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_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/lock.h> 61 #include <sys/malloc.h> 62 #include <sys/mutex.h> 63 #include <sys/refcount.h> 64 #include <sys/namei.h> 65 #include <sys/proc.h> 66 #include <sys/procdesc.h> 67 #include <sys/posix4.h> 68 #include <sys/pioctl.h> 69 #include <sys/racct.h> 70 #include <sys/resourcevar.h> 71 #include <sys/sdt.h> 72 #include <sys/sbuf.h> 73 #include <sys/sleepqueue.h> 74 #include <sys/smp.h> 75 #include <sys/stat.h> 76 #include <sys/sx.h> 77 #include <sys/syscallsubr.h> 78 #include <sys/sysctl.h> 79 #include <sys/sysent.h> 80 #include <sys/syslog.h> 81 #include <sys/sysproto.h> 82 #include <sys/timers.h> 83 #include <sys/unistd.h> 84 #include <sys/wait.h> 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/uma.h> 88 89 #include <sys/jail.h> 90 91 #include <machine/cpu.h> 92 93 #include <security/audit/audit.h> 94 95 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE3(proc, , , signal__send, 99 "struct thread *", "struct proc *", "int"); 100 SDT_PROBE_DEFINE2(proc, , , signal__clear, 101 "int", "ksiginfo_t *"); 102 SDT_PROBE_DEFINE3(proc, , , signal__discard, 103 "struct thread *", "struct proc *", "int"); 104 105 static int coredump(struct thread *); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td); 109 static int sigprop(int sig); 110 static void tdsigwakeup(struct thread *, int, sig_t, int); 111 static int sig_suspend_threads(struct thread *, struct proc *, int); 112 static int filt_sigattach(struct knote *kn); 113 static void filt_sigdetach(struct knote *kn); 114 static int filt_signal(struct knote *kn, long hint); 115 static struct thread *sigtd(struct proc *p, int sig, int prop); 116 static void sigqueue_start(void); 117 118 static uma_zone_t ksiginfo_zone = NULL; 119 struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124 }; 125 126 static int kern_logsigexit = 1; 127 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131 static int kern_forcesigexit = 1; 132 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 136 "POSIX real time signal"); 137 138 static int max_pending_per_proc = 128; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 140 &max_pending_per_proc, 0, "Max pending signals per proc"); 141 142 static int preallocate_siginfo = 1024; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 static int kern_lognosys = 0; 155 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 156 "Log invalid syscalls"); 157 158 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160 /* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165 #define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172 static int sugid_coredump; 173 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176 static int capmode_coredump; 177 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180 static int do_coredump = 1; 181 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184 static int set_core_nodump_flag = 0; 185 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188 static int coredump_devctl = 0; 189 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192 /* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197 #define SIGPROP_KILL 0x01 /* terminates process by default */ 198 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 199 #define SIGPROP_STOP 0x04 /* suspend process */ 200 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 201 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 202 #define SIGPROP_CONT 0x20 /* continue if suspended */ 203 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 204 205 static int sigproptbl[NSIG] = { 206 [SIGHUP] = SIGPROP_KILL, 207 [SIGINT] = SIGPROP_KILL, 208 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 209 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGKILL] = SIGPROP_KILL, 215 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGPIPE] = SIGPROP_KILL, 219 [SIGALRM] = SIGPROP_KILL, 220 [SIGTERM] = SIGPROP_KILL, 221 [SIGURG] = SIGPROP_IGNORE, 222 [SIGSTOP] = SIGPROP_STOP, 223 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 224 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 225 [SIGCHLD] = SIGPROP_IGNORE, 226 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 227 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGIO] = SIGPROP_IGNORE, 229 [SIGXCPU] = SIGPROP_KILL, 230 [SIGXFSZ] = SIGPROP_KILL, 231 [SIGVTALRM] = SIGPROP_KILL, 232 [SIGPROF] = SIGPROP_KILL, 233 [SIGWINCH] = SIGPROP_IGNORE, 234 [SIGINFO] = SIGPROP_IGNORE, 235 [SIGUSR1] = SIGPROP_KILL, 236 [SIGUSR2] = SIGPROP_KILL, 237 }; 238 239 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241 static void 242 sigqueue_start(void) 243 { 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250 } 251 252 ksiginfo_t * 253 ksiginfo_alloc(int wait) 254 { 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263 } 264 265 void 266 ksiginfo_free(ksiginfo_t *ksi) 267 { 268 uma_zfree(ksiginfo_zone, ksi); 269 } 270 271 static __inline int 272 ksiginfo_tryfree(ksiginfo_t *ksi) 273 { 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279 } 280 281 void 282 sigqueue_init(sigqueue_t *list, struct proc *p) 283 { 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290 } 291 292 /* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298 static int 299 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300 { 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339 } 340 341 void 342 sigqueue_take(ksiginfo_t *ksi) 343 { 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365 } 366 367 static int 368 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369 { 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432 out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435 } 436 437 void 438 sigqueue_flush(sigqueue_t *sq) 439 { 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458 } 459 460 static void 461 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462 { 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499 } 500 501 #if 0 502 static void 503 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510 } 511 #endif 512 513 static void 514 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515 { 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533 } 534 535 void 536 sigqueue_delete(sigqueue_t *sq, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543 } 544 545 /* Remove a set of signals for a process */ 546 static void 547 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548 { 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561 } 562 563 void 564 sigqueue_delete_proc(struct proc *p, int signo) 565 { 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571 } 572 573 static void 574 sigqueue_delete_stopmask_proc(struct proc *p) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584 } 585 586 /* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591 int 592 cursig(struct thread *td) 593 { 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598 } 599 600 /* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605 void 606 signotify(struct thread *td) 607 { 608 struct proc *p; 609 610 p = td->td_proc; 611 612 PROC_LOCK_ASSERT(p, MA_OWNED); 613 614 if (SIGPENDING(td)) { 615 thread_lock(td); 616 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 617 thread_unlock(td); 618 } 619 } 620 621 int 622 sigonstack(size_t sp) 623 { 624 struct thread *td = curthread; 625 626 return ((td->td_pflags & TDP_ALTSTACK) ? 627 #if defined(COMPAT_43) 628 ((td->td_sigstk.ss_size == 0) ? 629 (td->td_sigstk.ss_flags & SS_ONSTACK) : 630 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 631 #else 632 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 633 #endif 634 : 0); 635 } 636 637 static __inline int 638 sigprop(int sig) 639 { 640 641 if (sig > 0 && sig < nitems(sigproptbl)) 642 return (sigproptbl[sig]); 643 return (0); 644 } 645 646 int 647 sig_ffs(sigset_t *set) 648 { 649 int i; 650 651 for (i = 0; i < _SIG_WORDS; i++) 652 if (set->__bits[i]) 653 return (ffs(set->__bits[i]) + (i * 32)); 654 return (0); 655 } 656 657 static bool 658 sigact_flag_test(const struct sigaction *act, int flag) 659 { 660 661 /* 662 * SA_SIGINFO is reset when signal disposition is set to 663 * ignore or default. Other flags are kept according to user 664 * settings. 665 */ 666 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 667 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 668 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 669 } 670 671 /* 672 * kern_sigaction 673 * sigaction 674 * freebsd4_sigaction 675 * osigaction 676 */ 677 int 678 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 679 struct sigaction *oact, int flags) 680 { 681 struct sigacts *ps; 682 struct proc *p = td->td_proc; 683 684 if (!_SIG_VALID(sig)) 685 return (EINVAL); 686 if (act != NULL && act->sa_handler != SIG_DFL && 687 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 688 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 689 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 690 return (EINVAL); 691 692 PROC_LOCK(p); 693 ps = p->p_sigacts; 694 mtx_lock(&ps->ps_mtx); 695 if (oact) { 696 memset(oact, 0, sizeof(*oact)); 697 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 698 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 699 oact->sa_flags |= SA_ONSTACK; 700 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 701 oact->sa_flags |= SA_RESTART; 702 if (SIGISMEMBER(ps->ps_sigreset, sig)) 703 oact->sa_flags |= SA_RESETHAND; 704 if (SIGISMEMBER(ps->ps_signodefer, sig)) 705 oact->sa_flags |= SA_NODEFER; 706 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 707 oact->sa_flags |= SA_SIGINFO; 708 oact->sa_sigaction = 709 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 710 } else 711 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 712 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 713 oact->sa_flags |= SA_NOCLDSTOP; 714 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 715 oact->sa_flags |= SA_NOCLDWAIT; 716 } 717 if (act) { 718 if ((sig == SIGKILL || sig == SIGSTOP) && 719 act->sa_handler != SIG_DFL) { 720 mtx_unlock(&ps->ps_mtx); 721 PROC_UNLOCK(p); 722 return (EINVAL); 723 } 724 725 /* 726 * Change setting atomically. 727 */ 728 729 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 730 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 731 if (sigact_flag_test(act, SA_SIGINFO)) { 732 ps->ps_sigact[_SIG_IDX(sig)] = 733 (__sighandler_t *)act->sa_sigaction; 734 SIGADDSET(ps->ps_siginfo, sig); 735 } else { 736 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 737 SIGDELSET(ps->ps_siginfo, sig); 738 } 739 if (!sigact_flag_test(act, SA_RESTART)) 740 SIGADDSET(ps->ps_sigintr, sig); 741 else 742 SIGDELSET(ps->ps_sigintr, sig); 743 if (sigact_flag_test(act, SA_ONSTACK)) 744 SIGADDSET(ps->ps_sigonstack, sig); 745 else 746 SIGDELSET(ps->ps_sigonstack, sig); 747 if (sigact_flag_test(act, SA_RESETHAND)) 748 SIGADDSET(ps->ps_sigreset, sig); 749 else 750 SIGDELSET(ps->ps_sigreset, sig); 751 if (sigact_flag_test(act, SA_NODEFER)) 752 SIGADDSET(ps->ps_signodefer, sig); 753 else 754 SIGDELSET(ps->ps_signodefer, sig); 755 if (sig == SIGCHLD) { 756 if (act->sa_flags & SA_NOCLDSTOP) 757 ps->ps_flag |= PS_NOCLDSTOP; 758 else 759 ps->ps_flag &= ~PS_NOCLDSTOP; 760 if (act->sa_flags & SA_NOCLDWAIT) { 761 /* 762 * Paranoia: since SA_NOCLDWAIT is implemented 763 * by reparenting the dying child to PID 1 (and 764 * trust it to reap the zombie), PID 1 itself 765 * is forbidden to set SA_NOCLDWAIT. 