1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/ctype.h> 46 #include <sys/systm.h> 47 #include <sys/signalvar.h> 48 #include <sys/vnode.h> 49 #include <sys/acct.h> 50 #include <sys/bus.h> 51 #include <sys/capsicum.h> 52 #include <sys/compressor.h> 53 #include <sys/condvar.h> 54 #include <sys/event.h> 55 #include <sys/fcntl.h> 56 #include <sys/imgact.h> 57 #include <sys/kernel.h> 58 #include <sys/ktr.h> 59 #include <sys/ktrace.h> 60 #include <sys/limits.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mutex.h> 64 #include <sys/refcount.h> 65 #include <sys/namei.h> 66 #include <sys/proc.h> 67 #include <sys/procdesc.h> 68 #include <sys/ptrace.h> 69 #include <sys/posix4.h> 70 #include <sys/pioctl.h> 71 #include <sys/racct.h> 72 #include <sys/resourcevar.h> 73 #include <sys/sdt.h> 74 #include <sys/sbuf.h> 75 #include <sys/sleepqueue.h> 76 #include <sys/smp.h> 77 #include <sys/stat.h> 78 #include <sys/sx.h> 79 #include <sys/syscallsubr.h> 80 #include <sys/sysctl.h> 81 #include <sys/sysent.h> 82 #include <sys/syslog.h> 83 #include <sys/sysproto.h> 84 #include <sys/timers.h> 85 #include <sys/unistd.h> 86 #include <sys/wait.h> 87 #include <vm/vm.h> 88 #include <vm/vm_extern.h> 89 #include <vm/uma.h> 90 91 #include <sys/jail.h> 92 93 #include <machine/cpu.h> 94 95 #include <security/audit/audit.h> 96 97 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 98 99 SDT_PROVIDER_DECLARE(proc); 100 SDT_PROBE_DEFINE3(proc, , , signal__send, 101 "struct thread *", "struct proc *", "int"); 102 SDT_PROBE_DEFINE2(proc, , , signal__clear, 103 "int", "ksiginfo_t *"); 104 SDT_PROBE_DEFINE3(proc, , , signal__discard, 105 "struct thread *", "struct proc *", "int"); 106 107 static int coredump(struct thread *); 108 static int killpg1(struct thread *td, int sig, int pgid, int all, 109 ksiginfo_t *ksi); 110 static int issignal(struct thread *td); 111 static int sigprop(int sig); 112 static void tdsigwakeup(struct thread *, int, sig_t, int); 113 static int sig_suspend_threads(struct thread *, struct proc *, int); 114 static int filt_sigattach(struct knote *kn); 115 static void filt_sigdetach(struct knote *kn); 116 static int filt_signal(struct knote *kn, long hint); 117 static struct thread *sigtd(struct proc *p, int sig, bool fast_sigblock); 118 static void sigqueue_start(void); 119 120 static uma_zone_t ksiginfo_zone = NULL; 121 struct filterops sig_filtops = { 122 .f_isfd = 0, 123 .f_attach = filt_sigattach, 124 .f_detach = filt_sigdetach, 125 .f_event = filt_signal, 126 }; 127 128 static int kern_logsigexit = 1; 129 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 130 &kern_logsigexit, 0, 131 "Log processes quitting on abnormal signals to syslog(3)"); 132 133 static int kern_forcesigexit = 1; 134 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 135 &kern_forcesigexit, 0, "Force trap signal to be handled"); 136 137 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 138 "POSIX real time signal"); 139 140 static int max_pending_per_proc = 128; 141 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 142 &max_pending_per_proc, 0, "Max pending signals per proc"); 143 144 static int preallocate_siginfo = 1024; 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 146 &preallocate_siginfo, 0, "Preallocated signal memory size"); 147 148 static int signal_overflow = 0; 149 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 150 &signal_overflow, 0, "Number of signals overflew"); 151 152 static int signal_alloc_fail = 0; 153 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 154 &signal_alloc_fail, 0, "signals failed to be allocated"); 155 156 static int kern_lognosys = 0; 157 SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 158 "Log invalid syscalls"); 159 160 __read_frequently bool sigfastblock_fetch_always = false; 161 SYSCTL_BOOL(_kern, OID_AUTO, sigfastblock_fetch_always, CTLFLAG_RWTUN, 162 &sigfastblock_fetch_always, 0, 163 "Fetch sigfastblock word on each syscall entry for proper " 164 "blocking semantic"); 165 166 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 167 168 /* 169 * Policy -- Can ucred cr1 send SIGIO to process cr2? 170 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 171 * in the right situations. 172 */ 173 #define CANSIGIO(cr1, cr2) \ 174 ((cr1)->cr_uid == 0 || \ 175 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 176 (cr1)->cr_uid == (cr2)->cr_ruid || \ 177 (cr1)->cr_ruid == (cr2)->cr_uid || \ 178 (cr1)->cr_uid == (cr2)->cr_uid) 179 180 static int sugid_coredump; 181 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 182 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 183 184 static int capmode_coredump; 185 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 186 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 187 188 static int do_coredump = 1; 189 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 190 &do_coredump, 0, "Enable/Disable coredumps"); 191 192 static int set_core_nodump_flag = 0; 193 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 194 0, "Enable setting the NODUMP flag on coredump files"); 195 196 static int coredump_devctl = 0; 197 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 198 0, "Generate a devctl notification when processes coredump"); 199 200 /* 201 * Signal properties and actions. 202 * The array below categorizes the signals and their default actions 203 * according to the following properties: 204 */ 205 #define SIGPROP_KILL 0x01 /* terminates process by default */ 206 #define SIGPROP_CORE 0x02 /* ditto and coredumps */ 207 #define SIGPROP_STOP 0x04 /* suspend process */ 208 #define SIGPROP_TTYSTOP 0x08 /* ditto, from tty */ 209 #define SIGPROP_IGNORE 0x10 /* ignore by default */ 210 #define SIGPROP_CONT 0x20 /* continue if suspended */ 211 #define SIGPROP_CANTMASK 0x40 /* non-maskable, catchable */ 212 213 static int sigproptbl[NSIG] = { 214 [SIGHUP] = SIGPROP_KILL, 215 [SIGINT] = SIGPROP_KILL, 216 [SIGQUIT] = SIGPROP_KILL | SIGPROP_CORE, 217 [SIGILL] = SIGPROP_KILL | SIGPROP_CORE, 218 [SIGTRAP] = SIGPROP_KILL | SIGPROP_CORE, 219 [SIGABRT] = SIGPROP_KILL | SIGPROP_CORE, 220 [SIGEMT] = SIGPROP_KILL | SIGPROP_CORE, 221 [SIGFPE] = SIGPROP_KILL | SIGPROP_CORE, 222 [SIGKILL] = SIGPROP_KILL, 223 [SIGBUS] = SIGPROP_KILL | SIGPROP_CORE, 224 [SIGSEGV] = SIGPROP_KILL | SIGPROP_CORE, 225 [SIGSYS] = SIGPROP_KILL | SIGPROP_CORE, 226 [SIGPIPE] = SIGPROP_KILL, 227 [SIGALRM] = SIGPROP_KILL, 228 [SIGTERM] = SIGPROP_KILL, 229 [SIGURG] = SIGPROP_IGNORE, 230 [SIGSTOP] = SIGPROP_STOP, 231 [SIGTSTP] = SIGPROP_STOP | SIGPROP_TTYSTOP, 232 [SIGCONT] = SIGPROP_IGNORE | SIGPROP_CONT, 233 [SIGCHLD] = SIGPROP_IGNORE, 234 [SIGTTIN] = SIGPROP_STOP | SIGPROP_TTYSTOP, 235 [SIGTTOU] = SIGPROP_STOP | SIGPROP_TTYSTOP, 236 [SIGIO] = SIGPROP_IGNORE, 237 [SIGXCPU] = SIGPROP_KILL, 238 [SIGXFSZ] = SIGPROP_KILL, 239 [SIGVTALRM] = SIGPROP_KILL, 240 [SIGPROF] = SIGPROP_KILL, 241 [SIGWINCH] = SIGPROP_IGNORE, 242 [SIGINFO] = SIGPROP_IGNORE, 243 [SIGUSR1] = SIGPROP_KILL, 244 [SIGUSR2] = SIGPROP_KILL, 245 }; 246 247 sigset_t fastblock_mask; 248 249 static void 250 sigqueue_start(void) 251 { 252 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 253 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 254 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 255 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 256 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 257 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 258 SIGFILLSET(fastblock_mask); 259 SIG_CANTMASK(fastblock_mask); 260 } 261 262 ksiginfo_t * 263 ksiginfo_alloc(int wait) 264 { 265 int flags; 266 267 flags = M_ZERO; 268 if (! wait) 269 flags |= M_NOWAIT; 270 if (ksiginfo_zone != NULL) 271 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 272 return (NULL); 273 } 274 275 void 276 ksiginfo_free(ksiginfo_t *ksi) 277 { 278 uma_zfree(ksiginfo_zone, ksi); 279 } 280 281 static __inline int 282 ksiginfo_tryfree(ksiginfo_t *ksi) 283 { 284 if (!(ksi->ksi_flags & KSI_EXT)) { 285 uma_zfree(ksiginfo_zone, ksi); 286 return (1); 287 } 288 return (0); 289 } 290 291 void 292 sigqueue_init(sigqueue_t *list, struct proc *p) 293 { 294 SIGEMPTYSET(list->sq_signals); 295 SIGEMPTYSET(list->sq_kill); 296 SIGEMPTYSET(list->sq_ptrace); 297 TAILQ_INIT(&list->sq_list); 298 list->sq_proc = p; 299 list->sq_flags = SQ_INIT; 300 } 301 302 /* 303 * Get a signal's ksiginfo. 304 * Return: 305 * 0 - signal not found 306 * others - signal number 307 */ 308 static int 309 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 310 { 311 struct proc *p = sq->sq_proc; 312 struct ksiginfo *ksi, *next; 313 int count = 0; 314 315 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 316 317 if (!SIGISMEMBER(sq->sq_signals, signo)) 318 return (0); 319 320 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 321 count++; 322 SIGDELSET(sq->sq_ptrace, signo); 323 si->ksi_flags |= KSI_PTRACE; 324 } 325 if (SIGISMEMBER(sq->sq_kill, signo)) { 326 count++; 327 if (count == 1) 328 SIGDELSET(sq->sq_kill, signo); 329 } 330 331 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 332 if (ksi->ksi_signo == signo) { 333 if (count == 0) { 334 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 335 ksi->ksi_sigq = NULL; 336 ksiginfo_copy(ksi, si); 337 if (ksiginfo_tryfree(ksi) && p != NULL) 338 p->p_pendingcnt--; 339 } 340 if (++count > 1) 341 break; 342 } 343 } 344 345 if (count <= 1) 346 SIGDELSET(sq->sq_signals, signo); 347 si->ksi_signo = signo; 348 return (signo); 349 } 350 351 void 352 sigqueue_take(ksiginfo_t *ksi) 353 { 354 struct ksiginfo *kp; 355 struct proc *p; 356 sigqueue_t *sq; 357 358 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 359 return; 360 361 p = sq->sq_proc; 362 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 363 ksi->ksi_sigq = NULL; 364 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 365 p->p_pendingcnt--; 366 367 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 368 kp = TAILQ_NEXT(kp, ksi_link)) { 369 if (kp->ksi_signo == ksi->ksi_signo) 370 break; 371 } 372 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 373 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 374 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 375 } 376 377 static int 378 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 379 { 380 struct proc *p = sq->sq_proc; 381 struct ksiginfo *ksi; 382 int ret = 0; 383 384 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 385 386 /* 387 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 388 * for these signals. 389 */ 390 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 391 SIGADDSET(sq->sq_kill, signo); 392 goto out_set_bit; 393 } 394 395 /* directly insert the ksi, don't copy it */ 396 if (si->ksi_flags & KSI_INS) { 397 if (si->ksi_flags & KSI_HEAD) 398 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 399 else 400 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 401 si->ksi_sigq = sq; 402 goto out_set_bit; 403 } 404 405 if (__predict_false(ksiginfo_zone == NULL)) { 406 SIGADDSET(sq->sq_kill, signo); 407 goto out_set_bit; 408 } 409 410 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 411 signal_overflow++; 412 ret = EAGAIN; 413 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 414 signal_alloc_fail++; 415 ret = EAGAIN; 416 } else { 417 if (p != NULL) 418 p->p_pendingcnt++; 419 ksiginfo_copy(si, ksi); 420 ksi->ksi_signo = signo; 421 if (si->ksi_flags & KSI_HEAD) 422 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 423 else 424 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 425 ksi->ksi_sigq = sq; 426 } 427 428 if (ret != 0) { 429 if ((si->ksi_flags & KSI_PTRACE) != 0) { 430 SIGADDSET(sq->sq_ptrace, signo); 431 ret = 0; 432 goto out_set_bit; 433 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 434 (si->ksi_flags & KSI_SIGQ) == 0) { 435 SIGADDSET(sq->sq_kill, signo); 436 ret = 0; 437 goto out_set_bit; 438 } 439 return (ret); 440 } 441 442 out_set_bit: 443 SIGADDSET(sq->sq_signals, signo); 444 return (ret); 445 } 446 447 void 448 sigqueue_flush(sigqueue_t *sq) 449 { 450 struct proc *p = sq->sq_proc; 451 ksiginfo_t *ksi; 452 453 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 454 455 if (p != NULL) 456 PROC_LOCK_ASSERT(p, MA_OWNED); 457 458 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 459 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 460 ksi->ksi_sigq = NULL; 461 if (ksiginfo_tryfree(ksi) && p != NULL) 462 p->p_pendingcnt--; 463 } 464 465 SIGEMPTYSET(sq->sq_signals); 466 SIGEMPTYSET(sq->sq_kill); 467 SIGEMPTYSET(sq->sq_ptrace); 468 } 469 470 static void 471 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 472 { 473 sigset_t tmp; 474 struct proc *p1, *p2; 475 ksiginfo_t *ksi, *next; 476 477 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 478 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 479 p1 = src->sq_proc; 480 p2 = dst->sq_proc; 481 /* Move siginfo to target list */ 482 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 483 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 484 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 485 if (p1 != NULL) 486 p1->p_pendingcnt--; 487 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 488 ksi->ksi_sigq = dst; 489 if (p2 != NULL) 490 p2->p_pendingcnt++; 491 } 492 } 493 494 /* Move pending bits to target list */ 495 tmp = src->sq_kill; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_kill, tmp); 498 SIGSETNAND(src->sq_kill, tmp); 499 500 tmp = src->sq_ptrace; 501 SIGSETAND(tmp, *set); 502 SIGSETOR(dst->sq_ptrace, tmp); 503 SIGSETNAND(src->sq_ptrace, tmp); 504 505 tmp = src->sq_signals; 506 SIGSETAND(tmp, *set); 507 SIGSETOR(dst->sq_signals, tmp); 508 SIGSETNAND(src->sq_signals, tmp); 509 } 510 511 #if 0 512 static void 513 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 514 { 515 sigset_t set; 516 517 SIGEMPTYSET(set); 518 SIGADDSET(set, signo); 519 sigqueue_move_set(src, dst, &set); 520 } 521 #endif 522 523 static void 524 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 525 { 526 struct proc *p = sq->sq_proc; 527 ksiginfo_t *ksi, *next; 528 529 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 530 531 /* Remove siginfo queue */ 532 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 533 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 534 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 535 ksi->ksi_sigq = NULL; 536 if (ksiginfo_tryfree(ksi) && p != NULL) 537 p->p_pendingcnt--; 538 } 539 } 540 SIGSETNAND(sq->sq_kill, *set); 541 SIGSETNAND(sq->sq_ptrace, *set); 542 SIGSETNAND(sq->sq_signals, *set); 543 } 544 545 void 546 sigqueue_delete(sigqueue_t *sq, int signo) 547 { 548 sigset_t set; 549 550 SIGEMPTYSET(set); 551 SIGADDSET(set, signo); 552 sigqueue_delete_set(sq, &set); 553 } 554 555 /* Remove a set of signals for a process */ 556 static void 557 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 558 { 559 sigqueue_t worklist; 560 struct thread *td0; 561 562 PROC_LOCK_ASSERT(p, MA_OWNED); 563 564 sigqueue_init(&worklist, NULL); 565 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 566 567 FOREACH_THREAD_IN_PROC(p, td0) 568 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 569 570 sigqueue_flush(&worklist); 571 } 572 573 void 574 sigqueue_delete_proc(struct proc *p, int signo) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, signo); 580 sigqueue_delete_set_proc(p, &set); 581 } 582 583 static void 584 sigqueue_delete_stopmask_proc(struct proc *p) 585 { 586 sigset_t set; 587 588 SIGEMPTYSET(set); 589 SIGADDSET(set, SIGSTOP); 590 SIGADDSET(set, SIGTSTP); 591 SIGADDSET(set, SIGTTIN); 592 SIGADDSET(set, SIGTTOU); 593 sigqueue_delete_set_proc(p, &set); 594 } 595 596 /* 597 * Determine signal that should be delivered to thread td, the current 598 * thread, 0 if none. If there is a pending stop signal with default 599 * action, the process stops in issignal(). 