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