1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 #include "opt_core.h" 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/condvar.h> 51 #include <sys/event.h> 52 #include <sys/fcntl.h> 53 #include <sys/imgact.h> 54 #include <sys/kernel.h> 55 #include <sys/ktr.h> 56 #include <sys/ktrace.h> 57 #include <sys/lock.h> 58 #include <sys/malloc.h> 59 #include <sys/mutex.h> 60 #include <sys/namei.h> 61 #include <sys/proc.h> 62 #include <sys/posix4.h> 63 #include <sys/pioctl.h> 64 #include <sys/resourcevar.h> 65 #include <sys/sdt.h> 66 #include <sys/sbuf.h> 67 #include <sys/sleepqueue.h> 68 #include <sys/smp.h> 69 #include <sys/stat.h> 70 #include <sys/sx.h> 71 #include <sys/syscallsubr.h> 72 #include <sys/sysctl.h> 73 #include <sys/sysent.h> 74 #include <sys/syslog.h> 75 #include <sys/sysproto.h> 76 #include <sys/timers.h> 77 #include <sys/unistd.h> 78 #include <sys/wait.h> 79 #include <vm/vm.h> 80 #include <vm/vm_extern.h> 81 #include <vm/uma.h> 82 83 #include <sys/jail.h> 84 85 #include <machine/cpu.h> 86 87 #include <security/audit/audit.h> 88 89 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 90 91 SDT_PROVIDER_DECLARE(proc); 92 SDT_PROBE_DEFINE(proc, kernel, , signal_send, signal-send); 93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 95 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 96 SDT_PROBE_DEFINE(proc, kernel, , signal_clear, signal-clear); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 99 SDT_PROBE_DEFINE(proc, kernel, , signal_discard, signal-discard); 100 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 101 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 102 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 103 104 static int coredump(struct thread *); 105 static char *expand_name(const char *, uid_t, pid_t, struct thread *, int); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td, int stop_allowed); 109 static int sigprop(int sig); 110 static void tdsigwakeup(struct thread *, int, sig_t, int); 111 static void sig_suspend_threads(struct thread *, struct proc *, int); 112 static int filt_sigattach(struct knote *kn); 113 static void filt_sigdetach(struct knote *kn); 114 static int filt_signal(struct knote *kn, long hint); 115 static struct thread *sigtd(struct proc *p, int sig, int prop); 116 static void sigqueue_start(void); 117 118 static uma_zone_t ksiginfo_zone = NULL; 119 struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124 }; 125 126 static int kern_logsigexit = 1; 127 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131 static int kern_forcesigexit = 1; 132 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 136 137 static int max_pending_per_proc = 128; 138 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 139 &max_pending_per_proc, 0, "Max pending signals per proc"); 140 141 static int preallocate_siginfo = 1024; 142 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 155 156 /* 157 * Policy -- Can ucred cr1 send SIGIO to process cr2? 158 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 159 * in the right situations. 160 */ 161 #define CANSIGIO(cr1, cr2) \ 162 ((cr1)->cr_uid == 0 || \ 163 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 164 (cr1)->cr_uid == (cr2)->cr_ruid || \ 165 (cr1)->cr_ruid == (cr2)->cr_uid || \ 166 (cr1)->cr_uid == (cr2)->cr_uid) 167 168 static int 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 do_coredump = 1; 173 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 174 &do_coredump, 0, "Enable/Disable coredumps"); 175 176 static int set_core_nodump_flag = 0; 177 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 178 0, "Enable setting the NODUMP flag on coredump files"); 179 180 /* 181 * Signal properties and actions. 182 * The array below categorizes the signals and their default actions 183 * according to the following properties: 184 */ 185 #define SA_KILL 0x01 /* terminates process by default */ 186 #define SA_CORE 0x02 /* ditto and coredumps */ 187 #define SA_STOP 0x04 /* suspend process */ 188 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 189 #define SA_IGNORE 0x10 /* ignore by default */ 190 #define SA_CONT 0x20 /* continue if suspended */ 191 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 192 #define SA_PROC 0x80 /* deliverable to any thread */ 193 194 static int sigproptbl[NSIG] = { 195 SA_KILL|SA_PROC, /* SIGHUP */ 196 SA_KILL|SA_PROC, /* SIGINT */ 197 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 198 SA_KILL|SA_CORE, /* SIGILL */ 199 SA_KILL|SA_CORE, /* SIGTRAP */ 200 SA_KILL|SA_CORE, /* SIGABRT */ 201 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 202 SA_KILL|SA_CORE, /* SIGFPE */ 203 SA_KILL|SA_PROC, /* SIGKILL */ 204 SA_KILL|SA_CORE, /* SIGBUS */ 205 SA_KILL|SA_CORE, /* SIGSEGV */ 206 SA_KILL|SA_CORE, /* SIGSYS */ 207 SA_KILL|SA_PROC, /* SIGPIPE */ 208 SA_KILL|SA_PROC, /* SIGALRM */ 209 SA_KILL|SA_PROC, /* SIGTERM */ 210 SA_IGNORE|SA_PROC, /* SIGURG */ 211 SA_STOP|SA_PROC, /* SIGSTOP */ 212 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 213 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 214 SA_IGNORE|SA_PROC, /* SIGCHLD */ 215 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 216 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 217 SA_IGNORE|SA_PROC, /* SIGIO */ 218 SA_KILL, /* SIGXCPU */ 219 SA_KILL, /* SIGXFSZ */ 220 SA_KILL|SA_PROC, /* SIGVTALRM */ 221 SA_KILL|SA_PROC, /* SIGPROF */ 222 SA_IGNORE|SA_PROC, /* SIGWINCH */ 223 SA_IGNORE|SA_PROC, /* SIGINFO */ 224 SA_KILL|SA_PROC, /* SIGUSR1 */ 225 SA_KILL|SA_PROC, /* SIGUSR2 */ 226 }; 227 228 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 229 230 static void 231 sigqueue_start(void) 232 { 233 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 234 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 235 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 236 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 237 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 238 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 239 } 240 241 ksiginfo_t * 242 ksiginfo_alloc(int wait) 243 { 244 int flags; 245 246 flags = M_ZERO; 247 if (! wait) 248 flags |= M_NOWAIT; 249 if (ksiginfo_zone != NULL) 250 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 251 return (NULL); 252 } 253 254 void 255 ksiginfo_free(ksiginfo_t *ksi) 256 { 257 uma_zfree(ksiginfo_zone, ksi); 258 } 259 260 static __inline int 261 ksiginfo_tryfree(ksiginfo_t *ksi) 262 { 263 if (!(ksi->ksi_flags & KSI_EXT)) { 264 uma_zfree(ksiginfo_zone, ksi); 265 return (1); 266 } 267 return (0); 268 } 269 270 void 271 sigqueue_init(sigqueue_t *list, struct proc *p) 272 { 273 SIGEMPTYSET(list->sq_signals); 274 SIGEMPTYSET(list->sq_kill); 275 TAILQ_INIT(&list->sq_list); 276 list->sq_proc = p; 277 list->sq_flags = SQ_INIT; 278 } 279 280 /* 281 * Get a signal's ksiginfo. 282 * Return: 283 * 0 - signal not found 284 * others - signal number 285 */ 286 static int 287 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 288 { 289 struct proc *p = sq->sq_proc; 290 struct ksiginfo *ksi, *next; 291 int count = 0; 292 293 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 294 295 if (!SIGISMEMBER(sq->sq_signals, signo)) 296 return (0); 297 298 if (SIGISMEMBER(sq->sq_kill, signo)) { 299 count++; 300 SIGDELSET(sq->sq_kill, signo); 301 } 302 303 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 304 if (ksi->ksi_signo == signo) { 305 if (count == 0) { 306 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 307 ksi->ksi_sigq = NULL; 308 ksiginfo_copy(ksi, si); 309 if (ksiginfo_tryfree(ksi) && p != NULL) 310 p->p_pendingcnt--; 311 } 312 if (++count > 1) 313 break; 314 } 315 } 316 317 if (count <= 1) 318 SIGDELSET(sq->sq_signals, signo); 319 si->ksi_signo = signo; 320 return (signo); 321 } 322 323 void 324 sigqueue_take(ksiginfo_t *ksi) 325 { 326 struct ksiginfo *kp; 327 struct proc *p; 328 sigqueue_t *sq; 329 330 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 331 return; 332 333 p = sq->sq_proc; 334 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 335 ksi->ksi_sigq = NULL; 336 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 337 p->p_pendingcnt--; 338 339 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 340 kp = TAILQ_NEXT(kp, ksi_link)) { 341 if (kp->ksi_signo == ksi->ksi_signo) 342 break; 343 } 344 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 345 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 346 } 347 348 static int 349 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 350 { 351 struct proc *p = sq->sq_proc; 352 struct ksiginfo *ksi; 353 int ret = 0; 354 355 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 356 357 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 358 SIGADDSET(sq->sq_kill, signo); 359 goto out_set_bit; 360 } 361 362 /* directly insert the ksi, don't copy it */ 363 if (si->ksi_flags & KSI_INS) { 364 if (si->ksi_flags & KSI_HEAD) 365 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 366 else 367 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 368 si->ksi_sigq = sq; 369 goto out_set_bit; 370 } 371 372 if (__predict_false(ksiginfo_zone == NULL)) { 373 SIGADDSET(sq->sq_kill, signo); 374 goto out_set_bit; 375 } 376 377 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 378 signal_overflow++; 379 ret = EAGAIN; 380 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 381 signal_alloc_fail++; 382 ret = EAGAIN; 383 } else { 384 if (p != NULL) 385 p->p_pendingcnt++; 386 ksiginfo_copy(si, ksi); 387 ksi->ksi_signo = signo; 388 if (si->ksi_flags & KSI_HEAD) 389 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 390 else 391 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 392 ksi->ksi_sigq = sq; 393 } 394 395 if ((si->ksi_flags & KSI_TRAP) != 0 || 396 (si->ksi_flags & KSI_SIGQ) == 0) { 397 if (ret != 0) 398 SIGADDSET(sq->sq_kill, signo); 399 ret = 0; 400 goto out_set_bit; 401 } 402 403 if (ret != 0) 404 return (ret); 405 406 out_set_bit: 407 SIGADDSET(sq->sq_signals, signo); 408 return (ret); 409 } 410 411 void 412 sigqueue_flush(sigqueue_t *sq) 413 { 414 struct proc *p = sq->sq_proc; 415 ksiginfo_t *ksi; 416 417 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 418 419 if (p != NULL) 420 PROC_LOCK_ASSERT(p, MA_OWNED); 421 422 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 423 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 424 ksi->ksi_sigq = NULL; 425 if (ksiginfo_tryfree(ksi) && p != NULL) 426 p->p_pendingcnt--; 427 } 428 429 SIGEMPTYSET(sq->sq_signals); 430 SIGEMPTYSET(sq->sq_kill); 431 } 432 433 static void 434 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 435 { 436 sigset_t tmp; 437 struct proc *p1, *p2; 438 ksiginfo_t *ksi, *next; 439 440 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 441 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 442 p1 = src->sq_proc; 443 p2 = dst->sq_proc; 444 /* Move siginfo to target list */ 445 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 446 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 447 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 448 if (p1 != NULL) 449 p1->p_pendingcnt--; 450 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = dst; 