kern_sig.c revision 304017
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 304017 2016-08-12 19:43:06Z jhb $"); 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/capsicum.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, , , signal__send, 98 "struct thread *", "struct proc *", "int"); 99SDT_PROBE_DEFINE2(proc, , , signal__clear, 100 "int", "ksiginfo_t *"); 101SDT_PROBE_DEFINE3(proc, , , 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_handler != SIG_DFL && 662 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 663 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 664 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 665 return (EINVAL); 666 667 PROC_LOCK(p); 668 ps = p->p_sigacts; 669 mtx_lock(&ps->ps_mtx); 670 if (oact) { 671 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 672 oact->sa_flags = 0; 673 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 674 oact->sa_flags |= SA_ONSTACK; 675 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 676 oact->sa_flags |= SA_RESTART; 677 if (SIGISMEMBER(ps->ps_sigreset, sig)) 678 oact->sa_flags |= SA_RESETHAND; 679 if (SIGISMEMBER(ps->ps_signodefer, sig)) 680 oact->sa_flags |= SA_NODEFER; 681 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 682 oact->sa_flags |= SA_SIGINFO; 683 oact->sa_sigaction = 684 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 685 } else 686 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 687 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 688 oact->sa_flags |= SA_NOCLDSTOP; 689 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 690 oact->sa_flags |= SA_NOCLDWAIT; 691 } 692 if (act) { 693 if ((sig == SIGKILL || sig == SIGSTOP) && 694 act->sa_handler != SIG_DFL) { 695 mtx_unlock(&ps->ps_mtx); 696 PROC_UNLOCK(p); 697 return (EINVAL); 698 } 699 700 /* 701 * Change setting atomically. 702 */ 703 704 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 705 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 706 if (sigact_flag_test(act, SA_SIGINFO)) { 707 ps->ps_sigact[_SIG_IDX(sig)] = 708 (__sighandler_t *)act->sa_sigaction; 709 SIGADDSET(ps->ps_siginfo, sig); 710 } else { 711 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 712 SIGDELSET(ps->ps_siginfo, sig); 713 } 714 if (!sigact_flag_test(act, SA_RESTART)) 715 SIGADDSET(ps->ps_sigintr, sig); 716 else 717 SIGDELSET(ps->ps_sigintr, sig); 718 if (sigact_flag_test(act, SA_ONSTACK)) 719 SIGADDSET(ps->ps_sigonstack, sig); 720 else 721 SIGDELSET(ps->ps_sigonstack, sig); 722 if (sigact_flag_test(act, SA_RESETHAND)) 723 SIGADDSET(ps->ps_sigreset, sig); 724 else 725 SIGDELSET(ps->ps_sigreset, sig); 726 if (sigact_flag_test(act, SA_NODEFER)) 727 SIGADDSET(ps->ps_signodefer, sig); 728 else 729 SIGDELSET(ps->ps_signodefer, sig); 730 if (sig == SIGCHLD) { 731 if (act->sa_flags & SA_NOCLDSTOP) 732 ps->ps_flag |= PS_NOCLDSTOP; 733 else 734 ps->ps_flag &= ~PS_NOCLDSTOP; 735 if (act->sa_flags & SA_NOCLDWAIT) { 736 /* 737 * Paranoia: since SA_NOCLDWAIT is implemented 738 * by reparenting the dying child to PID 1 (and 739 * trust it to reap the zombie), PID 1 itself 740 * is forbidden to set SA_NOCLDWAIT. 741 */ 742 if (p->p_pid == 1) 743 ps->ps_flag &= ~PS_NOCLDWAIT; 744 else 745 ps->ps_flag |= PS_NOCLDWAIT; 746 } else 747 ps->ps_flag &= ~PS_NOCLDWAIT; 748 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 749 ps->ps_flag |= PS_CLDSIGIGN; 750 else 751 ps->ps_flag &= ~PS_CLDSIGIGN; 752 } 753 /* 754 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 755 * and for signals set to SIG_DFL where the default is to 756 * ignore. However, don't put SIGCONT in ps_sigignore, as we 757 * have to restart the process. 758 */ 759 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 760 (sigprop(sig) & SA_IGNORE && 761 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 762 /* never to be seen again */ 763 sigqueue_delete_proc(p, sig); 764 if (sig != SIGCONT) 765 /* easier in psignal */ 766 SIGADDSET(ps->ps_sigignore, sig); 767 SIGDELSET(ps->ps_sigcatch, sig); 768 } else { 769 SIGDELSET(ps->ps_sigignore, sig); 770 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 771 SIGDELSET(ps->ps_sigcatch, sig); 772 else 773 SIGADDSET(ps->ps_sigcatch, sig); 774 } 775#ifdef COMPAT_FREEBSD4 776 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 777 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 778 (flags & KSA_FREEBSD4) == 0) 779 SIGDELSET(ps->ps_freebsd4, sig); 780 else 781 SIGADDSET(ps->ps_freebsd4, sig); 782#endif 783#ifdef COMPAT_43 784 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 785 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 786 (flags & KSA_OSIGSET) == 0) 787 SIGDELSET(ps->ps_osigset, sig); 788 else 789 SIGADDSET(ps->ps_osigset, sig); 790#endif 791 } 792 mtx_unlock(&ps->ps_mtx); 793 PROC_UNLOCK(p); 794 return (0); 795} 796 797#ifndef _SYS_SYSPROTO_H_ 798struct sigaction_args { 799 int sig; 800 struct sigaction *act; 801 struct sigaction *oact; 802}; 803#endif 804int 805sys_sigaction(td, uap) 806 struct thread *td; 807 register struct sigaction_args *uap; 808{ 809 struct sigaction act, oact; 810 register struct sigaction *actp, *oactp; 811 int error; 812 813 actp = (uap->act != NULL) ? &act : NULL; 814 oactp = (uap->oact != NULL) ? &oact : NULL; 815 if (actp) { 816 error = copyin(uap->act, actp, sizeof(act)); 817 if (error) 818 return (error); 819 } 820 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 821 if (oactp && !error) 822 error = copyout(oactp, uap->oact, sizeof(oact)); 823 return (error); 824} 825 826#ifdef COMPAT_FREEBSD4 827#ifndef _SYS_SYSPROTO_H_ 828struct freebsd4_sigaction_args { 829 int sig; 830 struct sigaction *act; 831 struct sigaction *oact; 832}; 833#endif 834int 835freebsd4_sigaction(td, uap) 836 struct thread *td; 837 register struct freebsd4_sigaction_args *uap; 838{ 839 struct sigaction act, oact; 840 register struct sigaction *actp, *oactp; 841 int error; 842 843 844 actp = (uap->act != NULL) ? &act : NULL; 845 oactp = (uap->oact != NULL) ? &oact : NULL; 846 if (actp) { 847 error = copyin(uap->act, actp, sizeof(act)); 848 if (error) 849 return (error); 850 } 851 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 852 if (oactp && !error) 853 error = copyout(oactp, uap->oact, sizeof(oact)); 854 return (error); 855} 856#endif /* COMAPT_FREEBSD4 */ 857 858#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 859#ifndef _SYS_SYSPROTO_H_ 860struct osigaction_args { 861 int signum; 862 struct osigaction *nsa; 863 struct osigaction *osa; 864}; 865#endif 866int 867osigaction(td, uap) 868 struct thread *td; 869 register struct osigaction_args *uap; 870{ 871 struct osigaction sa; 872 struct sigaction nsa, osa; 873 register struct sigaction *nsap, *osap; 874 int error; 875 876 if (uap->signum <= 0 || uap->signum >= ONSIG) 877 return (EINVAL); 878 879 nsap = (uap->nsa != NULL) ? &nsa : NULL; 880 osap = (uap->osa != NULL) ? &osa : NULL; 881 882 if (nsap) { 883 error = copyin(uap->nsa, &sa, sizeof(sa)); 884 if (error) 885 return (error); 886 nsap->sa_handler = sa.sa_handler; 887 nsap->sa_flags = sa.sa_flags; 888 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 889 } 890 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 891 if (osap && !error) { 892 sa.sa_handler = osap->sa_handler; 893 sa.sa_flags = osap->sa_flags; 894 SIG2OSIG(osap->sa_mask, sa.sa_mask); 895 error = copyout(&sa, uap->osa, sizeof(sa)); 896 } 897 return (error); 898} 899 900#if !defined(__i386__) 901/* Avoid replicating the same stub everywhere */ 902int 903osigreturn(td, uap) 904 struct thread *td; 905 struct osigreturn_args *uap; 906{ 907 908 return (nosys(td, (struct nosys_args *)uap)); 909} 910#endif 911#endif /* COMPAT_43 */ 912 913/* 914 * Initialize signal state for process 0; 915 * set to ignore signals that are ignored by default. 916 */ 917void 918siginit(p) 919 struct proc *p; 920{ 921 register int i; 922 struct sigacts *ps; 923 924 PROC_LOCK(p); 925 ps = p->p_sigacts; 926 mtx_lock(&ps->ps_mtx); 927 for (i = 1; i <= NSIG; i++) { 928 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 929 SIGADDSET(ps->ps_sigignore, i); 930 } 931 } 932 mtx_unlock(&ps->ps_mtx); 933 PROC_UNLOCK(p); 934} 935 936/* 937 * Reset specified signal to the default disposition. 938 */ 939static void 940sigdflt(struct sigacts *ps, int sig) 941{ 942 943 mtx_assert(&ps->ps_mtx, MA_OWNED); 944 SIGDELSET(ps->ps_sigcatch, sig); 945 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 946 SIGADDSET(ps->ps_sigignore, sig); 947 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 948 SIGDELSET(ps->ps_siginfo, sig); 949} 950 951/* 952 * Reset signals for an exec of the specified process. 953 */ 954void 955execsigs(struct proc *p) 956{ 957 struct sigacts *ps; 958 int sig; 959 struct thread *td; 960 961 /* 962 * Reset caught signals. Held signals remain held 963 * through td_sigmask (unless they were caught, 964 * and are now ignored by default). 965 */ 966 PROC_LOCK_ASSERT(p, MA_OWNED); 967 td = FIRST_THREAD_IN_PROC(p); 968 ps = p->p_sigacts; 969 mtx_lock(&ps->ps_mtx); 970 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 971 sig = sig_ffs(&ps->ps_sigcatch); 972 sigdflt(ps, sig); 973 if ((sigprop(sig) & SA_IGNORE) != 0) 974 sigqueue_delete_proc(p, sig); 975 } 976 /* 977 * Reset stack state to the user stack. 978 * Clear set of signals caught on the signal stack. 