1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/lock.h> 61 #include <sys/malloc.h> 62 #include <sys/mutex.h> 63 #include <sys/refcount.h> 64 #include <sys/namei.h> 65 #include <sys/proc.h> 66 #include <sys/procdesc.h> 67 #include <sys/posix4.h> 68 #include <sys/pioctl.h> 69 #include <sys/racct.h> 70 #include <sys/resourcevar.h> 71 #include <sys/sdt.h> 72 #include <sys/sbuf.h> 73 #include <sys/sleepqueue.h> 74 #include <sys/smp.h> 75 #include <sys/stat.h> 76 #include <sys/sx.h> 77 #include <sys/syscallsubr.h> 78 #include <sys/sysctl.h> 79 #include <sys/sysent.h> 80 #include <sys/syslog.h> 81 #include <sys/sysproto.h> 82 #include <sys/timers.h> 83 #include <sys/unistd.h> 84 #include <sys/wait.h> 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/uma.h> 88 89 #include <sys/jail.h> 90 91 #include <machine/cpu.h> 92 93 #include <security/audit/audit.h> 94 95 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE3(proc, , , signal__send, 99 "struct thread *", "struct proc *", "int"); 100 SDT_PROBE_DEFINE2(proc, , , signal__clear, 101 "int", "ksiginfo_t *"); 102 SDT_PROBE_DEFINE3(proc, , , signal__discard, 103 "struct thread *", "struct proc *", "int"); 104 105 static int coredump(struct thread *); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td); 109 static int sigprop(int sig); 110 static void tdsigwakeup(struct thread *, int, sig_t, int); 111 static int sig_suspend_threads(struct thread *, struct proc *, int); 112 static int filt_sigattach(struct knote *kn); 113 static void filt_sigdetach(struct knote *kn); 114 static int filt_signal(struct knote *kn, long hint); 115 static struct thread *sigtd(struct proc *p, int sig, int prop); 116 static void sigqueue_start(void); 117 118 static uma_zone_t ksiginfo_zone = NULL; 119 struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124 }; 125 126 static int kern_logsigexit = 1; 127 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131 static int kern_forcesigexit = 1; 132 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 136 "POSIX real time signal"); 137 138 static int max_pending_per_proc = 128; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 140 &max_pending_per_proc, 0, "Max pending signals per proc"); 141 142 static int preallocate_siginfo = 1024; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 static int kern_lognosys = 0; 155 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 156 "Log invalid syscalls"); 157 158 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160 /* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165 #define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172 static int sugid_coredump; 173 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176 static int capmode_coredump; 177 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180 static int do_coredump = 1; 181 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184 static int set_core_nodump_flag = 0; 185 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188 static int coredump_devctl = 0; 189 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192 /* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197 #define SIGPROP_KILL 0x01 /* terminates process by default */ 198 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 199 #define SIGPROP_STOP 0x04 /* suspend process */ 200 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 201 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 202 #define SIGPROP_CONT 0x20 /* continue if suspended */ 203 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 204 205 static int sigproptbl[NSIG] = { 206 [SIGHUP] = SIGPROP_KILL, 207 [SIGINT] = SIGPROP_KILL, 208 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 209 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGKILL] = SIGPROP_KILL, 215 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGPIPE] = SIGPROP_KILL, 219 [SIGALRM] = SIGPROP_KILL, 220 [SIGTERM] = SIGPROP_KILL, 221 [SIGURG] = SIGPROP_IGNORE, 222 [SIGSTOP] = SIGPROP_STOP, 223 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 224 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 225 [SIGCHLD] = SIGPROP_IGNORE, 226 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 227 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGIO] = SIGPROP_IGNORE, 229 [SIGXCPU] = SIGPROP_KILL, 230 [SIGXFSZ] = SIGPROP_KILL, 231 [SIGVTALRM] = SIGPROP_KILL, 232 [SIGPROF] = SIGPROP_KILL, 233 [SIGWINCH] = SIGPROP_IGNORE, 234 [SIGINFO] = SIGPROP_IGNORE, 235 [SIGUSR1] = SIGPROP_KILL, 236 [SIGUSR2] = SIGPROP_KILL, 237 }; 238 239 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241 static void 242 sigqueue_start(void) 243 { 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250 } 251 252 ksiginfo_t * 253 ksiginfo_alloc(int wait) 254 { 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263 } 264 265 void 266 ksiginfo_free(ksiginfo_t *ksi) 267 { 268 uma_zfree(ksiginfo_zone, ksi); 269 } 270 271 static __inline int 272 ksiginfo_tryfree(ksiginfo_t *ksi) 273 { 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279 } 280 281 void 282 sigqueue_init(sigqueue_t *list, struct proc *p) 283 { 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290 } 291 292 /* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298 static int 299 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300 { 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339 } 340 341 void 342 sigqueue_take(ksiginfo_t *ksi) 343 { 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365 } 366 367 static int 368 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369 { 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432 out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435 } 436 437 void 438 sigqueue_flush(sigqueue_t *sq) 439 { 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458 } 459 460 static void 461 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462 { 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499 } 500 501 #if 0 502 static void 503 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510 } 511 #endif 512 513 static void 514 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515 { 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533 } 534 535 void 536 sigqueue_delete(sigqueue_t *sq, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543 } 544 545 /* Remove a set of signals for a process */ 546 static void 547 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548 { 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561 } 562 563 void 564 sigqueue_delete_proc(struct proc *p, int signo) 565 { 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571 } 572 573 static void 574 sigqueue_delete_stopmask_proc(struct proc *p) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584 } 585 586 /* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591 int 592 cursig(struct thread *td) 593 { 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598 } 599 600 /* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605 void 606 signotify(struct thread *td) 607 { 608 struct proc *p; 609 610 p = td->td_proc; 611 612 PROC_LOCK_ASSERT(p, MA_OWNED); 613 614 if (SIGPENDING(td)) { 615 thread_lock(td); 616 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 617 thread_unlock(td); 618 } 619 } 620 621 int 622 sigonstack(size_t sp) 623 { 624 struct thread *td = curthread; 625 626 return ((td->td_pflags & TDP_ALTSTACK) ? 627 #if defined(COMPAT_43) 628 ((td->td_sigstk.ss_size == 0) ? 629 (td->td_sigstk.ss_flags & SS_ONSTACK) : 630 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 631 #else 632 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 633 #endif 634 : 0); 635 } 636 637 static __inline int 638 sigprop(int sig) 639 { 640 641 if (sig > 0 && sig < nitems(sigproptbl)) 642 return (sigproptbl[sig]); 643 return (0); 644 } 645 646 int 647 sig_ffs(sigset_t *set) 648 { 649 int i; 650 651 for (i = 0; i < _SIG_WORDS; i++) 652 if (set->__bits[i]) 653 return (ffs(set->__bits[i]) + (i * 32)); 654 return (0); 655 } 656 657 static bool 658 sigact_flag_test(const struct sigaction *act, int flag) 659 { 660 661 /* 662 * SA_SIGINFO is reset when signal disposition is set to 663 * ignore or default. Other flags are kept according to user 664 * settings. 665 */ 666 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 667 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 668 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 669 } 670 671 /* 672 * kern_sigaction 673 * sigaction 674 * freebsd4_sigaction 675 * osigaction 676 */ 677 int 678 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 679 struct sigaction *oact, int flags) 680 { 681 struct sigacts *ps; 682 struct proc *p = td->td_proc; 683 684 if (!_SIG_VALID(sig)) 685 return (EINVAL); 686 if (act != NULL && act->sa_handler != SIG_DFL && 687 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 688 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 689 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 690 return (EINVAL); 691 692 PROC_LOCK(p); 693 ps = p->p_sigacts; 694 mtx_lock(&ps->ps_mtx); 695 if (oact) { 696 memset(oact, 0, sizeof(*oact)); 697 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 698 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 699 oact->sa_flags |= SA_ONSTACK; 700 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 701 oact->sa_flags |= SA_RESTART; 702 if (SIGISMEMBER(ps->ps_sigreset, sig)) 703 oact->sa_flags |= SA_RESETHAND; 704 if (SIGISMEMBER(ps->ps_signodefer, sig)) 705 oact->sa_flags |= SA_NODEFER; 706 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 707 oact->sa_flags |= SA_SIGINFO; 708 oact->sa_sigaction = 709 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 710 } else 711 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 712 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 713 oact->sa_flags |= SA_NOCLDSTOP; 714 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 715 oact->sa_flags |= SA_NOCLDWAIT; 716 } 717 if (act) { 718 if ((sig == SIGKILL || sig == SIGSTOP) && 719 act->sa_handler != SIG_DFL) { 720 mtx_unlock(&ps->ps_mtx); 721 PROC_UNLOCK(p); 722 return (EINVAL); 723 } 724 725 /* 726 * Change setting atomically. 727 */ 728 729 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 730 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 731 if (sigact_flag_test(act, SA_SIGINFO)) { 732 ps->ps_sigact[_SIG_IDX(sig)] = 733 (__sighandler_t *)act->sa_sigaction; 734 SIGADDSET(ps->ps_siginfo, sig); 735 } else { 736 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 737 SIGDELSET(ps->ps_siginfo, sig); 738 } 739 if (!sigact_flag_test(act, SA_RESTART)) 740 SIGADDSET(ps->ps_sigintr, sig); 741 else 742 SIGDELSET(ps->ps_sigintr, sig); 743 if (sigact_flag_test(act, SA_ONSTACK)) 744 SIGADDSET(ps->ps_sigonstack, sig); 745 else 746 SIGDELSET(ps->ps_sigonstack, sig); 747 if (sigact_flag_test(act, SA_RESETHAND)) 748 SIGADDSET(ps->ps_sigreset, sig); 749 else 750 SIGDELSET(ps->ps_sigreset, sig); 751 if (sigact_flag_test(act, SA_NODEFER)) 752 SIGADDSET(ps->ps_signodefer, sig); 753 else 754 SIGDELSET(ps->ps_signodefer, sig); 755 if (sig == SIGCHLD) { 756 if (act->sa_flags & SA_NOCLDSTOP) 757 ps->ps_flag |= PS_NOCLDSTOP; 758 else 759 ps->ps_flag &= ~PS_NOCLDSTOP; 760 if (act->sa_flags & SA_NOCLDWAIT) { 761 /* 762 * Paranoia: since SA_NOCLDWAIT is implemented 763 * by reparenting the dying child to PID 1 (and 764 * trust it to reap the zombie), PID 1 itself 765 * is forbidden to set SA_NOCLDWAIT. 