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("$FreeBSD$"); 39 40 #include "opt_compat.h" 41 #include "opt_ktrace.h" 42 43 #include <sys/param.h> 44 #include <sys/systm.h> 45 #include <sys/signalvar.h> 46 #include <sys/vnode.h> 47 #include <sys/acct.h> 48 #include <sys/condvar.h> 49 #include <sys/event.h> 50 #include <sys/fcntl.h> 51 #include <sys/kernel.h> 52 #include <sys/kse.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/pioctl.h> 61 #include <sys/resourcevar.h> 62 #include <sys/sched.h> 63 #include <sys/sleepqueue.h> 64 #include <sys/smp.h> 65 #include <sys/stat.h> 66 #include <sys/sx.h> 67 #include <sys/syscallsubr.h> 68 #include <sys/sysctl.h> 69 #include <sys/sysent.h> 70 #include <sys/syslog.h> 71 #include <sys/sysproto.h> 72 #include <sys/timers.h> 73 #include <sys/unistd.h> 74 #include <sys/wait.h> 75 #include <vm/vm.h> 76 #include <vm/vm_extern.h> 77 #include <vm/uma.h> 78 79 #include <posix4/posix4.h> 80 #include <machine/cpu.h> 81 82 #include <security/audit/audit.h> 83 84 #if defined (__alpha__) && !defined(COMPAT_43) 85 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 86 #endif 87 88 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 89 90 static int coredump(struct thread *); 91 static char *expand_name(const char *, uid_t, pid_t); 92 static int killpg1(struct thread *td, int sig, int pgid, int all); 93 static int issignal(struct thread *p); 94 static int sigprop(int sig); 95 static void tdsigwakeup(struct thread *, int, sig_t, int); 96 static void sig_suspend_threads(struct thread *, struct proc *, int); 97 static int filt_sigattach(struct knote *kn); 98 static void filt_sigdetach(struct knote *kn); 99 static int filt_signal(struct knote *kn, long hint); 100 static struct thread *sigtd(struct proc *p, int sig, int prop); 101 static int kern_sigtimedwait(struct thread *, sigset_t, 102 ksiginfo_t *, struct timespec *); 103 static int do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *); 104 static void sigqueue_start(void); 105 106 static uma_zone_t ksiginfo_zone = NULL; 107 struct filterops sig_filtops = 108 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 109 110 static int kern_logsigexit = 1; 111 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 112 &kern_logsigexit, 0, 113 "Log processes quitting on abnormal signals to syslog(3)"); 114 115 static int kern_forcesigexit = 1; 116 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 117 &kern_forcesigexit, 0, "Force trap signal to be handled"); 118 119 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 120 121 static int max_pending_per_proc = 128; 122 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 123 &max_pending_per_proc, 0, "Max pending signals per proc"); 124 125 static int preallocate_siginfo = 1024; 126 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 127 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 128 &preallocate_siginfo, 0, "Preallocated signal memory size"); 129 130 static int signal_overflow = 0; 131 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 132 &signal_overflow, 0, "Number of signals overflew"); 133 134 static int signal_alloc_fail = 0; 135 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 136 &signal_alloc_fail, 0, "signals failed to be allocated"); 137 138 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 139 140 /* 141 * Policy -- Can ucred cr1 send SIGIO to process cr2? 142 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 143 * in the right situations. 144 */ 145 #define CANSIGIO(cr1, cr2) \ 146 ((cr1)->cr_uid == 0 || \ 147 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 148 (cr1)->cr_uid == (cr2)->cr_ruid || \ 149 (cr1)->cr_ruid == (cr2)->cr_uid || \ 150 (cr1)->cr_uid == (cr2)->cr_uid) 151 152 int sugid_coredump; 153 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 154 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 155 156 static int do_coredump = 1; 157 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 158 &do_coredump, 0, "Enable/Disable coredumps"); 159 160 static int set_core_nodump_flag = 0; 161 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 162 0, "Enable setting the NODUMP flag on coredump files"); 163 164 /* 165 * Signal properties and actions. 166 * The array below categorizes the signals and their default actions 167 * according to the following properties: 168 */ 169 #define SA_KILL 0x01 /* terminates process by default */ 170 #define SA_CORE 0x02 /* ditto and coredumps */ 171 #define SA_STOP 0x04 /* suspend process */ 172 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 173 #define SA_IGNORE 0x10 /* ignore by default */ 174 #define SA_CONT 0x20 /* continue if suspended */ 175 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 176 #define SA_PROC 0x80 /* deliverable to any thread */ 177 178 static int sigproptbl[NSIG] = { 179 SA_KILL|SA_PROC, /* SIGHUP */ 180 SA_KILL|SA_PROC, /* SIGINT */ 181 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 182 SA_KILL|SA_CORE, /* SIGILL */ 183 SA_KILL|SA_CORE, /* SIGTRAP */ 184 SA_KILL|SA_CORE, /* SIGABRT */ 185 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 186 SA_KILL|SA_CORE, /* SIGFPE */ 187 SA_KILL|SA_PROC, /* SIGKILL */ 188 SA_KILL|SA_CORE, /* SIGBUS */ 189 SA_KILL|SA_CORE, /* SIGSEGV */ 190 SA_KILL|SA_CORE, /* SIGSYS */ 191 SA_KILL|SA_PROC, /* SIGPIPE */ 192 SA_KILL|SA_PROC, /* SIGALRM */ 193 SA_KILL|SA_PROC, /* SIGTERM */ 194 SA_IGNORE|SA_PROC, /* SIGURG */ 195 SA_STOP|SA_PROC, /* SIGSTOP */ 196 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 197 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 198 SA_IGNORE|SA_PROC, /* SIGCHLD */ 199 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 200 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 201 SA_IGNORE|SA_PROC, /* SIGIO */ 202 SA_KILL, /* SIGXCPU */ 203 SA_KILL, /* SIGXFSZ */ 204 SA_KILL|SA_PROC, /* SIGVTALRM */ 205 SA_KILL|SA_PROC, /* SIGPROF */ 206 SA_IGNORE|SA_PROC, /* SIGWINCH */ 207 SA_IGNORE|SA_PROC, /* SIGINFO */ 208 SA_KILL|SA_PROC, /* SIGUSR1 */ 209 SA_KILL|SA_PROC, /* SIGUSR2 */ 210 }; 211 212 static void 213 sigqueue_start(void) 214 { 215 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 216 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 217 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 218 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 219 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 220 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 221 } 222 223 ksiginfo_t * 224 ksiginfo_alloc(int wait) 225 { 226 int flags; 227 228 flags = M_ZERO; 229 if (! wait) 230 flags |= M_NOWAIT; 231 if (ksiginfo_zone != NULL) 232 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 233 return (NULL); 234 } 235 236 void 237 ksiginfo_free(ksiginfo_t *ksi) 238 { 239 uma_zfree(ksiginfo_zone, ksi); 240 } 241 242 static __inline int 243 ksiginfo_tryfree(ksiginfo_t *ksi) 244 { 245 if (!(ksi->ksi_flags & KSI_EXT)) { 246 uma_zfree(ksiginfo_zone, ksi); 247 return (1); 248 } 249 return (0); 250 } 251 252 void 253 sigqueue_init(sigqueue_t *list, struct proc *p) 254 { 255 SIGEMPTYSET(list->sq_signals); 256 SIGEMPTYSET(list->sq_kill); 257 TAILQ_INIT(&list->sq_list); 258 list->sq_proc = p; 259 list->sq_flags = SQ_INIT; 260 } 261 262 /* 263 * Get a signal's ksiginfo. 264 * Return: 265 * 0 - signal not found 266 * others - signal number 267 */ 268 int 269 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 270 { 271 struct proc *p = sq->sq_proc; 272 struct ksiginfo *ksi, *next; 273 int count = 0; 274 275 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 276 277 if (!SIGISMEMBER(sq->sq_signals, signo)) 278 return (0); 279 280 if (SIGISMEMBER(sq->sq_kill, signo)) { 281 count++; 282 SIGDELSET(sq->sq_kill, signo); 283 } 284 285 for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { 286 next = TAILQ_NEXT(ksi, ksi_link); 287 if (ksi->ksi_signo == signo) { 288 if (count == 0) { 289 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 290 ksi->ksi_sigq = NULL; 291 ksiginfo_copy(ksi, si); 292 if (ksiginfo_tryfree(ksi) && p != NULL) 293 p->p_pendingcnt--; 294 } 295 count++; 296 } 297 } 298 299 if (count <= 1) 300 SIGDELSET(sq->sq_signals, signo); 301 si->ksi_signo = signo; 302 return (signo); 303 } 304 305 void 306 sigqueue_take(ksiginfo_t *ksi) 307 { 308 struct ksiginfo *kp; 309 struct proc *p; 310 sigqueue_t *sq; 311 312 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 313 return; 314 315 p = sq->sq_proc; 316 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 317 ksi->ksi_sigq = NULL; 318 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 319 p->p_pendingcnt--; 320 321 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 322 kp = TAILQ_NEXT(kp, ksi_link)) { 323 if (kp->ksi_signo == ksi->ksi_signo) 324 break; 325 } 326 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 327 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 328 } 329 330 int 331 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 332 { 333 struct proc *p = sq->sq_proc; 334 struct ksiginfo *ksi; 335 int ret = 0; 336 337 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 338 339 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 340 SIGADDSET(sq->sq_kill, signo); 341 goto out_set_bit; 342 } 343 344 /* directly insert the ksi, don't copy it */ 345 if (si->ksi_flags & KSI_INS) { 346 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 347 si->ksi_sigq = sq; 348 goto out_set_bit; 349 } 350 351 if (__predict_false(ksiginfo_zone == NULL)) { 352 SIGADDSET(sq->sq_kill, signo); 353 goto out_set_bit; 354 } 355 356 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 357 signal_overflow++; 358 ret = EAGAIN; 359 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 360 signal_alloc_fail++; 361 ret = EAGAIN; 362 } else { 363 if (p != NULL) 364 p->p_pendingcnt++; 365 ksiginfo_copy(si, ksi); 366 ksi->ksi_signo = signo; 367 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 368 ksi->ksi_sigq = sq; 369 } 370 371 if ((si->ksi_flags & KSI_TRAP) != 0) { 372 if (ret != 0) 373 SIGADDSET(sq->sq_kill, signo); 374 ret = 0; 375 goto out_set_bit; 376 } 377 378 if (ret != 0) 379 return (ret); 380 381 out_set_bit: 382 SIGADDSET(sq->sq_signals, signo); 383 return (ret); 384 } 385 386 void 387 sigqueue_flush(sigqueue_t *sq) 388 { 389 struct proc *p = sq->sq_proc; 390 ksiginfo_t *ksi; 391 392 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 393 394 if (p != NULL) 395 PROC_LOCK_ASSERT(p, MA_OWNED); 396 397 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 398 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 399 ksi->ksi_sigq = NULL; 400 if (ksiginfo_tryfree(ksi) && p != NULL) 401 p->p_pendingcnt--; 402 } 403 404 SIGEMPTYSET(sq->sq_signals); 405 SIGEMPTYSET(sq->sq_kill); 406 } 407 408 void 409 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 410 { 411 ksiginfo_t *ksi; 412 413 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 414 415 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 416 SIGADDSET(*set, ksi->ksi_signo); 417 SIGSETOR(*set, sq->sq_kill); 418 } 419 420 void 421 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 422 { 423 sigset_t tmp, set; 424 struct proc *p1, *p2; 425 ksiginfo_t *ksi, *next; 426 427 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 428 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 429 /* 430 * make a copy, this allows setp to point to src or dst 431 * sq_signals without trouble. 