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 #if defined (__alpha__) && !defined(COMPAT_43) 83 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 84 #endif 85 86 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 87 88 static int coredump(struct thread *); 89 static char *expand_name(const char *, uid_t, pid_t); 90 static int killpg1(struct thread *td, int sig, int pgid, int all); 91 static int issignal(struct thread *p); 92 static int sigprop(int sig); 93 static void tdsigwakeup(struct thread *, int, sig_t); 94 static void sig_suspend_threads(struct thread *, struct proc *, int); 95 static int filt_sigattach(struct knote *kn); 96 static void filt_sigdetach(struct knote *kn); 97 static int filt_signal(struct knote *kn, long hint); 98 static struct thread *sigtd(struct proc *p, int sig, int prop); 99 static int kern_sigtimedwait(struct thread *, sigset_t, 100 ksiginfo_t *, struct timespec *); 101 static int do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *); 102 static void sigqueue_start(void); 103 104 static uma_zone_t ksiginfo_zone = NULL; 105 struct filterops sig_filtops = 106 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 107 108 static int kern_logsigexit = 1; 109 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 110 &kern_logsigexit, 0, 111 "Log processes quitting on abnormal signals to syslog(3)"); 112 113 static int kern_forcesigexit = 1; 114 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 115 &kern_forcesigexit, 0, "Force trap signal to be handled"); 116 117 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 118 119 static int max_pending_per_proc = 128; 120 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 121 &max_pending_per_proc, 0, "Max pending signals per proc"); 122 123 static int preallocate_siginfo = 1024; 124 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 125 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 126 &preallocate_siginfo, 0, "Preallocated signal memory size"); 127 128 static int signal_overflow = 0; 129 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 130 &signal_overflow, 0, "Number of signals overflew"); 131 132 static int signal_alloc_fail = 0; 133 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 134 &signal_alloc_fail, 0, "signals failed to be allocated"); 135 136 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 137 138 /* 139 * Policy -- Can ucred cr1 send SIGIO to process cr2? 140 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 141 * in the right situations. 142 */ 143 #define CANSIGIO(cr1, cr2) \ 144 ((cr1)->cr_uid == 0 || \ 145 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 146 (cr1)->cr_uid == (cr2)->cr_ruid || \ 147 (cr1)->cr_ruid == (cr2)->cr_uid || \ 148 (cr1)->cr_uid == (cr2)->cr_uid) 149 150 int sugid_coredump; 151 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 152 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 153 154 static int do_coredump = 1; 155 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 156 &do_coredump, 0, "Enable/Disable coredumps"); 157 158 static int set_core_nodump_flag = 0; 159 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 160 0, "Enable setting the NODUMP flag on coredump files"); 161 162 /* 163 * Signal properties and actions. 164 * The array below categorizes the signals and their default actions 165 * according to the following properties: 166 */ 167 #define SA_KILL 0x01 /* terminates process by default */ 168 #define SA_CORE 0x02 /* ditto and coredumps */ 169 #define SA_STOP 0x04 /* suspend process */ 170 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 171 #define SA_IGNORE 0x10 /* ignore by default */ 172 #define SA_CONT 0x20 /* continue if suspended */ 173 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 174 #define SA_PROC 0x80 /* deliverable to any thread */ 175 176 static int sigproptbl[NSIG] = { 177 SA_KILL|SA_PROC, /* SIGHUP */ 178 SA_KILL|SA_PROC, /* SIGINT */ 179 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 180 SA_KILL|SA_CORE, /* SIGILL */ 181 SA_KILL|SA_CORE, /* SIGTRAP */ 182 SA_KILL|SA_CORE, /* SIGABRT */ 183 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 184 SA_KILL|SA_CORE, /* SIGFPE */ 185 SA_KILL|SA_PROC, /* SIGKILL */ 186 SA_KILL|SA_CORE, /* SIGBUS */ 187 SA_KILL|SA_CORE, /* SIGSEGV */ 188 SA_KILL|SA_CORE, /* SIGSYS */ 189 SA_KILL|SA_PROC, /* SIGPIPE */ 190 SA_KILL|SA_PROC, /* SIGALRM */ 191 SA_KILL|SA_PROC, /* SIGTERM */ 192 SA_IGNORE|SA_PROC, /* SIGURG */ 193 SA_STOP|SA_PROC, /* SIGSTOP */ 194 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 195 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 196 SA_IGNORE|SA_PROC, /* SIGCHLD */ 197 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 198 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 199 SA_IGNORE|SA_PROC, /* SIGIO */ 200 SA_KILL, /* SIGXCPU */ 201 SA_KILL, /* SIGXFSZ */ 202 SA_KILL|SA_PROC, /* SIGVTALRM */ 203 SA_KILL|SA_PROC, /* SIGPROF */ 204 SA_IGNORE|SA_PROC, /* SIGWINCH */ 205 SA_IGNORE|SA_PROC, /* SIGINFO */ 206 SA_KILL|SA_PROC, /* SIGUSR1 */ 207 SA_KILL|SA_PROC, /* SIGUSR2 */ 208 }; 209 210 static void 211 sigqueue_start(void) 212 { 213 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 214 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 215 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 216 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 217 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 218 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 219 } 220 221 ksiginfo_t * 222 ksiginfo_alloc(int wait) 223 { 224 int flags; 225 226 flags = M_ZERO; 227 if (! wait) 228 flags |= M_NOWAIT; 229 if (ksiginfo_zone != NULL) 230 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 231 return (NULL); 232 } 233 234 void 235 ksiginfo_free(ksiginfo_t *ksi) 236 { 237 uma_zfree(ksiginfo_zone, ksi); 238 } 239 240 static __inline int 241 ksiginfo_tryfree(ksiginfo_t *ksi) 242 { 243 if (!(ksi->ksi_flags & KSI_EXT)) { 244 uma_zfree(ksiginfo_zone, ksi); 245 return (1); 246 } 247 return (0); 248 } 249 250 void 251 sigqueue_init(sigqueue_t *list, struct proc *p) 252 { 253 SIGEMPTYSET(list->sq_signals); 254 TAILQ_INIT(&list->sq_list); 255 list->sq_proc = p; 256 list->sq_flags = SQ_INIT; 257 } 258 259 /* 260 * Get a signal's ksiginfo. 261 * Return: 262 * 0 - signal not found 263 * others - signal number 264 */ 265 int 266 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 267 { 268 struct proc *p = sq->sq_proc; 269 struct ksiginfo *ksi, *next; 270 int count = 0; 271 272 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 273 274 if (!SIGISMEMBER(sq->sq_signals, signo)) 275 return (0); 276 277 for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { 278 next = TAILQ_NEXT(ksi, ksi_link); 279 if (ksi->ksi_signo == signo) { 280 if (count == 0) { 281 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 282 ksi->ksi_sigq = NULL; 283 ksiginfo_copy(ksi, si); 284 if (ksiginfo_tryfree(ksi) && p != NULL) 285 p->p_pendingcnt--; 286 } 287 count++; 288 } 289 } 290 291 if (count <= 1) 292 SIGDELSET(sq->sq_signals, signo); 293 si->ksi_signo = signo; 294 return (signo); 295 } 296 297 void 298 sigqueue_take(ksiginfo_t *ksi) 299 { 300 struct ksiginfo *kp; 301 struct proc *p; 302 sigqueue_t *sq; 303 304 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 305 return; 306 307 p = sq->sq_proc; 308 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 309 ksi->ksi_sigq = NULL; 310 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 311 p->p_pendingcnt--; 312 313 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 314 kp = TAILQ_NEXT(kp, ksi_link)) { 315 if (kp->ksi_signo == ksi->ksi_signo) 316 break; 317 } 318 if (kp == NULL) 319 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 320 } 321 322 int 323 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 324 { 325 struct proc *p = sq->sq_proc; 326 struct ksiginfo *ksi; 327 int ret = 0; 328 329 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 330 331 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) 332 goto out_set_bit; 333 334 /* directly insert the ksi, don't copy it */ 335 if (si->ksi_flags & KSI_INS) { 336 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 337 si->ksi_sigq = sq; 338 goto out_set_bit; 339 } 340 341 if (__predict_false(ksiginfo_zone == NULL)) 342 goto out_set_bit; 343 344 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 345 signal_overflow++; 346 ret = EAGAIN; 347 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 348 signal_alloc_fail++; 349 ret = EAGAIN; 350 } else { 351 if (p != NULL) 352 p->p_pendingcnt++; 353 ksiginfo_copy(si, ksi); 354 ksi->ksi_signo = signo; 355 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 356 ksi->ksi_sigq = sq; 357 } 358 359 if ((si->ksi_flags & KSI_TRAP) != 0) { 360 ret = 0; 361 goto out_set_bit; 362 } 363 364 if (ret != 0) 365 return (ret); 366 367 out_set_bit: 368 SIGADDSET(sq->sq_signals, signo); 369 return (ret); 370 } 371 372 void 373 sigqueue_flush(sigqueue_t *sq) 374 { 375 struct proc *p = sq->sq_proc; 376 ksiginfo_t *ksi; 377 378 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 379 380 if (p != NULL) 381 PROC_LOCK_ASSERT(p, MA_OWNED); 382 383 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 384 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 385 ksi->ksi_sigq = NULL; 386 if (ksiginfo_tryfree(ksi) && p != NULL) 387 p->p_pendingcnt--; 388 } 389 390 SIGEMPTYSET(sq->sq_signals); 391 } 392 393 void 394 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 395 { 396 ksiginfo_t *ksi; 397 398 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 399 400 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 401 SIGADDSET(*set, ksi->ksi_signo); 402 } 403 404 void 405 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 406 { 407 sigset_t tmp, set; 408 struct proc *p1, *p2; 409 ksiginfo_t *ksi, *next; 410 411 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 412 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 413 /* 414 * make a copy, this allows setp to point to src or dst 415 * sq_signals without trouble. 