1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 #include "opt_core.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/signalvar.h> 47 #include <sys/vnode.h> 48 #include <sys/acct.h> 49 #include <sys/capability.h> 50 #include <sys/condvar.h> 51 #include <sys/event.h> 52 #include <sys/fcntl.h> 53 #include <sys/imgact.h> 54 #include <sys/kernel.h> 55 #include <sys/ktr.h> 56 #include <sys/ktrace.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mutex.h> 60 #include <sys/namei.h> 61 #include <sys/proc.h> 62 #include <sys/procdesc.h> 63 #include <sys/posix4.h> 64 #include <sys/pioctl.h> 65 #include <sys/racct.h> 66 #include <sys/resourcevar.h> 67 #include <sys/sdt.h> 68 #include <sys/sbuf.h> 69 #include <sys/sleepqueue.h> 70 #include <sys/smp.h> 71 #include <sys/stat.h> 72 #include <sys/sx.h> 73 #include <sys/syscallsubr.h> 74 #include <sys/sysctl.h> 75 #include <sys/sysent.h> 76 #include <sys/syslog.h> 77 #include <sys/sysproto.h> 78 #include <sys/timers.h> 79 #include <sys/unistd.h> 80 #include <sys/wait.h> 81 #include <vm/vm.h> 82 #include <vm/vm_extern.h> 83 #include <vm/uma.h> 84 85 #include <sys/jail.h> 86 87 #include <machine/cpu.h> 88 89 #include <security/audit/audit.h> 90 91 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 92 93 SDT_PROVIDER_DECLARE(proc); 94 SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *", 95 "struct proc *", "int"); 96 SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int", 97 "ksiginfo_t *"); 98 SDT_PROBE_DEFINE3(proc, kernel, , signal__discard, 99 "struct thread *", "struct proc *", "int"); 100 101 static int coredump(struct thread *); 102 static int killpg1(struct thread *td, int sig, int pgid, int all, 103 ksiginfo_t *ksi); 104 static int issignal(struct thread *td); 105 static int sigprop(int sig); 106 static void tdsigwakeup(struct thread *, int, sig_t, int); 107 static void sig_suspend_threads(struct thread *, struct proc *, int); 108 static int filt_sigattach(struct knote *kn); 109 static void filt_sigdetach(struct knote *kn); 110 static int filt_signal(struct knote *kn, long hint); 111 static struct thread *sigtd(struct proc *p, int sig, int prop); 112 static void sigqueue_start(void); 113 114 static uma_zone_t ksiginfo_zone = NULL; 115 struct filterops sig_filtops = { 116 .f_isfd = 0, 117 .f_attach = filt_sigattach, 118 .f_detach = filt_sigdetach, 119 .f_event = filt_signal, 120 }; 121 122 static int kern_logsigexit = 1; 123 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 124 &kern_logsigexit, 0, 125 "Log processes quitting on abnormal signals to syslog(3)"); 126 127 static int kern_forcesigexit = 1; 128 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 129 &kern_forcesigexit, 0, "Force trap signal to be handled"); 130 131 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 132 "POSIX real time signal"); 133 134 static int max_pending_per_proc = 128; 135 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 136 &max_pending_per_proc, 0, "Max pending signals per proc"); 137 138 static int preallocate_siginfo = 1024; 139 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 141 &preallocate_siginfo, 0, "Preallocated signal memory size"); 142 143 static int signal_overflow = 0; 144 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 145 &signal_overflow, 0, "Number of signals overflew"); 146 147 static int signal_alloc_fail = 0; 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 149 &signal_alloc_fail, 0, "signals failed to be allocated"); 150 151 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 152 153 /* 154 * Policy -- Can ucred cr1 send SIGIO to process cr2? 155 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 156 * in the right situations. 157 */ 158 #define CANSIGIO(cr1, cr2) \ 159 ((cr1)->cr_uid == 0 || \ 160 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 161 (cr1)->cr_uid == (cr2)->cr_ruid || \ 162 (cr1)->cr_ruid == (cr2)->cr_uid || \ 163 (cr1)->cr_uid == (cr2)->cr_uid) 164 165 static int sugid_coredump; 166 TUNABLE_INT("kern.sugid_coredump", &sugid_coredump); 167 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 168 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 169 170 static int capmode_coredump; 171 TUNABLE_INT("kern.capmode_coredump", &capmode_coredump); 172 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW, 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 /* 184 * Signal properties and actions. 185 * The array below categorizes the signals and their default actions 186 * according to the following properties: 187 */ 188 #define SA_KILL 0x01 /* terminates process by default */ 189 #define SA_CORE 0x02 /* ditto and coredumps */ 190 #define SA_STOP 0x04 /* suspend process */ 191 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 192 #define SA_IGNORE 0x10 /* ignore by default */ 193 #define SA_CONT 0x20 /* continue if suspended */ 194 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 195 196 static int sigproptbl[NSIG] = { 197 SA_KILL, /* SIGHUP */ 198 SA_KILL, /* SIGINT */ 199 SA_KILL|SA_CORE, /* SIGQUIT */ 200 SA_KILL|SA_CORE, /* SIGILL */ 201 SA_KILL|SA_CORE, /* SIGTRAP */ 202 SA_KILL|SA_CORE, /* SIGABRT */ 203 SA_KILL|SA_CORE, /* SIGEMT */ 204 SA_KILL|SA_CORE, /* SIGFPE */ 205 SA_KILL, /* SIGKILL */ 206 SA_KILL|SA_CORE, /* SIGBUS */ 207 SA_KILL|SA_CORE, /* SIGSEGV */ 208 SA_KILL|SA_CORE, /* SIGSYS */ 209 SA_KILL, /* SIGPIPE */ 210 SA_KILL, /* SIGALRM */ 211 SA_KILL, /* SIGTERM */ 212 SA_IGNORE, /* SIGURG */ 213 SA_STOP, /* SIGSTOP */ 214 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 215 SA_IGNORE|SA_CONT, /* SIGCONT */ 216 SA_IGNORE, /* SIGCHLD */ 217 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 218 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 219 SA_IGNORE, /* SIGIO */ 220 SA_KILL, /* SIGXCPU */ 221 SA_KILL, /* SIGXFSZ */ 222 SA_KILL, /* SIGVTALRM */ 223 SA_KILL, /* SIGPROF */ 224 SA_IGNORE, /* SIGWINCH */ 225 SA_IGNORE, /* SIGINFO */ 226 SA_KILL, /* SIGUSR1 */ 227 SA_KILL, /* SIGUSR2 */ 228 }; 229 230 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 231 232 static void 233 sigqueue_start(void) 234 { 235 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 236 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 237 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 238 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 239 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 240 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 241 } 242 243 ksiginfo_t * 244 ksiginfo_alloc(int wait) 245 { 246 int flags; 247 248 flags = M_ZERO; 249 if (! wait) 250 flags |= M_NOWAIT; 251 if (ksiginfo_zone != NULL) 252 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 253 return (NULL); 254 } 255 256 void 257 ksiginfo_free(ksiginfo_t *ksi) 258 { 259 uma_zfree(ksiginfo_zone, ksi); 260 } 261 262 static __inline int 263 ksiginfo_tryfree(ksiginfo_t *ksi) 264 { 265 if (!(ksi->ksi_flags & KSI_EXT)) { 266 uma_zfree(ksiginfo_zone, ksi); 267 return (1); 268 } 269 return (0); 270 } 271 272 void 273 sigqueue_init(sigqueue_t *list, struct proc *p) 274 { 275 SIGEMPTYSET(list->sq_signals); 276 SIGEMPTYSET(list->sq_kill); 277 TAILQ_INIT(&list->sq_list); 278 list->sq_proc = p; 279 list->sq_flags = SQ_INIT; 280 } 281 282 /* 283 * Get a signal's ksiginfo. 284 * Return: 285 * 0 - signal not found 286 * others - signal number 287 */ 288 static int 289 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 290 { 291 struct proc *p = sq->sq_proc; 292 struct ksiginfo *ksi, *next; 293 int count = 0; 294 295 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 296 297 if (!SIGISMEMBER(sq->sq_signals, signo)) 298 return (0); 299 300 if (SIGISMEMBER(sq->sq_kill, signo)) { 301 count++; 302 SIGDELSET(sq->sq_kill, signo); 303 } 304 305 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 306 if (ksi->ksi_signo == signo) { 307 if (count == 0) { 308 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 309 ksi->ksi_sigq = NULL; 310 ksiginfo_copy(ksi, si); 311 if (ksiginfo_tryfree(ksi) && p != NULL) 312 p->p_pendingcnt--; 313 } 314 if (++count > 1) 315 break; 316 } 317 } 318 319 if (count <= 1) 320 SIGDELSET(sq->sq_signals, signo); 321 si->ksi_signo = signo; 322 return (signo); 323 } 324 325 void 326 sigqueue_take(ksiginfo_t *ksi) 327 { 328 struct ksiginfo *kp; 329 struct proc *p; 330 sigqueue_t *sq; 331 332 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 333 return; 334 335 p = sq->sq_proc; 336 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 337 ksi->ksi_sigq = NULL; 338 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 339 p->p_pendingcnt--; 340 341 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 342 kp = TAILQ_NEXT(kp, ksi_link)) { 343 if (kp->ksi_signo == ksi->ksi_signo) 344 break; 345 } 346 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 347 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 348 } 349 350 static int 351 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 352 { 353 struct proc *p = sq->sq_proc; 354 struct ksiginfo *ksi; 355 int ret = 0; 356 357 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 358 359 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 360 SIGADDSET(sq->sq_kill, signo); 361 goto out_set_bit; 362 } 363 364 /* directly insert the ksi, don't copy it */ 365 if (si->ksi_flags & KSI_INS) { 366 if (si->ksi_flags & KSI_HEAD) 367 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 368 else 369 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 370 si->ksi_sigq = sq; 371 goto out_set_bit; 372 } 373 374 if (__predict_false(ksiginfo_zone == NULL)) { 375 SIGADDSET(sq->sq_kill, signo); 376 goto out_set_bit; 377 } 378 379 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 380 signal_overflow++; 381 ret = EAGAIN; 382 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 383 signal_alloc_fail++; 384 ret = EAGAIN; 385 } else { 386 if (p != NULL) 387 p->p_pendingcnt++; 388 ksiginfo_copy(si, ksi); 389 ksi->ksi_signo = signo; 390 if (si->ksi_flags & KSI_HEAD) 391 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 392 else 393 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 394 ksi->ksi_sigq = sq; 395 } 396 397 if ((si->ksi_flags & KSI_TRAP) != 0 || 398 (si->ksi_flags & KSI_SIGQ) == 0) { 399 if (ret != 0) 400 SIGADDSET(sq->sq_kill, signo); 401 ret = 0; 402 goto out_set_bit; 403 } 404 405 if (ret != 0) 406 return (ret); 407 408 out_set_bit: 409 SIGADDSET(sq->sq_signals, signo); 410 return (ret); 411 } 412 413 void 414 sigqueue_flush(sigqueue_t *sq) 415 { 416 struct proc *p = sq->sq_proc; 417 ksiginfo_t *ksi; 418 419 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 420 421 if (p != NULL) 422 PROC_LOCK_ASSERT(p, MA_OWNED); 423 424 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 425 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 426 ksi->ksi_sigq = NULL; 427 if (ksiginfo_tryfree(ksi) && p != NULL) 428 p->p_pendingcnt--; 429 } 430 431 SIGEMPTYSET(sq->sq_signals); 432 SIGEMPTYSET(sq->sq_kill); 433 } 434 435 static void 436 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 437 { 438 sigset_t tmp; 439 struct proc *p1, *p2; 440 ksiginfo_t *ksi, *next; 441 442 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 443 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 444 p1 = src->sq_proc; 445 p2 = dst->sq_proc; 446 /* Move siginfo to target list */ 447 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 448 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 449 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 450 