432 */ 433 set = *setp; 434 p1 = src->sq_proc; 435 p2 = dst->sq_proc; 436 /* Move siginfo to target list */ 437 for (ksi = TAILQ_FIRST(&src->sq_list); ksi != NULL; ksi = next) { 438 next = TAILQ_NEXT(ksi, ksi_link); 439 if (SIGISMEMBER(set, ksi->ksi_signo)) { 440 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 441 if (p1 != NULL) 442 p1->p_pendingcnt--; 443 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 444 ksi->ksi_sigq = dst; 445 if (p2 != NULL) 446 p2->p_pendingcnt++; 447 } 448 } 449 450 /* Move pending bits to target list */ 451 tmp = src->sq_kill; 452 SIGSETAND(tmp, set); 453 SIGSETOR(dst->sq_kill, tmp); 454 SIGSETNAND(src->sq_kill, tmp); 455 456 tmp = src->sq_signals; 457 SIGSETAND(tmp, set); 458 SIGSETOR(dst->sq_signals, tmp); 459 SIGSETNAND(src->sq_signals, tmp); 460 461 /* Finally, rescan src queue and set pending bits for it */ 462 sigqueue_collect_set(src, &src->sq_signals); 463 } 464 465 void 466 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 467 { 468 sigset_t set; 469 470 SIGEMPTYSET(set); 471 SIGADDSET(set, signo); 472 sigqueue_move_set(src, dst, &set); 473 } 474 475 void 476 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 477 { 478 struct proc *p = sq->sq_proc; 479 ksiginfo_t *ksi, *next; 480 481 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 482 483 /* Remove siginfo queue */ 484 for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { 485 next = TAILQ_NEXT(ksi, ksi_link); 486 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 487 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 488 ksi->ksi_sigq = NULL; 489 if (ksiginfo_tryfree(ksi) && p != NULL) 490 p->p_pendingcnt--; 491 } 492 } 493 SIGSETNAND(sq->sq_kill, *set); 494 SIGSETNAND(sq->sq_signals, *set); 495 /* Finally, rescan queue and set pending bits for it */ 496 sigqueue_collect_set(sq, &sq->sq_signals); 497 } 498 499 void 500 sigqueue_delete(sigqueue_t *sq, int signo) 501 { 502 sigset_t set; 503 504 SIGEMPTYSET(set); 505 SIGADDSET(set, signo); 506 sigqueue_delete_set(sq, &set); 507 } 508 509 /* Remove a set of signals for a process */ 510 void 511 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 512 { 513 sigqueue_t worklist; 514 struct thread *td0; 515 516 PROC_LOCK_ASSERT(p, MA_OWNED); 517 518 sigqueue_init(&worklist, NULL); 519 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 520 521 mtx_lock_spin(&sched_lock); 522 FOREACH_THREAD_IN_PROC(p, td0) 523 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 524 mtx_unlock_spin(&sched_lock); 525 526 sigqueue_flush(&worklist); 527 } 528 529 void 530 sigqueue_delete_proc(struct proc *p, int signo) 531 { 532 sigset_t set; 533 534 SIGEMPTYSET(set); 535 SIGADDSET(set, signo); 536 sigqueue_delete_set_proc(p, &set); 537 } 538 539 void 540 sigqueue_delete_stopmask_proc(struct proc *p) 541 { 542 sigset_t set; 543 544 SIGEMPTYSET(set); 545 SIGADDSET(set, SIGSTOP); 546 SIGADDSET(set, SIGTSTP); 547 SIGADDSET(set, SIGTTIN); 548 SIGADDSET(set, SIGTTOU); 549 sigqueue_delete_set_proc(p, &set); 550 } 551 552 /* 553 * Determine signal that should be delivered to process p, the current 554 * process, 0 if none. If there is a pending stop signal with default 555 * action, the process stops in issignal(). 556 * 557 * MP SAFE. 558 */ 559 int 560 cursig(struct thread *td) 561 { 562 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 563 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 564 mtx_assert(&sched_lock, MA_NOTOWNED); 565 return (SIGPENDING(td) ? issignal(td) : 0); 566 } 567 568 /* 569 * Arrange for ast() to handle unmasked pending signals on return to user 570 * mode. This must be called whenever a signal is added to td_sigqueue or 571 * unmasked in td_sigmask. 572 */ 573 void 574 signotify(struct thread *td) 575 { 576 struct proc *p; 577 sigset_t set, saved; 578 579 p = td->td_proc; 580 581 PROC_LOCK_ASSERT(p, MA_OWNED); 582 583 /* 584 * If our mask changed we may have to move signal that were 585 * previously masked by all threads to our sigqueue. 586 */ 587 set = p->p_sigqueue.sq_signals; 588 if (p->p_flag & P_SA) 589 saved = p->p_sigqueue.sq_signals; 590 SIGSETNAND(set, td->td_sigmask); 591 if (! SIGISEMPTY(set)) 592 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set); 593 if (SIGPENDING(td)) { 594 mtx_lock_spin(&sched_lock); 595 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 596 mtx_unlock_spin(&sched_lock); 597 } 598 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 599 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 600 /* pending set changed */ 601 p->p_flag |= P_SIGEVENT; 602 wakeup(&p->p_siglist); 603 } 604 } 605 } 606 607 int 608 sigonstack(size_t sp) 609 { 610 struct thread *td = curthread; 611 612 return ((td->td_pflags & TDP_ALTSTACK) ? 613 #if defined(COMPAT_43) 614 ((td->td_sigstk.ss_size == 0) ? 615 (td->td_sigstk.ss_flags & SS_ONSTACK) : 616 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 617 #else 618 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 619 #endif 620 : 0); 621 } 622 623 static __inline int 624 sigprop(int sig) 625 { 626 627 if (sig > 0 && sig < NSIG) 628 return (sigproptbl[_SIG_IDX(sig)]); 629 return (0); 630 } 631 632 int 633 sig_ffs(sigset_t *set) 634 { 635 int i; 636 637 for (i = 0; i < _SIG_WORDS; i++) 638 if (set->__bits[i]) 639 return (ffs(set->__bits[i]) + (i * 32)); 640 return (0); 641 } 642 643 /* 644 * kern_sigaction 645 * sigaction 646 * freebsd4_sigaction 647 * osigaction 648 * 649 * MPSAFE 650 */ 651 int 652 kern_sigaction(td, sig, act, oact, flags) 653 struct thread *td; 654 register int sig; 655 struct sigaction *act, *oact; 656 int flags; 657 { 658 struct sigacts *ps; 659 struct proc *p = td->td_proc; 660 661 if (!_SIG_VALID(sig)) 662 return (EINVAL); 663 664 PROC_LOCK(p); 665 ps = p->p_sigacts; 666 mtx_lock(&ps->ps_mtx); 667 if (oact) { 668 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 669 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 670 oact->sa_flags = 0; 671 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 672 oact->sa_flags |= SA_ONSTACK; 673 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 674 oact->sa_flags |= SA_RESTART; 675 if (SIGISMEMBER(ps->ps_sigreset, sig)) 676 oact->sa_flags |= SA_RESETHAND; 677 if (SIGISMEMBER(ps->ps_signodefer, sig)) 678 oact->sa_flags |= SA_NODEFER; 679 if (SIGISMEMBER(ps->ps_siginfo, sig)) 680 oact->sa_flags |= SA_SIGINFO; 681 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 682 oact->sa_flags |= SA_NOCLDSTOP; 683 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 684 oact->sa_flags |= SA_NOCLDWAIT; 685 } 686 if (act) { 687 if ((sig == SIGKILL || sig == SIGSTOP) && 688 act->sa_handler != SIG_DFL) { 689 mtx_unlock(&ps->ps_mtx); 690 PROC_UNLOCK(p); 691 return (EINVAL); 692 } 693 694 /* 695 * Change setting atomically. 696 */ 697 698 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 699 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 700 if (act->sa_flags & SA_SIGINFO) { 701 ps->ps_sigact[_SIG_IDX(sig)] = 702 (__sighandler_t *)act->sa_sigaction; 703 SIGADDSET(ps->ps_siginfo, sig); 704 } else { 705 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 706 SIGDELSET(ps->ps_siginfo, sig); 707 } 708 if (!(act->sa_flags & SA_RESTART)) 709 SIGADDSET(ps->ps_sigintr, sig); 710 else 711 SIGDELSET(ps->ps_sigintr, sig); 712 if (act->sa_flags & SA_ONSTACK) 713 SIGADDSET(ps->ps_sigonstack, sig); 714 else 715 SIGDELSET(ps->ps_sigonstack, sig); 716 if (act->sa_flags & SA_RESETHAND) 717 SIGADDSET(ps->ps_sigreset, sig); 718 else 719 SIGDELSET(ps->ps_sigreset, sig); 720 if (act->sa_flags & SA_NODEFER) 721 SIGADDSET(ps->ps_signodefer, sig); 722 else 723 SIGDELSET(ps->ps_signodefer, sig); 724 if (sig == SIGCHLD) { 725 if (act->sa_flags & SA_NOCLDSTOP) 726 ps->ps_flag |= PS_NOCLDSTOP; 727 else 728 ps->ps_flag &= ~PS_NOCLDSTOP; 729 if (act->sa_flags & SA_NOCLDWAIT) { 730 /* 731 * Paranoia: since SA_NOCLDWAIT is implemented 732 * by reparenting the dying child to PID 1 (and 733 * trust it to reap the zombie), PID 1 itself 734 * is forbidden to set SA_NOCLDWAIT. 735 */ 736 if (p->p_pid == 1) 737 ps->ps_flag &= ~PS_NOCLDWAIT; 738 else 739 ps->ps_flag |= PS_NOCLDWAIT; 740 } else 741 ps->ps_flag &= ~PS_NOCLDWAIT; 742 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 743 ps->ps_flag |= PS_CLDSIGIGN; 744 else 745 ps->ps_flag &= ~PS_CLDSIGIGN; 746 } 747 /* 748 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 749 * and for signals set to SIG_DFL where the default is to 750 * ignore. However, don't put SIGCONT in ps_sigignore, as we 751 * have to restart the process. 