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/10.0/sys/kern/kern_sig.c 255219 2013-09-05 00:09:56Z pjd $"); 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_DEFINE3(proc, kernel, , signal_send, signal-send, "struct thread *", 97 "struct proc *", "int"); 98 SDT_PROBE_DEFINE2(proc, kernel, , signal_clear, signal-clear, "int", 99 "ksiginfo_t *"); 100 SDT_PROBE_DEFINE3(proc, kernel, , signal_discard, signal-discard, 101 "struct thread *", "struct proc *", "int"); 102 103 static int coredump(struct thread *); 104 static int killpg1(struct thread *td, int sig, int pgid, int all, 105 ksiginfo_t *ksi); 106 static int issignal(struct thread *td); 107 static int sigprop(int sig); 108 static void tdsigwakeup(struct thread *, int, sig_t, int); 109 static void sig_suspend_threads(struct thread *, struct proc *, int); 110 static int filt_sigattach(struct knote *kn); 111 static void filt_sigdetach(struct knote *kn); 112 static int filt_signal(struct knote *kn, long hint); 113 static struct thread *sigtd(struct proc *p, int sig, int prop); 114 static void sigqueue_start(void); 115 116 static uma_zone_t ksiginfo_zone = NULL; 117 struct filterops sig_filtops = { 118 .f_isfd = 0, 119 .f_attach = filt_sigattach, 120 .f_detach = filt_sigdetach, 121 .f_event = filt_signal, 122 }; 123 124 static int kern_logsigexit = 1; 125 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 126 &kern_logsigexit, 0, 127 "Log processes quitting on abnormal signals to syslog(3)"); 128 129 static int kern_forcesigexit = 1; 130 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 131 &kern_forcesigexit, 0, "Force trap signal to be handled"); 132 133 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 134 "POSIX real time signal"); 135 136 static int max_pending_per_proc = 128; 137 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 138 &max_pending_per_proc, 0, "Max pending signals per proc"); 139 140 static int preallocate_siginfo = 1024; 141 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 143 &preallocate_siginfo, 0, "Preallocated signal memory size"); 144 145 static int signal_overflow = 0; 146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 147 &signal_overflow, 0, "Number of signals overflew"); 148 149 static int signal_alloc_fail = 0; 150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 151 &signal_alloc_fail, 0, "signals failed to be allocated"); 152 153 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 154 155 /* 156 * Policy -- Can ucred cr1 send SIGIO to process cr2? 157 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 158 * in the right situations. 159 */ 160 #define CANSIGIO(cr1, cr2) \ 161 ((cr1)->cr_uid == 0 || \ 162 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 163 (cr1)->cr_uid == (cr2)->cr_ruid || \ 164 (cr1)->cr_ruid == (cr2)->cr_uid || \ 165 (cr1)->cr_uid == (cr2)->cr_uid) 166 167 static int sugid_coredump; 168 TUNABLE_INT("kern.sugid_coredump", &sugid_coredump); 169 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 170 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 171 172 static int capmode_coredump; 173 TUNABLE_INT("kern.capmode_coredump", &capmode_coredump); 174 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW, 175 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 176 177 static int do_coredump = 1; 178 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 179 &do_coredump, 0, "Enable/Disable coredumps"); 180 181 static int set_core_nodump_flag = 0; 182 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 183 0, "Enable setting the NODUMP flag on coredump files"); 184 185 /* 186 * Signal properties and actions. 187 * The array below categorizes the signals and their default actions 188 * according to the following properties: 189 */ 190 #define SA_KILL 0x01 /* terminates process by default */ 191 #define SA_CORE 0x02 /* ditto and coredumps */ 192 #define SA_STOP 0x04 /* suspend process */ 193 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 194 #define SA_IGNORE 0x10 /* ignore by default */ 195 #define SA_CONT 0x20 /* continue if suspended */ 196 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 197 198 static int sigproptbl[NSIG] = { 199 SA_KILL, /* SIGHUP */ 200 SA_KILL, /* SIGINT */ 201 SA_KILL|SA_CORE, /* SIGQUIT */ 202 SA_KILL|SA_CORE, /* SIGILL */ 203 SA_KILL|SA_CORE, /* SIGTRAP */ 204 SA_KILL|SA_CORE, /* SIGABRT */ 205 SA_KILL|SA_CORE, /* SIGEMT */ 206 SA_KILL|SA_CORE, /* SIGFPE */ 207 SA_KILL, /* SIGKILL */ 208 SA_KILL|SA_CORE, /* SIGBUS */ 209 SA_KILL|SA_CORE, /* SIGSEGV */ 210 SA_KILL|SA_CORE, /* SIGSYS */ 211 SA_KILL, /* SIGPIPE */ 212 SA_KILL, /* SIGALRM */ 213 SA_KILL, /* SIGTERM */ 214 SA_IGNORE, /* SIGURG */ 215 SA_STOP, /* SIGSTOP */ 216 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 217 SA_IGNORE|SA_CONT, /* SIGCONT */ 218 SA_IGNORE, /* SIGCHLD */ 219 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 220 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 221 SA_IGNORE, /* SIGIO */ 222 SA_KILL, /* SIGXCPU */ 223 SA_KILL, /* SIGXFSZ */ 224 SA_KILL, /* SIGVTALRM */ 225 SA_KILL, /* SIGPROF */ 226 SA_IGNORE, /* SIGWINCH */ 227 SA_IGNORE, /* SIGINFO */ 228 SA_KILL, /* SIGUSR1 */ 229 SA_KILL, /* 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 thread td, the current 559 * thread, 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) 564 { 565 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 566 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 567 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 568 return (SIGPENDING(td) ? issignal(td) : 0); 569 } 570 571 /* 572 * Arrange for ast() to handle unmasked pending signals on return to user 573 * mode. This must be called whenever a signal is added to td_sigqueue or 574 * unmasked in td_sigmask. 575 */ 576 void 577 signotify(struct thread *td) 578 { 579 struct proc *p; 580 581 p = td->td_proc; 582 583 PROC_LOCK_ASSERT(p, MA_OWNED); 584 585 if (SIGPENDING(td)) { 586 thread_lock(td); 587 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 588 thread_unlock(td); 589 } 590 } 591 592 int 593 sigonstack(size_t sp) 594 { 595 struct thread *td = curthread; 596 597 return ((td->td_pflags & TDP_ALTSTACK) ? 598 #if defined(COMPAT_43) 599 ((td->td_sigstk.ss_size == 0) ? 600 (td->td_sigstk.ss_flags & SS_ONSTACK) : 601 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 602 #else 603 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 604 #endif 605 : 0); 606 } 607 608 static __inline int 609 sigprop(int sig) 610 { 611 612 if (sig > 0 && sig < NSIG) 613 return (sigproptbl[_SIG_IDX(sig)]); 614 return (0); 615 } 616 617 int 618 sig_ffs(sigset_t *set) 619 { 620 int i; 621 622 for (i = 0; i < _SIG_WORDS; i++) 623 if (set->__bits[i]) 624 return (ffs(set->__bits[i]) + (i * 32)); 625 return (0); 626 } 627 628 /* 629 * kern_sigaction 630 * sigaction 631 * freebsd4_sigaction 632 * osigaction 633 */ 634 int 635 kern_sigaction(td, sig, act, oact, flags) 636 struct thread *td; 637 register int sig; 638 struct sigaction *act, *oact; 639 int flags; 640 { 641 struct sigacts *ps; 642 struct proc *p = td->td_proc; 643 644 if (!_SIG_VALID(sig)) 645 return (EINVAL); 646 647 PROC_LOCK(p); 648 ps = p->p_sigacts; 649 mtx_lock(&ps->ps_mtx); 650 if (oact) { 651 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 652 oact->sa_flags = 0; 653 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 654 oact->sa_flags |= SA_ONSTACK; 655 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 656 oact->sa_flags |= SA_RESTART; 657 if (SIGISMEMBER(ps->ps_sigreset, sig)) 658 oact->sa_flags |= SA_RESETHAND; 659 if (SIGISMEMBER(ps->ps_signodefer, sig)) 660 oact->sa_flags |= SA_NODEFER; 661 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 662 oact->sa_flags |= SA_SIGINFO; 663 oact->sa_sigaction = 664 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 665 } else 666 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 667 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 668 oact->sa_flags |= SA_NOCLDSTOP; 669 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 670 oact->sa_flags |= SA_NOCLDWAIT; 671 } 672 if (act) { 673 if ((sig == SIGKILL || sig == SIGSTOP) && 674 act->sa_handler != SIG_DFL) { 675 mtx_unlock(&ps->ps_mtx); 676 PROC_UNLOCK(p); 677 return (EINVAL); 678 } 679 680 /* 681 * Change setting atomically. 682 */ 683 684 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 685 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 686 if (act->sa_flags & SA_SIGINFO) { 687 ps->ps_sigact[_SIG_IDX(sig)] = 688 (__sighandler_t *)act->sa_sigaction; 689 SIGADDSET(ps->ps_siginfo, sig); 690 } else { 691 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 692 SIGDELSET(ps->ps_siginfo, sig); 693 } 694 if (!(act->sa_flags & SA_RESTART)) 695 SIGADDSET(ps->ps_sigintr, sig); 696 else 697 SIGDELSET(ps->ps_sigintr, sig); 698 if (act->sa_flags & SA_ONSTACK) 699 SIGADDSET(ps->ps_sigonstack, sig); 700 else 701 SIGDELSET(ps->ps_sigonstack, sig); 702 if (act->sa_flags & SA_RESETHAND) 703 SIGADDSET(ps->ps_sigreset, sig); 704 else 705 SIGDELSET(ps->ps_sigreset, sig); 706 if (act->sa_flags & SA_NODEFER) 707 SIGADDSET(ps->ps_signodefer, sig); 708 else 709 SIGDELSET(ps->ps_signodefer, sig); 710 if (sig == SIGCHLD) { 711 if (act->sa_flags & SA_NOCLDSTOP) 712 ps->ps_flag |= PS_NOCLDSTOP; 713 else 714 ps->ps_flag &= ~PS_NOCLDSTOP; 715 if (act->sa_flags & SA_NOCLDWAIT) { 716 /* 717 * Paranoia: since SA_NOCLDWAIT is implemented 718 * by reparenting the dying child to PID 1 (and 719 * trust it to reap the zombie), PID 1 itself 720 * is forbidden to set SA_NOCLDWAIT. 721 */ 722 if (p->p_pid == 1) 723 ps->ps_flag &= ~PS_NOCLDWAIT; 724 else 725 ps->ps_flag |= PS_NOCLDWAIT; 726 } else 727 ps->ps_flag &= ~PS_NOCLDWAIT; 728 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 729 ps->ps_flag |= PS_CLDSIGIGN; 730 else 731 ps->ps_flag &= ~PS_CLDSIGIGN; 732 } 733 /* 734 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 735 * and for signals set to SIG_DFL where the default is to 736 * ignore. However, don't put SIGCONT in ps_sigignore, as we 737 * have to restart the process. 