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/posix4.h> 61 #include <sys/pioctl.h> 62 #include <sys/resourcevar.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 <machine/cpu.h> 80 81 #include <security/audit/audit.h> 82 83 #define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 84 85 static int coredump(struct thread *); 86 static char *expand_name(const char *, uid_t, pid_t); 87 static int killpg1(struct thread *td, int sig, int pgid, int all); 88 static int issignal(struct thread *p); 89 static int sigprop(int sig); 90 static void tdsigwakeup(struct thread *, int, sig_t, int); 91 static void sig_suspend_threads(struct thread *, struct proc *, int); 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 #ifdef KSE 97 static int do_tdsignal(struct proc *, struct thread *, int, ksiginfo_t *); 98 #endif 99 static void sigqueue_start(void); 100 101 static uma_zone_t ksiginfo_zone = NULL; 102 struct filterops sig_filtops = 103 { 0, filt_sigattach, filt_sigdetach, filt_signal }; 104 105 static int kern_logsigexit = 1; 106 SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 107 &kern_logsigexit, 0, 108 "Log processes quitting on abnormal signals to syslog(3)"); 109 110 static int kern_forcesigexit = 1; 111 SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 112 &kern_forcesigexit, 0, "Force trap signal to be handled"); 113 114 SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, "POSIX real time signal"); 115 116 static int max_pending_per_proc = 128; 117 SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 118 &max_pending_per_proc, 0, "Max pending signals per proc"); 119 120 static int preallocate_siginfo = 1024; 121 TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 122 SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 123 &preallocate_siginfo, 0, "Preallocated signal memory size"); 124 125 static int signal_overflow = 0; 126 SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 127 &signal_overflow, 0, "Number of signals overflew"); 128 129 static int signal_alloc_fail = 0; 130 SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 131 &signal_alloc_fail, 0, "signals failed to be allocated"); 132 133 SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 134 135 /* 136 * Policy -- Can ucred cr1 send SIGIO to process cr2? 137 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 138 * in the right situations. 139 */ 140 #define CANSIGIO(cr1, cr2) \ 141 ((cr1)->cr_uid == 0 || \ 142 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 143 (cr1)->cr_uid == (cr2)->cr_ruid || \ 144 (cr1)->cr_ruid == (cr2)->cr_uid || \ 145 (cr1)->cr_uid == (cr2)->cr_uid) 146 147 int sugid_coredump; 148 SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 149 &sugid_coredump, 0, "Enable coredumping set user/group ID processes"); 150 151 static int do_coredump = 1; 152 SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 153 &do_coredump, 0, "Enable/Disable coredumps"); 154 155 static int set_core_nodump_flag = 0; 156 SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 157 0, "Enable setting the NODUMP flag on coredump files"); 158 159 /* 160 * Signal properties and actions. 161 * The array below categorizes the signals and their default actions 162 * according to the following properties: 163 */ 164 #define SA_KILL 0x01 /* terminates process by default */ 165 #define SA_CORE 0x02 /* ditto and coredumps */ 166 #define SA_STOP 0x04 /* suspend process */ 167 #define SA_TTYSTOP 0x08 /* ditto, from tty */ 168 #define SA_IGNORE 0x10 /* ignore by default */ 169 #define SA_CONT 0x20 /* continue if suspended */ 170 #define SA_CANTMASK 0x40 /* non-maskable, catchable */ 171 #define SA_PROC 0x80 /* deliverable to any thread */ 172 173 static int sigproptbl[NSIG] = { 174 SA_KILL|SA_PROC, /* SIGHUP */ 175 SA_KILL|SA_PROC, /* SIGINT */ 176 SA_KILL|SA_CORE|SA_PROC, /* SIGQUIT */ 177 SA_KILL|SA_CORE, /* SIGILL */ 178 SA_KILL|SA_CORE, /* SIGTRAP */ 179 SA_KILL|SA_CORE, /* SIGABRT */ 180 SA_KILL|SA_CORE|SA_PROC, /* SIGEMT */ 181 SA_KILL|SA_CORE, /* SIGFPE */ 182 SA_KILL|SA_PROC, /* SIGKILL */ 183 SA_KILL|SA_CORE, /* SIGBUS */ 184 SA_KILL|SA_CORE, /* SIGSEGV */ 185 SA_KILL|SA_CORE, /* SIGSYS */ 186 SA_KILL|SA_PROC, /* SIGPIPE */ 187 SA_KILL|SA_PROC, /* SIGALRM */ 188 SA_KILL|SA_PROC, /* SIGTERM */ 189 SA_IGNORE|SA_PROC, /* SIGURG */ 190 SA_STOP|SA_PROC, /* SIGSTOP */ 191 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTSTP */ 192 SA_IGNORE|SA_CONT|SA_PROC, /* SIGCONT */ 193 SA_IGNORE|SA_PROC, /* SIGCHLD */ 194 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTIN */ 195 SA_STOP|SA_TTYSTOP|SA_PROC, /* SIGTTOU */ 196 SA_IGNORE|SA_PROC, /* SIGIO */ 197 SA_KILL, /* SIGXCPU */ 198 SA_KILL, /* SIGXFSZ */ 199 SA_KILL|SA_PROC, /* SIGVTALRM */ 200 SA_KILL|SA_PROC, /* SIGPROF */ 201 SA_IGNORE|SA_PROC, /* SIGWINCH */ 202 SA_IGNORE|SA_PROC, /* SIGINFO */ 203 SA_KILL|SA_PROC, /* SIGUSR1 */ 204 SA_KILL|SA_PROC, /* SIGUSR2 */ 205 }; 206 207 static void 208 sigqueue_start(void) 209 { 210 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 211 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 212 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 213 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 214 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 215 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 216 } 217 218 ksiginfo_t * 219 ksiginfo_alloc(int wait) 220 { 221 int flags; 222 223 flags = M_ZERO; 224 if (! wait) 225 flags |= M_NOWAIT; 226 if (ksiginfo_zone != NULL) 227 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 228 return (NULL); 229 } 230 231 void 232 ksiginfo_free(ksiginfo_t *ksi) 233 { 234 uma_zfree(ksiginfo_zone, ksi); 235 } 236 237 static __inline int 238 ksiginfo_tryfree(ksiginfo_t *ksi) 239 { 240 if (!(ksi->ksi_flags & KSI_EXT)) { 241 uma_zfree(ksiginfo_zone, ksi); 242 return (1); 243 } 244 return (0); 245 } 246 247 void 248 sigqueue_init(sigqueue_t *list, struct proc *p) 249 { 250 SIGEMPTYSET(list->sq_signals); 251 SIGEMPTYSET(list->sq_kill); 252 TAILQ_INIT(&list->sq_list); 253 list->sq_proc = p; 254 list->sq_flags = SQ_INIT; 255 } 256 257 /* 258 * Get a signal's ksiginfo. 259 * Return: 260 * 0 - signal not found 261 * others - signal number 262 */ 263 int 264 sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 265 { 266 struct proc *p = sq->sq_proc; 267 struct ksiginfo *ksi, *next; 268 int count = 0; 269 270 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 271 272 if (!SIGISMEMBER(sq->sq_signals, signo)) 273 return (0); 274 275 if (SIGISMEMBER(sq->sq_kill, signo)) { 276 count++; 277 SIGDELSET(sq->sq_kill, signo); 278 } 279 280 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 281 if (ksi->ksi_signo == signo) { 282 if (count == 0) { 283 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 284 ksi->ksi_sigq = NULL; 285 ksiginfo_copy(ksi, si); 286 if (ksiginfo_tryfree(ksi) && p != NULL) 287 p->p_pendingcnt--; 288 } 289 if (++count > 1) 290 break; 291 } 292 } 293 294 if (count <= 1) 295 SIGDELSET(sq->sq_signals, signo); 296 si->ksi_signo = signo; 297 return (signo); 298 } 299 300 void 301 sigqueue_take(ksiginfo_t *ksi) 302 { 303 struct ksiginfo *kp; 304 struct proc *p; 305 sigqueue_t *sq; 306 307 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 308 return; 309 310 p = sq->sq_proc; 311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 312 ksi->ksi_sigq = NULL; 313 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 314 p->p_pendingcnt--; 315 316 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 317 kp = TAILQ_NEXT(kp, ksi_link)) { 318 if (kp->ksi_signo == ksi->ksi_signo) 319 break; 320 } 321 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 322 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 323 } 324 325 int 326 sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 327 { 328 struct proc *p = sq->sq_proc; 329 struct ksiginfo *ksi; 330 int ret = 0; 331 332 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 333 334 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 335 SIGADDSET(sq->sq_kill, signo); 336 goto out_set_bit; 337 } 338 339 /* directly insert the ksi, don't copy it */ 340 if (si->ksi_flags & KSI_INS) { 341 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 342 si->ksi_sigq = sq; 343 goto out_set_bit; 344 } 345 346 if (__predict_false(ksiginfo_zone == NULL)) { 347 SIGADDSET(sq->sq_kill, signo); 348 goto out_set_bit; 349 } 350 351 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 352 signal_overflow++; 353 ret = EAGAIN; 354 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 355 signal_alloc_fail++; 356 ret = EAGAIN; 357 } else { 358 if (p != NULL) 359 p->p_pendingcnt++; 360 ksiginfo_copy(si, ksi); 361 ksi->ksi_signo = signo; 362 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 363 ksi->ksi_sigq = sq; 364 } 365 366 if ((si->ksi_flags & KSI_TRAP) != 0) { 367 if (ret != 0) 368 SIGADDSET(sq->sq_kill, signo); 369 ret = 0; 370 goto out_set_bit; 371 } 372 373 if (ret != 0) 374 return (ret); 375 376 out_set_bit: 377 SIGADDSET(sq->sq_signals, signo); 378 return (ret); 379 } 380 381 void 382 sigqueue_flush(sigqueue_t *sq) 383 { 384 struct proc *p = sq->sq_proc; 385 ksiginfo_t *ksi; 386 387 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 388 389 if (p != NULL) 390 PROC_LOCK_ASSERT(p, MA_OWNED); 391 392 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 393 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 394 ksi->ksi_sigq = NULL; 395 if (ksiginfo_tryfree(ksi) && p != NULL) 396 p->p_pendingcnt--; 397 } 398 399 SIGEMPTYSET(sq->sq_signals); 400 SIGEMPTYSET(sq->sq_kill); 401 } 402 403 void 404 sigqueue_collect_set(sigqueue_t *sq, sigset_t *set) 405 { 406 ksiginfo_t *ksi; 407 408 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 409 410 TAILQ_FOREACH(ksi, &sq->sq_list, ksi_link) 411 SIGADDSET(*set, ksi->ksi_signo); 412 SIGSETOR(*set, sq->sq_kill); 413 } 414 415 void 416 sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, sigset_t *setp) 417 { 418 sigset_t tmp, set; 419 struct proc *p1, *p2; 420 ksiginfo_t *ksi, *next; 421 422 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 423 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 424 /* 425 * make a copy, this allows setp to point to src or dst 426 * sq_signals without trouble. 