752 */ 753 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 754 (sigprop(sig) & SA_IGNORE && 755 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 756 if ((p->p_flag & P_SA) && 757 SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) { 758 p->p_flag |= P_SIGEVENT; 759 wakeup(&p->p_siglist); 760 } 761 /* never to be seen again */ 762 sigqueue_delete_proc(p, sig); 763 if (sig != SIGCONT) 764 /* easier in psignal */ 765 SIGADDSET(ps->ps_sigignore, sig); 766 SIGDELSET(ps->ps_sigcatch, sig); 767 } else { 768 SIGDELSET(ps->ps_sigignore, sig); 769 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 770 SIGDELSET(ps->ps_sigcatch, sig); 771 else 772 SIGADDSET(ps->ps_sigcatch, sig); 773 } 774 #ifdef COMPAT_FREEBSD4 775 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 776 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 777 (flags & KSA_FREEBSD4) == 0) 778 SIGDELSET(ps->ps_freebsd4, sig); 779 else 780 SIGADDSET(ps->ps_freebsd4, sig); 781 #endif 782 #ifdef COMPAT_43 783 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 784 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 785 (flags & KSA_OSIGSET) == 0) 786 SIGDELSET(ps->ps_osigset, sig); 787 else 788 SIGADDSET(ps->ps_osigset, sig); 789 #endif 790 } 791 mtx_unlock(&ps->ps_mtx); 792 PROC_UNLOCK(p); 793 return (0); 794 } 795 796 #ifndef _SYS_SYSPROTO_H_ 797 struct sigaction_args { 798 int sig; 799 struct sigaction *act; 800 struct sigaction *oact; 801 }; 802 #endif 803 /* 804 * MPSAFE 805 */ 806 int 807 sigaction(td, uap) 808 struct thread *td; 809 register struct sigaction_args *uap; 810 { 811 struct sigaction act, oact; 812 register struct sigaction *actp, *oactp; 813 int error; 814 815 actp = (uap->act != NULL) ? &act : NULL; 816 oactp = (uap->oact != NULL) ? &oact : NULL; 817 if (actp) { 818 error = copyin(uap->act, actp, sizeof(act)); 819 if (error) 820 return (error); 821 } 822 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 823 if (oactp && !error) 824 error = copyout(oactp, uap->oact, sizeof(oact)); 825 return (error); 826 } 827 828 #ifdef COMPAT_FREEBSD4 829 #ifndef _SYS_SYSPROTO_H_ 830 struct freebsd4_sigaction_args { 831 int sig; 832 struct sigaction *act; 833 struct sigaction *oact; 834 }; 835 #endif 836 /* 837 * MPSAFE 838 */ 839 int 840 freebsd4_sigaction(td, uap) 841 struct thread *td; 842 register struct freebsd4_sigaction_args *uap; 843 { 844 struct sigaction act, oact; 845 register struct sigaction *actp, *oactp; 846 int error; 847 848 849 actp = (uap->act != NULL) ? &act : NULL; 850 oactp = (uap->oact != NULL) ? &oact : NULL; 851 if (actp) { 852 error = copyin(uap->act, actp, sizeof(act)); 853 if (error) 854 return (error); 855 } 856 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 857 if (oactp && !error) 858 error = copyout(oactp, uap->oact, sizeof(oact)); 859 return (error); 860 } 861 #endif /* COMAPT_FREEBSD4 */ 862 863 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 864 #ifndef _SYS_SYSPROTO_H_ 865 struct osigaction_args { 866 int signum; 867 struct osigaction *nsa; 868 struct osigaction *osa; 869 }; 870 #endif 871 /* 872 * MPSAFE 873 */ 874 int 875 osigaction(td, uap) 876 struct thread *td; 877 register struct osigaction_args *uap; 878 { 879 struct osigaction sa; 880 struct sigaction nsa, osa; 881 register struct sigaction *nsap, *osap; 882 int error; 883 884 if (uap->signum <= 0 || uap->signum >= ONSIG) 885 return (EINVAL); 886 887 nsap = (uap->nsa != NULL) ? &nsa : NULL; 888 osap = (uap->osa != NULL) ? &osa : NULL; 889 890 if (nsap) { 891 error = copyin(uap->nsa, &sa, sizeof(sa)); 892 if (error) 893 return (error); 894 nsap->sa_handler = sa.sa_handler; 895 nsap->sa_flags = sa.sa_flags; 896 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 897 } 898 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 899 if (osap && !error) { 900 sa.sa_handler = osap->sa_handler; 901 sa.sa_flags = osap->sa_flags; 902 SIG2OSIG(osap->sa_mask, sa.sa_mask); 903 error = copyout(&sa, uap->osa, sizeof(sa)); 904 } 905 return (error); 906 } 907 908 #if !defined(__i386__) && !defined(__alpha__) 909 /* Avoid replicating the same stub everywhere */ 910 int 911 osigreturn(td, uap) 912 struct thread *td; 913 struct osigreturn_args *uap; 914 { 915 916 return (nosys(td, (struct nosys_args *)uap)); 917 } 918 #endif 919 #endif /* COMPAT_43 */ 920 921 /* 922 * Initialize signal state for process 0; 923 * set to ignore signals that are ignored by default. 924 */ 925 void 926 siginit(p) 927 struct proc *p; 928 { 929 register int i; 930 struct sigacts *ps; 931 932 PROC_LOCK(p); 933 ps = p->p_sigacts; 934 mtx_lock(&ps->ps_mtx); 935 for (i = 1; i <= NSIG; i++) 936 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 937 SIGADDSET(ps->ps_sigignore, i); 938 mtx_unlock(&ps->ps_mtx); 939 PROC_UNLOCK(p); 940 } 941 942 /* 943 * Reset signals for an exec of the specified process. 944 */ 945 void 946 execsigs(struct proc *p) 947 { 948 struct sigacts *ps; 949 int sig; 950 struct thread *td; 951 952 /* 953 * Reset caught signals. Held signals remain held 954 * through td_sigmask (unless they were caught, 955 * and are now ignored by default). 956 */ 957 PROC_LOCK_ASSERT(p, MA_OWNED); 958 td = FIRST_THREAD_IN_PROC(p); 959 ps = p->p_sigacts; 960 mtx_lock(&ps->ps_mtx); 961 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 962 sig = sig_ffs(&ps->ps_sigcatch); 963 SIGDELSET(ps->ps_sigcatch, sig); 964 if (sigprop(sig) & SA_IGNORE) { 965 if (sig != SIGCONT) 966 SIGADDSET(ps->ps_sigignore, sig); 967 sigqueue_delete_proc(p, sig); 968 } 969 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 970 } 971 /* 972 * Reset stack state to the user stack. 973 * Clear set of signals caught on the signal stack. 974 */ 975 td->td_sigstk.ss_flags = SS_DISABLE; 976 td->td_sigstk.ss_size = 0; 977 td->td_sigstk.ss_sp = 0; 978 td->td_pflags &= ~TDP_ALTSTACK; 979 /* 980 * Reset no zombies if child dies flag as Solaris does. 981 */ 982 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 983 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 984 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 985 mtx_unlock(&ps->ps_mtx); 986 } 987 988 /* 989 * kern_sigprocmask() 990 * 991 * Manipulate signal mask. 992 */ 993 int 994 kern_sigprocmask(td, how, set, oset, old) 995 struct thread *td; 996 int how; 997 sigset_t *set, *oset; 998 int old; 999 { 1000 int error; 1001 1002 PROC_LOCK(td->td_proc); 1003 if (oset != NULL) 1004 *oset = td->td_sigmask; 1005 1006 error = 0; 1007 if (set != NULL) { 1008 switch (how) { 1009 case SIG_BLOCK: 1010 SIG_CANTMASK(*set); 1011 SIGSETOR(td->td_sigmask, *set); 1012 break; 1013 case SIG_UNBLOCK: 1014 SIGSETNAND(td->td_sigmask, *set); 1015 signotify(td); 1016 break; 1017 case SIG_SETMASK: 1018 SIG_CANTMASK(*set); 1019 if (old) 1020 SIGSETLO(td->td_sigmask, *set); 1021 else 1022 td->td_sigmask = *set; 1023 signotify(td); 1024 break; 1025 default: 1026 error = EINVAL; 1027 break; 1028 } 1029 } 1030 PROC_UNLOCK(td->td_proc); 1031 return (error); 1032 } 1033 1034 /* 1035 * sigprocmask() - MP SAFE 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 /* 1070 * osigprocmask() - MP SAFE 1071 */ 1072 #ifndef _SYS_SYSPROTO_H_ 1073 struct osigprocmask_args { 1074 int how; 1075 osigset_t mask; 1076 }; 1077 #endif 1078 int 1079 osigprocmask(td, uap) 1080 register struct thread *td; 1081 struct osigprocmask_args *uap; 1082 { 1083 sigset_t set, oset; 1084 int error; 1085 1086 OSIG2SIG(uap->mask, set); 1087 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1088 SIG2OSIG(oset, td->td_retval[0]); 1089 return (error); 1090 } 1091 #endif /* COMPAT_43 */ 1092 1093 /* 1094 * MPSAFE 1095 */ 1096 int 1097 sigwait(struct thread *td, struct sigwait_args *uap) 1098 { 1099 ksiginfo_t ksi; 1100 sigset_t set; 1101 int error; 1102 1103 error = copyin(uap->set, &set, sizeof(set)); 1104 if (error) { 1105 td->td_retval[0] = error; 1106 return (0); 1107 } 1108 1109 error = kern_sigtimedwait(td, set, &ksi, NULL); 1110 if (error) { 1111 if (error == ERESTART) 1112 return (error); 1113 td->td_retval[0] = error; 1114 return (0); 1115 } 1116 1117 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1118 td->td_retval[0] = error; 1119 return (0); 1120 } 1121 /* 1122 * MPSAFE 1123 */ 1124 int 1125 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1126 { 1127 struct timespec ts; 1128 struct timespec *timeout; 1129 sigset_t set; 1130 ksiginfo_t ksi; 1131 int error; 1132 1133 if (uap->timeout) { 1134 error = copyin(uap->timeout, &ts, sizeof(ts)); 1135 if (error) 1136 return (error); 1137 1138 timeout = &ts; 1139 } else 1140 timeout = NULL; 1141 1142 error = copyin(uap->set, &set, sizeof(set)); 1143 if (error) 1144 return (error); 1145 1146 error = kern_sigtimedwait(td, set, &ksi, timeout); 1147 if (error) 1148 return (error); 1149 1150 if (uap->info) 1151 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1152 1153 if (error == 0) 1154 td->td_retval[0] = ksi.ksi_signo; 1155 return (error); 1156 } 1157 1158 /* 1159 * MPSAFE 1160 */ 1161 int 1162 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1163 { 1164 ksiginfo_t ksi; 1165 sigset_t set; 1166 int error; 1167 1168 error = copyin(uap->set, &set, sizeof(set)); 1169 if (error) 1170 return (error); 1171 1172 error = kern_sigtimedwait(td, set, &ksi, NULL); 1173 if (error) 1174 return (error); 1175 1176 if (uap->info) 1177 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1178 1179 if (error == 0) 1180 td->td_retval[0] = ksi.ksi_signo; 1181 return (error); 1182 } 1183 1184 static int 1185 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1186 struct timespec *timeout) 1187 { 1188 struct sigacts *ps; 1189 sigset_t savedmask; 1190 struct proc *p; 1191 int error, sig, hz, i, timevalid = 0; 1192 struct timespec rts, ets, ts; 1193 struct timeval tv; 1194 1195 p = td->td_proc; 1196 error = 0; 1197 sig = 0; 1198 SIG_CANTMASK(waitset); 1199 1200 PROC_LOCK(p); 1201 ps = p->p_sigacts; 1202 savedmask = td->td_sigmask; 1203 if (timeout) { 1204 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1205 timevalid = 1; 1206 getnanouptime(&rts); 1207 ets = rts; 1208 timespecadd(&ets, timeout); 1209 } 1210 } 1211 1212 restart: 1213 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1214 if (!SIGISMEMBER(waitset, i)) 1215 continue; 1216 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1217 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1218 if (p->p_flag & P_SA) { 1219 p->p_flag |= P_SIGEVENT; 1220 wakeup(&p->p_siglist); 1221 } 1222 sigqueue_move(&p->p_sigqueue, 1223 &td->td_sigqueue, i); 1224 } else 1225 continue; 1226 } 1227 1228 SIGFILLSET(td->td_sigmask); 1229 SIG_CANTMASK(td->td_sigmask); 1230 SIGDELSET(td->td_sigmask, i); 1231 mtx_lock(&ps->ps_mtx); 1232 sig = cursig(td); 1233 mtx_unlock(&ps->ps_mtx); 1234 if (sig) 1235 goto out; 1236 else { 1237 /* 1238 * Because cursig() may have stopped current thread, 1239 * after it is resumed, things may have already been 1240 * changed, it should rescan any pending signals. 1241 */ 1242 goto restart; 1243 } 1244 } 1245 1246 if (error) 1247 goto out; 1248 1249 /* 1250 * POSIX says this must be checked after looking for pending 1251 * signals. 