if (p1 != NULL) 451 p1->p_pendingcnt--; 452 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 453 ksi->ksi_sigq = dst; 454 if (p2 != NULL) 455 p2->p_pendingcnt++; 456 } 457 } 458 459 /* Move pending bits to target list */ 460 tmp = src->sq_kill; 461 SIGSETAND(tmp, *set); 462 SIGSETOR(dst->sq_kill, tmp); 463 SIGSETNAND(src->sq_kill, tmp); 464 465 tmp = src->sq_signals; 466 SIGSETAND(tmp, *set); 467 SIGSETOR(dst->sq_signals, tmp); 468 SIGSETNAND(src->sq_signals, tmp); 469 } 470 471 #if 0 472 static void 473 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 474 { 475 sigset_t set; 476 477 SIGEMPTYSET(set); 478 SIGADDSET(set, signo); 479 sigqueue_move_set(src, dst, &set); 480 } 481 #endif 482 483 static void 484 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 485 { 486 struct proc *p = sq->sq_proc; 487 ksiginfo_t *ksi, *next; 488 489 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 490 491 /* Remove siginfo queue */ 492 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 493 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 494 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 495 ksi->ksi_sigq = NULL; 496 if (ksiginfo_tryfree(ksi) && p != NULL) 497 p->p_pendingcnt--; 498 } 499 } 500 SIGSETNAND(sq->sq_kill, *set); 501 SIGSETNAND(sq->sq_signals, *set); 502 } 503 504 void 505 sigqueue_delete(sigqueue_t *sq, int signo) 506 { 507 sigset_t set; 508 509 SIGEMPTYSET(set); 510 SIGADDSET(set, signo); 511 sigqueue_delete_set(sq, &set); 512 } 513 514 /* Remove a set of signals for a process */ 515 static void 516 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 517 { 518 sigqueue_t worklist; 519 struct thread *td0; 520 521 PROC_LOCK_ASSERT(p, MA_OWNED); 522 523 sigqueue_init(&worklist, NULL); 524 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 525 526 FOREACH_THREAD_IN_PROC(p, td0) 527 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 528 529 sigqueue_flush(&worklist); 530 } 531 532 void 533 sigqueue_delete_proc(struct proc *p, int signo) 534 { 535 sigset_t set; 536 537 SIGEMPTYSET(set); 538 SIGADDSET(set, signo); 539 sigqueue_delete_set_proc(p, &set); 540 } 541 542 static void 543 sigqueue_delete_stopmask_proc(struct proc *p) 544 { 545 sigset_t set; 546 547 SIGEMPTYSET(set); 548 SIGADDSET(set, SIGSTOP); 549 SIGADDSET(set, SIGTSTP); 550 SIGADDSET(set, SIGTTIN); 551 SIGADDSET(set, SIGTTOU); 552 sigqueue_delete_set_proc(p, &set); 553 } 554 555 /* 556 * Determine signal that should be delivered to thread td, the current 557 * thread, 0 if none. If there is a pending stop signal with default 558 * action, the process stops in issignal(). 559 */ 560 int 561 cursig(struct thread *td) 562 { 563 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 564 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 565 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 566 return (SIGPENDING(td) ? issignal(td) : 0); 567 } 568 569 /* 570 * Arrange for ast() to handle unmasked pending signals on return to user 571 * mode. This must be called whenever a signal is added to td_sigqueue or 572 * unmasked in td_sigmask. 573 */ 574 void 575 signotify(struct thread *td) 576 { 577 struct proc *p; 578 579 p = td->td_proc; 580 581 PROC_LOCK_ASSERT(p, MA_OWNED); 582 583 if (SIGPENDING(td)) { 584 thread_lock(td); 585 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 586 thread_unlock(td); 587 } 588 } 589 590 int 591 sigonstack(size_t sp) 592 { 593 struct thread *td = curthread; 594 595 return ((td->td_pflags & TDP_ALTSTACK) ? 596 #if defined(COMPAT_43) 597 ((td->td_sigstk.ss_size == 0) ? 598 (td->td_sigstk.ss_flags & SS_ONSTACK) : 599 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 600 #else 601 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 602 #endif 603 : 0); 604 } 605 606 static __inline int 607 sigprop(int sig) 608 { 609 610 if (sig > 0 && sig < NSIG) 611 return (sigproptbl[_SIG_IDX(sig)]); 612 return (0); 613 } 614 615 int 616 sig_ffs(sigset_t *set) 617 { 618 int i; 619 620 for (i = 0; i < _SIG_WORDS; i++) 621 if (set->__bits[i]) 622 return (ffs(set->__bits[i]) + (i * 32)); 623 return (0); 624 } 625 626 /* 627 * kern_sigaction 628 * sigaction 629 * freebsd4_sigaction 630 * osigaction 631 */ 632 int 633 kern_sigaction(td, sig, act, oact, flags) 634 struct thread *td; 635 register int sig; 636 struct sigaction *act, *oact; 637 int flags; 638 { 639 struct sigacts *ps; 640 struct proc *p = td->td_proc; 641 642 if (!_SIG_VALID(sig)) 643 return (EINVAL); 644 645 PROC_LOCK(p); 646 ps = p->p_sigacts; 647 mtx_lock(&ps->ps_mtx); 648 if (oact) { 649 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 650 oact->sa_flags = 0; 651 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 652 oact->sa_flags |= SA_ONSTACK; 653 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 654 oact->sa_flags |= SA_RESTART; 655 if (SIGISMEMBER(ps->ps_sigreset, sig)) 656 oact->sa_flags |= SA_RESETHAND; 657 if (SIGISMEMBER(ps->ps_signodefer, sig)) 658 oact->sa_flags |= SA_NODEFER; 659 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 660 oact->sa_flags |= SA_SIGINFO; 661 oact->sa_sigaction = 662 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 663 } else 664 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 665 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 666 oact->sa_flags |= SA_NOCLDSTOP; 667 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 668 oact->sa_flags |= SA_NOCLDWAIT; 669 } 670 if (act) { 671 if ((sig == SIGKILL || sig == SIGSTOP) && 672 act->sa_handler != SIG_DFL) { 673 mtx_unlock(&ps->ps_mtx); 674 PROC_UNLOCK(p); 675 return (EINVAL); 676 } 677 678 /* 679 * Change setting atomically. 680 */ 681 682 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 683 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 684 if (act->sa_flags & SA_SIGINFO) { 685 ps->ps_sigact[_SIG_IDX(sig)] = 686 (__sighandler_t *)act->sa_sigaction; 687 SIGADDSET(ps->ps_siginfo, sig); 688 } else { 689 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 690 SIGDELSET(ps->ps_siginfo, sig); 691 } 692 if (!(act->sa_flags & SA_RESTART)) 693 SIGADDSET(ps->ps_sigintr, sig); 694 else 695 SIGDELSET(ps->ps_sigintr, sig); 696 if (act->sa_flags & SA_ONSTACK) 697 SIGADDSET(ps->ps_sigonstack, sig); 698 else 699 SIGDELSET(ps->ps_sigonstack, sig); 700 if (act->sa_flags & SA_RESETHAND) 701 SIGADDSET(ps->ps_sigreset, sig); 702 else 703 SIGDELSET(ps->ps_sigreset, sig); 704 if (act->sa_flags & SA_NODEFER) 705 SIGADDSET(ps->ps_signodefer, sig); 706 else 707 SIGDELSET(ps->ps_signodefer, sig); 708 if (sig == SIGCHLD) { 709 if (act->sa_flags & SA_NOCLDSTOP) 710 ps->ps_flag |= PS_NOCLDSTOP; 711 else 712 ps->ps_flag &= ~PS_NOCLDSTOP; 713 if (act->sa_flags & SA_NOCLDWAIT) { 714 /* 715 * Paranoia: since SA_NOCLDWAIT is implemented 716 * by reparenting the dying child to PID 1 (and 717 * trust it to reap the zombie), PID 1 itself 718 * is forbidden to set SA_NOCLDWAIT. 719 */ 720 if (p->p_pid == 1) 721 ps->ps_flag &= ~PS_NOCLDWAIT; 722 else 723 ps->ps_flag |= PS_NOCLDWAIT; 724 } else 725 ps->ps_flag &= ~PS_NOCLDWAIT; 726 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 727 ps->ps_flag |= PS_CLDSIGIGN; 728 else 729 ps->ps_flag &= ~PS_CLDSIGIGN; 730 } 731 /* 732 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 733 * and for signals set to SIG_DFL where the default is to 734 * ignore. However, don't put SIGCONT in ps_sigignore, as we 735 * have to restart the process. 736 */ 737 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 738 (sigprop(sig) & SA_IGNORE && 739 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 740 /* never to be seen again */ 741 sigqueue_delete_proc(p, sig); 742 if (sig != SIGCONT) 743 /* easier in psignal */ 744 SIGADDSET(ps->ps_sigignore, sig); 745 SIGDELSET(ps->ps_sigcatch, sig); 746 } else { 747 SIGDELSET(ps->ps_sigignore, sig); 748 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 749 SIGDELSET(ps->ps_sigcatch, sig); 750 else 751 SIGADDSET(ps->ps_sigcatch, sig); 752 } 753 #ifdef COMPAT_FREEBSD4 754 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 755 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 756 (flags & KSA_FREEBSD4) == 0) 757 SIGDELSET(ps->ps_freebsd4, sig); 758 else 759 SIGADDSET(ps->ps_freebsd4, sig); 760 #endif 761 #ifdef COMPAT_43 762 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 763 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 764 (flags & KSA_OSIGSET) == 0) 765 SIGDELSET(ps->ps_osigset, sig); 766 else 767 SIGADDSET(ps->ps_osigset, sig); 768 #endif 769 } 770 mtx_unlock(&ps->ps_mtx); 771 PROC_UNLOCK(p); 772 return (0); 773 } 774 775 #ifndef _SYS_SYSPROTO_H_ 776 struct sigaction_args { 777 int sig; 778 struct sigaction *act; 779 struct sigaction *oact; 780 }; 781 #endif 782 int 783 sys_sigaction(td, uap) 784 struct thread *td; 785 register struct sigaction_args *uap; 786 { 787 struct sigaction act, oact; 788 register struct sigaction *actp, *oactp; 789 int error; 790 791 actp = (uap->act != NULL) ? &act : NULL; 792 oactp = (uap->oact != NULL) ? &oact : NULL; 793 if (actp) { 794 error = copyin(uap->act, actp, sizeof(act)); 795 if (error) 796 return (error); 797 } 798 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 799 if (oactp && !error) 800 error = copyout(oactp, uap->oact, sizeof(oact)); 801 return (error); 802 } 803 804 #ifdef COMPAT_FREEBSD4 805 #ifndef _SYS_SYSPROTO_H_ 806 struct freebsd4_sigaction_args { 807 int sig; 808 struct sigaction *act; 809 struct sigaction *oact; 810 }; 811 #endif 812 int 813 freebsd4_sigaction(td, uap) 814 struct thread *td; 815 register struct freebsd4_sigaction_args *uap; 816 { 817 struct sigaction act, oact; 818 register struct sigaction *actp, *oactp; 819 int error; 820 821 822 actp = (uap->act != NULL) ? &act : NULL; 823 oactp = (uap->oact != NULL) ? &oact : NULL; 824 if (actp) { 825 error = copyin(uap->act, actp, sizeof(act)); 826 if (error) 827 return (error); 828 } 829 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 830 if (oactp && !error) 831 error = copyout(oactp, uap->oact, sizeof(oact)); 832 return (error); 833 } 834 #endif /* COMAPT_FREEBSD4 */ 835 836 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 837 #ifndef _SYS_SYSPROTO_H_ 838 struct osigaction_args { 839 int signum; 840 struct osigaction *nsa; 841 struct osigaction *osa; 842 }; 843 #endif 844 int 845 osigaction(td, uap) 846 struct thread *td; 847 register struct osigaction_args *uap; 848 { 849 struct osigaction sa; 850 struct sigaction nsa, osa; 851 register struct sigaction *nsap, *osap; 852 int error; 853 854 if (uap->signum <= 0 || uap->signum >= ONSIG) 855 return (EINVAL); 856 857 nsap = (uap->nsa != NULL) ? &nsa : NULL; 858 osap = (uap->osa != NULL) ? &osa : NULL; 859 860 if (nsap) { 861 error = copyin(uap->nsa, &sa, sizeof(sa)); 862 if (error) 863 return (error); 864 nsap->sa_handler = sa.sa_handler; 865 nsap->sa_flags = sa.sa_flags; 866 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 867 } 868 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 869 if (osap && !error) { 870 sa.sa_handler = osap->sa_handler; 871 sa.sa_flags = osap->sa_flags; 872 SIG2OSIG(osap->sa_mask, sa.sa_mask); 873 error = copyout(&sa, uap->osa, sizeof(sa)); 874 } 875 return (error); 876 } 877 878 #if !defined(__i386__) 879 /* Avoid replicating the same stub everywhere */ 880 int 881 osigreturn(td, uap) 882 struct thread *td; 883 struct osigreturn_args *uap; 884 { 885 886 return (nosys(td, (struct nosys_args *)uap)); 887 } 888 #endif 889 #endif /* COMPAT_43 */ 890 891 /* 892 * Initialize signal state for process 0; 893 * set to ignore signals that are ignored by default. 