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 void reschedule_signals(struct proc *p, sigset_t block, int flags); 112 static int sigprop(int sig); 113 static void tdsigwakeup(struct thread *, int, sig_t, int); 114 static int sig_suspend_threads(struct thread *, struct proc *, int); 115 static int filt_sigattach(struct knote *kn); 116 static void filt_sigdetach(struct knote *kn); 117 static int filt_signal(struct knote *kn, long hint); 118 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 119 static void sigqueue_start(void); 120 121 static uma_zone_t ksiginfo_zone = NULL; 122 struct filterops sig_filtops = { 123 .f_isfd = 0, 124 .f_attach = filt_sigattach, 125 .f_detach = filt_sigdetach, 126 .f_event = filt_signal, 127 }; 128 129 static int kern_logsigexit = 1; 130 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 131 &kern_logsigexit, 0, 132 "Log processes quitting on abnormal signals to syslog(3)"); 133 134 static int kern_forcesigexit = 1; 135 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 136 &kern_forcesigexit, 0, "Force trap signal to be handled"); 137 138 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 139 "POSIX real time signal"); 140 141 static int max_pending_per_proc = 128; 142 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 143 &max_pending_per_proc, 0, "Max pending signals per proc"); 144 145 static int preallocate_siginfo = 1024; 146 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 147 &preallocate_siginfo, 0, "Preallocated signal memory size"); 148 149 static int signal_overflow = 0; 150 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 151 &signal_overflow, 0, "Number of signals overflew"); 152 153 static int signal_alloc_fail = 0; 154 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 155 &signal_alloc_fail, 0, "signals failed to be allocated"); 156 157 static int kern_lognosys = 0; 158 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 159 "Log invalid syscalls"); 160 161 __read_frequently bool sigfastblock_fetch_always = false; 162 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 163 &sigfastblock_fetch_always, 0, 164 "Fetch sigfastblock word on each syscall entry for proper " 165 "blocking semantic"); 166 167 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 168 169 /* 170 * Policy -- Can ucred cr1 send SIGIO to process cr2? 171 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 172 * in the right situations. 173 */ 174 #define CANSIGIO(cr1, cr2) \ 175 ((cr1)->cr_uid == 0 || \ 176 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 177 (cr1)->cr_uid == (cr2)->cr_ruid || \ 178 (cr1)->cr_ruid == (cr2)->cr_uid || \ 179 (cr1)->cr_uid == (cr2)->cr_uid) 180 181 static int sugid_coredump; 182 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 183 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 184 185 static int capmode_coredump; 186 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 187 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 188 189 static int do_coredump = 1; 190 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 191 &do_coredump, 0, "Enable/Disable coredumps"); 192 193 static int set_core_nodump_flag = 0; 194 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 195 0, "Enable setting the NODUMP flag on coredump files"); 196 197 static int coredump_devctl = 0; 198 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 199 0, "Generate a devctl notification when processes coredump"); 200 201 /* 202 * Signal properties and actions. 203 * The array below categorizes the signals and their default actions 204 * according to the following properties: 205 */ 206 #define SIGPROP_KILL 0x01 /* terminates process by default */ 207 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 208 #define SIGPROP_STOP 0x04 /* suspend process */ 209 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 210 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 211 #define SIGPROP_CONT 0x20 /* continue if suspended */ 212 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 213 214 static int sigproptbl[NSIG] = { 215 [SIGHUP] = SIGPROP_KILL, 216 [SIGINT] = SIGPROP_KILL, 217 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 220 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 221 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 222 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 223 [SIGKILL] = SIGPROP_KILL, 224 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 225 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 227 [SIGPIPE] = SIGPROP_KILL, 228 [SIGALRM] = SIGPROP_KILL, 229 [SIGTERM] = SIGPROP_KILL, 230 [SIGURG] = SIGPROP_IGNORE, 231 [SIGSTOP] = SIGPROP_STOP, 232 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 233 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 234 [SIGCHLD] = SIGPROP_IGNORE, 235 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 236 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 237 [SIGIO] = SIGPROP_IGNORE, 238 [SIGXCPU] = SIGPROP_KILL, 239 [SIGXFSZ] = SIGPROP_KILL, 240 [SIGVTALRM] = SIGPROP_KILL, 241 [SIGPROF] = SIGPROP_KILL, 242 [SIGWINCH] = SIGPROP_IGNORE, 243 [SIGINFO] = SIGPROP_IGNORE, 244 [SIGUSR1] = SIGPROP_KILL, 245 [SIGUSR2] = SIGPROP_KILL, 246 }; 247 248 sigset_t fastblock_mask; 249 250 static void 251 sigqueue_start(void) 252 { 253 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 254 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 255 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 256 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 257 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 258 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 259 SIGFILLSET(fastblock_mask); 260 SIG_CANTMASK(fastblock_mask); 261 } 262 263 ksiginfo_t * 264 ksiginfo_alloc(int wait) 265 { 266 int flags; 267 268 flags = M_ZERO; 269 if (! wait) 270 flags |= M_NOWAIT; 271 if (ksiginfo_zone != NULL) 272 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 273 return (NULL); 274 } 275 276 void 277 ksiginfo_free(ksiginfo_t *ksi) 278 { 279 uma_zfree(ksiginfo_zone, ksi); 280 } 281 282 static __inline int 283 ksiginfo_tryfree(ksiginfo_t *ksi) 284 { 285 if (!(ksi->ksi_flags & KSI_EXT)) { 286 uma_zfree(ksiginfo_zone, ksi); 287 return (1); 288 } 289 return (0); 290 } 291 292 void 293 sigqueue_init(sigqueue_t *list, struct proc *p) 294 { 295 SIGEMPTYSET(list->sq_signals); 296 SIGEMPTYSET(list->sq_kill); 297 SIGEMPTYSET(list->sq_ptrace); 298 TAILQ_INIT(&list->sq_list); 299 list->sq_proc = p; 300 list->sq_flags = SQ_INIT; 301 } 302 303 /* 304 * Get a signal's ksiginfo. 305 * Return: 306 * 0 - signal not found 307 * others - signal number 308 */ 309 static int 310 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 311 { 312 struct proc *p = sq->sq_proc; 313 struct ksiginfo *ksi, *next; 314 int count = 0; 315 316 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 317 318 if (!SIGISMEMBER(sq->sq_signals, signo)) 319 return (0); 320 321 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 322 count++; 323 SIGDELSET(sq->sq_ptrace, signo); 324 si->ksi_flags |= KSI_PTRACE; 325 } 326 if (SIGISMEMBER(sq->sq_kill, signo)) { 327 count++; 328 if (count == 1) 329 SIGDELSET(sq->sq_kill, signo); 330 } 331 332 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 333 if (ksi->ksi_signo == signo) { 334 if (count == 0) { 335 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 336 ksi->ksi_sigq = NULL; 337 ksiginfo_copy(ksi, si); 338 if (ksiginfo_tryfree(ksi) && p != NULL) 339 p->p_pendingcnt--; 340 } 341 if (++count > 1) 342 break; 343 } 344 } 345 346 if (count <= 1) 347 SIGDELSET(sq->sq_signals, signo); 348 si->ksi_signo = signo; 349 return (signo); 350 } 351 352 void 353 sigqueue_take(ksiginfo_t *ksi) 354 { 355 struct ksiginfo *kp; 356 struct proc *p; 357 sigqueue_t *sq; 358 359 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 360 return; 361 362 p = sq->sq_proc; 363 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 364 ksi->ksi_sigq = NULL; 365 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 366 p->p_pendingcnt--; 367 368 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 369 kp = TAILQ_NEXT(kp, ksi_link)) { 370 if (kp->ksi_signo == ksi->ksi_signo) 371 break; 372 } 373 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 374 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 375 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 376 } 377 378 static int 379 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 380 { 381 struct proc *p = sq->sq_proc; 382 struct ksiginfo *ksi; 383 int ret = 0; 384 385 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 386 387 /* 388 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 389 * for these signals. 390 */ 391 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 392 SIGADDSET(sq->sq_kill, signo); 393 goto out_set_bit; 394 } 395 396 /* directly insert the ksi, don't copy it */ 397 if (si->ksi_flags & KSI_INS) { 398 if (si->ksi_flags & KSI_HEAD) 399 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 400 else 401 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 402 si->ksi_sigq = sq; 403 goto out_set_bit; 404 } 405 406 if (__predict_false(ksiginfo_zone == NULL)) { 407 SIGADDSET(sq->sq_kill, signo); 408 goto out_set_bit; 409 } 410 411 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 412 signal_overflow++; 413 ret = EAGAIN; 414 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 415 signal_alloc_fail++; 416 ret = EAGAIN; 417 } else { 418 if (p != NULL) 419 p->p_pendingcnt++; 420 ksiginfo_copy(si, ksi); 421 ksi->ksi_signo = signo; 422 if (si->ksi_flags & KSI_HEAD) 423 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 424 else 425 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 426 ksi->ksi_sigq = sq; 427 } 428 429 if (ret != 0) { 430 if ((si->ksi_flags & KSI_PTRACE) != 0) { 431 SIGADDSET(sq->sq_ptrace, signo); 432 ret = 0; 433 goto out_set_bit; 434 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 435 (si->ksi_flags & KSI_SIGQ) == 0) { 436 SIGADDSET(sq->sq_kill, signo); 437 ret = 0; 438 goto out_set_bit; 439 } 440 return (ret); 441 } 442 443 out_set_bit: 444 SIGADDSET(sq->sq_signals, signo); 445 return (ret); 446 } 447 448 void 449 sigqueue_flush(sigqueue_t *sq) 450 { 451 struct proc *p = sq->sq_proc; 452 ksiginfo_t *ksi; 453 454 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 455 456 if (p != NULL) 457 PROC_LOCK_ASSERT(p, MA_OWNED); 458 459 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 460 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 461 ksi->ksi_sigq = NULL; 462 if (ksiginfo_tryfree(ksi) && p != NULL) 463 p->p_pendingcnt--; 464 } 465 466 SIGEMPTYSET(sq->sq_signals); 467 SIGEMPTYSET(sq->sq_kill); 468 SIGEMPTYSET(sq->sq_ptrace); 469 } 470 471 static void 472 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 473 { 474 sigset_t tmp; 475 struct proc *p1, *p2; 476 ksiginfo_t *ksi, *next; 477 478 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 479 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 480 p1 = src->sq_proc; 481 p2 = dst->sq_proc; 482 /* Move siginfo to target list */ 483 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 484 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 485 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 486 if (p1 != NULL) 487 p1->p_pendingcnt--; 488 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 489 ksi->ksi_sigq = dst; 490 if (p2 != NULL) 491 p2->p_pendingcnt++; 492 } 493 } 494 495 /* Move pending bits to target list */ 496 tmp = src->sq_kill; 497 SIGSETAND(tmp, *set); 498 SIGSETOR(dst->sq_kill, tmp); 499 SIGSETNAND(src->sq_kill, tmp); 500 501 tmp = src->sq_ptrace; 502 SIGSETAND(tmp, *set); 503 SIGSETOR(dst->sq_ptrace, tmp); 504 SIGSETNAND(src->sq_ptrace, tmp); 505 506 tmp = src->sq_signals; 507 SIGSETAND(tmp, *set); 508 SIGSETOR(dst->sq_signals, tmp); 509 SIGSETNAND(src->sq_signals, tmp); 510 } 511 512 #if 0 513 static void 514 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 515 { 516 sigset_t set; 517 518 SIGEMPTYSET(set); 519 SIGADDSET(set, signo); 520 sigqueue_move_set(src, dst, &set); 521 } 522 #endif 523 524 static void 525 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 526 { 527 struct proc *p = sq->sq_proc; 528 ksiginfo_t *ksi, *next; 529 530 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 531 532 /* Remove siginfo queue */ 533 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 534 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 535 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 536 ksi->ksi_sigq = NULL; 537 if (ksiginfo_tryfree(ksi) && p != NULL) 538 p->p_pendingcnt--; 539 } 540 } 541 SIGSETNAND(sq->sq_kill, *set); 542 SIGSETNAND(sq->sq_ptrace, *set); 543 SIGSETNAND(sq->sq_signals, *set); 544 } 545 546 void 547 sigqueue_delete(sigqueue_t *sq, int signo) 548 { 549 sigset_t set; 550 551 SIGEMPTYSET(set); 552 SIGADDSET(set, signo); 553 sigqueue_delete_set(sq, &set); 554 } 555 556 /* Remove a set of signals for a process */ 557 static void 558 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 559 { 560 sigqueue_t worklist; 561 struct thread *td0; 562 563 PROC_LOCK_ASSERT(p, MA_OWNED); 564 565 sigqueue_init(&worklist, NULL); 566 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 567 568 FOREACH_THREAD_IN_PROC(p, td0) 569 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 570 571 sigqueue_flush(&worklist); 572 } 573 574 void 575 sigqueue_delete_proc(struct proc *p, int signo) 576 { 577 sigset_t set; 578 579 SIGEMPTYSET(set); 580 SIGADDSET(set, signo); 581 sigqueue_delete_set_proc(p, &set); 582 } 583 584 static void 585 sigqueue_delete_stopmask_proc(struct proc *p) 586 { 587 sigset_t set; 588 589 SIGEMPTYSET(set); 590 SIGADDSET(set, SIGSTOP); 591 SIGADDSET(set, SIGTSTP); 592 SIGADDSET(set, SIGTTIN); 593 SIGADDSET(set, SIGTTOU); 594 sigqueue_delete_set_proc(p, &set); 595 } 596 597 /* 598 * Determine signal that should be delivered to thread td, the current 599 * thread, 0 if none. If there is a pending stop signal with default 600 * action, the process stops in issignal(). 