766 */ 767 if (p->p_pid == 1) 768 ps->ps_flag &= ~PS_NOCLDWAIT; 769 else 770 ps->ps_flag |= PS_NOCLDWAIT; 771 } else 772 ps->ps_flag &= ~PS_NOCLDWAIT; 773 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 774 ps->ps_flag |= PS_CLDSIGIGN; 775 else 776 ps->ps_flag &= ~PS_CLDSIGIGN; 777 } 778 /* 779 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 780 * and for signals set to SIG_DFL where the default is to 781 * ignore. However, don't put SIGCONT in ps_sigignore, as we 782 * have to restart the process. 783 */ 784 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 785 (sigprop(sig) & SIGPROP_IGNORE && 786 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 787 /* never to be seen again */ 788 sigqueue_delete_proc(p, sig); 789 if (sig != SIGCONT) 790 /* easier in psignal */ 791 SIGADDSET(ps->ps_sigignore, sig); 792 SIGDELSET(ps->ps_sigcatch, sig); 793 } else { 794 SIGDELSET(ps->ps_sigignore, sig); 795 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 796 SIGDELSET(ps->ps_sigcatch, sig); 797 else 798 SIGADDSET(ps->ps_sigcatch, sig); 799 } 800 #ifdef COMPAT_FREEBSD4 801 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 802 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 803 (flags & KSA_FREEBSD4) == 0) 804 SIGDELSET(ps->ps_freebsd4, sig); 805 else 806 SIGADDSET(ps->ps_freebsd4, sig); 807 #endif 808 #ifdef COMPAT_43 809 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 810 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 811 (flags & KSA_OSIGSET) == 0) 812 SIGDELSET(ps->ps_osigset, sig); 813 else 814 SIGADDSET(ps->ps_osigset, sig); 815 #endif 816 } 817 mtx_unlock(&ps->ps_mtx); 818 PROC_UNLOCK(p); 819 return (0); 820 } 821 822 #ifndef _SYS_SYSPROTO_H_ 823 struct sigaction_args { 824 int sig; 825 struct sigaction *act; 826 struct sigaction *oact; 827 }; 828 #endif 829 int 830 sys_sigaction(struct thread *td, struct sigaction_args *uap) 831 { 832 struct sigaction act, oact; 833 struct sigaction *actp, *oactp; 834 int error; 835 836 actp = (uap->act != NULL) ? &act : NULL; 837 oactp = (uap->oact != NULL) ? &oact : NULL; 838 if (actp) { 839 error = copyin(uap->act, actp, sizeof(act)); 840 if (error) 841 return (error); 842 } 843 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 844 if (oactp && !error) 845 error = copyout(oactp, uap->oact, sizeof(oact)); 846 return (error); 847 } 848 849 #ifdef COMPAT_FREEBSD4 850 #ifndef _SYS_SYSPROTO_H_ 851 struct freebsd4_sigaction_args { 852 int sig; 853 struct sigaction *act; 854 struct sigaction *oact; 855 }; 856 #endif 857 int 858 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 859 { 860 struct sigaction act, oact; 861 struct sigaction *actp, *oactp; 862 int error; 863 864 865 actp = (uap->act != NULL) ? &act : NULL; 866 oactp = (uap->oact != NULL) ? &oact : NULL; 867 if (actp) { 868 error = copyin(uap->act, actp, sizeof(act)); 869 if (error) 870 return (error); 871 } 872 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 873 if (oactp && !error) 874 error = copyout(oactp, uap->oact, sizeof(oact)); 875 return (error); 876 } 877 #endif /* COMAPT_FREEBSD4 */ 878 879 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 880 #ifndef _SYS_SYSPROTO_H_ 881 struct osigaction_args { 882 int signum; 883 struct osigaction *nsa; 884 struct osigaction *osa; 885 }; 886 #endif 887 int 888 osigaction(struct thread *td, struct osigaction_args *uap) 889 { 890 struct osigaction sa; 891 struct sigaction nsa, osa; 892 struct sigaction *nsap, *osap; 893 int error; 894 895 if (uap->signum <= 0 || uap->signum >= ONSIG) 896 return (EINVAL); 897 898 nsap = (uap->nsa != NULL) ? &nsa : NULL; 899 osap = (uap->osa != NULL) ? &osa : NULL; 900 901 if (nsap) { 902 error = copyin(uap->nsa, &sa, sizeof(sa)); 903 if (error) 904 return (error); 905 nsap->sa_handler = sa.sa_handler; 906 nsap->sa_flags = sa.sa_flags; 907 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 908 } 909 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 910 if (osap && !error) { 911 sa.sa_handler = osap->sa_handler; 912 sa.sa_flags = osap->sa_flags; 913 SIG2OSIG(osap->sa_mask, sa.sa_mask); 914 error = copyout(&sa, uap->osa, sizeof(sa)); 915 } 916 return (error); 917 } 918 919 #if !defined(__i386__) 920 /* Avoid replicating the same stub everywhere */ 921 int 922 osigreturn(struct thread *td, struct osigreturn_args *uap) 923 { 924 925 return (nosys(td, (struct nosys_args *)uap)); 926 } 927 #endif 928 #endif /* COMPAT_43 */ 929 930 /* 931 * Initialize signal state for process 0; 932 * set to ignore signals that are ignored by default. 933 */ 934 void 935 siginit(struct proc *p) 936 { 937 int i; 938 struct sigacts *ps; 939 940 PROC_LOCK(p); 941 ps = p->p_sigacts; 942 mtx_lock(&ps->ps_mtx); 943 for (i = 1; i <= NSIG; i++) { 944 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 945 SIGADDSET(ps->ps_sigignore, i); 946 } 947 } 948 mtx_unlock(&ps->ps_mtx); 949 PROC_UNLOCK(p); 950 } 951 952 /* 953 * Reset specified signal to the default disposition. 954 */ 955 static void 956 sigdflt(struct sigacts *ps, int sig) 957 { 958 959 mtx_assert(&ps->ps_mtx, MA_OWNED); 960 SIGDELSET(ps->ps_sigcatch, sig); 961 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 962 SIGADDSET(ps->ps_sigignore, sig); 963 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 964 SIGDELSET(ps->ps_siginfo, sig); 965 } 966 967 /* 968 * Reset signals for an exec of the specified process. 969 */ 970 void 971 execsigs(struct proc *p) 972 { 973 sigset_t osigignore; 974 struct sigacts *ps; 975 int sig; 976 struct thread *td; 977 978 /* 979 * Reset caught signals. Held signals remain held 980 * through td_sigmask (unless they were caught, 981 * and are now ignored by default). 982 */ 983 PROC_LOCK_ASSERT(p, MA_OWNED); 984 ps = p->p_sigacts; 985 mtx_lock(&ps->ps_mtx); 986 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 987 sig = sig_ffs(&ps->ps_sigcatch); 988 sigdflt(ps, sig); 989 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 990 sigqueue_delete_proc(p, sig); 991 } 992 993 /* 994 * As CloudABI processes cannot modify signal handlers, fully 995 * reset all signals to their default behavior. Do ignore 996 * SIGPIPE, as it would otherwise be impossible to recover from 997 * writes to broken pipes and sockets. 998 */ 999 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1000 osigignore = ps->ps_sigignore; 1001 while (SIGNOTEMPTY(osigignore)) { 1002 sig = sig_ffs(&osigignore); 1003 SIGDELSET(osigignore, sig); 1004 if (sig != SIGPIPE) 1005 sigdflt(ps, sig); 1006 } 1007 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1008 } 1009 1010 /* 1011 * Reset stack state to the user stack. 1012 * Clear set of signals caught on the signal stack. 1013 */ 1014 td = curthread; 1015 MPASS(td->td_proc == p); 1016 td->td_sigstk.ss_flags = SS_DISABLE; 1017 td->td_sigstk.ss_size = 0; 1018 td->td_sigstk.ss_sp = 0; 1019 td->td_pflags &= ~TDP_ALTSTACK; 1020 /* 1021 * Reset no zombies if child dies flag as Solaris does. 1022 */ 1023 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1024 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1025 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1026 mtx_unlock(&ps->ps_mtx); 1027 } 1028 1029 /* 1030 * kern_sigprocmask() 1031 * 1032 * Manipulate signal mask. 1033 */ 1034 int 1035 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1036 int flags) 1037 { 1038 sigset_t new_block, oset1; 1039 struct proc *p; 1040 int error; 1041 1042 p = td->td_proc; 1043 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1044 PROC_LOCK_ASSERT(p, MA_OWNED); 1045 else 1046 PROC_LOCK(p); 1047 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1048 ? MA_OWNED : MA_NOTOWNED); 1049 if (oset != NULL) 1050 *oset = td->td_sigmask; 1051 1052 error = 0; 1053 if (set != NULL) { 1054 switch (how) { 1055 case SIG_BLOCK: 1056 SIG_CANTMASK(*set); 1057 oset1 = td->td_sigmask; 1058 SIGSETOR(td->td_sigmask, *set); 1059 new_block = td->td_sigmask; 1060 SIGSETNAND(new_block, oset1); 1061 break; 1062 case SIG_UNBLOCK: 1063 SIGSETNAND(td->td_sigmask, *set); 1064 signotify(td); 1065 goto out; 1066 case SIG_SETMASK: 1067 SIG_CANTMASK(*set); 1068 oset1 = td->td_sigmask; 1069 if (flags & SIGPROCMASK_OLD) 1070 SIGSETLO(td->td_sigmask, *set); 1071 else 1072 td->td_sigmask = *set; 1073 new_block = td->td_sigmask; 1074 SIGSETNAND(new_block, oset1); 1075 signotify(td); 1076 break; 1077 default: 1078 error = EINVAL; 1079 goto out; 1080 } 1081 1082 /* 1083 * The new_block set contains signals that were not previously 1084 * blocked, but are blocked now. 1085 * 1086 * In case we block any signal that was not previously blocked 1087 * for td, and process has the signal pending, try to schedule 1088 * signal delivery to some thread that does not block the 1089 * signal, possibly waking it up. 1090 */ 1091 if (p->p_numthreads != 1) 1092 reschedule_signals(p, new_block, flags); 1093 } 1094 1095 out: 1096 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1097 PROC_UNLOCK(p); 1098 return (error); 1099 } 1100 1101 #ifndef _SYS_SYSPROTO_H_ 1102 struct sigprocmask_args { 1103 int how; 1104 const sigset_t *set; 1105 sigset_t *oset; 1106 }; 1107 #endif 1108 int 1109 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1110 { 1111 sigset_t set, oset; 1112 sigset_t *setp, *osetp; 1113 int error; 1114 1115 setp = (uap->set != NULL) ? &set : NULL; 1116 osetp = (uap->oset != NULL) ? &oset : NULL; 1117 if (setp) { 1118 error = copyin(uap->set, setp, sizeof(set)); 1119 if (error) 1120 return (error); 1121 } 1122 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1123 if (osetp && !error) { 1124 error = copyout(osetp, uap->oset, sizeof(oset)); 1125 } 1126 return (error); 1127 } 1128 1129 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1130 #ifndef _SYS_SYSPROTO_H_ 1131 struct osigprocmask_args { 1132 int how; 1133 osigset_t mask; 1134 }; 1135 #endif 1136 int 1137 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1138 { 1139 sigset_t set, oset; 1140 int error; 1141 1142 OSIG2SIG(uap->mask, set); 1143 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1144 SIG2OSIG(oset, td->td_retval[0]); 1145 return (error); 1146 } 1147 #endif /* COMPAT_43 */ 1148 1149 int 1150 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1151 { 1152 ksiginfo_t ksi; 1153 sigset_t set; 1154 int error; 1155 1156 error = copyin(uap->set, &set, sizeof(set)); 1157 if (error) { 1158 td->td_retval[0] = error; 1159 return (0); 1160 } 1161 1162 error = kern_sigtimedwait(td, set, &ksi, NULL); 1163 if (error) { 1164 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1165 error = ERESTART; 1166 if (error == ERESTART) 1167 return (error); 1168 td->td_retval[0] = error; 1169 return (0); 1170 } 1171 1172 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1173 td->td_retval[0] = error; 1174 return (0); 1175 } 1176 1177 int 1178 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1179 { 1180 struct timespec ts; 1181 struct timespec *timeout; 1182 sigset_t set; 1183 ksiginfo_t ksi; 1184 int error; 1185 1186 if (uap->timeout) { 1187 error = copyin(uap->timeout, &ts, sizeof(ts)); 1188 if (error) 1189 return (error); 1190 1191 timeout = &ts; 1192 } else 1193 timeout = NULL; 1194 1195 error = copyin(uap->set, &set, sizeof(set)); 1196 if (error) 1197 return (error); 1198 1199 error = kern_sigtimedwait(td, set, &ksi, timeout); 1200 if (error) 1201 return (error); 1202 1203 if (uap->info) 1204 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1205 1206 if (error == 0) 1207 td->td_retval[0] = ksi.ksi_signo; 1208 return (error); 1209 } 1210 1211 int 1212 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1213 { 1214 ksiginfo_t ksi; 1215 sigset_t set; 1216 int error; 1217 1218 error = copyin(uap->set, &set, sizeof(set)); 1219 if (error) 1220 return (error); 1221 1222 error = kern_sigtimedwait(td, set, &ksi, NULL); 1223 if (error) 1224 return (error); 1225 1226 if (uap->info) 1227 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1228 1229 if (error == 0) 1230 td->td_retval[0] = ksi.ksi_signo; 1231 return (error); 1232 } 1233 1234 static void 1235 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1236 { 1237 struct thread *thr; 1238 1239 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1240 if (thr == td) 1241 thr->td_si = *si; 1242 else 1243 thr->td_si.si_signo = 0; 1244 } 1245 } 1246 1247 int 1248 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1249 struct timespec *timeout) 1250 { 1251 struct sigacts *ps; 1252 sigset_t saved_mask, new_block; 1253 struct proc *p; 1254 int error, sig, timo, timevalid = 0; 1255 struct timespec rts, ets, ts; 1256 struct timeval tv; 1257 1258 p = td->td_proc; 1259 error = 0; 1260 ets.tv_sec = 0; 1261 ets.tv_nsec = 0; 1262 1263 if (timeout != NULL) { 1264 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1265 timevalid = 1; 1266 getnanouptime(&rts); 1267 ets = rts; 1268 timespecadd(&ets, timeout); 1269 } 1270 } 1271 ksiginfo_init(ksi); 1272 /* Some signals can not be waited for. */ 1273 SIG_CANTMASK(waitset); 1274 ps = p->p_sigacts; 1275 PROC_LOCK(p); 1276 saved_mask = td->td_sigmask; 1277 SIGSETNAND(td->td_sigmask, waitset); 1278 for (;;) { 1279 mtx_lock(&ps->ps_mtx); 1280 sig = cursig(td); 1281 mtx_unlock(&ps->ps_mtx); 1282 KASSERT(sig >= 0, ("sig %d", sig)); 1283 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1284 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1285 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1286 error = 0; 1287 break; 1288 } 1289 } 1290 1291 if (error != 0) 1292 break; 1293 1294 /* 1295 * POSIX says this must be checked after looking for pending 1296 * signals. 