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 /* Would this signal be fatal to the current process, if it were caught ? */ 933 bool 934 sig_isfatal(struct proc *p, int sig) 935 { 936 intptr_t act; 937 int prop; 938 939 mtx_assert(&p->p_sigacts->ps_mtx, MA_OWNED); 940 act = (intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]; 941 if ((intptr_t)SIG_DFL == act) { 942 prop = sigprop(sig); 943 return (0 != (prop & (SIGPROP_KILL | SIGPROP_CORE))); 944 } else { 945 return (false); 946 } 947 } 948 949 /* 950 * Initialize signal state for process 0; 951 * set to ignore signals that are ignored by default. 952 */ 953 void 954 siginit(struct proc *p) 955 { 956 int i; 957 struct sigacts *ps; 958 959 PROC_LOCK(p); 960 ps = p->p_sigacts; 961 mtx_lock(&ps->ps_mtx); 962 for (i = 1; i <= NSIG; i++) { 963 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 964 SIGADDSET(ps->ps_sigignore, i); 965 } 966 } 967 mtx_unlock(&ps->ps_mtx); 968 PROC_UNLOCK(p); 969 } 970 971 /* 972 * Reset specified signal to the default disposition. 973 */ 974 static void 975 sigdflt(struct sigacts *ps, int sig) 976 { 977 978 mtx_assert(&ps->ps_mtx, MA_OWNED); 979 SIGDELSET(ps->ps_sigcatch, sig); 980 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 981 SIGADDSET(ps->ps_sigignore, sig); 982 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 983 SIGDELSET(ps->ps_siginfo, sig); 984 } 985 986 /* 987 * Reset signals for an exec of the specified process. 988 */ 989 void 990 execsigs(struct proc *p) 991 { 992 sigset_t osigignore; 993 struct sigacts *ps; 994 int sig; 995 struct thread *td; 996 997 /* 998 * Reset caught signals. Held signals remain held 999 * through td_sigmask (unless they were caught, 1000 * and are now ignored by default). 1001 */ 1002 PROC_LOCK_ASSERT(p, MA_OWNED); 1003 ps = p->p_sigacts; 1004 mtx_lock(&ps->ps_mtx); 1005 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 1006 sig = sig_ffs(&ps->ps_sigcatch); 1007 sigdflt(ps, sig); 1008 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 1009 sigqueue_delete_proc(p, sig); 1010 } 1011 1012 /* 1013 * As CloudABI processes cannot modify signal handlers, fully 1014 * reset all signals to their default behavior. Do ignore 1015 * SIGPIPE, as it would otherwise be impossible to recover from 1016 * writes to broken pipes and sockets. 1017 */ 1018 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1019 osigignore = ps->ps_sigignore; 1020 while (SIGNOTEMPTY(osigignore)) { 1021 sig = sig_ffs(&osigignore); 1022 SIGDELSET(osigignore, sig); 1023 if (sig != SIGPIPE) 1024 sigdflt(ps, sig); 1025 } 1026 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1027 } 1028 1029 /* 1030 * Reset stack state to the user stack. 1031 * Clear set of signals caught on the signal stack. 1032 */ 1033 td = curthread; 1034 MPASS(td->td_proc == p); 1035 td->td_sigstk.ss_flags = SS_DISABLE; 1036 td->td_sigstk.ss_size = 0; 1037 td->td_sigstk.ss_sp = 0; 1038 td->td_pflags &= ~TDP_ALTSTACK; 1039 /* 1040 * Reset no zombies if child dies flag as Solaris does. 1041 */ 1042 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1043 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1044 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1045 mtx_unlock(&ps->ps_mtx); 1046 } 1047 1048 /* 1049 * kern_sigprocmask() 1050 * 1051 * Manipulate signal mask. 1052 */ 1053 int 1054 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1055 int flags) 1056 { 1057 sigset_t new_block, oset1; 1058 struct proc *p; 1059 int error; 1060 1061 p = td->td_proc; 1062 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1063 PROC_LOCK_ASSERT(p, MA_OWNED); 1064 else 1065 PROC_LOCK(p); 1066 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1067 ? MA_OWNED : MA_NOTOWNED); 1068 if (oset != NULL) 1069 *oset = td->td_sigmask; 1070 1071 error = 0; 1072 if (set != NULL) { 1073 switch (how) { 1074 case SIG_BLOCK: 1075 SIG_CANTMASK(*set); 1076 oset1 = td->td_sigmask; 1077 SIGSETOR(td->td_sigmask, *set); 1078 new_block = td->td_sigmask; 1079 SIGSETNAND(new_block, oset1); 1080 break; 1081 case SIG_UNBLOCK: 1082 SIGSETNAND(td->td_sigmask, *set); 1083 signotify(td); 1084 goto out; 1085 case SIG_SETMASK: 1086 SIG_CANTMASK(*set); 1087 oset1 = td->td_sigmask; 1088 if (flags & SIGPROCMASK_OLD) 1089 SIGSETLO(td->td_sigmask, *set); 1090 else 1091 td->td_sigmask = *set; 1092 new_block = td->td_sigmask; 1093 SIGSETNAND(new_block, oset1); 1094 signotify(td); 1095 break; 1096 default: 1097 error = EINVAL; 1098 goto out; 1099 } 1100 1101 /* 1102 * The new_block set contains signals that were not previously 1103 * blocked, but are blocked now. 1104 * 1105 * In case we block any signal that was not previously blocked 1106 * for td, and process has the signal pending, try to schedule 1107 * signal delivery to some thread that does not block the 1108 * signal, possibly waking it up. 1109 */ 1110 if (p->p_numthreads != 1) 1111 reschedule_signals(p, new_block, flags); 1112 } 1113 1114 out: 1115 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1116 PROC_UNLOCK(p); 1117 return (error); 1118 } 1119 1120 #ifndef _SYS_SYSPROTO_H_ 1121 struct sigprocmask_args { 1122 int how; 1123 const sigset_t *set; 1124 sigset_t *oset; 1125 }; 1126 #endif 1127 int 1128 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1129 { 1130 sigset_t set, oset; 1131 sigset_t *setp, *osetp; 1132 int error; 1133 1134 setp = (uap->set != NULL) ? &set : NULL; 1135 osetp = (uap->oset != NULL) ? &oset : NULL; 1136 if (setp) { 1137 error = copyin(uap->set, setp, sizeof(set)); 1138 if (error) 1139 return (error); 1140 } 1141 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1142 if (osetp && !error) { 1143 error = copyout(osetp, uap->oset, sizeof(oset)); 1144 } 1145 return (error); 1146 } 1147 1148 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1149 #ifndef _SYS_SYSPROTO_H_ 1150 struct osigprocmask_args { 1151 int how; 1152 osigset_t mask; 1153 }; 1154 #endif 1155 int 1156 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1157 { 1158 sigset_t set, oset; 1159 int error; 1160 1161 OSIG2SIG(uap->mask, set); 1162 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1163 SIG2OSIG(oset, td->td_retval[0]); 1164 return (error); 1165 } 1166 #endif /* COMPAT_43 */ 1167 1168 int 1169 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1170 { 1171 ksiginfo_t ksi; 1172 sigset_t set; 1173 int error; 1174 1175 error = copyin(uap->set, &set, sizeof(set)); 1176 if (error) { 1177 td->td_retval[0] = error; 1178 return (0); 1179 } 1180 1181 error = kern_sigtimedwait(td, set, &ksi, NULL); 1182 if (error) { 1183 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1184 error = ERESTART; 1185 if (error == ERESTART) 1186 return (error); 1187 td->td_retval[0] = error; 1188 return (0); 1189 } 1190 1191 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1192 td->td_retval[0] = error; 1193 return (0); 1194 } 1195 1196 int 1197 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1198 { 1199 struct timespec ts; 1200 struct timespec *timeout; 1201 sigset_t set; 1202 ksiginfo_t ksi; 1203 int error; 1204 1205 if (uap->timeout) { 1206 error = copyin(uap->timeout, &ts, sizeof(ts)); 1207 if (error) 1208 return (error); 1209 1210 timeout = &ts; 1211 } else 1212 timeout = NULL; 1213 1214 error = copyin(uap->set, &set, sizeof(set)); 1215 if (error) 1216 return (error); 1217 1218 error = kern_sigtimedwait(td, set, &ksi, timeout); 1219 if (error) 1220 return (error); 1221 1222 if (uap->info) 1223 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1224 1225 if (error == 0) 1226 td->td_retval[0] = ksi.ksi_signo; 1227 return (error); 1228 } 1229 1230 int 1231 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1232 { 1233 ksiginfo_t ksi; 1234 sigset_t set; 1235 int error; 1236 1237 error = copyin(uap->set, &set, sizeof(set)); 1238 if (error) 1239 return (error); 1240 1241 error = kern_sigtimedwait(td, set, &ksi, NULL); 1242 if (error) 1243 return (error); 1244 1245 if (uap->info) 1246 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1247 1248 if (error == 0) 1249 td->td_retval[0] = ksi.ksi_signo; 1250 return (error); 1251 } 1252 1253 static void 1254 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1255 { 1256 struct thread *thr; 1257 1258 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1259 if (thr == td) 1260 thr->td_si = *si; 1261 else 1262 thr->td_si.si_signo = 0; 1263 } 1264 } 1265 1266 int 1267 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1268 struct timespec *timeout) 1269 { 1270 struct sigacts *ps; 1271 sigset_t saved_mask, new_block; 1272 struct proc *p; 1273 int error, sig, timo, timevalid = 0; 1274 struct timespec rts, ets, ts; 1275 struct timeval tv; 1276 1277 p = td->td_proc; 1278 error = 0; 1279 ets.tv_sec = 0; 1280 ets.tv_nsec = 0; 1281 1282 if (timeout != NULL) { 1283 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1284 timevalid = 1; 1285 getnanouptime(&rts); 1286 timespecadd(&rts, timeout, &ets); 1287 } 1288 } 1289 ksiginfo_init(ksi); 1290 /* Some signals can not be waited for. */ 1291 SIG_CANTMASK(waitset); 1292 ps = p->p_sigacts; 1293 PROC_LOCK(p); 1294 saved_mask = td->td_sigmask; 1295 SIGSETNAND(td->td_sigmask, waitset); 1296 for (;;) { 1297 mtx_lock(&ps->ps_mtx); 1298 sig = cursig(td); 1299 mtx_unlock(&ps->ps_mtx); 1300 KASSERT(sig >= 0, ("sig %d", sig)); 1301 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1302 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1303 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1304 error = 0; 1305 break; 1306 } 1307 } 1308 1309 if (error != 0) 1310 break; 1311 1312 /* 1313 * POSIX says this must be checked after looking for pending 1314 * signals. 