416 */ 417 set = *setp; 418 p1 = src->sq_proc; 419 p2 = dst->sq_proc; 420 /* Move siginfo to target list */ 421 for (ksi = TAILQ_FIRST(&src->sq_list); ksi != NULL; ksi = next) { 422 next = TAILQ_NEXT(ksi, ksi_link); 423 if (SIGISMEMBER(set, ksi->ksi_signo)) { 424 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 425 if (p1 != NULL) 426 p1->p_pendingcnt--; 427 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 428 ksi->ksi_sigq = dst; 429 if (p2 != NULL) 430 p2->p_pendingcnt++; 431 } 432 } 433 434 /* Move pending bits to target list */ 435 tmp = src->sq_signals; 436 SIGSETAND(tmp, set); 437 SIGSETOR(dst->sq_signals, tmp); 438 SIGSETNAND(src->sq_signals, tmp); 439 440 /* Finally, rescan src queue and set pending bits for it */ 441 sigqueue_collect_set(src, &src->sq_signals); 442 } 443 444 void 445 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 446 { 447 sigset_t set; 448 449 SIGEMPTYSET(set); 450 SIGADDSET(set, signo); 451 sigqueue_move_set(src, dst, &set); 452 } 453 454 void 455 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 456 { 457 struct proc *p = sq->sq_proc; 458 ksiginfo_t *ksi, *next; 459 460 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 461 462 /* Remove siginfo queue */ 463 for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { 464 next = TAILQ_NEXT(ksi, ksi_link); 465 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 466 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 467 ksi->ksi_sigq = NULL; 468 if (ksiginfo_tryfree(ksi) && p != NULL) 469 p->p_pendingcnt--; 470 } 471 } 472 SIGSETNAND(sq->sq_signals, *set); 473 /* Finally, rescan queue and set pending bits for it */ 474 sigqueue_collect_set(sq, &sq->sq_signals); 475 } 476 477 void 478 sigqueue_delete(sigqueue_t *sq, int signo) 479 { 480 sigset_t set; 481 482 SIGEMPTYSET(set); 483 SIGADDSET(set, signo); 484 sigqueue_delete_set(sq, &set); 485 } 486 487 /* Remove a set of signals for a process */ 488 void 489 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 490 { 491 sigqueue_t worklist; 492 struct thread *td0; 493 494 PROC_LOCK_ASSERT(p, MA_OWNED); 495 496 sigqueue_init(&worklist, NULL); 497 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 498 499 mtx_lock_spin(&sched_lock); 500 FOREACH_THREAD_IN_PROC(p, td0) 501 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 502 mtx_unlock_spin(&sched_lock); 503 504 sigqueue_flush(&worklist); 505 } 506 507 void 508 sigqueue_delete_proc(struct proc *p, int signo) 509 { 510 sigset_t set; 511 512 SIGEMPTYSET(set); 513 SIGADDSET(set, signo); 514 sigqueue_delete_set_proc(p, &set); 515 } 516 517 void 518 sigqueue_delete_stopmask_proc(struct proc *p) 519 { 520 sigset_t set; 521 522 SIGEMPTYSET(set); 523 SIGADDSET(set, SIGSTOP); 524 SIGADDSET(set, SIGTSTP); 525 SIGADDSET(set, SIGTTIN); 526 SIGADDSET(set, SIGTTOU); 527 sigqueue_delete_set_proc(p, &set); 528 } 529 530 /* 531 * Determine signal that should be delivered to process p, the current 532 * process, 0 if none. If there is a pending stop signal with default 533 * action, the process stops in issignal(). 534 * 535 * MP SAFE. 536 */ 537 int 538 cursig(struct thread *td) 539 { 540 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 541 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 542 mtx_assert(&sched_lock, MA_NOTOWNED); 543 return (SIGPENDING(td) ? issignal(td) : 0); 544 } 545 546 /* 547 * Arrange for ast() to handle unmasked pending signals on return to user 548 * mode. This must be called whenever a signal is added to td_sigqueue or 549 * unmasked in td_sigmask. 550 */ 551 void 552 signotify(struct thread *td) 553 { 554 struct proc *p; 555 sigset_t set, saved; 556 557 p = td->td_proc; 558 559 PROC_LOCK_ASSERT(p, MA_OWNED); 560 561 /* 562 * If our mask changed we may have to move signal that were 563 * previously masked by all threads to our sigqueue. 564 */ 565 set = p->p_sigqueue.sq_signals; 566 if (p->p_flag & P_SA) 567 saved = p->p_sigqueue.sq_signals; 568 SIGSETNAND(set, td->td_sigmask); 569 if (! SIGISEMPTY(set)) 570 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set); 571 if (SIGPENDING(td)) { 572 mtx_lock_spin(&sched_lock); 573 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 574 mtx_unlock_spin(&sched_lock); 575 } 576 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 577 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 578 /* pending set changed */ 579 p->p_flag |= P_SIGEVENT; 580 wakeup(&p->p_siglist); 581 } 582 } 583 } 584 585 int 586 sigonstack(size_t sp) 587 { 588 struct thread *td = curthread; 589 590 return ((td->td_pflags & TDP_ALTSTACK) ? 591 #if defined(COMPAT_43) 592 ((td->td_sigstk.ss_size == 0) ? 593 (td->td_sigstk.ss_flags & SS_ONSTACK) : 594 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 595 #else 596 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 597 #endif 598 : 0); 599 } 600 601 static __inline int 602 sigprop(int sig) 603 { 604 605 if (sig > 0 && sig < NSIG) 606 return (sigproptbl[_SIG_IDX(sig)]); 607 return (0); 608 } 609 610 int 611 sig_ffs(sigset_t *set) 612 { 613 int i; 614 615 for (i = 0; i < _SIG_WORDS; i++) 616 if (set->__bits[i]) 617 return (ffs(set->__bits[i]) + (i * 32)); 618 return (0); 619 } 620 621 /* 622 * kern_sigaction 623 * sigaction 624 * freebsd4_sigaction 625 * osigaction 626 * 627 * MPSAFE 628 */ 629 int 630 kern_sigaction(td, sig, act, oact, flags) 631 struct thread *td; 632 register int sig; 633 struct sigaction *act, *oact; 634 int flags; 635 { 636 struct sigacts *ps; 637 struct proc *p = td->td_proc; 638 639 if (!_SIG_VALID(sig)) 640 return (EINVAL); 641 642 PROC_LOCK(p); 643 ps = p->p_sigacts; 644 mtx_lock(&ps->ps_mtx); 645 if (oact) { 646 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 647 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 648 oact->sa_flags = 0; 649 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 650 oact->sa_flags |= SA_ONSTACK; 651 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 652 oact->sa_flags |= SA_RESTART; 653 if (SIGISMEMBER(ps->ps_sigreset, sig)) 654 oact->sa_flags |= SA_RESETHAND; 655 if (SIGISMEMBER(ps->ps_signodefer, sig)) 656 oact->sa_flags |= SA_NODEFER; 657 if (SIGISMEMBER(ps->ps_siginfo, sig)) 658 oact->sa_flags |= SA_SIGINFO; 659 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 660 oact->sa_flags |= SA_NOCLDSTOP; 661 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 662 oact->sa_flags |= SA_NOCLDWAIT; 663 } 664 if (act) { 665 if ((sig == SIGKILL || sig == SIGSTOP) && 666 act->sa_handler != SIG_DFL) { 667 mtx_unlock(&ps->ps_mtx); 668 PROC_UNLOCK(p); 669 return (EINVAL); 670 } 671 672 /* 673 * Change setting atomically. 674 */ 675 676 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 677 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 678 if (act->sa_flags & SA_SIGINFO) { 679 ps->ps_sigact[_SIG_IDX(sig)] = 680 (__sighandler_t *)act->sa_sigaction; 681 SIGADDSET(ps->ps_siginfo, sig); 682 } else { 683 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 684 SIGDELSET(ps->ps_siginfo, sig); 685 } 686 if (!(act->sa_flags & SA_RESTART)) 687 SIGADDSET(ps->ps_sigintr, sig); 688 else 689 SIGDELSET(ps->ps_sigintr, sig); 690 if (act->sa_flags & SA_ONSTACK) 691 SIGADDSET(ps->ps_sigonstack, sig); 692 else 693 SIGDELSET(ps->ps_sigonstack, sig); 694 if (act->sa_flags & SA_RESETHAND) 695 SIGADDSET(ps->ps_sigreset, sig); 696 else 697 SIGDELSET(ps->ps_sigreset, sig); 698 if (act->sa_flags & SA_NODEFER) 699 SIGADDSET(ps->ps_signodefer, sig); 700 else 701 SIGDELSET(ps->ps_signodefer, sig); 702 if (sig == SIGCHLD) { 703 if (act->sa_flags & SA_NOCLDSTOP) 704 ps->ps_flag |= PS_NOCLDSTOP; 705 else 706 ps->ps_flag &= ~PS_NOCLDSTOP; 707 if (act->sa_flags & SA_NOCLDWAIT) { 708 /* 709 * Paranoia: since SA_NOCLDWAIT is implemented 710 * by reparenting the dying child to PID 1 (and 711 * trust it to reap the zombie), PID 1 itself 712 * is forbidden to set SA_NOCLDWAIT. 713 */ 714 if (p->p_pid == 1) 715 ps->ps_flag &= ~PS_NOCLDWAIT; 716 else 717 ps->ps_flag |= PS_NOCLDWAIT; 718 } else 719 ps->ps_flag &= ~PS_NOCLDWAIT; 720 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 721 ps->ps_flag |= PS_CLDSIGIGN; 722 else 723 ps->ps_flag &= ~PS_CLDSIGIGN; 724 } 725 /* 726 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 727 * and for signals set to SIG_DFL where the default is to 728 * ignore. However, don't put SIGCONT in ps_sigignore, as we 729 * have to restart the process. 730 */ 731 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 732 (sigprop(sig) & SA_IGNORE && 733 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 734 if ((p->p_flag & P_SA) && 735 SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) { 736 p->p_flag |= P_SIGEVENT; 737 wakeup(&p->p_siglist); 738 } 739 /* never to be seen again */ 740 sigqueue_delete_proc(p, sig); 741 if (sig != SIGCONT) 742 /* easier in psignal */ 743 SIGADDSET(ps->ps_sigignore, sig); 744 SIGDELSET(ps->ps_sigcatch, sig); 745 } else { 746 SIGDELSET(ps->ps_sigignore, sig); 747 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 748 SIGDELSET(ps->ps_sigcatch, sig); 749 else 750 SIGADDSET(ps->ps_sigcatch, sig); 751 } 752 #ifdef COMPAT_FREEBSD4 753 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 754 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 755 (flags & KSA_FREEBSD4) == 0) 756 SIGDELSET(ps->ps_freebsd4, sig); 757 else 758 SIGADDSET(ps->ps_freebsd4, sig); 759 #endif 760 #ifdef COMPAT_43 761 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 762 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 763 (flags & KSA_OSIGSET) == 0) 764 SIGDELSET(ps->ps_osigset, sig); 765 else 766 SIGADDSET(ps->ps_osigset, sig); 767 #endif 768 } 769 mtx_unlock(&ps->ps_mtx); 770 PROC_UNLOCK(p); 771 return (0); 772 } 773 774 #ifndef _SYS_SYSPROTO_H_ 775 struct sigaction_args { 776 int sig; 777 struct sigaction *act; 778 struct sigaction *oact; 779 }; 780 #endif 781 /* 782 * MPSAFE 783 */ 784 int 785 sigaction(td, uap) 786 struct thread *td; 787 register struct sigaction_args *uap; 788 { 789 struct sigaction act, oact; 790 register struct sigaction *actp, *oactp; 791 int error; 792 793 actp = (uap->act != NULL) ? &act : NULL; 794 oactp = (uap->oact != NULL) ? &oact : NULL; 795 if (actp) { 796 error = copyin(uap->act, actp, sizeof(act)); 797 if (error) 798 return (error); 799 } 800 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 801 if (oactp && !error) 802 error = copyout(oactp, uap->oact, sizeof(oact)); 803 return (error); 804 } 805 806 #ifdef COMPAT_FREEBSD4 807 #ifndef _SYS_SYSPROTO_H_ 808 struct freebsd4_sigaction_args { 809 int sig; 810 struct sigaction *act; 811 struct sigaction *oact; 812 }; 813 #endif 814 /* 815 * MPSAFE 816 */ 817 int 818 freebsd4_sigaction(td, uap) 819 struct thread *td; 820 register struct freebsd4_sigaction_args *uap; 821 { 822 struct sigaction act, oact; 823 register struct sigaction *actp, *oactp; 824 int error; 825 826 827 actp = (uap->act != NULL) ? &act : NULL; 828 oactp = (uap->oact != NULL) ? &oact : NULL; 829 if (actp) { 830 error = copyin(uap->act, actp, sizeof(act)); 831 if (error) 832 return (error); 