1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 #include "opt_core.h" 44 #include "opt_procdesc.h" 45 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/signalvar.h> 49 #include <sys/vnode.h> 50 #include <sys/acct.h> 51 #include <sys/capability.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/imgact.h> 56 #include <sys/kernel.h> 57 #include <sys/ktr.h> 58 #include <sys/ktrace.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/proc.h> 64 #include <sys/procdesc.h> 65 #include <sys/posix4.h> 66 #include <sys/pioctl.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sdt.h> 70 #include <sys/sbuf.h> 71 #include <sys/sleepqueue.h> 72 #include <sys/smp.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysent.h> 78 #include <sys/syslog.h> 79 #include <sys/sysproto.h> 80 #include <sys/timers.h> 81 #include <sys/unistd.h> 82 #include <sys/wait.h> 83 #include <vm/vm.h> 84 #include <vm/vm_extern.h> 85 #include <vm/uma.h> 86 87 #include <sys/jail.h> 88 89 #include <machine/cpu.h> 90 91 #include <security/audit/audit.h> 92 93 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 94 95 SDT_PROVIDER_DECLARE(proc); 96 SDT_PROBE_DEFINE(proc, kernel, , signal_send, signal-send); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 99 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 100 SDT_PROBE_DEFINE(proc, kernel, , signal_clear, signal-clear); 101 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 102 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 103 SDT_PROBE_DEFINE(proc, kernel, , signal_discard, signal-discard); 104 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 105 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 106 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 107 108 static int coredump(struct thread *); 109 static char *expand_name(const char *, uid_t, pid_t, struct thread *, int); 110 static int killpg1(struct thread *td, int sig, int pgid, int all, 111 ksiginfo_t *ksi); 112 static int issignal(struct thread *td, int stop_allowed); 113 static int sigprop(int sig); 114 static void tdsigwakeup(struct thread *, int, sig_t, int); 115 static void sig_suspend_threads(struct thread *, struct proc *, int); 116 static int filt_sigattach(struct knote *kn); 117 static void filt_sigdetach(struct knote *kn); 118 static int filt_signal(struct knote *kn, long hint); 119 static struct thread *sigtd(struct proc *p, int sig, int prop); 120 static void sigqueue_start(void); 121 122 static uma_zone_t ksiginfo_zone = NULL; 123 struct filterops sig_filtops = { 124 .f_isfd = 0, 125 .f_attach = filt_sigattach, 126 .f_detach = filt_sigdetach, 127 .f_event = filt_signal, 128 }; 129 130 static int kern_logsigexit = 1; 131 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 132 &kern_logsigexit, 0, 133 "Log processes quitting on abnormal signals to syslog(3)"); 134 135 static int kern_forcesigexit = 1; 136 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 137 &kern_forcesigexit, 0, "Force trap signal to be handled"); 138 139 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 140 "POSIX real time signal"); 141 142 static int max_pending_per_proc = 128; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 144 &max_pending_per_proc, 0, "Max pending signals per proc"); 145 146 static int preallocate_siginfo = 1024; 147 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 149 &preallocate_siginfo, 0, "Preallocated signal memory size"); 150 151 static int signal_overflow = 0; 152 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 153 &signal_overflow, 0, "Number of signals overflew"); 154 155 static int signal_alloc_fail = 0; 156 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 157 &signal_alloc_fail, 0, "signals failed to be allocated"); 158 159 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 160 161 /* 162 * Policy -- Can ucred cr1 send SIGIO to process cr2? 163 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 164 * in the right situations. 165 */ 166 #define CANSIGIO(cr1, cr2) \ 167 ((cr1)->cr_uid == 0 || \ 168 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 169 (cr1)->cr_uid == (cr2)->cr_ruid || \ 170 (cr1)->cr_ruid == (cr2)->cr_uid || \ 171 (cr1)->cr_uid == (cr2)->cr_uid) 172 173 static int sugid_coredump; 174 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 175 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 176 177 static int do_coredump = 1; 178 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 179 &do_coredump, 0, "Enable/Disable coredumps"); 180 181 static int set_core_nodump_flag = 0; 182 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 183 0, "Enable setting the NODUMP flag on coredump files"); 184 185 /* 186 * Signal properties and actions. 187 * The array below categorizes the signals and their default actions 188 * according to the following properties: 189 */ 190 #define SA_KILL 0x01 /* terminates process by default */ 191 #define SA_CORE 0x02 /* ditto and coredumps */ 192 #define SA_STOP 0x04 /* suspend process */ 193 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 194 #define SA_IGNORE 0x10 /* ignore by default */ 195 #define SA_CONT 0x20 /* continue if suspended */ 196 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 197 #define SA_PROC 0x80 /* deliverable to any thread */ 198 199 static int sigproptbl[NSIG] = { 200 SA_KILL|SA_PROC, /* SIGHUP */ 201 SA_KILL|SA_PROC, /* SIGINT */ 202 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 203 SA_KILL|SA_CORE, /* SIGILL */ 204 SA_KILL|SA_CORE, /* SIGTRAP */ 205 SA_KILL|SA_CORE, /* SIGABRT */ 206 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 207 SA_KILL|SA_CORE, /* SIGFPE */ 208 SA_KILL|SA_PROC, /* SIGKILL */ 209 SA_KILL|SA_CORE, /* SIGBUS */ 210 SA_KILL|SA_CORE, /* SIGSEGV */ 211 SA_KILL|SA_CORE, /* SIGSYS */ 212 SA_KILL|SA_PROC, /* SIGPIPE */ 213 SA_KILL|SA_PROC, /* SIGALRM */ 214 SA_KILL|SA_PROC, /* SIGTERM */ 215 SA_IGNORE|SA_PROC, /* SIGURG */ 216 SA_STOP|SA_PROC, /* SIGSTOP */ 217 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 218 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 219 SA_IGNORE|SA_PROC, /* SIGCHLD */ 220 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 221 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 222 SA_IGNORE|SA_PROC, /* SIGIO */ 223 SA_KILL, /* SIGXCPU */ 224 SA_KILL, /* SIGXFSZ */ 225 SA_KILL|SA_PROC, /* SIGVTALRM */ 226 SA_KILL|SA_PROC, /* SIGPROF */ 227 SA_IGNORE|SA_PROC, /* SIGWINCH */ 228 SA_IGNORE|SA_PROC, /* SIGINFO */ 229 SA_KILL|SA_PROC, /* SIGUSR1 */ 230 SA_KILL|SA_PROC, /* SIGUSR2 */ 231 }; 232 233 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 234 235 static void 236 sigqueue_start(void) 237 { 238 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 239 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 240 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 241 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 242 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 243 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 244 } 245 246 ksiginfo_t * 247 ksiginfo_alloc(int wait) 248 { 249 int flags; 250 251 flags = M_ZERO; 252 if (! wait) 253 flags |= M_NOWAIT; 254 if (ksiginfo_zone != NULL) 255 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 256 return (NULL); 257 } 258 259 void 260 ksiginfo_free(ksiginfo_t *ksi) 261 { 262 uma_zfree(ksiginfo_zone, ksi); 263 } 264 265 static __inline int 266 ksiginfo_tryfree(ksiginfo_t *ksi) 267 { 268 if (!(ksi->ksi_flags & KSI_EXT)) { 269 uma_zfree(ksiginfo_zone, ksi); 270 return (1); 271 } 272 return (0); 273 } 274 275 void 276 sigqueue_init(sigqueue_t *list, struct proc *p) 277 { 278 SIGEMPTYSET(list->sq_signals); 279 SIGEMPTYSET(list->sq_kill); 280 TAILQ_INIT(&list->sq_list); 281 list->sq_proc = p; 282 list->sq_flags = SQ_INIT; 283 } 284 285 /* 286 * Get a signal's ksiginfo. 287 * Return: 288 * 0 - signal not found 289 * others - signal number 290 */ 291 static int 292 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 293 { 294 struct proc *p = sq->sq_proc; 295 struct ksiginfo *ksi, *next; 296 int count = 0; 297 298 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 299 300 if (!SIGISMEMBER(sq->sq_signals, signo)) 301 return (0); 302 303 if (SIGISMEMBER(sq->sq_kill, signo)) { 304 count++; 305 SIGDELSET(sq->sq_kill, signo); 306 } 307 308 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 309 if (ksi->ksi_signo == signo) { 310 if (count == 0) { 311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 312 ksi->ksi_sigq = NULL; 313 ksiginfo_copy(ksi, si); 314 if (ksiginfo_tryfree(ksi) && p != NULL) 315 p->p_pendingcnt--; 316 } 317 if (++count > 1) 318 break; 319 } 320 } 321 322 if (count <= 1) 323 SIGDELSET(sq->sq_signals, signo); 324 si->ksi_signo = signo; 325 return (signo); 326 } 327 328 void 329 sigqueue_take(ksiginfo_t *ksi) 330 { 331 struct ksiginfo *kp; 332 struct proc *p; 333 sigqueue_t *sq; 334 335 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 336 return; 337 338 p = sq->sq_proc; 339 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 340 ksi->ksi_sigq = NULL; 341 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 342 p->p_pendingcnt--; 343 344 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 345 kp = TAILQ_NEXT(kp, ksi_link)) { 346 if (kp->ksi_signo == ksi->ksi_signo) 347 break; 348 } 349 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 350 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 351 } 352 353 static int 354 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 355 { 356 struct proc *p = sq->sq_proc; 357 struct ksiginfo *ksi; 358 int ret = 0; 359 360 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 361 362 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 363 SIGADDSET(sq->sq_kill, signo); 364 goto out_set_bit; 365 } 366 367 /* directly insert the ksi, don't copy it */ 368 if (si->ksi_flags & KSI_INS) { 369 if (si->ksi_flags & KSI_HEAD) 370 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 371 else 372 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 373 si->ksi_sigq = sq; 374 goto out_set_bit; 375 } 376 377 if (__predict_false(ksiginfo_zone == NULL)) { 378 SIGADDSET(sq->sq_kill, signo); 379 goto out_set_bit; 380 } 381 382 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 383 signal_overflow++; 384 ret = EAGAIN; 385 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 386 signal_alloc_fail++; 387 ret = EAGAIN; 388 } else { 389 if (p != NULL) 390 p->p_pendingcnt++; 391 ksiginfo_copy(si, ksi); 392 ksi->ksi_signo = signo; 393 if (si->ksi_flags & KSI_HEAD) 394 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 395 else 396 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 397 ksi->ksi_sigq = sq; 398 } 399 400 if ((si->ksi_flags & KSI_TRAP) != 0 || 401 (si->ksi_flags & KSI_SIGQ) == 0) { 402 if (ret != 0) 403 SIGADDSET(sq->sq_kill, signo); 404 ret = 0; 405 goto out_set_bit; 406 } 407 408 if (ret != 0) 409 return (ret); 410 411 out_set_bit: 412 SIGADDSET(sq->sq_signals, signo); 413 return (ret); 414 } 415 416 void 417 sigqueue_flush(sigqueue_t *sq) 418 { 419 struct proc *p = sq->sq_proc; 420 ksiginfo_t *ksi; 421 422 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 423 424 if (p != NULL) 425 PROC_LOCK_ASSERT(p, MA_OWNED); 426 427 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 428 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 429 ksi->ksi_sigq = NULL; 430 if (ksiginfo_tryfree(ksi) && p != NULL) 431 p->p_pendingcnt--; 432 } 433 434 SIGEMPTYSET(sq->sq_signals); 435 