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