1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/ptrace.h> 69 #include <sys/posix4.h> 70 #include <sys/pioctl.h> 71 #include <sys/racct.h> 72 #include <sys/resourcevar.h> 73 #include <sys/sdt.h> 74 #include <sys/sbuf.h> 75 #include <sys/sleepqueue.h> 76 #include <sys/smp.h> 77 #include <sys/stat.h> 78 #include <sys/sx.h> 79 #include <sys/syscallsubr.h> 80 #include <sys/sysctl.h> 81 #include <sys/sysent.h> 82 #include <sys/syslog.h> 83 #include <sys/sysproto.h> 84 #include <sys/timers.h> 85 #include <sys/unistd.h> 86 #include <sys/wait.h> 87 #include <vm/vm.h> 88 #include <vm/vm_extern.h> 89 #include <vm/uma.h> 90 91 #include <sys/jail.h> 92 93 #include <machine/cpu.h> 94 95 #include <security/audit/audit.h> 96 97 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 98 99 SDT_PROVIDER_DECLARE(proc); 100 SDT_PROBE_DEFINE3(proc, , , signal__send, 101 "struct thread *", "struct proc *", "int"); 102 SDT_PROBE_DEFINE2(proc, , , signal__clear, 103 "int", "ksiginfo_t *"); 104 SDT_PROBE_DEFINE3(proc, , , signal__discard, 105 "struct thread *", "struct proc *", "int"); 106 107 static int coredump(struct thread *); 108 static int killpg1(struct thread *td, int sig, int pgid, int all, 109 ksiginfo_t *ksi); 110 static int issignal(struct thread *td); 111 static int sigprop(int sig); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static int sig_suspend_threads(struct thread *, struct proc *, int); 114 static int filt_sigattach(struct knote *kn); 115 static void filt_sigdetach(struct knote *kn); 116 static int filt_signal(struct knote *kn, long hint); 117 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 118 static void sigqueue_start(void); 119 120 static uma_zone_t ksiginfo_zone = NULL; 121 struct filterops sig_filtops = { 122 .f_isfd = 0, 123 .f_attach = filt_sigattach, 124 .f_detach = filt_sigdetach, 125 .f_event = filt_signal, 126 }; 127 128 static int kern_logsigexit = 1; 129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 130 &kern_logsigexit, 0, 131 "Log processes quitting on abnormal signals to syslog(3)"); 132 133 static int kern_forcesigexit = 1; 134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 135 &kern_forcesigexit, 0, "Force trap signal to be handled"); 136 137 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 138 "POSIX real time signal"); 139 140 static int max_pending_per_proc = 128; 141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 142 &max_pending_per_proc, 0, "Max pending signals per proc"); 143 144 static int preallocate_siginfo = 1024; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 146 &preallocate_siginfo, 0, "Preallocated signal memory size"); 147 148 static int signal_overflow = 0; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 150 &signal_overflow, 0, "Number of signals overflew"); 151 152 static int signal_alloc_fail = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 154 &signal_alloc_fail, 0, "signals failed to be allocated"); 155 156 static int kern_lognosys = 0; 157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 158 "Log invalid syscalls"); 159 160 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 161 162 /* 163 * Policy -- Can ucred cr1 send SIGIO to process cr2? 164 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 165 * in the right situations. 166 */ 167 #define CANSIGIO(cr1, cr2) \ 168 ((cr1)->cr_uid == 0 || \ 169 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 170 (cr1)->cr_uid == (cr2)->cr_ruid || \ 171 (cr1)->cr_ruid == (cr2)->cr_uid || \ 172 (cr1)->cr_uid == (cr2)->cr_uid) 173 174 static int sugid_coredump; 175 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 176 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 177 178 static int capmode_coredump; 179 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 180 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 181 182 static int do_coredump = 1; 183 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 184 &do_coredump, 0, "Enable/Disable coredumps"); 185 186 static int set_core_nodump_flag = 0; 187 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 188 0, "Enable setting the NODUMP flag on coredump files"); 189 190 static int coredump_devctl = 0; 191 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 192 0, "Generate a devctl notification when processes coredump"); 193 194 /* 195 * Signal properties and actions. 196 * The array below categorizes the signals and their default actions 197 * according to the following properties: 198 */ 199 #define SIGPROP_KILL 0x01 /* terminates process by default */ 200 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 201 #define SIGPROP_STOP 0x04 /* suspend process */ 202 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 203 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 204 #define SIGPROP_CONT 0x20 /* continue if suspended */ 205 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 206 207 static int sigproptbl[NSIG] = { 208 [SIGHUP] = SIGPROP_KILL, 209 [SIGINT] = SIGPROP_KILL, 210 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 211 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 212 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 213 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 214 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 215 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 216 [SIGKILL] = SIGPROP_KILL, 217 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 220 [SIGPIPE] = SIGPROP_KILL, 221 [SIGALRM] = SIGPROP_KILL, 222 [SIGTERM] = SIGPROP_KILL, 223 [SIGURG] = SIGPROP_IGNORE, 224 [SIGSTOP] = SIGPROP_STOP, 225 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 226 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 227 [SIGCHLD] = SIGPROP_IGNORE, 228 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 229 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 230 [SIGIO] = SIGPROP_IGNORE, 231 [SIGXCPU] = SIGPROP_KILL, 232 [SIGXFSZ] = SIGPROP_KILL, 233 [SIGVTALRM] = SIGPROP_KILL, 234 [SIGPROF] = SIGPROP_KILL, 235 [SIGWINCH] = SIGPROP_IGNORE, 236 [SIGINFO] = SIGPROP_IGNORE, 237 [SIGUSR1] = SIGPROP_KILL, 238 [SIGUSR2] = SIGPROP_KILL, 239 }; 240 241 sigset_t fastblock_mask; 242 243 static void 244 sigqueue_start(void) 245 { 246 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 247 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 248 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 249 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 250 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 251 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 252 SIGFILLSET(fastblock_mask); 253 SIG_CANTMASK(fastblock_mask); 254 } 255 256 ksiginfo_t * 257 ksiginfo_alloc(int wait) 258 { 259 int flags; 260 261 flags = M_ZERO; 262 if (! wait) 263 flags |= M_NOWAIT; 264 if (ksiginfo_zone != NULL) 265 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 266 return (NULL); 267 } 268 269 void 270 ksiginfo_free(ksiginfo_t *ksi) 271 { 272 uma_zfree(ksiginfo_zone, ksi); 273 } 274 275 static __inline int 276 ksiginfo_tryfree(ksiginfo_t *ksi) 277 { 278 if (!(ksi->ksi_flags & KSI_EXT)) { 279 uma_zfree(ksiginfo_zone, ksi); 280 return (1); 281 } 282 return (0); 283 } 284 285 void 286 sigqueue_init(sigqueue_t *list, struct proc *p) 287 { 288 SIGEMPTYSET(list->sq_signals); 289 SIGEMPTYSET(list->sq_kill); 290 SIGEMPTYSET(list->sq_ptrace); 291 TAILQ_INIT(&list->sq_list); 292 list->sq_proc = p; 293 list->sq_flags = SQ_INIT; 294 } 295 296 /* 297 * Get a signal's ksiginfo. 298 * Return: 299 * 0 - signal not found 300 * others - signal number 301 */ 302 static int 303 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 304 { 305 struct proc *p = sq->sq_proc; 306 struct ksiginfo *ksi, *next; 307 int count = 0; 308 309 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 310 311 if (!SIGISMEMBER(sq->sq_signals, signo)) 312 return (0); 313 314 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 315 count++; 316 SIGDELSET(sq->sq_ptrace, signo); 317 si->ksi_flags |= KSI_PTRACE; 318 } 319 if (SIGISMEMBER(sq->sq_kill, signo)) { 320 count++; 321 if (count == 1) 322 SIGDELSET(sq->sq_kill, signo); 323 } 324 325 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 326 if (ksi->ksi_signo == signo) { 327 if (count == 0) { 328 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 329 ksi->ksi_sigq = NULL; 330 ksiginfo_copy(ksi, si); 331 if (ksiginfo_tryfree(ksi) && p != NULL) 332 p->p_pendingcnt--; 333 } 334 if (++count > 1) 335 break; 336 } 337 } 338 339 if (count <= 1) 340 SIGDELSET(sq->sq_signals, signo); 341 si->ksi_signo = signo; 342 return (signo); 343 } 344 345 void 346 sigqueue_take(ksiginfo_t *ksi) 347 { 348 struct ksiginfo *kp; 349 struct proc *p; 350 sigqueue_t *sq; 351 352 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 353 return; 354 355 p = sq->sq_proc; 356 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 357 ksi->ksi_sigq = NULL; 358 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 359 p->p_pendingcnt--; 360 361 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 362 kp = TAILQ_NEXT(kp, ksi_link)) { 363 if (kp->ksi_signo == ksi->ksi_signo) 364 break; 365 } 366 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 367 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 368 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 369 } 370 371 static int 372 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 373 { 374 struct proc *p = sq->sq_proc; 375 struct ksiginfo *ksi; 376 int ret = 0; 377 378 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 379 380 /* 381 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 382 * for these signals. 383 */ 384 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 385 SIGADDSET(sq->sq_kill, signo); 386 goto out_set_bit; 387 } 388 389 /* directly insert the ksi, don't copy it */ 390 if (si->ksi_flags & KSI_INS) { 391 if (si->ksi_flags & KSI_HEAD) 392 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 393 else 394 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 395 si->ksi_sigq = sq; 396 goto out_set_bit; 397 } 398 399 if (__predict_false(ksiginfo_zone == NULL)) { 400 SIGADDSET(sq->sq_kill, signo); 401 goto out_set_bit; 402 } 403 404 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 405 signal_overflow++; 406 ret = EAGAIN; 407 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 408 signal_alloc_fail++; 409 ret = EAGAIN; 410 } else { 411 if (p != NULL) 412 p->p_pendingcnt++; 413 ksiginfo_copy(si, ksi); 414 ksi->ksi_signo = signo; 415 if (si->ksi_flags & KSI_HEAD) 416 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 417 else 418 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 419 ksi->ksi_sigq = sq; 420 } 421 422 if (ret != 0) { 423 if ((si->ksi_flags & KSI_PTRACE) != 0) { 424 SIGADDSET(sq->sq_ptrace, signo); 425 ret = 0; 426 goto out_set_bit; 427 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 428 (si->ksi_flags & KSI_SIGQ) == 0) { 429 SIGADDSET(sq->sq_kill, signo); 430 ret = 0; 431 goto out_set_bit; 432 } 433 return (ret); 434 } 435 436 out_set_bit: 437 SIGADDSET(sq->sq_signals, signo); 438 return (ret); 439 } 440 441 void 442 sigqueue_flush(sigqueue_t *sq) 443 { 444 struct proc *p = sq->sq_proc; 445 ksiginfo_t *ksi; 446 447 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 448 449 if (p != NULL) 450 PROC_LOCK_ASSERT(p, MA_OWNED); 451 452 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 453 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 454 ksi->ksi_sigq = NULL; 455 if (ksiginfo_tryfree(ksi) && p != NULL) 456 p->p_pendingcnt--; 457 } 458 459 SIGEMPTYSET(sq->sq_signals); 460 SIGEMPTYSET(sq->sq_kill); 461 SIGEMPTYSET(sq->sq_ptrace); 462 } 463 464 static void 465 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 466 { 467 sigset_t tmp; 468 struct proc *p1, *p2; 469 ksiginfo_t *ksi, *next; 470 471 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 472 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 473 p1 = src->sq_proc; 474 p2 = dst->sq_proc; 475 /* Move siginfo to target list */ 476 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 477 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 478 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 479 if (p1 != NULL) 480 p1->p_pendingcnt--; 481 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 482 ksi->ksi_sigq = dst; 483 if (p2 != NULL) 484 p2->p_pendingcnt++; 485 } 486 } 487 488 /* Move pending bits to target list */ 489 tmp = src->sq_kill; 490 SIGSETAND(tmp, *set); 491 SIGSETOR(dst->sq_kill, tmp); 492 SIGSETNAND(src->sq_kill, tmp); 493 494 tmp = src->sq_ptrace; 495 SIGSETAND(tmp, *set); 496 SIGSETOR(dst->sq_ptrace, tmp); 497 SIGSETNAND(src->sq_ptrace, tmp); 498 499 tmp = src->sq_signals; 500 SIGSETAND(tmp, *set); 501 SIGSETOR(dst->sq_signals, tmp); 502 SIGSETNAND(src->sq_signals, tmp); 503 } 504 505 #if 0 506 static void 507 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 508 { 509 sigset_t set; 510 511 SIGEMPTYSET(set); 512 SIGADDSET(set, signo); 513 sigqueue_move_set(src, dst, &set); 514 } 515 #endif 516 517 static void 518 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 519 { 520 struct proc *p = sq->sq_proc; 521 ksiginfo_t *ksi, *next; 522 523 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 524 525 /* Remove siginfo queue */ 526 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 527 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 528 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 529 ksi->ksi_sigq = NULL; 530 if (ksiginfo_tryfree(ksi) && p != NULL) 531 p->p_pendingcnt--; 532 } 533 } 534 SIGSETNAND(sq->sq_kill, *set); 535 SIGSETNAND(sq->sq_ptrace, *set); 536 SIGSETNAND(sq->sq_signals, *set); 537 } 538 539 void 540 sigqueue_delete(sigqueue_t *sq, int signo) 541 { 542 sigset_t set; 543 544 SIGEMPTYSET(set); 545 SIGADDSET(set, signo); 546 sigqueue_delete_set(sq, &set); 547 } 548 549 /* Remove a set of signals for a process */ 550 static void 551 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 552 { 553 sigqueue_t worklist; 554 struct thread *td0; 555 556 PROC_LOCK_ASSERT(p, MA_OWNED); 557 558 sigqueue_init(&worklist, NULL); 559 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 560 561 FOREACH_THREAD_IN_PROC(p, td0) 562 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 563 564 sigqueue_flush(&worklist); 565 } 566 567 void 568 sigqueue_delete_proc(struct proc *p, int signo) 569 { 570 sigset_t set; 571 572 SIGEMPTYSET(set); 573 SIGADDSET(set, signo); 574 sigqueue_delete_set_proc(p, &set); 575 } 576 577 static void 578 sigqueue_delete_stopmask_proc(struct proc *p) 579 { 580 sigset_t set; 581 582 SIGEMPTYSET(set); 583 SIGADDSET(set, SIGSTOP); 584 SIGADDSET(set, SIGTSTP); 585 SIGADDSET(set, SIGTTIN); 586 SIGADDSET(set, SIGTTOU); 587 sigqueue_delete_set_proc(p, &set); 588 } 589 590 /* 591 * Determine signal that should be delivered to thread td, the current 592 * thread, 0 if none. If there is a pending stop signal with default 593 * action, the process stops in issignal(). 