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/8.0/sys/kern/kern_sig.c 197742 2009-10-04 12:11:44Z kib $"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/signalvar.h> 47 #include <sys/vnode.h> 48 #include <sys/acct.h> 49 #include <sys/condvar.h> 50 #include <sys/event.h> 51 #include <sys/fcntl.h> 52 #include <sys/kernel.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/posix4.h> 61 #include <sys/pioctl.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sdt.h> 64 #include <sys/sbuf.h> 65 #include <sys/sleepqueue.h> 66 #include <sys/smp.h> 67 #include <sys/stat.h> 68 #include <sys/sx.h> 69 #include <sys/syscallsubr.h> 70 #include <sys/sysctl.h> 71 #include <sys/sysent.h> 72 #include <sys/syslog.h> 73 #include <sys/sysproto.h> 74 #include <sys/timers.h> 75 #include <sys/unistd.h> 76 #include <sys/wait.h> 77 #include <vm/vm.h> 78 #include <vm/vm_extern.h> 79 #include <vm/uma.h> 80 81 #include <machine/cpu.h> 82 83 #include <security/audit/audit.h> 84 85 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 86 87 SDT_PROVIDER_DECLARE(proc); 88 SDT_PROBE_DEFINE(proc, kernel, , signal_send); 89 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 90 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 91 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 92 SDT_PROBE_DEFINE(proc, kernel, , signal_clear); 93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 95 SDT_PROBE_DEFINE(proc, kernel, , signal_discard); 96 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 99 100 static int coredump(struct thread *); 101 static char *expand_name(const char *, uid_t, pid_t); 102 static int killpg1(struct thread *td, int sig, int pgid, int all); 103 static int issignal(struct thread *td, int stop_allowed); 104 static int sigprop(int sig); 105 static void tdsigwakeup(struct thread *, int, sig_t, int); 106 static void sig_suspend_threads(struct thread *, struct proc *, int); 107 static int filt_sigattach(struct knote *kn); 108 static void filt_sigdetach(struct knote *kn); 109 static int filt_signal(struct knote *kn, long hint); 110 static struct thread *sigtd(struct proc *p, int sig, int prop); 111 static void sigqueue_start(void); 112 113 static uma_zone_t ksiginfo_zone = NULL; 114 struct filterops sig_filtops = 115 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 116 117 int kern_logsigexit = 1; 118 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 119 &kern_logsigexit, 0, 120 "Log processes quitting on abnormal signals to syslog(3)"); 121 122 static int kern_forcesigexit = 1; 123 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 124 &kern_forcesigexit, 0, "Force trap signal to be handled"); 125 126 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 127 128 static int max_pending_per_proc = 128; 129 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 130 &max_pending_per_proc, 0, "Max pending signals per proc"); 131 132 static int preallocate_siginfo = 1024; 133 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 134 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 135 &preallocate_siginfo, 0, "Preallocated signal memory size"); 136 137 static int signal_overflow = 0; 138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 139 &signal_overflow, 0, "Number of signals overflew"); 140 141 static int signal_alloc_fail = 0; 142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 143 &signal_alloc_fail, 0, "signals failed to be allocated"); 144 145 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 146 147 /* 148 * Policy -- Can ucred cr1 send SIGIO to process cr2? 149 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 150 * in the right situations. 151 */ 152 #define CANSIGIO(cr1, cr2) \ 153 ((cr1)->cr_uid == 0 || \ 154 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 155 (cr1)->cr_uid == (cr2)->cr_ruid || \ 156 (cr1)->cr_ruid == (cr2)->cr_uid || \ 157 (cr1)->cr_uid == (cr2)->cr_uid) 158 159 int sugid_coredump; 160 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 161 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 162 163 static int do_coredump = 1; 164 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 165 &do_coredump, 0, "Enable/Disable coredumps"); 166 167 static int set_core_nodump_flag = 0; 168 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 169 0, "Enable setting the NODUMP flag on coredump files"); 170 171 /* 172 * Signal properties and actions. 173 * The array below categorizes the signals and their default actions 174 * according to the following properties: 175 */ 176 #define SA_KILL 0x01 /* terminates process by default */ 177 #define SA_CORE 0x02 /* ditto and coredumps */ 178 #define SA_STOP 0x04 /* suspend process */ 179 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 180 #define SA_IGNORE 0x10 /* ignore by default */ 181 #define SA_CONT 0x20 /* continue if suspended */ 182 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 183 #define SA_PROC 0x80 /* deliverable to any thread */ 184 185 static int sigproptbl[NSIG] = { 186 SA_KILL|SA_PROC, /* SIGHUP */ 187 SA_KILL|SA_PROC, /* SIGINT */ 188 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 189 SA_KILL|SA_CORE, /* SIGILL */ 190 SA_KILL|SA_CORE, /* SIGTRAP */ 191 SA_KILL|SA_CORE, /* SIGABRT */ 192 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 193 SA_KILL|SA_CORE, /* SIGFPE */ 194 SA_KILL|SA_PROC, /* SIGKILL */ 195 SA_KILL|SA_CORE, /* SIGBUS */ 196 SA_KILL|SA_CORE, /* SIGSEGV */ 197 SA_KILL|SA_CORE, /* SIGSYS */ 198 SA_KILL|SA_PROC, /* SIGPIPE */ 199 SA_KILL|SA_PROC, /* SIGALRM */ 200 SA_KILL|SA_PROC, /* SIGTERM */ 201 SA_IGNORE|SA_PROC, /* SIGURG */ 202 SA_STOP|SA_PROC, /* SIGSTOP */ 203 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 204 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 205 SA_IGNORE|SA_PROC, /* SIGCHLD */ 206 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 207 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 208 SA_IGNORE|SA_PROC, /* SIGIO */ 209 SA_KILL, /* SIGXCPU */ 210 SA_KILL, /* SIGXFSZ */ 211 SA_KILL|SA_PROC, /* SIGVTALRM */ 212 SA_KILL|SA_PROC, /* SIGPROF */ 213 SA_IGNORE|SA_PROC, /* SIGWINCH */ 214 SA_IGNORE|SA_PROC, /* SIGINFO */ 215 SA_KILL|SA_PROC, /* SIGUSR1 */ 216 SA_KILL|SA_PROC, /* SIGUSR2 */ 217 }; 218 219 static void 220 sigqueue_start(void) 221 { 222 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 223 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 224 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 225 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 226 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 227 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 228 } 229 230 ksiginfo_t * 231 ksiginfo_alloc(int wait) 232 { 233 int flags; 234 235 flags = M_ZERO; 236 if (! wait) 237 flags |= M_NOWAIT; 238 if (ksiginfo_zone != NULL) 239 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 240 return (NULL); 241 } 242 243 void 244 ksiginfo_free(ksiginfo_t *ksi) 245 { 246 uma_zfree(ksiginfo_zone, ksi); 247 } 248 249 static __inline int 250 ksiginfo_tryfree(ksiginfo_t *ksi) 251 { 252 if (!(ksi->ksi_flags & KSI_EXT)) { 253 uma_zfree(ksiginfo_zone, ksi); 254 return (1); 255 } 256 return (0); 257 } 258 259 void 260 sigqueue_init(sigqueue_t *list, struct proc *p) 261 { 262 SIGEMPTYSET(list->sq_signals); 263 SIGEMPTYSET(list->sq_kill); 264 TAILQ_INIT(&list->sq_list); 265 list->sq_proc = p; 266 list->sq_flags = SQ_INIT; 267 } 268 269 /* 270 * Get a signal's ksiginfo. 271 * Return: 272 * 0 - signal not found 273 * others - signal number 274 */ 275 int 276 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 277 { 278 struct proc *p = sq->sq_proc; 279 struct ksiginfo *ksi, *next; 280 int count = 0; 281 282 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 283 284 if (!SIGISMEMBER(sq->sq_signals, signo)) 285 return (0); 286 287 if (SIGISMEMBER(sq->sq_kill, signo)) { 288 count++; 289 SIGDELSET(sq->sq_kill, signo); 290 } 291 292 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 293 if (ksi->ksi_signo == signo) { 294 if (count == 0) { 295 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 296 ksi->ksi_sigq = NULL; 297 ksiginfo_copy(ksi, si); 298 if (ksiginfo_tryfree(ksi) && p != NULL) 299 p->p_pendingcnt--; 300 } 301 if (++count > 1) 302 break; 303 } 304 } 305 306 if (count <= 1) 307 SIGDELSET(sq->sq_signals, signo); 308 si->ksi_signo = signo; 309 return (signo); 310 } 311 312 void 313 sigqueue_take(ksiginfo_t *ksi) 314 { 315 struct ksiginfo *kp; 316 struct proc *p; 317 sigqueue_t *sq; 318 319 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 320 return; 321 322 p = sq->sq_proc; 323 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 324 ksi->ksi_sigq = NULL; 325 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 326 p->p_pendingcnt--; 327 328 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 329 kp = TAILQ_NEXT(kp, ksi_link)) { 330 if (kp->ksi_signo == ksi->ksi_signo) 331 break; 332 } 333 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 334 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 335 } 336 337 int 338 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 339 { 340 struct proc *p = sq->sq_proc; 341 struct ksiginfo *ksi; 342 int ret = 0; 343 344 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 345 346 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 347 SIGADDSET(sq->sq_kill, signo); 348 goto out_set_bit; 349 } 350 351 /* directly insert the ksi, don't copy it */ 352 if (si->ksi_flags & KSI_INS) { 353 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 354 si->ksi_sigq = sq; 355 goto out_set_bit; 356 } 357 358 if (__predict_false(ksiginfo_zone == NULL)) { 359 SIGADDSET(sq->sq_kill, signo); 360 goto out_set_bit; 361 } 362 363 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 364 signal_overflow++; 365 ret = EAGAIN; 366 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 367 signal_alloc_fail++; 368 ret = EAGAIN; 369 } else { 370 if (p != NULL) 371 p->p_pendingcnt++; 372 ksiginfo_copy(si, ksi); 373 ksi->ksi_signo = signo; 374 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 375 ksi->ksi_sigq = sq; 376 } 377 378 if ((si->ksi_flags & KSI_TRAP) != 0) { 379 if (ret != 0) 380 SIGADDSET(sq->sq_kill, signo); 381 ret = 0; 382 goto out_set_bit; 383 } 384 385 if (ret != 0) 386 return (ret); 387 388 out_set_bit: 389 SIGADDSET(sq->sq_signals, signo); 390 return (ret); 391 } 392 393 void 394 sigqueue_flush(sigqueue_t *sq) 395 { 396 struct proc *p = sq->sq_proc; 397 ksiginfo_t *ksi; 398 399 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 400 401 if (p != NULL) 402 PROC_LOCK_ASSERT(p, MA_OWNED); 403 404 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 405 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 406 ksi->ksi_sigq = NULL; 407 if (ksiginfo_tryfree(ksi) && p != NULL) 408 p->p_pendingcnt--; 409 } 410 411 SIGEMPTYSET(sq->sq_signals); 412 SIGEMPTYSET(sq->sq_kill); 413 } 414 415 void 416 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 417 { 418 ksiginfo_t *ksi; 419 420 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 421 422 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 423 SIGADDSET(*set, ksi->ksi_signo); 424 SIGSETOR(*set, sq->sq_kill); 425 } 426 427 void 428 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 429 { 430 sigset_t tmp, set; 431 struct proc *p1, *p2; 432 ksiginfo_t *ksi, *next; 433 434 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 435 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 436 /* 437 * make a copy, this allows setp to point to src or dst 438 * sq_signals without trouble. 