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/9.2/sys/kern/kern_sig.c 253373 2013-07-15 23:12:42Z gavin $"); 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/systm.h> 48 #include <sys/signalvar.h> 49 #include <sys/vnode.h> 50 #include <sys/acct.h> 51 #include <sys/capability.h> 52 #include <sys/condvar.h> 53 #include <sys/event.h> 54 #include <sys/fcntl.h> 55 #include <sys/imgact.h> 56 #include <sys/kernel.h> 57 #include <sys/ktr.h> 58 #include <sys/ktrace.h> 59 #include <sys/lock.h> 60 #include <sys/malloc.h> 61 #include <sys/mutex.h> 62 #include <sys/namei.h> 63 #include <sys/proc.h> 64 #include <sys/procdesc.h> 65 #include <sys/posix4.h> 66 #include <sys/pioctl.h> 67 #include <sys/racct.h> 68 #include <sys/resourcevar.h> 69 #include <sys/sdt.h> 70 #include <sys/sbuf.h> 71 #include <sys/sleepqueue.h> 72 #include <sys/smp.h> 73 #include <sys/stat.h> 74 #include <sys/sx.h> 75 #include <sys/syscallsubr.h> 76 #include <sys/sysctl.h> 77 #include <sys/sysent.h> 78 #include <sys/syslog.h> 79 #include <sys/sysproto.h> 80 #include <sys/timers.h> 81 #include <sys/unistd.h> 82 #include <sys/wait.h> 83 #include <vm/vm.h> 84 #include <vm/vm_extern.h> 85 #include <vm/uma.h> 86 87 #include <sys/jail.h> 88 89 #include <machine/cpu.h> 90 91 #include <security/audit/audit.h> 92 93 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 94 95 SDT_PROVIDER_DECLARE(proc); 96 SDT_PROBE_DEFINE(proc, kernel, , signal_send, signal-send); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 99 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 100 SDT_PROBE_DEFINE(proc, kernel, , signal_clear, signal-clear); 101 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 102 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 103 SDT_PROBE_DEFINE(proc, kernel, , signal_discard, signal-discard); 104 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 105 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 106 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 107 108 static int coredump(struct thread *); 109 static char *expand_name(const char *, uid_t, pid_t, struct thread *, int); 110 static int killpg1(struct thread *td, int sig, int pgid, int all, 111 ksiginfo_t *ksi); 112 static int issignal(struct thread *td, int stop_allowed); 113 static int sigprop(int sig); 114 static void tdsigwakeup(struct thread *, int, sig_t, int); 115 static void sig_suspend_threads(struct thread *, struct proc *, int); 116 static int filt_sigattach(struct knote *kn); 117 static void filt_sigdetach(struct knote *kn); 118 static int filt_signal(struct knote *kn, long hint); 119 static struct thread *sigtd(struct proc *p, int sig, int prop); 120 static void sigqueue_start(void); 121 122 static uma_zone_t ksiginfo_zone = NULL; 123 struct filterops sig_filtops = { 124 .f_isfd = 0, 125 .f_attach = filt_sigattach, 126 .f_detach = filt_sigdetach, 127 .f_event = filt_signal, 128 }; 129 130 static int kern_logsigexit = 1; 131 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 132 &kern_logsigexit, 0, 133 "Log processes quitting on abnormal signals to syslog(3)"); 134 135 static int kern_forcesigexit = 1; 136 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 137 &kern_forcesigexit, 0, "Force trap signal to be handled"); 138 139 static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 140 "POSIX real time signal"); 141 142 static int max_pending_per_proc = 128; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 144 &max_pending_per_proc, 0, "Max pending signals per proc"); 145 146 static int preallocate_siginfo = 1024; 147 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 148 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 149 &preallocate_siginfo, 0, "Preallocated signal memory size"); 150 151 static int signal_overflow = 0; 152 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 153 &signal_overflow, 0, "Number of signals overflew"); 154 155 static int signal_alloc_fail = 0; 156 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 157 &signal_alloc_fail, 0, "signals failed to be allocated"); 158 159 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 160 161 /* 162 * Policy -- Can ucred cr1 send SIGIO to process cr2? 163 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 164 * in the right situations. 165 */ 166 #define CANSIGIO(cr1, cr2) \ 167 ((cr1)->cr_uid == 0 || \ 168 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 169 (cr1)->cr_uid == (cr2)->cr_ruid || \ 170 (cr1)->cr_ruid == (cr2)->cr_uid || \ 171 (cr1)->cr_uid == (cr2)->cr_uid) 172 173 static int sugid_coredump; 174 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 175 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 176 177 static int do_coredump = 1; 178 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 179 &do_coredump, 0, "Enable/Disable coredumps"); 180 181 static int set_core_nodump_flag = 0; 182 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 183 0, "Enable setting the NODUMP flag on coredump files"); 184 185 /* 186 * Signal properties and actions. 187 * The array below categorizes the signals and their default actions 188 * according to the following properties: 189 */ 190 #define SA_KILL 0x01 /* terminates process by default */ 191 #define SA_CORE 0x02 /* ditto and coredumps */ 192 #define SA_STOP 0x04 /* suspend process */ 193 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 194 #define SA_IGNORE 0x10 /* ignore by default */ 195 #define SA_CONT 0x20 /* continue if suspended */ 196 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 197 #define SA_PROC 0x80 /* deliverable to any thread */ 198 199 static int sigproptbl[NSIG] = { 200 SA_KILL|SA_PROC, /* SIGHUP */ 201 SA_KILL|SA_PROC, /* SIGINT */ 202 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 203 SA_KILL|SA_CORE, /* SIGILL */ 204 SA_KILL|SA_CORE, /* SIGTRAP */ 205 SA_KILL|SA_CORE, /* SIGABRT */ 206 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 207 SA_KILL|SA_CORE, /* SIGFPE */ 208 SA_KILL|SA_PROC, /* SIGKILL */ 209 SA_KILL|SA_CORE, /* SIGBUS */ 210 SA_KILL|SA_CORE, /* SIGSEGV */ 211 SA_KILL|SA_CORE, /* SIGSYS */ 212 SA_KILL|SA_PROC, /* SIGPIPE */ 213 SA_KILL|SA_PROC, /* SIGALRM */ 214 SA_KILL|SA_PROC, /* SIGTERM */ 215 SA_IGNORE|SA_PROC, /* SIGURG */ 216 SA_STOP|SA_PROC, /* SIGSTOP */ 217 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 218 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 219 SA_IGNORE|SA_PROC, /* SIGCHLD */ 220 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 221 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 222 SA_IGNORE|SA_PROC, /* SIGIO */ 223 SA_KILL, /* SIGXCPU */ 224 SA_KILL, /* SIGXFSZ */ 225 SA_KILL|SA_PROC, /* SIGVTALRM */ 226 SA_KILL|SA_PROC, /* SIGPROF */ 227 SA_IGNORE|SA_PROC, /* SIGWINCH */ 228 SA_IGNORE|SA_PROC, /* SIGINFO */ 229 SA_KILL|SA_PROC, /* SIGUSR1 */ 230 SA_KILL|SA_PROC, /* SIGUSR2 */ 231 }; 232 233 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 234 235 static void 236 sigqueue_start(void) 237 { 238 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 239 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 240 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 241 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 242 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 243 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 244 } 245 246 ksiginfo_t * 247 ksiginfo_alloc(int wait) 248 { 249 int flags; 250 251 flags = M_ZERO; 252 if (! wait) 253 flags |= M_NOWAIT; 254 if (ksiginfo_zone != NULL) 255 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 256 return (NULL); 257 } 258 259 void 260 ksiginfo_free(ksiginfo_t *ksi) 261 { 262 uma_zfree(ksiginfo_zone, ksi); 263 } 264 265 static __inline int 266 ksiginfo_tryfree(ksiginfo_t *ksi) 267 { 268 if (!(ksi->ksi_flags & KSI_EXT)) { 269 uma_zfree(ksiginfo_zone, ksi); 270 return (1); 271 } 272 return (0); 273 } 274 275 void 276 sigqueue_init(sigqueue_t *list, struct proc *p) 277 { 278 SIGEMPTYSET(list->sq_signals); 279 SIGEMPTYSET(list->sq_kill); 280 TAILQ_INIT(&list->sq_list); 281 list->sq_proc = p; 282 list->sq_flags = SQ_INIT; 283 } 284 285 /* 286 * Get a signal's ksiginfo. 287 * Return: 288 * 0 - signal not found 289 * others - signal number 290 */ 291 static int 292 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 293 { 294 struct proc *p = sq->sq_proc; 295 struct ksiginfo *ksi, *next; 296 int count = 0; 297 298 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 299 300 if (!SIGISMEMBER(sq->sq_signals, signo)) 301 return (0); 302 303 if (SIGISMEMBER(sq->sq_kill, signo)) { 304 count++; 305 SIGDELSET(sq->sq_kill, signo); 306 } 307 308 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 309 if (ksi->ksi_signo == signo) { 310 if (count == 0) { 311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 312 ksi->ksi_sigq = NULL; 313 ksiginfo_copy(ksi, si); 314 if (ksiginfo_tryfree(ksi) && p != NULL) 315 p->p_pendingcnt--; 316 } 317 if (++count > 1) 318 break; 319 } 320 } 321 322 if (count <= 1) 323 SIGDELSET(sq->sq_signals, signo); 324 si->ksi_signo = signo; 325 return (signo); 326 } 327 328 void 329 sigqueue_take(ksiginfo_t *ksi) 330 { 331 struct ksiginfo *kp; 332 struct proc *p; 333 sigqueue_t *sq; 334 335 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 336 return; 337 338 p = sq->sq_proc; 339 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 340 ksi->ksi_sigq = NULL; 341 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 342 p->p_pendingcnt--; 343 344 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 345 kp = TAILQ_NEXT(kp, ksi_link)) { 346 if (kp->ksi_signo == ksi->ksi_signo) 347 break; 348 } 349 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 350 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 351 } 352 353 static int 354 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 355 { 356 struct proc *p = sq->sq_proc; 357 struct ksiginfo *ksi; 358 int ret = 0; 359 360 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 361 362 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 363 SIGADDSET(sq->sq_kill, signo); 364 goto out_set_bit; 365 } 366 367 /* directly insert the ksi, don't copy it */ 368 if (si->ksi_flags & KSI_INS) { 369 if (si->ksi_flags & KSI_HEAD) 370 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 371 else 372 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 373 si->ksi_sigq = sq; 374 goto out_set_bit; 375 } 376 377 if (__predict_false(ksiginfo_zone == NULL)) { 378 SIGADDSET(sq->sq_kill, signo); 379 goto out_set_bit; 380 } 381 382 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 383 signal_overflow++; 384 ret = EAGAIN; 385 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 386 signal_alloc_fail++; 387 ret = EAGAIN; 388 } else { 389 if (p != NULL) 390 p->p_pendingcnt++; 391 ksiginfo_copy(si, ksi); 392 ksi->ksi_signo = signo; 393 if (si->ksi_flags & KSI_HEAD) 394 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 395 else 396 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 397 ksi->ksi_sigq = sq; 398 } 399 400 if ((si->ksi_flags & KSI_TRAP) != 0 || 401 (si->ksi_flags & KSI_SIGQ) == 0) { 402 if (ret != 0) 403 SIGADDSET(sq->sq_kill, signo); 404 ret = 0; 405 goto out_set_bit; 406 } 407 408 if (ret != 0) 409 return (ret); 410 411 out_set_bit: 412 SIGADDSET(sq->sq_signals, signo); 413 return (ret); 414 } 415 416 void 417 sigqueue_flush(sigqueue_t *sq) 418 { 419 struct proc *p = sq->sq_proc; 420 ksiginfo_t *ksi; 421 422 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 423 424 if (p != NULL) 425 PROC_LOCK_ASSERT(p, MA_OWNED); 426 427 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 428 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 429 ksi->ksi_sigq = NULL; 430 if (ksiginfo_tryfree(ksi) && p != NULL) 431 p->p_pendingcnt--; 432 } 433 434 SIGEMPTYSET(sq->sq_signals); 435 SIGEMPTYSET(sq->sq_kill); 436 } 437 438 static void 439 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 440 { 441 sigset_t tmp; 442 struct proc *p1, *p2; 443 ksiginfo_t *ksi, *next; 444 445 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 446 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 447 p1 = src->sq_proc; 448 p2 = dst->sq_proc; 449 /* Move siginfo to target list */ 450 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 451 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 452 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 453 if (p1 != NULL) 454 p1->p_pendingcnt--; 455 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 456 ksi->ksi_sigq = dst; 457 if (p2 != NULL) 458 p2->p_pendingcnt++; 459 } 460 } 461 462 /* Move pending bits to target list */ 463 tmp = src->sq_kill; 464 SIGSETAND(tmp, *set); 465 SIGSETOR(dst->sq_kill, tmp); 466 SIGSETNAND(src->sq_kill, tmp); 467 468 tmp = src->sq_signals; 469 SIGSETAND(tmp, *set); 470 SIGSETOR(dst->sq_signals, tmp); 471 SIGSETNAND(src->sq_signals, tmp); 472 } 473 474 #if 0 475 static void 476 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 477 { 478 sigset_t set; 479 480 SIGEMPTYSET(set); 481 SIGADDSET(set, signo); 482 sigqueue_move_set(src, dst, &set); 483 } 484 #endif 485 486 static void 487 sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 488 { 489 struct proc *p = sq->sq_proc; 490 ksiginfo_t *ksi, *next; 491 492 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 493 494 /* Remove siginfo queue */ 495 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 496 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 497 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 498 ksi->ksi_sigq = NULL; 499 if (ksiginfo_tryfree(ksi) && p != NULL) 500 p->p_pendingcnt--; 501 } 502 } 503 SIGSETNAND(sq->sq_kill, *set); 504 SIGSETNAND(sq->sq_signals, *set); 505 } 506 507 void 508 sigqueue_delete(sigqueue_t *sq, int signo) 509 { 510 sigset_t set; 511 512 SIGEMPTYSET(set); 513 SIGADDSET(set, signo); 514 sigqueue_delete_set(sq, &set); 515 } 516 517 /* Remove a set of signals for a process */ 518 static void 519 sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 520 { 521 sigqueue_t worklist; 522 struct thread *td0; 523 524 PROC_LOCK_ASSERT(p, MA_OWNED); 525 526 sigqueue_init(&worklist, NULL); 527 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 528 529 FOREACH_THREAD_IN_PROC(p, td0) 530 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 531 532 sigqueue_flush(&worklist); 533 } 534 535 void 536 sigqueue_delete_proc(struct proc *p, int signo) 537 { 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set_proc(p, &set); 543 } 544 545 static void 546 sigqueue_delete_stopmask_proc(struct proc *p) 547 { 548 sigset_t set; 549 550 SIGEMPTYSET(set); 551 SIGADDSET(set, SIGSTOP); 552 SIGADDSET(set, SIGTSTP); 553 SIGADDSET(set, SIGTTIN); 554 SIGADDSET(set, SIGTTOU); 555 sigqueue_delete_set_proc(p, &set); 556 } 557 558 /* 559 * Determine signal that should be delivered to process p, the current 560 * process, 0 if none. If there is a pending stop signal with default 561 * action, the process stops in issignal(). 562 */ 563 int 564 cursig(struct thread *td, int stop_allowed) 565 { 566 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 567 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 568 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 569 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 570 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 571 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 572 } 573 574 /* 575 * Arrange for ast() to handle unmasked pending signals on return to user 576 * mode. This must be called whenever a signal is added to td_sigqueue or 577 * unmasked in td_sigmask. 578 */ 579 void 580 signotify(struct thread *td) 581 { 582 struct proc *p; 583 584 p = td->td_proc; 585 586 PROC_LOCK_ASSERT(p, MA_OWNED); 587 588 if (SIGPENDING(td)) { 589 thread_lock(td); 590 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 591 thread_unlock(td); 592 } 593 } 594 595 int 596 sigonstack(size_t sp) 597 { 598 struct thread *td = curthread; 599 600 return ((td->td_pflags & TDP_ALTSTACK) ? 601 #if defined(COMPAT_43) 602 ((td->td_sigstk.ss_size == 0) ? 603 (td->td_sigstk.ss_flags & SS_ONSTACK) : 604 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 605 #else 606 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 607 #endif 608 : 0); 609 } 610 611 static __inline int 612 sigprop(int sig) 613 { 614 615 if (sig > 0 && sig < NSIG) 616 return (sigproptbl[_SIG_IDX(sig)]); 617 return (0); 618 } 619 620 int 621 sig_ffs(sigset_t *set) 622 { 623 int i; 624 625 for (i = 0; i < _SIG_WORDS; i++) 626 if (set->__bits[i]) 627 return (ffs(set->__bits[i]) + (i * 32)); 628 return (0); 629 } 630 631 /* 632 * kern_sigaction 633 * sigaction 634 * freebsd4_sigaction 635 * osigaction 636 */ 637 int 638 kern_sigaction(td, sig, act, oact, flags) 639 struct thread *td; 640 register int sig; 641 struct sigaction *act, *oact; 642 int flags; 643 { 644 struct sigacts *ps; 645 struct proc *p = td->td_proc; 646 647 if (!_SIG_VALID(sig)) 648 return (EINVAL); 649 650 PROC_LOCK(p); 651 ps = p->p_sigacts; 652 mtx_lock(&ps->ps_mtx); 653 if (oact) { 654 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 655 oact->sa_flags = 0; 656 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 657 oact->sa_flags |= SA_ONSTACK; 658 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 659 oact->sa_flags |= SA_RESTART; 660 if (SIGISMEMBER(ps->ps_sigreset, sig)) 661 oact->sa_flags |= SA_RESETHAND; 662 if (SIGISMEMBER(ps->ps_signodefer, sig)) 663 oact->sa_flags |= SA_NODEFER; 664 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 665 oact->sa_flags |= SA_SIGINFO; 666 oact->sa_sigaction = 667 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 668 } else 669 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 670 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 671 oact->sa_flags |= SA_NOCLDSTOP; 672 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 673 oact->sa_flags |= SA_NOCLDWAIT; 674 } 675 if (act) { 676 if ((sig == SIGKILL || sig == SIGSTOP) && 677 act->sa_handler != SIG_DFL) { 678 mtx_unlock(&ps->ps_mtx); 679 PROC_UNLOCK(p); 680 return (EINVAL); 681 } 682 683 /* 684 * Change setting atomically. 685 */ 686 687 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 688 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 689 if (act->sa_flags & SA_SIGINFO) { 690 ps->ps_sigact[_SIG_IDX(sig)] = 691 (__sighandler_t *)act->sa_sigaction; 692 SIGADDSET(ps->ps_siginfo, sig); 693 } else { 694 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 695 SIGDELSET(ps->ps_siginfo, sig); 696 } 697 if (!(act->sa_flags & SA_RESTART)) 698 SIGADDSET(ps->ps_sigintr, sig); 699 else 700 SIGDELSET(ps->ps_sigintr, sig); 701 if (act->sa_flags & SA_ONSTACK) 702 SIGADDSET(ps->ps_sigonstack, sig); 703 else 704 SIGDELSET(ps->ps_sigonstack, sig); 705 if (act->sa_flags & SA_RESETHAND) 706 SIGADDSET(ps->ps_sigreset, sig); 707 else 708 SIGDELSET(ps->ps_sigreset, sig); 709 if (act->sa_flags & SA_NODEFER) 710 SIGADDSET(ps->ps_signodefer, sig); 711 else 712 SIGDELSET(ps->ps_signodefer, sig); 713 if (sig == SIGCHLD) { 714 if (act->sa_flags & SA_NOCLDSTOP) 715 ps->ps_flag |= PS_NOCLDSTOP; 716 else 717 ps->ps_flag &= ~PS_NOCLDSTOP; 718 if (act->sa_flags & SA_NOCLDWAIT) { 719 /* 720 * Paranoia: since SA_NOCLDWAIT is implemented 721 * by reparenting the dying child to PID 1 (and 722 * trust it to reap the zombie), PID 1 itself 723 * is forbidden to set SA_NOCLDWAIT. 724 */ 725 if (p->p_pid == 1) 726 ps->ps_flag &= ~PS_NOCLDWAIT; 727 else 728 ps->ps_flag |= PS_NOCLDWAIT; 729 } else 730 ps->ps_flag &= ~PS_NOCLDWAIT; 731 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 732 ps->ps_flag |= PS_CLDSIGIGN; 733 else 734 ps->ps_flag &= ~PS_CLDSIGIGN; 735 } 736 /* 737 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 738 * and for signals set to SIG_DFL where the default is to 739 * ignore. However, don't put SIGCONT in ps_sigignore, as we 740 * have to restart the process. 741 */ 742 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 743 (sigprop(sig) & SA_IGNORE && 744 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 745 /* never to be seen again */ 746 sigqueue_delete_proc(p, sig); 747 if (sig != SIGCONT) 748 /* easier in psignal */ 749 SIGADDSET(ps->ps_sigignore, sig); 750 SIGDELSET(ps->ps_sigcatch, sig); 751 } else { 752 SIGDELSET(ps->ps_sigignore, sig); 753 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 754 SIGDELSET(ps->ps_sigcatch, sig); 755 else 756 SIGADDSET(ps->ps_sigcatch, sig); 757 } 758 #ifdef COMPAT_FREEBSD4 759 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 760 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 761 (flags & KSA_FREEBSD4) == 0) 762 SIGDELSET(ps->ps_freebsd4, sig); 763 else 764 SIGADDSET(ps->ps_freebsd4, sig); 765 #endif 766 #ifdef COMPAT_43 767 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 768 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 769 (flags & KSA_OSIGSET) == 0) 770 SIGDELSET(ps->ps_osigset, sig); 771 else 772 SIGADDSET(ps->ps_osigset, sig); 773 #endif 774 } 775 mtx_unlock(&ps->ps_mtx); 776 PROC_UNLOCK(p); 777 return (0); 778 } 779 780 #ifndef _SYS_SYSPROTO_H_ 781 struct sigaction_args { 782 int sig; 783 struct sigaction *act; 784 struct sigaction *oact; 785 }; 786 #endif 787 int 788 sys_sigaction(td, uap) 789 struct thread *td; 790 register struct sigaction_args *uap; 791 { 792 struct sigaction act, oact; 793 register struct sigaction *actp, *oactp; 794 int error; 795 796 actp = (uap->act != NULL) ? &act : NULL; 797 oactp = (uap->oact != NULL) ? &oact : NULL; 798 if (actp) { 799 error = copyin(uap->act, actp, sizeof(act)); 800 if (error) 801 return (error); 802 } 803 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 804 if (oactp && !error) 805 error = copyout(oactp, uap->oact, sizeof(oact)); 806 return (error); 807 } 808 809 #ifdef COMPAT_FREEBSD4 810 #ifndef _SYS_SYSPROTO_H_ 811 struct freebsd4_sigaction_args { 812 int sig; 813 struct sigaction *act; 814 struct sigaction *oact; 815 }; 816 #endif 817 int 818 freebsd4_sigaction(td, uap) 819 struct thread *td; 820 register struct freebsd4_sigaction_args *uap; 821 { 822 struct sigaction act, oact; 823 register struct sigaction *actp, *oactp; 824 int error; 825 826 827 actp = (uap->act != NULL) ? &act : NULL; 828 oactp = (uap->oact != NULL) ? &oact : NULL; 829 if (actp) { 830 error = copyin(uap->act, actp, sizeof(act)); 831 if (error) 832 return (error); 833 } 834 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 835 if (oactp && !error) 836 error = copyout(oactp, uap->oact, sizeof(oact)); 837 return (error); 838 } 839 #endif /* COMAPT_FREEBSD4 */ 840 841 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 842 #ifndef _SYS_SYSPROTO_H_ 843 struct osigaction_args { 844 int signum; 845 struct osigaction *nsa; 846 struct osigaction *osa; 847 }; 848 #endif 849 int 850 osigaction(td, uap) 851 struct thread *td; 852 register struct osigaction_args *uap; 853 { 854 struct osigaction sa; 855 struct sigaction nsa, osa; 856 register struct sigaction *nsap, *osap; 857 int error; 858 859 if (uap->signum <= 0 || uap->signum >= ONSIG) 860 return (EINVAL); 861 862 nsap = (uap->nsa != NULL) ? &nsa : NULL; 863 osap = (uap->osa != NULL) ? &osa : NULL; 864 865 if (nsap) { 866 error = copyin(uap->nsa, &sa, sizeof(sa)); 867 if (error) 868 return (error); 869 nsap->sa_handler = sa.sa_handler; 870 nsap->sa_flags = sa.sa_flags; 871 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 872 } 873 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 874 if (osap && !error) { 875 sa.sa_handler = osap->sa_handler; 876 sa.sa_flags = osap->sa_flags; 877 SIG2OSIG(osap->sa_mask, sa.sa_mask); 878 error = copyout(&sa, uap->osa, sizeof(sa)); 879 } 880 return (error); 881 } 882 883 #if !defined(__i386__) 884 /* Avoid replicating the same stub everywhere */ 885 int 886 osigreturn(td, uap) 887 struct thread *td; 888 struct osigreturn_args *uap; 889 { 890 891 return (nosys(td, (struct nosys_args *)uap)); 892 } 893 #endif 894 #endif /* COMPAT_43 */ 895 896 /* 897 * Initialize signal state for process 0; 898 * set to ignore signals that are ignored by default. 