kern_sig.c revision 315963
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 315963 2017-03-25 20:14:08Z badger $"); 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 SIGEMPTYSET(list->sq_ptrace); 281 TAILQ_INIT(&list->sq_list); 282 list->sq_proc = p; 283 list->sq_flags = SQ_INIT; 284} 285 286/* 287 * Get a signal's ksiginfo. 288 * Return: 289 * 0 - signal not found 290 * others - signal number 291 */ 292static int 293sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 294{ 295 struct proc *p = sq->sq_proc; 296 struct ksiginfo *ksi, *next; 297 int count = 0; 298 299 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 300 301 if (!SIGISMEMBER(sq->sq_signals, signo)) 302 return (0); 303 304 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 305 count++; 306 SIGDELSET(sq->sq_ptrace, signo); 307 si->ksi_flags |= KSI_PTRACE; 308 } 309 if (SIGISMEMBER(sq->sq_kill, signo)) { 310 count++; 311 if (count == 1) 312 SIGDELSET(sq->sq_kill, signo); 313 } 314 315 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 316 if (ksi->ksi_signo == signo) { 317 if (count == 0) { 318 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 319 ksi->ksi_sigq = NULL; 320 ksiginfo_copy(ksi, si); 321 if (ksiginfo_tryfree(ksi) && p != NULL) 322 p->p_pendingcnt--; 323 } 324 if (++count > 1) 325 break; 326 } 327 } 328 329 if (count <= 1) 330 SIGDELSET(sq->sq_signals, signo); 331 si->ksi_signo = signo; 332 return (signo); 333} 334 335void 336sigqueue_take(ksiginfo_t *ksi) 337{ 338 struct ksiginfo *kp; 339 struct proc *p; 340 sigqueue_t *sq; 341 342 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 343 return; 344 345 p = sq->sq_proc; 346 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 347 ksi->ksi_sigq = NULL; 348 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 349 p->p_pendingcnt--; 350 351 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 352 kp = TAILQ_NEXT(kp, ksi_link)) { 353 if (kp->ksi_signo == ksi->ksi_signo) 354 break; 355 } 356 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 357 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 358 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 359} 360 361static int 362sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 363{ 364 struct proc *p = sq->sq_proc; 365 struct ksiginfo *ksi; 366 int ret = 0; 367 368 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 369 370 /* 371 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 372 * for these signals. 373 */ 374 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 375 SIGADDSET(sq->sq_kill, signo); 376 goto out_set_bit; 377 } 378 379 /* directly insert the ksi, don't copy it */ 380 if (si->ksi_flags & KSI_INS) { 381 if (si->ksi_flags & KSI_HEAD) 382 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 383 else 384 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 385 si->ksi_sigq = sq; 386 goto out_set_bit; 387 } 388 389 if (__predict_false(ksiginfo_zone == NULL)) { 390 SIGADDSET(sq->sq_kill, signo); 391 goto out_set_bit; 392 } 393 394 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 395 signal_overflow++; 396 ret = EAGAIN; 397 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 398 signal_alloc_fail++; 399 ret = EAGAIN; 400 } else { 401 if (p != NULL) 402 p->p_pendingcnt++; 403 ksiginfo_copy(si, ksi); 404 ksi->ksi_signo = signo; 405 if (si->ksi_flags & KSI_HEAD) 406 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 407 else 408 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 409 ksi->ksi_sigq = sq; 410 } 411 412 if (ret != 0) { 413 if ((si->ksi_flags & KSI_PTRACE) != 0) { 414 SIGADDSET(sq->sq_ptrace, signo); 415 ret = 0; 416 goto out_set_bit; 417 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 418 (si->ksi_flags & KSI_SIGQ) == 0) { 419 SIGADDSET(sq->sq_kill, signo); 420 ret = 0; 421 goto out_set_bit; 422 } 423 return (ret); 424 } 425 426out_set_bit: 427 SIGADDSET(sq->sq_signals, signo); 428 return (ret); 429} 430 431void 432sigqueue_flush(sigqueue_t *sq) 433{ 434 struct proc *p = sq->sq_proc; 435 ksiginfo_t *ksi; 436 437 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 438 439 if (p != NULL) 440 PROC_LOCK_ASSERT(p, MA_OWNED); 441 442 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 443 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 444 ksi->ksi_sigq = NULL; 445 if (ksiginfo_tryfree(ksi) && p != NULL) 446 p->p_pendingcnt--; 447 } 448 449 SIGEMPTYSET(sq->sq_signals); 450 SIGEMPTYSET(sq->sq_kill); 451 SIGEMPTYSET(sq->sq_ptrace); 452} 453 454static void 455sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 456{ 457 sigset_t tmp; 458 struct proc *p1, *p2; 459 ksiginfo_t *ksi, *next; 460 461 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 462 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 463 p1 = src->sq_proc; 464 p2 = dst->sq_proc; 465 /* Move siginfo to target list */ 466 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 467 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 468 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 469 if (p1 != NULL) 470 p1->p_pendingcnt--; 471 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 472 ksi->ksi_sigq = dst; 473 if (p2 != NULL) 474 p2->p_pendingcnt++; 475 } 476 } 477 478 /* Move pending bits to target list */ 479 tmp = src->sq_kill; 480 SIGSETAND(tmp, *set); 481 SIGSETOR(dst->sq_kill, tmp); 482 SIGSETNAND(src->sq_kill, tmp); 483 484 tmp = src->sq_ptrace; 485 SIGSETAND(tmp, *set); 486 SIGSETOR(dst->sq_ptrace, tmp); 487 SIGSETNAND(src->sq_ptrace, tmp); 488 489 tmp = src->sq_signals; 490 SIGSETAND(tmp, *set); 491 SIGSETOR(dst->sq_signals, tmp); 492 SIGSETNAND(src->sq_signals, tmp); 493} 494 495#if 0 496static void 497sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 498{ 499 sigset_t set; 500 501 SIGEMPTYSET(set); 502 SIGADDSET(set, signo); 503 sigqueue_move_set(src, dst, &set); 504} 505#endif 506 507static void 508sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 509{ 510 struct proc *p = sq->sq_proc; 511 ksiginfo_t *ksi, *next; 512 513 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 514 515 /* Remove siginfo queue */ 516 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 517 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 518 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 519 ksi->ksi_sigq = NULL; 520 if (ksiginfo_tryfree(ksi) && p != NULL) 521 p->p_pendingcnt--; 522 } 523 } 524 SIGSETNAND(sq->sq_kill, *set); 525 SIGSETNAND(sq->sq_ptrace, *set); 526 SIGSETNAND(sq->sq_signals, *set); 527} 528 529void 530sigqueue_delete(sigqueue_t *sq, int signo) 531{ 532 sigset_t set; 533 534 SIGEMPTYSET(set); 535 SIGADDSET(set, signo); 536 sigqueue_delete_set(sq, &set); 537} 538 539/* Remove a set of signals for a process */ 540static void 541sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 542{ 543 sigqueue_t worklist; 544 struct thread *td0; 545 546 PROC_LOCK_ASSERT(p, MA_OWNED); 547 548 sigqueue_init(&worklist, NULL); 549 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 550 551 FOREACH_THREAD_IN_PROC(p, td0) 552 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 553 554 sigqueue_flush(&worklist); 555} 556 557void 558sigqueue_delete_proc(struct proc *p, int signo) 559{ 560 sigset_t set; 561 562 SIGEMPTYSET(set); 563 SIGADDSET(set, signo); 564 sigqueue_delete_set_proc(p, &set); 565} 566 567static void 568sigqueue_delete_stopmask_proc(struct proc *p) 569{ 570 sigset_t set; 571 572 SIGEMPTYSET(set); 573 SIGADDSET(set, SIGSTOP); 574 SIGADDSET(set, SIGTSTP); 575 SIGADDSET(set, SIGTTIN); 576 SIGADDSET(set, SIGTTOU); 577 sigqueue_delete_set_proc(p, &set); 578} 579 580/* 581 * Determine signal that should be delivered to thread td, the current 582 * thread, 0 if none. If there is a pending stop signal with default 583 * action, the process stops in issignal(). 584 */ 585int 586cursig(struct thread *td) 587{ 588 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 589 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 590 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 591 return (SIGPENDING(td) ? issignal(td) : 0); 592} 593 594/* 595 * Arrange for ast() to handle unmasked pending signals on return to user 596 * mode. This must be called whenever a signal is added to td_sigqueue or 597 * unmasked in td_sigmask. 598 */ 599void 600signotify(struct thread *td) 601{ 602 struct proc *p; 603 604 p = td->td_proc; 605 606 PROC_LOCK_ASSERT(p, MA_OWNED); 607 608 if (SIGPENDING(td)) { 609 thread_lock(td); 610 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 611 thread_unlock(td); 612 } 613} 614 615int 616sigonstack(size_t sp) 617{ 618 struct thread *td = curthread; 619 620 return ((td->td_pflags & TDP_ALTSTACK) ? 621#if defined(COMPAT_43) 622 ((td->td_sigstk.ss_size == 0) ? 623 (td->td_sigstk.ss_flags & SS_ONSTACK) : 624 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 625#else 626 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 627#endif 628 : 0); 629} 630 631static __inline int 632sigprop(int sig) 633{ 634 635 if (sig > 0 && sig < NSIG) 636 return (sigproptbl[_SIG_IDX(sig)]); 637 return (0); 638} 639 640int 641sig_ffs(sigset_t *set) 642{ 643 int i; 644 645 for (i = 0; i < _SIG_WORDS; i++) 646 if (set->__bits[i]) 647 return (ffs(set->__bits[i]) + (i * 32)); 648 return (0); 649} 650 651static bool 652sigact_flag_test(struct sigaction *act, int flag) 653{ 654 655 /* 656 * SA_SIGINFO is reset when signal disposition is set to 657 * ignore or default. Other flags are kept according to user 658 * settings. 659 */ 660 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 661 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 662 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 663} 664 665/* 666 * kern_sigaction 667 * sigaction 668 * freebsd4_sigaction 669 * osigaction 670 */ 671int 672kern_sigaction(td, sig, act, oact, flags) 673 struct thread *td; 674 register int sig; 675 struct sigaction *act, *oact; 676 int flags; 677{ 678 struct sigacts *ps; 679 struct proc *p = td->td_proc; 680 681 if (!_SIG_VALID(sig)) 682 return (EINVAL); 683 if (act != NULL && act->sa_handler != SIG_DFL && 684 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 685 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 686 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 687 return (EINVAL); 688 689 PROC_LOCK(p); 690 ps = p->p_sigacts; 691 mtx_lock(&ps->ps_mtx); 692 if (oact) { 693 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 694 oact->sa_flags = 0; 695 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 696 oact->sa_flags |= SA_ONSTACK; 697 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 698 oact->sa_flags |= SA_RESTART; 699 if (SIGISMEMBER(ps->ps_sigreset, sig)) 700 oact->sa_flags |= SA_RESETHAND; 701 if (SIGISMEMBER(ps->ps_signodefer, sig)) 702 oact->sa_flags |= SA_NODEFER; 703 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 704 oact->sa_flags |= SA_SIGINFO; 705 oact->sa_sigaction = 706 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 707 } else 708 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 709 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 710 oact->sa_flags |= SA_NOCLDSTOP; 711 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 712 oact->sa_flags |= SA_NOCLDWAIT; 713 } 714 if (act) { 715 if ((sig == SIGKILL || sig == SIGSTOP) && 716 act->sa_handler != SIG_DFL) { 717 mtx_unlock(&ps->ps_mtx); 718 PROC_UNLOCK(p); 719 return (EINVAL); 720 } 721 722 /* 723 * Change setting atomically. 