* continue if suspended */ 192 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 193 194 static int sigproptbl[NSIG] = { 195 SA_KILL, /* SIGHUP */ 196 SA_KILL, /* SIGINT */ 197 SA_KILL|SA_CORE, /* SIGQUIT */ 198 SA_KILL|SA_CORE, /* SIGILL */ 199 SA_KILL|SA_CORE, /* SIGTRAP */ 200 SA_KILL|SA_CORE, /* SIGABRT */ 201 SA_KILL|SA_CORE, /* SIGEMT */ 202 SA_KILL|SA_CORE, /* SIGFPE */ 203 SA_KILL, /* SIGKILL */ 204 SA_KILL|SA_CORE, /* SIGBUS */ 205 SA_KILL|SA_CORE, /* SIGSEGV */ 206 SA_KILL|SA_CORE, /* SIGSYS */ 207 SA_KILL, /* SIGPIPE */ 208 SA_KILL, /* SIGALRM */ 209 SA_KILL, /* SIGTERM */ 210 SA_IGNORE, /* SIGURG */ 211 SA_STOP, /* SIGSTOP */ 212 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 213 SA_IGNORE|SA_CONT, /* SIGCONT */ 214 SA_IGNORE, /* SIGCHLD */ 215 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 216 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 217 SA_IGNORE, /* SIGIO */ 218 SA_KILL, /* SIGXCPU */ 219 SA_KILL, /* SIGXFSZ */ 220 SA_KILL, /* SIGVTALRM */ 221 SA_KILL, /* SIGPROF */ 222 SA_IGNORE, /* SIGWINCH */ 223 SA_IGNORE, /* SIGINFO */ 224 SA_KILL, /* SIGUSR1 */ 225 SA_KILL, /* SIGUSR2 */ 226 }; 227 228 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 229 230 static void 231 sigqueue_start(void) 232 { 233 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 234 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 235 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 236 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 237 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 238 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 239 } 240 241 ksiginfo_t * 242 ksiginfo_alloc(int wait) 243 { 244 int flags; 245 246 flags = M_ZERO; 247 if (! wait) 248 flags |= M_NOWAIT; 249 if (ksiginfo_zone != NULL) 250 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 251 return (NULL); 252 } 253 254 void 255 ksiginfo_free(ksiginfo_t *ksi) 256 { 257 uma_zfree(ksiginfo_zone, ksi); 258 } 259 260 static __inline int 261 ksiginfo_tryfree(ksiginfo_t *ksi) 262 { 263 if (!(ksi->ksi_flags & KSI_EXT)) { 264 uma_zfree(ksiginfo_zone, ksi); 265 return (1); 266 } 267 return (0); 268 } 269 270 void 271 sigqueue_init(sigqueue_t *list, struct proc *p) 272 { 273 SIGEMPTYSET(list->sq_signals); 274 SIGEMPTYSET(list->sq_kill); 275 TAILQ_INIT(&list->sq_list); 276 list->sq_proc = p; 277 list->sq_flags = SQ_INIT; 278 } 279 280 /* 281 * Get a signal's ksiginfo. 282 * Return: 283 * 0 - signal not found 284 * others - signal number 285 */ 286 static int 287 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 288 { 289 struct proc *p = sq->sq_proc; 290 struct ksiginfo *ksi, *next; 291 int count = 0; 292 293 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 294 295 if (!SIGISMEMBER(sq->sq_signals, signo)) 296 return (0); 297 298 if (SIGISMEMBER(sq->sq_kill, signo)) { 299 count++; 300 SIGDELSET(sq->sq_kill, signo); 301 } 302 303 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 304 if (ksi->ksi_signo == signo) { 305 if (count == 0) { 306 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 307 ksi->ksi_sigq = NULL; 308 ksiginfo_copy(ksi, si); 309 if (ksiginfo_tryfree(ksi) && p != NULL) 310 p->p_pendingcnt--; 311 } 312 if (++count > 1) 313 break; 314 } 315 } 316 317 if (count <= 1) 318 SIGDELSET(sq->sq_signals, signo); 319 si->ksi_signo = signo; 320 return (signo); 321 } 322 323 void 324 sigqueue_take(ksiginfo_t *ksi) 325 { 326 struct ksiginfo *kp; 327 struct proc *p; 328 sigqueue_t *sq; 329 330 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 331 return; 332 333 p = sq->sq_proc; 334 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 335 ksi->ksi_sigq = NULL; 336 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 337 p->p_pendingcnt--; 338 339 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 340 kp = TAILQ_NEXT(kp, ksi_link)) { 341 if (kp->ksi_signo == ksi->ksi_signo) 342 break; 343 } 344 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 345 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 346 } 347 348 static int 349 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 350 { 351 struct proc *p = sq->sq_proc; 352 struct ksiginfo *ksi; 353 int ret = 0; 354 355 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 356 357 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 358 SIGADDSET(sq->sq_kill, signo); 359 goto out_set_bit; 360 } 361 362 /* directly insert the ksi, don't copy it */ 363 if (si->ksi_flags & KSI_INS) { 364 if (si->ksi_flags & KSI_HEAD) 365 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 366 else 367 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 368 si->ksi_sigq = sq; 369 goto out_set_bit; 370 } 371 372 if (__predict_false(ksiginfo_zone == NULL)) { 373 SIGADDSET(sq->sq_kill, signo); 374 goto out_set_bit; 375 } 376 377 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 378 signal_overflow++; 379 ret = EAGAIN; 380 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 381 signal_alloc_fail++; 382 ret = EAGAIN; 383 } else { 384 if (p != NULL) 385 p->p_pendingcnt++; 386 ksiginfo_copy(si, ksi); 387 ksi->ksi_signo = signo; 388 if (si->ksi_flags & KSI_HEAD) 389 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 390 else 391 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 392 ksi->ksi_sigq = sq; 393 } 394 395 if ((si->ksi_flags & KSI_TRAP) != 0 || 396 (si->ksi_flags & KSI_SIGQ) == 0) { 397 if (ret != 0) 398 SIGADDSET(sq->sq_kill, signo); 399 ret = 0; 400 goto out_set_bit; 401 } 402 403 if (ret != 0) 404 return (ret); 405 406 out_set_bit: 407 SIGADDSET(sq->sq_signals, signo); 408 return (ret); 409 } 410 411 void 412 sigqueue_flush(sigqueue_t *sq) 413 { 414 struct proc *p = sq->sq_proc; 415 ksiginfo_t *ksi; 416 417 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 418 419 if (p != NULL) 420 PROC_LOCK_ASSERT(p, MA_OWNED); 421 422 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 423 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 424 ksi->ksi_sigq = NULL; 425 if (ksiginfo_tryfree(ksi) && p != NULL) 426 p->p_pendingcnt--; 427 } 428 429 SIGEMPTYSET(sq->sq_signals); 430 SIGEMPTYSET(sq->sq_kill); 431 } 432 433 static void 434 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 435 { 436 sigset_t tmp; 437 struct proc *p1, *p2; 438 ksiginfo_t *ksi, *next; 439 440 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 441 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 442 p1 = src->sq_proc; 443 p2 = dst->sq_proc; 444 /* Move siginfo to target list */ 445 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 446 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 447 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 448 if (p1 != NULL) 449 p1->p_pendingcnt--; 450 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = dst; 452 if (p2 != NULL) 453 p2->p_pendingcnt++; 454 } 455 } 456 457 /* Move pending bits to target list */ 458 tmp = src->sq_kill; 459 SIGSETAND(tmp, *set); 460 SIGSETOR(dst->sq_kill, tmp); 461 SIGSETNAND(src->sq_kill, tmp); 462 463 tmp = src->sq_signals; 464 SIGSETAND(tmp, *set); 465 SIGSETOR(dst->sq_signals, tmp); 466 SIGSETNAND(src->sq_signals, tmp); 467 } 468 469 #if 0 470 static void 471 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 472 { 473 sigset_t set; 474 475 SIGEMPTYSET(set); 476 SIGADDSET(set, signo); 477 sigqueue_move_set(src, dst, &set); 478 } 479 #endif 480 481 static void 482 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 483 { 484 struct proc *p = sq->sq_proc; 485 ksiginfo_t *ksi, *next; 486 487 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 488 489 /* Remove siginfo queue */ 490 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 491 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 492 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 493 ksi->ksi_sigq = NULL; 494 if (ksiginfo_tryfree(ksi) && p != NULL) 495 p->p_pendingcnt--; 496 } 497 } 498 SIGSETNAND(sq->sq_kill, *set); 499 SIGSETNAND(sq->sq_signals, *set); 500 } 501 502 void 503 sigqueue_delete(sigqueue_t *sq, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_delete_set(sq, &set); 510 } 511 512 /* Remove a set of signals for a process */ 513 static void 514 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 515 { 516 sigqueue_t worklist; 517 struct thread *td0; 518 519 PROC_LOCK_ASSERT(p, MA_OWNED); 520 521 sigqueue_init(&worklist, NULL); 522 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 523 524 FOREACH_THREAD_IN_PROC(p, td0) 525 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 526 527 sigqueue_flush(&worklist); 528 } 529 530 void 531 sigqueue_delete_proc(struct proc *p, int signo) 532 { 533 sigset_t set; 534 535 SIGEMPTYSET(set); 536 SIGADDSET(set, signo); 537 sigqueue_delete_set_proc(p, &set); 538 } 539 540 static void 541 sigqueue_delete_stopmask_proc(struct proc *p) 542 { 543 sigset_t set; 544 545 SIGEMPTYSET(set); 546 SIGADDSET(set, SIGSTOP); 547 SIGADDSET(set, SIGTSTP); 548 SIGADDSET(set, SIGTTIN); 549 SIGADDSET(set, SIGTTOU); 550 sigqueue_delete_set_proc(p, &set); 551 } 552 553 /* 554 * Determine signal that should be delivered to thread td, the current 555 * thread, 0 if none. If there is a pending stop signal with default 556 * action, the process stops in issignal(). 557 */ 558 int 559 cursig(struct thread *td) 560 { 561 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 562 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 563 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 564 return (SIGPENDING(td) ? issignal(td) : 0); 565 } 566 567 /* 568 * Arrange for ast() to handle unmasked pending signals on return to user 569 * mode. This must be called whenever a signal is added to td_sigqueue or 570 * unmasked in td_sigmask. 571 */ 572 void 573 signotify(struct thread *td) 574 { 575 struct proc *p; 576 577 p = td->td_proc; 578 579 PROC_LOCK_ASSERT(p, MA_OWNED); 580 581 if (SIGPENDING(td)) { 582 thread_lock(td); 583 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 584 thread_unlock(td); 585 } 586 } 587 588 int 589 sigonstack(size_t sp) 590 { 591 struct thread *td = curthread; 592 593 return ((td->td_pflags & TDP_ALTSTACK) ? 594 #if defined(COMPAT_43) 595 ((td->td_sigstk.ss_size == 0) ? 596 (td->td_sigstk.ss_flags & SS_ONSTACK) : 597 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 598 #else 599 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 600 #endif 601 : 0); 602 } 603 604 static __inline int 605 sigprop(int sig) 606 { 607 608 if (sig > 0 && sig < NSIG) 609 return (sigproptbl[_SIG_IDX(sig)]); 610 return (0); 611 } 612 613 int 614 sig_ffs(sigset_t *set) 615 { 616 int i; 617 618 for (i = 0; i < _SIG_WORDS; i++) 619 if (set->__bits[i]) 620 return (ffs(set->__bits[i]) + (i * 32)); 621 return (0); 622 } 623 624 /* 625 * kern_sigaction 626 * sigaction 627 * freebsd4_sigaction 628 * osigaction 629 */ 630 int 631 kern_sigaction(td, sig, act, oact, flags) 632 struct thread *td; 633 register int sig; 634 struct sigaction *act, *oact; 635 int flags; 636 { 637 struct sigacts *ps; 638 struct proc *p = td->td_proc; 639 640 if (!