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 static bool 625 sigact_flag_test(struct sigaction *act, int flag) 626 { 627 628 /* 629 * SA_SIGINFO is reset when signal disposition is set to 630 * ignore or default. Other flags are kept according to user 631 * settings. 632 */ 633 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 634 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 635 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 636 } 637 638 /* 639 * kern_sigaction 640 * sigaction 641 * freebsd4_sigaction 642 * osigaction 643 */ 644 int 645 kern_sigaction(td, sig, act, oact, flags) 646 struct thread *td; 647 register int sig; 648 struct sigaction *act, *oact; 649 int flags; 650 { 651 struct sigacts *ps; 652 struct proc *p = td->td_proc; 653 654 if (!_SIG_VALID(sig)) 655 return (EINVAL); 656 if (act != NULL && act->sa_handler != SIG_DFL && 657 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 658 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 659 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 660 return (EINVAL); 661 662 PROC_LOCK(p); 663 ps = p->p_sigacts; 664 mtx_lock(&ps->ps_mtx); 665 if (oact) { 666 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 667 oact->sa_flags = 0; 668 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 669 oact->sa_flags |= SA_ONSTACK; 670 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 671 oact->sa_flags |= SA_RESTART; 672 if (SIGISMEMBER(ps->ps_sigreset, sig)) 673 oact->sa_flags |= SA_RESETHAND; 674 if (SIGISMEMBER(ps->ps_signodefer, sig)) 675 oact->sa_flags |= SA_NODEFER; 676 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 677 oact->sa_flags |= SA_SIGINFO; 678 oact->sa_sigaction = 679 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 680 } else 681 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 682 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 683 oact->sa_flags |= SA_NOCLDSTOP; 684 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 685 oact->sa_flags |= SA_NOCLDWAIT; 686 } 687 if (act) { 688 if ((sig == SIGKILL || sig == SIGSTOP) && 689 act->sa_handler != SIG_DFL) { 690 mtx_unlock(&ps->ps_mtx); 691 PROC_UNLOCK(p); 692 return (EINVAL); 693 } 694 695 /* 696 * Change setting atomically. 697 */ 698 699 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 700 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 701 if (sigact_flag_test(act, SA_SIGINFO)) { 702 ps->ps_sigact[_SIG_IDX(sig)] = 703 (__sighandler_t *)act->sa_sigaction; 704 SIGADDSET(ps->ps_siginfo, sig); 705 } else { 706 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 707 SIGDELSET(ps->ps_siginfo, sig); 708 } 709 if (!sigact_flag_test(act, SA_RESTART)) 710 SIGADDSET(ps->ps_sigintr, sig); 711 else 712 SIGDELSET(ps->ps_sigintr, sig); 713 if (sigact_flag_test(act, SA_ONSTACK)) 714 SIGADDSET(ps->ps_sigonstack, sig); 715 else 716 SIGDELSET(ps->ps_sigonstack, sig); 717 if (sigact_flag_test(act, SA_RESETHAND)) 718 SIGADDSET(ps->ps_sigreset, sig); 719 else 720 SIGDELSET(ps->ps_sigreset, sig); 721 if (sigact_flag_test(act, SA_NODEFER)) 722 SIGADDSET(ps->ps_signodefer, sig); 723 else 724 SIGDELSET(ps->ps_signodefer, sig); 725 if (sig == SIGCHLD) { 726 if (act->sa_flags & SA_NOCLDSTOP) 727 ps->ps_flag |= PS_NOCLDSTOP; 728 else 729 ps->ps_flag &= ~PS_NOCLDSTOP; 730 if (act->sa_flags & SA_NOCLDWAIT) { 731 /* 732 * Paranoia: since SA_NOCLDWAIT is implemented 733 * by reparenting the dying child to PID 1 (and 734 * trust it to reap the zombie), PID 1 itself 735 * is forbidden to set SA_NOCLDWAIT. 736 */ 737 if (p->p_pid == 1) 738 ps->ps_flag &= ~PS_NOCLDWAIT; 739 else 740 ps->ps_flag |= PS_NOCLDWAIT; 741 } else 742 ps->ps_flag &= ~PS_NOCLDWAIT; 743 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 744 ps->ps_flag |= PS_CLDSIGIGN; 745 else 746 ps->ps_flag &= ~PS_CLDSIGIGN; 747 } 748 /* 749 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 750 * and for signals set to SIG_DFL where the default is to 751 * ignore. However, don't put SIGCONT in ps_sigignore, as we 752 * have to restart the process. 753 */ 754 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 755 (sigprop(sig) & SA_IGNORE && 756 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 757 /* never to be seen again */ 758 sigqueue_delete_proc(p, sig); 759 if (sig != SIGCONT) 760 /* easier in psignal */ 761 SIGADDSET(ps->ps_sigignore, sig); 762 SIGDELSET(ps->ps_sigcatch, sig); 763 } else { 764 SIGDELSET(ps->ps_sigignore, sig); 765 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 766 SIGDELSET(ps->ps_sigcatch, sig); 767 else 768 SIGADDSET(ps->ps_sigcatch, sig); 769 } 770 #ifdef COMPAT_FREEBSD4 771 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 772 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 773 (flags & KSA_FREEBSD4) == 0) 774 SIGDELSET(ps->ps_freebsd4, sig); 775 else 776 SIGADDSET(ps->ps_freebsd4, sig); 777 #endif 778 #ifdef COMPAT_43 779 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 780 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 781 (flags & KSA_OSIGSET) == 0) 782 SIGDELSET(ps->ps_osigset, sig); 783 else 784 SIGADDSET(ps->ps_osigset, sig); 785 #endif 786 } 787 mtx_unlock(&ps->ps_mtx); 788 PROC_UNLOCK(p); 789 return (0); 790 } 791 792 #ifndef _SYS_SYSPROTO_H_ 793 struct sigaction_args { 794 int sig; 795 struct sigaction *act; 796 struct sigaction *oact; 797 }; 798 #endif 799 int 800 sys_sigaction(td, uap) 801 struct thread *td; 802 register struct sigaction_args *uap; 803 { 804 struct sigaction act, oact; 805 register struct sigaction *actp, *oactp; 806 int error; 807 808 actp = (uap->act != NULL) ? &act : NULL; 809 oactp = (uap->oact != NULL) ? &oact : NULL; 810 if (actp) { 811 error = copyin(uap->act, actp, sizeof(act)); 812 if (error) 813 return (error); 814 } 815 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 816 if (oactp && !error) 817 error = copyout(oactp, uap->oact, sizeof(oact)); 818 return (error); 819 } 820 821 #ifdef COMPAT_FREEBSD4 822 #ifndef _SYS_SYSPROTO_H_ 823 struct freebsd4_sigaction_args { 824 int sig; 825 struct sigaction *act; 826 struct sigaction *oact; 827 }; 828 #endif 829 int 830 freebsd4_sigaction(td, uap) 831 struct thread *td; 832 register struct freebsd4_sigaction_args *uap; 833 { 834 struct sigaction act, oact; 835 register struct sigaction *actp, *oactp; 836 int error; 837 838 839 actp = (uap->act != NULL) ? &act : NULL; 840 oactp = (uap->oact != NULL) ? &oact : NULL; 841 if (actp) { 842 error = copyin(uap->act, actp, sizeof(act)); 843 if (error) 844 return (error); 845 } 846 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 847 if (oactp && !error) 848 error = copyout(oactp, uap->oact, sizeof(oact)); 849 return (error); 850 } 851 #endif /* COMAPT_FREEBSD4 */ 852 853 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 854 #ifndef _SYS_SYSPROTO_H_ 855 struct osigaction_args { 856 int signum; 857 struct osigaction *nsa; 858 struct osigaction *osa; 859 }; 860 #endif 861 int 862 osigaction(td, uap) 863 struct thread *td; 864 register struct osigaction_args *uap; 865 { 866 struct osigaction sa; 867 struct sigaction nsa, osa; 868 register struct sigaction *nsap, *osap; 869 int error; 870 871 if (uap->signum <= 0 || uap->signum >= ONSIG) 872 return (EINVAL); 873 874 nsap = (uap->nsa != NULL) ? &nsa : NULL; 875 osap = (uap->osa != NULL) ? &osa : NULL; 876 877 if (nsap) { 878 error = copyin(uap->nsa, &sa, sizeof(sa)); 879 if (error) 880 return (error); 881 nsap->sa_handler = sa.sa_handler; 882 nsap->sa_flags = sa.sa_flags; 883 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 884 } 885 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 886 if (osap && !error) { 887 sa.sa_handler = osap->sa_handler; 888 sa.sa_flags = osap->sa_flags; 889 SIG2OSIG(osap->sa_mask, sa.sa_mask); 890 error = copyout(&sa, uap->osa, sizeof(sa)); 891 } 892 return (error); 893 } 894 895 #if !defined(__i386__) 896 /* Avoid replicating the same stub everywhere */ 897 int 898 osigreturn(td, uap) 899 struct thread *td; 900 struct osigreturn_args *uap; 901 { 902 903 return (nosys(td, (struct nosys_args *)uap)); 904 } 905 #endif 906 #endif /* COMPAT_43 */ 907 908 /* 909 * Initialize signal state for process 0; 910 * set to ignore signals that are ignored by default. 911 */ 912 void 913 siginit(p) 914 struct proc *p; 915 { 916 register int i; 917 struct sigacts *ps; 918 919 PROC_LOCK(p); 920 ps = p->p_sigacts; 921 mtx_lock(&ps->ps_mtx); 922 for (i = 1; i <= NSIG; i++) { 923 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 924 SIGADDSET(ps->ps_sigignore, i); 925 } 926 } 927 mtx_unlock(&ps->ps_mtx); 928 PROC_UNLOCK(p); 929 } 930 931 /* 932 * Reset specified signal to the default disposition. 933 */ 934 static void 935 sigdflt(struct sigacts *ps, int sig) 936 { 937 938 mtx_assert(&ps->ps_mtx, MA_OWNED); 939 SIGDELSET(ps->ps_sigcatch, sig); 940 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 941 SIGADDSET(ps->ps_sigignore, sig); 942 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 943 SIGDELSET(ps->ps_siginfo, sig); 944 } 945 946 /* 947 * Reset signals for an exec of the specified process. 948 */ 949 void 950 execsigs(struct proc *p) 951 { 952 struct sigacts *ps; 953 int sig; 954 struct thread *td; 955 956 /* 957 * Reset caught signals. Held signals remain held 958 * through td_sigmask (unless they were caught, 959 * and are now ignored by default). 960 */ 961 PROC_LOCK_ASSERT(p, MA_OWNED); 962 td = FIRST_THREAD_IN_PROC(p); 963 ps = p->p_sigacts; 964 mtx_lock(&ps->ps_mtx); 965 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 966 sig = sig_ffs(&ps->ps_sigcatch); 967 sigdflt(ps, sig); 968 if ((sigprop(sig) & SA_IGNORE) != 0) 969 sigqueue_delete_proc(p, sig); 970 } 971 /* 972 * Reset stack state to the user stack. 