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