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/unistd.h> 73 #include <sys/wait.h> 74 #include <vm/vm.h> 75 #include <vm/vm_extern.h> 76 #include <vm/uma.h> 77 78 #include <machine/cpu.h> 79 80 #if defined (__alpha__) && !defined(COMPAT_43) 81 #error "You *really* need COMPAT_43 on the alpha for longjmp(3)" 82 #endif 83 84 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 85 86 static int coredump(struct thread *); 87 static char *expand_name(const char *, uid_t, pid_t); 88 static int killpg1(struct thread *td, int sig, int pgid, int all); 89 static int issignal(struct thread *p); 90 static int sigprop(int sig); 91 static void tdsigwakeup(struct thread *td, int sig, sig_t action); 92 static int filt_sigattach(struct knote *kn); 93 static void filt_sigdetach(struct knote *kn); 94 static int filt_signal(struct knote *kn, long hint); 95 static struct thread *sigtd(struct proc *p, int sig, int prop); 96 static int kern_sigtimedwait(struct thread *, sigset_t, 97 ksiginfo_t *, struct timespec *); 98 static int do_tdsignal(struct thread *, int, ksiginfo_t *, sigtarget_t); 99 static void sigqueue_start(void); 100 static ksiginfo_t * ksiginfo_alloc(void); 101 static void ksiginfo_free(ksiginfo_t *); 102 static int psignal_common(struct proc *p, int sig, ksiginfo_t *ksi); 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 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 114 115 static int max_pending_per_proc = 128; 116 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 117 &max_pending_per_proc, 0, "Max pending signals per proc"); 118 119 static int queue_rt_signal_only = 1; 120 SYSCTL_INT(_kern_sigqueue, OID_AUTO, queue_rt_signal_only, CTLFLAG_RW, 121 &queue_rt_signal_only, 0, "Only rt signal is queued"); 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, signal_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, signal_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 } 217 218 static ksiginfo_t * 219 ksiginfo_alloc(void) 220 { 221 if (ksiginfo_zone != NULL) 222 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, M_NOWAIT)); 223 return (NULL); 224 } 225 226 static void 227 ksiginfo_free(ksiginfo_t *ksi) 228 { 229 uma_zfree(ksiginfo_zone, ksi); 230 } 231 232 void 233 sigqueue_init(sigqueue_t *list, struct proc *p) 234 { 235 SIGEMPTYSET(list->sq_signals); 236 TAILQ_INIT(&list->sq_list); 237 list->sq_proc = p; 238 list->sq_flags = SQ_INIT; 239 } 240 241 /* 242 * Get a signal's ksiginfo. 243 * Return: 244 * 0 - signal not found 245 * others - signal number 246 */ 247 int 248 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 249 { 250 struct proc *p = sq->sq_proc; 251 struct ksiginfo *ksi, *next; 252 int count = 0; 253 254 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 255 256 ksiginfo_init(si); 257 if (!SIGISMEMBER(sq->sq_signals, signo)) 258 return (0); 259 260 for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { 261 next = TAILQ_NEXT(ksi, ksi_link); 262 if (ksi->ksi_signo == signo) { 263 if (count == 0) { 264 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 265 ksiginfo_copy(ksi, si); 266 ksiginfo_free(ksi); 267 if (p != NULL) 268 p->p_pendingcnt--; 269 } 270 count++; 271 } 272 } 273 274 if (count <= 1) 275 SIGDELSET(sq->sq_signals, signo); 276 si->ksi_signo = signo; 277 return (signo); 278 } 279 280 int 281 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 282 { 283 struct proc *p = sq->sq_proc; 284 struct ksiginfo *ksi; 285 int ret = 0; 286 287 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 288 289 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) 290 goto out_set_bit; 291 292 if (__predict_false(ksiginfo_zone == NULL)) 293 goto out_set_bit; 294 295 if (p != NULL && p->p_pendingcnt > max_pending_per_proc) { 296 signal_overflow++; 297 ret = EAGAIN; 298 } else if ((ksi = ksiginfo_alloc()) == NULL) { 299 signal_alloc_fail++; 300 ret = EAGAIN; 301 } else { 302 if (p != NULL) 303 p->p_pendingcnt++; 304 ksiginfo_copy(si, ksi); 305 ksi->ksi_signo = signo; 306 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 307 } 308 309 if ((si->ksi_flags & KSI_TRAP) != 0) { 310 ret = 0; 311 goto out_set_bit; 312 } 313 314 if (ret != 0) 315 return (ret); 316 317 out_set_bit: 318 SIGADDSET(sq->sq_signals, signo); 319 return (ret); 320 } 321 322 void 323 sigqueue_flush(sigqueue_t *sq) 324 { 325 struct proc *p = sq->sq_proc; 326 ksiginfo_t *ksi; 327 328 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 329 330 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 331 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 332 ksiginfo_free(ksi); 333 if (p != NULL) 334 p->p_pendingcnt--; 335 } 336 337 SIGEMPTYSET(sq->sq_signals); 338 } 339 340 void 341 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 342 { 343 ksiginfo_t *ksi; 344 345 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 346 347 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 348 SIGADDSET(*set, ksi->ksi_signo); 349 } 350 351 void 352 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 353 { 354 sigset_t tmp, set; 355 struct proc *p1, *p2; 356 ksiginfo_t *ksi, *next; 357 358 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 359 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 360 /* 361 * make a copy, this allows setp to point to src or dst 362 * sq_signals without trouble. 363 */ 364 set = *setp; 365 p1 = src->sq_proc; 366 p2 = dst->sq_proc; 367 /* Move siginfo to target list */ 368 for (ksi = TAILQ_FIRST(&src->sq_list); ksi != NULL; ksi = next) { 369 next = TAILQ_NEXT(ksi, ksi_link); 370 if (SIGISMEMBER(set, ksi->ksi_signo)) { 371 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 372 if (p1 != NULL) 373 p1->p_pendingcnt--; 374 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 375 if (p2 != NULL) 376 p2->p_pendingcnt++; 377 } 378 } 379 380 /* Move pending bits to target list */ 381 tmp = src->sq_signals; 382 SIGSETAND(tmp, set); 383 SIGSETOR(dst->sq_signals, tmp); 384 SIGSETNAND(src->sq_signals, tmp); 385 386 /* Finally, rescan src queue and set pending bits for it */ 387 sigqueue_collect_set(src, &src->sq_signals); 388 } 389 390 void 391 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 392 { 393 sigset_t set; 394 395 SIGEMPTYSET(set); 396 SIGADDSET(set, signo); 397 sigqueue_move_set(src, dst, &set); 398 } 399 400 void 401 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 402 { 403 struct proc *p = sq->sq_proc; 404 ksiginfo_t *ksi, *next; 405 406 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 407 408 /* Remove siginfo queue */ 409 for (ksi = TAILQ_FIRST(&sq->sq_list); ksi != NULL; ksi = next) { 410 next = TAILQ_NEXT(ksi, ksi_link); 411 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 412 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 413 ksiginfo_free(ksi); 414 if (p != NULL) 415 p->p_pendingcnt--; 416 } 417 } 418 SIGSETNAND(sq->sq_signals, *set); 419 /* Finally, rescan queue and set pending bits for it */ 420 sigqueue_collect_set(sq, &sq->sq_signals); 421 } 422 423 void 424 sigqueue_delete(sigqueue_t *sq, int signo) 425 { 426 sigset_t set; 427 428 SIGEMPTYSET(set); 429 SIGADDSET(set, signo); 430 sigqueue_delete_set(sq, &set); 431 } 432 433 /* Remove a set of signals for a process */ 434 void 435 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 436 { 437 sigqueue_t worklist; 438 struct thread *td0; 439 440 PROC_LOCK_ASSERT(p, MA_OWNED); 441 442 sigqueue_init(&worklist, NULL); 443 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 444 445 mtx_lock_spin(&sched_lock); 446 FOREACH_THREAD_IN_PROC(p, td0) 447 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 448 mtx_unlock_spin(&sched_lock); 449 450 sigqueue_flush(&worklist); 451 } 452 453 void 454 sigqueue_delete_proc(struct proc *p, int signo) 455 { 456 sigset_t set; 457 458 SIGEMPTYSET(set); 459 SIGADDSET(set, signo); 460 sigqueue_delete_set_proc(p, &set); 461 } 462 463 void 464 sigqueue_delete_stopmask_proc(struct proc *p) 465 { 466 sigset_t set; 467 468 SIGEMPTYSET(set); 469 SIGADDSET(set, SIGSTOP); 470 SIGADDSET(set, SIGTSTP); 471 SIGADDSET(set, SIGTTIN); 472 SIGADDSET(set, SIGTTOU); 473 sigqueue_delete_set_proc(p, &set); 474 } 475 476 /* 477 * Determine signal that should be delivered to process p, the current 478 * process, 0 if none. If there is a pending stop signal with default 479 * action, the process stops in issignal(). 480 * 481 * MP SAFE. 482 */ 483 int 484 cursig(struct thread *td) 485 { 486 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 487 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 488 mtx_assert(&sched_lock, MA_NOTOWNED); 489 return (SIGPENDING(td) ? issignal(td) : 0); 490 } 491 492 /* 493 * Arrange for ast() to handle unmasked pending signals on return to user 494 * mode. This must be called whenever a signal is added to td_sigqueue or 495 * unmasked in td_sigmask. 496 */ 497 void 498 signotify(struct thread *td) 499 { 500 struct proc *p; 501 sigset_t set, saved; 502 503 p = td->td_proc; 504 505 PROC_LOCK_ASSERT(p, MA_OWNED); 506 507 /* 508 * If our mask changed we may have to move signal that were 509 * previously masked by all threads to our sigqueue. 510 */ 511 set = p->p_sigqueue.sq_signals; 512 if (p->p_flag & P_SA) 513 saved = p->p_sigqueue.sq_signals; 514 SIGSETNAND(set, td->td_sigmask); 515 if (! SIGISEMPTY(set)) 516 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set); 517 if (SIGPENDING(td)) { 518 mtx_lock_spin(&sched_lock); 519 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 520 mtx_unlock_spin(&sched_lock); 521 } 522 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 523 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 524 /* pending set changed */ 525 p->p_flag |= P_SIGEVENT; 526 wakeup(&p->p_siglist); 527 } 528 } 529 } 530 531 int 532 sigonstack(size_t sp) 533 { 534 struct thread *td = curthread; 535 536 return ((td->td_pflags & TDP_ALTSTACK) ? 