594 */ 595 int 596 cursig(struct thread *td) 597 { 598 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 599 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 600 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 601 return (SIGPENDING(td) ? issignal(td) : 0); 602 } 603 604 /* 605 * Arrange for ast() to handle unmasked pending signals on return to user 606 * mode. This must be called whenever a signal is added to td_sigqueue or 607 * unmasked in td_sigmask. 608 */ 609 void 610 signotify(struct thread *td) 611 { 612 613 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 614 615 if (SIGPENDING(td)) { 616 thread_lock(td); 617 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 618 thread_unlock(td); 619 } 620 } 621 622 /* 623 * Returns 1 (true) if altstack is configured for the thread, and the 624 * passed stack bottom address falls into the altstack range. Handles 625 * the 43 compat special case where the alt stack size is zero. 626 */ 627 int 628 sigonstack(size_t sp) 629 { 630 struct thread *td; 631 632 td = curthread; 633 if ((td->td_pflags & TDP_ALTSTACK) == 0) 634 return (0); 635 #if defined(COMPAT_43) 636 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 637 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 638 #endif 639 return (sp >= (size_t)td->td_sigstk.ss_sp && 640 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 641 } 642 643 static __inline int 644 sigprop(int sig) 645 { 646 647 if (sig > 0 && sig < nitems(sigproptbl)) 648 return (sigproptbl[sig]); 649 return (0); 650 } 651 652 int 653 sig_ffs(sigset_t *set) 654 { 655 int i; 656 657 for (i = 0; i < _SIG_WORDS; i++) 658 if (set->__bits[i]) 659 return (ffs(set->__bits[i]) + (i * 32)); 660 return (0); 661 } 662 663 static bool 664 sigact_flag_test(const struct sigaction *act, int flag) 665 { 666 667 /* 668 * SA_SIGINFO is reset when signal disposition is set to 669 * ignore or default. Other flags are kept according to user 670 * settings. 671 */ 672 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 673 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 674 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 675 } 676 677 /* 678 * kern_sigaction 679 * sigaction 680 * freebsd4_sigaction 681 * osigaction 682 */ 683 int 684 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 685 struct sigaction *oact, int flags) 686 { 687 struct sigacts *ps; 688 struct proc *p = td->td_proc; 689 690 if (!_SIG_VALID(sig)) 691 return (EINVAL); 692 if (act != NULL && act->sa_handler != SIG_DFL && 693 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 694 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 695 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 696 return (EINVAL); 697 698 PROC_LOCK(p); 699 ps = p->p_sigacts; 700 mtx_lock(&ps->ps_mtx); 701 if (oact) { 702 memset(oact, 0, sizeof(*oact)); 703 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 704 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 705 oact->sa_flags |= SA_ONSTACK; 706 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 707 oact->sa_flags |= SA_RESTART; 708 if (SIGISMEMBER(ps->ps_sigreset, sig)) 709 oact->sa_flags |= SA_RESETHAND; 710 if (SIGISMEMBER(ps->ps_signodefer, sig)) 711 oact->sa_flags |= SA_NODEFER; 712 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 713 oact->sa_flags |= SA_SIGINFO; 714 oact->sa_sigaction = 715 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 716 } else 717 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 718 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 719 oact->sa_flags |= SA_NOCLDSTOP; 720 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 721 oact->sa_flags |= SA_NOCLDWAIT; 722 } 723 if (act) { 724 if ((sig == SIGKILL || sig == SIGSTOP) && 725 act->sa_handler != SIG_DFL) { 726 mtx_unlock(&ps->ps_mtx); 727 PROC_UNLOCK(p); 728 return (EINVAL); 729 } 730 731 /* 732 * Change setting atomically. 733 */ 734 735 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 736 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 737 if (sigact_flag_test(act, SA_SIGINFO)) { 738 ps->ps_sigact[_SIG_IDX(sig)] = 739 (__sighandler_t *)act->sa_sigaction; 740 SIGADDSET(ps->ps_siginfo, sig); 741 } else { 742 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 743 SIGDELSET(ps->ps_siginfo, sig); 744 } 745 if (!sigact_flag_test(act, SA_RESTART)) 746 SIGADDSET(ps->ps_sigintr, sig); 747 else 748 SIGDELSET(ps->ps_sigintr, sig); 749 if (sigact_flag_test(act, SA_ONSTACK)) 750 SIGADDSET(ps->ps_sigonstack, sig); 751 else 752 SIGDELSET(ps->ps_sigonstack, sig); 753 if (sigact_flag_test(act, SA_RESETHAND)) 754 SIGADDSET(ps->ps_sigreset, sig); 755 else 756 SIGDELSET(ps->ps_sigreset, sig); 757 if (sigact_flag_test(act, SA_NODEFER)) 758 SIGADDSET(ps->ps_signodefer, sig); 759 else 760 SIGDELSET(ps->ps_signodefer, sig); 761 if (sig == SIGCHLD) { 762 if (act->sa_flags & SA_NOCLDSTOP) 763 ps->ps_flag |= PS_NOCLDSTOP; 764 else 765 ps->ps_flag &= ~PS_NOCLDSTOP; 766 if (act->sa_flags & SA_NOCLDWAIT) { 767 /* 768 * Paranoia: since SA_NOCLDWAIT is implemented 769 * by reparenting the dying child to PID 1 (and 770 * trust it to reap the zombie), PID 1 itself 771 * is forbidden to set SA_NOCLDWAIT. 772 */ 773 if (p->p_pid == 1) 774 ps->ps_flag &= ~PS_NOCLDWAIT; 775 else 776 ps->ps_flag |= PS_NOCLDWAIT; 777 } else 778 ps->ps_flag &= ~PS_NOCLDWAIT; 779 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 780 ps->ps_flag |= PS_CLDSIGIGN; 781 else 782 ps->ps_flag &= ~PS_CLDSIGIGN; 783 } 784 /* 785 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 786 * and for signals set to SIG_DFL where the default is to 787 * ignore. However, don't put SIGCONT in ps_sigignore, as we 788 * have to restart the process. 789 */ 790 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 791 (sigprop(sig) & SIGPROP_IGNORE && 792 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 793 /* never to be seen again */ 794 sigqueue_delete_proc(p, sig); 795 if (sig != SIGCONT) 796 /* easier in psignal */ 797 SIGADDSET(ps->ps_sigignore, sig); 798 SIGDELSET(ps->ps_sigcatch, sig); 799 } else { 800 SIGDELSET(ps->ps_sigignore, sig); 801 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 802 SIGDELSET(ps->ps_sigcatch, sig); 803 else 804 SIGADDSET(ps->ps_sigcatch, sig); 805 } 806 #ifdef COMPAT_FREEBSD4 807 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 808 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 809 (flags & KSA_FREEBSD4) == 0) 810 SIGDELSET(ps->ps_freebsd4, sig); 811 else 812 SIGADDSET(ps->ps_freebsd4, sig); 813 #endif 814 #ifdef COMPAT_43 815 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 816 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 817 (flags & KSA_OSIGSET) == 0) 818 SIGDELSET(ps->ps_osigset, sig); 819 else 820 SIGADDSET(ps->ps_osigset, sig); 821 #endif 822 } 823 mtx_unlock(&ps->ps_mtx); 824 PROC_UNLOCK(p); 825 return (0); 826 } 827 828 #ifndef _SYS_SYSPROTO_H_ 829 struct sigaction_args { 830 int sig; 831 struct sigaction *act; 832 struct sigaction *oact; 833 }; 834 #endif 835 int 836 sys_sigaction(struct thread *td, struct sigaction_args *uap) 837 { 838 struct sigaction act, oact; 839 struct sigaction *actp, *oactp; 840 int error; 841 842 actp = (uap->act != NULL) ? &act : NULL; 843 oactp = (uap->oact != NULL) ? &oact : NULL; 844 if (actp) { 845 error = copyin(uap->act, actp, sizeof(act)); 846 if (error) 847 return (error); 848 } 849 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 850 if (oactp && !error) 851 error = copyout(oactp, uap->oact, sizeof(oact)); 852 return (error); 853 } 854 855 #ifdef COMPAT_FREEBSD4 856 #ifndef _SYS_SYSPROTO_H_ 857 struct freebsd4_sigaction_args { 858 int sig; 859 struct sigaction *act; 860 struct sigaction *oact; 861 }; 862 #endif 863 int 864 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 865 { 866 struct sigaction act, oact; 867 struct sigaction *actp, *oactp; 868 int error; 869 870 actp = (uap->act != NULL) ? &act : NULL; 871 oactp = (uap->oact != NULL) ? &oact : NULL; 872 if (actp) { 873 error = copyin(uap->act, actp, sizeof(act)); 874 if (error) 875 return (error); 876 } 877 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 878 if (oactp && !error) 879 error = copyout(oactp, uap->oact, sizeof(oact)); 880 return (error); 881 } 882 #endif /* COMAPT_FREEBSD4 */ 883 884 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 885 #ifndef _SYS_SYSPROTO_H_ 886 struct osigaction_args { 887 int signum; 888 struct osigaction *nsa; 889 struct osigaction *osa; 890 }; 891 #endif 892 int 893 osigaction(struct thread *td, struct osigaction_args *uap) 894 { 895 struct osigaction sa; 896 struct sigaction nsa, osa; 897 struct sigaction *nsap, *osap; 898 int error; 899 900 if (uap->signum <= 0 || uap->signum >= ONSIG) 901 return (EINVAL); 902 903 nsap = (uap->nsa != NULL) ? &nsa : NULL; 904 osap = (uap->osa != NULL) ? &osa : NULL; 905 906 if (nsap) { 907 error = copyin(uap->nsa, &sa, sizeof(sa)); 908 if (error) 909 return (error); 910 nsap->sa_handler = sa.sa_handler; 911 nsap->sa_flags = sa.sa_flags; 912 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 913 } 914 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 915 if (osap && !error) { 916 sa.sa_handler = osap->sa_handler; 917 sa.sa_flags = osap->sa_flags; 918 SIG2OSIG(osap->sa_mask, sa.sa_mask); 919 error = copyout(&sa, uap->osa, sizeof(sa)); 920 } 921 return (error); 922 } 923 924 #if !defined(__i386__) 925 /* Avoid replicating the same stub everywhere */ 926 int 927 osigreturn(struct thread *td, struct osigreturn_args *uap) 928 { 929 930 return (nosys(td, (struct nosys_args *)uap)); 931 } 932 #endif 933 #endif /* COMPAT_43 */ 934 935 /* 936 * Initialize signal state for process 0; 937 * set to ignore signals that are ignored by default. 938 */ 939 void 940 siginit(struct proc *p) 941 { 942 int i; 943 struct sigacts *ps; 944 945 PROC_LOCK(p); 946 ps = p->p_sigacts; 947 mtx_lock(&ps->ps_mtx); 948 for (i = 1; i <= NSIG; i++) { 949 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 950 SIGADDSET(ps->ps_sigignore, i); 951 } 952 } 953 mtx_unlock(&ps->ps_mtx); 954 PROC_UNLOCK(p); 955 } 956 957 /* 958 * Reset specified signal to the default disposition. 959 */ 960 static void 961 sigdflt(struct sigacts *ps, int sig) 962 { 963 964 mtx_assert(&ps->ps_mtx, MA_OWNED); 965 SIGDELSET(ps->ps_sigcatch, sig); 966 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 967 SIGADDSET(ps->ps_sigignore, sig); 968 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 969 SIGDELSET(ps->ps_siginfo, sig); 970 } 971 972 /* 973 * Reset signals for an exec of the specified process. 974 */ 975 void 976 execsigs(struct proc *p) 977 { 978 sigset_t osigignore; 979 struct sigacts *ps; 980 int sig; 981 struct thread *td; 982 983 /* 984 * Reset caught signals. Held signals remain held 985 * through td_sigmask (unless they were caught, 986 * and are now ignored by default). 987 */ 988 PROC_LOCK_ASSERT(p, MA_OWNED); 989 ps = p->p_sigacts; 990 mtx_lock(&ps->ps_mtx); 991 sig_drop_caught(p); 992 993 /* 994 * As CloudABI processes cannot modify signal handlers, fully 995 * reset all signals to their default behavior. Do ignore 996 * SIGPIPE, as it would otherwise be impossible to recover from 997 * writes to broken pipes and sockets. 998 */ 999 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1000 osigignore = ps->ps_sigignore; 1001 while (SIGNOTEMPTY(osigignore)) { 1002 sig = sig_ffs(&osigignore); 1003 SIGDELSET(osigignore, sig); 1004 if (sig != SIGPIPE) 1005 sigdflt(ps, sig); 1006 } 1007 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1008 } 1009 1010 /* 1011 * Reset stack state to the user stack. 1012 * Clear set of signals caught on the signal stack. 