_SIG_VALID(sig)) 641 return (EINVAL); 642 643 PROC_LOCK(p); 644 ps = p->p_sigacts; 645 mtx_lock(&ps->ps_mtx); 646 if (oact) { 647 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 648 oact->sa_flags = 0; 649 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 650 oact->sa_flags |= SA_ONSTACK; 651 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 652 oact->sa_flags |= SA_RESTART; 653 if (SIGISMEMBER(ps->ps_sigreset, sig)) 654 oact->sa_flags |= SA_RESETHAND; 655 if (SIGISMEMBER(ps->ps_signodefer, sig)) 656 oact->sa_flags |= SA_NODEFER; 657 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 658 oact->sa_flags |= SA_SIGINFO; 659 oact->sa_sigaction = 660 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 661 } else 662 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 663 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 664 oact->sa_flags |= SA_NOCLDSTOP; 665 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 666 oact->sa_flags |= SA_NOCLDWAIT; 667 } 668 if (act) { 669 if ((sig == SIGKILL || sig == SIGSTOP) && 670 act->sa_handler != SIG_DFL) { 671 mtx_unlock(&ps->ps_mtx); 672 PROC_UNLOCK(p); 673 return (EINVAL); 674 } 675 676 /* 677 * Change setting atomically. 678 */ 679 680 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 681 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 682 if (act->sa_flags & SA_SIGINFO) { 683 ps->ps_sigact[_SIG_IDX(sig)] = 684 (__sighandler_t *)act->sa_sigaction; 685 SIGADDSET(ps->ps_siginfo, sig); 686 } else { 687 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 688 SIGDELSET(ps->ps_siginfo, sig); 689 } 690 if (!(act->sa_flags & SA_RESTART)) 691 SIGADDSET(ps->ps_sigintr, sig); 692 else 693 SIGDELSET(ps->ps_sigintr, sig); 694 if (act->sa_flags & SA_ONSTACK) 695 SIGADDSET(ps->ps_sigonstack, sig); 696 else 697 SIGDELSET(ps->ps_sigonstack, sig); 698 if (act->sa_flags & SA_RESETHAND) 699 SIGADDSET(ps->ps_sigreset, sig); 700 else 701 SIGDELSET(ps->ps_sigreset, sig); 702 if (act->sa_flags & SA_NODEFER) 703 SIGADDSET(ps->ps_signodefer, sig); 704 else 705 SIGDELSET(ps->ps_signodefer, sig); 706 if (sig == SIGCHLD) { 707 if (act->sa_flags & SA_NOCLDSTOP) 708 ps->ps_flag |= PS_NOCLDSTOP; 709 else 710 ps->ps_flag &= ~PS_NOCLDSTOP; 711 if (act->sa_flags & SA_NOCLDWAIT) { 712 /* 713 * Paranoia: since SA_NOCLDWAIT is implemented 714 * by reparenting the dying child to PID 1 (and 715 * trust it to reap the zombie), PID 1 itself 716 * is forbidden to set SA_NOCLDWAIT. 717 */ 718 if (p->p_pid == 1) 719 ps->ps_flag &= ~PS_NOCLDWAIT; 720 else 721 ps->ps_flag |= PS_NOCLDWAIT; 722 } else 723 ps->ps_flag &= ~PS_NOCLDWAIT; 724 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 725 ps->ps_flag |= PS_CLDSIGIGN; 726 else 727 ps->ps_flag &= ~PS_CLDSIGIGN; 728 } 729 /* 730 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 731 * and for signals set to SIG_DFL where the default is to 732 * ignore. However, don't put SIGCONT in ps_sigignore, as we 733 * have to restart the process. 734 */ 735 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 736 (sigprop(sig) & SA_IGNORE && 737 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 738 /* never to be seen again */ 739 sigqueue_delete_proc(p, sig); 740 if (sig != SIGCONT) 741 /* easier in psignal */ 742 SIGADDSET(ps->ps_sigignore, sig); 743 SIGDELSET(ps->ps_sigcatch, sig); 744 } else { 745 SIGDELSET(ps->ps_sigignore, sig); 746 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 747 SIGDELSET(ps->ps_sigcatch, sig); 748 else 749 SIGADDSET(ps->ps_sigcatch, sig); 750 } 751 #ifdef COMPAT_FREEBSD4 752 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 753 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 754 (flags & KSA_FREEBSD4) == 0) 755 SIGDELSET(ps->ps_freebsd4, sig); 756 else 757 SIGADDSET(ps->ps_freebsd4, sig); 758 #endif 759 #ifdef COMPAT_43 760 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 761 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 762 (flags & KSA_OSIGSET) == 0) 763 SIGDELSET(ps->ps_osigset, sig); 764 else 765 SIGADDSET(ps->ps_osigset, sig); 766 #endif 767 } 768 mtx_unlock(&ps->ps_mtx); 769 PROC_UNLOCK(p); 770 return (0); 771 } 772 773 #ifndef _SYS_SYSPROTO_H_ 774 struct sigaction_args { 775 int sig; 776 struct sigaction *act; 777 struct sigaction *oact; 778 }; 779 #endif 780 int 781 sys_sigaction(td, uap) 782 struct thread *td; 783 register struct sigaction_args *uap; 784 { 785 struct sigaction act, oact; 786 register struct sigaction *actp, *oactp; 787 int error; 788 789 actp = (uap->act != NULL) ? &act : NULL; 790 oactp = (uap->oact != NULL) ? &oact : NULL; 791 if (actp) { 792 error = copyin(uap->act, actp, sizeof(act)); 793 if (error) 794 return (error); 795 } 796 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 797 if (oactp && !error) 798 error = copyout(oactp, uap->oact, sizeof(oact)); 799 return (error); 800 } 801 802 #ifdef COMPAT_FREEBSD4 803 #ifndef _SYS_SYSPROTO_H_ 804 struct freebsd4_sigaction_args { 805 int sig; 806 struct sigaction *act; 807 struct sigaction *oact; 808 }; 809 #endif 810 int 811 freebsd4_sigaction(td, uap) 812 struct thread *td; 813 register struct freebsd4_sigaction_args *uap; 814 { 815 struct sigaction act, oact; 816 register struct sigaction *actp, *oactp; 817 int error; 818 819 820 actp = (uap->act != NULL) ? &act : NULL; 821 oactp = (uap->oact != NULL) ? &oact : NULL; 822 if (actp) { 823 error = copyin(uap->act, actp, sizeof(act)); 824 if (error) 825 return (error); 826 } 827 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 828 if (oactp && !error) 829 error = copyout(oactp, uap->oact, sizeof(oact)); 830 return (error); 831 } 832 #endif /* COMAPT_FREEBSD4 */ 833 834 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 835 #ifndef _SYS_SYSPROTO_H_ 836 struct osigaction_args { 837 int signum; 838 struct osigaction *nsa; 839 struct osigaction *osa; 840 }; 841 #endif 842 int 843 osigaction(td, uap) 844 struct thread *td; 845 register struct osigaction_args *uap; 846 { 847 struct osigaction sa; 848 struct sigaction nsa, osa; 849 register struct sigaction *nsap, *osap; 850 int error; 851 852 if (uap->signum <= 0 || uap->signum >= ONSIG) 853 return (EINVAL); 854 855 nsap = (uap->nsa != NULL) ? &nsa : NULL; 856 osap = (uap->osa != NULL) ? &osa : NULL; 857 858 if (nsap) { 859 error = copyin(uap->nsa, &sa, sizeof(sa)); 860 if (error) 861 return (error); 862 nsap->sa_handler = sa.sa_handler; 863 nsap->sa_flags = sa.sa_flags; 864 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 865 } 866 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 867 if (osap && !error) { 868 sa.sa_handler = osap->sa_handler; 869 sa.sa_flags = osap->sa_flags; 870 SIG2OSIG(osap->sa_mask, sa.sa_mask); 871 error = copyout(&sa, uap->osa, sizeof(sa)); 872 } 873 return (error); 874 } 875 876 #if !defined(__i386__) 877 /* Avoid replicating the same stub everywhere */ 878 int 879 osigreturn(td, uap) 880 struct thread *td; 881 struct osigreturn_args *uap; 882 { 883 884 return (nosys(td, (struct nosys_args *)uap)); 885 } 886 #endif 887 #endif /* COMPAT_43 */ 888 889 /* 890 * Initialize signal state for process 0; 891 * set to ignore signals that are ignored by default. 892 */ 893 void 894 siginit(p) 895 struct proc *p; 896 { 897 register int i; 898 struct sigacts *ps; 899 900 PROC_LOCK(p); 901 ps = p->p_sigacts; 902 mtx_lock(&ps->ps_mtx); 903 for (i = 1; i <= NSIG; i++) 904 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 905 SIGADDSET(ps->ps_sigignore, i); 906 mtx_unlock(&ps->ps_mtx); 907 PROC_UNLOCK(p); 908 } 909 910 /* 911 * Reset signals for an exec of the specified process. 912 */ 913 void 914 execsigs(struct proc *p) 915 { 916 struct sigacts *ps; 917 int sig; 918 struct thread *td; 919 920 /* 921 * Reset caught signals. Held signals remain held 922 * through td_sigmask (unless they were caught, 923 * and are now ignored by default). 924 */ 925 PROC_LOCK_ASSERT(p, MA_OWNED); 926 td = FIRST_THREAD_IN_PROC(p); 927 ps = p->p_sigacts; 928 mtx_lock(&ps->ps_mtx); 929 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 930 sig = sig_ffs(&ps->ps_sigcatch); 931 SIGDELSET(ps->ps_sigcatch, sig); 932 if (sigprop(sig) & SA_IGNORE) { 933 if (sig != SIGCONT) 934 SIGADDSET(ps->ps_sigignore, sig); 935 sigqueue_delete_proc(p, sig); 936 } 937 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 938 } 939 /* 940 * Reset stack state to the user stack. 941 * Clear set of signals caught on the signal stack. 942 */ 943 td->td_sigstk.ss_flags = SS_DISABLE; 944 td->td_sigstk.ss_size = 0; 945 td->td_sigstk.ss_sp = 0; 946 td->td_pflags &= ~TDP_ALTSTACK; 947 /* 948 * Reset no zombies if child dies flag as Solaris does. 949 */ 950 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 951 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 952 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 953 mtx_unlock(&ps->ps_mtx); 954 } 955 956 /* 957 * kern_sigprocmask() 958 * 959 * Manipulate signal mask. 960 */ 961 int 962 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 963 int flags) 964 { 965 sigset_t new_block, oset1; 966 struct proc *p; 967 int error; 968 969 p = td->td_proc; 970 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 971 PROC_LOCK(p); 972 if (oset != NULL) 973 *oset = td->td_sigmask; 974 975 error = 0; 976 if (set != NULL) { 977 switch (how) { 978 case SIG_BLOCK: 979 SIG_CANTMASK(*set); 980 oset1 = td->td_sigmask; 981 SIGSETOR(td->td_sigmask, *set); 982 new_block = td->td_sigmask; 983 SIGSETNAND(new_block, oset1); 984 break; 985 case SIG_UNBLOCK: 986 SIGSETNAND(td->td_sigmask, *set); 987 signotify(td); 988 goto out; 989 case SIG_SETMASK: 990 SIG_CANTMASK(*set); 991 oset1 = td->td_sigmask; 992 if (flags & SIGPROCMASK_OLD) 993 SIGSETLO(td->td_sigmask, *set); 994 else 995 td->td_sigmask = *set; 996 new_block = td->td_sigmask; 997 SIGSETNAND(new_block, oset1); 998 signotify(td); 999 break; 1000 default: 1001 error = EINVAL; 1002 goto out; 1003 } 1004 1005 /* 1006 * The new_block set contains signals that were not previously 1007 * blocked, but are blocked now. 1008 * 1009 * In case we block any signal that was not previously blocked 1010 * for td, and process has the signal pending, try to schedule 1011 * signal delivery to some thread that does not block the 1012 * signal, possibly waking it up. 1013 */ 1014 if (p->p_numthreads != 1) 1015 reschedule_signals(p, new_block, flags); 1016 } 1017 1018 out: 1019 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1020 PROC_UNLOCK(p); 1021 return (error); 1022 } 1023 1024 #ifndef _SYS_SYSPROTO_H_ 1025 struct sigprocmask_args { 1026 int how; 1027 const sigset_t *set; 1028 sigset_t *oset; 1029 }; 1030 #endif 1031 int 1032 sys_sigprocmask(td, uap) 1033 register struct thread *td; 