973 * Clear set of signals caught on the signal stack. 974 */ 975 td->td_sigstk.ss_flags = SS_DISABLE; 976 td->td_sigstk.ss_size = 0; 977 td->td_sigstk.ss_sp = 0; 978 td->td_pflags &= ~TDP_ALTSTACK; 979 /* 980 * Reset no zombies if child dies flag as Solaris does. 981 */ 982 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 983 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 984 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 985 mtx_unlock(&ps->ps_mtx); 986 } 987 988 /* 989 * kern_sigprocmask() 990 * 991 * Manipulate signal mask. 992 */ 993 int 994 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 995 int flags) 996 { 997 sigset_t new_block, oset1; 998 struct proc *p; 999 int error; 1000 1001 p = td->td_proc; 1002 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1003 PROC_LOCK_ASSERT(p, MA_OWNED); 1004 else 1005 PROC_LOCK(p); 1006 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1007 ? MA_OWNED : MA_NOTOWNED); 1008 if (oset != NULL) 1009 *oset = td->td_sigmask; 1010 1011 error = 0; 1012 if (set != NULL) { 1013 switch (how) { 1014 case SIG_BLOCK: 1015 SIG_CANTMASK(*set); 1016 oset1 = td->td_sigmask; 1017 SIGSETOR(td->td_sigmask, *set); 1018 new_block = td->td_sigmask; 1019 SIGSETNAND(new_block, oset1); 1020 break; 1021 case SIG_UNBLOCK: 1022 SIGSETNAND(td->td_sigmask, *set); 1023 signotify(td); 1024 goto out; 1025 case SIG_SETMASK: 1026 SIG_CANTMASK(*set); 1027 oset1 = td->td_sigmask; 1028 if (flags & SIGPROCMASK_OLD) 1029 SIGSETLO(td->td_sigmask, *set); 1030 else 1031 td->td_sigmask = *set; 1032 new_block = td->td_sigmask; 1033 SIGSETNAND(new_block, oset1); 1034 signotify(td); 1035 break; 1036 default: 1037 error = EINVAL; 1038 goto out; 1039 } 1040 1041 /* 1042 * The new_block set contains signals that were not previously 1043 * blocked, but are blocked now. 1044 * 1045 * In case we block any signal that was not previously blocked 1046 * for td, and process has the signal pending, try to schedule 1047 * signal delivery to some thread that does not block the 1048 * signal, possibly waking it up. 1049 */ 1050 if (p->p_numthreads != 1) 1051 reschedule_signals(p, new_block, flags); 1052 } 1053 1054 out: 1055 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1056 PROC_UNLOCK(p); 1057 return (error); 1058 } 1059 1060 #ifndef _SYS_SYSPROTO_H_ 1061 struct sigprocmask_args { 1062 int how; 1063 const sigset_t *set; 1064 sigset_t *oset; 1065 }; 1066 #endif 1067 int 1068 sys_sigprocmask(td, uap) 1069 register struct thread *td; 1070 struct sigprocmask_args *uap; 1071 { 1072 sigset_t set, oset; 1073 sigset_t *setp, *osetp; 1074 int error; 1075 1076 setp = (uap->set != NULL) ? &set : NULL; 1077 osetp = (uap->oset != NULL) ? &oset : NULL; 1078 if (setp) { 1079 error = copyin(uap->set, setp, sizeof(set)); 1080 if (error) 1081 return (error); 1082 } 1083 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1084 if (osetp && !error) { 1085 error = copyout(osetp, uap->oset, sizeof(oset)); 1086 } 1087 return (error); 1088 } 1089 1090 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1091 #ifndef _SYS_SYSPROTO_H_ 1092 struct osigprocmask_args { 1093 int how; 1094 osigset_t mask; 1095 }; 1096 #endif 1097 int 1098 osigprocmask(td, uap) 1099 register struct thread *td; 1100 struct osigprocmask_args *uap; 1101 { 1102 sigset_t set, oset; 1103 int error; 1104 1105 OSIG2SIG(uap->mask, set); 1106 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1107 SIG2OSIG(oset, td->td_retval[0]); 1108 return (error); 1109 } 1110 #endif /* COMPAT_43 */ 1111 1112 int 1113 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1114 { 1115 ksiginfo_t ksi; 1116 sigset_t set; 1117 int error; 1118 1119 error = copyin(uap->set, &set, sizeof(set)); 1120 if (error) { 1121 td->td_retval[0] = error; 1122 return (0); 1123 } 1124 1125 error = kern_sigtimedwait(td, set, &ksi, NULL); 1126 if (error) { 1127 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1128 error = ERESTART; 1129 if (error == ERESTART) 1130 return (error); 1131 td->td_retval[0] = error; 1132 return (0); 1133 } 1134 1135 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1136 td->td_retval[0] = error; 1137 return (0); 1138 } 1139 1140 int 1141 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1142 { 1143 struct timespec ts; 1144 struct timespec *timeout; 1145 sigset_t set; 1146 ksiginfo_t ksi; 1147 int error; 1148 1149 if (uap->timeout) { 1150 error = copyin(uap->timeout, &ts, sizeof(ts)); 1151 if (error) 1152 return (error); 1153 1154 timeout = &ts; 1155 } else 1156 timeout = NULL; 1157 1158 error = copyin(uap->set, &set, sizeof(set)); 1159 if (error) 1160 return (error); 1161 1162 error = kern_sigtimedwait(td, set, &ksi, timeout); 1163 if (error) 1164 return (error); 1165 1166 if (uap->info) 1167 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1168 1169 if (error == 0) 1170 td->td_retval[0] = ksi.ksi_signo; 1171 return (error); 1172 } 1173 1174 int 1175 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1176 { 1177 ksiginfo_t ksi; 1178 sigset_t set; 1179 int error; 1180 1181 error = copyin(uap->set, &set, sizeof(set)); 1182 if (error) 1183 return (error); 1184 1185 error = kern_sigtimedwait(td, set, &ksi, NULL); 1186 if (error) 1187 return (error); 1188 1189 if (uap->info) 1190 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1191 1192 if (error == 0) 1193 td->td_retval[0] = ksi.ksi_signo; 1194 return (error); 1195 } 1196 1197 int 1198 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1199 struct timespec *timeout) 1200 { 1201 struct sigacts *ps; 1202 sigset_t saved_mask, new_block; 1203 struct proc *p; 1204 int error, sig, timo, timevalid = 0; 1205 struct timespec rts, ets, ts; 1206 struct timeval tv; 1207 1208 p = td->td_proc; 1209 error = 0; 1210 ets.tv_sec = 0; 1211 ets.tv_nsec = 0; 1212 1213 if (timeout != NULL) { 1214 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1215 timevalid = 1; 1216 getnanouptime(&rts); 1217 ets = rts; 1218 timespecadd(&ets, timeout); 1219 } 1220 } 1221 ksiginfo_init(ksi); 1222 /* Some signals can not be waited for. */ 1223 SIG_CANTMASK(waitset); 1224 ps = p->p_sigacts; 1225 PROC_LOCK(p); 1226 saved_mask = td->td_sigmask; 1227 SIGSETNAND(td->td_sigmask, waitset); 1228 for (;;) { 1229 mtx_lock(&ps->ps_mtx); 1230 sig = cursig(td); 1231 mtx_unlock(&ps->ps_mtx); 1232 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1233 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1234 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1235 error = 0; 1236 break; 1237 } 1238 } 1239 1240 if (error != 0) 1241 break; 1242 1243 /* 1244 * POSIX says this must be checked after looking for pending 1245 * signals. 1246 */ 1247 if (timeout != NULL) { 1248 if (!timevalid) { 1249 error = EINVAL; 1250 break; 1251 } 1252 getnanouptime(&rts); 1253 if (timespeccmp(&rts, &ets, >=)) { 1254 error = EAGAIN; 1255 break; 1256 } 1257 ts = ets; 1258 timespecsub(&ts, &rts); 1259 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1260 timo = tvtohz(&tv); 1261 } else { 1262 timo = 0; 1263 } 1264 1265 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1266 1267 if (timeout != NULL) { 1268 if (error == ERESTART) { 1269 /* Timeout can not be restarted. */ 1270 error = EINTR; 1271 } else if (error == EAGAIN) { 1272 /* We will calculate timeout by ourself. */ 1273 error = 0; 1274 } 1275 } 1276 } 1277 1278 new_block = saved_mask; 1279 SIGSETNAND(new_block, td->td_sigmask); 1280 td->td_sigmask = saved_mask; 1281 /* 1282 * Fewer signals can be delivered to us, reschedule signal 1283 * notification. 1284 */ 1285 if (p->p_numthreads != 1) 1286 reschedule_signals(p, new_block, 0); 1287 1288 if (error == 0) { 1289 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0); 1290 1291 if (ksi->ksi_code == SI_TIMER) 1292 itimer_accept(p, ksi->ksi_timerid, ksi); 1293 1294 #ifdef KTRACE 1295 if (KTRPOINT(td, KTR_PSIG)) { 1296 sig_t action; 1297 1298 mtx_lock(&ps->ps_mtx); 1299 action = ps->ps_sigact[_SIG_IDX(sig)]; 1300 mtx_unlock(&ps->ps_mtx); 1301 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1302 } 1303 #endif 1304 if (sig == SIGKILL) 1305 sigexit(td, sig); 1306 } 1307 PROC_UNLOCK(p); 1308 return (error); 1309 } 1310 1311 #ifndef _SYS_SYSPROTO_H_ 1312 struct sigpending_args { 1313 sigset_t *set; 1314 }; 1315 #endif 1316 int 1317 sys_sigpending(td, uap) 1318 struct thread *td; 1319 struct sigpending_args *uap; 1320 { 1321 struct proc *p = td->td_proc; 1322 sigset_t pending; 1323 1324 PROC_LOCK(p); 1325 pending = p->p_sigqueue.sq_signals; 1326 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1327 PROC_UNLOCK(p); 1328 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1329 } 1330 1331 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1332 #ifndef _SYS_SYSPROTO_H_ 1333 struct osigpending_args { 1334 int dummy; 1335 }; 1336 #endif 1337 int 1338 osigpending(td, uap) 1339 struct thread *td; 1340 struct osigpending_args *uap; 1341 { 1342 struct proc *p = td->td_proc; 1343 sigset_t pending; 1344 1345 PROC_LOCK(p); 1346 pending = p->p_sigqueue.sq_signals; 1347 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1348 PROC_UNLOCK(p); 1349 SIG2OSIG(pending, td->td_retval[0]); 1350 return (0); 1351 } 1352 #endif /* COMPAT_43 */ 1353 1354 #if defined(COMPAT_43) 1355 /* 1356 * Generalized interface signal handler, 4.3-compatible. 