kern_sig.c revision 276272
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: stable/10/sys/kern/kern_sig.c 276272 2014-12-27 00:55:14Z kib $"); 39 40#include "opt_compat.h" 41#include "opt_kdtrace.h" 42#include "opt_ktrace.h" 43#include "opt_core.h" 44#include "opt_procdesc.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/signalvar.h> 49#include <sys/vnode.h> 50#include <sys/acct.h> 51#include <sys/capability.h> 52#include <sys/condvar.h> 53#include <sys/event.h> 54#include <sys/fcntl.h> 55#include <sys/imgact.h> 56#include <sys/kernel.h> 57#include <sys/ktr.h> 58#include <sys/ktrace.h> 59#include <sys/lock.h> 60#include <sys/malloc.h> 61#include <sys/mutex.h> 62#include <sys/refcount.h> 63#include <sys/namei.h> 64#include <sys/proc.h> 65#include <sys/procdesc.h> 66#include <sys/posix4.h> 67#include <sys/pioctl.h> 68#include <sys/racct.h> 69#include <sys/resourcevar.h> 70#include <sys/sdt.h> 71#include <sys/sbuf.h> 72#include <sys/sleepqueue.h> 73#include <sys/smp.h> 74#include <sys/stat.h> 75#include <sys/sx.h> 76#include <sys/syscallsubr.h> 77#include <sys/sysctl.h> 78#include <sys/sysent.h> 79#include <sys/syslog.h> 80#include <sys/sysproto.h> 81#include <sys/timers.h> 82#include <sys/unistd.h> 83#include <sys/wait.h> 84#include <vm/vm.h> 85#include <vm/vm_extern.h> 86#include <vm/uma.h> 87 88#include <sys/jail.h> 89 90#include <machine/cpu.h> 91 92#include <security/audit/audit.h> 93 94#define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 95 96SDT_PROVIDER_DECLARE(proc); 97SDT_PROBE_DEFINE3(proc, kernel, , signal__send, "struct thread *", 98 "struct proc *", "int"); 99SDT_PROBE_DEFINE2(proc, kernel, , signal__clear, "int", 100 "ksiginfo_t *"); 101SDT_PROBE_DEFINE3(proc, kernel, , signal__discard, 102 "struct thread *", "struct proc *", "int"); 103 104static int coredump(struct thread *); 105static int killpg1(struct thread *td, int sig, int pgid, int all, 106 ksiginfo_t *ksi); 107static int issignal(struct thread *td); 108static int sigprop(int sig); 109static void tdsigwakeup(struct thread *, int, sig_t, int); 110static void sig_suspend_threads(struct thread *, struct proc *, int); 111static int filt_sigattach(struct knote *kn); 112static void filt_sigdetach(struct knote *kn); 113static int filt_signal(struct knote *kn, long hint); 114static struct thread *sigtd(struct proc *p, int sig, int prop); 115static void sigqueue_start(void); 116 117static uma_zone_t ksiginfo_zone = NULL; 118struct filterops sig_filtops = { 119 .f_isfd = 0, 120 .f_attach = filt_sigattach, 121 .f_detach = filt_sigdetach, 122 .f_event = filt_signal, 123}; 124 125static int kern_logsigexit = 1; 126SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 127 &kern_logsigexit, 0, 128 "Log processes quitting on abnormal signals to syslog(3)"); 129 130static int kern_forcesigexit = 1; 131SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 132 &kern_forcesigexit, 0, "Force trap signal to be handled"); 133 134static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 135 "POSIX real time signal"); 136 137static int max_pending_per_proc = 128; 138SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 139 &max_pending_per_proc, 0, "Max pending signals per proc"); 140 141static int preallocate_siginfo = 1024; 142TUNABLE_INT("kern.sigqueue.preallocate", &preallocate_siginfo); 143SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RD, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146static int signal_overflow = 0; 147SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150static int signal_alloc_fail = 0; 151SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 155 156/* 157 * Policy -- Can ucred cr1 send SIGIO to process cr2? 158 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 159 * in the right situations. 160 */ 161#define CANSIGIO(cr1, cr2) \ 162 ((cr1)->cr_uid == 0 || \ 163 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 164 (cr1)->cr_uid == (cr2)->cr_ruid || \ 165 (cr1)->cr_ruid == (cr2)->cr_uid || \ 166 (cr1)->cr_uid == (cr2)->cr_uid) 167 168static int sugid_coredump; 169TUNABLE_INT("kern.sugid_coredump", &sugid_coredump); 170SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RW, 171 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 172 173static int capmode_coredump; 174TUNABLE_INT("kern.capmode_coredump", &capmode_coredump); 175SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RW, 176 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 177 178static int do_coredump = 1; 179SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 180 &do_coredump, 0, "Enable/Disable coredumps"); 181 182static int set_core_nodump_flag = 0; 183SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 184 0, "Enable setting the NODUMP flag on coredump files"); 185 186/* 187 * Signal properties and actions. 188 * The array below categorizes the signals and their default actions 189 * according to the following properties: 190 */ 191#define SA_KILL 0x01 /* terminates process by default */ 192#define SA_CORE 0x02 /* ditto and coredumps */ 193#define SA_STOP 0x04 /* suspend process */ 194#define SA_TTYSTOP 0x08 /* ditto, from tty */ 195#define SA_IGNORE 0x10 /* ignore by default */ 196#define SA_CONT 0x20 /* continue if suspended */ 197#define SA_CANTMASK 0x40 /* non-maskable, catchable */ 198 199static int sigproptbl[NSIG] = { 200 SA_KILL, /* SIGHUP */ 201 SA_KILL, /* SIGINT */ 202 SA_KILL|SA_CORE, /* SIGQUIT */ 203 SA_KILL|SA_CORE, /* SIGILL */ 204 SA_KILL|SA_CORE, /* SIGTRAP */ 205 SA_KILL|SA_CORE, /* SIGABRT */ 206 SA_KILL|SA_CORE, /* SIGEMT */ 207 SA_KILL|SA_CORE, /* SIGFPE */ 208 SA_KILL, /* SIGKILL */ 209 SA_KILL|SA_CORE, /* SIGBUS */ 210 SA_KILL|SA_CORE, /* SIGSEGV */ 211 SA_KILL|SA_CORE, /* SIGSYS */ 212 SA_KILL, /* SIGPIPE */ 213 SA_KILL, /* SIGALRM */ 214 SA_KILL, /* SIGTERM */ 215 SA_IGNORE, /* SIGURG */ 216 SA_STOP, /* SIGSTOP */ 217 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 218 SA_IGNORE|SA_CONT, /* SIGCONT */ 219 SA_IGNORE, /* SIGCHLD */ 220 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 221 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 222 SA_IGNORE, /* SIGIO */ 223 SA_KILL, /* SIGXCPU */ 224 SA_KILL, /* SIGXFSZ */ 225 SA_KILL, /* SIGVTALRM */ 226 SA_KILL, /* SIGPROF */ 227 SA_IGNORE, /* SIGWINCH */ 228 SA_IGNORE, /* SIGINFO */ 229 SA_KILL, /* SIGUSR1 */ 230 SA_KILL, /* SIGUSR2 */ 231}; 232 233static void reschedule_signals(struct proc *p, sigset_t block, int flags); 234 235static void 236sigqueue_start(void) 237{ 238 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 239 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 240 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 241 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 242 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 243 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 244} 245 246ksiginfo_t * 247ksiginfo_alloc(int wait) 248{ 249 int flags; 250 251 flags = M_ZERO; 252 if (! wait) 253 flags |= M_NOWAIT; 254 if (ksiginfo_zone != NULL) 255 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 256 return (NULL); 257} 258 259void 260ksiginfo_free(ksiginfo_t *ksi) 261{ 262 uma_zfree(ksiginfo_zone, ksi); 263} 264 265static __inline int 266ksiginfo_tryfree(ksiginfo_t *ksi) 267{ 268 if (!(ksi->ksi_flags & KSI_EXT)) { 269 uma_zfree(ksiginfo_zone, ksi); 270 return (1); 271 } 272 return (0); 273} 274 275void 276sigqueue_init(sigqueue_t *list, struct proc *p) 277{ 278 SIGEMPTYSET(list->sq_signals); 279 SIGEMPTYSET(list->sq_kill); 280 TAILQ_INIT(&list->sq_list); 281 list->sq_proc = p; 282 list->sq_flags = SQ_INIT; 283} 284 285/* 286 * Get a signal's ksiginfo. 287 * Return: 288 * 0 - signal not found 289 * others - signal number 290 */ 291static int 292sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 293{ 294 struct proc *p = sq->sq_proc; 295 struct ksiginfo *ksi, *next; 296 int count = 0; 297 298 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 299 300 if (!SIGISMEMBER(sq->sq_signals, signo)) 301 return (0); 302 303 if (SIGISMEMBER(sq->sq_kill, signo)) { 304 count++; 305 SIGDELSET(sq->sq_kill, signo); 306 } 307 308 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 309 if (ksi->ksi_signo == signo) { 310 if (count == 0) { 311 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 312 ksi->ksi_sigq = NULL; 313 ksiginfo_copy(ksi, si); 314 if (ksiginfo_tryfree(ksi) && p != NULL) 315 p->p_pendingcnt--; 316 } 317 if (++count > 1) 318 break; 319 } 320 } 321 322 if (count <= 1) 323 SIGDELSET(sq->sq_signals, signo); 324 si->ksi_signo = signo; 325 return (signo); 326} 327 328void 329sigqueue_take(ksiginfo_t *ksi) 330{ 331 struct ksiginfo *kp; 332 struct proc *p; 333 sigqueue_t *sq; 334 335 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 336 return; 337 338 p = sq->sq_proc; 339 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 340 ksi->ksi_sigq = NULL; 341 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 342 p->p_pendingcnt--; 343 344 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 345 kp = TAILQ_NEXT(kp, ksi_link)) { 346 if (kp->ksi_signo == ksi->ksi_signo) 347 break; 348 } 349 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo)) 350 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 351} 352 353static int 354sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 355{ 356 struct proc *p = sq->sq_proc; 357 struct ksiginfo *ksi; 358 int ret = 0; 359 360 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 361 362 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 363 SIGADDSET(sq->sq_kill, signo); 364 goto out_set_bit; 365 } 366 367 /* directly insert the ksi, don't copy it */ 368 if (si->ksi_flags & KSI_INS) { 369 if (si->ksi_flags & KSI_HEAD) 370 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 371 else 372 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 373 si->ksi_sigq = sq; 374 goto out_set_bit; 375 } 376 377 if (__predict_false(ksiginfo_zone == NULL)) { 378 SIGADDSET(sq->sq_kill, signo); 379 goto out_set_bit; 380 } 381 382 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 383 signal_overflow++; 384 ret = EAGAIN; 385 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 386 signal_alloc_fail++; 387 ret = EAGAIN; 388 } else { 389 if (p != NULL) 390 p->p_pendingcnt++; 391 ksiginfo_copy(si, ksi); 392 ksi->ksi_signo = signo; 393 if (si->ksi_flags & KSI_HEAD) 394 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 395 else 396 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 397 ksi->ksi_sigq = sq; 398 } 399 400 if ((si->ksi_flags & KSI_TRAP) != 0 || 401 (si->ksi_flags & KSI_SIGQ) == 0) { 402 if (ret != 0) 403 SIGADDSET(sq->sq_kill, signo); 404 ret = 0; 405 goto out_set_bit; 406 } 407 408 if (ret != 0) 409 return (ret); 410 411out_set_bit: 412 SIGADDSET(sq->sq_signals, signo); 413 return (ret); 414} 415 416void 417sigqueue_flush(sigqueue_t *sq) 418{ 419 struct proc *p = sq->sq_proc; 420 ksiginfo_t *ksi; 421 422 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 423 424 if (p != NULL) 425 PROC_LOCK_ASSERT(p, MA_OWNED); 426 427 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 428 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 429 ksi->ksi_sigq = NULL; 430 if (ksiginfo_tryfree(ksi) && p != NULL) 431 p->p_pendingcnt--; 432 } 433 434 SIGEMPTYSET(sq->sq_signals); 435 SIGEMPTYSET(sq->sq_kill); 436} 437 438static void 439sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 440{ 441 sigset_t tmp; 442 struct proc *p1, *p2; 443 ksiginfo_t *ksi, *next; 444 445 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 446 