724 */ 725 726 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 727 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 728 if (sigact_flag_test(act, SA_SIGINFO)) { 729 ps->ps_sigact[_SIG_IDX(sig)] = 730 (__sighandler_t *)act->sa_sigaction; 731 SIGADDSET(ps->ps_siginfo, sig); 732 } else { 733 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 734 SIGDELSET(ps->ps_siginfo, sig); 735 } 736 if (!sigact_flag_test(act, SA_RESTART)) 737 SIGADDSET(ps->ps_sigintr, sig); 738 else 739 SIGDELSET(ps->ps_sigintr, sig); 740 if (sigact_flag_test(act, SA_ONSTACK)) 741 SIGADDSET(ps->ps_sigonstack, sig); 742 else 743 SIGDELSET(ps->ps_sigonstack, sig); 744 if (sigact_flag_test(act, SA_RESETHAND)) 745 SIGADDSET(ps->ps_sigreset, sig); 746 else 747 SIGDELSET(ps->ps_sigreset, sig); 748 if (sigact_flag_test(act, SA_NODEFER)) 749 SIGADDSET(ps->ps_signodefer, sig); 750 else 751 SIGDELSET(ps->ps_signodefer, sig); 752 if (sig == SIGCHLD) { 753 if (act->sa_flags & SA_NOCLDSTOP) 754 ps->ps_flag |= PS_NOCLDSTOP; 755 else 756 ps->ps_flag &= ~PS_NOCLDSTOP; 757 if (act->sa_flags & SA_NOCLDWAIT) { 758 /* 759 * Paranoia: since SA_NOCLDWAIT is implemented 760 * by reparenting the dying child to PID 1 (and 761 * trust it to reap the zombie), PID 1 itself 762 * is forbidden to set SA_NOCLDWAIT. 763 */ 764 if (p->p_pid == 1) 765 ps->ps_flag &= ~PS_NOCLDWAIT; 766 else 767 ps->ps_flag |= PS_NOCLDWAIT; 768 } else 769 ps->ps_flag &= ~PS_NOCLDWAIT; 770 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 771 ps->ps_flag |= PS_CLDSIGIGN; 772 else 773 ps->ps_flag &= ~PS_CLDSIGIGN; 774 } 775 /* 776 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 777 * and for signals set to SIG_DFL where the default is to 778 * ignore. However, don't put SIGCONT in ps_sigignore, as we 779 * have to restart the process. 780 */ 781 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 782 (sigprop(sig) & SA_IGNORE && 783 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 784 /* never to be seen again */ 785 sigqueue_delete_proc(p, sig); 786 if (sig != SIGCONT) 787 /* easier in psignal */ 788 SIGADDSET(ps->ps_sigignore, sig); 789 SIGDELSET(ps->ps_sigcatch, sig); 790 } else { 791 SIGDELSET(ps->ps_sigignore, sig); 792 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 793 SIGDELSET(ps->ps_sigcatch, sig); 794 else 795 SIGADDSET(ps->ps_sigcatch, sig); 796 } 797#ifdef COMPAT_FREEBSD4 798 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 799 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 800 (flags & KSA_FREEBSD4) == 0) 801 SIGDELSET(ps->ps_freebsd4, sig); 802 else 803 SIGADDSET(ps->ps_freebsd4, sig); 804#endif 805#ifdef COMPAT_43 806 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 807 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 808 (flags & KSA_OSIGSET) == 0) 809 SIGDELSET(ps->ps_osigset, sig); 810 else 811 SIGADDSET(ps->ps_osigset, sig); 812#endif 813 } 814 mtx_unlock(&ps->ps_mtx); 815 PROC_UNLOCK(p); 816 return (0); 817} 818 819#ifndef _SYS_SYSPROTO_H_ 820struct sigaction_args { 821 int sig; 822 struct sigaction *act; 823 struct sigaction *oact; 824}; 825#endif 826int 827sys_sigaction(td, uap) 828 struct thread *td; 829 register struct sigaction_args *uap; 830{ 831 struct sigaction act, oact; 832 register struct sigaction *actp, *oactp; 833 int error; 834 835 actp = (uap->act != NULL) ? &act : NULL; 836 oactp = (uap->oact != NULL) ? &oact : NULL; 837 if (actp) { 838 error = copyin(uap->act, actp, sizeof(act)); 839 if (error) 840 return (error); 841 } 842 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 843 if (oactp && !error) 844 error = copyout(oactp, uap->oact, sizeof(oact)); 845 return (error); 846} 847 848#ifdef COMPAT_FREEBSD4 849#ifndef _SYS_SYSPROTO_H_ 850struct freebsd4_sigaction_args { 851 int sig; 852 struct sigaction *act; 853 struct sigaction *oact; 854}; 855#endif 856int 857freebsd4_sigaction(td, uap) 858 struct thread *td; 859 register struct freebsd4_sigaction_args *uap; 860{ 861 struct sigaction act, oact; 862 register struct sigaction *actp, *oactp; 863 int error; 864 865 866 actp = (uap->act != NULL) ? &act : NULL; 867 oactp = (uap->oact != NULL) ? &oact : NULL; 868 if (actp) { 869 error = copyin(uap->act, actp, sizeof(act)); 870 if (error) 871 return (error); 872 } 873 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 874 if (oactp && !error) 875 error = copyout(oactp, uap->oact, sizeof(oact)); 876 return (error); 877} 878#endif /* COMAPT_FREEBSD4 */ 879 880#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 881#ifndef _SYS_SYSPROTO_H_ 882struct osigaction_args { 883 int signum; 884 struct osigaction *nsa; 885 struct osigaction *osa; 886}; 887#endif 888int 889osigaction(td, uap) 890 struct thread *td; 891 register struct osigaction_args *uap; 892{ 893 struct osigaction sa; 894 struct sigaction nsa, osa; 895 register struct sigaction *nsap, *osap; 896 int error; 897 898 if (uap->signum <= 0 || uap->signum >= ONSIG) 899 return (EINVAL); 900 901 nsap = (uap->nsa != NULL) ? &nsa : NULL; 902 osap = (uap->osa != NULL) ? &osa : NULL; 903 904 if (nsap) { 905 error = copyin(uap->nsa, &sa, sizeof(sa)); 906 if (error) 907 return (error); 908 nsap->sa_handler = sa.sa_handler; 909 nsap->sa_flags = sa.sa_flags; 910 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 911 } 912 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 913 if (osap && !error) { 914 sa.sa_handler = osap->sa_handler; 915 sa.sa_flags = osap->sa_flags; 916 SIG2OSIG(osap->sa_mask, sa.sa_mask); 917 error = copyout(&sa, uap->osa, sizeof(sa)); 918 } 919 return (error); 920} 921 922#if !defined(__i386__) 923/* Avoid replicating the same stub everywhere */ 924int 925osigreturn(td, uap) 926 struct thread *td; 927 struct osigreturn_args *uap; 928{ 929 930 return (nosys(td, (struct nosys_args *)uap)); 931} 932#endif 933#endif /* COMPAT_43 */ 934 935/* 936 * Initialize signal state for process 0; 937 * set to ignore signals that are ignored by default. 938 */ 939void 940siginit(p) 941 struct proc *p; 942{ 943 register int i; 944 struct sigacts *ps; 945 946 PROC_LOCK(p); 947 ps = p->p_sigacts; 948 mtx_lock(&ps->ps_mtx); 949 for (i = 1; i <= NSIG; i++) { 950 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 951 SIGADDSET(ps->ps_sigignore, i); 952 } 953 } 954 mtx_unlock(&ps->ps_mtx); 955 PROC_UNLOCK(p); 956} 957 958/* 959 * Reset specified signal to the default disposition. 960 */ 961static void 962sigdflt(struct sigacts *ps, int sig) 963{ 964 965 mtx_assert(&ps->ps_mtx, MA_OWNED); 966 SIGDELSET(ps->ps_sigcatch, sig); 967 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 968 SIGADDSET(ps->ps_sigignore, sig); 969 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 970 SIGDELSET(ps->ps_siginfo, sig); 971} 972 973/* 974 * Reset signals for an exec of the specified process. 975 */ 976void 977execsigs(struct proc *p) 978{ 979 struct sigacts *ps; 980 int sig; 981 struct thread *td; 982 983 /* 984 * Reset caught signals. Held signals remain held 985 * through td_sigmask (unless they were caught, 986 * and are now ignored by default). 987 */ 988 PROC_LOCK_ASSERT(p, MA_OWNED); 989 ps = p->p_sigacts; 990 mtx_lock(&ps->ps_mtx); 991 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 992 sig = sig_ffs(&ps->ps_sigcatch); 993 sigdflt(ps, sig); 994 if ((sigprop(sig) & SA_IGNORE) != 0) 995 sigqueue_delete_proc(p, sig); 996 } 997 /* 998 * Reset stack state to the user stack. 999 * Clear set of signals caught on the signal stack. 1000 */ 1001 td = curthread; 1002 MPASS(td->td_proc == p); 1003 td->td_sigstk.ss_flags = SS_DISABLE; 1004 td->td_sigstk.ss_size = 0; 1005 td->td_sigstk.ss_sp = 0; 1006 td->td_pflags &= ~TDP_ALTSTACK; 1007 /* 1008 * Reset no zombies if child dies flag as Solaris does. 1009 */ 1010 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1011 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1012 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1013 mtx_unlock(&ps->ps_mtx); 1014} 1015 1016/* 1017 * kern_sigprocmask() 1018 * 1019 * Manipulate signal mask. 1020 */ 1021int 1022kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1023 int flags) 1024{ 1025 sigset_t new_block, oset1; 1026 struct proc *p; 1027 int error; 1028 1029 p = td->td_proc; 1030 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1031 PROC_LOCK_ASSERT(p, MA_OWNED); 1032 else 1033 PROC_LOCK(p); 1034 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1035 ? MA_OWNED : MA_NOTOWNED); 1036 if (oset != NULL) 1037 *oset = td->td_sigmask; 1038 1039 error = 0; 1040 if (set != NULL) { 1041 switch (how) { 1042 case SIG_BLOCK: 1043 SIG_CANTMASK(*set); 1044 oset1 = td->td_sigmask; 1045 SIGSETOR(td->td_sigmask, *set); 1046 new_block = td->td_sigmask; 1047 SIGSETNAND(new_block, oset1); 1048 break; 1049 case SIG_UNBLOCK: 1050 SIGSETNAND(td->td_sigmask, *set); 1051 signotify(td); 1052 goto out; 1053 case SIG_SETMASK: 1054 SIG_CANTMASK(*set); 1055 oset1 = td->td_sigmask; 1056 if (flags & SIGPROCMASK_OLD) 1057 SIGSETLO(td->td_sigmask, *set); 1058 else 1059 td->td_sigmask = *set; 1060 new_block = td->td_sigmask; 1061 SIGSETNAND(new_block, oset1); 1062 signotify(td); 1063 break; 1064 default: 1065 error = EINVAL; 1066 goto out; 1067 } 1068 1069 /* 1070 * The new_block set contains signals that were not previously 1071 * blocked, but are blocked now. 1072 * 1073 * In case we block any signal that was not previously blocked 1074 * for td, and process has the signal pending, try to schedule 1075 * signal delivery to some thread that does not block the 1076 * signal, possibly waking it up. 1077 */ 1078 if (p->p_numthreads != 1) 1079 reschedule_signals(p, new_block, flags); 1080 } 1081 1082out: 1083 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1084 PROC_UNLOCK(p); 1085 return (error); 1086} 1087 1088#ifndef _SYS_SYSPROTO_H_ 1089struct sigprocmask_args { 1090 int how; 1091 const sigset_t *set; 1092 sigset_t *oset; 1093}; 1094#endif 1095int 1096sys_sigprocmask(td, uap) 1097 register struct thread *td; 1098 struct sigprocmask_args *uap; 1099{ 1100 sigset_t set, oset; 1101 sigset_t *setp, *osetp; 1102 int error; 1103 1104 setp = (uap->set != NULL) ? &set : NULL; 1105 osetp = (uap->oset != NULL) ? &oset : NULL; 1106 if (setp) { 1107 error = copyin(uap->set, setp, sizeof(set)); 1108 if (error) 1109 return (error); 1110 } 1111 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1112 if (osetp && !error) { 1113 error = copyout(osetp, uap->oset, sizeof(oset)); 1114 } 1115 return (error); 1116} 1117 1118#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1119#ifndef _SYS_SYSPROTO_H_ 1120struct osigprocmask_args { 1121 int how; 1122 osigset_t mask; 1123}; 1124#endif 1125int 1126osigprocmask(td, uap) 1127 