1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/lock.h> 61 #include <sys/malloc.h> 62 #include <sys/mutex.h> 63 #include <sys/refcount.h> 64 #include <sys/namei.h> 65 #include <sys/proc.h> 66 #include <sys/procdesc.h> 67 #include <sys/posix4.h> 68 #include <sys/pioctl.h> 69 #include <sys/racct.h> 70 #include <sys/resourcevar.h> 71 #include <sys/sdt.h> 72 #include <sys/sbuf.h> 73 #include <sys/sleepqueue.h> 74 #include <sys/smp.h> 75 #include <sys/stat.h> 76 #include <sys/sx.h> 77 #include <sys/syscallsubr.h> 78 #include <sys/sysctl.h> 79 #include <sys/sysent.h> 80 #include <sys/syslog.h> 81 #include <sys/sysproto.h> 82 #include <sys/timers.h> 83 #include <sys/unistd.h> 84 #include <sys/wait.h> 85 #include <vm/vm.h> 86 #include <vm/vm_extern.h> 87 #include <vm/uma.h> 88 89 #include <sys/jail.h> 90 91 #include <machine/cpu.h> 92 93 #include <security/audit/audit.h> 94 95 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 96 97 SDT_PROVIDER_DECLARE(proc); 98 SDT_PROBE_DEFINE3(proc, , , signal__send, 99 "struct thread *", "struct proc *", "int"); 100 SDT_PROBE_DEFINE2(proc, , , signal__clear, 101 "int", "ksiginfo_t *"); 102 SDT_PROBE_DEFINE3(proc, , , signal__discard, 103 "struct thread *", "struct proc *", "int"); 104 105 static int coredump(struct thread *); 106 static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108 static int issignal(struct thread *td); 109 static int sigprop(int sig); 110 static void tdsigwakeup(struct thread *, int, sig_t, int); 111 static int sig_suspend_threads(struct thread *, struct proc *, int); 112 static int filt_sigattach(struct knote *kn); 113 static void filt_sigdetach(struct knote *kn); 114 static int filt_signal(struct knote *kn, long hint); 115 static struct thread *sigtd(struct proc *p, int sig, int prop); 116 static void sigqueue_start(void); 117 118 static uma_zone_t ksiginfo_zone = NULL; 119 struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124 }; 125 126 static int kern_logsigexit = 1; 127 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131 static int kern_forcesigexit = 1; 132 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 136 "POSIX real time signal"); 137 138 static int max_pending_per_proc = 128; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 140 &max_pending_per_proc, 0, "Max pending signals per proc"); 141 142 static int preallocate_siginfo = 1024; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146 static int signal_overflow = 0; 147 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150 static int signal_alloc_fail = 0; 151 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154 static int kern_lognosys = 0; 155 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 156 "Log invalid syscalls"); 157 158 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160 /* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165 #define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172 static int sugid_coredump; 173 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176 static int capmode_coredump; 177 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180 static int do_coredump = 1; 181 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184 static int set_core_nodump_flag = 0; 185 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188 static int coredump_devctl = 0; 189 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192 /* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197 #define SIGPROP_KILL 0x01 /* terminates process by default */ 198 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 199 #define SIGPROP_STOP 0x04 /* suspend process */ 200 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 201 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 202 #define SIGPROP_CONT 0x20 /* continue if suspended */ 203 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 204 205 static int sigproptbl[NSIG] = { 206 [SIGHUP] = SIGPROP_KILL, 207 [SIGINT] = SIGPROP_KILL, 208 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 209 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 210 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGKILL] = SIGPROP_KILL, 215 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGPIPE] = SIGPROP_KILL, 219 [SIGALRM] = SIGPROP_KILL, 220 [SIGTERM] = SIGPROP_KILL, 221 [SIGURG] = SIGPROP_IGNORE, 222 [SIGSTOP] = SIGPROP_STOP, 223 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 224 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 225 [SIGCHLD] = SIGPROP_IGNORE, 226 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 227 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 228 [SIGIO] = SIGPROP_IGNORE, 229 [SIGXCPU] = SIGPROP_KILL, 230 [SIGXFSZ] = SIGPROP_KILL, 231 [SIGVTALRM] = SIGPROP_KILL, 232 [SIGPROF] = SIGPROP_KILL, 233 [SIGWINCH] = SIGPROP_IGNORE, 234 [SIGINFO] = SIGPROP_IGNORE, 235 [SIGUSR1] = SIGPROP_KILL, 236 [SIGUSR2] = SIGPROP_KILL, 237 }; 238 239 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241 static void 242 sigqueue_start(void) 243 { 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250 } 251 252 ksiginfo_t * 253 ksiginfo_alloc(int wait) 254 { 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263 } 264 265 void 266 ksiginfo_free(ksiginfo_t *ksi) 267 { 268 uma_zfree(ksiginfo_zone, ksi); 269 } 270 271 static __inline int 272 ksiginfo_tryfree(ksiginfo_t *ksi) 273 { 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279 } 280 281 void 282 sigqueue_init(sigqueue_t *list, struct proc *p) 283 { 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290 } 291 292 /* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298 static int 299 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300 { 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339 } 340 341 void 342 sigqueue_take(ksiginfo_t *ksi) 343 { 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365 } 366 367 static int 368 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369 { 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432 out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435 } 436 437 void 438 sigqueue_flush(sigqueue_t *sq) 439 { 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458 } 459 460 static void 461 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462 { 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499 } 500 501 #if 0 502 static void 503 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510 } 511 #endif 512 513 static void 514 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515 { 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533 } 534 535 void 536 sigqueue_delete(sigqueue_t *sq, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543 } 544 545 /* Remove a set of signals for a process */ 546 static void 547 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548 { 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561 } 562 563 void 564 sigqueue_delete_proc(struct proc *p, int signo) 565 { 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571 } 572 573 static void 574 sigqueue_delete_stopmask_proc(struct proc *p) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584 } 585 586 /* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591 int 592 cursig(struct thread *td) 593 { 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598 } 599 600 /* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605 void 606 signotify(struct thread *td) 607 { 608 609 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 610 611 if (SIGPENDING(td)) { 612 thread_lock(td); 613 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 614 thread_unlock(td); 615 } 616 } 617 618 int 619 sigonstack(size_t sp) 620 { 621 struct thread *td = curthread; 622 623 return ((td->td_pflags & TDP_ALTSTACK) ? 624 #if defined(COMPAT_43) 625 ((td->td_sigstk.ss_size == 0) ? 626 (td->td_sigstk.ss_flags & SS_ONSTACK) : 627 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 628 #else 629 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 630 #endif 631 : 0); 632 } 633 634 static __inline int 635 sigprop(int sig) 636 { 637 638 if (sig > 0 && sig < nitems(sigproptbl)) 639 return (sigproptbl[sig]); 640 return (0); 641 } 642 643 int 644 sig_ffs(sigset_t *set) 645 { 646 int i; 647 648 for (i = 0; i < _SIG_WORDS; i++) 649 if (set->__bits[i]) 650 return (ffs(set->__bits[i]) + (i * 32)); 651 return (0); 652 } 653 654 static bool 655 sigact_flag_test(const struct sigaction *act, int flag) 656 { 657 658 /* 659 * SA_SIGINFO is reset when signal disposition is set to 660 * ignore or default. Other flags are kept according to user 661 * settings. 662 */ 663 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 664 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 665 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 666 } 667 668 /* 669 * kern_sigaction 670 * sigaction 671 * freebsd4_sigaction 672 * osigaction 673 */ 674 int 675 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 676 struct sigaction *oact, int flags) 677 { 678 struct sigacts *ps; 679 struct proc *p = td->td_proc; 680 681 if (!_SIG_VALID(sig)) 682 return (EINVAL); 683 if (act != NULL && act->sa_handler != SIG_DFL && 684 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 685 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 686 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 687 return (EINVAL); 688 689 PROC_LOCK(p); 690 ps = p->p_sigacts; 691 mtx_lock(&ps->ps_mtx); 692 if (oact) { 693 memset(oact, 0, sizeof(*oact)); 694 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 695 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 696 oact->sa_flags |= SA_ONSTACK; 697 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 698 oact->sa_flags |= SA_RESTART; 699 if (SIGISMEMBER(ps->ps_sigreset, sig)) 700 oact->sa_flags |= SA_RESETHAND; 701 if (SIGISMEMBER(ps->ps_signodefer, sig)) 702 oact->sa_flags |= SA_NODEFER; 703 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 704 oact->sa_flags |= SA_SIGINFO; 705 oact->sa_sigaction = 706 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 707 } else 708 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 709 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 710 oact->sa_flags |= SA_NOCLDSTOP; 711 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 712 oact->sa_flags |= SA_NOCLDWAIT; 713 } 714 if (act) { 715 if ((sig == SIGKILL || sig == SIGSTOP) && 716 act->sa_handler != SIG_DFL) { 717 mtx_unlock(&ps->ps_mtx); 718 PROC_UNLOCK(p); 719 return (EINVAL); 720 } 721 722 /* 723 * Change setting atomically. 724 */ 725 726 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 727 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 728 if (sigact_flag_test(act, SA_SIGINFO)) { 729 ps->ps_sigact[_SIG_IDX(sig)] = 730 (__sighandler_t *)act->sa_sigaction; 731 SIGADDSET(ps->ps_siginfo, sig); 732 } else { 733 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 734 SIGDELSET(ps->ps_siginfo, sig); 735 } 736 if (!sigact_flag_test(act, SA_RESTART)) 737 SIGADDSET(ps->ps_sigintr, sig); 738 else 739 SIGDELSET(ps->ps_sigintr, sig); 740 if (sigact_flag_test(act, SA_ONSTACK)) 741 SIGADDSET(ps->ps_sigonstack, sig); 742 else 743 SIGDELSET(ps->ps_sigonstack, sig); 744 if (sigact_flag_test(act, SA_RESETHAND)) 745 SIGADDSET(ps->ps_sigreset, sig); 746 else 747 SIGDELSET(ps->ps_sigreset, sig); 748 if (sigact_flag_test(act, SA_NODEFER)) 749 SIGADDSET(ps->ps_signodefer, sig); 750 else 751 SIGDELSET(ps->ps_signodefer, sig); 752 if (sig == SIGCHLD) { 753 if (act->sa_flags & SA_NOCLDSTOP) 754 ps->ps_flag |= PS_NOCLDSTOP; 755 else 756 ps->ps_flag &= ~PS_NOCLDSTOP; 757 if (act->sa_flags & SA_NOCLDWAIT) { 758 /* 759 * Paranoia: since SA_NOCLDWAIT is implemented 760 * by reparenting the dying child to PID 1 (and 761 * trust it to reap the zombie), PID 1 itself 762 * is forbidden to set SA_NOCLDWAIT. 