Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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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: releng/9.0/sys/kern/kern_sig.c 226199 2011-10-10 12:07:04Z kib $"); 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 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 140 141 static int max_pending_per_proc = 128; 142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 143 &max_pending_per_proc, 0, "Max pending signals per proc"); 144 145 static int preallocate_siginfo = 1024; 146 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 148 &preallocate_siginfo, 0, "Preallocated signal memory size"); 149 150 static int signal_overflow = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 152 &signal_overflow, 0, "Number of signals overflew"); 153 154 static int signal_alloc_fail = 0; 155 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 156 &signal_alloc_fail, 0, "signals failed to be allocated"); 157 158 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160 /* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165 #define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172 static int sugid_coredump; 173 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176 static int do_coredump = 1; 177 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 178 &do_coredump, 0, "Enable/Disable coredumps"); 179 180 static int set_core_nodump_flag = 0; 181 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 182 0, "Enable setting the NODUMP flag on coredump files"); 183 184 /* 185 * Signal properties and actions. 186 * The array below categorizes the signals and their default actions 187 * according to the following properties: 188 */ 189 #define SA_KILL 0x01 /* terminates process by default */ 190 #define SA_CORE 0x02 /* ditto and coredumps */ 191 #define SA_STOP 0x04 /* suspend process */ 192 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 193 #define SA_IGNORE 0x10 /* ignore by default */ 194 #define SA_CONT 0x20 /* continue if suspended */ 195 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 196 #define SA_PROC 0x80 /* deliverable to any thread */ 197 198 static int sigproptbl[NSIG] = { 199 SA_KILL|SA_PROC, /* SIGHUP */ 200 SA_KILL|SA_PROC, /* SIGINT */ 201 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 202 SA_KILL|SA_CORE, /* SIGILL */ 203 SA_KILL|SA_CORE, /* SIGTRAP */ 204 SA_KILL|SA_CORE, /* SIGABRT */ 205 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 206 SA_KILL|SA_CORE, /* SIGFPE */ 207 SA_KILL|SA_PROC, /* SIGKILL */ 208 SA_KILL|SA_CORE, /* SIGBUS */ 209 SA_KILL|SA_CORE, /* SIGSEGV */ 210 SA_KILL|SA_CORE, /* SIGSYS */ 211 SA_KILL|SA_PROC, /* SIGPIPE */ 212 SA_KILL|SA_PROC, /* SIGALRM */ 213 SA_KILL|SA_PROC, /* SIGTERM */ 214 SA_IGNORE|SA_PROC, /* SIGURG */ 215 SA_STOP|SA_PROC, /* SIGSTOP */ 216 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 217 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 218 SA_IGNORE|SA_PROC, /* SIGCHLD */ 219 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 220 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 221 SA_IGNORE|SA_PROC, /* SIGIO */ 222 SA_KILL, /* SIGXCPU */ 223 SA_KILL, /* SIGXFSZ */ 224 SA_KILL|SA_PROC, /* SIGVTALRM */ 225 SA_KILL|SA_PROC, /* SIGPROF */ 226 SA_IGNORE|SA_PROC, /* SIGWINCH */ 227 SA_IGNORE|SA_PROC, /* SIGINFO */ 228 SA_KILL|SA_PROC, /* SIGUSR1 */ 229 SA_KILL|SA_PROC, /* SIGUSR2 */ 230 }; 231 232 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 233 234 static void 235 sigqueue_start(void) 236 { 237 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 238 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 239 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 240 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 241 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 242 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 243 } 244 245 ksiginfo_t * 246 ksiginfo_alloc(int wait) 247 { 248 int flags; 249 250 flags = M_ZERO; 251 if (! wait) 252 flags |= M_NOWAIT; 253 if (ksiginfo_zone != NULL) 254 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 255 return (NULL); 256 } 257 258 void 259 ksiginfo_free(ksiginfo_t *ksi) 260 { 261 uma_zfree(ksiginfo_zone, ksi); 262 } 263 264 static __inline int 265 ksiginfo_tryfree(ksiginfo_t *ksi) 266 { 267 if (!(ksi->ksi_flags & KSI_EXT)) { 268 uma_zfree(ksiginfo_zone, ksi); 269 return (1); 270 } 271 return (0); 272 } 273 274 void 275 sigqueue_init(sigqueue_t *list, struct proc *p) 276 { 277 SIGEMPTYSET(list->sq_signals); 278 SIGEMPTYSET(list->sq_kill); 279 TAILQ_INIT(&list->sq_list); 280 list->sq_proc = p; 281 list->sq_flags = SQ_INIT; 282 } 283 284 /* 285 * Get a signal's ksiginfo. 286 * Return: 287 * 0 - signal not found 288 * others - signal number 289 */ 290 static int 291 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 292 { 293 struct proc *p = sq->sq_proc; 294 struct ksiginfo *ksi, *next; 295 int count = 0; 296 297 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 298 299 if (!SIGISMEMBER(sq->sq_signals, signo)) 300 return (0); 301 302 if (SIGISMEMBER(sq->sq_kill, signo)) { 303 count++; 304 SIGDELSET(sq->sq_kill, signo); 305 } 306 307 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 308 if (ksi->ksi_signo == signo) { 309 if (count == 0) { 310 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 311 ksi->ksi_sigq = NULL; 312 ksiginfo_copy(ksi, si); 313 if (ksiginfo_tryfree(ksi) && p != NULL) 314 p->p_pendingcnt--; 315 } 316 if (++count > 1) 317 break; 318 } 319 } 320 321 if (count <= 1) 322 SIGDELSET(sq->sq_signals, signo); 323 si->ksi_signo = signo; 324 return (signo); 325 } 326 327 void 328 sigqueue_take(ksiginfo_t *ksi) 329 { 330 struct ksiginfo *kp; 331 struct proc *p; 332 sigqueue_t *sq; 333 334 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 335 return; 336 337 p = sq->sq_proc; 338 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 339 ksi->ksi_sigq = NULL; 340 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 341 p->p_pendingcnt--; 342 343 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 344 kp = TAILQ_NEXT(kp, ksi_link)) { 345 if (kp->ksi_signo == ksi->ksi_signo) 346 break; 347 } 348 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 349 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 350 } 351 352 static int 353 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 354 { 355 struct proc *p = sq->sq_proc; 356 struct ksiginfo *ksi; 357 int ret = 0; 358 359 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 360 361 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 362 SIGADDSET(sq->sq_kill, signo); 363 goto out_set_bit; 364 } 365 366 /* directly insert the ksi, don't copy it */ 367 if (si->ksi_flags & KSI_INS) { 368 if (si->ksi_flags & KSI_HEAD) 369 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 370 else 371 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 372 si->ksi_sigq = sq; 373 goto out_set_bit; 374 } 375 376 if (__predict_false(ksiginfo_zone == NULL)) { 377 SIGADDSET(sq->sq_kill, signo); 378 goto out_set_bit; 379 } 380 381 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 382 signal_overflow++; 383 ret = EAGAIN; 384 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 385 signal_alloc_fail++; 386 ret = EAGAIN; 387 } else { 388 if (p != NULL) 389 p->p_pendingcnt++; 390 ksiginfo_copy(si, ksi); 391 ksi->ksi_signo = signo; 392 if (si->ksi_flags & KSI_HEAD) 393 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 394 else 395 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 396 ksi->ksi_sigq = sq; 397 } 398 399 if ((si->ksi_flags & KSI_TRAP) != 0 || 400 (si->ksi_flags & KSI_SIGQ) == 0) { 401 if (ret != 0) 402 SIGADDSET(sq->sq_kill, signo); 403 ret = 0; 404 goto out_set_bit; 405 } 406 407 if (ret != 0) 408 return (ret); 409 410 out_set_bit: 411 SIGADDSET(sq->sq_signals, signo); 412 return (ret); 413 } 414 415 void 416 sigqueue_flush(sigqueue_t *sq) 417 { 418 struct proc *p = sq->sq_proc; 419 ksiginfo_t *ksi; 420 421 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 422 423 if (p != NULL) 424 PROC_LOCK_ASSERT(p, MA_OWNED); 425 426 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 427 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 428 ksi->ksi_sigq = NULL; 429 if (ksiginfo_tryfree(ksi) && p != NULL) 430 p->p_pendingcnt--; 431 } 432 433 SIGEMPTYSET(sq->sq_signals); 434 SIGEMPTYSET(sq->sq_kill); 435 } 436 437 static void 438 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 439 { 440 sigset_t tmp; 441 struct proc *p1, *p2; 442 ksiginfo_t *ksi, *next; 443 444 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 445 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 446 p1 = src->sq_proc; 447 p2 = dst->sq_proc; 448 /* Move siginfo to target list */ 449 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 450 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 451 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 452 if (p1 != NULL) 453 p1->p_pendingcnt--; 454 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 455 ksi->ksi_sigq = dst; 456 if (p2 != NULL) 457 p2->p_pendingcnt++; 458 } 459 } 460 461 /* Move pending bits to target list */ 462 tmp = src->sq_kill; 463 SIGSETAND(tmp, *set); 464 SIGSETOR(dst->sq_kill, tmp); 465 SIGSETNAND(src->sq_kill, tmp); 466 467 tmp = src->sq_signals; 468 SIGSETAND(tmp, *set); 469 SIGSETOR(dst->sq_signals, tmp); 470 SIGSETNAND(src->sq_signals, tmp); 471 } 472 473 #if 0 474 static void 475 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 476 { 477 sigset_t set; 478 479 SIGEMPTYSET(set); 480 SIGADDSET(set, signo); 481 sigqueue_move_set(src, dst, &set); 482 } 483 #endif 484 485 static void 486 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 487 { 488 struct proc *p = sq->sq_proc; 489 ksiginfo_t *ksi, *next; 490 491 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 492 493 /* Remove siginfo queue */ 494 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 495 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 496 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 497 ksi->ksi_sigq = NULL; 498 if (ksiginfo_tryfree(ksi) && p != NULL) 499 p->p_pendingcnt--; 500 } 501 } 502 SIGSETNAND(sq->sq_kill, *set); 503 SIGSETNAND(sq->sq_signals, *set); 504 } 505 506 void 507 sigqueue_delete(sigqueue_t *sq, int signo) 508 { 509 sigset_t set; 510 511 SIGEMPTYSET(set); 512 SIGADDSET(set, signo); 513 sigqueue_delete_set(sq, &set); 514 } 515 516 /* Remove a set of signals for a process */ 517 static void 518 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 519 { 520 sigqueue_t worklist; 521 struct thread *td0; 522 523 PROC_LOCK_ASSERT(p, MA_OWNED); 524 525 sigqueue_init(&worklist, NULL); 526 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 527 528 FOREACH_THREAD_IN_PROC(p, td0) 529 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 530 531 sigqueue_flush(&worklist); 532 } 533 534 void 535 sigqueue_delete_proc(struct proc *p, int signo) 536 { 537 sigset_t set; 538 539 SIGEMPTYSET(set); 540 SIGADDSET(set, signo); 541 sigqueue_delete_set_proc(p, &set); 542 } 543 544 static void 545 sigqueue_delete_stopmask_proc(struct proc *p) 546 { 547 sigset_t set; 548 549 SIGEMPTYSET(set); 550 SIGADDSET(set, SIGSTOP); 551 SIGADDSET(set, SIGTSTP); 552 SIGADDSET(set, SIGTTIN); 553 SIGADDSET(set, SIGTTOU); 554 sigqueue_delete_set_proc(p, &set); 555 } 556 557 /* 558 * Determine signal that should be delivered to process p, the current 559 * process, 0 if none. If there is a pending stop signal with default 560 * action, the process stops in issignal(). 