register struct thread *td; 1128 struct osigprocmask_args *uap; 1129{ 1130 sigset_t set, oset; 1131 int error; 1132 1133 OSIG2SIG(uap->mask, set); 1134 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1135 SIG2OSIG(oset, td->td_retval[0]); 1136 return (error); 1137} 1138#endif /* COMPAT_43 */ 1139 1140int 1141sys_sigwait(struct thread *td, struct sigwait_args *uap) 1142{ 1143 ksiginfo_t ksi; 1144 sigset_t set; 1145 int error; 1146 1147 error = copyin(uap->set, &set, sizeof(set)); 1148 if (error) { 1149 td->td_retval[0] = error; 1150 return (0); 1151 } 1152 1153 error = kern_sigtimedwait(td, set, &ksi, NULL); 1154 if (error) { 1155 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1156 error = ERESTART; 1157 if (error == ERESTART) 1158 return (error); 1159 td->td_retval[0] = error; 1160 return (0); 1161 } 1162 1163 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1164 td->td_retval[0] = error; 1165 return (0); 1166} 1167 1168int 1169sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1170{ 1171 struct timespec ts; 1172 struct timespec *timeout; 1173 sigset_t set; 1174 ksiginfo_t ksi; 1175 int error; 1176 1177 if (uap->timeout) { 1178 error = copyin(uap->timeout, &ts, sizeof(ts)); 1179 if (error) 1180 return (error); 1181 1182 timeout = &ts; 1183 } else 1184 timeout = NULL; 1185 1186 error = copyin(uap->set, &set, sizeof(set)); 1187 if (error) 1188 return (error); 1189 1190 error = kern_sigtimedwait(td, set, &ksi, timeout); 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 1203sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1204{ 1205 ksiginfo_t ksi; 1206 sigset_t set; 1207 int error; 1208 1209 error = copyin(uap->set, &set, sizeof(set)); 1210 if (error) 1211 return (error); 1212 1213 error = kern_sigtimedwait(td, set, &ksi, NULL); 1214 if (error) 1215 return (error); 1216 1217 if (uap->info) 1218 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1219 1220 if (error == 0) 1221 td->td_retval[0] = ksi.ksi_signo; 1222 return (error); 1223} 1224 1225int 1226kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1227 struct timespec *timeout) 1228{ 1229 struct sigacts *ps; 1230 sigset_t saved_mask, new_block; 1231 struct proc *p; 1232 int error, sig, timo, timevalid = 0; 1233 struct timespec rts, ets, ts; 1234 struct timeval tv; 1235 1236 p = td->td_proc; 1237 error = 0; 1238 ets.tv_sec = 0; 1239 ets.tv_nsec = 0; 1240 1241 if (timeout != NULL) { 1242 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1243 timevalid = 1; 1244 getnanouptime(&rts); 1245 ets = rts; 1246 timespecadd(&ets, timeout); 1247 } 1248 } 1249 ksiginfo_init(ksi); 1250 /* Some signals can not be waited for. */ 1251 SIG_CANTMASK(waitset); 1252 ps = p->p_sigacts; 1253 PROC_LOCK(p); 1254 saved_mask = td->td_sigmask; 1255 SIGSETNAND(td->td_sigmask, waitset); 1256 for (;;) { 1257 mtx_lock(&ps->ps_mtx); 1258 sig = cursig(td); 1259 mtx_unlock(&ps->ps_mtx); 1260 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1261 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1262 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1263 error = 0; 1264 break; 1265 } 1266 } 1267 1268 if (error != 0) 1269 break; 1270 1271 /* 1272 * POSIX says this must be checked after looking for pending 1273 * signals. 1274 */ 1275 if (timeout != NULL) { 1276 if (!timevalid) { 1277 error = EINVAL; 1278 break; 1279 } 1280 getnanouptime(&rts); 1281 if (timespeccmp(&rts, &ets, >=)) { 1282 error = EAGAIN; 1283 break; 1284 } 1285 ts = ets; 1286 timespecsub(&ts, &rts); 1287 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1288 timo = tvtohz(&tv); 1289 } else { 1290 timo = 0; 1291 } 1292 1293 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1294 1295 if (timeout != NULL) { 1296 if (error == ERESTART) { 1297 /* Timeout can not be restarted. */ 1298 error = EINTR; 1299 } else if (error == EAGAIN) { 1300 /* We will calculate timeout by ourself. */ 1301 error = 0; 1302 } 1303 } 1304 } 1305 1306 new_block = saved_mask; 1307 SIGSETNAND(new_block, td->td_sigmask); 1308 td->td_sigmask = saved_mask; 1309 /* 1310 * Fewer signals can be delivered to us, reschedule signal 1311 * notification. 1312 */ 1313 if (p->p_numthreads != 1) 1314 reschedule_signals(p, new_block, 0); 1315 1316 if (error == 0) { 1317 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1318 1319 if (ksi->ksi_code == SI_TIMER) 1320 itimer_accept(p, ksi->ksi_timerid, ksi); 1321 1322#ifdef KTRACE 1323 if (KTRPOINT(td, KTR_PSIG)) { 1324 sig_t action; 1325 1326 mtx_lock(&ps->ps_mtx); 1327 action = ps->ps_sigact[_SIG_IDX(sig)]; 1328 mtx_unlock(&ps->ps_mtx); 1329 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1330 } 1331#endif 1332 if (sig == SIGKILL) 1333 sigexit(td, sig); 1334 } 1335 PROC_UNLOCK(p); 1336 return (error); 1337} 1338 1339#ifndef _SYS_SYSPROTO_H_ 1340struct sigpending_args { 1341 sigset_t *set; 1342}; 1343#endif 1344int 1345sys_sigpending(td, uap) 1346 struct thread *td; 1347 struct sigpending_args *uap; 1348{ 1349 struct proc *p = td->td_proc; 1350 sigset_t pending; 1351 1352 PROC_LOCK(p); 1353 pending = p->p_sigqueue.sq_signals; 1354 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1355 PROC_UNLOCK(p); 1356 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1357} 1358 1359#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1360#ifndef _SYS_SYSPROTO_H_ 1361struct osigpending_args { 1362 int dummy; 1363}; 1364#endif 1365int 1366osigpending(td, uap) 1367 struct thread *td; 1368 struct osigpending_args *uap; 1369{ 1370 struct proc *p = td->td_proc; 1371 sigset_t pending; 1372 1373 PROC_LOCK(p); 1374 pending = p->p_sigqueue.sq_signals; 1375 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1376 PROC_UNLOCK(p); 1377 SIG2OSIG(pending, td->td_retval[0]); 1378 return (0); 1379} 1380#endif /* COMPAT_43 */ 1381 1382#if defined(COMPAT_43) 1383/* 1384 * Generalized interface signal handler, 4.3-compatible. 1385 */ 1386#ifndef _SYS_SYSPROTO_H_ 1387struct osigvec_args { 1388 int signum; 1389 struct sigvec *nsv; 1390 struct sigvec *osv; 1391}; 1392#endif 1393/* ARGSUSED */ 1394int 1395osigvec(td, uap) 1396 struct thread *td; 1397 register struct osigvec_args *uap; 1398{ 1399 struct sigvec vec; 1400 struct sigaction nsa, osa; 1401 register struct sigaction *nsap, *osap; 1402 int error; 1403 1404 if (uap->signum <= 0 || uap->signum >= ONSIG) 1405 return (EINVAL); 1406 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1407 osap = (uap->osv != NULL) ? &osa : NULL; 1408 if (nsap) { 1409 error = copyin(uap->nsv, &vec, sizeof(vec)); 1410 if (error) 1411 return (error); 1412 nsap->sa_handler = vec.sv_handler; 1413 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1414 nsap->sa_flags = vec.sv_flags; 1415 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1416 } 1417 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1418 if (osap && !error) { 1419 vec.sv_handler = osap->sa_handler; 1420 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1421 vec.sv_flags = osap->sa_flags; 1422 vec.sv_flags &= ~SA_NOCLDWAIT; 1423 vec.sv_flags ^= SA_RESTART; 1424 error = copyout(&vec, uap->osv, sizeof(vec)); 1425 } 1426 return (error); 1427} 1428 1429#ifndef _SYS_SYSPROTO_H_ 1430struct osigblock_args { 1431 int mask; 1432}; 1433#endif 1434int 1435osigblock(td, uap) 1436 register struct thread *td; 1437 struct osigblock_args *uap; 1438{ 1439 sigset_t set, oset; 1440 1441 OSIG2SIG(uap->mask, set); 1442 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1443 SIG2OSIG(oset, td->td_retval[0]); 1444 return (0); 1445} 1446 1447#ifndef _SYS_SYSPROTO_H_ 1448struct osigsetmask_args { 1449 int mask; 1450}; 1451#endif 1452int 1453osigsetmask(td, uap) 1454 struct thread *td; 1455 struct osigsetmask_args *uap; 1456{ 1457 sigset_t set, oset; 1458 1459 OSIG2SIG(uap->mask, set); 1460 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1461 SIG2OSIG(oset, td->td_retval[0]); 1462 return (0); 1463} 1464#endif /* COMPAT_43 */ 1465 1466/* 1467 * Suspend calling thread until signal, providing mask to be set in the 1468 * meantime. 1469 */ 1470#ifndef _SYS_SYSPROTO_H_ 1471struct sigsuspend_args { 1472 const sigset_t *sigmask; 1473}; 1474#endif 1475/* ARGSUSED */ 1476int 1477sys_sigsuspend(td, uap) 1478 struct thread *td; 1479 struct sigsuspend_args *uap; 1480{ 1481 sigset_t mask; 1482 int error; 1483 1484 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1485 if (error) 1486 return (error); 1487 return (kern_sigsuspend(td, mask)); 1488} 1489 1490int 1491kern_sigsuspend(struct thread *td, sigset_t mask) 1492{ 1493 struct proc *p = td->td_proc; 1494 int has_sig, sig; 1495 1496 /* 1497 * When returning from sigsuspend, we want 1498 * the old mask to be restored after the 1499 * signal handler has finished. Thus, we 1500 * save it here and mark the sigacts structure 1501 * to indicate this. 1502 */ 1503 PROC_LOCK(p); 1504 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1505 SIGPROCMASK_PROC_LOCKED); 1506 td->td_pflags |= TDP_OLDMASK; 1507 1508 /* 1509 * Process signals now. Otherwise, we can get spurious wakeup 1510 * due to signal entered process queue, but delivered to other 1511 * thread. But sigsuspend should return only on signal 1512 * delivery. 1513 */ 1514 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1515 for (has_sig = 0; !has_sig;) { 1516 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1517 0) == 0) 1518 /* void */; 1519 thread_suspend_check(0); 1520 mtx_lock(&p->p_sigacts->ps_mtx); 1521 while ((sig = cursig(td)) != 0) 1522 has_sig += postsig(sig); 1523 mtx_unlock(&p->p_sigacts->ps_mtx); 1524 } 1525 PROC_UNLOCK(p); 1526 td->td_errno = EINTR; 1527 td->td_pflags |= TDP_NERRNO; 1528 return (EJUSTRETURN); 1529} 1530 1531#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1532/* 1533 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1534 * convention: libc stub passes mask, not pointer, to save a copyin. 1535 */ 1536#ifndef _SYS_SYSPROTO_H_ 1537struct osigsuspend_args { 1538 osigset_t mask; 1539}; 1540#endif 1541/* ARGSUSED */ 1542int 1543osigsuspend(td, uap) 1544 struct thread *td; 1545 struct osigsuspend_args *uap; 1546{ 1547 sigset_t mask; 1548 1549 OSIG2SIG(uap->mask, mask); 1550 return (kern_sigsuspend(td, mask)); 1551} 1552#endif /* COMPAT_43 */ 1553 1554#if defined(COMPAT_43) 1555#ifndef _SYS_SYSPROTO_H_ 1556struct osigstack_args { 1557 struct sigstack *nss; 1558 struct sigstack *oss; 1559}; 1560#endif 1561/* ARGSUSED */ 1562int 1563osigstack(td, uap) 1564 struct thread *td; 1565 register struct osigstack_args *uap; 1566{ 1567 struct sigstack nss, oss; 1568 int error = 0; 1569 1570 if (uap->nss != NULL) { 1571 error = copyin(uap->nss, &nss, sizeof(nss)); 1572 if (error) 1573 return (error); 1574 } 1575 oss.ss_sp = td->td_sigstk.ss_sp; 1576 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1577 if (uap->nss != NULL) { 1578 td->td_sigstk.ss_sp = nss.ss_sp; 1579 td->td_sigstk.ss_size = 0; 1580 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1581 td->td_pflags |= TDP_ALTSTACK; 1582 } 1583 if (uap->oss != NULL) 1584 error = copyout(&oss, uap->oss, sizeof(oss)); 1585 1586 return (error); 1587} 1588#endif /* COMPAT_43 */ 1589 1590#ifndef _SYS_SYSPROTO_H_ 1591struct sigaltstack_args { 1592 stack_t *ss; 1593 stack_t *oss; 1594}; 1595#endif 1596/* ARGSUSED */ 1597int 1598sys_sigaltstack(td, uap) 1599 struct thread *td; 1600 register struct sigaltstack_args *uap; 1601{ 1602 stack_t ss, oss; 1603 int error; 1604 1605 if (uap->ss != NULL) { 1606 error = copyin(uap->ss, &ss, sizeof(ss)); 1607 if (error) 1608 return (error); 1609 } 1610 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1611 (uap->oss != NULL) ? &oss : NULL); 1612 if (error) 1613 return (error); 1614 if (uap->oss != NULL) 1615 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1616 return (error); 1617} 1618 1619int 1620kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1621{ 1622 struct proc *p = td->td_proc; 1623 int oonstack; 1624 1625 oonstack = sigonstack(cpu_getstack(td)); 1626 1627 if (oss != NULL) { 1628 *oss = td->td_sigstk; 1629 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1630 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1631 } 1632 1633 if (ss != NULL) { 1634 if (oonstack) 1635 return (EPERM); 1636 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1637 return (EINVAL); 1638 if (!