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(td, uap) 826 struct thread *td; 827 register struct sigaction_args *uap; 828 { 829 struct sigaction act, oact; 830 register struct sigaction *actp, *oactp; 831 int error; 832 833 actp = (uap->act != NULL) ? &act : NULL; 834 oactp = (uap->oact != NULL) ? &oact : NULL; 835 if (actp) { 836 error = copyin(uap->act, actp, sizeof(act)); 837 if (error) 838 return (error); 839 } 840 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 841 if (oactp && !error) 842 error = copyout(oactp, uap->oact, sizeof(oact)); 843 return (error); 844 } 845 846 #ifdef COMPAT_FREEBSD4 847 #ifndef _SYS_SYSPROTO_H_ 848 struct freebsd4_sigaction_args { 849 int sig; 850 struct sigaction *act; 851 struct sigaction *oact; 852 }; 853 #endif 854 int 855 freebsd4_sigaction(td, uap) 856 struct thread *td; 857 register struct freebsd4_sigaction_args *uap; 858 { 859 struct sigaction act, oact; 860 register struct sigaction *actp, *oactp; 861 int error; 862 863 864 actp = (uap->act != NULL) ? &act : NULL; 865 oactp = (uap->oact != NULL) ? &oact : NULL; 866 if (actp) { 867 error = copyin(uap->act, actp, sizeof(act)); 868 if (error) 869 return (error); 870 } 871 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 872 if (oactp && !error) 873 error = copyout(oactp, uap->oact, sizeof(oact)); 874 return (error); 875 } 876 #endif /* COMAPT_FREEBSD4 */ 877 878 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 879 #ifndef _SYS_SYSPROTO_H_ 880 struct osigaction_args { 881 int signum; 882 struct osigaction *nsa; 883 struct osigaction *osa; 884 }; 885 #endif 886 int 887 osigaction(td, uap) 888 struct thread *td; 889 register struct osigaction_args *uap; 890 { 891 struct osigaction sa; 892 struct sigaction nsa, osa; 893 register struct sigaction *nsap, *osap; 894 int error; 895 896 if (uap->signum <= 0 || uap->signum >= ONSIG) 897 return (EINVAL); 898 899 nsap = (uap->nsa != NULL) ? &nsa : NULL; 900 osap = (uap->osa != NULL) ? &osa : NULL; 901 902 if (nsap) { 903 error = copyin(uap->nsa, &sa, sizeof(sa)); 904 if (error) 905 return (error); 906 nsap->sa_handler = sa.sa_handler; 907 nsap->sa_flags = sa.sa_flags; 908 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 909 } 910 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 911 if (osap && !error) { 912 sa.sa_handler = osap->sa_handler; 913 sa.sa_flags = osap->sa_flags; 914 SIG2OSIG(osap->sa_mask, sa.sa_mask); 915 error = copyout(&sa, uap->osa, sizeof(sa)); 916 } 917 return (error); 918 } 919 920 #if !defined(__i386__) 921 /* Avoid replicating the same stub everywhere */ 922 int 923 osigreturn(td, uap) 924 struct thread *td; 925 struct osigreturn_args *uap; 926 { 927 928 return (nosys(td, (struct nosys_args *)uap)); 929 } 930 #endif 931 #endif /* COMPAT_43 */ 932 933 /* 934 * Initialize signal state for process 0; 935 * set to ignore signals that are ignored by default. 936 */ 937 void 938 siginit(p) 939 struct proc *p; 940 { 941 register int i; 942 struct sigacts *ps; 943 944 PROC_LOCK(p); 945 ps = p->p_sigacts; 946 mtx_lock(&ps->ps_mtx); 947 for (i = 1; i <= NSIG; i++) { 948 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 949 SIGADDSET(ps->ps_sigignore, i); 950 } 951 } 952 mtx_unlock(&ps->ps_mtx); 953 PROC_UNLOCK(p); 954 } 955 956 /* 957 * Reset specified signal to the default disposition. 958 */ 959 static void 960 sigdflt(struct sigacts *ps, int sig) 961 { 962 963 mtx_assert(&ps->ps_mtx, MA_OWNED); 964 SIGDELSET(ps->ps_sigcatch, sig); 965 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 966 SIGADDSET(ps->ps_sigignore, sig); 967 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 968 SIGDELSET(ps->ps_siginfo, sig); 969 } 970 971 /* 972 * Reset signals for an exec of the specified process. 973 */ 974 void 975 execsigs(struct proc *p) 976 { 977 sigset_t osigignore; 978 struct sigacts *ps; 979 int sig; 980 struct thread *td; 981 982 /* 983 * Reset caught signals. Held signals remain held 984 * through td_sigmask (unless they were caught, 985 * and are now ignored by default). 986 */ 987 PROC_LOCK_ASSERT(p, MA_OWNED); 988 td = FIRST_THREAD_IN_PROC(p); 989 ps = p->p_sigacts; 990 mtx_lock(&ps->ps_mtx); 991 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 992 sig = sig_ffs(&ps->ps_sigcatch); 993 sigdflt(ps, sig); 994 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 995 sigqueue_delete_proc(p, sig); 996 } 997 998 /* 999 * As CloudABI processes cannot modify signal handlers, fully 1000 * reset all signals to their default behavior. Do ignore 1001 * SIGPIPE, as it would otherwise be impossible to recover from 1002 * writes to broken pipes and sockets. 1003 */ 1004 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1005 osigignore = ps->ps_sigignore; 1006 while (SIGNOTEMPTY(osigignore)) { 1007 sig = sig_ffs(&osigignore); 1008 SIGDELSET(osigignore, sig); 1009 if (sig != SIGPIPE) 1010 sigdflt(ps, sig); 1011 } 1012 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1013 } 1014 1015 /* 1016 * Reset stack state to the user stack. 1017 * Clear set of signals caught on the signal stack. 1018 */ 1019 td->td_sigstk.ss_flags = SS_DISABLE; 1020 td->td_sigstk.ss_size = 0; 1021 td->td_sigstk.ss_sp = 0; 1022 td->td_pflags &= ~TDP_ALTSTACK; 1023 /* 1024 * Reset no zombies if child dies flag as Solaris does. 1025 */ 1026 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1027 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1028 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1029 mtx_unlock(&ps->ps_mtx); 1030 } 1031 1032 /* 1033 * kern_sigprocmask() 1034 * 1035 * Manipulate signal mask. 1036 */ 1037 int 1038 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1039 int flags) 1040 { 1041 sigset_t new_block, oset1; 1042 struct proc *p; 1043 int error; 1044 1045 p = td->td_proc; 1046 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1047 PROC_LOCK_ASSERT(p, MA_OWNED); 1048 else 1049 PROC_LOCK(p); 1050 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1051 ? MA_OWNED : MA_NOTOWNED); 1052 if (oset != NULL) 1053 *oset = td->td_sigmask; 1054 1055 error = 0; 1056 if (set != NULL) { 1057 switch (how) { 1058 case SIG_BLOCK: 1059 SIG_CANTMASK(*set); 1060 oset1 = td->td_sigmask; 1061 SIGSETOR(td->td_sigmask, *set); 1062 new_block = td->td_sigmask; 1063 SIGSETNAND(new_block, oset1); 1064 break; 1065 case SIG_UNBLOCK: 1066 SIGSETNAND(td->td_sigmask, *set); 1067 signotify(td); 1068 goto out; 1069 case SIG_SETMASK: 1070 SIG_CANTMASK(*set); 1071 oset1 = td->td_sigmask; 1072 if (flags & SIGPROCMASK_OLD) 1073 SIGSETLO(td->td_sigmask, *set); 1074 else 1075 td->td_sigmask = *set; 1076 new_block = td->td_sigmask; 1077 SIGSETNAND(new_block, oset1); 1078 signotify(td); 1079 break; 1080 default: 1081 error = EINVAL; 1082 goto out; 1083 } 1084 1085 /* 1086 * The new_block set contains signals that were not previously 1087 * blocked, but are blocked now. 1088 * 1089 * In case we block any signal that was not previously blocked 1090 * for td, and process has the signal pending, try to schedule 1091 * signal delivery to some thread that does not block the 1092 * signal, possibly waking it up. 1093 */ 1094 if (p->p_numthreads != 1) 1095 reschedule_signals(p, new_block, flags); 1096 } 1097 1098 out: 1099 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1100 PROC_UNLOCK(p); 1101 return (error); 1102 } 1103 1104 #ifndef _SYS_SYSPROTO_H_ 1105 struct sigprocmask_args { 1106 int how; 1107 const sigset_t *set; 1108 sigset_t *oset; 1109 }; 1110 #endif 1111 int 1112 sys_sigprocmask(td, uap) 1113 register struct thread *td; 1114 struct sigprocmask_args *uap; 1115 { 1116 sigset_t set, oset; 1117 sigset_t *setp, *osetp; 1118 int error; 1119 1120 setp = (uap->set != NULL) ? &set : NULL; 1121 osetp = (uap->oset != NULL) ? &oset : NULL; 1122 if (setp) { 1123 error = copyin(uap->set, setp, sizeof(set)); 1124 if (error) 1125 return (error); 1126 } 1127 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1128 if (osetp && !error) { 1129 error = copyout(osetp, uap->oset, sizeof(oset)); 1130 } 1131 return (error); 1132 } 1133 1134 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1135 #ifndef _SYS_SYSPROTO_H_ 1136 struct osigprocmask_args { 1137 int how; 1138 osigset_t mask; 1139 }; 1140 #endif 1141 int 1142 osigprocmask(td, uap) 1143 register struct thread *td; 1144 struct osigprocmask_args *uap; 1145 { 1146 sigset_t set, oset; 1147 int error; 1148 1149 OSIG2SIG(uap->mask, set); 1150 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1151 SIG2OSIG(oset, td->td_retval[0]); 1152 return (error); 1153 } 1154 #endif /* COMPAT_43 */ 1155 1156 int 1157 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1158 { 1159 ksiginfo_t ksi; 1160 sigset_t set; 1161 int error; 1162 1163 error = copyin(uap->set, &set, sizeof(set)); 1164 if (error) { 1165 td->td_retval[0] = error; 1166 return (0); 1167 } 1168 1169 error = kern_sigtimedwait(td, set, &ksi, NULL); 1170 if (error) { 1171 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1172 error = ERESTART; 1173 if (error == ERESTART) 1174 return (error); 1175 td->td_retval[0] = error; 1176 return (0); 1177 } 1178 1179 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1180 td->td_retval[0] = error; 1181 return (0); 1182 } 1183 1184 int 1185 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1186 { 1187 struct timespec ts; 1188 struct timespec *timeout; 1189 sigset_t set; 1190 ksiginfo_t ksi; 1191 int error; 1192 1193 if (uap->timeout) { 1194 error = copyin(uap->timeout, &ts, sizeof(ts)); 1195 if (error) 1196 return (error); 1197 1198 timeout = &ts; 1199 } else 1200 timeout = NULL; 1201 1202 error = copyin(uap->set, &set, sizeof(set)); 1203 if (error) 1204 return (error); 1205 1206 error = kern_sigtimedwait(td, set, &ksi, timeout); 1207 if (error) 1208 return (error); 1209 1210 if (uap->info) 1211 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1212 1213 