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 int 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 KASSERT(sig >= 0, ("sig %d", sig)); 1255 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1256 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1257 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1258 error = 0; 1259 break; 1260 } 1261 } 1262 1263 if (error != 0) 1264 break; 1265 1266 /* 1267 * POSIX says this must be checked after looking for pending 1268 * signals. 1269 */ 1270 if (timeout != NULL) { 1271 if (!timevalid) { 1272 error = EINVAL; 1273 break; 1274 } 1275 getnanouptime(&rts); 1276 if (timespeccmp(&rts, &ets, >=)) { 1277 error = EAGAIN; 1278 break; 1279 } 1280 ts = ets; 1281 timespecsub(&ts, &rts); 1282 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1283 timo = tvtohz(&tv); 1284 } else { 1285 timo = 0; 1286 } 1287 1288 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1289 1290 if (timeout != NULL) { 1291 if (error == ERESTART) { 1292 /* Timeout can not be restarted. */ 1293 error = EINTR; 1294 } else if (error == EAGAIN) { 1295 /* We will calculate timeout by ourself. */ 1296 error = 0; 1297 } 1298 } 1299 } 1300 1301 new_block = saved_mask; 1302 SIGSETNAND(new_block, td->td_sigmask); 1303 td->td_sigmask = saved_mask; 1304 /* 1305 * Fewer signals can be delivered to us, reschedule signal 1306 * notification. 1307 */ 1308 if (p->p_numthreads != 1) 1309 reschedule_signals(p, new_block, 0); 1310 1311 if (error == 0) { 1312 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1313 1314 if (ksi->ksi_code == SI_TIMER) 1315 itimer_accept(p, ksi->ksi_timerid, ksi); 1316 1317 #ifdef KTRACE 1318 if (KTRPOINT(td, KTR_PSIG)) { 1319 sig_t action; 1320 1321 mtx_lock(&ps->ps_mtx); 1322 action = ps->ps_sigact[_SIG_IDX(sig)]; 1323 mtx_unlock(&ps->ps_mtx); 1324 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1325 } 1326 #endif 1327 if (sig == SIGKILL) 1328 sigexit(td, sig); 1329 } 1330 PROC_UNLOCK(p); 1331 return (error); 1332 } 1333 1334 #ifndef _SYS_SYSPROTO_H_ 1335 struct sigpending_args { 1336 sigset_t *set; 1337 }; 1338 #endif 1339 int 1340 sys_sigpending(td, uap) 1341 struct thread *td; 1342 struct sigpending_args *uap; 1343 { 1344 struct proc *p = td->td_proc; 1345 sigset_t pending; 1346 1347 PROC_LOCK(p); 1348 pending = p->p_sigqueue.sq_signals; 1349 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1350 PROC_UNLOCK(p); 1351 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1352 } 1353 1354 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1355 #ifndef _SYS_SYSPROTO_H_ 1356 struct osigpending_args { 1357 int dummy; 1358 }; 1359 #endif 1360 int 1361 osigpending(td, uap) 1362 struct thread *td; 1363 struct osigpending_args *uap; 1364 { 1365 struct proc *p = td->td_proc; 1366 sigset_t pending; 1367 1368 PROC_LOCK(p); 1369 pending = p->p_sigqueue.sq_signals; 1370 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1371 PROC_UNLOCK(p); 1372 SIG2OSIG(pending, td->td_retval[0]); 1373 return (0); 1374 } 1375 #endif /* COMPAT_43 */ 1376 1377 #if defined(COMPAT_43) 1378 /* 1379 * Generalized interface signal handler, 4.3-compatible. 1380 */ 1381 #ifndef _SYS_SYSPROTO_H_ 1382 struct osigvec_args { 1383 int signum; 1384 struct sigvec *nsv; 1385 struct sigvec *osv; 1386 }; 1387 #endif 1388 /* ARGSUSED */ 1389 int 1390 osigvec(td, uap) 1391 struct thread *td; 1392 register struct osigvec_args *uap; 1393 { 1394 struct sigvec vec; 1395 struct sigaction nsa, osa; 1396 register struct sigaction *nsap, *osap; 1397 int error; 1398 1399 if (uap->signum <= 0 || uap->signum >= ONSIG) 1400 return (EINVAL); 1401 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1402 osap = (uap->osv != NULL) ? &osa : NULL; 1403 if (nsap) { 1404 error = copyin(uap->nsv, &vec, sizeof(vec)); 1405 if (error) 1406 return (error); 1407 nsap->sa_handler = vec.sv_handler; 1408 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1409 nsap->sa_flags = vec.sv_flags; 1410 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1411 } 1412 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1413 if (osap && !error) { 1414 vec.sv_handler = osap->sa_handler; 1415 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1416 vec.sv_flags = osap->sa_flags; 1417 vec.sv_flags &= ~SA_NOCLDWAIT; 1418 vec.sv_flags ^= SA_RESTART; 1419 error = copyout(&vec, uap->osv, sizeof(vec)); 1420 } 1421 return (error); 1422 } 1423 1424 #ifndef _SYS_SYSPROTO_H_ 1425 struct osigblock_args { 1426 int mask; 1427 }; 1428 #endif 1429 int 1430 osigblock(td, uap) 1431 register struct thread *td; 1432 struct osigblock_args *uap; 1433 { 1434 sigset_t set, oset; 1435 1436 OSIG2SIG(uap->mask, set); 1437 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1438 SIG2OSIG(oset, td->td_retval[0]); 1439 return (0); 1440 } 1441 1442 #ifndef _SYS_SYSPROTO_H_ 1443 struct osigsetmask_args { 1444 int mask; 1445 }; 1446 #endif 1447 int 1448 osigsetmask(td, uap) 1449 struct thread *td; 1450 struct osigsetmask_args *uap; 1451 { 1452 sigset_t set, oset; 1453 1454 OSIG2SIG(uap->mask, set); 1455 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1456 SIG2OSIG(oset, td->td_retval[0]); 1457 return (0); 1458 } 1459 #endif /* COMPAT_43 */ 1460 1461 /* 1462 * Suspend calling thread until signal, providing mask to be set in the 1463 * meantime. 1464 */ 1465 #ifndef _SYS_SYSPROTO_H_ 1466 struct sigsuspend_args { 1467 const sigset_t *sigmask; 1468 }; 1469 #endif 1470 /* ARGSUSED */ 1471 int 1472 sys_sigsuspend(td, uap) 1473 struct thread *td; 1474 struct sigsuspend_args *uap; 1475 { 1476 sigset_t mask; 1477 int error; 1478 1479 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1480 if (error) 1481 return (error); 1482 return (kern_sigsuspend(td, mask)); 1483 } 1484 1485 int 1486 kern_sigsuspend(struct thread *td, sigset_t mask) 1487 { 1488 struct proc *p = td->td_proc; 1489 int has_sig, sig; 1490 1491 /* 1492 * When returning from sigsuspend, we want 1493 * the old mask to be restored after the 1494 * signal handler has finished. Thus, we 1495 * save it here and mark the sigacts structure 1496 * to indicate this. 1497 */ 1498 PROC_LOCK(p); 1499 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1500 SIGPROCMASK_PROC_LOCKED); 1501 td->td_pflags |= TDP_OLDMASK; 1502 1503 /* 1504 * Process signals now. Otherwise, we can get spurious wakeup 1505 * due to signal entered process queue, but delivered to other 1506 * thread. But sigsuspend should return only on signal 1507 * delivery. 1508 */ 1509 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1510 for (has_sig = 0; !has_sig;) { 1511 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1512 0) == 0) 1513 /* void */; 1514 thread_suspend_check(0); 1515 mtx_lock(&p->p_sigacts->ps_mtx); 1516 while ((sig = cursig(td)) != 0) { 1517 KASSERT(sig >= 0, ("sig %d", sig)); 1518 has_sig += postsig(sig); 1519 } 1520 mtx_unlock(&p->p_sigacts->ps_mtx); 1521 } 1522 PROC_UNLOCK(p); 1523 td->td_errno = EINTR; 1524 td->td_pflags |= TDP_NERRNO; 1525 return (EJUSTRETURN); 1526 } 1527 1528 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1529 /* 1530 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1531 * convention: libc stub passes mask, not pointer, to save a copyin. 