1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_compat.h" 43 #include "opt_ktrace.h" 44 45 #include <sys/param.h> 46 #include <sys/ctype.h> 47 #include <sys/systm.h> 48 #include <sys/signalvar.h> 49 #include <sys/vnode.h> 50 #include <sys/acct.h> 51 #include <sys/bus.h> 52 #include <sys/capsicum.h> 53 #include <sys/compressor.h> 54 #include <sys/condvar.h> 55 #include <sys/event.h> 56 #include <sys/fcntl.h> 57 #include <sys/imgact.h> 58 #include <sys/kernel.h> 59 #include <sys/ktr.h> 60 #include <sys/ktrace.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/posix4.h> 69 #include <sys/pioctl.h> 70 #include <sys/racct.h> 71 #include <sys/resourcevar.h> 72 #include <sys/sdt.h> 73 #include <sys/sbuf.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sx.h> 78 #include <sys/syscallsubr.h> 79 #include <sys/sysctl.h> 80 #include <sys/sysent.h> 81 #include <sys/syslog.h> 82 #include <sys/sysproto.h> 83 #include <sys/timers.h> 84 #include <sys/unistd.h> 85 #include <sys/wait.h> 86 #include <vm/vm.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 #include <sys/jail.h> 91 92 #include <machine/cpu.h> 93 94 #include <security/audit/audit.h> 95 96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101 SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103 SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106 static int coredump(struct thread *); 107 static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109 static int issignal(struct thread *td); 110 static int sigprop(int sig); 111 static void tdsigwakeup(struct thread *, int, sig_t, int); 112 static int sig_suspend_threads(struct thread *, struct proc *, int); 113 static int filt_sigattach(struct knote *kn); 114 static void filt_sigdetach(struct knote *kn); 115 static int filt_signal(struct knote *kn, long hint); 116 static struct thread *sigtd(struct proc *p, int sig, int prop); 117 static void sigqueue_start(void); 118 119 static uma_zone_t ksiginfo_zone = NULL; 120 struct filterops sig_filtops = { 121 .f_isfd = 0, 122 .f_attach = filt_sigattach, 123 .f_detach = filt_sigdetach, 124 .f_event = filt_signal, 125 }; 126 127 static int kern_logsigexit = 1; 128 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 129 &kern_logsigexit, 0, 130 "Log processes quitting on abnormal signals to syslog(3)"); 131 132 static int kern_forcesigexit = 1; 133 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 134 &kern_forcesigexit, 0, "Force trap signal to be handled"); 135 136 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 137 "POSIX real time signal"); 138 139 static int max_pending_per_proc = 128; 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 141 &max_pending_per_proc, 0, "Max pending signals per proc"); 142 143 static int preallocate_siginfo = 1024; 144 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 145 &preallocate_siginfo, 0, "Preallocated signal memory size"); 146 147 static int signal_overflow = 0; 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 149 &signal_overflow, 0, "Number of signals overflew"); 150 151 static int signal_alloc_fail = 0; 152 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 153 &signal_alloc_fail, 0, "signals failed to be allocated"); 154 155 static int kern_lognosys = 0; 156 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 157 "Log invalid syscalls"); 158 159 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 160 161 /* 162 * Policy -- Can ucred cr1 send SIGIO to process cr2? 163 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 164 * in the right situations. 165 */ 166 #define CANSIGIO(cr1, cr2) \ 167 ((cr1)->cr_uid == 0 || \ 168 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 169 (cr1)->cr_uid == (cr2)->cr_ruid || \ 170 (cr1)->cr_ruid == (cr2)->cr_uid || \ 171 (cr1)->cr_uid == (cr2)->cr_uid) 172 173 static int sugid_coredump; 174 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 175 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 176 177 static int capmode_coredump; 178 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 179 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 180 181 static int do_coredump = 1; 182 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 183 &do_coredump, 0, "Enable/Disable coredumps"); 184 185 static int set_core_nodump_flag = 0; 186 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 187 0, "Enable setting the NODUMP flag on coredump files"); 188 189 static int coredump_devctl = 0; 190 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 191 0, "Generate a devctl notification when processes coredump"); 192 193 /* 194 * Signal properties and actions. 195 * The array below categorizes the signals and their default actions 196 * according to the following properties: 197 */ 198 #define SIGPROP_KILL 0x01 /* terminates process by default */ 199 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 200 #define SIGPROP_STOP 0x04 /* suspend process */ 201 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 202 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 203 #define SIGPROP_CONT 0x20 /* continue if suspended */ 204 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 205 206 static int sigproptbl[NSIG] = { 207 [SIGHUP] = SIGPROP_KILL, 208 [SIGINT] = SIGPROP_KILL, 209 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 215 [SIGKILL] = SIGPROP_KILL, 216 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGPIPE] = SIGPROP_KILL, 220 [SIGALRM] = SIGPROP_KILL, 221 [SIGTERM] = SIGPROP_KILL, 222 [SIGURG] = SIGPROP_IGNORE, 223 [SIGSTOP] = SIGPROP_STOP, 224 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 225 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 226 [SIGCHLD] = SIGPROP_IGNORE, 227 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 229 [SIGIO] = SIGPROP_IGNORE, 230 [SIGXCPU] = SIGPROP_KILL, 231 [SIGXFSZ] = SIGPROP_KILL, 232 [SIGVTALRM] = SIGPROP_KILL, 233 [SIGPROF] = SIGPROP_KILL, 234 [SIGWINCH] = SIGPROP_IGNORE, 235 [SIGINFO] = SIGPROP_IGNORE, 236 [SIGUSR1] = SIGPROP_KILL, 237 [SIGUSR2] = SIGPROP_KILL, 238 }; 239 240 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 241 242 static void 243 sigqueue_start(void) 244 { 245 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 246 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 247 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 248 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 249 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 250 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 251 } 252 253 ksiginfo_t * 254 ksiginfo_alloc(int wait) 255 { 256 int flags; 257 258 flags = M_ZERO; 259 if (! wait) 260 flags |= M_NOWAIT; 261 if (ksiginfo_zone != NULL) 262 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 263 return (NULL); 264 } 265 266 void 267 ksiginfo_free(ksiginfo_t *ksi) 268 { 269 uma_zfree(ksiginfo_zone, ksi); 270 } 271 272 static __inline int 273 ksiginfo_tryfree(ksiginfo_t *ksi) 274 { 275 if (!(ksi->ksi_flags & KSI_EXT)) { 276 uma_zfree(ksiginfo_zone, ksi); 277 return (1); 278 } 279 return (0); 280 } 281 282 void 283 sigqueue_init(sigqueue_t *list, struct proc *p) 284 { 285 SIGEMPTYSET(list->sq_signals); 286 SIGEMPTYSET(list->sq_kill); 287 SIGEMPTYSET(list->sq_ptrace); 288 TAILQ_INIT(&list->sq_list); 289 list->sq_proc = p; 290 list->sq_flags = SQ_INIT; 291 } 292 293 /* 294 * Get a signal's ksiginfo. 295 * Return: 296 * 0 - signal not found 297 * others - signal number 298 */ 299 static int 300 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 301 { 302 struct proc *p = sq->sq_proc; 303 struct ksiginfo *ksi, *next; 304 int count = 0; 305 306 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 307 308 if (!SIGISMEMBER(sq->sq_signals, signo)) 309 return (0); 310 311 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 312 count++; 313 SIGDELSET(sq->sq_ptrace, signo); 314 si->ksi_flags |= KSI_PTRACE; 315 } 316 if (SIGISMEMBER(sq->sq_kill, signo)) { 317 count++; 318 if (count == 1) 319 SIGDELSET(sq->sq_kill, signo); 320 } 321 322 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 323 if (ksi->ksi_signo == signo) { 324 if (count == 0) { 325 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 326 ksi->ksi_sigq = NULL; 327 ksiginfo_copy(ksi, si); 328 if (ksiginfo_tryfree(ksi) && p != NULL) 329 p->p_pendingcnt--; 330 } 331 if (++count > 1) 332 break; 333 } 334 } 335 336 if (count <= 1) 337 SIGDELSET(sq->sq_signals, signo); 338 si->ksi_signo = signo; 339 return (signo); 340 } 341 342 void 343 sigqueue_take(ksiginfo_t *ksi) 344 { 345 struct ksiginfo *kp; 346 struct proc *p; 347 sigqueue_t *sq; 348 349 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 350 return; 351 352 p = sq->sq_proc; 353 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 354 ksi->ksi_sigq = NULL; 355 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 356 p->p_pendingcnt--; 357 358 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 359 kp = TAILQ_NEXT(kp, ksi_link)) { 360 if (kp->ksi_signo == ksi->ksi_signo) 361 break; 362 } 363 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 364 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 365 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 366 } 367 368 static int 369 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 370 { 371 struct proc *p = sq->sq_proc; 372 struct ksiginfo *ksi; 373 int ret = 0; 374 375 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 376 377 /* 378 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 379 * for these signals. 380 */ 381 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 382 SIGADDSET(sq->sq_kill, signo); 383 goto out_set_bit; 384 } 385 386 /* directly insert the ksi, don't copy it */ 387 if (si->ksi_flags & KSI_INS) { 388 if (si->ksi_flags & KSI_HEAD) 389 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 390 else 391 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 392 si->ksi_sigq = sq; 393 goto out_set_bit; 394 } 395 396 if (__predict_false(ksiginfo_zone == NULL)) { 397 SIGADDSET(sq->sq_kill, signo); 398 goto out_set_bit; 399 } 400 401 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 402 signal_overflow++; 403 ret = EAGAIN; 404 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 405 signal_alloc_fail++; 406 ret = EAGAIN; 407 } else { 408 if (p != NULL) 409 p->p_pendingcnt++; 410 ksiginfo_copy(si, ksi); 411 ksi->ksi_signo = signo; 412 if (si->ksi_flags & KSI_HEAD) 413 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 414 else 415 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 416 ksi->ksi_sigq = sq; 417 } 418 419 if (ret != 0) { 420 if ((si->ksi_flags & KSI_PTRACE) != 0) { 421 SIGADDSET(sq->sq_ptrace, signo); 422 ret = 0; 423 goto out_set_bit; 424 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 425 (si->ksi_flags & KSI_SIGQ) == 0) { 426 SIGADDSET(sq->sq_kill, signo); 427 ret = 0; 428 goto out_set_bit; 429 } 430 return (ret); 431 } 432 433 out_set_bit: 434 SIGADDSET(sq->sq_signals, signo); 435 return (ret); 436 } 437 438 void 439 sigqueue_flush(sigqueue_t *sq) 440 { 441 struct proc *p = sq->sq_proc; 442 ksiginfo_t *ksi; 443 444 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 445 446 if (p != NULL) 447 PROC_LOCK_ASSERT(p, MA_OWNED); 448 449 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 450 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = NULL; 452 if (ksiginfo_tryfree(ksi) && p != NULL) 453 p->p_pendingcnt--; 454 } 455 456 SIGEMPTYSET(sq->sq_signals); 457 SIGEMPTYSET(sq->sq_kill); 458 SIGEMPTYSET(sq->sq_ptrace); 459 } 460 461 static void 462 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 463 { 464 sigset_t tmp; 465 struct proc *p1, *p2; 466 ksiginfo_t *ksi, *next; 467 468 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 469 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 470 p1 = src->sq_proc; 471 p2 = dst->sq_proc; 472 /* Move siginfo to target list */ 473 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 474 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 475 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 476 if (p1 != NULL) 477 p1->p_pendingcnt--; 478 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 479 ksi->ksi_sigq = dst; 480 if (p2 != NULL) 481 p2->p_pendingcnt++; 482 } 483 } 484 485 /* Move pending bits to target list */ 486 tmp = src->sq_kill; 487 SIGSETAND(tmp, *set); 488 SIGSETOR(dst->sq_kill, tmp); 489 SIGSETNAND(src->sq_kill, tmp); 490 491 tmp = src->sq_ptrace; 492 SIGSETAND(tmp, *set); 493 SIGSETOR(dst->sq_ptrace, tmp); 494 SIGSETNAND(src->sq_ptrace, tmp); 495 496 tmp = src->sq_signals; 497 SIGSETAND(tmp, *set); 498 SIGSETOR(dst->sq_signals, tmp); 499 SIGSETNAND(src->sq_signals, tmp); 500 } 501 502 #if 0 503 static void 504 