1034 struct sigprocmask_args *uap; 1035 { 1036 sigset_t set, oset; 1037 sigset_t *setp, *osetp; 1038 int error; 1039 1040 setp = (uap->set != NULL) ? &set : NULL; 1041 osetp = (uap->oset != NULL) ? &oset : NULL; 1042 if (setp) { 1043 error = copyin(uap->set, setp, sizeof(set)); 1044 if (error) 1045 return (error); 1046 } 1047 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1048 if (osetp && !error) { 1049 error = copyout(osetp, uap->oset, sizeof(oset)); 1050 } 1051 return (error); 1052 } 1053 1054 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1055 #ifndef _SYS_SYSPROTO_H_ 1056 struct osigprocmask_args { 1057 int how; 1058 osigset_t mask; 1059 }; 1060 #endif 1061 int 1062 osigprocmask(td, uap) 1063 register struct thread *td; 1064 struct osigprocmask_args *uap; 1065 { 1066 sigset_t set, oset; 1067 int error; 1068 1069 OSIG2SIG(uap->mask, set); 1070 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1071 SIG2OSIG(oset, td->td_retval[0]); 1072 return (error); 1073 } 1074 #endif /* COMPAT_43 */ 1075 1076 int 1077 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1078 { 1079 ksiginfo_t ksi; 1080 sigset_t set; 1081 int error; 1082 1083 error = copyin(uap->set, &set, sizeof(set)); 1084 if (error) { 1085 td->td_retval[0] = error; 1086 return (0); 1087 } 1088 1089 error = kern_sigtimedwait(td, set, &ksi, NULL); 1090 if (error) { 1091 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1092 error = ERESTART; 1093 if (error == ERESTART) 1094 return (error); 1095 td->td_retval[0] = error; 1096 return (0); 1097 } 1098 1099 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1100 td->td_retval[0] = error; 1101 return (0); 1102 } 1103 1104 int 1105 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1106 { 1107 struct timespec ts; 1108 struct timespec *timeout; 1109 sigset_t set; 1110 ksiginfo_t ksi; 1111 int error; 1112 1113 if (uap->timeout) { 1114 error = copyin(uap->timeout, &ts, sizeof(ts)); 1115 if (error) 1116 return (error); 1117 1118 timeout = &ts; 1119 } else 1120 timeout = NULL; 1121 1122 error = copyin(uap->set, &set, sizeof(set)); 1123 if (error) 1124 return (error); 1125 1126 error = kern_sigtimedwait(td, set, &ksi, timeout); 1127 if (error) 1128 return (error); 1129 1130 if (uap->info) 1131 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1132 1133 if (error == 0) 1134 td->td_retval[0] = ksi.ksi_signo; 1135 return (error); 1136 } 1137 1138 int 1139 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1140 { 1141 ksiginfo_t ksi; 1142 sigset_t set; 1143 int error; 1144 1145 error = copyin(uap->set, &set, sizeof(set)); 1146 if (error) 1147 return (error); 1148 1149 error = kern_sigtimedwait(td, set, &ksi, NULL); 1150 if (error) 1151 return (error); 1152 1153 if (uap->info) 1154 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1155 1156 if (error == 0) 1157 td->td_retval[0] = ksi.ksi_signo; 1158 return (error); 1159 } 1160 1161 int 1162 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1163 struct timespec *timeout) 1164 { 1165 struct sigacts *ps; 1166 sigset_t saved_mask, new_block; 1167 struct proc *p; 1168 int error, sig, timo, timevalid = 0; 1169 struct timespec rts, ets, ts; 1170 struct timeval tv; 1171 1172 p = td->td_proc; 1173 error = 0; 1174 ets.tv_sec = 0; 1175 ets.tv_nsec = 0; 1176 1177 if (timeout != NULL) { 1178 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1179 timevalid = 1; 1180 getnanouptime(&rts); 1181 ets = rts; 1182 timespecadd(&ets, timeout); 1183 } 1184 } 1185 ksiginfo_init(ksi); 1186 /* Some signals can not be waited for. */ 1187 SIG_CANTMASK(waitset); 1188 ps = p->p_sigacts; 1189 PROC_LOCK(p); 1190 saved_mask = td->td_sigmask; 1191 SIGSETNAND(td->td_sigmask, waitset); 1192 for (;;) { 1193 mtx_lock(&ps->ps_mtx); 1194 sig = cursig(td); 1195 mtx_unlock(&ps->ps_mtx); 1196 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1197 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1198 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1199 error = 0; 1200 break; 1201 } 1202 } 1203 1204 if (error != 0) 1205 break; 1206 1207 /* 1208 * POSIX says this must be checked after looking for pending 1209 * signals. 1210 */ 1211 if (timeout != NULL) { 1212 if (!timevalid) { 1213 error = EINVAL; 1214 break; 1215 } 1216 getnanouptime(&rts); 1217 if (timespeccmp(&rts, &ets, >=)) { 1218 error = EAGAIN; 1219 break; 1220 } 1221 ts = ets; 1222 timespecsub(&ts, &rts); 1223 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1224 timo = tvtohz(&tv); 1225 } else { 1226 timo = 0; 1227 } 1228 1229 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1230 1231 if (timeout != NULL) { 1232 if (error == ERESTART) { 1233 /* Timeout can not be restarted. */ 1234 error = EINTR; 1235 } else if (error == EAGAIN) { 1236 /* We will calculate timeout by ourself. */ 1237 error = 0; 1238 } 1239 } 1240 } 1241 1242 new_block = saved_mask; 1243 SIGSETNAND(new_block, td->td_sigmask); 1244 td->td_sigmask = saved_mask; 1245 /* 1246 * Fewer signals can be delivered to us, reschedule signal 1247 * notification. 1248 */ 1249 if (p->p_numthreads != 1) 1250 reschedule_signals(p, new_block, 0); 1251 1252 if (error == 0) { 1253 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0); 1254 1255 if (ksi->ksi_code == SI_TIMER) 1256 itimer_accept(p, ksi->ksi_timerid, ksi); 1257 1258 #ifdef KTRACE 1259 if (KTRPOINT(td, KTR_PSIG)) { 1260 sig_t action; 1261 1262 mtx_lock(&ps->ps_mtx); 1263 action = ps->ps_sigact[_SIG_IDX(sig)]; 1264 mtx_unlock(&ps->ps_mtx); 1265 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1266 } 1267 #endif 1268 if (sig == SIGKILL) 1269 sigexit(td, sig); 1270 } 1271 PROC_UNLOCK(p); 1272 return (error); 1273 } 1274 1275 #ifndef _SYS_SYSPROTO_H_ 1276 struct sigpending_args { 1277 sigset_t *set; 1278 }; 1279 #endif 1280 int 1281 sys_sigpending(td, uap) 1282 struct thread *td; 1283 struct sigpending_args *uap; 1284 { 1285 struct proc *p = td->td_proc; 1286 sigset_t pending; 1287 1288 PROC_LOCK(p); 1289 pending = p->p_sigqueue.sq_signals; 1290 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1291 PROC_UNLOCK(p); 1292 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1293 } 1294 1295 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1296 #ifndef _SYS_SYSPROTO_H_ 1297 struct osigpending_args { 1298 int dummy; 1299 }; 1300 #endif 1301 int 1302 osigpending(td, uap) 1303 struct thread *td; 1304 struct osigpending_args *uap; 1305 { 1306 struct proc *p = td->td_proc; 1307 sigset_t pending; 1308 1309 PROC_LOCK(p); 1310 pending = p->p_sigqueue.sq_signals; 1311 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1312 PROC_UNLOCK(p); 1313 SIG2OSIG(pending, td->td_retval[0]); 1314 return (0); 1315 } 1316 #endif /* COMPAT_43 */ 1317 1318 #if defined(COMPAT_43) 1319 /* 1320 * Generalized interface signal handler, 4.3-compatible. 1321 */ 1322 #ifndef _SYS_SYSPROTO_H_ 1323 struct osigvec_args { 1324 int signum; 1325 struct sigvec *nsv; 1326 struct sigvec *osv; 1327 }; 1328 #endif 1329 /* ARGSUSED */ 1330 int 1331 osigvec(td, uap) 1332 struct thread *td; 1333 register struct osigvec_args *uap; 1334 { 1335 struct sigvec vec; 1336 struct sigaction nsa, osa; 1337 register struct sigaction *nsap, *osap; 1338 int error; 1339 1340 if (uap->signum <= 0 || uap->signum >= ONSIG) 1341 return (EINVAL); 1342 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1343 osap = (uap->osv != NULL) ? &osa : NULL; 1344 if (nsap) { 1345 error = copyin(uap->nsv, &vec, sizeof(vec)); 1346 if (error) 1347 return (error); 1348 nsap->sa_handler = vec.sv_handler; 1349 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1350 nsap->sa_flags = vec.sv_flags; 1351 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1352 } 1353 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1354 if (osap && !error) { 1355 vec.sv_handler = osap->sa_handler; 1356 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1357 vec.sv_flags = osap->sa_flags; 1358 vec.sv_flags &= ~SA_NOCLDWAIT; 1359 vec.sv_flags ^= SA_RESTART; 1360 error = copyout(&vec, uap->osv, sizeof(vec)); 1361 } 1362 return (error); 1363 } 1364 1365 #ifndef _SYS_SYSPROTO_H_ 1366 struct osigblock_args { 1367 int mask; 1368 }; 1369 #endif 1370 int 1371 osigblock(td, uap) 1372 register struct thread *td; 1373 struct osigblock_args *uap; 1374 { 1375 sigset_t set, oset; 1376 1377 OSIG2SIG(uap->mask, set); 1378 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1379 SIG2OSIG(oset, td->td_retval[0]); 1380 return (0); 1381 } 1382 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigsetmask_args { 1385 int mask; 1386 }; 1387 #endif 1388 int 1389 osigsetmask(td, uap) 1390 struct thread *td; 1391 struct osigsetmask_args *uap; 1392 { 1393 sigset_t set, oset; 1394 1395 OSIG2SIG(uap->mask, set); 1396 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1397 SIG2OSIG(oset, td->td_retval[0]); 1398 return (0); 1399 } 1400 #endif /* COMPAT_43 */ 1401 1402 /* 1403 * Suspend calling thread until signal, providing mask to be set in the 1404 * meantime. 1405 */ 1406 #ifndef _SYS_SYSPROTO_H_ 1407 struct sigsuspend_args { 1408 const sigset_t *sigmask; 1409 }; 1410 #endif 1411 /* ARGSUSED */ 1412 int 1413 sys_sigsuspend(td, uap) 1414 struct thread *td; 1415 struct sigsuspend_args *uap; 1416 { 1417 sigset_t mask; 1418 int error; 1419 1420 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1421 if (error) 1422 return (error); 1423 return (kern_sigsuspend(td, mask)); 1424 } 1425 1426 int 1427 kern_sigsuspend(struct thread *td, sigset_t mask) 1428 { 1429 struct proc *p = td->td_proc; 1430 int has_sig, sig; 1431 1432 /* 1433 * When returning from sigsuspend, we want 1434 * the old mask to be restored after the 1435 * signal handler has finished. Thus, we 1436 * save it here and mark the sigacts structure 1437 * to indicate this. 1438 */ 1439 PROC_LOCK(p); 1440 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1441 SIGPROCMASK_PROC_LOCKED); 1442 td->td_pflags |= TDP_OLDMASK; 1443 1444 /* 1445 * Process signals now. Otherwise, we can get spurious wakeup 1446 * due to signal entered process queue, but delivered to other 1447 * thread. But sigsuspend should return only on signal 1448 * delivery. 1449 */ 1450 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1451 for (has_sig = 0; !has_sig;) { 1452 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1453 0) == 0) 1454 /* void */; 1455 thread_suspend_check(0); 1456 mtx_lock(&p->p_sigacts->ps_mtx); 1457 while ((sig = cursig(td)) != 0) 1458 has_sig += postsig(sig); 1459 mtx_unlock(&p->p_sigacts->ps_mtx); 1460 } 1461 PROC_UNLOCK(p); 1462 td->td_errno = EINTR; 1463 td->td_pflags |= TDP_NERRNO; 1464 return (EJUSTRETURN); 1465 } 1466 1467 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1468 /* 1469 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1470 * convention: libc stub passes mask, not pointer, to save a copyin. 