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/capsicum.h> 51 #include <sys/compressor.h> 52 #include <sys/condvar.h> 53 #include <sys/devctl.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/racct.h> 71 #include <sys/resourcevar.h> 72 #include <sys/sdt.h> 73 #include <sys/sbuf.h> 74 #include <sys/sleepqueue.h> 75 #include <sys/smp.h> 76 #include <sys/stat.h> 77 #include <sys/sx.h> 78 #include <sys/syscallsubr.h> 79 #include <sys/sysctl.h> 80 #include <sys/sysent.h> 81 #include <sys/syslog.h> 82 #include <sys/sysproto.h> 83 #include <sys/timers.h> 84 #include <sys/unistd.h> 85 #include <sys/wait.h> 86 #include <vm/vm.h> 87 #include <vm/vm_extern.h> 88 #include <vm/uma.h> 89 90 #include <sys/jail.h> 91 92 #include <machine/cpu.h> 93 94 #include <security/audit/audit.h> 95 96 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98 SDT_PROVIDER_DECLARE(proc); 99 SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101 SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103 SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106 static int coredump(struct thread *); 107 static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109 static int issignal(struct thread *td); 110 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 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 /* Ensure the sigfastblock value is up to date. */ 1272 sigfastblock_fetch(td); 1273 1274 if (timeout != NULL) { 1275 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1276 timevalid = 1; 1277 getnanouptime(&rts); 1278 timespecadd(&rts, timeout, &ets); 1279 } 1280 } 1281 ksiginfo_init(ksi); 1282 /* Some signals can not be waited for. */ 1283 SIG_CANTMASK(waitset); 1284 ps = p->p_sigacts; 1285 PROC_LOCK(p); 1286 saved_mask = td->td_sigmask; 1287 SIGSETNAND(td->td_sigmask, waitset); 1288 for (;;) { 1289 mtx_lock(&ps->ps_mtx); 1290 sig = cursig(td); 1291 mtx_unlock(&ps->ps_mtx); 1292 KASSERT(sig >= 0, ("sig %d", sig)); 1293 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1294 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1295 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1296 error = 0; 1297 break; 1298 } 1299 } 1300 1301 if (error != 0) 1302 break; 1303 1304 /* 1305 * POSIX says this must be checked after looking for pending 1306 * signals. 1307 */ 1308 if (timeout != NULL) { 1309 if (!timevalid) { 1310 error = EINVAL; 1311 break; 1312 } 1313 getnanouptime(&rts); 1314 if (timespeccmp(&rts, &ets, >=)) { 1315 error = EAGAIN; 1316 break; 1317 } 1318 timespecsub(&ets, &rts, &ts); 1319 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1320 timo = tvtohz(&tv); 1321 } else { 1322 timo = 0; 1323 } 1324 1325 if (traced) { 1326 error = EINTR; 1327 break; 1328 } 1329 1330 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1331 1332 if (timeout != NULL) { 1333 if (error == ERESTART) { 1334 /* Timeout can not be restarted. */ 1335 error = EINTR; 1336 } else if (error == EAGAIN) { 1337 /* We will calculate timeout by ourself. */ 1338 error = 0; 1339 } 1340 } 1341 1342 /* 1343 * If PTRACE_SCE or PTRACE_SCX were set after 1344 * userspace entered the syscall, return spurious 1345 * EINTR after wait was done. Only do this as last 1346 * resort after rechecking for possible queued signals 1347 * and expired timeouts. 1348 */ 1349 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1350 traced = true; 1351 } 1352 1353 new_block = saved_mask; 1354 SIGSETNAND(new_block, td->td_sigmask); 1355 td->td_sigmask = saved_mask; 1356 /* 1357 * Fewer signals can be delivered to us, reschedule signal 1358 * notification. 1359 */ 1360 if (p->p_numthreads != 1) 1361 reschedule_signals(p, new_block, 0); 1362 1363 if (error == 0) { 1364 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1365 1366 if (ksi->ksi_code == SI_TIMER) 1367 itimer_accept(p, ksi->ksi_timerid, ksi); 1368 1369 #ifdef KTRACE 1370 if (KTRPOINT(td, KTR_PSIG)) { 1371 sig_t action; 1372 1373 mtx_lock(&ps->ps_mtx); 1374 action = ps->ps_sigact[_SIG_IDX(sig)]; 1375 mtx_unlock(&ps->ps_mtx); 1376 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1377 } 1378 #endif 1379 if (sig == SIGKILL) { 1380 proc_td_siginfo_capture(td, &ksi->ksi_info); 1381 sigexit(td, sig); 1382 } 1383 } 1384 PROC_UNLOCK(p); 1385 return (error); 1386 } 1387 1388 #ifndef _SYS_SYSPROTO_H_ 1389 struct sigpending_args { 1390 sigset_t *set; 1391 }; 1392 #endif 1393 int 1394 sys_sigpending(struct thread *td, struct sigpending_args *uap) 1395 { 1396 struct proc *p = td->td_proc; 1397 sigset_t pending; 1398 1399 PROC_LOCK(p); 1400 pending = p->p_sigqueue.sq_signals; 1401 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1402 PROC_UNLOCK(p); 1403 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1404 } 1405 1406 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1407 #ifndef _SYS_SYSPROTO_H_ 1408 struct osigpending_args { 1409 int dummy; 1410 }; 1411 #endif 1412 int 1413 osigpending(struct thread *td, struct osigpending_args *uap) 1414 { 1415 struct proc *p = td->td_proc; 1416 sigset_t pending; 1417 1418 PROC_LOCK(p); 1419 pending = p->p_sigqueue.sq_signals; 1420 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1421 PROC_UNLOCK(p); 1422 SIG2OSIG(pending, td->td_retval[0]); 1423 return (0); 1424 } 1425 #endif /* COMPAT_43 */ 1426 1427 #if defined(COMPAT_43) 1428 /* 1429 * Generalized interface signal handler, 4.3-compatible. 1430 */ 1431 #ifndef _SYS_SYSPROTO_H_ 1432 struct osigvec_args { 1433 int signum; 1434 struct sigvec *nsv; 1435 struct sigvec *osv; 1436 }; 1437 #endif 1438 /* ARGSUSED */ 1439 int 1440 osigvec(struct thread *td, struct osigvec_args *uap) 1441 { 1442 struct sigvec vec; 1443 struct sigaction nsa, osa; 1444 struct sigaction *nsap, *osap; 1445 int error; 1446 1447 if (uap->signum <= 0 || uap->signum >= ONSIG) 1448 return (EINVAL); 1449 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1450 osap = (uap->osv != NULL) ? &osa : NULL; 1451 if (nsap) { 1452 error = copyin(uap->nsv, &vec, sizeof(vec)); 1453 if (error) 1454 return (error); 1455 nsap->sa_handler = vec.sv_handler; 1456 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1457 nsap->sa_flags = vec.sv_flags; 1458 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1459 } 1460 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1461 if (osap && !error) { 1462 vec.sv_handler = osap->sa_handler; 1463 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1464 vec.sv_flags = osap->sa_flags; 1465 vec.sv_flags &= ~SA_NOCLDWAIT; 1466 vec.sv_flags ^= SA_RESTART; 1467 error = copyout(&vec, uap->osv, sizeof(vec)); 1468 } 1469 return (error); 1470 } 1471 1472 #ifndef _SYS_SYSPROTO_H_ 1473 struct osigblock_args { 1474 int mask; 1475 }; 1476 #endif 1477 int 1478 osigblock(struct thread *td, struct osigblock_args *uap) 1479 { 1480 sigset_t set, oset; 1481 1482 OSIG2SIG(uap->mask, set); 1483 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1484 SIG2OSIG(oset, td->td_retval[0]); 1485 return (0); 1486 } 1487 1488 #ifndef _SYS_SYSPROTO_H_ 1489 struct osigsetmask_args { 1490 int mask; 1491 }; 1492 #endif 1493 int 1494 osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1495 { 1496 sigset_t set, oset; 1497 1498 OSIG2SIG(uap->mask, set); 1499 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1500 SIG2OSIG(oset, td->td_retval[0]); 1501 return (0); 1502 } 1503 #endif /* COMPAT_43 */ 1504 1505 /* 1506 * Suspend calling thread until signal, providing mask to be set in the 1507 * meantime. 1508 */ 1509 #ifndef _SYS_SYSPROTO_H_ 1510 struct sigsuspend_args { 1511 const sigset_t *sigmask; 1512 }; 1513 #endif 1514 /* ARGSUSED */ 1515 int 1516 sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1517 { 1518 sigset_t mask; 1519 int error; 1520 1521 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1522 if (error) 1523 return (error); 1524 return (kern_sigsuspend(td, mask)); 1525 } 1526 1527 int 1528 kern_sigsuspend(struct thread *td, sigset_t mask) 1529 { 1530 struct proc *p = td->td_proc; 1531 int has_sig, sig; 1532 1533 /* Ensure the sigfastblock value is up to date. */ 1534 sigfastblock_fetch(td); 1535 1536 /* 1537 * When returning from sigsuspend, we want 1538 * the old mask to be restored after the 1539 * signal handler has finished. Thus, we 1540 * save it here and mark the sigacts structure 1541 * to indicate this. 1542 */ 1543 PROC_LOCK(p); 1544 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1545 SIGPROCMASK_PROC_LOCKED); 1546 td->td_pflags |= TDP_OLDMASK; 1547 1548 /* 1549 * Process signals now. Otherwise, we can get spurious wakeup 1550 * due to signal entered process queue, but delivered to other 1551 * thread. But sigsuspend should return only on signal 1552 * delivery. 1553 */ 1554 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1555 for (has_sig = 0; !has_sig;) { 1556 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1557 0) == 0) 1558 /* void */; 1559 thread_suspend_check(0); 1560 mtx_lock(&p->p_sigacts->ps_mtx); 1561 while ((sig = cursig(td)) != 0) { 1562 KASSERT(sig >= 0, ("sig %d", sig)); 1563 has_sig += postsig(sig); 1564 } 1565 mtx_unlock(&p->p_sigacts->ps_mtx); 1566 1567 /* 1568 * If PTRACE_SCE or PTRACE_SCX were set after 1569 * userspace entered the syscall, return spurious 1570 * EINTR. 1571 */ 1572 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1573 has_sig += 1; 1574 } 1575 PROC_UNLOCK(p); 1576 td->td_errno = EINTR; 1577 td->td_pflags |= TDP_NERRNO; 1578 return (EJUSTRETURN); 1579 } 1580 1581 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1582 /* 1583 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1584 * convention: libc stub passes mask, not pointer, to save a copyin. 