537 #if defined(COMPAT_43) 538 ((td->td_sigstk.ss_size == 0) ? 539 (td->td_sigstk.ss_flags & SS_ONSTACK) : 540 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 541 #else 542 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 543 #endif 544 : 0); 545 } 546 547 static __inline int 548 sigprop(int sig) 549 { 550 551 if (sig > 0 && sig < NSIG) 552 return (sigproptbl[_SIG_IDX(sig)]); 553 return (0); 554 } 555 556 int 557 sig_ffs(sigset_t *set) 558 { 559 int i; 560 561 for (i = 0; i < _SIG_WORDS; i++) 562 if (set->__bits[i]) 563 return (ffs(set->__bits[i]) + (i * 32)); 564 return (0); 565 } 566 567 /* 568 * kern_sigaction 569 * sigaction 570 * freebsd4_sigaction 571 * osigaction 572 * 573 * MPSAFE 574 */ 575 int 576 kern_sigaction(td, sig, act, oact, flags) 577 struct thread *td; 578 register int sig; 579 struct sigaction *act, *oact; 580 int flags; 581 { 582 struct sigacts *ps; 583 struct proc *p = td->td_proc; 584 585 if (!_SIG_VALID(sig)) 586 return (EINVAL); 587 588 PROC_LOCK(p); 589 ps = p->p_sigacts; 590 mtx_lock(&ps->ps_mtx); 591 if (oact) { 592 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 593 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 594 oact->sa_flags = 0; 595 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 596 oact->sa_flags |= SA_ONSTACK; 597 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 598 oact->sa_flags |= SA_RESTART; 599 if (SIGISMEMBER(ps->ps_sigreset, sig)) 600 oact->sa_flags |= SA_RESETHAND; 601 if (SIGISMEMBER(ps->ps_signodefer, sig)) 602 oact->sa_flags |= SA_NODEFER; 603 if (SIGISMEMBER(ps->ps_siginfo, sig)) 604 oact->sa_flags |= SA_SIGINFO; 605 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 606 oact->sa_flags |= SA_NOCLDSTOP; 607 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 608 oact->sa_flags |= SA_NOCLDWAIT; 609 } 610 if (act) { 611 if ((sig == SIGKILL || sig == SIGSTOP) && 612 act->sa_handler != SIG_DFL) { 613 mtx_unlock(&ps->ps_mtx); 614 PROC_UNLOCK(p); 615 return (EINVAL); 616 } 617 618 /* 619 * Change setting atomically. 620 */ 621 622 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 623 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 624 if (act->sa_flags & SA_SIGINFO) { 625 ps->ps_sigact[_SIG_IDX(sig)] = 626 (__sighandler_t *)act->sa_sigaction; 627 SIGADDSET(ps->ps_siginfo, sig); 628 } else { 629 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 630 SIGDELSET(ps->ps_siginfo, sig); 631 } 632 if (!(act->sa_flags & SA_RESTART)) 633 SIGADDSET(ps->ps_sigintr, sig); 634 else 635 SIGDELSET(ps->ps_sigintr, sig); 636 if (act->sa_flags & SA_ONSTACK) 637 SIGADDSET(ps->ps_sigonstack, sig); 638 else 639 SIGDELSET(ps->ps_sigonstack, sig); 640 if (act->sa_flags & SA_RESETHAND) 641 SIGADDSET(ps->ps_sigreset, sig); 642 else 643 SIGDELSET(ps->ps_sigreset, sig); 644 if (act->sa_flags & SA_NODEFER) 645 SIGADDSET(ps->ps_signodefer, sig); 646 else 647 SIGDELSET(ps->ps_signodefer, sig); 648 if (sig == SIGCHLD) { 649 if (act->sa_flags & SA_NOCLDSTOP) 650 ps->ps_flag |= PS_NOCLDSTOP; 651 else 652 ps->ps_flag &= ~PS_NOCLDSTOP; 653 if (act->sa_flags & SA_NOCLDWAIT) { 654 /* 655 * Paranoia: since SA_NOCLDWAIT is implemented 656 * by reparenting the dying child to PID 1 (and 657 * trust it to reap the zombie), PID 1 itself 658 * is forbidden to set SA_NOCLDWAIT. 659 */ 660 if (p->p_pid == 1) 661 ps->ps_flag &= ~PS_NOCLDWAIT; 662 else 663 ps->ps_flag |= PS_NOCLDWAIT; 664 } else 665 ps->ps_flag &= ~PS_NOCLDWAIT; 666 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 667 ps->ps_flag |= PS_CLDSIGIGN; 668 else 669 ps->ps_flag &= ~PS_CLDSIGIGN; 670 } 671 /* 672 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 673 * and for signals set to SIG_DFL where the default is to 674 * ignore. However, don't put SIGCONT in ps_sigignore, as we 675 * have to restart the process. 676 */ 677 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 678 (sigprop(sig) & SA_IGNORE && 679 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 680 if ((p->p_flag & P_SA) && 681 SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) { 682 p->p_flag |= P_SIGEVENT; 683 wakeup(&p->p_siglist); 684 } 685 /* never to be seen again */ 686 sigqueue_delete_proc(p, sig); 687 if (sig != SIGCONT) 688 /* easier in psignal */ 689 SIGADDSET(ps->ps_sigignore, sig); 690 SIGDELSET(ps->ps_sigcatch, sig); 691 } else { 692 SIGDELSET(ps->ps_sigignore, sig); 693 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 694 SIGDELSET(ps->ps_sigcatch, sig); 695 else 696 SIGADDSET(ps->ps_sigcatch, sig); 697 } 698 #ifdef COMPAT_FREEBSD4 699 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 700 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 701 (flags & KSA_FREEBSD4) == 0) 702 SIGDELSET(ps->ps_freebsd4, sig); 703 else 704 SIGADDSET(ps->ps_freebsd4, sig); 705 #endif 706 #ifdef COMPAT_43 707 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 708 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 709 (flags & KSA_OSIGSET) == 0) 710 SIGDELSET(ps->ps_osigset, sig); 711 else 712 SIGADDSET(ps->ps_osigset, sig); 713 #endif 714 } 715 mtx_unlock(&ps->ps_mtx); 716 PROC_UNLOCK(p); 717 return (0); 718 } 719 720 #ifndef _SYS_SYSPROTO_H_ 721 struct sigaction_args { 722 int sig; 723 struct sigaction *act; 724 struct sigaction *oact; 725 }; 726 #endif 727 /* 728 * MPSAFE 729 */ 730 int 731 sigaction(td, uap) 732 struct thread *td; 733 register struct sigaction_args *uap; 734 { 735 struct sigaction act, oact; 736 register struct sigaction *actp, *oactp; 737 int error; 738 739 actp = (uap->act != NULL) ? &act : NULL; 740 oactp = (uap->oact != NULL) ? &oact : NULL; 741 if (actp) { 742 error = copyin(uap->act, actp, sizeof(act)); 743 if (error) 744 return (error); 745 } 746 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 747 if (oactp && !error) 748 error = copyout(oactp, uap->oact, sizeof(oact)); 749 return (error); 750 } 751 752 #ifdef COMPAT_FREEBSD4 753 #ifndef _SYS_SYSPROTO_H_ 754 struct freebsd4_sigaction_args { 755 int sig; 756 struct sigaction *act; 757 struct sigaction *oact; 758 }; 759 #endif 760 /* 761 * MPSAFE 762 */ 763 int 764 freebsd4_sigaction(td, uap) 765 struct thread *td; 766 register struct freebsd4_sigaction_args *uap; 767 { 768 struct sigaction act, oact; 769 register struct sigaction *actp, *oactp; 770 int error; 771 772 773 actp = (uap->act != NULL) ? &act : NULL; 774 oactp = (uap->oact != NULL) ? &oact : NULL; 775 if (actp) { 776 error = copyin(uap->act, actp, sizeof(act)); 777 if (error) 778 return (error); 779 } 780 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 781 if (oactp && !error) 782 error = copyout(oactp, uap->oact, sizeof(oact)); 783 return (error); 784 } 785 #endif /* COMAPT_FREEBSD4 */ 786 787 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 788 #ifndef _SYS_SYSPROTO_H_ 789 struct osigaction_args { 790 int signum; 791 struct osigaction *nsa; 792 struct osigaction *osa; 793 }; 794 #endif 795 /* 796 * MPSAFE 797 */ 798 int 799 osigaction(td, uap) 800 struct thread *td; 801 register struct osigaction_args *uap; 802 { 803 struct osigaction sa; 804 struct sigaction nsa, osa; 805 register struct sigaction *nsap, *osap; 806 int error; 807 808 if (uap->signum <= 0 || uap->signum >= ONSIG) 809 return (EINVAL); 810 811 nsap = (uap->nsa != NULL) ? &nsa : NULL; 812 osap = (uap->osa != NULL) ? &osa : NULL; 813 814 if (nsap) { 815 error = copyin(uap->nsa, &sa, sizeof(sa)); 816 if (error) 817 return (error); 818 nsap->sa_handler = sa.sa_handler; 819 nsap->sa_flags = sa.sa_flags; 820 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 821 } 822 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 823 if (osap && !error) { 824 sa.sa_handler = osap->sa_handler; 825 sa.sa_flags = osap->sa_flags; 826 SIG2OSIG(osap->sa_mask, sa.sa_mask); 827 error = copyout(&sa, uap->osa, sizeof(sa)); 828 } 829 return (error); 830 } 831 832 #if !defined(__i386__) && !defined(__alpha__) 833 /* Avoid replicating the same stub everywhere */ 834 int 835 osigreturn(td, uap) 836 struct thread *td; 837 struct osigreturn_args *uap; 838 { 839 840 return (nosys(td, (struct nosys_args *)uap)); 841 } 842 #endif 843 #endif /* COMPAT_43 */ 844 845 /* 846 * Initialize signal state for process 0; 847 * set to ignore signals that are ignored by default. 848 */ 849 void 850 siginit(p) 851 struct proc *p; 852 { 853 register int i; 854 struct sigacts *ps; 855 856 PROC_LOCK(p); 857 ps = p->p_sigacts; 858 mtx_lock(&ps->ps_mtx); 859 for (i = 1; i <= NSIG; i++) 860 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 861 SIGADDSET(ps->ps_sigignore, i); 862 mtx_unlock(&ps->ps_mtx); 863 PROC_UNLOCK(p); 864 } 865 866 /* 867 * Reset signals for an exec of the specified process. 868 */ 869 void 870 execsigs(struct proc *p) 871 { 872 struct sigacts *ps; 873 int sig; 874 struct thread *td; 875 876 /* 877 * Reset caught signals. Held signals remain held 878 * through td_sigmask (unless they were caught, 879 * and are now ignored by default). 880 */ 881 PROC_LOCK_ASSERT(p, MA_OWNED); 882 td = FIRST_THREAD_IN_PROC(p); 883 ps = p->p_sigacts; 884 mtx_lock(&ps->ps_mtx); 885 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 886 sig = sig_ffs(&ps->ps_sigcatch); 887 SIGDELSET(ps->ps_sigcatch, sig); 888 if (sigprop(sig) & SA_IGNORE) { 889 if (sig != SIGCONT) 890 SIGADDSET(ps->ps_sigignore, sig); 891 sigqueue_delete_proc(p, sig); 892 } 893 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 894 } 895 /* 896 * Reset stack state to the user stack. 