833 } 834 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 835 if (oactp && !error) 836 error = copyout(oactp, uap->oact, sizeof(oact)); 837 return (error); 838 } 839 #endif /* COMAPT_FREEBSD4 */ 840 841 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 842 #ifndef _SYS_SYSPROTO_H_ 843 struct osigaction_args { 844 int signum; 845 struct osigaction *nsa; 846 struct osigaction *osa; 847 }; 848 #endif 849 /* 850 * MPSAFE 851 */ 852 int 853 osigaction(td, uap) 854 struct thread *td; 855 register struct osigaction_args *uap; 856 { 857 struct osigaction sa; 858 struct sigaction nsa, osa; 859 register struct sigaction *nsap, *osap; 860 int error; 861 862 if (uap->signum <= 0 || uap->signum >= ONSIG) 863 return (EINVAL); 864 865 nsap = (uap->nsa != NULL) ? &nsa : NULL; 866 osap = (uap->osa != NULL) ? &osa : NULL; 867 868 if (nsap) { 869 error = copyin(uap->nsa, &sa, sizeof(sa)); 870 if (error) 871 return (error); 872 nsap->sa_handler = sa.sa_handler; 873 nsap->sa_flags = sa.sa_flags; 874 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 875 } 876 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 877 if (osap && !error) { 878 sa.sa_handler = osap->sa_handler; 879 sa.sa_flags = osap->sa_flags; 880 SIG2OSIG(osap->sa_mask, sa.sa_mask); 881 error = copyout(&sa, uap->osa, sizeof(sa)); 882 } 883 return (error); 884 } 885 886 #if !defined(__i386__) && !defined(__alpha__) 887 /* Avoid replicating the same stub everywhere */ 888 int 889 osigreturn(td, uap) 890 struct thread *td; 891 struct osigreturn_args *uap; 892 { 893 894 return (nosys(td, (struct nosys_args *)uap)); 895 } 896 #endif 897 #endif /* COMPAT_43 */ 898 899 /* 900 * Initialize signal state for process 0; 901 * set to ignore signals that are ignored by default. 902 */ 903 void 904 siginit(p) 905 struct proc *p; 906 { 907 register int i; 908 struct sigacts *ps; 909 910 PROC_LOCK(p); 911 ps = p->p_sigacts; 912 mtx_lock(&ps->ps_mtx); 913 for (i = 1; i <= NSIG; i++) 914 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 915 SIGADDSET(ps->ps_sigignore, i); 916 mtx_unlock(&ps->ps_mtx); 917 PROC_UNLOCK(p); 918 } 919 920 /* 921 * Reset signals for an exec of the specified process. 922 */ 923 void 924 execsigs(struct proc *p) 925 { 926 struct sigacts *ps; 927 int sig; 928 struct thread *td; 929 930 /* 931 * Reset caught signals. Held signals remain held 932 * through td_sigmask (unless they were caught, 933 * and are now ignored by default). 934 */ 935 PROC_LOCK_ASSERT(p, MA_OWNED); 936 td = FIRST_THREAD_IN_PROC(p); 937 ps = p->p_sigacts; 938 mtx_lock(&ps->ps_mtx); 939 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 940 sig = sig_ffs(&ps->ps_sigcatch); 941 SIGDELSET(ps->ps_sigcatch, sig); 942 if (sigprop(sig) & SA_IGNORE) { 943 if (sig != SIGCONT) 944 SIGADDSET(ps->ps_sigignore, sig); 945 sigqueue_delete_proc(p, sig); 946 } 947 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 948 } 949 /* 950 * Reset stack state to the user stack. 951 * Clear set of signals caught on the signal stack. 952 */ 953 td->td_sigstk.ss_flags = SS_DISABLE; 954 td->td_sigstk.ss_size = 0; 955 td->td_sigstk.ss_sp = 0; 956 td->td_pflags &= ~TDP_ALTSTACK; 957 /* 958 * Reset no zombies if child dies flag as Solaris does. 959 */ 960 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 961 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 962 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 963 mtx_unlock(&ps->ps_mtx); 964 } 965 966 /* 967 * kern_sigprocmask() 968 * 969 * Manipulate signal mask. 970 */ 971 int 972 kern_sigprocmask(td, how, set, oset, old) 973 struct thread *td; 974 int how; 975 sigset_t *set, *oset; 976 int old; 977 { 978 int error; 979 980 PROC_LOCK(td->td_proc); 981 if (oset != NULL) 982 *oset = td->td_sigmask; 983 984 error = 0; 985 if (set != NULL) { 986 switch (how) { 987 case SIG_BLOCK: 988 SIG_CANTMASK(*set); 989 SIGSETOR(td->td_sigmask, *set); 990 break; 991 case SIG_UNBLOCK: 992 SIGSETNAND(td->td_sigmask, *set); 993 signotify(td); 994 break; 995 case SIG_SETMASK: 996 SIG_CANTMASK(*set); 997 if (old) 998 SIGSETLO(td->td_sigmask, *set); 999 else 1000 td->td_sigmask = *set; 1001 signotify(td); 1002 break; 1003 default: 1004 error = EINVAL; 1005 break; 1006 } 1007 } 1008 PROC_UNLOCK(td->td_proc); 1009 return (error); 1010 } 1011 1012 /* 1013 * sigprocmask() - MP SAFE 1014 */ 1015 1016 #ifndef _SYS_SYSPROTO_H_ 1017 struct sigprocmask_args { 1018 int how; 1019 const sigset_t *set; 1020 sigset_t *oset; 1021 }; 1022 #endif 1023 int 1024 sigprocmask(td, uap) 1025 register struct thread *td; 1026 struct sigprocmask_args *uap; 1027 { 1028 sigset_t set, oset; 1029 sigset_t *setp, *osetp; 1030 int error; 1031 1032 setp = (uap->set != NULL) ? &set : NULL; 1033 osetp = (uap->oset != NULL) ? &oset : NULL; 1034 if (setp) { 1035 error = copyin(uap->set, setp, sizeof(set)); 1036 if (error) 1037 return (error); 1038 } 1039 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1040 if (osetp && !error) { 1041 error = copyout(osetp, uap->oset, sizeof(oset)); 1042 } 1043 return (error); 1044 } 1045 1046 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1047 /* 1048 * osigprocmask() - MP SAFE 1049 */ 1050 #ifndef _SYS_SYSPROTO_H_ 1051 struct osigprocmask_args { 1052 int how; 1053 osigset_t mask; 1054 }; 1055 #endif 1056 int 1057 osigprocmask(td, uap) 1058 register struct thread *td; 1059 struct osigprocmask_args *uap; 1060 { 1061 sigset_t set, oset; 1062 int error; 1063 1064 OSIG2SIG(uap->mask, set); 1065 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1066 SIG2OSIG(oset, td->td_retval[0]); 1067 return (error); 1068 } 1069 #endif /* COMPAT_43 */ 1070 1071 /* 1072 * MPSAFE 1073 */ 1074 int 1075 sigwait(struct thread *td, struct sigwait_args *uap) 1076 { 1077 ksiginfo_t ksi; 1078 sigset_t set; 1079 int error; 1080 1081 error = copyin(uap->set, &set, sizeof(set)); 1082 if (error) { 1083 td->td_retval[0] = error; 1084 return (0); 1085 } 1086 1087 error = kern_sigtimedwait(td, set, &ksi, NULL); 1088 if (error) { 1089 if (error == ERESTART) 1090 return (error); 1091 td->td_retval[0] = error; 1092 return (0); 1093 } 1094 1095 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1096 td->td_retval[0] = error; 1097 return (0); 1098 } 1099 /* 1100 * MPSAFE 1101 */ 1102 int 1103 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1104 { 1105 struct timespec ts; 1106 struct timespec *timeout; 1107 sigset_t set; 1108 ksiginfo_t ksi; 1109 int error; 1110 1111 if (uap->timeout) { 1112 error = copyin(uap->timeout, &ts, sizeof(ts)); 1113 if (error) 1114 return (error); 1115 1116 timeout = &ts; 1117 } else 1118 timeout = NULL; 1119 1120 error = copyin(uap->set, &set, sizeof(set)); 1121 if (error) 1122 return (error); 1123 1124 error = kern_sigtimedwait(td, set, &ksi, timeout); 1125 if (error) 1126 return (error); 1127 1128 if (uap->info) 1129 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1130 1131 if (error == 0) 1132 td->td_retval[0] = ksi.ksi_signo; 1133 return (error); 1134 } 1135 1136 /* 1137 * MPSAFE 1138 */ 1139 int 1140 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1141 { 1142 ksiginfo_t ksi; 1143 sigset_t set; 1144 int error; 1145 1146 error = copyin(uap->set, &set, sizeof(set)); 1147 if (error) 1148 return (error); 1149 1150 error = kern_sigtimedwait(td, set, &ksi, NULL); 1151 if (error) 1152 return (error); 1153 1154 if (uap->info) 1155 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1156 1157 if (error == 0) 1158 td->td_retval[0] = ksi.ksi_signo; 1159 return (error); 1160 } 1161 1162 static int 1163 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1164 struct timespec *timeout) 1165 { 1166 struct sigacts *ps; 1167 sigset_t savedmask; 1168 struct proc *p; 1169 int error, sig, hz, i, timevalid = 0; 1170 struct timespec rts, ets, ts; 1171 struct timeval tv; 1172 1173 p = td->td_proc; 1174 error = 0; 1175 sig = 0; 1176 SIG_CANTMASK(waitset); 1177 1178 PROC_LOCK(p); 1179 ps = p->p_sigacts; 1180 savedmask = td->td_sigmask; 1181 if (timeout) { 1182 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1183 timevalid = 1; 1184 getnanouptime(&rts); 1185 ets = rts; 1186 timespecadd(&ets, timeout); 1187 } 1188 } 1189 1190 again: 1191 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1192 if (!SIGISMEMBER(waitset, i)) 1193 continue; 1194 if (SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1195 SIGFILLSET(td->td_sigmask); 1196 SIG_CANTMASK(td->td_sigmask); 1197 SIGDELSET(td->td_sigmask, i); 1198 mtx_lock(&ps->ps_mtx); 1199 sig = cursig(td); 1200 i = 0; 1201 mtx_unlock(&ps->ps_mtx); 1202 } else if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1203 if (p->p_flag & P_SA) { 1204 p->p_flag |= P_SIGEVENT; 1205 wakeup(&p->p_siglist); 1206 } 1207 sigqueue_move(&p->p_sigqueue, &td->td_sigqueue, i); 1208 SIGFILLSET(td->td_sigmask); 1209 SIG_CANTMASK(td->td_sigmask); 1210 SIGDELSET(td->td_sigmask, i); 1211 mtx_lock(&ps->ps_mtx); 1212 sig = cursig(td); 1213 i = 0; 1214 mtx_unlock(&ps->ps_mtx); 1215 } 1216 if (sig) 1217 goto out; 1218 } 1219 if (error) 1220 goto out; 1221 1222 /* 1223 * POSIX says this must be checked after looking for pending 1224 * signals. 1225 */ 1226 if (timeout) { 1227 if (!timevalid) { 1228 error = EINVAL; 1229 goto out; 1230 } 1231 getnanouptime(&rts); 1232 if (timespeccmp(&rts, &ets, >=)) { 1233 error = EAGAIN; 1234 goto out; 1235 } 1236 ts = ets; 1237 timespecsub(&ts, &rts); 1238 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1239 hz = tvtohz(&tv); 1240 } else 1241 hz = 0; 1242 1243 td->td_sigmask = savedmask; 1244 SIGSETNAND(td->td_sigmask, waitset); 1245 signotify(td); 1246 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1247 if (timeout) { 1248 if (error == ERESTART) { 1249 /* timeout can not be restarted. */ 1250 error = EINTR; 1251 } else if (error == EAGAIN) { 1252 /* will calculate timeout by ourself. */ 1253 error = 0; 1254 } 1255 } 1256 goto again; 1257 1258 out: 1259 if (sig) { 1260 sig_t action; 1261 1262 ksiginfo_init(ksi); 1263 sigqueue_get(&td->td_sigqueue, sig, ksi); 1264 ksi->ksi_signo = sig; 1265 if (ksi->ksi_code == SI_TIMER) 1266 itimer_accept(p, ksi->ksi_timerid, ksi); 1267 error = 0; 1268 mtx_lock(&ps->ps_mtx); 1269 action = ps->ps_sigact[_SIG_IDX(sig)]; 1270 mtx_unlock(&ps->ps_mtx); 1271 #ifdef KTRACE 1272 if (KTRPOINT(td, KTR_PSIG)) 1273 ktrpsig(sig, action, &td->td_sigmask, 0); 1274 #endif 1275 _STOPEVENT(p, S_SIG, sig); 1276 1277 } 1278 td->td_sigmask = savedmask; 1279 signotify(td); 1280 PROC_UNLOCK(p); 1281 return (error); 1282 } 1283 1284 #ifndef _SYS_SYSPROTO_H_ 1285 struct sigpending_args { 1286 sigset_t *set; 1287 }; 1288 #endif 1289 /* 1290 * MPSAFE 1291 */ 1292 int 1293 sigpending(td, uap) 1294 struct thread *td; 1295 struct sigpending_args *uap; 1296 { 1297 struct proc *p = td->td_proc; 1298 sigset_t pending; 1299 1300 PROC_LOCK(p); 1301 pending = p->p_sigqueue.sq_signals; 1302 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1303 PROC_UNLOCK(p); 1304 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1305 } 1306 1307 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1308 #ifndef _SYS_SYSPROTO_H_ 1309 struct osigpending_args { 1310 int dummy; 1311 }; 1312 #endif 1313 /* 1314 * MPSAFE 1315 */ 1316 int 1317 osigpending(td, uap) 1318 struct thread *td; 1319 struct osigpending_args *uap; 1320 { 1321 struct proc *p = td->td_proc; 1322 sigset_t pending; 1323 1324 PROC_LOCK(p); 1325 pending = p->p_sigqueue.sq_signals; 1326 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1327 PROC_UNLOCK(p); 1328 SIG2OSIG(pending, td->td_retval[0]); 1329 return (0); 1330 } 1331 #endif /* COMPAT_43 */ 1332 1333 #if defined(COMPAT_43) 1334 /* 1335 * Generalized interface signal handler, 4.3-compatible. 