Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_sig.c
Version:
- FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
SearchContext: - none - 3 - 10
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/8.4/sys/kern/kern_sig.c 247350 2013-02-26 21:05:06Z jhb $"); 39 40 #include "opt_compat.h" 41 #include "opt_kdtrace.h" 42 #include "opt_ktrace.h" 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/signalvar.h> 47 #include <sys/vnode.h> 48 #include <sys/acct.h> 49 #include <sys/condvar.h> 50 #include <sys/event.h> 51 #include <sys/fcntl.h> 52 #include <sys/kernel.h> 53 #include <sys/ktr.h> 54 #include <sys/ktrace.h> 55 #include <sys/lock.h> 56 #include <sys/malloc.h> 57 #include <sys/mutex.h> 58 #include <sys/namei.h> 59 #include <sys/proc.h> 60 #include <sys/posix4.h> 61 #include <sys/pioctl.h> 62 #include <sys/resourcevar.h> 63 #include <sys/sdt.h> 64 #include <sys/sbuf.h> 65 #include <sys/sleepqueue.h> 66 #include <sys/smp.h> 67 #include <sys/stat.h> 68 #include <sys/sx.h> 69 #include <sys/syscallsubr.h> 70 #include <sys/sysctl.h> 71 #include <sys/sysent.h> 72 #include <sys/syslog.h> 73 #include <sys/sysproto.h> 74 #include <sys/timers.h> 75 #include <sys/unistd.h> 76 #include <sys/wait.h> 77 #include <vm/vm.h> 78 #include <vm/vm_extern.h> 79 #include <vm/uma.h> 80 81 #include <machine/cpu.h> 82 83 #include <security/audit/audit.h> 84 85 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 86 87 SDT_PROVIDER_DECLARE(proc); 88 SDT_PROBE_DEFINE(proc, kernel, , signal_send, signal-send); 89 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 0, "struct thread *"); 90 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 1, "struct proc *"); 91 SDT_PROBE_ARGTYPE(proc, kernel, , signal_send, 2, "int"); 92 SDT_PROBE_DEFINE(proc, kernel, , signal_clear, signal-clear); 93 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 0, "int"); 94 SDT_PROBE_ARGTYPE(proc, kernel, , signal_clear, 1, "ksiginfo_t *"); 95 SDT_PROBE_DEFINE(proc, kernel, , signal_discard, signal-discard); 96 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 0, "struct thread *"); 97 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 1, "struct proc *"); 98 SDT_PROBE_ARGTYPE(proc, kernel, , signal_discard, 2, "int"); 99 100 static int coredump(struct thread *); 101 static char *expand_name(const char *, uid_t, pid_t); 102 static int killpg1(struct thread *td, int sig, int pgid, int all, 103 ksiginfo_t *ksi); 104 static int issignal(struct thread *td, int stop_allowed); 105 static int sigprop(int sig); 106 static void tdsigwakeup(struct thread *, int, sig_t, int); 107 static void sig_suspend_threads(struct thread *, struct proc *, int); 108 static int filt_sigattach(struct knote *kn); 109 static void filt_sigdetach(struct knote *kn); 110 static int filt_signal(struct knote *kn, long hint); 111 static struct thread *sigtd(struct proc *p, int sig, int prop); 112 static void sigqueue_start(void); 113 114 static uma_zone_t ksiginfo_zone = NULL; 115 struct filterops sig_filtops = 116 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 117 118 int kern_logsigexit = 1; 119 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 120 &kern_logsigexit, 0, 121 "Log processes quitting on abnormal signals to syslog(3)"); 122 123 static int kern_forcesigexit = 1; 124 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 125 &kern_forcesigexit, 0, "Force trap signal to be handled"); 126 127 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 128 129 static int max_pending_per_proc = 128; 130 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 131 &max_pending_per_proc, 0, "Max pending signals per proc"); 132 133 static int preallocate_siginfo = 1024; 134 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 135 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 136 &preallocate_siginfo, 0, "Preallocated signal memory size"); 137 138 static int signal_overflow = 0; 139 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 140 &signal_overflow, 0, "Number of signals overflew"); 141 142 static int signal_alloc_fail = 0; 143 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 144 &signal_alloc_fail, 0, "signals failed to be allocated"); 145 146 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 147 148 /* 149 * Policy -- Can ucred cr1 send SIGIO to process cr2? 150 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 151 * in the right situations. 152 */ 153 #define CANSIGIO(cr1, cr2) \ 154 ((cr1)->cr_uid == 0 || \ 155 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 156 (cr1)->cr_uid == (cr2)->cr_ruid || \ 157 (cr1)->cr_ruid == (cr2)->cr_uid || \ 158 (cr1)->cr_uid == (cr2)->cr_uid) 159 160 int sugid_coredump; 161 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 162 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 163 164 static int do_coredump = 1; 165 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 166 &do_coredump, 0, "Enable/Disable coredumps"); 167 168 static int set_core_nodump_flag = 0; 169 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 170 0, "Enable setting the NODUMP flag on coredump files"); 171 172 /* 173 * Signal properties and actions. 174 * The array below categorizes the signals and their default actions 175 * according to the following properties: 176 */ 177 #define SA_KILL 0x01 /* terminates process by default */ 178 #define SA_CORE 0x02 /* ditto and coredumps */ 179 #define SA_STOP 0x04 /* suspend process */ 180 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 181 #define SA_IGNORE 0x10 /* ignore by default */ 182 #define SA_CONT 0x20 /* continue if suspended */ 183 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 184 #define SA_PROC 0x80 /* deliverable to any thread */ 185 186 static int sigproptbl[NSIG] = { 187 SA_KILL|SA_PROC, /* SIGHUP */ 188 SA_KILL|SA_PROC, /* SIGINT */ 189 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 190 SA_KILL|SA_CORE, /* SIGILL */ 191 SA_KILL|SA_CORE, /* SIGTRAP */ 192 SA_KILL|SA_CORE, /* SIGABRT */ 193 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 194 SA_KILL|SA_CORE, /* SIGFPE */ 195 SA_KILL|SA_PROC, /* SIGKILL */ 196 SA_KILL|SA_CORE, /* SIGBUS */ 197 SA_KILL|SA_CORE, /* SIGSEGV */ 198 SA_KILL|SA_CORE, /* SIGSYS */ 199 SA_KILL|SA_PROC, /* SIGPIPE */ 200 SA_KILL|SA_PROC, /* SIGALRM */ 201 SA_KILL|SA_PROC, /* SIGTERM */ 202 SA_IGNORE|SA_PROC, /* SIGURG */ 203 SA_STOP|SA_PROC, /* SIGSTOP */ 204 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 205 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 206 SA_IGNORE|SA_PROC, /* SIGCHLD */ 207 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 208 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 209 SA_IGNORE|SA_PROC, /* SIGIO */ 210 SA_KILL, /* SIGXCPU */ 211 SA_KILL, /* SIGXFSZ */ 212 SA_KILL|SA_PROC, /* SIGVTALRM */ 213 SA_KILL|SA_PROC, /* SIGPROF */ 214 SA_IGNORE|SA_PROC, /* SIGWINCH */ 215 SA_IGNORE|SA_PROC, /* SIGINFO */ 216 SA_KILL|SA_PROC, /* SIGUSR1 */ 217 SA_KILL|SA_PROC, /* SIGUSR2 */ 218 }; 219 220 static void reschedule_signals(struct proc *p, sigset_t block, int flags); 221 222 static void 223 sigqueue_start(void) 224 { 225 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 226 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 227 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 228 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 229 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 230 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 231 } 232 233 ksiginfo_t * 234 ksiginfo_alloc(int wait) 235 { 236 int flags; 237 238 flags = M_ZERO; 239 if (! wait) 240 flags |= M_NOWAIT; 241 if (ksiginfo_zone != NULL) 242 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 243 return (NULL); 244 } 245 246 void 247 ksiginfo_free(ksiginfo_t *ksi) 248 { 249 uma_zfree(ksiginfo_zone, ksi); 250 } 251 252 static __inline int 253 ksiginfo_tryfree(ksiginfo_t *ksi) 254 { 255 if (!(ksi->ksi_flags & KSI_EXT)) { 256 uma_zfree(ksiginfo_zone, ksi); 257 return (1); 258 } 259 return (0); 260 } 261 262 void 263 sigqueue_init(sigqueue_t *list, struct proc *p) 264 { 265 SIGEMPTYSET(list->sq_signals); 266 SIGEMPTYSET(list->sq_kill); 267 TAILQ_INIT(&list->sq_list); 268 list->sq_proc = p; 269 list->sq_flags = SQ_INIT; 270 } 271 272 /* 273 * Get a signal's ksiginfo. 274 * Return: 275 * 0 - signal not found 276 * others - signal number 277 */ 278 static int 279 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 280 { 281 struct proc *p = sq->sq_proc; 282 struct ksiginfo *ksi, *next; 283 int count = 0; 284 285 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 286 287 if (!SIGISMEMBER(sq->sq_signals, signo)) 288 return (0); 289 290 if (SIGISMEMBER(sq->sq_kill, signo)) { 291 count++; 292 SIGDELSET(sq->sq_kill, signo); 293 } 294 295 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 296 if (ksi->ksi_signo == signo) { 297 if (count == 0) { 298 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 299 ksi->ksi_sigq = NULL; 300 ksiginfo_copy(ksi, si); 301 if (ksiginfo_tryfree(ksi) && p != NULL) 302 p->p_pendingcnt--; 303 } 304 if (++count > 1) 305 break; 306 } 307 } 308 309 if (count <= 1) 310 SIGDELSET(sq->sq_signals, signo); 311 si->ksi_signo = signo; 312 return (signo); 313 } 314 315 void 316 sigqueue_take(ksiginfo_t *ksi) 317 { 318 struct ksiginfo *kp; 319 struct proc *p; 320 sigqueue_t *sq; 321 322 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 323 return; 324 325 p = sq->sq_proc; 326 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 327 ksi->ksi_sigq = NULL; 328 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 329 p->p_pendingcnt--; 330 331 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 332 kp = TAILQ_NEXT(kp, ksi_link)) { 333 if (kp->ksi_signo == ksi->ksi_signo) 334 break; 335 } 336 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 337 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 338 } 339 340 static int 341 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 342 { 343 struct proc *p = sq->sq_proc; 344 struct ksiginfo *ksi; 345 int ret = 0; 346 347 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 348 349 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 350 SIGADDSET(sq->sq_kill, signo); 351 goto out_set_bit; 352 } 353 354 /* directly insert the ksi, don't copy it */ 355 if (si->ksi_flags & KSI_INS) { 356 if (si->ksi_flags & KSI_HEAD) 357 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 358 else 359 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 360 si->ksi_sigq = sq; 361 goto out_set_bit; 362 } 363 364 if (__predict_false(ksiginfo_zone == NULL)) { 365 SIGADDSET(sq->sq_kill, signo); 366 goto out_set_bit; 367 } 368 369 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 370 signal_overflow++; 371 ret = EAGAIN; 372 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 373 signal_alloc_fail++; 374 ret = EAGAIN; 375 } else { 376 if (p != NULL) 377 p->p_pendingcnt++; 378 ksiginfo_copy(si, ksi); 379 ksi->ksi_signo = signo; 380 if (si->ksi_flags & KSI_HEAD) 381 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 382 else 383 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 384 ksi->ksi_sigq = sq; 385 } 386 387 if ((si->ksi_flags & KSI_TRAP) != 0 || 388 (si->ksi_flags & KSI_SIGQ) == 0) { 389 if (ret != 0) 390 SIGADDSET(sq->sq_kill, signo); 391 ret = 0; 392 goto out_set_bit; 393 } 394 395 if (ret != 0) 396 return (ret); 397 398 out_set_bit: 399 SIGADDSET(sq->sq_signals, signo); 400 return (ret); 401 } 402 403 void 404 sigqueue_flush(sigqueue_t *sq) 405 { 406 struct proc *p = sq->sq_proc; 407 ksiginfo_t *ksi; 408 409 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 410 411 if (p != NULL) 412 PROC_LOCK_ASSERT(p, MA_OWNED); 413 414 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 415 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 416 ksi->ksi_sigq = NULL; 417 if (ksiginfo_tryfree(ksi) && p != NULL) 418 p->p_pendingcnt--; 419 } 420 421 SIGEMPTYSET(sq->sq_signals); 422 SIGEMPTYSET(sq->sq_kill); 423 } 424 425 static void 426 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 427 { 428 ksiginfo_t *ksi; 429 430 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 431 432 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 433 SIGADDSET(*set, ksi->ksi_signo); 434 SIGSETOR(*set, sq->sq_kill); 435 } 436 437 static void 438 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 439 { 440 sigset_t tmp, set; 441 struct proc *p1, *p2; 442 ksiginfo_t *ksi, *next; 443 444 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 445 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 446 /* 447 * make a copy, this allows setp to point to src or dst 448 * sq_signals without trouble. 