1585 */ 1586 #ifndef _SYS_SYSPROTO_H_ 1587 struct osigsuspend_args { 1588 osigset_t mask; 1589 }; 1590 #endif 1591 /* ARGSUSED */ 1592 int 1593 osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1594 { 1595 sigset_t mask; 1596 1597 OSIG2SIG(uap->mask, mask); 1598 return (kern_sigsuspend(td, mask)); 1599 } 1600 #endif /* COMPAT_43 */ 1601 1602 #if defined(COMPAT_43) 1603 #ifndef _SYS_SYSPROTO_H_ 1604 struct osigstack_args { 1605 struct sigstack *nss; 1606 struct sigstack *oss; 1607 }; 1608 #endif 1609 /* ARGSUSED */ 1610 int 1611 osigstack(struct thread *td, struct osigstack_args *uap) 1612 { 1613 struct sigstack nss, oss; 1614 int error = 0; 1615 1616 if (uap->nss != NULL) { 1617 error = copyin(uap->nss, &nss, sizeof(nss)); 1618 if (error) 1619 return (error); 1620 } 1621 oss.ss_sp = td->td_sigstk.ss_sp; 1622 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1623 if (uap->nss != NULL) { 1624 td->td_sigstk.ss_sp = nss.ss_sp; 1625 td->td_sigstk.ss_size = 0; 1626 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1627 td->td_pflags |= TDP_ALTSTACK; 1628 } 1629 if (uap->oss != NULL) 1630 error = copyout(&oss, uap->oss, sizeof(oss)); 1631 1632 return (error); 1633 } 1634 #endif /* COMPAT_43 */ 1635 1636 #ifndef _SYS_SYSPROTO_H_ 1637 struct sigaltstack_args { 1638 stack_t *ss; 1639 stack_t *oss; 1640 }; 1641 #endif 1642 /* ARGSUSED */ 1643 int 1644 sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1645 { 1646 stack_t ss, oss; 1647 int error; 1648 1649 if (uap->ss != NULL) { 1650 error = copyin(uap->ss, &ss, sizeof(ss)); 1651 if (error) 1652 return (error); 1653 } 1654 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1655 (uap->oss != NULL) ? &oss : NULL); 1656 if (error) 1657 return (error); 1658 if (uap->oss != NULL) 1659 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1660 return (error); 1661 } 1662 1663 int 1664 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1665 { 1666 struct proc *p = td->td_proc; 1667 int oonstack; 1668 1669 oonstack = sigonstack(cpu_getstack(td)); 1670 1671 if (oss != NULL) { 1672 *oss = td->td_sigstk; 1673 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1674 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1675 } 1676 1677 if (ss != NULL) { 1678 if (oonstack) 1679 return (EPERM); 1680 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1681 return (EINVAL); 1682 if (!(ss->ss_flags & SS_DISABLE)) { 1683 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1684 return (ENOMEM); 1685 1686 td->td_sigstk = *ss; 1687 td->td_pflags |= TDP_ALTSTACK; 1688 } else { 1689 td->td_pflags &= ~TDP_ALTSTACK; 1690 } 1691 } 1692 return (0); 1693 } 1694 1695 struct killpg1_ctx { 1696 struct thread *td; 1697 ksiginfo_t *ksi; 1698 int sig; 1699 bool sent; 1700 bool found; 1701 int ret; 1702 }; 1703 1704 static void 1705 killpg1_sendsig(struct proc *p, bool notself, struct killpg1_ctx *arg) 1706 { 1707 int err; 1708 1709 if (p->p_pid <= 1 || (p->p_flag & P_SYSTEM) != 0 || 1710 (notself && p == arg->td->td_proc) || p->p_state == PRS_NEW) 1711 return; 1712 PROC_LOCK(p); 1713 err = p_cansignal(arg->td, p, arg->sig); 1714 if (err == 0 && arg->sig != 0) 1715 pksignal(p, arg->sig, arg->ksi); 1716 PROC_UNLOCK(p); 1717 if (err != ESRCH) 1718 arg->found = true; 1719 if (err == 0) 1720 arg->sent = true; 1721 else if (arg->ret == 0 && err != ESRCH && err != EPERM) 1722 arg->ret = err; 1723 } 1724 1725 /* 1726 * Common code for kill process group/broadcast kill. 1727 * cp is calling process. 1728 */ 1729 static int 1730 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1731 { 1732 struct proc *p; 1733 struct pgrp *pgrp; 1734 struct killpg1_ctx arg; 1735 1736 arg.td = td; 1737 arg.ksi = ksi; 1738 arg.sig = sig; 1739 arg.sent = false; 1740 arg.found = false; 1741 arg.ret = 0; 1742 if (all) { 1743 /* 1744 * broadcast 1745 */ 1746 sx_slock(&allproc_lock); 1747 FOREACH_PROC_IN_SYSTEM(p) { 1748 killpg1_sendsig(p, true, &arg); 1749 } 1750 sx_sunlock(&allproc_lock); 1751 } else { 1752 sx_slock(&proctree_lock); 1753 if (pgid == 0) { 1754 /* 1755 * zero pgid means send to my process group. 1756 */ 1757 pgrp = td->td_proc->p_pgrp; 1758 PGRP_LOCK(pgrp); 1759 } else { 1760 pgrp = pgfind(pgid); 1761 if (pgrp == NULL) { 1762 sx_sunlock(&proctree_lock); 1763 return (ESRCH); 1764 } 1765 } 1766 sx_sunlock(&proctree_lock); 1767 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1768 killpg1_sendsig(p, false, &arg); 1769 } 1770 PGRP_UNLOCK(pgrp); 1771 } 1772 MPASS(arg.ret != 0 || arg.found || !arg.sent); 1773 if (arg.ret == 0 && !arg.sent) 1774 arg.ret = arg.found ? EPERM : ESRCH; 1775 return (arg.ret); 1776 } 1777 1778 #ifndef _SYS_SYSPROTO_H_ 1779 struct kill_args { 1780 int pid; 1781 int signum; 1782 }; 1783 #endif 1784 /* ARGSUSED */ 1785 int 1786 sys_kill(struct thread *td, struct kill_args *uap) 1787 { 1788 1789 return (kern_kill(td, uap->pid, uap->signum)); 1790 } 1791 1792 int 1793 kern_kill(struct thread *td, pid_t pid, int signum) 1794 { 1795 ksiginfo_t ksi; 1796 struct proc *p; 1797 int error; 1798 1799 /* 1800 * A process in capability mode can send signals only to himself. 1801 * The main rationale behind this is that abort(3) is implemented as 1802 * kill(getpid(), SIGABRT). 1803 */ 1804 if (IN_CAPABILITY_MODE(td) && pid != td->td_proc->p_pid) 1805 return (ECAPMODE); 1806 1807 AUDIT_ARG_SIGNUM(signum); 1808 AUDIT_ARG_PID(pid); 1809 if ((u_int)signum > _SIG_MAXSIG) 1810 return (EINVAL); 1811 1812 ksiginfo_init(&ksi); 1813 ksi.ksi_signo = signum; 1814 ksi.ksi_code = SI_USER; 1815 ksi.ksi_pid = td->td_proc->p_pid; 1816 ksi.ksi_uid = td->td_ucred->cr_ruid; 1817 1818 if (pid > 0) { 1819 /* kill single process */ 1820 if ((p = pfind_any(pid)) == NULL) 1821 return (ESRCH); 1822 AUDIT_ARG_PROCESS(p); 1823 error = p_cansignal(td, p, signum); 1824 if (error == 0 && signum) 1825 pksignal(p, signum, &ksi); 1826 PROC_UNLOCK(p); 1827 return (error); 1828 } 1829 switch (pid) { 1830 case -1: /* broadcast signal */ 1831 return (killpg1(td, signum, 0, 1, &ksi)); 1832 case 0: /* signal own process group */ 1833 return (killpg1(td, signum, 0, 0, &ksi)); 1834 default: /* negative explicit process group */ 1835 return (killpg1(td, signum, -pid, 0, &ksi)); 1836 } 1837 /* NOTREACHED */ 1838 } 1839 1840 int 1841 sys_pdkill(struct thread *td, struct pdkill_args *uap) 1842 { 1843 struct proc *p; 1844 int error; 1845 1846 AUDIT_ARG_SIGNUM(uap->signum); 1847 AUDIT_ARG_FD(uap->fd); 1848 if ((u_int)uap->signum > _SIG_MAXSIG) 1849 return (EINVAL); 1850 1851 error = procdesc_find(td, uap->fd, &cap_pdkill_rights, &p); 1852 if (error) 1853 return (error); 1854 AUDIT_ARG_PROCESS(p); 1855 error = p_cansignal(td, p, uap->signum); 1856 if (error == 0 && uap->signum) 1857 kern_psignal(p, uap->signum); 1858 PROC_UNLOCK(p); 1859 return (error); 1860 } 1861 1862 #if defined(COMPAT_43) 1863 #ifndef _SYS_SYSPROTO_H_ 1864 struct okillpg_args { 1865 int pgid; 1866 int signum; 1867 }; 1868 #endif 1869 /* ARGSUSED */ 1870 int 1871 okillpg(struct thread *td, struct okillpg_args *uap) 1872 { 1873 ksiginfo_t ksi; 1874 1875 AUDIT_ARG_SIGNUM(uap->signum); 1876 AUDIT_ARG_PID(uap->pgid); 1877 if ((u_int)uap->signum > _SIG_MAXSIG) 1878 return (EINVAL); 1879 1880 ksiginfo_init(&ksi); 1881 ksi.ksi_signo = uap->signum; 1882 ksi.ksi_code = SI_USER; 1883 ksi.ksi_pid = td->td_proc->p_pid; 1884 ksi.ksi_uid = td->td_ucred->cr_ruid; 1885 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1886 } 1887 #endif /* COMPAT_43 */ 1888 1889 #ifndef _SYS_SYSPROTO_H_ 1890 struct sigqueue_args { 1891 pid_t pid; 1892 int signum; 1893 /* union sigval */ void *value; 1894 }; 1895 #endif 1896 int 1897 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1898 { 1899 union sigval sv; 1900 1901 sv.sival_ptr = uap->value; 1902 1903 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1904 } 1905 1906 int 1907 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1908 { 1909 ksiginfo_t ksi; 1910 struct proc *p; 1911 int error; 1912 1913 if ((u_int)signum > _SIG_MAXSIG) 1914 return (EINVAL); 1915 1916 /* 1917 * Specification says sigqueue can only send signal to 1918 * single process. 1919 */ 1920 if (pid <= 0) 1921 return (EINVAL); 1922 1923 if ((p = pfind_any(pid)) == NULL) 1924 return (ESRCH); 1925 error = p_cansignal(td, p, signum); 1926 if (error == 0 && signum != 0) { 1927 ksiginfo_init(&ksi); 1928 ksi.ksi_flags = KSI_SIGQ; 1929 ksi.ksi_signo = signum; 1930 ksi.ksi_code = SI_QUEUE; 1931 ksi.ksi_pid = td->td_proc->p_pid; 1932 ksi.ksi_uid = td->td_ucred->cr_ruid; 1933 ksi.ksi_value = *value; 1934 error = pksignal(p, ksi.ksi_signo, &ksi); 1935 } 1936 PROC_UNLOCK(p); 1937 return (error); 1938 } 1939 1940 /* 1941 * Send a signal to a process group. 1942 */ 1943 void 1944 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1945 { 1946 struct pgrp *pgrp; 1947 1948 if (pgid != 0) { 1949 sx_slock(&proctree_lock); 1950 pgrp = pgfind(pgid); 1951 sx_sunlock(&proctree_lock); 1952 if (pgrp != NULL) { 1953 pgsignal(pgrp, sig, 0, ksi); 1954 PGRP_UNLOCK(pgrp); 1955 } 1956 } 1957 } 1958 1959 /* 1960 * Send a signal to a process group. If checktty is 1, 1961 * limit to members which have a controlling terminal. 1962 */ 1963 void 1964 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1965 { 1966 struct proc *p; 1967 1968 if (pgrp) { 1969 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1970 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1971 PROC_LOCK(p); 1972 if (p->p_state == PRS_NORMAL && 1973 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1974 pksignal(p, sig, ksi); 1975 PROC_UNLOCK(p); 1976 } 1977 } 1978 } 1979 1980 /* 1981 * Recalculate the signal mask and reset the signal disposition after 1982 * usermode frame for delivery is formed. Should be called after 1983 * mach-specific routine, because sysent->sv_sendsig() needs correct 1984 * ps_siginfo and signal mask. 1985 */ 1986 static void 1987 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1988 { 1989 sigset_t mask; 1990 1991 mtx_assert(&ps->ps_mtx, MA_OWNED); 1992 td->td_ru.ru_nsignals++; 1993 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1994 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1995 SIGADDSET(mask, sig); 1996 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1997 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1998 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1999 sigdflt(ps, sig); 2000 } 2001 2002 /* 2003 * Send a signal caused by a trap to the current thread. If it will be 2004 * caught immediately, deliver it with correct code. Otherwise, post it 2005 * normally. 2006 */ 2007 void 2008 trapsignal(struct thread *td, ksiginfo_t *ksi) 2009 { 2010 struct sigacts *ps; 2011 struct proc *p; 2012 sigset_t sigmask; 2013 int code, sig; 2014 2015 p = td->td_proc; 2016 sig = ksi->ksi_signo; 2017 code = ksi->ksi_code; 2018 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2019 2020 sigfastblock_fetch(td); 2021 PROC_LOCK(p); 2022 ps = p->p_sigacts; 2023 mtx_lock(&ps->ps_mtx); 2024 sigmask = td->td_sigmask; 2025 if (td->td_sigblock_val != 0) 2026 SIGSETOR(sigmask, fastblock_mask); 2027 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2028 !SIGISMEMBER(sigmask, sig)) { 2029 #ifdef KTRACE 2030 if (KTRPOINT(curthread, KTR_PSIG)) 2031 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2032 &td->td_sigmask, code); 2033 #endif 2034 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2035 ksi, &td->td_sigmask); 2036 postsig_done(sig, td, ps); 2037 mtx_unlock(&ps->ps_mtx); 2038 } else { 2039 /* 2040 * Avoid a possible infinite loop if the thread 2041 * masking the signal or process is ignoring the 2042 * signal. 