763 */ 764 if (p->p_pid == 1) 765 ps->ps_flag &= ~PS_NOCLDWAIT; 766 else 767 ps->ps_flag |= PS_NOCLDWAIT; 768 } else 769 ps->ps_flag &= ~PS_NOCLDWAIT; 770 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 771 ps->ps_flag |= PS_CLDSIGIGN; 772 else 773 ps->ps_flag &= ~PS_CLDSIGIGN; 774 } 775 /* 776 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 777 * and for signals set to SIG_DFL where the default is to 778 * ignore. However, don't put SIGCONT in ps_sigignore, as we 779 * have to restart the process. 780 */ 781 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 782 (sigprop(sig) & SIGPROP_IGNORE && 783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 784 /* never to be seen again */ 785 sigqueue_delete_proc(p, sig); 786 if (sig != SIGCONT) 787 /* easier in psignal */ 788 SIGADDSET(ps->ps_sigignore, sig); 789 SIGDELSET(ps->ps_sigcatch, sig); 790 } else { 791 SIGDELSET(ps->ps_sigignore, sig); 792 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 793 SIGDELSET(ps->ps_sigcatch, sig); 794 else 795 SIGADDSET(ps->ps_sigcatch, sig); 796 } 797 #ifdef COMPAT_FREEBSD4 798 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 799 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 800 (flags & KSA_FREEBSD4) == 0) 801 SIGDELSET(ps->ps_freebsd4, sig); 802 else 803 SIGADDSET(ps->ps_freebsd4, sig); 804 #endif 805 #ifdef COMPAT_43 806 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 807 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 808 (flags & KSA_OSIGSET) == 0) 809 SIGDELSET(ps->ps_osigset, sig); 810 else 811 SIGADDSET(ps->ps_osigset, sig); 812 #endif 813 } 814 mtx_unlock(&ps->ps_mtx); 815 PROC_UNLOCK(p); 816 return (0); 817 } 818 819 #ifndef _SYS_SYSPROTO_H_ 820 struct sigaction_args { 821 int sig; 822 struct sigaction *act; 823 struct sigaction *oact; 824 }; 825 #endif 826 int 827 sys_sigaction(struct thread *td, struct sigaction_args *uap) 828 { 829 struct sigaction act, oact; 830 struct sigaction *actp, *oactp; 831 int error; 832 833 actp = (uap->act != NULL) ? &act : NULL; 834 oactp = (uap->oact != NULL) ? &oact : NULL; 835 if (actp) { 836 error = copyin(uap->act, actp, sizeof(act)); 837 if (error) 838 return (error); 839 } 840 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 841 if (oactp && !error) 842 error = copyout(oactp, uap->oact, sizeof(oact)); 843 return (error); 844 } 845 846 #ifdef COMPAT_FREEBSD4 847 #ifndef _SYS_SYSPROTO_H_ 848 struct freebsd4_sigaction_args { 849 int sig; 850 struct sigaction *act; 851 struct sigaction *oact; 852 }; 853 #endif 854 int 855 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 856 { 857 struct sigaction act, oact; 858 struct sigaction *actp, *oactp; 859 int error; 860 861 862 actp = (uap->act != NULL) ? &act : NULL; 863 oactp = (uap->oact != NULL) ? &oact : NULL; 864 if (actp) { 865 error = copyin(uap->act, actp, sizeof(act)); 866 if (error) 867 return (error); 868 } 869 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 870 if (oactp && !error) 871 error = copyout(oactp, uap->oact, sizeof(oact)); 872 return (error); 873 } 874 #endif /* COMAPT_FREEBSD4 */ 875 876 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 877 #ifndef _SYS_SYSPROTO_H_ 878 struct osigaction_args { 879 int signum; 880 struct osigaction *nsa; 881 struct osigaction *osa; 882 }; 883 #endif 884 int 885 osigaction(struct thread *td, struct osigaction_args *uap) 886 { 887 struct osigaction sa; 888 struct sigaction nsa, osa; 889 struct sigaction *nsap, *osap; 890 int error; 891 892 if (uap->signum <= 0 || uap->signum >= ONSIG) 893 return (EINVAL); 894 895 nsap = (uap->nsa != NULL) ? &nsa : NULL; 896 osap = (uap->osa != NULL) ? &osa : NULL; 897 898 if (nsap) { 899 error = copyin(uap->nsa, &sa, sizeof(sa)); 900 if (error) 901 return (error); 902 nsap->sa_handler = sa.sa_handler; 903 nsap->sa_flags = sa.sa_flags; 904 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 905 } 906 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 907 if (osap && !error) { 908 sa.sa_handler = osap->sa_handler; 909 sa.sa_flags = osap->sa_flags; 910 SIG2OSIG(osap->sa_mask, sa.sa_mask); 911 error = copyout(&sa, uap->osa, sizeof(sa)); 912 } 913 return (error); 914 } 915 916 #if !defined(__i386__) 917 /* Avoid replicating the same stub everywhere */ 918 int 919 osigreturn(struct thread *td, struct osigreturn_args *uap) 920 { 921 922 return (nosys(td, (struct nosys_args *)uap)); 923 } 924 #endif 925 #endif /* COMPAT_43 */ 926 927 /* 928 * Initialize signal state for process 0; 929 * set to ignore signals that are ignored by default. 930 */ 931 void 932 siginit(struct proc *p) 933 { 934 int i; 935 struct sigacts *ps; 936 937 PROC_LOCK(p); 938 ps = p->p_sigacts; 939 mtx_lock(&ps->ps_mtx); 940 for (i = 1; i <= NSIG; i++) { 941 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 942 SIGADDSET(ps->ps_sigignore, i); 943 } 944 } 945 mtx_unlock(&ps->ps_mtx); 946 PROC_UNLOCK(p); 947 } 948 949 /* 950 * Reset specified signal to the default disposition. 951 */ 952 static void 953 sigdflt(struct sigacts *ps, int sig) 954 { 955 956 mtx_assert(&ps->ps_mtx, MA_OWNED); 957 SIGDELSET(ps->ps_sigcatch, sig); 958 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 959 SIGADDSET(ps->ps_sigignore, sig); 960 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 961 SIGDELSET(ps->ps_siginfo, sig); 962 } 963 964 /* 965 * Reset signals for an exec of the specified process. 966 */ 967 void 968 execsigs(struct proc *p) 969 { 970 sigset_t osigignore; 971 struct sigacts *ps; 972 int sig; 973 struct thread *td; 974 975 /* 976 * Reset caught signals. Held signals remain held 977 * through td_sigmask (unless they were caught, 978 * and are now ignored by default). 979 */ 980 PROC_LOCK_ASSERT(p, MA_OWNED); 981 ps = p->p_sigacts; 982 mtx_lock(&ps->ps_mtx); 983 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 984 sig = sig_ffs(&ps->ps_sigcatch); 985 sigdflt(ps, sig); 986 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 987 sigqueue_delete_proc(p, sig); 988 } 989 990 /* 991 * As CloudABI processes cannot modify signal handlers, fully 992 * reset all signals to their default behavior. Do ignore 993 * SIGPIPE, as it would otherwise be impossible to recover from 994 * writes to broken pipes and sockets. 995 */ 996 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 997 osigignore = ps->ps_sigignore; 998 while (SIGNOTEMPTY(osigignore)) { 999 sig = sig_ffs(&osigignore); 1000 SIGDELSET(osigignore, sig); 1001 if (sig != SIGPIPE) 1002 sigdflt(ps, sig); 1003 } 1004 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1005 } 1006 1007 /* 1008 * Reset stack state to the user stack. 1009 * Clear set of signals caught on the signal stack. 1010 */ 1011 td = curthread; 1012 MPASS(td->td_proc == p); 1013 td->td_sigstk.ss_flags = SS_DISABLE; 1014 td->td_sigstk.ss_size = 0; 1015 td->td_sigstk.ss_sp = 0; 1016 td->td_pflags &= ~TDP_ALTSTACK; 1017 /* 1018 * Reset no zombies if child dies flag as Solaris does. 1019 */ 1020 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1021 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1022 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1023 mtx_unlock(&ps->ps_mtx); 1024 } 1025 1026 /* 1027 * kern_sigprocmask() 1028 * 1029 * Manipulate signal mask. 1030 */ 1031 int 1032 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1033 int flags) 1034 { 1035 sigset_t new_block, oset1; 1036 struct proc *p; 1037 int error; 1038 1039 p = td->td_proc; 1040 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1041 PROC_LOCK_ASSERT(p, MA_OWNED); 1042 else 1043 PROC_LOCK(p); 1044 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1045 ? MA_OWNED : MA_NOTOWNED); 1046 if (oset != NULL) 1047 *oset = td->td_sigmask; 1048 1049 error = 0; 1050 if (set != NULL) { 1051 switch (how) { 1052 case SIG_BLOCK: 1053 SIG_CANTMASK(*set); 1054 oset1 = td->td_sigmask; 1055 SIGSETOR(td->td_sigmask, *set); 1056 new_block = td->td_sigmask; 1057 SIGSETNAND(new_block, oset1); 1058 break; 1059 case SIG_UNBLOCK: 1060 SIGSETNAND(td->td_sigmask, *set); 1061 signotify(td); 1062 goto out; 1063 case SIG_SETMASK: 1064 SIG_CANTMASK(*set); 1065 oset1 = td->td_sigmask; 1066 if (flags & SIGPROCMASK_OLD) 1067 SIGSETLO(td->td_sigmask, *set); 1068 else 1069 td->td_sigmask = *set; 1070 new_block = td->td_sigmask; 1071 SIGSETNAND(new_block, oset1); 1072 signotify(td); 1073 break; 1074 default: 1075 error = EINVAL; 1076 goto out; 1077 } 1078 1079 /* 1080 * The new_block set contains signals that were not previously 1081 * blocked, but are blocked now. 1082 * 1083 * In case we block any signal that was not previously blocked 1084 * for td, and process has the signal pending, try to schedule 1085 * signal delivery to some thread that does not block the 1086 * signal, possibly waking it up. 1087 */ 1088 if (p->p_numthreads != 1) 1089 reschedule_signals(p, new_block, flags); 1090 } 1091 1092 out: 1093 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1094 PROC_UNLOCK(p); 1095 return (error); 1096 } 1097 1098 #ifndef _SYS_SYSPROTO_H_ 1099 struct sigprocmask_args { 1100 int how; 1101 const sigset_t *set; 1102 sigset_t *oset; 1103 }; 1104 #endif 1105 int 1106 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1107 { 1108 sigset_t set, oset; 1109 sigset_t *setp, *osetp; 1110 int error; 1111 1112 setp = (uap->set != NULL) ? &set : NULL; 1113 osetp = (uap->oset != NULL) ? &oset : NULL; 1114 if (setp) { 1115 error = copyin(uap->set, setp, sizeof(set)); 1116 if (error) 1117 return (error); 1118 } 1119 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1120 if (osetp && !error) { 1121 error = copyout(osetp, uap->oset, sizeof(oset)); 1122 } 1123 return (error); 1124 } 1125 1126 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1127 #ifndef _SYS_SYSPROTO_H_ 1128 struct osigprocmask_args { 1129 int how; 1130 osigset_t mask; 1131 }; 1132 #endif 1133 int 1134 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1135 { 1136 sigset_t set, oset; 1137 int error; 1138 1139 OSIG2SIG(uap->mask, set); 1140 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1141 SIG2OSIG(oset, td->td_retval[0]); 1142 return (error); 1143 } 1144 #endif /* COMPAT_43 */ 1145 1146 int 1147 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1148 { 1149 ksiginfo_t ksi; 1150 sigset_t set; 1151 int error; 1152 1153 error = copyin(uap->set, &set, sizeof(set)); 1154 if (error) { 1155 td->td_retval[0] = error; 1156 return (0); 1157 } 1158 1159 error = kern_sigtimedwait(td, set, &ksi, NULL); 1160 if (error) { 1161 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1162 error = ERESTART; 1163 if (error == ERESTART) 1164 return (error); 1165 td->td_retval[0] = error; 1166 return (0); 1167 } 1168 1169 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1170 td->td_retval[0] = error; 1171 return (0); 1172 } 1173 1174 int 1175 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1176 { 1177 struct timespec ts; 1178 struct timespec *timeout; 1179 sigset_t set; 1180 ksiginfo_t ksi; 1181 int error; 1182 1183 if (uap->timeout) { 1184 error = copyin(uap->timeout, &ts, sizeof(ts)); 1185 if (error) 1186 return (error); 1187 1188 timeout = &ts; 1189 } else 1190 timeout = NULL; 1191 1192 error = copyin(uap->set, &set, sizeof(set)); 1193 if (error) 1194 return (error); 1195 1196 error = kern_sigtimedwait(td, set, &ksi, timeout); 1197 if (error) 1198 return (error); 1199 1200 if (uap->info) 1201 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1202 1203 if (error == 0) 1204 td->td_retval[0] = ksi.ksi_signo; 1205 return (error); 1206 } 1207 1208 int 1209 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1210 { 1211 ksiginfo_t