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 447 p1 = src->sq_proc; 448 p2 = dst->sq_proc; 449 /* Move siginfo to target list */ 450 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 451 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 452 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 453 if (p1 != NULL) 454 p1->p_pendingcnt--; 455 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 456 ksi->ksi_sigq = dst; 457 if (p2 != NULL) 458 p2->p_pendingcnt++; 459 } 460 } 461 462 /* Move pending bits to target list */ 463 tmp = src->sq_kill; 464 SIGSETAND(tmp, *set); 465 SIGSETOR(dst->sq_kill, tmp); 466 SIGSETNAND(src->sq_kill, tmp); 467 468 tmp = src->sq_signals; 469 SIGSETAND(tmp, *set); 470 SIGSETOR(dst->sq_signals, tmp); 471 SIGSETNAND(src->sq_signals, tmp); 472} 473 474#if 0 475static void 476sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 477{ 478 sigset_t set; 479 480 SIGEMPTYSET(set); 481 SIGADDSET(set, signo); 482 sigqueue_move_set(src, dst, &set); 483} 484#endif 485 486static void 487sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 488{ 489 struct proc *p = sq->sq_proc; 490 ksiginfo_t *ksi, *next; 491 492 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 493 494 /* Remove siginfo queue */ 495 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 496 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 497 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 498 ksi->ksi_sigq = NULL; 499 if (ksiginfo_tryfree(ksi) && p != NULL) 500 p->p_pendingcnt--; 501 } 502 } 503 SIGSETNAND(sq->sq_kill, *set); 504 SIGSETNAND(sq->sq_signals, *set); 505} 506 507void 508sigqueue_delete(sigqueue_t *sq, int signo) 509{ 510 sigset_t set; 511 512 SIGEMPTYSET(set); 513 SIGADDSET(set, signo); 514 sigqueue_delete_set(sq, &set); 515} 516 517/* Remove a set of signals for a process */ 518static void 519sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 520{ 521 sigqueue_t worklist; 522 struct thread *td0; 523 524 PROC_LOCK_ASSERT(p, MA_OWNED); 525 526 sigqueue_init(&worklist, NULL); 527 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 528 529 FOREACH_THREAD_IN_PROC(p, td0) 530 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 531 532 sigqueue_flush(&worklist); 533} 534 535void 536sigqueue_delete_proc(struct proc *p, int signo) 537{ 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set_proc(p, &set); 543} 544 545static void 546sigqueue_delete_stopmask_proc(struct proc *p) 547{ 548 sigset_t set; 549 550 SIGEMPTYSET(set); 551 SIGADDSET(set, SIGSTOP); 552 SIGADDSET(set, SIGTSTP); 553 SIGADDSET(set, SIGTTIN); 554 SIGADDSET(set, SIGTTOU); 555 sigqueue_delete_set_proc(p, &set); 556} 557 558/* 559 * Determine signal that should be delivered to thread td, the current 560 * thread, 0 if none. If there is a pending stop signal with default 561 * action, the process stops in issignal(). 562 */ 563int 564cursig(struct thread *td) 565{ 566 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 567 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 568 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 569 return (SIGPENDING(td) ? issignal(td) : 0); 570} 571 572/* 573 * Arrange for ast() to handle unmasked pending signals on return to user 574 * mode. This must be called whenever a signal is added to td_sigqueue or 575 * unmasked in td_sigmask. 576 */ 577void 578signotify(struct thread *td) 579{ 580 struct proc *p; 581 582 p = td->td_proc; 583 584 PROC_LOCK_ASSERT(p, MA_OWNED); 585 586 if (SIGPENDING(td)) { 587 thread_lock(td); 588 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 589 thread_unlock(td); 590 } 591} 592 593int 594sigonstack(size_t sp) 595{ 596 struct thread *td = curthread; 597 598 return ((td->td_pflags & TDP_ALTSTACK) ? 599#if defined(COMPAT_43) 600 ((td->td_sigstk.ss_size == 0) ? 601 (td->td_sigstk.ss_flags & SS_ONSTACK) : 602 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 603#else 604 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 605#endif 606 : 0); 607} 608 609static __inline int 610sigprop(int sig) 611{ 612 613 if (sig > 0 && sig < NSIG) 614 return (sigproptbl[_SIG_IDX(sig)]); 615 return (0); 616} 617 618int 619sig_ffs(sigset_t *set) 620{ 621 int i; 622 623 for (i = 0; i < _SIG_WORDS; i++) 624 if (set->__bits[i]) 625 return (ffs(set->__bits[i]) + (i * 32)); 626 return (0); 627} 628 629static bool 630sigact_flag_test(struct sigaction *act, int flag) 631{ 632 633 /* 634 * SA_SIGINFO is reset when signal disposition is set to 635 * ignore or default. Other flags are kept according to user 636 * settings. 637 */ 638 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 639 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 640 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 641} 642 643/* 644 * kern_sigaction 645 * sigaction 646 * freebsd4_sigaction 647 * osigaction 648 */ 649int 650kern_sigaction(td, sig, act, oact, flags) 651 struct thread *td; 652 register int sig; 653 struct sigaction *act, *oact; 654 int flags; 655{ 656 struct sigacts *ps; 657 struct proc *p = td->td_proc; 658 659 if (!_SIG_VALID(sig)) 660 return (EINVAL); 661 if (act != NULL && (act->sa_flags & ~(SA_ONSTACK | SA_RESTART | 662 SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | SA_NOCLDWAIT | 663 SA_SIGINFO)) != 0) 664 return (EINVAL); 665 666 PROC_LOCK(p); 667 ps = p->p_sigacts; 668 mtx_lock(&ps->ps_mtx); 669 if (oact) { 670 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 671 oact->sa_flags = 0; 672 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 673 oact->sa_flags |= SA_ONSTACK; 674 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 675 oact->sa_flags |= SA_RESTART; 676 if (SIGISMEMBER(ps->ps_sigreset, sig)) 677 oact->sa_flags |= SA_RESETHAND; 678 if (SIGISMEMBER(ps->ps_signodefer, sig)) 679 oact->sa_flags |= SA_NODEFER; 680 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 681 oact->sa_flags |= SA_SIGINFO; 682 oact->sa_sigaction = 683 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 684 } else 685 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 686 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 687 oact->sa_flags |= SA_NOCLDSTOP; 688 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 689 oact->sa_flags |= SA_NOCLDWAIT; 690 } 691 if (act) { 692 if ((sig == SIGKILL || sig == SIGSTOP) && 693 act->sa_handler != SIG_DFL) { 694 mtx_unlock(&ps->ps_mtx); 695 PROC_UNLOCK(p); 696 return (EINVAL); 697 } 698 699 /* 700 * Change setting atomically. 701 */ 702 703 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 704 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 705 if (sigact_flag_test(act, SA_SIGINFO)) { 706 ps->ps_sigact[_SIG_IDX(sig)] = 707 (__sighandler_t *)act->sa_sigaction; 708 SIGADDSET(ps->ps_siginfo, sig); 709 } else { 710 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 711 SIGDELSET(ps->ps_siginfo, sig); 712 } 713 if (!sigact_flag_test(act, SA_RESTART)) 714 SIGADDSET(ps->ps_sigintr, sig); 715 else 716 SIGDELSET(ps->ps_sigintr, sig); 717 if (sigact_flag_test(act, SA_ONSTACK)) 718 SIGADDSET(ps->ps_sigonstack, sig); 719 else 720 SIGDELSET(ps->ps_sigonstack, sig); 721 if (sigact_flag_test(act, SA_RESETHAND)) 722 SIGADDSET(ps->ps_sigreset, sig); 723 else 724 SIGDELSET(ps->ps_sigreset, sig); 725 if (sigact_flag_test(act, SA_NODEFER)) 726 SIGADDSET(ps->ps_signodefer, sig); 727 else 728 SIGDELSET(ps->ps_signodefer, sig); 729 if (sig == SIGCHLD) { 730 if (act->sa_flags & SA_NOCLDSTOP) 731 ps->ps_flag |= PS_NOCLDSTOP; 732 else 733 ps->ps_flag &= ~PS_NOCLDSTOP; 734 if (act->sa_flags & SA_NOCLDWAIT) { 735 /* 736 * Paranoia: since SA_NOCLDWAIT is implemented 737 * by reparenting the dying child to PID 1 (and 738 * trust it to reap the zombie), PID 1 itself 739 * is forbidden to set SA_NOCLDWAIT. 740 */ 741 if (p->p_pid == 1) 742 ps->ps_flag &= ~PS_NOCLDWAIT; 743 else 744 ps->ps_flag |= PS_NOCLDWAIT; 745 } else 746 ps->ps_flag &= ~PS_NOCLDWAIT; 747 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 748 ps->ps_flag |= PS_CLDSIGIGN; 749 else 750 ps->ps_flag &= ~PS_CLDSIGIGN; 751 } 752 /* 753 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 754 * and for signals set to SIG_DFL where the default is to 755 * ignore. However, don't put SIGCONT in ps_sigignore, as we 756 * have to restart the process. 757 */ 758 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 759 (sigprop(sig) & SA_IGNORE && 760 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 761 /* never to be seen again */ 762 sigqueue_delete_proc(p, sig); 763 if (sig != SIGCONT) 764 /* easier in psignal */ 765 SIGADDSET(ps->ps_sigignore, sig); 766 SIGDELSET(ps->ps_sigcatch, sig); 767 } else { 768 SIGDELSET(ps->ps_sigignore, sig); 769 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 770 SIGDELSET(ps->ps_sigcatch, sig); 771 else 772 SIGADDSET(ps->ps_sigcatch, sig); 773 } 774#ifdef COMPAT_FREEBSD4 775 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 776 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 777 (flags & KSA_FREEBSD4) == 0) 778 SIGDELSET(ps->ps_freebsd4, sig); 779 else 780 SIGADDSET(ps->ps_freebsd4, sig); 781#endif 782#ifdef COMPAT_43 783 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 784 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 785 (flags & KSA_OSIGSET) == 0) 786 SIGDELSET(ps->ps_osigset, sig); 787 else 788 SIGADDSET(ps->ps_osigset, sig); 789#endif 790 } 791 mtx_unlock(&ps->ps_mtx); 792 PROC_UNLOCK(p); 793 return (0); 794} 795 796#ifndef _SYS_SYSPROTO_H_ 797struct sigaction_args { 798 int sig; 799 struct sigaction *act; 800 struct sigaction *oact; 801}; 802#endif 803int 804sys_sigaction(td, uap) 805 struct thread *td; 806 register struct sigaction_args *uap; 807{ 808 struct sigaction act, oact; 809 register struct sigaction *actp, *oactp; 810 int error; 811 812 actp = (uap->act != NULL) ? &act : NULL; 813 oactp = (uap->oact != NULL) ? &oact : NULL; 814 if (actp) { 815 error = copyin(uap->act, actp, sizeof(act)); 816 if (error) 817 return (error); 818 } 819 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 820 if (oactp && !error) 821 error = copyout(oactp, uap->oact, sizeof(oact)); 822 return (error); 823} 824 825#ifdef COMPAT_FREEBSD4 826#ifndef _SYS_SYSPROTO_H_ 827struct freebsd4_sigaction_args { 828 int sig; 829 struct sigaction *act; 830 struct sigaction *oact; 831}; 832#endif 833int 834freebsd4_sigaction(td, uap) 835 struct thread *td; 836 register struct freebsd4_sigaction_args *uap; 837{ 838 struct sigaction act, oact; 839 register struct sigaction *actp, *oactp; 840 int error; 841 842 843 actp = (uap->act != NULL) ? &act : NULL; 844 oactp = (uap->oact != NULL) ? &oact : NULL; 845 if (actp) { 846 error = copyin(uap->act, actp, sizeof(act)); 847 if (error) 848 return (error); 849 } 850 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 851 if (oactp && !error) 852 error = copyout(oactp, uap->oact, sizeof(oact)); 853 return (error); 854} 855#endif /* COMAPT_FREEBSD4 */ 856 857#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 858#ifndef _SYS_SYSPROTO_H_ 859struct osigaction_args { 860 int signum; 861 struct osigaction *nsa; 862 struct osigaction *osa; 863}; 864#endif 865int 866osigaction(td, uap) 867 struct thread *td; 868 register struct osigaction_args *uap; 869{ 870 struct osigaction sa; 871 struct sigaction nsa, osa; 872 register struct sigaction *nsap, *osap; 873 int error; 874 875 if (uap->signum <= 0 || uap->signum >= ONSIG) 876 return (EINVAL); 877 878 nsap = (uap->nsa != NULL) ? &nsa : NULL; 879 osap = (uap->osa != NULL) ? &osa : NULL; 880 881 if (nsap) { 882 error = copyin(uap->nsa, &sa, sizeof(sa)); 883 if (error) 884 return (error); 885 nsap->sa_handler = sa.sa_handler; 886 nsap->sa_flags = sa.sa_flags; 887 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 888 } 889 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 890 if (osap && !error) { 891 sa.sa_handler = osap->sa_handler; 892 sa.sa_flags = osap->sa_flags; 893 SIG2OSIG(osap->sa_mask, sa.sa_mask); 894 error = copyout(&sa, uap->osa, sizeof(sa)); 895 } 896 return (error); 897} 898 899#if !defined(__i386__) 900/* Avoid replicating the same stub everywhere */ 901int 902osigreturn(td, uap) 903 struct thread *td; 904 struct osigreturn_args *uap; 905{ 906 907 return (nosys(td, (struct nosys_args *)uap)); 908} 909#endif 910#endif /* COMPAT_43 */ 911 912/* 913 * Initialize signal state for process 0; 914 * set to ignore signals that are ignored by default. 