(ss->ss_flags & SS_DISABLE)) { 1639 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1640 return (ENOMEM); 1641 1642 td->td_sigstk = *ss; 1643 td->td_pflags |= TDP_ALTSTACK; 1644 } else { 1645 td->td_pflags &= ~TDP_ALTSTACK; 1646 } 1647 } 1648 return (0); 1649} 1650 1651/* 1652 * Common code for kill process group/broadcast kill. 1653 * cp is calling process. 1654 */ 1655static int 1656killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1657{ 1658 struct proc *p; 1659 struct pgrp *pgrp; 1660 int err; 1661 int ret; 1662 1663 ret = ESRCH; 1664 if (all) { 1665 /* 1666 * broadcast 1667 */ 1668 sx_slock(&allproc_lock); 1669 FOREACH_PROC_IN_SYSTEM(p) { 1670 PROC_LOCK(p); 1671 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1672 p == td->td_proc || p->p_state == PRS_NEW) { 1673 PROC_UNLOCK(p); 1674 continue; 1675 } 1676 err = p_cansignal(td, p, sig); 1677 if (err == 0) { 1678 if (sig) 1679 pksignal(p, sig, ksi); 1680 ret = err; 1681 } 1682 else if (ret == ESRCH) 1683 ret = err; 1684 PROC_UNLOCK(p); 1685 } 1686 sx_sunlock(&allproc_lock); 1687 } else { 1688 sx_slock(&proctree_lock); 1689 if (pgid == 0) { 1690 /* 1691 * zero pgid means send to my process group. 1692 */ 1693 pgrp = td->td_proc->p_pgrp; 1694 PGRP_LOCK(pgrp); 1695 } else { 1696 pgrp = pgfind(pgid); 1697 if (pgrp == NULL) { 1698 sx_sunlock(&proctree_lock); 1699 return (ESRCH); 1700 } 1701 } 1702 sx_sunlock(&proctree_lock); 1703 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1704 PROC_LOCK(p); 1705 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1706 p->p_state == PRS_NEW) { 1707 PROC_UNLOCK(p); 1708 continue; 1709 } 1710 err = p_cansignal(td, p, sig); 1711 if (err == 0) { 1712 if (sig) 1713 pksignal(p, sig, ksi); 1714 ret = err; 1715 } 1716 else if (ret == ESRCH) 1717 ret = err; 1718 PROC_UNLOCK(p); 1719 } 1720 PGRP_UNLOCK(pgrp); 1721 } 1722 return (ret); 1723} 1724 1725#ifndef _SYS_SYSPROTO_H_ 1726struct kill_args { 1727 int pid; 1728 int signum; 1729}; 1730#endif 1731/* ARGSUSED */ 1732int 1733sys_kill(struct thread *td, struct kill_args *uap) 1734{ 1735 ksiginfo_t ksi; 1736 struct proc *p; 1737 int error; 1738 1739 /* 1740 * A process in capability mode can send signals only to himself. 1741 * The main rationale behind this is that abort(3) is implemented as 1742 * kill(getpid(), SIGABRT). 1743 */ 1744 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1745 return (ECAPMODE); 1746 1747 AUDIT_ARG_SIGNUM(uap->signum); 1748 AUDIT_ARG_PID(uap->pid); 1749 if ((u_int)uap->signum > _SIG_MAXSIG) 1750 return (EINVAL); 1751 1752 ksiginfo_init(&ksi); 1753 ksi.ksi_signo = uap->signum; 1754 ksi.ksi_code = SI_USER; 1755 ksi.ksi_pid = td->td_proc->p_pid; 1756 ksi.ksi_uid = td->td_ucred->cr_ruid; 1757 1758 if (uap->pid > 0) { 1759 /* kill single process */ 1760 if ((p = pfind(uap->pid)) == NULL) { 1761 if ((p = zpfind(uap->pid)) == NULL) 1762 return (ESRCH); 1763 } 1764 AUDIT_ARG_PROCESS(p); 1765 error = p_cansignal(td, p, uap->signum); 1766 if (error == 0 && uap->signum) 1767 pksignal(p, uap->signum, &ksi); 1768 PROC_UNLOCK(p); 1769 return (error); 1770 } 1771 switch (uap->pid) { 1772 case -1: /* broadcast signal */ 1773 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1774 case 0: /* signal own process group */ 1775 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1776 default: /* negative explicit process group */ 1777 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1778 } 1779 /* NOTREACHED */ 1780} 1781 1782int 1783sys_pdkill(td, uap) 1784 struct thread *td; 1785 struct pdkill_args *uap; 1786{ 1787#ifdef PROCDESC 1788 struct proc *p; 1789 cap_rights_t rights; 1790 int error; 1791 1792 AUDIT_ARG_SIGNUM(uap->signum); 1793 AUDIT_ARG_FD(uap->fd); 1794 if ((u_int)uap->signum > _SIG_MAXSIG) 1795 return (EINVAL); 1796 1797 error = procdesc_find(td, uap->fd, 1798 cap_rights_init(&rights, CAP_PDKILL), &p); 1799 if (error) 1800 return (error); 1801 AUDIT_ARG_PROCESS(p); 1802 error = p_cansignal(td, p, uap->signum); 1803 if (error == 0 && uap->signum) 1804 kern_psignal(p, uap->signum); 1805 PROC_UNLOCK(p); 1806 return (error); 1807#else 1808 return (ENOSYS); 1809#endif 1810} 1811 1812#if defined(COMPAT_43) 1813#ifndef _SYS_SYSPROTO_H_ 1814struct okillpg_args { 1815 int pgid; 1816 int signum; 1817}; 1818#endif 1819/* ARGSUSED */ 1820int 1821okillpg(struct thread *td, struct okillpg_args *uap) 1822{ 1823 ksiginfo_t ksi; 1824 1825 AUDIT_ARG_SIGNUM(uap->signum); 1826 AUDIT_ARG_PID(uap->pgid); 1827 if ((u_int)uap->signum > _SIG_MAXSIG) 1828 return (EINVAL); 1829 1830 ksiginfo_init(&ksi); 1831 ksi.ksi_signo = uap->signum; 1832 ksi.ksi_code = SI_USER; 1833 ksi.ksi_pid = td->td_proc->p_pid; 1834 ksi.ksi_uid = td->td_ucred->cr_ruid; 1835 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1836} 1837#endif /* COMPAT_43 */ 1838 1839#ifndef _SYS_SYSPROTO_H_ 1840struct sigqueue_args { 1841 pid_t pid; 1842 int signum; 1843 /* union sigval */ void *value; 1844}; 1845#endif 1846int 1847sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1848{ 1849 ksiginfo_t ksi; 1850 struct proc *p; 1851 int error; 1852 1853 if ((u_int)uap->signum > _SIG_MAXSIG) 1854 return (EINVAL); 1855 1856 /* 1857 * Specification says sigqueue can only send signal to 1858 * single process. 1859 */ 1860 if (uap->pid <= 0) 1861 return (EINVAL); 1862 1863 if ((p = pfind(uap->pid)) == NULL) { 1864 if ((p = zpfind(uap->pid)) == NULL) 1865 return (ESRCH); 1866 } 1867 error = p_cansignal(td, p, uap->signum); 1868 if (error == 0 && uap->signum != 0) { 1869 ksiginfo_init(&ksi); 1870 ksi.ksi_flags = KSI_SIGQ; 1871 ksi.ksi_signo = uap->signum; 1872 ksi.ksi_code = SI_QUEUE; 1873 ksi.ksi_pid = td->td_proc->p_pid; 1874 ksi.ksi_uid = td->td_ucred->cr_ruid; 1875 ksi.ksi_value.sival_ptr = uap->value; 1876 error = pksignal(p, ksi.ksi_signo, &ksi); 1877 } 1878 PROC_UNLOCK(p); 1879 return (error); 1880} 1881 1882/* 1883 * Send a signal to a process group. 1884 */ 1885void 1886gsignal(int pgid, int sig, ksiginfo_t *ksi) 1887{ 1888 struct pgrp *pgrp; 1889 1890 if (pgid != 0) { 1891 sx_slock(&proctree_lock); 1892 pgrp = pgfind(pgid); 1893 sx_sunlock(&proctree_lock); 1894 if (pgrp != NULL) { 1895 pgsignal(pgrp, sig, 0, ksi); 1896 PGRP_UNLOCK(pgrp); 1897 } 1898 } 1899} 1900 1901/* 1902 * Send a signal to a process group. If checktty is 1, 1903 * limit to members which have a controlling terminal. 1904 */ 1905void 1906pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1907{ 1908 struct proc *p; 1909 1910 if (pgrp) { 1911 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1912 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1913 PROC_LOCK(p); 1914 if (p->p_state == PRS_NORMAL && 1915 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1916 pksignal(p, sig, ksi); 1917 PROC_UNLOCK(p); 1918 } 1919 } 1920} 1921 1922 1923/* 1924 * Recalculate the signal mask and reset the signal disposition after 1925 * usermode frame for delivery is formed. Should be called after 1926 * mach-specific routine, because sysent->sv_sendsig() needs correct 1927 * ps_siginfo and signal mask. 1928 */ 1929static void 1930postsig_done(int sig, struct thread *td, struct sigacts *ps) 1931{ 1932 sigset_t mask; 1933 1934 mtx_assert(&ps->ps_mtx, MA_OWNED); 1935 td->td_ru.ru_nsignals++; 1936 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1937 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1938 SIGADDSET(mask, sig); 1939 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1940 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1941 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1942 sigdflt(ps, sig); 1943} 1944 1945 1946/* 1947 * Send a signal caused by a trap to the current thread. If it will be 1948 * caught immediately, deliver it with correct code. Otherwise, post it 1949 * normally. 1950 */ 1951void 1952trapsignal(struct thread *td, ksiginfo_t *ksi) 1953{ 1954 struct sigacts *ps; 1955 struct proc *p; 1956 int sig; 1957 int code; 1958 1959 p = td->td_proc; 1960 sig = ksi->ksi_signo; 1961 code = ksi->ksi_code; 1962 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1963 1964 PROC_LOCK(p); 1965 ps = p->p_sigacts; 1966 mtx_lock(&ps->ps_mtx); 1967 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1968 !SIGISMEMBER(td->td_sigmask, sig)) { 1969#ifdef KTRACE 1970 if (KTRPOINT(curthread, KTR_PSIG)) 1971 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1972 &td->td_sigmask, code); 1973#endif 1974 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1975 ksi, &td->td_sigmask); 1976 postsig_done(sig, td, ps); 1977 mtx_unlock(&ps->ps_mtx); 1978 } else { 1979 /* 1980 * Avoid a possible infinite loop if the thread 1981 * masking the signal or process is ignoring the 1982 * signal. 1983 */ 1984 if (kern_forcesigexit && 1985 (SIGISMEMBER(td->td_sigmask, sig) || 1986 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1987 SIGDELSET(td->td_sigmask, sig); 1988 SIGDELSET(ps->ps_sigcatch, sig); 1989 SIGDELSET(ps->ps_sigignore, sig); 1990 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 1991 } 1992 mtx_unlock(&ps->ps_mtx); 1993 p->p_code = code; /* XXX for core dump/debugger */ 1994 p->p_sig = sig; /* XXX to verify code */ 1995 tdsendsignal(p, td, sig, ksi); 1996 } 1997 PROC_UNLOCK(p); 1998} 1999 2000static struct thread * 2001sigtd(struct proc *p, int sig, int prop) 2002{ 2003 struct thread *td, *signal_td; 2004 2005 PROC_LOCK_ASSERT(p, MA_OWNED); 2006 2007 /* 2008 * Check if current thread can handle the signal without 2009 * switching context to another thread. 2010 */ 2011 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2012 return (curthread); 2013 signal_td = NULL; 2014 FOREACH_THREAD_IN_PROC(p, td) { 2015 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2016 signal_td = td; 2017 break; 2018 } 2019 } 2020 if (signal_td == NULL) 2021 signal_td = FIRST_THREAD_IN_PROC(p); 2022 return (signal_td); 2023} 2024 2025/* 2026 * Send the signal to the process. If the signal has an action, the action 2027 * is usually performed by the target process rather than the caller; we add 2028 * the signal to the set of pending signals for the process. 