601 */ 602 int 603 cursig(struct thread *td) 604 { 605 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 606 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 607 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 608 return (SIGPENDING(td) ? issignal(td) : 0); 609 } 610 611 /* 612 * Arrange for ast() to handle unmasked pending signals on return to user 613 * mode. This must be called whenever a signal is added to td_sigqueue or 614 * unmasked in td_sigmask. 615 */ 616 void 617 signotify(struct thread *td) 618 { 619 620 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 621 622 if (SIGPENDING(td)) { 623 thread_lock(td); 624 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 625 thread_unlock(td); 626 } 627 } 628 629 /* 630 * Returns 1 (true) if altstack is configured for the thread, and the 631 * passed stack bottom address falls into the altstack range. Handles 632 * the 43 compat special case where the alt stack size is zero. 633 */ 634 int 635 sigonstack(size_t sp) 636 { 637 struct thread *td; 638 639 td = curthread; 640 if ((td->td_pflags & TDP_ALTSTACK) == 0) 641 return (0); 642 #if defined(COMPAT_43) 643 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 644 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 645 #endif 646 return (sp >= (size_t)td->td_sigstk.ss_sp && 647 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 648 } 649 650 static __inline int 651 sigprop(int sig) 652 { 653 654 if (sig > 0 && sig < nitems(sigproptbl)) 655 return (sigproptbl[sig]); 656 return (0); 657 } 658 659 int 660 sig_ffs(sigset_t *set) 661 { 662 int i; 663 664 for (i = 0; i < _SIG_WORDS; i++) 665 if (set->__bits[i]) 666 return (ffs(set->__bits[i]) + (i * 32)); 667 return (0); 668 } 669 670 static bool 671 sigact_flag_test(const struct sigaction *act, int flag) 672 { 673 674 /* 675 * SA_SIGINFO is reset when signal disposition is set to 676 * ignore or default. Other flags are kept according to user 677 * settings. 678 */ 679 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 680 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 681 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 682 } 683 684 /* 685 * kern_sigaction 686 * sigaction 687 * freebsd4_sigaction 688 * osigaction 689 */ 690 int 691 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 692 struct sigaction *oact, int flags) 693 { 694 struct sigacts *ps; 695 struct proc *p = td->td_proc; 696 697 if (!_SIG_VALID(sig)) 698 return (EINVAL); 699 if (act != NULL && act->sa_handler != SIG_DFL && 700 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 701 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 702 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 703 return (EINVAL); 704 705 PROC_LOCK(p); 706 ps = p->p_sigacts; 707 mtx_lock(&ps->ps_mtx); 708 if (oact) { 709 memset(oact, 0, sizeof(*oact)); 710 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 711 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 712 oact->sa_flags |= SA_ONSTACK; 713 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 714 oact->sa_flags |= SA_RESTART; 715 if (SIGISMEMBER(ps->ps_sigreset, sig)) 716 oact->sa_flags |= SA_RESETHAND; 717 if (SIGISMEMBER(ps->ps_signodefer, sig)) 718 oact->sa_flags |= SA_NODEFER; 719 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 720 oact->sa_flags |= SA_SIGINFO; 721 oact->sa_sigaction = 722 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 723 } else 724 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 725 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 726 oact->sa_flags |= SA_NOCLDSTOP; 727 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 728 oact->sa_flags |= SA_NOCLDWAIT; 729 } 730 if (act) { 731 if ((sig == SIGKILL || sig == SIGSTOP) && 732 act->sa_handler != SIG_DFL) { 733 mtx_unlock(&ps->ps_mtx); 734 PROC_UNLOCK(p); 735 return (EINVAL); 736 } 737 738 /* 739 * Change setting atomically. 740 */ 741 742 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 743 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 744 if (sigact_flag_test(act, SA_SIGINFO)) { 745 ps->ps_sigact[_SIG_IDX(sig)] = 746 (__sighandler_t *)act->sa_sigaction; 747 SIGADDSET(ps->ps_siginfo, sig); 748 } else { 749 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 750 SIGDELSET(ps->ps_siginfo, sig); 751 } 752 if (!sigact_flag_test(act, SA_RESTART)) 753 SIGADDSET(ps->ps_sigintr, sig); 754 else 755 SIGDELSET(ps->ps_sigintr, sig); 756 if (sigact_flag_test(act, SA_ONSTACK)) 757 SIGADDSET(ps->ps_sigonstack, sig); 758 else 759 SIGDELSET(ps->ps_sigonstack, sig); 760 if (sigact_flag_test(act, SA_RESETHAND)) 761 SIGADDSET(ps->ps_sigreset, sig); 762 else 763 SIGDELSET(ps->ps_sigreset, sig); 764 if (sigact_flag_test(act, SA_NODEFER)) 765 SIGADDSET(ps->ps_signodefer, sig); 766 else 767 SIGDELSET(ps->ps_signodefer, sig); 768 if (sig == SIGCHLD) { 769 if (act->sa_flags & SA_NOCLDSTOP) 770 ps->ps_flag |= PS_NOCLDSTOP; 771 else 772 ps->ps_flag &= ~PS_NOCLDSTOP; 773 if (act->sa_flags & SA_NOCLDWAIT) { 774 /* 775 * Paranoia: since SA_NOCLDWAIT is implemented 776 * by reparenting the dying child to PID 1 (and 777 * trust it to reap the zombie), PID 1 itself 778 * is forbidden to set SA_NOCLDWAIT. 779 */ 780 if (p->p_pid == 1) 781 ps->ps_flag &= ~PS_NOCLDWAIT; 782 else 783 ps->ps_flag |= PS_NOCLDWAIT; 784 } else 785 ps->ps_flag &= ~PS_NOCLDWAIT; 786 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 787 ps->ps_flag |= PS_CLDSIGIGN; 788 else 789 ps->ps_flag &= ~PS_CLDSIGIGN; 790 } 791 /* 792 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 793 * and for signals set to SIG_DFL where the default is to 794 * ignore. However, don't put SIGCONT in ps_sigignore, as we 795 * have to restart the process. 796 */ 797 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 798 (sigprop(sig) & SIGPROP_IGNORE && 799 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 800 /* never to be seen again */ 801 sigqueue_delete_proc(p, sig); 802 if (sig != SIGCONT) 803 /* easier in psignal */ 804 SIGADDSET(ps->ps_sigignore, sig); 805 SIGDELSET(ps->ps_sigcatch, sig); 806 } else { 807 SIGDELSET(ps->ps_sigignore, sig); 808 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 809 SIGDELSET(ps->ps_sigcatch, sig); 810 else 811 SIGADDSET(ps->ps_sigcatch, sig); 812 } 813 #ifdef COMPAT_FREEBSD4 814 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 815 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 816 (flags & KSA_FREEBSD4) == 0) 817 SIGDELSET(ps->ps_freebsd4, sig); 818 else 819 SIGADDSET(ps->ps_freebsd4, sig); 820 #endif 821 #ifdef COMPAT_43 822 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 823 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 824 (flags & KSA_OSIGSET) == 0) 825 SIGDELSET(ps->ps_osigset, sig); 826 else 827 SIGADDSET(ps->ps_osigset, sig); 828 #endif 829 } 830 mtx_unlock(&ps->ps_mtx); 831 PROC_UNLOCK(p); 832 return (0); 833 } 834 835 #ifndef _SYS_SYSPROTO_H_ 836 struct sigaction_args { 837 int sig; 838 struct sigaction *act; 839 struct sigaction *oact; 840 }; 841 #endif 842 int 843 sys_sigaction(struct thread *td, struct sigaction_args *uap) 844 { 845 struct sigaction act, oact; 846 struct sigaction *actp, *oactp; 847 int error; 848 849 actp = (uap->act != NULL) ? &act : NULL; 850 oactp = (uap->oact != NULL) ? &oact : NULL; 851 if (actp) { 852 error = copyin(uap->act, actp, sizeof(act)); 853 if (error) 854 return (error); 855 } 856 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 857 if (oactp && !error) 858 error = copyout(oactp, uap->oact, sizeof(oact)); 859 return (error); 860 } 861 862 #ifdef COMPAT_FREEBSD4 863 #ifndef _SYS_SYSPROTO_H_ 864 struct freebsd4_sigaction_args { 865 int sig; 866 struct sigaction *act; 867 struct sigaction *oact; 868 }; 869 #endif 870 int 871 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 872 { 873 struct sigaction act, oact; 874 struct sigaction *actp, *oactp; 875 int error; 876 877 actp = (uap->act != NULL) ? &act : NULL; 878 oactp = (uap->oact != NULL) ? &oact : NULL; 879 if (actp) { 880 error = copyin(uap->act, actp, sizeof(act)); 881 if (error) 882 return (error); 883 } 884 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 885 if (oactp && !error) 886 error = copyout(oactp, uap->oact, sizeof(oact)); 887 return (error); 888 } 889 #endif /* COMAPT_FREEBSD4 */ 890 891 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 892 #ifndef _SYS_SYSPROTO_H_ 893 struct osigaction_args { 894 int signum; 895 struct osigaction *nsa; 896 struct osigaction *osa; 897 }; 898 #endif 899 int 900 osigaction(struct thread *td, struct osigaction_args *uap) 901 { 902 struct osigaction sa; 903 struct sigaction nsa, osa; 904 struct sigaction *nsap, *osap; 905 int error; 906 907 if (uap->signum <= 0 || uap->signum >= ONSIG) 908 return (EINVAL); 909 910 nsap = (uap->nsa != NULL) ? &nsa : NULL; 911 osap = (uap->osa != NULL) ? &osa : NULL; 912 913 if (nsap) { 914 error = copyin(uap->nsa, &sa, sizeof(sa)); 915 if (error) 916 return (error); 917 nsap->sa_handler = sa.sa_handler; 918 nsap->sa_flags = sa.sa_flags; 919 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 920 } 921 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 922 if (osap && !error) { 923 sa.sa_handler = osap->sa_handler; 924 sa.sa_flags = osap->sa_flags; 925 SIG2OSIG(osap->sa_mask, sa.sa_mask); 926 error = copyout(&sa, uap->osa, sizeof(sa)); 927 } 928 return (error); 929 } 930 931 #if !defined(__i386__) 932 /* Avoid replicating the same stub everywhere */ 933 int 934 osigreturn(struct thread *td, struct osigreturn_args *uap) 935 { 936 937 return (nosys(td, (struct nosys_args *)uap)); 938 } 939 #endif 940 #endif /* COMPAT_43 */ 941 942 /* 943 * Initialize signal state for process 0; 944 * set to ignore signals that are ignored by default. 945 */ 946 void 947 siginit(struct proc *p) 948 { 949 int i; 950 struct sigacts *ps; 951 952 PROC_LOCK(p); 953 ps = p->p_sigacts; 954 mtx_lock(&ps->ps_mtx); 955 for (i = 1; i <= NSIG; i++) { 956 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 957 SIGADDSET(ps->ps_sigignore, i); 958 } 959 } 960 mtx_unlock(&ps->ps_mtx); 961 PROC_UNLOCK(p); 962 } 963 964 /* 965 * Reset specified signal to the default disposition. 966 */ 967 static void 968 sigdflt(struct sigacts *ps, int sig) 969 { 970 971 mtx_assert(&ps->ps_mtx, MA_OWNED); 972 SIGDELSET(ps->ps_sigcatch, sig); 973 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 974 SIGADDSET(ps->ps_sigignore, sig); 975 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 976 SIGDELSET(ps->ps_siginfo, sig); 977 } 978 979 /* 980 * Reset signals for an exec of the specified process. 981 */ 982 void 983 execsigs(struct proc *p) 984 { 985 sigset_t osigignore; 986 struct sigacts *ps; 987 int sig; 988 struct thread *td; 989 990 /* 991 * Reset caught signals. Held signals remain held 992 * through td_sigmask (unless they were caught, 993 * and are now ignored by default). 994 */ 995 PROC_LOCK_ASSERT(p, MA_OWNED); 996 ps = p->p_sigacts; 997 mtx_lock(&ps->ps_mtx); 998 sig_drop_caught(p); 999 1000 /* 1001 * As CloudABI processes cannot modify signal handlers, fully 1002 * reset all signals to their default behavior. Do ignore 1003 * SIGPIPE, as it would otherwise be impossible to recover from 1004 * writes to broken pipes and sockets. 1005 */ 1006 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1007 osigignore = ps->ps_sigignore; 1008 while (SIGNOTEMPTY(osigignore)) { 1009 sig = sig_ffs(&osigignore); 1010 SIGDELSET(osigignore, sig); 1011 if (sig != SIGPIPE) 1012 sigdflt(ps, sig); 1013 } 1014 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1015 } 1016 1017 /* 1018 * Reset stack state to the user stack. 1019 * Clear set of signals caught on the signal stack. 1020 */ 1021 td = curthread; 1022 MPASS(td->td_proc == p); 1023 td->td_sigstk.ss_flags = SS_DISABLE; 1024 td->td_sigstk.ss_size = 0; 1025 td->td_sigstk.ss_sp = 0; 1026 td->td_pflags &= ~TDP_ALTSTACK; 1027 /* 1028 * Reset no zombies if child dies flag as Solaris does. 1029 */ 1030 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1031 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1032 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1033 mtx_unlock(&ps->ps_mtx); 1034 } 1035 1036 /* 1037 * kern_sigprocmask() 1038 * 1039 * Manipulate signal mask. 1040 */ 1041 int 1042 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1043 int flags) 1044 { 1045 sigset_t new_block, oset1; 1046 struct proc *p; 1047 int error; 1048 1049 p = td->td_proc; 1050 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1051 PROC_LOCK_ASSERT(p, MA_OWNED); 1052 else 1053 PROC_LOCK(p); 1054 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1055 ? MA_OWNED : MA_NOTOWNED); 1056 if (oset != NULL) 1057 *oset = td->td_sigmask; 1058 1059 error = 0; 1060 if (set != NULL) { 1061 switch (how) { 1062 case SIG_BLOCK: 1063 SIG_CANTMASK(*set); 1064 oset1 = td->td_sigmask; 1065 SIGSETOR(td->td_sigmask, *set); 1066 new_block = td->td_sigmask; 1067 SIGSETNAND(new_block, oset1); 1068 break; 1069 case SIG_UNBLOCK: 1070 SIGSETNAND(td->td_sigmask, *set); 1071 signotify(td); 1072 goto out; 1073 case SIG_SETMASK: 1074 SIG_CANTMASK(*set); 1075 oset1 = td->td_sigmask; 1076 if (flags & SIGPROCMASK_OLD) 1077 SIGSETLO(td->td_sigmask, *set); 1078 else 1079 td->td_sigmask = *set; 1080 new_block = td->td_sigmask; 1081 SIGSETNAND(new_block, oset1); 1082 signotify(td); 1083 break; 1084 default: 1085 error = EINVAL; 1086 goto out; 1087 } 1088 1089 /* 1090 * The new_block set contains signals that were not previously 1091 * blocked, but are blocked now. 1092 * 1093 * In case we block any signal that was not previously blocked 1094 * for td, and process has the signal pending, try to schedule 1095 * signal delivery to some thread that does not block the 1096 * signal, possibly waking it up. 1097 */ 1098 if (p->p_numthreads != 1) 1099 reschedule_signals(p, new_block, flags); 