915 */ 916void 917siginit(p) 918 struct proc *p; 919{ 920 register int i; 921 struct sigacts *ps; 922 923 PROC_LOCK(p); 924 ps = p->p_sigacts; 925 mtx_lock(&ps->ps_mtx); 926 for (i = 1; i <= NSIG; i++) { 927 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 928 SIGADDSET(ps->ps_sigignore, i); 929 } 930 } 931 mtx_unlock(&ps->ps_mtx); 932 PROC_UNLOCK(p); 933} 934 935/* 936 * Reset specified signal to the default disposition. 937 */ 938static void 939sigdflt(struct sigacts *ps, int sig) 940{ 941 942 mtx_assert(&ps->ps_mtx, MA_OWNED); 943 SIGDELSET(ps->ps_sigcatch, sig); 944 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 945 SIGADDSET(ps->ps_sigignore, sig); 946 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 947 SIGDELSET(ps->ps_siginfo, sig); 948} 949 950/* 951 * Reset signals for an exec of the specified process. 952 */ 953void 954execsigs(struct proc *p) 955{ 956 struct sigacts *ps; 957 int sig; 958 struct thread *td; 959 960 /* 961 * Reset caught signals. Held signals remain held 962 * through td_sigmask (unless they were caught, 963 * and are now ignored by default). 964 */ 965 PROC_LOCK_ASSERT(p, MA_OWNED); 966 td = FIRST_THREAD_IN_PROC(p); 967 ps = p->p_sigacts; 968 mtx_lock(&ps->ps_mtx); 969 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 970 sig = sig_ffs(&ps->ps_sigcatch); 971 sigdflt(ps, sig); 972 if ((sigprop(sig) & SA_IGNORE) != 0) 973 sigqueue_delete_proc(p, sig); 974 } 975 /* 976 * Reset stack state to the user stack. 977 * Clear set of signals caught on the signal stack. 978 */ 979 td->td_sigstk.ss_flags = SS_DISABLE; 980 td->td_sigstk.ss_size = 0; 981 td->td_sigstk.ss_sp = 0; 982 td->td_pflags &= ~TDP_ALTSTACK; 983 /* 984 * Reset no zombies if child dies flag as Solaris does. 985 */ 986 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 987 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 988 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 989 mtx_unlock(&ps->ps_mtx); 990} 991 992/* 993 * kern_sigprocmask() 994 * 995 * Manipulate signal mask. 996 */ 997int 998kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 999 int flags) 1000{ 1001 sigset_t new_block, oset1; 1002 struct proc *p; 1003 int error; 1004 1005 p = td->td_proc; 1006 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1007 PROC_LOCK_ASSERT(p, MA_OWNED); 1008 else 1009 PROC_LOCK(p); 1010 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1011 ? MA_OWNED : MA_NOTOWNED); 1012 if (oset != NULL) 1013 *oset = td->td_sigmask; 1014 1015 error = 0; 1016 if (set != NULL) { 1017 switch (how) { 1018 case SIG_BLOCK: 1019 SIG_CANTMASK(*set); 1020 oset1 = td->td_sigmask; 1021 SIGSETOR(td->td_sigmask, *set); 1022 new_block = td->td_sigmask; 1023 SIGSETNAND(new_block, oset1); 1024 break; 1025 case SIG_UNBLOCK: 1026 SIGSETNAND(td->td_sigmask, *set); 1027 signotify(td); 1028 goto out; 1029 case SIG_SETMASK: 1030 SIG_CANTMASK(*set); 1031 oset1 = td->td_sigmask; 1032 if (flags & SIGPROCMASK_OLD) 1033 SIGSETLO(td->td_sigmask, *set); 1034 else 1035 td->td_sigmask = *set; 1036 new_block = td->td_sigmask; 1037 SIGSETNAND(new_block, oset1); 1038 signotify(td); 1039 break; 1040 default: 1041 error = EINVAL; 1042 goto out; 1043 } 1044 1045 /* 1046 * The new_block set contains signals that were not previously 1047 * blocked, but are blocked now. 1048 * 1049 * In case we block any signal that was not previously blocked 1050 * for td, and process has the signal pending, try to schedule 1051 * signal delivery to some thread that does not block the 1052 * signal, possibly waking it up. 1053 */ 1054 if (p->p_numthreads != 1) 1055 reschedule_signals(p, new_block, flags); 1056 } 1057 1058out: 1059 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1060 PROC_UNLOCK(p); 1061 return (error); 1062} 1063 1064#ifndef _SYS_SYSPROTO_H_ 1065struct sigprocmask_args { 1066 int how; 1067 const sigset_t *set; 1068 sigset_t *oset; 1069}; 1070#endif 1071int 1072sys_sigprocmask(td, uap) 1073 register struct thread *td; 1074 struct sigprocmask_args *uap; 1075{ 1076 sigset_t set, oset; 1077 sigset_t *setp, *osetp; 1078 int error; 1079 1080 setp = (uap->set != NULL) ? &set : NULL; 1081 osetp = (uap->oset != NULL) ? &oset : NULL; 1082 if (setp) { 1083 error = copyin(uap->set, setp, sizeof(set)); 1084 if (error) 1085 return (error); 1086 } 1087 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1088 if (osetp && !error) { 1089 error = copyout(osetp, uap->oset, sizeof(oset)); 1090 } 1091 return (error); 1092} 1093 1094#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1095#ifndef _SYS_SYSPROTO_H_ 1096struct osigprocmask_args { 1097 int how; 1098 osigset_t mask; 1099}; 1100#endif 1101int 1102osigprocmask(td, uap) 1103 register struct thread *td; 1104 struct osigprocmask_args *uap; 1105{ 1106 sigset_t set, oset; 1107 int error; 1108 1109 OSIG2SIG(uap->mask, set); 1110 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1111 SIG2OSIG(oset, td->td_retval[0]); 1112 return (error); 1113} 1114#endif /* COMPAT_43 */ 1115 1116int 1117sys_sigwait(struct thread *td, struct sigwait_args *uap) 1118{ 1119 ksiginfo_t ksi; 1120 sigset_t set; 1121 int error; 1122 1123 error = copyin(uap->set, &set, sizeof(set)); 1124 if (error) { 1125 td->td_retval[0] = error; 1126 return (0); 1127 } 1128 1129 error = kern_sigtimedwait(td, set, &ksi, NULL); 1130 if (error) { 1131 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1132 error = ERESTART; 1133 if (error == ERESTART) 1134 return (error); 1135 td->td_retval[0] = error; 1136 return (0); 1137 } 1138 1139 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1140 td->td_retval[0] = error; 1141 return (0); 1142} 1143 1144int 1145sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1146{ 1147 struct timespec ts; 1148 struct timespec *timeout; 1149 sigset_t set; 1150 ksiginfo_t ksi; 1151 int error; 1152 1153 if (uap->timeout) { 1154 error = copyin(uap->timeout, &ts, sizeof(ts)); 1155 if (error) 1156 return (error); 1157 1158 timeout = &ts; 1159 } else 1160 timeout = NULL; 1161 1162 error = copyin(uap->set, &set, sizeof(set)); 1163 if (error) 1164 return (error); 1165 1166 error = kern_sigtimedwait(td, set, &ksi, timeout); 1167 if (error) 1168 return (error); 1169 1170 if (uap->info) 1171 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1172 1173 if (error == 0) 1174 td->td_retval[0] = ksi.ksi_signo; 1175 return (error); 1176} 1177 1178int 1179sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1180{ 1181 ksiginfo_t ksi; 1182 sigset_t set; 1183 int error; 1184 1185 error = copyin(uap->set, &set, sizeof(set)); 1186 if (error) 1187 return (error); 1188 1189 error = kern_sigtimedwait(td, set, &ksi, NULL); 1190 if (error) 1191 return (error); 1192 1193 if (uap->info) 1194 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1195 1196 if (error == 0) 1197 td->td_retval[0] = ksi.ksi_signo; 1198 return (error); 1199} 1200 1201int 1202kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1203 struct timespec *timeout) 1204{ 1205 struct sigacts *ps; 1206 sigset_t saved_mask, new_block; 1207 struct proc *p; 1208 int error, sig, timo, timevalid = 0; 1209 struct timespec rts, ets, ts; 1210 struct timeval tv; 1211 1212 p = td->td_proc; 1213 error = 0; 1214 ets.tv_sec = 0; 1215 ets.tv_nsec = 0; 1216 1217 if (timeout != NULL) { 1218 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1219 timevalid = 1; 1220 getnanouptime(&rts); 1221 ets = rts; 1222 timespecadd(&ets, timeout); 1223 } 1224 } 1225 ksiginfo_init(ksi); 1226 /* Some signals can not be waited for. */ 1227 SIG_CANTMASK(waitset); 1228 ps = p->p_sigacts; 1229 PROC_LOCK(p); 1230 saved_mask = td->td_sigmask; 1231 SIGSETNAND(td->td_sigmask, waitset); 1232 for (;;) { 1233 mtx_lock(&ps->ps_mtx); 1234 sig = cursig(td); 1235 mtx_unlock(&ps->ps_mtx); 1236 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1237 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1238 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1239 error = 0; 1240 break; 1241 } 1242 } 1243 1244 if (error != 0) 1245 break; 1246 1247 /* 1248 * POSIX says this must be checked after looking for pending 1249 * signals. 1250 */ 1251 if (timeout != NULL) { 1252 if (!timevalid) { 1253 error = EINVAL; 1254 break; 1255 } 1256 getnanouptime(&rts); 1257 if (timespeccmp(&rts, &ets, >=)) { 1258 error = EAGAIN; 1259 break; 1260 } 1261 ts = ets; 1262 timespecsub(&ts, &rts); 1263 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1264 timo = tvtohz(&tv); 1265 } else { 1266 timo = 0; 1267 } 1268 1269 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1270 1271 if (timeout != NULL) { 1272 if (error == ERESTART) { 1273 /* Timeout can not be restarted. */ 1274 error = EINTR; 1275 } else if (error == EAGAIN) { 1276 /* We will calculate timeout by ourself. */ 1277 error = 0; 1278 } 1279 } 1280 } 1281 1282 new_block = saved_mask; 1283 SIGSETNAND(new_block, td->td_sigmask); 1284 td->td_sigmask = saved_mask; 1285 /* 1286 * Fewer signals can be delivered to us, reschedule signal 1287 * notification. 1288 */ 1289 if (p->p_numthreads != 1) 1290 reschedule_signals(p, new_block, 0); 1291 1292 if (error == 0) { 1293 SDT_PROBE(proc, kernel, , signal__clear, sig, ksi, 0, 0, 0); 1294 1295 if (ksi->ksi_code == SI_TIMER) 1296 itimer_accept(p, ksi->ksi_timerid, ksi); 1297 1298#ifdef KTRACE 1299 if (KTRPOINT(td, KTR_PSIG)) { 1300 sig_t action; 1301 1302 mtx_lock(&ps->ps_mtx); 1303 action = ps->ps_sigact[_SIG_IDX(sig)]; 1304 mtx_unlock(&ps->ps_mtx); 1305 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1306 } 1307#endif 1308 if (sig == SIGKILL) 1309 sigexit(td, sig); 1310 } 1311 PROC_UNLOCK(p); 1312 return (error); 1313} 1314 1315#ifndef _SYS_SYSPROTO_H_ 1316struct sigpending_args { 1317 sigset_t *set; 1318}; 1319#endif 1320int 1321sys_sigpending(td, uap) 1322 struct thread *td; 1323 struct sigpending_args *uap; 1324{ 1325 struct proc *p = td->td_proc; 1326 sigset_t pending; 1327 1328 PROC_LOCK(p); 1329 pending = p->p_sigqueue.sq_signals; 1330 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1331 PROC_UNLOCK(p); 1332 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1333} 1334 1335#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1336#ifndef _SYS_SYSPROTO_H_ 1337struct osigpending_args { 1338 int dummy; 1339}; 1340#endif 1341int 1342osigpending(td, uap) 1343 struct thread *td; 1344 struct osigpending_args *uap; 1345{ 1346 struct proc *p = td->td_proc; 1347 sigset_t pending; 1348 1349 PROC_LOCK(p); 1350 pending = p->p_sigqueue.sq_signals; 1351 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1352 PROC_UNLOCK(p); 1353 SIG2OSIG(pending, td->td_retval[0]); 1354 return (0); 1355} 1356#endif /* COMPAT_43 */ 1357 1358#if defined(COMPAT_43) 1359/* 1360 * Generalized interface signal handler, 4.3-compatible. 