1532 */ 1533 #ifndef _SYS_SYSPROTO_H_ 1534 struct osigsuspend_args { 1535 osigset_t mask; 1536 }; 1537 #endif 1538 /* ARGSUSED */ 1539 int 1540 osigsuspend(td, uap) 1541 struct thread *td; 1542 struct osigsuspend_args *uap; 1543 { 1544 sigset_t mask; 1545 1546 OSIG2SIG(uap->mask, mask); 1547 return (kern_sigsuspend(td, mask)); 1548 } 1549 #endif /* COMPAT_43 */ 1550 1551 #if defined(COMPAT_43) 1552 #ifndef _SYS_SYSPROTO_H_ 1553 struct osigstack_args { 1554 struct sigstack *nss; 1555 struct sigstack *oss; 1556 }; 1557 #endif 1558 /* ARGSUSED */ 1559 int 1560 osigstack(td, uap) 1561 struct thread *td; 1562 register struct osigstack_args *uap; 1563 { 1564 struct sigstack nss, oss; 1565 int error = 0; 1566 1567 if (uap->nss != NULL) { 1568 error = copyin(uap->nss, &nss, sizeof(nss)); 1569 if (error) 1570 return (error); 1571 } 1572 oss.ss_sp = td->td_sigstk.ss_sp; 1573 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1574 if (uap->nss != NULL) { 1575 td->td_sigstk.ss_sp = nss.ss_sp; 1576 td->td_sigstk.ss_size = 0; 1577 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1578 td->td_pflags |= TDP_ALTSTACK; 1579 } 1580 if (uap->oss != NULL) 1581 error = copyout(&oss, uap->oss, sizeof(oss)); 1582 1583 return (error); 1584 } 1585 #endif /* COMPAT_43 */ 1586 1587 #ifndef _SYS_SYSPROTO_H_ 1588 struct sigaltstack_args { 1589 stack_t *ss; 1590 stack_t *oss; 1591 }; 1592 #endif 1593 /* ARGSUSED */ 1594 int 1595 sys_sigaltstack(td, uap) 1596 struct thread *td; 1597 register struct sigaltstack_args *uap; 1598 { 1599 stack_t ss, oss; 1600 int error; 1601 1602 if (uap->ss != NULL) { 1603 error = copyin(uap->ss, &ss, sizeof(ss)); 1604 if (error) 1605 return (error); 1606 } 1607 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1608 (uap->oss != NULL) ? &oss : NULL); 1609 if (error) 1610 return (error); 1611 if (uap->oss != NULL) 1612 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1613 return (error); 1614 } 1615 1616 int 1617 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1618 { 1619 struct proc *p = td->td_proc; 1620 int oonstack; 1621 1622 oonstack = sigonstack(cpu_getstack(td)); 1623 1624 if (oss != NULL) { 1625 *oss = td->td_sigstk; 1626 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1627 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1628 } 1629 1630 if (ss != NULL) { 1631 if (oonstack) 1632 return (EPERM); 1633 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1634 return (EINVAL); 1635 if (!(ss->ss_flags & SS_DISABLE)) { 1636 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1637 return (ENOMEM); 1638 1639 td->td_sigstk = *ss; 1640 td->td_pflags |= TDP_ALTSTACK; 1641 } else { 1642 td->td_pflags &= ~TDP_ALTSTACK; 1643 } 1644 } 1645 return (0); 1646 } 1647 1648 /* 1649 * Common code for kill process group/broadcast kill. 1650 * cp is calling process. 1651 */ 1652 static int 1653 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1654 { 1655 struct proc *p; 1656 struct pgrp *pgrp; 1657 int err; 1658 int ret; 1659 1660 ret = ESRCH; 1661 if (all) { 1662 /* 1663 * broadcast 1664 */ 1665 sx_slock(&allproc_lock); 1666 FOREACH_PROC_IN_SYSTEM(p) { 1667 PROC_LOCK(p); 1668 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1669 p == td->td_proc || p->p_state == PRS_NEW) { 1670 PROC_UNLOCK(p); 1671 continue; 1672 } 1673 err = p_cansignal(td, p, sig); 1674 if (err == 0) { 1675 if (sig) 1676 pksignal(p, sig, ksi); 1677 ret = err; 1678 } 1679 else if (ret == ESRCH) 1680 ret = err; 1681 PROC_UNLOCK(p); 1682 } 1683 sx_sunlock(&allproc_lock); 1684 } else { 1685 sx_slock(&proctree_lock); 1686 if (pgid == 0) { 1687 /* 1688 * zero pgid means send to my process group. 1689 */ 1690 pgrp = td->td_proc->p_pgrp; 1691 PGRP_LOCK(pgrp); 1692 } else { 1693 pgrp = pgfind(pgid); 1694 if (pgrp == NULL) { 1695 sx_sunlock(&proctree_lock); 1696 return (ESRCH); 1697 } 1698 } 1699 sx_sunlock(&proctree_lock); 1700 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1701 PROC_LOCK(p); 1702 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1703 p->p_state == PRS_NEW) { 1704 PROC_UNLOCK(p); 1705 continue; 1706 } 1707 err = p_cansignal(td, p, sig); 1708 if (err == 0) { 1709 if (sig) 1710 pksignal(p, sig, ksi); 1711 ret = err; 1712 } 1713 else if (ret == ESRCH) 1714 ret = err; 1715 PROC_UNLOCK(p); 1716 } 1717 PGRP_UNLOCK(pgrp); 1718 } 1719 return (ret); 1720 } 1721 1722 #ifndef _SYS_SYSPROTO_H_ 1723 struct kill_args { 1724 int pid; 1725 int signum; 1726 }; 1727 #endif 1728 /* ARGSUSED */ 1729 int 1730 sys_kill(struct thread *td, struct kill_args *uap) 1731 { 1732 ksiginfo_t ksi; 1733 struct proc *p; 1734 int error; 1735 1736 /* 1737 * A process in capability mode can send signals only to himself. 1738 * The main rationale behind this is that abort(3) is implemented as 1739 * kill(getpid(), SIGABRT). 1740 */ 1741 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1742 return (ECAPMODE); 1743 1744 AUDIT_ARG_SIGNUM(uap->signum); 1745 AUDIT_ARG_PID(uap->pid); 1746 if ((u_int)uap->signum > _SIG_MAXSIG) 1747 return (EINVAL); 1748 1749 ksiginfo_init(&ksi); 1750 ksi.ksi_signo = uap->signum; 1751 ksi.ksi_code = SI_USER; 1752 ksi.ksi_pid = td->td_proc->p_pid; 1753 ksi.ksi_uid = td->td_ucred->cr_ruid; 1754 1755 if (uap->pid > 0) { 1756 /* kill single process */ 1757 if ((p = pfind(uap->pid)) == NULL) { 1758 if ((p = zpfind(uap->pid)) == NULL) 1759 return (ESRCH); 1760 } 1761 AUDIT_ARG_PROCESS(p); 1762 error = p_cansignal(td, p, uap->signum); 1763 if (error == 0 && uap->signum) 1764 pksignal(p, uap->signum, &ksi); 1765 PROC_UNLOCK(p); 1766 return (error); 1767 } 1768 switch (uap->pid) { 1769 case -1: /* broadcast signal */ 1770 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1771 case 0: /* signal own process group */ 1772 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1773 default: /* negative explicit process group */ 1774 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1775 } 1776 /* NOTREACHED */ 1777 } 1778 1779 int 1780 sys_pdkill(td, uap) 1781 struct thread *td; 1782 struct pdkill_args *uap; 1783 { 1784 struct proc *p; 1785 cap_rights_t rights; 1786 int error; 1787 1788 AUDIT_ARG_SIGNUM(uap->signum); 1789 AUDIT_ARG_FD(uap->fd); 1790 if ((u_int)uap->signum > _SIG_MAXSIG) 1791 return (EINVAL); 1792 1793 error = procdesc_find(td, uap->fd, 1794 cap_rights_init(&rights, CAP_PDKILL), &p); 1795 if (error) 1796 return (error); 1797 AUDIT_ARG_PROCESS(p); 1798 error = p_cansignal(td, p, uap->signum); 1799 if (error == 0 && uap->signum) 1800 kern_psignal(p, uap->signum); 1801 PROC_UNLOCK(p); 1802 return (error); 1803 } 1804 1805 #if defined(COMPAT_43) 1806 #ifndef _SYS_SYSPROTO_H_ 1807 struct okillpg_args { 1808 int pgid; 1809 int signum; 1810 }; 1811 #endif 1812 /* ARGSUSED */ 1813 int 1814 okillpg(struct thread *td, struct okillpg_args *uap) 1815 { 1816 ksiginfo_t ksi; 1817 1818 AUDIT_ARG_SIGNUM(uap->signum); 1819 AUDIT_ARG_PID(uap->pgid); 1820 if ((u_int)uap->signum > _SIG_MAXSIG) 1821 return (EINVAL); 1822 1823 ksiginfo_init(&ksi); 1824 ksi.ksi_signo = uap->signum; 1825 ksi.ksi_code = SI_USER; 1826 ksi.ksi_pid = td->td_proc->p_pid; 1827 ksi.ksi_uid = td->td_ucred->cr_ruid; 1828 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1829 } 1830 #endif /* COMPAT_43 */ 1831 1832 #ifndef _SYS_SYSPROTO_H_ 1833 struct sigqueue_args { 1834 pid_t pid; 1835 int signum; 1836 /* union sigval */ void *value; 1837 }; 1838 #endif 1839 int 1840 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1841 { 1842 ksiginfo_t ksi; 1843 struct proc *p; 1844 int error; 1845 1846 if ((u_int)uap->signum > _SIG_MAXSIG) 1847 return (EINVAL); 1848 1849 /* 1850 * Specification says sigqueue can only send signal to 1851 * single process. 1852 */ 1853 if (uap->pid <= 0) 1854 return (EINVAL); 1855 1856 if ((p = pfind(uap->pid)) == NULL) { 1857 if ((p = zpfind(uap->pid)) == NULL) 1858 return (ESRCH); 1859 } 1860 error = p_cansignal(td, p, uap->signum); 1861 if (error == 0 && uap->signum != 0) { 1862 ksiginfo_init(&ksi); 1863 ksi.ksi_flags = KSI_SIGQ; 1864 ksi.ksi_signo = uap->signum; 1865 ksi.ksi_code = SI_QUEUE; 1866 ksi.ksi_pid = td->td_proc->p_pid; 1867 ksi.ksi_uid = td->td_ucred->cr_ruid; 1868 ksi.ksi_value.sival_ptr = uap->value; 1869 error = pksignal(p, ksi.ksi_signo, &ksi); 1870 } 1871 PROC_UNLOCK(p); 1872 return (error); 1873 } 1874 1875 /* 1876 * Send a signal to a process group. 1877 */ 1878 void 1879 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1880 { 1881 struct pgrp *pgrp; 1882 1883 if (pgid != 0) { 1884 sx_slock(&proctree_lock); 1885 pgrp = pgfind(pgid); 1886 sx_sunlock(&proctree_lock); 1887 if (pgrp != NULL) { 1888 pgsignal(pgrp, sig, 0, ksi); 1889 PGRP_UNLOCK(pgrp); 1890 } 1891 } 1892 } 1893 1894 /* 1895 * Send a signal to a process group. If checktty is 1, 1896 * limit to members which have a controlling terminal. 