452 if (p2 != NULL) 453 p2->p_pendingcnt++; 454 } 455 } 456 457 /* Move pending bits to target list */ 458 tmp = src->sq_kill; 459 SIGSETAND(tmp, *set); 460 SIGSETOR(dst->sq_kill, tmp); 461 SIGSETNAND(src->sq_kill, tmp); 462 463 tmp = src->sq_signals; 464 SIGSETAND(tmp, *set); 465 SIGSETOR(dst->sq_signals, tmp); 466 SIGSETNAND(src->sq_signals, tmp); 467 } 468 469 #if 0 470 static void 471 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 472 { 473 sigset_t set; 474 475 SIGEMPTYSET(set); 476 SIGADDSET(set, signo); 477 sigqueue_move_set(src, dst, &set); 478 } 479 #endif 480 481 static void 482 sigqueue_delete_set(sigqueue_t *sq, const 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 } 501 502 void 503 sigqueue_delete(sigqueue_t *sq, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_delete_set(sq, &set); 510 } 511 512 /* Remove a set of signals for a process */ 513 static void 514 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 515 { 516 sigqueue_t worklist; 517 struct thread *td0; 518 519 PROC_LOCK_ASSERT(p, MA_OWNED); 520 521 sigqueue_init(&worklist, NULL); 522 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 523 524 FOREACH_THREAD_IN_PROC(p, td0) 525 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 526 527 sigqueue_flush(&worklist); 528 } 529 530 void 531 sigqueue_delete_proc(struct proc *p, int signo) 532 { 533 sigset_t set; 534 535 SIGEMPTYSET(set); 536 SIGADDSET(set, signo); 537 sigqueue_delete_set_proc(p, &set); 538 } 539 540 static void 541 sigqueue_delete_stopmask_proc(struct proc *p) 542 { 543 sigset_t set; 544 545 SIGEMPTYSET(set); 546 SIGADDSET(set, SIGSTOP); 547 SIGADDSET(set, SIGTSTP); 548 SIGADDSET(set, SIGTTIN); 549 SIGADDSET(set, SIGTTOU); 550 sigqueue_delete_set_proc(p, &set); 551 } 552 553 /* 554 * Determine signal that should be delivered to process p, the current 555 * process, 0 if none. If there is a pending stop signal with default 556 * action, the process stops in issignal(). 557 */ 558 int 559 cursig(struct thread *td, int stop_allowed) 560 { 561 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 562 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 563 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 564 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 565 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 566 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 567 } 568 569 /* 570 * Arrange for ast() to handle unmasked pending signals on return to user 571 * mode. This must be called whenever a signal is added to td_sigqueue or 572 * unmasked in td_sigmask. 573 */ 574 void 575 signotify(struct thread *td) 576 { 577 struct proc *p; 578 579 p = td->td_proc; 580 581 PROC_LOCK_ASSERT(p, MA_OWNED); 582 583 if (SIGPENDING(td)) { 584 thread_lock(td); 585 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 586 thread_unlock(td); 587 } 588 } 589 590 int 591 sigonstack(size_t sp) 592 { 593 struct thread *td = curthread; 594 595 return ((td->td_pflags & TDP_ALTSTACK) ? 596 #if defined(COMPAT_43) 597 ((td->td_sigstk.ss_size == 0) ? 598 (td->td_sigstk.ss_flags & SS_ONSTACK) : 599 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 600 #else 601 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 602 #endif 603 : 0); 604 } 605 606 static __inline int 607 sigprop(int sig) 608 { 609 610 if (sig > 0 && sig < NSIG) 611 return (sigproptbl[_SIG_IDX(sig)]); 612 return (0); 613 } 614 615 int 616 sig_ffs(sigset_t *set) 617 { 618 int i; 619 620 for (i = 0; i < _SIG_WORDS; i++) 621 if (set->__bits[i]) 622 return (ffs(set->__bits[i]) + (i * 32)); 623 return (0); 624 } 625 626 /* 627 * kern_sigaction 628 * sigaction 629 * freebsd4_sigaction 630 * osigaction 631 */ 632 int 633 kern_sigaction(td, sig, act, oact, flags) 634 struct thread *td; 635 register int sig; 636 struct sigaction *act, *oact; 637 int flags; 638 { 639 struct sigacts *ps; 640 struct proc *p = td->td_proc; 641 642 if (!_SIG_VALID(sig)) 643 return (EINVAL); 644 645 PROC_LOCK(p); 646 ps = p->p_sigacts; 647 mtx_lock(&ps->ps_mtx); 648 if (oact) { 649 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 650 oact->sa_flags = 0; 651 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 652 oact->sa_flags |= SA_ONSTACK; 653 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 654 oact->sa_flags |= SA_RESTART; 655 if (SIGISMEMBER(ps->ps_sigreset, sig)) 656 oact->sa_flags |= SA_RESETHAND; 657 if (SIGISMEMBER(ps->ps_signodefer, sig)) 658 oact->sa_flags |= SA_NODEFER; 659 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 660 oact->sa_flags |= SA_SIGINFO; 661 oact->sa_sigaction = 662 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 663 } else 664 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 665 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 666 oact->sa_flags |= SA_NOCLDSTOP; 667 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 668 oact->sa_flags |= SA_NOCLDWAIT; 669 } 670 if (act) { 671 if ((sig == SIGKILL || sig == SIGSTOP) && 672 act->sa_handler != SIG_DFL) { 673 mtx_unlock(&ps->ps_mtx); 674 PROC_UNLOCK(p); 675 return (EINVAL); 676 } 677 678 /* 679 * Change setting atomically. 680 */ 681 682 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 683 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 684 if (act->sa_flags & SA_SIGINFO) { 685 ps->ps_sigact[_SIG_IDX(sig)] = 686 (__sighandler_t *)act->sa_sigaction; 687 SIGADDSET(ps->ps_siginfo, sig); 688 } else { 689 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 690 SIGDELSET(ps->ps_siginfo, sig); 691 } 692 if (!(act->sa_flags & SA_RESTART)) 693 SIGADDSET(ps->ps_sigintr, sig); 694 else 695 SIGDELSET(ps->ps_sigintr, sig); 696 if (act->sa_flags & SA_ONSTACK) 697 SIGADDSET(ps->ps_sigonstack, sig); 698 else 699 SIGDELSET(ps->ps_sigonstack, sig); 700 if (act->sa_flags & SA_RESETHAND) 701 SIGADDSET(ps->ps_sigreset, sig); 702 else 703 SIGDELSET(ps->ps_sigreset, sig); 704 if (act->sa_flags & SA_NODEFER) 705 SIGADDSET(ps->ps_signodefer, sig); 706 else 707 SIGDELSET(ps->ps_signodefer, sig); 708 if (sig == SIGCHLD) { 709 if (act->sa_flags & SA_NOCLDSTOP) 710 ps->ps_flag |= PS_NOCLDSTOP; 711 else 712 ps->ps_flag &= ~PS_NOCLDSTOP; 713 if (act->sa_flags & SA_NOCLDWAIT) { 714 /* 715 * Paranoia: since SA_NOCLDWAIT is implemented 716 * by reparenting the dying child to PID 1 (and 717 * trust it to reap the zombie), PID 1 itself 718 * is forbidden to set SA_NOCLDWAIT. 719 */ 720 if (p->p_pid == 1) 721 ps->ps_flag &= ~PS_NOCLDWAIT; 722 else 723 ps->ps_flag |= PS_NOCLDWAIT; 724 } else 725 ps->ps_flag &= ~PS_NOCLDWAIT; 726 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 727 ps->ps_flag |= PS_CLDSIGIGN; 728 else 729 ps->ps_flag &= ~PS_CLDSIGIGN; 730 } 731 /* 732 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 733 * and for signals set to SIG_DFL where the default is to 734 * ignore. However, don't put SIGCONT in ps_sigignore, as we 735 * have to restart the process. 736 */ 737 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 738 (sigprop(sig) & SA_IGNORE && 739 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 740 /* never to be seen again */ 741 sigqueue_delete_proc(p, sig); 742 if (sig != SIGCONT) 743 /* easier in psignal */ 744 SIGADDSET(ps->ps_sigignore, sig); 745 SIGDELSET(ps->ps_sigcatch, sig); 746 } else { 747 SIGDELSET(ps->ps_sigignore, sig); 748 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 749 SIGDELSET(ps->ps_sigcatch, sig); 750 else 751 SIGADDSET(ps->ps_sigcatch, sig); 752 } 753 #ifdef COMPAT_FREEBSD4 754 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 755 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 756 (flags & KSA_FREEBSD4) == 0) 757 SIGDELSET(ps->ps_freebsd4, sig); 758 else 759 SIGADDSET(ps->ps_freebsd4, sig); 760 #endif 761 #ifdef COMPAT_43 762 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 763 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 764 (flags & KSA_OSIGSET) == 0) 765 SIGDELSET(ps->ps_osigset, sig); 766 else 767 SIGADDSET(ps->ps_osigset, sig); 768 #endif 769 } 770 mtx_unlock(&ps->ps_mtx); 771 PROC_UNLOCK(p); 772 return (0); 773 } 774 775 #ifndef _SYS_SYSPROTO_H_ 776 struct sigaction_args { 777 int sig; 778 struct sigaction *act; 779 struct sigaction *oact; 780 }; 781 #endif 782 int 783 sigaction(td, uap) 784 struct thread *td; 785 register struct sigaction_args *uap; 786 { 787 struct sigaction act, oact; 788 register struct sigaction *actp, *oactp; 789 int error; 790 791 actp = (uap->act != NULL) ? &act : NULL; 792 oactp = (uap->oact != NULL) ? &oact : NULL; 793 if (actp) { 794 error = copyin(uap->act, actp, sizeof(act)); 795 if (error) 796 return (error); 797 } 798 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 799 if (oactp && !error) 800 error = copyout(oactp, uap->oact, sizeof(oact)); 801 return (error); 802 } 803 804 #ifdef COMPAT_FREEBSD4 805 #ifndef _SYS_SYSPROTO_H_ 806 struct freebsd4_sigaction_args { 807 int sig; 808 struct sigaction *act; 809 struct sigaction *oact; 810 }; 811 #endif 812 int 813 freebsd4_sigaction(td, uap) 814 struct thread *td; 815 register struct freebsd4_sigaction_args *uap; 816 { 817 struct sigaction act, oact; 818 register struct sigaction *actp, *oactp; 819 int error; 820 821 822 actp = (uap->act != NULL) ? &act : NULL; 823 oactp = (uap->oact != NULL) ? &oact : NULL; 824 if (actp) { 825 error = copyin(uap->act, actp, sizeof(act)); 826 if (error) 827 return (error); 828 } 829 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 830 if (oactp && !error) 831 error = copyout(oactp, uap->oact, sizeof(oact)); 832 return (error); 833 } 834 #endif /* COMAPT_FREEBSD4 */ 835 836 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 837 #ifndef _SYS_SYSPROTO_H_ 838 struct osigaction_args { 839 int signum; 840 struct osigaction *nsa; 841 struct osigaction *osa; 842 }; 843 #endif 844 int 845 osigaction(td, uap) 846 struct thread *td; 847 register struct osigaction_args *uap; 848 { 849 struct osigaction sa; 850 struct sigaction nsa, osa; 851 register struct sigaction *nsap, *osap; 852 int error; 853 854 if (uap->signum <= 0 || uap->signum >= ONSIG) 855 return (EINVAL); 856 857 nsap = (uap->nsa != NULL) ? &nsa : NULL; 858 osap = (uap->osa != NULL) ? &osa : NULL; 859 860 if (nsap) { 861 error = copyin(uap->nsa, &sa, sizeof(sa)); 862 if (error) 863 return (error); 864 nsap->sa_handler = sa.sa_handler; 865 nsap->sa_flags = sa.sa_flags; 866 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 867 } 868 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 869 if (osap && !error) { 870 sa.sa_handler = osap->sa_handler; 871 sa.sa_flags = osap->sa_flags; 872 SIG2OSIG(osap->sa_mask, sa.sa_mask); 873 error = copyout(&sa, uap->osa, sizeof(sa)); 874 } 875 return (error); 876 } 877 878 #if !defined(__i386__) 879 /* Avoid replicating the same stub everywhere */ 880 int 881 osigreturn(td, uap) 882 struct thread *td; 883 struct osigreturn_args *uap; 884 { 885 886 return (nosys(td, (struct nosys_args *)uap)); 887 } 888 #endif 889 #endif /* COMPAT_43 */ 890 891 /* 892 * Initialize signal state for process 0; 893 * set to ignore signals that are ignored by default. 