1315 */ 1316 if (timeout != NULL) { 1317 if (!timevalid) { 1318 error = EINVAL; 1319 break; 1320 } 1321 getnanouptime(&rts); 1322 if (timespeccmp(&rts, &ets, >=)) { 1323 error = EAGAIN; 1324 break; 1325 } 1326 timespecsub(&ets, &rts, &ts); 1327 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1328 timo = tvtohz(&tv); 1329 } else { 1330 timo = 0; 1331 } 1332 1333 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1334 1335 if (timeout != NULL) { 1336 if (error == ERESTART) { 1337 /* Timeout can not be restarted. */ 1338 error = EINTR; 1339 } else if (error == EAGAIN) { 1340 /* We will calculate timeout by ourself. */ 1341 error = 0; 1342 } 1343 } 1344 } 1345 1346 new_block = saved_mask; 1347 SIGSETNAND(new_block, td->td_sigmask); 1348 td->td_sigmask = saved_mask; 1349 /* 1350 * Fewer signals can be delivered to us, reschedule signal 1351 * notification. 1352 */ 1353 if (p->p_numthreads != 1) 1354 reschedule_signals(p, new_block, 0); 1355 1356 if (error == 0) { 1357 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1358 1359 if (ksi->ksi_code == SI_TIMER) 1360 itimer_accept(p, ksi->ksi_timerid, ksi); 1361 1362 #ifdef KTRACE 1363 if (KTRPOINT(td, KTR_PSIG)) { 1364 sig_t action; 1365 1366 mtx_lock(&ps->ps_mtx); 1367 action = ps->ps_sigact[_SIG_IDX(sig)]; 1368 mtx_unlock(&ps->ps_mtx); 1369 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1370 } 1371 #endif 1372 if (sig == SIGKILL) { 1373 proc_td_siginfo_capture(td, &ksi->ksi_info); 1374 sigexit(td, sig); 1375 } 1376 } 1377 PROC_UNLOCK(p); 1378 return (error); 1379 } 1380 1381 #ifndef _SYS_SYSPROTO_H_ 1382 struct sigpending_args { 1383 sigset_t *set; 1384 }; 1385 #endif 1386 int 1387 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1388 { 1389 struct proc *p = td->td_proc; 1390 sigset_t pending; 1391 1392 PROC_LOCK(p); 1393 pending = p->p_sigqueue.sq_signals; 1394 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1395 PROC_UNLOCK(p); 1396 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1397 } 1398 1399 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1400 #ifndef _SYS_SYSPROTO_H_ 1401 struct osigpending_args { 1402 int dummy; 1403 }; 1404 #endif 1405 int 1406 osigpending(struct thread *td, struct osigpending_args *uap) 1407 { 1408 struct proc *p = td->td_proc; 1409 sigset_t pending; 1410 1411 PROC_LOCK(p); 1412 pending = p->p_sigqueue.sq_signals; 1413 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1414 PROC_UNLOCK(p); 1415 SIG2OSIG(pending, td->td_retval[0]); 1416 return (0); 1417 } 1418 #endif /* COMPAT_43 */ 1419 1420 #if defined(COMPAT_43) 1421 /* 1422 * Generalized interface signal handler, 4.3-compatible. 1423 */ 1424 #ifndef _SYS_SYSPROTO_H_ 1425 struct osigvec_args { 1426 int signum; 1427 struct sigvec *nsv; 1428 struct sigvec *osv; 1429 }; 1430 #endif 1431 /* ARGSUSED */ 1432 int 1433 osigvec(struct thread *td, struct osigvec_args *uap) 1434 { 1435 struct sigvec vec; 1436 struct sigaction nsa, osa; 1437 struct sigaction *nsap, *osap; 1438 int error; 1439 1440 if (uap->signum <= 0 || uap->signum >= ONSIG) 1441 return (EINVAL); 1442 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1443 osap = (uap->osv != NULL) ? &osa : NULL; 1444 if (nsap) { 1445 error = copyin(uap->nsv, &vec, sizeof(vec)); 1446 if (error) 1447 return (error); 1448 nsap->sa_handler = vec.sv_handler; 1449 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1450 nsap->sa_flags = vec.sv_flags; 1451 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1452 } 1453 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1454 if (osap && !error) { 1455 vec.sv_handler = osap->sa_handler; 1456 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1457 vec.sv_flags = osap->sa_flags; 1458 vec.sv_flags &= ~SA_NOCLDWAIT; 1459 vec.sv_flags ^= SA_RESTART; 1460 error = copyout(&vec, uap->osv, sizeof(vec)); 1461 } 1462 return (error); 1463 } 1464 1465 #ifndef _SYS_SYSPROTO_H_ 1466 struct osigblock_args { 1467 int mask; 1468 }; 1469 #endif 1470 int 1471 osigblock(struct thread *td, struct osigblock_args *uap) 1472 { 1473 sigset_t set, oset; 1474 1475 OSIG2SIG(uap->mask, set); 1476 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1477 SIG2OSIG(oset, td->td_retval[0]); 1478 return (0); 1479 } 1480 1481 #ifndef _SYS_SYSPROTO_H_ 1482 struct osigsetmask_args { 1483 int mask; 1484 }; 1485 #endif 1486 int 1487 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1488 { 1489 sigset_t set, oset; 1490 1491 OSIG2SIG(uap->mask, set); 1492 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1493 SIG2OSIG(oset, td->td_retval[0]); 1494 return (0); 1495 } 1496 #endif /* COMPAT_43 */ 1497 1498 /* 1499 * Suspend calling thread until signal, providing mask to be set in the 1500 * meantime. 1501 */ 1502 #ifndef _SYS_SYSPROTO_H_ 1503 struct sigsuspend_args { 1504 const sigset_t *sigmask; 1505 }; 1506 #endif 1507 /* ARGSUSED */ 1508 int 1509 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1510 { 1511 sigset_t mask; 1512 int error; 1513 1514 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1515 if (error) 1516 return (error); 1517 return (kern_sigsuspend(td, mask)); 1518 } 1519 1520 int 1521 kern_sigsuspend(struct thread *td, sigset_t mask) 1522 { 1523 struct proc *p = td->td_proc; 1524 int has_sig, sig; 1525 1526 /* 1527 * When returning from sigsuspend, we want 1528 * the old mask to be restored after the 1529 * signal handler has finished. Thus, we 1530 * save it here and mark the sigacts structure 1531 * to indicate this. 1532 */ 1533 PROC_LOCK(p); 1534 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1535 SIGPROCMASK_PROC_LOCKED); 1536 td->td_pflags |= TDP_OLDMASK; 1537 1538 /* 1539 * Process signals now. Otherwise, we can get spurious wakeup 1540 * due to signal entered process queue, but delivered to other 1541 * thread. But sigsuspend should return only on signal 1542 * delivery. 1543 */ 1544 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1545 for (has_sig = 0; !has_sig;) { 1546 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1547 0) == 0) 1548 /* void */; 1549 thread_suspend_check(0); 1550 mtx_lock(&p->p_sigacts->ps_mtx); 1551 while ((sig = cursig(td)) != 0) { 1552 KASSERT(sig >= 0, ("sig %d", sig)); 1553 has_sig += postsig(sig); 1554 } 1555 mtx_unlock(&p->p_sigacts->ps_mtx); 1556 } 1557 PROC_UNLOCK(p); 1558 td->td_errno = EINTR; 1559 td->td_pflags |= TDP_NERRNO; 1560 return (EJUSTRETURN); 1561 } 1562 1563 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1564 /* 1565 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1566 * convention: libc stub passes mask, not pointer, to save a copyin. 1567 */ 1568 #ifndef _SYS_SYSPROTO_H_ 1569 struct osigsuspend_args { 1570 osigset_t mask; 1571 }; 1572 #endif 1573 /* ARGSUSED */ 1574 int 1575 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1576 { 1577 sigset_t mask; 1578 1579 OSIG2SIG(uap->mask, mask); 1580 return (kern_sigsuspend(td, mask)); 1581 } 1582 #endif /* COMPAT_43 */ 1583 1584 #if defined(COMPAT_43) 1585 #ifndef _SYS_SYSPROTO_H_ 1586 struct osigstack_args { 1587 struct sigstack *nss; 1588 struct sigstack *oss; 1589 }; 1590 #endif 1591 /* ARGSUSED */ 1592 int 1593 osigstack(struct thread *td, struct osigstack_args *uap) 1594 { 1595 struct sigstack nss, oss; 1596 int error = 0; 1597 1598 if (uap->nss != NULL) { 1599 error = copyin(uap->nss, &nss, sizeof(nss)); 1600 if (error) 1601 return (error); 1602 } 1603 oss.ss_sp = td->td_sigstk.ss_sp; 1604 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1605 if (uap->nss != NULL) { 1606 td->td_sigstk.ss_sp = nss.ss_sp; 1607 td->td_sigstk.ss_size = 0; 1608 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1609 td->td_pflags |= TDP_ALTSTACK; 1610 } 1611 if (uap->oss != NULL) 1612 error = copyout(&oss, uap->oss, sizeof(oss)); 1613 1614 return (error); 1615 } 1616 #endif /* COMPAT_43 */ 1617 1618 #ifndef _SYS_SYSPROTO_H_ 1619 struct sigaltstack_args { 1620 stack_t *ss; 1621 stack_t *oss; 1622 }; 1623 #endif 1624 /* ARGSUSED */ 1625 int 1626 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1627 { 1628 stack_t ss, oss; 1629 int error; 1630 1631 if (uap->ss != NULL) { 1632 error = copyin(uap->ss, &ss, sizeof(ss)); 1633 if (error) 1634 return (error); 1635 } 1636 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1637 (uap->oss != NULL) ? &oss : NULL); 1638 if (error) 1639 return (error); 1640 if (uap->oss != NULL) 1641 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1642 return (error); 1643 } 1644 1645 int 1646 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1647 { 1648 struct proc *p = td->td_proc; 1649 int oonstack; 1650 1651 oonstack = sigonstack(cpu_getstack(td)); 1652 1653 if (oss != NULL) { 1654 *oss = td->td_sigstk; 1655 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1656 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1657 } 1658 1659 if (ss != NULL) { 1660 if (oonstack) 1661 return (EPERM); 1662 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1663 return (EINVAL); 1664 if (!(ss->ss_flags & SS_DISABLE)) { 1665 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1666 return (ENOMEM); 1667 1668 td->td_sigstk = *ss; 1669 td->td_pflags |= TDP_ALTSTACK; 1670 } else { 1671 td->td_pflags &= ~TDP_ALTSTACK; 1672 } 1673 } 1674 return (0); 1675 } 1676 1677 /* 1678 * Common code for kill process group/broadcast kill. 1679 * cp is calling process. 1680 */ 1681 static int 1682 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1683 { 1684 struct proc *p; 1685 struct pgrp *pgrp; 1686 int err; 1687 int ret; 1688 1689 ret = ESRCH; 1690 if (all) { 1691 /* 1692 * broadcast 1693 */ 1694 sx_slock(&allproc_lock); 1695 FOREACH_PROC_IN_SYSTEM(p) { 1696 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1697 p == td->td_proc || p->p_state == PRS_NEW) { 1698 continue; 1699 } 1700 PROC_LOCK(p); 1701 err = p_cansignal(td, p, sig); 1702 if (err == 0) { 1703 if (sig) 1704 pksignal(p, sig, ksi); 1705 ret = err; 1706 } 1707 else if (ret == ESRCH) 1708 ret = err; 1709 PROC_UNLOCK(p); 1710 } 1711 sx_sunlock(&allproc_lock); 1712 } else { 1713 sx_slock(&proctree_lock); 1714 if (pgid == 0) { 1715 /* 1716 * zero pgid means send to my process group. 