1897 */ 1898 void 1899 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1900 { 1901 struct proc *p; 1902 1903 if (pgrp) { 1904 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1905 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1906 PROC_LOCK(p); 1907 if (p->p_state == PRS_NORMAL && 1908 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1909 pksignal(p, sig, ksi); 1910 PROC_UNLOCK(p); 1911 } 1912 } 1913 } 1914 1915 1916 /* 1917 * Recalculate the signal mask and reset the signal disposition after 1918 * usermode frame for delivery is formed. Should be called after 1919 * mach-specific routine, because sysent->sv_sendsig() needs correct 1920 * ps_siginfo and signal mask. 1921 */ 1922 static void 1923 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1924 { 1925 sigset_t mask; 1926 1927 mtx_assert(&ps->ps_mtx, MA_OWNED); 1928 td->td_ru.ru_nsignals++; 1929 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1930 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1931 SIGADDSET(mask, sig); 1932 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1933 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1934 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1935 sigdflt(ps, sig); 1936 } 1937 1938 1939 /* 1940 * Send a signal caused by a trap to the current thread. If it will be 1941 * caught immediately, deliver it with correct code. Otherwise, post it 1942 * normally. 1943 */ 1944 void 1945 trapsignal(struct thread *td, ksiginfo_t *ksi) 1946 { 1947 struct sigacts *ps; 1948 struct proc *p; 1949 int sig; 1950 int code; 1951 1952 p = td->td_proc; 1953 sig = ksi->ksi_signo; 1954 code = ksi->ksi_code; 1955 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1956 1957 PROC_LOCK(p); 1958 ps = p->p_sigacts; 1959 mtx_lock(&ps->ps_mtx); 1960 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1961 !SIGISMEMBER(td->td_sigmask, sig)) { 1962 #ifdef KTRACE 1963 if (KTRPOINT(curthread, KTR_PSIG)) 1964 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1965 &td->td_sigmask, code); 1966 #endif 1967 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1968 ksi, &td->td_sigmask); 1969 postsig_done(sig, td, ps); 1970 mtx_unlock(&ps->ps_mtx); 1971 } else { 1972 /* 1973 * Avoid a possible infinite loop if the thread 1974 * masking the signal or process is ignoring the 1975 * signal. 1976 */ 1977 if (kern_forcesigexit && 1978 (SIGISMEMBER(td->td_sigmask, sig) || 1979 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1980 SIGDELSET(td->td_sigmask, sig); 1981 SIGDELSET(ps->ps_sigcatch, sig); 1982 SIGDELSET(ps->ps_sigignore, sig); 1983 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1984 } 1985 mtx_unlock(&ps->ps_mtx); 1986 p->p_code = code; /* XXX for core dump/debugger */ 1987 p->p_sig = sig; /* XXX to verify code */ 1988 tdsendsignal(p, td, sig, ksi); 1989 } 1990 PROC_UNLOCK(p); 1991 } 1992 1993 static struct thread * 1994 sigtd(struct proc *p, int sig, int prop) 1995 { 1996 struct thread *td, *signal_td; 1997 1998 PROC_LOCK_ASSERT(p, MA_OWNED); 1999 2000 /* 2001 * Check if current thread can handle the signal without 2002 * switching context to another thread. 2003 */ 2004 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2005 return (curthread); 2006 signal_td = NULL; 2007 FOREACH_THREAD_IN_PROC(p, td) { 2008 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2009 signal_td = td; 2010 break; 2011 } 2012 } 2013 if (signal_td == NULL) 2014 signal_td = FIRST_THREAD_IN_PROC(p); 2015 return (signal_td); 2016 } 2017 2018 /* 2019 * Send the signal to the process. If the signal has an action, the action 2020 * is usually performed by the target process rather than the caller; we add 2021 * the signal to the set of pending signals for the process. 2022 * 2023 * Exceptions: 2024 * o When a stop signal is sent to a sleeping process that takes the 2025 * default action, the process is stopped without awakening it. 2026 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2027 * regardless of the signal action (eg, blocked or ignored). 2028 * 2029 * Other ignored signals are discarded immediately. 2030 * 2031 * NB: This function may be entered from the debugger via the "kill" DDB 2032 * command. There is little that can be done to mitigate the possibly messy 2033 * side effects of this unwise possibility. 2034 */ 2035 void 2036 kern_psignal(struct proc *p, int sig) 2037 { 2038 ksiginfo_t ksi; 2039 2040 ksiginfo_init(&ksi); 2041 ksi.ksi_signo = sig; 2042 ksi.ksi_code = SI_KERNEL; 2043 (void) tdsendsignal(p, NULL, sig, &ksi); 2044 } 2045 2046 int 2047 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2048 { 2049 2050 return (tdsendsignal(p, NULL, sig, ksi)); 2051 } 2052 2053 /* Utility function for finding a thread to send signal event to. */ 2054 int 2055 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2056 { 2057 struct thread *td; 2058 2059 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2060 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2061 if (td == NULL) 2062 return (ESRCH); 2063 *ttd = td; 2064 } else { 2065 *ttd = NULL; 2066 PROC_LOCK(p); 2067 } 2068 return (0); 2069 } 2070 2071 void 2072 tdsignal(struct thread *td, int sig) 2073 { 2074 ksiginfo_t ksi; 2075 2076 ksiginfo_init(&ksi); 2077 ksi.ksi_signo = sig; 2078 ksi.ksi_code = SI_KERNEL; 2079 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2080 } 2081 2082 void 2083 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2084 { 2085 2086 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2087 } 2088 2089 int 2090 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2091 { 2092 sig_t action; 2093 sigqueue_t *sigqueue; 2094 int prop; 2095 struct sigacts *ps; 2096 int intrval; 2097 int ret = 0; 2098 int wakeup_swapper; 2099 2100 MPASS(td == NULL || p == td->td_proc); 2101 PROC_LOCK_ASSERT(p, MA_OWNED); 2102 2103 if (!_SIG_VALID(sig)) 2104 panic("%s(): invalid signal %d", __func__, sig); 2105 2106 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2107 2108 /* 2109 * IEEE Std 1003.1-2001: return success when killing a zombie. 2110 */ 2111 if (p->p_state == PRS_ZOMBIE) { 2112 if (ksi && (ksi->ksi_flags & KSI_INS)) 2113 ksiginfo_tryfree(ksi); 2114 return (ret); 2115 } 2116 2117 ps = p->p_sigacts; 2118 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2119 prop = sigprop(sig); 2120 2121 if (td == NULL) { 2122 td = sigtd(p, sig, prop); 2123 sigqueue = &p->p_sigqueue; 2124 } else 2125 sigqueue = &td->td_sigqueue; 2126 2127 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2128 2129 /* 2130 * If the signal is being ignored, 2131 * then we forget about it immediately. 2132 * (Note: we don't set SIGCONT in ps_sigignore, 2133 * and if it is set to SIG_IGN, 2134 * action will be SIG_DFL here.) 2135 */ 2136 mtx_lock(&ps->ps_mtx); 2137 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2138 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2139 2140 mtx_unlock(&ps->ps_mtx); 2141 if (ksi && (ksi->ksi_flags & KSI_INS)) 2142 ksiginfo_tryfree(ksi); 2143 return (ret); 2144 } 2145 if (SIGISMEMBER(td->td_sigmask, sig)) 2146 action = SIG_HOLD; 2147 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2148 action = SIG_CATCH; 2149 else 2150 action = SIG_DFL; 2151 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2152 intrval = EINTR; 2153 else 2154 intrval = ERESTART; 2155 mtx_unlock(&ps->ps_mtx); 2156 2157 if (prop & SA_CONT) 2158 sigqueue_delete_stopmask_proc(p); 2159 else if (prop & SA_STOP) { 2160 /* 2161 * If sending a tty stop signal to a member of an orphaned 2162 * process group, discard the signal here if the action 2163 * is default; don't stop the process below if sleeping, 2164 * and don't clear any pending SIGCONT. 2165 */ 2166 if ((prop & SA_TTYSTOP) && 2167 (p->p_pgrp->pg_jobc == 0) && 2168 (action == SIG_DFL)) { 2169 if (ksi && (ksi->ksi_flags & KSI_INS)) 2170 ksiginfo_tryfree(ksi); 2171 return (ret); 2172 } 2173 sigqueue_delete_proc(p, SIGCONT); 2174 if (p->p_flag & P_CONTINUED) { 2175 p->p_flag &= ~P_CONTINUED; 2176 PROC_LOCK(p->p_pptr); 2177 sigqueue_take(p->p_ksi); 2178 PROC_UNLOCK(p->p_pptr); 2179 } 2180 } 2181 2182 ret = sigqueue_add(sigqueue, sig, ksi); 2183 if (ret != 0) 2184 return (ret); 2185 signotify(td); 2186 /* 2187 * Defer further processing for signals which are held, 2188 * except that stopped processes must be continued by SIGCONT. 2189 */ 2190 if (action == SIG_HOLD && 2191 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2192 return (ret); 2193 /* 2194 * SIGKILL: Remove procfs STOPEVENTs. 