449 */ 450 set = *setp; 451 p1 = src->sq_proc; 452 p2 = dst->sq_proc; 453 /* Move siginfo to target list */ 454 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 455 if (SIGISMEMBER(set, ksi->ksi_signo)) { 456 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 457 if (p1 != NULL) 458 p1->p_pendingcnt--; 459 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 460 ksi->ksi_sigq = dst; 461 if (p2 != NULL) 462 p2->p_pendingcnt++; 463 } 464 } 465 466 /* Move pending bits to target list */ 467 tmp = src->sq_kill; 468 SIGSETAND(tmp, set); 469 SIGSETOR(dst->sq_kill, tmp); 470 SIGSETNAND(src->sq_kill, tmp); 471 472 tmp = src->sq_signals; 473 SIGSETAND(tmp, set); 474 SIGSETOR(dst->sq_signals, tmp); 475 SIGSETNAND(src->sq_signals, tmp); 476 477 /* Finally, rescan src queue and set pending bits for it */ 478 sigqueue_collect_set(src, &src->sq_signals); 479 } 480 481 static void 482 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 483 { 484 sigset_t set; 485 486 SIGEMPTYSET(set); 487 SIGADDSET(set, signo); 488 sigqueue_move_set(src, dst, &set); 489 } 490 491 static void 492 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 493 { 494 struct proc *p = sq->sq_proc; 495 ksiginfo_t *ksi, *next; 496 497 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 498 499 /* Remove siginfo queue */ 500 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 501 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 502 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 503 ksi->ksi_sigq = NULL; 504 if (ksiginfo_tryfree(ksi) && p != NULL) 505 p->p_pendingcnt--; 506 } 507 } 508 SIGSETNAND(sq->sq_kill, *set); 509 SIGSETNAND(sq->sq_signals, *set); 510 /* Finally, rescan queue and set pending bits for it */ 511 sigqueue_collect_set(sq, &sq->sq_signals); 512 } 513 514 void 515 sigqueue_delete(sigqueue_t *sq, int signo) 516 { 517 sigset_t set; 518 519 SIGEMPTYSET(set); 520 SIGADDSET(set, signo); 521 sigqueue_delete_set(sq, &set); 522 } 523 524 /* Remove a set of signals for a process */ 525 static void 526 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 527 { 528 sigqueue_t worklist; 529 struct thread *td0; 530 531 PROC_LOCK_ASSERT(p, MA_OWNED); 532 533 sigqueue_init(&worklist, NULL); 534 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 535 536 FOREACH_THREAD_IN_PROC(p, td0) 537 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 538 539 sigqueue_flush(&worklist); 540 } 541 542 void 543 sigqueue_delete_proc(struct proc *p, int signo) 544 { 545 sigset_t set; 546 547 SIGEMPTYSET(set); 548 SIGADDSET(set, signo); 549 sigqueue_delete_set_proc(p, &set); 550 } 551 552 static void 553 sigqueue_delete_stopmask_proc(struct proc *p) 554 { 555 sigset_t set; 556 557 SIGEMPTYSET(set); 558 SIGADDSET(set, SIGSTOP); 559 SIGADDSET(set, SIGTSTP); 560 SIGADDSET(set, SIGTTIN); 561 SIGADDSET(set, SIGTTOU); 562 sigqueue_delete_set_proc(p, &set); 563 } 564 565 /* 566 * Determine signal that should be delivered to process p, the current 567 * process, 0 if none. If there is a pending stop signal with default 568 * action, the process stops in issignal(). 569 */ 570 int 571 cursig(struct thread *td, int stop_allowed) 572 { 573 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 574 KASSERT(stop_allowed == SIG_STOP_ALLOWED || 575 stop_allowed == SIG_STOP_NOT_ALLOWED, ("cursig: stop_allowed")); 576 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 577 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 578 return (SIGPENDING(td) ? issignal(td, stop_allowed) : 0); 579 } 580 581 /* 582 * Arrange for ast() to handle unmasked pending signals on return to user 583 * mode. This must be called whenever a signal is added to td_sigqueue or 584 * unmasked in td_sigmask. 585 */ 586 void 587 signotify(struct thread *td) 588 { 589 struct proc *p; 590 591 p = td->td_proc; 592 593 PROC_LOCK_ASSERT(p, MA_OWNED); 594 595 if (SIGPENDING(td)) { 596 thread_lock(td); 597 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 598 thread_unlock(td); 599 } 600 } 601 602 int 603 sigonstack(size_t sp) 604 { 605 struct thread *td = curthread; 606 607 return ((td->td_pflags & TDP_ALTSTACK) ? 608 #if defined(COMPAT_43) 609 ((td->td_sigstk.ss_size == 0) ? 610 (td->td_sigstk.ss_flags & SS_ONSTACK) : 611 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 612 #else 613 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 614 #endif 615 : 0); 616 } 617 618 static __inline int 619 sigprop(int sig) 620 { 621 622 if (sig > 0 && sig < NSIG) 623 return (sigproptbl[_SIG_IDX(sig)]); 624 return (0); 625 } 626 627 int 628 sig_ffs(sigset_t *set) 629 { 630 int i; 631 632 for (i = 0; i < _SIG_WORDS; i++) 633 if (set->__bits[i]) 634 return (ffs(set->__bits[i]) + (i * 32)); 635 return (0); 636 } 637 638 /* 639 * kern_sigaction 640 * sigaction 641 * freebsd4_sigaction 642 * osigaction 643 */ 644 int 645 kern_sigaction(td, sig, act, oact, flags) 646 struct thread *td; 647 register int sig; 648 struct sigaction *act, *oact; 649 int flags; 650 { 651 struct sigacts *ps; 652 struct proc *p = td->td_proc; 653 654 if (!_SIG_VALID(sig)) 655 return (EINVAL); 656 657 PROC_LOCK(p); 658 ps = p->p_sigacts; 659 mtx_lock(&ps->ps_mtx); 660 if (oact) { 661 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 662 oact->sa_flags = 0; 663 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 664 oact->sa_flags |= SA_ONSTACK; 665 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 666 oact->sa_flags |= SA_RESTART; 667 if (SIGISMEMBER(ps->ps_sigreset, sig)) 668 oact->sa_flags |= SA_RESETHAND; 669 if (SIGISMEMBER(ps->ps_signodefer, sig)) 670 oact->sa_flags |= SA_NODEFER; 671 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 672 oact->sa_flags |= SA_SIGINFO; 673 oact->sa_sigaction = 674 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 675 } else 676 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 677 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 678 oact->sa_flags |= SA_NOCLDSTOP; 679 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 680 oact->sa_flags |= SA_NOCLDWAIT; 681 } 682 if (act) { 683 if ((sig == SIGKILL || sig == SIGSTOP) && 684 act->sa_handler != SIG_DFL) { 685 mtx_unlock(&ps->ps_mtx); 686 PROC_UNLOCK(p); 687 return (EINVAL); 688 } 689 690 /* 691 * Change setting atomically. 692 */ 693 694 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 695 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 696 if (act->sa_flags & SA_SIGINFO) { 697 ps->ps_sigact[_SIG_IDX(sig)] = 698 (__sighandler_t *)act->sa_sigaction; 699 SIGADDSET(ps->ps_siginfo, sig); 700 } else { 701 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 702 SIGDELSET(ps->ps_siginfo, sig); 703 } 704 if (!(act->sa_flags & SA_RESTART)) 705 SIGADDSET(ps->ps_sigintr, sig); 706 else 707 SIGDELSET(ps->ps_sigintr, sig); 708 if (act->sa_flags & SA_ONSTACK) 709 SIGADDSET(ps->ps_sigonstack, sig); 710 else 711 SIGDELSET(ps->ps_sigonstack, sig); 712 if (act->sa_flags & SA_RESETHAND) 713 SIGADDSET(ps->ps_sigreset, sig); 714 else 715 SIGDELSET(ps->ps_sigreset, sig); 716 if (act->sa_flags & SA_NODEFER) 717 SIGADDSET(ps->ps_signodefer, sig); 718 else 719 SIGDELSET(ps->ps_signodefer, sig); 720 if (sig == SIGCHLD) { 721 if (act->sa_flags & SA_NOCLDSTOP) 722 ps->ps_flag |= PS_NOCLDSTOP; 723 else 724 ps->ps_flag &= ~PS_NOCLDSTOP; 725 if (act->sa_flags & SA_NOCLDWAIT) { 726 /* 727 * Paranoia: since SA_NOCLDWAIT is implemented 728 * by reparenting the dying child to PID 1 (and 729 * trust it to reap the zombie), PID 1 itself 730 * is forbidden to set SA_NOCLDWAIT. 731 */ 732 if (p->p_pid == 1) 733 ps->ps_flag &= ~PS_NOCLDWAIT; 734 else 735 ps->ps_flag |= PS_NOCLDWAIT; 736 } else 737 ps->ps_flag &= ~PS_NOCLDWAIT; 738 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 739 ps->ps_flag |= PS_CLDSIGIGN; 740 else 741 ps->ps_flag &= ~PS_CLDSIGIGN; 742 } 743 /* 744 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 745 * and for signals set to SIG_DFL where the default is to 746 * ignore. However, don't put SIGCONT in ps_sigignore, as we 747 * have to restart the process. 748 */ 749 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 750 (sigprop(sig) & SA_IGNORE && 751 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 752 /* never to be seen again */ 753 sigqueue_delete_proc(p, sig); 754 if (sig != SIGCONT) 755 /* easier in psignal */ 756 SIGADDSET(ps->ps_sigignore, sig); 757 SIGDELSET(ps->ps_sigcatch, sig); 758 } else { 759 SIGDELSET(ps->ps_sigignore, sig); 760 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 761 SIGDELSET(ps->ps_sigcatch, sig); 762 else 763 SIGADDSET(ps->ps_sigcatch, sig); 764 } 765 #ifdef COMPAT_FREEBSD4 766 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 767 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 768 (flags & KSA_FREEBSD4) == 0) 769 SIGDELSET(ps->ps_freebsd4, sig); 770 else 771 SIGADDSET(ps->ps_freebsd4, sig); 772 #endif 773 #ifdef COMPAT_43 774 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 775 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 776 (flags & KSA_OSIGSET) == 0) 777 SIGDELSET(ps->ps_osigset, sig); 778 else 779 SIGADDSET(ps->ps_osigset, sig); 780 #endif 781 } 782 mtx_unlock(&ps->ps_mtx); 783 PROC_UNLOCK(p); 784 return (0); 785 } 786 787 #ifndef _SYS_SYSPROTO_H_ 788 struct sigaction_args { 789 int sig; 790 struct sigaction *act; 791 struct sigaction *oact; 792 }; 793 #endif 794 int 795 sigaction(td, uap) 796 struct thread *td; 797 register struct sigaction_args *uap; 798 { 799 struct sigaction act, oact; 800 register struct sigaction *actp, *oactp; 801 int error; 802 803 actp = (uap->act != NULL) ? &act : NULL; 804 oactp = (uap->oact != NULL) ? &oact : NULL; 805 if (actp) { 806 error = copyin(uap->act, actp, sizeof(act)); 807 if (error) 808 return (error); 809 } 810 