1471 */ 1472 #ifndef _SYS_SYSPROTO_H_ 1473 struct osigsuspend_args { 1474 osigset_t mask; 1475 }; 1476 #endif 1477 /* ARGSUSED */ 1478 int 1479 osigsuspend(td, uap) 1480 struct thread *td; 1481 struct osigsuspend_args *uap; 1482 { 1483 sigset_t mask; 1484 1485 OSIG2SIG(uap->mask, mask); 1486 return (kern_sigsuspend(td, mask)); 1487 } 1488 #endif /* COMPAT_43 */ 1489 1490 #if defined(COMPAT_43) 1491 #ifndef _SYS_SYSPROTO_H_ 1492 struct osigstack_args { 1493 struct sigstack *nss; 1494 struct sigstack *oss; 1495 }; 1496 #endif 1497 /* ARGSUSED */ 1498 int 1499 osigstack(td, uap) 1500 struct thread *td; 1501 register struct osigstack_args *uap; 1502 { 1503 struct sigstack nss, oss; 1504 int error = 0; 1505 1506 if (uap->nss != NULL) { 1507 error = copyin(uap->nss, &nss, sizeof(nss)); 1508 if (error) 1509 return (error); 1510 } 1511 oss.ss_sp = td->td_sigstk.ss_sp; 1512 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1513 if (uap->nss != NULL) { 1514 td->td_sigstk.ss_sp = nss.ss_sp; 1515 td->td_sigstk.ss_size = 0; 1516 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1517 td->td_pflags |= TDP_ALTSTACK; 1518 } 1519 if (uap->oss != NULL) 1520 error = copyout(&oss, uap->oss, sizeof(oss)); 1521 1522 return (error); 1523 } 1524 #endif /* COMPAT_43 */ 1525 1526 #ifndef _SYS_SYSPROTO_H_ 1527 struct sigaltstack_args { 1528 stack_t *ss; 1529 stack_t *oss; 1530 }; 1531 #endif 1532 /* ARGSUSED */ 1533 int 1534 sys_sigaltstack(td, uap) 1535 struct thread *td; 1536 register struct sigaltstack_args *uap; 1537 { 1538 stack_t ss, oss; 1539 int error; 1540 1541 if (uap->ss != NULL) { 1542 error = copyin(uap->ss, &ss, sizeof(ss)); 1543 if (error) 1544 return (error); 1545 } 1546 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1547 (uap->oss != NULL) ? &oss : NULL); 1548 if (error) 1549 return (error); 1550 if (uap->oss != NULL) 1551 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1552 return (error); 1553 } 1554 1555 int 1556 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1557 { 1558 struct proc *p = td->td_proc; 1559 int oonstack; 1560 1561 oonstack = sigonstack(cpu_getstack(td)); 1562 1563 if (oss != NULL) { 1564 *oss = td->td_sigstk; 1565 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1566 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1567 } 1568 1569 if (ss != NULL) { 1570 if (oonstack) 1571 return (EPERM); 1572 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1573 return (EINVAL); 1574 if (!(ss->ss_flags & SS_DISABLE)) { 1575 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1576 return (ENOMEM); 1577 1578 td->td_sigstk = *ss; 1579 td->td_pflags |= TDP_ALTSTACK; 1580 } else { 1581 td->td_pflags &= ~TDP_ALTSTACK; 1582 } 1583 } 1584 return (0); 1585 } 1586 1587 /* 1588 * Common code for kill process group/broadcast kill. 1589 * cp is calling process. 1590 */ 1591 static int 1592 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1593 { 1594 struct proc *p; 1595 struct pgrp *pgrp; 1596 int err; 1597 int ret; 1598 1599 ret = ESRCH; 1600 if (all) { 1601 /* 1602 * broadcast 1603 */ 1604 sx_slock(&allproc_lock); 1605 FOREACH_PROC_IN_SYSTEM(p) { 1606 PROC_LOCK(p); 1607 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1608 p == td->td_proc || p->p_state == PRS_NEW) { 1609 PROC_UNLOCK(p); 1610 continue; 1611 } 1612 err = p_cansignal(td, p, sig); 1613 if (err == 0) { 1614 if (sig) 1615 pksignal(p, sig, ksi); 1616 ret = err; 1617 } 1618 else if (ret == ESRCH) 1619 ret = err; 1620 PROC_UNLOCK(p); 1621 } 1622 sx_sunlock(&allproc_lock); 1623 } else { 1624 sx_slock(&proctree_lock); 1625 if (pgid == 0) { 1626 /* 1627 * zero pgid means send to my process group. 1628 */ 1629 pgrp = td->td_proc->p_pgrp; 1630 PGRP_LOCK(pgrp); 1631 } else { 1632 pgrp = pgfind(pgid); 1633 if (pgrp == NULL) { 1634 sx_sunlock(&proctree_lock); 1635 return (ESRCH); 1636 } 1637 } 1638 sx_sunlock(&proctree_lock); 1639 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1640 PROC_LOCK(p); 1641 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1642 p->p_state == PRS_NEW) { 1643 PROC_UNLOCK(p); 1644 continue; 1645 } 1646 err = p_cansignal(td, p, sig); 1647 if (err == 0) { 1648 if (sig) 1649 pksignal(p, sig, ksi); 1650 ret = err; 1651 } 1652 else if (ret == ESRCH) 1653 ret = err; 1654 PROC_UNLOCK(p); 1655 } 1656 PGRP_UNLOCK(pgrp); 1657 } 1658 return (ret); 1659 } 1660 1661 #ifndef _SYS_SYSPROTO_H_ 1662 struct kill_args { 1663 int pid; 1664 int signum; 1665 }; 1666 #endif 1667 /* ARGSUSED */ 1668 int 1669 sys_kill(struct thread *td, struct kill_args *uap) 1670 { 1671 ksiginfo_t ksi; 1672 struct proc *p; 1673 int error; 1674 1675 /* 1676 * A process in capability mode can send signals only to himself. 1677 * The main rationale behind this is that abort(3) is implemented as 1678 * kill(getpid(), SIGABRT). 1679 */ 1680 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1681 return (ECAPMODE); 1682 1683 AUDIT_ARG_SIGNUM(uap->signum); 1684 AUDIT_ARG_PID(uap->pid); 1685 if ((u_int)uap->signum > _SIG_MAXSIG) 1686 return (EINVAL); 1687 1688 ksiginfo_init(&ksi); 1689 ksi.ksi_signo = uap->signum; 1690 ksi.ksi_code = SI_USER; 1691 ksi.ksi_pid = td->td_proc->p_pid; 1692 ksi.ksi_uid = td->td_ucred->cr_ruid; 1693 1694 if (uap->pid > 0) { 1695 /* kill single process */ 1696 if ((p = pfind(uap->pid)) == NULL) { 1697 if ((p = zpfind(uap->pid)) == NULL) 1698 return (ESRCH); 1699 } 1700 AUDIT_ARG_PROCESS(p); 1701 error = p_cansignal(td, p, uap->signum); 1702 if (error == 0 && uap->signum) 1703 pksignal(p, uap->signum, &ksi); 1704 PROC_UNLOCK(p); 1705 return (error); 1706 } 1707 switch (uap->pid) { 1708 case -1: /* broadcast signal */ 1709 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1710 case 0: /* signal own process group */ 1711 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1712 default: /* negative explicit process group */ 1713 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1714 } 1715 /* NOTREACHED */ 1716 } 1717 1718 int 1719 sys_pdkill(td, uap) 1720 struct thread *td; 1721 struct pdkill_args *uap; 1722 { 1723 struct proc *p; 1724 cap_rights_t rights; 1725 int error; 1726 1727 AUDIT_ARG_SIGNUM(uap->signum); 1728 AUDIT_ARG_FD(uap->fd); 1729 if ((u_int)uap->signum > _SIG_MAXSIG) 1730 return (EINVAL); 1731 1732 error = procdesc_find(td, uap->fd, 1733 cap_rights_init(&rights, CAP_PDKILL), &p); 1734 if (error) 1735 return (error); 1736 AUDIT_ARG_PROCESS(p); 1737 error = p_cansignal(td, p, uap->signum); 1738 if (error == 0 && uap->signum) 1739 kern_psignal(p, uap->signum); 1740 PROC_UNLOCK(p); 1741 return (error); 1742 } 1743 1744 #if defined(COMPAT_43) 1745 #ifndef _SYS_SYSPROTO_H_ 1746 struct okillpg_args { 1747 int pgid; 1748 int signum; 1749 }; 1750 #endif 1751 /* ARGSUSED */ 1752 int 1753 okillpg(struct thread *td, struct okillpg_args *uap) 1754 { 1755 ksiginfo_t ksi; 1756 1757 AUDIT_ARG_SIGNUM(uap->signum); 1758 AUDIT_ARG_PID(uap->pgid); 1759 if ((u_int)uap->signum > _SIG_MAXSIG) 1760 return (EINVAL); 1761 1762 ksiginfo_init(&ksi); 1763 ksi.ksi_signo = uap->signum; 1764 ksi.ksi_code = SI_USER; 1765 ksi.ksi_pid = td->td_proc->p_pid; 1766 ksi.ksi_uid = td->td_ucred->cr_ruid; 1767 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1768 } 1769 #endif /* COMPAT_43 */ 1770 1771 #ifndef _SYS_SYSPROTO_H_ 1772 struct sigqueue_args { 1773 pid_t pid; 1774 int signum; 1775 /* union sigval */ void *value; 1776 }; 1777 #endif 1778 int 1779 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1780 { 1781 ksiginfo_t ksi; 1782 struct proc *p; 1783 int error; 1784 1785 if ((u_int)uap->signum > _SIG_MAXSIG) 1786 return (EINVAL); 1787 1788 /* 1789 * Specification says sigqueue can only send signal to 1790 * single process. 1791 */ 1792 if (uap->pid <= 0) 1793 return (EINVAL); 1794 1795 if ((p = pfind(uap->pid)) == NULL) { 1796 if ((p = zpfind(uap->pid)) == NULL) 1797 return (ESRCH); 1798 } 1799 error = p_cansignal(td, p, uap->signum); 1800 if (error == 0 && uap->signum != 0) { 1801 ksiginfo_init(&ksi); 1802 ksi.ksi_flags = KSI_SIGQ; 1803 ksi.ksi_signo = uap->signum; 1804 ksi.ksi_code = SI_QUEUE; 1805 ksi.ksi_pid = td->td_proc->p_pid; 1806 ksi.ksi_uid = td->td_ucred->cr_ruid; 1807 ksi.ksi_value.sival_ptr = uap->value; 1808 error = pksignal(p, ksi.ksi_signo, &ksi); 1809 } 1810 PROC_UNLOCK(p); 1811 return (error); 1812 } 1813 1814 /* 1815 * Send a signal to a process group. 1816 */ 1817 void 1818 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1819 { 1820 struct pgrp *pgrp; 1821 1822 if (pgid != 0) { 1823 sx_slock(&proctree_lock); 1824 pgrp = pgfind(pgid); 1825 sx_sunlock(&proctree_lock); 1826 if (pgrp != NULL) { 1827 pgsignal(pgrp, sig, 0, ksi); 1828 PGRP_UNLOCK(pgrp); 1829 } 1830 } 1831 } 1832 1833 /* 1834 * Send a signal to a process group. If checktty is 1, 1835 * limit to members which have a controlling terminal. 1836 */ 1837 void 1838 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1839 { 1840 struct proc *p; 1841 1842 if (pgrp) { 1843 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1844 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1845 PROC_LOCK(p); 1846 if (p->p_state == PRS_NORMAL && 1847 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1848 pksignal(p, sig, ksi); 1849 PROC_UNLOCK(p); 1850 } 1851 } 1852 } 1853 1854 /* 1855 * Send a signal caused by a trap to the current thread. If it will be 1856 * caught immediately, deliver it with correct code. Otherwise, post it 1857 * normally. 1858 */ 1859 void 1860 trapsignal(struct thread *td, ksiginfo_t *ksi) 1861 { 1862 struct sigacts *ps; 1863 sigset_t mask; 1864 struct proc *p; 1865 int sig; 1866 int code; 1867 1868 p = td->td_proc; 1869 sig = ksi->ksi_signo; 1870 code = ksi->ksi_code; 1871 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1872 1873 PROC_LOCK(p); 1874 ps = p->p_sigacts; 1875 mtx_lock(&ps->ps_mtx); 1876 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1877 !SIGISMEMBER(td->td_sigmask, sig)) { 1878 td->td_ru.ru_nsignals++; 1879 #ifdef KTRACE 1880 if (KTRPOINT(curthread, KTR_PSIG)) 1881 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1882 &td->td_sigmask, code); 1883 #endif 1884 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1885 ksi, &td->td_sigmask); 1886 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1887 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1888 SIGADDSET(mask, sig); 1889 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1890 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1891 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1892 /* 1893 * See kern_sigaction() for origin of this code. 1894 */ 1895 SIGDELSET(ps->ps_sigcatch, sig); 1896 if (sig != SIGCONT && 1897 sigprop(sig) & SA_IGNORE) 1898 SIGADDSET(ps->ps_sigignore, sig); 1899 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1900 } 1901 mtx_unlock(&ps->ps_mtx); 1902 } else { 1903 /* 1904 * Avoid a possible infinite loop if the thread 1905 * masking the signal or process is ignoring the 1906 * signal. 