1013 */ 1014 td = curthread; 1015 MPASS(td->td_proc == p); 1016 td->td_sigstk.ss_flags = SS_DISABLE; 1017 td->td_sigstk.ss_size = 0; 1018 td->td_sigstk.ss_sp = 0; 1019 td->td_pflags &= ~TDP_ALTSTACK; 1020 /* 1021 * Reset no zombies if child dies flag as Solaris does. 1022 */ 1023 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1024 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1025 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1026 mtx_unlock(&ps->ps_mtx); 1027 } 1028 1029 /* 1030 * kern_sigprocmask() 1031 * 1032 * Manipulate signal mask. 1033 */ 1034 int 1035 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1036 int flags) 1037 { 1038 sigset_t new_block, oset1; 1039 struct proc *p; 1040 int error; 1041 1042 p = td->td_proc; 1043 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1044 PROC_LOCK_ASSERT(p, MA_OWNED); 1045 else 1046 PROC_LOCK(p); 1047 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1048 ? MA_OWNED : MA_NOTOWNED); 1049 if (oset != NULL) 1050 *oset = td->td_sigmask; 1051 1052 error = 0; 1053 if (set != NULL) { 1054 switch (how) { 1055 case SIG_BLOCK: 1056 SIG_CANTMASK(*set); 1057 oset1 = td->td_sigmask; 1058 SIGSETOR(td->td_sigmask, *set); 1059 new_block = td->td_sigmask; 1060 SIGSETNAND(new_block, oset1); 1061 break; 1062 case SIG_UNBLOCK: 1063 SIGSETNAND(td->td_sigmask, *set); 1064 signotify(td); 1065 goto out; 1066 case SIG_SETMASK: 1067 SIG_CANTMASK(*set); 1068 oset1 = td->td_sigmask; 1069 if (flags & SIGPROCMASK_OLD) 1070 SIGSETLO(td->td_sigmask, *set); 1071 else 1072 td->td_sigmask = *set; 1073 new_block = td->td_sigmask; 1074 SIGSETNAND(new_block, oset1); 1075 signotify(td); 1076 break; 1077 default: 1078 error = EINVAL; 1079 goto out; 1080 } 1081 1082 /* 1083 * The new_block set contains signals that were not previously 1084 * blocked, but are blocked now. 1085 * 1086 * In case we block any signal that was not previously blocked 1087 * for td, and process has the signal pending, try to schedule 1088 * signal delivery to some thread that does not block the 1089 * signal, possibly waking it up. 1090 */ 1091 if (p->p_numthreads != 1) 1092 reschedule_signals(p, new_block, flags); 1093 } 1094 1095 out: 1096 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1097 PROC_UNLOCK(p); 1098 return (error); 1099 } 1100 1101 #ifndef _SYS_SYSPROTO_H_ 1102 struct sigprocmask_args { 1103 int how; 1104 const sigset_t *set; 1105 sigset_t *oset; 1106 }; 1107 #endif 1108 int 1109 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1110 { 1111 sigset_t set, oset; 1112 sigset_t *setp, *osetp; 1113 int error; 1114 1115 setp = (uap->set != NULL) ? &set : NULL; 1116 osetp = (uap->oset != NULL) ? &oset : NULL; 1117 if (setp) { 1118 error = copyin(uap->set, setp, sizeof(set)); 1119 if (error) 1120 return (error); 1121 } 1122 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1123 if (osetp && !error) { 1124 error = copyout(osetp, uap->oset, sizeof(oset)); 1125 } 1126 return (error); 1127 } 1128 1129 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1130 #ifndef _SYS_SYSPROTO_H_ 1131 struct osigprocmask_args { 1132 int how; 1133 osigset_t mask; 1134 }; 1135 #endif 1136 int 1137 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1138 { 1139 sigset_t set, oset; 1140 int error; 1141 1142 OSIG2SIG(uap->mask, set); 1143 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1144 SIG2OSIG(oset, td->td_retval[0]); 1145 return (error); 1146 } 1147 #endif /* COMPAT_43 */ 1148 1149 int 1150 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1151 { 1152 ksiginfo_t ksi; 1153 sigset_t set; 1154 int error; 1155 1156 error = copyin(uap->set, &set, sizeof(set)); 1157 if (error) { 1158 td->td_retval[0] = error; 1159 return (0); 1160 } 1161 1162 error = kern_sigtimedwait(td, set, &ksi, NULL); 1163 if (error) { 1164 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1165 error = ERESTART; 1166 if (error == ERESTART) 1167 return (error); 1168 td->td_retval[0] = error; 1169 return (0); 1170 } 1171 1172 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1173 td->td_retval[0] = error; 1174 return (0); 1175 } 1176 1177 int 1178 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1179 { 1180 struct timespec ts; 1181 struct timespec *timeout; 1182 sigset_t set; 1183 ksiginfo_t ksi; 1184 int error; 1185 1186 if (uap->timeout) { 1187 error = copyin(uap->timeout, &ts, sizeof(ts)); 1188 if (error) 1189 return (error); 1190 1191 timeout = &ts; 1192 } else 1193 timeout = NULL; 1194 1195 error = copyin(uap->set, &set, sizeof(set)); 1196 if (error) 1197 return (error); 1198 1199 error = kern_sigtimedwait(td, set, &ksi, timeout); 1200 if (error) 1201 return (error); 1202 1203 if (uap->info) 1204 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1205 1206 if (error == 0) 1207 td->td_retval[0] = ksi.ksi_signo; 1208 return (error); 1209 } 1210 1211 int 1212 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1213 { 1214 ksiginfo_t ksi; 1215 sigset_t set; 1216 int error; 1217 1218 error = copyin(uap->set, &set, sizeof(set)); 1219 if (error) 1220 return (error); 1221 1222 error = kern_sigtimedwait(td, set, &ksi, NULL); 1223 if (error) 1224 return (error); 1225 1226 if (uap->info) 1227 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1228 1229 if (error == 0) 1230 td->td_retval[0] = ksi.ksi_signo; 1231 return (error); 1232 } 1233 1234 static void 1235 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1236 { 1237 struct thread *thr; 1238 1239 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1240 if (thr == td) 1241 thr->td_si = *si; 1242 else 1243 thr->td_si.si_signo = 0; 1244 } 1245 } 1246 1247 int 1248 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1249 struct timespec *timeout) 1250 { 1251 struct sigacts *ps; 1252 sigset_t saved_mask, new_block; 1253 struct proc *p; 1254 int error, sig, timo, timevalid = 0; 1255 struct timespec rts, ets, ts; 1256 struct timeval tv; 1257 bool traced; 1258 1259 p = td->td_proc; 1260 error = 0; 1261 ets.tv_sec = 0; 1262 ets.tv_nsec = 0; 1263 traced = false; 1264 1265 if (timeout != NULL) { 1266 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1267 timevalid = 1; 1268 getnanouptime(&rts); 1269 timespecadd(&rts, timeout, &ets); 1270 } 1271 } 1272 ksiginfo_init(ksi); 1273 /* Some signals can not be waited for. */ 1274 SIG_CANTMASK(waitset); 1275 ps = p->p_sigacts; 1276 PROC_LOCK(p); 1277 saved_mask = td->td_sigmask; 1278 SIGSETNAND(td->td_sigmask, waitset); 1279 for (;;) { 1280 mtx_lock(&ps->ps_mtx); 1281 sig = cursig(td); 1282 mtx_unlock(&ps->ps_mtx); 1283 KASSERT(sig >= 0, ("sig %d", sig)); 1284 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1285 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1286 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1287 error = 0; 1288 break; 1289 } 1290 } 1291 1292 if (error != 0) 1293 break; 1294 1295 /* 1296 * POSIX says this must be checked after looking for pending 1297 * signals. 1298 */ 1299 if (timeout != NULL) { 1300 if (!timevalid) { 1301 error = EINVAL; 1302 break; 1303 } 1304 getnanouptime(&rts); 1305 if (timespeccmp(&rts, &ets, >=)) { 1306 error = EAGAIN; 1307 break; 1308 } 1309 timespecsub(&ets, &rts, &ts); 1310 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1311 timo = tvtohz(&tv); 1312 } else { 1313 timo = 0; 1314 } 1315 1316 if (traced) { 1317 error = EINTR; 1318 break; 1319 } 1320 1321 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1322 1323 if (timeout != NULL) { 1324 if (error == ERESTART) { 1325 /* Timeout can not be restarted. */ 1326 error = EINTR; 1327 } else if (error == EAGAIN) { 1328 /* We will calculate timeout by ourself. */ 1329 error = 0; 1330 } 1331 } 1332 1333 /* 1334 * If PTRACE_SCE or PTRACE_SCX were set after 1335 * userspace entered the syscall, return spurious 1336 * EINTR after wait was done. Only do this as last 1337 * resort after rechecking for possible queued signals 1338 * and expired timeouts. 1339 */ 1340 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1341 traced = true; 1342 } 1343 1344 new_block = saved_mask; 1345 SIGSETNAND(new_block, td->td_sigmask); 1346 td->td_sigmask = saved_mask; 1347 /* 1348 * Fewer signals can be delivered to us, reschedule signal 1349 * notification. 1350 */ 1351 if (p->p_numthreads != 1) 1352 reschedule_signals(p, new_block, 0); 1353 1354 if (error == 0) { 1355 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1356 1357 if (ksi->ksi_code == SI_TIMER) 1358 itimer_accept(p, ksi->ksi_timerid, ksi); 1359 1360 #ifdef KTRACE 1361 if (KTRPOINT(td, KTR_PSIG)) { 1362 sig_t action; 1363 1364 mtx_lock(&ps->ps_mtx); 1365 action = ps->ps_sigact[_SIG_IDX(sig)]; 1366 mtx_unlock(&ps->ps_mtx); 1367 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1368 } 1369 #endif 1370 if (sig == SIGKILL) { 1371 proc_td_siginfo_capture(td, &ksi->ksi_info); 1372 sigexit(td, sig); 1373 } 1374 } 1375 PROC_UNLOCK(p); 1376 return (error); 1377 } 1378 1379 #ifndef _SYS_SYSPROTO_H_ 1380 struct sigpending_args { 1381 sigset_t *set; 1382 }; 1383 #endif 1384 int 1385 sys_sigpending(struct thread *td, struct sigpending_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 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1395 } 1396 1397 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1398 #ifndef _SYS_SYSPROTO_H_ 1399 struct osigpending_args { 1400 int dummy; 1401 }; 1402 #endif 1403 int 1404 osigpending(struct thread *td, struct osigpending_args *uap) 1405 { 1406 struct proc *p = td->td_proc; 1407 sigset_t pending; 1408 1409 PROC_LOCK(p); 1410 pending = p->p_sigqueue.sq_signals; 1411 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1412 PROC_UNLOCK(p); 1413 SIG2OSIG(pending, td->td_retval[0]); 1414 return (0); 1415 } 1416 #endif /* COMPAT_43 */ 1417 1418 #if defined(COMPAT_43) 1419 /* 1420 * Generalized interface signal handler, 4.3-compatible. 1421 */ 1422 #ifndef _SYS_SYSPROTO_H_ 1423 struct osigvec_args { 1424 int signum; 1425 struct sigvec *nsv; 1426 struct sigvec *osv; 1427 }; 1428 #endif 1429 /* ARGSUSED */ 1430 int 1431 osigvec(struct thread *td, struct osigvec_args *uap) 1432 { 1433 struct sigvec vec; 1434 struct sigaction nsa, osa; 1435 struct sigaction *nsap, *osap; 1436 int error; 1437 1438 if (uap->signum <= 0 || uap->signum >= ONSIG) 1439 return (EINVAL); 1440 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1441 osap = (uap->osv != NULL) ? &osa : NULL; 1442 if (nsap) { 1443 error = copyin(uap->nsv, &vec, sizeof(vec)); 1444 if (error) 1445 return (error); 1446 nsap->sa_handler = vec.sv_handler; 1447 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1448 nsap->sa_flags = vec.sv_flags; 1449 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1450 } 1451 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1452 if (osap && !error) { 1453 vec.sv_handler = osap->sa_handler; 1454 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1455 vec.sv_flags = osap->sa_flags; 1456 vec.sv_flags &= ~SA_NOCLDWAIT; 1457 vec.sv_flags ^= SA_RESTART; 1458 error = copyout(&vec, uap->osv, sizeof(vec)); 1459 } 1460 return (error); 1461 } 1462 1463 #ifndef _SYS_SYSPROTO_H_ 1464 struct osigblock_args { 1465 int mask; 1466 }; 1467 #endif 1468 int 1469 osigblock(struct thread *td, struct osigblock_args *uap) 1470 { 1471 sigset_t set, oset; 1472 1473 OSIG2SIG(uap->mask, set); 1474 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1475 SIG2OSIG(oset, td->td_retval[0]); 1476 return (0); 1477 } 1478 1479 #ifndef _SYS_SYSPROTO_H_ 1480 struct osigsetmask_args { 1481 int mask; 1482 }; 1483 #endif 1484 int 1485 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1486 { 1487 sigset_t set, oset; 1488 1489 OSIG2SIG(uap->mask, set); 1490 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1491 SIG2OSIG(oset, td->td_retval[0]); 1492 return (0); 1493 } 1494 #endif /* COMPAT_43 */ 1495 1496 /* 1497 * Suspend calling thread until signal, providing mask to be set in the 1498 * meantime. 1499 */ 1500 #ifndef _SYS_SYSPROTO_H_ 1501 struct sigsuspend_args { 1502 const sigset_t *sigmask; 1503 }; 1504 #endif 1505 /* ARGSUSED */ 1506 int 1507 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1508 { 1509 sigset_t mask; 1510 int error; 1511 1512 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1513 if (error) 1514 return (error); 1515 return (kern_sigsuspend(td, mask)); 1516 } 1517 1518 int 1519 kern_sigsuspend(struct thread *td, sigset_t mask) 1520 { 1521 struct proc *p = td->td_proc; 1522 int has_sig, sig; 1523 1524 /* 1525 * When returning from sigsuspend, we want 1526 * the old mask to be restored after the 1527 * signal handler has finished. Thus, we 1528 * save it here and mark the sigacts structure 1529 * to indicate this. 1530 */ 1531 PROC_LOCK(p); 1532 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1533 SIGPROCMASK_PROC_LOCKED); 1534 td->td_pflags |= TDP_OLDMASK; 1535 1536 /* 1537 * Process signals now. Otherwise, we can get spurious wakeup 1538 * due to signal entered process queue, but delivered to other 1539 * thread. But sigsuspend should return only on signal 1540 * delivery. 1541 */ 1542 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1543 for (has_sig = 0; !has_sig;) { 1544 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1545 0) == 0) 1546 /* void */; 1547 thread_suspend_check(0); 1548 mtx_lock(&p->p_sigacts->ps_mtx); 1549 while ((sig = cursig(td)) != 0) { 1550 KASSERT(sig >= 0, ("sig %d", sig)); 1551 has_sig += postsig(sig); 1552 } 1553 mtx_unlock(&p->p_sigacts->ps_mtx); 1554 1555 /* 1556 * If PTRACE_SCE or PTRACE_SCX were set after 1557 * userspace entered the syscall, return spurious 1558 * EINTR. 1559 */ 1560 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1561 has_sig += 1; 1562 } 1563 PROC_UNLOCK(p); 1564 td->td_errno = EINTR; 1565 td->td_pflags |= TDP_NERRNO; 1566 return (EJUSTRETURN); 1567 } 1568 1569 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1570 /* 1571 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1572 * convention: libc stub passes mask, not pointer, to save a copyin. 