2195 */ 2196 if (sig == SIGKILL) { 2197 /* from procfs_ioctl.c: PIOCBIC */ 2198 p->p_stops = 0; 2199 /* from procfs_ioctl.c: PIOCCONT */ 2200 p->p_step = 0; 2201 wakeup(&p->p_step); 2202 } 2203 /* 2204 * Some signals have a process-wide effect and a per-thread 2205 * component. Most processing occurs when the process next 2206 * tries to cross the user boundary, however there are some 2207 * times when processing needs to be done immediately, such as 2208 * waking up threads so that they can cross the user boundary. 2209 * We try to do the per-process part here. 2210 */ 2211 if (P_SHOULDSTOP(p)) { 2212 KASSERT(!(p->p_flag & P_WEXIT), 2213 ("signal to stopped but exiting process")); 2214 if (sig == SIGKILL) { 2215 /* 2216 * If traced process is already stopped, 2217 * then no further action is necessary. 2218 */ 2219 if (p->p_flag & P_TRACED) 2220 goto out; 2221 /* 2222 * SIGKILL sets process running. 2223 * It will die elsewhere. 2224 * All threads must be restarted. 2225 */ 2226 p->p_flag &= ~P_STOPPED_SIG; 2227 goto runfast; 2228 } 2229 2230 if (prop & SA_CONT) { 2231 /* 2232 * If traced process is already stopped, 2233 * then no further action is necessary. 2234 */ 2235 if (p->p_flag & P_TRACED) 2236 goto out; 2237 /* 2238 * If SIGCONT is default (or ignored), we continue the 2239 * process but don't leave the signal in sigqueue as 2240 * it has no further action. If SIGCONT is held, we 2241 * continue the process and leave the signal in 2242 * sigqueue. If the process catches SIGCONT, let it 2243 * handle the signal itself. If it isn't waiting on 2244 * an event, it goes back to run state. 2245 * Otherwise, process goes back to sleep state. 2246 */ 2247 p->p_flag &= ~P_STOPPED_SIG; 2248 PROC_SLOCK(p); 2249 if (p->p_numthreads == p->p_suspcount) { 2250 PROC_SUNLOCK(p); 2251 p->p_flag |= P_CONTINUED; 2252 p->p_xsig = SIGCONT; 2253 PROC_LOCK(p->p_pptr); 2254 childproc_continued(p); 2255 PROC_UNLOCK(p->p_pptr); 2256 PROC_SLOCK(p); 2257 } 2258 if (action == SIG_DFL) { 2259 thread_unsuspend(p); 2260 PROC_SUNLOCK(p); 2261 sigqueue_delete(sigqueue, sig); 2262 goto out; 2263 } 2264 if (action == SIG_CATCH) { 2265 /* 2266 * The process wants to catch it so it needs 2267 * to run at least one thread, but which one? 2268 */ 2269 PROC_SUNLOCK(p); 2270 goto runfast; 2271 } 2272 /* 2273 * The signal is not ignored or caught. 2274 */ 2275 thread_unsuspend(p); 2276 PROC_SUNLOCK(p); 2277 goto out; 2278 } 2279 2280 if (prop & SA_STOP) { 2281 /* 2282 * If traced process is already stopped, 2283 * then no further action is necessary. 2284 */ 2285 if (p->p_flag & P_TRACED) 2286 goto out; 2287 /* 2288 * Already stopped, don't need to stop again 2289 * (If we did the shell could get confused). 2290 * Just make sure the signal STOP bit set. 2291 */ 2292 p->p_flag |= P_STOPPED_SIG; 2293 sigqueue_delete(sigqueue, sig); 2294 goto out; 2295 } 2296 2297 /* 2298 * All other kinds of signals: 2299 * If a thread is sleeping interruptibly, simulate a 2300 * wakeup so that when it is continued it will be made 2301 * runnable and can look at the signal. However, don't make 2302 * the PROCESS runnable, leave it stopped. 2303 * It may run a bit until it hits a thread_suspend_check(). 2304 */ 2305 wakeup_swapper = 0; 2306 PROC_SLOCK(p); 2307 thread_lock(td); 2308 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2309 wakeup_swapper = sleepq_abort(td, intrval); 2310 thread_unlock(td); 2311 PROC_SUNLOCK(p); 2312 if (wakeup_swapper) 2313 kick_proc0(); 2314 goto out; 2315 /* 2316 * Mutexes are short lived. Threads waiting on them will 2317 * hit thread_suspend_check() soon. 2318 */ 2319 } else if (p->p_state == PRS_NORMAL) { 2320 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2321 tdsigwakeup(td, sig, action, intrval); 2322 goto out; 2323 } 2324 2325 MPASS(action == SIG_DFL); 2326 2327 if (prop & SA_STOP) { 2328 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2329 goto out; 2330 p->p_flag |= P_STOPPED_SIG; 2331 p->p_xsig = sig; 2332 PROC_SLOCK(p); 2333 wakeup_swapper = sig_suspend_threads(td, p, 1); 2334 if (p->p_numthreads == p->p_suspcount) { 2335 /* 2336 * only thread sending signal to another 2337 * process can reach here, if thread is sending 2338 * signal to its process, because thread does 2339 * not suspend itself here, p_numthreads 2340 * should never be equal to p_suspcount. 2341 */ 2342 thread_stopped(p); 2343 PROC_SUNLOCK(p); 2344 sigqueue_delete_proc(p, p->p_xsig); 2345 } else 2346 PROC_SUNLOCK(p); 2347 if (wakeup_swapper) 2348 kick_proc0(); 2349 goto out; 2350 } 2351 } else { 2352 /* Not in "NORMAL" state. discard the signal. */ 2353 sigqueue_delete(sigqueue, sig); 2354 goto out; 2355 } 2356 2357 /* 2358 * The process is not stopped so we need to apply the signal to all the 2359 * running threads. 2360 */ 2361 runfast: 2362 tdsigwakeup(td, sig, action, intrval); 2363 PROC_SLOCK(p); 2364 thread_unsuspend(p); 2365 PROC_SUNLOCK(p); 2366 out: 2367 /* If we jump here, proc slock should not be owned. */ 2368 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2369 return (ret); 2370 } 2371 2372 /* 2373 * The force of a signal has been directed against a single 2374 * thread. We need to see what we can do about knocking it 2375 * out of any sleep it may be in etc. 2376 */ 2377 static void 2378 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2379 { 2380 struct proc *p = td->td_proc; 2381 register int prop; 2382 int wakeup_swapper; 2383 2384 wakeup_swapper = 0; 2385 PROC_LOCK_ASSERT(p, MA_OWNED); 2386 prop = sigprop(sig); 2387 2388 PROC_SLOCK(p); 2389 thread_lock(td); 2390 /* 2391 * Bring the priority of a thread up if we want it to get 2392 * killed in this lifetime. Be careful to avoid bumping the 2393 * priority of the idle thread, since we still allow to signal 2394 * kernel processes. 2395 */ 2396 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2397 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2398 sched_prio(td, PUSER); 2399 if (TD_ON_SLEEPQ(td)) { 2400 /* 2401 * If thread is sleeping uninterruptibly 2402 * we can't interrupt the sleep... the signal will 2403 * be noticed when the process returns through 2404 * trap() or syscall(). 2405 */ 2406 if ((td->td_flags & TDF_SINTR) == 0) 2407 goto out; 2408 /* 2409 * If SIGCONT is default (or ignored) and process is 2410 * asleep, we are finished; the process should not 2411 * be awakened. 2412 */ 2413 if ((prop & SA_CONT) && action == SIG_DFL) { 2414 thread_unlock(td); 2415 PROC_SUNLOCK(p); 2416 sigqueue_delete(&p->p_sigqueue, sig); 2417 /* 2418 * It may be on either list in this state. 2419 * Remove from both for now. 2420 */ 2421 sigqueue_delete(&td->td_sigqueue, sig); 2422 return; 2423 } 2424 2425 /* 2426 * Don't awaken a sleeping thread for SIGSTOP if the 2427 * STOP signal is deferred. 2428 */ 2429 if ((prop & SA_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2430 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2431 goto out; 2432 2433 /* 2434 * Give low priority threads a better chance to run. 2435 */ 2436 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2437 sched_prio(td, PUSER); 2438 2439 wakeup_swapper = sleepq_abort(td, intrval); 2440 } else { 2441 /* 2442 * Other states do nothing with the signal immediately, 2443 * other than kicking ourselves if we are running. 2444 * It will either never be noticed, or noticed very soon. 2445 */ 2446 #ifdef SMP 2447 if (TD_IS_RUNNING(td) && td != curthread) 2448 forward_signal(td); 2449 #endif 2450 } 2451 out: 2452 PROC_SUNLOCK(p); 2453 thread_unlock(td); 2454 if (wakeup_swapper) 2455 kick_proc0(); 2456 } 2457 2458 static int 2459 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2460 { 2461 struct thread *td2; 2462 int wakeup_swapper; 2463 2464 PROC_LOCK_ASSERT(p, MA_OWNED); 2465 PROC_SLOCK_ASSERT(p, MA_OWNED); 2466 2467 wakeup_swapper = 0; 2468 FOREACH_THREAD_IN_PROC(p, td2) { 2469 thread_lock(td2); 2470 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2471 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2472 (td2->td_flags & TDF_SINTR)) { 2473 if (td2->td_flags & TDF_SBDRY) { 2474 /* 2475 * Once a thread is asleep with 2476 * TDF_SBDRY and without TDF_SERESTART 2477 * or TDF_SEINTR set, it should never 2478 * become suspended due to this check. 