ksi; 1212 sigset_t set; 1213 int error; 1214 1215 error = copyin(uap->set, &set, sizeof(set)); 1216 if (error) 1217 return (error); 1218 1219 error = kern_sigtimedwait(td, set, &ksi, NULL); 1220 if (error) 1221 return (error); 1222 1223 if (uap->info) 1224 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1225 1226 if (error == 0) 1227 td->td_retval[0] = ksi.ksi_signo; 1228 return (error); 1229 } 1230 1231 static void 1232 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1233 { 1234 struct thread *thr; 1235 1236 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1237 if (thr == td) 1238 thr->td_si = *si; 1239 else 1240 thr->td_si.si_signo = 0; 1241 } 1242 } 1243 1244 int 1245 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1246 struct timespec *timeout) 1247 { 1248 struct sigacts *ps; 1249 sigset_t saved_mask, new_block; 1250 struct proc *p; 1251 int error, sig, timo, timevalid = 0; 1252 struct timespec rts, ets, ts; 1253 struct timeval tv; 1254 1255 p = td->td_proc; 1256 error = 0; 1257 ets.tv_sec = 0; 1258 ets.tv_nsec = 0; 1259 1260 if (timeout != NULL) { 1261 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1262 timevalid = 1; 1263 getnanouptime(&rts); 1264 ets = rts; 1265 timespecadd(&ets, timeout); 1266 } 1267 } 1268 ksiginfo_init(ksi); 1269 /* Some signals can not be waited for. */ 1270 SIG_CANTMASK(waitset); 1271 ps = p->p_sigacts; 1272 PROC_LOCK(p); 1273 saved_mask = td->td_sigmask; 1274 SIGSETNAND(td->td_sigmask, waitset); 1275 for (;;) { 1276 mtx_lock(&ps->ps_mtx); 1277 sig = cursig(td); 1278 mtx_unlock(&ps->ps_mtx); 1279 KASSERT(sig >= 0, ("sig %d", sig)); 1280 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1281 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1282 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1283 error = 0; 1284 break; 1285 } 1286 } 1287 1288 if (error != 0) 1289 break; 1290 1291 /* 1292 * POSIX says this must be checked after looking for pending 1293 * signals. 1294 */ 1295 if (timeout != NULL) { 1296 if (!timevalid) { 1297 error = EINVAL; 1298 break; 1299 } 1300 getnanouptime(&rts); 1301 if (timespeccmp(&rts, &ets, >=)) { 1302 error = EAGAIN; 1303 break; 1304 } 1305 ts = ets; 1306 timespecsub(&ts, &rts); 1307 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1308 timo = tvtohz(&tv); 1309 } else { 1310 timo = 0; 1311 } 1312 1313 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1314 1315 if (timeout != NULL) { 1316 if (error == ERESTART) { 1317 /* Timeout can not be restarted. */ 1318 error = EINTR; 1319 } else if (error == EAGAIN) { 1320 /* We will calculate timeout by ourself. */ 1321 error = 0; 1322 } 1323 } 1324 } 1325 1326 new_block = saved_mask; 1327 SIGSETNAND(new_block, td->td_sigmask); 1328 td->td_sigmask = saved_mask; 1329 /* 1330 * Fewer signals can be delivered to us, reschedule signal 1331 * notification. 1332 */ 1333 if (p->p_numthreads != 1) 1334 reschedule_signals(p, new_block, 0); 1335 1336 if (error == 0) { 1337 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1338 1339 if (ksi->ksi_code == SI_TIMER) 1340 itimer_accept(p, ksi->ksi_timerid, ksi); 1341 1342 #ifdef KTRACE 1343 if (KTRPOINT(td, KTR_PSIG)) { 1344 sig_t action; 1345 1346 mtx_lock(&ps->ps_mtx); 1347 action = ps->ps_sigact[_SIG_IDX(sig)]; 1348 mtx_unlock(&ps->ps_mtx); 1349 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1350 } 1351 #endif 1352 if (sig == SIGKILL) { 1353 proc_td_siginfo_capture(td, &ksi->ksi_info); 1354 sigexit(td, sig); 1355 } 1356 } 1357 PROC_UNLOCK(p); 1358 return (error); 1359 } 1360 1361 #ifndef _SYS_SYSPROTO_H_ 1362 struct sigpending_args { 1363 sigset_t *set; 1364 }; 1365 #endif 1366 int 1367 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1368 { 1369 struct proc *p = td->td_proc; 1370 sigset_t pending; 1371 1372 PROC_LOCK(p); 1373 pending = p->p_sigqueue.sq_signals; 1374 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1375 PROC_UNLOCK(p); 1376 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1377 } 1378 1379 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1380 #ifndef _SYS_SYSPROTO_H_ 1381 struct osigpending_args { 1382 int dummy; 1383 }; 1384 #endif 1385 int 1386 osigpending(struct thread *td, struct osigpending_args *uap) 1387 { 1388 struct proc *p = td->td_proc; 1389 sigset_t pending; 1390 1391 PROC_LOCK(p); 1392 pending = p->p_sigqueue.sq_signals; 1393 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1394 PROC_UNLOCK(p); 1395 SIG2OSIG(pending, td->td_retval[0]); 1396 return (0); 1397 } 1398 #endif /* COMPAT_43 */ 1399 1400 #if defined(COMPAT_43) 1401 /* 1402 * Generalized interface signal handler, 4.3-compatible. 1403 */ 1404 #ifndef _SYS_SYSPROTO_H_ 1405 struct osigvec_args { 1406 int signum; 1407 struct sigvec *nsv; 1408 struct sigvec *osv; 1409 }; 1410 #endif 1411 /* ARGSUSED */ 1412 int 1413 osigvec(struct thread *td, struct osigvec_args *uap) 1414 { 1415 struct sigvec vec; 1416 struct sigaction nsa, osa; 1417 struct sigaction *nsap, *osap; 1418 int error; 1419 1420 if (uap->signum <= 0 || uap->signum >= ONSIG) 1421 return (EINVAL); 1422 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1423 osap = (uap->osv != NULL) ? &osa : NULL; 1424 if (nsap) { 1425 error = copyin(uap->nsv, &vec, sizeof(vec)); 1426 if (error) 1427 return (error); 1428 nsap->sa_handler = vec.sv_handler; 1429 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1430 nsap->sa_flags = vec.sv_flags; 1431 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1432 } 1433 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1434 if (osap && !error) { 1435 vec.sv_handler = osap->sa_handler; 1436 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1437 vec.sv_flags = osap->sa_flags; 1438 vec.sv_flags &= ~SA_NOCLDWAIT; 1439 vec.sv_flags ^= SA_RESTART; 1440 error = copyout(&vec, uap->osv, sizeof(vec)); 1441 } 1442 return (error); 1443 } 1444 1445 #ifndef _SYS_SYSPROTO_H_ 1446 struct osigblock_args { 1447 int mask; 1448 }; 1449 #endif 1450 int 1451 osigblock(struct thread *td, struct osigblock_args *uap) 1452 { 1453 sigset_t set, oset; 1454 1455 OSIG2SIG(uap->mask, set); 1456 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1457 SIG2OSIG(oset, td->td_retval[0]); 1458 return (0); 1459 } 1460 1461 #ifndef _SYS_SYSPROTO_H_ 1462 struct osigsetmask_args { 1463 int mask; 1464 }; 1465 #endif 1466 int 1467 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1468 { 1469 sigset_t set, oset; 1470 1471 OSIG2SIG(uap->mask, set); 1472 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1473 SIG2OSIG(oset, td->td_retval[0]); 1474 return (0); 1475 } 1476 #endif /* COMPAT_43 */ 1477 1478 /* 1479 * Suspend calling thread until signal, providing mask to be set in the 1480 * meantime. 1481 */ 1482 #ifndef _SYS_SYSPROTO_H_ 1483 struct sigsuspend_args { 1484 const sigset_t *sigmask; 1485 }; 1486 #endif 1487 /* ARGSUSED */ 1488 int 1489 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1490 { 1491 sigset_t mask; 1492 int error; 1493 1494 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1495 if (error) 1496 return (error); 1497 return (kern_sigsuspend(td, mask)); 1498 } 1499 1500 int 1501 kern_sigsuspend(struct thread *td, sigset_t mask) 1502 { 1503 struct proc *p = td->td_proc; 1504 int has_sig, sig; 1505 1506 /* 1507 * When returning from sigsuspend, we want 1508 * the old mask to be restored after the 1509 * signal handler has finished. Thus, we 1510 * save it here and mark the sigacts structure 1511 * to indicate this. 1512 */ 1513 PROC_LOCK(p); 1514 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1515 SIGPROCMASK_PROC_LOCKED); 1516 td->td_pflags |= TDP_OLDMASK; 1517 1518 /* 1519 * Process signals now. Otherwise, we can get spurious wakeup 1520 * due to signal entered process queue, but delivered to other 1521 * thread. But sigsuspend should return only on signal 1522 * delivery. 1523 */ 1524 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1525 for (has_sig = 0; !has_sig;) { 1526 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1527 0) == 0) 1528 /* void */; 1529 thread_suspend_check(0); 1530 mtx_lock(&p->p_sigacts->ps_mtx); 1531 while ((sig = cursig(td)) != 0) { 1532 KASSERT(sig >= 0, ("sig %d", sig)); 1533 has_sig += postsig(sig); 1534 } 1535 mtx_unlock(&p->p_sigacts->ps_mtx); 1536 } 1537 PROC_UNLOCK(p); 1538 td->td_errno = EINTR; 1539 td->td_pflags |= TDP_NERRNO; 1540 return (EJUSTRETURN); 1541 } 1542 1543 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1544 /* 1545 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1546 * convention: libc stub passes mask, not pointer, to save a copyin. 1547 */ 1548 #ifndef _SYS_SYSPROTO_H_ 1549 struct osigsuspend_args { 1550 osigset_t mask; 1551 }; 1552 #endif 1553 /* ARGSUSED */ 1554 int 1555 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1556 { 1557 sigset_t mask; 1558 1559 OSIG2SIG(uap->mask, mask); 1560 return (kern_sigsuspend(td, mask)); 1561 } 1562 #endif /* COMPAT_43 */ 1563 1564 #if defined(COMPAT_43) 1565 #ifndef _SYS_SYSPROTO_H_ 1566 struct osigstack_args { 1567 struct sigstack *nss; 1568 struct sigstack *oss; 1569 }; 1570 #endif 1571 /* ARGSUSED */ 1572 int 1573 osigstack(struct thread *td, struct osigstack_args *uap) 1574 { 1575 struct sigstack nss, oss; 1576 int error = 0; 1577 1578 if (uap->nss != NULL) { 1579 error = copyin(uap->nss, &nss, sizeof(nss)); 1580 if (error) 1581 return (error); 1582 } 1583 oss.ss_sp = td->td_sigstk.ss_sp; 1584 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1585 if (uap->nss != NULL) { 1586 td->td_sigstk.ss_sp = nss.ss_sp; 1587 td->td_sigstk.ss_size = 0; 1588 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1589 td->td_pflags |= TDP_ALTSTACK; 1590 } 1591 if (uap->oss != NULL) 1592 error = copyout(&oss, uap->oss, sizeof(oss)); 1593 1594 return (error); 1595 } 1596 #endif /* COMPAT_43 */ 1597 1598 #ifndef _SYS_SYSPROTO_H_ 1599 struct sigaltstack_args { 1600 stack_t *ss; 1601 stack_t *oss; 1602 }; 1603 #endif 1604 /* ARGSUSED */ 1605 int 1606 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1607 { 1608 stack_t ss, oss; 1609 int error; 1610 1611 if (uap->ss != NULL) { 1612 error = copyin(uap->ss, &ss, sizeof(ss)); 1613 if (error) 1614 return (error); 1615 } 1616 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1617 (uap->oss != NULL) ? &oss : NULL); 1618 if (error) 1619 return (error); 1620 if (uap->oss != NULL) 1621 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1622 return (error); 1623 } 1624 1625 int 1626 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1627 { 1628 struct proc *p = td->td_proc; 1629 int oonstack; 1630 1631 oonstack = sigonstack(cpu_getstack(td)); 1632 1633 if (oss != NULL) { 1634 *oss = td->td_sigstk; 1635 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1636 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1637 } 1638 1639 if (ss != NULL) { 1640 if (oonstack) 1641 return (EPERM); 1642 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1643 return (EINVAL); 1644 if (!(ss->ss_flags & SS_DISABLE)) { 1645 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1646 return (ENOMEM); 1647 1648 td->td_sigstk = *ss; 1649 td->td_pflags |= TDP_ALTSTACK; 1650 } else { 1651 td->td_pflags &= ~TDP_ALTSTACK; 1652 } 1653 } 1654 return (0); 1655 } 1656 1657 /* 1658 * Common code for kill process group/broadcast kill. 1659 * cp is calling process. 1660 */ 1661 static int 1662 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1663 { 1664 struct proc *p; 1665 struct pgrp *pgrp; 1666 int err; 1667 int ret; 1668 1669 ret = ESRCH; 1670 if (all) { 1671 /* 1672 * broadcast 1673 */ 1674 sx_slock(&allproc_lock); 1675 FOREACH_PROC_IN_SYSTEM(p) { 1676 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1677 p == td->td_proc || p->p_state == PRS_NEW) { 1678 continue; 1679 } 1680 PROC_LOCK(p); 1681 err = p_cansignal(td, p, sig); 1682 if (err == 0) { 1683 if (sig) 1684 pksignal(p, sig, ksi); 1685 ret = err; 1686 } 1687 else if (ret == ESRCH) 1688 ret = err; 1689 PROC_UNLOCK(p); 1690 } 1691 sx_sunlock(&allproc_lock); 1692 } else { 1693 sx_slock(&proctree_lock); 1694 if (pgid == 0) { 1695 /* 1696 * zero pgid means send to my process group. 