738 */ 739 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 740 (sigprop(sig) & SA_IGNORE && 741 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 742 /* never to be seen again */ 743 sigqueue_delete_proc(p, sig); 744 if (sig != SIGCONT) 745 /* easier in psignal */ 746 SIGADDSET(ps->ps_sigignore, sig); 747 SIGDELSET(ps->ps_sigcatch, sig); 748 } else { 749 SIGDELSET(ps->ps_sigignore, sig); 750 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 751 SIGDELSET(ps->ps_sigcatch, sig); 752 else 753 SIGADDSET(ps->ps_sigcatch, sig); 754 } 755 #ifdef COMPAT_FREEBSD4 756 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 757 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 758 (flags & KSA_FREEBSD4) == 0) 759 SIGDELSET(ps->ps_freebsd4, sig); 760 else 761 SIGADDSET(ps->ps_freebsd4, sig); 762 #endif 763 #ifdef COMPAT_43 764 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 765 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 766 (flags & KSA_OSIGSET) == 0) 767 SIGDELSET(ps->ps_osigset, sig); 768 else 769 SIGADDSET(ps->ps_osigset, sig); 770 #endif 771 } 772 mtx_unlock(&ps->ps_mtx); 773 PROC_UNLOCK(p); 774 return (0); 775 } 776 777 #ifndef _SYS_SYSPROTO_H_ 778 struct sigaction_args { 779 int sig; 780 struct sigaction *act; 781 struct sigaction *oact; 782 }; 783 #endif 784 int 785 sys_sigaction(td, uap) 786 struct thread *td; 787 register struct sigaction_args *uap; 788 { 789 struct sigaction act, oact; 790 register struct sigaction *actp, *oactp; 791 int error; 792 793 actp = (uap->act != NULL) ? &act : NULL; 794 oactp = (uap->oact != NULL) ? &oact : NULL; 795 if (actp) { 796 error = copyin(uap->act, actp, sizeof(act)); 797 if (error) 798 return (error); 799 } 800 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 801 if (oactp && !error) 802 error = copyout(oactp, uap->oact, sizeof(oact)); 803 return (error); 804 } 805 806 #ifdef COMPAT_FREEBSD4 807 #ifndef _SYS_SYSPROTO_H_ 808 struct freebsd4_sigaction_args { 809 int sig; 810 struct sigaction *act; 811 struct sigaction *oact; 812 }; 813 #endif 814 int 815 freebsd4_sigaction(td, uap) 816 struct thread *td; 817 register struct freebsd4_sigaction_args *uap; 818 { 819 struct sigaction act, oact; 820 register struct sigaction *actp, *oactp; 821 int error; 822 823 824 actp = (uap->act != NULL) ? &act : NULL; 825 oactp = (uap->oact != NULL) ? &oact : NULL; 826 if (actp) { 827 error = copyin(uap->act, actp, sizeof(act)); 828 if (error) 829 return (error); 830 } 831 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 832 if (oactp && !error) 833 error = copyout(oactp, uap->oact, sizeof(oact)); 834 return (error); 835 } 836 #endif /* COMAPT_FREEBSD4 */ 837 838 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 839 #ifndef _SYS_SYSPROTO_H_ 840 struct osigaction_args { 841 int signum; 842 struct osigaction *nsa; 843 struct osigaction *osa; 844 }; 845 #endif 846 int 847 osigaction(td, uap) 848 struct thread *td; 849 register struct osigaction_args *uap; 850 { 851 struct osigaction sa; 852 struct sigaction nsa, osa; 853 register struct sigaction *nsap, *osap; 854 int error; 855 856 if (uap->signum <= 0 || uap->signum >= ONSIG) 857 return (EINVAL); 858 859 nsap = (uap->nsa != NULL) ? &nsa : NULL; 860 osap = (uap->osa != NULL) ? &osa : NULL; 861 862 if (nsap) { 863 error = copyin(uap->nsa, &sa, sizeof(sa)); 864 if (error) 865 return (error); 866 nsap->sa_handler = sa.sa_handler; 867 nsap->sa_flags = sa.sa_flags; 868 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 869 } 870 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 871 if (osap && !error) { 872 sa.sa_handler = osap->sa_handler; 873 sa.sa_flags = osap->sa_flags; 874 SIG2OSIG(osap->sa_mask, sa.sa_mask); 875 error = copyout(&sa, uap->osa, sizeof(sa)); 876 } 877 return (error); 878 } 879 880 #if !defined(__i386__) 881 /* Avoid replicating the same stub everywhere */ 882 int 883 osigreturn(td, uap) 884 struct thread *td; 885 struct osigreturn_args *uap; 886 { 887 888 return (nosys(td, (struct nosys_args *)uap)); 889 } 890 #endif 891 #endif /* COMPAT_43 */ 892 893 /* 894 * Initialize signal state for process 0; 895 * set to ignore signals that are ignored by default. 896 */ 897 void 898 siginit(p) 899 struct proc *p; 900 { 901 register int i; 902 struct sigacts *ps; 903 904 PROC_LOCK(p); 905 ps = p->p_sigacts; 906 mtx_lock(&ps->ps_mtx); 907 for (i = 1; i <= NSIG; i++) 908 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 909 SIGADDSET(ps->ps_sigignore, i); 910 mtx_unlock(&ps->ps_mtx); 911 PROC_UNLOCK(p); 912 } 913 914 /* 915 * Reset signals for an exec of the specified process. 916 */ 917 void 918 execsigs(struct proc *p) 919 { 920 struct sigacts *ps; 921 int sig; 922 struct thread *td; 923 924 /* 925 * Reset caught signals. Held signals remain held 926 * through td_sigmask (unless they were caught, 927 * and are now ignored by default). 928 */ 929 PROC_LOCK_ASSERT(p, MA_OWNED); 930 td = FIRST_THREAD_IN_PROC(p); 931 ps = p->p_sigacts; 932 mtx_lock(&ps->ps_mtx); 933 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 934 sig = sig_ffs(&ps->ps_sigcatch); 935 SIGDELSET(ps->ps_sigcatch, sig); 936 if (sigprop(sig) & SA_IGNORE) { 937 if (sig != SIGCONT) 938 SIGADDSET(ps->ps_sigignore, sig); 939 sigqueue_delete_proc(p, sig); 940 } 941 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 942 } 943 /* 944 * Reset stack state to the user stack. 945 * Clear set of signals caught on the signal stack. 946 */ 947 td->td_sigstk.ss_flags = SS_DISABLE; 948 td->td_sigstk.ss_size = 0; 949 td->td_sigstk.ss_sp = 0; 950 td->td_pflags &= ~TDP_ALTSTACK; 951 /* 952 * Reset no zombies if child dies flag as Solaris does. 953 */ 954 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 955 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 956 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 957 mtx_unlock(&ps->ps_mtx); 958 } 959 960 /* 961 * kern_sigprocmask() 962 * 963 * Manipulate signal mask. 964 */ 965 int 966 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 967 int flags) 968 { 969 sigset_t new_block, oset1; 970 struct proc *p; 971 int error; 972 973 p = td->td_proc; 974 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 975 PROC_LOCK(p); 976 if (oset != NULL) 977 *oset = td->td_sigmask; 978 979 error = 0; 980 if (set != NULL) { 981 switch (how) { 982 case SIG_BLOCK: 983 SIG_CANTMASK(*set); 984 oset1 = td->td_sigmask; 985 SIGSETOR(td->td_sigmask, *set); 986 new_block = td->td_sigmask; 987 SIGSETNAND(new_block, oset1); 988 break; 989 case SIG_UNBLOCK: 990 SIGSETNAND(td->td_sigmask, *set); 991 signotify(td); 992 goto out; 993 case SIG_SETMASK: 994 SIG_CANTMASK(*set); 995 oset1 = td->td_sigmask; 996 if (flags & SIGPROCMASK_OLD) 997 SIGSETLO(td->td_sigmask, *set); 998 else 999 td->td_sigmask = *set; 1000 new_block = td->td_sigmask; 1001 SIGSETNAND(new_block, oset1); 1002 signotify(td); 1003 break; 1004 default: 1005 error = EINVAL; 1006 goto out; 1007 } 1008 1009 /* 1010 * The new_block set contains signals that were not previously 1011 * blocked, but are blocked now. 1012 * 1013 * In case we block any signal that was not previously blocked 1014 * for td, and process has the signal pending, try to schedule 1015 * signal delivery to some thread that does not block the 1016 * signal, possibly waking it up. 1017 */ 1018 if (p->p_numthreads != 1) 1019 reschedule_signals(p, new_block, flags); 1020 } 1021 1022 out: 1023 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1024 PROC_UNLOCK(p); 1025 return (error); 1026 } 1027 1028 #ifndef _SYS_SYSPROTO_H_ 1029 struct sigprocmask_args { 1030 int how; 1031 const sigset_t *set; 1032 sigset_t *oset; 1033 }; 1034 #endif 1035 int 1036 sys_sigprocmask(td, uap) 1037 register struct thread *td; 1038 struct sigprocmask_args *uap; 1039 { 1040 sigset_t set, oset; 1041 sigset_t *setp, *osetp; 1042 int error; 1043 1044 setp = (uap->set != NULL) ? &set : NULL; 1045 osetp = (uap->oset != NULL) ? &oset : NULL; 1046 if (setp) { 1047 error = copyin(uap->set, setp, sizeof(set)); 1048 if (error) 1049 return (error); 1050 } 1051 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1052 if (osetp && !error) { 1053 error = copyout(osetp, uap->oset, sizeof(oset)); 1054 } 1055 return (error); 1056 } 1057 1058 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1059 #ifndef _SYS_SYSPROTO_H_ 1060 struct osigprocmask_args { 1061 int how; 1062 osigset_t mask; 1063 }; 1064 #endif 1065 int 1066 osigprocmask(td, uap) 1067 register struct thread *td; 1068 struct osigprocmask_args *uap; 1069 { 1070 sigset_t set, oset; 1071 int error; 1072 1073 OSIG2SIG(uap->mask, set); 1074 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1075 SIG2OSIG(oset, td->td_retval[0]); 1076 return (error); 1077 } 1078 #endif /* COMPAT_43 */ 1079 1080 int 1081 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1082 { 1083 ksiginfo_t ksi; 1084 sigset_t set; 1085 int error; 1086 1087 error = copyin(uap->set, &set, sizeof(set)); 1088 if (error) { 1089 td->td_retval[0] = error; 1090 return (0); 1091 } 1092 1093 error = kern_sigtimedwait(td, set, &ksi, NULL); 1094 if (error) { 1095 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1096 error = ERESTART; 1097 if (error == ERESTART) 1098 return (error); 1099 td->td_retval[0] = error; 1100 return (0); 1101 } 1102 1103 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1104 td->td_retval[0] = error; 1105 return (0); 1106 } 1107 1108 int 1109 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1110 { 1111 struct timespec ts; 1112 struct timespec *timeout; 1113 sigset_t set; 1114 ksiginfo_t ksi; 1115 int error; 1116 1117 if (uap->timeout) { 1118 error = copyin(uap->timeout, &ts, sizeof(ts)); 1119 if (error) 1120 return (error); 1121 1122 timeout = &ts; 1123 } else 1124 timeout = NULL; 1125 1126 error = copyin(uap->set, &set, sizeof(set)); 1127 if (error) 1128 return (error); 1129 1130 error = kern_sigtimedwait(td, set, &ksi, timeout); 