894 */ 895 void 896 siginit(p) 897 struct proc *p; 898 { 899 register int i; 900 struct sigacts *ps; 901 902 PROC_LOCK(p); 903 ps = p->p_sigacts; 904 mtx_lock(&ps->ps_mtx); 905 for (i = 1; i <= NSIG; i++) 906 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 907 SIGADDSET(ps->ps_sigignore, i); 908 mtx_unlock(&ps->ps_mtx); 909 PROC_UNLOCK(p); 910 } 911 912 /* 913 * Reset signals for an exec of the specified process. 914 */ 915 void 916 execsigs(struct proc *p) 917 { 918 struct sigacts *ps; 919 int sig; 920 struct thread *td; 921 922 /* 923 * Reset caught signals. Held signals remain held 924 * through td_sigmask (unless they were caught, 925 * and are now ignored by default). 926 */ 927 PROC_LOCK_ASSERT(p, MA_OWNED); 928 td = FIRST_THREAD_IN_PROC(p); 929 ps = p->p_sigacts; 930 mtx_lock(&ps->ps_mtx); 931 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 932 sig = sig_ffs(&ps->ps_sigcatch); 933 SIGDELSET(ps->ps_sigcatch, sig); 934 if (sigprop(sig) & SA_IGNORE) { 935 if (sig != SIGCONT) 936 SIGADDSET(ps->ps_sigignore, sig); 937 sigqueue_delete_proc(p, sig); 938 } 939 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 940 } 941 /* 942 * Reset stack state to the user stack. 943 * Clear set of signals caught on the signal stack. 944 */ 945 td->td_sigstk.ss_flags = SS_DISABLE; 946 td->td_sigstk.ss_size = 0; 947 td->td_sigstk.ss_sp = 0; 948 td->td_pflags &= ~TDP_ALTSTACK; 949 /* 950 * Reset no zombies if child dies flag as Solaris does. 951 */ 952 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 953 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 954 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 955 mtx_unlock(&ps->ps_mtx); 956 } 957 958 /* 959 * kern_sigprocmask() 960 * 961 * Manipulate signal mask. 962 */ 963 int 964 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 965 int flags) 966 { 967 sigset_t new_block, oset1; 968 struct proc *p; 969 int error; 970 971 p = td->td_proc; 972 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 973 PROC_LOCK(p); 974 if (oset != NULL) 975 *oset = td->td_sigmask; 976 977 error = 0; 978 if (set != NULL) { 979 switch (how) { 980 case SIG_BLOCK: 981 SIG_CANTMASK(*set); 982 oset1 = td->td_sigmask; 983 SIGSETOR(td->td_sigmask, *set); 984 new_block = td->td_sigmask; 985 SIGSETNAND(new_block, oset1); 986 break; 987 case SIG_UNBLOCK: 988 SIGSETNAND(td->td_sigmask, *set); 989 signotify(td); 990 goto out; 991 case SIG_SETMASK: 992 SIG_CANTMASK(*set); 993 oset1 = td->td_sigmask; 994 if (flags & SIGPROCMASK_OLD) 995 SIGSETLO(td->td_sigmask, *set); 996 else 997 td->td_sigmask = *set; 998 new_block = td->td_sigmask; 999 SIGSETNAND(new_block, oset1); 1000 signotify(td); 1001 break; 1002 default: 1003 error = EINVAL; 1004 goto out; 1005 } 1006 1007 /* 1008 * The new_block set contains signals that were not previously 1009 * blocked, but are blocked now. 1010 * 1011 * In case we block any signal that was not previously blocked 1012 * for td, and process has the signal pending, try to schedule 1013 * signal delivery to some thread that does not block the 1014 * signal, possibly waking it up. 1015 */ 1016 if (p->p_numthreads != 1) 1017 reschedule_signals(p, new_block, flags); 1018 } 1019 1020 out: 1021 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1022 PROC_UNLOCK(p); 1023 return (error); 1024 } 1025 1026 #ifndef _SYS_SYSPROTO_H_ 1027 struct sigprocmask_args { 1028 int how; 1029 const sigset_t *set; 1030 sigset_t *oset; 1031 }; 1032 #endif 1033 int 1034 sys_sigprocmask(td, uap) 1035 register struct thread *td; 1036 struct sigprocmask_args *uap; 1037 { 1038 sigset_t set, oset; 1039 sigset_t *setp, *osetp; 1040 int error; 1041 1042 setp = (uap->set != NULL) ? &set : NULL; 1043 osetp = (uap->oset != NULL) ? &oset : NULL; 1044 if (setp) { 1045 error = copyin(uap->set, setp, sizeof(set)); 1046 if (error) 1047 return (error); 1048 } 1049 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1050 if (osetp && !error) { 1051 error = copyout(osetp, uap->oset, sizeof(oset)); 1052 } 1053 return (error); 1054 } 1055 1056 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1057 #ifndef _SYS_SYSPROTO_H_ 1058 struct osigprocmask_args { 1059 int how; 1060 osigset_t mask; 1061 }; 1062 #endif 1063 int 1064 osigprocmask(td, uap) 1065 register struct thread *td; 1066 struct osigprocmask_args *uap; 1067 { 1068 sigset_t set, oset; 1069 int error; 1070 1071 OSIG2SIG(uap->mask, set); 1072 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1073 SIG2OSIG(oset, td->td_retval[0]); 1074 return (error); 1075 } 1076 #endif /* COMPAT_43 */ 1077 1078 int 1079 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1080 { 1081 ksiginfo_t ksi; 1082 sigset_t set; 1083 int error; 1084 1085 error = copyin(uap->set, &set, sizeof(set)); 1086 if (error) { 1087 td->td_retval[0] = error; 1088 return (0); 1089 } 1090 1091 error = kern_sigtimedwait(td, set, &ksi, NULL); 1092 if (error) { 1093 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1094 error = ERESTART; 1095 if (error == ERESTART) 1096 return (error); 1097 td->td_retval[0] = error; 1098 return (0); 1099 } 1100 1101 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1102 td->td_retval[0] = error; 1103 return (0); 1104 } 1105 1106 int 1107 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1108 { 1109 struct timespec ts; 1110 struct timespec *timeout; 1111 sigset_t set; 1112 ksiginfo_t ksi; 1113 int error; 1114 1115 if (uap->timeout) { 1116 error = copyin(uap->timeout, &ts, sizeof(ts)); 1117 if (error) 1118 return (error); 1119 1120 timeout = &ts; 1121 } else 1122 timeout = NULL; 1123 1124 error = copyin(uap->set, &set, sizeof(set)); 1125 if (error) 1126 return (error); 1127 1128 error = kern_sigtimedwait(td, set, &ksi, timeout); 1129 if (error) 1130 return (error); 1131 1132 if (uap->info) 1133 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1134 1135 if (error == 0) 1136 td->td_retval[0] = ksi.ksi_signo; 1137 return (error); 1138 } 1139 1140 int 1141 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1142 { 1143 ksiginfo_t ksi; 1144 sigset_t set; 1145 int error; 1146 1147 error = copyin(uap->set, &set, sizeof(set)); 1148 if (error) 1149 return (error); 1150 1151 error = kern_sigtimedwait(td, set, &ksi, NULL); 1152 if (error) 1153 return (error); 1154 1155 if (uap->info) 1156 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1157 1158 if (error == 0) 1159 td->td_retval[0] = ksi.ksi_signo; 1160 return (error); 1161 } 1162 1163 int 1164 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1165 struct timespec *timeout) 1166 { 1167 struct sigacts *ps; 1168 sigset_t saved_mask, new_block; 1169 struct proc *p; 1170 int error, sig, timo, timevalid = 0; 1171 struct timespec rts, ets, ts; 1172 struct timeval tv; 1173 1174 p = td->td_proc; 1175 error = 0; 1176 ets.tv_sec = 0; 1177 ets.tv_nsec = 0; 1178 1179 if (timeout != NULL) { 1180 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1181 timevalid = 1; 1182 getnanouptime(&rts); 1183 ets = rts; 1184 timespecadd(&ets, timeout); 1185 } 1186 } 1187 ksiginfo_init(ksi); 1188 /* Some signals can not be waited for. */ 1189 SIG_CANTMASK(waitset); 1190 ps = p->p_sigacts; 1191 PROC_LOCK(p); 1192 saved_mask = td->td_sigmask; 1193 SIGSETNAND(td->td_sigmask, waitset); 1194 for (;;) { 1195 mtx_lock(&ps->ps_mtx); 1196 sig = cursig(td); 1197 mtx_unlock(&ps->ps_mtx); 1198 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1199 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1200 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1201 error = 0; 1202 break; 1203 } 1204 } 1205 1206 if (error != 0) 1207 break; 1208 1209 /* 1210 * POSIX says this must be checked after looking for pending 1211 * signals. 1212 */ 1213 if (timeout != NULL) { 1214 if (!timevalid) { 1215 error = EINVAL; 1216 break; 1217 } 1218 getnanouptime(&rts); 1219 if (timespeccmp(&rts, &ets, >=)) { 1220 error = EAGAIN; 1221 break; 1222 } 1223 ts = ets; 1224 timespecsub(&ts, &rts); 1225 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1226 timo = tvtohz(&tv); 1227 } else { 1228 timo = 0; 1229 } 1230 1231 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1232 1233 if (timeout != NULL) { 1234 if (error == ERESTART) { 1235 /* Timeout can not be restarted. */ 1236 error = EINTR; 1237 } else if (error == EAGAIN) { 1238 /* We will calculate timeout by ourself. */ 1239 error = 0; 1240 } 1241 } 1242 } 1243 1244 new_block = saved_mask; 1245 SIGSETNAND(new_block, td->td_sigmask); 1246 td->td_sigmask = saved_mask; 1247 /* 1248 * Fewer signals can be delivered to us, reschedule signal 1249 * notification. 1250 */ 1251 if (p->p_numthreads != 1) 1252 reschedule_signals(p, new_block, 0); 1253 1254 if (error == 0) { 1255 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0); 1256 1257 if (ksi->ksi_code == SI_TIMER) 1258 itimer_accept(p, ksi->ksi_timerid, ksi); 1259 1260 #ifdef KTRACE 1261 if (KTRPOINT(td, KTR_PSIG)) { 1262 sig_t action; 1263 1264 mtx_lock(&ps->ps_mtx); 1265 action = ps->ps_sigact[_SIG_IDX(sig)]; 1266 mtx_unlock(&ps->ps_mtx); 1267 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1268 } 1269 #endif 1270 if (sig == SIGKILL) 1271 sigexit(td, sig); 1272 } 1273 PROC_UNLOCK(p); 1274 return (error); 1275 } 1276 1277 #ifndef _SYS_SYSPROTO_H_ 1278 struct sigpending_args { 1279 sigset_t *set; 1280 }; 1281 #endif 1282 int 1283 sys_sigpending(td, uap) 1284 struct thread *td; 1285 struct sigpending_args *uap; 1286 { 1287 struct proc *p = td->td_proc; 1288 sigset_t pending; 1289 1290 PROC_LOCK(p); 1291 pending = p->p_sigqueue.sq_signals; 1292 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1293 PROC_UNLOCK(p); 1294 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1295 } 1296 1297 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1298 #ifndef _SYS_SYSPROTO_H_ 1299 struct osigpending_args { 1300 int dummy; 1301 }; 1302 #endif 1303 int 1304 osigpending(td, uap) 1305 struct thread *td; 1306 struct osigpending_args *uap; 1307 { 1308 struct proc *p = td->td_proc; 1309 sigset_t pending; 1310 1311 PROC_LOCK(p); 1312 pending = p->p_sigqueue.sq_signals; 1313 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1314 PROC_UNLOCK(p); 1315 SIG2OSIG(pending, td->td_retval[0]); 1316 return (0); 1317 } 1318 #endif /* COMPAT_43 */ 1319 1320 #if defined(COMPAT_43) 1321 /* 1322 * Generalized interface signal handler, 4.3-compatible. 