if (error == 0) 1214 td->td_retval[0] = ksi.ksi_signo; 1215 return (error); 1216 } 1217 1218 int 1219 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1220 { 1221 ksiginfo_t ksi; 1222 sigset_t set; 1223 int error; 1224 1225 error = copyin(uap->set, &set, sizeof(set)); 1226 if (error) 1227 return (error); 1228 1229 error = kern_sigtimedwait(td, set, &ksi, NULL); 1230 if (error) 1231 return (error); 1232 1233 if (uap->info) 1234 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1235 1236 if (error == 0) 1237 td->td_retval[0] = ksi.ksi_signo; 1238 return (error); 1239 } 1240 1241 int 1242 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1243 struct timespec *timeout) 1244 { 1245 struct sigacts *ps; 1246 sigset_t saved_mask, new_block; 1247 struct proc *p; 1248 int error, sig, timo, timevalid = 0; 1249 struct timespec rts, ets, ts; 1250 struct timeval tv; 1251 1252 p = td->td_proc; 1253 error = 0; 1254 ets.tv_sec = 0; 1255 ets.tv_nsec = 0; 1256 1257 if (timeout != NULL) { 1258 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1259 timevalid = 1; 1260 getnanouptime(&rts); 1261 ets = rts; 1262 timespecadd(&ets, timeout); 1263 } 1264 } 1265 ksiginfo_init(ksi); 1266 /* Some signals can not be waited for. */ 1267 SIG_CANTMASK(waitset); 1268 ps = p->p_sigacts; 1269 PROC_LOCK(p); 1270 saved_mask = td->td_sigmask; 1271 SIGSETNAND(td->td_sigmask, waitset); 1272 for (;;) { 1273 mtx_lock(&ps->ps_mtx); 1274 sig = cursig(td); 1275 mtx_unlock(&ps->ps_mtx); 1276 KASSERT(sig >= 0, ("sig %d", sig)); 1277 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1278 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1279 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1280 error = 0; 1281 break; 1282 } 1283 } 1284 1285 if (error != 0) 1286 break; 1287 1288 /* 1289 * POSIX says this must be checked after looking for pending 1290 * signals. 1291 */ 1292 if (timeout != NULL) { 1293 if (!timevalid) { 1294 error = EINVAL; 1295 break; 1296 } 1297 getnanouptime(&rts); 1298 if (timespeccmp(&rts, &ets, >=)) { 1299 error = EAGAIN; 1300 break; 1301 } 1302 ts = ets; 1303 timespecsub(&ts, &rts); 1304 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1305 timo = tvtohz(&tv); 1306 } else { 1307 timo = 0; 1308 } 1309 1310 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1311 1312 if (timeout != NULL) { 1313 if (error == ERESTART) { 1314 /* Timeout can not be restarted. */ 1315 error = EINTR; 1316 } else if (error == EAGAIN) { 1317 /* We will calculate timeout by ourself. */ 1318 error = 0; 1319 } 1320 } 1321 } 1322 1323 new_block = saved_mask; 1324 SIGSETNAND(new_block, td->td_sigmask); 1325 td->td_sigmask = saved_mask; 1326 /* 1327 * Fewer signals can be delivered to us, reschedule signal 1328 * notification. 1329 */ 1330 if (p->p_numthreads != 1) 1331 reschedule_signals(p, new_block, 0); 1332 1333 if (error == 0) { 1334 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1335 1336 if (ksi->ksi_code == SI_TIMER) 1337 itimer_accept(p, ksi->ksi_timerid, ksi); 1338 1339 #ifdef KTRACE 1340 if (KTRPOINT(td, KTR_PSIG)) { 1341 sig_t action; 1342 1343 mtx_lock(&ps->ps_mtx); 1344 action = ps->ps_sigact[_SIG_IDX(sig)]; 1345 mtx_unlock(&ps->ps_mtx); 1346 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1347 } 1348 #endif 1349 if (sig == SIGKILL) 1350 sigexit(td, sig); 1351 } 1352 PROC_UNLOCK(p); 1353 return (error); 1354 } 1355 1356 #ifndef _SYS_SYSPROTO_H_ 1357 struct sigpending_args { 1358 sigset_t *set; 1359 }; 1360 #endif 1361 int 1362 sys_sigpending(td, uap) 1363 struct thread *td; 1364 struct sigpending_args *uap; 1365 { 1366 struct proc *p = td->td_proc; 1367 sigset_t pending; 1368 1369 PROC_LOCK(p); 1370 pending = p->p_sigqueue.sq_signals; 1371 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1372 PROC_UNLOCK(p); 1373 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1374 } 1375 1376 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1377 #ifndef _SYS_SYSPROTO_H_ 1378 struct osigpending_args { 1379 int dummy; 1380 }; 1381 #endif 1382 int 1383 osigpending(td, uap) 1384 struct thread *td; 1385 struct osigpending_args *uap; 1386 { 1387 struct proc *p = td->td_proc; 1388 sigset_t pending; 1389 1390 PROC_LOCK(p); 1391 pending = p->p_sigqueue.sq_signals; 1392 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1393 PROC_UNLOCK(p); 1394 SIG2OSIG(pending, td->td_retval[0]); 1395 return (0); 1396 } 1397 #endif /* COMPAT_43 */ 1398 1399 #if defined(COMPAT_43) 1400 /* 1401 * Generalized interface signal handler, 4.3-compatible. 1402 */ 1403 #ifndef _SYS_SYSPROTO_H_ 1404 struct osigvec_args { 1405 int signum; 1406 struct sigvec *nsv; 1407 struct sigvec *osv; 1408 }; 1409 #endif 1410 /* ARGSUSED */ 1411 int 1412 osigvec(td, uap) 1413 struct thread *td; 1414 register struct osigvec_args *uap; 1415 { 1416 struct sigvec vec; 1417 struct sigaction nsa, osa; 1418 register struct sigaction *nsap, *osap; 1419 int error; 1420 1421 if (uap->signum <= 0 || uap->signum >= ONSIG) 1422 return (EINVAL); 1423 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1424 osap = (uap->osv != NULL) ? &osa : NULL; 1425 if (nsap) { 1426 error = copyin(uap->nsv, &vec, sizeof(vec)); 1427 if (error) 1428 return (error); 1429 nsap->sa_handler = vec.sv_handler; 1430 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1431 nsap->sa_flags = vec.sv_flags; 1432 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1433 } 1434 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1435 if (osap && !error) { 1436 vec.sv_handler = osap->sa_handler; 1437 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1438 vec.sv_flags = osap->sa_flags; 1439 vec.sv_flags &= ~SA_NOCLDWAIT; 1440 vec.sv_flags ^= SA_RESTART; 1441 error = copyout(&vec, uap->osv, sizeof(vec)); 1442 } 1443 return (error); 1444 } 1445 1446 #ifndef _SYS_SYSPROTO_H_ 1447 struct osigblock_args { 1448 int mask; 1449 }; 1450 #endif 1451 int 1452 osigblock(td, uap) 1453 register struct thread *td; 1454 struct osigblock_args *uap; 1455 { 1456 sigset_t set, oset; 1457 1458 OSIG2SIG(uap->mask, set); 1459 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1460 SIG2OSIG(oset, td->td_retval[0]); 1461 return (0); 1462 } 1463 1464 #ifndef _SYS_SYSPROTO_H_ 1465 struct osigsetmask_args { 1466 int mask; 1467 }; 1468 #endif 1469 int 1470 osigsetmask(td, uap) 1471 struct thread *td; 1472 struct osigsetmask_args *uap; 1473 { 1474 sigset_t set, oset; 1475 1476 OSIG2SIG(uap->mask, set); 1477 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1478 SIG2OSIG(oset, td->td_retval[0]); 1479 return (0); 1480 } 1481 #endif /* COMPAT_43 */ 1482 1483 /* 1484 * Suspend calling thread until signal, providing mask to be set in the 1485 * meantime. 1486 */ 1487 #ifndef _SYS_SYSPROTO_H_ 1488 struct sigsuspend_args { 1489 const sigset_t *sigmask; 1490 }; 1491 #endif 1492 /* ARGSUSED */ 1493 int 1494 sys_sigsuspend(td, uap) 1495 struct thread *td; 1496 struct sigsuspend_args *uap; 1497 { 1498 sigset_t mask; 1499 int error; 1500 1501 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1502 if (error) 1503 return (error); 1504 return (kern_sigsuspend(td, mask)); 1505 } 1506 1507 int 1508 kern_sigsuspend(struct thread *td, sigset_t mask) 1509 { 1510 struct proc *p = td->td_proc; 1511 int has_sig, sig; 1512 1513 /* 1514 * When returning from sigsuspend, we want 1515 * the old mask to be restored after the 1516 * signal handler has finished. Thus, we 1517 * save it here and mark the sigacts structure 1518 * to indicate this. 1519 */ 1520 PROC_LOCK(p); 1521 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1522 SIGPROCMASK_PROC_LOCKED); 1523 td->td_pflags |= TDP_OLDMASK; 1524 1525 /* 1526 * Process signals now. Otherwise, we can get spurious wakeup 1527 * due to signal entered process queue, but delivered to other 1528 * thread. But sigsuspend should return only on signal 1529 * delivery. 1530 */ 1531 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1532 for (has_sig = 0; !has_sig;) { 1533 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1534 0) == 0) 1535 /* void */; 1536 thread_suspend_check(0); 1537 mtx_lock(&p->p_sigacts->ps_mtx); 1538 while ((sig = cursig(td)) != 0) { 1539 KASSERT(sig >= 0, ("sig %d", sig)); 1540 has_sig += postsig(sig); 1541 } 1542 mtx_unlock(&p->p_sigacts->ps_mtx); 1543 } 1544 PROC_UNLOCK(p); 1545 td->td_errno = EINTR; 1546 td->td_pflags |= TDP_NERRNO; 1547 return (EJUSTRETURN); 1548 } 1549 1550 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1551 /* 1552 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1553 * convention: libc stub passes mask, not pointer, to save a copyin. 1554 */ 1555 #ifndef _SYS_SYSPROTO_H_ 1556 struct osigsuspend_args { 1557 osigset_t mask; 1558 }; 1559 #endif 1560 /* ARGSUSED */ 1561 int 1562 osigsuspend(td, uap) 1563 struct thread *td; 1564 struct osigsuspend_args *uap; 1565 { 1566 sigset_t mask; 1567 1568 OSIG2SIG(uap->mask, mask); 1569 return (kern_sigsuspend(td, mask)); 1570 } 1571 #endif /* COMPAT_43 */ 1572 1573 #if defined(COMPAT_43) 1574 #ifndef _SYS_SYSPROTO_H_ 1575 struct osigstack_args { 1576 struct sigstack *nss; 1577 struct sigstack *oss; 1578 }; 1579 #endif 1580 /* ARGSUSED */ 1581 int 1582 osigstack(td, uap) 1583 struct thread *td; 1584 register struct osigstack_args *uap; 1585 { 1586 struct sigstack nss, oss; 1587 int error = 0; 1588 1589 if (uap->nss != NULL) { 1590 error = copyin(uap->nss, &nss, sizeof(nss)); 1591 if (error) 1592 return (error); 1593 } 1594 oss.ss_sp = td->td_sigstk.ss_sp; 1595 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1596 if (uap->nss != NULL) { 1597 td->td_sigstk.ss_sp = nss.ss_sp; 1598 td->td_sigstk.ss_size = 0; 1599 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1600 td->td_pflags |= TDP_ALTSTACK; 1601 } 1602 if (uap->oss != NULL) 1603 error = copyout(&oss, uap->oss, sizeof(oss)); 1604 1605 return (error); 1606 } 1607 #endif /* COMPAT_43 */ 1608 1609 #ifndef _SYS_SYSPROTO_H_ 1610 struct sigaltstack_args { 1611 stack_t *ss; 1612 stack_t *oss; 1613 }; 1614 #endif 1615 /* ARGSUSED */ 1616 int 1617 sys_sigaltstack(td, uap) 1618 struct thread *td; 1619 register struct sigaltstack_args *uap; 1620 { 1621 stack_t ss, oss; 1622 int error; 1623 1624 if (uap->ss != NULL) { 1625 error = copyin(uap->ss, &ss, sizeof(ss)); 1626 if (error) 1627 return (error); 1628 } 1629 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1630 (uap->oss != NULL) ? &oss : NULL); 1631 if (error) 1632 return (error); 1633 if (uap->oss != NULL) 1634 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1635 return (error); 1636 } 1637 1638 int 1639 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1640 { 1641 struct proc *p = td->td_proc; 1642 int oonstack; 1643 1644 oonstack = sigonstack(cpu_getstack(td)); 1645 1646 if (oss != NULL) { 1647 *oss = td->td_sigstk; 1648 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1649 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1650 } 1651 1652 if (ss != NULL) { 1653 if (oonstack) 1654 return (EPERM); 1655 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1656 return (EINVAL); 1657 if (!