1297 */ 1298 if (timeout != NULL) { 1299 if (!timevalid) { 1300 error = EINVAL; 1301 break; 1302 } 1303 getnanouptime(&rts); 1304 if (timespeccmp(&rts, &ets, >=)) { 1305 error = EAGAIN; 1306 break; 1307 } 1308 ts = ets; 1309 timespecsub(&ts, &rts); 1310 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1311 timo = tvtohz(&tv); 1312 } else { 1313 timo = 0; 1314 } 1315 1316 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1317 1318 if (timeout != NULL) { 1319 if (error == ERESTART) { 1320 /* Timeout can not be restarted. */ 1321 error = EINTR; 1322 } else if (error == EAGAIN) { 1323 /* We will calculate timeout by ourself. */ 1324 error = 0; 1325 } 1326 } 1327 } 1328 1329 new_block = saved_mask; 1330 SIGSETNAND(new_block, td->td_sigmask); 1331 td->td_sigmask = saved_mask; 1332 /* 1333 * Fewer signals can be delivered to us, reschedule signal 1334 * notification. 1335 */ 1336 if (p->p_numthreads != 1) 1337 reschedule_signals(p, new_block, 0); 1338 1339 if (error == 0) { 1340 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1341 1342 if (ksi->ksi_code == SI_TIMER) 1343 itimer_accept(p, ksi->ksi_timerid, ksi); 1344 1345 #ifdef KTRACE 1346 if (KTRPOINT(td, KTR_PSIG)) { 1347 sig_t action; 1348 1349 mtx_lock(&ps->ps_mtx); 1350 action = ps->ps_sigact[_SIG_IDX(sig)]; 1351 mtx_unlock(&ps->ps_mtx); 1352 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1353 } 1354 #endif 1355 if (sig == SIGKILL) { 1356 proc_td_siginfo_capture(td, &ksi->ksi_info); 1357 sigexit(td, sig); 1358 } 1359 } 1360 PROC_UNLOCK(p); 1361 return (error); 1362 } 1363 1364 #ifndef _SYS_SYSPROTO_H_ 1365 struct sigpending_args { 1366 sigset_t *set; 1367 }; 1368 #endif 1369 int 1370 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1371 { 1372 struct proc *p = td->td_proc; 1373 sigset_t pending; 1374 1375 PROC_LOCK(p); 1376 pending = p->p_sigqueue.sq_signals; 1377 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1378 PROC_UNLOCK(p); 1379 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1380 } 1381 1382 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigpending_args { 1385 int dummy; 1386 }; 1387 #endif 1388 int 1389 osigpending(struct thread *td, struct osigpending_args *uap) 1390 { 1391 struct proc *p = td->td_proc; 1392 sigset_t pending; 1393 1394 PROC_LOCK(p); 1395 pending = p->p_sigqueue.sq_signals; 1396 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1397 PROC_UNLOCK(p); 1398 SIG2OSIG(pending, td->td_retval[0]); 1399 return (0); 1400 } 1401 #endif /* COMPAT_43 */ 1402 1403 #if defined(COMPAT_43) 1404 /* 1405 * Generalized interface signal handler, 4.3-compatible. 1406 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigvec_args { 1409 int signum; 1410 struct sigvec *nsv; 1411 struct sigvec *osv; 1412 }; 1413 #endif 1414 /* ARGSUSED */ 1415 int 1416 osigvec(struct thread *td, struct osigvec_args *uap) 1417 { 1418 struct sigvec vec; 1419 struct sigaction nsa, osa; 1420 struct sigaction *nsap, *osap; 1421 int error; 1422 1423 if (uap->signum <= 0 || uap->signum >= ONSIG) 1424 return (EINVAL); 1425 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1426 osap = (uap->osv != NULL) ? &osa : NULL; 1427 if (nsap) { 1428 error = copyin(uap->nsv, &vec, sizeof(vec)); 1429 if (error) 1430 return (error); 1431 nsap->sa_handler = vec.sv_handler; 1432 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1433 nsap->sa_flags = vec.sv_flags; 1434 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1435 } 1436 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1437 if (osap && !error) { 1438 vec.sv_handler = osap->sa_handler; 1439 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1440 vec.sv_flags = osap->sa_flags; 1441 vec.sv_flags &= ~SA_NOCLDWAIT; 1442 vec.sv_flags ^= SA_RESTART; 1443 error = copyout(&vec, uap->osv, sizeof(vec)); 1444 } 1445 return (error); 1446 } 1447 1448 #ifndef _SYS_SYSPROTO_H_ 1449 struct osigblock_args { 1450 int mask; 1451 }; 1452 #endif 1453 int 1454 osigblock(struct thread *td, struct osigblock_args *uap) 1455 { 1456 sigset_t set, oset; 1457 1458 OSIG2SIG(uap->mask, set); 1459 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1460 SIG2OSIG(oset, td->td_retval[0]); 1461 return (0); 1462 } 1463 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct osigsetmask_args { 1466 int mask; 1467 }; 1468 #endif 1469 int 1470 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1471 { 1472 sigset_t set, oset; 1473 1474 OSIG2SIG(uap->mask, set); 1475 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1476 SIG2OSIG(oset, td->td_retval[0]); 1477 return (0); 1478 } 1479 #endif /* COMPAT_43 */ 1480 1481 /* 1482 * Suspend calling thread until signal, providing mask to be set in the 1483 * meantime. 1484 */ 1485 #ifndef _SYS_SYSPROTO_H_ 1486 struct sigsuspend_args { 1487 const sigset_t *sigmask; 1488 }; 1489 #endif 1490 /* ARGSUSED */ 1491 int 1492 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1493 { 1494 sigset_t mask; 1495 int error; 1496 1497 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1498 if (error) 1499 return (error); 1500 return (kern_sigsuspend(td, mask)); 1501 } 1502 1503 int 1504 kern_sigsuspend(struct thread *td, sigset_t mask) 1505 { 1506 struct proc *p = td->td_proc; 1507 int has_sig, sig; 1508 1509 /* 1510 * When returning from sigsuspend, we want 1511 * the old mask to be restored after the 1512 * signal handler has finished. Thus, we 1513 * save it here and mark the sigacts structure 1514 * to indicate this. 1515 */ 1516 PROC_LOCK(p); 1517 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1518 SIGPROCMASK_PROC_LOCKED); 1519 td->td_pflags |= TDP_OLDMASK; 1520 1521 /* 1522 * Process signals now. Otherwise, we can get spurious wakeup 1523 * due to signal entered process queue, but delivered to other 1524 * thread. But sigsuspend should return only on signal 1525 * delivery. 1526 */ 1527 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1528 for (has_sig = 0; !has_sig;) { 1529 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1530 0) == 0) 1531 /* void */; 1532 thread_suspend_check(0); 1533 mtx_lock(&p->p_sigacts->ps_mtx); 1534 while ((sig = cursig(td)) != 0) { 1535 KASSERT(sig >= 0, ("sig %d", sig)); 1536 has_sig += postsig(sig); 1537 } 1538 mtx_unlock(&p->p_sigacts->ps_mtx); 1539 } 1540 PROC_UNLOCK(p); 1541 td->td_errno = EINTR; 1542 td->td_pflags |= TDP_NERRNO; 1543 return (EJUSTRETURN); 1544 } 1545 1546 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1547 /* 1548 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1549 * convention: libc stub passes mask, not pointer, to save a copyin. 1550 */ 1551 #ifndef _SYS_SYSPROTO_H_ 1552 struct osigsuspend_args { 1553 osigset_t mask; 1554 }; 1555 #endif 1556 /* ARGSUSED */ 1557 int 1558 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1559 { 1560 sigset_t mask; 1561 1562 OSIG2SIG(uap->mask, mask); 1563 return (kern_sigsuspend(td, mask)); 1564 } 1565 #endif /* COMPAT_43 */ 1566 1567 #if defined(COMPAT_43) 1568 #ifndef _SYS_SYSPROTO_H_ 1569 struct osigstack_args { 1570 struct sigstack *nss; 1571 struct sigstack *oss; 1572 }; 1573 #endif 1574 /* ARGSUSED */ 1575 int 1576 osigstack(struct thread *td, struct osigstack_args *uap) 1577 { 1578 struct sigstack nss, oss; 1579 int error = 0; 1580 1581 if (uap->nss != NULL) { 1582 error = copyin(uap->nss, &nss, sizeof(nss)); 1583 if (error) 1584 return (error); 1585 } 1586 oss.ss_sp = td->td_sigstk.ss_sp; 1587 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1588 if (uap->nss != NULL) { 1589 td->td_sigstk.ss_sp = nss.ss_sp; 1590 td->td_sigstk.ss_size = 0; 1591 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1592 td->td_pflags |= TDP_ALTSTACK; 1593 } 1594 if (uap->oss != NULL) 1595 error = copyout(&oss, uap->oss, sizeof(oss)); 1596 1597 return (error); 1598 } 1599 #endif /* COMPAT_43 */ 1600 1601 #ifndef _SYS_SYSPROTO_H_ 1602 struct sigaltstack_args { 1603 stack_t *ss; 1604 stack_t *oss; 1605 }; 1606 #endif 1607 /* ARGSUSED */ 1608 int 1609 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1610 { 1611 stack_t ss, oss; 1612 int error; 1613 1614 if (uap->ss != NULL) { 1615 error = copyin(uap->ss, &ss, sizeof(ss)); 1616 if (error) 1617 return (error); 1618 } 1619 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1620 (uap->oss != NULL) ? &oss : NULL); 1621 if (error) 1622 return (error); 1623 if (uap->oss != NULL) 1624 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1625 return (error); 1626 } 1627 1628 int 1629 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1630 { 1631 struct proc *p = td->td_proc; 1632 int oonstack; 1633 1634 oonstack = sigonstack(cpu_getstack(td)); 1635 1636 if (oss != NULL) { 1637 *oss = td->td_sigstk; 1638 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1639 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1640 } 1641 1642 if (ss != NULL) { 1643 if (oonstack) 1644 return (EPERM); 1645 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1646 return (EINVAL); 1647 if (!(ss->ss_flags & SS_DISABLE)) { 1648 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1649 return (ENOMEM); 1650 1651 td->td_sigstk = *ss; 1652 td->td_pflags |= TDP_ALTSTACK; 1653 } else { 1654 td->td_pflags &= ~TDP_ALTSTACK; 1655 } 1656 } 1657 return (0); 1658 } 1659 1660 /* 1661 * Common code for kill process group/broadcast kill. 1662 * cp is calling process. 1663 */ 1664 static int 1665 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1666 { 1667 struct proc *p; 1668 struct pgrp *pgrp; 1669 int err; 1670 int ret; 1671 1672 ret = ESRCH; 1673 if (all) { 1674 /* 1675 * broadcast 1676 */ 1677 sx_slock(&allproc_lock); 1678 FOREACH_PROC_IN_SYSTEM(p) { 1679 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1680 p == td->td_proc || p->p_state == PRS_NEW) { 1681 continue; 1682 } 1683 PROC_LOCK(p); 1684 err = p_cansignal(td, p, sig); 1685 if (err == 0) { 1686 if (sig) 1687 pksignal(p, sig, ksi); 1688 ret = err; 1689 } 1690 else if (ret == ESRCH) 1691 ret = err; 1692 PROC_UNLOCK(p); 1693 } 1694 sx_sunlock(&allproc_lock); 1695 } else { 1696 sx_slock(&proctree_lock); 1697 if (pgid == 0) { 1698 /* 1699 * zero pgid means send to my process group. 