SIGEMPTYSET(sq->sq_kill); 436 } 437 438 static void 439 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 440 { 441 sigset_t tmp; 442 struct proc *p1, *p2; 443 ksiginfo_t *ksi, *next; 444 445 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 446 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 447 p1 = src->sq_proc; 448 p2 = dst->sq_proc; 449 /* Move siginfo to target list */ 450 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 451 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 452 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 453 if (p1 != NULL) 454 p1->p_pendingcnt--; 455 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 456 ksi->ksi_sigq = dst; 457 if (p2 != NULL) 458 p2->p_pendingcnt++; 459 } 460 } 461 462 /* Move pending bits to target list */ 463 tmp = src->sq_kill; 464 SIGSETAND(tmp, *set); 465 SIGSETOR(dst->sq_kill, tmp); 466 SIGSETNAND(src->sq_kill, tmp); 467 468 tmp = src->sq_signals; 469 SIGSETAND(tmp, *set); 470 SIGSETOR(dst->sq_signals, tmp); 471 SIGSETNAND(src->sq_signals, tmp); 472 } 473 474 #if 0 475 static void 476 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 477 { 478 sigset_t set; 479 480 SIGEMPTYSET(set); 481 SIGADDSET(set, signo); 482 sigqueue_move_set(src, dst, &set); 483 } 484 #endif 485 486 static void 487 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 488 { 489 struct proc *p = sq->sq_proc; 490 ksiginfo_t *ksi, *next; 491 492 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 493 494 /* Remove siginfo queue */ 495 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 496 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 497 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 498 ksi->ksi_sigq = NULL; 499 if (ksiginfo_tryfree(ksi) && p != NULL) 500 p->p_pendingcnt--; 501 } 502 } 503 SIGSETNAND(sq->sq_kill, *set); 504 SIGSETNAND(sq->sq_signals, *set); 505 } 506 507 void 508 sigqueue_delete(sigqueue_t *sq, int signo) 509 { 510 sigset_t set; 511 512 SIGEMPTYSET(set); 513 SIGADDSET(set, signo); 514 sigqueue_delete_set(sq, &set); 515 } 516 517 /* Remove a set of signals for a process */ 518 static void 519 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 520 { 521 sigqueue_t worklist; 522 struct thread *td0; 523 524 PROC_LOCK_ASSERT(p, MA_OWNED); 525 526 sigqueue_init(&worklist, NULL); 527 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 528 529 FOREACH_THREAD_IN_PROC(p, td0) 530 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 531 532 sigqueue_flush(&worklist); 533 } 534 535 void 536 sigqueue_delete_proc(struct proc *p, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set_proc(p, &set); 543 } 544 545 static void 546 sigqueue_delete_stopmask_proc(struct proc *p) 547 { 548 sigset_t set; 549 550 SIGEMPTYSET(set); 551 SIGADDSET(set, SIGSTOP); 552 SIGADDSET(set, SIGTSTP); 553 SIGADDSET(set, SIGTTIN); 554 SIGADDSET(set, SIGTTOU); 555 sigqueue_delete_set_proc(p, &set); 556 } 557 558 /* 559 * Determine signal that should be delivered to process p, the current 560 * process, 0 if none. If there is a pending stop signal with default 561 * action, the process stops in issignal(). 562 */ 563 int 564 cursig(struct thread *td, int stop_allowed) 565 { 566 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 567 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 568 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 569 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 570 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 571 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 572 } 573 574 /* 575 * Arrange for ast() to handle unmasked pending signals on return to user 576 * mode. This must be called whenever a signal is added to td_sigqueue or 577 * unmasked in td_sigmask. 578 */ 579 void 580 signotify(struct thread *td) 581 { 582 struct proc *p; 583 584 p = td->td_proc; 585 586 PROC_LOCK_ASSERT(p, MA_OWNED); 587 588 if (SIGPENDING(td)) { 589 thread_lock(td); 590 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 591 thread_unlock(td); 592 } 593 } 594 595 int 596 sigonstack(size_t sp) 597 { 598 struct thread *td = curthread; 599 600 return ((td->td_pflags & TDP_ALTSTACK) ? 601 #if defined(COMPAT_43) 602 ((td->td_sigstk.ss_size == 0) ? 603 (td->td_sigstk.ss_flags & SS_ONSTACK) : 604 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 605 #else 606 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 607 #endif 608 : 0); 609 } 610 611 static __inline int 612 sigprop(int sig) 613 { 614 615 if (sig > 0 && sig < NSIG) 616 return (sigproptbl[_SIG_IDX(sig)]); 617 return (0); 618 } 619 620 int 621 sig_ffs(sigset_t *set) 622 { 623 int i; 624 625 for (i = 0; i < _SIG_WORDS; i++) 626 if (set->__bits[i]) 627 return (ffs(set->__bits[i]) + (i * 32)); 628 return (0); 629 } 630 631 /* 632 * kern_sigaction 633 * sigaction 634 * freebsd4_sigaction 635 * osigaction 636 */ 637 int 638 kern_sigaction(td, sig, act, oact, flags) 639 struct thread *td; 640 register int sig; 641 struct sigaction *act, *oact; 642 int flags; 643 { 644 struct sigacts *ps; 645 struct proc *p = td->td_proc; 646 647 if (!_SIG_VALID(sig)) 648 return (EINVAL); 649 650 PROC_LOCK(p); 651 ps = p->p_sigacts; 652 mtx_lock(&ps->ps_mtx); 653 if (oact) { 654 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 655 oact->sa_flags = 0; 656 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 657 oact->sa_flags |= SA_ONSTACK; 658 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 659 oact->sa_flags |= SA_RESTART; 660 if (SIGISMEMBER(ps->ps_sigreset, sig)) 661 oact->sa_flags |= SA_RESETHAND; 662 if (SIGISMEMBER(ps->ps_signodefer, sig)) 663 oact->sa_flags |= SA_NODEFER; 664 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 665 oact->sa_flags |= SA_SIGINFO; 666 oact->sa_sigaction = 667 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 668 } else 669 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 670 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 671 oact->sa_flags |= SA_NOCLDSTOP; 672 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 673 oact->sa_flags |= SA_NOCLDWAIT; 674 } 675 if (act) { 676 if ((sig == SIGKILL || sig == SIGSTOP) && 677 act->sa_handler != SIG_DFL) { 678 mtx_unlock(&ps->ps_mtx); 679 PROC_UNLOCK(p); 680 return (EINVAL); 681 } 682 683 /* 684 * Change setting atomically. 685 */ 686 687 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 688 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 689 if (act->sa_flags & SA_SIGINFO) { 690 ps->ps_sigact[_SIG_IDX(sig)] = 691 (__sighandler_t *)act->sa_sigaction; 692 SIGADDSET(ps->ps_siginfo, sig); 693 } else { 694 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 695 SIGDELSET(ps->ps_siginfo, sig); 696 } 697 if (!(act->sa_flags & SA_RESTART)) 698 SIGADDSET(ps->ps_sigintr, sig); 699 else 700 SIGDELSET(ps->ps_sigintr, sig); 701 if (act->sa_flags & SA_ONSTACK) 702 SIGADDSET(ps->ps_sigonstack, sig); 703 else 704 SIGDELSET(ps->ps_sigonstack, sig); 705 if (act->sa_flags & SA_RESETHAND) 706 SIGADDSET(ps->ps_sigreset, sig); 707 else 708 SIGDELSET(ps->ps_sigreset, sig); 709 if (act->sa_flags & SA_NODEFER) 710 SIGADDSET(ps->ps_signodefer, sig); 711 else 712 SIGDELSET(ps->ps_signodefer, sig); 713 if (sig == SIGCHLD) { 714 if (act->sa_flags & SA_NOCLDSTOP) 715 ps->ps_flag |= PS_NOCLDSTOP; 716 else 717 ps->ps_flag &= ~PS_NOCLDSTOP; 718 if (act->sa_flags & SA_NOCLDWAIT) { 719 /* 720 * Paranoia: since SA_NOCLDWAIT is implemented 721 * by reparenting the dying child to PID 1 (and 722 * trust it to reap the zombie), PID 1 itself 723 * is forbidden to set SA_NOCLDWAIT. 724 */ 725 if (p->p_pid == 1) 726 ps->ps_flag &= ~PS_NOCLDWAIT; 727 else 728 ps->ps_flag |= PS_NOCLDWAIT; 729 } else 730 ps->ps_flag &= ~PS_NOCLDWAIT; 731 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 732 ps->ps_flag |= PS_CLDSIGIGN; 733 else 734 ps->ps_flag &= ~PS_CLDSIGIGN; 735 } 736 /* 737 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 738 * and for signals set to SIG_DFL where the default is to 739 * ignore. However, don't put SIGCONT in ps_sigignore, as we 740 * have to restart the process. 741 */ 742 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 743 (sigprop(sig) & SA_IGNORE && 744 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 745 /* never to be seen again */ 746 sigqueue_delete_proc(p, sig); 747 if (sig != SIGCONT) 748 /* easier in psignal */ 749 SIGADDSET(ps->ps_sigignore, sig); 750 SIGDELSET(ps->ps_sigcatch, sig); 751 } else { 752 SIGDELSET(ps->ps_sigignore, sig); 753 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 754 SIGDELSET(ps->ps_sigcatch, sig); 755 else 756 SIGADDSET(ps->ps_sigcatch, sig); 757 } 758 #ifdef COMPAT_FREEBSD4 759 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 760 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 761 (flags & KSA_FREEBSD4) == 0) 762 SIGDELSET(ps->ps_freebsd4, sig); 763 else 764 SIGADDSET(ps->ps_freebsd4, sig); 765 #endif 766 #ifdef COMPAT_43 767 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 768 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 769 (flags & KSA_OSIGSET) == 0) 770 SIGDELSET(ps->ps_osigset, sig); 771 else 772 SIGADDSET(ps->ps_osigset, sig); 773 #endif 774 } 775 mtx_unlock(&ps->ps_mtx); 776 PROC_UNLOCK(p); 777 return (0); 778 } 779 780 #ifndef _SYS_SYSPROTO_H_ 781 struct sigaction_args { 782 int sig; 783 struct sigaction *act; 784 struct sigaction *oact; 785 }; 786 #endif 787 int 788 sys_sigaction(td, uap) 789 struct thread *td; 790 register struct sigaction_args *uap; 791 { 792 struct sigaction act, oact; 793 register struct sigaction *actp, *oactp; 794 int error; 795 796 actp = (uap->act != NULL) ? &act : NULL; 797 oactp = (uap->oact != NULL) ? &oact : NULL; 798 if (actp) { 799 error = copyin(uap->act, actp, sizeof(act)); 800 if (error) 801 return (error); 802 } 803 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 804 if (oactp && !error) 805 error = copyout(oactp, uap->oact, sizeof(oact)); 806 return (error); 807 } 808 809 #ifdef COMPAT_FREEBSD4 810 #ifndef _SYS_SYSPROTO_H_ 811 struct freebsd4_sigaction_args { 812 int sig; 813 struct sigaction *act; 814 struct sigaction *oact; 815 }; 816 #endif 817 int 818 freebsd4_sigaction(td, uap) 819 struct thread *td; 820 register struct freebsd4_sigaction_args *uap; 821 { 822 struct sigaction act, oact; 823 register struct sigaction *actp, *oactp; 824 int error; 825 826 827 actp = (uap->act != NULL) ? &act : NULL; 828 oactp = (uap->oact != NULL) ? &oact : NULL; 829 if (actp) { 830 error = copyin(uap->act, actp, sizeof(act)); 831 if (error) 832 return (error); 833 } 834 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 835 if (oactp && !error) 836 error = copyout(oactp, uap->oact, sizeof(oact)); 837 return (error); 838 } 839 #endif /* COMAPT_FREEBSD4 */ 840 841 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 842 #ifndef _SYS_SYSPROTO_H_ 843 struct osigaction_args { 844 int signum; 845 struct osigaction *nsa; 846 struct osigaction *osa; 847 }; 848 #endif 849 int 850 osigaction(td, uap) 851 struct thread *td; 852 register struct osigaction_args *uap; 853 { 854 struct osigaction sa; 855 struct sigaction nsa, osa; 856 register struct sigaction *nsap, *osap; 857 int error; 858 859 if (uap->signum <= 0 || uap->signum >= ONSIG) 860 return (EINVAL); 861 862 nsap = (uap->nsa != NULL) ? &nsa : NULL; 863 osap = (uap->osa != NULL) ? &osa : NULL; 864 865 if (nsap) { 866 error = copyin(uap->nsa, &sa, sizeof(sa)); 867 if (error) 868 return (error); 869 nsap->sa_handler = sa.sa_handler; 870 nsap->sa_flags = sa.sa_flags; 871 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 872 } 873 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 874 if (osap && !error) { 875 sa.sa_handler = osap->sa_handler; 876 sa.sa_flags = osap->sa_flags; 877 SIG2OSIG(osap->sa_mask, sa.sa_mask); 878 error = copyout(&sa, uap->osa, sizeof(sa)); 879 } 880 return (error); 881 } 882 883 #if !defined(__i386__) 884 /* Avoid replicating the same stub everywhere */ 885 int 886 osigreturn(td, uap) 887 struct thread *td; 888 struct osigreturn_args *uap; 889 { 890 891 return (nosys(td, (struct nosys_args *)uap)); 892 } 893 #endif 894 #endif /* COMPAT_43 */ 895 896 /* 897 * Initialize signal state for process 0; 898 * set to ignore signals that are ignored by default. 