979 */ 980 td->td_sigstk.ss_flags = SS_DISABLE; 981 td->td_sigstk.ss_size = 0; 982 td->td_sigstk.ss_sp = 0; 983 td->td_pflags &= ~TDP_ALTSTACK; 984 /* 985 * Reset no zombies if child dies flag as Solaris does. 986 */ 987 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 988 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 989 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 990 mtx_unlock(&ps->ps_mtx); 991} 992 993/* 994 * kern_sigprocmask() 995 * 996 * Manipulate signal mask. 997 */ 998int 999kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1000 int flags) 1001{ 1002 sigset_t new_block, oset1; 1003 struct proc *p; 1004 int error; 1005 1006 p = td->td_proc; 1007 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1008 PROC_LOCK_ASSERT(p, MA_OWNED); 1009 else 1010 PROC_LOCK(p); 1011 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1012 ? MA_OWNED : MA_NOTOWNED); 1013 if (oset != NULL) 1014 *oset = td->td_sigmask; 1015 1016 error = 0; 1017 if (set != NULL) { 1018 switch (how) { 1019 case SIG_BLOCK: 1020 SIG_CANTMASK(*set); 1021 oset1 = td->td_sigmask; 1022 SIGSETOR(td->td_sigmask, *set); 1023 new_block = td->td_sigmask; 1024 SIGSETNAND(new_block, oset1); 1025 break; 1026 case SIG_UNBLOCK: 1027 SIGSETNAND(td->td_sigmask, *set); 1028 signotify(td); 1029 goto out; 1030 case SIG_SETMASK: 1031 SIG_CANTMASK(*set); 1032 oset1 = td->td_sigmask; 1033 if (flags & SIGPROCMASK_OLD) 1034 SIGSETLO(td->td_sigmask, *set); 1035 else 1036 td->td_sigmask = *set; 1037 new_block = td->td_sigmask; 1038 SIGSETNAND(new_block, oset1); 1039 signotify(td); 1040 break; 1041 default: 1042 error = EINVAL; 1043 goto out; 1044 } 1045 1046 /* 1047 * The new_block set contains signals that were not previously 1048 * blocked, but are blocked now. 1049 * 1050 * In case we block any signal that was not previously blocked 1051 * for td, and process has the signal pending, try to schedule 1052 * signal delivery to some thread that does not block the 1053 * signal, possibly waking it up. 1054 */ 1055 if (p->p_numthreads != 1) 1056 reschedule_signals(p, new_block, flags); 1057 } 1058 1059out: 1060 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1061 PROC_UNLOCK(p); 1062 return (error); 1063} 1064 1065#ifndef _SYS_SYSPROTO_H_ 1066struct sigprocmask_args { 1067 int how; 1068 const sigset_t *set; 1069 sigset_t *oset; 1070}; 1071#endif 1072int 1073sys_sigprocmask(td, uap) 1074 register struct thread *td; 1075 struct sigprocmask_args *uap; 1076{ 1077 sigset_t set, oset; 1078 sigset_t *setp, *osetp; 1079 int error; 1080 1081 setp = (uap->set != NULL) ? &set : NULL; 1082 osetp = (uap->oset != NULL) ? &oset : NULL; 1083 if (setp) { 1084 error = copyin(uap->set, setp, sizeof(set)); 1085 if (error) 1086 return (error); 1087 } 1088 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1089 if (osetp && !error) { 1090 error = copyout(osetp, uap->oset, sizeof(oset)); 1091 } 1092 return (error); 1093} 1094 1095#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1096#ifndef _SYS_SYSPROTO_H_ 1097struct osigprocmask_args { 1098 int how; 1099 osigset_t mask; 1100}; 1101#endif 1102int 1103osigprocmask(td, uap) 1104 register struct thread *td; 1105 struct osigprocmask_args *uap; 1106{ 1107 sigset_t set, oset; 1108 int error; 1109 1110 OSIG2SIG(uap->mask, set); 1111 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1112 SIG2OSIG(oset, td->td_retval[0]); 1113 return (error); 1114} 1115#endif /* COMPAT_43 */ 1116 1117int 1118sys_sigwait(struct thread *td, struct sigwait_args *uap) 1119{ 1120 ksiginfo_t ksi; 1121 sigset_t set; 1122 int error; 1123 1124 error = copyin(uap->set, &set, sizeof(set)); 1125 if (error) { 1126 td->td_retval[0] = error; 1127 return (0); 1128 } 1129 1130 error = kern_sigtimedwait(td, set, &ksi, NULL); 1131 if (error) { 1132 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1133 error = ERESTART; 1134 if (error == ERESTART) 1135 return (error); 1136 td->td_retval[0] = error; 1137 return (0); 1138 } 1139 1140 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1141 td->td_retval[0] = error; 1142 return (0); 1143} 1144 1145int 1146sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1147{ 1148 struct timespec ts; 1149 struct timespec *timeout; 1150 sigset_t set; 1151 ksiginfo_t ksi; 1152 int error; 1153 1154 if (uap->timeout) { 1155 error = copyin(uap->timeout, &ts, sizeof(ts)); 1156 if (error) 1157 return (error); 1158 1159 timeout = &ts; 1160 } else 1161 timeout = NULL; 1162 1163 error = copyin(uap->set, &set, sizeof(set)); 1164 if (error) 1165 return (error); 1166 1167 error = kern_sigtimedwait(td, set, &ksi, timeout); 1168 if (error) 1169 return (error); 1170 1171 if (uap->info) 1172 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1173 1174 if (error == 0) 1175 td->td_retval[0] = ksi.ksi_signo; 1176 return (error); 1177} 1178 1179int 1180sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1181{ 1182 ksiginfo_t ksi; 1183 sigset_t set; 1184 int error; 1185 1186 error = copyin(uap->set, &set, sizeof(set)); 1187 if (error) 1188 return (error); 1189 1190 error = kern_sigtimedwait(td, set, &ksi, NULL); 1191 if (error) 1192 return (error); 1193 1194 if (uap->info) 1195 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1196 1197 if (error == 0) 1198 td->td_retval[0] = ksi.ksi_signo; 1199 return (error); 1200} 1201 1202int 1203kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1204 struct timespec *timeout) 1205{ 1206 struct sigacts *ps; 1207 sigset_t saved_mask, new_block; 1208 struct proc *p; 1209 int error, sig, timo, timevalid = 0; 1210 struct timespec rts, ets, ts; 1211 struct timeval tv; 1212 1213 p = td->td_proc; 1214 error = 0; 1215 ets.tv_sec = 0; 1216 ets.tv_nsec = 0; 1217 1218 if (timeout != NULL) { 1219 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1220 timevalid = 1; 1221 getnanouptime(&rts); 1222 ets = rts; 1223 timespecadd(&ets, timeout); 1224 } 1225 } 1226 ksiginfo_init(ksi); 1227 /* Some signals can not be waited for. */ 1228 SIG_CANTMASK(waitset); 1229 ps = p->p_sigacts; 1230 PROC_LOCK(p); 1231 saved_mask = td->td_sigmask; 1232 SIGSETNAND(td->td_sigmask, waitset); 1233 for (;;) { 1234 mtx_lock(&ps->ps_mtx); 1235 sig = cursig(td); 1236 mtx_unlock(&ps->ps_mtx); 1237 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1238 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1239 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1240 error = 0; 1241 break; 1242 } 1243 } 1244 1245 if (error != 0) 1246 break; 1247 1248 /* 1249 * POSIX says this must be checked after looking for pending 1250 * signals. 1251 */ 1252 if (timeout != NULL) { 1253 if (!timevalid) { 1254 error = EINVAL; 1255 break; 1256 } 1257 getnanouptime(&rts); 1258 if (timespeccmp(&rts, &ets, >=)) { 1259 error = EAGAIN; 1260 break; 1261 } 1262 ts = ets; 1263 timespecsub(&ts, &rts); 1264 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1265 timo = tvtohz(&tv); 1266 } else { 1267 timo = 0; 1268 } 1269 1270 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1271 1272 if (timeout != NULL) { 1273 if (error == ERESTART) { 1274 /* Timeout can not be restarted. */ 1275 error = EINTR; 1276 } else if (error == EAGAIN) { 1277 /* We will calculate timeout by ourself. */ 1278 error = 0; 1279 } 1280 } 1281 } 1282 1283 new_block = saved_mask; 1284 SIGSETNAND(new_block, td->td_sigmask); 1285 td->td_sigmask = saved_mask; 1286 /* 1287 * Fewer signals can be delivered to us, reschedule signal 1288 * notification. 1289 */ 1290 if (p->p_numthreads != 1) 1291 reschedule_signals(p, new_block, 0); 1292 1293 if (error == 0) { 1294 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1295 1296 if (ksi->ksi_code == SI_TIMER) 1297 itimer_accept(p, ksi->ksi_timerid, ksi); 1298 1299#ifdef KTRACE 1300 if (KTRPOINT(td, KTR_PSIG)) { 1301 sig_t action; 1302 1303 mtx_lock(&ps->ps_mtx); 1304 action = ps->ps_sigact[_SIG_IDX(sig)]; 1305 mtx_unlock(&ps->ps_mtx); 1306 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1307 } 1308#endif 1309 if (sig == SIGKILL) 1310 sigexit(td, sig); 1311 } 1312 PROC_UNLOCK(p); 1313 return (error); 1314} 1315 1316#ifndef _SYS_SYSPROTO_H_ 1317struct sigpending_args { 1318 sigset_t *set; 1319}; 1320#endif 1321int 1322sys_sigpending(td, uap) 1323 struct thread *td; 1324 struct sigpending_args *uap; 1325{ 1326 struct proc *p = td->td_proc; 1327 sigset_t pending; 1328 1329 PROC_LOCK(p); 1330 pending = p->p_sigqueue.sq_signals; 1331 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1332 PROC_UNLOCK(p); 1333 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1334} 1335 1336#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1337#ifndef _SYS_SYSPROTO_H_ 1338struct osigpending_args { 1339 int dummy; 1340}; 1341#endif 1342int 1343osigpending(td, uap) 1344 struct thread *td; 1345 struct osigpending_args *uap; 1346{ 1347 struct proc *p = td->td_proc; 1348 sigset_t pending; 1349 1350 PROC_LOCK(p); 1351 pending = p->p_sigqueue.sq_signals; 1352 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1353 PROC_UNLOCK(p); 1354 SIG2OSIG(pending, td->td_retval[0]); 1355 return (0); 1356} 1357#endif /* COMPAT_43 */ 1358 1359#if defined(COMPAT_43) 1360/* 1361 * Generalized interface signal handler, 4.3-compatible. 