894 */ 895 void 896 siginit(p) 897 struct proc *p; 898 { 899 register int i; 900 struct sigacts *ps; 901 902 PROC_LOCK(p); 903 ps = p->p_sigacts; 904 mtx_lock(&ps->ps_mtx); 905 for (i = 1; i <= NSIG; i++) 906 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 907 SIGADDSET(ps->ps_sigignore, i); 908 mtx_unlock(&ps->ps_mtx); 909 PROC_UNLOCK(p); 910 } 911 912 /* 913 * Reset signals for an exec of the specified process. 914 */ 915 void 916 execsigs(struct proc *p) 917 { 918 struct sigacts *ps; 919 int sig; 920 struct thread *td; 921 922 /* 923 * Reset caught signals. Held signals remain held 924 * through td_sigmask (unless they were caught, 925 * and are now ignored by default). 926 */ 927 PROC_LOCK_ASSERT(p, MA_OWNED); 928 td = FIRST_THREAD_IN_PROC(p); 929 ps = p->p_sigacts; 930 mtx_lock(&ps->ps_mtx); 931 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 932 sig = sig_ffs(&ps->ps_sigcatch); 933 SIGDELSET(ps->ps_sigcatch, sig); 934 if (sigprop(sig) & SA_IGNORE) { 935 if (sig != SIGCONT) 936 SIGADDSET(ps->ps_sigignore, sig); 937 sigqueue_delete_proc(p, sig); 938 } 939 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 940 } 941 /* 942 * Reset stack state to the user stack. 943 * Clear set of signals caught on the signal stack. 944 */ 945 td->td_sigstk.ss_flags = SS_DISABLE; 946 td->td_sigstk.ss_size = 0; 947 td->td_sigstk.ss_sp = 0; 948 td->td_pflags &= ~TDP_ALTSTACK; 949 /* 950 * Reset no zombies if child dies flag as Solaris does. 951 */ 952 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 953 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 954 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 955 mtx_unlock(&ps->ps_mtx); 956 } 957 958 /* 959 * kern_sigprocmask() 960 * 961 * Manipulate signal mask. 962 */ 963 int 964 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 965 int flags) 966 { 967 sigset_t new_block, oset1; 968 struct proc *p; 969 int error; 970 971 p = td->td_proc; 972 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 973 PROC_LOCK(p); 974 if (oset != NULL) 975 *oset = td->td_sigmask; 976 977 error = 0; 978 if (set != NULL) { 979 switch (how) { 980 case SIG_BLOCK: 981 SIG_CANTMASK(*set); 982 oset1 = td->td_sigmask; 983 SIGSETOR(td->td_sigmask, *set); 984 new_block = td->td_sigmask; 985 SIGSETNAND(new_block, oset1); 986 break; 987 case SIG_UNBLOCK: 988 SIGSETNAND(td->td_sigmask, *set); 989 signotify(td); 990 goto out; 991 case SIG_SETMASK: 992 SIG_CANTMASK(*set); 993 oset1 = td->td_sigmask; 994 if (flags & SIGPROCMASK_OLD) 995 SIGSETLO(td->td_sigmask, *set); 996 else 997 td->td_sigmask = *set; 998 new_block = td->td_sigmask; 999 SIGSETNAND(new_block, oset1); 1000 signotify(td); 1001 break; 1002 default: 1003 error = EINVAL; 1004 goto out; 1005 } 1006 1007 /* 1008 * The new_block set contains signals that were not previously 1009 * blocked, but are blocked now. 1010 * 1011 * In case we block any signal that was not previously blocked 1012 * for td, and process has the signal pending, try to schedule 1013 * signal delivery to some thread that does not block the 1014 * signal, possibly waking it up. 1015 */ 1016 if (p->p_numthreads != 1) 1017 reschedule_signals(p, new_block, flags); 1018 } 1019 1020 out: 1021 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1022 PROC_UNLOCK(p); 1023 return (error); 1024 } 1025 1026 #ifndef _SYS_SYSPROTO_H_ 1027 struct sigprocmask_args { 1028 int how; 1029 const sigset_t *set; 1030 sigset_t *oset; 1031 }; 1032 #endif 1033 int 1034 sigprocmask(td, uap) 1035 register struct thread *td; 1036 struct sigprocmask_args *uap; 1037 { 1038 sigset_t set, oset; 1039 sigset_t *setp, *osetp; 1040 int error; 1041 1042 setp = (uap->set != NULL) ? &set : NULL; 1043 osetp = (uap->oset != NULL) ? &oset : NULL; 1044 if (setp) { 1045 error = copyin(uap->set, setp, sizeof(set)); 1046 if (error) 1047 return (error); 1048 } 1049 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1050 if (osetp && !error) { 1051 error = copyout(osetp, uap->oset, sizeof(oset)); 1052 } 1053 return (error); 1054 } 1055 1056 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1057 #ifndef _SYS_SYSPROTO_H_ 1058 struct osigprocmask_args { 1059 int how; 1060 osigset_t mask; 1061 }; 1062 #endif 1063 int 1064 osigprocmask(td, uap) 1065 register struct thread *td; 1066 struct osigprocmask_args *uap; 1067 { 1068 sigset_t set, oset; 1069 int error; 1070 1071 OSIG2SIG(uap->mask, set); 1072 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1073 SIG2OSIG(oset, td->td_retval[0]); 1074 return (error); 1075 } 1076 #endif /* COMPAT_43 */ 1077 1078 int 1079 sigwait(struct thread *td, struct sigwait_args *uap) 1080 { 1081 ksiginfo_t ksi; 1082 sigset_t set; 1083 int error; 1084 1085 error = copyin(uap->set, &set, sizeof(set)); 1086 if (error) { 1087 td->td_retval[0] = error; 1088 return (0); 1089 } 1090 1091 error = kern_sigtimedwait(td, set, &ksi, NULL); 1092 if (error) { 1093 if (error == ERESTART) 1094 return (error); 1095 td->td_retval[0] = error; 1096 return (0); 1097 } 1098 1099 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1100 td->td_retval[0] = error; 1101 return (0); 1102 } 1103 1104 int 1105 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1106 { 1107 struct timespec ts; 1108 struct timespec *timeout; 1109 sigset_t set; 1110 ksiginfo_t ksi; 1111 int error; 1112 1113 if (uap->timeout) { 1114 error = copyin(uap->timeout, &ts, sizeof(ts)); 1115 if (error) 1116 return (error); 1117 1118 timeout = &ts; 1119 } else 1120 timeout = NULL; 1121 1122 error = copyin(uap->set, &set, sizeof(set)); 1123 if (error) 1124 return (error); 1125 1126 error = kern_sigtimedwait(td, set, &ksi, timeout); 1127 if (error) 1128 return (error); 1129 1130 if (uap->info) 1131 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1132 1133 if (error == 0) 1134 td->td_retval[0] = ksi.ksi_signo; 1135 return (error); 1136 } 1137 1138 int 1139 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1140 { 1141 ksiginfo_t ksi; 1142 sigset_t set; 1143 int error; 1144 1145 error = copyin(uap->set, &set, sizeof(set)); 1146 if (error) 1147 return (error); 1148 1149 error = kern_sigtimedwait(td, set, &ksi, NULL); 1150 if (error) 1151 return (error); 1152 1153 if (uap->info) 1154 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1155 1156 if (error == 0) 1157 td->td_retval[0] = ksi.ksi_signo; 1158 return (error); 1159 } 1160 1161 int 1162 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1163 struct timespec *timeout) 1164 { 1165 struct sigacts *ps; 1166 sigset_t saved_mask, new_block; 1167 struct proc *p; 1168 int error, sig, timo, timevalid = 0; 1169 struct timespec rts, ets, ts; 1170 struct timeval tv; 1171 1172 p = td->td_proc; 1173 error = 0; 1174 ets.tv_sec = 0; 1175 ets.tv_nsec = 0; 1176 1177 if (timeout != NULL) { 1178 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1179 timevalid = 1; 1180 getnanouptime(&rts); 1181 ets = rts; 1182 timespecadd(&ets, timeout); 1183 } 1184 } 1185 ksiginfo_init(ksi); 1186 /* Some signals can not be waited for. */ 1187 SIG_CANTMASK(waitset); 1188 ps = p->p_sigacts; 1189 PROC_LOCK(p); 1190 saved_mask = td->td_sigmask; 1191 SIGSETNAND(td->td_sigmask, waitset); 1192 for (;;) { 1193 mtx_lock(&ps->ps_mtx); 1194 sig = cursig(td, SIG_STOP_ALLOWED); 1195 mtx_unlock(&ps->ps_mtx); 1196 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1197 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1198 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1199 error = 0; 1200 break; 1201 } 1202 } 1203 1204 if (error != 0) 1205 break; 1206 1207 /* 1208 * POSIX says this must be checked after looking for pending 1209 * signals. 1210 */ 1211 if (timeout != NULL) { 1212 if (!timevalid) { 1213 error = EINVAL; 1214 break; 1215 } 1216 getnanouptime(&rts); 1217 if (timespeccmp(&rts, &ets, >=)) { 1218 error = EAGAIN; 1219 break; 1220 } 1221 ts = ets; 1222 timespecsub(&ts, &rts); 1223 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1224 timo = tvtohz(&tv); 1225 } else { 1226 timo = 0; 1227 } 1228 1229 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1230 1231 if (timeout != NULL) { 1232 if (error == ERESTART) { 1233 /* Timeout can not be restarted. */ 1234 error = EINTR; 1235 } else if (error == EAGAIN) { 1236 /* We will calculate timeout by ourself. */ 1237 error = 0; 1238 } 1239 } 1240 } 1241 1242 new_block = saved_mask; 1243 SIGSETNAND(new_block, td->td_sigmask); 1244 td->td_sigmask = saved_mask; 1245 /* 1246 * Fewer signals can be delivered to us, reschedule signal 1247 * notification. 1248 */ 1249 if (p->p_numthreads != 1) 1250 reschedule_signals(p, new_block, 0); 1251 1252 if (error == 0) { 1253 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1254 1255 if (ksi->ksi_code == SI_TIMER) 1256 itimer_accept(p, ksi->ksi_timerid, ksi); 1257 1258 #ifdef KTRACE 1259 if (KTRPOINT(td, KTR_PSIG)) { 1260 sig_t action; 1261 1262 mtx_lock(&ps->ps_mtx); 1263 action = ps->ps_sigact[_SIG_IDX(sig)]; 1264 mtx_unlock(&ps->ps_mtx); 1265 ktrpsig(sig, action, &td->td_sigmask, 0); 1266 } 1267 #endif 1268 if (sig == SIGKILL) 1269 sigexit(td, sig); 1270 } 1271 PROC_UNLOCK(p); 1272 return (error); 1273 } 1274 1275 #ifndef _SYS_SYSPROTO_H_ 1276 struct sigpending_args { 1277 sigset_t *set; 1278 }; 1279 #endif 1280 int 1281 sigpending(td, uap) 1282 struct thread *td; 1283 struct sigpending_args *uap; 1284 { 1285 struct proc *p = td->td_proc; 1286 sigset_t pending; 1287 1288 PROC_LOCK(p); 1289 pending = p->p_sigqueue.sq_signals; 1290 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1291 PROC_UNLOCK(p); 1292 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1293 } 1294 1295 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1296 #ifndef _SYS_SYSPROTO_H_ 1297 struct osigpending_args { 1298 int dummy; 1299 }; 1300 #endif 1301 int 1302 osigpending(td, uap) 1303 struct thread *td; 1304 struct osigpending_args *uap; 1305 { 1306 struct proc *p = td->td_proc; 1307 sigset_t pending; 1308 1309 PROC_LOCK(p); 1310 pending = p->p_sigqueue.sq_signals; 1311 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1312 PROC_UNLOCK(p); 1313 SIG2OSIG(pending, td->td_retval[0]); 1314 return (0); 1315 } 1316 #endif /* COMPAT_43 */ 1317 1318 #if defined(COMPAT_43) 1319 /* 1320 * Generalized interface signal handler, 4.3-compatible. 