1131 if (error) 1132 return (error); 1133 1134 if (uap->info) 1135 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1136 1137 if (error == 0) 1138 td->td_retval[0] = ksi.ksi_signo; 1139 return (error); 1140 } 1141 1142 int 1143 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1144 { 1145 ksiginfo_t ksi; 1146 sigset_t set; 1147 int error; 1148 1149 error = copyin(uap->set, &set, sizeof(set)); 1150 if (error) 1151 return (error); 1152 1153 error = kern_sigtimedwait(td, set, &ksi, NULL); 1154 if (error) 1155 return (error); 1156 1157 if (uap->info) 1158 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1159 1160 if (error == 0) 1161 td->td_retval[0] = ksi.ksi_signo; 1162 return (error); 1163 } 1164 1165 int 1166 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1167 struct timespec *timeout) 1168 { 1169 struct sigacts *ps; 1170 sigset_t saved_mask, new_block; 1171 struct proc *p; 1172 int error, sig, timo, timevalid = 0; 1173 struct timespec rts, ets, ts; 1174 struct timeval tv; 1175 1176 p = td->td_proc; 1177 error = 0; 1178 ets.tv_sec = 0; 1179 ets.tv_nsec = 0; 1180 1181 if (timeout != NULL) { 1182 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1183 timevalid = 1; 1184 getnanouptime(&rts); 1185 ets = rts; 1186 timespecadd(&ets, timeout); 1187 } 1188 } 1189 ksiginfo_init(ksi); 1190 /* Some signals can not be waited for. */ 1191 SIG_CANTMASK(waitset); 1192 ps = p->p_sigacts; 1193 PROC_LOCK(p); 1194 saved_mask = td->td_sigmask; 1195 SIGSETNAND(td->td_sigmask, waitset); 1196 for (;;) { 1197 mtx_lock(&ps->ps_mtx); 1198 sig = cursig(td); 1199 mtx_unlock(&ps->ps_mtx); 1200 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1201 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1202 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1203 error = 0; 1204 break; 1205 } 1206 } 1207 1208 if (error != 0) 1209 break; 1210 1211 /* 1212 * POSIX says this must be checked after looking for pending 1213 * signals. 1214 */ 1215 if (timeout != NULL) { 1216 if (!timevalid) { 1217 error = EINVAL; 1218 break; 1219 } 1220 getnanouptime(&rts); 1221 if (timespeccmp(&rts, &ets, >=)) { 1222 error = EAGAIN; 1223 break; 1224 } 1225 ts = ets; 1226 timespecsub(&ts, &rts); 1227 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1228 timo = tvtohz(&tv); 1229 } else { 1230 timo = 0; 1231 } 1232 1233 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1234 1235 if (timeout != NULL) { 1236 if (error == ERESTART) { 1237 /* Timeout can not be restarted. */ 1238 error = EINTR; 1239 } else if (error == EAGAIN) { 1240 /* We will calculate timeout by ourself. */ 1241 error = 0; 1242 } 1243 } 1244 } 1245 1246 new_block = saved_mask; 1247 SIGSETNAND(new_block, td->td_sigmask); 1248 td->td_sigmask = saved_mask; 1249 /* 1250 * Fewer signals can be delivered to us, reschedule signal 1251 * notification. 1252 */ 1253 if (p->p_numthreads != 1) 1254 reschedule_signals(p, new_block, 0); 1255 1256 if (error == 0) { 1257 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1258 1259 if (ksi->ksi_code == SI_TIMER) 1260 itimer_accept(p, ksi->ksi_timerid, ksi); 1261 1262 #ifdef KTRACE 1263 if (KTRPOINT(td, KTR_PSIG)) { 1264 sig_t action; 1265 1266 mtx_lock(&ps->ps_mtx); 1267 action = ps->ps_sigact[_SIG_IDX(sig)]; 1268 mtx_unlock(&ps->ps_mtx); 1269 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1270 } 1271 #endif 1272 if (sig == SIGKILL) 1273 sigexit(td, sig); 1274 } 1275 PROC_UNLOCK(p); 1276 return (error); 1277 } 1278 1279 #ifndef _SYS_SYSPROTO_H_ 1280 struct sigpending_args { 1281 sigset_t *set; 1282 }; 1283 #endif 1284 int 1285 sys_sigpending(td, uap) 1286 struct thread *td; 1287 struct sigpending_args *uap; 1288 { 1289 struct proc *p = td->td_proc; 1290 sigset_t pending; 1291 1292 PROC_LOCK(p); 1293 pending = p->p_sigqueue.sq_signals; 1294 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1295 PROC_UNLOCK(p); 1296 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1297 } 1298 1299 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1300 #ifndef _SYS_SYSPROTO_H_ 1301 struct osigpending_args { 1302 int dummy; 1303 }; 1304 #endif 1305 int 1306 osigpending(td, uap) 1307 struct thread *td; 1308 struct osigpending_args *uap; 1309 { 1310 struct proc *p = td->td_proc; 1311 sigset_t pending; 1312 1313 PROC_LOCK(p); 1314 pending = p->p_sigqueue.sq_signals; 1315 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1316 PROC_UNLOCK(p); 1317 SIG2OSIG(pending, td->td_retval[0]); 1318 return (0); 1319 } 1320 #endif /* COMPAT_43 */ 1321 1322 #if defined(COMPAT_43) 1323 /* 1324 * Generalized interface signal handler, 4.3-compatible. 1325 */ 1326 #ifndef _SYS_SYSPROTO_H_ 1327 struct osigvec_args { 1328 int signum; 1329 struct sigvec *nsv; 1330 struct sigvec *osv; 1331 }; 1332 #endif 1333 /* ARGSUSED */ 1334 int 1335 osigvec(td, uap) 1336 struct thread *td; 1337 register struct osigvec_args *uap; 1338 { 1339 struct sigvec vec; 1340 struct sigaction nsa, osa; 1341 register struct sigaction *nsap, *osap; 1342 int error; 1343 1344 if (uap->signum <= 0 || uap->signum >= ONSIG) 1345 return (EINVAL); 1346 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1347 osap = (uap->osv != NULL) ? &osa : NULL; 1348 if (nsap) { 1349 error = copyin(uap->nsv, &vec, sizeof(vec)); 1350 if (error) 1351 return (error); 1352 nsap->sa_handler = vec.sv_handler; 1353 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1354 nsap->sa_flags = vec.sv_flags; 1355 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1356 } 1357 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1358 if (osap && !error) { 1359 vec.sv_handler = osap->sa_handler; 1360 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1361 vec.sv_flags = osap->sa_flags; 1362 vec.sv_flags &= ~SA_NOCLDWAIT; 1363 vec.sv_flags ^= SA_RESTART; 1364 error = copyout(&vec, uap->osv, sizeof(vec)); 1365 } 1366 return (error); 1367 } 1368 1369 #ifndef _SYS_SYSPROTO_H_ 1370 struct osigblock_args { 1371 int mask; 1372 }; 1373 #endif 1374 int 1375 osigblock(td, uap) 1376 register struct thread *td; 1377 struct osigblock_args *uap; 1378 { 1379 sigset_t set, oset; 1380 1381 OSIG2SIG(uap->mask, set); 1382 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1383 SIG2OSIG(oset, td->td_retval[0]); 1384 return (0); 1385 } 1386 1387 #ifndef _SYS_SYSPROTO_H_ 1388 struct osigsetmask_args { 1389 int mask; 1390 }; 1391 #endif 1392 int 1393 osigsetmask(td, uap) 1394 struct thread *td; 1395 struct osigsetmask_args *uap; 1396 { 1397 sigset_t set, oset; 1398 1399 OSIG2SIG(uap->mask, set); 1400 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1401 SIG2OSIG(oset, td->td_retval[0]); 1402 return (0); 1403 } 1404 #endif /* COMPAT_43 */ 1405 1406 /* 1407 * Suspend calling thread until signal, providing mask to be set in the 1408 * meantime. 1409 */ 1410 #ifndef _SYS_SYSPROTO_H_ 1411 struct sigsuspend_args { 1412 const sigset_t *sigmask; 1413 }; 1414 #endif 1415 /* ARGSUSED */ 1416 int 1417 sys_sigsuspend(td, uap) 1418 struct thread *td; 1419 struct sigsuspend_args *uap; 1420 { 1421 sigset_t mask; 1422 int error; 1423 1424 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1425 if (error) 1426 return (error); 1427 return (kern_sigsuspend(td, mask)); 1428 } 1429 1430 int 1431 kern_sigsuspend(struct thread *td, sigset_t mask) 1432 { 1433 struct proc *p = td->td_proc; 1434 int has_sig, sig; 1435 1436 /* 1437 * When returning from sigsuspend, we want 1438 * the old mask to be restored after the 1439 * signal handler has finished. Thus, we 1440 * save it here and mark the sigacts structure 1441 * to indicate this. 1442 */ 1443 PROC_LOCK(p); 1444 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1445 SIGPROCMASK_PROC_LOCKED); 1446 td->td_pflags |= TDP_OLDMASK; 1447 1448 /* 1449 * Process signals now. Otherwise, we can get spurious wakeup 1450 * due to signal entered process queue, but delivered to other 1451 * thread. But sigsuspend should return only on signal 1452 * delivery. 1453 */ 1454 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1455 for (has_sig = 0; !has_sig;) { 1456 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1457 0) == 0) 1458 /* void */; 1459 thread_suspend_check(0); 1460 mtx_lock(&p->p_sigacts->ps_mtx); 1461 while ((sig = cursig(td)) != 0) 1462 has_sig += postsig(sig); 1463 mtx_unlock(&p->p_sigacts->ps_mtx); 1464 } 1465 PROC_UNLOCK(p); 1466 td->td_errno = EINTR; 1467 td->td_pflags |= TDP_NERRNO; 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 err; 1601 int ret; 1602 1603 ret = ESRCH; 1604 if (all) { 1605 /* 1606 * broadcast 1607 */ 1608 sx_slock(&allproc_lock); 1609 FOREACH_PROC_IN_SYSTEM(p) { 1610 PROC_LOCK(p); 1611 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1612 p == td->td_proc || p->p_state == PRS_NEW) { 1613 PROC_UNLOCK(p); 1614 continue; 1615 } 1616 err = p_cansignal(td, p, sig); 1617 if (err == 0) { 1618 if (sig) 1619 pksignal(p, sig, ksi); 1620 ret = err; 1621 } 1622 else if (ret == ESRCH) 1623 ret = err; 1624 PROC_UNLOCK(p); 1625 } 1626 sx_sunlock(&allproc_lock); 1627 } else { 1628 sx_slock(&proctree_lock); 1629 if (pgid == 0) { 1630 /* 1631 * zero pgid means send to my process group. 1632 */ 1633 pgrp = td->td_proc->p_pgrp; 1634 PGRP_LOCK(pgrp); 1635 } else { 1636 pgrp = pgfind(pgid); 1637 if (pgrp == NULL) { 1638 sx_sunlock(&proctree_lock); 1639 return (ESRCH); 1640 } 1641 } 1642 sx_sunlock(&proctree_lock); 1643 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1644 PROC_LOCK(p); 1645 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1646 p->p_state == PRS_NEW) { 1647 PROC_UNLOCK(p); 1648 continue; 1649 } 1650 err = p_cansignal(td, p, sig); 1651 if (err == 0) { 1652 if (sig) 1653 pksignal(p, sig, ksi); 1654 ret = err; 1655 } 1656 else if (ret == ESRCH) 1657 ret = err; 1658 PROC_UNLOCK(p); 1659 } 1660 PGRP_UNLOCK(pgrp); 1661 } 1662 return (ret); 1663 } 1664 1665 #ifndef _SYS_SYSPROTO_H_ 1666 struct kill_args { 1667 int pid; 1668 int signum; 1669 }; 1670 #endif 1671 /* ARGSUSED */ 1672 int 1673 sys_kill(struct thread *td, struct kill_args *uap) 1674 { 1675 ksiginfo_t ksi; 1676 struct proc *p; 1677 int error; 1678 1679 /* 1680 * A process in capability mode can send signals only to himself. 