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