1362 */ 1363#ifndef _SYS_SYSPROTO_H_ 1364struct osigvec_args { 1365 int signum; 1366 struct sigvec *nsv; 1367 struct sigvec *osv; 1368}; 1369#endif 1370/* ARGSUSED */ 1371int 1372osigvec(td, uap) 1373 struct thread *td; 1374 register struct osigvec_args *uap; 1375{ 1376 struct sigvec vec; 1377 struct sigaction nsa, osa; 1378 register struct sigaction *nsap, *osap; 1379 int error; 1380 1381 if (uap->signum <= 0 || uap->signum >= ONSIG) 1382 return (EINVAL); 1383 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1384 osap = (uap->osv != NULL) ? &osa : NULL; 1385 if (nsap) { 1386 error = copyin(uap->nsv, &vec, sizeof(vec)); 1387 if (error) 1388 return (error); 1389 nsap->sa_handler = vec.sv_handler; 1390 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1391 nsap->sa_flags = vec.sv_flags; 1392 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1393 } 1394 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1395 if (osap && !error) { 1396 vec.sv_handler = osap->sa_handler; 1397 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1398 vec.sv_flags = osap->sa_flags; 1399 vec.sv_flags &= ~SA_NOCLDWAIT; 1400 vec.sv_flags ^= SA_RESTART; 1401 error = copyout(&vec, uap->osv, sizeof(vec)); 1402 } 1403 return (error); 1404} 1405 1406#ifndef _SYS_SYSPROTO_H_ 1407struct osigblock_args { 1408 int mask; 1409}; 1410#endif 1411int 1412osigblock(td, uap) 1413 register struct thread *td; 1414 struct osigblock_args *uap; 1415{ 1416 sigset_t set, oset; 1417 1418 OSIG2SIG(uap->mask, set); 1419 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1420 SIG2OSIG(oset, td->td_retval[0]); 1421 return (0); 1422} 1423 1424#ifndef _SYS_SYSPROTO_H_ 1425struct osigsetmask_args { 1426 int mask; 1427}; 1428#endif 1429int 1430osigsetmask(td, uap) 1431 struct thread *td; 1432 struct osigsetmask_args *uap; 1433{ 1434 sigset_t set, oset; 1435 1436 OSIG2SIG(uap->mask, set); 1437 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1438 SIG2OSIG(oset, td->td_retval[0]); 1439 return (0); 1440} 1441#endif /* COMPAT_43 */ 1442 1443/* 1444 * Suspend calling thread until signal, providing mask to be set in the 1445 * meantime. 1446 */ 1447#ifndef _SYS_SYSPROTO_H_ 1448struct sigsuspend_args { 1449 const sigset_t *sigmask; 1450}; 1451#endif 1452/* ARGSUSED */ 1453int 1454sys_sigsuspend(td, uap) 1455 struct thread *td; 1456 struct sigsuspend_args *uap; 1457{ 1458 sigset_t mask; 1459 int error; 1460 1461 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1462 if (error) 1463 return (error); 1464 return (kern_sigsuspend(td, mask)); 1465} 1466 1467int 1468kern_sigsuspend(struct thread *td, sigset_t mask) 1469{ 1470 struct proc *p = td->td_proc; 1471 int has_sig, sig; 1472 1473 /* 1474 * When returning from sigsuspend, we want 1475 * the old mask to be restored after the 1476 * signal handler has finished. Thus, we 1477 * save it here and mark the sigacts structure 1478 * to indicate this. 1479 */ 1480 PROC_LOCK(p); 1481 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1482 SIGPROCMASK_PROC_LOCKED); 1483 td->td_pflags |= TDP_OLDMASK; 1484 1485 /* 1486 * Process signals now. Otherwise, we can get spurious wakeup 1487 * due to signal entered process queue, but delivered to other 1488 * thread. But sigsuspend should return only on signal 1489 * delivery. 1490 */ 1491 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1492 for (has_sig = 0; !has_sig;) { 1493 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1494 0) == 0) 1495 /* void */; 1496 thread_suspend_check(0); 1497 mtx_lock(&p->p_sigacts->ps_mtx); 1498 while ((sig = cursig(td)) != 0) 1499 has_sig += postsig(sig); 1500 mtx_unlock(&p->p_sigacts->ps_mtx); 1501 } 1502 PROC_UNLOCK(p); 1503 td->td_errno = EINTR; 1504 td->td_pflags |= TDP_NERRNO; 1505 return (EJUSTRETURN); 1506} 1507 1508#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1509/* 1510 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1511 * convention: libc stub passes mask, not pointer, to save a copyin. 1512 */ 1513#ifndef _SYS_SYSPROTO_H_ 1514struct osigsuspend_args { 1515 osigset_t mask; 1516}; 1517#endif 1518/* ARGSUSED */ 1519int 1520osigsuspend(td, uap) 1521 struct thread *td; 1522 struct osigsuspend_args *uap; 1523{ 1524 sigset_t mask; 1525 1526 OSIG2SIG(uap->mask, mask); 1527 return (kern_sigsuspend(td, mask)); 1528} 1529#endif /* COMPAT_43 */ 1530 1531#if defined(COMPAT_43) 1532#ifndef _SYS_SYSPROTO_H_ 1533struct osigstack_args { 1534 struct sigstack *nss; 1535 struct sigstack *oss; 1536}; 1537#endif 1538/* ARGSUSED */ 1539int 1540osigstack(td, uap) 1541 struct thread *td; 1542 register struct osigstack_args *uap; 1543{ 1544 struct sigstack nss, oss; 1545 int error = 0; 1546 1547 if (uap->nss != NULL) { 1548 error = copyin(uap->nss, &nss, sizeof(nss)); 1549 if (error) 1550 return (error); 1551 } 1552 oss.ss_sp = td->td_sigstk.ss_sp; 1553 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1554 if (uap->nss != NULL) { 1555 td->td_sigstk.ss_sp = nss.ss_sp; 1556 td->td_sigstk.ss_size = 0; 1557 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1558 td->td_pflags |= TDP_ALTSTACK; 1559 } 1560 if (uap->oss != NULL) 1561 error = copyout(&oss, uap->oss, sizeof(oss)); 1562 1563 return (error); 1564} 1565#endif /* COMPAT_43 */ 1566 1567#ifndef _SYS_SYSPROTO_H_ 1568struct sigaltstack_args { 1569 stack_t *ss; 1570 stack_t *oss; 1571}; 1572#endif 1573/* ARGSUSED */ 1574int 1575sys_sigaltstack(td, uap) 1576 struct thread *td; 1577 register struct sigaltstack_args *uap; 1578{ 1579 stack_t ss, oss; 1580 int error; 1581 1582 if (uap->ss != NULL) { 1583 error = copyin(uap->ss, &ss, sizeof(ss)); 1584 if (error) 1585 return (error); 1586 } 1587 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1588 (uap->oss != NULL) ? &oss : NULL); 1589 if (error) 1590 return (error); 1591 if (uap->oss != NULL) 1592 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1593 return (error); 1594} 1595 1596int 1597kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1598{ 1599 struct proc *p = td->td_proc; 1600 int oonstack; 1601 1602 oonstack = sigonstack(cpu_getstack(td)); 1603 1604 if (oss != NULL) { 1605 *oss = td->td_sigstk; 1606 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1607 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1608 } 1609 1610 if (ss != NULL) { 1611 if (oonstack) 1612 return (EPERM); 1613 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1614 return (EINVAL); 1615 if (!(ss->ss_flags & SS_DISABLE)) { 1616 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1617 return (ENOMEM); 1618 1619 td->td_sigstk = *ss; 1620 td->td_pflags |= TDP_ALTSTACK; 1621 } else { 1622 td->td_pflags &= ~TDP_ALTSTACK; 1623 } 1624 } 1625 return (0); 1626} 1627 1628/* 1629 * Common code for kill process group/broadcast kill. 1630 * cp is calling process. 1631 */ 1632static int 1633killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1634{ 1635 struct proc *p; 1636 struct pgrp *pgrp; 1637 int err; 1638 int ret; 1639 1640 ret = ESRCH; 1641 if (all) { 1642 /* 1643 * broadcast 1644 */ 1645 sx_slock(&allproc_lock); 1646 FOREACH_PROC_IN_SYSTEM(p) { 1647 PROC_LOCK(p); 1648 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1649 p == td->td_proc || p->p_state == PRS_NEW) { 1650 PROC_UNLOCK(p); 1651 continue; 1652 } 1653 err = p_cansignal(td, p, sig); 1654 if (err == 0) { 1655 if (sig) 1656 pksignal(p, sig, ksi); 1657 ret = err; 1658 } 1659 else if (ret == ESRCH) 1660 ret = err; 1661 PROC_UNLOCK(p); 1662 } 1663 sx_sunlock(&allproc_lock); 1664 } else { 1665 sx_slock(&proctree_lock); 1666 if (pgid == 0) { 1667 /* 1668 * zero pgid means send to my process group. 1669 */ 1670 pgrp = td->td_proc->p_pgrp; 1671 PGRP_LOCK(pgrp); 1672 } else { 1673 pgrp = pgfind(pgid); 1674 if (pgrp == NULL) { 1675 sx_sunlock(&proctree_lock); 1676 return (ESRCH); 1677 } 1678 } 1679 sx_sunlock(&proctree_lock); 1680 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1681 PROC_LOCK(p); 1682 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1683 p->p_state == PRS_NEW) { 1684 PROC_UNLOCK(p); 1685 continue; 1686 } 1687 err = p_cansignal(td, p, sig); 1688 if (err == 0) { 1689 if (sig) 1690 pksignal(p, sig, ksi); 1691 ret = err; 1692 } 1693 else if (ret == ESRCH) 1694 ret = err; 1695 PROC_UNLOCK(p); 1696 } 1697 PGRP_UNLOCK(pgrp); 1698 } 1699 return (ret); 1700} 1701 1702#ifndef _SYS_SYSPROTO_H_ 1703struct kill_args { 1704 int pid; 1705 int signum; 1706}; 1707#endif 1708/* ARGSUSED */ 1709int 1710sys_kill(struct thread *td, struct kill_args *uap) 1711{ 1712 ksiginfo_t ksi; 1713 struct proc *p; 1714 int error; 1715 1716 /* 1717 * A process in capability mode can send signals only to himself. 1718 * The main rationale behind this is that abort(3) is implemented as 1719 * kill(getpid(), SIGABRT). 1720 */ 1721 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1722 return (ECAPMODE); 1723 1724 AUDIT_ARG_SIGNUM(uap->signum); 1725 AUDIT_ARG_PID(uap->pid); 1726 if ((u_int)uap->signum > _SIG_MAXSIG) 1727 return (EINVAL); 1728 1729 ksiginfo_init(&ksi); 1730 ksi.ksi_signo = uap->signum; 1731 ksi.ksi_code = SI_USER; 1732 ksi.ksi_pid = td->td_proc->p_pid; 1733 ksi.ksi_uid = td->td_ucred->cr_ruid; 1734 1735 if (uap->pid > 0) { 1736 /* kill single process */ 1737 if ((p = pfind(uap->pid)) == NULL) { 1738 if ((p = zpfind(uap->pid)) == NULL) 1739 return (ESRCH); 1740 } 1741 AUDIT_ARG_PROCESS(p); 1742 error = p_cansignal(td, p, uap->signum); 1743 if (error == 0 && uap->signum) 1744 pksignal(p, uap->signum, &ksi); 1745 PROC_UNLOCK(p); 1746 return (error); 1747 } 1748 switch (uap->pid) { 1749 case -1: /* broadcast signal */ 1750 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1751 case 0: /* signal own process group */ 1752 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1753 default: /* negative explicit process group */ 1754 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1755 } 1756 /* NOTREACHED */ 1757} 1758 1759int 1760sys_pdkill(td, uap) 1761 struct thread *td; 1762 struct pdkill_args *uap; 1763{ 1764#ifdef PROCDESC 1765 struct proc *p; 1766 cap_rights_t rights; 1767 int error; 1768 1769 AUDIT_ARG_SIGNUM(uap->signum); 1770 AUDIT_ARG_FD(uap->fd); 1771 if ((u_int)uap->signum > _SIG_MAXSIG) 1772 return (EINVAL); 1773 1774 error = procdesc_find(td, uap->fd, 1775 cap_rights_init(&rights, CAP_PDKILL), &p); 1776 if (error) 1777 return (error); 1778 AUDIT_ARG_PROCESS(p); 1779 error = p_cansignal(td, p, uap->signum); 1780 if (error == 0 && uap->signum) 1781 kern_psignal(p, uap->signum); 1782 PROC_UNLOCK(p); 1783 return (error); 1784#else 1785 return (ENOSYS); 1786#endif 1787} 1788 1789#if defined(COMPAT_43) 1790#ifndef _SYS_SYSPROTO_H_ 1791struct okillpg_args { 1792 int pgid; 1793 int signum; 1794}; 1795#endif 1796/* ARGSUSED */ 1797int 1798okillpg(struct thread *td, struct okillpg_args *uap) 1799{ 1800 ksiginfo_t ksi; 1801 1802 AUDIT_ARG_SIGNUM(uap->signum); 1803 AUDIT_ARG_PID(uap->pgid); 1804 if ((u_int)uap->signum > _SIG_MAXSIG) 1805 return (EINVAL); 1806 1807 ksiginfo_init(&ksi); 1808 ksi.ksi_signo = uap->signum; 1809 ksi.ksi_code = SI_USER; 1810 ksi.ksi_pid = td->td_proc->p_pid; 1811 ksi.ksi_uid = td->td_ucred->cr_ruid; 1812 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1813} 1814#endif /* COMPAT_43 */ 1815 1816#ifndef _SYS_SYSPROTO_H_ 1817struct sigqueue_args { 1818 pid_t pid; 1819 int signum; 1820 /* union sigval */ void *value; 1821}; 1822#endif 1823int 1824sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1825{ 1826 ksiginfo_t ksi; 1827 struct proc *p; 1828 int error; 1829 1830 if ((u_int)uap->signum > _SIG_MAXSIG) 1831 return (EINVAL); 1832 1833 /* 1834 * Specification says sigqueue can only send signal to 1835 * single process. 