1717 */ 1718 pgrp = td->td_proc->p_pgrp; 1719 PGRP_LOCK(pgrp); 1720 } else { 1721 pgrp = pgfind(pgid); 1722 if (pgrp == NULL) { 1723 sx_sunlock(&proctree_lock); 1724 return (ESRCH); 1725 } 1726 } 1727 sx_sunlock(&proctree_lock); 1728 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1729 PROC_LOCK(p); 1730 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1731 p->p_state == PRS_NEW) { 1732 PROC_UNLOCK(p); 1733 continue; 1734 } 1735 err = p_cansignal(td, p, sig); 1736 if (err == 0) { 1737 if (sig) 1738 pksignal(p, sig, ksi); 1739 ret = err; 1740 } 1741 else if (ret == ESRCH) 1742 ret = err; 1743 PROC_UNLOCK(p); 1744 } 1745 PGRP_UNLOCK(pgrp); 1746 } 1747 return (ret); 1748 } 1749 1750 #ifndef _SYS_SYSPROTO_H_ 1751 struct kill_args { 1752 int pid; 1753 int signum; 1754 }; 1755 #endif 1756 /* ARGSUSED */ 1757 int 1758 sys_kill(struct thread *td, struct kill_args *uap) 1759 { 1760 ksiginfo_t ksi; 1761 struct proc *p; 1762 int error; 1763 1764 /* 1765 * A process in capability mode can send signals only to himself. 1766 * The main rationale behind this is that abort(3) is implemented as 1767 * kill(getpid(), SIGABRT). 1768 */ 1769 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1770 return (ECAPMODE); 1771 1772 AUDIT_ARG_SIGNUM(uap->signum); 1773 AUDIT_ARG_PID(uap->pid); 1774 if ((u_int)uap->signum > _SIG_MAXSIG) 1775 return (EINVAL); 1776 1777 ksiginfo_init(&ksi); 1778 ksi.ksi_signo = uap->signum; 1779 ksi.ksi_code = SI_USER; 1780 ksi.ksi_pid = td->td_proc->p_pid; 1781 ksi.ksi_uid = td->td_ucred->cr_ruid; 1782 1783 if (uap->pid > 0) { 1784 /* kill single process */ 1785 if ((p = pfind_any(uap->pid)) == NULL) 1786 return (ESRCH); 1787 AUDIT_ARG_PROCESS(p); 1788 error = p_cansignal(td, p, uap->signum); 1789 if (error == 0 && uap->signum) 1790 pksignal(p, uap->signum, &ksi); 1791 PROC_UNLOCK(p); 1792 return (error); 1793 } 1794 switch (uap->pid) { 1795 case -1: /* broadcast signal */ 1796 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1797 case 0: /* signal own process group */ 1798 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1799 default: /* negative explicit process group */ 1800 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1801 } 1802 /* NOTREACHED */ 1803 } 1804 1805 int 1806 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1807 { 1808 struct proc *p; 1809 int error; 1810 1811 AUDIT_ARG_SIGNUM(uap->signum); 1812 AUDIT_ARG_FD(uap->fd); 1813 if ((u_int)uap->signum > _SIG_MAXSIG) 1814 return (EINVAL); 1815 1816 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1817 if (error) 1818 return (error); 1819 AUDIT_ARG_PROCESS(p); 1820 error = p_cansignal(td, p, uap->signum); 1821 if (error == 0 && uap->signum) 1822 kern_psignal(p, uap->signum); 1823 PROC_UNLOCK(p); 1824 return (error); 1825 } 1826 1827 #if defined(COMPAT_43) 1828 #ifndef _SYS_SYSPROTO_H_ 1829 struct okillpg_args { 1830 int pgid; 1831 int signum; 1832 }; 1833 #endif 1834 /* ARGSUSED */ 1835 int 1836 okillpg(struct thread *td, struct okillpg_args *uap) 1837 { 1838 ksiginfo_t ksi; 1839 1840 AUDIT_ARG_SIGNUM(uap->signum); 1841 AUDIT_ARG_PID(uap->pgid); 1842 if ((u_int)uap->signum > _SIG_MAXSIG) 1843 return (EINVAL); 1844 1845 ksiginfo_init(&ksi); 1846 ksi.ksi_signo = uap->signum; 1847 ksi.ksi_code = SI_USER; 1848 ksi.ksi_pid = td->td_proc->p_pid; 1849 ksi.ksi_uid = td->td_ucred->cr_ruid; 1850 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1851 } 1852 #endif /* COMPAT_43 */ 1853 1854 #ifndef _SYS_SYSPROTO_H_ 1855 struct sigqueue_args { 1856 pid_t pid; 1857 int signum; 1858 /* union sigval */ void *value; 1859 }; 1860 #endif 1861 int 1862 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1863 { 1864 union sigval sv; 1865 1866 sv.sival_ptr = uap->value; 1867 1868 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1869 } 1870 1871 int 1872 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1873 { 1874 ksiginfo_t ksi; 1875 struct proc *p; 1876 int error; 1877 1878 if ((u_int)signum > _SIG_MAXSIG) 1879 return (EINVAL); 1880 1881 /* 1882 * Specification says sigqueue can only send signal to 1883 * single process. 1884 */ 1885 if (pid <= 0) 1886 return (EINVAL); 1887 1888 if ((p = pfind_any(pid)) == NULL) 1889 return (ESRCH); 1890 error = p_cansignal(td, p, signum); 1891 if (error == 0 && signum != 0) { 1892 ksiginfo_init(&ksi); 1893 ksi.ksi_flags = KSI_SIGQ; 1894 ksi.ksi_signo = signum; 1895 ksi.ksi_code = SI_QUEUE; 1896 ksi.ksi_pid = td->td_proc->p_pid; 1897 ksi.ksi_uid = td->td_ucred->cr_ruid; 1898 ksi.ksi_value = *value; 1899 error = pksignal(p, ksi.ksi_signo, &ksi); 1900 } 1901 PROC_UNLOCK(p); 1902 return (error); 1903 } 1904 1905 /* 1906 * Send a signal to a process group. 1907 */ 1908 void 1909 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1910 { 1911 struct pgrp *pgrp; 1912 1913 if (pgid != 0) { 1914 sx_slock(&proctree_lock); 1915 pgrp = pgfind(pgid); 1916 sx_sunlock(&proctree_lock); 1917 if (pgrp != NULL) { 1918 pgsignal(pgrp, sig, 0, ksi); 1919 PGRP_UNLOCK(pgrp); 1920 } 1921 } 1922 } 1923 1924 /* 1925 * Send a signal to a process group. If checktty is 1, 1926 * limit to members which have a controlling terminal. 1927 */ 1928 void 1929 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1930 { 1931 struct proc *p; 1932 1933 if (pgrp) { 1934 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1935 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1936 PROC_LOCK(p); 1937 if (p->p_state == PRS_NORMAL && 1938 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1939 pksignal(p, sig, ksi); 1940 PROC_UNLOCK(p); 1941 } 1942 } 1943 } 1944 1945 1946 /* 1947 * Recalculate the signal mask and reset the signal disposition after 1948 * usermode frame for delivery is formed. Should be called after 1949 * mach-specific routine, because sysent->sv_sendsig() needs correct 1950 * ps_siginfo and signal mask. 1951 */ 1952 static void 1953 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1954 { 1955 sigset_t mask; 1956 1957 mtx_assert(&ps->ps_mtx, MA_OWNED); 1958 td->td_ru.ru_nsignals++; 1959 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1960 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1961 SIGADDSET(mask, sig); 1962 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1963 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1964 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1965 sigdflt(ps, sig); 1966 } 1967 1968 1969 /* 1970 * Send a signal caused by a trap to the current thread. If it will be 1971 * caught immediately, deliver it with correct code. Otherwise, post it 1972 * normally. 1973 */ 1974 void 1975 trapsignal(struct thread *td, ksiginfo_t *ksi) 1976 { 1977 struct sigacts *ps; 1978 struct proc *p; 1979 int sig; 1980 int code; 1981 1982 p = td->td_proc; 1983 sig = ksi->ksi_signo; 1984 code = ksi->ksi_code; 1985 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1986 1987 PROC_LOCK(p); 1988 ps = p->p_sigacts; 1989 mtx_lock(&ps->ps_mtx); 1990 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1991 !SIGISMEMBER(td->td_sigmask, sig)) { 1992 #ifdef KTRACE 1993 if (KTRPOINT(curthread, KTR_PSIG)) 1994 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1995 &td->td_sigmask, code); 1996 #endif 1997 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1998 ksi, &td->td_sigmask); 1999 postsig_done(sig, td, ps); 2000 mtx_unlock(&ps->ps_mtx); 2001 } else { 2002 /* 2003 * Avoid a possible infinite loop if the thread 2004 * masking the signal or process is ignoring the 2005 * signal. 2006 */ 2007 if (kern_forcesigexit && 2008 (SIGISMEMBER(td->td_sigmask, sig) || 2009 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2010 SIGDELSET(td->td_sigmask, sig); 2011 SIGDELSET(ps->ps_sigcatch, sig); 2012 SIGDELSET(ps->ps_sigignore, sig); 2013 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2014 } 2015 mtx_unlock(&ps->ps_mtx); 2016 p->p_sig = sig; /* XXX to verify code */ 2017 tdsendsignal(p, td, sig, ksi); 2018 } 2019 PROC_UNLOCK(p); 2020 } 2021 2022 static struct thread * 2023 sigtd(struct proc *p, int sig, int prop) 2024 { 2025 struct thread *td, *signal_td; 2026 2027 PROC_LOCK_ASSERT(p, MA_OWNED); 2028 2029 /* 2030 * Check if current thread can handle the signal without 2031 * switching context to another thread. 2032 */ 2033 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2034 return (curthread); 2035 signal_td = NULL; 2036 FOREACH_THREAD_IN_PROC(p, td) { 2037 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2038 signal_td = td; 2039 break; 2040 } 2041 } 2042 if (signal_td == NULL) 2043 signal_td = FIRST_THREAD_IN_PROC(p); 2044 return (signal_td); 2045 } 2046 2047 /* 2048 * Send the signal to the process. If the signal has an action, the action 2049 * is usually performed by the target process rather than the caller; we add 2050 * the signal to the set of pending signals for the process. 2051 * 2052 * Exceptions: 2053 * o When a stop signal is sent to a sleeping process that takes the 2054 * default action, the process is stopped without awakening it. 2055 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2056 * regardless of the signal action (eg, blocked or ignored). 2057 * 2058 * Other ignored signals are discarded immediately. 2059 * 2060 * NB: This function may be entered from the debugger via the "kill" DDB 2061 * command. There is little that can be done to mitigate the possibly messy 2062 * side effects of this unwise possibility. 2063 */ 2064 void 2065 kern_psignal(struct proc *p, int sig) 2066 { 2067 ksiginfo_t ksi; 2068 2069 ksiginfo_init(&ksi); 2070 ksi.ksi_signo = sig; 2071 ksi.ksi_code = SI_KERNEL; 2072 (void) tdsendsignal(p, NULL, sig, &ksi); 2073 } 2074 2075 int 2076 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2077 { 2078 2079 return (tdsendsignal(p, NULL, sig, ksi)); 2080 } 2081 2082 /* Utility function for finding a thread to send signal event to. */ 2083 int 2084 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2085 { 2086 struct thread *td; 2087 2088 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2089 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2090 if (td == NULL) 2091 return (ESRCH); 2092 *ttd = td; 2093 } else { 2094 *ttd = NULL; 2095 PROC_LOCK(p); 2096 } 2097 return (0); 2098 } 2099 2100 void 2101 tdsignal(struct thread *td, int sig) 2102 { 2103 ksiginfo_t ksi; 2104 2105 ksiginfo_init(&ksi); 2106 ksi.ksi_signo = sig; 2107 ksi.ksi_code = SI_KERNEL; 2108 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2109 } 2110 2111 void 2112 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2113 { 2114 2115 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2116 } 2117 2118 int 2119 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2120 { 2121 sig_t action; 2122 sigqueue_t *sigqueue; 2123 int prop; 2124 struct sigacts *ps; 2125 int intrval; 2126 int ret = 0; 2127 int wakeup_swapper; 2128 2129 MPASS(td == NULL || p == td->td_proc); 2130 PROC_LOCK_ASSERT(p, MA_OWNED); 2131 2132 if (!