899 */ 900 void 901 siginit(p) 902 struct proc *p; 903 { 904 register int i; 905 struct sigacts *ps; 906 907 PROC_LOCK(p); 908 ps = p->p_sigacts; 909 mtx_lock(&ps->ps_mtx); 910 for (i = 1; i <= NSIG; i++) 911 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 912 SIGADDSET(ps->ps_sigignore, i); 913 mtx_unlock(&ps->ps_mtx); 914 PROC_UNLOCK(p); 915 } 916 917 /* 918 * Reset signals for an exec of the specified process. 919 */ 920 void 921 execsigs(struct proc *p) 922 { 923 struct sigacts *ps; 924 int sig; 925 struct thread *td; 926 927 /* 928 * Reset caught signals. Held signals remain held 929 * through td_sigmask (unless they were caught, 930 * and are now ignored by default). 931 */ 932 PROC_LOCK_ASSERT(p, MA_OWNED); 933 td = FIRST_THREAD_IN_PROC(p); 934 ps = p->p_sigacts; 935 mtx_lock(&ps->ps_mtx); 936 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 937 sig = sig_ffs(&ps->ps_sigcatch); 938 SIGDELSET(ps->ps_sigcatch, sig); 939 if (sigprop(sig) & SA_IGNORE) { 940 if (sig != SIGCONT) 941 SIGADDSET(ps->ps_sigignore, sig); 942 sigqueue_delete_proc(p, sig); 943 } 944 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 945 } 946 /* 947 * Reset stack state to the user stack. 948 * Clear set of signals caught on the signal stack. 949 */ 950 td->td_sigstk.ss_flags = SS_DISABLE; 951 td->td_sigstk.ss_size = 0; 952 td->td_sigstk.ss_sp = 0; 953 td->td_pflags &= ~TDP_ALTSTACK; 954 /* 955 * Reset no zombies if child dies flag as Solaris does. 956 */ 957 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 958 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 959 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 960 mtx_unlock(&ps->ps_mtx); 961 } 962 963 /* 964 * kern_sigprocmask() 965 * 966 * Manipulate signal mask. 967 */ 968 int 969 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 970 int flags) 971 { 972 sigset_t new_block, oset1; 973 struct proc *p; 974 int error; 975 976 p = td->td_proc; 977 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 978 PROC_LOCK(p); 979 if (oset != NULL) 980 *oset = td->td_sigmask; 981 982 error = 0; 983 if (set != NULL) { 984 switch (how) { 985 case SIG_BLOCK: 986 SIG_CANTMASK(*set); 987 oset1 = td->td_sigmask; 988 SIGSETOR(td->td_sigmask, *set); 989 new_block = td->td_sigmask; 990 SIGSETNAND(new_block, oset1); 991 break; 992 case SIG_UNBLOCK: 993 SIGSETNAND(td->td_sigmask, *set); 994 signotify(td); 995 goto out; 996 case SIG_SETMASK: 997 SIG_CANTMASK(*set); 998 oset1 = td->td_sigmask; 999 if (flags & SIGPROCMASK_OLD) 1000 SIGSETLO(td->td_sigmask, *set); 1001 else 1002 td->td_sigmask = *set; 1003 new_block = td->td_sigmask; 1004 SIGSETNAND(new_block, oset1); 1005 signotify(td); 1006 break; 1007 default: 1008 error = EINVAL; 1009 goto out; 1010 } 1011 1012 /* 1013 * The new_block set contains signals that were not previously 1014 * blocked, but are blocked now. 1015 * 1016 * In case we block any signal that was not previously blocked 1017 * for td, and process has the signal pending, try to schedule 1018 * signal delivery to some thread that does not block the 1019 * signal, possibly waking it up. 1020 */ 1021 if (p->p_numthreads != 1) 1022 reschedule_signals(p, new_block, flags); 1023 } 1024 1025 out: 1026 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1027 PROC_UNLOCK(p); 1028 return (error); 1029 } 1030 1031 #ifndef _SYS_SYSPROTO_H_ 1032 struct sigprocmask_args { 1033 int how; 1034 const sigset_t *set; 1035 sigset_t *oset; 1036 }; 1037 #endif 1038 int 1039 sys_sigprocmask(td, uap) 1040 register struct thread *td; 1041 struct sigprocmask_args *uap; 1042 { 1043 sigset_t set, oset; 1044 sigset_t *setp, *osetp; 1045 int error; 1046 1047 setp = (uap->set != NULL) ? &set : NULL; 1048 osetp = (uap->oset != NULL) ? &oset : NULL; 1049 if (setp) { 1050 error = copyin(uap->set, setp, sizeof(set)); 1051 if (error) 1052 return (error); 1053 } 1054 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1055 if (osetp && !error) { 1056 error = copyout(osetp, uap->oset, sizeof(oset)); 1057 } 1058 return (error); 1059 } 1060 1061 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1062 #ifndef _SYS_SYSPROTO_H_ 1063 struct osigprocmask_args { 1064 int how; 1065 osigset_t mask; 1066 }; 1067 #endif 1068 int 1069 osigprocmask(td, uap) 1070 register struct thread *td; 1071 struct osigprocmask_args *uap; 1072 { 1073 sigset_t set, oset; 1074 int error; 1075 1076 OSIG2SIG(uap->mask, set); 1077 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1078 SIG2OSIG(oset, td->td_retval[0]); 1079 return (error); 1080 } 1081 #endif /* COMPAT_43 */ 1082 1083 int 1084 sys_sigwait(struct thread *td, struct sigwait_args *uap) 1085 { 1086 ksiginfo_t ksi; 1087 sigset_t set; 1088 int error; 1089 1090 error = copyin(uap->set, &set, sizeof(set)); 1091 if (error) { 1092 td->td_retval[0] = error; 1093 return (0); 1094 } 1095 1096 error = kern_sigtimedwait(td, set, &ksi, NULL); 1097 if (error) { 1098 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1099 error = ERESTART; 1100 if (error == ERESTART) 1101 return (error); 1102 td->td_retval[0] = error; 1103 return (0); 1104 } 1105 1106 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1107 td->td_retval[0] = error; 1108 return (0); 1109 } 1110 1111 int 1112 sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1113 { 1114 struct timespec ts; 1115 struct timespec *timeout; 1116 sigset_t set; 1117 ksiginfo_t ksi; 1118 int error; 1119 1120 if (uap->timeout) { 1121 error = copyin(uap->timeout, &ts, sizeof(ts)); 1122 if (error) 1123 return (error); 1124 1125 timeout = &ts; 1126 } else 1127 timeout = NULL; 1128 1129 error = copyin(uap->set, &set, sizeof(set)); 1130 if (error) 1131 return (error); 1132 1133 error = kern_sigtimedwait(td, set, &ksi, timeout); 1134 if (error) 1135 return (error); 1136 1137 if (uap->info) 1138 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1139 1140 if (error == 0) 1141 td->td_retval[0] = ksi.ksi_signo; 1142 return (error); 1143 } 1144 1145 int 1146 sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1147 { 1148 ksiginfo_t ksi; 1149 sigset_t set; 1150 int error; 1151 1152 error = copyin(uap->set, &set, sizeof(set)); 1153 if (error) 1154 return (error); 1155 1156 error = kern_sigtimedwait(td, set, &ksi, NULL); 1157 if (error) 1158 return (error); 1159 1160 if (uap->info) 1161 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1162 1163 if (error == 0) 1164 td->td_retval[0] = ksi.ksi_signo; 1165 return (error); 1166 } 1167 1168 int 1169 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1170 struct timespec *timeout) 1171 { 1172 struct sigacts *ps; 1173 sigset_t saved_mask, new_block; 1174 struct proc *p; 1175 int error, sig, timo, timevalid = 0; 1176 struct timespec rts, ets, ts; 1177 struct timeval tv; 1178 1179 p = td->td_proc; 1180 error = 0; 1181 ets.tv_sec = 0; 1182 ets.tv_nsec = 0; 1183 1184 if (timeout != NULL) { 1185 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1186 timevalid = 1; 1187 getnanouptime(&rts); 1188 ets = rts; 1189 timespecadd(&ets, timeout); 1190 } 1191 } 1192 ksiginfo_init(ksi); 1193 /* Some signals can not be waited for. */ 1194 SIG_CANTMASK(waitset); 1195 ps = p->p_sigacts; 1196 PROC_LOCK(p); 1197 saved_mask = td->td_sigmask; 1198 SIGSETNAND(td->td_sigmask, waitset); 1199 for (;;) { 1200 mtx_lock(&ps->ps_mtx); 1201 sig = cursig(td, SIG_STOP_ALLOWED); 1202 mtx_unlock(&ps->ps_mtx); 1203 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1204 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1205 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1206 error = 0; 1207 break; 1208 } 1209 } 1210 1211 if (error != 0) 1212 break; 1213 1214 /* 1215 * POSIX says this must be checked after looking for pending 1216 * signals. 1217 */ 1218 if (timeout != NULL) { 1219 if (!timevalid) { 1220 error = EINVAL; 1221 break; 1222 } 1223 getnanouptime(&rts); 1224 if (timespeccmp(&rts, &ets, >=)) { 1225 error = EAGAIN; 1226 break; 1227 } 1228 ts = ets; 1229 timespecsub(&ts, &rts); 1230 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1231 timo = tvtohz(&tv); 1232 } else { 1233 timo = 0; 1234 } 1235 1236 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1237 1238 if (timeout != NULL) { 1239 if (error == ERESTART) { 1240 /* Timeout can not be restarted. */ 1241 error = EINTR; 1242 } else if (error == EAGAIN) { 1243 /* We will calculate timeout by ourself. */ 1244 error = 0; 1245 } 1246 } 1247 } 1248 1249 new_block = saved_mask; 1250 SIGSETNAND(new_block, td->td_sigmask); 1251 td->td_sigmask = saved_mask; 1252 /* 1253 * Fewer signals can be delivered to us, reschedule signal 1254 * notification. 1255 */ 1256 if (p->p_numthreads != 1) 1257 reschedule_signals(p, new_block, 0); 1258 1259 if (error == 0) { 1260 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1261 1262 if (ksi->ksi_code == SI_TIMER) 1263 itimer_accept(p, ksi->ksi_timerid, ksi); 1264 1265 #ifdef KTRACE 1266 if (KTRPOINT(td, KTR_PSIG)) { 1267 sig_t action; 1268 1269 mtx_lock(&ps->ps_mtx); 1270 action = ps->ps_sigact[_SIG_IDX(sig)]; 1271 mtx_unlock(&ps->ps_mtx); 1272 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1273 } 1274 #endif 1275 if (sig == SIGKILL) 1276 sigexit(td, sig); 1277 } 1278 PROC_UNLOCK(p); 1279 return (error); 1280 } 1281 1282 #ifndef _SYS_SYSPROTO_H_ 1283 struct sigpending_args { 1284 sigset_t *set; 1285 }; 1286 #endif 1287 int 1288 sys_sigpending(td, uap) 1289 struct thread *td; 1290 struct sigpending_args *uap; 1291 { 1292 struct proc *p = td->td_proc; 1293 sigset_t pending; 1294 1295 PROC_LOCK(p); 1296 pending = p->p_sigqueue.sq_signals; 1297 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1298 PROC_UNLOCK(p); 1299 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1300 } 1301 1302 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1303 #ifndef _SYS_SYSPROTO_H_ 1304 struct osigpending_args { 1305 int dummy; 1306 }; 1307 #endif 1308 int 1309 osigpending(td, uap) 1310 struct thread *td; 1311 struct osigpending_args *uap; 1312 { 1313 struct proc *p = td->td_proc; 1314 sigset_t pending; 1315 1316 PROC_LOCK(p); 1317 pending = p->p_sigqueue.sq_signals; 1318 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1319 PROC_UNLOCK(p); 1320 SIG2OSIG(pending, td->td_retval[0]); 1321 return (0); 1322 } 1323 #endif /* COMPAT_43 */ 1324 1325 #if defined(COMPAT_43) 1326 /* 1327 * Generalized interface signal handler, 4.3-compatible. 