1907 */ 1908 if (kern_forcesigexit && 1909 (SIGISMEMBER(td->td_sigmask, sig) || 1910 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1911 SIGDELSET(td->td_sigmask, sig); 1912 SIGDELSET(ps->ps_sigcatch, sig); 1913 SIGDELSET(ps->ps_sigignore, sig); 1914 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1915 } 1916 mtx_unlock(&ps->ps_mtx); 1917 p->p_code = code; /* XXX for core dump/debugger */ 1918 p->p_sig = sig; /* XXX to verify code */ 1919 tdsendsignal(p, td, sig, ksi); 1920 } 1921 PROC_UNLOCK(p); 1922 } 1923 1924 static struct thread * 1925 sigtd(struct proc *p, int sig, int prop) 1926 { 1927 struct thread *td, *signal_td; 1928 1929 PROC_LOCK_ASSERT(p, MA_OWNED); 1930 1931 /* 1932 * Check if current thread can handle the signal without 1933 * switching context to another thread. 1934 */ 1935 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1936 return (curthread); 1937 signal_td = NULL; 1938 FOREACH_THREAD_IN_PROC(p, td) { 1939 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1940 signal_td = td; 1941 break; 1942 } 1943 } 1944 if (signal_td == NULL) 1945 signal_td = FIRST_THREAD_IN_PROC(p); 1946 return (signal_td); 1947 } 1948 1949 /* 1950 * Send the signal to the process. If the signal has an action, the action 1951 * is usually performed by the target process rather than the caller; we add 1952 * the signal to the set of pending signals for the process. 1953 * 1954 * Exceptions: 1955 * o When a stop signal is sent to a sleeping process that takes the 1956 * default action, the process is stopped without awakening it. 1957 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1958 * regardless of the signal action (eg, blocked or ignored). 1959 * 1960 * Other ignored signals are discarded immediately. 1961 * 1962 * NB: This function may be entered from the debugger via the "kill" DDB 1963 * command. There is little that can be done to mitigate the possibly messy 1964 * side effects of this unwise possibility. 1965 */ 1966 void 1967 kern_psignal(struct proc *p, int sig) 1968 { 1969 ksiginfo_t ksi; 1970 1971 ksiginfo_init(&ksi); 1972 ksi.ksi_signo = sig; 1973 ksi.ksi_code = SI_KERNEL; 1974 (void) tdsendsignal(p, NULL, sig, &ksi); 1975 } 1976 1977 int 1978 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1979 { 1980 1981 return (tdsendsignal(p, NULL, sig, ksi)); 1982 } 1983 1984 /* Utility function for finding a thread to send signal event to. */ 1985 int 1986 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1987 { 1988 struct thread *td; 1989 1990 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1991 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 1992 if (td == NULL) 1993 return (ESRCH); 1994 *ttd = td; 1995 } else { 1996 *ttd = NULL; 1997 PROC_LOCK(p); 1998 } 1999 return (0); 2000 } 2001 2002 void 2003 tdsignal(struct thread *td, int sig) 2004 { 2005 ksiginfo_t ksi; 2006 2007 ksiginfo_init(&ksi); 2008 ksi.ksi_signo = sig; 2009 ksi.ksi_code = SI_KERNEL; 2010 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2011 } 2012 2013 void 2014 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2015 { 2016 2017 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2018 } 2019 2020 int 2021 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2022 { 2023 sig_t action; 2024 sigqueue_t *sigqueue; 2025 int prop; 2026 struct sigacts *ps; 2027 int intrval; 2028 int ret = 0; 2029 int wakeup_swapper; 2030 2031 MPASS(td == NULL || p == td->td_proc); 2032 PROC_LOCK_ASSERT(p, MA_OWNED); 2033 2034 if (!_SIG_VALID(sig)) 2035 panic("%s(): invalid signal %d", __func__, sig); 2036 2037 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2038 2039 /* 2040 * IEEE Std 1003.1-2001: return success when killing a zombie. 2041 */ 2042 if (p->p_state == PRS_ZOMBIE) { 2043 if (ksi && (ksi->ksi_flags & KSI_INS)) 2044 ksiginfo_tryfree(ksi); 2045 return (ret); 2046 } 2047 2048 ps = p->p_sigacts; 2049 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2050 prop = sigprop(sig); 2051 2052 if (td == NULL) { 2053 td = sigtd(p, sig, prop); 2054 sigqueue = &p->p_sigqueue; 2055 } else 2056 sigqueue = &td->td_sigqueue; 2057 2058 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 ); 2059 2060 /* 2061 * If the signal is being ignored, 2062 * then we forget about it immediately. 2063 * (Note: we don't set SIGCONT in ps_sigignore, 2064 * and if it is set to SIG_IGN, 2065 * action will be SIG_DFL here.) 2066 */ 2067 mtx_lock(&ps->ps_mtx); 2068 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2069 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 ); 2070 2071 mtx_unlock(&ps->ps_mtx); 2072 if (ksi && (ksi->ksi_flags & KSI_INS)) 2073 ksiginfo_tryfree(ksi); 2074 return (ret); 2075 } 2076 if (SIGISMEMBER(td->td_sigmask, sig)) 2077 action = SIG_HOLD; 2078 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2079 action = SIG_CATCH; 2080 else 2081 action = SIG_DFL; 2082 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2083 intrval = EINTR; 2084 else 2085 intrval = ERESTART; 2086 mtx_unlock(&ps->ps_mtx); 2087 2088 if (prop & SA_CONT) 2089 sigqueue_delete_stopmask_proc(p); 2090 else if (prop & SA_STOP) { 2091 /* 2092 * If sending a tty stop signal to a member of an orphaned 2093 * process group, discard the signal here if the action 2094 * is default; don't stop the process below if sleeping, 2095 * and don't clear any pending SIGCONT. 2096 */ 2097 if ((prop & SA_TTYSTOP) && 2098 (p->p_pgrp->pg_jobc == 0) && 2099 (action == SIG_DFL)) { 2100 if (ksi && (ksi->ksi_flags & KSI_INS)) 2101 ksiginfo_tryfree(ksi); 2102 return (ret); 2103 } 2104 sigqueue_delete_proc(p, SIGCONT); 2105 if (p->p_flag & P_CONTINUED) { 2106 p->p_flag &= ~P_CONTINUED; 2107 PROC_LOCK(p->p_pptr); 2108 sigqueue_take(p->p_ksi); 2109 PROC_UNLOCK(p->p_pptr); 2110 } 2111 } 2112 2113 ret = sigqueue_add(sigqueue, sig, ksi); 2114 if (ret != 0) 2115 return (ret); 2116 signotify(td); 2117 /* 2118 * Defer further processing for signals which are held, 2119 * except that stopped processes must be continued by SIGCONT. 2120 */ 2121 if (action == SIG_HOLD && 2122 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2123 return (ret); 2124 /* 2125 * SIGKILL: Remove procfs STOPEVENTs. 2126 */ 2127 if (sig == SIGKILL) { 2128 /* from procfs_ioctl.c: PIOCBIC */ 2129 p->p_stops = 0; 2130 /* from procfs_ioctl.c: PIOCCONT */ 2131 p->p_step = 0; 2132 wakeup(&p->p_step); 2133 } 2134 /* 2135 * Some signals have a process-wide effect and a per-thread 2136 * component. Most processing occurs when the process next 2137 * tries to cross the user boundary, however there are some 2138 * times when processing needs to be done immediately, such as 2139 * waking up threads so that they can cross the user boundary. 2140 * We try to do the per-process part here. 2141 */ 2142 if (P_SHOULDSTOP(p)) { 2143 KASSERT(!(p->p_flag & P_WEXIT), 2144 ("signal to stopped but exiting process")); 2145 if (sig == SIGKILL) { 2146 /* 2147 * If traced process is already stopped, 2148 * then no further action is necessary. 2149 */ 2150 if (p->p_flag & P_TRACED) 2151 goto out; 2152 /* 2153 * SIGKILL sets process running. 2154 * It will die elsewhere. 2155 * All threads must be restarted. 2156 */ 2157 p->p_flag &= ~P_STOPPED_SIG; 2158 goto runfast; 2159 } 2160 2161 if (prop & SA_CONT) { 2162 /* 2163 * If traced process is already stopped, 2164 * then no further action is necessary. 2165 */ 2166 if (p->p_flag & P_TRACED) 2167 goto out; 2168 /* 2169 * If SIGCONT is default (or ignored), we continue the 2170 * process but don't leave the signal in sigqueue as 2171 * it has no further action. If SIGCONT is held, we 2172 * continue the process and leave the signal in 2173 * sigqueue. If the process catches SIGCONT, let it 2174 * handle the signal itself. If it isn't waiting on 2175 * an event, it goes back to run state. 2176 * Otherwise, process goes back to sleep state. 2177 */ 2178 p->p_flag &= ~P_STOPPED_SIG; 2179 PROC_SLOCK(p); 2180 if (p->p_numthreads == p->p_suspcount) { 2181 PROC_SUNLOCK(p); 2182 p->p_flag |= P_CONTINUED; 2183 p->p_xstat = SIGCONT; 2184 PROC_LOCK(p->p_pptr); 2185 childproc_continued(p); 2186 PROC_UNLOCK(p->p_pptr); 2187 PROC_SLOCK(p); 2188 } 2189 if (action == SIG_DFL) { 2190 thread_unsuspend(p); 2191 PROC_SUNLOCK(p); 2192 sigqueue_delete(sigqueue, sig); 2193 goto out; 2194 } 2195 if (action == SIG_CATCH) { 2196 /* 2197 * The process wants to catch it so it needs 2198 * to run at least one thread, but which one? 2199 */ 2200 PROC_SUNLOCK(p); 2201 goto runfast; 2202 } 2203 /* 2204 * The signal is not ignored or caught. 2205 */ 2206 thread_unsuspend(p); 2207 PROC_SUNLOCK(p); 2208 goto out; 2209 } 2210 2211 if (prop & SA_STOP) { 2212 /* 2213 * If traced process is already stopped, 2214 * then no further action is necessary. 2215 */ 2216 if (p->p_flag & P_TRACED) 2217 goto out; 2218 /* 2219 * Already stopped, don't need to stop again 2220 * (If we did the shell could get confused). 2221 * Just make sure the signal STOP bit set. 2222 */ 2223 p->p_flag |= P_STOPPED_SIG; 2224 sigqueue_delete(sigqueue, sig); 2225 goto out; 2226 } 2227 2228 /* 2229 * All other kinds of signals: 2230 * If a thread is sleeping interruptibly, simulate a 2231 * wakeup so that when it is continued it will be made 2232 * runnable and can look at the signal. However, don't make 2233 * the PROCESS runnable, leave it stopped. 2234 * It may run a bit until it hits a thread_suspend_check(). 2235 */ 2236 wakeup_swapper = 0; 2237 PROC_SLOCK(p); 2238 thread_lock(td); 2239 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2240 wakeup_swapper = sleepq_abort(td, intrval); 2241 thread_unlock(td); 2242 PROC_SUNLOCK(p); 2243 if (wakeup_swapper) 2244 kick_proc0(); 2245 goto out; 2246 /* 2247 * Mutexes are short lived. Threads waiting on them will 2248 * hit thread_suspend_check() soon. 2249 */ 2250 } else if (p->p_state == PRS_NORMAL) { 2251 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2252 tdsigwakeup(td, sig, action, intrval); 2253 goto out; 2254 } 2255 2256 MPASS(action == SIG_DFL); 2257 2258 if (prop & SA_STOP) { 2259 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2260 goto out; 2261 p->p_flag |= P_STOPPED_SIG; 2262 p->p_xstat = sig; 2263 PROC_SLOCK(p); 2264 sig_suspend_threads(td, p, 1); 2265 if (p->p_numthreads == p->p_suspcount) { 2266 /* 2267 * only thread sending signal to another 2268 * process can reach here, if thread is sending 2269 * signal to its process, because thread does 2270 * not suspend itself here, p_numthreads 2271 * should never be equal to p_suspcount. 2272 */ 2273 thread_stopped(p); 2274 PROC_SUNLOCK(p); 2275 sigqueue_delete_proc(p, p->p_xstat); 2276 } else 2277 PROC_SUNLOCK(p); 2278 goto out; 2279 } 2280 } else { 2281 /* Not in "NORMAL" state. discard the signal. */ 2282 sigqueue_delete(sigqueue, sig); 2283 goto out; 2284 } 2285 2286 /* 2287 * The process is not stopped so we need to apply the signal to all the 2288 * running threads. 