1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/lock.h> 61 #include <sys/malloc.h> 62 #include <sys/mutex.h> 63 #include <sys/refcount.h> 64 #include <sys/namei.h> 65 #include <sys/proc.h> 66 #include <sys/procdesc.h> 67 #include <sys/posix4.h> 68 #include <sys/pioctl.h> 69 #include <sys/racct.h> 70 #include <sys/resourcevar.h> 71 #include <sys/sdt.h> 72 #include <sys/sbuf.h> 73 #include <sys/sleepqueue.h> 74 #include <sys/smp.h> 75 #include <sys/stat.h> 76 #include <sys/sx.h> 77 #include <sys/syscallsubr.h> 78 #include <sys/sysctl.h> 79 #include <sys/sysent.h> 80 #include <sys/syslog.h> 81 #include <sys/sysproto.h> 82 #include <sys/timers.h> 83 #include <sys/unistd.h> 84 #include <sys/wait.h> 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/uma.h> 88 89 #include <sys/jail.h> 90 91 #include <machine/cpu.h> 92 93 #include <security/audit/audit.h> 94 95 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE3(proc, , , signal__send, 99 "struct thread *", "struct proc *", "int"); 100 SDT_PROBE_DEFINE2(proc, , , signal__clear, 101 "int", "ksiginfo_t *"); 102 SDT_PROBE_DEFINE3(proc, , , signal__discard, 103 "struct thread *", "struct proc *", "int"); 104 105 static int coredump(struct thread *); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td); 109 static int sigprop(int sig); 110 static void tdsigwakeup(struct thread *, int, sig_t, int); 111 static int sig_suspend_threads(struct thread *, struct proc *, int); 112 static int filt_sigattach(struct knote *kn); 113 static void filt_sigdetach(struct knote *kn); 114 static int filt_signal(struct knote *kn, long hint); 115 static struct thread *sigtd(struct proc *p, int sig, int prop); 116 static void sigqueue_start(void); 117 118 static uma_zone_t ksiginfo_zone = NULL; 119 struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124 }; 125 126 static int kern_logsigexit = 1; 127 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131 static int kern_forcesigexit = 1; 132 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 136 "POSIX real time signal"); 137 138 static int max_pending_per_proc = 128; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 140 &max_pending_per_proc, 0, "Max pending signals per proc"); 141 142 static int preallocate_siginfo = 1024; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 static int kern_lognosys = 0; 155 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 156 "Log invalid syscalls"); 157 158 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160 /* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165 #define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172 static int sugid_coredump; 173 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176 static int capmode_coredump; 177 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180 static int do_coredump = 1; 181 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184 static int set_core_nodump_flag = 0; 185 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188 static int coredump_devctl = 0; 189 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192 /* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197 #define SIGPROP_KILL 0x01 /* terminates process by default */ 198 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 199 #define SIGPROP_STOP 0x04 /* suspend process */ 200 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 201 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 202 #define SIGPROP_CONT 0x20 /* continue if suspended */ 203 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 204 205 static int sigproptbl[NSIG] = { 206 [SIGHUP] = SIGPROP_KILL, 207 [SIGINT] = SIGPROP_KILL, 208 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 209 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGKILL] = SIGPROP_KILL, 215 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGPIPE] = SIGPROP_KILL, 219 [SIGALRM] = SIGPROP_KILL, 220 [SIGTERM] = SIGPROP_KILL, 221 [SIGURG] = SIGPROP_IGNORE, 222 [SIGSTOP] = SIGPROP_STOP, 223 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 224 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 225 [SIGCHLD] = SIGPROP_IGNORE, 226 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 227 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGIO] = SIGPROP_IGNORE, 229 [SIGXCPU] = SIGPROP_KILL, 230 [SIGXFSZ] = SIGPROP_KILL, 231 [SIGVTALRM] = SIGPROP_KILL, 232 [SIGPROF] = SIGPROP_KILL, 233 [SIGWINCH] = SIGPROP_IGNORE, 234 [SIGINFO] = SIGPROP_IGNORE, 235 [SIGUSR1] = SIGPROP_KILL, 236 [SIGUSR2] = SIGPROP_KILL, 237 }; 238 239 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241 static void 242 sigqueue_start(void) 243 { 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250 } 251 252 ksiginfo_t * 253 ksiginfo_alloc(int wait) 254 { 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263 } 264 265 void 266 ksiginfo_free(ksiginfo_t *ksi) 267 { 268 uma_zfree(ksiginfo_zone, ksi); 269 } 270 271 static __inline int 272 ksiginfo_tryfree(ksiginfo_t *ksi) 273 { 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279 } 280 281 void 282 sigqueue_init(sigqueue_t *list, struct proc *p) 283 { 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290 } 291 292 /* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298 static int 299 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300 { 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339 } 340 341 void 342 sigqueue_take(ksiginfo_t *ksi) 343 { 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365 } 366 367 static int 368 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369 { 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432 out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435 } 436 437 void 438 sigqueue_flush(sigqueue_t *sq) 439 { 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458 } 459 460 static void 461 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462 { 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499 } 500 501 #if 0 502 static void 503 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510 } 511 #endif 512 513 static void 514 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515 { 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533 } 534 535 void 536 sigqueue_delete(sigqueue_t *sq, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543 } 544 545 /* Remove a set of signals for a process */ 546 static void 547 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548 { 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561 } 562 563 void 564 sigqueue_delete_proc(struct proc *p, int signo) 565 { 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571 } 572 573 static void 574 sigqueue_delete_stopmask_proc(struct proc *p) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584 } 585 586 /* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591 int 592 cursig(struct thread *td) 593 { 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598 } 599 600 /* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605 void 606 signotify(struct thread *td) 607 { 608 609 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 /* 619 * Returns 1 (true) if altstack is configured for the thread, and the 620 * passed stack bottom address falls into the altstack range. Handles 621 * the 43 compat special case where the alt stack size is zero. 622 */ 623 int 624 sigonstack(size_t sp) 625 { 626 struct thread *td; 627 628 td = curthread; 629 if ((td->td_pflags & TDP_ALTSTACK) == 0) 630 return (0); 631 #if defined(COMPAT_43) 632 if (td->td_sigstk.ss_size == 0) 633 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 634 #endif 635 return (sp >= (size_t)td->td_sigstk.ss_sp && 636 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 637 } 638 639 static __inline int 640 sigprop(int sig) 641 { 642 643 if (sig > 0 && sig < nitems(sigproptbl)) 644 return (sigproptbl[sig]); 645 return (0); 646 } 647 648 int 649 sig_ffs(sigset_t *set) 650 { 651 int i; 652 653 for (i = 0; i < _SIG_WORDS; i++) 654 if (set->__bits[i]) 655 return (ffs(set->__bits[i]) + (i * 32)); 656 return (0); 657 } 658 659 static bool 660 sigact_flag_test(const struct sigaction *act, int flag) 661 { 662 663 /* 664 * SA_SIGINFO is reset when signal disposition is set to 665 * ignore or default. Other flags are kept according to user 666 * settings. 667 */ 668 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 669 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 670 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 671 } 672 673 /* 674 * kern_sigaction 675 * sigaction 676 * freebsd4_sigaction 677 * osigaction 678 */ 679 int 680 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 681 struct sigaction *oact, int flags) 682 { 683 struct sigacts *ps; 684 struct proc *p = td->td_proc; 685 686 if (!_SIG_VALID(sig)) 687 return (EINVAL); 688 if (act != NULL && act->sa_handler != SIG_DFL && 689 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 690 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 691 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 692 return (EINVAL); 693 694 PROC_LOCK(p); 695 ps = p->p_sigacts; 696 mtx_lock(&ps->ps_mtx); 697 if (oact) { 698 memset(oact, 0, sizeof(*oact)); 699 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 700 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 701 oact->sa_flags |= SA_ONSTACK; 702 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 703 oact->sa_flags |= SA_RESTART; 704 if (SIGISMEMBER(ps->ps_sigreset, sig)) 705 oact->sa_flags |= SA_RESETHAND; 706 if (SIGISMEMBER(ps->ps_signodefer, sig)) 707 oact->sa_flags |= SA_NODEFER; 708 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 709 oact->sa_flags |= SA_SIGINFO; 710 oact->sa_sigaction = 711 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 712 } else 713 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 714 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 715 oact->sa_flags |= SA_NOCLDSTOP; 716 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 717 oact->sa_flags |= SA_NOCLDWAIT; 718 } 719 if (act) { 720 if ((sig == SIGKILL || sig == SIGSTOP) && 721 act->sa_handler != SIG_DFL) { 722 mtx_unlock(&ps->ps_mtx); 723 PROC_UNLOCK(p); 724 return (EINVAL); 725 } 726 727 /* 728 * Change setting atomically. 729 */ 730 731 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 732 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 733 if (sigact_flag_test(act, SA_SIGINFO)) { 734 ps->ps_sigact[_SIG_IDX(sig)] = 735 (__sighandler_t *)act->sa_sigaction; 736 SIGADDSET(ps->ps_siginfo, sig); 737 } else { 738 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 739 SIGDELSET(ps->ps_siginfo, sig); 740 } 741 if (!sigact_flag_test(act, SA_RESTART)) 742 SIGADDSET(ps->ps_sigintr, sig); 743 else 744 SIGDELSET(ps->ps_sigintr, sig); 745 if (sigact_flag_test(act, SA_ONSTACK)) 746 SIGADDSET(ps->ps_sigonstack, sig); 747 else 748 SIGDELSET(ps->ps_sigonstack, sig); 749 if (sigact_flag_test(act, SA_RESETHAND)) 750 SIGADDSET(ps->ps_sigreset, sig); 751 else 752 SIGDELSET(ps->ps_sigreset, sig); 753 if (sigact_flag_test(act, SA_NODEFER)) 754 SIGADDSET(ps->ps_signodefer, sig); 755 else 756 SIGDELSET(ps->ps_signodefer, sig); 757 if (sig == SIGCHLD) { 758 if (act->sa_flags & SA_NOCLDSTOP) 759 ps->ps_flag |= PS_NOCLDSTOP; 760 else 761 ps->ps_flag &= ~PS_NOCLDSTOP; 762 if (act->sa_flags & SA_NOCLDWAIT) { 763 /* 764 * Paranoia: since SA_NOCLDWAIT is implemented 765 * by reparenting the dying child to PID 1 (and 766 * trust it to reap the zombie), PID 1 itself 767 * is forbidden to set SA_NOCLDWAIT. 768 */ 769 if (p->p_pid == 1) 770 ps->ps_flag &= ~PS_NOCLDWAIT; 771 else 772 ps->ps_flag |= PS_NOCLDWAIT; 773 } else 774 ps->ps_flag &= ~PS_NOCLDWAIT; 775 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 776 ps->ps_flag |= PS_CLDSIGIGN; 777 else 778 ps->ps_flag &= ~PS_CLDSIGIGN; 779 } 780 /* 781 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 782 * and for signals set to SIG_DFL where the default is to 783 * ignore. However, don't put SIGCONT in ps_sigignore, as we 784 * have to restart the process. 