439 */ 440 set = *setp; 441 p1 = src->sq_proc; 442 p2 = dst->sq_proc; 443 /* Move siginfo to target list */ 444 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 445 if (SIGISMEMBER(set, ksi->ksi_signo)) { 446 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 447 if (p1 != NULL) 448 p1->p_pendingcnt--; 449 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = dst; 451 if (p2 != NULL) 452 p2->p_pendingcnt++; 453 } 454 } 455 456 /* Move pending bits to target list */ 457 tmp = src->sq_kill; 458 SIGSETAND(tmp, set); 459 SIGSETOR(dst->sq_kill, tmp); 460 SIGSETNAND(src->sq_kill, tmp); 461 462 tmp = src->sq_signals; 463 SIGSETAND(tmp, set); 464 SIGSETOR(dst->sq_signals, tmp); 465 SIGSETNAND(src->sq_signals, tmp); 466 467 /* Finally, rescan src queue and set pending bits for it */ 468 sigqueue_collect_set(src, &src->sq_signals); 469 } 470 471 void 472 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 473 { 474 sigset_t set; 475 476 SIGEMPTYSET(set); 477 SIGADDSET(set, signo); 478 sigqueue_move_set(src, dst, &set); 479 } 480 481 void 482 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 483 { 484 struct proc *p = sq->sq_proc; 485 ksiginfo_t *ksi, *next; 486 487 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 488 489 /* Remove siginfo queue */ 490 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 491 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 492 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 493 ksi->ksi_sigq = NULL; 494 if (ksiginfo_tryfree(ksi) && p != NULL) 495 p->p_pendingcnt--; 496 } 497 } 498 SIGSETNAND(sq->sq_kill, *set); 499 SIGSETNAND(sq->sq_signals, *set); 500 /* Finally, rescan queue and set pending bits for it */ 501 sigqueue_collect_set(sq, &sq->sq_signals); 502 } 503 504 void 505 sigqueue_delete(sigqueue_t *sq, int signo) 506 { 507 sigset_t set; 508 509 SIGEMPTYSET(set); 510 SIGADDSET(set, signo); 511 sigqueue_delete_set(sq, &set); 512 } 513 514 /* Remove a set of signals for a process */ 515 void 516 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 517 { 518 sigqueue_t worklist; 519 struct thread *td0; 520 521 PROC_LOCK_ASSERT(p, MA_OWNED); 522 523 sigqueue_init(&worklist, NULL); 524 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 525 526 FOREACH_THREAD_IN_PROC(p, td0) 527 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 528 529 sigqueue_flush(&worklist); 530 } 531 532 void 533 sigqueue_delete_proc(struct proc *p, int signo) 534 { 535 sigset_t set; 536 537 SIGEMPTYSET(set); 538 SIGADDSET(set, signo); 539 sigqueue_delete_set_proc(p, &set); 540 } 541 542 void 543 sigqueue_delete_stopmask_proc(struct proc *p) 544 { 545 sigset_t set; 546 547 SIGEMPTYSET(set); 548 SIGADDSET(set, SIGSTOP); 549 SIGADDSET(set, SIGTSTP); 550 SIGADDSET(set, SIGTTIN); 551 SIGADDSET(set, SIGTTOU); 552 sigqueue_delete_set_proc(p, &set); 553 } 554 555 /* 556 * Determine signal that should be delivered to process p, the current 557 * process, 0 if none. If there is a pending stop signal with default 558 * action, the process stops in issignal(). 559 */ 560 int 561 cursig(struct thread *td, int stop_allowed) 562 { 563 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 564 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 565 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 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, stop_allowed) : 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 sigset_t set; 581 582 p = td->td_proc; 583 584 PROC_LOCK_ASSERT(p, MA_OWNED); 585 586 /* 587 * If our mask changed we may have to move signal that were 588 * previously masked by all threads to our sigqueue. 589 */ 590 set = p->p_sigqueue.sq_signals; 591 SIGSETNAND(set, td->td_sigmask); 592 if (! SIGISEMPTY(set)) 593 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set); 594 if (SIGPENDING(td)) { 595 thread_lock(td); 596 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 597 thread_unlock(td); 598 } 599 } 600 601 int 602 sigonstack(size_t sp) 603 { 604 struct thread *td = curthread; 605 606 return ((td->td_pflags & TDP_ALTSTACK) ? 607 #if defined(COMPAT_43) 608 ((td->td_sigstk.ss_size == 0) ? 609 (td->td_sigstk.ss_flags & SS_ONSTACK) : 610 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 611 #else 612 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 613 #endif 614 : 0); 615 } 616 617 static __inline int 618 sigprop(int sig) 619 { 620 621 if (sig > 0 && sig < NSIG) 622 return (sigproptbl[_SIG_IDX(sig)]); 623 return (0); 624 } 625 626 int 627 sig_ffs(sigset_t *set) 628 { 629 int i; 630 631 for (i = 0; i < _SIG_WORDS; i++) 632 if (set->__bits[i]) 633 return (ffs(set->__bits[i]) + (i * 32)); 634 return (0); 635 } 636 637 /* 638 * kern_sigaction 639 * sigaction 640 * freebsd4_sigaction 641 * osigaction 642 */ 643 int 644 kern_sigaction(td, sig, act, oact, flags) 645 struct thread *td; 646 register int sig; 647 struct sigaction *act, *oact; 648 int flags; 649 { 650 struct sigacts *ps; 651 struct proc *p = td->td_proc; 652 653 if (!_SIG_VALID(sig)) 654 return (EINVAL); 655 656 PROC_LOCK(p); 657 ps = p->p_sigacts; 658 mtx_lock(&ps->ps_mtx); 659 if (oact) { 660 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 661 oact->sa_flags = 0; 662 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 663 oact->sa_flags |= SA_ONSTACK; 664 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 665 oact->sa_flags |= SA_RESTART; 666 if (SIGISMEMBER(ps->ps_sigreset, sig)) 667 oact->sa_flags |= SA_RESETHAND; 668 if (SIGISMEMBER(ps->ps_signodefer, sig)) 669 oact->sa_flags |= SA_NODEFER; 670 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 671 oact->sa_flags |= SA_SIGINFO; 672 oact->sa_sigaction = 673 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 674 } else 675 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 676 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 677 oact->sa_flags |= SA_NOCLDSTOP; 678 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 679 oact->sa_flags |= SA_NOCLDWAIT; 680 } 681 if (act) { 682 if ((sig == SIGKILL || sig == SIGSTOP) && 683 act->sa_handler != SIG_DFL) { 684 mtx_unlock(&ps->ps_mtx); 685 PROC_UNLOCK(p); 686 return (EINVAL); 687 } 688 689 /* 690 * Change setting atomically. 691 */ 692 693 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 694 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 695 if (act->sa_flags & SA_SIGINFO) { 696 ps->ps_sigact[_SIG_IDX(sig)] = 697 (__sighandler_t *)act->sa_sigaction; 698 SIGADDSET(ps->ps_siginfo, sig); 699 } else { 700 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 701 SIGDELSET(ps->ps_siginfo, sig); 702 } 703 if (!(act->sa_flags & SA_RESTART)) 704 SIGADDSET(ps->ps_sigintr, sig); 705 else 706 SIGDELSET(ps->ps_sigintr, sig); 707 if (act->sa_flags & SA_ONSTACK) 708 SIGADDSET(ps->ps_sigonstack, sig); 709 else 710 SIGDELSET(ps->ps_sigonstack, sig); 711 if (act->sa_flags & SA_RESETHAND) 712 SIGADDSET(ps->ps_sigreset, sig); 713 else 714 SIGDELSET(ps->ps_sigreset, sig); 715 if (act->sa_flags & SA_NODEFER) 716 SIGADDSET(ps->ps_signodefer, sig); 717 else 718 SIGDELSET(ps->ps_signodefer, sig); 719 if (sig == SIGCHLD) { 720 if (act->sa_flags & SA_NOCLDSTOP) 721 ps->ps_flag |= PS_NOCLDSTOP; 722 else 723 ps->ps_flag &= ~PS_NOCLDSTOP; 724 if (act->sa_flags & SA_NOCLDWAIT) { 725 /* 726 * Paranoia: since SA_NOCLDWAIT is implemented 727 * by reparenting the dying child to PID 1 (and 728 * trust it to reap the zombie), PID 1 itself 729 * is forbidden to set SA_NOCLDWAIT. 730 */ 731 if (p->p_pid == 1) 732 ps->ps_flag &= ~PS_NOCLDWAIT; 733 else 734 ps->ps_flag |= PS_NOCLDWAIT; 735 } else 736 ps->ps_flag &= ~PS_NOCLDWAIT; 737 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 738 ps->ps_flag |= PS_CLDSIGIGN; 739 else 740 ps->ps_flag &= ~PS_CLDSIGIGN; 741 } 742 /* 743 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 744 * and for signals set to SIG_DFL where the default is to 745 * ignore. However, don't put SIGCONT in ps_sigignore, as we 746 * have to restart the process. 