1700 */ 1701 pgrp = td->td_proc->p_pgrp; 1702 PGRP_LOCK(pgrp); 1703 } else { 1704 pgrp = pgfind(pgid); 1705 if (pgrp == NULL) { 1706 sx_sunlock(&proctree_lock); 1707 return (ESRCH); 1708 } 1709 } 1710 sx_sunlock(&proctree_lock); 1711 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1712 PROC_LOCK(p); 1713 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1714 p->p_state == PRS_NEW) { 1715 PROC_UNLOCK(p); 1716 continue; 1717 } 1718 err = p_cansignal(td, p, sig); 1719 if (err == 0) { 1720 if (sig) 1721 pksignal(p, sig, ksi); 1722 ret = err; 1723 } 1724 else if (ret == ESRCH) 1725 ret = err; 1726 PROC_UNLOCK(p); 1727 } 1728 PGRP_UNLOCK(pgrp); 1729 } 1730 return (ret); 1731 } 1732 1733 #ifndef _SYS_SYSPROTO_H_ 1734 struct kill_args { 1735 int pid; 1736 int signum; 1737 }; 1738 #endif 1739 /* ARGSUSED */ 1740 int 1741 sys_kill(struct thread *td, struct kill_args *uap) 1742 { 1743 ksiginfo_t ksi; 1744 struct proc *p; 1745 int error; 1746 1747 /* 1748 * A process in capability mode can send signals only to himself. 1749 * The main rationale behind this is that abort(3) is implemented as 1750 * kill(getpid(), SIGABRT). 1751 */ 1752 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1753 return (ECAPMODE); 1754 1755 AUDIT_ARG_SIGNUM(uap->signum); 1756 AUDIT_ARG_PID(uap->pid); 1757 if ((u_int)uap->signum > _SIG_MAXSIG) 1758 return (EINVAL); 1759 1760 ksiginfo_init(&ksi); 1761 ksi.ksi_signo = uap->signum; 1762 ksi.ksi_code = SI_USER; 1763 ksi.ksi_pid = td->td_proc->p_pid; 1764 ksi.ksi_uid = td->td_ucred->cr_ruid; 1765 1766 if (uap->pid > 0) { 1767 /* kill single process */ 1768 if ((p = pfind_any(uap->pid)) == NULL) 1769 return (ESRCH); 1770 AUDIT_ARG_PROCESS(p); 1771 error = p_cansignal(td, p, uap->signum); 1772 if (error == 0 && uap->signum) 1773 pksignal(p, uap->signum, &ksi); 1774 PROC_UNLOCK(p); 1775 return (error); 1776 } 1777 switch (uap->pid) { 1778 case -1: /* broadcast signal */ 1779 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1780 case 0: /* signal own process group */ 1781 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1782 default: /* negative explicit process group */ 1783 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1784 } 1785 /* NOTREACHED */ 1786 } 1787 1788 int 1789 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1790 { 1791 struct proc *p; 1792 cap_rights_t rights; 1793 int error; 1794 1795 AUDIT_ARG_SIGNUM(uap->signum); 1796 AUDIT_ARG_FD(uap->fd); 1797 if ((u_int)uap->signum > _SIG_MAXSIG) 1798 return (EINVAL); 1799 1800 error = procdesc_find(td, uap->fd, 1801 cap_rights_init(&rights, CAP_PDKILL), &p); 1802 if (error) 1803 return (error); 1804 AUDIT_ARG_PROCESS(p); 1805 error = p_cansignal(td, p, uap->signum); 1806 if (error == 0 && uap->signum) 1807 kern_psignal(p, uap->signum); 1808 PROC_UNLOCK(p); 1809 return (error); 1810 } 1811 1812 #if defined(COMPAT_43) 1813 #ifndef _SYS_SYSPROTO_H_ 1814 struct okillpg_args { 1815 int pgid; 1816 int signum; 1817 }; 1818 #endif 1819 /* ARGSUSED */ 1820 int 1821 okillpg(struct thread *td, struct okillpg_args *uap) 1822 { 1823 ksiginfo_t ksi; 1824 1825 AUDIT_ARG_SIGNUM(uap->signum); 1826 AUDIT_ARG_PID(uap->pgid); 1827 if ((u_int)uap->signum > _SIG_MAXSIG) 1828 return (EINVAL); 1829 1830 ksiginfo_init(&ksi); 1831 ksi.ksi_signo = uap->signum; 1832 ksi.ksi_code = SI_USER; 1833 ksi.ksi_pid = td->td_proc->p_pid; 1834 ksi.ksi_uid = td->td_ucred->cr_ruid; 1835 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1836 } 1837 #endif /* COMPAT_43 */ 1838 1839 #ifndef _SYS_SYSPROTO_H_ 1840 struct sigqueue_args { 1841 pid_t pid; 1842 int signum; 1843 /* union sigval */ void *value; 1844 }; 1845 #endif 1846 int 1847 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1848 { 1849 union sigval sv; 1850 1851 sv.sival_ptr = uap->value; 1852 1853 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1854 } 1855 1856 int 1857 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1858 { 1859 ksiginfo_t ksi; 1860 struct proc *p; 1861 int error; 1862 1863 if ((u_int)signum > _SIG_MAXSIG) 1864 return (EINVAL); 1865 1866 /* 1867 * Specification says sigqueue can only send signal to 1868 * single process. 1869 */ 1870 if (pid <= 0) 1871 return (EINVAL); 1872 1873 if ((p = pfind_any(pid)) == NULL) 1874 return (ESRCH); 1875 error = p_cansignal(td, p, signum); 1876 if (error == 0 && signum != 0) { 1877 ksiginfo_init(&ksi); 1878 ksi.ksi_flags = KSI_SIGQ; 1879 ksi.ksi_signo = signum; 1880 ksi.ksi_code = SI_QUEUE; 1881 ksi.ksi_pid = td->td_proc->p_pid; 1882 ksi.ksi_uid = td->td_ucred->cr_ruid; 1883 ksi.ksi_value = *value; 1884 error = pksignal(p, ksi.ksi_signo, &ksi); 1885 } 1886 PROC_UNLOCK(p); 1887 return (error); 1888 } 1889 1890 /* 1891 * Send a signal to a process group. 1892 */ 1893 void 1894 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1895 { 1896 struct pgrp *pgrp; 1897 1898 if (pgid != 0) { 1899 sx_slock(&proctree_lock); 1900 pgrp = pgfind(pgid); 1901 sx_sunlock(&proctree_lock); 1902 if (pgrp != NULL) { 1903 pgsignal(pgrp, sig, 0, ksi); 1904 PGRP_UNLOCK(pgrp); 1905 } 1906 } 1907 } 1908 1909 /* 1910 * Send a signal to a process group. If checktty is 1, 1911 * limit to members which have a controlling terminal. 1912 */ 1913 void 1914 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1915 { 1916 struct proc *p; 1917 1918 if (pgrp) { 1919 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1920 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1921 PROC_LOCK(p); 1922 if (p->p_state == PRS_NORMAL && 1923 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1924 pksignal(p, sig, ksi); 1925 PROC_UNLOCK(p); 1926 } 1927 } 1928 } 1929 1930 1931 /* 1932 * Recalculate the signal mask and reset the signal disposition after 1933 * usermode frame for delivery is formed. Should be called after 1934 * mach-specific routine, because sysent->sv_sendsig() needs correct 1935 * ps_siginfo and signal mask. 1936 */ 1937 static void 1938 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1939 { 1940 sigset_t mask; 1941 1942 mtx_assert(&ps->ps_mtx, MA_OWNED); 1943 td->td_ru.ru_nsignals++; 1944 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1945 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1946 SIGADDSET(mask, sig); 1947 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1948 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1949 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1950 sigdflt(ps, sig); 1951 } 1952 1953 1954 /* 1955 * Send a signal caused by a trap to the current thread. If it will be 1956 * caught immediately, deliver it with correct code. Otherwise, post it 1957 * normally. 1958 */ 1959 void 1960 trapsignal(struct thread *td, ksiginfo_t *ksi) 1961 { 1962 struct sigacts *ps; 1963 struct proc *p; 1964 int sig; 1965 int code; 1966 1967 p = td->td_proc; 1968 sig = ksi->ksi_signo; 1969 code = ksi->ksi_code; 1970 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1971 1972 PROC_LOCK(p); 1973 ps = p->p_sigacts; 1974 mtx_lock(&ps->ps_mtx); 1975 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1976 !SIGISMEMBER(td->td_sigmask, sig)) { 1977 #ifdef KTRACE 1978 if (KTRPOINT(curthread, KTR_PSIG)) 1979 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1980 &td->td_sigmask, code); 1981 #endif 1982 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1983 ksi, &td->td_sigmask); 1984 postsig_done(sig, td, ps); 1985 mtx_unlock(&ps->ps_mtx); 1986 } else { 1987 /* 1988 * Avoid a possible infinite loop if the thread 1989 * masking the signal or process is ignoring the 1990 * signal. 1991 */ 1992 if (kern_forcesigexit && 1993 (SIGISMEMBER(td->td_sigmask, sig) || 1994 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1995 SIGDELSET(td->td_sigmask, sig); 1996 SIGDELSET(ps->ps_sigcatch, sig); 1997 SIGDELSET(ps->ps_sigignore, sig); 1998 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1999 } 2000 mtx_unlock(&ps->ps_mtx); 2001 p->p_code = code; /* XXX for core dump/debugger */ 2002 p->p_sig = sig; /* XXX to verify code */ 2003 tdsendsignal(p, td, sig, ksi); 2004 } 2005 PROC_UNLOCK(p); 2006 } 2007 2008 static struct thread * 2009 sigtd(struct proc *p, int sig, int prop) 2010 { 2011 struct thread *td, *signal_td; 2012 2013 PROC_LOCK_ASSERT(p, MA_OWNED); 2014 2015 /* 2016 * Check if current thread can handle the signal without 2017 * switching context to another thread. 2018 */ 2019 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2020 return (curthread); 2021 signal_td = NULL; 2022 FOREACH_THREAD_IN_PROC(p, td) { 2023 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2024 signal_td = td; 2025 break; 2026 } 2027 } 2028 if (signal_td == NULL) 2029 signal_td = FIRST_THREAD_IN_PROC(p); 2030 return (signal_td); 2031 } 2032 2033 /* 2034 * Send the signal to the process. If the signal has an action, the action 2035 * is usually performed by the target process rather than the caller; we add 2036 * the signal to the set of pending signals for the process. 2037 * 2038 * Exceptions: 2039 * o When a stop signal is sent to a sleeping process that takes the 2040 * default action, the process is stopped without awakening it. 2041 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2042 * regardless of the signal action (eg, blocked or ignored). 2043 * 2044 * Other ignored signals are discarded immediately. 2045 * 2046 * NB: This function may be entered from the debugger via the "kill" DDB 2047 * command. There is little that can be done to mitigate the possibly messy 2048 * side effects of this unwise possibility. 2049 */ 2050 void 2051 kern_psignal(struct proc *p, int sig) 2052 { 2053 ksiginfo_t ksi; 2054 2055 ksiginfo_init(&ksi); 2056 ksi.ksi_signo = sig; 2057 ksi.ksi_code = SI_KERNEL; 2058 (void) tdsendsignal(p, NULL, sig, &ksi); 2059 } 2060 2061 int 2062 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2063 { 2064 2065 return (tdsendsignal(p, NULL, sig, ksi)); 2066 } 2067 2068 /* Utility function for finding a thread to send signal event to. */ 2069 int 2070 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2071 { 2072 struct thread *td; 2073 2074 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2075 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2076 if (td == NULL) 2077 return (ESRCH); 2078 *ttd = td; 2079 } else { 2080 *ttd = NULL; 2081 PROC_LOCK(p); 2082 } 2083 return (0); 2084 } 2085 2086 void 2087 tdsignal(struct thread *td, int sig) 2088 { 2089 ksiginfo_t ksi; 2090 2091 ksiginfo_init(&ksi); 2092 ksi.ksi_signo = sig; 2093 ksi.ksi_code = SI_KERNEL; 2094 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2095 } 2096 2097 void 2098 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2099 { 2100 2101 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2102 } 2103 2104 int 2105 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2106 { 2107 sig_t action; 2108 sigqueue_t *sigqueue; 2109 int prop; 2110 struct sigacts *ps; 2111 int intrval; 2112 int ret = 0; 2113 int wakeup_swapper; 2114 2115 MPASS(td == NULL || p == td->td_proc); 2116 PROC_LOCK_ASSERT(p, MA_OWNED); 2117 2118 if (!_SIG_VALID(sig)) 2119 panic("%s(): invalid signal %d", __func__, sig); 2120 2121 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2122 2123 /* 2124 * IEEE Std 1003.1-2001: return success when killing a zombie. 