899 */ 900 void 901 siginit(p) 902 struct proc *p; 903 { 904 register int i; 905 struct sigacts *ps; 906 907 PROC_LOCK(p); 908 ps = p->p_sigacts; 909 mtx_lock(&ps->ps_mtx); 910 for (i = 1; i <= NSIG; i++) 911 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 912 SIGADDSET(ps->ps_sigignore, i); 913 mtx_unlock(&ps->ps_mtx); 914 PROC_UNLOCK(p); 915 } 916 917 /* 918 * Reset signals for an exec of the specified process. 919 */ 920 void 921 execsigs(struct proc *p) 922 { 923 struct sigacts *ps; 924 int sig; 925 struct thread *td; 926 927 /* 928 * Reset caught signals. Held signals remain held 929 * through td_sigmask (unless they were caught, 930 * and are now ignored by default). 931 */ 932 PROC_LOCK_ASSERT(p, MA_OWNED); 933 td = FIRST_THREAD_IN_PROC(p); 934 ps = p->p_sigacts; 935 mtx_lock(&ps->ps_mtx); 936 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 937 sig = sig_ffs(&ps->ps_sigcatch); 938 SIGDELSET(ps->ps_sigcatch, sig); 939 if (sigprop(sig) & SA_IGNORE) { 940 if (sig != SIGCONT) 941 SIGADDSET(ps->ps_sigignore, sig); 942 sigqueue_delete_proc(p, sig); 943 } 944 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 945 } 946 /* 947 * Reset stack state to the user stack. 948 * Clear set of signals caught on the signal stack. 949 */ 950 td->td_sigstk.ss_flags = SS_DISABLE; 951 td->td_sigstk.ss_size = 0; 952 td->td_sigstk.ss_sp = 0; 953 td->td_pflags &= ~TDP_ALTSTACK; 954 /* 955 * Reset no zombies if child dies flag as Solaris does. 956 */ 957 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 958 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 959 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 960 mtx_unlock(&ps->ps_mtx); 961 } 962 963 /* 964 * kern_sigprocmask() 965 * 966 * Manipulate signal mask. 967 */ 968 int 969 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 970 int flags) 971 { 972 sigset_t new_block, oset1; 973 struct proc *p; 974 int error; 975 976 p = td->td_proc; 977 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 978 PROC_LOCK(p); 979 if (oset != NULL) 980 *oset = td->td_sigmask; 981 982 error = 0; 983 if (set != NULL) { 984 switch (how) { 985 case SIG_BLOCK: 986 SIG_CANTMASK(*set); 987 oset1 = td->td_sigmask; 988 SIGSETOR(td->td_sigmask, *set); 989 new_block = td->td_sigmask; 990 SIGSETNAND(new_block, oset1); 991 break; 992 case SIG_UNBLOCK: 993 SIGSETNAND(td->td_sigmask, *set); 994 signotify(td); 995 goto out; 996 case SIG_SETMASK: 997 SIG_CANTMASK(*set); 998 oset1 = td->td_sigmask; 999 if (flags & SIGPROCMASK_OLD) 1000 SIGSETLO(td->td_sigmask, *set); 1001 else 1002 td->td_sigmask = *set; 1003 new_block = td->td_sigmask; 1004 SIGSETNAND(new_block, oset1); 1005 signotify(td); 1006 break; 1007 default: 1008 error = EINVAL; 1009 goto out; 1010 } 1011 1012 /* 1013 * The new_block set contains signals that were not previously 1014 * blocked, but are blocked now. 1015 * 1016 * In case we block any signal that was not previously blocked 1017 * for td, and process has the signal pending, try to schedule 1018 * signal delivery to some thread that does not block the 1019 * signal, possibly waking it up. 1020 */ 1021 if (p->p_numthreads != 1) 1022 reschedule_signals(p, new_block, flags); 1023 } 1024 1025 out: 1026 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1027 PROC_UNLOCK(p); 1028 return (error); 1029 } 1030 1031 #ifndef _SYS_SYSPROTO_H_ 1032 struct sigprocmask_args { 1033 int how; 1034 const sigset_t *set; 1035 sigset_t *oset; 1036 }; 1037 #endif 1038 int 1039 sys_sigprocmask(td, uap) 1040 register struct thread *td; 1041 struct sigprocmask_args *uap; 1042 { 1043 sigset_t set, oset; 1044 sigset_t *setp, *osetp; 1045 int error; 1046 1047 setp = (uap->set != NULL) ? &set : NULL; 1048 osetp = (uap->oset != NULL) ? &oset : NULL; 1049 if (setp) { 1050 error = copyin(uap->set, setp, sizeof(set)); 1051 if (error) 1052 return (error); 1053 } 1054 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1055 if (osetp && !error) { 1056 error = copyout(osetp, uap->oset, sizeof(oset)); 1057 } 1058 return (error); 1059 } 1060 1061 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1062 #ifndef _SYS_SYSPROTO_H_ 1063 struct osigprocmask_args { 1064 int how; 1065 osigset_t mask; 1066 }; 1067 #endif 1068 int 1069 osigprocmask(td, uap) 1070 register struct thread *td; 1071 struct osigprocmask_args *uap; 1072 { 1073 sigset_t set, oset; 1074 int error; 1075 1076 OSIG2SIG(uap->mask, set); 1077 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1078 SIG2OSIG(oset, td->td_retval[0]); 1079 return (error); 1080 } 1081 #endif /* COMPAT_43 */ 1082 1083 int 1084 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1085 { 1086 ksiginfo_t ksi; 1087 sigset_t set; 1088 int error; 1089 1090 error = copyin(uap->set, &set, sizeof(set)); 1091 if (error) { 1092 td->td_retval[0] = error; 1093 return (0); 1094 } 1095 1096 error = kern_sigtimedwait(td, set, &ksi, NULL); 1097 if (error) { 1098 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1099 error = ERESTART; 1100 if (error == ERESTART) 1101 return (error); 1102 td->td_retval[0] = error; 1103 return (0); 1104 } 1105 1106 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1107 td->td_retval[0] = error; 1108 return (0); 1109 } 1110 1111 int 1112 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1113 { 1114 struct timespec ts; 1115 struct timespec *timeout; 1116 sigset_t set; 1117 ksiginfo_t ksi; 1118 int error; 1119 1120 if (uap->timeout) { 1121 error = copyin(uap->timeout, &ts, sizeof(ts)); 1122 if (error) 1123 return (error); 1124 1125 timeout = &ts; 1126 } else 1127 timeout = NULL; 1128 1129 error = copyin(uap->set, &set, sizeof(set)); 1130 if (error) 1131 return (error); 1132 1133 error = kern_sigtimedwait(td, set, &ksi, timeout); 1134 if (error) 1135 return (error); 1136 1137 if (uap->info) 1138 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1139 1140 if (error == 0) 1141 td->td_retval[0] = ksi.ksi_signo; 1142 return (error); 1143 } 1144 1145 int 1146 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1147 { 1148 ksiginfo_t ksi; 1149 sigset_t set; 1150 int error; 1151 1152 error = copyin(uap->set, &set, sizeof(set)); 1153 if (error) 1154 return (error); 1155 1156 error = kern_sigtimedwait(td, set, &ksi, NULL); 1157 if (error) 1158 return (error); 1159 1160 if (uap->info) 1161 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1162 1163 if (error == 0) 1164 td->td_retval[0] = ksi.ksi_signo; 1165 return (error); 1166 } 1167 1168 int 1169 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1170 struct timespec *timeout) 1171 { 1172 struct sigacts *ps; 1173 sigset_t saved_mask, new_block; 1174 struct proc *p; 1175 int error, sig, timo, timevalid = 0; 1176 struct timespec rts, ets, ts; 1177 struct timeval tv; 1178 1179 p = td->td_proc; 1180 error = 0; 1181 ets.tv_sec = 0; 1182 ets.tv_nsec = 0; 1183 1184 if (timeout != NULL) { 1185 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1186 timevalid = 1; 1187 getnanouptime(&rts); 1188 ets = rts; 1189 timespecadd(&ets, timeout); 1190 } 1191 } 1192 ksiginfo_init(ksi); 1193 /* Some signals can not be waited for. */ 1194 SIG_CANTMASK(waitset); 1195 ps = p->p_sigacts; 1196 PROC_LOCK(p); 1197 saved_mask = td->td_sigmask; 1198 SIGSETNAND(td->td_sigmask, waitset); 1199 for (;;) { 1200 mtx_lock(&ps->ps_mtx); 1201 sig = cursig(td, SIG_STOP_ALLOWED); 1202 mtx_unlock(&ps->ps_mtx); 1203 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1204 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1205 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1206 error = 0; 1207 break; 1208 } 1209 } 1210 1211 if (error != 0) 1212 break; 1213 1214 /* 1215 * POSIX says this must be checked after looking for pending 1216 * signals. 1217 */ 1218 if (timeout != NULL) { 1219 if (!timevalid) { 1220 error = EINVAL; 1221 break; 1222 } 1223 getnanouptime(&rts); 1224 if (timespeccmp(&rts, &ets, >=)) { 1225 error = EAGAIN; 1226 break; 1227 } 1228 ts = ets; 1229 timespecsub(&ts, &rts); 1230 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1231 timo = tvtohz(&tv); 1232 } else { 1233 timo = 0; 1234 } 1235 1236 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1237 1238 if (timeout != NULL) { 1239 if (error == ERESTART) { 1240 /* Timeout can not be restarted. */ 1241 error = EINTR; 1242 } else if (error == EAGAIN) { 1243 /* We will calculate timeout by ourself. */ 1244 error = 0; 1245 } 1246 } 1247 } 1248 1249 new_block = saved_mask; 1250 SIGSETNAND(new_block, td->td_sigmask); 1251 td->td_sigmask = saved_mask; 1252 /* 1253 * Fewer signals can be delivered to us, reschedule signal 1254 * notification. 1255 */ 1256 if (p->p_numthreads != 1) 1257 reschedule_signals(p, new_block, 0); 1258 1259 if (error == 0) { 1260 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1261 1262 if (ksi->ksi_code == SI_TIMER) 1263 itimer_accept(p, ksi->ksi_timerid, ksi); 1264 1265 #ifdef KTRACE 1266 if (KTRPOINT(td, KTR_PSIG)) { 1267 sig_t action; 1268 1269 mtx_lock(&ps->ps_mtx); 1270 action = ps->ps_sigact[_SIG_IDX(sig)]; 1271 mtx_unlock(&ps->ps_mtx); 1272 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1273 } 1274 #endif 1275 if (sig == SIGKILL) 1276 sigexit(td, sig); 1277 } 1278 PROC_UNLOCK(p); 1279 return (error); 1280 } 1281 1282 #ifndef _SYS_SYSPROTO_H_ 1283 struct sigpending_args { 1284 sigset_t *set; 1285 }; 1286 #endif 1287 int 1288 sys_sigpending(td, uap) 1289 struct thread *td; 1290 struct sigpending_args *uap; 1291 { 1292 struct proc *p = td->td_proc; 1293 sigset_t pending; 1294 1295 PROC_LOCK(p); 1296 pending = p->p_sigqueue.sq_signals; 1297 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1298 PROC_UNLOCK(p); 1299 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1300 } 1301 1302 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1303 #ifndef _SYS_SYSPROTO_H_ 1304 struct osigpending_args { 1305 int dummy; 1306 }; 1307 #endif 1308 int 1309 osigpending(td, uap) 1310 struct thread *td; 1311 struct osigpending_args *uap; 1312 { 1313 struct proc *p = td->td_proc; 1314 sigset_t pending; 1315 1316 PROC_LOCK(p); 1317 pending = p->p_sigqueue.sq_signals; 1318 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1319 PROC_UNLOCK(p); 1320 SIG2OSIG(pending, td->td_retval[0]); 1321 return (0); 1322 } 1323 #endif /* COMPAT_43 */ 1324 1325 #if defined(COMPAT_43) 1326 /* 1327 * Generalized interface signal handler, 4.3-compatible. 