(ss->ss_flags & SS_DISABLE)) { 1658 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1659 return (ENOMEM); 1660 1661 td->td_sigstk = *ss; 1662 td->td_pflags |= TDP_ALTSTACK; 1663 } else { 1664 td->td_pflags &= ~TDP_ALTSTACK; 1665 } 1666 } 1667 return (0); 1668 } 1669 1670 /* 1671 * Common code for kill process group/broadcast kill. 1672 * cp is calling process. 1673 */ 1674 static int 1675 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1676 { 1677 struct proc *p; 1678 struct pgrp *pgrp; 1679 int err; 1680 int ret; 1681 1682 ret = ESRCH; 1683 if (all) { 1684 /* 1685 * broadcast 1686 */ 1687 sx_slock(&allproc_lock); 1688 FOREACH_PROC_IN_SYSTEM(p) { 1689 PROC_LOCK(p); 1690 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1691 p == td->td_proc || p->p_state == PRS_NEW) { 1692 PROC_UNLOCK(p); 1693 continue; 1694 } 1695 err = p_cansignal(td, p, sig); 1696 if (err == 0) { 1697 if (sig) 1698 pksignal(p, sig, ksi); 1699 ret = err; 1700 } 1701 else if (ret == ESRCH) 1702 ret = err; 1703 PROC_UNLOCK(p); 1704 } 1705 sx_sunlock(&allproc_lock); 1706 } else { 1707 sx_slock(&proctree_lock); 1708 if (pgid == 0) { 1709 /* 1710 * zero pgid means send to my process group. 1711 */ 1712 pgrp = td->td_proc->p_pgrp; 1713 PGRP_LOCK(pgrp); 1714 } else { 1715 pgrp = pgfind(pgid); 1716 if (pgrp == NULL) { 1717 sx_sunlock(&proctree_lock); 1718 return (ESRCH); 1719 } 1720 } 1721 sx_sunlock(&proctree_lock); 1722 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1723 PROC_LOCK(p); 1724 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1725 p->p_state == PRS_NEW) { 1726 PROC_UNLOCK(p); 1727 continue; 1728 } 1729 err = p_cansignal(td, p, sig); 1730 if (err == 0) { 1731 if (sig) 1732 pksignal(p, sig, ksi); 1733 ret = err; 1734 } 1735 else if (ret == ESRCH) 1736 ret = err; 1737 PROC_UNLOCK(p); 1738 } 1739 PGRP_UNLOCK(pgrp); 1740 } 1741 return (ret); 1742 } 1743 1744 #ifndef _SYS_SYSPROTO_H_ 1745 struct kill_args { 1746 int pid; 1747 int signum; 1748 }; 1749 #endif 1750 /* ARGSUSED */ 1751 int 1752 sys_kill(struct thread *td, struct kill_args *uap) 1753 { 1754 ksiginfo_t ksi; 1755 struct proc *p; 1756 int error; 1757 1758 /* 1759 * A process in capability mode can send signals only to himself. 1760 * The main rationale behind this is that abort(3) is implemented as 1761 * kill(getpid(), SIGABRT). 1762 */ 1763 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1764 return (ECAPMODE); 1765 1766 AUDIT_ARG_SIGNUM(uap->signum); 1767 AUDIT_ARG_PID(uap->pid); 1768 if ((u_int)uap->signum > _SIG_MAXSIG) 1769 return (EINVAL); 1770 1771 ksiginfo_init(&ksi); 1772 ksi.ksi_signo = uap->signum; 1773 ksi.ksi_code = SI_USER; 1774 ksi.ksi_pid = td->td_proc->p_pid; 1775 ksi.ksi_uid = td->td_ucred->cr_ruid; 1776 1777 if (uap->pid > 0) { 1778 /* kill single process */ 1779 if ((p = pfind(uap->pid)) == NULL) { 1780 if ((p = zpfind(uap->pid)) == NULL) 1781 return (ESRCH); 1782 } 1783 AUDIT_ARG_PROCESS(p); 1784 error = p_cansignal(td, p, uap->signum); 1785 if (error == 0 && uap->signum) 1786 pksignal(p, uap->signum, &ksi); 1787 PROC_UNLOCK(p); 1788 return (error); 1789 } 1790 switch (uap->pid) { 1791 case -1: /* broadcast signal */ 1792 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1793 case 0: /* signal own process group */ 1794 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1795 default: /* negative explicit process group */ 1796 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1797 } 1798 /* NOTREACHED */ 1799 } 1800 1801 int 1802 sys_pdkill(td, uap) 1803 struct thread *td; 1804 struct pdkill_args *uap; 1805 { 1806 struct proc *p; 1807 cap_rights_t rights; 1808 int error; 1809 1810 AUDIT_ARG_SIGNUM(uap->signum); 1811 AUDIT_ARG_FD(uap->fd); 1812 if ((u_int)uap->signum > _SIG_MAXSIG) 1813 return (EINVAL); 1814 1815 error = procdesc_find(td, uap->fd, 1816 cap_rights_init(&rights, CAP_PDKILL), &p); 1817 if (error) 1818 return (error); 1819 AUDIT_ARG_PROCESS(p); 1820 error = p_cansignal(td, p, uap->signum); 1821 if (error == 0 && uap->signum) 1822 kern_psignal(p, uap->signum); 1823 PROC_UNLOCK(p); 1824 return (error); 1825 } 1826 1827 #if defined(COMPAT_43) 1828 #ifndef _SYS_SYSPROTO_H_ 1829 struct okillpg_args { 1830 int pgid; 1831 int signum; 1832 }; 1833 #endif 1834 /* ARGSUSED */ 1835 int 1836 okillpg(struct thread *td, struct okillpg_args *uap) 1837 { 1838 ksiginfo_t ksi; 1839 1840 AUDIT_ARG_SIGNUM(uap->signum); 1841 AUDIT_ARG_PID(uap->pgid); 1842 if ((u_int)uap->signum > _SIG_MAXSIG) 1843 return (EINVAL); 1844 1845 ksiginfo_init(&ksi); 1846 ksi.ksi_signo = uap->signum; 1847 ksi.ksi_code = SI_USER; 1848 ksi.ksi_pid = td->td_proc->p_pid; 1849 ksi.ksi_uid = td->td_ucred->cr_ruid; 1850 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1851 } 1852 #endif /* COMPAT_43 */ 1853 1854 #ifndef _SYS_SYSPROTO_H_ 1855 struct sigqueue_args { 1856 pid_t pid; 1857 int signum; 1858 /* union sigval */ void *value; 1859 }; 1860 #endif 1861 int 1862 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1863 { 1864 ksiginfo_t ksi; 1865 struct proc *p; 1866 int error; 1867 1868 if ((u_int)uap->signum > _SIG_MAXSIG) 1869 return (EINVAL); 1870 1871 /* 1872 * Specification says sigqueue can only send signal to 1873 * single process. 1874 */ 1875 if (uap->pid <= 0) 1876 return (EINVAL); 1877 1878 if ((p = pfind(uap->pid)) == NULL) { 1879 if ((p = zpfind(uap->pid)) == NULL) 1880 return (ESRCH); 1881 } 1882 error = p_cansignal(td, p, uap->signum); 1883 if (error == 0 && uap->signum != 0) { 1884 ksiginfo_init(&ksi); 1885 ksi.ksi_flags = KSI_SIGQ; 1886 ksi.ksi_signo = uap->signum; 1887 ksi.ksi_code = SI_QUEUE; 1888 ksi.ksi_pid = td->td_proc->p_pid; 1889 ksi.ksi_uid = td->td_ucred->cr_ruid; 1890 ksi.ksi_value.sival_ptr = uap->value; 1891 error = pksignal(p, ksi.ksi_signo, &ksi); 1892 } 1893 PROC_UNLOCK(p); 1894 return (error); 1895 } 1896 1897 /* 1898 * Send a signal to a process group. 1899 */ 1900 void 1901 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1902 { 1903 struct pgrp *pgrp; 1904 1905 if (pgid != 0) { 1906 sx_slock(&proctree_lock); 1907 pgrp = pgfind(pgid); 1908 sx_sunlock(&proctree_lock); 1909 if (pgrp != NULL) { 1910 pgsignal(pgrp, sig, 0, ksi); 1911 PGRP_UNLOCK(pgrp); 1912 } 1913 } 1914 } 1915 1916 /* 1917 * Send a signal to a process group. If checktty is 1, 1918 * limit to members which have a controlling terminal. 1919 */ 1920 void 1921 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1922 { 1923 struct proc *p; 1924 1925 if (pgrp) { 1926 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1927 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1928 PROC_LOCK(p); 1929 if (p->p_state == PRS_NORMAL && 1930 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1931 pksignal(p, sig, ksi); 1932 PROC_UNLOCK(p); 1933 } 1934 } 1935 } 1936 1937 1938 /* 1939 * Recalculate the signal mask and reset the signal disposition after 1940 * usermode frame for delivery is formed. Should be called after 1941 * mach-specific routine, because sysent->sv_sendsig() needs correct 1942 * ps_siginfo and signal mask. 1943 */ 1944 static void 1945 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1946 { 1947 sigset_t mask; 1948 1949 mtx_assert(&ps->ps_mtx, MA_OWNED); 1950 td->td_ru.ru_nsignals++; 1951 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1952 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1953 SIGADDSET(mask, sig); 1954 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1955 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1956 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1957 sigdflt(ps, sig); 1958 } 1959 1960 1961 /* 1962 * Send a signal caused by a trap to the current thread. If it will be 1963 * caught immediately, deliver it with correct code. Otherwise, post it 1964 * normally. 1965 */ 1966 void 1967 trapsignal(struct thread *td, ksiginfo_t *ksi) 1968 { 1969 struct sigacts *ps; 1970 struct proc *p; 1971 int sig; 1972 int code; 1973 1974 p = td->td_proc; 1975 sig = ksi->ksi_signo; 1976 code = ksi->ksi_code; 1977 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1978 1979 PROC_LOCK(p); 1980 ps = p->p_sigacts; 1981 mtx_lock(&ps->ps_mtx); 1982 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1983 !SIGISMEMBER(td->td_sigmask, sig)) { 1984 #ifdef KTRACE 1985 if (KTRPOINT(curthread, KTR_PSIG)) 1986 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1987 &td->td_sigmask, code); 1988 #endif 1989 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1990 ksi, &td->td_sigmask); 1991 postsig_done(sig, td, ps); 1992 mtx_unlock(&ps->ps_mtx); 1993 } else { 1994 /* 1995 * Avoid a possible infinite loop if the thread 1996 * masking the signal or process is ignoring the 1997 * signal. 