897 * Clear set of signals caught on the signal stack. 898 */ 899 td->td_sigstk.ss_flags = SS_DISABLE; 900 td->td_sigstk.ss_size = 0; 901 td->td_sigstk.ss_sp = 0; 902 td->td_pflags &= ~TDP_ALTSTACK; 903 /* 904 * Reset no zombies if child dies flag as Solaris does. 905 */ 906 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 907 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 908 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 909 mtx_unlock(&ps->ps_mtx); 910 } 911 912 /* 913 * kern_sigprocmask() 914 * 915 * Manipulate signal mask. 916 */ 917 int 918 kern_sigprocmask(td, how, set, oset, old) 919 struct thread *td; 920 int how; 921 sigset_t *set, *oset; 922 int old; 923 { 924 int error; 925 926 PROC_LOCK(td->td_proc); 927 if (oset != NULL) 928 *oset = td->td_sigmask; 929 930 error = 0; 931 if (set != NULL) { 932 switch (how) { 933 case SIG_BLOCK: 934 SIG_CANTMASK(*set); 935 SIGSETOR(td->td_sigmask, *set); 936 break; 937 case SIG_UNBLOCK: 938 SIGSETNAND(td->td_sigmask, *set); 939 signotify(td); 940 break; 941 case SIG_SETMASK: 942 SIG_CANTMASK(*set); 943 if (old) 944 SIGSETLO(td->td_sigmask, *set); 945 else 946 td->td_sigmask = *set; 947 signotify(td); 948 break; 949 default: 950 error = EINVAL; 951 break; 952 } 953 } 954 PROC_UNLOCK(td->td_proc); 955 return (error); 956 } 957 958 /* 959 * sigprocmask() - MP SAFE 960 */ 961 962 #ifndef _SYS_SYSPROTO_H_ 963 struct sigprocmask_args { 964 int how; 965 const sigset_t *set; 966 sigset_t *oset; 967 }; 968 #endif 969 int 970 sigprocmask(td, uap) 971 register struct thread *td; 972 struct sigprocmask_args *uap; 973 { 974 sigset_t set, oset; 975 sigset_t *setp, *osetp; 976 int error; 977 978 setp = (uap->set != NULL) ? &set : NULL; 979 osetp = (uap->oset != NULL) ? &oset : NULL; 980 if (setp) { 981 error = copyin(uap->set, setp, sizeof(set)); 982 if (error) 983 return (error); 984 } 985 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 986 if (osetp && !error) { 987 error = copyout(osetp, uap->oset, sizeof(oset)); 988 } 989 return (error); 990 } 991 992 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 993 /* 994 * osigprocmask() - MP SAFE 995 */ 996 #ifndef _SYS_SYSPROTO_H_ 997 struct osigprocmask_args { 998 int how; 999 osigset_t mask; 1000 }; 1001 #endif 1002 int 1003 osigprocmask(td, uap) 1004 register struct thread *td; 1005 struct osigprocmask_args *uap; 1006 { 1007 sigset_t set, oset; 1008 int error; 1009 1010 OSIG2SIG(uap->mask, set); 1011 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1012 SIG2OSIG(oset, td->td_retval[0]); 1013 return (error); 1014 } 1015 #endif /* COMPAT_43 */ 1016 1017 /* 1018 * MPSAFE 1019 */ 1020 int 1021 sigwait(struct thread *td, struct sigwait_args *uap) 1022 { 1023 ksiginfo_t ksi; 1024 sigset_t set; 1025 int error; 1026 1027 error = copyin(uap->set, &set, sizeof(set)); 1028 if (error) { 1029 td->td_retval[0] = error; 1030 return (0); 1031 } 1032 1033 error = kern_sigtimedwait(td, set, &ksi, NULL); 1034 if (error) { 1035 if (error == ERESTART) 1036 return (error); 1037 td->td_retval[0] = error; 1038 return (0); 1039 } 1040 1041 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1042 td->td_retval[0] = error; 1043 return (0); 1044 } 1045 /* 1046 * MPSAFE 1047 */ 1048 int 1049 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1050 { 1051 struct timespec ts; 1052 struct timespec *timeout; 1053 sigset_t set; 1054 ksiginfo_t ksi; 1055 int error; 1056 1057 if (uap->timeout) { 1058 error = copyin(uap->timeout, &ts, sizeof(ts)); 1059 if (error) 1060 return (error); 1061 1062 timeout = &ts; 1063 } else 1064 timeout = NULL; 1065 1066 error = copyin(uap->set, &set, sizeof(set)); 1067 if (error) 1068 return (error); 1069 1070 error = kern_sigtimedwait(td, set, &ksi, timeout); 1071 if (error) 1072 return (error); 1073 1074 if (uap->info) 1075 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1076 1077 if (error == 0) 1078 td->td_retval[0] = ksi.ksi_signo; 1079 return (error); 1080 } 1081 1082 /* 1083 * MPSAFE 1084 */ 1085 int 1086 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1087 { 1088 ksiginfo_t ksi; 1089 sigset_t set; 1090 int error; 1091 1092 error = copyin(uap->set, &set, sizeof(set)); 1093 if (error) 1094 return (error); 1095 1096 error = kern_sigtimedwait(td, set, &ksi, NULL); 1097 if (error) 1098 return (error); 1099 1100 if (uap->info) 1101 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1102 1103 if (error == 0) 1104 td->td_retval[0] = ksi.ksi_signo; 1105 return (error); 1106 } 1107 1108 static int 1109 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1110 struct timespec *timeout) 1111 { 1112 struct sigacts *ps; 1113 sigset_t savedmask; 1114 struct proc *p; 1115 int error, sig, hz, i, timevalid = 0; 1116 struct timespec rts, ets, ts; 1117 struct timeval tv; 1118 1119 p = td->td_proc; 1120 error = 0; 1121 sig = 0; 1122 SIG_CANTMASK(waitset); 1123 1124 PROC_LOCK(p); 1125 ps = p->p_sigacts; 1126 savedmask = td->td_sigmask; 1127 if (timeout) { 1128 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1129 timevalid = 1; 1130 getnanouptime(&rts); 1131 ets = rts; 1132 timespecadd(&ets, timeout); 1133 } 1134 } 1135 1136 again: 1137 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1138 if (!SIGISMEMBER(waitset, i)) 1139 continue; 1140 if (SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1141 SIGFILLSET(td->td_sigmask); 1142 SIG_CANTMASK(td->td_sigmask); 1143 SIGDELSET(td->td_sigmask, i); 1144 mtx_lock(&ps->ps_mtx); 1145 sig = cursig(td); 1146 i = 0; 1147 mtx_unlock(&ps->ps_mtx); 1148 } else if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1149 if (p->p_flag & P_SA) { 1150 p->p_flag |= P_SIGEVENT; 1151 wakeup(&p->p_siglist); 1152 } 1153 sigqueue_move(&p->p_sigqueue, &td->td_sigqueue, i); 1154 SIGFILLSET(td->td_sigmask); 1155 SIG_CANTMASK(td->td_sigmask); 1156 SIGDELSET(td->td_sigmask, i); 1157 mtx_lock(&ps->ps_mtx); 1158 sig = cursig(td); 1159 i = 0; 1160 mtx_unlock(&ps->ps_mtx); 1161 } 1162 if (sig) 1163 goto out; 1164 } 1165 if (error) 1166 goto out; 1167 1168 /* 1169 * POSIX says this must be checked after looking for pending 1170 * signals. 1171 */ 1172 if (timeout) { 1173 if (!timevalid) { 1174 error = EINVAL; 1175 goto out; 1176 } 1177 getnanouptime(&rts); 1178 if (timespeccmp(&rts, &ets, >=)) { 1179 error = EAGAIN; 1180 goto out; 1181 } 1182 ts = ets; 1183 timespecsub(&ts, &rts); 1184 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1185 hz = tvtohz(&tv); 1186 } else 1187 hz = 0; 1188 1189 td->td_sigmask = savedmask; 1190 SIGSETNAND(td->td_sigmask, waitset); 1191 signotify(td); 1192 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1193 if (timeout) { 1194 if (error == ERESTART) { 1195 /* timeout can not be restarted. */ 1196 error = EINTR; 1197 } else if (error == EAGAIN) { 1198 /* will calculate timeout by ourself. */ 1199 error = 0; 1200 } 1201 } 1202 goto again; 1203 1204 out: 1205 if (sig) { 1206 sig_t action; 1207 1208 sigqueue_get(&td->td_sigqueue, sig, ksi); 1209 ksi->ksi_signo = sig; 1210 error = 0; 1211 mtx_lock(&ps->ps_mtx); 1212 action = ps->ps_sigact[_SIG_IDX(sig)]; 1213 mtx_unlock(&ps->ps_mtx); 1214 #ifdef KTRACE 1215 if (KTRPOINT(td, KTR_PSIG)) 1216 ktrpsig(sig, action, &td->td_sigmask, 0); 1217 #endif 1218 _STOPEVENT(p, S_SIG, sig); 1219 1220 } 1221 td->td_sigmask = savedmask; 1222 signotify(td); 1223 PROC_UNLOCK(p); 1224 return (error); 1225 } 1226 1227 #ifndef _SYS_SYSPROTO_H_ 1228 struct sigpending_args { 1229 sigset_t *set; 1230 }; 1231 #endif 1232 /* 1233 * MPSAFE 1234 */ 1235 int 1236 sigpending(td, uap) 1237 struct thread *td; 1238 struct sigpending_args *uap; 1239 { 1240 struct proc *p = td->td_proc; 1241 sigset_t pending; 1242 1243 PROC_LOCK(p); 1244 pending = p->p_sigqueue.sq_signals; 1245 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1246 PROC_UNLOCK(p); 1247 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1248 } 1249 1250 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1251 #ifndef _SYS_SYSPROTO_H_ 1252 struct osigpending_args { 1253 int dummy; 1254 }; 1255 #endif 1256 /* 1257 * MPSAFE 1258 */ 1259 int 1260 osigpending(td, uap) 1261 struct thread *td; 1262 struct osigpending_args *uap; 1263 { 1264 struct proc *p = td->td_proc; 1265 sigset_t pending; 1266 1267 PROC_LOCK(p); 1268 pending = p->p_sigqueue.sq_signals; 1269 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1270 PROC_UNLOCK(p); 1271 SIG2OSIG(pending, td->td_retval[0]); 1272 return (0); 1273 } 1274 #endif /* COMPAT_43 */ 1275 1276 #if defined(COMPAT_43) 1277 /* 1278 * Generalized interface signal handler, 4.3-compatible. 