1328 */ 1329 #ifndef _SYS_SYSPROTO_H_ 1330 struct osigvec_args { 1331 int signum; 1332 struct sigvec *nsv; 1333 struct sigvec *osv; 1334 }; 1335 #endif 1336 /* ARGSUSED */ 1337 int 1338 osigvec(td, uap) 1339 struct thread *td; 1340 register struct osigvec_args *uap; 1341 { 1342 struct sigvec vec; 1343 struct sigaction nsa, osa; 1344 register struct sigaction *nsap, *osap; 1345 int error; 1346 1347 if (uap->signum <= 0 || uap->signum >= ONSIG) 1348 return (EINVAL); 1349 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1350 osap = (uap->osv != NULL) ? &osa : NULL; 1351 if (nsap) { 1352 error = copyin(uap->nsv, &vec, sizeof(vec)); 1353 if (error) 1354 return (error); 1355 nsap->sa_handler = vec.sv_handler; 1356 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1357 nsap->sa_flags = vec.sv_flags; 1358 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1359 } 1360 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1361 if (osap && !error) { 1362 vec.sv_handler = osap->sa_handler; 1363 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1364 vec.sv_flags = osap->sa_flags; 1365 vec.sv_flags &= ~SA_NOCLDWAIT; 1366 vec.sv_flags ^= SA_RESTART; 1367 error = copyout(&vec, uap->osv, sizeof(vec)); 1368 } 1369 return (error); 1370 } 1371 1372 #ifndef _SYS_SYSPROTO_H_ 1373 struct osigblock_args { 1374 int mask; 1375 }; 1376 #endif 1377 int 1378 osigblock(td, uap) 1379 register struct thread *td; 1380 struct osigblock_args *uap; 1381 { 1382 sigset_t set, oset; 1383 1384 OSIG2SIG(uap->mask, set); 1385 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1386 SIG2OSIG(oset, td->td_retval[0]); 1387 return (0); 1388 } 1389 1390 #ifndef _SYS_SYSPROTO_H_ 1391 struct osigsetmask_args { 1392 int mask; 1393 }; 1394 #endif 1395 int 1396 osigsetmask(td, uap) 1397 struct thread *td; 1398 struct osigsetmask_args *uap; 1399 { 1400 sigset_t set, oset; 1401 1402 OSIG2SIG(uap->mask, set); 1403 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1404 SIG2OSIG(oset, td->td_retval[0]); 1405 return (0); 1406 } 1407 #endif /* COMPAT_43 */ 1408 1409 /* 1410 * Suspend calling thread until signal, providing mask to be set in the 1411 * meantime. 1412 */ 1413 #ifndef _SYS_SYSPROTO_H_ 1414 struct sigsuspend_args { 1415 const sigset_t *sigmask; 1416 }; 1417 #endif 1418 /* ARGSUSED */ 1419 int 1420 sys_sigsuspend(td, uap) 1421 struct thread *td; 1422 struct sigsuspend_args *uap; 1423 { 1424 sigset_t mask; 1425 int error; 1426 1427 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1428 if (error) 1429 return (error); 1430 return (kern_sigsuspend(td, mask)); 1431 } 1432 1433 int 1434 kern_sigsuspend(struct thread *td, sigset_t mask) 1435 { 1436 struct proc *p = td->td_proc; 1437 int has_sig, sig; 1438 1439 /* 1440 * When returning from sigsuspend, we want 1441 * the old mask to be restored after the 1442 * signal handler has finished. Thus, we 1443 * save it here and mark the sigacts structure 1444 * to indicate this. 1445 */ 1446 PROC_LOCK(p); 1447 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1448 SIGPROCMASK_PROC_LOCKED); 1449 td->td_pflags |= TDP_OLDMASK; 1450 1451 /* 1452 * Process signals now. Otherwise, we can get spurious wakeup 1453 * due to signal entered process queue, but delivered to other 1454 * thread. But sigsuspend should return only on signal 1455 * delivery. 1456 */ 1457 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1458 for (has_sig = 0; !has_sig;) { 1459 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1460 0) == 0) 1461 /* void */; 1462 thread_suspend_check(0); 1463 mtx_lock(&p->p_sigacts->ps_mtx); 1464 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1465 has_sig += postsig(sig); 1466 mtx_unlock(&p->p_sigacts->ps_mtx); 1467 } 1468 PROC_UNLOCK(p); 1469 return (EJUSTRETURN); 1470 } 1471 1472 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1473 /* 1474 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1475 * convention: libc stub passes mask, not pointer, to save a copyin. 1476 */ 1477 #ifndef _SYS_SYSPROTO_H_ 1478 struct osigsuspend_args { 1479 osigset_t mask; 1480 }; 1481 #endif 1482 /* ARGSUSED */ 1483 int 1484 osigsuspend(td, uap) 1485 struct thread *td; 1486 struct osigsuspend_args *uap; 1487 { 1488 sigset_t mask; 1489 1490 OSIG2SIG(uap->mask, mask); 1491 return (kern_sigsuspend(td, mask)); 1492 } 1493 #endif /* COMPAT_43 */ 1494 1495 #if defined(COMPAT_43) 1496 #ifndef _SYS_SYSPROTO_H_ 1497 struct osigstack_args { 1498 struct sigstack *nss; 1499 struct sigstack *oss; 1500 }; 1501 #endif 1502 /* ARGSUSED */ 1503 int 1504 osigstack(td, uap) 1505 struct thread *td; 1506 register struct osigstack_args *uap; 1507 { 1508 struct sigstack nss, oss; 1509 int error = 0; 1510 1511 if (uap->nss != NULL) { 1512 error = copyin(uap->nss, &nss, sizeof(nss)); 1513 if (error) 1514 return (error); 1515 } 1516 oss.ss_sp = td->td_sigstk.ss_sp; 1517 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1518 if (uap->nss != NULL) { 1519 td->td_sigstk.ss_sp = nss.ss_sp; 1520 td->td_sigstk.ss_size = 0; 1521 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1522 td->td_pflags |= TDP_ALTSTACK; 1523 } 1524 if (uap->oss != NULL) 1525 error = copyout(&oss, uap->oss, sizeof(oss)); 1526 1527 return (error); 1528 } 1529 #endif /* COMPAT_43 */ 1530 1531 #ifndef _SYS_SYSPROTO_H_ 1532 struct sigaltstack_args { 1533 stack_t *ss; 1534 stack_t *oss; 1535 }; 1536 #endif 1537 /* ARGSUSED */ 1538 int 1539 sys_sigaltstack(td, uap) 1540 struct thread *td; 1541 register struct sigaltstack_args *uap; 1542 { 1543 stack_t ss, oss; 1544 int error; 1545 1546 if (uap->ss != NULL) { 1547 error = copyin(uap->ss, &ss, sizeof(ss)); 1548 if (error) 1549 return (error); 1550 } 1551 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1552 (uap->oss != NULL) ? &oss : NULL); 1553 if (error) 1554 return (error); 1555 if (uap->oss != NULL) 1556 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1557 return (error); 1558 } 1559 1560 int 1561 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1562 { 1563 struct proc *p = td->td_proc; 1564 int oonstack; 1565 1566 oonstack = sigonstack(cpu_getstack(td)); 1567 1568 if (oss != NULL) { 1569 *oss = td->td_sigstk; 1570 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1571 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1572 } 1573 1574 if (ss != NULL) { 1575 if (oonstack) 1576 return (EPERM); 1577 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1578 return (EINVAL); 1579 if (!(ss->ss_flags & SS_DISABLE)) { 1580 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1581 return (ENOMEM); 1582 1583 td->td_sigstk = *ss; 1584 td->td_pflags |= TDP_ALTSTACK; 1585 } else { 1586 td->td_pflags &= ~TDP_ALTSTACK; 1587 } 1588 } 1589 return (0); 1590 } 1591 1592 /* 1593 * Common code for kill process group/broadcast kill. 1594 * cp is calling process. 1595 */ 1596 static int 1597 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1598 { 1599 struct proc *p; 1600 struct pgrp *pgrp; 1601 int nfound = 0; 1602 1603 if (all) { 1604 /* 1605 * broadcast 1606 */ 1607 sx_slock(&allproc_lock); 1608 FOREACH_PROC_IN_SYSTEM(p) { 1609 PROC_LOCK(p); 1610 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1611 p == td->td_proc || p->p_state == PRS_NEW) { 1612 PROC_UNLOCK(p); 1613 continue; 1614 } 1615 if (p_cansignal(td, p, sig) == 0) { 1616 nfound++; 1617 if (sig) 1618 pksignal(p, sig, ksi); 1619 } 1620 PROC_UNLOCK(p); 1621 } 1622 sx_sunlock(&allproc_lock); 1623 } else { 1624 sx_slock(&proctree_lock); 1625 if (pgid == 0) { 1626 /* 1627 * zero pgid means send to my process group. 1628 */ 1629 pgrp = td->td_proc->p_pgrp; 1630 PGRP_LOCK(pgrp); 1631 } else { 1632 pgrp = pgfind(pgid); 1633 if (pgrp == NULL) { 1634 sx_sunlock(&proctree_lock); 1635 return (ESRCH); 1636 } 1637 } 1638 sx_sunlock(&proctree_lock); 1639 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1640 PROC_LOCK(p); 1641 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1642 p->p_state == PRS_NEW) { 1643 PROC_UNLOCK(p); 1644 continue; 1645 } 1646 if (p_cansignal(td, p, sig) == 0) { 1647 nfound++; 1648 if (sig) 1649 pksignal(p, sig, ksi); 1650 } 1651 PROC_UNLOCK(p); 1652 } 1653 PGRP_UNLOCK(pgrp); 1654 } 1655 return (nfound ? 0 : ESRCH); 1656 } 1657 1658 #ifndef _SYS_SYSPROTO_H_ 1659 struct kill_args { 1660 int pid; 1661 int signum; 1662 }; 1663 #endif 1664 /* ARGSUSED */ 1665 int 1666 sys_kill(struct thread *td, struct kill_args *uap) 1667 { 1668 ksiginfo_t ksi; 1669 struct proc *p; 1670 int error; 1671 1672 AUDIT_ARG_SIGNUM(uap->signum); 1673 AUDIT_ARG_PID(uap->pid); 1674 if ((u_int)uap->signum > _SIG_MAXSIG) 1675 return (EINVAL); 1676 1677 ksiginfo_init(&ksi); 1678 ksi.ksi_signo = uap->signum; 1679 ksi.ksi_code = SI_USER; 1680 ksi.ksi_pid = td->td_proc->p_pid; 1681 ksi.ksi_uid = td->td_ucred->cr_ruid; 1682 1683 if (uap->pid > 0) { 1684 /* kill single process */ 1685 if ((p = pfind(uap->pid)) == NULL) { 1686 if ((p = zpfind(uap->pid)) == NULL) 1687 return (ESRCH); 1688 } 1689 AUDIT_ARG_PROCESS(p); 1690 error = p_cansignal(td, p, uap->signum); 1691 if (error == 0 && uap->signum) 1692 pksignal(p, uap->signum, &ksi); 1693 PROC_UNLOCK(p); 1694 return (error); 1695 } 1696 switch (uap->pid) { 1697 case -1: /* broadcast signal */ 1698 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1699 case 0: /* signal own process group */ 1700 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1701 default: /* negative explicit process group */ 1702 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1703 } 1704 /* NOTREACHED */ 1705 } 1706 1707 int 1708 sys_pdkill(td, uap) 1709 struct thread *td; 1710 struct pdkill_args *uap; 1711 { 1712 #ifdef PROCDESC 1713 struct proc *p; 1714 int error; 1715 1716 AUDIT_ARG_SIGNUM(uap->signum); 1717 AUDIT_ARG_FD(uap->fd); 1718 if ((u_int)uap->signum > _SIG_MAXSIG) 1719 return (EINVAL); 1720 1721 error = procdesc_find(td, uap->fd, CAP_PDKILL, &p); 1722 if (error) 1723 return (error); 1724 AUDIT_ARG_PROCESS(p); 1725 error = p_cansignal(td, p, uap->signum); 1726 if (error == 0 && uap->signum) 1727 kern_psignal(p, uap->signum); 1728 PROC_UNLOCK(p); 1729 return (error); 1730 #else 1731 return (ENOSYS); 1732 #endif 1733 } 1734 1735 #if defined(COMPAT_43) 1736 #ifndef _SYS_SYSPROTO_H_ 1737 struct okillpg_args { 1738 int pgid; 1739 int signum; 1740 }; 1741 #endif 1742 /* ARGSUSED */ 1743 int 1744 okillpg(struct thread *td, struct okillpg_args *uap) 1745 { 1746 ksiginfo_t ksi; 1747 1748 AUDIT_ARG_SIGNUM(uap->signum); 1749 AUDIT_ARG_PID(uap->pgid); 1750 if ((u_int)uap->signum > _SIG_MAXSIG) 1751 return (EINVAL); 1752 1753 ksiginfo_init(&ksi); 1754 ksi.ksi_signo = uap->signum; 1755 ksi.ksi_code = SI_USER; 1756 ksi.ksi_pid = td->td_proc->p_pid; 1757 ksi.ksi_uid = td->td_ucred->cr_ruid; 1758 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1759 } 1760 #endif /* COMPAT_43 */ 1761 1762 #ifndef _SYS_SYSPROTO_H_ 1763 struct sigqueue_args { 1764 pid_t pid; 1765 int signum; 1766 /* union sigval */ void *value; 1767 }; 1768 #endif 1769 int 1770 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1771 { 1772 ksiginfo_t ksi; 1773 struct proc *p; 1774 int error; 1775 1776 if ((u_int)uap->signum > _SIG_MAXSIG) 1777 return (EINVAL); 1778 1779 /* 1780 * Specification says sigqueue can only send signal to 1781 * single process. 1782 */ 1783 if (uap->pid <= 0) 1784 return (EINVAL); 1785 1786 if ((p = pfind(uap->pid)) == NULL) { 1787 if ((p = zpfind(uap->pid)) == NULL) 1788 return (ESRCH); 1789 } 1790 error = p_cansignal(td, p, uap->signum); 1791 if (error == 0 && uap->signum != 0) { 1792 ksiginfo_init(&ksi); 1793 ksi.ksi_flags = KSI_SIGQ; 1794 ksi.ksi_signo = uap->signum; 1795 ksi.ksi_code = SI_QUEUE; 1796 ksi.ksi_pid = td->td_proc->p_pid; 1797 ksi.ksi_uid = td->td_ucred->cr_ruid; 1798 ksi.ksi_value.sival_ptr = uap->value; 1799 error = pksignal(p, ksi.ksi_signo, &ksi); 1800 } 1801 PROC_UNLOCK(p); 1802 return (error); 1803 } 1804 1805 /* 1806 * Send a signal to a process group. 