427 */ 428 set = *setp; 429 p1 = src->sq_proc; 430 p2 = dst->sq_proc; 431 /* Move siginfo to target list */ 432 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 433 if (SIGISMEMBER(set, ksi->ksi_signo)) { 434 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 435 if (p1 != NULL) 436 p1->p_pendingcnt--; 437 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 438 ksi->ksi_sigq = dst; 439 if (p2 != NULL) 440 p2->p_pendingcnt++; 441 } 442 } 443 444 /* Move pending bits to target list */ 445 tmp = src->sq_kill; 446 SIGSETAND(tmp, set); 447 SIGSETOR(dst->sq_kill, tmp); 448 SIGSETNAND(src->sq_kill, tmp); 449 450 tmp = src->sq_signals; 451 SIGSETAND(tmp, set); 452 SIGSETOR(dst->sq_signals, tmp); 453 SIGSETNAND(src->sq_signals, tmp); 454 455 /* Finally, rescan src queue and set pending bits for it */ 456 sigqueue_collect_set(src, &src->sq_signals); 457 } 458 459 void 460 sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 461 { 462 sigset_t set; 463 464 SIGEMPTYSET(set); 465 SIGADDSET(set, signo); 466 sigqueue_move_set(src, dst, &set); 467 } 468 469 void 470 sigqueue_delete_set(sigqueue_t *sq, sigset_t *set) 471 { 472 struct proc *p = sq->sq_proc; 473 ksiginfo_t *ksi, *next; 474 475 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 476 477 /* Remove siginfo queue */ 478 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 479 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 480 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 481 ksi->ksi_sigq = NULL; 482 if (ksiginfo_tryfree(ksi) && p != NULL) 483 p->p_pendingcnt--; 484 } 485 } 486 SIGSETNAND(sq->sq_kill, *set); 487 SIGSETNAND(sq->sq_signals, *set); 488 /* Finally, rescan queue and set pending bits for it */ 489 sigqueue_collect_set(sq, &sq->sq_signals); 490 } 491 492 void 493 sigqueue_delete(sigqueue_t *sq, int signo) 494 { 495 sigset_t set; 496 497 SIGEMPTYSET(set); 498 SIGADDSET(set, signo); 499 sigqueue_delete_set(sq, &set); 500 } 501 502 /* Remove a set of signals for a process */ 503 void 504 sigqueue_delete_set_proc(struct proc *p, sigset_t *set) 505 { 506 sigqueue_t worklist; 507 struct thread *td0; 508 509 PROC_LOCK_ASSERT(p, MA_OWNED); 510 511 sigqueue_init(&worklist, NULL); 512 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 513 514 PROC_SLOCK(p); 515 FOREACH_THREAD_IN_PROC(p, td0) 516 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 517 PROC_SUNLOCK(p); 518 519 sigqueue_flush(&worklist); 520 } 521 522 void 523 sigqueue_delete_proc(struct proc *p, int signo) 524 { 525 sigset_t set; 526 527 SIGEMPTYSET(set); 528 SIGADDSET(set, signo); 529 sigqueue_delete_set_proc(p, &set); 530 } 531 532 void 533 sigqueue_delete_stopmask_proc(struct proc *p) 534 { 535 sigset_t set; 536 537 SIGEMPTYSET(set); 538 SIGADDSET(set, SIGSTOP); 539 SIGADDSET(set, SIGTSTP); 540 SIGADDSET(set, SIGTTIN); 541 SIGADDSET(set, SIGTTOU); 542 sigqueue_delete_set_proc(p, &set); 543 } 544 545 /* 546 * Determine signal that should be delivered to process p, the current 547 * process, 0 if none. If there is a pending stop signal with default 548 * action, the process stops in issignal(). 549 */ 550 int 551 cursig(struct thread *td) 552 { 553 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 554 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 555 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 556 return (SIGPENDING(td) ? issignal(td) : 0); 557 } 558 559 /* 560 * Arrange for ast() to handle unmasked pending signals on return to user 561 * mode. This must be called whenever a signal is added to td_sigqueue or 562 * unmasked in td_sigmask. 563 */ 564 void 565 signotify(struct thread *td) 566 { 567 struct proc *p; 568 #ifdef KSE 569 sigset_t set, saved; 570 #else 571 sigset_t set; 572 #endif 573 574 p = td->td_proc; 575 576 PROC_LOCK_ASSERT(p, MA_OWNED); 577 578 /* 579 * If our mask changed we may have to move signal that were 580 * previously masked by all threads to our sigqueue. 581 */ 582 set = p->p_sigqueue.sq_signals; 583 #ifdef KSE 584 if (p->p_flag & P_SA) 585 saved = p->p_sigqueue.sq_signals; 586 #endif 587 SIGSETNAND(set, td->td_sigmask); 588 if (! SIGISEMPTY(set)) 589 sigqueue_move_set(&p->p_sigqueue, &td->td_sigqueue, &set); 590 if (SIGPENDING(td)) { 591 thread_lock(td); 592 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 593 thread_unlock(td); 594 } 595 #ifdef KSE 596 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 597 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 598 /* pending set changed */ 599 p->p_flag |= P_SIGEVENT; 600 wakeup(&p->p_siglist); 601 } 602 } 603 #endif 604 } 605 606 int 607 sigonstack(size_t sp) 608 { 609 struct thread *td = curthread; 610 611 return ((td->td_pflags & TDP_ALTSTACK) ? 612 #if defined(COMPAT_43) 613 ((td->td_sigstk.ss_size == 0) ? 614 (td->td_sigstk.ss_flags & SS_ONSTACK) : 615 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 616 #else 617 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 618 #endif 619 : 0); 620 } 621 622 static __inline int 623 sigprop(int sig) 624 { 625 626 if (sig > 0 && sig < NSIG) 627 return (sigproptbl[_SIG_IDX(sig)]); 628 return (0); 629 } 630 631 int 632 sig_ffs(sigset_t *set) 633 { 634 int i; 635 636 for (i = 0; i < _SIG_WORDS; i++) 637 if (set->__bits[i]) 638 return (ffs(set->__bits[i]) + (i * 32)); 639 return (0); 640 } 641 642 /* 643 * kern_sigaction 644 * sigaction 645 * freebsd4_sigaction 646 * osigaction 647 */ 648 int 649 kern_sigaction(td, sig, act, oact, flags) 650 struct thread *td; 651 register int sig; 652 struct sigaction *act, *oact; 653 int flags; 654 { 655 struct sigacts *ps; 656 struct proc *p = td->td_proc; 657 658 if (!_SIG_VALID(sig)) 659 return (EINVAL); 660 661 PROC_LOCK(p); 662 ps = p->p_sigacts; 663 mtx_lock(&ps->ps_mtx); 664 if (oact) { 665 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 666 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 667 oact->sa_flags = 0; 668 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 669 oact->sa_flags |= SA_ONSTACK; 670 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 671 oact->sa_flags |= SA_RESTART; 672 if (SIGISMEMBER(ps->ps_sigreset, sig)) 673 oact->sa_flags |= SA_RESETHAND; 674 if (SIGISMEMBER(ps->ps_signodefer, sig)) 675 oact->sa_flags |= SA_NODEFER; 676 if (SIGISMEMBER(ps->ps_siginfo, sig)) 677 oact->sa_flags |= SA_SIGINFO; 678 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 679 oact->sa_flags |= SA_NOCLDSTOP; 680 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 681 oact->sa_flags |= SA_NOCLDWAIT; 682 } 683 if (act) { 684 if ((sig == SIGKILL || sig == SIGSTOP) && 685 act->sa_handler != SIG_DFL) { 686 mtx_unlock(&ps->ps_mtx); 687 PROC_UNLOCK(p); 688 return (EINVAL); 689 } 690 691 /* 692 * Change setting atomically. 693 */ 694 695 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 696 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 697 if (act->sa_flags & SA_SIGINFO) { 698 ps->ps_sigact[_SIG_IDX(sig)] = 699 (__sighandler_t *)act->sa_sigaction; 700 SIGADDSET(ps->ps_siginfo, sig); 701 } else { 702 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 703 SIGDELSET(ps->ps_siginfo, sig); 704 } 705 if (!(act->sa_flags & SA_RESTART)) 706 SIGADDSET(ps->ps_sigintr, sig); 707 else 708 SIGDELSET(ps->ps_sigintr, sig); 709 if (act->sa_flags & SA_ONSTACK) 710 SIGADDSET(ps->ps_sigonstack, sig); 711 else 712 SIGDELSET(ps->ps_sigonstack, sig); 713 if (act->sa_flags & SA_RESETHAND) 714 SIGADDSET(ps->ps_sigreset, sig); 715 else 716 SIGDELSET(ps->ps_sigreset, sig); 717 if (act->sa_flags & SA_NODEFER) 718 SIGADDSET(ps->ps_signodefer, sig); 719 else 720 SIGDELSET(ps->ps_signodefer, sig); 721 if (sig == SIGCHLD) { 722 if (act->sa_flags & SA_NOCLDSTOP) 723 ps->ps_flag |= PS_NOCLDSTOP; 724 else 725 ps->ps_flag &= ~PS_NOCLDSTOP; 726 if (act->sa_flags & SA_NOCLDWAIT) { 727 /* 728 * Paranoia: since SA_NOCLDWAIT is implemented 729 * by reparenting the dying child to PID 1 (and 730 * trust it to reap the zombie), PID 1 itself 731 * is forbidden to set SA_NOCLDWAIT. 732 */ 733 if (p->p_pid == 1) 734 ps->ps_flag &= ~PS_NOCLDWAIT; 735 else 736 ps->ps_flag |= PS_NOCLDWAIT; 737 } else 738 ps->ps_flag &= ~PS_NOCLDWAIT; 739 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 740 ps->ps_flag |= PS_CLDSIGIGN; 741 else 742 ps->ps_flag &= ~PS_CLDSIGIGN; 743 } 744 /* 745 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 746 * and for signals set to SIG_DFL where the default is to 747 * ignore. However, don't put SIGCONT in ps_sigignore, as we 748 * have to restart the process. 749 */ 750 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 751 (sigprop(sig) & SA_IGNORE && 752 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 753 #ifdef KSE 754 if ((p->p_flag & P_SA) && 755 SIGISMEMBER(p->p_sigqueue.sq_signals, sig)) { 756 p->p_flag |= P_SIGEVENT; 757 wakeup(&p->p_siglist); 758 } 759 #endif 760 /* never to be seen again */ 761 PROC_SLOCK(p); 762 sigqueue_delete_proc(p, sig); 763 PROC_SUNLOCK(p); 764 if (sig != SIGCONT) 765 /* easier in psignal */ 766 SIGADDSET(ps->ps_sigignore, sig); 767 SIGDELSET(ps->ps_sigcatch, sig); 768 } else { 769 SIGDELSET(ps->ps_sigignore, sig); 770 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 771 SIGDELSET(ps->ps_sigcatch, sig); 772 else 773 SIGADDSET(ps->ps_sigcatch, sig); 774 } 775 #ifdef COMPAT_FREEBSD4 776 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 777 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 778 (flags & KSA_FREEBSD4) == 0) 779 SIGDELSET(ps->ps_freebsd4, sig); 780 else 781 SIGADDSET(ps->ps_freebsd4, sig); 782 #endif 783 #ifdef COMPAT_43 784 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 785 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 786 (flags & KSA_OSIGSET) == 0) 787 SIGDELSET(ps->ps_osigset, sig); 788 else 789 SIGADDSET(ps->ps_osigset, sig); 790 #endif 791 } 792 mtx_unlock(&ps->ps_mtx); 793 PROC_UNLOCK(p); 794 return (0); 795 } 796 797 #ifndef _SYS_SYSPROTO_H_ 798 struct sigaction_args { 799 int sig; 800 struct sigaction *act; 801 struct sigaction *oact; 802 }; 803 #endif 804 int 805 sigaction(td, uap) 806 struct thread *td; 807 register struct sigaction_args *uap; 808 { 809 struct sigaction act, oact; 810 register struct sigaction *actp, *oactp; 811 int error; 812 813 actp = (uap->act != NULL) ? &act : NULL; 814 oactp = (uap->oact != NULL) ? &oact : NULL; 815 if (actp) { 816 error = copyin(uap->act, actp, sizeof(act)); 817 if (error) 818 return (error); 819 } 820 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 821 if (oactp && !error) 822 error = copyout(oactp, uap->oact, sizeof(oact)); 823 return (error); 824 } 825 826 #ifdef COMPAT_FREEBSD4 827 #ifndef _SYS_SYSPROTO_H_ 828 struct freebsd4_sigaction_args { 829 int sig; 830 struct sigaction *act; 831 struct sigaction *oact; 832 }; 833 #endif 834 int 835 freebsd4_sigaction(td, uap) 836 struct thread *td; 837 register struct freebsd4_sigaction_args *uap; 838 { 839 struct sigaction act, oact; 840 register struct sigaction *actp, *oactp; 841 int error; 842 843 844 actp = (uap->act != NULL) ? &act : NULL; 845 oactp = (uap->oact != NULL) ? &oact : NULL; 846 if (actp) { 847 error = copyin(uap->act, actp, sizeof(act)); 848 if (error) 849 return (error); 850 } 851 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 852 if (oactp && !error) 853 error = copyout(oactp, uap->oact, sizeof(oact)); 854 return (error); 855 } 856 #endif /* COMAPT_FREEBSD4 */ 857 858 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 859 #ifndef _SYS_SYSPROTO_H_ 860 struct osigaction_args { 861 int signum; 862 struct osigaction *nsa; 863 struct osigaction *osa; 864 }; 865 #endif 866 int 867 osigaction(td, uap) 868 struct thread *td; 869 register struct osigaction_args *uap; 870 { 871 struct osigaction sa; 872 struct sigaction nsa, osa; 873 register struct sigaction *nsap, *osap; 874 int error; 875 876 if (uap->signum <= 0 || uap->signum >= ONSIG) 877 return (EINVAL); 878 879 nsap = (uap->nsa != NULL) ? &nsa : NULL; 880 osap = (uap->osa != NULL) ? &osa : NULL; 881 882 if (nsap) { 883 error = copyin(uap->nsa, &sa, sizeof(sa)); 884 if (error) 885 return (error); 886 nsap->sa_handler = sa.sa_handler; 887 nsap->sa_flags = sa.sa_flags; 888 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 889 } 890 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 891 if (osap && !error) { 892 sa.sa_handler = osap->sa_handler; 893 sa.sa_flags = osap->sa_flags; 894 SIG2OSIG(osap->sa_mask, sa.sa_mask); 895 error = copyout(&sa, uap->osa, sizeof(sa)); 896 } 897 return (error); 898 } 899 900 #if !defined(__i386__) 901 /* Avoid replicating the same stub everywhere */ 902 int 903 osigreturn(td, uap) 904 struct thread *td; 905 struct osigreturn_args *uap; 906 { 907 908 return (nosys(td, (struct nosys_args *)uap)); 909 } 910 #endif 911 #endif /* COMPAT_43 */ 912 913 /* 914 * Initialize signal state for process 0; 915 * set to ignore signals that are ignored by default. 916 */ 917 void 918 siginit(p) 919 struct proc *p; 920 { 921 register int i; 922 struct sigacts *ps; 923 924 PROC_LOCK(p); 925 ps = p->p_sigacts; 926 mtx_lock(&ps->ps_mtx); 927 for (i = 1; i <= NSIG; i++) 928 if (sigprop(i) & SA_IGNORE && i != SIGCONT) 929 SIGADDSET(ps->ps_sigignore, i); 930 mtx_unlock(&ps->ps_mtx); 931 PROC_UNLOCK(p); 932 } 933 934 /* 935 * Reset signals for an exec of the specified process. 936 */ 937 void 938 execsigs(struct proc *p) 939 { 940 struct sigacts *ps; 941 int sig; 942 struct thread *td; 943 944 /* 945 * Reset caught signals. Held signals remain held 946 * through td_sigmask (unless they were caught, 947 * and are now ignored by default). 948 */ 949 PROC_LOCK_ASSERT(p, MA_OWNED); 950 td = FIRST_THREAD_IN_PROC(p); 951 ps = p->p_sigacts; 952 mtx_lock(&ps->ps_mtx); 953 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 954 sig = sig_ffs(&ps->ps_sigcatch); 955 SIGDELSET(ps->ps_sigcatch, sig); 956 if (sigprop(sig) & SA_IGNORE) { 957 if (sig != SIGCONT) 958 SIGADDSET(ps->ps_sigignore, sig); 959 PROC_SLOCK(p); 960 sigqueue_delete_proc(p, sig); 961 PROC_SUNLOCK(p); 962 } 963 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 964 } 965 /* 966 * Reset stack state to the user stack. 967 * Clear set of signals caught on the signal stack. 968 */ 969 td->td_sigstk.ss_flags = SS_DISABLE; 970 td->td_sigstk.ss_size = 0; 971 td->td_sigstk.ss_sp = 0; 972 td->td_pflags &= ~TDP_ALTSTACK; 973 /* 974 * Reset no zombies if child dies flag as Solaris does. 975 */ 976 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 977 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 978 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 979 mtx_unlock(&ps->ps_mtx); 980 } 981 982 /* 983 * kern_sigprocmask() 984 * 985 * Manipulate signal mask. 986 */ 987 int 988 kern_sigprocmask(td, how, set, oset, old) 989 struct thread *td; 990 int how; 991 sigset_t *set, *oset; 992 int old; 993 { 994 int error; 995 996 PROC_LOCK(td->td_proc); 997 if (oset != NULL) 998 *oset = td->td_sigmask; 999 1000 error = 0; 1001 if (set != NULL) { 1002 switch (how) { 1003 case SIG_BLOCK: 1004 SIG_CANTMASK(*set); 1005 SIGSETOR(td->td_sigmask, *set); 1006 break; 1007 case SIG_UNBLOCK: 1008 SIGSETNAND(td->td_sigmask, *set); 1009 signotify(td); 1010 break; 1011 case SIG_SETMASK: 1012 SIG_CANTMASK(*set); 1013 if (old) 1014 SIGSETLO(td->td_sigmask, *set); 1015 else 1016 td->td_sigmask = *set; 1017 signotify(td); 1018 break; 1019 default: 1020 error = EINVAL; 1021 break; 1022 } 1023 } 1024 PROC_UNLOCK(td->td_proc); 1025 return (error); 1026 } 1027 1028 #ifndef _SYS_SYSPROTO_H_ 1029 struct sigprocmask_args { 1030 int how; 1031 const sigset_t *set; 1032 sigset_t *oset; 1033 }; 1034 #endif 1035 int 1036 sigprocmask(td, uap) 1037 register struct thread *td; 1038 struct sigprocmask_args *uap; 1039 { 1040 sigset_t set, oset; 1041 sigset_t *setp, *osetp; 1042 int error; 1043 1044 setp = (uap->set != NULL) ? &set : NULL; 1045 osetp = (uap->oset != NULL) ? &oset : NULL; 1046 if (setp) { 1047 error = copyin(uap->set, setp, sizeof(set)); 1048 if (error) 1049 return (error); 1050 } 1051 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1052 if (osetp && !error) { 1053 error = copyout(osetp, uap->oset, sizeof(oset)); 1054 } 1055 return (error); 1056 } 1057 1058 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1059 #ifndef _SYS_SYSPROTO_H_ 1060 struct osigprocmask_args { 1061 int how; 1062 osigset_t mask; 1063 }; 1064 #endif 1065 int 1066 osigprocmask(td, uap) 1067 register struct thread *td; 1068 struct osigprocmask_args *uap; 1069 { 1070 sigset_t set, oset; 1071 int error; 1072 1073 OSIG2SIG(uap->mask, set); 1074 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1075 SIG2OSIG(oset, td->td_retval[0]); 1076 return (error); 1077 } 1078 #endif /* COMPAT_43 */ 1079 1080 int 1081 sigwait(struct thread *td, struct sigwait_args *uap) 1082 { 1083 ksiginfo_t ksi; 1084 sigset_t set; 1085 int error; 1086 1087 error = copyin(uap->set, &set, sizeof(set)); 1088 if (error) { 1089 td->td_retval[0] = error; 1090 return (0); 1091 } 1092 1093 error = kern_sigtimedwait(td, set, &ksi, NULL); 1094 if (error) { 1095 if (error == ERESTART) 1096 return (error); 1097 td->td_retval[0] = error; 1098 return (0); 1099 } 1100 1101 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1102 td->td_retval[0] = error; 1103 return (0); 1104 } 1105 1106 int 1107 sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1108 { 1109 struct timespec ts; 1110 struct timespec *timeout; 1111 sigset_t set; 1112 ksiginfo_t ksi; 1113 int error; 1114 1115 if (uap->timeout) { 1116 error = copyin(uap->timeout, &ts, sizeof(ts)); 1117 if (error) 1118 return (error); 1119 1120 timeout = &ts; 1121 } else 1122 timeout = NULL; 1123 1124 error = copyin(uap->set, &set, sizeof(set)); 1125 if (error) 1126 return (error); 1127 1128 error = kern_sigtimedwait(td, set, &ksi, timeout); 1129 if (error) 1130 return (error); 1131 1132 if (uap->info) 1133 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1134 1135 if (error == 0) 1136 td->td_retval[0] = ksi.ksi_signo; 1137 return (error); 1138 } 1139 1140 int 1141 sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1142 { 1143 ksiginfo_t ksi; 1144 sigset_t set; 1145 int error; 1146 1147 error = copyin(uap->set, &set, sizeof(set)); 1148 if (error) 1149 return (error); 1150 1151 error = kern_sigtimedwait(td, set, &ksi, NULL); 1152 if (error) 1153 return (error); 1154 1155 if (uap->info) 1156 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1157 1158 if (error == 0) 1159 td->td_retval[0] = ksi.ksi_signo; 1160 return (error); 1161 } 1162 1163 int 1164 kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1165 struct timespec *timeout) 1166 { 1167 struct sigacts *ps; 1168 sigset_t savedmask; 1169 struct proc *p; 1170 int error, sig, hz, i, timevalid = 0; 1171 struct timespec rts, ets, ts; 1172 struct timeval tv; 1173 1174 p = td->td_proc; 1175 error = 0; 1176 sig = 0; 1177 ets.tv_sec = 0; 1178 ets.tv_nsec = 0; 1179 SIG_CANTMASK(waitset); 1180 1181 PROC_LOCK(p); 1182 ps = p->p_sigacts; 1183 savedmask = td->td_sigmask; 1184 if (timeout) { 1185 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1186 timevalid = 1; 1187 getnanouptime(&rts); 1188 ets = rts; 1189 timespecadd(&ets, timeout); 1190 } 1191 } 1192 1193 restart: 1194 for (i = 1; i <= _SIG_MAXSIG; ++i) { 1195 if (!SIGISMEMBER(waitset, i)) 1196 continue; 1197 if (!SIGISMEMBER(td->td_sigqueue.sq_signals, i)) { 1198 if (SIGISMEMBER(p->p_sigqueue.sq_signals, i)) { 1199 #ifdef KSE 1200 if (p->p_flag & P_SA) { 1201 p->p_flag |= P_SIGEVENT; 1202 wakeup(&p->p_siglist); 1203 } 1204 #endif 1205 sigqueue_move(&p->p_sigqueue, 1206 &td->td_sigqueue, i); 1207 } else 1208 continue; 1209 } 1210 1211 SIGFILLSET(td->td_sigmask); 1212 SIG_CANTMASK(td->td_sigmask); 1213 SIGDELSET(td->td_sigmask, i); 1214 mtx_lock(&ps->ps_mtx); 1215 sig = cursig(td); 1216 mtx_unlock(&ps->ps_mtx); 1217 if (sig) 1218 goto out; 1219 else { 1220 /* 1221 * Because cursig() may have stopped current thread, 1222 * after it is resumed, things may have already been 1223 * changed, it should rescan any pending signals. 1224 */ 1225 goto restart; 1226 } 1227 } 1228 1229 if (error) 1230 goto out; 1231 1232 /* 1233 * POSIX says this must be checked after looking for pending 1234 * signals. 1235 */ 1236 if (timeout) { 1237 if (!timevalid) { 1238 error = EINVAL; 1239 goto out; 1240 } 1241 getnanouptime(&rts); 1242 if (timespeccmp(&rts, &ets, >=)) { 1243 error = EAGAIN; 1244 goto out; 1245 } 1246 ts = ets; 1247 timespecsub(&ts, &rts); 1248 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1249 hz = tvtohz(&tv); 1250 } else 1251 hz = 0; 1252 1253 td->td_sigmask = savedmask; 1254 SIGSETNAND(td->td_sigmask, waitset); 1255 signotify(td); 1256 error = msleep(&ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", hz); 1257 if (timeout) { 1258 if (error == ERESTART) { 1259 /* timeout can not be restarted. */ 1260 error = EINTR; 1261 } else if (error == EAGAIN) { 1262 /* will calculate timeout by ourself. */ 1263 error = 0; 1264 } 1265 } 1266 goto restart; 1267 1268 out: 1269 td->td_sigmask = savedmask; 1270 signotify(td); 1271 if (sig) { 1272 ksiginfo_init(ksi); 1273 sigqueue_get(&td->td_sigqueue, sig, ksi); 1274 ksi->ksi_signo = sig; 1275 if (ksi->ksi_code == SI_TIMER) 1276 itimer_accept(p, ksi->ksi_timerid, ksi); 1277 error = 0; 1278 1279 #ifdef KTRACE 1280 if (KTRPOINT(td, KTR_PSIG)) { 1281 sig_t action; 1282 1283 mtx_lock(&ps->ps_mtx); 1284 action = ps->ps_sigact[_SIG_IDX(sig)]; 1285 mtx_unlock(&ps->ps_mtx); 1286 ktrpsig(sig, action, &td->td_sigmask, 0); 1287 } 1288 #endif 1289 if (sig == SIGKILL) 1290 sigexit(td, sig); 1291 } 1292 PROC_UNLOCK(p); 1293 return (error); 1294 } 1295 1296 #ifndef _SYS_SYSPROTO_H_ 1297 struct sigpending_args { 1298 sigset_t *set; 1299 }; 1300 #endif 1301 int 1302 sigpending(td, uap) 1303 struct thread *td; 1304 struct sigpending_args *uap; 1305 { 1306 struct proc *p = td->td_proc; 1307 sigset_t pending; 1308 1309 PROC_LOCK(p); 1310 pending = p->p_sigqueue.sq_signals; 1311 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1312 PROC_UNLOCK(p); 1313 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1314 } 1315 1316 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1317 #ifndef _SYS_SYSPROTO_H_ 1318 struct osigpending_args { 1319 int dummy; 1320 }; 1321 #endif 1322 int 1323 osigpending(td, uap) 1324 struct thread *td; 1325 struct osigpending_args *uap; 1326 { 1327 struct proc *p = td->td_proc; 1328 sigset_t pending; 1329 1330 PROC_LOCK(p); 1331 pending = p->p_sigqueue.sq_signals; 1332 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1333 PROC_UNLOCK(p); 1334 SIG2OSIG(pending, td->td_retval[0]); 1335 return (0); 1336 } 1337 #endif /* COMPAT_43 */ 1338 1339 #if defined(COMPAT_43) 1340 /* 1341 * Generalized interface signal handler, 4.3-compatible. 