1252 */ 1253 if (timeout) { 1254 if (!timevalid) { 1255 error = EINVAL; 1256 goto out; 1257 } 1258 getnanouptime(&rts); 1259 if (timespeccmp(&rts, &ets, >=)) { 1260 error = EAGAIN; 1261 goto out; 1262 } 1263 ts = ets; 1264 timespecsub(&ts, &rts); 1265 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1266 hz = tvtohz(&tv); 1267 } else 1268 hz = 0; 1269 1270 td->td_sigmask = savedmask; 1271 SIGSETNAND(td->td_sigmask, waitset); 1272 signotify(td); 1273 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1274 if (timeout) { 1275 if (error == ERESTART) { 1276 /* timeout can not be restarted. */ 1277 error = EINTR; 1278 } else if (error == EAGAIN) { 1279 /* will calculate timeout by ourself. */ 1280 error = 0; 1281 } 1282 } 1283 goto restart; 1284 1285 out: 1286 td->td_sigmask = savedmask; 1287 signotify(td); 1288 if (sig) { 1289 ksiginfo_init(ksi); 1290 sigqueue_get(&td->td_sigqueue, sig, ksi); 1291 ksi->ksi_signo = sig; 1292 if (ksi->ksi_code == SI_TIMER) 1293 itimer_accept(p, ksi->ksi_timerid, ksi); 1294 error = 0; 1295 1296 #ifdef KTRACE 1297 if (KTRPOINT(td, KTR_PSIG)) { 1298 sig_t action; 1299 1300 mtx_lock(&ps->ps_mtx); 1301 action = ps->ps_sigact[_SIG_IDX(sig)]; 1302 mtx_unlock(&ps->ps_mtx); 1303 ktrpsig(sig, action, &td->td_sigmask, 0); 1304 } 1305 #endif 1306 _STOPEVENT(p, S_SIG, sig); 1307 1308 if (sig == SIGKILL) { 1309 p->p_code = ksi->ksi_code; 1310 p->p_sig = sig; 1311 sigexit(td, sig); 1312 } 1313 } 1314 PROC_UNLOCK(p); 1315 return (error); 1316 } 1317 1318 #ifndef _SYS_SYSPROTO_H_ 1319 struct sigpending_args { 1320 sigset_t *set; 1321 }; 1322 #endif 1323 /* 1324 * MPSAFE 1325 */ 1326 int 1327 sigpending(td, uap) 1328 struct thread *td; 1329 struct sigpending_args *uap; 1330 { 1331 struct proc *p = td->td_proc; 1332 sigset_t pending; 1333 1334 PROC_LOCK(p); 1335 pending = p->p_sigqueue.sq_signals; 1336 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1337 PROC_UNLOCK(p); 1338 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1339 } 1340 1341 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1342 #ifndef _SYS_SYSPROTO_H_ 1343 struct osigpending_args { 1344 int dummy; 1345 }; 1346 #endif 1347 /* 1348 * MPSAFE 1349 */ 1350 int 1351 osigpending(td, uap) 1352 struct thread *td; 1353 struct osigpending_args *uap; 1354 { 1355 struct proc *p = td->td_proc; 1356 sigset_t pending; 1357 1358 PROC_LOCK(p); 1359 pending = p->p_sigqueue.sq_signals; 1360 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1361 PROC_UNLOCK(p); 1362 SIG2OSIG(pending, td->td_retval[0]); 1363 return (0); 1364 } 1365 #endif /* COMPAT_43 */ 1366 1367 #if defined(COMPAT_43) 1368 /* 1369 * Generalized interface signal handler, 4.3-compatible. 1370 */ 1371 #ifndef _SYS_SYSPROTO_H_ 1372 struct osigvec_args { 1373 int signum; 1374 struct sigvec *nsv; 1375 struct sigvec *osv; 1376 }; 1377 #endif 1378 /* 1379 * MPSAFE 1380 */ 1381 /* ARGSUSED */ 1382 int 1383 osigvec(td, uap) 1384 struct thread *td; 1385 register struct osigvec_args *uap; 1386 { 1387 struct sigvec vec; 1388 struct sigaction nsa, osa; 1389 register struct sigaction *nsap, *osap; 1390 int error; 1391 1392 if (uap->signum <= 0 || uap->signum >= ONSIG) 1393 return (EINVAL); 1394 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1395 osap = (uap->osv != NULL) ? &osa : NULL; 1396 if (nsap) { 1397 error = copyin(uap->nsv, &vec, sizeof(vec)); 1398 if (error) 1399 return (error); 1400 nsap->sa_handler = vec.sv_handler; 1401 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1402 nsap->sa_flags = vec.sv_flags; 1403 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1404 } 1405 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1406 if (osap && !error) { 1407 vec.sv_handler = osap->sa_handler; 1408 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1409 vec.sv_flags = osap->sa_flags; 1410 vec.sv_flags &= ~SA_NOCLDWAIT; 1411 vec.sv_flags ^= SA_RESTART; 1412 error = copyout(&vec, uap->osv, sizeof(vec)); 1413 } 1414 return (error); 1415 } 1416 1417 #ifndef _SYS_SYSPROTO_H_ 1418 struct osigblock_args { 1419 int mask; 1420 }; 1421 #endif 1422 /* 1423 * MPSAFE 1424 */ 1425 int 1426 osigblock(td, uap) 1427 register struct thread *td; 1428 struct osigblock_args *uap; 1429 { 1430 struct proc *p = td->td_proc; 1431 sigset_t set; 1432 1433 OSIG2SIG(uap->mask, set); 1434 SIG_CANTMASK(set); 1435 PROC_LOCK(p); 1436 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1437 SIGSETOR(td->td_sigmask, set); 1438 PROC_UNLOCK(p); 1439 return (0); 1440 } 1441 1442 #ifndef _SYS_SYSPROTO_H_ 1443 struct osigsetmask_args { 1444 int mask; 1445 }; 1446 #endif 1447 /* 1448 * MPSAFE 1449 */ 1450 int 1451 osigsetmask(td, uap) 1452 struct thread *td; 1453 struct osigsetmask_args *uap; 1454 { 1455 struct proc *p = td->td_proc; 1456 sigset_t set; 1457 1458 OSIG2SIG(uap->mask, set); 1459 SIG_CANTMASK(set); 1460 PROC_LOCK(p); 1461 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1462 SIGSETLO(td->td_sigmask, set); 1463 signotify(td); 1464 PROC_UNLOCK(p); 1465 return (0); 1466 } 1467 #endif /* COMPAT_43 */ 1468 1469 /* 1470 * Suspend calling thread until signal, providing mask to be set 1471 * in the meantime. 1472 */ 1473 #ifndef _SYS_SYSPROTO_H_ 1474 struct sigsuspend_args { 1475 const sigset_t *sigmask; 1476 }; 1477 #endif 1478 /* 1479 * MPSAFE 1480 */ 1481 /* ARGSUSED */ 1482 int 1483 sigsuspend(td, uap) 1484 struct thread *td; 1485 struct sigsuspend_args *uap; 1486 { 1487 sigset_t mask; 1488 int error; 1489 1490 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1491 if (error) 1492 return (error); 1493 return (kern_sigsuspend(td, mask)); 1494 } 1495 1496 int 1497 kern_sigsuspend(struct thread *td, sigset_t mask) 1498 { 1499 struct proc *p = td->td_proc; 1500 1501 /* 1502 * When returning from sigsuspend, we want 1503 * the old mask to be restored after the 1504 * signal handler has finished. Thus, we 1505 * save it here and mark the sigacts structure 1506 * to indicate this. 1507 */ 1508 PROC_LOCK(p); 1509 td->td_oldsigmask = td->td_sigmask; 1510 td->td_pflags |= TDP_OLDMASK; 1511 SIG_CANTMASK(mask); 1512 td->td_sigmask = mask; 1513 signotify(td); 1514 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1515 /* void */; 1516 PROC_UNLOCK(p); 1517 /* always return EINTR rather than ERESTART... */ 1518 return (EINTR); 1519 } 1520 1521 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1522 /* 1523 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1524 * convention: libc stub passes mask, not pointer, to save a copyin. 1525 */ 1526 #ifndef _SYS_SYSPROTO_H_ 1527 struct osigsuspend_args { 1528 osigset_t mask; 1529 }; 1530 #endif 1531 /* 1532 * MPSAFE 1533 */ 1534 /* ARGSUSED */ 1535 int 1536 osigsuspend(td, uap) 1537 struct thread *td; 1538 struct osigsuspend_args *uap; 1539 { 1540 struct proc *p = td->td_proc; 1541 sigset_t mask; 1542 1543 PROC_LOCK(p); 1544 td->td_oldsigmask = td->td_sigmask; 1545 td->td_pflags |= TDP_OLDMASK; 1546 OSIG2SIG(uap->mask, mask); 1547 SIG_CANTMASK(mask); 1548 SIGSETLO(td->td_sigmask, mask); 1549 signotify(td); 1550 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1551 /* void */; 1552 PROC_UNLOCK(p); 1553 /* always return EINTR rather than ERESTART... */ 1554 return (EINTR); 1555 } 1556 #endif /* COMPAT_43 */ 1557 1558 #if defined(COMPAT_43) 1559 #ifndef _SYS_SYSPROTO_H_ 1560 struct osigstack_args { 1561 struct sigstack *nss; 1562 struct sigstack *oss; 1563 }; 1564 #endif 1565 /* 1566 * MPSAFE 1567 */ 1568 /* ARGSUSED */ 1569 int 1570 osigstack(td, uap) 1571 struct thread *td; 1572 register struct osigstack_args *uap; 1573 { 1574 struct sigstack nss, oss; 1575 int error = 0; 1576 1577 if (uap->nss != NULL) { 1578 error = copyin(uap->nss, &nss, sizeof(nss)); 1579 if (error) 1580 return (error); 1581 } 1582 oss.ss_sp = td->td_sigstk.ss_sp; 1583 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1584 if (uap->nss != NULL) { 1585 td->td_sigstk.ss_sp = nss.ss_sp; 1586 td->td_sigstk.ss_size = 0; 1587 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1588 td->td_pflags |= TDP_ALTSTACK; 1589 } 1590 if (uap->oss != NULL) 1591 error = copyout(&oss, uap->oss, sizeof(oss)); 1592 1593 return (error); 1594 } 1595 #endif /* COMPAT_43 */ 1596 1597 #ifndef _SYS_SYSPROTO_H_ 1598 struct sigaltstack_args { 1599 stack_t *ss; 1600 stack_t *oss; 1601 }; 1602 #endif 1603 /* 1604 * MPSAFE 1605 */ 1606 /* ARGSUSED */ 1607 int 1608 sigaltstack(td, uap) 1609 struct thread *td; 1610 register struct sigaltstack_args *uap; 1611 { 1612 stack_t ss, oss; 1613 int error; 1614 1615 if (uap->ss != NULL) { 1616 error = copyin(uap->ss, &ss, sizeof(ss)); 1617 if (error) 1618 return (error); 1619 } 1620 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1621 (uap->oss != NULL) ? &oss : NULL); 1622 if (error) 1623 return (error); 1624 if (uap->oss != NULL) 1625 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1626 return (error); 1627 } 1628 1629 int 1630 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1631 { 1632 struct proc *p = td->td_proc; 1633 int oonstack; 1634 1635 oonstack = sigonstack(cpu_getstack(td)); 1636 1637 if (oss != NULL) { 1638 *oss = td->td_sigstk; 1639 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1640 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1641 } 1642 1643 if (ss != NULL) { 1644 if (oonstack) 1645 return (EPERM); 1646 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1647 return (EINVAL); 1648 if (!(ss->ss_flags & SS_DISABLE)) { 1649 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1650 return (ENOMEM); 1651 1652 td->td_sigstk = *ss; 1653 td->td_pflags |= TDP_ALTSTACK; 1654 } else { 1655 td->td_pflags &= ~TDP_ALTSTACK; 1656 } 1657 } 1658 return (0); 1659 } 1660 1661 /* 1662 * Common code for kill process group/broadcast kill. 1663 * cp is calling process. 1664 */ 1665 static int 1666 killpg1(td, sig, pgid, all) 1667 register struct thread *td; 1668 int sig, pgid, all; 1669 { 1670 register struct proc *p; 1671 struct pgrp *pgrp; 1672 int nfound = 0; 1673 1674 if (all) { 1675 /* 1676 * broadcast 1677 */ 1678 sx_slock(&allproc_lock); 1679 LIST_FOREACH(p, &allproc, p_list) { 1680 PROC_LOCK(p); 1681 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1682 p == td->td_proc) { 1683 PROC_UNLOCK(p); 1684 continue; 1685 } 1686 if (p_cansignal(td, p, sig) == 0) { 1687 nfound++; 1688 if (sig) 1689 psignal(p, sig); 1690 } 1691 PROC_UNLOCK(p); 1692 } 1693 sx_sunlock(&allproc_lock); 1694 } else { 1695 sx_slock(&proctree_lock); 1696 if (pgid == 0) { 1697 /* 1698 * zero pgid means send to my process group. 1699 */ 1700 pgrp = td->td_proc->p_pgrp; 1701 PGRP_LOCK(pgrp); 1702 } else { 1703 pgrp = pgfind(pgid); 1704 if (pgrp == NULL) { 1705 sx_sunlock(&proctree_lock); 1706 return (ESRCH); 1707 } 1708 } 1709 sx_sunlock(&proctree_lock); 1710 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1711 PROC_LOCK(p); 1712 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1713 PROC_UNLOCK(p); 1714 continue; 1715 } 1716 if (p_cansignal(td, p, sig) == 0) { 1717 nfound++; 1718 if (sig) 1719 psignal(p, sig); 1720 } 1721 PROC_UNLOCK(p); 1722 } 1723 PGRP_UNLOCK(pgrp); 1724 } 1725 return (nfound ? 