1807 */ 1808 void 1809 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1810 { 1811 struct pgrp *pgrp; 1812 1813 if (pgid != 0) { 1814 sx_slock(&proctree_lock); 1815 pgrp = pgfind(pgid); 1816 sx_sunlock(&proctree_lock); 1817 if (pgrp != NULL) { 1818 pgsignal(pgrp, sig, 0, ksi); 1819 PGRP_UNLOCK(pgrp); 1820 } 1821 } 1822 } 1823 1824 /* 1825 * Send a signal to a process group. If checktty is 1, 1826 * limit to members which have a controlling terminal. 1827 */ 1828 void 1829 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1830 { 1831 struct proc *p; 1832 1833 if (pgrp) { 1834 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1835 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1836 PROC_LOCK(p); 1837 if (p->p_state == PRS_NORMAL && 1838 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1839 pksignal(p, sig, ksi); 1840 PROC_UNLOCK(p); 1841 } 1842 } 1843 } 1844 1845 /* 1846 * Send a signal caused by a trap to the current thread. If it will be 1847 * caught immediately, deliver it with correct code. Otherwise, post it 1848 * normally. 1849 */ 1850 void 1851 trapsignal(struct thread *td, ksiginfo_t *ksi) 1852 { 1853 struct sigacts *ps; 1854 sigset_t mask; 1855 struct proc *p; 1856 int sig; 1857 int code; 1858 1859 p = td->td_proc; 1860 sig = ksi->ksi_signo; 1861 code = ksi->ksi_code; 1862 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1863 1864 PROC_LOCK(p); 1865 ps = p->p_sigacts; 1866 mtx_lock(&ps->ps_mtx); 1867 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1868 !SIGISMEMBER(td->td_sigmask, sig)) { 1869 td->td_ru.ru_nsignals++; 1870 #ifdef KTRACE 1871 if (KTRPOINT(curthread, KTR_PSIG)) 1872 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1873 &td->td_sigmask, code); 1874 #endif 1875 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1876 ksi, &td->td_sigmask); 1877 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1878 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1879 SIGADDSET(mask, sig); 1880 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1881 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1882 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1883 /* 1884 * See kern_sigaction() for origin of this code. 1885 */ 1886 SIGDELSET(ps->ps_sigcatch, sig); 1887 if (sig != SIGCONT && 1888 sigprop(sig) & SA_IGNORE) 1889 SIGADDSET(ps->ps_sigignore, sig); 1890 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1891 } 1892 mtx_unlock(&ps->ps_mtx); 1893 } else { 1894 /* 1895 * Avoid a possible infinite loop if the thread 1896 * masking the signal or process is ignoring the 1897 * signal. 1898 */ 1899 if (kern_forcesigexit && 1900 (SIGISMEMBER(td->td_sigmask, sig) || 1901 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1902 SIGDELSET(td->td_sigmask, sig); 1903 SIGDELSET(ps->ps_sigcatch, sig); 1904 SIGDELSET(ps->ps_sigignore, sig); 1905 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1906 } 1907 mtx_unlock(&ps->ps_mtx); 1908 p->p_code = code; /* XXX for core dump/debugger */ 1909 p->p_sig = sig; /* XXX to verify code */ 1910 tdsendsignal(p, td, sig, ksi); 1911 } 1912 PROC_UNLOCK(p); 1913 } 1914 1915 static struct thread * 1916 sigtd(struct proc *p, int sig, int prop) 1917 { 1918 struct thread *td, *signal_td; 1919 1920 PROC_LOCK_ASSERT(p, MA_OWNED); 1921 1922 /* 1923 * Check if current thread can handle the signal without 1924 * switching context to another thread. 1925 */ 1926 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1927 return (curthread); 1928 signal_td = NULL; 1929 FOREACH_THREAD_IN_PROC(p, td) { 1930 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1931 signal_td = td; 1932 break; 1933 } 1934 } 1935 if (signal_td == NULL) 1936 signal_td = FIRST_THREAD_IN_PROC(p); 1937 return (signal_td); 1938 } 1939 1940 /* 1941 * Send the signal to the process. If the signal has an action, the action 1942 * is usually performed by the target process rather than the caller; we add 1943 * the signal to the set of pending signals for the process. 1944 * 1945 * Exceptions: 1946 * o When a stop signal is sent to a sleeping process that takes the 1947 * default action, the process is stopped without awakening it. 1948 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1949 * regardless of the signal action (eg, blocked or ignored). 1950 * 1951 * Other ignored signals are discarded immediately. 1952 * 1953 * NB: This function may be entered from the debugger via the "kill" DDB 1954 * command. There is little that can be done to mitigate the possibly messy 1955 * side effects of this unwise possibility. 1956 */ 1957 void 1958 kern_psignal(struct proc *p, 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(p, NULL, sig, &ksi); 1966 } 1967 1968 int 1969 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1970 { 1971 1972 return (tdsendsignal(p, NULL, sig, ksi)); 1973 } 1974 1975 /* Utility function for finding a thread to send signal event to. */ 1976 int 1977 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1978 { 1979 struct thread *td; 1980 1981 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1982 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 1983 if (td == NULL) 1984 return (ESRCH); 1985 *ttd = td; 1986 } else { 1987 *ttd = NULL; 1988 PROC_LOCK(p); 1989 } 1990 return (0); 1991 } 1992 1993 void 1994 tdsignal(struct thread *td, int sig) 1995 { 1996 ksiginfo_t ksi; 1997 1998 ksiginfo_init(&ksi); 1999 ksi.ksi_signo = sig; 2000 ksi.ksi_code = SI_KERNEL; 2001 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2002 } 2003 2004 void 2005 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2006 { 2007 2008 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2009 } 2010 2011 int 2012 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2013 { 2014 sig_t action; 2015 sigqueue_t *sigqueue; 2016 int prop; 2017 struct sigacts *ps; 2018 int intrval; 2019 int ret = 0; 2020 int wakeup_swapper; 2021 2022 MPASS(td == NULL || p == td->td_proc); 2023 PROC_LOCK_ASSERT(p, MA_OWNED); 2024 2025 if (!_SIG_VALID(sig)) 2026 panic("%s(): invalid signal %d", __func__, sig); 2027 2028 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2029 2030 /* 2031 * IEEE Std 1003.1-2001: return success when killing a zombie. 2032 */ 2033 if (p->p_state == PRS_ZOMBIE) { 2034 if (ksi && (ksi->ksi_flags & KSI_INS)) 2035 ksiginfo_tryfree(ksi); 2036 return (ret); 2037 } 2038 2039 ps = p->p_sigacts; 2040 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2041 prop = sigprop(sig); 2042 2043 if (td == NULL) { 2044 td = sigtd(p, sig, prop); 2045 sigqueue = &p->p_sigqueue; 2046 } else { 2047 KASSERT(td->td_proc == p, ("invalid thread")); 2048 sigqueue = &td->td_sigqueue; 2049 } 2050 2051 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2052 2053 /* 2054 * If the signal is being ignored, 2055 * then we forget about it immediately. 2056 * (Note: we don't set SIGCONT in ps_sigignore, 2057 * and if it is set to SIG_IGN, 2058 * action will be SIG_DFL here.) 2059 */ 2060 mtx_lock(&ps->ps_mtx); 2061 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2062 SDT_PROBE(proc, kernel, , signal_discard, td, p, sig, 0, 0 ); 2063 2064 mtx_unlock(&ps->ps_mtx); 2065 if (ksi && (ksi->ksi_flags & KSI_INS)) 2066 ksiginfo_tryfree(ksi); 2067 return (ret); 2068 } 2069 if (SIGISMEMBER(td->td_sigmask, sig)) 2070 action = SIG_HOLD; 2071 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2072 action = SIG_CATCH; 2073 else 2074 action = SIG_DFL; 2075 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2076 intrval = EINTR; 2077 else 2078 intrval = ERESTART; 2079 mtx_unlock(&ps->ps_mtx); 2080 2081 if (prop & SA_CONT) 2082 sigqueue_delete_stopmask_proc(p); 2083 else if (prop & SA_STOP) { 2084 /* 2085 * If sending a tty stop signal to a member of an orphaned 2086 * process group, discard the signal here if the action 2087 * is default; don't stop the process below if sleeping, 2088 * and don't clear any pending SIGCONT. 2089 */ 2090 if ((prop & SA_TTYSTOP) && 2091 (p->p_pgrp->pg_jobc == 0) && 2092 (action == SIG_DFL)) { 2093 if (ksi && (ksi->ksi_flags & KSI_INS)) 2094 ksiginfo_tryfree(ksi); 2095 return (ret); 2096 } 2097 sigqueue_delete_proc(p, SIGCONT); 2098 if (p->p_flag & P_CONTINUED) { 2099 p->p_flag &= ~P_CONTINUED; 2100 PROC_LOCK(p->p_pptr); 2101 sigqueue_take(p->p_ksi); 2102 PROC_UNLOCK(p->p_pptr); 2103 } 2104 } 2105 2106 ret = sigqueue_add(sigqueue, sig, ksi); 2107 if (ret != 0) 2108 return (ret); 2109 signotify(td); 2110 /* 2111 * Defer further processing for signals which are held, 2112 * except that stopped processes must be continued by SIGCONT. 2113 */ 2114 if (action == SIG_HOLD && 2115 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2116 return (ret); 2117 /* 2118 * SIGKILL: Remove procfs STOPEVENTs. 2119 */ 2120 if (sig == SIGKILL) { 2121 /* from procfs_ioctl.c: PIOCBIC */ 2122 p->p_stops = 0; 2123 /* from procfs_ioctl.c: PIOCCONT */ 2124 p->p_step = 0; 2125 wakeup(&p->p_step); 2126 } 2127 /* 2128 * Some signals have a process-wide effect and a per-thread 2129 * component. Most processing occurs when the process next 2130 * tries to cross the user boundary, however there are some 2131 * times when processing needs to be done immediatly, such as 2132 * waking up threads so that they can cross the user boundary. 2133 * We try do the per-process part here. 2134 */ 2135 if (P_SHOULDSTOP(p)) { 2136 if (sig == SIGKILL) { 2137 /* 2138 * If traced process is already stopped, 2139 * then no further action is necessary. 2140 */ 2141 if (p->p_flag & P_TRACED) 2142 goto out; 2143 /* 2144 * SIGKILL sets process running. 2145 * It will die elsewhere. 2146 * All threads must be restarted. 2147 */ 2148 p->p_flag &= ~P_STOPPED_SIG; 2149 goto runfast; 2150 } 2151 2152 if (prop & SA_CONT) { 2153 /* 2154 * If traced process is already stopped, 2155 * then no further action is necessary. 2156 */ 2157 if (p->p_flag & P_TRACED) 2158 goto out; 2159 /* 2160 * If SIGCONT is default (or ignored), we continue the 2161 * process but don't leave the signal in sigqueue as 2162 * it has no further action. If SIGCONT is held, we 2163 * continue the process and leave the signal in 2164 * sigqueue. If the process catches SIGCONT, let it 2165 * handle the signal itself. If it isn't waiting on 2166 * an event, it goes back to run state. 2167 * Otherwise, process goes back to sleep state. 2168 */ 2169 p->p_flag &= ~P_STOPPED_SIG; 2170 PROC_SLOCK(p); 2171 if (p->p_numthreads == p->p_suspcount) { 2172 PROC_SUNLOCK(p); 2173 p->p_flag |= P_CONTINUED; 2174 p->p_xstat = SIGCONT; 2175 PROC_LOCK(p->p_pptr); 2176 childproc_continued(p); 2177 PROC_UNLOCK(p->p_pptr); 2178 PROC_SLOCK(p); 2179 } 2180 if (action == SIG_DFL) { 2181 thread_unsuspend(p); 2182 PROC_SUNLOCK(p); 2183 sigqueue_delete(sigqueue, sig); 2184 goto out; 2185 } 2186 if (action == SIG_CATCH) { 2187 /* 2188 * The process wants to catch it so it needs 2189 * to run at least one thread, but which one? 2190 */ 2191 PROC_SUNLOCK(p); 2192 goto runfast; 2193 } 2194 /* 2195 * The signal is not ignored or caught. 2196 */ 2197 thread_unsuspend(p); 2198 PROC_SUNLOCK(p); 2199 goto out; 2200 } 2201 2202 if (prop & SA_STOP) { 2203 /* 2204 * If traced process is already stopped, 2205 * then no further action is necessary. 2206 */ 2207 if (p->p_flag & P_TRACED) 2208 goto out; 2209 /* 2210 * Already stopped, don't need to stop again 2211 * (If we did the shell could get confused). 