2479 */ 2480 KASSERT(!TD_IS_SUSPENDED(td2), 2481 ("thread with deferred stops suspended")); 2482 if (TD_SBDRY_INTR(td2) && sending) { 2483 wakeup_swapper |= sleepq_abort(td2, 2484 TD_SBDRY_ERRNO(td2)); 2485 } 2486 } else if (!TD_IS_SUSPENDED(td2)) { 2487 thread_suspend_one(td2); 2488 } 2489 } else if (!TD_IS_SUSPENDED(td2)) { 2490 if (sending || td != td2) 2491 td2->td_flags |= TDF_ASTPENDING; 2492 #ifdef SMP 2493 if (TD_IS_RUNNING(td2) && td2 != td) 2494 forward_signal(td2); 2495 #endif 2496 } 2497 thread_unlock(td2); 2498 } 2499 return (wakeup_swapper); 2500 } 2501 2502 int 2503 ptracestop(struct thread *td, int sig) 2504 { 2505 struct proc *p = td->td_proc; 2506 2507 PROC_LOCK_ASSERT(p, MA_OWNED); 2508 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2509 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2510 &p->p_mtx.lock_object, "Stopping for traced signal"); 2511 2512 td->td_dbgflags |= TDB_XSIG; 2513 td->td_xsig = sig; 2514 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2515 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2516 PROC_SLOCK(p); 2517 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2518 if (p->p_flag & P_SINGLE_EXIT && 2519 !(td->td_dbgflags & TDB_EXIT)) { 2520 /* 2521 * Ignore ptrace stops except for thread exit 2522 * events when the process exits. 2523 */ 2524 td->td_dbgflags &= ~TDB_XSIG; 2525 PROC_SUNLOCK(p); 2526 return (sig); 2527 } 2528 /* 2529 * Just make wait() to work, the last stopped thread 2530 * will win. 2531 */ 2532 p->p_xsig = sig; 2533 p->p_xthread = td; 2534 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2535 sig_suspend_threads(td, p, 0); 2536 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2537 td->td_dbgflags &= ~TDB_STOPATFORK; 2538 cv_broadcast(&p->p_dbgwait); 2539 } 2540 stopme: 2541 thread_suspend_switch(td, p); 2542 if (p->p_xthread == td) 2543 p->p_xthread = NULL; 2544 if (!(p->p_flag & P_TRACED)) 2545 break; 2546 if (td->td_dbgflags & TDB_SUSPEND) { 2547 if (p->p_flag & P_SINGLE_EXIT) 2548 break; 2549 goto stopme; 2550 } 2551 } 2552 PROC_SUNLOCK(p); 2553 return (td->td_xsig); 2554 } 2555 2556 static void 2557 reschedule_signals(struct proc *p, sigset_t block, int flags) 2558 { 2559 struct sigacts *ps; 2560 struct thread *td; 2561 int sig; 2562 2563 PROC_LOCK_ASSERT(p, MA_OWNED); 2564 ps = p->p_sigacts; 2565 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2566 MA_OWNED : MA_NOTOWNED); 2567 if (SIGISEMPTY(p->p_siglist)) 2568 return; 2569 SIGSETAND(block, p->p_siglist); 2570 while ((sig = sig_ffs(&block)) != 0) { 2571 SIGDELSET(block, sig); 2572 td = sigtd(p, sig, 0); 2573 signotify(td); 2574 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2575 mtx_lock(&ps->ps_mtx); 2576 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2577 tdsigwakeup(td, sig, SIG_CATCH, 2578 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2579 ERESTART)); 2580 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2581 mtx_unlock(&ps->ps_mtx); 2582 } 2583 } 2584 2585 void 2586 tdsigcleanup(struct thread *td) 2587 { 2588 struct proc *p; 2589 sigset_t unblocked; 2590 2591 p = td->td_proc; 2592 PROC_LOCK_ASSERT(p, MA_OWNED); 2593 2594 sigqueue_flush(&td->td_sigqueue); 2595 if (p->p_numthreads == 1) 2596 return; 2597 2598 /* 2599 * Since we cannot handle signals, notify signal post code 2600 * about this by filling the sigmask. 2601 * 2602 * Also, if needed, wake up thread(s) that do not block the 2603 * same signals as the exiting thread, since the thread might 2604 * have been selected for delivery and woken up. 2605 */ 2606 SIGFILLSET(unblocked); 2607 SIGSETNAND(unblocked, td->td_sigmask); 2608 SIGFILLSET(td->td_sigmask); 2609 reschedule_signals(p, unblocked, 0); 2610 2611 } 2612 2613 static int 2614 sigdeferstop_curr_flags(int cflags) 2615 { 2616 2617 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2618 (cflags & TDF_SBDRY) != 0); 2619 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2620 } 2621 2622 /* 2623 * Defer the delivery of SIGSTOP for the current thread, according to 2624 * the requested mode. Returns previous flags, which must be restored 2625 * by sigallowstop(). 2626 * 2627 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2628 * cleared by the current thread, which allow the lock-less read-only 2629 * accesses below. 2630 */ 2631 int 2632 sigdeferstop_impl(int mode) 2633 { 2634 struct thread *td; 2635 int cflags, nflags; 2636 2637 td = curthread; 2638 cflags = sigdeferstop_curr_flags(td->td_flags); 2639 switch (mode) { 2640 case SIGDEFERSTOP_NOP: 2641 nflags = cflags; 2642 break; 2643 case SIGDEFERSTOP_OFF: 2644 nflags = 0; 2645 break; 2646 case SIGDEFERSTOP_SILENT: 2647 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2648 break; 2649 case SIGDEFERSTOP_EINTR: 2650 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2651 break; 2652 case SIGDEFERSTOP_ERESTART: 2653 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2654 break; 2655 default: 2656 panic("sigdeferstop: invalid mode %x", mode); 2657 break; 2658 } 2659 if (cflags == nflags) 2660 return (SIGDEFERSTOP_VAL_NCHG); 2661 thread_lock(td); 2662 td->td_flags = (td->td_flags & ~cflags) | nflags; 2663 thread_unlock(td); 2664 return (cflags); 2665 } 2666 2667 /* 2668 * Restores the STOP handling mode, typically permitting the delivery 2669 * of SIGSTOP for the current thread. This does not immediately 2670 * suspend if a stop was posted. Instead, the thread will suspend 2671 * either via ast() or a subsequent interruptible sleep. 2672 */ 2673 void 2674 sigallowstop_impl(int prev) 2675 { 2676 struct thread *td; 2677 int cflags; 2678 2679 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2680 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2681 ("sigallowstop: incorrect previous mode %x", prev)); 2682 td = curthread; 2683 cflags = sigdeferstop_curr_flags(td->td_flags); 2684 if (cflags != prev) { 2685 thread_lock(td); 2686 td->td_flags = (td->td_flags & ~cflags) | prev; 2687 thread_unlock(td); 2688 } 2689 } 2690 2691 /* 2692 * If the current process has received a signal (should be caught or cause 2693 * termination, should interrupt current syscall), return the signal number. 2694 * Stop signals with default action are processed immediately, then cleared; 2695 * they aren't returned. This is checked after each entry to the system for 2696 * a syscall or trap (though this can usually be done without calling issignal 2697 * by checking the pending signal masks in cursig.) The normal call 2698 * sequence is 2699 * 2700 * while (sig = cursig(curthread)) 2701 * postsig(sig); 2702 */ 2703 static int 2704 issignal(struct thread *td) 2705 { 2706 struct proc *p; 2707 struct sigacts *ps; 2708 struct sigqueue *queue; 2709 sigset_t sigpending; 2710 int sig, prop, newsig; 2711 2712 p = td->td_proc; 2713 ps = p->p_sigacts; 2714 mtx_assert(&ps->ps_mtx, MA_OWNED); 2715 PROC_LOCK_ASSERT(p, MA_OWNED); 2716 for (;;) { 2717 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2718 2719 sigpending = td->td_sigqueue.sq_signals; 2720 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2721 SIGSETNAND(sigpending, td->td_sigmask); 2722 2723 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2724 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2725 SIG_STOPSIGMASK(sigpending); 2726 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2727 return (0); 2728 sig = sig_ffs(&sigpending); 2729 2730 if (p->p_stops & S_SIG) { 2731 mtx_unlock(&ps->ps_mtx); 2732 stopevent(p, S_SIG, sig); 2733 mtx_lock(&ps->ps_mtx); 2734 } 2735 2736 /* 2737 * We should see pending but ignored signals 2738 * only if P_TRACED was on when they were posted. 2739 */ 2740 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2741 sigqueue_delete(&td->td_sigqueue, sig); 2742 sigqueue_delete(&p->p_sigqueue, sig); 2743 continue; 2744 } 2745 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2746 /* 2747 * If traced, always stop. 2748 * Remove old signal from queue before the stop. 2749 * XXX shrug off debugger, it causes siginfo to 2750 * be thrown away. 2751 */ 2752 queue = &td->td_sigqueue; 2753 td->td_dbgksi.ksi_signo = 0; 2754 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2755 queue = &p->p_sigqueue; 2756 sigqueue_get(queue, sig, &td->td_dbgksi); 2757 } 2758 2759 mtx_unlock(&ps->ps_mtx); 2760 newsig = ptracestop(td, sig); 2761 mtx_lock(&ps->ps_mtx); 2762 2763 if (sig != newsig) { 2764 2765 /* 2766 * If parent wants us to take the signal, 2767 * then it will leave it in p->p_xsig; 2768 * otherwise we just look for signals again. 