766 */ 767 if (p->p_pid == 1) 768 ps->ps_flag &= ~PS_NOCLDWAIT; 769 else 770 ps->ps_flag |= PS_NOCLDWAIT; 771 } else 772 ps->ps_flag &= ~PS_NOCLDWAIT; 773 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 774 ps->ps_flag |= PS_CLDSIGIGN; 775 else 776 ps->ps_flag &= ~PS_CLDSIGIGN; 777 } 778 /* 779 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 780 * and for signals set to SIG_DFL where the default is to 781 * ignore. However, don't put SIGCONT in ps_sigignore, as we 782 * have to restart the process. 783 */ 784 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 785 (sigprop(sig) & SIGPROP_IGNORE && 786 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 787 /* never to be seen again */ 788 sigqueue_delete_proc(p, sig); 789 if (sig != SIGCONT) 790 /* easier in psignal */ 791 SIGADDSET(ps->ps_sigignore, sig); 792 SIGDELSET(ps->ps_sigcatch, sig); 793 } else { 794 SIGDELSET(ps->ps_sigignore, sig); 795 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 796 SIGDELSET(ps->ps_sigcatch, sig); 797 else 798 SIGADDSET(ps->ps_sigcatch, sig); 799 } 800 #ifdef COMPAT_FREEBSD4 801 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 802 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 803 (flags & KSA_FREEBSD4) == 0) 804 SIGDELSET(ps->ps_freebsd4, sig); 805 else 806 SIGADDSET(ps->ps_freebsd4, sig); 807 #endif 808 #ifdef COMPAT_43 809 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 810 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 811 (flags & KSA_OSIGSET) == 0) 812 SIGDELSET(ps->ps_osigset, sig); 813 else 814 SIGADDSET(ps->ps_osigset, sig); 815 #endif 816 } 817 mtx_unlock(&ps->ps_mtx); 818 PROC_UNLOCK(p); 819 return (0); 820 } 821 822 #ifndef _SYS_SYSPROTO_H_ 823 struct sigaction_args { 824 int sig; 825 struct sigaction *act; 826 struct sigaction *oact; 827 }; 828 #endif 829 int 830 sys_sigaction(struct thread *td, struct sigaction_args *uap) 831 { 832 struct sigaction act, oact; 833 struct sigaction *actp, *oactp; 834 int error; 835 836 actp = (uap->act != NULL) ? &act : NULL; 837 oactp = (uap->oact != NULL) ? &oact : NULL; 838 if (actp) { 839 error = copyin(uap->act, actp, sizeof(act)); 840 if (error) 841 return (error); 842 } 843 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 844 if (oactp && !error) 845 error = copyout(oactp, uap->oact, sizeof(oact)); 846 return (error); 847 } 848 849 #ifdef COMPAT_FREEBSD4 850 #ifndef _SYS_SYSPROTO_H_ 851 struct freebsd4_sigaction_args { 852 int sig; 853 struct sigaction *act; 854 struct sigaction *oact; 855 }; 856 #endif 857 int 858 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 859 { 860 struct sigaction act, oact; 861 struct sigaction *actp, *oactp; 862 int error; 863 864 865 actp = (uap->act != NULL) ? &act : NULL; 866 oactp = (uap->oact != NULL) ? &oact : NULL; 867 if (actp) { 868 error = copyin(uap->act, actp, sizeof(act)); 869 if (error) 870 return (error); 871 } 872 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 873 if (oactp && !error) 874 error = copyout(oactp, uap->oact, sizeof(oact)); 875 return (error); 876 } 877 #endif /* COMAPT_FREEBSD4 */ 878 879 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 880 #ifndef _SYS_SYSPROTO_H_ 881 struct osigaction_args { 882 int signum; 883 struct osigaction *nsa; 884 struct osigaction *osa; 885 }; 886 #endif 887 int 888 osigaction(struct thread *td, struct osigaction_args *uap) 889 { 890 struct osigaction sa; 891 struct sigaction nsa, osa; 892 struct sigaction *nsap, *osap; 893 int error; 894 895 if (uap->signum <= 0 || uap->signum >= ONSIG) 896 return (EINVAL); 897 898 nsap = (uap->nsa != NULL) ? &nsa : NULL; 899 osap = (uap->osa != NULL) ? &osa : NULL; 900 901 if (nsap) { 902 error = copyin(uap->nsa, &sa, sizeof(sa)); 903 if (error) 904 return (error); 905 nsap->sa_handler = sa.sa_handler; 906 nsap->sa_flags = sa.sa_flags; 907 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 908 } 909 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 910 if (osap && !error) { 911 sa.sa_handler = osap->sa_handler; 912 sa.sa_flags = osap->sa_flags; 913 SIG2OSIG(osap->sa_mask, sa.sa_mask); 914 error = copyout(&sa, uap->osa, sizeof(sa)); 915 } 916 return (error); 917 } 918 919 #if !defined(__i386__) 920 /* Avoid replicating the same stub everywhere */ 921 int 922 osigreturn(struct thread *td, struct osigreturn_args *uap) 923 { 924 925 return (nosys(td, (struct nosys_args *)uap)); 926 } 927 #endif 928 #endif /* COMPAT_43 */ 929 930 /* 931 * Initialize signal state for process 0; 932 * set to ignore signals that are ignored by default. 933 */ 934 void 935 siginit(struct proc *p) 936 { 937 int i; 938 struct sigacts *ps; 939 940 PROC_LOCK(p); 941 ps = p->p_sigacts; 942 mtx_lock(&ps->ps_mtx); 943 for (i = 1; i <= NSIG; i++) { 944 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 945 SIGADDSET(ps->ps_sigignore, i); 946 } 947 } 948 mtx_unlock(&ps->ps_mtx); 949 PROC_UNLOCK(p); 950 } 951 952 /* 953 * Reset specified signal to the default disposition. 954 */ 955 static void 956 sigdflt(struct sigacts *ps, int sig) 957 { 958 959 mtx_assert(&ps->ps_mtx, MA_OWNED); 960 SIGDELSET(ps->ps_sigcatch, sig); 961 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 962 SIGADDSET(ps->ps_sigignore, sig); 963 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 964 SIGDELSET(ps->ps_siginfo, sig); 965 } 966 967 /* 968 * Reset signals for an exec of the specified process. 969 */ 970 void 971 execsigs(struct proc *p) 972 { 973 sigset_t osigignore; 974 struct sigacts *ps; 975 int sig; 976 struct thread *td; 977 978 /* 979 * Reset caught signals. Held signals remain held 980 * through td_sigmask (unless they were caught, 981 * and are now ignored by default). 982 */ 983 PROC_LOCK_ASSERT(p, MA_OWNED); 984 ps = p->p_sigacts; 985 mtx_lock(&ps->ps_mtx); 986 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 987 sig = sig_ffs(&ps->ps_sigcatch); 988 sigdflt(ps, sig); 989 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 990 sigqueue_delete_proc(p, sig); 991 } 992 993 /* 994 * As CloudABI processes cannot modify signal handlers, fully 995 * reset all signals to their default behavior. Do ignore 996 * SIGPIPE, as it would otherwise be impossible to recover from 997 * writes to broken pipes and sockets. 998 */ 999 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1000 osigignore = ps->ps_sigignore; 1001 while (SIGNOTEMPTY(osigignore)) { 1002 sig = sig_ffs(&osigignore); 1003 SIGDELSET(osigignore, sig); 1004 if (sig != SIGPIPE) 1005 sigdflt(ps, sig); 1006 } 1007 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1008 } 1009 1010 /* 1011 * Reset stack state to the user stack. 1012 * Clear set of signals caught on the signal stack. 1013 */ 1014 td = curthread; 1015 MPASS(td->td_proc == p); 1016 td->td_sigstk.ss_flags = SS_DISABLE; 1017 td->td_sigstk.ss_size = 0; 1018 td->td_sigstk.ss_sp = 0; 1019 td->td_pflags &= ~TDP_ALTSTACK; 1020 /* 1021 * Reset no zombies if child dies flag as Solaris does. 1022 */ 1023 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1024 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1025 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1026 mtx_unlock(&ps->ps_mtx); 1027 } 1028 1029 /* 1030 * kern_sigprocmask() 1031 * 1032 * Manipulate signal mask. 1033 */ 1034 int 1035 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1036 int flags) 1037 { 1038 sigset_t new_block, oset1; 1039 struct proc *p; 1040 int error; 1041 1042 p = td->td_proc; 1043 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1044 PROC_LOCK_ASSERT(p, MA_OWNED); 1045 else 1046 PROC_LOCK(p); 1047 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1048 ? MA_OWNED : MA_NOTOWNED); 1049 if (oset != NULL) 1050 *oset = td->td_sigmask; 1051 1052 error = 0; 1053 if (set != NULL) { 1054 switch (how) { 1055 case SIG_BLOCK: 1056 SIG_CANTMASK(*set); 1057 oset1 = td->td_sigmask; 1058 SIGSETOR(td->td_sigmask, *set); 1059 new_block = td->td_sigmask; 1060 SIGSETNAND(new_block, oset1); 1061 break; 1062 case SIG_UNBLOCK: 1063 SIGSETNAND(td->td_sigmask, *set); 1064 signotify(td); 1065 goto out; 1066 case SIG_SETMASK: 1067 SIG_CANTMASK(*set); 1068 oset1 = td->td_sigmask; 1069 if (flags & SIGPROCMASK_OLD) 1070 SIGSETLO(td->td_sigmask, *set); 1071 else 1072 td->td_sigmask = *set; 1073 new_block = td->td_sigmask; 1074 SIGSETNAND(new_block, oset1); 1075 signotify(td); 1076 break; 1077 default: 1078 error = EINVAL; 1079 goto out; 1080 } 1081 1082 /* 1083 * The new_block set contains signals that were not previously 1084 * blocked, but are blocked now. 1085 * 1086 * In case we block any signal that was not previously blocked 1087 * for td, and process has the signal pending, try to schedule 1088 * signal delivery to some thread that does not block the 1089 * signal, possibly waking it up. 1090 */ 1091 if (p->p_numthreads != 1) 1092 reschedule_signals(p, new_block, flags); 1093 } 1094 1095 out: 1096 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1097 PROC_UNLOCK(p); 1098 return (error); 1099 } 1100 1101 #ifndef _SYS_SYSPROTO_H_ 1102 struct sigprocmask_args { 1103 int how; 1104 const sigset_t *set; 1105 sigset_t *oset; 1106 }; 1107 #endif 1108 int 1109 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1110 { 1111 sigset_t set, oset; 1112 sigset_t *setp, *osetp; 1113 int error; 1114 1115 setp = (uap->set != NULL) ? &set : NULL; 1116 osetp = (uap->oset != NULL) ? &oset : NULL; 1117 if (setp) { 1118 error = copyin(uap->set, setp, sizeof(set)); 1119 if (error) 1120 return (error); 1121 } 1122 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1123 if (osetp && !error) { 1124 error = copyout(osetp, uap->oset, sizeof(oset)); 1125 } 1126 return (error); 1127 } 1128 1129 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1130 #ifndef _SYS_SYSPROTO_H_ 1131 struct osigprocmask_args { 1132 int how; 1133 osigset_t mask; 1134 }; 1135 #endif 1136 int 1137 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1138 { 1139 sigset_t set, oset; 1140 int error; 1141 1142 OSIG2SIG(uap->mask, set); 1143 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1144 SIG2OSIG(oset, td->td_retval[0]); 1145 return (error); 1146 } 1147 #endif /* COMPAT_43 */ 1148 1149 int 1150 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1151 { 1152 ksiginfo_t ksi; 1153 sigset_t set; 1154 int error; 1155 1156 error = copyin(uap->set, &set, sizeof(set)); 1157 if (error) { 1158 td->td_retval[0] = error; 1159 return (0); 1160 } 1161 1162 error = kern_sigtimedwait(td, set, &ksi, NULL); 1163 if (error) { 1164 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1165 error = ERESTART; 1166 if (error == ERESTART) 1167 return (error); 1168 td->td_retval[0] = error; 1169 return (0); 1170 } 1171 1172 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1173 td->td_retval[0] = error; 1174 return (0); 1175 } 1176 1177 int 1178 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1179 { 1180 struct timespec ts; 1181 struct timespec *timeout; 1182 sigset_t set; 1183 ksiginfo_t ksi; 1184 int error; 1185 1186 if (uap->timeout) { 1187 error = copyin(uap->timeout, &ts, sizeof(ts)); 1188 if (error) 1189 return (error); 1190 1191 timeout = &ts; 1192 } else 1193 timeout = NULL; 1194 1195 error = copyin(uap->set, &set, sizeof(set)); 1196 if (error) 1197 return (error); 1198 1199 error = kern_sigtimedwait(td, set, &ksi, timeout); 1200 if (error) 1201 return (error); 1202 1203 if (uap->info) 1204 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1205 1206 if (error == 0) 1207 td->td_retval[0] = ksi.ksi_signo; 1208 return (error); 1209 } 1210 1211 int 1212 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1213 { 1214 ksiginfo_t ksi; 1215 sigset_t set; 1216 int error; 1217 1218 error = copyin(uap->set, &set, sizeof(set)); 1219 if (error) 1220 return (error); 1221 1222 error = kern_sigtimedwait(td, set, &ksi, NULL); 1223 if (error) 1224 return (error); 1225 1226 if (uap->info) 1227 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1228 1229 if (error == 0) 1230 td->td_retval[0] = ksi.ksi_signo; 1231 return (error); 1232 } 1233 1234 static void 1235 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1236 { 1237 struct thread *thr; 1238 1239 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1240 if (thr == td) 1241 thr->td_si = *si; 1242 else 1243 thr->td_si.si_signo = 0; 1244 } 1245 } 1246 1247 int 1248 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1249 struct timespec *timeout) 1250 { 1251 struct sigacts *ps; 1252 sigset_t saved_mask, new_block; 1253 struct proc *p; 1254 int error, sig, timo, timevalid = 0; 1255 struct timespec rts, ets, ts; 1256 struct timeval tv; 1257 1258 p = td->td_proc; 1259 error = 0; 1260 ets.tv_sec = 0; 1261 ets.tv_nsec = 0; 1262 1263 if (timeout != NULL) { 1264 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1265 timevalid = 1; 1266 getnanouptime(&rts); 1267 ets = rts; 1268 timespecadd(&ets, timeout); 1269 } 1270 } 1271 ksiginfo_init(ksi); 1272 /* Some signals can not be waited for. */ 1273 SIG_CANTMASK(waitset); 1274 ps = p->p_sigacts; 1275 PROC_LOCK(p); 1276 saved_mask = td->td_sigmask; 1277 SIGSETNAND(td->td_sigmask, waitset); 1278 for (;;) { 1279 mtx_lock(&ps->ps_mtx); 1280 sig = cursig(td); 1281 mtx_unlock(&ps->ps_mtx); 1282 KASSERT(sig >= 0, ("sig %d", sig)); 1283 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1284 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1285 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1286 error = 0; 1287 break; 1288 } 1289 } 1290 1291 if (error != 0) 1292 break; 1293 1294 /* 1295 * POSIX says this must be checked after looking for pending 1296 * signals. 