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