2212 * Just make sure the signal STOP bit set. 2213 */ 2214 p->p_flag |= P_STOPPED_SIG; 2215 sigqueue_delete(sigqueue, sig); 2216 goto out; 2217 } 2218 2219 /* 2220 * All other kinds of signals: 2221 * If a thread is sleeping interruptibly, simulate a 2222 * wakeup so that when it is continued it will be made 2223 * runnable and can look at the signal. However, don't make 2224 * the PROCESS runnable, leave it stopped. 2225 * It may run a bit until it hits a thread_suspend_check(). 2226 */ 2227 wakeup_swapper = 0; 2228 PROC_SLOCK(p); 2229 thread_lock(td); 2230 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2231 wakeup_swapper = sleepq_abort(td, intrval); 2232 thread_unlock(td); 2233 PROC_SUNLOCK(p); 2234 if (wakeup_swapper) 2235 kick_proc0(); 2236 goto out; 2237 /* 2238 * Mutexes are short lived. Threads waiting on them will 2239 * hit thread_suspend_check() soon. 2240 */ 2241 } else if (p->p_state == PRS_NORMAL) { 2242 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2243 tdsigwakeup(td, sig, action, intrval); 2244 goto out; 2245 } 2246 2247 MPASS(action == SIG_DFL); 2248 2249 if (prop & SA_STOP) { 2250 if (p->p_flag & P_PPWAIT) 2251 goto out; 2252 p->p_flag |= P_STOPPED_SIG; 2253 p->p_xstat = sig; 2254 PROC_SLOCK(p); 2255 sig_suspend_threads(td, p, 1); 2256 if (p->p_numthreads == p->p_suspcount) { 2257 /* 2258 * only thread sending signal to another 2259 * process can reach here, if thread is sending 2260 * signal to its process, because thread does 2261 * not suspend itself here, p_numthreads 2262 * should never be equal to p_suspcount. 2263 */ 2264 thread_stopped(p); 2265 PROC_SUNLOCK(p); 2266 sigqueue_delete_proc(p, p->p_xstat); 2267 } else 2268 PROC_SUNLOCK(p); 2269 goto out; 2270 } 2271 } else { 2272 /* Not in "NORMAL" state. discard the signal. */ 2273 sigqueue_delete(sigqueue, sig); 2274 goto out; 2275 } 2276 2277 /* 2278 * The process is not stopped so we need to apply the signal to all the 2279 * running threads. 2280 */ 2281 runfast: 2282 tdsigwakeup(td, sig, action, intrval); 2283 PROC_SLOCK(p); 2284 thread_unsuspend(p); 2285 PROC_SUNLOCK(p); 2286 out: 2287 /* If we jump here, proc slock should not be owned. */ 2288 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2289 return (ret); 2290 } 2291 2292 /* 2293 * The force of a signal has been directed against a single 2294 * thread. We need to see what we can do about knocking it 2295 * out of any sleep it may be in etc. 2296 */ 2297 static void 2298 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2299 { 2300 struct proc *p = td->td_proc; 2301 register int prop; 2302 int wakeup_swapper; 2303 2304 wakeup_swapper = 0; 2305 PROC_LOCK_ASSERT(p, MA_OWNED); 2306 prop = sigprop(sig); 2307 2308 PROC_SLOCK(p); 2309 thread_lock(td); 2310 /* 2311 * Bring the priority of a thread up if we want it to get 2312 * killed in this lifetime. 2313 */ 2314 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2315 sched_prio(td, PUSER); 2316 if (TD_ON_SLEEPQ(td)) { 2317 /* 2318 * If thread is sleeping uninterruptibly 2319 * we can't interrupt the sleep... the signal will 2320 * be noticed when the process returns through 2321 * trap() or syscall(). 2322 */ 2323 if ((td->td_flags & TDF_SINTR) == 0) 2324 goto out; 2325 /* 2326 * If SIGCONT is default (or ignored) and process is 2327 * asleep, we are finished; the process should not 2328 * be awakened. 2329 */ 2330 if ((prop & SA_CONT) && action == SIG_DFL) { 2331 thread_unlock(td); 2332 PROC_SUNLOCK(p); 2333 sigqueue_delete(&p->p_sigqueue, sig); 2334 /* 2335 * It may be on either list in this state. 2336 * Remove from both for now. 2337 */ 2338 sigqueue_delete(&td->td_sigqueue, sig); 2339 return; 2340 } 2341 2342 /* 2343 * Give low priority threads a better chance to run. 2344 */ 2345 if (td->td_priority > PUSER) 2346 sched_prio(td, PUSER); 2347 2348 wakeup_swapper = sleepq_abort(td, intrval); 2349 } else { 2350 /* 2351 * Other states do nothing with the signal immediately, 2352 * other than kicking ourselves if we are running. 2353 * It will either never be noticed, or noticed very soon. 2354 */ 2355 #ifdef SMP 2356 if (TD_IS_RUNNING(td) && td != curthread) 2357 forward_signal(td); 2358 #endif 2359 } 2360 out: 2361 PROC_SUNLOCK(p); 2362 thread_unlock(td); 2363 if (wakeup_swapper) 2364 kick_proc0(); 2365 } 2366 2367 static void 2368 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2369 { 2370 struct thread *td2; 2371 int wakeup_swapper; 2372 2373 PROC_LOCK_ASSERT(p, MA_OWNED); 2374 PROC_SLOCK_ASSERT(p, MA_OWNED); 2375 2376 wakeup_swapper = 0; 2377 FOREACH_THREAD_IN_PROC(p, td2) { 2378 thread_lock(td2); 2379 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2380 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2381 (td2->td_flags & TDF_SINTR)) { 2382 if (td2->td_flags & TDF_SBDRY) { 2383 if (TD_IS_SUSPENDED(td2)) 2384 wakeup_swapper |= 2385 thread_unsuspend_one(td2); 2386 if (TD_ON_SLEEPQ(td2)) 2387 wakeup_swapper |= 2388 sleepq_abort(td2, ERESTART); 2389 } else if (!TD_IS_SUSPENDED(td2)) { 2390 thread_suspend_one(td2); 2391 } 2392 } else if (!TD_IS_SUSPENDED(td2)) { 2393 if (sending || td != td2) 2394 td2->td_flags |= TDF_ASTPENDING; 2395 #ifdef SMP 2396 if (TD_IS_RUNNING(td2) && td2 != td) 2397 forward_signal(td2); 2398 #endif 2399 } 2400 thread_unlock(td2); 2401 } 2402 if (wakeup_swapper) 2403 kick_proc0(); 2404 } 2405 2406 int 2407 ptracestop(struct thread *td, int sig) 2408 { 2409 struct proc *p = td->td_proc; 2410 2411 PROC_LOCK_ASSERT(p, MA_OWNED); 2412 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2413 &p->p_mtx.lock_object, "Stopping for traced signal"); 2414 2415 td->td_dbgflags |= TDB_XSIG; 2416 td->td_xsig = sig; 2417 PROC_SLOCK(p); 2418 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2419 if (p->p_flag & P_SINGLE_EXIT) { 2420 td->td_dbgflags &= ~TDB_XSIG; 2421 PROC_SUNLOCK(p); 2422 return (sig); 2423 } 2424 /* 2425 * Just make wait() to work, the last stopped thread 2426 * will win. 2427 */ 2428 p->p_xstat = sig; 2429 p->p_xthread = td; 2430 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2431 sig_suspend_threads(td, p, 0); 2432 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2433 td->td_dbgflags &= ~TDB_STOPATFORK; 2434 cv_broadcast(&p->p_dbgwait); 2435 } 2436 stopme: 2437 thread_suspend_switch(td); 2438 if (!(p->p_flag & P_TRACED)) { 2439 break; 2440 } 2441 if (td->td_dbgflags & TDB_SUSPEND) { 2442 if (p->p_flag & P_SINGLE_EXIT) 2443 break; 2444 goto stopme; 2445 } 2446 } 2447 PROC_SUNLOCK(p); 2448 return (td->td_xsig); 2449 } 2450 2451 static void 2452 reschedule_signals(struct proc *p, sigset_t block, int flags) 2453 { 2454 struct sigacts *ps; 2455 struct thread *td; 2456 int sig; 2457 2458 PROC_LOCK_ASSERT(p, MA_OWNED); 2459 if (SIGISEMPTY(p->p_siglist)) 2460 return; 2461 ps = p->p_sigacts; 2462 SIGSETAND(block, p->p_siglist); 2463 while ((sig = sig_ffs(&block)) != 0) { 2464 SIGDELSET(block, sig); 2465 td = sigtd(p, sig, 0); 2466 signotify(td); 2467 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2468 mtx_lock(&ps->ps_mtx); 2469 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2470 tdsigwakeup(td, sig, SIG_CATCH, 2471 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2472 ERESTART)); 2473 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2474 mtx_unlock(&ps->ps_mtx); 2475 } 2476 } 2477 2478 void 2479 tdsigcleanup(struct thread *td) 2480 { 2481 struct proc *p; 2482 sigset_t unblocked; 2483 2484 p = td->td_proc; 2485 PROC_LOCK_ASSERT(p, MA_OWNED); 2486 2487 sigqueue_flush(&td->td_sigqueue); 2488 if (p->p_numthreads == 1) 2489 return; 2490 2491 /* 2492 * Since we cannot handle signals, notify signal post code 2493 * about this by filling the sigmask. 2494 * 2495 * Also, if needed, wake up thread(s) that do not block the 2496 * same signals as the exiting thread, since the thread might 2497 * have been selected for delivery and woken up. 2498 */ 2499 SIGFILLSET(unblocked); 2500 SIGSETNAND(unblocked, td->td_sigmask); 2501 SIGFILLSET(td->td_sigmask); 2502 reschedule_signals(p, unblocked, 0); 2503 2504 } 2505 2506 /* 2507 * If the current process has received a signal (should be caught or cause 2508 * termination, should interrupt current syscall), return the signal number. 2509 * Stop signals with default action are processed immediately, then cleared; 2510 * they aren't returned. This is checked after each entry to the system for 2511 * a syscall or trap (though this can usually be done without calling issignal 2512 * by checking the pending signal masks in cursig.) The normal call 2513 * sequence is 2514 * 2515 * while (sig = cursig(curthread)) 2516 * postsig(sig); 2517 */ 2518 static int 2519 issignal(struct thread *td, int stop_allowed) 2520 { 2521 struct proc *p; 2522 struct sigacts *ps; 2523 struct sigqueue *queue; 2524 sigset_t sigpending; 2525 int sig, prop, newsig; 2526 2527 p = td->td_proc; 2528 ps = p->p_sigacts; 2529 mtx_assert(&ps->ps_mtx, MA_OWNED); 2530 PROC_LOCK_ASSERT(p, MA_OWNED); 2531 for (;;) { 2532 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2533 2534 sigpending = td->td_sigqueue.sq_signals; 2535 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2536 SIGSETNAND(sigpending, td->td_sigmask); 2537 2538 if (p->p_flag & P_PPWAIT) 2539 SIG_STOPSIGMASK(sigpending); 2540 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2541 return (0); 2542 sig = sig_ffs(&sigpending); 2543 2544 if (p->p_stops & S_SIG) { 2545 mtx_unlock(&ps->ps_mtx); 2546 stopevent(p, S_SIG, sig); 2547 mtx_lock(&ps->ps_mtx); 2548 } 2549 2550 /* 2551 * We should see pending but ignored signals 2552 * only if P_TRACED was on when they were posted. 2553 */ 2554 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2555 sigqueue_delete(&td->td_sigqueue, sig); 2556 sigqueue_delete(&p->p_sigqueue, sig); 2557 continue; 2558 } 2559 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2560 /* 2561 * If traced, always stop. 2562 * Remove old signal from queue before the stop. 2563 * XXX shrug off debugger, it causes siginfo to 2564 * be thrown away. 2565 */ 2566 queue = &td->td_sigqueue; 2567 td->td_dbgksi.ksi_signo = 0; 2568 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2569 queue = &p->p_sigqueue; 2570 sigqueue_get(queue, sig, &td->td_dbgksi); 2571 } 2572 2573 mtx_unlock(&ps->ps_mtx); 2574 newsig = ptracestop(td, sig); 2575 mtx_lock(&ps->ps_mtx); 2576 2577 if (sig != newsig) { 2578 2579 /* 2580 * If parent wants us to take the signal, 2581 * then it will leave it in p->p_xstat; 2582 * otherwise we just look for signals again. 2583 */ 2584 if (newsig == 0) 2585 continue; 2586 sig = newsig; 2587 2588 /* 2589 * Put the new signal into td_sigqueue. If the 2590 * signal is being masked, look for other signals. 2591 */ 2592 sigqueue_add(queue, sig, NULL); 2593 if (SIGISMEMBER(td->td_sigmask, sig)) 2594 continue; 2595 signotify(td); 2596 } else { 2597 if (td->td_dbgksi.ksi_signo != 0) { 2598 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2599 if (sigqueue_add(&td->td_sigqueue, sig, 2600 &td->td_dbgksi) != 0) 2601 td->td_dbgksi.ksi_signo = 0; 2602 } 2603 if (td->td_dbgksi.ksi_signo == 0) 2604 sigqueue_add(&td->td_sigqueue, sig, 2605 NULL); 2606 } 2607 2608 /* 2609 * If the traced bit got turned off, go back up 2610 * to the top to rescan signals. This ensures 2611 * that p_sig* and p_sigact are consistent. 2612 */ 2613 if ((p->p_flag & P_TRACED) == 0) 2614 continue; 2615 } 2616 2617 prop = sigprop(sig); 2618 2619 /* 2620 * Decide whether the signal should be returned. 