1573 */ 1574 #ifndef _SYS_SYSPROTO_H_ 1575 struct osigsuspend_args { 1576 osigset_t mask; 1577 }; 1578 #endif 1579 /* ARGSUSED */ 1580 int 1581 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1582 { 1583 sigset_t mask; 1584 1585 OSIG2SIG(uap->mask, mask); 1586 return (kern_sigsuspend(td, mask)); 1587 } 1588 #endif /* COMPAT_43 */ 1589 1590 #if defined(COMPAT_43) 1591 #ifndef _SYS_SYSPROTO_H_ 1592 struct osigstack_args { 1593 struct sigstack *nss; 1594 struct sigstack *oss; 1595 }; 1596 #endif 1597 /* ARGSUSED */ 1598 int 1599 osigstack(struct thread *td, struct osigstack_args *uap) 1600 { 1601 struct sigstack nss, oss; 1602 int error = 0; 1603 1604 if (uap->nss != NULL) { 1605 error = copyin(uap->nss, &nss, sizeof(nss)); 1606 if (error) 1607 return (error); 1608 } 1609 oss.ss_sp = td->td_sigstk.ss_sp; 1610 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1611 if (uap->nss != NULL) { 1612 td->td_sigstk.ss_sp = nss.ss_sp; 1613 td->td_sigstk.ss_size = 0; 1614 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1615 td->td_pflags |= TDP_ALTSTACK; 1616 } 1617 if (uap->oss != NULL) 1618 error = copyout(&oss, uap->oss, sizeof(oss)); 1619 1620 return (error); 1621 } 1622 #endif /* COMPAT_43 */ 1623 1624 #ifndef _SYS_SYSPROTO_H_ 1625 struct sigaltstack_args { 1626 stack_t *ss; 1627 stack_t *oss; 1628 }; 1629 #endif 1630 /* ARGSUSED */ 1631 int 1632 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1633 { 1634 stack_t ss, oss; 1635 int error; 1636 1637 if (uap->ss != NULL) { 1638 error = copyin(uap->ss, &ss, sizeof(ss)); 1639 if (error) 1640 return (error); 1641 } 1642 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1643 (uap->oss != NULL) ? &oss : NULL); 1644 if (error) 1645 return (error); 1646 if (uap->oss != NULL) 1647 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1648 return (error); 1649 } 1650 1651 int 1652 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1653 { 1654 struct proc *p = td->td_proc; 1655 int oonstack; 1656 1657 oonstack = sigonstack(cpu_getstack(td)); 1658 1659 if (oss != NULL) { 1660 *oss = td->td_sigstk; 1661 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1662 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1663 } 1664 1665 if (ss != NULL) { 1666 if (oonstack) 1667 return (EPERM); 1668 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1669 return (EINVAL); 1670 if (!(ss->ss_flags & SS_DISABLE)) { 1671 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1672 return (ENOMEM); 1673 1674 td->td_sigstk = *ss; 1675 td->td_pflags |= TDP_ALTSTACK; 1676 } else { 1677 td->td_pflags &= ~TDP_ALTSTACK; 1678 } 1679 } 1680 return (0); 1681 } 1682 1683 struct killpg1_ctx { 1684 struct thread *td; 1685 ksiginfo_t *ksi; 1686 int sig; 1687 bool sent; 1688 bool found; 1689 int ret; 1690 }; 1691 1692 static void 1693 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1694 { 1695 int err; 1696 1697 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1698 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1699 return; 1700 PROC_LOCK(p); 1701 err = p_cansignal(arg->td, p, arg->sig); 1702 if (err == 0 && arg->sig != 0) 1703 pksignal(p, arg->sig, arg->ksi); 1704 PROC_UNLOCK(p); 1705 if (err != ESRCH) 1706 arg->found = true; 1707 if (err == 0) 1708 arg->sent = true; 1709 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1710 arg->ret = err; 1711 } 1712 1713 /* 1714 * Common code for kill process group/broadcast kill. 1715 * cp is calling process. 1716 */ 1717 static int 1718 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1719 { 1720 struct proc *p; 1721 struct pgrp *pgrp; 1722 struct killpg1_ctx arg; 1723 1724 arg.td = td; 1725 arg.ksi = ksi; 1726 arg.sig = sig; 1727 arg.sent = false; 1728 arg.found = false; 1729 arg.ret = 0; 1730 if (all) { 1731 /* 1732 * broadcast 1733 */ 1734 sx_slock(&allproc_lock); 1735 FOREACH_PROC_IN_SYSTEM(p) { 1736 killpg1_sendsig(p, true, &arg); 1737 } 1738 sx_sunlock(&allproc_lock); 1739 } else { 1740 sx_slock(&proctree_lock); 1741 if (pgid == 0) { 1742 /* 1743 * zero pgid means send to my process group. 1744 */ 1745 pgrp = td->td_proc->p_pgrp; 1746 PGRP_LOCK(pgrp); 1747 } else { 1748 pgrp = pgfind(pgid); 1749 if (pgrp == NULL) { 1750 sx_sunlock(&proctree_lock); 1751 return (ESRCH); 1752 } 1753 } 1754 sx_sunlock(&proctree_lock); 1755 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1756 killpg1_sendsig(p, false, &arg); 1757 } 1758 PGRP_UNLOCK(pgrp); 1759 } 1760 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1761 if (arg.ret == 0 && !arg.sent) 1762 arg.ret = arg.found ? EPERM : ESRCH; 1763 return (arg.ret); 1764 } 1765 1766 #ifndef _SYS_SYSPROTO_H_ 1767 struct kill_args { 1768 int pid; 1769 int signum; 1770 }; 1771 #endif 1772 /* ARGSUSED */ 1773 int 1774 sys_kill(struct thread *td, struct kill_args *uap) 1775 { 1776 1777 return (kern_kill(td, uap->pid, uap->signum)); 1778 } 1779 1780 int 1781 kern_kill(struct thread *td, pid_t pid, int signum) 1782 { 1783 ksiginfo_t ksi; 1784 struct proc *p; 1785 int error; 1786 1787 /* 1788 * A process in capability mode can send signals only to himself. 1789 * The main rationale behind this is that abort(3) is implemented as 1790 * kill(getpid(), SIGABRT). 1791 */ 1792 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1793 return (ECAPMODE); 1794 1795 AUDIT_ARG_SIGNUM(signum); 1796 AUDIT_ARG_PID(pid); 1797 if ((u_int)signum > _SIG_MAXSIG) 1798 return (EINVAL); 1799 1800 ksiginfo_init(&ksi); 1801 ksi.ksi_signo = signum; 1802 ksi.ksi_code = SI_USER; 1803 ksi.ksi_pid = td->td_proc->p_pid; 1804 ksi.ksi_uid = td->td_ucred->cr_ruid; 1805 1806 if (pid > 0) { 1807 /* kill single process */ 1808 if ((p = pfind_any(pid)) == NULL) 1809 return (ESRCH); 1810 AUDIT_ARG_PROCESS(p); 1811 error = p_cansignal(td, p, signum); 1812 if (error == 0 && signum) 1813 pksignal(p, signum, &ksi); 1814 PROC_UNLOCK(p); 1815 return (error); 1816 } 1817 switch (pid) { 1818 case -1: /* broadcast signal */ 1819 return (killpg1(td, signum, 0, 1, &ksi)); 1820 case 0: /* signal own process group */ 1821 return (killpg1(td, signum, 0, 0, &ksi)); 1822 default: /* negative explicit process group */ 1823 return (killpg1(td, signum, -pid, 0, &ksi)); 1824 } 1825 /* NOTREACHED */ 1826 } 1827 1828 int 1829 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1830 { 1831 struct proc *p; 1832 int error; 1833 1834 AUDIT_ARG_SIGNUM(uap->signum); 1835 AUDIT_ARG_FD(uap->fd); 1836 if ((u_int)uap->signum > _SIG_MAXSIG) 1837 return (EINVAL); 1838 1839 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1840 if (error) 1841 return (error); 1842 AUDIT_ARG_PROCESS(p); 1843 error = p_cansignal(td, p, uap->signum); 1844 if (error == 0 && uap->signum) 1845 kern_psignal(p, uap->signum); 1846 PROC_UNLOCK(p); 1847 return (error); 1848 } 1849 1850 #if defined(COMPAT_43) 1851 #ifndef _SYS_SYSPROTO_H_ 1852 struct okillpg_args { 1853 int pgid; 1854 int signum; 1855 }; 1856 #endif 1857 /* ARGSUSED */ 1858 int 1859 okillpg(struct thread *td, struct okillpg_args *uap) 1860 { 1861 ksiginfo_t ksi; 1862 1863 AUDIT_ARG_SIGNUM(uap->signum); 1864 AUDIT_ARG_PID(uap->pgid); 1865 if ((u_int)uap->signum > _SIG_MAXSIG) 1866 return (EINVAL); 1867 1868 ksiginfo_init(&ksi); 1869 ksi.ksi_signo = uap->signum; 1870 ksi.ksi_code = SI_USER; 1871 ksi.ksi_pid = td->td_proc->p_pid; 1872 ksi.ksi_uid = td->td_ucred->cr_ruid; 1873 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1874 } 1875 #endif /* COMPAT_43 */ 1876 1877 #ifndef _SYS_SYSPROTO_H_ 1878 struct sigqueue_args { 1879 pid_t pid; 1880 int signum; 1881 /* union sigval */ void *value; 1882 }; 1883 #endif 1884 int 1885 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1886 { 1887 union sigval sv; 1888 1889 sv.sival_ptr = uap->value; 1890 1891 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1892 } 1893 1894 int 1895 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1896 { 1897 ksiginfo_t ksi; 1898 struct proc *p; 1899 int error; 1900 1901 if ((u_int)signum > _SIG_MAXSIG) 1902 return (EINVAL); 1903 1904 /* 1905 * Specification says sigqueue can only send signal to 1906 * single process. 1907 */ 1908 if (pid <= 0) 1909 return (EINVAL); 1910 1911 if ((p = pfind_any(pid)) == NULL) 1912 return (ESRCH); 1913 error = p_cansignal(td, p, signum); 1914 if (error == 0 && signum != 0) { 1915 ksiginfo_init(&ksi); 1916 ksi.ksi_flags = KSI_SIGQ; 1917 ksi.ksi_signo = signum; 1918 ksi.ksi_code = SI_QUEUE; 1919 ksi.ksi_pid = td->td_proc->p_pid; 1920 ksi.ksi_uid = td->td_ucred->cr_ruid; 1921 ksi.ksi_value = *value; 1922 error = pksignal(p, ksi.ksi_signo, &ksi); 1923 } 1924 PROC_UNLOCK(p); 1925 return (error); 1926 } 1927 1928 /* 1929 * Send a signal to a process group. 1930 */ 1931 void 1932 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1933 { 1934 struct pgrp *pgrp; 1935 1936 if (pgid != 0) { 1937 sx_slock(&proctree_lock); 1938 pgrp = pgfind(pgid); 1939 sx_sunlock(&proctree_lock); 1940 if (pgrp != NULL) { 1941 pgsignal(pgrp, sig, 0, ksi); 1942 PGRP_UNLOCK(pgrp); 1943 } 1944 } 1945 } 1946 1947 /* 1948 * Send a signal to a process group. If checktty is 1, 1949 * limit to members which have a controlling terminal. 1950 */ 1951 void 1952 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1953 { 1954 struct proc *p; 1955 1956 if (pgrp) { 1957 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1958 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1959 PROC_LOCK(p); 1960 if (p->p_state == PRS_NORMAL && 1961 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1962 pksignal(p, sig, ksi); 1963 PROC_UNLOCK(p); 1964 } 1965 } 1966 } 1967 1968 /* 1969 * Recalculate the signal mask and reset the signal disposition after 1970 * usermode frame for delivery is formed. Should be called after 1971 * mach-specific routine, because sysent->sv_sendsig() needs correct 1972 * ps_siginfo and signal mask. 1973 */ 1974 static void 1975 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1976 { 1977 sigset_t mask; 1978 1979 mtx_assert(&ps->ps_mtx, MA_OWNED); 1980 td->td_ru.ru_nsignals++; 1981 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1982 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1983 SIGADDSET(mask, sig); 1984 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1985 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1986 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1987 sigdflt(ps, sig); 1988 } 1989 1990 /* 1991 * Send a signal caused by a trap to the current thread. If it will be 1992 * caught immediately, deliver it with correct code. Otherwise, post it 1993 * normally. 1994 */ 1995 void 1996 trapsignal(struct thread *td, ksiginfo_t *ksi) 1997 { 1998 struct sigacts *ps; 1999 struct proc *p; 2000 sigset_t sigmask; 2001 int code, sig; 2002 2003 p = td->td_proc; 2004 sig = ksi->ksi_signo; 2005 code = ksi->ksi_code; 2006 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2007 2008 PROC_LOCK(p); 2009 ps = p->p_sigacts; 2010 mtx_lock(&ps->ps_mtx); 2011 sigmask = td->td_sigmask; 2012 if (td->td_sigblock_val != 0) 2013 SIGSETOR(sigmask, fastblock_mask); 2014 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2015 !SIGISMEMBER(sigmask, sig)) { 2016 #ifdef KTRACE 2017 if (KTRPOINT(curthread, KTR_PSIG)) 2018 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2019 &td->td_sigmask, code); 2020 #endif 2021 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2022 ksi, &td->td_sigmask); 2023 postsig_done(sig, td, ps); 2024 mtx_unlock(&ps->ps_mtx); 2025 } else { 2026 /* 2027 * Avoid a possible infinite loop if the thread 2028 * masking the signal or process is ignoring the 2029 * signal. 2030 */ 2031 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2032 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2033 SIGDELSET(td->td_sigmask, sig); 2034 SIGDELSET(ps->ps_sigcatch, sig); 2035 SIGDELSET(ps->ps_sigignore, sig); 2036 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2037 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2038 td->td_sigblock_val = 0; 2039 } 2040 mtx_unlock(&ps->ps_mtx); 2041 p->p_sig = sig; /* XXX to verify code */ 2042 tdsendsignal(p, td, sig, ksi); 2043 } 2044 PROC_UNLOCK(p); 2045 } 2046 2047 static struct thread * 2048 sigtd(struct proc *p, int sig, bool fast_sigblock) 2049 { 2050 struct thread *td, *signal_td; 2051 2052 PROC_LOCK_ASSERT(p, MA_OWNED); 2053 MPASS(!fast_sigblock || p == curproc); 2054 2055 /* 2056 * Check if current thread can handle the signal without 2057 * switching context to another thread. 2058 */ 2059 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2060 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2061 return (curthread); 2062 signal_td = NULL; 2063 FOREACH_THREAD_IN_PROC(p, td) { 2064 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2065 td != curthread || td->td_sigblock_val == 0)) { 2066 signal_td = td; 2067 break; 2068 } 2069 } 2070 if (signal_td == NULL) 2071 signal_td = FIRST_THREAD_IN_PROC(p); 2072 return (signal_td); 2073 } 2074 2075 /* 2076 * Send the signal to the process. If the signal has an action, the action 2077 * is usually performed by the target process rather than the caller; we add 2078 * the signal to the set of pending signals for the process. 2079 * 2080 * Exceptions: 2081 * o When a stop signal is sent to a sleeping process that takes the 2082 * default action, the process is stopped without awakening it. 2083 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2084 * regardless of the signal action (eg, blocked or ignored). 2085 * 2086 * Other ignored signals are discarded immediately. 2087 * 2088 * NB: This function may be entered from the debugger via the "kill" DDB 2089 * command. There is little that can be done to mitigate the possibly messy 2090 * side effects of this unwise possibility. 