1342 */ 1343 #ifndef _SYS_SYSPROTO_H_ 1344 struct osigvec_args { 1345 int signum; 1346 struct sigvec *nsv; 1347 struct sigvec *osv; 1348 }; 1349 #endif 1350 /* ARGSUSED */ 1351 int 1352 osigvec(td, uap) 1353 struct thread *td; 1354 register struct osigvec_args *uap; 1355 { 1356 struct sigvec vec; 1357 struct sigaction nsa, osa; 1358 register struct sigaction *nsap, *osap; 1359 int error; 1360 1361 if (uap->signum <= 0 || uap->signum >= ONSIG) 1362 return (EINVAL); 1363 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1364 osap = (uap->osv != NULL) ? &osa : NULL; 1365 if (nsap) { 1366 error = copyin(uap->nsv, &vec, sizeof(vec)); 1367 if (error) 1368 return (error); 1369 nsap->sa_handler = vec.sv_handler; 1370 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1371 nsap->sa_flags = vec.sv_flags; 1372 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1373 } 1374 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1375 if (osap && !error) { 1376 vec.sv_handler = osap->sa_handler; 1377 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1378 vec.sv_flags = osap->sa_flags; 1379 vec.sv_flags &= ~SA_NOCLDWAIT; 1380 vec.sv_flags ^= SA_RESTART; 1381 error = copyout(&vec, uap->osv, sizeof(vec)); 1382 } 1383 return (error); 1384 } 1385 1386 #ifndef _SYS_SYSPROTO_H_ 1387 struct osigblock_args { 1388 int mask; 1389 }; 1390 #endif 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 int 1414 osigsetmask(td, uap) 1415 struct thread *td; 1416 struct osigsetmask_args *uap; 1417 { 1418 struct proc *p = td->td_proc; 1419 sigset_t set; 1420 1421 OSIG2SIG(uap->mask, set); 1422 SIG_CANTMASK(set); 1423 PROC_LOCK(p); 1424 SIG2OSIG(td->td_sigmask, td->td_retval[0]); 1425 SIGSETLO(td->td_sigmask, set); 1426 signotify(td); 1427 PROC_UNLOCK(p); 1428 return (0); 1429 } 1430 #endif /* COMPAT_43 */ 1431 1432 /* 1433 * Suspend calling thread until signal, providing mask to be set in the 1434 * meantime. 1435 */ 1436 #ifndef _SYS_SYSPROTO_H_ 1437 struct sigsuspend_args { 1438 const sigset_t *sigmask; 1439 }; 1440 #endif 1441 /* ARGSUSED */ 1442 int 1443 sigsuspend(td, uap) 1444 struct thread *td; 1445 struct sigsuspend_args *uap; 1446 { 1447 sigset_t mask; 1448 int error; 1449 1450 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1451 if (error) 1452 return (error); 1453 return (kern_sigsuspend(td, mask)); 1454 } 1455 1456 int 1457 kern_sigsuspend(struct thread *td, sigset_t mask) 1458 { 1459 struct proc *p = td->td_proc; 1460 1461 /* 1462 * When returning from sigsuspend, we want 1463 * the old mask to be restored after the 1464 * signal handler has finished. Thus, we 1465 * save it here and mark the sigacts structure 1466 * to indicate this. 1467 */ 1468 PROC_LOCK(p); 1469 td->td_oldsigmask = td->td_sigmask; 1470 td->td_pflags |= TDP_OLDMASK; 1471 SIG_CANTMASK(mask); 1472 td->td_sigmask = mask; 1473 signotify(td); 1474 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 0) == 0) 1475 /* void */; 1476 PROC_UNLOCK(p); 1477 /* always return EINTR rather than ERESTART... */ 1478 return (EINTR); 1479 } 1480 1481 #ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1482 /* 1483 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1484 * convention: libc stub passes mask, not pointer, to save a copyin. 1485 */ 1486 #ifndef _SYS_SYSPROTO_H_ 1487 struct osigsuspend_args { 1488 osigset_t mask; 1489 }; 1490 #endif 1491 /* ARGSUSED */ 1492 int 1493 osigsuspend(td, uap) 1494 struct thread *td; 1495 struct osigsuspend_args *uap; 1496 { 1497 struct proc *p = td->td_proc; 1498 sigset_t mask; 1499 1500 PROC_LOCK(p); 1501 td->td_oldsigmask = td->td_sigmask; 1502 td->td_pflags |= TDP_OLDMASK; 1503 OSIG2SIG(uap->mask, mask); 1504 SIG_CANTMASK(mask); 1505 SIGSETLO(td->td_sigmask, mask); 1506 signotify(td); 1507 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "opause", 0) == 0) 1508 /* void */; 1509 PROC_UNLOCK(p); 1510 /* always return EINTR rather than ERESTART... */ 1511 return (EINTR); 1512 } 1513 #endif /* COMPAT_43 */ 1514 1515 #if defined(COMPAT_43) 1516 #ifndef _SYS_SYSPROTO_H_ 1517 struct osigstack_args { 1518 struct sigstack *nss; 1519 struct sigstack *oss; 1520 }; 1521 #endif 1522 /* ARGSUSED */ 1523 int 1524 osigstack(td, uap) 1525 struct thread *td; 1526 register struct osigstack_args *uap; 1527 { 1528 struct sigstack nss, oss; 1529 int error = 0; 1530 1531 if (uap->nss != NULL) { 1532 error = copyin(uap->nss, &nss, sizeof(nss)); 1533 if (error) 1534 return (error); 1535 } 1536 oss.ss_sp = td->td_sigstk.ss_sp; 1537 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1538 if (uap->nss != NULL) { 1539 td->td_sigstk.ss_sp = nss.ss_sp; 1540 td->td_sigstk.ss_size = 0; 1541 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1542 td->td_pflags |= TDP_ALTSTACK; 1543 } 1544 if (uap->oss != NULL) 1545 error = copyout(&oss, uap->oss, sizeof(oss)); 1546 1547 return (error); 1548 } 1549 #endif /* COMPAT_43 */ 1550 1551 #ifndef _SYS_SYSPROTO_H_ 1552 struct sigaltstack_args { 1553 stack_t *ss; 1554 stack_t *oss; 1555 }; 1556 #endif 1557 /* ARGSUSED */ 1558 int 1559 sigaltstack(td, uap) 1560 struct thread *td; 1561 register struct sigaltstack_args *uap; 1562 { 1563 stack_t ss, oss; 1564 int error; 1565 1566 if (uap->ss != NULL) { 1567 error = copyin(uap->ss, &ss, sizeof(ss)); 1568 if (error) 1569 return (error); 1570 } 1571 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1572 (uap->oss != NULL) ? &oss : NULL); 1573 if (error) 1574 return (error); 1575 if (uap->oss != NULL) 1576 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1577 return (error); 1578 } 1579 1580 int 1581 kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1582 { 1583 struct proc *p = td->td_proc; 1584 int oonstack; 1585 1586 oonstack = sigonstack(cpu_getstack(td)); 1587 1588 if (oss != NULL) { 1589 *oss = td->td_sigstk; 1590 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1591 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1592 } 1593 1594 if (ss != NULL) { 1595 if (oonstack) 1596 return (EPERM); 1597 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1598 return (EINVAL); 1599 if (!(ss->ss_flags & SS_DISABLE)) { 1600 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1601 return (ENOMEM); 1602 1603 td->td_sigstk = *ss; 1604 td->td_pflags |= TDP_ALTSTACK; 1605 } else { 1606 td->td_pflags &= ~TDP_ALTSTACK; 1607 } 1608 } 1609 return (0); 1610 } 1611 1612 /* 1613 * Common code for kill process group/broadcast kill. 1614 * cp is calling process. 1615 */ 1616 static int 1617 killpg1(td, sig, pgid, all) 1618 register struct thread *td; 1619 int sig, pgid, all; 1620 { 1621 register struct proc *p; 1622 struct pgrp *pgrp; 1623 int nfound = 0; 1624 1625 if (all) { 1626 /* 1627 * broadcast 1628 */ 1629 sx_slock(&allproc_lock); 1630 FOREACH_PROC_IN_SYSTEM(p) { 1631 PROC_LOCK(p); 1632 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1633 p == td->td_proc || p->p_state == PRS_NEW) { 1634 PROC_UNLOCK(p); 1635 continue; 1636 } 1637 if (p_cansignal(td, p, sig) == 0) { 1638 nfound++; 1639 if (sig) 1640 psignal(p, sig); 1641 } 1642 PROC_UNLOCK(p); 1643 } 1644 sx_sunlock(&allproc_lock); 1645 } else { 1646 sx_slock(&proctree_lock); 1647 if (pgid == 0) { 1648 /* 1649 * zero pgid means send to my process group. 1650 */ 1651 pgrp = td->td_proc->p_pgrp; 1652 PGRP_LOCK(pgrp); 1653 } else { 1654 pgrp = pgfind(pgid); 1655 if (pgrp == NULL) { 1656 sx_sunlock(&proctree_lock); 1657 return (ESRCH); 1658 } 1659 } 1660 sx_sunlock(&proctree_lock); 1661 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1662 PROC_LOCK(p); 1663 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1664 p->p_state == PRS_NEW ) { 1665 PROC_UNLOCK(p); 1666 continue; 1667 } 1668 if (p_cansignal(td, p, sig) == 0) { 1669 nfound++; 1670 if (sig) 1671 psignal(p, sig); 1672 } 1673 PROC_UNLOCK(p); 1674 } 1675 PGRP_UNLOCK(pgrp); 1676 } 1677 return (nfound ? 0 : ESRCH); 1678 } 1679 1680 #ifndef _SYS_SYSPROTO_H_ 1681 struct kill_args { 1682 int pid; 1683 int signum; 1684 }; 1685 #endif 1686 /* ARGSUSED */ 1687 int 1688 kill(td, uap) 1689 register struct thread *td; 1690 register struct kill_args *uap; 1691 { 1692 register struct proc *p; 1693 int error; 1694 1695 AUDIT_ARG(signum, uap->signum); 1696 if ((u_int)uap->signum > _SIG_MAXSIG) 1697 return (EINVAL); 1698 1699 if (uap->pid > 0) { 1700 /* kill single process */ 1701 if ((p = pfind(uap->pid)) == NULL) { 1702 if ((p = zpfind(uap->pid)) == NULL) 1703 return (ESRCH); 1704 } 1705 AUDIT_ARG(process, p); 1706 error = p_cansignal(td, p, uap->signum); 1707 if (error == 0 && uap->signum) 1708 psignal(p, uap->signum); 1709 PROC_UNLOCK(p); 1710 return (error); 1711 } 1712 AUDIT_ARG(pid, uap->pid); 1713 switch (uap->pid) { 1714 case -1: /* broadcast signal */ 1715 return (killpg1(td, uap->signum, 0, 1)); 1716 case 0: /* signal own process group */ 1717 return (killpg1(td, uap->signum, 0, 0)); 1718 default: /* negative explicit process group */ 1719 return (killpg1(td, uap->signum, -uap->pid, 0)); 1720 } 1721 /* NOTREACHED */ 1722 } 1723 1724 #if defined(COMPAT_43) 1725 #ifndef _SYS_SYSPROTO_H_ 1726 struct okillpg_args { 1727 int pgid; 1728 int signum; 1729 }; 1730 #endif 1731 /* ARGSUSED */ 1732 int 1733 okillpg(td, uap) 1734 struct thread *td; 1735 register struct okillpg_args *uap; 1736 { 1737 1738 AUDIT_ARG(signum, uap->signum); 1739 AUDIT_ARG(pid, uap->pgid); 1740 if ((u_int)uap->signum > _SIG_MAXSIG) 1741 return (EINVAL); 1742 1743 return (killpg1(td, uap->signum, uap->pgid, 0)); 1744 } 1745 #endif /* COMPAT_43 */ 1746 1747 #ifndef _SYS_SYSPROTO_H_ 1748 struct sigqueue_args { 1749 pid_t pid; 1750 int signum; 1751 /* union sigval */ void *value; 1752 }; 1753 #endif 1754 int 1755 sigqueue(struct thread *td, struct sigqueue_args *uap) 1756 { 1757 ksiginfo_t ksi; 1758 struct proc *p; 1759 int error; 1760 1761 if ((u_int)uap->signum > _SIG_MAXSIG) 1762 return (EINVAL); 1763 1764 /* 1765 * Specification says sigqueue can only send signal to 1766 * single process. 