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