2029 * 2030 * Exceptions: 2031 * o When a stop signal is sent to a sleeping process that takes the 2032 * default action, the process is stopped without awakening it. 2033 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2034 * regardless of the signal action (eg, blocked or ignored). 2035 * 2036 * Other ignored signals are discarded immediately. 2037 * 2038 * NB: This function may be entered from the debugger via the "kill" DDB 2039 * command. There is little that can be done to mitigate the possibly messy 2040 * side effects of this unwise possibility. 2041 */ 2042void 2043kern_psignal(struct proc *p, int sig) 2044{ 2045 ksiginfo_t ksi; 2046 2047 ksiginfo_init(&ksi); 2048 ksi.ksi_signo = sig; 2049 ksi.ksi_code = SI_KERNEL; 2050 (void) tdsendsignal(p, NULL, sig, &ksi); 2051} 2052 2053int 2054pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2055{ 2056 2057 return (tdsendsignal(p, NULL, sig, ksi)); 2058} 2059 2060/* Utility function for finding a thread to send signal event to. */ 2061int 2062sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2063{ 2064 struct thread *td; 2065 2066 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2067 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2068 if (td == NULL) 2069 return (ESRCH); 2070 *ttd = td; 2071 } else { 2072 *ttd = NULL; 2073 PROC_LOCK(p); 2074 } 2075 return (0); 2076} 2077 2078void 2079tdsignal(struct thread *td, int sig) 2080{ 2081 ksiginfo_t ksi; 2082 2083 ksiginfo_init(&ksi); 2084 ksi.ksi_signo = sig; 2085 ksi.ksi_code = SI_KERNEL; 2086 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2087} 2088 2089void 2090tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2091{ 2092 2093 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2094} 2095 2096int 2097tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2098{ 2099 sig_t action; 2100 sigqueue_t *sigqueue; 2101 int prop; 2102 struct sigacts *ps; 2103 int intrval; 2104 int ret = 0; 2105 int wakeup_swapper; 2106 2107 MPASS(td == NULL || p == td->td_proc); 2108 PROC_LOCK_ASSERT(p, MA_OWNED); 2109 2110 if (!_SIG_VALID(sig)) 2111 panic("%s(): invalid signal %d", __func__, sig); 2112 2113 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2114 2115 /* 2116 * IEEE Std 1003.1-2001: return success when killing a zombie. 2117 */ 2118 if (p->p_state == PRS_ZOMBIE) { 2119 if (ksi && (ksi->ksi_flags & KSI_INS)) 2120 ksiginfo_tryfree(ksi); 2121 return (ret); 2122 } 2123 2124 ps = p->p_sigacts; 2125 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2126 prop = sigprop(sig); 2127 2128 if (td == NULL) { 2129 td = sigtd(p, sig, prop); 2130 sigqueue = &p->p_sigqueue; 2131 } else 2132 sigqueue = &td->td_sigqueue; 2133 2134 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2135 2136 /* 2137 * If the signal is being ignored, 2138 * then we forget about it immediately. 2139 * (Note: we don't set SIGCONT in ps_sigignore, 2140 * and if it is set to SIG_IGN, 2141 * action will be SIG_DFL here.) 2142 */ 2143 mtx_lock(&ps->ps_mtx); 2144 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2145 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2146 2147 mtx_unlock(&ps->ps_mtx); 2148 if (ksi && (ksi->ksi_flags & KSI_INS)) 2149 ksiginfo_tryfree(ksi); 2150 return (ret); 2151 } 2152 if (SIGISMEMBER(td->td_sigmask, sig)) 2153 action = SIG_HOLD; 2154 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2155 action = SIG_CATCH; 2156 else 2157 action = SIG_DFL; 2158 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2159 intrval = EINTR; 2160 else 2161 intrval = ERESTART; 2162 mtx_unlock(&ps->ps_mtx); 2163 2164 if (prop & SA_CONT) 2165 sigqueue_delete_stopmask_proc(p); 2166 else if (prop & SA_STOP) { 2167 /* 2168 * If sending a tty stop signal to a member of an orphaned 2169 * process group, discard the signal here if the action 2170 * is default; don't stop the process below if sleeping, 2171 * and don't clear any pending SIGCONT. 2172 */ 2173 if ((prop & SA_TTYSTOP) && 2174 (p->p_pgrp->pg_jobc == 0) && 2175 (action == SIG_DFL)) { 2176 if (ksi && (ksi->ksi_flags & KSI_INS)) 2177 ksiginfo_tryfree(ksi); 2178 return (ret); 2179 } 2180 sigqueue_delete_proc(p, SIGCONT); 2181 if (p->p_flag & P_CONTINUED) { 2182 p->p_flag &= ~P_CONTINUED; 2183 PROC_LOCK(p->p_pptr); 2184 sigqueue_take(p->p_ksi); 2185 PROC_UNLOCK(p->p_pptr); 2186 } 2187 } 2188 2189 ret = sigqueue_add(sigqueue, sig, ksi); 2190 if (ret != 0) 2191 return (ret); 2192 signotify(td); 2193 /* 2194 * Defer further processing for signals which are held, 2195 * except that stopped processes must be continued by SIGCONT. 2196 */ 2197 if (action == SIG_HOLD && 2198 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2199 return (ret); 2200 2201 /* SIGKILL: Remove procfs STOPEVENTs. */ 2202 if (sig == SIGKILL) { 2203 /* from procfs_ioctl.c: PIOCBIC */ 2204 p->p_stops = 0; 2205 /* from procfs_ioctl.c: PIOCCONT */ 2206 p->p_step = 0; 2207 wakeup(&p->p_step); 2208 } 2209 /* 2210 * Some signals have a process-wide effect and a per-thread 2211 * component. Most processing occurs when the process next 2212 * tries to cross the user boundary, however there are some 2213 * times when processing needs to be done immediately, such as 2214 * waking up threads so that they can cross the user boundary. 2215 * We try to do the per-process part here. 2216 */ 2217 if (P_SHOULDSTOP(p)) { 2218 KASSERT(!(p->p_flag & P_WEXIT), 2219 ("signal to stopped but exiting process")); 2220 if (sig == SIGKILL) { 2221 /* 2222 * If traced process is already stopped, 2223 * then no further action is necessary. 2224 */ 2225 if (p->p_flag & P_TRACED) 2226 goto out; 2227 /* 2228 * SIGKILL sets process running. 2229 * It will die elsewhere. 2230 * All threads must be restarted. 2231 */ 2232 p->p_flag &= ~P_STOPPED_SIG; 2233 goto runfast; 2234 } 2235 2236 if (prop & SA_CONT) { 2237 /* 2238 * If traced process is already stopped, 2239 * then no further action is necessary. 2240 */ 2241 if (p->p_flag & P_TRACED) 2242 goto out; 2243 /* 2244 * If SIGCONT is default (or ignored), we continue the 2245 * process but don't leave the signal in sigqueue as 2246 * it has no further action. If SIGCONT is held, we 2247 * continue the process and leave the signal in 2248 * sigqueue. If the process catches SIGCONT, let it 2249 * handle the signal itself. If it isn't waiting on 2250 * an event, it goes back to run state. 2251 * Otherwise, process goes back to sleep state. 2252 */ 2253 p->p_flag &= ~P_STOPPED_SIG; 2254 PROC_SLOCK(p); 2255 if (p->p_numthreads == p->p_suspcount) { 2256 PROC_SUNLOCK(p); 2257 p->p_flag |= P_CONTINUED; 2258 p->p_xstat = SIGCONT; 2259 PROC_LOCK(p->p_pptr); 2260 childproc_continued(p); 2261 PROC_UNLOCK(p->p_pptr); 2262 PROC_SLOCK(p); 2263 } 2264 if (action == SIG_DFL) { 2265 thread_unsuspend(p); 2266 PROC_SUNLOCK(p); 2267 sigqueue_delete(sigqueue, sig); 2268 goto out; 2269 } 2270 if (action == SIG_CATCH) { 2271 /* 2272 * The process wants to catch it so it needs 2273 * to run at least one thread, but which one? 2274 */ 2275 PROC_SUNLOCK(p); 2276 goto runfast; 2277 } 2278 /* 2279 * The signal is not ignored or caught. 2280 */ 2281 thread_unsuspend(p); 2282 PROC_SUNLOCK(p); 2283 goto out; 2284 } 2285 2286 if (prop & SA_STOP) { 2287 /* 2288 * If traced process is already stopped, 2289 * then no further action is necessary. 2290 */ 2291 if (p->p_flag & P_TRACED) 2292 goto out; 2293 /* 2294 * Already stopped, don't need to stop again 2295 * (If we did the shell could get confused). 2296 * Just make sure the signal STOP bit set. 2297 */ 2298 p->p_flag |= P_STOPPED_SIG; 2299 sigqueue_delete(sigqueue, sig); 2300 goto out; 2301 } 2302 2303 /* 2304 * All other kinds of signals: 2305 * If a thread is sleeping interruptibly, simulate a 2306 * wakeup so that when it is continued it will be made 2307 * runnable and can look at the signal. However, don't make 2308 * the PROCESS runnable, leave it stopped. 2309 * It may run a bit until it hits a thread_suspend_check(). 2310 */ 2311 wakeup_swapper = 0; 2312 PROC_SLOCK(p); 2313 thread_lock(td); 2314 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2315 wakeup_swapper = sleepq_abort(td, intrval); 2316 thread_unlock(td); 2317 PROC_SUNLOCK(p); 2318 if (wakeup_swapper) 2319 kick_proc0(); 2320 goto out; 2321 /* 2322 * Mutexes are short lived. Threads waiting on them will 2323 * hit thread_suspend_check() soon. 2324 */ 2325 } else if (p->p_state == PRS_NORMAL) { 2326 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2327 tdsigwakeup(td, sig, action, intrval); 2328 goto out; 2329 } 2330 2331 MPASS(action == SIG_DFL); 2332 2333 if (prop & SA_STOP) { 2334 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2335 goto out; 2336 p->p_flag |= P_STOPPED_SIG; 2337 p->p_xstat = sig; 2338 PROC_SLOCK(p); 2339 sig_suspend_threads(td, p, 1); 2340 if (p->p_numthreads == p->p_suspcount) { 2341 /* 2342 * only thread sending signal to another 2343 * process can reach here, if thread is sending 2344 * signal to its process, because thread does 2345 * not suspend itself here, p_numthreads 2346 * should never be equal to p_suspcount. 2347 */ 2348 thread_stopped(p); 2349 PROC_SUNLOCK(p); 2350 sigqueue_delete_proc(p, p->p_xstat); 2351 } else 2352 PROC_SUNLOCK(p); 2353 goto out; 2354 } 2355 } else { 2356 /* Not in "NORMAL" state. discard the signal. */ 2357 sigqueue_delete(sigqueue, sig); 2358 goto out; 2359 } 2360 2361 /* 2362 * The process is not stopped so we need to apply the signal to all the 2363 * running threads. 2364 */ 2365runfast: 2366 tdsigwakeup(td, sig, action, intrval); 2367 PROC_SLOCK(p); 2368 thread_unsuspend(p); 2369 PROC_SUNLOCK(p); 2370out: 2371 /* If we jump here, proc slock should not be owned. */ 2372 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2373 return (ret); 2374} 2375 2376/* 2377 * The force of a signal has been directed against a single 2378 * thread. We need to see what we can do about knocking it 2379 * out of any sleep it may be in etc. 2380 */ 2381static void 2382tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2383{ 2384 struct proc *p = td->td_proc; 2385 register int prop; 2386 int wakeup_swapper; 2387 2388 wakeup_swapper = 0; 2389 PROC_LOCK_ASSERT(p, MA_OWNED); 2390 prop = sigprop(sig); 2391 2392 PROC_SLOCK(p); 2393 thread_lock(td); 2394 /* 2395 * Bring the priority of a thread up if we want it to get 2396 * killed in this lifetime. Be careful to avoid bumping the 2397 * priority of the idle thread, since we still allow to signal 2398 * kernel processes. 2399 */ 2400 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2401 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2402 sched_prio(td, PUSER); 2403 if (TD_ON_SLEEPQ(td)) { 2404 /* 2405 * If thread is sleeping uninterruptibly 2406 * we can't interrupt the sleep... the signal will 2407 * be noticed when the process returns through 2408 * trap() or syscall(). 