2043 */ 2044 if (kern_forcesigexit && (SIGISMEMBER(sigmask, sig) || 2045 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2046 SIGDELSET(td->td_sigmask, sig); 2047 SIGDELSET(ps->ps_sigcatch, sig); 2048 SIGDELSET(ps->ps_sigignore, sig); 2049 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2050 td->td_pflags &= ~TDP_SIGFASTBLOCK; 2051 td->td_sigblock_val = 0; 2052 } 2053 mtx_unlock(&ps->ps_mtx); 2054 p->p_sig = sig; /* XXX to verify code */ 2055 tdsendsignal(p, td, sig, ksi); 2056 } 2057 PROC_UNLOCK(p); 2058 } 2059 2060 static struct thread * 2061 sigtd(struct proc *p, int sig, bool fast_sigblock) 2062 { 2063 struct thread *td, *signal_td; 2064 2065 PROC_LOCK_ASSERT(p, MA_OWNED); 2066 MPASS(!fast_sigblock || p == curproc); 2067 2068 /* 2069 * Check if current thread can handle the signal without 2070 * switching context to another thread. 2071 */ 2072 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig) && 2073 (!fast_sigblock || curthread->td_sigblock_val == 0)) 2074 return (curthread); 2075 signal_td = NULL; 2076 FOREACH_THREAD_IN_PROC(p, td) { 2077 if (!SIGISMEMBER(td->td_sigmask, sig) && (!fast_sigblock || 2078 td != curthread || td->td_sigblock_val == 0)) { 2079 signal_td = td; 2080 break; 2081 } 2082 } 2083 if (signal_td == NULL) 2084 signal_td = FIRST_THREAD_IN_PROC(p); 2085 return (signal_td); 2086 } 2087 2088 /* 2089 * Send the signal to the process. If the signal has an action, the action 2090 * is usually performed by the target process rather than the caller; we add 2091 * the signal to the set of pending signals for the process. 2092 * 2093 * Exceptions: 2094 * o When a stop signal is sent to a sleeping process that takes the 2095 * default action, the process is stopped without awakening it. 2096 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2097 * regardless of the signal action (eg, blocked or ignored). 2098 * 2099 * Other ignored signals are discarded immediately. 2100 * 2101 * NB: This function may be entered from the debugger via the "kill" DDB 2102 * command. There is little that can be done to mitigate the possibly messy 2103 * side effects of this unwise possibility. 2104 */ 2105 void 2106 kern_psignal(struct proc *p, int sig) 2107 { 2108 ksiginfo_t ksi; 2109 2110 ksiginfo_init(&ksi); 2111 ksi.ksi_signo = sig; 2112 ksi.ksi_code = SI_KERNEL; 2113 (void) tdsendsignal(p, NULL, sig, &ksi); 2114 } 2115 2116 int 2117 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2118 { 2119 2120 return (tdsendsignal(p, NULL, sig, ksi)); 2121 } 2122 2123 /* Utility function for finding a thread to send signal event to. */ 2124 int 2125 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2126 { 2127 struct thread *td; 2128 2129 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2130 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2131 if (td == NULL) 2132 return (ESRCH); 2133 *ttd = td; 2134 } else { 2135 *ttd = NULL; 2136 PROC_LOCK(p); 2137 } 2138 return (0); 2139 } 2140 2141 void 2142 tdsignal(struct thread *td, int sig) 2143 { 2144 ksiginfo_t ksi; 2145 2146 ksiginfo_init(&ksi); 2147 ksi.ksi_signo = sig; 2148 ksi.ksi_code = SI_KERNEL; 2149 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2150 } 2151 2152 void 2153 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2154 { 2155 2156 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2157 } 2158 2159 int 2160 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2161 { 2162 sig_t action; 2163 sigqueue_t *sigqueue; 2164 int prop; 2165 struct sigacts *ps; 2166 int intrval; 2167 int ret = 0; 2168 int wakeup_swapper; 2169 2170 MPASS(td == NULL || p == td->td_proc); 2171 PROC_LOCK_ASSERT(p, MA_OWNED); 2172 2173 if (!_SIG_VALID(sig)) 2174 panic("%s(): invalid signal %d", __func__, sig); 2175 2176 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2177 2178 /* 2179 * IEEE Std 1003.1-2001: return success when killing a zombie. 2180 */ 2181 if (p->p_state == PRS_ZOMBIE) { 2182 if (ksi && (ksi->ksi_flags & KSI_INS)) 2183 ksiginfo_tryfree(ksi); 2184 return (ret); 2185 } 2186 2187 ps = p->p_sigacts; 2188 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2189 prop = sigprop(sig); 2190 2191 if (td == NULL) { 2192 td = sigtd(p, sig, false); 2193 sigqueue = &p->p_sigqueue; 2194 } else 2195 sigqueue = &td->td_sigqueue; 2196 2197 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2198 2199 /* 2200 * If the signal is being ignored, 2201 * then we forget about it immediately. 2202 * (Note: we don't set SIGCONT in ps_sigignore, 2203 * and if it is set to SIG_IGN, 2204 * action will be SIG_DFL here.) 2205 */ 2206 mtx_lock(&ps->ps_mtx); 2207 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2208 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2209 2210 mtx_unlock(&ps->ps_mtx); 2211 if (ksi && (ksi->ksi_flags & KSI_INS)) 2212 ksiginfo_tryfree(ksi); 2213 return (ret); 2214 } 2215 if (SIGISMEMBER(td->td_sigmask, sig)) 2216 action = SIG_HOLD; 2217 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2218 action = SIG_CATCH; 2219 else 2220 action = SIG_DFL; 2221 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2222 intrval = EINTR; 2223 else 2224 intrval = ERESTART; 2225 mtx_unlock(&ps->ps_mtx); 2226 2227 if (prop & SIGPROP_CONT) 2228 sigqueue_delete_stopmask_proc(p); 2229 else if (prop & SIGPROP_STOP) { 2230 /* 2231 * If sending a tty stop signal to a member of an orphaned 2232 * process group, discard the signal here if the action 2233 * is default; don't stop the process below if sleeping, 2234 * and don't clear any pending SIGCONT. 2235 */ 2236 if ((prop & SIGPROP_TTYSTOP) != 0 && 2237 (p->p_pgrp->pg_flags & PGRP_ORPHANED) != 0 && 2238 action == SIG_DFL) { 2239 if (ksi && (ksi->ksi_flags & KSI_INS)) 2240 ksiginfo_tryfree(ksi); 2241 return (ret); 2242 } 2243 sigqueue_delete_proc(p, SIGCONT); 2244 if (p->p_flag & P_CONTINUED) { 2245 p->p_flag &= ~P_CONTINUED; 2246 PROC_LOCK(p->p_pptr); 2247 sigqueue_take(p->p_ksi); 2248 PROC_UNLOCK(p->p_pptr); 2249 } 2250 } 2251 2252 ret = sigqueue_add(sigqueue, sig, ksi); 2253 if (ret != 0) 2254 return (ret); 2255 signotify(td); 2256 /* 2257 * Defer further processing for signals which are held, 2258 * except that stopped processes must be continued by SIGCONT. 2259 */ 2260 if (action == SIG_HOLD && 2261 !((prop & SIGPROP_CONT) && (p->p_flag & P_STOPPED_SIG))) 2262 return (ret); 2263 2264 wakeup_swapper = 0; 2265 2266 /* 2267 * Some signals have a process-wide effect and a per-thread 2268 * component. Most processing occurs when the process next 2269 * tries to cross the user boundary, however there are some 2270 * times when processing needs to be done immediately, such as 2271 * waking up threads so that they can cross the user boundary. 2272 * We try to do the per-process part here. 2273 */ 2274 if (P_SHOULDSTOP(p)) { 2275 KASSERT(!(p->p_flag & P_WEXIT), 2276 ("signal to stopped but exiting process")); 2277 if (sig == SIGKILL) { 2278 /* 2279 * If traced process is already stopped, 2280 * then no further action is necessary. 2281 */ 2282 if (p->p_flag & P_TRACED) 2283 goto out; 2284 /* 2285 * SIGKILL sets process running. 2286 * It will die elsewhere. 2287 * All threads must be restarted. 2288 */ 2289 p->p_flag &= ~P_STOPPED_SIG; 2290 goto runfast; 2291 } 2292 2293 if (prop & SIGPROP_CONT) { 2294 /* 2295 * If traced process is already stopped, 2296 * then no further action is necessary. 2297 */ 2298 if (p->p_flag & P_TRACED) 2299 goto out; 2300 /* 2301 * If SIGCONT is default (or ignored), we continue the 2302 * process but don't leave the signal in sigqueue as 2303 * it has no further action. If SIGCONT is held, we 2304 * continue the process and leave the signal in 2305 * sigqueue. If the process catches SIGCONT, let it 2306 * handle the signal itself. If it isn't waiting on 2307 * an event, it goes back to run state. 2308 * Otherwise, process goes back to sleep state. 2309 */ 2310 p->p_flag &= ~P_STOPPED_SIG; 2311 PROC_SLOCK(p); 2312 if (p->p_numthreads == p->p_suspcount) { 2313 PROC_SUNLOCK(p); 2314 p->p_flag |= P_CONTINUED; 2315 p->p_xsig = SIGCONT; 2316 PROC_LOCK(p->p_pptr); 2317 childproc_continued(p); 2318 PROC_UNLOCK(p->p_pptr); 2319 PROC_SLOCK(p); 2320 } 2321 if (action == SIG_DFL) { 2322 thread_unsuspend(p); 2323 PROC_SUNLOCK(p); 2324 sigqueue_delete(sigqueue, sig); 2325 goto out_cont; 2326 } 2327 if (action == SIG_CATCH) { 2328 /* 2329 * The process wants to catch it so it needs 2330 * to run at least one thread, but which one? 2331 */ 2332 PROC_SUNLOCK(p); 2333 goto runfast; 2334 } 2335 /* 2336 * The signal is not ignored or caught. 2337 */ 2338 thread_unsuspend(p); 2339 PROC_SUNLOCK(p); 2340 goto out_cont; 2341 } 2342 2343 if (prop & SIGPROP_STOP) { 2344 /* 2345 * If traced process is already stopped, 2346 * then no further action is necessary. 2347 */ 2348 if (p->p_flag & P_TRACED) 2349 goto out; 2350 /* 2351 * Already stopped, don't need to stop again 2352 * (If we did the shell could get confused). 2353 * Just make sure the signal STOP bit set. 2354 */ 2355 p->p_flag |= P_STOPPED_SIG; 2356 sigqueue_delete(sigqueue, sig); 2357 goto out; 2358 } 2359 2360 /* 2361 * All other kinds of signals: 2362 * If a thread is sleeping interruptibly, simulate a 2363 * wakeup so that when it is continued it will be made 2364 * runnable and can look at the signal. However, don't make 2365 * the PROCESS runnable, leave it stopped. 2366 * It may run a bit until it hits a thread_suspend_check(). 2367 */ 2368 PROC_SLOCK(p); 2369 thread_lock(td); 2370 if (TD_CAN_ABORT(td)) 2371 wakeup_swapper = sleepq_abort(td, intrval); 2372 else 2373 thread_unlock(td); 2374 PROC_SUNLOCK(p); 2375 goto out; 2376 /* 2377 * Mutexes are short lived. Threads waiting on them will 2378 * hit thread_suspend_check() soon. 2379 */ 2380 } else if (p->p_state == PRS_NORMAL) { 2381 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2382 tdsigwakeup(td, sig, action, intrval); 2383 goto out; 2384 } 2385 2386 MPASS(action == SIG_DFL); 2387 2388 if (prop & SIGPROP_STOP) { 2389 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2390 goto out; 2391 p->p_flag |= P_STOPPED_SIG; 2392 p->p_xsig = sig; 2393 PROC_SLOCK(p); 2394 wakeup_swapper = sig_suspend_threads(td, p, 1); 2395 if (p->p_numthreads == p->p_suspcount) { 2396 /* 2397 * only thread sending signal to another 2398 * process can reach here, if thread is sending 2399 * signal to its process, because thread does 2400 * not suspend itself here, p_numthreads 2401 * should never be equal to p_suspcount. 