1361 */ 1362#ifndef _SYS_SYSPROTO_H_ 1363struct osigvec_args { 1364 int signum; 1365 struct sigvec *nsv; 1366 struct sigvec *osv; 1367}; 1368#endif 1369/* ARGSUSED */ 1370int 1371osigvec(td, uap) 1372 struct thread *td; 1373 register struct osigvec_args *uap; 1374{ 1375 struct sigvec vec; 1376 struct sigaction nsa, osa; 1377 register struct sigaction *nsap, *osap; 1378 int error; 1379 1380 if (uap->signum <= 0 || uap->signum >= ONSIG) 1381 return (EINVAL); 1382 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1383 osap = (uap->osv != NULL) ? &osa : NULL; 1384 if (nsap) { 1385 error = copyin(uap->nsv, &vec, sizeof(vec)); 1386 if (error) 1387 return (error); 1388 nsap->sa_handler = vec.sv_handler; 1389 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1390 nsap->sa_flags = vec.sv_flags; 1391 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1392 } 1393 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1394 if (osap && !error) { 1395 vec.sv_handler = osap->sa_handler; 1396 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1397 vec.sv_flags = osap->sa_flags; 1398 vec.sv_flags &= ~SA_NOCLDWAIT; 1399 vec.sv_flags ^= SA_RESTART; 1400 error = copyout(&vec, uap->osv, sizeof(vec)); 1401 } 1402 return (error); 1403} 1404 1405#ifndef _SYS_SYSPROTO_H_ 1406struct osigblock_args { 1407 int mask; 1408}; 1409#endif 1410int 1411osigblock(td, uap) 1412 register struct thread *td; 1413 struct osigblock_args *uap; 1414{ 1415 sigset_t set, oset; 1416 1417 OSIG2SIG(uap->mask, set); 1418 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1419 SIG2OSIG(oset, td->td_retval[0]); 1420 return (0); 1421} 1422 1423#ifndef _SYS_SYSPROTO_H_ 1424struct osigsetmask_args { 1425 int mask; 1426}; 1427#endif 1428int 1429osigsetmask(td, uap) 1430 struct thread *td; 1431 struct osigsetmask_args *uap; 1432{ 1433 sigset_t set, oset; 1434 1435 OSIG2SIG(uap->mask, set); 1436 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1437 SIG2OSIG(oset, td->td_retval[0]); 1438 return (0); 1439} 1440#endif /* COMPAT_43 */ 1441 1442/* 1443 * Suspend calling thread until signal, providing mask to be set in the 1444 * meantime. 1445 */ 1446#ifndef _SYS_SYSPROTO_H_ 1447struct sigsuspend_args { 1448 const sigset_t *sigmask; 1449}; 1450#endif 1451/* ARGSUSED */ 1452int 1453sys_sigsuspend(td, uap) 1454 struct thread *td; 1455 struct sigsuspend_args *uap; 1456{ 1457 sigset_t mask; 1458 int error; 1459 1460 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1461 if (error) 1462 return (error); 1463 return (kern_sigsuspend(td, mask)); 1464} 1465 1466int 1467kern_sigsuspend(struct thread *td, sigset_t mask) 1468{ 1469 struct proc *p = td->td_proc; 1470 int has_sig, sig; 1471 1472 /* 1473 * When returning from sigsuspend, we want 1474 * the old mask to be restored after the 1475 * signal handler has finished. Thus, we 1476 * save it here and mark the sigacts structure 1477 * to indicate this. 1478 */ 1479 PROC_LOCK(p); 1480 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1481 SIGPROCMASK_PROC_LOCKED); 1482 td->td_pflags |= TDP_OLDMASK; 1483 1484 /* 1485 * Process signals now. Otherwise, we can get spurious wakeup 1486 * due to signal entered process queue, but delivered to other 1487 * thread. But sigsuspend should return only on signal 1488 * delivery. 1489 */ 1490 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1491 for (has_sig = 0; !has_sig;) { 1492 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1493 0) == 0) 1494 /* void */; 1495 thread_suspend_check(0); 1496 mtx_lock(&p->p_sigacts->ps_mtx); 1497 while ((sig = cursig(td)) != 0) 1498 has_sig += postsig(sig); 1499 mtx_unlock(&p->p_sigacts->ps_mtx); 1500 } 1501 PROC_UNLOCK(p); 1502 td->td_errno = EINTR; 1503 td->td_pflags |= TDP_NERRNO; 1504 return (EJUSTRETURN); 1505} 1506 1507#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1508/* 1509 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1510 * convention: libc stub passes mask, not pointer, to save a copyin. 1511 */ 1512#ifndef _SYS_SYSPROTO_H_ 1513struct osigsuspend_args { 1514 osigset_t mask; 1515}; 1516#endif 1517/* ARGSUSED */ 1518int 1519osigsuspend(td, uap) 1520 struct thread *td; 1521 struct osigsuspend_args *uap; 1522{ 1523 sigset_t mask; 1524 1525 OSIG2SIG(uap->mask, mask); 1526 return (kern_sigsuspend(td, mask)); 1527} 1528#endif /* COMPAT_43 */ 1529 1530#if defined(COMPAT_43) 1531#ifndef _SYS_SYSPROTO_H_ 1532struct osigstack_args { 1533 struct sigstack *nss; 1534 struct sigstack *oss; 1535}; 1536#endif 1537/* ARGSUSED */ 1538int 1539osigstack(td, uap) 1540 struct thread *td; 1541 register struct osigstack_args *uap; 1542{ 1543 struct sigstack nss, oss; 1544 int error = 0; 1545 1546 if (uap->nss != NULL) { 1547 error = copyin(uap->nss, &nss, sizeof(nss)); 1548 if (error) 1549 return (error); 1550 } 1551 oss.ss_sp = td->td_sigstk.ss_sp; 1552 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1553 if (uap->nss != NULL) { 1554 td->td_sigstk.ss_sp = nss.ss_sp; 1555 td->td_sigstk.ss_size = 0; 1556 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1557 td->td_pflags |= TDP_ALTSTACK; 1558 } 1559 if (uap->oss != NULL) 1560 error = copyout(&oss, uap->oss, sizeof(oss)); 1561 1562 return (error); 1563} 1564#endif /* COMPAT_43 */ 1565 1566#ifndef _SYS_SYSPROTO_H_ 1567struct sigaltstack_args { 1568 stack_t *ss; 1569 stack_t *oss; 1570}; 1571#endif 1572/* ARGSUSED */ 1573int 1574sys_sigaltstack(td, uap) 1575 struct thread *td; 1576 register struct sigaltstack_args *uap; 1577{ 1578 stack_t ss, oss; 1579 int error; 1580 1581 if (uap->ss != NULL) { 1582 error = copyin(uap->ss, &ss, sizeof(ss)); 1583 if (error) 1584 return (error); 1585 } 1586 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1587 (uap->oss != NULL) ? &oss : NULL); 1588 if (error) 1589 return (error); 1590 if (uap->oss != NULL) 1591 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1592 return (error); 1593} 1594 1595int 1596kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1597{ 1598 struct proc *p = td->td_proc; 1599 int oonstack; 1600 1601 oonstack = sigonstack(cpu_getstack(td)); 1602 1603 if (oss != NULL) { 1604 *oss = td->td_sigstk; 1605 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1606 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1607 } 1608 1609 if (ss != NULL) { 1610 if (oonstack) 1611 return (EPERM); 1612 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1613 return (EINVAL); 1614 if (!(ss->ss_flags & SS_DISABLE)) { 1615 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1616 return (ENOMEM); 1617 1618 td->td_sigstk = *ss; 1619 td->td_pflags |= TDP_ALTSTACK; 1620 } else { 1621 td->td_pflags &= ~TDP_ALTSTACK; 1622 } 1623 } 1624 return (0); 1625} 1626 1627/* 1628 * Common code for kill process group/broadcast kill. 1629 * cp is calling process. 1630 */ 1631static int 1632killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1633{ 1634 struct proc *p; 1635 struct pgrp *pgrp; 1636 int err; 1637 int ret; 1638 1639 ret = ESRCH; 1640 if (all) { 1641 /* 1642 * broadcast 1643 */ 1644 sx_slock(&allproc_lock); 1645 FOREACH_PROC_IN_SYSTEM(p) { 1646 PROC_LOCK(p); 1647 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1648 p == td->td_proc || p->p_state == PRS_NEW) { 1649 PROC_UNLOCK(p); 1650 continue; 1651 } 1652 err = p_cansignal(td, p, sig); 1653 if (err == 0) { 1654 if (sig) 1655 pksignal(p, sig, ksi); 1656 ret = err; 1657 } 1658 else if (ret == ESRCH) 1659 ret = err; 1660 PROC_UNLOCK(p); 1661 } 1662 sx_sunlock(&allproc_lock); 1663 } else { 1664 sx_slock(&proctree_lock); 1665 if (pgid == 0) { 1666 /* 1667 * zero pgid means send to my process group. 1668 */ 1669 pgrp = td->td_proc->p_pgrp; 1670 PGRP_LOCK(pgrp); 1671 } else { 1672 pgrp = pgfind(pgid); 1673 if (pgrp == NULL) { 1674 sx_sunlock(&proctree_lock); 1675 return (ESRCH); 1676 } 1677 } 1678 sx_sunlock(&proctree_lock); 1679 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1680 PROC_LOCK(p); 1681 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1682 p->p_state == PRS_NEW) { 1683 PROC_UNLOCK(p); 1684 continue; 1685 } 1686 err = p_cansignal(td, p, sig); 1687 if (err == 0) { 1688 if (sig) 1689 pksignal(p, sig, ksi); 1690 ret = err; 1691 } 1692 else if (ret == ESRCH) 1693 ret = err; 1694 PROC_UNLOCK(p); 1695 } 1696 PGRP_UNLOCK(pgrp); 1697 } 1698 return (ret); 1699} 1700 1701#ifndef _SYS_SYSPROTO_H_ 1702struct kill_args { 1703 int pid; 1704 int signum; 1705}; 1706#endif 1707/* ARGSUSED */ 1708int 1709sys_kill(struct thread *td, struct kill_args *uap) 1710{ 1711 ksiginfo_t ksi; 1712 struct proc *p; 1713 int error; 1714 1715 /* 1716 * A process in capability mode can send signals only to himself. 1717 * The main rationale behind this is that abort(3) is implemented as 1718 * kill(getpid(), SIGABRT). 1719 */ 1720 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1721 return (ECAPMODE); 1722 1723 AUDIT_ARG_SIGNUM(uap->signum); 1724 AUDIT_ARG_PID(uap->pid); 1725 if ((u_int)uap->signum > _SIG_MAXSIG) 1726 return (EINVAL); 1727 1728 ksiginfo_init(&ksi); 1729 ksi.ksi_signo = uap->signum; 1730 ksi.ksi_code = SI_USER; 1731 ksi.ksi_pid = td->td_proc->p_pid; 1732 ksi.ksi_uid = td->td_ucred->cr_ruid; 1733 1734 if (uap->pid > 0) { 1735 /* kill single process */ 1736 if ((p = pfind(uap->pid)) == NULL) { 1737 if ((p = zpfind(uap->pid)) == NULL) 1738 return (ESRCH); 1739 } 1740 AUDIT_ARG_PROCESS(p); 1741 error = p_cansignal(td, p, uap->signum); 1742 if (error == 0 && uap->signum) 1743 pksignal(p, uap->signum, &ksi); 1744 PROC_UNLOCK(p); 1745 return (error); 1746 } 1747 switch (uap->pid) { 1748 case -1: /* broadcast signal */ 1749 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1750 case 0: /* signal own process group */ 1751 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1752 default: /* negative explicit process group */ 1753 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1754 } 1755 /* NOTREACHED */ 1756} 1757 1758int 1759sys_pdkill(td, uap) 1760 struct thread *td; 1761 struct pdkill_args *uap; 1762{ 1763#ifdef PROCDESC 1764 struct proc *p; 1765 cap_rights_t rights; 1766 int error; 1767 1768 AUDIT_ARG_SIGNUM(uap->signum); 1769 AUDIT_ARG_FD(uap->fd); 1770 if ((u_int)uap->signum > _SIG_MAXSIG) 1771 return (EINVAL); 1772 1773 error = procdesc_find(td, uap->fd, 1774 cap_rights_init(&rights, CAP_PDKILL), &p); 1775 if (error) 1776 return (error); 1777 AUDIT_ARG_PROCESS(p); 1778 error = p_cansignal(td, p, uap->signum); 1779 if (error == 0 && uap->signum) 1780 kern_psignal(p, uap->signum); 1781 PROC_UNLOCK(p); 1782 return (error); 1783#else 1784 return (ENOSYS); 1785#endif 1786} 1787 1788#if defined(COMPAT_43) 1789#ifndef _SYS_SYSPROTO_H_ 1790struct okillpg_args { 1791 int pgid; 1792 int signum; 1793}; 1794#endif 1795/* ARGSUSED */ 1796int 1797okillpg(struct thread *td, struct okillpg_args *uap) 1798{ 1799 ksiginfo_t ksi; 1800 1801 AUDIT_ARG_SIGNUM(uap->signum); 1802 AUDIT_ARG_PID(uap->pgid); 1803 if ((u_int)uap->signum > _SIG_MAXSIG) 1804 return (EINVAL); 1805 1806 ksiginfo_init(&ksi); 1807 ksi.ksi_signo = uap->signum; 1808 ksi.ksi_code = SI_USER; 1809 ksi.ksi_pid = td->td_proc->p_pid; 1810 ksi.ksi_uid = td->td_ucred->cr_ruid; 1811 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1812} 1813#endif /* COMPAT_43 */ 1814 1815#ifndef _SYS_SYSPROTO_H_ 1816struct sigqueue_args { 1817 pid_t pid; 1818 int signum; 1819 /* union sigval */ void *value; 1820}; 1821#endif 1822int 1823sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1824{ 1825 ksiginfo_t ksi; 1826 struct proc *p; 1827 int error; 1828 1829 if ((u_int)uap->signum > _SIG_MAXSIG) 1830 return (EINVAL); 1831 1832 /* 1833 * Specification says sigqueue can only send signal to 1834 * single process. 