2409 */ 2410 if ((td->td_flags & TDF_SINTR) == 0) 2411 goto out; 2412 /* 2413 * If SIGCONT is default (or ignored) and process is 2414 * asleep, we are finished; the process should not 2415 * be awakened. 2416 */ 2417 if ((prop & SA_CONT) && action == SIG_DFL) { 2418 thread_unlock(td); 2419 PROC_SUNLOCK(p); 2420 sigqueue_delete(&p->p_sigqueue, sig); 2421 /* 2422 * It may be on either list in this state. 2423 * Remove from both for now. 2424 */ 2425 sigqueue_delete(&td->td_sigqueue, sig); 2426 return; 2427 } 2428 2429 /* 2430 * Don't awaken a sleeping thread for SIGSTOP if the 2431 * STOP signal is deferred. 2432 */ 2433 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2434 goto out; 2435 2436 /* 2437 * Give low priority threads a better chance to run. 2438 */ 2439 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2440 sched_prio(td, PUSER); 2441 2442 wakeup_swapper = sleepq_abort(td, intrval); 2443 } else { 2444 /* 2445 * Other states do nothing with the signal immediately, 2446 * other than kicking ourselves if we are running. 2447 * It will either never be noticed, or noticed very soon. 2448 */ 2449#ifdef SMP 2450 if (TD_IS_RUNNING(td) && td != curthread) 2451 forward_signal(td); 2452#endif 2453 } 2454out: 2455 PROC_SUNLOCK(p); 2456 thread_unlock(td); 2457 if (wakeup_swapper) 2458 kick_proc0(); 2459} 2460 2461static void 2462sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2463{ 2464 struct thread *td2; 2465 2466 PROC_LOCK_ASSERT(p, MA_OWNED); 2467 PROC_SLOCK_ASSERT(p, MA_OWNED); 2468 2469 FOREACH_THREAD_IN_PROC(p, td2) { 2470 thread_lock(td2); 2471 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2472 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2473 (td2->td_flags & TDF_SINTR)) { 2474 if (td2->td_flags & TDF_SBDRY) { 2475 /* 2476 * Once a thread is asleep with 2477 * TDF_SBDRY set, it should never 2478 * become suspended due to this check. 2479 */ 2480 KASSERT(!TD_IS_SUSPENDED(td2), 2481 ("thread with deferred stops suspended")); 2482 } else if (!TD_IS_SUSPENDED(td2)) { 2483 thread_suspend_one(td2); 2484 } 2485 } else if (!TD_IS_SUSPENDED(td2)) { 2486 if (sending || td != td2) 2487 td2->td_flags |= TDF_ASTPENDING; 2488#ifdef SMP 2489 if (TD_IS_RUNNING(td2) && td2 != td) 2490 forward_signal(td2); 2491#endif 2492 } 2493 thread_unlock(td2); 2494 } 2495} 2496 2497/* 2498 * Stop the process for an event deemed interesting to the debugger. If si is 2499 * non-NULL, this is a signal exchange; the new signal requested by the 2500 * debugger will be returned for handling. If si is NULL, this is some other 2501 * type of interesting event. The debugger may request a signal be delivered in 2502 * that case as well, however it will be deferred until it can be handled. 2503 */ 2504int 2505ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2506{ 2507 struct proc *p = td->td_proc; 2508 struct thread *td2; 2509 ksiginfo_t ksi; 2510 int prop; 2511 2512 PROC_LOCK_ASSERT(p, MA_OWNED); 2513 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2514 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2515 &p->p_mtx.lock_object, "Stopping for traced signal"); 2516 2517 td->td_xsig = sig; 2518 2519 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2520 td->td_dbgflags |= TDB_XSIG; 2521 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2522 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2523 PROC_SLOCK(p); 2524 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2525 if (P_KILLED(p)) { 2526 /* 2527 * Ensure that, if we've been PT_KILLed, the 2528 * exit status reflects that. Another thread 2529 * may also be in ptracestop(), having just 2530 * received the SIGKILL, but this thread was 2531 * unsuspended first. 2532 */ 2533 td->td_dbgflags &= ~TDB_XSIG; 2534 td->td_xsig = SIGKILL; 2535 p->p_ptevents = 0; 2536 break; 2537 } 2538 if (p->p_flag & P_SINGLE_EXIT && 2539 !(td->td_dbgflags & TDB_EXIT)) { 2540 /* 2541 * Ignore ptrace stops except for thread exit 2542 * events when the process exits. 2543 */ 2544 td->td_dbgflags &= ~TDB_XSIG; 2545 PROC_SUNLOCK(p); 2546 return (0); 2547 } 2548 2549 /* 2550 * Make wait(2) work. Ensure that right after the 2551 * attach, the thread which was decided to become the 2552 * leader of attach gets reported to the waiter. 2553 * Otherwise, just avoid overwriting another thread's 2554 * assignment to p_xthread. If another thread has 2555 * already set p_xthread, the current thread will get 2556 * a chance to report itself upon the next iteration. 2557 */ 2558 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2559 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2560 p->p_xthread == NULL)) { 2561 p->p_xstat = sig; 2562 p->p_xthread = td; 2563 td->td_dbgflags &= ~TDB_FSTP; 2564 p->p_flag2 &= ~P2_PTRACE_FSTP; 2565 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2566 sig_suspend_threads(td, p, 0); 2567 } 2568 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2569 td->td_dbgflags &= ~TDB_STOPATFORK; 2570 cv_broadcast(&p->p_dbgwait); 2571 } 2572stopme: 2573 thread_suspend_switch(td, p); 2574 if (p->p_xthread == td) 2575 p->p_xthread = NULL; 2576 if (!(p->p_flag & P_TRACED)) 2577 break; 2578 if (td->td_dbgflags & TDB_SUSPEND) { 2579 if (p->p_flag & P_SINGLE_EXIT) 2580 break; 2581 goto stopme; 2582 } 2583 } 2584 PROC_SUNLOCK(p); 2585 } 2586 2587 if (si != NULL && sig == td->td_xsig) { 2588 /* Parent wants us to take the original signal unchanged. */ 2589 si->ksi_flags |= KSI_HEAD; 2590 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2591 si->ksi_signo = 0; 2592 } else if (td->td_xsig != 0) { 2593 /* 2594 * If parent wants us to take a new signal, then it will leave 2595 * it in td->td_xsig; otherwise we just look for signals again. 2596 */ 2597 ksiginfo_init(&ksi); 2598 ksi.ksi_signo = td->td_xsig; 2599 ksi.ksi_flags |= KSI_PTRACE; 2600 prop = sigprop(td->td_xsig); 2601 td2 = sigtd(p, td->td_xsig, prop); 2602 tdsendsignal(p, td2, td->td_xsig, &ksi); 2603 if (td != td2) 2604 return (0); 2605 } 2606 2607 return (td->td_xsig); 2608} 2609 2610static void 2611reschedule_signals(struct proc *p, sigset_t block, int flags) 2612{ 2613 struct sigacts *ps; 2614 struct thread *td; 2615 int sig; 2616 2617 PROC_LOCK_ASSERT(p, MA_OWNED); 2618 ps = p->p_sigacts; 2619 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2620 MA_OWNED : MA_NOTOWNED); 2621 if (SIGISEMPTY(p->p_siglist)) 2622 return; 2623 SIGSETAND(block, p->p_siglist); 2624 while ((sig = sig_ffs(&block)) != 0) { 2625 SIGDELSET(block, sig); 2626 td = sigtd(p, sig, 0); 2627 signotify(td); 2628 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2629 mtx_lock(&ps->ps_mtx); 2630 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2631 tdsigwakeup(td, sig, SIG_CATCH, 2632 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2633 ERESTART)); 2634 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2635 mtx_unlock(&ps->ps_mtx); 2636 } 2637} 2638 2639void 2640tdsigcleanup(struct thread *td) 2641{ 2642 struct proc *p; 2643 sigset_t unblocked; 2644 2645 p = td->td_proc; 2646 PROC_LOCK_ASSERT(p, MA_OWNED); 2647 2648 sigqueue_flush(&td->td_sigqueue); 2649 if (p->p_numthreads == 1) 2650 return; 2651 2652 /* 2653 * Since we cannot handle signals, notify signal post code 2654 * about this by filling the sigmask. 2655 * 2656 * Also, if needed, wake up thread(s) that do not block the 2657 * same signals as the exiting thread, since the thread might 2658 * have been selected for delivery and woken up. 2659 */ 2660 SIGFILLSET(unblocked); 2661 SIGSETNAND(unblocked, td->td_sigmask); 2662 SIGFILLSET(td->td_sigmask); 2663 reschedule_signals(p, unblocked, 0); 2664 2665} 2666 2667/* 2668 * Defer the delivery of SIGSTOP for the current thread. Returns true 2669 * if stops were deferred and false if they were already deferred. 2670 */ 2671int 2672sigdeferstop(void) 2673{ 2674 struct thread *td; 2675 2676 td = curthread; 2677 if (td->td_flags & TDF_SBDRY) 2678 return (0); 2679 thread_lock(td); 2680 td->td_flags |= TDF_SBDRY; 2681 thread_unlock(td); 2682 return (1); 2683} 2684 2685/* 2686 * Permit the delivery of SIGSTOP for the current thread. This does 2687 * not immediately suspend if a stop was posted. Instead, the thread 2688 * will suspend either via ast() or a subsequent interruptible sleep. 2689 */ 2690int 2691sigallowstop(void) 2692{ 2693 struct thread *td; 2694 int prev; 2695 2696 td = curthread; 2697 thread_lock(td); 2698 prev = (td->td_flags & TDF_SBDRY) != 0; 2699 td->td_flags &= ~TDF_SBDRY; 2700 thread_unlock(td); 2701 return (prev); 2702} 2703 2704/* 2705 * If the current process has received a signal (should be caught or cause 2706 * termination, should interrupt current syscall), return the signal number. 2707 * Stop signals with default action are processed immediately, then cleared; 2708 * they aren't returned. This is checked after each entry to the system for 2709 * a syscall or trap (though this can usually be done without calling issignal 2710 * by checking the pending signal masks in cursig.) The normal call 2711 * sequence is 2712 * 2713 * while (sig = cursig(curthread)) 2714 * postsig(sig); 2715 */ 2716static int 2717issignal(struct thread *td) 2718{ 2719 struct proc *p; 2720 struct sigacts *ps; 2721 struct sigqueue *queue; 2722 sigset_t sigpending; 2723 int sig, prop; 2724 2725 p = td->td_proc; 2726 ps = p->p_sigacts; 2727 mtx_assert(&ps->ps_mtx, MA_OWNED); 2728 PROC_LOCK_ASSERT(p, MA_OWNED); 2729 for (;;) { 2730 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2731 2732 sigpending = td->td_sigqueue.sq_signals; 2733 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2734 SIGSETNAND(sigpending, td->td_sigmask); 2735 2736 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2737 SIG_STOPSIGMASK(sigpending); 2738 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2739 return (0); 2740 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2741 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2742 SIGISMEMBER(sigpending, SIGSTOP)) { 2743 /* 2744 * If debugger just attached, always consume 2745 * SIGSTOP from ptrace(PT_ATTACH) first, to 2746 * execute the debugger attach ritual in 2747 * order. 2748 */ 2749 sig = SIGSTOP; 2750 td->td_dbgflags |= TDB_FSTP; 2751 } else { 2752 sig = sig_ffs(&sigpending); 2753 } 2754 2755 if (p->p_stops & S_SIG) { 2756 mtx_unlock(&ps->ps_mtx); 2757 stopevent(p, S_SIG, sig); 2758 mtx_lock(&ps->ps_mtx); 2759 } 2760 2761 /* 2762 * We should see pending but ignored signals 2763 * only if P_TRACED was on when they were posted. 2764 */ 2765 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2766 sigqueue_delete(&td->td_sigqueue, sig); 2767 sigqueue_delete(&p->p_sigqueue, sig); 2768 continue; 2769 } 2770 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2771 /* 2772 * If traced, always stop. 2773 * Remove old signal from queue before the stop. 2774 * XXX shrug off debugger, it causes siginfo to 2775 * be thrown away. 2776 */ 2777 queue = &td->td_sigqueue; 2778 td->td_dbgksi.ksi_signo = 0; 2779 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2780 queue = &p->p_sigqueue; 2781 sigqueue_get(queue, sig, &td->td_dbgksi); 2782 } 2783 2784 mtx_unlock(&ps->ps_mtx); 2785 sig = ptracestop(td, sig, &td->td_dbgksi); 2786 mtx_lock(&ps->ps_mtx); 2787 2788 /* 2789 * Keep looking if the debugger discarded the signal 2790 * or replaced it with a masked signal. 