2621 * Return the signal's number, or fall through 2622 * to clear it from the pending mask. 2623 */ 2624 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2625 2626 case (intptr_t)SIG_DFL: 2627 /* 2628 * Don't take default actions on system processes. 2629 */ 2630 if (p->p_pid <= 1) { 2631 #ifdef DIAGNOSTIC 2632 /* 2633 * Are you sure you want to ignore SIGSEGV 2634 * in init? XXX 2635 */ 2636 printf("Process (pid %lu) got signal %d\n", 2637 (u_long)p->p_pid, sig); 2638 #endif 2639 break; /* == ignore */ 2640 } 2641 /* 2642 * If there is a pending stop signal to process 2643 * with default action, stop here, 2644 * then clear the signal. However, 2645 * if process is member of an orphaned 2646 * process group, ignore tty stop signals. 2647 */ 2648 if (prop & SA_STOP) { 2649 if (p->p_flag & P_TRACED || 2650 (p->p_pgrp->pg_jobc == 0 && 2651 prop & SA_TTYSTOP)) 2652 break; /* == ignore */ 2653 2654 /* Ignore, but do not drop the stop signal. */ 2655 if (stop_allowed != SIG_STOP_ALLOWED) 2656 return (sig); 2657 mtx_unlock(&ps->ps_mtx); 2658 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2659 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2660 p->p_flag |= P_STOPPED_SIG; 2661 p->p_xstat = sig; 2662 PROC_SLOCK(p); 2663 sig_suspend_threads(td, p, 0); 2664 thread_suspend_switch(td); 2665 PROC_SUNLOCK(p); 2666 mtx_lock(&ps->ps_mtx); 2667 break; 2668 } else if (prop & SA_IGNORE) { 2669 /* 2670 * Except for SIGCONT, shouldn't get here. 2671 * Default action is to ignore; drop it. 2672 */ 2673 break; /* == ignore */ 2674 } else 2675 return (sig); 2676 /*NOTREACHED*/ 2677 2678 case (intptr_t)SIG_IGN: 2679 /* 2680 * Masking above should prevent us ever trying 2681 * to take action on an ignored signal other 2682 * than SIGCONT, unless process is traced. 2683 */ 2684 if ((prop & SA_CONT) == 0 && 2685 (p->p_flag & P_TRACED) == 0) 2686 printf("issignal\n"); 2687 break; /* == ignore */ 2688 2689 default: 2690 /* 2691 * This signal has an action, let 2692 * postsig() process it. 2693 */ 2694 return (sig); 2695 } 2696 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2697 sigqueue_delete(&p->p_sigqueue, sig); 2698 } 2699 /* NOTREACHED */ 2700 } 2701 2702 void 2703 thread_stopped(struct proc *p) 2704 { 2705 int n; 2706 2707 PROC_LOCK_ASSERT(p, MA_OWNED); 2708 PROC_SLOCK_ASSERT(p, MA_OWNED); 2709 n = p->p_suspcount; 2710 if (p == curproc) 2711 n++; 2712 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2713 PROC_SUNLOCK(p); 2714 p->p_flag &= ~P_WAITED; 2715 PROC_LOCK(p->p_pptr); 2716 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2717 CLD_TRAPPED : CLD_STOPPED); 2718 PROC_UNLOCK(p->p_pptr); 2719 PROC_SLOCK(p); 2720 } 2721 } 2722 2723 /* 2724 * Take the action for the specified signal 2725 * from the current set of pending signals. 2726 */ 2727 int 2728 postsig(sig) 2729 register int sig; 2730 { 2731 struct thread *td = curthread; 2732 register struct proc *p = td->td_proc; 2733 struct sigacts *ps; 2734 sig_t action; 2735 ksiginfo_t ksi; 2736 sigset_t returnmask, mask; 2737 2738 KASSERT(sig != 0, ("postsig")); 2739 2740 PROC_LOCK_ASSERT(p, MA_OWNED); 2741 ps = p->p_sigacts; 2742 mtx_assert(&ps->ps_mtx, MA_OWNED); 2743 ksiginfo_init(&ksi); 2744 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2745 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2746 return (0); 2747 ksi.ksi_signo = sig; 2748 if (ksi.ksi_code == SI_TIMER) 2749 itimer_accept(p, ksi.ksi_timerid, &ksi); 2750 action = ps->ps_sigact[_SIG_IDX(sig)]; 2751 #ifdef KTRACE 2752 if (KTRPOINT(td, KTR_PSIG)) 2753 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2754 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2755 #endif 2756 if (p->p_stops & S_SIG) { 2757 mtx_unlock(&ps->ps_mtx); 2758 stopevent(p, S_SIG, sig); 2759 mtx_lock(&ps->ps_mtx); 2760 } 2761 2762 if (action == SIG_DFL) { 2763 /* 2764 * Default action, where the default is to kill 2765 * the process. (Other cases were ignored above.) 2766 */ 2767 mtx_unlock(&ps->ps_mtx); 2768 sigexit(td, sig); 2769 /* NOTREACHED */ 2770 } else { 2771 /* 2772 * If we get here, the signal must be caught. 2773 */ 2774 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2775 ("postsig action")); 2776 /* 2777 * Set the new mask value and also defer further 2778 * occurrences of this signal. 2779 * 2780 * Special case: user has done a sigsuspend. Here the 2781 * current mask is not of interest, but rather the 2782 * mask from before the sigsuspend is what we want 2783 * restored after the signal processing is completed. 2784 */ 2785 if (td->td_pflags & TDP_OLDMASK) { 2786 returnmask = td->td_oldsigmask; 2787 td->td_pflags &= ~TDP_OLDMASK; 2788 } else 2789 returnmask = td->td_sigmask; 2790 2791 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2792 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2793 SIGADDSET(mask, sig); 2794 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2795 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2796 2797 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2798 /* 2799 * See kern_sigaction() for origin of this code. 2800 */ 2801 SIGDELSET(ps->ps_sigcatch, sig); 2802 if (sig != SIGCONT && 2803 sigprop(sig) & SA_IGNORE) 2804 SIGADDSET(ps->ps_sigignore, sig); 2805 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2806 } 2807 td->td_ru.ru_nsignals++; 2808 if (p->p_sig == sig) { 2809 p->p_code = 0; 2810 p->p_sig = 0; 2811 } 2812 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2813 } 2814 return (1); 2815 } 2816 2817 /* 2818 * Kill the current process for stated reason. 2819 */ 2820 void 2821 killproc(p, why) 2822 struct proc *p; 2823 char *why; 2824 { 2825 2826 PROC_LOCK_ASSERT(p, MA_OWNED); 2827 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2828 p, p->p_pid, p->p_comm); 2829 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2830 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2831 p->p_flag |= P_WKILLED; 2832 kern_psignal(p, SIGKILL); 2833 } 2834 2835 /* 2836 * Force the current process to exit with the specified signal, dumping core 2837 * if appropriate. We bypass the normal tests for masked and caught signals, 2838 * allowing unrecoverable failures to terminate the process without changing 2839 * signal state. Mark the accounting record with the signal termination. 2840 * If dumping core, save the signal number for the debugger. Calls exit and 2841 * does not return. 2842 */ 2843 void 2844 sigexit(td, sig) 2845 struct thread *td; 2846 int sig; 2847 { 2848 struct proc *p = td->td_proc; 2849 2850 PROC_LOCK_ASSERT(p, MA_OWNED); 2851 p->p_acflag |= AXSIG; 2852 /* 2853 * We must be single-threading to generate a core dump. This 2854 * ensures that the registers in the core file are up-to-date. 2855 * Also, the ELF dump handler assumes that the thread list doesn't 2856 * change out from under it. 2857 * 2858 * XXX If another thread attempts to single-thread before us 2859 * (e.g. via fork()), we won't get a dump at all. 2860 */ 2861 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2862 p->p_sig = sig; 2863 /* 2864 * Log signals which would cause core dumps 2865 * (Log as LOG_INFO to appease those who don't want 2866 * these messages.) 2867 * XXX : Todo, as well as euid, write out ruid too 2868 * Note that coredump() drops proc lock. 2869 */ 2870 if (coredump(td) == 0) 2871 sig |= WCOREFLAG; 2872 if (kern_logsigexit) 2873 log(LOG_INFO, 2874 "pid %d (%s), uid %d: exited on signal %d%s\n", 2875 p->p_pid, p->p_comm, 2876 td->td_ucred ? td->td_ucred->cr_uid : -1, 2877 sig &~ WCOREFLAG, 2878 sig & WCOREFLAG ? " (core dumped)" : ""); 2879 } else 2880 PROC_UNLOCK(p); 2881 exit1(td, W_EXITCODE(0, sig)); 2882 /* NOTREACHED */ 2883 } 2884 2885 /* 2886 * Send queued SIGCHLD to parent when child process's state 2887 * is changed. 2888 */ 2889 static void 2890 sigparent(struct proc *p, int reason, int status) 2891 { 2892 PROC_LOCK_ASSERT(p, MA_OWNED); 2893 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2894 2895 if (p->p_ksi != NULL) { 2896 p->p_ksi->ksi_signo = SIGCHLD; 2897 p->p_ksi->ksi_code = reason; 2898 p->p_ksi->ksi_status = status; 2899 p->p_ksi->ksi_pid = p->p_pid; 2900 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2901 if (KSI_ONQ(p->p_ksi)) 2902 return; 2903 } 2904 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2905 } 2906 2907 static void 2908 childproc_jobstate(struct proc *p, int reason, int status) 2909 { 2910 struct sigacts *ps; 2911 2912 PROC_LOCK_ASSERT(p, MA_OWNED); 2913 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2914 2915 /* 2916 * Wake up parent sleeping in kern_wait(), also send 2917 * SIGCHLD to parent, but SIGCHLD does not guarantee 2918 * that parent will awake, because parent may masked 2919 * the signal. 2920 */ 2921 p->p_pptr->p_flag |= P_STATCHILD; 2922 wakeup(p->p_pptr); 2923 2924 ps = p->p_pptr->p_sigacts; 2925 mtx_lock(&ps->ps_mtx); 2926 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2927 mtx_unlock(&ps->ps_mtx); 2928 sigparent(p, reason, status); 2929 } else 2930 mtx_unlock(&ps->ps_mtx); 2931 } 2932 2933 void 2934 childproc_stopped(struct proc *p, int reason) 2935 { 2936 childproc_jobstate(p, reason, p->p_xstat); 2937 } 2938 2939 void 2940 childproc_continued(struct proc *p) 2941 { 2942 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2943 } 2944 2945 void 2946 childproc_exited(struct proc *p) 2947 { 2948 int reason; 2949 int status = p->p_xstat; /* convert to int */ 2950 2951 reason = CLD_EXITED; 2952 if (WCOREDUMP(status)) 2953 reason = CLD_DUMPED; 2954 else if (WIFSIGNALED(status)) 2955 reason = CLD_KILLED; 2956 /* 2957 * XXX avoid calling wakeup(p->p_pptr), the work is 2958 * done in exit1(). 2959 */ 2960 sigparent(p, reason, status); 2961 } 2962 2963 /* 2964 * We only have 1 character for the core count in the format 2965 * string, so the range will be 0-9 2966 */ 2967 #define MAX_NUM_CORES 10 2968 static int num_cores = 5; 2969 2970 static int 2971 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 2972 { 2973 int error; 2974 int new_val; 2975 2976 new_val = num_cores; 2977 error = sysctl_handle_int(oidp, &new_val, 0, req); 2978 if (error != 0 || req->newptr == NULL) 2979 return (error); 2980 if (new_val > MAX_NUM_CORES) 2981 new_val = MAX_NUM_CORES; 2982 if (new_val < 0) 2983 new_val = 0; 2984 num_cores = new_val; 2985 return (0); 2986 } 2987 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 2988 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 2989 2990 #if defined(COMPRESS_USER_CORES) 2991 int compress_user_cores = 1; 2992 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 2993 &compress_user_cores, 0, ""); 2994 2995 int compress_user_cores_gzlevel = -1; /* default level */ 2996 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 2997 &compress_user_cores_gzlevel, -1, "user core gz compression level"); 2998 2999 #define GZ_SUFFIX ".gz" 3000 #define GZ_SUFFIX_LEN 3 3001 #endif 3002 3003 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3004 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3005 sizeof(corefilename), "process corefile name format string"); 3006 3007 /* 3008 * expand_name(name, uid, pid, td, compress) 3009 * Expand the name described in corefilename, using name, uid, and pid. 3010 * corefilename is a printf-like string, with three format specifiers: 3011 * %N name of process ("name") 3012 * %P process id (pid) 3013 * %U user id (uid) 3014 * For example, "%N.core" is the default; they can be disabled completely 3015 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3016 * This is controlled by the sysctl variable kern.corefile (see above). 