1297 */ 1298 if (timeout != NULL) { 1299 if (!timevalid) { 1300 error = EINVAL; 1301 break; 1302 } 1303 getnanouptime(&rts); 1304 if (timespeccmp(&rts, &ets, >=)) { 1305 error = EAGAIN; 1306 break; 1307 } 1308 ts = ets; 1309 timespecsub(&ts, &rts); 1310 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1311 timo = tvtohz(&tv); 1312 } else { 1313 timo = 0; 1314 } 1315 1316 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1317 1318 if (timeout != NULL) { 1319 if (error == ERESTART) { 1320 /* Timeout can not be restarted. */ 1321 error = EINTR; 1322 } else if (error == EAGAIN) { 1323 /* We will calculate timeout by ourself. */ 1324 error = 0; 1325 } 1326 } 1327 } 1328 1329 new_block = saved_mask; 1330 SIGSETNAND(new_block, td->td_sigmask); 1331 td->td_sigmask = saved_mask; 1332 /* 1333 * Fewer signals can be delivered to us, reschedule signal 1334 * notification. 1335 */ 1336 if (p->p_numthreads != 1) 1337 reschedule_signals(p, new_block, 0); 1338 1339 if (error == 0) { 1340 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1341 1342 if (ksi->ksi_code == SI_TIMER) 1343 itimer_accept(p, ksi->ksi_timerid, ksi); 1344 1345 #ifdef KTRACE 1346 if (KTRPOINT(td, KTR_PSIG)) { 1347 sig_t action; 1348 1349 mtx_lock(&ps->ps_mtx); 1350 action = ps->ps_sigact[_SIG_IDX(sig)]; 1351 mtx_unlock(&ps->ps_mtx); 1352 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1353 } 1354 #endif 1355 if (sig == SIGKILL) { 1356 proc_td_siginfo_capture(td, &ksi->ksi_info); 1357 sigexit(td, sig); 1358 } 1359 } 1360 PROC_UNLOCK(p); 1361 return (error); 1362 } 1363 1364 #ifndef _SYS_SYSPROTO_H_ 1365 struct sigpending_args { 1366 sigset_t *set; 1367 }; 1368 #endif 1369 int 1370 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1371 { 1372 struct proc *p = td->td_proc; 1373 sigset_t pending; 1374 1375 PROC_LOCK(p); 1376 pending = p->p_sigqueue.sq_signals; 1377 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1378 PROC_UNLOCK(p); 1379 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1380 } 1381 1382 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigpending_args { 1385 int dummy; 1386 }; 1387 #endif 1388 int 1389 osigpending(struct thread *td, struct osigpending_args *uap) 1390 { 1391 struct proc *p = td->td_proc; 1392 sigset_t pending; 1393 1394 PROC_LOCK(p); 1395 pending = p->p_sigqueue.sq_signals; 1396 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1397 PROC_UNLOCK(p); 1398 SIG2OSIG(pending, td->td_retval[0]); 1399 return (0); 1400 } 1401 #endif /* COMPAT_43 */ 1402 1403 #if defined(COMPAT_43) 1404 /* 1405 * Generalized interface signal handler, 4.3-compatible. 1406 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigvec_args { 1409 int signum; 1410 struct sigvec *nsv; 1411 struct sigvec *osv; 1412 }; 1413 #endif 1414 /* ARGSUSED */ 1415 int 1416 osigvec(struct thread *td, struct osigvec_args *uap) 1417 { 1418 struct sigvec vec; 1419 struct sigaction nsa, osa; 1420 struct sigaction *nsap, *osap; 1421 int error; 1422 1423 if (uap->signum <= 0 || uap->signum >= ONSIG) 1424 return (EINVAL); 1425 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1426 osap = (uap->osv != NULL) ? &osa : NULL; 1427 if (nsap) { 1428 error = copyin(uap->nsv, &vec, sizeof(vec)); 1429 if (error) 1430 return (error); 1431 nsap->sa_handler = vec.sv_handler; 1432 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1433 nsap->sa_flags = vec.sv_flags; 1434 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1435 } 1436 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1437 if (osap && !error) { 1438 vec.sv_handler = osap->sa_handler; 1439 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1440 vec.sv_flags = osap->sa_flags; 1441 vec.sv_flags &= ~SA_NOCLDWAIT; 1442 vec.sv_flags ^= SA_RESTART; 1443 error = copyout(&vec, uap->osv, sizeof(vec)); 1444 } 1445 return (error); 1446 } 1447 1448 #ifndef _SYS_SYSPROTO_H_ 1449 struct osigblock_args { 1450 int mask; 1451 }; 1452 #endif 1453 int 1454 osigblock(struct thread *td, struct osigblock_args *uap) 1455 { 1456 sigset_t set, oset; 1457 1458 OSIG2SIG(uap->mask, set); 1459 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1460 SIG2OSIG(oset, td->td_retval[0]); 1461 return (0); 1462 } 1463 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct osigsetmask_args { 1466 int mask; 1467 }; 1468 #endif 1469 int 1470 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1471 { 1472 sigset_t set, oset; 1473 1474 OSIG2SIG(uap->mask, set); 1475 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1476 SIG2OSIG(oset, td->td_retval[0]); 1477 return (0); 1478 } 1479 #endif /* COMPAT_43 */ 1480 1481 /* 1482 * Suspend calling thread until signal, providing mask to be set in the 1483 * meantime. 1484 */ 1485 #ifndef _SYS_SYSPROTO_H_ 1486 struct sigsuspend_args { 1487 const sigset_t *sigmask; 1488 }; 1489 #endif 1490 /* ARGSUSED */ 1491 int 1492 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1493 { 1494 sigset_t mask; 1495 int error; 1496 1497 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1498 if (error) 1499 return (error); 1500 return (kern_sigsuspend(td, mask)); 1501 } 1502 1503 int 1504 kern_sigsuspend(struct thread *td, sigset_t mask) 1505 { 1506 struct proc *p = td->td_proc; 1507 int has_sig, sig; 1508 1509 /* 1510 * When returning from sigsuspend, we want 1511 * the old mask to be restored after the 1512 * signal handler has finished. Thus, we 1513 * save it here and mark the sigacts structure 1514 * to indicate this. 1515 */ 1516 PROC_LOCK(p); 1517 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1518 SIGPROCMASK_PROC_LOCKED); 1519 td->td_pflags |= TDP_OLDMASK; 1520 1521 /* 1522 * Process signals now. Otherwise, we can get spurious wakeup 1523 * due to signal entered process queue, but delivered to other 1524 * thread. But sigsuspend should return only on signal 1525 * delivery. 1526 */ 1527 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1528 for (has_sig = 0; !has_sig;) { 1529 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1530 0) == 0) 1531 /* void */; 1532 thread_suspend_check(0); 1533 mtx_lock(&p->p_sigacts->ps_mtx); 1534 while ((sig = cursig(td)) != 0) { 1535 KASSERT(sig >= 0, ("sig %d", sig)); 1536 has_sig += postsig(sig); 1537 } 1538 mtx_unlock(&p->p_sigacts->ps_mtx); 1539 } 1540 PROC_UNLOCK(p); 1541 td->td_errno = EINTR; 1542 td->td_pflags |= TDP_NERRNO; 1543 return (EJUSTRETURN); 1544 } 1545 1546 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1547 /* 1548 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1549 * convention: libc stub passes mask, not pointer, to save a copyin. 1550 */ 1551 #ifndef _SYS_SYSPROTO_H_ 1552 struct osigsuspend_args { 1553 osigset_t mask; 1554 }; 1555 #endif 1556 /* ARGSUSED */ 1557 int 1558 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1559 { 1560 sigset_t mask; 1561 1562 OSIG2SIG(uap->mask, mask); 1563 return (kern_sigsuspend(td, mask)); 1564 } 1565 #endif /* COMPAT_43 */ 1566 1567 #if defined(COMPAT_43) 1568 #ifndef _SYS_SYSPROTO_H_ 1569 struct osigstack_args { 1570 struct sigstack *nss; 1571 struct sigstack *oss; 1572 }; 1573 #endif 1574 /* ARGSUSED */ 1575 int 1576 osigstack(struct thread *td, struct osigstack_args *uap) 1577 { 1578 struct sigstack nss, oss; 1579 int error = 0; 1580 1581 if (uap->nss != NULL) { 1582 error = copyin(uap->nss, &nss, sizeof(nss)); 1583 if (error) 1584 return (error); 1585 } 1586 oss.ss_sp = td->td_sigstk.ss_sp; 1587 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1588 if (uap->nss != NULL) { 1589 td->td_sigstk.ss_sp = nss.ss_sp; 1590 td->td_sigstk.ss_size = 0; 1591 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1592 td->td_pflags |= TDP_ALTSTACK; 1593 } 1594 if (uap->oss != NULL) 1595 error = copyout(&oss, uap->oss, sizeof(oss)); 1596 1597 return (error); 1598 } 1599 #endif /* COMPAT_43 */ 1600 1601 #ifndef _SYS_SYSPROTO_H_ 1602 struct sigaltstack_args { 1603 stack_t *ss; 1604 stack_t *oss; 1605 }; 1606 #endif 1607 /* ARGSUSED */ 1608 int 1609 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1610 { 1611 stack_t ss, oss; 1612 int error; 1613 1614 if (uap->ss != NULL) { 1615 error = copyin(uap->ss, &ss, sizeof(ss)); 1616 if (error) 1617 return (error); 1618 } 1619 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1620 (uap->oss != NULL) ? &oss : NULL); 1621 if (error) 1622 return (error); 1623 if (uap->oss != NULL) 1624 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1625 return (error); 1626 } 1627 1628 int 1629 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1630 { 1631 struct proc *p = td->td_proc; 1632 int oonstack; 1633 1634 oonstack = sigonstack(cpu_getstack(td)); 1635 1636 if (oss != NULL) { 1637 *oss = td->td_sigstk; 1638 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1639 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1640 } 1641 1642 if (ss != NULL) { 1643 if (oonstack) 1644 return (EPERM); 1645 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1646 return (EINVAL); 1647 if (!(ss->ss_flags & SS_DISABLE)) { 1648 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1649 return (ENOMEM); 1650 1651 td->td_sigstk = *ss; 1652 td->td_pflags |= TDP_ALTSTACK; 1653 } else { 1654 td->td_pflags &= ~TDP_ALTSTACK; 1655 } 1656 } 1657 return (0); 1658 } 1659 1660 /* 1661 * Common code for kill process group/broadcast kill. 1662 * cp is calling process. 1663 */ 1664 static int 1665 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1666 { 1667 struct proc *p; 1668 struct pgrp *pgrp; 1669 int err; 1670 int ret; 1671 1672 ret = ESRCH; 1673 if (all) { 1674 /* 1675 * broadcast 1676 */ 1677 sx_slock(&allproc_lock); 1678 FOREACH_PROC_IN_SYSTEM(p) { 1679 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1680 p == td->td_proc || p->p_state == PRS_NEW) { 1681 continue; 1682 } 1683 PROC_LOCK(p); 1684 err = p_cansignal(td, p, sig); 1685 if (err == 0) { 1686 if (sig) 1687 pksignal(p, sig, ksi); 1688 ret = err; 1689 } 1690 else if (ret == ESRCH) 1691 ret = err; 1692 PROC_UNLOCK(p); 1693 } 1694 sx_sunlock(&allproc_lock); 1695 } else { 1696 sx_slock(&proctree_lock); 1697 if (pgid == 0) { 1698 /* 1699 * zero pgid means send to my process group. 