1323 */ 1324 #ifndef _SYS_SYSPROTO_H_ 1325 struct osigvec_args { 1326 int signum; 1327 struct sigvec *nsv; 1328 struct sigvec *osv; 1329 }; 1330 #endif 1331 /* ARGSUSED */ 1332 int 1333 osigvec(td, uap) 1334 struct thread *td; 1335 register struct osigvec_args *uap; 1336 { 1337 struct sigvec vec; 1338 struct sigaction nsa, osa; 1339 register struct sigaction *nsap, *osap; 1340 int error; 1341 1342 if (uap->signum <= 0 || uap->signum >= ONSIG) 1343 return (EINVAL); 1344 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1345 osap = (uap->osv != NULL) ? &osa : NULL; 1346 if (nsap) { 1347 error = copyin(uap->nsv, &vec, sizeof(vec)); 1348 if (error) 1349 return (error); 1350 nsap->sa_handler = vec.sv_handler; 1351 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1352 nsap->sa_flags = vec.sv_flags; 1353 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1354 } 1355 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1356 if (osap && !error) { 1357 vec.sv_handler = osap->sa_handler; 1358 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1359 vec.sv_flags = osap->sa_flags; 1360 vec.sv_flags &= ~SA_NOCLDWAIT; 1361 vec.sv_flags ^= SA_RESTART; 1362 error = copyout(&vec, uap->osv, sizeof(vec)); 1363 } 1364 return (error); 1365 } 1366 1367 #ifndef _SYS_SYSPROTO_H_ 1368 struct osigblock_args { 1369 int mask; 1370 }; 1371 #endif 1372 int 1373 osigblock(td, uap) 1374 register struct thread *td; 1375 struct osigblock_args *uap; 1376 { 1377 sigset_t set, oset; 1378 1379 OSIG2SIG(uap->mask, set); 1380 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1381 SIG2OSIG(oset, td->td_retval[0]); 1382 return (0); 1383 } 1384 1385 #ifndef _SYS_SYSPROTO_H_ 1386 struct osigsetmask_args { 1387 int mask; 1388 }; 1389 #endif 1390 int 1391 osigsetmask(td, uap) 1392 struct thread *td; 1393 struct osigsetmask_args *uap; 1394 { 1395 sigset_t set, oset; 1396 1397 OSIG2SIG(uap->mask, set); 1398 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1399 SIG2OSIG(oset, td->td_retval[0]); 1400 return (0); 1401 } 1402 #endif /* COMPAT_43 */ 1403 1404 /* 1405 * Suspend calling thread until signal, providing mask to be set in the 1406 * meantime. 1407 */ 1408 #ifndef _SYS_SYSPROTO_H_ 1409 struct sigsuspend_args { 1410 const sigset_t *sigmask; 1411 }; 1412 #endif 1413 /* ARGSUSED */ 1414 int 1415 sys_sigsuspend(td, uap) 1416 struct thread *td; 1417 struct sigsuspend_args *uap; 1418 { 1419 sigset_t mask; 1420 int error; 1421 1422 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1423 if (error) 1424 return (error); 1425 return (kern_sigsuspend(td, mask)); 1426 } 1427 1428 int 1429 kern_sigsuspend(struct thread *td, sigset_t mask) 1430 { 1431 struct proc *p = td->td_proc; 1432 int has_sig, sig; 1433 1434 /* 1435 * When returning from sigsuspend, we want 1436 * the old mask to be restored after the 1437 * signal handler has finished. Thus, we 1438 * save it here and mark the sigacts structure 1439 * to indicate this. 1440 */ 1441 PROC_LOCK(p); 1442 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1443 SIGPROCMASK_PROC_LOCKED); 1444 td->td_pflags |= TDP_OLDMASK; 1445 1446 /* 1447 * Process signals now. Otherwise, we can get spurious wakeup 1448 * due to signal entered process queue, but delivered to other 1449 * thread. But sigsuspend should return only on signal 1450 * delivery. 1451 */ 1452 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1453 for (has_sig = 0; !has_sig;) { 1454 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1455 0) == 0) 1456 /* void */; 1457 thread_suspend_check(0); 1458 mtx_lock(&p->p_sigacts->ps_mtx); 1459 while ((sig = cursig(td)) != 0) 1460 has_sig += postsig(sig); 1461 mtx_unlock(&p->p_sigacts->ps_mtx); 1462 } 1463 PROC_UNLOCK(p); 1464 td->td_errno = EINTR; 1465 td->td_pflags |= TDP_NERRNO; 1466 return (EJUSTRETURN); 1467 } 1468 1469 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1470 /* 1471 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1472 * convention: libc stub passes mask, not pointer, to save a copyin. 1473 */ 1474 #ifndef _SYS_SYSPROTO_H_ 1475 struct osigsuspend_args { 1476 osigset_t mask; 1477 }; 1478 #endif 1479 /* ARGSUSED */ 1480 int 1481 osigsuspend(td, uap) 1482 struct thread *td; 1483 struct osigsuspend_args *uap; 1484 { 1485 sigset_t mask; 1486 1487 OSIG2SIG(uap->mask, mask); 1488 return (kern_sigsuspend(td, mask)); 1489 } 1490 #endif /* COMPAT_43 */ 1491 1492 #if defined(COMPAT_43) 1493 #ifndef _SYS_SYSPROTO_H_ 1494 struct osigstack_args { 1495 struct sigstack *nss; 1496 struct sigstack *oss; 1497 }; 1498 #endif 1499 /* ARGSUSED */ 1500 int 1501 osigstack(td, uap) 1502 struct thread *td; 1503 register struct osigstack_args *uap; 1504 { 1505 struct sigstack nss, oss; 1506 int error = 0; 1507 1508 if (uap->nss != NULL) { 1509 error = copyin(uap->nss, &nss, sizeof(nss)); 1510 if (error) 1511 return (error); 1512 } 1513 oss.ss_sp = td->td_sigstk.ss_sp; 1514 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1515 if (uap->nss != NULL) { 1516 td->td_sigstk.ss_sp = nss.ss_sp; 1517 td->td_sigstk.ss_size = 0; 1518 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1519 td->td_pflags |= TDP_ALTSTACK; 1520 } 1521 if (uap->oss != NULL) 1522 error = copyout(&oss, uap->oss, sizeof(oss)); 1523 1524 return (error); 1525 } 1526 #endif /* COMPAT_43 */ 1527 1528 #ifndef _SYS_SYSPROTO_H_ 1529 struct sigaltstack_args { 1530 stack_t *ss; 1531 stack_t *oss; 1532 }; 1533 #endif 1534 /* ARGSUSED */ 1535 int 1536 sys_sigaltstack(td, uap) 1537 struct thread *td; 1538 register struct sigaltstack_args *uap; 1539 { 1540 stack_t ss, oss; 1541 int error; 1542 1543 if (uap->ss != NULL) { 1544 error = copyin(uap->ss, &ss, sizeof(ss)); 1545 if (error) 1546 return (error); 1547 } 1548 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1549 (uap->oss != NULL) ? &oss : NULL); 1550 if (error) 1551 return (error); 1552 if (uap->oss != NULL) 1553 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1554 return (error); 1555 } 1556 1557 int 1558 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1559 { 1560 struct proc *p = td->td_proc; 1561 int oonstack; 1562 1563 oonstack = sigonstack(cpu_getstack(td)); 1564 1565 if (oss != NULL) { 1566 *oss = td->td_sigstk; 1567 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1568 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1569 } 1570 1571 if (ss != NULL) { 1572 if (oonstack) 1573 return (EPERM); 1574 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1575 return (EINVAL); 1576 if (!(ss->ss_flags & SS_DISABLE)) { 1577 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1578 return (ENOMEM); 1579 1580 td->td_sigstk = *ss; 1581 td->td_pflags |= TDP_ALTSTACK; 1582 } else { 1583 td->td_pflags &= ~TDP_ALTSTACK; 1584 } 1585 } 1586 return (0); 1587 } 1588 1589 /* 1590 * Common code for kill process group/broadcast kill. 1591 * cp is calling process. 1592 */ 1593 static int 1594 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1595 { 1596 struct proc *p; 1597 struct pgrp *pgrp; 1598 int err; 1599 int ret; 1600 1601 ret = ESRCH; 1602 if (all) { 1603 /* 1604 * broadcast 1605 */ 1606 sx_slock(&allproc_lock); 1607 FOREACH_PROC_IN_SYSTEM(p) { 1608 PROC_LOCK(p); 1609 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1610 p == td->td_proc || p->p_state == PRS_NEW) { 1611 PROC_UNLOCK(p); 1612 continue; 1613 } 1614 err = p_cansignal(td, p, sig); 1615 if (err == 0) { 1616 if (sig) 1617 pksignal(p, sig, ksi); 1618 ret = err; 1619 } 1620 else if (ret == ESRCH) 1621 ret = err; 1622 PROC_UNLOCK(p); 1623 } 1624 sx_sunlock(&allproc_lock); 1625 } else { 1626 sx_slock(&proctree_lock); 1627 if (pgid == 0) { 1628 /* 1629 * zero pgid means send to my process group. 1630 */ 1631 pgrp = td->td_proc->p_pgrp; 1632 PGRP_LOCK(pgrp); 1633 } else { 1634 pgrp = pgfind(pgid); 1635 if (pgrp == NULL) { 1636 sx_sunlock(&proctree_lock); 1637 return (ESRCH); 1638 } 1639 } 1640 sx_sunlock(&proctree_lock); 1641 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1642 PROC_LOCK(p); 1643 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1644 p->p_state == PRS_NEW) { 1645 PROC_UNLOCK(p); 1646 continue; 1647 } 1648 err = p_cansignal(td, p, sig); 1649 if (err == 0) { 1650 if (sig) 1651 pksignal(p, sig, ksi); 1652 ret = err; 1653 } 1654 else if (ret == ESRCH) 1655 ret = err; 1656 PROC_UNLOCK(p); 1657 } 1658 PGRP_UNLOCK(pgrp); 1659 } 1660 return (ret); 1661 } 1662 1663 #ifndef _SYS_SYSPROTO_H_ 1664 struct kill_args { 1665 int pid; 1666 int signum; 1667 }; 1668 #endif 1669 /* ARGSUSED */ 1670 int 1671 sys_kill(struct thread *td, struct kill_args *uap) 1672 { 1673 ksiginfo_t ksi; 1674 struct proc *p; 1675 int error; 1676 1677 /* 1678 * A process in capability mode can send signals only to himself. 1679 * The main rationale behind this is that abort(3) is implemented as 1680 * kill(getpid(), SIGABRT). 1681 */ 1682 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1683 return (ECAPMODE); 1684 1685 AUDIT_ARG_SIGNUM(uap->signum); 1686 AUDIT_ARG_PID(uap->pid); 1687 if ((u_int)uap->signum > _SIG_MAXSIG) 1688 return (EINVAL); 1689 1690 ksiginfo_init(&ksi); 1691 ksi.ksi_signo = uap->signum; 1692 ksi.ksi_code = SI_USER; 1693 ksi.ksi_pid = td->td_proc->p_pid; 1694 ksi.ksi_uid = td->td_ucred->cr_ruid; 1695 1696 if (uap->pid > 0) { 1697 /* kill single process */ 1698 if ((p = pfind(uap->pid)) == NULL) { 1699 if ((p = zpfind(uap->pid)) == NULL) 1700 return (ESRCH); 1701 } 1702 AUDIT_ARG_PROCESS(p); 1703 error = p_cansignal(td, p, uap->signum); 1704 if (error == 0 && uap->signum) 1705 pksignal(p, uap->signum, &ksi); 1706 PROC_UNLOCK(p); 1707 return (error); 1708 } 1709 switch (uap->pid) { 1710 case -1: /* broadcast signal */ 1711 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1712 case 0: /* signal own process group */ 1713 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1714 default: /* negative explicit process group */ 1715 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1716 } 1717 /* NOTREACHED */ 1718 } 1719 1720 int 1721 sys_pdkill(td, uap) 1722 struct thread *td; 1723 struct pdkill_args *uap; 1724 { 1725 struct proc *p; 1726 cap_rights_t rights; 1727 int error; 1728 1729 AUDIT_ARG_SIGNUM(uap->signum); 1730 AUDIT_ARG_FD(uap->fd); 1731 if ((u_int)uap->signum > _SIG_MAXSIG) 1732 return (EINVAL); 1733 1734 error = procdesc_find(td, uap->fd, 1735 cap_rights_init(&rights, CAP_PDKILL), &p); 1736 if (error) 1737 return (error); 1738 AUDIT_ARG_PROCESS(p); 1739 error = p_cansignal(td, p, uap->signum); 1740 if (error == 0 && uap->signum) 1741 kern_psignal(p, uap->signum); 1742 PROC_UNLOCK(p); 1743 return (error); 1744 } 1745 1746 #if defined(COMPAT_43) 1747 #ifndef _SYS_SYSPROTO_H_ 1748 struct okillpg_args { 1749 int pgid; 1750 int signum; 1751 }; 1752 #endif 1753 /* ARGSUSED */ 1754 int 1755 okillpg(struct thread *td, struct okillpg_args *uap) 1756 { 1757 ksiginfo_t ksi; 1758 1759 AUDIT_ARG_SIGNUM(uap->signum); 1760 AUDIT_ARG_PID(uap->pgid); 1761 if ((u_int)uap->signum > _SIG_MAXSIG) 1762 return (EINVAL); 1763 1764 ksiginfo_init(&ksi); 1765 ksi.ksi_signo = uap->signum; 1766 ksi.ksi_code = SI_USER; 1767 ksi.ksi_pid = td->td_proc->p_pid; 1768 ksi.ksi_uid = td->td_ucred->cr_ruid; 1769 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1770 } 1771 #endif /* COMPAT_43 */ 1772 1773 #ifndef _SYS_SYSPROTO_H_ 1774 struct sigqueue_args { 1775 pid_t pid; 1776 int signum; 1777 /* union sigval */ void *value; 1778 }; 1779 #endif 1780 int 1781 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1782 { 1783 ksiginfo_t ksi; 1784 struct proc *p; 1785 int error; 1786 1787 if ((u_int)uap->signum > _SIG_MAXSIG) 1788 return (EINVAL); 1789 1790 /* 1791 * Specification says sigqueue can only send signal to 1792 * single process. 1793 */ 1794 if (uap->pid <= 0) 1795 return (EINVAL); 1796 1797 if ((p = pfind(uap->pid)) == NULL) { 1798 if ((p = zpfind(uap->pid)) == NULL) 1799 return (ESRCH); 1800 } 1801 error = p_cansignal(td, p, uap->signum); 1802 if (error == 0 && uap->signum != 0) { 1803 ksiginfo_init(&ksi); 1804 ksi.ksi_flags = KSI_SIGQ; 1805 ksi.ksi_signo = uap->signum; 1806 ksi.ksi_code = SI_QUEUE; 1807 ksi.ksi_pid = td->td_proc->p_pid; 1808 ksi.ksi_uid = td->td_ucred->cr_ruid; 1809 ksi.ksi_value.sival_ptr = uap->value; 1810 error = pksignal(p, ksi.ksi_signo, &ksi); 1811 } 1812 PROC_UNLOCK(p); 1813 return (error); 1814 } 1815 1816 /* 1817 * Send a signal to a process group. 