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 811 if (oactp && !error) 812 error = copyout(oactp, uap->oact, sizeof(oact)); 813 return (error); 814 } 815 816 #ifdef COMPAT_FREEBSD4 817 #ifndef _SYS_SYSPROTO_H_ 818 struct freebsd4_sigaction_args { 819 int sig; 820 struct sigaction *act; 821 struct sigaction *oact; 822 }; 823 #endif 824 int 825 freebsd4_sigaction(td, uap) 826 struct thread *td; 827 register struct freebsd4_sigaction_args *uap; 828 { 829 struct sigaction act, oact; 830 register struct sigaction *actp, *oactp; 831 int error; 832 833 834 actp = (uap->act != NULL) ? &act : NULL; 835 oactp = (uap->oact != NULL) ? &oact : NULL; 836 if (actp) { 837 error = copyin(uap->act, actp, sizeof(act)); 838 if (error) 839 return (error); 840 } 841 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 842 if (oactp && !error) 843 error = copyout(oactp, uap->oact, sizeof(oact)); 844 return (error); 845 } 846 #endif /* COMAPT_FREEBSD4 */ 847 848 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 849 #ifndef _SYS_SYSPROTO_H_ 850 struct osigaction_args { 851 int signum; 852 struct osigaction *nsa; 853 struct osigaction *osa; 854 }; 855 #endif 856 int 857 osigaction(td, uap) 858 struct thread *td; 859 register struct osigaction_args *uap; 860 { 861 struct osigaction sa; 862 struct sigaction nsa, osa; 863 register struct sigaction *nsap, *osap; 864 int error; 865 866 if (uap->signum <= 0 || uap->signum >= ONSIG) 867 return (EINVAL); 868 869 nsap = (uap->nsa != NULL) ? &nsa : NULL; 870 osap = (uap->osa != NULL) ? &osa : NULL; 871 872 if (nsap) { 873 error = copyin(uap->nsa, &sa, sizeof(sa)); 874 if (error) 875 return (error); 876 nsap->sa_handler = sa.sa_handler; 877 nsap->sa_flags = sa.sa_flags; 878 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 879 } 880 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 881 if (osap && !error) { 882 sa.sa_handler = osap->sa_handler; 883 sa.sa_flags = osap->sa_flags; 884 SIG2OSIG(osap->sa_mask, sa.sa_mask); 885 error = copyout(&sa, uap->osa, sizeof(sa)); 886 } 887 return (error); 888 } 889 890 #if !defined(__i386__) 891 /* Avoid replicating the same stub everywhere */ 892 int 893 osigreturn(td, uap) 894 struct thread *td; 895 struct osigreturn_args *uap; 896 { 897 898 return (nosys(td, (struct nosys_args *)uap)); 899 } 900 #endif 901 #endif /* COMPAT_43 */ 902 903 /* 904 * Initialize signal state for process 0; 905 * set to ignore signals that are ignored by default. 906 */ 907 void 908 siginit(p) 909 struct proc *p; 910 { 911 register int i; 912 struct sigacts *ps; 913 914 PROC_LOCK(p); 915 ps = p->p_sigacts; 916 mtx_lock(&ps->ps_mtx); 917 for (i = 1; i <= NSIG; i++) 918 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 919 SIGADDSET(ps->ps_sigignore, i); 920 mtx_unlock(&ps->ps_mtx); 921 PROC_UNLOCK(p); 922 } 923 924 /* 925 * Reset signals for an exec of the specified process. 926 */ 927 void 928 execsigs(struct proc *p) 929 { 930 struct sigacts *ps; 931 int sig; 932 struct thread *td; 933 934 /* 935 * Reset caught signals. Held signals remain held 936 * through td_sigmask (unless they were caught, 937 * and are now ignored by default). 938 */ 939 PROC_LOCK_ASSERT(p, MA_OWNED); 940 td = FIRST_THREAD_IN_PROC(p); 941 ps = p->p_sigacts; 942 mtx_lock(&ps->ps_mtx); 943 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 944 sig = sig_ffs(&ps->ps_sigcatch); 945 SIGDELSET(ps->ps_sigcatch, sig); 946 if (sigprop(sig) & SA_IGNORE) { 947 if (sig != SIGCONT) 948 SIGADDSET(ps->ps_sigignore, sig); 949 sigqueue_delete_proc(p, sig); 950 } 951 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 952 } 953 /* 954 * Reset stack state to the user stack. 955 * Clear set of signals caught on the signal stack. 956 */ 957 td->td_sigstk.ss_flags = SS_DISABLE; 958 td->td_sigstk.ss_size = 0; 959 td->td_sigstk.ss_sp = 0; 960 td->td_pflags &= ~TDP_ALTSTACK; 961 /* 962 * Reset no zombies if child dies flag as Solaris does. 963 */ 964 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 965 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 966 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 967 mtx_unlock(&ps->ps_mtx); 968 } 969 970 /* 971 * kern_sigprocmask() 972 * 973 * Manipulate signal mask. 974 */ 975 int 976 kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 977 int flags) 978 { 979 sigset_t new_block, oset1; 980 struct proc *p; 981 int error; 982 983 p = td->td_proc; 984 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 985 PROC_LOCK(p); 986 if (oset != NULL) 987 *oset = td->td_sigmask; 988 989 error = 0; 990 SIGEMPTYSET(new_block); 991 if (set != NULL) { 992 switch (how) { 993 case SIG_BLOCK: 994 SIG_CANTMASK(*set); 995 oset1 = td->td_sigmask; 996 SIGSETOR(td->td_sigmask, *set); 997 new_block = td->td_sigmask; 998 SIGSETNAND(new_block, oset1); 999 break; 1000 case SIG_UNBLOCK: 1001 SIGSETNAND(td->td_sigmask, *set); 1002 signotify(td); 1003 break; 1004 case SIG_SETMASK: 1005 SIG_CANTMASK(*set); 1006 oset1 = td->td_sigmask; 1007 if (flags & SIGPROCMASK_OLD) 1008 SIGSETLO(td->td_sigmask, *set); 1009 else 1010 td->td_sigmask = *set; 1011 new_block = td->td_sigmask; 1012 SIGSETNAND(new_block, oset1); 1013 signotify(td); 1014 break; 1015 default: 1016 error = EINVAL; 1017 break; 1018 } 1019 } 1020 1021 /* 1022 * The new_block set contains signals that were not previously 1023 * blocked, but are blocked now. 1024 * 1025 * In case we block any signal that was not previously blocked 1026 * for td, and process has the signal pending, try to schedule 1027 * signal delivery to some thread that does not block the signal, 1028 * possibly waking it up. 1029 */ 1030 if (p->p_numthreads != 1) 1031 reschedule_signals(p, new_block, flags); 1032 1033 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1034 PROC_UNLOCK(p); 1035 return (error); 1036 } 1037 1038 #ifndef _SYS_SYSPROTO_H_ 1039 struct sigprocmask_args { 1040 int how; 1041 const sigset_t *set; 1042 sigset_t *oset; 1043 }; 1044 #endif 1045 int 1046 sigprocmask(td, uap) 1047 register struct thread *td; 1048 struct sigprocmask_args *uap; 1049 { 1050 sigset_t set, oset; 1051 sigset_t *setp, *osetp; 1052 int error; 1053 1054 setp = (uap->set != NULL) ? &set : NULL; 1055 osetp = (uap->oset != NULL) ? &oset : NULL; 1056 if (setp) { 1057 error = copyin(uap->set, setp, sizeof(set)); 1058 if (error) 1059 return (error); 1060 } 1061 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1062 if (osetp && !error) { 1063 error = copyout(osetp, uap->oset, sizeof(oset)); 1064 } 1065 return (error); 1066 } 1067 1068 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1069 #ifndef _SYS_SYSPROTO_H_ 1070 struct osigprocmask_args { 1071 int how; 1072 osigset_t mask; 1073 }; 1074 #endif 1075 int 1076 osigprocmask(td, uap) 1077 register struct thread *td; 1078 struct osigprocmask_args *uap; 1079 { 1080 sigset_t set, oset; 1081 int error; 1082 1083 OSIG2SIG(uap->mask, set); 1084 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1085 SIG2OSIG(oset, td->td_retval[0]); 1086 return (error); 1087 } 1088 #endif /* COMPAT_43 */ 1089 1090 int 1091 sigwait(struct thread *td, struct sigwait_args *uap) 1092 { 1093 ksiginfo_t ksi; 1094 sigset_t set; 1095 int error; 1096 1097 error = copyin(uap->set, &set, sizeof(set)); 1098 if (error) { 1099 td->td_retval[0] = error; 1100 return (0); 1101 } 1102 1103 error = kern_sigtimedwait(td, set, &ksi, NULL); 1104 if (error) { 1105 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1106 error = ERESTART; 1107 if (error == ERESTART) 1108 return (error); 1109 td->td_retval[0] = error; 1110 return (0); 1111 } 1112 1113 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1114 td->td_retval[0] = error; 1115 return (0); 1116 } 1117 1118 int 1119 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1120 { 1121 struct timespec ts; 1122 struct timespec *timeout; 1123 sigset_t set; 1124 ksiginfo_t ksi; 1125 int error; 1126 1127 if (uap->timeout) { 1128 error = copyin(uap->timeout, &ts, sizeof(ts)); 1129 if (error) 1130 return (error); 1131 1132 timeout = &ts; 1133 } else 1134 timeout = NULL; 1135 1136 error = copyin(uap->set, &set, sizeof(set)); 1137 if (error) 1138 return (error); 1139 1140 error = kern_sigtimedwait(td, set, &ksi, timeout); 1141 if (error) 1142 return (error); 1143 1144 if (uap->info) 1145 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1146 1147 if (error == 0) 1148 td->td_retval[0] = ksi.ksi_signo; 1149 return (error); 1150 } 1151 1152 int 1153 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1154 { 1155 ksiginfo_t ksi; 1156 sigset_t set; 1157 int error; 1158 1159 error = copyin(uap->set, &set, sizeof(set)); 1160 if (error) 1161 return (error); 1162 1163 error = kern_sigtimedwait(td, set, &ksi, NULL); 1164 if (error) 1165 return (error); 1166 1167 if (uap->info) 1168 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1169 1170 if (error == 0) 1171 td->td_retval[0] = ksi.ksi_signo; 1172 return (error); 1173 } 1174 1175 int 1176 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1177 struct timespec *timeout) 1178 { 1179 struct sigacts *ps; 1180 sigset_t savedmask; 1181 struct proc *p; 1182 int error, sig, hz, i, timevalid = 0; 1183 struct timespec rts, ets, ts; 1184 struct timeval tv; 1185 1186 p = td->td_proc; 1187 error = 0; 1188 sig = 0; 1189 ets.tv_sec = 0; 1190 ets.tv_nsec = 0; 1191 SIG_CANTMASK(waitset); 1192 1193 PROC_LOCK(p); 1194 ps = p->p_sigacts; 1195 savedmask = td->td_sigmask; 1196 if (timeout) { 1197 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1198 timevalid = 1; 1199 getnanouptime(&rts); 1200 ets = rts; 1201 timespecadd(&ets, timeout); 1202 } 1203 } 1204 1205 restart: 1206 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1207 if (!SIGISMEMBER(waitset, i)) 1208 continue; 1209 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1210 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1211 sigqueue_move(&p->p_sigqueue, 1212 &td->td_sigqueue, i); 1213 } else 1214 continue; 1215 } 1216 1217 SIGFILLSET(td->td_sigmask); 1218 SIG_CANTMASK(td->td_sigmask); 1219 SIGDELSET(td->td_sigmask, i); 1220 mtx_lock(&ps->ps_mtx); 1221 sig = cursig(td, SIG_STOP_ALLOWED); 1222 mtx_unlock(&ps->ps_mtx); 1223 if (sig) 1224 goto out; 1225 else { 1226 /* 1227 * Because cursig() may have stopped current thread, 1228 * after it is resumed, things may have already been 1229 * changed, it should rescan any pending signals. 1230 */ 1231 goto restart; 1232 } 1233 } 1234 1235 if (error) 1236 goto out; 1237 1238 /* 1239 * POSIX says this must be checked after looking for pending 1240 * signals. 