1357 */ 1358 #ifndef _SYS_SYSPROTO_H_ 1359 struct osigvec_args { 1360 int signum; 1361 struct sigvec *nsv; 1362 struct sigvec *osv; 1363 }; 1364 #endif 1365 /* ARGSUSED */ 1366 int 1367 osigvec(td, uap) 1368 struct thread *td; 1369 register struct osigvec_args *uap; 1370 { 1371 struct sigvec vec; 1372 struct sigaction nsa, osa; 1373 register struct sigaction *nsap, *osap; 1374 int error; 1375 1376 if (uap->signum <= 0 || uap->signum >= ONSIG) 1377 return (EINVAL); 1378 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1379 osap = (uap->osv != NULL) ? &osa : NULL; 1380 if (nsap) { 1381 error = copyin(uap->nsv, &vec, sizeof(vec)); 1382 if (error) 1383 return (error); 1384 nsap->sa_handler = vec.sv_handler; 1385 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1386 nsap->sa_flags = vec.sv_flags; 1387 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1388 } 1389 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1390 if (osap && !error) { 1391 vec.sv_handler = osap->sa_handler; 1392 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1393 vec.sv_flags = osap->sa_flags; 1394 vec.sv_flags &= ~SA_NOCLDWAIT; 1395 vec.sv_flags ^= SA_RESTART; 1396 error = copyout(&vec, uap->osv, sizeof(vec)); 1397 } 1398 return (error); 1399 } 1400 1401 #ifndef _SYS_SYSPROTO_H_ 1402 struct osigblock_args { 1403 int mask; 1404 }; 1405 #endif 1406 int 1407 osigblock(td, uap) 1408 register struct thread *td; 1409 struct osigblock_args *uap; 1410 { 1411 sigset_t set, oset; 1412 1413 OSIG2SIG(uap->mask, set); 1414 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1415 SIG2OSIG(oset, td->td_retval[0]); 1416 return (0); 1417 } 1418 1419 #ifndef _SYS_SYSPROTO_H_ 1420 struct osigsetmask_args { 1421 int mask; 1422 }; 1423 #endif 1424 int 1425 osigsetmask(td, uap) 1426 struct thread *td; 1427 struct osigsetmask_args *uap; 1428 { 1429 sigset_t set, oset; 1430 1431 OSIG2SIG(uap->mask, set); 1432 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1433 SIG2OSIG(oset, td->td_retval[0]); 1434 return (0); 1435 } 1436 #endif /* COMPAT_43 */ 1437 1438 /* 1439 * Suspend calling thread until signal, providing mask to be set in the 1440 * meantime. 1441 */ 1442 #ifndef _SYS_SYSPROTO_H_ 1443 struct sigsuspend_args { 1444 const sigset_t *sigmask; 1445 }; 1446 #endif 1447 /* ARGSUSED */ 1448 int 1449 sys_sigsuspend(td, uap) 1450 struct thread *td; 1451 struct sigsuspend_args *uap; 1452 { 1453 sigset_t mask; 1454 int error; 1455 1456 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1457 if (error) 1458 return (error); 1459 return (kern_sigsuspend(td, mask)); 1460 } 1461 1462 int 1463 kern_sigsuspend(struct thread *td, sigset_t mask) 1464 { 1465 struct proc *p = td->td_proc; 1466 int has_sig, sig; 1467 1468 /* 1469 * When returning from sigsuspend, we want 1470 * the old mask to be restored after the 1471 * signal handler has finished. Thus, we 1472 * save it here and mark the sigacts structure 1473 * to indicate this. 1474 */ 1475 PROC_LOCK(p); 1476 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1477 SIGPROCMASK_PROC_LOCKED); 1478 td->td_pflags |= TDP_OLDMASK; 1479 1480 /* 1481 * Process signals now. Otherwise, we can get spurious wakeup 1482 * due to signal entered process queue, but delivered to other 1483 * thread. But sigsuspend should return only on signal 1484 * delivery. 1485 */ 1486 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1487 for (has_sig = 0; !has_sig;) { 1488 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1489 0) == 0) 1490 /* void */; 1491 thread_suspend_check(0); 1492 mtx_lock(&p->p_sigacts->ps_mtx); 1493 while ((sig = cursig(td)) != 0) 1494 has_sig += postsig(sig); 1495 mtx_unlock(&p->p_sigacts->ps_mtx); 1496 } 1497 PROC_UNLOCK(p); 1498 td->td_errno = EINTR; 1499 td->td_pflags |= TDP_NERRNO; 1500 return (EJUSTRETURN); 1501 } 1502 1503 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1504 /* 1505 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1506 * convention: libc stub passes mask, not pointer, to save a copyin. 1507 */ 1508 #ifndef _SYS_SYSPROTO_H_ 1509 struct osigsuspend_args { 1510 osigset_t mask; 1511 }; 1512 #endif 1513 /* ARGSUSED */ 1514 int 1515 osigsuspend(td, uap) 1516 struct thread *td; 1517 struct osigsuspend_args *uap; 1518 { 1519 sigset_t mask; 1520 1521 OSIG2SIG(uap->mask, mask); 1522 return (kern_sigsuspend(td, mask)); 1523 } 1524 #endif /* COMPAT_43 */ 1525 1526 #if defined(COMPAT_43) 1527 #ifndef _SYS_SYSPROTO_H_ 1528 struct osigstack_args { 1529 struct sigstack *nss; 1530 struct sigstack *oss; 1531 }; 1532 #endif 1533 /* ARGSUSED */ 1534 int 1535 osigstack(td, uap) 1536 struct thread *td; 1537 register struct osigstack_args *uap; 1538 { 1539 struct sigstack nss, oss; 1540 int error = 0; 1541 1542 if (uap->nss != NULL) { 1543 error = copyin(uap->nss, &nss, sizeof(nss)); 1544 if (error) 1545 return (error); 1546 } 1547 oss.ss_sp = td->td_sigstk.ss_sp; 1548 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1549 if (uap->nss != NULL) { 1550 td->td_sigstk.ss_sp = nss.ss_sp; 1551 td->td_sigstk.ss_size = 0; 1552 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1553 td->td_pflags |= TDP_ALTSTACK; 1554 } 1555 if (uap->oss != NULL) 1556 error = copyout(&oss, uap->oss, sizeof(oss)); 1557 1558 return (error); 1559 } 1560 #endif /* COMPAT_43 */ 1561 1562 #ifndef _SYS_SYSPROTO_H_ 1563 struct sigaltstack_args { 1564 stack_t *ss; 1565 stack_t *oss; 1566 }; 1567 #endif 1568 /* ARGSUSED */ 1569 int 1570 sys_sigaltstack(td, uap) 1571 struct thread *td; 1572 register struct sigaltstack_args *uap; 1573 { 1574 stack_t ss, oss; 1575 int error; 1576 1577 if (uap->ss != NULL) { 1578 error = copyin(uap->ss, &ss, sizeof(ss)); 1579 if (error) 1580 return (error); 1581 } 1582 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1583 (uap->oss != NULL) ? &oss : NULL); 1584 if (error) 1585 return (error); 1586 if (uap->oss != NULL) 1587 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1588 return (error); 1589 } 1590 1591 int 1592 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1593 { 1594 struct proc *p = td->td_proc; 1595 int oonstack; 1596 1597 oonstack = sigonstack(cpu_getstack(td)); 1598 1599 if (oss != NULL) { 1600 *oss = td->td_sigstk; 1601 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1602 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1603 } 1604 1605 if (ss != NULL) { 1606 if (oonstack) 1607 return (EPERM); 1608 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1609 return (EINVAL); 1610 if (!(ss->ss_flags & SS_DISABLE)) { 1611 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1612 return (ENOMEM); 1613 1614 td->td_sigstk = *ss; 1615 td->td_pflags |= TDP_ALTSTACK; 1616 } else { 1617 td->td_pflags &= ~TDP_ALTSTACK; 1618 } 1619 } 1620 return (0); 1621 } 1622 1623 /* 1624 * Common code for kill process group/broadcast kill. 1625 * cp is calling process. 1626 */ 1627 static int 1628 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1629 { 1630 struct proc *p; 1631 struct pgrp *pgrp; 1632 int err; 1633 int ret; 1634 1635 ret = ESRCH; 1636 if (all) { 1637 /* 1638 * broadcast 1639 */ 1640 sx_slock(&allproc_lock); 1641 FOREACH_PROC_IN_SYSTEM(p) { 1642 PROC_LOCK(p); 1643 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1644 p == td->td_proc || p->p_state == PRS_NEW) { 1645 PROC_UNLOCK(p); 1646 continue; 1647 } 1648 err = p_cansignal(td, p, sig); 1649 if (err == 0) { 1650 if (sig) 1651 pksignal(p, sig, ksi); 1652 ret = err; 1653 } 1654 else if (ret == ESRCH) 1655 ret = err; 1656 PROC_UNLOCK(p); 1657 } 1658 sx_sunlock(&allproc_lock); 1659 } else { 1660 sx_slock(&proctree_lock); 1661 if (pgid == 0) { 1662 /* 1663 * zero pgid means send to my process group. 1664 */ 1665 pgrp = td->td_proc->p_pgrp; 1666 PGRP_LOCK(pgrp); 1667 } else { 1668 pgrp = pgfind(pgid); 1669 if (pgrp == NULL) { 1670 sx_sunlock(&proctree_lock); 1671 return (ESRCH); 1672 } 1673 } 1674 sx_sunlock(&proctree_lock); 1675 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1676 PROC_LOCK(p); 1677 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1678 p->p_state == PRS_NEW) { 1679 PROC_UNLOCK(p); 1680 continue; 1681 } 1682 err = p_cansignal(td, p, sig); 1683 if (err == 0) { 1684 if (sig) 1685 pksignal(p, sig, ksi); 1686 ret = err; 1687 } 1688 else if (ret == ESRCH) 1689 ret = err; 1690 PROC_UNLOCK(p); 1691 } 1692 PGRP_UNLOCK(pgrp); 1693 } 1694 return (ret); 1695 } 1696 1697 #ifndef _SYS_SYSPROTO_H_ 1698 struct kill_args { 1699 int pid; 1700 int signum; 1701 }; 1702 #endif 1703 /* ARGSUSED */ 1704 int 1705 sys_kill(struct thread *td, struct kill_args *uap) 1706 { 1707 ksiginfo_t ksi; 1708 struct proc *p; 1709 int error; 1710 1711 /* 1712 * A process in capability mode can send signals only to himself. 1713 * The main rationale behind this is that abort(3) is implemented as 1714 * kill(getpid(), SIGABRT). 