2091 */ 2092 void 2093 kern_psignal(struct proc *p, int sig) 2094 { 2095 ksiginfo_t ksi; 2096 2097 ksiginfo_init(&ksi); 2098 ksi.ksi_signo = sig; 2099 ksi.ksi_code = SI_KERNEL; 2100 (void) tdsendsignal(p, NULL, sig, &ksi); 2101 } 2102 2103 int 2104 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2105 { 2106 2107 return (tdsendsignal(p, NULL, sig, ksi)); 2108 } 2109 2110 /* Utility function for finding a thread to send signal event to. */ 2111 int 2112 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2113 { 2114 struct thread *td; 2115 2116 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2117 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2118 if (td == NULL) 2119 return (ESRCH); 2120 *ttd = td; 2121 } else { 2122 *ttd = NULL; 2123 PROC_LOCK(p); 2124 } 2125 return (0); 2126 } 2127 2128 void 2129 tdsignal(struct thread *td, int sig) 2130 { 2131 ksiginfo_t ksi; 2132 2133 ksiginfo_init(&ksi); 2134 ksi.ksi_signo = sig; 2135 ksi.ksi_code = SI_KERNEL; 2136 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2137 } 2138 2139 void 2140 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2141 { 2142 2143 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2144 } 2145 2146 int 2147 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2148 { 2149 sig_t action; 2150 sigqueue_t *sigqueue; 2151 int prop; 2152 struct sigacts *ps; 2153 int intrval; 2154 int ret = 0; 2155 int wakeup_swapper; 2156 2157 MPASS(td == NULL || p == td->td_proc); 2158 PROC_LOCK_ASSERT(p, MA_OWNED); 2159 2160 if (!_SIG_VALID(sig)) 2161 panic("%s(): invalid signal %d", __func__, sig); 2162 2163 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2164 2165 /* 2166 * IEEE Std 1003.1-2001: return success when killing a zombie. 2167 */ 2168 if (p->p_state == PRS_ZOMBIE) { 2169 if (ksi && (ksi->ksi_flags & KSI_INS)) 2170 ksiginfo_tryfree(ksi); 2171 return (ret); 2172 } 2173 2174 ps = p->p_sigacts; 2175 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2176 prop = sigprop(sig); 2177 2178 if (td == NULL) { 2179 td = sigtd(p, sig, false); 2180 sigqueue = &p->p_sigqueue; 2181 } else 2182 sigqueue = &td->td_sigqueue; 2183 2184 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2185 2186 /* 2187 * If the signal is being ignored, 2188 * then we forget about it immediately. 2189 * (Note: we don't set SIGCONT in ps_sigignore, 2190 * and if it is set to SIG_IGN, 2191 * action will be SIG_DFL here.) 2192 */ 2193 mtx_lock(&ps->ps_mtx); 2194 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2195 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2196 2197 mtx_unlock(&ps->ps_mtx); 2198 if (ksi && (ksi->ksi_flags & KSI_INS)) 2199 ksiginfo_tryfree(ksi); 2200 return (ret); 2201 } 2202 if (SIGISMEMBER(td->td_sigmask, sig)) 2203 action = SIG_HOLD; 2204 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2205 action = SIG_CATCH; 2206 else 2207 action = SIG_DFL; 2208 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2209 intrval = EINTR; 2210 else 2211 intrval = ERESTART; 2212 mtx_unlock(&ps->ps_mtx); 2213 2214 if (prop & SIGPROP_CONT) 2215 sigqueue_delete_stopmask_proc(p); 2216 else if (prop & SIGPROP_STOP) { 2217 /* 2218 * If sending a tty stop signal to a member of an orphaned 2219 * process group, discard the signal here if the action 2220 * is default; don't stop the process below if sleeping, 2221 * and don't clear any pending SIGCONT. 2222 */ 2223 if ((prop & SIGPROP_TTYSTOP) && 2224 (p->p_pgrp->pg_jobc == 0) && 2225 (action == SIG_DFL)) { 2226 if (ksi && (ksi->ksi_flags & KSI_INS)) 2227 ksiginfo_tryfree(ksi); 2228 return (ret); 2229 } 2230 sigqueue_delete_proc(p, SIGCONT); 2231 if (p->p_flag & P_CONTINUED) { 2232 p->p_flag &= ~P_CONTINUED; 2233 PROC_LOCK(p->p_pptr); 2234 sigqueue_take(p->p_ksi); 2235 PROC_UNLOCK(p->p_pptr); 2236 } 2237 } 2238 2239 ret = sigqueue_add(sigqueue, sig, ksi); 2240 if (ret != 0) 2241 return (ret); 2242 signotify(td); 2243 /* 2244 * Defer further processing for signals which are held, 2245 * except that stopped processes must be continued by SIGCONT. 2246 */ 2247 if (action == SIG_HOLD && 2248 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2249 return (ret); 2250 2251 /* SIGKILL: Remove procfs STOPEVENTs. */ 2252 if (sig == SIGKILL) { 2253 /* from procfs_ioctl.c: PIOCBIC */ 2254 p->p_stops = 0; 2255 /* from procfs_ioctl.c: PIOCCONT */ 2256 p->p_step = 0; 2257 wakeup(&p->p_step); 2258 } 2259 wakeup_swapper = 0; 2260 2261 /* 2262 * Some signals have a process-wide effect and a per-thread 2263 * component. Most processing occurs when the process next 2264 * tries to cross the user boundary, however there are some 2265 * times when processing needs to be done immediately, such as 2266 * waking up threads so that they can cross the user boundary. 2267 * We try to do the per-process part here. 2268 */ 2269 if (P_SHOULDSTOP(p)) { 2270 KASSERT(!(p->p_flag & P_WEXIT), 2271 ("signal to stopped but exiting process")); 2272 if (sig == SIGKILL) { 2273 /* 2274 * If traced process is already stopped, 2275 * then no further action is necessary. 2276 */ 2277 if (p->p_flag & P_TRACED) 2278 goto out; 2279 /* 2280 * SIGKILL sets process running. 2281 * It will die elsewhere. 2282 * All threads must be restarted. 2283 */ 2284 p->p_flag &= ~P_STOPPED_SIG; 2285 goto runfast; 2286 } 2287 2288 if (prop & SIGPROP_CONT) { 2289 /* 2290 * If traced process is already stopped, 2291 * then no further action is necessary. 2292 */ 2293 if (p->p_flag & P_TRACED) 2294 goto out; 2295 /* 2296 * If SIGCONT is default (or ignored), we continue the 2297 * process but don't leave the signal in sigqueue as 2298 * it has no further action. If SIGCONT is held, we 2299 * continue the process and leave the signal in 2300 * sigqueue. If the process catches SIGCONT, let it 2301 * handle the signal itself. If it isn't waiting on 2302 * an event, it goes back to run state. 2303 * Otherwise, process goes back to sleep state. 2304 */ 2305 p->p_flag &= ~P_STOPPED_SIG; 2306 PROC_SLOCK(p); 2307 if (p->p_numthreads == p->p_suspcount) { 2308 PROC_SUNLOCK(p); 2309 p->p_flag |= P_CONTINUED; 2310 p->p_xsig = SIGCONT; 2311 PROC_LOCK(p->p_pptr); 2312 childproc_continued(p); 2313 PROC_UNLOCK(p->p_pptr); 2314 PROC_SLOCK(p); 2315 } 2316 if (action == SIG_DFL) { 2317 thread_unsuspend(p); 2318 PROC_SUNLOCK(p); 2319 sigqueue_delete(sigqueue, sig); 2320 goto out; 2321 } 2322 if (action == SIG_CATCH) { 2323 /* 2324 * The process wants to catch it so it needs 2325 * to run at least one thread, but which one? 2326 */ 2327 PROC_SUNLOCK(p); 2328 goto runfast; 2329 } 2330 /* 2331 * The signal is not ignored or caught. 2332 */ 2333 thread_unsuspend(p); 2334 PROC_SUNLOCK(p); 2335 goto out; 2336 } 2337 2338 if (prop & SIGPROP_STOP) { 2339 /* 2340 * If traced process is already stopped, 2341 * then no further action is necessary. 2342 */ 2343 if (p->p_flag & P_TRACED) 2344 goto out; 2345 /* 2346 * Already stopped, don't need to stop again 2347 * (If we did the shell could get confused). 2348 * Just make sure the signal STOP bit set. 2349 */ 2350 p->p_flag |= P_STOPPED_SIG; 2351 sigqueue_delete(sigqueue, sig); 2352 goto out; 2353 } 2354 2355 /* 2356 * All other kinds of signals: 2357 * If a thread is sleeping interruptibly, simulate a 2358 * wakeup so that when it is continued it will be made 2359 * runnable and can look at the signal. However, don't make 2360 * the PROCESS runnable, leave it stopped. 2361 * It may run a bit until it hits a thread_suspend_check(). 2362 */ 2363 PROC_SLOCK(p); 2364 thread_lock(td); 2365 if (TD_CAN_ABORT(td)) 2366 wakeup_swapper = sleepq_abort(td, intrval); 2367 else 2368 thread_unlock(td); 2369 PROC_SUNLOCK(p); 2370 goto out; 2371 /* 2372 * Mutexes are short lived. Threads waiting on them will 2373 * hit thread_suspend_check() soon. 2374 */ 2375 } else if (p->p_state == PRS_NORMAL) { 2376 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2377 tdsigwakeup(td, sig, action, intrval); 2378 goto out; 2379 } 2380 2381 MPASS(action == SIG_DFL); 2382 2383 if (prop & SIGPROP_STOP) { 2384 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2385 goto out; 2386 p->p_flag |= P_STOPPED_SIG; 2387 p->p_xsig = sig; 2388 PROC_SLOCK(p); 2389 wakeup_swapper = sig_suspend_threads(td, p, 1); 2390 if (p->p_numthreads == p->p_suspcount) { 2391 /* 2392 * only thread sending signal to another 2393 * process can reach here, if thread is sending 2394 * signal to its process, because thread does 2395 * not suspend itself here, p_numthreads 2396 * should never be equal to p_suspcount. 2397 */ 2398 thread_stopped(p); 2399 PROC_SUNLOCK(p); 2400 sigqueue_delete_proc(p, p->p_xsig); 2401 } else 2402 PROC_SUNLOCK(p); 2403 goto out; 2404 } 2405 } else { 2406 /* Not in "NORMAL" state. discard the signal. */ 2407 sigqueue_delete(sigqueue, sig); 2408 goto out; 2409 } 2410 2411 /* 2412 * The process is not stopped so we need to apply the signal to all the 2413 * running threads. 2414 */ 2415 runfast: 2416 tdsigwakeup(td, sig, action, intrval); 2417 PROC_SLOCK(p); 2418 thread_unsuspend(p); 2419 PROC_SUNLOCK(p); 2420 out: 2421 /* If we jump here, proc slock should not be owned. */ 2422 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2423 if (wakeup_swapper) 2424 kick_proc0(); 2425 2426 return (ret); 2427 } 2428 2429 /* 2430 * The force of a signal has been directed against a single 2431 * thread. We need to see what we can do about knocking it 2432 * out of any sleep it may be in etc. 2433 */ 2434 static void 2435 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2436 { 2437 struct proc *p = td->td_proc; 2438 int prop, wakeup_swapper; 2439 2440 PROC_LOCK_ASSERT(p, MA_OWNED); 2441 prop = sigprop(sig); 2442 2443 PROC_SLOCK(p); 2444 thread_lock(td); 2445 /* 2446 * Bring the priority of a thread up if we want it to get 2447 * killed in this lifetime. Be careful to avoid bumping the 2448 * priority of the idle thread, since we still allow to signal 2449 * kernel processes. 2450 */ 2451 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2452 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2453 sched_prio(td, PUSER); 2454 if (TD_ON_SLEEPQ(td)) { 2455 /* 2456 * If thread is sleeping uninterruptibly 2457 * we can't interrupt the sleep... the signal will 2458 * be noticed when the process returns through 2459 * trap() or syscall(). 2460 */ 2461 if ((td->td_flags & TDF_SINTR) == 0) 2462 goto out; 2463 /* 2464 * If SIGCONT is default (or ignored) and process is 2465 * asleep, we are finished; the process should not 2466 * be awakened. 2467 */ 2468 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2469 thread_unlock(td); 2470 PROC_SUNLOCK(p); 2471 sigqueue_delete(&p->p_sigqueue, sig); 2472 /* 2473 * It may be on either list in this state. 2474 * Remove from both for now. 2475 */ 2476 sigqueue_delete(&td->td_sigqueue, sig); 2477 return; 2478 } 2479 2480 /* 2481 * Don't awaken a sleeping thread for SIGSTOP if the 2482 * STOP signal is deferred. 2483 */ 2484 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2485 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2486 goto out; 2487 2488 /* 2489 * Give low priority threads a better chance to run. 2490 */ 2491 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2492 sched_prio(td, PUSER); 2493 2494 wakeup_swapper = sleepq_abort(td, intrval); 2495 PROC_SUNLOCK(p); 2496 if (wakeup_swapper) 2497 kick_proc0(); 2498 return; 2499 } 2500 2501 /* 2502 * Other states do nothing with the signal immediately, 2503 * other than kicking ourselves if we are running. 2504 * It will either never be noticed, or noticed very soon. 2505 */ 2506 #ifdef SMP 2507 if (TD_IS_RUNNING(td) && td != curthread) 2508 forward_signal(td); 2509 #endif 2510 2511 out: 2512 PROC_SUNLOCK(p); 2513 thread_unlock(td); 2514 } 2515 2516 static int 2517 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2518 { 2519 struct thread *td2; 2520 int wakeup_swapper; 2521 2522 PROC_LOCK_ASSERT(p, MA_OWNED); 2523 PROC_SLOCK_ASSERT(p, MA_OWNED); 2524 MPASS(sending || td == curthread); 2525 2526 wakeup_swapper = 0; 2527 FOREACH_THREAD_IN_PROC(p, td2) { 2528 thread_lock(td2); 2529 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2530 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2531 (td2->td_flags & TDF_SINTR)) { 2532 if (td2->td_flags & TDF_SBDRY) { 2533 /* 2534 * Once a thread is asleep with 2535 * TDF_SBDRY and without TDF_SERESTART 2536 * or TDF_SEINTR set, it should never 2537 * become suspended due to this check. 2538 */ 2539 KASSERT(!TD_IS_SUSPENDED(td2), 2540 ("thread with deferred stops suspended")); 2541 if (TD_SBDRY_INTR(td2)) { 2542 wakeup_swapper |= sleepq_abort(td2, 2543 TD_SBDRY_ERRNO(td2)); 2544 continue; 2545 } 2546 } else if (!TD_IS_SUSPENDED(td2)) 2547 thread_suspend_one(td2); 2548 } else if (!TD_IS_SUSPENDED(td2)) { 2549 if (sending || td != td2) 2550 td2->td_flags |= TDF_ASTPENDING; 2551 #ifdef SMP 2552 if (TD_IS_RUNNING(td2) && td2 != td) 2553 forward_signal(td2); 2554 #endif 2555 } 2556 thread_unlock(td2); 2557 } 2558 return (wakeup_swapper); 2559 } 2560 2561 /* 2562 * Stop the process for an event deemed interesting to the debugger. If si is 2563 * non-NULL, this is a signal exchange; the new signal requested by the 2564 * debugger will be returned for handling. If si is NULL, this is some other 2565 * type of interesting event. The debugger may request a signal be delivered in 2566 * that case as well, however it will be deferred until it can be handled. 2567 */ 2568 int 2569 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2570 { 2571 struct proc *p = td->td_proc; 2572 struct thread *td2; 2573 ksiginfo_t ksi; 2574 2575 PROC_LOCK_ASSERT(p, MA_OWNED); 2576 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2577 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2578 &p->p_mtx.lock_object, "Stopping for traced signal"); 2579 2580 td->td_xsig = sig; 2581 2582 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2583 td->td_dbgflags |= TDB_XSIG; 2584 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2585 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2586 PROC_SLOCK(p); 2587 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2588 if (P_KILLED(p)) { 2589 /* 2590 * Ensure that, if we've been PT_KILLed, the 2591 * exit status reflects that. Another thread 2592 * may also be in ptracestop(), having just 2593 * received the SIGKILL, but this thread was 2594 * unsuspended first. 