1279 */ 1280 #ifndef _SYS_SYSPROTO_H_ 1281 struct osigvec_args { 1282 int signum; 1283 struct sigvec *nsv; 1284 struct sigvec *osv; 1285 }; 1286 #endif 1287 /* 1288 * MPSAFE 1289 */ 1290 /* ARGSUSED */ 1291 int 1292 osigvec(td, uap) 1293 struct thread *td; 1294 register struct osigvec_args *uap; 1295 { 1296 struct sigvec vec; 1297 struct sigaction nsa, osa; 1298 register struct sigaction *nsap, *osap; 1299 int error; 1300 1301 if (uap->signum <= 0 || uap->signum >= ONSIG) 1302 return (EINVAL); 1303 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1304 osap = (uap->osv != NULL) ? &osa : NULL; 1305 if (nsap) { 1306 error = copyin(uap->nsv, &vec, sizeof(vec)); 1307 if (error) 1308 return (error); 1309 nsap->sa_handler = vec.sv_handler; 1310 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1311 nsap->sa_flags = vec.sv_flags; 1312 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1313 } 1314 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1315 if (osap && !error) { 1316 vec.sv_handler = osap->sa_handler; 1317 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1318 vec.sv_flags = osap->sa_flags; 1319 vec.sv_flags &= ~SA_NOCLDWAIT; 1320 vec.sv_flags ^= SA_RESTART; 1321 error = copyout(&vec, uap->osv, sizeof(vec)); 1322 } 1323 return (error); 1324 } 1325 1326 #ifndef _SYS_SYSPROTO_H_ 1327 struct osigblock_args { 1328 int mask; 1329 }; 1330 #endif 1331 /* 1332 * MPSAFE 1333 */ 1334 int 1335 osigblock(td, uap) 1336 register struct thread *td; 1337 struct osigblock_args *uap; 1338 { 1339 struct proc *p = td->td_proc; 1340 sigset_t set; 1341 1342 OSIG2SIG(uap->mask, set); 1343 SIG_CANTMASK(set); 1344 PROC_LOCK(p); 1345 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1346 SIGSETOR(td->td_sigmask, set); 1347 PROC_UNLOCK(p); 1348 return (0); 1349 } 1350 1351 #ifndef _SYS_SYSPROTO_H_ 1352 struct osigsetmask_args { 1353 int mask; 1354 }; 1355 #endif 1356 /* 1357 * MPSAFE 1358 */ 1359 int 1360 osigsetmask(td, uap) 1361 struct thread *td; 1362 struct osigsetmask_args *uap; 1363 { 1364 struct proc *p = td->td_proc; 1365 sigset_t set; 1366 1367 OSIG2SIG(uap->mask, set); 1368 SIG_CANTMASK(set); 1369 PROC_LOCK(p); 1370 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1371 SIGSETLO(td->td_sigmask, set); 1372 signotify(td); 1373 PROC_UNLOCK(p); 1374 return (0); 1375 } 1376 #endif /* COMPAT_43 */ 1377 1378 /* 1379 * Suspend calling thread until signal, providing mask to be set 1380 * in the meantime. 1381 */ 1382 #ifndef _SYS_SYSPROTO_H_ 1383 struct sigsuspend_args { 1384 const sigset_t *sigmask; 1385 }; 1386 #endif 1387 /* 1388 * MPSAFE 1389 */ 1390 /* ARGSUSED */ 1391 int 1392 sigsuspend(td, uap) 1393 struct thread *td; 1394 struct sigsuspend_args *uap; 1395 { 1396 sigset_t mask; 1397 int error; 1398 1399 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1400 if (error) 1401 return (error); 1402 return (kern_sigsuspend(td, mask)); 1403 } 1404 1405 int 1406 kern_sigsuspend(struct thread *td, sigset_t mask) 1407 { 1408 struct proc *p = td->td_proc; 1409 1410 /* 1411 * When returning from sigsuspend, we want 1412 * the old mask to be restored after the 1413 * signal handler has finished. Thus, we 1414 * save it here and mark the sigacts structure 1415 * to indicate this. 1416 */ 1417 PROC_LOCK(p); 1418 td->td_oldsigmask = td->td_sigmask; 1419 td->td_pflags |= TDP_OLDMASK; 1420 SIG_CANTMASK(mask); 1421 td->td_sigmask = mask; 1422 signotify(td); 1423 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1424 /* void */; 1425 PROC_UNLOCK(p); 1426 /* always return EINTR rather than ERESTART... */ 1427 return (EINTR); 1428 } 1429 1430 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1431 /* 1432 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1433 * convention: libc stub passes mask, not pointer, to save a copyin. 1434 */ 1435 #ifndef _SYS_SYSPROTO_H_ 1436 struct osigsuspend_args { 1437 osigset_t mask; 1438 }; 1439 #endif 1440 /* 1441 * MPSAFE 1442 */ 1443 /* ARGSUSED */ 1444 int 1445 osigsuspend(td, uap) 1446 struct thread *td; 1447 struct osigsuspend_args *uap; 1448 { 1449 struct proc *p = td->td_proc; 1450 sigset_t mask; 1451 1452 PROC_LOCK(p); 1453 td->td_oldsigmask = td->td_sigmask; 1454 td->td_pflags |= TDP_OLDMASK; 1455 OSIG2SIG(uap->mask, mask); 1456 SIG_CANTMASK(mask); 1457 SIGSETLO(td->td_sigmask, mask); 1458 signotify(td); 1459 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1460 /* void */; 1461 PROC_UNLOCK(p); 1462 /* always return EINTR rather than ERESTART... */ 1463 return (EINTR); 1464 } 1465 #endif /* COMPAT_43 */ 1466 1467 #if defined(COMPAT_43) 1468 #ifndef _SYS_SYSPROTO_H_ 1469 struct osigstack_args { 1470 struct sigstack *nss; 1471 struct sigstack *oss; 1472 }; 1473 #endif 1474 /* 1475 * MPSAFE 1476 */ 1477 /* ARGSUSED */ 1478 int 1479 osigstack(td, uap) 1480 struct thread *td; 1481 register struct osigstack_args *uap; 1482 { 1483 struct sigstack nss, oss; 1484 int error = 0; 1485 1486 if (uap->nss != NULL) { 1487 error = copyin(uap->nss, &nss, sizeof(nss)); 1488 if (error) 1489 return (error); 1490 } 1491 oss.ss_sp = td->td_sigstk.ss_sp; 1492 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1493 if (uap->nss != NULL) { 1494 td->td_sigstk.ss_sp = nss.ss_sp; 1495 td->td_sigstk.ss_size = 0; 1496 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1497 td->td_pflags |= TDP_ALTSTACK; 1498 } 1499 if (uap->oss != NULL) 1500 error = copyout(&oss, uap->oss, sizeof(oss)); 1501 1502 return (error); 1503 } 1504 #endif /* COMPAT_43 */ 1505 1506 #ifndef _SYS_SYSPROTO_H_ 1507 struct sigaltstack_args { 1508 stack_t *ss; 1509 stack_t *oss; 1510 }; 1511 #endif 1512 /* 1513 * MPSAFE 1514 */ 1515 /* ARGSUSED */ 1516 int 1517 sigaltstack(td, uap) 1518 struct thread *td; 1519 register struct sigaltstack_args *uap; 1520 { 1521 stack_t ss, oss; 1522 int error; 1523 1524 if (uap->ss != NULL) { 1525 error = copyin(uap->ss, &ss, sizeof(ss)); 1526 if (error) 1527 return (error); 1528 } 1529 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1530 (uap->oss != NULL) ? &oss : NULL); 1531 if (error) 1532 return (error); 1533 if (uap->oss != NULL) 1534 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1535 return (error); 1536 } 1537 1538 int 1539 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1540 { 1541 struct proc *p = td->td_proc; 1542 int oonstack; 1543 1544 oonstack = sigonstack(cpu_getstack(td)); 1545 1546 if (oss != NULL) { 1547 *oss = td->td_sigstk; 1548 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1549 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1550 } 1551 1552 if (ss != NULL) { 1553 if (oonstack) 1554 return (EPERM); 1555 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1556 return (EINVAL); 1557 if (!(ss->ss_flags & SS_DISABLE)) { 1558 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1559 return (ENOMEM); 1560 1561 td->td_sigstk = *ss; 1562 td->td_pflags |= TDP_ALTSTACK; 1563 } else { 1564 td->td_pflags &= ~TDP_ALTSTACK; 1565 } 1566 } 1567 return (0); 1568 } 1569 1570 /* 1571 * Common code for kill process group/broadcast kill. 1572 * cp is calling process. 1573 */ 1574 static int 1575 killpg1(td, sig, pgid, all) 1576 register struct thread *td; 1577 int sig, pgid, all; 1578 { 1579 register struct proc *p; 1580 struct pgrp *pgrp; 1581 int nfound = 0; 1582 1583 if (all) { 1584 /* 1585 * broadcast 1586 */ 1587 sx_slock(&allproc_lock); 1588 LIST_FOREACH(p, &allproc, p_list) { 1589 PROC_LOCK(p); 1590 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1591 p == td->td_proc) { 1592 PROC_UNLOCK(p); 1593 continue; 1594 } 1595 if (p_cansignal(td, p, sig) == 0) { 1596 nfound++; 1597 if (sig) 1598 psignal(p, sig); 1599 } 1600 PROC_UNLOCK(p); 1601 } 1602 sx_sunlock(&allproc_lock); 1603 } else { 1604 sx_slock(&proctree_lock); 1605 if (pgid == 0) { 1606 /* 1607 * zero pgid means send to my process group. 1608 */ 1609 pgrp = td->td_proc->p_pgrp; 1610 PGRP_LOCK(pgrp); 1611 } else { 1612 pgrp = pgfind(pgid); 1613 if (pgrp == NULL) { 1614 sx_sunlock(&proctree_lock); 1615 return (ESRCH); 1616 } 1617 } 1618 sx_sunlock(&proctree_lock); 1619 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1620 PROC_LOCK(p); 1621 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM) { 1622 PROC_UNLOCK(p); 1623 continue; 1624 } 1625 if (p_cansignal(td, p, sig) == 0) { 1626 nfound++; 1627 if (sig) 1628 psignal(p, sig); 1629 } 1630 PROC_UNLOCK(p); 1631 } 1632 PGRP_UNLOCK(pgrp); 1633 } 1634 return (nfound ? 0 : ESRCH); 1635 } 1636 1637 #ifndef _SYS_SYSPROTO_H_ 1638 struct kill_args { 1639 int pid; 1640 int signum; 1641 }; 1642 #endif 1643 /* 1644 * MPSAFE 1645 */ 1646 /* ARGSUSED */ 1647 int 1648 kill(td, uap) 1649 register struct thread *td; 1650 register struct kill_args *uap; 1651 { 1652 register struct proc *p; 1653 int error; 1654 1655 if ((u_int)uap->signum > _SIG_MAXSIG) 1656 return (EINVAL); 1657 1658 if (uap->pid > 0) { 1659 /* kill single process */ 1660 if ((p = pfind(uap->pid)) == NULL) { 1661 if ((p = zpfind(uap->pid)) == NULL) 1662 return (ESRCH); 1663 } 1664 error = p_cansignal(td, p, uap->signum); 1665 if (error == 0 && uap->signum) 1666 psignal(p, uap->signum); 1667 PROC_UNLOCK(p); 1668 return (error); 1669 } 1670 switch (uap->pid) { 1671 case -1: /* broadcast signal */ 1672 return (killpg1(td, uap->signum, 0, 1)); 1673 case 0: /* signal own process group */ 1674 return (killpg1(td, uap->signum, 0, 0)); 1675 default: /* negative explicit process group */ 1676 return (killpg1(td, uap->signum, -uap->pid, 0)); 1677 } 1678 /* NOTREACHED */ 1679 } 1680 1681 #if defined(COMPAT_43) 1682 #ifndef _SYS_SYSPROTO_H_ 1683 struct okillpg_args { 1684 int pgid; 1685 int signum; 1686 }; 1687 #endif 1688 /* 1689 * MPSAFE 1690 */ 1691 /* ARGSUSED */ 1692 int 1693 okillpg(td, uap) 1694 struct thread *td; 1695 register struct okillpg_args *uap; 1696 { 1697 1698 if ((u_int)uap->signum > _SIG_MAXSIG) 1699 return (EINVAL); 1700 1701 return (killpg1(td, uap->signum, uap->pgid, 0)); 1702 } 1703 #endif /* COMPAT_43 */ 1704 1705 #ifndef _SYS_SYSPROTO_H_ 1706 struct sigqueue_args { 1707 pid_t pid; 1708 int signum; 1709 /* union sigval */ void *value; 1710 }; 1711 #endif 1712 1713 int 1714 sigqueue(struct thread *td, struct sigqueue_args *uap) 1715 { 1716 ksiginfo_t ksi; 1717 struct proc *p; 1718 int error; 1719 1720 if ((u_int)uap->signum > _SIG_MAXSIG) 1721 return (EINVAL); 1722 1723 /* 1724 * Specification says sigqueue can only send signal to 1725 * single process. 