2402 */ 2403 thread_stopped(p); 2404 PROC_SUNLOCK(p); 2405 sigqueue_delete_proc(p, p->p_xsig); 2406 } else 2407 PROC_SUNLOCK(p); 2408 goto out; 2409 } 2410 } else { 2411 /* Not in "NORMAL" state. discard the signal. */ 2412 sigqueue_delete(sigqueue, sig); 2413 goto out; 2414 } 2415 2416 /* 2417 * The process is not stopped so we need to apply the signal to all the 2418 * running threads. 2419 */ 2420 runfast: 2421 tdsigwakeup(td, sig, action, intrval); 2422 PROC_SLOCK(p); 2423 thread_unsuspend(p); 2424 PROC_SUNLOCK(p); 2425 out_cont: 2426 itimer_proc_continue(p); 2427 kqtimer_proc_continue(p); 2428 out: 2429 /* If we jump here, proc slock should not be owned. */ 2430 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2431 if (wakeup_swapper) 2432 kick_proc0(); 2433 2434 return (ret); 2435 } 2436 2437 /* 2438 * The force of a signal has been directed against a single 2439 * thread. We need to see what we can do about knocking it 2440 * out of any sleep it may be in etc. 2441 */ 2442 static void 2443 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2444 { 2445 struct proc *p = td->td_proc; 2446 int prop, wakeup_swapper; 2447 2448 PROC_LOCK_ASSERT(p, MA_OWNED); 2449 prop = sigprop(sig); 2450 2451 PROC_SLOCK(p); 2452 thread_lock(td); 2453 /* 2454 * Bring the priority of a thread up if we want it to get 2455 * killed in this lifetime. Be careful to avoid bumping the 2456 * priority of the idle thread, since we still allow to signal 2457 * kernel processes. 2458 */ 2459 if (action == SIG_DFL && (prop & SIGPROP_KILL) != 0 && 2460 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2461 sched_prio(td, PUSER); 2462 if (TD_ON_SLEEPQ(td)) { 2463 /* 2464 * If thread is sleeping uninterruptibly 2465 * we can't interrupt the sleep... the signal will 2466 * be noticed when the process returns through 2467 * trap() or syscall(). 2468 */ 2469 if ((td->td_flags & TDF_SINTR) == 0) 2470 goto out; 2471 /* 2472 * If SIGCONT is default (or ignored) and process is 2473 * asleep, we are finished; the process should not 2474 * be awakened. 2475 */ 2476 if ((prop & SIGPROP_CONT) && action == SIG_DFL) { 2477 thread_unlock(td); 2478 PROC_SUNLOCK(p); 2479 sigqueue_delete(&p->p_sigqueue, sig); 2480 /* 2481 * It may be on either list in this state. 2482 * Remove from both for now. 2483 */ 2484 sigqueue_delete(&td->td_sigqueue, sig); 2485 return; 2486 } 2487 2488 /* 2489 * Don't awaken a sleeping thread for SIGSTOP if the 2490 * STOP signal is deferred. 2491 */ 2492 if ((prop & SIGPROP_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2493 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2494 goto out; 2495 2496 /* 2497 * Give low priority threads a better chance to run. 2498 */ 2499 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2500 sched_prio(td, PUSER); 2501 2502 wakeup_swapper = sleepq_abort(td, intrval); 2503 PROC_SUNLOCK(p); 2504 if (wakeup_swapper) 2505 kick_proc0(); 2506 return; 2507 } 2508 2509 /* 2510 * Other states do nothing with the signal immediately, 2511 * other than kicking ourselves if we are running. 2512 * It will either never be noticed, or noticed very soon. 2513 */ 2514 #ifdef SMP 2515 if (TD_IS_RUNNING(td) && td != curthread) 2516 forward_signal(td); 2517 #endif 2518 2519 out: 2520 PROC_SUNLOCK(p); 2521 thread_unlock(td); 2522 } 2523 2524 static int 2525 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2526 { 2527 struct thread *td2; 2528 int wakeup_swapper; 2529 2530 PROC_LOCK_ASSERT(p, MA_OWNED); 2531 PROC_SLOCK_ASSERT(p, MA_OWNED); 2532 MPASS(sending || td == curthread); 2533 2534 wakeup_swapper = 0; 2535 FOREACH_THREAD_IN_PROC(p, td2) { 2536 thread_lock(td2); 2537 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2538 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2539 (td2->td_flags & TDF_SINTR)) { 2540 if (td2->td_flags & TDF_SBDRY) { 2541 /* 2542 * Once a thread is asleep with 2543 * TDF_SBDRY and without TDF_SERESTART 2544 * or TDF_SEINTR set, it should never 2545 * become suspended due to this check. 2546 */ 2547 KASSERT(!TD_IS_SUSPENDED(td2), 2548 ("thread with deferred stops suspended")); 2549 if (TD_SBDRY_INTR(td2)) { 2550 wakeup_swapper |= sleepq_abort(td2, 2551 TD_SBDRY_ERRNO(td2)); 2552 continue; 2553 } 2554 } else if (!TD_IS_SUSPENDED(td2)) 2555 thread_suspend_one(td2); 2556 } else if (!TD_IS_SUSPENDED(td2)) { 2557 if (sending || td != td2) 2558 td2->td_flags |= TDF_ASTPENDING; 2559 #ifdef SMP 2560 if (TD_IS_RUNNING(td2) && td2 != td) 2561 forward_signal(td2); 2562 #endif 2563 } 2564 thread_unlock(td2); 2565 } 2566 return (wakeup_swapper); 2567 } 2568 2569 /* 2570 * Stop the process for an event deemed interesting to the debugger. If si is 2571 * non-NULL, this is a signal exchange; the new signal requested by the 2572 * debugger will be returned for handling. If si is NULL, this is some other 2573 * type of interesting event. The debugger may request a signal be delivered in 2574 * that case as well, however it will be deferred until it can be handled. 2575 */ 2576 int 2577 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2578 { 2579 struct proc *p = td->td_proc; 2580 struct thread *td2; 2581 ksiginfo_t ksi; 2582 2583 PROC_LOCK_ASSERT(p, MA_OWNED); 2584 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2585 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2586 &p->p_mtx.lock_object, "Stopping for traced signal"); 2587 2588 td->td_xsig = sig; 2589 2590 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2591 td->td_dbgflags |= TDB_XSIG; 2592 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2593 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2594 PROC_SLOCK(p); 2595 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2596 if (P_KILLED(p)) { 2597 /* 2598 * Ensure that, if we've been PT_KILLed, the 2599 * exit status reflects that. Another thread 2600 * may also be in ptracestop(), having just 2601 * received the SIGKILL, but this thread was 2602 * unsuspended first. 2603 */ 2604 td->td_dbgflags &= ~TDB_XSIG; 2605 td->td_xsig = SIGKILL; 2606 p->p_ptevents = 0; 2607 break; 2608 } 2609 if (p->p_flag & P_SINGLE_EXIT && 2610 !(td->td_dbgflags & TDB_EXIT)) { 2611 /* 2612 * Ignore ptrace stops except for thread exit 2613 * events when the process exits. 2614 */ 2615 td->td_dbgflags &= ~TDB_XSIG; 2616 PROC_SUNLOCK(p); 2617 return (0); 2618 } 2619 2620 /* 2621 * Make wait(2) work. Ensure that right after the 2622 * attach, the thread which was decided to become the 2623 * leader of attach gets reported to the waiter. 2624 * Otherwise, just avoid overwriting another thread's 2625 * assignment to p_xthread. If another thread has 2626 * already set p_xthread, the current thread will get 2627 * a chance to report itself upon the next iteration. 2628 */ 2629 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2630 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2631 p->p_xthread == NULL)) { 2632 p->p_xsig = sig; 2633 p->p_xthread = td; 2634 2635 /* 2636 * If we are on sleepqueue already, 2637 * let sleepqueue code decide if it 2638 * needs to go sleep after attach. 2639 */ 2640 if (td->td_wchan == NULL) 2641 td->td_dbgflags &= ~TDB_FSTP; 2642 2643 p->p_flag2 &= ~P2_PTRACE_FSTP; 2644 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2645 sig_suspend_threads(td, p, 0); 2646 } 2647 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2648 td->td_dbgflags &= ~TDB_STOPATFORK; 2649 } 2650 stopme: 2651 thread_suspend_switch(td, p); 2652 if (p->p_xthread == td) 2653 p->p_xthread = NULL; 2654 if (!(p->p_flag & P_TRACED)) 2655 break; 2656 if (td->td_dbgflags & TDB_SUSPEND) { 2657 if (p->p_flag & P_SINGLE_EXIT) 2658 break; 2659 goto stopme; 2660 } 2661 } 2662 PROC_SUNLOCK(p); 2663 } 2664 2665 if (si != NULL && sig == td->td_xsig) { 2666 /* Parent wants us to take the original signal unchanged. */ 2667 si->ksi_flags |= KSI_HEAD; 2668 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2669 si->ksi_signo = 0; 2670 } else if (td->td_xsig != 0) { 2671 /* 2672 * If parent wants us to take a new signal, then it will leave 2673 * it in td->td_xsig; otherwise we just look for signals again. 2674 */ 2675 ksiginfo_init(&ksi); 2676 ksi.ksi_signo = td->td_xsig; 2677 ksi.ksi_flags |= KSI_PTRACE; 2678 td2 = sigtd(p, td->td_xsig, false); 2679 tdsendsignal(p, td2, td->td_xsig, &ksi); 2680 if (td != td2) 2681 return (0); 2682 } 2683 2684 return (td->td_xsig); 2685 } 2686 2687 static void 2688 reschedule_signals(struct proc *p, sigset_t block, int flags) 2689 { 2690 struct sigacts *ps; 2691 struct thread *td; 2692 int sig; 2693 bool fastblk, pslocked; 2694 2695 PROC_LOCK_ASSERT(p, MA_OWNED); 2696 ps = p->p_sigacts; 2697 pslocked = (flags & SIGPROCMASK_PS_LOCKED) != 0; 2698 mtx_assert(&ps->ps_mtx, pslocked ? MA_OWNED : MA_NOTOWNED); 2699 if (SIGISEMPTY(p->p_siglist)) 2700 return; 2701 SIGSETAND(block, p->p_siglist); 2702 fastblk = (flags & SIGPROCMASK_FASTBLK) != 0; 2703 while ((sig = sig_ffs(&block)) != 0) { 2704 SIGDELSET(block, sig); 2705 td = sigtd(p, sig, fastblk); 2706 2707 /* 2708 * If sigtd() selected us despite sigfastblock is 2709 * blocking, do not activate AST or wake us, to avoid 2710 * loop in AST handler. 2711 */ 2712 if (fastblk && td == curthread) 2713 continue; 2714 2715 signotify(td); 2716 if (!pslocked) 2717 mtx_lock(&ps->ps_mtx); 2718 if (p->p_flag & P_TRACED || 2719 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2720 !SIGISMEMBER(td->td_sigmask, sig))) { 2721 tdsigwakeup(td, sig, SIG_CATCH, 2722 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2723 ERESTART)); 2724 } 2725 if (!pslocked) 2726 mtx_unlock(&ps->ps_mtx); 2727 } 2728 } 2729 2730 void 2731 tdsigcleanup(struct thread *td) 2732 { 2733 struct proc *p; 2734 sigset_t unblocked; 2735 2736 p = td->td_proc; 2737 PROC_LOCK_ASSERT(p, MA_OWNED); 2738 2739 sigqueue_flush(&td->td_sigqueue); 2740 if (p->p_numthreads == 1) 2741 return; 2742 2743 /* 2744 * Since we cannot handle signals, notify signal post code 2745 * about this by filling the sigmask. 