1818 */ 1819 void 1820 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1821 { 1822 struct pgrp *pgrp; 1823 1824 if (pgid != 0) { 1825 sx_slock(&proctree_lock); 1826 pgrp = pgfind(pgid); 1827 sx_sunlock(&proctree_lock); 1828 if (pgrp != NULL) { 1829 pgsignal(pgrp, sig, 0, ksi); 1830 PGRP_UNLOCK(pgrp); 1831 } 1832 } 1833 } 1834 1835 /* 1836 * Send a signal to a process group. If checktty is 1, 1837 * limit to members which have a controlling terminal. 1838 */ 1839 void 1840 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1841 { 1842 struct proc *p; 1843 1844 if (pgrp) { 1845 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1846 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1847 PROC_LOCK(p); 1848 if (p->p_state == PRS_NORMAL && 1849 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1850 pksignal(p, sig, ksi); 1851 PROC_UNLOCK(p); 1852 } 1853 } 1854 } 1855 1856 /* 1857 * Send a signal caused by a trap to the current thread. If it will be 1858 * caught immediately, deliver it with correct code. Otherwise, post it 1859 * normally. 1860 */ 1861 void 1862 trapsignal(struct thread *td, ksiginfo_t *ksi) 1863 { 1864 struct sigacts *ps; 1865 sigset_t mask; 1866 struct proc *p; 1867 int sig; 1868 int code; 1869 1870 p = td->td_proc; 1871 sig = ksi->ksi_signo; 1872 code = ksi->ksi_code; 1873 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1874 1875 PROC_LOCK(p); 1876 ps = p->p_sigacts; 1877 mtx_lock(&ps->ps_mtx); 1878 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1879 !SIGISMEMBER(td->td_sigmask, sig)) { 1880 td->td_ru.ru_nsignals++; 1881 #ifdef KTRACE 1882 if (KTRPOINT(curthread, KTR_PSIG)) 1883 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1884 &td->td_sigmask, code); 1885 #endif 1886 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1887 ksi, &td->td_sigmask); 1888 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1889 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1890 SIGADDSET(mask, sig); 1891 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1892 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1893 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1894 /* 1895 * See kern_sigaction() for origin of this code. 1896 */ 1897 SIGDELSET(ps->ps_sigcatch, sig); 1898 if (sig != SIGCONT && 1899 sigprop(sig) & SA_IGNORE) 1900 SIGADDSET(ps->ps_sigignore, sig); 1901 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1902 } 1903 mtx_unlock(&ps->ps_mtx); 1904 } else { 1905 /* 1906 * Avoid a possible infinite loop if the thread 1907 * masking the signal or process is ignoring the 1908 * signal. 1909 */ 1910 if (kern_forcesigexit && 1911 (SIGISMEMBER(td->td_sigmask, sig) || 1912 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1913 SIGDELSET(td->td_sigmask, sig); 1914 SIGDELSET(ps->ps_sigcatch, sig); 1915 SIGDELSET(ps->ps_sigignore, sig); 1916 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1917 } 1918 mtx_unlock(&ps->ps_mtx); 1919 p->p_code = code; /* XXX for core dump/debugger */ 1920 p->p_sig = sig; /* XXX to verify code */ 1921 tdsendsignal(p, td, sig, ksi); 1922 } 1923 PROC_UNLOCK(p); 1924 } 1925 1926 static struct thread * 1927 sigtd(struct proc *p, int sig, int prop) 1928 { 1929 struct thread *td, *signal_td; 1930 1931 PROC_LOCK_ASSERT(p, MA_OWNED); 1932 1933 /* 1934 * Check if current thread can handle the signal without 1935 * switching context to another thread. 1936 */ 1937 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1938 return (curthread); 1939 signal_td = NULL; 1940 FOREACH_THREAD_IN_PROC(p, td) { 1941 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1942 signal_td = td; 1943 break; 1944 } 1945 } 1946 if (signal_td == NULL) 1947 signal_td = FIRST_THREAD_IN_PROC(p); 1948 return (signal_td); 1949 } 1950 1951 /* 1952 * Send the signal to the process. If the signal has an action, the action 1953 * is usually performed by the target process rather than the caller; we add 1954 * the signal to the set of pending signals for the process. 1955 * 1956 * Exceptions: 1957 * o When a stop signal is sent to a sleeping process that takes the 1958 * default action, the process is stopped without awakening it. 1959 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1960 * regardless of the signal action (eg, blocked or ignored). 1961 * 1962 * Other ignored signals are discarded immediately. 1963 * 1964 * NB: This function may be entered from the debugger via the "kill" DDB 1965 * command. There is little that can be done to mitigate the possibly messy 1966 * side effects of this unwise possibility. 1967 */ 1968 void 1969 kern_psignal(struct proc *p, int sig) 1970 { 1971 ksiginfo_t ksi; 1972 1973 ksiginfo_init(&ksi); 1974 ksi.ksi_signo = sig; 1975 ksi.ksi_code = SI_KERNEL; 1976 (void) tdsendsignal(p, NULL, sig, &ksi); 1977 } 1978 1979 int 1980 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1981 { 1982 1983 return (tdsendsignal(p, NULL, sig, ksi)); 1984 } 1985 1986 /* Utility function for finding a thread to send signal event to. */ 1987 int 1988 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1989 { 1990 struct thread *td; 1991 1992 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1993 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 1994 if (td == NULL) 1995 return (ESRCH); 1996 *ttd = td; 1997 } else { 1998 *ttd = NULL; 1999 PROC_LOCK(p); 2000 } 2001 return (0); 2002 } 2003 2004 void 2005 tdsignal(struct thread *td, int sig) 2006 { 2007 ksiginfo_t ksi; 2008 2009 ksiginfo_init(&ksi); 2010 ksi.ksi_signo = sig; 2011 ksi.ksi_code = SI_KERNEL; 2012 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2013 } 2014 2015 void 2016 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2017 { 2018 2019 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2020 } 2021 2022 int 2023 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2024 { 2025 sig_t action; 2026 sigqueue_t *sigqueue; 2027 int prop; 2028 struct sigacts *ps; 2029 int intrval; 2030 int ret = 0; 2031 int wakeup_swapper; 2032 2033 MPASS(td == NULL || p == td->td_proc); 2034 PROC_LOCK_ASSERT(p, MA_OWNED); 2035 2036 if (!_SIG_VALID(sig)) 2037 panic("%s(): invalid signal %d", __func__, sig); 2038 2039 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2040 2041 /* 2042 * IEEE Std 1003.1-2001: return success when killing a zombie. 2043 */ 2044 if (p->p_state == PRS_ZOMBIE) { 2045 if (ksi && (ksi->ksi_flags & KSI_INS)) 2046 ksiginfo_tryfree(ksi); 2047 return (ret); 2048 } 2049 2050 ps = p->p_sigacts; 2051 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2052 prop = sigprop(sig); 2053 2054 if (td == NULL) { 2055 td = sigtd(p, sig, prop); 2056 sigqueue = &p->p_sigqueue; 2057 } else 2058 sigqueue = &td->td_sigqueue; 2059 2060 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 ); 2061 2062 /* 2063 * If the signal is being ignored, 2064 * then we forget about it immediately. 2065 * (Note: we don't set SIGCONT in ps_sigignore, 2066 * and if it is set to SIG_IGN, 2067 * action will be SIG_DFL here.) 2068 */ 2069 mtx_lock(&ps->ps_mtx); 2070 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2071 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 ); 2072 2073 mtx_unlock(&ps->ps_mtx); 2074 if (ksi && (ksi->ksi_flags & KSI_INS)) 2075 ksiginfo_tryfree(ksi); 2076 return (ret); 2077 } 2078 if (SIGISMEMBER(td->td_sigmask, sig)) 2079 action = SIG_HOLD; 2080 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2081 action = SIG_CATCH; 2082 else 2083 action = SIG_DFL; 2084 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2085 intrval = EINTR; 2086 else 2087 intrval = ERESTART; 2088 mtx_unlock(&ps->ps_mtx); 2089 2090 if (prop & SA_CONT) 2091 sigqueue_delete_stopmask_proc(p); 2092 else if (prop & SA_STOP) { 2093 /* 2094 * If sending a tty stop signal to a member of an orphaned 2095 * process group, discard the signal here if the action 2096 * is default; don't stop the process below if sleeping, 2097 * and don't clear any pending SIGCONT. 2098 */ 2099 if ((prop & SA_TTYSTOP) && 2100 (p->p_pgrp->pg_jobc == 0) && 2101 (action == SIG_DFL)) { 2102 if (ksi && (ksi->ksi_flags & KSI_INS)) 2103 ksiginfo_tryfree(ksi); 2104 return (ret); 2105 } 2106 sigqueue_delete_proc(p, SIGCONT); 2107 if (p->p_flag & P_CONTINUED) { 2108 p->p_flag &= ~P_CONTINUED; 2109 PROC_LOCK(p->p_pptr); 2110 sigqueue_take(p->p_ksi); 2111 PROC_UNLOCK(p->p_pptr); 2112 } 2113 } 2114 2115 ret = sigqueue_add(sigqueue, sig, ksi); 2116 if (ret != 0) 2117 return (ret); 2118 signotify(td); 2119 /* 2120 * Defer further processing for signals which are held, 2121 * except that stopped processes must be continued by SIGCONT. 2122 */ 2123 if (action == SIG_HOLD && 2124 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2125 return (ret); 2126 /* 2127 * SIGKILL: Remove procfs STOPEVENTs. 2128 */ 2129 if (sig == SIGKILL) { 2130 /* from procfs_ioctl.c: PIOCBIC */ 2131 p->p_stops = 0; 2132 /* from procfs_ioctl.c: PIOCCONT */ 2133 p->p_step = 0; 2134 wakeup(&p->p_step); 2135 } 2136 /* 2137 * Some signals have a process-wide effect and a per-thread 2138 * component. Most processing occurs when the process next 2139 * tries to cross the user boundary, however there are some 2140 * times when processing needs to be done immediately, such as 2141 * waking up threads so that they can cross the user boundary. 2142 * We try to do the per-process part here. 2143 */ 2144 if (P_SHOULDSTOP(p)) { 2145 KASSERT(!(p->p_flag & P_WEXIT), 2146 ("signal to stopped but exiting process")); 2147 if (sig == SIGKILL) { 2148 /* 2149 * If traced process is already stopped, 2150 * then no further action is necessary. 2151 */ 2152 if (p->p_flag & P_TRACED) 2153 goto out; 2154 /* 2155 * SIGKILL sets process running. 2156 * It will die elsewhere. 2157 * All threads must be restarted. 2158 */ 2159 p->p_flag &= ~P_STOPPED_SIG; 2160 goto runfast; 2161 } 2162 2163 if (prop & SA_CONT) { 2164 /* 2165 * If traced process is already stopped, 2166 * then no further action is necessary. 2167 */ 2168 if (p->p_flag & P_TRACED) 2169 goto out; 2170 /* 2171 * If SIGCONT is default (or ignored), we continue the 2172 * process but don't leave the signal in sigqueue as 2173 * it has no further action. If SIGCONT is held, we 2174 * continue the process and leave the signal in 2175 * sigqueue. If the process catches SIGCONT, let it 2176 * handle the signal itself. If it isn't waiting on 2177 * an event, it goes back to run state. 2178 * Otherwise, process goes back to sleep state. 2179 */ 2180 p->p_flag &= ~P_STOPPED_SIG; 2181 PROC_SLOCK(p); 2182 if (p->p_numthreads == p->p_suspcount) { 2183 PROC_SUNLOCK(p); 2184 p->p_flag |= P_CONTINUED; 2185 p->p_xstat = SIGCONT; 2186 PROC_LOCK(p->p_pptr); 2187 childproc_continued(p); 2188 PROC_UNLOCK(p->p_pptr); 2189 PROC_SLOCK(p); 2190 } 2191 if (action == SIG_DFL) { 2192 thread_unsuspend(p); 2193 PROC_SUNLOCK(p); 2194 sigqueue_delete(sigqueue, sig); 2195 goto out; 2196 } 2197 if (action == SIG_CATCH) { 2198 /* 2199 * The process wants to catch it so it needs 2200 * to run at least one thread, but which one? 2201 */ 2202 PROC_SUNLOCK(p); 2203 goto runfast; 2204 } 2205 /* 2206 * The signal is not ignored or caught. 2207 */ 2208 thread_unsuspend(p); 2209 PROC_SUNLOCK(p); 2210 goto out; 2211 } 2212 2213 if (prop & SA_STOP) { 2214 /* 2215 * If traced process is already stopped, 2216 * then no further action is necessary. 2217 */ 2218 if (p->p_flag & P_TRACED) 2219 goto out; 2220 /* 2221 * Already stopped, don't need to stop again 2222 * (If we did the shell could get confused). 2223 * Just make sure the signal STOP bit set. 2224 */ 2225 p->p_flag |= P_STOPPED_SIG; 2226 sigqueue_delete(sigqueue, sig); 2227 goto out; 2228 } 2229 2230 /* 2231 * All other kinds of signals: 2232 * If a thread is sleeping interruptibly, simulate a 2233 * wakeup so that when it is continued it will be made 2234 * runnable and can look at the signal. However, don't make 2235 * the PROCESS runnable, leave it stopped. 