1726 */ 1727 if (uap->pid <= 0) 1728 return (EINVAL); 1729 1730 if ((p = pfind(uap->pid)) == NULL) { 1731 if ((p = zpfind(uap->pid)) == NULL) 1732 return (ESRCH); 1733 } 1734 error = p_cansignal(td, p, uap->signum); 1735 if (error == 0 && uap->signum != 0) { 1736 ksiginfo_init(&ksi); 1737 ksi.ksi_signo = uap->signum; 1738 ksi.ksi_code = SI_QUEUE; 1739 ksi.ksi_pid = td->td_proc->p_pid; 1740 ksi.ksi_uid = td->td_ucred->cr_ruid; 1741 ksi.ksi_value.sigval_ptr = uap->value; 1742 error = psignal_info(p, &ksi); 1743 } 1744 PROC_UNLOCK(p); 1745 return (error); 1746 } 1747 1748 /* 1749 * Send a signal to a process group. 1750 */ 1751 void 1752 gsignal(pgid, sig) 1753 int pgid, sig; 1754 { 1755 struct pgrp *pgrp; 1756 1757 if (pgid != 0) { 1758 sx_slock(&proctree_lock); 1759 pgrp = pgfind(pgid); 1760 sx_sunlock(&proctree_lock); 1761 if (pgrp != NULL) { 1762 pgsignal(pgrp, sig, 0); 1763 PGRP_UNLOCK(pgrp); 1764 } 1765 } 1766 } 1767 1768 /* 1769 * Send a signal to a process group. If checktty is 1, 1770 * limit to members which have a controlling terminal. 1771 */ 1772 void 1773 pgsignal(pgrp, sig, checkctty) 1774 struct pgrp *pgrp; 1775 int sig, checkctty; 1776 { 1777 register struct proc *p; 1778 1779 if (pgrp) { 1780 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1781 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1782 PROC_LOCK(p); 1783 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1784 psignal(p, sig); 1785 PROC_UNLOCK(p); 1786 } 1787 } 1788 } 1789 1790 /* 1791 * Send a signal caused by a trap to the current thread. 1792 * If it will be caught immediately, deliver it with correct code. 1793 * Otherwise, post it normally. 1794 * 1795 * MPSAFE 1796 */ 1797 void 1798 trapsignal(struct thread *td, ksiginfo_t *ksi) 1799 { 1800 struct sigacts *ps; 1801 struct proc *p; 1802 int error; 1803 int sig; 1804 int code; 1805 1806 p = td->td_proc; 1807 sig = ksi->ksi_signo; 1808 code = ksi->ksi_code; 1809 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1810 1811 if (td->td_pflags & TDP_SA) { 1812 if (td->td_mailbox == NULL) 1813 thread_user_enter(td); 1814 PROC_LOCK(p); 1815 SIGDELSET(td->td_sigmask, sig); 1816 mtx_lock_spin(&sched_lock); 1817 /* 1818 * Force scheduling an upcall, so UTS has chance to 1819 * process the signal before thread runs again in 1820 * userland. 1821 */ 1822 if (td->td_upcall) 1823 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1824 mtx_unlock_spin(&sched_lock); 1825 } else { 1826 PROC_LOCK(p); 1827 } 1828 ps = p->p_sigacts; 1829 mtx_lock(&ps->ps_mtx); 1830 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1831 !SIGISMEMBER(td->td_sigmask, sig)) { 1832 p->p_stats->p_ru.ru_nsignals++; 1833 #ifdef KTRACE 1834 if (KTRPOINT(curthread, KTR_PSIG)) 1835 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1836 &td->td_sigmask, code); 1837 #endif 1838 if (!(td->td_pflags & TDP_SA)) 1839 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1840 ksi, &td->td_sigmask); 1841 else if (td->td_mailbox == NULL) { 1842 mtx_unlock(&ps->ps_mtx); 1843 /* UTS caused a sync signal */ 1844 p->p_code = code; /* XXX for core dump/debugger */ 1845 p->p_sig = sig; /* XXX to verify code */ 1846 sigexit(td, sig); 1847 } else { 1848 mtx_unlock(&ps->ps_mtx); 1849 SIGADDSET(td->td_sigmask, sig); 1850 PROC_UNLOCK(p); 1851 error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig, 1852 sizeof(siginfo_t)); 1853 PROC_LOCK(p); 1854 /* UTS memory corrupted */ 1855 if (error) 1856 sigexit(td, SIGSEGV); 1857 mtx_lock(&ps->ps_mtx); 1858 } 1859 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1860 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1861 SIGADDSET(td->td_sigmask, sig); 1862 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1863 /* 1864 * See kern_sigaction() for origin of this code. 1865 */ 1866 SIGDELSET(ps->ps_sigcatch, sig); 1867 if (sig != SIGCONT && 1868 sigprop(sig) & SA_IGNORE) 1869 SIGADDSET(ps->ps_sigignore, sig); 1870 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1871 } 1872 mtx_unlock(&ps->ps_mtx); 1873 } else { 1874 mtx_unlock(&ps->ps_mtx); 1875 p->p_code = code; /* XXX for core dump/debugger */ 1876 p->p_sig = sig; /* XXX to verify code */ 1877 tdsignal(td, sig, ksi, SIGTARGET_TD); 1878 } 1879 PROC_UNLOCK(p); 1880 } 1881 1882 static struct thread * 1883 sigtd(struct proc *p, int sig, int prop) 1884 { 1885 struct thread *td, *signal_td; 1886 1887 PROC_LOCK_ASSERT(p, MA_OWNED); 1888 1889 /* 1890 * Check if current thread can handle the signal without 1891 * switching conetxt to another thread. 1892 */ 1893 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1894 return (curthread); 1895 signal_td = NULL; 1896 mtx_lock_spin(&sched_lock); 1897 FOREACH_THREAD_IN_PROC(p, td) { 1898 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1899 signal_td = td; 1900 break; 1901 } 1902 } 1903 if (signal_td == NULL) 1904 signal_td = FIRST_THREAD_IN_PROC(p); 1905 mtx_unlock_spin(&sched_lock); 1906 return (signal_td); 1907 } 1908 1909 /* 1910 * Send the signal to the process. If the signal has an action, the action 1911 * is usually performed by the target process rather than the caller; we add 1912 * the signal to the set of pending signals for the process. 1913 * 1914 * Exceptions: 1915 * o When a stop signal is sent to a sleeping process that takes the 1916 * default action, the process is stopped without awakening it. 1917 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1918 * regardless of the signal action (eg, blocked or ignored). 1919 * 1920 * Other ignored signals are discarded immediately. 1921 * 1922 * MPSAFE 1923 */ 1924 void 1925 psignal(struct proc *p, int sig) 1926 { 1927 (void) psignal_common(p, sig, NULL); 1928 } 1929 1930 int 1931 psignal_info(struct proc *p, ksiginfo_t *ksi) 1932 { 1933 return (psignal_common(p, ksi->ksi_signo, ksi)); 1934 } 1935 1936 static int 1937 psignal_common(struct proc *p, int sig, ksiginfo_t *ksi) 1938 { 1939 struct thread *td; 1940 int prop; 1941 1942 if (!_SIG_VALID(sig)) 1943 panic("psignal(): invalid signal"); 1944 1945 PROC_LOCK_ASSERT(p, MA_OWNED); 1946 /* 1947 * IEEE Std 1003.1-2001: return success when killing a zombie. 1948 */ 1949 if (p->p_state == PRS_ZOMBIE) 1950 return (0); 1951 prop = sigprop(sig); 1952 1953 /* 1954 * Find a thread to deliver the signal to. 1955 */ 1956 td = sigtd(p, sig, prop); 1957 1958 return (tdsignal(td, sig, ksi, SIGTARGET_P)); 1959 } 1960 1961 /* 1962 * MPSAFE 1963 */ 1964 int 1965 tdsignal(struct thread *td, int sig, ksiginfo_t *ksi, sigtarget_t target) 1966 { 1967 sigset_t saved; 1968 struct proc *p = td->td_proc; 1969 int ret; 1970 1971 if (p->p_flag & P_SA) 1972 saved = p->p_sigqueue.sq_signals; 1973 ret = do_tdsignal(td, sig, ksi, target); 1974 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 1975 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 1976 /* pending set changed */ 1977 p->p_flag |= P_SIGEVENT; 1978 wakeup(&p->p_siglist); 1979 } 1980 } 1981 return (ret); 1982 } 1983 1984 static int 1985 do_tdsignal(struct thread *td, int sig, ksiginfo_t *ksi, sigtarget_t target) 1986 { 1987 struct proc *p; 1988 sig_t action; 1989 sigqueue_t *sigqueue; 1990 struct thread *td0; 1991 int prop; 1992 struct sigacts *ps; 1993 int ret = 0; 1994 1995 if (!_SIG_VALID(sig)) 1996 panic("do_tdsignal(): invalid signal"); 1997 1998 p = td->td_proc; 1999 ps = p->p_sigacts; 2000 2001 PROC_LOCK_ASSERT(p, MA_OWNED); 2002 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2003 2004 prop = sigprop(sig); 2005 2006 /* 2007 * If the signal is blocked and not destined for this thread, then 2008 * assign it to the process so that we can find it later in the first 2009 * thread that unblocks it. Otherwise, assign it to this thread now. 2010 */ 2011 if (target == SIGTARGET_TD) { 2012 sigqueue = &td->td_sigqueue; 2013 } else { 2014 if (!SIGISMEMBER(td->td_sigmask, sig)) 2015 sigqueue = &td->td_sigqueue; 2016 else 2017 sigqueue = &p->p_sigqueue; 2018 } 2019 2020 /* 2021 * If the signal is being ignored, 2022 * or process is exiting or thread is exiting, 2023 * then we forget about it immediately. 2024 * (Note: we don't set SIGCONT in ps_sigignore, 2025 * and if it is set to SIG_IGN, 2026 * action will be SIG_DFL here.) 2027 */ 2028 mtx_lock(&ps->ps_mtx); 2029 if (SIGISMEMBER(ps->ps_sigignore, sig) || 2030 (p->p_flag & P_WEXIT)) { 2031 mtx_unlock(&ps->ps_mtx); 2032 return (ret); 2033 } 2034 if (SIGISMEMBER(td->td_sigmask, sig)) 2035 action = SIG_HOLD; 2036 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2037 action = SIG_CATCH; 2038 else 2039 action = SIG_DFL; 2040 mtx_unlock(&ps->ps_mtx); 2041 2042 if (prop & SA_CONT) 2043 sigqueue_delete_stopmask_proc(p); 2044 else if (prop & SA_STOP) { 2045 /* 2046 * If sending a tty stop signal to a member of an orphaned 2047 * process group, discard the signal here if the action 2048 * is default; don't stop the process below if sleeping, 2049 * and don't clear any pending SIGCONT. 2050 */ 2051 if ((prop & SA_TTYSTOP) && 2052 (p->p_pgrp->pg_jobc == 0) && 2053 (action == SIG_DFL)) 2054 return (ret); 2055 sigqueue_delete_proc(p, SIGCONT); 2056 p->p_flag &= ~P_CONTINUED; 2057 } 2058 2059 ret = sigqueue_add(sigqueue, sig, ksi); 2060 if (ret != 0) 2061 return (ret); 2062 signotify(td); /* uses schedlock */ 2063 /* 2064 * Defer further processing for signals which are held, 2065 * except that stopped processes must be continued by SIGCONT. 2066 */ 2067 if (action == SIG_HOLD && 2068 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2069 return (ret); 2070 /* 2071 * SIGKILL: Remove procfs STOPEVENTs. 