1321 */ 1322 #ifndef _SYS_SYSPROTO_H_ 1323 struct osigvec_args { 1324 int signum; 1325 struct sigvec *nsv; 1326 struct sigvec *osv; 1327 }; 1328 #endif 1329 /* ARGSUSED */ 1330 int 1331 osigvec(td, uap) 1332 struct thread *td; 1333 register struct osigvec_args *uap; 1334 { 1335 struct sigvec vec; 1336 struct sigaction nsa, osa; 1337 register struct sigaction *nsap, *osap; 1338 int error; 1339 1340 if (uap->signum <= 0 || uap->signum >= ONSIG) 1341 return (EINVAL); 1342 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1343 osap = (uap->osv != NULL) ? &osa : NULL; 1344 if (nsap) { 1345 error = copyin(uap->nsv, &vec, sizeof(vec)); 1346 if (error) 1347 return (error); 1348 nsap->sa_handler = vec.sv_handler; 1349 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1350 nsap->sa_flags = vec.sv_flags; 1351 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1352 } 1353 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1354 if (osap && !error) { 1355 vec.sv_handler = osap->sa_handler; 1356 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1357 vec.sv_flags = osap->sa_flags; 1358 vec.sv_flags &= ~SA_NOCLDWAIT; 1359 vec.sv_flags ^= SA_RESTART; 1360 error = copyout(&vec, uap->osv, sizeof(vec)); 1361 } 1362 return (error); 1363 } 1364 1365 #ifndef _SYS_SYSPROTO_H_ 1366 struct osigblock_args { 1367 int mask; 1368 }; 1369 #endif 1370 int 1371 osigblock(td, uap) 1372 register struct thread *td; 1373 struct osigblock_args *uap; 1374 { 1375 sigset_t set, oset; 1376 1377 OSIG2SIG(uap->mask, set); 1378 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1379 SIG2OSIG(oset, td->td_retval[0]); 1380 return (0); 1381 } 1382 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigsetmask_args { 1385 int mask; 1386 }; 1387 #endif 1388 int 1389 osigsetmask(td, uap) 1390 struct thread *td; 1391 struct osigsetmask_args *uap; 1392 { 1393 sigset_t set, oset; 1394 1395 OSIG2SIG(uap->mask, set); 1396 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1397 SIG2OSIG(oset, td->td_retval[0]); 1398 return (0); 1399 } 1400 #endif /* COMPAT_43 */ 1401 1402 /* 1403 * Suspend calling thread until signal, providing mask to be set in the 1404 * meantime. 1405 */ 1406 #ifndef _SYS_SYSPROTO_H_ 1407 struct sigsuspend_args { 1408 const sigset_t *sigmask; 1409 }; 1410 #endif 1411 /* ARGSUSED */ 1412 int 1413 sigsuspend(td, uap) 1414 struct thread *td; 1415 struct sigsuspend_args *uap; 1416 { 1417 sigset_t mask; 1418 int error; 1419 1420 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1421 if (error) 1422 return (error); 1423 return (kern_sigsuspend(td, mask)); 1424 } 1425 1426 int 1427 kern_sigsuspend(struct thread *td, sigset_t mask) 1428 { 1429 struct proc *p = td->td_proc; 1430 int has_sig, sig; 1431 1432 /* 1433 * When returning from sigsuspend, we want 1434 * the old mask to be restored after the 1435 * signal handler has finished. Thus, we 1436 * save it here and mark the sigacts structure 1437 * to indicate this. 1438 */ 1439 PROC_LOCK(p); 1440 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1441 SIGPROCMASK_PROC_LOCKED); 1442 td->td_pflags |= TDP_OLDMASK; 1443 1444 /* 1445 * Process signals now. Otherwise, we can get spurious wakeup 1446 * due to signal entered process queue, but delivered to other 1447 * thread. But sigsuspend should return only on signal 1448 * delivery. 1449 */ 1450 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1451 for (has_sig = 0; !has_sig;) { 1452 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1453 0) == 0) 1454 /* void */; 1455 thread_suspend_check(0); 1456 mtx_lock(&p->p_sigacts->ps_mtx); 1457 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1458 has_sig += postsig(sig); 1459 mtx_unlock(&p->p_sigacts->ps_mtx); 1460 } 1461 PROC_UNLOCK(p); 1462 return (EJUSTRETURN); 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 sigset_t mask; 1482 1483 OSIG2SIG(uap->mask, mask); 1484 return (kern_sigsuspend(td, mask)); 1485 } 1486 #endif /* COMPAT_43 */ 1487 1488 #if defined(COMPAT_43) 1489 #ifndef _SYS_SYSPROTO_H_ 1490 struct osigstack_args { 1491 struct sigstack *nss; 1492 struct sigstack *oss; 1493 }; 1494 #endif 1495 /* ARGSUSED */ 1496 int 1497 osigstack(td, uap) 1498 struct thread *td; 1499 register struct osigstack_args *uap; 1500 { 1501 struct sigstack nss, oss; 1502 int error = 0; 1503 1504 if (uap->nss != NULL) { 1505 error = copyin(uap->nss, &nss, sizeof(nss)); 1506 if (error) 1507 return (error); 1508 } 1509 oss.ss_sp = td->td_sigstk.ss_sp; 1510 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1511 if (uap->nss != NULL) { 1512 td->td_sigstk.ss_sp = nss.ss_sp; 1513 td->td_sigstk.ss_size = 0; 1514 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1515 td->td_pflags |= TDP_ALTSTACK; 1516 } 1517 if (uap->oss != NULL) 1518 error = copyout(&oss, uap->oss, sizeof(oss)); 1519 1520 return (error); 1521 } 1522 #endif /* COMPAT_43 */ 1523 1524 #ifndef _SYS_SYSPROTO_H_ 1525 struct sigaltstack_args { 1526 stack_t *ss; 1527 stack_t *oss; 1528 }; 1529 #endif 1530 /* ARGSUSED */ 1531 int 1532 sigaltstack(td, uap) 1533 struct thread *td; 1534 register struct sigaltstack_args *uap; 1535 { 1536 stack_t ss, oss; 1537 int error; 1538 1539 if (uap->ss != NULL) { 1540 error = copyin(uap->ss, &ss, sizeof(ss)); 1541 if (error) 1542 return (error); 1543 } 1544 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1545 (uap->oss != NULL) ? &oss : NULL); 1546 if (error) 1547 return (error); 1548 if (uap->oss != NULL) 1549 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1550 return (error); 1551 } 1552 1553 int 1554 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1555 { 1556 struct proc *p = td->td_proc; 1557 int oonstack; 1558 1559 oonstack = sigonstack(cpu_getstack(td)); 1560 1561 if (oss != NULL) { 1562 *oss = td->td_sigstk; 1563 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1564 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1565 } 1566 1567 if (ss != NULL) { 1568 if (oonstack) 1569 return (EPERM); 1570 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1571 return (EINVAL); 1572 if (!(ss->ss_flags & SS_DISABLE)) { 1573 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1574 return (ENOMEM); 1575 1576 td->td_sigstk = *ss; 1577 td->td_pflags |= TDP_ALTSTACK; 1578 } else { 1579 td->td_pflags &= ~TDP_ALTSTACK; 1580 } 1581 } 1582 return (0); 1583 } 1584 1585 /* 1586 * Common code for kill process group/broadcast kill. 1587 * cp is calling process. 1588 */ 1589 static int 1590 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1591 { 1592 struct proc *p; 1593 struct pgrp *pgrp; 1594 int nfound = 0; 1595 1596 if (all) { 1597 /* 1598 * broadcast 1599 */ 1600 sx_slock(&allproc_lock); 1601 FOREACH_PROC_IN_SYSTEM(p) { 1602 PROC_LOCK(p); 1603 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1604 p == td->td_proc || p->p_state == PRS_NEW) { 1605 PROC_UNLOCK(p); 1606 continue; 1607 } 1608 if (p_cansignal(td, p, sig) == 0) { 1609 nfound++; 1610 if (sig) 1611 pksignal(p, sig, ksi); 1612 } 1613 PROC_UNLOCK(p); 1614 } 1615 sx_sunlock(&allproc_lock); 1616 } else { 1617 sx_slock(&proctree_lock); 1618 if (pgid == 0) { 1619 /* 1620 * zero pgid means send to my process group. 1621 */ 1622 pgrp = td->td_proc->p_pgrp; 1623 PGRP_LOCK(pgrp); 1624 } else { 1625 pgrp = pgfind(pgid); 1626 if (pgrp == NULL) { 1627 sx_sunlock(&proctree_lock); 1628 return (ESRCH); 1629 } 1630 } 1631 sx_sunlock(&proctree_lock); 1632 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1633 PROC_LOCK(p); 1634 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1635 p->p_state == PRS_NEW ) { 1636 PROC_UNLOCK(p); 1637 continue; 1638 } 1639 if (p_cansignal(td, p, sig) == 0) { 1640 nfound++; 1641 if (sig) 1642 pksignal(p, sig, ksi); 1643 } 1644 PROC_UNLOCK(p); 1645 } 1646 PGRP_UNLOCK(pgrp); 1647 } 1648 return (nfound ? 0 : ESRCH); 1649 } 1650 1651 #ifndef _SYS_SYSPROTO_H_ 1652 struct kill_args { 1653 int pid; 1654 int signum; 1655 }; 1656 #endif 1657 /* ARGSUSED */ 1658 int 1659 kill(struct thread *td, struct kill_args *uap) 1660 { 1661 ksiginfo_t ksi; 1662 struct proc *p; 1663 int error; 1664 1665 AUDIT_ARG_SIGNUM(uap->signum); 1666 AUDIT_ARG_PID(uap->pid); 1667 if ((u_int)uap->signum > _SIG_MAXSIG) 1668 return (EINVAL); 1669 1670 ksiginfo_init(&ksi); 1671 ksi.ksi_signo = uap->signum; 1672 ksi.ksi_code = SI_USER; 1673 ksi.ksi_pid = td->td_proc->p_pid; 1674 ksi.ksi_uid = td->td_ucred->cr_ruid; 1675 1676 if (uap->pid > 0) { 1677 /* kill single process */ 1678 if ((p = pfind(uap->pid)) == NULL) { 1679 if ((p = zpfind(uap->pid)) == NULL) 1680 return (ESRCH); 1681 } 1682 AUDIT_ARG_PROCESS(p); 1683 error = p_cansignal(td, p, uap->signum); 1684 if (error == 0 && uap->signum) 1685 pksignal(p, uap->signum, &ksi); 1686 PROC_UNLOCK(p); 1687 return (error); 1688 } 1689 switch (uap->pid) { 1690 case -1: /* broadcast signal */ 1691 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1692 case 0: /* signal own process group */ 1693 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1694 default: /* negative explicit process group */ 1695 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1696 } 1697 /* NOTREACHED */ 1698 } 1699 1700 #if defined(COMPAT_43) 1701 #ifndef _SYS_SYSPROTO_H_ 1702 struct okillpg_args { 1703 int pgid; 1704 int signum; 1705 }; 1706 #endif 1707 /* ARGSUSED */ 1708 int 1709 okillpg(struct thread *td, struct okillpg_args *uap) 1710 { 1711 ksiginfo_t ksi; 1712 1713 AUDIT_ARG_SIGNUM(uap->signum); 1714 AUDIT_ARG_PID(uap->pgid); 1715 if ((u_int)uap->signum > _SIG_MAXSIG) 1716 return (EINVAL); 1717 1718 ksiginfo_init(&ksi); 1719 ksi.ksi_signo = uap->signum; 1720 ksi.ksi_code = SI_USER; 1721 ksi.ksi_pid = td->td_proc->p_pid; 1722 ksi.ksi_uid = td->td_ucred->cr_ruid; 1723 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1724 } 1725 #endif /* COMPAT_43 */ 1726 1727 #ifndef _SYS_SYSPROTO_H_ 1728 struct sigqueue_args { 1729 pid_t pid; 1730 int signum; 1731 /* union sigval */ void *value; 1732 }; 1733 #endif 1734 int 1735 sigqueue(struct thread *td, struct sigqueue_args *uap) 1736 { 1737 ksiginfo_t ksi; 1738 struct proc *p; 1739 int error; 1740 1741 if ((u_int)uap->signum > _SIG_MAXSIG) 1742 return (EINVAL); 1743 1744 /* 1745 * Specification says sigqueue can only send signal to 1746 * single process. 1747 */ 1748 if (uap->pid <= 0) 1749 return (EINVAL); 1750 1751 if ((p = pfind(uap->pid)) == NULL) { 1752 if ((p = zpfind(uap->pid)) == NULL) 1753 return (ESRCH); 1754 } 1755 error = p_cansignal(td, p, uap->signum); 1756 if (error == 0 && uap->signum != 0) { 1757 ksiginfo_init(&ksi); 1758 ksi.ksi_flags = KSI_SIGQ; 1759 ksi.ksi_signo = uap->signum; 1760 ksi.ksi_code = SI_QUEUE; 1761 ksi.ksi_pid = td->td_proc->p_pid; 1762 ksi.ksi_uid = td->td_ucred->cr_ruid; 1763 ksi.ksi_value.sival_ptr = uap->value; 1764 error = pksignal(p, ksi.ksi_signo, &ksi); 1765 } 1766 PROC_UNLOCK(p); 1767 return (error); 1768 } 1769 1770 /* 1771 * Send a signal to a process group. 1772 */ 1773 void 1774 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1775 { 1776 struct pgrp *pgrp; 1777 1778 if (pgid != 0) { 1779 sx_slock(&proctree_lock); 1780 pgrp = pgfind(pgid); 1781 sx_sunlock(&proctree_lock); 1782 if (pgrp != NULL) { 1783 pgsignal(pgrp, sig, 0, ksi); 1784 PGRP_UNLOCK(pgrp); 1785 } 1786 } 1787 } 1788 1789 /* 1790 * Send a signal to a process group. If checktty is 1, 1791 * limit to members which have a controlling terminal. 1792 */ 1793 void 1794 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1795 { 1796 struct proc *p; 1797 1798 if (pgrp) { 1799 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1800 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1801 PROC_LOCK(p); 1802 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1803 pksignal(p, sig, ksi); 1804 PROC_UNLOCK(p); 1805 } 1806 } 1807 } 1808 1809 /* 1810 * Send a signal caused by a trap to the current thread. If it will be 1811 * caught immediately, deliver it with correct code. Otherwise, post it 1812 * normally. 