2595 */ 2596 td->td_dbgflags &= ~TDB_XSIG; 2597 td->td_xsig = SIGKILL; 2598 p->p_ptevents = 0; 2599 break; 2600 } 2601 if (p->p_flag & P_SINGLE_EXIT && 2602 !(td->td_dbgflags & TDB_EXIT)) { 2603 /* 2604 * Ignore ptrace stops except for thread exit 2605 * events when the process exits. 2606 */ 2607 td->td_dbgflags &= ~TDB_XSIG; 2608 PROC_SUNLOCK(p); 2609 return (0); 2610 } 2611 2612 /* 2613 * Make wait(2) work. Ensure that right after the 2614 * attach, the thread which was decided to become the 2615 * leader of attach gets reported to the waiter. 2616 * Otherwise, just avoid overwriting another thread's 2617 * assignment to p_xthread. If another thread has 2618 * already set p_xthread, the current thread will get 2619 * a chance to report itself upon the next iteration. 2620 */ 2621 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2622 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2623 p->p_xthread == NULL)) { 2624 p->p_xsig = sig; 2625 p->p_xthread = td; 2626 2627 /* 2628 * If we are on sleepqueue already, 2629 * let sleepqueue code decide if it 2630 * needs to go sleep after attach. 2631 */ 2632 if (td->td_wchan == NULL) 2633 td->td_dbgflags &= ~TDB_FSTP; 2634 2635 p->p_flag2 &= ~P2_PTRACE_FSTP; 2636 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2637 sig_suspend_threads(td, p, 0); 2638 } 2639 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2640 td->td_dbgflags &= ~TDB_STOPATFORK; 2641 } 2642 stopme: 2643 thread_suspend_switch(td, p); 2644 if (p->p_xthread == td) 2645 p->p_xthread = NULL; 2646 if (!(p->p_flag & P_TRACED)) 2647 break; 2648 if (td->td_dbgflags & TDB_SUSPEND) { 2649 if (p->p_flag & P_SINGLE_EXIT) 2650 break; 2651 goto stopme; 2652 } 2653 } 2654 PROC_SUNLOCK(p); 2655 } 2656 2657 if (si != NULL && sig == td->td_xsig) { 2658 /* Parent wants us to take the original signal unchanged. */ 2659 si->ksi_flags |= KSI_HEAD; 2660 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2661 si->ksi_signo = 0; 2662 } else if (td->td_xsig != 0) { 2663 /* 2664 * If parent wants us to take a new signal, then it will leave 2665 * it in td->td_xsig; otherwise we just look for signals again. 2666 */ 2667 ksiginfo_init(&ksi); 2668 ksi.ksi_signo = td->td_xsig; 2669 ksi.ksi_flags |= KSI_PTRACE; 2670 td2 = sigtd(p, td->td_xsig, false); 2671 tdsendsignal(p, td2, td->td_xsig, &ksi); 2672 if (td != td2) 2673 return (0); 2674 } 2675 2676 return (td->td_xsig); 2677 } 2678 2679 void 2680 reschedule_signals(struct proc *p, sigset_t block, int flags) 2681 { 2682 struct sigacts *ps; 2683 struct thread *td; 2684 int sig; 2685 bool fastblk, pslocked; 2686 2687 PROC_LOCK_ASSERT(p, MA_OWNED); 2688 ps = p->p_sigacts; 2689 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2690 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2691 if (SIGISEMPTY(p->p_siglist)) 2692 return; 2693 SIGSETAND(block, p->p_siglist); 2694 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2695 while ((sig = sig_ffs(&block)) != 0) { 2696 SIGDELSET(block, sig); 2697 td = sigtd(p, sig, fastblk); 2698 2699 /* 2700 * If sigtd() selected us despite sigfastblock is 2701 * blocking, do not activate AST or wake us, to avoid 2702 * loop in AST handler. 2703 */ 2704 if (fastblk && td == curthread) 2705 continue; 2706 2707 signotify(td); 2708 if (!pslocked) 2709 mtx_lock(&ps->ps_mtx); 2710 if (p->p_flag & P_TRACED || 2711 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2712 !SIGISMEMBER(td->td_sigmask, sig))) { 2713 tdsigwakeup(td, sig, SIG_CATCH, 2714 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2715 ERESTART)); 2716 } 2717 if (!pslocked) 2718 mtx_unlock(&ps->ps_mtx); 2719 } 2720 } 2721 2722 void 2723 tdsigcleanup(struct thread *td) 2724 { 2725 struct proc *p; 2726 sigset_t unblocked; 2727 2728 p = td->td_proc; 2729 PROC_LOCK_ASSERT(p, MA_OWNED); 2730 2731 sigqueue_flush(&td->td_sigqueue); 2732 if (p->p_numthreads == 1) 2733 return; 2734 2735 /* 2736 * Since we cannot handle signals, notify signal post code 2737 * about this by filling the sigmask. 2738 * 2739 * Also, if needed, wake up thread(s) that do not block the 2740 * same signals as the exiting thread, since the thread might 2741 * have been selected for delivery and woken up. 2742 */ 2743 SIGFILLSET(unblocked); 2744 SIGSETNAND(unblocked, td->td_sigmask); 2745 SIGFILLSET(td->td_sigmask); 2746 reschedule_signals(p, unblocked, 0); 2747 2748 } 2749 2750 static int 2751 sigdeferstop_curr_flags(int cflags) 2752 { 2753 2754 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2755 (cflags & TDF_SBDRY) != 0); 2756 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2757 } 2758 2759 /* 2760 * Defer the delivery of SIGSTOP for the current thread, according to 2761 * the requested mode. Returns previous flags, which must be restored 2762 * by sigallowstop(). 2763 * 2764 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2765 * cleared by the current thread, which allow the lock-less read-only 2766 * accesses below. 2767 */ 2768 int 2769 sigdeferstop_impl(int mode) 2770 { 2771 struct thread *td; 2772 int cflags, nflags; 2773 2774 td = curthread; 2775 cflags = sigdeferstop_curr_flags(td->td_flags); 2776 switch (mode) { 2777 case SIGDEFERSTOP_NOP: 2778 nflags = cflags; 2779 break; 2780 case SIGDEFERSTOP_OFF: 2781 nflags = 0; 2782 break; 2783 case SIGDEFERSTOP_SILENT: 2784 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2785 break; 2786 case SIGDEFERSTOP_EINTR: 2787 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2788 break; 2789 case SIGDEFERSTOP_ERESTART: 2790 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2791 break; 2792 default: 2793 panic("sigdeferstop: invalid mode %x", mode); 2794 break; 2795 } 2796 if (cflags == nflags) 2797 return (SIGDEFERSTOP_VAL_NCHG); 2798 thread_lock(td); 2799 td->td_flags = (td->td_flags & ~cflags) | nflags; 2800 thread_unlock(td); 2801 return (cflags); 2802 } 2803 2804 /* 2805 * Restores the STOP handling mode, typically permitting the delivery 2806 * of SIGSTOP for the current thread. This does not immediately 2807 * suspend if a stop was posted. Instead, the thread will suspend 2808 * either via ast() or a subsequent interruptible sleep. 2809 */ 2810 void 2811 sigallowstop_impl(int prev) 2812 { 2813 struct thread *td; 2814 int cflags; 2815 2816 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2817 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2818 ("sigallowstop: incorrect previous mode %x", prev)); 2819 td = curthread; 2820 cflags = sigdeferstop_curr_flags(td->td_flags); 2821 if (cflags != prev) { 2822 thread_lock(td); 2823 td->td_flags = (td->td_flags & ~cflags) | prev; 2824 thread_unlock(td); 2825 } 2826 } 2827 2828 /* 2829 * If the current process has received a signal (should be caught or cause 2830 * termination, should interrupt current syscall), return the signal number. 2831 * Stop signals with default action are processed immediately, then cleared; 2832 * they aren't returned. This is checked after each entry to the system for 2833 * a syscall or trap (though this can usually be done without calling issignal 2834 * by checking the pending signal masks in cursig.) The normal call 2835 * sequence is 2836 * 2837 * while (sig = cursig(curthread)) 2838 * postsig(sig); 2839 */ 2840 static int 2841 issignal(struct thread *td) 2842 { 2843 struct proc *p; 2844 struct sigacts *ps; 2845 struct sigqueue *queue; 2846 sigset_t sigpending; 2847 ksiginfo_t ksi; 2848 int prop, sig, traced; 2849 2850 p = td->td_proc; 2851 ps = p->p_sigacts; 2852 mtx_assert(&ps->ps_mtx, MA_OWNED); 2853 PROC_LOCK_ASSERT(p, MA_OWNED); 2854 for (;;) { 2855 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2856 2857 sigpending = td->td_sigqueue.sq_signals; 2858 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2859 SIGSETNAND(sigpending, td->td_sigmask); 2860 2861 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2862 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2863 SIG_STOPSIGMASK(sigpending); 2864 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2865 return (0); 2866 2867 /* 2868 * Do fast sigblock if requested by usermode. Since 2869 * we do know that there was a signal pending at this 2870 * point, set the FAST_SIGBLOCK_PEND as indicator for 2871 * usermode to perform a dummy call to 2872 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2873 * delivery of postponed pending signal. 2874 */ 2875 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2876 if (td->td_sigblock_val != 0) 2877 SIGSETNAND(sigpending, fastblock_mask); 2878 if (SIGISEMPTY(sigpending)) { 2879 td->td_pflags |= TDP_SIGFASTPENDING; 2880 return (0); 2881 } 2882 } 2883 2884 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2885 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2886 SIGISMEMBER(sigpending, SIGSTOP)) { 2887 /* 2888 * If debugger just attached, always consume 2889 * SIGSTOP from ptrace(PT_ATTACH) first, to 2890 * execute the debugger attach ritual in 2891 * order. 2892 */ 2893 sig = SIGSTOP; 2894 td->td_dbgflags |= TDB_FSTP; 2895 } else { 2896 sig = sig_ffs(&sigpending); 2897 } 2898 2899 if (p->p_stops & S_SIG) { 2900 mtx_unlock(&ps->ps_mtx); 2901 stopevent(p, S_SIG, sig); 2902 mtx_lock(&ps->ps_mtx); 2903 } 2904 2905 /* 2906 * We should see pending but ignored signals 2907 * only if P_TRACED was on when they were posted. 2908 */ 2909 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2910 sigqueue_delete(&td->td_sigqueue, sig); 2911 sigqueue_delete(&p->p_sigqueue, sig); 2912 continue; 2913 } 2914 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2915 /* 2916 * If traced, always stop. 2917 * Remove old signal from queue before the stop. 2918 * XXX shrug off debugger, it causes siginfo to 2919 * be thrown away. 2920 */ 2921 queue = &td->td_sigqueue; 2922 ksiginfo_init(&ksi); 2923 if (sigqueue_get(queue, sig, &ksi) == 0) { 2924 queue = &p->p_sigqueue; 2925 sigqueue_get(queue, sig, &ksi); 2926 } 2927 td->td_si = ksi.ksi_info; 2928 2929 mtx_unlock(&ps->ps_mtx); 2930 sig = ptracestop(td, sig, &ksi); 2931 mtx_lock(&ps->ps_mtx); 2932 2933 td->td_si.si_signo = 0; 2934 2935 /* 2936 * Keep looking if the debugger discarded or 2937 * replaced the signal. 2938 */ 2939 if (sig == 0) 2940 continue; 2941 2942 /* 2943 * If the signal became masked, re-queue it. 2944 */ 2945 if (SIGISMEMBER(td->td_sigmask, sig)) { 2946 ksi.ksi_flags |= KSI_HEAD; 2947 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2948 continue; 2949 } 2950 2951 /* 2952 * If the traced bit got turned off, requeue 2953 * the signal and go back up to the top to 2954 * rescan signals. This ensures that p_sig* 2955 * and p_sigact are consistent. 2956 */ 2957 if ((p->p_flag & P_TRACED) == 0) { 2958 ksi.ksi_flags |= KSI_HEAD; 2959 sigqueue_add(queue, sig, &ksi); 2960 continue; 2961 } 2962 } 2963 2964 prop = sigprop(sig); 2965 2966 /* 2967 * Decide whether the signal should be returned. 2968 * Return the signal's number, or fall through 2969 * to clear it from the pending mask. 2970 */ 2971 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2972 2973 case (intptr_t)SIG_DFL: 2974 /* 2975 * Don't take default actions on system processes. 2976 */ 2977 if (p->p_pid <= 1) { 2978 #ifdef DIAGNOSTIC 2979 /* 2980 * Are you sure you want to ignore SIGSEGV 2981 * in init? XXX 2982 */ 2983 printf("Process (pid %lu) got signal %d\n", 2984 (u_long)p->p_pid, sig); 2985 #endif 2986 break; /* == ignore */ 2987 } 2988 /* 2989 * If there is a pending stop signal to process with 2990 * default action, stop here, then clear the signal. 2991 * Traced or exiting processes should ignore stops. 2992 * Additionally, a member of an orphaned process group 2993 * should ignore tty stops. 2994 */ 2995 if (prop & SIGPROP_STOP) { 2996 if (p->p_flag & 2997 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2998 (p->p_pgrp->pg_jobc == 0 && 2999 prop & SIGPROP_TTYSTOP)) 3000 break; /* == ignore */ 3001 if (TD_SBDRY_INTR(td)) { 3002 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3003 ("lost TDF_SBDRY")); 3004 return (-1); 3005 } 3006 mtx_unlock(&ps->ps_mtx); 3007 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3008 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3009 sigqueue_delete(&td->td_sigqueue, sig); 3010 sigqueue_delete(&p->p_sigqueue, sig); 3011 p->p_flag |= P_STOPPED_SIG; 3012 p->p_xsig = sig; 3013 PROC_SLOCK(p); 3014 sig_suspend_threads(td, p, 0); 3015 thread_suspend_switch(td, p); 3016 PROC_SUNLOCK(p); 3017 mtx_lock(&ps->ps_mtx); 3018 goto next; 3019 } else if (prop & SIGPROP_IGNORE) { 3020 /* 3021 * Except for SIGCONT, shouldn't get here. 3022 * Default action is to ignore; drop it. 3023 */ 3024 break; /* == ignore */ 3025 } else 3026 return (sig); 3027 /*NOTREACHED*/ 3028 3029 case (intptr_t)SIG_IGN: 3030 /* 3031 * Masking above should prevent us ever trying 3032 * to take action on an ignored signal other 3033 * than SIGCONT, unless process is traced. 3034 */ 3035 if ((prop & SIGPROP_CONT) == 0 && 3036 (p->p_flag & P_TRACED) == 0) 3037 printf("issignal\n"); 3038 break; /* == ignore */ 3039 3040 default: 3041 /* 3042 * This signal has an action, let 3043 * postsig() process it. 3044 */ 3045 return (sig); 3046 } 3047 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3048 sigqueue_delete(&p->p_sigqueue, sig); 3049 next:; 3050 } 3051 /* NOTREACHED */ 3052 } 3053 3054 void 3055 thread_stopped(struct proc *p) 3056 { 3057 int n; 3058 3059 PROC_LOCK_ASSERT(p, MA_OWNED); 3060 PROC_SLOCK_ASSERT(p, MA_OWNED); 3061 n = p->p_suspcount; 3062 if (p == curproc) 3063 n++; 3064 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3065 PROC_SUNLOCK(p); 3066 p->p_flag &= ~P_WAITED; 3067 PROC_LOCK(p->p_pptr); 3068 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3069 CLD_TRAPPED : CLD_STOPPED); 3070 PROC_UNLOCK(p->p_pptr); 3071 PROC_SLOCK(p); 3072 } 3073 } 3074 3075 /* 3076 * Take the action for the specified signal 3077 * from the current set of pending signals. 