2289 */ 2290 runfast: 2291 tdsigwakeup(td, sig, action, intrval); 2292 PROC_SLOCK(p); 2293 thread_unsuspend(p); 2294 PROC_SUNLOCK(p); 2295 out: 2296 /* If we jump here, proc slock should not be owned. */ 2297 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2298 return (ret); 2299 } 2300 2301 /* 2302 * The force of a signal has been directed against a single 2303 * thread. We need to see what we can do about knocking it 2304 * out of any sleep it may be in etc. 2305 */ 2306 static void 2307 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2308 { 2309 struct proc *p = td->td_proc; 2310 register int prop; 2311 int wakeup_swapper; 2312 2313 wakeup_swapper = 0; 2314 PROC_LOCK_ASSERT(p, MA_OWNED); 2315 prop = sigprop(sig); 2316 2317 PROC_SLOCK(p); 2318 thread_lock(td); 2319 /* 2320 * Bring the priority of a thread up if we want it to get 2321 * killed in this lifetime. 2322 */ 2323 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2324 sched_prio(td, PUSER); 2325 if (TD_ON_SLEEPQ(td)) { 2326 /* 2327 * If thread is sleeping uninterruptibly 2328 * we can't interrupt the sleep... the signal will 2329 * be noticed when the process returns through 2330 * trap() or syscall(). 2331 */ 2332 if ((td->td_flags & TDF_SINTR) == 0) 2333 goto out; 2334 /* 2335 * If SIGCONT is default (or ignored) and process is 2336 * asleep, we are finished; the process should not 2337 * be awakened. 2338 */ 2339 if ((prop & SA_CONT) && action == SIG_DFL) { 2340 thread_unlock(td); 2341 PROC_SUNLOCK(p); 2342 sigqueue_delete(&p->p_sigqueue, sig); 2343 /* 2344 * It may be on either list in this state. 2345 * Remove from both for now. 2346 */ 2347 sigqueue_delete(&td->td_sigqueue, sig); 2348 return; 2349 } 2350 2351 /* 2352 * Don't awaken a sleeping thread for SIGSTOP if the 2353 * STOP signal is deferred. 2354 */ 2355 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2356 goto out; 2357 2358 /* 2359 * Give low priority threads a better chance to run. 2360 */ 2361 if (td->td_priority > PUSER) 2362 sched_prio(td, PUSER); 2363 2364 wakeup_swapper = sleepq_abort(td, intrval); 2365 } else { 2366 /* 2367 * Other states do nothing with the signal immediately, 2368 * other than kicking ourselves if we are running. 2369 * It will either never be noticed, or noticed very soon. 2370 */ 2371 #ifdef SMP 2372 if (TD_IS_RUNNING(td) && td != curthread) 2373 forward_signal(td); 2374 #endif 2375 } 2376 out: 2377 PROC_SUNLOCK(p); 2378 thread_unlock(td); 2379 if (wakeup_swapper) 2380 kick_proc0(); 2381 } 2382 2383 static void 2384 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2385 { 2386 struct thread *td2; 2387 2388 PROC_LOCK_ASSERT(p, MA_OWNED); 2389 PROC_SLOCK_ASSERT(p, MA_OWNED); 2390 2391 FOREACH_THREAD_IN_PROC(p, td2) { 2392 thread_lock(td2); 2393 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2394 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2395 (td2->td_flags & TDF_SINTR)) { 2396 if (td2->td_flags & TDF_SBDRY) { 2397 /* 2398 * Once a thread is asleep with 2399 * TDF_SBDRY set, it should never 2400 * become suspended due to this check. 2401 */ 2402 KASSERT(!TD_IS_SUSPENDED(td2), 2403 ("thread with deferred stops suspended")); 2404 } else if (!TD_IS_SUSPENDED(td2)) { 2405 thread_suspend_one(td2); 2406 } 2407 } else if (!TD_IS_SUSPENDED(td2)) { 2408 if (sending || td != td2) 2409 td2->td_flags |= TDF_ASTPENDING; 2410 #ifdef SMP 2411 if (TD_IS_RUNNING(td2) && td2 != td) 2412 forward_signal(td2); 2413 #endif 2414 } 2415 thread_unlock(td2); 2416 } 2417 } 2418 2419 int 2420 ptracestop(struct thread *td, int sig) 2421 { 2422 struct proc *p = td->td_proc; 2423 2424 PROC_LOCK_ASSERT(p, MA_OWNED); 2425 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2426 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2427 &p->p_mtx.lock_object, "Stopping for traced signal"); 2428 2429 td->td_dbgflags |= TDB_XSIG; 2430 td->td_xsig = sig; 2431 PROC_SLOCK(p); 2432 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2433 if (p->p_flag & P_SINGLE_EXIT) { 2434 td->td_dbgflags &= ~TDB_XSIG; 2435 PROC_SUNLOCK(p); 2436 return (sig); 2437 } 2438 /* 2439 * Just make wait() to work, the last stopped thread 2440 * will win. 2441 */ 2442 p->p_xstat = sig; 2443 p->p_xthread = td; 2444 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2445 sig_suspend_threads(td, p, 0); 2446 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2447 td->td_dbgflags &= ~TDB_STOPATFORK; 2448 cv_broadcast(&p->p_dbgwait); 2449 } 2450 stopme: 2451 thread_suspend_switch(td); 2452 if (p->p_xthread == td) 2453 p->p_xthread = NULL; 2454 if (!(p->p_flag & P_TRACED)) 2455 break; 2456 if (td->td_dbgflags & TDB_SUSPEND) { 2457 if (p->p_flag & P_SINGLE_EXIT) 2458 break; 2459 goto stopme; 2460 } 2461 } 2462 PROC_SUNLOCK(p); 2463 return (td->td_xsig); 2464 } 2465 2466 static void 2467 reschedule_signals(struct proc *p, sigset_t block, int flags) 2468 { 2469 struct sigacts *ps; 2470 struct thread *td; 2471 int sig; 2472 2473 PROC_LOCK_ASSERT(p, MA_OWNED); 2474 if (SIGISEMPTY(p->p_siglist)) 2475 return; 2476 ps = p->p_sigacts; 2477 SIGSETAND(block, p->p_siglist); 2478 while ((sig = sig_ffs(&block)) != 0) { 2479 SIGDELSET(block, sig); 2480 td = sigtd(p, sig, 0); 2481 signotify(td); 2482 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2483 mtx_lock(&ps->ps_mtx); 2484 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2485 tdsigwakeup(td, sig, SIG_CATCH, 2486 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2487 ERESTART)); 2488 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2489 mtx_unlock(&ps->ps_mtx); 2490 } 2491 } 2492 2493 void 2494 tdsigcleanup(struct thread *td) 2495 { 2496 struct proc *p; 2497 sigset_t unblocked; 2498 2499 p = td->td_proc; 2500 PROC_LOCK_ASSERT(p, MA_OWNED); 2501 2502 sigqueue_flush(&td->td_sigqueue); 2503 if (p->p_numthreads == 1) 2504 return; 2505 2506 /* 2507 * Since we cannot handle signals, notify signal post code 2508 * about this by filling the sigmask. 2509 * 2510 * Also, if needed, wake up thread(s) that do not block the 2511 * same signals as the exiting thread, since the thread might 2512 * have been selected for delivery and woken up. 2513 */ 2514 SIGFILLSET(unblocked); 2515 SIGSETNAND(unblocked, td->td_sigmask); 2516 SIGFILLSET(td->td_sigmask); 2517 reschedule_signals(p, unblocked, 0); 2518 2519 } 2520 2521 /* 2522 * Defer the delivery of SIGSTOP for the current thread. Returns true 2523 * if stops were deferred and false if they were already deferred. 2524 */ 2525 int 2526 sigdeferstop(void) 2527 { 2528 struct thread *td; 2529 2530 td = curthread; 2531 if (td->td_flags & TDF_SBDRY) 2532 return (0); 2533 thread_lock(td); 2534 td->td_flags |= TDF_SBDRY; 2535 thread_unlock(td); 2536 return (1); 2537 } 2538 2539 /* 2540 * Permit the delivery of SIGSTOP for the current thread. This does 2541 * not immediately suspend if a stop was posted. Instead, the thread 2542 * will suspend either via ast() or a subsequent interruptible sleep. 2543 */ 2544 void 2545 sigallowstop() 2546 { 2547 struct thread *td; 2548 2549 td = curthread; 2550 thread_lock(td); 2551 td->td_flags &= ~TDF_SBDRY; 2552 thread_unlock(td); 2553 } 2554 2555 /* 2556 * If the current process has received a signal (should be caught or cause 2557 * termination, should interrupt current syscall), return the signal number. 2558 * Stop signals with default action are processed immediately, then cleared; 2559 * they aren't returned. This is checked after each entry to the system for 2560 * a syscall or trap (though this can usually be done without calling issignal 2561 * by checking the pending signal masks in cursig.) The normal call 2562 * sequence is 2563 * 2564 * while (sig = cursig(curthread)) 2565 * postsig(sig); 2566 */ 2567 static int 2568 issignal(struct thread *td) 2569 { 2570 struct proc *p; 2571 struct sigacts *ps; 2572 struct sigqueue *queue; 2573 sigset_t sigpending; 2574 int sig, prop, newsig; 2575 2576 p = td->td_proc; 2577 ps = p->p_sigacts; 2578 mtx_assert(&ps->ps_mtx, MA_OWNED); 2579 PROC_LOCK_ASSERT(p, MA_OWNED); 2580 for (;;) { 2581 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2582 2583 sigpending = td->td_sigqueue.sq_signals; 2584 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2585 SIGSETNAND(sigpending, td->td_sigmask); 2586 2587 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2588 SIG_STOPSIGMASK(sigpending); 2589 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2590 return (0); 2591 sig = sig_ffs(&sigpending); 2592 2593 if (p->p_stops & S_SIG) { 2594 mtx_unlock(&ps->ps_mtx); 2595 stopevent(p, S_SIG, sig); 2596 mtx_lock(&ps->ps_mtx); 2597 } 2598 2599 /* 2600 * We should see pending but ignored signals 2601 * only if P_TRACED was on when they were posted. 2602 */ 2603 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2604 sigqueue_delete(&td->td_sigqueue, sig); 2605 sigqueue_delete(&p->p_sigqueue, sig); 2606 continue; 2607 } 2608 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2609 /* 2610 * If traced, always stop. 2611 * Remove old signal from queue before the stop. 2612 * XXX shrug off debugger, it causes siginfo to 2613 * be thrown away. 2614 */ 2615 queue = &td->td_sigqueue; 2616 td->td_dbgksi.ksi_signo = 0; 2617 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2618 queue = &p->p_sigqueue; 2619 sigqueue_get(queue, sig, &td->td_dbgksi); 2620 } 2621 2622 mtx_unlock(&ps->ps_mtx); 2623 newsig = ptracestop(td, sig); 2624 mtx_lock(&ps->ps_mtx); 2625 2626 if (sig != newsig) { 2627 2628 /* 2629 * If parent wants us to take the signal, 2630 * then it will leave it in p->p_xstat; 2631 * otherwise we just look for signals again. 2632 */ 2633 if (newsig == 0) 2634 continue; 2635 sig = newsig; 2636 2637 /* 2638 * Put the new signal into td_sigqueue. If the 2639 * signal is being masked, look for other 2640 * signals. 2641 */ 2642 sigqueue_add(queue, sig, NULL); 2643 if (SIGISMEMBER(td->td_sigmask, sig)) 2644 continue; 2645 signotify(td); 2646 } else { 2647 if (td->td_dbgksi.ksi_signo != 0) { 2648 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2649 if (sigqueue_add(&td->td_sigqueue, sig, 2650 &td->td_dbgksi) != 0) 2651 td->td_dbgksi.ksi_signo = 0; 2652 } 2653 if (td->td_dbgksi.ksi_signo == 0) 2654 sigqueue_add(&td->td_sigqueue, sig, 2655 NULL); 2656 } 2657 2658 /* 2659 * If the traced bit got turned off, go back up 2660 * to the top to rescan signals. This ensures 2661 * that p_sig* and p_sigact are consistent. 2662 */ 2663 if ((p->p_flag & P_TRACED) == 0) 2664 continue; 2665 } 2666 2667 prop = sigprop(sig); 2668 2669 /* 2670 * Decide whether the signal should be returned. 2671 * Return the signal's number, or fall through 2672 * to clear it from the pending mask. 2673 */ 2674 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2675 2676 case (intptr_t)SIG_DFL: 2677 /* 2678 * Don't take default actions on system processes. 