600 */ 601 int 602 cursig(struct thread *td) 603 { 604 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 605 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 606 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 607 return (SIGPENDING(td) ? issignal(td) : 0); 608 } 609 610 /* 611 * Arrange for ast() to handle unmasked pending signals on return to user 612 * mode. This must be called whenever a signal is added to td_sigqueue or 613 * unmasked in td_sigmask. 614 */ 615 void 616 signotify(struct thread *td) 617 { 618 619 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 620 621 if (SIGPENDING(td)) { 622 thread_lock(td); 623 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 624 thread_unlock(td); 625 } 626 } 627 628 /* 629 * Returns 1 (true) if altstack is configured for the thread, and the 630 * passed stack bottom address falls into the altstack range. Handles 631 * the 43 compat special case where the alt stack size is zero. 632 */ 633 int 634 sigonstack(size_t sp) 635 { 636 struct thread *td; 637 638 td = curthread; 639 if ((td->td_pflags & TDP_ALTSTACK) == 0) 640 return (0); 641 #if defined(COMPAT_43) 642 if (SV_PROC_FLAG(td->td_proc, SV_AOUT) && td->td_sigstk.ss_size == 0) 643 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 644 #endif 645 return (sp >= (size_t)td->td_sigstk.ss_sp && 646 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 647 } 648 649 static __inline int 650 sigprop(int sig) 651 { 652 653 if (sig > 0 && sig < nitems(sigproptbl)) 654 return (sigproptbl[sig]); 655 return (0); 656 } 657 658 int 659 sig_ffs(sigset_t *set) 660 { 661 int i; 662 663 for (i = 0; i < _SIG_WORDS; i++) 664 if (set->__bits[i]) 665 return (ffs(set->__bits[i]) + (i * 32)); 666 return (0); 667 } 668 669 static bool 670 sigact_flag_test(const struct sigaction *act, int flag) 671 { 672 673 /* 674 * SA_SIGINFO is reset when signal disposition is set to 675 * ignore or default. Other flags are kept according to user 676 * settings. 677 */ 678 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 679 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 680 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 681 } 682 683 /* 684 * kern_sigaction 685 * sigaction 686 * freebsd4_sigaction 687 * osigaction 688 */ 689 int 690 kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 691 struct sigaction *oact, int flags) 692 { 693 struct sigacts *ps; 694 struct proc *p = td->td_proc; 695 696 if (!_SIG_VALID(sig)) 697 return (EINVAL); 698 if (act != NULL && act->sa_handler != SIG_DFL && 699 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 700 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 701 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 702 return (EINVAL); 703 704 PROC_LOCK(p); 705 ps = p->p_sigacts; 706 mtx_lock(&ps->ps_mtx); 707 if (oact) { 708 memset(oact, 0, sizeof(*oact)); 709 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 710 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 711 oact->sa_flags |= SA_ONSTACK; 712 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 713 oact->sa_flags |= SA_RESTART; 714 if (SIGISMEMBER(ps->ps_sigreset, sig)) 715 oact->sa_flags |= SA_RESETHAND; 716 if (SIGISMEMBER(ps->ps_signodefer, sig)) 717 oact->sa_flags |= SA_NODEFER; 718 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 719 oact->sa_flags |= SA_SIGINFO; 720 oact->sa_sigaction = 721 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 722 } else 723 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 724 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 725 oact->sa_flags |= SA_NOCLDSTOP; 726 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 727 oact->sa_flags |= SA_NOCLDWAIT; 728 } 729 if (act) { 730 if ((sig == SIGKILL || sig == SIGSTOP) && 731 act->sa_handler != SIG_DFL) { 732 mtx_unlock(&ps->ps_mtx); 733 PROC_UNLOCK(p); 734 return (EINVAL); 735 } 736 737 /* 738 * Change setting atomically. 739 */ 740 741 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 742 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 743 if (sigact_flag_test(act, SA_SIGINFO)) { 744 ps->ps_sigact[_SIG_IDX(sig)] = 745 (__sighandler_t *)act->sa_sigaction; 746 SIGADDSET(ps->ps_siginfo, sig); 747 } else { 748 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 749 SIGDELSET(ps->ps_siginfo, sig); 750 } 751 if (!sigact_flag_test(act, SA_RESTART)) 752 SIGADDSET(ps->ps_sigintr, sig); 753 else 754 SIGDELSET(ps->ps_sigintr, sig); 755 if (sigact_flag_test(act, SA_ONSTACK)) 756 SIGADDSET(ps->ps_sigonstack, sig); 757 else 758 SIGDELSET(ps->ps_sigonstack, sig); 759 if (sigact_flag_test(act, SA_RESETHAND)) 760 SIGADDSET(ps->ps_sigreset, sig); 761 else 762 SIGDELSET(ps->ps_sigreset, sig); 763 if (sigact_flag_test(act, SA_NODEFER)) 764 SIGADDSET(ps->ps_signodefer, sig); 765 else 766 SIGDELSET(ps->ps_signodefer, sig); 767 if (sig == SIGCHLD) { 768 if (act->sa_flags & SA_NOCLDSTOP) 769 ps->ps_flag |= PS_NOCLDSTOP; 770 else 771 ps->ps_flag &= ~PS_NOCLDSTOP; 772 if (act->sa_flags & SA_NOCLDWAIT) { 773 /* 774 * Paranoia: since SA_NOCLDWAIT is implemented 775 * by reparenting the dying child to PID 1 (and 776 * trust it to reap the zombie), PID 1 itself 777 * is forbidden to set SA_NOCLDWAIT. 778 */ 779 if (p->p_pid == 1) 780 ps->ps_flag &= ~PS_NOCLDWAIT; 781 else 782 ps->ps_flag |= PS_NOCLDWAIT; 783 } else 784 ps->ps_flag &= ~PS_NOCLDWAIT; 785 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 786 ps->ps_flag |= PS_CLDSIGIGN; 787 else 788 ps->ps_flag &= ~PS_CLDSIGIGN; 789 } 790 /* 791 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 792 * and for signals set to SIG_DFL where the default is to 793 * ignore. However, don't put SIGCONT in ps_sigignore, as we 794 * have to restart the process. 795 */ 796 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 797 (sigprop(sig) & SIGPROP_IGNORE && 798 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 799 /* never to be seen again */ 800 sigqueue_delete_proc(p, sig); 801 if (sig != SIGCONT) 802 /* easier in psignal */ 803 SIGADDSET(ps->ps_sigignore, sig); 804 SIGDELSET(ps->ps_sigcatch, sig); 805 } else { 806 SIGDELSET(ps->ps_sigignore, sig); 807 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 808 SIGDELSET(ps->ps_sigcatch, sig); 809 else 810 SIGADDSET(ps->ps_sigcatch, sig); 811 } 812 #ifdef COMPAT_FREEBSD4 813 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 814 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 815 (flags & KSA_FREEBSD4) == 0) 816 SIGDELSET(ps->ps_freebsd4, sig); 817 else 818 SIGADDSET(ps->ps_freebsd4, sig); 819 #endif 820 #ifdef COMPAT_43 821 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 822 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 823 (flags & KSA_OSIGSET) == 0) 824 SIGDELSET(ps->ps_osigset, sig); 825 else 826 SIGADDSET(ps->ps_osigset, sig); 827 #endif 828 } 829 mtx_unlock(&ps->ps_mtx); 830 PROC_UNLOCK(p); 831 return (0); 832 } 833 834 #ifndef _SYS_SYSPROTO_H_ 835 struct sigaction_args { 836 int sig; 837 struct sigaction *act; 838 struct sigaction *oact; 839 }; 840 #endif 841 int 842 sys_sigaction(struct thread *td, struct sigaction_args *uap) 843 { 844 struct sigaction act, oact; 845 struct sigaction *actp, *oactp; 846 int error; 847 848 actp = (uap->act != NULL) ? &act : NULL; 849 oactp = (uap->oact != NULL) ? &oact : NULL; 850 if (actp) { 851 error = copyin(uap->act, actp, sizeof(act)); 852 if (error) 853 return (error); 854 } 855 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 856 if (oactp && !error) 857 error = copyout(oactp, uap->oact, sizeof(oact)); 858 return (error); 859 } 860 861 #ifdef COMPAT_FREEBSD4 862 #ifndef _SYS_SYSPROTO_H_ 863 struct freebsd4_sigaction_args { 864 int sig; 865 struct sigaction *act; 866 struct sigaction *oact; 867 }; 868 #endif 869 int 870 freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 871 { 872 struct sigaction act, oact; 873 struct sigaction *actp, *oactp; 874 int error; 875 876 actp = (uap->act != NULL) ? &act : NULL; 877 oactp = (uap->oact != NULL) ? &oact : NULL; 878 if (actp) { 879 error = copyin(uap->act, actp, sizeof(act)); 880 if (error) 881 return (error); 882 } 883 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 884 if (oactp && !error) 885 error = copyout(oactp, uap->oact, sizeof(oact)); 886 return (error); 887 } 888 #endif /* COMAPT_FREEBSD4 */ 889 890 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 891 #ifndef _SYS_SYSPROTO_H_ 892 struct osigaction_args { 893 int signum; 894 struct osigaction *nsa; 895 struct osigaction *osa; 896 }; 897 #endif 898 int 899 osigaction(struct thread *td, struct osigaction_args *uap) 900 { 901 struct osigaction sa; 902 struct sigaction nsa, osa; 903 struct sigaction *nsap, *osap; 904 int error; 905 906 if (uap->signum <= 0 || uap->signum >= ONSIG) 907 return (EINVAL); 908 909 nsap = (uap->nsa != NULL) ? &nsa : NULL; 910 osap = (uap->osa != NULL) ? &osa : NULL; 911 912 if (nsap) { 913 error = copyin(uap->nsa, &sa, sizeof(sa)); 914 if (error) 915 return (error); 916 nsap->sa_handler = sa.sa_handler; 917 nsap->sa_flags = sa.sa_flags; 918 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 919 } 920 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 921 if (osap && !error) { 922 sa.sa_handler = osap->sa_handler; 923 sa.sa_flags = osap->sa_flags; 924 SIG2OSIG(osap->sa_mask, sa.sa_mask); 925 error = copyout(&sa, uap->osa, sizeof(sa)); 926 } 927 return (error); 928 } 929 930 #if !defined(__i386__) 931 /* Avoid replicating the same stub everywhere */ 932 int 933 osigreturn(struct thread *td, struct osigreturn_args *uap) 934 { 935 936 return (nosys(td, (struct nosys_args *)uap)); 937 } 938 #endif 939 #endif /* COMPAT_43 */ 940 941 /* 942 * Initialize signal state for process 0; 943 * set to ignore signals that are ignored by default. 944 */ 945 void 946 siginit(struct proc *p) 947 { 948 int i; 949 struct sigacts *ps; 950 951 PROC_LOCK(p); 952 ps = p->p_sigacts; 953 mtx_lock(&ps->ps_mtx); 954 for (i = 1; i <= NSIG; i++) { 955 if (sigprop(i) & SIGPROP_IGNORE && i != SIGCONT) { 956 SIGADDSET(ps->ps_sigignore, i); 957 } 958 } 959 mtx_unlock(&ps->ps_mtx); 960 PROC_UNLOCK(p); 961 } 962 963 /* 964 * Reset specified signal to the default disposition. 965 */ 966 static void 967 sigdflt(struct sigacts *ps, int sig) 968 { 969 970 mtx_assert(&ps->ps_mtx, MA_OWNED); 971 SIGDELSET(ps->ps_sigcatch, sig); 972 if ((sigprop(sig) & SIGPROP_IGNORE) != 0 && sig != SIGCONT) 973 SIGADDSET(ps->ps_sigignore, sig); 974 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 975 SIGDELSET(ps->ps_siginfo, sig); 976 } 977 978 /* 979 * Reset signals for an exec of the specified process. 980 */ 981 void 982 execsigs(struct proc *p) 983 { 984 sigset_t osigignore; 985 struct sigacts *ps; 986 int sig; 987 struct thread *td; 988 989 /* 990 * Reset caught signals. Held signals remain held 991 * through td_sigmask (unless they were caught, 992 * and are now ignored by default). 993 */ 994 PROC_LOCK_ASSERT(p, MA_OWNED); 995 ps = p->p_sigacts; 996 mtx_lock(&ps->ps_mtx); 997 sig_drop_caught(p); 998 999 /* 1000 * As CloudABI processes cannot modify signal handlers, fully 1001 * reset all signals to their default behavior. Do ignore 1002 * SIGPIPE, as it would otherwise be impossible to recover from 1003 * writes to broken pipes and sockets. 1004 */ 1005 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1006 osigignore = ps->ps_sigignore; 1007 while (SIGNOTEMPTY(osigignore)) { 1008 sig = sig_ffs(&osigignore); 1009 SIGDELSET(osigignore, sig); 1010 if (sig != SIGPIPE) 1011 sigdflt(ps, sig); 1012 } 1013 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1014 } 1015 1016 /* 1017 * Reset stack state to the user stack. 1018 * Clear set of signals caught on the signal stack. 