1715 */ 1716 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1717 return (ECAPMODE); 1718 1719 AUDIT_ARG_SIGNUM(uap->signum); 1720 AUDIT_ARG_PID(uap->pid); 1721 if ((u_int)uap->signum > _SIG_MAXSIG) 1722 return (EINVAL); 1723 1724 ksiginfo_init(&ksi); 1725 ksi.ksi_signo = uap->signum; 1726 ksi.ksi_code = SI_USER; 1727 ksi.ksi_pid = td->td_proc->p_pid; 1728 ksi.ksi_uid = td->td_ucred->cr_ruid; 1729 1730 if (uap->pid > 0) { 1731 /* kill single process */ 1732 if ((p = pfind(uap->pid)) == NULL) { 1733 if ((p = zpfind(uap->pid)) == NULL) 1734 return (ESRCH); 1735 } 1736 AUDIT_ARG_PROCESS(p); 1737 error = p_cansignal(td, p, uap->signum); 1738 if (error == 0 && uap->signum) 1739 pksignal(p, uap->signum, &ksi); 1740 PROC_UNLOCK(p); 1741 return (error); 1742 } 1743 switch (uap->pid) { 1744 case -1: /* broadcast signal */ 1745 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1746 case 0: /* signal own process group */ 1747 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1748 default: /* negative explicit process group */ 1749 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1750 } 1751 /* NOTREACHED */ 1752 } 1753 1754 int 1755 sys_pdkill(td, uap) 1756 struct thread *td; 1757 struct pdkill_args *uap; 1758 { 1759 struct proc *p; 1760 cap_rights_t rights; 1761 int error; 1762 1763 AUDIT_ARG_SIGNUM(uap->signum); 1764 AUDIT_ARG_FD(uap->fd); 1765 if ((u_int)uap->signum > _SIG_MAXSIG) 1766 return (EINVAL); 1767 1768 error = procdesc_find(td, uap->fd, 1769 cap_rights_init(&rights, CAP_PDKILL), &p); 1770 if (error) 1771 return (error); 1772 AUDIT_ARG_PROCESS(p); 1773 error = p_cansignal(td, p, uap->signum); 1774 if (error == 0 && uap->signum) 1775 kern_psignal(p, uap->signum); 1776 PROC_UNLOCK(p); 1777 return (error); 1778 } 1779 1780 #if defined(COMPAT_43) 1781 #ifndef _SYS_SYSPROTO_H_ 1782 struct okillpg_args { 1783 int pgid; 1784 int signum; 1785 }; 1786 #endif 1787 /* ARGSUSED */ 1788 int 1789 okillpg(struct thread *td, struct okillpg_args *uap) 1790 { 1791 ksiginfo_t ksi; 1792 1793 AUDIT_ARG_SIGNUM(uap->signum); 1794 AUDIT_ARG_PID(uap->pgid); 1795 if ((u_int)uap->signum > _SIG_MAXSIG) 1796 return (EINVAL); 1797 1798 ksiginfo_init(&ksi); 1799 ksi.ksi_signo = uap->signum; 1800 ksi.ksi_code = SI_USER; 1801 ksi.ksi_pid = td->td_proc->p_pid; 1802 ksi.ksi_uid = td->td_ucred->cr_ruid; 1803 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1804 } 1805 #endif /* COMPAT_43 */ 1806 1807 #ifndef _SYS_SYSPROTO_H_ 1808 struct sigqueue_args { 1809 pid_t pid; 1810 int signum; 1811 /* union sigval */ void *value; 1812 }; 1813 #endif 1814 int 1815 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1816 { 1817 ksiginfo_t ksi; 1818 struct proc *p; 1819 int error; 1820 1821 if ((u_int)uap->signum > _SIG_MAXSIG) 1822 return (EINVAL); 1823 1824 /* 1825 * Specification says sigqueue can only send signal to 1826 * single process. 1827 */ 1828 if (uap->pid <= 0) 1829 return (EINVAL); 1830 1831 if ((p = pfind(uap->pid)) == NULL) { 1832 if ((p = zpfind(uap->pid)) == NULL) 1833 return (ESRCH); 1834 } 1835 error = p_cansignal(td, p, uap->signum); 1836 if (error == 0 && uap->signum != 0) { 1837 ksiginfo_init(&ksi); 1838 ksi.ksi_flags = KSI_SIGQ; 1839 ksi.ksi_signo = uap->signum; 1840 ksi.ksi_code = SI_QUEUE; 1841 ksi.ksi_pid = td->td_proc->p_pid; 1842 ksi.ksi_uid = td->td_ucred->cr_ruid; 1843 ksi.ksi_value.sival_ptr = uap->value; 1844 error = pksignal(p, ksi.ksi_signo, &ksi); 1845 } 1846 PROC_UNLOCK(p); 1847 return (error); 1848 } 1849 1850 /* 1851 * Send a signal to a process group. 1852 */ 1853 void 1854 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1855 { 1856 struct pgrp *pgrp; 1857 1858 if (pgid != 0) { 1859 sx_slock(&proctree_lock); 1860 pgrp = pgfind(pgid); 1861 sx_sunlock(&proctree_lock); 1862 if (pgrp != NULL) { 1863 pgsignal(pgrp, sig, 0, ksi); 1864 PGRP_UNLOCK(pgrp); 1865 } 1866 } 1867 } 1868 1869 /* 1870 * Send a signal to a process group. If checktty is 1, 1871 * limit to members which have a controlling terminal. 1872 */ 1873 void 1874 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1875 { 1876 struct proc *p; 1877 1878 if (pgrp) { 1879 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1880 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1881 PROC_LOCK(p); 1882 if (p->p_state == PRS_NORMAL && 1883 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1884 pksignal(p, sig, ksi); 1885 PROC_UNLOCK(p); 1886 } 1887 } 1888 } 1889 1890 1891 /* 1892 * Recalculate the signal mask and reset the signal disposition after 1893 * usermode frame for delivery is formed. Should be called after 1894 * mach-specific routine, because sysent->sv_sendsig() needs correct 1895 * ps_siginfo and signal mask. 1896 */ 1897 static void 1898 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1899 { 1900 sigset_t mask; 1901 1902 mtx_assert(&ps->ps_mtx, MA_OWNED); 1903 td->td_ru.ru_nsignals++; 1904 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1905 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1906 SIGADDSET(mask, sig); 1907 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1908 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1909 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1910 sigdflt(ps, sig); 1911 } 1912 1913 1914 /* 1915 * Send a signal caused by a trap to the current thread. If it will be 1916 * caught immediately, deliver it with correct code. Otherwise, post it 1917 * normally. 1918 */ 1919 void 1920 trapsignal(struct thread *td, ksiginfo_t *ksi) 1921 { 1922 struct sigacts *ps; 1923 struct proc *p; 1924 int sig; 1925 int code; 1926 1927 p = td->td_proc; 1928 sig = ksi->ksi_signo; 1929 code = ksi->ksi_code; 1930 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1931 1932 PROC_LOCK(p); 1933 ps = p->p_sigacts; 1934 mtx_lock(&ps->ps_mtx); 1935 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1936 !SIGISMEMBER(td->td_sigmask, sig)) { 1937 #ifdef KTRACE 1938 if (KTRPOINT(curthread, KTR_PSIG)) 1939 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1940 &td->td_sigmask, code); 1941 #endif 1942 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1943 ksi, &td->td_sigmask); 1944 postsig_done(sig, td, ps); 1945 mtx_unlock(&ps->ps_mtx); 1946 } else { 1947 /* 1948 * Avoid a possible infinite loop if the thread 1949 * masking the signal or process is ignoring the 1950 * signal. 1951 */ 1952 if (kern_forcesigexit && 1953 (SIGISMEMBER(td->td_sigmask, sig) || 1954 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1955 SIGDELSET(td->td_sigmask, sig); 1956 SIGDELSET(ps->ps_sigcatch, sig); 1957 SIGDELSET(ps->ps_sigignore, sig); 1958 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1959 } 1960 mtx_unlock(&ps->ps_mtx); 1961 p->p_code = code; /* XXX for core dump/debugger */ 1962 p->p_sig = sig; /* XXX to verify code */ 1963 tdsendsignal(p, td, sig, ksi); 1964 } 1965 PROC_UNLOCK(p); 1966 } 1967 1968 static struct thread * 1969 sigtd(struct proc *p, int sig, int prop) 1970 { 1971 struct thread *td, *signal_td; 1972 1973 PROC_LOCK_ASSERT(p, MA_OWNED); 1974 1975 /* 1976 * Check if current thread can handle the signal without 1977 * switching context to another thread. 1978 */ 1979 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1980 return (curthread); 1981 signal_td = NULL; 1982 FOREACH_THREAD_IN_PROC(p, td) { 1983 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1984 signal_td = td; 1985 break; 1986 } 1987 } 1988 if (signal_td == NULL) 1989 signal_td = FIRST_THREAD_IN_PROC(p); 1990 return (signal_td); 1991 } 1992 1993 /* 1994 * Send the signal to the process. If the signal has an action, the action 1995 * is usually performed by the target process rather than the caller; we add 1996 * the signal to the set of pending signals for the process. 1997 * 1998 * Exceptions: 1999 * o When a stop signal is sent to a sleeping process that takes the 2000 * default action, the process is stopped without awakening it. 2001 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2002 * regardless of the signal action (eg, blocked or ignored). 2003 * 2004 * Other ignored signals are discarded immediately. 2005 * 2006 * NB: This function may be entered from the debugger via the "kill" DDB 2007 * command. There is little that can be done to mitigate the possibly messy 2008 * side effects of this unwise possibility. 2009 */ 2010 void 2011 kern_psignal(struct proc *p, int sig) 2012 { 2013 ksiginfo_t ksi; 2014 2015 ksiginfo_init(&ksi); 2016 ksi.ksi_signo = sig; 2017 ksi.ksi_code = SI_KERNEL; 2018 (void) tdsendsignal(p, NULL, sig, &ksi); 2019 } 2020 2021 int 2022 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2023 { 2024 2025 return (tdsendsignal(p, NULL, sig, ksi)); 2026 } 2027 2028 /* Utility function for finding a thread to send signal event to. */ 2029 int 2030 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2031 { 2032 struct thread *td; 2033 2034 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2035 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2036 if (td == NULL) 2037 return (ESRCH); 2038 *ttd = td; 2039 } else { 2040 *ttd = NULL; 2041 PROC_LOCK(p); 2042 } 2043 return (0); 2044 } 2045 2046 void 2047 tdsignal(struct thread *td, int sig) 2048 { 2049 ksiginfo_t ksi; 2050 2051 ksiginfo_init(&ksi); 2052 ksi.ksi_signo = sig; 2053 ksi.ksi_code = SI_KERNEL; 2054 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2055 } 2056 2057 void 2058 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2059 { 2060 2061 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2062 } 2063 2064 int 2065 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2066 { 2067 sig_t action; 2068 sigqueue_t *sigqueue; 2069 int prop; 2070 struct sigacts *ps; 2071 int intrval; 2072 int ret = 0; 2073 int wakeup_swapper; 2074 2075 MPASS(td == NULL || p == td->td_proc); 2076 PROC_LOCK_ASSERT(p, MA_OWNED); 2077 2078 if (!_SIG_VALID(sig)) 2079 panic("%s(): invalid signal %d", __func__, sig); 2080 2081 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2082 2083 /* 2084 * IEEE Std 1003.1-2001: return success when killing a zombie. 2085 */ 2086 if (p->p_state == PRS_ZOMBIE) { 2087 if (ksi && (ksi->ksi_flags & KSI_INS)) 2088 ksiginfo_tryfree(ksi); 2089 return (ret); 2090 } 2091 2092 ps = p->p_sigacts; 2093 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2094 prop = sigprop(sig); 2095 2096 if (td == NULL) { 2097 td = sigtd(p, sig, prop); 2098 sigqueue = &p->p_sigqueue; 2099 } else 2100 sigqueue = &td->td_sigqueue; 2101 2102 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 ); 2103 2104 /* 2105 * If the signal is being ignored, 2106 * then we forget about it immediately. 