1813 */ 1814 void 1815 trapsignal(struct thread *td, ksiginfo_t *ksi) 1816 { 1817 struct sigacts *ps; 1818 sigset_t mask; 1819 struct proc *p; 1820 int sig; 1821 int code; 1822 1823 p = td->td_proc; 1824 sig = ksi->ksi_signo; 1825 code = ksi->ksi_code; 1826 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1827 1828 PROC_LOCK(p); 1829 ps = p->p_sigacts; 1830 mtx_lock(&ps->ps_mtx); 1831 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1832 !SIGISMEMBER(td->td_sigmask, sig)) { 1833 td->td_ru.ru_nsignals++; 1834 #ifdef KTRACE 1835 if (KTRPOINT(curthread, KTR_PSIG)) 1836 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1837 &td->td_sigmask, code); 1838 #endif 1839 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1840 ksi, &td->td_sigmask); 1841 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1842 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1843 SIGADDSET(mask, sig); 1844 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1845 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1846 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1847 /* 1848 * See kern_sigaction() for origin of this code. 1849 */ 1850 SIGDELSET(ps->ps_sigcatch, sig); 1851 if (sig != SIGCONT && 1852 sigprop(sig) & SA_IGNORE) 1853 SIGADDSET(ps->ps_sigignore, sig); 1854 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1855 } 1856 mtx_unlock(&ps->ps_mtx); 1857 } else { 1858 /* 1859 * Avoid a possible infinite loop if the thread 1860 * masking the signal or process is ignoring the 1861 * signal. 1862 */ 1863 if (kern_forcesigexit && 1864 (SIGISMEMBER(td->td_sigmask, sig) || 1865 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1866 SIGDELSET(td->td_sigmask, sig); 1867 SIGDELSET(ps->ps_sigcatch, sig); 1868 SIGDELSET(ps->ps_sigignore, sig); 1869 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1870 } 1871 mtx_unlock(&ps->ps_mtx); 1872 p->p_code = code; /* XXX for core dump/debugger */ 1873 p->p_sig = sig; /* XXX to verify code */ 1874 tdsendsignal(p, td, sig, ksi); 1875 } 1876 PROC_UNLOCK(p); 1877 } 1878 1879 static struct thread * 1880 sigtd(struct proc *p, int sig, int prop) 1881 { 1882 struct thread *td, *signal_td; 1883 1884 PROC_LOCK_ASSERT(p, MA_OWNED); 1885 1886 /* 1887 * Check if current thread can handle the signal without 1888 * switching context to another thread. 1889 */ 1890 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1891 return (curthread); 1892 signal_td = NULL; 1893 FOREACH_THREAD_IN_PROC(p, td) { 1894 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1895 signal_td = td; 1896 break; 1897 } 1898 } 1899 if (signal_td == NULL) 1900 signal_td = FIRST_THREAD_IN_PROC(p); 1901 return (signal_td); 1902 } 1903 1904 /* 1905 * Send the signal to the process. If the signal has an action, the action 1906 * is usually performed by the target process rather than the caller; we add 1907 * the signal to the set of pending signals for the process. 1908 * 1909 * Exceptions: 1910 * o When a stop signal is sent to a sleeping process that takes the 1911 * default action, the process is stopped without awakening it. 1912 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1913 * regardless of the signal action (eg, blocked or ignored). 1914 * 1915 * Other ignored signals are discarded immediately. 1916 * 1917 * NB: This function may be entered from the debugger via the "kill" DDB 1918 * command. There is little that can be done to mitigate the possibly messy 1919 * side effects of this unwise possibility. 1920 */ 1921 void 1922 psignal(struct proc *p, int sig) 1923 { 1924 ksiginfo_t ksi; 1925 1926 ksiginfo_init(&ksi); 1927 ksi.ksi_signo = sig; 1928 ksi.ksi_code = SI_KERNEL; 1929 (void) tdsendsignal(p, NULL, sig, &ksi); 1930 } 1931 1932 int 1933 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1934 { 1935 1936 return (tdsendsignal(p, NULL, sig, ksi)); 1937 } 1938 1939 /* Utility function for finding a thread to send signal event to. */ 1940 int 1941 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1942 { 1943 struct thread *td; 1944 1945 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1946 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 1947 if (td == NULL) 1948 return (ESRCH); 1949 *ttd = td; 1950 } else { 1951 *ttd = NULL; 1952 PROC_LOCK(p); 1953 } 1954 return (0); 1955 } 1956 1957 void 1958 tdsignal(struct thread *td, int sig) 1959 { 1960 ksiginfo_t ksi; 1961 1962 ksiginfo_init(&ksi); 1963 ksi.ksi_signo = sig; 1964 ksi.ksi_code = SI_KERNEL; 1965 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 1966 } 1967 1968 void 1969 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 1970 { 1971 1972 (void) tdsendsignal(td->td_proc, td, sig, ksi); 1973 } 1974 1975 int 1976 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 1977 { 1978 sig_t action; 1979 sigqueue_t *sigqueue; 1980 int prop; 1981 struct sigacts *ps; 1982 int intrval; 1983 int ret = 0; 1984 int wakeup_swapper; 1985 1986 MPASS(td == NULL || p == td->td_proc); 1987 PROC_LOCK_ASSERT(p, MA_OWNED); 1988 1989 if (!_SIG_VALID(sig)) 1990 panic("%s(): invalid signal %d", __func__, sig); 1991 1992 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 1993 1994 /* 1995 * IEEE Std 1003.1-2001: return success when killing a zombie. 1996 */ 1997 if (p->p_state == PRS_ZOMBIE) { 1998 if (ksi && (ksi->ksi_flags & KSI_INS)) 1999 ksiginfo_tryfree(ksi); 2000 return (ret); 2001 } 2002 2003 ps = p->p_sigacts; 2004 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2005 prop = sigprop(sig); 2006 2007 if (td == NULL) { 2008 td = sigtd(p, sig, prop); 2009 sigqueue = &p->p_sigqueue; 2010 } else { 2011 KASSERT(td->td_proc == p, ("invalid thread")); 2012 sigqueue = &td->td_sigqueue; 2013 } 2014 2015 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2016 2017 /* 2018 * If the signal is being ignored, 2019 * then we forget about it immediately. 2020 * (Note: we don't set SIGCONT in ps_sigignore, 2021 * and if it is set to SIG_IGN, 2022 * action will be SIG_DFL here.) 2023 */ 2024 mtx_lock(&ps->ps_mtx); 2025 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2026 SDT_PROBE(proc, kernel, , signal_discard, ps, td, sig, 0, 0 ); 2027 2028 mtx_unlock(&ps->ps_mtx); 2029 if (ksi && (ksi->ksi_flags & KSI_INS)) 2030 ksiginfo_tryfree(ksi); 2031 return (ret); 2032 } 2033 if (SIGISMEMBER(td->td_sigmask, sig)) 2034 action = SIG_HOLD; 2035 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2036 action = SIG_CATCH; 2037 else 2038 action = SIG_DFL; 2039 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2040 intrval = EINTR; 2041 else 2042 intrval = ERESTART; 2043 mtx_unlock(&ps->ps_mtx); 2044 2045 if (prop & SA_CONT) 2046 sigqueue_delete_stopmask_proc(p); 2047 else if (prop & SA_STOP) { 2048 /* 2049 * If sending a tty stop signal to a member of an orphaned 2050 * process group, discard the signal here if the action 2051 * is default; don't stop the process below if sleeping, 2052 * and don't clear any pending SIGCONT. 2053 */ 2054 if ((prop & SA_TTYSTOP) && 2055 (p->p_pgrp->pg_jobc == 0) && 2056 (action == SIG_DFL)) { 2057 if (ksi && (ksi->ksi_flags & KSI_INS)) 2058 ksiginfo_tryfree(ksi); 2059 return (ret); 2060 } 2061 sigqueue_delete_proc(p, SIGCONT); 2062 if (p->p_flag & P_CONTINUED) { 2063 p->p_flag &= ~P_CONTINUED; 2064 PROC_LOCK(p->p_pptr); 2065 sigqueue_take(p->p_ksi); 2066 PROC_UNLOCK(p->p_pptr); 2067 } 2068 } 2069 2070 ret = sigqueue_add(sigqueue, sig, ksi); 2071 if (ret != 0) 2072 return (ret); 2073 signotify(td); 2074 /* 2075 * Defer further processing for signals which are held, 2076 * except that stopped processes must be continued by SIGCONT. 2077 */ 2078 if (action == SIG_HOLD && 2079 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2080 return (ret); 2081 /* 2082 * SIGKILL: Remove procfs STOPEVENTs. 2083 */ 2084 if (sig == SIGKILL) { 2085 /* from procfs_ioctl.c: PIOCBIC */ 2086 p->p_stops = 0; 2087 /* from procfs_ioctl.c: PIOCCONT */ 2088 p->p_step = 0; 2089 wakeup(&p->p_step); 2090 } 2091 /* 2092 * Some signals have a process-wide effect and a per-thread 2093 * component. Most processing occurs when the process next 2094 * tries to cross the user boundary, however there are some 2095 * times when processing needs to be done immediatly, such as 2096 * waking up threads so that they can cross the user boundary. 2097 * We try do the per-process part here. 2098 */ 2099 if (P_SHOULDSTOP(p)) { 2100 if (sig == SIGKILL) { 2101 /* 2102 * If traced process is already stopped, 2103 * then no further action is necessary. 2104 */ 2105 if (p->p_flag & P_TRACED) 2106 goto out; 2107 /* 2108 * SIGKILL sets process running. 2109 * It will die elsewhere. 2110 * All threads must be restarted. 2111 */ 2112 p->p_flag &= ~P_STOPPED_SIG; 2113 goto runfast; 2114 } 2115 2116 if (prop & SA_CONT) { 2117 /* 2118 * If traced process is already stopped, 2119 * then no further action is necessary. 2120 */ 2121 if (p->p_flag & P_TRACED) 2122 goto out; 2123 /* 2124 * If SIGCONT is default (or ignored), we continue the 2125 * process but don't leave the signal in sigqueue as 2126 * it has no further action. If SIGCONT is held, we 2127 * continue the process and leave the signal in 2128 * sigqueue. If the process catches SIGCONT, let it 2129 * handle the signal itself. If it isn't waiting on 2130 * an event, it goes back to run state. 2131 * Otherwise, process goes back to sleep state. 2132 */ 2133 p->p_flag &= ~P_STOPPED_SIG; 2134 PROC_SLOCK(p); 2135 if (p->p_numthreads == p->p_suspcount) { 2136 PROC_SUNLOCK(p); 2137 p->p_flag |= P_CONTINUED; 2138 p->p_xstat = SIGCONT; 2139 PROC_LOCK(p->p_pptr); 2140 childproc_continued(p); 2141 PROC_UNLOCK(p->p_pptr); 2142 PROC_SLOCK(p); 2143 } 2144 if (action == SIG_DFL) { 2145 thread_unsuspend(p); 2146 PROC_SUNLOCK(p); 2147 sigqueue_delete(sigqueue, sig); 2148 goto out; 2149 } 2150 if (action == SIG_CATCH) { 2151 /* 2152 * The process wants to catch it so it needs 2153 * to run at least one thread, but which one? 2154 */ 2155 PROC_SUNLOCK(p); 2156 goto runfast; 2157 } 2158 /* 2159 * The signal is not ignored or caught. 2160 */ 2161 thread_unsuspend(p); 2162 PROC_SUNLOCK(p); 2163 goto out; 2164 } 2165 2166 if (prop & SA_STOP) { 2167 /* 2168 * If traced process is already stopped, 2169 * then no further action is necessary. 2170 */ 2171 if (p->p_flag & P_TRACED) 2172 goto out; 2173 /* 2174 * Already stopped, don't need to stop again 2175 * (If we did the shell could get confused). 2176 * Just make sure the signal STOP bit set. 2177 */ 2178 p->p_flag |= P_STOPPED_SIG; 2179 sigqueue_delete(sigqueue, sig); 2180 goto out; 2181 } 2182 2183 /* 2184 * All other kinds of signals: 2185 * If a thread is sleeping interruptibly, simulate a 2186 * wakeup so that when it is continued it will be made 2187 * runnable and can look at the signal. However, don't make 2188 * the PROCESS runnable, leave it stopped. 2189 * It may run a bit until it hits a thread_suspend_check(). 