1998 */ 1999 if (kern_forcesigexit && 2000 (SIGISMEMBER(td->td_sigmask, sig) || 2001 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2002 SIGDELSET(td->td_sigmask, sig); 2003 SIGDELSET(ps->ps_sigcatch, sig); 2004 SIGDELSET(ps->ps_sigignore, sig); 2005 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2006 } 2007 mtx_unlock(&ps->ps_mtx); 2008 p->p_code = code; /* XXX for core dump/debugger */ 2009 p->p_sig = sig; /* XXX to verify code */ 2010 tdsendsignal(p, td, sig, ksi); 2011 } 2012 PROC_UNLOCK(p); 2013 } 2014 2015 static struct thread * 2016 sigtd(struct proc *p, int sig, int prop) 2017 { 2018 struct thread *td, *signal_td; 2019 2020 PROC_LOCK_ASSERT(p, MA_OWNED); 2021 2022 /* 2023 * Check if current thread can handle the signal without 2024 * switching context to another thread. 2025 */ 2026 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2027 return (curthread); 2028 signal_td = NULL; 2029 FOREACH_THREAD_IN_PROC(p, td) { 2030 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2031 signal_td = td; 2032 break; 2033 } 2034 } 2035 if (signal_td == NULL) 2036 signal_td = FIRST_THREAD_IN_PROC(p); 2037 return (signal_td); 2038 } 2039 2040 /* 2041 * Send the signal to the process. If the signal has an action, the action 2042 * is usually performed by the target process rather than the caller; we add 2043 * the signal to the set of pending signals for the process. 2044 * 2045 * Exceptions: 2046 * o When a stop signal is sent to a sleeping process that takes the 2047 * default action, the process is stopped without awakening it. 2048 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2049 * regardless of the signal action (eg, blocked or ignored). 2050 * 2051 * Other ignored signals are discarded immediately. 2052 * 2053 * NB: This function may be entered from the debugger via the "kill" DDB 2054 * command. There is little that can be done to mitigate the possibly messy 2055 * side effects of this unwise possibility. 2056 */ 2057 void 2058 kern_psignal(struct proc *p, int sig) 2059 { 2060 ksiginfo_t ksi; 2061 2062 ksiginfo_init(&ksi); 2063 ksi.ksi_signo = sig; 2064 ksi.ksi_code = SI_KERNEL; 2065 (void) tdsendsignal(p, NULL, sig, &ksi); 2066 } 2067 2068 int 2069 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2070 { 2071 2072 return (tdsendsignal(p, NULL, sig, ksi)); 2073 } 2074 2075 /* Utility function for finding a thread to send signal event to. */ 2076 int 2077 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2078 { 2079 struct thread *td; 2080 2081 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2082 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2083 if (td == NULL) 2084 return (ESRCH); 2085 *ttd = td; 2086 } else { 2087 *ttd = NULL; 2088 PROC_LOCK(p); 2089 } 2090 return (0); 2091 } 2092 2093 void 2094 tdsignal(struct thread *td, int sig) 2095 { 2096 ksiginfo_t ksi; 2097 2098 ksiginfo_init(&ksi); 2099 ksi.ksi_signo = sig; 2100 ksi.ksi_code = SI_KERNEL; 2101 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2102 } 2103 2104 void 2105 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2106 { 2107 2108 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2109 } 2110 2111 int 2112 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2113 { 2114 sig_t action; 2115 sigqueue_t *sigqueue; 2116 int prop; 2117 struct sigacts *ps; 2118 int intrval; 2119 int ret = 0; 2120 int wakeup_swapper; 2121 2122 MPASS(td == NULL || p == td->td_proc); 2123 PROC_LOCK_ASSERT(p, MA_OWNED); 2124 2125 if (!_SIG_VALID(sig)) 2126 panic("%s(): invalid signal %d", __func__, sig); 2127 2128 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2129 2130 /* 2131 * IEEE Std 1003.1-2001: return success when killing a zombie. 2132 */ 2133 if (p->p_state == PRS_ZOMBIE) { 2134 if (ksi && (ksi->ksi_flags & KSI_INS)) 2135 ksiginfo_tryfree(ksi); 2136 return (ret); 2137 } 2138 2139 ps = p->p_sigacts; 2140 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2141 prop = sigprop(sig); 2142 2143 if (td == NULL) { 2144 td = sigtd(p, sig, prop); 2145 sigqueue = &p->p_sigqueue; 2146 } else 2147 sigqueue = &td->td_sigqueue; 2148 2149 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2150 2151 /* 2152 * If the signal is being ignored, 2153 * then we forget about it immediately. 2154 * (Note: we don't set SIGCONT in ps_sigignore, 2155 * and if it is set to SIG_IGN, 2156 * action will be SIG_DFL here.) 2157 */ 2158 mtx_lock(&ps->ps_mtx); 2159 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2160 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2161 2162 mtx_unlock(&ps->ps_mtx); 2163 if (ksi && (ksi->ksi_flags & KSI_INS)) 2164 ksiginfo_tryfree(ksi); 2165 return (ret); 2166 } 2167 if (SIGISMEMBER(td->td_sigmask, sig)) 2168 action = SIG_HOLD; 2169 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2170 action = SIG_CATCH; 2171 else 2172 action = SIG_DFL; 2173 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2174 intrval = EINTR; 2175 else 2176 intrval = ERESTART; 2177 mtx_unlock(&ps->ps_mtx); 2178 2179 if (prop & SIGPROP_CONT) 2180 sigqueue_delete_stopmask_proc(p); 2181 else if (prop & SIGPROP_STOP) { 2182 /* 2183 * If sending a tty stop signal to a member of an orphaned 2184 * process group, discard the signal here if the action 2185 * is default; don't stop the process below if sleeping, 2186 * and don't clear any pending SIGCONT. 2187 */ 2188 if ((prop & SIGPROP_TTYSTOP) && 2189 (p->p_pgrp->pg_jobc == 0) && 2190 (action == SIG_DFL)) { 2191 if (ksi && (ksi->ksi_flags & KSI_INS)) 2192 ksiginfo_tryfree(ksi); 2193 return (ret); 2194 } 2195 sigqueue_delete_proc(p, SIGCONT); 2196 if (p->p_flag & P_CONTINUED) { 2197 p->p_flag &= ~P_CONTINUED; 2198 PROC_LOCK(p->p_pptr); 2199 sigqueue_take(p->p_ksi); 2200 PROC_UNLOCK(p->p_pptr); 2201 } 2202 } 2203 2204 ret = sigqueue_add(sigqueue, sig, ksi); 2205 if (ret != 0) 2206 return (ret); 2207 signotify(td); 2208 /* 2209 * Defer further processing for signals which are held, 2210 * except that stopped processes must be continued by SIGCONT. 2211 */ 2212 if (action == SIG_HOLD && 2213 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2214 return (ret); 2215 /* 2216 * SIGKILL: Remove procfs STOPEVENTs and ptrace events. 2217 */ 2218 if (sig == SIGKILL) { 2219 p->p_ptevents = 0; 2220 /* from procfs_ioctl.c: PIOCBIC */ 2221 p->p_stops = 0; 2222 /* from procfs_ioctl.c: PIOCCONT */ 2223 p->p_step = 0; 2224 wakeup(&p->p_step); 2225 } 2226 /* 2227 * Some signals have a process-wide effect and a per-thread 2228 * component. Most processing occurs when the process next 2229 * tries to cross the user boundary, however there are some 2230 * times when processing needs to be done immediately, such as 2231 * waking up threads so that they can cross the user boundary. 2232 * We try to do the per-process part here. 2233 */ 2234 if (P_SHOULDSTOP(p)) { 2235 KASSERT(!(p->p_flag & P_WEXIT), 2236 ("signal to stopped but exiting process")); 2237 if (sig == SIGKILL) { 2238 /* 2239 * If traced process is already stopped, 2240 * then no further action is necessary. 2241 */ 2242 if (p->p_flag & P_TRACED) 2243 goto out; 2244 /* 2245 * SIGKILL sets process running. 2246 * It will die elsewhere. 2247 * All threads must be restarted. 2248 */ 2249 p->p_flag &= ~P_STOPPED_SIG; 2250 goto runfast; 2251 } 2252 2253 if (prop & SIGPROP_CONT) { 2254 /* 2255 * If traced process is already stopped, 2256 * then no further action is necessary. 2257 */ 2258 if (p->p_flag & P_TRACED) 2259 goto out; 2260 /* 2261 * If SIGCONT is default (or ignored), we continue the 2262 * process but don't leave the signal in sigqueue as 2263 * it has no further action. If SIGCONT is held, we 2264 * continue the process and leave the signal in 2265 * sigqueue. If the process catches SIGCONT, let it 2266 * handle the signal itself. If it isn't waiting on 2267 * an event, it goes back to run state. 2268 * Otherwise, process goes back to sleep state. 2269 */ 2270 p->p_flag &= ~P_STOPPED_SIG; 2271 PROC_SLOCK(p); 2272 if (p->p_numthreads == p->p_suspcount) { 2273 PROC_SUNLOCK(p); 2274 p->p_flag |= P_CONTINUED; 2275 p->p_xsig = SIGCONT; 2276 PROC_LOCK(p->p_pptr); 2277 childproc_continued(p); 2278 PROC_UNLOCK(p->p_pptr); 2279 PROC_SLOCK(p); 2280 } 2281 if (action == SIG_DFL) { 2282 thread_unsuspend(p); 2283 PROC_SUNLOCK(p); 2284 sigqueue_delete(sigqueue, sig); 2285 goto out; 2286 } 2287 if (action == SIG_CATCH) { 2288 /* 2289 * The process wants to catch it so it needs 2290 * to run at least one thread, but which one? 2291 */ 2292 PROC_SUNLOCK(p); 2293 goto runfast; 2294 } 2295 /* 2296 * The signal is not ignored or caught. 2297 */ 2298 thread_unsuspend(p); 2299 PROC_SUNLOCK(p); 2300 goto out; 2301 } 2302 2303 if (prop & SIGPROP_STOP) { 2304 /* 2305 * If traced process is already stopped, 2306 * then no further action is necessary. 2307 */ 2308 if (p->p_flag & P_TRACED) 2309 goto out; 2310 /* 2311 * Already stopped, don't need to stop again 2312 * (If we did the shell could get confused). 2313 * Just make sure the signal STOP bit set. 2314 */ 2315 p->p_flag |= P_STOPPED_SIG; 2316 sigqueue_delete(sigqueue, sig); 2317 goto out; 2318 } 2319 2320 /* 2321 * All other kinds of signals: 2322 * If a thread is sleeping interruptibly, simulate a 2323 * wakeup so that when it is continued it will be made 2324 * runnable and can look at the signal. However, don't make 2325 * the PROCESS runnable, leave it stopped. 2326 * It may run a bit until it hits a thread_suspend_check(). 