747 */ 748 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 749 (sigprop(sig) & SA_IGNORE && 750 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 751 /* never to be seen again */ 752 sigqueue_delete_proc(p, sig); 753 if (sig != SIGCONT) 754 /* easier in psignal */ 755 SIGADDSET(ps->ps_sigignore, sig); 756 SIGDELSET(ps->ps_sigcatch, sig); 757 } else { 758 SIGDELSET(ps->ps_sigignore, sig); 759 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 760 SIGDELSET(ps->ps_sigcatch, sig); 761 else 762 SIGADDSET(ps->ps_sigcatch, sig); 763 } 764 #ifdef COMPAT_FREEBSD4 765 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 766 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 767 (flags & KSA_FREEBSD4) == 0) 768 SIGDELSET(ps->ps_freebsd4, sig); 769 else 770 SIGADDSET(ps->ps_freebsd4, sig); 771 #endif 772 #ifdef COMPAT_43 773 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 774 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 775 (flags & KSA_OSIGSET) == 0) 776 SIGDELSET(ps->ps_osigset, sig); 777 else 778 SIGADDSET(ps->ps_osigset, sig); 779 #endif 780 } 781 mtx_unlock(&ps->ps_mtx); 782 PROC_UNLOCK(p); 783 return (0); 784 } 785 786 #ifndef _SYS_SYSPROTO_H_ 787 struct sigaction_args { 788 int sig; 789 struct sigaction *act; 790 struct sigaction *oact; 791 }; 792 #endif 793 int 794 sigaction(td, uap) 795 struct thread *td; 796 register struct sigaction_args *uap; 797 { 798 struct sigaction act, oact; 799 register struct sigaction *actp, *oactp; 800 int error; 801 802 actp = (uap->act != NULL) ? &act : NULL; 803 oactp = (uap->oact != NULL) ? &oact : NULL; 804 if (actp) { 805 error = copyin(uap->act, actp, sizeof(act)); 806 if (error) 807 return (error); 808 } 809 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 810 if (oactp && !error) 811 error = copyout(oactp, uap->oact, sizeof(oact)); 812 return (error); 813 } 814 815 #ifdef COMPAT_FREEBSD4 816 #ifndef _SYS_SYSPROTO_H_ 817 struct freebsd4_sigaction_args { 818 int sig; 819 struct sigaction *act; 820 struct sigaction *oact; 821 }; 822 #endif 823 int 824 freebsd4_sigaction(td, uap) 825 struct thread *td; 826 register struct freebsd4_sigaction_args *uap; 827 { 828 struct sigaction act, oact; 829 register struct sigaction *actp, *oactp; 830 int error; 831 832 833 actp = (uap->act != NULL) ? &act : NULL; 834 oactp = (uap->oact != NULL) ? &oact : NULL; 835 if (actp) { 836 error = copyin(uap->act, actp, sizeof(act)); 837 if (error) 838 return (error); 839 } 840 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 841 if (oactp && !error) 842 error = copyout(oactp, uap->oact, sizeof(oact)); 843 return (error); 844 } 845 #endif /* COMAPT_FREEBSD4 */ 846 847 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 848 #ifndef _SYS_SYSPROTO_H_ 849 struct osigaction_args { 850 int signum; 851 struct osigaction *nsa; 852 struct osigaction *osa; 853 }; 854 #endif 855 int 856 osigaction(td, uap) 857 struct thread *td; 858 register struct osigaction_args *uap; 859 { 860 struct osigaction sa; 861 struct sigaction nsa, osa; 862 register struct sigaction *nsap, *osap; 863 int error; 864 865 if (uap->signum <= 0 || uap->signum >= ONSIG) 866 return (EINVAL); 867 868 nsap = (uap->nsa != NULL) ? &nsa : NULL; 869 osap = (uap->osa != NULL) ? &osa : NULL; 870 871 if (nsap) { 872 error = copyin(uap->nsa, &sa, sizeof(sa)); 873 if (error) 874 return (error); 875 nsap->sa_handler = sa.sa_handler; 876 nsap->sa_flags = sa.sa_flags; 877 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 878 } 879 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 880 if (osap && !error) { 881 sa.sa_handler = osap->sa_handler; 882 sa.sa_flags = osap->sa_flags; 883 SIG2OSIG(osap->sa_mask, sa.sa_mask); 884 error = copyout(&sa, uap->osa, sizeof(sa)); 885 } 886 return (error); 887 } 888 889 #if !defined(__i386__) 890 /* Avoid replicating the same stub everywhere */ 891 int 892 osigreturn(td, uap) 893 struct thread *td; 894 struct osigreturn_args *uap; 895 { 896 897 return (nosys(td, (struct nosys_args *)uap)); 898 } 899 #endif 900 #endif /* COMPAT_43 */ 901 902 /* 903 * Initialize signal state for process 0; 904 * set to ignore signals that are ignored by default. 905 */ 906 void 907 siginit(p) 908 struct proc *p; 909 { 910 register int i; 911 struct sigacts *ps; 912 913 PROC_LOCK(p); 914 ps = p->p_sigacts; 915 mtx_lock(&ps->ps_mtx); 916 for (i = 1; i <= NSIG; i++) 917 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 918 SIGADDSET(ps->ps_sigignore, i); 919 mtx_unlock(&ps->ps_mtx); 920 PROC_UNLOCK(p); 921 } 922 923 /* 924 * Reset signals for an exec of the specified process. 925 */ 926 void 927 execsigs(struct proc *p) 928 { 929 struct sigacts *ps; 930 int sig; 931 struct thread *td; 932 933 /* 934 * Reset caught signals. Held signals remain held 935 * through td_sigmask (unless they were caught, 936 * and are now ignored by default). 937 */ 938 PROC_LOCK_ASSERT(p, MA_OWNED); 939 td = FIRST_THREAD_IN_PROC(p); 940 ps = p->p_sigacts; 941 mtx_lock(&ps->ps_mtx); 942 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 943 sig = sig_ffs(&ps->ps_sigcatch); 944 SIGDELSET(ps->ps_sigcatch, sig); 945 if (sigprop(sig) & SA_IGNORE) { 946 if (sig != SIGCONT) 947 SIGADDSET(ps->ps_sigignore, sig); 948 sigqueue_delete_proc(p, sig); 949 } 950 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 951 } 952 /* 953 * Reset stack state to the user stack. 954 * Clear set of signals caught on the signal stack. 955 */ 956 td->td_sigstk.ss_flags = SS_DISABLE; 957 td->td_sigstk.ss_size = 0; 958 td->td_sigstk.ss_sp = 0; 959 td->td_pflags &= ~TDP_ALTSTACK; 960 /* 961 * Reset no zombies if child dies flag as Solaris does. 962 */ 963 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 964 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 965 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 966 mtx_unlock(&ps->ps_mtx); 967 } 968 969 /* 970 * kern_sigprocmask() 971 * 972 * Manipulate signal mask. 973 */ 974 int 975 kern_sigprocmask(td, how, set, oset, old) 976 struct thread *td; 977 int how; 978 sigset_t *set, *oset; 979 int old; 980 { 981 int error; 982 983 PROC_LOCK(td->td_proc); 984 if (oset != NULL) 985 *oset = td->td_sigmask; 986 987 error = 0; 988 if (set != NULL) { 989 switch (how) { 990 case SIG_BLOCK: 991 SIG_CANTMASK(*set); 992 SIGSETOR(td->td_sigmask, *set); 993 break; 994 case SIG_UNBLOCK: 995 SIGSETNAND(td->td_sigmask, *set); 996 signotify(td); 997 break; 998 case SIG_SETMASK: 999 SIG_CANTMASK(*set); 1000 if (old) 1001 SIGSETLO(td->td_sigmask, *set); 1002 else 1003 td->td_sigmask = *set; 1004 signotify(td); 1005 break; 1006 default: 1007 error = EINVAL; 1008 break; 1009 } 1010 } 1011 PROC_UNLOCK(td->td_proc); 1012 return (error); 1013 } 1014 1015 #ifndef _SYS_SYSPROTO_H_ 1016 struct sigprocmask_args { 1017 int how; 1018 const sigset_t *set; 1019 sigset_t *oset; 1020 }; 1021 #endif 1022 int 1023 sigprocmask(td, uap) 1024 register struct thread *td; 1025 struct sigprocmask_args *uap; 1026 { 1027 sigset_t set, oset; 1028 sigset_t *setp, *osetp; 1029 int error; 1030 1031 setp = (uap->set != NULL) ? &set : NULL; 1032 osetp = (uap->oset != NULL) ? &oset : NULL; 1033 if (setp) { 1034 error = copyin(uap->set, setp, sizeof(set)); 1035 if (error) 1036 return (error); 1037 } 1038 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1039 if (osetp && !error) { 1040 error = copyout(osetp, uap->oset, sizeof(oset)); 1041 } 1042 return (error); 1043 } 1044 1045 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1046 #ifndef _SYS_SYSPROTO_H_ 1047 struct osigprocmask_args { 1048 int how; 1049 osigset_t mask; 1050 }; 1051 #endif 1052 int 1053 osigprocmask(td, uap) 1054 register struct thread *td; 1055 struct osigprocmask_args *uap; 1056 { 1057 sigset_t set, oset; 1058 int error; 1059 1060 OSIG2SIG(uap->mask, set); 1061 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1062 SIG2OSIG(oset, td->td_retval[0]); 1063 return (error); 1064 } 1065 #endif /* COMPAT_43 */ 1066 1067 int 1068 sigwait(struct thread *td, struct sigwait_args *uap) 1069 { 1070 ksiginfo_t ksi; 1071 sigset_t set; 1072 int error; 1073 1074 error = copyin(uap->set, &set, sizeof(set)); 1075 if (error) { 1076 td->td_retval[0] = error; 1077 return (0); 1078 } 1079 1080 error = kern_sigtimedwait(td, set, &ksi, NULL); 1081 if (error) { 1082 if (error == ERESTART) 1083 return (error); 1084 td->td_retval[0] = error; 1085 return (0); 1086 } 1087 1088 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1089 td->td_retval[0] = error; 1090 return (0); 1091 } 1092 1093 int 1094 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1095 { 1096 struct timespec ts; 1097 struct timespec *timeout; 1098 sigset_t set; 1099 ksiginfo_t ksi; 1100 int error; 1101 1102 if (uap->timeout) { 1103 error = copyin(uap->timeout, &ts, sizeof(ts)); 1104 if (error) 1105 return (error); 1106 1107 timeout = &ts; 1108 } else 1109 timeout = NULL; 1110 1111 error = copyin(uap->set, &set, sizeof(set)); 1112 if (error) 1113 return (error); 1114 1115 error = kern_sigtimedwait(td, set, &ksi, timeout); 1116 if (error) 1117 return (error); 1118 1119 if (uap->info) 1120 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1121 1122 if (error == 0) 1123 td->td_retval[0] = ksi.ksi_signo; 1124 return (error); 1125 } 1126 1127 int 1128 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1129 { 1130 ksiginfo_t ksi; 1131 sigset_t set; 1132 int error; 1133 1134 error = copyin(uap->set, &set, sizeof(set)); 1135 if (error) 1136 return (error); 1137 1138 error = kern_sigtimedwait(td, set, &ksi, NULL); 1139 if (error) 1140 return (error); 1141 1142 if (uap->info) 1143 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1144 1145 if (error == 0) 1146 td->td_retval[0] = ksi.ksi_signo; 1147 return (error); 1148 } 1149 1150 int 1151 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1152 struct timespec *timeout) 1153 { 1154 struct sigacts *ps; 1155 sigset_t savedmask; 1156 struct proc *p; 1157 int error, sig, hz, i, timevalid = 0; 1158 struct timespec rts, ets, ts; 1159 struct timeval tv; 1160 1161 p = td->td_proc; 1162 error = 0; 1163 sig = 0; 1164 ets.tv_sec = 0; 1165 ets.tv_nsec = 0; 1166 SIG_CANTMASK(waitset); 1167 1168 PROC_LOCK(p); 1169 ps = p->p_sigacts; 1170 savedmask = td->td_sigmask; 1171 if (timeout) { 1172 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1173 timevalid = 1; 1174 getnanouptime(&rts); 1175 ets = rts; 1176 timespecadd(&ets, timeout); 1177 } 1178 } 1179 1180 restart: 1181 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1182 if (!SIGISMEMBER(waitset, i)) 1183 continue; 1184 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1185 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1186 sigqueue_move(&p->p_sigqueue, 1187 &td->td_sigqueue, i); 1188 } else 1189 continue; 1190 } 1191 1192 SIGFILLSET(td->td_sigmask); 1193 SIG_CANTMASK(td->td_sigmask); 1194 SIGDELSET(td->td_sigmask, i); 1195 mtx_lock(&ps->ps_mtx); 1196 sig = cursig(td, SIG_STOP_ALLOWED); 1197 mtx_unlock(&ps->ps_mtx); 1198 if (sig) 1199 goto out; 1200 else { 1201 /* 1202 * Because cursig() may have stopped current thread, 1203 * after it is resumed, things may have already been 1204 * changed, it should rescan any pending signals. 1205 */ 1206 goto restart; 1207 } 1208 } 1209 1210 if (error) 1211 goto out; 1212 1213 /* 1214 * POSIX says this must be checked after looking for pending 1215 * signals. 