1681 * The main rationale behind this is that abort(3) is implemented as 1682 * kill(getpid(), SIGABRT). 1683 */ 1684 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1685 return (ECAPMODE); 1686 1687 AUDIT_ARG_SIGNUM(uap->signum); 1688 AUDIT_ARG_PID(uap->pid); 1689 if ((u_int)uap->signum > _SIG_MAXSIG) 1690 return (EINVAL); 1691 1692 ksiginfo_init(&ksi); 1693 ksi.ksi_signo = uap->signum; 1694 ksi.ksi_code = SI_USER; 1695 ksi.ksi_pid = td->td_proc->p_pid; 1696 ksi.ksi_uid = td->td_ucred->cr_ruid; 1697 1698 if (uap->pid > 0) { 1699 /* kill single process */ 1700 if ((p = pfind(uap->pid)) == NULL) { 1701 if ((p = zpfind(uap->pid)) == NULL) 1702 return (ESRCH); 1703 } 1704 AUDIT_ARG_PROCESS(p); 1705 error = p_cansignal(td, p, uap->signum); 1706 if (error == 0 && uap->signum) 1707 pksignal(p, uap->signum, &ksi); 1708 PROC_UNLOCK(p); 1709 return (error); 1710 } 1711 switch (uap->pid) { 1712 case -1: /* broadcast signal */ 1713 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1714 case 0: /* signal own process group */ 1715 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1716 default: /* negative explicit process group */ 1717 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1718 } 1719 /* NOTREACHED */ 1720 } 1721 1722 int 1723 sys_pdkill(td, uap) 1724 struct thread *td; 1725 struct pdkill_args *uap; 1726 { 1727 #ifdef PROCDESC 1728 struct proc *p; 1729 cap_rights_t rights; 1730 int error; 1731 1732 AUDIT_ARG_SIGNUM(uap->signum); 1733 AUDIT_ARG_FD(uap->fd); 1734 if ((u_int)uap->signum > _SIG_MAXSIG) 1735 return (EINVAL); 1736 1737 error = procdesc_find(td, uap->fd, 1738 cap_rights_init(&rights, CAP_PDKILL), &p); 1739 if (error) 1740 return (error); 1741 AUDIT_ARG_PROCESS(p); 1742 error = p_cansignal(td, p, uap->signum); 1743 if (error == 0 && uap->signum) 1744 kern_psignal(p, uap->signum); 1745 PROC_UNLOCK(p); 1746 return (error); 1747 #else 1748 return (ENOSYS); 1749 #endif 1750 } 1751 1752 #if defined(COMPAT_43) 1753 #ifndef _SYS_SYSPROTO_H_ 1754 struct okillpg_args { 1755 int pgid; 1756 int signum; 1757 }; 1758 #endif 1759 /* ARGSUSED */ 1760 int 1761 okillpg(struct thread *td, struct okillpg_args *uap) 1762 { 1763 ksiginfo_t ksi; 1764 1765 AUDIT_ARG_SIGNUM(uap->signum); 1766 AUDIT_ARG_PID(uap->pgid); 1767 if ((u_int)uap->signum > _SIG_MAXSIG) 1768 return (EINVAL); 1769 1770 ksiginfo_init(&ksi); 1771 ksi.ksi_signo = uap->signum; 1772 ksi.ksi_code = SI_USER; 1773 ksi.ksi_pid = td->td_proc->p_pid; 1774 ksi.ksi_uid = td->td_ucred->cr_ruid; 1775 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1776 } 1777 #endif /* COMPAT_43 */ 1778 1779 #ifndef _SYS_SYSPROTO_H_ 1780 struct sigqueue_args { 1781 pid_t pid; 1782 int signum; 1783 /* union sigval */ void *value; 1784 }; 1785 #endif 1786 int 1787 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1788 { 1789 ksiginfo_t ksi; 1790 struct proc *p; 1791 int error; 1792 1793 if ((u_int)uap->signum > _SIG_MAXSIG) 1794 return (EINVAL); 1795 1796 /* 1797 * Specification says sigqueue can only send signal to 1798 * single process. 1799 */ 1800 if (uap->pid <= 0) 1801 return (EINVAL); 1802 1803 if ((p = pfind(uap->pid)) == NULL) { 1804 if ((p = zpfind(uap->pid)) == NULL) 1805 return (ESRCH); 1806 } 1807 error = p_cansignal(td, p, uap->signum); 1808 if (error == 0 && uap->signum != 0) { 1809 ksiginfo_init(&ksi); 1810 ksi.ksi_flags = KSI_SIGQ; 1811 ksi.ksi_signo = uap->signum; 1812 ksi.ksi_code = SI_QUEUE; 1813 ksi.ksi_pid = td->td_proc->p_pid; 1814 ksi.ksi_uid = td->td_ucred->cr_ruid; 1815 ksi.ksi_value.sival_ptr = uap->value; 1816 error = pksignal(p, ksi.ksi_signo, &ksi); 1817 } 1818 PROC_UNLOCK(p); 1819 return (error); 1820 } 1821 1822 /* 1823 * Send a signal to a process group. 1824 */ 1825 void 1826 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1827 { 1828 struct pgrp *pgrp; 1829 1830 if (pgid != 0) { 1831 sx_slock(&proctree_lock); 1832 pgrp = pgfind(pgid); 1833 sx_sunlock(&proctree_lock); 1834 if (pgrp != NULL) { 1835 pgsignal(pgrp, sig, 0, ksi); 1836 PGRP_UNLOCK(pgrp); 1837 } 1838 } 1839 } 1840 1841 /* 1842 * Send a signal to a process group. If checktty is 1, 1843 * limit to members which have a controlling terminal. 1844 */ 1845 void 1846 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1847 { 1848 struct proc *p; 1849 1850 if (pgrp) { 1851 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1852 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1853 PROC_LOCK(p); 1854 if (p->p_state == PRS_NORMAL && 1855 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1856 pksignal(p, sig, ksi); 1857 PROC_UNLOCK(p); 1858 } 1859 } 1860 } 1861 1862 /* 1863 * Send a signal caused by a trap to the current thread. If it will be 1864 * caught immediately, deliver it with correct code. Otherwise, post it 1865 * normally. 1866 */ 1867 void 1868 trapsignal(struct thread *td, ksiginfo_t *ksi) 1869 { 1870 struct sigacts *ps; 1871 sigset_t mask; 1872 struct proc *p; 1873 int sig; 1874 int code; 1875 1876 p = td->td_proc; 1877 sig = ksi->ksi_signo; 1878 code = ksi->ksi_code; 1879 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1880 1881 PROC_LOCK(p); 1882 ps = p->p_sigacts; 1883 mtx_lock(&ps->ps_mtx); 1884 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1885 !SIGISMEMBER(td->td_sigmask, sig)) { 1886 td->td_ru.ru_nsignals++; 1887 #ifdef KTRACE 1888 if (KTRPOINT(curthread, KTR_PSIG)) 1889 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1890 &td->td_sigmask, code); 1891 #endif 1892 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1893 ksi, &td->td_sigmask); 1894 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1895 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1896 SIGADDSET(mask, sig); 1897 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1898 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1899 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1900 /* 1901 * See kern_sigaction() for origin of this code. 1902 */ 1903 SIGDELSET(ps->ps_sigcatch, sig); 1904 if (sig != SIGCONT && 1905 sigprop(sig) & SA_IGNORE) 1906 SIGADDSET(ps->ps_sigignore, sig); 1907 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1908 } 1909 mtx_unlock(&ps->ps_mtx); 1910 } else { 1911 /* 1912 * Avoid a possible infinite loop if the thread 1913 * masking the signal or process is ignoring the 1914 * signal. 1915 */ 1916 if (kern_forcesigexit && 1917 (SIGISMEMBER(td->td_sigmask, sig) || 1918 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1919 SIGDELSET(td->td_sigmask, sig); 1920 SIGDELSET(ps->ps_sigcatch, sig); 1921 SIGDELSET(ps->ps_sigignore, sig); 1922 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1923 } 1924 mtx_unlock(&ps->ps_mtx); 1925 p->p_code = code; /* XXX for core dump/debugger */ 1926 p->p_sig = sig; /* XXX to verify code */ 1927 tdsendsignal(p, td, sig, ksi); 1928 } 1929 PROC_UNLOCK(p); 1930 } 1931 1932 static struct thread * 1933 sigtd(struct proc *p, int sig, int prop) 1934 { 1935 struct thread *td, *signal_td; 1936 1937 PROC_LOCK_ASSERT(p, MA_OWNED); 1938 1939 /* 1940 * Check if current thread can handle the signal without 1941 * switching context to another thread. 1942 */ 1943 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1944 return (curthread); 1945 signal_td = NULL; 1946 FOREACH_THREAD_IN_PROC(p, td) { 1947 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1948 signal_td = td; 1949 break; 1950 } 1951 } 1952 if (signal_td == NULL) 1953 signal_td = FIRST_THREAD_IN_PROC(p); 1954 return (signal_td); 1955 } 1956 1957 /* 1958 * Send the signal to the process. If the signal has an action, the action 1959 * is usually performed by the target process rather than the caller; we add 1960 * the signal to the set of pending signals for the process. 1961 * 1962 * Exceptions: 1963 * o When a stop signal is sent to a sleeping process that takes the 1964 * default action, the process is stopped without awakening it. 1965 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1966 * regardless of the signal action (eg, blocked or ignored). 1967 * 1968 * Other ignored signals are discarded immediately. 1969 * 1970 * NB: This function may be entered from the debugger via the "kill" DDB 1971 * command. There is little that can be done to mitigate the possibly messy 1972 * side effects of this unwise possibility. 1973 */ 1974 void 1975 kern_psignal(struct proc *p, int sig) 1976 { 1977 ksiginfo_t ksi; 1978 1979 ksiginfo_init(&ksi); 1980 ksi.ksi_signo = sig; 1981 ksi.ksi_code = SI_KERNEL; 1982 (void) tdsendsignal(p, NULL, sig, &ksi); 1983 } 1984 1985 int 1986 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1987 { 1988 1989 return (tdsendsignal(p, NULL, sig, ksi)); 1990 } 1991 1992 /* Utility function for finding a thread to send signal event to. */ 1993 int 1994 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1995 { 1996 struct thread *td; 1997 1998 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1999 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2000 if (td == NULL) 2001 return (ESRCH); 2002 *ttd = td; 2003 } else { 2004 *ttd = NULL; 2005 PROC_LOCK(p); 2006 } 2007 return (0); 2008 } 2009 2010 void 2011 tdsignal(struct thread *td, int sig) 2012 { 2013 ksiginfo_t ksi; 2014 2015 ksiginfo_init(&ksi); 2016 ksi.ksi_signo = sig; 2017 ksi.ksi_code = SI_KERNEL; 2018 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2019 } 2020 2021 void 2022 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2023 { 2024 2025 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2026 } 2027 2028 int 2029 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2030 { 2031 sig_t action; 2032 sigqueue_t *sigqueue; 2033 int prop; 2034 struct sigacts *ps; 2035 int intrval; 2036 int ret = 0; 2037 int wakeup_swapper; 2038 2039 MPASS(td == NULL || p == td->td_proc); 2040 PROC_LOCK_ASSERT(p, MA_OWNED); 2041 2042 if (!