1241 */ 1242 if (timeout) { 1243 if (!timevalid) { 1244 error = EINVAL; 1245 goto out; 1246 } 1247 getnanouptime(&rts); 1248 if (timespeccmp(&rts, &ets, >=)) { 1249 error = EAGAIN; 1250 goto out; 1251 } 1252 ts = ets; 1253 timespecsub(&ts, &rts); 1254 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1255 hz = tvtohz(&tv); 1256 } else 1257 hz = 0; 1258 1259 td->td_sigmask = savedmask; 1260 SIGSETNAND(td->td_sigmask, waitset); 1261 signotify(td); 1262 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1263 if (timeout) { 1264 if (error == ERESTART) { 1265 /* timeout can not be restarted. */ 1266 error = EINTR; 1267 } else if (error == EAGAIN) { 1268 /* will calculate timeout by ourself. */ 1269 error = 0; 1270 } 1271 } 1272 goto restart; 1273 1274 out: 1275 td->td_sigmask = savedmask; 1276 signotify(td); 1277 if (sig) { 1278 ksiginfo_init(ksi); 1279 sigqueue_get(&td->td_sigqueue, sig, ksi); 1280 ksi->ksi_signo = sig; 1281 1282 SDT_PROBE(proc, kernel, , signal_clear, sig, ksi, 0, 0, 0); 1283 1284 if (ksi->ksi_code == SI_TIMER) 1285 itimer_accept(p, ksi->ksi_timerid, ksi); 1286 error = 0; 1287 1288 #ifdef KTRACE 1289 if (KTRPOINT(td, KTR_PSIG)) { 1290 sig_t action; 1291 1292 mtx_lock(&ps->ps_mtx); 1293 action = ps->ps_sigact[_SIG_IDX(sig)]; 1294 mtx_unlock(&ps->ps_mtx); 1295 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1296 } 1297 #endif 1298 if (sig == SIGKILL) 1299 sigexit(td, sig); 1300 } 1301 PROC_UNLOCK(p); 1302 return (error); 1303 } 1304 1305 #ifndef _SYS_SYSPROTO_H_ 1306 struct sigpending_args { 1307 sigset_t *set; 1308 }; 1309 #endif 1310 int 1311 sigpending(td, uap) 1312 struct thread *td; 1313 struct sigpending_args *uap; 1314 { 1315 struct proc *p = td->td_proc; 1316 sigset_t pending; 1317 1318 PROC_LOCK(p); 1319 pending = p->p_sigqueue.sq_signals; 1320 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1321 PROC_UNLOCK(p); 1322 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1323 } 1324 1325 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1326 #ifndef _SYS_SYSPROTO_H_ 1327 struct osigpending_args { 1328 int dummy; 1329 }; 1330 #endif 1331 int 1332 osigpending(td, uap) 1333 struct thread *td; 1334 struct osigpending_args *uap; 1335 { 1336 struct proc *p = td->td_proc; 1337 sigset_t pending; 1338 1339 PROC_LOCK(p); 1340 pending = p->p_sigqueue.sq_signals; 1341 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1342 PROC_UNLOCK(p); 1343 SIG2OSIG(pending, td->td_retval[0]); 1344 return (0); 1345 } 1346 #endif /* COMPAT_43 */ 1347 1348 #if defined(COMPAT_43) 1349 /* 1350 * Generalized interface signal handler, 4.3-compatible. 1351 */ 1352 #ifndef _SYS_SYSPROTO_H_ 1353 struct osigvec_args { 1354 int signum; 1355 struct sigvec *nsv; 1356 struct sigvec *osv; 1357 }; 1358 #endif 1359 /* ARGSUSED */ 1360 int 1361 osigvec(td, uap) 1362 struct thread *td; 1363 register struct osigvec_args *uap; 1364 { 1365 struct sigvec vec; 1366 struct sigaction nsa, osa; 1367 register struct sigaction *nsap, *osap; 1368 int error; 1369 1370 if (uap->signum <= 0 || uap->signum >= ONSIG) 1371 return (EINVAL); 1372 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1373 osap = (uap->osv != NULL) ? &osa : NULL; 1374 if (nsap) { 1375 error = copyin(uap->nsv, &vec, sizeof(vec)); 1376 if (error) 1377 return (error); 1378 nsap->sa_handler = vec.sv_handler; 1379 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1380 nsap->sa_flags = vec.sv_flags; 1381 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1382 } 1383 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1384 if (osap && !error) { 1385 vec.sv_handler = osap->sa_handler; 1386 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1387 vec.sv_flags = osap->sa_flags; 1388 vec.sv_flags &= ~SA_NOCLDWAIT; 1389 vec.sv_flags ^= SA_RESTART; 1390 error = copyout(&vec, uap->osv, sizeof(vec)); 1391 } 1392 return (error); 1393 } 1394 1395 #ifndef _SYS_SYSPROTO_H_ 1396 struct osigblock_args { 1397 int mask; 1398 }; 1399 #endif 1400 int 1401 osigblock(td, uap) 1402 register struct thread *td; 1403 struct osigblock_args *uap; 1404 { 1405 sigset_t set, oset; 1406 1407 OSIG2SIG(uap->mask, set); 1408 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1409 SIG2OSIG(oset, td->td_retval[0]); 1410 return (0); 1411 } 1412 1413 #ifndef _SYS_SYSPROTO_H_ 1414 struct osigsetmask_args { 1415 int mask; 1416 }; 1417 #endif 1418 int 1419 osigsetmask(td, uap) 1420 struct thread *td; 1421 struct osigsetmask_args *uap; 1422 { 1423 sigset_t set, oset; 1424 1425 OSIG2SIG(uap->mask, set); 1426 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1427 SIG2OSIG(oset, td->td_retval[0]); 1428 return (0); 1429 } 1430 #endif /* COMPAT_43 */ 1431 1432 /* 1433 * Suspend calling thread until signal, providing mask to be set in the 1434 * meantime. 1435 */ 1436 #ifndef _SYS_SYSPROTO_H_ 1437 struct sigsuspend_args { 1438 const sigset_t *sigmask; 1439 }; 1440 #endif 1441 /* ARGSUSED */ 1442 int 1443 sigsuspend(td, uap) 1444 struct thread *td; 1445 struct sigsuspend_args *uap; 1446 { 1447 sigset_t mask; 1448 int error; 1449 1450 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1451 if (error) 1452 return (error); 1453 return (kern_sigsuspend(td, mask)); 1454 } 1455 1456 int 1457 kern_sigsuspend(struct thread *td, sigset_t mask) 1458 { 1459 struct proc *p = td->td_proc; 1460 int has_sig, sig; 1461 1462 /* 1463 * When returning from sigsuspend, we want 1464 * the old mask to be restored after the 1465 * signal handler has finished. Thus, we 1466 * save it here and mark the sigacts structure 1467 * to indicate this. 1468 */ 1469 PROC_LOCK(p); 1470 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1471 SIGPROCMASK_PROC_LOCKED); 1472 td->td_pflags |= TDP_OLDMASK; 1473 1474 /* 1475 * Process signals now. Otherwise, we can get spurious wakeup 1476 * due to signal entered process queue, but delivered to other 1477 * thread. But sigsuspend should return only on signal 1478 * delivery. 1479 */ 1480 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1481 for (has_sig = 0; !has_sig;) { 1482 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1483 0) == 0) 1484 /* void */; 1485 thread_suspend_check(0); 1486 mtx_lock(&p->p_sigacts->ps_mtx); 1487 while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0) 1488 has_sig += postsig(sig); 1489 mtx_unlock(&p->p_sigacts->ps_mtx); 1490 } 1491 PROC_UNLOCK(p); 1492 td->td_errno = EINTR; 1493 td->td_pflags |= TDP_NERRNO; 1494 return (EJUSTRETURN); 1495 } 1496 1497 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1498 /* 1499 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1500 * convention: libc stub passes mask, not pointer, to save a copyin. 1501 */ 1502 #ifndef _SYS_SYSPROTO_H_ 1503 struct osigsuspend_args { 1504 osigset_t mask; 1505 }; 1506 #endif 1507 /* ARGSUSED */ 1508 int 1509 osigsuspend(td, uap) 1510 struct thread *td; 1511 struct osigsuspend_args *uap; 1512 { 1513 sigset_t mask; 1514 1515 OSIG2SIG(uap->mask, mask); 1516 return (kern_sigsuspend(td, mask)); 1517 } 1518 #endif /* COMPAT_43 */ 1519 1520 #if defined(COMPAT_43) 1521 #ifndef _SYS_SYSPROTO_H_ 1522 struct osigstack_args { 1523 struct sigstack *nss; 1524 struct sigstack *oss; 1525 }; 1526 #endif 1527 /* ARGSUSED */ 1528 int 1529 osigstack(td, uap) 1530 struct thread *td; 1531 register struct osigstack_args *uap; 1532 { 1533 struct sigstack nss, oss; 1534 int error = 0; 1535 1536 if (uap->nss != NULL) { 1537 error = copyin(uap->nss, &nss, sizeof(nss)); 1538 if (error) 1539 return (error); 1540 } 1541 oss.ss_sp = td->td_sigstk.ss_sp; 1542 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1543 if (uap->nss != NULL) { 1544 td->td_sigstk.ss_sp = nss.ss_sp; 1545 td->td_sigstk.ss_size = 0; 1546 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1547 td->td_pflags |= TDP_ALTSTACK; 1548 } 1549 if (uap->oss != NULL) 1550 error = copyout(&oss, uap->oss, sizeof(oss)); 1551 1552 return (error); 1553 } 1554 #endif /* COMPAT_43 */ 1555 1556 #ifndef _SYS_SYSPROTO_H_ 1557 struct sigaltstack_args { 1558 stack_t *ss; 1559 stack_t *oss; 1560 }; 1561 #endif 1562 /* ARGSUSED */ 1563 int 1564 sigaltstack(td, uap) 1565 struct thread *td; 1566 register struct sigaltstack_args *uap; 1567 { 1568 stack_t ss, oss; 1569 int error; 1570 1571 if (uap->ss != NULL) { 1572 error = copyin(uap->ss, &ss, sizeof(ss)); 1573 if (error) 1574 return (error); 1575 } 1576 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1577 (uap->oss != NULL) ? &oss : NULL); 1578 if (error) 1579 return (error); 1580 if (uap->oss != NULL) 1581 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1582 return (error); 1583 } 1584 1585 int 1586 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1587 { 1588 struct proc *p = td->td_proc; 1589 int oonstack; 1590 1591 oonstack = sigonstack(cpu_getstack(td)); 1592 1593 if (oss != NULL) { 1594 *oss = td->td_sigstk; 1595 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1596 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1597 } 1598 1599 if (ss != NULL) { 1600 if (oonstack) 1601 return (EPERM); 1602 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1603 return (EINVAL); 1604 if (!(ss->ss_flags & SS_DISABLE)) { 1605 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1606 return (ENOMEM); 1607 1608 td->td_sigstk = *ss; 1609 td->td_pflags |= TDP_ALTSTACK; 1610 } else { 1611 td->td_pflags &= ~TDP_ALTSTACK; 1612 } 1613 } 1614 return (0); 1615 } 1616 1617 /* 1618 * Common code for kill process group/broadcast kill. 1619 * cp is calling process. 1620 */ 1621 static int 1622 killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1623 { 1624 struct proc *p; 1625 struct pgrp *pgrp; 1626 int err; 1627 int ret; 1628 1629 ret = ESRCH; 1630 if (all) { 1631 /* 1632 * broadcast 1633 */ 1634 sx_slock(&allproc_lock); 1635 FOREACH_PROC_IN_SYSTEM(p) { 1636 PROC_LOCK(p); 1637 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1638 p == td->td_proc || p->p_state == PRS_NEW) { 1639 PROC_UNLOCK(p); 1640 continue; 1641 } 1642 err = p_cansignal(td, p, sig); 1643 if (err == 0) { 1644 if (sig) 1645 pksignal(p, sig, ksi); 1646 ret = err; 1647 } 1648 else if (ret == ESRCH) 1649 ret = err; 1650 PROC_UNLOCK(p); 1651 } 1652 sx_sunlock(&allproc_lock); 1653 } else { 1654 sx_slock(&proctree_lock); 1655 if (pgid == 0) { 1656 /* 1657 * zero pgid means send to my process group. 1658 */ 1659 pgrp = td->td_proc->p_pgrp; 1660 PGRP_LOCK(pgrp); 1661 } else { 1662 pgrp = pgfind(pgid); 1663 if (pgrp == NULL) { 1664 sx_sunlock(&proctree_lock); 1665 return (ESRCH); 1666 } 1667 } 1668 sx_sunlock(&proctree_lock); 1669 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1670 PROC_LOCK(p); 1671 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1672 p->p_state == PRS_NEW ) { 1673 PROC_UNLOCK(p); 1674 continue; 1675 } 1676 err = p_cansignal(td, p, sig); 1677 if (err == 0) { 1678 if (sig) 1679 pksignal(p, sig, ksi); 1680 ret = err; 1681 } 1682 else if (ret == ESRCH) 1683 ret = err; 1684 PROC_UNLOCK(p); 1685 } 1686 PGRP_UNLOCK(pgrp); 1687 } 1688 return (ret); 1689 } 1690 1691 #ifndef _SYS_SYSPROTO_H_ 1692 struct kill_args { 1693 int pid; 1694 int signum; 1695 }; 1696 #endif 1697 /* ARGSUSED */ 1698 int 1699 kill(struct thread *td, struct kill_args *uap) 1700 { 1701 ksiginfo_t ksi; 1702 struct proc *p; 1703 int error; 1704 1705 AUDIT_ARG_SIGNUM(uap->signum); 1706 AUDIT_ARG_PID(uap->pid); 1707 if ((u_int)uap->signum > _SIG_MAXSIG) 1708 return (EINVAL); 1709 1710 ksiginfo_init(&ksi); 1711 ksi.ksi_signo = uap->signum; 1712 ksi.ksi_code = SI_USER; 1713 ksi.ksi_pid = td->td_proc->p_pid; 1714 ksi.ksi_uid = td->td_ucred->cr_ruid; 1715 1716 if (uap->pid > 0) { 1717 /* kill single process */ 1718 if ((p = pfind(uap->pid)) == NULL) { 1719 if ((p = zpfind(uap->pid)) == NULL) 1720 return (ESRCH); 1721 } 1722 AUDIT_ARG_PROCESS(p); 1723 error = p_cansignal(td, p, uap->signum); 1724 if (error == 0 && uap->signum) 1725 pksignal(p, uap->signum, &ksi); 1726 PROC_UNLOCK(p); 1727 return (error); 1728 } 1729 switch (uap->pid) { 1730 case -1: /* broadcast signal */ 1731 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1732 case 0: /* signal own process group */ 1733 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1734 default: /* negative explicit process group */ 1735 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1736 } 1737 /* NOTREACHED */ 1738 } 1739 1740 #if defined(COMPAT_43) 1741 #ifndef _SYS_SYSPROTO_H_ 1742 struct okillpg_args { 1743 int pgid; 1744 int signum; 1745 }; 1746 #endif 1747 /* ARGSUSED */ 1748 int 1749 okillpg(struct thread *td, struct okillpg_args *uap) 1750 { 1751 ksiginfo_t ksi; 1752 1753 AUDIT_ARG_SIGNUM(uap->signum); 1754 AUDIT_ARG_PID(uap->pgid); 1755 if ((u_int)uap->signum > _SIG_MAXSIG) 1756 return (EINVAL); 1757 1758 ksiginfo_init(&ksi); 1759 ksi.ksi_signo = uap->signum; 1760 ksi.ksi_code = SI_USER; 1761 ksi.ksi_pid = td->td_proc->p_pid; 1762 ksi.ksi_uid = td->td_ucred->cr_ruid; 1763 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1764 } 1765 #endif /* COMPAT_43 */ 1766 1767 #ifndef _SYS_SYSPROTO_H_ 1768 struct sigqueue_args { 1769 pid_t pid; 1770 int signum; 1771 /* union sigval */ void *value; 1772 }; 1773 #endif 1774 int 1775 sigqueue(struct thread *td, struct sigqueue_args *uap) 1776 { 1777 ksiginfo_t ksi; 1778 struct proc *p; 1779 int error; 1780 1781 if ((u_int)uap->signum > _SIG_MAXSIG) 1782 return (EINVAL); 1783 1784 /* 1785 * Specification says sigqueue can only send signal to 1786 * single process. 