1100 } 1101 1102 out: 1103 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1104 PROC_UNLOCK(p); 1105 return (error); 1106 } 1107 1108 #ifndef _SYS_SYSPROTO_H_ 1109 struct sigprocmask_args { 1110 int how; 1111 const sigset_t *set; 1112 sigset_t *oset; 1113 }; 1114 #endif 1115 int 1116 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1117 { 1118 sigset_t set, oset; 1119 sigset_t *setp, *osetp; 1120 int error; 1121 1122 setp = (uap->set != NULL) ? &set : NULL; 1123 osetp = (uap->oset != NULL) ? &oset : NULL; 1124 if (setp) { 1125 error = copyin(uap->set, setp, sizeof(set)); 1126 if (error) 1127 return (error); 1128 } 1129 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1130 if (osetp && !error) { 1131 error = copyout(osetp, uap->oset, sizeof(oset)); 1132 } 1133 return (error); 1134 } 1135 1136 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1137 #ifndef _SYS_SYSPROTO_H_ 1138 struct osigprocmask_args { 1139 int how; 1140 osigset_t mask; 1141 }; 1142 #endif 1143 int 1144 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1145 { 1146 sigset_t set, oset; 1147 int error; 1148 1149 OSIG2SIG(uap->mask, set); 1150 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1151 SIG2OSIG(oset, td->td_retval[0]); 1152 return (error); 1153 } 1154 #endif /* COMPAT_43 */ 1155 1156 int 1157 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1158 { 1159 ksiginfo_t ksi; 1160 sigset_t set; 1161 int error; 1162 1163 error = copyin(uap->set, &set, sizeof(set)); 1164 if (error) { 1165 td->td_retval[0] = error; 1166 return (0); 1167 } 1168 1169 error = kern_sigtimedwait(td, set, &ksi, NULL); 1170 if (error) { 1171 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1172 error = ERESTART; 1173 if (error == ERESTART) 1174 return (error); 1175 td->td_retval[0] = error; 1176 return (0); 1177 } 1178 1179 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1180 td->td_retval[0] = error; 1181 return (0); 1182 } 1183 1184 int 1185 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1186 { 1187 struct timespec ts; 1188 struct timespec *timeout; 1189 sigset_t set; 1190 ksiginfo_t ksi; 1191 int error; 1192 1193 if (uap->timeout) { 1194 error = copyin(uap->timeout, &ts, sizeof(ts)); 1195 if (error) 1196 return (error); 1197 1198 timeout = &ts; 1199 } else 1200 timeout = NULL; 1201 1202 error = copyin(uap->set, &set, sizeof(set)); 1203 if (error) 1204 return (error); 1205 1206 error = kern_sigtimedwait(td, set, &ksi, timeout); 1207 if (error) 1208 return (error); 1209 1210 if (uap->info) 1211 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1212 1213 if (error == 0) 1214 td->td_retval[0] = ksi.ksi_signo; 1215 return (error); 1216 } 1217 1218 int 1219 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1220 { 1221 ksiginfo_t ksi; 1222 sigset_t set; 1223 int error; 1224 1225 error = copyin(uap->set, &set, sizeof(set)); 1226 if (error) 1227 return (error); 1228 1229 error = kern_sigtimedwait(td, set, &ksi, NULL); 1230 if (error) 1231 return (error); 1232 1233 if (uap->info) 1234 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1235 1236 if (error == 0) 1237 td->td_retval[0] = ksi.ksi_signo; 1238 return (error); 1239 } 1240 1241 static void 1242 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1243 { 1244 struct thread *thr; 1245 1246 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1247 if (thr == td) 1248 thr->td_si = *si; 1249 else 1250 thr->td_si.si_signo = 0; 1251 } 1252 } 1253 1254 int 1255 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1256 struct timespec *timeout) 1257 { 1258 struct sigacts *ps; 1259 sigset_t saved_mask, new_block; 1260 struct proc *p; 1261 int error, sig, timo, timevalid = 0; 1262 struct timespec rts, ets, ts; 1263 struct timeval tv; 1264 bool traced; 1265 1266 p = td->td_proc; 1267 error = 0; 1268 ets.tv_sec = 0; 1269 ets.tv_nsec = 0; 1270 traced = false; 1271 1272 if (timeout != NULL) { 1273 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1274 timevalid = 1; 1275 getnanouptime(&rts); 1276 timespecadd(&rts, timeout, &ets); 1277 } 1278 } 1279 ksiginfo_init(ksi); 1280 /* Some signals can not be waited for. */ 1281 SIG_CANTMASK(waitset); 1282 ps = p->p_sigacts; 1283 PROC_LOCK(p); 1284 saved_mask = td->td_sigmask; 1285 SIGSETNAND(td->td_sigmask, waitset); 1286 for (;;) { 1287 mtx_lock(&ps->ps_mtx); 1288 sig = cursig(td); 1289 mtx_unlock(&ps->ps_mtx); 1290 KASSERT(sig >= 0, ("sig %d", sig)); 1291 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1292 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1293 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1294 error = 0; 1295 break; 1296 } 1297 } 1298 1299 if (error != 0) 1300 break; 1301 1302 /* 1303 * POSIX says this must be checked after looking for pending 1304 * signals. 1305 */ 1306 if (timeout != NULL) { 1307 if (!timevalid) { 1308 error = EINVAL; 1309 break; 1310 } 1311 getnanouptime(&rts); 1312 if (timespeccmp(&rts, &ets, >=)) { 1313 error = EAGAIN; 1314 break; 1315 } 1316 timespecsub(&ets, &rts, &ts); 1317 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1318 timo = tvtohz(&tv); 1319 } else { 1320 timo = 0; 1321 } 1322 1323 if (traced) { 1324 error = EINTR; 1325 break; 1326 } 1327 1328 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1329 1330 if (timeout != NULL) { 1331 if (error == ERESTART) { 1332 /* Timeout can not be restarted. */ 1333 error = EINTR; 1334 } else if (error == EAGAIN) { 1335 /* We will calculate timeout by ourself. */ 1336 error = 0; 1337 } 1338 } 1339 1340 /* 1341 * If PTRACE_SCE or PTRACE_SCX were set after 1342 * userspace entered the syscall, return spurious 1343 * EINTR after wait was done. Only do this as last 1344 * resort after rechecking for possible queued signals 1345 * and expired timeouts. 1346 */ 1347 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1348 traced = true; 1349 } 1350 1351 new_block = saved_mask; 1352 SIGSETNAND(new_block, td->td_sigmask); 1353 td->td_sigmask = saved_mask; 1354 /* 1355 * Fewer signals can be delivered to us, reschedule signal 1356 * notification. 1357 */ 1358 if (p->p_numthreads != 1) 1359 reschedule_signals(p, new_block, 0); 1360 1361 if (error == 0) { 1362 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1363 1364 if (ksi->ksi_code == SI_TIMER) 1365 itimer_accept(p, ksi->ksi_timerid, ksi); 1366 1367 #ifdef KTRACE 1368 if (KTRPOINT(td, KTR_PSIG)) { 1369 sig_t action; 1370 1371 mtx_lock(&ps->ps_mtx); 1372 action = ps->ps_sigact[_SIG_IDX(sig)]; 1373 mtx_unlock(&ps->ps_mtx); 1374 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1375 } 1376 #endif 1377 if (sig == SIGKILL) { 1378 proc_td_siginfo_capture(td, &ksi->ksi_info); 1379 sigexit(td, sig); 1380 } 1381 } 1382 PROC_UNLOCK(p); 1383 return (error); 1384 } 1385 1386 #ifndef _SYS_SYSPROTO_H_ 1387 struct sigpending_args { 1388 sigset_t *set; 1389 }; 1390 #endif 1391 int 1392 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1393 { 1394 struct proc *p = td->td_proc; 1395 sigset_t pending; 1396 1397 PROC_LOCK(p); 1398 pending = p->p_sigqueue.sq_signals; 1399 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1400 PROC_UNLOCK(p); 1401 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1402 } 1403 1404 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1405 #ifndef _SYS_SYSPROTO_H_ 1406 struct osigpending_args { 1407 int dummy; 1408 }; 1409 #endif 1410 int 1411 osigpending(struct thread *td, struct osigpending_args *uap) 1412 { 1413 struct proc *p = td->td_proc; 1414 sigset_t pending; 1415 1416 PROC_LOCK(p); 1417 pending = p->p_sigqueue.sq_signals; 1418 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1419 PROC_UNLOCK(p); 1420 SIG2OSIG(pending, td->td_retval[0]); 1421 return (0); 1422 } 1423 #endif /* COMPAT_43 */ 1424 1425 #if defined(COMPAT_43) 1426 /* 1427 * Generalized interface signal handler, 4.3-compatible. 1428 */ 1429 #ifndef _SYS_SYSPROTO_H_ 1430 struct osigvec_args { 1431 int signum; 1432 struct sigvec *nsv; 1433 struct sigvec *osv; 1434 }; 1435 #endif 1436 /* ARGSUSED */ 1437 int 1438 osigvec(struct thread *td, struct osigvec_args *uap) 1439 { 1440 struct sigvec vec; 1441 struct sigaction nsa, osa; 1442 struct sigaction *nsap, *osap; 1443 int error; 1444 1445 if (uap->signum <= 0 || uap->signum >= ONSIG) 1446 return (EINVAL); 1447 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1448 osap = (uap->osv != NULL) ? &osa : NULL; 1449 if (nsap) { 1450 error = copyin(uap->nsv, &vec, sizeof(vec)); 1451 if (error) 1452 return (error); 1453 nsap->sa_handler = vec.sv_handler; 1454 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1455 nsap->sa_flags = vec.sv_flags; 1456 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1457 } 1458 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1459 if (osap && !error) { 1460 vec.sv_handler = osap->sa_handler; 1461 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1462 vec.sv_flags = osap->sa_flags; 1463 vec.sv_flags &= ~SA_NOCLDWAIT; 1464 vec.sv_flags ^= SA_RESTART; 1465 error = copyout(&vec, uap->osv, sizeof(vec)); 1466 } 1467 return (error); 1468 } 1469 1470 #ifndef _SYS_SYSPROTO_H_ 1471 struct osigblock_args { 1472 int mask; 1473 }; 1474 #endif 1475 int 1476 osigblock(struct thread *td, struct osigblock_args *uap) 1477 { 1478 sigset_t set, oset; 1479 1480 OSIG2SIG(uap->mask, set); 1481 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1482 SIG2OSIG(oset, td->td_retval[0]); 1483 return (0); 1484 } 1485 1486 #ifndef _SYS_SYSPROTO_H_ 1487 struct osigsetmask_args { 1488 int mask; 1489 }; 1490 #endif 1491 int 1492 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1493 { 1494 sigset_t set, oset; 1495 1496 OSIG2SIG(uap->mask, set); 1497 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1498 SIG2OSIG(oset, td->td_retval[0]); 1499 return (0); 1500 } 1501 #endif /* COMPAT_43 */ 1502 1503 /* 1504 * Suspend calling thread until signal, providing mask to be set in the 1505 * meantime. 1506 */ 1507 #ifndef _SYS_SYSPROTO_H_ 1508 struct sigsuspend_args { 1509 const sigset_t *sigmask; 1510 }; 1511 #endif 1512 /* ARGSUSED */ 1513 int 1514 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1515 { 1516 sigset_t mask; 1517 int error; 1518 1519 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1520 if (error) 1521 return (error); 1522 return (kern_sigsuspend(td, mask)); 1523 } 1524 1525 int 1526 kern_sigsuspend(struct thread *td, sigset_t mask) 1527 { 1528 struct proc *p = td->td_proc; 1529 int has_sig, sig; 1530 1531 /* 1532 * When returning from sigsuspend, we want 1533 * the old mask to be restored after the 1534 * signal handler has finished. Thus, we 1535 * save it here and mark the sigacts structure 1536 * to indicate this. 1537 */ 1538 PROC_LOCK(p); 1539 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1540 SIGPROCMASK_PROC_LOCKED); 1541 td->td_pflags |= TDP_OLDMASK; 1542 1543 /* 1544 * Process signals now. Otherwise, we can get spurious wakeup 1545 * due to signal entered process queue, but delivered to other 1546 * thread. But sigsuspend should return only on signal 1547 * delivery. 1548 */ 1549 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1550 for (has_sig = 0; !has_sig;) { 1551 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1552 0) == 0) 1553 /* void */; 1554 thread_suspend_check(0); 1555 mtx_lock(&p->p_sigacts->ps_mtx); 1556 while ((sig = cursig(td)) != 0) { 1557 KASSERT(sig >= 0, ("sig %d", sig)); 1558 has_sig += postsig(sig); 1559 } 1560 mtx_unlock(&p->p_sigacts->ps_mtx); 1561 1562 /* 1563 * If PTRACE_SCE or PTRACE_SCX were set after 1564 * userspace entered the syscall, return spurious 1565 * EINTR. 1566 */ 1567 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1568 has_sig += 1; 1569 } 1570 PROC_UNLOCK(p); 1571 td->td_errno = EINTR; 1572 td->td_pflags |= TDP_NERRNO; 1573 return (EJUSTRETURN); 1574 } 1575 1576 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1577 /* 1578 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1579 * convention: libc stub passes mask, not pointer, to save a copyin. 1580 */ 1581 #ifndef _SYS_SYSPROTO_H_ 1582 struct osigsuspend_args { 1583 osigset_t mask; 1584 }; 1585 #endif 1586 /* ARGSUSED */ 1587 int 1588 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1589 { 1590 sigset_t mask; 1591 1592 OSIG2SIG(uap->mask, mask); 1593 return (kern_sigsuspend(td, mask)); 1594 } 1595 #endif /* COMPAT_43 */ 1596 1597 #if defined(COMPAT_43) 1598 #ifndef _SYS_SYSPROTO_H_ 1599 struct osigstack_args { 1600 struct sigstack *nss; 1601 struct sigstack *oss; 1602 }; 1603 #endif 1604 /* ARGSUSED */ 1605 int 1606 osigstack(struct thread *td, struct osigstack_args *uap) 1607 { 1608 struct sigstack nss, oss; 1609 int error = 0; 1610 1611 if (uap->nss != NULL) { 1612 error = copyin(uap->nss, &nss, sizeof(nss)); 1613 if (error) 1614 return (error); 1615 } 1616 oss.ss_sp = td->td_sigstk.ss_sp; 1617 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1618 if (uap->nss != NULL) { 1619 td->td_sigstk.ss_sp = nss.ss_sp; 1620 td->td_sigstk.ss_size = 0; 1621 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1622 td->td_pflags |= TDP_ALTSTACK; 1623 } 1624 if (uap->oss != NULL) 1625 error = copyout(&oss, uap->oss, sizeof(oss)); 1626 1627 return (error); 1628 } 1629 #endif /* COMPAT_43 */ 1630 1631 #ifndef _SYS_SYSPROTO_H_ 1632 struct sigaltstack_args { 1633 stack_t *ss; 1634 stack_t *oss; 1635 }; 1636 #endif 1637 /* ARGSUSED */ 1638 int 1639 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1640 { 1641 stack_t ss, oss; 1642 int error; 1643 1644 if (uap->ss != NULL) { 1645 error = copyin(uap->ss, &ss, sizeof(ss)); 1646 if (error) 1647 return (error); 1648 } 1649 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1650 (uap->oss != NULL) ? &oss : NULL); 1651 if (error) 1652 return (error); 1653 if (uap->oss != NULL) 1654 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1655 return (error); 1656 } 1657 1658 int 1659 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1660 { 1661 struct proc *p = td->td_proc; 1662 int oonstack; 1663 1664 oonstack = sigonstack(cpu_getstack(td)); 1665 1666 if (oss != NULL) { 1667 *oss = td->td_sigstk; 1668 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1669 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1670 } 1671 1672 if (ss != NULL) { 1673 if (oonstack) 1674 return (EPERM); 1675 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1676 return (EINVAL); 1677 if (!