2327 */ 2328 wakeup_swapper = 0; 2329 PROC_SLOCK(p); 2330 thread_lock(td); 2331 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2332 wakeup_swapper = sleepq_abort(td, intrval); 2333 thread_unlock(td); 2334 PROC_SUNLOCK(p); 2335 if (wakeup_swapper) 2336 kick_proc0(); 2337 goto out; 2338 /* 2339 * Mutexes are short lived. Threads waiting on them will 2340 * hit thread_suspend_check() soon. 2341 */ 2342 } else if (p->p_state == PRS_NORMAL) { 2343 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2344 tdsigwakeup(td, sig, action, intrval); 2345 goto out; 2346 } 2347 2348 MPASS(action == SIG_DFL); 2349 2350 if (prop & SIGPROP_STOP) { 2351 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2352 goto out; 2353 p->p_flag |= P_STOPPED_SIG; 2354 p->p_xsig = sig; 2355 PROC_SLOCK(p); 2356 wakeup_swapper = sig_suspend_threads(td, p, 1); 2357 if (p->p_numthreads == p->p_suspcount) { 2358 /* 2359 * only thread sending signal to another 2360 * process can reach here, if thread is sending 2361 * signal to its process, because thread does 2362 * not suspend itself here, p_numthreads 2363 * should never be equal to p_suspcount. 2364 */ 2365 thread_stopped(p); 2366 PROC_SUNLOCK(p); 2367 sigqueue_delete_proc(p, p->p_xsig); 2368 } else 2369 PROC_SUNLOCK(p); 2370 if (wakeup_swapper) 2371 kick_proc0(); 2372 goto out; 2373 } 2374 } else { 2375 /* Not in "NORMAL" state. discard the signal. */ 2376 sigqueue_delete(sigqueue, sig); 2377 goto out; 2378 } 2379 2380 /* 2381 * The process is not stopped so we need to apply the signal to all the 2382 * running threads. 2383 */ 2384 runfast: 2385 tdsigwakeup(td, sig, action, intrval); 2386 PROC_SLOCK(p); 2387 thread_unsuspend(p); 2388 PROC_SUNLOCK(p); 2389 out: 2390 /* If we jump here, proc slock should not be owned. */ 2391 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2392 return (ret); 2393 } 2394 2395 /* 2396 * The force of a signal has been directed against a single 2397 * thread. We need to see what we can do about knocking it 2398 * out of any sleep it may be in etc. 2399 */ 2400 static void 2401 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2402 { 2403 struct proc *p = td->td_proc; 2404 register int prop; 2405 int wakeup_swapper; 2406 2407 wakeup_swapper = 0; 2408 PROC_LOCK_ASSERT(p, MA_OWNED); 2409 prop = sigprop(sig); 2410 2411 PROC_SLOCK(p); 2412 thread_lock(td); 2413 /* 2414 * Bring the priority of a thread up if we want it to get 2415 * killed in this lifetime. Be careful to avoid bumping the 2416 * priority of the idle thread, since we still allow to signal 2417 * kernel processes. 2418 */ 2419 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2420 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2421 sched_prio(td, PUSER); 2422 if (TD_ON_SLEEPQ(td)) { 2423 /* 2424 * If thread is sleeping uninterruptibly 2425 * we can't interrupt the sleep... the signal will 2426 * be noticed when the process returns through 2427 * trap() or syscall(). 2428 */ 2429 if ((td->td_flags & TDF_SINTR) == 0) 2430 goto out; 2431 /* 2432 * If SIGCONT is default (or ignored) and process is 2433 * asleep, we are finished; the process should not 2434 * be awakened. 2435 */ 2436 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2437 thread_unlock(td); 2438 PROC_SUNLOCK(p); 2439 sigqueue_delete(&p->p_sigqueue, sig); 2440 /* 2441 * It may be on either list in this state. 2442 * Remove from both for now. 2443 */ 2444 sigqueue_delete(&td->td_sigqueue, sig); 2445 return; 2446 } 2447 2448 /* 2449 * Don't awaken a sleeping thread for SIGSTOP if the 2450 * STOP signal is deferred. 2451 */ 2452 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2453 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2454 goto out; 2455 2456 /* 2457 * Give low priority threads a better chance to run. 2458 */ 2459 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2460 sched_prio(td, PUSER); 2461 2462 wakeup_swapper = sleepq_abort(td, intrval); 2463 } else { 2464 /* 2465 * Other states do nothing with the signal immediately, 2466 * other than kicking ourselves if we are running. 2467 * It will either never be noticed, or noticed very soon. 2468 */ 2469 #ifdef SMP 2470 if (TD_IS_RUNNING(td) && td != curthread) 2471 forward_signal(td); 2472 #endif 2473 } 2474 out: 2475 PROC_SUNLOCK(p); 2476 thread_unlock(td); 2477 if (wakeup_swapper) 2478 kick_proc0(); 2479 } 2480 2481 static int 2482 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2483 { 2484 struct thread *td2; 2485 int wakeup_swapper; 2486 2487 PROC_LOCK_ASSERT(p, MA_OWNED); 2488 PROC_SLOCK_ASSERT(p, MA_OWNED); 2489 2490 wakeup_swapper = 0; 2491 FOREACH_THREAD_IN_PROC(p, td2) { 2492 thread_lock(td2); 2493 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2494 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2495 (td2->td_flags & TDF_SINTR)) { 2496 if (td2->td_flags & TDF_SBDRY) { 2497 /* 2498 * Once a thread is asleep with 2499 * TDF_SBDRY and without TDF_SERESTART 2500 * or TDF_SEINTR set, it should never 2501 * become suspended due to this check. 2502 */ 2503 KASSERT(!TD_IS_SUSPENDED(td2), 2504 ("thread with deferred stops suspended")); 2505 if (TD_SBDRY_INTR(td2) && sending) { 2506 wakeup_swapper |= sleepq_abort(td2, 2507 TD_SBDRY_ERRNO(td2)); 2508 } 2509 } else if (!TD_IS_SUSPENDED(td2)) { 2510 thread_suspend_one(td2); 2511 } 2512 } else if (!TD_IS_SUSPENDED(td2)) { 2513 if (sending || td != td2) 2514 td2->td_flags |= TDF_ASTPENDING; 2515 #ifdef SMP 2516 if (TD_IS_RUNNING(td2) && td2 != td) 2517 forward_signal(td2); 2518 #endif 2519 } 2520 thread_unlock(td2); 2521 } 2522 return (wakeup_swapper); 2523 } 2524 2525 /* 2526 * Stop the process for an event deemed interesting to the debugger. If si is 2527 * non-NULL, this is a signal exchange; the new signal requested by the 2528 * debugger will be returned for handling. If si is NULL, this is some other 2529 * type of interesting event. The debugger may request a signal be delivered in 2530 * that case as well, however it will be deferred until it can be handled. 2531 */ 2532 int 2533 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2534 { 2535 struct proc *p = td->td_proc; 2536 struct thread *td2; 2537 ksiginfo_t ksi; 2538 int prop; 2539 2540 PROC_LOCK_ASSERT(p, MA_OWNED); 2541 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2542 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2543 &p->p_mtx.lock_object, "Stopping for traced signal"); 2544 2545 td->td_xsig = sig; 2546 2547 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2548 td->td_dbgflags |= TDB_XSIG; 2549 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2550 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2551 PROC_SLOCK(p); 2552 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2553 if (P_KILLED(p)) { 2554 /* 2555 * Ensure that, if we've been PT_KILLed, the 2556 * exit status reflects that. Another thread 2557 * may also be in ptracestop(), having just 2558 * received the SIGKILL, but this thread was 2559 * unsuspended first. 2560 */ 2561 td->td_dbgflags &= ~TDB_XSIG; 2562 td->td_xsig = SIGKILL; 2563 p->p_ptevents = 0; 2564 break; 2565 } 2566 if (p->p_flag & P_SINGLE_EXIT && 2567 !(td->td_dbgflags & TDB_EXIT)) { 2568 /* 2569 * Ignore ptrace stops except for thread exit 2570 * events when the process exits. 2571 */ 2572 td->td_dbgflags &= ~TDB_XSIG; 2573 PROC_SUNLOCK(p); 2574 return (0); 2575 } 2576 2577 /* 2578 * Make wait(2) work. Ensure that right after the 2579 * attach, the thread which was decided to become the 2580 * leader of attach gets reported to the waiter. 2581 * Otherwise, just avoid overwriting another thread's 2582 * assignment to p_xthread. If another thread has 2583 * already set p_xthread, the current thread will get 2584 * a chance to report itself upon the next iteration. 2585 */ 2586 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2587 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2588 p->p_xthread == NULL)) { 2589 p->p_xsig = sig; 2590 p->p_xthread = td; 2591 td->td_dbgflags &= ~TDB_FSTP; 2592 p->p_flag2 &= ~P2_PTRACE_FSTP; 2593 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2594 sig_suspend_threads(td, p, 0); 2595 } 2596 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2597 td->td_dbgflags &= ~TDB_STOPATFORK; 2598 cv_broadcast(&p->p_dbgwait); 2599 } 2600 stopme: 2601 thread_suspend_switch(td, p); 2602 if (p->p_xthread == td) 2603 p->p_xthread = NULL; 2604 if (!(p->p_flag & P_TRACED)) 2605 break; 2606 if (td->td_dbgflags & TDB_SUSPEND) { 2607 if (p->p_flag & P_SINGLE_EXIT) 2608 break; 2609 goto stopme; 2610 } 2611 } 2612 PROC_SUNLOCK(p); 2613 } 2614 2615 if (si != NULL && sig == td->td_xsig) { 2616 /* Parent wants us to take the original signal unchanged. */ 2617 si->ksi_flags |= KSI_HEAD; 2618 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2619 si->ksi_signo = 0; 2620 } else if (td->td_xsig != 0) { 2621 /* 2622 * If parent wants us to take a new signal, then it will leave 2623 * it in td->td_xsig; otherwise we just look for signals again. 2624 */ 2625 ksiginfo_init(&ksi); 2626 ksi.ksi_signo = td->td_xsig; 2627 ksi.ksi_flags |= KSI_PTRACE; 2628 prop = sigprop(td->td_xsig); 2629 td2 = sigtd(p, td->td_xsig, prop); 2630 tdsendsignal(p, td2, td->td_xsig, &ksi); 2631 if (td != td2) 2632 return (0); 2633 } 2634 2635 return (td->td_xsig); 2636 } 2637 2638 static void 2639 reschedule_signals(struct proc *p, sigset_t block, int flags) 2640 { 2641 struct sigacts *ps; 2642 struct thread *td; 2643 int sig; 2644 2645 PROC_LOCK_ASSERT(p, MA_OWNED); 2646 ps = p->p_sigacts; 2647 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2648 MA_OWNED : MA_NOTOWNED); 2649 if (SIGISEMPTY(p->p_siglist)) 2650 return; 2651 SIGSETAND(block, p->p_siglist); 2652 while ((sig = sig_ffs(&block)) != 0) { 2653 SIGDELSET(block, sig); 2654 td = sigtd(p, sig, 0); 2655 signotify(td); 2656 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2657 mtx_lock(&ps->ps_mtx); 2658 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2659 tdsigwakeup(td, sig, SIG_CATCH, 2660 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2661 ERESTART)); 2662 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2663 mtx_unlock(&ps->ps_mtx); 2664 } 2665 } 2666 2667 void 2668 tdsigcleanup(struct thread *td) 2669 { 2670 struct proc *p; 2671 sigset_t unblocked; 2672 2673 p = td->td_proc; 2674 PROC_LOCK_ASSERT(p, MA_OWNED); 2675 2676 sigqueue_flush(&td->td_sigqueue); 2677 if (p->p_numthreads == 1) 2678 return; 2679 2680 /* 2681 * Since we cannot handle signals, notify signal post code 2682 * about this by filling the sigmask. 