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 505 { 506 sigset_t set; 507 508 SIGEMPTYSET(set); 509 SIGADDSET(set, signo); 510 sigqueue_move_set(src, dst, &set); 511 } 512 #endif 513 514 static void 515 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 516 { 517 struct proc *p = sq->sq_proc; 518 ksiginfo_t *ksi, *next; 519 520 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 521 522 /* Remove siginfo queue */ 523 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 524 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 525 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 526 ksi->ksi_sigq = NULL; 527 if (ksiginfo_tryfree(ksi) && p != NULL) 528 p->p_pendingcnt--; 529 } 530 } 531 SIGSETNAND(sq->sq_kill, *set); 532 SIGSETNAND(sq->sq_ptrace, *set); 533 SIGSETNAND(sq->sq_signals, *set); 534 } 535 536 void 537 sigqueue_delete(sigqueue_t *sq, int signo) 538 { 539 sigset_t set; 540 541 SIGEMPTYSET(set); 542 SIGADDSET(set, signo); 543 sigqueue_delete_set(sq, &set); 544 } 545 546 /* Remove a set of signals for a process */ 547 static void 548 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 549 { 550 sigqueue_t worklist; 551 struct thread *td0; 552 553 PROC_LOCK_ASSERT(p, MA_OWNED); 554 555 sigqueue_init(&worklist, NULL); 556 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 557 558 FOREACH_THREAD_IN_PROC(p, td0) 559 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 560 561 sigqueue_flush(&worklist); 562 } 563 564 void 565 sigqueue_delete_proc(struct proc *p, int signo) 566 { 567 sigset_t set; 568 569 SIGEMPTYSET(set); 570 SIGADDSET(set, signo); 571 sigqueue_delete_set_proc(p, &set); 572 } 573 574 static void 575 sigqueue_delete_stopmask_proc(struct proc *p) 576 { 577 sigset_t set; 578 579 SIGEMPTYSET(set); 580 SIGADDSET(set, SIGSTOP); 581 SIGADDSET(set, SIGTSTP); 582 SIGADDSET(set, SIGTTIN); 583 SIGADDSET(set, SIGTTOU); 584 sigqueue_delete_set_proc(p, &set); 585 } 586 587 /* 588 * Determine signal that should be delivered to thread td, the current 589 * thread, 0 if none. If there is a pending stop signal with default 590 * action, the process stops in issignal(). 591 */ 592 int 593 cursig(struct thread *td) 594 { 595 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 596 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 597 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 598 return (SIGPENDING(td) ? issignal(td) : 0); 599 } 600 601 /* 602 * Arrange for ast() to handle unmasked pending signals on return to user 603 * mode. This must be called whenever a signal is added to td_sigqueue or 604 * unmasked in td_sigmask. 605 */ 606 void 607 signotify(struct thread *td) 608 { 609 struct proc *p; 610 611 p = td->td_proc; 612 613 PROC_LOCK_ASSERT(p, MA_OWNED); 614 615 if (SIGPENDING(td)) { 616 thread_lock(td); 617 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 618 thread_unlock(td); 619 } 620 } 621 622 int 623 sigonstack(size_t sp) 624 { 625 struct thread *td = curthread; 626 627 return ((td->td_pflags & TDP_ALTSTACK) ? 628 #if defined(COMPAT_43) 629 ((td->td_sigstk.ss_size == 0) ? 630 (td->td_sigstk.ss_flags & SS_ONSTACK) : 631 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 632 #else 633 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 634 #endif 635 : 0); 636 } 637 638 static __inline int 639 sigprop(int sig) 640 { 641 642 if (sig > 0 && sig < nitems(sigproptbl)) 643 return (sigproptbl[sig]); 644 return (0); 645 } 646 647 int 648 sig_ffs(sigset_t *set) 649 { 650 int i; 651 652 for (i = 0; i < _SIG_WORDS; i++) 653 if (set->__bits[i]) 654 return (ffs(set->__bits[i]) + (i * 32)); 655 return (0); 656 } 657 658 static bool 659 sigact_flag_test(const struct sigaction *act, int flag) 660 { 661 662 /* 663 * SA_SIGINFO is reset when signal disposition is set to 664 * ignore or default. Other flags are kept according to user 665 * settings. 666 */ 667 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 668 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 669 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 670 } 671 672 /* 673 * kern_sigaction 674 * sigaction 675 * freebsd4_sigaction 676 * osigaction 677 */ 678 int 679 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 680 struct sigaction *oact, int flags) 681 { 682 struct sigacts *ps; 683 struct proc *p = td->td_proc; 684 685 if (!_SIG_VALID(sig)) 686 return (EINVAL); 687 if (act != NULL && act->sa_handler != SIG_DFL && 688 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 689 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 690 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 691 return (EINVAL); 692 693 PROC_LOCK(p); 694 ps = p->p_sigacts; 695 mtx_lock(&ps->ps_mtx); 696 if (oact) { 697 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 698 oact->sa_flags = 0; 699 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 700 oact->sa_flags |= SA_ONSTACK; 701 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 702 oact->sa_flags |= SA_RESTART; 703 if (SIGISMEMBER(ps->ps_sigreset, sig)) 704 oact->sa_flags |= SA_RESETHAND; 705 if (SIGISMEMBER(ps->ps_signodefer, sig)) 706 oact->sa_flags |= SA_NODEFER; 707 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 708 oact->sa_flags |= SA_SIGINFO; 709 oact->sa_sigaction = 710 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 711 } else 712 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 713 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 714 oact->sa_flags |= SA_NOCLDSTOP; 715 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 716 oact->sa_flags |= SA_NOCLDWAIT; 717 } 718 if (act) { 719 if ((sig == SIGKILL || sig == SIGSTOP) && 720 act->sa_handler != SIG_DFL) { 721 mtx_unlock(&ps->ps_mtx); 722 PROC_UNLOCK(p); 723 return (EINVAL); 724 } 725 726 /* 727 * Change setting atomically. 728 */ 729 730 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 731 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 732 if (sigact_flag_test(act, SA_SIGINFO)) { 733 ps->ps_sigact[_SIG_IDX(sig)] = 734 (__sighandler_t *)act->sa_sigaction; 735 SIGADDSET(ps->ps_siginfo, sig); 736 } else { 737 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 738 SIGDELSET(ps->ps_siginfo, sig); 739 } 740 if (!sigact_flag_test(act, SA_RESTART)) 741 SIGADDSET(ps->ps_sigintr, sig); 742 else 743 SIGDELSET(ps->ps_sigintr, sig); 744 if (sigact_flag_test(act, SA_ONSTACK)) 745 SIGADDSET(ps->ps_sigonstack, sig); 746 else 747 SIGDELSET(ps->ps_sigonstack, sig); 748 if (sigact_flag_test(act, SA_RESETHAND)) 749 SIGADDSET(ps->ps_sigreset, sig); 750 else 751 SIGDELSET(ps->ps_sigreset, sig); 752 if (sigact_flag_test(act, SA_NODEFER)) 753 SIGADDSET(ps->ps_signodefer, sig); 754 else 755 SIGDELSET(ps->ps_signodefer, sig); 756 if (sig == SIGCHLD) { 757 if (act->sa_flags & SA_NOCLDSTOP) 758 ps->ps_flag |= PS_NOCLDSTOP; 759 else 760 ps->ps_flag &= ~PS_NOCLDSTOP; 761 if (act->sa_flags & SA_NOCLDWAIT) { 762 /* 763 * Paranoia: since SA_NOCLDWAIT is implemented 764 * by reparenting the dying child to PID 1 (and 765 * trust it to reap the zombie), PID 1 itself 766 * is forbidden to set SA_NOCLDWAIT. 767 */ 768 if (p->p_pid == 1) 769 ps->ps_flag &= ~PS_NOCLDWAIT; 770 else 771 ps->ps_flag |= PS_NOCLDWAIT; 772 } else 773 ps->ps_flag &= ~PS_NOCLDWAIT; 774 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 775 ps->ps_flag |= PS_CLDSIGIGN; 776 else 777 ps->ps_flag &= ~PS_CLDSIGIGN; 778 } 779 /* 780 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 781 * and for signals set to SIG_DFL where the default is to 782 * ignore. However, don't put SIGCONT in ps_sigignore, as we 783 * have to restart the process. 784 */ 785 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 786 (sigprop(sig) & SIGPROP_IGNORE && 787 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 788 /* never to be seen again */ 789 sigqueue_delete_proc(p, sig); 790 if (sig != SIGCONT) 791 /* easier in psignal */ 792 SIGADDSET(ps->ps_sigignore, sig); 793 SIGDELSET(ps->ps_sigcatch, sig); 794 } else { 795 SIGDELSET(ps->ps_sigignore, sig); 796 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 797 SIGDELSET(ps->ps_sigcatch, sig); 798 else 799 SIGADDSET(ps->ps_sigcatch, sig); 800 } 801 #ifdef COMPAT_FREEBSD4 802 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 803 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 804 (flags & KSA_FREEBSD4) == 0) 805 SIGDELSET(ps->ps_freebsd4, sig); 806 else 807 SIGADDSET(ps->ps_freebsd4, sig); 808 #endif 809 #ifdef COMPAT_43 810 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 811 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 812 (flags & KSA_OSIGSET) == 0) 813 SIGDELSET(ps->ps_osigset, sig); 814 else 815 SIGADDSET(ps->ps_osigset, sig); 816 #endif 817 } 818 mtx_unlock(&ps->ps_mtx); 819 PROC_UNLOCK(p); 820 return (0); 821 } 822 823 #ifndef _SYS_SYSPROTO_H_ 824 struct sigaction_args { 825 int sig; 826 struct sigaction *act; 827 struct sigaction *oact; 828 }; 829 #endif 830 int 831 sys_sigaction(struct thread *td, struct sigaction_args *uap) 832 { 833 struct sigaction act, oact; 834 struct sigaction *actp, *oactp; 835 int error; 836 837 actp = (uap->act != NULL) ? &act : NULL; 838 oactp = (uap->oact != NULL) ? &oact : NULL; 839 if (actp) { 840 error = copyin(uap->act, actp, sizeof(act)); 841 if (error) 842 return (error); 843 } 844 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 845 if (oactp && !error) 846 error = copyout(oactp, uap->oact, sizeof(oact)); 847 return (error); 848 } 849 850 #ifdef COMPAT_FREEBSD4 851 #ifndef _SYS_SYSPROTO_H_ 852 struct freebsd4_sigaction_args { 853 int sig; 854 struct sigaction *act; 855 struct sigaction *oact; 856 }; 857 #endif 858 int 859 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 860 { 861 struct sigaction act, oact; 862 struct sigaction *actp, *oactp; 863 int error; 864 865 866 actp = (uap->act != NULL) ? &act : NULL; 867 oactp = (uap->oact != NULL) ? &oact : NULL; 868 if (actp) { 869 error = copyin(uap->act, actp, sizeof(act)); 870 if (error) 871 return (error); 872 } 873 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 874 if (oactp && !error) 875 error = copyout(oactp, uap->oact, sizeof(oact)); 876 return (error); 877 } 878 #endif /* COMAPT_FREEBSD4 */ 879 880 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 881 #ifndef _SYS_SYSPROTO_H_ 882 struct osigaction_args { 883 int signum; 884 struct osigaction *nsa; 885 struct osigaction *osa; 886 }; 887 #endif 888 int 889 osigaction(struct thread *td, struct osigaction_args *uap) 890 { 891 struct osigaction sa; 892 struct sigaction nsa, osa; 893 struct sigaction *nsap, *osap; 894 int error; 895 896 if (uap->signum <= 0 || uap->signum >= ONSIG) 897 return (EINVAL); 898 899 nsap = (uap->nsa != NULL) ? &nsa : NULL; 900 osap = (uap->osa != NULL) ? &osa : NULL; 901 902 if (nsap) { 903 error = copyin(uap->nsa, &sa, sizeof(sa)); 904 if (error) 905 return (error); 906 nsap->sa_handler = sa.sa_handler; 907 nsap->sa_flags = sa.sa_flags; 908 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 909 } 910 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 911 if (osap && !error) { 912 sa.sa_handler = osap->sa_handler; 913 sa.sa_flags = osap->sa_flags; 914 SIG2OSIG(osap->sa_mask, sa.sa_mask); 915 error = copyout(&sa, uap->osa, sizeof(sa)); 916 } 917 return (error); 918 } 919 920 #if !defined(__i386__) 921 /* Avoid replicating the same stub everywhere */ 922 int 923 osigreturn(struct thread *td, struct osigreturn_args *uap) 924 { 925 926 return (nosys(td, (struct nosys_args *)uap)); 927 } 928 #endif 929 #endif /* COMPAT_43 */ 930 931 /* 932 * Initialize signal state for process 0; 933 * set to ignore signals that are ignored by default. 934 */ 935 void 936 siginit(struct proc *p) 937 { 938 int i; 939 struct sigacts *ps; 940 941 PROC_LOCK(p); 942 ps = p->p_sigacts; 943 mtx_lock(&ps->ps_mtx); 944 for (i = 1; i <= NSIG; i++) { 945 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 946 SIGADDSET(ps->ps_sigignore, i); 947 } 948 } 949 mtx_unlock(&ps->ps_mtx); 950 PROC_UNLOCK(p); 951 } 952 953 /* 954 * Reset specified signal to the default disposition. 955 */ 956 static void 957 sigdflt(struct sigacts *ps, int sig) 958 { 959 960 mtx_assert(&ps->ps_mtx, MA_OWNED); 961 SIGDELSET(ps->ps_sigcatch, sig); 962 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 963 SIGADDSET(ps->ps_sigignore, sig); 964 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 965 SIGDELSET(ps->ps_siginfo, sig); 966 } 967 968 /* 969 * Reset signals for an exec of the specified process. 970 */ 971 void 972 execsigs(struct proc *p) 973 { 974 sigset_t osigignore; 975 struct sigacts *ps; 976 int sig; 977 struct thread *td; 978 979 /* 980 * Reset caught signals. Held signals remain held 981 * through td_sigmask (unless they were caught, 982 * and are now ignored by default). 