kern_sig.c revision 318323
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 318323 2017-05-15 22:50:54Z brooks $"); 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 union sigval sv; 1850 1851 sv.sival_ptr = uap->value; 1852 1853 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1854} 1855 1856int 1857kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1858{ 1859 ksiginfo_t ksi; 1860 struct proc *p; 1861 int error; 1862 1863 if ((u_int)signum > _SIG_MAXSIG) 1864 return (EINVAL); 1865 1866 /* 1867 * Specification says sigqueue can only send signal to 1868 * single process. 1869 */ 1870 if (pid <= 0) 1871 return (EINVAL); 1872 1873 if ((p = pfind(pid)) == NULL) { 1874 if ((p = zpfind(pid)) == NULL) 1875 return (ESRCH); 1876 } 1877 error = p_cansignal(td, p, signum); 1878 if (error == 0 && signum != 0) { 1879 ksiginfo_init(&ksi); 1880 ksi.ksi_flags = KSI_SIGQ; 1881 ksi.ksi_signo = signum; 1882 ksi.ksi_code = SI_QUEUE; 1883 ksi.ksi_pid = td->td_proc->p_pid; 1884 ksi.ksi_uid = td->td_ucred->cr_ruid; 1885 ksi.ksi_value = *value; 1886 error = pksignal(p, ksi.ksi_signo, &ksi); 1887 } 1888 PROC_UNLOCK(p); 1889 return (error); 1890} 1891 1892/* 1893 * Send a signal to a process group. 1894 */ 1895void 1896gsignal(int pgid, int sig, ksiginfo_t *ksi) 1897{ 1898 struct pgrp *pgrp; 1899 1900 if (pgid != 0) { 1901 sx_slock(&proctree_lock); 1902 pgrp = pgfind(pgid); 1903 sx_sunlock(&proctree_lock); 1904 if (pgrp != NULL) { 1905 pgsignal(pgrp, sig, 0, ksi); 1906 PGRP_UNLOCK(pgrp); 1907 } 1908 } 1909} 1910 1911/* 1912 * Send a signal to a process group. If checktty is 1, 1913 * limit to members which have a controlling terminal. 1914 */ 1915void 1916pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1917{ 1918 struct proc *p; 1919 1920 if (pgrp) { 1921 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1922 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1923 PROC_LOCK(p); 1924 if (p->p_state == PRS_NORMAL && 1925 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1926 pksignal(p, sig, ksi); 1927 PROC_UNLOCK(p); 1928 } 1929 } 1930} 1931 1932 1933/* 1934 * Recalculate the signal mask and reset the signal disposition after 1935 * usermode frame for delivery is formed. Should be called after 1936 * mach-specific routine, because sysent->sv_sendsig() needs correct 1937 * ps_siginfo and signal mask. 1938 */ 1939static void 1940postsig_done(int sig, struct thread *td, struct sigacts *ps) 1941{ 1942 sigset_t mask; 1943 1944 mtx_assert(&ps->ps_mtx, MA_OWNED); 1945 td->td_ru.ru_nsignals++; 1946 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1947 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1948 SIGADDSET(mask, sig); 1949 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1950 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1951 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1952 sigdflt(ps, sig); 1953} 1954 1955 1956/* 1957 * Send a signal caused by a trap to the current thread. If it will be 1958 * caught immediately, deliver it with correct code. Otherwise, post it 1959 * normally. 1960 */ 1961void 1962trapsignal(struct thread *td, ksiginfo_t *ksi) 1963{ 1964 struct sigacts *ps; 1965 struct proc *p; 1966 int sig; 1967 int code; 1968 1969 p = td->td_proc; 1970 sig = ksi->ksi_signo; 1971 code = ksi->ksi_code; 1972 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1973 1974 PROC_LOCK(p); 1975 ps = p->p_sigacts; 1976 mtx_lock(&ps->ps_mtx); 1977 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1978 !SIGISMEMBER(td->td_sigmask, sig)) { 1979#ifdef KTRACE 1980 if (KTRPOINT(curthread, KTR_PSIG)) 1981 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1982 &td->td_sigmask, code); 1983#endif 1984 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1985 ksi, &td->td_sigmask); 1986 postsig_done(sig, td, ps); 1987 mtx_unlock(&ps->ps_mtx); 1988 } else { 1989 /* 1990 * Avoid a possible infinite loop if the thread 1991 * masking the signal or process is ignoring the 1992 * signal. 