1697 */ 1698 pgrp = td->td_proc->p_pgrp; 1699 PGRP_LOCK(pgrp); 1700 } else { 1701 pgrp = pgfind(pgid); 1702 if (pgrp == NULL) { 1703 sx_sunlock(&proctree_lock); 1704 return (ESRCH); 1705 } 1706 } 1707 sx_sunlock(&proctree_lock); 1708 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1709 PROC_LOCK(p); 1710 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1711 p->p_state == PRS_NEW) { 1712 PROC_UNLOCK(p); 1713 continue; 1714 } 1715 err = p_cansignal(td, p, sig); 1716 if (err == 0) { 1717 if (sig) 1718 pksignal(p, sig, ksi); 1719 ret = err; 1720 } 1721 else if (ret == ESRCH) 1722 ret = err; 1723 PROC_UNLOCK(p); 1724 } 1725 PGRP_UNLOCK(pgrp); 1726 } 1727 return (ret); 1728 } 1729 1730 #ifndef _SYS_SYSPROTO_H_ 1731 struct kill_args { 1732 int pid; 1733 int signum; 1734 }; 1735 #endif 1736 /* ARGSUSED */ 1737 int 1738 sys_kill(struct thread *td, struct kill_args *uap) 1739 { 1740 ksiginfo_t ksi; 1741 struct proc *p; 1742 int error; 1743 1744 /* 1745 * A process in capability mode can send signals only to himself. 1746 * The main rationale behind this is that abort(3) is implemented as 1747 * kill(getpid(), SIGABRT). 1748 */ 1749 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1750 return (ECAPMODE); 1751 1752 AUDIT_ARG_SIGNUM(uap->signum); 1753 AUDIT_ARG_PID(uap->pid); 1754 if ((u_int)uap->signum > _SIG_MAXSIG) 1755 return (EINVAL); 1756 1757 ksiginfo_init(&ksi); 1758 ksi.ksi_signo = uap->signum; 1759 ksi.ksi_code = SI_USER; 1760 ksi.ksi_pid = td->td_proc->p_pid; 1761 ksi.ksi_uid = td->td_ucred->cr_ruid; 1762 1763 if (uap->pid > 0) { 1764 /* kill single process */ 1765 if ((p = pfind_any(uap->pid)) == NULL) 1766 return (ESRCH); 1767 AUDIT_ARG_PROCESS(p); 1768 error = p_cansignal(td, p, uap->signum); 1769 if (error == 0 && uap->signum) 1770 pksignal(p, uap->signum, &ksi); 1771 PROC_UNLOCK(p); 1772 return (error); 1773 } 1774 switch (uap->pid) { 1775 case -1: /* broadcast signal */ 1776 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1777 case 0: /* signal own process group */ 1778 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1779 default: /* negative explicit process group */ 1780 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1781 } 1782 /* NOTREACHED */ 1783 } 1784 1785 int 1786 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1787 { 1788 struct proc *p; 1789 int error; 1790 1791 AUDIT_ARG_SIGNUM(uap->signum); 1792 AUDIT_ARG_FD(uap->fd); 1793 if ((u_int)uap->signum > _SIG_MAXSIG) 1794 return (EINVAL); 1795 1796 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1797 if (error) 1798 return (error); 1799 AUDIT_ARG_PROCESS(p); 1800 error = p_cansignal(td, p, uap->signum); 1801 if (error == 0 && uap->signum) 1802 kern_psignal(p, uap->signum); 1803 PROC_UNLOCK(p); 1804 return (error); 1805 } 1806 1807 #if defined(COMPAT_43) 1808 #ifndef _SYS_SYSPROTO_H_ 1809 struct okillpg_args { 1810 int pgid; 1811 int signum; 1812 }; 1813 #endif 1814 /* ARGSUSED */ 1815 int 1816 okillpg(struct thread *td, struct okillpg_args *uap) 1817 { 1818 ksiginfo_t ksi; 1819 1820 AUDIT_ARG_SIGNUM(uap->signum); 1821 AUDIT_ARG_PID(uap->pgid); 1822 if ((u_int)uap->signum > _SIG_MAXSIG) 1823 return (EINVAL); 1824 1825 ksiginfo_init(&ksi); 1826 ksi.ksi_signo = uap->signum; 1827 ksi.ksi_code = SI_USER; 1828 ksi.ksi_pid = td->td_proc->p_pid; 1829 ksi.ksi_uid = td->td_ucred->cr_ruid; 1830 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1831 } 1832 #endif /* COMPAT_43 */ 1833 1834 #ifndef _SYS_SYSPROTO_H_ 1835 struct sigqueue_args { 1836 pid_t pid; 1837 int signum; 1838 /* union sigval */ void *value; 1839 }; 1840 #endif 1841 int 1842 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1843 { 1844 union sigval sv; 1845 1846 sv.sival_ptr = uap->value; 1847 1848 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1849 } 1850 1851 int 1852 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1853 { 1854 ksiginfo_t ksi; 1855 struct proc *p; 1856 int error; 1857 1858 if ((u_int)signum > _SIG_MAXSIG) 1859 return (EINVAL); 1860 1861 /* 1862 * Specification says sigqueue can only send signal to 1863 * single process. 1864 */ 1865 if (pid <= 0) 1866 return (EINVAL); 1867 1868 if ((p = pfind_any(pid)) == NULL) 1869 return (ESRCH); 1870 error = p_cansignal(td, p, signum); 1871 if (error == 0 && signum != 0) { 1872 ksiginfo_init(&ksi); 1873 ksi.ksi_flags = KSI_SIGQ; 1874 ksi.ksi_signo = signum; 1875 ksi.ksi_code = SI_QUEUE; 1876 ksi.ksi_pid = td->td_proc->p_pid; 1877 ksi.ksi_uid = td->td_ucred->cr_ruid; 1878 ksi.ksi_value = *value; 1879 error = pksignal(p, ksi.ksi_signo, &ksi); 1880 } 1881 PROC_UNLOCK(p); 1882 return (error); 1883 } 1884 1885 /* 1886 * Send a signal to a process group. 1887 */ 1888 void 1889 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1890 { 1891 struct pgrp *pgrp; 1892 1893 if (pgid != 0) { 1894 sx_slock(&proctree_lock); 1895 pgrp = pgfind(pgid); 1896 sx_sunlock(&proctree_lock); 1897 if (pgrp != NULL) { 1898 pgsignal(pgrp, sig, 0, ksi); 1899 PGRP_UNLOCK(pgrp); 1900 } 1901 } 1902 } 1903 1904 /* 1905 * Send a signal to a process group. If checktty is 1, 1906 * limit to members which have a controlling terminal. 1907 */ 1908 void 1909 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1910 { 1911 struct proc *p; 1912 1913 if (pgrp) { 1914 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1915 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1916 PROC_LOCK(p); 1917 if (p->p_state == PRS_NORMAL && 1918 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1919 pksignal(p, sig, ksi); 1920 PROC_UNLOCK(p); 1921 } 1922 } 1923 } 1924 1925 1926 /* 1927 * Recalculate the signal mask and reset the signal disposition after 1928 * usermode frame for delivery is formed. Should be called after 1929 * mach-specific routine, because sysent->sv_sendsig() needs correct 1930 * ps_siginfo and signal mask. 1931 */ 1932 static void 1933 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1934 { 1935 sigset_t mask; 1936 1937 mtx_assert(&ps->ps_mtx, MA_OWNED); 1938 td->td_ru.ru_nsignals++; 1939 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1940 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1941 SIGADDSET(mask, sig); 1942 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1943 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1944 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1945 sigdflt(ps, sig); 1946 } 1947 1948 1949 /* 1950 * Send a signal caused by a trap to the current thread. If it will be 1951 * caught immediately, deliver it with correct code. Otherwise, post it 1952 * normally. 1953 */ 1954 void 1955 trapsignal(struct thread *td, ksiginfo_t *ksi) 1956 { 1957 struct sigacts *ps; 1958 struct proc *p; 1959 int sig; 1960 int code; 1961 1962 p = td->td_proc; 1963 sig = ksi->ksi_signo; 1964 code = ksi->ksi_code; 1965 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1966 1967 PROC_LOCK(p); 1968 ps = p->p_sigacts; 1969 mtx_lock(&ps->ps_mtx); 1970 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1971 !SIGISMEMBER(td->td_sigmask, sig)) { 1972 #ifdef KTRACE 1973 if (KTRPOINT(curthread, KTR_PSIG)) 1974 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1975 &td->td_sigmask, code); 1976 #endif 1977 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1978 ksi, &td->td_sigmask); 1979 postsig_done(sig, td, ps); 1980 mtx_unlock(&ps->ps_mtx); 1981 } else { 1982 /* 1983 * Avoid a possible infinite loop if the thread 1984 * masking the signal or process is ignoring the 1985 * signal. 1986 */ 1987 if (kern_forcesigexit && 1988 (SIGISMEMBER(td->td_sigmask, sig) || 1989 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1990 SIGDELSET(td->td_sigmask, sig); 1991 SIGDELSET(ps->ps_sigcatch, sig); 1992 SIGDELSET(ps->ps_sigignore, sig); 1993 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1994 } 1995 mtx_unlock(&ps->ps_mtx); 1996 p->p_code = code; /* XXX for core dump/debugger */ 1997 p->p_sig = sig; /* XXX to verify code */ 1998 tdsendsignal(p, td, sig, ksi); 1999 } 2000 PROC_UNLOCK(p); 2001 } 2002 2003 static struct thread * 2004 sigtd(struct proc *p, int sig, int prop) 2005 { 2006 struct thread *td, *signal_td; 2007 2008 PROC_LOCK_ASSERT(p, MA_OWNED); 2009 2010 /* 2011 * Check if current thread can handle the signal without 2012 * switching context to another thread. 2013 */ 2014 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2015 return (curthread); 2016 signal_td = NULL; 2017 FOREACH_THREAD_IN_PROC(p, td) { 2018 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2019 signal_td = td; 2020 break; 2021 } 2022 } 2023 if (signal_td == NULL) 2024 signal_td = FIRST_THREAD_IN_PROC(p); 2025 return (signal_td); 2026 } 2027 2028 /* 2029 * Send the signal to the process. If the signal has an action, the action 2030 * is usually performed by the target process rather than the caller; we add 2031 * the signal to the set of pending signals for the process. 2032 * 2033 * Exceptions: 2034 * o When a stop signal is sent to a sleeping process that takes the 2035 * default action, the process is stopped without awakening it. 2036 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2037 * regardless of the signal action (eg, blocked or ignored). 2038 * 2039 * Other ignored signals are discarded immediately. 2040 * 2041 * NB: This function may be entered from the debugger via the "kill" DDB 2042 * command. There is little that can be done to mitigate the possibly messy 2043 * side effects of this unwise possibility. 2044 */ 2045 void 2046 kern_psignal(struct proc *p, int sig) 2047 { 2048 ksiginfo_t ksi; 2049 2050 ksiginfo_init(&ksi); 2051 ksi.ksi_signo = sig; 2052 ksi.ksi_code = SI_KERNEL; 2053 (void) tdsendsignal(p, NULL, sig, &ksi); 2054 } 2055 2056 int 2057 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2058 { 2059 2060 return (tdsendsignal(p, NULL, sig, ksi)); 2061 } 2062 2063 /* Utility function for finding a thread to send signal event to. */ 2064 int 2065 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2066 { 2067 struct thread *td; 2068 2069 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2070 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2071 if (td == NULL) 2072 return (ESRCH); 2073 *ttd = td; 2074 } else { 2075 *ttd = NULL; 2076 PROC_LOCK(p); 2077 } 2078 return (0); 2079 } 2080 2081 void 2082 tdsignal(struct thread *td, int sig) 2083 { 2084 ksiginfo_t ksi; 2085 2086 ksiginfo_init(&ksi); 2087 ksi.ksi_signo = sig; 2088 ksi.ksi_code = SI_KERNEL; 2089 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2090 } 2091 2092 void 2093 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2094 { 2095 2096 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2097 } 2098 2099 int 2100 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2101 { 2102 sig_t action; 2103 sigqueue_t *sigqueue; 2104 int prop; 2105 struct sigacts *ps; 2106 int intrval; 2107 int ret = 0; 2108 int wakeup_swapper; 2109 2110 MPASS(td == NULL || p == td->td_proc); 2111 PROC_LOCK_ASSERT(p, MA_OWNED); 2112 2113 if (!_SIG_VALID(sig)) 2114 panic("%s(): invalid signal %d", __func__, sig); 2115 2116 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2117 2118 /* 2119 * IEEE Std 1003.1-2001: return success when killing a zombie. 