2746 * 2747 * Also, if needed, wake up thread(s) that do not block the 2748 * same signals as the exiting thread, since the thread might 2749 * have been selected for delivery and woken up. 2750 */ 2751 SIGFILLSET(unblocked); 2752 SIGSETNAND(unblocked, td->td_sigmask); 2753 SIGFILLSET(td->td_sigmask); 2754 reschedule_signals(p, unblocked, 0); 2755 2756 } 2757 2758 static int 2759 sigdeferstop_curr_flags(int cflags) 2760 { 2761 2762 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2763 (cflags & TDF_SBDRY) != 0); 2764 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2765 } 2766 2767 /* 2768 * Defer the delivery of SIGSTOP for the current thread, according to 2769 * the requested mode. Returns previous flags, which must be restored 2770 * by sigallowstop(). 2771 * 2772 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2773 * cleared by the current thread, which allow the lock-less read-only 2774 * accesses below. 2775 */ 2776 int 2777 sigdeferstop_impl(int mode) 2778 { 2779 struct thread *td; 2780 int cflags, nflags; 2781 2782 td = curthread; 2783 cflags = sigdeferstop_curr_flags(td->td_flags); 2784 switch (mode) { 2785 case SIGDEFERSTOP_NOP: 2786 nflags = cflags; 2787 break; 2788 case SIGDEFERSTOP_OFF: 2789 nflags = 0; 2790 break; 2791 case SIGDEFERSTOP_SILENT: 2792 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2793 break; 2794 case SIGDEFERSTOP_EINTR: 2795 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2796 break; 2797 case SIGDEFERSTOP_ERESTART: 2798 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2799 break; 2800 default: 2801 panic("sigdeferstop: invalid mode %x", mode); 2802 break; 2803 } 2804 if (cflags == nflags) 2805 return (SIGDEFERSTOP_VAL_NCHG); 2806 thread_lock(td); 2807 td->td_flags = (td->td_flags & ~cflags) | nflags; 2808 thread_unlock(td); 2809 return (cflags); 2810 } 2811 2812 /* 2813 * Restores the STOP handling mode, typically permitting the delivery 2814 * of SIGSTOP for the current thread. This does not immediately 2815 * suspend if a stop was posted. Instead, the thread will suspend 2816 * either via ast() or a subsequent interruptible sleep. 2817 */ 2818 void 2819 sigallowstop_impl(int prev) 2820 { 2821 struct thread *td; 2822 int cflags; 2823 2824 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2825 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2826 ("sigallowstop: incorrect previous mode %x", prev)); 2827 td = curthread; 2828 cflags = sigdeferstop_curr_flags(td->td_flags); 2829 if (cflags != prev) { 2830 thread_lock(td); 2831 td->td_flags = (td->td_flags & ~cflags) | prev; 2832 thread_unlock(td); 2833 } 2834 } 2835 2836 /* 2837 * If the current process has received a signal (should be caught or cause 2838 * termination, should interrupt current syscall), return the signal number. 2839 * Stop signals with default action are processed immediately, then cleared; 2840 * they aren't returned. This is checked after each entry to the system for 2841 * a syscall or trap (though this can usually be done without calling issignal 2842 * by checking the pending signal masks in cursig.) The normal call 2843 * sequence is 2844 * 2845 * while (sig = cursig(curthread)) 2846 * postsig(sig); 2847 */ 2848 static int 2849 issignal(struct thread *td) 2850 { 2851 struct proc *p; 2852 struct sigacts *ps; 2853 struct sigqueue *queue; 2854 sigset_t sigpending; 2855 ksiginfo_t ksi; 2856 int prop, sig; 2857 2858 p = td->td_proc; 2859 ps = p->p_sigacts; 2860 mtx_assert(&ps->ps_mtx, MA_OWNED); 2861 PROC_LOCK_ASSERT(p, MA_OWNED); 2862 for (;;) { 2863 sigpending = td->td_sigqueue.sq_signals; 2864 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2865 SIGSETNAND(sigpending, td->td_sigmask); 2866 2867 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2868 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2869 SIG_STOPSIGMASK(sigpending); 2870 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2871 return (0); 2872 2873 /* 2874 * Do fast sigblock if requested by usermode. Since 2875 * we do know that there was a signal pending at this 2876 * point, set the FAST_SIGBLOCK_PEND as indicator for 2877 * usermode to perform a dummy call to 2878 * FAST_SIGBLOCK_UNBLOCK, which causes immediate 2879 * delivery of postponed pending signal. 2880 */ 2881 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 2882 if (td->td_sigblock_val != 0) 2883 SIGSETNAND(sigpending, fastblock_mask); 2884 if (SIGISEMPTY(sigpending)) { 2885 td->td_pflags |= TDP_SIGFASTPENDING; 2886 return (0); 2887 } 2888 } 2889 2890 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2891 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2892 SIGISMEMBER(sigpending, SIGSTOP)) { 2893 /* 2894 * If debugger just attached, always consume 2895 * SIGSTOP from ptrace(PT_ATTACH) first, to 2896 * execute the debugger attach ritual in 2897 * order. 2898 */ 2899 sig = SIGSTOP; 2900 td->td_dbgflags |= TDB_FSTP; 2901 } else { 2902 sig = sig_ffs(&sigpending); 2903 } 2904 2905 /* 2906 * We should see pending but ignored signals 2907 * only if P_TRACED was on when they were posted. 2908 */ 2909 if (SIGISMEMBER(ps->ps_sigignore, sig) && 2910 (p->p_flag & P_TRACED) == 0) { 2911 sigqueue_delete(&td->td_sigqueue, sig); 2912 sigqueue_delete(&p->p_sigqueue, sig); 2913 continue; 2914 } 2915 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2916 /* 2917 * If traced, always stop. 2918 * Remove old signal from queue before the stop. 2919 * XXX shrug off debugger, it causes siginfo to 2920 * be thrown away. 2921 */ 2922 queue = &td->td_sigqueue; 2923 ksiginfo_init(&ksi); 2924 if (sigqueue_get(queue, sig, &ksi) == 0) { 2925 queue = &p->p_sigqueue; 2926 sigqueue_get(queue, sig, &ksi); 2927 } 2928 td->td_si = ksi.ksi_info; 2929 2930 mtx_unlock(&ps->ps_mtx); 2931 sig = ptracestop(td, sig, &ksi); 2932 mtx_lock(&ps->ps_mtx); 2933 2934 td->td_si.si_signo = 0; 2935 2936 /* 2937 * Keep looking if the debugger discarded or 2938 * replaced the signal. 2939 */ 2940 if (sig == 0) 2941 continue; 2942 2943 /* 2944 * If the signal became masked, re-queue it. 2945 */ 2946 if (SIGISMEMBER(td->td_sigmask, sig)) { 2947 ksi.ksi_flags |= KSI_HEAD; 2948 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2949 continue; 2950 } 2951 2952 /* 2953 * If the traced bit got turned off, requeue 2954 * the signal and go back up to the top to 2955 * rescan signals. This ensures that p_sig* 2956 * and p_sigact are consistent. 2957 */ 2958 if ((p->p_flag & P_TRACED) == 0) { 2959 ksi.ksi_flags |= KSI_HEAD; 2960 sigqueue_add(queue, sig, &ksi); 2961 continue; 2962 } 2963 } 2964 2965 prop = sigprop(sig); 2966 2967 /* 2968 * Decide whether the signal should be returned. 2969 * Return the signal's number, or fall through 2970 * to clear it from the pending mask. 2971 */ 2972 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2973 case (intptr_t)SIG_DFL: 2974 /* 2975 * Don't take default actions on system processes. 2976 */ 2977 if (p->p_pid <= 1) { 2978 #ifdef DIAGNOSTIC 2979 /* 2980 * Are you sure you want to ignore SIGSEGV 2981 * in init? XXX 2982 */ 2983 printf("Process (pid %lu) got signal %d\n", 2984 (u_long)p->p_pid, sig); 2985 #endif 2986 break; /* == ignore */ 2987 } 2988 /* 2989 * If there is a pending stop signal to process with 2990 * default action, stop here, then clear the signal. 2991 * Traced or exiting processes should ignore stops. 2992 * Additionally, a member of an orphaned process group 2993 * should ignore tty stops. 2994 */ 2995 if (prop & SIGPROP_STOP) { 2996 mtx_unlock(&ps->ps_mtx); 2997 if ((p->p_flag & (P_TRACED | P_WEXIT | 2998 P_SINGLE_EXIT)) != 0 || ((p->p_pgrp-> 2999 pg_flags & PGRP_ORPHANED) != 0 && 3000 (prop & SIGPROP_TTYSTOP) != 0)) { 3001 mtx_lock(&ps->ps_mtx); 3002 break; /* == ignore */ 3003 } 3004 if (TD_SBDRY_INTR(td)) { 3005 KASSERT((td->td_flags & TDF_SBDRY) != 0, 3006 ("lost TDF_SBDRY")); 3007 mtx_lock(&ps->ps_mtx); 3008 return (-1); 3009 } 3010 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 3011 &p->p_mtx.lock_object, "Catching SIGSTOP"); 3012 sigqueue_delete(&td->td_sigqueue, sig); 3013 sigqueue_delete(&p->p_sigqueue, sig); 3014 p->p_flag |= P_STOPPED_SIG; 3015 p->p_xsig = sig; 3016 PROC_SLOCK(p); 3017 sig_suspend_threads(td, p, 0); 3018 thread_suspend_switch(td, p); 3019 PROC_SUNLOCK(p); 3020 mtx_lock(&ps->ps_mtx); 3021 goto next; 3022 } else if (prop & SIGPROP_IGNORE) { 3023 /* 3024 * Except for SIGCONT, shouldn't get here. 3025 * Default action is to ignore; drop it. 3026 */ 3027 break; /* == ignore */ 3028 } else 3029 return (sig); 3030 /*NOTREACHED*/ 3031 3032 case (intptr_t)SIG_IGN: 3033 /* 3034 * Masking above should prevent us ever trying 3035 * to take action on an ignored signal other 3036 * than SIGCONT, unless process is traced. 3037 */ 3038 if ((prop & SIGPROP_CONT) == 0 && 3039 (p->p_flag & P_TRACED) == 0) 3040 printf("issignal\n"); 3041 break; /* == ignore */ 3042 3043 default: 3044 /* 3045 * This signal has an action, let 3046 * postsig() process it. 3047 */ 3048 return (sig); 3049 } 3050 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3051 sigqueue_delete(&p->p_sigqueue, sig); 3052 next:; 3053 } 3054 /* NOTREACHED */ 3055 } 3056 3057 void 3058 thread_stopped(struct proc *p) 3059 { 3060 int n; 3061 3062 PROC_LOCK_ASSERT(p, MA_OWNED); 3063 PROC_SLOCK_ASSERT(p, MA_OWNED); 3064 n = p->p_suspcount; 3065 if (p == curproc) 3066 n++; 3067 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3068 PROC_SUNLOCK(p); 3069 p->p_flag &= ~P_WAITED; 3070 PROC_LOCK(p->p_pptr); 3071 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3072 CLD_TRAPPED : CLD_STOPPED); 3073 PROC_UNLOCK(p->p_pptr); 3074 PROC_SLOCK(p); 3075 } 3076 } 3077 3078 /* 3079 * Take the action for the specified signal 3080 * from the current set of pending signals. 3081 */ 3082 int 3083 postsig(int sig) 3084 { 3085 struct thread *td; 3086 struct proc *p; 3087 struct sigacts *ps; 3088 sig_t action; 3089 ksiginfo_t ksi; 3090 sigset_t returnmask; 3091 3092 KASSERT(sig != 0, ("postsig")); 3093 3094 td = curthread; 3095 p = td->td_proc; 3096 PROC_LOCK_ASSERT(p, MA_OWNED); 3097 ps = p->p_sigacts; 3098 mtx_assert(&ps->ps_mtx, MA_OWNED); 3099 ksiginfo_init(&ksi); 3100 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3101 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3102 return (0); 3103 ksi.ksi_signo = sig; 3104 if (ksi.ksi_code == SI_TIMER) 3105 itimer_accept(p, ksi.ksi_timerid, &ksi); 3106 action = ps->ps_sigact[_SIG_IDX(sig)]; 3107 #ifdef KTRACE 3108 if (KTRPOINT(td, KTR_PSIG)) 3109 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3110 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3111 #endif 3112 3113 if (action == SIG_DFL) { 3114 /* 3115 * Default action, where the default is to kill 3116 * the process. (Other cases were ignored above.) 