2236 * It may run a bit until it hits a thread_suspend_check(). 2237 */ 2238 wakeup_swapper = 0; 2239 PROC_SLOCK(p); 2240 thread_lock(td); 2241 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2242 wakeup_swapper = sleepq_abort(td, intrval); 2243 thread_unlock(td); 2244 PROC_SUNLOCK(p); 2245 if (wakeup_swapper) 2246 kick_proc0(); 2247 goto out; 2248 /* 2249 * Mutexes are short lived. Threads waiting on them will 2250 * hit thread_suspend_check() soon. 2251 */ 2252 } else if (p->p_state == PRS_NORMAL) { 2253 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2254 tdsigwakeup(td, sig, action, intrval); 2255 goto out; 2256 } 2257 2258 MPASS(action == SIG_DFL); 2259 2260 if (prop & SA_STOP) { 2261 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2262 goto out; 2263 p->p_flag |= P_STOPPED_SIG; 2264 p->p_xstat = sig; 2265 PROC_SLOCK(p); 2266 sig_suspend_threads(td, p, 1); 2267 if (p->p_numthreads == p->p_suspcount) { 2268 /* 2269 * only thread sending signal to another 2270 * process can reach here, if thread is sending 2271 * signal to its process, because thread does 2272 * not suspend itself here, p_numthreads 2273 * should never be equal to p_suspcount. 2274 */ 2275 thread_stopped(p); 2276 PROC_SUNLOCK(p); 2277 sigqueue_delete_proc(p, p->p_xstat); 2278 } else 2279 PROC_SUNLOCK(p); 2280 goto out; 2281 } 2282 } else { 2283 /* Not in "NORMAL" state. discard the signal. */ 2284 sigqueue_delete(sigqueue, sig); 2285 goto out; 2286 } 2287 2288 /* 2289 * The process is not stopped so we need to apply the signal to all the 2290 * running threads. 2291 */ 2292 runfast: 2293 tdsigwakeup(td, sig, action, intrval); 2294 PROC_SLOCK(p); 2295 thread_unsuspend(p); 2296 PROC_SUNLOCK(p); 2297 out: 2298 /* If we jump here, proc slock should not be owned. */ 2299 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2300 return (ret); 2301 } 2302 2303 /* 2304 * The force of a signal has been directed against a single 2305 * thread. We need to see what we can do about knocking it 2306 * out of any sleep it may be in etc. 2307 */ 2308 static void 2309 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2310 { 2311 struct proc *p = td->td_proc; 2312 register int prop; 2313 int wakeup_swapper; 2314 2315 wakeup_swapper = 0; 2316 PROC_LOCK_ASSERT(p, MA_OWNED); 2317 prop = sigprop(sig); 2318 2319 PROC_SLOCK(p); 2320 thread_lock(td); 2321 /* 2322 * Bring the priority of a thread up if we want it to get 2323 * killed in this lifetime. 2324 */ 2325 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2326 sched_prio(td, PUSER); 2327 if (TD_ON_SLEEPQ(td)) { 2328 /* 2329 * If thread is sleeping uninterruptibly 2330 * we can't interrupt the sleep... the signal will 2331 * be noticed when the process returns through 2332 * trap() or syscall(). 2333 */ 2334 if ((td->td_flags & TDF_SINTR) == 0) 2335 goto out; 2336 /* 2337 * If SIGCONT is default (or ignored) and process is 2338 * asleep, we are finished; the process should not 2339 * be awakened. 2340 */ 2341 if ((prop & SA_CONT) && action == SIG_DFL) { 2342 thread_unlock(td); 2343 PROC_SUNLOCK(p); 2344 sigqueue_delete(&p->p_sigqueue, sig); 2345 /* 2346 * It may be on either list in this state. 2347 * Remove from both for now. 2348 */ 2349 sigqueue_delete(&td->td_sigqueue, sig); 2350 return; 2351 } 2352 2353 /* 2354 * Don't awaken a sleeping thread for SIGSTOP if the 2355 * STOP signal is deferred. 2356 */ 2357 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2358 goto out; 2359 2360 /* 2361 * Give low priority threads a better chance to run. 2362 */ 2363 if (td->td_priority > PUSER) 2364 sched_prio(td, PUSER); 2365 2366 wakeup_swapper = sleepq_abort(td, intrval); 2367 } else { 2368 /* 2369 * Other states do nothing with the signal immediately, 2370 * other than kicking ourselves if we are running. 2371 * It will either never be noticed, or noticed very soon. 2372 */ 2373 #ifdef SMP 2374 if (TD_IS_RUNNING(td) && td != curthread) 2375 forward_signal(td); 2376 #endif 2377 } 2378 out: 2379 PROC_SUNLOCK(p); 2380 thread_unlock(td); 2381 if (wakeup_swapper) 2382 kick_proc0(); 2383 } 2384 2385 static void 2386 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2387 { 2388 struct thread *td2; 2389 2390 PROC_LOCK_ASSERT(p, MA_OWNED); 2391 PROC_SLOCK_ASSERT(p, MA_OWNED); 2392 2393 FOREACH_THREAD_IN_PROC(p, td2) { 2394 thread_lock(td2); 2395 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2396 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2397 (td2->td_flags & TDF_SINTR)) { 2398 if (td2->td_flags & TDF_SBDRY) { 2399 /* 2400 * Once a thread is asleep with 2401 * TDF_SBDRY set, it should never 2402 * become suspended due to this check. 2403 */ 2404 KASSERT(!TD_IS_SUSPENDED(td2), 2405 ("thread with deferred stops suspended")); 2406 } else if (!TD_IS_SUSPENDED(td2)) { 2407 thread_suspend_one(td2); 2408 } 2409 } else if (!TD_IS_SUSPENDED(td2)) { 2410 if (sending || td != td2) 2411 td2->td_flags |= TDF_ASTPENDING; 2412 #ifdef SMP 2413 if (TD_IS_RUNNING(td2) && td2 != td) 2414 forward_signal(td2); 2415 #endif 2416 } 2417 thread_unlock(td2); 2418 } 2419 } 2420 2421 int 2422 ptracestop(struct thread *td, int sig) 2423 { 2424 struct proc *p = td->td_proc; 2425 2426 PROC_LOCK_ASSERT(p, MA_OWNED); 2427 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2428 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2429 &p->p_mtx.lock_object, "Stopping for traced signal"); 2430 2431 td->td_dbgflags |= TDB_XSIG; 2432 td->td_xsig = sig; 2433 PROC_SLOCK(p); 2434 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2435 if (p->p_flag & P_SINGLE_EXIT) { 2436 td->td_dbgflags &= ~TDB_XSIG; 2437 PROC_SUNLOCK(p); 2438 return (sig); 2439 } 2440 /* 2441 * Just make wait() to work, the last stopped thread 2442 * will win. 2443 */ 2444 p->p_xstat = sig; 2445 p->p_xthread = td; 2446 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2447 sig_suspend_threads(td, p, 0); 2448 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2449 td->td_dbgflags &= ~TDB_STOPATFORK; 2450 cv_broadcast(&p->p_dbgwait); 2451 } 2452 stopme: 2453 thread_suspend_switch(td); 2454 if (p->p_xthread == td) 2455 p->p_xthread = NULL; 2456 if (!(p->p_flag & P_TRACED)) 2457 break; 2458 if (td->td_dbgflags & TDB_SUSPEND) { 2459 if (p->p_flag & P_SINGLE_EXIT) 2460 break; 2461 goto stopme; 2462 } 2463 } 2464 PROC_SUNLOCK(p); 2465 return (td->td_xsig); 2466 } 2467 2468 static void 2469 reschedule_signals(struct proc *p, sigset_t block, int flags) 2470 { 2471 struct sigacts *ps; 2472 struct thread *td; 2473 int sig; 2474 2475 PROC_LOCK_ASSERT(p, MA_OWNED); 2476 if (SIGISEMPTY(p->p_siglist)) 2477 return; 2478 ps = p->p_sigacts; 2479 SIGSETAND(block, p->p_siglist); 2480 while ((sig = sig_ffs(&block)) != 0) { 2481 SIGDELSET(block, sig); 2482 td = sigtd(p, sig, 0); 2483 signotify(td); 2484 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2485 mtx_lock(&ps->ps_mtx); 2486 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2487 tdsigwakeup(td, sig, SIG_CATCH, 2488 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2489 ERESTART)); 2490 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2491 mtx_unlock(&ps->ps_mtx); 2492 } 2493 } 2494 2495 void 2496 tdsigcleanup(struct thread *td) 2497 { 2498 struct proc *p; 2499 sigset_t unblocked; 2500 2501 p = td->td_proc; 2502 PROC_LOCK_ASSERT(p, MA_OWNED); 2503 2504 sigqueue_flush(&td->td_sigqueue); 2505 if (p->p_numthreads == 1) 2506 return; 2507 2508 /* 2509 * Since we cannot handle signals, notify signal post code 2510 * about this by filling the sigmask. 2511 * 2512 * Also, if needed, wake up thread(s) that do not block the 2513 * same signals as the exiting thread, since the thread might 2514 * have been selected for delivery and woken up. 2515 */ 2516 SIGFILLSET(unblocked); 2517 SIGSETNAND(unblocked, td->td_sigmask); 2518 SIGFILLSET(td->td_sigmask); 2519 reschedule_signals(p, unblocked, 0); 2520 2521 } 2522 2523 /* 2524 * Defer the delivery of SIGSTOP for the current thread. Returns true 2525 * if stops were deferred and false if they were already deferred. 2526 */ 2527 int 2528 sigdeferstop(void) 2529 { 2530 struct thread *td; 2531 2532 td = curthread; 2533 if (td->td_flags & TDF_SBDRY) 2534 return (0); 2535 thread_lock(td); 2536 td->td_flags |= TDF_SBDRY; 2537 thread_unlock(td); 2538 return (1); 2539 } 2540 2541 /* 2542 * Permit the delivery of SIGSTOP for the current thread. This does 2543 * not immediately suspend if a stop was posted. Instead, the thread 2544 * will suspend either via ast() or a subsequent interruptible sleep. 2545 */ 2546 void 2547 sigallowstop() 2548 { 2549 struct thread *td; 2550 2551 td = curthread; 2552 thread_lock(td); 2553 td->td_flags &= ~TDF_SBDRY; 2554 thread_unlock(td); 2555 } 2556 2557 /* 2558 * If the current process has received a signal (should be caught or cause 2559 * termination, should interrupt current syscall), return the signal number. 2560 * Stop signals with default action are processed immediately, then cleared; 2561 * they aren't returned. This is checked after each entry to the system for 2562 * a syscall or trap (though this can usually be done without calling issignal 2563 * by checking the pending signal masks in cursig.) The normal call 2564 * sequence is 2565 * 2566 * while (sig = cursig(curthread)) 2567 * postsig(sig); 2568 */ 2569 static int 2570 issignal(struct thread *td) 2571 { 2572 struct proc *p; 2573 struct sigacts *ps; 2574 struct sigqueue *queue; 2575 sigset_t sigpending; 2576 int sig, prop, newsig; 2577 2578 p = td->td_proc; 2579 ps = p->p_sigacts; 2580 mtx_assert(&ps->ps_mtx, MA_OWNED); 2581 PROC_LOCK_ASSERT(p, MA_OWNED); 2582 for (;;) { 2583 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2584 2585 sigpending = td->td_sigqueue.sq_signals; 2586 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2587 SIGSETNAND(sigpending, td->td_sigmask); 2588 2589 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2590 SIG_STOPSIGMASK(sigpending); 2591 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2592 return (0); 2593 sig = sig_ffs(&sigpending); 2594 2595 if (p->p_stops & S_SIG) { 2596 mtx_unlock(&ps->ps_mtx); 2597 stopevent(p, S_SIG, sig); 2598 mtx_lock(&ps->ps_mtx); 2599 } 2600 2601 /* 2602 * We should see pending but ignored signals 2603 * only if P_TRACED was on when they were posted. 2604 */ 2605 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2606 sigqueue_delete(&td->td_sigqueue, sig); 2607 sigqueue_delete(&p->p_sigqueue, sig); 2608 continue; 2609 } 2610 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2611 /* 2612 * If traced, always stop. 2613 * Remove old signal from queue before the stop. 2614 * XXX shrug off debugger, it causes siginfo to 2615 * be thrown away. 2616 */ 2617 queue = &td->td_sigqueue; 2618 td->td_dbgksi.ksi_signo = 0; 2619 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2620 queue = &p->p_sigqueue; 2621 sigqueue_get(queue, sig, &td->td_dbgksi); 2622 } 2623 2624 mtx_unlock(&ps->ps_mtx); 2625 newsig = ptracestop(td, sig); 2626 mtx_lock(&ps->ps_mtx); 2627 2628 if (sig != newsig) { 2629 2630 /* 2631 * If parent wants us to take the signal, 2632 * then it will leave it in p->p_xstat; 2633 * otherwise we just look for signals again. 2634 */ 2635 if (newsig == 0) 2636 continue; 2637 sig = newsig; 2638 2639 /* 2640 * Put the new signal into td_sigqueue. If the 2641 * signal is being masked, look for other 2642 * signals. 