1336 */ 1337 #ifndef _SYS_SYSPROTO_H_ 1338 struct osigvec_args { 1339 int signum; 1340 struct sigvec *nsv; 1341 struct sigvec *osv; 1342 }; 1343 #endif 1344 /* 1345 * MPSAFE 1346 */ 1347 /* ARGSUSED */ 1348 int 1349 osigvec(td, uap) 1350 struct thread *td; 1351 register struct osigvec_args *uap; 1352 { 1353 struct sigvec vec; 1354 struct sigaction nsa, osa; 1355 register struct sigaction *nsap, *osap; 1356 int error; 1357 1358 if (uap->signum <= 0 || uap->signum >= ONSIG) 1359 return (EINVAL); 1360 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1361 osap = (uap->osv != NULL) ? &osa : NULL; 1362 if (nsap) { 1363 error = copyin(uap->nsv, &vec, sizeof(vec)); 1364 if (error) 1365 return (error); 1366 nsap->sa_handler = vec.sv_handler; 1367 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1368 nsap->sa_flags = vec.sv_flags; 1369 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1370 } 1371 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1372 if (osap && !error) { 1373 vec.sv_handler = osap->sa_handler; 1374 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1375 vec.sv_flags = osap->sa_flags; 1376 vec.sv_flags &= ~SA_NOCLDWAIT; 1377 vec.sv_flags ^= SA_RESTART; 1378 error = copyout(&vec, uap->osv, sizeof(vec)); 1379 } 1380 return (error); 1381 } 1382 1383 #ifndef _SYS_SYSPROTO_H_ 1384 struct osigblock_args { 1385 int mask; 1386 }; 1387 #endif 1388 /* 1389 * MPSAFE 1390 */ 1391 int 1392 osigblock(td, uap) 1393 register struct thread *td; 1394 struct osigblock_args *uap; 1395 { 1396 struct proc *p = td->td_proc; 1397 sigset_t set; 1398 1399 OSIG2SIG(uap->mask, set); 1400 SIG_CANTMASK(set); 1401 PROC_LOCK(p); 1402 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1403 SIGSETOR(td->td_sigmask, set); 1404 PROC_UNLOCK(p); 1405 return (0); 1406 } 1407 1408 #ifndef _SYS_SYSPROTO_H_ 1409 struct osigsetmask_args { 1410 int mask; 1411 }; 1412 #endif 1413 /* 1414 * MPSAFE 1415 */ 1416 int 1417 osigsetmask(td, uap) 1418 struct thread *td; 1419 struct osigsetmask_args *uap; 1420 { 1421 struct proc *p = td->td_proc; 1422 sigset_t set; 1423 1424 OSIG2SIG(uap->mask, set); 1425 SIG_CANTMASK(set); 1426 PROC_LOCK(p); 1427 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1428 SIGSETLO(td->td_sigmask, set); 1429 signotify(td); 1430 PROC_UNLOCK(p); 1431 return (0); 1432 } 1433 #endif /* COMPAT_43 */ 1434 1435 /* 1436 * Suspend calling thread until signal, providing mask to be set 1437 * in the meantime. 1438 */ 1439 #ifndef _SYS_SYSPROTO_H_ 1440 struct sigsuspend_args { 1441 const sigset_t *sigmask; 1442 }; 1443 #endif 1444 /* 1445 * MPSAFE 1446 */ 1447 /* ARGSUSED */ 1448 int 1449 sigsuspend(td, uap) 1450 struct thread *td; 1451 struct sigsuspend_args *uap; 1452 { 1453 sigset_t mask; 1454 int error; 1455 1456 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1457 if (error) 1458 return (error); 1459 return (kern_sigsuspend(td, mask)); 1460 } 1461 1462 int 1463 kern_sigsuspend(struct thread *td, sigset_t mask) 1464 { 1465 struct proc *p = td->td_proc; 1466 1467 /* 1468 * When returning from sigsuspend, we want 1469 * the old mask to be restored after the 1470 * signal handler has finished. Thus, we 1471 * save it here and mark the sigacts structure 1472 * to indicate this. 1473 */ 1474 PROC_LOCK(p); 1475 td->td_oldsigmask = td->td_sigmask; 1476 td->td_pflags |= TDP_OLDMASK; 1477 SIG_CANTMASK(mask); 1478 td->td_sigmask = mask; 1479 signotify(td); 1480 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1481 /* void */; 1482 PROC_UNLOCK(p); 1483 /* always return EINTR rather than ERESTART... */ 1484 return (EINTR); 1485 } 1486 1487 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1488 /* 1489 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1490 * convention: libc stub passes mask, not pointer, to save a copyin. 1491 */ 1492 #ifndef _SYS_SYSPROTO_H_ 1493 struct osigsuspend_args { 1494 osigset_t mask; 1495 }; 1496 #endif 1497 /* 1498 * MPSAFE 1499 */ 1500 /* ARGSUSED */ 1501 int 1502 osigsuspend(td, uap) 1503 struct thread *td; 1504 struct osigsuspend_args *uap; 1505 { 1506 struct proc *p = td->td_proc; 1507 sigset_t mask; 1508 1509 PROC_LOCK(p); 1510 td->td_oldsigmask = td->td_sigmask; 1511 td->td_pflags |= TDP_OLDMASK; 1512 OSIG2SIG(uap->mask, mask); 1513 SIG_CANTMASK(mask); 1514 SIGSETLO(td->td_sigmask, mask); 1515 signotify(td); 1516 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1517 /* void */; 1518 PROC_UNLOCK(p); 1519 /* always return EINTR rather than ERESTART... */ 1520 return (EINTR); 1521 } 1522 #endif /* COMPAT_43 */ 1523 1524 #if defined(COMPAT_43) 1525 #ifndef _SYS_SYSPROTO_H_ 1526 struct osigstack_args { 1527 struct sigstack *nss; 1528 struct sigstack *oss; 1529 }; 1530 #endif 1531 /* 1532 * MPSAFE 1533 */ 1534 /* ARGSUSED */ 1535 int 1536 osigstack(td, uap) 1537 struct thread *td; 1538 register struct osigstack_args *uap; 1539 { 1540 struct sigstack nss, oss; 1541 int error = 0; 1542 1543 if (uap->nss != NULL) { 1544 error = copyin(uap->nss, &nss, sizeof(nss)); 1545 if (error) 1546 return (error); 1547 } 1548 oss.ss_sp = td->td_sigstk.ss_sp; 1549 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1550 if (uap->nss != NULL) { 1551 td->td_sigstk.ss_sp = nss.ss_sp; 1552 td->td_sigstk.ss_size = 0; 1553 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1554 td->td_pflags |= TDP_ALTSTACK; 1555 } 1556 if (uap->oss != NULL) 1557 error = copyout(&oss, uap->oss, sizeof(oss)); 1558 1559 return (error); 1560 } 1561 #endif /* COMPAT_43 */ 1562 1563 #ifndef _SYS_SYSPROTO_H_ 1564 struct sigaltstack_args { 1565 stack_t *ss; 1566 stack_t *oss; 1567 }; 1568 #endif 1569 /* 1570 * MPSAFE 1571 */ 1572 /* ARGSUSED */ 1573 int 1574 sigaltstack(td, uap) 1575 struct thread *td; 1576 register struct sigaltstack_args *uap; 1577 { 1578 stack_t ss, oss; 1579 int error; 1580 1581 if (uap->ss != NULL) { 1582 error = copyin(uap->ss, &ss, sizeof(ss)); 1583 if (error) 1584 return (error); 1585 } 1586 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1587 (uap->oss != NULL) ? &oss : NULL); 1588 if (error) 1589 return (error); 1590 if (uap->oss != NULL) 1591 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1592 return (error); 1593 } 1594 1595 int 1596 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1597 { 1598 struct proc *p = td->td_proc; 1599 int oonstack; 1600 1601 oonstack = sigonstack(cpu_getstack(td)); 1602 1603 if (oss != NULL) { 1604 *oss = td->td_sigstk; 1605 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1606 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1607 } 1608 1609 if (ss != NULL) { 1610 if (oonstack) 1611 return (EPERM); 1612 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1613 return (EINVAL); 1614 if (!(ss->ss_flags & SS_DISABLE)) { 1615 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1616 return (ENOMEM); 1617 1618 td->td_sigstk = *ss; 1619 td->td_pflags |= TDP_ALTSTACK; 1620 } else { 1621 td->td_pflags &= ~TDP_ALTSTACK; 1622 } 1623 } 1624 return (0); 1625 } 1626 1627 /* 1628 * Common code for kill process group/broadcast kill. 1629 * cp is calling process. 1630 */ 1631 static int 1632 killpg1(td, sig, pgid, all) 1633 register struct thread *td; 1634 int sig, pgid, all; 1635 { 1636 register struct proc *p; 1637 struct pgrp *pgrp; 1638 int nfound = 0; 1639 1640 if (all) { 1641 /* 1642 * broadcast 1643 */ 1644 sx_slock(&allproc_lock); 1645 LIST_FOREACH(p, &allproc, p_list) { 1646 PROC_LOCK(p); 1647 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1648 p == td->td_proc) { 1649 PROC_UNLOCK(p); 1650 continue; 1651 } 1652 if (p_cansignal(td, p, sig) == 0) { 1653 nfound++; 1654 if (sig) 1655 psignal(p, sig); 1656 } 1657 PROC_UNLOCK(p); 1658 } 1659 sx_sunlock(&allproc_lock); 1660 } else { 1661 sx_slock(&proctree_lock); 1662 if (pgid == 0) { 1663 /* 1664 * zero pgid means send to my process group. 1665 */ 1666 pgrp = td->td_proc->p_pgrp; 1667 PGRP_LOCK(pgrp); 1668 } else { 1669 pgrp = pgfind(pgid); 1670 if (pgrp == NULL) { 1671 sx_sunlock(&proctree_lock); 1672 return (ESRCH); 1673 } 1674 } 1675 sx_sunlock(&proctree_lock); 1676 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1677 PROC_LOCK(p); 1678 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1679 PROC_UNLOCK(p); 1680 continue; 1681 } 1682 if (p_cansignal(td, p, sig) == 0) { 1683 nfound++; 1684 if (sig) 1685 psignal(p, sig); 1686 } 1687 PROC_UNLOCK(p); 1688 } 1689 PGRP_UNLOCK(pgrp); 1690 } 1691 return (nfound ? 0 : ESRCH); 1692 } 1693 1694 #ifndef _SYS_SYSPROTO_H_ 1695 struct kill_args { 1696 int pid; 1697 int signum; 1698 }; 1699 #endif 1700 /* 1701 * MPSAFE 1702 */ 1703 /* ARGSUSED */ 1704 int 1705 kill(td, uap) 1706 register struct thread *td; 1707 register struct kill_args *uap; 1708 { 1709 register struct proc *p; 1710 int error; 1711 1712 if ((u_int)uap->signum > _SIG_MAXSIG) 1713 return (EINVAL); 1714 1715 if (uap->pid > 0) { 1716 /* kill single process */ 1717 if ((p = pfind(uap->pid)) == NULL) { 1718 if ((p = zpfind(uap->pid)) == NULL) 1719 return (ESRCH); 1720 } 1721 error = p_cansignal(td, p, uap->signum); 1722 if (error == 0 && uap->signum) 1723 psignal(p, uap->signum); 1724 PROC_UNLOCK(p); 1725 return (error); 1726 } 1727 switch (uap->pid) { 1728 case -1: /* broadcast signal */ 1729 return (killpg1(td, uap->signum, 0, 1)); 1730 case 0: /* signal own process group */ 1731 return (killpg1(td, uap->signum, 0, 0)); 1732 default: /* negative explicit process group */ 1733 return (killpg1(td, uap->signum, -uap->pid, 0)); 1734 } 1735 /* NOTREACHED */ 1736 } 1737 1738 #if defined(COMPAT_43) 1739 #ifndef _SYS_SYSPROTO_H_ 1740 struct okillpg_args { 1741 int pgid; 1742 int signum; 1743 }; 1744 #endif 1745 /* 1746 * MPSAFE 1747 */ 1748 /* ARGSUSED */ 1749 int 1750 okillpg(td, uap) 1751 struct thread *td; 1752 register struct okillpg_args *uap; 1753 { 1754 1755 if ((u_int)uap->signum > _SIG_MAXSIG) 1756 return (EINVAL); 1757 1758 return (killpg1(td, uap->signum, uap->pgid, 0)); 1759 } 1760 #endif /* COMPAT_43 */ 1761 1762 #ifndef _SYS_SYSPROTO_H_ 1763 struct sigqueue_args { 1764 pid_t pid; 1765 int signum; 1766 /* union sigval */ void *value; 1767 }; 1768 #endif 1769 1770 int 1771 sigqueue(struct thread *td, struct sigqueue_args *uap) 1772 { 1773 ksiginfo_t ksi; 1774 struct proc *p; 1775 int error; 1776 1777 if ((u_int)uap->signum > _SIG_MAXSIG) 1778 return (EINVAL); 1779 1780 /* 1781 * Specification says sigqueue can only send signal to 1782 * single process. 