0 : ESRCH); 1726 } 1727 1728 #ifndef _SYS_SYSPROTO_H_ 1729 struct kill_args { 1730 int pid; 1731 int signum; 1732 }; 1733 #endif 1734 /* 1735 * MPSAFE 1736 */ 1737 /* ARGSUSED */ 1738 int 1739 kill(td, uap) 1740 register struct thread *td; 1741 register struct kill_args *uap; 1742 { 1743 register struct proc *p; 1744 int error; 1745 1746 AUDIT_ARG(signum, uap->signum); 1747 if ((u_int)uap->signum > _SIG_MAXSIG) 1748 return (EINVAL); 1749 1750 if (uap->pid > 0) { 1751 /* kill single process */ 1752 if ((p = pfind(uap->pid)) == NULL) { 1753 if ((p = zpfind(uap->pid)) == NULL) 1754 return (ESRCH); 1755 } 1756 AUDIT_ARG(process, p); 1757 error = p_cansignal(td, p, uap->signum); 1758 if (error == 0 && uap->signum) 1759 psignal(p, uap->signum); 1760 PROC_UNLOCK(p); 1761 return (error); 1762 } 1763 AUDIT_ARG(pid, uap->pid); 1764 switch (uap->pid) { 1765 case -1: /* broadcast signal */ 1766 return (killpg1(td, uap->signum, 0, 1)); 1767 case 0: /* signal own process group */ 1768 return (killpg1(td, uap->signum, 0, 0)); 1769 default: /* negative explicit process group */ 1770 return (killpg1(td, uap->signum, -uap->pid, 0)); 1771 } 1772 /* NOTREACHED */ 1773 } 1774 1775 #if defined(COMPAT_43) 1776 #ifndef _SYS_SYSPROTO_H_ 1777 struct okillpg_args { 1778 int pgid; 1779 int signum; 1780 }; 1781 #endif 1782 /* 1783 * MPSAFE 1784 */ 1785 /* ARGSUSED */ 1786 int 1787 okillpg(td, uap) 1788 struct thread *td; 1789 register struct okillpg_args *uap; 1790 { 1791 1792 AUDIT_ARG(signum, uap->signum); 1793 AUDIT_ARG(pid, uap->pgid); 1794 if ((u_int)uap->signum > _SIG_MAXSIG) 1795 return (EINVAL); 1796 1797 return (killpg1(td, uap->signum, uap->pgid, 0)); 1798 } 1799 #endif /* COMPAT_43 */ 1800 1801 #ifndef _SYS_SYSPROTO_H_ 1802 struct sigqueue_args { 1803 pid_t pid; 1804 int signum; 1805 /* union sigval */ void *value; 1806 }; 1807 #endif 1808 1809 int 1810 sigqueue(struct thread *td, struct sigqueue_args *uap) 1811 { 1812 ksiginfo_t ksi; 1813 struct proc *p; 1814 int error; 1815 1816 if ((u_int)uap->signum > _SIG_MAXSIG) 1817 return (EINVAL); 1818 1819 /* 1820 * Specification says sigqueue can only send signal to 1821 * single process. 1822 */ 1823 if (uap->pid <= 0) 1824 return (EINVAL); 1825 1826 if ((p = pfind(uap->pid)) == NULL) { 1827 if ((p = zpfind(uap->pid)) == NULL) 1828 return (ESRCH); 1829 } 1830 error = p_cansignal(td, p, uap->signum); 1831 if (error == 0 && uap->signum != 0) { 1832 ksiginfo_init(&ksi); 1833 ksi.ksi_signo = uap->signum; 1834 ksi.ksi_code = SI_QUEUE; 1835 ksi.ksi_pid = td->td_proc->p_pid; 1836 ksi.ksi_uid = td->td_ucred->cr_ruid; 1837 ksi.ksi_value.sival_ptr = uap->value; 1838 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1839 } 1840 PROC_UNLOCK(p); 1841 return (error); 1842 } 1843 1844 /* 1845 * Send a signal to a process group. 1846 */ 1847 void 1848 gsignal(pgid, sig) 1849 int pgid, sig; 1850 { 1851 struct pgrp *pgrp; 1852 1853 if (pgid != 0) { 1854 sx_slock(&proctree_lock); 1855 pgrp = pgfind(pgid); 1856 sx_sunlock(&proctree_lock); 1857 if (pgrp != NULL) { 1858 pgsignal(pgrp, sig, 0); 1859 PGRP_UNLOCK(pgrp); 1860 } 1861 } 1862 } 1863 1864 /* 1865 * Send a signal to a process group. If checktty is 1, 1866 * limit to members which have a controlling terminal. 1867 */ 1868 void 1869 pgsignal(pgrp, sig, checkctty) 1870 struct pgrp *pgrp; 1871 int sig, checkctty; 1872 { 1873 register struct proc *p; 1874 1875 if (pgrp) { 1876 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1877 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1878 PROC_LOCK(p); 1879 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1880 psignal(p, sig); 1881 PROC_UNLOCK(p); 1882 } 1883 } 1884 } 1885 1886 /* 1887 * Send a signal caused by a trap to the current thread. 1888 * If it will be caught immediately, deliver it with correct code. 1889 * Otherwise, post it normally. 1890 * 1891 * MPSAFE 1892 */ 1893 void 1894 trapsignal(struct thread *td, ksiginfo_t *ksi) 1895 { 1896 struct sigacts *ps; 1897 struct proc *p; 1898 int error; 1899 int sig; 1900 int code; 1901 1902 p = td->td_proc; 1903 sig = ksi->ksi_signo; 1904 code = ksi->ksi_code; 1905 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1906 1907 if (td->td_pflags & TDP_SA) { 1908 if (td->td_mailbox == NULL) 1909 thread_user_enter(td); 1910 PROC_LOCK(p); 1911 SIGDELSET(td->td_sigmask, sig); 1912 mtx_lock_spin(&sched_lock); 1913 /* 1914 * Force scheduling an upcall, so UTS has chance to 1915 * process the signal before thread runs again in 1916 * userland. 1917 */ 1918 if (td->td_upcall) 1919 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1920 mtx_unlock_spin(&sched_lock); 1921 } else { 1922 PROC_LOCK(p); 1923 } 1924 ps = p->p_sigacts; 1925 mtx_lock(&ps->ps_mtx); 1926 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1927 !SIGISMEMBER(td->td_sigmask, sig)) { 1928 p->p_stats->p_ru.ru_nsignals++; 1929 #ifdef KTRACE 1930 if (KTRPOINT(curthread, KTR_PSIG)) 1931 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1932 &td->td_sigmask, code); 1933 #endif 1934 if (!(td->td_pflags & TDP_SA)) 1935 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1936 ksi, &td->td_sigmask); 1937 else if (td->td_mailbox == NULL) { 1938 mtx_unlock(&ps->ps_mtx); 1939 /* UTS caused a sync signal */ 1940 p->p_code = code; /* XXX for core dump/debugger */ 1941 p->p_sig = sig; /* XXX to verify code */ 1942 sigexit(td, sig); 1943 } else { 1944 mtx_unlock(&ps->ps_mtx); 1945 SIGADDSET(td->td_sigmask, sig); 1946 PROC_UNLOCK(p); 1947 error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig, 1948 sizeof(siginfo_t)); 1949 PROC_LOCK(p); 1950 /* UTS memory corrupted */ 1951 if (error) 1952 sigexit(td, SIGSEGV); 1953 mtx_lock(&ps->ps_mtx); 1954 } 1955 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1956 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1957 SIGADDSET(td->td_sigmask, sig); 1958 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1959 /* 1960 * See kern_sigaction() for origin of this code. 1961 */ 1962 SIGDELSET(ps->ps_sigcatch, sig); 1963 if (sig != SIGCONT && 1964 sigprop(sig) & SA_IGNORE) 1965 SIGADDSET(ps->ps_sigignore, sig); 1966 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1967 } 1968 mtx_unlock(&ps->ps_mtx); 1969 } else { 1970 /* 1971 * Avoid a possible infinite loop if the thread 1972 * masking the signal or process is ignoring the 1973 * signal. 1974 */ 1975 if (kern_forcesigexit && 1976 (SIGISMEMBER(td->td_sigmask, sig) || 1977 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1978 SIGDELSET(td->td_sigmask, sig); 1979 SIGDELSET(ps->ps_sigcatch, sig); 1980 SIGDELSET(ps->ps_sigignore, sig); 1981 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1982 } 1983 mtx_unlock(&ps->ps_mtx); 1984 p->p_code = code; /* XXX for core dump/debugger */ 1985 p->p_sig = sig; /* XXX to verify code */ 1986 tdsignal(p, td, sig, ksi); 1987 } 1988 PROC_UNLOCK(p); 1989 } 1990 1991 static struct thread * 1992 sigtd(struct proc *p, int sig, int prop) 1993 { 1994 struct thread *td, *signal_td; 1995 1996 PROC_LOCK_ASSERT(p, MA_OWNED); 1997 1998 /* 1999 * Check if current thread can handle the signal without 2000 * switching conetxt to another thread. 2001 */ 2002 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2003 return (curthread); 2004 signal_td = NULL; 2005 mtx_lock_spin(&sched_lock); 2006 FOREACH_THREAD_IN_PROC(p, td) { 2007 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2008 signal_td = td; 2009 break; 2010 } 2011 } 2012 if (signal_td == NULL) 2013 signal_td = FIRST_THREAD_IN_PROC(p); 2014 mtx_unlock_spin(&sched_lock); 2015 return (signal_td); 2016 } 2017 2018 /* 2019 * Send the signal to the process. If the signal has an action, the action 2020 * is usually performed by the target process rather than the caller; we add 2021 * the signal to the set of pending signals for the process. 2022 * 2023 * Exceptions: 2024 * o When a stop signal is sent to a sleeping process that takes the 2025 * default action, the process is stopped without awakening it. 2026 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2027 * regardless of the signal action (eg, blocked or ignored). 2028 * 2029 * Other ignored signals are discarded immediately. 2030 * 2031 * MPSAFE 2032 */ 2033 void 2034 psignal(struct proc *p, int sig) 2035 { 2036 (void) tdsignal(p, NULL, sig, NULL); 2037 } 2038 2039 int 2040 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 2041 { 2042 struct thread *td = NULL; 2043 2044 PROC_LOCK_ASSERT(p, MA_OWNED); 2045 2046 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 2047 2048 /* 2049 * ksi_code and other fields should be set before 2050 * calling this function. 2051 */ 2052 ksi->ksi_signo = sigev->sigev_signo; 2053 ksi->ksi_value = sigev->sigev_value; 2054 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2055 td = thread_find(p, sigev->sigev_notify_thread_id); 2056 if (td == NULL) 2057 return (ESRCH); 2058 } 2059 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 2060 } 2061 2062 /* 2063 * MPSAFE 2064 */ 2065 int 2066 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2067 { 2068 sigset_t saved; 2069 int ret; 2070 2071 if (p->p_flag & P_SA) 2072 saved = p->p_sigqueue.sq_signals; 2073 ret = do_tdsignal(p, td, sig, ksi); 2074 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 2075 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 2076 /* pending set changed */ 2077 p->p_flag |= P_SIGEVENT; 2078 wakeup(&p->p_siglist); 2079 } 2080 } 2081 return (ret); 2082 } 2083 2084 static int 2085 do_tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2086 { 2087 sig_t action; 2088 sigqueue_t *sigqueue; 2089 int prop; 2090 struct sigacts *ps; 2091 int intrval; 2092 int ret = 0; 2093 2094 PROC_LOCK_ASSERT(p, MA_OWNED); 2095 2096 if (!_SIG_VALID(sig)) 2097 panic("do_tdsignal(): invalid signal"); 2098 2099 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue")); 2100 2101 /* 2102 * IEEE Std 1003.1-2001: return success when killing a zombie. 2103 */ 2104 if (p->p_state == PRS_ZOMBIE) { 2105 if (ksi && (ksi->ksi_flags & KSI_INS)) 2106 ksiginfo_tryfree(ksi); 2107 return (ret); 2108 } 2109 2110 ps = p->p_sigacts; 2111 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2112 prop = sigprop(sig); 2113 2114 /* 2115 * If the signal is blocked and not destined for this thread, then 2116 * assign it to the process so that we can find it later in the first 2117 * thread that unblocks it. Otherwise, assign it to this thread now. 2118 */ 2119 if (td == NULL) { 2120 td = sigtd(p, sig, prop); 2121 if (SIGISMEMBER(td->td_sigmask, sig)) 2122 sigqueue = &p->p_sigqueue; 2123 else 2124 sigqueue = &td->td_sigqueue; 2125 } else { 2126 KASSERT(td->td_proc == p, ("invalid thread")); 2127 sigqueue = &td->td_sigqueue; 2128 } 2129 2130 /* 2131 * If the signal is being ignored, 2132 * or process is exiting or thread is exiting, 2133 * then we forget about it immediately. 2134 * (Note: we don't set SIGCONT in ps_sigignore, 2135 * and if it is set to SIG_IGN, 2136 * action will be SIG_DFL here.) 2137 */ 2138 mtx_lock(&ps->ps_mtx); 2139 if (SIGISMEMBER(ps->ps_sigignore, sig) || 2140 (p->p_flag & P_WEXIT)) { 2141 mtx_unlock(&ps->ps_mtx); 2142 if (ksi && (ksi->ksi_flags & KSI_INS)) 2143 ksiginfo_tryfree(ksi); 2144 return (ret); 2145 } 2146 if (SIGISMEMBER(td->td_sigmask, sig)) 2147 action = SIG_HOLD; 2148 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2149 action = SIG_CATCH; 2150 else 2151 action = SIG_DFL; 2152 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2153 intrval = EINTR; 2154 else 2155 intrval = ERESTART; 2156 mtx_unlock(&ps->ps_mtx); 2157 2158 if (prop & SA_CONT) 2159 sigqueue_delete_stopmask_proc(p); 2160 else if (prop & SA_STOP) { 2161 /* 2162 * If sending a tty stop signal to a member of an orphaned 2163 * process group, discard the signal here if the action 2164 * is default; don't stop the process below if sleeping, 2165 * and don't clear any pending SIGCONT. 