1328 */ 1329 #ifndef _SYS_SYSPROTO_H_ 1330 struct osigvec_args { 1331 int signum; 1332 struct sigvec *nsv; 1333 struct sigvec *osv; 1334 }; 1335 #endif 1336 /* ARGSUSED */ 1337 int 1338 osigvec(td, uap) 1339 struct thread *td; 1340 register struct osigvec_args *uap; 1341 { 1342 struct sigvec vec; 1343 struct sigaction nsa, osa; 1344 register struct sigaction *nsap, *osap; 1345 int error; 1346 1347 if (uap->signum <= 0 || uap->signum >= ONSIG) 1348 return (EINVAL); 1349 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1350 osap = (uap->osv != NULL) ? &osa : NULL; 1351 if (nsap) { 1352 error = copyin(uap->nsv, &vec, sizeof(vec)); 1353 if (error) 1354 return (error); 1355 nsap->sa_handler = vec.sv_handler; 1356 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1357 nsap->sa_flags = vec.sv_flags; 1358 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1359 } 1360 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1361 if (osap && !error) { 1362 vec.sv_handler = osap->sa_handler; 1363 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1364 vec.sv_flags = osap->sa_flags; 1365 vec.sv_flags &= ~SA_NOCLDWAIT; 1366 vec.sv_flags ^= SA_RESTART; 1367 error = copyout(&vec, uap->osv, sizeof(vec)); 1368 } 1369 return (error); 1370 } 1371 1372 #ifndef _SYS_SYSPROTO_H_ 1373 struct osigblock_args { 1374 int mask; 1375 }; 1376 #endif 1377 int 1378 osigblock(td, uap) 1379 register struct thread *td; 1380 struct osigblock_args *uap; 1381 { 1382 sigset_t set, oset; 1383 1384 OSIG2SIG(uap->mask, set); 1385 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1386 SIG2OSIG(oset, td->td_retval[0]); 1387 return (0); 1388 } 1389 1390 #ifndef _SYS_SYSPROTO_H_ 1391 struct osigsetmask_args { 1392 int mask; 1393 }; 1394 #endif 1395 int 1396 osigsetmask(td, uap) 1397 struct thread *td; 1398 struct osigsetmask_args *uap; 1399 { 1400 sigset_t set, oset; 1401 1402 OSIG2SIG(uap->mask, set); 1403 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1404 SIG2OSIG(oset, td->td_retval[0]); 1405 return (0); 1406 } 1407 #endif /* COMPAT_43 */ 1408 1409 /* 1410 * Suspend calling thread until signal, providing mask to be set in the 1411 * meantime. 1412 */ 1413 #ifndef _SYS_SYSPROTO_H_ 1414 struct sigsuspend_args { 1415 const sigset_t *sigmask; 1416 }; 1417 #endif 1418 /* ARGSUSED */ 1419 int 1420 sys_sigsuspend(td, uap) 1421 struct thread *td; 1422 struct sigsuspend_args *uap; 1423 { 1424 sigset_t mask; 1425 int error; 1426 1427 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1428 if (error) 1429 return (error); 1430 return (kern_sigsuspend(td, mask)); 1431 } 1432 1433 int 1434 kern_sigsuspend(struct thread *td, sigset_t mask) 1435 { 1436 struct proc *p = td->td_proc; 1437 int has_sig, sig; 1438 1439 /* 1440 * When returning from sigsuspend, we want 1441 * the old mask to be restored after the 1442 * signal handler has finished. Thus, we 1443 * save it here and mark the sigacts structure 1444 * to indicate this. 1445 */ 1446 PROC_LOCK(p); 1447 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1448 SIGPROCMASK_PROC_LOCKED); 1449 td->td_pflags |= TDP_OLDMASK; 1450 1451 /* 1452 * Process signals now. Otherwise, we can get spurious wakeup 1453 * due to signal entered process queue, but delivered to other 1454 * thread. But sigsuspend should return only on signal 1455 * delivery. 1456 */ 1457 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1458 for (has_sig = 0; !has_sig;) { 1459 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1460 0) == 0) 1461 /* void */; 1462 thread_suspend_check(0); 1463 mtx_lock(&p->p_sigacts->ps_mtx); 1464 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1465 has_sig += postsig(sig); 1466 mtx_unlock(&p->p_sigacts->ps_mtx); 1467 } 1468 PROC_UNLOCK(p); 1469 td->td_errno = EINTR; 1470 td->td_pflags |= TDP_NERRNO; 1471 return (EJUSTRETURN); 1472 } 1473 1474 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1475 /* 1476 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1477 * convention: libc stub passes mask, not pointer, to save a copyin. 1478 */ 1479 #ifndef _SYS_SYSPROTO_H_ 1480 struct osigsuspend_args { 1481 osigset_t mask; 1482 }; 1483 #endif 1484 /* ARGSUSED */ 1485 int 1486 osigsuspend(td, uap) 1487 struct thread *td; 1488 struct osigsuspend_args *uap; 1489 { 1490 sigset_t mask; 1491 1492 OSIG2SIG(uap->mask, mask); 1493 return (kern_sigsuspend(td, mask)); 1494 } 1495 #endif /* COMPAT_43 */ 1496 1497 #if defined(COMPAT_43) 1498 #ifndef _SYS_SYSPROTO_H_ 1499 struct osigstack_args { 1500 struct sigstack *nss; 1501 struct sigstack *oss; 1502 }; 1503 #endif 1504 /* ARGSUSED */ 1505 int 1506 osigstack(td, uap) 1507 struct thread *td; 1508 register struct osigstack_args *uap; 1509 { 1510 struct sigstack nss, oss; 1511 int error = 0; 1512 1513 if (uap->nss != NULL) { 1514 error = copyin(uap->nss, &nss, sizeof(nss)); 1515 if (error) 1516 return (error); 1517 } 1518 oss.ss_sp = td->td_sigstk.ss_sp; 1519 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1520 if (uap->nss != NULL) { 1521 td->td_sigstk.ss_sp = nss.ss_sp; 1522 td->td_sigstk.ss_size = 0; 1523 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1524 td->td_pflags |= TDP_ALTSTACK; 1525 } 1526 if (uap->oss != NULL) 1527 error = copyout(&oss, uap->oss, sizeof(oss)); 1528 1529 return (error); 1530 } 1531 #endif /* COMPAT_43 */ 1532 1533 #ifndef _SYS_SYSPROTO_H_ 1534 struct sigaltstack_args { 1535 stack_t *ss; 1536 stack_t *oss; 1537 }; 1538 #endif 1539 /* ARGSUSED */ 1540 int 1541 sys_sigaltstack(td, uap) 1542 struct thread *td; 1543 register struct sigaltstack_args *uap; 1544 { 1545 stack_t ss, oss; 1546 int error; 1547 1548 if (uap->ss != NULL) { 1549 error = copyin(uap->ss, &ss, sizeof(ss)); 1550 if (error) 1551 return (error); 1552 } 1553 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1554 (uap->oss != NULL) ? &oss : NULL); 1555 if (error) 1556 return (error); 1557 if (uap->oss != NULL) 1558 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1559 return (error); 1560 } 1561 1562 int 1563 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1564 { 1565 struct proc *p = td->td_proc; 1566 int oonstack; 1567 1568 oonstack = sigonstack(cpu_getstack(td)); 1569 1570 if (oss != NULL) { 1571 *oss = td->td_sigstk; 1572 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1573 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1574 } 1575 1576 if (ss != NULL) { 1577 if (oonstack) 1578 return (EPERM); 1579 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1580 return (EINVAL); 1581 if (!(ss->ss_flags & SS_DISABLE)) { 1582 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1583 return (ENOMEM); 1584 1585 td->td_sigstk = *ss; 1586 td->td_pflags |= TDP_ALTSTACK; 1587 } else { 1588 td->td_pflags &= ~TDP_ALTSTACK; 1589 } 1590 } 1591 return (0); 1592 } 1593 1594 /* 1595 * Common code for kill process group/broadcast kill. 1596 * cp is calling process. 1597 */ 1598 static int 1599 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1600 { 1601 struct proc *p; 1602 struct pgrp *pgrp; 1603 int err; 1604 int ret; 1605 1606 ret = ESRCH; 1607 if (all) { 1608 /* 1609 * broadcast 1610 */ 1611 sx_slock(&allproc_lock); 1612 FOREACH_PROC_IN_SYSTEM(p) { 1613 PROC_LOCK(p); 1614 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1615 p == td->td_proc || p->p_state == PRS_NEW) { 1616 PROC_UNLOCK(p); 1617 continue; 1618 } 1619 err = p_cansignal(td, p, sig); 1620 if (err == 0) { 1621 if (sig) 1622 pksignal(p, sig, ksi); 1623 ret = err; 1624 } 1625 else if (ret == ESRCH) 1626 ret = err; 1627 PROC_UNLOCK(p); 1628 } 1629 sx_sunlock(&allproc_lock); 1630 } else { 1631 sx_slock(&proctree_lock); 1632 if (pgid == 0) { 1633 /* 1634 * zero pgid means send to my process group. 1635 */ 1636 pgrp = td->td_proc->p_pgrp; 1637 PGRP_LOCK(pgrp); 1638 } else { 1639 pgrp = pgfind(pgid); 1640 if (pgrp == NULL) { 1641 sx_sunlock(&proctree_lock); 1642 return (ESRCH); 1643 } 1644 } 1645 sx_sunlock(&proctree_lock); 1646 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1647 PROC_LOCK(p); 1648 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1649 p->p_state == PRS_NEW) { 1650 PROC_UNLOCK(p); 1651 continue; 1652 } 1653 err = p_cansignal(td, p, sig); 1654 if (err == 0) { 1655 if (sig) 1656 pksignal(p, sig, ksi); 1657 ret = err; 1658 } 1659 else if (ret == ESRCH) 1660 ret = err; 1661 PROC_UNLOCK(p); 1662 } 1663 PGRP_UNLOCK(pgrp); 1664 } 1665 return (ret); 1666 } 1667 1668 #ifndef _SYS_SYSPROTO_H_ 1669 struct kill_args { 1670 int pid; 1671 int signum; 1672 }; 1673 #endif 1674 /* ARGSUSED */ 1675 int 1676 sys_kill(struct thread *td, struct kill_args *uap) 1677 { 1678 ksiginfo_t ksi; 1679 struct proc *p; 1680 int error; 1681 1682 AUDIT_ARG_SIGNUM(uap->signum); 1683 AUDIT_ARG_PID(uap->pid); 1684 if ((u_int)uap->signum > _SIG_MAXSIG) 1685 return (EINVAL); 1686 1687 ksiginfo_init(&ksi); 1688 ksi.ksi_signo = uap->signum; 1689 ksi.ksi_code = SI_USER; 1690 ksi.ksi_pid = td->td_proc->p_pid; 1691 ksi.ksi_uid = td->td_ucred->cr_ruid; 1692 1693 if (uap->pid > 0) { 1694 /* kill single process */ 1695 if ((p = pfind(uap->pid)) == NULL) { 1696 if ((p = zpfind(uap->pid)) == NULL) 1697 return (ESRCH); 1698 } 1699 AUDIT_ARG_PROCESS(p); 1700 error = p_cansignal(td, p, uap->signum); 1701 if (error == 0 && uap->signum) 1702 pksignal(p, uap->signum, &ksi); 1703 PROC_UNLOCK(p); 1704 return (error); 1705 } 1706 switch (uap->pid) { 1707 case -1: /* broadcast signal */ 1708 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1709 case 0: /* signal own process group */ 1710 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1711 default: /* negative explicit process group */ 1712 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1713 } 1714 /* NOTREACHED */ 1715 } 1716 1717 int 1718 sys_pdkill(td, uap) 1719 struct thread *td; 1720 struct pdkill_args *uap; 1721 { 1722 #ifdef PROCDESC 1723 struct proc *p; 1724 int error; 1725 1726 AUDIT_ARG_SIGNUM(uap->signum); 1727 AUDIT_ARG_FD(uap->fd); 1728 if ((u_int)uap->signum > _SIG_MAXSIG) 1729 return (EINVAL); 1730 1731 error = procdesc_find(td, uap->fd, CAP_PDKILL, &p); 1732 if (error) 1733 return (error); 1734 AUDIT_ARG_PROCESS(p); 1735 error = p_cansignal(td, p, uap->signum); 1736 if (error == 0 && uap->signum) 1737 kern_psignal(p, uap->signum); 1738 PROC_UNLOCK(p); 1739 return (error); 1740 #else 1741 return (ENOSYS); 1742 #endif 1743 } 1744 1745 #if defined(COMPAT_43) 1746 #ifndef _SYS_SYSPROTO_H_ 1747 struct okillpg_args { 1748 int pgid; 1749 int signum; 1750 }; 1751 #endif 1752 /* ARGSUSED */ 1753 int 1754 okillpg(struct thread *td, struct okillpg_args *uap) 1755 { 1756 ksiginfo_t ksi; 1757 1758 AUDIT_ARG_SIGNUM(uap->signum); 1759 AUDIT_ARG_PID(uap->pgid); 1760 if ((u_int)uap->signum > _SIG_MAXSIG) 1761 return (EINVAL); 1762 1763 ksiginfo_init(&ksi); 1764 ksi.ksi_signo = uap->signum; 1765 ksi.ksi_code = SI_USER; 1766 ksi.ksi_pid = td->td_proc->p_pid; 1767 ksi.ksi_uid = td->td_ucred->cr_ruid; 1768 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1769 } 1770 #endif /* COMPAT_43 */ 1771 1772 #ifndef _SYS_SYSPROTO_H_ 1773 struct sigqueue_args { 1774 pid_t pid; 1775 int signum; 1776 /* union sigval */ void *value; 1777 }; 1778 #endif 1779 int 1780 sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1781 { 1782 ksiginfo_t ksi; 1783 struct proc *p; 1784 int error; 1785 1786 if ((u_int)uap->signum > _SIG_MAXSIG) 1787 return (EINVAL); 1788 1789 /* 1790 * Specification says sigqueue can only send signal to 1791 * single process. 1792 */ 1793 if (uap->pid <= 0) 1794 return (EINVAL); 1795 1796 if ((p = pfind(uap->pid)) == NULL) { 1797 if ((p = zpfind(uap->pid)) == NULL) 1798 return (ESRCH); 1799 } 1800 error = p_cansignal(td, p, uap->signum); 1801 if (error == 0 && uap->signum != 0) { 1802 ksiginfo_init(&ksi); 1803 ksi.ksi_flags = KSI_SIGQ; 1804 ksi.ksi_signo = uap->signum; 1805 ksi.ksi_code = SI_QUEUE; 1806 ksi.ksi_pid = td->td_proc->p_pid; 1807 ksi.ksi_uid = td->td_ucred->cr_ruid; 1808 ksi.ksi_value.sival_ptr = uap->value; 1809 error = pksignal(p, ksi.ksi_signo, &ksi); 1810 } 1811 PROC_UNLOCK(p); 1812 return (error); 1813 } 1814 1815 /* 1816 * Send a signal to a process group. 1817 */ 1818 void 1819 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1820 { 1821 struct pgrp *pgrp; 1822 1823 if (pgid != 0) { 1824 sx_slock(&proctree_lock); 1825 pgrp = pgfind(pgid); 1826 sx_sunlock(&proctree_lock); 1827 if (pgrp != NULL) { 1828 pgsignal(pgrp, sig, 0, ksi); 1829 PGRP_UNLOCK(pgrp); 1830 } 1831 } 1832 } 1833 1834 /* 1835 * Send a signal to a process group. If checktty is 1, 1836 * limit to members which have a controlling terminal. 