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_gzio.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/imgact.h> 56 #include <sys/kernel.h> 57 #include <sys/ktr.h> 58 #include <sys/ktrace.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mutex.h> 62 #include <sys/refcount.h> 63 #include <sys/namei.h> 64 #include <sys/proc.h> 65 #include <sys/procdesc.h> 66 #include <sys/posix4.h> 67 #include <sys/pioctl.h> 68 #include <sys/racct.h> 69 #include <sys/resourcevar.h> 70 #include <sys/sdt.h> 71 #include <sys/sbuf.h> 72 #include <sys/sleepqueue.h> 73 #include <sys/smp.h> 74 #include <sys/stat.h> 75 #include <sys/sx.h> 76 #include <sys/syscallsubr.h> 77 #include <sys/sysctl.h> 78 #include <sys/sysent.h> 79 #include <sys/syslog.h> 80 #include <sys/sysproto.h> 81 #include <sys/timers.h> 82 #include <sys/unistd.h> 83 #include <sys/wait.h> 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/uma.h> 87 88 #include <sys/jail.h> 89 90 #include <machine/cpu.h> 91 92 #include <security/audit/audit.h> 93 94 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 95 96 SDT_PROVIDER_DECLARE(proc); 97 SDT_PROBE_DEFINE3(proc, , , signal__send, 98 "struct thread *", "struct proc *", "int"); 99 SDT_PROBE_DEFINE2(proc, , , signal__clear, 100 "int", "ksiginfo_t *"); 101 SDT_PROBE_DEFINE3(proc, , , signal__discard, 102 "struct thread *", "struct proc *", "int"); 103 104 static int coredump(struct thread *); 105 static int killpg1(struct thread *td, int sig, int pgid, int all, 106 ksiginfo_t *ksi); 107 static int issignal(struct thread *td); 108 static int sigprop(int sig); 109 static void tdsigwakeup(struct thread *, int, sig_t, int); 110 static void sig_suspend_threads(struct thread *, struct proc *, int); 111 static int filt_sigattach(struct knote *kn); 112 static void filt_sigdetach(struct knote *kn); 113 static int filt_signal(struct knote *kn, long hint); 114 static struct thread *sigtd(struct proc *p, int sig, int prop); 115 static void sigqueue_start(void); 116 117 static uma_zone_t ksiginfo_zone = NULL; 118 struct filterops sig_filtops = { 119 .f_isfd = 0, 120 .f_attach = filt_sigattach, 121 .f_detach = filt_sigdetach, 122 .f_event = filt_signal, 123 }; 124 125 static int kern_logsigexit = 1; 126 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 127 &kern_logsigexit, 0, 128 "Log processes quitting on abnormal signals to syslog(3)"); 129 130 static int kern_forcesigexit = 1; 131 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 132 &kern_forcesigexit, 0, "Force trap signal to be handled"); 133 134 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 135 "POSIX real time signal"); 136 137 static int max_pending_per_proc = 128; 138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 139 &max_pending_per_proc, 0, "Max pending signals per proc"); 140 141 static int preallocate_siginfo = 1024; 142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 143 &preallocate_siginfo, 0, "Preallocated signal memory size"); 144 145 static int signal_overflow = 0; 146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 147 &signal_overflow, 0, "Number of signals overflew"); 148 149 static int signal_alloc_fail = 0; 150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 151 &signal_alloc_fail, 0, "signals failed to be allocated"); 152 153 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 154 155 /* 156 * Policy -- Can ucred cr1 send SIGIO to process cr2? 157 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 158 * in the right situations. 159 */ 160 #define CANSIGIO(cr1, cr2) \ 161 ((cr1)->cr_uid == 0 || \ 162 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 163 (cr1)->cr_uid == (cr2)->cr_ruid || \ 164 (cr1)->cr_ruid == (cr2)->cr_uid || \ 165 (cr1)->cr_uid == (cr2)->cr_uid) 166 167 static int sugid_coredump; 168 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 169 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 170 171 static int capmode_coredump; 172 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 173 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 174 175 static int do_coredump = 1; 176 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 177 &do_coredump, 0, "Enable/Disable coredumps"); 178 179 static int set_core_nodump_flag = 0; 180 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 181 0, "Enable setting the NODUMP flag on coredump files"); 182 183 static int coredump_devctl = 0; 184 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 185 0, "Generate a devctl notification when processes coredump"); 186 187 /* 188 * Signal properties and actions. 189 * The array below categorizes the signals and their default actions 190 * according to the following properties: 191 */ 192 #define SA_KILL 0x01 /* terminates process by default */ 193 #define SA_CORE 0x02 /* ditto and coredumps */ 194 #define SA_STOP 0x04 /* suspend process */ 195 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 196 #define SA_IGNORE 0x10 /* ignore by default */ 197 #define SA_CONT 0x20 /* continue if suspended */ 198 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 199 200 static int sigproptbl[NSIG] = { 201 SA_KILL, /* SIGHUP */ 202 SA_KILL, /* SIGINT */ 203 SA_KILL|SA_CORE, /* SIGQUIT */ 204 SA_KILL|SA_CORE, /* SIGILL */ 205 SA_KILL|SA_CORE, /* SIGTRAP */ 206 SA_KILL|SA_CORE, /* SIGABRT */ 207 SA_KILL|SA_CORE, /* SIGEMT */ 208 SA_KILL|SA_CORE, /* SIGFPE */ 209 SA_KILL, /* SIGKILL */ 210 SA_KILL|SA_CORE, /* SIGBUS */ 211 SA_KILL|SA_CORE, /* SIGSEGV */ 212 SA_KILL|SA_CORE, /* SIGSYS */ 213 SA_KILL, /* SIGPIPE */ 214 SA_KILL, /* SIGALRM */ 215 SA_KILL, /* SIGTERM */ 216 SA_IGNORE, /* SIGURG */ 217 SA_STOP, /* SIGSTOP */ 218 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 219 SA_IGNORE|SA_CONT, /* SIGCONT */ 220 SA_IGNORE, /* SIGCHLD */ 221 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 222 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 223 SA_IGNORE, /* SIGIO */ 224 SA_KILL, /* SIGXCPU */ 225 SA_KILL, /* SIGXFSZ */ 226 SA_KILL, /* SIGVTALRM */ 227 SA_KILL, /* SIGPROF */ 228 SA_IGNORE, /* SIGWINCH */ 229 SA_IGNORE, /* SIGINFO */ 230 SA_KILL, /* SIGUSR1 */ 231 SA_KILL, /* SIGUSR2 */ 232 }; 233 234 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 235 236 static void 237 sigqueue_start(void) 238 { 239 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 240 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 241 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 242 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 243 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 244 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 245 } 246 247 ksiginfo_t * 248 ksiginfo_alloc(int wait) 249 { 250 int flags; 251 252 flags = M_ZERO; 253 if (! wait) 254 flags |= M_NOWAIT; 255 if (ksiginfo_zone != NULL) 256 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 257 return (NULL); 258 } 259 260 void 261 ksiginfo_free(ksiginfo_t *ksi) 262 { 263 uma_zfree(ksiginfo_zone, ksi); 264 } 265 266 static __inline int 267 ksiginfo_tryfree(ksiginfo_t *ksi) 268 { 269 if (!(ksi->ksi_flags & KSI_EXT)) { 270 uma_zfree(ksiginfo_zone, ksi); 271 return (1); 272 } 273 return (0); 274 } 275 276 void 277 sigqueue_init(sigqueue_t *list, struct proc *p) 278 { 279 SIGEMPTYSET(list->sq_signals); 280 SIGEMPTYSET(list->sq_kill); 281 TAILQ_INIT(&list->sq_list); 282 list->sq_proc = p; 283 list->sq_flags = SQ_INIT; 284 } 285 286 /* 287 * Get a signal's ksiginfo. 288 * Return: 289 * 0 - signal not found 290 * others - signal number 291 */ 292 static int 293 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 294 { 295 struct proc *p = sq->sq_proc; 296 struct ksiginfo *ksi, *next; 297 int count = 0; 298 299 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 300 301 if (!SIGISMEMBER(sq->sq_signals, signo)) 302 return (0); 303 304 if (SIGISMEMBER(sq->sq_kill, signo)) { 305 count++; 306 SIGDELSET(sq->sq_kill, signo); 307 } 308 309 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 310 if (ksi->ksi_signo == signo) { 311 if (count == 0) { 312 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 313 ksi->ksi_sigq = NULL; 314 ksiginfo_copy(ksi, si); 315 if (ksiginfo_tryfree(ksi) && p != NULL) 316 p->p_pendingcnt--; 317 } 318 if (++count > 1) 319 break; 320 } 321 } 322 323 if (count <= 1) 324 SIGDELSET(sq->sq_signals, signo); 325 si->ksi_signo = signo; 326 return (signo); 327 } 328 329 void 330 sigqueue_take(ksiginfo_t *ksi) 331 { 332 struct ksiginfo *kp; 333 struct proc *p; 334 sigqueue_t *sq; 335 336 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 337 return; 338 339 p = sq->sq_proc; 340 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 341 ksi->ksi_sigq = NULL; 342 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 343 p->p_pendingcnt--; 344 345 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 346 kp = TAILQ_NEXT(kp, ksi_link)) { 347 if (kp->ksi_signo == ksi->ksi_signo) 348 break; 349 } 350 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 351 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 352 } 353 354 static int 355 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 356 { 357 struct proc *p = sq->sq_proc; 358 struct ksiginfo *ksi; 359 int ret = 0; 360 361 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 362 363 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 364 SIGADDSET(sq->sq_kill, signo); 365 goto out_set_bit; 366 } 367 368 /* directly insert the ksi, don't copy it */ 369 if (si->ksi_flags & KSI_INS) { 370 if (si->ksi_flags & KSI_HEAD) 371 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 372 else 373 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 374 si->ksi_sigq = sq; 375 goto out_set_bit; 376 } 377 378 if (__predict_false(ksiginfo_zone == NULL)) { 379 SIGADDSET(sq->sq_kill, signo); 380 goto out_set_bit; 381 } 382 383 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 384 signal_overflow++; 385 ret = EAGAIN; 386 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 387 signal_alloc_fail++; 388 ret = EAGAIN; 389 } else { 390 if (p != NULL) 391 p->p_pendingcnt++; 392 ksiginfo_copy(si, ksi); 393 ksi->ksi_signo = signo; 394 if (si->ksi_flags & KSI_HEAD) 395 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 396 else 397 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 398 ksi->ksi_sigq = sq; 399 } 400 401 if ((si->ksi_flags & KSI_TRAP) != 0 || 402 (si->ksi_flags & KSI_SIGQ) == 0) { 403 if (ret != 0) 404 SIGADDSET(sq->sq_kill, signo); 405 ret = 0; 406 goto out_set_bit; 407 } 408 409 if (ret != 0) 410 return (ret); 411 412 out_set_bit: 413 SIGADDSET(sq->sq_signals, signo); 414 return (ret); 415 } 416 417 void 418 sigqueue_flush(sigqueue_t *sq) 419 { 420 struct proc *p = sq->sq_proc; 421 ksiginfo_t *ksi; 422 423 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 424 425 if (p != NULL) 426 PROC_LOCK_ASSERT(p, MA_OWNED); 427 428 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 429 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 430 ksi->ksi_sigq = NULL; 431 if (ksiginfo_tryfree(ksi) && p != NULL) 432 p->p_pendingcnt--; 433 } 434 435 SIGEMPTYSET(sq->sq_signals); 436 SIGEMPTYSET(sq->sq_kill); 437 } 438 439 static void 440 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 441 { 442 sigset_t tmp; 443 struct proc *p1, *p2; 444 ksiginfo_t *ksi, *next; 445 446 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 447 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 448 p1 = src->sq_proc; 449 p2 = dst->sq_proc; 450 /* Move siginfo to target list */ 451 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 452 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 453 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 454 if (p1 != NULL) 455 p1->p_pendingcnt--; 456 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 457 ksi->ksi_sigq = dst; 458 if (p2 != NULL) 459 p2->p_pendingcnt++; 460 } 461 } 462 463 /* Move pending bits to target list */ 464 tmp = src->sq_kill; 465 SIGSETAND(tmp, *set); 