(ss->ss_flags & SS_DISABLE)) { 1678 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1679 return (ENOMEM); 1680 1681 td->td_sigstk = *ss; 1682 td->td_pflags |= TDP_ALTSTACK; 1683 } else { 1684 td->td_pflags &= ~TDP_ALTSTACK; 1685 } 1686 } 1687 return (0); 1688 } 1689 1690 struct killpg1_ctx { 1691 struct thread *td; 1692 ksiginfo_t *ksi; 1693 int sig; 1694 bool sent; 1695 bool found; 1696 int ret; 1697 }; 1698 1699 static void 1700 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1701 { 1702 int err; 1703 1704 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1705 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1706 return; 1707 PROC_LOCK(p); 1708 err = p_cansignal(arg->td, p, arg->sig); 1709 if (err == 0 && arg->sig != 0) 1710 pksignal(p, arg->sig, arg->ksi); 1711 PROC_UNLOCK(p); 1712 if (err != ESRCH) 1713 arg->found = true; 1714 if (err == 0) 1715 arg->sent = true; 1716 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1717 arg->ret = err; 1718 } 1719 1720 /* 1721 * Common code for kill process group/broadcast kill. 1722 * cp is calling process. 1723 */ 1724 static int 1725 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1726 { 1727 struct proc *p; 1728 struct pgrp *pgrp; 1729 struct killpg1_ctx arg; 1730 1731 arg.td = td; 1732 arg.ksi = ksi; 1733 arg.sig = sig; 1734 arg.sent = false; 1735 arg.found = false; 1736 arg.ret = 0; 1737 if (all) { 1738 /* 1739 * broadcast 1740 */ 1741 sx_slock(&allproc_lock); 1742 FOREACH_PROC_IN_SYSTEM(p) { 1743 killpg1_sendsig(p, true, &arg); 1744 } 1745 sx_sunlock(&allproc_lock); 1746 } else { 1747 sx_slock(&proctree_lock); 1748 if (pgid == 0) { 1749 /* 1750 * zero pgid means send to my process group. 1751 */ 1752 pgrp = td->td_proc->p_pgrp; 1753 PGRP_LOCK(pgrp); 1754 } else { 1755 pgrp = pgfind(pgid); 1756 if (pgrp == NULL) { 1757 sx_sunlock(&proctree_lock); 1758 return (ESRCH); 1759 } 1760 } 1761 sx_sunlock(&proctree_lock); 1762 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1763 killpg1_sendsig(p, false, &arg); 1764 } 1765 PGRP_UNLOCK(pgrp); 1766 } 1767 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1768 if (arg.ret == 0 && !arg.sent) 1769 arg.ret = arg.found ? EPERM : ESRCH; 1770 return (arg.ret); 1771 } 1772 1773 #ifndef _SYS_SYSPROTO_H_ 1774 struct kill_args { 1775 int pid; 1776 int signum; 1777 }; 1778 #endif 1779 /* ARGSUSED */ 1780 int 1781 sys_kill(struct thread *td, struct kill_args *uap) 1782 { 1783 1784 return (kern_kill(td, uap->pid, uap->signum)); 1785 } 1786 1787 int 1788 kern_kill(struct thread *td, pid_t pid, int signum) 1789 { 1790 ksiginfo_t ksi; 1791 struct proc *p; 1792 int error; 1793 1794 /* 1795 * A process in capability mode can send signals only to himself. 1796 * The main rationale behind this is that abort(3) is implemented as 1797 * kill(getpid(), SIGABRT). 1798 */ 1799 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1800 return (ECAPMODE); 1801 1802 AUDIT_ARG_SIGNUM(signum); 1803 AUDIT_ARG_PID(pid); 1804 if ((u_int)signum > _SIG_MAXSIG) 1805 return (EINVAL); 1806 1807 ksiginfo_init(&ksi); 1808 ksi.ksi_signo = signum; 1809 ksi.ksi_code = SI_USER; 1810 ksi.ksi_pid = td->td_proc->p_pid; 1811 ksi.ksi_uid = td->td_ucred->cr_ruid; 1812 1813 if (pid > 0) { 1814 /* kill single process */ 1815 if ((p = pfind_any(pid)) == NULL) 1816 return (ESRCH); 1817 AUDIT_ARG_PROCESS(p); 1818 error = p_cansignal(td, p, signum); 1819 if (error == 0 && signum) 1820 pksignal(p, signum, &ksi); 1821 PROC_UNLOCK(p); 1822 return (error); 1823 } 1824 switch (pid) { 1825 case -1: /* broadcast signal */ 1826 return (killpg1(td, signum, 0, 1, &ksi)); 1827 case 0: /* signal own process group */ 1828 return (killpg1(td, signum, 0, 0, &ksi)); 1829 default: /* negative explicit process group */ 1830 return (killpg1(td, signum, -pid, 0, &ksi)); 1831 } 1832 /* NOTREACHED */ 1833 } 1834 1835 int 1836 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1837 { 1838 struct proc *p; 1839 int error; 1840 1841 AUDIT_ARG_SIGNUM(uap->signum); 1842 AUDIT_ARG_FD(uap->fd); 1843 if ((u_int)uap->signum > _SIG_MAXSIG) 1844 return (EINVAL); 1845 1846 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1847 if (error) 1848 return (error); 1849 AUDIT_ARG_PROCESS(p); 1850 error = p_cansignal(td, p, uap->signum); 1851 if (error == 0 && uap->signum) 1852 kern_psignal(p, uap->signum); 1853 PROC_UNLOCK(p); 1854 return (error); 1855 } 1856 1857 #if defined(COMPAT_43) 1858 #ifndef _SYS_SYSPROTO_H_ 1859 struct okillpg_args { 1860 int pgid; 1861 int signum; 1862 }; 1863 #endif 1864 /* ARGSUSED */ 1865 int 1866 okillpg(struct thread *td, struct okillpg_args *uap) 1867 { 1868 ksiginfo_t ksi; 1869 1870 AUDIT_ARG_SIGNUM(uap->signum); 1871 AUDIT_ARG_PID(uap->pgid); 1872 if ((u_int)uap->signum > _SIG_MAXSIG) 1873 return (EINVAL); 1874 1875 ksiginfo_init(&ksi); 1876 ksi.ksi_signo = uap->signum; 1877 ksi.ksi_code = SI_USER; 1878 ksi.ksi_pid = td->td_proc->p_pid; 1879 ksi.ksi_uid = td->td_ucred->cr_ruid; 1880 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1881 } 1882 #endif /* COMPAT_43 */ 1883 1884 #ifndef _SYS_SYSPROTO_H_ 1885 struct sigqueue_args { 1886 pid_t pid; 1887 int signum; 1888 /* union sigval */ void *value; 1889 }; 1890 #endif 1891 int 1892 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1893 { 1894 union sigval sv; 1895 1896 sv.sival_ptr = uap->value; 1897 1898 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1899 } 1900 1901 int 1902 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1903 { 1904 ksiginfo_t ksi; 1905 struct proc *p; 1906 int error; 1907 1908 if ((u_int)signum > _SIG_MAXSIG) 1909 return (EINVAL); 1910 1911 /* 1912 * Specification says sigqueue can only send signal to 1913 * single process. 1914 */ 1915 if (pid <= 0) 1916 return (EINVAL); 1917 1918 if ((p = pfind_any(pid)) == NULL) 1919 return (ESRCH); 1920 error = p_cansignal(td, p, signum); 1921 if (error == 0 && signum != 0) { 1922 ksiginfo_init(&ksi); 1923 ksi.ksi_flags = KSI_SIGQ; 1924 ksi.ksi_signo = signum; 1925 ksi.ksi_code = SI_QUEUE; 1926 ksi.ksi_pid = td->td_proc->p_pid; 1927 ksi.ksi_uid = td->td_ucred->cr_ruid; 1928 ksi.ksi_value = *value; 1929 error = pksignal(p, ksi.ksi_signo, &ksi); 1930 } 1931 PROC_UNLOCK(p); 1932 return (error); 1933 } 1934 1935 /* 1936 * Send a signal to a process group. 1937 */ 1938 void 1939 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1940 { 1941 struct pgrp *pgrp; 1942 1943 if (pgid != 0) { 1944 sx_slock(&proctree_lock); 1945 pgrp = pgfind(pgid); 1946 sx_sunlock(&proctree_lock); 1947 if (pgrp != NULL) { 1948 pgsignal(pgrp, sig, 0, ksi); 1949 PGRP_UNLOCK(pgrp); 1950 } 1951 } 1952 } 1953 1954 /* 1955 * Send a signal to a process group. If checktty is 1, 1956 * limit to members which have a controlling terminal. 1957 */ 1958 void 1959 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1960 { 1961 struct proc *p; 1962 1963 if (pgrp) { 1964 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1965 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1966 PROC_LOCK(p); 1967 if (p->p_state == PRS_NORMAL && 1968 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1969 pksignal(p, sig, ksi); 1970 PROC_UNLOCK(p); 1971 } 1972 } 1973 } 1974 1975 /* 1976 * Recalculate the signal mask and reset the signal disposition after 1977 * usermode frame for delivery is formed. Should be called after 1978 * mach-specific routine, because sysent->sv_sendsig() needs correct 1979 * ps_siginfo and signal mask. 1980 */ 1981 static void 1982 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1983 { 1984 sigset_t mask; 1985 1986 mtx_assert(&ps->ps_mtx, MA_OWNED); 1987 td->td_ru.ru_nsignals++; 1988 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1989 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1990 SIGADDSET(mask, sig); 1991 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1992 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1993 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1994 sigdflt(ps, sig); 1995 } 1996 1997 /* 1998 * Send a signal caused by a trap to the current thread. If it will be 1999 * caught immediately, deliver it with correct code. Otherwise, post it 2000 * normally. 2001 */ 2002 void 2003 trapsignal(struct thread *td, ksiginfo_t *ksi) 2004 { 2005 struct sigacts *ps; 2006 struct proc *p; 2007 sigset_t sigmask; 2008 int code, sig; 2009 2010 p = td->td_proc; 2011 sig = ksi->ksi_signo; 2012 code = ksi->ksi_code; 2013 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2014 2015 sigfastblock_fetch(td); 2016 PROC_LOCK(p); 2017 ps = p->p_sigacts; 2018 mtx_lock(&ps->ps_mtx); 2019 sigmask = td->td_sigmask; 2020 if (td->td_sigblock_val != 0) 2021 SIGSETOR(sigmask, fastblock_mask); 2022 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2023 !SIGISMEMBER(sigmask, sig)) { 2024 #ifdef KTRACE 2025 if (KTRPOINT(curthread, KTR_PSIG)) 2026 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2027 &td->td_sigmask, code); 2028 #endif 2029 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2030 ksi, &td->td_sigmask); 2031 postsig_done(sig, td, ps); 2032 mtx_unlock(&ps->ps_mtx); 2033 } else { 2034 /* 2035 * Avoid a possible infinite loop if the thread 2036 * masking the signal or process is ignoring the 2037 * signal. 2038 */ 2039 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2040 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2041 SIGDELSET(td->td_sigmask, sig); 2042 SIGDELSET(ps->ps_sigcatch, sig); 2043 SIGDELSET(ps->ps_sigignore, sig); 2044 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2045 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2046 td->td_sigblock_val = 0; 2047 } 2048 mtx_unlock(&ps->ps_mtx); 2049 p->p_sig = sig; /* XXX to verify code */ 2050 tdsendsignal(p, td, sig, ksi); 2051 } 2052 PROC_UNLOCK(p); 2053 } 2054 2055 static struct thread * 2056 sigtd(struct proc *p, int sig, bool fast_sigblock) 2057 { 2058 struct thread *td, *signal_td; 2059 2060 PROC_LOCK_ASSERT(p, MA_OWNED); 2061 MPASS(!fast_sigblock || p == curproc); 2062 2063 /* 2064 * Check if current thread can handle the signal without 2065 * switching context to another thread. 2066 */ 2067 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2068 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2069 return (curthread); 2070 signal_td = NULL; 2071 FOREACH_THREAD_IN_PROC(p, td) { 2072 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2073 td != curthread || td->td_sigblock_val == 0)) { 2074 signal_td = td; 2075 break; 2076 } 2077 } 2078 if (signal_td == NULL) 2079 signal_td = FIRST_THREAD_IN_PROC(p); 2080 return (signal_td); 2081 } 2082 2083 /* 2084 * Send the signal to the process. If the signal has an action, the action 2085 * is usually performed by the target process rather than the caller; we add 2086 * the signal to the set of pending signals for the process. 2087 * 2088 * Exceptions: 2089 * o When a stop signal is sent to a sleeping process that takes the 2090 * default action, the process is stopped without awakening it. 2091 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2092 * regardless of the signal action (eg, blocked or ignored). 2093 * 2094 * Other ignored signals are discarded immediately. 2095 * 2096 * NB: This function may be entered from the debugger via the "kill" DDB 2097 * command. There is little that can be done to mitigate the possibly messy 2098 * side effects of this unwise possibility. 2099 */ 2100 void 2101 kern_psignal(struct proc *p, int sig) 2102 { 2103 ksiginfo_t ksi; 2104 2105 ksiginfo_init(&ksi); 2106 ksi.ksi_signo = sig; 2107 ksi.ksi_code = SI_KERNEL; 2108 (void) tdsendsignal(p, NULL, sig, &ksi); 2109 } 2110 2111 int 2112 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2113 { 2114 2115 return (tdsendsignal(p, NULL, sig, ksi)); 2116 } 2117 2118 /* Utility function for finding a thread to send signal event to. */ 2119 int 2120 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2121 { 2122 struct thread *td; 2123 2124 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2125 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2126 if (td == NULL) 2127 return (ESRCH); 2128 *ttd = td; 2129 } else { 2130 *ttd = NULL; 2131 PROC_LOCK(p); 2132 } 2133 return (0); 2134 } 2135 2136 void 2137 tdsignal(struct thread *td, int sig) 2138 { 2139 ksiginfo_t ksi; 2140 2141 ksiginfo_init(&ksi); 2142 ksi.ksi_signo = sig; 2143 ksi.ksi_code = SI_KERNEL; 2144 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2145 } 2146 2147 void 2148 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2149 { 2150 2151 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2152 } 2153 2154 int 2155 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2156 { 2157 sig_t action; 2158 sigqueue_t *sigqueue; 2159 int prop; 2160 struct sigacts *ps; 2161 int intrval; 2162 int ret = 0; 2163 int wakeup_swapper; 2164 2165 MPASS(td == NULL || p == td->td_proc); 2166 PROC_LOCK_ASSERT(p, MA_OWNED); 2167 2168 if (!_SIG_VALID(sig)) 2169 panic("%s(): invalid signal %d", __func__, sig); 2170 2171 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2172 2173 /* 2174 * IEEE Std 1003.1-2001: return success when killing a zombie. 2175 */ 2176 if (p->p_state == PRS_ZOMBIE) { 2177 if (ksi && (ksi->ksi_flags & KSI_INS)) 2178 ksiginfo_tryfree(ksi); 2179 return (ret); 2180 } 2181 2182 ps = p->p_sigacts; 2183 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2184 prop = sigprop(sig); 2185 2186 if (td == NULL) { 2187 td = sigtd(p, sig, false); 2188 sigqueue = &p->p_sigqueue; 2189 } else 2190 sigqueue = &td->td_sigqueue; 2191 2192 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2193 2194 /* 2195 * If the signal is being ignored, 2196 * then we forget about it immediately. 