1700 */ 1701 pgrp = td->td_proc->p_pgrp; 1702 PGRP_LOCK(pgrp); 1703 } else { 1704 pgrp = pgfind(pgid); 1705 if (pgrp == NULL) { 1706 sx_sunlock(&proctree_lock); 1707 return (ESRCH); 1708 } 1709 } 1710 sx_sunlock(&proctree_lock); 1711 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1712 PROC_LOCK(p); 1713 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1714 p->p_state == PRS_NEW) { 1715 PROC_UNLOCK(p); 1716 continue; 1717 } 1718 err = p_cansignal(td, p, sig); 1719 if (err == 0) { 1720 if (sig) 1721 pksignal(p, sig, ksi); 1722 ret = err; 1723 } 1724 else if (ret == ESRCH) 1725 ret = err; 1726 PROC_UNLOCK(p); 1727 } 1728 PGRP_UNLOCK(pgrp); 1729 } 1730 return (ret); 1731 } 1732 1733 #ifndef _SYS_SYSPROTO_H_ 1734 struct kill_args { 1735 int pid; 1736 int signum; 1737 }; 1738 #endif 1739 /* ARGSUSED */ 1740 int 1741 sys_kill(struct thread *td, struct kill_args *uap) 1742 { 1743 ksiginfo_t ksi; 1744 struct proc *p; 1745 int error; 1746 1747 /* 1748 * A process in capability mode can send signals only to himself. 1749 * The main rationale behind this is that abort(3) is implemented as 1750 * kill(getpid(), SIGABRT). 1751 */ 1752 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1753 return (ECAPMODE); 1754 1755 AUDIT_ARG_SIGNUM(uap->signum); 1756 AUDIT_ARG_PID(uap->pid); 1757 if ((u_int)uap->signum > _SIG_MAXSIG) 1758 return (EINVAL); 1759 1760 ksiginfo_init(&ksi); 1761 ksi.ksi_signo = uap->signum; 1762 ksi.ksi_code = SI_USER; 1763 ksi.ksi_pid = td->td_proc->p_pid; 1764 ksi.ksi_uid = td->td_ucred->cr_ruid; 1765 1766 if (uap->pid > 0) { 1767 /* kill single process */ 1768 if ((p = pfind_any(uap->pid)) == NULL) 1769 return (ESRCH); 1770 AUDIT_ARG_PROCESS(p); 1771 error = p_cansignal(td, p, uap->signum); 1772 if (error == 0 && uap->signum) 1773 pksignal(p, uap->signum, &ksi); 1774 PROC_UNLOCK(p); 1775 return (error); 1776 } 1777 switch (uap->pid) { 1778 case -1: /* broadcast signal */ 1779 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1780 case 0: /* signal own process group */ 1781 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1782 default: /* negative explicit process group */ 1783 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1784 } 1785 /* NOTREACHED */ 1786 } 1787 1788 int 1789 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1790 { 1791 struct proc *p; 1792 int error; 1793 1794 AUDIT_ARG_SIGNUM(uap->signum); 1795 AUDIT_ARG_FD(uap->fd); 1796 if ((u_int)uap->signum > _SIG_MAXSIG) 1797 return (EINVAL); 1798 1799 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1800 if (error) 1801 return (error); 1802 AUDIT_ARG_PROCESS(p); 1803 error = p_cansignal(td, p, uap->signum); 1804 if (error == 0 && uap->signum) 1805 kern_psignal(p, uap->signum); 1806 PROC_UNLOCK(p); 1807 return (error); 1808 } 1809 1810 #if defined(COMPAT_43) 1811 #ifndef _SYS_SYSPROTO_H_ 1812 struct okillpg_args { 1813 int pgid; 1814 int signum; 1815 }; 1816 #endif 1817 /* ARGSUSED */ 1818 int 1819 okillpg(struct thread *td, struct okillpg_args *uap) 1820 { 1821 ksiginfo_t ksi; 1822 1823 AUDIT_ARG_SIGNUM(uap->signum); 1824 AUDIT_ARG_PID(uap->pgid); 1825 if ((u_int)uap->signum > _SIG_MAXSIG) 1826 return (EINVAL); 1827 1828 ksiginfo_init(&ksi); 1829 ksi.ksi_signo = uap->signum; 1830 ksi.ksi_code = SI_USER; 1831 ksi.ksi_pid = td->td_proc->p_pid; 1832 ksi.ksi_uid = td->td_ucred->cr_ruid; 1833 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1834 } 1835 #endif /* COMPAT_43 */ 1836 1837 #ifndef _SYS_SYSPROTO_H_ 1838 struct sigqueue_args { 1839 pid_t pid; 1840 int signum; 1841 /* union sigval */ void *value; 1842 }; 1843 #endif 1844 int 1845 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1846 { 1847 union sigval sv; 1848 1849 sv.sival_ptr = uap->value; 1850 1851 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1852 } 1853 1854 int 1855 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1856 { 1857 ksiginfo_t ksi; 1858 struct proc *p; 1859 int error; 1860 1861 if ((u_int)signum > _SIG_MAXSIG) 1862 return (EINVAL); 1863 1864 /* 1865 * Specification says sigqueue can only send signal to 1866 * single process. 1867 */ 1868 if (pid <= 0) 1869 return (EINVAL); 1870 1871 if ((p = pfind_any(pid)) == NULL) 1872 return (ESRCH); 1873 error = p_cansignal(td, p, signum); 1874 if (error == 0 && signum != 0) { 1875 ksiginfo_init(&ksi); 1876 ksi.ksi_flags = KSI_SIGQ; 1877 ksi.ksi_signo = signum; 1878 ksi.ksi_code = SI_QUEUE; 1879 ksi.ksi_pid = td->td_proc->p_pid; 1880 ksi.ksi_uid = td->td_ucred->cr_ruid; 1881 ksi.ksi_value = *value; 1882 error = pksignal(p, ksi.ksi_signo, &ksi); 1883 } 1884 PROC_UNLOCK(p); 1885 return (error); 1886 } 1887 1888 /* 1889 * Send a signal to a process group. 1890 */ 1891 void 1892 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1893 { 1894 struct pgrp *pgrp; 1895 1896 if (pgid != 0) { 1897 sx_slock(&proctree_lock); 1898 pgrp = pgfind(pgid); 1899 sx_sunlock(&proctree_lock); 1900 if (pgrp != NULL) { 1901 pgsignal(pgrp, sig, 0, ksi); 1902 PGRP_UNLOCK(pgrp); 1903 } 1904 } 1905 } 1906 1907 /* 1908 * Send a signal to a process group. If checktty is 1, 1909 * limit to members which have a controlling terminal. 1910 */ 1911 void 1912 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1913 { 1914 struct proc *p; 1915 1916 if (pgrp) { 1917 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1918 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1919 PROC_LOCK(p); 1920 if (p->p_state == PRS_NORMAL && 1921 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1922 pksignal(p, sig, ksi); 1923 PROC_UNLOCK(p); 1924 } 1925 } 1926 } 1927 1928 1929 /* 1930 * Recalculate the signal mask and reset the signal disposition after 1931 * usermode frame for delivery is formed. Should be called after 1932 * mach-specific routine, because sysent->sv_sendsig() needs correct 1933 * ps_siginfo and signal mask. 1934 */ 1935 static void 1936 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1937 { 1938 sigset_t mask; 1939 1940 mtx_assert(&ps->ps_mtx, MA_OWNED); 1941 td->td_ru.ru_nsignals++; 1942 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1943 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1944 SIGADDSET(mask, sig); 1945 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1946 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1947 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1948 sigdflt(ps, sig); 1949 } 1950 1951 1952 /* 1953 * Send a signal caused by a trap to the current thread. If it will be 1954 * caught immediately, deliver it with correct code. Otherwise, post it 1955 * normally. 1956 */ 1957 void 1958 trapsignal(struct thread *td, ksiginfo_t *ksi) 1959 { 1960 struct sigacts *ps; 1961 struct proc *p; 1962 int sig; 1963 int code; 1964 1965 p = td->td_proc; 1966 sig = ksi->ksi_signo; 1967 code = ksi->ksi_code; 1968 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1969 1970 PROC_LOCK(p); 1971 ps = p->p_sigacts; 1972 mtx_lock(&ps->ps_mtx); 1973 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1974 !SIGISMEMBER(td->td_sigmask, sig)) { 1975 #ifdef KTRACE 1976 if (KTRPOINT(curthread, KTR_PSIG)) 1977 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1978 &td->td_sigmask, code); 1979 #endif 1980 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1981 ksi, &td->td_sigmask); 1982 postsig_done(sig, td, ps); 1983 mtx_unlock(&ps->ps_mtx); 1984 } else { 1985 /* 1986 * Avoid a possible infinite loop if the thread 1987 * masking the signal or process is ignoring the 1988 * signal. 1989 */ 1990 if (kern_forcesigexit && 1991 (SIGISMEMBER(td->td_sigmask, sig) || 1992 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1993 SIGDELSET(td->td_sigmask, sig); 1994 SIGDELSET(ps->ps_sigcatch, sig); 1995 SIGDELSET(ps->ps_sigignore, sig); 1996 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1997 } 1998 mtx_unlock(&ps->ps_mtx); 1999 p->p_code = code; /* XXX for core dump/debugger */ 2000 p->p_sig = sig; /* XXX to verify code */ 2001 tdsendsignal(p, td, sig, ksi); 2002 } 2003 PROC_UNLOCK(p); 2004 } 2005 2006 static struct thread * 2007 sigtd(struct proc *p, int sig, int prop) 2008 { 2009 struct thread *td, *signal_td; 2010 2011 PROC_LOCK_ASSERT(p, MA_OWNED); 2012 2013 /* 2014 * Check if current thread can handle the signal without 2015 * switching context to another thread. 2016 */ 2017 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2018 return (curthread); 2019 signal_td = NULL; 2020 FOREACH_THREAD_IN_PROC(p, td) { 2021 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2022 signal_td = td; 2023 break; 2024 } 2025 } 2026 if (signal_td == NULL) 2027 signal_td = FIRST_THREAD_IN_PROC(p); 2028 return (signal_td); 2029 } 2030 2031 /* 2032 * Send the signal to the process. If the signal has an action, the action 2033 * is usually performed by the target process rather than the caller; we add 2034 * the signal to the set of pending signals for the process. 2035 * 2036 * Exceptions: 2037 * o When a stop signal is sent to a sleeping process that takes the 2038 * default action, the process is stopped without awakening it. 2039 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2040 * regardless of the signal action (eg, blocked or ignored). 2041 * 2042 * Other ignored signals are discarded immediately. 2043 * 2044 * NB: This function may be entered from the debugger via the "kill" DDB 2045 * command. There is little that can be done to mitigate the possibly messy 2046 * side effects of this unwise possibility. 2047 */ 2048 void 2049 kern_psignal(struct proc *p, int sig) 2050 { 2051 ksiginfo_t ksi; 2052 2053 ksiginfo_init(&ksi); 2054 ksi.ksi_signo = sig; 2055 ksi.ksi_code = SI_KERNEL; 2056 (void) tdsendsignal(p, NULL, sig, &ksi); 2057 } 2058 2059 int 2060 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2061 { 2062 2063 return (tdsendsignal(p, NULL, sig, ksi)); 2064 } 2065 2066 /* Utility function for finding a thread to send signal event to. */ 2067 int 2068 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2069 { 2070 struct thread *td; 2071 2072 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2073 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2074 if (td == NULL) 2075 return (ESRCH); 2076 *ttd = td; 2077 } else { 2078 *ttd = NULL; 2079 PROC_LOCK(p); 2080 } 2081 return (0); 2082 } 2083 2084 void 2085 tdsignal(struct thread *td, int sig) 2086 { 2087 ksiginfo_t ksi; 2088 2089 ksiginfo_init(&ksi); 2090 ksi.ksi_signo = sig; 2091 ksi.ksi_code = SI_KERNEL; 2092 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2093 } 2094 2095 void 2096 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2097 { 2098 2099 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2100 } 2101 2102 int 2103 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2104 { 2105 sig_t action; 2106 sigqueue_t *sigqueue; 2107 int prop; 2108 struct sigacts *ps; 2109 int intrval; 2110 int ret = 0; 2111 int wakeup_swapper; 2112 2113 MPASS(td == NULL || p == td->td_proc); 2114 PROC_LOCK_ASSERT(p, MA_OWNED); 2115 2116 if (!_SIG_VALID(sig)) 2117 panic("%s(): invalid signal %d", __func__, sig); 2118 2119 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2120 2121 /* 2122 * IEEE Std 1003.1-2001: return success when killing a zombie. 