561 */ 562 int 563 cursig(struct thread *td, int stop_allowed) 564 { 565 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 566 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 567 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 568 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 569 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 570 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 571 } 572 573 /* 574 * Arrange for ast() to handle unmasked pending signals on return to user 575 * mode. This must be called whenever a signal is added to td_sigqueue or 576 * unmasked in td_sigmask. 577 */ 578 void 579 signotify(struct thread *td) 580 { 581 struct proc *p; 582 583 p = td->td_proc; 584 585 PROC_LOCK_ASSERT(p, MA_OWNED); 586 587 if (SIGPENDING(td)) { 588 thread_lock(td); 589 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 590 thread_unlock(td); 591 } 592 } 593 594 int 595 sigonstack(size_t sp) 596 { 597 struct thread *td = curthread; 598 599 return ((td->td_pflags & TDP_ALTSTACK) ? 600 #if defined(COMPAT_43) 601 ((td->td_sigstk.ss_size == 0) ? 602 (td->td_sigstk.ss_flags & SS_ONSTACK) : 603 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 604 #else 605 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 606 #endif 607 : 0); 608 } 609 610 static __inline int 611 sigprop(int sig) 612 { 613 614 if (sig > 0 && sig < NSIG) 615 return (sigproptbl[_SIG_IDX(sig)]); 616 return (0); 617 } 618 619 int 620 sig_ffs(sigset_t *set) 621 { 622 int i; 623 624 for (i = 0; i < _SIG_WORDS; i++) 625 if (set->__bits[i]) 626 return (ffs(set->__bits[i]) + (i * 32)); 627 return (0); 628 } 629 630 /* 631 * kern_sigaction 632 * sigaction 633 * freebsd4_sigaction 634 * osigaction 635 */ 636 int 637 kern_sigaction(td, sig, act, oact, flags) 638 struct thread *td; 639 register int sig; 640 struct sigaction *act, *oact; 641 int flags; 642 { 643 struct sigacts *ps; 644 struct proc *p = td->td_proc; 645 646 if (!_SIG_VALID(sig)) 647 return (EINVAL); 648 649 PROC_LOCK(p); 650 ps = p->p_sigacts; 651 mtx_lock(&ps->ps_mtx); 652 if (oact) { 653 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 654 oact->sa_flags = 0; 655 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 656 oact->sa_flags |= SA_ONSTACK; 657 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 658 oact->sa_flags |= SA_RESTART; 659 if (SIGISMEMBER(ps->ps_sigreset, sig)) 660 oact->sa_flags |= SA_RESETHAND; 661 if (SIGISMEMBER(ps->ps_signodefer, sig)) 662 oact->sa_flags |= SA_NODEFER; 663 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 664 oact->sa_flags |= SA_SIGINFO; 665 oact->sa_sigaction = 666 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 667 } else 668 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 669 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 670 oact->sa_flags |= SA_NOCLDSTOP; 671 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 672 oact->sa_flags |= SA_NOCLDWAIT; 673 } 674 if (act) { 675 if ((sig == SIGKILL || sig == SIGSTOP) && 676 act->sa_handler != SIG_DFL) { 677 mtx_unlock(&ps->ps_mtx); 678 PROC_UNLOCK(p); 679 return (EINVAL); 680 } 681 682 /* 683 * Change setting atomically. 684 */ 685 686 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 687 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 688 if (act->sa_flags & SA_SIGINFO) { 689 ps->ps_sigact[_SIG_IDX(sig)] = 690 (__sighandler_t *)act->sa_sigaction; 691 SIGADDSET(ps->ps_siginfo, sig); 692 } else { 693 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 694 SIGDELSET(ps->ps_siginfo, sig); 695 } 696 if (!(act->sa_flags & SA_RESTART)) 697 SIGADDSET(ps->ps_sigintr, sig); 698 else 699 SIGDELSET(ps->ps_sigintr, sig); 700 if (act->sa_flags & SA_ONSTACK) 701 SIGADDSET(ps->ps_sigonstack, sig); 702 else 703 SIGDELSET(ps->ps_sigonstack, sig); 704 if (act->sa_flags & SA_RESETHAND) 705 SIGADDSET(ps->ps_sigreset, sig); 706 else 707 SIGDELSET(ps->ps_sigreset, sig); 708 if (act->sa_flags & SA_NODEFER) 709 SIGADDSET(ps->ps_signodefer, sig); 710 else 711 SIGDELSET(ps->ps_signodefer, sig); 712 if (sig == SIGCHLD) { 713 if (act->sa_flags & SA_NOCLDSTOP) 714 ps->ps_flag |= PS_NOCLDSTOP; 715 else 716 ps->ps_flag &= ~PS_NOCLDSTOP; 717 if (act->sa_flags & SA_NOCLDWAIT) { 718 /* 719 * Paranoia: since SA_NOCLDWAIT is implemented 720 * by reparenting the dying child to PID 1 (and 721 * trust it to reap the zombie), PID 1 itself 722 * is forbidden to set SA_NOCLDWAIT. 723 */ 724 if (p->p_pid == 1) 725 ps->ps_flag &= ~PS_NOCLDWAIT; 726 else 727 ps->ps_flag |= PS_NOCLDWAIT; 728 } else 729 ps->ps_flag &= ~PS_NOCLDWAIT; 730 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 731 ps->ps_flag |= PS_CLDSIGIGN; 732 else 733 ps->ps_flag &= ~PS_CLDSIGIGN; 734 } 735 /* 736 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 737 * and for signals set to SIG_DFL where the default is to 738 * ignore. However, don't put SIGCONT in ps_sigignore, as we 739 * have to restart the process. 740 */ 741 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 742 (sigprop(sig) & SA_IGNORE && 743 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 744 /* never to be seen again */ 745 sigqueue_delete_proc(p, sig); 746 if (sig != SIGCONT) 747 /* easier in psignal */ 748 SIGADDSET(ps->ps_sigignore, sig); 749 SIGDELSET(ps->ps_sigcatch, sig); 750 } else { 751 SIGDELSET(ps->ps_sigignore, sig); 752 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 753 SIGDELSET(ps->ps_sigcatch, sig); 754 else 755 SIGADDSET(ps->ps_sigcatch, sig); 756 } 757 #ifdef COMPAT_FREEBSD4 758 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 759 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 760 (flags & KSA_FREEBSD4) == 0) 761 SIGDELSET(ps->ps_freebsd4, sig); 762 else 763 SIGADDSET(ps->ps_freebsd4, sig); 764 #endif 765 #ifdef COMPAT_43 766 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 767 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 768 (flags & KSA_OSIGSET) == 0) 769 SIGDELSET(ps->ps_osigset, sig); 770 else 771 SIGADDSET(ps->ps_osigset, sig); 772 #endif 773 } 774 mtx_unlock(&ps->ps_mtx); 775 PROC_UNLOCK(p); 776 return (0); 777 } 778 779 #ifndef _SYS_SYSPROTO_H_ 780 struct sigaction_args { 781 int sig; 782 struct sigaction *act; 783 struct sigaction *oact; 784 }; 785 #endif 786 int 787 sys_sigaction(td, uap) 788 struct thread *td; 789 register struct sigaction_args *uap; 790 { 791 struct sigaction act, oact; 792 register struct sigaction *actp, *oactp; 793 int error; 794 795 actp = (uap->act != NULL) ? &act : NULL; 796 oactp = (uap->oact != NULL) ? &oact : NULL; 797 if (actp) { 798 error = copyin(uap->act, actp, sizeof(act)); 799 if (error) 800 return (error); 801 } 802 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 803 if (oactp && !error) 804 error = copyout(oactp, uap->oact, sizeof(oact)); 805 return (error); 806 } 807 808 #ifdef COMPAT_FREEBSD4 809 #ifndef _SYS_SYSPROTO_H_ 810 struct freebsd4_sigaction_args { 811 int sig; 812 struct sigaction *act; 813 struct sigaction *oact; 814 }; 815 #endif 816 int 817 freebsd4_sigaction(td, uap) 818 struct thread *td; 819 register struct freebsd4_sigaction_args *uap; 820 { 821 struct sigaction act, oact; 822 register struct sigaction *actp, *oactp; 823 int error; 824 825 826 actp = (uap->act != NULL) ? &act : NULL; 827 oactp = (uap->oact != NULL) ? &oact : NULL; 828 if (actp) { 829 error = copyin(uap->act, actp, sizeof(act)); 830 if (error) 831 return (error); 832 } 833 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 834 if (oactp && !error) 835 error = copyout(oactp, uap->oact, sizeof(oact)); 836 return (error); 837 } 838 #endif /* COMAPT_FREEBSD4 */ 839 840 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 841 #ifndef _SYS_SYSPROTO_H_ 842 struct osigaction_args { 843 int signum; 844 struct osigaction *nsa; 845 struct osigaction *osa; 846 }; 847 #endif 848 int 849 osigaction(td, uap) 850 struct thread *td; 851 register struct osigaction_args *uap; 852 { 853 struct osigaction sa; 854 struct sigaction nsa, osa; 855 register struct sigaction *nsap, *osap; 856 int error; 857 858 if (uap->signum <= 0 || uap->signum >= ONSIG) 859 return (EINVAL); 860 861 nsap = (uap->nsa != NULL) ? &nsa : NULL; 862 osap = (uap->osa != NULL) ? &osa : NULL; 863 864 if (nsap) { 865 error = copyin(uap->nsa, &sa, sizeof(sa)); 866 if (error) 867 return (error); 868 nsap->sa_handler = sa.sa_handler; 869 nsap->sa_flags = sa.sa_flags; 870 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 871 } 872 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 873 if (osap && !error) { 874 sa.sa_handler = osap->sa_handler; 875 sa.sa_flags = osap->sa_flags; 876 SIG2OSIG(osap->sa_mask, sa.sa_mask); 877 error = copyout(&sa, uap->osa, sizeof(sa)); 878 } 879 return (error); 880 } 881 882 #if !defined(__i386__) 883 /* Avoid replicating the same stub everywhere */ 884 int 885 osigreturn(td, uap) 886 struct thread *td; 887 struct osigreturn_args *uap; 888 { 889 890 return (nosys(td, (struct nosys_args *)uap)); 891 } 892 #endif 893 #endif /* COMPAT_43 */ 894 895 /* 896 * Initialize signal state for process 0; 897 * set to ignore signals that are ignored by default. 898 */ 899 void 900 siginit(p) 901 struct proc *p; 902 { 903 register int i; 904 struct sigacts *ps; 905 906 PROC_LOCK(p); 907 ps = p->p_sigacts; 908 mtx_lock(&ps->ps_mtx); 909 for (i = 1; i <= NSIG; i++) 910 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 911 SIGADDSET(ps->ps_sigignore, i); 912 mtx_unlock(&ps->ps_mtx); 913 PROC_UNLOCK(p); 914 } 915 916 /* 917 * Reset signals for an exec of the specified process. 918 */ 919 void 920 execsigs(struct proc *p) 921 { 922 struct sigacts *ps; 923 int sig; 924 struct thread *td; 925 926 /* 927 * Reset caught signals. Held signals remain held 928 * through td_sigmask (unless they were caught, 929 * and are now ignored by default). 930 */ 931 PROC_LOCK_ASSERT(p, MA_OWNED); 932 td = FIRST_THREAD_IN_PROC(p); 933 ps = p->p_sigacts; 934 mtx_lock(&ps->ps_mtx); 935 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 936 sig = sig_ffs(&ps->ps_sigcatch); 937 SIGDELSET(ps->ps_sigcatch, sig); 938 if (sigprop(sig) & SA_IGNORE) { 939 if (sig != SIGCONT) 940 SIGADDSET(ps->ps_sigignore, sig); 941 sigqueue_delete_proc(p, sig); 942 } 943 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 944 } 945 /* 946 * Reset stack state to the user stack. 947 * Clear set of signals caught on the signal stack. 