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