_SIG_VALID(sig)) 2043 panic("%s(): invalid signal %d", __func__, sig); 2044 2045 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2046 2047 /* 2048 * IEEE Std 1003.1-2001: return success when killing a zombie. 2049 */ 2050 if (p->p_state == PRS_ZOMBIE) { 2051 if (ksi && (ksi->ksi_flags & KSI_INS)) 2052 ksiginfo_tryfree(ksi); 2053 return (ret); 2054 } 2055 2056 ps = p->p_sigacts; 2057 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2058 prop = sigprop(sig); 2059 2060 if (td == NULL) { 2061 td = sigtd(p, sig, prop); 2062 sigqueue = &p->p_sigqueue; 2063 } else 2064 sigqueue = &td->td_sigqueue; 2065 2066 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2067 2068 /* 2069 * If the signal is being ignored, 2070 * then we forget about it immediately. 2071 * (Note: we don't set SIGCONT in ps_sigignore, 2072 * and if it is set to SIG_IGN, 2073 * action will be SIG_DFL here.) 2074 */ 2075 mtx_lock(&ps->ps_mtx); 2076 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2077 SDT_PROBE(proc, kernel, , signal_discard, td, p, sig, 0, 0 ); 2078 2079 mtx_unlock(&ps->ps_mtx); 2080 if (ksi && (ksi->ksi_flags & KSI_INS)) 2081 ksiginfo_tryfree(ksi); 2082 return (ret); 2083 } 2084 if (SIGISMEMBER(td->td_sigmask, sig)) 2085 action = SIG_HOLD; 2086 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2087 action = SIG_CATCH; 2088 else 2089 action = SIG_DFL; 2090 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2091 intrval = EINTR; 2092 else 2093 intrval = ERESTART; 2094 mtx_unlock(&ps->ps_mtx); 2095 2096 if (prop & SA_CONT) 2097 sigqueue_delete_stopmask_proc(p); 2098 else if (prop & SA_STOP) { 2099 /* 2100 * If sending a tty stop signal to a member of an orphaned 2101 * process group, discard the signal here if the action 2102 * is default; don't stop the process below if sleeping, 2103 * and don't clear any pending SIGCONT. 2104 */ 2105 if ((prop & SA_TTYSTOP) && 2106 (p->p_pgrp->pg_jobc == 0) && 2107 (action == SIG_DFL)) { 2108 if (ksi && (ksi->ksi_flags & KSI_INS)) 2109 ksiginfo_tryfree(ksi); 2110 return (ret); 2111 } 2112 sigqueue_delete_proc(p, SIGCONT); 2113 if (p->p_flag & P_CONTINUED) { 2114 p->p_flag &= ~P_CONTINUED; 2115 PROC_LOCK(p->p_pptr); 2116 sigqueue_take(p->p_ksi); 2117 PROC_UNLOCK(p->p_pptr); 2118 } 2119 } 2120 2121 ret = sigqueue_add(sigqueue, sig, ksi); 2122 if (ret != 0) 2123 return (ret); 2124 signotify(td); 2125 /* 2126 * Defer further processing for signals which are held, 2127 * except that stopped processes must be continued by SIGCONT. 2128 */ 2129 if (action == SIG_HOLD && 2130 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2131 return (ret); 2132 /* 2133 * SIGKILL: Remove procfs STOPEVENTs. 2134 */ 2135 if (sig == SIGKILL) { 2136 /* from procfs_ioctl.c: PIOCBIC */ 2137 p->p_stops = 0; 2138 /* from procfs_ioctl.c: PIOCCONT */ 2139 p->p_step = 0; 2140 wakeup(&p->p_step); 2141 } 2142 /* 2143 * Some signals have a process-wide effect and a per-thread 2144 * component. Most processing occurs when the process next 2145 * tries to cross the user boundary, however there are some 2146 * times when processing needs to be done immediately, such as 2147 * waking up threads so that they can cross the user boundary. 2148 * We try to do the per-process part here. 2149 */ 2150 if (P_SHOULDSTOP(p)) { 2151 KASSERT(!(p->p_flag & P_WEXIT), 2152 ("signal to stopped but exiting process")); 2153 if (sig == SIGKILL) { 2154 /* 2155 * If traced process is already stopped, 2156 * then no further action is necessary. 2157 */ 2158 if (p->p_flag & P_TRACED) 2159 goto out; 2160 /* 2161 * SIGKILL sets process running. 2162 * It will die elsewhere. 2163 * All threads must be restarted. 2164 */ 2165 p->p_flag &= ~P_STOPPED_SIG; 2166 goto runfast; 2167 } 2168 2169 if (prop & SA_CONT) { 2170 /* 2171 * If traced process is already stopped, 2172 * then no further action is necessary. 2173 */ 2174 if (p->p_flag & P_TRACED) 2175 goto out; 2176 /* 2177 * If SIGCONT is default (or ignored), we continue the 2178 * process but don't leave the signal in sigqueue as 2179 * it has no further action. If SIGCONT is held, we 2180 * continue the process and leave the signal in 2181 * sigqueue. If the process catches SIGCONT, let it 2182 * handle the signal itself. If it isn't waiting on 2183 * an event, it goes back to run state. 2184 * Otherwise, process goes back to sleep state. 2185 */ 2186 p->p_flag &= ~P_STOPPED_SIG; 2187 PROC_SLOCK(p); 2188 if (p->p_numthreads == p->p_suspcount) { 2189 PROC_SUNLOCK(p); 2190 p->p_flag |= P_CONTINUED; 2191 p->p_xstat = SIGCONT; 2192 PROC_LOCK(p->p_pptr); 2193 childproc_continued(p); 2194 PROC_UNLOCK(p->p_pptr); 2195 PROC_SLOCK(p); 2196 } 2197 if (action == SIG_DFL) { 2198 thread_unsuspend(p); 2199 PROC_SUNLOCK(p); 2200 sigqueue_delete(sigqueue, sig); 2201 goto out; 2202 } 2203 if (action == SIG_CATCH) { 2204 /* 2205 * The process wants to catch it so it needs 2206 * to run at least one thread, but which one? 2207 */ 2208 PROC_SUNLOCK(p); 2209 goto runfast; 2210 } 2211 /* 2212 * The signal is not ignored or caught. 2213 */ 2214 thread_unsuspend(p); 2215 PROC_SUNLOCK(p); 2216 goto out; 2217 } 2218 2219 if (prop & SA_STOP) { 2220 /* 2221 * If traced process is already stopped, 2222 * then no further action is necessary. 2223 */ 2224 if (p->p_flag & P_TRACED) 2225 goto out; 2226 /* 2227 * Already stopped, don't need to stop again 2228 * (If we did the shell could get confused). 2229 * Just make sure the signal STOP bit set. 2230 */ 2231 p->p_flag |= P_STOPPED_SIG; 2232 sigqueue_delete(sigqueue, sig); 2233 goto out; 2234 } 2235 2236 /* 2237 * All other kinds of signals: 2238 * If a thread is sleeping interruptibly, simulate a 2239 * wakeup so that when it is continued it will be made 2240 * runnable and can look at the signal. However, don't make 2241 * the PROCESS runnable, leave it stopped. 2242 * It may run a bit until it hits a thread_suspend_check(). 2243 */ 2244 wakeup_swapper = 0; 2245 PROC_SLOCK(p); 2246 thread_lock(td); 2247 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2248 wakeup_swapper = sleepq_abort(td, intrval); 2249 thread_unlock(td); 2250 PROC_SUNLOCK(p); 2251 if (wakeup_swapper) 2252 kick_proc0(); 2253 goto out; 2254 /* 2255 * Mutexes are short lived. Threads waiting on them will 2256 * hit thread_suspend_check() soon. 2257 */ 2258 } else if (p->p_state == PRS_NORMAL) { 2259 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2260 tdsigwakeup(td, sig, action, intrval); 2261 goto out; 2262 } 2263 2264 MPASS(action == SIG_DFL); 2265 2266 if (prop & SA_STOP) { 2267 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2268 goto out; 2269 p->p_flag |= P_STOPPED_SIG; 2270 p->p_xstat = sig; 2271 PROC_SLOCK(p); 2272 sig_suspend_threads(td, p, 1); 2273 if (p->p_numthreads == p->p_suspcount) { 2274 /* 2275 * only thread sending signal to another 2276 * process can reach here, if thread is sending 2277 * signal to its process, because thread does 2278 * not suspend itself here, p_numthreads 2279 * should never be equal to p_suspcount. 2280 */ 2281 thread_stopped(p); 2282 PROC_SUNLOCK(p); 2283 sigqueue_delete_proc(p, p->p_xstat); 2284 } else 2285 PROC_SUNLOCK(p); 2286 goto out; 2287 } 2288 } else { 2289 /* Not in "NORMAL" state. discard the signal. */ 2290 sigqueue_delete(sigqueue, sig); 2291 goto out; 2292 } 2293 2294 /* 2295 * The process is not stopped so we need to apply the signal to all the 2296 * running threads. 2297 */ 2298 runfast: 2299 tdsigwakeup(td, sig, action, intrval); 2300 PROC_SLOCK(p); 2301 thread_unsuspend(p); 2302 PROC_SUNLOCK(p); 2303 out: 2304 /* If we jump here, proc slock should not be owned. */ 2305 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2306 return (ret); 2307 } 2308 2309 /* 2310 * The force of a signal has been directed against a single 2311 * thread. We need to see what we can do about knocking it 2312 * out of any sleep it may be in etc. 2313 */ 2314 static void 2315 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2316 { 2317 struct proc *p = td->td_proc; 2318 register int prop; 2319 int wakeup_swapper; 2320 2321 wakeup_swapper = 0; 2322 PROC_LOCK_ASSERT(p, MA_OWNED); 2323 prop = sigprop(sig); 2324 2325 PROC_SLOCK(p); 2326 thread_lock(td); 2327 /* 2328 * Bring the priority of a thread up if we want it to get 2329 * killed in this lifetime. 2330 */ 2331 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2332 sched_prio(td, PUSER); 2333 if (TD_ON_SLEEPQ(td)) { 2334 /* 2335 * If thread is sleeping uninterruptibly 2336 * we can't interrupt the sleep... the signal will 2337 * be noticed when the process returns through 2338 * trap() or syscall(). 2339 */ 2340 if ((td->td_flags & TDF_SINTR) == 0) 2341 goto out; 2342 /* 2343 * If SIGCONT is default (or ignored) and process is 2344 * asleep, we are finished; the process should not 2345 * be awakened. 2346 */ 2347 if ((prop & SA_CONT) && action == SIG_DFL) { 2348 thread_unlock(td); 2349 PROC_SUNLOCK(p); 2350 sigqueue_delete(&p->p_sigqueue, sig); 2351 /* 2352 * It may be on either list in this state. 2353 * Remove from both for now. 2354 */ 2355 sigqueue_delete(&td->td_sigqueue, sig); 2356 return; 2357 } 2358 2359 /* 2360 * Don't awaken a sleeping thread for SIGSTOP if the 2361 * STOP signal is deferred. 2362 */ 2363 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2364 goto out; 2365 2366 /* 2367 * Give low priority threads a better chance to run. 2368 */ 2369 if (td->td_priority > PUSER) 2370 sched_prio(td, PUSER); 2371 2372 wakeup_swapper = sleepq_abort(td, intrval); 2373 } else { 2374 /* 2375 * Other states do nothing with the signal immediately, 2376 * other than kicking ourselves if we are running. 