_SIG_VALID(sig)) 2133 panic("%s(): invalid signal %d", __func__, sig); 2134 2135 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2136 2137 /* 2138 * IEEE Std 1003.1-2001: return success when killing a zombie. 2139 */ 2140 if (p->p_state == PRS_ZOMBIE) { 2141 if (ksi && (ksi->ksi_flags & KSI_INS)) 2142 ksiginfo_tryfree(ksi); 2143 return (ret); 2144 } 2145 2146 ps = p->p_sigacts; 2147 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2148 prop = sigprop(sig); 2149 2150 if (td == NULL) { 2151 td = sigtd(p, sig, prop); 2152 sigqueue = &p->p_sigqueue; 2153 } else 2154 sigqueue = &td->td_sigqueue; 2155 2156 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2157 2158 /* 2159 * If the signal is being ignored, 2160 * then we forget about it immediately. 2161 * (Note: we don't set SIGCONT in ps_sigignore, 2162 * and if it is set to SIG_IGN, 2163 * action will be SIG_DFL here.) 2164 */ 2165 mtx_lock(&ps->ps_mtx); 2166 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2167 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2168 2169 mtx_unlock(&ps->ps_mtx); 2170 if (ksi && (ksi->ksi_flags & KSI_INS)) 2171 ksiginfo_tryfree(ksi); 2172 return (ret); 2173 } 2174 if (SIGISMEMBER(td->td_sigmask, sig)) 2175 action = SIG_HOLD; 2176 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2177 action = SIG_CATCH; 2178 else 2179 action = SIG_DFL; 2180 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2181 intrval = EINTR; 2182 else 2183 intrval = ERESTART; 2184 mtx_unlock(&ps->ps_mtx); 2185 2186 if (prop & SIGPROP_CONT) 2187 sigqueue_delete_stopmask_proc(p); 2188 else if (prop & SIGPROP_STOP) { 2189 /* 2190 * If sending a tty stop signal to a member of an orphaned 2191 * process group, discard the signal here if the action 2192 * is default; don't stop the process below if sleeping, 2193 * and don't clear any pending SIGCONT. 2194 */ 2195 if ((prop & SIGPROP_TTYSTOP) && 2196 (p->p_pgrp->pg_jobc == 0) && 2197 (action == SIG_DFL)) { 2198 if (ksi && (ksi->ksi_flags & KSI_INS)) 2199 ksiginfo_tryfree(ksi); 2200 return (ret); 2201 } 2202 sigqueue_delete_proc(p, SIGCONT); 2203 if (p->p_flag & P_CONTINUED) { 2204 p->p_flag &= ~P_CONTINUED; 2205 PROC_LOCK(p->p_pptr); 2206 sigqueue_take(p->p_ksi); 2207 PROC_UNLOCK(p->p_pptr); 2208 } 2209 } 2210 2211 ret = sigqueue_add(sigqueue, sig, ksi); 2212 if (ret != 0) 2213 return (ret); 2214 signotify(td); 2215 /* 2216 * Defer further processing for signals which are held, 2217 * except that stopped processes must be continued by SIGCONT. 2218 */ 2219 if (action == SIG_HOLD && 2220 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2221 return (ret); 2222 2223 /* SIGKILL: Remove procfs STOPEVENTs. */ 2224 if (sig == SIGKILL) { 2225 /* from procfs_ioctl.c: PIOCBIC */ 2226 p->p_stops = 0; 2227 /* from procfs_ioctl.c: PIOCCONT */ 2228 p->p_step = 0; 2229 wakeup(&p->p_step); 2230 } 2231 /* 2232 * Some signals have a process-wide effect and a per-thread 2233 * component. Most processing occurs when the process next 2234 * tries to cross the user boundary, however there are some 2235 * times when processing needs to be done immediately, such as 2236 * waking up threads so that they can cross the user boundary. 2237 * We try to do the per-process part here. 2238 */ 2239 if (P_SHOULDSTOP(p)) { 2240 KASSERT(!(p->p_flag & P_WEXIT), 2241 ("signal to stopped but exiting process")); 2242 if (sig == SIGKILL) { 2243 /* 2244 * If traced process is already stopped, 2245 * then no further action is necessary. 2246 */ 2247 if (p->p_flag & P_TRACED) 2248 goto out; 2249 /* 2250 * SIGKILL sets process running. 2251 * It will die elsewhere. 2252 * All threads must be restarted. 2253 */ 2254 p->p_flag &= ~P_STOPPED_SIG; 2255 goto runfast; 2256 } 2257 2258 if (prop & SIGPROP_CONT) { 2259 /* 2260 * If traced process is already stopped, 2261 * then no further action is necessary. 2262 */ 2263 if (p->p_flag & P_TRACED) 2264 goto out; 2265 /* 2266 * If SIGCONT is default (or ignored), we continue the 2267 * process but don't leave the signal in sigqueue as 2268 * it has no further action. If SIGCONT is held, we 2269 * continue the process and leave the signal in 2270 * sigqueue. If the process catches SIGCONT, let it 2271 * handle the signal itself. If it isn't waiting on 2272 * an event, it goes back to run state. 2273 * Otherwise, process goes back to sleep state. 2274 */ 2275 p->p_flag &= ~P_STOPPED_SIG; 2276 PROC_SLOCK(p); 2277 if (p->p_numthreads == p->p_suspcount) { 2278 PROC_SUNLOCK(p); 2279 p->p_flag |= P_CONTINUED; 2280 p->p_xsig = SIGCONT; 2281 PROC_LOCK(p->p_pptr); 2282 childproc_continued(p); 2283 PROC_UNLOCK(p->p_pptr); 2284 PROC_SLOCK(p); 2285 } 2286 if (action == SIG_DFL) { 2287 thread_unsuspend(p); 2288 PROC_SUNLOCK(p); 2289 sigqueue_delete(sigqueue, sig); 2290 goto out; 2291 } 2292 if (action == SIG_CATCH) { 2293 /* 2294 * The process wants to catch it so it needs 2295 * to run at least one thread, but which one? 2296 */ 2297 PROC_SUNLOCK(p); 2298 goto runfast; 2299 } 2300 /* 2301 * The signal is not ignored or caught. 2302 */ 2303 thread_unsuspend(p); 2304 PROC_SUNLOCK(p); 2305 goto out; 2306 } 2307 2308 if (prop & SIGPROP_STOP) { 2309 /* 2310 * If traced process is already stopped, 2311 * then no further action is necessary. 2312 */ 2313 if (p->p_flag & P_TRACED) 2314 goto out; 2315 /* 2316 * Already stopped, don't need to stop again 2317 * (If we did the shell could get confused). 2318 * Just make sure the signal STOP bit set. 2319 */ 2320 p->p_flag |= P_STOPPED_SIG; 2321 sigqueue_delete(sigqueue, sig); 2322 goto out; 2323 } 2324 2325 /* 2326 * All other kinds of signals: 2327 * If a thread is sleeping interruptibly, simulate a 2328 * wakeup so that when it is continued it will be made 2329 * runnable and can look at the signal. However, don't make 2330 * the PROCESS runnable, leave it stopped. 2331 * It may run a bit until it hits a thread_suspend_check(). 2332 */ 2333 wakeup_swapper = 0; 2334 PROC_SLOCK(p); 2335 thread_lock(td); 2336 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2337 wakeup_swapper = sleepq_abort(td, intrval); 2338 thread_unlock(td); 2339 PROC_SUNLOCK(p); 2340 if (wakeup_swapper) 2341 kick_proc0(); 2342 goto out; 2343 /* 2344 * Mutexes are short lived. Threads waiting on them will 2345 * hit thread_suspend_check() soon. 2346 */ 2347 } else if (p->p_state == PRS_NORMAL) { 2348 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2349 tdsigwakeup(td, sig, action, intrval); 2350 goto out; 2351 } 2352 2353 MPASS(action == SIG_DFL); 2354 2355 if (prop & SIGPROP_STOP) { 2356 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2357 goto out; 2358 p->p_flag |= P_STOPPED_SIG; 2359 p->p_xsig = sig; 2360 PROC_SLOCK(p); 2361 wakeup_swapper = sig_suspend_threads(td, p, 1); 2362 if (p->p_numthreads == p->p_suspcount) { 2363 /* 2364 * only thread sending signal to another 2365 * process can reach here, if thread is sending 2366 * signal to its process, because thread does 2367 * not suspend itself here, p_numthreads 2368 * should never be equal to p_suspcount. 2369 */ 2370 thread_stopped(p); 2371 PROC_SUNLOCK(p); 2372 sigqueue_delete_proc(p, p->p_xsig); 2373 } else 2374 PROC_SUNLOCK(p); 2375 if (wakeup_swapper) 2376 kick_proc0(); 2377 goto out; 2378 } 2379 } else { 2380 /* Not in "NORMAL" state. discard the signal. */ 2381 sigqueue_delete(sigqueue, sig); 2382 goto out; 2383 } 2384 2385 /* 2386 * The process is not stopped so we need to apply the signal to all the 2387 * running threads. 2388 */ 2389 runfast: 2390 tdsigwakeup(td, sig, action, intrval); 2391 PROC_SLOCK(p); 2392 thread_unsuspend(p); 2393 PROC_SUNLOCK(p); 2394 out: 2395 /* If we jump here, proc slock should not be owned. */ 2396 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2397 return (ret); 2398 } 2399 2400 /* 2401 * The force of a signal has been directed against a single 2402 * thread. We need to see what we can do about knocking it 2403 * out of any sleep it may be in etc. 2404 */ 2405 static void 2406 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2407 { 2408 struct proc *p = td->td_proc; 2409 int prop; 2410 int wakeup_swapper; 2411 2412 wakeup_swapper = 0; 2413 PROC_LOCK_ASSERT(p, MA_OWNED); 2414 prop = sigprop(sig); 2415 2416 PROC_SLOCK(p); 2417 thread_lock(td); 2418 /* 2419 * Bring the priority of a thread up if we want it to get 2420 * killed in this lifetime. Be careful to avoid bumping the 2421 * priority of the idle thread, since we still allow to signal 2422 * kernel processes. 2423 */ 2424 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2425 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2426 sched_prio(td, PUSER); 2427 if (TD_ON_SLEEPQ(td)) { 2428 /* 2429 * If thread is sleeping uninterruptibly 2430 * we can't interrupt the sleep... the signal will 2431 * be noticed when the process returns through 2432 * trap() or syscall(). 2433 */ 2434 if ((td->td_flags & TDF_SINTR) == 0) 2435 goto out; 2436 /* 2437 * If SIGCONT is default (or ignored) and process is 2438 * asleep, we are finished; the process should not 2439 * be awakened. 2440 */ 2441 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2442 thread_unlock(td); 2443 PROC_SUNLOCK(p); 2444 sigqueue_delete(&p->p_sigqueue, sig); 2445 /* 2446 * It may be on either list in this state. 2447 * Remove from both for now. 2448 */ 2449 sigqueue_delete(&td->td_sigqueue, sig); 2450 return; 2451 } 2452 2453 /* 2454 * Don't awaken a sleeping thread for SIGSTOP if the 2455 * STOP signal is deferred. 