Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
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1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD: releng/10.4/sys/kern/kern_sig.c 322848 2017-08-24 17:25:16Z will $"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 #include "opt_core.h" 44 #include "opt_procdesc.h" 45 46 #include <sys/param.h> 47 #include <sys/ctype.h> 48 #include <sys/systm.h> 49 #include <sys/signalvar.h> 50 #include <sys/vnode.h> 51 #include <sys/acct.h> 52 #include <sys/bus.h> 53 #include <sys/capsicum.h> 54 #include <sys/condvar.h> 55 #include <sys/event.h> 56 #include <sys/fcntl.h> 57 #include <sys/imgact.h> 58 #include <sys/kernel.h> 59 #include <sys/ktr.h> 60 #include <sys/ktrace.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/posix4.h> 69 #include <sys/pioctl.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 int sigprop(int sig); 111 static void tdsigwakeup(struct thread *, int, sig_t, int); 112 static void sig_suspend_threads(struct thread *, struct proc *, int); 113 static int filt_sigattach(struct knote *kn); 114 static void filt_sigdetach(struct knote *kn); 115 static int filt_signal(struct knote *kn, long hint); 116 static struct thread *sigtd(struct proc *p, int sig, int prop); 117 static void sigqueue_start(void); 118 119 static uma_zone_t ksiginfo_zone = NULL; 120 struct filterops sig_filtops = { 121 .f_isfd = 0, 122 .f_attach = filt_sigattach, 123 .f_detach = filt_sigdetach, 124 .f_event = filt_signal, 125 }; 126 127 static int kern_logsigexit = 1; 128 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 129 &kern_logsigexit, 0, 130 "Log processes quitting on abnormal signals to syslog(3)"); 131 132 static int kern_forcesigexit = 1; 133 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 134 &kern_forcesigexit, 0, "Force trap signal to be handled"); 135 136 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 137 "POSIX real time signal"); 138 139 static int max_pending_per_proc = 128; 140 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 141 &max_pending_per_proc, 0, "Max pending signals per proc"); 142 143 static int preallocate_siginfo = 1024; 144 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 145 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 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 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 157 158 /* 159 * Policy -- Can ucred cr1 send SIGIO to process cr2? 160 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 161 * in the right situations. 162 */ 163 #define CANSIGIO(cr1, cr2) \ 164 ((cr1)->cr_uid == 0 || \ 165 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 166 (cr1)->cr_uid == (cr2)->cr_ruid || \ 167 (cr1)->cr_ruid == (cr2)->cr_uid || \ 168 (cr1)->cr_uid == (cr2)->cr_uid) 169 170 static int sugid_coredump; 171 TUNABLE_INT("kern.sugid_coredump", &sugid_coredump); 172 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 173 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 174 175 static int capmode_coredump; 176 TUNABLE_INT("kern.capmode_coredump", &capmode_coredump); 177 SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180 static int do_coredump = 1; 181 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184 static int set_core_nodump_flag = 0; 185 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188 static int coredump_devctl = 0; 189 SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192 /* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197 #define SA_KILL 0x01 /* terminates process by default */ 198 #define SA_CORE 0x02 /* ditto and coredumps */ 199 #define SA_STOP 0x04 /* suspend process */ 200 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 201 #define SA_IGNORE 0x10 /* ignore by default */ 202 #define SA_CONT 0x20 /* continue if suspended */ 203 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 204 205 static int sigproptbl[NSIG] = { 206 SA_KILL, /* SIGHUP */ 207 SA_KILL, /* SIGINT */ 208 SA_KILL|SA_CORE, /* SIGQUIT */ 209 SA_KILL|SA_CORE, /* SIGILL */ 210 SA_KILL|SA_CORE, /* SIGTRAP */ 211 SA_KILL|SA_CORE, /* SIGABRT */ 212 SA_KILL|SA_CORE, /* SIGEMT */ 213 SA_KILL|SA_CORE, /* SIGFPE */ 214 SA_KILL, /* SIGKILL */ 215 SA_KILL|SA_CORE, /* SIGBUS */ 216 SA_KILL|SA_CORE, /* SIGSEGV */ 217 SA_KILL|SA_CORE, /* SIGSYS */ 218 SA_KILL, /* SIGPIPE */ 219 SA_KILL, /* SIGALRM */ 220 SA_KILL, /* SIGTERM */ 221 SA_IGNORE, /* SIGURG */ 222 SA_STOP, /* SIGSTOP */ 223 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 224 SA_IGNORE|SA_CONT, /* SIGCONT */ 225 SA_IGNORE, /* SIGCHLD */ 226 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 227 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 228 SA_IGNORE, /* SIGIO */ 229 SA_KILL, /* SIGXCPU */ 230 SA_KILL, /* SIGXFSZ */ 231 SA_KILL, /* SIGVTALRM */ 232 SA_KILL, /* SIGPROF */ 233 SA_IGNORE, /* SIGWINCH */ 234 SA_IGNORE, /* SIGINFO */ 235 SA_KILL, /* SIGUSR1 */ 236 SA_KILL, /* SIGUSR2 */ 237 }; 238 239 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241 static void 242 sigqueue_start(void) 243 { 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250 } 251 252 ksiginfo_t * 253 ksiginfo_alloc(int wait) 254 { 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263 } 264 265 void 266 ksiginfo_free(ksiginfo_t *ksi) 267 { 268 uma_zfree(ksiginfo_zone, ksi); 269 } 270 271 static __inline int 272 ksiginfo_tryfree(ksiginfo_t *ksi) 273 { 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279 } 280 281 void 282 sigqueue_init(sigqueue_t *list, struct proc *p) 283 { 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290 } 291 292 /* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298 static int 299 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300 { 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339 } 340 341 void 342 sigqueue_take(ksiginfo_t *ksi) 343 { 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365 } 366 367 static int 368 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369 { 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432 out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435 } 436 437 void 438 sigqueue_flush(sigqueue_t *sq) 439 { 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458 } 459 460 static void 461 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462 { 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499 } 500 501 #if 0 502 static void 503 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504 { 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510 } 511 #endif 512 513 static void 514 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515 { 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533 } 534 535 void 536 sigqueue_delete(sigqueue_t *sq, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543 } 544 545 /* Remove a set of signals for a process */ 546 static void 547 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548 { 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561 } 562 563 void 564 sigqueue_delete_proc(struct proc *p, int signo) 565 { 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571 } 572 573 static void 574 sigqueue_delete_stopmask_proc(struct proc *p) 575 { 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584 } 585 586 /* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591 int 592 cursig(struct thread *td) 593 { 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598 } 599 600 /* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605 void 606 signotify(struct thread *td) 607 { 608 struct proc *p; 609 610 p = td->td_proc; 611 612 PROC_LOCK_ASSERT(p, MA_OWNED); 613 614 if (SIGPENDING(td)) { 615 thread_lock(td); 616 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 617 thread_unlock(td); 618 } 619 } 620 621 int 622 sigonstack(size_t sp) 623 { 624 struct thread *td = curthread; 625 626 return ((td->td_pflags & TDP_ALTSTACK) ? 627 #if defined(COMPAT_43) 628 ((td->td_sigstk.ss_size == 0) ? 629 (td->td_sigstk.ss_flags & SS_ONSTACK) : 630 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 631 #else 632 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 633 #endif 634 : 0); 635 } 636 637 static __inline int 638 sigprop(int sig) 639 { 640 641 if (sig > 0 && sig < NSIG) 642 return (sigproptbl[_SIG_IDX(sig)]); 643 return (0); 644 } 645 646 int 647 sig_ffs(sigset_t *set) 648 { 649 int i; 650 651 for (i = 0; i < _SIG_WORDS; i++) 652 if (set->__bits[i]) 653 return (ffs(set->__bits[i]) + (i * 32)); 654 return (0); 655 } 656 657 static bool 658 sigact_flag_test(struct sigaction *act, int flag) 659 { 660 661 /* 662 * SA_SIGINFO is reset when signal disposition is set to 663 * ignore or default. Other flags are kept according to user 664 * settings. 665 */ 666 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 667 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 668 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 669 } 670 671 /* 672 * kern_sigaction 673 * sigaction 674 * freebsd4_sigaction 675 * osigaction 676 */ 677 int 678 kern_sigaction(td, sig, act, oact, flags) 679 struct thread *td; 680 register int sig; 681 struct sigaction *act, *oact; 682 int flags; 683 { 684 struct sigacts *ps; 685 struct proc *p = td->td_proc; 686 687 if (!_SIG_VALID(sig)) 688 return (EINVAL); 689 if (act != NULL && act->sa_handler != SIG_DFL && 690 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 691 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 692 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 693 return (EINVAL); 694 695 PROC_LOCK(p); 696 ps = p->p_sigacts; 697 mtx_lock(&ps->ps_mtx); 698 if (oact) { 699 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 700 oact->sa_flags = 0; 701 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 702 oact->sa_flags |= SA_ONSTACK; 703 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 704 oact->sa_flags |= SA_RESTART; 705 if (SIGISMEMBER(ps->ps_sigreset, sig)) 706 oact->sa_flags |= SA_RESETHAND; 707 if (SIGISMEMBER(ps->ps_signodefer, sig)) 708 oact->sa_flags |= SA_NODEFER; 709 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 710 oact->sa_flags |= SA_SIGINFO; 711 oact->sa_sigaction = 712 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 713 } else 714 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 715 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 716 oact->sa_flags |= SA_NOCLDSTOP; 717 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 718 oact->sa_flags |= SA_NOCLDWAIT; 719 } 720 if (act) { 721 if ((sig == SIGKILL || sig == SIGSTOP) && 722 act->sa_handler != SIG_DFL) { 723 mtx_unlock(&ps->ps_mtx); 724 PROC_UNLOCK(p); 725 return (EINVAL); 726 } 727 728 /* 729 * Change setting atomically. 