1216 */ 1217 if (timeout) { 1218 if (!timevalid) { 1219 error = EINVAL; 1220 goto out; 1221 } 1222 getnanouptime(&rts); 1223 if (timespeccmp(&rts, &ets, >=)) { 1224 error = EAGAIN; 1225 goto out; 1226 } 1227 ts = ets; 1228 timespecsub(&ts, &rts); 1229 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1230 hz = tvtohz(&tv); 1231 } else 1232 hz = 0; 1233 1234 td->td_sigmask = savedmask; 1235 SIGSETNAND(td->td_sigmask, waitset); 1236 signotify(td); 1237 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1238 if (timeout) { 1239 if (error == ERESTART) { 1240 /* timeout can not be restarted. */ 1241 error = EINTR; 1242 } else if (error == EAGAIN) { 1243 /* will calculate timeout by ourself. */ 1244 error = 0; 1245 } 1246 } 1247 goto restart; 1248 1249 out: 1250 td->td_sigmask = savedmask; 1251 signotify(td); 1252 if (sig) { 1253 ksiginfo_init(ksi); 1254 sigqueue_get(&td->td_sigqueue, sig, ksi); 1255 ksi->ksi_signo = sig; 1256 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 error = 0; 1262 1263 #ifdef KTRACE 1264 if (KTRPOINT(td, KTR_PSIG)) { 1265 sig_t action; 1266 1267 mtx_lock(&ps->ps_mtx); 1268 action = ps->ps_sigact[_SIG_IDX(sig)]; 1269 mtx_unlock(&ps->ps_mtx); 1270 ktrpsig(sig, action, &td->td_sigmask, 0); 1271 } 1272 #endif 1273 if (sig == SIGKILL) 1274 sigexit(td, sig); 1275 } 1276 PROC_UNLOCK(p); 1277 return (error); 1278 } 1279 1280 #ifndef _SYS_SYSPROTO_H_ 1281 struct sigpending_args { 1282 sigset_t *set; 1283 }; 1284 #endif 1285 int 1286 sigpending(td, uap) 1287 struct thread *td; 1288 struct sigpending_args *uap; 1289 { 1290 struct proc *p = td->td_proc; 1291 sigset_t pending; 1292 1293 PROC_LOCK(p); 1294 pending = p->p_sigqueue.sq_signals; 1295 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1296 PROC_UNLOCK(p); 1297 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1298 } 1299 1300 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1301 #ifndef _SYS_SYSPROTO_H_ 1302 struct osigpending_args { 1303 int dummy; 1304 }; 1305 #endif 1306 int 1307 osigpending(td, uap) 1308 struct thread *td; 1309 struct osigpending_args *uap; 1310 { 1311 struct proc *p = td->td_proc; 1312 sigset_t pending; 1313 1314 PROC_LOCK(p); 1315 pending = p->p_sigqueue.sq_signals; 1316 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1317 PROC_UNLOCK(p); 1318 SIG2OSIG(pending, td->td_retval[0]); 1319 return (0); 1320 } 1321 #endif /* COMPAT_43 */ 1322 1323 #if defined(COMPAT_43) 1324 /* 1325 * Generalized interface signal handler, 4.3-compatible. 1326 */ 1327 #ifndef _SYS_SYSPROTO_H_ 1328 struct osigvec_args { 1329 int signum; 1330 struct sigvec *nsv; 1331 struct sigvec *osv; 1332 }; 1333 #endif 1334 /* ARGSUSED */ 1335 int 1336 osigvec(td, uap) 1337 struct thread *td; 1338 register struct osigvec_args *uap; 1339 { 1340 struct sigvec vec; 1341 struct sigaction nsa, osa; 1342 register struct sigaction *nsap, *osap; 1343 int error; 1344 1345 if (uap->signum <= 0 || uap->signum >= ONSIG) 1346 return (EINVAL); 1347 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1348 osap = (uap->osv != NULL) ? &osa : NULL; 1349 if (nsap) { 1350 error = copyin(uap->nsv, &vec, sizeof(vec)); 1351 if (error) 1352 return (error); 1353 nsap->sa_handler = vec.sv_handler; 1354 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1355 nsap->sa_flags = vec.sv_flags; 1356 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1357 } 1358 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1359 if (osap && !error) { 1360 vec.sv_handler = osap->sa_handler; 1361 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1362 vec.sv_flags = osap->sa_flags; 1363 vec.sv_flags &= ~SA_NOCLDWAIT; 1364 vec.sv_flags ^= SA_RESTART; 1365 error = copyout(&vec, uap->osv, sizeof(vec)); 1366 } 1367 return (error); 1368 } 1369 1370 #ifndef _SYS_SYSPROTO_H_ 1371 struct osigblock_args { 1372 int mask; 1373 }; 1374 #endif 1375 int 1376 osigblock(td, uap) 1377 register struct thread *td; 1378 struct osigblock_args *uap; 1379 { 1380 struct proc *p = td->td_proc; 1381 sigset_t set; 1382 1383 OSIG2SIG(uap->mask, set); 1384 SIG_CANTMASK(set); 1385 PROC_LOCK(p); 1386 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1387 SIGSETOR(td->td_sigmask, set); 1388 PROC_UNLOCK(p); 1389 return (0); 1390 } 1391 1392 #ifndef _SYS_SYSPROTO_H_ 1393 struct osigsetmask_args { 1394 int mask; 1395 }; 1396 #endif 1397 int 1398 osigsetmask(td, uap) 1399 struct thread *td; 1400 struct osigsetmask_args *uap; 1401 { 1402 struct proc *p = td->td_proc; 1403 sigset_t set; 1404 1405 OSIG2SIG(uap->mask, set); 1406 SIG_CANTMASK(set); 1407 PROC_LOCK(p); 1408 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1409 SIGSETLO(td->td_sigmask, set); 1410 signotify(td); 1411 PROC_UNLOCK(p); 1412 return (0); 1413 } 1414 #endif /* COMPAT_43 */ 1415 1416 /* 1417 * Suspend calling thread until signal, providing mask to be set in the 1418 * meantime. 1419 */ 1420 #ifndef _SYS_SYSPROTO_H_ 1421 struct sigsuspend_args { 1422 const sigset_t *sigmask; 1423 }; 1424 #endif 1425 /* ARGSUSED */ 1426 int 1427 sigsuspend(td, uap) 1428 struct thread *td; 1429 struct sigsuspend_args *uap; 1430 { 1431 sigset_t mask; 1432 int error; 1433 1434 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1435 if (error) 1436 return (error); 1437 return (kern_sigsuspend(td, mask)); 1438 } 1439 1440 int 1441 kern_sigsuspend(struct thread *td, sigset_t mask) 1442 { 1443 struct proc *p = td->td_proc; 1444 1445 /* 1446 * When returning from sigsuspend, we want 1447 * the old mask to be restored after the 1448 * signal handler has finished. Thus, we 1449 * save it here and mark the sigacts structure 1450 * to indicate this. 1451 */ 1452 PROC_LOCK(p); 1453 td->td_oldsigmask = td->td_sigmask; 1454 td->td_pflags |= TDP_OLDMASK; 1455 SIG_CANTMASK(mask); 1456 td->td_sigmask = mask; 1457 signotify(td); 1458 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1459 /* void */; 1460 PROC_UNLOCK(p); 1461 /* always return EINTR rather than ERESTART... */ 1462 return (EINTR); 1463 } 1464 1465 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1466 /* 1467 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1468 * convention: libc stub passes mask, not pointer, to save a copyin. 1469 */ 1470 #ifndef _SYS_SYSPROTO_H_ 1471 struct osigsuspend_args { 1472 osigset_t mask; 1473 }; 1474 #endif 1475 /* ARGSUSED */ 1476 int 1477 osigsuspend(td, uap) 1478 struct thread *td; 1479 struct osigsuspend_args *uap; 1480 { 1481 struct proc *p = td->td_proc; 1482 sigset_t mask; 1483 1484 PROC_LOCK(p); 1485 td->td_oldsigmask = td->td_sigmask; 1486 td->td_pflags |= TDP_OLDMASK; 1487 OSIG2SIG(uap->mask, mask); 1488 SIG_CANTMASK(mask); 1489 SIGSETLO(td->td_sigmask, mask); 1490 signotify(td); 1491 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1492 /* void */; 1493 PROC_UNLOCK(p); 1494 /* always return EINTR rather than ERESTART... */ 1495 return (EINTR); 1496 } 1497 #endif /* COMPAT_43 */ 1498 1499 #if defined(COMPAT_43) 1500 #ifndef _SYS_SYSPROTO_H_ 1501 struct osigstack_args { 1502 struct sigstack *nss; 1503 struct sigstack *oss; 1504 }; 1505 #endif 1506 /* ARGSUSED */ 1507 int 1508 osigstack(td, uap) 1509 struct thread *td; 1510 register struct osigstack_args *uap; 1511 { 1512 struct sigstack nss, oss; 1513 int error = 0; 1514 1515 if (uap->nss != NULL) { 1516 error = copyin(uap->nss, &nss, sizeof(nss)); 1517 if (error) 1518 return (error); 1519 } 1520 oss.ss_sp = td->td_sigstk.ss_sp; 1521 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1522 if (uap->nss != NULL) { 1523 td->td_sigstk.ss_sp = nss.ss_sp; 1524 td->td_sigstk.ss_size = 0; 1525 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1526 td->td_pflags |= TDP_ALTSTACK; 1527 } 1528 if (uap->oss != NULL) 1529 error = copyout(&oss, uap->oss, sizeof(oss)); 1530 1531 return (error); 1532 } 1533 #endif /* COMPAT_43 */ 1534 1535 #ifndef _SYS_SYSPROTO_H_ 1536 struct sigaltstack_args { 1537 stack_t *ss; 1538 stack_t *oss; 1539 }; 1540 #endif 1541 /* ARGSUSED */ 1542 int 1543 sigaltstack(td, uap) 1544 struct thread *td; 1545 register struct sigaltstack_args *uap; 1546 { 1547 stack_t ss, oss; 1548 int error; 1549 1550 if (uap->ss != NULL) { 1551 error = copyin(uap->ss, &ss, sizeof(ss)); 1552 if (error) 1553 return (error); 1554 } 1555 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1556 (uap->oss != NULL) ? &oss : NULL); 1557 if (error) 1558 return (error); 1559 if (uap->oss != NULL) 1560 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1561 return (error); 1562 } 1563 1564 int 1565 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1566 { 1567 struct proc *p = td->td_proc; 1568 int oonstack; 1569 1570 oonstack = sigonstack(cpu_getstack(td)); 1571 1572 if (oss != NULL) { 1573 *oss = td->td_sigstk; 1574 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1575 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1576 } 1577 1578 if (ss != NULL) { 1579 if (oonstack) 1580 return (EPERM); 1581 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1582 return (EINVAL); 1583 if (!(ss->ss_flags & SS_DISABLE)) { 1584 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1585 return (ENOMEM); 1586 1587 td->td_sigstk = *ss; 1588 td->td_pflags |= TDP_ALTSTACK; 1589 } else { 1590 td->td_pflags &= ~TDP_ALTSTACK; 1591 } 1592 } 1593 return (0); 1594 } 1595 1596 /* 1597 * Common code for kill process group/broadcast kill. 1598 * cp is calling process. 1599 */ 1600 static int 1601 killpg1(td, sig, pgid, all) 1602 register struct thread *td; 1603 int sig, pgid, all; 1604 { 1605 register struct proc *p; 1606 struct pgrp *pgrp; 1607 int nfound = 0; 1608 1609 if (all) { 1610 /* 1611 * broadcast 1612 */ 1613 sx_slock(&allproc_lock); 1614 FOREACH_PROC_IN_SYSTEM(p) { 1615 PROC_LOCK(p); 1616 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1617 p == td->td_proc || p->p_state == PRS_NEW) { 1618 PROC_UNLOCK(p); 1619 continue; 1620 } 1621 if (p_cansignal(td, p, sig) == 0) { 1622 nfound++; 1623 if (sig) 1624 psignal(p, sig); 1625 } 1626 PROC_UNLOCK(p); 1627 } 1628 sx_sunlock(&allproc_lock); 1629 } else { 1630 sx_slock(&proctree_lock); 1631 if (pgid == 0) { 1632 /* 1633 * zero pgid means send to my process group. 1634 */ 1635 pgrp = td->td_proc->p_pgrp; 1636 PGRP_LOCK(pgrp); 1637 } else { 1638 pgrp = pgfind(pgid); 1639 if (pgrp == NULL) { 1640 sx_sunlock(&proctree_lock); 1641 return (ESRCH); 1642 } 1643 } 1644 sx_sunlock(&proctree_lock); 1645 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1646 PROC_LOCK(p); 1647 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1648 p->p_state == PRS_NEW ) { 1649 PROC_UNLOCK(p); 1650 continue; 1651 } 1652 if (p_cansignal(td, p, sig) == 0) { 1653 nfound++; 1654 if (sig) 1655 psignal(p, sig); 1656 } 1657 PROC_UNLOCK(p); 1658 } 1659 PGRP_UNLOCK(pgrp); 1660 } 1661 return (nfound ? 