785 */ 786 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 787 (sigprop(sig) & SIGPROP_IGNORE && 788 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 789 /* never to be seen again */ 790 sigqueue_delete_proc(p, sig); 791 if (sig != SIGCONT) 792 /* easier in psignal */ 793 SIGADDSET(ps->ps_sigignore, sig); 794 SIGDELSET(ps->ps_sigcatch, sig); 795 } else { 796 SIGDELSET(ps->ps_sigignore, sig); 797 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 798 SIGDELSET(ps->ps_sigcatch, sig); 799 else 800 SIGADDSET(ps->ps_sigcatch, sig); 801 } 802 #ifdef COMPAT_FREEBSD4 803 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 804 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 805 (flags & KSA_FREEBSD4) == 0) 806 SIGDELSET(ps->ps_freebsd4, sig); 807 else 808 SIGADDSET(ps->ps_freebsd4, sig); 809 #endif 810 #ifdef COMPAT_43 811 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 812 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 813 (flags & KSA_OSIGSET) == 0) 814 SIGDELSET(ps->ps_osigset, sig); 815 else 816 SIGADDSET(ps->ps_osigset, sig); 817 #endif 818 } 819 mtx_unlock(&ps->ps_mtx); 820 PROC_UNLOCK(p); 821 return (0); 822 } 823 824 #ifndef _SYS_SYSPROTO_H_ 825 struct sigaction_args { 826 int sig; 827 struct sigaction *act; 828 struct sigaction *oact; 829 }; 830 #endif 831 int 832 sys_sigaction(struct thread *td, struct sigaction_args *uap) 833 { 834 struct sigaction act, oact; 835 struct sigaction *actp, *oactp; 836 int error; 837 838 actp = (uap->act != NULL) ? &act : NULL; 839 oactp = (uap->oact != NULL) ? &oact : NULL; 840 if (actp) { 841 error = copyin(uap->act, actp, sizeof(act)); 842 if (error) 843 return (error); 844 } 845 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 846 if (oactp && !error) 847 error = copyout(oactp, uap->oact, sizeof(oact)); 848 return (error); 849 } 850 851 #ifdef COMPAT_FREEBSD4 852 #ifndef _SYS_SYSPROTO_H_ 853 struct freebsd4_sigaction_args { 854 int sig; 855 struct sigaction *act; 856 struct sigaction *oact; 857 }; 858 #endif 859 int 860 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 861 { 862 struct sigaction act, oact; 863 struct sigaction *actp, *oactp; 864 int error; 865 866 867 actp = (uap->act != NULL) ? &act : NULL; 868 oactp = (uap->oact != NULL) ? &oact : NULL; 869 if (actp) { 870 error = copyin(uap->act, actp, sizeof(act)); 871 if (error) 872 return (error); 873 } 874 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 875 if (oactp && !error) 876 error = copyout(oactp, uap->oact, sizeof(oact)); 877 return (error); 878 } 879 #endif /* COMAPT_FREEBSD4 */ 880 881 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 882 #ifndef _SYS_SYSPROTO_H_ 883 struct osigaction_args { 884 int signum; 885 struct osigaction *nsa; 886 struct osigaction *osa; 887 }; 888 #endif 889 int 890 osigaction(struct thread *td, struct osigaction_args *uap) 891 { 892 struct osigaction sa; 893 struct sigaction nsa, osa; 894 struct sigaction *nsap, *osap; 895 int error; 896 897 if (uap->signum <= 0 || uap->signum >= ONSIG) 898 return (EINVAL); 899 900 nsap = (uap->nsa != NULL) ? &nsa : NULL; 901 osap = (uap->osa != NULL) ? &osa : NULL; 902 903 if (nsap) { 904 error = copyin(uap->nsa, &sa, sizeof(sa)); 905 if (error) 906 return (error); 907 nsap->sa_handler = sa.sa_handler; 908 nsap->sa_flags = sa.sa_flags; 909 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 910 } 911 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 912 if (osap && !error) { 913 sa.sa_handler = osap->sa_handler; 914 sa.sa_flags = osap->sa_flags; 915 SIG2OSIG(osap->sa_mask, sa.sa_mask); 916 error = copyout(&sa, uap->osa, sizeof(sa)); 917 } 918 return (error); 919 } 920 921 #if !defined(__i386__) 922 /* Avoid replicating the same stub everywhere */ 923 int 924 osigreturn(struct thread *td, struct osigreturn_args *uap) 925 { 926 927 return (nosys(td, (struct nosys_args *)uap)); 928 } 929 #endif 930 #endif /* COMPAT_43 */ 931 932 /* 933 * Initialize signal state for process 0; 934 * set to ignore signals that are ignored by default. 935 */ 936 void 937 siginit(struct proc *p) 938 { 939 int i; 940 struct sigacts *ps; 941 942 PROC_LOCK(p); 943 ps = p->p_sigacts; 944 mtx_lock(&ps->ps_mtx); 945 for (i = 1; i <= NSIG; i++) { 946 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 947 SIGADDSET(ps->ps_sigignore, i); 948 } 949 } 950 mtx_unlock(&ps->ps_mtx); 951 PROC_UNLOCK(p); 952 } 953 954 /* 955 * Reset specified signal to the default disposition. 956 */ 957 static void 958 sigdflt(struct sigacts *ps, int sig) 959 { 960 961 mtx_assert(&ps->ps_mtx, MA_OWNED); 962 SIGDELSET(ps->ps_sigcatch, sig); 963 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 964 SIGADDSET(ps->ps_sigignore, sig); 965 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 966 SIGDELSET(ps->ps_siginfo, sig); 967 } 968 969 /* 970 * Reset signals for an exec of the specified process. 971 */ 972 void 973 execsigs(struct proc *p) 974 { 975 sigset_t osigignore; 976 struct sigacts *ps; 977 int sig; 978 struct thread *td; 979 980 /* 981 * Reset caught signals. Held signals remain held 982 * through td_sigmask (unless they were caught, 983 * and are now ignored by default). 984 */ 985 PROC_LOCK_ASSERT(p, MA_OWNED); 986 ps = p->p_sigacts; 987 mtx_lock(&ps->ps_mtx); 988 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 989 sig = sig_ffs(&ps->ps_sigcatch); 990 sigdflt(ps, sig); 991 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 992 sigqueue_delete_proc(p, sig); 993 } 994 995 /* 996 * As CloudABI processes cannot modify signal handlers, fully 997 * reset all signals to their default behavior. Do ignore 998 * SIGPIPE, as it would otherwise be impossible to recover from 999 * writes to broken pipes and sockets. 1000 */ 1001 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1002 osigignore = ps->ps_sigignore; 1003 while (SIGNOTEMPTY(osigignore)) { 1004 sig = sig_ffs(&osigignore); 1005 SIGDELSET(osigignore, sig); 1006 if (sig != SIGPIPE) 1007 sigdflt(ps, sig); 1008 } 1009 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1010 } 1011 1012 /* 1013 * Reset stack state to the user stack. 1014 * Clear set of signals caught on the signal stack. 1015 */ 1016 td = curthread; 1017 MPASS(td->td_proc == p); 1018 td->td_sigstk.ss_flags = SS_DISABLE; 1019 td->td_sigstk.ss_size = 0; 1020 td->td_sigstk.ss_sp = 0; 1021 td->td_pflags &= ~TDP_ALTSTACK; 1022 /* 1023 * Reset no zombies if child dies flag as Solaris does. 1024 */ 1025 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1026 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1027 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1028 mtx_unlock(&ps->ps_mtx); 1029 } 1030 1031 /* 1032 * kern_sigprocmask() 1033 * 1034 * Manipulate signal mask. 1035 */ 1036 int 1037 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1038 int flags) 1039 { 1040 sigset_t new_block, oset1; 1041 struct proc *p; 1042 int error; 1043 1044 p = td->td_proc; 1045 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1046 PROC_LOCK_ASSERT(p, MA_OWNED); 1047 else 1048 PROC_LOCK(p); 1049 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1050 ? MA_OWNED : MA_NOTOWNED); 1051 if (oset != NULL) 1052 *oset = td->td_sigmask; 1053 1054 error = 0; 1055 if (set != NULL) { 1056 switch (how) { 1057 case SIG_BLOCK: 1058 SIG_CANTMASK(*set); 1059 oset1 = td->td_sigmask; 1060 SIGSETOR(td->td_sigmask, *set); 1061 new_block = td->td_sigmask; 1062 SIGSETNAND(new_block, oset1); 1063 break; 1064 case SIG_UNBLOCK: 1065 SIGSETNAND(td->td_sigmask, *set); 1066 signotify(td); 1067 goto out; 1068 case SIG_SETMASK: 1069 SIG_CANTMASK(*set); 1070 oset1 = td->td_sigmask; 1071 if (flags & SIGPROCMASK_OLD) 1072 SIGSETLO(td->td_sigmask, *set); 1073 else 1074 td->td_sigmask = *set; 1075 new_block = td->td_sigmask; 1076 SIGSETNAND(new_block, oset1); 1077 signotify(td); 1078 break; 1079 default: 1080 error = EINVAL; 1081 goto out; 1082 } 1083 1084 /* 1085 * The new_block set contains signals that were not previously 1086 * blocked, but are blocked now. 1087 * 1088 * In case we block any signal that was not previously blocked 1089 * for td, and process has the signal pending, try to schedule 1090 * signal delivery to some thread that does not block the 1091 * signal, possibly waking it up. 1092 */ 1093 if (p->p_numthreads != 1) 1094 reschedule_signals(p, new_block, flags); 1095 } 1096 1097 out: 1098 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1099 PROC_UNLOCK(p); 1100 return (error); 1101 } 1102 1103 #ifndef _SYS_SYSPROTO_H_ 1104 struct sigprocmask_args { 1105 int how; 1106 const sigset_t *set; 1107 sigset_t *oset; 1108 }; 1109 #endif 1110 int 1111 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1112 { 1113 sigset_t set, oset; 1114 sigset_t *setp, *osetp; 1115 int error; 1116 1117 setp = (uap->set != NULL) ? &set : NULL; 1118 osetp = (uap->oset != NULL) ? &oset : NULL; 1119 if (setp) { 1120 error = copyin(uap->set, setp, sizeof(set)); 1121 if (error) 1122 return (error); 1123 } 1124 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1125 if (osetp && !error) { 1126 error = copyout(osetp, uap->oset, sizeof(oset)); 1127 } 1128 return (error); 1129 } 1130 1131 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1132 #ifndef _SYS_SYSPROTO_H_ 1133 struct osigprocmask_args { 1134 int how; 1135 osigset_t mask; 1136 }; 1137 #endif 1138 int 1139 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1140 { 1141 sigset_t set, oset; 1142 int error; 1143 1144 OSIG2SIG(uap->mask, set); 1145 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1146 SIG2OSIG(oset, td->td_retval[0]); 1147 return (error); 1148 } 1149 #endif /* COMPAT_43 */ 1150 1151 int 1152 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1153 { 1154 ksiginfo_t ksi; 1155 sigset_t set; 1156 int error; 1157 1158 error = copyin(uap->set, &set, sizeof(set)); 1159 if (error) { 1160 td->td_retval[0] = error; 1161 return (0); 1162 } 1163 1164 error = kern_sigtimedwait(td, set, &ksi, NULL); 1165 if (error) { 1166 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1167 error = ERESTART; 1168 if (error == ERESTART) 1169 return (error); 1170 td->td_retval[0] = error; 1171 return (0); 1172 } 1173 1174 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1175 td->td_retval[0] = error; 1176 return (0); 1177 } 1178 1179 int 1180 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1181 { 1182 struct timespec ts; 1183 struct timespec *timeout; 1184 sigset_t set; 1185 ksiginfo_t ksi; 1186 int error; 1187 1188 if (uap->timeout) { 1189 error = copyin(uap->timeout, &ts, sizeof(ts)); 1190 if (error) 1191 return (error); 1192 1193 timeout = &ts; 1194 } else 1195 timeout = NULL; 1196 1197 error = copyin(uap->set, &set, sizeof(set)); 1198 if (error) 1199 return (error); 1200 1201 error = kern_sigtimedwait(td, set, &ksi, timeout); 1202 if (error) 1203 return (error); 1204 1205 if (uap->info) 1206 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1207 1208 if (error == 0) 1209 td->td_retval[0] = ksi.ksi_signo; 1210 return (error); 1211 } 1212 1213 int 1214 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1215 { 1216 ksiginfo_t ksi; 1217 sigset_t set; 1218 int error; 1219 1220 error = copyin(uap->set, &set, sizeof(set)); 1221 if (error) 1222 return (error); 1223 1224 error = kern_sigtimedwait(td, set, &ksi, NULL); 1225 if (error) 1226 return (error); 1227 1228 if (uap->info) 1229 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1230 1231 if (error == 0) 1232 td->td_retval[0] = ksi.ksi_signo; 1233 return (error); 1234 } 1235 1236 static void 1237 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1238 { 1239 struct thread *thr; 1240 1241 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1242 if (thr == td) 1243 thr->td_si = *si; 1244 else 1245 thr->td_si.si_signo = 0; 1246 } 1247 } 1248 1249 int 1250 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1251 struct timespec *timeout) 1252 { 1253 struct sigacts *ps; 1254 sigset_t saved_mask, new_block; 1255 struct proc *p; 1256 int error, sig, timo, timevalid = 0; 1257 struct timespec rts, ets, ts; 1258 struct timeval tv; 1259 1260 p = td->td_proc; 1261 error = 0; 1262 ets.tv_sec = 0; 1263 ets.tv_nsec = 0; 1264 1265 if (timeout != NULL) { 1266 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1267 timevalid = 1; 1268 getnanouptime(&rts); 1269 timespecadd(&rts, timeout, &ets); 1270 } 1271 } 1272 ksiginfo_init(ksi); 1273 /* Some signals can not be waited for. */ 1274 SIG_CANTMASK(waitset); 1275 ps = p->p_sigacts; 1276 PROC_LOCK(p); 1277 saved_mask = td->td_sigmask; 1278 SIGSETNAND(td->td_sigmask, waitset); 1279 for (;;) { 1280 mtx_lock(&ps->ps_mtx); 1281 sig = cursig(td); 1282 mtx_unlock(&ps->ps_mtx); 1283 KASSERT(sig >= 0, ("sig %d", sig)); 1284 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1285 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1286 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1287 error = 0; 1288 break; 1289 } 1290 } 1291 1292 if (error != 0) 1293 break; 1294 1295 /* 1296 * POSIX says this must be checked after looking for pending 1297 * signals. 