1787 */ 1788 if (uap->pid <= 0) 1789 return (EINVAL); 1790 1791 if ((p = pfind(uap->pid)) == NULL) { 1792 if ((p = zpfind(uap->pid)) == NULL) 1793 return (ESRCH); 1794 } 1795 error = p_cansignal(td, p, uap->signum); 1796 if (error == 0 && uap->signum != 0) { 1797 ksiginfo_init(&ksi); 1798 ksi.ksi_flags = KSI_SIGQ; 1799 ksi.ksi_signo = uap->signum; 1800 ksi.ksi_code = SI_QUEUE; 1801 ksi.ksi_pid = td->td_proc->p_pid; 1802 ksi.ksi_uid = td->td_ucred->cr_ruid; 1803 ksi.ksi_value.sival_ptr = uap->value; 1804 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1805 } 1806 PROC_UNLOCK(p); 1807 return (error); 1808 } 1809 1810 /* 1811 * Send a signal to a process group. 1812 */ 1813 void 1814 gsignal(int pgid, int sig, ksiginfo_t *ksi) 1815 { 1816 struct pgrp *pgrp; 1817 1818 if (pgid != 0) { 1819 sx_slock(&proctree_lock); 1820 pgrp = pgfind(pgid); 1821 sx_sunlock(&proctree_lock); 1822 if (pgrp != NULL) { 1823 pgsignal(pgrp, sig, 0, ksi); 1824 PGRP_UNLOCK(pgrp); 1825 } 1826 } 1827 } 1828 1829 /* 1830 * Send a signal to a process group. If checktty is 1, 1831 * limit to members which have a controlling terminal. 1832 */ 1833 void 1834 pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1835 { 1836 struct proc *p; 1837 1838 if (pgrp) { 1839 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1840 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1841 PROC_LOCK(p); 1842 if (p->p_state == PRS_NORMAL && 1843 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1844 pksignal(p, sig, ksi); 1845 PROC_UNLOCK(p); 1846 } 1847 } 1848 } 1849 1850 /* 1851 * Send a signal caused by a trap to the current thread. If it will be 1852 * caught immediately, deliver it with correct code. Otherwise, post it 1853 * normally. 1854 */ 1855 void 1856 trapsignal(struct thread *td, ksiginfo_t *ksi) 1857 { 1858 struct sigacts *ps; 1859 sigset_t mask; 1860 struct proc *p; 1861 int sig; 1862 int code; 1863 1864 p = td->td_proc; 1865 sig = ksi->ksi_signo; 1866 code = ksi->ksi_code; 1867 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1868 1869 PROC_LOCK(p); 1870 ps = p->p_sigacts; 1871 mtx_lock(&ps->ps_mtx); 1872 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1873 !SIGISMEMBER(td->td_sigmask, sig)) { 1874 td->td_ru.ru_nsignals++; 1875 #ifdef KTRACE 1876 if (KTRPOINT(curthread, KTR_PSIG)) 1877 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1878 &td->td_sigmask, code); 1879 #endif 1880 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1881 ksi, &td->td_sigmask); 1882 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1883 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1884 SIGADDSET(mask, sig); 1885 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1886 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1887 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1888 /* 1889 * See kern_sigaction() for origin of this code. 1890 */ 1891 SIGDELSET(ps->ps_sigcatch, sig); 1892 if (sig != SIGCONT && 1893 sigprop(sig) & SA_IGNORE) 1894 SIGADDSET(ps->ps_sigignore, sig); 1895 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1896 } 1897 mtx_unlock(&ps->ps_mtx); 1898 } else { 1899 /* 1900 * Avoid a possible infinite loop if the thread 1901 * masking the signal or process is ignoring the 1902 * signal. 1903 */ 1904 if (kern_forcesigexit && 1905 (SIGISMEMBER(td->td_sigmask, sig) || 1906 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1907 SIGDELSET(td->td_sigmask, sig); 1908 SIGDELSET(ps->ps_sigcatch, sig); 1909 SIGDELSET(ps->ps_sigignore, sig); 1910 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1911 } 1912 mtx_unlock(&ps->ps_mtx); 1913 p->p_code = code; /* XXX for core dump/debugger */ 1914 p->p_sig = sig; /* XXX to verify code */ 1915 tdsignal(p, td, sig, ksi); 1916 } 1917 PROC_UNLOCK(p); 1918 } 1919 1920 static struct thread * 1921 sigtd(struct proc *p, int sig, int prop) 1922 { 1923 struct thread *td, *signal_td; 1924 1925 PROC_LOCK_ASSERT(p, MA_OWNED); 1926 1927 /* 1928 * Check if current thread can handle the signal without 1929 * switching context to another thread. 1930 */ 1931 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1932 return (curthread); 1933 signal_td = NULL; 1934 FOREACH_THREAD_IN_PROC(p, td) { 1935 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1936 signal_td = td; 1937 break; 1938 } 1939 } 1940 if (signal_td == NULL) 1941 signal_td = FIRST_THREAD_IN_PROC(p); 1942 return (signal_td); 1943 } 1944 1945 /* 1946 * Send the signal to the process. If the signal has an action, the action 1947 * is usually performed by the target process rather than the caller; we add 1948 * the signal to the set of pending signals for the process. 1949 * 1950 * Exceptions: 1951 * o When a stop signal is sent to a sleeping process that takes the 1952 * default action, the process is stopped without awakening it. 1953 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1954 * regardless of the signal action (eg, blocked or ignored). 1955 * 1956 * Other ignored signals are discarded immediately. 1957 * 1958 * NB: This function may be entered from the debugger via the "kill" DDB 1959 * command. There is little that can be done to mitigate the possibly messy 1960 * side effects of this unwise possibility. 1961 */ 1962 void 1963 psignal(struct proc *p, int sig) 1964 { 1965 ksiginfo_t ksi; 1966 1967 ksiginfo_init(&ksi); 1968 ksi.ksi_signo = sig; 1969 ksi.ksi_code = SI_KERNEL; 1970 (void) tdsignal(p, NULL, sig, &ksi); 1971 } 1972 1973 void 1974 pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 1975 { 1976 1977 (void) tdsignal(p, NULL, sig, ksi); 1978 } 1979 1980 int 1981 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 1982 { 1983 struct thread *td = NULL; 1984 1985 PROC_LOCK_ASSERT(p, MA_OWNED); 1986 1987 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 1988 1989 /* 1990 * ksi_code and other fields should be set before 1991 * calling this function. 1992 */ 1993 ksi->ksi_signo = sigev->sigev_signo; 1994 ksi->ksi_value = sigev->sigev_value; 1995 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 1996 td = thread_find(p, sigev->sigev_notify_thread_id); 1997 if (td == NULL) 1998 return (ESRCH); 1999 } 2000 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 2001 } 2002 2003 void 2004 tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2005 { 2006 ksiginfo_t ksi_thunk; 2007 2008 /* 2009 * If ksi is NULL, use ksi_thunk and provide semantics 2010 * identical to tdsignal() in 9.0+. 2011 */ 2012 if (ksi == NULL) { 2013 ksi = &ksi_thunk; 2014 ksiginfo_init(ksi); 2015 ksi->ksi_signo = sig; 2016 ksi->ksi_code = SI_KERNEL; 2017 } 2018 (void) tdsignal(td->td_proc, td, sig, ksi); 2019 } 2020 2021 int 2022 tdsignal(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 PROC_LOCK_ASSERT(p, MA_OWNED); 2033 2034 if (!_SIG_VALID(sig)) 2035 panic("tdsignal(): invalid signal %d", sig); 2036 2037 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue")); 2038 2039 /* 2040 * IEEE Std 1003.1-2001: return success when killing a zombie. 2041 */ 2042 if (p->p_state == PRS_ZOMBIE) { 2043 if (ksi && (ksi->ksi_flags & KSI_INS)) 2044 ksiginfo_tryfree(ksi); 2045 return (ret); 2046 } 2047 2048 ps = p->p_sigacts; 2049 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2050 prop = sigprop(sig); 2051 2052 if (td == NULL) { 2053 td = sigtd(p, sig, prop); 2054 sigqueue = &p->p_sigqueue; 2055 } else { 2056 KASSERT(td->td_proc == p, ("invalid thread")); 2057 sigqueue = &td->td_sigqueue; 2058 } 2059 2060 SDT_PROBE(proc, kernel, , signal_send, td, p, sig, 0, 0 ); 2061 2062 /* 2063 * If the signal is being ignored, 2064 * then we forget about it immediately. 2065 * (Note: we don't set SIGCONT in ps_sigignore, 2066 * and if it is set to SIG_IGN, 2067 * action will be SIG_DFL here.) 2068 */ 2069 mtx_lock(&ps->ps_mtx); 2070 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2071 SDT_PROBE(proc, kernel, , signal_discard, td, p, sig, 0, 0 ); 2072 2073 mtx_unlock(&ps->ps_mtx); 2074 if (ksi && (ksi->ksi_flags & KSI_INS)) 2075 ksiginfo_tryfree(ksi); 2076 return (ret); 2077 } 2078 if (SIGISMEMBER(td->td_sigmask, sig)) 2079 action = SIG_HOLD; 2080 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2081 action = SIG_CATCH; 2082 else 2083 action = SIG_DFL; 2084 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2085 intrval = EINTR; 2086 else 2087 intrval = ERESTART; 2088 mtx_unlock(&ps->ps_mtx); 2089 2090 if (prop & SA_CONT) 2091 sigqueue_delete_stopmask_proc(p); 2092 else if (prop & SA_STOP) { 2093 /* 2094 * If sending a tty stop signal to a member of an orphaned 2095 * process group, discard the signal here if the action 2096 * is default; don't stop the process below if sleeping, 2097 * and don't clear any pending SIGCONT. 2098 */ 2099 if ((prop & SA_TTYSTOP) && 2100 (p->p_pgrp->pg_jobc == 0) && 2101 (action == SIG_DFL)) { 2102 if (ksi && (ksi->ksi_flags & KSI_INS)) 2103 ksiginfo_tryfree(ksi); 2104 return (ret); 2105 } 2106 sigqueue_delete_proc(p, SIGCONT); 2107 if (p->p_flag & P_CONTINUED) { 2108 p->p_flag &= ~P_CONTINUED; 2109 PROC_LOCK(p->p_pptr); 2110 sigqueue_take(p->p_ksi); 2111 PROC_UNLOCK(p->p_pptr); 2112 } 2113 } 2114 2115 ret = sigqueue_add(sigqueue, sig, ksi); 2116 if (ret != 0) 2117 return (ret); 2118 signotify(td); 2119 /* 2120 * Defer further processing for signals which are held, 2121 * except that stopped processes must be continued by SIGCONT. 2122 */ 2123 if (action == SIG_HOLD && 2124 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2125 return (ret); 2126 /* 2127 * SIGKILL: Remove procfs STOPEVENTs. 