2377 * It will either never be noticed, or noticed very soon. 2378 */ 2379 #ifdef SMP 2380 if (TD_IS_RUNNING(td) && td != curthread) 2381 forward_signal(td); 2382 #endif 2383 } 2384 out: 2385 PROC_SUNLOCK(p); 2386 thread_unlock(td); 2387 if (wakeup_swapper) 2388 kick_proc0(); 2389 } 2390 2391 static void 2392 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2393 { 2394 struct thread *td2; 2395 2396 PROC_LOCK_ASSERT(p, MA_OWNED); 2397 PROC_SLOCK_ASSERT(p, MA_OWNED); 2398 2399 FOREACH_THREAD_IN_PROC(p, td2) { 2400 thread_lock(td2); 2401 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2402 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2403 (td2->td_flags & TDF_SINTR)) { 2404 if (td2->td_flags & TDF_SBDRY) { 2405 /* 2406 * Once a thread is asleep with 2407 * TDF_SBDRY set, it should never 2408 * become suspended due to this check. 2409 */ 2410 KASSERT(!TD_IS_SUSPENDED(td2), 2411 ("thread with deferred stops suspended")); 2412 } else if (!TD_IS_SUSPENDED(td2)) { 2413 thread_suspend_one(td2); 2414 } 2415 } else if (!TD_IS_SUSPENDED(td2)) { 2416 if (sending || td != td2) 2417 td2->td_flags |= TDF_ASTPENDING; 2418 #ifdef SMP 2419 if (TD_IS_RUNNING(td2) && td2 != td) 2420 forward_signal(td2); 2421 #endif 2422 } 2423 thread_unlock(td2); 2424 } 2425 } 2426 2427 int 2428 ptracestop(struct thread *td, int sig) 2429 { 2430 struct proc *p = td->td_proc; 2431 2432 PROC_LOCK_ASSERT(p, MA_OWNED); 2433 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2434 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2435 &p->p_mtx.lock_object, "Stopping for traced signal"); 2436 2437 td->td_dbgflags |= TDB_XSIG; 2438 td->td_xsig = sig; 2439 PROC_SLOCK(p); 2440 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2441 if (p->p_flag & P_SINGLE_EXIT) { 2442 td->td_dbgflags &= ~TDB_XSIG; 2443 PROC_SUNLOCK(p); 2444 return (sig); 2445 } 2446 /* 2447 * Just make wait() to work, the last stopped thread 2448 * will win. 2449 */ 2450 p->p_xstat = sig; 2451 p->p_xthread = td; 2452 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2453 sig_suspend_threads(td, p, 0); 2454 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2455 td->td_dbgflags &= ~TDB_STOPATFORK; 2456 cv_broadcast(&p->p_dbgwait); 2457 } 2458 stopme: 2459 thread_suspend_switch(td); 2460 if (p->p_xthread == td) 2461 p->p_xthread = NULL; 2462 if (!(p->p_flag & P_TRACED)) 2463 break; 2464 if (td->td_dbgflags & TDB_SUSPEND) { 2465 if (p->p_flag & P_SINGLE_EXIT) 2466 break; 2467 goto stopme; 2468 } 2469 } 2470 PROC_SUNLOCK(p); 2471 return (td->td_xsig); 2472 } 2473 2474 static void 2475 reschedule_signals(struct proc *p, sigset_t block, int flags) 2476 { 2477 struct sigacts *ps; 2478 struct thread *td; 2479 int sig; 2480 2481 PROC_LOCK_ASSERT(p, MA_OWNED); 2482 if (SIGISEMPTY(p->p_siglist)) 2483 return; 2484 ps = p->p_sigacts; 2485 SIGSETAND(block, p->p_siglist); 2486 while ((sig = sig_ffs(&block)) != 0) { 2487 SIGDELSET(block, sig); 2488 td = sigtd(p, sig, 0); 2489 signotify(td); 2490 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2491 mtx_lock(&ps->ps_mtx); 2492 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2493 tdsigwakeup(td, sig, SIG_CATCH, 2494 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2495 ERESTART)); 2496 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2497 mtx_unlock(&ps->ps_mtx); 2498 } 2499 } 2500 2501 void 2502 tdsigcleanup(struct thread *td) 2503 { 2504 struct proc *p; 2505 sigset_t unblocked; 2506 2507 p = td->td_proc; 2508 PROC_LOCK_ASSERT(p, MA_OWNED); 2509 2510 sigqueue_flush(&td->td_sigqueue); 2511 if (p->p_numthreads == 1) 2512 return; 2513 2514 /* 2515 * Since we cannot handle signals, notify signal post code 2516 * about this by filling the sigmask. 2517 * 2518 * Also, if needed, wake up thread(s) that do not block the 2519 * same signals as the exiting thread, since the thread might 2520 * have been selected for delivery and woken up. 2521 */ 2522 SIGFILLSET(unblocked); 2523 SIGSETNAND(unblocked, td->td_sigmask); 2524 SIGFILLSET(td->td_sigmask); 2525 reschedule_signals(p, unblocked, 0); 2526 2527 } 2528 2529 /* 2530 * Defer the delivery of SIGSTOP for the current thread. Returns true 2531 * if stops were deferred and false if they were already deferred. 2532 */ 2533 int 2534 sigdeferstop(void) 2535 { 2536 struct thread *td; 2537 2538 td = curthread; 2539 if (td->td_flags & TDF_SBDRY) 2540 return (0); 2541 thread_lock(td); 2542 td->td_flags |= TDF_SBDRY; 2543 thread_unlock(td); 2544 return (1); 2545 } 2546 2547 /* 2548 * Permit the delivery of SIGSTOP for the current thread. This does 2549 * not immediately suspend if a stop was posted. Instead, the thread 2550 * will suspend either via ast() or a subsequent interruptible sleep. 2551 */ 2552 void 2553 sigallowstop() 2554 { 2555 struct thread *td; 2556 2557 td = curthread; 2558 thread_lock(td); 2559 td->td_flags &= ~TDF_SBDRY; 2560 thread_unlock(td); 2561 } 2562 2563 /* 2564 * If the current process has received a signal (should be caught or cause 2565 * termination, should interrupt current syscall), return the signal number. 2566 * Stop signals with default action are processed immediately, then cleared; 2567 * they aren't returned. This is checked after each entry to the system for 2568 * a syscall or trap (though this can usually be done without calling issignal 2569 * by checking the pending signal masks in cursig.) The normal call 2570 * sequence is 2571 * 2572 * while (sig = cursig(curthread)) 2573 * postsig(sig); 2574 */ 2575 static int 2576 issignal(struct thread *td) 2577 { 2578 struct proc *p; 2579 struct sigacts *ps; 2580 struct sigqueue *queue; 2581 sigset_t sigpending; 2582 int sig, prop, newsig; 2583 2584 p = td->td_proc; 2585 ps = p->p_sigacts; 2586 mtx_assert(&ps->ps_mtx, MA_OWNED); 2587 PROC_LOCK_ASSERT(p, MA_OWNED); 2588 for (;;) { 2589 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2590 2591 sigpending = td->td_sigqueue.sq_signals; 2592 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2593 SIGSETNAND(sigpending, td->td_sigmask); 2594 2595 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2596 SIG_STOPSIGMASK(sigpending); 2597 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2598 return (0); 2599 sig = sig_ffs(&sigpending); 2600 2601 if (p->p_stops & S_SIG) { 2602 mtx_unlock(&ps->ps_mtx); 2603 stopevent(p, S_SIG, sig); 2604 mtx_lock(&ps->ps_mtx); 2605 } 2606 2607 /* 2608 * We should see pending but ignored signals 2609 * only if P_TRACED was on when they were posted. 2610 */ 2611 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2612 sigqueue_delete(&td->td_sigqueue, sig); 2613 sigqueue_delete(&p->p_sigqueue, sig); 2614 continue; 2615 } 2616 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2617 /* 2618 * If traced, always stop. 2619 * Remove old signal from queue before the stop. 2620 * XXX shrug off debugger, it causes siginfo to 2621 * be thrown away. 2622 */ 2623 queue = &td->td_sigqueue; 2624 td->td_dbgksi.ksi_signo = 0; 2625 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2626 queue = &p->p_sigqueue; 2627 sigqueue_get(queue, sig, &td->td_dbgksi); 2628 } 2629 2630 mtx_unlock(&ps->ps_mtx); 2631 newsig = ptracestop(td, sig); 2632 mtx_lock(&ps->ps_mtx); 2633 2634 if (sig != newsig) { 2635 2636 /* 2637 * If parent wants us to take the signal, 2638 * then it will leave it in p->p_xstat; 2639 * otherwise we just look for signals again. 2640 */ 2641 if (newsig == 0) 2642 continue; 2643 sig = newsig; 2644 2645 /* 2646 * Put the new signal into td_sigqueue. If the 2647 * signal is being masked, look for other 2648 * signals. 2649 */ 2650 sigqueue_add(queue, sig, NULL); 2651 if (SIGISMEMBER(td->td_sigmask, sig)) 2652 continue; 2653 signotify(td); 2654 } else { 2655 if (td->td_dbgksi.ksi_signo != 0) { 2656 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2657 if (sigqueue_add(&td->td_sigqueue, sig, 2658 &td->td_dbgksi) != 0) 2659 td->td_dbgksi.ksi_signo = 0; 2660 } 2661 if (td->td_dbgksi.ksi_signo == 0) 2662 sigqueue_add(&td->td_sigqueue, sig, 2663 NULL); 2664 } 2665 2666 /* 2667 * If the traced bit got turned off, go back up 2668 * to the top to rescan signals. This ensures 2669 * that p_sig* and p_sigact are consistent. 2670 */ 2671 if ((p->p_flag & P_TRACED) == 0) 2672 continue; 2673 } 2674 2675 prop = sigprop(sig); 2676 2677 /* 2678 * Decide whether the signal should be returned. 2679 * Return the signal's number, or fall through 2680 * to clear it from the pending mask. 2681 */ 2682 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2683 2684 case (intptr_t)SIG_DFL: 2685 /* 2686 * Don't take default actions on system processes. 2687 */ 2688 if (p->p_pid <= 1) { 2689 #ifdef DIAGNOSTIC 2690 /* 2691 * Are you sure you want to ignore SIGSEGV 2692 * in init? XXX 2693 */ 2694 printf("Process (pid %lu) got signal %d\n", 2695 (u_long)p->p_pid, sig); 2696 #endif 2697 break; /* == ignore */ 2698 } 2699 /* 2700 * If there is a pending stop signal to process 2701 * with default action, stop here, 2702 * then clear the signal. However, 2703 * if process is member of an orphaned 2704 * process group, ignore tty stop signals. 2705 */ 2706 if (prop & SA_STOP) { 2707 if (p->p_flag & (P_TRACED|P_WEXIT) || 2708 (p->p_pgrp->pg_jobc == 0 && 2709 prop & SA_TTYSTOP)) 2710 break; /* == ignore */ 2711 mtx_unlock(&ps->ps_mtx); 2712 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2713 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2714 p->p_flag |= P_STOPPED_SIG; 2715 p->p_xstat = sig; 2716 PROC_SLOCK(p); 2717 sig_suspend_threads(td, p, 0); 2718 thread_suspend_switch(td); 2719 PROC_SUNLOCK(p); 2720 mtx_lock(&ps->ps_mtx); 2721 break; 2722 } else if (prop & SA_IGNORE) { 2723 /* 2724 * Except for SIGCONT, shouldn't get here. 2725 * Default action is to ignore; drop it. 2726 */ 2727 break; /* == ignore */ 2728 } else 2729 return (sig); 2730 /*NOTREACHED*/ 2731 2732 case (intptr_t)SIG_IGN: 2733 /* 2734 * Masking above should prevent us ever trying 2735 * to take action on an ignored signal other 2736 * than SIGCONT, unless process is traced. 