466 SIGSETOR(dst->sq_kill, tmp); 467 SIGSETNAND(src->sq_kill, tmp); 468 469 tmp = src->sq_signals; 470 SIGSETAND(tmp, *set); 471 SIGSETOR(dst->sq_signals, tmp); 472 SIGSETNAND(src->sq_signals, tmp); 473 } 474 475 #if 0 476 static void 477 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 478 { 479 sigset_t set; 480 481 SIGEMPTYSET(set); 482 SIGADDSET(set, signo); 483 sigqueue_move_set(src, dst, &set); 484 } 485 #endif 486 487 static void 488 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 489 { 490 struct proc *p = sq->sq_proc; 491 ksiginfo_t *ksi, *next; 492 493 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 494 495 /* Remove siginfo queue */ 496 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 497 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 498 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 499 ksi->ksi_sigq = NULL; 500 if (ksiginfo_tryfree(ksi) && p != NULL) 501 p->p_pendingcnt--; 502 } 503 } 504 SIGSETNAND(sq->sq_kill, *set); 505 SIGSETNAND(sq->sq_signals, *set); 506 } 507 508 void 509 sigqueue_delete(sigqueue_t *sq, int signo) 510 { 511 sigset_t set; 512 513 SIGEMPTYSET(set); 514 SIGADDSET(set, signo); 515 sigqueue_delete_set(sq, &set); 516 } 517 518 /* Remove a set of signals for a process */ 519 static void 520 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 521 { 522 sigqueue_t worklist; 523 struct thread *td0; 524 525 PROC_LOCK_ASSERT(p, MA_OWNED); 526 527 sigqueue_init(&worklist, NULL); 528 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 529 530 FOREACH_THREAD_IN_PROC(p, td0) 531 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 532 533 sigqueue_flush(&worklist); 534 } 535 536 void 537 sigqueue_delete_proc(struct proc *p, int signo) 538 { 539 sigset_t set; 540 541 SIGEMPTYSET(set); 542 SIGADDSET(set, signo); 543 sigqueue_delete_set_proc(p, &set); 544 } 545 546 static void 547 sigqueue_delete_stopmask_proc(struct proc *p) 548 { 549 sigset_t set; 550 551 SIGEMPTYSET(set); 552 SIGADDSET(set, SIGSTOP); 553 SIGADDSET(set, SIGTSTP); 554 SIGADDSET(set, SIGTTIN); 555 SIGADDSET(set, SIGTTOU); 556 sigqueue_delete_set_proc(p, &set); 557 } 558 559 /* 560 * Determine signal that should be delivered to thread td, the current 561 * thread, 0 if none. If there is a pending stop signal with default 562 * action, the process stops in issignal(). 563 */ 564 int 565 cursig(struct thread *td) 566 { 567 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 568 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 569 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 570 return (SIGPENDING(td) ? issignal(td) : 0); 571 } 572 573 /* 574 * Arrange for ast() to handle unmasked pending signals on return to user 575 * mode. This must be called whenever a signal is added to td_sigqueue or 576 * unmasked in td_sigmask. 577 */ 578 void 579 signotify(struct thread *td) 580 { 581 struct proc *p; 582 583 p = td->td_proc; 584 585 PROC_LOCK_ASSERT(p, MA_OWNED); 586 587 if (SIGPENDING(td)) { 588 thread_lock(td); 589 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 590 thread_unlock(td); 591 } 592 } 593 594 int 595 sigonstack(size_t sp) 596 { 597 struct thread *td = curthread; 598 599 return ((td->td_pflags & TDP_ALTSTACK) ? 600 #if defined(COMPAT_43) 601 ((td->td_sigstk.ss_size == 0) ? 602 (td->td_sigstk.ss_flags & SS_ONSTACK) : 603 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 604 #else 605 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 606 #endif 607 : 0); 608 } 609 610 static __inline int 611 sigprop(int sig) 612 { 613 614 if (sig > 0 && sig < NSIG) 615 return (sigproptbl[_SIG_IDX(sig)]); 616 return (0); 617 } 618 619 int 620 sig_ffs(sigset_t *set) 621 { 622 int i; 623 624 for (i = 0; i < _SIG_WORDS; i++) 625 if (set->__bits[i]) 626 return (ffs(set->__bits[i]) + (i * 32)); 627 return (0); 628 } 629 630 static bool 631 sigact_flag_test(const struct sigaction *act, int flag) 632 { 633 634 /* 635 * SA_SIGINFO is reset when signal disposition is set to 636 * ignore or default. Other flags are kept according to user 637 * settings. 638 */ 639 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 640 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 641 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 642 } 643 644 /* 645 * kern_sigaction 646 * sigaction 647 * freebsd4_sigaction 648 * osigaction 649 */ 650 int 651 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 652 struct sigaction *oact, int flags) 653 { 654 struct sigacts *ps; 655 struct proc *p = td->td_proc; 656 657 if (!_SIG_VALID(sig)) 658 return (EINVAL); 659 if (act != NULL && act->sa_handler != SIG_DFL && 660 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 661 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 662 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 663 return (EINVAL); 664 665 PROC_LOCK(p); 666 ps = p->p_sigacts; 667 mtx_lock(&ps->ps_mtx); 668 if (oact) { 669 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 670 oact->sa_flags = 0; 671 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 672 oact->sa_flags |= SA_ONSTACK; 673 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 674 oact->sa_flags |= SA_RESTART; 675 if (SIGISMEMBER(ps->ps_sigreset, sig)) 676 oact->sa_flags |= SA_RESETHAND; 677 if (SIGISMEMBER(ps->ps_signodefer, sig)) 678 oact->sa_flags |= SA_NODEFER; 679 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 680 oact->sa_flags |= SA_SIGINFO; 681 oact->sa_sigaction = 682 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 683 } else 684 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 685 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 686 oact->sa_flags |= SA_NOCLDSTOP; 687 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 688 oact->sa_flags |= SA_NOCLDWAIT; 689 } 690 if (act) { 691 if ((sig == SIGKILL || sig == SIGSTOP) && 692 act->sa_handler != SIG_DFL) { 693 mtx_unlock(&ps->ps_mtx); 694 PROC_UNLOCK(p); 695 return (EINVAL); 696 } 697 698 /* 699 * Change setting atomically. 700 */ 701 702 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 703 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 704 if (sigact_flag_test(act, SA_SIGINFO)) { 705 ps->ps_sigact[_SIG_IDX(sig)] = 706 (__sighandler_t *)act->sa_sigaction; 707 SIGADDSET(ps->ps_siginfo, sig); 708 } else { 709 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 710 SIGDELSET(ps->ps_siginfo, sig); 711 } 712 if (!sigact_flag_test(act, SA_RESTART)) 713 SIGADDSET(ps->ps_sigintr, sig); 714 else 715 SIGDELSET(ps->ps_sigintr, sig); 716 if (sigact_flag_test(act, SA_ONSTACK)) 717 SIGADDSET(ps->ps_sigonstack, sig); 718 else 719 SIGDELSET(ps->ps_sigonstack, sig); 720 if (sigact_flag_test(act, SA_RESETHAND)) 721 SIGADDSET(ps->ps_sigreset, sig); 722 else 723 SIGDELSET(ps->ps_sigreset, sig); 724 if (sigact_flag_test(act, SA_NODEFER)) 725 SIGADDSET(ps->ps_signodefer, sig); 726 else 727 SIGDELSET(ps->ps_signodefer, sig); 728 if (sig == SIGCHLD) { 729 if (act->sa_flags & SA_NOCLDSTOP) 730 ps->ps_flag |= PS_NOCLDSTOP; 731 else 732 ps->ps_flag &= ~PS_NOCLDSTOP; 733 if (act->sa_flags & SA_NOCLDWAIT) { 734 /* 735 * Paranoia: since SA_NOCLDWAIT is implemented 736 * by reparenting the dying child to PID 1 (and 737 * trust it to reap the zombie), PID 1 itself 738 * is forbidden to set SA_NOCLDWAIT. 739 */ 740 if (p->p_pid == 1) 741 ps->ps_flag &= ~PS_NOCLDWAIT; 742 else 743 ps->ps_flag |= PS_NOCLDWAIT; 744 } else 745 ps->ps_flag &= ~PS_NOCLDWAIT; 746 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 747 ps->ps_flag |= PS_CLDSIGIGN; 748 else 749 ps->ps_flag &= ~PS_CLDSIGIGN; 750 } 751 /* 752 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 753 * and for signals set to SIG_DFL where the default is to 754 * ignore. However, don't put SIGCONT in ps_sigignore, as we 755 * have to restart the process. 756 */ 757 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 758 (sigprop(sig) & SA_IGNORE && 759 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 760 /* never to be seen again */ 761 sigqueue_delete_proc(p, sig); 762 if (sig != SIGCONT) 763 /* easier in psignal */ 764 SIGADDSET(ps->ps_sigignore, sig); 765 SIGDELSET(ps->ps_sigcatch, sig); 766 } else { 767 SIGDELSET(ps->ps_sigignore, sig); 768 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 769 SIGDELSET(ps->ps_sigcatch, sig); 770 else 771 SIGADDSET(ps->ps_sigcatch, sig); 772 } 773 #ifdef COMPAT_FREEBSD4 774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 776 (flags & KSA_FREEBSD4) == 0) 777 SIGDELSET(ps->ps_freebsd4, sig); 778 else 779 SIGADDSET(ps->ps_freebsd4, sig); 780 #endif 781 #ifdef COMPAT_43 782 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 784 (flags & KSA_OSIGSET) == 0) 785 SIGDELSET(ps->ps_osigset, sig); 786 else 787 SIGADDSET(ps->ps_osigset, sig); 788 #endif 789 } 790 mtx_unlock(&ps->ps_mtx); 791 PROC_UNLOCK(p); 792 return (0); 793 } 794 795 #ifndef _SYS_SYSPROTO_H_ 796 struct sigaction_args { 797 int sig; 798 struct sigaction *act; 799 struct sigaction *oact; 800 }; 801 #endif 802 int 803 sys_sigaction(td, uap) 804 struct thread *td; 805 register struct sigaction_args *uap; 806 { 807 struct sigaction act, oact; 808 register struct sigaction *actp, *oactp; 809 int error; 810 811 actp = (uap->act != NULL) ? &act : NULL; 812 oactp = (uap->oact != NULL) ? &oact : NULL; 813 if (actp) { 814 error = copyin(uap->act, actp, sizeof(act)); 815 if (error) 816 return (error); 817 } 818 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 819 if (oactp && !error) 820 error = copyout(oactp, uap->oact, sizeof(oact)); 821 return (error); 822 } 823 824 #ifdef COMPAT_FREEBSD4 825 #ifndef _SYS_SYSPROTO_H_ 826 struct freebsd4_sigaction_args { 827 int sig; 828 struct sigaction *act; 829 struct sigaction *oact; 830 }; 831 #endif 832 int 833 freebsd4_sigaction(td, uap) 834 struct thread *td; 835 register struct freebsd4_sigaction_args *uap; 836 { 837 struct sigaction act, oact; 838 register struct sigaction *actp, *oactp; 839 int error; 840 841 842 actp = (uap->act != NULL) ? &act : NULL; 843 oactp = (uap->oact != NULL) ? &oact : NULL; 844 if (actp) { 845 error = copyin(uap->act, actp, sizeof(act)); 846 if (error) 847 return (error); 848 } 849 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 850 if (oactp && !error) 851 error = copyout(oactp, uap->oact, sizeof(oact)); 852 return (error); 853 } 854 #endif /* COMAPT_FREEBSD4 */ 855 856 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 857 #ifndef _SYS_SYSPROTO_H_ 858 struct osigaction_args { 859 int signum; 860 struct osigaction *nsa; 861 struct osigaction *osa; 862 }; 863 #endif 864 int 865 osigaction(td, uap) 866 struct thread *td; 867 register struct osigaction_args *uap; 868 { 869 struct osigaction sa; 870 struct sigaction nsa, osa; 871 register struct sigaction *nsap, *osap; 872 int error; 873 874 if (uap->signum <= 0 || uap->signum >= ONSIG) 875 return (EINVAL); 876 877 nsap = (uap->nsa != NULL) ? &nsa : NULL; 878 osap = (uap->osa != NULL) ? &osa : NULL; 879 880 if (nsap) { 881 error = copyin(uap->nsa, &sa, sizeof(sa)); 882 if (error) 883 return (error); 884 nsap->sa_handler = sa.sa_handler; 885 nsap->sa_flags = sa.sa_flags; 886 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 887 } 888 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 889 if (osap && !error) { 890 sa.sa_handler = osap->sa_handler; 891 sa.sa_flags = osap->sa_flags; 892 SIG2OSIG(osap->sa_mask, sa.sa_mask); 893 error = copyout(&sa, uap->osa, sizeof(sa)); 894 } 895 return (error); 896 } 897 898 #if !defined(__i386__) 899 /* Avoid replicating the same stub everywhere */ 900 int 901 osigreturn(td, uap) 902 struct thread *td; 903 struct osigreturn_args *uap; 904 { 905 906 return (nosys(td, (struct nosys_args *)uap)); 907 } 908 #endif 909 #endif /* COMPAT_43 */ 910 911 /* 912 * Initialize signal state for process 0; 913 * set to ignore signals that are ignored by default. 