2683 * 2684 * Also, if needed, wake up thread(s) that do not block the 2685 * same signals as the exiting thread, since the thread might 2686 * have been selected for delivery and woken up. 2687 */ 2688 SIGFILLSET(unblocked); 2689 SIGSETNAND(unblocked, td->td_sigmask); 2690 SIGFILLSET(td->td_sigmask); 2691 reschedule_signals(p, unblocked, 0); 2692 2693 } 2694 2695 static int 2696 sigdeferstop_curr_flags(int cflags) 2697 { 2698 2699 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2700 (cflags & TDF_SBDRY) != 0); 2701 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2702 } 2703 2704 /* 2705 * Defer the delivery of SIGSTOP for the current thread, according to 2706 * the requested mode. Returns previous flags, which must be restored 2707 * by sigallowstop(). 2708 * 2709 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2710 * cleared by the current thread, which allow the lock-less read-only 2711 * accesses below. 2712 */ 2713 int 2714 sigdeferstop_impl(int mode) 2715 { 2716 struct thread *td; 2717 int cflags, nflags; 2718 2719 td = curthread; 2720 cflags = sigdeferstop_curr_flags(td->td_flags); 2721 switch (mode) { 2722 case SIGDEFERSTOP_NOP: 2723 nflags = cflags; 2724 break; 2725 case SIGDEFERSTOP_OFF: 2726 nflags = 0; 2727 break; 2728 case SIGDEFERSTOP_SILENT: 2729 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2730 break; 2731 case SIGDEFERSTOP_EINTR: 2732 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2733 break; 2734 case SIGDEFERSTOP_ERESTART: 2735 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2736 break; 2737 default: 2738 panic("sigdeferstop: invalid mode %x", mode); 2739 break; 2740 } 2741 if (cflags == nflags) 2742 return (SIGDEFERSTOP_VAL_NCHG); 2743 thread_lock(td); 2744 td->td_flags = (td->td_flags & ~cflags) | nflags; 2745 thread_unlock(td); 2746 return (cflags); 2747 } 2748 2749 /* 2750 * Restores the STOP handling mode, typically permitting the delivery 2751 * of SIGSTOP for the current thread. This does not immediately 2752 * suspend if a stop was posted. Instead, the thread will suspend 2753 * either via ast() or a subsequent interruptible sleep. 2754 */ 2755 void 2756 sigallowstop_impl(int prev) 2757 { 2758 struct thread *td; 2759 int cflags; 2760 2761 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2762 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2763 ("sigallowstop: incorrect previous mode %x", prev)); 2764 td = curthread; 2765 cflags = sigdeferstop_curr_flags(td->td_flags); 2766 if (cflags != prev) { 2767 thread_lock(td); 2768 td->td_flags = (td->td_flags & ~cflags) | prev; 2769 thread_unlock(td); 2770 } 2771 } 2772 2773 /* 2774 * If the current process has received a signal (should be caught or cause 2775 * termination, should interrupt current syscall), return the signal number. 2776 * Stop signals with default action are processed immediately, then cleared; 2777 * they aren't returned. This is checked after each entry to the system for 2778 * a syscall or trap (though this can usually be done without calling issignal 2779 * by checking the pending signal masks in cursig.) The normal call 2780 * sequence is 2781 * 2782 * while (sig = cursig(curthread)) 2783 * postsig(sig); 2784 */ 2785 static int 2786 issignal(struct thread *td) 2787 { 2788 struct proc *p; 2789 struct sigacts *ps; 2790 struct sigqueue *queue; 2791 sigset_t sigpending; 2792 int sig, prop; 2793 2794 p = td->td_proc; 2795 ps = p->p_sigacts; 2796 mtx_assert(&ps->ps_mtx, MA_OWNED); 2797 PROC_LOCK_ASSERT(p, MA_OWNED); 2798 for (;;) { 2799 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2800 2801 sigpending = td->td_sigqueue.sq_signals; 2802 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2803 SIGSETNAND(sigpending, td->td_sigmask); 2804 2805 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2806 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2807 SIG_STOPSIGMASK(sigpending); 2808 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2809 return (0); 2810 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2811 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2812 SIGISMEMBER(sigpending, SIGSTOP)) { 2813 /* 2814 * If debugger just attached, always consume 2815 * SIGSTOP from ptrace(PT_ATTACH) first, to 2816 * execute the debugger attach ritual in 2817 * order. 2818 */ 2819 sig = SIGSTOP; 2820 td->td_dbgflags |= TDB_FSTP; 2821 } else { 2822 sig = sig_ffs(&sigpending); 2823 } 2824 2825 if (p->p_stops & S_SIG) { 2826 mtx_unlock(&ps->ps_mtx); 2827 stopevent(p, S_SIG, sig); 2828 mtx_lock(&ps->ps_mtx); 2829 } 2830 2831 /* 2832 * We should see pending but ignored signals 2833 * only if P_TRACED was on when they were posted. 2834 */ 2835 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2836 sigqueue_delete(&td->td_sigqueue, sig); 2837 sigqueue_delete(&p->p_sigqueue, sig); 2838 continue; 2839 } 2840 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2841 /* 2842 * If traced, always stop. 2843 * Remove old signal from queue before the stop. 2844 * XXX shrug off debugger, it causes siginfo to 2845 * be thrown away. 2846 */ 2847 queue = &td->td_sigqueue; 2848 td->td_dbgksi.ksi_signo = 0; 2849 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2850 queue = &p->p_sigqueue; 2851 sigqueue_get(queue, sig, &td->td_dbgksi); 2852 } 2853 2854 mtx_unlock(&ps->ps_mtx); 2855 sig = ptracestop(td, sig, &td->td_dbgksi); 2856 mtx_lock(&ps->ps_mtx); 2857 2858 /* 2859 * Keep looking if the debugger discarded the signal 2860 * or replaced it with a masked signal. 2861 * 2862 * If the traced bit got turned off, go back up 2863 * to the top to rescan signals. This ensures 2864 * that p_sig* and p_sigact are consistent. 2865 */ 2866 if (sig == 0 || (p->p_flag & P_TRACED) == 0) 2867 continue; 2868 } 2869 2870 prop = sigprop(sig); 2871 2872 /* 2873 * Decide whether the signal should be returned. 2874 * Return the signal's number, or fall through 2875 * to clear it from the pending mask. 2876 */ 2877 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2878 2879 case (intptr_t)SIG_DFL: 2880 /* 2881 * Don't take default actions on system processes. 2882 */ 2883 if (p->p_pid <= 1) { 2884 #ifdef DIAGNOSTIC 2885 /* 2886 * Are you sure you want to ignore SIGSEGV 2887 * in init? XXX 2888 */ 2889 printf("Process (pid %lu) got signal %d\n", 2890 (u_long)p->p_pid, sig); 2891 #endif 2892 break; /* == ignore */ 2893 } 2894 /* 2895 * If there is a pending stop signal to process 2896 * with default action, stop here, 2897 * then clear the signal. However, 2898 * if process is member of an orphaned 2899 * process group, ignore tty stop signals. 2900 */ 2901 if (prop & SIGPROP_STOP) { 2902 if (p->p_flag & (P_TRACED|P_WEXIT) || 2903 (p->p_pgrp->pg_jobc == 0 && 2904 prop & SIGPROP_TTYSTOP)) 2905 break; /* == ignore */ 2906 if (TD_SBDRY_INTR(td)) { 2907 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2908 ("lost TDF_SBDRY")); 2909 return (-1); 2910 } 2911 mtx_unlock(&ps->ps_mtx); 2912 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2913 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2914 sigqueue_delete(&td->td_sigqueue, sig); 2915 sigqueue_delete(&p->p_sigqueue, sig); 2916 p->p_flag |= P_STOPPED_SIG; 2917 p->p_xsig = sig; 2918 PROC_SLOCK(p); 2919 sig_suspend_threads(td, p, 0); 2920 thread_suspend_switch(td, p); 2921 PROC_SUNLOCK(p); 2922 mtx_lock(&ps->ps_mtx); 2923 goto next; 2924 } else if (prop & SIGPROP_IGNORE) { 2925 /* 2926 * Except for SIGCONT, shouldn't get here. 2927 * Default action is to ignore; drop it. 2928 */ 2929 break; /* == ignore */ 2930 } else 2931 return (sig); 2932 /*NOTREACHED*/ 2933 2934 case (intptr_t)SIG_IGN: 2935 /* 2936 * Masking above should prevent us ever trying 2937 * to take action on an ignored signal other 2938 * than SIGCONT, unless process is traced. 2939 */ 2940 if ((prop & SIGPROP_CONT) == 0 && 2941 (p->p_flag & P_TRACED) == 0) 2942 printf("issignal\n"); 2943 break; /* == ignore */ 2944 2945 default: 2946 /* 2947 * This signal has an action, let 2948 * postsig() process it. 2949 */ 2950 return (sig); 2951 } 2952 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2953 sigqueue_delete(&p->p_sigqueue, sig); 2954 next:; 2955 } 2956 /* NOTREACHED */ 2957 } 2958 2959 void 2960 thread_stopped(struct proc *p) 2961 { 2962 int n; 2963 2964 PROC_LOCK_ASSERT(p, MA_OWNED); 2965 PROC_SLOCK_ASSERT(p, MA_OWNED); 2966 n = p->p_suspcount; 2967 if (p == curproc) 2968 n++; 2969 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2970 PROC_SUNLOCK(p); 2971 p->p_flag &= ~P_WAITED; 2972 PROC_LOCK(p->p_pptr); 2973 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2974 CLD_TRAPPED : CLD_STOPPED); 2975 PROC_UNLOCK(p->p_pptr); 2976 PROC_SLOCK(p); 2977 } 2978 } 2979 2980 /* 2981 * Take the action for the specified signal 2982 * from the current set of pending signals. 2983 */ 2984 int 2985 postsig(sig) 2986 register int sig; 2987 { 2988 struct thread *td = curthread; 2989 register struct proc *p = td->td_proc; 2990 struct sigacts *ps; 2991 sig_t action; 2992 ksiginfo_t ksi; 2993 sigset_t returnmask; 2994 2995 KASSERT(sig != 0, ("postsig")); 2996 2997 PROC_LOCK_ASSERT(p, MA_OWNED); 2998 ps = p->p_sigacts; 2999 mtx_assert(&ps->ps_mtx, MA_OWNED); 3000 ksiginfo_init(&ksi); 3001 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3002 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3003 return (0); 3004 ksi.ksi_signo = sig; 3005 if (ksi.ksi_code == SI_TIMER) 3006 itimer_accept(p, ksi.ksi_timerid, &ksi); 3007 action = ps->ps_sigact[_SIG_IDX(sig)]; 3008 #ifdef KTRACE 3009 if (KTRPOINT(td, KTR_PSIG)) 3010 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3011 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3012 #endif 3013 if (p->p_stops & S_SIG) { 3014 mtx_unlock(&ps->ps_mtx); 3015 stopevent(p, S_SIG, sig); 3016 mtx_lock(&ps->ps_mtx); 3017 } 3018 3019 if (action == SIG_DFL) { 3020 /* 3021 * Default action, where the default is to kill 3022 * the process. (Other cases were ignored above.) 