2737 */ 2738 if ((prop & SA_CONT) == 0 && 2739 (p->p_flag & P_TRACED) == 0) 2740 printf("issignal\n"); 2741 break; /* == ignore */ 2742 2743 default: 2744 /* 2745 * This signal has an action, let 2746 * postsig() process it. 2747 */ 2748 return (sig); 2749 } 2750 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2751 sigqueue_delete(&p->p_sigqueue, sig); 2752 } 2753 /* NOTREACHED */ 2754 } 2755 2756 void 2757 thread_stopped(struct proc *p) 2758 { 2759 int n; 2760 2761 PROC_LOCK_ASSERT(p, MA_OWNED); 2762 PROC_SLOCK_ASSERT(p, MA_OWNED); 2763 n = p->p_suspcount; 2764 if (p == curproc) 2765 n++; 2766 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2767 PROC_SUNLOCK(p); 2768 p->p_flag &= ~P_WAITED; 2769 PROC_LOCK(p->p_pptr); 2770 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2771 CLD_TRAPPED : CLD_STOPPED); 2772 PROC_UNLOCK(p->p_pptr); 2773 PROC_SLOCK(p); 2774 } 2775 } 2776 2777 /* 2778 * Take the action for the specified signal 2779 * from the current set of pending signals. 2780 */ 2781 int 2782 postsig(sig) 2783 register int sig; 2784 { 2785 struct thread *td = curthread; 2786 register struct proc *p = td->td_proc; 2787 struct sigacts *ps; 2788 sig_t action; 2789 ksiginfo_t ksi; 2790 sigset_t returnmask, mask; 2791 2792 KASSERT(sig != 0, ("postsig")); 2793 2794 PROC_LOCK_ASSERT(p, MA_OWNED); 2795 ps = p->p_sigacts; 2796 mtx_assert(&ps->ps_mtx, MA_OWNED); 2797 ksiginfo_init(&ksi); 2798 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2799 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2800 return (0); 2801 ksi.ksi_signo = sig; 2802 if (ksi.ksi_code == SI_TIMER) 2803 itimer_accept(p, ksi.ksi_timerid, &ksi); 2804 action = ps->ps_sigact[_SIG_IDX(sig)]; 2805 #ifdef KTRACE 2806 if (KTRPOINT(td, KTR_PSIG)) 2807 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2808 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2809 #endif 2810 if (p->p_stops & S_SIG) { 2811 mtx_unlock(&ps->ps_mtx); 2812 stopevent(p, S_SIG, sig); 2813 mtx_lock(&ps->ps_mtx); 2814 } 2815 2816 if (action == SIG_DFL) { 2817 /* 2818 * Default action, where the default is to kill 2819 * the process. (Other cases were ignored above.) 2820 */ 2821 mtx_unlock(&ps->ps_mtx); 2822 sigexit(td, sig); 2823 /* NOTREACHED */ 2824 } else { 2825 /* 2826 * If we get here, the signal must be caught. 2827 */ 2828 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2829 ("postsig action")); 2830 /* 2831 * Set the new mask value and also defer further 2832 * occurrences of this signal. 2833 * 2834 * Special case: user has done a sigsuspend. Here the 2835 * current mask is not of interest, but rather the 2836 * mask from before the sigsuspend is what we want 2837 * restored after the signal processing is completed. 2838 */ 2839 if (td->td_pflags & TDP_OLDMASK) { 2840 returnmask = td->td_oldsigmask; 2841 td->td_pflags &= ~TDP_OLDMASK; 2842 } else 2843 returnmask = td->td_sigmask; 2844 2845 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2846 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2847 SIGADDSET(mask, sig); 2848 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2849 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2850 2851 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2852 /* 2853 * See kern_sigaction() for origin of this code. 2854 */ 2855 SIGDELSET(ps->ps_sigcatch, sig); 2856 if (sig != SIGCONT && 2857 sigprop(sig) & SA_IGNORE) 2858 SIGADDSET(ps->ps_sigignore, sig); 2859 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2860 } 2861 td->td_ru.ru_nsignals++; 2862 if (p->p_sig == sig) { 2863 p->p_code = 0; 2864 p->p_sig = 0; 2865 } 2866 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2867 } 2868 return (1); 2869 } 2870 2871 /* 2872 * Kill the current process for stated reason. 2873 */ 2874 void 2875 killproc(p, why) 2876 struct proc *p; 2877 char *why; 2878 { 2879 2880 PROC_LOCK_ASSERT(p, MA_OWNED); 2881 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2882 p->p_comm); 2883 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2884 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2885 p->p_flag |= P_WKILLED; 2886 kern_psignal(p, SIGKILL); 2887 } 2888 2889 /* 2890 * Force the current process to exit with the specified signal, dumping core 2891 * if appropriate. We bypass the normal tests for masked and caught signals, 2892 * allowing unrecoverable failures to terminate the process without changing 2893 * signal state. Mark the accounting record with the signal termination. 2894 * If dumping core, save the signal number for the debugger. Calls exit and 2895 * does not return. 2896 */ 2897 void 2898 sigexit(td, sig) 2899 struct thread *td; 2900 int sig; 2901 { 2902 struct proc *p = td->td_proc; 2903 2904 PROC_LOCK_ASSERT(p, MA_OWNED); 2905 p->p_acflag |= AXSIG; 2906 /* 2907 * We must be single-threading to generate a core dump. This 2908 * ensures that the registers in the core file are up-to-date. 2909 * Also, the ELF dump handler assumes that the thread list doesn't 2910 * change out from under it. 2911 * 2912 * XXX If another thread attempts to single-thread before us 2913 * (e.g. via fork()), we won't get a dump at all. 2914 */ 2915 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2916 p->p_sig = sig; 2917 /* 2918 * Log signals which would cause core dumps 2919 * (Log as LOG_INFO to appease those who don't want 2920 * these messages.) 2921 * XXX : Todo, as well as euid, write out ruid too 2922 * Note that coredump() drops proc lock. 2923 */ 2924 if (coredump(td) == 0) 2925 sig |= WCOREFLAG; 2926 if (kern_logsigexit) 2927 log(LOG_INFO, 2928 "pid %d (%s), uid %d: exited on signal %d%s\n", 2929 p->p_pid, p->p_comm, 2930 td->td_ucred ? td->td_ucred->cr_uid : -1, 2931 sig &~ WCOREFLAG, 2932 sig & WCOREFLAG ? " (core dumped)" : ""); 2933 } else 2934 PROC_UNLOCK(p); 2935 exit1(td, W_EXITCODE(0, sig)); 2936 /* NOTREACHED */ 2937 } 2938 2939 /* 2940 * Send queued SIGCHLD to parent when child process's state 2941 * is changed. 2942 */ 2943 static void 2944 sigparent(struct proc *p, int reason, int status) 2945 { 2946 PROC_LOCK_ASSERT(p, MA_OWNED); 2947 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2948 2949 if (p->p_ksi != NULL) { 2950 p->p_ksi->ksi_signo = SIGCHLD; 2951 p->p_ksi->ksi_code = reason; 2952 p->p_ksi->ksi_status = status; 2953 p->p_ksi->ksi_pid = p->p_pid; 2954 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2955 if (KSI_ONQ(p->p_ksi)) 2956 return; 2957 } 2958 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2959 } 2960 2961 static void 2962 childproc_jobstate(struct proc *p, int reason, int status) 2963 { 2964 struct sigacts *ps; 2965 2966 PROC_LOCK_ASSERT(p, MA_OWNED); 2967 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2968 2969 /* 2970 * Wake up parent sleeping in kern_wait(), also send 2971 * SIGCHLD to parent, but SIGCHLD does not guarantee 2972 * that parent will awake, because parent may masked 2973 * the signal. 2974 */ 2975 p->p_pptr->p_flag |= P_STATCHILD; 2976 wakeup(p->p_pptr); 2977 2978 ps = p->p_pptr->p_sigacts; 2979 mtx_lock(&ps->ps_mtx); 2980 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2981 mtx_unlock(&ps->ps_mtx); 2982 sigparent(p, reason, status); 2983 } else 2984 mtx_unlock(&ps->ps_mtx); 2985 } 2986 2987 void 2988 childproc_stopped(struct proc *p, int reason) 2989 { 2990 childproc_jobstate(p, reason, p->p_xstat); 2991 } 2992 2993 void 2994 childproc_continued(struct proc *p) 2995 { 2996 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2997 } 2998 2999 void 3000 childproc_exited(struct proc *p) 3001 { 3002 int reason; 3003 int status = p->p_xstat; /* convert to int */ 3004 3005 reason = CLD_EXITED; 3006 if (WCOREDUMP(status)) 3007 reason = CLD_DUMPED; 3008 else if (WIFSIGNALED(status)) 3009 reason = CLD_KILLED; 3010 /* 3011 * XXX avoid calling wakeup(p->p_pptr), the work is 3012 * done in exit1(). 3013 */ 3014 sigparent(p, reason, status); 3015 } 3016 3017 /* 3018 * We only have 1 character for the core count in the format 3019 * string, so the range will be 0-9 3020 */ 3021 #define MAX_NUM_CORES 10 3022 static int num_cores = 5; 3023 3024 static int 3025 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3026 { 3027 int error; 3028 int new_val; 3029 3030 new_val = num_cores; 3031 error = sysctl_handle_int(oidp, &new_val, 0, req); 3032 if (error != 0 || req->newptr == NULL) 3033 return (error); 3034 if (new_val > MAX_NUM_CORES) 3035 new_val = MAX_NUM_CORES; 3036 if (new_val < 0) 3037 new_val = 0; 3038 num_cores = new_val; 3039 return (0); 3040 } 3041 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3042 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3043 3044 #if defined(COMPRESS_USER_CORES) 3045 int compress_user_cores = 1; 3046 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3047 &compress_user_cores, 0, "Compression of user corefiles"); 3048 3049 int compress_user_cores_gzlevel = -1; /* default level */ 3050 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3051 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3052 3053 #define GZ_SUFFIX ".gz" 3054 #define GZ_SUFFIX_LEN 3 3055 #endif 3056 3057 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3058 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3059 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3060 sizeof(corefilename), "Process corefile name format string"); 3061 3062 /* 3063 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3064 * Expand the name described in corefilename, using name, uid, and pid 3065 * and open/create core file. 3066 * corefilename is a printf-like string, with three format specifiers: 3067 * %N name of process ("name") 3068 * %P process id (pid) 3069 * %U user id (uid) 3070 * For example, "%N.core" is the default; they can be disabled completely 3071 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3072 * This is controlled by the sysctl variable kern.corefile (see above). 