1836 */ 1837 if (uap->pid <= 0) 1838 return (EINVAL); 1839 1840 if ((p = pfind(uap->pid)) == NULL) { 1841 if ((p = zpfind(uap->pid)) == NULL) 1842 return (ESRCH); 1843 } 1844 error = p_cansignal(td, p, uap->signum); 1845 if (error == 0 && uap->signum != 0) { 1846 ksiginfo_init(&ksi); 1847 ksi.ksi_flags = KSI_SIGQ; 1848 ksi.ksi_signo = uap->signum; 1849 ksi.ksi_code = SI_QUEUE; 1850 ksi.ksi_pid = td->td_proc->p_pid; 1851 ksi.ksi_uid = td->td_ucred->cr_ruid; 1852 ksi.ksi_value.sival_ptr = uap->value; 1853 error = pksignal(p, ksi.ksi_signo, &ksi); 1854 } 1855 PROC_UNLOCK(p); 1856 return (error); 1857} 1858 1859/* 1860 * Send a signal to a process group. 1861 */ 1862void 1863gsignal(int pgid, int sig, ksiginfo_t *ksi) 1864{ 1865 struct pgrp *pgrp; 1866 1867 if (pgid != 0) { 1868 sx_slock(&proctree_lock); 1869 pgrp = pgfind(pgid); 1870 sx_sunlock(&proctree_lock); 1871 if (pgrp != NULL) { 1872 pgsignal(pgrp, sig, 0, ksi); 1873 PGRP_UNLOCK(pgrp); 1874 } 1875 } 1876} 1877 1878/* 1879 * Send a signal to a process group. If checktty is 1, 1880 * limit to members which have a controlling terminal. 1881 */ 1882void 1883pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1884{ 1885 struct proc *p; 1886 1887 if (pgrp) { 1888 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1889 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1890 PROC_LOCK(p); 1891 if (p->p_state == PRS_NORMAL && 1892 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1893 pksignal(p, sig, ksi); 1894 PROC_UNLOCK(p); 1895 } 1896 } 1897} 1898 1899 1900/* 1901 * Recalculate the signal mask and reset the signal disposition after 1902 * usermode frame for delivery is formed. Should be called after 1903 * mach-specific routine, because sysent->sv_sendsig() needs correct 1904 * ps_siginfo and signal mask. 1905 */ 1906static void 1907postsig_done(int sig, struct thread *td, struct sigacts *ps) 1908{ 1909 sigset_t mask; 1910 1911 mtx_assert(&ps->ps_mtx, MA_OWNED); 1912 td->td_ru.ru_nsignals++; 1913 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1914 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1915 SIGADDSET(mask, sig); 1916 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1917 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1918 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1919 sigdflt(ps, sig); 1920} 1921 1922 1923/* 1924 * Send a signal caused by a trap to the current thread. If it will be 1925 * caught immediately, deliver it with correct code. Otherwise, post it 1926 * normally. 1927 */ 1928void 1929trapsignal(struct thread *td, ksiginfo_t *ksi) 1930{ 1931 struct sigacts *ps; 1932 struct proc *p; 1933 int sig; 1934 int code; 1935 1936 p = td->td_proc; 1937 sig = ksi->ksi_signo; 1938 code = ksi->ksi_code; 1939 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1940 1941 PROC_LOCK(p); 1942 ps = p->p_sigacts; 1943 mtx_lock(&ps->ps_mtx); 1944 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1945 !SIGISMEMBER(td->td_sigmask, sig)) { 1946#ifdef KTRACE 1947 if (KTRPOINT(curthread, KTR_PSIG)) 1948 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1949 &td->td_sigmask, code); 1950#endif 1951 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1952 ksi, &td->td_sigmask); 1953 postsig_done(sig, td, ps); 1954 mtx_unlock(&ps->ps_mtx); 1955 } else { 1956 /* 1957 * Avoid a possible infinite loop if the thread 1958 * masking the signal or process is ignoring the 1959 * signal. 1960 */ 1961 if (kern_forcesigexit && 1962 (SIGISMEMBER(td->td_sigmask, sig) || 1963 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1964 SIGDELSET(td->td_sigmask, sig); 1965 SIGDELSET(ps->ps_sigcatch, sig); 1966 SIGDELSET(ps->ps_sigignore, sig); 1967 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1968 } 1969 mtx_unlock(&ps->ps_mtx); 1970 p->p_code = code; /* XXX for core dump/debugger */ 1971 p->p_sig = sig; /* XXX to verify code */ 1972 tdsendsignal(p, td, sig, ksi); 1973 } 1974 PROC_UNLOCK(p); 1975} 1976 1977static struct thread * 1978sigtd(struct proc *p, int sig, int prop) 1979{ 1980 struct thread *td, *signal_td; 1981 1982 PROC_LOCK_ASSERT(p, MA_OWNED); 1983 1984 /* 1985 * Check if current thread can handle the signal without 1986 * switching context to another thread. 1987 */ 1988 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 1989 return (curthread); 1990 signal_td = NULL; 1991 FOREACH_THREAD_IN_PROC(p, td) { 1992 if (!SIGISMEMBER(td->td_sigmask, sig)) { 1993 signal_td = td; 1994 break; 1995 } 1996 } 1997 if (signal_td == NULL) 1998 signal_td = FIRST_THREAD_IN_PROC(p); 1999 return (signal_td); 2000} 2001 2002/* 2003 * Send the signal to the process. If the signal has an action, the action 2004 * is usually performed by the target process rather than the caller; we add 2005 * the signal to the set of pending signals for the process. 2006 * 2007 * Exceptions: 2008 * o When a stop signal is sent to a sleeping process that takes the 2009 * default action, the process is stopped without awakening it. 2010 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2011 * regardless of the signal action (eg, blocked or ignored). 2012 * 2013 * Other ignored signals are discarded immediately. 2014 * 2015 * NB: This function may be entered from the debugger via the "kill" DDB 2016 * command. There is little that can be done to mitigate the possibly messy 2017 * side effects of this unwise possibility. 2018 */ 2019void 2020kern_psignal(struct proc *p, int sig) 2021{ 2022 ksiginfo_t ksi; 2023 2024 ksiginfo_init(&ksi); 2025 ksi.ksi_signo = sig; 2026 ksi.ksi_code = SI_KERNEL; 2027 (void) tdsendsignal(p, NULL, sig, &ksi); 2028} 2029 2030int 2031pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2032{ 2033 2034 return (tdsendsignal(p, NULL, sig, ksi)); 2035} 2036 2037/* Utility function for finding a thread to send signal event to. */ 2038int 2039sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2040{ 2041 struct thread *td; 2042 2043 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2044 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2045 if (td == NULL) 2046 return (ESRCH); 2047 *ttd = td; 2048 } else { 2049 *ttd = NULL; 2050 PROC_LOCK(p); 2051 } 2052 return (0); 2053} 2054 2055void 2056tdsignal(struct thread *td, int sig) 2057{ 2058 ksiginfo_t ksi; 2059 2060 ksiginfo_init(&ksi); 2061 ksi.ksi_signo = sig; 2062 ksi.ksi_code = SI_KERNEL; 2063 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2064} 2065 2066void 2067tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2068{ 2069 2070 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2071} 2072 2073int 2074tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2075{ 2076 sig_t action; 2077 sigqueue_t *sigqueue; 2078 int prop; 2079 struct sigacts *ps; 2080 int intrval; 2081 int ret = 0; 2082 int wakeup_swapper; 2083 2084 MPASS(td == NULL || p == td->td_proc); 2085 PROC_LOCK_ASSERT(p, MA_OWNED); 2086 2087 if (!_SIG_VALID(sig)) 2088 panic("%s(): invalid signal %d", __func__, sig); 2089 2090 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2091 2092 /* 2093 * IEEE Std 1003.1-2001: return success when killing a zombie. 2094 */ 2095 if (p->p_state == PRS_ZOMBIE) { 2096 if (ksi && (ksi->ksi_flags & KSI_INS)) 2097 ksiginfo_tryfree(ksi); 2098 return (ret); 2099 } 2100 2101 ps = p->p_sigacts; 2102 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2103 prop = sigprop(sig); 2104 2105 if (td == NULL) { 2106 td = sigtd(p, sig, prop); 2107 sigqueue = &p->p_sigqueue; 2108 } else 2109 sigqueue = &td->td_sigqueue; 2110 2111 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2112 2113 /* 2114 * If the signal is being ignored, 2115 * then we forget about it immediately. 2116 * (Note: we don't set SIGCONT in ps_sigignore, 2117 * and if it is set to SIG_IGN, 2118 * action will be SIG_DFL here.) 2119 */ 2120 mtx_lock(&ps->ps_mtx); 2121 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2122 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2123 2124 mtx_unlock(&ps->ps_mtx); 2125 if (ksi && (ksi->ksi_flags & KSI_INS)) 2126 ksiginfo_tryfree(ksi); 2127 return (ret); 2128 } 2129 if (SIGISMEMBER(td->td_sigmask, sig)) 2130 action = SIG_HOLD; 2131 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2132 action = SIG_CATCH; 2133 else 2134 action = SIG_DFL; 2135 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2136 intrval = EINTR; 2137 else 2138 intrval = ERESTART; 2139 mtx_unlock(&ps->ps_mtx); 2140 2141 if (prop & SA_CONT) 2142 sigqueue_delete_stopmask_proc(p); 2143 else if (prop & SA_STOP) { 2144 /* 2145 * If sending a tty stop signal to a member of an orphaned 2146 * process group, discard the signal here if the action 2147 * is default; don't stop the process below if sleeping, 2148 * and don't clear any pending SIGCONT. 