1993 */ 1994 if (kern_forcesigexit && 1995 (SIGISMEMBER(td->td_sigmask, sig) || 1996 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 1997 SIGDELSET(td->td_sigmask, sig); 1998 SIGDELSET(ps->ps_sigcatch, sig); 1999 SIGDELSET(ps->ps_sigignore, sig); 2000 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2001 } 2002 mtx_unlock(&ps->ps_mtx); 2003 p->p_code = code; /* XXX for core dump/debugger */ 2004 p->p_sig = sig; /* XXX to verify code */ 2005 tdsendsignal(p, td, sig, ksi); 2006 } 2007 PROC_UNLOCK(p); 2008} 2009 2010static struct thread * 2011sigtd(struct proc *p, int sig, int prop) 2012{ 2013 struct thread *td, *signal_td; 2014 2015 PROC_LOCK_ASSERT(p, MA_OWNED); 2016 2017 /* 2018 * Check if current thread can handle the signal without 2019 * switching context to another thread. 2020 */ 2021 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2022 return (curthread); 2023 signal_td = NULL; 2024 FOREACH_THREAD_IN_PROC(p, td) { 2025 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2026 signal_td = td; 2027 break; 2028 } 2029 } 2030 if (signal_td == NULL) 2031 signal_td = FIRST_THREAD_IN_PROC(p); 2032 return (signal_td); 2033} 2034 2035/* 2036 * Send the signal to the process. If the signal has an action, the action 2037 * is usually performed by the target process rather than the caller; we add 2038 * the signal to the set of pending signals for the process. 2039 * 2040 * Exceptions: 2041 * o When a stop signal is sent to a sleeping process that takes the 2042 * default action, the process is stopped without awakening it. 2043 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2044 * regardless of the signal action (eg, blocked or ignored). 2045 * 2046 * Other ignored signals are discarded immediately. 2047 * 2048 * NB: This function may be entered from the debugger via the "kill" DDB 2049 * command. There is little that can be done to mitigate the possibly messy 2050 * side effects of this unwise possibility. 2051 */ 2052void 2053kern_psignal(struct proc *p, int sig) 2054{ 2055 ksiginfo_t ksi; 2056 2057 ksiginfo_init(&ksi); 2058 ksi.ksi_signo = sig; 2059 ksi.ksi_code = SI_KERNEL; 2060 (void) tdsendsignal(p, NULL, sig, &ksi); 2061} 2062 2063int 2064pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2065{ 2066 2067 return (tdsendsignal(p, NULL, sig, ksi)); 2068} 2069 2070/* Utility function for finding a thread to send signal event to. */ 2071int 2072sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2073{ 2074 struct thread *td; 2075 2076 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2077 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2078 if (td == NULL) 2079 return (ESRCH); 2080 *ttd = td; 2081 } else { 2082 *ttd = NULL; 2083 PROC_LOCK(p); 2084 } 2085 return (0); 2086} 2087 2088void 2089tdsignal(struct thread *td, int sig) 2090{ 2091 ksiginfo_t ksi; 2092 2093 ksiginfo_init(&ksi); 2094 ksi.ksi_signo = sig; 2095 ksi.ksi_code = SI_KERNEL; 2096 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2097} 2098 2099void 2100tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2101{ 2102 2103 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2104} 2105 2106int 2107tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2108{ 2109 sig_t action; 2110 sigqueue_t *sigqueue; 2111 int prop; 2112 struct sigacts *ps; 2113 int intrval; 2114 int ret = 0; 2115 int wakeup_swapper; 2116 2117 MPASS(td == NULL || p == td->td_proc); 2118 PROC_LOCK_ASSERT(p, MA_OWNED); 2119 2120 if (!_SIG_VALID(sig)) 2121 panic("%s(): invalid signal %d", __func__, sig); 2122 2123 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2124 2125 /* 2126 * IEEE Std 1003.1-2001: return success when killing a zombie. 2127 */ 2128 if (p->p_state == PRS_ZOMBIE) { 2129 if (ksi && (ksi->ksi_flags & KSI_INS)) 2130 ksiginfo_tryfree(ksi); 2131 return (ret); 2132 } 2133 2134 ps = p->p_sigacts; 2135 KNOTE_LOCKED(&p->p_klist, NOTE_SIGNAL | sig); 2136 prop = sigprop(sig); 2137 2138 if (td == NULL) { 2139 td = sigtd(p, sig, prop); 2140 sigqueue = &p->p_sigqueue; 2141 } else 2142 sigqueue = &td->td_sigqueue; 2143 2144 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2145 2146 /* 2147 * If the signal is being ignored, 2148 * then we forget about it immediately. 