0 : ESRCH); 1662 } 1663 1664 #ifndef _SYS_SYSPROTO_H_ 1665 struct kill_args { 1666 int pid; 1667 int signum; 1668 }; 1669 #endif 1670 /* ARGSUSED */ 1671 int 1672 kill(td, uap) 1673 register struct thread *td; 1674 register struct kill_args *uap; 1675 { 1676 register struct proc *p; 1677 int error; 1678 1679 AUDIT_ARG_SIGNUM(uap->signum); 1680 AUDIT_ARG_PID(uap->pid); 1681 if ((u_int)uap->signum > _SIG_MAXSIG) 1682 return (EINVAL); 1683 1684 if (uap->pid > 0) { 1685 /* kill single process */ 1686 if ((p = pfind(uap->pid)) == NULL) { 1687 if ((p = zpfind(uap->pid)) == NULL) 1688 return (ESRCH); 1689 } 1690 AUDIT_ARG_PROCESS(p); 1691 error = p_cansignal(td, p, uap->signum); 1692 if (error == 0 && uap->signum) 1693 psignal(p, uap->signum); 1694 PROC_UNLOCK(p); 1695 return (error); 1696 } 1697 switch (uap->pid) { 1698 case -1: /* broadcast signal */ 1699 return (killpg1(td, uap->signum, 0, 1)); 1700 case 0: /* signal own process group */ 1701 return (killpg1(td, uap->signum, 0, 0)); 1702 default: /* negative explicit process group */ 1703 return (killpg1(td, uap->signum, -uap->pid, 0)); 1704 } 1705 /* NOTREACHED */ 1706 } 1707 1708 #if defined(COMPAT_43) 1709 #ifndef _SYS_SYSPROTO_H_ 1710 struct okillpg_args { 1711 int pgid; 1712 int signum; 1713 }; 1714 #endif 1715 /* ARGSUSED */ 1716 int 1717 okillpg(td, uap) 1718 struct thread *td; 1719 register struct okillpg_args *uap; 1720 { 1721 1722 AUDIT_ARG_SIGNUM(uap->signum); 1723 AUDIT_ARG_PID(uap->pgid); 1724 if ((u_int)uap->signum > _SIG_MAXSIG) 1725 return (EINVAL); 1726 1727 return (killpg1(td, uap->signum, uap->pgid, 0)); 1728 } 1729 #endif /* COMPAT_43 */ 1730 1731 #ifndef _SYS_SYSPROTO_H_ 1732 struct sigqueue_args { 1733 pid_t pid; 1734 int signum; 1735 /* union sigval */ void *value; 1736 }; 1737 #endif 1738 int 1739 sigqueue(struct thread *td, struct sigqueue_args *uap) 1740 { 1741 ksiginfo_t ksi; 1742 struct proc *p; 1743 int error; 1744 1745 if ((u_int)uap->signum > _SIG_MAXSIG) 1746 return (EINVAL); 1747 1748 /* 1749 * Specification says sigqueue can only send signal to 1750 * single process. 1751 */ 1752 if (uap->pid <= 0) 1753 return (EINVAL); 1754 1755 if ((p = pfind(uap->pid)) == NULL) { 1756 if ((p = zpfind(uap->pid)) == NULL) 1757 return (ESRCH); 1758 } 1759 error = p_cansignal(td, p, uap->signum); 1760 if (error == 0 && uap->signum != 0) { 1761 ksiginfo_init(&ksi); 1762 ksi.ksi_signo = uap->signum; 1763 ksi.ksi_code = SI_QUEUE; 1764 ksi.ksi_pid = td->td_proc->p_pid; 1765 ksi.ksi_uid = td->td_ucred->cr_ruid; 1766 ksi.ksi_value.sival_ptr = uap->value; 1767 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1768 } 1769 PROC_UNLOCK(p); 1770 return (error); 1771 } 1772 1773 /* 1774 * Send a signal to a process group. 1775 */ 1776 void 1777 gsignal(pgid, sig) 1778 int pgid, sig; 1779 { 1780 struct pgrp *pgrp; 1781 1782 if (pgid != 0) { 1783 sx_slock(&proctree_lock); 1784 pgrp = pgfind(pgid); 1785 sx_sunlock(&proctree_lock); 1786 if (pgrp != NULL) { 1787 pgsignal(pgrp, sig, 0); 1788 PGRP_UNLOCK(pgrp); 1789 } 1790 } 1791 } 1792 1793 /* 1794 * Send a signal to a process group. If checktty is 1, 1795 * limit to members which have a controlling terminal. 1796 */ 1797 void 1798 pgsignal(pgrp, sig, checkctty) 1799 struct pgrp *pgrp; 1800 int sig, checkctty; 1801 { 1802 register struct proc *p; 1803 1804 if (pgrp) { 1805 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1806 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1807 PROC_LOCK(p); 1808 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1809 psignal(p, sig); 1810 PROC_UNLOCK(p); 1811 } 1812 } 1813 } 1814 1815 /* 1816 * Send a signal caused by a trap to the current thread. If it will be 1817 * caught immediately, deliver it with correct code. Otherwise, post it 1818 * normally. 1819 */ 1820 void 1821 trapsignal(struct thread *td, ksiginfo_t *ksi) 1822 { 1823 struct sigacts *ps; 1824 struct proc *p; 1825 int sig; 1826 int code; 1827 1828 p = td->td_proc; 1829 sig = ksi->ksi_signo; 1830 code = ksi->ksi_code; 1831 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1832 1833 PROC_LOCK(p); 1834 ps = p->p_sigacts; 1835 mtx_lock(&ps->ps_mtx); 1836 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1837 !SIGISMEMBER(td->td_sigmask, sig)) { 1838 td->td_ru.ru_nsignals++; 1839 #ifdef KTRACE 1840 if (KTRPOINT(curthread, KTR_PSIG)) 1841 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1842 &td->td_sigmask, code); 1843 #endif 1844 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1845 ksi, &td->td_sigmask); 1846 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1847 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1848 SIGADDSET(td->td_sigmask, sig); 1849 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1850 /* 1851 * See kern_sigaction() for origin of this code. 1852 */ 1853 SIGDELSET(ps->ps_sigcatch, sig); 1854 if (sig != SIGCONT && 1855 sigprop(sig) & SA_IGNORE) 1856 SIGADDSET(ps->ps_sigignore, sig); 1857 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1858 } 1859 mtx_unlock(&ps->ps_mtx); 1860 } else { 1861 /* 1862 * Avoid a possible infinite loop if the thread 1863 * masking the signal or process is ignoring the 1864 * signal. 1865 */ 1866 if (kern_forcesigexit && 1867 (SIGISMEMBER(td->td_sigmask, sig) || 1868 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1869 SIGDELSET(td->td_sigmask, sig); 1870 SIGDELSET(ps->ps_sigcatch, sig); 1871 SIGDELSET(ps->ps_sigignore, sig); 1872 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1873 } 1874 mtx_unlock(&ps->ps_mtx); 1875 p->p_code = code; /* XXX for core dump/debugger */ 1876 p->p_sig = sig; /* XXX to verify code */ 1877 tdsignal(p, td, sig, ksi); 1878 } 1879 PROC_UNLOCK(p); 1880 } 1881 1882 static struct thread * 1883 sigtd(struct proc *p, int sig, int prop) 1884 { 1885 struct thread *td, *signal_td; 1886 1887 PROC_LOCK_ASSERT(p, MA_OWNED); 1888 1889 /* 1890 * Check if current thread can handle the signal without 1891 * switching context to another thread. 1892 */ 1893 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1894 return (curthread); 1895 signal_td = NULL; 1896 FOREACH_THREAD_IN_PROC(p, td) { 1897 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1898 signal_td = td; 1899 break; 1900 } 1901 } 1902 if (signal_td == NULL) 1903 signal_td = FIRST_THREAD_IN_PROC(p); 1904 return (signal_td); 1905 } 1906 1907 /* 1908 * Send the signal to the process. If the signal has an action, the action 1909 * is usually performed by the target process rather than the caller; we add 1910 * the signal to the set of pending signals for the process. 1911 * 1912 * Exceptions: 1913 * o When a stop signal is sent to a sleeping process that takes the 1914 * default action, the process is stopped without awakening it. 1915 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1916 * regardless of the signal action (eg, blocked or ignored). 1917 * 1918 * Other ignored signals are discarded immediately. 1919 * 1920 * NB: This function may be entered from the debugger via the "kill" DDB 1921 * command. There is little that can be done to mitigate the possibly messy 1922 * side effects of this unwise possibility. 1923 */ 1924 void 1925 psignal(struct proc *p, int sig) 1926 { 1927 (void) tdsignal(p, NULL, sig, NULL); 1928 } 1929 1930 int 1931 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 1932 { 1933 struct thread *td = NULL; 1934 1935 PROC_LOCK_ASSERT(p, MA_OWNED); 1936 1937 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 1938 1939 /* 1940 * ksi_code and other fields should be set before 1941 * calling this function. 1942 */ 1943 ksi->ksi_signo = sigev->sigev_signo; 1944 ksi->ksi_value = sigev->sigev_value; 1945 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1946 td = thread_find(p, sigev->sigev_notify_thread_id); 1947 if (td == NULL) 1948 return (ESRCH); 1949 } 1950 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 1951 } 1952 1953 int 1954 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 1955 { 1956 sig_t action; 1957 sigqueue_t *sigqueue; 1958 int prop; 1959 struct sigacts *ps; 1960 int intrval; 1961 int ret = 0; 1962 int wakeup_swapper; 1963 1964 PROC_LOCK_ASSERT(p, MA_OWNED); 1965 1966 if (!_SIG_VALID(sig)) 1967 panic("tdsignal(): invalid signal %d", sig); 1968 1969 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue")); 1970 1971 /* 1972 * IEEE Std 1003.1-2001: return success when killing a zombie. 1973 */ 1974 if (p->p_state == PRS_ZOMBIE) { 1975 if (ksi && (ksi->ksi_flags & KSI_INS)) 1976 ksiginfo_tryfree(ksi); 1977 return (ret); 1978 } 1979 1980 ps = p->p_sigacts; 1981 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 1982 prop = sigprop(sig); 1983 1984 /* 1985 * If the signal is blocked and not destined for this thread, then 1986 * assign it to the process so that we can find it later in the first 1987 * thread that unblocks it. Otherwise, assign it to this thread now. 1988 */ 1989 if (td == NULL) { 1990 td = sigtd(p, sig, prop); 1991 if (SIGISMEMBER(td->td_sigmask, sig)) 1992 sigqueue = &p->p_sigqueue; 1993 else 1994 sigqueue = &td->td_sigqueue; 1995 } else { 1996 KASSERT(td->td_proc == p, ("invalid thread")); 1997 sigqueue = &td->td_sigqueue; 1998 } 1999 2000 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2001 2002 /* 2003 * If the signal is being ignored, 2004 * then we forget about it immediately. 2005 * (Note: we don't set SIGCONT in ps_sigignore, 2006 * and if it is set to SIG_IGN, 2007 * action will be SIG_DFL here.) 2008 */ 2009 mtx_lock(&ps->ps_mtx); 2010 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2011 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 ); 2012 2013 mtx_unlock(&ps->ps_mtx); 2014 if (ksi && (ksi->ksi_flags & KSI_INS)) 2015 ksiginfo_tryfree(ksi); 2016 return (ret); 2017 } 2018 if (SIGISMEMBER(td->td_sigmask, sig)) 2019 action = SIG_HOLD; 2020 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2021 action = SIG_CATCH; 2022 else 2023 action = SIG_DFL; 2024 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2025 intrval = EINTR; 2026 else 2027 intrval = ERESTART; 2028 mtx_unlock(&ps->ps_mtx); 2029 2030 if (prop & SA_CONT) 2031 sigqueue_delete_stopmask_proc(p); 2032 else if (prop & SA_STOP) { 2033 /* 2034 * If sending a tty stop signal to a member of an orphaned 2035 * process group, discard the signal here if the action 2036 * is default; don't stop the process below if sleeping, 2037 * and don't clear any pending SIGCONT. 