2120 */ 2121 if (p->p_state == PRS_ZOMBIE) { 2122 if (ksi && (ksi->ksi_flags & KSI_INS)) 2123 ksiginfo_tryfree(ksi); 2124 return (ret); 2125 } 2126 2127 ps = p->p_sigacts; 2128 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2129 prop = sigprop(sig); 2130 2131 if (td == NULL) { 2132 td = sigtd(p, sig, prop); 2133 sigqueue = &p->p_sigqueue; 2134 } else 2135 sigqueue = &td->td_sigqueue; 2136 2137 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2138 2139 /* 2140 * If the signal is being ignored, 2141 * then we forget about it immediately. 2142 * (Note: we don't set SIGCONT in ps_sigignore, 2143 * and if it is set to SIG_IGN, 2144 * action will be SIG_DFL here.) 2145 */ 2146 mtx_lock(&ps->ps_mtx); 2147 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2148 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2149 2150 mtx_unlock(&ps->ps_mtx); 2151 if (ksi && (ksi->ksi_flags & KSI_INS)) 2152 ksiginfo_tryfree(ksi); 2153 return (ret); 2154 } 2155 if (SIGISMEMBER(td->td_sigmask, sig)) 2156 action = SIG_HOLD; 2157 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2158 action = SIG_CATCH; 2159 else 2160 action = SIG_DFL; 2161 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2162 intrval = EINTR; 2163 else 2164 intrval = ERESTART; 2165 mtx_unlock(&ps->ps_mtx); 2166 2167 if (prop & SIGPROP_CONT) 2168 sigqueue_delete_stopmask_proc(p); 2169 else if (prop & SIGPROP_STOP) { 2170 /* 2171 * If sending a tty stop signal to a member of an orphaned 2172 * process group, discard the signal here if the action 2173 * is default; don't stop the process below if sleeping, 2174 * and don't clear any pending SIGCONT. 2175 */ 2176 if ((prop & SIGPROP_TTYSTOP) && 2177 (p->p_pgrp->pg_jobc == 0) && 2178 (action == SIG_DFL)) { 2179 if (ksi && (ksi->ksi_flags & KSI_INS)) 2180 ksiginfo_tryfree(ksi); 2181 return (ret); 2182 } 2183 sigqueue_delete_proc(p, SIGCONT); 2184 if (p->p_flag & P_CONTINUED) { 2185 p->p_flag &= ~P_CONTINUED; 2186 PROC_LOCK(p->p_pptr); 2187 sigqueue_take(p->p_ksi); 2188 PROC_UNLOCK(p->p_pptr); 2189 } 2190 } 2191 2192 ret = sigqueue_add(sigqueue, sig, ksi); 2193 if (ret != 0) 2194 return (ret); 2195 signotify(td); 2196 /* 2197 * Defer further processing for signals which are held, 2198 * except that stopped processes must be continued by SIGCONT. 2199 */ 2200 if (action == SIG_HOLD && 2201 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2202 return (ret); 2203 2204 /* SIGKILL: Remove procfs STOPEVENTs. */ 2205 if (sig == SIGKILL) { 2206 /* from procfs_ioctl.c: PIOCBIC */ 2207 p->p_stops = 0; 2208 /* from procfs_ioctl.c: PIOCCONT */ 2209 p->p_step = 0; 2210 wakeup(&p->p_step); 2211 } 2212 /* 2213 * Some signals have a process-wide effect and a per-thread 2214 * component. Most processing occurs when the process next 2215 * tries to cross the user boundary, however there are some 2216 * times when processing needs to be done immediately, such as 2217 * waking up threads so that they can cross the user boundary. 2218 * We try to do the per-process part here. 2219 */ 2220 if (P_SHOULDSTOP(p)) { 2221 KASSERT(!(p->p_flag & P_WEXIT), 2222 ("signal to stopped but exiting process")); 2223 if (sig == SIGKILL) { 2224 /* 2225 * If traced process is already stopped, 2226 * then no further action is necessary. 2227 */ 2228 if (p->p_flag & P_TRACED) 2229 goto out; 2230 /* 2231 * SIGKILL sets process running. 2232 * It will die elsewhere. 2233 * All threads must be restarted. 2234 */ 2235 p->p_flag &= ~P_STOPPED_SIG; 2236 goto runfast; 2237 } 2238 2239 if (prop & SIGPROP_CONT) { 2240 /* 2241 * If traced process is already stopped, 2242 * then no further action is necessary. 2243 */ 2244 if (p->p_flag & P_TRACED) 2245 goto out; 2246 /* 2247 * If SIGCONT is default (or ignored), we continue the 2248 * process but don't leave the signal in sigqueue as 2249 * it has no further action. If SIGCONT is held, we 2250 * continue the process and leave the signal in 2251 * sigqueue. If the process catches SIGCONT, let it 2252 * handle the signal itself. If it isn't waiting on 2253 * an event, it goes back to run state. 2254 * Otherwise, process goes back to sleep state. 2255 */ 2256 p->p_flag &= ~P_STOPPED_SIG; 2257 PROC_SLOCK(p); 2258 if (p->p_numthreads == p->p_suspcount) { 2259 PROC_SUNLOCK(p); 2260 p->p_flag |= P_CONTINUED; 2261 p->p_xsig = SIGCONT; 2262 PROC_LOCK(p->p_pptr); 2263 childproc_continued(p); 2264 PROC_UNLOCK(p->p_pptr); 2265 PROC_SLOCK(p); 2266 } 2267 if (action == SIG_DFL) { 2268 thread_unsuspend(p); 2269 PROC_SUNLOCK(p); 2270 sigqueue_delete(sigqueue, sig); 2271 goto out; 2272 } 2273 if (action == SIG_CATCH) { 2274 /* 2275 * The process wants to catch it so it needs 2276 * to run at least one thread, but which one? 2277 */ 2278 PROC_SUNLOCK(p); 2279 goto runfast; 2280 } 2281 /* 2282 * The signal is not ignored or caught. 2283 */ 2284 thread_unsuspend(p); 2285 PROC_SUNLOCK(p); 2286 goto out; 2287 } 2288 2289 if (prop & SIGPROP_STOP) { 2290 /* 2291 * If traced process is already stopped, 2292 * then no further action is necessary. 2293 */ 2294 if (p->p_flag & P_TRACED) 2295 goto out; 2296 /* 2297 * Already stopped, don't need to stop again 2298 * (If we did the shell could get confused). 2299 * Just make sure the signal STOP bit set. 2300 */ 2301 p->p_flag |= P_STOPPED_SIG; 2302 sigqueue_delete(sigqueue, sig); 2303 goto out; 2304 } 2305 2306 /* 2307 * All other kinds of signals: 2308 * If a thread is sleeping interruptibly, simulate a 2309 * wakeup so that when it is continued it will be made 2310 * runnable and can look at the signal. However, don't make 2311 * the PROCESS runnable, leave it stopped. 2312 * It may run a bit until it hits a thread_suspend_check(). 2313 */ 2314 wakeup_swapper = 0; 2315 PROC_SLOCK(p); 2316 thread_lock(td); 2317 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2318 wakeup_swapper = sleepq_abort(td, intrval); 2319 thread_unlock(td); 2320 PROC_SUNLOCK(p); 2321 if (wakeup_swapper) 2322 kick_proc0(); 2323 goto out; 2324 /* 2325 * Mutexes are short lived. Threads waiting on them will 2326 * hit thread_suspend_check() soon. 2327 */ 2328 } else if (p->p_state == PRS_NORMAL) { 2329 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2330 tdsigwakeup(td, sig, action, intrval); 2331 goto out; 2332 } 2333 2334 MPASS(action == SIG_DFL); 2335 2336 if (prop & SIGPROP_STOP) { 2337 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2338 goto out; 2339 p->p_flag |= P_STOPPED_SIG; 2340 p->p_xsig = sig; 2341 PROC_SLOCK(p); 2342 wakeup_swapper = sig_suspend_threads(td, p, 1); 2343 if (p->p_numthreads == p->p_suspcount) { 2344 /* 2345 * only thread sending signal to another 2346 * process can reach here, if thread is sending 2347 * signal to its process, because thread does 2348 * not suspend itself here, p_numthreads 2349 * should never be equal to p_suspcount. 2350 */ 2351 thread_stopped(p); 2352 PROC_SUNLOCK(p); 2353 sigqueue_delete_proc(p, p->p_xsig); 2354 } else 2355 PROC_SUNLOCK(p); 2356 if (wakeup_swapper) 2357 kick_proc0(); 2358 goto out; 2359 } 2360 } else { 2361 /* Not in "NORMAL" state. discard the signal. */ 2362 sigqueue_delete(sigqueue, sig); 2363 goto out; 2364 } 2365 2366 /* 2367 * The process is not stopped so we need to apply the signal to all the 2368 * running threads. 2369 */ 2370 runfast: 2371 tdsigwakeup(td, sig, action, intrval); 2372 PROC_SLOCK(p); 2373 thread_unsuspend(p); 2374 PROC_SUNLOCK(p); 2375 out: 2376 /* If we jump here, proc slock should not be owned. */ 2377 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2378 return (ret); 2379 } 2380 2381 /* 2382 * The force of a signal has been directed against a single 2383 * thread. We need to see what we can do about knocking it 2384 * out of any sleep it may be in etc. 2385 */ 2386 static void 2387 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2388 { 2389 struct proc *p = td->td_proc; 2390 int prop; 2391 int wakeup_swapper; 2392 2393 wakeup_swapper = 0; 2394 PROC_LOCK_ASSERT(p, MA_OWNED); 2395 prop = sigprop(sig); 2396 2397 PROC_SLOCK(p); 2398 thread_lock(td); 2399 /* 2400 * Bring the priority of a thread up if we want it to get 2401 * killed in this lifetime. Be careful to avoid bumping the 2402 * priority of the idle thread, since we still allow to signal 2403 * kernel processes. 2404 */ 2405 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2406 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2407 sched_prio(td, PUSER); 2408 if (TD_ON_SLEEPQ(td)) { 2409 /* 2410 * If thread is sleeping uninterruptibly 2411 * we can't interrupt the sleep... the signal will 2412 * be noticed when the process returns through 2413 * trap() or syscall(). 2414 */ 2415 if ((td->td_flags & TDF_SINTR) == 0) 2416 goto out; 2417 /* 2418 * If SIGCONT is default (or ignored) and process is 2419 * asleep, we are finished; the process should not 2420 * be awakened. 2421 */ 2422 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2423 thread_unlock(td); 2424 PROC_SUNLOCK(p); 2425 sigqueue_delete(&p->p_sigqueue, sig); 2426 /* 2427 * It may be on either list in this state. 2428 * Remove from both for now. 2429 */ 2430 sigqueue_delete(&td->td_sigqueue, sig); 2431 return; 2432 } 2433 2434 /* 2435 * Don't awaken a sleeping thread for SIGSTOP if the 2436 * STOP signal is deferred. 2437 */ 2438 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2439 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2440 goto out; 2441 2442 /* 2443 * Give low priority threads a better chance to run. 2444 */ 2445 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2446 sched_prio(td, PUSER); 2447 2448 wakeup_swapper = sleepq_abort(td, intrval); 2449 } else { 2450 /* 2451 * Other states do nothing with the signal immediately, 2452 * other than kicking ourselves if we are running. 2453 * It will either never be noticed, or noticed very soon. 2454 */ 2455 #ifdef SMP 2456 if (TD_IS_RUNNING(td) && td != curthread) 2457 forward_signal(td); 2458 #endif 2459 } 2460 out: 2461 PROC_SUNLOCK(p); 2462 thread_unlock(td); 2463 if (wakeup_swapper) 2464 kick_proc0(); 2465 } 2466 2467 static int 2468 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2469 { 2470 struct thread *td2; 2471 int wakeup_swapper; 2472 2473 PROC_LOCK_ASSERT(p, MA_OWNED); 2474 PROC_SLOCK_ASSERT(p, MA_OWNED); 2475 MPASS(sending || td == curthread); 2476 2477 wakeup_swapper = 0; 2478 FOREACH_THREAD_IN_PROC(p, td2) { 2479 thread_lock(td2); 2480 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2481 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2482 (td2->td_flags & TDF_SINTR)) { 2483 if (td2->td_flags & TDF_SBDRY) { 2484 /* 2485 * Once a thread is asleep with 2486 * TDF_SBDRY and without TDF_SERESTART 2487 * or TDF_SEINTR set, it should never 2488 * become suspended due to this check. 2489 */ 2490 KASSERT(!TD_IS_SUSPENDED(td2), 2491 ("thread with deferred stops suspended")); 2492 if (TD_SBDRY_INTR(td2)) 2493 wakeup_swapper |= sleepq_abort(td2, 2494 TD_SBDRY_ERRNO(td2)); 2495 } else if (!TD_IS_SUSPENDED(td2)) { 2496 thread_suspend_one(td2); 2497 } 2498 } else if (!TD_IS_SUSPENDED(td2)) { 2499 if (sending || td != td2) 2500 td2->td_flags |= TDF_ASTPENDING; 2501 #ifdef SMP 2502 if (TD_IS_RUNNING(td2) && td2 != td) 2503 forward_signal(td2); 2504 #endif 2505 } 2506 thread_unlock(td2); 2507 } 2508 return (wakeup_swapper); 2509 } 2510 2511 /* 2512 * Stop the process for an event deemed interesting to the debugger. If si is 2513 * non-NULL, this is a signal exchange; the new signal requested by the 2514 * debugger will be returned for handling. If si is NULL, this is some other 2515 * type of interesting event. The debugger may request a signal be delivered in 2516 * that case as well, however it will be deferred until it can be handled. 