730 */ 731 732 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 733 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 734 if (sigact_flag_test(act, SA_SIGINFO)) { 735 ps->ps_sigact[_SIG_IDX(sig)] = 736 (__sighandler_t *)act->sa_sigaction; 737 SIGADDSET(ps->ps_siginfo, sig); 738 } else { 739 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 740 SIGDELSET(ps->ps_siginfo, sig); 741 } 742 if (!sigact_flag_test(act, SA_RESTART)) 743 SIGADDSET(ps->ps_sigintr, sig); 744 else 745 SIGDELSET(ps->ps_sigintr, sig); 746 if (sigact_flag_test(act, SA_ONSTACK)) 747 SIGADDSET(ps->ps_sigonstack, sig); 748 else 749 SIGDELSET(ps->ps_sigonstack, sig); 750 if (sigact_flag_test(act, SA_RESETHAND)) 751 SIGADDSET(ps->ps_sigreset, sig); 752 else 753 SIGDELSET(ps->ps_sigreset, sig); 754 if (sigact_flag_test(act, SA_NODEFER)) 755 SIGADDSET(ps->ps_signodefer, sig); 756 else 757 SIGDELSET(ps->ps_signodefer, sig); 758 if (sig == SIGCHLD) { 759 if (act->sa_flags & SA_NOCLDSTOP) 760 ps->ps_flag |= PS_NOCLDSTOP; 761 else 762 ps->ps_flag &= ~PS_NOCLDSTOP; 763 if (act->sa_flags & SA_NOCLDWAIT) { 764 /* 765 * Paranoia: since SA_NOCLDWAIT is implemented 766 * by reparenting the dying child to PID 1 (and 767 * trust it to reap the zombie), PID 1 itself 768 * is forbidden to set SA_NOCLDWAIT. 769 */ 770 if (p->p_pid == 1) 771 ps->ps_flag &= ~PS_NOCLDWAIT; 772 else 773 ps->ps_flag |= PS_NOCLDWAIT; 774 } else 775 ps->ps_flag &= ~PS_NOCLDWAIT; 776 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 777 ps->ps_flag |= PS_CLDSIGIGN; 778 else 779 ps->ps_flag &= ~PS_CLDSIGIGN; 780 } 781 /* 782 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 783 * and for signals set to SIG_DFL where the default is to 784 * ignore. However, don't put SIGCONT in ps_sigignore, as we 785 * have to restart the process. 786 */ 787 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 788 (sigprop(sig) & SA_IGNORE && 789 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 790 /* never to be seen again */ 791 sigqueue_delete_proc(p, sig); 792 if (sig != SIGCONT) 793 /* easier in psignal */ 794 SIGADDSET(ps->ps_sigignore, sig); 795 SIGDELSET(ps->ps_sigcatch, sig); 796 } else { 797 SIGDELSET(ps->ps_sigignore, sig); 798 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 799 SIGDELSET(ps->ps_sigcatch, sig); 800 else 801 SIGADDSET(ps->ps_sigcatch, sig); 802 } 803 #ifdef COMPAT_FREEBSD4 804 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 805 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 806 (flags & KSA_FREEBSD4) == 0) 807 SIGDELSET(ps->ps_freebsd4, sig); 808 else 809 SIGADDSET(ps->ps_freebsd4, sig); 810 #endif 811 #ifdef COMPAT_43 812 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 813 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 814 (flags & KSA_OSIGSET) == 0) 815 SIGDELSET(ps->ps_osigset, sig); 816 else 817 SIGADDSET(ps->ps_osigset, sig); 818 #endif 819 } 820 mtx_unlock(&ps->ps_mtx); 821 PROC_UNLOCK(p); 822 return (0); 823 } 824 825 #ifndef _SYS_SYSPROTO_H_ 826 struct sigaction_args { 827 int sig; 828 struct sigaction *act; 829 struct sigaction *oact; 830 }; 831 #endif 832 int 833 sys_sigaction(td, uap) 834 struct thread *td; 835 register struct sigaction_args *uap; 836 { 837 struct sigaction act, oact; 838 register struct sigaction *actp, *oactp; 839 int error; 840 841 actp = (uap->act != NULL) ? &act : NULL; 842 oactp = (uap->oact != NULL) ? &oact : NULL; 843 if (actp) { 844 error = copyin(uap->act, actp, sizeof(act)); 845 if (error) 846 return (error); 847 } 848 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 849 if (oactp && !error) 850 error = copyout(oactp, uap->oact, sizeof(oact)); 851 return (error); 852 } 853 854 #ifdef COMPAT_FREEBSD4 855 #ifndef _SYS_SYSPROTO_H_ 856 struct freebsd4_sigaction_args { 857 int sig; 858 struct sigaction *act; 859 struct sigaction *oact; 860 }; 861 #endif 862 int 863 freebsd4_sigaction(td, uap) 864 struct thread *td; 865 register struct freebsd4_sigaction_args *uap; 866 { 867 struct sigaction act, oact; 868 register struct sigaction *actp, *oactp; 869 int error; 870 871 872 actp = (uap->act != NULL) ? &act : NULL; 873 oactp = (uap->oact != NULL) ? &oact : NULL; 874 if (actp) { 875 error = copyin(uap->act, actp, sizeof(act)); 876 if (error) 877 return (error); 878 } 879 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 880 if (oactp && !error) 881 error = copyout(oactp, uap->oact, sizeof(oact)); 882 return (error); 883 } 884 #endif /* COMAPT_FREEBSD4 */ 885 886 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 887 #ifndef _SYS_SYSPROTO_H_ 888 struct osigaction_args { 889 int signum; 890 struct osigaction *nsa; 891 struct osigaction *osa; 892 }; 893 #endif 894 int 895 osigaction(td, uap) 896 struct thread *td; 897 register struct osigaction_args *uap; 898 { 899 struct osigaction sa; 900 struct sigaction nsa, osa; 901 register struct sigaction *nsap, *osap; 902 int error; 903 904 if (uap->signum <= 0 || uap->signum >= ONSIG) 905 return (EINVAL); 906 907 nsap = (uap->nsa != NULL) ? &nsa : NULL; 908 osap = (uap->osa != NULL) ? &osa : NULL; 909 910 if (nsap) { 911 error = copyin(uap->nsa, &sa, sizeof(sa)); 912 if (error) 913 return (error); 914 nsap->sa_handler = sa.sa_handler; 915 nsap->sa_flags = sa.sa_flags; 916 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 917 } 918 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 919 if (osap && !error) { 920 sa.sa_handler = osap->sa_handler; 921 sa.sa_flags = osap->sa_flags; 922 SIG2OSIG(osap->sa_mask, sa.sa_mask); 923 error = copyout(&sa, uap->osa, sizeof(sa)); 924 } 925 return (error); 926 } 927 928 #if !defined(__i386__) 929 /* Avoid replicating the same stub everywhere */ 930 int 931 osigreturn(td, uap) 932 struct thread *td; 933 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(p) 947 struct proc *p; 948 { 949 register int i; 950 struct sigacts *ps; 951 952 PROC_LOCK(p); 953 ps = p->p_sigacts; 954 mtx_lock(&ps->ps_mtx); 955 for (i = 1; i <= NSIG; i++) { 956 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 957 SIGADDSET(ps->ps_sigignore, i); 958 } 959 } 960 mtx_unlock(&ps->ps_mtx); 961 PROC_UNLOCK(p); 962 } 963 964 /* 965 * Reset specified signal to the default disposition. 966 */ 967 static void 968 sigdflt(struct sigacts *ps, int sig) 969 { 970 971 mtx_assert(&ps->ps_mtx, MA_OWNED); 972 SIGDELSET(ps->ps_sigcatch, sig); 973 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 974 SIGADDSET(ps->ps_sigignore, sig); 975 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 976 SIGDELSET(ps->ps_siginfo, sig); 977 } 978 979 /* 980 * Reset signals for an exec of the specified process. 981 */ 982 void 983 execsigs(struct proc *p) 984 { 985 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 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 998 sig = sig_ffs(&ps->ps_sigcatch); 999 sigdflt(ps, sig); 1000 if ((sigprop(sig) & SA_IGNORE) != 0) 1001 sigqueue_delete_proc(p, sig); 1002 } 1003 /* 1004 * Reset stack state to the user stack. 1005 * Clear set of signals caught on the signal stack. 1006 */ 1007 td = curthread; 1008 MPASS(td->td_proc == p); 1009 td->td_sigstk.ss_flags = SS_DISABLE; 1010 td->td_sigstk.ss_size = 0; 1011 td->td_sigstk.ss_sp = 0; 1012 td->td_pflags &= ~TDP_ALTSTACK; 1013 /* 1014 * Reset no zombies if child dies flag as Solaris does. 1015 */ 1016 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1017 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1018 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1019 mtx_unlock(&ps->ps_mtx); 1020 } 1021 1022 /* 1023 * kern_sigprocmask() 1024 * 1025 * Manipulate signal mask. 1026 */ 1027 int 1028 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1029 int flags) 1030 { 1031 sigset_t new_block, oset1; 1032 struct proc *p; 1033 int error; 1034 1035 p = td->td_proc; 1036 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1037 PROC_LOCK_ASSERT(p, MA_OWNED); 1038 else 1039 PROC_LOCK(p); 1040 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1041 ? MA_OWNED : MA_NOTOWNED); 1042 if (oset != NULL) 1043 *oset = td->td_sigmask; 1044 1045 error = 0; 1046 if (set != NULL) { 1047 switch (how) { 1048 case SIG_BLOCK: 1049 SIG_CANTMASK(*set); 1050 oset1 = td->td_sigmask; 1051 SIGSETOR(td->td_sigmask, *set); 1052 new_block = td->td_sigmask; 1053 SIGSETNAND(new_block, oset1); 1054 break; 1055 case SIG_UNBLOCK: 1056 SIGSETNAND(td->td_sigmask, *set); 1057 signotify(td); 1058 goto out; 1059 case SIG_SETMASK: 1060 SIG_CANTMASK(*set); 1061 oset1 = td->td_sigmask; 1062 if (flags & SIGPROCMASK_OLD) 1063 SIGSETLO(td->td_sigmask, *set); 1064 else 1065 td->td_sigmask = *set; 1066 new_block = td->td_sigmask; 1067 SIGSETNAND(new_block, oset1); 1068 signotify(td); 1069 break; 1070 default: 1071 error = EINVAL; 1072 goto out; 1073 } 1074 1075 /* 1076 * The new_block set contains signals that were not previously 1077 * blocked, but are blocked now. 1078 * 1079 * In case we block any signal that was not previously blocked 1080 * for td, and process has the signal pending, try to schedule 1081 * signal delivery to some thread that does not block the 1082 * signal, possibly waking it up. 1083 */ 1084 if (p->p_numthreads != 1) 1085 reschedule_signals(p, new_block, flags); 1086 } 1087 1088 out: 1089 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1090 PROC_UNLOCK(p); 1091 return (error); 1092 } 1093 1094 #ifndef _SYS_SYSPROTO_H_ 1095 struct sigprocmask_args { 1096 int how; 1097 const sigset_t *set; 1098 sigset_t *oset; 1099 }; 1100 #endif 1101 int 1102 sys_sigprocmask(td, uap) 1103 register struct thread *td; 1104 struct sigprocmask_args *uap; 1105 { 1106 sigset_t set, oset; 1107 sigset_t *setp, *osetp; 1108 int error; 1109 1110 setp = (uap->set != NULL) ? &set : NULL; 1111 osetp = (uap->oset != NULL) ? &oset : NULL; 1112 if (setp) { 1113 error = copyin(uap->set, setp, sizeof(set)); 1114 if (error) 1115 return (error); 1116 } 1117 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1118 if (osetp && !error) { 1119 error = copyout(osetp, uap->oset, sizeof(oset)); 1120 } 1121 return (error); 1122 } 1123 1124 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1125 #ifndef _SYS_SYSPROTO_H_ 1126 struct osigprocmask_args { 1127 int how; 1128 osigset_t mask; 1129 }; 1130 #endif 1131 int 1132 osigprocmask(td, uap) 1133 register struct thread *td; 1134 struct osigprocmask_args *uap; 1135 { 1136 sigset_t set, oset; 1137 int error; 1138 1139 OSIG2SIG(uap->mask, set); 1140 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1141 SIG2OSIG(oset, td->td_retval[0]); 1142 return (error); 1143 } 1144 #endif /* COMPAT_43 */ 1145 1146 int 1147 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1148 { 1149 ksiginfo_t ksi; 1150 sigset_t set; 1151 int error; 1152 1153 error = copyin(uap->set, &set, sizeof(set)); 1154 if (error) { 1155 td->td_retval[0] = error; 1156 return (0); 1157 } 1158 1159 error = kern_sigtimedwait(td, set, &ksi, NULL); 1160 if (error) { 1161 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1162 error = ERESTART; 1163 if (error == ERESTART) 1164 return (error); 1165 td->td_retval[0] = error; 1166 return (0); 1167 } 1168 1169 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1170 td->td_retval[0] = error; 1171 return (0); 1172 } 1173 1174 int 1175 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1176 { 1177 struct timespec ts; 1178 struct timespec *timeout; 1179 sigset_t set; 1180 ksiginfo_t ksi; 1181 int error; 1182 1183 if (uap->timeout) { 1184 error = copyin(uap->timeout, &ts, sizeof(ts)); 1185 if (error) 1186 return (error); 1187 1188 timeout = &ts; 1189 } else 1190 timeout = NULL; 1191 1192 error = copyin(uap->set, &set, sizeof(set)); 1193 if (error) 1194 return (error); 1195 1196 error = kern_sigtimedwait(td, set, &ksi, timeout); 1197 