1835 */ 1836 if (uap->pid <= 0) 1837 return (EINVAL); 1838 1839 if ((p = pfind(uap->pid)) == NULL) { 1840 if ((p = zpfind(uap->pid)) == NULL) 1841 return (ESRCH); 1842 } 1843 error = p_cansignal(td, p, uap->signum); 1844 if (error == 0 && uap->signum != 0) { 1845 ksiginfo_init(&ksi); 1846 ksi.ksi_flags = KSI_SIGQ; 1847 ksi.ksi_signo = uap->signum; 1848 ksi.ksi_code = SI_QUEUE; 1849 ksi.ksi_pid = td->td_proc->p_pid; 1850 ksi.ksi_uid = td->td_ucred->cr_ruid; 1851 ksi.ksi_value.sival_ptr = uap->value; 1852 error = pksignal(p, ksi.ksi_signo, &ksi); 1853 } 1854 PROC_UNLOCK(p); 1855 return (error); 1856} 1857 1858/* 1859 * Send a signal to a process group. 1860 */ 1861void 1862gsignal(int pgid, int sig, ksiginfo_t *ksi) 1863{ 1864 struct pgrp *pgrp; 1865 1866 if (pgid != 0) { 1867 sx_slock(&proctree_lock); 1868 pgrp = pgfind(pgid); 1869 sx_sunlock(&proctree_lock); 1870 if (pgrp != NULL) { 1871 pgsignal(pgrp, sig, 0, ksi); 1872 PGRP_UNLOCK(pgrp); 1873 } 1874 } 1875} 1876 1877/* 1878 * Send a signal to a process group. If checktty is 1, 1879 * limit to members which have a controlling terminal. 1880 */ 1881void 1882pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1883{ 1884 struct proc *p; 1885 1886 if (pgrp) { 1887 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1888 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1889 PROC_LOCK(p); 1890 if (p->p_state == PRS_NORMAL && 1891 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1892 pksignal(p, sig, ksi); 1893 PROC_UNLOCK(p); 1894 } 1895 } 1896} 1897 1898 1899/* 1900 * Recalculate the signal mask and reset the signal disposition after 1901 * usermode frame for delivery is formed. Should be called after 1902 * mach-specific routine, because sysent->sv_sendsig() needs correct 1903 * ps_siginfo and signal mask. 1904 */ 1905static void 1906postsig_done(int sig, struct thread *td, struct sigacts *ps) 1907{ 1908 sigset_t mask; 1909 1910 mtx_assert(&ps->ps_mtx, MA_OWNED); 1911 td->td_ru.ru_nsignals++; 1912 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1913 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1914 SIGADDSET(mask, sig); 1915 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1916 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1917 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1918 sigdflt(ps, sig); 1919} 1920 1921 1922/* 1923 * Send a signal caused by a trap to the current thread. If it will be 1924 * caught immediately, deliver it with correct code. Otherwise, post it 1925 * normally. 1926 */ 1927void 1928trapsignal(struct thread *td, ksiginfo_t *ksi) 1929{ 1930 struct sigacts *ps; 1931 struct proc *p; 1932 int sig; 1933 int code; 1934 1935 p = td->td_proc; 1936 sig = ksi->ksi_signo; 1937 code = ksi->ksi_code; 1938 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1939 1940 PROC_LOCK(p); 1941 ps = p->p_sigacts; 1942 mtx_lock(&ps->ps_mtx); 1943 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1944 !SIGISMEMBER(td->td_sigmask, sig)) { 1945#ifdef KTRACE 1946 if (KTRPOINT(curthread, KTR_PSIG)) 1947 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1948 &td->td_sigmask, code); 1949#endif 1950 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1951 ksi, &td->td_sigmask); 1952 postsig_done(sig, td, ps); 1953 mtx_unlock(&ps->ps_mtx); 1954 } else { 1955 /* 1956 * Avoid a possible infinite loop if the thread 1957 * masking the signal or process is ignoring the 1958 * signal. 1959 */ 1960 if (kern_forcesigexit && 1961 (SIGISMEMBER(td->td_sigmask, sig) || 1962 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1963 SIGDELSET(td->td_sigmask, sig); 1964 SIGDELSET(ps->ps_sigcatch, sig); 1965 SIGDELSET(ps->ps_sigignore, sig); 1966 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1967 } 1968 mtx_unlock(&ps->ps_mtx); 1969 p->p_code = code; /* XXX for core dump/debugger */ 1970 p->p_sig = sig; /* XXX to verify code */ 1971 tdsendsignal(p, td, sig, ksi); 1972 } 1973 PROC_UNLOCK(p); 1974} 1975 1976static struct thread * 1977sigtd(struct proc *p, int sig, int prop) 1978{ 1979 struct thread *td, *signal_td; 1980 1981 PROC_LOCK_ASSERT(p, MA_OWNED); 1982 1983 /* 1984 * Check if current thread can handle the signal without 1985 * switching context to another thread. 1986 */ 1987 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1988 return (curthread); 1989 signal_td = NULL; 1990 FOREACH_THREAD_IN_PROC(p, td) { 1991 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1992 signal_td = td; 1993 break; 1994 } 1995 } 1996 if (signal_td == NULL) 1997 signal_td = FIRST_THREAD_IN_PROC(p); 1998 return (signal_td); 1999} 2000 2001/* 2002 * Send the signal to the process. If the signal has an action, the action 2003 * is usually performed by the target process rather than the caller; we add 2004 * the signal to the set of pending signals for the process. 2005 * 2006 * Exceptions: 2007 * o When a stop signal is sent to a sleeping process that takes the 2008 * default action, the process is stopped without awakening it. 2009 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2010 * regardless of the signal action (eg, blocked or ignored). 2011 * 2012 * Other ignored signals are discarded immediately. 2013 * 2014 * NB: This function may be entered from the debugger via the "kill" DDB 2015 * command. There is little that can be done to mitigate the possibly messy 2016 * side effects of this unwise possibility. 2017 */ 2018void 2019kern_psignal(struct proc *p, int sig) 2020{ 2021 ksiginfo_t ksi; 2022 2023 ksiginfo_init(&ksi); 2024 ksi.ksi_signo = sig; 2025 ksi.ksi_code = SI_KERNEL; 2026 (void) tdsendsignal(p, NULL, sig, &ksi); 2027} 2028 2029int 2030pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2031{ 2032 2033 return (tdsendsignal(p, NULL, sig, ksi)); 2034} 2035 2036/* Utility function for finding a thread to send signal event to. */ 2037int 2038sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2039{ 2040 struct thread *td; 2041 2042 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2043 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2044 if (td == NULL) 2045 return (ESRCH); 2046 *ttd = td; 2047 } else { 2048 *ttd = NULL; 2049 PROC_LOCK(p); 2050 } 2051 return (0); 2052} 2053 2054void 2055tdsignal(struct thread *td, int sig) 2056{ 2057 ksiginfo_t ksi; 2058 2059 ksiginfo_init(&ksi); 2060 ksi.ksi_signo = sig; 2061 ksi.ksi_code = SI_KERNEL; 2062 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2063} 2064 2065void 2066tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2067{ 2068 2069 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2070} 2071 2072int 2073tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2074{ 2075 sig_t action; 2076 sigqueue_t *sigqueue; 2077 int prop; 2078 struct sigacts *ps; 2079 int intrval; 2080 int ret = 0; 2081 int wakeup_swapper; 2082 2083 MPASS(td == NULL || p == td->td_proc); 2084 PROC_LOCK_ASSERT(p, MA_OWNED); 2085 2086 if (!_SIG_VALID(sig)) 2087 panic("%s(): invalid signal %d", __func__, sig); 2088 2089 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2090 2091 /* 2092 * IEEE Std 1003.1-2001: return success when killing a zombie. 2093 */ 2094 if (p->p_state == PRS_ZOMBIE) { 2095 if (ksi && (ksi->ksi_flags & KSI_INS)) 2096 ksiginfo_tryfree(ksi); 2097 return (ret); 2098 } 2099 2100 ps = p->p_sigacts; 2101 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2102 prop = sigprop(sig); 2103 2104 if (td == NULL) { 2105 td = sigtd(p, sig, prop); 2106 sigqueue = &p->p_sigqueue; 2107 } else 2108 sigqueue = &td->td_sigqueue; 2109 2110 SDT_PROBE(proc, kernel, , signal__send, td, p, sig, 0, 0 ); 2111 2112 /* 2113 * If the signal is being ignored, 2114 * then we forget about it immediately. 2115 * (Note: we don't set SIGCONT in ps_sigignore, 2116 * and if it is set to SIG_IGN, 2117 * action will be SIG_DFL here.) 2118 */ 2119 mtx_lock(&ps->ps_mtx); 2120 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2121 SDT_PROBE(proc, kernel, , signal__discard, td, p, sig, 0, 0 ); 2122 2123 mtx_unlock(&ps->ps_mtx); 2124 if (ksi && (ksi->ksi_flags & KSI_INS)) 2125 ksiginfo_tryfree(ksi); 2126 return (ret); 2127 } 2128 if (SIGISMEMBER(td->td_sigmask, sig)) 2129 action = SIG_HOLD; 2130 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2131 action = SIG_CATCH; 2132 else 2133 action = SIG_DFL; 2134 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2135 intrval = EINTR; 2136 else 2137 intrval = ERESTART; 2138 mtx_unlock(&ps->ps_mtx); 2139 2140 if (prop & SA_CONT) 2141 sigqueue_delete_stopmask_proc(p); 2142 else if (prop & SA_STOP) { 2143 /* 2144 * If sending a tty stop signal to a member of an orphaned 2145 * process group, discard the signal here if the action 2146 * is default; don't stop the process below if sleeping, 2147 * and don't clear any pending SIGCONT. 2148 */ 2149 if ((prop & SA_TTYSTOP) && 2150 (p->p_pgrp->pg_jobc == 0) && 2151 (action == SIG_DFL)) { 2152 if (ksi && (ksi->ksi_flags & KSI_INS)) 2153 ksiginfo_tryfree(ksi); 2154 return (ret); 2155 } 2156 sigqueue_delete_proc(p, SIGCONT); 2157 if (p->p_flag & P_CONTINUED) { 2158 p->p_flag &= ~P_CONTINUED; 2159 PROC_LOCK(p->p_pptr); 2160 sigqueue_take(p->p_ksi); 2161 PROC_UNLOCK(p->p_pptr); 2162 } 2163 } 2164 2165 ret = sigqueue_add(sigqueue, sig, ksi); 2166 if (ret != 0) 2167 return (ret); 2168 signotify(td); 2169 /* 2170 * Defer further processing for signals which are held, 2171 * except that stopped processes must be continued by SIGCONT. 2172 */ 2173 if (action == SIG_HOLD && 2174 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2175 return (ret); 2176 /* 2177 * SIGKILL: Remove procfs STOPEVENTs. 2178 */ 2179 if (sig == SIGKILL) { 2180 /* from procfs_ioctl.c: PIOCBIC */ 2181 p->p_stops = 0; 2182 /* from procfs_ioctl.c: PIOCCONT */ 2183 p->p_step = 0; 2184 wakeup(&p->p_step); 2185 } 2186 /* 2187 * Some signals have a process-wide effect and a per-thread 2188 * component. Most processing occurs when the process next 2189 * tries to cross the user boundary, however there are some 2190 * times when processing needs to be done immediately, such as 2191 * waking up threads so that they can cross the user boundary. 2192 * We try to do the per-process part here. 2193 */ 2194 if (P_SHOULDSTOP(p)) { 2195 KASSERT(!(p->p_flag & P_WEXIT), 2196 ("signal to stopped but exiting process")); 2197 if (sig == SIGKILL) { 2198 /* 2199 * If traced process is already stopped, 2200 * then no further action is necessary. 2201 */ 2202 if (p->p_flag & P_TRACED) 2203 goto out; 2204 /* 2205 * SIGKILL sets process running. 2206 * It will die elsewhere. 2207 * All threads must be restarted. 2208 */ 2209 p->p_flag &= ~P_STOPPED_SIG; 2210 goto runfast; 2211 } 2212 2213 if (prop & SA_CONT) { 2214 /* 2215 * If traced process is already stopped, 2216 * then no further action is necessary. 2217 */ 2218 if (p->p_flag & P_TRACED) 2219 goto out; 2220 /* 2221 * If SIGCONT is default (or ignored), we continue the 2222 * process but don't leave the signal in sigqueue as 2223 * it has no further action. If SIGCONT is held, we 2224 * continue the process and leave the signal in 2225 * sigqueue. If the process catches SIGCONT, let it 2226 * handle the signal itself. If it isn't waiting on 2227 * an event, it goes back to run state. 2228 * Otherwise, process goes back to sleep state. 