2107 * (Note: we don't set SIGCONT in ps_sigignore, 2108 * and if it is set to SIG_IGN, 2109 * action will be SIG_DFL here.) 2110 */ 2111 mtx_lock(&ps->ps_mtx); 2112 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2113 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 ); 2114 2115 mtx_unlock(&ps->ps_mtx); 2116 if (ksi && (ksi->ksi_flags & KSI_INS)) 2117 ksiginfo_tryfree(ksi); 2118 return (ret); 2119 } 2120 if (SIGISMEMBER(td->td_sigmask, sig)) 2121 action = SIG_HOLD; 2122 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2123 action = SIG_CATCH; 2124 else 2125 action = SIG_DFL; 2126 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2127 intrval = EINTR; 2128 else 2129 intrval = ERESTART; 2130 mtx_unlock(&ps->ps_mtx); 2131 2132 if (prop & SA_CONT) 2133 sigqueue_delete_stopmask_proc(p); 2134 else if (prop & SA_STOP) { 2135 /* 2136 * If sending a tty stop signal to a member of an orphaned 2137 * process group, discard the signal here if the action 2138 * is default; don't stop the process below if sleeping, 2139 * and don't clear any pending SIGCONT. 2140 */ 2141 if ((prop & SA_TTYSTOP) && 2142 (p->p_pgrp->pg_jobc == 0) && 2143 (action == SIG_DFL)) { 2144 if (ksi && (ksi->ksi_flags & KSI_INS)) 2145 ksiginfo_tryfree(ksi); 2146 return (ret); 2147 } 2148 sigqueue_delete_proc(p, SIGCONT); 2149 if (p->p_flag & P_CONTINUED) { 2150 p->p_flag &= ~P_CONTINUED; 2151 PROC_LOCK(p->p_pptr); 2152 sigqueue_take(p->p_ksi); 2153 PROC_UNLOCK(p->p_pptr); 2154 } 2155 } 2156 2157 ret = sigqueue_add(sigqueue, sig, ksi); 2158 if (ret != 0) 2159 return (ret); 2160 signotify(td); 2161 /* 2162 * Defer further processing for signals which are held, 2163 * except that stopped processes must be continued by SIGCONT. 2164 */ 2165 if (action == SIG_HOLD && 2166 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2167 return (ret); 2168 /* 2169 * SIGKILL: Remove procfs STOPEVENTs. 2170 */ 2171 if (sig == SIGKILL) { 2172 /* from procfs_ioctl.c: PIOCBIC */ 2173 p->p_stops = 0; 2174 /* from procfs_ioctl.c: PIOCCONT */ 2175 p->p_step = 0; 2176 wakeup(&p->p_step); 2177 } 2178 /* 2179 * Some signals have a process-wide effect and a per-thread 2180 * component. Most processing occurs when the process next 2181 * tries to cross the user boundary, however there are some 2182 * times when processing needs to be done immediately, such as 2183 * waking up threads so that they can cross the user boundary. 2184 * We try to do the per-process part here. 2185 */ 2186 if (P_SHOULDSTOP(p)) { 2187 KASSERT(!(p->p_flag & P_WEXIT), 2188 ("signal to stopped but exiting process")); 2189 if (sig == SIGKILL) { 2190 /* 2191 * If traced process is already stopped, 2192 * then no further action is necessary. 2193 */ 2194 if (p->p_flag & P_TRACED) 2195 goto out; 2196 /* 2197 * SIGKILL sets process running. 2198 * It will die elsewhere. 2199 * All threads must be restarted. 2200 */ 2201 p->p_flag &= ~P_STOPPED_SIG; 2202 goto runfast; 2203 } 2204 2205 if (prop & SA_CONT) { 2206 /* 2207 * If traced process is already stopped, 2208 * then no further action is necessary. 2209 */ 2210 if (p->p_flag & P_TRACED) 2211 goto out; 2212 /* 2213 * If SIGCONT is default (or ignored), we continue the 2214 * process but don't leave the signal in sigqueue as 2215 * it has no further action. If SIGCONT is held, we 2216 * continue the process and leave the signal in 2217 * sigqueue. If the process catches SIGCONT, let it 2218 * handle the signal itself. If it isn't waiting on 2219 * an event, it goes back to run state. 2220 * Otherwise, process goes back to sleep state. 2221 */ 2222 p->p_flag &= ~P_STOPPED_SIG; 2223 PROC_SLOCK(p); 2224 if (p->p_numthreads == p->p_suspcount) { 2225 PROC_SUNLOCK(p); 2226 p->p_flag |= P_CONTINUED; 2227 p->p_xstat = SIGCONT; 2228 PROC_LOCK(p->p_pptr); 2229 childproc_continued(p); 2230 PROC_UNLOCK(p->p_pptr); 2231 PROC_SLOCK(p); 2232 } 2233 if (action == SIG_DFL) { 2234 thread_unsuspend(p); 2235 PROC_SUNLOCK(p); 2236 sigqueue_delete(sigqueue, sig); 2237 goto out; 2238 } 2239 if (action == SIG_CATCH) { 2240 /* 2241 * The process wants to catch it so it needs 2242 * to run at least one thread, but which one? 2243 */ 2244 PROC_SUNLOCK(p); 2245 goto runfast; 2246 } 2247 /* 2248 * The signal is not ignored or caught. 2249 */ 2250 thread_unsuspend(p); 2251 PROC_SUNLOCK(p); 2252 goto out; 2253 } 2254 2255 if (prop & SA_STOP) { 2256 /* 2257 * If traced process is already stopped, 2258 * then no further action is necessary. 2259 */ 2260 if (p->p_flag & P_TRACED) 2261 goto out; 2262 /* 2263 * Already stopped, don't need to stop again 2264 * (If we did the shell could get confused). 2265 * Just make sure the signal STOP bit set. 2266 */ 2267 p->p_flag |= P_STOPPED_SIG; 2268 sigqueue_delete(sigqueue, sig); 2269 goto out; 2270 } 2271 2272 /* 2273 * All other kinds of signals: 2274 * If a thread is sleeping interruptibly, simulate a 2275 * wakeup so that when it is continued it will be made 2276 * runnable and can look at the signal. However, don't make 2277 * the PROCESS runnable, leave it stopped. 2278 * It may run a bit until it hits a thread_suspend_check(). 2279 */ 2280 wakeup_swapper = 0; 2281 PROC_SLOCK(p); 2282 thread_lock(td); 2283 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2284 wakeup_swapper = sleepq_abort(td, intrval); 2285 thread_unlock(td); 2286 PROC_SUNLOCK(p); 2287 if (wakeup_swapper) 2288 kick_proc0(); 2289 goto out; 2290 /* 2291 * Mutexes are short lived. Threads waiting on them will 2292 * hit thread_suspend_check() soon. 2293 */ 2294 } else if (p->p_state == PRS_NORMAL) { 2295 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2296 tdsigwakeup(td, sig, action, intrval); 2297 goto out; 2298 } 2299 2300 MPASS(action == SIG_DFL); 2301 2302 if (prop & SA_STOP) { 2303 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2304 goto out; 2305 p->p_flag |= P_STOPPED_SIG; 2306 p->p_xstat = sig; 2307 PROC_SLOCK(p); 2308 sig_suspend_threads(td, p, 1); 2309 if (p->p_numthreads == p->p_suspcount) { 2310 /* 2311 * only thread sending signal to another 2312 * process can reach here, if thread is sending 2313 * signal to its process, because thread does 2314 * not suspend itself here, p_numthreads 2315 * should never be equal to p_suspcount. 2316 */ 2317 thread_stopped(p); 2318 PROC_SUNLOCK(p); 2319 sigqueue_delete_proc(p, p->p_xstat); 2320 } else 2321 PROC_SUNLOCK(p); 2322 goto out; 2323 } 2324 } else { 2325 /* Not in "NORMAL" state. discard the signal. */ 2326 sigqueue_delete(sigqueue, sig); 2327 goto out; 2328 } 2329 2330 /* 2331 * The process is not stopped so we need to apply the signal to all the 2332 * running threads. 2333 */ 2334 runfast: 2335 tdsigwakeup(td, sig, action, intrval); 2336 PROC_SLOCK(p); 2337 thread_unsuspend(p); 2338 PROC_SUNLOCK(p); 2339 out: 2340 /* If we jump here, proc slock should not be owned. */ 2341 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2342 return (ret); 2343 } 2344 2345 /* 2346 * The force of a signal has been directed against a single 2347 * thread. We need to see what we can do about knocking it 2348 * out of any sleep it may be in etc. 2349 */ 2350 static void 2351 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2352 { 2353 struct proc *p = td->td_proc; 2354 register int prop; 2355 int wakeup_swapper; 2356 2357 wakeup_swapper = 0; 2358 PROC_LOCK_ASSERT(p, MA_OWNED); 2359 prop = sigprop(sig); 2360 2361 PROC_SLOCK(p); 2362 thread_lock(td); 2363 /* 2364 * Bring the priority of a thread up if we want it to get 2365 * killed in this lifetime. 2366 */ 2367 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2368 sched_prio(td, PUSER); 2369 if (TD_ON_SLEEPQ(td)) { 2370 /* 2371 * If thread is sleeping uninterruptibly 2372 * we can't interrupt the sleep... the signal will 2373 * be noticed when the process returns through 2374 * trap() or syscall(). 2375 */ 2376 if ((td->td_flags & TDF_SINTR) == 0) 2377 goto out; 2378 /* 2379 * If SIGCONT is default (or ignored) and process is 2380 * asleep, we are finished; the process should not 2381 * be awakened. 2382 */ 2383 if ((prop & SA_CONT) && action == SIG_DFL) { 2384 thread_unlock(td); 2385 PROC_SUNLOCK(p); 2386 sigqueue_delete(&p->p_sigqueue, sig); 2387 /* 2388 * It may be on either list in this state. 2389 * Remove from both for now. 2390 */ 2391 sigqueue_delete(&td->td_sigqueue, sig); 2392 return; 2393 } 2394 2395 /* 2396 * Don't awaken a sleeping thread for SIGSTOP if the 2397 * STOP signal is deferred. 2398 */ 2399 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2400 goto out; 2401 2402 /* 2403 * Give low priority threads a better chance to run. 2404 */ 2405 if (td->td_priority > PUSER) 2406 sched_prio(td, PUSER); 2407 2408 wakeup_swapper = sleepq_abort(td, intrval); 2409 } else { 2410 /* 2411 * Other states do nothing with the signal immediately, 2412 * other than kicking ourselves if we are running. 2413 * It will either never be noticed, or noticed very soon. 2414 */ 2415 #ifdef SMP 2416 if (TD_IS_RUNNING(td) && td != curthread) 2417 forward_signal(td); 2418 #endif 2419 } 2420 out: 2421 PROC_SUNLOCK(p); 2422 thread_unlock(td); 2423 if (wakeup_swapper) 2424 kick_proc0(); 2425 } 2426 2427 static void 2428 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2429 { 2430 struct thread *td2; 2431 2432 PROC_LOCK_ASSERT(p, MA_OWNED); 2433 PROC_SLOCK_ASSERT(p, MA_OWNED); 2434 2435 FOREACH_THREAD_IN_PROC(p, td2) { 2436 thread_lock(td2); 2437 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2438 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2439 (td2->td_flags & TDF_SINTR)) { 2440 if (td2->td_flags & TDF_SBDRY) { 2441 /* 2442 * Once a thread is asleep with 2443 * TDF_SBDRY set, it should never 2444 * become suspended due to this check. 