2643 */ 2644 sigqueue_add(queue, sig, NULL); 2645 if (SIGISMEMBER(td->td_sigmask, sig)) 2646 continue; 2647 signotify(td); 2648 } else { 2649 if (td->td_dbgksi.ksi_signo != 0) { 2650 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2651 if (sigqueue_add(&td->td_sigqueue, sig, 2652 &td->td_dbgksi) != 0) 2653 td->td_dbgksi.ksi_signo = 0; 2654 } 2655 if (td->td_dbgksi.ksi_signo == 0) 2656 sigqueue_add(&td->td_sigqueue, sig, 2657 NULL); 2658 } 2659 2660 /* 2661 * If the traced bit got turned off, go back up 2662 * to the top to rescan signals. This ensures 2663 * that p_sig* and p_sigact are consistent. 2664 */ 2665 if ((p->p_flag & P_TRACED) == 0) 2666 continue; 2667 } 2668 2669 prop = sigprop(sig); 2670 2671 /* 2672 * Decide whether the signal should be returned. 2673 * Return the signal's number, or fall through 2674 * to clear it from the pending mask. 2675 */ 2676 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2677 2678 case (intptr_t)SIG_DFL: 2679 /* 2680 * Don't take default actions on system processes. 2681 */ 2682 if (p->p_pid <= 1) { 2683 #ifdef DIAGNOSTIC 2684 /* 2685 * Are you sure you want to ignore SIGSEGV 2686 * in init? XXX 2687 */ 2688 printf("Process (pid %lu) got signal %d\n", 2689 (u_long)p->p_pid, sig); 2690 #endif 2691 break; /* == ignore */ 2692 } 2693 /* 2694 * If there is a pending stop signal to process 2695 * with default action, stop here, 2696 * then clear the signal. However, 2697 * if process is member of an orphaned 2698 * process group, ignore tty stop signals. 2699 */ 2700 if (prop & SA_STOP) { 2701 if (p->p_flag & (P_TRACED|P_WEXIT) || 2702 (p->p_pgrp->pg_jobc == 0 && 2703 prop & SA_TTYSTOP)) 2704 break; /* == ignore */ 2705 mtx_unlock(&ps->ps_mtx); 2706 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2707 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2708 p->p_flag |= P_STOPPED_SIG; 2709 p->p_xstat = sig; 2710 PROC_SLOCK(p); 2711 sig_suspend_threads(td, p, 0); 2712 thread_suspend_switch(td); 2713 PROC_SUNLOCK(p); 2714 mtx_lock(&ps->ps_mtx); 2715 break; 2716 } else if (prop & SA_IGNORE) { 2717 /* 2718 * Except for SIGCONT, shouldn't get here. 2719 * Default action is to ignore; drop it. 2720 */ 2721 break; /* == ignore */ 2722 } else 2723 return (sig); 2724 /*NOTREACHED*/ 2725 2726 case (intptr_t)SIG_IGN: 2727 /* 2728 * Masking above should prevent us ever trying 2729 * to take action on an ignored signal other 2730 * than SIGCONT, unless process is traced. 2731 */ 2732 if ((prop & SA_CONT) == 0 && 2733 (p->p_flag & P_TRACED) == 0) 2734 printf("issignal\n"); 2735 break; /* == ignore */ 2736 2737 default: 2738 /* 2739 * This signal has an action, let 2740 * postsig() process it. 2741 */ 2742 return (sig); 2743 } 2744 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2745 sigqueue_delete(&p->p_sigqueue, sig); 2746 } 2747 /* NOTREACHED */ 2748 } 2749 2750 void 2751 thread_stopped(struct proc *p) 2752 { 2753 int n; 2754 2755 PROC_LOCK_ASSERT(p, MA_OWNED); 2756 PROC_SLOCK_ASSERT(p, MA_OWNED); 2757 n = p->p_suspcount; 2758 if (p == curproc) 2759 n++; 2760 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2761 PROC_SUNLOCK(p); 2762 p->p_flag &= ~P_WAITED; 2763 PROC_LOCK(p->p_pptr); 2764 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2765 CLD_TRAPPED : CLD_STOPPED); 2766 PROC_UNLOCK(p->p_pptr); 2767 PROC_SLOCK(p); 2768 } 2769 } 2770 2771 /* 2772 * Take the action for the specified signal 2773 * from the current set of pending signals. 2774 */ 2775 int 2776 postsig(sig) 2777 register int sig; 2778 { 2779 struct thread *td = curthread; 2780 register struct proc *p = td->td_proc; 2781 struct sigacts *ps; 2782 sig_t action; 2783 ksiginfo_t ksi; 2784 sigset_t returnmask, mask; 2785 2786 KASSERT(sig != 0, ("postsig")); 2787 2788 PROC_LOCK_ASSERT(p, MA_OWNED); 2789 ps = p->p_sigacts; 2790 mtx_assert(&ps->ps_mtx, MA_OWNED); 2791 ksiginfo_init(&ksi); 2792 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2793 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2794 return (0); 2795 ksi.ksi_signo = sig; 2796 if (ksi.ksi_code == SI_TIMER) 2797 itimer_accept(p, ksi.ksi_timerid, &ksi); 2798 action = ps->ps_sigact[_SIG_IDX(sig)]; 2799 #ifdef KTRACE 2800 if (KTRPOINT(td, KTR_PSIG)) 2801 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2802 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2803 #endif 2804 if (p->p_stops & S_SIG) { 2805 mtx_unlock(&ps->ps_mtx); 2806 stopevent(p, S_SIG, sig); 2807 mtx_lock(&ps->ps_mtx); 2808 } 2809 2810 if (action == SIG_DFL) { 2811 /* 2812 * Default action, where the default is to kill 2813 * the process. (Other cases were ignored above.) 2814 */ 2815 mtx_unlock(&ps->ps_mtx); 2816 sigexit(td, sig); 2817 /* NOTREACHED */ 2818 } else { 2819 /* 2820 * If we get here, the signal must be caught. 2821 */ 2822 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2823 ("postsig action")); 2824 /* 2825 * Set the new mask value and also defer further 2826 * occurrences of this signal. 2827 * 2828 * Special case: user has done a sigsuspend. Here the 2829 * current mask is not of interest, but rather the 2830 * mask from before the sigsuspend is what we want 2831 * restored after the signal processing is completed. 2832 */ 2833 if (td->td_pflags & TDP_OLDMASK) { 2834 returnmask = td->td_oldsigmask; 2835 td->td_pflags &= ~TDP_OLDMASK; 2836 } else 2837 returnmask = td->td_sigmask; 2838 2839 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2840 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2841 SIGADDSET(mask, sig); 2842 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2843 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2844 2845 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2846 /* 2847 * See kern_sigaction() for origin of this code. 2848 */ 2849 SIGDELSET(ps->ps_sigcatch, sig); 2850 if (sig != SIGCONT && 2851 sigprop(sig) & SA_IGNORE) 2852 SIGADDSET(ps->ps_sigignore, sig); 2853 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2854 } 2855 td->td_ru.ru_nsignals++; 2856 if (p->p_sig == sig) { 2857 p->p_code = 0; 2858 p->p_sig = 0; 2859 } 2860 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2861 } 2862 return (1); 2863 } 2864 2865 /* 2866 * Kill the current process for stated reason. 2867 */ 2868 void 2869 killproc(p, why) 2870 struct proc *p; 2871 char *why; 2872 { 2873 2874 PROC_LOCK_ASSERT(p, MA_OWNED); 2875 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2876 p->p_comm); 2877 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2878 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2879 p->p_flag |= P_WKILLED; 2880 kern_psignal(p, SIGKILL); 2881 } 2882 2883 /* 2884 * Force the current process to exit with the specified signal, dumping core 2885 * if appropriate. We bypass the normal tests for masked and caught signals, 2886 * allowing unrecoverable failures to terminate the process without changing 2887 * signal state. Mark the accounting record with the signal termination. 2888 * If dumping core, save the signal number for the debugger. Calls exit and 2889 * does not return. 2890 */ 2891 void 2892 sigexit(td, sig) 2893 struct thread *td; 2894 int sig; 2895 { 2896 struct proc *p = td->td_proc; 2897 2898 PROC_LOCK_ASSERT(p, MA_OWNED); 2899 p->p_acflag |= AXSIG; 2900 /* 2901 * We must be single-threading to generate a core dump. This 2902 * ensures that the registers in the core file are up-to-date. 2903 * Also, the ELF dump handler assumes that the thread list doesn't 2904 * change out from under it. 2905 * 2906 * XXX If another thread attempts to single-thread before us 2907 * (e.g. via fork()), we won't get a dump at all. 2908 */ 2909 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2910 p->p_sig = sig; 2911 /* 2912 * Log signals which would cause core dumps 2913 * (Log as LOG_INFO to appease those who don't want 2914 * these messages.) 2915 * XXX : Todo, as well as euid, write out ruid too 2916 * Note that coredump() drops proc lock. 2917 */ 2918 if (coredump(td) == 0) 2919 sig |= WCOREFLAG; 2920 if (kern_logsigexit) 2921 log(LOG_INFO, 2922 "pid %d (%s), uid %d: exited on signal %d%s\n", 2923 p->p_pid, p->p_comm, 2924 td->td_ucred ? td->td_ucred->cr_uid : -1, 2925 sig &~ WCOREFLAG, 2926 sig & WCOREFLAG ? " (core dumped)" : ""); 2927 } else 2928 PROC_UNLOCK(p); 2929 exit1(td, W_EXITCODE(0, sig)); 2930 /* NOTREACHED */ 2931 } 2932 2933 /* 2934 * Send queued SIGCHLD to parent when child process's state 2935 * is changed. 2936 */ 2937 static void 2938 sigparent(struct proc *p, int reason, int status) 2939 { 2940 PROC_LOCK_ASSERT(p, MA_OWNED); 2941 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2942 2943 if (p->p_ksi != NULL) { 2944 p->p_ksi->ksi_signo = SIGCHLD; 2945 p->p_ksi->ksi_code = reason; 2946 p->p_ksi->ksi_status = status; 2947 p->p_ksi->ksi_pid = p->p_pid; 2948 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2949 if (KSI_ONQ(p->p_ksi)) 2950 return; 2951 } 2952 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2953 } 2954 2955 static void 2956 childproc_jobstate(struct proc *p, int reason, int sig) 2957 { 2958 struct sigacts *ps; 2959 2960 PROC_LOCK_ASSERT(p, MA_OWNED); 2961 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2962 2963 /* 2964 * Wake up parent sleeping in kern_wait(), also send 2965 * SIGCHLD to parent, but SIGCHLD does not guarantee 2966 * that parent will awake, because parent may masked 2967 * the signal. 2968 */ 2969 p->p_pptr->p_flag |= P_STATCHILD; 2970 wakeup(p->p_pptr); 2971 2972 ps = p->p_pptr->p_sigacts; 2973 mtx_lock(&ps->ps_mtx); 2974 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2975 mtx_unlock(&ps->ps_mtx); 2976 sigparent(p, reason, sig); 2977 } else 2978 mtx_unlock(&ps->ps_mtx); 2979 } 2980 2981 void 2982 childproc_stopped(struct proc *p, int reason) 2983 { 2984 /* p_xstat is a plain signal number, not a full wait() status here. */ 2985 childproc_jobstate(p, reason, p->p_xstat); 2986 } 2987 2988 void 2989 childproc_continued(struct proc *p) 2990 { 2991 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2992 } 2993 2994 void 2995 childproc_exited(struct proc *p) 2996 { 2997 int reason; 2998 int xstat = p->p_xstat; /* convert to int */ 2999 int status; 3000 3001 if (WCOREDUMP(xstat)) 3002 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3003 else if (WIFSIGNALED(xstat)) 3004 reason = CLD_KILLED, status = WTERMSIG(xstat); 3005 else 3006 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3007 /* 3008 * XXX avoid calling wakeup(p->p_pptr), the work is 3009 * done in exit1(). 