2197 * (Note: we don't set SIGCONT in ps_sigignore, 2198 * and if it is set to SIG_IGN, 2199 * action will be SIG_DFL here.) 2200 */ 2201 mtx_lock(&ps->ps_mtx); 2202 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2203 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2204 2205 mtx_unlock(&ps->ps_mtx); 2206 if (ksi && (ksi->ksi_flags & KSI_INS)) 2207 ksiginfo_tryfree(ksi); 2208 return (ret); 2209 } 2210 if (SIGISMEMBER(td->td_sigmask, sig)) 2211 action = SIG_HOLD; 2212 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2213 action = SIG_CATCH; 2214 else 2215 action = SIG_DFL; 2216 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2217 intrval = EINTR; 2218 else 2219 intrval = ERESTART; 2220 mtx_unlock(&ps->ps_mtx); 2221 2222 if (prop & SIGPROP_CONT) 2223 sigqueue_delete_stopmask_proc(p); 2224 else if (prop & SIGPROP_STOP) { 2225 /* 2226 * If sending a tty stop signal to a member of an orphaned 2227 * process group, discard the signal here if the action 2228 * is default; don't stop the process below if sleeping, 2229 * and don't clear any pending SIGCONT. 2230 */ 2231 if ((prop & SIGPROP_TTYSTOP) && 2232 (p->p_pgrp->pg_jobc == 0) && 2233 (action == SIG_DFL)) { 2234 if (ksi && (ksi->ksi_flags & KSI_INS)) 2235 ksiginfo_tryfree(ksi); 2236 return (ret); 2237 } 2238 sigqueue_delete_proc(p, SIGCONT); 2239 if (p->p_flag & P_CONTINUED) { 2240 p->p_flag &= ~P_CONTINUED; 2241 PROC_LOCK(p->p_pptr); 2242 sigqueue_take(p->p_ksi); 2243 PROC_UNLOCK(p->p_pptr); 2244 } 2245 } 2246 2247 ret = sigqueue_add(sigqueue, sig, ksi); 2248 if (ret != 0) 2249 return (ret); 2250 signotify(td); 2251 /* 2252 * Defer further processing for signals which are held, 2253 * except that stopped processes must be continued by SIGCONT. 2254 */ 2255 if (action == SIG_HOLD && 2256 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2257 return (ret); 2258 2259 /* SIGKILL: Remove procfs STOPEVENTs. */ 2260 if (sig == SIGKILL) { 2261 /* from procfs_ioctl.c: PIOCBIC */ 2262 p->p_stops = 0; 2263 /* from procfs_ioctl.c: PIOCCONT */ 2264 p->p_step = 0; 2265 wakeup(&p->p_step); 2266 } 2267 wakeup_swapper = 0; 2268 2269 /* 2270 * Some signals have a process-wide effect and a per-thread 2271 * component. Most processing occurs when the process next 2272 * tries to cross the user boundary, however there are some 2273 * times when processing needs to be done immediately, such as 2274 * waking up threads so that they can cross the user boundary. 2275 * We try to do the per-process part here. 2276 */ 2277 if (P_SHOULDSTOP(p)) { 2278 KASSERT(!(p->p_flag & P_WEXIT), 2279 ("signal to stopped but exiting process")); 2280 if (sig == SIGKILL) { 2281 /* 2282 * If traced process is already stopped, 2283 * then no further action is necessary. 2284 */ 2285 if (p->p_flag & P_TRACED) 2286 goto out; 2287 /* 2288 * SIGKILL sets process running. 2289 * It will die elsewhere. 2290 * All threads must be restarted. 2291 */ 2292 p->p_flag &= ~P_STOPPED_SIG; 2293 goto runfast; 2294 } 2295 2296 if (prop & SIGPROP_CONT) { 2297 /* 2298 * If traced process is already stopped, 2299 * then no further action is necessary. 2300 */ 2301 if (p->p_flag & P_TRACED) 2302 goto out; 2303 /* 2304 * If SIGCONT is default (or ignored), we continue the 2305 * process but don't leave the signal in sigqueue as 2306 * it has no further action. If SIGCONT is held, we 2307 * continue the process and leave the signal in 2308 * sigqueue. If the process catches SIGCONT, let it 2309 * handle the signal itself. If it isn't waiting on 2310 * an event, it goes back to run state. 2311 * Otherwise, process goes back to sleep state. 2312 */ 2313 p->p_flag &= ~P_STOPPED_SIG; 2314 PROC_SLOCK(p); 2315 if (p->p_numthreads == p->p_suspcount) { 2316 PROC_SUNLOCK(p); 2317 p->p_flag |= P_CONTINUED; 2318 p->p_xsig = SIGCONT; 2319 PROC_LOCK(p->p_pptr); 2320 childproc_continued(p); 2321 PROC_UNLOCK(p->p_pptr); 2322 PROC_SLOCK(p); 2323 } 2324 if (action == SIG_DFL) { 2325 thread_unsuspend(p); 2326 PROC_SUNLOCK(p); 2327 sigqueue_delete(sigqueue, sig); 2328 goto out; 2329 } 2330 if (action == SIG_CATCH) { 2331 /* 2332 * The process wants to catch it so it needs 2333 * to run at least one thread, but which one? 2334 */ 2335 PROC_SUNLOCK(p); 2336 goto runfast; 2337 } 2338 /* 2339 * The signal is not ignored or caught. 2340 */ 2341 thread_unsuspend(p); 2342 PROC_SUNLOCK(p); 2343 goto out; 2344 } 2345 2346 if (prop & SIGPROP_STOP) { 2347 /* 2348 * If traced process is already stopped, 2349 * then no further action is necessary. 2350 */ 2351 if (p->p_flag & P_TRACED) 2352 goto out; 2353 /* 2354 * Already stopped, don't need to stop again 2355 * (If we did the shell could get confused). 2356 * Just make sure the signal STOP bit set. 2357 */ 2358 p->p_flag |= P_STOPPED_SIG; 2359 sigqueue_delete(sigqueue, sig); 2360 goto out; 2361 } 2362 2363 /* 2364 * All other kinds of signals: 2365 * If a thread is sleeping interruptibly, simulate a 2366 * wakeup so that when it is continued it will be made 2367 * runnable and can look at the signal. However, don't make 2368 * the PROCESS runnable, leave it stopped. 2369 * It may run a bit until it hits a thread_suspend_check(). 2370 */ 2371 PROC_SLOCK(p); 2372 thread_lock(td); 2373 if (TD_CAN_ABORT(td)) 2374 wakeup_swapper = sleepq_abort(td, intrval); 2375 else 2376 thread_unlock(td); 2377 PROC_SUNLOCK(p); 2378 goto out; 2379 /* 2380 * Mutexes are short lived. Threads waiting on them will 2381 * hit thread_suspend_check() soon. 2382 */ 2383 } else if (p->p_state == PRS_NORMAL) { 2384 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2385 tdsigwakeup(td, sig, action, intrval); 2386 goto out; 2387 } 2388 2389 MPASS(action == SIG_DFL); 2390 2391 if (prop & SIGPROP_STOP) { 2392 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2393 goto out; 2394 p->p_flag |= P_STOPPED_SIG; 2395 p->p_xsig = sig; 2396 PROC_SLOCK(p); 2397 wakeup_swapper = sig_suspend_threads(td, p, 1); 2398 if (p->p_numthreads == p->p_suspcount) { 2399 /* 2400 * only thread sending signal to another 2401 * process can reach here, if thread is sending 2402 * signal to its process, because thread does 2403 * not suspend itself here, p_numthreads 2404 * should never be equal to p_suspcount. 2405 */ 2406 thread_stopped(p); 2407 PROC_SUNLOCK(p); 2408 sigqueue_delete_proc(p, p->p_xsig); 2409 } else 2410 PROC_SUNLOCK(p); 2411 goto out; 2412 } 2413 } else { 2414 /* Not in "NORMAL" state. discard the signal. */ 2415 sigqueue_delete(sigqueue, sig); 2416 goto out; 2417 } 2418 2419 /* 2420 * The process is not stopped so we need to apply the signal to all the 2421 * running threads. 2422 */ 2423 runfast: 2424 tdsigwakeup(td, sig, action, intrval); 2425 PROC_SLOCK(p); 2426 thread_unsuspend(p); 2427 PROC_SUNLOCK(p); 2428 out: 2429 /* If we jump here, proc slock should not be owned. */ 2430 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2431 if (wakeup_swapper) 2432 kick_proc0(); 2433 2434 return (ret); 2435 } 2436 2437 /* 2438 * The force of a signal has been directed against a single 2439 * thread. We need to see what we can do about knocking it 2440 * out of any sleep it may be in etc. 2441 */ 2442 static void 2443 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2444 { 2445 struct proc *p = td->td_proc; 2446 int prop, wakeup_swapper; 2447 2448 PROC_LOCK_ASSERT(p, MA_OWNED); 2449 prop = sigprop(sig); 2450 2451 PROC_SLOCK(p); 2452 thread_lock(td); 2453 /* 2454 * Bring the priority of a thread up if we want it to get 2455 * killed in this lifetime. Be careful to avoid bumping the 2456 * priority of the idle thread, since we still allow to signal 2457 * kernel processes. 2458 */ 2459 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2460 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2461 sched_prio(td, PUSER); 2462 if (TD_ON_SLEEPQ(td)) { 2463 /* 2464 * If thread is sleeping uninterruptibly 2465 * we can't interrupt the sleep... the signal will 2466 * be noticed when the process returns through 2467 * trap() or syscall(). 2468 */ 2469 if ((td->td_flags & TDF_SINTR) == 0) 2470 goto out; 2471 /* 2472 * If SIGCONT is default (or ignored) and process is 2473 * asleep, we are finished; the process should not 2474 * be awakened. 2475 */ 2476 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2477 thread_unlock(td); 2478 PROC_SUNLOCK(p); 2479 sigqueue_delete(&p->p_sigqueue, sig); 2480 /* 2481 * It may be on either list in this state. 2482 * Remove from both for now. 2483 */ 2484 sigqueue_delete(&td->td_sigqueue, sig); 2485 return; 2486 } 2487 2488 /* 2489 * Don't awaken a sleeping thread for SIGSTOP if the 2490 * STOP signal is deferred. 2491 */ 2492 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2493 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2494 goto out; 2495 2496 /* 2497 * Give low priority threads a better chance to run. 2498 */ 2499 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2500 sched_prio(td, PUSER); 2501 2502 wakeup_swapper = sleepq_abort(td, intrval); 2503 PROC_SUNLOCK(p); 2504 if (wakeup_swapper) 2505 kick_proc0(); 2506 return; 2507 } 2508 2509 /* 2510 * Other states do nothing with the signal immediately, 2511 * other than kicking ourselves if we are running. 2512 * It will either never be noticed, or noticed very soon. 2513 */ 2514 #ifdef SMP 2515 if (TD_IS_RUNNING(td) && td != curthread) 2516 forward_signal(td); 2517 #endif 2518 2519 out: 2520 PROC_SUNLOCK(p); 2521 thread_unlock(td); 2522 } 2523 2524 static int 2525 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2526 { 2527 struct thread *td2; 2528 int wakeup_swapper; 2529 2530 PROC_LOCK_ASSERT(p, MA_OWNED); 2531 PROC_SLOCK_ASSERT(p, MA_OWNED); 2532 MPASS(sending || td == curthread); 2533 2534 wakeup_swapper = 0; 2535 FOREACH_THREAD_IN_PROC(p, td2) { 2536 thread_lock(td2); 2537 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2538 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2539 (td2->td_flags & TDF_SINTR)) { 2540 if (td2->td_flags & TDF_SBDRY) { 2541 /* 2542 * Once a thread is asleep with 2543 * TDF_SBDRY and without TDF_SERESTART 2544 * or TDF_SEINTR set, it should never 2545 * become suspended due to this check. 2546 */ 2547 KASSERT(!TD_IS_SUSPENDED(td2), 2548 ("thread with deferred stops suspended")); 2549 if (TD_SBDRY_INTR(td2)) { 2550 wakeup_swapper |= sleepq_abort(td2, 2551 TD_SBDRY_ERRNO(td2)); 2552 continue; 2553 } 2554 } else if (!TD_IS_SUSPENDED(td2)) 2555 thread_suspend_one(td2); 2556 } else if (!TD_IS_SUSPENDED(td2)) { 2557 if (sending || td != td2) 2558 td2->td_flags |= TDF_ASTPENDING; 2559 #ifdef SMP 2560 if (TD_IS_RUNNING(td2) && td2 != td) 2561 forward_signal(td2); 2562 #endif 2563 } 2564 thread_unlock(td2); 2565 } 2566 return (wakeup_swapper); 2567 } 2568 2569 /* 2570 * Stop the process for an event deemed interesting to the debugger. If si is 2571 * non-NULL, this is a signal exchange; the new signal requested by the 2572 * debugger will be returned for handling. If si is NULL, this is some other 2573 * type of interesting event. The debugger may request a signal be delivered in 2574 * that case as well, however it will be deferred until it can be handled. 2575 */ 2576 int 2577 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2578 { 2579 struct proc *p = td->td_proc; 2580 struct thread *td2; 2581 ksiginfo_t ksi; 2582 2583 PROC_LOCK_ASSERT(p, MA_OWNED); 2584 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2585 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2586 &p->p_mtx.lock_object, "Stopping for traced signal"); 2587 2588 td->td_xsig = sig; 2589 2590 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2591 td->td_dbgflags |= TDB_XSIG; 2592 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2593 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2594 PROC_SLOCK(p); 2595 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2596 if (P_KILLED(p)) { 2597 /* 2598 * Ensure that, if we've been PT_KILLed, the 2599 * exit status reflects that. Another thread 2600 * may also be in ptracestop(), having just 2601 * received the SIGKILL, but this thread was 2602 * unsuspended first. 2603 */ 2604 td->td_dbgflags &= ~TDB_XSIG; 2605 td->td_xsig = SIGKILL; 2606 p->p_ptevents = 0; 2607 break; 2608 } 2609 if (p->p_flag & P_SINGLE_EXIT && 2610 !(td->td_dbgflags & TDB_EXIT)) { 2611 /* 2612 * Ignore ptrace stops except for thread exit 2613 * events when the process exits. 2614 */ 2615 td->td_dbgflags &= ~TDB_XSIG; 2616 PROC_SUNLOCK(p); 2617 return (0); 2618 } 2619 2620 /* 2621 * Make wait(2) work. Ensure that right after the 2622 * attach, the thread which was decided to become the 2623 * leader of attach gets reported to the waiter. 2624 * Otherwise, just avoid overwriting another thread's 2625 * assignment to p_xthread. If another thread has 2626 * already set p_xthread, the current thread will get 2627 * a chance to report itself upon the next iteration. 2628 */ 2629 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2630 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2631 p->p_xthread == NULL)) { 2632 p->p_xsig = sig; 2633 p->p_xthread = td; 2634 2635 /* 2636 * If we are on sleepqueue already, 2637 * let sleepqueue code decide if it 2638 * needs to go sleep after attach. 2639 */ 2640 if (td->td_wchan == NULL) 2641 td->td_dbgflags &= ~TDB_FSTP; 2642 2643 p->p_flag2 &= ~P2_PTRACE_FSTP; 2644 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2645 sig_suspend_threads(td, p, 0); 2646 } 2647 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2648 td->td_dbgflags &= ~TDB_STOPATFORK; 2649 } 2650 stopme: 2651 thread_suspend_switch(td, p); 2652 if (p->p_xthread == td) 2653 p->p_xthread = NULL; 2654 if (!