914 */ 915 void 916 siginit(p) 917 struct proc *p; 918 { 919 register int i; 920 struct sigacts *ps; 921 922 PROC_LOCK(p); 923 ps = p->p_sigacts; 924 mtx_lock(&ps->ps_mtx); 925 for (i = 1; i <= NSIG; i++) { 926 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 927 SIGADDSET(ps->ps_sigignore, i); 928 } 929 } 930 mtx_unlock(&ps->ps_mtx); 931 PROC_UNLOCK(p); 932 } 933 934 /* 935 * Reset specified signal to the default disposition. 936 */ 937 static void 938 sigdflt(struct sigacts *ps, int sig) 939 { 940 941 mtx_assert(&ps->ps_mtx, MA_OWNED); 942 SIGDELSET(ps->ps_sigcatch, sig); 943 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 944 SIGADDSET(ps->ps_sigignore, sig); 945 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 946 SIGDELSET(ps->ps_siginfo, sig); 947 } 948 949 /* 950 * Reset signals for an exec of the specified process. 951 */ 952 void 953 execsigs(struct proc *p) 954 { 955 sigset_t osigignore; 956 struct sigacts *ps; 957 int sig; 958 struct thread *td; 959 960 /* 961 * Reset caught signals. Held signals remain held 962 * through td_sigmask (unless they were caught, 963 * and are now ignored by default). 964 */ 965 PROC_LOCK_ASSERT(p, MA_OWNED); 966 td = FIRST_THREAD_IN_PROC(p); 967 ps = p->p_sigacts; 968 mtx_lock(&ps->ps_mtx); 969 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 970 sig = sig_ffs(&ps->ps_sigcatch); 971 sigdflt(ps, sig); 972 if ((sigprop(sig) & SA_IGNORE) != 0) 973 sigqueue_delete_proc(p, sig); 974 } 975 976 /* 977 * As CloudABI processes cannot modify signal handlers, fully 978 * reset all signals to their default behavior. Do ignore 979 * SIGPIPE, as it would otherwise be impossible to recover from 980 * writes to broken pipes and sockets. 981 */ 982 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 983 osigignore = ps->ps_sigignore; 984 while (SIGNOTEMPTY(osigignore)) { 985 sig = sig_ffs(&osigignore); 986 SIGDELSET(osigignore, sig); 987 if (sig != SIGPIPE) 988 sigdflt(ps, sig); 989 } 990 SIGADDSET(ps->ps_sigignore, SIGPIPE); 991 } 992 993 /* 994 * Reset stack state to the user stack. 995 * Clear set of signals caught on the signal stack. 996 */ 997 td->td_sigstk.ss_flags = SS_DISABLE; 998 td->td_sigstk.ss_size = 0; 999 td->td_sigstk.ss_sp = 0; 1000 td->td_pflags &= ~TDP_ALTSTACK; 1001 /* 1002 * Reset no zombies if child dies flag as Solaris does. 1003 */ 1004 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1005 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1006 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1007 mtx_unlock(&ps->ps_mtx); 1008 } 1009 1010 /* 1011 * kern_sigprocmask() 1012 * 1013 * Manipulate signal mask. 1014 */ 1015 int 1016 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1017 int flags) 1018 { 1019 sigset_t new_block, oset1; 1020 struct proc *p; 1021 int error; 1022 1023 p = td->td_proc; 1024 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1025 PROC_LOCK_ASSERT(p, MA_OWNED); 1026 else 1027 PROC_LOCK(p); 1028 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1029 ? MA_OWNED : MA_NOTOWNED); 1030 if (oset != NULL) 1031 *oset = td->td_sigmask; 1032 1033 error = 0; 1034 if (set != NULL) { 1035 switch (how) { 1036 case SIG_BLOCK: 1037 SIG_CANTMASK(*set); 1038 oset1 = td->td_sigmask; 1039 SIGSETOR(td->td_sigmask, *set); 1040 new_block = td->td_sigmask; 1041 SIGSETNAND(new_block, oset1); 1042 break; 1043 case SIG_UNBLOCK: 1044 SIGSETNAND(td->td_sigmask, *set); 1045 signotify(td); 1046 goto out; 1047 case SIG_SETMASK: 1048 SIG_CANTMASK(*set); 1049 oset1 = td->td_sigmask; 1050 if (flags & SIGPROCMASK_OLD) 1051 SIGSETLO(td->td_sigmask, *set); 1052 else 1053 td->td_sigmask = *set; 1054 new_block = td->td_sigmask; 1055 SIGSETNAND(new_block, oset1); 1056 signotify(td); 1057 break; 1058 default: 1059 error = EINVAL; 1060 goto out; 1061 } 1062 1063 /* 1064 * The new_block set contains signals that were not previously 1065 * blocked, but are blocked now. 1066 * 1067 * In case we block any signal that was not previously blocked 1068 * for td, and process has the signal pending, try to schedule 1069 * signal delivery to some thread that does not block the 1070 * signal, possibly waking it up. 1071 */ 1072 if (p->p_numthreads != 1) 1073 reschedule_signals(p, new_block, flags); 1074 } 1075 1076 out: 1077 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1078 PROC_UNLOCK(p); 1079 return (error); 1080 } 1081 1082 #ifndef _SYS_SYSPROTO_H_ 1083 struct sigprocmask_args { 1084 int how; 1085 const sigset_t *set; 1086 sigset_t *oset; 1087 }; 1088 #endif 1089 int 1090 sys_sigprocmask(td, uap) 1091 register struct thread *td; 1092 struct sigprocmask_args *uap; 1093 { 1094 sigset_t set, oset; 1095 sigset_t *setp, *osetp; 1096 int error; 1097 1098 setp = (uap->set != NULL) ? &set : NULL; 1099 osetp = (uap->oset != NULL) ? &oset : NULL; 1100 if (setp) { 1101 error = copyin(uap->set, setp, sizeof(set)); 1102 if (error) 1103 return (error); 1104 } 1105 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1106 if (osetp && !error) { 1107 error = copyout(osetp, uap->oset, sizeof(oset)); 1108 } 1109 return (error); 1110 } 1111 1112 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1113 #ifndef _SYS_SYSPROTO_H_ 1114 struct osigprocmask_args { 1115 int how; 1116 osigset_t mask; 1117 }; 1118 #endif 1119 int 1120 osigprocmask(td, uap) 1121 register struct thread *td; 1122 struct osigprocmask_args *uap; 1123 { 1124 sigset_t set, oset; 1125 int error; 1126 1127 OSIG2SIG(uap->mask, set); 1128 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1129 SIG2OSIG(oset, td->td_retval[0]); 1130 return (error); 1131 } 1132 #endif /* COMPAT_43 */ 1133 1134 int 1135 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1136 { 1137 ksiginfo_t ksi; 1138 sigset_t set; 1139 int error; 1140 1141 error = copyin(uap->set, &set, sizeof(set)); 1142 if (error) { 1143 td->td_retval[0] = error; 1144 return (0); 1145 } 1146 1147 error = kern_sigtimedwait(td, set, &ksi, NULL); 1148 if (error) { 1149 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1150 error = ERESTART; 1151 if (error == ERESTART) 1152 return (error); 1153 td->td_retval[0] = error; 1154 return (0); 1155 } 1156 1157 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1158 td->td_retval[0] = error; 1159 return (0); 1160 } 1161 1162 int 1163 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1164 { 1165 struct timespec ts; 1166 struct timespec *timeout; 1167 sigset_t set; 1168 ksiginfo_t ksi; 1169 int error; 1170 1171 if (uap->timeout) { 1172 error = copyin(uap->timeout, &ts, sizeof(ts)); 1173 if (error) 1174 return (error); 1175 1176 timeout = &ts; 1177 } else 1178 timeout = NULL; 1179 1180 error = copyin(uap->set, &set, sizeof(set)); 1181 if (error) 1182 return (error); 1183 1184 error = kern_sigtimedwait(td, set, &ksi, timeout); 1185 if (error) 1186 return (error); 1187 1188 if (uap->info) 1189 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1190 1191 if (error == 0) 1192 td->td_retval[0] = ksi.ksi_signo; 1193 return (error); 1194 } 1195 1196 int 1197 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1198 { 1199 ksiginfo_t ksi; 1200 sigset_t set; 1201 int error; 1202 1203 error = copyin(uap->set, &set, sizeof(set)); 1204 if (error) 1205 return (error); 1206 1207 error = kern_sigtimedwait(td, set, &ksi, NULL); 1208 if (error) 1209 return (error); 1210 1211 if (uap->info) 1212 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1213 1214 if (error == 0) 1215 td->td_retval[0] = ksi.ksi_signo; 1216 return (error); 1217 } 1218 1219 int 1220 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1221 struct timespec *timeout) 1222 { 1223 struct sigacts *ps; 1224 sigset_t saved_mask, new_block; 1225 struct proc *p; 1226 int error, sig, timo, timevalid = 0; 1227 struct timespec rts, ets, ts; 1228 struct timeval tv; 1229 1230 p = td->td_proc; 1231 error = 0; 1232 ets.tv_sec = 0; 1233 ets.tv_nsec = 0; 1234 1235 if (timeout != NULL) { 1236 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1237 timevalid = 1; 1238 getnanouptime(&rts); 1239 ets = rts; 1240 timespecadd(&ets, timeout); 1241 } 1242 } 1243 ksiginfo_init(ksi); 1244 /* Some signals can not be waited for. */ 1245 SIG_CANTMASK(waitset); 1246 ps = p->p_sigacts; 1247 PROC_LOCK(p); 1248 saved_mask = td->td_sigmask; 1249 SIGSETNAND(td->td_sigmask, waitset); 1250 for (;;) { 1251 mtx_lock(&ps->ps_mtx); 1252 sig = cursig(td); 1253 mtx_unlock(&ps->ps_mtx); 1254 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1255 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1256 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1257 error = 0; 1258 break; 1259 } 1260 } 1261 1262 if (error != 0) 1263 break; 1264 1265 /* 1266 * POSIX says this must be checked after looking for pending 1267 * signals. 1268 */ 1269 if (timeout != NULL) { 1270 if (!timevalid) { 1271 error = EINVAL; 1272 break; 1273 } 1274 getnanouptime(&rts); 1275 if (timespeccmp(&rts, &ets, >=)) { 1276 error = EAGAIN; 1277 break; 1278 } 1279 ts = ets; 1280 timespecsub(&ts, &rts); 1281 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1282 timo = tvtohz(&tv); 1283 } else { 1284 timo = 0; 1285 } 1286 1287 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1288 1289 if (timeout != NULL) { 1290 if (error == ERESTART) { 1291 /* Timeout can not be restarted. */ 1292 error = EINTR; 1293 } else if (error == EAGAIN) { 1294 /* We will calculate timeout by ourself. */ 1295 error = 0; 1296 } 1297 } 1298 } 1299 1300 new_block = saved_mask; 1301 SIGSETNAND(new_block, td->td_sigmask); 1302 td->td_sigmask = saved_mask; 1303 /* 1304 * Fewer signals can be delivered to us, reschedule signal 1305 * notification. 1306 */ 1307 if (p->p_numthreads != 1) 1308 reschedule_signals(p, new_block, 0); 1309 1310 if (error == 0) { 1311 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1312 1313 if (ksi->ksi_code == SI_TIMER) 1314 itimer_accept(p, ksi->ksi_timerid, ksi); 1315 1316 #ifdef KTRACE 1317 if (KTRPOINT(td, KTR_PSIG)) { 1318 sig_t action; 1319 1320 mtx_lock(&ps->ps_mtx); 1321 action = ps->ps_sigact[_SIG_IDX(sig)]; 1322 mtx_unlock(&ps->ps_mtx); 1323 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1324 } 1325 #endif 1326 if (sig == SIGKILL) 1327 sigexit(td, sig); 1328 } 1329 PROC_UNLOCK(p); 1330 return (error); 1331 } 1332 1333 #ifndef _SYS_SYSPROTO_H_ 1334 struct sigpending_args { 1335 sigset_t *set; 1336 }; 1337 #endif 1338 int 1339 sys_sigpending(td, uap) 1340 struct thread *td; 1341 struct sigpending_args *uap; 1342 { 1343 struct proc *p = td->td_proc; 1344 sigset_t pending; 1345 1346 PROC_LOCK(p); 1347 pending = p->p_sigqueue.sq_signals; 1348 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1349 PROC_UNLOCK(p); 1350 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1351 } 1352 1353 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1354 #ifndef _SYS_SYSPROTO_H_ 1355 struct osigpending_args { 1356 int dummy; 1357 }; 1358 #endif 1359 int 1360 osigpending(td, uap) 1361 struct thread *td; 1362 struct osigpending_args *uap; 1363 { 1364 struct proc *p = td->td_proc; 1365 sigset_t pending; 1366 1367 PROC_LOCK(p); 1368 pending = p->p_sigqueue.sq_signals; 1369 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1370 PROC_UNLOCK(p); 1371 SIG2OSIG(pending, td->td_retval[0]); 1372 return (0); 1373 } 1374 #endif /* COMPAT_43 */ 1375 1376 #if defined(COMPAT_43) 1377 /* 1378 * Generalized interface signal handler, 4.3-compatible. 