2791 * 2792 * If the traced bit got turned off, go back up 2793 * to the top to rescan signals. This ensures 2794 * that p_sig* and p_sigact are consistent. 2795 */ 2796 if (sig == 0 || (p->p_flag & P_TRACED) == 0) 2797 continue; 2798 } 2799 2800 prop = sigprop(sig); 2801 2802 /* 2803 * Decide whether the signal should be returned. 2804 * Return the signal's number, or fall through 2805 * to clear it from the pending mask. 2806 */ 2807 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2808 2809 case (intptr_t)SIG_DFL: 2810 /* 2811 * Don't take default actions on system processes. 2812 */ 2813 if (p->p_pid <= 1) { 2814#ifdef DIAGNOSTIC 2815 /* 2816 * Are you sure you want to ignore SIGSEGV 2817 * in init? XXX 2818 */ 2819 printf("Process (pid %lu) got signal %d\n", 2820 (u_long)p->p_pid, sig); 2821#endif 2822 break; /* == ignore */ 2823 } 2824 /* 2825 * If there is a pending stop signal to process with 2826 * default action, stop here, then clear the signal. 2827 * Traced or exiting processes should ignore stops. 2828 * Additionally, a member of an orphaned process group 2829 * should ignore tty stops. 2830 */ 2831 if (prop & SA_STOP) { 2832 if (p->p_flag & 2833 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2834 (p->p_pgrp->pg_jobc == 0 && 2835 prop & SA_TTYSTOP)) 2836 break; /* == ignore */ 2837 mtx_unlock(&ps->ps_mtx); 2838 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2839 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2840 sigqueue_delete(&td->td_sigqueue, sig); 2841 sigqueue_delete(&p->p_sigqueue, sig); 2842 p->p_flag |= P_STOPPED_SIG; 2843 p->p_xstat = sig; 2844 PROC_SLOCK(p); 2845 sig_suspend_threads(td, p, 0); 2846 thread_suspend_switch(td, p); 2847 PROC_SUNLOCK(p); 2848 mtx_lock(&ps->ps_mtx); 2849 goto next; 2850 } else if (prop & SA_IGNORE) { 2851 /* 2852 * Except for SIGCONT, shouldn't get here. 2853 * Default action is to ignore; drop it. 2854 */ 2855 break; /* == ignore */ 2856 } else 2857 return (sig); 2858 /*NOTREACHED*/ 2859 2860 case (intptr_t)SIG_IGN: 2861 /* 2862 * Masking above should prevent us ever trying 2863 * to take action on an ignored signal other 2864 * than SIGCONT, unless process is traced. 2865 */ 2866 if ((prop & SA_CONT) == 0 && 2867 (p->p_flag & P_TRACED) == 0) 2868 printf("issignal\n"); 2869 break; /* == ignore */ 2870 2871 default: 2872 /* 2873 * This signal has an action, let 2874 * postsig() process it. 2875 */ 2876 return (sig); 2877 } 2878 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2879 sigqueue_delete(&p->p_sigqueue, sig); 2880next:; 2881 } 2882 /* NOTREACHED */ 2883} 2884 2885void 2886thread_stopped(struct proc *p) 2887{ 2888 int n; 2889 2890 PROC_LOCK_ASSERT(p, MA_OWNED); 2891 PROC_SLOCK_ASSERT(p, MA_OWNED); 2892 n = p->p_suspcount; 2893 if (p == curproc) 2894 n++; 2895 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2896 PROC_SUNLOCK(p); 2897 p->p_flag &= ~P_WAITED; 2898 PROC_LOCK(p->p_pptr); 2899 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2900 CLD_TRAPPED : CLD_STOPPED); 2901 PROC_UNLOCK(p->p_pptr); 2902 PROC_SLOCK(p); 2903 } 2904} 2905 2906/* 2907 * Take the action for the specified signal 2908 * from the current set of pending signals. 2909 */ 2910int 2911postsig(sig) 2912 register int sig; 2913{ 2914 struct thread *td = curthread; 2915 register struct proc *p = td->td_proc; 2916 struct sigacts *ps; 2917 sig_t action; 2918 ksiginfo_t ksi; 2919 sigset_t returnmask; 2920 2921 KASSERT(sig != 0, ("postsig")); 2922 2923 PROC_LOCK_ASSERT(p, MA_OWNED); 2924 ps = p->p_sigacts; 2925 mtx_assert(&ps->ps_mtx, MA_OWNED); 2926 ksiginfo_init(&ksi); 2927 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2928 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2929 return (0); 2930 ksi.ksi_signo = sig; 2931 if (ksi.ksi_code == SI_TIMER) 2932 itimer_accept(p, ksi.ksi_timerid, &ksi); 2933 action = ps->ps_sigact[_SIG_IDX(sig)]; 2934#ifdef KTRACE 2935 if (KTRPOINT(td, KTR_PSIG)) 2936 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2937 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2938#endif 2939 if (p->p_stops & S_SIG) { 2940 mtx_unlock(&ps->ps_mtx); 2941 stopevent(p, S_SIG, sig); 2942 mtx_lock(&ps->ps_mtx); 2943 } 2944 2945 if (action == SIG_DFL) { 2946 /* 2947 * Default action, where the default is to kill 2948 * the process. (Other cases were ignored above.) 2949 */ 2950 mtx_unlock(&ps->ps_mtx); 2951 sigexit(td, sig); 2952 /* NOTREACHED */ 2953 } else { 2954 /* 2955 * If we get here, the signal must be caught. 2956 */ 2957 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2958 ("postsig action")); 2959 /* 2960 * Set the new mask value and also defer further 2961 * occurrences of this signal. 2962 * 2963 * Special case: user has done a sigsuspend. Here the 2964 * current mask is not of interest, but rather the 2965 * mask from before the sigsuspend is what we want 2966 * restored after the signal processing is completed. 2967 */ 2968 if (td->td_pflags & TDP_OLDMASK) { 2969 returnmask = td->td_oldsigmask; 2970 td->td_pflags &= ~TDP_OLDMASK; 2971 } else 2972 returnmask = td->td_sigmask; 2973 2974 if (p->p_sig == sig) { 2975 p->p_code = 0; 2976 p->p_sig = 0; 2977 } 2978 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2979 postsig_done(sig, td, ps); 2980 } 2981 return (1); 2982} 2983 2984/* 2985 * Kill the current process for stated reason. 2986 */ 2987void 2988killproc(p, why) 2989 struct proc *p; 2990 char *why; 2991{ 2992 2993 PROC_LOCK_ASSERT(p, MA_OWNED); 2994 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 2995 p->p_comm); 2996 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 2997 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 2998 p->p_flag |= P_WKILLED; 2999 kern_psignal(p, SIGKILL); 3000} 3001 3002/* 3003 * Force the current process to exit with the specified signal, dumping core 3004 * if appropriate. We bypass the normal tests for masked and caught signals, 3005 * allowing unrecoverable failures to terminate the process without changing 3006 * signal state. Mark the accounting record with the signal termination. 3007 * If dumping core, save the signal number for the debugger. Calls exit and 3008 * does not return. 3009 */ 3010void 3011sigexit(td, sig) 3012 struct thread *td; 3013 int sig; 3014{ 3015 struct proc *p = td->td_proc; 3016 3017 PROC_LOCK_ASSERT(p, MA_OWNED); 3018 p->p_acflag |= AXSIG; 3019 /* 3020 * We must be single-threading to generate a core dump. This 3021 * ensures that the registers in the core file are up-to-date. 3022 * Also, the ELF dump handler assumes that the thread list doesn't 3023 * change out from under it. 3024 * 3025 * XXX If another thread attempts to single-thread before us 3026 * (e.g. via fork()), we won't get a dump at all. 3027 */ 3028 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 3029 p->p_sig = sig; 3030 /* 3031 * Log signals which would cause core dumps 3032 * (Log as LOG_INFO to appease those who don't want 3033 * these messages.) 3034 * XXX : Todo, as well as euid, write out ruid too 3035 * Note that coredump() drops proc lock. 3036 */ 3037 if (coredump(td) == 0) 3038 sig |= WCOREFLAG; 3039 if (kern_logsigexit) 3040 log(LOG_INFO, 3041 "pid %d (%s), uid %d: exited on signal %d%s\n", 3042 p->p_pid, p->p_comm, 3043 td->td_ucred ? td->td_ucred->cr_uid : -1, 3044 sig &~ WCOREFLAG, 3045 sig & WCOREFLAG ? " (core dumped)" : ""); 3046 } else 3047 PROC_UNLOCK(p); 3048 exit1(td, W_EXITCODE(0, sig)); 3049 /* NOTREACHED */ 3050} 3051 3052/* 3053 * Send queued SIGCHLD to parent when child process's state 3054 * is changed. 3055 */ 3056static void 3057sigparent(struct proc *p, int reason, int status) 3058{ 3059 PROC_LOCK_ASSERT(p, MA_OWNED); 3060 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3061 3062 if (p->p_ksi != NULL) { 3063 p->p_ksi->ksi_signo = SIGCHLD; 3064 p->p_ksi->ksi_code = reason; 3065 p->p_ksi->ksi_status = status; 3066 p->p_ksi->ksi_pid = p->p_pid; 3067 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3068 if (KSI_ONQ(p->p_ksi)) 3069 return; 3070 } 3071 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3072} 3073 3074static void 3075childproc_jobstate(struct proc *p, int reason, int sig) 3076{ 3077 struct sigacts *ps; 3078 3079 PROC_LOCK_ASSERT(p, MA_OWNED); 3080 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3081 3082 /* 3083 * Wake up parent sleeping in kern_wait(), also send 3084 * SIGCHLD to parent, but SIGCHLD does not guarantee 3085 * that parent will awake, because parent may masked 3086 * the signal. 3087 */ 3088 p->p_pptr->p_flag |= P_STATCHILD; 3089 wakeup(p->p_pptr); 3090 3091 ps = p->p_pptr->p_sigacts; 3092 mtx_lock(&ps->ps_mtx); 3093 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3094 mtx_unlock(&ps->ps_mtx); 3095 sigparent(p, reason, sig); 3096 } else 3097 mtx_unlock(&ps->ps_mtx); 3098} 3099 3100void 3101childproc_stopped(struct proc *p, int reason) 3102{ 3103 /* p_xstat is a plain signal number, not a full wait() status here. */ 3104 childproc_jobstate(p, reason, p->p_xstat); 3105} 3106 3107void 3108childproc_continued(struct proc *p) 3109{ 3110 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3111} 3112 3113void 3114childproc_exited(struct proc *p) 3115{ 3116 int reason; 3117 int xstat = p->p_xstat; /* convert to int */ 3118 int status; 3119 3120 if (WCOREDUMP(xstat)) 3121 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3122 else if (WIFSIGNALED(xstat)) 3123 reason = CLD_KILLED, status = WTERMSIG(xstat); 3124 else 3125 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3126 /* 3127 * XXX avoid calling wakeup(p->p_pptr), the work is 3128 * done in exit1(). 3129 */ 3130 sigparent(p, reason, status); 3131} 3132 3133/* 3134 * We only have 1 character for the core count in the format 3135 * string, so the range will be 0-9 3136 */ 3137#define MAX_NUM_CORES 10 3138static int num_cores = 5; 3139 3140static int 3141sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3142{ 3143 int error; 3144 int new_val; 3145 3146 new_val = num_cores; 3147 error = sysctl_handle_int(oidp, &new_val, 0, req); 3148 if (error != 0 || req->newptr == NULL) 3149 return (error); 3150 if (new_val > MAX_NUM_CORES) 3151 new_val = MAX_NUM_CORES; 3152 if (new_val < 0) 3153 new_val = 0; 3154 num_cores = new_val; 3155 return (0); 3156} 3157SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3158 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3159 3160#if defined(COMPRESS_USER_CORES) 3161int compress_user_cores = 1; 3162SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3163 &compress_user_cores, 0, "Compression of user corefiles"); 3164 3165int compress_user_cores_gzlevel = -1; /* default level */ 3166SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3167 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3168 3169#define GZ_SUFFIX ".gz" 3170#define GZ_SUFFIX_LEN 3 3171#endif 3172 3173static char corefilename[MAXPATHLEN] = {"%N.core"}; 3174TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3175SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3176 sizeof(corefilename), "Process corefile name format string"); 3177 3178/* 3179 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3180 * Expand the name described in corefilename, using name, uid, and pid 3181 * and open/create core file. 3182 * corefilename is a printf-like string, with three format specifiers: 3183 * %N name of process ("name") 3184 * %P process id (pid) 3185 * %U user id (uid) 3186 * For example, "%N.core" is the default; they can be disabled completely 3187 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3188 * This is controlled by the sysctl variable kern.corefile (see above). 