2190 */ 2191 wakeup_swapper = 0; 2192 PROC_SLOCK(p); 2193 thread_lock(td); 2194 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2195 wakeup_swapper = sleepq_abort(td, intrval); 2196 thread_unlock(td); 2197 PROC_SUNLOCK(p); 2198 if (wakeup_swapper) 2199 kick_proc0(); 2200 goto out; 2201 /* 2202 * Mutexes are short lived. Threads waiting on them will 2203 * hit thread_suspend_check() soon. 2204 */ 2205 } else if (p->p_state == PRS_NORMAL) { 2206 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2207 tdsigwakeup(td, sig, action, intrval); 2208 goto out; 2209 } 2210 2211 MPASS(action == SIG_DFL); 2212 2213 if (prop & SA_STOP) { 2214 if (p->p_flag & P_PPWAIT) 2215 goto out; 2216 p->p_flag |= P_STOPPED_SIG; 2217 p->p_xstat = sig; 2218 PROC_SLOCK(p); 2219 sig_suspend_threads(td, p, 1); 2220 if (p->p_numthreads == p->p_suspcount) { 2221 /* 2222 * only thread sending signal to another 2223 * process can reach here, if thread is sending 2224 * signal to its process, because thread does 2225 * not suspend itself here, p_numthreads 2226 * should never be equal to p_suspcount. 2227 */ 2228 thread_stopped(p); 2229 PROC_SUNLOCK(p); 2230 sigqueue_delete_proc(p, p->p_xstat); 2231 } else 2232 PROC_SUNLOCK(p); 2233 goto out; 2234 } 2235 } else { 2236 /* Not in "NORMAL" state. discard the signal. */ 2237 sigqueue_delete(sigqueue, sig); 2238 goto out; 2239 } 2240 2241 /* 2242 * The process is not stopped so we need to apply the signal to all the 2243 * running threads. 2244 */ 2245 runfast: 2246 tdsigwakeup(td, sig, action, intrval); 2247 PROC_SLOCK(p); 2248 thread_unsuspend(p); 2249 PROC_SUNLOCK(p); 2250 out: 2251 /* If we jump here, proc slock should not be owned. */ 2252 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2253 return (ret); 2254 } 2255 2256 /* 2257 * The force of a signal has been directed against a single 2258 * thread. We need to see what we can do about knocking it 2259 * out of any sleep it may be in etc. 2260 */ 2261 static void 2262 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2263 { 2264 struct proc *p = td->td_proc; 2265 register int prop; 2266 int wakeup_swapper; 2267 2268 wakeup_swapper = 0; 2269 PROC_LOCK_ASSERT(p, MA_OWNED); 2270 prop = sigprop(sig); 2271 2272 PROC_SLOCK(p); 2273 thread_lock(td); 2274 /* 2275 * Bring the priority of a thread up if we want it to get 2276 * killed in this lifetime. 2277 */ 2278 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2279 sched_prio(td, PUSER); 2280 if (TD_ON_SLEEPQ(td)) { 2281 /* 2282 * If thread is sleeping uninterruptibly 2283 * we can't interrupt the sleep... the signal will 2284 * be noticed when the process returns through 2285 * trap() or syscall(). 2286 */ 2287 if ((td->td_flags & TDF_SINTR) == 0) 2288 goto out; 2289 /* 2290 * If SIGCONT is default (or ignored) and process is 2291 * asleep, we are finished; the process should not 2292 * be awakened. 2293 */ 2294 if ((prop & SA_CONT) && action == SIG_DFL) { 2295 thread_unlock(td); 2296 PROC_SUNLOCK(p); 2297 sigqueue_delete(&p->p_sigqueue, sig); 2298 /* 2299 * It may be on either list in this state. 2300 * Remove from both for now. 2301 */ 2302 sigqueue_delete(&td->td_sigqueue, sig); 2303 return; 2304 } 2305 2306 /* 2307 * Give low priority threads a better chance to run. 2308 */ 2309 if (td->td_priority > PUSER) 2310 sched_prio(td, PUSER); 2311 2312 wakeup_swapper = sleepq_abort(td, intrval); 2313 } else { 2314 /* 2315 * Other states do nothing with the signal immediately, 2316 * other than kicking ourselves if we are running. 2317 * It will either never be noticed, or noticed very soon. 2318 */ 2319 #ifdef SMP 2320 if (TD_IS_RUNNING(td) && td != curthread) 2321 forward_signal(td); 2322 #endif 2323 } 2324 out: 2325 PROC_SUNLOCK(p); 2326 thread_unlock(td); 2327 if (wakeup_swapper) 2328 kick_proc0(); 2329 } 2330 2331 static void 2332 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2333 { 2334 struct thread *td2; 2335 int wakeup_swapper; 2336 2337 PROC_LOCK_ASSERT(p, MA_OWNED); 2338 PROC_SLOCK_ASSERT(p, MA_OWNED); 2339 2340 wakeup_swapper = 0; 2341 FOREACH_THREAD_IN_PROC(p, td2) { 2342 thread_lock(td2); 2343 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2344 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2345 (td2->td_flags & TDF_SINTR)) { 2346 if (td2->td_flags & TDF_SBDRY) { 2347 if (TD_IS_SUSPENDED(td2)) 2348 wakeup_swapper |= 2349 thread_unsuspend_one(td2); 2350 if (TD_ON_SLEEPQ(td2)) 2351 wakeup_swapper |= 2352 sleepq_abort(td2, ERESTART); 2353 } else if (!TD_IS_SUSPENDED(td2)) { 2354 thread_suspend_one(td2); 2355 } 2356 } else if (!TD_IS_SUSPENDED(td2)) { 2357 if (sending || td != td2) 2358 td2->td_flags |= TDF_ASTPENDING; 2359 #ifdef SMP 2360 if (TD_IS_RUNNING(td2) && td2 != td) 2361 forward_signal(td2); 2362 #endif 2363 } 2364 thread_unlock(td2); 2365 } 2366 if (wakeup_swapper) 2367 kick_proc0(); 2368 } 2369 2370 int 2371 ptracestop(struct thread *td, int sig) 2372 { 2373 struct proc *p = td->td_proc; 2374 2375 PROC_LOCK_ASSERT(p, MA_OWNED); 2376 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2377 &p->p_mtx.lock_object, "Stopping for traced signal"); 2378 2379 td->td_dbgflags |= TDB_XSIG; 2380 td->td_xsig = sig; 2381 PROC_SLOCK(p); 2382 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2383 if (p->p_flag & P_SINGLE_EXIT) { 2384 td->td_dbgflags &= ~TDB_XSIG; 2385 PROC_SUNLOCK(p); 2386 return (sig); 2387 } 2388 /* 2389 * Just make wait() to work, the last stopped thread 2390 * will win. 2391 */ 2392 p->p_xstat = sig; 2393 p->p_xthread = td; 2394 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2395 sig_suspend_threads(td, p, 0); 2396 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2397 td->td_dbgflags &= ~TDB_STOPATFORK; 2398 cv_broadcast(&p->p_dbgwait); 2399 } 2400 stopme: 2401 thread_suspend_switch(td); 2402 if (!(p->p_flag & P_TRACED)) { 2403 break; 2404 } 2405 if (td->td_dbgflags & TDB_SUSPEND) { 2406 if (p->p_flag & P_SINGLE_EXIT) 2407 break; 2408 goto stopme; 2409 } 2410 } 2411 PROC_SUNLOCK(p); 2412 return (td->td_xsig); 2413 } 2414 2415 static void 2416 reschedule_signals(struct proc *p, sigset_t block, int flags) 2417 { 2418 struct sigacts *ps; 2419 struct thread *td; 2420 int sig; 2421 2422 PROC_LOCK_ASSERT(p, MA_OWNED); 2423 if (SIGISEMPTY(p->p_siglist)) 2424 return; 2425 ps = p->p_sigacts; 2426 SIGSETAND(block, p->p_siglist); 2427 while ((sig = sig_ffs(&block)) != 0) { 2428 SIGDELSET(block, sig); 2429 td = sigtd(p, sig, 0); 2430 signotify(td); 2431 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2432 mtx_lock(&ps->ps_mtx); 2433 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2434 tdsigwakeup(td, sig, SIG_CATCH, 2435 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2436 ERESTART)); 2437 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2438 mtx_unlock(&ps->ps_mtx); 2439 } 2440 } 2441 2442 void 2443 tdsigcleanup(struct thread *td) 2444 { 2445 struct proc *p; 2446 sigset_t unblocked; 2447 2448 p = td->td_proc; 2449 PROC_LOCK_ASSERT(p, MA_OWNED); 2450 2451 sigqueue_flush(&td->td_sigqueue); 2452 if (p->p_numthreads == 1) 2453 return; 2454 2455 /* 2456 * Since we cannot handle signals, notify signal post code 2457 * about this by filling the sigmask. 2458 * 2459 * Also, if needed, wake up thread(s) that do not block the 2460 * same signals as the exiting thread, since the thread might 2461 * have been selected for delivery and woken up. 2462 */ 2463 SIGFILLSET(unblocked); 2464 SIGSETNAND(unblocked, td->td_sigmask); 2465 SIGFILLSET(td->td_sigmask); 2466 reschedule_signals(p, unblocked, 0); 2467 2468 } 2469 2470 /* 2471 * If the current process has received a signal (should be caught or cause 2472 * termination, should interrupt current syscall), return the signal number. 2473 * Stop signals with default action are processed immediately, then cleared; 2474 * they aren't returned. This is checked after each entry to the system for 2475 * a syscall or trap (though this can usually be done without calling issignal 2476 * by checking the pending signal masks in cursig.) The normal call 2477 * sequence is 2478 * 2479 * while (sig = cursig(curthread)) 2480 * postsig(sig); 2481 */ 2482 static int 2483 issignal(struct thread *td, int stop_allowed) 2484 { 2485 struct proc *p; 2486 struct sigacts *ps; 2487 struct sigqueue *queue; 2488 sigset_t sigpending; 2489 int sig, prop, newsig; 2490 2491 p = td->td_proc; 2492 ps = p->p_sigacts; 2493 mtx_assert(&ps->ps_mtx, MA_OWNED); 2494 PROC_LOCK_ASSERT(p, MA_OWNED); 2495 for (;;) { 2496 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2497 2498 sigpending = td->td_sigqueue.sq_signals; 2499 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2500 SIGSETNAND(sigpending, td->td_sigmask); 2501 2502 if (p->p_flag & P_PPWAIT) 2503 SIG_STOPSIGMASK(sigpending); 2504 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2505 return (0); 2506 sig = sig_ffs(&sigpending); 2507 2508 if (p->p_stops & S_SIG) { 2509 mtx_unlock(&ps->ps_mtx); 2510 stopevent(p, S_SIG, sig); 2511 mtx_lock(&ps->ps_mtx); 2512 } 2513 2514 /* 2515 * We should see pending but ignored signals 2516 * only if P_TRACED was on when they were posted. 2517 */ 2518 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2519 sigqueue_delete(&td->td_sigqueue, sig); 2520 sigqueue_delete(&p->p_sigqueue, sig); 2521 continue; 2522 } 2523 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2524 /* 2525 * If traced, always stop. 2526 * Remove old signal from queue before the stop. 2527 * XXX shrug off debugger, it causes siginfo to 2528 * be thrown away. 2529 */ 2530 queue = &td->td_sigqueue; 2531 td->td_dbgksi.ksi_signo = 0; 2532 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2533 queue = &p->p_sigqueue; 2534 sigqueue_get(queue, sig, &td->td_dbgksi); 2535 } 2536 2537 mtx_unlock(&ps->ps_mtx); 2538 newsig = ptracestop(td, sig); 2539 mtx_lock(&ps->ps_mtx); 2540 2541 if (sig != newsig) { 2542 2543 /* 2544 * If parent wants us to take the signal, 2545 * then it will leave it in p->p_xstat; 2546 * otherwise we just look for signals again. 2547 */ 2548 if (newsig == 0) 2549 continue; 2550 sig = newsig; 2551 2552 /* 2553 * Put the new signal into td_sigqueue. If the 2554 * signal is being masked, look for other signals. 2555 */ 2556 sigqueue_add(queue, sig, NULL); 2557 if (SIGISMEMBER(td->td_sigmask, sig)) 2558 continue; 2559 signotify(td); 2560 } else { 2561 if (td->td_dbgksi.ksi_signo != 0) { 2562 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2563 if (sigqueue_add(&td->td_sigqueue, sig, 2564 &td->td_dbgksi) != 0) 2565 td->td_dbgksi.ksi_signo = 0; 2566 } 2567 if (td->td_dbgksi.ksi_signo == 0) 2568 sigqueue_add(&td->td_sigqueue, sig, 2569 NULL); 2570 } 2571 2572 /* 2573 * If the traced bit got turned off, go back up 2574 * to the top to rescan signals. This ensures 2575 * that p_sig* and p_sigact are consistent. 2576 */ 2577 if ((p->p_flag & P_TRACED) == 0) 2578 continue; 2579 } 2580 2581 prop = sigprop(sig); 2582 2583 /* 2584 * Decide whether the signal should be returned. 2585 * Return the signal's number, or fall through 2586 * to clear it from the pending mask. 2587 */ 2588 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2589 2590 case (intptr_t)SIG_DFL: 2591 /* 2592 * Don't take default actions on system processes. 2593 */ 2594 if (p->p_pid <= 1) { 2595 #ifdef DIAGNOSTIC 2596 /* 2597 * Are you sure you want to ignore SIGSEGV 2598 * in init? XXX 2599 */ 2600 printf("Process (pid %lu) got signal %d\n", 2601 (u_long)p->p_pid, sig); 2602 #endif 2603 break; /* == ignore */ 2604 } 2605 /* 2606 * If there is a pending stop signal to process 2607 * with default action, stop here, 2608 * then clear the signal. However, 2609 * if process is member of an orphaned 2610 * process group, ignore tty stop signals. 