2166 */ 2167 if ((prop & SA_TTYSTOP) && 2168 (p->p_pgrp->pg_jobc == 0) && 2169 (action == SIG_DFL)) { 2170 if (ksi && (ksi->ksi_flags & KSI_INS)) 2171 ksiginfo_tryfree(ksi); 2172 return (ret); 2173 } 2174 sigqueue_delete_proc(p, SIGCONT); 2175 if (p->p_flag & P_CONTINUED) { 2176 p->p_flag &= ~P_CONTINUED; 2177 PROC_LOCK(p->p_pptr); 2178 sigqueue_take(p->p_ksi); 2179 PROC_UNLOCK(p->p_pptr); 2180 } 2181 } 2182 2183 ret = sigqueue_add(sigqueue, sig, ksi); 2184 if (ret != 0) 2185 return (ret); 2186 signotify(td); 2187 /* 2188 * Defer further processing for signals which are held, 2189 * except that stopped processes must be continued by SIGCONT. 2190 */ 2191 if (action == SIG_HOLD && 2192 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2193 return (ret); 2194 /* 2195 * SIGKILL: Remove procfs STOPEVENTs. 2196 */ 2197 if (sig == SIGKILL) { 2198 /* from procfs_ioctl.c: PIOCBIC */ 2199 p->p_stops = 0; 2200 /* from procfs_ioctl.c: PIOCCONT */ 2201 p->p_step = 0; 2202 wakeup(&p->p_step); 2203 } 2204 /* 2205 * Some signals have a process-wide effect and a per-thread 2206 * component. Most processing occurs when the process next 2207 * tries to cross the user boundary, however there are some 2208 * times when processing needs to be done immediatly, such as 2209 * waking up threads so that they can cross the user boundary. 2210 * We try do the per-process part here. 2211 */ 2212 if (P_SHOULDSTOP(p)) { 2213 /* 2214 * The process is in stopped mode. All the threads should be 2215 * either winding down or already on the suspended queue. 2216 */ 2217 if (p->p_flag & P_TRACED) { 2218 /* 2219 * The traced process is already stopped, 2220 * so no further action is necessary. 2221 * No signal can restart us. 2222 */ 2223 goto out; 2224 } 2225 2226 if (sig == SIGKILL) { 2227 /* 2228 * SIGKILL sets process running. 2229 * It will die elsewhere. 2230 * All threads must be restarted. 2231 */ 2232 p->p_flag &= ~P_STOPPED_SIG; 2233 goto runfast; 2234 } 2235 2236 if (prop & SA_CONT) { 2237 /* 2238 * If SIGCONT is default (or ignored), we continue the 2239 * process but don't leave the signal in sigqueue as 2240 * it has no further action. If SIGCONT is held, we 2241 * continue the process and leave the signal in 2242 * sigqueue. If the process catches SIGCONT, let it 2243 * handle the signal itself. If it isn't waiting on 2244 * an event, it goes back to run state. 2245 * Otherwise, process goes back to sleep state. 2246 */ 2247 p->p_flag &= ~P_STOPPED_SIG; 2248 if (p->p_numthreads == p->p_suspcount) { 2249 p->p_flag |= P_CONTINUED; 2250 p->p_xstat = SIGCONT; 2251 PROC_LOCK(p->p_pptr); 2252 childproc_continued(p); 2253 PROC_UNLOCK(p->p_pptr); 2254 } 2255 if (action == SIG_DFL) { 2256 sigqueue_delete(sigqueue, sig); 2257 } else if (action == SIG_CATCH) { 2258 /* 2259 * The process wants to catch it so it needs 2260 * to run at least one thread, but which one? 2261 * It would seem that the answer would be to 2262 * run an upcall in the next KSE to run, and 2263 * deliver the signal that way. In a NON KSE 2264 * process, we need to make sure that the 2265 * single thread is runnable asap. 2266 * XXXKSE for now however, make them all run. 2267 */ 2268 goto runfast; 2269 } 2270 /* 2271 * The signal is not ignored or caught. 2272 */ 2273 mtx_lock_spin(&sched_lock); 2274 thread_unsuspend(p); 2275 mtx_unlock_spin(&sched_lock); 2276 goto out; 2277 } 2278 2279 if (prop & SA_STOP) { 2280 /* 2281 * Already stopped, don't need to stop again 2282 * (If we did the shell could get confused). 2283 * Just make sure the signal STOP bit set. 2284 */ 2285 p->p_flag |= P_STOPPED_SIG; 2286 sigqueue_delete(sigqueue, sig); 2287 goto out; 2288 } 2289 2290 /* 2291 * All other kinds of signals: 2292 * If a thread is sleeping interruptibly, simulate a 2293 * wakeup so that when it is continued it will be made 2294 * runnable and can look at the signal. However, don't make 2295 * the PROCESS runnable, leave it stopped. 2296 * It may run a bit until it hits a thread_suspend_check(). 2297 */ 2298 mtx_lock_spin(&sched_lock); 2299 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2300 sleepq_abort(td, intrval); 2301 mtx_unlock_spin(&sched_lock); 2302 goto out; 2303 /* 2304 * Mutexes are short lived. Threads waiting on them will 2305 * hit thread_suspend_check() soon. 2306 */ 2307 } else if (p->p_state == PRS_NORMAL) { 2308 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2309 mtx_lock_spin(&sched_lock); 2310 tdsigwakeup(td, sig, action, intrval); 2311 mtx_unlock_spin(&sched_lock); 2312 goto out; 2313 } 2314 2315 MPASS(action == SIG_DFL); 2316 2317 if (prop & SA_STOP) { 2318 if (p->p_flag & P_PPWAIT) 2319 goto out; 2320 p->p_flag |= P_STOPPED_SIG; 2321 p->p_xstat = sig; 2322 mtx_lock_spin(&sched_lock); 2323 sig_suspend_threads(td, p, 1); 2324 if (p->p_numthreads == p->p_suspcount) { 2325 /* 2326 * only thread sending signal to another 2327 * process can reach here, if thread is sending 2328 * signal to its process, because thread does 2329 * not suspend itself here, p_numthreads 2330 * should never be equal to p_suspcount. 2331 */ 2332 thread_stopped(p); 2333 mtx_unlock_spin(&sched_lock); 2334 sigqueue_delete_proc(p, p->p_xstat); 2335 } else 2336 mtx_unlock_spin(&sched_lock); 2337 goto out; 2338 } 2339 else 2340 goto runfast; 2341 /* NOTREACHED */ 2342 } else { 2343 /* Not in "NORMAL" state. discard the signal. */ 2344 sigqueue_delete(sigqueue, sig); 2345 goto out; 2346 } 2347 2348 /* 2349 * The process is not stopped so we need to apply the signal to all the 2350 * running threads. 2351 */ 2352 2353 runfast: 2354 mtx_lock_spin(&sched_lock); 2355 tdsigwakeup(td, sig, action, intrval); 2356 thread_unsuspend(p); 2357 mtx_unlock_spin(&sched_lock); 2358 out: 2359 /* If we jump here, sched_lock should not be owned. */ 2360 mtx_assert(&sched_lock, MA_NOTOWNED); 2361 return (ret); 2362 } 2363 2364 /* 2365 * The force of a signal has been directed against a single 2366 * thread. We need to see what we can do about knocking it 2367 * out of any sleep it may be in etc. 2368 */ 2369 static void 2370 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2371 { 2372 struct proc *p = td->td_proc; 2373 register int prop; 2374 2375 PROC_LOCK_ASSERT(p, MA_OWNED); 2376 mtx_assert(&sched_lock, MA_OWNED); 2377 prop = sigprop(sig); 2378 2379 /* 2380 * Bring the priority of a thread up if we want it to get 2381 * killed in this lifetime. 2382 */ 2383 if (action == SIG_DFL && (prop & SA_KILL)) { 2384 if (p->p_nice > 0) 2385 sched_nice(td->td_proc, 0); 2386 if (td->td_priority > PUSER) 2387 sched_prio(td, PUSER); 2388 } 2389 2390 if (TD_ON_SLEEPQ(td)) { 2391 /* 2392 * If thread is sleeping uninterruptibly 2393 * we can't interrupt the sleep... the signal will 2394 * be noticed when the process returns through 2395 * trap() or syscall(). 2396 */ 2397 if ((td->td_flags & TDF_SINTR) == 0) 2398 return; 2399 /* 2400 * If SIGCONT is default (or ignored) and process is 2401 * asleep, we are finished; the process should not 2402 * be awakened. 2403 */ 2404 if ((prop & SA_CONT) && action == SIG_DFL) { 2405 mtx_unlock_spin(&sched_lock); 2406 sigqueue_delete(&p->p_sigqueue, sig); 2407 /* 2408 * It may be on either list in this state. 2409 * Remove from both for now. 2410 */ 2411 sigqueue_delete(&td->td_sigqueue, sig); 2412 mtx_lock_spin(&sched_lock); 2413 return; 2414 } 2415 2416 /* 2417 * Give low priority threads a better chance to run. 2418 */ 2419 if (td->td_priority > PUSER) 2420 sched_prio(td, PUSER); 2421 2422 sleepq_abort(td, intrval); 2423 } else { 2424 /* 2425 * Other states do nothing with the signal immediately, 2426 * other than kicking ourselves if we are running. 2427 * It will either never be noticed, or noticed very soon. 2428 */ 2429 #ifdef SMP 2430 if (TD_IS_RUNNING(td) && td != curthread) 2431 forward_signal(td); 2432 #endif 2433 } 2434 } 2435 2436 static void 2437 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2438 { 2439 struct thread *td2; 2440 2441 PROC_LOCK_ASSERT(p, MA_OWNED); 2442 mtx_assert(&sched_lock, MA_OWNED); 2443 2444 FOREACH_THREAD_IN_PROC(p, td2) { 2445 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2446 (td2->td_flags & TDF_SINTR) && 2447 !TD_IS_SUSPENDED(td2)) { 2448 thread_suspend_one(td2); 2449 } else { 2450 if (sending || td != td2) 2451 td2->td_flags |= TDF_ASTPENDING; 2452 #ifdef SMP 2453 if (TD_IS_RUNNING(td2) && td2 != td) 2454 forward_signal(td2); 2455 #endif 2456 } 2457 } 2458 } 2459 2460 int 2461 ptracestop(struct thread *td, int sig) 2462 { 2463 struct proc *p = td->td_proc; 2464 2465 PROC_LOCK_ASSERT(p, MA_OWNED); 2466 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2467 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2468 2469 mtx_lock_spin(&sched_lock); 2470 td->td_flags |= TDF_XSIG; 2471 mtx_unlock_spin(&sched_lock); 2472 td->td_xsig = sig; 2473 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2474 if (p->p_flag & P_SINGLE_EXIT) { 2475 mtx_lock_spin(&sched_lock); 2476 td->td_flags &= ~TDF_XSIG; 2477 mtx_unlock_spin(&sched_lock); 2478 return (sig); 2479 } 2480 /* 2481 * Just make wait() to work, the last stopped thread 2482 * will win. 2483 */ 2484 p->p_xstat = sig; 2485 p->p_xthread = td; 2486 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2487 mtx_lock_spin(&sched_lock); 2488 sig_suspend_threads(td, p, 0); 2489 stopme: 2490 thread_stopped(p); 2491 thread_suspend_one(td); 2492 PROC_UNLOCK(p); 2493 DROP_GIANT(); 2494 mi_switch(SW_VOL, NULL); 2495 mtx_unlock_spin(&sched_lock); 2496 PICKUP_GIANT(); 2497 PROC_LOCK(p); 2498 if (!(p->p_flag & P_TRACED)) 2499 break; 2500 if (td->td_flags & TDF_DBSUSPEND) { 2501 if (p->p_flag & P_SINGLE_EXIT) 2502 break; 2503 mtx_lock_spin(&sched_lock); 2504 goto stopme; 2505 } 2506 } 2507 return (td->td_xsig); 2508 } 2509 2510 /* 2511 * If the current process has received a signal (should be caught or cause 2512 * termination, should interrupt current syscall), return the signal number. 