3189 */ 3190static int 3191corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3192 int compress, struct vnode **vpp, char **namep) 3193{ 3194 struct nameidata nd; 3195 struct sbuf sb; 3196 const char *format; 3197 char *hostname, *name; 3198 int indexpos, i, error, cmode, flags, oflags; 3199 3200 hostname = NULL; 3201 format = corefilename; 3202 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3203 indexpos = -1; 3204 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3205 for (i = 0; format[i] != '\0'; i++) { 3206 switch (format[i]) { 3207 case '%': /* Format character */ 3208 i++; 3209 switch (format[i]) { 3210 case '%': 3211 sbuf_putc(&sb, '%'); 3212 break; 3213 case 'H': /* hostname */ 3214 if (hostname == NULL) { 3215 hostname = malloc(MAXHOSTNAMELEN, 3216 M_TEMP, M_WAITOK); 3217 } 3218 getcredhostname(td->td_ucred, hostname, 3219 MAXHOSTNAMELEN); 3220 sbuf_printf(&sb, "%s", hostname); 3221 break; 3222 case 'I': /* autoincrementing index */ 3223 sbuf_printf(&sb, "0"); 3224 indexpos = sbuf_len(&sb) - 1; 3225 break; 3226 case 'N': /* process name */ 3227 sbuf_printf(&sb, "%s", comm); 3228 break; 3229 case 'P': /* process id */ 3230 sbuf_printf(&sb, "%u", pid); 3231 break; 3232 case 'U': /* user id */ 3233 sbuf_printf(&sb, "%u", uid); 3234 break; 3235 default: 3236 log(LOG_ERR, 3237 "Unknown format character %c in " 3238 "corename `%s'\n", format[i], format); 3239 break; 3240 } 3241 break; 3242 default: 3243 sbuf_putc(&sb, format[i]); 3244 break; 3245 } 3246 } 3247 free(hostname, M_TEMP); 3248#ifdef COMPRESS_USER_CORES 3249 if (compress) 3250 sbuf_printf(&sb, GZ_SUFFIX); 3251#endif 3252 if (sbuf_error(&sb) != 0) { 3253 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3254 "long\n", (long)pid, comm, (u_long)uid); 3255 sbuf_delete(&sb); 3256 free(name, M_TEMP); 3257 return (ENOMEM); 3258 } 3259 sbuf_finish(&sb); 3260 sbuf_delete(&sb); 3261 3262 cmode = S_IRUSR | S_IWUSR; 3263 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3264 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3265 3266 /* 3267 * If the core format has a %I in it, then we need to check 3268 * for existing corefiles before returning a name. 3269 * To do this we iterate over 0..num_cores to find a 3270 * non-existing core file name to use. 3271 */ 3272 if (indexpos != -1) { 3273 for (i = 0; i < num_cores; i++) { 3274 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3275 name[indexpos] = '0' + i; 3276 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3277 error = vn_open_cred(&nd, &flags, cmode, oflags, 3278 td->td_ucred, NULL); 3279 if (error) { 3280 if (error == EEXIST) 3281 continue; 3282 log(LOG_ERR, 3283 "pid %d (%s), uid (%u): Path `%s' failed " 3284 "on initial open test, error = %d\n", 3285 pid, comm, uid, name, error); 3286 } 3287 goto out; 3288 } 3289 } 3290 3291 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3292 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3293 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3294out: 3295 if (error) { 3296#ifdef AUDIT 3297 audit_proc_coredump(td, name, error); 3298#endif 3299 free(name, M_TEMP); 3300 return (error); 3301 } 3302 NDFREE(&nd, NDF_ONLY_PNBUF); 3303 *vpp = nd.ni_vp; 3304 *namep = name; 3305 return (0); 3306} 3307 3308/* 3309 * Dump a process' core. The main routine does some 3310 * policy checking, and creates the name of the coredump; 3311 * then it passes on a vnode and a size limit to the process-specific 3312 * coredump routine if there is one; if there _is not_ one, it returns 3313 * ENOSYS; otherwise it returns the error from the process-specific routine. 3314 */ 3315 3316static int 3317coredump(struct thread *td) 3318{ 3319 struct proc *p = td->td_proc; 3320 struct ucred *cred = td->td_ucred; 3321 struct vnode *vp; 3322 struct flock lf; 3323 struct vattr vattr; 3324 int error, error1, locked; 3325 struct mount *mp; 3326 char *name; /* name of corefile */ 3327 off_t limit; 3328 int compress; 3329 3330#ifdef COMPRESS_USER_CORES 3331 compress = compress_user_cores; 3332#else 3333 compress = 0; 3334#endif 3335 PROC_LOCK_ASSERT(p, MA_OWNED); 3336 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3337 _STOPEVENT(p, S_CORE, 0); 3338 3339 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3340 (p->p_flag2 & P2_NOTRACE) != 0) { 3341 PROC_UNLOCK(p); 3342 return (EFAULT); 3343 } 3344 3345 /* 3346 * Note that the bulk of limit checking is done after 3347 * the corefile is created. The exception is if the limit 3348 * for corefiles is 0, in which case we don't bother 3349 * creating the corefile at all. This layout means that 3350 * a corefile is truncated instead of not being created, 3351 * if it is larger than the limit. 3352 */ 3353 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3354 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3355 PROC_UNLOCK(p); 3356 return (EFBIG); 3357 } 3358 PROC_UNLOCK(p); 3359 3360restart: 3361 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3362 &vp, &name); 3363 if (error != 0) 3364 return (error); 3365 3366 /* Don't dump to non-regular files or files with links. */ 3367 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3368 vattr.va_nlink != 1) { 3369 VOP_UNLOCK(vp, 0); 3370 error = EFAULT; 3371 goto close; 3372 } 3373 3374 VOP_UNLOCK(vp, 0); 3375 lf.l_whence = SEEK_SET; 3376 lf.l_start = 0; 3377 lf.l_len = 0; 3378 lf.l_type = F_WRLCK; 3379 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3380 3381 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3382 lf.l_type = F_UNLCK; 3383 if (locked) 3384 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3385 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3386 goto out; 3387 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3388 goto out; 3389 free(name, M_TEMP); 3390 goto restart; 3391 } 3392 3393 VATTR_NULL(&vattr); 3394 vattr.va_size = 0; 3395 if (set_core_nodump_flag) 3396 vattr.va_flags = UF_NODUMP; 3397 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3398 VOP_SETATTR(vp, &vattr, cred); 3399 VOP_UNLOCK(vp, 0); 3400 vn_finished_write(mp); 3401 PROC_LOCK(p); 3402 p->p_acflag |= ACORE; 3403 PROC_UNLOCK(p); 3404 3405 if (p->p_sysent->sv_coredump != NULL) { 3406 error = p->p_sysent->sv_coredump(td, vp, limit, 3407 compress ? IMGACT_CORE_COMPRESS : 0); 3408 } else { 3409 error = ENOSYS; 3410 } 3411 3412 if (locked) { 3413 lf.l_type = F_UNLCK; 3414 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3415 } 3416close: 3417 error1 = vn_close(vp, FWRITE, cred, td); 3418 if (error == 0) 3419 error = error1; 3420out: 3421#ifdef AUDIT 3422 audit_proc_coredump(td, name, error); 3423#endif 3424 free(name, M_TEMP); 3425 return (error); 3426} 3427 3428/* 3429 * Nonexistent system call-- signal process (may want to handle it). Flag 3430 * error in case process won't see signal immediately (blocked or ignored). 3431 */ 3432#ifndef _SYS_SYSPROTO_H_ 3433struct nosys_args { 3434 int dummy; 3435}; 3436#endif 3437/* ARGSUSED */ 3438int 3439nosys(td, args) 3440 struct thread *td; 3441 struct nosys_args *args; 3442{ 3443 struct proc *p = td->td_proc; 3444 3445 PROC_LOCK(p); 3446 tdsignal(td, SIGSYS); 3447 PROC_UNLOCK(p); 3448 return (ENOSYS); 3449} 3450 3451/* 3452 * Send a SIGIO or SIGURG signal to a process or process group using stored 3453 * credentials rather than those of the current process. 3454 */ 3455void 3456pgsigio(sigiop, sig, checkctty) 3457 struct sigio **sigiop; 3458 int sig, checkctty; 3459{ 3460 ksiginfo_t ksi; 3461 struct sigio *sigio; 3462 3463 ksiginfo_init(&ksi); 3464 ksi.ksi_signo = sig; 3465 ksi.ksi_code = SI_KERNEL; 3466 3467 SIGIO_LOCK(); 3468 sigio = *sigiop; 3469 if (sigio == NULL) { 3470 SIGIO_UNLOCK(); 3471 return; 3472 } 3473 if (sigio->sio_pgid > 0) { 3474 PROC_LOCK(sigio->sio_proc); 3475 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3476 kern_psignal(sigio->sio_proc, sig); 3477 PROC_UNLOCK(sigio->sio_proc); 3478 } else if (sigio->sio_pgid < 0) { 3479 struct proc *p; 3480 3481 PGRP_LOCK(sigio->sio_pgrp); 3482 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3483 PROC_LOCK(p); 3484 if (p->p_state == PRS_NORMAL && 3485 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3486 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3487 kern_psignal(p, sig); 3488 PROC_UNLOCK(p); 3489 } 3490 PGRP_UNLOCK(sigio->sio_pgrp); 3491 } 3492 SIGIO_UNLOCK(); 3493} 3494 3495static int 3496filt_sigattach(struct knote *kn) 3497{ 3498 struct proc *p = curproc; 3499 3500 kn->kn_ptr.p_proc = p; 3501 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3502 3503 knlist_add(&p->p_klist, kn, 0); 3504 3505 return (0); 3506} 3507 3508static void 3509filt_sigdetach(struct knote *kn) 3510{ 3511 struct proc *p = kn->kn_ptr.p_proc; 3512 3513 knlist_remove(&p->p_klist, kn, 0); 3514} 3515 3516/* 3517 * signal knotes are shared with proc knotes, so we apply a mask to 3518 * the hint in order to differentiate them from process hints. This 3519 * could be avoided by using a signal-specific knote list, but probably 3520 * isn't worth the trouble. 3521 */ 3522static int 3523filt_signal(struct knote *kn, long hint) 3524{ 3525 3526 if (hint & NOTE_SIGNAL) { 3527 hint &= ~NOTE_SIGNAL; 3528 3529 if (kn->kn_id == hint) 3530 kn->kn_data++; 3531 } 3532 return (kn->kn_data != 0); 3533} 3534 3535struct sigacts * 3536sigacts_alloc(void) 3537{ 3538 struct sigacts *ps; 3539 3540 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3541 ps->ps_refcnt = 1; 3542 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3543 return (ps); 3544} 3545 3546void 3547sigacts_free(struct sigacts *ps) 3548{ 3549 3550 if (refcount_release(&ps->ps_refcnt) == 0) 3551 return; 3552 mtx_destroy(&ps->ps_mtx); 3553 free(ps, M_SUBPROC); 3554} 3555 3556struct sigacts * 3557sigacts_hold(struct sigacts *ps) 3558{ 3559 3560 refcount_acquire(&ps->ps_refcnt); 3561 return (ps); 3562} 3563 3564void 3565sigacts_copy(struct sigacts *dest, struct sigacts *src) 3566{ 3567 3568 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3569 mtx_lock(&src->ps_mtx); 3570 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3571 mtx_unlock(&src->ps_mtx); 3572} 3573 3574int 3575sigacts_shared(struct sigacts *ps) 3576{ 3577 3578 return (ps->ps_refcnt > 1); 3579} 3580