if (error) 1198 return (error); 1199 1200 if (uap->info) 1201 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1202 1203 if (error == 0) 1204 td->td_retval[0] = ksi.ksi_signo; 1205 return (error); 1206 } 1207 1208 int 1209 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1210 { 1211 ksiginfo_t ksi; 1212 sigset_t set; 1213 int error; 1214 1215 error = copyin(uap->set, &set, sizeof(set)); 1216 if (error) 1217 return (error); 1218 1219 error = kern_sigtimedwait(td, set, &ksi, NULL); 1220 if (error) 1221 return (error); 1222 1223 if (uap->info) 1224 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1225 1226 if (error == 0) 1227 td->td_retval[0] = ksi.ksi_signo; 1228 return (error); 1229 } 1230 1231 int 1232 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1233 struct timespec *timeout) 1234 { 1235 struct sigacts *ps; 1236 sigset_t saved_mask, new_block; 1237 struct proc *p; 1238 int error, sig, timo, timevalid = 0; 1239 struct timespec rts, ets, ts; 1240 struct timeval tv; 1241 1242 p = td->td_proc; 1243 error = 0; 1244 ets.tv_sec = 0; 1245 ets.tv_nsec = 0; 1246 1247 if (timeout != NULL) { 1248 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1249 timevalid = 1; 1250 getnanouptime(&rts); 1251 ets = rts; 1252 timespecadd(&ets, timeout); 1253 } 1254 } 1255 ksiginfo_init(ksi); 1256 /* Some signals can not be waited for. */ 1257 SIG_CANTMASK(waitset); 1258 ps = p->p_sigacts; 1259 PROC_LOCK(p); 1260 saved_mask = td->td_sigmask; 1261 SIGSETNAND(td->td_sigmask, waitset); 1262 for (;;) { 1263 mtx_lock(&ps->ps_mtx); 1264 sig = cursig(td); 1265 mtx_unlock(&ps->ps_mtx); 1266 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1267 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1268 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1269 error = 0; 1270 break; 1271 } 1272 } 1273 1274 if (error != 0) 1275 break; 1276 1277 /* 1278 * POSIX says this must be checked after looking for pending 1279 * signals. 1280 */ 1281 if (timeout != NULL) { 1282 if (!timevalid) { 1283 error = EINVAL; 1284 break; 1285 } 1286 getnanouptime(&rts); 1287 if (timespeccmp(&rts, &ets, >=)) { 1288 error = EAGAIN; 1289 break; 1290 } 1291 ts = ets; 1292 timespecsub(&ts, &rts); 1293 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1294 timo = tvtohz(&tv); 1295 } else { 1296 timo = 0; 1297 } 1298 1299 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1300 1301 if (timeout != NULL) { 1302 if (error == ERESTART) { 1303 /* Timeout can not be restarted. */ 1304 error = EINTR; 1305 } else if (error == EAGAIN) { 1306 /* We will calculate timeout by ourself. */ 1307 error = 0; 1308 } 1309 } 1310 } 1311 1312 new_block = saved_mask; 1313 SIGSETNAND(new_block, td->td_sigmask); 1314 td->td_sigmask = saved_mask; 1315 /* 1316 * Fewer signals can be delivered to us, reschedule signal 1317 * notification. 1318 */ 1319 if (p->p_numthreads != 1) 1320 reschedule_signals(p, new_block, 0); 1321 1322 if (error == 0) { 1323 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1324 1325 if (ksi->ksi_code == SI_TIMER) 1326 itimer_accept(p, ksi->ksi_timerid, ksi); 1327 1328 #ifdef KTRACE 1329 if (KTRPOINT(td, KTR_PSIG)) { 1330 sig_t action; 1331 1332 mtx_lock(&ps->ps_mtx); 1333 action = ps->ps_sigact[_SIG_IDX(sig)]; 1334 mtx_unlock(&ps->ps_mtx); 1335 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1336 } 1337 #endif 1338 if (sig == SIGKILL) 1339 sigexit(td, sig); 1340 } 1341 PROC_UNLOCK(p); 1342 return (error); 1343 } 1344 1345 #ifndef _SYS_SYSPROTO_H_ 1346 struct sigpending_args { 1347 sigset_t *set; 1348 }; 1349 #endif 1350 int 1351 sys_sigpending(td, uap) 1352 struct thread *td; 1353 struct sigpending_args *uap; 1354 { 1355 struct proc *p = td->td_proc; 1356 sigset_t pending; 1357 1358 PROC_LOCK(p); 1359 pending = p->p_sigqueue.sq_signals; 1360 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1361 PROC_UNLOCK(p); 1362 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1363 } 1364 1365 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1366 #ifndef _SYS_SYSPROTO_H_ 1367 struct osigpending_args { 1368 int dummy; 1369 }; 1370 #endif 1371 int 1372 osigpending(td, uap) 1373 struct thread *td; 1374 struct osigpending_args *uap; 1375 { 1376 struct proc *p = td->td_proc; 1377 sigset_t pending; 1378 1379 PROC_LOCK(p); 1380 pending = p->p_sigqueue.sq_signals; 1381 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1382 PROC_UNLOCK(p); 1383 SIG2OSIG(pending, td->td_retval[0]); 1384 return (0); 1385 } 1386 #endif /* COMPAT_43 */ 1387 1388 #if defined(COMPAT_43) 1389 /* 1390 * Generalized interface signal handler, 4.3-compatible. 1391 */ 1392 #ifndef _SYS_SYSPROTO_H_ 1393 struct osigvec_args { 1394 int signum; 1395 struct sigvec *nsv; 1396 struct sigvec *osv; 1397 }; 1398 #endif 1399 /* ARGSUSED */ 1400 int 1401 osigvec(td, uap) 1402 struct thread *td; 1403 register struct osigvec_args *uap; 1404 { 1405 struct sigvec vec; 1406 struct sigaction nsa, osa; 1407 register struct sigaction *nsap, *osap; 1408 int error; 1409 1410 if (uap->signum <= 0 || uap->signum >= ONSIG) 1411 return (EINVAL); 1412 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1413 osap = (uap->osv != NULL) ? &osa : NULL; 1414 if (nsap) { 1415 error = copyin(uap->nsv, &vec, sizeof(vec)); 1416 if (error) 1417 return (error); 1418 nsap->sa_handler = vec.sv_handler; 1419 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1420 nsap->sa_flags = vec.sv_flags; 1421 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1422 } 1423 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1424 if (osap && !error) { 1425 vec.sv_handler = osap->sa_handler; 1426 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1427 vec.sv_flags = osap->sa_flags; 1428 vec.sv_flags &= ~SA_NOCLDWAIT; 1429 vec.sv_flags ^= SA_RESTART; 1430 error = copyout(&vec, uap->osv, sizeof(vec)); 1431 } 1432 return (error); 1433 } 1434 1435 #ifndef _SYS_SYSPROTO_H_ 1436 struct osigblock_args { 1437 int mask; 1438 }; 1439 #endif 1440 int 1441 osigblock(td, uap) 1442 register struct thread *td; 1443 struct osigblock_args *uap; 1444 { 1445 sigset_t set, oset; 1446 1447 OSIG2SIG(uap->mask, set); 1448 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1449 SIG2OSIG(oset, td->td_retval[0]); 1450 return (0); 1451 } 1452 1453 #ifndef _SYS_SYSPROTO_H_ 1454 struct osigsetmask_args { 1455 int mask; 1456 }; 1457 #endif 1458 int 1459 osigsetmask(td, uap) 1460 struct thread *td; 1461 struct osigsetmask_args *uap; 1462 { 1463 sigset_t set, oset; 1464 1465 OSIG2SIG(uap->mask, set); 1466 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1467 SIG2OSIG(oset, td->td_retval[0]); 1468 return (0); 1469 } 1470 #endif /* COMPAT_43 */ 1471 1472 /* 1473 * Suspend calling thread until signal, providing mask to be set in the 1474 * meantime. 1475 */ 1476 #ifndef _SYS_SYSPROTO_H_ 1477 struct sigsuspend_args { 1478 const sigset_t *sigmask; 1479 }; 1480 #endif 1481 /* ARGSUSED */ 1482 int 1483 sys_sigsuspend(td, uap) 1484 struct thread *td; 1485 struct sigsuspend_args *uap; 1486 { 1487 sigset_t mask; 1488 int error; 1489 1490 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1491 if (error) 1492 return (error); 1493 return (kern_sigsuspend(td, mask)); 1494 } 1495 1496 int 1497 kern_sigsuspend(struct thread *td, sigset_t mask) 1498 { 1499 struct proc *p = td->td_proc; 1500 int has_sig, sig; 1501 1502 /* 1503 * When returning from sigsuspend, we want 1504 * the old mask to be restored after the 1505 * signal handler has finished. Thus, we 1506 * save it here and mark the sigacts structure 1507 * to indicate this. 1508 */ 1509 PROC_LOCK(p); 1510 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1511 SIGPROCMASK_PROC_LOCKED); 1512 td->td_pflags |= TDP_OLDMASK; 1513 1514 /* 1515 * Process signals now. Otherwise, we can get spurious wakeup 1516 * due to signal entered process queue, but delivered to other 1517 * thread. But sigsuspend should return only on signal 1518 * delivery. 1519 */ 1520 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1521 for (has_sig = 0; !has_sig;) { 1522 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1523 0) == 0) 1524 /* void */; 1525 thread_suspend_check(0); 1526 mtx_lock(&p->p_sigacts->ps_mtx); 1527 while ((sig = cursig(td)) != 0) 1528 has_sig += postsig(sig); 1529 mtx_unlock(&p->p_sigacts->ps_mtx); 1530 } 1531 PROC_UNLOCK(p); 1532 td->td_errno = EINTR; 1533 td->td_pflags |= TDP_NERRNO; 1534 return (EJUSTRETURN); 1535 } 1536 1537 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1538 /* 1539 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1540 * convention: libc stub passes mask, not pointer, to save a copyin. 1541 */ 1542 #ifndef _SYS_SYSPROTO_H_ 1543 struct osigsuspend_args { 1544 osigset_t mask; 1545 }; 1546 #endif 1547 /* ARGSUSED */ 1548 int 1549 osigsuspend(td, uap) 1550 struct thread *td; 1551 struct osigsuspend_args *uap; 1552 { 1553 sigset_t mask; 1554 1555 OSIG2SIG(uap->mask, mask); 1556 return (kern_sigsuspend(td, mask)); 1557 } 1558 #endif /* COMPAT_43 */ 1559 1560 #if defined(COMPAT_43) 1561 #ifndef _SYS_SYSPROTO_H_ 1562 struct osigstack_args { 1563 struct sigstack *nss; 1564 struct sigstack *oss; 1565 }; 1566 #endif 1567 /* ARGSUSED */ 1568 int 1569 osigstack(td, uap) 1570 struct thread *td; 1571 register struct osigstack_args *uap; 1572 { 1573 struct sigstack nss, oss; 1574 int error = 0; 1575 1576 if (uap->nss != NULL) { 1577 error = copyin(uap->nss, &nss, sizeof(nss)); 1578 if (error) 1579 return (error); 1580 } 1581 oss.ss_sp = td->td_sigstk.ss_sp; 1582 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1583 if (uap->nss != NULL) { 1584 td->td_sigstk.ss_sp = nss.ss_sp; 1585 td->td_sigstk.ss_size = 0; 1586 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1587 td->td_pflags |= TDP_ALTSTACK; 1588 } 1589 if (uap->oss != NULL) 1590 error = copyout(&oss, uap->oss, sizeof(oss)); 1591 1592 return (error); 1593 } 1594 #endif /* COMPAT_43 */ 1595 1596 #ifndef _SYS_SYSPROTO_H_ 1597 struct sigaltstack_args { 1598 stack_t *ss; 1599 stack_t *oss; 1600 }; 1601 #endif 1602 /* ARGSUSED */ 1603 int 1604 sys_sigaltstack(td, uap) 1605 struct thread *td; 1606 register struct sigaltstack_args *uap; 1607 { 1608 stack_t ss, oss; 1609 int error; 1610 1611 if (uap->ss != NULL) { 1612 error = copyin(uap->ss, &ss, sizeof(ss)); 1613 if (error) 1614 return (error); 1615 } 1616 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1617 (uap->oss != NULL) ? &oss : NULL); 1618 if (error) 1619 return (error); 1620 if (uap->oss != NULL) 1621 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1622 return (error); 1623 } 1624 1625 int 1626 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1627 { 1628 struct proc *p = td->td_proc; 1629 int oonstack; 1630 1631 oonstack = sigonstack(cpu_getstack(td)); 1632 1633 if (oss != NULL) { 1634 *oss = td->td_sigstk; 1635 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1636 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1637 } 1638 1639 if (ss != NULL) { 1640 if (oonstack) 1641 return (EPERM); 1642 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1643 return (EINVAL); 1644 if (!