2038 */ 2039 if ((prop & SA_TTYSTOP) && 2040 (p->p_pgrp->pg_jobc == 0) && 2041 (action == SIG_DFL)) { 2042 if (ksi && (ksi->ksi_flags & KSI_INS)) 2043 ksiginfo_tryfree(ksi); 2044 return (ret); 2045 } 2046 sigqueue_delete_proc(p, SIGCONT); 2047 if (p->p_flag & P_CONTINUED) { 2048 p->p_flag &= ~P_CONTINUED; 2049 PROC_LOCK(p->p_pptr); 2050 sigqueue_take(p->p_ksi); 2051 PROC_UNLOCK(p->p_pptr); 2052 } 2053 } 2054 2055 ret = sigqueue_add(sigqueue, sig, ksi); 2056 if (ret != 0) 2057 return (ret); 2058 signotify(td); 2059 /* 2060 * Defer further processing for signals which are held, 2061 * except that stopped processes must be continued by SIGCONT. 2062 */ 2063 if (action == SIG_HOLD && 2064 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2065 return (ret); 2066 /* 2067 * SIGKILL: Remove procfs STOPEVENTs. 2068 */ 2069 if (sig == SIGKILL) { 2070 /* from procfs_ioctl.c: PIOCBIC */ 2071 p->p_stops = 0; 2072 /* from procfs_ioctl.c: PIOCCONT */ 2073 p->p_step = 0; 2074 wakeup(&p->p_step); 2075 } 2076 /* 2077 * Some signals have a process-wide effect and a per-thread 2078 * component. Most processing occurs when the process next 2079 * tries to cross the user boundary, however there are some 2080 * times when processing needs to be done immediatly, such as 2081 * waking up threads so that they can cross the user boundary. 2082 * We try do the per-process part here. 2083 */ 2084 if (P_SHOULDSTOP(p)) { 2085 /* 2086 * The process is in stopped mode. All the threads should be 2087 * either winding down or already on the suspended queue. 2088 */ 2089 if (p->p_flag & P_TRACED) { 2090 /* 2091 * The traced process is already stopped, 2092 * so no further action is necessary. 2093 * No signal can restart us. 2094 */ 2095 goto out; 2096 } 2097 2098 if (sig == SIGKILL) { 2099 /* 2100 * SIGKILL sets process running. 2101 * It will die elsewhere. 2102 * All threads must be restarted. 2103 */ 2104 p->p_flag &= ~P_STOPPED_SIG; 2105 goto runfast; 2106 } 2107 2108 if (prop & SA_CONT) { 2109 /* 2110 * If SIGCONT is default (or ignored), we continue the 2111 * process but don't leave the signal in sigqueue as 2112 * it has no further action. If SIGCONT is held, we 2113 * continue the process and leave the signal in 2114 * sigqueue. If the process catches SIGCONT, let it 2115 * handle the signal itself. If it isn't waiting on 2116 * an event, it goes back to run state. 2117 * Otherwise, process goes back to sleep state. 2118 */ 2119 p->p_flag &= ~P_STOPPED_SIG; 2120 PROC_SLOCK(p); 2121 if (p->p_numthreads == p->p_suspcount) { 2122 PROC_SUNLOCK(p); 2123 p->p_flag |= P_CONTINUED; 2124 p->p_xstat = SIGCONT; 2125 PROC_LOCK(p->p_pptr); 2126 childproc_continued(p); 2127 PROC_UNLOCK(p->p_pptr); 2128 PROC_SLOCK(p); 2129 } 2130 if (action == SIG_DFL) { 2131 thread_unsuspend(p); 2132 PROC_SUNLOCK(p); 2133 sigqueue_delete(sigqueue, sig); 2134 goto out; 2135 } 2136 if (action == SIG_CATCH) { 2137 /* 2138 * The process wants to catch it so it needs 2139 * to run at least one thread, but which one? 2140 */ 2141 PROC_SUNLOCK(p); 2142 goto runfast; 2143 } 2144 /* 2145 * The signal is not ignored or caught. 2146 */ 2147 thread_unsuspend(p); 2148 PROC_SUNLOCK(p); 2149 goto out; 2150 } 2151 2152 if (prop & SA_STOP) { 2153 /* 2154 * Already stopped, don't need to stop again 2155 * (If we did the shell could get confused). 2156 * Just make sure the signal STOP bit set. 2157 */ 2158 p->p_flag |= P_STOPPED_SIG; 2159 sigqueue_delete(sigqueue, sig); 2160 goto out; 2161 } 2162 2163 /* 2164 * All other kinds of signals: 2165 * If a thread is sleeping interruptibly, simulate a 2166 * wakeup so that when it is continued it will be made 2167 * runnable and can look at the signal. However, don't make 2168 * the PROCESS runnable, leave it stopped. 2169 * It may run a bit until it hits a thread_suspend_check(). 2170 */ 2171 wakeup_swapper = 0; 2172 PROC_SLOCK(p); 2173 thread_lock(td); 2174 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2175 wakeup_swapper = sleepq_abort(td, intrval); 2176 thread_unlock(td); 2177 PROC_SUNLOCK(p); 2178 if (wakeup_swapper) 2179 kick_proc0(); 2180 goto out; 2181 /* 2182 * Mutexes are short lived. Threads waiting on them will 2183 * hit thread_suspend_check() soon. 2184 */ 2185 } else if (p->p_state == PRS_NORMAL) { 2186 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2187 tdsigwakeup(td, sig, action, intrval); 2188 goto out; 2189 } 2190 2191 MPASS(action == SIG_DFL); 2192 2193 if (prop & SA_STOP) { 2194 if (p->p_flag & P_PPWAIT) 2195 goto out; 2196 p->p_flag |= P_STOPPED_SIG; 2197 p->p_xstat = sig; 2198 PROC_SLOCK(p); 2199 sig_suspend_threads(td, p, 1); 2200 if (p->p_numthreads == p->p_suspcount) { 2201 /* 2202 * only thread sending signal to another 2203 * process can reach here, if thread is sending 2204 * signal to its process, because thread does 2205 * not suspend itself here, p_numthreads 2206 * should never be equal to p_suspcount. 2207 */ 2208 thread_stopped(p); 2209 PROC_SUNLOCK(p); 2210 sigqueue_delete_proc(p, p->p_xstat); 2211 } else 2212 PROC_SUNLOCK(p); 2213 goto out; 2214 } 2215 } else { 2216 /* Not in "NORMAL" state. discard the signal. */ 2217 sigqueue_delete(sigqueue, sig); 2218 goto out; 2219 } 2220 2221 /* 2222 * The process is not stopped so we need to apply the signal to all the 2223 * running threads. 2224 */ 2225 runfast: 2226 tdsigwakeup(td, sig, action, intrval); 2227 PROC_SLOCK(p); 2228 thread_unsuspend(p); 2229 PROC_SUNLOCK(p); 2230 out: 2231 /* If we jump here, proc slock should not be owned. */ 2232 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2233 return (ret); 2234 } 2235 2236 /* 2237 * The force of a signal has been directed against a single 2238 * thread. We need to see what we can do about knocking it 2239 * out of any sleep it may be in etc. 2240 */ 2241 static void 2242 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2243 { 2244 struct proc *p = td->td_proc; 2245 register int prop; 2246 int wakeup_swapper; 2247 2248 wakeup_swapper = 0; 2249 PROC_LOCK_ASSERT(p, MA_OWNED); 2250 prop = sigprop(sig); 2251 2252 PROC_SLOCK(p); 2253 thread_lock(td); 2254 /* 2255 * Bring the priority of a thread up if we want it to get 2256 * killed in this lifetime. 2257 */ 2258 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2259 sched_prio(td, PUSER); 2260 if (TD_ON_SLEEPQ(td)) { 2261 /* 2262 * If thread is sleeping uninterruptibly 2263 * we can't interrupt the sleep... the signal will 2264 * be noticed when the process returns through 2265 * trap() or syscall(). 2266 */ 2267 if ((td->td_flags & TDF_SINTR) == 0) 2268 goto out; 2269 /* 2270 * If SIGCONT is default (or ignored) and process is 2271 * asleep, we are finished; the process should not 2272 * be awakened. 2273 */ 2274 if ((prop & SA_CONT) && action == SIG_DFL) { 2275 thread_unlock(td); 2276 PROC_SUNLOCK(p); 2277 sigqueue_delete(&p->p_sigqueue, sig); 2278 /* 2279 * It may be on either list in this state. 2280 * Remove from both for now. 2281 */ 2282 sigqueue_delete(&td->td_sigqueue, sig); 2283 return; 2284 } 2285 2286 /* 2287 * Give low priority threads a better chance to run. 2288 */ 2289 if (td->td_priority > PUSER) 2290 sched_prio(td, PUSER); 2291 2292 wakeup_swapper = sleepq_abort(td, intrval); 2293 } else { 2294 /* 2295 * Other states do nothing with the signal immediately, 2296 * other than kicking ourselves if we are running. 2297 * It will either never be noticed, or noticed very soon. 2298 */ 2299 #ifdef SMP 2300 if (TD_IS_RUNNING(td) && td != curthread) 2301 forward_signal(td); 2302 #endif 2303 } 2304 out: 2305 PROC_SUNLOCK(p); 2306 thread_unlock(td); 2307 if (wakeup_swapper) 2308 kick_proc0(); 2309 } 2310 2311 static void 2312 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2313 { 2314 struct thread *td2; 2315 int wakeup_swapper; 2316 2317 PROC_LOCK_ASSERT(p, MA_OWNED); 2318 PROC_SLOCK_ASSERT(p, MA_OWNED); 2319 2320 wakeup_swapper = 0; 2321 FOREACH_THREAD_IN_PROC(p, td2) { 2322 thread_lock(td2); 2323 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2324 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2325 (td2->td_flags & TDF_SINTR)) { 2326 if (td2->td_flags & TDF_SBDRY) { 2327 if (TD_IS_SUSPENDED(td2)) 2328 wakeup_swapper |= 2329 thread_unsuspend_one(td2); 2330 if (TD_ON_SLEEPQ(td2)) 2331 wakeup_swapper |= 2332 sleepq_abort(td2, ERESTART); 2333 } else if (!TD_IS_SUSPENDED(td2)) { 2334 thread_suspend_one(td2); 2335 } 2336 } else if (!TD_IS_SUSPENDED(td2)) { 2337 if (sending || td != td2) 2338 td2->td_flags |= TDF_ASTPENDING; 2339 #ifdef SMP 2340 if (TD_IS_RUNNING(td2) && td2 != td) 2341 forward_signal(td2); 2342 #endif 2343 } 2344 thread_unlock(td2); 2345 } 2346 if (wakeup_swapper) 2347 kick_proc0(); 2348 } 2349 2350 int 2351 ptracestop(struct thread *td, int sig) 2352 { 2353 struct proc *p = td->td_proc; 2354 2355 PROC_LOCK_ASSERT(p, MA_OWNED); 2356 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2357 &p->p_mtx.lock_object, "Stopping for traced signal"); 2358 2359 td->td_dbgflags |= TDB_XSIG; 2360 td->td_xsig = sig; 2361 PROC_SLOCK(p); 2362 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2363 if (p->p_flag & P_SINGLE_EXIT) { 2364 td->td_dbgflags &= ~TDB_XSIG; 2365 PROC_SUNLOCK(p); 2366 return (sig); 2367 } 2368 /* 2369 * Just make wait() to work, the last stopped thread 2370 * will win. 2371 */ 2372 p->p_xstat = sig; 2373 p->p_xthread = td; 2374 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2375 sig_suspend_threads(td, p, 0); 2376 stopme: 2377 thread_suspend_switch(td); 2378 if (!(p->p_flag & P_TRACED)) { 2379 break; 2380 } 2381 if (td->td_dbgflags & TDB_SUSPEND) { 2382 if (p->p_flag & P_SINGLE_EXIT) 2383 break; 2384 goto stopme; 2385 } 2386 } 2387 PROC_SUNLOCK(p); 2388 return (td->td_xsig); 2389 } 2390 2391 /* 2392 * If the current process has received a signal (should be caught or cause 2393 * termination, should interrupt current syscall), return the signal number. 2394 * Stop signals with default action are processed immediately, then cleared; 2395 * they aren't returned. This is checked after each entry to the system for 2396 * a syscall or trap (though this can usually be done without calling issignal 2397 * by checking the pending signal masks in cursig.) The normal call 2398 * sequence is 2399 * 2400 * while (sig = cursig(curthread)) 2401 * postsig(sig); 2402 */ 2403 static int 2404 issignal(struct thread *td, int stop_allowed) 2405 { 2406 struct proc *p; 2407 struct sigacts *ps; 2408 sigset_t sigpending; 2409 int sig, prop, newsig; 2410 2411 p = td->td_proc; 2412 ps = p->p_sigacts; 2413 mtx_assert(&ps->ps_mtx, MA_OWNED); 2414 PROC_LOCK_ASSERT(p, MA_OWNED); 2415 for (;;) { 2416 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2417 2418 sigpending = td->td_sigqueue.sq_signals; 2419 SIGSETNAND(sigpending, td->td_sigmask); 2420 2421 if (p->p_flag & P_PPWAIT) 2422 SIG_STOPSIGMASK(sigpending); 2423 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2424 return (0); 2425 sig = sig_ffs(&sigpending); 2426 2427 if (p->p_stops & S_SIG) { 2428 mtx_unlock(&ps->ps_mtx); 2429 stopevent(p, S_SIG, sig); 2430 mtx_lock(&ps->ps_mtx); 2431 } 2432 2433 /* 2434 * We should see pending but ignored signals 2435 * only if P_TRACED was on when they were posted. 