1298 */ 1299 if (timeout != NULL) { 1300 if (!timevalid) { 1301 error = EINVAL; 1302 break; 1303 } 1304 getnanouptime(&rts); 1305 if (timespeccmp(&rts, &ets, >=)) { 1306 error = EAGAIN; 1307 break; 1308 } 1309 timespecsub(&ets, &rts, &ts); 1310 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1311 timo = tvtohz(&tv); 1312 } else { 1313 timo = 0; 1314 } 1315 1316 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1317 1318 if (timeout != NULL) { 1319 if (error == ERESTART) { 1320 /* Timeout can not be restarted. */ 1321 error = EINTR; 1322 } else if (error == EAGAIN) { 1323 /* We will calculate timeout by ourself. */ 1324 error = 0; 1325 } 1326 } 1327 } 1328 1329 new_block = saved_mask; 1330 SIGSETNAND(new_block, td->td_sigmask); 1331 td->td_sigmask = saved_mask; 1332 /* 1333 * Fewer signals can be delivered to us, reschedule signal 1334 * notification. 1335 */ 1336 if (p->p_numthreads != 1) 1337 reschedule_signals(p, new_block, 0); 1338 1339 if (error == 0) { 1340 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1341 1342 if (ksi->ksi_code == SI_TIMER) 1343 itimer_accept(p, ksi->ksi_timerid, ksi); 1344 1345 #ifdef KTRACE 1346 if (KTRPOINT(td, KTR_PSIG)) { 1347 sig_t action; 1348 1349 mtx_lock(&ps->ps_mtx); 1350 action = ps->ps_sigact[_SIG_IDX(sig)]; 1351 mtx_unlock(&ps->ps_mtx); 1352 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1353 } 1354 #endif 1355 if (sig == SIGKILL) { 1356 proc_td_siginfo_capture(td, &ksi->ksi_info); 1357 sigexit(td, sig); 1358 } 1359 } 1360 PROC_UNLOCK(p); 1361 return (error); 1362 } 1363 1364 #ifndef _SYS_SYSPROTO_H_ 1365 struct sigpending_args { 1366 sigset_t *set; 1367 }; 1368 #endif 1369 int 1370 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1371 { 1372 struct proc *p = td->td_proc; 1373 sigset_t pending; 1374 1375 PROC_LOCK(p); 1376 pending = p->p_sigqueue.sq_signals; 1377 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1378 PROC_UNLOCK(p); 1379 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1380 } 1381 1382 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigpending_args { 1385 int dummy; 1386 }; 1387 #endif 1388 int 1389 osigpending(struct thread *td, struct osigpending_args *uap) 1390 { 1391 struct proc *p = td->td_proc; 1392 sigset_t pending; 1393 1394 PROC_LOCK(p); 1395 pending = p->p_sigqueue.sq_signals; 1396 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1397 PROC_UNLOCK(p); 1398 SIG2OSIG(pending, td->td_retval[0]); 1399 return (0); 1400 } 1401 #endif /* COMPAT_43 */ 1402 1403 #if defined(COMPAT_43) 1404 /* 1405 * Generalized interface signal handler, 4.3-compatible. 1406 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigvec_args { 1409 int signum; 1410 struct sigvec *nsv; 1411 struct sigvec *osv; 1412 }; 1413 #endif 1414 /* ARGSUSED */ 1415 int 1416 osigvec(struct thread *td, struct osigvec_args *uap) 1417 { 1418 struct sigvec vec; 1419 struct sigaction nsa, osa; 1420 struct sigaction *nsap, *osap; 1421 int error; 1422 1423 if (uap->signum <= 0 || uap->signum >= ONSIG) 1424 return (EINVAL); 1425 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1426 osap = (uap->osv != NULL) ? &osa : NULL; 1427 if (nsap) { 1428 error = copyin(uap->nsv, &vec, sizeof(vec)); 1429 if (error) 1430 return (error); 1431 nsap->sa_handler = vec.sv_handler; 1432 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1433 nsap->sa_flags = vec.sv_flags; 1434 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1435 } 1436 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1437 if (osap && !error) { 1438 vec.sv_handler = osap->sa_handler; 1439 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1440 vec.sv_flags = osap->sa_flags; 1441 vec.sv_flags &= ~SA_NOCLDWAIT; 1442 vec.sv_flags ^= SA_RESTART; 1443 error = copyout(&vec, uap->osv, sizeof(vec)); 1444 } 1445 return (error); 1446 } 1447 1448 #ifndef _SYS_SYSPROTO_H_ 1449 struct osigblock_args { 1450 int mask; 1451 }; 1452 #endif 1453 int 1454 osigblock(struct thread *td, struct osigblock_args *uap) 1455 { 1456 sigset_t set, oset; 1457 1458 OSIG2SIG(uap->mask, set); 1459 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1460 SIG2OSIG(oset, td->td_retval[0]); 1461 return (0); 1462 } 1463 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct osigsetmask_args { 1466 int mask; 1467 }; 1468 #endif 1469 int 1470 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1471 { 1472 sigset_t set, oset; 1473 1474 OSIG2SIG(uap->mask, set); 1475 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1476 SIG2OSIG(oset, td->td_retval[0]); 1477 return (0); 1478 } 1479 #endif /* COMPAT_43 */ 1480 1481 /* 1482 * Suspend calling thread until signal, providing mask to be set in the 1483 * meantime. 1484 */ 1485 #ifndef _SYS_SYSPROTO_H_ 1486 struct sigsuspend_args { 1487 const sigset_t *sigmask; 1488 }; 1489 #endif 1490 /* ARGSUSED */ 1491 int 1492 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1493 { 1494 sigset_t mask; 1495 int error; 1496 1497 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1498 if (error) 1499 return (error); 1500 return (kern_sigsuspend(td, mask)); 1501 } 1502 1503 int 1504 kern_sigsuspend(struct thread *td, sigset_t mask) 1505 { 1506 struct proc *p = td->td_proc; 1507 int has_sig, sig; 1508 1509 /* 1510 * When returning from sigsuspend, we want 1511 * the old mask to be restored after the 1512 * signal handler has finished. Thus, we 1513 * save it here and mark the sigacts structure 1514 * to indicate this. 1515 */ 1516 PROC_LOCK(p); 1517 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1518 SIGPROCMASK_PROC_LOCKED); 1519 td->td_pflags |= TDP_OLDMASK; 1520 1521 /* 1522 * Process signals now. Otherwise, we can get spurious wakeup 1523 * due to signal entered process queue, but delivered to other 1524 * thread. But sigsuspend should return only on signal 1525 * delivery. 1526 */ 1527 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1528 for (has_sig = 0; !has_sig;) { 1529 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1530 0) == 0) 1531 /* void */; 1532 thread_suspend_check(0); 1533 mtx_lock(&p->p_sigacts->ps_mtx); 1534 while ((sig = cursig(td)) != 0) { 1535 KASSERT(sig >= 0, ("sig %d", sig)); 1536 has_sig += postsig(sig); 1537 } 1538 mtx_unlock(&p->p_sigacts->ps_mtx); 1539 } 1540 PROC_UNLOCK(p); 1541 td->td_errno = EINTR; 1542 td->td_pflags |= TDP_NERRNO; 1543 return (EJUSTRETURN); 1544 } 1545 1546 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1547 /* 1548 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1549 * convention: libc stub passes mask, not pointer, to save a copyin. 1550 */ 1551 #ifndef _SYS_SYSPROTO_H_ 1552 struct osigsuspend_args { 1553 osigset_t mask; 1554 }; 1555 #endif 1556 /* ARGSUSED */ 1557 int 1558 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1559 { 1560 sigset_t mask; 1561 1562 OSIG2SIG(uap->mask, mask); 1563 return (kern_sigsuspend(td, mask)); 1564 } 1565 #endif /* COMPAT_43 */ 1566 1567 #if defined(COMPAT_43) 1568 #ifndef _SYS_SYSPROTO_H_ 1569 struct osigstack_args { 1570 struct sigstack *nss; 1571 struct sigstack *oss; 1572 }; 1573 #endif 1574 /* ARGSUSED */ 1575 int 1576 osigstack(struct thread *td, struct osigstack_args *uap) 1577 { 1578 struct sigstack nss, oss; 1579 int error = 0; 1580 1581 if (uap->nss != NULL) { 1582 error = copyin(uap->nss, &nss, sizeof(nss)); 1583 if (error) 1584 return (error); 1585 } 1586 oss.ss_sp = td->td_sigstk.ss_sp; 1587 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1588 if (uap->nss != NULL) { 1589 td->td_sigstk.ss_sp = nss.ss_sp; 1590 td->td_sigstk.ss_size = 0; 1591 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1592 td->td_pflags |= TDP_ALTSTACK; 1593 } 1594 if (uap->oss != NULL) 1595 error = copyout(&oss, uap->oss, sizeof(oss)); 1596 1597 return (error); 1598 } 1599 #endif /* COMPAT_43 */ 1600 1601 #ifndef _SYS_SYSPROTO_H_ 1602 struct sigaltstack_args { 1603 stack_t *ss; 1604 stack_t *oss; 1605 }; 1606 #endif 1607 /* ARGSUSED */ 1608 int 1609 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1610 { 1611 stack_t ss, oss; 1612 int error; 1613 1614 if (uap->ss != NULL) { 1615 error = copyin(uap->ss, &ss, sizeof(ss)); 1616 if (error) 1617 return (error); 1618 } 1619 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1620 (uap->oss != NULL) ? &oss : NULL); 1621 if (error) 1622 return (error); 1623 if (uap->oss != NULL) 1624 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1625 return (error); 1626 } 1627 1628 int 1629 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1630 { 1631 struct proc *p = td->td_proc; 1632 int oonstack; 1633 1634 oonstack = sigonstack(cpu_getstack(td)); 1635 1636 if (oss != NULL) { 1637 *oss = td->td_sigstk; 1638 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1639 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1640 } 1641 1642 if (ss != NULL) { 1643 if (oonstack) 1644 return (EPERM); 1645 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1646 return (EINVAL); 1647 if (!(ss->ss_flags & SS_DISABLE)) { 1648 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1649 return (ENOMEM); 1650 1651 td->td_sigstk = *ss; 1652 td->td_pflags |= TDP_ALTSTACK; 1653 } else { 1654 td->td_pflags &= ~TDP_ALTSTACK; 1655 } 1656 } 1657 return (0); 1658 } 1659 1660 /* 1661 * Common code for kill process group/broadcast kill. 1662 * cp is calling process. 1663 */ 1664 static int 1665 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1666 { 1667 struct proc *p; 1668 struct pgrp *pgrp; 1669 int err; 1670 int ret; 1671 1672 ret = ESRCH; 1673 if (all) { 1674 /* 1675 * broadcast 1676 */ 1677 sx_slock(&allproc_lock); 1678 FOREACH_PROC_IN_SYSTEM(p) { 1679 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1680 p == td->td_proc || p->p_state == PRS_NEW) { 1681 continue; 1682 } 1683 PROC_LOCK(p); 1684 err = p_cansignal(td, p, sig); 1685 if (err == 0) { 1686 if (sig) 1687 pksignal(p, sig, ksi); 1688 ret = err; 1689 } 1690 else if (ret == ESRCH) 1691 ret = err; 1692 PROC_UNLOCK(p); 1693 } 1694 sx_sunlock(&allproc_lock); 1695 } else { 1696 sx_slock(&proctree_lock); 1697 if (pgid == 0) { 1698 /* 1699 * zero pgid means send to my process group. 1700 */ 1701 pgrp = td->td_proc->p_pgrp; 1702 PGRP_LOCK(pgrp); 1703 } else { 1704 pgrp = pgfind(pgid); 1705 if (pgrp == NULL) { 1706 sx_sunlock(&proctree_lock); 1707 return (ESRCH); 1708 } 1709 } 1710 sx_sunlock(&proctree_lock); 1711 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1712 PROC_LOCK(p); 1713 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1714 p->p_state == PRS_NEW) { 1715 PROC_UNLOCK(p); 1716 continue; 1717 } 1718 err = p_cansignal(td, p, sig); 1719 if (err == 0) { 1720 if (sig) 1721 pksignal(p, sig, ksi); 1722 ret = err; 1723 } 1724 else if (ret == ESRCH) 1725 ret = err; 1726 PROC_UNLOCK(p); 1727 } 1728 PGRP_UNLOCK(pgrp); 1729 } 1730 return (ret); 1731 } 1732 1733 #ifndef _SYS_SYSPROTO_H_ 1734 struct kill_args { 1735 int pid; 1736 int signum; 1737 }; 1738 #endif 1739 /* ARGSUSED */ 1740 int 1741 sys_kill(struct thread *td, struct kill_args *uap) 1742 { 1743 ksiginfo_t ksi; 1744 struct proc *p; 1745 int error; 1746 1747 /* 1748 * A process in capability mode can send signals only to himself. 