3117 */ 3118 mtx_unlock(&ps->ps_mtx); 3119 proc_td_siginfo_capture(td, &ksi.ksi_info); 3120 sigexit(td, sig); 3121 /* NOTREACHED */ 3122 } else { 3123 /* 3124 * If we get here, the signal must be caught. 3125 */ 3126 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3127 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3128 ("postsig action: blocked sig %d", sig)); 3129 3130 /* 3131 * Set the new mask value and also defer further 3132 * occurrences of this signal. 3133 * 3134 * Special case: user has done a sigsuspend. Here the 3135 * current mask is not of interest, but rather the 3136 * mask from before the sigsuspend is what we want 3137 * restored after the signal processing is completed. 3138 */ 3139 if (td->td_pflags & TDP_OLDMASK) { 3140 returnmask = td->td_oldsigmask; 3141 td->td_pflags &= ~TDP_OLDMASK; 3142 } else 3143 returnmask = td->td_sigmask; 3144 3145 if (p->p_sig == sig) { 3146 p->p_sig = 0; 3147 } 3148 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3149 postsig_done(sig, td, ps); 3150 } 3151 return (1); 3152 } 3153 3154 int 3155 sig_ast_checksusp(struct thread *td) 3156 { 3157 struct proc *p; 3158 int ret; 3159 3160 p = td->td_proc; 3161 PROC_LOCK_ASSERT(p, MA_OWNED); 3162 3163 if ((td->td_flags & TDF_NEEDSUSPCHK) == 0) 3164 return (0); 3165 3166 ret = thread_suspend_check(1); 3167 MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 3168 return (ret); 3169 } 3170 3171 int 3172 sig_ast_needsigchk(struct thread *td) 3173 { 3174 struct proc *p; 3175 struct sigacts *ps; 3176 int ret, sig; 3177 3178 p = td->td_proc; 3179 PROC_LOCK_ASSERT(p, MA_OWNED); 3180 3181 if ((td->td_flags & TDF_NEEDSIGCHK) == 0) 3182 return (0); 3183 3184 ps = p->p_sigacts; 3185 mtx_lock(&ps->ps_mtx); 3186 sig = cursig(td); 3187 if (sig == -1) { 3188 mtx_unlock(&ps->ps_mtx); 3189 KASSERT((td->td_flags & TDF_SBDRY) != 0, ("lost TDF_SBDRY")); 3190 KASSERT(TD_SBDRY_INTR(td), 3191 ("lost TDF_SERESTART of TDF_SEINTR")); 3192 KASSERT((td->td_flags & (TDF_SEINTR | TDF_SERESTART)) != 3193 (TDF_SEINTR | TDF_SERESTART), 3194 ("both TDF_SEINTR and TDF_SERESTART")); 3195 ret = TD_SBDRY_ERRNO(td); 3196 } else if (sig != 0) { 3197 ret = SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : ERESTART; 3198 mtx_unlock(&ps->ps_mtx); 3199 } else { 3200 mtx_unlock(&ps->ps_mtx); 3201 ret = 0; 3202 } 3203 3204 /* 3205 * Do not go into sleep if this thread was the ptrace(2) 3206 * attach leader. cursig() consumed SIGSTOP from PT_ATTACH, 3207 * but we usually act on the signal by interrupting sleep, and 3208 * should do that here as well. 3209 */ 3210 if ((td->td_dbgflags & TDB_FSTP) != 0) { 3211 if (ret == 0) 3212 ret = EINTR; 3213 td->td_dbgflags &= ~TDB_FSTP; 3214 } 3215 3216 return (ret); 3217 } 3218 3219 int 3220 sig_intr(void) 3221 { 3222 struct thread *td; 3223 struct proc *p; 3224 int ret; 3225 3226 td = curthread; 3227 if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) 3228 return (0); 3229 3230 p = td->td_proc; 3231 3232 PROC_LOCK(p); 3233 ret = sig_ast_checksusp(td); 3234 if (ret == 0) 3235 ret = sig_ast_needsigchk(td); 3236 PROC_UNLOCK(p); 3237 return (ret); 3238 } 3239 3240 void 3241 proc_wkilled(struct proc *p) 3242 { 3243 3244 PROC_LOCK_ASSERT(p, MA_OWNED); 3245 if ((p->p_flag & P_WKILLED) == 0) { 3246 p->p_flag |= P_WKILLED; 3247 /* 3248 * Notify swapper that there is a process to swap in. 3249 * The notification is racy, at worst it would take 10 3250 * seconds for the swapper process to notice. 3251 */ 3252 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3253 wakeup(&proc0); 3254 } 3255 } 3256 3257 /* 3258 * Kill the current process for stated reason. 3259 */ 3260 void 3261 killproc(struct proc *p, const char *why) 3262 { 3263 3264 PROC_LOCK_ASSERT(p, MA_OWNED); 3265 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3266 p->p_comm); 3267 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3268 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3269 p->p_ucred->cr_uid, why); 3270 proc_wkilled(p); 3271 kern_psignal(p, SIGKILL); 3272 } 3273 3274 /* 3275 * Force the current process to exit with the specified signal, dumping core 3276 * if appropriate. We bypass the normal tests for masked and caught signals, 3277 * allowing unrecoverable failures to terminate the process without changing 3278 * signal state. Mark the accounting record with the signal termination. 3279 * If dumping core, save the signal number for the debugger. Calls exit and 3280 * does not return. 3281 */ 3282 void 3283 sigexit(struct thread *td, int sig) 3284 { 3285 struct proc *p = td->td_proc; 3286 3287 PROC_LOCK_ASSERT(p, MA_OWNED); 3288 p->p_acflag |= AXSIG; 3289 /* 3290 * We must be single-threading to generate a core dump. This 3291 * ensures that the registers in the core file are up-to-date. 3292 * Also, the ELF dump handler assumes that the thread list doesn't 3293 * change out from under it. 3294 * 3295 * XXX If another thread attempts to single-thread before us 3296 * (e.g. via fork()), we won't get a dump at all. 3297 */ 3298 if ((sigprop(sig) & SIGPROP_CORE) && 3299 thread_single(p, SINGLE_NO_EXIT) == 0) { 3300 p->p_sig = sig; 3301 /* 3302 * Log signals which would cause core dumps 3303 * (Log as LOG_INFO to appease those who don't want 3304 * these messages.) 3305 * XXX : Todo, as well as euid, write out ruid too 3306 * Note that coredump() drops proc lock. 3307 */ 3308 if (coredump(td) == 0) 3309 sig |= WCOREFLAG; 3310 if (kern_logsigexit) 3311 log(LOG_INFO, 3312 "pid %d (%s), jid %d, uid %d: exited on " 3313 "signal %d%s\n", p->p_pid, p->p_comm, 3314 p->p_ucred->cr_prison->pr_id, 3315 td->td_ucred->cr_uid, 3316 sig &~ WCOREFLAG, 3317 sig & WCOREFLAG ? " (core dumped)" : ""); 3318 } else 3319 PROC_UNLOCK(p); 3320 exit1(td, 0, sig); 3321 /* NOTREACHED */ 3322 } 3323 3324 /* 3325 * Send queued SIGCHLD to parent when child process's state 3326 * is changed. 3327 */ 3328 static void 3329 sigparent(struct proc *p, int reason, int status) 3330 { 3331 PROC_LOCK_ASSERT(p, MA_OWNED); 3332 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3333 3334 if (p->p_ksi != NULL) { 3335 p->p_ksi->ksi_signo = SIGCHLD; 3336 p->p_ksi->ksi_code = reason; 3337 p->p_ksi->ksi_status = status; 3338 p->p_ksi->ksi_pid = p->p_pid; 3339 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3340 if (KSI_ONQ(p->p_ksi)) 3341 return; 3342 } 3343 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3344 } 3345 3346 static void 3347 childproc_jobstate(struct proc *p, int reason, int sig) 3348 { 3349 struct sigacts *ps; 3350 3351 PROC_LOCK_ASSERT(p, MA_OWNED); 3352 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3353 3354 /* 3355 * Wake up parent sleeping in kern_wait(), also send 3356 * SIGCHLD to parent, but SIGCHLD does not guarantee 3357 * that parent will awake, because parent may masked 3358 * the signal. 3359 */ 3360 p->p_pptr->p_flag |= P_STATCHILD; 3361 wakeup(p->p_pptr); 3362 3363 ps = p->p_pptr->p_sigacts; 3364 mtx_lock(&ps->ps_mtx); 3365 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3366 mtx_unlock(&ps->ps_mtx); 3367 sigparent(p, reason, sig); 3368 } else 3369 mtx_unlock(&ps->ps_mtx); 3370 } 3371 3372 void 3373 childproc_stopped(struct proc *p, int reason) 3374 { 3375 3376 childproc_jobstate(p, reason, p->p_xsig); 3377 } 3378 3379 void 3380 childproc_continued(struct proc *p) 3381 { 3382 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3383 } 3384 3385 void 3386 childproc_exited(struct proc *p) 3387 { 3388 int reason, status; 3389 3390 if (WCOREDUMP(p->p_xsig)) { 3391 reason = CLD_DUMPED; 3392 status = WTERMSIG(p->p_xsig); 3393 } else if (WIFSIGNALED(p->p_xsig)) { 3394 reason = CLD_KILLED; 3395 status = WTERMSIG(p->p_xsig); 3396 } else { 3397 reason = CLD_EXITED; 3398 status = p->p_xexit; 3399 } 3400 /* 3401 * XXX avoid calling wakeup(p->p_pptr), the work is 3402 * done in exit1(). 3403 */ 3404 sigparent(p, reason, status); 3405 } 3406 3407 #define MAX_NUM_CORE_FILES 100000 3408 #ifndef NUM_CORE_FILES 3409 #define NUM_CORE_FILES 5 3410 #endif 3411 CTASSERT(NUM_CORE_FILES >= 0 && NUM_CORE_FILES <= MAX_NUM_CORE_FILES); 3412 static int num_cores = NUM_CORE_FILES; 3413 3414 static int 3415 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3416 { 3417 int error; 3418 int new_val; 3419 3420 new_val = num_cores; 3421 error = sysctl_handle_int(oidp, &new_val, 0, req); 3422 if (error != 0 || req->newptr == NULL) 3423 return (error); 3424 if (new_val > MAX_NUM_CORE_FILES) 3425 new_val = MAX_NUM_CORE_FILES; 3426 if (new_val < 0) 3427 new_val = 0; 3428 num_cores = new_val; 3429 return (0); 3430 } 3431 SYSCTL_PROC(_debug, OID_AUTO, ncores, 3432 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3433 sysctl_debug_num_cores_check, "I", 3434 "Maximum number of generated process corefiles while using index format"); 3435 3436 #define GZIP_SUFFIX ".gz" 3437 #define ZSTD_SUFFIX ".zst" 3438 3439 int compress_user_cores = 0; 3440 3441 static int 3442 sysctl_compress_user_cores(SYSCTL_HANDLER_ARGS) 3443 { 3444 int error, val; 3445 3446 val = compress_user_cores; 3447 error = sysctl_handle_int(oidp, &val, 0, req); 3448 if (error != 0 || req->newptr == NULL) 3449 return (error); 3450 if (val != 0 && !compressor_avail(val)) 3451 return (EINVAL); 3452 compress_user_cores = val; 3453 return (error); 3454 } 3455 SYSCTL_PROC(_kern, OID_AUTO, compress_user_cores, 3456 CTLTYPE_INT | CTLFLAG_RWTUN | CTLFLAG_NEEDGIANT, 0, sizeof(int), 3457 sysctl_compress_user_cores, "I", 3458 "Enable compression of user corefiles (" 3459 __XSTRING(COMPRESS_GZIP) " = gzip, " 3460 __XSTRING(COMPRESS_ZSTD) " = zstd)"); 3461 3462 int compress_user_cores_level = 6; 3463 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_level, CTLFLAG_RWTUN, 3464 &compress_user_cores_level, 0, 3465 "Corefile compression level"); 3466 3467 /* 3468 * Protect the access to corefilename[] by allproc_lock. 3469 */ 3470 #define corefilename_lock allproc_lock 3471 3472 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3473 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3474 3475 static int 3476 sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3477 { 3478 int error; 3479 3480 sx_xlock(&corefilename_lock); 3481 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3482 req); 3483 sx_xunlock(&corefilename_lock); 3484 3485 return (error); 3486 } 3487 SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3488 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3489 "Process corefile name format string"); 3490 3491 static void 3492 vnode_close_locked(struct thread *td, struct vnode *vp) 3493 { 3494 3495 VOP_UNLOCK(vp); 3496 vn_close(vp, FWRITE, td->td_ucred, td); 3497 } 3498 3499 /* 3500 * If the core format has a %I in it, then we need to check 3501 * for existing corefiles before defining a name. 3502 * To do this we iterate over 0..ncores to find a 3503 * non-existing core file name to use. If all core files are 3504 * already used we choose the oldest one. 3505 */ 3506 static int 3507 corefile_open_last(struct thread *td, char *name, int indexpos, 3508 int indexlen, int ncores, struct vnode **vpp) 3509 { 3510 struct vnode *oldvp, *nextvp, *vp; 3511 struct vattr vattr; 3512 struct nameidata nd; 3513 int error, i, flags, oflags, cmode; 3514 char ch; 3515 struct timespec lasttime; 3516 3517 nextvp = oldvp = NULL; 3518 cmode = S_IRUSR | S_IWUSR; 3519 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3520 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3521 3522 for (i = 0; i < ncores; i++) { 3523 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3524 3525 ch = name[indexpos + indexlen]; 3526 (void)snprintf(name + indexpos, indexlen + 1, "%.