1019 */ 1020 td = curthread; 1021 MPASS(td->td_proc == p); 1022 td->td_sigstk.ss_flags = SS_DISABLE; 1023 td->td_sigstk.ss_size = 0; 1024 td->td_sigstk.ss_sp = 0; 1025 td->td_pflags &= ~TDP_ALTSTACK; 1026 /* 1027 * Reset no zombies if child dies flag as Solaris does. 1028 */ 1029 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1030 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1031 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1032 mtx_unlock(&ps->ps_mtx); 1033 } 1034 1035 /* 1036 * kern_sigprocmask() 1037 * 1038 * Manipulate signal mask. 1039 */ 1040 int 1041 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1042 int flags) 1043 { 1044 sigset_t new_block, oset1; 1045 struct proc *p; 1046 int error; 1047 1048 p = td->td_proc; 1049 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1050 PROC_LOCK_ASSERT(p, MA_OWNED); 1051 else 1052 PROC_LOCK(p); 1053 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1054 ? MA_OWNED : MA_NOTOWNED); 1055 if (oset != NULL) 1056 *oset = td->td_sigmask; 1057 1058 error = 0; 1059 if (set != NULL) { 1060 switch (how) { 1061 case SIG_BLOCK: 1062 SIG_CANTMASK(*set); 1063 oset1 = td->td_sigmask; 1064 SIGSETOR(td->td_sigmask, *set); 1065 new_block = td->td_sigmask; 1066 SIGSETNAND(new_block, oset1); 1067 break; 1068 case SIG_UNBLOCK: 1069 SIGSETNAND(td->td_sigmask, *set); 1070 signotify(td); 1071 goto out; 1072 case SIG_SETMASK: 1073 SIG_CANTMASK(*set); 1074 oset1 = td->td_sigmask; 1075 if (flags & SIGPROCMASK_OLD) 1076 SIGSETLO(td->td_sigmask, *set); 1077 else 1078 td->td_sigmask = *set; 1079 new_block = td->td_sigmask; 1080 SIGSETNAND(new_block, oset1); 1081 signotify(td); 1082 break; 1083 default: 1084 error = EINVAL; 1085 goto out; 1086 } 1087 1088 /* 1089 * The new_block set contains signals that were not previously 1090 * blocked, but are blocked now. 1091 * 1092 * In case we block any signal that was not previously blocked 1093 * for td, and process has the signal pending, try to schedule 1094 * signal delivery to some thread that does not block the 1095 * signal, possibly waking it up. 1096 */ 1097 if (p->p_numthreads != 1) 1098 reschedule_signals(p, new_block, flags); 1099 } 1100 1101 out: 1102 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1103 PROC_UNLOCK(p); 1104 return (error); 1105 } 1106 1107 #ifndef _SYS_SYSPROTO_H_ 1108 struct sigprocmask_args { 1109 int how; 1110 const sigset_t *set; 1111 sigset_t *oset; 1112 }; 1113 #endif 1114 int 1115 sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1116 { 1117 sigset_t set, oset; 1118 sigset_t *setp, *osetp; 1119 int error; 1120 1121 setp = (uap->set != NULL) ? &set : NULL; 1122 osetp = (uap->oset != NULL) ? &oset : NULL; 1123 if (setp) { 1124 error = copyin(uap->set, setp, sizeof(set)); 1125 if (error) 1126 return (error); 1127 } 1128 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1129 if (osetp && !error) { 1130 error = copyout(osetp, uap->oset, sizeof(oset)); 1131 } 1132 return (error); 1133 } 1134 1135 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1136 #ifndef _SYS_SYSPROTO_H_ 1137 struct osigprocmask_args { 1138 int how; 1139 osigset_t mask; 1140 }; 1141 #endif 1142 int 1143 osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1144 { 1145 sigset_t set, oset; 1146 int error; 1147 1148 OSIG2SIG(uap->mask, set); 1149 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1150 SIG2OSIG(oset, td->td_retval[0]); 1151 return (error); 1152 } 1153 #endif /* COMPAT_43 */ 1154 1155 int 1156 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1157 { 1158 ksiginfo_t ksi; 1159 sigset_t set; 1160 int error; 1161 1162 error = copyin(uap->set, &set, sizeof(set)); 1163 if (error) { 1164 td->td_retval[0] = error; 1165 return (0); 1166 } 1167 1168 error = kern_sigtimedwait(td, set, &ksi, NULL); 1169 if (error) { 1170 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1171 error = ERESTART; 1172 if (error == ERESTART) 1173 return (error); 1174 td->td_retval[0] = error; 1175 return (0); 1176 } 1177 1178 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1179 td->td_retval[0] = error; 1180 return (0); 1181 } 1182 1183 int 1184 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1185 { 1186 struct timespec ts; 1187 struct timespec *timeout; 1188 sigset_t set; 1189 ksiginfo_t ksi; 1190 int error; 1191 1192 if (uap->timeout) { 1193 error = copyin(uap->timeout, &ts, sizeof(ts)); 1194 if (error) 1195 return (error); 1196 1197 timeout = &ts; 1198 } else 1199 timeout = NULL; 1200 1201 error = copyin(uap->set, &set, sizeof(set)); 1202 if (error) 1203 return (error); 1204 1205 error = kern_sigtimedwait(td, set, &ksi, timeout); 1206 if (error) 1207 return (error); 1208 1209 if (uap->info) 1210 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1211 1212 if (error == 0) 1213 td->td_retval[0] = ksi.ksi_signo; 1214 return (error); 1215 } 1216 1217 int 1218 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1219 { 1220 ksiginfo_t ksi; 1221 sigset_t set; 1222 int error; 1223 1224 error = copyin(uap->set, &set, sizeof(set)); 1225 if (error) 1226 return (error); 1227 1228 error = kern_sigtimedwait(td, set, &ksi, NULL); 1229 if (error) 1230 return (error); 1231 1232 if (uap->info) 1233 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1234 1235 if (error == 0) 1236 td->td_retval[0] = ksi.ksi_signo; 1237 return (error); 1238 } 1239 1240 static void 1241 proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1242 { 1243 struct thread *thr; 1244 1245 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1246 if (thr == td) 1247 thr->td_si = *si; 1248 else 1249 thr->td_si.si_signo = 0; 1250 } 1251 } 1252 1253 int 1254 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1255 struct timespec *timeout) 1256 { 1257 struct sigacts *ps; 1258 sigset_t saved_mask, new_block; 1259 struct proc *p; 1260 int error, sig, timo, timevalid = 0; 1261 struct timespec rts, ets, ts; 1262 struct timeval tv; 1263 bool traced; 1264 1265 p = td->td_proc; 1266 error = 0; 1267 ets.tv_sec = 0; 1268 ets.tv_nsec = 0; 1269 traced = false; 1270 1271 if (timeout != NULL) { 1272 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1273 timevalid = 1; 1274 getnanouptime(&rts); 1275 timespecadd(&rts, timeout, &ets); 1276 } 1277 } 1278 ksiginfo_init(ksi); 1279 /* Some signals can not be waited for. */ 1280 SIG_CANTMASK(waitset); 1281 ps = p->p_sigacts; 1282 PROC_LOCK(p); 1283 saved_mask = td->td_sigmask; 1284 SIGSETNAND(td->td_sigmask, waitset); 1285 for (;;) { 1286 mtx_lock(&ps->ps_mtx); 1287 sig = cursig(td); 1288 mtx_unlock(&ps->ps_mtx); 1289 KASSERT(sig >= 0, ("sig %d", sig)); 1290 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1291 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1292 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1293 error = 0; 1294 break; 1295 } 1296 } 1297 1298 if (error != 0) 1299 break; 1300 1301 /* 1302 * POSIX says this must be checked after looking for pending 1303 * signals. 1304 */ 1305 if (timeout != NULL) { 1306 if (!timevalid) { 1307 error = EINVAL; 1308 break; 1309 } 1310 getnanouptime(&rts); 1311 if (timespeccmp(&rts, &ets, >=)) { 1312 error = EAGAIN; 1313 break; 1314 } 1315 timespecsub(&ets, &rts, &ts); 1316 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1317 timo = tvtohz(&tv); 1318 } else { 1319 timo = 0; 1320 } 1321 1322 if (traced) { 1323 error = EINTR; 1324 break; 1325 } 1326 1327 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1328 1329 if (timeout != NULL) { 1330 if (error == ERESTART) { 1331 /* Timeout can not be restarted. */ 1332 error = EINTR; 1333 } else if (error == EAGAIN) { 1334 /* We will calculate timeout by ourself. */ 1335 error = 0; 1336 } 1337 } 1338 1339 /* 1340 * If PTRACE_SCE or PTRACE_SCX were set after 1341 * userspace entered the syscall, return spurious 1342 * EINTR after wait was done. Only do this as last 1343 * resort after rechecking for possible queued signals 1344 * and expired timeouts. 1345 */ 1346 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1347 traced = true; 1348 } 1349 1350 new_block = saved_mask; 1351 SIGSETNAND(new_block, td->td_sigmask); 1352 td->td_sigmask = saved_mask; 1353 /* 1354 * Fewer signals can be delivered to us, reschedule signal 1355 * notification. 1356 */ 1357 if (p->p_numthreads != 1) 1358 reschedule_signals(p, new_block, 0); 1359 1360 if (error == 0) { 1361 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1362 1363 if (ksi->ksi_code == SI_TIMER) 1364 itimer_accept(p, ksi->ksi_timerid, ksi); 1365 1366 #ifdef KTRACE 1367 if (KTRPOINT(td, KTR_PSIG)) { 1368 sig_t action; 1369 1370 mtx_lock(&ps->ps_mtx); 1371 action = ps->ps_sigact[_SIG_IDX(sig)]; 1372 mtx_unlock(&ps->ps_mtx); 1373 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1374 } 1375 #endif 1376 if (sig == SIGKILL) { 1377 proc_td_siginfo_capture(td, &ksi->ksi_info); 1378 sigexit(td, sig); 1379 } 1380 } 1381 PROC_UNLOCK(p); 1382 return (error); 1383 } 1384 1385 #ifndef _SYS_SYSPROTO_H_ 1386 struct sigpending_args { 1387 sigset_t *set; 1388 }; 1389 #endif 1390 int 1391 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1392 { 1393 struct proc *p = td->td_proc; 1394 sigset_t pending; 1395 1396 PROC_LOCK(p); 1397 pending = p->p_sigqueue.sq_signals; 1398 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1399 PROC_UNLOCK(p); 1400 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1401 } 1402 1403 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1404 #ifndef _SYS_SYSPROTO_H_ 1405 struct osigpending_args { 1406 int dummy; 1407 }; 1408 #endif 1409 int 1410 osigpending(struct thread *td, struct osigpending_args *uap) 1411 { 1412 struct proc *p = td->td_proc; 1413 sigset_t pending; 1414 1415 PROC_LOCK(p); 1416 pending = p->p_sigqueue.sq_signals; 1417 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1418 PROC_UNLOCK(p); 1419 SIG2OSIG(pending, td->td_retval[0]); 1420 return (0); 1421 } 1422 #endif /* COMPAT_43 */ 1423 1424 #if defined(COMPAT_43) 1425 /* 1426 * Generalized interface signal handler, 4.3-compatible. 1427 */ 1428 #ifndef _SYS_SYSPROTO_H_ 1429 struct osigvec_args { 1430 int signum; 1431 struct sigvec *nsv; 1432 struct sigvec *osv; 1433 }; 1434 #endif 1435 /* ARGSUSED */ 1436 int 1437 osigvec(struct thread *td, struct osigvec_args *uap) 1438 { 1439 struct sigvec vec; 1440 struct sigaction nsa, osa; 1441 struct sigaction *nsap, *osap; 1442 int error; 1443 1444 if (uap->signum <= 0 || uap->signum >= ONSIG) 1445 return (EINVAL); 1446 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1447 osap = (uap->osv != NULL) ? &osa : NULL; 1448 if (nsap) { 1449 error = copyin(uap->nsv, &vec, sizeof(vec)); 1450 if (error) 1451 return (error); 1452 nsap->sa_handler = vec.sv_handler; 1453 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1454 nsap->sa_flags = vec.sv_flags; 1455 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1456 } 1457 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1458 if (osap && !error) { 1459 vec.sv_handler = osap->sa_handler; 1460 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1461 vec.sv_flags = osap->sa_flags; 1462 vec.sv_flags &= ~SA_NOCLDWAIT; 1463 vec.sv_flags ^= SA_RESTART; 1464 error = copyout(&vec, uap->osv, sizeof(vec)); 1465 } 1466 return (error); 1467 } 1468 1469 #ifndef _SYS_SYSPROTO_H_ 1470 struct osigblock_args { 1471 int mask; 1472 }; 1473 #endif 1474 int 1475 osigblock(struct thread *td, struct osigblock_args *uap) 1476 { 1477 sigset_t set, oset; 1478 1479 OSIG2SIG(uap->mask, set); 1480 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1481 SIG2OSIG(oset, td->td_retval[0]); 1482 return (0); 1483 } 1484 1485 #ifndef _SYS_SYSPROTO_H_ 1486 struct osigsetmask_args { 1487 int mask; 1488 }; 1489 #endif 1490 int 1491 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1492 { 1493 sigset_t set, oset; 1494 1495 OSIG2SIG(uap->mask, set); 1496 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1497 SIG2OSIG(oset, td->td_retval[0]); 1498 return (0); 1499 } 1500 #endif /* COMPAT_43 */ 1501 1502 /* 1503 * Suspend calling thread until signal, providing mask to be set in the 1504 * meantime. 1505 */ 1506 #ifndef _SYS_SYSPROTO_H_ 1507 struct sigsuspend_args { 1508 const sigset_t *sigmask; 1509 }; 1510 #endif 1511 /* ARGSUSED */ 1512 int 1513 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1514 { 1515 sigset_t mask; 1516 int error; 1517 1518 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1519 if (error) 1520 return (error); 1521 return (kern_sigsuspend(td, mask)); 1522 } 1523 1524 int 1525 kern_sigsuspend(struct thread *td, sigset_t mask) 1526 { 1527 struct proc *p = td->td_proc; 1528 int has_sig, sig; 1529 1530 /* 1531 * When returning from sigsuspend, we want 1532 * the old mask to be restored after the 1533 * signal handler has finished. Thus, we 1534 * save it here and mark the sigacts structure 1535 * to indicate this. 1536 */ 1537 PROC_LOCK(p); 1538 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1539 SIGPROCMASK_PROC_LOCKED); 1540 td->td_pflags |= TDP_OLDMASK; 1541 1542 /* 1543 * Process signals now. Otherwise, we can get spurious wakeup 1544 * due to signal entered process queue, but delivered to other 1545 * thread. But sigsuspend should return only on signal 1546 * delivery. 1547 */ 1548 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1549 for (has_sig = 0; !has_sig;) { 1550 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1551 0) == 0) 1552 /* void */; 1553 thread_suspend_check(0); 1554 mtx_lock(&p->p_sigacts->ps_mtx); 1555 while ((sig = cursig(td)) != 0) { 1556 KASSERT(sig >= 0, ("sig %d", sig)); 1557 has_sig += postsig(sig); 1558 } 1559 mtx_unlock(&p->p_sigacts->ps_mtx); 1560 1561 /* 1562 * If PTRACE_SCE or PTRACE_SCX were set after 1563 * userspace entered the syscall, return spurious 1564 * EINTR. 1565 */ 1566 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1567 has_sig += 1; 1568 } 1569 PROC_UNLOCK(p); 1570 td->td_errno = EINTR; 1571 td->td_pflags |= TDP_NERRNO; 1572 return (EJUSTRETURN); 1573 } 1574 1575 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1576 /* 1577 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1578 * convention: libc stub passes mask, not pointer, to save a copyin. 