1837 */ 1838 void 1839 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1840 { 1841 struct proc *p; 1842 1843 if (pgrp) { 1844 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1845 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1846 PROC_LOCK(p); 1847 if (p->p_state == PRS_NORMAL && 1848 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1849 pksignal(p, sig, ksi); 1850 PROC_UNLOCK(p); 1851 } 1852 } 1853 } 1854 1855 /* 1856 * Send a signal caused by a trap to the current thread. If it will be 1857 * caught immediately, deliver it with correct code. Otherwise, post it 1858 * normally. 1859 */ 1860 void 1861 trapsignal(struct thread *td, ksiginfo_t *ksi) 1862 { 1863 struct sigacts *ps; 1864 sigset_t mask; 1865 struct proc *p; 1866 int sig; 1867 int code; 1868 1869 p = td->td_proc; 1870 sig = ksi->ksi_signo; 1871 code = ksi->ksi_code; 1872 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1873 1874 PROC_LOCK(p); 1875 ps = p->p_sigacts; 1876 mtx_lock(&ps->ps_mtx); 1877 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1878 !SIGISMEMBER(td->td_sigmask, sig)) { 1879 td->td_ru.ru_nsignals++; 1880 #ifdef KTRACE 1881 if (KTRPOINT(curthread, KTR_PSIG)) 1882 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1883 &td->td_sigmask, code); 1884 #endif 1885 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1886 ksi, &td->td_sigmask); 1887 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1888 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1889 SIGADDSET(mask, sig); 1890 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1891 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1892 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1893 /* 1894 * See kern_sigaction() for origin of this code. 1895 */ 1896 SIGDELSET(ps->ps_sigcatch, sig); 1897 if (sig != SIGCONT && 1898 sigprop(sig) & SA_IGNORE) 1899 SIGADDSET(ps->ps_sigignore, sig); 1900 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1901 } 1902 mtx_unlock(&ps->ps_mtx); 1903 } else { 1904 /* 1905 * Avoid a possible infinite loop if the thread 1906 * masking the signal or process is ignoring the 1907 * signal. 1908 */ 1909 if (kern_forcesigexit && 1910 (SIGISMEMBER(td->td_sigmask, sig) || 1911 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1912 SIGDELSET(td->td_sigmask, sig); 1913 SIGDELSET(ps->ps_sigcatch, sig); 1914 SIGDELSET(ps->ps_sigignore, sig); 1915 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1916 } 1917 mtx_unlock(&ps->ps_mtx); 1918 p->p_code = code; /* XXX for core dump/debugger */ 1919 p->p_sig = sig; /* XXX to verify code */ 1920 tdsendsignal(p, td, sig, ksi); 1921 } 1922 PROC_UNLOCK(p); 1923 } 1924 1925 static struct thread * 1926 sigtd(struct proc *p, int sig, int prop) 1927 { 1928 struct thread *td, *signal_td; 1929 1930 PROC_LOCK_ASSERT(p, MA_OWNED); 1931 1932 /* 1933 * Check if current thread can handle the signal without 1934 * switching context to another thread. 1935 */ 1936 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1937 return (curthread); 1938 signal_td = NULL; 1939 FOREACH_THREAD_IN_PROC(p, td) { 1940 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1941 signal_td = td; 1942 break; 1943 } 1944 } 1945 if (signal_td == NULL) 1946 signal_td = FIRST_THREAD_IN_PROC(p); 1947 return (signal_td); 1948 } 1949 1950 /* 1951 * Send the signal to the process. If the signal has an action, the action 1952 * is usually performed by the target process rather than the caller; we add 1953 * the signal to the set of pending signals for the process. 1954 * 1955 * Exceptions: 1956 * o When a stop signal is sent to a sleeping process that takes the 1957 * default action, the process is stopped without awakening it. 1958 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1959 * regardless of the signal action (eg, blocked or ignored). 1960 * 1961 * Other ignored signals are discarded immediately. 1962 * 1963 * NB: This function may be entered from the debugger via the "kill" DDB 1964 * command. There is little that can be done to mitigate the possibly messy 1965 * side effects of this unwise possibility. 1966 */ 1967 void 1968 kern_psignal(struct proc *p, int sig) 1969 { 1970 ksiginfo_t ksi; 1971 1972 ksiginfo_init(&ksi); 1973 ksi.ksi_signo = sig; 1974 ksi.ksi_code = SI_KERNEL; 1975 (void) tdsendsignal(p, NULL, sig, &ksi); 1976 } 1977 1978 int 1979 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1980 { 1981 1982 return (tdsendsignal(p, NULL, sig, ksi)); 1983 } 1984 1985 /* Utility function for finding a thread to send signal event to. */ 1986 int 1987 sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 1988 { 1989 struct thread *td; 1990 1991 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1992 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 1993 if (td == NULL) 1994 return (ESRCH); 1995 *ttd = td; 1996 } else { 1997 *ttd = NULL; 1998 PROC_LOCK(p); 1999 } 2000 return (0); 2001 } 2002 2003 void 2004 tdsignal(struct thread *td, int sig) 2005 { 2006 ksiginfo_t ksi; 2007 2008 ksiginfo_init(&ksi); 2009 ksi.ksi_signo = sig; 2010 ksi.ksi_code = SI_KERNEL; 2011 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2012 } 2013 2014 void 2015 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2016 { 2017 2018 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2019 } 2020 2021 int 2022 tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2023 { 2024 sig_t action; 2025 sigqueue_t *sigqueue; 2026 int prop; 2027 struct sigacts *ps; 2028 int intrval; 2029 int ret = 0; 2030 int wakeup_swapper; 2031 2032 MPASS(td == NULL || p == td->td_proc); 2033 PROC_LOCK_ASSERT(p, MA_OWNED); 2034 2035 if (!_SIG_VALID(sig)) 2036 panic("%s(): invalid signal %d", __func__, sig); 2037 2038 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2039 2040 /* 2041 * IEEE Std 1003.1-2001: return success when killing a zombie. 2042 */ 2043 if (p->p_state == PRS_ZOMBIE) { 2044 if (ksi && (ksi->ksi_flags & KSI_INS)) 2045 ksiginfo_tryfree(ksi); 2046 return (ret); 2047 } 2048 2049 ps = p->p_sigacts; 2050 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2051 prop = sigprop(sig); 2052 2053 if (td == NULL) { 2054 td = sigtd(p, sig, prop); 2055 sigqueue = &p->p_sigqueue; 2056 } else { 2057 KASSERT(td->td_proc == p, ("invalid thread")); 2058 sigqueue = &td->td_sigqueue; 2059 } 2060 2061 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2062 2063 /* 2064 * If the signal is being ignored, 2065 * then we forget about it immediately. 2066 * (Note: we don't set SIGCONT in ps_sigignore, 2067 * and if it is set to SIG_IGN, 2068 * action will be SIG_DFL here.) 2069 */ 2070 mtx_lock(&ps->ps_mtx); 2071 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2072 SDT_PROBE(proc, kernel, , signal_discard, td, p, sig, 0, 0 ); 2073 2074 mtx_unlock(&ps->ps_mtx); 2075 if (ksi && (ksi->ksi_flags & KSI_INS)) 2076 ksiginfo_tryfree(ksi); 2077 return (ret); 2078 } 2079 if (SIGISMEMBER(td->td_sigmask, sig)) 2080 action = SIG_HOLD; 2081 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2082 action = SIG_CATCH; 2083 else 2084 action = SIG_DFL; 2085 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2086 intrval = EINTR; 2087 else 2088 intrval = ERESTART; 2089 mtx_unlock(&ps->ps_mtx); 2090 2091 if (prop & SA_CONT) 2092 sigqueue_delete_stopmask_proc(p); 2093 else if (prop & SA_STOP) { 2094 /* 2095 * If sending a tty stop signal to a member of an orphaned 2096 * process group, discard the signal here if the action 2097 * is default; don't stop the process below if sleeping, 2098 * and don't clear any pending SIGCONT. 2099 */ 2100 if ((prop & SA_TTYSTOP) && 2101 (p->p_pgrp->pg_jobc == 0) && 2102 (action == SIG_DFL)) { 2103 if (ksi && (ksi->ksi_flags & KSI_INS)) 2104 ksiginfo_tryfree(ksi); 2105 return (ret); 2106 } 2107 sigqueue_delete_proc(p, SIGCONT); 2108 if (p->p_flag & P_CONTINUED) { 2109 p->p_flag &= ~P_CONTINUED; 2110 PROC_LOCK(p->p_pptr); 2111 sigqueue_take(p->p_ksi); 2112 PROC_UNLOCK(p->p_pptr); 2113 } 2114 } 2115 2116 ret = sigqueue_add(sigqueue, sig, ksi); 2117 if (ret != 0) 2118 return (ret); 2119 signotify(td); 2120 /* 2121 * Defer further processing for signals which are held, 2122 * except that stopped processes must be continued by SIGCONT. 2123 */ 2124 if (action == SIG_HOLD && 2125 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2126 return (ret); 2127 /* 2128 * SIGKILL: Remove procfs STOPEVENTs. 2129 */ 2130 if (sig == SIGKILL) { 2131 /* from procfs_ioctl.c: PIOCBIC */ 2132 p->p_stops = 0; 2133 /* from procfs_ioctl.c: PIOCCONT */ 2134 p->p_step = 0; 2135 wakeup(&p->p_step); 2136 } 2137 /* 2138 * Some signals have a process-wide effect and a per-thread 2139 * component. Most processing occurs when the process next 2140 * tries to cross the user boundary, however there are some 2141 * times when processing needs to be done immediatly, such as 2142 * waking up threads so that they can cross the user boundary. 2143 * We try do the per-process part here. 2144 */ 2145 if (P_SHOULDSTOP(p)) { 2146 KASSERT(!(p->p_flag & P_WEXIT), 2147 ("signal to stopped but exiting process")); 2148 if (sig == SIGKILL) { 2149 /* 2150 * If traced process is already stopped, 2151 * then no further action is necessary. 2152 */ 2153 if (p->p_flag & P_TRACED) 2154 goto out; 2155 /* 2156 * SIGKILL sets process running. 2157 * It will die elsewhere. 2158 * All threads must be restarted. 2159 */ 2160 p->p_flag &= ~P_STOPPED_SIG; 2161 goto runfast; 2162 } 2163 2164 if (prop & SA_CONT) { 2165 /* 2166 * If traced process is already stopped, 2167 * then no further action is necessary. 2168 */ 2169 if (p->p_flag & P_TRACED) 2170 goto out; 2171 /* 2172 * If SIGCONT is default (or ignored), we continue the 2173 * process but don't leave the signal in sigqueue as 2174 * it has no further action. If SIGCONT is held, we 2175 * continue the process and leave the signal in 2176 * sigqueue. If the process catches SIGCONT, let it 2177 * handle the signal itself. If it isn't waiting on 2178 * an event, it goes back to run state. 2179 * Otherwise, process goes back to sleep state. 2180 */ 2181 p->p_flag &= ~P_STOPPED_SIG; 2182 PROC_SLOCK(p); 2183 if (p->p_numthreads == p->p_suspcount) { 2184 PROC_SUNLOCK(p); 2185 p->p_flag |= P_CONTINUED; 2186 p->p_xstat = SIGCONT; 2187 PROC_LOCK(p->p_pptr); 2188 childproc_continued(p); 2189 PROC_UNLOCK(p->p_pptr); 2190 PROC_SLOCK(p); 2191 } 2192 if (action == SIG_DFL) { 2193 thread_unsuspend(p); 2194 PROC_SUNLOCK(p); 2195 sigqueue_delete(sigqueue, sig); 2196 goto out; 2197 } 2198 if (action == SIG_CATCH) { 2199 /* 2200 * The process wants to catch it so it needs 2201 * to run at least one thread, but which one? 2202 */ 2203 PROC_SUNLOCK(p); 2204 goto runfast; 2205 } 2206 /* 2207 * The signal is not ignored or caught. 2208 */ 2209 thread_unsuspend(p); 2210 PROC_SUNLOCK(p); 2211 goto out; 2212 } 2213 2214 if (prop & SA_STOP) { 2215 /* 2216 * If traced process is already stopped, 2217 * then no further action is necessary. 2218 */ 2219 if (p->p_flag & P_TRACED) 2220 goto out; 2221 /* 2222 * Already stopped, don't need to stop again 2223 * (If we did the shell could get confused). 2224 * Just make sure the signal STOP bit set. 2225 */ 2226 p->p_flag |= P_STOPPED_SIG; 2227 sigqueue_delete(sigqueue, sig); 2228 goto out; 2229 } 2230 2231 /* 2232 * All other kinds of signals: 2233 * If a thread is sleeping interruptibly, simulate a 2234 * wakeup so that when it is continued it will be made 2235 * runnable and can look at the signal. However, don't make 2236 * the PROCESS runnable, leave it stopped. 2237 * It may run a bit until it hits a thread_suspend_check(). 