983 */ 984 PROC_LOCK_ASSERT(p, MA_OWNED); 985 ps = p->p_sigacts; 986 mtx_lock(&ps->ps_mtx); 987 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 988 sig = sig_ffs(&ps->ps_sigcatch); 989 sigdflt(ps, sig); 990 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 991 sigqueue_delete_proc(p, sig); 992 } 993 994 /* 995 * As CloudABI processes cannot modify signal handlers, fully 996 * reset all signals to their default behavior. Do ignore 997 * SIGPIPE, as it would otherwise be impossible to recover from 998 * writes to broken pipes and sockets. 999 */ 1000 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1001 osigignore = ps->ps_sigignore; 1002 while (SIGNOTEMPTY(osigignore)) { 1003 sig = sig_ffs(&osigignore); 1004 SIGDELSET(osigignore, sig); 1005 if (sig != SIGPIPE) 1006 sigdflt(ps, sig); 1007 } 1008 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1009 } 1010 1011 /* 1012 * Reset stack state to the user stack. 1013 * Clear set of signals caught on the signal stack. 1014 */ 1015 td = curthread; 1016 MPASS(td->td_proc == p); 1017 td->td_sigstk.ss_flags = SS_DISABLE; 1018 td->td_sigstk.ss_size = 0; 1019 td->td_sigstk.ss_sp = 0; 1020 td->td_pflags &= ~TDP_ALTSTACK; 1021 /* 1022 * Reset no zombies if child dies flag as Solaris does. 1023 */ 1024 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1025 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1026 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1027 mtx_unlock(&ps->ps_mtx); 1028 } 1029 1030 /* 1031 * kern_sigprocmask() 1032 * 1033 * Manipulate signal mask. 1034 */ 1035 int 1036 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1037 int flags) 1038 { 1039 sigset_t new_block, oset1; 1040 struct proc *p; 1041 int error; 1042 1043 p = td->td_proc; 1044 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1045 PROC_LOCK_ASSERT(p, MA_OWNED); 1046 else 1047 PROC_LOCK(p); 1048 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1049 ? MA_OWNED : MA_NOTOWNED); 1050 if (oset != NULL) 1051 *oset = td->td_sigmask; 1052 1053 error = 0; 1054 if (set != NULL) { 1055 switch (how) { 1056 case SIG_BLOCK: 1057 SIG_CANTMASK(*set); 1058 oset1 = td->td_sigmask; 1059 SIGSETOR(td->td_sigmask, *set); 1060 new_block = td->td_sigmask; 1061 SIGSETNAND(new_block, oset1); 1062 break; 1063 case SIG_UNBLOCK: 1064 SIGSETNAND(td->td_sigmask, *set); 1065 signotify(td); 1066 goto out; 1067 case SIG_SETMASK: 1068 SIG_CANTMASK(*set); 1069 oset1 = td->td_sigmask; 1070 if (flags & SIGPROCMASK_OLD) 1071 SIGSETLO(td->td_sigmask, *set); 1072 else 1073 td->td_sigmask = *set; 1074 new_block = td->td_sigmask; 1075 SIGSETNAND(new_block, oset1); 1076 signotify(td); 1077 break; 1078 default: 1079 error = EINVAL; 1080 goto out; 1081 } 1082 1083 /* 1084 * The new_block set contains signals that were not previously 1085 * blocked, but are blocked now. 1086 * 1087 * In case we block any signal that was not previously blocked 1088 * for td, and process has the signal pending, try to schedule 1089 * signal delivery to some thread that does not block the 1090 * signal, possibly waking it up. 1091 */ 1092 if (p->p_numthreads != 1) 1093 reschedule_signals(p, new_block, flags); 1094 } 1095 1096 out: 1097 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1098 PROC_UNLOCK(p); 1099 return (error); 1100 } 1101 1102 #ifndef _SYS_SYSPROTO_H_ 1103 struct sigprocmask_args { 1104 int how; 1105 const sigset_t *set; 1106 sigset_t *oset; 1107 }; 1108 #endif 1109 int 1110 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1111 { 1112 sigset_t set, oset; 1113 sigset_t *setp, *osetp; 1114 int error; 1115 1116 setp = (uap->set != NULL) ? &set : NULL; 1117 osetp = (uap->oset != NULL) ? &oset : NULL; 1118 if (setp) { 1119 error = copyin(uap->set, setp, sizeof(set)); 1120 if (error) 1121 return (error); 1122 } 1123 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1124 if (osetp && !error) { 1125 error = copyout(osetp, uap->oset, sizeof(oset)); 1126 } 1127 return (error); 1128 } 1129 1130 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1131 #ifndef _SYS_SYSPROTO_H_ 1132 struct osigprocmask_args { 1133 int how; 1134 osigset_t mask; 1135 }; 1136 #endif 1137 int 1138 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1139 { 1140 sigset_t set, oset; 1141 int error; 1142 1143 OSIG2SIG(uap->mask, set); 1144 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1145 SIG2OSIG(oset, td->td_retval[0]); 1146 return (error); 1147 } 1148 #endif /* COMPAT_43 */ 1149 1150 int 1151 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1152 { 1153 ksiginfo_t ksi; 1154 sigset_t set; 1155 int error; 1156 1157 error = copyin(uap->set, &set, sizeof(set)); 1158 if (error) { 1159 td->td_retval[0] = error; 1160 return (0); 1161 } 1162 1163 error = kern_sigtimedwait(td, set, &ksi, NULL); 1164 if (error) { 1165 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1166 error = ERESTART; 1167 if (error == ERESTART) 1168 return (error); 1169 td->td_retval[0] = error; 1170 return (0); 1171 } 1172 1173 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1174 td->td_retval[0] = error; 1175 return (0); 1176 } 1177 1178 int 1179 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1180 { 1181 struct timespec ts; 1182 struct timespec *timeout; 1183 sigset_t set; 1184 ksiginfo_t ksi; 1185 int error; 1186 1187 if (uap->timeout) { 1188 error = copyin(uap->timeout, &ts, sizeof(ts)); 1189 if (error) 1190 return (error); 1191 1192 timeout = &ts; 1193 } else 1194 timeout = NULL; 1195 1196 error = copyin(uap->set, &set, sizeof(set)); 1197 if (error) 1198 return (error); 1199 1200 error = kern_sigtimedwait(td, set, &ksi, timeout); 1201 if (error) 1202 return (error); 1203 1204 if (uap->info) 1205 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1206 1207 if (error == 0) 1208 td->td_retval[0] = ksi.ksi_signo; 1209 return (error); 1210 } 1211 1212 int 1213 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1214 { 1215 ksiginfo_t ksi; 1216 sigset_t set; 1217 int error; 1218 1219 error = copyin(uap->set, &set, sizeof(set)); 1220 if (error) 1221 return (error); 1222 1223 error = kern_sigtimedwait(td, set, &ksi, NULL); 1224 if (error) 1225 return (error); 1226 1227 if (uap->info) 1228 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1229 1230 if (error == 0) 1231 td->td_retval[0] = ksi.ksi_signo; 1232 return (error); 1233 } 1234 1235 static void 1236 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1237 { 1238 struct thread *thr; 1239 1240 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1241 if (thr == td) 1242 thr->td_si = *si; 1243 else 1244 thr->td_si.si_signo = 0; 1245 } 1246 } 1247 1248 int 1249 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1250 struct timespec *timeout) 1251 { 1252 struct sigacts *ps; 1253 sigset_t saved_mask, new_block; 1254 struct proc *p; 1255 int error, sig, timo, timevalid = 0; 1256 struct timespec rts, ets, ts; 1257 struct timeval tv; 1258 1259 p = td->td_proc; 1260 error = 0; 1261 ets.tv_sec = 0; 1262 ets.tv_nsec = 0; 1263 1264 if (timeout != NULL) { 1265 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1266 timevalid = 1; 1267 getnanouptime(&rts); 1268 ets = rts; 1269 timespecadd(&ets, timeout); 1270 } 1271 } 1272 ksiginfo_init(ksi); 1273 /* Some signals can not be waited for. */ 1274 SIG_CANTMASK(waitset); 1275 ps = p->p_sigacts; 1276 PROC_LOCK(p); 1277 saved_mask = td->td_sigmask; 1278 SIGSETNAND(td->td_sigmask, waitset); 1279 for (;;) { 1280 mtx_lock(&ps->ps_mtx); 1281 sig = cursig(td); 1282 mtx_unlock(&ps->ps_mtx); 1283 KASSERT(sig >= 0, ("sig %d", sig)); 1284 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1285 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1286 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1287 error = 0; 1288 break; 1289 } 1290 } 1291 1292 if (error != 0) 1293 break; 1294 1295 /* 1296 * POSIX says this must be checked after looking for pending 1297 * signals. 1298 */ 1299 if (timeout != NULL) { 1300 if (!timevalid) { 1301 error = EINVAL; 1302 break; 1303 } 1304 getnanouptime(&rts); 1305 if (timespeccmp(&rts, &ets, >=)) { 1306 error = EAGAIN; 1307 break; 1308 } 1309 ts = ets; 1310 timespecsub(&ts, &rts); 1311 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1312 timo = tvtohz(&tv); 1313 } else { 1314 timo = 0; 1315 } 1316 1317 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1318 1319 if (timeout != NULL) { 1320 if (error == ERESTART) { 1321 /* Timeout can not be restarted. */ 1322 error = EINTR; 1323 } else if (error == EAGAIN) { 1324 /* We will calculate timeout by ourself. */ 1325 error = 0; 1326 } 1327 } 1328 } 1329 1330 new_block = saved_mask; 1331 SIGSETNAND(new_block, td->td_sigmask); 1332 td->td_sigmask = saved_mask; 1333 /* 1334 * Fewer signals can be delivered to us, reschedule signal 1335 * notification. 1336 */ 1337 if (p->p_numthreads != 1) 1338 reschedule_signals(p, new_block, 0); 1339 1340 if (error == 0) { 1341 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1342 1343 if (ksi->ksi_code == SI_TIMER) 1344 itimer_accept(p, ksi->ksi_timerid, ksi); 1345 1346 #ifdef KTRACE 1347 if (KTRPOINT(td, KTR_PSIG)) { 1348 sig_t action; 1349 1350 mtx_lock(&ps->ps_mtx); 1351 action = ps->ps_sigact[_SIG_IDX(sig)]; 1352 mtx_unlock(&ps->ps_mtx); 1353 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1354 } 1355 #endif 1356 if (sig == SIGKILL) { 1357 proc_td_siginfo_capture(td, &ksi->ksi_info); 1358 sigexit(td, sig); 1359 } 1360 } 1361 PROC_UNLOCK(p); 1362 return (error); 1363 } 1364 1365 #ifndef _SYS_SYSPROTO_H_ 1366 struct sigpending_args { 1367 sigset_t *set; 1368 }; 1369 #endif 1370 int 1371 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1372 { 1373 struct proc *p = td->td_proc; 1374 sigset_t pending; 1375 1376 PROC_LOCK(p); 1377 pending = p->p_sigqueue.sq_signals; 1378 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1379 PROC_UNLOCK(p); 1380 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1381 } 1382 1383 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1384 #ifndef _SYS_SYSPROTO_H_ 1385 struct osigpending_args { 1386 int dummy; 1387 }; 1388 #endif 1389 int 1390 osigpending(struct thread *td, struct osigpending_args *uap) 1391 { 1392 struct proc *p = td->td_proc; 1393 sigset_t pending; 1394 1395 PROC_LOCK(p); 1396 pending = p->p_sigqueue.sq_signals; 1397 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1398 PROC_UNLOCK(p); 1399 SIG2OSIG(pending, td->td_retval[0]); 1400 return (0); 1401 } 1402 #endif /* COMPAT_43 */ 1403 1404 #if defined(COMPAT_43) 1405 /* 1406 * Generalized interface signal handler, 4.3-compatible. 1407 */ 1408 #ifndef _SYS_SYSPROTO_H_ 1409 struct osigvec_args { 1410 int signum; 1411 struct sigvec *nsv; 1412 struct sigvec *osv; 1413 }; 1414 #endif 1415 /* ARGSUSED */ 1416 int 1417 osigvec(struct thread *td, struct osigvec_args *uap) 1418 { 1419 struct sigvec vec; 1420 struct sigaction nsa, osa; 1421 struct sigaction *nsap, *osap; 1422 int error; 1423 1424 if (uap->signum <= 0 || uap->signum >= ONSIG) 1425 return (EINVAL); 1426 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1427 osap = (uap->osv != NULL) ? &osa : NULL; 1428 if (nsap) { 1429 error = copyin(uap->nsv, &vec, sizeof(vec)); 1430 if (error) 1431 return (error); 1432 nsap->sa_handler = vec.sv_handler; 1433 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1434 nsap->sa_flags = vec.sv_flags; 1435 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1436 } 1437 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1438 if (osap && !error) { 1439 vec.sv_handler = osap->sa_handler; 1440 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1441 vec.sv_flags = osap->sa_flags; 1442 vec.sv_flags &= ~SA_NOCLDWAIT; 1443 vec.sv_flags ^= SA_RESTART; 1444 error = copyout(&vec, uap->osv, sizeof(vec)); 1445 } 1446 return (error); 1447 } 1448 1449 #ifndef _SYS_SYSPROTO_H_ 1450 struct osigblock_args { 1451 int mask; 1452 }; 1453 #endif 1454 int 1455 osigblock(struct thread *td, struct osigblock_args *uap) 1456 { 1457 sigset_t set, oset; 1458 1459 OSIG2SIG(uap->mask, set); 1460 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1461 SIG2OSIG(oset, td->td_retval[0]); 1462 return (0); 1463 } 1464 1465 #ifndef _SYS_SYSPROTO_H_ 1466 struct osigsetmask_args { 1467 int mask; 1468 }; 1469 #endif 1470 int 1471 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1472 { 1473 sigset_t set, oset; 1474 1475 OSIG2SIG(uap->mask, set); 1476 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1477 SIG2OSIG(oset, td->td_retval[0]); 1478 return (0); 1479 } 1480 #endif /* COMPAT_43 */ 1481 1482 /* 1483 * Suspend calling thread until signal, providing mask to be set in the 1484 * meantime. 