2123 */ 2124 if (p->p_state == PRS_ZOMBIE) { 2125 if (ksi && (ksi->ksi_flags & KSI_INS)) 2126 ksiginfo_tryfree(ksi); 2127 return (ret); 2128 } 2129 2130 ps = p->p_sigacts; 2131 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2132 prop = sigprop(sig); 2133 2134 if (td == NULL) { 2135 td = sigtd(p, sig, prop); 2136 sigqueue = &p->p_sigqueue; 2137 } else 2138 sigqueue = &td->td_sigqueue; 2139 2140 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2141 2142 /* 2143 * If the signal is being ignored, 2144 * then we forget about it immediately. 2145 * (Note: we don't set SIGCONT in ps_sigignore, 2146 * and if it is set to SIG_IGN, 2147 * action will be SIG_DFL here.) 2148 */ 2149 mtx_lock(&ps->ps_mtx); 2150 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2151 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2152 2153 mtx_unlock(&ps->ps_mtx); 2154 if (ksi && (ksi->ksi_flags & KSI_INS)) 2155 ksiginfo_tryfree(ksi); 2156 return (ret); 2157 } 2158 if (SIGISMEMBER(td->td_sigmask, sig)) 2159 action = SIG_HOLD; 2160 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2161 action = SIG_CATCH; 2162 else 2163 action = SIG_DFL; 2164 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2165 intrval = EINTR; 2166 else 2167 intrval = ERESTART; 2168 mtx_unlock(&ps->ps_mtx); 2169 2170 if (prop & SIGPROP_CONT) 2171 sigqueue_delete_stopmask_proc(p); 2172 else if (prop & SIGPROP_STOP) { 2173 /* 2174 * If sending a tty stop signal to a member of an orphaned 2175 * process group, discard the signal here if the action 2176 * is default; don't stop the process below if sleeping, 2177 * and don't clear any pending SIGCONT. 2178 */ 2179 if ((prop & SIGPROP_TTYSTOP) && 2180 (p->p_pgrp->pg_jobc == 0) && 2181 (action == SIG_DFL)) { 2182 if (ksi && (ksi->ksi_flags & KSI_INS)) 2183 ksiginfo_tryfree(ksi); 2184 return (ret); 2185 } 2186 sigqueue_delete_proc(p, SIGCONT); 2187 if (p->p_flag & P_CONTINUED) { 2188 p->p_flag &= ~P_CONTINUED; 2189 PROC_LOCK(p->p_pptr); 2190 sigqueue_take(p->p_ksi); 2191 PROC_UNLOCK(p->p_pptr); 2192 } 2193 } 2194 2195 ret = sigqueue_add(sigqueue, sig, ksi); 2196 if (ret != 0) 2197 return (ret); 2198 signotify(td); 2199 /* 2200 * Defer further processing for signals which are held, 2201 * except that stopped processes must be continued by SIGCONT. 2202 */ 2203 if (action == SIG_HOLD && 2204 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2205 return (ret); 2206 2207 /* SIGKILL: Remove procfs STOPEVENTs. */ 2208 if (sig == SIGKILL) { 2209 /* from procfs_ioctl.c: PIOCBIC */ 2210 p->p_stops = 0; 2211 /* from procfs_ioctl.c: PIOCCONT */ 2212 p->p_step = 0; 2213 wakeup(&p->p_step); 2214 } 2215 /* 2216 * Some signals have a process-wide effect and a per-thread 2217 * component. Most processing occurs when the process next 2218 * tries to cross the user boundary, however there are some 2219 * times when processing needs to be done immediately, such as 2220 * waking up threads so that they can cross the user boundary. 2221 * We try to do the per-process part here. 2222 */ 2223 if (P_SHOULDSTOP(p)) { 2224 KASSERT(!(p->p_flag & P_WEXIT), 2225 ("signal to stopped but exiting process")); 2226 if (sig == SIGKILL) { 2227 /* 2228 * If traced process is already stopped, 2229 * then no further action is necessary. 2230 */ 2231 if (p->p_flag & P_TRACED) 2232 goto out; 2233 /* 2234 * SIGKILL sets process running. 2235 * It will die elsewhere. 2236 * All threads must be restarted. 2237 */ 2238 p->p_flag &= ~P_STOPPED_SIG; 2239 goto runfast; 2240 } 2241 2242 if (prop & SIGPROP_CONT) { 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 * If SIGCONT is default (or ignored), we continue the 2251 * process but don't leave the signal in sigqueue as 2252 * it has no further action. If SIGCONT is held, we 2253 * continue the process and leave the signal in 2254 * sigqueue. If the process catches SIGCONT, let it 2255 * handle the signal itself. If it isn't waiting on 2256 * an event, it goes back to run state. 2257 * Otherwise, process goes back to sleep state. 2258 */ 2259 p->p_flag &= ~P_STOPPED_SIG; 2260 PROC_SLOCK(p); 2261 if (p->p_numthreads == p->p_suspcount) { 2262 PROC_SUNLOCK(p); 2263 p->p_flag |= P_CONTINUED; 2264 p->p_xsig = SIGCONT; 2265 PROC_LOCK(p->p_pptr); 2266 childproc_continued(p); 2267 PROC_UNLOCK(p->p_pptr); 2268 PROC_SLOCK(p); 2269 } 2270 if (action == SIG_DFL) { 2271 thread_unsuspend(p); 2272 PROC_SUNLOCK(p); 2273 sigqueue_delete(sigqueue, sig); 2274 goto out; 2275 } 2276 if (action == SIG_CATCH) { 2277 /* 2278 * The process wants to catch it so it needs 2279 * to run at least one thread, but which one? 2280 */ 2281 PROC_SUNLOCK(p); 2282 goto runfast; 2283 } 2284 /* 2285 * The signal is not ignored or caught. 2286 */ 2287 thread_unsuspend(p); 2288 PROC_SUNLOCK(p); 2289 goto out; 2290 } 2291 2292 if (prop & SIGPROP_STOP) { 2293 /* 2294 * If traced process is already stopped, 2295 * then no further action is necessary. 2296 */ 2297 if (p->p_flag & P_TRACED) 2298 goto out; 2299 /* 2300 * Already stopped, don't need to stop again 2301 * (If we did the shell could get confused). 2302 * Just make sure the signal STOP bit set. 2303 */ 2304 p->p_flag |= P_STOPPED_SIG; 2305 sigqueue_delete(sigqueue, sig); 2306 goto out; 2307 } 2308 2309 /* 2310 * All other kinds of signals: 2311 * If a thread is sleeping interruptibly, simulate a 2312 * wakeup so that when it is continued it will be made 2313 * runnable and can look at the signal. However, don't make 2314 * the PROCESS runnable, leave it stopped. 2315 * It may run a bit until it hits a thread_suspend_check(). 2316 */ 2317 wakeup_swapper = 0; 2318 PROC_SLOCK(p); 2319 thread_lock(td); 2320 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2321 wakeup_swapper = sleepq_abort(td, intrval); 2322 thread_unlock(td); 2323 PROC_SUNLOCK(p); 2324 if (wakeup_swapper) 2325 kick_proc0(); 2326 goto out; 2327 /* 2328 * Mutexes are short lived. Threads waiting on them will 2329 * hit thread_suspend_check() soon. 2330 */ 2331 } else if (p->p_state == PRS_NORMAL) { 2332 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2333 tdsigwakeup(td, sig, action, intrval); 2334 goto out; 2335 } 2336 2337 MPASS(action == SIG_DFL); 2338 2339 if (prop & SIGPROP_STOP) { 2340 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2341 goto out; 2342 p->p_flag |= P_STOPPED_SIG; 2343 p->p_xsig = sig; 2344 PROC_SLOCK(p); 2345 wakeup_swapper = sig_suspend_threads(td, p, 1); 2346 if (p->p_numthreads == p->p_suspcount) { 2347 /* 2348 * only thread sending signal to another 2349 * process can reach here, if thread is sending 2350 * signal to its process, because thread does 2351 * not suspend itself here, p_numthreads 2352 * should never be equal to p_suspcount. 2353 */ 2354 thread_stopped(p); 2355 PROC_SUNLOCK(p); 2356 sigqueue_delete_proc(p, p->p_xsig); 2357 } else 2358 PROC_SUNLOCK(p); 2359 if (wakeup_swapper) 2360 kick_proc0(); 2361 goto out; 2362 } 2363 } else { 2364 /* Not in "NORMAL" state. discard the signal. */ 2365 sigqueue_delete(sigqueue, sig); 2366 goto out; 2367 } 2368 2369 /* 2370 * The process is not stopped so we need to apply the signal to all the 2371 * running threads. 2372 */ 2373 runfast: 2374 tdsigwakeup(td, sig, action, intrval); 2375 PROC_SLOCK(p); 2376 thread_unsuspend(p); 2377 PROC_SUNLOCK(p); 2378 out: 2379 /* If we jump here, proc slock should not be owned. */ 2380 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2381 return (ret); 2382 } 2383 2384 /* 2385 * The force of a signal has been directed against a single 2386 * thread. We need to see what we can do about knocking it 2387 * out of any sleep it may be in etc. 2388 */ 2389 static void 2390 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2391 { 2392 struct proc *p = td->td_proc; 2393 int prop; 2394 int wakeup_swapper; 2395 2396 wakeup_swapper = 0; 2397 PROC_LOCK_ASSERT(p, MA_OWNED); 2398 prop = sigprop(sig); 2399 2400 PROC_SLOCK(p); 2401 thread_lock(td); 2402 /* 2403 * Bring the priority of a thread up if we want it to get 2404 * killed in this lifetime. Be careful to avoid bumping the 2405 * priority of the idle thread, since we still allow to signal 2406 * kernel processes. 2407 */ 2408 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2409 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2410 sched_prio(td, PUSER); 2411 if (TD_ON_SLEEPQ(td)) { 2412 /* 2413 * If thread is sleeping uninterruptibly 2414 * we can't interrupt the sleep... the signal will 2415 * be noticed when the process returns through 2416 * trap() or syscall(). 2417 */ 2418 if ((td->td_flags & TDF_SINTR) == 0) 2419 goto out; 2420 /* 2421 * If SIGCONT is default (or ignored) and process is 2422 * asleep, we are finished; the process should not 2423 * be awakened. 2424 */ 2425 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2426 thread_unlock(td); 2427 PROC_SUNLOCK(p); 2428 sigqueue_delete(&p->p_sigqueue, sig); 2429 /* 2430 * It may be on either list in this state. 2431 * Remove from both for now. 2432 */ 2433 sigqueue_delete(&td->td_sigqueue, sig); 2434 return; 2435 } 2436 2437 /* 2438 * Don't awaken a sleeping thread for SIGSTOP if the 2439 * STOP signal is deferred. 2440 */ 2441 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2442 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2443 goto out; 2444 2445 /* 2446 * Give low priority threads a better chance to run. 2447 */ 2448 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2449 sched_prio(td, PUSER); 2450 2451 wakeup_swapper = sleepq_abort(td, intrval); 2452 } else { 2453 /* 2454 * Other states do nothing with the signal immediately, 2455 * other than kicking ourselves if we are running. 2456 * It will either never be noticed, or noticed very soon. 2457 */ 2458 #ifdef SMP 2459 if (TD_IS_RUNNING(td) && td != curthread) 2460 forward_signal(td); 2461 #endif 2462 } 2463 out: 2464 PROC_SUNLOCK(p); 2465 thread_unlock(td); 2466 if (wakeup_swapper) 2467 kick_proc0(); 2468 } 2469 2470 static int 2471 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2472 { 2473 struct thread *td2; 2474 int wakeup_swapper; 2475 2476 PROC_LOCK_ASSERT(p, MA_OWNED); 2477 PROC_SLOCK_ASSERT(p, MA_OWNED); 2478 MPASS(sending || td == curthread); 2479 2480 wakeup_swapper = 0; 2481 FOREACH_THREAD_IN_PROC(p, td2) { 2482 thread_lock(td2); 2483 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2484 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2485 (td2->td_flags & TDF_SINTR)) { 2486 if (td2->td_flags & TDF_SBDRY) { 2487 /* 2488 * Once a thread is asleep with 2489 * TDF_SBDRY and without TDF_SERESTART 2490 * or TDF_SEINTR set, it should never 2491 * become suspended due to this check. 2492 */ 2493 KASSERT(!TD_IS_SUSPENDED(td2), 2494 ("thread with deferred stops suspended")); 2495 if (TD_SBDRY_INTR(td2)) 2496 wakeup_swapper |= sleepq_abort(td2, 2497 TD_SBDRY_ERRNO(td2)); 2498 } else if (!TD_IS_SUSPENDED(td2)) { 2499 thread_suspend_one(td2); 2500 } 2501 } else if (!TD_IS_SUSPENDED(td2)) { 2502 if (sending || td != td2) 2503 td2->td_flags |= TDF_ASTPENDING; 2504 #ifdef SMP 2505 if (TD_IS_RUNNING(td2) && td2 != td) 2506 forward_signal(td2); 2507 #endif 2508 } 2509 thread_unlock(td2); 2510 } 2511 return (wakeup_swapper); 2512 } 2513 2514 /* 2515 * Stop the process for an event deemed interesting to the debugger. If si is 2516 * non-NULL, this is a signal exchange; the new signal requested by the 2517 * debugger will be returned for handling. If si is NULL, this is some other 2518 * type of interesting event. The debugger may request a signal be delivered in 2519 * that case as well, however it will be deferred until it can be handled. 