2436 */ 2437 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2438 sigqueue_delete(&td->td_sigqueue, sig); 2439 continue; 2440 } 2441 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2442 /* 2443 * If traced, always stop. 2444 */ 2445 mtx_unlock(&ps->ps_mtx); 2446 newsig = ptracestop(td, sig); 2447 mtx_lock(&ps->ps_mtx); 2448 2449 if (sig != newsig) { 2450 ksiginfo_t ksi; 2451 /* 2452 * clear old signal. 2453 * XXX shrug off debugger, it causes siginfo to 2454 * be thrown away. 2455 */ 2456 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2457 2458 /* 2459 * If parent wants us to take the signal, 2460 * then it will leave it in p->p_xstat; 2461 * otherwise we just look for signals again. 2462 */ 2463 if (newsig == 0) 2464 continue; 2465 sig = newsig; 2466 2467 /* 2468 * Put the new signal into td_sigqueue. If the 2469 * signal is being masked, look for other signals. 2470 */ 2471 SIGADDSET(td->td_sigqueue.sq_signals, sig); 2472 if (SIGISMEMBER(td->td_sigmask, sig)) 2473 continue; 2474 signotify(td); 2475 } 2476 2477 /* 2478 * If the traced bit got turned off, go back up 2479 * to the top to rescan signals. This ensures 2480 * that p_sig* and p_sigact are consistent. 2481 */ 2482 if ((p->p_flag & P_TRACED) == 0) 2483 continue; 2484 } 2485 2486 prop = sigprop(sig); 2487 2488 /* 2489 * Decide whether the signal should be returned. 2490 * Return the signal's number, or fall through 2491 * to clear it from the pending mask. 2492 */ 2493 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2494 2495 case (intptr_t)SIG_DFL: 2496 /* 2497 * Don't take default actions on system processes. 2498 */ 2499 if (p->p_pid <= 1) { 2500 #ifdef DIAGNOSTIC 2501 /* 2502 * Are you sure you want to ignore SIGSEGV 2503 * in init? XXX 2504 */ 2505 printf("Process (pid %lu) got signal %d\n", 2506 (u_long)p->p_pid, sig); 2507 #endif 2508 break; /* == ignore */ 2509 } 2510 /* 2511 * If there is a pending stop signal to process 2512 * with default action, stop here, 2513 * then clear the signal. However, 2514 * if process is member of an orphaned 2515 * process group, ignore tty stop signals. 2516 */ 2517 if (prop & SA_STOP) { 2518 if (p->p_flag & P_TRACED || 2519 (p->p_pgrp->pg_jobc == 0 && 2520 prop & SA_TTYSTOP)) 2521 break; /* == ignore */ 2522 2523 /* Ignore, but do not drop the stop signal. */ 2524 if (stop_allowed != SIG_STOP_ALLOWED) 2525 return (sig); 2526 mtx_unlock(&ps->ps_mtx); 2527 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2528 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2529 p->p_flag |= P_STOPPED_SIG; 2530 p->p_xstat = sig; 2531 PROC_SLOCK(p); 2532 sig_suspend_threads(td, p, 0); 2533 thread_suspend_switch(td); 2534 PROC_SUNLOCK(p); 2535 mtx_lock(&ps->ps_mtx); 2536 break; 2537 } else if (prop & SA_IGNORE) { 2538 /* 2539 * Except for SIGCONT, shouldn't get here. 2540 * Default action is to ignore; drop it. 2541 */ 2542 break; /* == ignore */ 2543 } else 2544 return (sig); 2545 /*NOTREACHED*/ 2546 2547 case (intptr_t)SIG_IGN: 2548 /* 2549 * Masking above should prevent us ever trying 2550 * to take action on an ignored signal other 2551 * than SIGCONT, unless process is traced. 2552 */ 2553 if ((prop & SA_CONT) == 0 && 2554 (p->p_flag & P_TRACED) == 0) 2555 printf("issignal\n"); 2556 break; /* == ignore */ 2557 2558 default: 2559 /* 2560 * This signal has an action, let 2561 * postsig() process it. 2562 */ 2563 return (sig); 2564 } 2565 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2566 } 2567 /* NOTREACHED */ 2568 } 2569 2570 void 2571 thread_stopped(struct proc *p) 2572 { 2573 int n; 2574 2575 PROC_LOCK_ASSERT(p, MA_OWNED); 2576 PROC_SLOCK_ASSERT(p, MA_OWNED); 2577 n = p->p_suspcount; 2578 if (p == curproc) 2579 n++; 2580 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2581 PROC_SUNLOCK(p); 2582 p->p_flag &= ~P_WAITED; 2583 PROC_LOCK(p->p_pptr); 2584 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2585 CLD_TRAPPED : CLD_STOPPED); 2586 PROC_UNLOCK(p->p_pptr); 2587 PROC_SLOCK(p); 2588 } 2589 } 2590 2591 /* 2592 * Take the action for the specified signal 2593 * from the current set of pending signals. 2594 */ 2595 void 2596 postsig(sig) 2597 register int sig; 2598 { 2599 struct thread *td = curthread; 2600 register struct proc *p = td->td_proc; 2601 struct sigacts *ps; 2602 sig_t action; 2603 ksiginfo_t ksi; 2604 sigset_t returnmask; 2605 2606 KASSERT(sig != 0, ("postsig")); 2607 2608 PROC_LOCK_ASSERT(p, MA_OWNED); 2609 ps = p->p_sigacts; 2610 mtx_assert(&ps->ps_mtx, MA_OWNED); 2611 ksiginfo_init(&ksi); 2612 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2613 ksi.ksi_signo = sig; 2614 if (ksi.ksi_code == SI_TIMER) 2615 itimer_accept(p, ksi.ksi_timerid, &ksi); 2616 action = ps->ps_sigact[_SIG_IDX(sig)]; 2617 #ifdef KTRACE 2618 if (KTRPOINT(td, KTR_PSIG)) 2619 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2620 &td->td_oldsigmask : &td->td_sigmask, 0); 2621 #endif 2622 if (p->p_stops & S_SIG) { 2623 mtx_unlock(&ps->ps_mtx); 2624 stopevent(p, S_SIG, sig); 2625 mtx_lock(&ps->ps_mtx); 2626 } 2627 2628 if (action == SIG_DFL) { 2629 /* 2630 * Default action, where the default is to kill 2631 * the process. (Other cases were ignored above.) 2632 */ 2633 mtx_unlock(&ps->ps_mtx); 2634 sigexit(td, sig); 2635 /* NOTREACHED */ 2636 } else { 2637 /* 2638 * If we get here, the signal must be caught. 2639 */ 2640 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2641 ("postsig action")); 2642 /* 2643 * Set the new mask value and also defer further 2644 * occurrences of this signal. 2645 * 2646 * Special case: user has done a sigsuspend. Here the 2647 * current mask is not of interest, but rather the 2648 * mask from before the sigsuspend is what we want 2649 * restored after the signal processing is completed. 2650 */ 2651 if (td->td_pflags & TDP_OLDMASK) { 2652 returnmask = td->td_oldsigmask; 2653 td->td_pflags &= ~TDP_OLDMASK; 2654 } else 2655 returnmask = td->td_sigmask; 2656 2657 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2658 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2659 SIGADDSET(td->td_sigmask, sig); 2660 2661 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2662 /* 2663 * See kern_sigaction() for origin of this code. 2664 */ 2665 SIGDELSET(ps->ps_sigcatch, sig); 2666 if (sig != SIGCONT && 2667 sigprop(sig) & SA_IGNORE) 2668 SIGADDSET(ps->ps_sigignore, sig); 2669 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2670 } 2671 td->td_ru.ru_nsignals++; 2672 if (p->p_sig == sig) { 2673 p->p_code = 0; 2674 p->p_sig = 0; 2675 } 2676 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2677 } 2678 } 2679 2680 /* 2681 * Kill the current process for stated reason. 2682 */ 2683 void 2684 killproc(p, why) 2685 struct proc *p; 2686 char *why; 2687 { 2688 2689 PROC_LOCK_ASSERT(p, MA_OWNED); 2690 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2691 p, p->p_pid, p->p_comm); 2692 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2693 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2694 psignal(p, SIGKILL); 2695 } 2696 2697 /* 2698 * Force the current process to exit with the specified signal, dumping core 2699 * if appropriate. We bypass the normal tests for masked and caught signals, 2700 * allowing unrecoverable failures to terminate the process without changing 2701 * signal state. Mark the accounting record with the signal termination. 2702 * If dumping core, save the signal number for the debugger. Calls exit and 2703 * does not return. 2704 */ 2705 void 2706 sigexit(td, sig) 2707 struct thread *td; 2708 int sig; 2709 { 2710 struct proc *p = td->td_proc; 2711 2712 PROC_LOCK_ASSERT(p, MA_OWNED); 2713 p->p_acflag |= AXSIG; 2714 /* 2715 * We must be single-threading to generate a core dump. This 2716 * ensures that the registers in the core file are up-to-date. 2717 * Also, the ELF dump handler assumes that the thread list doesn't 2718 * change out from under it. 2719 * 2720 * XXX If another thread attempts to single-thread before us 2721 * (e.g. via fork()), we won't get a dump at all. 2722 */ 2723 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2724 p->p_sig = sig; 2725 /* 2726 * Log signals which would cause core dumps 2727 * (Log as LOG_INFO to appease those who don't want 2728 * these messages.) 2729 * XXX : Todo, as well as euid, write out ruid too 2730 * Note that coredump() drops proc lock. 2731 */ 2732 if (coredump(td) == 0) 2733 sig |= WCOREFLAG; 2734 if (kern_logsigexit) 2735 log(LOG_INFO, 2736 "pid %d (%s), uid %d: exited on signal %d%s\n", 2737 p->p_pid, p->p_comm, 2738 td->td_ucred ? td->td_ucred->cr_uid : -1, 2739 sig &~ WCOREFLAG, 2740 sig & WCOREFLAG ? " (core dumped)" : ""); 2741 } else 2742 PROC_UNLOCK(p); 2743 exit1(td, W_EXITCODE(0, sig)); 2744 /* NOTREACHED */ 2745 } 2746 2747 /* 2748 * Send queued SIGCHLD to parent when child process's state 2749 * is changed. 2750 */ 2751 static void 2752 sigparent(struct proc *p, int reason, int status) 2753 { 2754 PROC_LOCK_ASSERT(p, MA_OWNED); 2755 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2756 2757 if (p->p_ksi != NULL) { 2758 p->p_ksi->ksi_signo = SIGCHLD; 2759 p->p_ksi->ksi_code = reason; 2760 p->p_ksi->ksi_status = status; 2761 p->p_ksi->ksi_pid = p->p_pid; 2762 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2763 if (KSI_ONQ(p->p_ksi)) 2764 return; 2765 } 2766 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2767 } 2768 2769 static void 2770 childproc_jobstate(struct proc *p, int reason, int status) 2771 { 2772 struct sigacts *ps; 2773 2774 PROC_LOCK_ASSERT(p, MA_OWNED); 2775 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2776 2777 /* 2778 * Wake up parent sleeping in kern_wait(), also send 2779 * SIGCHLD to parent, but SIGCHLD does not guarantee 2780 * that parent will awake, because parent may masked 2781 * the signal. 