Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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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: releng/12.0/sys/kern/kern_sig.c 337330 2018-08-04 20:45:43Z kib $"); 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 { 608 609 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 610 611 if (SIGPENDING(td)) { 612 thread_lock(td); 613 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 614 thread_unlock(td); 615 } 616 } 617 618 int 619 sigonstack(size_t sp) 620 { 621 struct thread *td = curthread; 622 623 return ((td->td_pflags & TDP_ALTSTACK) ? 624 #if defined(COMPAT_43) 625 ((td->td_sigstk.ss_size == 0) ? 626 (td->td_sigstk.ss_flags & SS_ONSTACK) : 627 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 628 #else 629 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 630 #endif 631 : 0); 632 } 633 634 static __inline int 635 sigprop(int sig) 636 { 637 638 if (sig > 0 && sig < nitems(sigproptbl)) 639 return (sigproptbl[sig]); 640 return (0); 641 } 642 643 int 644 sig_ffs(sigset_t *set) 645 { 646 int i; 647 648 for (i = 0; i < _SIG_WORDS; i++) 649 if (set->__bits[i]) 650 return (ffs(set->__bits[i]) + (i * 32)); 651 return (0); 652 } 653 654 static bool 655 sigact_flag_test(const struct sigaction *act, int flag) 656 { 657 658 /* 659 * SA_SIGINFO is reset when signal disposition is set to 660 * ignore or default. Other flags are kept according to user 661 * settings. 662 */ 663 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 664 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 665 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 666 } 667 668 /* 669 * kern_sigaction 670 * sigaction 671 * freebsd4_sigaction 672 * osigaction 673 */ 674 int 675 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 676 struct sigaction *oact, int flags) 677 { 678 struct sigacts *ps; 679 struct proc *p = td->td_proc; 680 681 if (!_SIG_VALID(sig)) 682 return (EINVAL); 683 if (act != NULL && act->sa_handler != SIG_DFL && 684 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 685 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 686 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 687 return (EINVAL); 688 689 PROC_LOCK(p); 690 ps = p->p_sigacts; 691 mtx_lock(&ps->ps_mtx); 692 if (oact) { 693 memset(oact, 0, sizeof(*oact)); 694 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 695 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 696 oact->sa_flags |= SA_ONSTACK; 697 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 698 oact->sa_flags |= SA_RESTART; 699 if (SIGISMEMBER(ps->ps_sigreset, sig)) 700 oact->sa_flags |= SA_RESETHAND; 701 if (SIGISMEMBER(ps->ps_signodefer, sig)) 702 oact->sa_flags |= SA_NODEFER; 703 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 704 oact->sa_flags |= SA_SIGINFO; 705 oact->sa_sigaction = 706 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 707 } else 708 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 709 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 710 oact->sa_flags |= SA_NOCLDSTOP; 711 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 712 oact->sa_flags |= SA_NOCLDWAIT; 713 } 714 if (act) { 715 if ((sig == SIGKILL || sig == SIGSTOP) && 716 act->sa_handler != SIG_DFL) { 717 mtx_unlock(&ps->ps_mtx); 718 PROC_UNLOCK(p); 719 return (EINVAL); 720 } 721 722 /* 723 * Change setting atomically. 724 */ 725 726 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 727 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 728 if (sigact_flag_test(act, SA_SIGINFO)) { 729 ps->ps_sigact[_SIG_IDX(sig)] = 730 (__sighandler_t *)act->sa_sigaction; 731 SIGADDSET(ps->ps_siginfo, sig); 732 } else { 733 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 734 SIGDELSET(ps->ps_siginfo, sig); 735 } 736 if (!sigact_flag_test(act, SA_RESTART)) 737 SIGADDSET(ps->ps_sigintr, sig); 738 else 739 SIGDELSET(ps->ps_sigintr, sig); 740 if (sigact_flag_test(act, SA_ONSTACK)) 741 SIGADDSET(ps->ps_sigonstack, sig); 742 else 743 SIGDELSET(ps->ps_sigonstack, sig); 744 if (sigact_flag_test(act, SA_RESETHAND)) 745 SIGADDSET(ps->ps_sigreset, sig); 746 else 747 SIGDELSET(ps->ps_sigreset, sig); 748 if (sigact_flag_test(act, SA_NODEFER)) 749 SIGADDSET(ps->ps_signodefer, sig); 750 else 751 SIGDELSET(ps->ps_signodefer, sig); 752 if (sig == SIGCHLD) { 753 if (act->sa_flags & SA_NOCLDSTOP) 754 ps->ps_flag |= PS_NOCLDSTOP; 755 else 756 ps->ps_flag &= ~PS_NOCLDSTOP; 757 if (act->sa_flags & SA_NOCLDWAIT) { 758 /* 759 * Paranoia: since SA_NOCLDWAIT is implemented 760 * by reparenting the dying child to PID 1 (and 761 * trust it to reap the zombie), PID 1 itself 762 * is forbidden to set SA_NOCLDWAIT. 763 */ 764 if (p->p_pid == 1) 765 ps->ps_flag &= ~PS_NOCLDWAIT; 766 else 767 ps->ps_flag |= PS_NOCLDWAIT; 768 } else 769 ps->ps_flag &= ~PS_NOCLDWAIT; 770 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 771 ps->ps_flag |= PS_CLDSIGIGN; 772 else 773 ps->ps_flag &= ~PS_CLDSIGIGN; 774 } 775 /* 776 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 777 * and for signals set to SIG_DFL where the default is to 778 * ignore. However, don't put SIGCONT in ps_sigignore, as we 779 * have to restart the process. 780 */ 781 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 782 (sigprop(sig) & SIGPROP_IGNORE && 783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 784 /* never to be seen again */ 785 sigqueue_delete_proc(p, sig); 786 if (sig != SIGCONT) 787 /* easier in psignal */ 788 SIGADDSET(ps->ps_sigignore, sig); 789 SIGDELSET(ps->ps_sigcatch, sig); 790 } else { 791 SIGDELSET(ps->ps_sigignore, sig); 792 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 793 SIGDELSET(ps->ps_sigcatch, sig); 794 else 795 SIGADDSET(ps->ps_sigcatch, sig); 796 } 797 #ifdef COMPAT_FREEBSD4 798 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 799 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 800 (flags & KSA_FREEBSD4) == 0) 801 SIGDELSET(ps->ps_freebsd4, sig); 802 else 803 SIGADDSET(ps->ps_freebsd4, sig); 804 #endif 805 #ifdef COMPAT_43 806 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 807 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 808 (flags & KSA_OSIGSET) == 0) 809 SIGDELSET(ps->ps_osigset, sig); 810 else 811 SIGADDSET(ps->ps_osigset, sig); 812 #endif 813 } 814 mtx_unlock(&ps->ps_mtx); 815 PROC_UNLOCK(p); 816 return (0); 817 } 818 819 #ifndef _SYS_SYSPROTO_H_ 820 struct sigaction_args { 821 int sig; 822 struct sigaction *act; 823 struct sigaction *oact; 824 }; 825 #endif 826 int 827 sys_sigaction(struct thread *td, struct sigaction_args *uap) 828 { 829 struct sigaction act, oact; 830 struct sigaction *actp, *oactp; 831 int error; 832 833 actp = (uap->act != NULL) ? &act : NULL; 834 oactp = (uap->oact != NULL) ? &oact : NULL; 835 if (actp) { 836 error = copyin(uap->act, actp, sizeof(act)); 837 if (error) 838 return (error); 839 } 840 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 841 if (oactp && !error) 842 error = copyout(oactp, uap->oact, sizeof(oact)); 843 return (error); 844 } 845 846 #ifdef COMPAT_FREEBSD4 847 #ifndef _SYS_SYSPROTO_H_ 848 struct freebsd4_sigaction_args { 849 int sig; 850 struct sigaction *act; 851 struct sigaction *oact; 852 }; 853 #endif 854 int 855 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 856 { 857 struct sigaction act, oact; 858 struct sigaction *actp, *oactp; 859 int error; 860 861 862 actp = (uap->act != NULL) ? &act : NULL; 863 oactp = (uap->oact != NULL) ? &oact : NULL; 864 if (actp) { 865 error = copyin(uap->act, actp, sizeof(act)); 866 if (error) 867 return (error); 868 } 869 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 870 if (oactp && !error) 871 error = copyout(oactp, uap->oact, sizeof(oact)); 872 return (error); 873 } 874 #endif /* COMAPT_FREEBSD4 */ 875 876 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 877 #ifndef _SYS_SYSPROTO_H_ 878 struct osigaction_args { 879 int signum; 880 struct osigaction *nsa; 881 struct osigaction *osa; 882 }; 883 #endif 884 int 885 osigaction(struct thread *td, struct osigaction_args *uap) 886 { 887 struct osigaction sa; 888 struct sigaction nsa, osa; 889 struct sigaction *nsap, *osap; 890 int error; 891 892 if (uap->signum <= 0 || uap->signum >= ONSIG) 893 return (EINVAL); 894 895 nsap = (uap->nsa != NULL) ? &nsa : NULL; 896 osap = (uap->osa != NULL) ? &osa : NULL; 897 898 if (nsap) { 899 error = copyin(uap->nsa, &sa, sizeof(sa)); 900 if (error) 901 return (error); 902 nsap->sa_handler = sa.sa_handler; 903 nsap->sa_flags = sa.sa_flags; 904 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 905 } 906 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 907 if (osap && !error) { 908 sa.sa_handler = osap->sa_handler; 909 sa.sa_flags = osap->sa_flags; 910 SIG2OSIG(osap->sa_mask, sa.sa_mask); 911 error = copyout(&sa, uap->osa, sizeof(sa)); 912 } 913 return (error); 914 } 915 916 #if !defined(__i386__) 917 /* Avoid replicating the same stub everywhere */ 918 int 919 osigreturn(struct thread *td, struct osigreturn_args *uap) 920 { 921 922 return (nosys(td, (struct nosys_args *)uap)); 923 } 924 #endif 925 #endif /* COMPAT_43 */ 926 927 /* 928 * Initialize signal state for process 0; 929 * set to ignore signals that are ignored by default. 930 */ 931 void 932 siginit(struct proc *p) 933 { 934 int i; 935 struct sigacts *ps; 936 937 PROC_LOCK(p); 938 ps = p->p_sigacts; 939 mtx_lock(&ps->ps_mtx); 940 for (i = 1; i <= NSIG; i++) { 941 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 942 SIGADDSET(ps->ps_sigignore, i); 943 } 944 } 945 mtx_unlock(&ps->ps_mtx); 946 PROC_UNLOCK(p); 947 } 948 949 /* 950 * Reset specified signal to the default disposition. 951 */ 952 static void 953 sigdflt(struct sigacts *ps, int sig) 954 { 955 956 mtx_assert(&ps->ps_mtx, MA_OWNED); 957 SIGDELSET(ps->ps_sigcatch, sig); 958 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 959 SIGADDSET(ps->ps_sigignore, sig); 960 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 961 SIGDELSET(ps->ps_siginfo, sig); 962 } 963 964 /* 965 * Reset signals for an exec of the specified process. 966 */ 967 void 968 execsigs(struct proc *p) 969 { 970 sigset_t osigignore; 971 struct sigacts *ps; 972 int sig; 973 struct thread *td; 974 975 /* 976 * Reset caught signals. Held signals remain held 977 * through td_sigmask (unless they were caught, 978 * and are now ignored by default). 979 */ 980 PROC_LOCK_ASSERT(p, MA_OWNED); 981 ps = p->p_sigacts; 982 mtx_lock(&ps->ps_mtx); 983 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 984 sig = sig_ffs(&ps->ps_sigcatch); 985 sigdflt(ps, sig); 986 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 987 sigqueue_delete_proc(p, sig); 988 } 989 990 /* 991 * As CloudABI processes cannot modify signal handlers, fully 992 * reset all signals to their default behavior. Do ignore 993 * SIGPIPE, as it would otherwise be impossible to recover from 994 * writes to broken pipes and sockets. 