(ss->ss_flags & SS_DISABLE)) { 1645 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1646 return (ENOMEM); 1647 1648 td->td_sigstk = *ss; 1649 td->td_pflags |= TDP_ALTSTACK; 1650 } else { 1651 td->td_pflags &= ~TDP_ALTSTACK; 1652 } 1653 } 1654 return (0); 1655 } 1656 1657 /* 1658 * Common code for kill process group/broadcast kill. 1659 * cp is calling process. 1660 */ 1661 static int 1662 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1663 { 1664 struct proc *p; 1665 struct pgrp *pgrp; 1666 int err; 1667 int ret; 1668 1669 ret = ESRCH; 1670 if (all) { 1671 /* 1672 * broadcast 1673 */ 1674 sx_slock(&allproc_lock); 1675 FOREACH_PROC_IN_SYSTEM(p) { 1676 PROC_LOCK(p); 1677 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1678 p == td->td_proc || p->p_state == PRS_NEW) { 1679 PROC_UNLOCK(p); 1680 continue; 1681 } 1682 err = p_cansignal(td, p, sig); 1683 if (err == 0) { 1684 if (sig) 1685 pksignal(p, sig, ksi); 1686 ret = err; 1687 } 1688 else if (ret == ESRCH) 1689 ret = err; 1690 PROC_UNLOCK(p); 1691 } 1692 sx_sunlock(&allproc_lock); 1693 } else { 1694 sx_slock(&proctree_lock); 1695 if (pgid == 0) { 1696 /* 1697 * zero pgid means send to my process group. 1698 */ 1699 pgrp = td->td_proc->p_pgrp; 1700 PGRP_LOCK(pgrp); 1701 } else { 1702 pgrp = pgfind(pgid); 1703 if (pgrp == NULL) { 1704 sx_sunlock(&proctree_lock); 1705 return (ESRCH); 1706 } 1707 } 1708 sx_sunlock(&proctree_lock); 1709 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1710 PROC_LOCK(p); 1711 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1712 p->p_state == PRS_NEW) { 1713 PROC_UNLOCK(p); 1714 continue; 1715 } 1716 err = p_cansignal(td, p, sig); 1717 if (err == 0) { 1718 if (sig) 1719 pksignal(p, sig, ksi); 1720 ret = err; 1721 } 1722 else if (ret == ESRCH) 1723 ret = err; 1724 PROC_UNLOCK(p); 1725 } 1726 PGRP_UNLOCK(pgrp); 1727 } 1728 return (ret); 1729 } 1730 1731 #ifndef _SYS_SYSPROTO_H_ 1732 struct kill_args { 1733 int pid; 1734 int signum; 1735 }; 1736 #endif 1737 /* ARGSUSED */ 1738 int 1739 sys_kill(struct thread *td, struct kill_args *uap) 1740 { 1741 ksiginfo_t ksi; 1742 struct proc *p; 1743 int error; 1744 1745 /* 1746 * A process in capability mode can send signals only to himself. 1747 * The main rationale behind this is that abort(3) is implemented as 1748 * kill(getpid(), SIGABRT). 1749 */ 1750 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1751 return (ECAPMODE); 1752 1753 AUDIT_ARG_SIGNUM(uap->signum); 1754 AUDIT_ARG_PID(uap->pid); 1755 if ((u_int)uap->signum > _SIG_MAXSIG) 1756 return (EINVAL); 1757 1758 ksiginfo_init(&ksi); 1759 ksi.ksi_signo = uap->signum; 1760 ksi.ksi_code = SI_USER; 1761 ksi.ksi_pid = td->td_proc->p_pid; 1762 ksi.ksi_uid = td->td_ucred->cr_ruid; 1763 1764 if (uap->pid > 0) { 1765 /* kill single process */ 1766 if ((p = pfind(uap->pid)) == NULL) { 1767 if ((p = zpfind(uap->pid)) == NULL) 1768 return (ESRCH); 1769 } 1770 AUDIT_ARG_PROCESS(p); 1771 error = p_cansignal(td, p, uap->signum); 1772 if (error == 0 && uap->signum) 1773 pksignal(p, uap->signum, &ksi); 1774 PROC_UNLOCK(p); 1775 return (error); 1776 } 1777 switch (uap->pid) { 1778 case -1: /* broadcast signal */ 1779 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1780 case 0: /* signal own process group */ 1781 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1782 default: /* negative explicit process group */ 1783 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1784 } 1785 /* NOTREACHED */ 1786 } 1787 1788 int 1789 sys_pdkill(td, uap) 1790 struct thread *td; 1791 struct pdkill_args *uap; 1792 { 1793 #ifdef PROCDESC 1794 struct proc *p; 1795 cap_rights_t rights; 1796 int error; 1797 1798 AUDIT_ARG_SIGNUM(uap->signum); 1799 AUDIT_ARG_FD(uap->fd); 1800 if ((u_int)uap->signum > _SIG_MAXSIG) 1801 return (EINVAL); 1802 1803 error = procdesc_find(td, uap->fd, 1804 cap_rights_init(&rights, CAP_PDKILL), &p); 1805 if (error) 1806 return (error); 1807 AUDIT_ARG_PROCESS(p); 1808 error = p_cansignal(td, p, uap->signum); 1809 if (error == 0 && uap->signum) 1810 kern_psignal(p, uap->signum); 1811 PROC_UNLOCK(p); 1812 return (error); 1813 #else 1814 return (ENOSYS); 1815 #endif 1816 } 1817 1818 #if defined(COMPAT_43) 1819 #ifndef _SYS_SYSPROTO_H_ 1820 struct okillpg_args { 1821 int pgid; 1822 int signum; 1823 }; 1824 #endif 1825 /* ARGSUSED */ 1826 int 1827 okillpg(struct thread *td, struct okillpg_args *uap) 1828 { 1829 ksiginfo_t ksi; 1830 1831 AUDIT_ARG_SIGNUM(uap->signum); 1832 AUDIT_ARG_PID(uap->pgid); 1833 if ((u_int)uap->signum > _SIG_MAXSIG) 1834 return (EINVAL); 1835 1836 ksiginfo_init(&ksi); 1837 ksi.ksi_signo = uap->signum; 1838 ksi.ksi_code = SI_USER; 1839 ksi.ksi_pid = td->td_proc->p_pid; 1840 ksi.ksi_uid = td->td_ucred->cr_ruid; 1841 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1842 } 1843 #endif /* COMPAT_43 */ 1844 1845 #ifndef _SYS_SYSPROTO_H_ 1846 struct sigqueue_args { 1847 pid_t pid; 1848 int signum; 1849 /* union sigval */ void *value; 1850 }; 1851 #endif 1852 int 1853 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1854 { 1855 union sigval sv; 1856 1857 sv.sival_ptr = uap->value; 1858 1859 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1860 } 1861 1862 int 1863 kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1864 { 1865 ksiginfo_t ksi; 1866 struct proc *p; 1867 int error; 1868 1869 if ((u_int)signum > _SIG_MAXSIG) 1870 return (EINVAL); 1871 1872 /* 1873 * Specification says sigqueue can only send signal to 1874 * single process. 1875 */ 1876 if (pid <= 0) 1877 return (EINVAL); 1878 1879 if ((p = pfind(pid)) == NULL) { 1880 if ((p = zpfind(pid)) == NULL) 1881 return (ESRCH); 1882 } 1883 error = p_cansignal(td, p, signum); 1884 if (error == 0 && signum != 0) { 1885 ksiginfo_init(&ksi); 1886 ksi.ksi_flags = KSI_SIGQ; 1887 ksi.ksi_signo = signum; 1888 ksi.ksi_code = SI_QUEUE; 1889 ksi.ksi_pid = td->td_proc->p_pid; 1890 ksi.ksi_uid = td->td_ucred->cr_ruid; 1891 ksi.ksi_value = *value; 1892 error = pksignal(p, ksi.ksi_signo, &ksi); 1893 } 1894 PROC_UNLOCK(p); 1895 return (error); 1896 } 1897 1898 /* 1899 * Send a signal to a process group. 1900 */ 1901 void 1902 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1903 { 1904 struct pgrp *pgrp; 1905 1906 if (pgid != 0) { 1907 sx_slock(&proctree_lock); 1908 pgrp = pgfind(pgid); 1909 sx_sunlock(&proctree_lock); 1910 if (pgrp != NULL) { 1911 pgsignal(pgrp, sig, 0, ksi); 1912 PGRP_UNLOCK(pgrp); 1913 } 1914 } 1915 } 1916 1917 /* 1918 * Send a signal to a process group. If checktty is 1, 1919 * limit to members which have a controlling terminal. 1920 */ 1921 void 1922 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1923 { 1924 struct proc *p; 1925 1926 if (pgrp) { 1927 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1928 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1929 PROC_LOCK(p); 1930 if (p->p_state == PRS_NORMAL && 1931 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1932 pksignal(p, sig, ksi); 1933 PROC_UNLOCK(p); 1934 } 1935 } 1936 } 1937 1938 1939 /* 1940 * Recalculate the signal mask and reset the signal disposition after 1941 * usermode frame for delivery is formed. Should be called after 1942 * mach-specific routine, because sysent->sv_sendsig() needs correct 1943 * ps_siginfo and signal mask. 1944 */ 1945 static void 1946 postsig_done(int sig, struct thread *td, struct sigacts *ps) 1947 { 1948 sigset_t mask; 1949 1950 mtx_assert(&ps->ps_mtx, MA_OWNED); 1951 td->td_ru.ru_nsignals++; 1952 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1953 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1954 SIGADDSET(mask, sig); 1955 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1956 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1957 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1958 sigdflt(ps, sig); 1959 } 1960 1961 1962 /* 1963 * Send a signal caused by a trap to the current thread. If it will be 1964 * caught immediately, deliver it with correct code. Otherwise, post it 1965 * normally. 1966 */ 1967 void 1968 trapsignal(struct thread *td, ksiginfo_t *ksi) 1969 { 1970 struct sigacts *ps; 1971 struct proc *p; 1972 int sig; 1973 int code; 1974 1975 p = td->td_proc; 1976 sig = ksi->ksi_signo; 1977 code = ksi->ksi_code; 1978 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1979 1980 PROC_LOCK(p); 1981 ps = p->p_sigacts; 1982 mtx_lock(&ps->ps_mtx); 1983 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1984 !SIGISMEMBER(td->td_sigmask, sig)) { 1985 #ifdef KTRACE 1986 if (KTRPOINT(curthread, KTR_PSIG)) 1987 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1988 &td->td_sigmask, code); 1989 #endif 1990 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1991 ksi, &td->td_sigmask); 1992 postsig_done(sig, td, ps); 1993 mtx_unlock(&ps->ps_mtx); 1994 } else { 1995 /* 1996 * Avoid a possible infinite loop if the thread 1997 * masking the signal or process is ignoring the 1998 * signal. 1999 */ 2000 if (kern_forcesigexit && 2001 (SIGISMEMBER(td->td_sigmask, sig) || 2002 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2003 SIGDELSET(td->td_sigmask, sig); 2004 SIGDELSET(ps->ps_sigcatch, sig); 2005 SIGDELSET(ps->ps_sigignore, sig); 2006 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2007 } 2008 mtx_unlock(&ps->ps_mtx); 2009 p->p_code = code; /* XXX for core dump/debugger */ 2010 p->p_sig = sig; /* XXX to verify code */ 2011 tdsendsignal(p, td, sig, ksi); 2012 } 2013 PROC_UNLOCK(p); 2014 } 2015 2016 static struct thread * 2017 sigtd(struct proc *p, int sig, int prop) 2018 { 2019 struct thread *td, *signal_td; 2020 2021 PROC_LOCK_ASSERT(p, MA_OWNED); 2022 2023 /* 2024 * Check if current thread can handle the signal without 2025 * switching context to another thread. 2026 */ 2027 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2028 return (curthread); 2029 signal_td = NULL; 2030 FOREACH_THREAD_IN_PROC(p, td) { 2031 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2032 signal_td = td; 2033 break; 2034 } 2035 } 2036 if (signal_td == NULL) 2037 signal_td = FIRST_THREAD_IN_PROC(p); 2038 return (signal_td); 2039 } 2040 2041 /* 2042 * Send the signal to the process. If the signal has an action, the action 2043 * is usually performed by the target process rather than the caller; we add 2044 * the signal to the set of pending signals for the process. 2045 * 2046 * Exceptions: 2047 * o When a stop signal is sent to a sleeping process that takes the 2048 * default action, the process is stopped without awakening it. 2049 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2050 * regardless of the signal action (eg, blocked or ignored). 2051 * 2052 * Other ignored signals are discarded immediately. 2053 * 2054 * NB: This function may be entered from the debugger via the "kill" DDB 2055 * command. There is little that can be done to mitigate the possibly messy 2056 * side effects of this unwise possibility. 