1767 */ 1768 if (uap->pid <= 0) 1769 return (EINVAL); 1770 1771 if ((p = pfind(uap->pid)) == NULL) { 1772 if ((p = zpfind(uap->pid)) == NULL) 1773 return (ESRCH); 1774 } 1775 error = p_cansignal(td, p, uap->signum); 1776 if (error == 0 && uap->signum != 0) { 1777 ksiginfo_init(&ksi); 1778 ksi.ksi_signo = uap->signum; 1779 ksi.ksi_code = SI_QUEUE; 1780 ksi.ksi_pid = td->td_proc->p_pid; 1781 ksi.ksi_uid = td->td_ucred->cr_ruid; 1782 ksi.ksi_value.sival_ptr = uap->value; 1783 error = tdsignal(p, NULL, ksi.ksi_signo, &ksi); 1784 } 1785 PROC_UNLOCK(p); 1786 return (error); 1787 } 1788 1789 /* 1790 * Send a signal to a process group. 1791 */ 1792 void 1793 gsignal(pgid, sig) 1794 int pgid, sig; 1795 { 1796 struct pgrp *pgrp; 1797 1798 if (pgid != 0) { 1799 sx_slock(&proctree_lock); 1800 pgrp = pgfind(pgid); 1801 sx_sunlock(&proctree_lock); 1802 if (pgrp != NULL) { 1803 pgsignal(pgrp, sig, 0); 1804 PGRP_UNLOCK(pgrp); 1805 } 1806 } 1807 } 1808 1809 /* 1810 * Send a signal to a process group. If checktty is 1, 1811 * limit to members which have a controlling terminal. 1812 */ 1813 void 1814 pgsignal(pgrp, sig, checkctty) 1815 struct pgrp *pgrp; 1816 int sig, checkctty; 1817 { 1818 register struct proc *p; 1819 1820 if (pgrp) { 1821 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1822 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1823 PROC_LOCK(p); 1824 if (checkctty == 0 || p->p_flag & P_CONTROLT) 1825 psignal(p, sig); 1826 PROC_UNLOCK(p); 1827 } 1828 } 1829 } 1830 1831 /* 1832 * Send a signal caused by a trap to the current thread. If it will be 1833 * caught immediately, deliver it with correct code. Otherwise, post it 1834 * normally. 1835 */ 1836 void 1837 trapsignal(struct thread *td, ksiginfo_t *ksi) 1838 { 1839 struct sigacts *ps; 1840 struct proc *p; 1841 #ifdef KSE 1842 int error; 1843 #endif 1844 int sig; 1845 int code; 1846 1847 p = td->td_proc; 1848 sig = ksi->ksi_signo; 1849 code = ksi->ksi_code; 1850 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1851 1852 #ifdef KSE 1853 if (td->td_pflags & TDP_SA) { 1854 if (td->td_mailbox == NULL) 1855 thread_user_enter(td); 1856 PROC_LOCK(p); 1857 SIGDELSET(td->td_sigmask, sig); 1858 thread_lock(td); 1859 /* 1860 * Force scheduling an upcall, so UTS has chance to 1861 * process the signal before thread runs again in 1862 * userland. 1863 */ 1864 if (td->td_upcall) 1865 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1866 thread_unlock(td); 1867 } else { 1868 PROC_LOCK(p); 1869 } 1870 #else 1871 PROC_LOCK(p); 1872 #endif 1873 ps = p->p_sigacts; 1874 mtx_lock(&ps->ps_mtx); 1875 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1876 !SIGISMEMBER(td->td_sigmask, sig)) { 1877 td->td_ru.ru_nsignals++; 1878 #ifdef KTRACE 1879 if (KTRPOINT(curthread, KTR_PSIG)) 1880 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1881 &td->td_sigmask, code); 1882 #endif 1883 #ifdef KSE 1884 if (!(td->td_pflags & TDP_SA)) 1885 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1886 ksi, &td->td_sigmask); 1887 #else 1888 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1889 ksi, &td->td_sigmask); 1890 #endif 1891 #ifdef KSE 1892 else if (td->td_mailbox == NULL) { 1893 mtx_unlock(&ps->ps_mtx); 1894 /* UTS caused a sync signal */ 1895 p->p_code = code; /* XXX for core dump/debugger */ 1896 p->p_sig = sig; /* XXX to verify code */ 1897 sigexit(td, sig); 1898 } else { 1899 mtx_unlock(&ps->ps_mtx); 1900 SIGADDSET(td->td_sigmask, sig); 1901 PROC_UNLOCK(p); 1902 error = copyout(&ksi->ksi_info, &td->td_mailbox->tm_syncsig, 1903 sizeof(siginfo_t)); 1904 PROC_LOCK(p); 1905 /* UTS memory corrupted */ 1906 if (error) 1907 sigexit(td, SIGSEGV); 1908 mtx_lock(&ps->ps_mtx); 1909 } 1910 #endif 1911 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 1912 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1913 SIGADDSET(td->td_sigmask, sig); 1914 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 1915 /* 1916 * See kern_sigaction() for origin of this code. 1917 */ 1918 SIGDELSET(ps->ps_sigcatch, sig); 1919 if (sig != SIGCONT && 1920 sigprop(sig) & SA_IGNORE) 1921 SIGADDSET(ps->ps_sigignore, sig); 1922 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1923 } 1924 mtx_unlock(&ps->ps_mtx); 1925 } else { 1926 /* 1927 * Avoid a possible infinite loop if the thread 1928 * masking the signal or process is ignoring the 1929 * signal. 1930 */ 1931 if (kern_forcesigexit && 1932 (SIGISMEMBER(td->td_sigmask, sig) || 1933 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1934 SIGDELSET(td->td_sigmask, sig); 1935 SIGDELSET(ps->ps_sigcatch, sig); 1936 SIGDELSET(ps->ps_sigignore, sig); 1937 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1938 } 1939 mtx_unlock(&ps->ps_mtx); 1940 p->p_code = code; /* XXX for core dump/debugger */ 1941 p->p_sig = sig; /* XXX to verify code */ 1942 tdsignal(p, td, sig, ksi); 1943 } 1944 PROC_UNLOCK(p); 1945 } 1946 1947 static struct thread * 1948 sigtd(struct proc *p, int sig, int prop) 1949 { 1950 struct thread *td, *signal_td; 1951 1952 PROC_LOCK_ASSERT(p, MA_OWNED); 1953 1954 /* 1955 * Check if current thread can handle the signal without 1956 * switching conetxt to another thread. 1957 */ 1958 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1959 return (curthread); 1960 signal_td = NULL; 1961 PROC_SLOCK(p); 1962 FOREACH_THREAD_IN_PROC(p, td) { 1963 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1964 signal_td = td; 1965 break; 1966 } 1967 } 1968 if (signal_td == NULL) 1969 signal_td = FIRST_THREAD_IN_PROC(p); 1970 PROC_SUNLOCK(p); 1971 return (signal_td); 1972 } 1973 1974 /* 1975 * Send the signal to the process. If the signal has an action, the action 1976 * is usually performed by the target process rather than the caller; we add 1977 * the signal to the set of pending signals for the process. 1978 * 1979 * Exceptions: 1980 * o When a stop signal is sent to a sleeping process that takes the 1981 * default action, the process is stopped without awakening it. 1982 * o SIGCONT restarts stopped processes (or puts them back to sleep) 1983 * regardless of the signal action (eg, blocked or ignored). 1984 * 1985 * Other ignored signals are discarded immediately. 1986 * 1987 * NB: This function may be entered from the debugger via the "kill" DDB 1988 * command. There is little that can be done to mitigate the possibly messy 1989 * side effects of this unwise possibility. 1990 */ 1991 void 1992 psignal(struct proc *p, int sig) 1993 { 1994 (void) tdsignal(p, NULL, sig, NULL); 1995 } 1996 1997 int 1998 psignal_event(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi) 1999 { 2000 struct thread *td = NULL; 2001 2002 PROC_LOCK_ASSERT(p, MA_OWNED); 2003 2004 KASSERT(!KSI_ONQ(ksi), ("psignal_event: ksi on queue")); 2005 2006 /* 2007 * ksi_code and other fields should be set before 2008 * calling this function. 2009 */ 2010 ksi->ksi_signo = sigev->sigev_signo; 2011 ksi->ksi_value = sigev->sigev_value; 2012 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2013 td = thread_find(p, sigev->sigev_notify_thread_id); 2014 if (td == NULL) 2015 return (ESRCH); 2016 } 2017 return (tdsignal(p, td, ksi->ksi_signo, ksi)); 2018 } 2019 2020 int 2021 tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2022 { 2023 #ifdef KSE 2024 sigset_t saved; 2025 int ret; 2026 2027 if (p->p_flag & P_SA) 2028 saved = p->p_sigqueue.sq_signals; 2029 ret = do_tdsignal(p, td, sig, ksi); 2030 if ((p->p_flag & P_SA) && !(p->p_flag & P_SIGEVENT)) { 2031 if (!SIGSETEQ(saved, p->p_sigqueue.sq_signals)) { 2032 /* pending set changed */ 2033 p->p_flag |= P_SIGEVENT; 2034 wakeup(&p->p_siglist); 2035 } 2036 } 2037 return (ret); 2038 } 2039 2040 static int 2041 do_tdsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2042 { 2043 #endif 2044 sig_t action; 2045 sigqueue_t *sigqueue; 2046 int prop; 2047 struct sigacts *ps; 2048 int intrval; 2049 int ret = 0; 2050 2051 PROC_LOCK_ASSERT(p, MA_OWNED); 2052 2053 if (!_SIG_VALID(sig)) 2054 #ifdef KSE 2055 panic("do_tdsignal(): invalid signal %d", sig); 2056 #else 2057 panic("tdsignal(): invalid signal %d", sig); 2058 #endif 2059 2060 #ifdef KSE 2061 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("do_tdsignal: ksi on queue")); 2062 #else 2063 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("tdsignal: ksi on queue")); 2064 #endif 2065 2066 /* 2067 * IEEE Std 1003.1-2001: return success when killing a zombie. 2068 */ 2069 if (p->p_state == PRS_ZOMBIE) { 2070 if (ksi && (ksi->ksi_flags & KSI_INS)) 2071 ksiginfo_tryfree(ksi); 2072 return (ret); 2073 } 2074 2075 ps = p->p_sigacts; 2076 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2077 prop = sigprop(sig); 2078 2079 /* 2080 * If the signal is blocked and not destined for this thread, then 2081 * assign it to the process so that we can find it later in the first 2082 * thread that unblocks it. Otherwise, assign it to this thread now. 2083 */ 2084 if (td == NULL) { 2085 td = sigtd(p, sig, prop); 2086 if (SIGISMEMBER(td->td_sigmask, sig)) 2087 sigqueue = &p->p_sigqueue; 2088 else 2089 sigqueue = &td->td_sigqueue; 2090 } else { 2091 KASSERT(td->td_proc == p, ("invalid thread")); 2092 sigqueue = &td->td_sigqueue; 2093 } 2094 2095 /* 2096 * If the signal is being ignored, 2097 * then we forget about it immediately. 2098 * (Note: we don't set SIGCONT in ps_sigignore, 2099 * and if it is set to SIG_IGN, 2100 * action will be SIG_DFL here.) 2101 */ 2102 mtx_lock(&ps->ps_mtx); 2103 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2104 mtx_unlock(&ps->ps_mtx); 2105 if (ksi && (ksi->ksi_flags & KSI_INS)) 2106 ksiginfo_tryfree(ksi); 2107 return (ret); 2108 } 2109 if (SIGISMEMBER(td->td_sigmask, sig)) 2110 action = SIG_HOLD; 2111 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2112 action = SIG_CATCH; 2113 else 2114 action = SIG_DFL; 2115 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2116 intrval = EINTR; 2117 else 2118 intrval = ERESTART; 2119 mtx_unlock(&ps->ps_mtx); 2120 2121 if (prop & SA_CONT) 2122 sigqueue_delete_stopmask_proc(p); 2123 else if (prop & SA_STOP) { 2124 /* 2125 * If sending a tty stop signal to a member of an orphaned 2126 * process group, discard the signal here if the action 2127 * is default; don't stop the process below if sleeping, 2128 * and don't clear any pending SIGCONT. 