995 */ 996 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 997 osigignore = ps->ps_sigignore; 998 while (SIGNOTEMPTY(osigignore)) { 999 sig = sig_ffs(&osigignore); 1000 SIGDELSET(osigignore, sig); 1001 if (sig != SIGPIPE) 1002 sigdflt(ps, sig); 1003 } 1004 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1005 } 1006 1007 /* 1008 * Reset stack state to the user stack. 1009 * Clear set of signals caught on the signal stack. 1010 */ 1011 td = curthread; 1012 MPASS(td->td_proc == p); 1013 td->td_sigstk.ss_flags = SS_DISABLE; 1014 td->td_sigstk.ss_size = 0; 1015 td->td_sigstk.ss_sp = 0; 1016 td->td_pflags &= ~TDP_ALTSTACK; 1017 /* 1018 * Reset no zombies if child dies flag as Solaris does. 1019 */ 1020 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1021 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1022 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1023 mtx_unlock(&ps->ps_mtx); 1024 } 1025 1026 /* 1027 * kern_sigprocmask() 1028 * 1029 * Manipulate signal mask. 1030 */ 1031 int 1032 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1033 int flags) 1034 { 1035 sigset_t new_block, oset1; 1036 struct proc *p; 1037 int error; 1038 1039 p = td->td_proc; 1040 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1041 PROC_LOCK_ASSERT(p, MA_OWNED); 1042 else 1043 PROC_LOCK(p); 1044 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1045 ? MA_OWNED : MA_NOTOWNED); 1046 if (oset != NULL) 1047 *oset = td->td_sigmask; 1048 1049 error = 0; 1050 if (set != NULL) { 1051 switch (how) { 1052 case SIG_BLOCK: 1053 SIG_CANTMASK(*set); 1054 oset1 = td->td_sigmask; 1055 SIGSETOR(td->td_sigmask, *set); 1056 new_block = td->td_sigmask; 1057 SIGSETNAND(new_block, oset1); 1058 break; 1059 case SIG_UNBLOCK: 1060 SIGSETNAND(td->td_sigmask, *set); 1061 signotify(td); 1062 goto out; 1063 case SIG_SETMASK: 1064 SIG_CANTMASK(*set); 1065 oset1 = td->td_sigmask; 1066 if (flags & SIGPROCMASK_OLD) 1067 SIGSETLO(td->td_sigmask, *set); 1068 else 1069 td->td_sigmask = *set; 1070 new_block = td->td_sigmask; 1071 SIGSETNAND(new_block, oset1); 1072 signotify(td); 1073 break; 1074 default: 1075 error = EINVAL; 1076 goto out; 1077 } 1078 1079 /* 1080 * The new_block set contains signals that were not previously 1081 * blocked, but are blocked now. 1082 * 1083 * In case we block any signal that was not previously blocked 1084 * for td, and process has the signal pending, try to schedule 1085 * signal delivery to some thread that does not block the 1086 * signal, possibly waking it up. 1087 */ 1088 if (p->p_numthreads != 1) 1089 reschedule_signals(p, new_block, flags); 1090 } 1091 1092 out: 1093 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1094 PROC_UNLOCK(p); 1095 return (error); 1096 } 1097 1098 #ifndef _SYS_SYSPROTO_H_ 1099 struct sigprocmask_args { 1100 int how; 1101 const sigset_t *set; 1102 sigset_t *oset; 1103 }; 1104 #endif 1105 int 1106 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1107 { 1108 sigset_t set, oset; 1109 sigset_t *setp, *osetp; 1110 int error; 1111 1112 setp = (uap->set != NULL) ? &set : NULL; 1113 osetp = (uap->oset != NULL) ? &oset : NULL; 1114 if (setp) { 1115 error = copyin(uap->set, setp, sizeof(set)); 1116 if (error) 1117 return (error); 1118 } 1119 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1120 if (osetp && !error) { 1121 error = copyout(osetp, uap->oset, sizeof(oset)); 1122 } 1123 return (error); 1124 } 1125 1126 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1127 #ifndef _SYS_SYSPROTO_H_ 1128 struct osigprocmask_args { 1129 int how; 1130 osigset_t mask; 1131 }; 1132 #endif 1133 int 1134 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1135 { 1136 sigset_t set, oset; 1137 int error; 1138 1139 OSIG2SIG(uap->mask, set); 1140 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1141 SIG2OSIG(oset, td->td_retval[0]); 1142 return (error); 1143 } 1144 #endif /* COMPAT_43 */ 1145 1146 int 1147 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1148 { 1149 ksiginfo_t ksi; 1150 sigset_t set; 1151 int error; 1152 1153 error = copyin(uap->set, &set, sizeof(set)); 1154 if (error) { 1155 td->td_retval[0] = error; 1156 return (0); 1157 } 1158 1159 error = kern_sigtimedwait(td, set, &ksi, NULL); 1160 if (error) { 1161 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1162 error = ERESTART; 1163 if (error == ERESTART) 1164 return (error); 1165 td->td_retval[0] = error; 1166 return (0); 1167 } 1168 1169 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1170 td->td_retval[0] = error; 1171 return (0); 1172 } 1173 1174 int 1175 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1176 { 1177 struct timespec ts; 1178 struct timespec *timeout; 1179 sigset_t set; 1180 ksiginfo_t ksi; 1181 int error; 1182 1183 if (uap->timeout) { 1184 error = copyin(uap->timeout, &ts, sizeof(ts)); 1185 if (error) 1186 return (error); 1187 1188 timeout = &ts; 1189 } else 1190 timeout = NULL; 1191 1192 error = copyin(uap->set, &set, sizeof(set)); 1193 if (error) 1194 return (error); 1195 1196 error = kern_sigtimedwait(td, set, &ksi, timeout); 1197 if (error) 1198 return (error); 1199 1200 if (uap->info) 1201 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1202 1203 if (error == 0) 1204 td->td_retval[0] = ksi.ksi_signo; 1205 return (error); 1206 } 1207 1208 int 1209 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1210 { 1211 ksiginfo_t ksi; 1212 sigset_t set; 1213 int error; 1214 1215 error = copyin(uap->set, &set, sizeof(set)); 1216 if (error) 1217 return (error); 1218 1219 error = kern_sigtimedwait(td, set, &ksi, NULL); 1220 if (error) 1221 return (error); 1222 1223 if (uap->info) 1224 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1225 1226 if (error == 0) 1227 td->td_retval[0] = ksi.ksi_signo; 1228 return (error); 1229 } 1230 1231 static void 1232 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1233 { 1234 struct thread *thr; 1235 1236 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1237 if (thr == td) 1238 thr->td_si = *si; 1239 else 1240 thr->td_si.si_signo = 0; 1241 } 1242 } 1243 1244 int 1245 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1246 struct timespec *timeout) 1247 { 1248 struct sigacts *ps; 1249 sigset_t saved_mask, new_block; 1250 struct proc *p; 1251 int error, sig, timo, timevalid = 0; 1252 struct timespec rts, ets, ts; 1253 struct timeval tv; 1254 1255 p = td->td_proc; 1256 error = 0; 1257 ets.tv_sec = 0; 1258 ets.tv_nsec = 0; 1259 1260 if (timeout != NULL) { 1261 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1262 timevalid = 1; 1263 getnanouptime(&rts); 1264 timespecadd(&rts, timeout, &ets); 1265 } 1266 } 1267 ksiginfo_init(ksi); 1268 /* Some signals can not be waited for. */ 1269 SIG_CANTMASK(waitset); 1270 ps = p->p_sigacts; 1271 PROC_LOCK(p); 1272 saved_mask = td->td_sigmask; 1273 SIGSETNAND(td->td_sigmask, waitset); 1274 for (;;) { 1275 mtx_lock(&ps->ps_mtx); 1276 sig = cursig(td); 1277 mtx_unlock(&ps->ps_mtx); 1278 KASSERT(sig >= 0, ("sig %d", sig)); 1279 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1280 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1281 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1282 error = 0; 1283 break; 1284 } 1285 } 1286 1287 if (error != 0) 1288 break; 1289 1290 /* 1291 * POSIX says this must be checked after looking for pending 1292 * signals. 1293 */ 1294 if (timeout != NULL) { 1295 if (!timevalid) { 1296 error = EINVAL; 1297 break; 1298 } 1299 getnanouptime(&rts); 1300 if (timespeccmp(&rts, &ets, >=)) { 1301 error = EAGAIN; 1302 break; 1303 } 1304 timespecsub(&ets, &rts, &ts); 1305 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1306 timo = tvtohz(&tv); 1307 } else { 1308 timo = 0; 1309 } 1310 1311 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1312 1313 if (timeout != NULL) { 1314 if (error == ERESTART) { 1315 /* Timeout can not be restarted. */ 1316 error = EINTR; 1317 } else if (error == EAGAIN) { 1318 /* We will calculate timeout by ourself. */ 1319 error = 0; 1320 } 1321 } 1322 } 1323 1324 new_block = saved_mask; 1325 SIGSETNAND(new_block, td->td_sigmask); 1326 td->td_sigmask = saved_mask; 1327 /* 1328 * Fewer signals can be delivered to us, reschedule signal 1329 * notification. 1330 */ 1331 if (p->p_numthreads != 1) 1332 reschedule_signals(p, new_block, 0); 1333 1334 if (error == 0) { 1335 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1336 1337 if (ksi->ksi_code == SI_TIMER) 1338 itimer_accept(p, ksi->ksi_timerid, ksi); 1339 1340 #ifdef KTRACE 1341 if (KTRPOINT(td, KTR_PSIG)) { 1342 sig_t action; 1343 1344 mtx_lock(&ps->ps_mtx); 1345 action = ps->ps_sigact[_SIG_IDX(sig)]; 1346 mtx_unlock(&ps->ps_mtx); 1347 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1348 } 1349 #endif 1350 if (sig == SIGKILL) { 1351 proc_td_siginfo_capture(td, &ksi->ksi_info); 1352 sigexit(td, sig); 1353 } 1354 } 1355 PROC_UNLOCK(p); 1356 return (error); 1357 } 1358 1359 #ifndef _SYS_SYSPROTO_H_ 1360 struct sigpending_args { 1361 sigset_t *set; 1362 }; 1363 #endif 1364 int 1365 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1366 { 1367 struct proc *p = td->td_proc; 1368 sigset_t pending; 1369 1370 PROC_LOCK(p); 1371 pending = p->p_sigqueue.sq_signals; 1372 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1373 PROC_UNLOCK(p); 1374 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1375 } 1376 1377 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1378 #ifndef _SYS_SYSPROTO_H_ 1379 struct osigpending_args { 1380 int dummy; 1381 }; 1382 #endif 1383 int 1384 osigpending(struct thread *td, struct osigpending_args *uap) 1385 { 1386 struct proc *p = td->td_proc; 1387 sigset_t pending; 1388 1389 PROC_LOCK(p); 1390 pending = p->p_sigqueue.sq_signals; 1391 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1392 PROC_UNLOCK(p); 1393 SIG2OSIG(pending, td->td_retval[0]); 1394 return (0); 1395 } 1396 #endif /* COMPAT_43 */ 1397 1398 #if defined(COMPAT_43) 1399 /* 1400 * Generalized interface signal handler, 4.3-compatible. 1401 */ 1402 #ifndef _SYS_SYSPROTO_H_ 1403 struct osigvec_args { 1404 int signum; 1405 struct sigvec *nsv; 1406 struct sigvec *osv; 1407 }; 1408 #endif 1409 /* ARGSUSED */ 1410 int 1411 osigvec(struct thread *td, struct osigvec_args *uap) 1412 { 1413 struct sigvec vec; 1414 struct sigaction nsa, osa; 1415 struct sigaction *nsap, *osap; 1416 int error; 1417 1418 if (uap->signum <= 0 || uap->signum >= ONSIG) 1419 return (EINVAL); 1420 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1421 osap = (uap->osv != NULL) ? &osa : NULL; 1422 if (nsap) { 1423 error = copyin(uap->nsv, &vec, sizeof(vec)); 1424 if (error) 1425 return (error); 1426 nsap->sa_handler = vec.sv_handler; 1427 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1428 nsap->sa_flags = vec.sv_flags; 1429 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1430 } 1431 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1432 if (osap && !error) { 1433 vec.sv_handler = osap->sa_handler; 1434 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1435 vec.sv_flags = osap->sa_flags; 1436 vec.sv_flags &= ~SA_NOCLDWAIT; 1437 vec.sv_flags ^= SA_RESTART; 1438 error = copyout(&vec, uap->osv, sizeof(vec)); 1439 } 1440 return (error); 1441 } 1442 1443 #ifndef _SYS_SYSPROTO_H_ 1444 struct osigblock_args { 1445 int mask; 1446 }; 1447 #endif 1448 int 1449 osigblock(struct thread *td, struct osigblock_args *uap) 1450 { 1451 sigset_t set, oset; 1452 1453 OSIG2SIG(uap->mask, set); 1454 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1455 SIG2OSIG(oset, td->td_retval[0]); 1456 return (0); 1457 } 1458 1459 #ifndef _SYS_SYSPROTO_H_ 1460 struct osigsetmask_args { 1461 int mask; 1462 }; 1463 #endif 1464 int 1465 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1466 { 1467 sigset_t set, oset; 1468 1469 OSIG2SIG(uap->mask, set); 1470 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1471 SIG2OSIG(oset, td->td_retval[0]); 1472 return (0); 1473 } 1474 #endif /* COMPAT_43 */ 1475 1476 /* 1477 * Suspend calling thread until signal, providing mask to be set in the 1478 * meantime. 