(p->p_flag & P_TRACED)) 2655 break; 2656 if (td->td_dbgflags & TDB_SUSPEND) { 2657 if (p->p_flag & P_SINGLE_EXIT) 2658 break; 2659 goto stopme; 2660 } 2661 } 2662 PROC_SUNLOCK(p); 2663 } 2664 2665 if (si != NULL && sig == td->td_xsig) { 2666 /* Parent wants us to take the original signal unchanged. */ 2667 si->ksi_flags |= KSI_HEAD; 2668 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2669 si->ksi_signo = 0; 2670 } else if (td->td_xsig != 0) { 2671 /* 2672 * If parent wants us to take a new signal, then it will leave 2673 * it in td->td_xsig; otherwise we just look for signals again. 2674 */ 2675 ksiginfo_init(&ksi); 2676 ksi.ksi_signo = td->td_xsig; 2677 ksi.ksi_flags |= KSI_PTRACE; 2678 td2 = sigtd(p, td->td_xsig, false); 2679 tdsendsignal(p, td2, td->td_xsig, &ksi); 2680 if (td != td2) 2681 return (0); 2682 } 2683 2684 return (td->td_xsig); 2685 } 2686 2687 static void 2688 reschedule_signals(struct proc *p, sigset_t block, int flags) 2689 { 2690 struct sigacts *ps; 2691 struct thread *td; 2692 int sig; 2693 bool fastblk, pslocked; 2694 2695 PROC_LOCK_ASSERT(p, MA_OWNED); 2696 ps = p->p_sigacts; 2697 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2698 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2699 if (SIGISEMPTY(p->p_siglist)) 2700 return; 2701 SIGSETAND(block, p->p_siglist); 2702 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2703 while ((sig = sig_ffs(&block)) != 0) { 2704 SIGDELSET(block, sig); 2705 td = sigtd(p, sig, fastblk); 2706 2707 /* 2708 * If sigtd() selected us despite sigfastblock is 2709 * blocking, do not activate AST or wake us, to avoid 2710 * loop in AST handler. 2711 */ 2712 if (fastblk && td == curthread) 2713 continue; 2714 2715 signotify(td); 2716 if (!pslocked) 2717 mtx_lock(&ps->ps_mtx); 2718 if (p->p_flag & P_TRACED || 2719 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2720 !SIGISMEMBER(td->td_sigmask, sig))) { 2721 tdsigwakeup(td, sig, SIG_CATCH, 2722 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2723 ERESTART)); 2724 } 2725 if (!pslocked) 2726 mtx_unlock(&ps->ps_mtx); 2727 } 2728 } 2729 2730 void 2731 tdsigcleanup(struct thread *td) 2732 { 2733 struct proc *p; 2734 sigset_t unblocked; 2735 2736 p = td->td_proc; 2737 PROC_LOCK_ASSERT(p, MA_OWNED); 2738 2739 sigqueue_flush(&td->td_sigqueue); 2740 if (p->p_numthreads == 1) 2741 return; 2742 2743 /* 2744 * Since we cannot handle signals, notify signal post code 2745 * about this by filling the sigmask. 2746 * 2747 * Also, if needed, wake up thread(s) that do not block the 2748 * same signals as the exiting thread, since the thread might 2749 * have been selected for delivery and woken up. 2750 */ 2751 SIGFILLSET(unblocked); 2752 SIGSETNAND(unblocked, td->td_sigmask); 2753 SIGFILLSET(td->td_sigmask); 2754 reschedule_signals(p, unblocked, 0); 2755 2756 } 2757 2758 static int 2759 sigdeferstop_curr_flags(int cflags) 2760 { 2761 2762 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2763 (cflags & TDF_SBDRY) != 0); 2764 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2765 } 2766 2767 /* 2768 * Defer the delivery of SIGSTOP for the current thread, according to 2769 * the requested mode. Returns previous flags, which must be restored 2770 * by sigallowstop(). 2771 * 2772 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2773 * cleared by the current thread, which allow the lock-less read-only 2774 * accesses below. 2775 */ 2776 int 2777 sigdeferstop_impl(int mode) 2778 { 2779 struct thread *td; 2780 int cflags, nflags; 2781 2782 td = curthread; 2783 cflags = sigdeferstop_curr_flags(td->td_flags); 2784 switch (mode) { 2785 case SIGDEFERSTOP_NOP: 2786 nflags = cflags; 2787 break; 2788 case SIGDEFERSTOP_OFF: 2789 nflags = 0; 2790 break; 2791 case SIGDEFERSTOP_SILENT: 2792 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2793 break; 2794 case SIGDEFERSTOP_EINTR: 2795 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2796 break; 2797 case SIGDEFERSTOP_ERESTART: 2798 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2799 break; 2800 default: 2801 panic("sigdeferstop: invalid mode %x", mode); 2802 break; 2803 } 2804 if (cflags == nflags) 2805 return (SIGDEFERSTOP_VAL_NCHG); 2806 thread_lock(td); 2807 td->td_flags = (td->td_flags & ~cflags) | nflags; 2808 thread_unlock(td); 2809 return (cflags); 2810 } 2811 2812 /* 2813 * Restores the STOP handling mode, typically permitting the delivery 2814 * of SIGSTOP for the current thread. This does not immediately 2815 * suspend if a stop was posted. Instead, the thread will suspend 2816 * either via ast() or a subsequent interruptible sleep. 2817 */ 2818 void 2819 sigallowstop_impl(int prev) 2820 { 2821 struct thread *td; 2822 int cflags; 2823 2824 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2825 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2826 ("sigallowstop: incorrect previous mode %x", prev)); 2827 td = curthread; 2828 cflags = sigdeferstop_curr_flags(td->td_flags); 2829 if (cflags != prev) { 2830 thread_lock(td); 2831 td->td_flags = (td->td_flags & ~cflags) | prev; 2832 thread_unlock(td); 2833 } 2834 } 2835 2836 /* 2837 * If the current process has received a signal (should be caught or cause 2838 * termination, should interrupt current syscall), return the signal number. 2839 * Stop signals with default action are processed immediately, then cleared; 2840 * they aren't returned. This is checked after each entry to the system for 2841 * a syscall or trap (though this can usually be done without calling issignal 2842 * by checking the pending signal masks in cursig.) The normal call 2843 * sequence is 2844 * 2845 * while (sig = cursig(curthread)) 2846 * postsig(sig); 2847 */ 2848 static int 2849 issignal(struct thread *td) 2850 { 2851 struct proc *p; 2852 struct sigacts *ps; 2853 struct sigqueue *queue; 2854 sigset_t sigpending; 2855 ksiginfo_t ksi; 2856 int prop, sig, traced; 2857 2858 p = td->td_proc; 2859 ps = p->p_sigacts; 2860 mtx_assert(&ps->ps_mtx, MA_OWNED); 2861 PROC_LOCK_ASSERT(p, MA_OWNED); 2862 for (;;) { 2863 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2864 2865 sigpending = td->td_sigqueue.sq_signals; 2866 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2867 SIGSETNAND(sigpending, td->td_sigmask); 2868 2869 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2870 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2871 SIG_STOPSIGMASK(sigpending); 2872 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2873 return (0); 2874 2875 /* 2876 * Do fast sigblock if requested by usermode. Since 2877 * we do know that there was a signal pending at this 2878 * point, set the FAST_SIGBLOCK_PEND as indicator for 2879 * usermode to perform a dummy call to 2880 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2881 * delivery of postponed pending signal. 2882 */ 2883 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2884 if (td->td_sigblock_val != 0) 2885 SIGSETNAND(sigpending, fastblock_mask); 2886 if (SIGISEMPTY(sigpending)) { 2887 td->td_pflags |= TDP_SIGFASTPENDING; 2888 return (0); 2889 } 2890 } 2891 2892 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2893 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2894 SIGISMEMBER(sigpending, SIGSTOP)) { 2895 /* 2896 * If debugger just attached, always consume 2897 * SIGSTOP from ptrace(PT_ATTACH) first, to 2898 * execute the debugger attach ritual in 2899 * order. 2900 */ 2901 sig = SIGSTOP; 2902 td->td_dbgflags |= TDB_FSTP; 2903 } else { 2904 sig = sig_ffs(&sigpending); 2905 } 2906 2907 if (p->p_stops & S_SIG) { 2908 mtx_unlock(&ps->ps_mtx); 2909 stopevent(p, S_SIG, sig); 2910 mtx_lock(&ps->ps_mtx); 2911 } 2912 2913 /* 2914 * We should see pending but ignored signals 2915 * only if P_TRACED was on when they were posted. 2916 */ 2917 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2918 sigqueue_delete(&td->td_sigqueue, sig); 2919 sigqueue_delete(&p->p_sigqueue, sig); 2920 continue; 2921 } 2922 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2923 /* 2924 * If traced, always stop. 2925 * Remove old signal from queue before the stop. 2926 * XXX shrug off debugger, it causes siginfo to 2927 * be thrown away. 2928 */ 2929 queue = &td->td_sigqueue; 2930 ksiginfo_init(&ksi); 2931 if (sigqueue_get(queue, sig, &ksi) == 0) { 2932 queue = &p->p_sigqueue; 2933 sigqueue_get(queue, sig, &ksi); 2934 } 2935 td->td_si = ksi.ksi_info; 2936 2937 mtx_unlock(&ps->ps_mtx); 2938 sig = ptracestop(td, sig, &ksi); 2939 mtx_lock(&ps->ps_mtx); 2940 2941 td->td_si.si_signo = 0; 2942 2943 /* 2944 * Keep looking if the debugger discarded or 2945 * replaced the signal. 2946 */ 2947 if (sig == 0) 2948 continue; 2949 2950 /* 2951 * If the signal became masked, re-queue it. 2952 */ 2953 if (SIGISMEMBER(td->td_sigmask, sig)) { 2954 ksi.ksi_flags |= KSI_HEAD; 2955 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2956 continue; 2957 } 2958 2959 /* 2960 * If the traced bit got turned off, requeue 2961 * the signal and go back up to the top to 2962 * rescan signals. This ensures that p_sig* 2963 * and p_sigact are consistent. 2964 */ 2965 if ((p->p_flag & P_TRACED) == 0) { 2966 ksi.ksi_flags |= KSI_HEAD; 2967 sigqueue_add(queue, sig, &ksi); 2968 continue; 2969 } 2970 } 2971 2972 prop = sigprop(sig); 2973 2974 /* 2975 * Decide whether the signal should be returned. 2976 * Return the signal's number, or fall through 2977 * to clear it from the pending mask. 2978 */ 2979 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2980 2981 case (intptr_t)SIG_DFL: 2982 /* 2983 * Don't take default actions on system processes. 2984 */ 2985 if (p->p_pid <= 1) { 2986 #ifdef DIAGNOSTIC 2987 /* 2988 * Are you sure you want to ignore SIGSEGV 2989 * in init? XXX 2990 */ 2991 printf("Process (pid %lu) got signal %d\n", 2992 (u_long)p->p_pid, sig); 2993 #endif 2994 break; /* == ignore */ 2995 } 2996 /* 2997 * If there is a pending stop signal to process with 2998 * default action, stop here, then clear the signal. 2999 * Traced or exiting processes should ignore stops. 3000 * Additionally, a member of an orphaned process group 3001 * should ignore tty stops. 3002 */ 3003 if (prop & SIGPROP_STOP) { 3004 if (p->p_flag & 3005 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 3006 (p->p_pgrp->pg_jobc == 0 && 3007 prop & SIGPROP_TTYSTOP)) 3008 break; /* == ignore */ 3009 if (TD_SBDRY_INTR(td)) { 3010 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3011 ("lost TDF_SBDRY")); 3012 return (-1); 3013 } 3014 mtx_unlock(&ps->ps_mtx); 3015 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3016 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3017 sigqueue_delete(&td->td_sigqueue, sig); 3018 sigqueue_delete(&p->p_sigqueue, sig); 3019 p->p_flag |= P_STOPPED_SIG; 3020 p->p_xsig = sig; 3021 PROC_SLOCK(p); 3022 sig_suspend_threads(td, p, 0); 3023 thread_suspend_switch(td, p); 3024 PROC_SUNLOCK(p); 3025 mtx_lock(&ps->ps_mtx); 3026 goto next; 3027 } else if (prop & SIGPROP_IGNORE) { 3028 /* 3029 * Except for SIGCONT, shouldn't get here. 3030 * Default action is to ignore; drop it. 3031 */ 3032 break; /* == ignore */ 3033 } else 3034 return (sig); 3035 /*NOTREACHED*/ 3036 3037 case (intptr_t)SIG_IGN: 3038 /* 3039 * Masking above should prevent us ever trying 3040 * to take action on an ignored signal other 3041 * than SIGCONT, unless process is traced. 3042 */ 3043 if ((prop & SIGPROP_CONT) == 0 && 3044 (p->p_flag & P_TRACED) == 0) 3045 printf("issignal\n"); 3046 break; /* == ignore */ 3047 3048 default: 3049 /* 3050 * This signal has an action, let 3051 * postsig() process it. 3052 */ 3053 return (sig); 3054 } 3055 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3056 sigqueue_delete(&p->p_sigqueue, sig); 3057 next:; 3058 } 3059 /* NOTREACHED */ 3060 } 3061 3062 void 3063 thread_stopped(struct proc *p) 3064 { 3065 int n; 3066 3067 PROC_LOCK_ASSERT(p, MA_OWNED); 3068 PROC_SLOCK_ASSERT(p, MA_OWNED); 3069 n = p->p_suspcount; 3070 if (p == curproc) 3071 n++; 3072 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3073 PROC_SUNLOCK(p); 3074 p->p_flag &= ~P_WAITED; 3075 PROC_LOCK(p->p_pptr); 3076 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3077 CLD_TRAPPED : CLD_STOPPED); 3078 PROC_UNLOCK(p->p_pptr); 3079 PROC_SLOCK(p); 3080 } 3081 } 3082 3083 /* 3084 * Take the action for the specified signal 3085 * from the current set of pending signals. 3086 */ 3087 int 3088 postsig(int sig) 3089 { 3090 struct thread *td; 3091 struct proc *p; 3092 struct sigacts *ps; 3093 sig_t action; 3094 ksiginfo_t ksi; 3095 sigset_t returnmask; 3096 3097 KASSERT(sig != 0, ("postsig")); 3098 3099 td = curthread; 3100 p = td->td_proc; 3101 PROC_LOCK_ASSERT(p, MA_OWNED); 3102 ps = p->p_sigacts; 3103 mtx_assert(&ps->ps_mtx, MA_OWNED); 3104 ksiginfo_init(&ksi); 3105 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3106 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3107 return (0); 3108 ksi.ksi_signo = sig; 3109 if (ksi.ksi_code == SI_TIMER) 3110 itimer_accept(p, ksi.ksi_timerid, &ksi); 3111 action = ps->ps_sigact[_SIG_IDX(sig)]; 3112 #ifdef KTRACE 3113 if (KTRPOINT(td, KTR_PSIG)) 3114 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3115 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3116 #endif 3117 if ((p->p_stops & S_SIG) != 0) { 3118 mtx_unlock(&ps->ps_mtx); 3119 stopevent(p, S_SIG, sig); 3120 mtx_lock(&ps->ps_mtx); 3121 } 3122 3123 if (action == SIG_DFL) { 3124 /* 3125 * Default action, where the default is to kill 3126 * the process. (Other cases were ignored above.) 3127 */ 3128 mtx_unlock(&ps->ps_mtx); 3129 proc_td_siginfo_capture(td, &ksi.ksi_info); 3130 sigexit(td, sig); 3131 /* NOTREACHED */ 3132 } else { 3133 /* 3134 * If we get here, the signal must be caught. 3135 */ 3136 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3137 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3138 ("postsig action: blocked sig %d", sig)); 3139 3140 /* 3141 * Set the new mask value and also defer further 3142 * occurrences of this signal. 3143 * 3144 * Special case: user has done a sigsuspend. Here the 3145 * current mask is not of interest, but rather the 3146 * mask from before the sigsuspend is what we want 3147 * restored after the signal processing is completed. 