2456 */ 2457 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2458 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2459 goto out; 2460 2461 /* 2462 * Give low priority threads a better chance to run. 2463 */ 2464 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2465 sched_prio(td, PUSER); 2466 2467 wakeup_swapper = sleepq_abort(td, intrval); 2468 } else { 2469 /* 2470 * Other states do nothing with the signal immediately, 2471 * other than kicking ourselves if we are running. 2472 * It will either never be noticed, or noticed very soon. 2473 */ 2474 #ifdef SMP 2475 if (TD_IS_RUNNING(td) && td != curthread) 2476 forward_signal(td); 2477 #endif 2478 } 2479 out: 2480 PROC_SUNLOCK(p); 2481 thread_unlock(td); 2482 if (wakeup_swapper) 2483 kick_proc0(); 2484 } 2485 2486 static int 2487 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2488 { 2489 struct thread *td2; 2490 int wakeup_swapper; 2491 2492 PROC_LOCK_ASSERT(p, MA_OWNED); 2493 PROC_SLOCK_ASSERT(p, MA_OWNED); 2494 MPASS(sending || td == curthread); 2495 2496 wakeup_swapper = 0; 2497 FOREACH_THREAD_IN_PROC(p, td2) { 2498 thread_lock(td2); 2499 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2500 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2501 (td2->td_flags & TDF_SINTR)) { 2502 if (td2->td_flags & TDF_SBDRY) { 2503 /* 2504 * Once a thread is asleep with 2505 * TDF_SBDRY and without TDF_SERESTART 2506 * or TDF_SEINTR set, it should never 2507 * become suspended due to this check. 2508 */ 2509 KASSERT(!TD_IS_SUSPENDED(td2), 2510 ("thread with deferred stops suspended")); 2511 if (TD_SBDRY_INTR(td2)) 2512 wakeup_swapper |= sleepq_abort(td2, 2513 TD_SBDRY_ERRNO(td2)); 2514 } else if (!TD_IS_SUSPENDED(td2)) { 2515 thread_suspend_one(td2); 2516 } 2517 } else if (!TD_IS_SUSPENDED(td2)) { 2518 if (sending || td != td2) 2519 td2->td_flags |= TDF_ASTPENDING; 2520 #ifdef SMP 2521 if (TD_IS_RUNNING(td2) && td2 != td) 2522 forward_signal(td2); 2523 #endif 2524 } 2525 thread_unlock(td2); 2526 } 2527 return (wakeup_swapper); 2528 } 2529 2530 /* 2531 * Stop the process for an event deemed interesting to the debugger. If si is 2532 * non-NULL, this is a signal exchange; the new signal requested by the 2533 * debugger will be returned for handling. If si is NULL, this is some other 2534 * type of interesting event. The debugger may request a signal be delivered in 2535 * that case as well, however it will be deferred until it can be handled. 2536 */ 2537 int 2538 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2539 { 2540 struct proc *p = td->td_proc; 2541 struct thread *td2; 2542 ksiginfo_t ksi; 2543 int prop; 2544 2545 PROC_LOCK_ASSERT(p, MA_OWNED); 2546 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2547 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2548 &p->p_mtx.lock_object, "Stopping for traced signal"); 2549 2550 td->td_xsig = sig; 2551 2552 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2553 td->td_dbgflags |= TDB_XSIG; 2554 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2555 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2556 PROC_SLOCK(p); 2557 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2558 if (P_KILLED(p)) { 2559 /* 2560 * Ensure that, if we've been PT_KILLed, the 2561 * exit status reflects that. Another thread 2562 * may also be in ptracestop(), having just 2563 * received the SIGKILL, but this thread was 2564 * unsuspended first. 2565 */ 2566 td->td_dbgflags &= ~TDB_XSIG; 2567 td->td_xsig = SIGKILL; 2568 p->p_ptevents = 0; 2569 break; 2570 } 2571 if (p->p_flag & P_SINGLE_EXIT && 2572 !(td->td_dbgflags & TDB_EXIT)) { 2573 /* 2574 * Ignore ptrace stops except for thread exit 2575 * events when the process exits. 2576 */ 2577 td->td_dbgflags &= ~TDB_XSIG; 2578 PROC_SUNLOCK(p); 2579 return (0); 2580 } 2581 2582 /* 2583 * Make wait(2) work. Ensure that right after the 2584 * attach, the thread which was decided to become the 2585 * leader of attach gets reported to the waiter. 2586 * Otherwise, just avoid overwriting another thread's 2587 * assignment to p_xthread. If another thread has 2588 * already set p_xthread, the current thread will get 2589 * a chance to report itself upon the next iteration. 2590 */ 2591 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2592 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2593 p->p_xthread == NULL)) { 2594 p->p_xsig = sig; 2595 p->p_xthread = td; 2596 2597 /* 2598 * If we are on sleepqueue already, 2599 * let sleepqueue code decide if it 2600 * needs to go sleep after attach. 2601 */ 2602 if (td->td_wchan == NULL) 2603 td->td_dbgflags &= ~TDB_FSTP; 2604 2605 p->p_flag2 &= ~P2_PTRACE_FSTP; 2606 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2607 sig_suspend_threads(td, p, 0); 2608 } 2609 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2610 td->td_dbgflags &= ~TDB_STOPATFORK; 2611 } 2612 stopme: 2613 thread_suspend_switch(td, p); 2614 if (p->p_xthread == td) 2615 p->p_xthread = NULL; 2616 if (!(p->p_flag & P_TRACED)) 2617 break; 2618 if (td->td_dbgflags & TDB_SUSPEND) { 2619 if (p->p_flag & P_SINGLE_EXIT) 2620 break; 2621 goto stopme; 2622 } 2623 } 2624 PROC_SUNLOCK(p); 2625 } 2626 2627 if (si != NULL && sig == td->td_xsig) { 2628 /* Parent wants us to take the original signal unchanged. */ 2629 si->ksi_flags |= KSI_HEAD; 2630 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2631 si->ksi_signo = 0; 2632 } else if (td->td_xsig != 0) { 2633 /* 2634 * If parent wants us to take a new signal, then it will leave 2635 * it in td->td_xsig; otherwise we just look for signals again. 2636 */ 2637 ksiginfo_init(&ksi); 2638 ksi.ksi_signo = td->td_xsig; 2639 ksi.ksi_flags |= KSI_PTRACE; 2640 prop = sigprop(td->td_xsig); 2641 td2 = sigtd(p, td->td_xsig, prop); 2642 tdsendsignal(p, td2, td->td_xsig, &ksi); 2643 if (td != td2) 2644 return (0); 2645 } 2646 2647 return (td->td_xsig); 2648 } 2649 2650 static void 2651 reschedule_signals(struct proc *p, sigset_t block, int flags) 2652 { 2653 struct sigacts *ps; 2654 struct thread *td; 2655 int sig; 2656 2657 PROC_LOCK_ASSERT(p, MA_OWNED); 2658 ps = p->p_sigacts; 2659 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2660 MA_OWNED : MA_NOTOWNED); 2661 if (SIGISEMPTY(p->p_siglist)) 2662 return; 2663 SIGSETAND(block, p->p_siglist); 2664 while ((sig = sig_ffs(&block)) != 0) { 2665 SIGDELSET(block, sig); 2666 td = sigtd(p, sig, 0); 2667 signotify(td); 2668 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2669 mtx_lock(&ps->ps_mtx); 2670 if (p->p_flag & P_TRACED || 2671 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2672 !SIGISMEMBER(td->td_sigmask, sig))) 2673 tdsigwakeup(td, sig, SIG_CATCH, 2674 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2675 ERESTART)); 2676 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2677 mtx_unlock(&ps->ps_mtx); 2678 } 2679 } 2680 2681 void 2682 tdsigcleanup(struct thread *td) 2683 { 2684 struct proc *p; 2685 sigset_t unblocked; 2686 2687 p = td->td_proc; 2688 PROC_LOCK_ASSERT(p, MA_OWNED); 2689 2690 sigqueue_flush(&td->td_sigqueue); 2691 if (p->p_numthreads == 1) 2692 return; 2693 2694 /* 2695 * Since we cannot handle signals, notify signal post code 2696 * about this by filling the sigmask. 2697 * 2698 * Also, if needed, wake up thread(s) that do not block the 2699 * same signals as the exiting thread, since the thread might 2700 * have been selected for delivery and woken up. 2701 */ 2702 SIGFILLSET(unblocked); 2703 SIGSETNAND(unblocked, td->td_sigmask); 2704 SIGFILLSET(td->td_sigmask); 2705 reschedule_signals(p, unblocked, 0); 2706 2707 } 2708 2709 static int 2710 sigdeferstop_curr_flags(int cflags) 2711 { 2712 2713 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2714 (cflags & TDF_SBDRY) != 0); 2715 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2716 } 2717 2718 /* 2719 * Defer the delivery of SIGSTOP for the current thread, according to 2720 * the requested mode. Returns previous flags, which must be restored 2721 * by sigallowstop(). 2722 * 2723 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2724 * cleared by the current thread, which allow the lock-less read-only 2725 * accesses below. 2726 */ 2727 int 2728 sigdeferstop_impl(int mode) 2729 { 2730 struct thread *td; 2731 int cflags, nflags; 2732 2733 td = curthread; 2734 cflags = sigdeferstop_curr_flags(td->td_flags); 2735 switch (mode) { 2736 case SIGDEFERSTOP_NOP: 2737 nflags = cflags; 2738 break; 2739 case SIGDEFERSTOP_OFF: 2740 nflags = 0; 2741 break; 2742 case SIGDEFERSTOP_SILENT: 2743 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2744 break; 2745 case SIGDEFERSTOP_EINTR: 2746 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2747 break; 2748 case SIGDEFERSTOP_ERESTART: 2749 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2750 break; 2751 default: 2752 panic("sigdeferstop: invalid mode %x", mode); 2753 break; 2754 } 2755 if (cflags == nflags) 2756 return (SIGDEFERSTOP_VAL_NCHG); 2757 thread_lock(td); 2758 td->td_flags = (td->td_flags & ~cflags) | nflags; 2759 thread_unlock(td); 2760 return (cflags); 2761 } 2762 2763 /* 2764 * Restores the STOP handling mode, typically permitting the delivery 2765 * of SIGSTOP for the current thread. This does not immediately 2766 * suspend if a stop was posted. Instead, the thread will suspend 2767 * either via ast() or a subsequent interruptible sleep. 2768 */ 2769 void 2770 sigallowstop_impl(int prev) 2771 { 2772 struct thread *td; 2773 int cflags; 2774 2775 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2776 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2777 ("sigallowstop: incorrect previous mode %x", prev)); 2778 td = curthread; 2779 cflags = sigdeferstop_curr_flags(td->td_flags); 2780 if (cflags != prev) { 2781 thread_lock(td); 2782 td->td_flags = (td->td_flags & ~cflags) | prev; 2783 thread_unlock(td); 2784 } 2785 } 2786 2787 /* 2788 * If the current process has received a signal (should be caught or cause 2789 * termination, should interrupt current syscall), return the signal number. 