2769 */ 2770 if (newsig == 0) 2771 continue; 2772 sig = newsig; 2773 2774 /* 2775 * Put the new signal into td_sigqueue. If the 2776 * signal is being masked, look for other 2777 * signals. 2778 */ 2779 sigqueue_add(queue, sig, NULL); 2780 if (SIGISMEMBER(td->td_sigmask, sig)) 2781 continue; 2782 signotify(td); 2783 } else { 2784 if (td->td_dbgksi.ksi_signo != 0) { 2785 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2786 if (sigqueue_add(&td->td_sigqueue, sig, 2787 &td->td_dbgksi) != 0) 2788 td->td_dbgksi.ksi_signo = 0; 2789 } 2790 if (td->td_dbgksi.ksi_signo == 0) 2791 sigqueue_add(&td->td_sigqueue, sig, 2792 NULL); 2793 } 2794 2795 /* 2796 * If the traced bit got turned off, go back up 2797 * to the top to rescan signals. This ensures 2798 * that p_sig* and p_sigact are consistent. 2799 */ 2800 if ((p->p_flag & P_TRACED) == 0) 2801 continue; 2802 } 2803 2804 prop = sigprop(sig); 2805 2806 /* 2807 * Decide whether the signal should be returned. 2808 * Return the signal's number, or fall through 2809 * to clear it from the pending mask. 2810 */ 2811 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2812 2813 case (intptr_t)SIG_DFL: 2814 /* 2815 * Don't take default actions on system processes. 2816 */ 2817 if (p->p_pid <= 1) { 2818 #ifdef DIAGNOSTIC 2819 /* 2820 * Are you sure you want to ignore SIGSEGV 2821 * in init? XXX 2822 */ 2823 printf("Process (pid %lu) got signal %d\n", 2824 (u_long)p->p_pid, sig); 2825 #endif 2826 break; /* == ignore */ 2827 } 2828 /* 2829 * If there is a pending stop signal to process 2830 * with default action, stop here, 2831 * then clear the signal. However, 2832 * if process is member of an orphaned 2833 * process group, ignore tty stop signals. 2834 */ 2835 if (prop & SA_STOP) { 2836 if (p->p_flag & (P_TRACED|P_WEXIT) || 2837 (p->p_pgrp->pg_jobc == 0 && 2838 prop & SA_TTYSTOP)) 2839 break; /* == ignore */ 2840 if (TD_SBDRY_INTR(td)) { 2841 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2842 ("lost TDF_SBDRY")); 2843 return (-1); 2844 } 2845 mtx_unlock(&ps->ps_mtx); 2846 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2847 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2848 p->p_flag |= P_STOPPED_SIG; 2849 p->p_xsig = sig; 2850 PROC_SLOCK(p); 2851 sig_suspend_threads(td, p, 0); 2852 thread_suspend_switch(td, p); 2853 PROC_SUNLOCK(p); 2854 mtx_lock(&ps->ps_mtx); 2855 break; 2856 } else if (prop & SA_IGNORE) { 2857 /* 2858 * Except for SIGCONT, shouldn't get here. 2859 * Default action is to ignore; drop it. 2860 */ 2861 break; /* == ignore */ 2862 } else 2863 return (sig); 2864 /*NOTREACHED*/ 2865 2866 case (intptr_t)SIG_IGN: 2867 /* 2868 * Masking above should prevent us ever trying 2869 * to take action on an ignored signal other 2870 * than SIGCONT, unless process is traced. 2871 */ 2872 if ((prop & SA_CONT) == 0 && 2873 (p->p_flag & P_TRACED) == 0) 2874 printf("issignal\n"); 2875 break; /* == ignore */ 2876 2877 default: 2878 /* 2879 * This signal has an action, let 2880 * postsig() process it. 2881 */ 2882 return (sig); 2883 } 2884 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2885 sigqueue_delete(&p->p_sigqueue, sig); 2886 } 2887 /* NOTREACHED */ 2888 } 2889 2890 void 2891 thread_stopped(struct proc *p) 2892 { 2893 int n; 2894 2895 PROC_LOCK_ASSERT(p, MA_OWNED); 2896 PROC_SLOCK_ASSERT(p, MA_OWNED); 2897 n = p->p_suspcount; 2898 if (p == curproc) 2899 n++; 2900 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2901 PROC_SUNLOCK(p); 2902 p->p_flag &= ~P_WAITED; 2903 PROC_LOCK(p->p_pptr); 2904 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2905 CLD_TRAPPED : CLD_STOPPED); 2906 PROC_UNLOCK(p->p_pptr); 2907 PROC_SLOCK(p); 2908 } 2909 } 2910 2911 /* 2912 * Take the action for the specified signal 2913 * from the current set of pending signals. 2914 */ 2915 int 2916 postsig(sig) 2917 register int sig; 2918 { 2919 struct thread *td = curthread; 2920 register struct proc *p = td->td_proc; 2921 struct sigacts *ps; 2922 sig_t action; 2923 ksiginfo_t ksi; 2924 sigset_t returnmask; 2925 2926 KASSERT(sig != 0, ("postsig")); 2927 2928 PROC_LOCK_ASSERT(p, MA_OWNED); 2929 ps = p->p_sigacts; 2930 mtx_assert(&ps->ps_mtx, MA_OWNED); 2931 ksiginfo_init(&ksi); 2932 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2933 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2934 return (0); 2935 ksi.ksi_signo = sig; 2936 if (ksi.ksi_code == SI_TIMER) 2937 itimer_accept(p, ksi.ksi_timerid, &ksi); 2938 action = ps->ps_sigact[_SIG_IDX(sig)]; 2939 #ifdef KTRACE 2940 if (KTRPOINT(td, KTR_PSIG)) 2941 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2942 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2943 #endif 2944 if (p->p_stops & S_SIG) { 2945 mtx_unlock(&ps->ps_mtx); 2946 stopevent(p, S_SIG, sig); 2947 mtx_lock(&ps->ps_mtx); 2948 } 2949 2950 if (action == SIG_DFL) { 2951 /* 2952 * Default action, where the default is to kill 2953 * the process. (Other cases were ignored above.) 2954 */ 2955 mtx_unlock(&ps->ps_mtx); 2956 sigexit(td, sig); 2957 /* NOTREACHED */ 2958 } else { 2959 /* 2960 * If we get here, the signal must be caught. 2961 */ 2962 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2963 ("postsig action")); 2964 /* 2965 * Set the new mask value and also defer further 2966 * occurrences of this signal. 2967 * 2968 * Special case: user has done a sigsuspend. Here the 2969 * current mask is not of interest, but rather the 2970 * mask from before the sigsuspend is what we want 2971 * restored after the signal processing is completed. 2972 */ 2973 if (td->td_pflags & TDP_OLDMASK) { 2974 returnmask = td->td_oldsigmask; 2975 td->td_pflags &= ~TDP_OLDMASK; 2976 } else 2977 returnmask = td->td_sigmask; 2978 2979 if (p->p_sig == sig) { 2980 p->p_code = 0; 2981 p->p_sig = 0; 2982 } 2983 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2984 postsig_done(sig, td, ps); 2985 } 2986 return (1); 2987 } 2988 2989 /* 2990 * Kill the current process for stated reason. 2991 */ 2992 void 2993 killproc(p, why) 2994 struct proc *p; 2995 char *why; 2996 { 2997 2998 PROC_LOCK_ASSERT(p, MA_OWNED); 2999 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3000 p->p_comm); 3001 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3002 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3003 p->p_flag |= P_WKILLED; 3004 kern_psignal(p, SIGKILL); 3005 } 3006 3007 /* 3008 * Force the current process to exit with the specified signal, dumping core 3009 * if appropriate. We bypass the normal tests for masked and caught signals, 3010 * allowing unrecoverable failures to terminate the process without changing 3011 * signal state. Mark the accounting record with the signal termination. 3012 * If dumping core, save the signal number for the debugger. Calls exit and 3013 * does not return. 3014 */ 3015 void 3016 sigexit(td, sig) 3017 struct thread *td; 3018 int sig; 3019 { 3020 struct proc *p = td->td_proc; 3021 3022 PROC_LOCK_ASSERT(p, MA_OWNED); 3023 p->p_acflag |= AXSIG; 3024 /* 3025 * We must be single-threading to generate a core dump. This 3026 * ensures that the registers in the core file are up-to-date. 3027 * Also, the ELF dump handler assumes that the thread list doesn't 3028 * change out from under it. 3029 * 3030 * XXX If another thread attempts to single-thread before us 3031 * (e.g. via fork()), we won't get a dump at all. 3032 */ 3033 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 3034 p->p_sig = sig; 3035 /* 3036 * Log signals which would cause core dumps 3037 * (Log as LOG_INFO to appease those who don't want 3038 * these messages.) 