1749 * The main rationale behind this is that abort(3) is implemented as 1750 * kill(getpid(), SIGABRT). 1751 */ 1752 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1753 return (ECAPMODE); 1754 1755 AUDIT_ARG_SIGNUM(uap->signum); 1756 AUDIT_ARG_PID(uap->pid); 1757 if ((u_int)uap->signum > _SIG_MAXSIG) 1758 return (EINVAL); 1759 1760 ksiginfo_init(&ksi); 1761 ksi.ksi_signo = uap->signum; 1762 ksi.ksi_code = SI_USER; 1763 ksi.ksi_pid = td->td_proc->p_pid; 1764 ksi.ksi_uid = td->td_ucred->cr_ruid; 1765 1766 if (uap->pid > 0) { 1767 /* kill single process */ 1768 if ((p = pfind_any(uap->pid)) == NULL) 1769 return (ESRCH); 1770 AUDIT_ARG_PROCESS(p); 1771 error = p_cansignal(td, p, uap->signum); 1772 if (error == 0 && uap->signum) 1773 pksignal(p, uap->signum, &ksi); 1774 PROC_UNLOCK(p); 1775 return (error); 1776 } 1777 switch (uap->pid) { 1778 case -1: /* broadcast signal */ 1779 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1780 case 0: /* signal own process group */ 1781 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1782 default: /* negative explicit process group */ 1783 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1784 } 1785 /* NOTREACHED */ 1786 } 1787 1788 int 1789 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1790 { 1791 struct proc *p; 1792 int error; 1793 1794 AUDIT_ARG_SIGNUM(uap->signum); 1795 AUDIT_ARG_FD(uap->fd); 1796 if ((u_int)uap->signum > _SIG_MAXSIG) 1797 return (EINVAL); 1798 1799 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1800 if (error) 1801 return (error); 1802 AUDIT_ARG_PROCESS(p); 1803 error = p_cansignal(td, p, uap->signum); 1804 if (error == 0 && uap->signum) 1805 kern_psignal(p, uap->signum); 1806 PROC_UNLOCK(p); 1807 return (error); 1808 } 1809 1810 #if defined(COMPAT_43) 1811 #ifndef _SYS_SYSPROTO_H_ 1812 struct okillpg_args { 1813 int pgid; 1814 int signum; 1815 }; 1816 #endif 1817 /* ARGSUSED */ 1818 int 1819 okillpg(struct thread *td, struct okillpg_args *uap) 1820 { 1821 ksiginfo_t ksi; 1822 1823 AUDIT_ARG_SIGNUM(uap->signum); 1824 AUDIT_ARG_PID(uap->pgid); 1825 if ((u_int)uap->signum > _SIG_MAXSIG) 1826 return (EINVAL); 1827 1828 ksiginfo_init(&ksi); 1829 ksi.ksi_signo = uap->signum; 1830 ksi.ksi_code = SI_USER; 1831 ksi.ksi_pid = td->td_proc->p_pid; 1832 ksi.ksi_uid = td->td_ucred->cr_ruid; 1833 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1834 } 1835 #endif /* COMPAT_43 */ 1836 1837 #ifndef _SYS_SYSPROTO_H_ 1838 struct sigqueue_args { 1839 pid_t pid; 1840 int signum; 1841 /* union sigval */ void *value; 1842 }; 1843 #endif 1844 int 1845 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1846 { 1847 union sigval sv; 1848 1849 sv.sival_ptr = uap->value; 1850 1851 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1852 } 1853 1854 int 1855 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1856 { 1857 ksiginfo_t ksi; 1858 struct proc *p; 1859 int error; 1860 1861 if ((u_int)signum > _SIG_MAXSIG) 1862 return (EINVAL); 1863 1864 /* 1865 * Specification says sigqueue can only send signal to 1866 * single process. 1867 */ 1868 if (pid <= 0) 1869 return (EINVAL); 1870 1871 if ((p = pfind_any(pid)) == NULL) 1872 return (ESRCH); 1873 error = p_cansignal(td, p, signum); 1874 if (error == 0 && signum != 0) { 1875 ksiginfo_init(&ksi); 1876 ksi.ksi_flags = KSI_SIGQ; 1877 ksi.ksi_signo = signum; 1878 ksi.ksi_code = SI_QUEUE; 1879 ksi.ksi_pid = td->td_proc->p_pid; 1880 ksi.ksi_uid = td->td_ucred->cr_ruid; 1881 ksi.ksi_value = *value; 1882 error = pksignal(p, ksi.ksi_signo, &ksi); 1883 } 1884 PROC_UNLOCK(p); 1885 return (error); 1886 } 1887 1888 /* 1889 * Send a signal to a process group. 1890 */ 1891 void 1892 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1893 { 1894 struct pgrp *pgrp; 1895 1896 if (pgid != 0) { 1897 sx_slock(&proctree_lock); 1898 pgrp = pgfind(pgid); 1899 sx_sunlock(&proctree_lock); 1900 if (pgrp != NULL) { 1901 pgsignal(pgrp, sig, 0, ksi); 1902 PGRP_UNLOCK(pgrp); 1903 } 1904 } 1905 } 1906 1907 /* 1908 * Send a signal to a process group. If checktty is 1, 1909 * limit to members which have a controlling terminal. 1910 */ 1911 void 1912 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1913 { 1914 struct proc *p; 1915 1916 if (pgrp) { 1917 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1918 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1919 PROC_LOCK(p); 1920 if (p->p_state == PRS_NORMAL && 1921 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1922 pksignal(p, sig, ksi); 1923 PROC_UNLOCK(p); 1924 } 1925 } 1926 } 1927 1928 1929 /* 1930 * Recalculate the signal mask and reset the signal disposition after 1931 * usermode frame for delivery is formed. Should be called after 1932 * mach-specific routine, because sysent->sv_sendsig() needs correct 1933 * ps_siginfo and signal mask. 1934 */ 1935 static void 1936 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1937 { 1938 sigset_t mask; 1939 1940 mtx_assert(&ps->ps_mtx, MA_OWNED); 1941 td->td_ru.ru_nsignals++; 1942 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1943 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1944 SIGADDSET(mask, sig); 1945 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1946 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1947 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1948 sigdflt(ps, sig); 1949 } 1950 1951 1952 /* 1953 * Send a signal caused by a trap to the current thread. If it will be 1954 * caught immediately, deliver it with correct code. Otherwise, post it 1955 * normally. 1956 */ 1957 void 1958 trapsignal(struct thread *td, ksiginfo_t *ksi) 1959 { 1960 struct sigacts *ps; 1961 struct proc *p; 1962 int sig; 1963 int code; 1964 1965 p = td->td_proc; 1966 sig = ksi->ksi_signo; 1967 code = ksi->ksi_code; 1968 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1969 1970 PROC_LOCK(p); 1971 ps = p->p_sigacts; 1972 mtx_lock(&ps->ps_mtx); 1973 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1974 !SIGISMEMBER(td->td_sigmask, sig)) { 1975 #ifdef KTRACE 1976 if (KTRPOINT(curthread, KTR_PSIG)) 1977 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1978 &td->td_sigmask, code); 1979 #endif 1980 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1981 ksi, &td->td_sigmask); 1982 postsig_done(sig, td, ps); 1983 mtx_unlock(&ps->ps_mtx); 1984 } else { 1985 /* 1986 * Avoid a possible infinite loop if the thread 1987 * masking the signal or process is ignoring the 1988 * signal. 1989 */ 1990 if (kern_forcesigexit && 1991 (SIGISMEMBER(td->td_sigmask, sig) || 1992 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1993 SIGDELSET(td->td_sigmask, sig); 1994 SIGDELSET(ps->ps_sigcatch, sig); 1995 SIGDELSET(ps->ps_sigignore, sig); 1996 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1997 } 1998 mtx_unlock(&ps->ps_mtx); 1999 p->p_sig = sig; /* XXX to verify code */ 2000 tdsendsignal(p, td, sig, ksi); 2001 } 2002 PROC_UNLOCK(p); 2003 } 2004 2005 static struct thread * 2006 sigtd(struct proc *p, int sig, int prop) 2007 { 2008 struct thread *td, *signal_td; 2009 2010 PROC_LOCK_ASSERT(p, MA_OWNED); 2011 2012 /* 2013 * Check if current thread can handle the signal without 2014 * switching context to another thread. 2015 */ 2016 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2017 return (curthread); 2018 signal_td = NULL; 2019 FOREACH_THREAD_IN_PROC(p, td) { 2020 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2021 signal_td = td; 2022 break; 2023 } 2024 } 2025 if (signal_td == NULL) 2026 signal_td = FIRST_THREAD_IN_PROC(p); 2027 return (signal_td); 2028 } 2029 2030 /* 2031 * Send the signal to the process. If the signal has an action, the action 2032 * is usually performed by the target process rather than the caller; we add 2033 * the signal to the set of pending signals for the process. 2034 * 2035 * Exceptions: 2036 * o When a stop signal is sent to a sleeping process that takes the 2037 * default action, the process is stopped without awakening it. 2038 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2039 * regardless of the signal action (eg, blocked or ignored). 2040 * 2041 * Other ignored signals are discarded immediately. 2042 * 2043 * NB: This function may be entered from the debugger via the "kill" DDB 2044 * command. There is little that can be done to mitigate the possibly messy 2045 * side effects of this unwise possibility. 2046 */ 2047 void 2048 kern_psignal(struct proc *p, int sig) 2049 { 2050 ksiginfo_t ksi; 2051 2052 ksiginfo_init(&ksi); 2053 ksi.ksi_signo = sig; 2054 ksi.ksi_code = SI_KERNEL; 2055 (void) tdsendsignal(p, NULL, sig, &ksi); 2056 } 2057 2058 int 2059 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2060 { 2061 2062 return (tdsendsignal(p, NULL, sig, ksi)); 2063 } 2064 2065 /* Utility function for finding a thread to send signal event to. */ 2066 int 2067 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2068 { 2069 struct thread *td; 2070 2071 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2072 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2073 if (td == NULL) 2074 return (ESRCH); 2075 *ttd = td; 2076 } else { 2077 *ttd = NULL; 2078 PROC_LOCK(p); 2079 } 2080 return (0); 2081 } 2082 2083 void 2084 tdsignal(struct thread *td, int sig) 2085 { 2086 ksiginfo_t ksi; 2087 2088 ksiginfo_init(&ksi); 2089 ksi.ksi_signo = sig; 2090 ksi.ksi_code = SI_KERNEL; 2091 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2092 } 2093 2094 void 2095 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2096 { 2097 2098 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2099 } 2100 2101 int 2102 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2103 { 2104 sig_t action; 2105 sigqueue_t *sigqueue; 2106 int prop; 2107 struct sigacts *ps; 2108 int intrval; 2109 int ret = 0; 2110 int wakeup_swapper; 2111 2112 MPASS(td == NULL || p == td->td_proc); 2113 PROC_LOCK_ASSERT(p, MA_OWNED); 2114 2115 if (!_SIG_VALID(sig)) 2116 panic("%s(): invalid signal %d", __func__, sig); 2117 2118 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2119 2120 /* 2121 * IEEE Std 1003.1-2001: return success when killing a zombie. 2122 */ 2123 if (p->p_state == PRS_ZOMBIE) { 2124 if (ksi && (ksi->ksi_flags & KSI_INS)) 2125 ksiginfo_tryfree(ksi); 2126 return (ret); 2127 } 2128 2129 ps = p->p_sigacts; 2130 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2131 prop = sigprop(sig); 2132 2133 if (td == NULL) { 2134 td = sigtd(p, sig, prop); 2135 sigqueue = &p->p_sigqueue; 2136 } else 2137 sigqueue = &td->td_sigqueue; 2138 2139 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2140 2141 /* 2142 * If the signal is being ignored, 2143 * then we forget about it immediately. 2144 * (Note: we don't set SIGCONT in ps_sigignore, 2145 * and if it is set to SIG_IGN, 2146 * action will be SIG_DFL here.) 2147 */ 2148 mtx_lock(&ps->ps_mtx); 2149 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2150 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2151 2152 mtx_unlock(&ps->ps_mtx); 2153 if (ksi && (ksi->ksi_flags & KSI_INS)) 2154 ksiginfo_tryfree(ksi); 2155 return (ret); 2156 } 2157 if (SIGISMEMBER(td->td_sigmask, sig)) 2158 action = SIG_HOLD; 2159 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2160 action = SIG_CATCH; 2161 else 2162 action = SIG_DFL; 2163 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2164 intrval = EINTR; 2165 else 2166 intrval = ERESTART; 2167 mtx_unlock(&ps->ps_mtx); 2168 2169 if (prop & SIGPROP_CONT) 2170 sigqueue_delete_stopmask_proc(p); 2171 else if (prop & SIGPROP_STOP) { 2172 /* 2173 * If sending a tty stop signal to a member of an orphaned 2174 * process group, discard the signal here if the action 2175 * is default; don't stop the process below if sleeping, 2176 * and don't clear any pending SIGCONT. 