948 */ 949 td->td_sigstk.ss_flags = SS_DISABLE; 950 td->td_sigstk.ss_size = 0; 951 td->td_sigstk.ss_sp = 0; 952 td->td_pflags &= ~TDP_ALTSTACK; 953 /* 954 * Reset no zombies if child dies flag as Solaris does. 955 */ 956 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 957 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 958 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 959 mtx_unlock(&ps->ps_mtx); 960 } 961 962 /* 963 * kern_sigprocmask() 964 * 965 * Manipulate signal mask. 966 */ 967 int 968 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 969 int flags) 970 { 971 sigset_t new_block, oset1; 972 struct proc *p; 973 int error; 974 975 p = td->td_proc; 976 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 977 PROC_LOCK(p); 978 if (oset != NULL) 979 *oset = td->td_sigmask; 980 981 error = 0; 982 if (set != NULL) { 983 switch (how) { 984 case SIG_BLOCK: 985 SIG_CANTMASK(*set); 986 oset1 = td->td_sigmask; 987 SIGSETOR(td->td_sigmask, *set); 988 new_block = td->td_sigmask; 989 SIGSETNAND(new_block, oset1); 990 break; 991 case SIG_UNBLOCK: 992 SIGSETNAND(td->td_sigmask, *set); 993 signotify(td); 994 goto out; 995 case SIG_SETMASK: 996 SIG_CANTMASK(*set); 997 oset1 = td->td_sigmask; 998 if (flags & SIGPROCMASK_OLD) 999 SIGSETLO(td->td_sigmask, *set); 1000 else 1001 td->td_sigmask = *set; 1002 new_block = td->td_sigmask; 1003 SIGSETNAND(new_block, oset1); 1004 signotify(td); 1005 break; 1006 default: 1007 error = EINVAL; 1008 goto out; 1009 } 1010 1011 /* 1012 * The new_block set contains signals that were not previously 1013 * blocked, but are blocked now. 1014 * 1015 * In case we block any signal that was not previously blocked 1016 * for td, and process has the signal pending, try to schedule 1017 * signal delivery to some thread that does not block the 1018 * signal, possibly waking it up. 1019 */ 1020 if (p->p_numthreads != 1) 1021 reschedule_signals(p, new_block, flags); 1022 } 1023 1024 out: 1025 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1026 PROC_UNLOCK(p); 1027 return (error); 1028 } 1029 1030 #ifndef _SYS_SYSPROTO_H_ 1031 struct sigprocmask_args { 1032 int how; 1033 const sigset_t *set; 1034 sigset_t *oset; 1035 }; 1036 #endif 1037 int 1038 sys_sigprocmask(td, uap) 1039 register struct thread *td; 1040 struct sigprocmask_args *uap; 1041 { 1042 sigset_t set, oset; 1043 sigset_t *setp, *osetp; 1044 int error; 1045 1046 setp = (uap->set != NULL) ? &set : NULL; 1047 osetp = (uap->oset != NULL) ? &oset : NULL; 1048 if (setp) { 1049 error = copyin(uap->set, setp, sizeof(set)); 1050 if (error) 1051 return (error); 1052 } 1053 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1054 if (osetp && !error) { 1055 error = copyout(osetp, uap->oset, sizeof(oset)); 1056 } 1057 return (error); 1058 } 1059 1060 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1061 #ifndef _SYS_SYSPROTO_H_ 1062 struct osigprocmask_args { 1063 int how; 1064 osigset_t mask; 1065 }; 1066 #endif 1067 int 1068 osigprocmask(td, uap) 1069 register struct thread *td; 1070 struct osigprocmask_args *uap; 1071 { 1072 sigset_t set, oset; 1073 int error; 1074 1075 OSIG2SIG(uap->mask, set); 1076 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1077 SIG2OSIG(oset, td->td_retval[0]); 1078 return (error); 1079 } 1080 #endif /* COMPAT_43 */ 1081 1082 int 1083 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1084 { 1085 ksiginfo_t ksi; 1086 sigset_t set; 1087 int error; 1088 1089 error = copyin(uap->set, &set, sizeof(set)); 1090 if (error) { 1091 td->td_retval[0] = error; 1092 return (0); 1093 } 1094 1095 error = kern_sigtimedwait(td, set, &ksi, NULL); 1096 if (error) { 1097 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1098 error = ERESTART; 1099 if (error == ERESTART) 1100 return (error); 1101 td->td_retval[0] = error; 1102 return (0); 1103 } 1104 1105 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1106 td->td_retval[0] = error; 1107 return (0); 1108 } 1109 1110 int 1111 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1112 { 1113 struct timespec ts; 1114 struct timespec *timeout; 1115 sigset_t set; 1116 ksiginfo_t ksi; 1117 int error; 1118 1119 if (uap->timeout) { 1120 error = copyin(uap->timeout, &ts, sizeof(ts)); 1121 if (error) 1122 return (error); 1123 1124 timeout = &ts; 1125 } else 1126 timeout = NULL; 1127 1128 error = copyin(uap->set, &set, sizeof(set)); 1129 if (error) 1130 return (error); 1131 1132 error = kern_sigtimedwait(td, set, &ksi, timeout); 1133 if (error) 1134 return (error); 1135 1136 if (uap->info) 1137 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1138 1139 if (error == 0) 1140 td->td_retval[0] = ksi.ksi_signo; 1141 return (error); 1142 } 1143 1144 int 1145 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1146 { 1147 ksiginfo_t ksi; 1148 sigset_t set; 1149 int error; 1150 1151 error = copyin(uap->set, &set, sizeof(set)); 1152 if (error) 1153 return (error); 1154 1155 error = kern_sigtimedwait(td, set, &ksi, NULL); 1156 if (error) 1157 return (error); 1158 1159 if (uap->info) 1160 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1161 1162 if (error == 0) 1163 td->td_retval[0] = ksi.ksi_signo; 1164 return (error); 1165 } 1166 1167 int 1168 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1169 struct timespec *timeout) 1170 { 1171 struct sigacts *ps; 1172 sigset_t saved_mask, new_block; 1173 struct proc *p; 1174 int error, sig, timo, timevalid = 0; 1175 struct timespec rts, ets, ts; 1176 struct timeval tv; 1177 1178 p = td->td_proc; 1179 error = 0; 1180 ets.tv_sec = 0; 1181 ets.tv_nsec = 0; 1182 1183 if (timeout != NULL) { 1184 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1185 timevalid = 1; 1186 getnanouptime(&rts); 1187 ets = rts; 1188 timespecadd(&ets, timeout); 1189 } 1190 } 1191 ksiginfo_init(ksi); 1192 /* Some signals can not be waited for. */ 1193 SIG_CANTMASK(waitset); 1194 ps = p->p_sigacts; 1195 PROC_LOCK(p); 1196 saved_mask = td->td_sigmask; 1197 SIGSETNAND(td->td_sigmask, waitset); 1198 for (;;) { 1199 mtx_lock(&ps->ps_mtx); 1200 sig = cursig(td, SIG_STOP_ALLOWED); 1201 mtx_unlock(&ps->ps_mtx); 1202 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1203 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1204 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1205 error = 0; 1206 break; 1207 } 1208 } 1209 1210 if (error != 0) 1211 break; 1212 1213 /* 1214 * POSIX says this must be checked after looking for pending 1215 * signals. 1216 */ 1217 if (timeout != NULL) { 1218 if (!timevalid) { 1219 error = EINVAL; 1220 break; 1221 } 1222 getnanouptime(&rts); 1223 if (timespeccmp(&rts, &ets, >=)) { 1224 error = EAGAIN; 1225 break; 1226 } 1227 ts = ets; 1228 timespecsub(&ts, &rts); 1229 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1230 timo = tvtohz(&tv); 1231 } else { 1232 timo = 0; 1233 } 1234 1235 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1236 1237 if (timeout != NULL) { 1238 if (error == ERESTART) { 1239 /* Timeout can not be restarted. */ 1240 error = EINTR; 1241 } else if (error == EAGAIN) { 1242 /* We will calculate timeout by ourself. */ 1243 error = 0; 1244 } 1245 } 1246 } 1247 1248 new_block = saved_mask; 1249 SIGSETNAND(new_block, td->td_sigmask); 1250 td->td_sigmask = saved_mask; 1251 /* 1252 * Fewer signals can be delivered to us, reschedule signal 1253 * notification. 1254 */ 1255 if (p->p_numthreads != 1) 1256 reschedule_signals(p, new_block, 0); 1257 1258 if (error == 0) { 1259 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1260 1261 if (ksi->ksi_code == SI_TIMER) 1262 itimer_accept(p, ksi->ksi_timerid, ksi); 1263 1264 #ifdef KTRACE 1265 if (KTRPOINT(td, KTR_PSIG)) { 1266 sig_t action; 1267 1268 mtx_lock(&ps->ps_mtx); 1269 action = ps->ps_sigact[_SIG_IDX(sig)]; 1270 mtx_unlock(&ps->ps_mtx); 1271 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1272 } 1273 #endif 1274 if (sig == SIGKILL) 1275 sigexit(td, sig); 1276 } 1277 PROC_UNLOCK(p); 1278 return (error); 1279 } 1280 1281 #ifndef _SYS_SYSPROTO_H_ 1282 struct sigpending_args { 1283 sigset_t *set; 1284 }; 1285 #endif 1286 int 1287 sys_sigpending(td, uap) 1288 struct thread *td; 1289 struct sigpending_args *uap; 1290 { 1291 struct proc *p = td->td_proc; 1292 sigset_t pending; 1293 1294 PROC_LOCK(p); 1295 pending = p->p_sigqueue.sq_signals; 1296 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1297 PROC_UNLOCK(p); 1298 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1299 } 1300 1301 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1302 #ifndef _SYS_SYSPROTO_H_ 1303 struct osigpending_args { 1304 int dummy; 1305 }; 1306 #endif 1307 int 1308 osigpending(td, uap) 1309 struct thread *td; 1310 struct osigpending_args *uap; 1311 { 1312 struct proc *p = td->td_proc; 1313 sigset_t pending; 1314 1315 PROC_LOCK(p); 1316 pending = p->p_sigqueue.sq_signals; 1317 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1318 PROC_UNLOCK(p); 1319 SIG2OSIG(pending, td->td_retval[0]); 1320 return (0); 1321 } 1322 #endif /* COMPAT_43 */ 1323 1324 #if defined(COMPAT_43) 1325 /* 1326 * Generalized interface signal handler, 4.3-compatible. 1327 */ 1328 #ifndef _SYS_SYSPROTO_H_ 1329 struct osigvec_args { 1330 int signum; 1331 struct sigvec *nsv; 1332 struct sigvec *osv; 1333 }; 1334 #endif 1335 /* ARGSUSED */ 1336 int 1337 osigvec(td, uap) 1338 struct thread *td; 1339 register struct osigvec_args *uap; 1340 { 1341 struct sigvec vec; 1342 struct sigaction nsa, osa; 1343 register struct sigaction *nsap, *osap; 1344 int error; 1345 1346 if (uap->signum <= 0 || uap->signum >= ONSIG) 1347 return (EINVAL); 1348 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1349 osap = (uap->osv != NULL) ? &osa : NULL; 1350 if (nsap) { 1351 error = copyin(uap->nsv, &vec, sizeof(vec)); 1352 if (error) 1353 return (error); 1354 nsap->sa_handler = vec.sv_handler; 1355 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1356 nsap->sa_flags = vec.sv_flags; 1357 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1358 } 1359 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1360 if (osap && !error) { 1361 vec.sv_handler = osap->sa_handler; 1362 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1363 vec.sv_flags = osap->sa_flags; 1364 vec.sv_flags &= ~SA_NOCLDWAIT; 1365 vec.sv_flags ^= SA_RESTART; 1366 error = copyout(&vec, uap->osv, sizeof(vec)); 1367 } 1368 return (error); 1369 } 1370 1371 #ifndef _SYS_SYSPROTO_H_ 1372 struct osigblock_args { 1373 int mask; 1374 }; 1375 #endif 1376 int 1377 osigblock(td, uap) 1378 register struct thread *td; 1379 struct osigblock_args *uap; 1380 { 1381 sigset_t set, oset; 1382 1383 OSIG2SIG(uap->mask, set); 1384 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1385 SIG2OSIG(oset, td->td_retval[0]); 1386 return (0); 1387 } 1388 1389 #ifndef _SYS_SYSPROTO_H_ 1390 struct osigsetmask_args { 1391 int mask; 1392 }; 1393 #endif 1394 int 1395 osigsetmask(td, uap) 1396 struct thread *td; 1397 struct osigsetmask_args *uap; 1398 { 1399 sigset_t set, oset; 1400 1401 OSIG2SIG(uap->mask, set); 1402 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1403 SIG2OSIG(oset, td->td_retval[0]); 1404 return (0); 1405 } 1406 #endif /* COMPAT_43 */ 1407 1408 /* 1409 * Suspend calling thread until signal, providing mask to be set in the 1410 * meantime. 