1479 */ 1480 #ifndef _SYS_SYSPROTO_H_ 1481 struct sigsuspend_args { 1482 const sigset_t *sigmask; 1483 }; 1484 #endif 1485 /* ARGSUSED */ 1486 int 1487 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1488 { 1489 sigset_t mask; 1490 int error; 1491 1492 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1493 if (error) 1494 return (error); 1495 return (kern_sigsuspend(td, mask)); 1496 } 1497 1498 int 1499 kern_sigsuspend(struct thread *td, sigset_t mask) 1500 { 1501 struct proc *p = td->td_proc; 1502 int has_sig, sig; 1503 1504 /* 1505 * When returning from sigsuspend, we want 1506 * the old mask to be restored after the 1507 * signal handler has finished. Thus, we 1508 * save it here and mark the sigacts structure 1509 * to indicate this. 1510 */ 1511 PROC_LOCK(p); 1512 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1513 SIGPROCMASK_PROC_LOCKED); 1514 td->td_pflags |= TDP_OLDMASK; 1515 1516 /* 1517 * Process signals now. Otherwise, we can get spurious wakeup 1518 * due to signal entered process queue, but delivered to other 1519 * thread. But sigsuspend should return only on signal 1520 * delivery. 1521 */ 1522 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1523 for (has_sig = 0; !has_sig;) { 1524 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1525 0) == 0) 1526 /* void */; 1527 thread_suspend_check(0); 1528 mtx_lock(&p->p_sigacts->ps_mtx); 1529 while ((sig = cursig(td)) != 0) { 1530 KASSERT(sig >= 0, ("sig %d", sig)); 1531 has_sig += postsig(sig); 1532 } 1533 mtx_unlock(&p->p_sigacts->ps_mtx); 1534 } 1535 PROC_UNLOCK(p); 1536 td->td_errno = EINTR; 1537 td->td_pflags |= TDP_NERRNO; 1538 return (EJUSTRETURN); 1539 } 1540 1541 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1542 /* 1543 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1544 * convention: libc stub passes mask, not pointer, to save a copyin. 1545 */ 1546 #ifndef _SYS_SYSPROTO_H_ 1547 struct osigsuspend_args { 1548 osigset_t mask; 1549 }; 1550 #endif 1551 /* ARGSUSED */ 1552 int 1553 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1554 { 1555 sigset_t mask; 1556 1557 OSIG2SIG(uap->mask, mask); 1558 return (kern_sigsuspend(td, mask)); 1559 } 1560 #endif /* COMPAT_43 */ 1561 1562 #if defined(COMPAT_43) 1563 #ifndef _SYS_SYSPROTO_H_ 1564 struct osigstack_args { 1565 struct sigstack *nss; 1566 struct sigstack *oss; 1567 }; 1568 #endif 1569 /* ARGSUSED */ 1570 int 1571 osigstack(struct thread *td, struct osigstack_args *uap) 1572 { 1573 struct sigstack nss, oss; 1574 int error = 0; 1575 1576 if (uap->nss != NULL) { 1577 error = copyin(uap->nss, &nss, sizeof(nss)); 1578 if (error) 1579 return (error); 1580 } 1581 oss.ss_sp = td->td_sigstk.ss_sp; 1582 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1583 if (uap->nss != NULL) { 1584 td->td_sigstk.ss_sp = nss.ss_sp; 1585 td->td_sigstk.ss_size = 0; 1586 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1587 td->td_pflags |= TDP_ALTSTACK; 1588 } 1589 if (uap->oss != NULL) 1590 error = copyout(&oss, uap->oss, sizeof(oss)); 1591 1592 return (error); 1593 } 1594 #endif /* COMPAT_43 */ 1595 1596 #ifndef _SYS_SYSPROTO_H_ 1597 struct sigaltstack_args { 1598 stack_t *ss; 1599 stack_t *oss; 1600 }; 1601 #endif 1602 /* ARGSUSED */ 1603 int 1604 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1605 { 1606 stack_t ss, oss; 1607 int error; 1608 1609 if (uap->ss != NULL) { 1610 error = copyin(uap->ss, &ss, sizeof(ss)); 1611 if (error) 1612 return (error); 1613 } 1614 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1615 (uap->oss != NULL) ? &oss : NULL); 1616 if (error) 1617 return (error); 1618 if (uap->oss != NULL) 1619 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1620 return (error); 1621 } 1622 1623 int 1624 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1625 { 1626 struct proc *p = td->td_proc; 1627 int oonstack; 1628 1629 oonstack = sigonstack(cpu_getstack(td)); 1630 1631 if (oss != NULL) { 1632 *oss = td->td_sigstk; 1633 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1634 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1635 } 1636 1637 if (ss != NULL) { 1638 if (oonstack) 1639 return (EPERM); 1640 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1641 return (EINVAL); 1642 if (!(ss->ss_flags & SS_DISABLE)) { 1643 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1644 return (ENOMEM); 1645 1646 td->td_sigstk = *ss; 1647 td->td_pflags |= TDP_ALTSTACK; 1648 } else { 1649 td->td_pflags &= ~TDP_ALTSTACK; 1650 } 1651 } 1652 return (0); 1653 } 1654 1655 /* 1656 * Common code for kill process group/broadcast kill. 1657 * cp is calling process. 1658 */ 1659 static int 1660 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1661 { 1662 struct proc *p; 1663 struct pgrp *pgrp; 1664 int err; 1665 int ret; 1666 1667 ret = ESRCH; 1668 if (all) { 1669 /* 1670 * broadcast 1671 */ 1672 sx_slock(&allproc_lock); 1673 FOREACH_PROC_IN_SYSTEM(p) { 1674 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1675 p == td->td_proc || p->p_state == PRS_NEW) { 1676 continue; 1677 } 1678 PROC_LOCK(p); 1679 err = p_cansignal(td, p, sig); 1680 if (err == 0) { 1681 if (sig) 1682 pksignal(p, sig, ksi); 1683 ret = err; 1684 } 1685 else if (ret == ESRCH) 1686 ret = err; 1687 PROC_UNLOCK(p); 1688 } 1689 sx_sunlock(&allproc_lock); 1690 } else { 1691 sx_slock(&proctree_lock); 1692 if (pgid == 0) { 1693 /* 1694 * zero pgid means send to my process group. 1695 */ 1696 pgrp = td->td_proc->p_pgrp; 1697 PGRP_LOCK(pgrp); 1698 } else { 1699 pgrp = pgfind(pgid); 1700 if (pgrp == NULL) { 1701 sx_sunlock(&proctree_lock); 1702 return (ESRCH); 1703 } 1704 } 1705 sx_sunlock(&proctree_lock); 1706 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1707 PROC_LOCK(p); 1708 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1709 p->p_state == PRS_NEW) { 1710 PROC_UNLOCK(p); 1711 continue; 1712 } 1713 err = p_cansignal(td, p, sig); 1714 if (err == 0) { 1715 if (sig) 1716 pksignal(p, sig, ksi); 1717 ret = err; 1718 } 1719 else if (ret == ESRCH) 1720 ret = err; 1721 PROC_UNLOCK(p); 1722 } 1723 PGRP_UNLOCK(pgrp); 1724 } 1725 return (ret); 1726 } 1727 1728 #ifndef _SYS_SYSPROTO_H_ 1729 struct kill_args { 1730 int pid; 1731 int signum; 1732 }; 1733 #endif 1734 /* ARGSUSED */ 1735 int 1736 sys_kill(struct thread *td, struct kill_args *uap) 1737 { 1738 ksiginfo_t ksi; 1739 struct proc *p; 1740 int error; 1741 1742 /* 1743 * A process in capability mode can send signals only to himself. 1744 * The main rationale behind this is that abort(3) is implemented as 1745 * kill(getpid(), SIGABRT). 1746 */ 1747 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1748 return (ECAPMODE); 1749 1750 AUDIT_ARG_SIGNUM(uap->signum); 1751 AUDIT_ARG_PID(uap->pid); 1752 if ((u_int)uap->signum > _SIG_MAXSIG) 1753 return (EINVAL); 1754 1755 ksiginfo_init(&ksi); 1756 ksi.ksi_signo = uap->signum; 1757 ksi.ksi_code = SI_USER; 1758 ksi.ksi_pid = td->td_proc->p_pid; 1759 ksi.ksi_uid = td->td_ucred->cr_ruid; 1760 1761 if (uap->pid > 0) { 1762 /* kill single process */ 1763 if ((p = pfind_any(uap->pid)) == NULL) 1764 return (ESRCH); 1765 AUDIT_ARG_PROCESS(p); 1766 error = p_cansignal(td, p, uap->signum); 1767 if (error == 0 && uap->signum) 1768 pksignal(p, uap->signum, &ksi); 1769 PROC_UNLOCK(p); 1770 return (error); 1771 } 1772 switch (uap->pid) { 1773 case -1: /* broadcast signal */ 1774 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1775 case 0: /* signal own process group */ 1776 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1777 default: /* negative explicit process group */ 1778 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1779 } 1780 /* NOTREACHED */ 1781 } 1782 1783 int 1784 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1785 { 1786 struct proc *p; 1787 int error; 1788 1789 AUDIT_ARG_SIGNUM(uap->signum); 1790 AUDIT_ARG_FD(uap->fd); 1791 if ((u_int)uap->signum > _SIG_MAXSIG) 1792 return (EINVAL); 1793 1794 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1795 if (error) 1796 return (error); 1797 AUDIT_ARG_PROCESS(p); 1798 error = p_cansignal(td, p, uap->signum); 1799 if (error == 0 && uap->signum) 1800 kern_psignal(p, uap->signum); 1801 PROC_UNLOCK(p); 1802 return (error); 1803 } 1804 1805 #if defined(COMPAT_43) 1806 #ifndef _SYS_SYSPROTO_H_ 1807 struct okillpg_args { 1808 int pgid; 1809 int signum; 1810 }; 1811 #endif 1812 /* ARGSUSED */ 1813 int 1814 okillpg(struct thread *td, struct okillpg_args *uap) 1815 { 1816 ksiginfo_t ksi; 1817 1818 AUDIT_ARG_SIGNUM(uap->signum); 1819 AUDIT_ARG_PID(uap->pgid); 1820 if ((u_int)uap->signum > _SIG_MAXSIG) 1821 return (EINVAL); 1822 1823 ksiginfo_init(&ksi); 1824 ksi.ksi_signo = uap->signum; 1825 ksi.ksi_code = SI_USER; 1826 ksi.ksi_pid = td->td_proc->p_pid; 1827 ksi.ksi_uid = td->td_ucred->cr_ruid; 1828 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1829 } 1830 #endif /* COMPAT_43 */ 1831 1832 #ifndef _SYS_SYSPROTO_H_ 1833 struct sigqueue_args { 1834 pid_t pid; 1835 int signum; 1836 /* union sigval */ void *value; 1837 }; 1838 #endif 1839 int 1840 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1841 { 1842 union sigval sv; 1843 1844 sv.sival_ptr = uap->value; 1845 1846 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1847 } 1848 1849 int 1850 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1851 { 1852 ksiginfo_t ksi; 1853 struct proc *p; 1854 int error; 1855 1856 if ((u_int)signum > _SIG_MAXSIG) 1857 return (EINVAL); 1858 1859 /* 1860 * Specification says sigqueue can only send signal to 1861 * single process. 1862 */ 1863 if (pid <= 0) 1864 return (EINVAL); 1865 1866 if ((p = pfind_any(pid)) == NULL) 1867 return (ESRCH); 1868 error = p_cansignal(td, p, signum); 1869 if (error == 0 && signum != 0) { 1870 ksiginfo_init(&ksi); 1871 ksi.ksi_flags = KSI_SIGQ; 1872 ksi.ksi_signo = signum; 1873 ksi.ksi_code = SI_QUEUE; 1874 ksi.ksi_pid = td->td_proc->p_pid; 1875 ksi.ksi_uid = td->td_ucred->cr_ruid; 1876 ksi.ksi_value = *value; 1877 error = pksignal(p, ksi.ksi_signo, &ksi); 1878 } 1879 PROC_UNLOCK(p); 1880 return (error); 1881 } 1882 1883 /* 1884 * Send a signal to a process group. 1885 */ 1886 void 1887 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1888 { 1889 struct pgrp *pgrp; 1890 1891 if (pgid != 0) { 1892 sx_slock(&proctree_lock); 1893 pgrp = pgfind(pgid); 1894 sx_sunlock(&proctree_lock); 1895 if (pgrp != NULL) { 1896 pgsignal(pgrp, sig, 0, ksi); 1897 PGRP_UNLOCK(pgrp); 1898 } 1899 } 1900 } 1901 1902 /* 1903 * Send a signal to a process group. If checktty is 1, 1904 * limit to members which have a controlling terminal. 