1485 */ 1486 #ifndef _SYS_SYSPROTO_H_ 1487 struct sigsuspend_args { 1488 const sigset_t *sigmask; 1489 }; 1490 #endif 1491 /* ARGSUSED */ 1492 int 1493 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1494 { 1495 sigset_t mask; 1496 int error; 1497 1498 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1499 if (error) 1500 return (error); 1501 return (kern_sigsuspend(td, mask)); 1502 } 1503 1504 int 1505 kern_sigsuspend(struct thread *td, sigset_t mask) 1506 { 1507 struct proc *p = td->td_proc; 1508 int has_sig, sig; 1509 1510 /* 1511 * When returning from sigsuspend, we want 1512 * the old mask to be restored after the 1513 * signal handler has finished. Thus, we 1514 * save it here and mark the sigacts structure 1515 * to indicate this. 1516 */ 1517 PROC_LOCK(p); 1518 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1519 SIGPROCMASK_PROC_LOCKED); 1520 td->td_pflags |= TDP_OLDMASK; 1521 1522 /* 1523 * Process signals now. Otherwise, we can get spurious wakeup 1524 * due to signal entered process queue, but delivered to other 1525 * thread. But sigsuspend should return only on signal 1526 * delivery. 1527 */ 1528 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1529 for (has_sig = 0; !has_sig;) { 1530 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1531 0) == 0) 1532 /* void */; 1533 thread_suspend_check(0); 1534 mtx_lock(&p->p_sigacts->ps_mtx); 1535 while ((sig = cursig(td)) != 0) { 1536 KASSERT(sig >= 0, ("sig %d", sig)); 1537 has_sig += postsig(sig); 1538 } 1539 mtx_unlock(&p->p_sigacts->ps_mtx); 1540 } 1541 PROC_UNLOCK(p); 1542 td->td_errno = EINTR; 1543 td->td_pflags |= TDP_NERRNO; 1544 return (EJUSTRETURN); 1545 } 1546 1547 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1548 /* 1549 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1550 * convention: libc stub passes mask, not pointer, to save a copyin. 1551 */ 1552 #ifndef _SYS_SYSPROTO_H_ 1553 struct osigsuspend_args { 1554 osigset_t mask; 1555 }; 1556 #endif 1557 /* ARGSUSED */ 1558 int 1559 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1560 { 1561 sigset_t mask; 1562 1563 OSIG2SIG(uap->mask, mask); 1564 return (kern_sigsuspend(td, mask)); 1565 } 1566 #endif /* COMPAT_43 */ 1567 1568 #if defined(COMPAT_43) 1569 #ifndef _SYS_SYSPROTO_H_ 1570 struct osigstack_args { 1571 struct sigstack *nss; 1572 struct sigstack *oss; 1573 }; 1574 #endif 1575 /* ARGSUSED */ 1576 int 1577 osigstack(struct thread *td, struct osigstack_args *uap) 1578 { 1579 struct sigstack nss, oss; 1580 int error = 0; 1581 1582 if (uap->nss != NULL) { 1583 error = copyin(uap->nss, &nss, sizeof(nss)); 1584 if (error) 1585 return (error); 1586 } 1587 oss.ss_sp = td->td_sigstk.ss_sp; 1588 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1589 if (uap->nss != NULL) { 1590 td->td_sigstk.ss_sp = nss.ss_sp; 1591 td->td_sigstk.ss_size = 0; 1592 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1593 td->td_pflags |= TDP_ALTSTACK; 1594 } 1595 if (uap->oss != NULL) 1596 error = copyout(&oss, uap->oss, sizeof(oss)); 1597 1598 return (error); 1599 } 1600 #endif /* COMPAT_43 */ 1601 1602 #ifndef _SYS_SYSPROTO_H_ 1603 struct sigaltstack_args { 1604 stack_t *ss; 1605 stack_t *oss; 1606 }; 1607 #endif 1608 /* ARGSUSED */ 1609 int 1610 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1611 { 1612 stack_t ss, oss; 1613 int error; 1614 1615 if (uap->ss != NULL) { 1616 error = copyin(uap->ss, &ss, sizeof(ss)); 1617 if (error) 1618 return (error); 1619 } 1620 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1621 (uap->oss != NULL) ? &oss : NULL); 1622 if (error) 1623 return (error); 1624 if (uap->oss != NULL) 1625 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1626 return (error); 1627 } 1628 1629 int 1630 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1631 { 1632 struct proc *p = td->td_proc; 1633 int oonstack; 1634 1635 oonstack = sigonstack(cpu_getstack(td)); 1636 1637 if (oss != NULL) { 1638 *oss = td->td_sigstk; 1639 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1640 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1641 } 1642 1643 if (ss != NULL) { 1644 if (oonstack) 1645 return (EPERM); 1646 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1647 return (EINVAL); 1648 if (!(ss->ss_flags & SS_DISABLE)) { 1649 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1650 return (ENOMEM); 1651 1652 td->td_sigstk = *ss; 1653 td->td_pflags |= TDP_ALTSTACK; 1654 } else { 1655 td->td_pflags &= ~TDP_ALTSTACK; 1656 } 1657 } 1658 return (0); 1659 } 1660 1661 /* 1662 * Common code for kill process group/broadcast kill. 1663 * cp is calling process. 1664 */ 1665 static int 1666 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1667 { 1668 struct proc *p; 1669 struct pgrp *pgrp; 1670 int err; 1671 int ret; 1672 1673 ret = ESRCH; 1674 if (all) { 1675 /* 1676 * broadcast 1677 */ 1678 sx_slock(&allproc_lock); 1679 FOREACH_PROC_IN_SYSTEM(p) { 1680 PROC_LOCK(p); 1681 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1682 p == td->td_proc || p->p_state == PRS_NEW) { 1683 PROC_UNLOCK(p); 1684 continue; 1685 } 1686 err = p_cansignal(td, p, sig); 1687 if (err == 0) { 1688 if (sig) 1689 pksignal(p, sig, ksi); 1690 ret = err; 1691 } 1692 else if (ret == ESRCH) 1693 ret = err; 1694 PROC_UNLOCK(p); 1695 } 1696 sx_sunlock(&allproc_lock); 1697 } else { 1698 sx_slock(&proctree_lock); 1699 if (pgid == 0) { 1700 /* 1701 * zero pgid means send to my process group. 1702 */ 1703 pgrp = td->td_proc->p_pgrp; 1704 PGRP_LOCK(pgrp); 1705 } else { 1706 pgrp = pgfind(pgid); 1707 if (pgrp == NULL) { 1708 sx_sunlock(&proctree_lock); 1709 return (ESRCH); 1710 } 1711 } 1712 sx_sunlock(&proctree_lock); 1713 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1714 PROC_LOCK(p); 1715 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1716 p->p_state == PRS_NEW) { 1717 PROC_UNLOCK(p); 1718 continue; 1719 } 1720 err = p_cansignal(td, p, sig); 1721 if (err == 0) { 1722 if (sig) 1723 pksignal(p, sig, ksi); 1724 ret = err; 1725 } 1726 else if (ret == ESRCH) 1727 ret = err; 1728 PROC_UNLOCK(p); 1729 } 1730 PGRP_UNLOCK(pgrp); 1731 } 1732 return (ret); 1733 } 1734 1735 #ifndef _SYS_SYSPROTO_H_ 1736 struct kill_args { 1737 int pid; 1738 int signum; 1739 }; 1740 #endif 1741 /* ARGSUSED */ 1742 int 1743 sys_kill(struct thread *td, struct kill_args *uap) 1744 { 1745 ksiginfo_t ksi; 1746 struct proc *p; 1747 int error; 1748 1749 /* 1750 * A process in capability mode can send signals only to himself. 1751 * The main rationale behind this is that abort(3) is implemented as 1752 * kill(getpid(), SIGABRT). 1753 */ 1754 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1755 return (ECAPMODE); 1756 1757 AUDIT_ARG_SIGNUM(uap->signum); 1758 AUDIT_ARG_PID(uap->pid); 1759 if ((u_int)uap->signum > _SIG_MAXSIG) 1760 return (EINVAL); 1761 1762 ksiginfo_init(&ksi); 1763 ksi.ksi_signo = uap->signum; 1764 ksi.ksi_code = SI_USER; 1765 ksi.ksi_pid = td->td_proc->p_pid; 1766 ksi.ksi_uid = td->td_ucred->cr_ruid; 1767 1768 if (uap->pid > 0) { 1769 /* kill single process */ 1770 if ((p = pfind_any(uap->pid)) == NULL) 1771 return (ESRCH); 1772 AUDIT_ARG_PROCESS(p); 1773 error = p_cansignal(td, p, uap->signum); 1774 if (error == 0 && uap->signum) 1775 pksignal(p, uap->signum, &ksi); 1776 PROC_UNLOCK(p); 1777 return (error); 1778 } 1779 switch (uap->pid) { 1780 case -1: /* broadcast signal */ 1781 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1782 case 0: /* signal own process group */ 1783 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1784 default: /* negative explicit process group */ 1785 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1786 } 1787 /* NOTREACHED */ 1788 } 1789 1790 int 1791 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1792 { 1793 struct proc *p; 1794 cap_rights_t rights; 1795 int error; 1796 1797 AUDIT_ARG_SIGNUM(uap->signum); 1798 AUDIT_ARG_FD(uap->fd); 1799 if ((u_int)uap->signum > _SIG_MAXSIG) 1800 return (EINVAL); 1801 1802 error = procdesc_find(td, uap->fd, 1803 cap_rights_init(&rights, CAP_PDKILL), &p); 1804 if (error) 1805 return (error); 1806 AUDIT_ARG_PROCESS(p); 1807 error = p_cansignal(td, p, uap->signum); 1808 if (error == 0 && uap->signum) 1809 kern_psignal(p, uap->signum); 1810 PROC_UNLOCK(p); 1811 return (error); 1812 } 1813 1814 #if defined(COMPAT_43) 1815 #ifndef _SYS_SYSPROTO_H_ 1816 struct okillpg_args { 1817 int pgid; 1818 int signum; 1819 }; 1820 #endif 1821 /* ARGSUSED */ 1822 int 1823 okillpg(struct thread *td, struct okillpg_args *uap) 1824 { 1825 ksiginfo_t ksi; 1826 1827 AUDIT_ARG_SIGNUM(uap->signum); 1828 AUDIT_ARG_PID(uap->pgid); 1829 if ((u_int)uap->signum > _SIG_MAXSIG) 1830 return (EINVAL); 1831 1832 ksiginfo_init(&ksi); 1833 ksi.ksi_signo = uap->signum; 1834 ksi.ksi_code = SI_USER; 1835 ksi.ksi_pid = td->td_proc->p_pid; 1836 ksi.ksi_uid = td->td_ucred->cr_ruid; 1837 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1838 } 1839 #endif /* COMPAT_43 */ 1840 1841 #ifndef _SYS_SYSPROTO_H_ 1842 struct sigqueue_args { 1843 pid_t pid; 1844 int signum; 1845 /* union sigval */ void *value; 1846 }; 1847 #endif 1848 int 1849 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1850 { 1851 union sigval sv; 1852 1853 sv.sival_ptr = uap->value; 1854 1855 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1856 } 1857 1858 int 1859 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1860 { 1861 ksiginfo_t ksi; 1862 struct proc *p; 1863 int error; 1864 1865 if ((u_int)signum > _SIG_MAXSIG) 1866 return (EINVAL); 1867 1868 /* 1869 * Specification says sigqueue can only send signal to 1870 * single process. 1871 */ 1872 if (pid <= 0) 1873 return (EINVAL); 1874 1875 if ((p = pfind_any(pid)) == NULL) 1876 return (ESRCH); 1877 error = p_cansignal(td, p, signum); 1878 if (error == 0 && signum != 0) { 1879 ksiginfo_init(&ksi); 1880 ksi.ksi_flags = KSI_SIGQ; 1881 ksi.ksi_signo = signum; 1882 ksi.ksi_code = SI_QUEUE; 1883 ksi.ksi_pid = td->td_proc->p_pid; 1884 ksi.ksi_uid = td->td_ucred->cr_ruid; 1885 ksi.ksi_value = *value; 1886 error = pksignal(p, ksi.ksi_signo, &ksi); 1887 } 1888 PROC_UNLOCK(p); 1889 return (error); 1890 } 1891 1892 /* 1893 * Send a signal to a process group. 1894 */ 1895 void 1896 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1897 { 1898 struct pgrp *pgrp; 1899 1900 if (pgid != 0) { 1901 sx_slock(&proctree_lock); 1902 pgrp = pgfind(pgid); 1903 sx_sunlock(&proctree_lock); 1904 if (pgrp != NULL) { 1905 pgsignal(pgrp, sig, 0, ksi); 1906 PGRP_UNLOCK(pgrp); 1907 } 1908 } 1909 } 1910 1911 /* 1912 * Send a signal to a process group. If checktty is 1, 1913 * limit to members which have a controlling terminal. 1914 */ 1915 void 1916 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1917 { 1918 struct proc *p; 1919 1920 if (pgrp) { 1921 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1922 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1923 PROC_LOCK(p); 1924 if (p->p_state == PRS_NORMAL && 1925 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1926 pksignal(p, sig, ksi); 1927 PROC_UNLOCK(p); 1928 } 1929 } 1930 } 1931 1932 1933 /* 1934 * Recalculate the signal mask and reset the signal disposition after 1935 * usermode frame for delivery is formed. Should be called after 1936 * mach-specific routine, because sysent->sv_sendsig() needs correct 1937 * ps_siginfo and signal mask. 1938 */ 1939 static void 1940 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1941 { 1942 sigset_t mask; 1943 1944 mtx_assert(&ps->ps_mtx, MA_OWNED); 1945 td->td_ru.ru_nsignals++; 1946 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1947 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1948 SIGADDSET(mask, sig); 1949 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1950 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1951 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1952 sigdflt(ps, sig); 1953 } 1954 1955 1956 /* 1957 * Send a signal caused by a trap to the current thread. If it will be 1958 * caught immediately, deliver it with correct code. Otherwise, post it 1959 * normally. 1960 */ 1961 void 1962 trapsignal(struct thread *td, ksiginfo_t *ksi) 1963 { 1964 struct sigacts *ps; 1965 struct proc *p; 1966 int sig; 1967 int code; 1968 1969 p = td->td_proc; 1970 sig = ksi->ksi_signo; 1971 code = ksi->ksi_code; 1972 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1973 1974 PROC_LOCK(p); 1975 ps = p->p_sigacts; 1976 mtx_lock(&ps->ps_mtx); 1977 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1978 !SIGISMEMBER(td->td_sigmask, sig)) { 1979 #ifdef KTRACE 1980 if (KTRPOINT(curthread, KTR_PSIG)) 1981 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1982 &td->td_sigmask, code); 1983 #endif 1984 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1985 ksi, &td->td_sigmask); 1986 postsig_done(sig, td, ps); 1987 mtx_unlock(&ps->ps_mtx); 1988 } else { 1989 /* 1990 * Avoid a possible infinite loop if the thread 1991 * masking the signal or process is ignoring the 1992 * signal. 