2072 */ 2073 if (sig == SIGKILL) { 2074 /* from procfs_ioctl.c: PIOCBIC */ 2075 p->p_stops = 0; 2076 /* from procfs_ioctl.c: PIOCCONT */ 2077 p->p_step = 0; 2078 wakeup(&p->p_step); 2079 } 2080 /* 2081 * Some signals have a process-wide effect and a per-thread 2082 * component. Most processing occurs when the process next 2083 * tries to cross the user boundary, however there are some 2084 * times when processing needs to be done immediatly, such as 2085 * waking up threads so that they can cross the user boundary. 2086 * We try do the per-process part here. 2087 */ 2088 if (P_SHOULDSTOP(p)) { 2089 /* 2090 * The process is in stopped mode. All the threads should be 2091 * either winding down or already on the suspended queue. 2092 */ 2093 if (p->p_flag & P_TRACED) { 2094 /* 2095 * The traced process is already stopped, 2096 * so no further action is necessary. 2097 * No signal can restart us. 2098 */ 2099 goto out; 2100 } 2101 2102 if (sig == SIGKILL) { 2103 /* 2104 * SIGKILL sets process running. 2105 * It will die elsewhere. 2106 * All threads must be restarted. 2107 */ 2108 p->p_flag &= ~P_STOPPED_SIG; 2109 goto runfast; 2110 } 2111 2112 if (prop & SA_CONT) { 2113 /* 2114 * If SIGCONT is default (or ignored), we continue the 2115 * process but don't leave the signal in sigqueue as 2116 * it has no further action. If SIGCONT is held, we 2117 * continue the process and leave the signal in 2118 * sigqueue. If the process catches SIGCONT, let it 2119 * handle the signal itself. If it isn't waiting on 2120 * an event, it goes back to run state. 2121 * Otherwise, process goes back to sleep state. 2122 */ 2123 p->p_flag &= ~P_STOPPED_SIG; 2124 p->p_flag |= P_CONTINUED; 2125 if (action == SIG_DFL) { 2126 sigqueue_delete(sigqueue, sig); 2127 } else if (action == SIG_CATCH) { 2128 /* 2129 * The process wants to catch it so it needs 2130 * to run at least one thread, but which one? 2131 * It would seem that the answer would be to 2132 * run an upcall in the next KSE to run, and 2133 * deliver the signal that way. In a NON KSE 2134 * process, we need to make sure that the 2135 * single thread is runnable asap. 2136 * XXXKSE for now however, make them all run. 2137 */ 2138 goto runfast; 2139 } 2140 /* 2141 * The signal is not ignored or caught. 2142 */ 2143 mtx_lock_spin(&sched_lock); 2144 thread_unsuspend(p); 2145 mtx_unlock_spin(&sched_lock); 2146 goto out; 2147 } 2148 2149 if (prop & SA_STOP) { 2150 /* 2151 * Already stopped, don't need to stop again 2152 * (If we did the shell could get confused). 2153 * Just make sure the signal STOP bit set. 2154 */ 2155 p->p_flag |= P_STOPPED_SIG; 2156 sigqueue_delete(sigqueue, sig); 2157 goto out; 2158 } 2159 2160 /* 2161 * All other kinds of signals: 2162 * If a thread is sleeping interruptibly, simulate a 2163 * wakeup so that when it is continued it will be made 2164 * runnable and can look at the signal. However, don't make 2165 * the PROCESS runnable, leave it stopped. 2166 * It may run a bit until it hits a thread_suspend_check(). 2167 */ 2168 mtx_lock_spin(&sched_lock); 2169 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2170 sleepq_abort(td); 2171 mtx_unlock_spin(&sched_lock); 2172 goto out; 2173 /* 2174 * Mutexes are short lived. Threads waiting on them will 2175 * hit thread_suspend_check() soon. 2176 */ 2177 } else if (p->p_state == PRS_NORMAL) { 2178 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2179 mtx_lock_spin(&sched_lock); 2180 tdsigwakeup(td, sig, action); 2181 mtx_unlock_spin(&sched_lock); 2182 goto out; 2183 } 2184 2185 MPASS(action == SIG_DFL); 2186 2187 if (prop & SA_STOP) { 2188 if (p->p_flag & P_PPWAIT) 2189 goto out; 2190 p->p_flag |= P_STOPPED_SIG; 2191 p->p_xstat = sig; 2192 p->p_xthread = td; 2193 mtx_lock_spin(&sched_lock); 2194 FOREACH_THREAD_IN_PROC(p, td0) { 2195 if (TD_IS_SLEEPING(td0) && 2196 (td0->td_flags & TDF_SINTR) && 2197 !TD_IS_SUSPENDED(td0)) { 2198 thread_suspend_one(td0); 2199 } else if (td != td0) { 2200 td0->td_flags |= TDF_ASTPENDING; 2201 } 2202 } 2203 thread_stopped(p); 2204 if (p->p_numthreads == p->p_suspcount) { 2205 mtx_unlock_spin(&sched_lock); 2206 sigqueue_delete_proc(p, p->p_xstat); 2207 } else 2208 mtx_unlock_spin(&sched_lock); 2209 goto out; 2210 } 2211 else 2212 goto runfast; 2213 /* NOTREACHED */ 2214 } else { 2215 /* Not in "NORMAL" state. discard the signal. */ 2216 sigqueue_delete(sigqueue, sig); 2217 goto out; 2218 } 2219 2220 /* 2221 * The process is not stopped so we need to apply the signal to all the 2222 * running threads. 2223 */ 2224 2225 runfast: 2226 mtx_lock_spin(&sched_lock); 2227 tdsigwakeup(td, sig, action); 2228 thread_unsuspend(p); 2229 mtx_unlock_spin(&sched_lock); 2230 out: 2231 /* If we jump here, sched_lock should not be owned. */ 2232 mtx_assert(&sched_lock, MA_NOTOWNED); 2233 return (ret); 2234 } 2235 2236 /* 2237 * The force of a signal has been directed against a single 2238 * thread. We need to see what we can do about knocking it 2239 * out of any sleep it may be in etc. 2240 */ 2241 static void 2242 tdsigwakeup(struct thread *td, int sig, sig_t action) 2243 { 2244 struct proc *p = td->td_proc; 2245 register int prop; 2246 2247 PROC_LOCK_ASSERT(p, MA_OWNED); 2248 mtx_assert(&sched_lock, MA_OWNED); 2249 prop = sigprop(sig); 2250 2251 /* 2252 * Bring the priority of a thread up if we want it to get 2253 * killed in this lifetime. 2254 */ 2255 if (action == SIG_DFL && (prop & SA_KILL)) { 2256 if (p->p_nice > 0) 2257 sched_nice(td->td_proc, 0); 2258 if (td->td_priority > PUSER) 2259 sched_prio(td, PUSER); 2260 } 2261 2262 if (TD_ON_SLEEPQ(td)) { 2263 /* 2264 * If thread is sleeping uninterruptibly 2265 * we can't interrupt the sleep... the signal will 2266 * be noticed when the process returns through 2267 * trap() or syscall(). 2268 */ 2269 if ((td->td_flags & TDF_SINTR) == 0) 2270 return; 2271 /* 2272 * If SIGCONT is default (or ignored) and process is 2273 * asleep, we are finished; the process should not 2274 * be awakened. 2275 */ 2276 if ((prop & SA_CONT) && action == SIG_DFL) { 2277 mtx_unlock_spin(&sched_lock); 2278 sigqueue_delete(&p->p_sigqueue, sig); 2279 /* 2280 * It may be on either list in this state. 2281 * Remove from both for now. 2282 */ 2283 sigqueue_delete(&td->td_sigqueue, sig); 2284 mtx_lock_spin(&sched_lock); 2285 return; 2286 } 2287 2288 /* 2289 * Give low priority threads a better chance to run. 2290 */ 2291 if (td->td_priority > PUSER) 2292 sched_prio(td, PUSER); 2293 2294 sleepq_abort(td); 2295 } else { 2296 /* 2297 * Other states do nothing with the signal immediately, 2298 * other than kicking ourselves if we are running. 2299 * It will either never be noticed, or noticed very soon. 2300 */ 2301 #ifdef SMP 2302 if (TD_IS_RUNNING(td) && td != curthread) 2303 forward_signal(td); 2304 #endif 2305 } 2306 } 2307 2308 int 2309 ptracestop(struct thread *td, int sig) 2310 { 2311 struct proc *p = td->td_proc; 2312 struct thread *td0; 2313 2314 PROC_LOCK_ASSERT(p, MA_OWNED); 2315 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2316 &p->p_mtx.mtx_object, "Stopping for traced signal"); 2317 2318 mtx_lock_spin(&sched_lock); 2319 td->td_flags |= TDF_XSIG; 2320 mtx_unlock_spin(&sched_lock); 2321 td->td_xsig = sig; 2322 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2323 if (p->p_flag & P_SINGLE_EXIT) { 2324 mtx_lock_spin(&sched_lock); 2325 td->td_flags &= ~TDF_XSIG; 2326 mtx_unlock_spin(&sched_lock); 2327 return (sig); 2328 } 2329 /* 2330 * Just make wait() to work, the last stopped thread 2331 * will win. 2332 */ 2333 p->p_xstat = sig; 2334 p->p_xthread = td; 2335 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2336 mtx_lock_spin(&sched_lock); 2337 FOREACH_THREAD_IN_PROC(p, td0) { 2338 if (TD_IS_SLEEPING(td0) && 2339 (td0->td_flags & TDF_SINTR) && 2340 !TD_IS_SUSPENDED(td0)) { 2341 thread_suspend_one(td0); 2342 } else if (td != td0) { 2343 td0->td_flags |= TDF_ASTPENDING; 2344 } 2345 } 2346 stopme: 2347 thread_stopped(p); 2348 thread_suspend_one(td); 2349 PROC_UNLOCK(p); 2350 DROP_GIANT(); 2351 mi_switch(SW_VOL, NULL); 2352 mtx_unlock_spin(&sched_lock); 2353 PICKUP_GIANT(); 2354 PROC_LOCK(p); 2355 if (!(p->p_flag & P_TRACED)) 2356 break; 2357 if (td->td_flags & TDF_DBSUSPEND) { 2358 if (p->p_flag & P_SINGLE_EXIT) 2359 break; 2360 mtx_lock_spin(&sched_lock); 2361 goto stopme; 2362 } 2363 } 2364 return (td->td_xsig); 2365 } 2366 2367 /* 2368 * If the current process has received a signal (should be caught or cause 2369 * termination, should interrupt current syscall), return the signal number. 2370 * Stop signals with default action are processed immediately, then cleared; 2371 * they aren't returned. This is checked after each entry to the system for 2372 * a syscall or trap (though this can usually be done without calling issignal 2373 * by checking the pending signal masks in cursig.) The normal call 2374 * sequence is 2375 * 2376 * while (sig = cursig(curthread)) 2377 * postsig(sig); 2378 */ 2379 static int 2380 issignal(td) 2381 struct thread *td; 2382 { 2383 struct proc *p; 2384 struct sigacts *ps; 2385 sigset_t sigpending; 2386 int sig, prop, newsig; 2387 struct thread *td0; 2388 2389 p = td->td_proc; 2390 ps = p->p_sigacts; 2391 mtx_assert(&ps->ps_mtx, MA_OWNED); 2392 PROC_LOCK_ASSERT(p, MA_OWNED); 2393 for (;;) { 2394 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2395 2396 sigpending = td->td_sigqueue.sq_signals; 2397 SIGSETNAND(sigpending, td->td_sigmask); 2398 2399 if (p->p_flag & P_PPWAIT) 2400 SIG_STOPSIGMASK(sigpending); 2401 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2402 return (0); 2403 sig = sig_ffs(&sigpending); 2404 2405 if (p->p_stops & S_SIG) { 2406 mtx_unlock(&ps->ps_mtx); 2407 stopevent(p, S_SIG, sig); 2408 mtx_lock(&ps->ps_mtx); 2409 } 2410 2411 /* 2412 * We should see pending but ignored signals 2413 * only if P_TRACED was on when they were posted. 