2520 */ 2521 int 2522 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2523 { 2524 struct proc *p = td->td_proc; 2525 struct thread *td2; 2526 ksiginfo_t ksi; 2527 int prop; 2528 2529 PROC_LOCK_ASSERT(p, MA_OWNED); 2530 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2531 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2532 &p->p_mtx.lock_object, "Stopping for traced signal"); 2533 2534 td->td_xsig = sig; 2535 2536 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2537 td->td_dbgflags |= TDB_XSIG; 2538 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2539 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2540 PROC_SLOCK(p); 2541 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2542 if (P_KILLED(p)) { 2543 /* 2544 * Ensure that, if we've been PT_KILLed, the 2545 * exit status reflects that. Another thread 2546 * may also be in ptracestop(), having just 2547 * received the SIGKILL, but this thread was 2548 * unsuspended first. 2549 */ 2550 td->td_dbgflags &= ~TDB_XSIG; 2551 td->td_xsig = SIGKILL; 2552 p->p_ptevents = 0; 2553 break; 2554 } 2555 if (p->p_flag & P_SINGLE_EXIT && 2556 !(td->td_dbgflags & TDB_EXIT)) { 2557 /* 2558 * Ignore ptrace stops except for thread exit 2559 * events when the process exits. 2560 */ 2561 td->td_dbgflags &= ~TDB_XSIG; 2562 PROC_SUNLOCK(p); 2563 return (0); 2564 } 2565 2566 /* 2567 * Make wait(2) work. Ensure that right after the 2568 * attach, the thread which was decided to become the 2569 * leader of attach gets reported to the waiter. 2570 * Otherwise, just avoid overwriting another thread's 2571 * assignment to p_xthread. If another thread has 2572 * already set p_xthread, the current thread will get 2573 * a chance to report itself upon the next iteration. 2574 */ 2575 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2576 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2577 p->p_xthread == NULL)) { 2578 p->p_xsig = sig; 2579 p->p_xthread = td; 2580 td->td_dbgflags &= ~TDB_FSTP; 2581 p->p_flag2 &= ~P2_PTRACE_FSTP; 2582 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2583 sig_suspend_threads(td, p, 0); 2584 } 2585 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2586 td->td_dbgflags &= ~TDB_STOPATFORK; 2587 cv_broadcast(&p->p_dbgwait); 2588 } 2589 stopme: 2590 thread_suspend_switch(td, p); 2591 if (p->p_xthread == td) 2592 p->p_xthread = NULL; 2593 if (!(p->p_flag & P_TRACED)) 2594 break; 2595 if (td->td_dbgflags & TDB_SUSPEND) { 2596 if (p->p_flag & P_SINGLE_EXIT) 2597 break; 2598 goto stopme; 2599 } 2600 } 2601 PROC_SUNLOCK(p); 2602 } 2603 2604 if (si != NULL && sig == td->td_xsig) { 2605 /* Parent wants us to take the original signal unchanged. */ 2606 si->ksi_flags |= KSI_HEAD; 2607 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2608 si->ksi_signo = 0; 2609 } else if (td->td_xsig != 0) { 2610 /* 2611 * If parent wants us to take a new signal, then it will leave 2612 * it in td->td_xsig; otherwise we just look for signals again. 2613 */ 2614 ksiginfo_init(&ksi); 2615 ksi.ksi_signo = td->td_xsig; 2616 ksi.ksi_flags |= KSI_PTRACE; 2617 prop = sigprop(td->td_xsig); 2618 td2 = sigtd(p, td->td_xsig, prop); 2619 tdsendsignal(p, td2, td->td_xsig, &ksi); 2620 if (td != td2) 2621 return (0); 2622 } 2623 2624 return (td->td_xsig); 2625 } 2626 2627 static void 2628 reschedule_signals(struct proc *p, sigset_t block, int flags) 2629 { 2630 struct sigacts *ps; 2631 struct thread *td; 2632 int sig; 2633 2634 PROC_LOCK_ASSERT(p, MA_OWNED); 2635 ps = p->p_sigacts; 2636 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2637 MA_OWNED : MA_NOTOWNED); 2638 if (SIGISEMPTY(p->p_siglist)) 2639 return; 2640 SIGSETAND(block, p->p_siglist); 2641 while ((sig = sig_ffs(&block)) != 0) { 2642 SIGDELSET(block, sig); 2643 td = sigtd(p, sig, 0); 2644 signotify(td); 2645 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2646 mtx_lock(&ps->ps_mtx); 2647 if (p->p_flag & P_TRACED || 2648 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2649 !SIGISMEMBER(td->td_sigmask, sig))) 2650 tdsigwakeup(td, sig, SIG_CATCH, 2651 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2652 ERESTART)); 2653 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2654 mtx_unlock(&ps->ps_mtx); 2655 } 2656 } 2657 2658 void 2659 tdsigcleanup(struct thread *td) 2660 { 2661 struct proc *p; 2662 sigset_t unblocked; 2663 2664 p = td->td_proc; 2665 PROC_LOCK_ASSERT(p, MA_OWNED); 2666 2667 sigqueue_flush(&td->td_sigqueue); 2668 if (p->p_numthreads == 1) 2669 return; 2670 2671 /* 2672 * Since we cannot handle signals, notify signal post code 2673 * about this by filling the sigmask. 2674 * 2675 * Also, if needed, wake up thread(s) that do not block the 2676 * same signals as the exiting thread, since the thread might 2677 * have been selected for delivery and woken up. 2678 */ 2679 SIGFILLSET(unblocked); 2680 SIGSETNAND(unblocked, td->td_sigmask); 2681 SIGFILLSET(td->td_sigmask); 2682 reschedule_signals(p, unblocked, 0); 2683 2684 } 2685 2686 static int 2687 sigdeferstop_curr_flags(int cflags) 2688 { 2689 2690 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2691 (cflags & TDF_SBDRY) != 0); 2692 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2693 } 2694 2695 /* 2696 * Defer the delivery of SIGSTOP for the current thread, according to 2697 * the requested mode. Returns previous flags, which must be restored 2698 * by sigallowstop(). 2699 * 2700 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2701 * cleared by the current thread, which allow the lock-less read-only 2702 * accesses below. 2703 */ 2704 int 2705 sigdeferstop_impl(int mode) 2706 { 2707 struct thread *td; 2708 int cflags, nflags; 2709 2710 td = curthread; 2711 cflags = sigdeferstop_curr_flags(td->td_flags); 2712 switch (mode) { 2713 case SIGDEFERSTOP_NOP: 2714 nflags = cflags; 2715 break; 2716 case SIGDEFERSTOP_OFF: 2717 nflags = 0; 2718 break; 2719 case SIGDEFERSTOP_SILENT: 2720 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2721 break; 2722 case SIGDEFERSTOP_EINTR: 2723 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2724 break; 2725 case SIGDEFERSTOP_ERESTART: 2726 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2727 break; 2728 default: 2729 panic("sigdeferstop: invalid mode %x", mode); 2730 break; 2731 } 2732 if (cflags == nflags) 2733 return (SIGDEFERSTOP_VAL_NCHG); 2734 thread_lock(td); 2735 td->td_flags = (td->td_flags & ~cflags) | nflags; 2736 thread_unlock(td); 2737 return (cflags); 2738 } 2739 2740 /* 2741 * Restores the STOP handling mode, typically permitting the delivery 2742 * of SIGSTOP for the current thread. This does not immediately 2743 * suspend if a stop was posted. Instead, the thread will suspend 2744 * either via ast() or a subsequent interruptible sleep. 2745 */ 2746 void 2747 sigallowstop_impl(int prev) 2748 { 2749 struct thread *td; 2750 int cflags; 2751 2752 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2753 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2754 ("sigallowstop: incorrect previous mode %x", prev)); 2755 td = curthread; 2756 cflags = sigdeferstop_curr_flags(td->td_flags); 2757 if (cflags != prev) { 2758 thread_lock(td); 2759 td->td_flags = (td->td_flags & ~cflags) | prev; 2760 thread_unlock(td); 2761 } 2762 } 2763 2764 /* 2765 * If the current process has received a signal (should be caught or cause 2766 * termination, should interrupt current syscall), return the signal number. 2767 * Stop signals with default action are processed immediately, then cleared; 2768 * they aren't returned. This is checked after each entry to the system for 2769 * a syscall or trap (though this can usually be done without calling issignal 2770 * by checking the pending signal masks in cursig.) The normal call 2771 * sequence is 2772 * 2773 * while (sig = cursig(curthread)) 2774 * postsig(sig); 2775 */ 2776 static int 2777 issignal(struct thread *td) 2778 { 2779 struct proc *p; 2780 struct sigacts *ps; 2781 struct sigqueue *queue; 2782 sigset_t sigpending; 2783 ksiginfo_t ksi; 2784 int prop, sig, traced; 2785 2786 p = td->td_proc; 2787 ps = p->p_sigacts; 2788 mtx_assert(&ps->ps_mtx, MA_OWNED); 2789 PROC_LOCK_ASSERT(p, MA_OWNED); 2790 for (;;) { 2791 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2792 2793 sigpending = td->td_sigqueue.sq_signals; 2794 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2795 SIGSETNAND(sigpending, td->td_sigmask); 2796 2797 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2798 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2799 SIG_STOPSIGMASK(sigpending); 2800 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2801 return (0); 2802 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2803 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2804 SIGISMEMBER(sigpending, SIGSTOP)) { 2805 /* 2806 * If debugger just attached, always consume 2807 * SIGSTOP from ptrace(PT_ATTACH) first, to 2808 * execute the debugger attach ritual in 2809 * order. 2810 */ 2811 sig = SIGSTOP; 2812 td->td_dbgflags |= TDB_FSTP; 2813 } else { 2814 sig = sig_ffs(&sigpending); 2815 } 2816 2817 if (p->p_stops & S_SIG) { 2818 mtx_unlock(&ps->ps_mtx); 2819 stopevent(p, S_SIG, sig); 2820 mtx_lock(&ps->ps_mtx); 2821 } 2822 2823 /* 2824 * We should see pending but ignored signals 2825 * only if P_TRACED was on when they were posted. 2826 */ 2827 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2828 sigqueue_delete(&td->td_sigqueue, sig); 2829 sigqueue_delete(&p->p_sigqueue, sig); 2830 continue; 2831 } 2832 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2833 /* 2834 * If traced, always stop. 2835 * Remove old signal from queue before the stop. 2836 * XXX shrug off debugger, it causes siginfo to 2837 * be thrown away. 2838 */ 2839 queue = &td->td_sigqueue; 2840 ksiginfo_init(&ksi); 2841 if (sigqueue_get(queue, sig, &ksi) == 0) { 2842 queue = &p->p_sigqueue; 2843 sigqueue_get(queue, sig, &ksi); 2844 } 2845 td->td_si = ksi.ksi_info; 2846 2847 mtx_unlock(&ps->ps_mtx); 2848 sig = ptracestop(td, sig, &ksi); 2849 mtx_lock(&ps->ps_mtx); 2850 2851 /* 2852 * Keep looking if the debugger discarded or 2853 * replaced the signal. 2854 */ 2855 if (sig == 0) 2856 continue; 2857 2858 /* 2859 * If the signal became masked, re-queue it. 2860 */ 2861 if (SIGISMEMBER(td->td_sigmask, sig)) { 2862 ksi.ksi_flags |= KSI_HEAD; 2863 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2864 continue; 2865 } 2866 2867 /* 2868 * If the traced bit got turned off, requeue 2869 * the signal and go back up to the top to 2870 * rescan signals. This ensures that p_sig* 2871 * and p_sigact are consistent. 2872 */ 2873 if ((p->p_flag & P_TRACED) == 0) { 2874 ksi.ksi_flags |= KSI_HEAD; 2875 sigqueue_add(queue, sig, &ksi); 2876 continue; 2877 } 2878 } 2879 2880 prop = sigprop(sig); 2881 2882 /* 2883 * Decide whether the signal should be returned. 2884 * Return the signal's number, or fall through 2885 * to clear it from the pending mask. 2886 */ 2887 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2888 2889 case (intptr_t)SIG_DFL: 2890 /* 2891 * Don't take default actions on system processes. 2892 */ 2893 if (p->p_pid <= 1) { 2894 #ifdef DIAGNOSTIC 2895 /* 2896 * Are you sure you want to ignore SIGSEGV 2897 * in init? XXX 2898 */ 2899 printf("Process (pid %lu) got signal %d\n", 2900 (u_long)p->p_pid, sig); 2901 #endif 2902 break; /* == ignore */ 2903 } 2904 /* 2905 * If there is a pending stop signal to process with 2906 * default action, stop here, then clear the signal. 2907 * Traced or exiting processes should ignore stops. 2908 * Additionally, a member of an orphaned process group 2909 * should ignore tty stops. 