1905 */ 1906 void 1907 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1908 { 1909 struct proc *p; 1910 1911 if (pgrp) { 1912 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1913 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1914 PROC_LOCK(p); 1915 if (p->p_state == PRS_NORMAL && 1916 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1917 pksignal(p, sig, ksi); 1918 PROC_UNLOCK(p); 1919 } 1920 } 1921 } 1922 1923 1924 /* 1925 * Recalculate the signal mask and reset the signal disposition after 1926 * usermode frame for delivery is formed. Should be called after 1927 * mach-specific routine, because sysent->sv_sendsig() needs correct 1928 * ps_siginfo and signal mask. 1929 */ 1930 static void 1931 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1932 { 1933 sigset_t mask; 1934 1935 mtx_assert(&ps->ps_mtx, MA_OWNED); 1936 td->td_ru.ru_nsignals++; 1937 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1938 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1939 SIGADDSET(mask, sig); 1940 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1941 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1942 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1943 sigdflt(ps, sig); 1944 } 1945 1946 1947 /* 1948 * Send a signal caused by a trap to the current thread. If it will be 1949 * caught immediately, deliver it with correct code. Otherwise, post it 1950 * normally. 1951 */ 1952 void 1953 trapsignal(struct thread *td, ksiginfo_t *ksi) 1954 { 1955 struct sigacts *ps; 1956 struct proc *p; 1957 int sig; 1958 int code; 1959 1960 p = td->td_proc; 1961 sig = ksi->ksi_signo; 1962 code = ksi->ksi_code; 1963 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1964 1965 PROC_LOCK(p); 1966 ps = p->p_sigacts; 1967 mtx_lock(&ps->ps_mtx); 1968 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1969 !SIGISMEMBER(td->td_sigmask, sig)) { 1970 #ifdef KTRACE 1971 if (KTRPOINT(curthread, KTR_PSIG)) 1972 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1973 &td->td_sigmask, code); 1974 #endif 1975 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1976 ksi, &td->td_sigmask); 1977 postsig_done(sig, td, ps); 1978 mtx_unlock(&ps->ps_mtx); 1979 } else { 1980 /* 1981 * Avoid a possible infinite loop if the thread 1982 * masking the signal or process is ignoring the 1983 * signal. 1984 */ 1985 if (kern_forcesigexit && 1986 (SIGISMEMBER(td->td_sigmask, sig) || 1987 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1988 SIGDELSET(td->td_sigmask, sig); 1989 SIGDELSET(ps->ps_sigcatch, sig); 1990 SIGDELSET(ps->ps_sigignore, sig); 1991 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1992 } 1993 mtx_unlock(&ps->ps_mtx); 1994 p->p_code = code; /* XXX for core dump/debugger */ 1995 p->p_sig = sig; /* XXX to verify code */ 1996 tdsendsignal(p, td, sig, ksi); 1997 } 1998 PROC_UNLOCK(p); 1999 } 2000 2001 static struct thread * 2002 sigtd(struct proc *p, int sig, int prop) 2003 { 2004 struct thread *td, *signal_td; 2005 2006 PROC_LOCK_ASSERT(p, MA_OWNED); 2007 2008 /* 2009 * Check if current thread can handle the signal without 2010 * switching context to another thread. 2011 */ 2012 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2013 return (curthread); 2014 signal_td = NULL; 2015 FOREACH_THREAD_IN_PROC(p, td) { 2016 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2017 signal_td = td; 2018 break; 2019 } 2020 } 2021 if (signal_td == NULL) 2022 signal_td = FIRST_THREAD_IN_PROC(p); 2023 return (signal_td); 2024 } 2025 2026 /* 2027 * Send the signal to the process. If the signal has an action, the action 2028 * is usually performed by the target process rather than the caller; we add 2029 * the signal to the set of pending signals for the process. 2030 * 2031 * Exceptions: 2032 * o When a stop signal is sent to a sleeping process that takes the 2033 * default action, the process is stopped without awakening it. 2034 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2035 * regardless of the signal action (eg, blocked or ignored). 2036 * 2037 * Other ignored signals are discarded immediately. 2038 * 2039 * NB: This function may be entered from the debugger via the "kill" DDB 2040 * command. There is little that can be done to mitigate the possibly messy 2041 * side effects of this unwise possibility. 2042 */ 2043 void 2044 kern_psignal(struct proc *p, int sig) 2045 { 2046 ksiginfo_t ksi; 2047 2048 ksiginfo_init(&ksi); 2049 ksi.ksi_signo = sig; 2050 ksi.ksi_code = SI_KERNEL; 2051 (void) tdsendsignal(p, NULL, sig, &ksi); 2052 } 2053 2054 int 2055 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2056 { 2057 2058 return (tdsendsignal(p, NULL, sig, ksi)); 2059 } 2060 2061 /* Utility function for finding a thread to send signal event to. */ 2062 int 2063 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2064 { 2065 struct thread *td; 2066 2067 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2068 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2069 if (td == NULL) 2070 return (ESRCH); 2071 *ttd = td; 2072 } else { 2073 *ttd = NULL; 2074 PROC_LOCK(p); 2075 } 2076 return (0); 2077 } 2078 2079 void 2080 tdsignal(struct thread *td, int sig) 2081 { 2082 ksiginfo_t ksi; 2083 2084 ksiginfo_init(&ksi); 2085 ksi.ksi_signo = sig; 2086 ksi.ksi_code = SI_KERNEL; 2087 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2088 } 2089 2090 void 2091 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2092 { 2093 2094 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2095 } 2096 2097 int 2098 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2099 { 2100 sig_t action; 2101 sigqueue_t *sigqueue; 2102 int prop; 2103 struct sigacts *ps; 2104 int intrval; 2105 int ret = 0; 2106 int wakeup_swapper; 2107 2108 MPASS(td == NULL || p == td->td_proc); 2109 PROC_LOCK_ASSERT(p, MA_OWNED); 2110 2111 if (!_SIG_VALID(sig)) 2112 panic("%s(): invalid signal %d", __func__, sig); 2113 2114 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2115 2116 /* 2117 * IEEE Std 1003.1-2001: return success when killing a zombie. 2118 */ 2119 if (p->p_state == PRS_ZOMBIE) { 2120 if (ksi && (ksi->ksi_flags & KSI_INS)) 2121 ksiginfo_tryfree(ksi); 2122 return (ret); 2123 } 2124 2125 ps = p->p_sigacts; 2126 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2127 prop = sigprop(sig); 2128 2129 if (td == NULL) { 2130 td = sigtd(p, sig, prop); 2131 sigqueue = &p->p_sigqueue; 2132 } else 2133 sigqueue = &td->td_sigqueue; 2134 2135 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2136 2137 /* 2138 * If the signal is being ignored, 2139 * then we forget about it immediately. 2140 * (Note: we don't set SIGCONT in ps_sigignore, 2141 * and if it is set to SIG_IGN, 2142 * action will be SIG_DFL here.) 2143 */ 2144 mtx_lock(&ps->ps_mtx); 2145 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2146 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2147 2148 mtx_unlock(&ps->ps_mtx); 2149 if (ksi && (ksi->ksi_flags & KSI_INS)) 2150 ksiginfo_tryfree(ksi); 2151 return (ret); 2152 } 2153 if (SIGISMEMBER(td->td_sigmask, sig)) 2154 action = SIG_HOLD; 2155 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2156 action = SIG_CATCH; 2157 else 2158 action = SIG_DFL; 2159 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2160 intrval = EINTR; 2161 else 2162 intrval = ERESTART; 2163 mtx_unlock(&ps->ps_mtx); 2164 2165 if (prop & SIGPROP_CONT) 2166 sigqueue_delete_stopmask_proc(p); 2167 else if (prop & SIGPROP_STOP) { 2168 /* 2169 * If sending a tty stop signal to a member of an orphaned 2170 * process group, discard the signal here if the action 2171 * is default; don't stop the process below if sleeping, 2172 * and don't clear any pending SIGCONT. 2173 */ 2174 if ((prop & SIGPROP_TTYSTOP) && 2175 (p->p_pgrp->pg_jobc == 0) && 2176 (action == SIG_DFL)) { 2177 if (ksi && (ksi->ksi_flags & KSI_INS)) 2178 ksiginfo_tryfree(ksi); 2179 return (ret); 2180 } 2181 sigqueue_delete_proc(p, SIGCONT); 2182 if (p->p_flag & P_CONTINUED) { 2183 p->p_flag &= ~P_CONTINUED; 2184 PROC_LOCK(p->p_pptr); 2185 sigqueue_take(p->p_ksi); 2186 PROC_UNLOCK(p->p_pptr); 2187 } 2188 } 2189 2190 ret = sigqueue_add(sigqueue, sig, ksi); 2191 if (ret != 0) 2192 return (ret); 2193 signotify(td); 2194 /* 2195 * Defer further processing for signals which are held, 2196 * except that stopped processes must be continued by SIGCONT. 2197 */ 2198 if (action == SIG_HOLD && 2199 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2200 return (ret); 2201 2202 /* SIGKILL: Remove procfs STOPEVENTs. */ 2203 if (sig == SIGKILL) { 2204 /* from procfs_ioctl.c: PIOCBIC */ 2205 p->p_stops = 0; 2206 /* from procfs_ioctl.c: PIOCCONT */ 2207 p->p_step = 0; 2208 wakeup(&p->p_step); 2209 } 2210 /* 2211 * Some signals have a process-wide effect and a per-thread 2212 * component. Most processing occurs when the process next 2213 * tries to cross the user boundary, however there are some 2214 * times when processing needs to be done immediately, such as 2215 * waking up threads so that they can cross the user boundary. 2216 * We try to do the per-process part here. 2217 */ 2218 if (P_SHOULDSTOP(p)) { 2219 KASSERT(!(p->p_flag & P_WEXIT), 2220 ("signal to stopped but exiting process")); 2221 if (sig == SIGKILL) { 2222 /* 2223 * If traced process is already stopped, 2224 * then no further action is necessary. 2225 */ 2226 if (p->p_flag & P_TRACED) 2227 goto out; 2228 /* 2229 * SIGKILL sets process running. 2230 * It will die elsewhere. 2231 * All threads must be restarted. 2232 */ 2233 p->p_flag &= ~P_STOPPED_SIG; 2234 goto runfast; 2235 } 2236 2237 if (prop & SIGPROP_CONT) { 2238 /* 2239 * If traced process is already stopped, 2240 * then no further action is necessary. 2241 */ 2242 if (p->p_flag & P_TRACED) 2243 goto out; 2244 /* 2245 * If SIGCONT is default (or ignored), we continue the 2246 * process but don't leave the signal in sigqueue as 2247 * it has no further action. If SIGCONT is held, we 2248 * continue the process and leave the signal in 2249 * sigqueue. If the process catches SIGCONT, let it 2250 * handle the signal itself. If it isn't waiting on 2251 * an event, it goes back to run state. 2252 * Otherwise, process goes back to sleep state. 2253 */ 2254 p->p_flag &= ~P_STOPPED_SIG; 2255 PROC_SLOCK(p); 2256 if (p->p_numthreads == p->p_suspcount) { 2257 PROC_SUNLOCK(p); 2258 p->p_flag |= P_CONTINUED; 2259 p->p_xsig = SIGCONT; 2260 PROC_LOCK(p->p_pptr); 2261 childproc_continued(p); 2262 PROC_UNLOCK(p->p_pptr); 2263 PROC_SLOCK(p); 2264 } 2265 if (action == SIG_DFL) { 2266 thread_unsuspend(p); 2267 PROC_SUNLOCK(p); 2268 sigqueue_delete(sigqueue, sig); 2269 goto out; 2270 } 2271 if (action == SIG_CATCH) { 2272 /* 2273 * The process wants to catch it so it needs 2274 * to run at least one thread, but which one? 2275 */ 2276 PROC_SUNLOCK(p); 2277 goto runfast; 2278 } 2279 /* 2280 * The signal is not ignored or caught. 