2057 */ 2058 void 2059 kern_psignal(struct proc *p, int sig) 2060 { 2061 ksiginfo_t ksi; 2062 2063 ksiginfo_init(&ksi); 2064 ksi.ksi_signo = sig; 2065 ksi.ksi_code = SI_KERNEL; 2066 (void) tdsendsignal(p, NULL, sig, &ksi); 2067 } 2068 2069 int 2070 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2071 { 2072 2073 return (tdsendsignal(p, NULL, sig, ksi)); 2074 } 2075 2076 /* Utility function for finding a thread to send signal event to. */ 2077 int 2078 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2079 { 2080 struct thread *td; 2081 2082 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2083 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2084 if (td == NULL) 2085 return (ESRCH); 2086 *ttd = td; 2087 } else { 2088 *ttd = NULL; 2089 PROC_LOCK(p); 2090 } 2091 return (0); 2092 } 2093 2094 void 2095 tdsignal(struct thread *td, int sig) 2096 { 2097 ksiginfo_t ksi; 2098 2099 ksiginfo_init(&ksi); 2100 ksi.ksi_signo = sig; 2101 ksi.ksi_code = SI_KERNEL; 2102 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2103 } 2104 2105 void 2106 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2107 { 2108 2109 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2110 } 2111 2112 int 2113 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2114 { 2115 sig_t action; 2116 sigqueue_t *sigqueue; 2117 int prop; 2118 struct sigacts *ps; 2119 int intrval; 2120 int ret = 0; 2121 int wakeup_swapper; 2122 2123 MPASS(td == NULL || p == td->td_proc); 2124 PROC_LOCK_ASSERT(p, MA_OWNED); 2125 2126 if (!_SIG_VALID(sig)) 2127 panic("%s(): invalid signal %d", __func__, sig); 2128 2129 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2130 2131 /* 2132 * IEEE Std 1003.1-2001: return success when killing a zombie. 2133 */ 2134 if (p->p_state == PRS_ZOMBIE) { 2135 if (ksi && (ksi->ksi_flags & KSI_INS)) 2136 ksiginfo_tryfree(ksi); 2137 return (ret); 2138 } 2139 2140 ps = p->p_sigacts; 2141 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2142 prop = sigprop(sig); 2143 2144 if (td == NULL) { 2145 td = sigtd(p, sig, prop); 2146 sigqueue = &p->p_sigqueue; 2147 } else 2148 sigqueue = &td->td_sigqueue; 2149 2150 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2151 2152 /* 2153 * If the signal is being ignored, 2154 * then we forget about it immediately. 2155 * (Note: we don't set SIGCONT in ps_sigignore, 2156 * and if it is set to SIG_IGN, 2157 * action will be SIG_DFL here.) 2158 */ 2159 mtx_lock(&ps->ps_mtx); 2160 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2161 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2162 2163 mtx_unlock(&ps->ps_mtx); 2164 if (ksi && (ksi->ksi_flags & KSI_INS)) 2165 ksiginfo_tryfree(ksi); 2166 return (ret); 2167 } 2168 if (SIGISMEMBER(td->td_sigmask, sig)) 2169 action = SIG_HOLD; 2170 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2171 action = SIG_CATCH; 2172 else 2173 action = SIG_DFL; 2174 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2175 intrval = EINTR; 2176 else 2177 intrval = ERESTART; 2178 mtx_unlock(&ps->ps_mtx); 2179 2180 if (prop & SA_CONT) 2181 sigqueue_delete_stopmask_proc(p); 2182 else if (prop & SA_STOP) { 2183 /* 2184 * If sending a tty stop signal to a member of an orphaned 2185 * process group, discard the signal here if the action 2186 * is default; don't stop the process below if sleeping, 2187 * and don't clear any pending SIGCONT. 2188 */ 2189 if ((prop & SA_TTYSTOP) && 2190 (p->p_pgrp->pg_jobc == 0) && 2191 (action == SIG_DFL)) { 2192 if (ksi && (ksi->ksi_flags & KSI_INS)) 2193 ksiginfo_tryfree(ksi); 2194 return (ret); 2195 } 2196 sigqueue_delete_proc(p, SIGCONT); 2197 if (p->p_flag & P_CONTINUED) { 2198 p->p_flag &= ~P_CONTINUED; 2199 PROC_LOCK(p->p_pptr); 2200 sigqueue_take(p->p_ksi); 2201 PROC_UNLOCK(p->p_pptr); 2202 } 2203 } 2204 2205 ret = sigqueue_add(sigqueue, sig, ksi); 2206 if (ret != 0) 2207 return (ret); 2208 signotify(td); 2209 /* 2210 * Defer further processing for signals which are held, 2211 * except that stopped processes must be continued by SIGCONT. 2212 */ 2213 if (action == SIG_HOLD && 2214 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2215 return (ret); 2216 2217 /* SIGKILL: Remove procfs STOPEVENTs. */ 2218 if (sig == SIGKILL) { 2219 /* from procfs_ioctl.c: PIOCBIC */ 2220 p->p_stops = 0; 2221 /* from procfs_ioctl.c: PIOCCONT */ 2222 p->p_step = 0; 2223 wakeup(&p->p_step); 2224 } 2225 /* 2226 * Some signals have a process-wide effect and a per-thread 2227 * component. Most processing occurs when the process next 2228 * tries to cross the user boundary, however there are some 2229 * times when processing needs to be done immediately, such as 2230 * waking up threads so that they can cross the user boundary. 2231 * We try to do the per-process part here. 2232 */ 2233 if (P_SHOULDSTOP(p)) { 2234 KASSERT(!(p->p_flag & P_WEXIT), 2235 ("signal to stopped but exiting process")); 2236 if (sig == SIGKILL) { 2237 /* 2238 * If traced process is already stopped, 2239 * then no further action is necessary. 2240 */ 2241 if (p->p_flag & P_TRACED) 2242 goto out; 2243 /* 2244 * SIGKILL sets process running. 2245 * It will die elsewhere. 2246 * All threads must be restarted. 2247 */ 2248 p->p_flag &= ~P_STOPPED_SIG; 2249 goto runfast; 2250 } 2251 2252 if (prop & SA_CONT) { 2253 /* 2254 * If traced process is already stopped, 2255 * then no further action is necessary. 2256 */ 2257 if (p->p_flag & P_TRACED) 2258 goto out; 2259 /* 2260 * If SIGCONT is default (or ignored), we continue the 2261 * process but don't leave the signal in sigqueue as 2262 * it has no further action. If SIGCONT is held, we 2263 * continue the process and leave the signal in 2264 * sigqueue. If the process catches SIGCONT, let it 2265 * handle the signal itself. If it isn't waiting on 2266 * an event, it goes back to run state. 2267 * Otherwise, process goes back to sleep state. 2268 */ 2269 p->p_flag &= ~P_STOPPED_SIG; 2270 PROC_SLOCK(p); 2271 if (p->p_numthreads == p->p_suspcount) { 2272 PROC_SUNLOCK(p); 2273 p->p_flag |= P_CONTINUED; 2274 p->p_xstat = SIGCONT; 2275 PROC_LOCK(p->p_pptr); 2276 childproc_continued(p); 2277 PROC_UNLOCK(p->p_pptr); 2278 PROC_SLOCK(p); 2279 } 2280 if (action == SIG_DFL) { 2281 thread_unsuspend(p); 2282 PROC_SUNLOCK(p); 2283 sigqueue_delete(sigqueue, sig); 2284 goto out; 2285 } 2286 if (action == SIG_CATCH) { 2287 /* 2288 * The process wants to catch it so it needs 2289 * to run at least one thread, but which one? 2290 */ 2291 PROC_SUNLOCK(p); 2292 goto runfast; 2293 } 2294 /* 2295 * The signal is not ignored or caught. 2296 */ 2297 thread_unsuspend(p); 2298 PROC_SUNLOCK(p); 2299 goto out; 2300 } 2301 2302 if (prop & SA_STOP) { 2303 /* 2304 * If traced process is already stopped, 2305 * then no further action is necessary. 2306 */ 2307 if (p->p_flag & P_TRACED) 2308 goto out; 2309 /* 2310 * Already stopped, don't need to stop again 2311 * (If we did the shell could get confused). 2312 * Just make sure the signal STOP bit set. 2313 */ 2314 p->p_flag |= P_STOPPED_SIG; 2315 sigqueue_delete(sigqueue, sig); 2316 goto out; 2317 } 2318 2319 /* 2320 * All other kinds of signals: 2321 * If a thread is sleeping interruptibly, simulate a 2322 * wakeup so that when it is continued it will be made 2323 * runnable and can look at the signal. However, don't make 2324 * the PROCESS runnable, leave it stopped. 2325 * It may run a bit until it hits a thread_suspend_check(). 2326 */ 2327 wakeup_swapper = 0; 2328 PROC_SLOCK(p); 2329 thread_lock(td); 2330 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2331 wakeup_swapper = sleepq_abort(td, intrval); 2332 thread_unlock(td); 2333 PROC_SUNLOCK(p); 2334 if (wakeup_swapper) 2335 kick_proc0(); 2336 goto out; 2337 /* 2338 * Mutexes are short lived. Threads waiting on them will 2339 * hit thread_suspend_check() soon. 2340 */ 2341 } else if (p->p_state == PRS_NORMAL) { 2342 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2343 tdsigwakeup(td, sig, action, intrval); 2344 goto out; 2345 } 2346 2347 MPASS(action == SIG_DFL); 2348 2349 if (prop & SA_STOP) { 2350 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2351 goto out; 2352 p->p_flag |= P_STOPPED_SIG; 2353 p->p_xstat = sig; 2354 PROC_SLOCK(p); 2355 sig_suspend_threads(td, p, 1); 2356 if (p->p_numthreads == p->p_suspcount) { 2357 /* 2358 * only thread sending signal to another 2359 * process can reach here, if thread is sending 2360 * signal to its process, because thread does 2361 * not suspend itself here, p_numthreads 2362 * should never be equal to p_suspcount. 2363 */ 2364 thread_stopped(p); 2365 PROC_SUNLOCK(p); 2366 sigqueue_delete_proc(p, p->p_xstat); 2367 } else 2368 PROC_SUNLOCK(p); 2369 goto out; 2370 } 2371 } else { 2372 /* Not in "NORMAL" state. discard the signal. */ 2373 sigqueue_delete(sigqueue, sig); 2374 goto out; 2375 } 2376 2377 /* 2378 * The process is not stopped so we need to apply the signal to all the 2379 * running threads. 2380 */ 2381 runfast: 2382 tdsigwakeup(td, sig, action, intrval); 2383 PROC_SLOCK(p); 2384 thread_unsuspend(p); 2385 PROC_SUNLOCK(p); 2386 out: 2387 /* If we jump here, proc slock should not be owned. */ 2388 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2389 return (ret); 2390 } 2391 2392 /* 2393 * The force of a signal has been directed against a single 2394 * thread. We need to see what we can do about knocking it 2395 * out of any sleep it may be in etc. 2396 */ 2397 static void 2398 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2399 { 2400 struct proc *p = td->td_proc; 2401 register int prop; 2402 int wakeup_swapper; 2403 2404 wakeup_swapper = 0; 2405 PROC_LOCK_ASSERT(p, MA_OWNED); 2406 prop = sigprop(sig); 2407 2408 PROC_SLOCK(p); 2409 thread_lock(td); 2410 /* 2411 * Bring the priority of a thread up if we want it to get 2412 * killed in this lifetime. Be careful to avoid bumping the 2413 * priority of the idle thread, since we still allow to signal 2414 * kernel processes. 2415 */ 2416 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2417 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2418 sched_prio(td, PUSER); 2419 if (TD_ON_SLEEPQ(td)) { 2420 /* 2421 * If thread is sleeping uninterruptibly 2422 * we can't interrupt the sleep... the signal will 2423 * be noticed when the process returns through 2424 * trap() or syscall(). 2425 */ 2426 if ((td->td_flags & TDF_SINTR) == 0) 2427 goto out; 2428 /* 2429 * If SIGCONT is default (or ignored) and process is 2430 * asleep, we are finished; the process should not 2431 * be awakened. 2432 */ 2433 if ((prop & SA_CONT) && action == SIG_DFL) { 2434 thread_unlock(td); 2435 PROC_SUNLOCK(p); 2436 sigqueue_delete(&p->p_sigqueue, sig); 2437 /* 2438 * It may be on either list in this state. 2439 * Remove from both for now. 2440 */ 2441 sigqueue_delete(&td->td_sigqueue, sig); 2442 return; 2443 } 2444 2445 /* 2446 * Don't awaken a sleeping thread for SIGSTOP if the 2447 * STOP signal is deferred. 2448 */ 2449 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2450 goto out; 2451 2452 /* 2453 * Give low priority threads a better chance to run. 2454 */ 2455 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2456 sched_prio(td, PUSER); 2457 2458 wakeup_swapper = sleepq_abort(td, intrval); 2459 } else { 2460 /* 2461 * Other states do nothing with the signal immediately, 2462 * other than kicking ourselves if we are running. 