2513 * Stop signals with default action are processed immediately, then cleared; 2514 * they aren't returned. This is checked after each entry to the system for 2515 * a syscall or trap (though this can usually be done without calling issignal 2516 * by checking the pending signal masks in cursig.) The normal call 2517 * sequence is 2518 * 2519 * while (sig = cursig(curthread)) 2520 * postsig(sig); 2521 */ 2522 static int 2523 issignal(td) 2524 struct thread *td; 2525 { 2526 struct proc *p; 2527 struct sigacts *ps; 2528 sigset_t sigpending; 2529 int sig, prop, newsig; 2530 2531 p = td->td_proc; 2532 ps = p->p_sigacts; 2533 mtx_assert(&ps->ps_mtx, MA_OWNED); 2534 PROC_LOCK_ASSERT(p, MA_OWNED); 2535 for (;;) { 2536 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2537 2538 sigpending = td->td_sigqueue.sq_signals; 2539 SIGSETNAND(sigpending, td->td_sigmask); 2540 2541 if (p->p_flag & P_PPWAIT) 2542 SIG_STOPSIGMASK(sigpending); 2543 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2544 return (0); 2545 sig = sig_ffs(&sigpending); 2546 2547 if (p->p_stops & S_SIG) { 2548 mtx_unlock(&ps->ps_mtx); 2549 stopevent(p, S_SIG, sig); 2550 mtx_lock(&ps->ps_mtx); 2551 } 2552 2553 /* 2554 * We should see pending but ignored signals 2555 * only if P_TRACED was on when they were posted. 2556 */ 2557 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2558 sigqueue_delete(&td->td_sigqueue, sig); 2559 if (td->td_pflags & TDP_SA) 2560 SIGADDSET(td->td_sigmask, sig); 2561 continue; 2562 } 2563 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2564 /* 2565 * If traced, always stop. 2566 */ 2567 mtx_unlock(&ps->ps_mtx); 2568 newsig = ptracestop(td, sig); 2569 mtx_lock(&ps->ps_mtx); 2570 2571 if (td->td_pflags & TDP_SA) 2572 SIGADDSET(td->td_sigmask, sig); 2573 2574 if (sig != newsig) { 2575 ksiginfo_t ksi; 2576 /* 2577 * clear old signal. 2578 * XXX shrug off debugger, it causes siginfo to 2579 * be thrown away. 2580 */ 2581 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2582 2583 /* 2584 * If parent wants us to take the signal, 2585 * then it will leave it in p->p_xstat; 2586 * otherwise we just look for signals again. 2587 */ 2588 if (newsig == 0) 2589 continue; 2590 sig = newsig; 2591 2592 /* 2593 * Put the new signal into td_sigqueue. If the 2594 * signal is being masked, look for other signals. 2595 */ 2596 SIGADDSET(td->td_sigqueue.sq_signals, sig); 2597 if (td->td_pflags & TDP_SA) 2598 SIGDELSET(td->td_sigmask, sig); 2599 if (SIGISMEMBER(td->td_sigmask, sig)) 2600 continue; 2601 signotify(td); 2602 } 2603 2604 /* 2605 * If the traced bit got turned off, go back up 2606 * to the top to rescan signals. This ensures 2607 * that p_sig* and p_sigact are consistent. 2608 */ 2609 if ((p->p_flag & P_TRACED) == 0) 2610 continue; 2611 } 2612 2613 prop = sigprop(sig); 2614 2615 /* 2616 * Decide whether the signal should be returned. 2617 * Return the signal's number, or fall through 2618 * to clear it from the pending mask. 2619 */ 2620 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2621 2622 case (intptr_t)SIG_DFL: 2623 /* 2624 * Don't take default actions on system processes. 2625 */ 2626 if (p->p_pid <= 1) { 2627 #ifdef DIAGNOSTIC 2628 /* 2629 * Are you sure you want to ignore SIGSEGV 2630 * in init? XXX 2631 */ 2632 printf("Process (pid %lu) got signal %d\n", 2633 (u_long)p->p_pid, sig); 2634 #endif 2635 break; /* == ignore */ 2636 } 2637 /* 2638 * If there is a pending stop signal to process 2639 * with default action, stop here, 2640 * then clear the signal. However, 2641 * if process is member of an orphaned 2642 * process group, ignore tty stop signals. 2643 */ 2644 if (prop & SA_STOP) { 2645 if (p->p_flag & P_TRACED || 2646 (p->p_pgrp->pg_jobc == 0 && 2647 prop & SA_TTYSTOP)) 2648 break; /* == ignore */ 2649 mtx_unlock(&ps->ps_mtx); 2650 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2651 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2652 p->p_flag |= P_STOPPED_SIG; 2653 p->p_xstat = sig; 2654 mtx_lock_spin(&sched_lock); 2655 sig_suspend_threads(td, p, 0); 2656 thread_stopped(p); 2657 thread_suspend_one(td); 2658 PROC_UNLOCK(p); 2659 DROP_GIANT(); 2660 mi_switch(SW_INVOL, NULL); 2661 mtx_unlock_spin(&sched_lock); 2662 PICKUP_GIANT(); 2663 PROC_LOCK(p); 2664 mtx_lock(&ps->ps_mtx); 2665 break; 2666 } else if (prop & SA_IGNORE) { 2667 /* 2668 * Except for SIGCONT, shouldn't get here. 2669 * Default action is to ignore; drop it. 2670 */ 2671 break; /* == ignore */ 2672 } else 2673 return (sig); 2674 /*NOTREACHED*/ 2675 2676 case (intptr_t)SIG_IGN: 2677 /* 2678 * Masking above should prevent us ever trying 2679 * to take action on an ignored signal other 2680 * than SIGCONT, unless process is traced. 2681 */ 2682 if ((prop & SA_CONT) == 0 && 2683 (p->p_flag & P_TRACED) == 0) 2684 printf("issignal\n"); 2685 break; /* == ignore */ 2686 2687 default: 2688 /* 2689 * This signal has an action, let 2690 * postsig() process it. 2691 */ 2692 return (sig); 2693 } 2694 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2695 } 2696 /* NOTREACHED */ 2697 } 2698 2699 /* 2700 * MPSAFE 2701 */ 2702 void 2703 thread_stopped(struct proc *p) 2704 { 2705 int n; 2706 2707 PROC_LOCK_ASSERT(p, MA_OWNED); 2708 mtx_assert(&sched_lock, MA_OWNED); 2709 n = p->p_suspcount; 2710 if (p == curproc) 2711 n++; 2712 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2713 mtx_unlock_spin(&sched_lock); 2714 p->p_flag &= ~P_WAITED; 2715 PROC_LOCK(p->p_pptr); 2716 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2717 CLD_TRAPPED : CLD_STOPPED); 2718 PROC_UNLOCK(p->p_pptr); 2719 mtx_lock_spin(&sched_lock); 2720 } 2721 } 2722 2723 /* 2724 * Take the action for the specified signal 2725 * from the current set of pending signals. 2726 */ 2727 void 2728 postsig(sig) 2729 register int sig; 2730 { 2731 struct thread *td = curthread; 2732 register struct proc *p = td->td_proc; 2733 struct sigacts *ps; 2734 sig_t action; 2735 ksiginfo_t ksi; 2736 sigset_t returnmask; 2737 int code; 2738 2739 KASSERT(sig != 0, ("postsig")); 2740 2741 PROC_LOCK_ASSERT(p, MA_OWNED); 2742 ps = p->p_sigacts; 2743 mtx_assert(&ps->ps_mtx, MA_OWNED); 2744 ksiginfo_init(&ksi); 2745 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2746 ksi.ksi_signo = sig; 2747 if (ksi.ksi_code == SI_TIMER) 2748 itimer_accept(p, ksi.ksi_timerid, &ksi); 2749 action = ps->ps_sigact[_SIG_IDX(sig)]; 2750 #ifdef KTRACE 2751 if (KTRPOINT(td, KTR_PSIG)) 2752 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2753 &td->td_oldsigmask : &td->td_sigmask, 0); 2754 #endif 2755 if (p->p_stops & S_SIG) { 2756 mtx_unlock(&ps->ps_mtx); 2757 stopevent(p, S_SIG, sig); 2758 mtx_lock(&ps->ps_mtx); 2759 } 2760 2761 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2762 /* 2763 * Default action, where the default is to kill 2764 * the process. (Other cases were ignored above.) 2765 */ 2766 mtx_unlock(&ps->ps_mtx); 2767 sigexit(td, sig); 2768 /* NOTREACHED */ 2769 } else { 2770 if (td->td_pflags & TDP_SA) { 2771 if (sig == SIGKILL) { 2772 mtx_unlock(&ps->ps_mtx); 2773 sigexit(td, sig); 2774 } 2775 } 2776 2777 /* 2778 * If we get here, the signal must be caught. 2779 */ 2780 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2781 ("postsig action")); 2782 /* 2783 * Set the new mask value and also defer further 2784 * occurrences of this signal. 2785 * 2786 * Special case: user has done a sigsuspend. Here the 2787 * current mask is not of interest, but rather the 2788 * mask from before the sigsuspend is what we want 2789 * restored after the signal processing is completed. 2790 */ 2791 if (td->td_pflags & TDP_OLDMASK) { 2792 returnmask = td->td_oldsigmask; 2793 td->td_pflags &= ~TDP_OLDMASK; 2794 } else 2795 returnmask = td->td_sigmask; 2796 2797 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2798 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2799 SIGADDSET(td->td_sigmask, sig); 2800 2801 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2802 /* 2803 * See kern_sigaction() for origin of this code. 2804 */ 2805 SIGDELSET(ps->ps_sigcatch, sig); 2806 if (sig != SIGCONT && 2807 sigprop(sig) & SA_IGNORE) 2808 SIGADDSET(ps->ps_sigignore, sig); 2809 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2810 } 2811 p->p_stats->p_ru.ru_nsignals++; 2812 if (p->p_sig != sig) { 2813 code = 0; 2814 } else { 2815 code = p->p_code; 2816 p->p_code = 0; 2817 p->p_sig = 0; 2818 } 2819 if (td->td_pflags & TDP_SA) 2820 thread_signal_add(curthread, &ksi); 2821 else 2822 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2823 } 2824 } 2825 2826 /* 2827 * Kill the current process for stated reason. 2828 */ 2829 void 2830 killproc(p, why) 2831 struct proc *p; 2832 char *why; 2833 { 2834 2835 PROC_LOCK_ASSERT(p, MA_OWNED); 2836 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2837 p, p->p_pid, p->p_comm); 2838 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2839 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2840 psignal(p, SIGKILL); 2841 } 2842 2843 /* 2844 * Force the current process to exit with the specified signal, dumping core 2845 * if appropriate. We bypass the normal tests for masked and caught signals, 2846 * allowing unrecoverable failures to terminate the process without changing 2847 * signal state. Mark the accounting record with the signal termination. 2848 * If dumping core, save the signal number for the debugger. Calls exit and 2849 * does not return. 2850 * 2851 * MPSAFE 2852 */ 2853 void 2854 sigexit(td, sig) 2855 struct thread *td; 2856 int sig; 2857 { 2858 struct proc *p = td->td_proc; 2859 2860 PROC_LOCK_ASSERT(p, MA_OWNED); 2861 p->p_acflag |= AXSIG; 2862 /* 2863 * We must be single-threading to generate a core dump. This 2864 * ensures that the registers in the core file are up-to-date. 2865 * Also, the ELF dump handler assumes that the thread list doesn't 2866 * change out from under it. 2867 * 2868 * XXX If another thread attempts to single-thread before us 2869 * (e.g. via fork()), we won't get a dump at all. 2870 */ 2871 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2872 p->p_sig = sig; 2873 /* 2874 * Log signals which would cause core dumps 2875 * (Log as LOG_INFO to appease those who don't want 2876 * these messages.) 2877 * XXX : Todo, as well as euid, write out ruid too 2878 * Note that coredump() drops proc lock. 2879 */ 2880 if (coredump(td) == 0) 2881 sig |= WCOREFLAG; 2882 if (kern_logsigexit) 2883 log(LOG_INFO, 2884 "pid %d (%s), uid %d: exited on signal %d%s\n", 2885 p->p_pid, p->p_comm, 2886 td->td_ucred ? td->td_ucred->cr_uid : -1, 2887 sig &~ WCOREFLAG, 2888 sig & WCOREFLAG ? " (core dumped)" : ""); 2889 } else 2890 PROC_UNLOCK(p); 2891 exit1(td, W_EXITCODE(0, sig)); 2892 /* NOTREACHED */ 2893 } 2894 2895 /* 2896 * Send queued SIGCHLD to parent when child process's state 2897 * is changed. 