1411 */ 1412 #ifndef _SYS_SYSPROTO_H_ 1413 struct sigsuspend_args { 1414 const sigset_t *sigmask; 1415 }; 1416 #endif 1417 /* ARGSUSED */ 1418 int 1419 sys_sigsuspend(td, uap) 1420 struct thread *td; 1421 struct sigsuspend_args *uap; 1422 { 1423 sigset_t mask; 1424 int error; 1425 1426 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1427 if (error) 1428 return (error); 1429 return (kern_sigsuspend(td, mask)); 1430 } 1431 1432 int 1433 kern_sigsuspend(struct thread *td, sigset_t mask) 1434 { 1435 struct proc *p = td->td_proc; 1436 int has_sig, sig; 1437 1438 /* 1439 * When returning from sigsuspend, we want 1440 * the old mask to be restored after the 1441 * signal handler has finished. Thus, we 1442 * save it here and mark the sigacts structure 1443 * to indicate this. 1444 */ 1445 PROC_LOCK(p); 1446 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1447 SIGPROCMASK_PROC_LOCKED); 1448 td->td_pflags |= TDP_OLDMASK; 1449 1450 /* 1451 * Process signals now. Otherwise, we can get spurious wakeup 1452 * due to signal entered process queue, but delivered to other 1453 * thread. But sigsuspend should return only on signal 1454 * delivery. 1455 */ 1456 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1457 for (has_sig = 0; !has_sig;) { 1458 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1459 0) == 0) 1460 /* void */; 1461 thread_suspend_check(0); 1462 mtx_lock(&p->p_sigacts->ps_mtx); 1463 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1464 has_sig += postsig(sig); 1465 mtx_unlock(&p->p_sigacts->ps_mtx); 1466 } 1467 PROC_UNLOCK(p); 1468 return (EJUSTRETURN); 1469 } 1470 1471 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1472 /* 1473 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1474 * convention: libc stub passes mask, not pointer, to save a copyin. 1475 */ 1476 #ifndef _SYS_SYSPROTO_H_ 1477 struct osigsuspend_args { 1478 osigset_t mask; 1479 }; 1480 #endif 1481 /* ARGSUSED */ 1482 int 1483 osigsuspend(td, uap) 1484 struct thread *td; 1485 struct osigsuspend_args *uap; 1486 { 1487 sigset_t mask; 1488 1489 OSIG2SIG(uap->mask, mask); 1490 return (kern_sigsuspend(td, mask)); 1491 } 1492 #endif /* COMPAT_43 */ 1493 1494 #if defined(COMPAT_43) 1495 #ifndef _SYS_SYSPROTO_H_ 1496 struct osigstack_args { 1497 struct sigstack *nss; 1498 struct sigstack *oss; 1499 }; 1500 #endif 1501 /* ARGSUSED */ 1502 int 1503 osigstack(td, uap) 1504 struct thread *td; 1505 register struct osigstack_args *uap; 1506 { 1507 struct sigstack nss, oss; 1508 int error = 0; 1509 1510 if (uap->nss != NULL) { 1511 error = copyin(uap->nss, &nss, sizeof(nss)); 1512 if (error) 1513 return (error); 1514 } 1515 oss.ss_sp = td->td_sigstk.ss_sp; 1516 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1517 if (uap->nss != NULL) { 1518 td->td_sigstk.ss_sp = nss.ss_sp; 1519 td->td_sigstk.ss_size = 0; 1520 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1521 td->td_pflags |= TDP_ALTSTACK; 1522 } 1523 if (uap->oss != NULL) 1524 error = copyout(&oss, uap->oss, sizeof(oss)); 1525 1526 return (error); 1527 } 1528 #endif /* COMPAT_43 */ 1529 1530 #ifndef _SYS_SYSPROTO_H_ 1531 struct sigaltstack_args { 1532 stack_t *ss; 1533 stack_t *oss; 1534 }; 1535 #endif 1536 /* ARGSUSED */ 1537 int 1538 sys_sigaltstack(td, uap) 1539 struct thread *td; 1540 register struct sigaltstack_args *uap; 1541 { 1542 stack_t ss, oss; 1543 int error; 1544 1545 if (uap->ss != NULL) { 1546 error = copyin(uap->ss, &ss, sizeof(ss)); 1547 if (error) 1548 return (error); 1549 } 1550 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1551 (uap->oss != NULL) ? &oss : NULL); 1552 if (error) 1553 return (error); 1554 if (uap->oss != NULL) 1555 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1556 return (error); 1557 } 1558 1559 int 1560 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1561 { 1562 struct proc *p = td->td_proc; 1563 int oonstack; 1564 1565 oonstack = sigonstack(cpu_getstack(td)); 1566 1567 if (oss != NULL) { 1568 *oss = td->td_sigstk; 1569 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1570 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1571 } 1572 1573 if (ss != NULL) { 1574 if (oonstack) 1575 return (EPERM); 1576 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1577 return (EINVAL); 1578 if (!(ss->ss_flags & SS_DISABLE)) { 1579 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1580 return (ENOMEM); 1581 1582 td->td_sigstk = *ss; 1583 td->td_pflags |= TDP_ALTSTACK; 1584 } else { 1585 td->td_pflags &= ~TDP_ALTSTACK; 1586 } 1587 } 1588 return (0); 1589 } 1590 1591 /* 1592 * Common code for kill process group/broadcast kill. 1593 * cp is calling process. 1594 */ 1595 static int 1596 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1597 { 1598 struct proc *p; 1599 struct pgrp *pgrp; 1600 int nfound = 0; 1601 1602 if (all) { 1603 /* 1604 * broadcast 1605 */ 1606 sx_slock(&allproc_lock); 1607 FOREACH_PROC_IN_SYSTEM(p) { 1608 PROC_LOCK(p); 1609 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1610 p == td->td_proc || p->p_state == PRS_NEW) { 1611 PROC_UNLOCK(p); 1612 continue; 1613 } 1614 if (p_cansignal(td, p, sig) == 0) { 1615 nfound++; 1616 if (sig) 1617 pksignal(p, sig, ksi); 1618 } 1619 PROC_UNLOCK(p); 1620 } 1621 sx_sunlock(&allproc_lock); 1622 } else { 1623 sx_slock(&proctree_lock); 1624 if (pgid == 0) { 1625 /* 1626 * zero pgid means send to my process group. 1627 */ 1628 pgrp = td->td_proc->p_pgrp; 1629 PGRP_LOCK(pgrp); 1630 } else { 1631 pgrp = pgfind(pgid); 1632 if (pgrp == NULL) { 1633 sx_sunlock(&proctree_lock); 1634 return (ESRCH); 1635 } 1636 } 1637 sx_sunlock(&proctree_lock); 1638 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1639 PROC_LOCK(p); 1640 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1641 p->p_state == PRS_NEW) { 1642 PROC_UNLOCK(p); 1643 continue; 1644 } 1645 if (p_cansignal(td, p, sig) == 0) { 1646 nfound++; 1647 if (sig) 1648 pksignal(p, sig, ksi); 1649 } 1650 PROC_UNLOCK(p); 1651 } 1652 PGRP_UNLOCK(pgrp); 1653 } 1654 return (nfound ? 0 : ESRCH); 1655 } 1656 1657 #ifndef _SYS_SYSPROTO_H_ 1658 struct kill_args { 1659 int pid; 1660 int signum; 1661 }; 1662 #endif 1663 /* ARGSUSED */ 1664 int 1665 sys_kill(struct thread *td, struct kill_args *uap) 1666 { 1667 ksiginfo_t ksi; 1668 struct proc *p; 1669 int error; 1670 1671 AUDIT_ARG_SIGNUM(uap->signum); 1672 AUDIT_ARG_PID(uap->pid); 1673 if ((u_int)uap->signum > _SIG_MAXSIG) 1674 return (EINVAL); 1675 1676 ksiginfo_init(&ksi); 1677 ksi.ksi_signo = uap->signum; 1678 ksi.ksi_code = SI_USER; 1679 ksi.ksi_pid = td->td_proc->p_pid; 1680 ksi.ksi_uid = td->td_ucred->cr_ruid; 1681 1682 if (uap->pid > 0) { 1683 /* kill single process */ 1684 if ((p = pfind(uap->pid)) == NULL) { 1685 if ((p = zpfind(uap->pid)) == NULL) 1686 return (ESRCH); 1687 } 1688 AUDIT_ARG_PROCESS(p); 1689 error = p_cansignal(td, p, uap->signum); 1690 if (error == 0 && uap->signum) 1691 pksignal(p, uap->signum, &ksi); 1692 PROC_UNLOCK(p); 1693 return (error); 1694 } 1695 switch (uap->pid) { 1696 case -1: /* broadcast signal */ 1697 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1698 case 0: /* signal own process group */ 1699 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1700 default: /* negative explicit process group */ 1701 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1702 } 1703 /* NOTREACHED */ 1704 } 1705 1706 int 1707 sys_pdkill(td, uap) 1708 struct thread *td; 1709 struct pdkill_args *uap; 1710 { 1711 #ifdef PROCDESC 1712 struct proc *p; 1713 int error; 1714 1715 AUDIT_ARG_SIGNUM(uap->signum); 1716 AUDIT_ARG_FD(uap->fd); 1717 if ((u_int)uap->signum > _SIG_MAXSIG) 1718 return (EINVAL); 1719 1720 error = procdesc_find(td, uap->fd, CAP_PDKILL, &p); 1721 if (error) 1722 return (error); 1723 AUDIT_ARG_PROCESS(p); 1724 error = p_cansignal(td, p, uap->signum); 1725 if (error == 0 && uap->signum) 1726 kern_psignal(p, uap->signum); 1727 PROC_UNLOCK(p); 1728 return (error); 1729 #else 1730 return (ENOSYS); 1731 #endif 1732 } 1733 1734 #if defined(COMPAT_43) 1735 #ifndef _SYS_SYSPROTO_H_ 1736 struct okillpg_args { 1737 int pgid; 1738 int signum; 1739 }; 1740 #endif 1741 /* ARGSUSED */ 1742 int 1743 okillpg(struct thread *td, struct okillpg_args *uap) 1744 { 1745 ksiginfo_t ksi; 1746 1747 AUDIT_ARG_SIGNUM(uap->signum); 1748 AUDIT_ARG_PID(uap->pgid); 1749 if ((u_int)uap->signum > _SIG_MAXSIG) 1750 return (EINVAL); 1751 1752 ksiginfo_init(&ksi); 1753 ksi.ksi_signo = uap->signum; 1754 ksi.ksi_code = SI_USER; 1755 ksi.ksi_pid = td->td_proc->p_pid; 1756 ksi.ksi_uid = td->td_ucred->cr_ruid; 1757 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1758 } 1759 #endif /* COMPAT_43 */ 1760 1761 #ifndef _SYS_SYSPROTO_H_ 1762 struct sigqueue_args { 1763 pid_t pid; 1764 int signum; 1765 /* union sigval */ void *value; 1766 }; 1767 #endif 1768 int 1769 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1770 { 1771 ksiginfo_t ksi; 1772 struct proc *p; 1773 int error; 1774 1775 if ((u_int)uap->signum > _SIG_MAXSIG) 1776 return (EINVAL); 1777 1778 /* 1779 * Specification says sigqueue can only send signal to 1780 * single process. 1781 */ 1782 if (uap->pid <= 0) 1783 return (EINVAL); 1784 1785 if ((p = pfind(uap->pid)) == NULL) { 1786 if ((p = zpfind(uap->pid)) == NULL) 1787 return (ESRCH); 1788 } 1789 error = p_cansignal(td, p, uap->signum); 1790 if (error == 0 && uap->signum != 0) { 1791 ksiginfo_init(&ksi); 1792 ksi.ksi_flags = KSI_SIGQ; 1793 ksi.ksi_signo = uap->signum; 1794 ksi.ksi_code = SI_QUEUE; 1795 ksi.ksi_pid = td->td_proc->p_pid; 1796 ksi.ksi_uid = td->td_ucred->cr_ruid; 1797 ksi.ksi_value.sival_ptr = uap->value; 1798 error = pksignal(p, ksi.ksi_signo, &ksi); 1799 } 1800 PROC_UNLOCK(p); 1801 return (error); 1802 } 1803 1804 /* 1805 * Send a signal to a process group. 1806 */ 1807 void 1808 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1809 { 1810 struct pgrp *pgrp; 1811 1812 if (pgid != 0) { 1813 sx_slock(&proctree_lock); 1814 pgrp = pgfind(pgid); 1815 sx_sunlock(&proctree_lock); 1816 if (pgrp != NULL) { 1817 pgsignal(pgrp, sig, 0, ksi); 1818 PGRP_UNLOCK(pgrp); 1819 } 1820 } 1821 } 1822 1823 /* 1824 * Send a signal to a process group. If checktty is 1, 1825 * limit to members which have a controlling terminal. 1826 */ 1827 void 1828 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1829 { 1830 struct proc *p; 1831 1832 if (pgrp) { 1833 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1834 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1835 PROC_LOCK(p); 1836 if (p->p_state == PRS_NORMAL && 1837 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1838 pksignal(p, sig, ksi); 1839 PROC_UNLOCK(p); 1840 } 1841 } 1842 } 1843 1844 /* 1845 * Send a signal caused by a trap to the current thread. If it will be 1846 * caught immediately, deliver it with correct code. Otherwise, post it 1847 * normally. 