2125 */ 2126 if (p->p_state == PRS_ZOMBIE) { 2127 if (ksi && (ksi->ksi_flags & KSI_INS)) 2128 ksiginfo_tryfree(ksi); 2129 return (ret); 2130 } 2131 2132 ps = p->p_sigacts; 2133 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2134 prop = sigprop(sig); 2135 2136 if (td == NULL) { 2137 td = sigtd(p, sig, prop); 2138 sigqueue = &p->p_sigqueue; 2139 } else 2140 sigqueue = &td->td_sigqueue; 2141 2142 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2143 2144 /* 2145 * If the signal is being ignored, 2146 * then we forget about it immediately. 2147 * (Note: we don't set SIGCONT in ps_sigignore, 2148 * and if it is set to SIG_IGN, 2149 * action will be SIG_DFL here.) 2150 */ 2151 mtx_lock(&ps->ps_mtx); 2152 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2153 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2154 2155 mtx_unlock(&ps->ps_mtx); 2156 if (ksi && (ksi->ksi_flags & KSI_INS)) 2157 ksiginfo_tryfree(ksi); 2158 return (ret); 2159 } 2160 if (SIGISMEMBER(td->td_sigmask, sig)) 2161 action = SIG_HOLD; 2162 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2163 action = SIG_CATCH; 2164 else 2165 action = SIG_DFL; 2166 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2167 intrval = EINTR; 2168 else 2169 intrval = ERESTART; 2170 mtx_unlock(&ps->ps_mtx); 2171 2172 if (prop & SIGPROP_CONT) 2173 sigqueue_delete_stopmask_proc(p); 2174 else if (prop & SIGPROP_STOP) { 2175 /* 2176 * If sending a tty stop signal to a member of an orphaned 2177 * process group, discard the signal here if the action 2178 * is default; don't stop the process below if sleeping, 2179 * and don't clear any pending SIGCONT. 2180 */ 2181 if ((prop & SIGPROP_TTYSTOP) && 2182 (p->p_pgrp->pg_jobc == 0) && 2183 (action == SIG_DFL)) { 2184 if (ksi && (ksi->ksi_flags & KSI_INS)) 2185 ksiginfo_tryfree(ksi); 2186 return (ret); 2187 } 2188 sigqueue_delete_proc(p, SIGCONT); 2189 if (p->p_flag & P_CONTINUED) { 2190 p->p_flag &= ~P_CONTINUED; 2191 PROC_LOCK(p->p_pptr); 2192 sigqueue_take(p->p_ksi); 2193 PROC_UNLOCK(p->p_pptr); 2194 } 2195 } 2196 2197 ret = sigqueue_add(sigqueue, sig, ksi); 2198 if (ret != 0) 2199 return (ret); 2200 signotify(td); 2201 /* 2202 * Defer further processing for signals which are held, 2203 * except that stopped processes must be continued by SIGCONT. 2204 */ 2205 if (action == SIG_HOLD && 2206 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2207 return (ret); 2208 2209 /* SIGKILL: Remove procfs STOPEVENTs. */ 2210 if (sig == SIGKILL) { 2211 /* from procfs_ioctl.c: PIOCBIC */ 2212 p->p_stops = 0; 2213 /* from procfs_ioctl.c: PIOCCONT */ 2214 p->p_step = 0; 2215 wakeup(&p->p_step); 2216 } 2217 /* 2218 * Some signals have a process-wide effect and a per-thread 2219 * component. Most processing occurs when the process next 2220 * tries to cross the user boundary, however there are some 2221 * times when processing needs to be done immediately, such as 2222 * waking up threads so that they can cross the user boundary. 2223 * We try to do the per-process part here. 2224 */ 2225 if (P_SHOULDSTOP(p)) { 2226 KASSERT(!(p->p_flag & P_WEXIT), 2227 ("signal to stopped but exiting process")); 2228 if (sig == SIGKILL) { 2229 /* 2230 * If traced process is already stopped, 2231 * then no further action is necessary. 2232 */ 2233 if (p->p_flag & P_TRACED) 2234 goto out; 2235 /* 2236 * SIGKILL sets process running. 2237 * It will die elsewhere. 2238 * All threads must be restarted. 2239 */ 2240 p->p_flag &= ~P_STOPPED_SIG; 2241 goto runfast; 2242 } 2243 2244 if (prop & SIGPROP_CONT) { 2245 /* 2246 * If traced process is already stopped, 2247 * then no further action is necessary. 2248 */ 2249 if (p->p_flag & P_TRACED) 2250 goto out; 2251 /* 2252 * If SIGCONT is default (or ignored), we continue the 2253 * process but don't leave the signal in sigqueue as 2254 * it has no further action. If SIGCONT is held, we 2255 * continue the process and leave the signal in 2256 * sigqueue. If the process catches SIGCONT, let it 2257 * handle the signal itself. If it isn't waiting on 2258 * an event, it goes back to run state. 2259 * Otherwise, process goes back to sleep state. 2260 */ 2261 p->p_flag &= ~P_STOPPED_SIG; 2262 PROC_SLOCK(p); 2263 if (p->p_numthreads == p->p_suspcount) { 2264 PROC_SUNLOCK(p); 2265 p->p_flag |= P_CONTINUED; 2266 p->p_xsig = SIGCONT; 2267 PROC_LOCK(p->p_pptr); 2268 childproc_continued(p); 2269 PROC_UNLOCK(p->p_pptr); 2270 PROC_SLOCK(p); 2271 } 2272 if (action == SIG_DFL) { 2273 thread_unsuspend(p); 2274 PROC_SUNLOCK(p); 2275 sigqueue_delete(sigqueue, sig); 2276 goto out; 2277 } 2278 if (action == SIG_CATCH) { 2279 /* 2280 * The process wants to catch it so it needs 2281 * to run at least one thread, but which one? 2282 */ 2283 PROC_SUNLOCK(p); 2284 goto runfast; 2285 } 2286 /* 2287 * The signal is not ignored or caught. 2288 */ 2289 thread_unsuspend(p); 2290 PROC_SUNLOCK(p); 2291 goto out; 2292 } 2293 2294 if (prop & SIGPROP_STOP) { 2295 /* 2296 * If traced process is already stopped, 2297 * then no further action is necessary. 2298 */ 2299 if (p->p_flag & P_TRACED) 2300 goto out; 2301 /* 2302 * Already stopped, don't need to stop again 2303 * (If we did the shell could get confused). 2304 * Just make sure the signal STOP bit set. 2305 */ 2306 p->p_flag |= P_STOPPED_SIG; 2307 sigqueue_delete(sigqueue, sig); 2308 goto out; 2309 } 2310 2311 /* 2312 * All other kinds of signals: 2313 * If a thread is sleeping interruptibly, simulate a 2314 * wakeup so that when it is continued it will be made 2315 * runnable and can look at the signal. However, don't make 2316 * the PROCESS runnable, leave it stopped. 2317 * It may run a bit until it hits a thread_suspend_check(). 2318 */ 2319 wakeup_swapper = 0; 2320 PROC_SLOCK(p); 2321 thread_lock(td); 2322 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2323 wakeup_swapper = sleepq_abort(td, intrval); 2324 thread_unlock(td); 2325 PROC_SUNLOCK(p); 2326 if (wakeup_swapper) 2327 kick_proc0(); 2328 goto out; 2329 /* 2330 * Mutexes are short lived. Threads waiting on them will 2331 * hit thread_suspend_check() soon. 2332 */ 2333 } else if (p->p_state == PRS_NORMAL) { 2334 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2335 tdsigwakeup(td, sig, action, intrval); 2336 goto out; 2337 } 2338 2339 MPASS(action == SIG_DFL); 2340 2341 if (prop & SIGPROP_STOP) { 2342 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2343 goto out; 2344 p->p_flag |= P_STOPPED_SIG; 2345 p->p_xsig = sig; 2346 PROC_SLOCK(p); 2347 wakeup_swapper = sig_suspend_threads(td, p, 1); 2348 if (p->p_numthreads == p->p_suspcount) { 2349 /* 2350 * only thread sending signal to another 2351 * process can reach here, if thread is sending 2352 * signal to its process, because thread does 2353 * not suspend itself here, p_numthreads 2354 * should never be equal to p_suspcount. 2355 */ 2356 thread_stopped(p); 2357 PROC_SUNLOCK(p); 2358 sigqueue_delete_proc(p, p->p_xsig); 2359 } else 2360 PROC_SUNLOCK(p); 2361 if (wakeup_swapper) 2362 kick_proc0(); 2363 goto out; 2364 } 2365 } else { 2366 /* Not in "NORMAL" state. discard the signal. */ 2367 sigqueue_delete(sigqueue, sig); 2368 goto out; 2369 } 2370 2371 /* 2372 * The process is not stopped so we need to apply the signal to all the 2373 * running threads. 2374 */ 2375 runfast: 2376 tdsigwakeup(td, sig, action, intrval); 2377 PROC_SLOCK(p); 2378 thread_unsuspend(p); 2379 PROC_SUNLOCK(p); 2380 out: 2381 /* If we jump here, proc slock should not be owned. */ 2382 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2383 return (ret); 2384 } 2385 2386 /* 2387 * The force of a signal has been directed against a single 2388 * thread. We need to see what we can do about knocking it 2389 * out of any sleep it may be in etc. 2390 */ 2391 static void 2392 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2393 { 2394 struct proc *p = td->td_proc; 2395 int prop; 2396 int wakeup_swapper; 2397 2398 wakeup_swapper = 0; 2399 PROC_LOCK_ASSERT(p, MA_OWNED); 2400 prop = sigprop(sig); 2401 2402 PROC_SLOCK(p); 2403 thread_lock(td); 2404 /* 2405 * Bring the priority of a thread up if we want it to get 2406 * killed in this lifetime. Be careful to avoid bumping the 2407 * priority of the idle thread, since we still allow to signal 2408 * kernel processes. 2409 */ 2410 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2411 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2412 sched_prio(td, PUSER); 2413 if (TD_ON_SLEEPQ(td)) { 2414 /* 2415 * If thread is sleeping uninterruptibly 2416 * we can't interrupt the sleep... the signal will 2417 * be noticed when the process returns through 2418 * trap() or syscall(). 2419 */ 2420 if ((td->td_flags & TDF_SINTR) == 0) 2421 goto out; 2422 /* 2423 * If SIGCONT is default (or ignored) and process is 2424 * asleep, we are finished; the process should not 2425 * be awakened. 2426 */ 2427 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2428 thread_unlock(td); 2429 PROC_SUNLOCK(p); 2430 sigqueue_delete(&p->p_sigqueue, sig); 2431 /* 2432 * It may be on either list in this state. 2433 * Remove from both for now. 2434 */ 2435 sigqueue_delete(&td->td_sigqueue, sig); 2436 return; 2437 } 2438 2439 /* 2440 * Don't awaken a sleeping thread for SIGSTOP if the 2441 * STOP signal is deferred. 2442 */ 2443 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2444 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2445 goto out; 2446 2447 /* 2448 * Give low priority threads a better chance to run. 2449 */ 2450 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2451 sched_prio(td, PUSER); 2452 2453 wakeup_swapper = sleepq_abort(td, intrval); 2454 } else { 2455 /* 2456 * Other states do nothing with the signal immediately, 2457 * other than kicking ourselves if we are running. 2458 * It will either never be noticed, or noticed very soon. 2459 */ 2460 #ifdef SMP 2461 if (TD_IS_RUNNING(td) && td != curthread) 2462 forward_signal(td); 2463 #endif 2464 } 2465 out: 2466 PROC_SUNLOCK(p); 2467 thread_unlock(td); 2468 if (wakeup_swapper) 2469 kick_proc0(); 2470 } 2471 2472 static int 2473 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2474 { 2475 struct thread *td2; 2476 int wakeup_swapper; 2477 2478 PROC_LOCK_ASSERT(p, MA_OWNED); 2479 PROC_SLOCK_ASSERT(p, MA_OWNED); 2480 MPASS(sending || td == curthread); 2481 2482 wakeup_swapper = 0; 2483 FOREACH_THREAD_IN_PROC(p, td2) { 2484 thread_lock(td2); 2485 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2486 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2487 (td2->td_flags & TDF_SINTR)) { 2488 if (td2->td_flags & TDF_SBDRY) { 2489 /* 2490 * Once a thread is asleep with 2491 * TDF_SBDRY and without TDF_SERESTART 2492 * or TDF_SEINTR set, it should never 2493 * become suspended due to this check. 2494 */ 2495 KASSERT(!TD_IS_SUSPENDED(td2), 2496 ("thread with deferred stops suspended")); 2497 if (TD_SBDRY_INTR(td2)) 2498 wakeup_swapper |= sleepq_abort(td2, 2499 TD_SBDRY_ERRNO(td2)); 2500 } else if (!TD_IS_SUSPENDED(td2)) { 2501 thread_suspend_one(td2); 2502 } 2503 } else if (!TD_IS_SUSPENDED(td2)) { 2504 if (sending || td != td2) 2505 td2->td_flags |= TDF_ASTPENDING; 2506 #ifdef SMP 2507 if (TD_IS_RUNNING(td2) && td2 != td) 2508 forward_signal(td2); 2509 #endif 2510 } 2511 thread_unlock(td2); 2512 } 2513 return (wakeup_swapper); 2514 } 2515 2516 /* 2517 * Stop the process for an event deemed interesting to the debugger. If si is 2518 * non-NULL, this is a signal exchange; the new signal requested by the 2519 * debugger will be returned for handling. If si is NULL, this is some other 2520 * type of interesting event. The debugger may request a signal be delivered in 2521 * that case as well, however it will be deferred until it can be handled. 