2149 * (Note: we don't set SIGCONT in ps_sigignore, 2150 * and if it is set to SIG_IGN, 2151 * action will be SIG_DFL here.) 2152 */ 2153 mtx_lock(&ps->ps_mtx); 2154 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2155 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2156 2157 mtx_unlock(&ps->ps_mtx); 2158 if (ksi && (ksi->ksi_flags & KSI_INS)) 2159 ksiginfo_tryfree(ksi); 2160 return (ret); 2161 } 2162 if (SIGISMEMBER(td->td_sigmask, sig)) 2163 action = SIG_HOLD; 2164 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2165 action = SIG_CATCH; 2166 else 2167 action = SIG_DFL; 2168 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2169 intrval = EINTR; 2170 else 2171 intrval = ERESTART; 2172 mtx_unlock(&ps->ps_mtx); 2173 2174 if (prop & SA_CONT) 2175 sigqueue_delete_stopmask_proc(p); 2176 else if (prop & SA_STOP) { 2177 /* 2178 * If sending a tty stop signal to a member of an orphaned 2179 * process group, discard the signal here if the action 2180 * is default; don't stop the process below if sleeping, 2181 * and don't clear any pending SIGCONT. 2182 */ 2183 if ((prop & SA_TTYSTOP) && 2184 (p->p_pgrp->pg_jobc == 0) && 2185 (action == SIG_DFL)) { 2186 if (ksi && (ksi->ksi_flags & KSI_INS)) 2187 ksiginfo_tryfree(ksi); 2188 return (ret); 2189 } 2190 sigqueue_delete_proc(p, SIGCONT); 2191 if (p->p_flag & P_CONTINUED) { 2192 p->p_flag &= ~P_CONTINUED; 2193 PROC_LOCK(p->p_pptr); 2194 sigqueue_take(p->p_ksi); 2195 PROC_UNLOCK(p->p_pptr); 2196 } 2197 } 2198 2199 ret = sigqueue_add(sigqueue, sig, ksi); 2200 if (ret != 0) 2201 return (ret); 2202 signotify(td); 2203 /* 2204 * Defer further processing for signals which are held, 2205 * except that stopped processes must be continued by SIGCONT. 2206 */ 2207 if (action == SIG_HOLD && 2208 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2209 return (ret); 2210 2211 /* SIGKILL: Remove procfs STOPEVENTs. */ 2212 if (sig == SIGKILL) { 2213 /* from procfs_ioctl.c: PIOCBIC */ 2214 p->p_stops = 0; 2215 /* from procfs_ioctl.c: PIOCCONT */ 2216 p->p_step = 0; 2217 wakeup(&p->p_step); 2218 } 2219 /* 2220 * Some signals have a process-wide effect and a per-thread 2221 * component. Most processing occurs when the process next 2222 * tries to cross the user boundary, however there are some 2223 * times when processing needs to be done immediately, such as 2224 * waking up threads so that they can cross the user boundary. 2225 * We try to do the per-process part here. 2226 */ 2227 if (P_SHOULDSTOP(p)) { 2228 KASSERT(!(p->p_flag & P_WEXIT), 2229 ("signal to stopped but exiting process")); 2230 if (sig == SIGKILL) { 2231 /* 2232 * If traced process is already stopped, 2233 * then no further action is necessary. 2234 */ 2235 if (p->p_flag & P_TRACED) 2236 goto out; 2237 /* 2238 * SIGKILL sets process running. 2239 * It will die elsewhere. 2240 * All threads must be restarted. 2241 */ 2242 p->p_flag &= ~P_STOPPED_SIG; 2243 goto runfast; 2244 } 2245 2246 if (prop & SA_CONT) { 2247 /* 2248 * If traced process is already stopped, 2249 * then no further action is necessary. 2250 */ 2251 if (p->p_flag & P_TRACED) 2252 goto out; 2253 /* 2254 * If SIGCONT is default (or ignored), we continue the 2255 * process but don't leave the signal in sigqueue as 2256 * it has no further action. If SIGCONT is held, we 2257 * continue the process and leave the signal in 2258 * sigqueue. If the process catches SIGCONT, let it 2259 * handle the signal itself. If it isn't waiting on 2260 * an event, it goes back to run state. 2261 * Otherwise, process goes back to sleep state. 2262 */ 2263 p->p_flag &= ~P_STOPPED_SIG; 2264 PROC_SLOCK(p); 2265 if (p->p_numthreads == p->p_suspcount) { 2266 PROC_SUNLOCK(p); 2267 p->p_flag |= P_CONTINUED; 2268 p->p_xstat = SIGCONT; 2269 PROC_LOCK(p->p_pptr); 2270 childproc_continued(p); 2271 PROC_UNLOCK(p->p_pptr); 2272 PROC_SLOCK(p); 2273 } 2274 if (action == SIG_DFL) { 2275 thread_unsuspend(p); 2276 PROC_SUNLOCK(p); 2277 sigqueue_delete(sigqueue, sig); 2278 goto out; 2279 } 2280 if (action == SIG_CATCH) { 2281 /* 2282 * The process wants to catch it so it needs 2283 * to run at least one thread, but which one? 2284 */ 2285 PROC_SUNLOCK(p); 2286 goto runfast; 2287 } 2288 /* 2289 * The signal is not ignored or caught. 