2129 */ 2130 if ((prop & SA_TTYSTOP) && 2131 (p->p_pgrp->pg_jobc == 0) && 2132 (action == SIG_DFL)) { 2133 if (ksi && (ksi->ksi_flags & KSI_INS)) 2134 ksiginfo_tryfree(ksi); 2135 return (ret); 2136 } 2137 PROC_SLOCK(p); 2138 sigqueue_delete_proc(p, SIGCONT); 2139 PROC_SUNLOCK(p); 2140 if (p->p_flag & P_CONTINUED) { 2141 p->p_flag &= ~P_CONTINUED; 2142 PROC_LOCK(p->p_pptr); 2143 sigqueue_take(p->p_ksi); 2144 PROC_UNLOCK(p->p_pptr); 2145 } 2146 } 2147 2148 ret = sigqueue_add(sigqueue, sig, ksi); 2149 if (ret != 0) 2150 return (ret); 2151 signotify(td); 2152 /* 2153 * Defer further processing for signals which are held, 2154 * except that stopped processes must be continued by SIGCONT. 2155 */ 2156 if (action == SIG_HOLD && 2157 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2158 return (ret); 2159 /* 2160 * SIGKILL: Remove procfs STOPEVENTs. 2161 */ 2162 if (sig == SIGKILL) { 2163 /* from procfs_ioctl.c: PIOCBIC */ 2164 p->p_stops = 0; 2165 /* from procfs_ioctl.c: PIOCCONT */ 2166 p->p_step = 0; 2167 wakeup(&p->p_step); 2168 } 2169 /* 2170 * Some signals have a process-wide effect and a per-thread 2171 * component. Most processing occurs when the process next 2172 * tries to cross the user boundary, however there are some 2173 * times when processing needs to be done immediatly, such as 2174 * waking up threads so that they can cross the user boundary. 2175 * We try do the per-process part here. 2176 */ 2177 PROC_SLOCK(p); 2178 if (P_SHOULDSTOP(p)) { 2179 /* 2180 * The process is in stopped mode. All the threads should be 2181 * either winding down or already on the suspended queue. 2182 */ 2183 if (p->p_flag & P_TRACED) { 2184 /* 2185 * The traced process is already stopped, 2186 * so no further action is necessary. 2187 * No signal can restart us. 2188 */ 2189 PROC_SUNLOCK(p); 2190 goto out; 2191 } 2192 2193 if (sig == SIGKILL) { 2194 /* 2195 * SIGKILL sets process running. 2196 * It will die elsewhere. 2197 * All threads must be restarted. 2198 */ 2199 p->p_flag &= ~P_STOPPED_SIG; 2200 goto runfast; 2201 } 2202 2203 if (prop & SA_CONT) { 2204 /* 2205 * If SIGCONT is default (or ignored), we continue the 2206 * process but don't leave the signal in sigqueue as 2207 * it has no further action. If SIGCONT is held, we 2208 * continue the process and leave the signal in 2209 * sigqueue. If the process catches SIGCONT, let it 2210 * handle the signal itself. If it isn't waiting on 2211 * an event, it goes back to run state. 2212 * Otherwise, process goes back to sleep state. 2213 */ 2214 p->p_flag &= ~P_STOPPED_SIG; 2215 if (p->p_numthreads == p->p_suspcount) { 2216 PROC_SUNLOCK(p); 2217 p->p_flag |= P_CONTINUED; 2218 p->p_xstat = SIGCONT; 2219 PROC_LOCK(p->p_pptr); 2220 childproc_continued(p); 2221 PROC_UNLOCK(p->p_pptr); 2222 PROC_SLOCK(p); 2223 } 2224 if (action == SIG_DFL) { 2225 thread_unsuspend(p); 2226 PROC_SUNLOCK(p); 2227 sigqueue_delete(sigqueue, sig); 2228 goto out; 2229 } 2230 if (action == SIG_CATCH) { 2231 #ifdef KSE 2232 /* 2233 * The process wants to catch it so it needs 2234 * to run at least one thread, but which one? 2235 * It would seem that the answer would be to 2236 * run an upcall in the next KSE to run, and 2237 * deliver the signal that way. In a NON KSE 2238 * process, we need to make sure that the 2239 * single thread is runnable asap. 2240 * XXXKSE for now however, make them all run. 2241 */ 2242 #endif 2243 /* 2244 * The process wants to catch it so it needs 2245 * to run at least one thread, but which one? 2246 */ 2247 goto runfast; 2248 } 2249 /* 2250 * The signal is not ignored or caught. 2251 */ 2252 thread_unsuspend(p); 2253 PROC_SUNLOCK(p); 2254 goto out; 2255 } 2256 2257 if (prop & SA_STOP) { 2258 /* 2259 * Already stopped, don't need to stop again 2260 * (If we did the shell could get confused). 2261 * Just make sure the signal STOP bit set. 2262 */ 2263 PROC_SUNLOCK(p); 2264 p->p_flag |= P_STOPPED_SIG; 2265 sigqueue_delete(sigqueue, sig); 2266 goto out; 2267 } 2268 2269 /* 2270 * All other kinds of signals: 2271 * If a thread is sleeping interruptibly, simulate a 2272 * wakeup so that when it is continued it will be made 2273 * runnable and can look at the signal. However, don't make 2274 * the PROCESS runnable, leave it stopped. 2275 * It may run a bit until it hits a thread_suspend_check(). 2276 */ 2277 thread_lock(td); 2278 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2279 sleepq_abort(td, intrval); 2280 thread_unlock(td); 2281 PROC_SUNLOCK(p); 2282 goto out; 2283 /* 2284 * Mutexes are short lived. Threads waiting on them will 2285 * hit thread_suspend_check() soon. 2286 */ 2287 } else if (p->p_state == PRS_NORMAL) { 2288 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2289 thread_lock(td); 2290 tdsigwakeup(td, sig, action, intrval); 2291 thread_unlock(td); 2292 PROC_SUNLOCK(p); 2293 goto out; 2294 } 2295 2296 MPASS(action == SIG_DFL); 2297 2298 if (prop & SA_STOP) { 2299 if (p->p_flag & P_PPWAIT) { 2300 PROC_SUNLOCK(p); 2301 goto out; 2302 } 2303 p->p_flag |= P_STOPPED_SIG; 2304 p->p_xstat = sig; 2305 sig_suspend_threads(td, p, 1); 2306 if (p->p_numthreads == p->p_suspcount) { 2307 /* 2308 * only thread sending signal to another 2309 * process can reach here, if thread is sending 2310 * signal to its process, because thread does 2311 * not suspend itself here, p_numthreads 2312 * should never be equal to p_suspcount. 2313 */ 2314 thread_stopped(p); 2315 PROC_SUNLOCK(p); 2316 sigqueue_delete_proc(p, p->p_xstat); 2317 } else 2318 PROC_SUNLOCK(p); 2319 goto out; 2320 } 2321 else 2322 goto runfast; 2323 /* NOTREACHED */ 2324 } else { 2325 /* Not in "NORMAL" state. discard the signal. */ 2326 PROC_SUNLOCK(p); 2327 sigqueue_delete(sigqueue, sig); 2328 goto out; 2329 } 2330 2331 /* 2332 * The process is not stopped so we need to apply the signal to all the 2333 * running threads. 2334 */ 2335 2336 runfast: 2337 thread_lock(td); 2338 tdsigwakeup(td, sig, action, intrval); 2339 thread_unlock(td); 2340 thread_unsuspend(p); 2341 PROC_SUNLOCK(p); 2342 out: 2343 /* If we jump here, proc slock should not be owned. */ 2344 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2345 return (ret); 2346 } 2347 2348 /* 2349 * The force of a signal has been directed against a single 2350 * thread. We need to see what we can do about knocking it 2351 * out of any sleep it may be in etc. 2352 */ 2353 static void 2354 tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2355 { 2356 struct proc *p = td->td_proc; 2357 register int prop; 2358 2359 PROC_LOCK_ASSERT(p, MA_OWNED); 2360 PROC_SLOCK_ASSERT(p, MA_OWNED); 2361 THREAD_LOCK_ASSERT(td, MA_OWNED); 2362 prop = sigprop(sig); 2363 2364 /* 2365 * Bring the priority of a thread up if we want it to get 2366 * killed in this lifetime. 2367 */ 2368 if (action == SIG_DFL && (prop & SA_KILL)) { 2369 if (p->p_nice > 0) 2370 sched_nice(td->td_proc, 0); 2371 if (td->td_priority > PUSER) 2372 sched_prio(td, PUSER); 2373 } 2374 2375 if (TD_ON_SLEEPQ(td)) { 2376 /* 2377 * If thread is sleeping uninterruptibly 2378 * we can't interrupt the sleep... the signal will 2379 * be noticed when the process returns through 2380 * trap() or syscall(). 2381 */ 2382 if ((td->td_flags & TDF_SINTR) == 0) 2383 return; 2384 /* 2385 * If SIGCONT is default (or ignored) and process is 2386 * asleep, we are finished; the process should not 2387 * be awakened. 2388 */ 2389 if ((prop & SA_CONT) && action == SIG_DFL) { 2390 thread_unlock(td); 2391 PROC_SUNLOCK(p); 2392 sigqueue_delete(&p->p_sigqueue, sig); 2393 /* 2394 * It may be on either list in this state. 2395 * Remove from both for now. 2396 */ 2397 sigqueue_delete(&td->td_sigqueue, sig); 2398 PROC_SLOCK(p); 2399 thread_lock(td); 2400 return; 2401 } 2402 2403 /* 2404 * Give low priority threads a better chance to run. 2405 */ 2406 if (td->td_priority > PUSER) 2407 sched_prio(td, PUSER); 2408 2409 sleepq_abort(td, intrval); 2410 } else { 2411 /* 2412 * Other states do nothing with the signal immediately, 2413 * other than kicking ourselves if we are running. 2414 * It will either never be noticed, or noticed very soon. 2415 */ 2416 #ifdef SMP 2417 if (TD_IS_RUNNING(td) && td != curthread) 2418 forward_signal(td); 2419 #endif 2420 } 2421 } 2422 2423 static void 2424 sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2425 { 2426 struct thread *td2; 2427 2428 PROC_LOCK_ASSERT(p, MA_OWNED); 2429 PROC_SLOCK_ASSERT(p, MA_OWNED); 2430 2431 FOREACH_THREAD_IN_PROC(p, td2) { 2432 thread_lock(td2); 2433 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2434 (td2->td_flags & TDF_SINTR) && 2435 !TD_IS_SUSPENDED(td2)) { 2436 thread_suspend_one(td2); 2437 } else { 2438 if (sending || td != td2) 2439 td2->td_flags |= TDF_ASTPENDING; 2440 #ifdef SMP 2441 if (TD_IS_RUNNING(td2) && td2 != td) 2442 forward_signal(td2); 2443 #endif 2444 } 2445 thread_unlock(td2); 2446 } 2447 } 2448 2449 int 2450 ptracestop(struct thread *td, int sig) 2451 { 2452 struct proc *p = td->td_proc; 2453 2454 PROC_LOCK_ASSERT(p, MA_OWNED); 2455 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2456 &p->p_mtx.lock_object, "Stopping for traced signal"); 2457 2458 thread_lock(td); 2459 td->td_flags |= TDF_XSIG; 2460 thread_unlock(td); 2461 td->td_xsig = sig; 2462 PROC_SLOCK(p); 2463 while ((p->p_flag & P_TRACED) && (td->td_flags & TDF_XSIG)) { 2464 if (p->p_flag & P_SINGLE_EXIT) { 2465 thread_lock(td); 2466 td->td_flags &= ~TDF_XSIG; 2467 thread_unlock(td); 2468 PROC_SUNLOCK(p); 2469 return (sig); 2470 } 2471 /* 2472 * Just make wait() to work, the last stopped thread 2473 * will win. 2474 */ 2475 p->p_xstat = sig; 2476 p->p_xthread = td; 2477 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2478 sig_suspend_threads(td, p, 0); 2479 stopme: 2480 thread_suspend_switch(td); 2481 if (!(p->p_flag & P_TRACED)) { 2482 break; 2483 } 2484 if (td->td_flags & TDF_DBSUSPEND) { 2485 if (p->p_flag & P_SINGLE_EXIT) 2486 break; 2487 goto stopme; 2488 } 2489 } 2490 PROC_SUNLOCK(p); 2491 return (td->td_xsig); 2492 } 2493 2494 /* 2495 * If the current process has received a signal (should be caught or cause 2496 * termination, should interrupt current syscall), return the signal number. 2497 * Stop signals with default action are processed immediately, then cleared; 2498 * they aren't returned. This is checked after each entry to the system for 2499 * a syscall or trap (though this can usually be done without calling issignal 2500 * by checking the pending signal masks in cursig.) The normal call 2501 * sequence is 2502 * 2503 * while (sig = cursig(curthread)) 2504 * postsig(sig); 2505 */ 2506 static int 2507 issignal(td) 2508 struct thread *td; 2509 { 2510 struct proc *p; 2511 struct sigacts *ps; 2512 sigset_t sigpending; 2513 int sig, prop, newsig; 2514 2515 p = td->td_proc; 2516 ps = p->p_sigacts; 2517 mtx_assert(&ps->ps_mtx, MA_OWNED); 2518 PROC_LOCK_ASSERT(p, MA_OWNED); 2519 for (;;) { 2520 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2521 2522 sigpending = td->td_sigqueue.sq_signals; 2523 SIGSETNAND(sigpending, td->td_sigmask); 2524 2525 if (p->p_flag & P_PPWAIT) 2526 SIG_STOPSIGMASK(sigpending); 2527 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2528 return (0); 2529 sig = sig_ffs(&sigpending); 2530 2531 if (p->p_stops & S_SIG) { 2532 mtx_unlock(&ps->ps_mtx); 2533 stopevent(p, S_SIG, sig); 2534 mtx_lock(&ps->ps_mtx); 2535 } 2536 2537 /* 2538 * We should see pending but ignored signals 2539 * only if P_TRACED was on when they were posted. 