2128 */ 2129 if (sig == SIGKILL) { 2130 /* from procfs_ioctl.c: PIOCBIC */ 2131 p->p_stops = 0; 2132 /* from procfs_ioctl.c: PIOCCONT */ 2133 p->p_step = 0; 2134 wakeup(&p->p_step); 2135 } 2136 /* 2137 * Some signals have a process-wide effect and a per-thread 2138 * component. Most processing occurs when the process next 2139 * tries to cross the user boundary, however there are some 2140 * times when processing needs to be done immediatly, such as 2141 * waking up threads so that they can cross the user boundary. 2142 * We try do the per-process part here. 2143 */ 2144 if (P_SHOULDSTOP(p)) { 2145 KASSERT(!(p->p_flag & P_WEXIT), 2146 ("signal to stopped but exiting process")); 2147 if (sig == SIGKILL) { 2148 /* 2149 * If traced process is already stopped, 2150 * then no further action is necessary. 2151 */ 2152 if (p->p_flag & P_TRACED) 2153 goto out; 2154 /* 2155 * SIGKILL sets process running. 2156 * It will die elsewhere. 2157 * All threads must be restarted. 2158 */ 2159 p->p_flag &= ~P_STOPPED_SIG; 2160 goto runfast; 2161 } 2162 2163 if (prop & SA_CONT) { 2164 /* 2165 * If traced process is already stopped, 2166 * then no further action is necessary. 2167 */ 2168 if (p->p_flag & P_TRACED) 2169 goto out; 2170 /* 2171 * If SIGCONT is default (or ignored), we continue the 2172 * process but don't leave the signal in sigqueue as 2173 * it has no further action. If SIGCONT is held, we 2174 * continue the process and leave the signal in 2175 * sigqueue. If the process catches SIGCONT, let it 2176 * handle the signal itself. If it isn't waiting on 2177 * an event, it goes back to run state. 2178 * Otherwise, process goes back to sleep state. 2179 */ 2180 p->p_flag &= ~P_STOPPED_SIG; 2181 PROC_SLOCK(p); 2182 if (p->p_numthreads == p->p_suspcount) { 2183 PROC_SUNLOCK(p); 2184 p->p_flag |= P_CONTINUED; 2185 p->p_xstat = SIGCONT; 2186 PROC_LOCK(p->p_pptr); 2187 childproc_continued(p); 2188 PROC_UNLOCK(p->p_pptr); 2189 PROC_SLOCK(p); 2190 } 2191 if (action == SIG_DFL) { 2192 thread_unsuspend(p); 2193 PROC_SUNLOCK(p); 2194 sigqueue_delete(sigqueue, sig); 2195 goto out; 2196 } 2197 if (action == SIG_CATCH) { 2198 /* 2199 * The process wants to catch it so it needs 2200 * to run at least one thread, but which one? 2201 */ 2202 PROC_SUNLOCK(p); 2203 goto runfast; 2204 } 2205 /* 2206 * The signal is not ignored or caught. 2207 */ 2208 thread_unsuspend(p); 2209 PROC_SUNLOCK(p); 2210 goto out; 2211 } 2212 2213 if (prop & SA_STOP) { 2214 /* 2215 * If traced process is already stopped, 2216 * then no further action is necessary. 2217 */ 2218 if (p->p_flag & P_TRACED) 2219 goto out; 2220 /* 2221 * Already stopped, don't need to stop again 2222 * (If we did the shell could get confused). 2223 * Just make sure the signal STOP bit set. 2224 */ 2225 p->p_flag |= P_STOPPED_SIG; 2226 sigqueue_delete(sigqueue, sig); 2227 goto out; 2228 } 2229 2230 /* 2231 * All other kinds of signals: 2232 * If a thread is sleeping interruptibly, simulate a 2233 * wakeup so that when it is continued it will be made 2234 * runnable and can look at the signal. However, don't make 2235 * the PROCESS runnable, leave it stopped. 2236 * It may run a bit until it hits a thread_suspend_check(). 2237 */ 2238 wakeup_swapper = 0; 2239 PROC_SLOCK(p); 2240 thread_lock(td); 2241 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2242 wakeup_swapper = sleepq_abort(td, intrval); 2243 thread_unlock(td); 2244 PROC_SUNLOCK(p); 2245 if (wakeup_swapper) 2246 kick_proc0(); 2247 goto out; 2248 /* 2249 * Mutexes are short lived. Threads waiting on them will 2250 * hit thread_suspend_check() soon. 2251 */ 2252 } else if (p->p_state == PRS_NORMAL) { 2253 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2254 tdsigwakeup(td, sig, action, intrval); 2255 goto out; 2256 } 2257 2258 MPASS(action == SIG_DFL); 2259 2260 if (prop & SA_STOP) { 2261 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2262 goto out; 2263 p->p_flag |= P_STOPPED_SIG; 2264 p->p_xstat = sig; 2265 PROC_SLOCK(p); 2266 sig_suspend_threads(td, p, 1); 2267 if (p->p_numthreads == p->p_suspcount) { 2268 /* 2269 * only thread sending signal to another 2270 * process can reach here, if thread is sending 2271 * signal to its process, because thread does 2272 * not suspend itself here, p_numthreads 2273 * should never be equal to p_suspcount. 2274 */ 2275 thread_stopped(p); 2276 PROC_SUNLOCK(p); 2277 sigqueue_delete_proc(p, p->p_xstat); 2278 } else 2279 PROC_SUNLOCK(p); 2280 goto out; 2281 } 2282 } else { 2283 /* Not in "NORMAL" state. discard the signal. */ 2284 sigqueue_delete(sigqueue, sig); 2285 goto out; 2286 } 2287 2288 /* 2289 * The process is not stopped so we need to apply the signal to all the 2290 * running threads. 2291 */ 2292 runfast: 2293 tdsigwakeup(td, sig, action, intrval); 2294 PROC_SLOCK(p); 2295 thread_unsuspend(p); 2296 PROC_SUNLOCK(p); 2297 out: 2298 /* If we jump here, proc slock should not be owned. */ 2299 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2300 return (ret); 2301 } 2302 2303 /* 2304 * The force of a signal has been directed against a single 2305 * thread. We need to see what we can do about knocking it 2306 * out of any sleep it may be in etc. 2307 */ 2308 static void 2309 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2310 { 2311 struct proc *p = td->td_proc; 2312 register int prop; 2313 int wakeup_swapper; 2314 2315 wakeup_swapper = 0; 2316 PROC_LOCK_ASSERT(p, MA_OWNED); 2317 prop = sigprop(sig); 2318 2319 PROC_SLOCK(p); 2320 thread_lock(td); 2321 /* 2322 * Bring the priority of a thread up if we want it to get 2323 * killed in this lifetime. 2324 */ 2325 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2326 sched_prio(td, PUSER); 2327 if (TD_ON_SLEEPQ(td)) { 2328 /* 2329 * If thread is sleeping uninterruptibly 2330 * we can't interrupt the sleep... the signal will 2331 * be noticed when the process returns through 2332 * trap() or syscall(). 2333 */ 2334 if ((td->td_flags & TDF_SINTR) == 0) 2335 goto out; 2336 /* 2337 * If SIGCONT is default (or ignored) and process is 2338 * asleep, we are finished; the process should not 2339 * be awakened. 2340 */ 2341 if ((prop & SA_CONT) && action == SIG_DFL) { 2342 thread_unlock(td); 2343 PROC_SUNLOCK(p); 2344 sigqueue_delete(&p->p_sigqueue, sig); 2345 /* 2346 * It may be on either list in this state. 2347 * Remove from both for now. 2348 */ 2349 sigqueue_delete(&td->td_sigqueue, sig); 2350 return; 2351 } 2352 2353 /* 2354 * Give low priority threads a better chance to run. 2355 */ 2356 if (td->td_priority > PUSER) 2357 sched_prio(td, PUSER); 2358 2359 wakeup_swapper = sleepq_abort(td, intrval); 2360 } else { 2361 /* 2362 * Other states do nothing with the signal immediately, 2363 * other than kicking ourselves if we are running. 2364 * It will either never be noticed, or noticed very soon. 2365 */ 2366 #ifdef SMP 2367 if (TD_IS_RUNNING(td) && td != curthread) 2368 forward_signal(td); 2369 #endif 2370 } 2371 out: 2372 PROC_SUNLOCK(p); 2373 thread_unlock(td); 2374 if (wakeup_swapper) 2375 kick_proc0(); 2376 } 2377 2378 static void 2379 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2380 { 2381 struct thread *td2; 2382 int wakeup_swapper; 2383 2384 PROC_LOCK_ASSERT(p, MA_OWNED); 2385 PROC_SLOCK_ASSERT(p, MA_OWNED); 2386 2387 wakeup_swapper = 0; 2388 FOREACH_THREAD_IN_PROC(p, td2) { 2389 thread_lock(td2); 2390 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2391 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2392 (td2->td_flags & TDF_SINTR)) { 2393 if (td2->td_flags & TDF_SBDRY) { 2394 if (TD_IS_SUSPENDED(td2)) 2395 wakeup_swapper |= 2396 thread_unsuspend_one(td2); 2397 if (TD_ON_SLEEPQ(td2)) 2398 wakeup_swapper |= 2399 sleepq_abort(td2, ERESTART); 2400 } else if (!TD_IS_SUSPENDED(td2)) { 2401 thread_suspend_one(td2); 2402 } 2403 } else if (!TD_IS_SUSPENDED(td2)) { 2404 if (sending || td != td2) 2405 td2->td_flags |= TDF_ASTPENDING; 2406 #ifdef SMP 2407 if (TD_IS_RUNNING(td2) && td2 != td) 2408 forward_signal(td2); 2409 #endif 2410 } 2411 thread_unlock(td2); 2412 } 2413 if (wakeup_swapper) 2414 kick_proc0(); 2415 } 2416 2417 int 2418 ptracestop(struct thread *td, int sig) 2419 { 2420 struct proc *p = td->td_proc; 2421 2422 PROC_LOCK_ASSERT(p, MA_OWNED); 2423 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2424 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2425 &p->p_mtx.lock_object, "Stopping for traced signal"); 2426 2427 td->td_dbgflags |= TDB_XSIG; 2428 td->td_xsig = sig; 2429 PROC_SLOCK(p); 2430 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2431 if (p->p_flag & P_SINGLE_EXIT) { 2432 td->td_dbgflags &= ~TDB_XSIG; 2433 PROC_SUNLOCK(p); 2434 return (sig); 2435 } 2436 /* 2437 * Just make wait() to work, the last stopped thread 2438 * will win. 2439 */ 2440 p->p_xstat = sig; 2441 p->p_xthread = td; 2442 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2443 sig_suspend_threads(td, p, 0); 2444 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2445 td->td_dbgflags &= ~TDB_STOPATFORK; 2446 cv_broadcast(&p->p_dbgwait); 2447 } 2448 stopme: 2449 thread_suspend_switch(td); 2450 if (!(p->p_flag & P_TRACED)) { 2451 break; 2452 } 2453 if (td->td_dbgflags & TDB_SUSPEND) { 2454 if (p->p_flag & P_SINGLE_EXIT) 2455 break; 2456 goto stopme; 2457 } 2458 } 2459 PROC_SUNLOCK(p); 2460 return (td->td_xsig); 2461 } 2462 2463 static void 2464 reschedule_signals(struct proc *p, sigset_t block, int flags) 2465 { 2466 struct sigacts *ps; 2467 struct thread *td; 2468 int i; 2469 2470 PROC_LOCK_ASSERT(p, MA_OWNED); 2471 2472 ps = p->p_sigacts; 2473 for (i = 1; !SIGISEMPTY(block); i++) { 2474 if (!SIGISMEMBER(block, i)) 2475 continue; 2476 SIGDELSET(block, i); 2477 if (!SIGISMEMBER(p->p_siglist, i)) 2478 continue; 2479 2480 td = sigtd(p, i, 0); 2481 signotify(td); 2482 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2483 mtx_lock(&ps->ps_mtx); 2484 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, i)) 2485 tdsigwakeup(td, i, SIG_CATCH, 2486 (SIGISMEMBER(ps->ps_sigintr, i) ? EINTR : 2487 ERESTART)); 2488 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2489 mtx_unlock(&ps->ps_mtx); 2490 } 2491 } 2492 2493 void 2494 tdsigcleanup(struct thread *td) 2495 { 2496 struct proc *p; 2497 sigset_t unblocked; 2498 2499 p = td->td_proc; 2500 PROC_LOCK_ASSERT(p, MA_OWNED); 2501 2502 sigqueue_flush(&td->td_sigqueue); 2503 if (p->p_numthreads == 1) 2504 return; 2505 2506 /* 2507 * Since we cannot handle signals, notify signal post code 2508 * about this by filling the sigmask. 2509 * 2510 * Also, if needed, wake up thread(s) that do not block the 2511 * same signals as the exiting thread, since the thread might 2512 * have been selected for delivery and woken up. 2513 */ 2514 SIGFILLSET(unblocked); 2515 SIGSETNAND(unblocked, td->td_sigmask); 2516 SIGFILLSET(td->td_sigmask); 2517 reschedule_signals(p, unblocked, 0); 2518 2519 } 2520 2521 /* 2522 * If the current process has received a signal (should be caught or cause 2523 * termination, should interrupt current syscall), return the signal number. 