2238 */ 2239 wakeup_swapper = 0; 2240 PROC_SLOCK(p); 2241 thread_lock(td); 2242 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2243 wakeup_swapper = sleepq_abort(td, intrval); 2244 thread_unlock(td); 2245 PROC_SUNLOCK(p); 2246 if (wakeup_swapper) 2247 kick_proc0(); 2248 goto out; 2249 /* 2250 * Mutexes are short lived. Threads waiting on them will 2251 * hit thread_suspend_check() soon. 2252 */ 2253 } else if (p->p_state == PRS_NORMAL) { 2254 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2255 tdsigwakeup(td, sig, action, intrval); 2256 goto out; 2257 } 2258 2259 MPASS(action == SIG_DFL); 2260 2261 if (prop & SA_STOP) { 2262 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2263 goto out; 2264 p->p_flag |= P_STOPPED_SIG; 2265 p->p_xstat = sig; 2266 PROC_SLOCK(p); 2267 sig_suspend_threads(td, p, 1); 2268 if (p->p_numthreads == p->p_suspcount) { 2269 /* 2270 * only thread sending signal to another 2271 * process can reach here, if thread is sending 2272 * signal to its process, because thread does 2273 * not suspend itself here, p_numthreads 2274 * should never be equal to p_suspcount. 2275 */ 2276 thread_stopped(p); 2277 PROC_SUNLOCK(p); 2278 sigqueue_delete_proc(p, p->p_xstat); 2279 } else 2280 PROC_SUNLOCK(p); 2281 goto out; 2282 } 2283 } else { 2284 /* Not in "NORMAL" state. discard the signal. */ 2285 sigqueue_delete(sigqueue, sig); 2286 goto out; 2287 } 2288 2289 /* 2290 * The process is not stopped so we need to apply the signal to all the 2291 * running threads. 2292 */ 2293 runfast: 2294 tdsigwakeup(td, sig, action, intrval); 2295 PROC_SLOCK(p); 2296 thread_unsuspend(p); 2297 PROC_SUNLOCK(p); 2298 out: 2299 /* If we jump here, proc slock should not be owned. */ 2300 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2301 return (ret); 2302 } 2303 2304 /* 2305 * The force of a signal has been directed against a single 2306 * thread. We need to see what we can do about knocking it 2307 * out of any sleep it may be in etc. 2308 */ 2309 static void 2310 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2311 { 2312 struct proc *p = td->td_proc; 2313 register int prop; 2314 int wakeup_swapper; 2315 2316 wakeup_swapper = 0; 2317 PROC_LOCK_ASSERT(p, MA_OWNED); 2318 prop = sigprop(sig); 2319 2320 PROC_SLOCK(p); 2321 thread_lock(td); 2322 /* 2323 * Bring the priority of a thread up if we want it to get 2324 * killed in this lifetime. 2325 */ 2326 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2327 sched_prio(td, PUSER); 2328 if (TD_ON_SLEEPQ(td)) { 2329 /* 2330 * If thread is sleeping uninterruptibly 2331 * we can't interrupt the sleep... the signal will 2332 * be noticed when the process returns through 2333 * trap() or syscall(). 2334 */ 2335 if ((td->td_flags & TDF_SINTR) == 0) 2336 goto out; 2337 /* 2338 * If SIGCONT is default (or ignored) and process is 2339 * asleep, we are finished; the process should not 2340 * be awakened. 2341 */ 2342 if ((prop & SA_CONT) && action == SIG_DFL) { 2343 thread_unlock(td); 2344 PROC_SUNLOCK(p); 2345 sigqueue_delete(&p->p_sigqueue, sig); 2346 /* 2347 * It may be on either list in this state. 2348 * Remove from both for now. 2349 */ 2350 sigqueue_delete(&td->td_sigqueue, sig); 2351 return; 2352 } 2353 2354 /* 2355 * Don't awaken a sleeping thread for SIGSTOP if the 2356 * STOP signal is deferred. 2357 */ 2358 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2359 goto out; 2360 2361 /* 2362 * Give low priority threads a better chance to run. 2363 */ 2364 if (td->td_priority > PUSER) 2365 sched_prio(td, PUSER); 2366 2367 wakeup_swapper = sleepq_abort(td, intrval); 2368 } else { 2369 /* 2370 * Other states do nothing with the signal immediately, 2371 * other than kicking ourselves if we are running. 2372 * It will either never be noticed, or noticed very soon. 2373 */ 2374 #ifdef SMP 2375 if (TD_IS_RUNNING(td) && td != curthread) 2376 forward_signal(td); 2377 #endif 2378 } 2379 out: 2380 PROC_SUNLOCK(p); 2381 thread_unlock(td); 2382 if (wakeup_swapper) 2383 kick_proc0(); 2384 } 2385 2386 static void 2387 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2388 { 2389 struct thread *td2; 2390 int wakeup_swapper; 2391 2392 PROC_LOCK_ASSERT(p, MA_OWNED); 2393 PROC_SLOCK_ASSERT(p, MA_OWNED); 2394 2395 wakeup_swapper = 0; 2396 FOREACH_THREAD_IN_PROC(p, td2) { 2397 thread_lock(td2); 2398 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2399 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2400 (td2->td_flags & TDF_SINTR)) { 2401 if (td2->td_flags & TDF_SBDRY) { 2402 /* 2403 * Once a thread is asleep with 2404 * TDF_SBDRY set, it should never 2405 * become suspended due to this check. 2406 */ 2407 KASSERT(!TD_IS_SUSPENDED(td2), 2408 ("thread with deferred stops suspended")); 2409 } else if (!TD_IS_SUSPENDED(td2)) { 2410 thread_suspend_one(td2); 2411 } 2412 } else if (!TD_IS_SUSPENDED(td2)) { 2413 if (sending || td != td2) 2414 td2->td_flags |= TDF_ASTPENDING; 2415 #ifdef SMP 2416 if (TD_IS_RUNNING(td2) && td2 != td) 2417 forward_signal(td2); 2418 #endif 2419 } 2420 thread_unlock(td2); 2421 } 2422 if (wakeup_swapper) 2423 kick_proc0(); 2424 } 2425 2426 int 2427 ptracestop(struct thread *td, int sig) 2428 { 2429 struct proc *p = td->td_proc; 2430 2431 PROC_LOCK_ASSERT(p, MA_OWNED); 2432 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2433 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2434 &p->p_mtx.lock_object, "Stopping for traced signal"); 2435 2436 td->td_dbgflags |= TDB_XSIG; 2437 td->td_xsig = sig; 2438 PROC_SLOCK(p); 2439 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2440 if (p->p_flag & P_SINGLE_EXIT) { 2441 td->td_dbgflags &= ~TDB_XSIG; 2442 PROC_SUNLOCK(p); 2443 return (sig); 2444 } 2445 /* 2446 * Just make wait() to work, the last stopped thread 2447 * will win. 2448 */ 2449 p->p_xstat = sig; 2450 p->p_xthread = td; 2451 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2452 sig_suspend_threads(td, p, 0); 2453 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2454 td->td_dbgflags &= ~TDB_STOPATFORK; 2455 cv_broadcast(&p->p_dbgwait); 2456 } 2457 stopme: 2458 thread_suspend_switch(td); 2459 if (!(p->p_flag & P_TRACED)) { 2460 break; 2461 } 2462 if (td->td_dbgflags & TDB_SUSPEND) { 2463 if (p->p_flag & P_SINGLE_EXIT) 2464 break; 2465 goto stopme; 2466 } 2467 } 2468 PROC_SUNLOCK(p); 2469 return (td->td_xsig); 2470 } 2471 2472 static void 2473 reschedule_signals(struct proc *p, sigset_t block, int flags) 2474 { 2475 struct sigacts *ps; 2476 struct thread *td; 2477 int sig; 2478 2479 PROC_LOCK_ASSERT(p, MA_OWNED); 2480 if (SIGISEMPTY(p->p_siglist)) 2481 return; 2482 ps = p->p_sigacts; 2483 SIGSETAND(block, p->p_siglist); 2484 while ((sig = sig_ffs(&block)) != 0) { 2485 SIGDELSET(block, sig); 2486 td = sigtd(p, sig, 0); 2487 signotify(td); 2488 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2489 mtx_lock(&ps->ps_mtx); 2490 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2491 tdsigwakeup(td, sig, SIG_CATCH, 2492 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2493 ERESTART)); 2494 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2495 mtx_unlock(&ps->ps_mtx); 2496 } 2497 } 2498 2499 void 2500 tdsigcleanup(struct thread *td) 2501 { 2502 struct proc *p; 2503 sigset_t unblocked; 2504 2505 p = td->td_proc; 2506 PROC_LOCK_ASSERT(p, MA_OWNED); 2507 2508 sigqueue_flush(&td->td_sigqueue); 2509 if (p->p_numthreads == 1) 2510 return; 2511 2512 /* 2513 * Since we cannot handle signals, notify signal post code 2514 * about this by filling the sigmask. 2515 * 2516 * Also, if needed, wake up thread(s) that do not block the 2517 * same signals as the exiting thread, since the thread might 2518 * have been selected for delivery and woken up. 2519 */ 2520 SIGFILLSET(unblocked); 2521 SIGSETNAND(unblocked, td->td_sigmask); 2522 SIGFILLSET(td->td_sigmask); 2523 reschedule_signals(p, unblocked, 0); 2524 2525 } 2526 2527 /* 2528 * Defer the delivery of SIGSTOP for the current thread. Returns true 2529 * if stops were deferred and false if they were already deferred. 2530 */ 2531 int 2532 sigdeferstop(void) 2533 { 2534 struct thread *td; 2535 2536 td = curthread; 2537 if (td->td_flags & TDF_SBDRY) 2538 return (0); 2539 thread_lock(td); 2540 td->td_flags |= TDF_SBDRY; 2541 thread_unlock(td); 2542 return (1); 2543 } 2544 2545 /* 2546 * Permit the delivery of SIGSTOP for the current thread. This does 2547 * not immediately suspend if a stop was posted. Instead, the thread 2548 * will suspend either via ast() or a subsequent interruptible sleep. 2549 */ 2550 void 2551 sigallowstop() 2552 { 2553 struct thread *td; 2554 2555 td = curthread; 2556 thread_lock(td); 2557 td->td_flags &= ~TDF_SBDRY; 2558 thread_unlock(td); 2559 } 2560 2561 /* 2562 * If the current process has received a signal (should be caught or cause 2563 * termination, should interrupt current syscall), return the signal number. 2564 * Stop signals with default action are processed immediately, then cleared; 2565 * they aren't returned. This is checked after each entry to the system for 2566 * a syscall or trap (though this can usually be done without calling issignal 2567 * by checking the pending signal masks in cursig.) The normal call 2568 * sequence is 2569 * 2570 * while (sig = cursig(curthread)) 2571 * postsig(sig); 2572 */ 2573 static int 2574 issignal(struct thread *td, int stop_allowed) 2575 { 2576 struct proc *p; 2577 struct sigacts *ps; 2578 struct sigqueue *queue; 2579 sigset_t sigpending; 2580 int sig, prop, newsig; 2581 2582 p = td->td_proc; 2583 ps = p->p_sigacts; 2584 mtx_assert(&ps->ps_mtx, MA_OWNED); 2585 PROC_LOCK_ASSERT(p, MA_OWNED); 2586 for (;;) { 2587 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2588 2589 sigpending = td->td_sigqueue.sq_signals; 2590 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2591 SIGSETNAND(sigpending, td->td_sigmask); 2592 2593 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2594 SIG_STOPSIGMASK(sigpending); 2595 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2596 return (0); 2597 sig = sig_ffs(&sigpending); 2598 2599 if (p->p_stops & S_SIG) { 2600 mtx_unlock(&ps->ps_mtx); 2601 stopevent(p, S_SIG, sig); 2602 mtx_lock(&ps->ps_mtx); 2603 } 2604 2605 /* 2606 * We should see pending but ignored signals 2607 * only if P_TRACED was on when they were posted. 2608 */ 2609 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2610 sigqueue_delete(&td->td_sigqueue, sig); 2611 sigqueue_delete(&p->p_sigqueue, sig); 2612 continue; 2613 } 2614 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2615 /* 2616 * If traced, always stop. 2617 * Remove old signal from queue before the stop. 2618 * XXX shrug off debugger, it causes siginfo to 2619 * be thrown away. 2620 */ 2621 queue = &td->td_sigqueue; 2622 td->td_dbgksi.ksi_signo = 0; 2623 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2624 queue = &p->p_sigqueue; 2625 sigqueue_get(queue, sig, &td->td_dbgksi); 2626 } 2627 2628 mtx_unlock(&ps->ps_mtx); 2629 newsig = ptracestop(td, sig); 2630 mtx_lock(&ps->ps_mtx); 2631 2632 if (sig != newsig) { 2633 2634 /* 2635 * If parent wants us to take the signal, 2636 * then it will leave it in p->p_xstat; 2637 * otherwise we just look for signals again. 2638 */ 2639 if (newsig == 0) 2640 continue; 2641 sig = newsig; 2642 2643 /* 2644 * Put the new signal into td_sigqueue. If the 2645 * signal is being masked, look for other signals. 2646 */ 2647 sigqueue_add(queue, sig, NULL); 2648 if (SIGISMEMBER(td->td_sigmask, sig)) 2649 continue; 2650 signotify(td); 2651 } else { 2652 if (td->td_dbgksi.ksi_signo != 0) { 2653 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2654 if (sigqueue_add(&td->td_sigqueue, sig, 2655 &td->td_dbgksi) != 0) 2656 td->td_dbgksi.ksi_signo = 0; 2657 } 2658 if (td->td_dbgksi.ksi_signo == 0) 2659 sigqueue_add(&td->td_sigqueue, sig, 2660 NULL); 2661 } 2662 2663 /* 2664 * If the traced bit got turned off, go back up 2665 * to the top to rescan signals. This ensures 2666 * that p_sig* and p_sigact are consistent. 