1848 */ 1849 void 1850 trapsignal(struct thread *td, ksiginfo_t *ksi) 1851 { 1852 struct sigacts *ps; 1853 sigset_t mask; 1854 struct proc *p; 1855 int sig; 1856 int code; 1857 1858 p = td->td_proc; 1859 sig = ksi->ksi_signo; 1860 code = ksi->ksi_code; 1861 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1862 1863 PROC_LOCK(p); 1864 ps = p->p_sigacts; 1865 mtx_lock(&ps->ps_mtx); 1866 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1867 !SIGISMEMBER(td->td_sigmask, sig)) { 1868 td->td_ru.ru_nsignals++; 1869 #ifdef KTRACE 1870 if (KTRPOINT(curthread, KTR_PSIG)) 1871 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1872 &td->td_sigmask, code); 1873 #endif 1874 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1875 ksi, &td->td_sigmask); 1876 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1877 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1878 SIGADDSET(mask, sig); 1879 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1880 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1881 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1882 /* 1883 * See kern_sigaction() for origin of this code. 1884 */ 1885 SIGDELSET(ps->ps_sigcatch, sig); 1886 if (sig != SIGCONT && 1887 sigprop(sig) & SA_IGNORE) 1888 SIGADDSET(ps->ps_sigignore, sig); 1889 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1890 } 1891 mtx_unlock(&ps->ps_mtx); 1892 } else { 1893 /* 1894 * Avoid a possible infinite loop if the thread 1895 * masking the signal or process is ignoring the 1896 * signal. 1897 */ 1898 if (kern_forcesigexit && 1899 (SIGISMEMBER(td->td_sigmask, sig) || 1900 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1901 SIGDELSET(td->td_sigmask, sig); 1902 SIGDELSET(ps->ps_sigcatch, sig); 1903 SIGDELSET(ps->ps_sigignore, sig); 1904 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1905 } 1906 mtx_unlock(&ps->ps_mtx); 1907 p->p_code = code; /* XXX for core dump/debugger */ 1908 p->p_sig = sig; /* XXX to verify code */ 1909 tdsendsignal(p, td, sig, ksi); 1910 } 1911 PROC_UNLOCK(p); 1912 } 1913 1914 static struct thread * 1915 sigtd(struct proc *p, int sig, int prop) 1916 { 1917 struct thread *td, *signal_td; 1918 1919 PROC_LOCK_ASSERT(p, MA_OWNED); 1920 1921 /* 1922 * Check if current thread can handle the signal without 1923 * switching context to another thread. 1924 */ 1925 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1926 return (curthread); 1927 signal_td = NULL; 1928 FOREACH_THREAD_IN_PROC(p, td) { 1929 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1930 signal_td = td; 1931 break; 1932 } 1933 } 1934 if (signal_td == NULL) 1935 signal_td = FIRST_THREAD_IN_PROC(p); 1936 return (signal_td); 1937 } 1938 1939 /* 1940 * Send the signal to the process. If the signal has an action, the action 1941 * is usually performed by the target process rather than the caller; we add 1942 * the signal to the set of pending signals for the process. 1943 * 1944 * Exceptions: 1945 * o When a stop signal is sent to a sleeping process that takes the 1946 * default action, the process is stopped without awakening it. 1947 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1948 * regardless of the signal action (eg, blocked or ignored). 1949 * 1950 * Other ignored signals are discarded immediately. 1951 * 1952 * NB: This function may be entered from the debugger via the "kill" DDB 1953 * command. There is little that can be done to mitigate the possibly messy 1954 * side effects of this unwise possibility. 1955 */ 1956 void 1957 kern_psignal(struct proc *p, int sig) 1958 { 1959 ksiginfo_t ksi; 1960 1961 ksiginfo_init(&ksi); 1962 ksi.ksi_signo = sig; 1963 ksi.ksi_code = SI_KERNEL; 1964 (void) tdsendsignal(p, NULL, sig, &ksi); 1965 } 1966 1967 int 1968 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1969 { 1970 1971 return (tdsendsignal(p, NULL, sig, ksi)); 1972 } 1973 1974 /* Utility function for finding a thread to send signal event to. */ 1975 int 1976 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1977 { 1978 struct thread *td; 1979 1980 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1981 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 1982 if (td == NULL) 1983 return (ESRCH); 1984 *ttd = td; 1985 } else { 1986 *ttd = NULL; 1987 PROC_LOCK(p); 1988 } 1989 return (0); 1990 } 1991 1992 void 1993 tdsignal(struct thread *td, int sig) 1994 { 1995 ksiginfo_t ksi; 1996 1997 ksiginfo_init(&ksi); 1998 ksi.ksi_signo = sig; 1999 ksi.ksi_code = SI_KERNEL; 2000 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2001 } 2002 2003 void 2004 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2005 { 2006 2007 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2008 } 2009 2010 int 2011 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2012 { 2013 sig_t action; 2014 sigqueue_t *sigqueue; 2015 int prop; 2016 struct sigacts *ps; 2017 int intrval; 2018 int ret = 0; 2019 int wakeup_swapper; 2020 2021 MPASS(td == NULL || p == td->td_proc); 2022 PROC_LOCK_ASSERT(p, MA_OWNED); 2023 2024 if (!_SIG_VALID(sig)) 2025 panic("%s(): invalid signal %d", __func__, sig); 2026 2027 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2028 2029 /* 2030 * IEEE Std 1003.1-2001: return success when killing a zombie. 2031 */ 2032 if (p->p_state == PRS_ZOMBIE) { 2033 if (ksi && (ksi->ksi_flags & KSI_INS)) 2034 ksiginfo_tryfree(ksi); 2035 return (ret); 2036 } 2037 2038 ps = p->p_sigacts; 2039 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2040 prop = sigprop(sig); 2041 2042 if (td == NULL) { 2043 td = sigtd(p, sig, prop); 2044 sigqueue = &p->p_sigqueue; 2045 } else { 2046 KASSERT(td->td_proc == p, ("invalid thread")); 2047 sigqueue = &td->td_sigqueue; 2048 } 2049 2050 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2051 2052 /* 2053 * If the signal is being ignored, 2054 * then we forget about it immediately. 2055 * (Note: we don't set SIGCONT in ps_sigignore, 2056 * and if it is set to SIG_IGN, 2057 * action will be SIG_DFL here.) 2058 */ 2059 mtx_lock(&ps->ps_mtx); 2060 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2061 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 ); 2062 2063 mtx_unlock(&ps->ps_mtx); 2064 if (ksi && (ksi->ksi_flags & KSI_INS)) 2065 ksiginfo_tryfree(ksi); 2066 return (ret); 2067 } 2068 if (SIGISMEMBER(td->td_sigmask, sig)) 2069 action = SIG_HOLD; 2070 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2071 action = SIG_CATCH; 2072 else 2073 action = SIG_DFL; 2074 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2075 intrval = EINTR; 2076 else 2077 intrval = ERESTART; 2078 mtx_unlock(&ps->ps_mtx); 2079 2080 if (prop & SA_CONT) 2081 sigqueue_delete_stopmask_proc(p); 2082 else if (prop & SA_STOP) { 2083 /* 2084 * If sending a tty stop signal to a member of an orphaned 2085 * process group, discard the signal here if the action 2086 * is default; don't stop the process below if sleeping, 2087 * and don't clear any pending SIGCONT. 2088 */ 2089 if ((prop & SA_TTYSTOP) && 2090 (p->p_pgrp->pg_jobc == 0) && 2091 (action == SIG_DFL)) { 2092 if (ksi && (ksi->ksi_flags & KSI_INS)) 2093 ksiginfo_tryfree(ksi); 2094 return (ret); 2095 } 2096 sigqueue_delete_proc(p, SIGCONT); 2097 if (p->p_flag & P_CONTINUED) { 2098 p->p_flag &= ~P_CONTINUED; 2099 PROC_LOCK(p->p_pptr); 2100 sigqueue_take(p->p_ksi); 2101 PROC_UNLOCK(p->p_pptr); 2102 } 2103 } 2104 2105 ret = sigqueue_add(sigqueue, sig, ksi); 2106 if (ret != 0) 2107 return (ret); 2108 signotify(td); 2109 /* 2110 * Defer further processing for signals which are held, 2111 * except that stopped processes must be continued by SIGCONT. 2112 */ 2113 if (action == SIG_HOLD && 2114 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2115 return (ret); 2116 /* 2117 * SIGKILL: Remove procfs STOPEVENTs. 2118 */ 2119 if (sig == SIGKILL) { 2120 /* from procfs_ioctl.c: PIOCBIC */ 2121 p->p_stops = 0; 2122 /* from procfs_ioctl.c: PIOCCONT */ 2123 p->p_step = 0; 2124 wakeup(&p->p_step); 2125 } 2126 /* 2127 * Some signals have a process-wide effect and a per-thread 2128 * component. Most processing occurs when the process next 2129 * tries to cross the user boundary, however there are some 2130 * times when processing needs to be done immediatly, such as 2131 * waking up threads so that they can cross the user boundary. 2132 * We try do the per-process part here. 2133 */ 2134 if (P_SHOULDSTOP(p)) { 2135 if (sig == SIGKILL) { 2136 /* 2137 * If traced process is already stopped, 2138 * then no further action is necessary. 2139 */ 2140 if (p->p_flag & P_TRACED) 2141 goto out; 2142 /* 2143 * SIGKILL sets process running. 2144 * It will die elsewhere. 2145 * All threads must be restarted. 2146 */ 2147 p->p_flag &= ~P_STOPPED_SIG; 2148 goto runfast; 2149 } 2150 2151 if (prop & SA_CONT) { 2152 /* 2153 * If traced process is already stopped, 2154 * then no further action is necessary. 2155 */ 2156 if (p->p_flag & P_TRACED) 2157 goto out; 2158 /* 2159 * If SIGCONT is default (or ignored), we continue the 2160 * process but don't leave the signal in sigqueue as 2161 * it has no further action. If SIGCONT is held, we 2162 * continue the process and leave the signal in 2163 * sigqueue. If the process catches SIGCONT, let it 2164 * handle the signal itself. If it isn't waiting on 2165 * an event, it goes back to run state. 2166 * Otherwise, process goes back to sleep state. 2167 */ 2168 p->p_flag &= ~P_STOPPED_SIG; 2169 PROC_SLOCK(p); 2170 if (p->p_numthreads == p->p_suspcount) { 2171 PROC_SUNLOCK(p); 2172 p->p_flag |= P_CONTINUED; 2173 p->p_xstat = SIGCONT; 2174 PROC_LOCK(p->p_pptr); 2175 childproc_continued(p); 2176 PROC_UNLOCK(p->p_pptr); 2177 PROC_SLOCK(p); 2178 } 2179 if (action == SIG_DFL) { 2180 thread_unsuspend(p); 2181 PROC_SUNLOCK(p); 2182 sigqueue_delete(sigqueue, sig); 2183 goto out; 2184 } 2185 if (action == SIG_CATCH) { 2186 /* 2187 * The process wants to catch it so it needs 2188 * to run at least one thread, but which one? 2189 */ 2190 PROC_SUNLOCK(p); 2191 goto runfast; 2192 } 2193 /* 2194 * The signal is not ignored or caught. 2195 */ 2196 thread_unsuspend(p); 2197 PROC_SUNLOCK(p); 2198 goto out; 2199 } 2200 2201 if (prop & SA_STOP) { 2202 /* 2203 * If traced process is already stopped, 2204 * then no further action is necessary. 2205 */ 2206 if (p->p_flag & P_TRACED) 2207 goto out; 2208 /* 2209 * Already stopped, don't need to stop again 2210 * (If we did the shell could get confused). 2211 * Just make sure the signal STOP bit set. 2212 */ 2213 p->p_flag |= P_STOPPED_SIG; 2214 sigqueue_delete(sigqueue, sig); 2215 goto out; 2216 } 2217 2218 /* 2219 * All other kinds of signals: 2220 * If a thread is sleeping interruptibly, simulate a 2221 * wakeup so that when it is continued it will be made 2222 * runnable and can look at the signal. However, don't make 2223 * the PROCESS runnable, leave it stopped. 2224 * It may run a bit until it hits a thread_suspend_check(). 2225 */ 2226 wakeup_swapper = 0; 2227 PROC_SLOCK(p); 2228 thread_lock(td); 2229 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2230 wakeup_swapper = sleepq_abort(td, intrval); 2231 thread_unlock(td); 2232 PROC_SUNLOCK(p); 2233 if (wakeup_swapper) 2234 kick_proc0(); 2235 goto out; 2236 /* 2237 * Mutexes are short lived. Threads waiting on them will 2238 * hit thread_suspend_check() soon. 2239 */ 2240 } else if (p->p_state == PRS_NORMAL) { 2241 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2242 tdsigwakeup(td, sig, action, intrval); 2243 goto out; 2244 } 2245 2246 MPASS(action == SIG_DFL); 2247 2248 if (prop & SA_STOP) { 2249 if (p->p_flag & P_PPWAIT) 2250 goto out; 2251 p->p_flag |= P_STOPPED_SIG; 2252 p->p_xstat = sig; 2253 PROC_SLOCK(p); 2254 sig_suspend_threads(td, p, 1); 2255 if (p->p_numthreads == p->p_suspcount) { 2256 /* 2257 * only thread sending signal to another 2258 * process can reach here, if thread is sending 2259 * signal to its process, because thread does 2260 * not suspend itself here, p_numthreads 2261 * should never be equal to p_suspcount. 