1783 */ 1784 if (uap->pid <= 0) 1785 return (EINVAL); 1786 1787 if ((p = pfind(uap->pid)) == NULL) { 1788 if ((p = zpfind(uap->pid)) == NULL) 1789 return (ESRCH); 1790 } 1791 error = p_cansignal(td, p, uap->signum); 1792 if (error == 0 && uap->signum != 0) { 1793 ksiginfo_init(&ksi); 1794 ksi.ksi_signo = uap->signum; 1795 ksi.ksi_code = SI_QUEUE; 1796 ksi.ksi_pid = td->td_proc->p_pid; 1797 ksi.ksi_uid = td->td_ucred->cr_ruid; 1798 ksi.ksi_value.sival_ptr = uap->value; 1799 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1800 } 1801 PROC_UNLOCK(p); 1802 return (error); 1803 } 1804 1805 /* 1806 * Send a signal to a process group. 1807 */ 1808 void 1809 gsignal(pgid, sig) 1810 int pgid, sig; 1811 { 1812 struct pgrp *pgrp; 1813 1814 if (pgid != 0) { 1815 sx_slock(&proctree_lock); 1816 pgrp = pgfind(pgid); 1817 sx_sunlock(&proctree_lock); 1818 if (pgrp != NULL) { 1819 pgsignal(pgrp, sig, 0); 1820 PGRP_UNLOCK(pgrp); 1821 } 1822 } 1823 } 1824 1825 /* 1826 * Send a signal to a process group. If checktty is 1, 1827 * limit to members which have a controlling terminal. 1828 */ 1829 void 1830 pgsignal(pgrp, sig, checkctty) 1831 struct pgrp *pgrp; 1832 int sig, checkctty; 1833 { 1834 register struct proc *p; 1835 1836 if (pgrp) { 1837 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1838 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1839 PROC_LOCK(p); 1840 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1841 psignal(p, sig); 1842 PROC_UNLOCK(p); 1843 } 1844 } 1845 } 1846 1847 /* 1848 * Send a signal caused by a trap to the current thread. 1849 * If it will be caught immediately, deliver it with correct code. 1850 * Otherwise, post it normally. 1851 * 1852 * MPSAFE 1853 */ 1854 void 1855 trapsignal(struct thread *td, ksiginfo_t *ksi) 1856 { 1857 struct sigacts *ps; 1858 struct proc *p; 1859 int error; 1860 int sig; 1861 int code; 1862 1863 p = td->td_proc; 1864 sig = ksi->ksi_signo; 1865 code = ksi->ksi_code; 1866 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1867 1868 if (td->td_pflags & TDP_SA) { 1869 if (td->td_mailbox == NULL) 1870 thread_user_enter(td); 1871 PROC_LOCK(p); 1872 SIGDELSET(td->td_sigmask, sig); 1873 mtx_lock_spin(&sched_lock); 1874 /* 1875 * Force scheduling an upcall, so UTS has chance to 1876 * process the signal before thread runs again in 1877 * userland. 1878 */ 1879 if (td->td_upcall) 1880 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1881 mtx_unlock_spin(&sched_lock); 1882 } else { 1883 PROC_LOCK(p); 1884 } 1885 ps = p->p_sigacts; 1886 mtx_lock(&ps->ps_mtx); 1887 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1888 !SIGISMEMBER(td->td_sigmask, sig)) { 1889 p->p_stats->p_ru.ru_nsignals++; 1890 #ifdef KTRACE 1891 if (KTRPOINT(curthread, KTR_PSIG)) 1892 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1893 &td->td_sigmask, code); 1894 #endif 1895 if (!(td->td_pflags & TDP_SA)) 1896 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1897 ksi, &td->td_sigmask); 1898 else if (td->td_mailbox == NULL) { 1899 mtx_unlock(&ps->ps_mtx); 1900 /* UTS caused a sync signal */ 1901 p->p_code = code; /* XXX for core dump/debugger */ 1902 p->p_sig = sig; /* XXX to verify code */ 1903 sigexit(td, sig); 1904 } else { 1905 mtx_unlock(&ps->ps_mtx); 1906 SIGADDSET(td->td_sigmask, sig); 1907 PROC_UNLOCK(p); 1908 error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig, 1909 sizeof(siginfo_t)); 1910 PROC_LOCK(p); 1911 /* UTS memory corrupted */ 1912 if (error) 1913 sigexit(td, SIGSEGV); 1914 mtx_lock(&ps->ps_mtx); 1915 } 1916 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1917 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1918 SIGADDSET(td->td_sigmask, sig); 1919 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1920 /* 1921 * See kern_sigaction() for origin of this code. 1922 */ 1923 SIGDELSET(ps->ps_sigcatch, sig); 1924 if (sig != SIGCONT && 1925 sigprop(sig) & SA_IGNORE) 1926 SIGADDSET(ps->ps_sigignore, sig); 1927 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1928 } 1929 mtx_unlock(&ps->ps_mtx); 1930 } else { 1931 /* 1932 * Avoid a possible infinite loop if the thread 1933 * masking the signal or process is ignoring the 1934 * signal. 1935 */ 1936 if (kern_forcesigexit && 1937 (SIGISMEMBER(td->td_sigmask, sig) || 1938 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1939 SIGDELSET(td->td_sigmask, sig); 1940 SIGDELSET(ps->ps_sigcatch, sig); 1941 SIGDELSET(ps->ps_sigignore, sig); 1942 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1943 } 1944 mtx_unlock(&ps->ps_mtx); 1945 p->p_code = code; /* XXX for core dump/debugger */ 1946 p->p_sig = sig; /* XXX to verify code */ 1947 tdsignal(p, td, sig, ksi); 1948 } 1949 PROC_UNLOCK(p); 1950 } 1951 1952 static struct thread * 1953 sigtd(struct proc *p, int sig, int prop) 1954 { 1955 struct thread *td, *signal_td; 1956 1957 PROC_LOCK_ASSERT(p, MA_OWNED); 1958 1959 /* 1960 * Check if current thread can handle the signal without 1961 * switching conetxt to another thread. 1962 */ 1963 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1964 return (curthread); 1965 signal_td = NULL; 1966 mtx_lock_spin(&sched_lock); 1967 FOREACH_THREAD_IN_PROC(p, td) { 1968 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1969 signal_td = td; 1970 break; 1971 } 1972 } 1973 if (signal_td == NULL) 1974 signal_td = FIRST_THREAD_IN_PROC(p); 1975 mtx_unlock_spin(&sched_lock); 1976 return (signal_td); 1977 } 1978 1979 /* 1980 * Send the signal to the process. If the signal has an action, the action 1981 * is usually performed by the target process rather than the caller; we add 1982 * the signal to the set of pending signals for the process. 1983 * 1984 * Exceptions: 1985 * o When a stop signal is sent to a sleeping process that takes the 1986 * default action, the process is stopped without awakening it. 1987 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1988 * regardless of the signal action (eg, blocked or ignored). 1989 * 1990 * Other ignored signals are discarded immediately. 1991 * 1992 * MPSAFE 1993 */ 1994 void 1995 psignal(struct proc *p, int sig) 1996 { 1997 (void) tdsignal(p, NULL, sig, NULL); 1998 } 1999 2000 int 2001 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 2002 { 2003 struct thread *td = NULL; 2004 2005 PROC_LOCK_ASSERT(p, MA_OWNED); 2006 2007 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 2008 2009 /* 2010 * ksi_code and other fields should be set before 2011 * calling this function. 2012 */ 2013 ksi->ksi_signo = sigev->sigev_signo; 2014 ksi->ksi_value = sigev->sigev_value; 2015 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2016 td = thread_find(p, sigev->sigev_notify_thread_id); 2017 if (td == NULL) 2018 return (ESRCH); 2019 } 2020 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 2021 } 2022 2023 /* 2024 * MPSAFE 2025 */ 2026 int 2027 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2028 { 2029 sigset_t saved; 2030 int ret; 2031 2032 if (p->p_flag & P_SA) 2033 saved = p->p_sigqueue.sq_signals; 2034 ret = do_tdsignal(p, td, sig, ksi); 2035 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 2036 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 2037 /* pending set changed */ 2038 p->p_flag |= P_SIGEVENT; 2039 wakeup(&p->p_siglist); 2040 } 2041 } 2042 return (ret); 2043 } 2044 2045 static int 2046 do_tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2047 { 2048 sig_t action; 2049 sigqueue_t *sigqueue; 2050 int prop; 2051 struct sigacts *ps; 2052 int ret = 0; 2053 2054 PROC_LOCK_ASSERT(p, MA_OWNED); 2055 2056 if (!_SIG_VALID(sig)) 2057 panic("do_tdsignal(): invalid signal"); 2058 2059 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue")); 2060 2061 /* 2062 * IEEE Std 1003.1-2001: return success when killing a zombie. 2063 */ 2064 if (p->p_state == PRS_ZOMBIE) { 2065 if (ksi && (ksi->ksi_flags & KSI_INS)) 2066 ksiginfo_tryfree(ksi); 2067 return (ret); 2068 } 2069 2070 ps = p->p_sigacts; 2071 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2072 prop = sigprop(sig); 2073 2074 /* 2075 * If the signal is blocked and not destined for this thread, then 2076 * assign it to the process so that we can find it later in the first 2077 * thread that unblocks it. Otherwise, assign it to this thread now. 2078 */ 2079 if (td == NULL) { 2080 td = sigtd(p, sig, prop); 2081 if (SIGISMEMBER(td->td_sigmask, sig)) 2082 sigqueue = &p->p_sigqueue; 2083 else 2084 sigqueue = &td->td_sigqueue; 2085 } else { 2086 KASSERT(td->td_proc == p, ("invalid thread")); 2087 sigqueue = &td->td_sigqueue; 2088 } 2089 2090 /* 2091 * If the signal is being ignored, 2092 * or process is exiting or thread is exiting, 2093 * then we forget about it immediately. 2094 * (Note: we don't set SIGCONT in ps_sigignore, 2095 * and if it is set to SIG_IGN, 2096 * action will be SIG_DFL here.) 2097 */ 2098 mtx_lock(&ps->ps_mtx); 2099 if (SIGISMEMBER(ps->ps_sigignore, sig) || 2100 (p->p_flag & P_WEXIT)) { 2101 mtx_unlock(&ps->ps_mtx); 2102 if (ksi && (ksi->ksi_flags & KSI_INS)) 2103 ksiginfo_tryfree(ksi); 2104 return (ret); 2105 } 2106 if (SIGISMEMBER(td->td_sigmask, sig)) 2107 action = SIG_HOLD; 2108 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2109 action = SIG_CATCH; 2110 else 2111 action = SIG_DFL; 2112 mtx_unlock(&ps->ps_mtx); 2113 2114 if (prop & SA_CONT) 2115 sigqueue_delete_stopmask_proc(p); 2116 else if (prop & SA_STOP) { 2117 /* 2118 * If sending a tty stop signal to a member of an orphaned 2119 * process group, discard the signal here if the action 2120 * is default; don't stop the process below if sleeping, 2121 * and don't clear any pending SIGCONT. 