*u", indexlen, 3527 i); 3528 name[indexpos + indexlen] = ch; 3529 3530 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3531 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3532 NULL); 3533 if (error != 0) 3534 break; 3535 3536 vp = nd.ni_vp; 3537 NDFREE(&nd, NDF_ONLY_PNBUF); 3538 if ((flags & O_CREAT) == O_CREAT) { 3539 nextvp = vp; 3540 break; 3541 } 3542 3543 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3544 if (error != 0) { 3545 vnode_close_locked(td, vp); 3546 break; 3547 } 3548 3549 if (oldvp == NULL || 3550 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3551 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3552 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3553 if (oldvp != NULL) 3554 vn_close(oldvp, FWRITE, td->td_ucred, td); 3555 oldvp = vp; 3556 VOP_UNLOCK(oldvp); 3557 lasttime = vattr.va_mtime; 3558 } else { 3559 vnode_close_locked(td, vp); 3560 } 3561 } 3562 3563 if (oldvp != NULL) { 3564 if (nextvp == NULL) { 3565 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3566 error = EFAULT; 3567 vn_close(oldvp, FWRITE, td->td_ucred, td); 3568 } else { 3569 nextvp = oldvp; 3570 error = vn_lock(nextvp, LK_EXCLUSIVE); 3571 if (error != 0) { 3572 vn_close(nextvp, FWRITE, td->td_ucred, 3573 td); 3574 nextvp = NULL; 3575 } 3576 } 3577 } else { 3578 vn_close(oldvp, FWRITE, td->td_ucred, td); 3579 } 3580 } 3581 if (error != 0) { 3582 if (nextvp != NULL) 3583 vnode_close_locked(td, oldvp); 3584 } else { 3585 *vpp = nextvp; 3586 } 3587 3588 return (error); 3589 } 3590 3591 /* 3592 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3593 * Expand the name described in corefilename, using name, uid, and pid 3594 * and open/create core file. 3595 * corefilename is a printf-like string, with three format specifiers: 3596 * %N name of process ("name") 3597 * %P process id (pid) 3598 * %U user id (uid) 3599 * For example, "%N.core" is the default; they can be disabled completely 3600 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3601 * This is controlled by the sysctl variable kern.corefile (see above). 3602 */ 3603 static int 3604 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3605 int compress, int signum, struct vnode **vpp, char **namep) 3606 { 3607 struct sbuf sb; 3608 struct nameidata nd; 3609 const char *format; 3610 char *hostname, *name; 3611 int cmode, error, flags, i, indexpos, indexlen, oflags, ncores; 3612 3613 hostname = NULL; 3614 format = corefilename; 3615 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3616 indexlen = 0; 3617 indexpos = -1; 3618 ncores = num_cores; 3619 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3620 sx_slock(&corefilename_lock); 3621 for (i = 0; format[i] != '\0'; i++) { 3622 switch (format[i]) { 3623 case '%': /* Format character */ 3624 i++; 3625 switch (format[i]) { 3626 case '%': 3627 sbuf_putc(&sb, '%'); 3628 break; 3629 case 'H': /* hostname */ 3630 if (hostname == NULL) { 3631 hostname = malloc(MAXHOSTNAMELEN, 3632 M_TEMP, M_WAITOK); 3633 } 3634 getcredhostname(td->td_ucred, hostname, 3635 MAXHOSTNAMELEN); 3636 sbuf_printf(&sb, "%s", hostname); 3637 break; 3638 case 'I': /* autoincrementing index */ 3639 if (indexpos != -1) { 3640 sbuf_printf(&sb, "%%I"); 3641 break; 3642 } 3643 3644 indexpos = sbuf_len(&sb); 3645 sbuf_printf(&sb, "%u", ncores - 1); 3646 indexlen = sbuf_len(&sb) - indexpos; 3647 break; 3648 case 'N': /* process name */ 3649 sbuf_printf(&sb, "%s", comm); 3650 break; 3651 case 'P': /* process id */ 3652 sbuf_printf(&sb, "%u", pid); 3653 break; 3654 case 'S': /* signal number */ 3655 sbuf_printf(&sb, "%i", signum); 3656 break; 3657 case 'U': /* user id */ 3658 sbuf_printf(&sb, "%u", uid); 3659 break; 3660 default: 3661 log(LOG_ERR, 3662 "Unknown format character %c in " 3663 "corename `%s'\n", format[i], format); 3664 break; 3665 } 3666 break; 3667 default: 3668 sbuf_putc(&sb, format[i]); 3669 break; 3670 } 3671 } 3672 sx_sunlock(&corefilename_lock); 3673 free(hostname, M_TEMP); 3674 if (compress == COMPRESS_GZIP) 3675 sbuf_printf(&sb, GZIP_SUFFIX); 3676 else if (compress == COMPRESS_ZSTD) 3677 sbuf_printf(&sb, ZSTD_SUFFIX); 3678 if (sbuf_error(&sb) != 0) { 3679 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3680 "long\n", (long)pid, comm, (u_long)uid); 3681 sbuf_delete(&sb); 3682 free(name, M_TEMP); 3683 return (ENOMEM); 3684 } 3685 sbuf_finish(&sb); 3686 sbuf_delete(&sb); 3687 3688 if (indexpos != -1) { 3689 error = corefile_open_last(td, name, indexpos, indexlen, ncores, 3690 vpp); 3691 if (error != 0) { 3692 log(LOG_ERR, 3693 "pid %d (%s), uid (%u): Path `%s' failed " 3694 "on initial open test, error = %d\n", 3695 pid, comm, uid, name, error); 3696 } 3697 } else { 3698 cmode = S_IRUSR | S_IWUSR; 3699 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3700 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3701 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3702 if ((td->td_proc->p_flag & P_SUGID) != 0) 3703 flags |= O_EXCL; 3704 3705 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3706 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3707 NULL); 3708 if (error == 0) { 3709 *vpp = nd.ni_vp; 3710 NDFREE(&nd, NDF_ONLY_PNBUF); 3711 } 3712 } 3713 3714 if (error != 0) { 3715 #ifdef AUDIT 3716 audit_proc_coredump(td, name, error); 3717 #endif 3718 free(name, M_TEMP); 3719 return (error); 3720 } 3721 *namep = name; 3722 return (0); 3723 } 3724 3725 /* 3726 * Dump a process' core. The main routine does some 3727 * policy checking, and creates the name of the coredump; 3728 * then it passes on a vnode and a size limit to the process-specific 3729 * coredump routine if there is one; if there _is not_ one, it returns 3730 * ENOSYS; otherwise it returns the error from the process-specific routine. 3731 */ 3732 3733 static int 3734 coredump(struct thread *td) 3735 { 3736 struct proc *p = td->td_proc; 3737 struct ucred *cred = td->td_ucred; 3738 struct vnode *vp; 3739 struct flock lf; 3740 struct vattr vattr; 3741 size_t fullpathsize; 3742 int error, error1, locked; 3743 char *name; /* name of corefile */ 3744 void *rl_cookie; 3745 off_t limit; 3746 char *fullpath, *freepath = NULL; 3747 struct sbuf *sb; 3748 3749 PROC_LOCK_ASSERT(p, MA_OWNED); 3750 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3751 3752 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3753 (p->p_flag2 & P2_NOTRACE) != 0) { 3754 PROC_UNLOCK(p); 3755 return (EFAULT); 3756 } 3757 3758 /* 3759 * Note that the bulk of limit checking is done after 3760 * the corefile is created. The exception is if the limit 3761 * for corefiles is 0, in which case we don't bother 3762 * creating the corefile at all. This layout means that 3763 * a corefile is truncated instead of not being created, 3764 * if it is larger than the limit. 3765 */ 3766 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3767 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3768 PROC_UNLOCK(p); 3769 return (EFBIG); 3770 } 3771 PROC_UNLOCK(p); 3772 3773 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3774 compress_user_cores, p->p_sig, &vp, &name); 3775 if (error != 0) 3776 return (error); 3777 3778 /* 3779 * Don't dump to non-regular files or files with links. 3780 * Do not dump into system files. Effective user must own the corefile. 3781 */ 3782 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3783 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3784 vattr.va_uid != cred->cr_uid) { 3785 VOP_UNLOCK(vp); 3786 error = EFAULT; 3787 goto out; 3788 } 3789 3790 VOP_UNLOCK(vp); 3791 3792 /* Postpone other writers, including core dumps of other processes. */ 3793 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3794 3795 lf.l_whence = SEEK_SET; 3796 lf.l_start = 0; 3797 lf.l_len = 0; 3798 lf.l_type = F_WRLCK; 3799 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3800 3801 VATTR_NULL(&vattr); 3802 vattr.va_size = 0; 3803 if (set_core_nodump_flag) 3804 vattr.va_flags = UF_NODUMP; 3805 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3806 VOP_SETATTR(vp, &vattr, cred); 3807 VOP_UNLOCK(vp); 3808 PROC_LOCK(p); 3809 p->p_acflag |= ACORE; 3810 PROC_UNLOCK(p); 3811 3812 if (p->p_sysent->sv_coredump != NULL) { 3813 error = p->p_sysent->sv_coredump(td, vp, limit, 0); 3814 } else { 3815 error = ENOSYS; 3816 } 3817 3818 if (locked) { 3819 lf.l_type = F_UNLCK; 3820 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3821 } 3822 vn_rangelock_unlock(vp, rl_cookie); 3823 3824 /* 3825 * Notify the userland helper that a process triggered a core dump. 3826 * This allows the helper to run an automated debugging session. 