2522 */ 2523 int 2524 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2525 { 2526 struct proc *p = td->td_proc; 2527 struct thread *td2; 2528 ksiginfo_t ksi; 2529 int prop; 2530 2531 PROC_LOCK_ASSERT(p, MA_OWNED); 2532 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2533 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2534 &p->p_mtx.lock_object, "Stopping for traced signal"); 2535 2536 td->td_xsig = sig; 2537 2538 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2539 td->td_dbgflags |= TDB_XSIG; 2540 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2541 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2542 PROC_SLOCK(p); 2543 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2544 if (P_KILLED(p)) { 2545 /* 2546 * Ensure that, if we've been PT_KILLed, the 2547 * exit status reflects that. Another thread 2548 * may also be in ptracestop(), having just 2549 * received the SIGKILL, but this thread was 2550 * unsuspended first. 2551 */ 2552 td->td_dbgflags &= ~TDB_XSIG; 2553 td->td_xsig = SIGKILL; 2554 p->p_ptevents = 0; 2555 break; 2556 } 2557 if (p->p_flag & P_SINGLE_EXIT && 2558 !(td->td_dbgflags & TDB_EXIT)) { 2559 /* 2560 * Ignore ptrace stops except for thread exit 2561 * events when the process exits. 2562 */ 2563 td->td_dbgflags &= ~TDB_XSIG; 2564 PROC_SUNLOCK(p); 2565 return (0); 2566 } 2567 2568 /* 2569 * Make wait(2) work. Ensure that right after the 2570 * attach, the thread which was decided to become the 2571 * leader of attach gets reported to the waiter. 2572 * Otherwise, just avoid overwriting another thread's 2573 * assignment to p_xthread. If another thread has 2574 * already set p_xthread, the current thread will get 2575 * a chance to report itself upon the next iteration. 2576 */ 2577 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2578 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2579 p->p_xthread == NULL)) { 2580 p->p_xsig = sig; 2581 p->p_xthread = td; 2582 td->td_dbgflags &= ~TDB_FSTP; 2583 p->p_flag2 &= ~P2_PTRACE_FSTP; 2584 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2585 sig_suspend_threads(td, p, 0); 2586 } 2587 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2588 td->td_dbgflags &= ~TDB_STOPATFORK; 2589 cv_broadcast(&p->p_dbgwait); 2590 } 2591 stopme: 2592 thread_suspend_switch(td, p); 2593 if (p->p_xthread == td) 2594 p->p_xthread = NULL; 2595 if (!(p->p_flag & P_TRACED)) 2596 break; 2597 if (td->td_dbgflags & TDB_SUSPEND) { 2598 if (p->p_flag & P_SINGLE_EXIT) 2599 break; 2600 goto stopme; 2601 } 2602 } 2603 PROC_SUNLOCK(p); 2604 } 2605 2606 if (si != NULL && sig == td->td_xsig) { 2607 /* Parent wants us to take the original signal unchanged. */ 2608 si->ksi_flags |= KSI_HEAD; 2609 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2610 si->ksi_signo = 0; 2611 } else if (td->td_xsig != 0) { 2612 /* 2613 * If parent wants us to take a new signal, then it will leave 2614 * it in td->td_xsig; otherwise we just look for signals again. 2615 */ 2616 ksiginfo_init(&ksi); 2617 ksi.ksi_signo = td->td_xsig; 2618 ksi.ksi_flags |= KSI_PTRACE; 2619 prop = sigprop(td->td_xsig); 2620 td2 = sigtd(p, td->td_xsig, prop); 2621 tdsendsignal(p, td2, td->td_xsig, &ksi); 2622 if (td != td2) 2623 return (0); 2624 } 2625 2626 return (td->td_xsig); 2627 } 2628 2629 static void 2630 reschedule_signals(struct proc *p, sigset_t block, int flags) 2631 { 2632 struct sigacts *ps; 2633 struct thread *td; 2634 int sig; 2635 2636 PROC_LOCK_ASSERT(p, MA_OWNED); 2637 ps = p->p_sigacts; 2638 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2639 MA_OWNED : MA_NOTOWNED); 2640 if (SIGISEMPTY(p->p_siglist)) 2641 return; 2642 SIGSETAND(block, p->p_siglist); 2643 while ((sig = sig_ffs(&block)) != 0) { 2644 SIGDELSET(block, sig); 2645 td = sigtd(p, sig, 0); 2646 signotify(td); 2647 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2648 mtx_lock(&ps->ps_mtx); 2649 if (p->p_flag & P_TRACED || 2650 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2651 !SIGISMEMBER(td->td_sigmask, sig))) 2652 tdsigwakeup(td, sig, SIG_CATCH, 2653 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2654 ERESTART)); 2655 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2656 mtx_unlock(&ps->ps_mtx); 2657 } 2658 } 2659 2660 void 2661 tdsigcleanup(struct thread *td) 2662 { 2663 struct proc *p; 2664 sigset_t unblocked; 2665 2666 p = td->td_proc; 2667 PROC_LOCK_ASSERT(p, MA_OWNED); 2668 2669 sigqueue_flush(&td->td_sigqueue); 2670 if (p->p_numthreads == 1) 2671 return; 2672 2673 /* 2674 * Since we cannot handle signals, notify signal post code 2675 * about this by filling the sigmask. 2676 * 2677 * Also, if needed, wake up thread(s) that do not block the 2678 * same signals as the exiting thread, since the thread might 2679 * have been selected for delivery and woken up. 2680 */ 2681 SIGFILLSET(unblocked); 2682 SIGSETNAND(unblocked, td->td_sigmask); 2683 SIGFILLSET(td->td_sigmask); 2684 reschedule_signals(p, unblocked, 0); 2685 2686 } 2687 2688 static int 2689 sigdeferstop_curr_flags(int cflags) 2690 { 2691 2692 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2693 (cflags & TDF_SBDRY) != 0); 2694 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2695 } 2696 2697 /* 2698 * Defer the delivery of SIGSTOP for the current thread, according to 2699 * the requested mode. Returns previous flags, which must be restored 2700 * by sigallowstop(). 2701 * 2702 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2703 * cleared by the current thread, which allow the lock-less read-only 2704 * accesses below. 2705 */ 2706 int 2707 sigdeferstop_impl(int mode) 2708 { 2709 struct thread *td; 2710 int cflags, nflags; 2711 2712 td = curthread; 2713 cflags = sigdeferstop_curr_flags(td->td_flags); 2714 switch (mode) { 2715 case SIGDEFERSTOP_NOP: 2716 nflags = cflags; 2717 break; 2718 case SIGDEFERSTOP_OFF: 2719 nflags = 0; 2720 break; 2721 case SIGDEFERSTOP_SILENT: 2722 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2723 break; 2724 case SIGDEFERSTOP_EINTR: 2725 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2726 break; 2727 case SIGDEFERSTOP_ERESTART: 2728 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2729 break; 2730 default: 2731 panic("sigdeferstop: invalid mode %x", mode); 2732 break; 2733 } 2734 if (cflags == nflags) 2735 return (SIGDEFERSTOP_VAL_NCHG); 2736 thread_lock(td); 2737 td->td_flags = (td->td_flags & ~cflags) | nflags; 2738 thread_unlock(td); 2739 return (cflags); 2740 } 2741 2742 /* 2743 * Restores the STOP handling mode, typically permitting the delivery 2744 * of SIGSTOP for the current thread. This does not immediately 2745 * suspend if a stop was posted. Instead, the thread will suspend 2746 * either via ast() or a subsequent interruptible sleep. 2747 */ 2748 void 2749 sigallowstop_impl(int prev) 2750 { 2751 struct thread *td; 2752 int cflags; 2753 2754 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2755 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2756 ("sigallowstop: incorrect previous mode %x", prev)); 2757 td = curthread; 2758 cflags = sigdeferstop_curr_flags(td->td_flags); 2759 if (cflags != prev) { 2760 thread_lock(td); 2761 td->td_flags = (td->td_flags & ~cflags) | prev; 2762 thread_unlock(td); 2763 } 2764 } 2765 2766 /* 2767 * If the current process has received a signal (should be caught or cause 2768 * termination, should interrupt current syscall), return the signal number. 2769 * Stop signals with default action are processed immediately, then cleared; 2770 * they aren't returned. This is checked after each entry to the system for 2771 * a syscall or trap (though this can usually be done without calling issignal 2772 * by checking the pending signal masks in cursig.) The normal call 2773 * sequence is 2774 * 2775 * while (sig = cursig(curthread)) 2776 * postsig(sig); 2777 */ 2778 static int 2779 issignal(struct thread *td) 2780 { 2781 struct proc *p; 2782 struct sigacts *ps; 2783 struct sigqueue *queue; 2784 sigset_t sigpending; 2785 ksiginfo_t ksi; 2786 int prop, sig, traced; 2787 2788 p = td->td_proc; 2789 ps = p->p_sigacts; 2790 mtx_assert(&ps->ps_mtx, MA_OWNED); 2791 PROC_LOCK_ASSERT(p, MA_OWNED); 2792 for (;;) { 2793 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2794 2795 sigpending = td->td_sigqueue.sq_signals; 2796 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2797 SIGSETNAND(sigpending, td->td_sigmask); 2798 2799 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2800 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2801 SIG_STOPSIGMASK(sigpending); 2802 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2803 return (0); 2804 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2805 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2806 SIGISMEMBER(sigpending, SIGSTOP)) { 2807 /* 2808 * If debugger just attached, always consume 2809 * SIGSTOP from ptrace(PT_ATTACH) first, to 2810 * execute the debugger attach ritual in 2811 * order. 2812 */ 2813 sig = SIGSTOP; 2814 td->td_dbgflags |= TDB_FSTP; 2815 } else { 2816 sig = sig_ffs(&sigpending); 2817 } 2818 2819 if (p->p_stops & S_SIG) { 2820 mtx_unlock(&ps->ps_mtx); 2821 stopevent(p, S_SIG, sig); 2822 mtx_lock(&ps->ps_mtx); 2823 } 2824 2825 /* 2826 * We should see pending but ignored signals 2827 * only if P_TRACED was on when they were posted. 2828 */ 2829 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2830 sigqueue_delete(&td->td_sigqueue, sig); 2831 sigqueue_delete(&p->p_sigqueue, sig); 2832 continue; 2833 } 2834 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2835 /* 2836 * If traced, always stop. 2837 * Remove old signal from queue before the stop. 2838 * XXX shrug off debugger, it causes siginfo to 2839 * be thrown away. 2840 */ 2841 queue = &td->td_sigqueue; 2842 ksiginfo_init(&ksi); 2843 if (sigqueue_get(queue, sig, &ksi) == 0) { 2844 queue = &p->p_sigqueue; 2845 sigqueue_get(queue, sig, &ksi); 2846 } 2847 td->td_si = ksi.ksi_info; 2848 2849 mtx_unlock(&ps->ps_mtx); 2850 sig = ptracestop(td, sig, &ksi); 2851 mtx_lock(&ps->ps_mtx); 2852 2853 /* 2854 * Keep looking if the debugger discarded or 2855 * replaced the signal. 2856 */ 2857 if (sig == 0) 2858 continue; 2859 2860 /* 2861 * If the signal became masked, re-queue it. 2862 */ 2863 if (SIGISMEMBER(td->td_sigmask, sig)) { 2864 ksi.ksi_flags |= KSI_HEAD; 2865 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2866 continue; 2867 } 2868 2869 /* 2870 * If the traced bit got turned off, requeue 2871 * the signal and go back up to the top to 2872 * rescan signals. This ensures that p_sig* 2873 * and p_sigact are consistent. 2874 */ 2875 if ((p->p_flag & P_TRACED) == 0) { 2876 ksi.ksi_flags |= KSI_HEAD; 2877 sigqueue_add(queue, sig, &ksi); 2878 continue; 2879 } 2880 } 2881 2882 prop = sigprop(sig); 2883 2884 /* 2885 * Decide whether the signal should be returned. 2886 * Return the signal's number, or fall through 2887 * to clear it from the pending mask. 2888 */ 2889 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2890 2891 case (intptr_t)SIG_DFL: 2892 /* 2893 * Don't take default actions on system processes. 2894 */ 2895 if (p->p_pid <= 1) { 2896 #ifdef DIAGNOSTIC 2897 /* 2898 * Are you sure you want to ignore SIGSEGV 2899 * in init? XXX 2900 */ 2901 printf("Process (pid %lu) got signal %d\n", 2902 (u_long)p->p_pid, sig); 2903 #endif 2904 break; /* == ignore */ 2905 } 2906 /* 2907 * If there is a pending stop signal to process with 2908 * default action, stop here, then clear the signal. 2909 * Traced or exiting processes should ignore stops. 2910 * Additionally, a member of an orphaned process group 2911 * should ignore tty stops. 