3023 */ 3024 mtx_unlock(&ps->ps_mtx); 3025 sigexit(td, sig); 3026 /* NOTREACHED */ 3027 } else { 3028 /* 3029 * If we get here, the signal must be caught. 3030 */ 3031 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 3032 ("postsig action")); 3033 /* 3034 * Set the new mask value and also defer further 3035 * occurrences of this signal. 3036 * 3037 * Special case: user has done a sigsuspend. Here the 3038 * current mask is not of interest, but rather the 3039 * mask from before the sigsuspend is what we want 3040 * restored after the signal processing is completed. 3041 */ 3042 if (td->td_pflags & TDP_OLDMASK) { 3043 returnmask = td->td_oldsigmask; 3044 td->td_pflags &= ~TDP_OLDMASK; 3045 } else 3046 returnmask = td->td_sigmask; 3047 3048 if (p->p_sig == sig) { 3049 p->p_code = 0; 3050 p->p_sig = 0; 3051 } 3052 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3053 postsig_done(sig, td, ps); 3054 } 3055 return (1); 3056 } 3057 3058 /* 3059 * Kill the current process for stated reason. 3060 */ 3061 void 3062 killproc(p, why) 3063 struct proc *p; 3064 char *why; 3065 { 3066 3067 PROC_LOCK_ASSERT(p, MA_OWNED); 3068 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3069 p->p_comm); 3070 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3071 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3072 p->p_flag |= P_WKILLED; 3073 kern_psignal(p, SIGKILL); 3074 } 3075 3076 /* 3077 * Force the current process to exit with the specified signal, dumping core 3078 * if appropriate. We bypass the normal tests for masked and caught signals, 3079 * allowing unrecoverable failures to terminate the process without changing 3080 * signal state. Mark the accounting record with the signal termination. 3081 * If dumping core, save the signal number for the debugger. Calls exit and 3082 * does not return. 3083 */ 3084 void 3085 sigexit(td, sig) 3086 struct thread *td; 3087 int sig; 3088 { 3089 struct proc *p = td->td_proc; 3090 3091 PROC_LOCK_ASSERT(p, MA_OWNED); 3092 p->p_acflag |= AXSIG; 3093 /* 3094 * We must be single-threading to generate a core dump. This 3095 * ensures that the registers in the core file are up-to-date. 3096 * Also, the ELF dump handler assumes that the thread list doesn't 3097 * change out from under it. 3098 * 3099 * XXX If another thread attempts to single-thread before us 3100 * (e.g. via fork()), we won't get a dump at all. 3101 */ 3102 if ((sigprop(sig) & SIGPROP_CORE) && 3103 thread_single(p, SINGLE_NO_EXIT) == 0) { 3104 p->p_sig = sig; 3105 /* 3106 * Log signals which would cause core dumps 3107 * (Log as LOG_INFO to appease those who don't want 3108 * these messages.) 3109 * XXX : Todo, as well as euid, write out ruid too 3110 * Note that coredump() drops proc lock. 3111 */ 3112 if (coredump(td) == 0) 3113 sig |= WCOREFLAG; 3114 if (kern_logsigexit) 3115 log(LOG_INFO, 3116 "pid %d (%s), uid %d: exited on signal %d%s\n", 3117 p->p_pid, p->p_comm, 3118 td->td_ucred ? td->td_ucred->cr_uid : -1, 3119 sig &~ WCOREFLAG, 3120 sig & WCOREFLAG ? " (core dumped)" : ""); 3121 } else 3122 PROC_UNLOCK(p); 3123 exit1(td, 0, sig); 3124 /* NOTREACHED */ 3125 } 3126 3127 /* 3128 * Send queued SIGCHLD to parent when child process's state 3129 * is changed. 3130 */ 3131 static void 3132 sigparent(struct proc *p, int reason, int status) 3133 { 3134 PROC_LOCK_ASSERT(p, MA_OWNED); 3135 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3136 3137 if (p->p_ksi != NULL) { 3138 p->p_ksi->ksi_signo = SIGCHLD; 3139 p->p_ksi->ksi_code = reason; 3140 p->p_ksi->ksi_status = status; 3141 p->p_ksi->ksi_pid = p->p_pid; 3142 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3143 if (KSI_ONQ(p->p_ksi)) 3144 return; 3145 } 3146 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3147 } 3148 3149 static void 3150 childproc_jobstate(struct proc *p, int reason, int sig) 3151 { 3152 struct sigacts *ps; 3153 3154 PROC_LOCK_ASSERT(p, MA_OWNED); 3155 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3156 3157 /* 3158 * Wake up parent sleeping in kern_wait(), also send 3159 * SIGCHLD to parent, but SIGCHLD does not guarantee 3160 * that parent will awake, because parent may masked 3161 * the signal. 3162 */ 3163 p->p_pptr->p_flag |= P_STATCHILD; 3164 wakeup(p->p_pptr); 3165 3166 ps = p->p_pptr->p_sigacts; 3167 mtx_lock(&ps->ps_mtx); 3168 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3169 mtx_unlock(&ps->ps_mtx); 3170 sigparent(p, reason, sig); 3171 } else 3172 mtx_unlock(&ps->ps_mtx); 3173 } 3174 3175 void 3176 childproc_stopped(struct proc *p, int reason) 3177 { 3178 3179 childproc_jobstate(p, reason, p->p_xsig); 3180 } 3181 3182 void 3183 childproc_continued(struct proc *p) 3184 { 3185 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3186 } 3187 3188 void 3189 childproc_exited(struct proc *p) 3190 { 3191 int reason, status; 3192 3193 if (WCOREDUMP(p->p_xsig)) { 3194 reason = CLD_DUMPED; 3195 status = WTERMSIG(p->p_xsig); 3196 } else if (WIFSIGNALED(p->p_xsig)) { 3197 reason = CLD_KILLED; 3198 status = WTERMSIG(p->p_xsig); 3199 } else { 3200 reason = CLD_EXITED; 3201 status = p->p_xexit; 3202 } 3203 /* 3204 * XXX avoid calling wakeup(p->p_pptr), the work is 3205 * done in exit1(). 3206 */ 3207 sigparent(p, reason, status); 3208 } 3209 3210 /* 3211 * We only have 1 character for the core count in the format 3212 * string, so the range will be 0-9 3213 */ 3214 #define MAX_NUM_CORE_FILES 10 3215 #ifndef NUM_CORE_FILES 3216 #define NUM_CORE_FILES 5 3217 #endif 3218 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3219 static int num_cores = NUM_CORE_FILES; 3220 3221 static int 3222 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3223 { 3224 int error; 3225 int new_val; 3226 3227 new_val = num_cores; 3228 error = sysctl_handle_int(oidp, &new_val, 0, req); 3229 if (error != 0 || req->newptr == NULL) 3230 return (error); 3231 if (new_val > MAX_NUM_CORE_FILES) 3232 new_val = MAX_NUM_CORE_FILES; 3233 if (new_val < 0) 3234 new_val = 0; 3235 num_cores = new_val; 3236 return (0); 3237 } 3238 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3239 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3240 3241 #define GZ_SUFFIX ".gz" 3242 3243 #ifdef GZIO 3244 static int compress_user_cores = 1; 3245 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN, 3246 &compress_user_cores, 0, "Compression of user corefiles"); 3247 3248 int compress_user_cores_gzlevel = 6; 3249 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN, 3250 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level"); 3251 #else 3252 static int compress_user_cores = 0; 3253 #endif 3254 3255 /* 3256 * Protect the access to corefilename[] by allproc_lock. 3257 */ 3258 #define corefilename_lock allproc_lock 3259 3260 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3261 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3262 3263 static int 3264 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3265 { 3266 int error; 3267 3268 sx_xlock(&corefilename_lock); 3269 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3270 req); 3271 sx_xunlock(&corefilename_lock); 3272 3273 return (error); 3274 } 3275 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3276 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3277 "Process corefile name format string"); 3278 3279 /* 3280 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3281 * Expand the name described in corefilename, using name, uid, and pid 3282 * and open/create core file. 3283 * corefilename is a printf-like string, with three format specifiers: 3284 * %N name of process ("name") 3285 * %P process id (pid) 3286 * %U user id (uid) 3287 * For example, "%N.core" is the default; they can be disabled completely 3288 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3289 * This is controlled by the sysctl variable kern.corefile (see above). 3290 */ 3291 static int 3292 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3293 int compress, struct vnode **vpp, char **namep) 3294 { 3295 struct nameidata nd; 3296 struct sbuf sb; 3297 const char *format; 3298 char *hostname, *name; 3299 int indexpos, i, error, cmode, flags, oflags; 3300 3301 hostname = NULL; 3302 format = corefilename; 3303 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3304 indexpos = -1; 3305 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3306 sx_slock(&corefilename_lock); 3307 for (i = 0; format[i] != '\0'; i++) { 3308 switch (format[i]) { 3309 case '%': /* Format character */ 3310 i++; 3311 switch (format[i]) { 3312 case '%': 3313 sbuf_putc(&sb, '%'); 3314 break; 3315 case 'H': /* hostname */ 3316 if (hostname == NULL) { 3317 hostname = malloc(MAXHOSTNAMELEN, 3318 M_TEMP, M_WAITOK); 3319 } 3320 getcredhostname(td->td_ucred, hostname, 3321 MAXHOSTNAMELEN); 3322 sbuf_printf(&sb, "%s", hostname); 3323 break; 3324 case 'I': /* autoincrementing index */ 3325 sbuf_printf(&sb, "0"); 3326 indexpos = sbuf_len(&sb) - 1; 3327 break; 3328 case 'N': /* process name */ 3329 sbuf_printf(&sb, "%s", comm); 3330 break; 3331 case 'P': /* process id */ 3332 sbuf_printf(&sb, "%u", pid); 3333 break; 3334 case 'U': /* user id */ 3335 sbuf_printf(&sb, "%u", uid); 3336 break; 3337 default: 3338 log(LOG_ERR, 3339 "Unknown format character %c in " 3340 "corename `%s'\n", format[i], format); 3341 break; 3342 } 3343 break; 3344 default: 3345 sbuf_putc(&sb, format[i]); 3346 break; 3347 } 3348 } 3349 sx_sunlock(&corefilename_lock); 3350 free(hostname, M_TEMP); 3351 if (compress) 3352 sbuf_printf(&sb, GZ_SUFFIX); 3353 if (sbuf_error(&sb) != 