2524 * Stop signals with default action are processed immediately, then cleared; 2525 * they aren't returned. This is checked after each entry to the system for 2526 * a syscall or trap (though this can usually be done without calling issignal 2527 * by checking the pending signal masks in cursig.) The normal call 2528 * sequence is 2529 * 2530 * while (sig = cursig(curthread)) 2531 * postsig(sig); 2532 */ 2533 static int 2534 issignal(struct thread *td, int stop_allowed) 2535 { 2536 struct proc *p; 2537 struct sigacts *ps; 2538 struct sigqueue *queue; 2539 sigset_t sigpending; 2540 int sig, prop, newsig; 2541 2542 p = td->td_proc; 2543 ps = p->p_sigacts; 2544 mtx_assert(&ps->ps_mtx, MA_OWNED); 2545 PROC_LOCK_ASSERT(p, MA_OWNED); 2546 for (;;) { 2547 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2548 2549 sigpending = td->td_sigqueue.sq_signals; 2550 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2551 SIGSETNAND(sigpending, td->td_sigmask); 2552 2553 if (p->p_flag & P_PPWAIT) 2554 SIG_STOPSIGMASK(sigpending); 2555 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2556 return (0); 2557 sig = sig_ffs(&sigpending); 2558 2559 if (p->p_stops & S_SIG) { 2560 mtx_unlock(&ps->ps_mtx); 2561 stopevent(p, S_SIG, sig); 2562 mtx_lock(&ps->ps_mtx); 2563 } 2564 2565 /* 2566 * We should see pending but ignored signals 2567 * only if P_TRACED was on when they were posted. 2568 */ 2569 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2570 sigqueue_delete(&td->td_sigqueue, sig); 2571 sigqueue_delete(&p->p_sigqueue, sig); 2572 continue; 2573 } 2574 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2575 /* 2576 * If traced, always stop. 2577 * Remove old signal from queue before the stop. 2578 * XXX shrug off debugger, it causes siginfo to 2579 * be thrown away. 2580 */ 2581 queue = &td->td_sigqueue; 2582 td->td_dbgksi.ksi_signo = 0; 2583 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2584 queue = &p->p_sigqueue; 2585 sigqueue_get(queue, sig, &td->td_dbgksi); 2586 } 2587 2588 mtx_unlock(&ps->ps_mtx); 2589 newsig = ptracestop(td, sig); 2590 mtx_lock(&ps->ps_mtx); 2591 2592 if (sig != newsig) { 2593 2594 /* 2595 * If parent wants us to take the signal, 2596 * then it will leave it in p->p_xstat; 2597 * otherwise we just look for signals again. 2598 */ 2599 if (newsig == 0) 2600 continue; 2601 sig = newsig; 2602 2603 /* 2604 * Put the new signal into td_sigqueue. If the 2605 * signal is being masked, look for other signals. 2606 */ 2607 sigqueue_add(queue, sig, NULL); 2608 if (SIGISMEMBER(td->td_sigmask, sig)) 2609 continue; 2610 signotify(td); 2611 } else { 2612 if (td->td_dbgksi.ksi_signo != 0) { 2613 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2614 if (sigqueue_add(&td->td_sigqueue, sig, 2615 &td->td_dbgksi) != 0) 2616 td->td_dbgksi.ksi_signo = 0; 2617 } 2618 if (td->td_dbgksi.ksi_signo == 0) 2619 sigqueue_add(&td->td_sigqueue, sig, 2620 NULL); 2621 } 2622 2623 /* 2624 * If the traced bit got turned off, go back up 2625 * to the top to rescan signals. This ensures 2626 * that p_sig* and p_sigact are consistent. 2627 */ 2628 if ((p->p_flag & P_TRACED) == 0) 2629 continue; 2630 } 2631 2632 prop = sigprop(sig); 2633 2634 /* 2635 * Decide whether the signal should be returned. 2636 * Return the signal's number, or fall through 2637 * to clear it from the pending mask. 2638 */ 2639 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2640 2641 case (intptr_t)SIG_DFL: 2642 /* 2643 * Don't take default actions on system processes. 2644 */ 2645 if (p->p_pid <= 1) { 2646 #ifdef DIAGNOSTIC 2647 /* 2648 * Are you sure you want to ignore SIGSEGV 2649 * in init? XXX 2650 */ 2651 printf("Process (pid %lu) got signal %d\n", 2652 (u_long)p->p_pid, sig); 2653 #endif 2654 break; /* == ignore */ 2655 } 2656 /* 2657 * If there is a pending stop signal to process 2658 * with default action, stop here, 2659 * then clear the signal. However, 2660 * if process is member of an orphaned 2661 * process group, ignore tty stop signals. 2662 */ 2663 if (prop & SA_STOP) { 2664 if (p->p_flag & (P_TRACED|P_WEXIT) || 2665 (p->p_pgrp->pg_jobc == 0 && 2666 prop & SA_TTYSTOP)) 2667 break; /* == ignore */ 2668 2669 /* Ignore, but do not drop the stop signal. */ 2670 if (stop_allowed != SIG_STOP_ALLOWED) 2671 return (sig); 2672 mtx_unlock(&ps->ps_mtx); 2673 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2674 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2675 p->p_flag |= P_STOPPED_SIG; 2676 p->p_xstat = sig; 2677 PROC_SLOCK(p); 2678 sig_suspend_threads(td, p, 0); 2679 thread_suspend_switch(td); 2680 PROC_SUNLOCK(p); 2681 mtx_lock(&ps->ps_mtx); 2682 break; 2683 } else if (prop & SA_IGNORE) { 2684 /* 2685 * Except for SIGCONT, shouldn't get here. 2686 * Default action is to ignore; drop it. 2687 */ 2688 break; /* == ignore */ 2689 } else 2690 return (sig); 2691 /*NOTREACHED*/ 2692 2693 case (intptr_t)SIG_IGN: 2694 /* 2695 * Masking above should prevent us ever trying 2696 * to take action on an ignored signal other 2697 * than SIGCONT, unless process is traced. 2698 */ 2699 if ((prop & SA_CONT) == 0 && 2700 (p->p_flag & P_TRACED) == 0) 2701 printf("issignal\n"); 2702 break; /* == ignore */ 2703 2704 default: 2705 /* 2706 * This signal has an action, let 2707 * postsig() process it. 2708 */ 2709 return (sig); 2710 } 2711 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2712 sigqueue_delete(&p->p_sigqueue, sig); 2713 } 2714 /* NOTREACHED */ 2715 } 2716 2717 void 2718 thread_stopped(struct proc *p) 2719 { 2720 int n; 2721 2722 PROC_LOCK_ASSERT(p, MA_OWNED); 2723 PROC_SLOCK_ASSERT(p, MA_OWNED); 2724 n = p->p_suspcount; 2725 if (p == curproc) 2726 n++; 2727 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2728 PROC_SUNLOCK(p); 2729 p->p_flag &= ~P_WAITED; 2730 PROC_LOCK(p->p_pptr); 2731 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2732 CLD_TRAPPED : CLD_STOPPED); 2733 PROC_UNLOCK(p->p_pptr); 2734 PROC_SLOCK(p); 2735 } 2736 } 2737 2738 /* 2739 * Take the action for the specified signal 2740 * from the current set of pending signals. 2741 */ 2742 int 2743 postsig(sig) 2744 register int sig; 2745 { 2746 struct thread *td = curthread; 2747 register struct proc *p = td->td_proc; 2748 struct sigacts *ps; 2749 sig_t action; 2750 ksiginfo_t ksi; 2751 sigset_t returnmask, mask; 2752 2753 KASSERT(sig != 0, ("postsig")); 2754 2755 PROC_LOCK_ASSERT(p, MA_OWNED); 2756 ps = p->p_sigacts; 2757 mtx_assert(&ps->ps_mtx, MA_OWNED); 2758 ksiginfo_init(&ksi); 2759 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2760 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2761 return (0); 2762 ksi.ksi_signo = sig; 2763 if (ksi.ksi_code == SI_TIMER) 2764 itimer_accept(p, ksi.ksi_timerid, &ksi); 2765 action = ps->ps_sigact[_SIG_IDX(sig)]; 2766 #ifdef KTRACE 2767 if (KTRPOINT(td, KTR_PSIG)) 2768 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2769 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2770 #endif 2771 if (p->p_stops & S_SIG) { 2772 mtx_unlock(&ps->ps_mtx); 2773 stopevent(p, S_SIG, sig); 2774 mtx_lock(&ps->ps_mtx); 2775 } 2776 2777 if (action == SIG_DFL) { 2778 /* 2779 * Default action, where the default is to kill 2780 * the process. (Other cases were ignored above.) 2781 */ 2782 mtx_unlock(&ps->ps_mtx); 2783 sigexit(td, sig); 2784 /* NOTREACHED */ 2785 } else { 2786 /* 2787 * If we get here, the signal must be caught. 2788 */ 2789 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2790 ("postsig action")); 2791 /* 2792 * Set the new mask value and also defer further 2793 * occurrences of this signal. 2794 * 2795 * Special case: user has done a sigsuspend. Here the 2796 * current mask is not of interest, but rather the 2797 * mask from before the sigsuspend is what we want 2798 * restored after the signal processing is completed. 2799 */ 2800 if (td->td_pflags & TDP_OLDMASK) { 2801 returnmask = td->td_oldsigmask; 2802 td->td_pflags &= ~TDP_OLDMASK; 2803 } else 2804 returnmask = td->td_sigmask; 2805 2806 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 2807 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2808 SIGADDSET(mask, sig); 2809 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 2810 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 2811 2812 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2813 /* 2814 * See kern_sigaction() for origin of this code. 2815 */ 2816 SIGDELSET(ps->ps_sigcatch, sig); 2817 if (sig != SIGCONT && 2818 sigprop(sig) & SA_IGNORE) 2819 SIGADDSET(ps->ps_sigignore, sig); 2820 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2821 } 2822 td->td_ru.ru_nsignals++; 2823 if (p->p_sig == sig) { 2824 p->p_code = 0; 2825 p->p_sig = 0; 2826 } 2827 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2828 } 2829 return (1); 2830 } 2831 2832 /* 2833 * Kill the current process for stated reason. 2834 */ 2835 void 2836 killproc(p, why) 2837 struct proc *p; 2838 char *why; 2839 { 2840 2841 PROC_LOCK_ASSERT(p, MA_OWNED); 2842 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2843 p, p->p_pid, p->p_comm); 2844 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2845 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2846 p->p_flag |= P_WKILLED; 2847 psignal(p, SIGKILL); 2848 } 2849 2850 /* 2851 * Force the current process to exit with the specified signal, dumping core 2852 * if appropriate. We bypass the normal tests for masked and caught signals, 2853 * allowing unrecoverable failures to terminate the process without changing 2854 * signal state. Mark the accounting record with the signal termination. 2855 * If dumping core, save the signal number for the debugger. Calls exit and 2856 * does not return. 2857 */ 2858 void 2859 sigexit(td, sig) 2860 struct thread *td; 2861 int sig; 2862 { 2863 struct proc *p = td->td_proc; 2864 2865 PROC_LOCK_ASSERT(p, MA_OWNED); 2866 p->p_acflag |= AXSIG; 2867 /* 2868 * We must be single-threading to generate a core dump. This 2869 * ensures that the registers in the core file are up-to-date. 2870 * Also, the ELF dump handler assumes that the thread list doesn't 2871 * change out from under it. 2872 * 2873 * XXX If another thread attempts to single-thread before us 2874 * (e.g. via fork()), we won't get a dump at all. 2875 */ 2876 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2877 p->p_sig = sig; 2878 /* 2879 * Log signals which would cause core dumps 2880 * (Log as LOG_INFO to appease those who don't want 2881 * these messages.) 2882 * XXX : Todo, as well as euid, write out ruid too 2883 * Note that coredump() drops proc lock. 2884 */ 2885 if (coredump(td) == 0) 2886 sig |= WCOREFLAG; 2887 if (kern_logsigexit) 2888 log(LOG_INFO, 2889 "pid %d (%s), uid %d: exited on signal %d%s\n", 2890 p->p_pid, p->p_comm, 2891 td->td_ucred ? td->td_ucred->cr_uid : -1, 2892 sig &~ WCOREFLAG, 2893 sig & WCOREFLAG ? " (core dumped)" : ""); 2894 } else 2895 PROC_UNLOCK(p); 2896 exit1(td, W_EXITCODE(0, sig)); 2897 /* NOTREACHED */ 2898 } 2899 2900 /* 2901 * Send queued SIGCHLD to parent when child process's state 2902 * is changed. 2903 */ 2904 static void 2905 sigparent(struct proc *p, int reason, int status) 2906 { 2907 PROC_LOCK_ASSERT(p, MA_OWNED); 2908 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2909 2910 if (p->p_ksi != NULL) { 2911 p->p_ksi->ksi_signo = SIGCHLD; 2912 p->p_ksi->ksi_code = reason; 2913 p->p_ksi->ksi_status = status; 2914 p->p_ksi->ksi_pid = p->p_pid; 2915 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2916 if (KSI_ONQ(p->p_ksi)) 2917 return; 2918 } 2919 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2920 } 2921 2922 static void 2923 childproc_jobstate(struct proc *p, int reason, int status) 2924 { 2925 struct sigacts *ps; 2926 2927 PROC_LOCK_ASSERT(p, MA_OWNED); 2928 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2929 2930 /* 2931 * Wake up parent sleeping in kern_wait(), also send 2932 * SIGCHLD to parent, but SIGCHLD does not guarantee 2933 * that parent will awake, because parent may masked 2934 * the signal. 