2517 */ 2518 int 2519 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2520 { 2521 struct proc *p = td->td_proc; 2522 struct thread *td2; 2523 ksiginfo_t ksi; 2524 int prop; 2525 2526 PROC_LOCK_ASSERT(p, MA_OWNED); 2527 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2528 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2529 &p->p_mtx.lock_object, "Stopping for traced signal"); 2530 2531 td->td_xsig = sig; 2532 2533 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2534 td->td_dbgflags |= TDB_XSIG; 2535 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2536 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2537 PROC_SLOCK(p); 2538 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2539 if (P_KILLED(p)) { 2540 /* 2541 * Ensure that, if we've been PT_KILLed, the 2542 * exit status reflects that. Another thread 2543 * may also be in ptracestop(), having just 2544 * received the SIGKILL, but this thread was 2545 * unsuspended first. 2546 */ 2547 td->td_dbgflags &= ~TDB_XSIG; 2548 td->td_xsig = SIGKILL; 2549 p->p_ptevents = 0; 2550 break; 2551 } 2552 if (p->p_flag & P_SINGLE_EXIT && 2553 !(td->td_dbgflags & TDB_EXIT)) { 2554 /* 2555 * Ignore ptrace stops except for thread exit 2556 * events when the process exits. 2557 */ 2558 td->td_dbgflags &= ~TDB_XSIG; 2559 PROC_SUNLOCK(p); 2560 return (0); 2561 } 2562 2563 /* 2564 * Make wait(2) work. Ensure that right after the 2565 * attach, the thread which was decided to become the 2566 * leader of attach gets reported to the waiter. 2567 * Otherwise, just avoid overwriting another thread's 2568 * assignment to p_xthread. If another thread has 2569 * already set p_xthread, the current thread will get 2570 * a chance to report itself upon the next iteration. 2571 */ 2572 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2573 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2574 p->p_xthread == NULL)) { 2575 p->p_xsig = sig; 2576 p->p_xthread = td; 2577 td->td_dbgflags &= ~TDB_FSTP; 2578 p->p_flag2 &= ~P2_PTRACE_FSTP; 2579 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2580 sig_suspend_threads(td, p, 0); 2581 } 2582 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2583 td->td_dbgflags &= ~TDB_STOPATFORK; 2584 cv_broadcast(&p->p_dbgwait); 2585 } 2586 stopme: 2587 thread_suspend_switch(td, p); 2588 if (p->p_xthread == td) 2589 p->p_xthread = NULL; 2590 if (!(p->p_flag & P_TRACED)) 2591 break; 2592 if (td->td_dbgflags & TDB_SUSPEND) { 2593 if (p->p_flag & P_SINGLE_EXIT) 2594 break; 2595 goto stopme; 2596 } 2597 } 2598 PROC_SUNLOCK(p); 2599 } 2600 2601 if (si != NULL && sig == td->td_xsig) { 2602 /* Parent wants us to take the original signal unchanged. */ 2603 si->ksi_flags |= KSI_HEAD; 2604 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2605 si->ksi_signo = 0; 2606 } else if (td->td_xsig != 0) { 2607 /* 2608 * If parent wants us to take a new signal, then it will leave 2609 * it in td->td_xsig; otherwise we just look for signals again. 2610 */ 2611 ksiginfo_init(&ksi); 2612 ksi.ksi_signo = td->td_xsig; 2613 ksi.ksi_flags |= KSI_PTRACE; 2614 prop = sigprop(td->td_xsig); 2615 td2 = sigtd(p, td->td_xsig, prop); 2616 tdsendsignal(p, td2, td->td_xsig, &ksi); 2617 if (td != td2) 2618 return (0); 2619 } 2620 2621 return (td->td_xsig); 2622 } 2623 2624 static void 2625 reschedule_signals(struct proc *p, sigset_t block, int flags) 2626 { 2627 struct sigacts *ps; 2628 struct thread *td; 2629 int sig; 2630 2631 PROC_LOCK_ASSERT(p, MA_OWNED); 2632 ps = p->p_sigacts; 2633 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2634 MA_OWNED : MA_NOTOWNED); 2635 if (SIGISEMPTY(p->p_siglist)) 2636 return; 2637 SIGSETAND(block, p->p_siglist); 2638 while ((sig = sig_ffs(&block)) != 0) { 2639 SIGDELSET(block, sig); 2640 td = sigtd(p, sig, 0); 2641 signotify(td); 2642 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2643 mtx_lock(&ps->ps_mtx); 2644 if (p->p_flag & P_TRACED || 2645 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2646 !SIGISMEMBER(td->td_sigmask, sig))) 2647 tdsigwakeup(td, sig, SIG_CATCH, 2648 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2649 ERESTART)); 2650 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2651 mtx_unlock(&ps->ps_mtx); 2652 } 2653 } 2654 2655 void 2656 tdsigcleanup(struct thread *td) 2657 { 2658 struct proc *p; 2659 sigset_t unblocked; 2660 2661 p = td->td_proc; 2662 PROC_LOCK_ASSERT(p, MA_OWNED); 2663 2664 sigqueue_flush(&td->td_sigqueue); 2665 if (p->p_numthreads == 1) 2666 return; 2667 2668 /* 2669 * Since we cannot handle signals, notify signal post code 2670 * about this by filling the sigmask. 2671 * 2672 * Also, if needed, wake up thread(s) that do not block the 2673 * same signals as the exiting thread, since the thread might 2674 * have been selected for delivery and woken up. 2675 */ 2676 SIGFILLSET(unblocked); 2677 SIGSETNAND(unblocked, td->td_sigmask); 2678 SIGFILLSET(td->td_sigmask); 2679 reschedule_signals(p, unblocked, 0); 2680 2681 } 2682 2683 static int 2684 sigdeferstop_curr_flags(int cflags) 2685 { 2686 2687 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2688 (cflags & TDF_SBDRY) != 0); 2689 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2690 } 2691 2692 /* 2693 * Defer the delivery of SIGSTOP for the current thread, according to 2694 * the requested mode. Returns previous flags, which must be restored 2695 * by sigallowstop(). 2696 * 2697 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2698 * cleared by the current thread, which allow the lock-less read-only 2699 * accesses below. 2700 */ 2701 int 2702 sigdeferstop_impl(int mode) 2703 { 2704 struct thread *td; 2705 int cflags, nflags; 2706 2707 td = curthread; 2708 cflags = sigdeferstop_curr_flags(td->td_flags); 2709 switch (mode) { 2710 case SIGDEFERSTOP_NOP: 2711 nflags = cflags; 2712 break; 2713 case SIGDEFERSTOP_OFF: 2714 nflags = 0; 2715 break; 2716 case SIGDEFERSTOP_SILENT: 2717 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2718 break; 2719 case SIGDEFERSTOP_EINTR: 2720 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2721 break; 2722 case SIGDEFERSTOP_ERESTART: 2723 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2724 break; 2725 default: 2726 panic("sigdeferstop: invalid mode %x", mode); 2727 break; 2728 } 2729 if (cflags == nflags) 2730 return (SIGDEFERSTOP_VAL_NCHG); 2731 thread_lock(td); 2732 td->td_flags = (td->td_flags & ~cflags) | nflags; 2733 thread_unlock(td); 2734 return (cflags); 2735 } 2736 2737 /* 2738 * Restores the STOP handling mode, typically permitting the delivery 2739 * of SIGSTOP for the current thread. This does not immediately 2740 * suspend if a stop was posted. Instead, the thread will suspend 2741 * either via ast() or a subsequent interruptible sleep. 2742 */ 2743 void 2744 sigallowstop_impl(int prev) 2745 { 2746 struct thread *td; 2747 int cflags; 2748 2749 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2750 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2751 ("sigallowstop: incorrect previous mode %x", prev)); 2752 td = curthread; 2753 cflags = sigdeferstop_curr_flags(td->td_flags); 2754 if (cflags != prev) { 2755 thread_lock(td); 2756 td->td_flags = (td->td_flags & ~cflags) | prev; 2757 thread_unlock(td); 2758 } 2759 } 2760 2761 /* 2762 * If the current process has received a signal (should be caught or cause 2763 * termination, should interrupt current syscall), return the signal number. 2764 * Stop signals with default action are processed immediately, then cleared; 2765 * they aren't returned. This is checked after each entry to the system for 2766 * a syscall or trap (though this can usually be done without calling issignal 2767 * by checking the pending signal masks in cursig.) The normal call 2768 * sequence is 2769 * 2770 * while (sig = cursig(curthread)) 2771 * postsig(sig); 2772 */ 2773 static int 2774 issignal(struct thread *td) 2775 { 2776 struct proc *p; 2777 struct sigacts *ps; 2778 struct sigqueue *queue; 2779 sigset_t sigpending; 2780 ksiginfo_t ksi; 2781 int prop, sig, traced; 2782 2783 p = td->td_proc; 2784 ps = p->p_sigacts; 2785 mtx_assert(&ps->ps_mtx, MA_OWNED); 2786 PROC_LOCK_ASSERT(p, MA_OWNED); 2787 for (;;) { 2788 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2789 2790 sigpending = td->td_sigqueue.sq_signals; 2791 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2792 SIGSETNAND(sigpending, td->td_sigmask); 2793 2794 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2795 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2796 SIG_STOPSIGMASK(sigpending); 2797 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2798 return (0); 2799 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2800 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2801 SIGISMEMBER(sigpending, SIGSTOP)) { 2802 /* 2803 * If debugger just attached, always consume 2804 * SIGSTOP from ptrace(PT_ATTACH) first, to 2805 * execute the debugger attach ritual in 2806 * order. 2807 */ 2808 sig = SIGSTOP; 2809 td->td_dbgflags |= TDB_FSTP; 2810 } else { 2811 sig = sig_ffs(&sigpending); 2812 } 2813 2814 if (p->p_stops & S_SIG) { 2815 mtx_unlock(&ps->ps_mtx); 2816 stopevent(p, S_SIG, sig); 2817 mtx_lock(&ps->ps_mtx); 2818 } 2819 2820 /* 2821 * We should see pending but ignored signals 2822 * only if P_TRACED was on when they were posted. 2823 */ 2824 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2825 sigqueue_delete(&td->td_sigqueue, sig); 2826 sigqueue_delete(&p->p_sigqueue, sig); 2827 continue; 2828 } 2829 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2830 /* 2831 * If traced, always stop. 2832 * Remove old signal from queue before the stop. 2833 * XXX shrug off debugger, it causes siginfo to 2834 * be thrown away. 2835 */ 2836 queue = &td->td_sigqueue; 2837 ksiginfo_init(&ksi); 2838 if (sigqueue_get(queue, sig, &ksi) == 0) { 2839 queue = &p->p_sigqueue; 2840 sigqueue_get(queue, sig, &ksi); 2841 } 2842 td->td_si = ksi.ksi_info; 2843 2844 mtx_unlock(&ps->ps_mtx); 2845 sig = ptracestop(td, sig, &ksi); 2846 mtx_lock(&ps->ps_mtx); 2847 2848 /* 2849 * Keep looking if the debugger discarded or 2850 * replaced the signal. 2851 */ 2852 if (sig == 0) 2853 continue; 2854 2855 /* 2856 * If the signal became masked, re-queue it. 2857 */ 2858 if (SIGISMEMBER(td->td_sigmask, sig)) { 2859 ksi.ksi_flags |= KSI_HEAD; 2860 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2861 continue; 2862 } 2863 2864 /* 2865 * If the traced bit got turned off, requeue 2866 * the signal and go back up to the top to 2867 * rescan signals. This ensures that p_sig* 2868 * and p_sigact are consistent. 2869 */ 2870 if ((p->p_flag & P_TRACED) == 0) { 2871 ksi.ksi_flags |= KSI_HEAD; 2872 sigqueue_add(queue, sig, &ksi); 2873 continue; 2874 } 2875 } 2876 2877 prop = sigprop(sig); 2878 2879 /* 2880 * Decide whether the signal should be returned. 2881 * Return the signal's number, or fall through 2882 * to clear it from the pending mask. 2883 */ 2884 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2885 2886 case (intptr_t)SIG_DFL: 2887 /* 2888 * Don't take default actions on system processes. 2889 */ 2890 if (p->p_pid <= 1) { 2891 #ifdef DIAGNOSTIC 2892 /* 2893 * Are you sure you want to ignore SIGSEGV 2894 * in init? XXX 2895 */ 2896 printf("Process (pid %lu) got signal %d\n", 2897 (u_long)p->p_pid, sig); 2898 #endif 2899 break; /* == ignore */ 2900 } 2901 /* 2902 * If there is a pending stop signal to process with 2903 * default action, stop here, then clear the signal. 2904 * Traced or exiting processes should ignore stops. 2905 * Additionally, a member of an orphaned process group 2906 * should ignore tty stops. 