2149 */ 2150 if ((prop & SA_TTYSTOP) && 2151 (p->p_pgrp->pg_jobc == 0) && 2152 (action == SIG_DFL)) { 2153 if (ksi && (ksi->ksi_flags & KSI_INS)) 2154 ksiginfo_tryfree(ksi); 2155 return (ret); 2156 } 2157 sigqueue_delete_proc(p, SIGCONT); 2158 if (p->p_flag & P_CONTINUED) { 2159 p->p_flag &= ~P_CONTINUED; 2160 PROC_LOCK(p->p_pptr); 2161 sigqueue_take(p->p_ksi); 2162 PROC_UNLOCK(p->p_pptr); 2163 } 2164 } 2165 2166 ret = sigqueue_add(sigqueue, sig, ksi); 2167 if (ret != 0) 2168 return (ret); 2169 signotify(td); 2170 /* 2171 * Defer further processing for signals which are held, 2172 * except that stopped processes must be continued by SIGCONT. 2173 */ 2174 if (action == SIG_HOLD && 2175 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2176 return (ret); 2177 /* 2178 * SIGKILL: Remove procfs STOPEVENTs. 2179 */ 2180 if (sig == SIGKILL) { 2181 /* from procfs_ioctl.c: PIOCBIC */ 2182 p->p_stops = 0; 2183 /* from procfs_ioctl.c: PIOCCONT */ 2184 p->p_step = 0; 2185 wakeup(&p->p_step); 2186 } 2187 /* 2188 * Some signals have a process-wide effect and a per-thread 2189 * component. Most processing occurs when the process next 2190 * tries to cross the user boundary, however there are some 2191 * times when processing needs to be done immediately, such as 2192 * waking up threads so that they can cross the user boundary. 2193 * We try to do the per-process part here. 2194 */ 2195 if (P_SHOULDSTOP(p)) { 2196 KASSERT(!(p->p_flag & P_WEXIT), 2197 ("signal to stopped but exiting process")); 2198 if (sig == SIGKILL) { 2199 /* 2200 * If traced process is already stopped, 2201 * then no further action is necessary. 2202 */ 2203 if (p->p_flag & P_TRACED) 2204 goto out; 2205 /* 2206 * SIGKILL sets process running. 2207 * It will die elsewhere. 2208 * All threads must be restarted. 2209 */ 2210 p->p_flag &= ~P_STOPPED_SIG; 2211 goto runfast; 2212 } 2213 2214 if (prop & SA_CONT) { 2215 /* 2216 * If traced process is already stopped, 2217 * then no further action is necessary. 2218 */ 2219 if (p->p_flag & P_TRACED) 2220 goto out; 2221 /* 2222 * If SIGCONT is default (or ignored), we continue the 2223 * process but don't leave the signal in sigqueue as 2224 * it has no further action. If SIGCONT is held, we 2225 * continue the process and leave the signal in 2226 * sigqueue. If the process catches SIGCONT, let it 2227 * handle the signal itself. If it isn't waiting on 2228 * an event, it goes back to run state. 2229 * Otherwise, process goes back to sleep state. 2230 */ 2231 p->p_flag &= ~P_STOPPED_SIG; 2232 PROC_SLOCK(p); 2233 if (p->p_numthreads == p->p_suspcount) { 2234 PROC_SUNLOCK(p); 2235 p->p_flag |= P_CONTINUED; 2236 p->p_xstat = SIGCONT; 2237 PROC_LOCK(p->p_pptr); 2238 childproc_continued(p); 2239 PROC_UNLOCK(p->p_pptr); 2240 PROC_SLOCK(p); 2241 } 2242 if (action == SIG_DFL) { 2243 thread_unsuspend(p); 2244 PROC_SUNLOCK(p); 2245 sigqueue_delete(sigqueue, sig); 2246 goto out; 2247 } 2248 if (action == SIG_CATCH) { 2249 /* 2250 * The process wants to catch it so it needs 2251 * to run at least one thread, but which one? 2252 */ 2253 PROC_SUNLOCK(p); 2254 goto runfast; 2255 } 2256 /* 2257 * The signal is not ignored or caught. 2258 */ 2259 thread_unsuspend(p); 2260 PROC_SUNLOCK(p); 2261 goto out; 2262 } 2263 2264 if (prop & SA_STOP) { 2265 /* 2266 * If traced process is already stopped, 2267 * then no further action is necessary. 2268 */ 2269 if (p->p_flag & P_TRACED) 2270 goto out; 2271 /* 2272 * Already stopped, don't need to stop again 2273 * (If we did the shell could get confused). 2274 * Just make sure the signal STOP bit set. 2275 */ 2276 p->p_flag |= P_STOPPED_SIG; 2277 sigqueue_delete(sigqueue, sig); 2278 goto out; 2279 } 2280 2281 /* 2282 * All other kinds of signals: 2283 * If a thread is sleeping interruptibly, simulate a 2284 * wakeup so that when it is continued it will be made 2285 * runnable and can look at the signal. However, don't make 2286 * the PROCESS runnable, leave it stopped. 2287 * It may run a bit until it hits a thread_suspend_check(). 2288 */ 2289 wakeup_swapper = 0; 2290 PROC_SLOCK(p); 2291 thread_lock(td); 2292 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2293 wakeup_swapper = sleepq_abort(td, intrval); 2294 thread_unlock(td); 2295 PROC_SUNLOCK(p); 2296 if (wakeup_swapper) 2297 kick_proc0(); 2298 goto out; 2299 /* 2300 * Mutexes are short lived. Threads waiting on them will 2301 * hit thread_suspend_check() soon. 2302 */ 2303 } else if (p->p_state == PRS_NORMAL) { 2304 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2305 tdsigwakeup(td, sig, action, intrval); 2306 goto out; 2307 } 2308 2309 MPASS(action == SIG_DFL); 2310 2311 if (prop & SA_STOP) { 2312 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2313 goto out; 2314 p->p_flag |= P_STOPPED_SIG; 2315 p->p_xstat = sig; 2316 PROC_SLOCK(p); 2317 sig_suspend_threads(td, p, 1); 2318 if (p->p_numthreads == p->p_suspcount) { 2319 /* 2320 * only thread sending signal to another 2321 * process can reach here, if thread is sending 2322 * signal to its process, because thread does 2323 * not suspend itself here, p_numthreads 2324 * should never be equal to p_suspcount. 2325 */ 2326 thread_stopped(p); 2327 PROC_SUNLOCK(p); 2328 sigqueue_delete_proc(p, p->p_xstat); 2329 } else 2330 PROC_SUNLOCK(p); 2331 goto out; 2332 } 2333 } else { 2334 /* Not in "NORMAL" state. discard the signal. */ 2335 sigqueue_delete(sigqueue, sig); 2336 goto out; 2337 } 2338 2339 /* 2340 * The process is not stopped so we need to apply the signal to all the 2341 * running threads. 2342 */ 2343runfast: 2344 tdsigwakeup(td, sig, action, intrval); 2345 PROC_SLOCK(p); 2346 thread_unsuspend(p); 2347 PROC_SUNLOCK(p); 2348out: 2349 /* If we jump here, proc slock should not be owned. */ 2350 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2351 return (ret); 2352} 2353 2354/* 2355 * The force of a signal has been directed against a single 2356 * thread. We need to see what we can do about knocking it 2357 * out of any sleep it may be in etc. 2358 */ 2359static void 2360tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2361{ 2362 struct proc *p = td->td_proc; 2363 register int prop; 2364 int wakeup_swapper; 2365 2366 wakeup_swapper = 0; 2367 PROC_LOCK_ASSERT(p, MA_OWNED); 2368 prop = sigprop(sig); 2369 2370 PROC_SLOCK(p); 2371 thread_lock(td); 2372 /* 2373 * Bring the priority of a thread up if we want it to get 2374 * killed in this lifetime. Be careful to avoid bumping the 2375 * priority of the idle thread, since we still allow to signal 2376 * kernel processes. 2377 */ 2378 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2379 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2380 sched_prio(td, PUSER); 2381 if (TD_ON_SLEEPQ(td)) { 2382 /* 2383 * If thread is sleeping uninterruptibly 2384 * we can't interrupt the sleep... the signal will 2385 * be noticed when the process returns through 2386 * trap() or syscall(). 2387 */ 2388 if ((td->td_flags & TDF_SINTR) == 0) 2389 goto out; 2390 /* 2391 * If SIGCONT is default (or ignored) and process is 2392 * asleep, we are finished; the process should not 2393 * be awakened. 2394 */ 2395 if ((prop & SA_CONT) && action == SIG_DFL) { 2396 thread_unlock(td); 2397 PROC_SUNLOCK(p); 2398 sigqueue_delete(&p->p_sigqueue, sig); 2399 /* 2400 * It may be on either list in this state. 2401 * Remove from both for now. 2402 */ 2403 sigqueue_delete(&td->td_sigqueue, sig); 2404 return; 2405 } 2406 2407 /* 2408 * Don't awaken a sleeping thread for SIGSTOP if the 2409 * STOP signal is deferred. 2410 */ 2411 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2412 goto out; 2413 2414 /* 2415 * Give low priority threads a better chance to run. 2416 */ 2417 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2418 sched_prio(td, PUSER); 2419 2420 wakeup_swapper = sleepq_abort(td, intrval); 2421 } else { 2422 /* 2423 * Other states do nothing with the signal immediately, 2424 * other than kicking ourselves if we are running. 2425 * It will either never be noticed, or noticed very soon. 2426 */ 2427#ifdef SMP 2428 if (TD_IS_RUNNING(td) && td != curthread) 2429 forward_signal(td); 2430#endif 2431 } 2432out: 2433 PROC_SUNLOCK(p); 2434 thread_unlock(td); 2435 if (wakeup_swapper) 2436 kick_proc0(); 2437} 2438 2439static void 2440sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2441{ 2442 struct thread *td2; 2443 2444 PROC_LOCK_ASSERT(p, MA_OWNED); 2445 PROC_SLOCK_ASSERT(p, MA_OWNED); 2446 2447 FOREACH_THREAD_IN_PROC(p, td2) { 2448 thread_lock(td2); 2449 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2450 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2451 (td2->td_flags & TDF_SINTR)) { 2452 if (td2->td_flags & TDF_SBDRY) { 2453 /* 2454 * Once a thread is asleep with 2455 * TDF_SBDRY set, it should never 2456 * become suspended due to this check. 