1579 */ 1580 #ifndef _SYS_SYSPROTO_H_ 1581 struct osigsuspend_args { 1582 osigset_t mask; 1583 }; 1584 #endif 1585 /* ARGSUSED */ 1586 int 1587 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1588 { 1589 sigset_t mask; 1590 1591 OSIG2SIG(uap->mask, mask); 1592 return (kern_sigsuspend(td, mask)); 1593 } 1594 #endif /* COMPAT_43 */ 1595 1596 #if defined(COMPAT_43) 1597 #ifndef _SYS_SYSPROTO_H_ 1598 struct osigstack_args { 1599 struct sigstack *nss; 1600 struct sigstack *oss; 1601 }; 1602 #endif 1603 /* ARGSUSED */ 1604 int 1605 osigstack(struct thread *td, struct osigstack_args *uap) 1606 { 1607 struct sigstack nss, oss; 1608 int error = 0; 1609 1610 if (uap->nss != NULL) { 1611 error = copyin(uap->nss, &nss, sizeof(nss)); 1612 if (error) 1613 return (error); 1614 } 1615 oss.ss_sp = td->td_sigstk.ss_sp; 1616 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1617 if (uap->nss != NULL) { 1618 td->td_sigstk.ss_sp = nss.ss_sp; 1619 td->td_sigstk.ss_size = 0; 1620 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1621 td->td_pflags |= TDP_ALTSTACK; 1622 } 1623 if (uap->oss != NULL) 1624 error = copyout(&oss, uap->oss, sizeof(oss)); 1625 1626 return (error); 1627 } 1628 #endif /* COMPAT_43 */ 1629 1630 #ifndef _SYS_SYSPROTO_H_ 1631 struct sigaltstack_args { 1632 stack_t *ss; 1633 stack_t *oss; 1634 }; 1635 #endif 1636 /* ARGSUSED */ 1637 int 1638 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1639 { 1640 stack_t ss, oss; 1641 int error; 1642 1643 if (uap->ss != NULL) { 1644 error = copyin(uap->ss, &ss, sizeof(ss)); 1645 if (error) 1646 return (error); 1647 } 1648 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1649 (uap->oss != NULL) ? &oss : NULL); 1650 if (error) 1651 return (error); 1652 if (uap->oss != NULL) 1653 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1654 return (error); 1655 } 1656 1657 int 1658 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1659 { 1660 struct proc *p = td->td_proc; 1661 int oonstack; 1662 1663 oonstack = sigonstack(cpu_getstack(td)); 1664 1665 if (oss != NULL) { 1666 *oss = td->td_sigstk; 1667 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1668 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1669 } 1670 1671 if (ss != NULL) { 1672 if (oonstack) 1673 return (EPERM); 1674 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1675 return (EINVAL); 1676 if (!(ss->ss_flags & SS_DISABLE)) { 1677 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1678 return (ENOMEM); 1679 1680 td->td_sigstk = *ss; 1681 td->td_pflags |= TDP_ALTSTACK; 1682 } else { 1683 td->td_pflags &= ~TDP_ALTSTACK; 1684 } 1685 } 1686 return (0); 1687 } 1688 1689 struct killpg1_ctx { 1690 struct thread *td; 1691 ksiginfo_t *ksi; 1692 int sig; 1693 bool sent; 1694 bool found; 1695 int ret; 1696 }; 1697 1698 static void 1699 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1700 { 1701 int err; 1702 1703 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1704 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1705 return; 1706 PROC_LOCK(p); 1707 err = p_cansignal(arg->td, p, arg->sig); 1708 if (err == 0 && arg->sig != 0) 1709 pksignal(p, arg->sig, arg->ksi); 1710 PROC_UNLOCK(p); 1711 if (err != ESRCH) 1712 arg->found = true; 1713 if (err == 0) 1714 arg->sent = true; 1715 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1716 arg->ret = err; 1717 } 1718 1719 /* 1720 * Common code for kill process group/broadcast kill. 1721 * cp is calling process. 1722 */ 1723 static int 1724 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1725 { 1726 struct proc *p; 1727 struct pgrp *pgrp; 1728 struct killpg1_ctx arg; 1729 1730 arg.td = td; 1731 arg.ksi = ksi; 1732 arg.sig = sig; 1733 arg.sent = false; 1734 arg.found = false; 1735 arg.ret = 0; 1736 if (all) { 1737 /* 1738 * broadcast 1739 */ 1740 sx_slock(&allproc_lock); 1741 FOREACH_PROC_IN_SYSTEM(p) { 1742 killpg1_sendsig(p, true, &arg); 1743 } 1744 sx_sunlock(&allproc_lock); 1745 } else { 1746 sx_slock(&proctree_lock); 1747 if (pgid == 0) { 1748 /* 1749 * zero pgid means send to my process group. 1750 */ 1751 pgrp = td->td_proc->p_pgrp; 1752 PGRP_LOCK(pgrp); 1753 } else { 1754 pgrp = pgfind(pgid); 1755 if (pgrp == NULL) { 1756 sx_sunlock(&proctree_lock); 1757 return (ESRCH); 1758 } 1759 } 1760 sx_sunlock(&proctree_lock); 1761 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1762 killpg1_sendsig(p, false, &arg); 1763 } 1764 PGRP_UNLOCK(pgrp); 1765 } 1766 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1767 if (arg.ret == 0 && !arg.sent) 1768 arg.ret = arg.found ? EPERM : ESRCH; 1769 return (arg.ret); 1770 } 1771 1772 #ifndef _SYS_SYSPROTO_H_ 1773 struct kill_args { 1774 int pid; 1775 int signum; 1776 }; 1777 #endif 1778 /* ARGSUSED */ 1779 int 1780 sys_kill(struct thread *td, struct kill_args *uap) 1781 { 1782 1783 return (kern_kill(td, uap->pid, uap->signum)); 1784 } 1785 1786 int 1787 kern_kill(struct thread *td, pid_t pid, int signum) 1788 { 1789 ksiginfo_t ksi; 1790 struct proc *p; 1791 int error; 1792 1793 /* 1794 * A process in capability mode can send signals only to himself. 1795 * The main rationale behind this is that abort(3) is implemented as 1796 * kill(getpid(), SIGABRT). 1797 */ 1798 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1799 return (ECAPMODE); 1800 1801 AUDIT_ARG_SIGNUM(signum); 1802 AUDIT_ARG_PID(pid); 1803 if ((u_int)signum > _SIG_MAXSIG) 1804 return (EINVAL); 1805 1806 ksiginfo_init(&ksi); 1807 ksi.ksi_signo = signum; 1808 ksi.ksi_code = SI_USER; 1809 ksi.ksi_pid = td->td_proc->p_pid; 1810 ksi.ksi_uid = td->td_ucred->cr_ruid; 1811 1812 if (pid > 0) { 1813 /* kill single process */ 1814 if ((p = pfind_any(pid)) == NULL) 1815 return (ESRCH); 1816 AUDIT_ARG_PROCESS(p); 1817 error = p_cansignal(td, p, signum); 1818 if (error == 0 && signum) 1819 pksignal(p, signum, &ksi); 1820 PROC_UNLOCK(p); 1821 return (error); 1822 } 1823 switch (pid) { 1824 case -1: /* broadcast signal */ 1825 return (killpg1(td, signum, 0, 1, &ksi)); 1826 case 0: /* signal own process group */ 1827 return (killpg1(td, signum, 0, 0, &ksi)); 1828 default: /* negative explicit process group */ 1829 return (killpg1(td, signum, -pid, 0, &ksi)); 1830 } 1831 /* NOTREACHED */ 1832 } 1833 1834 int 1835 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1836 { 1837 struct proc *p; 1838 int error; 1839 1840 AUDIT_ARG_SIGNUM(uap->signum); 1841 AUDIT_ARG_FD(uap->fd); 1842 if ((u_int)uap->signum > _SIG_MAXSIG) 1843 return (EINVAL); 1844 1845 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1846 if (error) 1847 return (error); 1848 AUDIT_ARG_PROCESS(p); 1849 error = p_cansignal(td, p, uap->signum); 1850 if (error == 0 && uap->signum) 1851 kern_psignal(p, uap->signum); 1852 PROC_UNLOCK(p); 1853 return (error); 1854 } 1855 1856 #if defined(COMPAT_43) 1857 #ifndef _SYS_SYSPROTO_H_ 1858 struct okillpg_args { 1859 int pgid; 1860 int signum; 1861 }; 1862 #endif 1863 /* ARGSUSED */ 1864 int 1865 okillpg(struct thread *td, struct okillpg_args *uap) 1866 { 1867 ksiginfo_t ksi; 1868 1869 AUDIT_ARG_SIGNUM(uap->signum); 1870 AUDIT_ARG_PID(uap->pgid); 1871 if ((u_int)uap->signum > _SIG_MAXSIG) 1872 return (EINVAL); 1873 1874 ksiginfo_init(&ksi); 1875 ksi.ksi_signo = uap->signum; 1876 ksi.ksi_code = SI_USER; 1877 ksi.ksi_pid = td->td_proc->p_pid; 1878 ksi.ksi_uid = td->td_ucred->cr_ruid; 1879 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1880 } 1881 #endif /* COMPAT_43 */ 1882 1883 #ifndef _SYS_SYSPROTO_H_ 1884 struct sigqueue_args { 1885 pid_t pid; 1886 int signum; 1887 /* union sigval */ void *value; 1888 }; 1889 #endif 1890 int 1891 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1892 { 1893 union sigval sv; 1894 1895 sv.sival_ptr = uap->value; 1896 1897 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1898 } 1899 1900 int 1901 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1902 { 1903 ksiginfo_t ksi; 1904 struct proc *p; 1905 int error; 1906 1907 if ((u_int)signum > _SIG_MAXSIG) 1908 return (EINVAL); 1909 1910 /* 1911 * Specification says sigqueue can only send signal to 1912 * single process. 1913 */ 1914 if (pid <= 0) 1915 return (EINVAL); 1916 1917 if ((p = pfind_any(pid)) == NULL) 1918 return (ESRCH); 1919 error = p_cansignal(td, p, signum); 1920 if (error == 0 && signum != 0) { 1921 ksiginfo_init(&ksi); 1922 ksi.ksi_flags = KSI_SIGQ; 1923 ksi.ksi_signo = signum; 1924 ksi.ksi_code = SI_QUEUE; 1925 ksi.ksi_pid = td->td_proc->p_pid; 1926 ksi.ksi_uid = td->td_ucred->cr_ruid; 1927 ksi.ksi_value = *value; 1928 error = pksignal(p, ksi.ksi_signo, &ksi); 1929 } 1930 PROC_UNLOCK(p); 1931 return (error); 1932 } 1933 1934 /* 1935 * Send a signal to a process group. 1936 */ 1937 void 1938 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1939 { 1940 struct pgrp *pgrp; 1941 1942 if (pgid != 0) { 1943 sx_slock(&proctree_lock); 1944 pgrp = pgfind(pgid); 1945 sx_sunlock(&proctree_lock); 1946 if (pgrp != NULL) { 1947 pgsignal(pgrp, sig, 0, ksi); 1948 PGRP_UNLOCK(pgrp); 1949 } 1950 } 1951 } 1952 1953 /* 1954 * Send a signal to a process group. If checktty is 1, 1955 * limit to members which have a controlling terminal. 1956 */ 1957 void 1958 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1959 { 1960 struct proc *p; 1961 1962 if (pgrp) { 1963 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1964 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1965 PROC_LOCK(p); 1966 if (p->p_state == PRS_NORMAL && 1967 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1968 pksignal(p, sig, ksi); 1969 PROC_UNLOCK(p); 1970 } 1971 } 1972 } 1973 1974 /* 1975 * Recalculate the signal mask and reset the signal disposition after 1976 * usermode frame for delivery is formed. Should be called after 1977 * mach-specific routine, because sysent->sv_sendsig() needs correct 1978 * ps_siginfo and signal mask. 1979 */ 1980 static void 1981 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1982 { 1983 sigset_t mask; 1984 1985 mtx_assert(&ps->ps_mtx, MA_OWNED); 1986 td->td_ru.ru_nsignals++; 1987 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1988 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1989 SIGADDSET(mask, sig); 1990 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1991 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1992 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1993 sigdflt(ps, sig); 1994 } 1995 1996 /* 1997 * Send a signal caused by a trap to the current thread. If it will be 1998 * caught immediately, deliver it with correct code. Otherwise, post it 1999 * normally. 2000 */ 2001 void 2002 trapsignal(struct thread *td, ksiginfo_t *ksi) 2003 { 2004 struct sigacts *ps; 2005 struct proc *p; 2006 sigset_t sigmask; 2007 int code, sig; 2008 2009 p = td->td_proc; 2010 sig = ksi->ksi_signo; 2011 code = ksi->ksi_code; 2012 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2013 2014 sigfastblock_fetch(td); 2015 PROC_LOCK(p); 2016 ps = p->p_sigacts; 2017 mtx_lock(&ps->ps_mtx); 2018 sigmask = td->td_sigmask; 2019 if (td->td_sigblock_val != 0) 2020 SIGSETOR(sigmask, fastblock_mask); 2021 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2022 !SIGISMEMBER(sigmask, sig)) { 2023 #ifdef KTRACE 2024 if (KTRPOINT(curthread, KTR_PSIG)) 2025 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2026 &td->td_sigmask, code); 2027 #endif 2028 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2029 ksi, &td->td_sigmask); 2030 postsig_done(sig, td, ps); 2031 mtx_unlock(&ps->ps_mtx); 2032 } else { 2033 /* 2034 * Avoid a possible infinite loop if the thread 2035 * masking the signal or process is ignoring the 2036 * signal. 2037 */ 2038 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2039 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2040 SIGDELSET(td->td_sigmask, sig); 2041 SIGDELSET(ps->ps_sigcatch, sig); 2042 SIGDELSET(ps->ps_sigignore, sig); 2043 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2044 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2045 td->td_sigblock_val = 0; 2046 } 2047 mtx_unlock(&ps->ps_mtx); 2048 p->p_sig = sig; /* XXX to verify code */ 2049 tdsendsignal(p, td, sig, ksi); 2050 } 2051 PROC_UNLOCK(p); 2052 } 2053 2054 static struct thread * 2055 sigtd(struct proc *p, int sig, bool fast_sigblock) 2056 { 2057 struct thread *td, *signal_td; 2058 2059 PROC_LOCK_ASSERT(p, MA_OWNED); 2060 MPASS(!fast_sigblock || p == curproc); 2061 2062 /* 2063 * Check if current thread can handle the signal without 2064 * switching context to another thread. 2065 */ 2066 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2067 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2068 return (curthread); 2069 signal_td = NULL; 2070 FOREACH_THREAD_IN_PROC(p, td) { 2071 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2072 td != curthread || td->td_sigblock_val == 0)) { 2073 signal_td = td; 2074 break; 2075 } 2076 } 2077 if (signal_td == NULL) 2078 signal_td = FIRST_THREAD_IN_PROC(p); 2079 return (signal_td); 2080 } 2081 2082 /* 2083 * Send the signal to the process. If the signal has an action, the action 2084 * is usually performed by the target process rather than the caller; we add 2085 * the signal to the set of pending signals for the process. 2086 * 2087 * Exceptions: 2088 * o When a stop signal is sent to a sleeping process that takes the 2089 * default action, the process is stopped without awakening it. 2090 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2091 * regardless of the signal action (eg, blocked or ignored). 2092 * 2093 * Other ignored signals are discarded immediately. 2094 * 2095 * NB: This function may be entered from the debugger via the "kill" DDB 2096 * command. There is little that can be done to mitigate the possibly messy 2097 * side effects of this unwise possibility. 2098 */ 2099 void 2100 kern_psignal(struct proc *p, int sig) 2101 { 2102 ksiginfo_t ksi; 2103 2104 ksiginfo_init(&ksi); 2105 ksi.ksi_signo = sig; 2106 ksi.ksi_code = SI_KERNEL; 2107 (void) tdsendsignal(p, NULL, sig, &ksi); 2108 } 2109 2110 int 2111 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2112 { 2113 2114 return (tdsendsignal(p, NULL, sig, ksi)); 2115 } 2116 2117 /* Utility function for finding a thread to send signal event to. */ 2118 int 2119 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2120 { 2121 struct thread *td; 2122 2123 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2124 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2125 if (td == NULL) 2126 return (ESRCH); 2127 *ttd = td; 2128 } else { 2129 *ttd = NULL; 2130 PROC_LOCK(p); 2131 } 2132 return (0); 2133 } 2134 2135 void 2136 tdsignal(struct thread *td, int sig) 2137 { 2138 ksiginfo_t ksi; 2139 2140 ksiginfo_init(&ksi); 2141 ksi.ksi_signo = sig; 2142 ksi.ksi_code = SI_KERNEL; 2143 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2144 } 2145 2146 void 2147 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2148 { 2149 2150 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2151 } 2152 2153 int 2154 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2155 { 2156 sig_t action; 2157 sigqueue_t *sigqueue; 2158 int prop; 2159 struct sigacts *ps; 2160 int intrval; 2161 int ret = 0; 2162 int wakeup_swapper; 2163 2164 MPASS(td == NULL || p == td->td_proc); 2165 PROC_LOCK_ASSERT(p, MA_OWNED); 2166 2167 if (!