2540 */ 2541 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2542 sigqueue_delete(&td->td_sigqueue, sig); 2543 #ifdef KSE 2544 if (td->td_pflags & TDP_SA) 2545 SIGADDSET(td->td_sigmask, sig); 2546 #endif 2547 continue; 2548 } 2549 if (p->p_flag & P_TRACED && (p->p_flag & P_PPWAIT) == 0) { 2550 /* 2551 * If traced, always stop. 2552 */ 2553 mtx_unlock(&ps->ps_mtx); 2554 newsig = ptracestop(td, sig); 2555 mtx_lock(&ps->ps_mtx); 2556 2557 #ifdef KSE 2558 if (td->td_pflags & TDP_SA) 2559 SIGADDSET(td->td_sigmask, sig); 2560 2561 #endif 2562 if (sig != newsig) { 2563 ksiginfo_t ksi; 2564 /* 2565 * clear old signal. 2566 * XXX shrug off debugger, it causes siginfo to 2567 * be thrown away. 2568 */ 2569 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2570 2571 /* 2572 * If parent wants us to take the signal, 2573 * then it will leave it in p->p_xstat; 2574 * otherwise we just look for signals again. 2575 */ 2576 if (newsig == 0) 2577 continue; 2578 sig = newsig; 2579 2580 /* 2581 * Put the new signal into td_sigqueue. If the 2582 * signal is being masked, look for other signals. 2583 */ 2584 SIGADDSET(td->td_sigqueue.sq_signals, sig); 2585 #ifdef KSE 2586 if (td->td_pflags & TDP_SA) 2587 SIGDELSET(td->td_sigmask, sig); 2588 #endif 2589 if (SIGISMEMBER(td->td_sigmask, sig)) 2590 continue; 2591 signotify(td); 2592 } 2593 2594 /* 2595 * If the traced bit got turned off, go back up 2596 * to the top to rescan signals. This ensures 2597 * that p_sig* and p_sigact are consistent. 2598 */ 2599 if ((p->p_flag & P_TRACED) == 0) 2600 continue; 2601 } 2602 2603 prop = sigprop(sig); 2604 2605 /* 2606 * Decide whether the signal should be returned. 2607 * Return the signal's number, or fall through 2608 * to clear it from the pending mask. 2609 */ 2610 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2611 2612 case (intptr_t)SIG_DFL: 2613 /* 2614 * Don't take default actions on system processes. 2615 */ 2616 if (p->p_pid <= 1) { 2617 #ifdef DIAGNOSTIC 2618 /* 2619 * Are you sure you want to ignore SIGSEGV 2620 * in init? XXX 2621 */ 2622 printf("Process (pid %lu) got signal %d\n", 2623 (u_long)p->p_pid, sig); 2624 #endif 2625 break; /* == ignore */ 2626 } 2627 /* 2628 * If there is a pending stop signal to process 2629 * with default action, stop here, 2630 * then clear the signal. However, 2631 * if process is member of an orphaned 2632 * process group, ignore tty stop signals. 2633 */ 2634 if (prop & SA_STOP) { 2635 if (p->p_flag & P_TRACED || 2636 (p->p_pgrp->pg_jobc == 0 && 2637 prop & SA_TTYSTOP)) 2638 break; /* == ignore */ 2639 mtx_unlock(&ps->ps_mtx); 2640 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2641 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2642 p->p_flag |= P_STOPPED_SIG; 2643 p->p_xstat = sig; 2644 PROC_SLOCK(p); 2645 sig_suspend_threads(td, p, 0); 2646 thread_suspend_switch(td); 2647 PROC_SUNLOCK(p); 2648 mtx_lock(&ps->ps_mtx); 2649 break; 2650 } else if (prop & SA_IGNORE) { 2651 /* 2652 * Except for SIGCONT, shouldn't get here. 2653 * Default action is to ignore; drop it. 2654 */ 2655 break; /* == ignore */ 2656 } else 2657 return (sig); 2658 /*NOTREACHED*/ 2659 2660 case (intptr_t)SIG_IGN: 2661 /* 2662 * Masking above should prevent us ever trying 2663 * to take action on an ignored signal other 2664 * than SIGCONT, unless process is traced. 2665 */ 2666 if ((prop & SA_CONT) == 0 && 2667 (p->p_flag & P_TRACED) == 0) 2668 printf("issignal\n"); 2669 break; /* == ignore */ 2670 2671 default: 2672 /* 2673 * This signal has an action, let 2674 * postsig() process it. 2675 */ 2676 return (sig); 2677 } 2678 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2679 } 2680 /* NOTREACHED */ 2681 } 2682 2683 void 2684 thread_stopped(struct proc *p) 2685 { 2686 int n; 2687 2688 PROC_LOCK_ASSERT(p, MA_OWNED); 2689 PROC_SLOCK_ASSERT(p, MA_OWNED); 2690 n = p->p_suspcount; 2691 if (p == curproc) 2692 n++; 2693 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2694 PROC_SUNLOCK(p); 2695 p->p_flag &= ~P_WAITED; 2696 PROC_LOCK(p->p_pptr); 2697 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2698 CLD_TRAPPED : CLD_STOPPED); 2699 PROC_UNLOCK(p->p_pptr); 2700 PROC_SLOCK(p); 2701 } 2702 } 2703 2704 /* 2705 * Take the action for the specified signal 2706 * from the current set of pending signals. 2707 */ 2708 void 2709 postsig(sig) 2710 register int sig; 2711 { 2712 struct thread *td = curthread; 2713 register struct proc *p = td->td_proc; 2714 struct sigacts *ps; 2715 sig_t action; 2716 ksiginfo_t ksi; 2717 sigset_t returnmask; 2718 int code; 2719 2720 KASSERT(sig != 0, ("postsig")); 2721 2722 PROC_LOCK_ASSERT(p, MA_OWNED); 2723 ps = p->p_sigacts; 2724 mtx_assert(&ps->ps_mtx, MA_OWNED); 2725 ksiginfo_init(&ksi); 2726 sigqueue_get(&td->td_sigqueue, sig, &ksi); 2727 ksi.ksi_signo = sig; 2728 if (ksi.ksi_code == SI_TIMER) 2729 itimer_accept(p, ksi.ksi_timerid, &ksi); 2730 action = ps->ps_sigact[_SIG_IDX(sig)]; 2731 #ifdef KTRACE 2732 if (KTRPOINT(td, KTR_PSIG)) 2733 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2734 &td->td_oldsigmask : &td->td_sigmask, 0); 2735 #endif 2736 if (p->p_stops & S_SIG) { 2737 mtx_unlock(&ps->ps_mtx); 2738 stopevent(p, S_SIG, sig); 2739 mtx_lock(&ps->ps_mtx); 2740 } 2741 2742 #ifdef KSE 2743 if (!(td->td_pflags & TDP_SA) && action == SIG_DFL) { 2744 #else 2745 if (action == SIG_DFL) { 2746 #endif 2747 /* 2748 * Default action, where the default is to kill 2749 * the process. (Other cases were ignored above.) 2750 */ 2751 mtx_unlock(&ps->ps_mtx); 2752 sigexit(td, sig); 2753 /* NOTREACHED */ 2754 } else { 2755 #ifdef KSE 2756 if (td->td_pflags & TDP_SA) { 2757 if (sig == SIGKILL) { 2758 mtx_unlock(&ps->ps_mtx); 2759 sigexit(td, sig); 2760 } 2761 } 2762 2763 #endif 2764 /* 2765 * If we get here, the signal must be caught. 2766 */ 2767 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2768 ("postsig action")); 2769 /* 2770 * Set the new mask value and also defer further 2771 * occurrences of this signal. 2772 * 2773 * Special case: user has done a sigsuspend. Here the 2774 * current mask is not of interest, but rather the 2775 * mask from before the sigsuspend is what we want 2776 * restored after the signal processing is completed. 2777 */ 2778 if (td->td_pflags & TDP_OLDMASK) { 2779 returnmask = td->td_oldsigmask; 2780 td->td_pflags &= ~TDP_OLDMASK; 2781 } else 2782 returnmask = td->td_sigmask; 2783 2784 SIGSETOR(td->td_sigmask, ps->ps_catchmask[_SIG_IDX(sig)]); 2785 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 2786 SIGADDSET(td->td_sigmask, sig); 2787 2788 if (SIGISMEMBER(ps->ps_sigreset, sig)) { 2789 /* 2790 * See kern_sigaction() for origin of this code. 2791 */ 2792 SIGDELSET(ps->ps_sigcatch, sig); 2793 if (sig != SIGCONT && 2794 sigprop(sig) & SA_IGNORE) 2795 SIGADDSET(ps->ps_sigignore, sig); 2796 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2797 } 2798 td->td_ru.ru_nsignals++; 2799 if (p->p_sig != sig) { 2800 code = 0; 2801 } else { 2802 code = p->p_code; 2803 p->p_code = 0; 2804 p->p_sig = 0; 2805 } 2806 #ifdef KSE 2807 if (td->td_pflags & TDP_SA) 2808 thread_signal_add(curthread, &ksi); 2809 else 2810 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2811 #else 2812 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2813 #endif 2814 } 2815 } 2816 2817 /* 2818 * Kill the current process for stated reason. 2819 */ 2820 void 2821 killproc(p, why) 2822 struct proc *p; 2823 char *why; 2824 { 2825 2826 PROC_LOCK_ASSERT(p, MA_OWNED); 2827 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", 2828 p, p->p_pid, p->p_comm); 2829 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, p->p_comm, 2830 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2831 psignal(p, SIGKILL); 2832 } 2833 2834 /* 2835 * Force the current process to exit with the specified signal, dumping core 2836 * if appropriate. We bypass the normal tests for masked and caught signals, 2837 * allowing unrecoverable failures to terminate the process without changing 2838 * signal state. Mark the accounting record with the signal termination. 2839 * If dumping core, save the signal number for the debugger. Calls exit and 2840 * does not return. 2841 */ 2842 void 2843 sigexit(td, sig) 2844 struct thread *td; 2845 int sig; 2846 { 2847 struct proc *p = td->td_proc; 2848 2849 PROC_LOCK_ASSERT(p, MA_OWNED); 2850 p->p_acflag |= AXSIG; 2851 /* 2852 * We must be single-threading to generate a core dump. This 2853 * ensures that the registers in the core file are up-to-date. 2854 * Also, the ELF dump handler assumes that the thread list doesn't 2855 * change out from under it. 2856 * 2857 * XXX If another thread attempts to single-thread before us 2858 * (e.g. via fork()), we won't get a dump at all. 2859 */ 2860 if ((sigprop(sig) & SA_CORE) && (thread_single(SINGLE_NO_EXIT) == 0)) { 2861 p->p_sig = sig; 2862 /* 2863 * Log signals which would cause core dumps 2864 * (Log as LOG_INFO to appease those who don't want 2865 * these messages.) 2866 * XXX : Todo, as well as euid, write out ruid too 2867 * Note that coredump() drops proc lock. 2868 */ 2869 if (coredump(td) == 0) 2870 sig |= WCOREFLAG; 2871 if (kern_logsigexit) 2872 log(LOG_INFO, 2873 "pid %d (%s), uid %d: exited on signal %d%s\n", 2874 p->p_pid, p->p_comm, 2875 td->td_ucred ? td->td_ucred->cr_uid : -1, 2876 sig &~ WCOREFLAG, 2877 sig & WCOREFLAG ? " (core dumped)" : ""); 2878 } else 2879 PROC_UNLOCK(p); 2880 exit1(td, W_EXITCODE(0, sig)); 2881 /* NOTREACHED */ 2882 } 2883 2884 /* 2885 * Send queued SIGCHLD to parent when child process's state 2886 * is changed. 2887 */ 2888 static void 2889 sigparent(struct proc *p, int reason, int status) 2890 { 2891 PROC_LOCK_ASSERT(p, MA_OWNED); 2892 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2893 2894 if (p->p_ksi != NULL) { 2895 p->p_ksi->ksi_signo = SIGCHLD; 2896 p->p_ksi->ksi_code = reason; 2897 p->p_ksi->ksi_status = status; 2898 p->p_ksi->ksi_pid = p->p_pid; 2899 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2900 if (KSI_ONQ(p->p_ksi)) 2901 return; 2902 } 2903 tdsignal(p->p_pptr, NULL, SIGCHLD, p->p_ksi); 2904 } 2905 2906 static void 2907 childproc_jobstate(struct proc *p, int reason, int status) 2908 { 2909 struct sigacts *ps; 2910 2911 PROC_LOCK_ASSERT(p, MA_OWNED); 2912 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2913 2914 /* 2915 * Wake up parent sleeping in kern_wait(), also send 2916 * SIGCHLD to parent, but SIGCHLD does not guarantee 2917 * that parent will awake, because parent may masked 2918 * the signal. 