2912 */ 2913 if (prop & SIGPROP_STOP) { 2914 if (p->p_flag & 2915 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2916 (p->p_pgrp->pg_jobc == 0 && 2917 prop & SIGPROP_TTYSTOP)) 2918 break; /* == ignore */ 2919 if (TD_SBDRY_INTR(td)) { 2920 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2921 ("lost TDF_SBDRY")); 2922 return (-1); 2923 } 2924 mtx_unlock(&ps->ps_mtx); 2925 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2926 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2927 sigqueue_delete(&td->td_sigqueue, sig); 2928 sigqueue_delete(&p->p_sigqueue, sig); 2929 p->p_flag |= P_STOPPED_SIG; 2930 p->p_xsig = sig; 2931 PROC_SLOCK(p); 2932 sig_suspend_threads(td, p, 0); 2933 thread_suspend_switch(td, p); 2934 PROC_SUNLOCK(p); 2935 mtx_lock(&ps->ps_mtx); 2936 goto next; 2937 } else if (prop & SIGPROP_IGNORE) { 2938 /* 2939 * Except for SIGCONT, shouldn't get here. 2940 * Default action is to ignore; drop it. 2941 */ 2942 break; /* == ignore */ 2943 } else 2944 return (sig); 2945 /*NOTREACHED*/ 2946 2947 case (intptr_t)SIG_IGN: 2948 /* 2949 * Masking above should prevent us ever trying 2950 * to take action on an ignored signal other 2951 * than SIGCONT, unless process is traced. 2952 */ 2953 if ((prop & SIGPROP_CONT) == 0 && 2954 (p->p_flag & P_TRACED) == 0) 2955 printf("issignal\n"); 2956 break; /* == ignore */ 2957 2958 default: 2959 /* 2960 * This signal has an action, let 2961 * postsig() process it. 2962 */ 2963 return (sig); 2964 } 2965 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2966 sigqueue_delete(&p->p_sigqueue, sig); 2967 next:; 2968 } 2969 /* NOTREACHED */ 2970 } 2971 2972 void 2973 thread_stopped(struct proc *p) 2974 { 2975 int n; 2976 2977 PROC_LOCK_ASSERT(p, MA_OWNED); 2978 PROC_SLOCK_ASSERT(p, MA_OWNED); 2979 n = p->p_suspcount; 2980 if (p == curproc) 2981 n++; 2982 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2983 PROC_SUNLOCK(p); 2984 p->p_flag &= ~P_WAITED; 2985 PROC_LOCK(p->p_pptr); 2986 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2987 CLD_TRAPPED : CLD_STOPPED); 2988 PROC_UNLOCK(p->p_pptr); 2989 PROC_SLOCK(p); 2990 } 2991 } 2992 2993 /* 2994 * Take the action for the specified signal 2995 * from the current set of pending signals. 2996 */ 2997 int 2998 postsig(int sig) 2999 { 3000 struct thread *td; 3001 struct proc *p; 3002 struct sigacts *ps; 3003 sig_t action; 3004 ksiginfo_t ksi; 3005 sigset_t returnmask; 3006 3007 KASSERT(sig != 0, ("postsig")); 3008 3009 td = curthread; 3010 p = td->td_proc; 3011 PROC_LOCK_ASSERT(p, MA_OWNED); 3012 ps = p->p_sigacts; 3013 mtx_assert(&ps->ps_mtx, MA_OWNED); 3014 ksiginfo_init(&ksi); 3015 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3016 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3017 return (0); 3018 ksi.ksi_signo = sig; 3019 if (ksi.ksi_code == SI_TIMER) 3020 itimer_accept(p, ksi.ksi_timerid, &ksi); 3021 action = ps->ps_sigact[_SIG_IDX(sig)]; 3022 #ifdef KTRACE 3023 if (KTRPOINT(td, KTR_PSIG)) 3024 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3025 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3026 #endif 3027 if ((p->p_stops & S_SIG) != 0) { 3028 mtx_unlock(&ps->ps_mtx); 3029 stopevent(p, S_SIG, sig); 3030 mtx_lock(&ps->ps_mtx); 3031 } 3032 3033 if (action == SIG_DFL) { 3034 /* 3035 * Default action, where the default is to kill 3036 * the process. (Other cases were ignored above.) 3037 */ 3038 mtx_unlock(&ps->ps_mtx); 3039 proc_td_siginfo_capture(td, &ksi.ksi_info); 3040 sigexit(td, sig); 3041 /* NOTREACHED */ 3042 } else { 3043 /* 3044 * If we get here, the signal must be caught. 3045 */ 3046 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3047 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3048 ("postsig action: blocked sig %d", sig)); 3049 3050 /* 3051 * Set the new mask value and also defer further 3052 * occurrences of this signal. 3053 * 3054 * Special case: user has done a sigsuspend. Here the 3055 * current mask is not of interest, but rather the 3056 * mask from before the sigsuspend is what we want 3057 * restored after the signal processing is completed. 3058 */ 3059 if (td->td_pflags & TDP_OLDMASK) { 3060 returnmask = td->td_oldsigmask; 3061 td->td_pflags &= ~TDP_OLDMASK; 3062 } else 3063 returnmask = td->td_sigmask; 3064 3065 if (p->p_sig == sig) { 3066 p->p_code = 0; 3067 p->p_sig = 0; 3068 } 3069 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3070 postsig_done(sig, td, ps); 3071 } 3072 return (1); 3073 } 3074 3075 /* 3076 * Kill the current process for stated reason. 3077 */ 3078 void 3079 killproc(struct proc *p, char *why) 3080 { 3081 3082 PROC_LOCK_ASSERT(p, MA_OWNED); 3083 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3084 p->p_comm); 3085 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3086 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3087 p->p_flag |= P_WKILLED; 3088 kern_psignal(p, SIGKILL); 3089 } 3090 3091 /* 3092 * Force the current process to exit with the specified signal, dumping core 3093 * if appropriate. We bypass the normal tests for masked and caught signals, 3094 * allowing unrecoverable failures to terminate the process without changing 3095 * signal state. Mark the accounting record with the signal termination. 3096 * If dumping core, save the signal number for the debugger. Calls exit and 3097 * does not return. 3098 */ 3099 void 3100 sigexit(struct thread *td, int sig) 3101 { 3102 struct proc *p = td->td_proc; 3103 3104 PROC_LOCK_ASSERT(p, MA_OWNED); 3105 p->p_acflag |= AXSIG; 3106 /* 3107 * We must be single-threading to generate a core dump. This 3108 * ensures that the registers in the core file are up-to-date. 3109 * Also, the ELF dump handler assumes that the thread list doesn't 3110 * change out from under it. 3111 * 3112 * XXX If another thread attempts to single-thread before us 3113 * (e.g. via fork()), we won't get a dump at all. 3114 */ 3115 if ((sigprop(sig) & SIGPROP_CORE) && 3116 thread_single(p, SINGLE_NO_EXIT) == 0) { 3117 p->p_sig = sig; 3118 /* 3119 * Log signals which would cause core dumps 3120 * (Log as LOG_INFO to appease those who don't want 3121 * these messages.) 3122 * XXX : Todo, as well as euid, write out ruid too 3123 * Note that coredump() drops proc lock. 3124 */ 3125 if (coredump(td) == 0) 3126 sig |= WCOREFLAG; 3127 if (kern_logsigexit) 3128 log(LOG_INFO, 3129 "pid %d (%s), uid %d: exited on signal %d%s\n", 3130 p->p_pid, p->p_comm, 3131 td->td_ucred ? td->td_ucred->cr_uid : -1, 3132 sig &~ WCOREFLAG, 3133 sig & WCOREFLAG ? " (core dumped)" : ""); 3134 } else 3135 PROC_UNLOCK(p); 3136 exit1(td, 0, sig); 3137 /* NOTREACHED */ 3138 } 3139 3140 /* 3141 * Send queued SIGCHLD to parent when child process's state 3142 * is changed. 3143 */ 3144 static void 3145 sigparent(struct proc *p, int reason, int status) 3146 { 3147 PROC_LOCK_ASSERT(p, MA_OWNED); 3148 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3149 3150 if (p->p_ksi != NULL) { 3151 p->p_ksi->ksi_signo = SIGCHLD; 3152 p->p_ksi->ksi_code = reason; 3153 p->p_ksi->ksi_status = status; 3154 p->p_ksi->ksi_pid = p->p_pid; 3155 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3156 if (KSI_ONQ(p->p_ksi)) 3157 return; 3158 } 3159 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3160 } 3161 3162 static void 3163 childproc_jobstate(struct proc *p, int reason, int sig) 3164 { 3165 struct sigacts *ps; 3166 3167 PROC_LOCK_ASSERT(p, MA_OWNED); 3168 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3169 3170 /* 3171 * Wake up parent sleeping in kern_wait(), also send 3172 * SIGCHLD to parent, but SIGCHLD does not guarantee 3173 * that parent will awake, because parent may masked 3174 * the signal. 3175 */ 3176 p->p_pptr->p_flag |= P_STATCHILD; 3177 wakeup(p->p_pptr); 3178 3179 ps = p->p_pptr->p_sigacts; 3180 mtx_lock(&ps->ps_mtx); 3181 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3182 mtx_unlock(&ps->ps_mtx); 3183 sigparent(p, reason, sig); 3184 } else 3185 mtx_unlock(&ps->ps_mtx); 3186 } 3187 3188 void 3189 childproc_stopped(struct proc *p, int reason) 3190 { 3191 3192 childproc_jobstate(p, reason, p->p_xsig); 3193 } 3194 3195 void 3196 childproc_continued(struct proc *p) 3197 { 3198 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3199 } 3200 3201 void 3202 childproc_exited(struct proc *p) 3203 { 3204 int reason, status; 3205 3206 if (WCOREDUMP(p->p_xsig)) { 3207 reason = CLD_DUMPED; 3208 status = WTERMSIG(p->p_xsig); 3209 } else if (WIFSIGNALED(p->p_xsig)) { 3210 reason = CLD_KILLED; 3211 status = WTERMSIG(p->p_xsig); 3212 } else { 3213 reason = CLD_EXITED; 3214 status = p->p_xexit; 3215 } 3216 /* 3217 * XXX avoid calling wakeup(p->p_pptr), the work is 3218 * done in exit1(). 3219 */ 3220 sigparent(p, reason, status); 3221 } 3222 3223 /* 3224 * We only have 1 character for the core count in the format 3225 * string, so the range will be 0-9 3226 */ 3227 #define MAX_NUM_CORE_FILES 10 3228 #ifndef NUM_CORE_FILES 3229 #define NUM_CORE_FILES 5 3230 #endif 3231 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3232 static int num_cores = NUM_CORE_FILES; 3233 3234 static int 3235 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3236 { 3237 int error; 3238 int new_val; 3239 3240 new_val = num_cores; 3241 error = sysctl_handle_int(oidp, &new_val, 0, req); 3242 if (error != 0 || req->newptr == NULL) 3243 return (error); 3244 if (new_val > MAX_NUM_CORE_FILES) 3245 new_val = MAX_NUM_CORE_FILES; 3246 if (new_val < 0) 3247 new_val = 0; 3248 num_cores = new_val; 3249 return (0); 3250 } 3251 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3252 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3253 3254 #define GZIP_SUFFIX ".gz" 3255 #define ZSTD_SUFFIX ".zst" 3256 3257 int compress_user_cores = 0; 3258 3259 static int 3260 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3261 { 3262 int error, val; 3263 3264 val = compress_user_cores; 3265 error = sysctl_handle_int(oidp, &val, 0, req); 3266 if (error != 0 || req->newptr == NULL) 3267 return (error); 3268 if (val != 0 && !compressor_avail(val)) 3269 return (EINVAL); 3270 compress_user_cores = val; 3271 return (error); 3272 } 3273 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3274 0, sizeof(int), sysctl_compress_user_cores, "I", 3275 "Enable compression of user corefiles (" 3276 __XSTRING(COMPRESS_GZIP) " = gzip, " 3277 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3278 3279 int compress_user_cores_level = 6; 3280 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3281 &compress_user_cores_level, 0, 3282 "Corefile compression level"); 3283 3284 /* 3285 * Protect the access to corefilename[] by allproc_lock. 3286 */ 3287 #define corefilename_lock allproc_lock 3288 3289 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3290 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3291 3292 static int 3293 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3294 { 3295 int error; 3296 3297 sx_xlock(&corefilename_lock); 3298 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3299 req); 3300 sx_xunlock(&corefilename_lock); 3301 3302 return (error); 3303 } 3304 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3305 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3306 "Process corefile name format string"); 3307 3308 /* 3309 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3310 * Expand the name described in corefilename, using name, uid, and pid 3311 * and open/create core file. 3312 * corefilename is a printf-like string, with three format specifiers: 3313 * %N name of process ("name") 3314 * %P process id (pid) 3315 * %U user id (uid) 3316 * For example, "%N.core" is the default; they can be disabled completely 3317 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3318 * This is controlled by the sysctl variable kern.corefile (see above). 