2445 */ 2446 KASSERT(!TD_IS_SUSPENDED(td2), 2447 ("thread with deferred stops suspended")); 2448 } else if (!TD_IS_SUSPENDED(td2)) { 2449 thread_suspend_one(td2); 2450 } 2451 } else if (!TD_IS_SUSPENDED(td2)) { 2452 if (sending || td != td2) 2453 td2->td_flags |= TDF_ASTPENDING; 2454 #ifdef SMP 2455 if (TD_IS_RUNNING(td2) && td2 != td) 2456 forward_signal(td2); 2457 #endif 2458 } 2459 thread_unlock(td2); 2460 } 2461 } 2462 2463 int 2464 ptracestop(struct thread *td, int sig) 2465 { 2466 struct proc *p = td->td_proc; 2467 2468 PROC_LOCK_ASSERT(p, MA_OWNED); 2469 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2470 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2471 &p->p_mtx.lock_object, "Stopping for traced signal"); 2472 2473 td->td_dbgflags |= TDB_XSIG; 2474 td->td_xsig = sig; 2475 PROC_SLOCK(p); 2476 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2477 if (p->p_flag & P_SINGLE_EXIT) { 2478 td->td_dbgflags &= ~TDB_XSIG; 2479 PROC_SUNLOCK(p); 2480 return (sig); 2481 } 2482 /* 2483 * Just make wait() to work, the last stopped thread 2484 * will win. 2485 */ 2486 p->p_xstat = sig; 2487 p->p_xthread = td; 2488 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2489 sig_suspend_threads(td, p, 0); 2490 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2491 td->td_dbgflags &= ~TDB_STOPATFORK; 2492 cv_broadcast(&p->p_dbgwait); 2493 } 2494 stopme: 2495 thread_suspend_switch(td, p); 2496 if (p->p_xthread == td) 2497 p->p_xthread = NULL; 2498 if (!(p->p_flag & P_TRACED)) 2499 break; 2500 if (td->td_dbgflags & TDB_SUSPEND) { 2501 if (p->p_flag & P_SINGLE_EXIT) 2502 break; 2503 goto stopme; 2504 } 2505 } 2506 PROC_SUNLOCK(p); 2507 return (td->td_xsig); 2508 } 2509 2510 static void 2511 reschedule_signals(struct proc *p, sigset_t block, int flags) 2512 { 2513 struct sigacts *ps; 2514 struct thread *td; 2515 int sig; 2516 2517 PROC_LOCK_ASSERT(p, MA_OWNED); 2518 ps = p->p_sigacts; 2519 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2520 MA_OWNED : MA_NOTOWNED); 2521 if (SIGISEMPTY(p->p_siglist)) 2522 return; 2523 SIGSETAND(block, p->p_siglist); 2524 while ((sig = sig_ffs(&block)) != 0) { 2525 SIGDELSET(block, sig); 2526 td = sigtd(p, sig, 0); 2527 signotify(td); 2528 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2529 mtx_lock(&ps->ps_mtx); 2530 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2531 tdsigwakeup(td, sig, SIG_CATCH, 2532 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2533 ERESTART)); 2534 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2535 mtx_unlock(&ps->ps_mtx); 2536 } 2537 } 2538 2539 void 2540 tdsigcleanup(struct thread *td) 2541 { 2542 struct proc *p; 2543 sigset_t unblocked; 2544 2545 p = td->td_proc; 2546 PROC_LOCK_ASSERT(p, MA_OWNED); 2547 2548 sigqueue_flush(&td->td_sigqueue); 2549 if (p->p_numthreads == 1) 2550 return; 2551 2552 /* 2553 * Since we cannot handle signals, notify signal post code 2554 * about this by filling the sigmask. 2555 * 2556 * Also, if needed, wake up thread(s) that do not block the 2557 * same signals as the exiting thread, since the thread might 2558 * have been selected for delivery and woken up. 2559 */ 2560 SIGFILLSET(unblocked); 2561 SIGSETNAND(unblocked, td->td_sigmask); 2562 SIGFILLSET(td->td_sigmask); 2563 reschedule_signals(p, unblocked, 0); 2564 2565 } 2566 2567 /* 2568 * Defer the delivery of SIGSTOP for the current thread. Returns true 2569 * if stops were deferred and false if they were already deferred. 2570 */ 2571 int 2572 sigdeferstop(void) 2573 { 2574 struct thread *td; 2575 2576 td = curthread; 2577 if (td->td_flags & TDF_SBDRY) 2578 return (0); 2579 thread_lock(td); 2580 td->td_flags |= TDF_SBDRY; 2581 thread_unlock(td); 2582 return (1); 2583 } 2584 2585 /* 2586 * Permit the delivery of SIGSTOP for the current thread. This does 2587 * not immediately suspend if a stop was posted. Instead, the thread 2588 * will suspend either via ast() or a subsequent interruptible sleep. 2589 */ 2590 int 2591 sigallowstop(void) 2592 { 2593 struct thread *td; 2594 int prev; 2595 2596 td = curthread; 2597 thread_lock(td); 2598 prev = (td->td_flags & TDF_SBDRY) != 0; 2599 td->td_flags &= ~TDF_SBDRY; 2600 thread_unlock(td); 2601 return (prev); 2602 } 2603 2604 /* 2605 * If the current process has received a signal (should be caught or cause 2606 * termination, should interrupt current syscall), return the signal number. 2607 * Stop signals with default action are processed immediately, then cleared; 2608 * they aren't returned. This is checked after each entry to the system for 2609 * a syscall or trap (though this can usually be done without calling issignal 2610 * by checking the pending signal masks in cursig.) The normal call 2611 * sequence is 2612 * 2613 * while (sig = cursig(curthread)) 2614 * postsig(sig); 2615 */ 2616 static int 2617 issignal(struct thread *td) 2618 { 2619 struct proc *p; 2620 struct sigacts *ps; 2621 struct sigqueue *queue; 2622 sigset_t sigpending; 2623 int sig, prop, newsig; 2624 2625 p = td->td_proc; 2626 ps = p->p_sigacts; 2627 mtx_assert(&ps->ps_mtx, MA_OWNED); 2628 PROC_LOCK_ASSERT(p, MA_OWNED); 2629 for (;;) { 2630 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2631 2632 sigpending = td->td_sigqueue.sq_signals; 2633 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2634 SIGSETNAND(sigpending, td->td_sigmask); 2635 2636 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2637 SIG_STOPSIGMASK(sigpending); 2638 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2639 return (0); 2640 sig = sig_ffs(&sigpending); 2641 2642 if (p->p_stops & S_SIG) { 2643 mtx_unlock(&ps->ps_mtx); 2644 stopevent(p, S_SIG, sig); 2645 mtx_lock(&ps->ps_mtx); 2646 } 2647 2648 /* 2649 * We should see pending but ignored signals 2650 * only if P_TRACED was on when they were posted. 2651 */ 2652 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2653 sigqueue_delete(&td->td_sigqueue, sig); 2654 sigqueue_delete(&p->p_sigqueue, sig); 2655 continue; 2656 } 2657 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2658 /* 2659 * If traced, always stop. 2660 * Remove old signal from queue before the stop. 2661 * XXX shrug off debugger, it causes siginfo to 2662 * be thrown away. 2663 */ 2664 queue = &td->td_sigqueue; 2665 td->td_dbgksi.ksi_signo = 0; 2666 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2667 queue = &p->p_sigqueue; 2668 sigqueue_get(queue, sig, &td->td_dbgksi); 2669 } 2670 2671 mtx_unlock(&ps->ps_mtx); 2672 newsig = ptracestop(td, sig); 2673 mtx_lock(&ps->ps_mtx); 2674 2675 if (sig != newsig) { 2676 2677 /* 2678 * If parent wants us to take the signal, 2679 * then it will leave it in p->p_xstat; 2680 * otherwise we just look for signals again. 2681 */ 2682 if (newsig == 0) 2683 continue; 2684 sig = newsig; 2685 2686 /* 2687 * Put the new signal into td_sigqueue. If the 2688 * signal is being masked, look for other 2689 * signals. 2690 */ 2691 sigqueue_add(queue, sig, NULL); 2692 if (SIGISMEMBER(td->td_sigmask, sig)) 2693 continue; 2694 signotify(td); 2695 } else { 2696 if (td->td_dbgksi.ksi_signo != 0) { 2697 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2698 if (sigqueue_add(&td->td_sigqueue, sig, 2699 &td->td_dbgksi) != 0) 2700 td->td_dbgksi.ksi_signo = 0; 2701 } 2702 if (td->td_dbgksi.ksi_signo == 0) 2703 sigqueue_add(&td->td_sigqueue, sig, 2704 NULL); 2705 } 2706 2707 /* 2708 * If the traced bit got turned off, go back up 2709 * to the top to rescan signals. This ensures 2710 * that p_sig* and p_sigact are consistent. 2711 */ 2712 if ((p->p_flag & P_TRACED) == 0) 2713 continue; 2714 } 2715 2716 prop = sigprop(sig); 2717 2718 /* 2719 * Decide whether the signal should be returned. 2720 * Return the signal's number, or fall through 2721 * to clear it from the pending mask. 2722 */ 2723 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2724 2725 case (intptr_t)SIG_DFL: 2726 /* 2727 * Don't take default actions on system processes. 2728 */ 2729 if (p->p_pid <= 1) { 2730 #ifdef DIAGNOSTIC 2731 /* 2732 * Are you sure you want to ignore SIGSEGV 2733 * in init? XXX 2734 */ 2735 printf("Process (pid %lu) got signal %d\n", 2736 (u_long)p->p_pid, sig); 2737 #endif 2738 break; /* == ignore */ 2739 } 2740 /* 2741 * If there is a pending stop signal to process 2742 * with default action, stop here, 2743 * then clear the signal. However, 2744 * if process is member of an orphaned 2745 * process group, ignore tty stop signals. 2746 */ 2747 if (prop & SA_STOP) { 2748 if (p->p_flag & (P_TRACED|P_WEXIT) || 2749 (p->p_pgrp->pg_jobc == 0 && 2750 prop & SA_TTYSTOP)) 2751 break; /* == ignore */ 2752 mtx_unlock(&ps->ps_mtx); 2753 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2754 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2755 p->p_flag |= P_STOPPED_SIG; 2756 p->p_xstat = sig; 2757 PROC_SLOCK(p); 2758 sig_suspend_threads(td, p, 0); 2759 thread_suspend_switch(td, p); 2760 PROC_SUNLOCK(p); 2761 mtx_lock(&ps->ps_mtx); 2762 break; 2763 } else if (prop & SA_IGNORE) { 2764 /* 2765 * Except for SIGCONT, shouldn't get here. 2766 * Default action is to ignore; drop it. 2767 */ 2768 break; /* == ignore */ 2769 } else 2770 return (sig); 2771 /*NOTREACHED*/ 2772 2773 case (intptr_t)SIG_IGN: 2774 /* 2775 * Masking above should prevent us ever trying 2776 * to take action on an ignored signal other 2777 * than SIGCONT, unless process is traced. 