2457 */ 2458 KASSERT(!TD_IS_SUSPENDED(td2), 2459 ("thread with deferred stops suspended")); 2460 } else if (!TD_IS_SUSPENDED(td2)) { 2461 thread_suspend_one(td2); 2462 } 2463 } else if (!TD_IS_SUSPENDED(td2)) { 2464 if (sending || td != td2) 2465 td2->td_flags |= TDF_ASTPENDING; 2466#ifdef SMP 2467 if (TD_IS_RUNNING(td2) && td2 != td) 2468 forward_signal(td2); 2469#endif 2470 } 2471 thread_unlock(td2); 2472 } 2473} 2474 2475int 2476ptracestop(struct thread *td, int sig) 2477{ 2478 struct proc *p = td->td_proc; 2479 2480 PROC_LOCK_ASSERT(p, MA_OWNED); 2481 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2482 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2483 &p->p_mtx.lock_object, "Stopping for traced signal"); 2484 2485 td->td_dbgflags |= TDB_XSIG; 2486 td->td_xsig = sig; 2487 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2488 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2489 PROC_SLOCK(p); 2490 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2491 if (p->p_flag & P_SINGLE_EXIT && 2492 !(td->td_dbgflags & TDB_EXIT)) { 2493 /* 2494 * Ignore ptrace stops except for thread exit 2495 * events when the process exits. 2496 */ 2497 td->td_dbgflags &= ~TDB_XSIG; 2498 PROC_SUNLOCK(p); 2499 return (sig); 2500 } 2501 /* 2502 * Just make wait() to work, the last stopped thread 2503 * will win. 2504 */ 2505 p->p_xstat = sig; 2506 p->p_xthread = td; 2507 p->p_flag |= (P_STOPPED_SIG|P_STOPPED_TRACE); 2508 sig_suspend_threads(td, p, 0); 2509 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2510 td->td_dbgflags &= ~TDB_STOPATFORK; 2511 cv_broadcast(&p->p_dbgwait); 2512 } 2513stopme: 2514 thread_suspend_switch(td, p); 2515 if (p->p_xthread == td) 2516 p->p_xthread = NULL; 2517 if (!(p->p_flag & P_TRACED)) 2518 break; 2519 if (td->td_dbgflags & TDB_SUSPEND) { 2520 if (p->p_flag & P_SINGLE_EXIT) 2521 break; 2522 goto stopme; 2523 } 2524 } 2525 PROC_SUNLOCK(p); 2526 return (td->td_xsig); 2527} 2528 2529static void 2530reschedule_signals(struct proc *p, sigset_t block, int flags) 2531{ 2532 struct sigacts *ps; 2533 struct thread *td; 2534 int sig; 2535 2536 PROC_LOCK_ASSERT(p, MA_OWNED); 2537 ps = p->p_sigacts; 2538 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2539 MA_OWNED : MA_NOTOWNED); 2540 if (SIGISEMPTY(p->p_siglist)) 2541 return; 2542 SIGSETAND(block, p->p_siglist); 2543 while ((sig = sig_ffs(&block)) != 0) { 2544 SIGDELSET(block, sig); 2545 td = sigtd(p, sig, 0); 2546 signotify(td); 2547 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2548 mtx_lock(&ps->ps_mtx); 2549 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2550 tdsigwakeup(td, sig, SIG_CATCH, 2551 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2552 ERESTART)); 2553 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2554 mtx_unlock(&ps->ps_mtx); 2555 } 2556} 2557 2558void 2559tdsigcleanup(struct thread *td) 2560{ 2561 struct proc *p; 2562 sigset_t unblocked; 2563 2564 p = td->td_proc; 2565 PROC_LOCK_ASSERT(p, MA_OWNED); 2566 2567 sigqueue_flush(&td->td_sigqueue); 2568 if (p->p_numthreads == 1) 2569 return; 2570 2571 /* 2572 * Since we cannot handle signals, notify signal post code 2573 * about this by filling the sigmask. 2574 * 2575 * Also, if needed, wake up thread(s) that do not block the 2576 * same signals as the exiting thread, since the thread might 2577 * have been selected for delivery and woken up. 2578 */ 2579 SIGFILLSET(unblocked); 2580 SIGSETNAND(unblocked, td->td_sigmask); 2581 SIGFILLSET(td->td_sigmask); 2582 reschedule_signals(p, unblocked, 0); 2583 2584} 2585 2586/* 2587 * Defer the delivery of SIGSTOP for the current thread. Returns true 2588 * if stops were deferred and false if they were already deferred. 2589 */ 2590int 2591sigdeferstop(void) 2592{ 2593 struct thread *td; 2594 2595 td = curthread; 2596 if (td->td_flags & TDF_SBDRY) 2597 return (0); 2598 thread_lock(td); 2599 td->td_flags |= TDF_SBDRY; 2600 thread_unlock(td); 2601 return (1); 2602} 2603 2604/* 2605 * Permit the delivery of SIGSTOP for the current thread. This does 2606 * not immediately suspend if a stop was posted. Instead, the thread 2607 * will suspend either via ast() or a subsequent interruptible sleep. 2608 */ 2609int 2610sigallowstop(void) 2611{ 2612 struct thread *td; 2613 int prev; 2614 2615 td = curthread; 2616 thread_lock(td); 2617 prev = (td->td_flags & TDF_SBDRY) != 0; 2618 td->td_flags &= ~TDF_SBDRY; 2619 thread_unlock(td); 2620 return (prev); 2621} 2622 2623/* 2624 * If the current process has received a signal (should be caught or cause 2625 * termination, should interrupt current syscall), return the signal number. 2626 * Stop signals with default action are processed immediately, then cleared; 2627 * they aren't returned. This is checked after each entry to the system for 2628 * a syscall or trap (though this can usually be done without calling issignal 2629 * by checking the pending signal masks in cursig.) The normal call 2630 * sequence is 2631 * 2632 * while (sig = cursig(curthread)) 2633 * postsig(sig); 2634 */ 2635static int 2636issignal(struct thread *td) 2637{ 2638 struct proc *p; 2639 struct sigacts *ps; 2640 struct sigqueue *queue; 2641 sigset_t sigpending; 2642 int sig, prop, newsig; 2643 2644 p = td->td_proc; 2645 ps = p->p_sigacts; 2646 mtx_assert(&ps->ps_mtx, MA_OWNED); 2647 PROC_LOCK_ASSERT(p, MA_OWNED); 2648 for (;;) { 2649 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2650 2651 sigpending = td->td_sigqueue.sq_signals; 2652 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2653 SIGSETNAND(sigpending, td->td_sigmask); 2654 2655 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2656 SIG_STOPSIGMASK(sigpending); 2657 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2658 return (0); 2659 sig = sig_ffs(&sigpending); 2660 2661 if (p->p_stops & S_SIG) { 2662 mtx_unlock(&ps->ps_mtx); 2663 stopevent(p, S_SIG, sig); 2664 mtx_lock(&ps->ps_mtx); 2665 } 2666 2667 /* 2668 * We should see pending but ignored signals 2669 * only if P_TRACED was on when they were posted. 2670 */ 2671 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2672 sigqueue_delete(&td->td_sigqueue, sig); 2673 sigqueue_delete(&p->p_sigqueue, sig); 2674 continue; 2675 } 2676 if (p->p_flag & P_TRACED && (p->p_flag & P_PPTRACE) == 0) { 2677 /* 2678 * If traced, always stop. 2679 * Remove old signal from queue before the stop. 2680 * XXX shrug off debugger, it causes siginfo to 2681 * be thrown away. 2682 */ 2683 queue = &td->td_sigqueue; 2684 td->td_dbgksi.ksi_signo = 0; 2685 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2686 queue = &p->p_sigqueue; 2687 sigqueue_get(queue, sig, &td->td_dbgksi); 2688 } 2689 2690 mtx_unlock(&ps->ps_mtx); 2691 newsig = ptracestop(td, sig); 2692 mtx_lock(&ps->ps_mtx); 2693 2694 if (sig != newsig) { 2695 2696 /* 2697 * If parent wants us to take the signal, 2698 * then it will leave it in p->p_xstat; 2699 * otherwise we just look for signals again. 2700 */ 2701 if (newsig == 0) 2702 continue; 2703 sig = newsig; 2704 2705 /* 2706 * Put the new signal into td_sigqueue. If the 2707 * signal is being masked, look for other 2708 * signals. 2709 */ 2710 sigqueue_add(queue, sig, NULL); 2711 if (SIGISMEMBER(td->td_sigmask, sig)) 2712 continue; 2713 signotify(td); 2714 } else { 2715 if (td->td_dbgksi.ksi_signo != 0) { 2716 td->td_dbgksi.ksi_flags |= KSI_HEAD; 2717 if (sigqueue_add(&td->td_sigqueue, sig, 2718 &td->td_dbgksi) != 0) 2719 td->td_dbgksi.ksi_signo = 0; 2720 } 2721 if (td->td_dbgksi.ksi_signo == 0) 2722 sigqueue_add(&td->td_sigqueue, sig, 2723 NULL); 2724 } 2725 2726 /* 2727 * If the traced bit got turned off, go back up 2728 * to the top to rescan signals. This ensures 2729 * that p_sig* and p_sigact are consistent. 2730 */ 2731 if ((p->p_flag & P_TRACED) == 0) 2732 continue; 2733 } 2734 2735 prop = sigprop(sig); 2736 2737 /* 2738 * Decide whether the signal should be returned. 2739 * Return the signal's number, or fall through 2740 * to clear it from the pending mask. 2741 */ 2742 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2743 2744 case (intptr_t)SIG_DFL: 2745 /* 2746 * Don't take default actions on system processes. 2747 */ 2748 if (p->p_pid <= 1) { 2749#ifdef DIAGNOSTIC 2750 /* 2751 * Are you sure you want to ignore SIGSEGV 2752 * in init? XXX 2753 */ 2754 printf("Process (pid %lu) got signal %d\n", 2755 (u_long)p->p_pid, sig); 2756#endif 2757 break; /* == ignore */ 2758 } 2759 /* 2760 * If there is a pending stop signal to process 2761 * with default action, stop here, 2762 * then clear the signal. However, 2763 * if process is member of an orphaned 2764 * process group, ignore tty stop signals. 2765 */ 2766 if (prop & SA_STOP) { 2767 if (p->p_flag & (P_TRACED|P_WEXIT) || 2768 (p->p_pgrp->pg_jobc == 0 && 2769 prop & SA_TTYSTOP)) 2770 break; /* == ignore */ 2771 mtx_unlock(&ps->ps_mtx); 2772 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2773 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2774 p->p_flag |= P_STOPPED_SIG; 2775 p->p_xstat = sig; 2776 PROC_SLOCK(p); 2777 sig_suspend_threads(td, p, 0); 2778 thread_suspend_switch(td, p); 2779 PROC_SUNLOCK(p); 2780 mtx_lock(&ps->ps_mtx); 2781 break; 2782 } else if (prop & SA_IGNORE) { 2783 /* 2784 * Except for SIGCONT, shouldn't get here. 2785 * Default action is to ignore; drop it. 2786 */ 2787 break; /* == ignore */ 2788 } else 2789 return (sig); 2790 /*NOTREACHED*/ 2791 2792 case (intptr_t)SIG_IGN: 2793 /* 2794 * Masking above should prevent us ever trying 2795 * to take action on an ignored signal other 2796 * than SIGCONT, unless process is traced. 