3039 * XXX : Todo, as well as euid, write out ruid too 3040 * Note that coredump() drops proc lock. 3041 */ 3042 if (coredump(td) == 0) 3043 sig |= WCOREFLAG; 3044 if (kern_logsigexit) 3045 log(LOG_INFO, 3046 "pid %d (%s), uid %d: exited on signal %d%s\n", 3047 p->p_pid, p->p_comm, 3048 td->td_ucred ? td->td_ucred->cr_uid : -1, 3049 sig &~ WCOREFLAG, 3050 sig & WCOREFLAG ? " (core dumped)" : ""); 3051 } else 3052 PROC_UNLOCK(p); 3053 exit1(td, 0, sig); 3054 /* NOTREACHED */ 3055 } 3056 3057 /* 3058 * Send queued SIGCHLD to parent when child process's state 3059 * is changed. 3060 */ 3061 static void 3062 sigparent(struct proc *p, int reason, int status) 3063 { 3064 PROC_LOCK_ASSERT(p, MA_OWNED); 3065 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3066 3067 if (p->p_ksi != NULL) { 3068 p->p_ksi->ksi_signo = SIGCHLD; 3069 p->p_ksi->ksi_code = reason; 3070 p->p_ksi->ksi_status = status; 3071 p->p_ksi->ksi_pid = p->p_pid; 3072 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3073 if (KSI_ONQ(p->p_ksi)) 3074 return; 3075 } 3076 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3077 } 3078 3079 static void 3080 childproc_jobstate(struct proc *p, int reason, int sig) 3081 { 3082 struct sigacts *ps; 3083 3084 PROC_LOCK_ASSERT(p, MA_OWNED); 3085 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3086 3087 /* 3088 * Wake up parent sleeping in kern_wait(), also send 3089 * SIGCHLD to parent, but SIGCHLD does not guarantee 3090 * that parent will awake, because parent may masked 3091 * the signal. 3092 */ 3093 p->p_pptr->p_flag |= P_STATCHILD; 3094 wakeup(p->p_pptr); 3095 3096 ps = p->p_pptr->p_sigacts; 3097 mtx_lock(&ps->ps_mtx); 3098 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3099 mtx_unlock(&ps->ps_mtx); 3100 sigparent(p, reason, sig); 3101 } else 3102 mtx_unlock(&ps->ps_mtx); 3103 } 3104 3105 void 3106 childproc_stopped(struct proc *p, int reason) 3107 { 3108 3109 childproc_jobstate(p, reason, p->p_xsig); 3110 } 3111 3112 void 3113 childproc_continued(struct proc *p) 3114 { 3115 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3116 } 3117 3118 void 3119 childproc_exited(struct proc *p) 3120 { 3121 int reason, status; 3122 3123 if (WCOREDUMP(p->p_xsig)) { 3124 reason = CLD_DUMPED; 3125 status = WTERMSIG(p->p_xsig); 3126 } else if (WIFSIGNALED(p->p_xsig)) { 3127 reason = CLD_KILLED; 3128 status = WTERMSIG(p->p_xsig); 3129 } else { 3130 reason = CLD_EXITED; 3131 status = p->p_xexit; 3132 } 3133 /* 3134 * XXX avoid calling wakeup(p->p_pptr), the work is 3135 * done in exit1(). 3136 */ 3137 sigparent(p, reason, status); 3138 } 3139 3140 /* 3141 * We only have 1 character for the core count in the format 3142 * string, so the range will be 0-9 3143 */ 3144 #define MAX_NUM_CORES 10 3145 static int num_cores = 5; 3146 3147 static int 3148 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3149 { 3150 int error; 3151 int new_val; 3152 3153 new_val = num_cores; 3154 error = sysctl_handle_int(oidp, &new_val, 0, req); 3155 if (error != 0 || req->newptr == NULL) 3156 return (error); 3157 if (new_val > MAX_NUM_CORES) 3158 new_val = MAX_NUM_CORES; 3159 if (new_val < 0) 3160 new_val = 0; 3161 num_cores = new_val; 3162 return (0); 3163 } 3164 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3165 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3166 3167 #define GZ_SUFFIX ".gz" 3168 3169 #ifdef GZIO 3170 static int compress_user_cores = 1; 3171 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN, 3172 &compress_user_cores, 0, "Compression of user corefiles"); 3173 3174 int compress_user_cores_gzlevel = 6; 3175 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN, 3176 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level"); 3177 #else 3178 static int compress_user_cores = 0; 3179 #endif 3180 3181 /* 3182 * Protect the access to corefilename[] by allproc_lock. 3183 */ 3184 #define corefilename_lock allproc_lock 3185 3186 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3187 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3188 3189 static int 3190 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3191 { 3192 int error; 3193 3194 sx_xlock(&corefilename_lock); 3195 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3196 req); 3197 sx_xunlock(&corefilename_lock); 3198 3199 return (error); 3200 } 3201 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3202 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3203 "Process corefile name format string"); 3204 3205 /* 3206 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3207 * Expand the name described in corefilename, using name, uid, and pid 3208 * and open/create core file. 3209 * corefilename is a printf-like string, with three format specifiers: 3210 * %N name of process ("name") 3211 * %P process id (pid) 3212 * %U user id (uid) 3213 * For example, "%N.core" is the default; they can be disabled completely 3214 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3215 * This is controlled by the sysctl variable kern.corefile (see above). 3216 */ 3217 static int 3218 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3219 int compress, struct vnode **vpp, char **namep) 3220 { 3221 struct nameidata nd; 3222 struct sbuf sb; 3223 const char *format; 3224 char *hostname, *name; 3225 int indexpos, i, error, cmode, flags, oflags; 3226 3227 hostname = NULL; 3228 format = corefilename; 3229 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3230 indexpos = -1; 3231 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3232 sx_slock(&corefilename_lock); 3233 for (i = 0; format[i] != '\0'; i++) { 3234 switch (format[i]) { 3235 case '%': /* Format character */ 3236 i++; 3237 switch (format[i]) { 3238 case '%': 3239 sbuf_putc(&sb, '%'); 3240 break; 3241 case 'H': /* hostname */ 3242 if (hostname == NULL) { 3243 hostname = malloc(MAXHOSTNAMELEN, 3244 M_TEMP, M_WAITOK); 3245 } 3246 getcredhostname(td->td_ucred, hostname, 3247 MAXHOSTNAMELEN); 3248 sbuf_printf(&sb, "%s", hostname); 3249 break; 3250 case 'I': /* autoincrementing index */ 3251 sbuf_printf(&sb, "0"); 3252 indexpos = sbuf_len(&sb) - 1; 3253 break; 3254 case 'N': /* process name */ 3255 sbuf_printf(&sb, "%s", comm); 3256 break; 3257 case 'P': /* process id */ 3258 sbuf_printf(&sb, "%u", pid); 3259 break; 3260 case 'U': /* user id */ 3261 sbuf_printf(&sb, "%u", uid); 3262 break; 3263 default: 3264 log(LOG_ERR, 3265 "Unknown format character %c in " 3266 "corename `%s'\n", format[i], format); 3267 break; 3268 } 3269 break; 3270 default: 3271 sbuf_putc(&sb, format[i]); 3272 break; 3273 } 3274 } 3275 sx_sunlock(&corefilename_lock); 3276 free(hostname, M_TEMP); 3277 if (compress) 3278 sbuf_printf(&sb, GZ_SUFFIX); 3279 if (sbuf_error(&sb) != 0) { 3280 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3281 "long\n", (long)pid, comm, (u_long)uid); 3282 sbuf_delete(&sb); 3283 free(name, M_TEMP); 3284 return (ENOMEM); 3285 } 3286 sbuf_finish(&sb); 3287 sbuf_delete(&sb); 3288 3289 cmode = S_IRUSR | S_IWUSR; 3290 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3291 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3292 3293 /* 3294 * If the core format has a %I in it, then we need to check 3295 * for existing corefiles before returning a name. 3296 * To do this we iterate over 0..num_cores to find a 3297 * non-existing core file name to use. 3298 */ 3299 if (indexpos != -1) { 3300 for (i = 0; i < num_cores; i++) { 3301 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3302 name[indexpos] = '0' + i; 3303 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3304 error = vn_open_cred(&nd, &flags, cmode, oflags, 3305 td->td_ucred, NULL); 3306 if (error) { 3307 if (error == EEXIST) 3308 continue; 3309 log(LOG_ERR, 3310 "pid %d (%s), uid (%u): Path `%s' failed " 3311 "on initial open test, error = %d\n", 3312 pid, comm, uid, name, error); 3313 } 3314 goto out; 3315 } 3316 } 3317 3318 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3319 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3320 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3321 out: 3322 if (error) { 3323 #ifdef AUDIT 3324 audit_proc_coredump(td, name, error); 3325 #endif 3326 free(name, M_TEMP); 3327 return (error); 3328 } 3329 NDFREE(&nd, NDF_ONLY_PNBUF); 3330 *vpp = nd.ni_vp; 3331 *namep = name; 3332 return (0); 3333 } 3334 3335 static int 3336 coredump_sanitise_path(const char *path) 3337 { 3338 size_t i; 3339 3340 /* 3341 * Only send a subset of ASCII to devd(8) because it 3342 * might pass these strings to sh -c. 3343 */ 3344 for (i = 0; path[i]; i++) 3345 if (!