2667 */ 2668 if ((p->p_flag & P_TRACED) == 0) 2669 continue; 2670 } 2671 2672 prop = sigprop(sig); 2673 2674 /* 2675 * Decide whether the signal should be returned. 2676 * Return the signal's number, or fall through 2677 * to clear it from the pending mask. 2678 */ 2679 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2680 2681 case (intptr_t)SIG_DFL: 2682 /* 2683 * Don't take default actions on system processes. 2684 */ 2685 if (p->p_pid <= 1) { 2686 #ifdef DIAGNOSTIC 2687 /* 2688 * Are you sure you want to ignore SIGSEGV 2689 * in init? XXX 2690 */ 2691 printf("Process (pid %lu) got signal %d\n", 2692 (u_long)p->p_pid, sig); 2693 #endif 2694 break; /* == ignore */ 2695 } 2696 /* 2697 * If there is a pending stop signal to process 2698 * with default action, stop here, 2699 * then clear the signal. However, 2700 * if process is member of an orphaned 2701 * process group, ignore tty stop signals. 2702 */ 2703 if (prop & SA_STOP) { 2704 if (p->p_flag & (P_TRACED|P_WEXIT) || 2705 (p->p_pgrp->pg_jobc == 0 && 2706 prop & SA_TTYSTOP)) 2707 break; /* == ignore */ 2708 mtx_unlock(&ps->ps_mtx); 2709 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2710 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2711 p->p_flag |= P_STOPPED_SIG; 2712 p->p_xstat = sig; 2713 PROC_SLOCK(p); 2714 sig_suspend_threads(td, p, 0); 2715 thread_suspend_switch(td); 2716 PROC_SUNLOCK(p); 2717 mtx_lock(&ps->ps_mtx); 2718 break; 2719 } else if (prop & SA_IGNORE) { 2720 /* 2721 * Except for SIGCONT, shouldn't get here. 2722 * Default action is to ignore; drop it. 2723 */ 2724 break; /* == ignore */ 2725 } else 2726 return (sig); 2727 /*NOTREACHED*/ 2728 2729 case (intptr_t)SIG_IGN: 2730 /* 2731 * Masking above should prevent us ever trying 2732 * to take action on an ignored signal other 2733 * than SIGCONT, unless process is traced. 2734 */ 2735 if ((prop & SA_CONT) == 0 && 2736 (p->p_flag & P_TRACED) == 0) 2737 printf("issignal\n"); 2738 break; /* == ignore */ 2739 2740 default: 2741 /* 2742 * This signal has an action, let 2743 * postsig() process it. 2744 */ 2745 return (sig); 2746 } 2747 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2748 sigqueue_delete(&p->p_sigqueue, sig); 2749 } 2750 /* NOTREACHED */ 2751 } 2752 2753 void 2754 thread_stopped(struct proc *p) 2755 { 2756 int n; 2757 2758 PROC_LOCK_ASSERT(p, MA_OWNED); 2759 PROC_SLOCK_ASSERT(p, MA_OWNED); 2760 n = p->p_suspcount; 2761 if (p == curproc) 2762 n++; 2763 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2764 PROC_SUNLOCK(p); 2765 p->p_flag &= ~P_WAITED; 2766 PROC_LOCK(p->p_pptr); 2767 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2768 CLD_TRAPPED : CLD_STOPPED); 2769 PROC_UNLOCK(p->p_pptr); 2770 PROC_SLOCK(p); 2771 } 2772 } 2773 2774 /* 2775 * Take the action for the specified signal 2776 * from the current set of pending signals. 2777 */ 2778 int 2779 postsig(sig) 2780 register int sig; 2781 { 2782 struct thread *td = curthread; 2783 register struct proc *p = td->td_proc; 2784 struct sigacts *ps; 2785 sig_t action; 2786 ksiginfo_t ksi; 2787 sigset_t returnmask, mask; 2788 2789 KASSERT(sig != 0, ("postsig")); 2790 2791 PROC_LOCK_ASSERT(p, MA_OWNED); 2792 ps = p->p_sigacts; 2793 mtx_assert(&ps->ps_mtx, MA_OWNED); 2794 ksiginfo_init(&ksi); 2795 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2796 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2797 return (0); 2798 ksi.ksi_signo = sig; 2799 if (ksi.ksi_code == SI_TIMER) 2800 itimer_accept(p, ksi.ksi_timerid, &ksi); 2801 action = ps->ps_sigact[_SIG_IDX(sig)]; 2802 #ifdef KTRACE 2803 if (KTRPOINT(td, KTR_PSIG)) 2804 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2805 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2806 #endif 2807 if (p->p_stops & S_SIG) { 2808 mtx_unlock(&ps->ps_mtx); 2809 stopevent(p, S_SIG, sig); 2810 mtx_lock(&ps->ps_mtx); 2811 } 2812 2813 if (action == SIG_DFL) { 2814 /* 2815 * Default action, where the default is to kill 2816 * the process. (Other cases were ignored above.) 2817 */ 2818 mtx_unlock(&ps->ps_mtx); 2819 sigexit(td, sig); 2820 /* NOTREACHED */ 2821 } else { 2822 /* 2823 * If we get here, the signal must be caught. 2824 */ 2825 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2826 ("postsig action")); 2827 /* 2828 * Set the new mask value and also defer further 2829 * occurrences of this signal. 2830 * 2831 * Special case: user has done a sigsuspend. Here the 2832 * current mask is not of interest, but rather the 2833 * mask from before the sigsuspend is what we want 2834 * restored after the signal processing is completed. 2835 */ 2836 if (td->td_pflags & TDP_OLDMASK) { 2837 returnmask = td->td_oldsigmask; 2838 td->td_pflags &= ~TDP_OLDMASK; 2839 } else 2840 returnmask = td->td_sigmask; 2841 2842 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2843 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2844 SIGADDSET(mask, sig); 2845 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2846 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2847 2848 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2849 /* 2850 * See kern_sigaction() for origin of this code. 2851 */ 2852 SIGDELSET(ps->ps_sigcatch, sig); 2853 if (sig != SIGCONT && 2854 sigprop(sig) & SA_IGNORE) 2855 SIGADDSET(ps->ps_sigignore, sig); 2856 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2857 } 2858 td->td_ru.ru_nsignals++; 2859 if (p->p_sig == sig) { 2860 p->p_code = 0; 2861 p->p_sig = 0; 2862 } 2863 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2864 } 2865 return (1); 2866 } 2867 2868 /* 2869 * Kill the current process for stated reason. 2870 */ 2871 void 2872 killproc(p, why) 2873 struct proc *p; 2874 char *why; 2875 { 2876 2877 PROC_LOCK_ASSERT(p, MA_OWNED); 2878 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2879 p, p->p_pid, p->p_comm); 2880 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2881 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2882 p->p_flag |= P_WKILLED; 2883 kern_psignal(p, SIGKILL); 2884 } 2885 2886 /* 2887 * Force the current process to exit with the specified signal, dumping core 2888 * if appropriate. We bypass the normal tests for masked and caught signals, 2889 * allowing unrecoverable failures to terminate the process without changing 2890 * signal state. Mark the accounting record with the signal termination. 2891 * If dumping core, save the signal number for the debugger. Calls exit and 2892 * does not return. 2893 */ 2894 void 2895 sigexit(td, sig) 2896 struct thread *td; 2897 int sig; 2898 { 2899 struct proc *p = td->td_proc; 2900 2901 PROC_LOCK_ASSERT(p, MA_OWNED); 2902 p->p_acflag |= AXSIG; 2903 /* 2904 * We must be single-threading to generate a core dump. This 2905 * ensures that the registers in the core file are up-to-date. 2906 * Also, the ELF dump handler assumes that the thread list doesn't 2907 * change out from under it. 2908 * 2909 * XXX If another thread attempts to single-thread before us 2910 * (e.g. via fork()), we won't get a dump at all. 2911 */ 2912 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2913 p->p_sig = sig; 2914 /* 2915 * Log signals which would cause core dumps 2916 * (Log as LOG_INFO to appease those who don't want 2917 * these messages.) 2918 * XXX : Todo, as well as euid, write out ruid too 2919 * Note that coredump() drops proc lock. 2920 */ 2921 if (coredump(td) == 0) 2922 sig |= WCOREFLAG; 2923 if (kern_logsigexit) 2924 log(LOG_INFO, 2925 "pid %d (%s), uid %d: exited on signal %d%s\n", 2926 p->p_pid, p->p_comm, 2927 td->td_ucred ? td->td_ucred->cr_uid : -1, 2928 sig &~ WCOREFLAG, 2929 sig & WCOREFLAG ? " (core dumped)" : ""); 2930 } else 2931 PROC_UNLOCK(p); 2932 exit1(td, W_EXITCODE(0, sig)); 2933 /* NOTREACHED */ 2934 } 2935 2936 /* 2937 * Send queued SIGCHLD to parent when child process's state 2938 * is changed. 2939 */ 2940 static void 2941 sigparent(struct proc *p, int reason, int status) 2942 { 2943 PROC_LOCK_ASSERT(p, MA_OWNED); 2944 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2945 2946 if (p->p_ksi != NULL) { 2947 p->p_ksi->ksi_signo = SIGCHLD; 2948 p->p_ksi->ksi_code = reason; 2949 p->p_ksi->ksi_status = status; 2950 p->p_ksi->ksi_pid = p->p_pid; 2951 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2952 if (KSI_ONQ(p->p_ksi)) 2953 return; 2954 } 2955 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2956 } 2957 2958 static void 2959 childproc_jobstate(struct proc *p, int reason, int status) 2960 { 2961 struct sigacts *ps; 2962 2963 PROC_LOCK_ASSERT(p, MA_OWNED); 2964 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2965 2966 /* 2967 * Wake up parent sleeping in kern_wait(), also send 2968 * SIGCHLD to parent, but SIGCHLD does not guarantee 2969 * that parent will awake, because parent may masked 2970 * the signal. 2971 */ 2972 p->p_pptr->p_flag |= P_STATCHILD; 2973 wakeup(p->p_pptr); 2974 2975 ps = p->p_pptr->p_sigacts; 2976 mtx_lock(&ps->ps_mtx); 2977 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2978 mtx_unlock(&ps->ps_mtx); 2979 sigparent(p, reason, status); 2980 } else 2981 mtx_unlock(&ps->ps_mtx); 2982 } 2983 2984 void 2985 childproc_stopped(struct proc *p, int reason) 2986 { 2987 childproc_jobstate(p, reason, p->p_xstat); 2988 } 2989 2990 void 2991 childproc_continued(struct proc *p) 2992 { 2993 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2994 } 2995 2996 void 2997 childproc_exited(struct proc *p) 2998 { 2999 int reason; 3000 int status = p->p_xstat; /* convert to int */ 3001 3002 reason = CLD_EXITED; 3003 if (WCOREDUMP(status)) 3004 reason = CLD_DUMPED; 3005 else if (WIFSIGNALED(status)) 3006 reason = CLD_KILLED; 3007 /* 3008 * XXX avoid calling wakeup(p->p_pptr), the work is 3009 * done in exit1(). 3010 */ 3011 sigparent(p, reason, status); 3012 } 3013 3014 /* 3015 * We only have 1 character for the core count in the format 3016 * string, so the range will be 0-9 3017 */ 3018 #define MAX_NUM_CORES 10 3019 static int num_cores = 5; 3020 3021 static int 3022 sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3023 { 3024 int error; 3025 int new_val; 3026 3027 new_val = num_cores; 3028 error = sysctl_handle_int(oidp, &new_val, 0, req); 3029 if (error != 0 || req->newptr == NULL) 3030 return (error); 3031 if (new_val > MAX_NUM_CORES) 3032 new_val = MAX_NUM_CORES; 3033 if (new_val < 0) 3034 new_val = 0; 3035 num_cores = new_val; 3036 return (0); 3037 } 3038 SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3039 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3040 3041 #if defined(COMPRESS_USER_CORES) 3042 int compress_user_cores = 1; 3043 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3044 &compress_user_cores, 0, ""); 3045 3046 int compress_user_cores_gzlevel = -1; /* default level */ 3047 SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3048 &compress_user_cores_gzlevel, -1, "user core gz compression level"); 3049 3050 #define GZ_SUFFIX ".gz" 3051 #define GZ_SUFFIX_LEN 3 3052 #endif 3053 3054 static char corefilename[MAXPATHLEN] = {"%N.core"}; 3055 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3056 sizeof(corefilename), "process corefile name format string"); 3057 3058 /* 3059 * expand_name(name, uid, pid, td, compress) 3060 * Expand the name described in corefilename, using name, uid, and pid. 3061 * corefilename is a printf-like string, with three format specifiers: 3062 * %N name of process ("name") 3063 * %P process id (pid) 3064 * %U user id (uid) 3065 * For example, "%N.core" is the default; they can be disabled completely 3066 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3067 * This is controlled by the sysctl variable kern.corefile (see above). 