2414 */ 2415 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2416 sigqueue_delete(&td->td_sigqueue, sig); 2417 if (td->td_pflags & TDP_SA) 2418 SIGADDSET(td->td_sigmask, sig); 2419 continue; 2420 } 2421 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2422 /* 2423 * If traced, always stop. 2424 */ 2425 mtx_unlock(&ps->ps_mtx); 2426 newsig = ptracestop(td, sig); 2427 mtx_lock(&ps->ps_mtx); 2428 2429 if (td->td_pflags & TDP_SA) 2430 SIGADDSET(td->td_sigmask, sig); 2431 2432 if (sig != newsig) { 2433 /* 2434 * clear old signal. 2435 * XXX shrug off debugger, it causes siginfo to 2436 * be thrown away. 2437 */ 2438 sigqueue_delete(&td->td_sigqueue, sig); 2439 2440 /* 2441 * If parent wants us to take the signal, 2442 * then it will leave it in p->p_xstat; 2443 * otherwise we just look for signals again. 2444 */ 2445 if (newsig == 0) 2446 continue; 2447 sig = newsig; 2448 2449 /* 2450 * Put the new signal into td_sigqueue. If the 2451 * signal is being masked, look for other signals. 2452 */ 2453 SIGADDSET(td->td_sigqueue.sq_signals, sig); 2454 if (td->td_pflags & TDP_SA) 2455 SIGDELSET(td->td_sigmask, sig); 2456 if (SIGISMEMBER(td->td_sigmask, sig)) 2457 continue; 2458 signotify(td); 2459 } 2460 2461 /* 2462 * If the traced bit got turned off, go back up 2463 * to the top to rescan signals. This ensures 2464 * that p_sig* and p_sigact are consistent. 2465 */ 2466 if ((p->p_flag & P_TRACED) == 0) 2467 continue; 2468 } 2469 2470 prop = sigprop(sig); 2471 2472 /* 2473 * Decide whether the signal should be returned. 2474 * Return the signal's number, or fall through 2475 * to clear it from the pending mask. 2476 */ 2477 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2478 2479 case (intptr_t)SIG_DFL: 2480 /* 2481 * Don't take default actions on system processes. 2482 */ 2483 if (p->p_pid <= 1) { 2484 #ifdef DIAGNOSTIC 2485 /* 2486 * Are you sure you want to ignore SIGSEGV 2487 * in init? XXX 2488 */ 2489 printf("Process (pid %lu) got signal %d\n", 2490 (u_long)p->p_pid, sig); 2491 #endif 2492 break; /* == ignore */ 2493 } 2494 /* 2495 * If there is a pending stop signal to process 2496 * with default action, stop here, 2497 * then clear the signal. However, 2498 * if process is member of an orphaned 2499 * process group, ignore tty stop signals. 2500 */ 2501 if (prop & SA_STOP) { 2502 if (p->p_flag & P_TRACED || 2503 (p->p_pgrp->pg_jobc == 0 && 2504 prop & SA_TTYSTOP)) 2505 break; /* == ignore */ 2506 mtx_unlock(&ps->ps_mtx); 2507 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2508 &p->p_mtx.mtx_object, "Catching SIGSTOP"); 2509 p->p_flag |= P_STOPPED_SIG; 2510 p->p_xstat = sig; 2511 p->p_xthread = td; 2512 mtx_lock_spin(&sched_lock); 2513 FOREACH_THREAD_IN_PROC(p, td0) { 2514 if (TD_IS_SLEEPING(td0) && 2515 (td0->td_flags & TDF_SINTR) && 2516 !TD_IS_SUSPENDED(td0)) { 2517 thread_suspend_one(td0); 2518 } else if (td != td0) { 2519 td0->td_flags |= TDF_ASTPENDING; 2520 } 2521 } 2522 thread_stopped(p); 2523 thread_suspend_one(td); 2524 PROC_UNLOCK(p); 2525 DROP_GIANT(); 2526 mi_switch(SW_INVOL, NULL); 2527 mtx_unlock_spin(&sched_lock); 2528 PICKUP_GIANT(); 2529 PROC_LOCK(p); 2530 mtx_lock(&ps->ps_mtx); 2531 break; 2532 } else if (prop & SA_IGNORE) { 2533 /* 2534 * Except for SIGCONT, shouldn't get here. 2535 * Default action is to ignore; drop it. 2536 */ 2537 break; /* == ignore */ 2538 } else 2539 return (sig); 2540 /*NOTREACHED*/ 2541 2542 case (intptr_t)SIG_IGN: 2543 /* 2544 * Masking above should prevent us ever trying 2545 * to take action on an ignored signal other 2546 * than SIGCONT, unless process is traced. 2547 */ 2548 if ((prop & SA_CONT) == 0 && 2549 (p->p_flag & P_TRACED) == 0) 2550 printf("issignal\n"); 2551 break; /* == ignore */ 2552 2553 default: 2554 /* 2555 * This signal has an action, let 2556 * postsig() process it. 2557 */ 2558 return (sig); 2559 } 2560 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2561 } 2562 /* NOTREACHED */ 2563 } 2564 2565 /* 2566 * MPSAFE 2567 */ 2568 void 2569 thread_stopped(struct proc *p) 2570 { 2571 struct proc *p1 = curthread->td_proc; 2572 struct sigacts *ps; 2573 int n; 2574 2575 PROC_LOCK_ASSERT(p, MA_OWNED); 2576 mtx_assert(&sched_lock, MA_OWNED); 2577 n = p->p_suspcount; 2578 if (p == p1) 2579 n++; 2580 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2581 mtx_unlock_spin(&sched_lock); 2582 p->p_flag &= ~P_WAITED; 2583 PROC_LOCK(p->p_pptr); 2584 /* 2585 * Wake up parent sleeping in kern_wait(), also send 2586 * SIGCHLD to parent, but SIGCHLD does not guarantee 2587 * that parent will awake, because parent may masked 2588 * the signal. 2589 */ 2590 p->p_pptr->p_flag |= P_STATCHILD; 2591 wakeup(p->p_pptr); 2592 ps = p->p_pptr->p_sigacts; 2593 mtx_lock(&ps->ps_mtx); 2594 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2595 mtx_unlock(&ps->ps_mtx); 2596 psignal(p->p_pptr, SIGCHLD); 2597 } else 2598 mtx_unlock(&ps->ps_mtx); 2599 PROC_UNLOCK(p->p_pptr); 2600 mtx_lock_spin(&sched_lock); 2601 } 2602 } 2603 2604 /* 2605 * Take the action for the specified signal 2606 * from the current set of pending signals. 2607 */ 2608 void 2609 postsig(sig) 2610 register int sig; 2611 { 2612 struct thread *td = curthread; 2613 register struct proc *p = td->td_proc; 2614 struct sigacts *ps; 2615 sig_t action; 2616 ksiginfo_t ksi; 2617 sigset_t returnmask; 2618 int code; 2619 2620 KASSERT(sig != 0, ("postsig")); 2621 2622 PROC_LOCK_ASSERT(p, MA_OWNED); 2623 ps = p->p_sigacts; 2624 mtx_assert(&ps->ps_mtx, MA_OWNED); 2625 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2626 ksi.ksi_signo = sig; 2627 2628 action = ps->ps_sigact[_SIG_IDX(sig)]; 2629 #ifdef KTRACE 2630 if (KTRPOINT(td, KTR_PSIG)) 2631 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2632 &td->td_oldsigmask : &td->td_sigmask, 0); 2633 #endif 2634 if (p->p_stops & S_SIG) { 2635 mtx_unlock(&ps->ps_mtx); 2636 stopevent(p, S_SIG, sig); 2637 mtx_lock(&ps->ps_mtx); 2638 } 2639 2640 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2641 /* 2642 * Default action, where the default is to kill 2643 * the process. (Other cases were ignored above.) 2644 */ 2645 mtx_unlock(&ps->ps_mtx); 2646 sigexit(td, sig); 2647 /* NOTREACHED */ 2648 } else { 2649 if (td->td_pflags & TDP_SA) { 2650 if (sig == SIGKILL) { 2651 mtx_unlock(&ps->ps_mtx); 2652 sigexit(td, sig); 2653 } 2654 } 2655 2656 /* 2657 * If we get here, the signal must be caught. 2658 */ 2659 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2660 ("postsig action")); 2661 /* 2662 * Set the new mask value and also defer further 2663 * occurrences of this signal. 2664 * 2665 * Special case: user has done a sigsuspend. Here the 2666 * current mask is not of interest, but rather the 2667 * mask from before the sigsuspend is what we want 2668 * restored after the signal processing is completed. 2669 */ 2670 if (td->td_pflags & TDP_OLDMASK) { 2671 returnmask = td->td_oldsigmask; 2672 td->td_pflags &= ~TDP_OLDMASK; 2673 } else 2674 returnmask = td->td_sigmask; 2675 2676 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2677 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2678 SIGADDSET(td->td_sigmask, sig); 2679 2680 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2681 /* 2682 * See kern_sigaction() for origin of this code. 2683 */ 2684 SIGDELSET(ps->ps_sigcatch, sig); 2685 if (sig != SIGCONT && 2686 sigprop(sig) & SA_IGNORE) 2687 SIGADDSET(ps->ps_sigignore, sig); 2688 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2689 } 2690 p->p_stats->p_ru.ru_nsignals++; 2691 if (p->p_sig != sig) { 2692 code = 0; 2693 } else { 2694 code = p->p_code; 2695 p->p_code = 0; 2696 p->p_sig = 0; 2697 } 2698 if (td->td_pflags & TDP_SA) 2699 thread_signal_add(curthread, &ksi); 2700 else 2701 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2702 } 2703 } 2704 2705 /* 2706 * Kill the current process for stated reason. 2707 */ 2708 void 2709 killproc(p, why) 2710 struct proc *p; 2711 char *why; 2712 { 2713 2714 PROC_LOCK_ASSERT(p, MA_OWNED); 2715 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2716 p, p->p_pid, p->p_comm); 2717 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2718 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2719 psignal(p, SIGKILL); 2720 } 2721 2722 /* 2723 * Force the current process to exit with the specified signal, dumping core 2724 * if appropriate. We bypass the normal tests for masked and caught signals, 2725 * allowing unrecoverable failures to terminate the process without changing 2726 * signal state. Mark the accounting record with the signal termination. 2727 * If dumping core, save the signal number for the debugger. Calls exit and 2728 * does not return. 2729 * 2730 * MPSAFE 2731 */ 2732 void 2733 sigexit(td, sig) 2734 struct thread *td; 2735 int sig; 2736 { 2737 struct proc *p = td->td_proc; 2738 2739 PROC_LOCK_ASSERT(p, MA_OWNED); 2740 p->p_acflag |= AXSIG; 2741 /* 2742 * We must be single-threading to generate a core dump. This 2743 * ensures that the registers in the core file are up-to-date. 2744 * Also, the ELF dump handler assumes that the thread list doesn't 2745 * change out from under it. 2746 * 2747 * XXX If another thread attempts to single-thread before us 2748 * (e.g. via fork()), we won't get a dump at all. 2749 */ 2750 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2751 p->p_sig = sig; 2752 /* 2753 * Log signals which would cause core dumps 2754 * (Log as LOG_INFO to appease those who don't want 2755 * these messages.) 