2463 * It will either never be noticed, or noticed very soon. 2464 */ 2465 #ifdef SMP 2466 if (TD_IS_RUNNING(td) && td != curthread) 2467 forward_signal(td); 2468 #endif 2469 } 2470 out: 2471 PROC_SUNLOCK(p); 2472 thread_unlock(td); 2473 if (wakeup_swapper) 2474 kick_proc0(); 2475 } 2476 2477 static void 2478 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2479 { 2480 struct thread *td2; 2481 2482 PROC_LOCK_ASSERT(p, MA_OWNED); 2483 PROC_SLOCK_ASSERT(p, MA_OWNED); 2484 2485 FOREACH_THREAD_IN_PROC(p, td2) { 2486 thread_lock(td2); 2487 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2488 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2489 (td2->td_flags & TDF_SINTR)) { 2490 if (td2->td_flags & TDF_SBDRY) { 2491 /* 2492 * Once a thread is asleep with 2493 * TDF_SBDRY set, it should never 2494 * become suspended due to this check. 2495 */ 2496 KASSERT(!TD_IS_SUSPENDED(td2), 2497 ("thread with deferred stops suspended")); 2498 } else if (!TD_IS_SUSPENDED(td2)) { 2499 thread_suspend_one(td2); 2500 } 2501 } else if (!TD_IS_SUSPENDED(td2)) { 2502 if (sending || td != td2) 2503 td2->td_flags |= TDF_ASTPENDING; 2504 #ifdef SMP 2505 if (TD_IS_RUNNING(td2) && td2 != td) 2506 forward_signal(td2); 2507 #endif 2508 } 2509 thread_unlock(td2); 2510 } 2511 } 2512 2513 /* 2514 * Stop the process for an event deemed interesting to the debugger. If si is 2515 * non-NULL, this is a signal exchange; the new signal requested by the 2516 * debugger will be returned for handling. If si is NULL, this is some other 2517 * type of interesting event. The debugger may request a signal be delivered in 2518 * that case as well, however it will be deferred until it can be handled. 2519 */ 2520 int 2521 ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2522 { 2523 struct proc *p = td->td_proc; 2524 struct thread *td2; 2525 ksiginfo_t ksi; 2526 int prop; 2527 2528 PROC_LOCK_ASSERT(p, MA_OWNED); 2529 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2530 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2531 &p->p_mtx.lock_object, "Stopping for traced signal"); 2532 2533 td->td_xsig = sig; 2534 2535 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2536 td->td_dbgflags |= TDB_XSIG; 2537 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2538 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2539 PROC_SLOCK(p); 2540 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2541 if (P_KILLED(p)) { 2542 /* 2543 * Ensure that, if we've been PT_KILLed, the 2544 * exit status reflects that. Another thread 2545 * may also be in ptracestop(), having just 2546 * received the SIGKILL, but this thread was 2547 * unsuspended first. 2548 */ 2549 td->td_dbgflags &= ~TDB_XSIG; 2550 td->td_xsig = SIGKILL; 2551 p->p_ptevents = 0; 2552 break; 2553 } 2554 if (p->p_flag & P_SINGLE_EXIT && 2555 !(td->td_dbgflags & TDB_EXIT)) { 2556 /* 2557 * Ignore ptrace stops except for thread exit 2558 * events when the process exits. 2559 */ 2560 td->td_dbgflags &= ~TDB_XSIG; 2561 PROC_SUNLOCK(p); 2562 return (0); 2563 } 2564 2565 /* 2566 * Make wait(2) work. Ensure that right after the 2567 * attach, the thread which was decided to become the 2568 * leader of attach gets reported to the waiter. 2569 * Otherwise, just avoid overwriting another thread's 2570 * assignment to p_xthread. If another thread has 2571 * already set p_xthread, the current thread will get 2572 * a chance to report itself upon the next iteration. 2573 */ 2574 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2575 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2576 p->p_xthread == NULL)) { 2577 p->p_xstat = sig; 2578 p->p_xthread = td; 2579 td->td_dbgflags &= ~TDB_FSTP; 2580 p->p_flag2 &= ~P2_PTRACE_FSTP; 2581 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2582 sig_suspend_threads(td, p, 0); 2583 } 2584 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2585 td->td_dbgflags &= ~TDB_STOPATFORK; 2586 cv_broadcast(&p->p_dbgwait); 2587 } 2588 stopme: 2589 thread_suspend_switch(td, p); 2590 if (p->p_xthread == td) 2591 p->p_xthread = NULL; 2592 if (!(p->p_flag & P_TRACED)) 2593 break; 2594 if (td->td_dbgflags & TDB_SUSPEND) { 2595 if (p->p_flag & P_SINGLE_EXIT) 2596 break; 2597 goto stopme; 2598 } 2599 } 2600 PROC_SUNLOCK(p); 2601 } 2602 2603 if (si != NULL && sig == td->td_xsig) { 2604 /* Parent wants us to take the original signal unchanged. */ 2605 si->ksi_flags |= KSI_HEAD; 2606 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2607 si->ksi_signo = 0; 2608 } else if (td->td_xsig != 0) { 2609 /* 2610 * If parent wants us to take a new signal, then it will leave 2611 * it in td->td_xsig; otherwise we just look for signals again. 2612 */ 2613 ksiginfo_init(&ksi); 2614 ksi.ksi_signo = td->td_xsig; 2615 ksi.ksi_flags |= KSI_PTRACE; 2616 prop = sigprop(td->td_xsig); 2617 td2 = sigtd(p, td->td_xsig, prop); 2618 tdsendsignal(p, td2, td->td_xsig, &ksi); 2619 if (td != td2) 2620 return (0); 2621 } 2622 2623 return (td->td_xsig); 2624 } 2625 2626 static void 2627 reschedule_signals(struct proc *p, sigset_t block, int flags) 2628 { 2629 struct sigacts *ps; 2630 struct thread *td; 2631 int sig; 2632 2633 PROC_LOCK_ASSERT(p, MA_OWNED); 2634 ps = p->p_sigacts; 2635 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2636 MA_OWNED : MA_NOTOWNED); 2637 if (SIGISEMPTY(p->p_siglist)) 2638 return; 2639 SIGSETAND(block, p->p_siglist); 2640 while ((sig = sig_ffs(&block)) != 0) { 2641 SIGDELSET(block, sig); 2642 td = sigtd(p, sig, 0); 2643 signotify(td); 2644 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2645 mtx_lock(&ps->ps_mtx); 2646 if (p->p_flag & P_TRACED || 2647 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2648 !SIGISMEMBER(td->td_sigmask, sig))) 2649 tdsigwakeup(td, sig, SIG_CATCH, 2650 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2651 ERESTART)); 2652 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2653 mtx_unlock(&ps->ps_mtx); 2654 } 2655 } 2656 2657 void 2658 tdsigcleanup(struct thread *td) 2659 { 2660 struct proc *p; 2661 sigset_t unblocked; 2662 2663 p = td->td_proc; 2664 PROC_LOCK_ASSERT(p, MA_OWNED); 2665 2666 sigqueue_flush(&td->td_sigqueue); 2667 if (p->p_numthreads == 1) 2668 return; 2669 2670 /* 2671 * Since we cannot handle signals, notify signal post code 2672 * about this by filling the sigmask. 2673 * 2674 * Also, if needed, wake up thread(s) that do not block the 2675 * same signals as the exiting thread, since the thread might 2676 * have been selected for delivery and woken up. 2677 */ 2678 SIGFILLSET(unblocked); 2679 SIGSETNAND(unblocked, td->td_sigmask); 2680 SIGFILLSET(td->td_sigmask); 2681 reschedule_signals(p, unblocked, 0); 2682 2683 } 2684 2685 /* 2686 * Defer the delivery of SIGSTOP for the current thread. Returns true 2687 * if stops were deferred and false if they were already deferred. 2688 */ 2689 int 2690 sigdeferstop(void) 2691 { 2692 struct thread *td; 2693 2694 td = curthread; 2695 if (td->td_flags & TDF_SBDRY) 2696 return (0); 2697 thread_lock(td); 2698 td->td_flags |= TDF_SBDRY; 2699 thread_unlock(td); 2700 return (1); 2701 } 2702 2703 /* 2704 * Permit the delivery of SIGSTOP for the current thread. This does 2705 * not immediately suspend if a stop was posted. Instead, the thread 2706 * will suspend either via ast() or a subsequent interruptible sleep. 2707 */ 2708 int 2709 sigallowstop(void) 2710 { 2711 struct thread *td; 2712 int prev; 2713 2714 td = curthread; 2715 thread_lock(td); 2716 prev = (td->td_flags & TDF_SBDRY) != 0; 2717 td->td_flags &= ~TDF_SBDRY; 2718 thread_unlock(td); 2719 return (prev); 2720 } 2721 2722 /* 2723 * If the current process has received a signal (should be caught or cause 2724 * termination, should interrupt current syscall), return the signal number. 2725 * Stop signals with default action are processed immediately, then cleared; 2726 * they aren't returned. This is checked after each entry to the system for 2727 * a syscall or trap (though this can usually be done without calling issignal 2728 * by checking the pending signal masks in cursig.) The normal call 2729 * sequence is 2730 * 2731 * while (sig = cursig(curthread)) 2732 * postsig(sig); 2733 */ 2734 static int 2735 issignal(struct thread *td) 2736 { 2737 struct proc *p; 2738 struct sigacts *ps; 2739 struct sigqueue *queue; 2740 sigset_t sigpending; 2741 int sig, prop; 2742 2743 p = td->td_proc; 2744 ps = p->p_sigacts; 2745 mtx_assert(&ps->ps_mtx, MA_OWNED); 2746 PROC_LOCK_ASSERT(p, MA_OWNED); 2747 for (;;) { 2748 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2749 2750 sigpending = td->td_sigqueue.sq_signals; 2751 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2752 SIGSETNAND(sigpending, td->td_sigmask); 2753 2754 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2755 SIG_STOPSIGMASK(sigpending); 2756 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2757 return (0); 2758 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2759 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2760 SIGISMEMBER(sigpending, SIGSTOP)) { 2761 /* 2762 * If debugger just attached, always consume 2763 * SIGSTOP from ptrace(PT_ATTACH) first, to 2764 * execute the debugger attach ritual in 2765 * order. 2766 */ 2767 sig = SIGSTOP; 2768 td->td_dbgflags |= TDB_FSTP; 2769 } else { 2770 sig = sig_ffs(&sigpending); 2771 } 2772 2773 if (p->p_stops & S_SIG) { 2774 mtx_unlock(&ps->ps_mtx); 2775 stopevent(p, S_SIG, sig); 2776 mtx_lock(&ps->ps_mtx); 2777 } 2778 2779 /* 2780 * We should see pending but ignored signals 2781 * only if P_TRACED was on when they were posted. 2782 */ 2783 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2784 sigqueue_delete(&td->td_sigqueue, sig); 2785 sigqueue_delete(&p->p_sigqueue, sig); 2786 continue; 2787 } 2788 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2789 /* 2790 * If traced, always stop. 2791 * Remove old signal from queue before the stop. 2792 * XXX shrug off debugger, it causes siginfo to 2793 * be thrown away. 2794 */ 2795 queue = &td->td_sigqueue; 2796 td->td_dbgksi.ksi_signo = 0; 2797 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2798 queue = &p->p_sigqueue; 2799 sigqueue_get(queue, sig, &td->td_dbgksi); 2800 } 2801 2802 mtx_unlock(&ps->ps_mtx); 2803 sig = ptracestop(td, sig, &td->td_dbgksi); 2804 mtx_lock(&ps->ps_mtx); 2805 2806 /* 2807 * Keep looking if the debugger discarded the signal 2808 * or replaced it with a masked signal. 2809 * 2810 * If the traced bit got turned off, go back up 2811 * to the top to rescan signals. This ensures 2812 * that p_sig* and p_sigact are consistent. 2813 */ 2814 if (sig == 0 || (p->p_flag & P_TRACED) == 0) 2815 continue; 2816 } 2817 2818 prop = sigprop(sig); 2819 2820 /* 2821 * Decide whether the signal should be returned. 2822 * Return the signal's number, or fall through 2823 * to clear it from the pending mask. 2824 */ 2825 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2826 2827 case (intptr_t)SIG_DFL: 2828 /* 2829 * Don't take default actions on system processes. 2830 */ 2831 if (p->p_pid <= 1) { 2832 #ifdef DIAGNOSTIC 2833 /* 2834 * Are you sure you want to ignore SIGSEGV 2835 * in init? XXX 2836 */ 2837 printf("Process (pid %lu) got signal %d\n", 2838 (u_long)p->p_pid, sig); 2839 #endif 2840 break; /* == ignore */ 2841 } 2842 /* 2843 * If there is a pending stop signal to process with 2844 * default action, stop here, then clear the signal. 2845 * Traced or exiting processes should ignore stops. 2846 * Additionally, a member of an orphaned process group 2847 * should ignore tty stops. 