3078 */ 3079 int 3080 postsig(int sig) 3081 { 3082 struct thread *td; 3083 struct proc *p; 3084 struct sigacts *ps; 3085 sig_t action; 3086 ksiginfo_t ksi; 3087 sigset_t returnmask; 3088 3089 KASSERT(sig != 0, ("postsig")); 3090 3091 td = curthread; 3092 p = td->td_proc; 3093 PROC_LOCK_ASSERT(p, MA_OWNED); 3094 ps = p->p_sigacts; 3095 mtx_assert(&ps->ps_mtx, MA_OWNED); 3096 ksiginfo_init(&ksi); 3097 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3098 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3099 return (0); 3100 ksi.ksi_signo = sig; 3101 if (ksi.ksi_code == SI_TIMER) 3102 itimer_accept(p, ksi.ksi_timerid, &ksi); 3103 action = ps->ps_sigact[_SIG_IDX(sig)]; 3104 #ifdef KTRACE 3105 if (KTRPOINT(td, KTR_PSIG)) 3106 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3107 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3108 #endif 3109 if ((p->p_stops & S_SIG) != 0) { 3110 mtx_unlock(&ps->ps_mtx); 3111 stopevent(p, S_SIG, sig); 3112 mtx_lock(&ps->ps_mtx); 3113 } 3114 3115 if (action == SIG_DFL) { 3116 /* 3117 * Default action, where the default is to kill 3118 * the process. (Other cases were ignored above.) 3119 */ 3120 mtx_unlock(&ps->ps_mtx); 3121 proc_td_siginfo_capture(td, &ksi.ksi_info); 3122 sigexit(td, sig); 3123 /* NOTREACHED */ 3124 } else { 3125 /* 3126 * If we get here, the signal must be caught. 3127 */ 3128 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3129 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3130 ("postsig action: blocked sig %d", sig)); 3131 3132 /* 3133 * Set the new mask value and also defer further 3134 * occurrences of this signal. 3135 * 3136 * Special case: user has done a sigsuspend. Here the 3137 * current mask is not of interest, but rather the 3138 * mask from before the sigsuspend is what we want 3139 * restored after the signal processing is completed. 3140 */ 3141 if (td->td_pflags & TDP_OLDMASK) { 3142 returnmask = td->td_oldsigmask; 3143 td->td_pflags &= ~TDP_OLDMASK; 3144 } else 3145 returnmask = td->td_sigmask; 3146 3147 if (p->p_sig == sig) { 3148 p->p_sig = 0; 3149 } 3150 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3151 postsig_done(sig, td, ps); 3152 } 3153 return (1); 3154 } 3155 3156 void 3157 proc_wkilled(struct proc *p) 3158 { 3159 3160 PROC_LOCK_ASSERT(p, MA_OWNED); 3161 if ((p->p_flag & P_WKILLED) == 0) { 3162 p->p_flag |= P_WKILLED; 3163 /* 3164 * Notify swapper that there is a process to swap in. 3165 * The notification is racy, at worst it would take 10 3166 * seconds for the swapper process to notice. 3167 */ 3168 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3169 wakeup(&proc0); 3170 } 3171 } 3172 3173 /* 3174 * Kill the current process for stated reason. 3175 */ 3176 void 3177 killproc(struct proc *p, char *why) 3178 { 3179 3180 PROC_LOCK_ASSERT(p, MA_OWNED); 3181 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3182 p->p_comm); 3183 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3184 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3185 p->p_ucred->cr_uid, why); 3186 proc_wkilled(p); 3187 kern_psignal(p, SIGKILL); 3188 } 3189 3190 /* 3191 * Force the current process to exit with the specified signal, dumping core 3192 * if appropriate. We bypass the normal tests for masked and caught signals, 3193 * allowing unrecoverable failures to terminate the process without changing 3194 * signal state. Mark the accounting record with the signal termination. 3195 * If dumping core, save the signal number for the debugger. Calls exit and 3196 * does not return. 3197 */ 3198 void 3199 sigexit(struct thread *td, int sig) 3200 { 3201 struct proc *p = td->td_proc; 3202 3203 PROC_LOCK_ASSERT(p, MA_OWNED); 3204 p->p_acflag |= AXSIG; 3205 /* 3206 * We must be single-threading to generate a core dump. This 3207 * ensures that the registers in the core file are up-to-date. 3208 * Also, the ELF dump handler assumes that the thread list doesn't 3209 * change out from under it. 3210 * 3211 * XXX If another thread attempts to single-thread before us 3212 * (e.g. via fork()), we won't get a dump at all. 3213 */ 3214 if ((sigprop(sig) & SIGPROP_CORE) && 3215 thread_single(p, SINGLE_NO_EXIT) == 0) { 3216 p->p_sig = sig; 3217 /* 3218 * Log signals which would cause core dumps 3219 * (Log as LOG_INFO to appease those who don't want 3220 * these messages.) 3221 * XXX : Todo, as well as euid, write out ruid too 3222 * Note that coredump() drops proc lock. 3223 */ 3224 if (coredump(td) == 0) 3225 sig |= WCOREFLAG; 3226 if (kern_logsigexit) 3227 log(LOG_INFO, 3228 "pid %d (%s), jid %d, uid %d: exited on " 3229 "signal %d%s\n", p->p_pid, p->p_comm, 3230 p->p_ucred->cr_prison->pr_id, 3231 td->td_ucred->cr_uid, 3232 sig &~ WCOREFLAG, 3233 sig & WCOREFLAG ? " (core dumped)" : ""); 3234 } else 3235 PROC_UNLOCK(p); 3236 exit1(td, 0, sig); 3237 /* NOTREACHED */ 3238 } 3239 3240 /* 3241 * Send queued SIGCHLD to parent when child process's state 3242 * is changed. 3243 */ 3244 static void 3245 sigparent(struct proc *p, int reason, int status) 3246 { 3247 PROC_LOCK_ASSERT(p, MA_OWNED); 3248 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3249 3250 if (p->p_ksi != NULL) { 3251 p->p_ksi->ksi_signo = SIGCHLD; 3252 p->p_ksi->ksi_code = reason; 3253 p->p_ksi->ksi_status = status; 3254 p->p_ksi->ksi_pid = p->p_pid; 3255 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3256 if (KSI_ONQ(p->p_ksi)) 3257 return; 3258 } 3259 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3260 } 3261 3262 static void 3263 childproc_jobstate(struct proc *p, int reason, int sig) 3264 { 3265 struct sigacts *ps; 3266 3267 PROC_LOCK_ASSERT(p, MA_OWNED); 3268 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3269 3270 /* 3271 * Wake up parent sleeping in kern_wait(), also send 3272 * SIGCHLD to parent, but SIGCHLD does not guarantee 3273 * that parent will awake, because parent may masked 3274 * the signal. 3275 */ 3276 p->p_pptr->p_flag |= P_STATCHILD; 3277 wakeup(p->p_pptr); 3278 3279 ps = p->p_pptr->p_sigacts; 3280 mtx_lock(&ps->ps_mtx); 3281 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3282 mtx_unlock(&ps->ps_mtx); 3283 sigparent(p, reason, sig); 3284 } else 3285 mtx_unlock(&ps->ps_mtx); 3286 } 3287 3288 void 3289 childproc_stopped(struct proc *p, int reason) 3290 { 3291 3292 childproc_jobstate(p, reason, p->p_xsig); 3293 } 3294 3295 void 3296 childproc_continued(struct proc *p) 3297 { 3298 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3299 } 3300 3301 void 3302 childproc_exited(struct proc *p) 3303 { 3304 int reason, status; 3305 3306 if (WCOREDUMP(p->p_xsig)) { 3307 reason = CLD_DUMPED; 3308 status = WTERMSIG(p->p_xsig); 3309 } else if (WIFSIGNALED(p->p_xsig)) { 3310 reason = CLD_KILLED; 3311 status = WTERMSIG(p->p_xsig); 3312 } else { 3313 reason = CLD_EXITED; 3314 status = p->p_xexit; 3315 } 3316 /* 3317 * XXX avoid calling wakeup(p->p_pptr), the work is 3318 * done in exit1(). 3319 */ 3320 sigparent(p, reason, status); 3321 } 3322 3323 #define MAX_NUM_CORE_FILES 100000 3324 #ifndef NUM_CORE_FILES 3325 #define NUM_CORE_FILES 5 3326 #endif 3327 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3328 static int num_cores = NUM_CORE_FILES; 3329 3330 static int 3331 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3332 { 3333 int error; 3334 int new_val; 3335 3336 new_val = num_cores; 3337 error = sysctl_handle_int(oidp, &new_val, 0, req); 3338 if (error != 0 || req->newptr == NULL) 3339 return (error); 3340 if (new_val > MAX_NUM_CORE_FILES) 3341 new_val = MAX_NUM_CORE_FILES; 3342 if (new_val < 0) 3343 new_val = 0; 3344 num_cores = new_val; 3345 return (0); 3346 } 3347 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3348 0, sizeof(int), sysctl_debug_num_cores_check, "I", 3349 "Maximum number of generated process corefiles while using index format"); 3350 3351 #define GZIP_SUFFIX ".gz" 3352 #define ZSTD_SUFFIX ".zst" 3353 3354 int compress_user_cores = 0; 3355 3356 static int 3357 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3358 { 3359 int error, val; 3360 3361 val = compress_user_cores; 3362 error = sysctl_handle_int(oidp, &val, 0, req); 3363 if (error != 0 || req->newptr == NULL) 3364 return (error); 3365 if (val != 0 && !compressor_avail(val)) 3366 return (EINVAL); 3367 compress_user_cores = val; 3368 return (error); 3369 } 3370 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, CTLTYPE_INT | CTLFLAG_RWTUN, 3371 0, sizeof(int), sysctl_compress_user_cores, "I", 3372 "Enable compression of user corefiles (" 3373 __XSTRING(COMPRESS_GZIP) " = gzip, " 3374 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3375 3376 int compress_user_cores_level = 6; 3377 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3378 &compress_user_cores_level, 0, 3379 "Corefile compression level"); 3380 3381 /* 3382 * Protect the access to corefilename[] by allproc_lock. 3383 */ 3384 #define corefilename_lock allproc_lock 3385 3386 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3387 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3388 3389 static int 3390 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3391 { 3392 int error; 3393 3394 sx_xlock(&corefilename_lock); 3395 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3396 req); 3397 sx_xunlock(&corefilename_lock); 3398 3399 return (error); 3400 } 3401 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3402 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3403 "Process corefile name format string"); 3404 3405 static void 3406 vnode_close_locked(struct thread *td, struct vnode *vp) 3407 { 3408 3409 VOP_UNLOCK(vp); 3410 vn_close(vp, FWRITE, td->td_ucred, td); 3411 } 3412 3413 /* 3414 * If the core format has a %I in it, then we need to check 3415 * for existing corefiles before defining a name. 3416 * To do this we iterate over 0..ncores to find a 3417 * non-existing core file name to use. If all core files are 3418 * already used we choose the oldest one. 3419 */ 3420 static int 3421 corefile_open_last(struct thread *td, char *name, int indexpos, 3422 int indexlen, int ncores, struct vnode **vpp) 3423 { 3424 struct vnode *oldvp, *nextvp, *vp; 3425 struct vattr vattr; 3426 struct nameidata nd; 3427 int error, i, flags, oflags, cmode; 3428 char ch; 3429 struct timespec lasttime; 3430 3431 nextvp = oldvp = NULL; 3432 cmode = S_IRUSR | S_IWUSR; 3433 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3434 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3435 3436 for (i = 0; i < ncores; i++) { 3437 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3438 3439 ch = name[indexpos + indexlen]; 3440 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3441 i); 3442 name[indexpos + indexlen] = ch; 3443 3444 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3445 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3446 NULL); 3447 if (error != 0) 3448 break; 3449 3450 vp = nd.ni_vp; 3451 NDFREE(&nd, NDF_ONLY_PNBUF); 3452 if ((flags & O_CREAT) == O_CREAT) { 3453 nextvp = vp; 3454 break; 3455 } 3456 3457 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3458 if (error != 0) { 3459 vnode_close_locked(td, vp); 3460 break; 3461 } 3462 3463 if (oldvp == NULL || 3464 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3465 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3466 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3467 if (oldvp != NULL) 3468 vnode_close_locked(td, oldvp); 3469 oldvp = vp; 3470 lasttime = vattr.va_mtime; 3471 } else { 3472 vnode_close_locked(td, vp); 3473 } 3474 } 3475 3476 if (oldvp != NULL) { 3477 if (nextvp == NULL) { 3478 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3479 error = EFAULT; 3480 vnode_close_locked(td, oldvp); 3481 } else { 3482 nextvp = oldvp; 3483 } 3484 } else { 3485 vnode_close_locked(td, oldvp); 3486 } 3487 } 3488 if (error != 0) { 3489 if (nextvp != NULL) 3490 vnode_close_locked(td, oldvp); 3491 } else { 3492 *vpp = nextvp; 3493 } 3494 3495 return (error); 3496 } 3497 3498 /* 3499 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3500 * Expand the name described in corefilename, using name, uid, and pid 3501 * and open/create core file. 3502 * corefilename is a printf-like string, with three format specifiers: 3503 * %N name of process ("name") 3504 * %P process id (pid) 3505 * %U user id (uid) 3506 * For example, "%N.core" is the default; they can be disabled completely 3507 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3508 * This is controlled by the sysctl variable kern.corefile (see above). 