2611 */ 2612 if (prop & SA_STOP) { 2613 if (p->p_flag & P_TRACED || 2614 (p->p_pgrp->pg_jobc == 0 && 2615 prop & SA_TTYSTOP)) 2616 break; /* == ignore */ 2617 2618 /* Ignore, but do not drop the stop signal. */ 2619 if (stop_allowed != SIG_STOP_ALLOWED) 2620 return (sig); 2621 mtx_unlock(&ps->ps_mtx); 2622 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2623 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2624 p->p_flag |= P_STOPPED_SIG; 2625 p->p_xstat = sig; 2626 PROC_SLOCK(p); 2627 sig_suspend_threads(td, p, 0); 2628 thread_suspend_switch(td); 2629 PROC_SUNLOCK(p); 2630 mtx_lock(&ps->ps_mtx); 2631 break; 2632 } else if (prop & SA_IGNORE) { 2633 /* 2634 * Except for SIGCONT, shouldn't get here. 2635 * Default action is to ignore; drop it. 2636 */ 2637 break; /* == ignore */ 2638 } else 2639 return (sig); 2640 /*NOTREACHED*/ 2641 2642 case (intptr_t)SIG_IGN: 2643 /* 2644 * Masking above should prevent us ever trying 2645 * to take action on an ignored signal other 2646 * than SIGCONT, unless process is traced. 2647 */ 2648 if ((prop & SA_CONT) == 0 && 2649 (p->p_flag & P_TRACED) == 0) 2650 printf("issignal\n"); 2651 break; /* == ignore */ 2652 2653 default: 2654 /* 2655 * This signal has an action, let 2656 * postsig() process it. 2657 */ 2658 return (sig); 2659 } 2660 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2661 sigqueue_delete(&p->p_sigqueue, sig); 2662 } 2663 /* NOTREACHED */ 2664 } 2665 2666 void 2667 thread_stopped(struct proc *p) 2668 { 2669 int n; 2670 2671 PROC_LOCK_ASSERT(p, MA_OWNED); 2672 PROC_SLOCK_ASSERT(p, MA_OWNED); 2673 n = p->p_suspcount; 2674 if (p == curproc) 2675 n++; 2676 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2677 PROC_SUNLOCK(p); 2678 p->p_flag &= ~P_WAITED; 2679 PROC_LOCK(p->p_pptr); 2680 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2681 CLD_TRAPPED : CLD_STOPPED); 2682 PROC_UNLOCK(p->p_pptr); 2683 PROC_SLOCK(p); 2684 } 2685 } 2686 2687 /* 2688 * Take the action for the specified signal 2689 * from the current set of pending signals. 2690 */ 2691 int 2692 postsig(sig) 2693 register int sig; 2694 { 2695 struct thread *td = curthread; 2696 register struct proc *p = td->td_proc; 2697 struct sigacts *ps; 2698 sig_t action; 2699 ksiginfo_t ksi; 2700 sigset_t returnmask, mask; 2701 2702 KASSERT(sig != 0, ("postsig")); 2703 2704 PROC_LOCK_ASSERT(p, MA_OWNED); 2705 ps = p->p_sigacts; 2706 mtx_assert(&ps->ps_mtx, MA_OWNED); 2707 ksiginfo_init(&ksi); 2708 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2709 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2710 return (0); 2711 ksi.ksi_signo = sig; 2712 if (ksi.ksi_code == SI_TIMER) 2713 itimer_accept(p, ksi.ksi_timerid, &ksi); 2714 action = ps->ps_sigact[_SIG_IDX(sig)]; 2715 #ifdef KTRACE 2716 if (KTRPOINT(td, KTR_PSIG)) 2717 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2718 &td->td_oldsigmask : &td->td_sigmask, 0); 2719 #endif 2720 if (p->p_stops & S_SIG) { 2721 mtx_unlock(&ps->ps_mtx); 2722 stopevent(p, S_SIG, sig); 2723 mtx_lock(&ps->ps_mtx); 2724 } 2725 2726 if (action == SIG_DFL) { 2727 /* 2728 * Default action, where the default is to kill 2729 * the process. (Other cases were ignored above.) 2730 */ 2731 mtx_unlock(&ps->ps_mtx); 2732 sigexit(td, sig); 2733 /* NOTREACHED */ 2734 } else { 2735 /* 2736 * If we get here, the signal must be caught. 2737 */ 2738 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2739 ("postsig action")); 2740 /* 2741 * Set the new mask value and also defer further 2742 * occurrences of this signal. 2743 * 2744 * Special case: user has done a sigsuspend. Here the 2745 * current mask is not of interest, but rather the 2746 * mask from before the sigsuspend is what we want 2747 * restored after the signal processing is completed. 2748 */ 2749 if (td->td_pflags & TDP_OLDMASK) { 2750 returnmask = td->td_oldsigmask; 2751 td->td_pflags &= ~TDP_OLDMASK; 2752 } else 2753 returnmask = td->td_sigmask; 2754 2755 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2756 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2757 SIGADDSET(mask, sig); 2758 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2759 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2760 2761 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2762 /* 2763 * See kern_sigaction() for origin of this code. 2764 */ 2765 SIGDELSET(ps->ps_sigcatch, sig); 2766 if (sig != SIGCONT && 2767 sigprop(sig) & SA_IGNORE) 2768 SIGADDSET(ps->ps_sigignore, sig); 2769 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2770 } 2771 td->td_ru.ru_nsignals++; 2772 if (p->p_sig == sig) { 2773 p->p_code = 0; 2774 p->p_sig = 0; 2775 } 2776 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2777 } 2778 return (1); 2779 } 2780 2781 /* 2782 * Kill the current process for stated reason. 2783 */ 2784 void 2785 killproc(p, why) 2786 struct proc *p; 2787 char *why; 2788 { 2789 2790 PROC_LOCK_ASSERT(p, MA_OWNED); 2791 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2792 p, p->p_pid, p->p_comm); 2793 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2794 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2795 p->p_flag |= P_WKILLED; 2796 psignal(p, SIGKILL); 2797 } 2798 2799 /* 2800 * Force the current process to exit with the specified signal, dumping core 2801 * if appropriate. We bypass the normal tests for masked and caught signals, 2802 * allowing unrecoverable failures to terminate the process without changing 2803 * signal state. Mark the accounting record with the signal termination. 2804 * If dumping core, save the signal number for the debugger. Calls exit and 2805 * does not return. 2806 */ 2807 void 2808 sigexit(td, sig) 2809 struct thread *td; 2810 int sig; 2811 { 2812 struct proc *p = td->td_proc; 2813 2814 PROC_LOCK_ASSERT(p, MA_OWNED); 2815 p->p_acflag |= AXSIG; 2816 /* 2817 * We must be single-threading to generate a core dump. This 2818 * ensures that the registers in the core file are up-to-date. 2819 * Also, the ELF dump handler assumes that the thread list doesn't 2820 * change out from under it. 2821 * 2822 * XXX If another thread attempts to single-thread before us 2823 * (e.g. via fork()), we won't get a dump at all. 2824 */ 2825 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2826 p->p_sig = sig; 2827 /* 2828 * Log signals which would cause core dumps 2829 * (Log as LOG_INFO to appease those who don't want 2830 * these messages.) 2831 * XXX : Todo, as well as euid, write out ruid too 2832 * Note that coredump() drops proc lock. 2833 */ 2834 if (coredump(td) == 0) 2835 sig |= WCOREFLAG; 2836 if (kern_logsigexit) 2837 log(LOG_INFO, 2838 "pid %d (%s), uid %d: exited on signal %d%s\n", 2839 p->p_pid, p->p_comm, 2840 td->td_ucred ? td->td_ucred->cr_uid : -1, 2841 sig &~ WCOREFLAG, 2842 sig & WCOREFLAG ? " (core dumped)" : ""); 2843 } else 2844 PROC_UNLOCK(p); 2845 exit1(td, W_EXITCODE(0, sig)); 2846 /* NOTREACHED */ 2847 } 2848 2849 /* 2850 * Send queued SIGCHLD to parent when child process's state 2851 * is changed. 2852 */ 2853 static void 2854 sigparent(struct proc *p, int reason, int status) 2855 { 2856 PROC_LOCK_ASSERT(p, MA_OWNED); 2857 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2858 2859 if (p->p_ksi != NULL) { 2860 p->p_ksi->ksi_signo = SIGCHLD; 2861 p->p_ksi->ksi_code = reason; 2862 p->p_ksi->ksi_status = status; 2863 p->p_ksi->ksi_pid = p->p_pid; 2864 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2865 if (KSI_ONQ(p->p_ksi)) 2866 return; 2867 } 2868 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2869 } 2870 2871 static void 2872 childproc_jobstate(struct proc *p, int reason, int status) 2873 { 2874 struct sigacts *ps; 2875 2876 PROC_LOCK_ASSERT(p, MA_OWNED); 2877 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2878 2879 /* 2880 * Wake up parent sleeping in kern_wait(), also send 2881 * SIGCHLD to parent, but SIGCHLD does not guarantee 2882 * that parent will awake, because parent may masked 2883 * the signal. 2884 */ 2885 p->p_pptr->p_flag |= P_STATCHILD; 2886 wakeup(p->p_pptr); 2887 2888 ps = p->p_pptr->p_sigacts; 2889 mtx_lock(&ps->ps_mtx); 2890 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2891 mtx_unlock(&ps->ps_mtx); 2892 sigparent(p, reason, status); 2893 } else 2894 mtx_unlock(&ps->ps_mtx); 2895 } 2896 2897 void 2898 childproc_stopped(struct proc *p, int reason) 2899 { 2900 childproc_jobstate(p, reason, p->p_xstat); 2901 } 2902 2903 void 2904 childproc_continued(struct proc *p) 2905 { 2906 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2907 } 2908 2909 void 2910 childproc_exited(struct proc *p) 2911 { 2912 int reason; 2913 int status = p->p_xstat; /* convert to int */ 2914 2915 reason = CLD_EXITED; 2916 if (WCOREDUMP(status)) 2917 reason = CLD_DUMPED; 2918 else if (WIFSIGNALED(status)) 2919 reason = CLD_KILLED; 2920 /* 2921 * XXX avoid calling wakeup(p->p_pptr), the work is 2922 * done in exit1(). 2923 */ 2924 sigparent(p, reason, status); 2925 } 2926 2927 /* 2928 * We only have 1 character for the core count in the format 2929 * string, so the range will be 0-9 2930 */ 2931 #define MAX_NUM_CORES 10 2932 static int num_cores = 5; 2933 2934 static int 2935 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 2936 { 2937 int error; 2938 int new_val; 2939 2940 new_val = num_cores; 2941 error = sysctl_handle_int(oidp, &new_val, 0, req); 2942 if (error != 0 || req->newptr == NULL) 2943 return (error); 2944 if (new_val > MAX_NUM_CORES) 2945 new_val = MAX_NUM_CORES; 2946 if (new_val < 0) 2947 new_val = 0; 2948 num_cores = new_val; 2949 return (0); 2950 } 2951 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 2952 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 2953 2954 #if defined(COMPRESS_USER_CORES) 2955 int compress_user_cores = 1; 2956 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 2957 &compress_user_cores, 0, ""); 2958 2959 int compress_user_cores_gzlevel = -1; /* default level */ 2960 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 2961 &compress_user_cores_gzlevel, -1, "user core gz compression level"); 2962 2963 #define GZ_SUFFIX ".gz" 2964 #define GZ_SUFFIX_LEN 3 2965 #endif 2966 2967 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2968 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2969 sizeof(corefilename), "process corefile name format string"); 2970 2971 /* 2972 * expand_name(name, uid, pid, td, compress) 2973 * Expand the name described in corefilename, using name, uid, and pid. 2974 * corefilename is a printf-like string, with three format specifiers: 2975 * %N name of process ("name") 2976 * %P process id (pid) 2977 * %U user id (uid) 2978 * For example, "%N.core" is the default; they can be disabled completely 2979 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2980 * This is controlled by the sysctl variable kern.corefile (see above). 