3319 */ 3320 static int 3321 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3322 int compress, struct vnode **vpp, char **namep) 3323 { 3324 struct nameidata nd; 3325 struct sbuf sb; 3326 const char *format; 3327 char *hostname, *name; 3328 int indexpos, i, error, cmode, flags, oflags; 3329 3330 hostname = NULL; 3331 format = corefilename; 3332 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3333 indexpos = -1; 3334 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3335 sx_slock(&corefilename_lock); 3336 for (i = 0; format[i] != '\0'; i++) { 3337 switch (format[i]) { 3338 case '%': /* Format character */ 3339 i++; 3340 switch (format[i]) { 3341 case '%': 3342 sbuf_putc(&sb, '%'); 3343 break; 3344 case 'H': /* hostname */ 3345 if (hostname == NULL) { 3346 hostname = malloc(MAXHOSTNAMELEN, 3347 M_TEMP, M_WAITOK); 3348 } 3349 getcredhostname(td->td_ucred, hostname, 3350 MAXHOSTNAMELEN); 3351 sbuf_printf(&sb, "%s", hostname); 3352 break; 3353 case 'I': /* autoincrementing index */ 3354 sbuf_printf(&sb, "0"); 3355 indexpos = sbuf_len(&sb) - 1; 3356 break; 3357 case 'N': /* process name */ 3358 sbuf_printf(&sb, "%s", comm); 3359 break; 3360 case 'P': /* process id */ 3361 sbuf_printf(&sb, "%u", pid); 3362 break; 3363 case 'U': /* user id */ 3364 sbuf_printf(&sb, "%u", uid); 3365 break; 3366 default: 3367 log(LOG_ERR, 3368 "Unknown format character %c in " 3369 "corename `%s'\n", format[i], format); 3370 break; 3371 } 3372 break; 3373 default: 3374 sbuf_putc(&sb, format[i]); 3375 break; 3376 } 3377 } 3378 sx_sunlock(&corefilename_lock); 3379 free(hostname, M_TEMP); 3380 if (compress == COMPRESS_GZIP) 3381 sbuf_printf(&sb, GZIP_SUFFIX); 3382 else if (compress == COMPRESS_ZSTD) 3383 sbuf_printf(&sb, ZSTD_SUFFIX); 3384 if (sbuf_error(&sb) != 0) { 3385 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3386 "long\n", (long)pid, comm, (u_long)uid); 3387 sbuf_delete(&sb); 3388 free(name, M_TEMP); 3389 return (ENOMEM); 3390 } 3391 sbuf_finish(&sb); 3392 sbuf_delete(&sb); 3393 3394 cmode = S_IRUSR | S_IWUSR; 3395 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3396 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3397 3398 /* 3399 * If the core format has a %I in it, then we need to check 3400 * for existing corefiles before returning a name. 3401 * To do this we iterate over 0..num_cores to find a 3402 * non-existing core file name to use. 3403 */ 3404 if (indexpos != -1) { 3405 for (i = 0; i < num_cores; i++) { 3406 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3407 name[indexpos] = '0' + i; 3408 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3409 error = vn_open_cred(&nd, &flags, cmode, oflags, 3410 td->td_ucred, NULL); 3411 if (error) { 3412 if (error == EEXIST) 3413 continue; 3414 log(LOG_ERR, 3415 "pid %d (%s), uid (%u): Path `%s' failed " 3416 "on initial open test, error = %d\n", 3417 pid, comm, uid, name, error); 3418 } 3419 goto out; 3420 } 3421 } 3422 3423 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3424 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3425 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3426 out: 3427 if (error) { 3428 #ifdef AUDIT 3429 audit_proc_coredump(td, name, error); 3430 #endif 3431 free(name, M_TEMP); 3432 return (error); 3433 } 3434 NDFREE(&nd, NDF_ONLY_PNBUF); 3435 *vpp = nd.ni_vp; 3436 *namep = name; 3437 return (0); 3438 } 3439 3440 static int 3441 coredump_sanitise_path(const char *path) 3442 { 3443 size_t i; 3444 3445 /* 3446 * Only send a subset of ASCII to devd(8) because it 3447 * might pass these strings to sh -c. 3448 */ 3449 for (i = 0; path[i]; i++) 3450 if (!(isalpha(path[i]) || isdigit(path[i])) && 3451 path[i] != '/' && path[i] != '.' && 3452 path[i] != '-') 3453 return (0); 3454 3455 return (1); 3456 } 3457 3458 /* 3459 * Dump a process' core. The main routine does some 3460 * policy checking, and creates the name of the coredump; 3461 * then it passes on a vnode and a size limit to the process-specific 3462 * coredump routine if there is one; if there _is not_ one, it returns 3463 * ENOSYS; otherwise it returns the error from the process-specific routine. 3464 */ 3465 3466 static int 3467 coredump(struct thread *td) 3468 { 3469 struct proc *p = td->td_proc; 3470 struct ucred *cred = td->td_ucred; 3471 struct vnode *vp; 3472 struct flock lf; 3473 struct vattr vattr; 3474 int error, error1, locked; 3475 char *name; /* name of corefile */ 3476 void *rl_cookie; 3477 off_t limit; 3478 char *data = NULL; 3479 char *fullpath, *freepath = NULL; 3480 size_t len; 3481 static const char comm_name[] = "comm="; 3482 static const char core_name[] = "core="; 3483 3484 PROC_LOCK_ASSERT(p, MA_OWNED); 3485 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3486 _STOPEVENT(p, S_CORE, 0); 3487 3488 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3489 (p->p_flag2 & P2_NOTRACE) != 0) { 3490 PROC_UNLOCK(p); 3491 return (EFAULT); 3492 } 3493 3494 /* 3495 * Note that the bulk of limit checking is done after 3496 * the corefile is created. The exception is if the limit 3497 * for corefiles is 0, in which case we don't bother 3498 * creating the corefile at all. This layout means that 3499 * a corefile is truncated instead of not being created, 3500 * if it is larger than the limit. 3501 */ 3502 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3503 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3504 PROC_UNLOCK(p); 3505 return (EFBIG); 3506 } 3507 PROC_UNLOCK(p); 3508 3509 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3510 compress_user_cores, &vp, &name); 3511 if (error != 0) 3512 return (error); 3513 3514 /* 3515 * Don't dump to non-regular files or files with links. 3516 * Do not dump into system files. 3517 */ 3518 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3519 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3520 VOP_UNLOCK(vp, 0); 3521 error = EFAULT; 3522 goto out; 3523 } 3524 3525 VOP_UNLOCK(vp, 0); 3526 3527 /* Postpone other writers, including core dumps of other processes. */ 3528 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3529 3530 lf.l_whence = SEEK_SET; 3531 lf.l_start = 0; 3532 lf.l_len = 0; 3533 lf.l_type = F_WRLCK; 3534 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3535 3536 VATTR_NULL(&vattr); 3537 vattr.va_size = 0; 3538 if (set_core_nodump_flag) 3539 vattr.va_flags = UF_NODUMP; 3540 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3541 VOP_SETATTR(vp, &vattr, cred); 3542 VOP_UNLOCK(vp, 0); 3543 PROC_LOCK(p); 3544 p->p_acflag |= ACORE; 3545 PROC_UNLOCK(p); 3546 3547 if (p->p_sysent->sv_coredump != NULL) { 3548 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3549 } else { 3550 error = ENOSYS; 3551 } 3552 3553 if (locked) { 3554 lf.l_type = F_UNLCK; 3555 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3556 } 3557 vn_rangelock_unlock(vp, rl_cookie); 3558 3559 /* 3560 * Notify the userland helper that a process triggered a core dump. 3561 * This allows the helper to run an automated debugging session. 3562 */ 3563 if (error != 0 || coredump_devctl == 0) 3564 goto out; 3565 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3566 sizeof(' ') + sizeof(core_name) - 1; 3567 data = malloc(len, M_TEMP, M_WAITOK); 3568 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3569 goto out; 3570 if (!coredump_sanitise_path(fullpath)) 3571 goto out; 3572 snprintf(data, len, "%s%s ", comm_name, fullpath); 3573 free(freepath, M_TEMP); 3574 freepath = NULL; 3575 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3576 goto out; 3577 if (!coredump_sanitise_path(fullpath)) 3578 goto out; 3579 strlcat(data, core_name, len); 3580 strlcat(data, fullpath, len); 3581 devctl_notify("kernel", "signal", "coredump", data); 3582 out: 3583 error1 = vn_close(vp, FWRITE, cred, td); 3584 if (error == 0) 3585 error = error1; 3586 #ifdef AUDIT 3587 audit_proc_coredump(td, name, error); 3588 #endif 3589 free(freepath, M_TEMP); 3590 free(data, M_TEMP); 3591 free(name, M_TEMP); 3592 return (error); 3593 } 3594 3595 /* 3596 * Nonexistent system call-- signal process (may want to handle it). Flag 3597 * error in case process won't see signal immediately (blocked or ignored). 3598 */ 3599 #ifndef _SYS_SYSPROTO_H_ 3600 struct nosys_args { 3601 int dummy; 3602 }; 3603 #endif 3604 /* ARGSUSED */ 3605 int 3606 nosys(struct thread *td, struct nosys_args *args) 3607 { 3608 struct proc *p; 3609 3610 p = td->td_proc; 3611 3612 PROC_LOCK(p); 3613 tdsignal(td, SIGSYS); 3614 PROC_UNLOCK(p); 3615 if (kern_lognosys == 1 || kern_lognosys == 3) { 3616 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3617 td->td_sa.code); 3618 } 3619 if (kern_lognosys == 2 || kern_lognosys == 3) { 3620 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3621 td->td_sa.code); 3622 } 3623 return (ENOSYS); 3624 } 3625 3626 /* 3627 * Send a SIGIO or SIGURG signal to a process or process group using stored 3628 * credentials rather than those of the current process. 3629 */ 3630 void 3631 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3632 { 3633 ksiginfo_t ksi; 3634 struct sigio *sigio; 3635 3636 ksiginfo_init(&ksi); 3637 ksi.ksi_signo = sig; 3638 ksi.ksi_code = SI_KERNEL; 3639 3640 SIGIO_LOCK(); 3641 sigio = *sigiop; 3642 if (sigio == NULL) { 3643 SIGIO_UNLOCK(); 3644 return; 3645 } 3646 if (sigio->sio_pgid > 0) { 3647 PROC_LOCK(sigio->sio_proc); 3648 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3649 kern_psignal(sigio->sio_proc, sig); 3650 PROC_UNLOCK(sigio->sio_proc); 3651 } else if (sigio->sio_pgid < 0) { 3652 struct proc *p; 3653 3654 PGRP_LOCK(sigio->sio_pgrp); 3655 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3656 PROC_LOCK(p); 3657 if (p->p_state == PRS_NORMAL && 3658 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3659 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3660 kern_psignal(p, sig); 3661 PROC_UNLOCK(p); 3662 } 3663 PGRP_UNLOCK(sigio->sio_pgrp); 3664 } 3665 SIGIO_UNLOCK(); 3666 } 3667 3668 static int 3669 filt_sigattach(struct knote *kn) 3670 { 3671 struct proc *p = curproc; 3672 3673 kn->kn_ptr.p_proc = p; 3674 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3675 3676 knlist_add(p->p_klist, kn, 0); 3677 3678 return (0); 3679 } 3680 3681 static void 3682 filt_sigdetach(struct knote *kn) 3683 { 3684 struct proc *p = kn->kn_ptr.p_proc; 3685 3686 knlist_remove(p->p_klist, kn, 0); 3687 } 3688 3689 /* 3690 * signal knotes are shared with proc knotes, so we apply a mask to 3691 * the hint in order to differentiate them from process hints. This 3692 * could be avoided by using a signal-specific knote list, but probably 3693 * isn't worth the trouble. 3694 */ 3695 static int 3696 filt_signal(struct knote *kn, long hint) 3697 { 3698 3699 if (hint & NOTE_SIGNAL) { 3700 hint &= ~NOTE_SIGNAL; 3701 3702 if (kn->kn_id == hint) 3703 kn->kn_data++; 3704 } 3705 return (kn->kn_data != 0); 3706 } 3707 3708 struct sigacts * 3709 sigacts_alloc(void) 3710 { 3711 struct sigacts *ps; 3712 3713 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3714 refcount_init(&ps->ps_refcnt, 1); 3715 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3716 return (ps); 3717 } 3718 3719 void 3720 sigacts_free(struct sigacts *ps) 3721 { 3722 3723 if (refcount_release(&ps->ps_refcnt) == 0) 3724 return; 3725 mtx_destroy(&ps->ps_mtx); 3726 free(ps, M_SUBPROC); 3727 } 3728 3729 struct sigacts * 3730 sigacts_hold(struct sigacts *ps) 3731 { 3732 3733 refcount_acquire(&ps->ps_refcnt); 3734 return (ps); 3735 } 3736 3737 void 3738 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3739 { 3740 3741 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3742 mtx_lock(&src->ps_mtx); 3743 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3744 mtx_unlock(&src->ps_mtx); 3745 } 3746 3747 int 3748 sigacts_shared(struct sigacts *ps) 3749 { 3750 3751 return (ps->ps_refcnt > 1); 3752 } 3753