2122 */ 2123 if ((prop & SA_TTYSTOP) && 2124 (p->p_pgrp->pg_jobc == 0) && 2125 (action == SIG_DFL)) { 2126 if (ksi && (ksi->ksi_flags & KSI_INS)) 2127 ksiginfo_tryfree(ksi); 2128 return (ret); 2129 } 2130 sigqueue_delete_proc(p, SIGCONT); 2131 if (p->p_flag & P_CONTINUED) { 2132 p->p_flag &= ~P_CONTINUED; 2133 PROC_LOCK(p->p_pptr); 2134 sigqueue_take(p->p_ksi); 2135 PROC_UNLOCK(p->p_pptr); 2136 } 2137 } 2138 2139 ret = sigqueue_add(sigqueue, sig, ksi); 2140 if (ret != 0) 2141 return (ret); 2142 signotify(td); 2143 /* 2144 * Defer further processing for signals which are held, 2145 * except that stopped processes must be continued by SIGCONT. 2146 */ 2147 if (action == SIG_HOLD && 2148 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2149 return (ret); 2150 /* 2151 * SIGKILL: Remove procfs STOPEVENTs. 2152 */ 2153 if (sig == SIGKILL) { 2154 /* from procfs_ioctl.c: PIOCBIC */ 2155 p->p_stops = 0; 2156 /* from procfs_ioctl.c: PIOCCONT */ 2157 p->p_step = 0; 2158 wakeup(&p->p_step); 2159 } 2160 /* 2161 * Some signals have a process-wide effect and a per-thread 2162 * component. Most processing occurs when the process next 2163 * tries to cross the user boundary, however there are some 2164 * times when processing needs to be done immediatly, such as 2165 * waking up threads so that they can cross the user boundary. 2166 * We try do the per-process part here. 2167 */ 2168 if (P_SHOULDSTOP(p)) { 2169 /* 2170 * The process is in stopped mode. All the threads should be 2171 * either winding down or already on the suspended queue. 2172 */ 2173 if (p->p_flag & P_TRACED) { 2174 /* 2175 * The traced process is already stopped, 2176 * so no further action is necessary. 2177 * No signal can restart us. 2178 */ 2179 goto out; 2180 } 2181 2182 if (sig == SIGKILL) { 2183 /* 2184 * SIGKILL sets process running. 2185 * It will die elsewhere. 2186 * All threads must be restarted. 2187 */ 2188 p->p_flag &= ~P_STOPPED_SIG; 2189 goto runfast; 2190 } 2191 2192 if (prop & SA_CONT) { 2193 /* 2194 * If SIGCONT is default (or ignored), we continue the 2195 * process but don't leave the signal in sigqueue as 2196 * it has no further action. If SIGCONT is held, we 2197 * continue the process and leave the signal in 2198 * sigqueue. If the process catches SIGCONT, let it 2199 * handle the signal itself. If it isn't waiting on 2200 * an event, it goes back to run state. 2201 * Otherwise, process goes back to sleep state. 2202 */ 2203 p->p_flag &= ~P_STOPPED_SIG; 2204 if (p->p_numthreads == p->p_suspcount) { 2205 p->p_flag |= P_CONTINUED; 2206 p->p_xstat = SIGCONT; 2207 PROC_LOCK(p->p_pptr); 2208 childproc_continued(p); 2209 PROC_UNLOCK(p->p_pptr); 2210 } 2211 if (action == SIG_DFL) { 2212 sigqueue_delete(sigqueue, sig); 2213 } else if (action == SIG_CATCH) { 2214 /* 2215 * The process wants to catch it so it needs 2216 * to run at least one thread, but which one? 2217 * It would seem that the answer would be to 2218 * run an upcall in the next KSE to run, and 2219 * deliver the signal that way. In a NON KSE 2220 * process, we need to make sure that the 2221 * single thread is runnable asap. 2222 * XXXKSE for now however, make them all run. 2223 */ 2224 goto runfast; 2225 } 2226 /* 2227 * The signal is not ignored or caught. 2228 */ 2229 mtx_lock_spin(&sched_lock); 2230 thread_unsuspend(p); 2231 mtx_unlock_spin(&sched_lock); 2232 goto out; 2233 } 2234 2235 if (prop & SA_STOP) { 2236 /* 2237 * Already stopped, don't need to stop again 2238 * (If we did the shell could get confused). 2239 * Just make sure the signal STOP bit set. 2240 */ 2241 p->p_flag |= P_STOPPED_SIG; 2242 sigqueue_delete(sigqueue, sig); 2243 goto out; 2244 } 2245 2246 /* 2247 * All other kinds of signals: 2248 * If a thread is sleeping interruptibly, simulate a 2249 * wakeup so that when it is continued it will be made 2250 * runnable and can look at the signal. However, don't make 2251 * the PROCESS runnable, leave it stopped. 2252 * It may run a bit until it hits a thread_suspend_check(). 2253 */ 2254 mtx_lock_spin(&sched_lock); 2255 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2256 sleepq_abort(td); 2257 mtx_unlock_spin(&sched_lock); 2258 goto out; 2259 /* 2260 * Mutexes are short lived. Threads waiting on them will 2261 * hit thread_suspend_check() soon. 2262 */ 2263 } else if (p->p_state == PRS_NORMAL) { 2264 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2265 mtx_lock_spin(&sched_lock); 2266 tdsigwakeup(td, sig, action); 2267 mtx_unlock_spin(&sched_lock); 2268 goto out; 2269 } 2270 2271 MPASS(action == SIG_DFL); 2272 2273 if (prop & SA_STOP) { 2274 if (p->p_flag & P_PPWAIT) 2275 goto out; 2276 p->p_flag |= P_STOPPED_SIG; 2277 p->p_xstat = sig; 2278 mtx_lock_spin(&sched_lock); 2279 sig_suspend_threads(td, p, 1); 2280 if (p->p_numthreads == p->p_suspcount) { 2281 /* 2282 * only thread sending signal to another 2283 * process can reach here, if thread is sending 2284 * signal to its process, because thread does 2285 * not suspend itself here, p_numthreads 2286 * should never be equal to p_suspcount. 2287 */ 2288 thread_stopped(p); 2289 mtx_unlock_spin(&sched_lock); 2290 sigqueue_delete_proc(p, p->p_xstat); 2291 } else 2292 mtx_unlock_spin(&sched_lock); 2293 goto out; 2294 } 2295 else 2296 goto runfast; 2297 /* NOTREACHED */ 2298 } else { 2299 /* Not in "NORMAL" state. discard the signal. */ 2300 sigqueue_delete(sigqueue, sig); 2301 goto out; 2302 } 2303 2304 /* 2305 * The process is not stopped so we need to apply the signal to all the 2306 * running threads. 2307 */ 2308 2309 runfast: 2310 mtx_lock_spin(&sched_lock); 2311 tdsigwakeup(td, sig, action); 2312 thread_unsuspend(p); 2313 mtx_unlock_spin(&sched_lock); 2314 out: 2315 /* If we jump here, sched_lock should not be owned. */ 2316 mtx_assert(&sched_lock, MA_NOTOWNED); 2317 return (ret); 2318 } 2319 2320 /* 2321 * The force of a signal has been directed against a single 2322 * thread. We need to see what we can do about knocking it 2323 * out of any sleep it may be in etc. 2324 */ 2325 static void 2326 tdsigwakeup(struct thread *td, int sig, sig_t action) 2327 { 2328 struct proc *p = td->td_proc; 2329 register int prop; 2330 2331 PROC_LOCK_ASSERT(p, MA_OWNED); 2332 mtx_assert(&sched_lock, MA_OWNED); 2333 prop = sigprop(sig); 2334 2335 /* 2336 * Bring the priority of a thread up if we want it to get 2337 * killed in this lifetime. 2338 */ 2339 if (action == SIG_DFL && (prop & SA_KILL)) { 2340 if (p->p_nice > 0) 2341 sched_nice(td->td_proc, 0); 2342 if (td->td_priority > PUSER) 2343 sched_prio(td, PUSER); 2344 } 2345 2346 if (TD_ON_SLEEPQ(td)) { 2347 /* 2348 * If thread is sleeping uninterruptibly 2349 * we can't interrupt the sleep... the signal will 2350 * be noticed when the process returns through 2351 * trap() or syscall(). 2352 */ 2353 if ((td->td_flags & TDF_SINTR) == 0) 2354 return; 2355 /* 2356 * If SIGCONT is default (or ignored) and process is 2357 * asleep, we are finished; the process should not 2358 * be awakened. 2359 */ 2360 if ((prop & SA_CONT) && action == SIG_DFL) { 2361 mtx_unlock_spin(&sched_lock); 2362 sigqueue_delete(&p->p_sigqueue, sig); 2363 /* 2364 * It may be on either list in this state. 2365 * Remove from both for now. 2366 */ 2367 sigqueue_delete(&td->td_sigqueue, sig); 2368 mtx_lock_spin(&sched_lock); 2369 return; 2370 } 2371 2372 /* 2373 * Give low priority threads a better chance to run. 2374 */ 2375 if (td->td_priority > PUSER) 2376 sched_prio(td, PUSER); 2377 2378 sleepq_abort(td); 2379 } else { 2380 /* 2381 * Other states do nothing with the signal immediately, 2382 * other than kicking ourselves if we are running. 2383 * It will either never be noticed, or noticed very soon. 2384 */ 2385 #ifdef SMP 2386 if (TD_IS_RUNNING(td) && td != curthread) 2387 forward_signal(td); 2388 #endif 2389 } 2390 } 2391 2392 static void 2393 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2394 { 2395 struct thread *td2; 2396 2397 PROC_LOCK_ASSERT(p, MA_OWNED); 2398 mtx_assert(&sched_lock, MA_OWNED); 2399 2400 FOREACH_THREAD_IN_PROC(p, td2) { 2401 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2402 (td2->td_flags & TDF_SINTR) && 2403 !TD_IS_SUSPENDED(td2)) { 2404 thread_suspend_one(td2); 2405 } else { 2406 if (sending || td != td2) 2407 td2->td_flags |= TDF_ASTPENDING; 2408 #ifdef SMP 2409 if (TD_IS_RUNNING(td2) && td2 != td) 2410 forward_signal(td2); 2411 #endif 2412 } 2413 } 2414 } 2415 2416 int 2417 ptracestop(struct thread *td, int sig) 2418 { 2419 struct proc *p = td->td_proc; 2420 2421 PROC_LOCK_ASSERT(p, MA_OWNED); 2422 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2423 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2424 2425 mtx_lock_spin(&sched_lock); 2426 td->td_flags |= TDF_XSIG; 2427 mtx_unlock_spin(&sched_lock); 2428 td->td_xsig = sig; 2429 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2430 if (p->p_flag & P_SINGLE_EXIT) { 2431 mtx_lock_spin(&sched_lock); 2432 td->td_flags &= ~TDF_XSIG; 2433 mtx_unlock_spin(&sched_lock); 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 mtx_lock_spin(&sched_lock); 2444 sig_suspend_threads(td, p, 0); 2445 stopme: 2446 thread_stopped(p); 2447 thread_suspend_one(td); 2448 PROC_UNLOCK(p); 2449 DROP_GIANT(); 2450 mi_switch(SW_VOL, NULL); 2451 mtx_unlock_spin(&sched_lock); 2452 PICKUP_GIANT(); 2453 PROC_LOCK(p); 2454 if (!(p->p_flag & P_TRACED)) 2455 break; 2456 if (td->td_flags & TDF_DBSUSPEND) { 2457 if (p->p_flag & P_SINGLE_EXIT) 2458 break; 2459 mtx_lock_spin(&sched_lock); 2460 goto stopme; 2461 } 2462 } 2463 return (td->td_xsig); 2464 } 2465 2466 /* 2467 * If the current process has received a signal (should be caught or cause 2468 * termination, should interrupt current syscall), return the signal number. 2469 * Stop signals with default action are processed immediately, then cleared; 2470 * they aren't returned. This is checked after each entry to the system for 2471 * a syscall or trap (though this can usually be done without calling issignal 2472 * by checking the pending signal masks in cursig.) The normal call 2473 * sequence is 2474 * 2475 * while (sig = cursig(curthread)) 2476 * postsig(sig); 2477 */ 2478 static int 2479 issignal(td) 2480 struct thread *td; 2481 { 2482 struct proc *p; 2483 struct sigacts *ps; 2484 sigset_t sigpending; 2485 int sig, prop, newsig; 2486 2487 p = td->td_proc; 2488 ps = p->p_sigacts; 2489 mtx_assert(&ps->ps_mtx, MA_OWNED); 2490 PROC_LOCK_ASSERT(p, MA_OWNED); 2491 for (;;) { 2492 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2493 2494 sigpending = td->td_sigqueue.sq_signals; 2495 SIGSETNAND(sigpending, td->td_sigmask); 2496 2497 if (p->p_flag & P_PPWAIT) 2498 SIG_STOPSIGMASK(sigpending); 2499 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2500 return (0); 2501 sig = sig_ffs(&sigpending); 2502 2503 if (p->p_stops & S_SIG) { 2504 mtx_unlock(&ps->ps_mtx); 2505 stopevent(p, S_SIG, sig); 2506 mtx_lock(&ps->ps_mtx); 2507 } 2508 2509 /* 2510 * We should see pending but ignored signals 2511 * only if P_TRACED was on when they were posted. 