0) { 3354 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3355 "long\n", (long)pid, comm, (u_long)uid); 3356 sbuf_delete(&sb); 3357 free(name, M_TEMP); 3358 return (ENOMEM); 3359 } 3360 sbuf_finish(&sb); 3361 sbuf_delete(&sb); 3362 3363 cmode = S_IRUSR | S_IWUSR; 3364 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3365 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3366 3367 /* 3368 * If the core format has a %I in it, then we need to check 3369 * for existing corefiles before returning a name. 3370 * To do this we iterate over 0..num_cores to find a 3371 * non-existing core file name to use. 3372 */ 3373 if (indexpos != -1) { 3374 for (i = 0; i < num_cores; i++) { 3375 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3376 name[indexpos] = '0' + i; 3377 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3378 error = vn_open_cred(&nd, &flags, cmode, oflags, 3379 td->td_ucred, NULL); 3380 if (error) { 3381 if (error == EEXIST) 3382 continue; 3383 log(LOG_ERR, 3384 "pid %d (%s), uid (%u): Path `%s' failed " 3385 "on initial open test, error = %d\n", 3386 pid, comm, uid, name, error); 3387 } 3388 goto out; 3389 } 3390 } 3391 3392 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3393 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3394 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3395 out: 3396 if (error) { 3397 #ifdef AUDIT 3398 audit_proc_coredump(td, name, error); 3399 #endif 3400 free(name, M_TEMP); 3401 return (error); 3402 } 3403 NDFREE(&nd, NDF_ONLY_PNBUF); 3404 *vpp = nd.ni_vp; 3405 *namep = name; 3406 return (0); 3407 } 3408 3409 static int 3410 coredump_sanitise_path(const char *path) 3411 { 3412 size_t i; 3413 3414 /* 3415 * Only send a subset of ASCII to devd(8) because it 3416 * might pass these strings to sh -c. 3417 */ 3418 for (i = 0; path[i]; i++) 3419 if (!(isalpha(path[i]) || isdigit(path[i])) && 3420 path[i] != '/' && path[i] != '.' && 3421 path[i] != '-') 3422 return (0); 3423 3424 return (1); 3425 } 3426 3427 /* 3428 * Dump a process' core. The main routine does some 3429 * policy checking, and creates the name of the coredump; 3430 * then it passes on a vnode and a size limit to the process-specific 3431 * coredump routine if there is one; if there _is not_ one, it returns 3432 * ENOSYS; otherwise it returns the error from the process-specific routine. 3433 */ 3434 3435 static int 3436 coredump(struct thread *td) 3437 { 3438 struct proc *p = td->td_proc; 3439 struct ucred *cred = td->td_ucred; 3440 struct vnode *vp; 3441 struct flock lf; 3442 struct vattr vattr; 3443 int error, error1, locked; 3444 char *name; /* name of corefile */ 3445 void *rl_cookie; 3446 off_t limit; 3447 char *data = NULL; 3448 char *fullpath, *freepath = NULL; 3449 size_t len; 3450 static const char comm_name[] = "comm="; 3451 static const char core_name[] = "core="; 3452 3453 PROC_LOCK_ASSERT(p, MA_OWNED); 3454 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3455 _STOPEVENT(p, S_CORE, 0); 3456 3457 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3458 (p->p_flag2 & P2_NOTRACE) != 0) { 3459 PROC_UNLOCK(p); 3460 return (EFAULT); 3461 } 3462 3463 /* 3464 * Note that the bulk of limit checking is done after 3465 * the corefile is created. The exception is if the limit 3466 * for corefiles is 0, in which case we don't bother 3467 * creating the corefile at all. This layout means that 3468 * a corefile is truncated instead of not being created, 3469 * if it is larger than the limit. 3470 */ 3471 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3472 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3473 PROC_UNLOCK(p); 3474 return (EFBIG); 3475 } 3476 PROC_UNLOCK(p); 3477 3478 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3479 compress_user_cores, &vp, &name); 3480 if (error != 0) 3481 return (error); 3482 3483 /* 3484 * Don't dump to non-regular files or files with links. 3485 * Do not dump into system files. 3486 */ 3487 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3488 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3489 VOP_UNLOCK(vp, 0); 3490 error = EFAULT; 3491 goto out; 3492 } 3493 3494 VOP_UNLOCK(vp, 0); 3495 3496 /* Postpone other writers, including core dumps of other processes. */ 3497 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3498 3499 lf.l_whence = SEEK_SET; 3500 lf.l_start = 0; 3501 lf.l_len = 0; 3502 lf.l_type = F_WRLCK; 3503 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3504 3505 VATTR_NULL(&vattr); 3506 vattr.va_size = 0; 3507 if (set_core_nodump_flag) 3508 vattr.va_flags = UF_NODUMP; 3509 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3510 VOP_SETATTR(vp, &vattr, cred); 3511 VOP_UNLOCK(vp, 0); 3512 PROC_LOCK(p); 3513 p->p_acflag |= ACORE; 3514 PROC_UNLOCK(p); 3515 3516 if (p->p_sysent->sv_coredump != NULL) { 3517 error = p->p_sysent->sv_coredump(td, vp, limit, 3518 compress_user_cores ? IMGACT_CORE_COMPRESS : 0); 3519 } else { 3520 error = ENOSYS; 3521 } 3522 3523 if (locked) { 3524 lf.l_type = F_UNLCK; 3525 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3526 } 3527 vn_rangelock_unlock(vp, rl_cookie); 3528 3529 /* 3530 * Notify the userland helper that a process triggered a core dump. 3531 * This allows the helper to run an automated debugging session. 3532 */ 3533 if (error != 0 || coredump_devctl == 0) 3534 goto out; 3535 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3536 sizeof(' ') + sizeof(core_name) - 1; 3537 data = malloc(len, M_TEMP, M_WAITOK); 3538 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3539 goto out; 3540 if (!coredump_sanitise_path(fullpath)) 3541 goto out; 3542 snprintf(data, len, "%s%s ", comm_name, fullpath); 3543 free(freepath, M_TEMP); 3544 freepath = NULL; 3545 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3546 goto out; 3547 if (!coredump_sanitise_path(fullpath)) 3548 goto out; 3549 strlcat(data, core_name, len); 3550 strlcat(data, fullpath, len); 3551 devctl_notify("kernel", "signal", "coredump", data); 3552 out: 3553 error1 = vn_close(vp, FWRITE, cred, td); 3554 if (error == 0) 3555 error = error1; 3556 #ifdef AUDIT 3557 audit_proc_coredump(td, name, error); 3558 #endif 3559 free(freepath, M_TEMP); 3560 free(data, M_TEMP); 3561 free(name, M_TEMP); 3562 return (error); 3563 } 3564 3565 /* 3566 * Nonexistent system call-- signal process (may want to handle it). Flag 3567 * error in case process won't see signal immediately (blocked or ignored). 3568 */ 3569 #ifndef _SYS_SYSPROTO_H_ 3570 struct nosys_args { 3571 int dummy; 3572 }; 3573 #endif 3574 /* ARGSUSED */ 3575 int 3576 nosys(td, args) 3577 struct thread *td; 3578 struct nosys_args *args; 3579 { 3580 struct proc *p = td->td_proc; 3581 3582 PROC_LOCK(p); 3583 tdsignal(td, SIGSYS); 3584 PROC_UNLOCK(p); 3585 return (ENOSYS); 3586 } 3587 3588 /* 3589 * Send a SIGIO or SIGURG signal to a process or process group using stored 3590 * credentials rather than those of the current process. 3591 */ 3592 void 3593 pgsigio(sigiop, sig, checkctty) 3594 struct sigio **sigiop; 3595 int sig, checkctty; 3596 { 3597 ksiginfo_t ksi; 3598 struct sigio *sigio; 3599 3600 ksiginfo_init(&ksi); 3601 ksi.ksi_signo = sig; 3602 ksi.ksi_code = SI_KERNEL; 3603 3604 SIGIO_LOCK(); 3605 sigio = *sigiop; 3606 if (sigio == NULL) { 3607 SIGIO_UNLOCK(); 3608 return; 3609 } 3610 if (sigio->sio_pgid > 0) { 3611 PROC_LOCK(sigio->sio_proc); 3612 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3613 kern_psignal(sigio->sio_proc, sig); 3614 PROC_UNLOCK(sigio->sio_proc); 3615 } else if (sigio->sio_pgid < 0) { 3616 struct proc *p; 3617 3618 PGRP_LOCK(sigio->sio_pgrp); 3619 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3620 PROC_LOCK(p); 3621 if (p->p_state == PRS_NORMAL && 3622 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3623 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3624 kern_psignal(p, sig); 3625 PROC_UNLOCK(p); 3626 } 3627 PGRP_UNLOCK(sigio->sio_pgrp); 3628 } 3629 SIGIO_UNLOCK(); 3630 } 3631 3632 static int 3633 filt_sigattach(struct knote *kn) 3634 { 3635 struct proc *p = curproc; 3636 3637 kn->kn_ptr.p_proc = p; 3638 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3639 3640 knlist_add(p->p_klist, kn, 0); 3641 3642 return (0); 3643 } 3644 3645 static void 3646 filt_sigdetach(struct knote *kn) 3647 { 3648 struct proc *p = kn->kn_ptr.p_proc; 3649 3650 knlist_remove(p->p_klist, kn, 0); 3651 } 3652 3653 /* 3654 * signal knotes are shared with proc knotes, so we apply a mask to 3655 * the hint in order to differentiate them from process hints. This 3656 * could be avoided by using a signal-specific knote list, but probably 3657 * isn't worth the trouble. 3658 */ 3659 static int 3660 filt_signal(struct knote *kn, long hint) 3661 { 3662 3663 if (hint & NOTE_SIGNAL) { 3664 hint &= ~NOTE_SIGNAL; 3665 3666 if (kn->kn_id == hint) 3667 kn->kn_data++; 3668 } 3669 return (kn->kn_data != 0); 3670 } 3671 3672 struct sigacts * 3673 sigacts_alloc(void) 3674 { 3675 struct sigacts *ps; 3676 3677 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3678 refcount_init(&ps->ps_refcnt, 1); 3679 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3680 return (ps); 3681 } 3682 3683 void 3684 sigacts_free(struct sigacts *ps) 3685 { 3686 3687 if (refcount_release(&ps->ps_refcnt) == 0) 3688 return; 3689 mtx_destroy(&ps->ps_mtx); 3690 free(ps, M_SUBPROC); 3691 } 3692 3693 struct sigacts * 3694 sigacts_hold(struct sigacts *ps) 3695 { 3696 3697 refcount_acquire(&ps->ps_refcnt); 3698 return (ps); 3699 } 3700 3701 void 3702 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3703 { 3704 3705 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3706 mtx_lock(&src->ps_mtx); 3707 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3708 mtx_unlock(&src->ps_mtx); 3709 } 3710 3711 int 3712 sigacts_shared(struct sigacts *ps) 3713 { 3714 3715 return (ps->ps_refcnt > 1); 3716 } 3717