2797 */ 2798 if ((prop & SA_CONT) == 0 && 2799 (p->p_flag & P_TRACED) == 0) 2800 printf("issignal\n"); 2801 break; /* == ignore */ 2802 2803 default: 2804 /* 2805 * This signal has an action, let 2806 * postsig() process it. 2807 */ 2808 return (sig); 2809 } 2810 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2811 sigqueue_delete(&p->p_sigqueue, sig); 2812 } 2813 /* NOTREACHED */ 2814} 2815 2816void 2817thread_stopped(struct proc *p) 2818{ 2819 int n; 2820 2821 PROC_LOCK_ASSERT(p, MA_OWNED); 2822 PROC_SLOCK_ASSERT(p, MA_OWNED); 2823 n = p->p_suspcount; 2824 if (p == curproc) 2825 n++; 2826 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2827 PROC_SUNLOCK(p); 2828 p->p_flag &= ~P_WAITED; 2829 PROC_LOCK(p->p_pptr); 2830 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2831 CLD_TRAPPED : CLD_STOPPED); 2832 PROC_UNLOCK(p->p_pptr); 2833 PROC_SLOCK(p); 2834 } 2835} 2836 2837/* 2838 * Take the action for the specified signal 2839 * from the current set of pending signals. 2840 */ 2841int 2842postsig(sig) 2843 register int sig; 2844{ 2845 struct thread *td = curthread; 2846 register struct proc *p = td->td_proc; 2847 struct sigacts *ps; 2848 sig_t action; 2849 ksiginfo_t ksi; 2850 sigset_t returnmask; 2851 2852 KASSERT(sig != 0, ("postsig")); 2853 2854 PROC_LOCK_ASSERT(p, MA_OWNED); 2855 ps = p->p_sigacts; 2856 mtx_assert(&ps->ps_mtx, MA_OWNED); 2857 ksiginfo_init(&ksi); 2858 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2859 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2860 return (0); 2861 ksi.ksi_signo = sig; 2862 if (ksi.ksi_code == SI_TIMER) 2863 itimer_accept(p, ksi.ksi_timerid, &ksi); 2864 action = ps->ps_sigact[_SIG_IDX(sig)]; 2865#ifdef KTRACE 2866 if (KTRPOINT(td, KTR_PSIG)) 2867 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2868 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2869#endif 2870 if (p->p_stops & S_SIG) { 2871 mtx_unlock(&ps->ps_mtx); 2872 stopevent(p, S_SIG, sig); 2873 mtx_lock(&ps->ps_mtx); 2874 } 2875 2876 if (action == SIG_DFL) { 2877 /* 2878 * Default action, where the default is to kill 2879 * the process. (Other cases were ignored above.) 2880 */ 2881 mtx_unlock(&ps->ps_mtx); 2882 sigexit(td, sig); 2883 /* NOTREACHED */ 2884 } else { 2885 /* 2886 * If we get here, the signal must be caught. 2887 */ 2888 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2889 ("postsig action")); 2890 /* 2891 * Set the new mask value and also defer further 2892 * occurrences of this signal. 2893 * 2894 * Special case: user has done a sigsuspend. Here the 2895 * current mask is not of interest, but rather the 2896 * mask from before the sigsuspend is what we want 2897 * restored after the signal processing is completed. 2898 */ 2899 if (td->td_pflags & TDP_OLDMASK) { 2900 returnmask = td->td_oldsigmask; 2901 td->td_pflags &= ~TDP_OLDMASK; 2902 } else 2903 returnmask = td->td_sigmask; 2904 2905 if (p->p_sig == sig) { 2906 p->p_code = 0; 2907 p->p_sig = 0; 2908 } 2909 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2910 postsig_done(sig, td, ps); 2911 } 2912 return (1); 2913} 2914 2915/* 2916 * Kill the current process for stated reason. 2917 */ 2918void 2919killproc(p, why) 2920 struct proc *p; 2921 char *why; 2922{ 2923 2924 PROC_LOCK_ASSERT(p, MA_OWNED); 2925 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2926 p->p_comm); 2927 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2928 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2929 p->p_flag |= P_WKILLED; 2930 kern_psignal(p, SIGKILL); 2931} 2932 2933/* 2934 * Force the current process to exit with the specified signal, dumping core 2935 * if appropriate. We bypass the normal tests for masked and caught signals, 2936 * allowing unrecoverable failures to terminate the process without changing 2937 * signal state. Mark the accounting record with the signal termination. 2938 * If dumping core, save the signal number for the debugger. Calls exit and 2939 * does not return. 2940 */ 2941void 2942sigexit(td, sig) 2943 struct thread *td; 2944 int sig; 2945{ 2946 struct proc *p = td->td_proc; 2947 2948 PROC_LOCK_ASSERT(p, MA_OWNED); 2949 p->p_acflag |= AXSIG; 2950 /* 2951 * We must be single-threading to generate a core dump. This 2952 * ensures that the registers in the core file are up-to-date. 2953 * Also, the ELF dump handler assumes that the thread list doesn't 2954 * change out from under it. 2955 * 2956 * XXX If another thread attempts to single-thread before us 2957 * (e.g. via fork()), we won't get a dump at all. 2958 */ 2959 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 2960 p->p_sig = sig; 2961 /* 2962 * Log signals which would cause core dumps 2963 * (Log as LOG_INFO to appease those who don't want 2964 * these messages.) 2965 * XXX : Todo, as well as euid, write out ruid too 2966 * Note that coredump() drops proc lock. 2967 */ 2968 if (coredump(td) == 0) 2969 sig |= WCOREFLAG; 2970 if (kern_logsigexit) 2971 log(LOG_INFO, 2972 "pid %d (%s), uid %d: exited on signal %d%s\n", 2973 p->p_pid, p->p_comm, 2974 td->td_ucred ? td->td_ucred->cr_uid : -1, 2975 sig &~ WCOREFLAG, 2976 sig & WCOREFLAG ? " (core dumped)" : ""); 2977 } else 2978 PROC_UNLOCK(p); 2979 exit1(td, W_EXITCODE(0, sig)); 2980 /* NOTREACHED */ 2981} 2982 2983/* 2984 * Send queued SIGCHLD to parent when child process's state 2985 * is changed. 2986 */ 2987static void 2988sigparent(struct proc *p, int reason, int status) 2989{ 2990 PROC_LOCK_ASSERT(p, MA_OWNED); 2991 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 2992 2993 if (p->p_ksi != NULL) { 2994 p->p_ksi->ksi_signo = SIGCHLD; 2995 p->p_ksi->ksi_code = reason; 2996 p->p_ksi->ksi_status = status; 2997 p->p_ksi->ksi_pid = p->p_pid; 2998 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 2999 if (KSI_ONQ(p->p_ksi)) 3000 return; 3001 } 3002 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3003} 3004 3005static void 3006childproc_jobstate(struct proc *p, int reason, int sig) 3007{ 3008 struct sigacts *ps; 3009 3010 PROC_LOCK_ASSERT(p, MA_OWNED); 3011 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3012 3013 /* 3014 * Wake up parent sleeping in kern_wait(), also send 3015 * SIGCHLD to parent, but SIGCHLD does not guarantee 3016 * that parent will awake, because parent may masked 3017 * the signal. 3018 */ 3019 p->p_pptr->p_flag |= P_STATCHILD; 3020 wakeup(p->p_pptr); 3021 3022 ps = p->p_pptr->p_sigacts; 3023 mtx_lock(&ps->ps_mtx); 3024 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3025 mtx_unlock(&ps->ps_mtx); 3026 sigparent(p, reason, sig); 3027 } else 3028 mtx_unlock(&ps->ps_mtx); 3029} 3030 3031void 3032childproc_stopped(struct proc *p, int reason) 3033{ 3034 /* p_xstat is a plain signal number, not a full wait() status here. */ 3035 childproc_jobstate(p, reason, p->p_xstat); 3036} 3037 3038void 3039childproc_continued(struct proc *p) 3040{ 3041 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3042} 3043 3044void 3045childproc_exited(struct proc *p) 3046{ 3047 int reason; 3048 int xstat = p->p_xstat; /* convert to int */ 3049 int status; 3050 3051 if (WCOREDUMP(xstat)) 3052 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3053 else if (WIFSIGNALED(xstat)) 3054 reason = CLD_KILLED, status = WTERMSIG(xstat); 3055 else 3056 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3057 /* 3058 * XXX avoid calling wakeup(p->p_pptr), the work is 3059 * done in exit1(). 3060 */ 3061 sigparent(p, reason, status); 3062} 3063 3064/* 3065 * We only have 1 character for the core count in the format 3066 * string, so the range will be 0-9 3067 */ 3068#define MAX_NUM_CORES 10 3069static int num_cores = 5; 3070 3071static int 3072sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3073{ 3074 int error; 3075 int new_val; 3076 3077 new_val = num_cores; 3078 error = sysctl_handle_int(oidp, &new_val, 0, req); 3079 if (error != 0 || req->newptr == NULL) 3080 return (error); 3081 if (new_val > MAX_NUM_CORES) 3082 new_val = MAX_NUM_CORES; 3083 if (new_val < 0) 3084 new_val = 0; 3085 num_cores = new_val; 3086 return (0); 3087} 3088SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3089 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3090 3091#if defined(COMPRESS_USER_CORES) 3092int compress_user_cores = 1; 3093SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3094 &compress_user_cores, 0, "Compression of user corefiles"); 3095 3096int compress_user_cores_gzlevel = -1; /* default level */ 3097SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3098 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3099 3100#define GZ_SUFFIX ".gz" 3101#define GZ_SUFFIX_LEN 3 3102#endif 3103 3104static char corefilename[MAXPATHLEN] = {"%N.core"}; 3105TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3106SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3107 sizeof(corefilename), "Process corefile name format string"); 3108 3109/* 3110 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3111 * Expand the name described in corefilename, using name, uid, and pid 3112 * and open/create core file. 3113 * corefilename is a printf-like string, with three format specifiers: 3114 * %N name of process ("name") 3115 * %P process id (pid) 3116 * %U user id (uid) 3117 * For example, "%N.core" is the default; they can be disabled completely 3118 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3119 * This is controlled by the sysctl variable kern.corefile (see above). 