_SIG_VALID(sig)) 2168 panic("%s(): invalid signal %d", __func__, sig); 2169 2170 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2171 2172 /* 2173 * IEEE Std 1003.1-2001: return success when killing a zombie. 2174 */ 2175 if (p->p_state == PRS_ZOMBIE) { 2176 if (ksi && (ksi->ksi_flags & KSI_INS)) 2177 ksiginfo_tryfree(ksi); 2178 return (ret); 2179 } 2180 2181 ps = p->p_sigacts; 2182 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2183 prop = sigprop(sig); 2184 2185 if (td == NULL) { 2186 td = sigtd(p, sig, false); 2187 sigqueue = &p->p_sigqueue; 2188 } else 2189 sigqueue = &td->td_sigqueue; 2190 2191 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2192 2193 /* 2194 * If the signal is being ignored, 2195 * then we forget about it immediately. 2196 * (Note: we don't set SIGCONT in ps_sigignore, 2197 * and if it is set to SIG_IGN, 2198 * action will be SIG_DFL here.) 2199 */ 2200 mtx_lock(&ps->ps_mtx); 2201 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2202 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2203 2204 mtx_unlock(&ps->ps_mtx); 2205 if (ksi && (ksi->ksi_flags & KSI_INS)) 2206 ksiginfo_tryfree(ksi); 2207 return (ret); 2208 } 2209 if (SIGISMEMBER(td->td_sigmask, sig)) 2210 action = SIG_HOLD; 2211 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2212 action = SIG_CATCH; 2213 else 2214 action = SIG_DFL; 2215 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2216 intrval = EINTR; 2217 else 2218 intrval = ERESTART; 2219 mtx_unlock(&ps->ps_mtx); 2220 2221 if (prop & SIGPROP_CONT) 2222 sigqueue_delete_stopmask_proc(p); 2223 else if (prop & SIGPROP_STOP) { 2224 /* 2225 * If sending a tty stop signal to a member of an orphaned 2226 * process group, discard the signal here if the action 2227 * is default; don't stop the process below if sleeping, 2228 * and don't clear any pending SIGCONT. 2229 */ 2230 if ((prop & SIGPROP_TTYSTOP) && 2231 (p->p_pgrp->pg_jobc == 0) && 2232 (action == SIG_DFL)) { 2233 if (ksi && (ksi->ksi_flags & KSI_INS)) 2234 ksiginfo_tryfree(ksi); 2235 return (ret); 2236 } 2237 sigqueue_delete_proc(p, SIGCONT); 2238 if (p->p_flag & P_CONTINUED) { 2239 p->p_flag &= ~P_CONTINUED; 2240 PROC_LOCK(p->p_pptr); 2241 sigqueue_take(p->p_ksi); 2242 PROC_UNLOCK(p->p_pptr); 2243 } 2244 } 2245 2246 ret = sigqueue_add(sigqueue, sig, ksi); 2247 if (ret != 0) 2248 return (ret); 2249 signotify(td); 2250 /* 2251 * Defer further processing for signals which are held, 2252 * except that stopped processes must be continued by SIGCONT. 2253 */ 2254 if (action == SIG_HOLD && 2255 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2256 return (ret); 2257 2258 /* SIGKILL: Remove procfs STOPEVENTs. */ 2259 if (sig == SIGKILL) { 2260 /* from procfs_ioctl.c: PIOCBIC */ 2261 p->p_stops = 0; 2262 /* from procfs_ioctl.c: PIOCCONT */ 2263 p->p_step = 0; 2264 wakeup(&p->p_step); 2265 } 2266 wakeup_swapper = 0; 2267 2268 /* 2269 * Some signals have a process-wide effect and a per-thread 2270 * component. Most processing occurs when the process next 2271 * tries to cross the user boundary, however there are some 2272 * times when processing needs to be done immediately, such as 2273 * waking up threads so that they can cross the user boundary. 2274 * We try to do the per-process part here. 2275 */ 2276 if (P_SHOULDSTOP(p)) { 2277 KASSERT(!(p->p_flag & P_WEXIT), 2278 ("signal to stopped but exiting process")); 2279 if (sig == SIGKILL) { 2280 /* 2281 * If traced process is already stopped, 2282 * then no further action is necessary. 2283 */ 2284 if (p->p_flag & P_TRACED) 2285 goto out; 2286 /* 2287 * SIGKILL sets process running. 2288 * It will die elsewhere. 2289 * All threads must be restarted. 2290 */ 2291 p->p_flag &= ~P_STOPPED_SIG; 2292 goto runfast; 2293 } 2294 2295 if (prop & SIGPROP_CONT) { 2296 /* 2297 * If traced process is already stopped, 2298 * then no further action is necessary. 2299 */ 2300 if (p->p_flag & P_TRACED) 2301 goto out; 2302 /* 2303 * If SIGCONT is default (or ignored), we continue the 2304 * process but don't leave the signal in sigqueue as 2305 * it has no further action. If SIGCONT is held, we 2306 * continue the process and leave the signal in 2307 * sigqueue. If the process catches SIGCONT, let it 2308 * handle the signal itself. If it isn't waiting on 2309 * an event, it goes back to run state. 2310 * Otherwise, process goes back to sleep state. 2311 */ 2312 p->p_flag &= ~P_STOPPED_SIG; 2313 PROC_SLOCK(p); 2314 if (p->p_numthreads == p->p_suspcount) { 2315 PROC_SUNLOCK(p); 2316 p->p_flag |= P_CONTINUED; 2317 p->p_xsig = SIGCONT; 2318 PROC_LOCK(p->p_pptr); 2319 childproc_continued(p); 2320 PROC_UNLOCK(p->p_pptr); 2321 PROC_SLOCK(p); 2322 } 2323 if (action == SIG_DFL) { 2324 thread_unsuspend(p); 2325 PROC_SUNLOCK(p); 2326 sigqueue_delete(sigqueue, sig); 2327 goto out; 2328 } 2329 if (action == SIG_CATCH) { 2330 /* 2331 * The process wants to catch it so it needs 2332 * to run at least one thread, but which one? 2333 */ 2334 PROC_SUNLOCK(p); 2335 goto runfast; 2336 } 2337 /* 2338 * The signal is not ignored or caught. 2339 */ 2340 thread_unsuspend(p); 2341 PROC_SUNLOCK(p); 2342 goto out; 2343 } 2344 2345 if (prop & SIGPROP_STOP) { 2346 /* 2347 * If traced process is already stopped, 2348 * then no further action is necessary. 2349 */ 2350 if (p->p_flag & P_TRACED) 2351 goto out; 2352 /* 2353 * Already stopped, don't need to stop again 2354 * (If we did the shell could get confused). 2355 * Just make sure the signal STOP bit set. 2356 */ 2357 p->p_flag |= P_STOPPED_SIG; 2358 sigqueue_delete(sigqueue, sig); 2359 goto out; 2360 } 2361 2362 /* 2363 * All other kinds of signals: 2364 * If a thread is sleeping interruptibly, simulate a 2365 * wakeup so that when it is continued it will be made 2366 * runnable and can look at the signal. However, don't make 2367 * the PROCESS runnable, leave it stopped. 2368 * It may run a bit until it hits a thread_suspend_check(). 2369 */ 2370 PROC_SLOCK(p); 2371 thread_lock(td); 2372 if (TD_CAN_ABORT(td)) 2373 wakeup_swapper = sleepq_abort(td, intrval); 2374 else 2375 thread_unlock(td); 2376 PROC_SUNLOCK(p); 2377 goto out; 2378 /* 2379 * Mutexes are short lived. Threads waiting on them will 2380 * hit thread_suspend_check() soon. 2381 */ 2382 } else if (p->p_state == PRS_NORMAL) { 2383 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2384 tdsigwakeup(td, sig, action, intrval); 2385 goto out; 2386 } 2387 2388 MPASS(action == SIG_DFL); 2389 2390 if (prop & SIGPROP_STOP) { 2391 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2392 goto out; 2393 p->p_flag |= P_STOPPED_SIG; 2394 p->p_xsig = sig; 2395 PROC_SLOCK(p); 2396 wakeup_swapper = sig_suspend_threads(td, p, 1); 2397 if (p->p_numthreads == p->p_suspcount) { 2398 /* 2399 * only thread sending signal to another 2400 * process can reach here, if thread is sending 2401 * signal to its process, because thread does 2402 * not suspend itself here, p_numthreads 2403 * should never be equal to p_suspcount. 2404 */ 2405 thread_stopped(p); 2406 PROC_SUNLOCK(p); 2407 sigqueue_delete_proc(p, p->p_xsig); 2408 } else 2409 PROC_SUNLOCK(p); 2410 goto out; 2411 } 2412 } else { 2413 /* Not in "NORMAL" state. discard the signal. */ 2414 sigqueue_delete(sigqueue, sig); 2415 goto out; 2416 } 2417 2418 /* 2419 * The process is not stopped so we need to apply the signal to all the 2420 * running threads. 2421 */ 2422 runfast: 2423 tdsigwakeup(td, sig, action, intrval); 2424 PROC_SLOCK(p); 2425 thread_unsuspend(p); 2426 PROC_SUNLOCK(p); 2427 out: 2428 /* If we jump here, proc slock should not be owned. */ 2429 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2430 if (wakeup_swapper) 2431 kick_proc0(); 2432 2433 return (ret); 2434 } 2435 2436 /* 2437 * The force of a signal has been directed against a single 2438 * thread. We need to see what we can do about knocking it 2439 * out of any sleep it may be in etc. 2440 */ 2441 static void 2442 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2443 { 2444 struct proc *p = td->td_proc; 2445 int prop, wakeup_swapper; 2446 2447 PROC_LOCK_ASSERT(p, MA_OWNED); 2448 prop = sigprop(sig); 2449 2450 PROC_SLOCK(p); 2451 thread_lock(td); 2452 /* 2453 * Bring the priority of a thread up if we want it to get 2454 * killed in this lifetime. Be careful to avoid bumping the 2455 * priority of the idle thread, since we still allow to signal 2456 * kernel processes. 2457 */ 2458 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2459 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2460 sched_prio(td, PUSER); 2461 if (TD_ON_SLEEPQ(td)) { 2462 /* 2463 * If thread is sleeping uninterruptibly 2464 * we can't interrupt the sleep... the signal will 2465 * be noticed when the process returns through 2466 * trap() or syscall(). 2467 */ 2468 if ((td->td_flags & TDF_SINTR) == 0) 2469 goto out; 2470 /* 2471 * If SIGCONT is default (or ignored) and process is 2472 * asleep, we are finished; the process should not 2473 * be awakened. 2474 */ 2475 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2476 thread_unlock(td); 2477 PROC_SUNLOCK(p); 2478 sigqueue_delete(&p->p_sigqueue, sig); 2479 /* 2480 * It may be on either list in this state. 2481 * Remove from both for now. 2482 */ 2483 sigqueue_delete(&td->td_sigqueue, sig); 2484 return; 2485 } 2486 2487 /* 2488 * Don't awaken a sleeping thread for SIGSTOP if the 2489 * STOP signal is deferred. 2490 */ 2491 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2492 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2493 goto out; 2494 2495 /* 2496 * Give low priority threads a better chance to run. 2497 */ 2498 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2499 sched_prio(td, PUSER); 2500 2501 wakeup_swapper = sleepq_abort(td, intrval); 2502 PROC_SUNLOCK(p); 2503 if (wakeup_swapper) 2504 kick_proc0(); 2505 return; 2506 } 2507 2508 /* 2509 * Other states do nothing with the signal immediately, 2510 * other than kicking ourselves if we are running. 2511 * It will either never be noticed, or noticed very soon. 2512 */ 2513 #ifdef SMP 2514 if (TD_IS_RUNNING(td) && td != curthread) 2515 forward_signal(td); 2516 #endif 2517 2518 out: 2519 PROC_SUNLOCK(p); 2520 thread_unlock(td); 2521 } 2522 2523 static int 2524 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2525 { 2526 struct thread *td2; 2527 int wakeup_swapper; 2528 2529 PROC_LOCK_ASSERT(p, MA_OWNED); 2530 PROC_SLOCK_ASSERT(p, MA_OWNED); 2531 MPASS(sending || td == curthread); 2532 2533 wakeup_swapper = 0; 2534 FOREACH_THREAD_IN_PROC(p, td2) { 2535 thread_lock(td2); 2536 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2537 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2538 (td2->td_flags & TDF_SINTR)) { 2539 if (td2->td_flags & TDF_SBDRY) { 2540 /* 2541 * Once a thread is asleep with 2542 * TDF_SBDRY and without TDF_SERESTART 2543 * or TDF_SEINTR set, it should never 2544 * become suspended due to this check. 2545 */ 2546 KASSERT(!TD_IS_SUSPENDED(td2), 2547 ("thread with deferred stops suspended")); 2548 if (TD_SBDRY_INTR(td2)) { 2549 wakeup_swapper |= sleepq_abort(td2, 2550 TD_SBDRY_ERRNO(td2)); 2551 continue; 2552 } 2553 } else if (!TD_IS_SUSPENDED(td2)) 2554 thread_suspend_one(td2); 2555 } else if (!TD_IS_SUSPENDED(td2)) { 2556 if (sending || td != td2) 2557 td2->td_flags |= TDF_ASTPENDING; 2558 #ifdef SMP 2559 if (TD_IS_RUNNING(td2) && td2 != td) 2560 forward_signal(td2); 2561 #endif 2562 } 2563 thread_unlock(td2); 2564 } 2565 return (wakeup_swapper); 2566 } 2567 2568 /* 2569 * Stop the process for an event deemed interesting to the debugger. If si is 2570 * non-NULL, this is a signal exchange; the new signal requested by the 2571 * debugger will be returned for handling. If si is NULL, this is some other 2572 * type of interesting event. The debugger may request a signal be delivered in 2573 * that case as well, however it will be deferred until it can be handled. 2574 */ 2575 int 2576 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2577 { 2578 struct proc *p = td->td_proc; 2579 struct thread *td2; 2580 ksiginfo_t ksi; 2581 2582 PROC_LOCK_ASSERT(p, MA_OWNED); 2583 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2584 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2585 &p->p_mtx.lock_object, "Stopping for traced signal"); 2586 2587 td->td_xsig = sig; 2588 2589 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2590 td->td_dbgflags |= TDB_XSIG; 2591 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2592 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2593 PROC_SLOCK(p); 2594 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2595 if (P_KILLED(p)) { 2596 /* 2597 * Ensure that, if we've been PT_KILLed, the 2598 * exit status reflects that. Another thread 2599 * may also be in ptracestop(), having just 2600 * received the SIGKILL, but this thread was 2601 * unsuspended first. 2602 */ 2603 td->td_dbgflags &= ~TDB_XSIG; 2604 td->td_xsig = SIGKILL; 2605 p->p_ptevents = 0; 2606 break; 2607 } 2608 if (p->p_flag & P_SINGLE_EXIT && 2609 !(td->td_dbgflags & TDB_EXIT)) { 2610 /* 2611 * Ignore ptrace stops except for thread exit 2612 * events when the process exits. 2613 */ 2614 td->td_dbgflags &= ~TDB_XSIG; 2615 PROC_SUNLOCK(p); 2616 return (0); 2617 } 2618 2619 /* 2620 * Make wait(2) work. Ensure that right after the 2621 * attach, the thread which was decided to become the 2622 * leader of attach gets reported to the waiter. 2623 * Otherwise, just avoid overwriting another thread's 2624 * assignment to p_xthread. If another thread has 2625 * already set p_xthread, the current thread will get 2626 * a chance to report itself upon the next iteration. 