2679 */ 2680 if (p->p_pid <= 1) { 2681 #ifdef DIAGNOSTIC 2682 /* 2683 * Are you sure you want to ignore SIGSEGV 2684 * in init? XXX 2685 */ 2686 printf("Process (pid %lu) got signal %d\n", 2687 (u_long)p->p_pid, sig); 2688 #endif 2689 break; /* == ignore */ 2690 } 2691 /* 2692 * If there is a pending stop signal to process 2693 * with default action, stop here, 2694 * then clear the signal. However, 2695 * if process is member of an orphaned 2696 * process group, ignore tty stop signals. 2697 */ 2698 if (prop & SA_STOP) { 2699 if (p->p_flag & (P_TRACED|P_WEXIT) || 2700 (p->p_pgrp->pg_jobc == 0 && 2701 prop & SA_TTYSTOP)) 2702 break; /* == ignore */ 2703 mtx_unlock(&ps->ps_mtx); 2704 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2705 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2706 p->p_flag |= P_STOPPED_SIG; 2707 p->p_xstat = sig; 2708 PROC_SLOCK(p); 2709 sig_suspend_threads(td, p, 0); 2710 thread_suspend_switch(td); 2711 PROC_SUNLOCK(p); 2712 mtx_lock(&ps->ps_mtx); 2713 break; 2714 } else if (prop & SA_IGNORE) { 2715 /* 2716 * Except for SIGCONT, shouldn't get here. 2717 * Default action is to ignore; drop it. 2718 */ 2719 break; /* == ignore */ 2720 } else 2721 return (sig); 2722 /*NOTREACHED*/ 2723 2724 case (intptr_t)SIG_IGN: 2725 /* 2726 * Masking above should prevent us ever trying 2727 * to take action on an ignored signal other 2728 * than SIGCONT, unless process is traced. 2729 */ 2730 if ((prop & SA_CONT) == 0 && 2731 (p->p_flag & P_TRACED) == 0) 2732 printf("issignal\n"); 2733 break; /* == ignore */ 2734 2735 default: 2736 /* 2737 * This signal has an action, let 2738 * postsig() process it. 2739 */ 2740 return (sig); 2741 } 2742 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2743 sigqueue_delete(&p->p_sigqueue, sig); 2744 } 2745 /* NOTREACHED */ 2746 } 2747 2748 void 2749 thread_stopped(struct proc *p) 2750 { 2751 int n; 2752 2753 PROC_LOCK_ASSERT(p, MA_OWNED); 2754 PROC_SLOCK_ASSERT(p, MA_OWNED); 2755 n = p->p_suspcount; 2756 if (p == curproc) 2757 n++; 2758 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2759 PROC_SUNLOCK(p); 2760 p->p_flag &= ~P_WAITED; 2761 PROC_LOCK(p->p_pptr); 2762 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2763 CLD_TRAPPED : CLD_STOPPED); 2764 PROC_UNLOCK(p->p_pptr); 2765 PROC_SLOCK(p); 2766 } 2767 } 2768 2769 /* 2770 * Take the action for the specified signal 2771 * from the current set of pending signals. 2772 */ 2773 int 2774 postsig(sig) 2775 register int sig; 2776 { 2777 struct thread *td = curthread; 2778 register struct proc *p = td->td_proc; 2779 struct sigacts *ps; 2780 sig_t action; 2781 ksiginfo_t ksi; 2782 sigset_t returnmask, mask; 2783 2784 KASSERT(sig != 0, ("postsig")); 2785 2786 PROC_LOCK_ASSERT(p, MA_OWNED); 2787 ps = p->p_sigacts; 2788 mtx_assert(&ps->ps_mtx, MA_OWNED); 2789 ksiginfo_init(&ksi); 2790 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2791 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2792 return (0); 2793 ksi.ksi_signo = sig; 2794 if (ksi.ksi_code == SI_TIMER) 2795 itimer_accept(p, ksi.ksi_timerid, &ksi); 2796 action = ps->ps_sigact[_SIG_IDX(sig)]; 2797 #ifdef KTRACE 2798 if (KTRPOINT(td, KTR_PSIG)) 2799 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2800 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2801 #endif 2802 if (p->p_stops & S_SIG) { 2803 mtx_unlock(&ps->ps_mtx); 2804 stopevent(p, S_SIG, sig); 2805 mtx_lock(&ps->ps_mtx); 2806 } 2807 2808 if (action == SIG_DFL) { 2809 /* 2810 * Default action, where the default is to kill 2811 * the process. (Other cases were ignored above.) 2812 */ 2813 mtx_unlock(&ps->ps_mtx); 2814 sigexit(td, sig); 2815 /* NOTREACHED */ 2816 } else { 2817 /* 2818 * If we get here, the signal must be caught. 2819 */ 2820 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2821 ("postsig action")); 2822 /* 2823 * Set the new mask value and also defer further 2824 * occurrences of this signal. 2825 * 2826 * Special case: user has done a sigsuspend. Here the 2827 * current mask is not of interest, but rather the 2828 * mask from before the sigsuspend is what we want 2829 * restored after the signal processing is completed. 2830 */ 2831 if (td->td_pflags & TDP_OLDMASK) { 2832 returnmask = td->td_oldsigmask; 2833 td->td_pflags &= ~TDP_OLDMASK; 2834 } else 2835 returnmask = td->td_sigmask; 2836 2837 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2838 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2839 SIGADDSET(mask, sig); 2840 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2841 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2842 2843 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2844 /* 2845 * See kern_sigaction() for origin of this code. 2846 */ 2847 SIGDELSET(ps->ps_sigcatch, sig); 2848 if (sig != SIGCONT && 2849 sigprop(sig) & SA_IGNORE) 2850 SIGADDSET(ps->ps_sigignore, sig); 2851 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2852 } 2853 td->td_ru.ru_nsignals++; 2854 if (p->p_sig == sig) { 2855 p->p_code = 0; 2856 p->p_sig = 0; 2857 } 2858 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2859 } 2860 return (1); 2861 } 2862 2863 /* 2864 * Kill the current process for stated reason. 2865 */ 2866 void 2867 killproc(p, why) 2868 struct proc *p; 2869 char *why; 2870 { 2871 2872 PROC_LOCK_ASSERT(p, MA_OWNED); 2873 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2874 p->p_comm); 2875 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2876 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2877 p->p_flag |= P_WKILLED; 2878 kern_psignal(p, SIGKILL); 2879 } 2880 2881 /* 2882 * Force the current process to exit with the specified signal, dumping core 2883 * if appropriate. We bypass the normal tests for masked and caught signals, 2884 * allowing unrecoverable failures to terminate the process without changing 2885 * signal state. Mark the accounting record with the signal termination. 2886 * If dumping core, save the signal number for the debugger. Calls exit and 2887 * does not return. 2888 */ 2889 void 2890 sigexit(td, sig) 2891 struct thread *td; 2892 int sig; 2893 { 2894 struct proc *p = td->td_proc; 2895 2896 PROC_LOCK_ASSERT(p, MA_OWNED); 2897 p->p_acflag |= AXSIG; 2898 /* 2899 * We must be single-threading to generate a core dump. This 2900 * ensures that the registers in the core file are up-to-date. 2901 * Also, the ELF dump handler assumes that the thread list doesn't 2902 * change out from under it. 2903 * 2904 * XXX If another thread attempts to single-thread before us 2905 * (e.g. via fork()), we won't get a dump at all. 2906 */ 2907 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2908 p->p_sig = sig; 2909 /* 2910 * Log signals which would cause core dumps 2911 * (Log as LOG_INFO to appease those who don't want 2912 * these messages.) 2913 * XXX : Todo, as well as euid, write out ruid too 2914 * Note that coredump() drops proc lock. 2915 */ 2916 if (coredump(td) == 0) 2917 sig |= WCOREFLAG; 2918 if (kern_logsigexit) 2919 log(LOG_INFO, 2920 "pid %d (%s), uid %d: exited on signal %d%s\n", 2921 p->p_pid, p->p_comm, 2922 td->td_ucred ? td->td_ucred->cr_uid : -1, 2923 sig &~ WCOREFLAG, 2924 sig & WCOREFLAG ? " (core dumped)" : ""); 2925 } else 2926 PROC_UNLOCK(p); 2927 exit1(td, W_EXITCODE(0, sig)); 2928 /* NOTREACHED */ 2929 } 2930 2931 /* 2932 * Send queued SIGCHLD to parent when child process's state 2933 * is changed. 2934 */ 2935 static void 2936 sigparent(struct proc *p, int reason, int status) 2937 { 2938 PROC_LOCK_ASSERT(p, MA_OWNED); 2939 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2940 2941 if (p->p_ksi != NULL) { 2942 p->p_ksi->ksi_signo = SIGCHLD; 2943 p->p_ksi->ksi_code = reason; 2944 p->p_ksi->ksi_status = status; 2945 p->p_ksi->ksi_pid = p->p_pid; 2946 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2947 if (KSI_ONQ(p->p_ksi)) 2948 return; 2949 } 2950 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2951 } 2952 2953 static void 2954 childproc_jobstate(struct proc *p, int reason, int sig) 2955 { 2956 struct sigacts *ps; 2957 2958 PROC_LOCK_ASSERT(p, MA_OWNED); 2959 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2960 2961 /* 2962 * Wake up parent sleeping in kern_wait(), also send 2963 * SIGCHLD to parent, but SIGCHLD does not guarantee 2964 * that parent will awake, because parent may masked 2965 * the signal. 2966 */ 2967 p->p_pptr->p_flag |= P_STATCHILD; 2968 wakeup(p->p_pptr); 2969 2970 ps = p->p_pptr->p_sigacts; 2971 mtx_lock(&ps->ps_mtx); 2972 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2973 mtx_unlock(&ps->ps_mtx); 2974 sigparent(p, reason, sig); 2975 } else 2976 mtx_unlock(&ps->ps_mtx); 2977 } 2978 2979 void 2980 childproc_stopped(struct proc *p, int reason) 2981 { 2982 /* p_xstat is a plain signal number, not a full wait() status here. */ 2983 childproc_jobstate(p, reason, p->p_xstat); 2984 } 2985 2986 void 2987 childproc_continued(struct proc *p) 2988 { 2989 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2990 } 2991 2992 void 2993 childproc_exited(struct proc *p) 2994 { 2995 int reason; 2996 int xstat = p->p_xstat; /* convert to int */ 2997 int status; 2998 2999 if (WCOREDUMP(xstat)) 3000 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3001 else if (WIFSIGNALED(xstat)) 3002 reason = CLD_KILLED, status = WTERMSIG(xstat); 3003 else 3004 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3005 /* 3006 * XXX avoid calling wakeup(p->p_pptr), the work is 3007 * done in exit1(). 3008 */ 3009 sigparent(p, reason, status); 3010 } 3011 3012 /* 3013 * We only have 1 character for the core count in the format 3014 * string, so the range will be 0-9 3015 */ 3016 #define MAX_NUM_CORES 10 3017 static int num_cores = 5; 3018 3019 static int 3020 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3021 { 3022 int error; 3023 int new_val; 3024 3025 new_val = num_cores; 3026 error = sysctl_handle_int(oidp, &new_val, 0, req); 3027 if (error != 0 || req->newptr == NULL) 3028 return (error); 3029 if (new_val > MAX_NUM_CORES) 3030 new_val = MAX_NUM_CORES; 3031 if (new_val < 0) 3032 new_val = 0; 3033 num_cores = new_val; 3034 return (0); 3035 } 3036 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3037 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3038 3039 #if defined(COMPRESS_USER_CORES) 3040 int compress_user_cores = 1; 3041 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3042 &compress_user_cores, 0, "Compression of user corefiles"); 3043 3044 int compress_user_cores_gzlevel = -1; /* default level */ 3045 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3046 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3047 3048 #define GZ_SUFFIX ".gz" 3049 #define GZ_SUFFIX_LEN 3 3050 #endif 3051 3052 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3053 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RWTUN, corefilename, 3054 sizeof(corefilename), "Process corefile name format string"); 3055 3056 /* 3057 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3058 * Expand the name described in corefilename, using name, uid, and pid 3059 * and open/create core file. 3060 * corefilename is a printf-like string, with three format specifiers: 3061 * %N name of process ("name") 3062 * %P process id (pid) 3063 * %U user id (uid) 3064 * For example, "%N.core" is the default; they can be disabled completely 3065 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3066 * This is controlled by the sysctl variable kern.corefile (see above). 