2281 */ 2282 thread_unsuspend(p); 2283 PROC_SUNLOCK(p); 2284 goto out; 2285 } 2286 2287 if (prop & SIGPROP_STOP) { 2288 /* 2289 * If traced process is already stopped, 2290 * then no further action is necessary. 2291 */ 2292 if (p->p_flag & P_TRACED) 2293 goto out; 2294 /* 2295 * Already stopped, don't need to stop again 2296 * (If we did the shell could get confused). 2297 * Just make sure the signal STOP bit set. 2298 */ 2299 p->p_flag |= P_STOPPED_SIG; 2300 sigqueue_delete(sigqueue, sig); 2301 goto out; 2302 } 2303 2304 /* 2305 * All other kinds of signals: 2306 * If a thread is sleeping interruptibly, simulate a 2307 * wakeup so that when it is continued it will be made 2308 * runnable and can look at the signal. However, don't make 2309 * the PROCESS runnable, leave it stopped. 2310 * It may run a bit until it hits a thread_suspend_check(). 2311 */ 2312 wakeup_swapper = 0; 2313 PROC_SLOCK(p); 2314 thread_lock(td); 2315 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2316 wakeup_swapper = sleepq_abort(td, intrval); 2317 thread_unlock(td); 2318 PROC_SUNLOCK(p); 2319 if (wakeup_swapper) 2320 kick_proc0(); 2321 goto out; 2322 /* 2323 * Mutexes are short lived. Threads waiting on them will 2324 * hit thread_suspend_check() soon. 2325 */ 2326 } else if (p->p_state == PRS_NORMAL) { 2327 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2328 tdsigwakeup(td, sig, action, intrval); 2329 goto out; 2330 } 2331 2332 MPASS(action == SIG_DFL); 2333 2334 if (prop & SIGPROP_STOP) { 2335 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2336 goto out; 2337 p->p_flag |= P_STOPPED_SIG; 2338 p->p_xsig = sig; 2339 PROC_SLOCK(p); 2340 wakeup_swapper = sig_suspend_threads(td, p, 1); 2341 if (p->p_numthreads == p->p_suspcount) { 2342 /* 2343 * only thread sending signal to another 2344 * process can reach here, if thread is sending 2345 * signal to its process, because thread does 2346 * not suspend itself here, p_numthreads 2347 * should never be equal to p_suspcount. 2348 */ 2349 thread_stopped(p); 2350 PROC_SUNLOCK(p); 2351 sigqueue_delete_proc(p, p->p_xsig); 2352 } else 2353 PROC_SUNLOCK(p); 2354 if (wakeup_swapper) 2355 kick_proc0(); 2356 goto out; 2357 } 2358 } else { 2359 /* Not in "NORMAL" state. discard the signal. */ 2360 sigqueue_delete(sigqueue, sig); 2361 goto out; 2362 } 2363 2364 /* 2365 * The process is not stopped so we need to apply the signal to all the 2366 * running threads. 2367 */ 2368 runfast: 2369 tdsigwakeup(td, sig, action, intrval); 2370 PROC_SLOCK(p); 2371 thread_unsuspend(p); 2372 PROC_SUNLOCK(p); 2373 out: 2374 /* If we jump here, proc slock should not be owned. */ 2375 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2376 return (ret); 2377 } 2378 2379 /* 2380 * The force of a signal has been directed against a single 2381 * thread. We need to see what we can do about knocking it 2382 * out of any sleep it may be in etc. 2383 */ 2384 static void 2385 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2386 { 2387 struct proc *p = td->td_proc; 2388 int prop; 2389 int wakeup_swapper; 2390 2391 wakeup_swapper = 0; 2392 PROC_LOCK_ASSERT(p, MA_OWNED); 2393 prop = sigprop(sig); 2394 2395 PROC_SLOCK(p); 2396 thread_lock(td); 2397 /* 2398 * Bring the priority of a thread up if we want it to get 2399 * killed in this lifetime. Be careful to avoid bumping the 2400 * priority of the idle thread, since we still allow to signal 2401 * kernel processes. 2402 */ 2403 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2404 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2405 sched_prio(td, PUSER); 2406 if (TD_ON_SLEEPQ(td)) { 2407 /* 2408 * If thread is sleeping uninterruptibly 2409 * we can't interrupt the sleep... the signal will 2410 * be noticed when the process returns through 2411 * trap() or syscall(). 2412 */ 2413 if ((td->td_flags & TDF_SINTR) == 0) 2414 goto out; 2415 /* 2416 * If SIGCONT is default (or ignored) and process is 2417 * asleep, we are finished; the process should not 2418 * be awakened. 2419 */ 2420 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2421 thread_unlock(td); 2422 PROC_SUNLOCK(p); 2423 sigqueue_delete(&p->p_sigqueue, sig); 2424 /* 2425 * It may be on either list in this state. 2426 * Remove from both for now. 2427 */ 2428 sigqueue_delete(&td->td_sigqueue, sig); 2429 return; 2430 } 2431 2432 /* 2433 * Don't awaken a sleeping thread for SIGSTOP if the 2434 * STOP signal is deferred. 2435 */ 2436 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2437 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2438 goto out; 2439 2440 /* 2441 * Give low priority threads a better chance to run. 2442 */ 2443 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2444 sched_prio(td, PUSER); 2445 2446 wakeup_swapper = sleepq_abort(td, intrval); 2447 } else { 2448 /* 2449 * Other states do nothing with the signal immediately, 2450 * other than kicking ourselves if we are running. 2451 * It will either never be noticed, or noticed very soon. 2452 */ 2453 #ifdef SMP 2454 if (TD_IS_RUNNING(td) && td != curthread) 2455 forward_signal(td); 2456 #endif 2457 } 2458 out: 2459 PROC_SUNLOCK(p); 2460 thread_unlock(td); 2461 if (wakeup_swapper) 2462 kick_proc0(); 2463 } 2464 2465 static int 2466 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2467 { 2468 struct thread *td2; 2469 int wakeup_swapper; 2470 2471 PROC_LOCK_ASSERT(p, MA_OWNED); 2472 PROC_SLOCK_ASSERT(p, MA_OWNED); 2473 MPASS(sending || td == curthread); 2474 2475 wakeup_swapper = 0; 2476 FOREACH_THREAD_IN_PROC(p, td2) { 2477 thread_lock(td2); 2478 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2479 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2480 (td2->td_flags & TDF_SINTR)) { 2481 if (td2->td_flags & TDF_SBDRY) { 2482 /* 2483 * Once a thread is asleep with 2484 * TDF_SBDRY and without TDF_SERESTART 2485 * or TDF_SEINTR set, it should never 2486 * become suspended due to this check. 2487 */ 2488 KASSERT(!TD_IS_SUSPENDED(td2), 2489 ("thread with deferred stops suspended")); 2490 if (TD_SBDRY_INTR(td2)) 2491 wakeup_swapper |= sleepq_abort(td2, 2492 TD_SBDRY_ERRNO(td2)); 2493 } else if (!TD_IS_SUSPENDED(td2)) { 2494 thread_suspend_one(td2); 2495 } 2496 } else if (!TD_IS_SUSPENDED(td2)) { 2497 if (sending || td != td2) 2498 td2->td_flags |= TDF_ASTPENDING; 2499 #ifdef SMP 2500 if (TD_IS_RUNNING(td2) && td2 != td) 2501 forward_signal(td2); 2502 #endif 2503 } 2504 thread_unlock(td2); 2505 } 2506 return (wakeup_swapper); 2507 } 2508 2509 /* 2510 * Stop the process for an event deemed interesting to the debugger. If si is 2511 * non-NULL, this is a signal exchange; the new signal requested by the 2512 * debugger will be returned for handling. If si is NULL, this is some other 2513 * type of interesting event. The debugger may request a signal be delivered in 2514 * that case as well, however it will be deferred until it can be handled. 2515 */ 2516 int 2517 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2518 { 2519 struct proc *p = td->td_proc; 2520 struct thread *td2; 2521 ksiginfo_t ksi; 2522 int prop; 2523 2524 PROC_LOCK_ASSERT(p, MA_OWNED); 2525 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2526 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2527 &p->p_mtx.lock_object, "Stopping for traced signal"); 2528 2529 td->td_xsig = sig; 2530 2531 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2532 td->td_dbgflags |= TDB_XSIG; 2533 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2534 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2535 PROC_SLOCK(p); 2536 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2537 if (P_KILLED(p)) { 2538 /* 2539 * Ensure that, if we've been PT_KILLed, the 2540 * exit status reflects that. Another thread 2541 * may also be in ptracestop(), having just 2542 * received the SIGKILL, but this thread was 2543 * unsuspended first. 2544 */ 2545 td->td_dbgflags &= ~TDB_XSIG; 2546 td->td_xsig = SIGKILL; 2547 p->p_ptevents = 0; 2548 break; 2549 } 2550 if (p->p_flag & P_SINGLE_EXIT && 2551 !(td->td_dbgflags & TDB_EXIT)) { 2552 /* 2553 * Ignore ptrace stops except for thread exit 2554 * events when the process exits. 2555 */ 2556 td->td_dbgflags &= ~TDB_XSIG; 2557 PROC_SUNLOCK(p); 2558 return (0); 2559 } 2560 2561 /* 2562 * Make wait(2) work. Ensure that right after the 2563 * attach, the thread which was decided to become the 2564 * leader of attach gets reported to the waiter. 2565 * Otherwise, just avoid overwriting another thread's 2566 * assignment to p_xthread. If another thread has 2567 * already set p_xthread, the current thread will get 2568 * a chance to report itself upon the next iteration. 2569 */ 2570 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2571 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2572 p->p_xthread == NULL)) { 2573 p->p_xsig = sig; 2574 p->p_xthread = td; 2575 td->td_dbgflags &= ~TDB_FSTP; 2576 p->p_flag2 &= ~P2_PTRACE_FSTP; 2577 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2578 sig_suspend_threads(td, p, 0); 2579 } 2580 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2581 td->td_dbgflags &= ~TDB_STOPATFORK; 2582 } 2583 stopme: 2584 thread_suspend_switch(td, p); 2585 if (p->p_xthread == td) 2586 p->p_xthread = NULL; 2587 if (!(p->p_flag & P_TRACED)) 2588 break; 2589 if (td->td_dbgflags & TDB_SUSPEND) { 2590 if (p->p_flag & P_SINGLE_EXIT) 2591 break; 2592 goto stopme; 2593 } 2594 } 2595 PROC_SUNLOCK(p); 2596 } 2597 2598 if (si != NULL && sig == td->td_xsig) { 2599 /* Parent wants us to take the original signal unchanged. */ 2600 si->ksi_flags |= KSI_HEAD; 2601 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2602 si->ksi_signo = 0; 2603 } else if (td->td_xsig != 0) { 2604 /* 2605 * If parent wants us to take a new signal, then it will leave 2606 * it in td->td_xsig; otherwise we just look for signals again. 2607 */ 2608 ksiginfo_init(&ksi); 2609 ksi.ksi_signo = td->td_xsig; 2610 ksi.ksi_flags |= KSI_PTRACE; 2611 prop = sigprop(td->td_xsig); 2612 td2 = sigtd(p, td->td_xsig, prop); 2613 tdsendsignal(p, td2, td->td_xsig, &ksi); 2614 if (td != td2) 2615 return (0); 2616 } 2617 2618 return (td->td_xsig); 2619 } 2620 2621 static void 2622 reschedule_signals(struct proc *p, sigset_t block, int flags) 2623 { 2624 struct sigacts *ps; 2625 struct thread *td; 2626 int sig; 2627 2628 PROC_LOCK_ASSERT(p, MA_OWNED); 2629 ps = p->p_sigacts; 2630 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2631 MA_OWNED : MA_NOTOWNED); 2632 if (SIGISEMPTY(p->p_siglist)) 2633 return; 2634 SIGSETAND(block, p->p_siglist); 2635 while ((sig = sig_ffs(&block)) != 0) { 2636 SIGDELSET(block, sig); 2637 td = sigtd(p, sig, 0); 2638 signotify(td); 2639 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2640 mtx_lock(&ps->ps_mtx); 2641 if (p->p_flag & P_TRACED || 2642 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2643 !SIGISMEMBER(td->td_sigmask, sig))) 2644 tdsigwakeup(td, sig, SIG_CATCH, 2645 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2646 ERESTART)); 2647 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2648 mtx_unlock(&ps->ps_mtx); 2649 } 2650 } 2651 2652 void 2653 tdsigcleanup(struct thread *td) 2654 { 2655 struct proc *p; 2656 sigset_t unblocked; 2657 2658 p = td->td_proc; 2659 PROC_LOCK_ASSERT(p, MA_OWNED); 2660 2661 sigqueue_flush(&td->td_sigqueue); 2662 if (p->p_numthreads == 1) 2663 return; 2664 2665 /* 2666 * Since we cannot handle signals, notify signal post code 2667 * about this by filling the sigmask. 