2981 */ 2982 static char * 2983 expand_name(const char *name, uid_t uid, pid_t pid, struct thread *td, 2984 int compress) 2985 { 2986 struct sbuf sb; 2987 const char *format; 2988 char *temp; 2989 size_t i; 2990 int indexpos; 2991 char *hostname; 2992 2993 hostname = NULL; 2994 format = corefilename; 2995 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2996 if (temp == NULL) 2997 return (NULL); 2998 indexpos = -1; 2999 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 3000 for (i = 0; format[i]; i++) { 3001 switch (format[i]) { 3002 case '%': /* Format character */ 3003 i++; 3004 switch (format[i]) { 3005 case '%': 3006 sbuf_putc(&sb, '%'); 3007 break; 3008 case 'H': /* hostname */ 3009 if (hostname == NULL) { 3010 hostname = malloc(MAXHOSTNAMELEN, 3011 M_TEMP, M_NOWAIT); 3012 if (hostname == NULL) { 3013 log(LOG_ERR, 3014 "pid %ld (%s), uid (%lu): " 3015 "unable to alloc memory " 3016 "for corefile hostname\n", 3017 (long)pid, name, 3018 (u_long)uid); 3019 goto nomem; 3020 } 3021 } 3022 getcredhostname(td->td_ucred, hostname, 3023 MAXHOSTNAMELEN); 3024 sbuf_printf(&sb, "%s", hostname); 3025 break; 3026 case 'I': /* autoincrementing index */ 3027 sbuf_printf(&sb, "0"); 3028 indexpos = sbuf_len(&sb) - 1; 3029 break; 3030 case 'N': /* process name */ 3031 sbuf_printf(&sb, "%s", name); 3032 break; 3033 case 'P': /* process id */ 3034 sbuf_printf(&sb, "%u", pid); 3035 break; 3036 case 'U': /* user id */ 3037 sbuf_printf(&sb, "%u", uid); 3038 break; 3039 default: 3040 log(LOG_ERR, 3041 "Unknown format character %c in " 3042 "corename `%s'\n", format[i], format); 3043 } 3044 break; 3045 default: 3046 sbuf_putc(&sb, format[i]); 3047 } 3048 } 3049 free(hostname, M_TEMP); 3050 #ifdef COMPRESS_USER_CORES 3051 if (compress) { 3052 sbuf_printf(&sb, GZ_SUFFIX); 3053 } 3054 #endif 3055 if (sbuf_error(&sb) != 0) { 3056 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3057 "long\n", (long)pid, name, (u_long)uid); 3058 nomem: 3059 sbuf_delete(&sb); 3060 free(temp, M_TEMP); 3061 return (NULL); 3062 } 3063 sbuf_finish(&sb); 3064 sbuf_delete(&sb); 3065 3066 /* 3067 * If the core format has a %I in it, then we need to check 3068 * for existing corefiles before returning a name. 3069 * To do this we iterate over 0..num_cores to find a 3070 * non-existing core file name to use. 3071 */ 3072 if (indexpos != -1) { 3073 struct nameidata nd; 3074 int error, n; 3075 int flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3076 int cmode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; 3077 int vfslocked; 3078 3079 for (n = 0; n < num_cores; n++) { 3080 temp[indexpos] = '0' + n; 3081 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, 3082 temp, td); 3083 error = vn_open(&nd, &flags, cmode, NULL); 3084 if (error) { 3085 if (error == EEXIST) { 3086 continue; 3087 } 3088 log(LOG_ERR, 3089 "pid %d (%s), uid (%u): Path `%s' failed " 3090 "on initial open test, error = %d\n", 3091 pid, name, uid, temp, error); 3092 free(temp, M_TEMP); 3093 return (NULL); 3094 } 3095 vfslocked = NDHASGIANT(&nd); 3096 NDFREE(&nd, NDF_ONLY_PNBUF); 3097 VOP_UNLOCK(nd.ni_vp, 0); 3098 error = vn_close(nd.ni_vp, FWRITE, td->td_ucred, td); 3099 VFS_UNLOCK_GIANT(vfslocked); 3100 if (error) { 3101 log(LOG_ERR, 3102 "pid %d (%s), uid (%u): Path `%s' failed " 3103 "on close after initial open test, " 3104 "error = %d\n", 3105 pid, name, uid, temp, error); 3106 free(temp, M_TEMP); 3107 return (NULL); 3108 } 3109 break; 3110 } 3111 } 3112 return (temp); 3113 } 3114 3115 /* 3116 * Dump a process' core. The main routine does some 3117 * policy checking, and creates the name of the coredump; 3118 * then it passes on a vnode and a size limit to the process-specific 3119 * coredump routine if there is one; if there _is not_ one, it returns 3120 * ENOSYS; otherwise it returns the error from the process-specific routine. 3121 */ 3122 3123 static int 3124 coredump(struct thread *td) 3125 { 3126 struct proc *p = td->td_proc; 3127 register struct vnode *vp; 3128 register struct ucred *cred = td->td_ucred; 3129 struct flock lf; 3130 struct nameidata nd; 3131 struct vattr vattr; 3132 int error, error1, flags, locked; 3133 struct mount *mp; 3134 char *name; /* name of corefile */ 3135 off_t limit; 3136 int vfslocked; 3137 int compress; 3138 3139 #ifdef COMPRESS_USER_CORES 3140 compress = compress_user_cores; 3141 #else 3142 compress = 0; 3143 #endif 3144 PROC_LOCK_ASSERT(p, MA_OWNED); 3145 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3146 _STOPEVENT(p, S_CORE, 0); 3147 3148 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid, td, 3149 compress); 3150 if (name == NULL) { 3151 PROC_UNLOCK(p); 3152 #ifdef AUDIT 3153 audit_proc_coredump(td, NULL, EINVAL); 3154 #endif 3155 return (EINVAL); 3156 } 3157 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3158 PROC_UNLOCK(p); 3159 #ifdef AUDIT 3160 audit_proc_coredump(td, name, EFAULT); 3161 #endif 3162 free(name, M_TEMP); 3163 return (EFAULT); 3164 } 3165 3166 /* 3167 * Note that the bulk of limit checking is done after 3168 * the corefile is created. The exception is if the limit 3169 * for corefiles is 0, in which case we don't bother 3170 * creating the corefile at all. This layout means that 3171 * a corefile is truncated instead of not being created, 3172 * if it is larger than the limit. 3173 */ 3174 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3175 PROC_UNLOCK(p); 3176 if (limit == 0) { 3177 #ifdef AUDIT 3178 audit_proc_coredump(td, name, EFBIG); 3179 #endif 3180 free(name, M_TEMP); 3181 return (EFBIG); 3182 } 3183 3184 restart: 3185 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3186 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3187 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3188 cred, NULL); 3189 if (error) { 3190 #ifdef AUDIT 3191 audit_proc_coredump(td, name, error); 3192 #endif 3193 free(name, M_TEMP); 3194 return (error); 3195 } 3196 vfslocked = NDHASGIANT(&nd); 3197 NDFREE(&nd, NDF_ONLY_PNBUF); 3198 vp = nd.ni_vp; 3199 3200 /* Don't dump to non-regular files or files with links. */ 3201 if (vp->v_type != VREG || 3202 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3203 VOP_UNLOCK(vp, 0); 3204 error = EFAULT; 3205 goto close; 3206 } 3207 3208 VOP_UNLOCK(vp, 0); 3209 lf.l_whence = SEEK_SET; 3210 lf.l_start = 0; 3211 lf.l_len = 0; 3212 lf.l_type = F_WRLCK; 3213 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3214 3215 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3216 lf.l_type = F_UNLCK; 3217 if (locked) 3218 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3219 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3220 goto out; 3221 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3222 goto out; 3223 VFS_UNLOCK_GIANT(vfslocked); 3224 goto restart; 3225 } 3226 3227 VATTR_NULL(&vattr); 3228 vattr.va_size = 0; 3229 if (set_core_nodump_flag) 3230 vattr.va_flags = UF_NODUMP; 3231 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3232 VOP_SETATTR(vp, &vattr, cred); 3233 VOP_UNLOCK(vp, 0); 3234 vn_finished_write(mp); 3235 PROC_LOCK(p); 3236 p->p_acflag |= ACORE; 3237 PROC_UNLOCK(p); 3238 3239 error = p->p_sysent->sv_coredump ? 3240 p->p_sysent->sv_coredump(td, vp, limit, compress ? IMGACT_CORE_COMPRESS : 0) : 3241 ENOSYS; 3242 3243 if (locked) { 3244 lf.l_type = F_UNLCK; 3245 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3246 } 3247 close: 3248 error1 = vn_close(vp, FWRITE, cred, td); 3249 if (error == 0) 3250 error = error1; 3251 out: 3252 #ifdef AUDIT 3253 audit_proc_coredump(td, name, error); 3254 #endif 3255 free(name, M_TEMP); 3256 VFS_UNLOCK_GIANT(vfslocked); 3257 return (error); 3258 } 3259 3260 /* 3261 * Nonexistent system call-- signal process (may want to handle it). Flag 3262 * error in case process won't see signal immediately (blocked or ignored). 3263 */ 3264 #ifndef _SYS_SYSPROTO_H_ 3265 struct nosys_args { 3266 int dummy; 3267 }; 3268 #endif 3269 /* ARGSUSED */ 3270 int 3271 nosys(td, args) 3272 struct thread *td; 3273 struct nosys_args *args; 3274 { 3275 struct proc *p = td->td_proc; 3276 3277 PROC_LOCK(p); 3278 psignal(p, SIGSYS); 3279 PROC_UNLOCK(p); 3280 return (ENOSYS); 3281 } 3282 3283 /* 3284 * Send a SIGIO or SIGURG signal to a process or process group using stored 3285 * credentials rather than those of the current process. 3286 */ 3287 void 3288 pgsigio(sigiop, sig, checkctty) 3289 struct sigio **sigiop; 3290 int sig, checkctty; 3291 { 3292 ksiginfo_t ksi; 3293 struct sigio *sigio; 3294 3295 ksiginfo_init(&ksi); 3296 ksi.ksi_signo = sig; 3297 ksi.ksi_code = SI_KERNEL; 3298 3299 SIGIO_LOCK(); 3300 sigio = *sigiop; 3301 if (sigio == NULL) { 3302 SIGIO_UNLOCK(); 3303 return; 3304 } 3305 if (sigio->sio_pgid > 0) { 3306 PROC_LOCK(sigio->sio_proc); 3307 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3308 psignal(sigio->sio_proc, sig); 3309 PROC_UNLOCK(sigio->sio_proc); 3310 } else if (sigio->sio_pgid < 0) { 3311 struct proc *p; 3312 3313 PGRP_LOCK(sigio->sio_pgrp); 3314 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3315 PROC_LOCK(p); 3316 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3317 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3318 psignal(p, sig); 3319 PROC_UNLOCK(p); 3320 } 3321 PGRP_UNLOCK(sigio->sio_pgrp); 3322 } 3323 SIGIO_UNLOCK(); 3324 } 3325 3326 static int 3327 filt_sigattach(struct knote *kn) 3328 { 3329 struct proc *p = curproc; 3330 3331 kn->kn_ptr.p_proc = p; 3332 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3333 3334 knlist_add(&p->p_klist, kn, 0); 3335 3336 return (0); 3337 } 3338 3339 static void 3340 filt_sigdetach(struct knote *kn) 3341 { 3342 struct proc *p = kn->kn_ptr.p_proc; 3343 3344 knlist_remove(&p->p_klist, kn, 0); 3345 } 3346 3347 /* 3348 * signal knotes are shared with proc knotes, so we apply a mask to 3349 * the hint in order to differentiate them from process hints. This 3350 * could be avoided by using a signal-specific knote list, but probably 3351 * isn't worth the trouble. 3352 */ 3353 static int 3354 filt_signal(struct knote *kn, long hint) 3355 { 3356 3357 if (hint & NOTE_SIGNAL) { 3358 hint &= ~NOTE_SIGNAL; 3359 3360 if (kn->kn_id == hint) 3361 kn->kn_data++; 3362 } 3363 return (kn->kn_data != 0); 3364 } 3365 3366 struct sigacts * 3367 sigacts_alloc(void) 3368 { 3369 struct sigacts *ps; 3370 3371 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3372 ps->ps_refcnt = 1; 3373 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3374 return (ps); 3375 } 3376 3377 void 3378 sigacts_free(struct sigacts *ps) 3379 { 3380 3381 mtx_lock(&ps->ps_mtx); 3382 ps->ps_refcnt--; 3383 if (ps->ps_refcnt == 0) { 3384 mtx_destroy(&ps->ps_mtx); 3385 free(ps, M_SUBPROC); 3386 } else 3387 mtx_unlock(&ps->ps_mtx); 3388 } 3389 3390 struct sigacts * 3391 sigacts_hold(struct sigacts *ps) 3392 { 3393 mtx_lock(&ps->ps_mtx); 3394 ps->ps_refcnt++; 3395 mtx_unlock(&ps->ps_mtx); 3396 return (ps); 3397 } 3398 3399 void 3400 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3401 { 3402 3403 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3404 mtx_lock(&src->ps_mtx); 3405 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3406 mtx_unlock(&src->ps_mtx); 3407 } 3408 3409 int 3410 sigacts_shared(struct sigacts *ps) 3411 { 3412 int shared; 3413 3414 mtx_lock(&ps->ps_mtx); 3415 shared = ps->ps_refcnt > 1; 3416 mtx_unlock(&ps->ps_mtx); 3417 return (shared); 3418 } 3419