3067 */ 3068 static int 3069 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3070 int compress, struct vnode **vpp, char **namep) 3071 { 3072 struct nameidata nd; 3073 struct sbuf sb; 3074 const char *format; 3075 char *hostname, *name; 3076 int indexpos, i, error, cmode, flags, oflags; 3077 3078 hostname = NULL; 3079 format = corefilename; 3080 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3081 indexpos = -1; 3082 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3083 for (i = 0; format[i] != '\0'; i++) { 3084 switch (format[i]) { 3085 case '%': /* Format character */ 3086 i++; 3087 switch (format[i]) { 3088 case '%': 3089 sbuf_putc(&sb, '%'); 3090 break; 3091 case 'H': /* hostname */ 3092 if (hostname == NULL) { 3093 hostname = malloc(MAXHOSTNAMELEN, 3094 M_TEMP, M_WAITOK); 3095 } 3096 getcredhostname(td->td_ucred, hostname, 3097 MAXHOSTNAMELEN); 3098 sbuf_printf(&sb, "%s", hostname); 3099 break; 3100 case 'I': /* autoincrementing index */ 3101 sbuf_printf(&sb, "0"); 3102 indexpos = sbuf_len(&sb) - 1; 3103 break; 3104 case 'N': /* process name */ 3105 sbuf_printf(&sb, "%s", comm); 3106 break; 3107 case 'P': /* process id */ 3108 sbuf_printf(&sb, "%u", pid); 3109 break; 3110 case 'U': /* user id */ 3111 sbuf_printf(&sb, "%u", uid); 3112 break; 3113 default: 3114 log(LOG_ERR, 3115 "Unknown format character %c in " 3116 "corename `%s'\n", format[i], format); 3117 break; 3118 } 3119 break; 3120 default: 3121 sbuf_putc(&sb, format[i]); 3122 break; 3123 } 3124 } 3125 free(hostname, M_TEMP); 3126 #ifdef COMPRESS_USER_CORES 3127 if (compress) 3128 sbuf_printf(&sb, GZ_SUFFIX); 3129 #endif 3130 if (sbuf_error(&sb) != 0) { 3131 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3132 "long\n", (long)pid, comm, (u_long)uid); 3133 sbuf_delete(&sb); 3134 free(name, M_TEMP); 3135 return (ENOMEM); 3136 } 3137 sbuf_finish(&sb); 3138 sbuf_delete(&sb); 3139 3140 cmode = S_IRUSR | S_IWUSR; 3141 oflags = VN_OPEN_NOAUDIT | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3142 3143 /* 3144 * If the core format has a %I in it, then we need to check 3145 * for existing corefiles before returning a name. 3146 * To do this we iterate over 0..num_cores to find a 3147 * non-existing core file name to use. 3148 */ 3149 if (indexpos != -1) { 3150 for (i = 0; i < num_cores; i++) { 3151 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3152 name[indexpos] = '0' + i; 3153 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3154 error = vn_open_cred(&nd, &flags, cmode, oflags, 3155 td->td_ucred, NULL); 3156 if (error) { 3157 if (error == EEXIST) 3158 continue; 3159 log(LOG_ERR, 3160 "pid %d (%s), uid (%u): Path `%s' failed " 3161 "on initial open test, error = %d\n", 3162 pid, comm, uid, name, error); 3163 } 3164 goto out; 3165 } 3166 } 3167 3168 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3169 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3170 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3171 out: 3172 if (error) { 3173 #ifdef AUDIT 3174 audit_proc_coredump(td, name, error); 3175 #endif 3176 free(name, M_TEMP); 3177 return (error); 3178 } 3179 NDFREE(&nd, NDF_ONLY_PNBUF); 3180 *vpp = nd.ni_vp; 3181 *namep = name; 3182 return (0); 3183 } 3184 3185 /* 3186 * Dump a process' core. The main routine does some 3187 * policy checking, and creates the name of the coredump; 3188 * then it passes on a vnode and a size limit to the process-specific 3189 * coredump routine if there is one; if there _is not_ one, it returns 3190 * ENOSYS; otherwise it returns the error from the process-specific routine. 3191 */ 3192 3193 static int 3194 coredump(struct thread *td) 3195 { 3196 struct proc *p = td->td_proc; 3197 struct ucred *cred = td->td_ucred; 3198 struct vnode *vp; 3199 struct flock lf; 3200 struct vattr vattr; 3201 int error, error1, locked; 3202 struct mount *mp; 3203 char *name; /* name of corefile */ 3204 off_t limit; 3205 int compress; 3206 3207 #ifdef COMPRESS_USER_CORES 3208 compress = compress_user_cores; 3209 #else 3210 compress = 0; 3211 #endif 3212 PROC_LOCK_ASSERT(p, MA_OWNED); 3213 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3214 _STOPEVENT(p, S_CORE, 0); 3215 3216 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) { 3217 PROC_UNLOCK(p); 3218 return (EFAULT); 3219 } 3220 3221 /* 3222 * Note that the bulk of limit checking is done after 3223 * the corefile is created. The exception is if the limit 3224 * for corefiles is 0, in which case we don't bother 3225 * creating the corefile at all. This layout means that 3226 * a corefile is truncated instead of not being created, 3227 * if it is larger than the limit. 3228 */ 3229 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3230 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3231 PROC_UNLOCK(p); 3232 return (EFBIG); 3233 } 3234 PROC_UNLOCK(p); 3235 3236 restart: 3237 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3238 &vp, &name); 3239 if (error != 0) 3240 return (error); 3241 3242 /* Don't dump to non-regular files or files with links. */ 3243 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3244 vattr.va_nlink != 1) { 3245 VOP_UNLOCK(vp, 0); 3246 error = EFAULT; 3247 goto close; 3248 } 3249 3250 VOP_UNLOCK(vp, 0); 3251 lf.l_whence = SEEK_SET; 3252 lf.l_start = 0; 3253 lf.l_len = 0; 3254 lf.l_type = F_WRLCK; 3255 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3256 3257 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3258 lf.l_type = F_UNLCK; 3259 if (locked) 3260 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3261 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3262 goto out; 3263 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3264 goto out; 3265 free(name, M_TEMP); 3266 goto restart; 3267 } 3268 3269 VATTR_NULL(&vattr); 3270 vattr.va_size = 0; 3271 if (set_core_nodump_flag) 3272 vattr.va_flags = UF_NODUMP; 3273 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3274 VOP_SETATTR(vp, &vattr, cred); 3275 VOP_UNLOCK(vp, 0); 3276 vn_finished_write(mp); 3277 PROC_LOCK(p); 3278 p->p_acflag |= ACORE; 3279 PROC_UNLOCK(p); 3280 3281 if (p->p_sysent->sv_coredump != NULL) { 3282 error = p->p_sysent->sv_coredump(td, vp, limit, 3283 compress ? IMGACT_CORE_COMPRESS : 0); 3284 } else { 3285 error = ENOSYS; 3286 } 3287 3288 if (locked) { 3289 lf.l_type = F_UNLCK; 3290 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3291 } 3292 close: 3293 error1 = vn_close(vp, FWRITE, cred, td); 3294 if (error == 0) 3295 error = error1; 3296 out: 3297 #ifdef AUDIT 3298 audit_proc_coredump(td, name, error); 3299 #endif 3300 free(name, M_TEMP); 3301 return (error); 3302 } 3303 3304 /* 3305 * Nonexistent system call-- signal process (may want to handle it). Flag 3306 * error in case process won't see signal immediately (blocked or ignored). 3307 */ 3308 #ifndef _SYS_SYSPROTO_H_ 3309 struct nosys_args { 3310 int dummy; 3311 }; 3312 #endif 3313 /* ARGSUSED */ 3314 int 3315 nosys(td, args) 3316 struct thread *td; 3317 struct nosys_args *args; 3318 { 3319 struct proc *p = td->td_proc; 3320 3321 PROC_LOCK(p); 3322 tdsignal(td, SIGSYS); 3323 PROC_UNLOCK(p); 3324 return (ENOSYS); 3325 } 3326 3327 /* 3328 * Send a SIGIO or SIGURG signal to a process or process group using stored 3329 * credentials rather than those of the current process. 3330 */ 3331 void 3332 pgsigio(sigiop, sig, checkctty) 3333 struct sigio **sigiop; 3334 int sig, checkctty; 3335 { 3336 ksiginfo_t ksi; 3337 struct sigio *sigio; 3338 3339 ksiginfo_init(&ksi); 3340 ksi.ksi_signo = sig; 3341 ksi.ksi_code = SI_KERNEL; 3342 3343 SIGIO_LOCK(); 3344 sigio = *sigiop; 3345 if (sigio == NULL) { 3346 SIGIO_UNLOCK(); 3347 return; 3348 } 3349 if (sigio->sio_pgid > 0) { 3350 PROC_LOCK(sigio->sio_proc); 3351 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3352 kern_psignal(sigio->sio_proc, sig); 3353 PROC_UNLOCK(sigio->sio_proc); 3354 } else if (sigio->sio_pgid < 0) { 3355 struct proc *p; 3356 3357 PGRP_LOCK(sigio->sio_pgrp); 3358 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3359 PROC_LOCK(p); 3360 if (p->p_state == PRS_NORMAL && 3361 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3362 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3363 kern_psignal(p, sig); 3364 PROC_UNLOCK(p); 3365 } 3366 PGRP_UNLOCK(sigio->sio_pgrp); 3367 } 3368 SIGIO_UNLOCK(); 3369 } 3370 3371 static int 3372 filt_sigattach(struct knote *kn) 3373 { 3374 struct proc *p = curproc; 3375 3376 kn->kn_ptr.p_proc = p; 3377 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3378 3379 knlist_add(&p->p_klist, kn, 0); 3380 3381 return (0); 3382 } 3383 3384 static void 3385 filt_sigdetach(struct knote *kn) 3386 { 3387 struct proc *p = kn->kn_ptr.p_proc; 3388 3389 knlist_remove(&p->p_klist, kn, 0); 3390 } 3391 3392 /* 3393 * signal knotes are shared with proc knotes, so we apply a mask to 3394 * the hint in order to differentiate them from process hints. This 3395 * could be avoided by using a signal-specific knote list, but probably 3396 * isn't worth the trouble. 3397 */ 3398 static int 3399 filt_signal(struct knote *kn, long hint) 3400 { 3401 3402 if (hint & NOTE_SIGNAL) { 3403 hint &= ~NOTE_SIGNAL; 3404 3405 if (kn->kn_id == hint) 3406 kn->kn_data++; 3407 } 3408 return (kn->kn_data != 0); 3409 } 3410 3411 struct sigacts * 3412 sigacts_alloc(void) 3413 { 3414 struct sigacts *ps; 3415 3416 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3417 ps->ps_refcnt = 1; 3418 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3419 return (ps); 3420 } 3421 3422 void 3423 sigacts_free(struct sigacts *ps) 3424 { 3425 3426 if (refcount_release(&ps->ps_refcnt) == 0) 3427 return; 3428 mtx_destroy(&ps->ps_mtx); 3429 free(ps, M_SUBPROC); 3430 } 3431 3432 struct sigacts * 3433 sigacts_hold(struct sigacts *ps) 3434 { 3435 3436 refcount_acquire(&ps->ps_refcnt); 3437 return (ps); 3438 } 3439 3440 void 3441 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3442 { 3443 3444 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3445 mtx_lock(&src->ps_mtx); 3446 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3447 mtx_unlock(&src->ps_mtx); 3448 } 3449 3450 int 3451 sigacts_shared(struct sigacts *ps) 3452 { 3453 3454 return (ps->ps_refcnt > 1); 3455 } 3456