1379 */ 1380 #ifndef _SYS_SYSPROTO_H_ 1381 struct osigvec_args { 1382 int signum; 1383 struct sigvec *nsv; 1384 struct sigvec *osv; 1385 }; 1386 #endif 1387 /* ARGSUSED */ 1388 int 1389 osigvec(td, uap) 1390 struct thread *td; 1391 register struct osigvec_args *uap; 1392 { 1393 struct sigvec vec; 1394 struct sigaction nsa, osa; 1395 register struct sigaction *nsap, *osap; 1396 int error; 1397 1398 if (uap->signum <= 0 || uap->signum >= ONSIG) 1399 return (EINVAL); 1400 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1401 osap = (uap->osv != NULL) ? &osa : NULL; 1402 if (nsap) { 1403 error = copyin(uap->nsv, &vec, sizeof(vec)); 1404 if (error) 1405 return (error); 1406 nsap->sa_handler = vec.sv_handler; 1407 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1408 nsap->sa_flags = vec.sv_flags; 1409 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1410 } 1411 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1412 if (osap && !error) { 1413 vec.sv_handler = osap->sa_handler; 1414 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1415 vec.sv_flags = osap->sa_flags; 1416 vec.sv_flags &= ~SA_NOCLDWAIT; 1417 vec.sv_flags ^= SA_RESTART; 1418 error = copyout(&vec, uap->osv, sizeof(vec)); 1419 } 1420 return (error); 1421 } 1422 1423 #ifndef _SYS_SYSPROTO_H_ 1424 struct osigblock_args { 1425 int mask; 1426 }; 1427 #endif 1428 int 1429 osigblock(td, uap) 1430 register struct thread *td; 1431 struct osigblock_args *uap; 1432 { 1433 sigset_t set, oset; 1434 1435 OSIG2SIG(uap->mask, set); 1436 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1437 SIG2OSIG(oset, td->td_retval[0]); 1438 return (0); 1439 } 1440 1441 #ifndef _SYS_SYSPROTO_H_ 1442 struct osigsetmask_args { 1443 int mask; 1444 }; 1445 #endif 1446 int 1447 osigsetmask(td, uap) 1448 struct thread *td; 1449 struct osigsetmask_args *uap; 1450 { 1451 sigset_t set, oset; 1452 1453 OSIG2SIG(uap->mask, set); 1454 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1455 SIG2OSIG(oset, td->td_retval[0]); 1456 return (0); 1457 } 1458 #endif /* COMPAT_43 */ 1459 1460 /* 1461 * Suspend calling thread until signal, providing mask to be set in the 1462 * meantime. 1463 */ 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct sigsuspend_args { 1466 const sigset_t *sigmask; 1467 }; 1468 #endif 1469 /* ARGSUSED */ 1470 int 1471 sys_sigsuspend(td, uap) 1472 struct thread *td; 1473 struct sigsuspend_args *uap; 1474 { 1475 sigset_t mask; 1476 int error; 1477 1478 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1479 if (error) 1480 return (error); 1481 return (kern_sigsuspend(td, mask)); 1482 } 1483 1484 int 1485 kern_sigsuspend(struct thread *td, sigset_t mask) 1486 { 1487 struct proc *p = td->td_proc; 1488 int has_sig, sig; 1489 1490 /* 1491 * When returning from sigsuspend, we want 1492 * the old mask to be restored after the 1493 * signal handler has finished. Thus, we 1494 * save it here and mark the sigacts structure 1495 * to indicate this. 1496 */ 1497 PROC_LOCK(p); 1498 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1499 SIGPROCMASK_PROC_LOCKED); 1500 td->td_pflags |= TDP_OLDMASK; 1501 1502 /* 1503 * Process signals now. Otherwise, we can get spurious wakeup 1504 * due to signal entered process queue, but delivered to other 1505 * thread. But sigsuspend should return only on signal 1506 * delivery. 1507 */ 1508 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1509 for (has_sig = 0; !has_sig;) { 1510 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1511 0) == 0) 1512 /* void */; 1513 thread_suspend_check(0); 1514 mtx_lock(&p->p_sigacts->ps_mtx); 1515 while ((sig = cursig(td)) != 0) 1516 has_sig += postsig(sig); 1517 mtx_unlock(&p->p_sigacts->ps_mtx); 1518 } 1519 PROC_UNLOCK(p); 1520 td->td_errno = EINTR; 1521 td->td_pflags |= TDP_NERRNO; 1522 return (EJUSTRETURN); 1523 } 1524 1525 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1526 /* 1527 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1528 * convention: libc stub passes mask, not pointer, to save a copyin. 1529 */ 1530 #ifndef _SYS_SYSPROTO_H_ 1531 struct osigsuspend_args { 1532 osigset_t mask; 1533 }; 1534 #endif 1535 /* ARGSUSED */ 1536 int 1537 osigsuspend(td, uap) 1538 struct thread *td; 1539 struct osigsuspend_args *uap; 1540 { 1541 sigset_t mask; 1542 1543 OSIG2SIG(uap->mask, mask); 1544 return (kern_sigsuspend(td, mask)); 1545 } 1546 #endif /* COMPAT_43 */ 1547 1548 #if defined(COMPAT_43) 1549 #ifndef _SYS_SYSPROTO_H_ 1550 struct osigstack_args { 1551 struct sigstack *nss; 1552 struct sigstack *oss; 1553 }; 1554 #endif 1555 /* ARGSUSED */ 1556 int 1557 osigstack(td, uap) 1558 struct thread *td; 1559 register struct osigstack_args *uap; 1560 { 1561 struct sigstack nss, oss; 1562 int error = 0; 1563 1564 if (uap->nss != NULL) { 1565 error = copyin(uap->nss, &nss, sizeof(nss)); 1566 if (error) 1567 return (error); 1568 } 1569 oss.ss_sp = td->td_sigstk.ss_sp; 1570 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1571 if (uap->nss != NULL) { 1572 td->td_sigstk.ss_sp = nss.ss_sp; 1573 td->td_sigstk.ss_size = 0; 1574 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1575 td->td_pflags |= TDP_ALTSTACK; 1576 } 1577 if (uap->oss != NULL) 1578 error = copyout(&oss, uap->oss, sizeof(oss)); 1579 1580 return (error); 1581 } 1582 #endif /* COMPAT_43 */ 1583 1584 #ifndef _SYS_SYSPROTO_H_ 1585 struct sigaltstack_args { 1586 stack_t *ss; 1587 stack_t *oss; 1588 }; 1589 #endif 1590 /* ARGSUSED */ 1591 int 1592 sys_sigaltstack(td, uap) 1593 struct thread *td; 1594 register struct sigaltstack_args *uap; 1595 { 1596 stack_t ss, oss; 1597 int error; 1598 1599 if (uap->ss != NULL) { 1600 error = copyin(uap->ss, &ss, sizeof(ss)); 1601 if (error) 1602 return (error); 1603 } 1604 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1605 (uap->oss != NULL) ? &oss : NULL); 1606 if (error) 1607 return (error); 1608 if (uap->oss != NULL) 1609 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1610 return (error); 1611 } 1612 1613 int 1614 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1615 { 1616 struct proc *p = td->td_proc; 1617 int oonstack; 1618 1619 oonstack = sigonstack(cpu_getstack(td)); 1620 1621 if (oss != NULL) { 1622 *oss = td->td_sigstk; 1623 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1624 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1625 } 1626 1627 if (ss != NULL) { 1628 if (oonstack) 1629 return (EPERM); 1630 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1631 return (EINVAL); 1632 if (!(ss->ss_flags & SS_DISABLE)) { 1633 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1634 return (ENOMEM); 1635 1636 td->td_sigstk = *ss; 1637 td->td_pflags |= TDP_ALTSTACK; 1638 } else { 1639 td->td_pflags &= ~TDP_ALTSTACK; 1640 } 1641 } 1642 return (0); 1643 } 1644 1645 /* 1646 * Common code for kill process group/broadcast kill. 1647 * cp is calling process. 1648 */ 1649 static int 1650 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1651 { 1652 struct proc *p; 1653 struct pgrp *pgrp; 1654 int err; 1655 int ret; 1656 1657 ret = ESRCH; 1658 if (all) { 1659 /* 1660 * broadcast 1661 */ 1662 sx_slock(&allproc_lock); 1663 FOREACH_PROC_IN_SYSTEM(p) { 1664 PROC_LOCK(p); 1665 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1666 p == td->td_proc || p->p_state == PRS_NEW) { 1667 PROC_UNLOCK(p); 1668 continue; 1669 } 1670 err = p_cansignal(td, p, sig); 1671 if (err == 0) { 1672 if (sig) 1673 pksignal(p, sig, ksi); 1674 ret = err; 1675 } 1676 else if (ret == ESRCH) 1677 ret = err; 1678 PROC_UNLOCK(p); 1679 } 1680 sx_sunlock(&allproc_lock); 1681 } else { 1682 sx_slock(&proctree_lock); 1683 if (pgid == 0) { 1684 /* 1685 * zero pgid means send to my process group. 1686 */ 1687 pgrp = td->td_proc->p_pgrp; 1688 PGRP_LOCK(pgrp); 1689 } else { 1690 pgrp = pgfind(pgid); 1691 if (pgrp == NULL) { 1692 sx_sunlock(&proctree_lock); 1693 return (ESRCH); 1694 } 1695 } 1696 sx_sunlock(&proctree_lock); 1697 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1698 PROC_LOCK(p); 1699 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1700 p->p_state == PRS_NEW) { 1701 PROC_UNLOCK(p); 1702 continue; 1703 } 1704 err = p_cansignal(td, p, sig); 1705 if (err == 0) { 1706 if (sig) 1707 pksignal(p, sig, ksi); 1708 ret = err; 1709 } 1710 else if (ret == ESRCH) 1711 ret = err; 1712 PROC_UNLOCK(p); 1713 } 1714 PGRP_UNLOCK(pgrp); 1715 } 1716 return (ret); 1717 } 1718 1719 #ifndef _SYS_SYSPROTO_H_ 1720 struct kill_args { 1721 int pid; 1722 int signum; 1723 }; 1724 #endif 1725 /* ARGSUSED */ 1726 int 1727 sys_kill(struct thread *td, struct kill_args *uap) 1728 { 1729 ksiginfo_t ksi; 1730 struct proc *p; 1731 int error; 1732 1733 /* 1734 * A process in capability mode can send signals only to himself. 1735 * The main rationale behind this is that abort(3) is implemented as 1736 * kill(getpid(), SIGABRT). 1737 */ 1738 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1739 return (ECAPMODE); 1740 1741 AUDIT_ARG_SIGNUM(uap->signum); 1742 AUDIT_ARG_PID(uap->pid); 1743 if ((u_int)uap->signum > _SIG_MAXSIG) 1744 return (EINVAL); 1745 1746 ksiginfo_init(&ksi); 1747 ksi.ksi_signo = uap->signum; 1748 ksi.ksi_code = SI_USER; 1749 ksi.ksi_pid = td->td_proc->p_pid; 1750 ksi.ksi_uid = td->td_ucred->cr_ruid; 1751 1752 if (uap->pid > 0) { 1753 /* kill single process */ 1754 if ((p = pfind(uap->pid)) == NULL) { 1755 if ((p = zpfind(uap->pid)) == NULL) 1756 return (ESRCH); 1757 } 1758 AUDIT_ARG_PROCESS(p); 1759 error = p_cansignal(td, p, uap->signum); 1760 if (error == 0 && uap->signum) 1761 pksignal(p, uap->signum, &ksi); 1762 PROC_UNLOCK(p); 1763 return (error); 1764 } 1765 switch (uap->pid) { 1766 case -1: /* broadcast signal */ 1767 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1768 case 0: /* signal own process group */ 1769 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1770 default: /* negative explicit process group */ 1771 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1772 } 1773 /* NOTREACHED */ 1774 } 1775 1776 int 1777 sys_pdkill(td, uap) 1778 struct thread *td; 1779 struct pdkill_args *uap; 1780 { 1781 struct proc *p; 1782 cap_rights_t rights; 1783 int error; 1784 1785 AUDIT_ARG_SIGNUM(uap->signum); 1786 AUDIT_ARG_FD(uap->fd); 1787 if ((u_int)uap->signum > _SIG_MAXSIG) 1788 return (EINVAL); 1789 1790 error = procdesc_find(td, uap->fd, 1791 cap_rights_init(&rights, CAP_PDKILL), &p); 1792 if (error) 1793 return (error); 1794 AUDIT_ARG_PROCESS(p); 1795 error = p_cansignal(td, p, uap->signum); 1796 if (error == 0 && uap->signum) 1797 kern_psignal(p, uap->signum); 1798 PROC_UNLOCK(p); 1799 return (error); 1800 } 1801 1802 #if defined(COMPAT_43) 1803 #ifndef _SYS_SYSPROTO_H_ 1804 struct okillpg_args { 1805 int pgid; 1806 int signum; 1807 }; 1808 #endif 1809 /* ARGSUSED */ 1810 int 1811 okillpg(struct thread *td, struct okillpg_args *uap) 1812 { 1813 ksiginfo_t ksi; 1814 1815 AUDIT_ARG_SIGNUM(uap->signum); 1816 AUDIT_ARG_PID(uap->pgid); 1817 if ((u_int)uap->signum > _SIG_MAXSIG) 1818 return (EINVAL); 1819 1820 ksiginfo_init(&ksi); 1821 ksi.ksi_signo = uap->signum; 1822 ksi.ksi_code = SI_USER; 1823 ksi.ksi_pid = td->td_proc->p_pid; 1824 ksi.ksi_uid = td->td_ucred->cr_ruid; 1825 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1826 } 1827 #endif /* COMPAT_43 */ 1828 1829 #ifndef _SYS_SYSPROTO_H_ 1830 struct sigqueue_args { 1831 pid_t pid; 1832 int signum; 1833 /* union sigval */ void *value; 1834 }; 1835 #endif 1836 int 1837 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1838 { 1839 ksiginfo_t ksi; 1840 struct proc *p; 1841 int error; 1842 1843 if ((u_int)uap->signum > _SIG_MAXSIG) 1844 return (EINVAL); 1845 1846 /* 1847 * Specification says sigqueue can only send signal to 1848 * single process. 1849 */ 1850 if (uap->pid <= 0) 1851 return (EINVAL); 1852 1853 if ((p = pfind(uap->pid)) == NULL) { 1854 if ((p = zpfind(uap->pid)) == NULL) 1855 return (ESRCH); 1856 } 1857 error = p_cansignal(td, p, uap->signum); 1858 if (error == 0 && uap->signum != 0) { 1859 ksiginfo_init(&ksi); 1860 ksi.ksi_flags = KSI_SIGQ; 1861 ksi.ksi_signo = uap->signum; 1862 ksi.ksi_code = SI_QUEUE; 1863 ksi.ksi_pid = td->td_proc->p_pid; 1864 ksi.ksi_uid = td->td_ucred->cr_ruid; 1865 ksi.ksi_value.sival_ptr = uap->value; 1866 error = pksignal(p, ksi.ksi_signo, &ksi); 1867 } 1868 PROC_UNLOCK(p); 1869 return (error); 1870 } 1871 1872 /* 1873 * Send a signal to a process group. 