2627 */ 2628 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2629 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2630 p->p_xthread == NULL)) { 2631 p->p_xsig = sig; 2632 p->p_xthread = td; 2633 2634 /* 2635 * If we are on sleepqueue already, 2636 * let sleepqueue code decide if it 2637 * needs to go sleep after attach. 2638 */ 2639 if (td->td_wchan == NULL) 2640 td->td_dbgflags &= ~TDB_FSTP; 2641 2642 p->p_flag2 &= ~P2_PTRACE_FSTP; 2643 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2644 sig_suspend_threads(td, p, 0); 2645 } 2646 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2647 td->td_dbgflags &= ~TDB_STOPATFORK; 2648 } 2649 stopme: 2650 thread_suspend_switch(td, p); 2651 if (p->p_xthread == td) 2652 p->p_xthread = NULL; 2653 if (!(p->p_flag & P_TRACED)) 2654 break; 2655 if (td->td_dbgflags & TDB_SUSPEND) { 2656 if (p->p_flag & P_SINGLE_EXIT) 2657 break; 2658 goto stopme; 2659 } 2660 } 2661 PROC_SUNLOCK(p); 2662 } 2663 2664 if (si != NULL && sig == td->td_xsig) { 2665 /* Parent wants us to take the original signal unchanged. */ 2666 si->ksi_flags |= KSI_HEAD; 2667 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2668 si->ksi_signo = 0; 2669 } else if (td->td_xsig != 0) { 2670 /* 2671 * If parent wants us to take a new signal, then it will leave 2672 * it in td->td_xsig; otherwise we just look for signals again. 2673 */ 2674 ksiginfo_init(&ksi); 2675 ksi.ksi_signo = td->td_xsig; 2676 ksi.ksi_flags |= KSI_PTRACE; 2677 td2 = sigtd(p, td->td_xsig, false); 2678 tdsendsignal(p, td2, td->td_xsig, &ksi); 2679 if (td != td2) 2680 return (0); 2681 } 2682 2683 return (td->td_xsig); 2684 } 2685 2686 void 2687 reschedule_signals(struct proc *p, sigset_t block, int flags) 2688 { 2689 struct sigacts *ps; 2690 struct thread *td; 2691 int sig; 2692 bool fastblk, pslocked; 2693 2694 PROC_LOCK_ASSERT(p, MA_OWNED); 2695 ps = p->p_sigacts; 2696 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2697 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2698 if (SIGISEMPTY(p->p_siglist)) 2699 return; 2700 SIGSETAND(block, p->p_siglist); 2701 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2702 while ((sig = sig_ffs(&block)) != 0) { 2703 SIGDELSET(block, sig); 2704 td = sigtd(p, sig, fastblk); 2705 2706 /* 2707 * If sigtd() selected us despite sigfastblock is 2708 * blocking, do not activate AST or wake us, to avoid 2709 * loop in AST handler. 2710 */ 2711 if (fastblk && td == curthread) 2712 continue; 2713 2714 signotify(td); 2715 if (!pslocked) 2716 mtx_lock(&ps->ps_mtx); 2717 if (p->p_flag & P_TRACED || 2718 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2719 !SIGISMEMBER(td->td_sigmask, sig))) { 2720 tdsigwakeup(td, sig, SIG_CATCH, 2721 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2722 ERESTART)); 2723 } 2724 if (!pslocked) 2725 mtx_unlock(&ps->ps_mtx); 2726 } 2727 } 2728 2729 void 2730 tdsigcleanup(struct thread *td) 2731 { 2732 struct proc *p; 2733 sigset_t unblocked; 2734 2735 p = td->td_proc; 2736 PROC_LOCK_ASSERT(p, MA_OWNED); 2737 2738 sigqueue_flush(&td->td_sigqueue); 2739 if (p->p_numthreads == 1) 2740 return; 2741 2742 /* 2743 * Since we cannot handle signals, notify signal post code 2744 * about this by filling the sigmask. 2745 * 2746 * Also, if needed, wake up thread(s) that do not block the 2747 * same signals as the exiting thread, since the thread might 2748 * have been selected for delivery and woken up. 2749 */ 2750 SIGFILLSET(unblocked); 2751 SIGSETNAND(unblocked, td->td_sigmask); 2752 SIGFILLSET(td->td_sigmask); 2753 reschedule_signals(p, unblocked, 0); 2754 2755 } 2756 2757 static int 2758 sigdeferstop_curr_flags(int cflags) 2759 { 2760 2761 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2762 (cflags & TDF_SBDRY) != 0); 2763 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2764 } 2765 2766 /* 2767 * Defer the delivery of SIGSTOP for the current thread, according to 2768 * the requested mode. Returns previous flags, which must be restored 2769 * by sigallowstop(). 2770 * 2771 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2772 * cleared by the current thread, which allow the lock-less read-only 2773 * accesses below. 2774 */ 2775 int 2776 sigdeferstop_impl(int mode) 2777 { 2778 struct thread *td; 2779 int cflags, nflags; 2780 2781 td = curthread; 2782 cflags = sigdeferstop_curr_flags(td->td_flags); 2783 switch (mode) { 2784 case SIGDEFERSTOP_NOP: 2785 nflags = cflags; 2786 break; 2787 case SIGDEFERSTOP_OFF: 2788 nflags = 0; 2789 break; 2790 case SIGDEFERSTOP_SILENT: 2791 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2792 break; 2793 case SIGDEFERSTOP_EINTR: 2794 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2795 break; 2796 case SIGDEFERSTOP_ERESTART: 2797 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2798 break; 2799 default: 2800 panic("sigdeferstop: invalid mode %x", mode); 2801 break; 2802 } 2803 if (cflags == nflags) 2804 return (SIGDEFERSTOP_VAL_NCHG); 2805 thread_lock(td); 2806 td->td_flags = (td->td_flags & ~cflags) | nflags; 2807 thread_unlock(td); 2808 return (cflags); 2809 } 2810 2811 /* 2812 * Restores the STOP handling mode, typically permitting the delivery 2813 * of SIGSTOP for the current thread. This does not immediately 2814 * suspend if a stop was posted. Instead, the thread will suspend 2815 * either via ast() or a subsequent interruptible sleep. 2816 */ 2817 void 2818 sigallowstop_impl(int prev) 2819 { 2820 struct thread *td; 2821 int cflags; 2822 2823 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2824 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2825 ("sigallowstop: incorrect previous mode %x", prev)); 2826 td = curthread; 2827 cflags = sigdeferstop_curr_flags(td->td_flags); 2828 if (cflags != prev) { 2829 thread_lock(td); 2830 td->td_flags = (td->td_flags & ~cflags) | prev; 2831 thread_unlock(td); 2832 } 2833 } 2834 2835 /* 2836 * If the current process has received a signal (should be caught or cause 2837 * termination, should interrupt current syscall), return the signal number. 2838 * Stop signals with default action are processed immediately, then cleared; 2839 * they aren't returned. This is checked after each entry to the system for 2840 * a syscall or trap (though this can usually be done without calling issignal 2841 * by checking the pending signal masks in cursig.) The normal call 2842 * sequence is 2843 * 2844 * while (sig = cursig(curthread)) 2845 * postsig(sig); 2846 */ 2847 static int 2848 issignal(struct thread *td) 2849 { 2850 struct proc *p; 2851 struct sigacts *ps; 2852 struct sigqueue *queue; 2853 sigset_t sigpending; 2854 ksiginfo_t ksi; 2855 int prop, sig, traced; 2856 2857 p = td->td_proc; 2858 ps = p->p_sigacts; 2859 mtx_assert(&ps->ps_mtx, MA_OWNED); 2860 PROC_LOCK_ASSERT(p, MA_OWNED); 2861 for (;;) { 2862 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2863 2864 sigpending = td->td_sigqueue.sq_signals; 2865 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2866 SIGSETNAND(sigpending, td->td_sigmask); 2867 2868 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2869 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2870 SIG_STOPSIGMASK(sigpending); 2871 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2872 return (0); 2873 2874 /* 2875 * Do fast sigblock if requested by usermode. Since 2876 * we do know that there was a signal pending at this 2877 * point, set the FAST_SIGBLOCK_PEND as indicator for 2878 * usermode to perform a dummy call to 2879 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2880 * delivery of postponed pending signal. 2881 */ 2882 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2883 if (td->td_sigblock_val != 0) 2884 SIGSETNAND(sigpending, fastblock_mask); 2885 if (SIGISEMPTY(sigpending)) { 2886 td->td_pflags |= TDP_SIGFASTPENDING; 2887 return (0); 2888 } 2889 } 2890 2891 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2892 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2893 SIGISMEMBER(sigpending, SIGSTOP)) { 2894 /* 2895 * If debugger just attached, always consume 2896 * SIGSTOP from ptrace(PT_ATTACH) first, to 2897 * execute the debugger attach ritual in 2898 * order. 2899 */ 2900 sig = SIGSTOP; 2901 td->td_dbgflags |= TDB_FSTP; 2902 } else { 2903 sig = sig_ffs(&sigpending); 2904 } 2905 2906 if (p->p_stops & S_SIG) { 2907 mtx_unlock(&ps->ps_mtx); 2908 stopevent(p, S_SIG, sig); 2909 mtx_lock(&ps->ps_mtx); 2910 } 2911 2912 /* 2913 * We should see pending but ignored signals 2914 * only if P_TRACED was on when they were posted. 2915 */ 2916 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2917 sigqueue_delete(&td->td_sigqueue, sig); 2918 sigqueue_delete(&p->p_sigqueue, sig); 2919 continue; 2920 } 2921 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2922 /* 2923 * If traced, always stop. 2924 * Remove old signal from queue before the stop. 2925 * XXX shrug off debugger, it causes siginfo to 2926 * be thrown away. 2927 */ 2928 queue = &td->td_sigqueue; 2929 ksiginfo_init(&ksi); 2930 if (sigqueue_get(queue, sig, &ksi) == 0) { 2931 queue = &p->p_sigqueue; 2932 sigqueue_get(queue, sig, &ksi); 2933 } 2934 td->td_si = ksi.ksi_info; 2935 2936 mtx_unlock(&ps->ps_mtx); 2937 sig = ptracestop(td, sig, &ksi); 2938 mtx_lock(&ps->ps_mtx); 2939 2940 td->td_si.si_signo = 0; 2941 2942 /* 2943 * Keep looking if the debugger discarded or 2944 * replaced the signal. 2945 */ 2946 if (sig == 0) 2947 continue; 2948 2949 /* 2950 * If the signal became masked, re-queue it. 2951 */ 2952 if (SIGISMEMBER(td->td_sigmask, sig)) { 2953 ksi.ksi_flags |= KSI_HEAD; 2954 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2955 continue; 2956 } 2957 2958 /* 2959 * If the traced bit got turned off, requeue 2960 * the signal and go back up to the top to 2961 * rescan signals. This ensures that p_sig* 2962 * and p_sigact are consistent. 2963 */ 2964 if ((p->p_flag & P_TRACED) == 0) { 2965 ksi.ksi_flags |= KSI_HEAD; 2966 sigqueue_add(queue, sig, &ksi); 2967 continue; 2968 } 2969 } 2970 2971 prop = sigprop(sig); 2972 2973 /* 2974 * Decide whether the signal should be returned. 2975 * Return the signal's number, or fall through 2976 * to clear it from the pending mask. 2977 */ 2978 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2979 2980 case (intptr_t)SIG_DFL: 2981 /* 2982 * Don't take default actions on system processes. 2983 */ 2984 if (p->p_pid <= 1) { 2985 #ifdef DIAGNOSTIC 2986 /* 2987 * Are you sure you want to ignore SIGSEGV 2988 * in init? XXX 2989 */ 2990 printf("Process (pid %lu) got signal %d\n", 2991 (u_long)p->p_pid, sig); 2992 #endif 2993 break; /* == ignore */ 2994 } 2995 /* 2996 * If there is a pending stop signal to process with 2997 * default action, stop here, then clear the signal. 2998 * Traced or exiting processes should ignore stops. 2999 * Additionally, a member of an orphaned process group 3000 * should ignore tty stops. 3001 */ 3002 if (prop & SIGPROP_STOP) { 3003 if (p->p_flag & 3004 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 3005 (p->p_pgrp->pg_jobc == 0 && 3006 prop & SIGPROP_TTYSTOP)) 3007 break; /* == ignore */ 3008 if (TD_SBDRY_INTR(td)) { 3009 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3010 ("lost TDF_SBDRY")); 3011 return (-1); 3012 } 3013 mtx_unlock(&ps->ps_mtx); 3014 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3015 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3016 sigqueue_delete(&td->td_sigqueue, sig); 3017 sigqueue_delete(&p->p_sigqueue, sig); 3018 p->p_flag |= P_STOPPED_SIG; 3019 p->p_xsig = sig; 3020 PROC_SLOCK(p); 3021 sig_suspend_threads(td, p, 0); 3022 thread_suspend_switch(td, p); 3023 PROC_SUNLOCK(p); 3024 mtx_lock(&ps->ps_mtx); 3025 goto next; 3026 } else if (prop & SIGPROP_IGNORE) { 3027 /* 3028 * Except for SIGCONT, shouldn't get here. 3029 * Default action is to ignore; drop it. 3030 */ 3031 break; /* == ignore */ 3032 } else 3033 return (sig); 3034 /*NOTREACHED*/ 3035 3036 case (intptr_t)SIG_IGN: 3037 /* 3038 * Masking above should prevent us ever trying 3039 * to take action on an ignored signal other 3040 * than SIGCONT, unless process is traced. 3041 */ 3042 if ((prop & SIGPROP_CONT) == 0 && 3043 (p->p_flag & P_TRACED) == 0) 3044 printf("issignal\n"); 3045 break; /* == ignore */ 3046 3047 default: 3048 /* 3049 * This signal has an action, let 3050 * postsig() process it. 3051 */ 3052 return (sig); 3053 } 3054 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3055 sigqueue_delete(&p->p_sigqueue, sig); 3056 next:; 3057 } 3058 /* NOTREACHED */ 3059 } 3060 3061 void 3062 thread_stopped(struct proc *p) 3063 { 3064 int n; 3065 3066 PROC_LOCK_ASSERT(p, MA_OWNED); 3067 PROC_SLOCK_ASSERT(p, MA_OWNED); 3068 n = p->p_suspcount; 3069 if (p == curproc) 3070 n++; 3071 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3072 PROC_SUNLOCK(p); 3073 p->p_flag &= ~P_WAITED; 3074 PROC_LOCK(p->p_pptr); 3075 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3076 CLD_TRAPPED : CLD_STOPPED); 3077 PROC_UNLOCK(p->p_pptr); 3078 PROC_SLOCK(p); 3079 } 3080 } 3081 3082 /* 3083 * Take the action for the specified signal 3084 * from the current set of pending signals. 3085 */ 3086 int 3087 postsig(int sig) 3088 { 3089 struct thread *td; 3090 struct proc *p; 3091 struct sigacts *ps; 3092 sig_t action; 3093 ksiginfo_t ksi; 3094 sigset_t returnmask; 3095 3096 KASSERT(sig != 0, ("postsig")); 3097 3098 td = curthread; 3099 p = td->td_proc; 3100 PROC_LOCK_ASSERT(p, MA_OWNED); 3101 ps = p->p_sigacts; 3102 mtx_assert(&ps->ps_mtx, MA_OWNED); 3103 ksiginfo_init(&ksi); 3104 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3105 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3106 return (0); 3107 ksi.ksi_signo = sig; 3108 if (ksi.ksi_code == SI_TIMER) 3109 itimer_accept(p, ksi.ksi_timerid, &ksi); 3110 action = ps->ps_sigact[_SIG_IDX(sig)]; 3111 #ifdef KTRACE 3112 if (KTRPOINT(td, KTR_PSIG)) 3113 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3114 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3115 #endif 3116 if ((p->p_stops & S_SIG) != 0) { 3117 mtx_unlock(&ps->ps_mtx); 3118 stopevent(p, S_SIG, sig); 3119 mtx_lock(&ps->ps_mtx); 3120 } 3121 3122 if (action == SIG_DFL) { 3123 /* 3124 * Default action, where the default is to kill 3125 * the process. (Other cases were ignored above.) 