2177 */ 2178 if ((prop & SIGPROP_TTYSTOP) && 2179 (p->p_pgrp->pg_jobc == 0) && 2180 (action == SIG_DFL)) { 2181 if (ksi && (ksi->ksi_flags & KSI_INS)) 2182 ksiginfo_tryfree(ksi); 2183 return (ret); 2184 } 2185 sigqueue_delete_proc(p, SIGCONT); 2186 if (p->p_flag & P_CONTINUED) { 2187 p->p_flag &= ~P_CONTINUED; 2188 PROC_LOCK(p->p_pptr); 2189 sigqueue_take(p->p_ksi); 2190 PROC_UNLOCK(p->p_pptr); 2191 } 2192 } 2193 2194 ret = sigqueue_add(sigqueue, sig, ksi); 2195 if (ret != 0) 2196 return (ret); 2197 signotify(td); 2198 /* 2199 * Defer further processing for signals which are held, 2200 * except that stopped processes must be continued by SIGCONT. 2201 */ 2202 if (action == SIG_HOLD && 2203 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2204 return (ret); 2205 2206 /* SIGKILL: Remove procfs STOPEVENTs. */ 2207 if (sig == SIGKILL) { 2208 /* from procfs_ioctl.c: PIOCBIC */ 2209 p->p_stops = 0; 2210 /* from procfs_ioctl.c: PIOCCONT */ 2211 p->p_step = 0; 2212 wakeup(&p->p_step); 2213 } 2214 /* 2215 * Some signals have a process-wide effect and a per-thread 2216 * component. Most processing occurs when the process next 2217 * tries to cross the user boundary, however there are some 2218 * times when processing needs to be done immediately, such as 2219 * waking up threads so that they can cross the user boundary. 2220 * We try to do the per-process part here. 2221 */ 2222 if (P_SHOULDSTOP(p)) { 2223 KASSERT(!(p->p_flag & P_WEXIT), 2224 ("signal to stopped but exiting process")); 2225 if (sig == SIGKILL) { 2226 /* 2227 * If traced process is already stopped, 2228 * then no further action is necessary. 2229 */ 2230 if (p->p_flag & P_TRACED) 2231 goto out; 2232 /* 2233 * SIGKILL sets process running. 2234 * It will die elsewhere. 2235 * All threads must be restarted. 2236 */ 2237 p->p_flag &= ~P_STOPPED_SIG; 2238 goto runfast; 2239 } 2240 2241 if (prop & SIGPROP_CONT) { 2242 /* 2243 * If traced process is already stopped, 2244 * then no further action is necessary. 2245 */ 2246 if (p->p_flag & P_TRACED) 2247 goto out; 2248 /* 2249 * If SIGCONT is default (or ignored), we continue the 2250 * process but don't leave the signal in sigqueue as 2251 * it has no further action. If SIGCONT is held, we 2252 * continue the process and leave the signal in 2253 * sigqueue. If the process catches SIGCONT, let it 2254 * handle the signal itself. If it isn't waiting on 2255 * an event, it goes back to run state. 2256 * Otherwise, process goes back to sleep state. 2257 */ 2258 p->p_flag &= ~P_STOPPED_SIG; 2259 PROC_SLOCK(p); 2260 if (p->p_numthreads == p->p_suspcount) { 2261 PROC_SUNLOCK(p); 2262 p->p_flag |= P_CONTINUED; 2263 p->p_xsig = SIGCONT; 2264 PROC_LOCK(p->p_pptr); 2265 childproc_continued(p); 2266 PROC_UNLOCK(p->p_pptr); 2267 PROC_SLOCK(p); 2268 } 2269 if (action == SIG_DFL) { 2270 thread_unsuspend(p); 2271 PROC_SUNLOCK(p); 2272 sigqueue_delete(sigqueue, sig); 2273 goto out; 2274 } 2275 if (action == SIG_CATCH) { 2276 /* 2277 * The process wants to catch it so it needs 2278 * to run at least one thread, but which one? 2279 */ 2280 PROC_SUNLOCK(p); 2281 goto runfast; 2282 } 2283 /* 2284 * The signal is not ignored or caught. 2285 */ 2286 thread_unsuspend(p); 2287 PROC_SUNLOCK(p); 2288 goto out; 2289 } 2290 2291 if (prop & SIGPROP_STOP) { 2292 /* 2293 * If traced process is already stopped, 2294 * then no further action is necessary. 2295 */ 2296 if (p->p_flag & P_TRACED) 2297 goto out; 2298 /* 2299 * Already stopped, don't need to stop again 2300 * (If we did the shell could get confused). 2301 * Just make sure the signal STOP bit set. 2302 */ 2303 p->p_flag |= P_STOPPED_SIG; 2304 sigqueue_delete(sigqueue, sig); 2305 goto out; 2306 } 2307 2308 /* 2309 * All other kinds of signals: 2310 * If a thread is sleeping interruptibly, simulate a 2311 * wakeup so that when it is continued it will be made 2312 * runnable and can look at the signal. However, don't make 2313 * the PROCESS runnable, leave it stopped. 2314 * It may run a bit until it hits a thread_suspend_check(). 2315 */ 2316 wakeup_swapper = 0; 2317 PROC_SLOCK(p); 2318 thread_lock(td); 2319 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2320 wakeup_swapper = sleepq_abort(td, intrval); 2321 thread_unlock(td); 2322 PROC_SUNLOCK(p); 2323 if (wakeup_swapper) 2324 kick_proc0(); 2325 goto out; 2326 /* 2327 * Mutexes are short lived. Threads waiting on them will 2328 * hit thread_suspend_check() soon. 2329 */ 2330 } else if (p->p_state == PRS_NORMAL) { 2331 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2332 tdsigwakeup(td, sig, action, intrval); 2333 goto out; 2334 } 2335 2336 MPASS(action == SIG_DFL); 2337 2338 if (prop & SIGPROP_STOP) { 2339 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2340 goto out; 2341 p->p_flag |= P_STOPPED_SIG; 2342 p->p_xsig = sig; 2343 PROC_SLOCK(p); 2344 wakeup_swapper = sig_suspend_threads(td, p, 1); 2345 if (p->p_numthreads == p->p_suspcount) { 2346 /* 2347 * only thread sending signal to another 2348 * process can reach here, if thread is sending 2349 * signal to its process, because thread does 2350 * not suspend itself here, p_numthreads 2351 * should never be equal to p_suspcount. 2352 */ 2353 thread_stopped(p); 2354 PROC_SUNLOCK(p); 2355 sigqueue_delete_proc(p, p->p_xsig); 2356 } else 2357 PROC_SUNLOCK(p); 2358 if (wakeup_swapper) 2359 kick_proc0(); 2360 goto out; 2361 } 2362 } else { 2363 /* Not in "NORMAL" state. discard the signal. */ 2364 sigqueue_delete(sigqueue, sig); 2365 goto out; 2366 } 2367 2368 /* 2369 * The process is not stopped so we need to apply the signal to all the 2370 * running threads. 2371 */ 2372 runfast: 2373 tdsigwakeup(td, sig, action, intrval); 2374 PROC_SLOCK(p); 2375 thread_unsuspend(p); 2376 PROC_SUNLOCK(p); 2377 out: 2378 /* If we jump here, proc slock should not be owned. */ 2379 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2380 return (ret); 2381 } 2382 2383 /* 2384 * The force of a signal has been directed against a single 2385 * thread. We need to see what we can do about knocking it 2386 * out of any sleep it may be in etc. 2387 */ 2388 static void 2389 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2390 { 2391 struct proc *p = td->td_proc; 2392 int prop; 2393 int wakeup_swapper; 2394 2395 wakeup_swapper = 0; 2396 PROC_LOCK_ASSERT(p, MA_OWNED); 2397 prop = sigprop(sig); 2398 2399 PROC_SLOCK(p); 2400 thread_lock(td); 2401 /* 2402 * Bring the priority of a thread up if we want it to get 2403 * killed in this lifetime. Be careful to avoid bumping the 2404 * priority of the idle thread, since we still allow to signal 2405 * kernel processes. 2406 */ 2407 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2408 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2409 sched_prio(td, PUSER); 2410 if (TD_ON_SLEEPQ(td)) { 2411 /* 2412 * If thread is sleeping uninterruptibly 2413 * we can't interrupt the sleep... the signal will 2414 * be noticed when the process returns through 2415 * trap() or syscall(). 2416 */ 2417 if ((td->td_flags & TDF_SINTR) == 0) 2418 goto out; 2419 /* 2420 * If SIGCONT is default (or ignored) and process is 2421 * asleep, we are finished; the process should not 2422 * be awakened. 2423 */ 2424 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2425 thread_unlock(td); 2426 PROC_SUNLOCK(p); 2427 sigqueue_delete(&p->p_sigqueue, sig); 2428 /* 2429 * It may be on either list in this state. 2430 * Remove from both for now. 2431 */ 2432 sigqueue_delete(&td->td_sigqueue, sig); 2433 return; 2434 } 2435 2436 /* 2437 * Don't awaken a sleeping thread for SIGSTOP if the 2438 * STOP signal is deferred. 2439 */ 2440 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2441 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2442 goto out; 2443 2444 /* 2445 * Give low priority threads a better chance to run. 2446 */ 2447 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2448 sched_prio(td, PUSER); 2449 2450 wakeup_swapper = sleepq_abort(td, intrval); 2451 } else { 2452 /* 2453 * Other states do nothing with the signal immediately, 2454 * other than kicking ourselves if we are running. 2455 * It will either never be noticed, or noticed very soon. 2456 */ 2457 #ifdef SMP 2458 if (TD_IS_RUNNING(td) && td != curthread) 2459 forward_signal(td); 2460 #endif 2461 } 2462 out: 2463 PROC_SUNLOCK(p); 2464 thread_unlock(td); 2465 if (wakeup_swapper) 2466 kick_proc0(); 2467 } 2468 2469 static int 2470 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2471 { 2472 struct thread *td2; 2473 int wakeup_swapper; 2474 2475 PROC_LOCK_ASSERT(p, MA_OWNED); 2476 PROC_SLOCK_ASSERT(p, MA_OWNED); 2477 MPASS(sending || td == curthread); 2478 2479 wakeup_swapper = 0; 2480 FOREACH_THREAD_IN_PROC(p, td2) { 2481 thread_lock(td2); 2482 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2483 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2484 (td2->td_flags & TDF_SINTR)) { 2485 if (td2->td_flags & TDF_SBDRY) { 2486 /* 2487 * Once a thread is asleep with 2488 * TDF_SBDRY and without TDF_SERESTART 2489 * or TDF_SEINTR set, it should never 2490 * become suspended due to this check. 2491 */ 2492 KASSERT(!TD_IS_SUSPENDED(td2), 2493 ("thread with deferred stops suspended")); 2494 if (TD_SBDRY_INTR(td2)) 2495 wakeup_swapper |= sleepq_abort(td2, 2496 TD_SBDRY_ERRNO(td2)); 2497 } else if (!TD_IS_SUSPENDED(td2)) { 2498 thread_suspend_one(td2); 2499 } 2500 } else if (!TD_IS_SUSPENDED(td2)) { 2501 if (sending || td != td2) 2502 td2->td_flags |= TDF_ASTPENDING; 2503 #ifdef SMP 2504 if (TD_IS_RUNNING(td2) && td2 != td) 2505 forward_signal(td2); 2506 #endif 2507 } 2508 thread_unlock(td2); 2509 } 2510 return (wakeup_swapper); 2511 } 2512 2513 /* 2514 * Stop the process for an event deemed interesting to the debugger. If si is 2515 * non-NULL, this is a signal exchange; the new signal requested by the 2516 * debugger will be returned for handling. If si is NULL, this is some other 2517 * type of interesting event. The debugger may request a signal be delivered in 2518 * that case as well, however it will be deferred until it can be handled. 2519 */ 2520 int 2521 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2522 { 2523 struct proc *p = td->td_proc; 2524 struct thread *td2; 2525 ksiginfo_t ksi; 2526 int prop; 2527 2528 PROC_LOCK_ASSERT(p, MA_OWNED); 2529 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2530 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2531 &p->p_mtx.lock_object, "Stopping for traced signal"); 2532 2533 td->td_xsig = sig; 2534 2535 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2536 td->td_dbgflags |= TDB_XSIG; 2537 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2538 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2539 PROC_SLOCK(p); 2540 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2541 if (P_KILLED(p)) { 2542 /* 2543 * Ensure that, if we've been PT_KILLed, the 2544 * exit status reflects that. Another thread 2545 * may also be in ptracestop(), having just 2546 * received the SIGKILL, but this thread was 2547 * unsuspended first. 2548 */ 2549 td->td_dbgflags &= ~TDB_XSIG; 2550 td->td_xsig = SIGKILL; 2551 p->p_ptevents = 0; 2552 break; 2553 } 2554 if (p->p_flag & P_SINGLE_EXIT && 2555 !(td->td_dbgflags & TDB_EXIT)) { 2556 /* 2557 * Ignore ptrace stops except for thread exit 2558 * events when the process exits. 2559 */ 2560 td->td_dbgflags &= ~TDB_XSIG; 2561 PROC_SUNLOCK(p); 2562 return (0); 2563 } 2564 2565 /* 2566 * Make wait(2) work. Ensure that right after the 2567 * attach, the thread which was decided to become the 2568 * leader of attach gets reported to the waiter. 2569 * Otherwise, just avoid overwriting another thread's 2570 * assignment to p_xthread. If another thread has 2571 * already set p_xthread, the current thread will get 2572 * a chance to report itself upon the next iteration. 