1874 */ 1875 void 1876 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1877 { 1878 struct pgrp *pgrp; 1879 1880 if (pgid != 0) { 1881 sx_slock(&proctree_lock); 1882 pgrp = pgfind(pgid); 1883 sx_sunlock(&proctree_lock); 1884 if (pgrp != NULL) { 1885 pgsignal(pgrp, sig, 0, ksi); 1886 PGRP_UNLOCK(pgrp); 1887 } 1888 } 1889 } 1890 1891 /* 1892 * Send a signal to a process group. If checktty is 1, 1893 * limit to members which have a controlling terminal. 1894 */ 1895 void 1896 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1897 { 1898 struct proc *p; 1899 1900 if (pgrp) { 1901 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1902 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1903 PROC_LOCK(p); 1904 if (p->p_state == PRS_NORMAL && 1905 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1906 pksignal(p, sig, ksi); 1907 PROC_UNLOCK(p); 1908 } 1909 } 1910 } 1911 1912 1913 /* 1914 * Recalculate the signal mask and reset the signal disposition after 1915 * usermode frame for delivery is formed. Should be called after 1916 * mach-specific routine, because sysent->sv_sendsig() needs correct 1917 * ps_siginfo and signal mask. 1918 */ 1919 static void 1920 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1921 { 1922 sigset_t mask; 1923 1924 mtx_assert(&ps->ps_mtx, MA_OWNED); 1925 td->td_ru.ru_nsignals++; 1926 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1927 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1928 SIGADDSET(mask, sig); 1929 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1930 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1931 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1932 sigdflt(ps, sig); 1933 } 1934 1935 1936 /* 1937 * Send a signal caused by a trap to the current thread. If it will be 1938 * caught immediately, deliver it with correct code. Otherwise, post it 1939 * normally. 1940 */ 1941 void 1942 trapsignal(struct thread *td, ksiginfo_t *ksi) 1943 { 1944 struct sigacts *ps; 1945 struct proc *p; 1946 int sig; 1947 int code; 1948 1949 p = td->td_proc; 1950 sig = ksi->ksi_signo; 1951 code = ksi->ksi_code; 1952 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1953 1954 PROC_LOCK(p); 1955 ps = p->p_sigacts; 1956 mtx_lock(&ps->ps_mtx); 1957 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1958 !SIGISMEMBER(td->td_sigmask, sig)) { 1959 #ifdef KTRACE 1960 if (KTRPOINT(curthread, KTR_PSIG)) 1961 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1962 &td->td_sigmask, code); 1963 #endif 1964 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1965 ksi, &td->td_sigmask); 1966 postsig_done(sig, td, ps); 1967 mtx_unlock(&ps->ps_mtx); 1968 } else { 1969 /* 1970 * Avoid a possible infinite loop if the thread 1971 * masking the signal or process is ignoring the 1972 * signal. 1973 */ 1974 if (kern_forcesigexit && 1975 (SIGISMEMBER(td->td_sigmask, sig) || 1976 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1977 SIGDELSET(td->td_sigmask, sig); 1978 SIGDELSET(ps->ps_sigcatch, sig); 1979 SIGDELSET(ps->ps_sigignore, sig); 1980 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1981 } 1982 mtx_unlock(&ps->ps_mtx); 1983 p->p_code = code; /* XXX for core dump/debugger */ 1984 p->p_sig = sig; /* XXX to verify code */ 1985 tdsendsignal(p, td, sig, ksi); 1986 } 1987 PROC_UNLOCK(p); 1988 } 1989 1990 static struct thread * 1991 sigtd(struct proc *p, int sig, int prop) 1992 { 1993 struct thread *td, *signal_td; 1994 1995 PROC_LOCK_ASSERT(p, MA_OWNED); 1996 1997 /* 1998 * Check if current thread can handle the signal without 1999 * switching context to another thread. 2000 */ 2001 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2002 return (curthread); 2003 signal_td = NULL; 2004 FOREACH_THREAD_IN_PROC(p, td) { 2005 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2006 signal_td = td; 2007 break; 2008 } 2009 } 2010 if (signal_td == NULL) 2011 signal_td = FIRST_THREAD_IN_PROC(p); 2012 return (signal_td); 2013 } 2014 2015 /* 2016 * Send the signal to the process. If the signal has an action, the action 2017 * is usually performed by the target process rather than the caller; we add 2018 * the signal to the set of pending signals for the process. 2019 * 2020 * Exceptions: 2021 * o When a stop signal is sent to a sleeping process that takes the 2022 * default action, the process is stopped without awakening it. 2023 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2024 * regardless of the signal action (eg, blocked or ignored). 2025 * 2026 * Other ignored signals are discarded immediately. 2027 * 2028 * NB: This function may be entered from the debugger via the "kill" DDB 2029 * command. There is little that can be done to mitigate the possibly messy 2030 * side effects of this unwise possibility. 2031 */ 2032 void 2033 kern_psignal(struct proc *p, int sig) 2034 { 2035 ksiginfo_t ksi; 2036 2037 ksiginfo_init(&ksi); 2038 ksi.ksi_signo = sig; 2039 ksi.ksi_code = SI_KERNEL; 2040 (void) tdsendsignal(p, NULL, sig, &ksi); 2041 } 2042 2043 int 2044 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2045 { 2046 2047 return (tdsendsignal(p, NULL, sig, ksi)); 2048 } 2049 2050 /* Utility function for finding a thread to send signal event to. */ 2051 int 2052 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2053 { 2054 struct thread *td; 2055 2056 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2057 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2058 if (td == NULL) 2059 return (ESRCH); 2060 *ttd = td; 2061 } else { 2062 *ttd = NULL; 2063 PROC_LOCK(p); 2064 } 2065 return (0); 2066 } 2067 2068 void 2069 tdsignal(struct thread *td, int sig) 2070 { 2071 ksiginfo_t ksi; 2072 2073 ksiginfo_init(&ksi); 2074 ksi.ksi_signo = sig; 2075 ksi.ksi_code = SI_KERNEL; 2076 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2077 } 2078 2079 void 2080 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2081 { 2082 2083 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2084 } 2085 2086 int 2087 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2088 { 2089 sig_t action; 2090 sigqueue_t *sigqueue; 2091 int prop; 2092 struct sigacts *ps; 2093 int intrval; 2094 int ret = 0; 2095 int wakeup_swapper; 2096 2097 MPASS(td == NULL || p == td->td_proc); 2098 PROC_LOCK_ASSERT(p, MA_OWNED); 2099 2100 if (!_SIG_VALID(sig)) 2101 panic("%s(): invalid signal %d", __func__, sig); 2102 2103 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2104 2105 /* 2106 * IEEE Std 1003.1-2001: return success when killing a zombie. 2107 */ 2108 if (p->p_state == PRS_ZOMBIE) { 2109 if (ksi && (ksi->ksi_flags & KSI_INS)) 2110 ksiginfo_tryfree(ksi); 2111 return (ret); 2112 } 2113 2114 ps = p->p_sigacts; 2115 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2116 prop = sigprop(sig); 2117 2118 if (td == NULL) { 2119 td = sigtd(p, sig, prop); 2120 sigqueue = &p->p_sigqueue; 2121 } else 2122 sigqueue = &td->td_sigqueue; 2123 2124 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2125 2126 /* 2127 * If the signal is being ignored, 2128 * then we forget about it immediately. 2129 * (Note: we don't set SIGCONT in ps_sigignore, 2130 * and if it is set to SIG_IGN, 2131 * action will be SIG_DFL here.) 2132 */ 2133 mtx_lock(&ps->ps_mtx); 2134 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2135 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2136 2137 mtx_unlock(&ps->ps_mtx); 2138 if (ksi && (ksi->ksi_flags & KSI_INS)) 2139 ksiginfo_tryfree(ksi); 2140 return (ret); 2141 } 2142 if (SIGISMEMBER(td->td_sigmask, sig)) 2143 action = SIG_HOLD; 2144 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2145 action = SIG_CATCH; 2146 else 2147 action = SIG_DFL; 2148 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2149 intrval = EINTR; 2150 else 2151 intrval = ERESTART; 2152 mtx_unlock(&ps->ps_mtx); 2153 2154 if (prop & SA_CONT) 2155 sigqueue_delete_stopmask_proc(p); 2156 else if (prop & SA_STOP) { 2157 /* 2158 * If sending a tty stop signal to a member of an orphaned 2159 * process group, discard the signal here if the action 2160 * is default; don't stop the process below if sleeping, 2161 * and don't clear any pending SIGCONT. 2162 */ 2163 if ((prop & SA_TTYSTOP) && 2164 (p->p_pgrp->pg_jobc == 0) && 2165 (action == SIG_DFL)) { 2166 if (ksi && (ksi->ksi_flags & KSI_INS)) 2167 ksiginfo_tryfree(ksi); 2168 return (ret); 2169 } 2170 sigqueue_delete_proc(p, SIGCONT); 2171 if (p->p_flag & P_CONTINUED) { 2172 p->p_flag &= ~P_CONTINUED; 2173 PROC_LOCK(p->p_pptr); 2174 sigqueue_take(p->p_ksi); 2175 PROC_UNLOCK(p->p_pptr); 2176 } 2177 } 2178 2179 ret = sigqueue_add(sigqueue, sig, ksi); 2180 if (ret != 0) 2181 return (ret); 2182 signotify(td); 2183 /* 2184 * Defer further processing for signals which are held, 2185 * except that stopped processes must be continued by SIGCONT. 2186 */ 2187 if (action == SIG_HOLD && 2188 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2189 return (ret); 2190 /* 2191 * SIGKILL: Remove procfs STOPEVENTs. 2192 */ 2193 if (sig == SIGKILL) { 2194 /* from procfs_ioctl.c: PIOCBIC */ 2195 p->p_stops = 0; 2196 /* from procfs_ioctl.c: PIOCCONT */ 2197 p->p_step = 0; 2198 wakeup(&p->p_step); 2199 } 2200 /* 2201 * Some signals have a process-wide effect and a per-thread 2202 * component. Most processing occurs when the process next 2203 * tries to cross the user boundary, however there are some 2204 * times when processing needs to be done immediately, such as 2205 * waking up threads so that they can cross the user boundary. 2206 * We try to do the per-process part here. 2207 */ 2208 if (P_SHOULDSTOP(p)) { 2209 KASSERT(!(p->p_flag & P_WEXIT), 2210 ("signal to stopped but exiting process")); 2211 if (sig == SIGKILL) { 2212 /* 2213 * If traced process is already stopped, 2214 * then no further action is necessary. 2215 */ 2216 if (p->p_flag & P_TRACED) 2217 goto out; 2218 /* 2219 * SIGKILL sets process running. 2220 * It will die elsewhere. 2221 * All threads must be restarted. 2222 */ 2223 p->p_flag &= ~P_STOPPED_SIG; 2224 goto runfast; 2225 } 2226 2227 if (prop & SA_CONT) { 2228 /* 2229 * If traced process is already stopped, 2230 * then no further action is necessary. 2231 */ 2232 if (p->p_flag & P_TRACED) 2233 goto out; 2234 /* 2235 * If SIGCONT is default (or ignored), we continue the 2236 * process but don't leave the signal in sigqueue as 2237 * it has no further action. If SIGCONT is held, we 2238 * continue the process and leave the signal in 2239 * sigqueue. If the process catches SIGCONT, let it 2240 * handle the signal itself. If it isn't waiting on 2241 * an event, it goes back to run state. 2242 * Otherwise, process goes back to sleep state. 2243 */ 2244 p->p_flag &= ~P_STOPPED_SIG; 2245 PROC_SLOCK(p); 2246 if (p->p_numthreads == p->p_suspcount) { 2247 PROC_SUNLOCK(p); 2248 p->p_flag |= P_CONTINUED; 2249 p->p_xsig = SIGCONT; 2250 PROC_LOCK(p->p_pptr); 2251 childproc_continued(p); 2252 PROC_UNLOCK(p->p_pptr); 2253 PROC_SLOCK(p); 2254 } 2255 if (action == SIG_DFL) { 2256 thread_unsuspend(p); 2257 PROC_SUNLOCK(p); 2258 sigqueue_delete(sigqueue, sig); 2259 goto out; 2260 } 2261 if (action == SIG_CATCH) { 2262 /* 2263 * The process wants to catch it so it needs 2264 * to run at least one thread, but which one? 2265 */ 2266 PROC_SUNLOCK(p); 2267 goto runfast; 2268 } 2269 /* 2270 * The signal is not ignored or caught. 2271 */ 2272 thread_unsuspend(p); 2273 PROC_SUNLOCK(p); 2274 goto out; 2275 } 2276 2277 if (prop & SA_STOP) { 2278 /* 2279 * If traced process is already stopped, 2280 * then no further action is necessary. 2281 */ 2282 if (p->p_flag & P_TRACED) 2283 goto out; 2284 /* 2285 * Already stopped, don't need to stop again 2286 * (If we did the shell could get confused). 2287 * Just make sure the signal STOP bit set. 2288 */ 2289 p->p_flag |= P_STOPPED_SIG; 2290 sigqueue_delete(sigqueue, sig); 2291 goto out; 2292 } 2293 2294 /* 2295 * All other kinds of signals: 2296 * If a thread is sleeping interruptibly, simulate a 2297 * wakeup so that when it is continued it will be made 2298 * runnable and can look at the signal. However, don't make 2299 * the PROCESS runnable, leave it stopped. 