1993 */ 1994 if (kern_forcesigexit && 1995 (SIGISMEMBER(td->td_sigmask, sig) || 1996 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1997 SIGDELSET(td->td_sigmask, sig); 1998 SIGDELSET(ps->ps_sigcatch, sig); 1999 SIGDELSET(ps->ps_sigignore, sig); 2000 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2001 } 2002 mtx_unlock(&ps->ps_mtx); 2003 p->p_code = code; /* XXX for core dump/debugger */ 2004 p->p_sig = sig; /* XXX to verify code */ 2005 tdsendsignal(p, td, sig, ksi); 2006 } 2007 PROC_UNLOCK(p); 2008 } 2009 2010 static struct thread * 2011 sigtd(struct proc *p, int sig, int prop) 2012 { 2013 struct thread *td, *signal_td; 2014 2015 PROC_LOCK_ASSERT(p, MA_OWNED); 2016 2017 /* 2018 * Check if current thread can handle the signal without 2019 * switching context to another thread. 2020 */ 2021 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2022 return (curthread); 2023 signal_td = NULL; 2024 FOREACH_THREAD_IN_PROC(p, td) { 2025 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2026 signal_td = td; 2027 break; 2028 } 2029 } 2030 if (signal_td == NULL) 2031 signal_td = FIRST_THREAD_IN_PROC(p); 2032 return (signal_td); 2033 } 2034 2035 /* 2036 * Send the signal to the process. If the signal has an action, the action 2037 * is usually performed by the target process rather than the caller; we add 2038 * the signal to the set of pending signals for the process. 2039 * 2040 * Exceptions: 2041 * o When a stop signal is sent to a sleeping process that takes the 2042 * default action, the process is stopped without awakening it. 2043 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2044 * regardless of the signal action (eg, blocked or ignored). 2045 * 2046 * Other ignored signals are discarded immediately. 2047 * 2048 * NB: This function may be entered from the debugger via the "kill" DDB 2049 * command. There is little that can be done to mitigate the possibly messy 2050 * side effects of this unwise possibility. 2051 */ 2052 void 2053 kern_psignal(struct proc *p, int sig) 2054 { 2055 ksiginfo_t ksi; 2056 2057 ksiginfo_init(&ksi); 2058 ksi.ksi_signo = sig; 2059 ksi.ksi_code = SI_KERNEL; 2060 (void) tdsendsignal(p, NULL, sig, &ksi); 2061 } 2062 2063 int 2064 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2065 { 2066 2067 return (tdsendsignal(p, NULL, sig, ksi)); 2068 } 2069 2070 /* Utility function for finding a thread to send signal event to. */ 2071 int 2072 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2073 { 2074 struct thread *td; 2075 2076 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2077 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2078 if (td == NULL) 2079 return (ESRCH); 2080 *ttd = td; 2081 } else { 2082 *ttd = NULL; 2083 PROC_LOCK(p); 2084 } 2085 return (0); 2086 } 2087 2088 void 2089 tdsignal(struct thread *td, int sig) 2090 { 2091 ksiginfo_t ksi; 2092 2093 ksiginfo_init(&ksi); 2094 ksi.ksi_signo = sig; 2095 ksi.ksi_code = SI_KERNEL; 2096 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2097 } 2098 2099 void 2100 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2101 { 2102 2103 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2104 } 2105 2106 int 2107 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2108 { 2109 sig_t action; 2110 sigqueue_t *sigqueue; 2111 int prop; 2112 struct sigacts *ps; 2113 int intrval; 2114 int ret = 0; 2115 int wakeup_swapper; 2116 2117 MPASS(td == NULL || p == td->td_proc); 2118 PROC_LOCK_ASSERT(p, MA_OWNED); 2119 2120 if (!_SIG_VALID(sig)) 2121 panic("%s(): invalid signal %d", __func__, sig); 2122 2123 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2124 2125 /* 2126 * IEEE Std 1003.1-2001: return success when killing a zombie. 2127 */ 2128 if (p->p_state == PRS_ZOMBIE) { 2129 if (ksi && (ksi->ksi_flags & KSI_INS)) 2130 ksiginfo_tryfree(ksi); 2131 return (ret); 2132 } 2133 2134 ps = p->p_sigacts; 2135 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2136 prop = sigprop(sig); 2137 2138 if (td == NULL) { 2139 td = sigtd(p, sig, prop); 2140 sigqueue = &p->p_sigqueue; 2141 } else 2142 sigqueue = &td->td_sigqueue; 2143 2144 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2145 2146 /* 2147 * If the signal is being ignored, 2148 * then we forget about it immediately. 2149 * (Note: we don't set SIGCONT in ps_sigignore, 2150 * and if it is set to SIG_IGN, 2151 * action will be SIG_DFL here.) 2152 */ 2153 mtx_lock(&ps->ps_mtx); 2154 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2155 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2156 2157 mtx_unlock(&ps->ps_mtx); 2158 if (ksi && (ksi->ksi_flags & KSI_INS)) 2159 ksiginfo_tryfree(ksi); 2160 return (ret); 2161 } 2162 if (SIGISMEMBER(td->td_sigmask, sig)) 2163 action = SIG_HOLD; 2164 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2165 action = SIG_CATCH; 2166 else 2167 action = SIG_DFL; 2168 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2169 intrval = EINTR; 2170 else 2171 intrval = ERESTART; 2172 mtx_unlock(&ps->ps_mtx); 2173 2174 if (prop & SIGPROP_CONT) 2175 sigqueue_delete_stopmask_proc(p); 2176 else if (prop & SIGPROP_STOP) { 2177 /* 2178 * If sending a tty stop signal to a member of an orphaned 2179 * process group, discard the signal here if the action 2180 * is default; don't stop the process below if sleeping, 2181 * and don't clear any pending SIGCONT. 2182 */ 2183 if ((prop & SIGPROP_TTYSTOP) && 2184 (p->p_pgrp->pg_jobc == 0) && 2185 (action == SIG_DFL)) { 2186 if (ksi && (ksi->ksi_flags & KSI_INS)) 2187 ksiginfo_tryfree(ksi); 2188 return (ret); 2189 } 2190 sigqueue_delete_proc(p, SIGCONT); 2191 if (p->p_flag & P_CONTINUED) { 2192 p->p_flag &= ~P_CONTINUED; 2193 PROC_LOCK(p->p_pptr); 2194 sigqueue_take(p->p_ksi); 2195 PROC_UNLOCK(p->p_pptr); 2196 } 2197 } 2198 2199 ret = sigqueue_add(sigqueue, sig, ksi); 2200 if (ret != 0) 2201 return (ret); 2202 signotify(td); 2203 /* 2204 * Defer further processing for signals which are held, 2205 * except that stopped processes must be continued by SIGCONT. 2206 */ 2207 if (action == SIG_HOLD && 2208 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2209 return (ret); 2210 2211 /* SIGKILL: Remove procfs STOPEVENTs. */ 2212 if (sig == SIGKILL) { 2213 /* from procfs_ioctl.c: PIOCBIC */ 2214 p->p_stops = 0; 2215 /* from procfs_ioctl.c: PIOCCONT */ 2216 p->p_step = 0; 2217 wakeup(&p->p_step); 2218 } 2219 /* 2220 * Some signals have a process-wide effect and a per-thread 2221 * component. Most processing occurs when the process next 2222 * tries to cross the user boundary, however there are some 2223 * times when processing needs to be done immediately, such as 2224 * waking up threads so that they can cross the user boundary. 2225 * We try to do the per-process part here. 2226 */ 2227 if (P_SHOULDSTOP(p)) { 2228 KASSERT(!(p->p_flag & P_WEXIT), 2229 ("signal to stopped but exiting process")); 2230 if (sig == SIGKILL) { 2231 /* 2232 * If traced process is already stopped, 2233 * then no further action is necessary. 2234 */ 2235 if (p->p_flag & P_TRACED) 2236 goto out; 2237 /* 2238 * SIGKILL sets process running. 2239 * It will die elsewhere. 2240 * All threads must be restarted. 2241 */ 2242 p->p_flag &= ~P_STOPPED_SIG; 2243 goto runfast; 2244 } 2245 2246 if (prop & SIGPROP_CONT) { 2247 /* 2248 * If traced process is already stopped, 2249 * then no further action is necessary. 2250 */ 2251 if (p->p_flag & P_TRACED) 2252 goto out; 2253 /* 2254 * If SIGCONT is default (or ignored), we continue the 2255 * process but don't leave the signal in sigqueue as 2256 * it has no further action. If SIGCONT is held, we 2257 * continue the process and leave the signal in 2258 * sigqueue. If the process catches SIGCONT, let it 2259 * handle the signal itself. If it isn't waiting on 2260 * an event, it goes back to run state. 2261 * Otherwise, process goes back to sleep state. 2262 */ 2263 p->p_flag &= ~P_STOPPED_SIG; 2264 PROC_SLOCK(p); 2265 if (p->p_numthreads == p->p_suspcount) { 2266 PROC_SUNLOCK(p); 2267 p->p_flag |= P_CONTINUED; 2268 p->p_xsig = SIGCONT; 2269 PROC_LOCK(p->p_pptr); 2270 childproc_continued(p); 2271 PROC_UNLOCK(p->p_pptr); 2272 PROC_SLOCK(p); 2273 } 2274 if (action == SIG_DFL) { 2275 thread_unsuspend(p); 2276 PROC_SUNLOCK(p); 2277 sigqueue_delete(sigqueue, sig); 2278 goto out; 2279 } 2280 if (action == SIG_CATCH) { 2281 /* 2282 * The process wants to catch it so it needs 2283 * to run at least one thread, but which one? 2284 */ 2285 PROC_SUNLOCK(p); 2286 goto runfast; 2287 } 2288 /* 2289 * The signal is not ignored or caught. 2290 */ 2291 thread_unsuspend(p); 2292 PROC_SUNLOCK(p); 2293 goto out; 2294 } 2295 2296 if (prop & SIGPROP_STOP) { 2297 /* 2298 * If traced process is already stopped, 2299 * then no further action is necessary. 2300 */ 2301 if (p->p_flag & P_TRACED) 2302 goto out; 2303 /* 2304 * Already stopped, don't need to stop again 2305 * (If we did the shell could get confused). 2306 * Just make sure the signal STOP bit set. 2307 */ 2308 p->p_flag |= P_STOPPED_SIG; 2309 sigqueue_delete(sigqueue, sig); 2310 goto out; 2311 } 2312 2313 /* 2314 * All other kinds of signals: 2315 * If a thread is sleeping interruptibly, simulate a 2316 * wakeup so that when it is continued it will be made 2317 * runnable and can look at the signal. However, don't make 2318 * the PROCESS runnable, leave it stopped. 2319 * It may run a bit until it hits a thread_suspend_check(). 2320 */ 2321 wakeup_swapper = 0; 2322 PROC_SLOCK(p); 2323 thread_lock(td); 2324 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2325 wakeup_swapper = sleepq_abort(td, intrval); 2326 thread_unlock(td); 2327 PROC_SUNLOCK(p); 2328 if (wakeup_swapper) 2329 kick_proc0(); 2330 goto out; 2331 /* 2332 * Mutexes are short lived. Threads waiting on them will 2333 * hit thread_suspend_check() soon. 2334 */ 2335 } else if (p->p_state == PRS_NORMAL) { 2336 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2337 tdsigwakeup(td, sig, action, intrval); 2338 goto out; 2339 } 2340 2341 MPASS(action == SIG_DFL); 2342 2343 if (prop & SIGPROP_STOP) { 2344 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2345 goto out; 2346 p->p_flag |= P_STOPPED_SIG; 2347 p->p_xsig = sig; 2348 PROC_SLOCK(p); 2349 wakeup_swapper = sig_suspend_threads(td, p, 1); 2350 if (p->p_numthreads == p->p_suspcount) { 2351 /* 2352 * only thread sending signal to another 2353 * process can reach here, if thread is sending 2354 * signal to its process, because thread does 2355 * not suspend itself here, p_numthreads 2356 * should never be equal to p_suspcount. 2357 */ 2358 thread_stopped(p); 2359 PROC_SUNLOCK(p); 2360 sigqueue_delete_proc(p, p->p_xsig); 2361 } else 2362 PROC_SUNLOCK(p); 2363 if (wakeup_swapper) 2364 kick_proc0(); 2365 goto out; 2366 } 2367 } else { 2368 /* Not in "NORMAL" state. discard the signal. */ 2369 sigqueue_delete(sigqueue, sig); 2370 goto out; 2371 } 2372 2373 /* 2374 * The process is not stopped so we need to apply the signal to all the 2375 * running threads. 2376 */ 2377 runfast: 2378 tdsigwakeup(td, sig, action, intrval); 2379 PROC_SLOCK(p); 2380 thread_unsuspend(p); 2381 PROC_SUNLOCK(p); 2382 out: 2383 /* If we jump here, proc slock should not be owned. */ 2384 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2385 return (ret); 2386 } 2387 2388 /* 2389 * The force of a signal has been directed against a single 2390 * thread. We need to see what we can do about knocking it 2391 * out of any sleep it may be in etc. 2392 */ 2393 static void 2394 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2395 { 2396 struct proc *p = td->td_proc; 2397 int prop; 2398 int wakeup_swapper; 2399 2400 wakeup_swapper = 0; 2401 PROC_LOCK_ASSERT(p, MA_OWNED); 2402 prop = sigprop(sig); 2403 2404 PROC_SLOCK(p); 2405 thread_lock(td); 2406 /* 2407 * Bring the priority of a thread up if we want it to get 2408 * killed in this lifetime. Be careful to avoid bumping the 2409 * priority of the idle thread, since we still allow to signal 2410 * kernel processes. 2411 */ 2412 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2413 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2414 sched_prio(td, PUSER); 2415 if (TD_ON_SLEEPQ(td)) { 2416 /* 2417 * If thread is sleeping uninterruptibly 2418 * we can't interrupt the sleep... the signal will 2419 * be noticed when the process returns through 2420 * trap() or syscall(). 