3120 */ 3121static int 3122corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3123 int compress, struct vnode **vpp, char **namep) 3124{ 3125 struct nameidata nd; 3126 struct sbuf sb; 3127 const char *format; 3128 char *hostname, *name; 3129 int indexpos, i, error, cmode, flags, oflags; 3130 3131 hostname = NULL; 3132 format = corefilename; 3133 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3134 indexpos = -1; 3135 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3136 for (i = 0; format[i] != '\0'; i++) { 3137 switch (format[i]) { 3138 case '%': /* Format character */ 3139 i++; 3140 switch (format[i]) { 3141 case '%': 3142 sbuf_putc(&sb, '%'); 3143 break; 3144 case 'H': /* hostname */ 3145 if (hostname == NULL) { 3146 hostname = malloc(MAXHOSTNAMELEN, 3147 M_TEMP, M_WAITOK); 3148 } 3149 getcredhostname(td->td_ucred, hostname, 3150 MAXHOSTNAMELEN); 3151 sbuf_printf(&sb, "%s", hostname); 3152 break; 3153 case 'I': /* autoincrementing index */ 3154 sbuf_printf(&sb, "0"); 3155 indexpos = sbuf_len(&sb) - 1; 3156 break; 3157 case 'N': /* process name */ 3158 sbuf_printf(&sb, "%s", comm); 3159 break; 3160 case 'P': /* process id */ 3161 sbuf_printf(&sb, "%u", pid); 3162 break; 3163 case 'U': /* user id */ 3164 sbuf_printf(&sb, "%u", uid); 3165 break; 3166 default: 3167 log(LOG_ERR, 3168 "Unknown format character %c in " 3169 "corename `%s'\n", format[i], format); 3170 break; 3171 } 3172 break; 3173 default: 3174 sbuf_putc(&sb, format[i]); 3175 break; 3176 } 3177 } 3178 free(hostname, M_TEMP); 3179#ifdef COMPRESS_USER_CORES 3180 if (compress) 3181 sbuf_printf(&sb, GZ_SUFFIX); 3182#endif 3183 if (sbuf_error(&sb) != 0) { 3184 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3185 "long\n", (long)pid, comm, (u_long)uid); 3186 sbuf_delete(&sb); 3187 free(name, M_TEMP); 3188 return (ENOMEM); 3189 } 3190 sbuf_finish(&sb); 3191 sbuf_delete(&sb); 3192 3193 cmode = S_IRUSR | S_IWUSR; 3194 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3195 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3196 3197 /* 3198 * If the core format has a %I in it, then we need to check 3199 * for existing corefiles before returning a name. 3200 * To do this we iterate over 0..num_cores to find a 3201 * non-existing core file name to use. 3202 */ 3203 if (indexpos != -1) { 3204 for (i = 0; i < num_cores; i++) { 3205 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3206 name[indexpos] = '0' + i; 3207 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3208 error = vn_open_cred(&nd, &flags, cmode, oflags, 3209 td->td_ucred, NULL); 3210 if (error) { 3211 if (error == EEXIST) 3212 continue; 3213 log(LOG_ERR, 3214 "pid %d (%s), uid (%u): Path `%s' failed " 3215 "on initial open test, error = %d\n", 3216 pid, comm, uid, name, error); 3217 } 3218 goto out; 3219 } 3220 } 3221 3222 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3223 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3224 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3225out: 3226 if (error) { 3227#ifdef AUDIT 3228 audit_proc_coredump(td, name, error); 3229#endif 3230 free(name, M_TEMP); 3231 return (error); 3232 } 3233 NDFREE(&nd, NDF_ONLY_PNBUF); 3234 *vpp = nd.ni_vp; 3235 *namep = name; 3236 return (0); 3237} 3238 3239/* 3240 * Dump a process' core. The main routine does some 3241 * policy checking, and creates the name of the coredump; 3242 * then it passes on a vnode and a size limit to the process-specific 3243 * coredump routine if there is one; if there _is not_ one, it returns 3244 * ENOSYS; otherwise it returns the error from the process-specific routine. 3245 */ 3246 3247static int 3248coredump(struct thread *td) 3249{ 3250 struct proc *p = td->td_proc; 3251 struct ucred *cred = td->td_ucred; 3252 struct vnode *vp; 3253 struct flock lf; 3254 struct vattr vattr; 3255 int error, error1, locked; 3256 struct mount *mp; 3257 char *name; /* name of corefile */ 3258 off_t limit; 3259 int compress; 3260 3261#ifdef COMPRESS_USER_CORES 3262 compress = compress_user_cores; 3263#else 3264 compress = 0; 3265#endif 3266 PROC_LOCK_ASSERT(p, MA_OWNED); 3267 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3268 _STOPEVENT(p, S_CORE, 0); 3269 3270 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3271 (p->p_flag2 & P2_NOTRACE) != 0) { 3272 PROC_UNLOCK(p); 3273 return (EFAULT); 3274 } 3275 3276 /* 3277 * Note that the bulk of limit checking is done after 3278 * the corefile is created. The exception is if the limit 3279 * for corefiles is 0, in which case we don't bother 3280 * creating the corefile at all. This layout means that 3281 * a corefile is truncated instead of not being created, 3282 * if it is larger than the limit. 3283 */ 3284 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3285 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3286 PROC_UNLOCK(p); 3287 return (EFBIG); 3288 } 3289 PROC_UNLOCK(p); 3290 3291restart: 3292 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3293 &vp, &name); 3294 if (error != 0) 3295 return (error); 3296 3297 /* Don't dump to non-regular files or files with links. */ 3298 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3299 vattr.va_nlink != 1) { 3300 VOP_UNLOCK(vp, 0); 3301 error = EFAULT; 3302 goto close; 3303 } 3304 3305 VOP_UNLOCK(vp, 0); 3306 lf.l_whence = SEEK_SET; 3307 lf.l_start = 0; 3308 lf.l_len = 0; 3309 lf.l_type = F_WRLCK; 3310 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3311 3312 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3313 lf.l_type = F_UNLCK; 3314 if (locked) 3315 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3316 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3317 goto out; 3318 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3319 goto out; 3320 free(name, M_TEMP); 3321 goto restart; 3322 } 3323 3324 VATTR_NULL(&vattr); 3325 vattr.va_size = 0; 3326 if (set_core_nodump_flag) 3327 vattr.va_flags = UF_NODUMP; 3328 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3329 VOP_SETATTR(vp, &vattr, cred); 3330 VOP_UNLOCK(vp, 0); 3331 vn_finished_write(mp); 3332 PROC_LOCK(p); 3333 p->p_acflag |= ACORE; 3334 PROC_UNLOCK(p); 3335 3336 if (p->p_sysent->sv_coredump != NULL) { 3337 error = p->p_sysent->sv_coredump(td, vp, limit, 3338 compress ? IMGACT_CORE_COMPRESS : 0); 3339 } else { 3340 error = ENOSYS; 3341 } 3342 3343 if (locked) { 3344 lf.l_type = F_UNLCK; 3345 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3346 } 3347close: 3348 error1 = vn_close(vp, FWRITE, cred, td); 3349 if (error == 0) 3350 error = error1; 3351out: 3352#ifdef AUDIT 3353 audit_proc_coredump(td, name, error); 3354#endif 3355 free(name, M_TEMP); 3356 return (error); 3357} 3358 3359/* 3360 * Nonexistent system call-- signal process (may want to handle it). Flag 3361 * error in case process won't see signal immediately (blocked or ignored). 3362 */ 3363#ifndef _SYS_SYSPROTO_H_ 3364struct nosys_args { 3365 int dummy; 3366}; 3367#endif 3368/* ARGSUSED */ 3369int 3370nosys(td, args) 3371 struct thread *td; 3372 struct nosys_args *args; 3373{ 3374 struct proc *p = td->td_proc; 3375 3376 PROC_LOCK(p); 3377 tdsignal(td, SIGSYS); 3378 PROC_UNLOCK(p); 3379 return (ENOSYS); 3380} 3381 3382/* 3383 * Send a SIGIO or SIGURG signal to a process or process group using stored 3384 * credentials rather than those of the current process. 3385 */ 3386void 3387pgsigio(sigiop, sig, checkctty) 3388 struct sigio **sigiop; 3389 int sig, checkctty; 3390{ 3391 ksiginfo_t ksi; 3392 struct sigio *sigio; 3393 3394 ksiginfo_init(&ksi); 3395 ksi.ksi_signo = sig; 3396 ksi.ksi_code = SI_KERNEL; 3397 3398 SIGIO_LOCK(); 3399 sigio = *sigiop; 3400 if (sigio == NULL) { 3401 SIGIO_UNLOCK(); 3402 return; 3403 } 3404 if (sigio->sio_pgid > 0) { 3405 PROC_LOCK(sigio->sio_proc); 3406 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3407 kern_psignal(sigio->sio_proc, sig); 3408 PROC_UNLOCK(sigio->sio_proc); 3409 } else if (sigio->sio_pgid < 0) { 3410 struct proc *p; 3411 3412 PGRP_LOCK(sigio->sio_pgrp); 3413 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3414 PROC_LOCK(p); 3415 if (p->p_state == PRS_NORMAL && 3416 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3417 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3418 kern_psignal(p, sig); 3419 PROC_UNLOCK(p); 3420 } 3421 PGRP_UNLOCK(sigio->sio_pgrp); 3422 } 3423 SIGIO_UNLOCK(); 3424} 3425 3426static int 3427filt_sigattach(struct knote *kn) 3428{ 3429 struct proc *p = curproc; 3430 3431 kn->kn_ptr.p_proc = p; 3432 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3433 3434 knlist_add(&p->p_klist, kn, 0); 3435 3436 return (0); 3437} 3438 3439static void 3440filt_sigdetach(struct knote *kn) 3441{ 3442 struct proc *p = kn->kn_ptr.p_proc; 3443 3444 knlist_remove(&p->p_klist, kn, 0); 3445} 3446 3447/* 3448 * signal knotes are shared with proc knotes, so we apply a mask to 3449 * the hint in order to differentiate them from process hints. This 3450 * could be avoided by using a signal-specific knote list, but probably 3451 * isn't worth the trouble. 3452 */ 3453static int 3454filt_signal(struct knote *kn, long hint) 3455{ 3456 3457 if (hint & NOTE_SIGNAL) { 3458 hint &= ~NOTE_SIGNAL; 3459 3460 if (kn->kn_id == hint) 3461 kn->kn_data++; 3462 } 3463 return (kn->kn_data != 0); 3464} 3465 3466struct sigacts * 3467sigacts_alloc(void) 3468{ 3469 struct sigacts *ps; 3470 3471 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3472 ps->ps_refcnt = 1; 3473 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3474 return (ps); 3475} 3476 3477void 3478sigacts_free(struct sigacts *ps) 3479{ 3480 3481 if (refcount_release(&ps->ps_refcnt) == 0) 3482 return; 3483 mtx_destroy(&ps->ps_mtx); 3484 free(ps, M_SUBPROC); 3485} 3486 3487struct sigacts * 3488sigacts_hold(struct sigacts *ps) 3489{ 3490 3491 refcount_acquire(&ps->ps_refcnt); 3492 return (ps); 3493} 3494 3495void 3496sigacts_copy(struct sigacts *dest, struct sigacts *src) 3497{ 3498 3499 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3500 mtx_lock(&src->ps_mtx); 3501 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3502 mtx_unlock(&src->ps_mtx); 3503} 3504 3505int 3506sigacts_shared(struct sigacts *ps) 3507{ 3508 3509 return (ps->ps_refcnt > 1); 3510} 3511