2300 * It may run a bit until it hits a thread_suspend_check(). 2301 */ 2302 wakeup_swapper = 0; 2303 PROC_SLOCK(p); 2304 thread_lock(td); 2305 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2306 wakeup_swapper = sleepq_abort(td, intrval); 2307 thread_unlock(td); 2308 PROC_SUNLOCK(p); 2309 if (wakeup_swapper) 2310 kick_proc0(); 2311 goto out; 2312 /* 2313 * Mutexes are short lived. Threads waiting on them will 2314 * hit thread_suspend_check() soon. 2315 */ 2316 } else if (p->p_state == PRS_NORMAL) { 2317 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2318 tdsigwakeup(td, sig, action, intrval); 2319 goto out; 2320 } 2321 2322 MPASS(action == SIG_DFL); 2323 2324 if (prop & SA_STOP) { 2325 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2326 goto out; 2327 p->p_flag |= P_STOPPED_SIG; 2328 p->p_xsig = sig; 2329 PROC_SLOCK(p); 2330 sig_suspend_threads(td, p, 1); 2331 if (p->p_numthreads == p->p_suspcount) { 2332 /* 2333 * only thread sending signal to another 2334 * process can reach here, if thread is sending 2335 * signal to its process, because thread does 2336 * not suspend itself here, p_numthreads 2337 * should never be equal to p_suspcount. 2338 */ 2339 thread_stopped(p); 2340 PROC_SUNLOCK(p); 2341 sigqueue_delete_proc(p, p->p_xsig); 2342 } else 2343 PROC_SUNLOCK(p); 2344 goto out; 2345 } 2346 } else { 2347 /* Not in "NORMAL" state. discard the signal. */ 2348 sigqueue_delete(sigqueue, sig); 2349 goto out; 2350 } 2351 2352 /* 2353 * The process is not stopped so we need to apply the signal to all the 2354 * running threads. 2355 */ 2356 runfast: 2357 tdsigwakeup(td, sig, action, intrval); 2358 PROC_SLOCK(p); 2359 thread_unsuspend(p); 2360 PROC_SUNLOCK(p); 2361 out: 2362 /* If we jump here, proc slock should not be owned. */ 2363 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2364 return (ret); 2365 } 2366 2367 /* 2368 * The force of a signal has been directed against a single 2369 * thread. We need to see what we can do about knocking it 2370 * out of any sleep it may be in etc. 2371 */ 2372 static void 2373 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2374 { 2375 struct proc *p = td->td_proc; 2376 register int prop; 2377 int wakeup_swapper; 2378 2379 wakeup_swapper = 0; 2380 PROC_LOCK_ASSERT(p, MA_OWNED); 2381 prop = sigprop(sig); 2382 2383 PROC_SLOCK(p); 2384 thread_lock(td); 2385 /* 2386 * Bring the priority of a thread up if we want it to get 2387 * killed in this lifetime. Be careful to avoid bumping the 2388 * priority of the idle thread, since we still allow to signal 2389 * kernel processes. 2390 */ 2391 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2392 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2393 sched_prio(td, PUSER); 2394 if (TD_ON_SLEEPQ(td)) { 2395 /* 2396 * If thread is sleeping uninterruptibly 2397 * we can't interrupt the sleep... the signal will 2398 * be noticed when the process returns through 2399 * trap() or syscall(). 2400 */ 2401 if ((td->td_flags & TDF_SINTR) == 0) 2402 goto out; 2403 /* 2404 * If SIGCONT is default (or ignored) and process is 2405 * asleep, we are finished; the process should not 2406 * be awakened. 2407 */ 2408 if ((prop & SA_CONT) && action == SIG_DFL) { 2409 thread_unlock(td); 2410 PROC_SUNLOCK(p); 2411 sigqueue_delete(&p->p_sigqueue, sig); 2412 /* 2413 * It may be on either list in this state. 2414 * Remove from both for now. 2415 */ 2416 sigqueue_delete(&td->td_sigqueue, sig); 2417 return; 2418 } 2419 2420 /* 2421 * Don't awaken a sleeping thread for SIGSTOP if the 2422 * STOP signal is deferred. 2423 */ 2424 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2425 goto out; 2426 2427 /* 2428 * Give low priority threads a better chance to run. 2429 */ 2430 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2431 sched_prio(td, PUSER); 2432 2433 wakeup_swapper = sleepq_abort(td, intrval); 2434 } else { 2435 /* 2436 * Other states do nothing with the signal immediately, 2437 * other than kicking ourselves if we are running. 2438 * It will either never be noticed, or noticed very soon. 2439 */ 2440 #ifdef SMP 2441 if (TD_IS_RUNNING(td) && td != curthread) 2442 forward_signal(td); 2443 #endif 2444 } 2445 out: 2446 PROC_SUNLOCK(p); 2447 thread_unlock(td); 2448 if (wakeup_swapper) 2449 kick_proc0(); 2450 } 2451 2452 static void 2453 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2454 { 2455 struct thread *td2; 2456 2457 PROC_LOCK_ASSERT(p, MA_OWNED); 2458 PROC_SLOCK_ASSERT(p, MA_OWNED); 2459 2460 FOREACH_THREAD_IN_PROC(p, td2) { 2461 thread_lock(td2); 2462 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2463 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2464 (td2->td_flags & TDF_SINTR)) { 2465 if (td2->td_flags & TDF_SBDRY) { 2466 /* 2467 * Once a thread is asleep with 2468 * TDF_SBDRY set, it should never 2469 * become suspended due to this check. 2470 */ 2471 KASSERT(!TD_IS_SUSPENDED(td2), 2472 ("thread with deferred stops suspended")); 2473 } else if (!TD_IS_SUSPENDED(td2)) { 2474 thread_suspend_one(td2); 2475 } 2476 } else if (!TD_IS_SUSPENDED(td2)) { 2477 if (sending || td != td2) 2478 td2->td_flags |= TDF_ASTPENDING; 2479 #ifdef SMP 2480 if (TD_IS_RUNNING(td2) && td2 != td) 2481 forward_signal(td2); 2482 #endif 2483 } 2484 thread_unlock(td2); 2485 } 2486 } 2487 2488 int 2489 ptracestop(struct thread *td, int sig) 2490 { 2491 struct proc *p = td->td_proc; 2492 2493 PROC_LOCK_ASSERT(p, MA_OWNED); 2494 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2495 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2496 &p->p_mtx.lock_object, "Stopping for traced signal"); 2497 2498 td->td_dbgflags |= TDB_XSIG; 2499 td->td_xsig = sig; 2500 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2501 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2502 PROC_SLOCK(p); 2503 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2504 if (p->p_flag & P_SINGLE_EXIT && 2505 !(td->td_dbgflags & TDB_EXIT)) { 2506 /* 2507 * Ignore ptrace stops except for thread exit 2508 * events when the process exits. 2509 */ 2510 td->td_dbgflags &= ~TDB_XSIG; 2511 PROC_SUNLOCK(p); 2512 return (sig); 2513 } 2514 /* 2515 * Just make wait() to work, the last stopped thread 2516 * will win. 2517 */ 2518 p->p_xsig = sig; 2519 p->p_xthread = td; 2520 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2521 sig_suspend_threads(td, p, 0); 2522 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2523 td->td_dbgflags &= ~TDB_STOPATFORK; 2524 cv_broadcast(&p->p_dbgwait); 2525 } 2526 stopme: 2527 thread_suspend_switch(td, p); 2528 if (p->p_xthread == td) 2529 p->p_xthread = NULL; 2530 if (!(p->p_flag & P_TRACED)) 2531 break; 2532 if (td->td_dbgflags & TDB_SUSPEND) { 2533 if (p->p_flag & P_SINGLE_EXIT) 2534 break; 2535 goto stopme; 2536 } 2537 } 2538 PROC_SUNLOCK(p); 2539 return (td->td_xsig); 2540 } 2541 2542 static void 2543 reschedule_signals(struct proc *p, sigset_t block, int flags) 2544 { 2545 struct sigacts *ps; 2546 struct thread *td; 2547 int sig; 2548 2549 PROC_LOCK_ASSERT(p, MA_OWNED); 2550 ps = p->p_sigacts; 2551 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2552 MA_OWNED : MA_NOTOWNED); 2553 if (SIGISEMPTY(p->p_siglist)) 2554 return; 2555 SIGSETAND(block, p->p_siglist); 2556 while ((sig = sig_ffs(&block)) != 0) { 2557 SIGDELSET(block, sig); 2558 td = sigtd(p, sig, 0); 2559 signotify(td); 2560 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2561 mtx_lock(&ps->ps_mtx); 2562 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2563 tdsigwakeup(td, sig, SIG_CATCH, 2564 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2565 ERESTART)); 2566 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2567 mtx_unlock(&ps->ps_mtx); 2568 } 2569 } 2570 2571 void 2572 tdsigcleanup(struct thread *td) 2573 { 2574 struct proc *p; 2575 sigset_t unblocked; 2576 2577 p = td->td_proc; 2578 PROC_LOCK_ASSERT(p, MA_OWNED); 2579 2580 sigqueue_flush(&td->td_sigqueue); 2581 if (p->p_numthreads == 1) 2582 return; 2583 2584 /* 2585 * Since we cannot handle signals, notify signal post code 2586 * about this by filling the sigmask. 2587 * 2588 * Also, if needed, wake up thread(s) that do not block the 2589 * same signals as the exiting thread, since the thread might 2590 * have been selected for delivery and woken up. 2591 */ 2592 SIGFILLSET(unblocked); 2593 SIGSETNAND(unblocked, td->td_sigmask); 2594 SIGFILLSET(td->td_sigmask); 2595 reschedule_signals(p, unblocked, 0); 2596 2597 } 2598 2599 /* 2600 * Defer the delivery of SIGSTOP for the current thread. Returns true 2601 * if stops were deferred and false if they were already deferred. 2602 */ 2603 int 2604 sigdeferstop(void) 2605 { 2606 struct thread *td; 2607 2608 td = curthread; 2609 if (td->td_flags & TDF_SBDRY) 2610 return (0); 2611 thread_lock(td); 2612 td->td_flags |= TDF_SBDRY; 2613 thread_unlock(td); 2614 return (1); 2615 } 2616 2617 /* 2618 * Permit the delivery of SIGSTOP for the current thread. This does 2619 * not immediately suspend if a stop was posted. Instead, the thread 2620 * will suspend either via ast() or a subsequent interruptible sleep. 2621 */ 2622 int 2623 sigallowstop(void) 2624 { 2625 struct thread *td; 2626 int prev; 2627 2628 td = curthread; 2629 thread_lock(td); 2630 prev = (td->td_flags & TDF_SBDRY) != 0; 2631 td->td_flags &= ~TDF_SBDRY; 2632 thread_unlock(td); 2633 return (prev); 2634 } 2635 2636 /* 2637 * If the current process has received a signal (should be caught or cause 2638 * termination, should interrupt current syscall), return the signal number. 2639 * Stop signals with default action are processed immediately, then cleared; 2640 * they aren't returned. This is checked after each entry to the system for 2641 * a syscall or trap (though this can usually be done without calling issignal 2642 * by checking the pending signal masks in cursig.) The normal call 2643 * sequence is 2644 * 2645 * while (sig = cursig(curthread)) 2646 * postsig(sig); 2647 */ 2648 static int 2649 issignal(struct thread *td) 2650 { 2651 struct proc *p; 2652 struct sigacts *ps; 2653 struct sigqueue *queue; 2654 sigset_t sigpending; 2655 int sig, prop, newsig; 2656 2657 p = td->td_proc; 2658 ps = p->p_sigacts; 2659 mtx_assert(&ps->ps_mtx, MA_OWNED); 2660 PROC_LOCK_ASSERT(p, MA_OWNED); 2661 for (;;) { 2662 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2663 2664 sigpending = td->td_sigqueue.sq_signals; 2665 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2666 SIGSETNAND(sigpending, td->td_sigmask); 2667 2668 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2669 SIG_STOPSIGMASK(sigpending); 2670 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2671 return (0); 2672 sig = sig_ffs(&sigpending); 2673 2674 if (p->p_stops & S_SIG) { 2675 mtx_unlock(&ps->ps_mtx); 2676 stopevent(p, S_SIG, sig); 2677 mtx_lock(&ps->ps_mtx); 2678 } 2679 2680 /* 2681 * We should see pending but ignored signals 2682 * only if P_TRACED was on when they were posted. 2683 */ 2684 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2685 sigqueue_delete(&td->td_sigqueue, sig); 2686 sigqueue_delete(&p->p_sigqueue, sig); 2687 continue; 2688 } 2689 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2690 /* 2691 * If traced, always stop. 2692 * Remove old signal from queue before the stop. 2693 * XXX shrug off debugger, it causes siginfo to 2694 * be thrown away. 2695 */ 2696 queue = &td->td_sigqueue; 2697 td->td_dbgksi.ksi_signo = 0; 2698 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2699 queue = &p->p_sigqueue; 2700 sigqueue_get(queue, sig, &td->td_dbgksi); 2701 } 2702 2703 mtx_unlock(&ps->ps_mtx); 2704 newsig = ptracestop(td, sig); 2705 mtx_lock(&ps->ps_mtx); 2706 2707 if (sig != newsig) { 2708 2709 /* 2710 * If parent wants us to take the signal, 2711 * then it will leave it in p->p_xsig; 2712 * otherwise we just look for signals again. 2713 */ 2714 if (newsig == 0) 2715 continue; 2716 sig = newsig; 2717 2718 /* 2719 * Put the new signal into td_sigqueue. If the 2720 * signal is being masked, look for other 2721 * signals. 