3126 */ 3127 mtx_unlock(&ps->ps_mtx); 3128 proc_td_siginfo_capture(td, &ksi.ksi_info); 3129 sigexit(td, sig); 3130 /* NOTREACHED */ 3131 } else { 3132 /* 3133 * If we get here, the signal must be caught. 3134 */ 3135 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3136 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3137 ("postsig action: blocked sig %d", sig)); 3138 3139 /* 3140 * Set the new mask value and also defer further 3141 * occurrences of this signal. 3142 * 3143 * Special case: user has done a sigsuspend. Here the 3144 * current mask is not of interest, but rather the 3145 * mask from before the sigsuspend is what we want 3146 * restored after the signal processing is completed. 3147 */ 3148 if (td->td_pflags & TDP_OLDMASK) { 3149 returnmask = td->td_oldsigmask; 3150 td->td_pflags &= ~TDP_OLDMASK; 3151 } else 3152 returnmask = td->td_sigmask; 3153 3154 if (p->p_sig == sig) { 3155 p->p_sig = 0; 3156 } 3157 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3158 postsig_done(sig, td, ps); 3159 } 3160 return (1); 3161 } 3162 3163 void 3164 proc_wkilled(struct proc *p) 3165 { 3166 3167 PROC_LOCK_ASSERT(p, MA_OWNED); 3168 if ((p->p_flag & P_WKILLED) == 0) { 3169 p->p_flag |= P_WKILLED; 3170 /* 3171 * Notify swapper that there is a process to swap in. 3172 * The notification is racy, at worst it would take 10 3173 * seconds for the swapper process to notice. 3174 */ 3175 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3176 wakeup(&proc0); 3177 } 3178 } 3179 3180 /* 3181 * Kill the current process for stated reason. 3182 */ 3183 void 3184 killproc(struct proc *p, const char *why) 3185 { 3186 3187 PROC_LOCK_ASSERT(p, MA_OWNED); 3188 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3189 p->p_comm); 3190 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3191 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3192 p->p_ucred->cr_uid, why); 3193 proc_wkilled(p); 3194 kern_psignal(p, SIGKILL); 3195 } 3196 3197 /* 3198 * Force the current process to exit with the specified signal, dumping core 3199 * if appropriate. We bypass the normal tests for masked and caught signals, 3200 * allowing unrecoverable failures to terminate the process without changing 3201 * signal state. Mark the accounting record with the signal termination. 3202 * If dumping core, save the signal number for the debugger. Calls exit and 3203 * does not return. 3204 */ 3205 void 3206 sigexit(struct thread *td, int sig) 3207 { 3208 struct proc *p = td->td_proc; 3209 3210 PROC_LOCK_ASSERT(p, MA_OWNED); 3211 p->p_acflag |= AXSIG; 3212 /* 3213 * We must be single-threading to generate a core dump. This 3214 * ensures that the registers in the core file are up-to-date. 3215 * Also, the ELF dump handler assumes that the thread list doesn't 3216 * change out from under it. 3217 * 3218 * XXX If another thread attempts to single-thread before us 3219 * (e.g. via fork()), we won't get a dump at all. 3220 */ 3221 if ((sigprop(sig) & SIGPROP_CORE) && 3222 thread_single(p, SINGLE_NO_EXIT) == 0) { 3223 p->p_sig = sig; 3224 /* 3225 * Log signals which would cause core dumps 3226 * (Log as LOG_INFO to appease those who don't want 3227 * these messages.) 3228 * XXX : Todo, as well as euid, write out ruid too 3229 * Note that coredump() drops proc lock. 3230 */ 3231 if (coredump(td) == 0) 3232 sig |= WCOREFLAG; 3233 if (kern_logsigexit) 3234 log(LOG_INFO, 3235 "pid %d (%s), jid %d, uid %d: exited on " 3236 "signal %d%s\n", p->p_pid, p->p_comm, 3237 p->p_ucred->cr_prison->pr_id, 3238 td->td_ucred->cr_uid, 3239 sig &~ WCOREFLAG, 3240 sig & WCOREFLAG ? " (core dumped)" : ""); 3241 } else 3242 PROC_UNLOCK(p); 3243 exit1(td, 0, sig); 3244 /* NOTREACHED */ 3245 } 3246 3247 /* 3248 * Send queued SIGCHLD to parent when child process's state 3249 * is changed. 3250 */ 3251 static void 3252 sigparent(struct proc *p, int reason, int status) 3253 { 3254 PROC_LOCK_ASSERT(p, MA_OWNED); 3255 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3256 3257 if (p->p_ksi != NULL) { 3258 p->p_ksi->ksi_signo = SIGCHLD; 3259 p->p_ksi->ksi_code = reason; 3260 p->p_ksi->ksi_status = status; 3261 p->p_ksi->ksi_pid = p->p_pid; 3262 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3263 if (KSI_ONQ(p->p_ksi)) 3264 return; 3265 } 3266 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3267 } 3268 3269 static void 3270 childproc_jobstate(struct proc *p, int reason, int sig) 3271 { 3272 struct sigacts *ps; 3273 3274 PROC_LOCK_ASSERT(p, MA_OWNED); 3275 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3276 3277 /* 3278 * Wake up parent sleeping in kern_wait(), also send 3279 * SIGCHLD to parent, but SIGCHLD does not guarantee 3280 * that parent will awake, because parent may masked 3281 * the signal. 3282 */ 3283 p->p_pptr->p_flag |= P_STATCHILD; 3284 wakeup(p->p_pptr); 3285 3286 ps = p->p_pptr->p_sigacts; 3287 mtx_lock(&ps->ps_mtx); 3288 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3289 mtx_unlock(&ps->ps_mtx); 3290 sigparent(p, reason, sig); 3291 } else 3292 mtx_unlock(&ps->ps_mtx); 3293 } 3294 3295 void 3296 childproc_stopped(struct proc *p, int reason) 3297 { 3298 3299 childproc_jobstate(p, reason, p->p_xsig); 3300 } 3301 3302 void 3303 childproc_continued(struct proc *p) 3304 { 3305 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3306 } 3307 3308 void 3309 childproc_exited(struct proc *p) 3310 { 3311 int reason, status; 3312 3313 if (WCOREDUMP(p->p_xsig)) { 3314 reason = CLD_DUMPED; 3315 status = WTERMSIG(p->p_xsig); 3316 } else if (WIFSIGNALED(p->p_xsig)) { 3317 reason = CLD_KILLED; 3318 status = WTERMSIG(p->p_xsig); 3319 } else { 3320 reason = CLD_EXITED; 3321 status = p->p_xexit; 3322 } 3323 /* 3324 * XXX avoid calling wakeup(p->p_pptr), the work is 3325 * done in exit1(). 3326 */ 3327 sigparent(p, reason, status); 3328 } 3329 3330 #define MAX_NUM_CORE_FILES 100000 3331 #ifndef NUM_CORE_FILES 3332 #define NUM_CORE_FILES 5 3333 #endif 3334 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3335 static int num_cores = NUM_CORE_FILES; 3336 3337 static int 3338 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3339 { 3340 int error; 3341 int new_val; 3342 3343 new_val = num_cores; 3344 error = sysctl_handle_int(oidp, &new_val, 0, req); 3345 if (error != 0 || req->newptr == NULL) 3346 return (error); 3347 if (new_val > MAX_NUM_CORE_FILES) 3348 new_val = MAX_NUM_CORE_FILES; 3349 if (new_val < 0) 3350 new_val = 0; 3351 num_cores = new_val; 3352 return (0); 3353 } 3354 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3355 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3356 sysctl_debug_num_cores_check, "I", 3357 "Maximum number of generated process corefiles while using index format"); 3358 3359 #define GZIP_SUFFIX ".gz" 3360 #define ZSTD_SUFFIX ".zst" 3361 3362 int compress_user_cores = 0; 3363 3364 static int 3365 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3366 { 3367 int error, val; 3368 3369 val = compress_user_cores; 3370 error = sysctl_handle_int(oidp, &val, 0, req); 3371 if (error != 0 || req->newptr == NULL) 3372 return (error); 3373 if (val != 0 && !compressor_avail(val)) 3374 return (EINVAL); 3375 compress_user_cores = val; 3376 return (error); 3377 } 3378 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3379 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3380 sysctl_compress_user_cores, "I", 3381 "Enable compression of user corefiles (" 3382 __XSTRING(COMPRESS_GZIP) " = gzip, " 3383 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3384 3385 int compress_user_cores_level = 6; 3386 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3387 &compress_user_cores_level, 0, 3388 "Corefile compression level"); 3389 3390 /* 3391 * Protect the access to corefilename[] by allproc_lock. 3392 */ 3393 #define corefilename_lock allproc_lock 3394 3395 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3396 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3397 3398 static int 3399 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3400 { 3401 int error; 3402 3403 sx_xlock(&corefilename_lock); 3404 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3405 req); 3406 sx_xunlock(&corefilename_lock); 3407 3408 return (error); 3409 } 3410 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3411 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3412 "Process corefile name format string"); 3413 3414 static void 3415 vnode_close_locked(struct thread *td, struct vnode *vp) 3416 { 3417 3418 VOP_UNLOCK(vp); 3419 vn_close(vp, FWRITE, td->td_ucred, td); 3420 } 3421 3422 /* 3423 * If the core format has a %I in it, then we need to check 3424 * for existing corefiles before defining a name. 3425 * To do this we iterate over 0..ncores to find a 3426 * non-existing core file name to use. If all core files are 3427 * already used we choose the oldest one. 3428 */ 3429 static int 3430 corefile_open_last(struct thread *td, char *name, int indexpos, 3431 int indexlen, int ncores, struct vnode **vpp) 3432 { 3433 struct vnode *oldvp, *nextvp, *vp; 3434 struct vattr vattr; 3435 struct nameidata nd; 3436 int error, i, flags, oflags, cmode; 3437 char ch; 3438 struct timespec lasttime; 3439 3440 nextvp = oldvp = NULL; 3441 cmode = S_IRUSR | S_IWUSR; 3442 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3443 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3444 3445 for (i = 0; i < ncores; i++) { 3446 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3447 3448 ch = name[indexpos + indexlen]; 3449 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3450 i); 3451 name[indexpos + indexlen] = ch; 3452 3453 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3454 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3455 NULL); 3456 if (error != 0) 3457 break; 3458 3459 vp = nd.ni_vp; 3460 NDFREE(&nd, NDF_ONLY_PNBUF); 3461 if ((flags & O_CREAT) == O_CREAT) { 3462 nextvp = vp; 3463 break; 3464 } 3465 3466 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3467 if (error != 0) { 3468 vnode_close_locked(td, vp); 3469 break; 3470 } 3471 3472 if (oldvp == NULL || 3473 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3474 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3475 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3476 if (oldvp != NULL) 3477 vnode_close_locked(td, oldvp); 3478 oldvp = vp; 3479 lasttime = vattr.va_mtime; 3480 } else { 3481 vnode_close_locked(td, vp); 3482 } 3483 } 3484 3485 if (oldvp != NULL) { 3486 if (nextvp == NULL) { 3487 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3488 error = EFAULT; 3489 vnode_close_locked(td, oldvp); 3490 } else { 3491 nextvp = oldvp; 3492 } 3493 } else { 3494 vnode_close_locked(td, oldvp); 3495 } 3496 } 3497 if (error != 0) { 3498 if (nextvp != NULL) 3499 vnode_close_locked(td, oldvp); 3500 } else { 3501 *vpp = nextvp; 3502 } 3503 3504 return (error); 3505 } 3506 3507 /* 3508 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3509 * Expand the name described in corefilename, using name, uid, and pid 3510 * and open/create core file. 3511 * corefilename is a printf-like string, with three format specifiers: 3512 * %N name of process ("name") 3513 * %P process id (pid) 3514 * %U user id (uid) 3515 * For example, "%N.core" is the default; they can be disabled completely 3516 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3517 * This is controlled by the sysctl variable kern.corefile (see above). 3518 */ 3519 static int 3520 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3521 int compress, int signum, struct vnode **vpp, char **namep) 3522 { 3523 struct sbuf sb; 3524 struct nameidata nd; 3525 const char *format; 3526 char *hostname, *name; 3527 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3528 3529 hostname = NULL; 3530 format = corefilename; 3531 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3532 indexlen = 0; 3533 indexpos = -1; 3534 ncores = num_cores; 3535 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3536 sx_slock(&corefilename_lock); 3537 for (i = 0; format[i] != '\0'; i++) { 3538 switch (format[i]) { 3539 case '%': /* Format character */ 3540 i++; 3541 switch (format[i]) { 3542 case '%': 3543 sbuf_putc(&sb, '%'); 3544 break; 3545 case 'H': /* hostname */ 3546 if (hostname == NULL) { 3547 hostname = malloc(MAXHOSTNAMELEN, 3548 M_TEMP, M_WAITOK); 3549 } 3550 getcredhostname(td->td_ucred, hostname, 3551 MAXHOSTNAMELEN); 3552 sbuf_printf(&sb, "%s", hostname); 3553 break; 3554 case 'I': /* autoincrementing index */ 3555 if (indexpos != -1) { 3556 sbuf_printf(&sb, "%%I"); 3557 break; 3558 } 3559 3560 indexpos = sbuf_len(&sb); 3561 sbuf_printf(&sb, "%u", ncores - 1); 3562 indexlen = sbuf_len(&sb) - indexpos; 3563 break; 3564 case 'N': /* process name */ 3565 sbuf_printf(&sb, "%s", comm); 3566 break; 3567 case 'P': /* process id */ 3568 sbuf_printf(&sb, "%u", pid); 3569 break; 3570 case 'S': /* signal number */ 3571 sbuf_printf(&sb, "%i", signum); 3572 break; 3573 case 'U': /* user id */ 3574 sbuf_printf(&sb, "%u", uid); 3575 break; 3576 default: 3577 log(LOG_ERR, 3578 "Unknown format character %c in " 3579 "corename `%s'\n", format[i], format); 3580 break; 3581 } 3582 break; 3583 default: 3584 sbuf_putc(&sb, format[i]); 3585 break; 3586 } 3587 } 3588 sx_sunlock(&corefilename_lock); 3589 free(hostname, M_TEMP); 3590 if (compress == COMPRESS_GZIP) 3591 sbuf_printf(&sb, GZIP_SUFFIX); 3592 else if (compress == COMPRESS_ZSTD) 3593 sbuf_printf(&sb, ZSTD_SUFFIX); 3594 if (sbuf_error(&sb) != 0) { 3595 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3596 "long\n", (long)pid, comm, (u_long)uid); 3597 sbuf_delete(&sb); 3598 free(name, M_TEMP); 3599 return (ENOMEM); 3600 } 3601 sbuf_finish(&sb); 3602 sbuf_delete(&sb); 3603 3604 if (indexpos != -1) { 3605 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3606 vpp); 3607 if (error != 0) { 3608 log(LOG_ERR, 3609 "pid %d (%s), uid (%u): Path `%s' failed " 3610 "on initial open test, error = %d\n", 3611 pid, comm, uid, name, error); 3612 } 3613 } else { 3614 cmode = S_IRUSR | S_IWUSR; 3615 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3616 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3617 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3618 if ((td->td_proc->p_flag & P_SUGID) != 0) 3619 flags |= O_EXCL; 3620 3621 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3622 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3623 NULL); 3624 if (error == 0) { 3625 *vpp = nd.ni_vp; 3626 NDFREE(&nd, NDF_ONLY_PNBUF); 3627 } 3628 } 3629 3630 if (error != 0) { 3631 #ifdef AUDIT 3632 audit_proc_coredump(td, name, error); 3633 #endif 3634 free(name, M_TEMP); 3635 return (error); 3636 } 3637 *namep = name; 3638 return (0); 3639 } 3640 3641 /* 3642 * Dump a process' core. The main routine does some 3643 * policy checking, and creates the name of the coredump; 3644 * then it passes on a vnode and a size limit to the process-specific 3645 * coredump routine if there is one; if there _is not_ one, it returns 3646 * ENOSYS; otherwise it returns the error from the process-specific routine. 