2790 * Stop signals with default action are processed immediately, then cleared; 2791 * they aren't returned. This is checked after each entry to the system for 2792 * a syscall or trap (though this can usually be done without calling issignal 2793 * by checking the pending signal masks in cursig.) The normal call 2794 * sequence is 2795 * 2796 * while (sig = cursig(curthread)) 2797 * postsig(sig); 2798 */ 2799 static int 2800 issignal(struct thread *td) 2801 { 2802 struct proc *p; 2803 struct sigacts *ps; 2804 struct sigqueue *queue; 2805 sigset_t sigpending; 2806 ksiginfo_t ksi; 2807 int prop, sig, traced; 2808 2809 p = td->td_proc; 2810 ps = p->p_sigacts; 2811 mtx_assert(&ps->ps_mtx, MA_OWNED); 2812 PROC_LOCK_ASSERT(p, MA_OWNED); 2813 for (;;) { 2814 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2815 2816 sigpending = td->td_sigqueue.sq_signals; 2817 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2818 SIGSETNAND(sigpending, td->td_sigmask); 2819 2820 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2821 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2822 SIG_STOPSIGMASK(sigpending); 2823 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2824 return (0); 2825 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2826 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2827 SIGISMEMBER(sigpending, SIGSTOP)) { 2828 /* 2829 * If debugger just attached, always consume 2830 * SIGSTOP from ptrace(PT_ATTACH) first, to 2831 * execute the debugger attach ritual in 2832 * order. 2833 */ 2834 sig = SIGSTOP; 2835 td->td_dbgflags |= TDB_FSTP; 2836 } else { 2837 sig = sig_ffs(&sigpending); 2838 } 2839 2840 if (p->p_stops & S_SIG) { 2841 mtx_unlock(&ps->ps_mtx); 2842 stopevent(p, S_SIG, sig); 2843 mtx_lock(&ps->ps_mtx); 2844 } 2845 2846 /* 2847 * We should see pending but ignored signals 2848 * only if P_TRACED was on when they were posted. 2849 */ 2850 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2851 sigqueue_delete(&td->td_sigqueue, sig); 2852 sigqueue_delete(&p->p_sigqueue, sig); 2853 continue; 2854 } 2855 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2856 /* 2857 * If traced, always stop. 2858 * Remove old signal from queue before the stop. 2859 * XXX shrug off debugger, it causes siginfo to 2860 * be thrown away. 2861 */ 2862 queue = &td->td_sigqueue; 2863 ksiginfo_init(&ksi); 2864 if (sigqueue_get(queue, sig, &ksi) == 0) { 2865 queue = &p->p_sigqueue; 2866 sigqueue_get(queue, sig, &ksi); 2867 } 2868 td->td_si = ksi.ksi_info; 2869 2870 mtx_unlock(&ps->ps_mtx); 2871 sig = ptracestop(td, sig, &ksi); 2872 mtx_lock(&ps->ps_mtx); 2873 2874 td->td_si.si_signo = 0; 2875 2876 /* 2877 * Keep looking if the debugger discarded or 2878 * replaced the signal. 2879 */ 2880 if (sig == 0) 2881 continue; 2882 2883 /* 2884 * If the signal became masked, re-queue it. 2885 */ 2886 if (SIGISMEMBER(td->td_sigmask, sig)) { 2887 ksi.ksi_flags |= KSI_HEAD; 2888 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2889 continue; 2890 } 2891 2892 /* 2893 * If the traced bit got turned off, requeue 2894 * the signal and go back up to the top to 2895 * rescan signals. This ensures that p_sig* 2896 * and p_sigact are consistent. 2897 */ 2898 if ((p->p_flag & P_TRACED) == 0) { 2899 ksi.ksi_flags |= KSI_HEAD; 2900 sigqueue_add(queue, sig, &ksi); 2901 continue; 2902 } 2903 } 2904 2905 prop = sigprop(sig); 2906 2907 /* 2908 * Decide whether the signal should be returned. 2909 * Return the signal's number, or fall through 2910 * to clear it from the pending mask. 2911 */ 2912 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2913 2914 case (intptr_t)SIG_DFL: 2915 /* 2916 * Don't take default actions on system processes. 2917 */ 2918 if (p->p_pid <= 1) { 2919 #ifdef DIAGNOSTIC 2920 /* 2921 * Are you sure you want to ignore SIGSEGV 2922 * in init? XXX 2923 */ 2924 printf("Process (pid %lu) got signal %d\n", 2925 (u_long)p->p_pid, sig); 2926 #endif 2927 break; /* == ignore */ 2928 } 2929 /* 2930 * If there is a pending stop signal to process with 2931 * default action, stop here, then clear the signal. 2932 * Traced or exiting processes should ignore stops. 2933 * Additionally, a member of an orphaned process group 2934 * should ignore tty stops. 2935 */ 2936 if (prop & SIGPROP_STOP) { 2937 if (p->p_flag & 2938 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2939 (p->p_pgrp->pg_jobc == 0 && 2940 prop & SIGPROP_TTYSTOP)) 2941 break; /* == ignore */ 2942 if (TD_SBDRY_INTR(td)) { 2943 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2944 ("lost TDF_SBDRY")); 2945 return (-1); 2946 } 2947 mtx_unlock(&ps->ps_mtx); 2948 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2949 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2950 sigqueue_delete(&td->td_sigqueue, sig); 2951 sigqueue_delete(&p->p_sigqueue, sig); 2952 p->p_flag |= P_STOPPED_SIG; 2953 p->p_xsig = sig; 2954 PROC_SLOCK(p); 2955 sig_suspend_threads(td, p, 0); 2956 thread_suspend_switch(td, p); 2957 PROC_SUNLOCK(p); 2958 mtx_lock(&ps->ps_mtx); 2959 goto next; 2960 } else if (prop & SIGPROP_IGNORE) { 2961 /* 2962 * Except for SIGCONT, shouldn't get here. 2963 * Default action is to ignore; drop it. 2964 */ 2965 break; /* == ignore */ 2966 } else 2967 return (sig); 2968 /*NOTREACHED*/ 2969 2970 case (intptr_t)SIG_IGN: 2971 /* 2972 * Masking above should prevent us ever trying 2973 * to take action on an ignored signal other 2974 * than SIGCONT, unless process is traced. 2975 */ 2976 if ((prop & SIGPROP_CONT) == 0 && 2977 (p->p_flag & P_TRACED) == 0) 2978 printf("issignal\n"); 2979 break; /* == ignore */ 2980 2981 default: 2982 /* 2983 * This signal has an action, let 2984 * postsig() process it. 2985 */ 2986 return (sig); 2987 } 2988 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2989 sigqueue_delete(&p->p_sigqueue, sig); 2990 next:; 2991 } 2992 /* NOTREACHED */ 2993 } 2994 2995 void 2996 thread_stopped(struct proc *p) 2997 { 2998 int n; 2999 3000 PROC_LOCK_ASSERT(p, MA_OWNED); 3001 PROC_SLOCK_ASSERT(p, MA_OWNED); 3002 n = p->p_suspcount; 3003 if (p == curproc) 3004 n++; 3005 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3006 PROC_SUNLOCK(p); 3007 p->p_flag &= ~P_WAITED; 3008 PROC_LOCK(p->p_pptr); 3009 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3010 CLD_TRAPPED : CLD_STOPPED); 3011 PROC_UNLOCK(p->p_pptr); 3012 PROC_SLOCK(p); 3013 } 3014 } 3015 3016 /* 3017 * Take the action for the specified signal 3018 * from the current set of pending signals. 3019 */ 3020 int 3021 postsig(int sig) 3022 { 3023 struct thread *td; 3024 struct proc *p; 3025 struct sigacts *ps; 3026 sig_t action; 3027 ksiginfo_t ksi; 3028 sigset_t returnmask; 3029 3030 KASSERT(sig != 0, ("postsig")); 3031 3032 td = curthread; 3033 p = td->td_proc; 3034 PROC_LOCK_ASSERT(p, MA_OWNED); 3035 ps = p->p_sigacts; 3036 mtx_assert(&ps->ps_mtx, MA_OWNED); 3037 ksiginfo_init(&ksi); 3038 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3039 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3040 return (0); 3041 ksi.ksi_signo = sig; 3042 if (ksi.ksi_code == SI_TIMER) 3043 itimer_accept(p, ksi.ksi_timerid, &ksi); 3044 action = ps->ps_sigact[_SIG_IDX(sig)]; 3045 #ifdef KTRACE 3046 if (KTRPOINT(td, KTR_PSIG)) 3047 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3048 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3049 #endif 3050 if ((p->p_stops & S_SIG) != 0) { 3051 mtx_unlock(&ps->ps_mtx); 3052 stopevent(p, S_SIG, sig); 3053 mtx_lock(&ps->ps_mtx); 3054 } 3055 3056 if (action == SIG_DFL) { 3057 /* 3058 * Default action, where the default is to kill 3059 * the process. (Other cases were ignored above.) 3060 */ 3061 mtx_unlock(&ps->ps_mtx); 3062 proc_td_siginfo_capture(td, &ksi.ksi_info); 3063 sigexit(td, sig); 3064 /* NOTREACHED */ 3065 } else { 3066 /* 3067 * If we get here, the signal must be caught. 3068 */ 3069 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3070 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3071 ("postsig action: blocked sig %d", sig)); 3072 3073 /* 3074 * Set the new mask value and also defer further 3075 * occurrences of this signal. 3076 * 3077 * Special case: user has done a sigsuspend. Here the 3078 * current mask is not of interest, but rather the 3079 * mask from before the sigsuspend is what we want 3080 * restored after the signal processing is completed. 3081 */ 3082 if (td->td_pflags & TDP_OLDMASK) { 3083 returnmask = td->td_oldsigmask; 3084 td->td_pflags &= ~TDP_OLDMASK; 3085 } else 3086 returnmask = td->td_sigmask; 3087 3088 if (p->p_sig == sig) { 3089 p->p_sig = 0; 3090 } 3091 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3092 postsig_done(sig, td, ps); 3093 } 3094 return (1); 3095 } 3096 3097 void 3098 proc_wkilled(struct proc *p) 3099 { 3100 3101 PROC_LOCK_ASSERT(p, MA_OWNED); 3102 if ((p->p_flag & P_WKILLED) == 0) { 3103 p->p_flag |= P_WKILLED; 3104 /* 3105 * Notify swapper that there is a process to swap in. 3106 * The notification is racy, at worst it would take 10 3107 * seconds for the swapper process to notice. 3108 */ 3109 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3110 wakeup(&proc0); 3111 } 3112 } 3113 3114 /* 3115 * Kill the current process for stated reason. 3116 */ 3117 void 3118 killproc(struct proc *p, char *why) 3119 { 3120 3121 PROC_LOCK_ASSERT(p, MA_OWNED); 3122 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3123 p->p_comm); 3124 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3125 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3126 p->p_ucred->cr_uid, why); 3127 proc_wkilled(p); 3128 kern_psignal(p, SIGKILL); 3129 } 3130 3131 /* 3132 * Force the current process to exit with the specified signal, dumping core 3133 * if appropriate. We bypass the normal tests for masked and caught signals, 3134 * allowing unrecoverable failures to terminate the process without changing 3135 * signal state. Mark the accounting record with the signal termination. 3136 * If dumping core, save the signal number for the debugger. Calls exit and 3137 * does not return. 