2512 */ 2513 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2514 sigqueue_delete(&td->td_sigqueue, sig); 2515 if (td->td_pflags & TDP_SA) 2516 SIGADDSET(td->td_sigmask, sig); 2517 continue; 2518 } 2519 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2520 /* 2521 * If traced, always stop. 2522 */ 2523 mtx_unlock(&ps->ps_mtx); 2524 newsig = ptracestop(td, sig); 2525 mtx_lock(&ps->ps_mtx); 2526 2527 if (td->td_pflags & TDP_SA) 2528 SIGADDSET(td->td_sigmask, sig); 2529 2530 if (sig != newsig) { 2531 ksiginfo_t ksi; 2532 /* 2533 * clear old signal. 2534 * XXX shrug off debugger, it causes siginfo to 2535 * be thrown away. 2536 */ 2537 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2538 2539 /* 2540 * If parent wants us to take the signal, 2541 * then it will leave it in p->p_xstat; 2542 * otherwise we just look for signals again. 2543 */ 2544 if (newsig == 0) 2545 continue; 2546 sig = newsig; 2547 2548 /* 2549 * Put the new signal into td_sigqueue. If the 2550 * signal is being masked, look for other signals. 2551 */ 2552 SIGADDSET(td->td_sigqueue.sq_signals, sig); 2553 if (td->td_pflags & TDP_SA) 2554 SIGDELSET(td->td_sigmask, sig); 2555 if (SIGISMEMBER(td->td_sigmask, sig)) 2556 continue; 2557 signotify(td); 2558 } 2559 2560 /* 2561 * If the traced bit got turned off, go back up 2562 * to the top to rescan signals. This ensures 2563 * that p_sig* and p_sigact are consistent. 2564 */ 2565 if ((p->p_flag & P_TRACED) == 0) 2566 continue; 2567 } 2568 2569 prop = sigprop(sig); 2570 2571 /* 2572 * Decide whether the signal should be returned. 2573 * Return the signal's number, or fall through 2574 * to clear it from the pending mask. 2575 */ 2576 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2577 2578 case (intptr_t)SIG_DFL: 2579 /* 2580 * Don't take default actions on system processes. 2581 */ 2582 if (p->p_pid <= 1) { 2583 #ifdef DIAGNOSTIC 2584 /* 2585 * Are you sure you want to ignore SIGSEGV 2586 * in init? XXX 2587 */ 2588 printf("Process (pid %lu) got signal %d\n", 2589 (u_long)p->p_pid, sig); 2590 #endif 2591 break; /* == ignore */ 2592 } 2593 /* 2594 * If there is a pending stop signal to process 2595 * with default action, stop here, 2596 * then clear the signal. However, 2597 * if process is member of an orphaned 2598 * process group, ignore tty stop signals. 2599 */ 2600 if (prop & SA_STOP) { 2601 if (p->p_flag & P_TRACED || 2602 (p->p_pgrp->pg_jobc == 0 && 2603 prop & SA_TTYSTOP)) 2604 break; /* == ignore */ 2605 mtx_unlock(&ps->ps_mtx); 2606 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2607 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2608 p->p_flag |= P_STOPPED_SIG; 2609 p->p_xstat = sig; 2610 mtx_lock_spin(&sched_lock); 2611 sig_suspend_threads(td, p, 0); 2612 thread_stopped(p); 2613 thread_suspend_one(td); 2614 PROC_UNLOCK(p); 2615 DROP_GIANT(); 2616 mi_switch(SW_INVOL, NULL); 2617 mtx_unlock_spin(&sched_lock); 2618 PICKUP_GIANT(); 2619 PROC_LOCK(p); 2620 mtx_lock(&ps->ps_mtx); 2621 break; 2622 } else if (prop & SA_IGNORE) { 2623 /* 2624 * Except for SIGCONT, shouldn't get here. 2625 * Default action is to ignore; drop it. 2626 */ 2627 break; /* == ignore */ 2628 } else 2629 return (sig); 2630 /*NOTREACHED*/ 2631 2632 case (intptr_t)SIG_IGN: 2633 /* 2634 * Masking above should prevent us ever trying 2635 * to take action on an ignored signal other 2636 * than SIGCONT, unless process is traced. 2637 */ 2638 if ((prop & SA_CONT) == 0 && 2639 (p->p_flag & P_TRACED) == 0) 2640 printf("issignal\n"); 2641 break; /* == ignore */ 2642 2643 default: 2644 /* 2645 * This signal has an action, let 2646 * postsig() process it. 2647 */ 2648 return (sig); 2649 } 2650 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2651 } 2652 /* NOTREACHED */ 2653 } 2654 2655 /* 2656 * MPSAFE 2657 */ 2658 void 2659 thread_stopped(struct proc *p) 2660 { 2661 struct proc *p1 = curthread->td_proc; 2662 int n; 2663 2664 PROC_LOCK_ASSERT(p, MA_OWNED); 2665 mtx_assert(&sched_lock, MA_OWNED); 2666 n = p->p_suspcount; 2667 if (p == p1) 2668 n++; 2669 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2670 mtx_unlock_spin(&sched_lock); 2671 p->p_flag &= ~P_WAITED; 2672 PROC_LOCK(p->p_pptr); 2673 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2674 CLD_TRAPPED : CLD_STOPPED); 2675 PROC_UNLOCK(p->p_pptr); 2676 mtx_lock_spin(&sched_lock); 2677 } 2678 } 2679 2680 /* 2681 * Take the action for the specified signal 2682 * from the current set of pending signals. 2683 */ 2684 void 2685 postsig(sig) 2686 register int sig; 2687 { 2688 struct thread *td = curthread; 2689 register struct proc *p = td->td_proc; 2690 struct sigacts *ps; 2691 sig_t action; 2692 ksiginfo_t ksi; 2693 sigset_t returnmask; 2694 int code; 2695 2696 KASSERT(sig != 0, ("postsig")); 2697 2698 PROC_LOCK_ASSERT(p, MA_OWNED); 2699 ps = p->p_sigacts; 2700 mtx_assert(&ps->ps_mtx, MA_OWNED); 2701 ksiginfo_init(&ksi); 2702 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2703 ksi.ksi_signo = sig; 2704 if (ksi.ksi_code == SI_TIMER) 2705 itimer_accept(p, ksi.ksi_timerid, &ksi); 2706 action = ps->ps_sigact[_SIG_IDX(sig)]; 2707 #ifdef KTRACE 2708 if (KTRPOINT(td, KTR_PSIG)) 2709 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2710 &td->td_oldsigmask : &td->td_sigmask, 0); 2711 #endif 2712 if (p->p_stops & S_SIG) { 2713 mtx_unlock(&ps->ps_mtx); 2714 stopevent(p, S_SIG, sig); 2715 mtx_lock(&ps->ps_mtx); 2716 } 2717 2718 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2719 /* 2720 * Default action, where the default is to kill 2721 * the process. (Other cases were ignored above.) 2722 */ 2723 mtx_unlock(&ps->ps_mtx); 2724 sigexit(td, sig); 2725 /* NOTREACHED */ 2726 } else { 2727 if (td->td_pflags & TDP_SA) { 2728 if (sig == SIGKILL) { 2729 mtx_unlock(&ps->ps_mtx); 2730 sigexit(td, sig); 2731 } 2732 } 2733 2734 /* 2735 * If we get here, the signal must be caught. 2736 */ 2737 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2738 ("postsig action")); 2739 /* 2740 * Set the new mask value and also defer further 2741 * occurrences of this signal. 2742 * 2743 * Special case: user has done a sigsuspend. Here the 2744 * current mask is not of interest, but rather the 2745 * mask from before the sigsuspend is what we want 2746 * restored after the signal processing is completed. 2747 */ 2748 if (td->td_pflags & TDP_OLDMASK) { 2749 returnmask = td->td_oldsigmask; 2750 td->td_pflags &= ~TDP_OLDMASK; 2751 } else 2752 returnmask = td->td_sigmask; 2753 2754 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2755 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2756 SIGADDSET(td->td_sigmask, sig); 2757 2758 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2759 /* 2760 * See kern_sigaction() for origin of this code. 2761 */ 2762 SIGDELSET(ps->ps_sigcatch, sig); 2763 if (sig != SIGCONT && 2764 sigprop(sig) & SA_IGNORE) 2765 SIGADDSET(ps->ps_sigignore, sig); 2766 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2767 } 2768 p->p_stats->p_ru.ru_nsignals++; 2769 if (p->p_sig != sig) { 2770 code = 0; 2771 } else { 2772 code = p->p_code; 2773 p->p_code = 0; 2774 p->p_sig = 0; 2775 } 2776 if (td->td_pflags & TDP_SA) 2777 thread_signal_add(curthread, &ksi); 2778 else 2779 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2780 } 2781 } 2782 2783 /* 2784 * Kill the current process for stated reason. 2785 */ 2786 void 2787 killproc(p, why) 2788 struct proc *p; 2789 char *why; 2790 { 2791 2792 PROC_LOCK_ASSERT(p, MA_OWNED); 2793 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2794 p, p->p_pid, p->p_comm); 2795 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2796 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2797 psignal(p, SIGKILL); 2798 } 2799 2800 /* 2801 * Force the current process to exit with the specified signal, dumping core 2802 * if appropriate. We bypass the normal tests for masked and caught signals, 2803 * allowing unrecoverable failures to terminate the process without changing 2804 * signal state. Mark the accounting record with the signal termination. 2805 * If dumping core, save the signal number for the debugger. Calls exit and 2806 * does not return. 2807 * 2808 * MPSAFE 2809 */ 2810 void 2811 sigexit(td, sig) 2812 struct thread *td; 2813 int sig; 2814 { 2815 struct proc *p = td->td_proc; 2816 2817 PROC_LOCK_ASSERT(p, MA_OWNED); 2818 p->p_acflag |= AXSIG; 2819 /* 2820 * We must be single-threading to generate a core dump. This 2821 * ensures that the registers in the core file are up-to-date. 2822 * Also, the ELF dump handler assumes that the thread list doesn't 2823 * change out from under it. 2824 * 2825 * XXX If another thread attempts to single-thread before us 2826 * (e.g. via fork()), we won't get a dump at all. 2827 */ 2828 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2829 p->p_sig = sig; 2830 /* 2831 * Log signals which would cause core dumps 2832 * (Log as LOG_INFO to appease those who don't want 2833 * these messages.) 2834 * XXX : Todo, as well as euid, write out ruid too 2835 * Note that coredump() drops proc lock. 2836 */ 2837 if (coredump(td) == 0) 2838 sig |= WCOREFLAG; 2839 if (kern_logsigexit) 2840 log(LOG_INFO, 2841 "pid %d (%s), uid %d: exited on signal %d%s\n", 2842 p->p_pid, p->p_comm, 2843 td->td_ucred ? td->td_ucred->cr_uid : -1, 2844 sig &~ WCOREFLAG, 2845 sig & WCOREFLAG ? " (core dumped)" : ""); 2846 } else 2847 PROC_UNLOCK(p); 2848 exit1(td, W_EXITCODE(0, sig)); 2849 /* NOTREACHED */ 2850 } 2851 2852 /* 2853 * Send queued SIGCHLD to parent when child process's state 2854 * is changed. 2855 */ 2856 static void 2857 sigparent(struct proc *p, int reason, int status) 2858 { 2859 PROC_LOCK_ASSERT(p, MA_OWNED); 2860 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2861 2862 if (p->p_ksi != NULL) { 2863 p->p_ksi->ksi_signo = SIGCHLD; 2864 p->p_ksi->ksi_code = reason; 2865 p->p_ksi->ksi_status = status; 2866 p->p_ksi->ksi_pid = p->p_pid; 2867 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2868 if (KSI_ONQ(p->p_ksi)) 2869 return; 2870 } 2871 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2872 } 2873 2874 static void 2875 childproc_jobstate(struct proc *p, int reason, int status) 2876 { 2877 struct sigacts *ps; 2878 2879 PROC_LOCK_ASSERT(p, MA_OWNED); 2880 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2881 2882 /* 2883 * Wake up parent sleeping in kern_wait(), also send 2884 * SIGCHLD to parent, but SIGCHLD does not guarantee 2885 * that parent will awake, because parent may masked 2886 * the signal. 