2229 */ 2230 p->p_flag &= ~P_STOPPED_SIG; 2231 PROC_SLOCK(p); 2232 if (p->p_numthreads == p->p_suspcount) { 2233 PROC_SUNLOCK(p); 2234 p->p_flag |= P_CONTINUED; 2235 p->p_xstat = SIGCONT; 2236 PROC_LOCK(p->p_pptr); 2237 childproc_continued(p); 2238 PROC_UNLOCK(p->p_pptr); 2239 PROC_SLOCK(p); 2240 } 2241 if (action == SIG_DFL) { 2242 thread_unsuspend(p); 2243 PROC_SUNLOCK(p); 2244 sigqueue_delete(sigqueue, sig); 2245 goto out; 2246 } 2247 if (action == SIG_CATCH) { 2248 /* 2249 * The process wants to catch it so it needs 2250 * to run at least one thread, but which one? 2251 */ 2252 PROC_SUNLOCK(p); 2253 goto runfast; 2254 } 2255 /* 2256 * The signal is not ignored or caught. 2257 */ 2258 thread_unsuspend(p); 2259 PROC_SUNLOCK(p); 2260 goto out; 2261 } 2262 2263 if (prop & SA_STOP) { 2264 /* 2265 * If traced process is already stopped, 2266 * then no further action is necessary. 2267 */ 2268 if (p->p_flag & P_TRACED) 2269 goto out; 2270 /* 2271 * Already stopped, don't need to stop again 2272 * (If we did the shell could get confused). 2273 * Just make sure the signal STOP bit set. 2274 */ 2275 p->p_flag |= P_STOPPED_SIG; 2276 sigqueue_delete(sigqueue, sig); 2277 goto out; 2278 } 2279 2280 /* 2281 * All other kinds of signals: 2282 * If a thread is sleeping interruptibly, simulate a 2283 * wakeup so that when it is continued it will be made 2284 * runnable and can look at the signal. However, don't make 2285 * the PROCESS runnable, leave it stopped. 2286 * It may run a bit until it hits a thread_suspend_check(). 2287 */ 2288 wakeup_swapper = 0; 2289 PROC_SLOCK(p); 2290 thread_lock(td); 2291 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2292 wakeup_swapper = sleepq_abort(td, intrval); 2293 thread_unlock(td); 2294 PROC_SUNLOCK(p); 2295 if (wakeup_swapper) 2296 kick_proc0(); 2297 goto out; 2298 /* 2299 * Mutexes are short lived. Threads waiting on them will 2300 * hit thread_suspend_check() soon. 2301 */ 2302 } else if (p->p_state == PRS_NORMAL) { 2303 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2304 tdsigwakeup(td, sig, action, intrval); 2305 goto out; 2306 } 2307 2308 MPASS(action == SIG_DFL); 2309 2310 if (prop & SA_STOP) { 2311 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2312 goto out; 2313 p->p_flag |= P_STOPPED_SIG; 2314 p->p_xstat = sig; 2315 PROC_SLOCK(p); 2316 sig_suspend_threads(td, p, 1); 2317 if (p->p_numthreads == p->p_suspcount) { 2318 /* 2319 * only thread sending signal to another 2320 * process can reach here, if thread is sending 2321 * signal to its process, because thread does 2322 * not suspend itself here, p_numthreads 2323 * should never be equal to p_suspcount. 2324 */ 2325 thread_stopped(p); 2326 PROC_SUNLOCK(p); 2327 sigqueue_delete_proc(p, p->p_xstat); 2328 } else 2329 PROC_SUNLOCK(p); 2330 goto out; 2331 } 2332 } else { 2333 /* Not in "NORMAL" state. discard the signal. */ 2334 sigqueue_delete(sigqueue, sig); 2335 goto out; 2336 } 2337 2338 /* 2339 * The process is not stopped so we need to apply the signal to all the 2340 * running threads. 2341 */ 2342runfast: 2343 tdsigwakeup(td, sig, action, intrval); 2344 PROC_SLOCK(p); 2345 thread_unsuspend(p); 2346 PROC_SUNLOCK(p); 2347out: 2348 /* If we jump here, proc slock should not be owned. */ 2349 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2350 return (ret); 2351} 2352 2353/* 2354 * The force of a signal has been directed against a single 2355 * thread. We need to see what we can do about knocking it 2356 * out of any sleep it may be in etc. 2357 */ 2358static void 2359tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2360{ 2361 struct proc *p = td->td_proc; 2362 register int prop; 2363 int wakeup_swapper; 2364 2365 wakeup_swapper = 0; 2366 PROC_LOCK_ASSERT(p, MA_OWNED); 2367 prop = sigprop(sig); 2368 2369 PROC_SLOCK(p); 2370 thread_lock(td); 2371 /* 2372 * Bring the priority of a thread up if we want it to get 2373 * killed in this lifetime. 2374 */ 2375 if (action == SIG_DFL && (prop & SA_KILL) && td->td_priority > PUSER) 2376 sched_prio(td, PUSER); 2377 if (TD_ON_SLEEPQ(td)) { 2378 /* 2379 * If thread is sleeping uninterruptibly 2380 * we can't interrupt the sleep... the signal will 2381 * be noticed when the process returns through 2382 * trap() or syscall(). 2383 */ 2384 if ((td->td_flags & TDF_SINTR) == 0) 2385 goto out; 2386 /* 2387 * If SIGCONT is default (or ignored) and process is 2388 * asleep, we are finished; the process should not 2389 * be awakened. 2390 */ 2391 if ((prop & SA_CONT) && action == SIG_DFL) { 2392 thread_unlock(td); 2393 PROC_SUNLOCK(p); 2394 sigqueue_delete(&p->p_sigqueue, sig); 2395 /* 2396 * It may be on either list in this state. 2397 * Remove from both for now. 2398 */ 2399 sigqueue_delete(&td->td_sigqueue, sig); 2400 return; 2401 } 2402 2403 /* 2404 * Don't awaken a sleeping thread for SIGSTOP if the 2405 * STOP signal is deferred. 2406 */ 2407 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2408 goto out; 2409 2410 /* 2411 * Give low priority threads a better chance to run. 2412 */ 2413 if (td->td_priority > PUSER) 2414 sched_prio(td, PUSER); 2415 2416 wakeup_swapper = sleepq_abort(td, intrval); 2417 } else { 2418 /* 2419 * Other states do nothing with the signal immediately, 2420 * other than kicking ourselves if we are running. 2421 * It will either never be noticed, or noticed very soon. 2422 */ 2423#ifdef SMP 2424 if (TD_IS_RUNNING(td) && td != curthread) 2425 forward_signal(td); 2426#endif 2427 } 2428out: 2429 PROC_SUNLOCK(p); 2430 thread_unlock(td); 2431 if (wakeup_swapper) 2432 kick_proc0(); 2433} 2434 2435static void 2436sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2437{ 2438 struct thread *td2; 2439 2440 PROC_LOCK_ASSERT(p, MA_OWNED); 2441 PROC_SLOCK_ASSERT(p, MA_OWNED); 2442 2443 FOREACH_THREAD_IN_PROC(p, td2) { 2444 thread_lock(td2); 2445 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2446 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2447 (td2->td_flags & TDF_SINTR)) { 2448 if (td2->td_flags & TDF_SBDRY) { 2449 /* 2450 * Once a thread is asleep with 2451 * TDF_SBDRY set, it should never 2452 * become suspended due to this check. 2453 */ 2454 KASSERT(!TD_IS_SUSPENDED(td2), 2455 ("thread with deferred stops suspended")); 2456 } else if (!TD_IS_SUSPENDED(td2)) { 2457 thread_suspend_one(td2); 2458 } 2459 } else if (!TD_IS_SUSPENDED(td2)) { 2460 if (sending || td != td2) 2461 td2->td_flags |= TDF_ASTPENDING; 2462#ifdef SMP 2463 if (TD_IS_RUNNING(td2) && td2 != td) 2464 forward_signal(td2); 2465#endif 2466 } 2467 thread_unlock(td2); 2468 } 2469} 2470 2471int 2472ptracestop(struct thread *td, int sig) 2473{ 2474 struct proc *p = td->td_proc; 2475 2476 PROC_LOCK_ASSERT(p, MA_OWNED); 2477 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2478 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2479 &p->p_mtx.lock_object, "Stopping for traced signal"); 2480 2481 td->td_dbgflags |= TDB_XSIG; 2482 td->td_xsig = sig; 2483 PROC_SLOCK(p); 2484 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2485 if (p->p_flag & P_SINGLE_EXIT) { 2486 td->td_dbgflags &= ~TDB_XSIG; 2487 PROC_SUNLOCK(p); 2488 return (sig); 2489 } 2490 /* 2491 * Just make wait() to work, the last stopped thread 2492 * will win. 2493 */ 2494 p->p_xstat = sig; 2495 p->p_xthread = td; 2496 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2497 sig_suspend_threads(td, p, 0); 2498 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2499 td->td_dbgflags &= ~TDB_STOPATFORK; 2500 cv_broadcast(&p->p_dbgwait); 2501 } 2502stopme: 2503 thread_suspend_switch(td, p); 2504 if (p->p_xthread == td) 2505 p->p_xthread = NULL; 2506 if (!(p->p_flag & P_TRACED)) 2507 break; 2508 if (td->td_dbgflags & TDB_SUSPEND) { 2509 if (p->p_flag & P_SINGLE_EXIT) 2510 break; 2511 goto stopme; 2512 } 2513 } 2514 PROC_SUNLOCK(p); 2515 return (td->td_xsig); 2516} 2517 2518static void 2519reschedule_signals(struct proc *p, sigset_t block, int flags) 2520{ 2521 struct sigacts *ps; 2522 struct thread *td; 2523 int sig; 2524 2525 PROC_LOCK_ASSERT(p, MA_OWNED); 2526 ps = p->p_sigacts; 2527 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2528 MA_OWNED : MA_NOTOWNED); 2529 if (SIGISEMPTY(p->p_siglist)) 2530 return; 2531 SIGSETAND(block, p->p_siglist); 2532 while ((sig = sig_ffs(&block)) != 0) { 2533 SIGDELSET(block, sig); 2534 td = sigtd(p, sig, 0); 2535 signotify(td); 2536 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2537 mtx_lock(&ps->ps_mtx); 2538 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2539 tdsigwakeup(td, sig, SIG_CATCH, 2540 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2541 ERESTART)); 2542 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2543 mtx_unlock(&ps->ps_mtx); 2544 } 2545} 2546 2547void 2548tdsigcleanup(struct thread *td) 2549{ 2550 struct proc *p; 2551 sigset_t unblocked; 2552 2553 p = td->td_proc; 2554 PROC_LOCK_ASSERT(p, MA_OWNED); 2555 2556 sigqueue_flush(&td->td_sigqueue); 2557 if (p->p_numthreads == 1) 2558 return; 2559 2560 /* 2561 * Since we cannot handle signals, notify signal post code 2562 * about this by filling the sigmask. 2563 * 2564 * Also, if needed, wake up thread(s) that do not block the 2565 * same signals as the exiting thread, since the thread might 2566 * have been selected for delivery and woken up. 2567 */ 2568 SIGFILLSET(unblocked); 2569 SIGSETNAND(unblocked, td->td_sigmask); 2570 SIGFILLSET(td->td_sigmask); 2571 reschedule_signals(p, unblocked, 0); 2572 2573} 2574 2575/* 2576 * Defer the delivery of SIGSTOP for the current thread. Returns true 2577 * if stops were deferred and false if they were already deferred. 2578 */ 2579int 2580sigdeferstop(void) 2581{ 2582 struct thread *td; 2583 2584 td = curthread; 2585 if (td->td_flags & TDF_SBDRY) 2586 return (0); 2587 thread_lock(td); 2588 td->td_flags |= TDF_SBDRY; 2589 thread_unlock(td); 2590 return (1); 2591} 2592 2593/* 2594 * Permit the delivery of SIGSTOP for the current thread. This does 2595 * not immediately suspend if a stop was posted. Instead, the thread 2596 * will suspend either via ast() or a subsequent interruptible sleep. 2597 */ 2598void 2599sigallowstop() 2600{ 2601 struct thread *td; 2602 2603 td = curthread; 2604 thread_lock(td); 2605 td->td_flags &= ~TDF_SBDRY; 2606 thread_unlock(td); 2607} 2608 2609/* 2610 * If the current process has received a signal (should be caught or cause 2611 * termination, should interrupt current syscall), return the signal number. 2612 * Stop signals with default action are processed immediately, then cleared; 2613 * they aren't returned. This is checked after each entry to the system for 2614 * a syscall or trap (though this can usually be done without calling issignal 2615 * by checking the pending signal masks in cursig.) The normal call 2616 * sequence is 2617 * 2618 * while (sig = cursig(curthread)) 2619 * postsig(sig); 2620 */ 2621static int 2622issignal(struct thread *td) 2623{ 2624 struct proc *p; 2625 struct sigacts *ps; 2626 struct sigqueue *queue; 2627 sigset_t sigpending; 2628 int sig, prop, newsig; 2629 2630 p = td->td_proc; 2631 ps = p->p_sigacts; 2632 mtx_assert(&ps->ps_mtx, MA_OWNED); 2633 PROC_LOCK_ASSERT(p, MA_OWNED); 2634 for (;;) { 2635 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2636 2637 sigpending = td->td_sigqueue.sq_signals; 2638 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2639 SIGSETNAND(sigpending, td->td_sigmask); 2640 2641 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2642 SIG_STOPSIGMASK(sigpending); 2643 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2644 return (0); 2645 sig = sig_ffs(&sigpending); 2646 2647 if (p->p_stops & S_SIG) { 2648 mtx_unlock(&ps->ps_mtx); 2649 stopevent(p, S_SIG, sig); 2650 mtx_lock(&ps->ps_mtx); 2651 } 2652 2653 /* 2654 * We should see pending but ignored signals 2655 * only if P_TRACED was on when they were posted. 