2919 */ 2920 p->p_pptr->p_flag |= P_STATCHILD; 2921 wakeup(p->p_pptr); 2922 2923 ps = p->p_pptr->p_sigacts; 2924 mtx_lock(&ps->ps_mtx); 2925 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 2926 mtx_unlock(&ps->ps_mtx); 2927 sigparent(p, reason, status); 2928 } else 2929 mtx_unlock(&ps->ps_mtx); 2930 } 2931 2932 void 2933 childproc_stopped(struct proc *p, int reason) 2934 { 2935 childproc_jobstate(p, reason, p->p_xstat); 2936 } 2937 2938 void 2939 childproc_continued(struct proc *p) 2940 { 2941 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 2942 } 2943 2944 void 2945 childproc_exited(struct proc *p) 2946 { 2947 int reason; 2948 int status = p->p_xstat; /* convert to int */ 2949 2950 reason = CLD_EXITED; 2951 if (WCOREDUMP(status)) 2952 reason = CLD_DUMPED; 2953 else if (WIFSIGNALED(status)) 2954 reason = CLD_KILLED; 2955 /* 2956 * XXX avoid calling wakeup(p->p_pptr), the work is 2957 * done in exit1(). 2958 */ 2959 sigparent(p, reason, status); 2960 } 2961 2962 static char corefilename[MAXPATHLEN] = {"%N.core"}; 2963 SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 2964 sizeof(corefilename), "process corefile name format string"); 2965 2966 /* 2967 * expand_name(name, uid, pid) 2968 * Expand the name described in corefilename, using name, uid, and pid. 2969 * corefilename is a printf-like string, with three format specifiers: 2970 * %N name of process ("name") 2971 * %P process id (pid) 2972 * %U user id (uid) 2973 * For example, "%N.core" is the default; they can be disabled completely 2974 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 2975 * This is controlled by the sysctl variable kern.corefile (see above). 2976 */ 2977 2978 static char * 2979 expand_name(name, uid, pid) 2980 const char *name; 2981 uid_t uid; 2982 pid_t pid; 2983 { 2984 const char *format, *appendstr; 2985 char *temp; 2986 char buf[11]; /* Buffer for pid/uid -- max 4B */ 2987 size_t i, l, n; 2988 2989 format = corefilename; 2990 temp = malloc(MAXPATHLEN, M_TEMP, M_NOWAIT | M_ZERO); 2991 if (temp == NULL) 2992 return (NULL); 2993 for (i = 0, n = 0; n < MAXPATHLEN && format[i]; i++) { 2994 switch (format[i]) { 2995 case '%': /* Format character */ 2996 i++; 2997 switch (format[i]) { 2998 case '%': 2999 appendstr = "%"; 3000 break; 3001 case 'N': /* process name */ 3002 appendstr = name; 3003 break; 3004 case 'P': /* process id */ 3005 sprintf(buf, "%u", pid); 3006 appendstr = buf; 3007 break; 3008 case 'U': /* user id */ 3009 sprintf(buf, "%u", uid); 3010 appendstr = buf; 3011 break; 3012 default: 3013 appendstr = ""; 3014 log(LOG_ERR, 3015 "Unknown format character %c in `%s'\n", 3016 format[i], format); 3017 } 3018 l = strlen(appendstr); 3019 if ((n + l) >= MAXPATHLEN) 3020 goto toolong; 3021 memcpy(temp + n, appendstr, l); 3022 n += l; 3023 break; 3024 default: 3025 temp[n++] = format[i]; 3026 } 3027 } 3028 if (format[i] != '\0') 3029 goto toolong; 3030 return (temp); 3031 toolong: 3032 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too long\n", 3033 (long)pid, name, (u_long)uid); 3034 free(temp, M_TEMP); 3035 return (NULL); 3036 } 3037 3038 /* 3039 * Dump a process' core. The main routine does some 3040 * policy checking, and creates the name of the coredump; 3041 * then it passes on a vnode and a size limit to the process-specific 3042 * coredump routine if there is one; if there _is not_ one, it returns 3043 * ENOSYS; otherwise it returns the error from the process-specific routine. 3044 */ 3045 3046 static int 3047 coredump(struct thread *td) 3048 { 3049 struct proc *p = td->td_proc; 3050 register struct vnode *vp; 3051 register struct ucred *cred = td->td_ucred; 3052 struct flock lf; 3053 struct nameidata nd; 3054 struct vattr vattr; 3055 int error, error1, flags, locked; 3056 struct mount *mp; 3057 char *name; /* name of corefile */ 3058 off_t limit; 3059 int vfslocked; 3060 3061 PROC_LOCK_ASSERT(p, MA_OWNED); 3062 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3063 _STOPEVENT(p, S_CORE, 0); 3064 3065 if (((sugid_coredump == 0) && p->p_flag & P_SUGID) || do_coredump == 0) { 3066 PROC_UNLOCK(p); 3067 return (EFAULT); 3068 } 3069 3070 /* 3071 * Note that the bulk of limit checking is done after 3072 * the corefile is created. The exception is if the limit 3073 * for corefiles is 0, in which case we don't bother 3074 * creating the corefile at all. This layout means that 3075 * a corefile is truncated instead of not being created, 3076 * if it is larger than the limit. 3077 */ 3078 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3079 PROC_UNLOCK(p); 3080 if (limit == 0) 3081 return (EFBIG); 3082 3083 restart: 3084 name = expand_name(p->p_comm, td->td_ucred->cr_uid, p->p_pid); 3085 if (name == NULL) 3086 return (EINVAL); 3087 NDINIT(&nd, LOOKUP, NOFOLLOW | MPSAFE, UIO_SYSSPACE, name, td); 3088 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3089 error = vn_open(&nd, &flags, S_IRUSR | S_IWUSR, NULL); 3090 free(name, M_TEMP); 3091 if (error) 3092 return (error); 3093 vfslocked = NDHASGIANT(&nd); 3094 NDFREE(&nd, NDF_ONLY_PNBUF); 3095 vp = nd.ni_vp; 3096 3097 /* Don't dump to non-regular files or files with links. */ 3098 if (vp->v_type != VREG || 3099 VOP_GETATTR(vp, &vattr, cred, td) || vattr.va_nlink != 1) { 3100 VOP_UNLOCK(vp, 0, td); 3101 error = EFAULT; 3102 goto close; 3103 } 3104 3105 VOP_UNLOCK(vp, 0, td); 3106 lf.l_whence = SEEK_SET; 3107 lf.l_start = 0; 3108 lf.l_len = 0; 3109 lf.l_type = F_WRLCK; 3110 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3111 3112 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3113 lf.l_type = F_UNLCK; 3114 if (locked) 3115 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3116 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3117 goto out; 3118 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3119 goto out; 3120 VFS_UNLOCK_GIANT(vfslocked); 3121 goto restart; 3122 } 3123 3124 VATTR_NULL(&vattr); 3125 vattr.va_size = 0; 3126 if (set_core_nodump_flag) 3127 vattr.va_flags = UF_NODUMP; 3128 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); 3129 VOP_LEASE(vp, td, cred, LEASE_WRITE); 3130 VOP_SETATTR(vp, &vattr, cred, td); 3131 VOP_UNLOCK(vp, 0, td); 3132 vn_finished_write(mp); 3133 PROC_LOCK(p); 3134 p->p_acflag |= ACORE; 3135 PROC_UNLOCK(p); 3136 3137 error = p->p_sysent->sv_coredump ? 3138 p->p_sysent->sv_coredump(td, vp, limit) : 3139 ENOSYS; 3140 3141 if (locked) { 3142 lf.l_type = F_UNLCK; 3143 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3144 } 3145 close: 3146 error1 = vn_close(vp, FWRITE, cred, td); 3147 if (error == 0) 3148 error = error1; 3149 out: 3150 VFS_UNLOCK_GIANT(vfslocked); 3151 return (error); 3152 } 3153 3154 /* 3155 * Nonexistent system call-- signal process (may want to handle it). Flag 3156 * error in case process won't see signal immediately (blocked or ignored). 3157 */ 3158 #ifndef _SYS_SYSPROTO_H_ 3159 struct nosys_args { 3160 int dummy; 3161 }; 3162 #endif 3163 /* ARGSUSED */ 3164 int 3165 nosys(td, args) 3166 struct thread *td; 3167 struct nosys_args *args; 3168 { 3169 struct proc *p = td->td_proc; 3170 3171 PROC_LOCK(p); 3172 psignal(p, SIGSYS); 3173 PROC_UNLOCK(p); 3174 return (ENOSYS); 3175 } 3176 3177 /* 3178 * Send a SIGIO or SIGURG signal to a process or process group using stored 3179 * credentials rather than those of the current process. 3180 */ 3181 void 3182 pgsigio(sigiop, sig, checkctty) 3183 struct sigio **sigiop; 3184 int sig, checkctty; 3185 { 3186 struct sigio *sigio; 3187 3188 SIGIO_LOCK(); 3189 sigio = *sigiop; 3190 if (sigio == NULL) { 3191 SIGIO_UNLOCK(); 3192 return; 3193 } 3194 if (sigio->sio_pgid > 0) { 3195 PROC_LOCK(sigio->sio_proc); 3196 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3197 psignal(sigio->sio_proc, sig); 3198 PROC_UNLOCK(sigio->sio_proc); 3199 } else if (sigio->sio_pgid < 0) { 3200 struct proc *p; 3201 3202 PGRP_LOCK(sigio->sio_pgrp); 3203 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3204 PROC_LOCK(p); 3205 if (CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3206 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3207 psignal(p, sig); 3208 PROC_UNLOCK(p); 3209 } 3210 PGRP_UNLOCK(sigio->sio_pgrp); 3211 } 3212 SIGIO_UNLOCK(); 3213 } 3214 3215 static int 3216 filt_sigattach(struct knote *kn) 3217 { 3218 struct proc *p = curproc; 3219 3220 kn->kn_ptr.p_proc = p; 3221 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3222 3223 knlist_add(&p->p_klist, kn, 0); 3224 3225 return (0); 3226 } 3227 3228 static void 3229 filt_sigdetach(struct knote *kn) 3230 { 3231 struct proc *p = kn->kn_ptr.p_proc; 3232 3233 knlist_remove(&p->p_klist, kn, 0); 3234 } 3235 3236 /* 3237 * signal knotes are shared with proc knotes, so we apply a mask to 3238 * the hint in order to differentiate them from process hints. This 3239 * could be avoided by using a signal-specific knote list, but probably 3240 * isn't worth the trouble. 3241 */ 3242 static int 3243 filt_signal(struct knote *kn, long hint) 3244 { 3245 3246 if (hint & NOTE_SIGNAL) { 3247 hint &= ~NOTE_SIGNAL; 3248 3249 if (kn->kn_id == hint) 3250 kn->kn_data++; 3251 } 3252 return (kn->kn_data != 0); 3253 } 3254 3255 struct sigacts * 3256 sigacts_alloc(void) 3257 { 3258 struct sigacts *ps; 3259 3260 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3261 ps->ps_refcnt = 1; 3262 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3263 return (ps); 3264 } 3265 3266 void 3267 sigacts_free(struct sigacts *ps) 3268 { 3269 3270 mtx_lock(&ps->ps_mtx); 3271 ps->ps_refcnt--; 3272 if (ps->ps_refcnt == 0) { 3273 mtx_destroy(&ps->ps_mtx); 3274 free(ps, M_SUBPROC); 3275 } else 3276 mtx_unlock(&ps->ps_mtx); 3277 } 3278 3279 struct sigacts * 3280 sigacts_hold(struct sigacts *ps) 3281 { 3282 mtx_lock(&ps->ps_mtx); 3283 ps->ps_refcnt++; 3284 mtx_unlock(&ps->ps_mtx); 3285 return (ps); 3286 } 3287 3288 void 3289 sigacts_copy(struct sigacts *dest, struct sigacts *src) 3290 { 3291 3292 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3293 mtx_lock(&src->ps_mtx); 3294 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3295 mtx_unlock(&src->ps_mtx); 3296 } 3297 3298 int 3299 sigacts_shared(struct sigacts *ps) 3300 { 3301 int shared; 3302 3303 mtx_lock(&ps->ps_mtx); 3304 shared = ps->ps_refcnt > 1; 3305 mtx_unlock(&ps->ps_mtx); 3306 return (shared); 3307 } 3308