3148 */ 3149 if (td->td_pflags & TDP_OLDMASK) { 3150 returnmask = td->td_oldsigmask; 3151 td->td_pflags &= ~TDP_OLDMASK; 3152 } else 3153 returnmask = td->td_sigmask; 3154 3155 if (p->p_sig == sig) { 3156 p->p_sig = 0; 3157 } 3158 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3159 postsig_done(sig, td, ps); 3160 } 3161 return (1); 3162 } 3163 3164 void 3165 proc_wkilled(struct proc *p) 3166 { 3167 3168 PROC_LOCK_ASSERT(p, MA_OWNED); 3169 if ((p->p_flag & P_WKILLED) == 0) { 3170 p->p_flag |= P_WKILLED; 3171 /* 3172 * Notify swapper that there is a process to swap in. 3173 * The notification is racy, at worst it would take 10 3174 * seconds for the swapper process to notice. 3175 */ 3176 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3177 wakeup(&proc0); 3178 } 3179 } 3180 3181 /* 3182 * Kill the current process for stated reason. 3183 */ 3184 void 3185 killproc(struct proc *p, const char *why) 3186 { 3187 3188 PROC_LOCK_ASSERT(p, MA_OWNED); 3189 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3190 p->p_comm); 3191 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3192 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3193 p->p_ucred->cr_uid, why); 3194 proc_wkilled(p); 3195 kern_psignal(p, SIGKILL); 3196 } 3197 3198 /* 3199 * Force the current process to exit with the specified signal, dumping core 3200 * if appropriate. We bypass the normal tests for masked and caught signals, 3201 * allowing unrecoverable failures to terminate the process without changing 3202 * signal state. Mark the accounting record with the signal termination. 3203 * If dumping core, save the signal number for the debugger. Calls exit and 3204 * does not return. 3205 */ 3206 void 3207 sigexit(struct thread *td, int sig) 3208 { 3209 struct proc *p = td->td_proc; 3210 3211 PROC_LOCK_ASSERT(p, MA_OWNED); 3212 p->p_acflag |= AXSIG; 3213 /* 3214 * We must be single-threading to generate a core dump. This 3215 * ensures that the registers in the core file are up-to-date. 3216 * Also, the ELF dump handler assumes that the thread list doesn't 3217 * change out from under it. 3218 * 3219 * XXX If another thread attempts to single-thread before us 3220 * (e.g. via fork()), we won't get a dump at all. 3221 */ 3222 if ((sigprop(sig) & SIGPROP_CORE) && 3223 thread_single(p, SINGLE_NO_EXIT) == 0) { 3224 p->p_sig = sig; 3225 /* 3226 * Log signals which would cause core dumps 3227 * (Log as LOG_INFO to appease those who don't want 3228 * these messages.) 3229 * XXX : Todo, as well as euid, write out ruid too 3230 * Note that coredump() drops proc lock. 3231 */ 3232 if (coredump(td) == 0) 3233 sig |= WCOREFLAG; 3234 if (kern_logsigexit) 3235 log(LOG_INFO, 3236 "pid %d (%s), jid %d, uid %d: exited on " 3237 "signal %d%s\n", p->p_pid, p->p_comm, 3238 p->p_ucred->cr_prison->pr_id, 3239 td->td_ucred->cr_uid, 3240 sig &~ WCOREFLAG, 3241 sig & WCOREFLAG ? " (core dumped)" : ""); 3242 } else 3243 PROC_UNLOCK(p); 3244 exit1(td, 0, sig); 3245 /* NOTREACHED */ 3246 } 3247 3248 /* 3249 * Send queued SIGCHLD to parent when child process's state 3250 * is changed. 3251 */ 3252 static void 3253 sigparent(struct proc *p, int reason, int status) 3254 { 3255 PROC_LOCK_ASSERT(p, MA_OWNED); 3256 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3257 3258 if (p->p_ksi != NULL) { 3259 p->p_ksi->ksi_signo = SIGCHLD; 3260 p->p_ksi->ksi_code = reason; 3261 p->p_ksi->ksi_status = status; 3262 p->p_ksi->ksi_pid = p->p_pid; 3263 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3264 if (KSI_ONQ(p->p_ksi)) 3265 return; 3266 } 3267 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3268 } 3269 3270 static void 3271 childproc_jobstate(struct proc *p, int reason, int sig) 3272 { 3273 struct sigacts *ps; 3274 3275 PROC_LOCK_ASSERT(p, MA_OWNED); 3276 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3277 3278 /* 3279 * Wake up parent sleeping in kern_wait(), also send 3280 * SIGCHLD to parent, but SIGCHLD does not guarantee 3281 * that parent will awake, because parent may masked 3282 * the signal. 3283 */ 3284 p->p_pptr->p_flag |= P_STATCHILD; 3285 wakeup(p->p_pptr); 3286 3287 ps = p->p_pptr->p_sigacts; 3288 mtx_lock(&ps->ps_mtx); 3289 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3290 mtx_unlock(&ps->ps_mtx); 3291 sigparent(p, reason, sig); 3292 } else 3293 mtx_unlock(&ps->ps_mtx); 3294 } 3295 3296 void 3297 childproc_stopped(struct proc *p, int reason) 3298 { 3299 3300 childproc_jobstate(p, reason, p->p_xsig); 3301 } 3302 3303 void 3304 childproc_continued(struct proc *p) 3305 { 3306 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3307 } 3308 3309 void 3310 childproc_exited(struct proc *p) 3311 { 3312 int reason, status; 3313 3314 if (WCOREDUMP(p->p_xsig)) { 3315 reason = CLD_DUMPED; 3316 status = WTERMSIG(p->p_xsig); 3317 } else if (WIFSIGNALED(p->p_xsig)) { 3318 reason = CLD_KILLED; 3319 status = WTERMSIG(p->p_xsig); 3320 } else { 3321 reason = CLD_EXITED; 3322 status = p->p_xexit; 3323 } 3324 /* 3325 * XXX avoid calling wakeup(p->p_pptr), the work is 3326 * done in exit1(). 3327 */ 3328 sigparent(p, reason, status); 3329 } 3330 3331 #define MAX_NUM_CORE_FILES 100000 3332 #ifndef NUM_CORE_FILES 3333 #define NUM_CORE_FILES 5 3334 #endif 3335 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3336 static int num_cores = NUM_CORE_FILES; 3337 3338 static int 3339 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3340 { 3341 int error; 3342 int new_val; 3343 3344 new_val = num_cores; 3345 error = sysctl_handle_int(oidp, &new_val, 0, req); 3346 if (error != 0 || req->newptr == NULL) 3347 return (error); 3348 if (new_val > MAX_NUM_CORE_FILES) 3349 new_val = MAX_NUM_CORE_FILES; 3350 if (new_val < 0) 3351 new_val = 0; 3352 num_cores = new_val; 3353 return (0); 3354 } 3355 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3356 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3357 sysctl_debug_num_cores_check, "I", 3358 "Maximum number of generated process corefiles while using index format"); 3359 3360 #define GZIP_SUFFIX ".gz" 3361 #define ZSTD_SUFFIX ".zst" 3362 3363 int compress_user_cores = 0; 3364 3365 static int 3366 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3367 { 3368 int error, val; 3369 3370 val = compress_user_cores; 3371 error = sysctl_handle_int(oidp, &val, 0, req); 3372 if (error != 0 || req->newptr == NULL) 3373 return (error); 3374 if (val != 0 && !compressor_avail(val)) 3375 return (EINVAL); 3376 compress_user_cores = val; 3377 return (error); 3378 } 3379 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3380 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3381 sysctl_compress_user_cores, "I", 3382 "Enable compression of user corefiles (" 3383 __XSTRING(COMPRESS_GZIP) " = gzip, " 3384 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3385 3386 int compress_user_cores_level = 6; 3387 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3388 &compress_user_cores_level, 0, 3389 "Corefile compression level"); 3390 3391 /* 3392 * Protect the access to corefilename[] by allproc_lock. 3393 */ 3394 #define corefilename_lock allproc_lock 3395 3396 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3397 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3398 3399 static int 3400 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3401 { 3402 int error; 3403 3404 sx_xlock(&corefilename_lock); 3405 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3406 req); 3407 sx_xunlock(&corefilename_lock); 3408 3409 return (error); 3410 } 3411 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3412 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3413 "Process corefile name format string"); 3414 3415 static void 3416 vnode_close_locked(struct thread *td, struct vnode *vp) 3417 { 3418 3419 VOP_UNLOCK(vp); 3420 vn_close(vp, FWRITE, td->td_ucred, td); 3421 } 3422 3423 /* 3424 * If the core format has a %I in it, then we need to check 3425 * for existing corefiles before defining a name. 3426 * To do this we iterate over 0..ncores to find a 3427 * non-existing core file name to use. If all core files are 3428 * already used we choose the oldest one. 3429 */ 3430 static int 3431 corefile_open_last(struct thread *td, char *name, int indexpos, 3432 int indexlen, int ncores, struct vnode **vpp) 3433 { 3434 struct vnode *oldvp, *nextvp, *vp; 3435 struct vattr vattr; 3436 struct nameidata nd; 3437 int error, i, flags, oflags, cmode; 3438 char ch; 3439 struct timespec lasttime; 3440 3441 nextvp = oldvp = NULL; 3442 cmode = S_IRUSR | S_IWUSR; 3443 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3444 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3445 3446 for (i = 0; i < ncores; i++) { 3447 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3448 3449 ch = name[indexpos + indexlen]; 3450 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3451 i); 3452 name[indexpos + indexlen] = ch; 3453 3454 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3455 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3456 NULL); 3457 if (error != 0) 3458 break; 3459 3460 vp = nd.ni_vp; 3461 NDFREE(&nd, NDF_ONLY_PNBUF); 3462 if ((flags & O_CREAT) == O_CREAT) { 3463 nextvp = vp; 3464 break; 3465 } 3466 3467 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3468 if (error != 0) { 3469 vnode_close_locked(td, vp); 3470 break; 3471 } 3472 3473 if (oldvp == NULL || 3474 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3475 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3476 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3477 if (oldvp != NULL) 3478 vnode_close_locked(td, oldvp); 3479 oldvp = vp; 3480 lasttime = vattr.va_mtime; 3481 } else { 3482 vnode_close_locked(td, vp); 3483 } 3484 } 3485 3486 if (oldvp != NULL) { 3487 if (nextvp == NULL) { 3488 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3489 error = EFAULT; 3490 vnode_close_locked(td, oldvp); 3491 } else { 3492 nextvp = oldvp; 3493 } 3494 } else { 3495 vnode_close_locked(td, oldvp); 3496 } 3497 } 3498 if (error != 0) { 3499 if (nextvp != NULL) 3500 vnode_close_locked(td, oldvp); 3501 } else { 3502 *vpp = nextvp; 3503 } 3504 3505 return (error); 3506 } 3507 3508 /* 3509 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3510 * Expand the name described in corefilename, using name, uid, and pid 3511 * and open/create core file. 3512 * corefilename is a printf-like string, with three format specifiers: 3513 * %N name of process ("name") 3514 * %P process id (pid) 3515 * %U user id (uid) 3516 * For example, "%N.core" is the default; they can be disabled completely 3517 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3518 * This is controlled by the sysctl variable kern.corefile (see above). 3519 */ 3520 static int 3521 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3522 int compress, int signum, struct vnode **vpp, char **namep) 3523 { 3524 struct sbuf sb; 3525 struct nameidata nd; 3526 const char *format; 3527 char *hostname, *name; 3528 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3529 3530 hostname = NULL; 3531 format = corefilename; 3532 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3533 indexlen = 0; 3534 indexpos = -1; 3535 ncores = num_cores; 3536 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3537 sx_slock(&corefilename_lock); 3538 for (i = 0; format[i] != '\0'; i++) { 3539 switch (format[i]) { 3540 case '%': /* Format character */ 3541 i++; 3542 switch (format[i]) { 3543 case '%': 3544 sbuf_putc(&sb, '%'); 3545 break; 3546 case 'H': /* hostname */ 3547 if (hostname == NULL) { 3548 hostname = malloc(MAXHOSTNAMELEN, 3549 M_TEMP, M_WAITOK); 3550 } 3551 getcredhostname(td->td_ucred, hostname, 3552 MAXHOSTNAMELEN); 3553 sbuf_printf(&sb, "%s", hostname); 3554 break; 3555 case 'I': /* autoincrementing index */ 3556 if (indexpos != -1) { 3557 sbuf_printf(&sb, "%%I"); 3558 break; 3559 } 3560 3561 indexpos = sbuf_len(&sb); 3562 sbuf_printf(&sb, "%u", ncores - 1); 3563 indexlen = sbuf_len(&sb) - indexpos; 3564 break; 3565 case 'N': /* process name */ 3566 sbuf_printf(&sb, "%s", comm); 3567 break; 3568 case 'P': /* process id */ 3569 sbuf_printf(&sb, "%u", pid); 3570 break; 3571 case 'S': /* signal number */ 3572 sbuf_printf(&sb, "%i", signum); 3573 break; 3574 case 'U': /* user id */ 3575 sbuf_printf(&sb, "%u", uid); 3576 break; 3577 default: 3578 log(LOG_ERR, 3579 "Unknown format character %c in " 3580 "corename `%s'\n", format[i], format); 3581 break; 3582 } 3583 break; 3584 default: 3585 sbuf_putc(&sb, format[i]); 3586 break; 3587 } 3588 } 3589 sx_sunlock(&corefilename_lock); 3590 free(hostname, M_TEMP); 3591 if (compress == COMPRESS_GZIP) 3592 sbuf_printf(&sb, GZIP_SUFFIX); 3593 else if (compress == COMPRESS_ZSTD) 3594 sbuf_printf(&sb, ZSTD_SUFFIX); 3595 if (sbuf_error(&sb) != 0) { 3596 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3597 "long\n", (long)pid, comm, (u_long)uid); 3598 sbuf_delete(&sb); 3599 free(name, M_TEMP); 3600 return (ENOMEM); 3601 } 3602 sbuf_finish(&sb); 3603 sbuf_delete(&sb); 3604 3605 if (indexpos != -1) { 3606 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3607 vpp); 3608 if (error != 0) { 3609 log(LOG_ERR, 3610 "pid %d (%s), uid (%u): Path `%s' failed " 3611 "on initial open test, error = %d\n", 3612 pid, comm, uid, name, error); 3613 } 3614 } else { 3615 cmode = S_IRUSR | S_IWUSR; 3616 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3617 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3618 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3619 if ((td->td_proc->p_flag & P_SUGID) != 0) 3620 flags |= O_EXCL; 3621 3622 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3623 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3624 NULL); 3625 if (error == 0) { 3626 *vpp = nd.ni_vp; 3627 NDFREE(&nd, NDF_ONLY_PNBUF); 3628 } 3629 } 3630 3631 if (error != 0) { 3632 #ifdef AUDIT 3633 audit_proc_coredump(td, name, error); 3634 #endif 3635 free(name, M_TEMP); 3636 return (error); 3637 } 3638 *namep = name; 3639 return (0); 3640 } 3641 3642 /* 3643 * Dump a process' core. The main routine does some 3644 * policy checking, and creates the name of the coredump; 3645 * then it passes on a vnode and a size limit to the process-specific 3646 * coredump routine if there is one; if there _is not_ one, it returns 3647 * ENOSYS; otherwise it returns the error from the process-specific routine. 