2778 */ 2779 if ((prop & SA_CONT) == 0 && 2780 (p->p_flag & P_TRACED) == 0) 2781 printf("issignal\n"); 2782 break; /* == ignore */ 2783 2784 default: 2785 /* 2786 * This signal has an action, let 2787 * postsig() process it. 2788 */ 2789 return (sig); 2790 } 2791 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2792 sigqueue_delete(&p->p_sigqueue, sig); 2793 } 2794 /* NOTREACHED */ 2795 } 2796 2797 void 2798 thread_stopped(struct proc *p) 2799 { 2800 int n; 2801 2802 PROC_LOCK_ASSERT(p, MA_OWNED); 2803 PROC_SLOCK_ASSERT(p, MA_OWNED); 2804 n = p->p_suspcount; 2805 if (p == curproc) 2806 n++; 2807 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2808 PROC_SUNLOCK(p); 2809 p->p_flag &= ~P_WAITED; 2810 PROC_LOCK(p->p_pptr); 2811 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2812 CLD_TRAPPED : CLD_STOPPED); 2813 PROC_UNLOCK(p->p_pptr); 2814 PROC_SLOCK(p); 2815 } 2816 } 2817 2818 /* 2819 * Take the action for the specified signal 2820 * from the current set of pending signals. 2821 */ 2822 int 2823 postsig(sig) 2824 register int sig; 2825 { 2826 struct thread *td = curthread; 2827 register struct proc *p = td->td_proc; 2828 struct sigacts *ps; 2829 sig_t action; 2830 ksiginfo_t ksi; 2831 sigset_t returnmask; 2832 2833 KASSERT(sig != 0, ("postsig")); 2834 2835 PROC_LOCK_ASSERT(p, MA_OWNED); 2836 ps = p->p_sigacts; 2837 mtx_assert(&ps->ps_mtx, MA_OWNED); 2838 ksiginfo_init(&ksi); 2839 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2840 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2841 return (0); 2842 ksi.ksi_signo = sig; 2843 if (ksi.ksi_code == SI_TIMER) 2844 itimer_accept(p, ksi.ksi_timerid, &ksi); 2845 action = ps->ps_sigact[_SIG_IDX(sig)]; 2846 #ifdef KTRACE 2847 if (KTRPOINT(td, KTR_PSIG)) 2848 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2849 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2850 #endif 2851 if (p->p_stops & S_SIG) { 2852 mtx_unlock(&ps->ps_mtx); 2853 stopevent(p, S_SIG, sig); 2854 mtx_lock(&ps->ps_mtx); 2855 } 2856 2857 if (action == SIG_DFL) { 2858 /* 2859 * Default action, where the default is to kill 2860 * the process. (Other cases were ignored above.) 2861 */ 2862 mtx_unlock(&ps->ps_mtx); 2863 sigexit(td, sig); 2864 /* NOTREACHED */ 2865 } else { 2866 /* 2867 * If we get here, the signal must be caught. 2868 */ 2869 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2870 ("postsig action")); 2871 /* 2872 * Set the new mask value and also defer further 2873 * occurrences of this signal. 2874 * 2875 * Special case: user has done a sigsuspend. Here the 2876 * current mask is not of interest, but rather the 2877 * mask from before the sigsuspend is what we want 2878 * restored after the signal processing is completed. 2879 */ 2880 if (td->td_pflags & TDP_OLDMASK) { 2881 returnmask = td->td_oldsigmask; 2882 td->td_pflags &= ~TDP_OLDMASK; 2883 } else 2884 returnmask = td->td_sigmask; 2885 2886 if (p->p_sig == sig) { 2887 p->p_code = 0; 2888 p->p_sig = 0; 2889 } 2890 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2891 postsig_done(sig, td, ps); 2892 } 2893 return (1); 2894 } 2895 2896 /* 2897 * Kill the current process for stated reason. 2898 */ 2899 void 2900 killproc(p, why) 2901 struct proc *p; 2902 char *why; 2903 { 2904 2905 PROC_LOCK_ASSERT(p, MA_OWNED); 2906 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2907 p->p_comm); 2908 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2909 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2910 p->p_flag |= P_WKILLED; 2911 kern_psignal(p, SIGKILL); 2912 } 2913 2914 /* 2915 * Force the current process to exit with the specified signal, dumping core 2916 * if appropriate. We bypass the normal tests for masked and caught signals, 2917 * allowing unrecoverable failures to terminate the process without changing 2918 * signal state. Mark the accounting record with the signal termination. 2919 * If dumping core, save the signal number for the debugger. Calls exit and 2920 * does not return. 2921 */ 2922 void 2923 sigexit(td, sig) 2924 struct thread *td; 2925 int sig; 2926 { 2927 struct proc *p = td->td_proc; 2928 2929 PROC_LOCK_ASSERT(p, MA_OWNED); 2930 p->p_acflag |= AXSIG; 2931 /* 2932 * We must be single-threading to generate a core dump. This 2933 * ensures that the registers in the core file are up-to-date. 2934 * Also, the ELF dump handler assumes that the thread list doesn't 2935 * change out from under it. 2936 * 2937 * XXX If another thread attempts to single-thread before us 2938 * (e.g. via fork()), we won't get a dump at all. 2939 */ 2940 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 2941 p->p_sig = sig; 2942 /* 2943 * Log signals which would cause core dumps 2944 * (Log as LOG_INFO to appease those who don't want 2945 * these messages.) 2946 * XXX : Todo, as well as euid, write out ruid too 2947 * Note that coredump() drops proc lock. 2948 */ 2949 if (coredump(td) == 0) 2950 sig |= WCOREFLAG; 2951 if (kern_logsigexit) 2952 log(LOG_INFO, 2953 "pid %d (%s), uid %d: exited on signal %d%s\n", 2954 p->p_pid, p->p_comm, 2955 td->td_ucred ? td->td_ucred->cr_uid : -1, 2956 sig &~ WCOREFLAG, 2957 sig & WCOREFLAG ? " (core dumped)" : ""); 2958 } else 2959 PROC_UNLOCK(p); 2960 exit1(td, W_EXITCODE(0, sig)); 2961 /* NOTREACHED */ 2962 } 2963 2964 /* 2965 * Send queued SIGCHLD to parent when child process's state 2966 * is changed. 2967 */ 2968 static void 2969 sigparent(struct proc *p, int reason, int status) 2970 { 2971 PROC_LOCK_ASSERT(p, MA_OWNED); 2972 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2973 2974 if (p->p_ksi != NULL) { 2975 p->p_ksi->ksi_signo = SIGCHLD; 2976 p->p_ksi->ksi_code = reason; 2977 p->p_ksi->ksi_status = status; 2978 p->p_ksi->ksi_pid = p->p_pid; 2979 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2980 if (KSI_ONQ(p->p_ksi)) 2981 return; 2982 } 2983 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2984 } 2985 2986 static void 2987 childproc_jobstate(struct proc *p, int reason, int sig) 2988 { 2989 struct sigacts *ps; 2990 2991 PROC_LOCK_ASSERT(p, MA_OWNED); 2992 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2993 2994 /* 2995 * Wake up parent sleeping in kern_wait(), also send 2996 * SIGCHLD to parent, but SIGCHLD does not guarantee 2997 * that parent will awake, because parent may masked 2998 * the signal. 2999 */ 3000 p->p_pptr->p_flag |= P_STATCHILD; 3001 wakeup(p->p_pptr); 3002 3003 ps = p->p_pptr->p_sigacts; 3004 mtx_lock(&ps->ps_mtx); 3005 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3006 mtx_unlock(&ps->ps_mtx); 3007 sigparent(p, reason, sig); 3008 } else 3009 mtx_unlock(&ps->ps_mtx); 3010 } 3011 3012 void 3013 childproc_stopped(struct proc *p, int reason) 3014 { 3015 /* p_xstat is a plain signal number, not a full wait() status here. */ 3016 childproc_jobstate(p, reason, p->p_xstat); 3017 } 3018 3019 void 3020 childproc_continued(struct proc *p) 3021 { 3022 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3023 } 3024 3025 void 3026 childproc_exited(struct proc *p) 3027 { 3028 int reason; 3029 int xstat = p->p_xstat; /* convert to int */ 3030 int status; 3031 3032 if (WCOREDUMP(xstat)) 3033 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3034 else if (WIFSIGNALED(xstat)) 3035 reason = CLD_KILLED, status = WTERMSIG(xstat); 3036 else 3037 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3038 /* 3039 * XXX avoid calling wakeup(p->p_pptr), the work is 3040 * done in exit1(). 3041 */ 3042 sigparent(p, reason, status); 3043 } 3044 3045 /* 3046 * We only have 1 character for the core count in the format 3047 * string, so the range will be 0-9 3048 */ 3049 #define MAX_NUM_CORES 10 3050 static int num_cores = 5; 3051 3052 static int 3053 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3054 { 3055 int error; 3056 int new_val; 3057 3058 new_val = num_cores; 3059 error = sysctl_handle_int(oidp, &new_val, 0, req); 3060 if (error != 0 || req->newptr == NULL) 3061 return (error); 3062 if (new_val > MAX_NUM_CORES) 3063 new_val = MAX_NUM_CORES; 3064 if (new_val < 0) 3065 new_val = 0; 3066 num_cores = new_val; 3067 return (0); 3068 } 3069 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3070 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3071 3072 #if defined(COMPRESS_USER_CORES) 3073 int compress_user_cores = 1; 3074 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3075 &compress_user_cores, 0, "Compression of user corefiles"); 3076 3077 int compress_user_cores_gzlevel = -1; /* default level */ 3078 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3079 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3080 3081 #define GZ_SUFFIX ".gz" 3082 #define GZ_SUFFIX_LEN 3 3083 #endif 3084 3085 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3086 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RWTUN, corefilename, 3087 sizeof(corefilename), "Process corefile name format string"); 3088 3089 /* 3090 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3091 * Expand the name described in corefilename, using name, uid, and pid 3092 * and open/create core file. 3093 * corefilename is a printf-like string, with three format specifiers: 3094 * %N name of process ("name") 3095 * %P process id (pid) 3096 * %U user id (uid) 3097 * For example, "%N.core" is the default; they can be disabled completely 3098 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3099 * This is controlled by the sysctl variable kern.corefile (see above). 