2262 */ 2263 thread_stopped(p); 2264 PROC_SUNLOCK(p); 2265 sigqueue_delete_proc(p, p->p_xstat); 2266 } else 2267 PROC_SUNLOCK(p); 2268 goto out; 2269 } 2270 } else { 2271 /* Not in "NORMAL" state. discard the signal. */ 2272 sigqueue_delete(sigqueue, sig); 2273 goto out; 2274 } 2275 2276 /* 2277 * The process is not stopped so we need to apply the signal to all the 2278 * running threads. 2279 */ 2280 runfast: 2281 tdsigwakeup(td, sig, action, intrval); 2282 PROC_SLOCK(p); 2283 thread_unsuspend(p); 2284 PROC_SUNLOCK(p); 2285 out: 2286 /* If we jump here, proc slock should not be owned. */ 2287 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2288 return (ret); 2289 } 2290 2291 /* 2292 * The force of a signal has been directed against a single 2293 * thread. We need to see what we can do about knocking it 2294 * out of any sleep it may be in etc. 2295 */ 2296 static void 2297 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2298 { 2299 struct proc *p = td->td_proc; 2300 register int prop; 2301 int wakeup_swapper; 2302 2303 wakeup_swapper = 0; 2304 PROC_LOCK_ASSERT(p, MA_OWNED); 2305 prop = sigprop(sig); 2306 2307 PROC_SLOCK(p); 2308 thread_lock(td); 2309 /* 2310 * Bring the priority of a thread up if we want it to get 2311 * killed in this lifetime. 2312 */ 2313 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2314 sched_prio(td, PUSER); 2315 if (TD_ON_SLEEPQ(td)) { 2316 /* 2317 * If thread is sleeping uninterruptibly 2318 * we can't interrupt the sleep... the signal will 2319 * be noticed when the process returns through 2320 * trap() or syscall(). 2321 */ 2322 if ((td->td_flags & TDF_SINTR) == 0) 2323 goto out; 2324 /* 2325 * If SIGCONT is default (or ignored) and process is 2326 * asleep, we are finished; the process should not 2327 * be awakened. 2328 */ 2329 if ((prop & SA_CONT) && action == SIG_DFL) { 2330 thread_unlock(td); 2331 PROC_SUNLOCK(p); 2332 sigqueue_delete(&p->p_sigqueue, sig); 2333 /* 2334 * It may be on either list in this state. 2335 * Remove from both for now. 2336 */ 2337 sigqueue_delete(&td->td_sigqueue, sig); 2338 return; 2339 } 2340 2341 /* 2342 * Give low priority threads a better chance to run. 2343 */ 2344 if (td->td_priority > PUSER) 2345 sched_prio(td, PUSER); 2346 2347 wakeup_swapper = sleepq_abort(td, intrval); 2348 } else { 2349 /* 2350 * Other states do nothing with the signal immediately, 2351 * other than kicking ourselves if we are running. 2352 * It will either never be noticed, or noticed very soon. 2353 */ 2354 #ifdef SMP 2355 if (TD_IS_RUNNING(td) && td != curthread) 2356 forward_signal(td); 2357 #endif 2358 } 2359 out: 2360 PROC_SUNLOCK(p); 2361 thread_unlock(td); 2362 if (wakeup_swapper) 2363 kick_proc0(); 2364 } 2365 2366 static void 2367 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2368 { 2369 struct thread *td2; 2370 int wakeup_swapper; 2371 2372 PROC_LOCK_ASSERT(p, MA_OWNED); 2373 PROC_SLOCK_ASSERT(p, MA_OWNED); 2374 2375 wakeup_swapper = 0; 2376 FOREACH_THREAD_IN_PROC(p, td2) { 2377 thread_lock(td2); 2378 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2379 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2380 (td2->td_flags & TDF_SINTR)) { 2381 if (td2->td_flags & TDF_SBDRY) { 2382 if (TD_IS_SUSPENDED(td2)) 2383 wakeup_swapper |= 2384 thread_unsuspend_one(td2); 2385 if (TD_ON_SLEEPQ(td2)) 2386 wakeup_swapper |= 2387 sleepq_abort(td2, ERESTART); 2388 } else if (!TD_IS_SUSPENDED(td2)) { 2389 thread_suspend_one(td2); 2390 } 2391 } else if (!TD_IS_SUSPENDED(td2)) { 2392 if (sending || td != td2) 2393 td2->td_flags |= TDF_ASTPENDING; 2394 #ifdef SMP 2395 if (TD_IS_RUNNING(td2) && td2 != td) 2396 forward_signal(td2); 2397 #endif 2398 } 2399 thread_unlock(td2); 2400 } 2401 if (wakeup_swapper) 2402 kick_proc0(); 2403 } 2404 2405 int 2406 ptracestop(struct thread *td, int sig) 2407 { 2408 struct proc *p = td->td_proc; 2409 2410 PROC_LOCK_ASSERT(p, MA_OWNED); 2411 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2412 &p->p_mtx.lock_object, "Stopping for traced signal"); 2413 2414 td->td_dbgflags |= TDB_XSIG; 2415 td->td_xsig = sig; 2416 PROC_SLOCK(p); 2417 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2418 if (p->p_flag & P_SINGLE_EXIT) { 2419 td->td_dbgflags &= ~TDB_XSIG; 2420 PROC_SUNLOCK(p); 2421 return (sig); 2422 } 2423 /* 2424 * Just make wait() to work, the last stopped thread 2425 * will win. 2426 */ 2427 p->p_xstat = sig; 2428 p->p_xthread = td; 2429 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2430 sig_suspend_threads(td, p, 0); 2431 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2432 td->td_dbgflags &= ~TDB_STOPATFORK; 2433 cv_broadcast(&p->p_dbgwait); 2434 } 2435 stopme: 2436 thread_suspend_switch(td); 2437 if (!(p->p_flag & P_TRACED)) { 2438 break; 2439 } 2440 if (td->td_dbgflags & TDB_SUSPEND) { 2441 if (p->p_flag & P_SINGLE_EXIT) 2442 break; 2443 goto stopme; 2444 } 2445 } 2446 PROC_SUNLOCK(p); 2447 return (td->td_xsig); 2448 } 2449 2450 static void 2451 reschedule_signals(struct proc *p, sigset_t block, int flags) 2452 { 2453 struct sigacts *ps; 2454 struct thread *td; 2455 int sig; 2456 2457 PROC_LOCK_ASSERT(p, MA_OWNED); 2458 if (SIGISEMPTY(p->p_siglist)) 2459 return; 2460 ps = p->p_sigacts; 2461 SIGSETAND(block, p->p_siglist); 2462 while ((sig = sig_ffs(&block)) != 0) { 2463 SIGDELSET(block, sig); 2464 td = sigtd(p, sig, 0); 2465 signotify(td); 2466 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2467 mtx_lock(&ps->ps_mtx); 2468 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2469 tdsigwakeup(td, sig, SIG_CATCH, 2470 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2471 ERESTART)); 2472 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2473 mtx_unlock(&ps->ps_mtx); 2474 } 2475 } 2476 2477 void 2478 tdsigcleanup(struct thread *td) 2479 { 2480 struct proc *p; 2481 sigset_t unblocked; 2482 2483 p = td->td_proc; 2484 PROC_LOCK_ASSERT(p, MA_OWNED); 2485 2486 sigqueue_flush(&td->td_sigqueue); 2487 if (p->p_numthreads == 1) 2488 return; 2489 2490 /* 2491 * Since we cannot handle signals, notify signal post code 2492 * about this by filling the sigmask. 2493 * 2494 * Also, if needed, wake up thread(s) that do not block the 2495 * same signals as the exiting thread, since the thread might 2496 * have been selected for delivery and woken up. 2497 */ 2498 SIGFILLSET(unblocked); 2499 SIGSETNAND(unblocked, td->td_sigmask); 2500 SIGFILLSET(td->td_sigmask); 2501 reschedule_signals(p, unblocked, 0); 2502 2503 } 2504 2505 /* 2506 * If the current process has received a signal (should be caught or cause 2507 * termination, should interrupt current syscall), return the signal number. 2508 * Stop signals with default action are processed immediately, then cleared; 2509 * they aren't returned. This is checked after each entry to the system for 2510 * a syscall or trap (though this can usually be done without calling issignal 2511 * by checking the pending signal masks in cursig.) The normal call 2512 * sequence is 2513 * 2514 * while (sig = cursig(curthread)) 2515 * postsig(sig); 2516 */ 2517 static int 2518 issignal(struct thread *td, int stop_allowed) 2519 { 2520 struct proc *p; 2521 struct sigacts *ps; 2522 struct sigqueue *queue; 2523 sigset_t sigpending; 2524 int sig, prop, newsig; 2525 2526 p = td->td_proc; 2527 ps = p->p_sigacts; 2528 mtx_assert(&ps->ps_mtx, MA_OWNED); 2529 PROC_LOCK_ASSERT(p, MA_OWNED); 2530 for (;;) { 2531 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2532 2533 sigpending = td->td_sigqueue.sq_signals; 2534 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2535 SIGSETNAND(sigpending, td->td_sigmask); 2536 2537 if (p->p_flag & P_PPWAIT) 2538 SIG_STOPSIGMASK(sigpending); 2539 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2540 return (0); 2541 sig = sig_ffs(&sigpending); 2542 2543 if (p->p_stops & S_SIG) { 2544 mtx_unlock(&ps->ps_mtx); 2545 stopevent(p, S_SIG, sig); 2546 mtx_lock(&ps->ps_mtx); 2547 } 2548 2549 /* 2550 * We should see pending but ignored signals 2551 * only if P_TRACED was on when they were posted. 2552 */ 2553 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2554 sigqueue_delete(&td->td_sigqueue, sig); 2555 sigqueue_delete(&p->p_sigqueue, sig); 2556 continue; 2557 } 2558 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2559 /* 2560 * If traced, always stop. 2561 * Remove old signal from queue before the stop. 2562 * XXX shrug off debugger, it causes siginfo to 2563 * be thrown away. 2564 */ 2565 queue = &td->td_sigqueue; 2566 td->td_dbgksi.ksi_signo = 0; 2567 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2568 queue = &p->p_sigqueue; 2569 sigqueue_get(queue, sig, &td->td_dbgksi); 2570 } 2571 2572 mtx_unlock(&ps->ps_mtx); 2573 newsig = ptracestop(td, sig); 2574 mtx_lock(&ps->ps_mtx); 2575 2576 if (sig != newsig) { 2577 2578 /* 2579 * If parent wants us to take the signal, 2580 * then it will leave it in p->p_xstat; 2581 * otherwise we just look for signals again. 2582 */ 2583 if (newsig == 0) 2584 continue; 2585 sig = newsig; 2586 2587 /* 2588 * Put the new signal into td_sigqueue. If the 2589 * signal is being masked, look for other signals. 2590 */ 2591 sigqueue_add(queue, sig, NULL); 2592 if (SIGISMEMBER(td->td_sigmask, sig)) 2593 continue; 2594 signotify(td); 2595 } else { 2596 if (td->td_dbgksi.ksi_signo != 0) { 2597 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2598 if (sigqueue_add(&td->td_sigqueue, sig, 2599 &td->td_dbgksi) != 0) 2600 td->td_dbgksi.ksi_signo = 0; 2601 } 2602 if (td->td_dbgksi.ksi_signo == 0) 2603 sigqueue_add(&td->td_sigqueue, sig, 2604 NULL); 2605 } 2606 2607 /* 2608 * If the traced bit got turned off, go back up 2609 * to the top to rescan signals. This ensures 2610 * that p_sig* and p_sigact are consistent. 2611 */ 2612 if ((p->p_flag & P_TRACED) == 0) 2613 continue; 2614 } 2615 2616 prop = sigprop(sig); 2617 2618 /* 2619 * Decide whether the signal should be returned. 2620 * Return the signal's number, or fall through 2621 * to clear it from the pending mask. 2622 */ 2623 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2624 2625 case (intptr_t)SIG_DFL: 2626 /* 2627 * Don't take default actions on system processes. 2628 */ 2629 if (p->p_pid <= 1) { 2630 #ifdef DIAGNOSTIC 2631 /* 2632 * Are you sure you want to ignore SIGSEGV 2633 * in init? XXX 2634 */ 2635 printf("Process (pid %lu) got signal %d\n", 2636 (u_long)p->p_pid, sig); 2637 #endif 2638 break; /* == ignore */ 2639 } 2640 /* 2641 * If there is a pending stop signal to process 2642 * with default action, stop here, 2643 * then clear the signal. However, 2644 * if process is member of an orphaned 2645 * process group, ignore tty stop signals. 