2421 */ 2422 if ((td->td_flags & TDF_SINTR) == 0) 2423 goto out; 2424 /* 2425 * If SIGCONT is default (or ignored) and process is 2426 * asleep, we are finished; the process should not 2427 * be awakened. 2428 */ 2429 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2430 thread_unlock(td); 2431 PROC_SUNLOCK(p); 2432 sigqueue_delete(&p->p_sigqueue, sig); 2433 /* 2434 * It may be on either list in this state. 2435 * Remove from both for now. 2436 */ 2437 sigqueue_delete(&td->td_sigqueue, sig); 2438 return; 2439 } 2440 2441 /* 2442 * Don't awaken a sleeping thread for SIGSTOP if the 2443 * STOP signal is deferred. 2444 */ 2445 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2446 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2447 goto out; 2448 2449 /* 2450 * Give low priority threads a better chance to run. 2451 */ 2452 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2453 sched_prio(td, PUSER); 2454 2455 wakeup_swapper = sleepq_abort(td, intrval); 2456 } else { 2457 /* 2458 * Other states do nothing with the signal immediately, 2459 * other than kicking ourselves if we are running. 2460 * It will either never be noticed, or noticed very soon. 2461 */ 2462 #ifdef SMP 2463 if (TD_IS_RUNNING(td) && td != curthread) 2464 forward_signal(td); 2465 #endif 2466 } 2467 out: 2468 PROC_SUNLOCK(p); 2469 thread_unlock(td); 2470 if (wakeup_swapper) 2471 kick_proc0(); 2472 } 2473 2474 static int 2475 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2476 { 2477 struct thread *td2; 2478 int wakeup_swapper; 2479 2480 PROC_LOCK_ASSERT(p, MA_OWNED); 2481 PROC_SLOCK_ASSERT(p, MA_OWNED); 2482 MPASS(sending || td == curthread); 2483 2484 wakeup_swapper = 0; 2485 FOREACH_THREAD_IN_PROC(p, td2) { 2486 thread_lock(td2); 2487 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2488 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2489 (td2->td_flags & TDF_SINTR)) { 2490 if (td2->td_flags & TDF_SBDRY) { 2491 /* 2492 * Once a thread is asleep with 2493 * TDF_SBDRY and without TDF_SERESTART 2494 * or TDF_SEINTR set, it should never 2495 * become suspended due to this check. 2496 */ 2497 KASSERT(!TD_IS_SUSPENDED(td2), 2498 ("thread with deferred stops suspended")); 2499 if (TD_SBDRY_INTR(td2)) 2500 wakeup_swapper |= sleepq_abort(td2, 2501 TD_SBDRY_ERRNO(td2)); 2502 } else if (!TD_IS_SUSPENDED(td2)) { 2503 thread_suspend_one(td2); 2504 } 2505 } else if (!TD_IS_SUSPENDED(td2)) { 2506 if (sending || td != td2) 2507 td2->td_flags |= TDF_ASTPENDING; 2508 #ifdef SMP 2509 if (TD_IS_RUNNING(td2) && td2 != td) 2510 forward_signal(td2); 2511 #endif 2512 } 2513 thread_unlock(td2); 2514 } 2515 return (wakeup_swapper); 2516 } 2517 2518 /* 2519 * Stop the process for an event deemed interesting to the debugger. If si is 2520 * non-NULL, this is a signal exchange; the new signal requested by the 2521 * debugger will be returned for handling. If si is NULL, this is some other 2522 * type of interesting event. The debugger may request a signal be delivered in 2523 * that case as well, however it will be deferred until it can be handled. 2524 */ 2525 int 2526 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2527 { 2528 struct proc *p = td->td_proc; 2529 struct thread *td2; 2530 ksiginfo_t ksi; 2531 int prop; 2532 2533 PROC_LOCK_ASSERT(p, MA_OWNED); 2534 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2535 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2536 &p->p_mtx.lock_object, "Stopping for traced signal"); 2537 2538 td->td_xsig = sig; 2539 2540 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2541 td->td_dbgflags |= TDB_XSIG; 2542 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2543 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2544 PROC_SLOCK(p); 2545 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2546 if (P_KILLED(p)) { 2547 /* 2548 * Ensure that, if we've been PT_KILLed, the 2549 * exit status reflects that. Another thread 2550 * may also be in ptracestop(), having just 2551 * received the SIGKILL, but this thread was 2552 * unsuspended first. 2553 */ 2554 td->td_dbgflags &= ~TDB_XSIG; 2555 td->td_xsig = SIGKILL; 2556 p->p_ptevents = 0; 2557 break; 2558 } 2559 if (p->p_flag & P_SINGLE_EXIT && 2560 !(td->td_dbgflags & TDB_EXIT)) { 2561 /* 2562 * Ignore ptrace stops except for thread exit 2563 * events when the process exits. 2564 */ 2565 td->td_dbgflags &= ~TDB_XSIG; 2566 PROC_SUNLOCK(p); 2567 return (0); 2568 } 2569 2570 /* 2571 * Make wait(2) work. Ensure that right after the 2572 * attach, the thread which was decided to become the 2573 * leader of attach gets reported to the waiter. 2574 * Otherwise, just avoid overwriting another thread's 2575 * assignment to p_xthread. If another thread has 2576 * already set p_xthread, the current thread will get 2577 * a chance to report itself upon the next iteration. 2578 */ 2579 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2580 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2581 p->p_xthread == NULL)) { 2582 p->p_xsig = sig; 2583 p->p_xthread = td; 2584 td->td_dbgflags &= ~TDB_FSTP; 2585 p->p_flag2 &= ~P2_PTRACE_FSTP; 2586 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2587 sig_suspend_threads(td, p, 0); 2588 } 2589 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2590 td->td_dbgflags &= ~TDB_STOPATFORK; 2591 cv_broadcast(&p->p_dbgwait); 2592 } 2593 stopme: 2594 thread_suspend_switch(td, p); 2595 if (p->p_xthread == td) 2596 p->p_xthread = NULL; 2597 if (!(p->p_flag & P_TRACED)) 2598 break; 2599 if (td->td_dbgflags & TDB_SUSPEND) { 2600 if (p->p_flag & P_SINGLE_EXIT) 2601 break; 2602 goto stopme; 2603 } 2604 } 2605 PROC_SUNLOCK(p); 2606 } 2607 2608 if (si != NULL && sig == td->td_xsig) { 2609 /* Parent wants us to take the original signal unchanged. */ 2610 si->ksi_flags |= KSI_HEAD; 2611 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2612 si->ksi_signo = 0; 2613 } else if (td->td_xsig != 0) { 2614 /* 2615 * If parent wants us to take a new signal, then it will leave 2616 * it in td->td_xsig; otherwise we just look for signals again. 2617 */ 2618 ksiginfo_init(&ksi); 2619 ksi.ksi_signo = td->td_xsig; 2620 ksi.ksi_flags |= KSI_PTRACE; 2621 prop = sigprop(td->td_xsig); 2622 td2 = sigtd(p, td->td_xsig, prop); 2623 tdsendsignal(p, td2, td->td_xsig, &ksi); 2624 if (td != td2) 2625 return (0); 2626 } 2627 2628 return (td->td_xsig); 2629 } 2630 2631 static void 2632 reschedule_signals(struct proc *p, sigset_t block, int flags) 2633 { 2634 struct sigacts *ps; 2635 struct thread *td; 2636 int sig; 2637 2638 PROC_LOCK_ASSERT(p, MA_OWNED); 2639 ps = p->p_sigacts; 2640 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2641 MA_OWNED : MA_NOTOWNED); 2642 if (SIGISEMPTY(p->p_siglist)) 2643 return; 2644 SIGSETAND(block, p->p_siglist); 2645 while ((sig = sig_ffs(&block)) != 0) { 2646 SIGDELSET(block, sig); 2647 td = sigtd(p, sig, 0); 2648 signotify(td); 2649 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2650 mtx_lock(&ps->ps_mtx); 2651 if (p->p_flag & P_TRACED || 2652 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2653 !SIGISMEMBER(td->td_sigmask, sig))) 2654 tdsigwakeup(td, sig, SIG_CATCH, 2655 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2656 ERESTART)); 2657 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2658 mtx_unlock(&ps->ps_mtx); 2659 } 2660 } 2661 2662 void 2663 tdsigcleanup(struct thread *td) 2664 { 2665 struct proc *p; 2666 sigset_t unblocked; 2667 2668 p = td->td_proc; 2669 PROC_LOCK_ASSERT(p, MA_OWNED); 2670 2671 sigqueue_flush(&td->td_sigqueue); 2672 if (p->p_numthreads == 1) 2673 return; 2674 2675 /* 2676 * Since we cannot handle signals, notify signal post code 2677 * about this by filling the sigmask. 2678 * 2679 * Also, if needed, wake up thread(s) that do not block the 2680 * same signals as the exiting thread, since the thread might 2681 * have been selected for delivery and woken up. 2682 */ 2683 SIGFILLSET(unblocked); 2684 SIGSETNAND(unblocked, td->td_sigmask); 2685 SIGFILLSET(td->td_sigmask); 2686 reschedule_signals(p, unblocked, 0); 2687 2688 } 2689 2690 static int 2691 sigdeferstop_curr_flags(int cflags) 2692 { 2693 2694 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2695 (cflags & TDF_SBDRY) != 0); 2696 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2697 } 2698 2699 /* 2700 * Defer the delivery of SIGSTOP for the current thread, according to 2701 * the requested mode. Returns previous flags, which must be restored 2702 * by sigallowstop(). 2703 * 2704 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2705 * cleared by the current thread, which allow the lock-less read-only 2706 * accesses below. 2707 */ 2708 int 2709 sigdeferstop_impl(int mode) 2710 { 2711 struct thread *td; 2712 int cflags, nflags; 2713 2714 td = curthread; 2715 cflags = sigdeferstop_curr_flags(td->td_flags); 2716 switch (mode) { 2717 case SIGDEFERSTOP_NOP: 2718 nflags = cflags; 2719 break; 2720 case SIGDEFERSTOP_OFF: 2721 nflags = 0; 2722 break; 2723 case SIGDEFERSTOP_SILENT: 2724 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2725 break; 2726 case SIGDEFERSTOP_EINTR: 2727 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2728 break; 2729 case SIGDEFERSTOP_ERESTART: 2730 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2731 break; 2732 default: 2733 panic("sigdeferstop: invalid mode %x", mode); 2734 break; 2735 } 2736 if (cflags == nflags) 2737 return (SIGDEFERSTOP_VAL_NCHG); 2738 thread_lock(td); 2739 td->td_flags = (td->td_flags & ~cflags) | nflags; 2740 thread_unlock(td); 2741 return (cflags); 2742 } 2743 2744 /* 2745 * Restores the STOP handling mode, typically permitting the delivery 2746 * of SIGSTOP for the current thread. This does not immediately 2747 * suspend if a stop was posted. Instead, the thread will suspend 2748 * either via ast() or a subsequent interruptible sleep. 2749 */ 2750 void 2751 sigallowstop_impl(int prev) 2752 { 2753 struct thread *td; 2754 int cflags; 2755 2756 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2757 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2758 ("sigallowstop: incorrect previous mode %x", prev)); 2759 td = curthread; 2760 cflags = sigdeferstop_curr_flags(td->td_flags); 2761 if (cflags != prev) { 2762 thread_lock(td); 2763 td->td_flags = (td->td_flags & ~cflags) | prev; 2764 thread_unlock(td); 2765 } 2766 } 2767 2768 /* 2769 * If the current process has received a signal (should be caught or cause 2770 * termination, should interrupt current syscall), return the signal number. 2771 * Stop signals with default action are processed immediately, then cleared; 2772 * they aren't returned. This is checked after each entry to the system for 2773 * a syscall or trap (though this can usually be done without calling issignal 2774 * by checking the pending signal masks in cursig.) The normal call 2775 * sequence is 2776 * 2777 * while (sig = cursig(curthread)) 2778 * postsig(sig); 2779 */ 2780 static int 2781 issignal(struct thread *td) 2782 { 2783 struct proc *p; 2784 struct sigacts *ps; 2785 struct sigqueue *queue; 2786 sigset_t sigpending; 2787 ksiginfo_t ksi; 2788 int prop, sig, traced; 2789 2790 p = td->td_proc; 2791 ps = p->p_sigacts; 2792 mtx_assert(&ps->ps_mtx, MA_OWNED); 2793 PROC_LOCK_ASSERT(p, MA_OWNED); 2794 for (;;) { 2795 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2796 2797 sigpending = td->td_sigqueue.sq_signals; 2798 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2799 SIGSETNAND(sigpending, td->td_sigmask); 2800 2801 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2802 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2803 SIG_STOPSIGMASK(sigpending); 2804 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2805 return (0); 2806 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2807 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2808 SIGISMEMBER(sigpending, SIGSTOP)) { 2809 /* 2810 * If debugger just attached, always consume 2811 * SIGSTOP from ptrace(PT_ATTACH) first, to 2812 * execute the debugger attach ritual in 2813 * order. 2814 */ 2815 sig = SIGSTOP; 2816 td->td_dbgflags |= TDB_FSTP; 2817 } else { 2818 sig = sig_ffs(&sigpending); 2819 } 2820 2821 if (p->p_stops & S_SIG) { 2822 mtx_unlock(&ps->ps_mtx); 2823 stopevent(p, S_SIG, sig); 2824 mtx_lock(&ps->ps_mtx); 2825 } 2826 2827 /* 2828 * We should see pending but ignored signals 2829 * only if P_TRACED was on when they were posted. 