2668 * 2669 * Also, if needed, wake up thread(s) that do not block the 2670 * same signals as the exiting thread, since the thread might 2671 * have been selected for delivery and woken up. 2672 */ 2673 SIGFILLSET(unblocked); 2674 SIGSETNAND(unblocked, td->td_sigmask); 2675 SIGFILLSET(td->td_sigmask); 2676 reschedule_signals(p, unblocked, 0); 2677 2678 } 2679 2680 static int 2681 sigdeferstop_curr_flags(int cflags) 2682 { 2683 2684 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2685 (cflags & TDF_SBDRY) != 0); 2686 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2687 } 2688 2689 /* 2690 * Defer the delivery of SIGSTOP for the current thread, according to 2691 * the requested mode. Returns previous flags, which must be restored 2692 * by sigallowstop(). 2693 * 2694 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2695 * cleared by the current thread, which allow the lock-less read-only 2696 * accesses below. 2697 */ 2698 int 2699 sigdeferstop_impl(int mode) 2700 { 2701 struct thread *td; 2702 int cflags, nflags; 2703 2704 td = curthread; 2705 cflags = sigdeferstop_curr_flags(td->td_flags); 2706 switch (mode) { 2707 case SIGDEFERSTOP_NOP: 2708 nflags = cflags; 2709 break; 2710 case SIGDEFERSTOP_OFF: 2711 nflags = 0; 2712 break; 2713 case SIGDEFERSTOP_SILENT: 2714 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2715 break; 2716 case SIGDEFERSTOP_EINTR: 2717 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2718 break; 2719 case SIGDEFERSTOP_ERESTART: 2720 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2721 break; 2722 default: 2723 panic("sigdeferstop: invalid mode %x", mode); 2724 break; 2725 } 2726 if (cflags == nflags) 2727 return (SIGDEFERSTOP_VAL_NCHG); 2728 thread_lock(td); 2729 td->td_flags = (td->td_flags & ~cflags) | nflags; 2730 thread_unlock(td); 2731 return (cflags); 2732 } 2733 2734 /* 2735 * Restores the STOP handling mode, typically permitting the delivery 2736 * of SIGSTOP for the current thread. This does not immediately 2737 * suspend if a stop was posted. Instead, the thread will suspend 2738 * either via ast() or a subsequent interruptible sleep. 2739 */ 2740 void 2741 sigallowstop_impl(int prev) 2742 { 2743 struct thread *td; 2744 int cflags; 2745 2746 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2747 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2748 ("sigallowstop: incorrect previous mode %x", prev)); 2749 td = curthread; 2750 cflags = sigdeferstop_curr_flags(td->td_flags); 2751 if (cflags != prev) { 2752 thread_lock(td); 2753 td->td_flags = (td->td_flags & ~cflags) | prev; 2754 thread_unlock(td); 2755 } 2756 } 2757 2758 /* 2759 * If the current process has received a signal (should be caught or cause 2760 * termination, should interrupt current syscall), return the signal number. 2761 * Stop signals with default action are processed immediately, then cleared; 2762 * they aren't returned. This is checked after each entry to the system for 2763 * a syscall or trap (though this can usually be done without calling issignal 2764 * by checking the pending signal masks in cursig.) The normal call 2765 * sequence is 2766 * 2767 * while (sig = cursig(curthread)) 2768 * postsig(sig); 2769 */ 2770 static int 2771 issignal(struct thread *td) 2772 { 2773 struct proc *p; 2774 struct sigacts *ps; 2775 struct sigqueue *queue; 2776 sigset_t sigpending; 2777 ksiginfo_t ksi; 2778 int prop, sig, traced; 2779 2780 p = td->td_proc; 2781 ps = p->p_sigacts; 2782 mtx_assert(&ps->ps_mtx, MA_OWNED); 2783 PROC_LOCK_ASSERT(p, MA_OWNED); 2784 for (;;) { 2785 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2786 2787 sigpending = td->td_sigqueue.sq_signals; 2788 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2789 SIGSETNAND(sigpending, td->td_sigmask); 2790 2791 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2792 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2793 SIG_STOPSIGMASK(sigpending); 2794 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2795 return (0); 2796 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2797 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2798 SIGISMEMBER(sigpending, SIGSTOP)) { 2799 /* 2800 * If debugger just attached, always consume 2801 * SIGSTOP from ptrace(PT_ATTACH) first, to 2802 * execute the debugger attach ritual in 2803 * order. 2804 */ 2805 sig = SIGSTOP; 2806 td->td_dbgflags |= TDB_FSTP; 2807 } else { 2808 sig = sig_ffs(&sigpending); 2809 } 2810 2811 if (p->p_stops & S_SIG) { 2812 mtx_unlock(&ps->ps_mtx); 2813 stopevent(p, S_SIG, sig); 2814 mtx_lock(&ps->ps_mtx); 2815 } 2816 2817 /* 2818 * We should see pending but ignored signals 2819 * only if P_TRACED was on when they were posted. 2820 */ 2821 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2822 sigqueue_delete(&td->td_sigqueue, sig); 2823 sigqueue_delete(&p->p_sigqueue, sig); 2824 continue; 2825 } 2826 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2827 /* 2828 * If traced, always stop. 2829 * Remove old signal from queue before the stop. 2830 * XXX shrug off debugger, it causes siginfo to 2831 * be thrown away. 2832 */ 2833 queue = &td->td_sigqueue; 2834 ksiginfo_init(&ksi); 2835 if (sigqueue_get(queue, sig, &ksi) == 0) { 2836 queue = &p->p_sigqueue; 2837 sigqueue_get(queue, sig, &ksi); 2838 } 2839 td->td_si = ksi.ksi_info; 2840 2841 mtx_unlock(&ps->ps_mtx); 2842 sig = ptracestop(td, sig, &ksi); 2843 mtx_lock(&ps->ps_mtx); 2844 2845 /* 2846 * Keep looking if the debugger discarded or 2847 * replaced the signal. 2848 */ 2849 if (sig == 0) 2850 continue; 2851 2852 /* 2853 * If the signal became masked, re-queue it. 2854 */ 2855 if (SIGISMEMBER(td->td_sigmask, sig)) { 2856 ksi.ksi_flags |= KSI_HEAD; 2857 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2858 continue; 2859 } 2860 2861 /* 2862 * If the traced bit got turned off, requeue 2863 * the signal and go back up to the top to 2864 * rescan signals. This ensures that p_sig* 2865 * and p_sigact are consistent. 2866 */ 2867 if ((p->p_flag & P_TRACED) == 0) { 2868 ksi.ksi_flags |= KSI_HEAD; 2869 sigqueue_add(queue, sig, &ksi); 2870 continue; 2871 } 2872 } 2873 2874 prop = sigprop(sig); 2875 2876 /* 2877 * Decide whether the signal should be returned. 2878 * Return the signal's number, or fall through 2879 * to clear it from the pending mask. 2880 */ 2881 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2882 2883 case (intptr_t)SIG_DFL: 2884 /* 2885 * Don't take default actions on system processes. 2886 */ 2887 if (p->p_pid <= 1) { 2888 #ifdef DIAGNOSTIC 2889 /* 2890 * Are you sure you want to ignore SIGSEGV 2891 * in init? XXX 2892 */ 2893 printf("Process (pid %lu) got signal %d\n", 2894 (u_long)p->p_pid, sig); 2895 #endif 2896 break; /* == ignore */ 2897 } 2898 /* 2899 * If there is a pending stop signal to process with 2900 * default action, stop here, then clear the signal. 2901 * Traced or exiting processes should ignore stops. 2902 * Additionally, a member of an orphaned process group 2903 * should ignore tty stops. 2904 */ 2905 if (prop & SIGPROP_STOP) { 2906 if (p->p_flag & 2907 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2908 (p->p_pgrp->pg_jobc == 0 && 2909 prop & SIGPROP_TTYSTOP)) 2910 break; /* == ignore */ 2911 if (TD_SBDRY_INTR(td)) { 2912 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2913 ("lost TDF_SBDRY")); 2914 return (-1); 2915 } 2916 mtx_unlock(&ps->ps_mtx); 2917 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2918 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2919 sigqueue_delete(&td->td_sigqueue, sig); 2920 sigqueue_delete(&p->p_sigqueue, sig); 2921 p->p_flag |= P_STOPPED_SIG; 2922 p->p_xsig = sig; 2923 PROC_SLOCK(p); 2924 sig_suspend_threads(td, p, 0); 2925 thread_suspend_switch(td, p); 2926 PROC_SUNLOCK(p); 2927 mtx_lock(&ps->ps_mtx); 2928 goto next; 2929 } else if (prop & SIGPROP_IGNORE) { 2930 /* 2931 * Except for SIGCONT, shouldn't get here. 2932 * Default action is to ignore; drop it. 2933 */ 2934 break; /* == ignore */ 2935 } else 2936 return (sig); 2937 /*NOTREACHED*/ 2938 2939 case (intptr_t)SIG_IGN: 2940 /* 2941 * Masking above should prevent us ever trying 2942 * to take action on an ignored signal other 2943 * than SIGCONT, unless process is traced. 2944 */ 2945 if ((prop & SIGPROP_CONT) == 0 && 2946 (p->p_flag & P_TRACED) == 0) 2947 printf("issignal\n"); 2948 break; /* == ignore */ 2949 2950 default: 2951 /* 2952 * This signal has an action, let 2953 * postsig() process it. 2954 */ 2955 return (sig); 2956 } 2957 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2958 sigqueue_delete(&p->p_sigqueue, sig); 2959 next:; 2960 } 2961 /* NOTREACHED */ 2962 } 2963 2964 void 2965 thread_stopped(struct proc *p) 2966 { 2967 int n; 2968 2969 PROC_LOCK_ASSERT(p, MA_OWNED); 2970 PROC_SLOCK_ASSERT(p, MA_OWNED); 2971 n = p->p_suspcount; 2972 if (p == curproc) 2973 n++; 2974 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2975 PROC_SUNLOCK(p); 2976 p->p_flag &= ~P_WAITED; 2977 PROC_LOCK(p->p_pptr); 2978 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2979 CLD_TRAPPED : CLD_STOPPED); 2980 PROC_UNLOCK(p->p_pptr); 2981 PROC_SLOCK(p); 2982 } 2983 } 2984 2985 /* 2986 * Take the action for the specified signal 2987 * from the current set of pending signals. 2988 */ 2989 int 2990 postsig(int sig) 2991 { 2992 struct thread *td; 2993 struct proc *p; 2994 struct sigacts *ps; 2995 sig_t action; 2996 ksiginfo_t ksi; 2997 sigset_t returnmask; 2998 2999 KASSERT(sig != 0, ("postsig")); 3000 3001 td = curthread; 3002 p = td->td_proc; 3003 PROC_LOCK_ASSERT(p, MA_OWNED); 3004 ps = p->p_sigacts; 3005 mtx_assert(&ps->ps_mtx, MA_OWNED); 3006 ksiginfo_init(&ksi); 3007 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3008 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3009 return (0); 3010 ksi.ksi_signo = sig; 3011 if (ksi.ksi_code == SI_TIMER) 3012 itimer_accept(p, ksi.ksi_timerid, &ksi); 3013 action = ps->ps_sigact[_SIG_IDX(sig)]; 3014 #ifdef KTRACE 3015 if (KTRPOINT(td, KTR_PSIG)) 3016 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3017 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3018 #endif 3019 if ((p->p_stops & S_SIG) != 0) { 3020 mtx_unlock(&ps->ps_mtx); 3021 stopevent(p, S_SIG, sig); 3022 mtx_lock(&ps->ps_mtx); 3023 } 3024 3025 if (action == SIG_DFL) { 3026 /* 3027 * Default action, where the default is to kill 3028 * the process. (Other cases were ignored above.) 3029 */ 3030 mtx_unlock(&ps->ps_mtx); 3031 proc_td_siginfo_capture(td, &ksi.ksi_info); 3032 sigexit(td, sig); 3033 /* NOTREACHED */ 3034 } else { 3035 /* 3036 * If we get here, the signal must be caught. 3037 */ 3038 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3039 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3040 ("postsig action: blocked sig %d", sig)); 3041 3042 /* 3043 * Set the new mask value and also defer further 3044 * occurrences of this signal. 