2722 */ 2723 sigqueue_add(queue, sig, NULL); 2724 if (SIGISMEMBER(td->td_sigmask, sig)) 2725 continue; 2726 signotify(td); 2727 } else { 2728 if (td->td_dbgksi.ksi_signo != 0) { 2729 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2730 if (sigqueue_add(&td->td_sigqueue, sig, 2731 &td->td_dbgksi) != 0) 2732 td->td_dbgksi.ksi_signo = 0; 2733 } 2734 if (td->td_dbgksi.ksi_signo == 0) 2735 sigqueue_add(&td->td_sigqueue, sig, 2736 NULL); 2737 } 2738 2739 /* 2740 * If the traced bit got turned off, go back up 2741 * to the top to rescan signals. This ensures 2742 * that p_sig* and p_sigact are consistent. 2743 */ 2744 if ((p->p_flag & P_TRACED) == 0) 2745 continue; 2746 } 2747 2748 prop = sigprop(sig); 2749 2750 /* 2751 * Decide whether the signal should be returned. 2752 * Return the signal's number, or fall through 2753 * to clear it from the pending mask. 2754 */ 2755 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2756 2757 case (intptr_t)SIG_DFL: 2758 /* 2759 * Don't take default actions on system processes. 2760 */ 2761 if (p->p_pid <= 1) { 2762 #ifdef DIAGNOSTIC 2763 /* 2764 * Are you sure you want to ignore SIGSEGV 2765 * in init? XXX 2766 */ 2767 printf("Process (pid %lu) got signal %d\n", 2768 (u_long)p->p_pid, sig); 2769 #endif 2770 break; /* == ignore */ 2771 } 2772 /* 2773 * If there is a pending stop signal to process 2774 * with default action, stop here, 2775 * then clear the signal. However, 2776 * if process is member of an orphaned 2777 * process group, ignore tty stop signals. 2778 */ 2779 if (prop & SA_STOP) { 2780 if (p->p_flag & (P_TRACED|P_WEXIT) || 2781 (p->p_pgrp->pg_jobc == 0 && 2782 prop & SA_TTYSTOP)) 2783 break; /* == ignore */ 2784 mtx_unlock(&ps->ps_mtx); 2785 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2786 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2787 p->p_flag |= P_STOPPED_SIG; 2788 p->p_xsig = sig; 2789 PROC_SLOCK(p); 2790 sig_suspend_threads(td, p, 0); 2791 thread_suspend_switch(td, p); 2792 PROC_SUNLOCK(p); 2793 mtx_lock(&ps->ps_mtx); 2794 break; 2795 } else if (prop & SA_IGNORE) { 2796 /* 2797 * Except for SIGCONT, shouldn't get here. 2798 * Default action is to ignore; drop it. 2799 */ 2800 break; /* == ignore */ 2801 } else 2802 return (sig); 2803 /*NOTREACHED*/ 2804 2805 case (intptr_t)SIG_IGN: 2806 /* 2807 * Masking above should prevent us ever trying 2808 * to take action on an ignored signal other 2809 * than SIGCONT, unless process is traced. 2810 */ 2811 if ((prop & SA_CONT) == 0 && 2812 (p->p_flag & P_TRACED) == 0) 2813 printf("issignal\n"); 2814 break; /* == ignore */ 2815 2816 default: 2817 /* 2818 * This signal has an action, let 2819 * postsig() process it. 2820 */ 2821 return (sig); 2822 } 2823 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2824 sigqueue_delete(&p->p_sigqueue, sig); 2825 } 2826 /* NOTREACHED */ 2827 } 2828 2829 void 2830 thread_stopped(struct proc *p) 2831 { 2832 int n; 2833 2834 PROC_LOCK_ASSERT(p, MA_OWNED); 2835 PROC_SLOCK_ASSERT(p, MA_OWNED); 2836 n = p->p_suspcount; 2837 if (p == curproc) 2838 n++; 2839 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2840 PROC_SUNLOCK(p); 2841 p->p_flag &= ~P_WAITED; 2842 PROC_LOCK(p->p_pptr); 2843 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2844 CLD_TRAPPED : CLD_STOPPED); 2845 PROC_UNLOCK(p->p_pptr); 2846 PROC_SLOCK(p); 2847 } 2848 } 2849 2850 /* 2851 * Take the action for the specified signal 2852 * from the current set of pending signals. 2853 */ 2854 int 2855 postsig(sig) 2856 register int sig; 2857 { 2858 struct thread *td = curthread; 2859 register struct proc *p = td->td_proc; 2860 struct sigacts *ps; 2861 sig_t action; 2862 ksiginfo_t ksi; 2863 sigset_t returnmask; 2864 2865 KASSERT(sig != 0, ("postsig")); 2866 2867 PROC_LOCK_ASSERT(p, MA_OWNED); 2868 ps = p->p_sigacts; 2869 mtx_assert(&ps->ps_mtx, MA_OWNED); 2870 ksiginfo_init(&ksi); 2871 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2872 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2873 return (0); 2874 ksi.ksi_signo = sig; 2875 if (ksi.ksi_code == SI_TIMER) 2876 itimer_accept(p, ksi.ksi_timerid, &ksi); 2877 action = ps->ps_sigact[_SIG_IDX(sig)]; 2878 #ifdef KTRACE 2879 if (KTRPOINT(td, KTR_PSIG)) 2880 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2881 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2882 #endif 2883 if (p->p_stops & S_SIG) { 2884 mtx_unlock(&ps->ps_mtx); 2885 stopevent(p, S_SIG, sig); 2886 mtx_lock(&ps->ps_mtx); 2887 } 2888 2889 if (action == SIG_DFL) { 2890 /* 2891 * Default action, where the default is to kill 2892 * the process. (Other cases were ignored above.) 2893 */ 2894 mtx_unlock(&ps->ps_mtx); 2895 sigexit(td, sig); 2896 /* NOTREACHED */ 2897 } else { 2898 /* 2899 * If we get here, the signal must be caught. 2900 */ 2901 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2902 ("postsig action")); 2903 /* 2904 * Set the new mask value and also defer further 2905 * occurrences of this signal. 2906 * 2907 * Special case: user has done a sigsuspend. Here the 2908 * current mask is not of interest, but rather the 2909 * mask from before the sigsuspend is what we want 2910 * restored after the signal processing is completed. 2911 */ 2912 if (td->td_pflags & TDP_OLDMASK) { 2913 returnmask = td->td_oldsigmask; 2914 td->td_pflags &= ~TDP_OLDMASK; 2915 } else 2916 returnmask = td->td_sigmask; 2917 2918 if (p->p_sig == sig) { 2919 p->p_code = 0; 2920 p->p_sig = 0; 2921 } 2922 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2923 postsig_done(sig, td, ps); 2924 } 2925 return (1); 2926 } 2927 2928 /* 2929 * Kill the current process for stated reason. 2930 */ 2931 void 2932 killproc(p, why) 2933 struct proc *p; 2934 char *why; 2935 { 2936 2937 PROC_LOCK_ASSERT(p, MA_OWNED); 2938 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2939 p->p_comm); 2940 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2941 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2942 p->p_flag |= P_WKILLED; 2943 kern_psignal(p, SIGKILL); 2944 } 2945 2946 /* 2947 * Force the current process to exit with the specified signal, dumping core 2948 * if appropriate. We bypass the normal tests for masked and caught signals, 2949 * allowing unrecoverable failures to terminate the process without changing 2950 * signal state. Mark the accounting record with the signal termination. 2951 * If dumping core, save the signal number for the debugger. Calls exit and 2952 * does not return. 2953 */ 2954 void 2955 sigexit(td, sig) 2956 struct thread *td; 2957 int sig; 2958 { 2959 struct proc *p = td->td_proc; 2960 2961 PROC_LOCK_ASSERT(p, MA_OWNED); 2962 p->p_acflag |= AXSIG; 2963 /* 2964 * We must be single-threading to generate a core dump. This 2965 * ensures that the registers in the core file are up-to-date. 2966 * Also, the ELF dump handler assumes that the thread list doesn't 2967 * change out from under it. 2968 * 2969 * XXX If another thread attempts to single-thread before us 2970 * (e.g. via fork()), we won't get a dump at all. 2971 */ 2972 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 2973 p->p_sig = sig; 2974 /* 2975 * Log signals which would cause core dumps 2976 * (Log as LOG_INFO to appease those who don't want 2977 * these messages.) 2978 * XXX : Todo, as well as euid, write out ruid too 2979 * Note that coredump() drops proc lock. 2980 */ 2981 if (coredump(td) == 0) 2982 sig |= WCOREFLAG; 2983 if (kern_logsigexit) 2984 log(LOG_INFO, 2985 "pid %d (%s), uid %d: exited on signal %d%s\n", 2986 p->p_pid, p->p_comm, 2987 td->td_ucred ? td->td_ucred->cr_uid : -1, 2988 sig &~ WCOREFLAG, 2989 sig & WCOREFLAG ? " (core dumped)" : ""); 2990 } else 2991 PROC_UNLOCK(p); 2992 exit1(td, 0, sig); 2993 /* NOTREACHED */ 2994 } 2995 2996 /* 2997 * Send queued SIGCHLD to parent when child process's state 2998 * is changed. 2999 */ 3000 static void 3001 sigparent(struct proc *p, int reason, int status) 3002 { 3003 PROC_LOCK_ASSERT(p, MA_OWNED); 3004 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3005 3006 if (p->p_ksi != NULL) { 3007 p->p_ksi->ksi_signo = SIGCHLD; 3008 p->p_ksi->ksi_code = reason; 3009 p->p_ksi->ksi_status = status; 3010 p->p_ksi->ksi_pid = p->p_pid; 3011 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3012 if (KSI_ONQ(p->p_ksi)) 3013 return; 3014 } 3015 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3016 } 3017 3018 static void 3019 childproc_jobstate(struct proc *p, int reason, int sig) 3020 { 3021 struct sigacts *ps; 3022 3023 PROC_LOCK_ASSERT(p, MA_OWNED); 3024 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3025 3026 /* 3027 * Wake up parent sleeping in kern_wait(), also send 3028 * SIGCHLD to parent, but SIGCHLD does not guarantee 3029 * that parent will awake, because parent may masked 3030 * the signal. 3031 */ 3032 p->p_pptr->p_flag |= P_STATCHILD; 3033 wakeup(p->p_pptr); 3034 3035 ps = p->p_pptr->p_sigacts; 3036 mtx_lock(&ps->ps_mtx); 3037 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3038 mtx_unlock(&ps->ps_mtx); 3039 sigparent(p, reason, sig); 3040 } else 3041 mtx_unlock(&ps->ps_mtx); 3042 } 3043 3044 void 3045 childproc_stopped(struct proc *p, int reason) 3046 { 3047 3048 childproc_jobstate(p, reason, p->p_xsig); 3049 } 3050 3051 void 3052 childproc_continued(struct proc *p) 3053 { 3054 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3055 } 3056 3057 void 3058 childproc_exited(struct proc *p) 3059 { 3060 int reason, status; 3061 3062 if (WCOREDUMP(p->p_xsig)) { 3063 reason = CLD_DUMPED; 3064 status = WTERMSIG(p->p_xsig); 3065 } else if (WIFSIGNALED(p->p_xsig)) { 3066 reason = CLD_KILLED; 3067 status = WTERMSIG(p->p_xsig); 3068 } else { 3069 reason = CLD_EXITED; 3070 status = p->p_xexit; 3071 } 3072 /* 3073 * XXX avoid calling wakeup(p->p_pptr), the work is 3074 * done in exit1(). 3075 */ 3076 sigparent(p, reason, status); 3077 } 3078 3079 /* 3080 * We only have 1 character for the core count in the format 3081 * string, so the range will be 0-9 3082 */ 3083 #define MAX_NUM_CORES 10 3084 static int num_cores = 5; 3085 3086 static int 3087 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3088 { 3089 int error; 3090 int new_val; 3091 3092 new_val = num_cores; 3093 error = sysctl_handle_int(oidp, &new_val, 0, req); 3094 if (error != 0 || req->newptr == NULL) 3095 return (error); 3096 if (new_val > MAX_NUM_CORES) 3097 new_val = MAX_NUM_CORES; 3098 if (new_val < 0) 3099 new_val = 0; 3100 num_cores = new_val; 3101 return (0); 3102 } 3103 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3104 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3105 3106 #define GZ_SUFFIX ".gz" 3107 3108 #ifdef GZIO 3109 static int compress_user_cores = 1; 3110 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN, 3111 &compress_user_cores, 0, "Compression of user corefiles"); 3112 3113 int compress_user_cores_gzlevel = 6; 3114 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN, 3115 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level"); 3116 #else 3117 static int compress_user_cores = 0; 3118 #endif 3119 3120 /* 3121 * Protect the access to corefilename[] by allproc_lock. 3122 */ 3123 #define corefilename_lock allproc_lock 3124 3125 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3126 3127 static int 3128 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3129 { 3130 int error; 3131 3132 sx_xlock(&corefilename_lock); 3133 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3134 req); 3135 sx_xunlock(&corefilename_lock); 3136 3137 return (error); 3138 } 3139 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RWTUN | 3140 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3141 "Process corefile name format string"); 3142 3143 /* 3144 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3145 * Expand the name described in corefilename, using name, uid, and pid 3146 * and open/create core file. 3147 * corefilename is a printf-like string, with three format specifiers: 3148 * %N name of process ("name") 3149 * %P process id (pid) 3150 * %U user id (uid) 3151 * For example, "%N.core" is the default; they can be disabled completely 3152 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3153 * This is controlled by the sysctl variable kern.corefile (see above). 