2646 */ 2647 if (prop & SA_STOP) { 2648 if (p->p_flag & P_TRACED || 2649 (p->p_pgrp->pg_jobc == 0 && 2650 prop & SA_TTYSTOP)) 2651 break; /* == ignore */ 2652 2653 /* Ignore, but do not drop the stop signal. */ 2654 if (stop_allowed != SIG_STOP_ALLOWED) 2655 return (sig); 2656 mtx_unlock(&ps->ps_mtx); 2657 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2658 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2659 p->p_flag |= P_STOPPED_SIG; 2660 p->p_xstat = sig; 2661 PROC_SLOCK(p); 2662 sig_suspend_threads(td, p, 0); 2663 thread_suspend_switch(td); 2664 PROC_SUNLOCK(p); 2665 mtx_lock(&ps->ps_mtx); 2666 break; 2667 } else if (prop & SA_IGNORE) { 2668 /* 2669 * Except for SIGCONT, shouldn't get here. 2670 * Default action is to ignore; drop it. 2671 */ 2672 break; /* == ignore */ 2673 } else 2674 return (sig); 2675 /*NOTREACHED*/ 2676 2677 case (intptr_t)SIG_IGN: 2678 /* 2679 * Masking above should prevent us ever trying 2680 * to take action on an ignored signal other 2681 * than SIGCONT, unless process is traced. 2682 */ 2683 if ((prop & SA_CONT) == 0 && 2684 (p->p_flag & P_TRACED) == 0) 2685 printf("issignal\n"); 2686 break; /* == ignore */ 2687 2688 default: 2689 /* 2690 * This signal has an action, let 2691 * postsig() process it. 2692 */ 2693 return (sig); 2694 } 2695 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2696 sigqueue_delete(&p->p_sigqueue, sig); 2697 } 2698 /* NOTREACHED */ 2699 } 2700 2701 void 2702 thread_stopped(struct proc *p) 2703 { 2704 int n; 2705 2706 PROC_LOCK_ASSERT(p, MA_OWNED); 2707 PROC_SLOCK_ASSERT(p, MA_OWNED); 2708 n = p->p_suspcount; 2709 if (p == curproc) 2710 n++; 2711 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2712 PROC_SUNLOCK(p); 2713 p->p_flag &= ~P_WAITED; 2714 PROC_LOCK(p->p_pptr); 2715 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2716 CLD_TRAPPED : CLD_STOPPED); 2717 PROC_UNLOCK(p->p_pptr); 2718 PROC_SLOCK(p); 2719 } 2720 } 2721 2722 /* 2723 * Take the action for the specified signal 2724 * from the current set of pending signals. 2725 */ 2726 int 2727 postsig(sig) 2728 register int sig; 2729 { 2730 struct thread *td = curthread; 2731 register struct proc *p = td->td_proc; 2732 struct sigacts *ps; 2733 sig_t action; 2734 ksiginfo_t ksi; 2735 sigset_t returnmask, mask; 2736 2737 KASSERT(sig != 0, ("postsig")); 2738 2739 PROC_LOCK_ASSERT(p, MA_OWNED); 2740 ps = p->p_sigacts; 2741 mtx_assert(&ps->ps_mtx, MA_OWNED); 2742 ksiginfo_init(&ksi); 2743 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2744 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2745 return (0); 2746 ksi.ksi_signo = sig; 2747 if (ksi.ksi_code == SI_TIMER) 2748 itimer_accept(p, ksi.ksi_timerid, &ksi); 2749 action = ps->ps_sigact[_SIG_IDX(sig)]; 2750 #ifdef KTRACE 2751 if (KTRPOINT(td, KTR_PSIG)) 2752 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2753 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2754 #endif 2755 if (p->p_stops & S_SIG) { 2756 mtx_unlock(&ps->ps_mtx); 2757 stopevent(p, S_SIG, sig); 2758 mtx_lock(&ps->ps_mtx); 2759 } 2760 2761 if (action == SIG_DFL) { 2762 /* 2763 * Default action, where the default is to kill 2764 * the process. (Other cases were ignored above.) 2765 */ 2766 mtx_unlock(&ps->ps_mtx); 2767 sigexit(td, sig); 2768 /* NOTREACHED */ 2769 } else { 2770 /* 2771 * If we get here, the signal must be caught. 2772 */ 2773 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2774 ("postsig action")); 2775 /* 2776 * Set the new mask value and also defer further 2777 * occurrences of this signal. 2778 * 2779 * Special case: user has done a sigsuspend. Here the 2780 * current mask is not of interest, but rather the 2781 * mask from before the sigsuspend is what we want 2782 * restored after the signal processing is completed. 2783 */ 2784 if (td->td_pflags & TDP_OLDMASK) { 2785 returnmask = td->td_oldsigmask; 2786 td->td_pflags &= ~TDP_OLDMASK; 2787 } else 2788 returnmask = td->td_sigmask; 2789 2790 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2791 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2792 SIGADDSET(mask, sig); 2793 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2794 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2795 2796 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2797 /* 2798 * See kern_sigaction() for origin of this code. 2799 */ 2800 SIGDELSET(ps->ps_sigcatch, sig); 2801 if (sig != SIGCONT && 2802 sigprop(sig) & SA_IGNORE) 2803 SIGADDSET(ps->ps_sigignore, sig); 2804 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2805 } 2806 td->td_ru.ru_nsignals++; 2807 if (p->p_sig == sig) { 2808 p->p_code = 0; 2809 p->p_sig = 0; 2810 } 2811 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2812 } 2813 return (1); 2814 } 2815 2816 /* 2817 * Kill the current process for stated reason. 2818 */ 2819 void 2820 killproc(p, why) 2821 struct proc *p; 2822 char *why; 2823 { 2824 2825 PROC_LOCK_ASSERT(p, MA_OWNED); 2826 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2827 p, p->p_pid, p->p_comm); 2828 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2829 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2830 p->p_flag |= P_WKILLED; 2831 kern_psignal(p, SIGKILL); 2832 } 2833 2834 /* 2835 * Force the current process to exit with the specified signal, dumping core 2836 * if appropriate. We bypass the normal tests for masked and caught signals, 2837 * allowing unrecoverable failures to terminate the process without changing 2838 * signal state. Mark the accounting record with the signal termination. 2839 * If dumping core, save the signal number for the debugger. Calls exit and 2840 * does not return. 2841 */ 2842 void 2843 sigexit(td, sig) 2844 struct thread *td; 2845 int sig; 2846 { 2847 struct proc *p = td->td_proc; 2848 2849 PROC_LOCK_ASSERT(p, MA_OWNED); 2850 p->p_acflag |= AXSIG; 2851 /* 2852 * We must be single-threading to generate a core dump. This 2853 * ensures that the registers in the core file are up-to-date. 2854 * Also, the ELF dump handler assumes that the thread list doesn't 2855 * change out from under it. 2856 * 2857 * XXX If another thread attempts to single-thread before us 2858 * (e.g. via fork()), we won't get a dump at all. 2859 */ 2860 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2861 p->p_sig = sig; 2862 /* 2863 * Log signals which would cause core dumps 2864 * (Log as LOG_INFO to appease those who don't want 2865 * these messages.) 2866 * XXX : Todo, as well as euid, write out ruid too 2867 * Note that coredump() drops proc lock. 2868 */ 2869 if (coredump(td) == 0) 2870 sig |= WCOREFLAG; 2871 if (kern_logsigexit) 2872 log(LOG_INFO, 2873 "pid %d (%s), uid %d: exited on signal %d%s\n", 2874 p->p_pid, p->p_comm, 2875 td->td_ucred ? td->td_ucred->cr_uid : -1, 2876 sig &~ WCOREFLAG, 2877 sig & WCOREFLAG ? " (core dumped)" : ""); 2878 } else 2879 PROC_UNLOCK(p); 2880 exit1(td, W_EXITCODE(0, sig)); 2881 /* NOTREACHED */ 2882 } 2883 2884 /* 2885 * Send queued SIGCHLD to parent when child process's state 2886 * is changed. 2887 */ 2888 static void 2889 sigparent(struct proc *p, int reason, int status) 2890 { 2891 PROC_LOCK_ASSERT(p, MA_OWNED); 2892 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2893 2894 if (p->p_ksi != NULL) { 2895 p->p_ksi->ksi_signo = SIGCHLD; 2896 p->p_ksi->ksi_code = reason; 2897 p->p_ksi->ksi_status = status; 2898 p->p_ksi->ksi_pid = p->p_pid; 2899 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2900 if (KSI_ONQ(p->p_ksi)) 2901 return; 2902 } 2903 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2904 } 2905 2906 static void 2907 childproc_jobstate(struct proc *p, int reason, int status) 2908 { 2909 struct sigacts *ps; 2910 2911 PROC_LOCK_ASSERT(p, MA_OWNED); 2912 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2913 2914 /* 2915 * Wake up parent sleeping in kern_wait(), also send 2916 * SIGCHLD to parent, but SIGCHLD does not guarantee 2917 * that parent will awake, because parent may masked 2918 * the signal. 2919 */ 2920 p->p_pptr->p_flag |= P_STATCHILD; 2921 wakeup(p->p_pptr); 2922 2923 ps = p->p_pptr->p_sigacts; 2924 mtx_lock(&ps->ps_mtx); 2925 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2926 mtx_unlock(&ps->ps_mtx); 2927 sigparent(p, reason, status); 2928 } else 2929 mtx_unlock(&ps->ps_mtx); 2930 } 2931 2932 void 2933 childproc_stopped(struct proc *p, int reason) 2934 { 2935 childproc_jobstate(p, reason, p->p_xstat); 2936 } 2937 2938 void 2939 childproc_continued(struct proc *p) 2940 { 2941 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2942 } 2943 2944 void 2945 childproc_exited(struct proc *p) 2946 { 2947 int reason; 2948 int status = p->p_xstat; /* convert to int */ 2949 2950 reason = CLD_EXITED; 2951 if (WCOREDUMP(status)) 2952 reason = CLD_DUMPED; 2953 else if (WIFSIGNALED(status)) 2954 reason = CLD_KILLED; 2955 /* 2956 * XXX avoid calling wakeup(p->p_pptr), the work is 2957 * done in exit1(). 2958 */ 2959 sigparent(p, reason, status); 2960 } 2961 2962 /* 2963 * We only have 1 character for the core count in the format 2964 * string, so the range will be 0-9 2965 */ 2966 #define MAX_NUM_CORES 10 2967 static int num_cores = 5; 2968 2969 static int 2970 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 2971 { 2972 int error; 2973 int new_val; 2974 2975 new_val = num_cores; 2976 error = sysctl_handle_int(oidp, &new_val, 0, req); 2977 if (error != 0 || req->newptr == NULL) 2978 return (error); 2979 if (new_val > MAX_NUM_CORES) 2980 new_val = MAX_NUM_CORES; 2981 if (new_val < 0) 2982 new_val = 0; 2983 num_cores = new_val; 2984 return (0); 2985 } 2986 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 2987 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 2988 2989 #if defined(COMPRESS_USER_CORES) 2990 int compress_user_cores = 1; 2991 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 2992 &compress_user_cores, 0, ""); 2993 2994 int compress_user_cores_gzlevel = -1; /* default level */ 2995 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 2996 &compress_user_cores_gzlevel, -1, "user core gz compression level"); 2997 2998 #define GZ_SUFFIX ".gz" 2999 #define GZ_SUFFIX_LEN 3 3000 #endif 3001 3002 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3003 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3004 sizeof(corefilename), "process corefile name format string"); 3005 3006 /* 3007 * expand_name(name, uid, pid, td, compress) 3008 * Expand the name described in corefilename, using name, uid, and pid. 3009 * corefilename is a printf-like string, with three format specifiers: 3010 * %N name of process ("name") 3011 * %P process id (pid) 3012 * %U user id (uid) 3013 * For example, "%N.core" is the default; they can be disabled completely 3014 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3015 * This is controlled by the sysctl variable kern.corefile (see above). 