2656 */ 2657 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2658 sigqueue_delete(&td->td_sigqueue, sig); 2659 sigqueue_delete(&p->p_sigqueue, sig); 2660 continue; 2661 } 2662 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2663 /* 2664 * If traced, always stop. 2665 * Remove old signal from queue before the stop. 2666 * XXX shrug off debugger, it causes siginfo to 2667 * be thrown away. 2668 */ 2669 queue = &td->td_sigqueue; 2670 td->td_dbgksi.ksi_signo = 0; 2671 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2672 queue = &p->p_sigqueue; 2673 sigqueue_get(queue, sig, &td->td_dbgksi); 2674 } 2675 2676 mtx_unlock(&ps->ps_mtx); 2677 newsig = ptracestop(td, sig); 2678 mtx_lock(&ps->ps_mtx); 2679 2680 if (sig != newsig) { 2681 2682 /* 2683 * If parent wants us to take the signal, 2684 * then it will leave it in p->p_xstat; 2685 * otherwise we just look for signals again. 2686 */ 2687 if (newsig == 0) 2688 continue; 2689 sig = newsig; 2690 2691 /* 2692 * Put the new signal into td_sigqueue. If the 2693 * signal is being masked, look for other 2694 * signals. 2695 */ 2696 sigqueue_add(queue, sig, NULL); 2697 if (SIGISMEMBER(td->td_sigmask, sig)) 2698 continue; 2699 signotify(td); 2700 } else { 2701 if (td->td_dbgksi.ksi_signo != 0) { 2702 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2703 if (sigqueue_add(&td->td_sigqueue, sig, 2704 &td->td_dbgksi) != 0) 2705 td->td_dbgksi.ksi_signo = 0; 2706 } 2707 if (td->td_dbgksi.ksi_signo == 0) 2708 sigqueue_add(&td->td_sigqueue, sig, 2709 NULL); 2710 } 2711 2712 /* 2713 * If the traced bit got turned off, go back up 2714 * to the top to rescan signals. This ensures 2715 * that p_sig* and p_sigact are consistent. 2716 */ 2717 if ((p->p_flag & P_TRACED) == 0) 2718 continue; 2719 } 2720 2721 prop = sigprop(sig); 2722 2723 /* 2724 * Decide whether the signal should be returned. 2725 * Return the signal's number, or fall through 2726 * to clear it from the pending mask. 2727 */ 2728 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2729 2730 case (intptr_t)SIG_DFL: 2731 /* 2732 * Don't take default actions on system processes. 2733 */ 2734 if (p->p_pid <= 1) { 2735#ifdef DIAGNOSTIC 2736 /* 2737 * Are you sure you want to ignore SIGSEGV 2738 * in init? XXX 2739 */ 2740 printf("Process (pid %lu) got signal %d\n", 2741 (u_long)p->p_pid, sig); 2742#endif 2743 break; /* == ignore */ 2744 } 2745 /* 2746 * If there is a pending stop signal to process 2747 * with default action, stop here, 2748 * then clear the signal. However, 2749 * if process is member of an orphaned 2750 * process group, ignore tty stop signals. 2751 */ 2752 if (prop & SA_STOP) { 2753 if (p->p_flag & (P_TRACED|P_WEXIT) || 2754 (p->p_pgrp->pg_jobc == 0 && 2755 prop & SA_TTYSTOP)) 2756 break; /* == ignore */ 2757 mtx_unlock(&ps->ps_mtx); 2758 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2759 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2760 p->p_flag |= P_STOPPED_SIG; 2761 p->p_xstat = sig; 2762 PROC_SLOCK(p); 2763 sig_suspend_threads(td, p, 0); 2764 thread_suspend_switch(td, p); 2765 PROC_SUNLOCK(p); 2766 mtx_lock(&ps->ps_mtx); 2767 break; 2768 } else if (prop & SA_IGNORE) { 2769 /* 2770 * Except for SIGCONT, shouldn't get here. 2771 * Default action is to ignore; drop it. 2772 */ 2773 break; /* == ignore */ 2774 } else 2775 return (sig); 2776 /*NOTREACHED*/ 2777 2778 case (intptr_t)SIG_IGN: 2779 /* 2780 * Masking above should prevent us ever trying 2781 * to take action on an ignored signal other 2782 * than SIGCONT, unless process is traced. 2783 */ 2784 if ((prop & SA_CONT) == 0 && 2785 (p->p_flag & P_TRACED) == 0) 2786 printf("issignal\n"); 2787 break; /* == ignore */ 2788 2789 default: 2790 /* 2791 * This signal has an action, let 2792 * postsig() process it. 2793 */ 2794 return (sig); 2795 } 2796 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2797 sigqueue_delete(&p->p_sigqueue, sig); 2798 } 2799 /* NOTREACHED */ 2800} 2801 2802void 2803thread_stopped(struct proc *p) 2804{ 2805 int n; 2806 2807 PROC_LOCK_ASSERT(p, MA_OWNED); 2808 PROC_SLOCK_ASSERT(p, MA_OWNED); 2809 n = p->p_suspcount; 2810 if (p == curproc) 2811 n++; 2812 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2813 PROC_SUNLOCK(p); 2814 p->p_flag &= ~P_WAITED; 2815 PROC_LOCK(p->p_pptr); 2816 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2817 CLD_TRAPPED : CLD_STOPPED); 2818 PROC_UNLOCK(p->p_pptr); 2819 PROC_SLOCK(p); 2820 } 2821} 2822 2823/* 2824 * Take the action for the specified signal 2825 * from the current set of pending signals. 2826 */ 2827int 2828postsig(sig) 2829 register int sig; 2830{ 2831 struct thread *td = curthread; 2832 register struct proc *p = td->td_proc; 2833 struct sigacts *ps; 2834 sig_t action; 2835 ksiginfo_t ksi; 2836 sigset_t returnmask; 2837 2838 KASSERT(sig != 0, ("postsig")); 2839 2840 PROC_LOCK_ASSERT(p, MA_OWNED); 2841 ps = p->p_sigacts; 2842 mtx_assert(&ps->ps_mtx, MA_OWNED); 2843 ksiginfo_init(&ksi); 2844 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2845 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2846 return (0); 2847 ksi.ksi_signo = sig; 2848 if (ksi.ksi_code == SI_TIMER) 2849 itimer_accept(p, ksi.ksi_timerid, &ksi); 2850 action = ps->ps_sigact[_SIG_IDX(sig)]; 2851#ifdef KTRACE 2852 if (KTRPOINT(td, KTR_PSIG)) 2853 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2854 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2855#endif 2856 if (p->p_stops & S_SIG) { 2857 mtx_unlock(&ps->ps_mtx); 2858 stopevent(p, S_SIG, sig); 2859 mtx_lock(&ps->ps_mtx); 2860 } 2861 2862 if (action == SIG_DFL) { 2863 /* 2864 * Default action, where the default is to kill 2865 * the process. (Other cases were ignored above.) 2866 */ 2867 mtx_unlock(&ps->ps_mtx); 2868 sigexit(td, sig); 2869 /* NOTREACHED */ 2870 } else { 2871 /* 2872 * If we get here, the signal must be caught. 2873 */ 2874 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2875 ("postsig action")); 2876 /* 2877 * Set the new mask value and also defer further 2878 * occurrences of this signal. 2879 * 2880 * Special case: user has done a sigsuspend. Here the 2881 * current mask is not of interest, but rather the 2882 * mask from before the sigsuspend is what we want 2883 * restored after the signal processing is completed. 2884 */ 2885 if (td->td_pflags & TDP_OLDMASK) { 2886 returnmask = td->td_oldsigmask; 2887 td->td_pflags &= ~TDP_OLDMASK; 2888 } else 2889 returnmask = td->td_sigmask; 2890 2891 if (p->p_sig == sig) { 2892 p->p_code = 0; 2893 p->p_sig = 0; 2894 } 2895 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2896 postsig_done(sig, td, ps); 2897 } 2898 return (1); 2899} 2900 2901/* 2902 * Kill the current process for stated reason. 2903 */ 2904void 2905killproc(p, why) 2906 struct proc *p; 2907 char *why; 2908{ 2909 2910 PROC_LOCK_ASSERT(p, MA_OWNED); 2911 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2912 p->p_comm); 2913 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2914 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2915 p->p_flag |= P_WKILLED; 2916 kern_psignal(p, SIGKILL); 2917} 2918 2919/* 2920 * Force the current process to exit with the specified signal, dumping core 2921 * if appropriate. We bypass the normal tests for masked and caught signals, 2922 * allowing unrecoverable failures to terminate the process without changing 2923 * signal state. Mark the accounting record with the signal termination. 2924 * If dumping core, save the signal number for the debugger. Calls exit and 2925 * does not return. 2926 */ 2927void 2928sigexit(td, sig) 2929 struct thread *td; 2930 int sig; 2931{ 2932 struct proc *p = td->td_proc; 2933 2934 PROC_LOCK_ASSERT(p, MA_OWNED); 2935 p->p_acflag |= AXSIG; 2936 /* 2937 * We must be single-threading to generate a core dump. This 2938 * ensures that the registers in the core file are up-to-date. 2939 * Also, the ELF dump handler assumes that the thread list doesn't 2940 * change out from under it. 2941 * 2942 * XXX If another thread attempts to single-thread before us 2943 * (e.g. via fork()), we won't get a dump at all. 2944 */ 2945 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 2946 p->p_sig = sig; 2947 /* 2948 * Log signals which would cause core dumps 2949 * (Log as LOG_INFO to appease those who don't want 2950 * these messages.) 2951 * XXX : Todo, as well as euid, write out ruid too 2952 * Note that coredump() drops proc lock. 2953 */ 2954 if (coredump(td) == 0) 2955 sig |= WCOREFLAG; 2956 if (kern_logsigexit) 2957 log(LOG_INFO, 2958 "pid %d (%s), uid %d: exited on signal %d%s\n", 2959 p->p_pid, p->p_comm, 2960 td->td_ucred ? td->td_ucred->cr_uid : -1, 2961 sig &~ WCOREFLAG, 2962 sig & WCOREFLAG ? " (core dumped)" : ""); 2963 } else 2964 PROC_UNLOCK(p); 2965 exit1(td, W_EXITCODE(0, sig)); 2966 /* NOTREACHED */ 2967} 2968 2969/* 2970 * Send queued SIGCHLD to parent when child process's state 2971 * is changed. 2972 */ 2973static void 2974sigparent(struct proc *p, int reason, int status) 2975{ 2976 PROC_LOCK_ASSERT(p, MA_OWNED); 2977 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2978 2979 if (p->p_ksi != NULL) { 2980 p->p_ksi->ksi_signo = SIGCHLD; 2981 p->p_ksi->ksi_code = reason; 2982 p->p_ksi->ksi_status = status; 2983 p->p_ksi->ksi_pid = p->p_pid; 2984 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2985 if (KSI_ONQ(p->p_ksi)) 2986 return; 2987 } 2988 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 2989} 2990 2991static void 2992childproc_jobstate(struct proc *p, int reason, int sig) 2993{ 2994 struct sigacts *ps; 2995 2996 PROC_LOCK_ASSERT(p, MA_OWNED); 2997 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2998 2999 /* 3000 * Wake up parent sleeping in kern_wait(), also send 3001 * SIGCHLD to parent, but SIGCHLD does not guarantee 3002 * that parent will awake, because parent may masked 3003 * the signal. 3004 */ 3005 p->p_pptr->p_flag |= P_STATCHILD; 3006 wakeup(p->p_pptr); 3007 3008 ps = p->p_pptr->p_sigacts; 3009 mtx_lock(&ps->ps_mtx); 3010 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3011 mtx_unlock(&ps->ps_mtx); 3012 sigparent(p, reason, sig); 3013 } else 3014 mtx_unlock(&ps->ps_mtx); 3015} 3016 3017void 3018childproc_stopped(struct proc *p, int reason) 3019{ 3020 /* p_xstat is a plain signal number, not a full wait() status here. */ 3021 childproc_jobstate(p, reason, p->p_xstat); 3022} 3023 3024void 3025childproc_continued(struct proc *p) 3026{ 3027 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3028} 3029 3030void 3031childproc_exited(struct proc *p) 3032{ 3033 int reason; 3034 int xstat = p->p_xstat; /* convert to int */ 3035 int status; 3036 3037 if (WCOREDUMP(xstat)) 3038 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3039 else if (WIFSIGNALED(xstat)) 3040 reason = CLD_KILLED, status = WTERMSIG(xstat); 3041 else 3042 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3043 /* 3044 * XXX avoid calling wakeup(p->p_pptr), the work is 3045 * done in exit1(). 