3045 * 3046 * Special case: user has done a sigsuspend. Here the 3047 * current mask is not of interest, but rather the 3048 * mask from before the sigsuspend is what we want 3049 * restored after the signal processing is completed. 3050 */ 3051 if (td->td_pflags & TDP_OLDMASK) { 3052 returnmask = td->td_oldsigmask; 3053 td->td_pflags &= ~TDP_OLDMASK; 3054 } else 3055 returnmask = td->td_sigmask; 3056 3057 if (p->p_sig == sig) { 3058 p->p_code = 0; 3059 p->p_sig = 0; 3060 } 3061 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3062 postsig_done(sig, td, ps); 3063 } 3064 return (1); 3065 } 3066 3067 void 3068 proc_wkilled(struct proc *p) 3069 { 3070 3071 PROC_LOCK_ASSERT(p, MA_OWNED); 3072 if ((p->p_flag & P_WKILLED) == 0) { 3073 p->p_flag |= P_WKILLED; 3074 /* 3075 * Notify swapper that there is a process to swap in. 3076 * The notification is racy, at worst it would take 10 3077 * seconds for the swapper process to notice. 3078 */ 3079 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3080 wakeup(&proc0); 3081 } 3082 } 3083 3084 /* 3085 * Kill the current process for stated reason. 3086 */ 3087 void 3088 killproc(struct proc *p, char *why) 3089 { 3090 3091 PROC_LOCK_ASSERT(p, MA_OWNED); 3092 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3093 p->p_comm); 3094 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3095 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3096 proc_wkilled(p); 3097 kern_psignal(p, SIGKILL); 3098 } 3099 3100 /* 3101 * Force the current process to exit with the specified signal, dumping core 3102 * if appropriate. We bypass the normal tests for masked and caught signals, 3103 * allowing unrecoverable failures to terminate the process without changing 3104 * signal state. Mark the accounting record with the signal termination. 3105 * If dumping core, save the signal number for the debugger. Calls exit and 3106 * does not return. 3107 */ 3108 void 3109 sigexit(struct thread *td, int sig) 3110 { 3111 struct proc *p = td->td_proc; 3112 3113 PROC_LOCK_ASSERT(p, MA_OWNED); 3114 p->p_acflag |= AXSIG; 3115 /* 3116 * We must be single-threading to generate a core dump. This 3117 * ensures that the registers in the core file are up-to-date. 3118 * Also, the ELF dump handler assumes that the thread list doesn't 3119 * change out from under it. 3120 * 3121 * XXX If another thread attempts to single-thread before us 3122 * (e.g. via fork()), we won't get a dump at all. 3123 */ 3124 if ((sigprop(sig) & SIGPROP_CORE) && 3125 thread_single(p, SINGLE_NO_EXIT) == 0) { 3126 p->p_sig = sig; 3127 /* 3128 * Log signals which would cause core dumps 3129 * (Log as LOG_INFO to appease those who don't want 3130 * these messages.) 3131 * XXX : Todo, as well as euid, write out ruid too 3132 * Note that coredump() drops proc lock. 3133 */ 3134 if (coredump(td) == 0) 3135 sig |= WCOREFLAG; 3136 if (kern_logsigexit) 3137 log(LOG_INFO, 3138 "pid %d (%s), uid %d: exited on signal %d%s\n", 3139 p->p_pid, p->p_comm, 3140 td->td_ucred ? td->td_ucred->cr_uid : -1, 3141 sig &~ WCOREFLAG, 3142 sig & WCOREFLAG ? " (core dumped)" : ""); 3143 } else 3144 PROC_UNLOCK(p); 3145 exit1(td, 0, sig); 3146 /* NOTREACHED */ 3147 } 3148 3149 /* 3150 * Send queued SIGCHLD to parent when child process's state 3151 * is changed. 3152 */ 3153 static void 3154 sigparent(struct proc *p, int reason, int status) 3155 { 3156 PROC_LOCK_ASSERT(p, MA_OWNED); 3157 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3158 3159 if (p->p_ksi != NULL) { 3160 p->p_ksi->ksi_signo = SIGCHLD; 3161 p->p_ksi->ksi_code = reason; 3162 p->p_ksi->ksi_status = status; 3163 p->p_ksi->ksi_pid = p->p_pid; 3164 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3165 if (KSI_ONQ(p->p_ksi)) 3166 return; 3167 } 3168 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3169 } 3170 3171 static void 3172 childproc_jobstate(struct proc *p, int reason, int sig) 3173 { 3174 struct sigacts *ps; 3175 3176 PROC_LOCK_ASSERT(p, MA_OWNED); 3177 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3178 3179 /* 3180 * Wake up parent sleeping in kern_wait(), also send 3181 * SIGCHLD to parent, but SIGCHLD does not guarantee 3182 * that parent will awake, because parent may masked 3183 * the signal. 3184 */ 3185 p->p_pptr->p_flag |= P_STATCHILD; 3186 wakeup(p->p_pptr); 3187 3188 ps = p->p_pptr->p_sigacts; 3189 mtx_lock(&ps->ps_mtx); 3190 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3191 mtx_unlock(&ps->ps_mtx); 3192 sigparent(p, reason, sig); 3193 } else 3194 mtx_unlock(&ps->ps_mtx); 3195 } 3196 3197 void 3198 childproc_stopped(struct proc *p, int reason) 3199 { 3200 3201 childproc_jobstate(p, reason, p->p_xsig); 3202 } 3203 3204 void 3205 childproc_continued(struct proc *p) 3206 { 3207 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3208 } 3209 3210 void 3211 childproc_exited(struct proc *p) 3212 { 3213 int reason, status; 3214 3215 if (WCOREDUMP(p->p_xsig)) { 3216 reason = CLD_DUMPED; 3217 status = WTERMSIG(p->p_xsig); 3218 } else if (WIFSIGNALED(p->p_xsig)) { 3219 reason = CLD_KILLED; 3220 status = WTERMSIG(p->p_xsig); 3221 } else { 3222 reason = CLD_EXITED; 3223 status = p->p_xexit; 3224 } 3225 /* 3226 * XXX avoid calling wakeup(p->p_pptr), the work is 3227 * done in exit1(). 3228 */ 3229 sigparent(p, reason, status); 3230 } 3231 3232 #define MAX_NUM_CORE_FILES 100000 3233 #ifndef NUM_CORE_FILES 3234 #define NUM_CORE_FILES 5 3235 #endif 3236 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3237 static int num_cores = NUM_CORE_FILES; 3238 3239 static int 3240 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3241 { 3242 int error; 3243 int new_val; 3244 3245 new_val = num_cores; 3246 error = sysctl_handle_int(oidp, &new_val, 0, req); 3247 if (error != 0 || req->newptr == NULL) 3248 return (error); 3249 if (new_val > MAX_NUM_CORE_FILES) 3250 new_val = MAX_NUM_CORE_FILES; 3251 if (new_val < 0) 3252 new_val = 0; 3253 num_cores = new_val; 3254 return (0); 3255 } 3256 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3257 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3258 "Maximum number of generated process corefiles while using index format"); 3259 3260 #define GZIP_SUFFIX ".gz" 3261 #define ZSTD_SUFFIX ".zst" 3262 3263 int compress_user_cores = 0; 3264 3265 static int 3266 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3267 { 3268 int error, val; 3269 3270 val = compress_user_cores; 3271 error = sysctl_handle_int(oidp, &val, 0, req); 3272 if (error != 0 || req->newptr == NULL) 3273 return (error); 3274 if (val != 0 && !compressor_avail(val)) 3275 return (EINVAL); 3276 compress_user_cores = val; 3277 return (error); 3278 } 3279 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3280 0, sizeof(int), sysctl_compress_user_cores, "I", 3281 "Enable compression of user corefiles (" 3282 __XSTRING(COMPRESS_GZIP) " = gzip, " 3283 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3284 3285 int compress_user_cores_level = 6; 3286 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3287 &compress_user_cores_level, 0, 3288 "Corefile compression level"); 3289 3290 /* 3291 * Protect the access to corefilename[] by allproc_lock. 3292 */ 3293 #define corefilename_lock allproc_lock 3294 3295 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3296 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3297 3298 static int 3299 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3300 { 3301 int error; 3302 3303 sx_xlock(&corefilename_lock); 3304 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3305 req); 3306 sx_xunlock(&corefilename_lock); 3307 3308 return (error); 3309 } 3310 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3311 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3312 "Process corefile name format string"); 3313 3314 static void 3315 vnode_close_locked(struct thread *td, struct vnode *vp) 3316 { 3317 3318 VOP_UNLOCK(vp, 0); 3319 vn_close(vp, FWRITE, td->td_ucred, td); 3320 } 3321 3322 /* 3323 * If the core format has a %I in it, then we need to check 3324 * for existing corefiles before defining a name. 3325 * To do this we iterate over 0..ncores to find a 3326 * non-existing core file name to use. If all core files are 3327 * already used we choose the oldest one. 3328 */ 3329 static int 3330 corefile_open_last(struct thread *td, char *name, int indexpos, 3331 int indexlen, int ncores, struct vnode **vpp) 3332 { 3333 struct vnode *oldvp, *nextvp, *vp; 3334 struct vattr vattr; 3335 struct nameidata nd; 3336 int error, i, flags, oflags, cmode; 3337 char ch; 3338 struct timespec lasttime; 3339 3340 nextvp = oldvp = NULL; 3341 cmode = S_IRUSR | S_IWUSR; 3342 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3343 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3344 3345 for (i = 0; i < ncores; i++) { 3346 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3347 3348 ch = name[indexpos + indexlen]; 3349 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3350 i); 3351 name[indexpos + indexlen] = ch; 3352 3353 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3354 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3355 NULL); 3356 if (error != 0) 3357 break; 3358 3359 vp = nd.ni_vp; 3360 NDFREE(&nd, NDF_ONLY_PNBUF); 3361 if ((flags & O_CREAT) == O_CREAT) { 3362 nextvp = vp; 3363 break; 3364 } 3365 3366 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3367 if (error != 0) { 3368 vnode_close_locked(td, vp); 3369 break; 3370 } 3371 3372 if (oldvp == NULL || 3373 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3374 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3375 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3376 if (oldvp != NULL) 3377 vnode_close_locked(td, oldvp); 3378 oldvp = vp; 3379 lasttime = vattr.va_mtime; 3380 } else { 3381 vnode_close_locked(td, vp); 3382 } 3383 } 3384 3385 if (oldvp != NULL) { 3386 if (nextvp == NULL) 3387 nextvp = oldvp; 3388 else 3389 vnode_close_locked(td, oldvp); 3390 } 3391 if (error != 0) { 3392 if (nextvp != NULL) 3393 vnode_close_locked(td, oldvp); 3394 } else { 3395 *vpp = nextvp; 3396 } 3397 3398 return (error); 3399 } 3400 3401 /* 3402 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3403 * Expand the name described in corefilename, using name, uid, and pid 3404 * and open/create core file. 3405 * corefilename is a printf-like string, with three format specifiers: 3406 * %N name of process ("name") 3407 * %P process id (pid) 3408 * %U user id (uid) 3409 * For example, "%N.core" is the default; they can be disabled completely 3410 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3411 * This is controlled by the sysctl variable kern.corefile (see above). 