2573 */ 2574 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2575 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2576 p->p_xthread == NULL)) { 2577 p->p_xsig = sig; 2578 p->p_xthread = td; 2579 td->td_dbgflags &= ~TDB_FSTP; 2580 p->p_flag2 &= ~P2_PTRACE_FSTP; 2581 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2582 sig_suspend_threads(td, p, 0); 2583 } 2584 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2585 td->td_dbgflags &= ~TDB_STOPATFORK; 2586 } 2587 stopme: 2588 thread_suspend_switch(td, p); 2589 if (p->p_xthread == td) 2590 p->p_xthread = NULL; 2591 if (!(p->p_flag & P_TRACED)) 2592 break; 2593 if (td->td_dbgflags & TDB_SUSPEND) { 2594 if (p->p_flag & P_SINGLE_EXIT) 2595 break; 2596 goto stopme; 2597 } 2598 } 2599 PROC_SUNLOCK(p); 2600 } 2601 2602 if (si != NULL && sig == td->td_xsig) { 2603 /* Parent wants us to take the original signal unchanged. */ 2604 si->ksi_flags |= KSI_HEAD; 2605 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2606 si->ksi_signo = 0; 2607 } else if (td->td_xsig != 0) { 2608 /* 2609 * If parent wants us to take a new signal, then it will leave 2610 * it in td->td_xsig; otherwise we just look for signals again. 2611 */ 2612 ksiginfo_init(&ksi); 2613 ksi.ksi_signo = td->td_xsig; 2614 ksi.ksi_flags |= KSI_PTRACE; 2615 prop = sigprop(td->td_xsig); 2616 td2 = sigtd(p, td->td_xsig, prop); 2617 tdsendsignal(p, td2, td->td_xsig, &ksi); 2618 if (td != td2) 2619 return (0); 2620 } 2621 2622 return (td->td_xsig); 2623 } 2624 2625 static void 2626 reschedule_signals(struct proc *p, sigset_t block, int flags) 2627 { 2628 struct sigacts *ps; 2629 struct thread *td; 2630 int sig; 2631 2632 PROC_LOCK_ASSERT(p, MA_OWNED); 2633 ps = p->p_sigacts; 2634 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2635 MA_OWNED : MA_NOTOWNED); 2636 if (SIGISEMPTY(p->p_siglist)) 2637 return; 2638 SIGSETAND(block, p->p_siglist); 2639 while ((sig = sig_ffs(&block)) != 0) { 2640 SIGDELSET(block, sig); 2641 td = sigtd(p, sig, 0); 2642 signotify(td); 2643 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2644 mtx_lock(&ps->ps_mtx); 2645 if (p->p_flag & P_TRACED || 2646 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2647 !SIGISMEMBER(td->td_sigmask, sig))) 2648 tdsigwakeup(td, sig, SIG_CATCH, 2649 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2650 ERESTART)); 2651 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2652 mtx_unlock(&ps->ps_mtx); 2653 } 2654 } 2655 2656 void 2657 tdsigcleanup(struct thread *td) 2658 { 2659 struct proc *p; 2660 sigset_t unblocked; 2661 2662 p = td->td_proc; 2663 PROC_LOCK_ASSERT(p, MA_OWNED); 2664 2665 sigqueue_flush(&td->td_sigqueue); 2666 if (p->p_numthreads == 1) 2667 return; 2668 2669 /* 2670 * Since we cannot handle signals, notify signal post code 2671 * about this by filling the sigmask. 2672 * 2673 * Also, if needed, wake up thread(s) that do not block the 2674 * same signals as the exiting thread, since the thread might 2675 * have been selected for delivery and woken up. 2676 */ 2677 SIGFILLSET(unblocked); 2678 SIGSETNAND(unblocked, td->td_sigmask); 2679 SIGFILLSET(td->td_sigmask); 2680 reschedule_signals(p, unblocked, 0); 2681 2682 } 2683 2684 static int 2685 sigdeferstop_curr_flags(int cflags) 2686 { 2687 2688 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2689 (cflags & TDF_SBDRY) != 0); 2690 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2691 } 2692 2693 /* 2694 * Defer the delivery of SIGSTOP for the current thread, according to 2695 * the requested mode. Returns previous flags, which must be restored 2696 * by sigallowstop(). 2697 * 2698 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2699 * cleared by the current thread, which allow the lock-less read-only 2700 * accesses below. 2701 */ 2702 int 2703 sigdeferstop_impl(int mode) 2704 { 2705 struct thread *td; 2706 int cflags, nflags; 2707 2708 td = curthread; 2709 cflags = sigdeferstop_curr_flags(td->td_flags); 2710 switch (mode) { 2711 case SIGDEFERSTOP_NOP: 2712 nflags = cflags; 2713 break; 2714 case SIGDEFERSTOP_OFF: 2715 nflags = 0; 2716 break; 2717 case SIGDEFERSTOP_SILENT: 2718 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2719 break; 2720 case SIGDEFERSTOP_EINTR: 2721 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2722 break; 2723 case SIGDEFERSTOP_ERESTART: 2724 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2725 break; 2726 default: 2727 panic("sigdeferstop: invalid mode %x", mode); 2728 break; 2729 } 2730 if (cflags == nflags) 2731 return (SIGDEFERSTOP_VAL_NCHG); 2732 thread_lock(td); 2733 td->td_flags = (td->td_flags & ~cflags) | nflags; 2734 thread_unlock(td); 2735 return (cflags); 2736 } 2737 2738 /* 2739 * Restores the STOP handling mode, typically permitting the delivery 2740 * of SIGSTOP for the current thread. This does not immediately 2741 * suspend if a stop was posted. Instead, the thread will suspend 2742 * either via ast() or a subsequent interruptible sleep. 2743 */ 2744 void 2745 sigallowstop_impl(int prev) 2746 { 2747 struct thread *td; 2748 int cflags; 2749 2750 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2751 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2752 ("sigallowstop: incorrect previous mode %x", prev)); 2753 td = curthread; 2754 cflags = sigdeferstop_curr_flags(td->td_flags); 2755 if (cflags != prev) { 2756 thread_lock(td); 2757 td->td_flags = (td->td_flags & ~cflags) | prev; 2758 thread_unlock(td); 2759 } 2760 } 2761 2762 /* 2763 * If the current process has received a signal (should be caught or cause 2764 * termination, should interrupt current syscall), return the signal number. 2765 * Stop signals with default action are processed immediately, then cleared; 2766 * they aren't returned. This is checked after each entry to the system for 2767 * a syscall or trap (though this can usually be done without calling issignal 2768 * by checking the pending signal masks in cursig.) The normal call 2769 * sequence is 2770 * 2771 * while (sig = cursig(curthread)) 2772 * postsig(sig); 2773 */ 2774 static int 2775 issignal(struct thread *td) 2776 { 2777 struct proc *p; 2778 struct sigacts *ps; 2779 struct sigqueue *queue; 2780 sigset_t sigpending; 2781 ksiginfo_t ksi; 2782 int prop, sig, traced; 2783 2784 p = td->td_proc; 2785 ps = p->p_sigacts; 2786 mtx_assert(&ps->ps_mtx, MA_OWNED); 2787 PROC_LOCK_ASSERT(p, MA_OWNED); 2788 for (;;) { 2789 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2790 2791 sigpending = td->td_sigqueue.sq_signals; 2792 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2793 SIGSETNAND(sigpending, td->td_sigmask); 2794 2795 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2796 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2797 SIG_STOPSIGMASK(sigpending); 2798 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2799 return (0); 2800 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2801 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2802 SIGISMEMBER(sigpending, SIGSTOP)) { 2803 /* 2804 * If debugger just attached, always consume 2805 * SIGSTOP from ptrace(PT_ATTACH) first, to 2806 * execute the debugger attach ritual in 2807 * order. 2808 */ 2809 sig = SIGSTOP; 2810 td->td_dbgflags |= TDB_FSTP; 2811 } else { 2812 sig = sig_ffs(&sigpending); 2813 } 2814 2815 if (p->p_stops & S_SIG) { 2816 mtx_unlock(&ps->ps_mtx); 2817 stopevent(p, S_SIG, sig); 2818 mtx_lock(&ps->ps_mtx); 2819 } 2820 2821 /* 2822 * We should see pending but ignored signals 2823 * only if P_TRACED was on when they were posted. 2824 */ 2825 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2826 sigqueue_delete(&td->td_sigqueue, sig); 2827 sigqueue_delete(&p->p_sigqueue, sig); 2828 continue; 2829 } 2830 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2831 /* 2832 * If traced, always stop. 2833 * Remove old signal from queue before the stop. 2834 * XXX shrug off debugger, it causes siginfo to 2835 * be thrown away. 2836 */ 2837 queue = &td->td_sigqueue; 2838 ksiginfo_init(&ksi); 2839 if (sigqueue_get(queue, sig, &ksi) == 0) { 2840 queue = &p->p_sigqueue; 2841 sigqueue_get(queue, sig, &ksi); 2842 } 2843 td->td_si = ksi.ksi_info; 2844 2845 mtx_unlock(&ps->ps_mtx); 2846 sig = ptracestop(td, sig, &ksi); 2847 mtx_lock(&ps->ps_mtx); 2848 2849 td->td_si.si_signo = 0; 2850 2851 /* 2852 * Keep looking if the debugger discarded or 2853 * replaced the signal. 2854 */ 2855 if (sig == 0) 2856 continue; 2857 2858 /* 2859 * If the signal became masked, re-queue it. 2860 */ 2861 if (SIGISMEMBER(td->td_sigmask, sig)) { 2862 ksi.ksi_flags |= KSI_HEAD; 2863 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2864 continue; 2865 } 2866 2867 /* 2868 * If the traced bit got turned off, requeue 2869 * the signal and go back up to the top to 2870 * rescan signals. This ensures that p_sig* 2871 * and p_sigact are consistent. 2872 */ 2873 if ((p->p_flag & P_TRACED) == 0) { 2874 ksi.ksi_flags |= KSI_HEAD; 2875 sigqueue_add(queue, sig, &ksi); 2876 continue; 2877 } 2878 } 2879 2880 prop = sigprop(sig); 2881 2882 /* 2883 * Decide whether the signal should be returned. 2884 * Return the signal's number, or fall through 2885 * to clear it from the pending mask. 2886 */ 2887 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2888 2889 case (intptr_t)SIG_DFL: 2890 /* 2891 * Don't take default actions on system processes. 2892 */ 2893 if (p->p_pid <= 1) { 2894 #ifdef DIAGNOSTIC 2895 /* 2896 * Are you sure you want to ignore SIGSEGV 2897 * in init? XXX 2898 */ 2899 printf("Process (pid %lu) got signal %d\n", 2900 (u_long)p->p_pid, sig); 2901 #endif 2902 break; /* == ignore */ 2903 } 2904 /* 2905 * If there is a pending stop signal to process with 2906 * default action, stop here, then clear the signal. 2907 * Traced or exiting processes should ignore stops. 2908 * Additionally, a member of an orphaned process group 2909 * should ignore tty stops. 2910 */ 2911 if (prop & SIGPROP_STOP) { 2912 if (p->p_flag & 2913 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2914 (p->p_pgrp->pg_jobc == 0 && 2915 prop & SIGPROP_TTYSTOP)) 2916 break; /* == ignore */ 2917 if (TD_SBDRY_INTR(td)) { 2918 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2919 ("lost TDF_SBDRY")); 2920 return (-1); 2921 } 2922 mtx_unlock(&ps->ps_mtx); 2923 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2924 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2925 sigqueue_delete(&td->td_sigqueue, sig); 2926 sigqueue_delete(&p->p_sigqueue, sig); 2927 p->p_flag |= P_STOPPED_SIG; 2928 p->p_xsig = sig; 2929 PROC_SLOCK(p); 2930 sig_suspend_threads(td, p, 0); 2931 thread_suspend_switch(td, p); 2932 PROC_SUNLOCK(p); 2933 mtx_lock(&ps->ps_mtx); 2934 goto next; 2935 } else if (prop & SIGPROP_IGNORE) { 2936 /* 2937 * Except for SIGCONT, shouldn't get here. 2938 * Default action is to ignore; drop it. 2939 */ 2940 break; /* == ignore */ 2941 } else 2942 return (sig); 2943 /*NOTREACHED*/ 2944 2945 case (intptr_t)SIG_IGN: 2946 /* 2947 * Masking above should prevent us ever trying 2948 * to take action on an ignored signal other 2949 * than SIGCONT, unless process is traced. 2950 */ 2951 if ((prop & SIGPROP_CONT) == 0 && 2952 (p->p_flag & P_TRACED) == 0) 2953 printf("issignal\n"); 2954 break; /* == ignore */ 2955 2956 default: 2957 /* 2958 * This signal has an action, let 2959 * postsig() process it. 2960 */ 2961 return (sig); 2962 } 2963 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2964 sigqueue_delete(&p->p_sigqueue, sig); 2965 next:; 2966 } 2967 /* NOTREACHED */ 2968 } 2969 2970 void 2971 thread_stopped(struct proc *p) 2972 { 2973 int n; 2974 2975 PROC_LOCK_ASSERT(p, MA_OWNED); 2976 PROC_SLOCK_ASSERT(p, MA_OWNED); 2977 n = p->p_suspcount; 2978 if (p == curproc) 2979 n++; 2980 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2981 PROC_SUNLOCK(p); 2982 p->p_flag &= ~P_WAITED; 2983 PROC_LOCK(p->p_pptr); 2984 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2985 CLD_TRAPPED : CLD_STOPPED); 2986 PROC_UNLOCK(p->p_pptr); 2987 PROC_SLOCK(p); 2988 } 2989 } 2990 2991 /* 2992 * Take the action for the specified signal 2993 * from the current set of pending signals. 