2848 */ 2849 if (prop & SA_STOP) { 2850 if (p->p_flag & 2851 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2852 (p->p_pgrp->pg_jobc == 0 && 2853 prop & SA_TTYSTOP)) 2854 break; /* == ignore */ 2855 mtx_unlock(&ps->ps_mtx); 2856 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2857 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2858 sigqueue_delete(&td->td_sigqueue, sig); 2859 sigqueue_delete(&p->p_sigqueue, sig); 2860 p->p_flag |= P_STOPPED_SIG; 2861 p->p_xstat = sig; 2862 PROC_SLOCK(p); 2863 sig_suspend_threads(td, p, 0); 2864 thread_suspend_switch(td, p); 2865 PROC_SUNLOCK(p); 2866 mtx_lock(&ps->ps_mtx); 2867 goto next; 2868 } else if (prop & SA_IGNORE) { 2869 /* 2870 * Except for SIGCONT, shouldn't get here. 2871 * Default action is to ignore; drop it. 2872 */ 2873 break; /* == ignore */ 2874 } else 2875 return (sig); 2876 /*NOTREACHED*/ 2877 2878 case (intptr_t)SIG_IGN: 2879 /* 2880 * Masking above should prevent us ever trying 2881 * to take action on an ignored signal other 2882 * than SIGCONT, unless process is traced. 2883 */ 2884 if ((prop & SA_CONT) == 0 && 2885 (p->p_flag & P_TRACED) == 0) 2886 printf("issignal\n"); 2887 break; /* == ignore */ 2888 2889 default: 2890 /* 2891 * This signal has an action, let 2892 * postsig() process it. 2893 */ 2894 return (sig); 2895 } 2896 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2897 sigqueue_delete(&p->p_sigqueue, sig); 2898 next:; 2899 } 2900 /* NOTREACHED */ 2901 } 2902 2903 void 2904 thread_stopped(struct proc *p) 2905 { 2906 int n; 2907 2908 PROC_LOCK_ASSERT(p, MA_OWNED); 2909 PROC_SLOCK_ASSERT(p, MA_OWNED); 2910 n = p->p_suspcount; 2911 if (p == curproc) 2912 n++; 2913 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2914 PROC_SUNLOCK(p); 2915 p->p_flag &= ~P_WAITED; 2916 PROC_LOCK(p->p_pptr); 2917 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2918 CLD_TRAPPED : CLD_STOPPED); 2919 PROC_UNLOCK(p->p_pptr); 2920 PROC_SLOCK(p); 2921 } 2922 } 2923 2924 /* 2925 * Take the action for the specified signal 2926 * from the current set of pending signals. 2927 */ 2928 int 2929 postsig(sig) 2930 register int sig; 2931 { 2932 struct thread *td = curthread; 2933 register struct proc *p = td->td_proc; 2934 struct sigacts *ps; 2935 sig_t action; 2936 ksiginfo_t ksi; 2937 sigset_t returnmask; 2938 2939 KASSERT(sig != 0, ("postsig")); 2940 2941 PROC_LOCK_ASSERT(p, MA_OWNED); 2942 ps = p->p_sigacts; 2943 mtx_assert(&ps->ps_mtx, MA_OWNED); 2944 ksiginfo_init(&ksi); 2945 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2946 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2947 return (0); 2948 ksi.ksi_signo = sig; 2949 if (ksi.ksi_code == SI_TIMER) 2950 itimer_accept(p, ksi.ksi_timerid, &ksi); 2951 action = ps->ps_sigact[_SIG_IDX(sig)]; 2952 #ifdef KTRACE 2953 if (KTRPOINT(td, KTR_PSIG)) 2954 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2955 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2956 #endif 2957 if (p->p_stops & S_SIG) { 2958 mtx_unlock(&ps->ps_mtx); 2959 stopevent(p, S_SIG, sig); 2960 mtx_lock(&ps->ps_mtx); 2961 } 2962 2963 if (action == SIG_DFL) { 2964 /* 2965 * Default action, where the default is to kill 2966 * the process. (Other cases were ignored above.) 2967 */ 2968 mtx_unlock(&ps->ps_mtx); 2969 sigexit(td, sig); 2970 /* NOTREACHED */ 2971 } else { 2972 /* 2973 * If we get here, the signal must be caught. 2974 */ 2975 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2976 ("postsig action")); 2977 /* 2978 * Set the new mask value and also defer further 2979 * occurrences of this signal. 2980 * 2981 * Special case: user has done a sigsuspend. Here the 2982 * current mask is not of interest, but rather the 2983 * mask from before the sigsuspend is what we want 2984 * restored after the signal processing is completed. 2985 */ 2986 if (td->td_pflags & TDP_OLDMASK) { 2987 returnmask = td->td_oldsigmask; 2988 td->td_pflags &= ~TDP_OLDMASK; 2989 } else 2990 returnmask = td->td_sigmask; 2991 2992 if (p->p_sig == sig) { 2993 p->p_code = 0; 2994 p->p_sig = 0; 2995 } 2996 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2997 postsig_done(sig, td, ps); 2998 } 2999 return (1); 3000 } 3001 3002 /* 3003 * Kill the current process for stated reason. 3004 */ 3005 void 3006 killproc(p, why) 3007 struct proc *p; 3008 char *why; 3009 { 3010 3011 PROC_LOCK_ASSERT(p, MA_OWNED); 3012 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3013 p->p_comm); 3014 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3015 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3016 p->p_flag |= P_WKILLED; 3017 kern_psignal(p, SIGKILL); 3018 } 3019 3020 /* 3021 * Force the current process to exit with the specified signal, dumping core 3022 * if appropriate. We bypass the normal tests for masked and caught signals, 3023 * allowing unrecoverable failures to terminate the process without changing 3024 * signal state. Mark the accounting record with the signal termination. 3025 * If dumping core, save the signal number for the debugger. Calls exit and 3026 * does not return. 3027 */ 3028 void 3029 sigexit(td, sig) 3030 struct thread *td; 3031 int sig; 3032 { 3033 struct proc *p = td->td_proc; 3034 3035 PROC_LOCK_ASSERT(p, MA_OWNED); 3036 p->p_acflag |= AXSIG; 3037 /* 3038 * We must be single-threading to generate a core dump. This 3039 * ensures that the registers in the core file are up-to-date. 3040 * Also, the ELF dump handler assumes that the thread list doesn't 3041 * change out from under it. 3042 * 3043 * XXX If another thread attempts to single-thread before us 3044 * (e.g. via fork()), we won't get a dump at all. 3045 */ 3046 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 3047 p->p_sig = sig; 3048 /* 3049 * Log signals which would cause core dumps 3050 * (Log as LOG_INFO to appease those who don't want 3051 * these messages.) 3052 * XXX : Todo, as well as euid, write out ruid too 3053 * Note that coredump() drops proc lock. 3054 */ 3055 if (coredump(td) == 0) 3056 sig |= WCOREFLAG; 3057 if (kern_logsigexit) 3058 log(LOG_INFO, 3059 "pid %d (%s), uid %d: exited on signal %d%s\n", 3060 p->p_pid, p->p_comm, 3061 td->td_ucred ? td->td_ucred->cr_uid : -1, 3062 sig &~ WCOREFLAG, 3063 sig & WCOREFLAG ? " (core dumped)" : ""); 3064 } else 3065 PROC_UNLOCK(p); 3066 exit1(td, W_EXITCODE(0, sig)); 3067 /* NOTREACHED */ 3068 } 3069 3070 /* 3071 * Send queued SIGCHLD to parent when child process's state 3072 * is changed. 3073 */ 3074 static void 3075 sigparent(struct proc *p, int reason, int status) 3076 { 3077 PROC_LOCK_ASSERT(p, MA_OWNED); 3078 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3079 3080 if (p->p_ksi != NULL) { 3081 p->p_ksi->ksi_signo = SIGCHLD; 3082 p->p_ksi->ksi_code = reason; 3083 p->p_ksi->ksi_status = status; 3084 p->p_ksi->ksi_pid = p->p_pid; 3085 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3086 if (KSI_ONQ(p->p_ksi)) 3087 return; 3088 } 3089 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3090 } 3091 3092 static void 3093 childproc_jobstate(struct proc *p, int reason, int sig) 3094 { 3095 struct sigacts *ps; 3096 3097 PROC_LOCK_ASSERT(p, MA_OWNED); 3098 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3099 3100 /* 3101 * Wake up parent sleeping in kern_wait(), also send 3102 * SIGCHLD to parent, but SIGCHLD does not guarantee 3103 * that parent will awake, because parent may masked 3104 * the signal. 3105 */ 3106 p->p_pptr->p_flag |= P_STATCHILD; 3107 wakeup(p->p_pptr); 3108 3109 ps = p->p_pptr->p_sigacts; 3110 mtx_lock(&ps->ps_mtx); 3111 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3112 mtx_unlock(&ps->ps_mtx); 3113 sigparent(p, reason, sig); 3114 } else 3115 mtx_unlock(&ps->ps_mtx); 3116 } 3117 3118 void 3119 childproc_stopped(struct proc *p, int reason) 3120 { 3121 /* p_xstat is a plain signal number, not a full wait() status here. */ 3122 childproc_jobstate(p, reason, p->p_xstat); 3123 } 3124 3125 void 3126 childproc_continued(struct proc *p) 3127 { 3128 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3129 } 3130 3131 void 3132 childproc_exited(struct proc *p) 3133 { 3134 int reason; 3135 int xstat = p->p_xstat; /* convert to int */ 3136 int status; 3137 3138 if (WCOREDUMP(xstat)) 3139 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3140 else if (WIFSIGNALED(xstat)) 3141 reason = CLD_KILLED, status = WTERMSIG(xstat); 3142 else 3143 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3144 /* 3145 * XXX avoid calling wakeup(p->p_pptr), the work is 3146 * done in exit1(). 3147 */ 3148 sigparent(p, reason, status); 3149 } 3150 3151 /* 3152 * We only have 1 character for the core count in the format 3153 * string, so the range will be 0-9 3154 */ 3155 #define MAX_NUM_CORES 10 3156 static int num_cores = 5; 3157 3158 static int 3159 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3160 { 3161 int error; 3162 int new_val; 3163 3164 new_val = num_cores; 3165 error = sysctl_handle_int(oidp, &new_val, 0, req); 3166 if (error != 0 || req->newptr == NULL) 3167 return (error); 3168 if (new_val > MAX_NUM_CORES) 3169 new_val = MAX_NUM_CORES; 3170 if (new_val < 0) 3171 new_val = 0; 3172 num_cores = new_val; 3173 return (0); 3174 } 3175 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3176 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3177 3178 #if defined(COMPRESS_USER_CORES) 3179 int compress_user_cores = 1; 3180 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3181 &compress_user_cores, 0, "Compression of user corefiles"); 3182 3183 int compress_user_cores_gzlevel = -1; /* default level */ 3184 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3185 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3186 3187 #define GZ_SUFFIX ".gz" 3188 #define GZ_SUFFIX_LEN 3 3189 #endif 3190 3191 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3192 TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3193 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3194 sizeof(corefilename), "Process corefile name format string"); 3195 3196 /* 3197 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3198 * Expand the name described in corefilename, using name, uid, and pid 3199 * and open/create core file. 3200 * corefilename is a printf-like string, with three format specifiers: 3201 * %N name of process ("name") 3202 * %P process id (pid) 3203 * %U user id (uid) 3204 * For example, "%N.core" is the default; they can be disabled completely 3205 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3206 * This is controlled by the sysctl variable kern.corefile (see above). 