2756 * XXX : Todo, as well as euid, write out ruid too 2757 * Note that coredump() drops proc lock. 2758 */ 2759 if (coredump(td) == 0) 2760 sig |= WCOREFLAG; 2761 if (kern_logsigexit) 2762 log(LOG_INFO, 2763 "pid %d (%s), uid %d: exited on signal %d%s\n", 2764 p->p_pid, p->p_comm, 2765 td->td_ucred ? td->td_ucred->cr_uid : -1, 2766 sig &~ WCOREFLAG, 2767 sig & WCOREFLAG ? " (core dumped)" : ""); 2768 } else 2769 PROC_UNLOCK(p); 2770 exit1(td, W_EXITCODE(0, sig)); 2771 /* NOTREACHED */ 2772 } 2773 2774 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2775 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2776 sizeof(corefilename), "process corefile name format string"); 2777 2778 /* 2779 * expand_name(name, uid, pid) 2780 * Expand the name described in corefilename, using name, uid, and pid. 2781 * corefilename is a printf-like string, with three format specifiers: 2782 * %N name of process ("name") 2783 * %P process id (pid) 2784 * %U user id (uid) 2785 * For example, "%N.core" is the default; they can be disabled completely 2786 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2787 * This is controlled by the sysctl variable kern.corefile (see above). 2788 */ 2789 2790 static char * 2791 expand_name(name, uid, pid) 2792 const char *name; 2793 uid_t uid; 2794 pid_t pid; 2795 { 2796 const char *format, *appendstr; 2797 char *temp; 2798 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2799 size_t i, l, n; 2800 2801 format = corefilename; 2802 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2803 if (temp == NULL) 2804 return (NULL); 2805 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2806 switch (format[i]) { 2807 case '%': /* Format character */ 2808 i++; 2809 switch (format[i]) { 2810 case '%': 2811 appendstr = "%"; 2812 break; 2813 case 'N': /* process name */ 2814 appendstr = name; 2815 break; 2816 case 'P': /* process id */ 2817 sprintf(buf, "%u", pid); 2818 appendstr = buf; 2819 break; 2820 case 'U': /* user id */ 2821 sprintf(buf, "%u", uid); 2822 appendstr = buf; 2823 break; 2824 default: 2825 appendstr = ""; 2826 log(LOG_ERR, 2827 "Unknown format character %c in `%s'\n", 2828 format[i], format); 2829 } 2830 l = strlen(appendstr); 2831 if ((n + l) >= MAXPATHLEN) 2832 goto toolong; 2833 memcpy(temp + n, appendstr, l); 2834 n += l; 2835 break; 2836 default: 2837 temp[n++] = format[i]; 2838 } 2839 } 2840 if (format[i] != '\0') 2841 goto toolong; 2842 return (temp); 2843 toolong: 2844 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 2845 (long)pid, name, (u_long)uid); 2846 free(temp, M_TEMP); 2847 return (NULL); 2848 } 2849 2850 /* 2851 * Dump a process' core. The main routine does some 2852 * policy checking, and creates the name of the coredump; 2853 * then it passes on a vnode and a size limit to the process-specific 2854 * coredump routine if there is one; if there _is not_ one, it returns 2855 * ENOSYS; otherwise it returns the error from the process-specific routine. 2856 */ 2857 2858 static int 2859 coredump(struct thread *td) 2860 { 2861 struct proc *p = td->td_proc; 2862 register struct vnode *vp; 2863 register struct ucred *cred = td->td_ucred; 2864 struct flock lf; 2865 struct nameidata nd; 2866 struct vattr vattr; 2867 int error, error1, flags, locked; 2868 struct mount *mp; 2869 char *name; /* name of corefile */ 2870 off_t limit; 2871 2872 PROC_LOCK_ASSERT(p, MA_OWNED); 2873 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 2874 _STOPEVENT(p, S_CORE, 0); 2875 2876 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 2877 PROC_UNLOCK(p); 2878 return (EFAULT); 2879 } 2880 2881 /* 2882 * Note that the bulk of limit checking is done after 2883 * the corefile is created. The exception is if the limit 2884 * for corefiles is 0, in which case we don't bother 2885 * creating the corefile at all. This layout means that 2886 * a corefile is truncated instead of not being created, 2887 * if it is larger than the limit. 2888 */ 2889 limit = (off_t)lim_cur(p, RLIMIT_CORE); 2890 PROC_UNLOCK(p); 2891 if (limit == 0) 2892 return (EFBIG); 2893 2894 mtx_lock(&Giant); 2895 restart: 2896 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 2897 if (name == NULL) { 2898 mtx_unlock(&Giant); 2899 return (EINVAL); 2900 } 2901 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); /* XXXKSE */ 2902 flags = O_CREAT | FWRITE | O_NOFOLLOW; 2903 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, -1); 2904 free(name, M_TEMP); 2905 if (error) { 2906 mtx_unlock(&Giant); 2907 return (error); 2908 } 2909 NDFREE(&nd, NDF_ONLY_PNBUF); 2910 vp = nd.ni_vp; 2911 2912 /* Don't dump to non-regular files or files with links. */ 2913 if (vp->v_type != VREG || 2914 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 2915 VOP_UNLOCK(vp, 0, td); 2916 error = EFAULT; 2917 goto out; 2918 } 2919 2920 VOP_UNLOCK(vp, 0, td); 2921 lf.l_whence = SEEK_SET; 2922 lf.l_start = 0; 2923 lf.l_len = 0; 2924 lf.l_type = F_WRLCK; 2925 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 2926 2927 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 2928 lf.l_type = F_UNLCK; 2929 if (locked) 2930 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2931 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 2932 return (error); 2933 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 2934 return (error); 2935 goto restart; 2936 } 2937 2938 VATTR_NULL(&vattr); 2939 vattr.va_size = 0; 2940 if (set_core_nodump_flag) 2941 vattr.va_flags = UF_NODUMP; 2942 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 2943 VOP_LEASE(vp, td, cred, LEASE_WRITE); 2944 VOP_SETATTR(vp, &vattr, cred, td); 2945 VOP_UNLOCK(vp, 0, td); 2946 PROC_LOCK(p); 2947 p->p_acflag |= ACORE; 2948 PROC_UNLOCK(p); 2949 2950 error = p->p_sysent->sv_coredump ? 2951 p->p_sysent->sv_coredump(td, vp, limit) : 2952 ENOSYS; 2953 2954 if (locked) { 2955 lf.l_type = F_UNLCK; 2956 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 2957 } 2958 vn_finished_write(mp); 2959 out: 2960 error1 = vn_close(vp, FWRITE, cred, td); 2961 mtx_unlock(&Giant); 2962 if (error == 0) 2963 error = error1; 2964 return (error); 2965 } 2966 2967 /* 2968 * Nonexistent system call-- signal process (may want to handle it). 2969 * Flag error in case process won't see signal immediately (blocked or ignored). 2970 */ 2971 #ifndef _SYS_SYSPROTO_H_ 2972 struct nosys_args { 2973 int dummy; 2974 }; 2975 #endif 2976 /* 2977 * MPSAFE 2978 */ 2979 /* ARGSUSED */ 2980 int 2981 nosys(td, args) 2982 struct thread *td; 2983 struct nosys_args *args; 2984 { 2985 struct proc *p = td->td_proc; 2986 2987 PROC_LOCK(p); 2988 psignal(p, SIGSYS); 2989 PROC_UNLOCK(p); 2990 return (ENOSYS); 2991 } 2992 2993 /* 2994 * Send a SIGIO or SIGURG signal to a process or process group using 2995 * stored credentials rather than those of the current process. 2996 */ 2997 void 2998 pgsigio(sigiop, sig, checkctty) 2999 struct sigio **sigiop; 3000 int sig, checkctty; 3001 { 3002 struct sigio *sigio; 3003 3004 SIGIO_LOCK(); 3005 sigio = *sigiop; 3006 if (sigio == NULL) { 3007 SIGIO_UNLOCK(); 3008 return; 3009 } 3010 if (sigio->sio_pgid > 0) { 3011 PROC_LOCK(sigio->sio_proc); 3012 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3013 psignal(sigio->sio_proc, sig); 3014 PROC_UNLOCK(sigio->sio_proc); 3015 } else if (sigio->sio_pgid < 0) { 3016 struct proc *p; 3017 3018 PGRP_LOCK(sigio->sio_pgrp); 3019 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3020 PROC_LOCK(p); 3021 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3022 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3023 psignal(p, sig); 3024 PROC_UNLOCK(p); 3025 } 3026 PGRP_UNLOCK(sigio->sio_pgrp); 3027 } 3028 SIGIO_UNLOCK(); 3029 } 3030 3031 static int 3032 filt_sigattach(struct knote *kn) 3033 { 3034 struct proc *p = curproc; 3035 3036 kn->kn_ptr.p_proc = p; 3037 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3038 3039 knlist_add(&p->p_klist, kn, 0); 3040 3041 return (0); 3042 } 3043 3044 static void 3045 filt_sigdetach(struct knote *kn) 3046 { 3047 struct proc *p = kn->kn_ptr.p_proc; 3048 3049 knlist_remove(&p->p_klist, kn, 0); 3050 } 3051 3052 /* 3053 * signal knotes are shared with proc knotes, so we apply a mask to 3054 * the hint in order to differentiate them from process hints. This 3055 * could be avoided by using a signal-specific knote list, but probably 3056 * isn't worth the trouble. 3057 */ 3058 static int 3059 filt_signal(struct knote *kn, long hint) 3060 { 3061 3062 if (hint & NOTE_SIGNAL) { 3063 hint &= ~NOTE_SIGNAL; 3064 3065 if (kn->kn_id == hint) 3066 kn->kn_data++; 3067 } 3068 return (kn->kn_data != 0); 3069 } 3070 3071 struct sigacts * 3072 sigacts_alloc(void) 3073 { 3074 struct sigacts *ps; 3075 3076 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3077 ps->ps_refcnt = 1; 3078 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3079 return (ps); 3080 } 3081 3082 void 3083 sigacts_free(struct sigacts *ps) 3084 { 3085 3086 mtx_lock(&ps->ps_mtx); 3087 ps->ps_refcnt--; 3088 if (ps->ps_refcnt == 0) { 3089 mtx_destroy(&ps->ps_mtx); 3090 free(ps, M_SUBPROC); 3091 } else 3092 mtx_unlock(&ps->ps_mtx); 3093 } 3094 3095 struct sigacts * 3096 sigacts_hold(struct sigacts *ps) 3097 { 3098 mtx_lock(&ps->ps_mtx); 3099 ps->ps_refcnt++; 3100 mtx_unlock(&ps->ps_mtx); 3101 return (ps); 3102 } 3103 3104 void 3105 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3106 { 3107 3108 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3109 mtx_lock(&src->ps_mtx); 3110 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3111 mtx_unlock(&src->ps_mtx); 3112 } 3113 3114 int 3115 sigacts_shared(struct sigacts *ps) 3116 { 3117 int shared; 3118 3119 mtx_lock(&ps->ps_mtx); 3120 shared = ps->ps_refcnt > 1; 3121 mtx_unlock(&ps->ps_mtx); 3122 return (shared); 3123 } 3124