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