3154 */ 3155 static int 3156 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3157 int compress, struct vnode **vpp, char **namep) 3158 { 3159 struct nameidata nd; 3160 struct sbuf sb; 3161 const char *format; 3162 char *hostname, *name; 3163 int indexpos, i, error, cmode, flags, oflags; 3164 3165 hostname = NULL; 3166 format = corefilename; 3167 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3168 indexpos = -1; 3169 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3170 sx_slock(&corefilename_lock); 3171 for (i = 0; format[i] != '\0'; i++) { 3172 switch (format[i]) { 3173 case '%': /* Format character */ 3174 i++; 3175 switch (format[i]) { 3176 case '%': 3177 sbuf_putc(&sb, '%'); 3178 break; 3179 case 'H': /* hostname */ 3180 if (hostname == NULL) { 3181 hostname = malloc(MAXHOSTNAMELEN, 3182 M_TEMP, M_WAITOK); 3183 } 3184 getcredhostname(td->td_ucred, hostname, 3185 MAXHOSTNAMELEN); 3186 sbuf_printf(&sb, "%s", hostname); 3187 break; 3188 case 'I': /* autoincrementing index */ 3189 sbuf_printf(&sb, "0"); 3190 indexpos = sbuf_len(&sb) - 1; 3191 break; 3192 case 'N': /* process name */ 3193 sbuf_printf(&sb, "%s", comm); 3194 break; 3195 case 'P': /* process id */ 3196 sbuf_printf(&sb, "%u", pid); 3197 break; 3198 case 'U': /* user id */ 3199 sbuf_printf(&sb, "%u", uid); 3200 break; 3201 default: 3202 log(LOG_ERR, 3203 "Unknown format character %c in " 3204 "corename `%s'\n", format[i], format); 3205 break; 3206 } 3207 break; 3208 default: 3209 sbuf_putc(&sb, format[i]); 3210 break; 3211 } 3212 } 3213 sx_sunlock(&corefilename_lock); 3214 free(hostname, M_TEMP); 3215 if (compress) 3216 sbuf_printf(&sb, GZ_SUFFIX); 3217 if (sbuf_error(&sb) != 0) { 3218 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3219 "long\n", (long)pid, comm, (u_long)uid); 3220 sbuf_delete(&sb); 3221 free(name, M_TEMP); 3222 return (ENOMEM); 3223 } 3224 sbuf_finish(&sb); 3225 sbuf_delete(&sb); 3226 3227 cmode = S_IRUSR | S_IWUSR; 3228 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3229 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3230 3231 /* 3232 * If the core format has a %I in it, then we need to check 3233 * for existing corefiles before returning a name. 3234 * To do this we iterate over 0..num_cores to find a 3235 * non-existing core file name to use. 3236 */ 3237 if (indexpos != -1) { 3238 for (i = 0; i < num_cores; i++) { 3239 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3240 name[indexpos] = '0' + i; 3241 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3242 error = vn_open_cred(&nd, &flags, cmode, oflags, 3243 td->td_ucred, NULL); 3244 if (error) { 3245 if (error == EEXIST) 3246 continue; 3247 log(LOG_ERR, 3248 "pid %d (%s), uid (%u): Path `%s' failed " 3249 "on initial open test, error = %d\n", 3250 pid, comm, uid, name, error); 3251 } 3252 goto out; 3253 } 3254 } 3255 3256 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3257 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3258 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3259 out: 3260 if (error) { 3261 #ifdef AUDIT 3262 audit_proc_coredump(td, name, error); 3263 #endif 3264 free(name, M_TEMP); 3265 return (error); 3266 } 3267 NDFREE(&nd, NDF_ONLY_PNBUF); 3268 *vpp = nd.ni_vp; 3269 *namep = name; 3270 return (0); 3271 } 3272 3273 static int 3274 coredump_sanitise_path(const char *path) 3275 { 3276 size_t i; 3277 3278 /* 3279 * Only send a subset of ASCII to devd(8) because it 3280 * might pass these strings to sh -c. 3281 */ 3282 for (i = 0; path[i]; i++) 3283 if (!(isalpha(path[i]) || isdigit(path[i])) && 3284 path[i] != '/' && path[i] != '.' && 3285 path[i] != '-') 3286 return (0); 3287 3288 return (1); 3289 } 3290 3291 /* 3292 * Dump a process' core. The main routine does some 3293 * policy checking, and creates the name of the coredump; 3294 * then it passes on a vnode and a size limit to the process-specific 3295 * coredump routine if there is one; if there _is not_ one, it returns 3296 * ENOSYS; otherwise it returns the error from the process-specific routine. 3297 */ 3298 3299 static int 3300 coredump(struct thread *td) 3301 { 3302 struct proc *p = td->td_proc; 3303 struct ucred *cred = td->td_ucred; 3304 struct vnode *vp; 3305 struct flock lf; 3306 struct vattr vattr; 3307 int error, error1, locked; 3308 char *name; /* name of corefile */ 3309 void *rl_cookie; 3310 off_t limit; 3311 char *data = NULL; 3312 char *fullpath, *freepath = NULL; 3313 size_t len; 3314 static const char comm_name[] = "comm="; 3315 static const char core_name[] = "core="; 3316 3317 PROC_LOCK_ASSERT(p, MA_OWNED); 3318 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3319 _STOPEVENT(p, S_CORE, 0); 3320 3321 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3322 (p->p_flag2 & P2_NOTRACE) != 0) { 3323 PROC_UNLOCK(p); 3324 return (EFAULT); 3325 } 3326 3327 /* 3328 * Note that the bulk of limit checking is done after 3329 * the corefile is created. The exception is if the limit 3330 * for corefiles is 0, in which case we don't bother 3331 * creating the corefile at all. This layout means that 3332 * a corefile is truncated instead of not being created, 3333 * if it is larger than the limit. 3334 */ 3335 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3336 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3337 PROC_UNLOCK(p); 3338 return (EFBIG); 3339 } 3340 PROC_UNLOCK(p); 3341 3342 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3343 compress_user_cores, &vp, &name); 3344 if (error != 0) 3345 return (error); 3346 3347 /* 3348 * Don't dump to non-regular files or files with links. 3349 * Do not dump into system files. 3350 */ 3351 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3352 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3353 VOP_UNLOCK(vp, 0); 3354 error = EFAULT; 3355 goto out; 3356 } 3357 3358 VOP_UNLOCK(vp, 0); 3359 3360 /* Postpone other writers, including core dumps of other processes. */ 3361 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3362 3363 lf.l_whence = SEEK_SET; 3364 lf.l_start = 0; 3365 lf.l_len = 0; 3366 lf.l_type = F_WRLCK; 3367 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3368 3369 VATTR_NULL(&vattr); 3370 vattr.va_size = 0; 3371 if (set_core_nodump_flag) 3372 vattr.va_flags = UF_NODUMP; 3373 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3374 VOP_SETATTR(vp, &vattr, cred); 3375 VOP_UNLOCK(vp, 0); 3376 PROC_LOCK(p); 3377 p->p_acflag |= ACORE; 3378 PROC_UNLOCK(p); 3379 3380 if (p->p_sysent->sv_coredump != NULL) { 3381 error = p->p_sysent->sv_coredump(td, vp, limit, 3382 compress_user_cores ? IMGACT_CORE_COMPRESS : 0); 3383 } else { 3384 error = ENOSYS; 3385 } 3386 3387 if (locked) { 3388 lf.l_type = F_UNLCK; 3389 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3390 } 3391 vn_rangelock_unlock(vp, rl_cookie); 3392 3393 /* 3394 * Notify the userland helper that a process triggered a core dump. 3395 * This allows the helper to run an automated debugging session. 3396 */ 3397 if (error != 0 || coredump_devctl == 0) 3398 goto out; 3399 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3400 sizeof(' ') + sizeof(core_name) - 1; 3401 data = malloc(len, M_TEMP, M_WAITOK); 3402 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3403 goto out; 3404 if (!coredump_sanitise_path(fullpath)) 3405 goto out; 3406 snprintf(data, len, "%s%s ", comm_name, fullpath); 3407 free(freepath, M_TEMP); 3408 freepath = NULL; 3409 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3410 goto out; 3411 if (!coredump_sanitise_path(fullpath)) 3412 goto out; 3413 strlcat(data, core_name, len); 3414 strlcat(data, fullpath, len); 3415 devctl_notify("kernel", "signal", "coredump", data); 3416 out: 3417 error1 = vn_close(vp, FWRITE, cred, td); 3418 if (error == 0) 3419 error = error1; 3420 #ifdef AUDIT 3421 audit_proc_coredump(td, name, error); 3422 #endif 3423 free(freepath, M_TEMP); 3424 free(data, M_TEMP); 3425 free(name, M_TEMP); 3426 return (error); 3427 } 3428 3429 /* 3430 * Nonexistent system call-- signal process (may want to handle it). Flag 3431 * error in case process won't see signal immediately (blocked or ignored). 3432 */ 3433 #ifndef _SYS_SYSPROTO_H_ 3434 struct nosys_args { 3435 int dummy; 3436 }; 3437 #endif 3438 /* ARGSUSED */ 3439 int 3440 nosys(td, args) 3441 struct thread *td; 3442 struct nosys_args *args; 3443 { 3444 struct proc *p = td->td_proc; 3445 3446 PROC_LOCK(p); 3447 tdsignal(td, SIGSYS); 3448 PROC_UNLOCK(p); 3449 return (ENOSYS); 3450 } 3451 3452 /* 3453 * Send a SIGIO or SIGURG signal to a process or process group using stored 3454 * credentials rather than those of the current process. 3455 */ 3456 void 3457 pgsigio(sigiop, sig, checkctty) 3458 struct sigio **sigiop; 3459 int sig, checkctty; 3460 { 3461 ksiginfo_t ksi; 3462 struct sigio *sigio; 3463 3464 ksiginfo_init(&ksi); 3465 ksi.ksi_signo = sig; 3466 ksi.ksi_code = SI_KERNEL; 3467 3468 SIGIO_LOCK(); 3469 sigio = *sigiop; 3470 if (sigio == NULL) { 3471 SIGIO_UNLOCK(); 3472 return; 3473 } 3474 if (sigio->sio_pgid > 0) { 3475 PROC_LOCK(sigio->sio_proc); 3476 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3477 kern_psignal(sigio->sio_proc, sig); 3478 PROC_UNLOCK(sigio->sio_proc); 3479 } else if (sigio->sio_pgid < 0) { 3480 struct proc *p; 3481 3482 PGRP_LOCK(sigio->sio_pgrp); 3483 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3484 PROC_LOCK(p); 3485 if (p->p_state == PRS_NORMAL && 3486 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3487 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3488 kern_psignal(p, sig); 3489 PROC_UNLOCK(p); 3490 } 3491 PGRP_UNLOCK(sigio->sio_pgrp); 3492 } 3493 SIGIO_UNLOCK(); 3494 } 3495 3496 static int 3497 filt_sigattach(struct knote *kn) 3498 { 3499 struct proc *p = curproc; 3500 3501 kn->kn_ptr.p_proc = p; 3502 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3503 3504 knlist_add(&p->p_klist, kn, 0); 3505 3506 return (0); 3507 } 3508 3509 static void 3510 filt_sigdetach(struct knote *kn) 3511 { 3512 struct proc *p = kn->kn_ptr.p_proc; 3513 3514 knlist_remove(&p->p_klist, kn, 0); 3515 } 3516 3517 /* 3518 * signal knotes are shared with proc knotes, so we apply a mask to 3519 * the hint in order to differentiate them from process hints. This 3520 * could be avoided by using a signal-specific knote list, but probably 3521 * isn't worth the trouble. 3522 */ 3523 static int 3524 filt_signal(struct knote *kn, long hint) 3525 { 3526 3527 if (hint & NOTE_SIGNAL) { 3528 hint &= ~NOTE_SIGNAL; 3529 3530 if (kn->kn_id == hint) 3531 kn->kn_data++; 3532 } 3533 return (kn->kn_data != 0); 3534 } 3535 3536 struct sigacts * 3537 sigacts_alloc(void) 3538 { 3539 struct sigacts *ps; 3540 3541 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3542 refcount_init(&ps->ps_refcnt, 1); 3543 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3544 return (ps); 3545 } 3546 3547 void 3548 sigacts_free(struct sigacts *ps) 3549 { 3550 3551 if (refcount_release(&ps->ps_refcnt) == 0) 3552 return; 3553 mtx_destroy(&ps->ps_mtx); 3554 free(ps, M_SUBPROC); 3555 } 3556 3557 struct sigacts * 3558 sigacts_hold(struct sigacts *ps) 3559 { 3560 3561 refcount_acquire(&ps->ps_refcnt); 3562 return (ps); 3563 } 3564 3565 void 3566 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3567 { 3568 3569 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3570 mtx_lock(&src->ps_mtx); 3571 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3572 mtx_unlock(&src->ps_mtx); 3573 } 3574 3575 int 3576 sigacts_shared(struct sigacts *ps) 3577 { 3578 3579 return (ps->ps_refcnt > 1); 3580 } 3581