2887 */ 2888 p->p_pptr->p_flag |= P_STATCHILD; 2889 wakeup(p->p_pptr); 2890 2891 ps = p->p_pptr->p_sigacts; 2892 mtx_lock(&ps->ps_mtx); 2893 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2894 mtx_unlock(&ps->ps_mtx); 2895 sigparent(p, reason, status); 2896 } else 2897 mtx_unlock(&ps->ps_mtx); 2898 } 2899 2900 void 2901 childproc_stopped(struct proc *p, int reason) 2902 { 2903 childproc_jobstate(p, reason, p->p_xstat); 2904 } 2905 2906 void 2907 childproc_continued(struct proc *p) 2908 { 2909 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2910 } 2911 2912 void 2913 childproc_exited(struct proc *p) 2914 { 2915 int reason; 2916 int status = p->p_xstat; /* convert to int */ 2917 2918 reason = CLD_EXITED; 2919 if (WCOREDUMP(status)) 2920 reason = CLD_DUMPED; 2921 else if (WIFSIGNALED(status)) 2922 reason = CLD_KILLED; 2923 /* 2924 * XXX avoid calling wakeup(p->p_pptr), the work is 2925 * done in exit1(). 2926 */ 2927 sigparent(p, reason, status); 2928 } 2929 2930 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2931 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2932 sizeof(corefilename), "process corefile name format string"); 2933 2934 /* 2935 * expand_name(name, uid, pid) 2936 * Expand the name described in corefilename, using name, uid, and pid. 2937 * corefilename is a printf-like string, with three format specifiers: 2938 * %N name of process ("name") 2939 * %P process id (pid) 2940 * %U user id (uid) 2941 * For example, "%N.core" is the default; they can be disabled completely 2942 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2943 * This is controlled by the sysctl variable kern.corefile (see above). 2944 */ 2945 2946 static char * 2947 expand_name(name, uid, pid) 2948 const char *name; 2949 uid_t uid; 2950 pid_t pid; 2951 { 2952 const char *format, *appendstr; 2953 char *temp; 2954 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2955 size_t i, l, n; 2956 2957 format = corefilename; 2958 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2959 if (temp == NULL) 2960 return (NULL); 2961 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2962 switch (format[i]) { 2963 case '%': /* Format character */ 2964 i++; 2965 switch (format[i]) { 2966 case '%': 2967 appendstr = "%"; 2968 break; 2969 case 'N': /* process name */ 2970 appendstr = name; 2971 break; 2972 case 'P': /* process id */ 2973 sprintf(buf, "%u", pid); 2974 appendstr = buf; 2975 break; 2976 case 'U': /* user id */ 2977 sprintf(buf, "%u", uid); 2978 appendstr = buf; 2979 break; 2980 default: 2981 appendstr = ""; 2982 log(LOG_ERR, 2983 "Unknown format character %c in `%s'\n", 2984 format[i], format); 2985 } 2986 l = strlen(appendstr); 2987 if ((n + l) >= MAXPATHLEN) 2988 goto toolong; 2989 memcpy(temp + n, appendstr, l); 2990 n += l; 2991 break; 2992 default: 2993 temp[n++] = format[i]; 2994 } 2995 } 2996 if (format[i] != '\0') 2997 goto toolong; 2998 return (temp); 2999 toolong: 3000 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 3001 (long)pid, name, (u_long)uid); 3002 free(temp, M_TEMP); 3003 return (NULL); 3004 } 3005 3006 /* 3007 * Dump a process' core. The main routine does some 3008 * policy checking, and creates the name of the coredump; 3009 * then it passes on a vnode and a size limit to the process-specific 3010 * coredump routine if there is one; if there _is not_ one, it returns 3011 * ENOSYS; otherwise it returns the error from the process-specific routine. 3012 */ 3013 3014 static int 3015 coredump(struct thread *td) 3016 { 3017 struct proc *p = td->td_proc; 3018 register struct vnode *vp; 3019 register struct ucred *cred = td->td_ucred; 3020 struct flock lf; 3021 struct nameidata nd; 3022 struct vattr vattr; 3023 int error, error1, flags, locked; 3024 struct mount *mp; 3025 char *name; /* name of corefile */ 3026 off_t limit; 3027 3028 PROC_LOCK_ASSERT(p, MA_OWNED); 3029 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3030 _STOPEVENT(p, S_CORE, 0); 3031 3032 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3033 PROC_UNLOCK(p); 3034 return (EFAULT); 3035 } 3036 3037 /* 3038 * Note that the bulk of limit checking is done after 3039 * the corefile is created. The exception is if the limit 3040 * for corefiles is 0, in which case we don't bother 3041 * creating the corefile at all. This layout means that 3042 * a corefile is truncated instead of not being created, 3043 * if it is larger than the limit. 3044 */ 3045 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3046 PROC_UNLOCK(p); 3047 if (limit == 0) 3048 return (EFBIG); 3049 3050 mtx_lock(&Giant); 3051 restart: 3052 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3053 if (name == NULL) { 3054 mtx_unlock(&Giant); 3055 return (EINVAL); 3056 } 3057 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 3058 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3059 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 3060 free(name, M_TEMP); 3061 if (error) { 3062 mtx_unlock(&Giant); 3063 return (error); 3064 } 3065 NDFREE(&nd, NDF_ONLY_PNBUF); 3066 vp = nd.ni_vp; 3067 3068 /* Don't dump to non-regular files or files with links. */ 3069 if (vp->v_type != VREG || 3070 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 3071 VOP_UNLOCK(vp, 0, td); 3072 error = EFAULT; 3073 goto out; 3074 } 3075 3076 VOP_UNLOCK(vp, 0, td); 3077 lf.l_whence = SEEK_SET; 3078 lf.l_start = 0; 3079 lf.l_len = 0; 3080 lf.l_type = F_WRLCK; 3081 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3082 3083 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3084 lf.l_type = F_UNLCK; 3085 if (locked) 3086 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3087 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3088 return (error); 3089 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3090 return (error); 3091 goto restart; 3092 } 3093 3094 VATTR_NULL(&vattr); 3095 vattr.va_size = 0; 3096 if (set_core_nodump_flag) 3097 vattr.va_flags = UF_NODUMP; 3098 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 3099 VOP_LEASE(vp, td, cred, LEASE_WRITE); 3100 VOP_SETATTR(vp, &vattr, cred, td); 3101 VOP_UNLOCK(vp, 0, td); 3102 PROC_LOCK(p); 3103 p->p_acflag |= ACORE; 3104 PROC_UNLOCK(p); 3105 3106 error = p->p_sysent->sv_coredump ? 3107 p->p_sysent->sv_coredump(td, vp, limit) : 3108 ENOSYS; 3109 3110 if (locked) { 3111 lf.l_type = F_UNLCK; 3112 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3113 } 3114 vn_finished_write(mp); 3115 out: 3116 error1 = vn_close(vp, FWRITE, cred, td); 3117 mtx_unlock(&Giant); 3118 if (error == 0) 3119 error = error1; 3120 return (error); 3121 } 3122 3123 /* 3124 * Nonexistent system call-- signal process (may want to handle it). 3125 * Flag error in case process won't see signal immediately (blocked or ignored). 3126 */ 3127 #ifndef _SYS_SYSPROTO_H_ 3128 struct nosys_args { 3129 int dummy; 3130 }; 3131 #endif 3132 /* 3133 * MPSAFE 3134 */ 3135 /* ARGSUSED */ 3136 int 3137 nosys(td, args) 3138 struct thread *td; 3139 struct nosys_args *args; 3140 { 3141 struct proc *p = td->td_proc; 3142 3143 PROC_LOCK(p); 3144 psignal(p, SIGSYS); 3145 PROC_UNLOCK(p); 3146 return (ENOSYS); 3147 } 3148 3149 /* 3150 * Send a SIGIO or SIGURG signal to a process or process group using 3151 * stored credentials rather than those of the current process. 3152 */ 3153 void 3154 pgsigio(sigiop, sig, checkctty) 3155 struct sigio **sigiop; 3156 int sig, checkctty; 3157 { 3158 struct sigio *sigio; 3159 3160 SIGIO_LOCK(); 3161 sigio = *sigiop; 3162 if (sigio == NULL) { 3163 SIGIO_UNLOCK(); 3164 return; 3165 } 3166 if (sigio->sio_pgid > 0) { 3167 PROC_LOCK(sigio->sio_proc); 3168 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3169 psignal(sigio->sio_proc, sig); 3170 PROC_UNLOCK(sigio->sio_proc); 3171 } else if (sigio->sio_pgid < 0) { 3172 struct proc *p; 3173 3174 PGRP_LOCK(sigio->sio_pgrp); 3175 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3176 PROC_LOCK(p); 3177 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3178 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3179 psignal(p, sig); 3180 PROC_UNLOCK(p); 3181 } 3182 PGRP_UNLOCK(sigio->sio_pgrp); 3183 } 3184 SIGIO_UNLOCK(); 3185 } 3186 3187 static int 3188 filt_sigattach(struct knote *kn) 3189 { 3190 struct proc *p = curproc; 3191 3192 kn->kn_ptr.p_proc = p; 3193 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3194 3195 knlist_add(&p->p_klist, kn, 0); 3196 3197 return (0); 3198 } 3199 3200 static void 3201 filt_sigdetach(struct knote *kn) 3202 { 3203 struct proc *p = kn->kn_ptr.p_proc; 3204 3205 knlist_remove(&p->p_klist, kn, 0); 3206 } 3207 3208 /* 3209 * signal knotes are shared with proc knotes, so we apply a mask to 3210 * the hint in order to differentiate them from process hints. This 3211 * could be avoided by using a signal-specific knote list, but probably 3212 * isn't worth the trouble. 3213 */ 3214 static int 3215 filt_signal(struct knote *kn, long hint) 3216 { 3217 3218 if (hint & NOTE_SIGNAL) { 3219 hint &= ~NOTE_SIGNAL; 3220 3221 if (kn->kn_id == hint) 3222 kn->kn_data++; 3223 } 3224 return (kn->kn_data != 0); 3225 } 3226 3227 struct sigacts * 3228 sigacts_alloc(void) 3229 { 3230 struct sigacts *ps; 3231 3232 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3233 ps->ps_refcnt = 1; 3234 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3235 return (ps); 3236 } 3237 3238 void 3239 sigacts_free(struct sigacts *ps) 3240 { 3241 3242 mtx_lock(&ps->ps_mtx); 3243 ps->ps_refcnt--; 3244 if (ps->ps_refcnt == 0) { 3245 mtx_destroy(&ps->ps_mtx); 3246 free(ps, M_SUBPROC); 3247 } else 3248 mtx_unlock(&ps->ps_mtx); 3249 } 3250 3251 struct sigacts * 3252 sigacts_hold(struct sigacts *ps) 3253 { 3254 mtx_lock(&ps->ps_mtx); 3255 ps->ps_refcnt++; 3256 mtx_unlock(&ps->ps_mtx); 3257 return (ps); 3258 } 3259 3260 void 3261 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3262 { 3263 3264 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3265 mtx_lock(&src->ps_mtx); 3266 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3267 mtx_unlock(&src->ps_mtx); 3268 } 3269 3270 int 3271 sigacts_shared(struct sigacts *ps) 3272 { 3273 int shared; 3274 3275 mtx_lock(&ps->ps_mtx); 3276 shared = ps->ps_refcnt > 1; 3277 mtx_unlock(&ps->ps_mtx); 3278 return (shared); 3279 } 3280