3046 */ 3047 sigparent(p, reason, status); 3048} 3049 3050/* 3051 * We only have 1 character for the core count in the format 3052 * string, so the range will be 0-9 3053 */ 3054#define MAX_NUM_CORES 10 3055static int num_cores = 5; 3056 3057static int 3058sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3059{ 3060 int error; 3061 int new_val; 3062 3063 new_val = num_cores; 3064 error = sysctl_handle_int(oidp, &new_val, 0, req); 3065 if (error != 0 || req->newptr == NULL) 3066 return (error); 3067 if (new_val > MAX_NUM_CORES) 3068 new_val = MAX_NUM_CORES; 3069 if (new_val < 0) 3070 new_val = 0; 3071 num_cores = new_val; 3072 return (0); 3073} 3074SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3075 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3076 3077#if defined(COMPRESS_USER_CORES) 3078int compress_user_cores = 1; 3079SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3080 &compress_user_cores, 0, "Compression of user corefiles"); 3081 3082int compress_user_cores_gzlevel = -1; /* default level */ 3083SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3084 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3085 3086#define GZ_SUFFIX ".gz" 3087#define GZ_SUFFIX_LEN 3 3088#endif 3089 3090static char corefilename[MAXPATHLEN] = {"%N.core"}; 3091TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3092SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3093 sizeof(corefilename), "Process corefile name format string"); 3094 3095/* 3096 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3097 * Expand the name described in corefilename, using name, uid, and pid 3098 * and open/create core file. 3099 * corefilename is a printf-like string, with three format specifiers: 3100 * %N name of process ("name") 3101 * %P process id (pid) 3102 * %U user id (uid) 3103 * For example, "%N.core" is the default; they can be disabled completely 3104 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3105 * This is controlled by the sysctl variable kern.corefile (see above). 3106 */ 3107static int 3108corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3109 int compress, struct vnode **vpp, char **namep) 3110{ 3111 struct nameidata nd; 3112 struct sbuf sb; 3113 const char *format; 3114 char *hostname, *name; 3115 int indexpos, i, error, cmode, flags, oflags; 3116 3117 hostname = NULL; 3118 format = corefilename; 3119 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3120 indexpos = -1; 3121 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3122 for (i = 0; format[i] != '\0'; i++) { 3123 switch (format[i]) { 3124 case '%': /* Format character */ 3125 i++; 3126 switch (format[i]) { 3127 case '%': 3128 sbuf_putc(&sb, '%'); 3129 break; 3130 case 'H': /* hostname */ 3131 if (hostname == NULL) { 3132 hostname = malloc(MAXHOSTNAMELEN, 3133 M_TEMP, M_WAITOK); 3134 } 3135 getcredhostname(td->td_ucred, hostname, 3136 MAXHOSTNAMELEN); 3137 sbuf_printf(&sb, "%s", hostname); 3138 break; 3139 case 'I': /* autoincrementing index */ 3140 sbuf_printf(&sb, "0"); 3141 indexpos = sbuf_len(&sb) - 1; 3142 break; 3143 case 'N': /* process name */ 3144 sbuf_printf(&sb, "%s", comm); 3145 break; 3146 case 'P': /* process id */ 3147 sbuf_printf(&sb, "%u", pid); 3148 break; 3149 case 'U': /* user id */ 3150 sbuf_printf(&sb, "%u", uid); 3151 break; 3152 default: 3153 log(LOG_ERR, 3154 "Unknown format character %c in " 3155 "corename `%s'\n", format[i], format); 3156 break; 3157 } 3158 break; 3159 default: 3160 sbuf_putc(&sb, format[i]); 3161 break; 3162 } 3163 } 3164 free(hostname, M_TEMP); 3165#ifdef COMPRESS_USER_CORES 3166 if (compress) 3167 sbuf_printf(&sb, GZ_SUFFIX); 3168#endif 3169 if (sbuf_error(&sb) != 0) { 3170 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3171 "long\n", (long)pid, comm, (u_long)uid); 3172 sbuf_delete(&sb); 3173 free(name, M_TEMP); 3174 return (ENOMEM); 3175 } 3176 sbuf_finish(&sb); 3177 sbuf_delete(&sb); 3178 3179 cmode = S_IRUSR | S_IWUSR; 3180 oflags = VN_OPEN_NOAUDIT | (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3181 3182 /* 3183 * If the core format has a %I in it, then we need to check 3184 * for existing corefiles before returning a name. 3185 * To do this we iterate over 0..num_cores to find a 3186 * non-existing core file name to use. 3187 */ 3188 if (indexpos != -1) { 3189 for (i = 0; i < num_cores; i++) { 3190 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3191 name[indexpos] = '0' + i; 3192 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3193 error = vn_open_cred(&nd, &flags, cmode, oflags, 3194 td->td_ucred, NULL); 3195 if (error) { 3196 if (error == EEXIST) 3197 continue; 3198 log(LOG_ERR, 3199 "pid %d (%s), uid (%u): Path `%s' failed " 3200 "on initial open test, error = %d\n", 3201 pid, comm, uid, name, error); 3202 } 3203 goto out; 3204 } 3205 } 3206 3207 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3208 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3209 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3210out: 3211 if (error) { 3212#ifdef AUDIT 3213 audit_proc_coredump(td, name, error); 3214#endif 3215 free(name, M_TEMP); 3216 return (error); 3217 } 3218 NDFREE(&nd, NDF_ONLY_PNBUF); 3219 *vpp = nd.ni_vp; 3220 *namep = name; 3221 return (0); 3222} 3223 3224/* 3225 * Dump a process' core. The main routine does some 3226 * policy checking, and creates the name of the coredump; 3227 * then it passes on a vnode and a size limit to the process-specific 3228 * coredump routine if there is one; if there _is not_ one, it returns 3229 * ENOSYS; otherwise it returns the error from the process-specific routine. 3230 */ 3231 3232static int 3233coredump(struct thread *td) 3234{ 3235 struct proc *p = td->td_proc; 3236 struct ucred *cred = td->td_ucred; 3237 struct vnode *vp; 3238 struct flock lf; 3239 struct vattr vattr; 3240 int error, error1, locked; 3241 struct mount *mp; 3242 char *name; /* name of corefile */ 3243 off_t limit; 3244 int compress; 3245 3246#ifdef COMPRESS_USER_CORES 3247 compress = compress_user_cores; 3248#else 3249 compress = 0; 3250#endif 3251 PROC_LOCK_ASSERT(p, MA_OWNED); 3252 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3253 _STOPEVENT(p, S_CORE, 0); 3254 3255 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0)) { 3256 PROC_UNLOCK(p); 3257 return (EFAULT); 3258 } 3259 3260 /* 3261 * Note that the bulk of limit checking is done after 3262 * the corefile is created. The exception is if the limit 3263 * for corefiles is 0, in which case we don't bother 3264 * creating the corefile at all. This layout means that 3265 * a corefile is truncated instead of not being created, 3266 * if it is larger than the limit. 3267 */ 3268 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3269 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3270 PROC_UNLOCK(p); 3271 return (EFBIG); 3272 } 3273 PROC_UNLOCK(p); 3274 3275restart: 3276 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3277 &vp, &name); 3278 if (error != 0) 3279 return (error); 3280 3281 /* Don't dump to non-regular files or files with links. */ 3282 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3283 vattr.va_nlink != 1) { 3284 VOP_UNLOCK(vp, 0); 3285 error = EFAULT; 3286 goto close; 3287 } 3288 3289 VOP_UNLOCK(vp, 0); 3290 lf.l_whence = SEEK_SET; 3291 lf.l_start = 0; 3292 lf.l_len = 0; 3293 lf.l_type = F_WRLCK; 3294 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3295 3296 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3297 lf.l_type = F_UNLCK; 3298 if (locked) 3299 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3300 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3301 goto out; 3302 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3303 goto out; 3304 free(name, M_TEMP); 3305 goto restart; 3306 } 3307 3308 VATTR_NULL(&vattr); 3309 vattr.va_size = 0; 3310 if (set_core_nodump_flag) 3311 vattr.va_flags = UF_NODUMP; 3312 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3313 VOP_SETATTR(vp, &vattr, cred); 3314 VOP_UNLOCK(vp, 0); 3315 vn_finished_write(mp); 3316 PROC_LOCK(p); 3317 p->p_acflag |= ACORE; 3318 PROC_UNLOCK(p); 3319 3320 if (p->p_sysent->sv_coredump != NULL) { 3321 error = p->p_sysent->sv_coredump(td, vp, limit, 3322 compress ? IMGACT_CORE_COMPRESS : 0); 3323 } else { 3324 error = ENOSYS; 3325 } 3326 3327 if (locked) { 3328 lf.l_type = F_UNLCK; 3329 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3330 } 3331close: 3332 error1 = vn_close(vp, FWRITE, cred, td); 3333 if (error == 0) 3334 error = error1; 3335out: 3336#ifdef AUDIT 3337 audit_proc_coredump(td, name, error); 3338#endif 3339 free(name, M_TEMP); 3340 return (error); 3341} 3342 3343/* 3344 * Nonexistent system call-- signal process (may want to handle it). Flag 3345 * error in case process won't see signal immediately (blocked or ignored). 3346 */ 3347#ifndef _SYS_SYSPROTO_H_ 3348struct nosys_args { 3349 int dummy; 3350}; 3351#endif 3352/* ARGSUSED */ 3353int 3354nosys(td, args) 3355 struct thread *td; 3356 struct nosys_args *args; 3357{ 3358 struct proc *p = td->td_proc; 3359 3360 PROC_LOCK(p); 3361 tdsignal(td, SIGSYS); 3362 PROC_UNLOCK(p); 3363 return (ENOSYS); 3364} 3365 3366/* 3367 * Send a SIGIO or SIGURG signal to a process or process group using stored 3368 * credentials rather than those of the current process. 3369 */ 3370void 3371pgsigio(sigiop, sig, checkctty) 3372 struct sigio **sigiop; 3373 int sig, checkctty; 3374{ 3375 ksiginfo_t ksi; 3376 struct sigio *sigio; 3377 3378 ksiginfo_init(&ksi); 3379 ksi.ksi_signo = sig; 3380 ksi.ksi_code = SI_KERNEL; 3381 3382 SIGIO_LOCK(); 3383 sigio = *sigiop; 3384 if (sigio == NULL) { 3385 SIGIO_UNLOCK(); 3386 return; 3387 } 3388 if (sigio->sio_pgid > 0) { 3389 PROC_LOCK(sigio->sio_proc); 3390 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3391 kern_psignal(sigio->sio_proc, sig); 3392 PROC_UNLOCK(sigio->sio_proc); 3393 } else if (sigio->sio_pgid < 0) { 3394 struct proc *p; 3395 3396 PGRP_LOCK(sigio->sio_pgrp); 3397 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3398 PROC_LOCK(p); 3399 if (p->p_state == PRS_NORMAL && 3400 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3401 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3402 kern_psignal(p, sig); 3403 PROC_UNLOCK(p); 3404 } 3405 PGRP_UNLOCK(sigio->sio_pgrp); 3406 } 3407 SIGIO_UNLOCK(); 3408} 3409 3410static int 3411filt_sigattach(struct knote *kn) 3412{ 3413 struct proc *p = curproc; 3414 3415 kn->kn_ptr.p_proc = p; 3416 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3417 3418 knlist_add(&p->p_klist, kn, 0); 3419 3420 return (0); 3421} 3422 3423static void 3424filt_sigdetach(struct knote *kn) 3425{ 3426 struct proc *p = kn->kn_ptr.p_proc; 3427 3428 knlist_remove(&p->p_klist, kn, 0); 3429} 3430 3431/* 3432 * signal knotes are shared with proc knotes, so we apply a mask to 3433 * the hint in order to differentiate them from process hints. This 3434 * could be avoided by using a signal-specific knote list, but probably 3435 * isn't worth the trouble. 3436 */ 3437static int 3438filt_signal(struct knote *kn, long hint) 3439{ 3440 3441 if (hint & NOTE_SIGNAL) { 3442 hint &= ~NOTE_SIGNAL; 3443 3444 if (kn->kn_id == hint) 3445 kn->kn_data++; 3446 } 3447 return (kn->kn_data != 0); 3448} 3449 3450struct sigacts * 3451sigacts_alloc(void) 3452{ 3453 struct sigacts *ps; 3454 3455 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3456 ps->ps_refcnt = 1; 3457 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3458 return (ps); 3459} 3460 3461void 3462sigacts_free(struct sigacts *ps) 3463{ 3464 3465 if (refcount_release(&ps->ps_refcnt) == 0) 3466 return; 3467 mtx_destroy(&ps->ps_mtx); 3468 free(ps, M_SUBPROC); 3469} 3470 3471struct sigacts * 3472sigacts_hold(struct sigacts *ps) 3473{ 3474 3475 refcount_acquire(&ps->ps_refcnt); 3476 return (ps); 3477} 3478 3479void 3480sigacts_copy(struct sigacts *dest, struct sigacts *src) 3481{ 3482 3483 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3484 mtx_lock(&src->ps_mtx); 3485 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3486 mtx_unlock(&src->ps_mtx); 3487} 3488 3489int 3490sigacts_shared(struct sigacts *ps) 3491{ 3492 3493 return (ps->ps_refcnt > 1); 3494} 3495