2907 */ 2908 if (prop & SIGPROP_STOP) { 2909 if (p->p_flag & 2910 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2911 (p->p_pgrp->pg_jobc == 0 && 2912 prop & SIGPROP_TTYSTOP)) 2913 break; /* == ignore */ 2914 if (TD_SBDRY_INTR(td)) { 2915 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2916 ("lost TDF_SBDRY")); 2917 return (-1); 2918 } 2919 mtx_unlock(&ps->ps_mtx); 2920 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2921 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2922 sigqueue_delete(&td->td_sigqueue, sig); 2923 sigqueue_delete(&p->p_sigqueue, sig); 2924 p->p_flag |= P_STOPPED_SIG; 2925 p->p_xsig = sig; 2926 PROC_SLOCK(p); 2927 sig_suspend_threads(td, p, 0); 2928 thread_suspend_switch(td, p); 2929 PROC_SUNLOCK(p); 2930 mtx_lock(&ps->ps_mtx); 2931 goto next; 2932 } else if (prop & SIGPROP_IGNORE) { 2933 /* 2934 * Except for SIGCONT, shouldn't get here. 2935 * Default action is to ignore; drop it. 2936 */ 2937 break; /* == ignore */ 2938 } else 2939 return (sig); 2940 /*NOTREACHED*/ 2941 2942 case (intptr_t)SIG_IGN: 2943 /* 2944 * Masking above should prevent us ever trying 2945 * to take action on an ignored signal other 2946 * than SIGCONT, unless process is traced. 2947 */ 2948 if ((prop & SIGPROP_CONT) == 0 && 2949 (p->p_flag & P_TRACED) == 0) 2950 printf("issignal\n"); 2951 break; /* == ignore */ 2952 2953 default: 2954 /* 2955 * This signal has an action, let 2956 * postsig() process it. 2957 */ 2958 return (sig); 2959 } 2960 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2961 sigqueue_delete(&p->p_sigqueue, sig); 2962 next:; 2963 } 2964 /* NOTREACHED */ 2965 } 2966 2967 void 2968 thread_stopped(struct proc *p) 2969 { 2970 int n; 2971 2972 PROC_LOCK_ASSERT(p, MA_OWNED); 2973 PROC_SLOCK_ASSERT(p, MA_OWNED); 2974 n = p->p_suspcount; 2975 if (p == curproc) 2976 n++; 2977 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2978 PROC_SUNLOCK(p); 2979 p->p_flag &= ~P_WAITED; 2980 PROC_LOCK(p->p_pptr); 2981 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2982 CLD_TRAPPED : CLD_STOPPED); 2983 PROC_UNLOCK(p->p_pptr); 2984 PROC_SLOCK(p); 2985 } 2986 } 2987 2988 /* 2989 * Take the action for the specified signal 2990 * from the current set of pending signals. 2991 */ 2992 int 2993 postsig(int sig) 2994 { 2995 struct thread *td; 2996 struct proc *p; 2997 struct sigacts *ps; 2998 sig_t action; 2999 ksiginfo_t ksi; 3000 sigset_t returnmask; 3001 3002 KASSERT(sig != 0, ("postsig")); 3003 3004 td = curthread; 3005 p = td->td_proc; 3006 PROC_LOCK_ASSERT(p, MA_OWNED); 3007 ps = p->p_sigacts; 3008 mtx_assert(&ps->ps_mtx, MA_OWNED); 3009 ksiginfo_init(&ksi); 3010 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3011 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3012 return (0); 3013 ksi.ksi_signo = sig; 3014 if (ksi.ksi_code == SI_TIMER) 3015 itimer_accept(p, ksi.ksi_timerid, &ksi); 3016 action = ps->ps_sigact[_SIG_IDX(sig)]; 3017 #ifdef KTRACE 3018 if (KTRPOINT(td, KTR_PSIG)) 3019 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3020 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3021 #endif 3022 if ((p->p_stops & S_SIG) != 0) { 3023 mtx_unlock(&ps->ps_mtx); 3024 stopevent(p, S_SIG, sig); 3025 mtx_lock(&ps->ps_mtx); 3026 } 3027 3028 if (action == SIG_DFL) { 3029 /* 3030 * Default action, where the default is to kill 3031 * the process. (Other cases were ignored above.) 3032 */ 3033 mtx_unlock(&ps->ps_mtx); 3034 proc_td_siginfo_capture(td, &ksi.ksi_info); 3035 sigexit(td, sig); 3036 /* NOTREACHED */ 3037 } else { 3038 /* 3039 * If we get here, the signal must be caught. 3040 */ 3041 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3042 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3043 ("postsig action: blocked sig %d", sig)); 3044 3045 /* 3046 * Set the new mask value and also defer further 3047 * occurrences of this signal. 3048 * 3049 * Special case: user has done a sigsuspend. Here the 3050 * current mask is not of interest, but rather the 3051 * mask from before the sigsuspend is what we want 3052 * restored after the signal processing is completed. 3053 */ 3054 if (td->td_pflags & TDP_OLDMASK) { 3055 returnmask = td->td_oldsigmask; 3056 td->td_pflags &= ~TDP_OLDMASK; 3057 } else 3058 returnmask = td->td_sigmask; 3059 3060 if (p->p_sig == sig) { 3061 p->p_code = 0; 3062 p->p_sig = 0; 3063 } 3064 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3065 postsig_done(sig, td, ps); 3066 } 3067 return (1); 3068 } 3069 3070 /* 3071 * Kill the current process for stated reason. 3072 */ 3073 void 3074 killproc(struct proc *p, char *why) 3075 { 3076 3077 PROC_LOCK_ASSERT(p, MA_OWNED); 3078 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3079 p->p_comm); 3080 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3081 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3082 p->p_flag |= P_WKILLED; 3083 kern_psignal(p, SIGKILL); 3084 } 3085 3086 /* 3087 * Force the current process to exit with the specified signal, dumping core 3088 * if appropriate. We bypass the normal tests for masked and caught signals, 3089 * allowing unrecoverable failures to terminate the process without changing 3090 * signal state. Mark the accounting record with the signal termination. 3091 * If dumping core, save the signal number for the debugger. Calls exit and 3092 * does not return. 3093 */ 3094 void 3095 sigexit(struct thread *td, int sig) 3096 { 3097 struct proc *p = td->td_proc; 3098 3099 PROC_LOCK_ASSERT(p, MA_OWNED); 3100 p->p_acflag |= AXSIG; 3101 /* 3102 * We must be single-threading to generate a core dump. This 3103 * ensures that the registers in the core file are up-to-date. 3104 * Also, the ELF dump handler assumes that the thread list doesn't 3105 * change out from under it. 3106 * 3107 * XXX If another thread attempts to single-thread before us 3108 * (e.g. via fork()), we won't get a dump at all. 3109 */ 3110 if ((sigprop(sig) & SIGPROP_CORE) && 3111 thread_single(p, SINGLE_NO_EXIT) == 0) { 3112 p->p_sig = sig; 3113 /* 3114 * Log signals which would cause core dumps 3115 * (Log as LOG_INFO to appease those who don't want 3116 * these messages.) 3117 * XXX : Todo, as well as euid, write out ruid too 3118 * Note that coredump() drops proc lock. 3119 */ 3120 if (coredump(td) == 0) 3121 sig |= WCOREFLAG; 3122 if (kern_logsigexit) 3123 log(LOG_INFO, 3124 "pid %d (%s), uid %d: exited on signal %d%s\n", 3125 p->p_pid, p->p_comm, 3126 td->td_ucred ? td->td_ucred->cr_uid : -1, 3127 sig &~ WCOREFLAG, 3128 sig & WCOREFLAG ? " (core dumped)" : ""); 3129 } else 3130 PROC_UNLOCK(p); 3131 exit1(td, 0, sig); 3132 /* NOTREACHED */ 3133 } 3134 3135 /* 3136 * Send queued SIGCHLD to parent when child process's state 3137 * is changed. 3138 */ 3139 static void 3140 sigparent(struct proc *p, int reason, int status) 3141 { 3142 PROC_LOCK_ASSERT(p, MA_OWNED); 3143 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3144 3145 if (p->p_ksi != NULL) { 3146 p->p_ksi->ksi_signo = SIGCHLD; 3147 p->p_ksi->ksi_code = reason; 3148 p->p_ksi->ksi_status = status; 3149 p->p_ksi->ksi_pid = p->p_pid; 3150 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3151 if (KSI_ONQ(p->p_ksi)) 3152 return; 3153 } 3154 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3155 } 3156 3157 static void 3158 childproc_jobstate(struct proc *p, int reason, int sig) 3159 { 3160 struct sigacts *ps; 3161 3162 PROC_LOCK_ASSERT(p, MA_OWNED); 3163 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3164 3165 /* 3166 * Wake up parent sleeping in kern_wait(), also send 3167 * SIGCHLD to parent, but SIGCHLD does not guarantee 3168 * that parent will awake, because parent may masked 3169 * the signal. 3170 */ 3171 p->p_pptr->p_flag |= P_STATCHILD; 3172 wakeup(p->p_pptr); 3173 3174 ps = p->p_pptr->p_sigacts; 3175 mtx_lock(&ps->ps_mtx); 3176 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3177 mtx_unlock(&ps->ps_mtx); 3178 sigparent(p, reason, sig); 3179 } else 3180 mtx_unlock(&ps->ps_mtx); 3181 } 3182 3183 void 3184 childproc_stopped(struct proc *p, int reason) 3185 { 3186 3187 childproc_jobstate(p, reason, p->p_xsig); 3188 } 3189 3190 void 3191 childproc_continued(struct proc *p) 3192 { 3193 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3194 } 3195 3196 void 3197 childproc_exited(struct proc *p) 3198 { 3199 int reason, status; 3200 3201 if (WCOREDUMP(p->p_xsig)) { 3202 reason = CLD_DUMPED; 3203 status = WTERMSIG(p->p_xsig); 3204 } else if (WIFSIGNALED(p->p_xsig)) { 3205 reason = CLD_KILLED; 3206 status = WTERMSIG(p->p_xsig); 3207 } else { 3208 reason = CLD_EXITED; 3209 status = p->p_xexit; 3210 } 3211 /* 3212 * XXX avoid calling wakeup(p->p_pptr), the work is 3213 * done in exit1(). 3214 */ 3215 sigparent(p, reason, status); 3216 } 3217 3218 /* 3219 * We only have 1 character for the core count in the format 3220 * string, so the range will be 0-9 3221 */ 3222 #define MAX_NUM_CORE_FILES 10 3223 #ifndef NUM_CORE_FILES 3224 #define NUM_CORE_FILES 5 3225 #endif 3226 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3227 static int num_cores = NUM_CORE_FILES; 3228 3229 static int 3230 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3231 { 3232 int error; 3233 int new_val; 3234 3235 new_val = num_cores; 3236 error = sysctl_handle_int(oidp, &new_val, 0, req); 3237 if (error != 0 || req->newptr == NULL) 3238 return (error); 3239 if (new_val > MAX_NUM_CORE_FILES) 3240 new_val = MAX_NUM_CORE_FILES; 3241 if (new_val < 0) 3242 new_val = 0; 3243 num_cores = new_val; 3244 return (0); 3245 } 3246 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3247 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3248 3249 #define GZIP_SUFFIX ".gz" 3250 #define ZSTD_SUFFIX ".zst" 3251 3252 int compress_user_cores = 0; 3253 3254 static int 3255 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3256 { 3257 int error, val; 3258 3259 val = compress_user_cores; 3260 error = sysctl_handle_int(oidp, &val, 0, req); 3261 if (error != 0 || req->newptr == NULL) 3262 return (error); 3263 if (val != 0 && !compressor_avail(val)) 3264 return (EINVAL); 3265 compress_user_cores = val; 3266 return (error); 3267 } 3268 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3269 0, sizeof(int), sysctl_compress_user_cores, "I", 3270 "Enable compression of user corefiles (" 3271 __XSTRING(COMPRESS_GZIP) " = gzip, " 3272 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3273 3274 int compress_user_cores_level = 6; 3275 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3276 &compress_user_cores_level, 0, 3277 "Corefile compression level"); 3278 3279 /* 3280 * Protect the access to corefilename[] by allproc_lock. 3281 */ 3282 #define corefilename_lock allproc_lock 3283 3284 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3285 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3286 3287 static int 3288 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3289 { 3290 int error; 3291 3292 sx_xlock(&corefilename_lock); 3293 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3294 req); 3295 sx_xunlock(&corefilename_lock); 3296 3297 return (error); 3298 } 3299 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3300 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3301 "Process corefile name format string"); 3302 3303 /* 3304 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3305 * Expand the name described in corefilename, using name, uid, and pid 3306 * and open/create core file. 3307 * corefilename is a printf-like string, with three format specifiers: 3308 * %N name of process ("name") 3309 * %P process id (pid) 3310 * %U user id (uid) 3311 * For example, "%N.core" is the default; they can be disabled completely 3312 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3313 * This is controlled by the sysctl variable kern.corefile (see above). 