3016 */ 3017 static char * 3018 expand_name(const char *name, uid_t uid, pid_t pid, struct thread *td, 3019 int compress) 3020 { 3021 struct sbuf sb; 3022 const char *format; 3023 char *temp; 3024 size_t i; 3025 int indexpos; 3026 char *hostname; 3027 3028 hostname = NULL; 3029 format = corefilename; 3030 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 3031 if (temp == NULL) 3032 return (NULL); 3033 indexpos = -1; 3034 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 3035 for (i = 0; format[i]; i++) { 3036 switch (format[i]) { 3037 case '%': /* Format character */ 3038 i++; 3039 switch (format[i]) { 3040 case '%': 3041 sbuf_putc(&sb, '%'); 3042 break; 3043 case 'H': /* hostname */ 3044 if (hostname == NULL) { 3045 hostname = malloc(MAXHOSTNAMELEN, 3046 M_TEMP, M_NOWAIT); 3047 if (hostname == NULL) { 3048 log(LOG_ERR, 3049 "pid %ld (%s), uid (%lu): " 3050 "unable to alloc memory " 3051 "for corefile hostname\n", 3052 (long)pid, name, 3053 (u_long)uid); 3054 goto nomem; 3055 } 3056 } 3057 getcredhostname(td->td_ucred, hostname, 3058 MAXHOSTNAMELEN); 3059 sbuf_printf(&sb, "%s", hostname); 3060 break; 3061 case 'I': /* autoincrementing index */ 3062 sbuf_printf(&sb, ""); 3063 indexpos = sbuf_len(&sb) - 1; 3064 break; 3065 case 'N': /* process name */ 3066 sbuf_printf(&sb, "%s", name); 3067 break; 3068 case 'P': /* process id */ 3069 sbuf_printf(&sb, "%u", pid); 3070 break; 3071 case 'U': /* user id */ 3072 sbuf_printf(&sb, "%u", uid); 3073 break; 3074 default: 3075 log(LOG_ERR, 3076 "Unknown format character %c in " 3077 "corename `%s'\n", format[i], format); 3078 } 3079 break; 3080 default: 3081 sbuf_putc(&sb, format[i]); 3082 } 3083 } 3084 free(hostname, M_TEMP); 3085 #ifdef COMPRESS_USER_CORES 3086 if (compress) { 3087 sbuf_printf(&sb, GZ_SUFFIX); 3088 } 3089 #endif 3090 if (sbuf_error(&sb) != 0) { 3091 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3092 "long\n", (long)pid, name, (u_long)uid); 3093 nomem: 3094 sbuf_delete(&sb); 3095 free(temp, M_TEMP); 3096 return (NULL); 3097 } 3098 sbuf_finish(&sb); 3099 sbuf_delete(&sb); 3100 3101 /* 3102 * If the core format has a %I in it, then we need to check 3103 * for existing corefiles before returning a name. 3104 * To do this we iterate over 0..num_cores to find a 3105 * non-existing core file name to use. 3106 */ 3107 if (indexpos != -1) { 3108 struct nameidata nd; 3109 int error, n; 3110 int flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3111 int cmode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; 3112 int vfslocked; 3113 3114 for (n = 0; n < num_cores; n++) { 3115 temp[indexpos] = '' + n; 3116 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, 3117 temp, td); 3118 error = vn_open(&nd, &flags, cmode, NULL); 3119 if (error) { 3120 if (error == EEXIST) { 3121 continue; 3122 } 3123 log(LOG_ERR, 3124 "pid %d (%s), uid (%u): Path `%s' failed " 3125 "on initial open test, error = %d\n", 3126 pid, name, uid, temp, error); 3127 free(temp, M_TEMP); 3128 return (NULL); 3129 } 3130 vfslocked = NDHASGIANT(&nd); 3131 NDFREE(&nd, NDF_ONLY_PNBUF); 3132 VOP_UNLOCK(nd.ni_vp, 0); 3133 error = vn_close(nd.ni_vp, FWRITE, td->td_ucred, td); 3134 VFS_UNLOCK_GIANT(vfslocked); 3135 if (error) { 3136 log(LOG_ERR, 3137 "pid %d (%s), uid (%u): Path `%s' failed " 3138 "on close after initial open test, " 3139 "error = %d\n", 3140 pid, name, uid, temp, error); 3141 free(temp, M_TEMP); 3142 return (NULL); 3143 } 3144 break; 3145 } 3146 } 3147 return (temp); 3148 } 3149 3150 /* 3151 * Dump a process' core. The main routine does some 3152 * policy checking, and creates the name of the coredump; 3153 * then it passes on a vnode and a size limit to the process-specific 3154 * coredump routine if there is one; if there _is not_ one, it returns 3155 * ENOSYS; otherwise it returns the error from the process-specific routine. 3156 */ 3157 3158 static int 3159 coredump(struct thread *td) 3160 { 3161 struct proc *p = td->td_proc; 3162 register struct vnode *vp; 3163 register struct ucred *cred = td->td_ucred; 3164 struct flock lf; 3165 struct nameidata nd; 3166 struct vattr vattr; 3167 int error, error1, flags, locked; 3168 struct mount *mp; 3169 char *name; /* name of corefile */ 3170 off_t limit; 3171 int vfslocked; 3172 int compress; 3173 3174 #ifdef COMPRESS_USER_CORES 3175 compress = compress_user_cores; 3176 #else 3177 compress = 0; 3178 #endif 3179 PROC_LOCK_ASSERT(p, MA_OWNED); 3180 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3181 _STOPEVENT(p, S_CORE, 0); 3182 3183 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid, td, 3184 compress); 3185 if (name == NULL) { 3186 PROC_UNLOCK(p); 3187 #ifdef AUDIT 3188 audit_proc_coredump(td, NULL, EINVAL); 3189 #endif 3190 return (EINVAL); 3191 } 3192 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3193 PROC_UNLOCK(p); 3194 #ifdef AUDIT 3195 audit_proc_coredump(td, name, EFAULT); 3196 #endif 3197 free(name, M_TEMP); 3198 return (EFAULT); 3199 } 3200 3201 /* 3202 * Note that the bulk of limit checking is done after 3203 * the corefile is created. The exception is if the limit 3204 * for corefiles is 0, in which case we don't bother 3205 * creating the corefile at all. This layout means that 3206 * a corefile is truncated instead of not being created, 3207 * if it is larger than the limit. 3208 */ 3209 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3210 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3211 PROC_UNLOCK(p); 3212 #ifdef AUDIT 3213 audit_proc_coredump(td, name, EFBIG); 3214 #endif 3215 free(name, M_TEMP); 3216 return (EFBIG); 3217 } 3218 PROC_UNLOCK(p); 3219 3220 restart: 3221 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3222 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3223 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3224 cred, NULL); 3225 if (error) { 3226 #ifdef AUDIT 3227 audit_proc_coredump(td, name, error); 3228 #endif 3229 free(name, M_TEMP); 3230 return (error); 3231 } 3232 vfslocked = NDHASGIANT(&nd); 3233 NDFREE(&nd, NDF_ONLY_PNBUF); 3234 vp = nd.ni_vp; 3235 3236 /* Don't dump to non-regular files or files with links. */ 3237 if (vp->v_type != VREG || 3238 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3239 VOP_UNLOCK(vp, 0); 3240 error = EFAULT; 3241 goto close; 3242 } 3243 3244 VOP_UNLOCK(vp, 0); 3245 lf.l_whence = SEEK_SET; 3246 lf.l_start = 0; 3247 lf.l_len = 0; 3248 lf.l_type = F_WRLCK; 3249 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3250 3251 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3252 lf.l_type = F_UNLCK; 3253 if (locked) 3254 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3255 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3256 goto out; 3257 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3258 goto out; 3259 VFS_UNLOCK_GIANT(vfslocked); 3260 goto restart; 3261 } 3262 3263 VATTR_NULL(&vattr); 3264 vattr.va_size = 0; 3265 if (set_core_nodump_flag) 3266 vattr.va_flags = UF_NODUMP; 3267 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3268 VOP_SETATTR(vp, &vattr, cred); 3269 VOP_UNLOCK(vp, 0); 3270 vn_finished_write(mp); 3271 PROC_LOCK(p); 3272 p->p_acflag |= ACORE; 3273 PROC_UNLOCK(p); 3274 3275 error = p->p_sysent->sv_coredump ? 3276 p->p_sysent->sv_coredump(td, vp, limit, compress ? IMGACT_CORE_COMPRESS : 0) : 3277 ENOSYS; 3278 3279 if (locked) { 3280 lf.l_type = F_UNLCK; 3281 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3282 } 3283 close: 3284 error1 = vn_close(vp, FWRITE, cred, td); 3285 if (error == 0) 3286 error = error1; 3287 out: 3288 #ifdef AUDIT 3289 audit_proc_coredump(td, name, error); 3290 #endif 3291 free(name, M_TEMP); 3292 VFS_UNLOCK_GIANT(vfslocked); 3293 return (error); 3294 } 3295 3296 /* 3297 * Nonexistent system call-- signal process (may want to handle it). Flag 3298 * error in case process won't see signal immediately (blocked or ignored). 3299 */ 3300 #ifndef _SYS_SYSPROTO_H_ 3301 struct nosys_args { 3302 int dummy; 3303 }; 3304 #endif 3305 /* ARGSUSED */ 3306 int 3307 nosys(td, args) 3308 struct thread *td; 3309 struct nosys_args *args; 3310 { 3311 struct proc *p = td->td_proc; 3312 3313 PROC_LOCK(p); 3314 kern_psignal(p, SIGSYS); 3315 PROC_UNLOCK(p); 3316 return (ENOSYS); 3317 } 3318 3319 /* 3320 * Send a SIGIO or SIGURG signal to a process or process group using stored 3321 * credentials rather than those of the current process. 3322 */ 3323 void 3324 pgsigio(sigiop, sig, checkctty) 3325 struct sigio **sigiop; 3326 int sig, checkctty; 3327 { 3328 ksiginfo_t ksi; 3329 struct sigio *sigio; 3330 3331 ksiginfo_init(&ksi); 3332 ksi.ksi_signo = sig; 3333 ksi.ksi_code = SI_KERNEL; 3334 3335 SIGIO_LOCK(); 3336 sigio = *sigiop; 3337 if (sigio == NULL) { 3338 SIGIO_UNLOCK(); 3339 return; 3340 } 3341 if (sigio->sio_pgid > 0) { 3342 PROC_LOCK(sigio->sio_proc); 3343 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3344 kern_psignal(sigio->sio_proc, sig); 3345 PROC_UNLOCK(sigio->sio_proc); 3346 } else if (sigio->sio_pgid < 0) { 3347 struct proc *p; 3348 3349 PGRP_LOCK(sigio->sio_pgrp); 3350 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3351 PROC_LOCK(p); 3352 if (p->p_state == PRS_NORMAL && 3353 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3354 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3355 kern_psignal(p, sig); 3356 PROC_UNLOCK(p); 3357 } 3358 PGRP_UNLOCK(sigio->sio_pgrp); 3359 } 3360 SIGIO_UNLOCK(); 3361 } 3362 3363 static int 3364 filt_sigattach(struct knote *kn) 3365 { 3366 struct proc *p = curproc; 3367 3368 kn->kn_ptr.p_proc = p; 3369 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3370 3371 knlist_add(&p->p_klist, kn, 0); 3372 3373 return (0); 3374 } 3375 3376 static void 3377 filt_sigdetach(struct knote *kn) 3378 { 3379 struct proc *p = kn->kn_ptr.p_proc; 3380 3381 knlist_remove(&p->p_klist, kn, 0); 3382 } 3383 3384 /* 3385 * signal knotes are shared with proc knotes, so we apply a mask to 3386 * the hint in order to differentiate them from process hints. This 3387 * could be avoided by using a signal-specific knote list, but probably 3388 * isn't worth the trouble. 3389 */ 3390 static int 3391 filt_signal(struct knote *kn, long hint) 3392 { 3393 3394 if (hint & NOTE_SIGNAL) { 3395 hint &= ~NOTE_SIGNAL; 3396 3397 if (kn->kn_id == hint) 3398 kn->kn_data++; 3399 } 3400 return (kn->kn_data != 0); 3401 } 3402 3403 struct sigacts * 3404 sigacts_alloc(void) 3405 { 3406 struct sigacts *ps; 3407 3408 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3409 ps->ps_refcnt = 1; 3410 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3411 return (ps); 3412 } 3413 3414 void 3415 sigacts_free(struct sigacts *ps) 3416 { 3417 3418 mtx_lock(&ps->ps_mtx); 3419 ps->ps_refcnt--; 3420 if (ps->ps_refcnt == 0) { 3421 mtx_destroy(&ps->ps_mtx); 3422 free(ps, M_SUBPROC); 3423 } else 3424 mtx_unlock(&ps->ps_mtx); 3425 } 3426 3427 struct sigacts * 3428 sigacts_hold(struct sigacts *ps) 3429 { 3430 mtx_lock(&ps->ps_mtx); 3431 ps->ps_refcnt++; 3432 mtx_unlock(&ps->ps_mtx); 3433 return (ps); 3434 } 3435 3436 void 3437 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3438 { 3439 3440 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3441 mtx_lock(&src->ps_mtx); 3442 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3443 mtx_unlock(&src->ps_mtx); 3444 } 3445 3446 int 3447 sigacts_shared(struct sigacts *ps) 3448 { 3449 int shared; 3450 3451 mtx_lock(&ps->ps_mtx); 3452 shared = ps->ps_refcnt > 1; 3453 mtx_unlock(&ps->ps_mtx); 3454 return (shared); 3455 }
Cache object: 39a9adfaedd67fd41b9ad2261879f87e
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