(isalpha(path[i]) || isdigit(path[i])) && 3346 path[i] != '/' && path[i] != '.' && 3347 path[i] != '-') 3348 return (0); 3349 3350 return (1); 3351 } 3352 3353 /* 3354 * Dump a process' core. The main routine does some 3355 * policy checking, and creates the name of the coredump; 3356 * then it passes on a vnode and a size limit to the process-specific 3357 * coredump routine if there is one; if there _is not_ one, it returns 3358 * ENOSYS; otherwise it returns the error from the process-specific routine. 3359 */ 3360 3361 static int 3362 coredump(struct thread *td) 3363 { 3364 struct proc *p = td->td_proc; 3365 struct ucred *cred = td->td_ucred; 3366 struct vnode *vp; 3367 struct flock lf; 3368 struct vattr vattr; 3369 int error, error1, locked; 3370 char *name; /* name of corefile */ 3371 void *rl_cookie; 3372 off_t limit; 3373 char *data = NULL; 3374 char *fullpath, *freepath = NULL; 3375 size_t len; 3376 static const char comm_name[] = "comm="; 3377 static const char core_name[] = "core="; 3378 3379 PROC_LOCK_ASSERT(p, MA_OWNED); 3380 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3381 _STOPEVENT(p, S_CORE, 0); 3382 3383 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3384 (p->p_flag2 & P2_NOTRACE) != 0) { 3385 PROC_UNLOCK(p); 3386 return (EFAULT); 3387 } 3388 3389 /* 3390 * Note that the bulk of limit checking is done after 3391 * the corefile is created. The exception is if the limit 3392 * for corefiles is 0, in which case we don't bother 3393 * creating the corefile at all. This layout means that 3394 * a corefile is truncated instead of not being created, 3395 * if it is larger than the limit. 3396 */ 3397 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3398 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3399 PROC_UNLOCK(p); 3400 return (EFBIG); 3401 } 3402 PROC_UNLOCK(p); 3403 3404 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3405 compress_user_cores, &vp, &name); 3406 if (error != 0) 3407 return (error); 3408 3409 /* 3410 * Don't dump to non-regular files or files with links. 3411 * Do not dump into system files. 3412 */ 3413 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3414 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3415 VOP_UNLOCK(vp, 0); 3416 error = EFAULT; 3417 goto out; 3418 } 3419 3420 VOP_UNLOCK(vp, 0); 3421 3422 /* Postpone other writers, including core dumps of other processes. */ 3423 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3424 3425 lf.l_whence = SEEK_SET; 3426 lf.l_start = 0; 3427 lf.l_len = 0; 3428 lf.l_type = F_WRLCK; 3429 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3430 3431 VATTR_NULL(&vattr); 3432 vattr.va_size = 0; 3433 if (set_core_nodump_flag) 3434 vattr.va_flags = UF_NODUMP; 3435 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3436 VOP_SETATTR(vp, &vattr, cred); 3437 VOP_UNLOCK(vp, 0); 3438 PROC_LOCK(p); 3439 p->p_acflag |= ACORE; 3440 PROC_UNLOCK(p); 3441 3442 if (p->p_sysent->sv_coredump != NULL) { 3443 error = p->p_sysent->sv_coredump(td, vp, limit, 3444 compress_user_cores ? IMGACT_CORE_COMPRESS : 0); 3445 } else { 3446 error = ENOSYS; 3447 } 3448 3449 if (locked) { 3450 lf.l_type = F_UNLCK; 3451 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3452 } 3453 vn_rangelock_unlock(vp, rl_cookie); 3454 3455 /* 3456 * Notify the userland helper that a process triggered a core dump. 3457 * This allows the helper to run an automated debugging session. 3458 */ 3459 if (error != 0 || coredump_devctl == 0) 3460 goto out; 3461 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3462 sizeof(' ') + sizeof(core_name) - 1; 3463 data = malloc(len, M_TEMP, M_WAITOK); 3464 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3465 goto out; 3466 if (!coredump_sanitise_path(fullpath)) 3467 goto out; 3468 snprintf(data, len, "%s%s ", comm_name, fullpath); 3469 free(freepath, M_TEMP); 3470 freepath = NULL; 3471 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3472 goto out; 3473 if (!coredump_sanitise_path(fullpath)) 3474 goto out; 3475 strlcat(data, core_name, len); 3476 strlcat(data, fullpath, len); 3477 devctl_notify("kernel", "signal", "coredump", data); 3478 out: 3479 error1 = vn_close(vp, FWRITE, cred, td); 3480 if (error == 0) 3481 error = error1; 3482 #ifdef AUDIT 3483 audit_proc_coredump(td, name, error); 3484 #endif 3485 free(freepath, M_TEMP); 3486 free(data, M_TEMP); 3487 free(name, M_TEMP); 3488 return (error); 3489 } 3490 3491 /* 3492 * Nonexistent system call-- signal process (may want to handle it). Flag 3493 * error in case process won't see signal immediately (blocked or ignored). 3494 */ 3495 #ifndef _SYS_SYSPROTO_H_ 3496 struct nosys_args { 3497 int dummy; 3498 }; 3499 #endif 3500 /* ARGSUSED */ 3501 int 3502 nosys(td, args) 3503 struct thread *td; 3504 struct nosys_args *args; 3505 { 3506 struct proc *p = td->td_proc; 3507 3508 PROC_LOCK(p); 3509 tdsignal(td, SIGSYS); 3510 PROC_UNLOCK(p); 3511 return (ENOSYS); 3512 } 3513 3514 /* 3515 * Send a SIGIO or SIGURG signal to a process or process group using stored 3516 * credentials rather than those of the current process. 3517 */ 3518 void 3519 pgsigio(sigiop, sig, checkctty) 3520 struct sigio **sigiop; 3521 int sig, checkctty; 3522 { 3523 ksiginfo_t ksi; 3524 struct sigio *sigio; 3525 3526 ksiginfo_init(&ksi); 3527 ksi.ksi_signo = sig; 3528 ksi.ksi_code = SI_KERNEL; 3529 3530 SIGIO_LOCK(); 3531 sigio = *sigiop; 3532 if (sigio == NULL) { 3533 SIGIO_UNLOCK(); 3534 return; 3535 } 3536 if (sigio->sio_pgid > 0) { 3537 PROC_LOCK(sigio->sio_proc); 3538 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3539 kern_psignal(sigio->sio_proc, sig); 3540 PROC_UNLOCK(sigio->sio_proc); 3541 } else if (sigio->sio_pgid < 0) { 3542 struct proc *p; 3543 3544 PGRP_LOCK(sigio->sio_pgrp); 3545 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3546 PROC_LOCK(p); 3547 if (p->p_state == PRS_NORMAL && 3548 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3549 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3550 kern_psignal(p, sig); 3551 PROC_UNLOCK(p); 3552 } 3553 PGRP_UNLOCK(sigio->sio_pgrp); 3554 } 3555 SIGIO_UNLOCK(); 3556 } 3557 3558 static int 3559 filt_sigattach(struct knote *kn) 3560 { 3561 struct proc *p = curproc; 3562 3563 kn->kn_ptr.p_proc = p; 3564 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3565 3566 knlist_add(p->p_klist, kn, 0); 3567 3568 return (0); 3569 } 3570 3571 static void 3572 filt_sigdetach(struct knote *kn) 3573 { 3574 struct proc *p = kn->kn_ptr.p_proc; 3575 3576 knlist_remove(p->p_klist, kn, 0); 3577 } 3578 3579 /* 3580 * signal knotes are shared with proc knotes, so we apply a mask to 3581 * the hint in order to differentiate them from process hints. This 3582 * could be avoided by using a signal-specific knote list, but probably 3583 * isn't worth the trouble. 3584 */ 3585 static int 3586 filt_signal(struct knote *kn, long hint) 3587 { 3588 3589 if (hint & NOTE_SIGNAL) { 3590 hint &= ~NOTE_SIGNAL; 3591 3592 if (kn->kn_id == hint) 3593 kn->kn_data++; 3594 } 3595 return (kn->kn_data != 0); 3596 } 3597 3598 struct sigacts * 3599 sigacts_alloc(void) 3600 { 3601 struct sigacts *ps; 3602 3603 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3604 refcount_init(&ps->ps_refcnt, 1); 3605 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3606 return (ps); 3607 } 3608 3609 void 3610 sigacts_free(struct sigacts *ps) 3611 { 3612 3613 if (refcount_release(&ps->ps_refcnt) == 0) 3614 return; 3615 mtx_destroy(&ps->ps_mtx); 3616 free(ps, M_SUBPROC); 3617 } 3618 3619 struct sigacts * 3620 sigacts_hold(struct sigacts *ps) 3621 { 3622 3623 refcount_acquire(&ps->ps_refcnt); 3624 return (ps); 3625 } 3626 3627 void 3628 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3629 { 3630 3631 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3632 mtx_lock(&src->ps_mtx); 3633 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3634 mtx_unlock(&src->ps_mtx); 3635 } 3636 3637 int 3638 sigacts_shared(struct sigacts *ps) 3639 { 3640 3641 return (ps->ps_refcnt > 1); 3642 } 3643