3648 */ 3649 3650 static int 3651 coredump(struct thread *td) 3652 { 3653 struct proc *p = td->td_proc; 3654 struct ucred *cred = td->td_ucred; 3655 struct vnode *vp; 3656 struct flock lf; 3657 struct vattr vattr; 3658 size_t fullpathsize; 3659 int error, error1, locked; 3660 char *name; /* name of corefile */ 3661 void *rl_cookie; 3662 off_t limit; 3663 char *fullpath, *freepath = NULL; 3664 struct sbuf *sb; 3665 3666 PROC_LOCK_ASSERT(p, MA_OWNED); 3667 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3668 _STOPEVENT(p, S_CORE, 0); 3669 3670 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3671 (p->p_flag2 & P2_NOTRACE) != 0) { 3672 PROC_UNLOCK(p); 3673 return (EFAULT); 3674 } 3675 3676 /* 3677 * Note that the bulk of limit checking is done after 3678 * the corefile is created. The exception is if the limit 3679 * for corefiles is 0, in which case we don't bother 3680 * creating the corefile at all. This layout means that 3681 * a corefile is truncated instead of not being created, 3682 * if it is larger than the limit. 3683 */ 3684 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3685 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3686 PROC_UNLOCK(p); 3687 return (EFBIG); 3688 } 3689 PROC_UNLOCK(p); 3690 3691 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3692 compress_user_cores, p->p_sig, &vp, &name); 3693 if (error != 0) 3694 return (error); 3695 3696 /* 3697 * Don't dump to non-regular files or files with links. 3698 * Do not dump into system files. Effective user must own the corefile. 3699 */ 3700 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3701 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3702 vattr.va_uid != cred->cr_uid) { 3703 VOP_UNLOCK(vp); 3704 error = EFAULT; 3705 goto out; 3706 } 3707 3708 VOP_UNLOCK(vp); 3709 3710 /* Postpone other writers, including core dumps of other processes. */ 3711 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3712 3713 lf.l_whence = SEEK_SET; 3714 lf.l_start = 0; 3715 lf.l_len = 0; 3716 lf.l_type = F_WRLCK; 3717 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3718 3719 VATTR_NULL(&vattr); 3720 vattr.va_size = 0; 3721 if (set_core_nodump_flag) 3722 vattr.va_flags = UF_NODUMP; 3723 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3724 VOP_SETATTR(vp, &vattr, cred); 3725 VOP_UNLOCK(vp); 3726 PROC_LOCK(p); 3727 p->p_acflag |= ACORE; 3728 PROC_UNLOCK(p); 3729 3730 if (p->p_sysent->sv_coredump != NULL) { 3731 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3732 } else { 3733 error = ENOSYS; 3734 } 3735 3736 if (locked) { 3737 lf.l_type = F_UNLCK; 3738 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3739 } 3740 vn_rangelock_unlock(vp, rl_cookie); 3741 3742 /* 3743 * Notify the userland helper that a process triggered a core dump. 3744 * This allows the helper to run an automated debugging session. 3745 */ 3746 if (error != 0 || coredump_devctl == 0) 3747 goto out; 3748 sb = sbuf_new_auto(); 3749 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3750 goto out2; 3751 sbuf_printf(sb, "comm=\""); 3752 devctl_safe_quote_sb(sb, fullpath); 3753 free(freepath, M_TEMP); 3754 sbuf_printf(sb, "\" core=\""); 3755 3756 /* 3757 * We can't lookup core file vp directly. When we're replacing a core, and 3758 * other random times, we flush the name cache, so it will fail. Instead, 3759 * if the path of the core is relative, add the current dir in front if it. 3760 */ 3761 if (name[0] != '/') { 3762 fullpathsize = MAXPATHLEN; 3763 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3764 if (vn_getcwd(td, freepath, &fullpath, &fullpathsize) != 0) { 3765 free(freepath, M_TEMP); 3766 goto out2; 3767 } 3768 devctl_safe_quote_sb(sb, fullpath); 3769 free(freepath, M_TEMP); 3770 sbuf_putc(sb, '/'); 3771 } 3772 devctl_safe_quote_sb(sb, name); 3773 sbuf_printf(sb, "\""); 3774 if (sbuf_finish(sb) == 0) 3775 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3776 out2: 3777 sbuf_delete(sb); 3778 out: 3779 error1 = vn_close(vp, FWRITE, cred, td); 3780 if (error == 0) 3781 error = error1; 3782 #ifdef AUDIT 3783 audit_proc_coredump(td, name, error); 3784 #endif 3785 free(name, M_TEMP); 3786 return (error); 3787 } 3788 3789 /* 3790 * Nonexistent system call-- signal process (may want to handle it). Flag 3791 * error in case process won't see signal immediately (blocked or ignored). 3792 */ 3793 #ifndef _SYS_SYSPROTO_H_ 3794 struct nosys_args { 3795 int dummy; 3796 }; 3797 #endif 3798 /* ARGSUSED */ 3799 int 3800 nosys(struct thread *td, struct nosys_args *args) 3801 { 3802 struct proc *p; 3803 3804 p = td->td_proc; 3805 3806 PROC_LOCK(p); 3807 tdsignal(td, SIGSYS); 3808 PROC_UNLOCK(p); 3809 if (kern_lognosys == 1 || kern_lognosys == 3) { 3810 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3811 td->td_sa.code); 3812 } 3813 if (kern_lognosys == 2 || kern_lognosys == 3) { 3814 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3815 td->td_sa.code); 3816 } 3817 return (ENOSYS); 3818 } 3819 3820 /* 3821 * Send a SIGIO or SIGURG signal to a process or process group using stored 3822 * credentials rather than those of the current process. 3823 */ 3824 void 3825 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3826 { 3827 ksiginfo_t ksi; 3828 struct sigio *sigio; 3829 3830 ksiginfo_init(&ksi); 3831 ksi.ksi_signo = sig; 3832 ksi.ksi_code = SI_KERNEL; 3833 3834 SIGIO_LOCK(); 3835 sigio = *sigiop; 3836 if (sigio == NULL) { 3837 SIGIO_UNLOCK(); 3838 return; 3839 } 3840 if (sigio->sio_pgid > 0) { 3841 PROC_LOCK(sigio->sio_proc); 3842 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3843 kern_psignal(sigio->sio_proc, sig); 3844 PROC_UNLOCK(sigio->sio_proc); 3845 } else if (sigio->sio_pgid < 0) { 3846 struct proc *p; 3847 3848 PGRP_LOCK(sigio->sio_pgrp); 3849 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3850 PROC_LOCK(p); 3851 if (p->p_state == PRS_NORMAL && 3852 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3853 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3854 kern_psignal(p, sig); 3855 PROC_UNLOCK(p); 3856 } 3857 PGRP_UNLOCK(sigio->sio_pgrp); 3858 } 3859 SIGIO_UNLOCK(); 3860 } 3861 3862 static int 3863 filt_sigattach(struct knote *kn) 3864 { 3865 struct proc *p = curproc; 3866 3867 kn->kn_ptr.p_proc = p; 3868 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3869 3870 knlist_add(p->p_klist, kn, 0); 3871 3872 return (0); 3873 } 3874 3875 static void 3876 filt_sigdetach(struct knote *kn) 3877 { 3878 struct proc *p = kn->kn_ptr.p_proc; 3879 3880 knlist_remove(p->p_klist, kn, 0); 3881 } 3882 3883 /* 3884 * signal knotes are shared with proc knotes, so we apply a mask to 3885 * the hint in order to differentiate them from process hints. This 3886 * could be avoided by using a signal-specific knote list, but probably 3887 * isn't worth the trouble. 3888 */ 3889 static int 3890 filt_signal(struct knote *kn, long hint) 3891 { 3892 3893 if (hint & NOTE_SIGNAL) { 3894 hint &= ~NOTE_SIGNAL; 3895 3896 if (kn->kn_id == hint) 3897 kn->kn_data++; 3898 } 3899 return (kn->kn_data != 0); 3900 } 3901 3902 struct sigacts * 3903 sigacts_alloc(void) 3904 { 3905 struct sigacts *ps; 3906 3907 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3908 refcount_init(&ps->ps_refcnt, 1); 3909 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3910 return (ps); 3911 } 3912 3913 void 3914 sigacts_free(struct sigacts *ps) 3915 { 3916 3917 if (refcount_release(&ps->ps_refcnt) == 0) 3918 return; 3919 mtx_destroy(&ps->ps_mtx); 3920 free(ps, M_SUBPROC); 3921 } 3922 3923 struct sigacts * 3924 sigacts_hold(struct sigacts *ps) 3925 { 3926 3927 refcount_acquire(&ps->ps_refcnt); 3928 return (ps); 3929 } 3930 3931 void 3932 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3933 { 3934 3935 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3936 mtx_lock(&src->ps_mtx); 3937 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3938 mtx_unlock(&src->ps_mtx); 3939 } 3940 3941 int 3942 sigacts_shared(struct sigacts *ps) 3943 { 3944 3945 return (ps->ps_refcnt > 1); 3946 } 3947 3948 void 3949 sig_drop_caught(struct proc *p) 3950 { 3951 int sig; 3952 struct sigacts *ps; 3953 3954 ps = p->p_sigacts; 3955 PROC_LOCK_ASSERT(p, MA_OWNED); 3956 mtx_assert(&ps->ps_mtx, MA_OWNED); 3957 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3958 sig = sig_ffs(&ps->ps_sigcatch); 3959 sigdflt(ps, sig); 3960 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3961 sigqueue_delete_proc(p, sig); 3962 } 3963 } 3964 3965 static void 3966 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 3967 { 3968 ksiginfo_t ksi; 3969 3970 /* 3971 * Prevent further fetches and SIGSEGVs, allowing thread to 3972 * issue syscalls despite corruption. 3973 */ 3974 sigfastblock_clear(td); 3975 3976 if (!sendsig) 3977 return; 3978 ksiginfo_init_trap(&ksi); 3979 ksi.ksi_signo = SIGSEGV; 3980 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 3981 ksi.ksi_addr = td->td_sigblock_ptr; 3982 trapsignal(td, &ksi); 3983 } 3984 3985 static bool 3986 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 3987 { 3988 uint32_t res; 3989 3990 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 3991 return (true); 3992 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 3993 sigfastblock_failed(td, sendsig, false); 3994 return (false); 3995 } 3996 *valp = res; 3997 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 3998 return (true); 3999 } 4000 4001 int 4002 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4003 { 4004 struct proc *p; 4005 int error, res; 4006 uint32_t oldval; 4007 4008 error = 0; 4009 p = td->td_proc; 4010 switch (uap->cmd) { 4011 case SIGFASTBLOCK_SETPTR: 4012 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4013 error = EBUSY; 4014 break; 4015 } 4016 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4017 error = EINVAL; 4018 break; 4019 } 4020 td->td_pflags |= TDP_SIGFASTBLOCK; 4021 td->td_sigblock_ptr = uap->ptr; 4022 break; 4023 4024 case SIGFASTBLOCK_UNBLOCK: 4025 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4026 error = EINVAL; 4027 break; 4028 } 4029 4030 for (;;) { 4031 res = casueword32(td->td_sigblock_ptr, 4032 SIGFASTBLOCK_PEND, &oldval, 0); 4033 if (res == -1) { 4034 error = EFAULT; 4035 sigfastblock_failed(td, false, true); 4036 break; 4037 } 4038 if (res == 0) 4039 break; 4040 MPASS(res == 1); 4041 if (oldval != SIGFASTBLOCK_PEND) { 4042 error = EBUSY; 4043 break; 4044 } 4045 error = thread_check_susp(td, false); 4046 if (error != 0) 4047 break; 4048 } 4049 if (error != 0) 4050 break; 4051 4052 /* 4053 * td_sigblock_val is cleared there, but not on a 4054 * syscall exit. The end effect is that a single 4055 * interruptible sleep, while user sigblock word is 4056 * set, might return EINTR or ERESTART to usermode 4057 * without delivering signal. All further sleeps, 4058 * until userspace clears the word and does 4059 * sigfastblock(UNBLOCK), observe current word and no 4060 * longer get interrupted. It is slight 4061 * non-conformance, with alternative to have read the 4062 * sigblock word on each syscall entry. 4063 */ 4064 td->td_sigblock_val = 0; 4065 4066 /* 4067 * Rely on normal ast mechanism to deliver pending 4068 * signals to current thread. But notify others about 4069 * fake unblock. 4070 */ 4071 if (error == 0 && p->p_numthreads != 1) { 4072 PROC_LOCK(p); 4073 reschedule_signals(p, td->td_sigmask, 0); 4074 PROC_UNLOCK(p); 4075 } 4076 break; 4077 4078 case SIGFASTBLOCK_UNSETPTR: 4079 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4080 error = EINVAL; 4081 break; 4082 } 4083 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4084 error = EFAULT; 4085 break; 4086 } 4087 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4088 error = EBUSY; 4089 break; 4090 } 4091 sigfastblock_clear(td); 4092 break; 4093 4094 default: 4095 error = EINVAL; 4096 break; 4097 } 4098 return (error); 4099 } 4100 4101 void 4102 sigfastblock_clear(struct thread *td) 4103 { 4104 struct proc *p; 4105 bool resched; 4106 4107 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4108 return; 4109 td->td_sigblock_val = 0; 4110 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4111 SIGPENDING(td); 4112 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4113 if (resched) { 4114 p = td->td_proc; 4115 PROC_LOCK(p); 4116 reschedule_signals(p, td->td_sigmask, 0); 4117 PROC_UNLOCK(p); 4118 } 4119 } 4120 4121 void 4122 sigfastblock_fetch(struct thread *td) 4123 { 4124 uint32_t val; 4125 4126 (void)sigfastblock_fetch_sig(td, true, &val); 4127 } 4128 4129 static void 4130 sigfastblock_setpend1(struct thread *td) 4131 { 4132 int res; 4133 uint32_t oldval; 4134 4135 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4136 return; 4137 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4138 if (res == -1) { 4139 sigfastblock_failed(td, true, false); 4140 return; 4141 } 4142 for (;;) { 4143 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4144 oldval | SIGFASTBLOCK_PEND); 4145 if (res == -1) { 4146 sigfastblock_failed(td, true, true); 4147 return; 4148 } 4149 if (res == 0) { 4150 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4151 td->td_pflags &= ~TDP_SIGFASTPENDING; 4152 break; 4153 } 4154 MPASS(res == 1); 4155 if (thread_check_susp(td, false) != 0) 4156 break; 4157 } 4158 } 4159 4160 void 4161 sigfastblock_setpend(struct thread *td, bool resched) 4162 { 4163 struct proc *p; 4164 4165 sigfastblock_setpend1(td); 4166 if (resched) { 4167 p = td->td_proc; 4168 PROC_LOCK(p); 4169 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4170 PROC_UNLOCK(p); 4171 } 4172 } 4173