3827 */ 3828 if (error != 0 || coredump_devctl == 0) 3829 goto out; 3830 sb = sbuf_new_auto(); 3831 if (vn_fullpath_global(p->p_textvp, &fullpath, &freepath) != 0) 3832 goto out2; 3833 sbuf_printf(sb, "comm=\""); 3834 devctl_safe_quote_sb(sb, fullpath); 3835 free(freepath, M_TEMP); 3836 sbuf_printf(sb, "\" core=\""); 3837 3838 /* 3839 * We can't lookup core file vp directly. When we're replacing a core, and 3840 * other random times, we flush the name cache, so it will fail. Instead, 3841 * if the path of the core is relative, add the current dir in front if it. 3842 */ 3843 if (name[0] != '/') { 3844 fullpathsize = MAXPATHLEN; 3845 freepath = malloc(fullpathsize, M_TEMP, M_WAITOK); 3846 if (vn_getcwd(freepath, &fullpath, &fullpathsize) != 0) { 3847 free(freepath, M_TEMP); 3848 goto out2; 3849 } 3850 devctl_safe_quote_sb(sb, fullpath); 3851 free(freepath, M_TEMP); 3852 sbuf_putc(sb, '/'); 3853 } 3854 devctl_safe_quote_sb(sb, name); 3855 sbuf_printf(sb, "\""); 3856 if (sbuf_finish(sb) == 0) 3857 devctl_notify("kernel", "signal", "coredump", sbuf_data(sb)); 3858 out2: 3859 sbuf_delete(sb); 3860 out: 3861 error1 = vn_close(vp, FWRITE, cred, td); 3862 if (error == 0) 3863 error = error1; 3864 #ifdef AUDIT 3865 audit_proc_coredump(td, name, error); 3866 #endif 3867 free(name, M_TEMP); 3868 return (error); 3869 } 3870 3871 /* 3872 * Nonexistent system call-- signal process (may want to handle it). Flag 3873 * error in case process won't see signal immediately (blocked or ignored). 3874 */ 3875 #ifndef _SYS_SYSPROTO_H_ 3876 struct nosys_args { 3877 int dummy; 3878 }; 3879 #endif 3880 /* ARGSUSED */ 3881 int 3882 nosys(struct thread *td, struct nosys_args *args) 3883 { 3884 struct proc *p; 3885 3886 p = td->td_proc; 3887 3888 PROC_LOCK(p); 3889 tdsignal(td, SIGSYS); 3890 PROC_UNLOCK(p); 3891 if (kern_lognosys == 1 || kern_lognosys == 3) { 3892 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3893 td->td_sa.code); 3894 } 3895 if (kern_lognosys == 2 || kern_lognosys == 3 || 3896 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 3897 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3898 td->td_sa.code); 3899 } 3900 return (ENOSYS); 3901 } 3902 3903 /* 3904 * Send a SIGIO or SIGURG signal to a process or process group using stored 3905 * credentials rather than those of the current process. 3906 */ 3907 void 3908 pgsigio(struct sigio **sigiop, int sig, int checkctty) 3909 { 3910 ksiginfo_t ksi; 3911 struct sigio *sigio; 3912 3913 ksiginfo_init(&ksi); 3914 ksi.ksi_signo = sig; 3915 ksi.ksi_code = SI_KERNEL; 3916 3917 SIGIO_LOCK(); 3918 sigio = *sigiop; 3919 if (sigio == NULL) { 3920 SIGIO_UNLOCK(); 3921 return; 3922 } 3923 if (sigio->sio_pgid > 0) { 3924 PROC_LOCK(sigio->sio_proc); 3925 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3926 kern_psignal(sigio->sio_proc, sig); 3927 PROC_UNLOCK(sigio->sio_proc); 3928 } else if (sigio->sio_pgid < 0) { 3929 struct proc *p; 3930 3931 PGRP_LOCK(sigio->sio_pgrp); 3932 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3933 PROC_LOCK(p); 3934 if (p->p_state == PRS_NORMAL && 3935 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3936 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3937 kern_psignal(p, sig); 3938 PROC_UNLOCK(p); 3939 } 3940 PGRP_UNLOCK(sigio->sio_pgrp); 3941 } 3942 SIGIO_UNLOCK(); 3943 } 3944 3945 static int 3946 filt_sigattach(struct knote *kn) 3947 { 3948 struct proc *p = curproc; 3949 3950 kn->kn_ptr.p_proc = p; 3951 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3952 3953 knlist_add(p->p_klist, kn, 0); 3954 3955 return (0); 3956 } 3957 3958 static void 3959 filt_sigdetach(struct knote *kn) 3960 { 3961 struct proc *p = kn->kn_ptr.p_proc; 3962 3963 knlist_remove(p->p_klist, kn, 0); 3964 } 3965 3966 /* 3967 * signal knotes are shared with proc knotes, so we apply a mask to 3968 * the hint in order to differentiate them from process hints. This 3969 * could be avoided by using a signal-specific knote list, but probably 3970 * isn't worth the trouble. 3971 */ 3972 static int 3973 filt_signal(struct knote *kn, long hint) 3974 { 3975 3976 if (hint & NOTE_SIGNAL) { 3977 hint &= ~NOTE_SIGNAL; 3978 3979 if (kn->kn_id == hint) 3980 kn->kn_data++; 3981 } 3982 return (kn->kn_data != 0); 3983 } 3984 3985 struct sigacts * 3986 sigacts_alloc(void) 3987 { 3988 struct sigacts *ps; 3989 3990 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3991 refcount_init(&ps->ps_refcnt, 1); 3992 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3993 return (ps); 3994 } 3995 3996 void 3997 sigacts_free(struct sigacts *ps) 3998 { 3999 4000 if (refcount_release(&ps->ps_refcnt) == 0) 4001 return; 4002 mtx_destroy(&ps->ps_mtx); 4003 free(ps, M_SUBPROC); 4004 } 4005 4006 struct sigacts * 4007 sigacts_hold(struct sigacts *ps) 4008 { 4009 4010 refcount_acquire(&ps->ps_refcnt); 4011 return (ps); 4012 } 4013 4014 void 4015 sigacts_copy(struct sigacts *dest, struct sigacts *src) 4016 { 4017 4018 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 4019 mtx_lock(&src->ps_mtx); 4020 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 4021 mtx_unlock(&src->ps_mtx); 4022 } 4023 4024 int 4025 sigacts_shared(struct sigacts *ps) 4026 { 4027 4028 return (ps->ps_refcnt > 1); 4029 } 4030 4031 void 4032 sig_drop_caught(struct proc *p) 4033 { 4034 int sig; 4035 struct sigacts *ps; 4036 4037 ps = p->p_sigacts; 4038 PROC_LOCK_ASSERT(p, MA_OWNED); 4039 mtx_assert(&ps->ps_mtx, MA_OWNED); 4040 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 4041 sig = sig_ffs(&ps->ps_sigcatch); 4042 sigdflt(ps, sig); 4043 if ((sigprop(sig) & SIGPROP_IGNORE) != 0) 4044 sigqueue_delete_proc(p, sig); 4045 } 4046 } 4047 4048 static void 4049 sigfastblock_failed(struct thread *td, bool sendsig, bool write) 4050 { 4051 ksiginfo_t ksi; 4052 4053 /* 4054 * Prevent further fetches and SIGSEGVs, allowing thread to 4055 * issue syscalls despite corruption. 4056 */ 4057 sigfastblock_clear(td); 4058 4059 if (!sendsig) 4060 return; 4061 ksiginfo_init_trap(&ksi); 4062 ksi.ksi_signo = SIGSEGV; 4063 ksi.ksi_code = write ? SEGV_ACCERR : SEGV_MAPERR; 4064 ksi.ksi_addr = td->td_sigblock_ptr; 4065 trapsignal(td, &ksi); 4066 } 4067 4068 static bool 4069 sigfastblock_fetch_sig(struct thread *td, bool sendsig, uint32_t *valp) 4070 { 4071 uint32_t res; 4072 4073 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4074 return (true); 4075 if (fueword32((void *)td->td_sigblock_ptr, &res) == -1) { 4076 sigfastblock_failed(td, sendsig, false); 4077 return (false); 4078 } 4079 *valp = res; 4080 td->td_sigblock_val = res & ~SIGFASTBLOCK_FLAGS; 4081 return (true); 4082 } 4083 4084 static void 4085 sigfastblock_resched(struct thread *td, bool resched) 4086 { 4087 struct proc *p; 4088 4089 if (resched) { 4090 p = td->td_proc; 4091 PROC_LOCK(p); 4092 reschedule_signals(p, td->td_sigmask, 0); 4093 PROC_UNLOCK(p); 4094 } 4095 thread_lock(td); 4096 td->td_flags |= TDF_ASTPENDING | TDF_NEEDSIGCHK; 4097 thread_unlock(td); 4098 } 4099 4100 int 4101 sys_sigfastblock(struct thread *td, struct sigfastblock_args *uap) 4102 { 4103 struct proc *p; 4104 int error, res; 4105 uint32_t oldval; 4106 4107 error = 0; 4108 p = td->td_proc; 4109 switch (uap->cmd) { 4110 case SIGFASTBLOCK_SETPTR: 4111 if ((td->td_pflags & TDP_SIGFASTBLOCK) != 0) { 4112 error = EBUSY; 4113 break; 4114 } 4115 if (((uintptr_t)(uap->ptr) & (sizeof(uint32_t) - 1)) != 0) { 4116 error = EINVAL; 4117 break; 4118 } 4119 td->td_pflags |= TDP_SIGFASTBLOCK; 4120 td->td_sigblock_ptr = uap->ptr; 4121 break; 4122 4123 case SIGFASTBLOCK_UNBLOCK: 4124 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4125 error = EINVAL; 4126 break; 4127 } 4128 4129 for (;;) { 4130 res = casueword32(td->td_sigblock_ptr, 4131 SIGFASTBLOCK_PEND, &oldval, 0); 4132 if (res == -1) { 4133 error = EFAULT; 4134 sigfastblock_failed(td, false, true); 4135 break; 4136 } 4137 if (res == 0) 4138 break; 4139 MPASS(res == 1); 4140 if (oldval != SIGFASTBLOCK_PEND) { 4141 error = EBUSY; 4142 break; 4143 } 4144 error = thread_check_susp(td, false); 4145 if (error != 0) 4146 break; 4147 } 4148 if (error != 0) 4149 break; 4150 4151 /* 4152 * td_sigblock_val is cleared there, but not on a 4153 * syscall exit. The end effect is that a single 4154 * interruptible sleep, while user sigblock word is 4155 * set, might return EINTR or ERESTART to usermode 4156 * without delivering signal. All further sleeps, 4157 * until userspace clears the word and does 4158 * sigfastblock(UNBLOCK), observe current word and no 4159 * longer get interrupted. It is slight 4160 * non-conformance, with alternative to have read the 4161 * sigblock word on each syscall entry. 4162 */ 4163 td->td_sigblock_val = 0; 4164 4165 /* 4166 * Rely on normal ast mechanism to deliver pending 4167 * signals to current thread. But notify others about 4168 * fake unblock. 4169 */ 4170 sigfastblock_resched(td, error == 0 && p->p_numthreads != 1); 4171 4172 break; 4173 4174 case SIGFASTBLOCK_UNSETPTR: 4175 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) { 4176 error = EINVAL; 4177 break; 4178 } 4179 if (!sigfastblock_fetch_sig(td, false, &oldval)) { 4180 error = EFAULT; 4181 break; 4182 } 4183 if (oldval != 0 && oldval != SIGFASTBLOCK_PEND) { 4184 error = EBUSY; 4185 break; 4186 } 4187 sigfastblock_clear(td); 4188 break; 4189 4190 default: 4191 error = EINVAL; 4192 break; 4193 } 4194 return (error); 4195 } 4196 4197 void 4198 sigfastblock_clear(struct thread *td) 4199 { 4200 bool resched; 4201 4202 if ((td->td_pflags & TDP_SIGFASTBLOCK) == 0) 4203 return; 4204 td->td_sigblock_val = 0; 4205 resched = (td->td_pflags & TDP_SIGFASTPENDING) != 0 || 4206 SIGPENDING(td); 4207 td->td_pflags &= ~(TDP_SIGFASTBLOCK | TDP_SIGFASTPENDING); 4208 sigfastblock_resched(td, resched); 4209 } 4210 4211 void 4212 sigfastblock_fetch(struct thread *td) 4213 { 4214 uint32_t val; 4215 4216 (void)sigfastblock_fetch_sig(td, true, &val); 4217 } 4218 4219 static void 4220 sigfastblock_setpend1(struct thread *td) 4221 { 4222 int res; 4223 uint32_t oldval; 4224 4225 if ((td->td_pflags & TDP_SIGFASTPENDING) == 0) 4226 return; 4227 res = fueword32((void *)td->td_sigblock_ptr, &oldval); 4228 if (res == -1) { 4229 sigfastblock_failed(td, true, false); 4230 return; 4231 } 4232 for (;;) { 4233 res = casueword32(td->td_sigblock_ptr, oldval, &oldval, 4234 oldval | SIGFASTBLOCK_PEND); 4235 if (res == -1) { 4236 sigfastblock_failed(td, true, true); 4237 return; 4238 } 4239 if (res == 0) { 4240 td->td_sigblock_val = oldval & ~SIGFASTBLOCK_FLAGS; 4241 td->td_pflags &= ~TDP_SIGFASTPENDING; 4242 break; 4243 } 4244 MPASS(res == 1); 4245 if (thread_check_susp(td, false) != 0) 4246 break; 4247 } 4248 } 4249 4250 void 4251 sigfastblock_setpend(struct thread *td, bool resched) 4252 { 4253 struct proc *p; 4254 4255 sigfastblock_setpend1(td); 4256 if (resched) { 4257 p = td->td_proc; 4258 PROC_LOCK(p); 4259 reschedule_signals(p, fastblock_mask, SIGPROCMASK_FASTBLK); 4260 PROC_UNLOCK(p); 4261 } 4262 } 4263