3100 */ 3101 static int 3102 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3103 int compress, struct vnode **vpp, char **namep) 3104 { 3105 struct nameidata nd; 3106 struct sbuf sb; 3107 const char *format; 3108 char *hostname, *name; 3109 int indexpos, i, error, cmode, flags, oflags; 3110 3111 hostname = NULL; 3112 format = corefilename; 3113 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3114 indexpos = -1; 3115 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3116 for (i = 0; format[i] != '\0'; i++) { 3117 switch (format[i]) { 3118 case '%': /* Format character */ 3119 i++; 3120 switch (format[i]) { 3121 case '%': 3122 sbuf_putc(&sb, '%'); 3123 break; 3124 case 'H': /* hostname */ 3125 if (hostname == NULL) { 3126 hostname = malloc(MAXHOSTNAMELEN, 3127 M_TEMP, M_WAITOK); 3128 } 3129 getcredhostname(td->td_ucred, hostname, 3130 MAXHOSTNAMELEN); 3131 sbuf_printf(&sb, "%s", hostname); 3132 break; 3133 case 'I': /* autoincrementing index */ 3134 sbuf_printf(&sb, "0"); 3135 indexpos = sbuf_len(&sb) - 1; 3136 break; 3137 case 'N': /* process name */ 3138 sbuf_printf(&sb, "%s", comm); 3139 break; 3140 case 'P': /* process id */ 3141 sbuf_printf(&sb, "%u", pid); 3142 break; 3143 case 'U': /* user id */ 3144 sbuf_printf(&sb, "%u", uid); 3145 break; 3146 default: 3147 log(LOG_ERR, 3148 "Unknown format character %c in " 3149 "corename `%s'\n", format[i], format); 3150 break; 3151 } 3152 break; 3153 default: 3154 sbuf_putc(&sb, format[i]); 3155 break; 3156 } 3157 } 3158 free(hostname, M_TEMP); 3159 #ifdef COMPRESS_USER_CORES 3160 if (compress) 3161 sbuf_printf(&sb, GZ_SUFFIX); 3162 #endif 3163 if (sbuf_error(&sb) != 0) { 3164 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3165 "long\n", (long)pid, comm, (u_long)uid); 3166 sbuf_delete(&sb); 3167 free(name, M_TEMP); 3168 return (ENOMEM); 3169 } 3170 sbuf_finish(&sb); 3171 sbuf_delete(&sb); 3172 3173 cmode = S_IRUSR | S_IWUSR; 3174 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3175 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3176 3177 /* 3178 * If the core format has a %I in it, then we need to check 3179 * for existing corefiles before returning a name. 3180 * To do this we iterate over 0..num_cores to find a 3181 * non-existing core file name to use. 3182 */ 3183 if (indexpos != -1) { 3184 for (i = 0; i < num_cores; i++) { 3185 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3186 name[indexpos] = '0' + i; 3187 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3188 error = vn_open_cred(&nd, &flags, cmode, oflags, 3189 td->td_ucred, NULL); 3190 if (error) { 3191 if (error == EEXIST) 3192 continue; 3193 log(LOG_ERR, 3194 "pid %d (%s), uid (%u): Path `%s' failed " 3195 "on initial open test, error = %d\n", 3196 pid, comm, uid, name, error); 3197 } 3198 goto out; 3199 } 3200 } 3201 3202 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3203 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3204 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3205 out: 3206 if (error) { 3207 #ifdef AUDIT 3208 audit_proc_coredump(td, name, error); 3209 #endif 3210 free(name, M_TEMP); 3211 return (error); 3212 } 3213 NDFREE(&nd, NDF_ONLY_PNBUF); 3214 *vpp = nd.ni_vp; 3215 *namep = name; 3216 return (0); 3217 } 3218 3219 /* 3220 * Dump a process' core. The main routine does some 3221 * policy checking, and creates the name of the coredump; 3222 * then it passes on a vnode and a size limit to the process-specific 3223 * coredump routine if there is one; if there _is not_ one, it returns 3224 * ENOSYS; otherwise it returns the error from the process-specific routine. 3225 */ 3226 3227 static int 3228 coredump(struct thread *td) 3229 { 3230 struct proc *p = td->td_proc; 3231 struct ucred *cred = td->td_ucred; 3232 struct vnode *vp; 3233 struct flock lf; 3234 struct vattr vattr; 3235 int error, error1, locked; 3236 char *name; /* name of corefile */ 3237 void *rl_cookie; 3238 off_t limit; 3239 int compress; 3240 3241 #ifdef COMPRESS_USER_CORES 3242 compress = compress_user_cores; 3243 #else 3244 compress = 0; 3245 #endif 3246 PROC_LOCK_ASSERT(p, MA_OWNED); 3247 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3248 _STOPEVENT(p, S_CORE, 0); 3249 3250 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3251 (p->p_flag2 & P2_NOTRACE) != 0) { 3252 PROC_UNLOCK(p); 3253 return (EFAULT); 3254 } 3255 3256 /* 3257 * Note that the bulk of limit checking is done after 3258 * the corefile is created. The exception is if the limit 3259 * for corefiles is 0, in which case we don't bother 3260 * creating the corefile at all. This layout means that 3261 * a corefile is truncated instead of not being created, 3262 * if it is larger than the limit. 3263 */ 3264 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3265 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3266 PROC_UNLOCK(p); 3267 return (EFBIG); 3268 } 3269 PROC_UNLOCK(p); 3270 3271 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3272 &vp, &name); 3273 if (error != 0) 3274 return (error); 3275 3276 /* 3277 * Don't dump to non-regular files or files with links. 3278 * Do not dump into system files. 3279 */ 3280 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3281 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3282 VOP_UNLOCK(vp, 0); 3283 error = EFAULT; 3284 goto close; 3285 } 3286 3287 VOP_UNLOCK(vp, 0); 3288 3289 /* Postpone other writers, including core dumps of other processes. */ 3290 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3291 3292 lf.l_whence = SEEK_SET; 3293 lf.l_start = 0; 3294 lf.l_len = 0; 3295 lf.l_type = F_WRLCK; 3296 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3297 3298 VATTR_NULL(&vattr); 3299 vattr.va_size = 0; 3300 if (set_core_nodump_flag) 3301 vattr.va_flags = UF_NODUMP; 3302 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3303 VOP_SETATTR(vp, &vattr, cred); 3304 VOP_UNLOCK(vp, 0); 3305 PROC_LOCK(p); 3306 p->p_acflag |= ACORE; 3307 PROC_UNLOCK(p); 3308 3309 if (p->p_sysent->sv_coredump != NULL) { 3310 error = p->p_sysent->sv_coredump(td, vp, limit, 3311 compress ? IMGACT_CORE_COMPRESS : 0); 3312 } else { 3313 error = ENOSYS; 3314 } 3315 3316 if (locked) { 3317 lf.l_type = F_UNLCK; 3318 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3319 } 3320 vn_rangelock_unlock(vp, rl_cookie); 3321 close: 3322 error1 = vn_close(vp, FWRITE, cred, td); 3323 if (error == 0) 3324 error = error1; 3325 #ifdef AUDIT 3326 audit_proc_coredump(td, name, error); 3327 #endif 3328 free(name, M_TEMP); 3329 return (error); 3330 } 3331 3332 /* 3333 * Nonexistent system call-- signal process (may want to handle it). Flag 3334 * error in case process won't see signal immediately (blocked or ignored). 3335 */ 3336 #ifndef _SYS_SYSPROTO_H_ 3337 struct nosys_args { 3338 int dummy; 3339 }; 3340 #endif 3341 /* ARGSUSED */ 3342 int 3343 nosys(td, args) 3344 struct thread *td; 3345 struct nosys_args *args; 3346 { 3347 struct proc *p = td->td_proc; 3348 3349 PROC_LOCK(p); 3350 tdsignal(td, SIGSYS); 3351 PROC_UNLOCK(p); 3352 return (ENOSYS); 3353 } 3354 3355 /* 3356 * Send a SIGIO or SIGURG signal to a process or process group using stored 3357 * credentials rather than those of the current process. 3358 */ 3359 void 3360 pgsigio(sigiop, sig, checkctty) 3361 struct sigio **sigiop; 3362 int sig, checkctty; 3363 { 3364 ksiginfo_t ksi; 3365 struct sigio *sigio; 3366 3367 ksiginfo_init(&ksi); 3368 ksi.ksi_signo = sig; 3369 ksi.ksi_code = SI_KERNEL; 3370 3371 SIGIO_LOCK(); 3372 sigio = *sigiop; 3373 if (sigio == NULL) { 3374 SIGIO_UNLOCK(); 3375 return; 3376 } 3377 if (sigio->sio_pgid > 0) { 3378 PROC_LOCK(sigio->sio_proc); 3379 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3380 kern_psignal(sigio->sio_proc, sig); 3381 PROC_UNLOCK(sigio->sio_proc); 3382 } else if (sigio->sio_pgid < 0) { 3383 struct proc *p; 3384 3385 PGRP_LOCK(sigio->sio_pgrp); 3386 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3387 PROC_LOCK(p); 3388 if (p->p_state == PRS_NORMAL && 3389 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3390 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3391 kern_psignal(p, sig); 3392 PROC_UNLOCK(p); 3393 } 3394 PGRP_UNLOCK(sigio->sio_pgrp); 3395 } 3396 SIGIO_UNLOCK(); 3397 } 3398 3399 static int 3400 filt_sigattach(struct knote *kn) 3401 { 3402 struct proc *p = curproc; 3403 3404 kn->kn_ptr.p_proc = p; 3405 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3406 3407 knlist_add(&p->p_klist, kn, 0); 3408 3409 return (0); 3410 } 3411 3412 static void 3413 filt_sigdetach(struct knote *kn) 3414 { 3415 struct proc *p = kn->kn_ptr.p_proc; 3416 3417 knlist_remove(&p->p_klist, kn, 0); 3418 } 3419 3420 /* 3421 * signal knotes are shared with proc knotes, so we apply a mask to 3422 * the hint in order to differentiate them from process hints. This 3423 * could be avoided by using a signal-specific knote list, but probably 3424 * isn't worth the trouble. 3425 */ 3426 static int 3427 filt_signal(struct knote *kn, long hint) 3428 { 3429 3430 if (hint & NOTE_SIGNAL) { 3431 hint &= ~NOTE_SIGNAL; 3432 3433 if (kn->kn_id == hint) 3434 kn->kn_data++; 3435 } 3436 return (kn->kn_data != 0); 3437 } 3438 3439 struct sigacts * 3440 sigacts_alloc(void) 3441 { 3442 struct sigacts *ps; 3443 3444 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3445 refcount_init(&ps->ps_refcnt, 1); 3446 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3447 return (ps); 3448 } 3449 3450 void 3451 sigacts_free(struct sigacts *ps) 3452 { 3453 3454 if (refcount_release(&ps->ps_refcnt) == 0) 3455 return; 3456 mtx_destroy(&ps->ps_mtx); 3457 free(ps, M_SUBPROC); 3458 } 3459 3460 struct sigacts * 3461 sigacts_hold(struct sigacts *ps) 3462 { 3463 3464 refcount_acquire(&ps->ps_refcnt); 3465 return (ps); 3466 } 3467 3468 void 3469 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3470 { 3471 3472 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3473 mtx_lock(&src->ps_mtx); 3474 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3475 mtx_unlock(&src->ps_mtx); 3476 } 3477 3478 int 3479 sigacts_shared(struct sigacts *ps) 3480 { 3481 3482 return (ps->ps_refcnt > 1); 3483 } 3484