3509 */ 3510 static int 3511 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3512 int compress, int signum, struct vnode **vpp, char **namep) 3513 { 3514 struct sbuf sb; 3515 struct nameidata nd; 3516 const char *format; 3517 char *hostname, *name; 3518 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3519 3520 hostname = NULL; 3521 format = corefilename; 3522 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3523 indexlen = 0; 3524 indexpos = -1; 3525 ncores = num_cores; 3526 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3527 sx_slock(&corefilename_lock); 3528 for (i = 0; format[i] != '\0'; i++) { 3529 switch (format[i]) { 3530 case '%': /* Format character */ 3531 i++; 3532 switch (format[i]) { 3533 case '%': 3534 sbuf_putc(&sb, '%'); 3535 break; 3536 case 'H': /* hostname */ 3537 if (hostname == NULL) { 3538 hostname = malloc(MAXHOSTNAMELEN, 3539 M_TEMP, M_WAITOK); 3540 } 3541 getcredhostname(td->td_ucred, hostname, 3542 MAXHOSTNAMELEN); 3543 sbuf_printf(&sb, "%s", hostname); 3544 break; 3545 case 'I': /* autoincrementing index */ 3546 if (indexpos != -1) { 3547 sbuf_printf(&sb, "%%I"); 3548 break; 3549 } 3550 3551 indexpos = sbuf_len(&sb); 3552 sbuf_printf(&sb, "%u", ncores - 1); 3553 indexlen = sbuf_len(&sb) - indexpos; 3554 break; 3555 case 'N': /* process name */ 3556 sbuf_printf(&sb, "%s", comm); 3557 break; 3558 case 'P': /* process id */ 3559 sbuf_printf(&sb, "%u", pid); 3560 break; 3561 case 'S': /* signal number */ 3562 sbuf_printf(&sb, "%i", signum); 3563 break; 3564 case 'U': /* user id */ 3565 sbuf_printf(&sb, "%u", uid); 3566 break; 3567 default: 3568 log(LOG_ERR, 3569 "Unknown format character %c in " 3570 "corename `%s'\n", format[i], format); 3571 break; 3572 } 3573 break; 3574 default: 3575 sbuf_putc(&sb, format[i]); 3576 break; 3577 } 3578 } 3579 sx_sunlock(&corefilename_lock); 3580 free(hostname, M_TEMP); 3581 if (compress == COMPRESS_GZIP) 3582 sbuf_printf(&sb, GZIP_SUFFIX); 3583 else if (compress == COMPRESS_ZSTD) 3584 sbuf_printf(&sb, ZSTD_SUFFIX); 3585 if (sbuf_error(&sb) != 0) { 3586 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3587 "long\n", (long)pid, comm, (u_long)uid); 3588 sbuf_delete(&sb); 3589 free(name, M_TEMP); 3590 return (ENOMEM); 3591 } 3592 sbuf_finish(&sb); 3593 sbuf_delete(&sb); 3594 3595 if (indexpos != -1) { 3596 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3597 vpp); 3598 if (error != 0) { 3599 log(LOG_ERR, 3600 "pid %d (%s), uid (%u): Path `%s' failed " 3601 "on initial open test, error = %d\n", 3602 pid, comm, uid, name, error); 3603 } 3604 } else { 3605 cmode = S_IRUSR | S_IWUSR; 3606 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3607 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3608 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3609 if ((td->td_proc->p_flag & P_SUGID) != 0) 3610 flags |= O_EXCL; 3611 3612 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3613 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3614 NULL); 3615 if (error == 0) { 3616 *vpp = nd.ni_vp; 3617 NDFREE(&nd, NDF_ONLY_PNBUF); 3618 } 3619 } 3620 3621 if (error != 0) { 3622 #ifdef AUDIT 3623 audit_proc_coredump(td, name, error); 3624 #endif 3625 free(name, M_TEMP); 3626 return (error); 3627 } 3628 *namep = name; 3629 return (0); 3630 } 3631 3632 /* 3633 * Dump a process' core. The main routine does some 3634 * policy checking, and creates the name of the coredump; 3635 * then it passes on a vnode and a size limit to the process-specific 3636 * coredump routine if there is one; if there _is not_ one, it returns 3637 * ENOSYS; otherwise it returns the error from the process-specific routine. 3638 */ 3639 3640 static int 3641 coredump(struct thread *td) 3642 { 3643 struct proc *p = td->td_proc; 3644 struct ucred *cred = td->td_ucred; 3645 struct vnode *vp; 3646 struct flock lf; 3647 struct vattr vattr; 3648 size_t fullpathsize; 3649 int error, error1, locked; 3650 char *name; /* name of corefile */ 3651 void *rl_cookie; 3652 off_t limit; 3653 char *fullpath, *freepath = NULL; 3654 struct sbuf *sb; 3655 3656 PROC_LOCK_ASSERT(p, MA_OWNED); 3657 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3658 _STOPEVENT(p, S_CORE, 0); 3659 3660 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3661 (p->p_flag2 & P2_NOTRACE) != 0) { 3662 PROC_UNLOCK(p); 3663 return (EFAULT); 3664 } 3665 3666 /* 3667 * Note that the bulk of limit checking is done after 3668 * the corefile is created. The exception is if the limit 3669 * for corefiles is 0, in which case we don't bother 3670 * creating the corefile at all. This layout means that 3671 * a corefile is truncated instead of not being created, 3672 * if it is larger than the limit. 3673 */ 3674 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3675 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3676 PROC_UNLOCK(p); 3677 return (EFBIG); 3678 } 3679 PROC_UNLOCK(p); 3680 3681 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3682 compress_user_cores, p->p_sig, &vp, &name); 3683 if (error != 0) 3684 return (error); 3685 3686 /* 3687 * Don't dump to non-regular files or files with links. 3688 * Do not dump into system files. Effective user must own the corefile. 3689 */ 3690 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3691 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3692 vattr.va_uid != cred->cr_uid) { 3693 VOP_UNLOCK(vp); 3694 error = EFAULT; 3695 goto out; 3696 } 3697 3698 VOP_UNLOCK(vp); 3699 3700 /* Postpone other writers, including core dumps of other processes. */ 3701 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3702 3703 lf.l_whence = SEEK_SET; 3704 lf.l_start = 0; 3705 lf.l_len = 0; 3706 lf.l_type = F_WRLCK; 3707 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3708 3709 VATTR_NULL(&vattr); 3710 vattr.va_size = 0; 3711 if (set_core_nodump_flag) 3712 vattr.va_flags = UF_NODUMP; 3713 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3714 VOP_SETATTR(vp, &vattr, cred); 3715 VOP_UNLOCK(vp); 3716 PROC_LOCK(p); 3717 p->p_acflag |= ACORE; 3718 PROC_UNLOCK(p); 3719 3720 if (p->p_sysent->sv_coredump != NULL) { 3721 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3722 } else { 3723 error = ENOSYS; 3724 } 3725 3726 if (locked) { 3727 lf.l_type = F_UNLCK; 3728 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3729 } 3730 vn_rangelock_unlock(vp, rl_cookie); 3731 3732 /* 3733 * Notify the userland helper that a process triggered a core dump. 3734 * This allows the helper to run an automated debugging session. 3735 */ 3736 if (error != 0 || coredump_devctl == 0) 3737 goto out; 3738 sb = sbuf_new_auto(); 3739 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3740 goto out2; 3741 sbuf_printf(sb, "comm=\""); 3742 devctl_safe_quote_sb(sb, fullpath); 3743 free(freepath, M_TEMP); 3744 sbuf_printf(sb, "\" core=\""); 3745 3746 /* 3747 * We can't lookup core file vp directly. When we're replacing a core, and 3748 * other random times, we flush the name cache, so it will fail. Instead, 3749 * if the path of the core is relative, add the current dir in front if it. 3750 */ 3751 if (name[0] != '/') { 3752 fullpathsize = MAXPATHLEN; 3753 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3754 if (vn_getcwd(td, freepath, &fullpath, &fullpathsize) != 0) { 3755 free(freepath, M_TEMP); 3756 goto out2; 3757 } 3758 devctl_safe_quote_sb(sb, fullpath); 3759 free(freepath, M_TEMP); 3760 sbuf_putc(sb, '/'); 3761 } 3762 devctl_safe_quote_sb(sb, name); 3763 sbuf_printf(sb, "\""); 3764 if (sbuf_finish(sb) == 0) 3765 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3766 out2: 3767 sbuf_delete(sb); 3768 out: 3769 error1 = vn_close(vp, FWRITE, cred, td); 3770 if (error == 0) 3771 error = error1; 3772 #ifdef AUDIT 3773 audit_proc_coredump(td, name, error); 3774 #endif 3775 free(name, M_TEMP); 3776 return (error); 3777 } 3778 3779 /* 3780 * Nonexistent system call-- signal process (may want to handle it). Flag 3781 * error in case process won't see signal immediately (blocked or ignored). 3782 */ 3783 #ifndef _SYS_SYSPROTO_H_ 3784 struct nosys_args { 3785 int dummy; 3786 }; 3787 #endif 3788 /* ARGSUSED */ 3789 int 3790 nosys(struct thread *td, struct nosys_args *args) 3791 { 3792 struct proc *p; 3793 3794 p = td->td_proc; 3795 3796 PROC_LOCK(p); 3797 tdsignal(td, SIGSYS); 3798 PROC_UNLOCK(p); 3799 if (kern_lognosys == 1 || kern_lognosys == 3) { 3800 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3801 td->td_sa.code); 3802 } 3803 if (kern_lognosys == 2 || kern_lognosys == 3) { 3804 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3805 td->td_sa.code); 3806 } 3807 return (ENOSYS); 3808 } 3809 3810 /* 3811 * Send a SIGIO or SIGURG signal to a process or process group using stored 3812 * credentials rather than those of the current process. 3813 */ 3814 void 3815 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3816 { 3817 ksiginfo_t ksi; 3818 struct sigio *sigio; 3819 3820 ksiginfo_init(&ksi); 3821 ksi.ksi_signo = sig; 3822 ksi.ksi_code = SI_KERNEL; 3823 3824 SIGIO_LOCK(); 3825 sigio = *sigiop; 3826 if (sigio == NULL) { 3827 SIGIO_UNLOCK(); 3828 return; 3829 } 3830 if (sigio->sio_pgid > 0) { 3831 PROC_LOCK(sigio->sio_proc); 3832 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3833 kern_psignal(sigio->sio_proc, sig); 3834 PROC_UNLOCK(sigio->sio_proc); 3835 } else if (sigio->sio_pgid < 0) { 3836 struct proc *p; 3837 3838 PGRP_LOCK(sigio->sio_pgrp); 3839 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3840 PROC_LOCK(p); 3841 if (p->p_state == PRS_NORMAL && 3842 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3843 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3844 kern_psignal(p, sig); 3845 PROC_UNLOCK(p); 3846 } 3847 PGRP_UNLOCK(sigio->sio_pgrp); 3848 } 3849 SIGIO_UNLOCK(); 3850 } 3851 3852 static int 3853 filt_sigattach(struct knote *kn) 3854 { 3855 struct proc *p = curproc; 3856 3857 kn->kn_ptr.p_proc = p; 3858 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3859 3860 knlist_add(p->p_klist, kn, 0); 3861 3862 return (0); 3863 } 3864 3865 static void 3866 filt_sigdetach(struct knote *kn) 3867 { 3868 struct proc *p = kn->kn_ptr.p_proc; 3869 3870 knlist_remove(p->p_klist, kn, 0); 3871 } 3872 3873 /* 3874 * signal knotes are shared with proc knotes, so we apply a mask to 3875 * the hint in order to differentiate them from process hints. This 3876 * could be avoided by using a signal-specific knote list, but probably 3877 * isn't worth the trouble. 3878 */ 3879 static int 3880 filt_signal(struct knote *kn, long hint) 3881 { 3882 3883 if (hint & NOTE_SIGNAL) { 3884 hint &= ~NOTE_SIGNAL; 3885 3886 if (kn->kn_id == hint) 3887 kn->kn_data++; 3888 } 3889 return (kn->kn_data != 0); 3890 } 3891 3892 struct sigacts * 3893 sigacts_alloc(void) 3894 { 3895 struct sigacts *ps; 3896 3897 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3898 refcount_init(&ps->ps_refcnt, 1); 3899 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3900 return (ps); 3901 } 3902 3903 void 3904 sigacts_free(struct sigacts *ps) 3905 { 3906 3907 if (refcount_release(&ps->ps_refcnt) == 0) 3908 return; 3909 mtx_destroy(&ps->ps_mtx); 3910 free(ps, M_SUBPROC); 3911 } 3912 3913 struct sigacts * 3914 sigacts_hold(struct sigacts *ps) 3915 { 3916 3917 refcount_acquire(&ps->ps_refcnt); 3918 return (ps); 3919 } 3920 3921 void 3922 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3923 { 3924 3925 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3926 mtx_lock(&src->ps_mtx); 3927 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3928 mtx_unlock(&src->ps_mtx); 3929 } 3930 3931 int 3932 sigacts_shared(struct sigacts *ps) 3933 { 3934 3935 return (ps->ps_refcnt > 1); 3936 } 3937 3938 void 3939 sig_drop_caught(struct proc *p) 3940 { 3941 int sig; 3942 struct sigacts *ps; 3943 3944 ps = p->p_sigacts; 3945 PROC_LOCK_ASSERT(p, MA_OWNED); 3946 mtx_assert(&ps->ps_mtx, MA_OWNED); 3947 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3948 sig = sig_ffs(&ps->ps_sigcatch); 3949 sigdflt(ps, sig); 3950 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3951 sigqueue_delete_proc(p, sig); 3952 } 3953 } 3954 3955 int 3956 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 3957 { 3958 struct proc *p; 3959 int error, res; 3960 uint32_t oldval; 3961 3962 error = 0; 3963 switch (uap->cmd) { 3964 case SIGFASTBLOCK_SETPTR: 3965 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3966 error = EBUSY; 3967 break; 3968 } 3969 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 3970 error = EINVAL; 3971 break; 3972 } 3973 td->td_pflags |= TDP_SIGFASTBLOCK; 3974 td->td_sigblock_ptr = uap->ptr; 3975 break; 3976 3977 case SIGFASTBLOCK_UNBLOCK: 3978 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 3979 error = EINVAL; 3980 break; 3981 } 3982 again: 3983 res = casueword32(td->td_sigblock_ptr, SIGFASTBLOCK_PEND, 3984 &oldval, 0); 3985 if (res == -1) { 3986 error = EFAULT; 3987 break; 3988 } 3989 if (res == 1) { 3990 if (oldval != SIGFASTBLOCK_PEND) { 3991 error = EBUSY; 3992 break; 3993 } 3994 error = thread_check_susp(td, false); 3995 if (error != 0) 3996 break; 3997 goto again; 3998 } 3999 td->td_sigblock_val = 0; 4000 4001 /* 4002 * Rely on normal ast mechanism to deliver pending 4003 * signals to current thread. But notify others about 4004 * fake unblock. 4005 */ 4006 p = td->td_proc; 4007 if (error == 0 && p->p_numthreads != 1) { 4008 PROC_LOCK(p); 4009 reschedule_signals(p, td->td_sigmask, 0); 4010 PROC_UNLOCK(p); 4011 } 4012 break; 4013 4014 case SIGFASTBLOCK_UNSETPTR: 4015 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4016 error = EINVAL; 4017 break; 4018 } 4019 res = fueword32(td->td_sigblock_ptr, &oldval); 4020 if (res == -1) { 4021 error = EFAULT; 4022 break; 4023 } 4024 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4025 error = EBUSY; 4026 break; 4027 } 4028 td->td_pflags &= ~TDP_SIGFASTBLOCK; 4029 td->td_sigblock_val = 0; 4030 break; 4031 4032 default: 4033 error = EINVAL; 4034 break; 4035 } 4036 return (error); 4037 } 4038 4039 void 4040 fetch_sigfastblock(struct thread *td) 4041 { 4042 4043 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4044 return; 4045 if (fueword32(td->td_sigblock_ptr, &td->td_sigblock_val) == -1) { 4046 fetch_sigfastblock_failed(td, false); 4047 return; 4048 } 4049 td->td_sigblock_val &= ~SIGFASTBLOCK_FLAGS; 4050 } 4051 4052 void 4053 fetch_sigfastblock_failed(struct thread *td, bool write) 4054 { 4055 ksiginfo_t ksi; 4056 4057 /* 4058 * Prevent further fetches and SIGSEGVs, allowing thread to 4059 * issue syscalls despite corruption. 4060 */ 4061 td->td_pflags &= ~TDP_SIGFASTBLOCK; 4062 4063 ksiginfo_init_trap(&ksi); 4064 ksi.ksi_signo = SIGSEGV; 4065 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4066 ksi.ksi_addr = td->td_sigblock_ptr; 4067 trapsignal(td, &ksi); 4068 } 4069