3138 */ 3139 void 3140 sigexit(struct thread *td, int sig) 3141 { 3142 struct proc *p = td->td_proc; 3143 3144 PROC_LOCK_ASSERT(p, MA_OWNED); 3145 p->p_acflag |= AXSIG; 3146 /* 3147 * We must be single-threading to generate a core dump. This 3148 * ensures that the registers in the core file are up-to-date. 3149 * Also, the ELF dump handler assumes that the thread list doesn't 3150 * change out from under it. 3151 * 3152 * XXX If another thread attempts to single-thread before us 3153 * (e.g. via fork()), we won't get a dump at all. 3154 */ 3155 if ((sigprop(sig) & SIGPROP_CORE) && 3156 thread_single(p, SINGLE_NO_EXIT) == 0) { 3157 p->p_sig = sig; 3158 /* 3159 * Log signals which would cause core dumps 3160 * (Log as LOG_INFO to appease those who don't want 3161 * these messages.) 3162 * XXX : Todo, as well as euid, write out ruid too 3163 * Note that coredump() drops proc lock. 3164 */ 3165 if (coredump(td) == 0) 3166 sig |= WCOREFLAG; 3167 if (kern_logsigexit) 3168 log(LOG_INFO, 3169 "pid %d (%s), jid %d, uid %d: exited on " 3170 "signal %d%s\n", p->p_pid, p->p_comm, 3171 p->p_ucred->cr_prison->pr_id, 3172 td->td_ucred->cr_uid, 3173 sig &~ WCOREFLAG, 3174 sig & WCOREFLAG ? " (core dumped)" : ""); 3175 } else 3176 PROC_UNLOCK(p); 3177 exit1(td, 0, sig); 3178 /* NOTREACHED */ 3179 } 3180 3181 /* 3182 * Send queued SIGCHLD to parent when child process's state 3183 * is changed. 3184 */ 3185 static void 3186 sigparent(struct proc *p, int reason, int status) 3187 { 3188 PROC_LOCK_ASSERT(p, MA_OWNED); 3189 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3190 3191 if (p->p_ksi != NULL) { 3192 p->p_ksi->ksi_signo = SIGCHLD; 3193 p->p_ksi->ksi_code = reason; 3194 p->p_ksi->ksi_status = status; 3195 p->p_ksi->ksi_pid = p->p_pid; 3196 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3197 if (KSI_ONQ(p->p_ksi)) 3198 return; 3199 } 3200 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3201 } 3202 3203 static void 3204 childproc_jobstate(struct proc *p, int reason, int sig) 3205 { 3206 struct sigacts *ps; 3207 3208 PROC_LOCK_ASSERT(p, MA_OWNED); 3209 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3210 3211 /* 3212 * Wake up parent sleeping in kern_wait(), also send 3213 * SIGCHLD to parent, but SIGCHLD does not guarantee 3214 * that parent will awake, because parent may masked 3215 * the signal. 3216 */ 3217 p->p_pptr->p_flag |= P_STATCHILD; 3218 wakeup(p->p_pptr); 3219 3220 ps = p->p_pptr->p_sigacts; 3221 mtx_lock(&ps->ps_mtx); 3222 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3223 mtx_unlock(&ps->ps_mtx); 3224 sigparent(p, reason, sig); 3225 } else 3226 mtx_unlock(&ps->ps_mtx); 3227 } 3228 3229 void 3230 childproc_stopped(struct proc *p, int reason) 3231 { 3232 3233 childproc_jobstate(p, reason, p->p_xsig); 3234 } 3235 3236 void 3237 childproc_continued(struct proc *p) 3238 { 3239 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3240 } 3241 3242 void 3243 childproc_exited(struct proc *p) 3244 { 3245 int reason, status; 3246 3247 if (WCOREDUMP(p->p_xsig)) { 3248 reason = CLD_DUMPED; 3249 status = WTERMSIG(p->p_xsig); 3250 } else if (WIFSIGNALED(p->p_xsig)) { 3251 reason = CLD_KILLED; 3252 status = WTERMSIG(p->p_xsig); 3253 } else { 3254 reason = CLD_EXITED; 3255 status = p->p_xexit; 3256 } 3257 /* 3258 * XXX avoid calling wakeup(p->p_pptr), the work is 3259 * done in exit1(). 3260 */ 3261 sigparent(p, reason, status); 3262 } 3263 3264 #define MAX_NUM_CORE_FILES 100000 3265 #ifndef NUM_CORE_FILES 3266 #define NUM_CORE_FILES 5 3267 #endif 3268 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3269 static int num_cores = NUM_CORE_FILES; 3270 3271 static int 3272 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3273 { 3274 int error; 3275 int new_val; 3276 3277 new_val = num_cores; 3278 error = sysctl_handle_int(oidp, &new_val, 0, req); 3279 if (error != 0 || req->newptr == NULL) 3280 return (error); 3281 if (new_val > MAX_NUM_CORE_FILES) 3282 new_val = MAX_NUM_CORE_FILES; 3283 if (new_val < 0) 3284 new_val = 0; 3285 num_cores = new_val; 3286 return (0); 3287 } 3288 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3289 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3290 "Maximum number of generated process corefiles while using index format"); 3291 3292 #define GZIP_SUFFIX ".gz" 3293 #define ZSTD_SUFFIX ".zst" 3294 3295 int compress_user_cores = 0; 3296 3297 static int 3298 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3299 { 3300 int error, val; 3301 3302 val = compress_user_cores; 3303 error = sysctl_handle_int(oidp, &val, 0, req); 3304 if (error != 0 || req->newptr == NULL) 3305 return (error); 3306 if (val != 0 && !compressor_avail(val)) 3307 return (EINVAL); 3308 compress_user_cores = val; 3309 return (error); 3310 } 3311 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3312 0, sizeof(int), sysctl_compress_user_cores, "I", 3313 "Enable compression of user corefiles (" 3314 __XSTRING(COMPRESS_GZIP) " = gzip, " 3315 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3316 3317 int compress_user_cores_level = 6; 3318 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3319 &compress_user_cores_level, 0, 3320 "Corefile compression level"); 3321 3322 /* 3323 * Protect the access to corefilename[] by allproc_lock. 3324 */ 3325 #define corefilename_lock allproc_lock 3326 3327 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3328 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3329 3330 static int 3331 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3332 { 3333 int error; 3334 3335 sx_xlock(&corefilename_lock); 3336 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3337 req); 3338 sx_xunlock(&corefilename_lock); 3339 3340 return (error); 3341 } 3342 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3343 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3344 "Process corefile name format string"); 3345 3346 static void 3347 vnode_close_locked(struct thread *td, struct vnode *vp) 3348 { 3349 3350 VOP_UNLOCK(vp, 0); 3351 vn_close(vp, FWRITE, td->td_ucred, td); 3352 } 3353 3354 /* 3355 * If the core format has a %I in it, then we need to check 3356 * for existing corefiles before defining a name. 3357 * To do this we iterate over 0..ncores to find a 3358 * non-existing core file name to use. If all core files are 3359 * already used we choose the oldest one. 3360 */ 3361 static int 3362 corefile_open_last(struct thread *td, char *name, int indexpos, 3363 int indexlen, int ncores, struct vnode **vpp) 3364 { 3365 struct vnode *oldvp, *nextvp, *vp; 3366 struct vattr vattr; 3367 struct nameidata nd; 3368 int error, i, flags, oflags, cmode; 3369 char ch; 3370 struct timespec lasttime; 3371 3372 nextvp = oldvp = NULL; 3373 cmode = S_IRUSR | S_IWUSR; 3374 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3375 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3376 3377 for (i = 0; i < ncores; i++) { 3378 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3379 3380 ch = name[indexpos + indexlen]; 3381 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3382 i); 3383 name[indexpos + indexlen] = ch; 3384 3385 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3386 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3387 NULL); 3388 if (error != 0) 3389 break; 3390 3391 vp = nd.ni_vp; 3392 NDFREE(&nd, NDF_ONLY_PNBUF); 3393 if ((flags & O_CREAT) == O_CREAT) { 3394 nextvp = vp; 3395 break; 3396 } 3397 3398 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3399 if (error != 0) { 3400 vnode_close_locked(td, vp); 3401 break; 3402 } 3403 3404 if (oldvp == NULL || 3405 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3406 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3407 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3408 if (oldvp != NULL) 3409 vnode_close_locked(td, oldvp); 3410 oldvp = vp; 3411 lasttime = vattr.va_mtime; 3412 } else { 3413 vnode_close_locked(td, vp); 3414 } 3415 } 3416 3417 if (oldvp != NULL) { 3418 if (nextvp == NULL) { 3419 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3420 error = EFAULT; 3421 vnode_close_locked(td, oldvp); 3422 } else { 3423 nextvp = oldvp; 3424 } 3425 } else { 3426 vnode_close_locked(td, oldvp); 3427 } 3428 } 3429 if (error != 0) { 3430 if (nextvp != NULL) 3431 vnode_close_locked(td, oldvp); 3432 } else { 3433 *vpp = nextvp; 3434 } 3435 3436 return (error); 3437 } 3438 3439 /* 3440 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3441 * Expand the name described in corefilename, using name, uid, and pid 3442 * and open/create core file. 3443 * corefilename is a printf-like string, with three format specifiers: 3444 * %N name of process ("name") 3445 * %P process id (pid) 3446 * %U user id (uid) 3447 * For example, "%N.core" is the default; they can be disabled completely 3448 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3449 * This is controlled by the sysctl variable kern.corefile (see above). 