3010 */ 3011 sigparent(p, reason, status); 3012 } 3013 3014 /* 3015 * We only have 1 character for the core count in the format 3016 * string, so the range will be 0-9 3017 */ 3018 #define MAX_NUM_CORES 10 3019 static int num_cores = 5; 3020 3021 static int 3022 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3023 { 3024 int error; 3025 int new_val; 3026 3027 new_val = num_cores; 3028 error = sysctl_handle_int(oidp, &new_val, 0, req); 3029 if (error != 0 || req->newptr == NULL) 3030 return (error); 3031 if (new_val > MAX_NUM_CORES) 3032 new_val = MAX_NUM_CORES; 3033 if (new_val < 0) 3034 new_val = 0; 3035 num_cores = new_val; 3036 return (0); 3037 } 3038 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3039 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3040 3041 #if defined(COMPRESS_USER_CORES) 3042 int compress_user_cores = 1; 3043 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3044 &compress_user_cores, 0, "Compression of user corefiles"); 3045 3046 int compress_user_cores_gzlevel = -1; /* default level */ 3047 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3048 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3049 3050 #define GZ_SUFFIX ".gz" 3051 #define GZ_SUFFIX_LEN 3 3052 #endif 3053 3054 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3055 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3056 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3057 sizeof(corefilename), "Process corefile name format string"); 3058 3059 /* 3060 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3061 * Expand the name described in corefilename, using name, uid, and pid 3062 * and open/create core file. 3063 * corefilename is a printf-like string, with three format specifiers: 3064 * %N name of process ("name") 3065 * %P process id (pid) 3066 * %U user id (uid) 3067 * For example, "%N.core" is the default; they can be disabled completely 3068 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3069 * This is controlled by the sysctl variable kern.corefile (see above). 3070 */ 3071 static int 3072 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3073 int compress, struct vnode **vpp, char **namep) 3074 { 3075 struct nameidata nd; 3076 struct sbuf sb; 3077 const char *format; 3078 char *hostname, *name; 3079 int indexpos, i, error, cmode, flags, oflags; 3080 3081 hostname = NULL; 3082 format = corefilename; 3083 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3084 indexpos = -1; 3085 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3086 for (i = 0; format[i] != '\0'; i++) { 3087 switch (format[i]) { 3088 case '%': /* Format character */ 3089 i++; 3090 switch (format[i]) { 3091 case '%': 3092 sbuf_putc(&sb, '%'); 3093 break; 3094 case 'H': /* hostname */ 3095 if (hostname == NULL) { 3096 hostname = malloc(MAXHOSTNAMELEN, 3097 M_TEMP, M_WAITOK); 3098 } 3099 getcredhostname(td->td_ucred, hostname, 3100 MAXHOSTNAMELEN); 3101 sbuf_printf(&sb, "%s", hostname); 3102 break; 3103 case 'I': /* autoincrementing index */ 3104 sbuf_printf(&sb, "0"); 3105 indexpos = sbuf_len(&sb) - 1; 3106 break; 3107 case 'N': /* process name */ 3108 sbuf_printf(&sb, "%s", comm); 3109 break; 3110 case 'P': /* process id */ 3111 sbuf_printf(&sb, "%u", pid); 3112 break; 3113 case 'U': /* user id */ 3114 sbuf_printf(&sb, "%u", uid); 3115 break; 3116 default: 3117 log(LOG_ERR, 3118 "Unknown format character %c in " 3119 "corename `%s'\n", format[i], format); 3120 break; 3121 } 3122 break; 3123 default: 3124 sbuf_putc(&sb, format[i]); 3125 break; 3126 } 3127 } 3128 free(hostname, M_TEMP); 3129 #ifdef COMPRESS_USER_CORES 3130 if (compress) 3131 sbuf_printf(&sb, GZ_SUFFIX); 3132 #endif 3133 if (sbuf_error(&sb) != 0) { 3134 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3135 "long\n", (long)pid, comm, (u_long)uid); 3136 sbuf_delete(&sb); 3137 free(name, M_TEMP); 3138 return (ENOMEM); 3139 } 3140 sbuf_finish(&sb); 3141 sbuf_delete(&sb); 3142 3143 cmode = S_IRUSR | S_IWUSR; 3144 oflags = VN_OPEN_NOAUDIT | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3145 3146 /* 3147 * If the core format has a %I in it, then we need to check 3148 * for existing corefiles before returning a name. 3149 * To do this we iterate over 0..num_cores to find a 3150 * non-existing core file name to use. 3151 */ 3152 if (indexpos != -1) { 3153 for (i = 0; i < num_cores; i++) { 3154 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3155 name[indexpos] = '0' + i; 3156 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3157 error = vn_open_cred(&nd, &flags, cmode, oflags, 3158 td->td_ucred, NULL); 3159 if (error) { 3160 if (error == EEXIST) 3161 continue; 3162 log(LOG_ERR, 3163 "pid %d (%s), uid (%u): Path `%s' failed " 3164 "on initial open test, error = %d\n", 3165 pid, comm, uid, name, error); 3166 } 3167 goto out; 3168 } 3169 } 3170 3171 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3172 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3173 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3174 out: 3175 if (error) { 3176 #ifdef AUDIT 3177 audit_proc_coredump(td, name, error); 3178 #endif 3179 free(name, M_TEMP); 3180 return (error); 3181 } 3182 NDFREE(&nd, NDF_ONLY_PNBUF); 3183 *vpp = nd.ni_vp; 3184 *namep = name; 3185 return (0); 3186 } 3187 3188 /* 3189 * Dump a process' core. The main routine does some 3190 * policy checking, and creates the name of the coredump; 3191 * then it passes on a vnode and a size limit to the process-specific 3192 * coredump routine if there is one; if there _is not_ one, it returns 3193 * ENOSYS; otherwise it returns the error from the process-specific routine. 3194 */ 3195 3196 static int 3197 coredump(struct thread *td) 3198 { 3199 struct proc *p = td->td_proc; 3200 struct ucred *cred = td->td_ucred; 3201 struct vnode *vp; 3202 struct flock lf; 3203 struct vattr vattr; 3204 int error, error1, locked; 3205 struct mount *mp; 3206 char *name; /* name of corefile */ 3207 off_t limit; 3208 int compress; 3209 3210 #ifdef COMPRESS_USER_CORES 3211 compress = compress_user_cores; 3212 #else 3213 compress = 0; 3214 #endif 3215 PROC_LOCK_ASSERT(p, MA_OWNED); 3216 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3217 _STOPEVENT(p, S_CORE, 0); 3218 3219 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) { 3220 PROC_UNLOCK(p); 3221 return (EFAULT); 3222 } 3223 3224 /* 3225 * Note that the bulk of limit checking is done after 3226 * the corefile is created. The exception is if the limit 3227 * for corefiles is 0, in which case we don't bother 3228 * creating the corefile at all. This layout means that 3229 * a corefile is truncated instead of not being created, 3230 * if it is larger than the limit. 3231 */ 3232 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3233 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3234 PROC_UNLOCK(p); 3235 return (EFBIG); 3236 } 3237 PROC_UNLOCK(p); 3238 3239 restart: 3240 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3241 &vp, &name); 3242 if (error != 0) 3243 return (error); 3244 3245 /* Don't dump to non-regular files or files with links. */ 3246 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3247 vattr.va_nlink != 1) { 3248 VOP_UNLOCK(vp, 0); 3249 error = EFAULT; 3250 goto close; 3251 } 3252 3253 VOP_UNLOCK(vp, 0); 3254 lf.l_whence = SEEK_SET; 3255 lf.l_start = 0; 3256 lf.l_len = 0; 3257 lf.l_type = F_WRLCK; 3258 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3259 3260 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3261 lf.l_type = F_UNLCK; 3262 if (locked) 3263 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3264 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3265 goto out; 3266 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3267 goto out; 3268 free(name, M_TEMP); 3269 goto restart; 3270 } 3271 3272 VATTR_NULL(&vattr); 3273 vattr.va_size = 0; 3274 if (set_core_nodump_flag) 3275 vattr.va_flags = UF_NODUMP; 3276 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3277 VOP_SETATTR(vp, &vattr, cred); 3278 VOP_UNLOCK(vp, 0); 3279 vn_finished_write(mp); 3280 PROC_LOCK(p); 3281 p->p_acflag |= ACORE; 3282 PROC_UNLOCK(p); 3283 3284 if (p->p_sysent->sv_coredump != NULL) { 3285 error = p->p_sysent->sv_coredump(td, vp, limit, 3286 compress ? IMGACT_CORE_COMPRESS : 0); 3287 } else { 3288 error = ENOSYS; 3289 } 3290 3291 if (locked) { 3292 lf.l_type = F_UNLCK; 3293 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3294 } 3295 close: 3296 error1 = vn_close(vp, FWRITE, cred, td); 3297 if (error == 0) 3298 error = error1; 3299 out: 3300 #ifdef AUDIT 3301 audit_proc_coredump(td, name, error); 3302 #endif 3303 free(name, M_TEMP); 3304 return (error); 3305 } 3306 3307 /* 3308 * Nonexistent system call-- signal process (may want to handle it). Flag 3309 * error in case process won't see signal immediately (blocked or ignored). 3310 */ 3311 #ifndef _SYS_SYSPROTO_H_ 3312 struct nosys_args { 3313 int dummy; 3314 }; 3315 #endif 3316 /* ARGSUSED */ 3317 int 3318 nosys(td, args) 3319 struct thread *td; 3320 struct nosys_args *args; 3321 { 3322 struct proc *p = td->td_proc; 3323 3324 PROC_LOCK(p); 3325 tdsignal(td, SIGSYS); 3326 PROC_UNLOCK(p); 3327 return (ENOSYS); 3328 } 3329 3330 /* 3331 * Send a SIGIO or SIGURG signal to a process or process group using stored 3332 * credentials rather than those of the current process. 3333 */ 3334 void 3335 pgsigio(sigiop, sig, checkctty) 3336 struct sigio **sigiop; 3337 int sig, checkctty; 3338 { 3339 ksiginfo_t ksi; 3340 struct sigio *sigio; 3341 3342 ksiginfo_init(&ksi); 3343 ksi.ksi_signo = sig; 3344 ksi.ksi_code = SI_KERNEL; 3345 3346 SIGIO_LOCK(); 3347 sigio = *sigiop; 3348 if (sigio == NULL) { 3349 SIGIO_UNLOCK(); 3350 return; 3351 } 3352 if (sigio->sio_pgid > 0) { 3353 PROC_LOCK(sigio->sio_proc); 3354 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3355 kern_psignal(sigio->sio_proc, sig); 3356 PROC_UNLOCK(sigio->sio_proc); 3357 } else if (sigio->sio_pgid < 0) { 3358 struct proc *p; 3359 3360 PGRP_LOCK(sigio->sio_pgrp); 3361 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3362 PROC_LOCK(p); 3363 if (p->p_state == PRS_NORMAL && 3364 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3365 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3366 kern_psignal(p, sig); 3367 PROC_UNLOCK(p); 3368 } 3369 PGRP_UNLOCK(sigio->sio_pgrp); 3370 } 3371 SIGIO_UNLOCK(); 3372 } 3373 3374 static int 3375 filt_sigattach(struct knote *kn) 3376 { 3377 struct proc *p = curproc; 3378 3379 kn->kn_ptr.p_proc = p; 3380 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3381 3382 knlist_add(&p->p_klist, kn, 0); 3383 3384 return (0); 3385 } 3386 3387 static void 3388 filt_sigdetach(struct knote *kn) 3389 { 3390 struct proc *p = kn->kn_ptr.p_proc; 3391 3392 knlist_remove(&p->p_klist, kn, 0); 3393 } 3394 3395 /* 3396 * signal knotes are shared with proc knotes, so we apply a mask to 3397 * the hint in order to differentiate them from process hints. This 3398 * could be avoided by using a signal-specific knote list, but probably 3399 * isn't worth the trouble. 3400 */ 3401 static int 3402 filt_signal(struct knote *kn, long hint) 3403 { 3404 3405 if (hint & NOTE_SIGNAL) { 3406 hint &= ~NOTE_SIGNAL; 3407 3408 if (kn->kn_id == hint) 3409 kn->kn_data++; 3410 } 3411 return (kn->kn_data != 0); 3412 } 3413 3414 struct sigacts * 3415 sigacts_alloc(void) 3416 { 3417 struct sigacts *ps; 3418 3419 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3420 ps->ps_refcnt = 1; 3421 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3422 return (ps); 3423 } 3424 3425 void 3426 sigacts_free(struct sigacts *ps) 3427 { 3428 3429 mtx_lock(&ps->ps_mtx); 3430 ps->ps_refcnt--; 3431 if (ps->ps_refcnt == 0) { 3432 mtx_destroy(&ps->ps_mtx); 3433 free(ps, M_SUBPROC); 3434 } else 3435 mtx_unlock(&ps->ps_mtx); 3436 } 3437 3438 struct sigacts * 3439 sigacts_hold(struct sigacts *ps) 3440 { 3441 mtx_lock(&ps->ps_mtx); 3442 ps->ps_refcnt++; 3443 mtx_unlock(&ps->ps_mtx); 3444 return (ps); 3445 } 3446 3447 void 3448 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3449 { 3450 3451 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3452 mtx_lock(&src->ps_mtx); 3453 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3454 mtx_unlock(&src->ps_mtx); 3455 } 3456 3457 int 3458 sigacts_shared(struct sigacts *ps) 3459 { 3460 int shared; 3461 3462 mtx_lock(&ps->ps_mtx); 3463 shared = ps->ps_refcnt > 1; 3464 mtx_unlock(&ps->ps_mtx); 3465 return (shared); 3466 } 3467