2910 */ 2911 if (prop & SIGPROP_STOP) { 2912 if (p->p_flag & 2913 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2914 (p->p_pgrp->pg_jobc == 0 && 2915 prop & SIGPROP_TTYSTOP)) 2916 break; /* == ignore */ 2917 if (TD_SBDRY_INTR(td)) { 2918 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2919 ("lost TDF_SBDRY")); 2920 return (-1); 2921 } 2922 mtx_unlock(&ps->ps_mtx); 2923 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2924 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2925 sigqueue_delete(&td->td_sigqueue, sig); 2926 sigqueue_delete(&p->p_sigqueue, sig); 2927 p->p_flag |= P_STOPPED_SIG; 2928 p->p_xsig = sig; 2929 PROC_SLOCK(p); 2930 sig_suspend_threads(td, p, 0); 2931 thread_suspend_switch(td, p); 2932 PROC_SUNLOCK(p); 2933 mtx_lock(&ps->ps_mtx); 2934 goto next; 2935 } else if (prop & SIGPROP_IGNORE) { 2936 /* 2937 * Except for SIGCONT, shouldn't get here. 2938 * Default action is to ignore; drop it. 2939 */ 2940 break; /* == ignore */ 2941 } else 2942 return (sig); 2943 /*NOTREACHED*/ 2944 2945 case (intptr_t)SIG_IGN: 2946 /* 2947 * Masking above should prevent us ever trying 2948 * to take action on an ignored signal other 2949 * than SIGCONT, unless process is traced. 2950 */ 2951 if ((prop & SIGPROP_CONT) == 0 && 2952 (p->p_flag & P_TRACED) == 0) 2953 printf("issignal\n"); 2954 break; /* == ignore */ 2955 2956 default: 2957 /* 2958 * This signal has an action, let 2959 * postsig() process it. 2960 */ 2961 return (sig); 2962 } 2963 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2964 sigqueue_delete(&p->p_sigqueue, sig); 2965 next:; 2966 } 2967 /* NOTREACHED */ 2968 } 2969 2970 void 2971 thread_stopped(struct proc *p) 2972 { 2973 int n; 2974 2975 PROC_LOCK_ASSERT(p, MA_OWNED); 2976 PROC_SLOCK_ASSERT(p, MA_OWNED); 2977 n = p->p_suspcount; 2978 if (p == curproc) 2979 n++; 2980 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2981 PROC_SUNLOCK(p); 2982 p->p_flag &= ~P_WAITED; 2983 PROC_LOCK(p->p_pptr); 2984 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2985 CLD_TRAPPED : CLD_STOPPED); 2986 PROC_UNLOCK(p->p_pptr); 2987 PROC_SLOCK(p); 2988 } 2989 } 2990 2991 /* 2992 * Take the action for the specified signal 2993 * from the current set of pending signals. 2994 */ 2995 int 2996 postsig(int sig) 2997 { 2998 struct thread *td; 2999 struct proc *p; 3000 struct sigacts *ps; 3001 sig_t action; 3002 ksiginfo_t ksi; 3003 sigset_t returnmask; 3004 3005 KASSERT(sig != 0, ("postsig")); 3006 3007 td = curthread; 3008 p = td->td_proc; 3009 PROC_LOCK_ASSERT(p, MA_OWNED); 3010 ps = p->p_sigacts; 3011 mtx_assert(&ps->ps_mtx, MA_OWNED); 3012 ksiginfo_init(&ksi); 3013 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3014 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3015 return (0); 3016 ksi.ksi_signo = sig; 3017 if (ksi.ksi_code == SI_TIMER) 3018 itimer_accept(p, ksi.ksi_timerid, &ksi); 3019 action = ps->ps_sigact[_SIG_IDX(sig)]; 3020 #ifdef KTRACE 3021 if (KTRPOINT(td, KTR_PSIG)) 3022 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3023 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3024 #endif 3025 if ((p->p_stops & S_SIG) != 0) { 3026 mtx_unlock(&ps->ps_mtx); 3027 stopevent(p, S_SIG, sig); 3028 mtx_lock(&ps->ps_mtx); 3029 } 3030 3031 if (action == SIG_DFL) { 3032 /* 3033 * Default action, where the default is to kill 3034 * the process. (Other cases were ignored above.) 3035 */ 3036 mtx_unlock(&ps->ps_mtx); 3037 proc_td_siginfo_capture(td, &ksi.ksi_info); 3038 sigexit(td, sig); 3039 /* NOTREACHED */ 3040 } else { 3041 /* 3042 * If we get here, the signal must be caught. 3043 */ 3044 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3045 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3046 ("postsig action: blocked sig %d", sig)); 3047 3048 /* 3049 * Set the new mask value and also defer further 3050 * occurrences of this signal. 3051 * 3052 * Special case: user has done a sigsuspend. Here the 3053 * current mask is not of interest, but rather the 3054 * mask from before the sigsuspend is what we want 3055 * restored after the signal processing is completed. 3056 */ 3057 if (td->td_pflags & TDP_OLDMASK) { 3058 returnmask = td->td_oldsigmask; 3059 td->td_pflags &= ~TDP_OLDMASK; 3060 } else 3061 returnmask = td->td_sigmask; 3062 3063 if (p->p_sig == sig) { 3064 p->p_code = 0; 3065 p->p_sig = 0; 3066 } 3067 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3068 postsig_done(sig, td, ps); 3069 } 3070 return (1); 3071 } 3072 3073 /* 3074 * Kill the current process for stated reason. 3075 */ 3076 void 3077 killproc(struct proc *p, char *why) 3078 { 3079 3080 PROC_LOCK_ASSERT(p, MA_OWNED); 3081 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3082 p->p_comm); 3083 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3084 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3085 p->p_flag |= P_WKILLED; 3086 kern_psignal(p, SIGKILL); 3087 } 3088 3089 /* 3090 * Force the current process to exit with the specified signal, dumping core 3091 * if appropriate. We bypass the normal tests for masked and caught signals, 3092 * allowing unrecoverable failures to terminate the process without changing 3093 * signal state. Mark the accounting record with the signal termination. 3094 * If dumping core, save the signal number for the debugger. Calls exit and 3095 * does not return. 3096 */ 3097 void 3098 sigexit(struct thread *td, int sig) 3099 { 3100 struct proc *p = td->td_proc; 3101 3102 PROC_LOCK_ASSERT(p, MA_OWNED); 3103 p->p_acflag |= AXSIG; 3104 /* 3105 * We must be single-threading to generate a core dump. This 3106 * ensures that the registers in the core file are up-to-date. 3107 * Also, the ELF dump handler assumes that the thread list doesn't 3108 * change out from under it. 3109 * 3110 * XXX If another thread attempts to single-thread before us 3111 * (e.g. via fork()), we won't get a dump at all. 3112 */ 3113 if ((sigprop(sig) & SIGPROP_CORE) && 3114 thread_single(p, SINGLE_NO_EXIT) == 0) { 3115 p->p_sig = sig; 3116 /* 3117 * Log signals which would cause core dumps 3118 * (Log as LOG_INFO to appease those who don't want 3119 * these messages.) 3120 * XXX : Todo, as well as euid, write out ruid too 3121 * Note that coredump() drops proc lock. 3122 */ 3123 if (coredump(td) == 0) 3124 sig |= WCOREFLAG; 3125 if (kern_logsigexit) 3126 log(LOG_INFO, 3127 "pid %d (%s), uid %d: exited on signal %d%s\n", 3128 p->p_pid, p->p_comm, 3129 td->td_ucred ? td->td_ucred->cr_uid : -1, 3130 sig &~ WCOREFLAG, 3131 sig & WCOREFLAG ? " (core dumped)" : ""); 3132 } else 3133 PROC_UNLOCK(p); 3134 exit1(td, 0, sig); 3135 /* NOTREACHED */ 3136 } 3137 3138 /* 3139 * Send queued SIGCHLD to parent when child process's state 3140 * is changed. 3141 */ 3142 static void 3143 sigparent(struct proc *p, int reason, int status) 3144 { 3145 PROC_LOCK_ASSERT(p, MA_OWNED); 3146 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3147 3148 if (p->p_ksi != NULL) { 3149 p->p_ksi->ksi_signo = SIGCHLD; 3150 p->p_ksi->ksi_code = reason; 3151 p->p_ksi->ksi_status = status; 3152 p->p_ksi->ksi_pid = p->p_pid; 3153 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3154 if (KSI_ONQ(p->p_ksi)) 3155 return; 3156 } 3157 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3158 } 3159 3160 static void 3161 childproc_jobstate(struct proc *p, int reason, int sig) 3162 { 3163 struct sigacts *ps; 3164 3165 PROC_LOCK_ASSERT(p, MA_OWNED); 3166 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3167 3168 /* 3169 * Wake up parent sleeping in kern_wait(), also send 3170 * SIGCHLD to parent, but SIGCHLD does not guarantee 3171 * that parent will awake, because parent may masked 3172 * the signal. 3173 */ 3174 p->p_pptr->p_flag |= P_STATCHILD; 3175 wakeup(p->p_pptr); 3176 3177 ps = p->p_pptr->p_sigacts; 3178 mtx_lock(&ps->ps_mtx); 3179 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3180 mtx_unlock(&ps->ps_mtx); 3181 sigparent(p, reason, sig); 3182 } else 3183 mtx_unlock(&ps->ps_mtx); 3184 } 3185 3186 void 3187 childproc_stopped(struct proc *p, int reason) 3188 { 3189 3190 childproc_jobstate(p, reason, p->p_xsig); 3191 } 3192 3193 void 3194 childproc_continued(struct proc *p) 3195 { 3196 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3197 } 3198 3199 void 3200 childproc_exited(struct proc *p) 3201 { 3202 int reason, status; 3203 3204 if (WCOREDUMP(p->p_xsig)) { 3205 reason = CLD_DUMPED; 3206 status = WTERMSIG(p->p_xsig); 3207 } else if (WIFSIGNALED(p->p_xsig)) { 3208 reason = CLD_KILLED; 3209 status = WTERMSIG(p->p_xsig); 3210 } else { 3211 reason = CLD_EXITED; 3212 status = p->p_xexit; 3213 } 3214 /* 3215 * XXX avoid calling wakeup(p->p_pptr), the work is 3216 * done in exit1(). 3217 */ 3218 sigparent(p, reason, status); 3219 } 3220 3221 /* 3222 * We only have 1 character for the core count in the format 3223 * string, so the range will be 0-9 3224 */ 3225 #define MAX_NUM_CORE_FILES 10 3226 #ifndef NUM_CORE_FILES 3227 #define NUM_CORE_FILES 5 3228 #endif 3229 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3230 static int num_cores = NUM_CORE_FILES; 3231 3232 static int 3233 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3234 { 3235 int error; 3236 int new_val; 3237 3238 new_val = num_cores; 3239 error = sysctl_handle_int(oidp, &new_val, 0, req); 3240 if (error != 0 || req->newptr == NULL) 3241 return (error); 3242 if (new_val > MAX_NUM_CORE_FILES) 3243 new_val = MAX_NUM_CORE_FILES; 3244 if (new_val < 0) 3245 new_val = 0; 3246 num_cores = new_val; 3247 return (0); 3248 } 3249 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3250 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3251 3252 #define GZIP_SUFFIX ".gz" 3253 #define ZSTD_SUFFIX ".zst" 3254 3255 int compress_user_cores = 0; 3256 3257 static int 3258 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3259 { 3260 int error, val; 3261 3262 val = compress_user_cores; 3263 error = sysctl_handle_int(oidp, &val, 0, req); 3264 if (error != 0 || req->newptr == NULL) 3265 return (error); 3266 if (val != 0 && !compressor_avail(val)) 3267 return (EINVAL); 3268 compress_user_cores = val; 3269 return (error); 3270 } 3271 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3272 0, sizeof(int), sysctl_compress_user_cores, "I", 3273 "Enable compression of user corefiles (" 3274 __XSTRING(COMPRESS_GZIP) " = gzip, " 3275 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3276 3277 int compress_user_cores_level = 6; 3278 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3279 &compress_user_cores_level, 0, 3280 "Corefile compression level"); 3281 3282 /* 3283 * Protect the access to corefilename[] by allproc_lock. 3284 */ 3285 #define corefilename_lock allproc_lock 3286 3287 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3288 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3289 3290 static int 3291 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3292 { 3293 int error; 3294 3295 sx_xlock(&corefilename_lock); 3296 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3297 req); 3298 sx_xunlock(&corefilename_lock); 3299 3300 return (error); 3301 } 3302 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3303 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3304 "Process corefile name format string"); 3305 3306 /* 3307 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3308 * Expand the name described in corefilename, using name, uid, and pid 3309 * and open/create core file. 3310 * corefilename is a printf-like string, with three format specifiers: 3311 * %N name of process ("name") 3312 * %P process id (pid) 3313 * %U user id (uid) 3314 * For example, "%N.core" is the default; they can be disabled completely 3315 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3316 * This is controlled by the sysctl variable kern.corefile (see above). 