3073 */ 3074 static int 3075 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3076 int compress, struct vnode **vpp, char **namep) 3077 { 3078 struct nameidata nd; 3079 struct sbuf sb; 3080 const char *format; 3081 char *hostname, *name; 3082 int indexpos, i, error, cmode, flags, oflags; 3083 3084 hostname = NULL; 3085 format = corefilename; 3086 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3087 indexpos = -1; 3088 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3089 for (i = 0; format[i] != '\0'; i++) { 3090 switch (format[i]) { 3091 case '%': /* Format character */ 3092 i++; 3093 switch (format[i]) { 3094 case '%': 3095 sbuf_putc(&sb, '%'); 3096 break; 3097 case 'H': /* hostname */ 3098 if (hostname == NULL) { 3099 hostname = malloc(MAXHOSTNAMELEN, 3100 M_TEMP, M_WAITOK); 3101 } 3102 getcredhostname(td->td_ucred, hostname, 3103 MAXHOSTNAMELEN); 3104 sbuf_printf(&sb, "%s", hostname); 3105 break; 3106 case 'I': /* autoincrementing index */ 3107 sbuf_printf(&sb, ""); 3108 indexpos = sbuf_len(&sb) - 1; 3109 break; 3110 case 'N': /* process name */ 3111 sbuf_printf(&sb, "%s", comm); 3112 break; 3113 case 'P': /* process id */ 3114 sbuf_printf(&sb, "%u", pid); 3115 break; 3116 case 'U': /* user id */ 3117 sbuf_printf(&sb, "%u", uid); 3118 break; 3119 default: 3120 log(LOG_ERR, 3121 "Unknown format character %c in " 3122 "corename `%s'\n", format[i], format); 3123 break; 3124 } 3125 break; 3126 default: 3127 sbuf_putc(&sb, format[i]); 3128 break; 3129 } 3130 } 3131 free(hostname, M_TEMP); 3132 #ifdef COMPRESS_USER_CORES 3133 if (compress) 3134 sbuf_printf(&sb, GZ_SUFFIX); 3135 #endif 3136 if (sbuf_error(&sb) != 0) { 3137 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3138 "long\n", (long)pid, comm, (u_long)uid); 3139 sbuf_delete(&sb); 3140 free(name, M_TEMP); 3141 return (ENOMEM); 3142 } 3143 sbuf_finish(&sb); 3144 sbuf_delete(&sb); 3145 3146 cmode = S_IRUSR | S_IWUSR; 3147 oflags = VN_OPEN_NOAUDIT | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3148 3149 /* 3150 * If the core format has a %I in it, then we need to check 3151 * for existing corefiles before returning a name. 3152 * To do this we iterate over 0..num_cores to find a 3153 * non-existing core file name to use. 3154 */ 3155 if (indexpos != -1) { 3156 for (i = 0; i < num_cores; i++) { 3157 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3158 name[indexpos] = '' + i; 3159 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3160 error = vn_open_cred(&nd, &flags, cmode, oflags, 3161 td->td_ucred, NULL); 3162 if (error) { 3163 if (error == EEXIST) 3164 continue; 3165 log(LOG_ERR, 3166 "pid %d (%s), uid (%u): Path `%s' failed " 3167 "on initial open test, error = %d\n", 3168 pid, comm, uid, name, error); 3169 } 3170 goto out; 3171 } 3172 } 3173 3174 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3175 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3176 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3177 out: 3178 if (error) { 3179 #ifdef AUDIT 3180 audit_proc_coredump(td, name, error); 3181 #endif 3182 free(name, M_TEMP); 3183 return (error); 3184 } 3185 NDFREE(&nd, NDF_ONLY_PNBUF); 3186 *vpp = nd.ni_vp; 3187 *namep = name; 3188 return (0); 3189 } 3190 3191 /* 3192 * Dump a process' core. The main routine does some 3193 * policy checking, and creates the name of the coredump; 3194 * then it passes on a vnode and a size limit to the process-specific 3195 * coredump routine if there is one; if there _is not_ one, it returns 3196 * ENOSYS; otherwise it returns the error from the process-specific routine. 3197 */ 3198 3199 static int 3200 coredump(struct thread *td) 3201 { 3202 struct proc *p = td->td_proc; 3203 struct ucred *cred = td->td_ucred; 3204 struct vnode *vp; 3205 struct flock lf; 3206 struct vattr vattr; 3207 int error, error1, locked; 3208 struct mount *mp; 3209 char *name; /* name of corefile */ 3210 off_t limit; 3211 int compress; 3212 3213 #ifdef COMPRESS_USER_CORES 3214 compress = compress_user_cores; 3215 #else 3216 compress = 0; 3217 #endif 3218 PROC_LOCK_ASSERT(p, MA_OWNED); 3219 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3220 _STOPEVENT(p, S_CORE, 0); 3221 3222 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) { 3223 PROC_UNLOCK(p); 3224 return (EFAULT); 3225 } 3226 3227 /* 3228 * Note that the bulk of limit checking is done after 3229 * the corefile is created. The exception is if the limit 3230 * for corefiles is 0, in which case we don't bother 3231 * creating the corefile at all. This layout means that 3232 * a corefile is truncated instead of not being created, 3233 * if it is larger than the limit. 3234 */ 3235 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3236 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3237 PROC_UNLOCK(p); 3238 return (EFBIG); 3239 } 3240 PROC_UNLOCK(p); 3241 3242 restart: 3243 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3244 &vp, &name); 3245 if (error != 0) 3246 return (error); 3247 3248 /* Don't dump to non-regular files or files with links. */ 3249 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3250 vattr.va_nlink != 1) { 3251 VOP_UNLOCK(vp, 0); 3252 error = EFAULT; 3253 goto close; 3254 } 3255 3256 VOP_UNLOCK(vp, 0); 3257 lf.l_whence = SEEK_SET; 3258 lf.l_start = 0; 3259 lf.l_len = 0; 3260 lf.l_type = F_WRLCK; 3261 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3262 3263 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3264 lf.l_type = F_UNLCK; 3265 if (locked) 3266 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3267 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3268 goto out; 3269 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3270 goto out; 3271 free(name, M_TEMP); 3272 goto restart; 3273 } 3274 3275 VATTR_NULL(&vattr); 3276 vattr.va_size = 0; 3277 if (set_core_nodump_flag) 3278 vattr.va_flags = UF_NODUMP; 3279 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3280 VOP_SETATTR(vp, &vattr, cred); 3281 VOP_UNLOCK(vp, 0); 3282 vn_finished_write(mp); 3283 PROC_LOCK(p); 3284 p->p_acflag |= ACORE; 3285 PROC_UNLOCK(p); 3286 3287 if (p->p_sysent->sv_coredump != NULL) { 3288 error = p->p_sysent->sv_coredump(td, vp, limit, 3289 compress ? IMGACT_CORE_COMPRESS : 0); 3290 } else { 3291 error = ENOSYS; 3292 } 3293 3294 if (locked) { 3295 lf.l_type = F_UNLCK; 3296 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3297 } 3298 close: 3299 error1 = vn_close(vp, FWRITE, cred, td); 3300 if (error == 0) 3301 error = error1; 3302 out: 3303 #ifdef AUDIT 3304 audit_proc_coredump(td, name, error); 3305 #endif 3306 free(name, M_TEMP); 3307 return (error); 3308 } 3309 3310 /* 3311 * Nonexistent system call-- signal process (may want to handle it). Flag 3312 * error in case process won't see signal immediately (blocked or ignored). 3313 */ 3314 #ifndef _SYS_SYSPROTO_H_ 3315 struct nosys_args { 3316 int dummy; 3317 }; 3318 #endif 3319 /* ARGSUSED */ 3320 int 3321 nosys(td, args) 3322 struct thread *td; 3323 struct nosys_args *args; 3324 { 3325 struct proc *p = td->td_proc; 3326 3327 PROC_LOCK(p); 3328 tdsignal(td, SIGSYS); 3329 PROC_UNLOCK(p); 3330 return (ENOSYS); 3331 } 3332 3333 /* 3334 * Send a SIGIO or SIGURG signal to a process or process group using stored 3335 * credentials rather than those of the current process. 3336 */ 3337 void 3338 pgsigio(sigiop, sig, checkctty) 3339 struct sigio **sigiop; 3340 int sig, checkctty; 3341 { 3342 ksiginfo_t ksi; 3343 struct sigio *sigio; 3344 3345 ksiginfo_init(&ksi); 3346 ksi.ksi_signo = sig; 3347 ksi.ksi_code = SI_KERNEL; 3348 3349 SIGIO_LOCK(); 3350 sigio = *sigiop; 3351 if (sigio == NULL) { 3352 SIGIO_UNLOCK(); 3353 return; 3354 } 3355 if (sigio->sio_pgid > 0) { 3356 PROC_LOCK(sigio->sio_proc); 3357 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3358 kern_psignal(sigio->sio_proc, sig); 3359 PROC_UNLOCK(sigio->sio_proc); 3360 } else if (sigio->sio_pgid < 0) { 3361 struct proc *p; 3362 3363 PGRP_LOCK(sigio->sio_pgrp); 3364 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3365 PROC_LOCK(p); 3366 if (p->p_state == PRS_NORMAL && 3367 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3368 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3369 kern_psignal(p, sig); 3370 PROC_UNLOCK(p); 3371 } 3372 PGRP_UNLOCK(sigio->sio_pgrp); 3373 } 3374 SIGIO_UNLOCK(); 3375 } 3376 3377 static int 3378 filt_sigattach(struct knote *kn) 3379 { 3380 struct proc *p = curproc; 3381 3382 kn->kn_ptr.p_proc = p; 3383 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3384 3385 knlist_add(&p->p_klist, kn, 0); 3386 3387 return (0); 3388 } 3389 3390 static void 3391 filt_sigdetach(struct knote *kn) 3392 { 3393 struct proc *p = kn->kn_ptr.p_proc; 3394 3395 knlist_remove(&p->p_klist, kn, 0); 3396 } 3397 3398 /* 3399 * signal knotes are shared with proc knotes, so we apply a mask to 3400 * the hint in order to differentiate them from process hints. This 3401 * could be avoided by using a signal-specific knote list, but probably 3402 * isn't worth the trouble. 3403 */ 3404 static int 3405 filt_signal(struct knote *kn, long hint) 3406 { 3407 3408 if (hint & NOTE_SIGNAL) { 3409 hint &= ~NOTE_SIGNAL; 3410 3411 if (kn->kn_id == hint) 3412 kn->kn_data++; 3413 } 3414 return (kn->kn_data != 0); 3415 } 3416 3417 struct sigacts * 3418 sigacts_alloc(void) 3419 { 3420 struct sigacts *ps; 3421 3422 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3423 ps->ps_refcnt = 1; 3424 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3425 return (ps); 3426 } 3427 3428 void 3429 sigacts_free(struct sigacts *ps) 3430 { 3431 3432 mtx_lock(&ps->ps_mtx); 3433 ps->ps_refcnt--; 3434 if (ps->ps_refcnt == 0) { 3435 mtx_destroy(&ps->ps_mtx); 3436 free(ps, M_SUBPROC); 3437 } else 3438 mtx_unlock(&ps->ps_mtx); 3439 } 3440 3441 struct sigacts * 3442 sigacts_hold(struct sigacts *ps) 3443 { 3444 mtx_lock(&ps->ps_mtx); 3445 ps->ps_refcnt++; 3446 mtx_unlock(&ps->ps_mtx); 3447 return (ps); 3448 } 3449 3450 void 3451 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3452 { 3453 3454 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3455 mtx_lock(&src->ps_mtx); 3456 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3457 mtx_unlock(&src->ps_mtx); 3458 } 3459 3460 int 3461 sigacts_shared(struct sigacts *ps) 3462 { 3463 int shared; 3464 3465 mtx_lock(&ps->ps_mtx); 3466 shared = ps->ps_refcnt > 1; 3467 mtx_unlock(&ps->ps_mtx); 3468 return (shared); 3469 }
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