3412 */ 3413 static int 3414 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3415 int compress, struct vnode **vpp, char **namep) 3416 { 3417 struct sbuf sb; 3418 struct nameidata nd; 3419 const char *format; 3420 char *hostname, *name; 3421 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3422 3423 hostname = NULL; 3424 format = corefilename; 3425 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3426 indexlen = 0; 3427 indexpos = -1; 3428 ncores = num_cores; 3429 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3430 sx_slock(&corefilename_lock); 3431 for (i = 0; format[i] != '\0'; i++) { 3432 switch (format[i]) { 3433 case '%': /* Format character */ 3434 i++; 3435 switch (format[i]) { 3436 case '%': 3437 sbuf_putc(&sb, '%'); 3438 break; 3439 case 'H': /* hostname */ 3440 if (hostname == NULL) { 3441 hostname = malloc(MAXHOSTNAMELEN, 3442 M_TEMP, M_WAITOK); 3443 } 3444 getcredhostname(td->td_ucred, hostname, 3445 MAXHOSTNAMELEN); 3446 sbuf_printf(&sb, "%s", hostname); 3447 break; 3448 case 'I': /* autoincrementing index */ 3449 if (indexpos != -1) { 3450 sbuf_printf(&sb, "%%I"); 3451 break; 3452 } 3453 3454 indexpos = sbuf_len(&sb); 3455 sbuf_printf(&sb, "%u", ncores - 1); 3456 indexlen = sbuf_len(&sb) - indexpos; 3457 break; 3458 case 'N': /* process name */ 3459 sbuf_printf(&sb, "%s", comm); 3460 break; 3461 case 'P': /* process id */ 3462 sbuf_printf(&sb, "%u", pid); 3463 break; 3464 case 'U': /* user id */ 3465 sbuf_printf(&sb, "%u", uid); 3466 break; 3467 default: 3468 log(LOG_ERR, 3469 "Unknown format character %c in " 3470 "corename `%s'\n", format[i], format); 3471 break; 3472 } 3473 break; 3474 default: 3475 sbuf_putc(&sb, format[i]); 3476 break; 3477 } 3478 } 3479 sx_sunlock(&corefilename_lock); 3480 free(hostname, M_TEMP); 3481 if (compress == COMPRESS_GZIP) 3482 sbuf_printf(&sb, GZIP_SUFFIX); 3483 else if (compress == COMPRESS_ZSTD) 3484 sbuf_printf(&sb, ZSTD_SUFFIX); 3485 if (sbuf_error(&sb) != 0) { 3486 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3487 "long\n", (long)pid, comm, (u_long)uid); 3488 sbuf_delete(&sb); 3489 free(name, M_TEMP); 3490 return (ENOMEM); 3491 } 3492 sbuf_finish(&sb); 3493 sbuf_delete(&sb); 3494 3495 if (indexpos != -1) { 3496 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3497 vpp); 3498 if (error != 0) { 3499 log(LOG_ERR, 3500 "pid %d (%s), uid (%u): Path `%s' failed " 3501 "on initial open test, error = %d\n", 3502 pid, comm, uid, name, error); 3503 } 3504 } else { 3505 cmode = S_IRUSR | S_IWUSR; 3506 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3507 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3508 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3509 3510 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3511 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3512 NULL); 3513 if (error == 0) { 3514 *vpp = nd.ni_vp; 3515 NDFREE(&nd, NDF_ONLY_PNBUF); 3516 } 3517 } 3518 3519 if (error != 0) { 3520 #ifdef AUDIT 3521 audit_proc_coredump(td, name, error); 3522 #endif 3523 free(name, M_TEMP); 3524 return (error); 3525 } 3526 *namep = name; 3527 return (0); 3528 } 3529 3530 /* 3531 * Dump a process' core. The main routine does some 3532 * policy checking, and creates the name of the coredump; 3533 * then it passes on a vnode and a size limit to the process-specific 3534 * coredump routine if there is one; if there _is not_ one, it returns 3535 * ENOSYS; otherwise it returns the error from the process-specific routine. 3536 */ 3537 3538 static int 3539 coredump(struct thread *td) 3540 { 3541 struct proc *p = td->td_proc; 3542 struct ucred *cred = td->td_ucred; 3543 struct vnode *vp; 3544 struct flock lf; 3545 struct vattr vattr; 3546 int error, error1, locked; 3547 char *name; /* name of corefile */ 3548 void *rl_cookie; 3549 off_t limit; 3550 char *fullpath, *freepath = NULL; 3551 struct sbuf *sb; 3552 3553 PROC_LOCK_ASSERT(p, MA_OWNED); 3554 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3555 _STOPEVENT(p, S_CORE, 0); 3556 3557 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3558 (p->p_flag2 & P2_NOTRACE) != 0) { 3559 PROC_UNLOCK(p); 3560 return (EFAULT); 3561 } 3562 3563 /* 3564 * Note that the bulk of limit checking is done after 3565 * the corefile is created. The exception is if the limit 3566 * for corefiles is 0, in which case we don't bother 3567 * creating the corefile at all. This layout means that 3568 * a corefile is truncated instead of not being created, 3569 * if it is larger than the limit. 3570 */ 3571 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3572 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3573 PROC_UNLOCK(p); 3574 return (EFBIG); 3575 } 3576 PROC_UNLOCK(p); 3577 3578 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3579 compress_user_cores, &vp, &name); 3580 if (error != 0) 3581 return (error); 3582 3583 /* 3584 * Don't dump to non-regular files or files with links. 3585 * Do not dump into system files. 3586 */ 3587 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3588 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3589 VOP_UNLOCK(vp, 0); 3590 error = EFAULT; 3591 goto out; 3592 } 3593 3594 VOP_UNLOCK(vp, 0); 3595 3596 /* Postpone other writers, including core dumps of other processes. */ 3597 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3598 3599 lf.l_whence = SEEK_SET; 3600 lf.l_start = 0; 3601 lf.l_len = 0; 3602 lf.l_type = F_WRLCK; 3603 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3604 3605 VATTR_NULL(&vattr); 3606 vattr.va_size = 0; 3607 if (set_core_nodump_flag) 3608 vattr.va_flags = UF_NODUMP; 3609 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3610 VOP_SETATTR(vp, &vattr, cred); 3611 VOP_UNLOCK(vp, 0); 3612 PROC_LOCK(p); 3613 p->p_acflag |= ACORE; 3614 PROC_UNLOCK(p); 3615 3616 if (p->p_sysent->sv_coredump != NULL) { 3617 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3618 } else { 3619 error = ENOSYS; 3620 } 3621 3622 if (locked) { 3623 lf.l_type = F_UNLCK; 3624 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3625 } 3626 vn_rangelock_unlock(vp, rl_cookie); 3627 3628 /* 3629 * Notify the userland helper that a process triggered a core dump. 3630 * This allows the helper to run an automated debugging session. 3631 */ 3632 if (error != 0 || coredump_devctl == 0) 3633 goto out; 3634 sb = sbuf_new_auto(); 3635 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3636 goto out2; 3637 sbuf_printf(sb, "comm=\""); 3638 devctl_safe_quote_sb(sb, fullpath); 3639 free(freepath, M_TEMP); 3640 sbuf_printf(sb, "\" core=\""); 3641 3642 /* 3643 * We can't lookup core file vp directly. When we're replacing a core, and 3644 * other random times, we flush the name cache, so it will fail. Instead, 3645 * if the path of the core is relative, add the current dir in front if it. 3646 */ 3647 if (name[0] != '/') { 3648 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3649 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3650 free(fullpath, M_TEMP); 3651 goto out2; 3652 } 3653 devctl_safe_quote_sb(sb, fullpath); 3654 free(fullpath, M_TEMP); 3655 sbuf_putc(sb, '/'); 3656 } 3657 devctl_safe_quote_sb(sb, name); 3658 sbuf_printf(sb, "\""); 3659 if (sbuf_finish(sb) == 0) 3660 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3661 out2: 3662 sbuf_delete(sb); 3663 out: 3664 error1 = vn_close(vp, FWRITE, cred, td); 3665 if (error == 0) 3666 error = error1; 3667 #ifdef AUDIT 3668 audit_proc_coredump(td, name, error); 3669 #endif 3670 free(name, M_TEMP); 3671 return (error); 3672 } 3673 3674 /* 3675 * Nonexistent system call-- signal process (may want to handle it). Flag 3676 * error in case process won't see signal immediately (blocked or ignored). 3677 */ 3678 #ifndef _SYS_SYSPROTO_H_ 3679 struct nosys_args { 3680 int dummy; 3681 }; 3682 #endif 3683 /* ARGSUSED */ 3684 int 3685 nosys(struct thread *td, struct nosys_args *args) 3686 { 3687 struct proc *p; 3688 3689 p = td->td_proc; 3690 3691 PROC_LOCK(p); 3692 tdsignal(td, SIGSYS); 3693 PROC_UNLOCK(p); 3694 if (kern_lognosys == 1 || kern_lognosys == 3) { 3695 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3696 td->td_sa.code); 3697 } 3698 if (kern_lognosys == 2 || kern_lognosys == 3) { 3699 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3700 td->td_sa.code); 3701 } 3702 return (ENOSYS); 3703 } 3704 3705 /* 3706 * Send a SIGIO or SIGURG signal to a process or process group using stored 3707 * credentials rather than those of the current process. 3708 */ 3709 void 3710 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3711 { 3712 ksiginfo_t ksi; 3713 struct sigio *sigio; 3714 3715 ksiginfo_init(&ksi); 3716 ksi.ksi_signo = sig; 3717 ksi.ksi_code = SI_KERNEL; 3718 3719 SIGIO_LOCK(); 3720 sigio = *sigiop; 3721 if (sigio == NULL) { 3722 SIGIO_UNLOCK(); 3723 return; 3724 } 3725 if (sigio->sio_pgid > 0) { 3726 PROC_LOCK(sigio->sio_proc); 3727 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3728 kern_psignal(sigio->sio_proc, sig); 3729 PROC_UNLOCK(sigio->sio_proc); 3730 } else if (sigio->sio_pgid < 0) { 3731 struct proc *p; 3732 3733 PGRP_LOCK(sigio->sio_pgrp); 3734 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3735 PROC_LOCK(p); 3736 if (p->p_state == PRS_NORMAL && 3737 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3738 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3739 kern_psignal(p, sig); 3740 PROC_UNLOCK(p); 3741 } 3742 PGRP_UNLOCK(sigio->sio_pgrp); 3743 } 3744 SIGIO_UNLOCK(); 3745 } 3746 3747 static int 3748 filt_sigattach(struct knote *kn) 3749 { 3750 struct proc *p = curproc; 3751 3752 kn->kn_ptr.p_proc = p; 3753 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3754 3755 knlist_add(p->p_klist, kn, 0); 3756 3757 return (0); 3758 } 3759 3760 static void 3761 filt_sigdetach(struct knote *kn) 3762 { 3763 struct proc *p = kn->kn_ptr.p_proc; 3764 3765 knlist_remove(p->p_klist, kn, 0); 3766 } 3767 3768 /* 3769 * signal knotes are shared with proc knotes, so we apply a mask to 3770 * the hint in order to differentiate them from process hints. This 3771 * could be avoided by using a signal-specific knote list, but probably 3772 * isn't worth the trouble. 3773 */ 3774 static int 3775 filt_signal(struct knote *kn, long hint) 3776 { 3777 3778 if (hint & NOTE_SIGNAL) { 3779 hint &= ~NOTE_SIGNAL; 3780 3781 if (kn->kn_id == hint) 3782 kn->kn_data++; 3783 } 3784 return (kn->kn_data != 0); 3785 } 3786 3787 struct sigacts * 3788 sigacts_alloc(void) 3789 { 3790 struct sigacts *ps; 3791 3792 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3793 refcount_init(&ps->ps_refcnt, 1); 3794 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3795 return (ps); 3796 } 3797 3798 void 3799 sigacts_free(struct sigacts *ps) 3800 { 3801 3802 if (refcount_release(&ps->ps_refcnt) == 0) 3803 return; 3804 mtx_destroy(&ps->ps_mtx); 3805 free(ps, M_SUBPROC); 3806 } 3807 3808 struct sigacts * 3809 sigacts_hold(struct sigacts *ps) 3810 { 3811 3812 refcount_acquire(&ps->ps_refcnt); 3813 return (ps); 3814 } 3815 3816 void 3817 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3818 { 3819 3820 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3821 mtx_lock(&src->ps_mtx); 3822 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3823 mtx_unlock(&src->ps_mtx); 3824 } 3825 3826 int 3827 sigacts_shared(struct sigacts *ps) 3828 { 3829 3830 return (ps->ps_refcnt > 1); 3831 }
Cache object: b094bb1bfd149a71bae05f01d05f51e1
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