2830 */ 2831 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2832 sigqueue_delete(&td->td_sigqueue, sig); 2833 sigqueue_delete(&p->p_sigqueue, sig); 2834 continue; 2835 } 2836 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2837 /* 2838 * If traced, always stop. 2839 * Remove old signal from queue before the stop. 2840 * XXX shrug off debugger, it causes siginfo to 2841 * be thrown away. 2842 */ 2843 queue = &td->td_sigqueue; 2844 ksiginfo_init(&ksi); 2845 if (sigqueue_get(queue, sig, &ksi) == 0) { 2846 queue = &p->p_sigqueue; 2847 sigqueue_get(queue, sig, &ksi); 2848 } 2849 td->td_si = ksi.ksi_info; 2850 2851 mtx_unlock(&ps->ps_mtx); 2852 sig = ptracestop(td, sig, &ksi); 2853 mtx_lock(&ps->ps_mtx); 2854 2855 /* 2856 * Keep looking if the debugger discarded or 2857 * replaced the signal. 2858 */ 2859 if (sig == 0) 2860 continue; 2861 2862 /* 2863 * If the signal became masked, re-queue it. 2864 */ 2865 if (SIGISMEMBER(td->td_sigmask, sig)) { 2866 ksi.ksi_flags |= KSI_HEAD; 2867 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2868 continue; 2869 } 2870 2871 /* 2872 * If the traced bit got turned off, requeue 2873 * the signal and go back up to the top to 2874 * rescan signals. This ensures that p_sig* 2875 * and p_sigact are consistent. 2876 */ 2877 if ((p->p_flag & P_TRACED) == 0) { 2878 ksi.ksi_flags |= KSI_HEAD; 2879 sigqueue_add(queue, sig, &ksi); 2880 continue; 2881 } 2882 } 2883 2884 prop = sigprop(sig); 2885 2886 /* 2887 * Decide whether the signal should be returned. 2888 * Return the signal's number, or fall through 2889 * to clear it from the pending mask. 2890 */ 2891 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2892 2893 case (intptr_t)SIG_DFL: 2894 /* 2895 * Don't take default actions on system processes. 2896 */ 2897 if (p->p_pid <= 1) { 2898 #ifdef DIAGNOSTIC 2899 /* 2900 * Are you sure you want to ignore SIGSEGV 2901 * in init? XXX 2902 */ 2903 printf("Process (pid %lu) got signal %d\n", 2904 (u_long)p->p_pid, sig); 2905 #endif 2906 break; /* == ignore */ 2907 } 2908 /* 2909 * If there is a pending stop signal to process with 2910 * default action, stop here, then clear the signal. 2911 * Traced or exiting processes should ignore stops. 2912 * Additionally, a member of an orphaned process group 2913 * should ignore tty stops. 2914 */ 2915 if (prop & SIGPROP_STOP) { 2916 if (p->p_flag & 2917 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2918 (p->p_pgrp->pg_jobc == 0 && 2919 prop & SIGPROP_TTYSTOP)) 2920 break; /* == ignore */ 2921 if (TD_SBDRY_INTR(td)) { 2922 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2923 ("lost TDF_SBDRY")); 2924 return (-1); 2925 } 2926 mtx_unlock(&ps->ps_mtx); 2927 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2928 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2929 sigqueue_delete(&td->td_sigqueue, sig); 2930 sigqueue_delete(&p->p_sigqueue, sig); 2931 p->p_flag |= P_STOPPED_SIG; 2932 p->p_xsig = sig; 2933 PROC_SLOCK(p); 2934 sig_suspend_threads(td, p, 0); 2935 thread_suspend_switch(td, p); 2936 PROC_SUNLOCK(p); 2937 mtx_lock(&ps->ps_mtx); 2938 goto next; 2939 } else if (prop & SIGPROP_IGNORE) { 2940 /* 2941 * Except for SIGCONT, shouldn't get here. 2942 * Default action is to ignore; drop it. 2943 */ 2944 break; /* == ignore */ 2945 } else 2946 return (sig); 2947 /*NOTREACHED*/ 2948 2949 case (intptr_t)SIG_IGN: 2950 /* 2951 * Masking above should prevent us ever trying 2952 * to take action on an ignored signal other 2953 * than SIGCONT, unless process is traced. 2954 */ 2955 if ((prop & SIGPROP_CONT) == 0 && 2956 (p->p_flag & P_TRACED) == 0) 2957 printf("issignal\n"); 2958 break; /* == ignore */ 2959 2960 default: 2961 /* 2962 * This signal has an action, let 2963 * postsig() process it. 2964 */ 2965 return (sig); 2966 } 2967 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2968 sigqueue_delete(&p->p_sigqueue, sig); 2969 next:; 2970 } 2971 /* NOTREACHED */ 2972 } 2973 2974 void 2975 thread_stopped(struct proc *p) 2976 { 2977 int n; 2978 2979 PROC_LOCK_ASSERT(p, MA_OWNED); 2980 PROC_SLOCK_ASSERT(p, MA_OWNED); 2981 n = p->p_suspcount; 2982 if (p == curproc) 2983 n++; 2984 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2985 PROC_SUNLOCK(p); 2986 p->p_flag &= ~P_WAITED; 2987 PROC_LOCK(p->p_pptr); 2988 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2989 CLD_TRAPPED : CLD_STOPPED); 2990 PROC_UNLOCK(p->p_pptr); 2991 PROC_SLOCK(p); 2992 } 2993 } 2994 2995 /* 2996 * Take the action for the specified signal 2997 * from the current set of pending signals. 2998 */ 2999 int 3000 postsig(int sig) 3001 { 3002 struct thread *td; 3003 struct proc *p; 3004 struct sigacts *ps; 3005 sig_t action; 3006 ksiginfo_t ksi; 3007 sigset_t returnmask; 3008 3009 KASSERT(sig != 0, ("postsig")); 3010 3011 td = curthread; 3012 p = td->td_proc; 3013 PROC_LOCK_ASSERT(p, MA_OWNED); 3014 ps = p->p_sigacts; 3015 mtx_assert(&ps->ps_mtx, MA_OWNED); 3016 ksiginfo_init(&ksi); 3017 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3018 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3019 return (0); 3020 ksi.ksi_signo = sig; 3021 if (ksi.ksi_code == SI_TIMER) 3022 itimer_accept(p, ksi.ksi_timerid, &ksi); 3023 action = ps->ps_sigact[_SIG_IDX(sig)]; 3024 #ifdef KTRACE 3025 if (KTRPOINT(td, KTR_PSIG)) 3026 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3027 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3028 #endif 3029 if ((p->p_stops & S_SIG) != 0) { 3030 mtx_unlock(&ps->ps_mtx); 3031 stopevent(p, S_SIG, sig); 3032 mtx_lock(&ps->ps_mtx); 3033 } 3034 3035 if (action == SIG_DFL) { 3036 /* 3037 * Default action, where the default is to kill 3038 * the process. (Other cases were ignored above.) 3039 */ 3040 mtx_unlock(&ps->ps_mtx); 3041 proc_td_siginfo_capture(td, &ksi.ksi_info); 3042 sigexit(td, sig); 3043 /* NOTREACHED */ 3044 } else { 3045 /* 3046 * If we get here, the signal must be caught. 3047 */ 3048 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3049 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3050 ("postsig action: blocked sig %d", sig)); 3051 3052 /* 3053 * Set the new mask value and also defer further 3054 * occurrences of this signal. 3055 * 3056 * Special case: user has done a sigsuspend. Here the 3057 * current mask is not of interest, but rather the 3058 * mask from before the sigsuspend is what we want 3059 * restored after the signal processing is completed. 3060 */ 3061 if (td->td_pflags & TDP_OLDMASK) { 3062 returnmask = td->td_oldsigmask; 3063 td->td_pflags &= ~TDP_OLDMASK; 3064 } else 3065 returnmask = td->td_sigmask; 3066 3067 if (p->p_sig == sig) { 3068 p->p_code = 0; 3069 p->p_sig = 0; 3070 } 3071 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3072 postsig_done(sig, td, ps); 3073 } 3074 return (1); 3075 } 3076 3077 /* 3078 * Kill the current process for stated reason. 3079 */ 3080 void 3081 killproc(struct proc *p, char *why) 3082 { 3083 3084 PROC_LOCK_ASSERT(p, MA_OWNED); 3085 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3086 p->p_comm); 3087 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3088 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3089 p->p_flag |= P_WKILLED; 3090 kern_psignal(p, SIGKILL); 3091 } 3092 3093 /* 3094 * Force the current process to exit with the specified signal, dumping core 3095 * if appropriate. We bypass the normal tests for masked and caught signals, 3096 * allowing unrecoverable failures to terminate the process without changing 3097 * signal state. Mark the accounting record with the signal termination. 3098 * If dumping core, save the signal number for the debugger. Calls exit and 3099 * does not return. 3100 */ 3101 void 3102 sigexit(struct thread *td, int sig) 3103 { 3104 struct proc *p = td->td_proc; 3105 3106 PROC_LOCK_ASSERT(p, MA_OWNED); 3107 p->p_acflag |= AXSIG; 3108 /* 3109 * We must be single-threading to generate a core dump. This 3110 * ensures that the registers in the core file are up-to-date. 3111 * Also, the ELF dump handler assumes that the thread list doesn't 3112 * change out from under it. 3113 * 3114 * XXX If another thread attempts to single-thread before us 3115 * (e.g. via fork()), we won't get a dump at all. 3116 */ 3117 if ((sigprop(sig) & SIGPROP_CORE) && 3118 thread_single(p, SINGLE_NO_EXIT) == 0) { 3119 p->p_sig = sig; 3120 /* 3121 * Log signals which would cause core dumps 3122 * (Log as LOG_INFO to appease those who don't want 3123 * these messages.) 3124 * XXX : Todo, as well as euid, write out ruid too 3125 * Note that coredump() drops proc lock. 3126 */ 3127 if (coredump(td) == 0) 3128 sig |= WCOREFLAG; 3129 if (kern_logsigexit) 3130 log(LOG_INFO, 3131 "pid %d (%s), uid %d: exited on signal %d%s\n", 3132 p->p_pid, p->p_comm, 3133 td->td_ucred ? td->td_ucred->cr_uid : -1, 3134 sig &~ WCOREFLAG, 3135 sig & WCOREFLAG ? " (core dumped)" : ""); 3136 } else 3137 PROC_UNLOCK(p); 3138 exit1(td, 0, sig); 3139 /* NOTREACHED */ 3140 } 3141 3142 /* 3143 * Send queued SIGCHLD to parent when child process's state 3144 * is changed. 3145 */ 3146 static void 3147 sigparent(struct proc *p, int reason, int status) 3148 { 3149 PROC_LOCK_ASSERT(p, MA_OWNED); 3150 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3151 3152 if (p->p_ksi != NULL) { 3153 p->p_ksi->ksi_signo = SIGCHLD; 3154 p->p_ksi->ksi_code = reason; 3155 p->p_ksi->ksi_status = status; 3156 p->p_ksi->ksi_pid = p->p_pid; 3157 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3158 if (KSI_ONQ(p->p_ksi)) 3159 return; 3160 } 3161 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3162 } 3163 3164 static void 3165 childproc_jobstate(struct proc *p, int reason, int sig) 3166 { 3167 struct sigacts *ps; 3168 3169 PROC_LOCK_ASSERT(p, MA_OWNED); 3170 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3171 3172 /* 3173 * Wake up parent sleeping in kern_wait(), also send 3174 * SIGCHLD to parent, but SIGCHLD does not guarantee 3175 * that parent will awake, because parent may masked 3176 * the signal. 3177 */ 3178 p->p_pptr->p_flag |= P_STATCHILD; 3179 wakeup(p->p_pptr); 3180 3181 ps = p->p_pptr->p_sigacts; 3182 mtx_lock(&ps->ps_mtx); 3183 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3184 mtx_unlock(&ps->ps_mtx); 3185 sigparent(p, reason, sig); 3186 } else 3187 mtx_unlock(&ps->ps_mtx); 3188 } 3189 3190 void 3191 childproc_stopped(struct proc *p, int reason) 3192 { 3193 3194 childproc_jobstate(p, reason, p->p_xsig); 3195 } 3196 3197 void 3198 childproc_continued(struct proc *p) 3199 { 3200 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3201 } 3202 3203 void 3204 childproc_exited(struct proc *p) 3205 { 3206 int reason, status; 3207 3208 if (WCOREDUMP(p->p_xsig)) { 3209 reason = CLD_DUMPED; 3210 status = WTERMSIG(p->p_xsig); 3211 } else if (WIFSIGNALED(p->p_xsig)) { 3212 reason = CLD_KILLED; 3213 status = WTERMSIG(p->p_xsig); 3214 } else { 3215 reason = CLD_EXITED; 3216 status = p->p_xexit; 3217 } 3218 /* 3219 * XXX avoid calling wakeup(p->p_pptr), the work is 3220 * done in exit1(). 3221 */ 3222 sigparent(p, reason, status); 3223 } 3224 3225 /* 3226 * We only have 1 character for the core count in the format 3227 * string, so the range will be 0-9 3228 */ 3229 #define MAX_NUM_CORE_FILES 10 3230 #ifndef NUM_CORE_FILES 3231 #define NUM_CORE_FILES 5 3232 #endif 3233 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3234 static int num_cores = NUM_CORE_FILES; 3235 3236 static int 3237 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3238 { 3239 int error; 3240 int new_val; 3241 3242 new_val = num_cores; 3243 error = sysctl_handle_int(oidp, &new_val, 0, req); 3244 if (error != 0 || req->newptr == NULL) 3245 return (error); 3246 if (new_val > MAX_NUM_CORE_FILES) 3247 new_val = MAX_NUM_CORE_FILES; 3248 if (new_val < 0) 3249 new_val = 0; 3250 num_cores = new_val; 3251 return (0); 3252 } 3253 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3254 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3255 3256 #define GZ_SUFFIX ".gz" 3257 3258 int compress_user_cores = 0; 3259 3260 static int 3261 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3262 { 3263 int error, val; 3264 3265 val = compress_user_cores; 3266 error = sysctl_handle_int(oidp, &val, 0, req); 3267 if (error != 0 || req->newptr == NULL) 3268 return (error); 3269 if (val != 0 && !compressor_avail(val)) 3270 return (EINVAL); 3271 compress_user_cores = val; 3272 return (error); 3273 } 3274 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3275 0, sizeof(int), sysctl_compress_user_cores, "I", 3276 "Enable compression of user corefiles (" __XSTRING(COMPRESS_GZIP) " = gzip)"); 3277 3278 int compress_user_cores_level = 6; 3279 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3280 &compress_user_cores_level, 0, 3281 "Corefile compression level"); 3282 3283 /* 3284 * Protect the access to corefilename[] by allproc_lock. 3285 */ 3286 #define corefilename_lock allproc_lock 3287 3288 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3289 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3290 3291 static int 3292 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3293 { 3294 int error; 3295 3296 sx_xlock(&corefilename_lock); 3297 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3298 req); 3299 sx_xunlock(&corefilename_lock); 3300 3301 return (error); 3302 } 3303 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3304 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3305 "Process corefile name format string"); 3306 3307 /* 3308 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3309 * Expand the name described in corefilename, using name, uid, and pid 3310 * and open/create core file. 3311 * corefilename is a printf-like string, with three format specifiers: 3312 * %N name of process ("name") 3313 * %P process id (pid) 3314 * %U user id (uid) 3315 * For example, "%N.core" is the default; they can be disabled completely 3316 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3317 * This is controlled by the sysctl variable kern.corefile (see above). 