3314 */ 3315 static int 3316 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3317 int compress, struct vnode **vpp, char **namep) 3318 { 3319 struct nameidata nd; 3320 struct sbuf sb; 3321 const char *format; 3322 char *hostname, *name; 3323 int indexpos, i, error, cmode, flags, oflags; 3324 3325 hostname = NULL; 3326 format = corefilename; 3327 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3328 indexpos = -1; 3329 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3330 sx_slock(&corefilename_lock); 3331 for (i = 0; format[i] != '\0'; i++) { 3332 switch (format[i]) { 3333 case '%': /* Format character */ 3334 i++; 3335 switch (format[i]) { 3336 case '%': 3337 sbuf_putc(&sb, '%'); 3338 break; 3339 case 'H': /* hostname */ 3340 if (hostname == NULL) { 3341 hostname = malloc(MAXHOSTNAMELEN, 3342 M_TEMP, M_WAITOK); 3343 } 3344 getcredhostname(td->td_ucred, hostname, 3345 MAXHOSTNAMELEN); 3346 sbuf_printf(&sb, "%s", hostname); 3347 break; 3348 case 'I': /* autoincrementing index */ 3349 sbuf_printf(&sb, "0"); 3350 indexpos = sbuf_len(&sb) - 1; 3351 break; 3352 case 'N': /* process name */ 3353 sbuf_printf(&sb, "%s", comm); 3354 break; 3355 case 'P': /* process id */ 3356 sbuf_printf(&sb, "%u", pid); 3357 break; 3358 case 'U': /* user id */ 3359 sbuf_printf(&sb, "%u", uid); 3360 break; 3361 default: 3362 log(LOG_ERR, 3363 "Unknown format character %c in " 3364 "corename `%s'\n", format[i], format); 3365 break; 3366 } 3367 break; 3368 default: 3369 sbuf_putc(&sb, format[i]); 3370 break; 3371 } 3372 } 3373 sx_sunlock(&corefilename_lock); 3374 free(hostname, M_TEMP); 3375 if (compress == COMPRESS_GZIP) 3376 sbuf_printf(&sb, GZIP_SUFFIX); 3377 else if (compress == COMPRESS_ZSTD) 3378 sbuf_printf(&sb, ZSTD_SUFFIX); 3379 if (sbuf_error(&sb) != 0) { 3380 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3381 "long\n", (long)pid, comm, (u_long)uid); 3382 sbuf_delete(&sb); 3383 free(name, M_TEMP); 3384 return (ENOMEM); 3385 } 3386 sbuf_finish(&sb); 3387 sbuf_delete(&sb); 3388 3389 cmode = S_IRUSR | S_IWUSR; 3390 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3391 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3392 3393 /* 3394 * If the core format has a %I in it, then we need to check 3395 * for existing corefiles before returning a name. 3396 * To do this we iterate over 0..num_cores to find a 3397 * non-existing core file name to use. 3398 */ 3399 if (indexpos != -1) { 3400 for (i = 0; i < num_cores; i++) { 3401 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3402 name[indexpos] = '0' + i; 3403 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3404 error = vn_open_cred(&nd, &flags, cmode, oflags, 3405 td->td_ucred, NULL); 3406 if (error) { 3407 if (error == EEXIST) 3408 continue; 3409 log(LOG_ERR, 3410 "pid %d (%s), uid (%u): Path `%s' failed " 3411 "on initial open test, error = %d\n", 3412 pid, comm, uid, name, error); 3413 } 3414 goto out; 3415 } 3416 } 3417 3418 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3419 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3420 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3421 out: 3422 if (error) { 3423 #ifdef AUDIT 3424 audit_proc_coredump(td, name, error); 3425 #endif 3426 free(name, M_TEMP); 3427 return (error); 3428 } 3429 NDFREE(&nd, NDF_ONLY_PNBUF); 3430 *vpp = nd.ni_vp; 3431 *namep = name; 3432 return (0); 3433 } 3434 3435 static int 3436 coredump_sanitise_path(const char *path) 3437 { 3438 size_t i; 3439 3440 /* 3441 * Only send a subset of ASCII to devd(8) because it 3442 * might pass these strings to sh -c. 3443 */ 3444 for (i = 0; path[i]; i++) 3445 if (!(isalpha(path[i]) || isdigit(path[i])) && 3446 path[i] != '/' && path[i] != '.' && 3447 path[i] != '-') 3448 return (0); 3449 3450 return (1); 3451 } 3452 3453 /* 3454 * Dump a process' core. The main routine does some 3455 * policy checking, and creates the name of the coredump; 3456 * then it passes on a vnode and a size limit to the process-specific 3457 * coredump routine if there is one; if there _is not_ one, it returns 3458 * ENOSYS; otherwise it returns the error from the process-specific routine. 3459 */ 3460 3461 static int 3462 coredump(struct thread *td) 3463 { 3464 struct proc *p = td->td_proc; 3465 struct ucred *cred = td->td_ucred; 3466 struct vnode *vp; 3467 struct flock lf; 3468 struct vattr vattr; 3469 int error, error1, locked; 3470 char *name; /* name of corefile */ 3471 void *rl_cookie; 3472 off_t limit; 3473 char *data = NULL; 3474 char *fullpath, *freepath = NULL; 3475 size_t len; 3476 static const char comm_name[] = "comm="; 3477 static const char core_name[] = "core="; 3478 3479 PROC_LOCK_ASSERT(p, MA_OWNED); 3480 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3481 _STOPEVENT(p, S_CORE, 0); 3482 3483 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3484 (p->p_flag2 & P2_NOTRACE) != 0) { 3485 PROC_UNLOCK(p); 3486 return (EFAULT); 3487 } 3488 3489 /* 3490 * Note that the bulk of limit checking is done after 3491 * the corefile is created. The exception is if the limit 3492 * for corefiles is 0, in which case we don't bother 3493 * creating the corefile at all. This layout means that 3494 * a corefile is truncated instead of not being created, 3495 * if it is larger than the limit. 3496 */ 3497 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3498 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3499 PROC_UNLOCK(p); 3500 return (EFBIG); 3501 } 3502 PROC_UNLOCK(p); 3503 3504 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3505 compress_user_cores, &vp, &name); 3506 if (error != 0) 3507 return (error); 3508 3509 /* 3510 * Don't dump to non-regular files or files with links. 3511 * Do not dump into system files. 3512 */ 3513 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3514 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3515 VOP_UNLOCK(vp, 0); 3516 error = EFAULT; 3517 goto out; 3518 } 3519 3520 VOP_UNLOCK(vp, 0); 3521 3522 /* Postpone other writers, including core dumps of other processes. */ 3523 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3524 3525 lf.l_whence = SEEK_SET; 3526 lf.l_start = 0; 3527 lf.l_len = 0; 3528 lf.l_type = F_WRLCK; 3529 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3530 3531 VATTR_NULL(&vattr); 3532 vattr.va_size = 0; 3533 if (set_core_nodump_flag) 3534 vattr.va_flags = UF_NODUMP; 3535 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3536 VOP_SETATTR(vp, &vattr, cred); 3537 VOP_UNLOCK(vp, 0); 3538 PROC_LOCK(p); 3539 p->p_acflag |= ACORE; 3540 PROC_UNLOCK(p); 3541 3542 if (p->p_sysent->sv_coredump != NULL) { 3543 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3544 } else { 3545 error = ENOSYS; 3546 } 3547 3548 if (locked) { 3549 lf.l_type = F_UNLCK; 3550 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3551 } 3552 vn_rangelock_unlock(vp, rl_cookie); 3553 3554 /* 3555 * Notify the userland helper that a process triggered a core dump. 3556 * This allows the helper to run an automated debugging session. 3557 */ 3558 if (error != 0 || coredump_devctl == 0) 3559 goto out; 3560 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3561 sizeof(' ') + sizeof(core_name) - 1; 3562 data = malloc(len, M_TEMP, M_WAITOK); 3563 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3564 goto out; 3565 if (!coredump_sanitise_path(fullpath)) 3566 goto out; 3567 snprintf(data, len, "%s%s ", comm_name, fullpath); 3568 free(freepath, M_TEMP); 3569 freepath = NULL; 3570 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3571 goto out; 3572 if (!coredump_sanitise_path(fullpath)) 3573 goto out; 3574 strlcat(data, core_name, len); 3575 strlcat(data, fullpath, len); 3576 devctl_notify("kernel", "signal", "coredump", data); 3577 out: 3578 error1 = vn_close(vp, FWRITE, cred, td); 3579 if (error == 0) 3580 error = error1; 3581 #ifdef AUDIT 3582 audit_proc_coredump(td, name, error); 3583 #endif 3584 free(freepath, M_TEMP); 3585 free(data, M_TEMP); 3586 free(name, M_TEMP); 3587 return (error); 3588 } 3589 3590 /* 3591 * Nonexistent system call-- signal process (may want to handle it). Flag 3592 * error in case process won't see signal immediately (blocked or ignored). 3593 */ 3594 #ifndef _SYS_SYSPROTO_H_ 3595 struct nosys_args { 3596 int dummy; 3597 }; 3598 #endif 3599 /* ARGSUSED */ 3600 int 3601 nosys(struct thread *td, struct nosys_args *args) 3602 { 3603 struct proc *p; 3604 3605 p = td->td_proc; 3606 3607 PROC_LOCK(p); 3608 tdsignal(td, SIGSYS); 3609 PROC_UNLOCK(p); 3610 if (kern_lognosys == 1 || kern_lognosys == 3) { 3611 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3612 td->td_sa.code); 3613 } 3614 if (kern_lognosys == 2 || kern_lognosys == 3) { 3615 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3616 td->td_sa.code); 3617 } 3618 return (ENOSYS); 3619 } 3620 3621 /* 3622 * Send a SIGIO or SIGURG signal to a process or process group using stored 3623 * credentials rather than those of the current process. 3624 */ 3625 void 3626 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3627 { 3628 ksiginfo_t ksi; 3629 struct sigio *sigio; 3630 3631 ksiginfo_init(&ksi); 3632 ksi.ksi_signo = sig; 3633 ksi.ksi_code = SI_KERNEL; 3634 3635 SIGIO_LOCK(); 3636 sigio = *sigiop; 3637 if (sigio == NULL) { 3638 SIGIO_UNLOCK(); 3639 return; 3640 } 3641 if (sigio->sio_pgid > 0) { 3642 PROC_LOCK(sigio->sio_proc); 3643 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3644 kern_psignal(sigio->sio_proc, sig); 3645 PROC_UNLOCK(sigio->sio_proc); 3646 } else if (sigio->sio_pgid < 0) { 3647 struct proc *p; 3648 3649 PGRP_LOCK(sigio->sio_pgrp); 3650 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3651 PROC_LOCK(p); 3652 if (p->p_state == PRS_NORMAL && 3653 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3654 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3655 kern_psignal(p, sig); 3656 PROC_UNLOCK(p); 3657 } 3658 PGRP_UNLOCK(sigio->sio_pgrp); 3659 } 3660 SIGIO_UNLOCK(); 3661 } 3662 3663 static int 3664 filt_sigattach(struct knote *kn) 3665 { 3666 struct proc *p = curproc; 3667 3668 kn->kn_ptr.p_proc = p; 3669 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3670 3671 knlist_add(p->p_klist, kn, 0); 3672 3673 return (0); 3674 } 3675 3676 static void 3677 filt_sigdetach(struct knote *kn) 3678 { 3679 struct proc *p = kn->kn_ptr.p_proc; 3680 3681 knlist_remove(p->p_klist, kn, 0); 3682 } 3683 3684 /* 3685 * signal knotes are shared with proc knotes, so we apply a mask to 3686 * the hint in order to differentiate them from process hints. This 3687 * could be avoided by using a signal-specific knote list, but probably 3688 * isn't worth the trouble. 3689 */ 3690 static int 3691 filt_signal(struct knote *kn, long hint) 3692 { 3693 3694 if (hint & NOTE_SIGNAL) { 3695 hint &= ~NOTE_SIGNAL; 3696 3697 if (kn->kn_id == hint) 3698 kn->kn_data++; 3699 } 3700 return (kn->kn_data != 0); 3701 } 3702 3703 struct sigacts * 3704 sigacts_alloc(void) 3705 { 3706 struct sigacts *ps; 3707 3708 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3709 refcount_init(&ps->ps_refcnt, 1); 3710 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3711 return (ps); 3712 } 3713 3714 void 3715 sigacts_free(struct sigacts *ps) 3716 { 3717 3718 if (refcount_release(&ps->ps_refcnt) == 0) 3719 return; 3720 mtx_destroy(&ps->ps_mtx); 3721 free(ps, M_SUBPROC); 3722 } 3723 3724 struct sigacts * 3725 sigacts_hold(struct sigacts *ps) 3726 { 3727 3728 refcount_acquire(&ps->ps_refcnt); 3729 return (ps); 3730 } 3731 3732 void 3733 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3734 { 3735 3736 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3737 mtx_lock(&src->ps_mtx); 3738 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3739 mtx_unlock(&src->ps_mtx); 3740 } 3741 3742 int 3743 sigacts_shared(struct sigacts *ps) 3744 { 3745 3746 return (ps->ps_refcnt > 1); 3747 } 3748