2994 */ 2995 int 2996 postsig(int sig) 2997 { 2998 struct thread *td; 2999 struct proc *p; 3000 struct sigacts *ps; 3001 sig_t action; 3002 ksiginfo_t ksi; 3003 sigset_t returnmask; 3004 3005 KASSERT(sig != 0, ("postsig")); 3006 3007 td = curthread; 3008 p = td->td_proc; 3009 PROC_LOCK_ASSERT(p, MA_OWNED); 3010 ps = p->p_sigacts; 3011 mtx_assert(&ps->ps_mtx, MA_OWNED); 3012 ksiginfo_init(&ksi); 3013 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3014 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3015 return (0); 3016 ksi.ksi_signo = sig; 3017 if (ksi.ksi_code == SI_TIMER) 3018 itimer_accept(p, ksi.ksi_timerid, &ksi); 3019 action = ps->ps_sigact[_SIG_IDX(sig)]; 3020 #ifdef KTRACE 3021 if (KTRPOINT(td, KTR_PSIG)) 3022 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3023 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3024 #endif 3025 if ((p->p_stops & S_SIG) != 0) { 3026 mtx_unlock(&ps->ps_mtx); 3027 stopevent(p, S_SIG, sig); 3028 mtx_lock(&ps->ps_mtx); 3029 } 3030 3031 if (action == SIG_DFL) { 3032 /* 3033 * Default action, where the default is to kill 3034 * the process. (Other cases were ignored above.) 3035 */ 3036 mtx_unlock(&ps->ps_mtx); 3037 proc_td_siginfo_capture(td, &ksi.ksi_info); 3038 sigexit(td, sig); 3039 /* NOTREACHED */ 3040 } else { 3041 /* 3042 * If we get here, the signal must be caught. 3043 */ 3044 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3045 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3046 ("postsig action: blocked sig %d", sig)); 3047 3048 /* 3049 * Set the new mask value and also defer further 3050 * occurrences of this signal. 3051 * 3052 * Special case: user has done a sigsuspend. Here the 3053 * current mask is not of interest, but rather the 3054 * mask from before the sigsuspend is what we want 3055 * restored after the signal processing is completed. 3056 */ 3057 if (td->td_pflags & TDP_OLDMASK) { 3058 returnmask = td->td_oldsigmask; 3059 td->td_pflags &= ~TDP_OLDMASK; 3060 } else 3061 returnmask = td->td_sigmask; 3062 3063 if (p->p_sig == sig) { 3064 p->p_sig = 0; 3065 } 3066 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3067 postsig_done(sig, td, ps); 3068 } 3069 return (1); 3070 } 3071 3072 void 3073 proc_wkilled(struct proc *p) 3074 { 3075 3076 PROC_LOCK_ASSERT(p, MA_OWNED); 3077 if ((p->p_flag & P_WKILLED) == 0) { 3078 p->p_flag |= P_WKILLED; 3079 /* 3080 * Notify swapper that there is a process to swap in. 3081 * The notification is racy, at worst it would take 10 3082 * seconds for the swapper process to notice. 3083 */ 3084 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3085 wakeup(&proc0); 3086 } 3087 } 3088 3089 /* 3090 * Kill the current process for stated reason. 3091 */ 3092 void 3093 killproc(struct proc *p, char *why) 3094 { 3095 3096 PROC_LOCK_ASSERT(p, MA_OWNED); 3097 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3098 p->p_comm); 3099 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3100 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3101 p->p_ucred->cr_uid, why); 3102 proc_wkilled(p); 3103 kern_psignal(p, SIGKILL); 3104 } 3105 3106 /* 3107 * Force the current process to exit with the specified signal, dumping core 3108 * if appropriate. We bypass the normal tests for masked and caught signals, 3109 * allowing unrecoverable failures to terminate the process without changing 3110 * signal state. Mark the accounting record with the signal termination. 3111 * If dumping core, save the signal number for the debugger. Calls exit and 3112 * does not return. 3113 */ 3114 void 3115 sigexit(struct thread *td, int sig) 3116 { 3117 struct proc *p = td->td_proc; 3118 3119 PROC_LOCK_ASSERT(p, MA_OWNED); 3120 p->p_acflag |= AXSIG; 3121 /* 3122 * We must be single-threading to generate a core dump. This 3123 * ensures that the registers in the core file are up-to-date. 3124 * Also, the ELF dump handler assumes that the thread list doesn't 3125 * change out from under it. 3126 * 3127 * XXX If another thread attempts to single-thread before us 3128 * (e.g. via fork()), we won't get a dump at all. 3129 */ 3130 if ((sigprop(sig) & SIGPROP_CORE) && 3131 thread_single(p, SINGLE_NO_EXIT) == 0) { 3132 p->p_sig = sig; 3133 /* 3134 * Log signals which would cause core dumps 3135 * (Log as LOG_INFO to appease those who don't want 3136 * these messages.) 3137 * XXX : Todo, as well as euid, write out ruid too 3138 * Note that coredump() drops proc lock. 3139 */ 3140 if (coredump(td) == 0) 3141 sig |= WCOREFLAG; 3142 if (kern_logsigexit) 3143 log(LOG_INFO, 3144 "pid %d (%s), jid %d, uid %d: exited on " 3145 "signal %d%s\n", p->p_pid, p->p_comm, 3146 p->p_ucred->cr_prison->pr_id, 3147 td->td_ucred->cr_uid, 3148 sig &~ WCOREFLAG, 3149 sig & WCOREFLAG ? " (core dumped)" : ""); 3150 } else 3151 PROC_UNLOCK(p); 3152 exit1(td, 0, sig); 3153 /* NOTREACHED */ 3154 } 3155 3156 /* 3157 * Send queued SIGCHLD to parent when child process's state 3158 * is changed. 3159 */ 3160 static void 3161 sigparent(struct proc *p, int reason, int status) 3162 { 3163 PROC_LOCK_ASSERT(p, MA_OWNED); 3164 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3165 3166 if (p->p_ksi != NULL) { 3167 p->p_ksi->ksi_signo = SIGCHLD; 3168 p->p_ksi->ksi_code = reason; 3169 p->p_ksi->ksi_status = status; 3170 p->p_ksi->ksi_pid = p->p_pid; 3171 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3172 if (KSI_ONQ(p->p_ksi)) 3173 return; 3174 } 3175 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3176 } 3177 3178 static void 3179 childproc_jobstate(struct proc *p, int reason, int sig) 3180 { 3181 struct sigacts *ps; 3182 3183 PROC_LOCK_ASSERT(p, MA_OWNED); 3184 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3185 3186 /* 3187 * Wake up parent sleeping in kern_wait(), also send 3188 * SIGCHLD to parent, but SIGCHLD does not guarantee 3189 * that parent will awake, because parent may masked 3190 * the signal. 3191 */ 3192 p->p_pptr->p_flag |= P_STATCHILD; 3193 wakeup(p->p_pptr); 3194 3195 ps = p->p_pptr->p_sigacts; 3196 mtx_lock(&ps->ps_mtx); 3197 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3198 mtx_unlock(&ps->ps_mtx); 3199 sigparent(p, reason, sig); 3200 } else 3201 mtx_unlock(&ps->ps_mtx); 3202 } 3203 3204 void 3205 childproc_stopped(struct proc *p, int reason) 3206 { 3207 3208 childproc_jobstate(p, reason, p->p_xsig); 3209 } 3210 3211 void 3212 childproc_continued(struct proc *p) 3213 { 3214 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3215 } 3216 3217 void 3218 childproc_exited(struct proc *p) 3219 { 3220 int reason, status; 3221 3222 if (WCOREDUMP(p->p_xsig)) { 3223 reason = CLD_DUMPED; 3224 status = WTERMSIG(p->p_xsig); 3225 } else if (WIFSIGNALED(p->p_xsig)) { 3226 reason = CLD_KILLED; 3227 status = WTERMSIG(p->p_xsig); 3228 } else { 3229 reason = CLD_EXITED; 3230 status = p->p_xexit; 3231 } 3232 /* 3233 * XXX avoid calling wakeup(p->p_pptr), the work is 3234 * done in exit1(). 3235 */ 3236 sigparent(p, reason, status); 3237 } 3238 3239 #define MAX_NUM_CORE_FILES 100000 3240 #ifndef NUM_CORE_FILES 3241 #define NUM_CORE_FILES 5 3242 #endif 3243 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3244 static int num_cores = NUM_CORE_FILES; 3245 3246 static int 3247 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3248 { 3249 int error; 3250 int new_val; 3251 3252 new_val = num_cores; 3253 error = sysctl_handle_int(oidp, &new_val, 0, req); 3254 if (error != 0 || req->newptr == NULL) 3255 return (error); 3256 if (new_val > MAX_NUM_CORE_FILES) 3257 new_val = MAX_NUM_CORE_FILES; 3258 if (new_val < 0) 3259 new_val = 0; 3260 num_cores = new_val; 3261 return (0); 3262 } 3263 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3264 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3265 "Maximum number of generated process corefiles while using index format"); 3266 3267 #define GZIP_SUFFIX ".gz" 3268 #define ZSTD_SUFFIX ".zst" 3269 3270 int compress_user_cores = 0; 3271 3272 static int 3273 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3274 { 3275 int error, val; 3276 3277 val = compress_user_cores; 3278 error = sysctl_handle_int(oidp, &val, 0, req); 3279 if (error != 0 || req->newptr == NULL) 3280 return (error); 3281 if (val != 0 && !compressor_avail(val)) 3282 return (EINVAL); 3283 compress_user_cores = val; 3284 return (error); 3285 } 3286 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3287 0, sizeof(int), sysctl_compress_user_cores, "I", 3288 "Enable compression of user corefiles (" 3289 __XSTRING(COMPRESS_GZIP) " = gzip, " 3290 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3291 3292 int compress_user_cores_level = 6; 3293 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3294 &compress_user_cores_level, 0, 3295 "Corefile compression level"); 3296 3297 /* 3298 * Protect the access to corefilename[] by allproc_lock. 3299 */ 3300 #define corefilename_lock allproc_lock 3301 3302 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3303 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3304 3305 static int 3306 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3307 { 3308 int error; 3309 3310 sx_xlock(&corefilename_lock); 3311 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3312 req); 3313 sx_xunlock(&corefilename_lock); 3314 3315 return (error); 3316 } 3317 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3318 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3319 "Process corefile name format string"); 3320 3321 static void 3322 vnode_close_locked(struct thread *td, struct vnode *vp) 3323 { 3324 3325 VOP_UNLOCK(vp, 0); 3326 vn_close(vp, FWRITE, td->td_ucred, td); 3327 } 3328 3329 /* 3330 * If the core format has a %I in it, then we need to check 3331 * for existing corefiles before defining a name. 3332 * To do this we iterate over 0..ncores to find a 3333 * non-existing core file name to use. If all core files are 3334 * already used we choose the oldest one. 3335 */ 3336 static int 3337 corefile_open_last(struct thread *td, char *name, int indexpos, 3338 int indexlen, int ncores, struct vnode **vpp) 3339 { 3340 struct vnode *oldvp, *nextvp, *vp; 3341 struct vattr vattr; 3342 struct nameidata nd; 3343 int error, i, flags, oflags, cmode; 3344 char ch; 3345 struct timespec lasttime; 3346 3347 nextvp = oldvp = NULL; 3348 cmode = S_IRUSR | S_IWUSR; 3349 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3350 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3351 3352 for (i = 0; i < ncores; i++) { 3353 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3354 3355 ch = name[indexpos + indexlen]; 3356 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3357 i); 3358 name[indexpos + indexlen] = ch; 3359 3360 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3361 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3362 NULL); 3363 if (error != 0) 3364 break; 3365 3366 vp = nd.ni_vp; 3367 NDFREE(&nd, NDF_ONLY_PNBUF); 3368 if ((flags & O_CREAT) == O_CREAT) { 3369 nextvp = vp; 3370 break; 3371 } 3372 3373 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3374 if (error != 0) { 3375 vnode_close_locked(td, vp); 3376 break; 3377 } 3378 3379 if (oldvp == NULL || 3380 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3381 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3382 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3383 if (oldvp != NULL) 3384 vnode_close_locked(td, oldvp); 3385 oldvp = vp; 3386 lasttime = vattr.va_mtime; 3387 } else { 3388 vnode_close_locked(td, vp); 3389 } 3390 } 3391 3392 if (oldvp != NULL) { 3393 if (nextvp == NULL) 3394 nextvp = oldvp; 3395 else 3396 vnode_close_locked(td, oldvp); 3397 } 3398 if (error != 0) { 3399 if (nextvp != NULL) 3400 vnode_close_locked(td, oldvp); 3401 } else { 3402 *vpp = nextvp; 3403 } 3404 3405 return (error); 3406 } 3407 3408 /* 3409 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3410 * Expand the name described in corefilename, using name, uid, and pid 3411 * and open/create core file. 3412 * corefilename is a printf-like string, with three format specifiers: 3413 * %N name of process ("name") 3414 * %P process id (pid) 3415 * %U user id (uid) 3416 * For example, "%N.core" is the default; they can be disabled completely 3417 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3418 * This is controlled by the sysctl variable kern.corefile (see above). 