3318 */ 3319 static int 3320 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3321 int compress, struct vnode **vpp, char **namep) 3322 { 3323 struct nameidata nd; 3324 struct sbuf sb; 3325 const char *format; 3326 char *hostname, *name; 3327 int indexpos, i, error, cmode, flags, oflags; 3328 3329 hostname = NULL; 3330 format = corefilename; 3331 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3332 indexpos = -1; 3333 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3334 sx_slock(&corefilename_lock); 3335 for (i = 0; format[i] != '\0'; i++) { 3336 switch (format[i]) { 3337 case '%': /* Format character */ 3338 i++; 3339 switch (format[i]) { 3340 case '%': 3341 sbuf_putc(&sb, '%'); 3342 break; 3343 case 'H': /* hostname */ 3344 if (hostname == NULL) { 3345 hostname = malloc(MAXHOSTNAMELEN, 3346 M_TEMP, M_WAITOK); 3347 } 3348 getcredhostname(td->td_ucred, hostname, 3349 MAXHOSTNAMELEN); 3350 sbuf_printf(&sb, "%s", hostname); 3351 break; 3352 case 'I': /* autoincrementing index */ 3353 sbuf_printf(&sb, "0"); 3354 indexpos = sbuf_len(&sb) - 1; 3355 break; 3356 case 'N': /* process name */ 3357 sbuf_printf(&sb, "%s", comm); 3358 break; 3359 case 'P': /* process id */ 3360 sbuf_printf(&sb, "%u", pid); 3361 break; 3362 case 'U': /* user id */ 3363 sbuf_printf(&sb, "%u", uid); 3364 break; 3365 default: 3366 log(LOG_ERR, 3367 "Unknown format character %c in " 3368 "corename `%s'\n", format[i], format); 3369 break; 3370 } 3371 break; 3372 default: 3373 sbuf_putc(&sb, format[i]); 3374 break; 3375 } 3376 } 3377 sx_sunlock(&corefilename_lock); 3378 free(hostname, M_TEMP); 3379 if (compress == COMPRESS_GZIP) 3380 sbuf_printf(&sb, GZ_SUFFIX); 3381 if (sbuf_error(&sb) != 0) { 3382 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3383 "long\n", (long)pid, comm, (u_long)uid); 3384 sbuf_delete(&sb); 3385 free(name, M_TEMP); 3386 return (ENOMEM); 3387 } 3388 sbuf_finish(&sb); 3389 sbuf_delete(&sb); 3390 3391 cmode = S_IRUSR | S_IWUSR; 3392 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3393 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3394 3395 /* 3396 * If the core format has a %I in it, then we need to check 3397 * for existing corefiles before returning a name. 3398 * To do this we iterate over 0..num_cores to find a 3399 * non-existing core file name to use. 3400 */ 3401 if (indexpos != -1) { 3402 for (i = 0; i < num_cores; i++) { 3403 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3404 name[indexpos] = '0' + i; 3405 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3406 error = vn_open_cred(&nd, &flags, cmode, oflags, 3407 td->td_ucred, NULL); 3408 if (error) { 3409 if (error == EEXIST) 3410 continue; 3411 log(LOG_ERR, 3412 "pid %d (%s), uid (%u): Path `%s' failed " 3413 "on initial open test, error = %d\n", 3414 pid, comm, uid, name, error); 3415 } 3416 goto out; 3417 } 3418 } 3419 3420 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3421 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3422 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3423 out: 3424 if (error) { 3425 #ifdef AUDIT 3426 audit_proc_coredump(td, name, error); 3427 #endif 3428 free(name, M_TEMP); 3429 return (error); 3430 } 3431 NDFREE(&nd, NDF_ONLY_PNBUF); 3432 *vpp = nd.ni_vp; 3433 *namep = name; 3434 return (0); 3435 } 3436 3437 static int 3438 coredump_sanitise_path(const char *path) 3439 { 3440 size_t i; 3441 3442 /* 3443 * Only send a subset of ASCII to devd(8) because it 3444 * might pass these strings to sh -c. 3445 */ 3446 for (i = 0; path[i]; i++) 3447 if (!(isalpha(path[i]) || isdigit(path[i])) && 3448 path[i] != '/' && path[i] != '.' && 3449 path[i] != '-') 3450 return (0); 3451 3452 return (1); 3453 } 3454 3455 /* 3456 * Dump a process' core. The main routine does some 3457 * policy checking, and creates the name of the coredump; 3458 * then it passes on a vnode and a size limit to the process-specific 3459 * coredump routine if there is one; if there _is not_ one, it returns 3460 * ENOSYS; otherwise it returns the error from the process-specific routine. 3461 */ 3462 3463 static int 3464 coredump(struct thread *td) 3465 { 3466 struct proc *p = td->td_proc; 3467 struct ucred *cred = td->td_ucred; 3468 struct vnode *vp; 3469 struct flock lf; 3470 struct vattr vattr; 3471 int error, error1, locked; 3472 char *name; /* name of corefile */ 3473 void *rl_cookie; 3474 off_t limit; 3475 char *data = NULL; 3476 char *fullpath, *freepath = NULL; 3477 size_t len; 3478 static const char comm_name[] = "comm="; 3479 static const char core_name[] = "core="; 3480 3481 PROC_LOCK_ASSERT(p, MA_OWNED); 3482 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3483 _STOPEVENT(p, S_CORE, 0); 3484 3485 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3486 (p->p_flag2 & P2_NOTRACE) != 0) { 3487 PROC_UNLOCK(p); 3488 return (EFAULT); 3489 } 3490 3491 /* 3492 * Note that the bulk of limit checking is done after 3493 * the corefile is created. The exception is if the limit 3494 * for corefiles is 0, in which case we don't bother 3495 * creating the corefile at all. This layout means that 3496 * a corefile is truncated instead of not being created, 3497 * if it is larger than the limit. 3498 */ 3499 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3500 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3501 PROC_UNLOCK(p); 3502 return (EFBIG); 3503 } 3504 PROC_UNLOCK(p); 3505 3506 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3507 compress_user_cores, &vp, &name); 3508 if (error != 0) 3509 return (error); 3510 3511 /* 3512 * Don't dump to non-regular files or files with links. 3513 * Do not dump into system files. 3514 */ 3515 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3516 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3517 VOP_UNLOCK(vp, 0); 3518 error = EFAULT; 3519 goto out; 3520 } 3521 3522 VOP_UNLOCK(vp, 0); 3523 3524 /* Postpone other writers, including core dumps of other processes. */ 3525 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3526 3527 lf.l_whence = SEEK_SET; 3528 lf.l_start = 0; 3529 lf.l_len = 0; 3530 lf.l_type = F_WRLCK; 3531 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3532 3533 VATTR_NULL(&vattr); 3534 vattr.va_size = 0; 3535 if (set_core_nodump_flag) 3536 vattr.va_flags = UF_NODUMP; 3537 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3538 VOP_SETATTR(vp, &vattr, cred); 3539 VOP_UNLOCK(vp, 0); 3540 PROC_LOCK(p); 3541 p->p_acflag |= ACORE; 3542 PROC_UNLOCK(p); 3543 3544 if (p->p_sysent->sv_coredump != NULL) { 3545 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3546 } else { 3547 error = ENOSYS; 3548 } 3549 3550 if (locked) { 3551 lf.l_type = F_UNLCK; 3552 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3553 } 3554 vn_rangelock_unlock(vp, rl_cookie); 3555 3556 /* 3557 * Notify the userland helper that a process triggered a core dump. 3558 * This allows the helper to run an automated debugging session. 3559 */ 3560 if (error != 0 || coredump_devctl == 0) 3561 goto out; 3562 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3563 sizeof(' ') + sizeof(core_name) - 1; 3564 data = malloc(len, M_TEMP, M_WAITOK); 3565 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3566 goto out; 3567 if (!coredump_sanitise_path(fullpath)) 3568 goto out; 3569 snprintf(data, len, "%s%s ", comm_name, fullpath); 3570 free(freepath, M_TEMP); 3571 freepath = NULL; 3572 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3573 goto out; 3574 if (!coredump_sanitise_path(fullpath)) 3575 goto out; 3576 strlcat(data, core_name, len); 3577 strlcat(data, fullpath, len); 3578 devctl_notify("kernel", "signal", "coredump", data); 3579 out: 3580 error1 = vn_close(vp, FWRITE, cred, td); 3581 if (error == 0) 3582 error = error1; 3583 #ifdef AUDIT 3584 audit_proc_coredump(td, name, error); 3585 #endif 3586 free(freepath, M_TEMP); 3587 free(data, M_TEMP); 3588 free(name, M_TEMP); 3589 return (error); 3590 } 3591 3592 /* 3593 * Nonexistent system call-- signal process (may want to handle it). Flag 3594 * error in case process won't see signal immediately (blocked or ignored). 3595 */ 3596 #ifndef _SYS_SYSPROTO_H_ 3597 struct nosys_args { 3598 int dummy; 3599 }; 3600 #endif 3601 /* ARGSUSED */ 3602 int 3603 nosys(struct thread *td, struct nosys_args *args) 3604 { 3605 struct proc *p; 3606 3607 p = td->td_proc; 3608 3609 PROC_LOCK(p); 3610 tdsignal(td, SIGSYS); 3611 PROC_UNLOCK(p); 3612 if (kern_lognosys == 1 || kern_lognosys == 3) { 3613 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3614 td->td_sa.code); 3615 } 3616 if (kern_lognosys == 2 || kern_lognosys == 3) { 3617 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3618 td->td_sa.code); 3619 } 3620 return (ENOSYS); 3621 } 3622 3623 /* 3624 * Send a SIGIO or SIGURG signal to a process or process group using stored 3625 * credentials rather than those of the current process. 3626 */ 3627 void 3628 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3629 { 3630 ksiginfo_t ksi; 3631 struct sigio *sigio; 3632 3633 ksiginfo_init(&ksi); 3634 ksi.ksi_signo = sig; 3635 ksi.ksi_code = SI_KERNEL; 3636 3637 SIGIO_LOCK(); 3638 sigio = *sigiop; 3639 if (sigio == NULL) { 3640 SIGIO_UNLOCK(); 3641 return; 3642 } 3643 if (sigio->sio_pgid > 0) { 3644 PROC_LOCK(sigio->sio_proc); 3645 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3646 kern_psignal(sigio->sio_proc, sig); 3647 PROC_UNLOCK(sigio->sio_proc); 3648 } else if (sigio->sio_pgid < 0) { 3649 struct proc *p; 3650 3651 PGRP_LOCK(sigio->sio_pgrp); 3652 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3653 PROC_LOCK(p); 3654 if (p->p_state == PRS_NORMAL && 3655 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3656 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3657 kern_psignal(p, sig); 3658 PROC_UNLOCK(p); 3659 } 3660 PGRP_UNLOCK(sigio->sio_pgrp); 3661 } 3662 SIGIO_UNLOCK(); 3663 } 3664 3665 static int 3666 filt_sigattach(struct knote *kn) 3667 { 3668 struct proc *p = curproc; 3669 3670 kn->kn_ptr.p_proc = p; 3671 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3672 3673 knlist_add(p->p_klist, kn, 0); 3674 3675 return (0); 3676 } 3677 3678 static void 3679 filt_sigdetach(struct knote *kn) 3680 { 3681 struct proc *p = kn->kn_ptr.p_proc; 3682 3683 knlist_remove(p->p_klist, kn, 0); 3684 } 3685 3686 /* 3687 * signal knotes are shared with proc knotes, so we apply a mask to 3688 * the hint in order to differentiate them from process hints. This 3689 * could be avoided by using a signal-specific knote list, but probably 3690 * isn't worth the trouble. 3691 */ 3692 static int 3693 filt_signal(struct knote *kn, long hint) 3694 { 3695 3696 if (hint & NOTE_SIGNAL) { 3697 hint &= ~NOTE_SIGNAL; 3698 3699 if (kn->kn_id == hint) 3700 kn->kn_data++; 3701 } 3702 return (kn->kn_data != 0); 3703 } 3704 3705 struct sigacts * 3706 sigacts_alloc(void) 3707 { 3708 struct sigacts *ps; 3709 3710 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3711 refcount_init(&ps->ps_refcnt, 1); 3712 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3713 return (ps); 3714 } 3715 3716 void 3717 sigacts_free(struct sigacts *ps) 3718 { 3719 3720 if (refcount_release(&ps->ps_refcnt) == 0) 3721 return; 3722 mtx_destroy(&ps->ps_mtx); 3723 free(ps, M_SUBPROC); 3724 } 3725 3726 struct sigacts * 3727 sigacts_hold(struct sigacts *ps) 3728 { 3729 3730 refcount_acquire(&ps->ps_refcnt); 3731 return (ps); 3732 } 3733 3734 void 3735 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3736 { 3737 3738 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3739 mtx_lock(&src->ps_mtx); 3740 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3741 mtx_unlock(&src->ps_mtx); 3742 } 3743 3744 int 3745 sigacts_shared(struct sigacts *ps) 3746 { 3747 3748 return (ps->ps_refcnt > 1); 3749 } 3750