3017 */ 3018 static char * 3019 expand_name(const char *name, uid_t uid, pid_t pid, struct thread *td, 3020 int compress) 3021 { 3022 struct sbuf sb; 3023 const char *format; 3024 char *temp; 3025 size_t i; 3026 int indexpos; 3027 char *hostname; 3028 3029 hostname = NULL; 3030 format = corefilename; 3031 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 3032 if (temp == NULL) 3033 return (NULL); 3034 indexpos = -1; 3035 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 3036 for (i = 0; format[i]; i++) { 3037 switch (format[i]) { 3038 case '%': /* Format character */ 3039 i++; 3040 switch (format[i]) { 3041 case '%': 3042 sbuf_putc(&sb, '%'); 3043 break; 3044 case 'H': /* hostname */ 3045 if (hostname == NULL) { 3046 hostname = malloc(MAXHOSTNAMELEN, 3047 M_TEMP, M_NOWAIT); 3048 if (hostname == NULL) { 3049 log(LOG_ERR, 3050 "pid %ld (%s), uid (%lu): " 3051 "unable to alloc memory " 3052 "for corefile hostname\n", 3053 (long)pid, name, 3054 (u_long)uid); 3055 goto nomem; 3056 } 3057 } 3058 getcredhostname(td->td_ucred, hostname, 3059 MAXHOSTNAMELEN); 3060 sbuf_printf(&sb, "%s", hostname); 3061 break; 3062 case 'I': /* autoincrementing index */ 3063 sbuf_printf(&sb, "0"); 3064 indexpos = sbuf_len(&sb) - 1; 3065 break; 3066 case 'N': /* process name */ 3067 sbuf_printf(&sb, "%s", name); 3068 break; 3069 case 'P': /* process id */ 3070 sbuf_printf(&sb, "%u", pid); 3071 break; 3072 case 'U': /* user id */ 3073 sbuf_printf(&sb, "%u", uid); 3074 break; 3075 default: 3076 log(LOG_ERR, 3077 "Unknown format character %c in " 3078 "corename `%s'\n", format[i], format); 3079 } 3080 break; 3081 default: 3082 sbuf_putc(&sb, format[i]); 3083 } 3084 } 3085 free(hostname, M_TEMP); 3086 #ifdef COMPRESS_USER_CORES 3087 if (compress) { 3088 sbuf_printf(&sb, GZ_SUFFIX); 3089 } 3090 #endif 3091 if (sbuf_error(&sb) != 0) { 3092 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3093 "long\n", (long)pid, name, (u_long)uid); 3094 nomem: 3095 sbuf_delete(&sb); 3096 free(temp, M_TEMP); 3097 return (NULL); 3098 } 3099 sbuf_finish(&sb); 3100 sbuf_delete(&sb); 3101 3102 /* 3103 * If the core format has a %I in it, then we need to check 3104 * for existing corefiles before returning a name. 3105 * To do this we iterate over 0..num_cores to find a 3106 * non-existing core file name to use. 3107 */ 3108 if (indexpos != -1) { 3109 struct nameidata nd; 3110 int error, n; 3111 int flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3112 int cmode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP; 3113 int vfslocked; 3114 3115 for (n = 0; n < num_cores; n++) { 3116 temp[indexpos] = '0' + n; 3117 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, 3118 temp, td); 3119 error = vn_open(&nd, &flags, cmode, NULL); 3120 if (error) { 3121 if (error == EEXIST) { 3122 continue; 3123 } 3124 log(LOG_ERR, 3125 "pid %d (%s), uid (%u): Path `%s' failed " 3126 "on initial open test, error = %d\n", 3127 pid, name, uid, temp, error); 3128 free(temp, M_TEMP); 3129 return (NULL); 3130 } 3131 vfslocked = NDHASGIANT(&nd); 3132 NDFREE(&nd, NDF_ONLY_PNBUF); 3133 VOP_UNLOCK(nd.ni_vp, 0); 3134 error = vn_close(nd.ni_vp, FWRITE, td->td_ucred, td); 3135 VFS_UNLOCK_GIANT(vfslocked); 3136 if (error) { 3137 log(LOG_ERR, 3138 "pid %d (%s), uid (%u): Path `%s' failed " 3139 "on close after initial open test, " 3140 "error = %d\n", 3141 pid, name, uid, temp, error); 3142 free(temp, M_TEMP); 3143 return (NULL); 3144 } 3145 break; 3146 } 3147 } 3148 return (temp); 3149 } 3150 3151 /* 3152 * Dump a process' core. The main routine does some 3153 * policy checking, and creates the name of the coredump; 3154 * then it passes on a vnode and a size limit to the process-specific 3155 * coredump routine if there is one; if there _is not_ one, it returns 3156 * ENOSYS; otherwise it returns the error from the process-specific routine. 3157 */ 3158 3159 static int 3160 coredump(struct thread *td) 3161 { 3162 struct proc *p = td->td_proc; 3163 register struct vnode *vp; 3164 register struct ucred *cred = td->td_ucred; 3165 struct flock lf; 3166 struct nameidata nd; 3167 struct vattr vattr; 3168 int error, error1, flags, locked; 3169 struct mount *mp; 3170 char *name; /* name of corefile */ 3171 off_t limit; 3172 int vfslocked; 3173 int compress; 3174 3175 #ifdef COMPRESS_USER_CORES 3176 compress = compress_user_cores; 3177 #else 3178 compress = 0; 3179 #endif 3180 PROC_LOCK_ASSERT(p, MA_OWNED); 3181 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3182 _STOPEVENT(p, S_CORE, 0); 3183 3184 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid, td, 3185 compress); 3186 if (name == NULL) { 3187 PROC_UNLOCK(p); 3188 #ifdef AUDIT 3189 audit_proc_coredump(td, NULL, EINVAL); 3190 #endif 3191 return (EINVAL); 3192 } 3193 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3194 PROC_UNLOCK(p); 3195 #ifdef AUDIT 3196 audit_proc_coredump(td, name, EFAULT); 3197 #endif 3198 free(name, M_TEMP); 3199 return (EFAULT); 3200 } 3201 3202 /* 3203 * Note that the bulk of limit checking is done after 3204 * the corefile is created. The exception is if the limit 3205 * for corefiles is 0, in which case we don't bother 3206 * creating the corefile at all. This layout means that 3207 * a corefile is truncated instead of not being created, 3208 * if it is larger than the limit. 3209 */ 3210 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3211 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3212 PROC_UNLOCK(p); 3213 #ifdef AUDIT 3214 audit_proc_coredump(td, name, EFBIG); 3215 #endif 3216 free(name, M_TEMP); 3217 return (EFBIG); 3218 } 3219 PROC_UNLOCK(p); 3220 3221 restart: 3222 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3223 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3224 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3225 cred, NULL); 3226 if (error) { 3227 #ifdef AUDIT 3228 audit_proc_coredump(td, name, error); 3229 #endif 3230 free(name, M_TEMP); 3231 return (error); 3232 } 3233 vfslocked = NDHASGIANT(&nd); 3234 NDFREE(&nd, NDF_ONLY_PNBUF); 3235 vp = nd.ni_vp; 3236 3237 /* Don't dump to non-regular files or files with links. */ 3238 if (vp->v_type != VREG || 3239 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3240 VOP_UNLOCK(vp, 0); 3241 error = EFAULT; 3242 goto close; 3243 } 3244 3245 VOP_UNLOCK(vp, 0); 3246 lf.l_whence = SEEK_SET; 3247 lf.l_start = 0; 3248 lf.l_len = 0; 3249 lf.l_type = F_WRLCK; 3250 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3251 3252 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3253 lf.l_type = F_UNLCK; 3254 if (locked) 3255 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3256 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3257 goto out; 3258 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3259 goto out; 3260 VFS_UNLOCK_GIANT(vfslocked); 3261 goto restart; 3262 } 3263 3264 VATTR_NULL(&vattr); 3265 vattr.va_size = 0; 3266 if (set_core_nodump_flag) 3267 vattr.va_flags = UF_NODUMP; 3268 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3269 VOP_SETATTR(vp, &vattr, cred); 3270 VOP_UNLOCK(vp, 0); 3271 vn_finished_write(mp); 3272 PROC_LOCK(p); 3273 p->p_acflag |= ACORE; 3274 PROC_UNLOCK(p); 3275 3276 error = p->p_sysent->sv_coredump ? 3277 p->p_sysent->sv_coredump(td, vp, limit, compress ? IMGACT_CORE_COMPRESS : 0) : 3278 ENOSYS; 3279 3280 if (locked) { 3281 lf.l_type = F_UNLCK; 3282 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3283 } 3284 close: 3285 error1 = vn_close(vp, FWRITE, cred, td); 3286 if (error == 0) 3287 error = error1; 3288 out: 3289 #ifdef AUDIT 3290 audit_proc_coredump(td, name, error); 3291 #endif 3292 free(name, M_TEMP); 3293 VFS_UNLOCK_GIANT(vfslocked); 3294 return (error); 3295 } 3296 3297 /* 3298 * Nonexistent system call-- signal process (may want to handle it). Flag 3299 * error in case process won't see signal immediately (blocked or ignored). 3300 */ 3301 #ifndef _SYS_SYSPROTO_H_ 3302 struct nosys_args { 3303 int dummy; 3304 }; 3305 #endif 3306 /* ARGSUSED */ 3307 int 3308 nosys(td, args) 3309 struct thread *td; 3310 struct nosys_args *args; 3311 { 3312 struct proc *p = td->td_proc; 3313 3314 PROC_LOCK(p); 3315 kern_psignal(p, SIGSYS); 3316 PROC_UNLOCK(p); 3317 return (ENOSYS); 3318 } 3319 3320 /* 3321 * Send a SIGIO or SIGURG signal to a process or process group using stored 3322 * credentials rather than those of the current process. 3323 */ 3324 void 3325 pgsigio(sigiop, sig, checkctty) 3326 struct sigio **sigiop; 3327 int sig, checkctty; 3328 { 3329 ksiginfo_t ksi; 3330 struct sigio *sigio; 3331 3332 ksiginfo_init(&ksi); 3333 ksi.ksi_signo = sig; 3334 ksi.ksi_code = SI_KERNEL; 3335 3336 SIGIO_LOCK(); 3337 sigio = *sigiop; 3338 if (sigio == NULL) { 3339 SIGIO_UNLOCK(); 3340 return; 3341 } 3342 if (sigio->sio_pgid > 0) { 3343 PROC_LOCK(sigio->sio_proc); 3344 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3345 kern_psignal(sigio->sio_proc, sig); 3346 PROC_UNLOCK(sigio->sio_proc); 3347 } else if (sigio->sio_pgid < 0) { 3348 struct proc *p; 3349 3350 PGRP_LOCK(sigio->sio_pgrp); 3351 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3352 PROC_LOCK(p); 3353 if (p->p_state == PRS_NORMAL && 3354 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3355 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3356 kern_psignal(p, sig); 3357 PROC_UNLOCK(p); 3358 } 3359 PGRP_UNLOCK(sigio->sio_pgrp); 3360 } 3361 SIGIO_UNLOCK(); 3362 } 3363 3364 static int 3365 filt_sigattach(struct knote *kn) 3366 { 3367 struct proc *p = curproc; 3368 3369 kn->kn_ptr.p_proc = p; 3370 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3371 3372 knlist_add(&p->p_klist, kn, 0); 3373 3374 return (0); 3375 } 3376 3377 static void 3378 filt_sigdetach(struct knote *kn) 3379 { 3380 struct proc *p = kn->kn_ptr.p_proc; 3381 3382 knlist_remove(&p->p_klist, kn, 0); 3383 } 3384 3385 /* 3386 * signal knotes are shared with proc knotes, so we apply a mask to 3387 * the hint in order to differentiate them from process hints. This 3388 * could be avoided by using a signal-specific knote list, but probably 3389 * isn't worth the trouble. 3390 */ 3391 static int 3392 filt_signal(struct knote *kn, long hint) 3393 { 3394 3395 if (hint & NOTE_SIGNAL) { 3396 hint &= ~NOTE_SIGNAL; 3397 3398 if (kn->kn_id == hint) 3399 kn->kn_data++; 3400 } 3401 return (kn->kn_data != 0); 3402 } 3403 3404 struct sigacts * 3405 sigacts_alloc(void) 3406 { 3407 struct sigacts *ps; 3408 3409 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3410 ps->ps_refcnt = 1; 3411 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3412 return (ps); 3413 } 3414 3415 void 3416 sigacts_free(struct sigacts *ps) 3417 { 3418 3419 mtx_lock(&ps->ps_mtx); 3420 ps->ps_refcnt--; 3421 if (ps->ps_refcnt == 0) { 3422 mtx_destroy(&ps->ps_mtx); 3423 free(ps, M_SUBPROC); 3424 } else 3425 mtx_unlock(&ps->ps_mtx); 3426 } 3427 3428 struct sigacts * 3429 sigacts_hold(struct sigacts *ps) 3430 { 3431 mtx_lock(&ps->ps_mtx); 3432 ps->ps_refcnt++; 3433 mtx_unlock(&ps->ps_mtx); 3434 return (ps); 3435 } 3436 3437 void 3438 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3439 { 3440 3441 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3442 mtx_lock(&src->ps_mtx); 3443 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3444 mtx_unlock(&src->ps_mtx); 3445 } 3446 3447 int 3448 sigacts_shared(struct sigacts *ps) 3449 { 3450 int shared; 3451 3452 mtx_lock(&ps->ps_mtx); 3453 shared = ps->ps_refcnt > 1; 3454 mtx_unlock(&ps->ps_mtx); 3455 return (shared); 3456 } 3457