3317 */ 3318 static int 3319 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3320 int compress, struct vnode **vpp, char **namep) 3321 { 3322 struct nameidata nd; 3323 struct sbuf sb; 3324 const char *format; 3325 char *hostname, *name; 3326 int indexpos, i, error, cmode, flags, oflags; 3327 3328 hostname = NULL; 3329 format = corefilename; 3330 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3331 indexpos = -1; 3332 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3333 sx_slock(&corefilename_lock); 3334 for (i = 0; format[i] != '\0'; i++) { 3335 switch (format[i]) { 3336 case '%': /* Format character */ 3337 i++; 3338 switch (format[i]) { 3339 case '%': 3340 sbuf_putc(&sb, '%'); 3341 break; 3342 case 'H': /* hostname */ 3343 if (hostname == NULL) { 3344 hostname = malloc(MAXHOSTNAMELEN, 3345 M_TEMP, M_WAITOK); 3346 } 3347 getcredhostname(td->td_ucred, hostname, 3348 MAXHOSTNAMELEN); 3349 sbuf_printf(&sb, "%s", hostname); 3350 break; 3351 case 'I': /* autoincrementing index */ 3352 sbuf_printf(&sb, "0"); 3353 indexpos = sbuf_len(&sb) - 1; 3354 break; 3355 case 'N': /* process name */ 3356 sbuf_printf(&sb, "%s", comm); 3357 break; 3358 case 'P': /* process id */ 3359 sbuf_printf(&sb, "%u", pid); 3360 break; 3361 case 'U': /* user id */ 3362 sbuf_printf(&sb, "%u", uid); 3363 break; 3364 default: 3365 log(LOG_ERR, 3366 "Unknown format character %c in " 3367 "corename `%s'\n", format[i], format); 3368 break; 3369 } 3370 break; 3371 default: 3372 sbuf_putc(&sb, format[i]); 3373 break; 3374 } 3375 } 3376 sx_sunlock(&corefilename_lock); 3377 free(hostname, M_TEMP); 3378 if (compress == COMPRESS_GZIP) 3379 sbuf_printf(&sb, GZIP_SUFFIX); 3380 else if (compress == COMPRESS_ZSTD) 3381 sbuf_printf(&sb, ZSTD_SUFFIX); 3382 if (sbuf_error(&sb) != 0) { 3383 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3384 "long\n", (long)pid, comm, (u_long)uid); 3385 sbuf_delete(&sb); 3386 free(name, M_TEMP); 3387 return (ENOMEM); 3388 } 3389 sbuf_finish(&sb); 3390 sbuf_delete(&sb); 3391 3392 cmode = S_IRUSR | S_IWUSR; 3393 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3394 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3395 3396 /* 3397 * If the core format has a %I in it, then we need to check 3398 * for existing corefiles before returning a name. 3399 * To do this we iterate over 0..num_cores to find a 3400 * non-existing core file name to use. 3401 */ 3402 if (indexpos != -1) { 3403 for (i = 0; i < num_cores; i++) { 3404 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3405 name[indexpos] = '0' + i; 3406 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3407 error = vn_open_cred(&nd, &flags, cmode, oflags, 3408 td->td_ucred, NULL); 3409 if (error) { 3410 if (error == EEXIST) 3411 continue; 3412 log(LOG_ERR, 3413 "pid %d (%s), uid (%u): Path `%s' failed " 3414 "on initial open test, error = %d\n", 3415 pid, comm, uid, name, error); 3416 } 3417 goto out; 3418 } 3419 } 3420 3421 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3422 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3423 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3424 out: 3425 if (error) { 3426 #ifdef AUDIT 3427 audit_proc_coredump(td, name, error); 3428 #endif 3429 free(name, M_TEMP); 3430 return (error); 3431 } 3432 NDFREE(&nd, NDF_ONLY_PNBUF); 3433 *vpp = nd.ni_vp; 3434 *namep = name; 3435 return (0); 3436 } 3437 3438 static int 3439 coredump_sanitise_path(const char *path) 3440 { 3441 size_t i; 3442 3443 /* 3444 * Only send a subset of ASCII to devd(8) because it 3445 * might pass these strings to sh -c. 3446 */ 3447 for (i = 0; path[i]; i++) 3448 if (!(isalpha(path[i]) || isdigit(path[i])) && 3449 path[i] != '/' && path[i] != '.' && 3450 path[i] != '-') 3451 return (0); 3452 3453 return (1); 3454 } 3455 3456 /* 3457 * Dump a process' core. The main routine does some 3458 * policy checking, and creates the name of the coredump; 3459 * then it passes on a vnode and a size limit to the process-specific 3460 * coredump routine if there is one; if there _is not_ one, it returns 3461 * ENOSYS; otherwise it returns the error from the process-specific routine. 3462 */ 3463 3464 static int 3465 coredump(struct thread *td) 3466 { 3467 struct proc *p = td->td_proc; 3468 struct ucred *cred = td->td_ucred; 3469 struct vnode *vp; 3470 struct flock lf; 3471 struct vattr vattr; 3472 int error, error1, locked; 3473 char *name; /* name of corefile */ 3474 void *rl_cookie; 3475 off_t limit; 3476 char *data = NULL; 3477 char *fullpath, *freepath = NULL; 3478 size_t len; 3479 static const char comm_name[] = "comm="; 3480 static const char core_name[] = "core="; 3481 3482 PROC_LOCK_ASSERT(p, MA_OWNED); 3483 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3484 _STOPEVENT(p, S_CORE, 0); 3485 3486 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3487 (p->p_flag2 & P2_NOTRACE) != 0) { 3488 PROC_UNLOCK(p); 3489 return (EFAULT); 3490 } 3491 3492 /* 3493 * Note that the bulk of limit checking is done after 3494 * the corefile is created. The exception is if the limit 3495 * for corefiles is 0, in which case we don't bother 3496 * creating the corefile at all. This layout means that 3497 * a corefile is truncated instead of not being created, 3498 * if it is larger than the limit. 3499 */ 3500 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3501 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3502 PROC_UNLOCK(p); 3503 return (EFBIG); 3504 } 3505 PROC_UNLOCK(p); 3506 3507 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3508 compress_user_cores, &vp, &name); 3509 if (error != 0) 3510 return (error); 3511 3512 /* 3513 * Don't dump to non-regular files or files with links. 3514 * Do not dump into system files. 3515 */ 3516 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3517 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3518 VOP_UNLOCK(vp, 0); 3519 error = EFAULT; 3520 goto out; 3521 } 3522 3523 VOP_UNLOCK(vp, 0); 3524 3525 /* Postpone other writers, including core dumps of other processes. */ 3526 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3527 3528 lf.l_whence = SEEK_SET; 3529 lf.l_start = 0; 3530 lf.l_len = 0; 3531 lf.l_type = F_WRLCK; 3532 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3533 3534 VATTR_NULL(&vattr); 3535 vattr.va_size = 0; 3536 if (set_core_nodump_flag) 3537 vattr.va_flags = UF_NODUMP; 3538 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3539 VOP_SETATTR(vp, &vattr, cred); 3540 VOP_UNLOCK(vp, 0); 3541 PROC_LOCK(p); 3542 p->p_acflag |= ACORE; 3543 PROC_UNLOCK(p); 3544 3545 if (p->p_sysent->sv_coredump != NULL) { 3546 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3547 } else { 3548 error = ENOSYS; 3549 } 3550 3551 if (locked) { 3552 lf.l_type = F_UNLCK; 3553 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3554 } 3555 vn_rangelock_unlock(vp, rl_cookie); 3556 3557 /* 3558 * Notify the userland helper that a process triggered a core dump. 3559 * This allows the helper to run an automated debugging session. 3560 */ 3561 if (error != 0 || coredump_devctl == 0) 3562 goto out; 3563 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3564 sizeof(' ') + sizeof(core_name) - 1; 3565 data = malloc(len, M_TEMP, M_WAITOK); 3566 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3567 goto out; 3568 if (!coredump_sanitise_path(fullpath)) 3569 goto out; 3570 snprintf(data, len, "%s%s ", comm_name, fullpath); 3571 free(freepath, M_TEMP); 3572 freepath = NULL; 3573 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3574 goto out; 3575 if (!coredump_sanitise_path(fullpath)) 3576 goto out; 3577 strlcat(data, core_name, len); 3578 strlcat(data, fullpath, len); 3579 devctl_notify("kernel", "signal", "coredump", data); 3580 out: 3581 error1 = vn_close(vp, FWRITE, cred, td); 3582 if (error == 0) 3583 error = error1; 3584 #ifdef AUDIT 3585 audit_proc_coredump(td, name, error); 3586 #endif 3587 free(freepath, M_TEMP); 3588 free(data, M_TEMP); 3589 free(name, M_TEMP); 3590 return (error); 3591 } 3592 3593 /* 3594 * Nonexistent system call-- signal process (may want to handle it). Flag 3595 * error in case process won't see signal immediately (blocked or ignored). 3596 */ 3597 #ifndef _SYS_SYSPROTO_H_ 3598 struct nosys_args { 3599 int dummy; 3600 }; 3601 #endif 3602 /* ARGSUSED */ 3603 int 3604 nosys(struct thread *td, struct nosys_args *args) 3605 { 3606 struct proc *p; 3607 3608 p = td->td_proc; 3609 3610 PROC_LOCK(p); 3611 tdsignal(td, SIGSYS); 3612 PROC_UNLOCK(p); 3613 if (kern_lognosys == 1 || kern_lognosys == 3) { 3614 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3615 td->td_sa.code); 3616 } 3617 if (kern_lognosys == 2 || kern_lognosys == 3) { 3618 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3619 td->td_sa.code); 3620 } 3621 return (ENOSYS); 3622 } 3623 3624 /* 3625 * Send a SIGIO or SIGURG signal to a process or process group using stored 3626 * credentials rather than those of the current process. 3627 */ 3628 void 3629 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3630 { 3631 ksiginfo_t ksi; 3632 struct sigio *sigio; 3633 3634 ksiginfo_init(&ksi); 3635 ksi.ksi_signo = sig; 3636 ksi.ksi_code = SI_KERNEL; 3637 3638 SIGIO_LOCK(); 3639 sigio = *sigiop; 3640 if (sigio == NULL) { 3641 SIGIO_UNLOCK(); 3642 return; 3643 } 3644 if (sigio->sio_pgid > 0) { 3645 PROC_LOCK(sigio->sio_proc); 3646 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3647 kern_psignal(sigio->sio_proc, sig); 3648 PROC_UNLOCK(sigio->sio_proc); 3649 } else if (sigio->sio_pgid < 0) { 3650 struct proc *p; 3651 3652 PGRP_LOCK(sigio->sio_pgrp); 3653 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3654 PROC_LOCK(p); 3655 if (p->p_state == PRS_NORMAL && 3656 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3657 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3658 kern_psignal(p, sig); 3659 PROC_UNLOCK(p); 3660 } 3661 PGRP_UNLOCK(sigio->sio_pgrp); 3662 } 3663 SIGIO_UNLOCK(); 3664 } 3665 3666 static int 3667 filt_sigattach(struct knote *kn) 3668 { 3669 struct proc *p = curproc; 3670 3671 kn->kn_ptr.p_proc = p; 3672 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3673 3674 knlist_add(p->p_klist, kn, 0); 3675 3676 return (0); 3677 } 3678 3679 static void 3680 filt_sigdetach(struct knote *kn) 3681 { 3682 struct proc *p = kn->kn_ptr.p_proc; 3683 3684 knlist_remove(p->p_klist, kn, 0); 3685 } 3686 3687 /* 3688 * signal knotes are shared with proc knotes, so we apply a mask to 3689 * the hint in order to differentiate them from process hints. This 3690 * could be avoided by using a signal-specific knote list, but probably 3691 * isn't worth the trouble. 3692 */ 3693 static int 3694 filt_signal(struct knote *kn, long hint) 3695 { 3696 3697 if (hint & NOTE_SIGNAL) { 3698 hint &= ~NOTE_SIGNAL; 3699 3700 if (kn->kn_id == hint) 3701 kn->kn_data++; 3702 } 3703 return (kn->kn_data != 0); 3704 } 3705 3706 struct sigacts * 3707 sigacts_alloc(void) 3708 { 3709 struct sigacts *ps; 3710 3711 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3712 refcount_init(&ps->ps_refcnt, 1); 3713 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3714 return (ps); 3715 } 3716 3717 void 3718 sigacts_free(struct sigacts *ps) 3719 { 3720 3721 if (refcount_release(&ps->ps_refcnt) == 0) 3722 return; 3723 mtx_destroy(&ps->ps_mtx); 3724 free(ps, M_SUBPROC); 3725 } 3726 3727 struct sigacts * 3728 sigacts_hold(struct sigacts *ps) 3729 { 3730 3731 refcount_acquire(&ps->ps_refcnt); 3732 return (ps); 3733 } 3734 3735 void 3736 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3737 { 3738 3739 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3740 mtx_lock(&src->ps_mtx); 3741 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3742 mtx_unlock(&src->ps_mtx); 3743 } 3744 3745 int 3746 sigacts_shared(struct sigacts *ps) 3747 { 3748 3749 return (ps->ps_refcnt > 1); 3750 } 3751