2782 */ 2783 p->p_pptr->p_flag |= P_STATCHILD; 2784 wakeup(p->p_pptr); 2785 2786 ps = p->p_pptr->p_sigacts; 2787 mtx_lock(&ps->ps_mtx); 2788 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2789 mtx_unlock(&ps->ps_mtx); 2790 sigparent(p, reason, status); 2791 } else 2792 mtx_unlock(&ps->ps_mtx); 2793 } 2794 2795 void 2796 childproc_stopped(struct proc *p, int reason) 2797 { 2798 childproc_jobstate(p, reason, p->p_xstat); 2799 } 2800 2801 void 2802 childproc_continued(struct proc *p) 2803 { 2804 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2805 } 2806 2807 void 2808 childproc_exited(struct proc *p) 2809 { 2810 int reason; 2811 int status = p->p_xstat; /* convert to int */ 2812 2813 reason = CLD_EXITED; 2814 if (WCOREDUMP(status)) 2815 reason = CLD_DUMPED; 2816 else if (WIFSIGNALED(status)) 2817 reason = CLD_KILLED; 2818 /* 2819 * XXX avoid calling wakeup(p->p_pptr), the work is 2820 * done in exit1(). 2821 */ 2822 sigparent(p, reason, status); 2823 } 2824 2825 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2826 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2827 sizeof(corefilename), "process corefile name format string"); 2828 2829 /* 2830 * expand_name(name, uid, pid) 2831 * Expand the name described in corefilename, using name, uid, and pid. 2832 * corefilename is a printf-like string, with three format specifiers: 2833 * %N name of process ("name") 2834 * %P process id (pid) 2835 * %U user id (uid) 2836 * For example, "%N.core" is the default; they can be disabled completely 2837 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2838 * This is controlled by the sysctl variable kern.corefile (see above). 2839 */ 2840 static char * 2841 expand_name(name, uid, pid) 2842 const char *name; 2843 uid_t uid; 2844 pid_t pid; 2845 { 2846 struct sbuf sb; 2847 const char *format; 2848 char *temp; 2849 size_t i; 2850 2851 format = corefilename; 2852 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2853 if (temp == NULL) 2854 return (NULL); 2855 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 2856 for (i = 0; format[i]; i++) { 2857 switch (format[i]) { 2858 case '%': /* Format character */ 2859 i++; 2860 switch (format[i]) { 2861 case '%': 2862 sbuf_putc(&sb, '%'); 2863 break; 2864 case 'N': /* process name */ 2865 sbuf_printf(&sb, "%s", name); 2866 break; 2867 case 'P': /* process id */ 2868 sbuf_printf(&sb, "%u", pid); 2869 break; 2870 case 'U': /* user id */ 2871 sbuf_printf(&sb, "%u", uid); 2872 break; 2873 default: 2874 log(LOG_ERR, 2875 "Unknown format character %c in " 2876 "corename `%s'\n", format[i], format); 2877 } 2878 break; 2879 default: 2880 sbuf_putc(&sb, format[i]); 2881 } 2882 } 2883 if (sbuf_overflowed(&sb)) { 2884 sbuf_delete(&sb); 2885 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 2886 "long\n", (long)pid, name, (u_long)uid); 2887 free(temp, M_TEMP); 2888 return (NULL); 2889 } 2890 sbuf_finish(&sb); 2891 sbuf_delete(&sb); 2892 return (temp); 2893 } 2894 2895 /* 2896 * Dump a process' core. The main routine does some 2897 * policy checking, and creates the name of the coredump; 2898 * then it passes on a vnode and a size limit to the process-specific 2899 * coredump routine if there is one; if there _is not_ one, it returns 2900 * ENOSYS; otherwise it returns the error from the process-specific routine. 2901 */ 2902 2903 static int 2904 coredump(struct thread *td) 2905 { 2906 struct proc *p = td->td_proc; 2907 register struct vnode *vp; 2908 register struct ucred *cred = td->td_ucred; 2909 struct flock lf; 2910 struct nameidata nd; 2911 struct vattr vattr; 2912 int error, error1, flags, locked; 2913 struct mount *mp; 2914 char *name; /* name of corefile */ 2915 off_t limit; 2916 int vfslocked; 2917 2918 PROC_LOCK_ASSERT(p, MA_OWNED); 2919 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 2920 _STOPEVENT(p, S_CORE, 0); 2921 2922 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2923 if (name == NULL) { 2924 PROC_UNLOCK(p); 2925 #ifdef AUDIT 2926 audit_proc_coredump(td, NULL, EINVAL); 2927 #endif 2928 return (EINVAL); 2929 } 2930 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2931 PROC_UNLOCK(p); 2932 #ifdef AUDIT 2933 audit_proc_coredump(td, name, EFAULT); 2934 #endif 2935 free(name, M_TEMP); 2936 return (EFAULT); 2937 } 2938 2939 /* 2940 * Note that the bulk of limit checking is done after 2941 * the corefile is created. The exception is if the limit 2942 * for corefiles is 0, in which case we don't bother 2943 * creating the corefile at all. This layout means that 2944 * a corefile is truncated instead of not being created, 2945 * if it is larger than the limit. 2946 */ 2947 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2948 PROC_UNLOCK(p); 2949 if (limit == 0) { 2950 #ifdef AUDIT 2951 audit_proc_coredump(td, name, EFBIG); 2952 #endif 2953 free(name, M_TEMP); 2954 return (EFBIG); 2955 } 2956 2957 restart: 2958 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 2959 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2960 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 2961 cred, NULL); 2962 if (error) { 2963 #ifdef AUDIT 2964 audit_proc_coredump(td, name, error); 2965 #endif 2966 free(name, M_TEMP); 2967 return (error); 2968 } 2969 vfslocked = NDHASGIANT(&nd); 2970 NDFREE(&nd, NDF_ONLY_PNBUF); 2971 vp = nd.ni_vp; 2972 2973 /* Don't dump to non-regular files or files with links. */ 2974 if (vp->v_type != VREG || 2975 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 2976 VOP_UNLOCK(vp, 0); 2977 error = EFAULT; 2978 goto close; 2979 } 2980 2981 VOP_UNLOCK(vp, 0); 2982 lf.l_whence = SEEK_SET; 2983 lf.l_start = 0; 2984 lf.l_len = 0; 2985 lf.l_type = F_WRLCK; 2986 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2987 2988 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2989 lf.l_type = F_UNLCK; 2990 if (locked) 2991 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2992 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2993 goto out; 2994 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2995 goto out; 2996 VFS_UNLOCK_GIANT(vfslocked); 2997 goto restart; 2998 } 2999 3000 VATTR_NULL(&vattr); 3001 vattr.va_size = 0; 3002 if (set_core_nodump_flag) 3003 vattr.va_flags = UF_NODUMP; 3004 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3005 VOP_SETATTR(vp, &vattr, cred); 3006 VOP_UNLOCK(vp, 0); 3007 vn_finished_write(mp); 3008 PROC_LOCK(p); 3009 p->p_acflag |= ACORE; 3010 PROC_UNLOCK(p); 3011 3012 error = p->p_sysent->sv_coredump ? 3013 p->p_sysent->sv_coredump(td, vp, limit) : 3014 ENOSYS; 3015 3016 if (locked) { 3017 lf.l_type = F_UNLCK; 3018 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3019 } 3020 close: 3021 error1 = vn_close(vp, FWRITE, cred, td); 3022 if (error == 0) 3023 error = error1; 3024 out: 3025 #ifdef AUDIT 3026 audit_proc_coredump(td, name, error); 3027 #endif 3028 free(name, M_TEMP); 3029 VFS_UNLOCK_GIANT(vfslocked); 3030 return (error); 3031 } 3032 3033 /* 3034 * Nonexistent system call-- signal process (may want to handle it). Flag 3035 * error in case process won't see signal immediately (blocked or ignored). 3036 */ 3037 #ifndef _SYS_SYSPROTO_H_ 3038 struct nosys_args { 3039 int dummy; 3040 }; 3041 #endif 3042 /* ARGSUSED */ 3043 int 3044 nosys(td, args) 3045 struct thread *td; 3046 struct nosys_args *args; 3047 { 3048 struct proc *p = td->td_proc; 3049 3050 PROC_LOCK(p); 3051 psignal(p, SIGSYS); 3052 PROC_UNLOCK(p); 3053 return (ENOSYS); 3054 } 3055 3056 /* 3057 * Send a SIGIO or SIGURG signal to a process or process group using stored 3058 * credentials rather than those of the current process. 3059 */ 3060 void 3061 pgsigio(sigiop, sig, checkctty) 3062 struct sigio **sigiop; 3063 int sig, checkctty; 3064 { 3065 struct sigio *sigio; 3066 3067 SIGIO_LOCK(); 3068 sigio = *sigiop; 3069 if (sigio == NULL) { 3070 SIGIO_UNLOCK(); 3071 return; 3072 } 3073 if (sigio->sio_pgid > 0) { 3074 PROC_LOCK(sigio->sio_proc); 3075 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3076 psignal(sigio->sio_proc, sig); 3077 PROC_UNLOCK(sigio->sio_proc); 3078 } else if (sigio->sio_pgid < 0) { 3079 struct proc *p; 3080 3081 PGRP_LOCK(sigio->sio_pgrp); 3082 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3083 PROC_LOCK(p); 3084 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3085 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3086 psignal(p, sig); 3087 PROC_UNLOCK(p); 3088 } 3089 PGRP_UNLOCK(sigio->sio_pgrp); 3090 } 3091 SIGIO_UNLOCK(); 3092 } 3093 3094 static int 3095 filt_sigattach(struct knote *kn) 3096 { 3097 struct proc *p = curproc; 3098 3099 kn->kn_ptr.p_proc = p; 3100 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3101 3102 knlist_add(&p->p_klist, kn, 0); 3103 3104 return (0); 3105 } 3106 3107 static void 3108 filt_sigdetach(struct knote *kn) 3109 { 3110 struct proc *p = kn->kn_ptr.p_proc; 3111 3112 knlist_remove(&p->p_klist, kn, 0); 3113 } 3114 3115 /* 3116 * signal knotes are shared with proc knotes, so we apply a mask to 3117 * the hint in order to differentiate them from process hints. This 3118 * could be avoided by using a signal-specific knote list, but probably 3119 * isn't worth the trouble. 3120 */ 3121 static int 3122 filt_signal(struct knote *kn, long hint) 3123 { 3124 3125 if (hint & NOTE_SIGNAL) { 3126 hint &= ~NOTE_SIGNAL; 3127 3128 if (kn->kn_id == hint) 3129 kn->kn_data++; 3130 } 3131 return (kn->kn_data != 0); 3132 } 3133 3134 struct sigacts * 3135 sigacts_alloc(void) 3136 { 3137 struct sigacts *ps; 3138 3139 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3140 ps->ps_refcnt = 1; 3141 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3142 return (ps); 3143 } 3144 3145 void 3146 sigacts_free(struct sigacts *ps) 3147 { 3148 3149 mtx_lock(&ps->ps_mtx); 3150 ps->ps_refcnt--; 3151 if (ps->ps_refcnt == 0) { 3152 mtx_destroy(&ps->ps_mtx); 3153 free(ps, M_SUBPROC); 3154 } else 3155 mtx_unlock(&ps->ps_mtx); 3156 } 3157 3158 struct sigacts * 3159 sigacts_hold(struct sigacts *ps) 3160 { 3161 mtx_lock(&ps->ps_mtx); 3162 ps->ps_refcnt++; 3163 mtx_unlock(&ps->ps_mtx); 3164 return (ps); 3165 } 3166 3167 void 3168 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3169 { 3170 3171 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3172 mtx_lock(&src->ps_mtx); 3173 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3174 mtx_unlock(&src->ps_mtx); 3175 } 3176 3177 int 3178 sigacts_shared(struct sigacts *ps) 3179 { 3180 int shared; 3181 3182 mtx_lock(&ps->ps_mtx); 3183 shared = ps->ps_refcnt > 1; 3184 mtx_unlock(&ps->ps_mtx); 3185 return (shared); 3186 }
Cache object: 039f53f2933cd3993537f58990d49d95
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