3647 */ 3648 3649 static int 3650 coredump(struct thread *td) 3651 { 3652 struct proc *p = td->td_proc; 3653 struct ucred *cred = td->td_ucred; 3654 struct vnode *vp; 3655 struct flock lf; 3656 struct vattr vattr; 3657 size_t fullpathsize; 3658 int error, error1, locked; 3659 char *name; /* name of corefile */ 3660 void *rl_cookie; 3661 off_t limit; 3662 char *fullpath, *freepath = NULL; 3663 struct sbuf *sb; 3664 3665 PROC_LOCK_ASSERT(p, MA_OWNED); 3666 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3667 _STOPEVENT(p, S_CORE, 0); 3668 3669 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3670 (p->p_flag2 & P2_NOTRACE) != 0) { 3671 PROC_UNLOCK(p); 3672 return (EFAULT); 3673 } 3674 3675 /* 3676 * Note that the bulk of limit checking is done after 3677 * the corefile is created. The exception is if the limit 3678 * for corefiles is 0, in which case we don't bother 3679 * creating the corefile at all. This layout means that 3680 * a corefile is truncated instead of not being created, 3681 * if it is larger than the limit. 3682 */ 3683 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3684 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3685 PROC_UNLOCK(p); 3686 return (EFBIG); 3687 } 3688 PROC_UNLOCK(p); 3689 3690 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3691 compress_user_cores, p->p_sig, &vp, &name); 3692 if (error != 0) 3693 return (error); 3694 3695 /* 3696 * Don't dump to non-regular files or files with links. 3697 * Do not dump into system files. Effective user must own the corefile. 3698 */ 3699 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3700 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3701 vattr.va_uid != cred->cr_uid) { 3702 VOP_UNLOCK(vp); 3703 error = EFAULT; 3704 goto out; 3705 } 3706 3707 VOP_UNLOCK(vp); 3708 3709 /* Postpone other writers, including core dumps of other processes. */ 3710 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3711 3712 lf.l_whence = SEEK_SET; 3713 lf.l_start = 0; 3714 lf.l_len = 0; 3715 lf.l_type = F_WRLCK; 3716 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3717 3718 VATTR_NULL(&vattr); 3719 vattr.va_size = 0; 3720 if (set_core_nodump_flag) 3721 vattr.va_flags = UF_NODUMP; 3722 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3723 VOP_SETATTR(vp, &vattr, cred); 3724 VOP_UNLOCK(vp); 3725 PROC_LOCK(p); 3726 p->p_acflag |= ACORE; 3727 PROC_UNLOCK(p); 3728 3729 if (p->p_sysent->sv_coredump != NULL) { 3730 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3731 } else { 3732 error = ENOSYS; 3733 } 3734 3735 if (locked) { 3736 lf.l_type = F_UNLCK; 3737 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3738 } 3739 vn_rangelock_unlock(vp, rl_cookie); 3740 3741 /* 3742 * Notify the userland helper that a process triggered a core dump. 3743 * This allows the helper to run an automated debugging session. 3744 */ 3745 if (error != 0 || coredump_devctl == 0) 3746 goto out; 3747 sb = sbuf_new_auto(); 3748 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3749 goto out2; 3750 sbuf_printf(sb, "comm=\""); 3751 devctl_safe_quote_sb(sb, fullpath); 3752 free(freepath, M_TEMP); 3753 sbuf_printf(sb, "\" core=\""); 3754 3755 /* 3756 * We can't lookup core file vp directly. When we're replacing a core, and 3757 * other random times, we flush the name cache, so it will fail. Instead, 3758 * if the path of the core is relative, add the current dir in front if it. 3759 */ 3760 if (name[0] != '/') { 3761 fullpathsize = MAXPATHLEN; 3762 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3763 if (vn_getcwd(td, freepath, &fullpath, &fullpathsize) != 0) { 3764 free(freepath, M_TEMP); 3765 goto out2; 3766 } 3767 devctl_safe_quote_sb(sb, fullpath); 3768 free(freepath, M_TEMP); 3769 sbuf_putc(sb, '/'); 3770 } 3771 devctl_safe_quote_sb(sb, name); 3772 sbuf_printf(sb, "\""); 3773 if (sbuf_finish(sb) == 0) 3774 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3775 out2: 3776 sbuf_delete(sb); 3777 out: 3778 error1 = vn_close(vp, FWRITE, cred, td); 3779 if (error == 0) 3780 error = error1; 3781 #ifdef AUDIT 3782 audit_proc_coredump(td, name, error); 3783 #endif 3784 free(name, M_TEMP); 3785 return (error); 3786 } 3787 3788 /* 3789 * Nonexistent system call-- signal process (may want to handle it). Flag 3790 * error in case process won't see signal immediately (blocked or ignored). 3791 */ 3792 #ifndef _SYS_SYSPROTO_H_ 3793 struct nosys_args { 3794 int dummy; 3795 }; 3796 #endif 3797 /* ARGSUSED */ 3798 int 3799 nosys(struct thread *td, struct nosys_args *args) 3800 { 3801 struct proc *p; 3802 3803 p = td->td_proc; 3804 3805 PROC_LOCK(p); 3806 tdsignal(td, SIGSYS); 3807 PROC_UNLOCK(p); 3808 if (kern_lognosys == 1 || kern_lognosys == 3) { 3809 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3810 td->td_sa.code); 3811 } 3812 if (kern_lognosys == 2 || kern_lognosys == 3) { 3813 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3814 td->td_sa.code); 3815 } 3816 return (ENOSYS); 3817 } 3818 3819 /* 3820 * Send a SIGIO or SIGURG signal to a process or process group using stored 3821 * credentials rather than those of the current process. 3822 */ 3823 void 3824 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3825 { 3826 ksiginfo_t ksi; 3827 struct sigio *sigio; 3828 3829 ksiginfo_init(&ksi); 3830 ksi.ksi_signo = sig; 3831 ksi.ksi_code = SI_KERNEL; 3832 3833 SIGIO_LOCK(); 3834 sigio = *sigiop; 3835 if (sigio == NULL) { 3836 SIGIO_UNLOCK(); 3837 return; 3838 } 3839 if (sigio->sio_pgid > 0) { 3840 PROC_LOCK(sigio->sio_proc); 3841 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3842 kern_psignal(sigio->sio_proc, sig); 3843 PROC_UNLOCK(sigio->sio_proc); 3844 } else if (sigio->sio_pgid < 0) { 3845 struct proc *p; 3846 3847 PGRP_LOCK(sigio->sio_pgrp); 3848 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3849 PROC_LOCK(p); 3850 if (p->p_state == PRS_NORMAL && 3851 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3852 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3853 kern_psignal(p, sig); 3854 PROC_UNLOCK(p); 3855 } 3856 PGRP_UNLOCK(sigio->sio_pgrp); 3857 } 3858 SIGIO_UNLOCK(); 3859 } 3860 3861 static int 3862 filt_sigattach(struct knote *kn) 3863 { 3864 struct proc *p = curproc; 3865 3866 kn->kn_ptr.p_proc = p; 3867 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3868 3869 knlist_add(p->p_klist, kn, 0); 3870 3871 return (0); 3872 } 3873 3874 static void 3875 filt_sigdetach(struct knote *kn) 3876 { 3877 struct proc *p = kn->kn_ptr.p_proc; 3878 3879 knlist_remove(p->p_klist, kn, 0); 3880 } 3881 3882 /* 3883 * signal knotes are shared with proc knotes, so we apply a mask to 3884 * the hint in order to differentiate them from process hints. This 3885 * could be avoided by using a signal-specific knote list, but probably 3886 * isn't worth the trouble. 3887 */ 3888 static int 3889 filt_signal(struct knote *kn, long hint) 3890 { 3891 3892 if (hint & NOTE_SIGNAL) { 3893 hint &= ~NOTE_SIGNAL; 3894 3895 if (kn->kn_id == hint) 3896 kn->kn_data++; 3897 } 3898 return (kn->kn_data != 0); 3899 } 3900 3901 struct sigacts * 3902 sigacts_alloc(void) 3903 { 3904 struct sigacts *ps; 3905 3906 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3907 refcount_init(&ps->ps_refcnt, 1); 3908 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3909 return (ps); 3910 } 3911 3912 void 3913 sigacts_free(struct sigacts *ps) 3914 { 3915 3916 if (refcount_release(&ps->ps_refcnt) == 0) 3917 return; 3918 mtx_destroy(&ps->ps_mtx); 3919 free(ps, M_SUBPROC); 3920 } 3921 3922 struct sigacts * 3923 sigacts_hold(struct sigacts *ps) 3924 { 3925 3926 refcount_acquire(&ps->ps_refcnt); 3927 return (ps); 3928 } 3929 3930 void 3931 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3932 { 3933 3934 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3935 mtx_lock(&src->ps_mtx); 3936 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3937 mtx_unlock(&src->ps_mtx); 3938 } 3939 3940 int 3941 sigacts_shared(struct sigacts *ps) 3942 { 3943 3944 return (ps->ps_refcnt > 1); 3945 } 3946 3947 void 3948 sig_drop_caught(struct proc *p) 3949 { 3950 int sig; 3951 struct sigacts *ps; 3952 3953 ps = p->p_sigacts; 3954 PROC_LOCK_ASSERT(p, MA_OWNED); 3955 mtx_assert(&ps->ps_mtx, MA_OWNED); 3956 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3957 sig = sig_ffs(&ps->ps_sigcatch); 3958 sigdflt(ps, sig); 3959 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 3960 sigqueue_delete_proc(p, sig); 3961 } 3962 } 3963 3964 static void 3965 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 3966 { 3967 ksiginfo_t ksi; 3968 3969 /* 3970 * Prevent further fetches and SIGSEGVs, allowing thread to 3971 * issue syscalls despite corruption. 3972 */ 3973 sigfastblock_clear(td); 3974 3975 if (!sendsig) 3976 return; 3977 ksiginfo_init_trap(&ksi); 3978 ksi.ksi_signo = SIGSEGV; 3979 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 3980 ksi.ksi_addr = td->td_sigblock_ptr; 3981 trapsignal(td, &ksi); 3982 } 3983 3984 static bool 3985 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 3986 { 3987 uint32_t res; 3988 3989 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 3990 return (true); 3991 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 3992 sigfastblock_failed(td, sendsig, false); 3993 return (false); 3994 } 3995 *valp = res; 3996 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 3997 return (true); 3998 } 3999 4000 int 4001 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4002 { 4003 struct proc *p; 4004 int error, res; 4005 uint32_t oldval; 4006 4007 error = 0; 4008 p = td->td_proc; 4009 switch (uap->cmd) { 4010 case SIGFASTBLOCK_SETPTR: 4011 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4012 error = EBUSY; 4013 break; 4014 } 4015 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4016 error = EINVAL; 4017 break; 4018 } 4019 td->td_pflags |= TDP_SIGFASTBLOCK; 4020 td->td_sigblock_ptr = uap->ptr; 4021 break; 4022 4023 case SIGFASTBLOCK_UNBLOCK: 4024 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4025 error = EINVAL; 4026 break; 4027 } 4028 4029 for (;;) { 4030 res = casueword32(td->td_sigblock_ptr, 4031 SIGFASTBLOCK_PEND, &oldval, 0); 4032 if (res == -1) { 4033 error = EFAULT; 4034 sigfastblock_failed(td, false, true); 4035 break; 4036 } 4037 if (res == 0) 4038 break; 4039 MPASS(res == 1); 4040 if (oldval != SIGFASTBLOCK_PEND) { 4041 error = EBUSY; 4042 break; 4043 } 4044 error = thread_check_susp(td, false); 4045 if (error != 0) 4046 break; 4047 } 4048 if (error != 0) 4049 break; 4050 4051 /* 4052 * td_sigblock_val is cleared there, but not on a 4053 * syscall exit. The end effect is that a single 4054 * interruptible sleep, while user sigblock word is 4055 * set, might return EINTR or ERESTART to usermode 4056 * without delivering signal. All further sleeps, 4057 * until userspace clears the word and does 4058 * sigfastblock(UNBLOCK), observe current word and no 4059 * longer get interrupted. It is slight 4060 * non-conformance, with alternative to have read the 4061 * sigblock word on each syscall entry. 4062 */ 4063 td->td_sigblock_val = 0; 4064 4065 /* 4066 * Rely on normal ast mechanism to deliver pending 4067 * signals to current thread. But notify others about 4068 * fake unblock. 4069 */ 4070 if (error == 0 && p->p_numthreads != 1) { 4071 PROC_LOCK(p); 4072 reschedule_signals(p, td->td_sigmask, 0); 4073 PROC_UNLOCK(p); 4074 } 4075 break; 4076 4077 case SIGFASTBLOCK_UNSETPTR: 4078 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4079 error = EINVAL; 4080 break; 4081 } 4082 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4083 error = EFAULT; 4084 break; 4085 } 4086 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4087 error = EBUSY; 4088 break; 4089 } 4090 sigfastblock_clear(td); 4091 break; 4092 4093 default: 4094 error = EINVAL; 4095 break; 4096 } 4097 return (error); 4098 } 4099 4100 void 4101 sigfastblock_clear(struct thread *td) 4102 { 4103 struct proc *p; 4104 bool resched; 4105 4106 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4107 return; 4108 td->td_sigblock_val = 0; 4109 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0; 4110 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4111 if (resched) { 4112 p = td->td_proc; 4113 PROC_LOCK(p); 4114 reschedule_signals(p, td->td_sigmask, 0); 4115 PROC_UNLOCK(p); 4116 } 4117 } 4118 4119 void 4120 sigfastblock_fetch(struct thread *td) 4121 { 4122 uint32_t val; 4123 4124 (void)sigfastblock_fetch_sig(td, true, &val); 4125 } 4126 4127 void 4128 sigfastblock_setpend(struct thread *td) 4129 { 4130 int res; 4131 uint32_t oldval; 4132 4133 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4134 return; 4135 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4136 if (res == -1) { 4137 sigfastblock_failed(td, true, false); 4138 return; 4139 } 4140 for (;;) { 4141 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4142 oldval | SIGFASTBLOCK_PEND); 4143 if (res == -1) { 4144 sigfastblock_failed(td, true, true); 4145 return; 4146 } 4147 if (res == 0) { 4148 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4149 td->td_pflags &= ~TDP_SIGFASTPENDING; 4150 break; 4151 } 4152 MPASS(res == 1); 4153 if (thread_check_susp(td, false) != 0) 4154 break; 4155 } 4156 } 4157