2935 */ 2936 p->p_pptr->p_flag |= P_STATCHILD; 2937 wakeup(p->p_pptr); 2938 2939 ps = p->p_pptr->p_sigacts; 2940 mtx_lock(&ps->ps_mtx); 2941 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2942 mtx_unlock(&ps->ps_mtx); 2943 sigparent(p, reason, status); 2944 } else 2945 mtx_unlock(&ps->ps_mtx); 2946 } 2947 2948 void 2949 childproc_stopped(struct proc *p, int reason) 2950 { 2951 childproc_jobstate(p, reason, p->p_xstat); 2952 } 2953 2954 void 2955 childproc_continued(struct proc *p) 2956 { 2957 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2958 } 2959 2960 void 2961 childproc_exited(struct proc *p) 2962 { 2963 int reason; 2964 int status = p->p_xstat; /* convert to int */ 2965 2966 reason = CLD_EXITED; 2967 if (WCOREDUMP(status)) 2968 reason = CLD_DUMPED; 2969 else if (WIFSIGNALED(status)) 2970 reason = CLD_KILLED; 2971 /* 2972 * XXX avoid calling wakeup(p->p_pptr), the work is 2973 * done in exit1(). 2974 */ 2975 sigparent(p, reason, status); 2976 } 2977 2978 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2979 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2980 sizeof(corefilename), "process corefile name format string"); 2981 2982 /* 2983 * expand_name(name, uid, pid) 2984 * Expand the name described in corefilename, using name, uid, and pid. 2985 * corefilename is a printf-like string, with three format specifiers: 2986 * %N name of process ("name") 2987 * %P process id (pid) 2988 * %U user id (uid) 2989 * For example, "%N.core" is the default; they can be disabled completely 2990 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2991 * This is controlled by the sysctl variable kern.corefile (see above). 2992 */ 2993 static char * 2994 expand_name(name, uid, pid) 2995 const char *name; 2996 uid_t uid; 2997 pid_t pid; 2998 { 2999 struct sbuf sb; 3000 const char *format; 3001 char *temp; 3002 size_t i; 3003 3004 format = corefilename; 3005 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 3006 if (temp == NULL) 3007 return (NULL); 3008 (void)sbuf_new(&sb, temp, MAXPATHLEN, SBUF_FIXEDLEN); 3009 for (i = 0; format[i]; i++) { 3010 switch (format[i]) { 3011 case '%': /* Format character */ 3012 i++; 3013 switch (format[i]) { 3014 case '%': 3015 sbuf_putc(&sb, '%'); 3016 break; 3017 case 'N': /* process name */ 3018 sbuf_printf(&sb, "%s", name); 3019 break; 3020 case 'P': /* process id */ 3021 sbuf_printf(&sb, "%u", pid); 3022 break; 3023 case 'U': /* user id */ 3024 sbuf_printf(&sb, "%u", uid); 3025 break; 3026 default: 3027 log(LOG_ERR, 3028 "Unknown format character %c in " 3029 "corename `%s'\n", format[i], format); 3030 } 3031 break; 3032 default: 3033 sbuf_putc(&sb, format[i]); 3034 } 3035 } 3036 if (sbuf_overflowed(&sb)) { 3037 sbuf_delete(&sb); 3038 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3039 "long\n", (long)pid, name, (u_long)uid); 3040 free(temp, M_TEMP); 3041 return (NULL); 3042 } 3043 sbuf_finish(&sb); 3044 sbuf_delete(&sb); 3045 return (temp); 3046 } 3047 3048 /* 3049 * Dump a process' core. The main routine does some 3050 * policy checking, and creates the name of the coredump; 3051 * then it passes on a vnode and a size limit to the process-specific 3052 * coredump routine if there is one; if there _is not_ one, it returns 3053 * ENOSYS; otherwise it returns the error from the process-specific routine. 3054 */ 3055 3056 static int 3057 coredump(struct thread *td) 3058 { 3059 struct proc *p = td->td_proc; 3060 register struct vnode *vp; 3061 register struct ucred *cred = td->td_ucred; 3062 struct flock lf; 3063 struct nameidata nd; 3064 struct vattr vattr; 3065 int error, error1, flags, locked; 3066 struct mount *mp; 3067 char *name; /* name of corefile */ 3068 off_t limit; 3069 int vfslocked; 3070 3071 PROC_LOCK_ASSERT(p, MA_OWNED); 3072 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3073 _STOPEVENT(p, S_CORE, 0); 3074 3075 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3076 if (name == NULL) { 3077 PROC_UNLOCK(p); 3078 #ifdef AUDIT 3079 audit_proc_coredump(td, NULL, EINVAL); 3080 #endif 3081 return (EINVAL); 3082 } 3083 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3084 PROC_UNLOCK(p); 3085 #ifdef AUDIT 3086 audit_proc_coredump(td, name, EFAULT); 3087 #endif 3088 free(name, M_TEMP); 3089 return (EFAULT); 3090 } 3091 3092 /* 3093 * Note that the bulk of limit checking is done after 3094 * the corefile is created. The exception is if the limit 3095 * for corefiles is 0, in which case we don't bother 3096 * creating the corefile at all. This layout means that 3097 * a corefile is truncated instead of not being created, 3098 * if it is larger than the limit. 3099 */ 3100 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3101 PROC_UNLOCK(p); 3102 if (limit == 0) { 3103 #ifdef AUDIT 3104 audit_proc_coredump(td, name, EFBIG); 3105 #endif 3106 free(name, M_TEMP); 3107 return (EFBIG); 3108 } 3109 3110 restart: 3111 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3112 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3113 error = vn_open_cred(&nd, &flags, S_IRUSR | S_IWUSR, VN_OPEN_NOAUDIT, 3114 cred, NULL); 3115 if (error) { 3116 #ifdef AUDIT 3117 audit_proc_coredump(td, name, error); 3118 #endif 3119 free(name, M_TEMP); 3120 return (error); 3121 } 3122 vfslocked = NDHASGIANT(&nd); 3123 NDFREE(&nd, NDF_ONLY_PNBUF); 3124 vp = nd.ni_vp; 3125 3126 /* Don't dump to non-regular files or files with links. */ 3127 if (vp->v_type != VREG || 3128 VOP_GETATTR(vp, &vattr, cred) || vattr.va_nlink != 1) { 3129 VOP_UNLOCK(vp, 0); 3130 error = EFAULT; 3131 goto close; 3132 } 3133 3134 VOP_UNLOCK(vp, 0); 3135 lf.l_whence = SEEK_SET; 3136 lf.l_start = 0; 3137 lf.l_len = 0; 3138 lf.l_type = F_WRLCK; 3139 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3140 3141 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3142 lf.l_type = F_UNLCK; 3143 if (locked) 3144 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3145 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3146 goto out; 3147 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3148 goto out; 3149 VFS_UNLOCK_GIANT(vfslocked); 3150 goto restart; 3151 } 3152 3153 VATTR_NULL(&vattr); 3154 vattr.va_size = 0; 3155 if (set_core_nodump_flag) 3156 vattr.va_flags = UF_NODUMP; 3157 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3158 VOP_SETATTR(vp, &vattr, cred); 3159 VOP_UNLOCK(vp, 0); 3160 vn_finished_write(mp); 3161 PROC_LOCK(p); 3162 p->p_acflag |= ACORE; 3163 PROC_UNLOCK(p); 3164 3165 error = p->p_sysent->sv_coredump ? 3166 p->p_sysent->sv_coredump(td, vp, limit) : 3167 ENOSYS; 3168 3169 if (locked) { 3170 lf.l_type = F_UNLCK; 3171 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3172 } 3173 close: 3174 error1 = vn_close(vp, FWRITE, cred, td); 3175 if (error == 0) 3176 error = error1; 3177 out: 3178 #ifdef AUDIT 3179 audit_proc_coredump(td, name, error); 3180 #endif 3181 free(name, M_TEMP); 3182 VFS_UNLOCK_GIANT(vfslocked); 3183 return (error); 3184 } 3185 3186 /* 3187 * Nonexistent system call-- signal process (may want to handle it). Flag 3188 * error in case process won't see signal immediately (blocked or ignored). 3189 */ 3190 #ifndef _SYS_SYSPROTO_H_ 3191 struct nosys_args { 3192 int dummy; 3193 }; 3194 #endif 3195 /* ARGSUSED */ 3196 int 3197 nosys(td, args) 3198 struct thread *td; 3199 struct nosys_args *args; 3200 { 3201 struct proc *p = td->td_proc; 3202 3203 PROC_LOCK(p); 3204 psignal(p, SIGSYS); 3205 PROC_UNLOCK(p); 3206 return (ENOSYS); 3207 } 3208 3209 /* 3210 * Send a SIGIO or SIGURG signal to a process or process group using stored 3211 * credentials rather than those of the current process. 3212 */ 3213 void 3214 pgsigio(sigiop, sig, checkctty) 3215 struct sigio **sigiop; 3216 int sig, checkctty; 3217 { 3218 ksiginfo_t ksi; 3219 struct sigio *sigio; 3220 3221 ksiginfo_init(&ksi); 3222 ksi.ksi_signo = sig; 3223 ksi.ksi_code = SI_KERNEL; 3224 3225 SIGIO_LOCK(); 3226 sigio = *sigiop; 3227 if (sigio == NULL) { 3228 SIGIO_UNLOCK(); 3229 return; 3230 } 3231 if (sigio->sio_pgid > 0) { 3232 PROC_LOCK(sigio->sio_proc); 3233 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3234 psignal(sigio->sio_proc, sig); 3235 PROC_UNLOCK(sigio->sio_proc); 3236 } else if (sigio->sio_pgid < 0) { 3237 struct proc *p; 3238 3239 PGRP_LOCK(sigio->sio_pgrp); 3240 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3241 PROC_LOCK(p); 3242 if (p->p_state == PRS_NORMAL && 3243 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3244 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3245 psignal(p, sig); 3246 PROC_UNLOCK(p); 3247 } 3248 PGRP_UNLOCK(sigio->sio_pgrp); 3249 } 3250 SIGIO_UNLOCK(); 3251 } 3252 3253 static int 3254 filt_sigattach(struct knote *kn) 3255 { 3256 struct proc *p = curproc; 3257 3258 kn->kn_ptr.p_proc = p; 3259 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3260 3261 knlist_add(&p->p_klist, kn, 0); 3262 3263 return (0); 3264 } 3265 3266 static void 3267 filt_sigdetach(struct knote *kn) 3268 { 3269 struct proc *p = kn->kn_ptr.p_proc; 3270 3271 knlist_remove(&p->p_klist, kn, 0); 3272 } 3273 3274 /* 3275 * signal knotes are shared with proc knotes, so we apply a mask to 3276 * the hint in order to differentiate them from process hints. This 3277 * could be avoided by using a signal-specific knote list, but probably 3278 * isn't worth the trouble. 3279 */ 3280 static int 3281 filt_signal(struct knote *kn, long hint) 3282 { 3283 3284 if (hint & NOTE_SIGNAL) { 3285 hint &= ~NOTE_SIGNAL; 3286 3287 if (kn->kn_id == hint) 3288 kn->kn_data++; 3289 } 3290 return (kn->kn_data != 0); 3291 } 3292 3293 struct sigacts * 3294 sigacts_alloc(void) 3295 { 3296 struct sigacts *ps; 3297 3298 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3299 ps->ps_refcnt = 1; 3300 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3301 return (ps); 3302 } 3303 3304 void 3305 sigacts_free(struct sigacts *ps) 3306 { 3307 3308 mtx_lock(&ps->ps_mtx); 3309 ps->ps_refcnt--; 3310 if (ps->ps_refcnt == 0) { 3311 mtx_destroy(&ps->ps_mtx); 3312 free(ps, M_SUBPROC); 3313 } else 3314 mtx_unlock(&ps->ps_mtx); 3315 } 3316 3317 struct sigacts * 3318 sigacts_hold(struct sigacts *ps) 3319 { 3320 mtx_lock(&ps->ps_mtx); 3321 ps->ps_refcnt++; 3322 mtx_unlock(&ps->ps_mtx); 3323 return (ps); 3324 } 3325 3326 void 3327 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3328 { 3329 3330 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3331 mtx_lock(&src->ps_mtx); 3332 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3333 mtx_unlock(&src->ps_mtx); 3334 } 3335 3336 int 3337 sigacts_shared(struct sigacts *ps) 3338 { 3339 int shared; 3340 3341 mtx_lock(&ps->ps_mtx); 3342 shared = ps->ps_refcnt > 1; 3343 mtx_unlock(&ps->ps_mtx); 3344 return (shared); 3345 }
Cache object: 724f9cb7e763504461b1c967b65c3da6
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]