2898 */ 2899 static void 2900 sigparent(struct proc *p, int reason, int status) 2901 { 2902 PROC_LOCK_ASSERT(p, MA_OWNED); 2903 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2904 2905 if (p->p_ksi != NULL) { 2906 p->p_ksi->ksi_signo = SIGCHLD; 2907 p->p_ksi->ksi_code = reason; 2908 p->p_ksi->ksi_status = status; 2909 p->p_ksi->ksi_pid = p->p_pid; 2910 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2911 if (KSI_ONQ(p->p_ksi)) 2912 return; 2913 } 2914 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2915 } 2916 2917 static void 2918 childproc_jobstate(struct proc *p, int reason, int status) 2919 { 2920 struct sigacts *ps; 2921 2922 PROC_LOCK_ASSERT(p, MA_OWNED); 2923 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2924 2925 /* 2926 * Wake up parent sleeping in kern_wait(), also send 2927 * SIGCHLD to parent, but SIGCHLD does not guarantee 2928 * that parent will awake, because parent may masked 2929 * the signal. 2930 */ 2931 p->p_pptr->p_flag |= P_STATCHILD; 2932 wakeup(p->p_pptr); 2933 2934 ps = p->p_pptr->p_sigacts; 2935 mtx_lock(&ps->ps_mtx); 2936 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2937 mtx_unlock(&ps->ps_mtx); 2938 sigparent(p, reason, status); 2939 } else 2940 mtx_unlock(&ps->ps_mtx); 2941 } 2942 2943 void 2944 childproc_stopped(struct proc *p, int reason) 2945 { 2946 childproc_jobstate(p, reason, p->p_xstat); 2947 } 2948 2949 void 2950 childproc_continued(struct proc *p) 2951 { 2952 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2953 } 2954 2955 void 2956 childproc_exited(struct proc *p) 2957 { 2958 int reason; 2959 int status = p->p_xstat; /* convert to int */ 2960 2961 reason = CLD_EXITED; 2962 if (WCOREDUMP(status)) 2963 reason = CLD_DUMPED; 2964 else if (WIFSIGNALED(status)) 2965 reason = CLD_KILLED; 2966 /* 2967 * XXX avoid calling wakeup(p->p_pptr), the work is 2968 * done in exit1(). 2969 */ 2970 sigparent(p, reason, status); 2971 } 2972 2973 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2974 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2975 sizeof(corefilename), "process corefile name format string"); 2976 2977 /* 2978 * expand_name(name, uid, pid) 2979 * Expand the name described in corefilename, using name, uid, and pid. 2980 * corefilename is a printf-like string, with three format specifiers: 2981 * %N name of process ("name") 2982 * %P process id (pid) 2983 * %U user id (uid) 2984 * For example, "%N.core" is the default; they can be disabled completely 2985 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2986 * This is controlled by the sysctl variable kern.corefile (see above). 2987 */ 2988 2989 static char * 2990 expand_name(name, uid, pid) 2991 const char *name; 2992 uid_t uid; 2993 pid_t pid; 2994 { 2995 const char *format, *appendstr; 2996 char *temp; 2997 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2998 size_t i, l, n; 2999 3000 format = corefilename; 3001 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 3002 if (temp == NULL) 3003 return (NULL); 3004 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 3005 switch (format[i]) { 3006 case '%': /* Format character */ 3007 i++; 3008 switch (format[i]) { 3009 case '%': 3010 appendstr = "%"; 3011 break; 3012 case 'N': /* process name */ 3013 appendstr = name; 3014 break; 3015 case 'P': /* process id */ 3016 sprintf(buf, "%u", pid); 3017 appendstr = buf; 3018 break; 3019 case 'U': /* user id */ 3020 sprintf(buf, "%u", uid); 3021 appendstr = buf; 3022 break; 3023 default: 3024 appendstr = ""; 3025 log(LOG_ERR, 3026 "Unknown format character %c in `%s'\n", 3027 format[i], format); 3028 } 3029 l = strlen(appendstr); 3030 if ((n + l) >= MAXPATHLEN) 3031 goto toolong; 3032 memcpy(temp + n, appendstr, l); 3033 n += l; 3034 break; 3035 default: 3036 temp[n++] = format[i]; 3037 } 3038 } 3039 if (format[i] != '\0') 3040 goto toolong; 3041 return (temp); 3042 toolong: 3043 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 3044 (long)pid, name, (u_long)uid); 3045 free(temp, M_TEMP); 3046 return (NULL); 3047 } 3048 3049 /* 3050 * Dump a process' core. The main routine does some 3051 * policy checking, and creates the name of the coredump; 3052 * then it passes on a vnode and a size limit to the process-specific 3053 * coredump routine if there is one; if there _is not_ one, it returns 3054 * ENOSYS; otherwise it returns the error from the process-specific routine. 3055 */ 3056 3057 static int 3058 coredump(struct thread *td) 3059 { 3060 struct proc *p = td->td_proc; 3061 register struct vnode *vp; 3062 register struct ucred *cred = td->td_ucred; 3063 struct flock lf; 3064 struct nameidata nd; 3065 struct vattr vattr; 3066 int error, error1, flags, locked; 3067 struct mount *mp; 3068 char *name; /* name of corefile */ 3069 off_t limit; 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 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3076 PROC_UNLOCK(p); 3077 return (EFAULT); 3078 } 3079 3080 /* 3081 * Note that the bulk of limit checking is done after 3082 * the corefile is created. The exception is if the limit 3083 * for corefiles is 0, in which case we don't bother 3084 * creating the corefile at all. This layout means that 3085 * a corefile is truncated instead of not being created, 3086 * if it is larger than the limit. 3087 */ 3088 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3089 PROC_UNLOCK(p); 3090 if (limit == 0) 3091 return (EFBIG); 3092 3093 mtx_lock(&Giant); 3094 restart: 3095 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3096 if (name == NULL) { 3097 mtx_unlock(&Giant); 3098 return (EINVAL); 3099 } 3100 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 3101 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3102 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 3103 free(name, M_TEMP); 3104 if (error) { 3105 mtx_unlock(&Giant); 3106 return (error); 3107 } 3108 NDFREE(&nd, NDF_ONLY_PNBUF); 3109 vp = nd.ni_vp; 3110 3111 /* Don't dump to non-regular files or files with links. */ 3112 if (vp->v_type != VREG || 3113 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 3114 VOP_UNLOCK(vp, 0, td); 3115 error = EFAULT; 3116 goto out; 3117 } 3118 3119 VOP_UNLOCK(vp, 0, td); 3120 lf.l_whence = SEEK_SET; 3121 lf.l_start = 0; 3122 lf.l_len = 0; 3123 lf.l_type = F_WRLCK; 3124 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3125 3126 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3127 lf.l_type = F_UNLCK; 3128 if (locked) 3129 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3130 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3131 return (error); 3132 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3133 return (error); 3134 goto restart; 3135 } 3136 3137 VATTR_NULL(&vattr); 3138 vattr.va_size = 0; 3139 if (set_core_nodump_flag) 3140 vattr.va_flags = UF_NODUMP; 3141 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 3142 VOP_LEASE(vp, td, cred, LEASE_WRITE); 3143 VOP_SETATTR(vp, &vattr, cred, td); 3144 VOP_UNLOCK(vp, 0, td); 3145 PROC_LOCK(p); 3146 p->p_acflag |= ACORE; 3147 PROC_UNLOCK(p); 3148 3149 error = p->p_sysent->sv_coredump ? 3150 p->p_sysent->sv_coredump(td, vp, limit) : 3151 ENOSYS; 3152 3153 if (locked) { 3154 lf.l_type = F_UNLCK; 3155 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3156 } 3157 vn_finished_write(mp); 3158 out: 3159 error1 = vn_close(vp, FWRITE, cred, td); 3160 mtx_unlock(&Giant); 3161 if (error == 0) 3162 error = error1; 3163 return (error); 3164 } 3165 3166 /* 3167 * Nonexistent system call-- signal process (may want to handle it). 3168 * Flag error in case process won't see signal immediately (blocked or ignored). 3169 */ 3170 #ifndef _SYS_SYSPROTO_H_ 3171 struct nosys_args { 3172 int dummy; 3173 }; 3174 #endif 3175 /* 3176 * MPSAFE 3177 */ 3178 /* ARGSUSED */ 3179 int 3180 nosys(td, args) 3181 struct thread *td; 3182 struct nosys_args *args; 3183 { 3184 struct proc *p = td->td_proc; 3185 3186 PROC_LOCK(p); 3187 psignal(p, SIGSYS); 3188 PROC_UNLOCK(p); 3189 return (ENOSYS); 3190 } 3191 3192 /* 3193 * Send a SIGIO or SIGURG signal to a process or process group using 3194 * stored credentials rather than those of the current process. 3195 */ 3196 void 3197 pgsigio(sigiop, sig, checkctty) 3198 struct sigio **sigiop; 3199 int sig, checkctty; 3200 { 3201 struct sigio *sigio; 3202 3203 SIGIO_LOCK(); 3204 sigio = *sigiop; 3205 if (sigio == NULL) { 3206 SIGIO_UNLOCK(); 3207 return; 3208 } 3209 if (sigio->sio_pgid > 0) { 3210 PROC_LOCK(sigio->sio_proc); 3211 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3212 psignal(sigio->sio_proc, sig); 3213 PROC_UNLOCK(sigio->sio_proc); 3214 } else if (sigio->sio_pgid < 0) { 3215 struct proc *p; 3216 3217 PGRP_LOCK(sigio->sio_pgrp); 3218 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3219 PROC_LOCK(p); 3220 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3221 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3222 psignal(p, sig); 3223 PROC_UNLOCK(p); 3224 } 3225 PGRP_UNLOCK(sigio->sio_pgrp); 3226 } 3227 SIGIO_UNLOCK(); 3228 } 3229 3230 static int 3231 filt_sigattach(struct knote *kn) 3232 { 3233 struct proc *p = curproc; 3234 3235 kn->kn_ptr.p_proc = p; 3236 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3237 3238 knlist_add(&p->p_klist, kn, 0); 3239 3240 return (0); 3241 } 3242 3243 static void 3244 filt_sigdetach(struct knote *kn) 3245 { 3246 struct proc *p = kn->kn_ptr.p_proc; 3247 3248 knlist_remove(&p->p_klist, kn, 0); 3249 } 3250 3251 /* 3252 * signal knotes are shared with proc knotes, so we apply a mask to 3253 * the hint in order to differentiate them from process hints. This 3254 * could be avoided by using a signal-specific knote list, but probably 3255 * isn't worth the trouble. 3256 */ 3257 static int 3258 filt_signal(struct knote *kn, long hint) 3259 { 3260 3261 if (hint & NOTE_SIGNAL) { 3262 hint &= ~NOTE_SIGNAL; 3263 3264 if (kn->kn_id == hint) 3265 kn->kn_data++; 3266 } 3267 return (kn->kn_data != 0); 3268 } 3269 3270 struct sigacts * 3271 sigacts_alloc(void) 3272 { 3273 struct sigacts *ps; 3274 3275 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3276 ps->ps_refcnt = 1; 3277 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3278 return (ps); 3279 } 3280 3281 void 3282 sigacts_free(struct sigacts *ps) 3283 { 3284 3285 mtx_lock(&ps->ps_mtx); 3286 ps->ps_refcnt--; 3287 if (ps->ps_refcnt == 0) { 3288 mtx_destroy(&ps->ps_mtx); 3289 free(ps, M_SUBPROC); 3290 } else 3291 mtx_unlock(&ps->ps_mtx); 3292 } 3293 3294 struct sigacts * 3295 sigacts_hold(struct sigacts *ps) 3296 { 3297 mtx_lock(&ps->ps_mtx); 3298 ps->ps_refcnt++; 3299 mtx_unlock(&ps->ps_mtx); 3300 return (ps); 3301 } 3302 3303 void 3304 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3305 { 3306 3307 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3308 mtx_lock(&src->ps_mtx); 3309 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3310 mtx_unlock(&src->ps_mtx); 3311 } 3312 3313 int 3314 sigacts_shared(struct sigacts *ps) 3315 { 3316 int shared; 3317 3318 mtx_lock(&ps->ps_mtx); 3319 shared = ps->ps_refcnt > 1; 3320 mtx_unlock(&ps->ps_mtx); 3321 return (shared); 3322 } 3323