3419 */ 3420 static int 3421 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3422 int compress, struct vnode **vpp, char **namep) 3423 { 3424 struct sbuf sb; 3425 struct nameidata nd; 3426 const char *format; 3427 char *hostname, *name; 3428 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3429 3430 hostname = NULL; 3431 format = corefilename; 3432 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3433 indexlen = 0; 3434 indexpos = -1; 3435 ncores = num_cores; 3436 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3437 sx_slock(&corefilename_lock); 3438 for (i = 0; format[i] != '\0'; i++) { 3439 switch (format[i]) { 3440 case '%': /* Format character */ 3441 i++; 3442 switch (format[i]) { 3443 case '%': 3444 sbuf_putc(&sb, '%'); 3445 break; 3446 case 'H': /* hostname */ 3447 if (hostname == NULL) { 3448 hostname = malloc(MAXHOSTNAMELEN, 3449 M_TEMP, M_WAITOK); 3450 } 3451 getcredhostname(td->td_ucred, hostname, 3452 MAXHOSTNAMELEN); 3453 sbuf_printf(&sb, "%s", hostname); 3454 break; 3455 case 'I': /* autoincrementing index */ 3456 if (indexpos != -1) { 3457 sbuf_printf(&sb, "%%I"); 3458 break; 3459 } 3460 3461 indexpos = sbuf_len(&sb); 3462 sbuf_printf(&sb, "%u", ncores - 1); 3463 indexlen = sbuf_len(&sb) - indexpos; 3464 break; 3465 case 'N': /* process name */ 3466 sbuf_printf(&sb, "%s", comm); 3467 break; 3468 case 'P': /* process id */ 3469 sbuf_printf(&sb, "%u", pid); 3470 break; 3471 case 'U': /* user id */ 3472 sbuf_printf(&sb, "%u", uid); 3473 break; 3474 default: 3475 log(LOG_ERR, 3476 "Unknown format character %c in " 3477 "corename `%s'\n", format[i], format); 3478 break; 3479 } 3480 break; 3481 default: 3482 sbuf_putc(&sb, format[i]); 3483 break; 3484 } 3485 } 3486 sx_sunlock(&corefilename_lock); 3487 free(hostname, M_TEMP); 3488 if (compress == COMPRESS_GZIP) 3489 sbuf_printf(&sb, GZIP_SUFFIX); 3490 else if (compress == COMPRESS_ZSTD) 3491 sbuf_printf(&sb, ZSTD_SUFFIX); 3492 if (sbuf_error(&sb) != 0) { 3493 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3494 "long\n", (long)pid, comm, (u_long)uid); 3495 sbuf_delete(&sb); 3496 free(name, M_TEMP); 3497 return (ENOMEM); 3498 } 3499 sbuf_finish(&sb); 3500 sbuf_delete(&sb); 3501 3502 if (indexpos != -1) { 3503 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3504 vpp); 3505 if (error != 0) { 3506 log(LOG_ERR, 3507 "pid %d (%s), uid (%u): Path `%s' failed " 3508 "on initial open test, error = %d\n", 3509 pid, comm, uid, name, error); 3510 } 3511 } else { 3512 cmode = S_IRUSR | S_IWUSR; 3513 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3514 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3515 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3516 3517 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3518 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3519 NULL); 3520 if (error == 0) { 3521 *vpp = nd.ni_vp; 3522 NDFREE(&nd, NDF_ONLY_PNBUF); 3523 } 3524 } 3525 3526 if (error != 0) { 3527 #ifdef AUDIT 3528 audit_proc_coredump(td, name, error); 3529 #endif 3530 free(name, M_TEMP); 3531 return (error); 3532 } 3533 *namep = name; 3534 return (0); 3535 } 3536 3537 /* 3538 * Dump a process' core. The main routine does some 3539 * policy checking, and creates the name of the coredump; 3540 * then it passes on a vnode and a size limit to the process-specific 3541 * coredump routine if there is one; if there _is not_ one, it returns 3542 * ENOSYS; otherwise it returns the error from the process-specific routine. 3543 */ 3544 3545 static int 3546 coredump(struct thread *td) 3547 { 3548 struct proc *p = td->td_proc; 3549 struct ucred *cred = td->td_ucred; 3550 struct vnode *vp; 3551 struct flock lf; 3552 struct vattr vattr; 3553 int error, error1, locked; 3554 char *name; /* name of corefile */ 3555 void *rl_cookie; 3556 off_t limit; 3557 char *fullpath, *freepath = NULL; 3558 struct sbuf *sb; 3559 3560 PROC_LOCK_ASSERT(p, MA_OWNED); 3561 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3562 _STOPEVENT(p, S_CORE, 0); 3563 3564 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3565 (p->p_flag2 & P2_NOTRACE) != 0) { 3566 PROC_UNLOCK(p); 3567 return (EFAULT); 3568 } 3569 3570 /* 3571 * Note that the bulk of limit checking is done after 3572 * the corefile is created. The exception is if the limit 3573 * for corefiles is 0, in which case we don't bother 3574 * creating the corefile at all. This layout means that 3575 * a corefile is truncated instead of not being created, 3576 * if it is larger than the limit. 3577 */ 3578 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3579 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3580 PROC_UNLOCK(p); 3581 return (EFBIG); 3582 } 3583 PROC_UNLOCK(p); 3584 3585 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3586 compress_user_cores, &vp, &name); 3587 if (error != 0) 3588 return (error); 3589 3590 /* 3591 * Don't dump to non-regular files or files with links. 3592 * Do not dump into system files. 3593 */ 3594 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3595 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3596 VOP_UNLOCK(vp, 0); 3597 error = EFAULT; 3598 goto out; 3599 } 3600 3601 VOP_UNLOCK(vp, 0); 3602 3603 /* Postpone other writers, including core dumps of other processes. */ 3604 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3605 3606 lf.l_whence = SEEK_SET; 3607 lf.l_start = 0; 3608 lf.l_len = 0; 3609 lf.l_type = F_WRLCK; 3610 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3611 3612 VATTR_NULL(&vattr); 3613 vattr.va_size = 0; 3614 if (set_core_nodump_flag) 3615 vattr.va_flags = UF_NODUMP; 3616 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3617 VOP_SETATTR(vp, &vattr, cred); 3618 VOP_UNLOCK(vp, 0); 3619 PROC_LOCK(p); 3620 p->p_acflag |= ACORE; 3621 PROC_UNLOCK(p); 3622 3623 if (p->p_sysent->sv_coredump != NULL) { 3624 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3625 } else { 3626 error = ENOSYS; 3627 } 3628 3629 if (locked) { 3630 lf.l_type = F_UNLCK; 3631 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3632 } 3633 vn_rangelock_unlock(vp, rl_cookie); 3634 3635 /* 3636 * Notify the userland helper that a process triggered a core dump. 3637 * This allows the helper to run an automated debugging session. 3638 */ 3639 if (error != 0 || coredump_devctl == 0) 3640 goto out; 3641 sb = sbuf_new_auto(); 3642 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3643 goto out2; 3644 sbuf_printf(sb, "comm=\""); 3645 devctl_safe_quote_sb(sb, fullpath); 3646 free(freepath, M_TEMP); 3647 sbuf_printf(sb, "\" core=\""); 3648 3649 /* 3650 * We can't lookup core file vp directly. When we're replacing a core, and 3651 * other random times, we flush the name cache, so it will fail. Instead, 3652 * if the path of the core is relative, add the current dir in front if it. 3653 */ 3654 if (name[0] != '/') { 3655 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3656 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3657 free(fullpath, M_TEMP); 3658 goto out2; 3659 } 3660 devctl_safe_quote_sb(sb, fullpath); 3661 free(fullpath, M_TEMP); 3662 sbuf_putc(sb, '/'); 3663 } 3664 devctl_safe_quote_sb(sb, name); 3665 sbuf_printf(sb, "\""); 3666 if (sbuf_finish(sb) == 0) 3667 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3668 out2: 3669 sbuf_delete(sb); 3670 out: 3671 error1 = vn_close(vp, FWRITE, cred, td); 3672 if (error == 0) 3673 error = error1; 3674 #ifdef AUDIT 3675 audit_proc_coredump(td, name, error); 3676 #endif 3677 free(name, M_TEMP); 3678 return (error); 3679 } 3680 3681 /* 3682 * Nonexistent system call-- signal process (may want to handle it). Flag 3683 * error in case process won't see signal immediately (blocked or ignored). 3684 */ 3685 #ifndef _SYS_SYSPROTO_H_ 3686 struct nosys_args { 3687 int dummy; 3688 }; 3689 #endif 3690 /* ARGSUSED */ 3691 int 3692 nosys(struct thread *td, struct nosys_args *args) 3693 { 3694 struct proc *p; 3695 3696 p = td->td_proc; 3697 3698 PROC_LOCK(p); 3699 tdsignal(td, SIGSYS); 3700 PROC_UNLOCK(p); 3701 if (kern_lognosys == 1 || kern_lognosys == 3) { 3702 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3703 td->td_sa.code); 3704 } 3705 if (kern_lognosys == 2 || kern_lognosys == 3) { 3706 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3707 td->td_sa.code); 3708 } 3709 return (ENOSYS); 3710 } 3711 3712 /* 3713 * Send a SIGIO or SIGURG signal to a process or process group using stored 3714 * credentials rather than those of the current process. 3715 */ 3716 void 3717 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3718 { 3719 ksiginfo_t ksi; 3720 struct sigio *sigio; 3721 3722 ksiginfo_init(&ksi); 3723 ksi.ksi_signo = sig; 3724 ksi.ksi_code = SI_KERNEL; 3725 3726 SIGIO_LOCK(); 3727 sigio = *sigiop; 3728 if (sigio == NULL) { 3729 SIGIO_UNLOCK(); 3730 return; 3731 } 3732 if (sigio->sio_pgid > 0) { 3733 PROC_LOCK(sigio->sio_proc); 3734 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3735 kern_psignal(sigio->sio_proc, sig); 3736 PROC_UNLOCK(sigio->sio_proc); 3737 } else if (sigio->sio_pgid < 0) { 3738 struct proc *p; 3739 3740 PGRP_LOCK(sigio->sio_pgrp); 3741 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3742 PROC_LOCK(p); 3743 if (p->p_state == PRS_NORMAL && 3744 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3745 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3746 kern_psignal(p, sig); 3747 PROC_UNLOCK(p); 3748 } 3749 PGRP_UNLOCK(sigio->sio_pgrp); 3750 } 3751 SIGIO_UNLOCK(); 3752 } 3753 3754 static int 3755 filt_sigattach(struct knote *kn) 3756 { 3757 struct proc *p = curproc; 3758 3759 kn->kn_ptr.p_proc = p; 3760 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3761 3762 knlist_add(p->p_klist, kn, 0); 3763 3764 return (0); 3765 } 3766 3767 static void 3768 filt_sigdetach(struct knote *kn) 3769 { 3770 struct proc *p = kn->kn_ptr.p_proc; 3771 3772 knlist_remove(p->p_klist, kn, 0); 3773 } 3774 3775 /* 3776 * signal knotes are shared with proc knotes, so we apply a mask to 3777 * the hint in order to differentiate them from process hints. This 3778 * could be avoided by using a signal-specific knote list, but probably 3779 * isn't worth the trouble. 3780 */ 3781 static int 3782 filt_signal(struct knote *kn, long hint) 3783 { 3784 3785 if (hint & NOTE_SIGNAL) { 3786 hint &= ~NOTE_SIGNAL; 3787 3788 if (kn->kn_id == hint) 3789 kn->kn_data++; 3790 } 3791 return (kn->kn_data != 0); 3792 } 3793 3794 struct sigacts * 3795 sigacts_alloc(void) 3796 { 3797 struct sigacts *ps; 3798 3799 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3800 refcount_init(&ps->ps_refcnt, 1); 3801 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3802 return (ps); 3803 } 3804 3805 void 3806 sigacts_free(struct sigacts *ps) 3807 { 3808 3809 if (refcount_release(&ps->ps_refcnt) == 0) 3810 return; 3811 mtx_destroy(&ps->ps_mtx); 3812 free(ps, M_SUBPROC); 3813 } 3814 3815 struct sigacts * 3816 sigacts_hold(struct sigacts *ps) 3817 { 3818 3819 refcount_acquire(&ps->ps_refcnt); 3820 return (ps); 3821 } 3822 3823 void 3824 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3825 { 3826 3827 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3828 mtx_lock(&src->ps_mtx); 3829 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3830 mtx_unlock(&src->ps_mtx); 3831 } 3832 3833 int 3834 sigacts_shared(struct sigacts *ps) 3835 { 3836 3837 return (ps->ps_refcnt > 1); 3838 } 3839