3450 */ 3451 static int 3452 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3453 int compress, struct vnode **vpp, char **namep) 3454 { 3455 struct sbuf sb; 3456 struct nameidata nd; 3457 const char *format; 3458 char *hostname, *name; 3459 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3460 3461 hostname = NULL; 3462 format = corefilename; 3463 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3464 indexlen = 0; 3465 indexpos = -1; 3466 ncores = num_cores; 3467 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3468 sx_slock(&corefilename_lock); 3469 for (i = 0; format[i] != '\0'; i++) { 3470 switch (format[i]) { 3471 case '%': /* Format character */ 3472 i++; 3473 switch (format[i]) { 3474 case '%': 3475 sbuf_putc(&sb, '%'); 3476 break; 3477 case 'H': /* hostname */ 3478 if (hostname == NULL) { 3479 hostname = malloc(MAXHOSTNAMELEN, 3480 M_TEMP, M_WAITOK); 3481 } 3482 getcredhostname(td->td_ucred, hostname, 3483 MAXHOSTNAMELEN); 3484 sbuf_printf(&sb, "%s", hostname); 3485 break; 3486 case 'I': /* autoincrementing index */ 3487 if (indexpos != -1) { 3488 sbuf_printf(&sb, "%%I"); 3489 break; 3490 } 3491 3492 indexpos = sbuf_len(&sb); 3493 sbuf_printf(&sb, "%u", ncores - 1); 3494 indexlen = sbuf_len(&sb) - indexpos; 3495 break; 3496 case 'N': /* process name */ 3497 sbuf_printf(&sb, "%s", comm); 3498 break; 3499 case 'P': /* process id */ 3500 sbuf_printf(&sb, "%u", pid); 3501 break; 3502 case 'U': /* user id */ 3503 sbuf_printf(&sb, "%u", uid); 3504 break; 3505 default: 3506 log(LOG_ERR, 3507 "Unknown format character %c in " 3508 "corename `%s'\n", format[i], format); 3509 break; 3510 } 3511 break; 3512 default: 3513 sbuf_putc(&sb, format[i]); 3514 break; 3515 } 3516 } 3517 sx_sunlock(&corefilename_lock); 3518 free(hostname, M_TEMP); 3519 if (compress == COMPRESS_GZIP) 3520 sbuf_printf(&sb, GZIP_SUFFIX); 3521 else if (compress == COMPRESS_ZSTD) 3522 sbuf_printf(&sb, ZSTD_SUFFIX); 3523 if (sbuf_error(&sb) != 0) { 3524 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3525 "long\n", (long)pid, comm, (u_long)uid); 3526 sbuf_delete(&sb); 3527 free(name, M_TEMP); 3528 return (ENOMEM); 3529 } 3530 sbuf_finish(&sb); 3531 sbuf_delete(&sb); 3532 3533 if (indexpos != -1) { 3534 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3535 vpp); 3536 if (error != 0) { 3537 log(LOG_ERR, 3538 "pid %d (%s), uid (%u): Path `%s' failed " 3539 "on initial open test, error = %d\n", 3540 pid, comm, uid, name, error); 3541 } 3542 } else { 3543 cmode = S_IRUSR | S_IWUSR; 3544 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3545 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3546 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3547 if ((td->td_proc->p_flag & P_SUGID) != 0) 3548 flags |= O_EXCL; 3549 3550 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3551 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3552 NULL); 3553 if (error == 0) { 3554 *vpp = nd.ni_vp; 3555 NDFREE(&nd, NDF_ONLY_PNBUF); 3556 } 3557 } 3558 3559 if (error != 0) { 3560 #ifdef AUDIT 3561 audit_proc_coredump(td, name, error); 3562 #endif 3563 free(name, M_TEMP); 3564 return (error); 3565 } 3566 *namep = name; 3567 return (0); 3568 } 3569 3570 /* 3571 * Dump a process' core. The main routine does some 3572 * policy checking, and creates the name of the coredump; 3573 * then it passes on a vnode and a size limit to the process-specific 3574 * coredump routine if there is one; if there _is not_ one, it returns 3575 * ENOSYS; otherwise it returns the error from the process-specific routine. 3576 */ 3577 3578 static int 3579 coredump(struct thread *td) 3580 { 3581 struct proc *p = td->td_proc; 3582 struct ucred *cred = td->td_ucred; 3583 struct vnode *vp; 3584 struct flock lf; 3585 struct vattr vattr; 3586 int error, error1, locked; 3587 char *name; /* name of corefile */ 3588 void *rl_cookie; 3589 off_t limit; 3590 char *fullpath, *freepath = NULL; 3591 struct sbuf *sb; 3592 3593 PROC_LOCK_ASSERT(p, MA_OWNED); 3594 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3595 _STOPEVENT(p, S_CORE, 0); 3596 3597 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3598 (p->p_flag2 & P2_NOTRACE) != 0) { 3599 PROC_UNLOCK(p); 3600 return (EFAULT); 3601 } 3602 3603 /* 3604 * Note that the bulk of limit checking is done after 3605 * the corefile is created. The exception is if the limit 3606 * for corefiles is 0, in which case we don't bother 3607 * creating the corefile at all. This layout means that 3608 * a corefile is truncated instead of not being created, 3609 * if it is larger than the limit. 3610 */ 3611 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3612 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3613 PROC_UNLOCK(p); 3614 return (EFBIG); 3615 } 3616 PROC_UNLOCK(p); 3617 3618 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3619 compress_user_cores, &vp, &name); 3620 if (error != 0) 3621 return (error); 3622 3623 /* 3624 * Don't dump to non-regular files or files with links. 3625 * Do not dump into system files. Effective user must own the corefile. 3626 */ 3627 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3628 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3629 vattr.va_uid != cred->cr_uid) { 3630 VOP_UNLOCK(vp, 0); 3631 error = EFAULT; 3632 goto out; 3633 } 3634 3635 VOP_UNLOCK(vp, 0); 3636 3637 /* Postpone other writers, including core dumps of other processes. */ 3638 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3639 3640 lf.l_whence = SEEK_SET; 3641 lf.l_start = 0; 3642 lf.l_len = 0; 3643 lf.l_type = F_WRLCK; 3644 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3645 3646 VATTR_NULL(&vattr); 3647 vattr.va_size = 0; 3648 if (set_core_nodump_flag) 3649 vattr.va_flags = UF_NODUMP; 3650 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3651 VOP_SETATTR(vp, &vattr, cred); 3652 VOP_UNLOCK(vp, 0); 3653 PROC_LOCK(p); 3654 p->p_acflag |= ACORE; 3655 PROC_UNLOCK(p); 3656 3657 if (p->p_sysent->sv_coredump != NULL) { 3658 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3659 } else { 3660 error = ENOSYS; 3661 } 3662 3663 if (locked) { 3664 lf.l_type = F_UNLCK; 3665 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3666 } 3667 vn_rangelock_unlock(vp, rl_cookie); 3668 3669 /* 3670 * Notify the userland helper that a process triggered a core dump. 3671 * This allows the helper to run an automated debugging session. 3672 */ 3673 if (error != 0 || coredump_devctl == 0) 3674 goto out; 3675 sb = sbuf_new_auto(); 3676 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3677 goto out2; 3678 sbuf_printf(sb, "comm=\""); 3679 devctl_safe_quote_sb(sb, fullpath); 3680 free(freepath, M_TEMP); 3681 sbuf_printf(sb, "\" core=\""); 3682 3683 /* 3684 * We can't lookup core file vp directly. When we're replacing a core, and 3685 * other random times, we flush the name cache, so it will fail. Instead, 3686 * if the path of the core is relative, add the current dir in front if it. 3687 */ 3688 if (name[0] != '/') { 3689 fullpath = malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 3690 if (kern___getcwd(td, fullpath, UIO_SYSSPACE, MAXPATHLEN, MAXPATHLEN) != 0) { 3691 free(fullpath, M_TEMP); 3692 goto out2; 3693 } 3694 devctl_safe_quote_sb(sb, fullpath); 3695 free(fullpath, M_TEMP); 3696 sbuf_putc(sb, '/'); 3697 } 3698 devctl_safe_quote_sb(sb, name); 3699 sbuf_printf(sb, "\""); 3700 if (sbuf_finish(sb) == 0) 3701 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3702 out2: 3703 sbuf_delete(sb); 3704 out: 3705 error1 = vn_close(vp, FWRITE, cred, td); 3706 if (error == 0) 3707 error = error1; 3708 #ifdef AUDIT 3709 audit_proc_coredump(td, name, error); 3710 #endif 3711 free(name, M_TEMP); 3712 return (error); 3713 } 3714 3715 /* 3716 * Nonexistent system call-- signal process (may want to handle it). Flag 3717 * error in case process won't see signal immediately (blocked or ignored). 3718 */ 3719 #ifndef _SYS_SYSPROTO_H_ 3720 struct nosys_args { 3721 int dummy; 3722 }; 3723 #endif 3724 /* ARGSUSED */ 3725 int 3726 nosys(struct thread *td, struct nosys_args *args) 3727 { 3728 struct proc *p; 3729 3730 p = td->td_proc; 3731 3732 PROC_LOCK(p); 3733 tdsignal(td, SIGSYS); 3734 PROC_UNLOCK(p); 3735 if (kern_lognosys == 1 || kern_lognosys == 3) { 3736 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3737 td->td_sa.code); 3738 } 3739 if (kern_lognosys == 2 || kern_lognosys == 3) { 3740 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3741 td->td_sa.code); 3742 } 3743 return (ENOSYS); 3744 } 3745 3746 /* 3747 * Send a SIGIO or SIGURG signal to a process or process group using stored 3748 * credentials rather than those of the current process. 3749 */ 3750 void 3751 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3752 { 3753 ksiginfo_t ksi; 3754 struct sigio *sigio; 3755 3756 ksiginfo_init(&ksi); 3757 ksi.ksi_signo = sig; 3758 ksi.ksi_code = SI_KERNEL; 3759 3760 SIGIO_LOCK(); 3761 sigio = *sigiop; 3762 if (sigio == NULL) { 3763 SIGIO_UNLOCK(); 3764 return; 3765 } 3766 if (sigio->sio_pgid > 0) { 3767 PROC_LOCK(sigio->sio_proc); 3768 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3769 kern_psignal(sigio->sio_proc, sig); 3770 PROC_UNLOCK(sigio->sio_proc); 3771 } else if (sigio->sio_pgid < 0) { 3772 struct proc *p; 3773 3774 PGRP_LOCK(sigio->sio_pgrp); 3775 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3776 PROC_LOCK(p); 3777 if (p->p_state == PRS_NORMAL && 3778 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3779 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3780 kern_psignal(p, sig); 3781 PROC_UNLOCK(p); 3782 } 3783 PGRP_UNLOCK(sigio->sio_pgrp); 3784 } 3785 SIGIO_UNLOCK(); 3786 } 3787 3788 static int 3789 filt_sigattach(struct knote *kn) 3790 { 3791 struct proc *p = curproc; 3792 3793 kn->kn_ptr.p_proc = p; 3794 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3795 3796 knlist_add(p->p_klist, kn, 0); 3797 3798 return (0); 3799 } 3800 3801 static void 3802 filt_sigdetach(struct knote *kn) 3803 { 3804 struct proc *p = kn->kn_ptr.p_proc; 3805 3806 knlist_remove(p->p_klist, kn, 0); 3807 } 3808 3809 /* 3810 * signal knotes are shared with proc knotes, so we apply a mask to 3811 * the hint in order to differentiate them from process hints. This 3812 * could be avoided by using a signal-specific knote list, but probably 3813 * isn't worth the trouble. 3814 */ 3815 static int 3816 filt_signal(struct knote *kn, long hint) 3817 { 3818 3819 if (hint & NOTE_SIGNAL) { 3820 hint &= ~NOTE_SIGNAL; 3821 3822 if (kn->kn_id == hint) 3823 kn->kn_data++; 3824 } 3825 return (kn->kn_data != 0); 3826 } 3827 3828 struct sigacts * 3829 sigacts_alloc(void) 3830 { 3831 struct sigacts *ps; 3832 3833 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3834 refcount_init(&ps->ps_refcnt, 1); 3835 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3836 return (ps); 3837 } 3838 3839 void 3840 sigacts_free(struct sigacts *ps) 3841 { 3842 3843 if (refcount_release(&ps->ps_refcnt) == 0) 3844 return; 3845 mtx_destroy(&ps->ps_mtx); 3846 free(ps, M_SUBPROC); 3847 } 3848 3849 struct sigacts * 3850 sigacts_hold(struct sigacts *ps) 3851 { 3852 3853 refcount_acquire(&ps->ps_refcnt); 3854 return (ps); 3855 } 3856 3857 void 3858 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3859 { 3860 3861 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3862 mtx_lock(&src->ps_mtx); 3863 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3864 mtx_unlock(&src->ps_mtx); 3865 } 3866 3867 int 3868 sigacts_shared(struct sigacts *ps) 3869 { 3870 3871 return (ps->ps_refcnt > 1); 3872 } 3873