3207 */ 3208 static int 3209 corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3210 int compress, struct vnode **vpp, char **namep) 3211 { 3212 struct nameidata nd; 3213 struct sbuf sb; 3214 const char *format; 3215 char *hostname, *name; 3216 int indexpos, i, error, cmode, flags, oflags; 3217 3218 hostname = NULL; 3219 format = corefilename; 3220 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3221 indexpos = -1; 3222 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3223 for (i = 0; format[i] != '\0'; i++) { 3224 switch (format[i]) { 3225 case '%': /* Format character */ 3226 i++; 3227 switch (format[i]) { 3228 case '%': 3229 sbuf_putc(&sb, '%'); 3230 break; 3231 case 'H': /* hostname */ 3232 if (hostname == NULL) { 3233 hostname = malloc(MAXHOSTNAMELEN, 3234 M_TEMP, M_WAITOK); 3235 } 3236 getcredhostname(td->td_ucred, hostname, 3237 MAXHOSTNAMELEN); 3238 sbuf_printf(&sb, "%s", hostname); 3239 break; 3240 case 'I': /* autoincrementing index */ 3241 sbuf_printf(&sb, ""); 3242 indexpos = sbuf_len(&sb) - 1; 3243 break; 3244 case 'N': /* process name */ 3245 sbuf_printf(&sb, "%s", comm); 3246 break; 3247 case 'P': /* process id */ 3248 sbuf_printf(&sb, "%u", pid); 3249 break; 3250 case 'U': /* user id */ 3251 sbuf_printf(&sb, "%u", uid); 3252 break; 3253 default: 3254 log(LOG_ERR, 3255 "Unknown format character %c in " 3256 "corename `%s'\n", format[i], format); 3257 break; 3258 } 3259 break; 3260 default: 3261 sbuf_putc(&sb, format[i]); 3262 break; 3263 } 3264 } 3265 free(hostname, M_TEMP); 3266 #ifdef COMPRESS_USER_CORES 3267 if (compress) 3268 sbuf_printf(&sb, GZ_SUFFIX); 3269 #endif 3270 if (sbuf_error(&sb) != 0) { 3271 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3272 "long\n", (long)pid, comm, (u_long)uid); 3273 sbuf_delete(&sb); 3274 free(name, M_TEMP); 3275 return (ENOMEM); 3276 } 3277 sbuf_finish(&sb); 3278 sbuf_delete(&sb); 3279 3280 cmode = S_IRUSR | S_IWUSR; 3281 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3282 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3283 3284 /* 3285 * If the core format has a %I in it, then we need to check 3286 * for existing corefiles before returning a name. 3287 * To do this we iterate over 0..num_cores to find a 3288 * non-existing core file name to use. 3289 */ 3290 if (indexpos != -1) { 3291 for (i = 0; i < num_cores; i++) { 3292 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3293 name[indexpos] = '' + i; 3294 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3295 error = vn_open_cred(&nd, &flags, cmode, oflags, 3296 td->td_ucred, NULL); 3297 if (error) { 3298 if (error == EEXIST) 3299 continue; 3300 log(LOG_ERR, 3301 "pid %d (%s), uid (%u): Path `%s' failed " 3302 "on initial open test, error = %d\n", 3303 pid, comm, uid, name, error); 3304 } 3305 goto out; 3306 } 3307 } 3308 3309 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3310 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3311 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3312 out: 3313 if (error) { 3314 #ifdef AUDIT 3315 audit_proc_coredump(td, name, error); 3316 #endif 3317 free(name, M_TEMP); 3318 return (error); 3319 } 3320 NDFREE(&nd, NDF_ONLY_PNBUF); 3321 *vpp = nd.ni_vp; 3322 *namep = name; 3323 return (0); 3324 } 3325 3326 static int 3327 coredump_sanitise_path(const char *path) 3328 { 3329 size_t i; 3330 3331 /* 3332 * Only send a subset of ASCII to devd(8) because it 3333 * might pass these strings to sh -c. 3334 */ 3335 for (i = 0; path[i]; i++) 3336 if (!(isalpha(path[i]) || isdigit(path[i])) && 3337 path[i] != '/' && path[i] != '.' && 3338 path[i] != '-') 3339 return (0); 3340 3341 return (1); 3342 } 3343 3344 /* 3345 * Dump a process' core. The main routine does some 3346 * policy checking, and creates the name of the coredump; 3347 * then it passes on a vnode and a size limit to the process-specific 3348 * coredump routine if there is one; if there _is not_ one, it returns 3349 * ENOSYS; otherwise it returns the error from the process-specific routine. 3350 */ 3351 3352 static int 3353 coredump(struct thread *td) 3354 { 3355 struct proc *p = td->td_proc; 3356 struct ucred *cred = td->td_ucred; 3357 struct vnode *vp; 3358 struct flock lf; 3359 struct vattr vattr; 3360 int error, error1, locked; 3361 struct mount *mp; 3362 char *name; /* name of corefile */ 3363 off_t limit; 3364 int compress; 3365 char *data = NULL; 3366 char *fullpath, *freepath = NULL; 3367 size_t len; 3368 static const char comm_name[] = "comm="; 3369 static const char core_name[] = "core="; 3370 3371 #ifdef COMPRESS_USER_CORES 3372 compress = compress_user_cores; 3373 #else 3374 compress = 0; 3375 #endif 3376 PROC_LOCK_ASSERT(p, MA_OWNED); 3377 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3378 _STOPEVENT(p, S_CORE, 0); 3379 3380 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3381 (p->p_flag2 & P2_NOTRACE) != 0) { 3382 PROC_UNLOCK(p); 3383 return (EFAULT); 3384 } 3385 3386 /* 3387 * Note that the bulk of limit checking is done after 3388 * the corefile is created. The exception is if the limit 3389 * for corefiles is 0, in which case we don't bother 3390 * creating the corefile at all. This layout means that 3391 * a corefile is truncated instead of not being created, 3392 * if it is larger than the limit. 3393 */ 3394 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3395 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3396 PROC_UNLOCK(p); 3397 return (EFBIG); 3398 } 3399 PROC_UNLOCK(p); 3400 3401 restart: 3402 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3403 &vp, &name); 3404 if (error != 0) 3405 return (error); 3406 3407 /* Don't dump to non-regular files or files with links. */ 3408 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3409 vattr.va_nlink != 1) { 3410 VOP_UNLOCK(vp, 0); 3411 error = EFAULT; 3412 goto out; 3413 } 3414 3415 VOP_UNLOCK(vp, 0); 3416 lf.l_whence = SEEK_SET; 3417 lf.l_start = 0; 3418 lf.l_len = 0; 3419 lf.l_type = F_WRLCK; 3420 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3421 3422 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3423 lf.l_type = F_UNLCK; 3424 if (locked) 3425 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3426 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3427 goto out; 3428 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3429 goto out; 3430 free(name, M_TEMP); 3431 goto restart; 3432 } 3433 3434 VATTR_NULL(&vattr); 3435 vattr.va_size = 0; 3436 if (set_core_nodump_flag) 3437 vattr.va_flags = UF_NODUMP; 3438 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3439 VOP_SETATTR(vp, &vattr, cred); 3440 VOP_UNLOCK(vp, 0); 3441 vn_finished_write(mp); 3442 PROC_LOCK(p); 3443 p->p_acflag |= ACORE; 3444 PROC_UNLOCK(p); 3445 3446 if (p->p_sysent->sv_coredump != NULL) { 3447 error = p->p_sysent->sv_coredump(td, vp, limit, 3448 compress ? IMGACT_CORE_COMPRESS : 0); 3449 } else { 3450 error = ENOSYS; 3451 } 3452 3453 if (locked) { 3454 lf.l_type = F_UNLCK; 3455 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3456 } 3457 3458 /* 3459 * Notify the userland helper that a process triggered a core dump. 3460 * This allows the helper to run an automated debugging session. 3461 */ 3462 if (error != 0 || coredump_devctl == 0) 3463 goto out; 3464 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3465 sizeof(' ') + sizeof(core_name) - 1; 3466 data = malloc(len, M_TEMP, M_WAITOK); 3467 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3468 goto out; 3469 if (!coredump_sanitise_path(fullpath)) 3470 goto out; 3471 snprintf(data, len, "%s%s ", comm_name, fullpath); 3472 free(freepath, M_TEMP); 3473 freepath = NULL; 3474 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3475 goto out; 3476 if (!coredump_sanitise_path(fullpath)) 3477 goto out; 3478 strlcat(data, core_name, len); 3479 strlcat(data, fullpath, len); 3480 devctl_notify("kernel", "signal", "coredump", data); 3481 out: 3482 error1 = vn_close(vp, FWRITE, cred, td); 3483 if (error == 0) 3484 error = error1; 3485 #ifdef AUDIT 3486 audit_proc_coredump(td, name, error); 3487 #endif 3488 free(freepath, M_TEMP); 3489 free(data, M_TEMP); 3490 free(name, M_TEMP); 3491 return (error); 3492 } 3493 3494 /* 3495 * Nonexistent system call-- signal process (may want to handle it). Flag 3496 * error in case process won't see signal immediately (blocked or ignored). 3497 */ 3498 #ifndef _SYS_SYSPROTO_H_ 3499 struct nosys_args { 3500 int dummy; 3501 }; 3502 #endif 3503 /* ARGSUSED */ 3504 int 3505 nosys(td, args) 3506 struct thread *td; 3507 struct nosys_args *args; 3508 { 3509 struct proc *p = td->td_proc; 3510 3511 PROC_LOCK(p); 3512 tdsignal(td, SIGSYS); 3513 PROC_UNLOCK(p); 3514 return (ENOSYS); 3515 } 3516 3517 /* 3518 * Send a SIGIO or SIGURG signal to a process or process group using stored 3519 * credentials rather than those of the current process. 3520 */ 3521 void 3522 pgsigio(sigiop, sig, checkctty) 3523 struct sigio **sigiop; 3524 int sig, checkctty; 3525 { 3526 ksiginfo_t ksi; 3527 struct sigio *sigio; 3528 3529 ksiginfo_init(&ksi); 3530 ksi.ksi_signo = sig; 3531 ksi.ksi_code = SI_KERNEL; 3532 3533 SIGIO_LOCK(); 3534 sigio = *sigiop; 3535 if (sigio == NULL) { 3536 SIGIO_UNLOCK(); 3537 return; 3538 } 3539 if (sigio->sio_pgid > 0) { 3540 PROC_LOCK(sigio->sio_proc); 3541 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3542 kern_psignal(sigio->sio_proc, sig); 3543 PROC_UNLOCK(sigio->sio_proc); 3544 } else if (sigio->sio_pgid < 0) { 3545 struct proc *p; 3546 3547 PGRP_LOCK(sigio->sio_pgrp); 3548 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3549 PROC_LOCK(p); 3550 if (p->p_state == PRS_NORMAL && 3551 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3552 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3553 kern_psignal(p, sig); 3554 PROC_UNLOCK(p); 3555 } 3556 PGRP_UNLOCK(sigio->sio_pgrp); 3557 } 3558 SIGIO_UNLOCK(); 3559 } 3560 3561 static int 3562 filt_sigattach(struct knote *kn) 3563 { 3564 struct proc *p = curproc; 3565 3566 kn->kn_ptr.p_proc = p; 3567 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3568 3569 knlist_add(&p->p_klist, kn, 0); 3570 3571 return (0); 3572 } 3573 3574 static void 3575 filt_sigdetach(struct knote *kn) 3576 { 3577 struct proc *p = kn->kn_ptr.p_proc; 3578 3579 knlist_remove(&p->p_klist, kn, 0); 3580 } 3581 3582 /* 3583 * signal knotes are shared with proc knotes, so we apply a mask to 3584 * the hint in order to differentiate them from process hints. This 3585 * could be avoided by using a signal-specific knote list, but probably 3586 * isn't worth the trouble. 3587 */ 3588 static int 3589 filt_signal(struct knote *kn, long hint) 3590 { 3591 3592 if (hint & NOTE_SIGNAL) { 3593 hint &= ~NOTE_SIGNAL; 3594 3595 if (kn->kn_id == hint) 3596 kn->kn_data++; 3597 } 3598 return (kn->kn_data != 0); 3599 } 3600 3601 struct sigacts * 3602 sigacts_alloc(void) 3603 { 3604 struct sigacts *ps; 3605 3606 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3607 ps->ps_refcnt = 1; 3608 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3609 return (ps); 3610 } 3611 3612 void 3613 sigacts_free(struct sigacts *ps) 3614 { 3615 3616 if (refcount_release(&ps->ps_refcnt) == 0) 3617 return; 3618 mtx_destroy(&ps->ps_mtx); 3619 free(ps, M_SUBPROC); 3620 } 3621 3622 struct sigacts * 3623 sigacts_hold(struct sigacts *ps) 3624 { 3625 3626 refcount_acquire(&ps->ps_refcnt); 3627 return (ps); 3628 } 3629 3630 void 3631 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3632 { 3633 3634 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3635 mtx_lock(&src->ps_mtx); 3636 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3637 mtx_unlock(&src->ps_mtx); 3638 } 3639 3640 int 3641 sigacts_shared(struct sigacts *ps) 3642 { 3643 3644 return (ps->ps_refcnt > 1); 3645 }
Cache object: 90108a508bd8a583a601b5df0f2048c1
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