3068 */ 3069 static char * 3070 expand_name(const char *name, uid_t uid, pid_t pid, struct thread *td, 3071 int compress) 3072 { 3073 struct sbuf sb; 3074 const char *format; 3075 char *temp; 3076 size_t i; 3077 int indexpos; 3078 char *hostname; 3079 3080 hostname = NULL; 3081 format = corefilename; 3082 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 3083 if (temp == NULL) 3084 return (NULL); 3085 indexpos = -1; 3086 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 3087 for (i = 0; format[i]; i++) { 3088 switch (format[i]) { 3089 case '%': /* Format character */ 3090 i++; 3091 switch (format[i]) { 3092 case '%': 3093 sbuf_putc(&sb, '%'); 3094 break; 3095 case 'H': /* hostname */ 3096 if (hostname == NULL) { 3097 hostname = malloc(MAXHOSTNAMELEN, 3098 M_TEMP, M_NOWAIT); 3099 if (hostname == NULL) { 3100 log(LOG_ERR, 3101 "pid %ld (%s), uid (%lu): " 3102 "unable to alloc memory " 3103 "for corefile hostname\n", 3104 (long)pid, name, 3105 (u_long)uid); 3106 goto nomem; 3107 } 3108 } 3109 getcredhostname(td->td_ucred, hostname, 3110 MAXHOSTNAMELEN); 3111 sbuf_printf(&sb, "%s", hostname); 3112 break; 3113 case 'I': /* autoincrementing index */ 3114 sbuf_printf(&sb, ""); 3115 indexpos = sbuf_len(&sb) - 1; 3116 break; 3117 case 'N': /* process name */ 3118 sbuf_printf(&sb, "%s", name); 3119 break; 3120 case 'P': /* process id */ 3121 sbuf_printf(&sb, "%u", pid); 3122 break; 3123 case 'U': /* user id */ 3124 sbuf_printf(&sb, "%u", uid); 3125 break; 3126 default: 3127 log(LOG_ERR, 3128 "Unknown format character %c in " 3129 "corename `%s'\n", format[i], format); 3130 } 3131 break; 3132 default: 3133 sbuf_putc(&sb, format[i]); 3134 } 3135 } 3136 free(hostname, M_TEMP); 3137 #ifdef COMPRESS_USER_CORES 3138 if (compress) { 3139 sbuf_printf(&sb, GZ_SUFFIX); 3140 } 3141 #endif 3142 if (sbuf_error(&sb) != 0) { 3143 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3144 "long\n", (long)pid, name, (u_long)uid); 3145 nomem: 3146 sbuf_delete(&sb); 3147 free(temp, M_TEMP); 3148 return (NULL); 3149 } 3150 sbuf_finish(&sb); 3151 sbuf_delete(&sb); 3152 3153 /* 3154 * If the core format has a %I in it, then we need to check 3155 * for existing corefiles before returning a name. 3156 * To do this we iterate over 0..num_cores to find a 3157 * non-existing core file name to use. 3158 */ 3159 if (indexpos != -1) { 3160 struct nameidata nd; 3161 int error, n; 3162 int flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3163 int cmode = S_IRUSR | S_IWUSR; 3164 int vfslocked; 3165 3166 for (n = 0; n < num_cores; n++) { 3167 temp[indexpos] = '' + n; 3168 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, 3169 temp, td); 3170 error = vn_open(&nd, &flags, cmode, NULL); 3171 if (error) { 3172 if (error == EEXIST) { 3173 continue; 3174 } 3175 log(LOG_ERR, 3176 "pid %d (%s), uid (%u): Path `%s' failed " 3177 "on initial open test, error = %d\n", 3178 pid, name, uid, temp, error); 3179 free(temp, M_TEMP); 3180 return (NULL); 3181 } 3182 vfslocked = NDHASGIANT(&nd); 3183 NDFREE(&nd, NDF_ONLY_PNBUF); 3184 VOP_UNLOCK(nd.ni_vp, 0); 3185 error = vn_close(nd.ni_vp, FWRITE, td->td_ucred, td); 3186 VFS_UNLOCK_GIANT(vfslocked); 3187 if (error) { 3188 log(LOG_ERR, 3189 "pid %d (%s), uid (%u): Path `%s' failed " 3190 "on close after initial open test, " 3191 "error = %d\n", 3192 pid, name, uid, temp, error); 3193 free(temp, M_TEMP); 3194 return (NULL); 3195 } 3196 break; 3197 } 3198 } 3199 return (temp); 3200 } 3201 3202 /* 3203 * Dump a process' core. The main routine does some 3204 * policy checking, and creates the name of the coredump; 3205 * then it passes on a vnode and a size limit to the process-specific 3206 * coredump routine if there is one; if there _is not_ one, it returns 3207 * ENOSYS; otherwise it returns the error from the process-specific routine. 3208 */ 3209 3210 static int 3211 coredump(struct thread *td) 3212 { 3213 struct proc *p = td->td_proc; 3214 register struct vnode *vp; 3215 register struct ucred *cred = td->td_ucred; 3216 struct flock lf; 3217 struct nameidata nd; 3218 struct vattr vattr; 3219 int error, error1, flags, locked; 3220 struct mount *mp; 3221 char *name; /* name of corefile */ 3222 off_t limit; 3223 int vfslocked; 3224 int compress; 3225 3226 #ifdef COMPRESS_USER_CORES 3227 compress = compress_user_cores; 3228 #else 3229 compress = 0; 3230 #endif 3231 PROC_LOCK_ASSERT(p, MA_OWNED); 3232 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3233 _STOPEVENT(p, S_CORE, 0); 3234 3235 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid, td, 3236 compress); 3237 if (name == NULL) { 3238 PROC_UNLOCK(p); 3239 #ifdef AUDIT 3240 audit_proc_coredump(td, NULL, EINVAL); 3241 #endif 3242 return (EINVAL); 3243 } 3244 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3245 PROC_UNLOCK(p); 3246 #ifdef AUDIT 3247 audit_proc_coredump(td, name, EFAULT); 3248 #endif 3249 free(name, M_TEMP); 3250 return (EFAULT); 3251 } 3252 3253 /* 3254 * Note that the bulk of limit checking is done after 3255 * the corefile is created. The exception is if the limit 3256 * for corefiles is 0, in which case we don't bother 3257 * creating the corefile at all. This layout means that 3258 * a corefile is truncated instead of not being created, 3259 * if it is larger than the limit. 3260 */ 3261 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3262 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3263 PROC_UNLOCK(p); 3264 #ifdef AUDIT 3265 audit_proc_coredump(td, name, EFBIG); 3266 #endif 3267 free(name, M_TEMP); 3268 return (EFBIG); 3269 } 3270 PROC_UNLOCK(p); 3271 3272 restart: 3273 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3274 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3275 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3276 cred, NULL); 3277 if (error) { 3278 #ifdef AUDIT 3279 audit_proc_coredump(td, name, error); 3280 #endif 3281 free(name, M_TEMP); 3282 return (error); 3283 } 3284 vfslocked = NDHASGIANT(&nd); 3285 NDFREE(&nd, NDF_ONLY_PNBUF); 3286 vp = nd.ni_vp; 3287 3288 /* Don't dump to non-regular files or files with links. */ 3289 if (vp->v_type != VREG || 3290 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3291 VOP_UNLOCK(vp, 0); 3292 error = EFAULT; 3293 goto close; 3294 } 3295 3296 VOP_UNLOCK(vp, 0); 3297 lf.l_whence = SEEK_SET; 3298 lf.l_start = 0; 3299 lf.l_len = 0; 3300 lf.l_type = F_WRLCK; 3301 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3302 3303 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3304 lf.l_type = F_UNLCK; 3305 if (locked) 3306 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3307 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3308 goto out; 3309 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3310 goto out; 3311 VFS_UNLOCK_GIANT(vfslocked); 3312 goto restart; 3313 } 3314 3315 VATTR_NULL(&vattr); 3316 vattr.va_size = 0; 3317 if (set_core_nodump_flag) 3318 vattr.va_flags = UF_NODUMP; 3319 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3320 VOP_SETATTR(vp, &vattr, cred); 3321 VOP_UNLOCK(vp, 0); 3322 vn_finished_write(mp); 3323 PROC_LOCK(p); 3324 p->p_acflag |= ACORE; 3325 PROC_UNLOCK(p); 3326 3327 error = p->p_sysent->sv_coredump ? 3328 p->p_sysent->sv_coredump(td, vp, limit, compress ? IMGACT_CORE_COMPRESS : 0) : 3329 ENOSYS; 3330 3331 if (locked) { 3332 lf.l_type = F_UNLCK; 3333 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3334 } 3335 close: 3336 error1 = vn_close(vp, FWRITE, cred, td); 3337 if (error == 0) 3338 error = error1; 3339 out: 3340 #ifdef AUDIT 3341 audit_proc_coredump(td, name, error); 3342 #endif 3343 free(name, M_TEMP); 3344 VFS_UNLOCK_GIANT(vfslocked); 3345 return (error); 3346 } 3347 3348 /* 3349 * Nonexistent system call-- signal process (may want to handle it). Flag 3350 * error in case process won't see signal immediately (blocked or ignored). 3351 */ 3352 #ifndef _SYS_SYSPROTO_H_ 3353 struct nosys_args { 3354 int dummy; 3355 }; 3356 #endif 3357 /* ARGSUSED */ 3358 int 3359 nosys(td, args) 3360 struct thread *td; 3361 struct nosys_args *args; 3362 { 3363 struct proc *p = td->td_proc; 3364 3365 PROC_LOCK(p); 3366 tdsignal(td, SIGSYS); 3367 PROC_UNLOCK(p); 3368 return (ENOSYS); 3369 } 3370 3371 /* 3372 * Send a SIGIO or SIGURG signal to a process or process group using stored 3373 * credentials rather than those of the current process. 3374 */ 3375 void 3376 pgsigio(sigiop, sig, checkctty) 3377 struct sigio **sigiop; 3378 int sig, checkctty; 3379 { 3380 ksiginfo_t ksi; 3381 struct sigio *sigio; 3382 3383 ksiginfo_init(&ksi); 3384 ksi.ksi_signo = sig; 3385 ksi.ksi_code = SI_KERNEL; 3386 3387 SIGIO_LOCK(); 3388 sigio = *sigiop; 3389 if (sigio == NULL) { 3390 SIGIO_UNLOCK(); 3391 return; 3392 } 3393 if (sigio->sio_pgid > 0) { 3394 PROC_LOCK(sigio->sio_proc); 3395 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3396 kern_psignal(sigio->sio_proc, sig); 3397 PROC_UNLOCK(sigio->sio_proc); 3398 } else if (sigio->sio_pgid < 0) { 3399 struct proc *p; 3400 3401 PGRP_LOCK(sigio->sio_pgrp); 3402 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3403 PROC_LOCK(p); 3404 if (p->p_state == PRS_NORMAL && 3405 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3406 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3407 kern_psignal(p, sig); 3408 PROC_UNLOCK(p); 3409 } 3410 PGRP_UNLOCK(sigio->sio_pgrp); 3411 } 3412 SIGIO_UNLOCK(); 3413 } 3414 3415 static int 3416 filt_sigattach(struct knote *kn) 3417 { 3418 struct proc *p = curproc; 3419 3420 kn->kn_ptr.p_proc = p; 3421 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3422 3423 knlist_add(&p->p_klist, kn, 0); 3424 3425 return (0); 3426 } 3427 3428 static void 3429 filt_sigdetach(struct knote *kn) 3430 { 3431 struct proc *p = kn->kn_ptr.p_proc; 3432 3433 knlist_remove(&p->p_klist, kn, 0); 3434 } 3435 3436 /* 3437 * signal knotes are shared with proc knotes, so we apply a mask to 3438 * the hint in order to differentiate them from process hints. This 3439 * could be avoided by using a signal-specific knote list, but probably 3440 * isn't worth the trouble. 3441 */ 3442 static int 3443 filt_signal(struct knote *kn, long hint) 3444 { 3445 3446 if (hint & NOTE_SIGNAL) { 3447 hint &= ~NOTE_SIGNAL; 3448 3449 if (kn->kn_id == hint) 3450 kn->kn_data++; 3451 } 3452 return (kn->kn_data != 0); 3453 } 3454 3455 struct sigacts * 3456 sigacts_alloc(void) 3457 { 3458 struct sigacts *ps; 3459 3460 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3461 ps->ps_refcnt = 1; 3462 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3463 return (ps); 3464 } 3465 3466 void 3467 sigacts_free(struct sigacts *ps) 3468 { 3469 3470 mtx_lock(&ps->ps_mtx); 3471 ps->ps_refcnt--; 3472 if (ps->ps_refcnt == 0) { 3473 mtx_destroy(&ps->ps_mtx); 3474 free(ps, M_SUBPROC); 3475 } else 3476 mtx_unlock(&ps->ps_mtx); 3477 } 3478 3479 struct sigacts * 3480 sigacts_hold(struct sigacts *ps) 3481 { 3482 mtx_lock(&ps->ps_mtx); 3483 ps->ps_refcnt++; 3484 mtx_unlock(&ps->ps_mtx); 3485 return (ps); 3486 } 3487 3488 void 3489 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3490 { 3491 3492 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3493 mtx_lock(&src->ps_mtx); 3494 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3495 mtx_unlock(&src->ps_mtx); 3496 } 3497 3498 int 3499 sigacts_shared(struct sigacts *ps) 3500 { 3501 int shared; 3502 3503 mtx_lock(&ps->ps_mtx); 3504 shared = ps->ps_refcnt > 1; 3505 mtx_unlock(&ps->ps_mtx); 3506 return (shared); 3507 }
Cache object: 5c2aa53377ac2690de62a4a89a1b172d
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