2290 */ 2291 thread_unsuspend(p); 2292 PROC_SUNLOCK(p); 2293 goto out; 2294 } 2295 2296 if (prop & SA_STOP) { 2297 /* 2298 * If traced process is already stopped, 2299 * then no further action is necessary. 2300 */ 2301 if (p->p_flag & P_TRACED) 2302 goto out; 2303 /* 2304 * Already stopped, don't need to stop again 2305 * (If we did the shell could get confused). 2306 * Just make sure the signal STOP bit set. 2307 */ 2308 p->p_flag |= P_STOPPED_SIG; 2309 sigqueue_delete(sigqueue, sig); 2310 goto out; 2311 } 2312 2313 /* 2314 * All other kinds of signals: 2315 * If a thread is sleeping interruptibly, simulate a 2316 * wakeup so that when it is continued it will be made 2317 * runnable and can look at the signal. However, don't make 2318 * the PROCESS runnable, leave it stopped. 2319 * It may run a bit until it hits a thread_suspend_check(). 2320 */ 2321 wakeup_swapper = 0; 2322 PROC_SLOCK(p); 2323 thread_lock(td); 2324 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2325 wakeup_swapper = sleepq_abort(td, intrval); 2326 thread_unlock(td); 2327 PROC_SUNLOCK(p); 2328 if (wakeup_swapper) 2329 kick_proc0(); 2330 goto out; 2331 /* 2332 * Mutexes are short lived. Threads waiting on them will 2333 * hit thread_suspend_check() soon. 2334 */ 2335 } else if (p->p_state == PRS_NORMAL) { 2336 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2337 tdsigwakeup(td, sig, action, intrval); 2338 goto out; 2339 } 2340 2341 MPASS(action == SIG_DFL); 2342 2343 if (prop & SA_STOP) { 2344 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2345 goto out; 2346 p->p_flag |= P_STOPPED_SIG; 2347 p->p_xstat = sig; 2348 PROC_SLOCK(p); 2349 sig_suspend_threads(td, p, 1); 2350 if (p->p_numthreads == p->p_suspcount) { 2351 /* 2352 * only thread sending signal to another 2353 * process can reach here, if thread is sending 2354 * signal to its process, because thread does 2355 * not suspend itself here, p_numthreads 2356 * should never be equal to p_suspcount. 2357 */ 2358 thread_stopped(p); 2359 PROC_SUNLOCK(p); 2360 sigqueue_delete_proc(p, p->p_xstat); 2361 } else 2362 PROC_SUNLOCK(p); 2363 goto out; 2364 } 2365 } else { 2366 /* Not in "NORMAL" state. discard the signal. */ 2367 sigqueue_delete(sigqueue, sig); 2368 goto out; 2369 } 2370 2371 /* 2372 * The process is not stopped so we need to apply the signal to all the 2373 * running threads. 2374 */ 2375runfast: 2376 tdsigwakeup(td, sig, action, intrval); 2377 PROC_SLOCK(p); 2378 thread_unsuspend(p); 2379 PROC_SUNLOCK(p); 2380out: 2381 /* If we jump here, proc slock should not be owned. */ 2382 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2383 return (ret); 2384} 2385 2386/* 2387 * The force of a signal has been directed against a single 2388 * thread. We need to see what we can do about knocking it 2389 * out of any sleep it may be in etc. 2390 */ 2391static void 2392tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2393{ 2394 struct proc *p = td->td_proc; 2395 register int prop; 2396 int wakeup_swapper; 2397 2398 wakeup_swapper = 0; 2399 PROC_LOCK_ASSERT(p, MA_OWNED); 2400 prop = sigprop(sig); 2401 2402 PROC_SLOCK(p); 2403 thread_lock(td); 2404 /* 2405 * Bring the priority of a thread up if we want it to get 2406 * killed in this lifetime. Be careful to avoid bumping the 2407 * priority of the idle thread, since we still allow to signal 2408 * kernel processes. 2409 */ 2410 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2411 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2412 sched_prio(td, PUSER); 2413 if (TD_ON_SLEEPQ(td)) { 2414 /* 2415 * If thread is sleeping uninterruptibly 2416 * we can't interrupt the sleep... the signal will 2417 * be noticed when the process returns through 2418 * trap() or syscall(). 2419 */ 2420 if ((td->td_flags & TDF_SINTR) == 0) 2421 goto out; 2422 /* 2423 * If SIGCONT is default (or ignored) and process is 2424 * asleep, we are finished; the process should not 2425 * be awakened. 2426 */ 2427 if ((prop & SA_CONT) && action == SIG_DFL) { 2428 thread_unlock(td); 2429 PROC_SUNLOCK(p); 2430 sigqueue_delete(&p->p_sigqueue, sig); 2431 /* 2432 * It may be on either list in this state. 2433 * Remove from both for now. 2434 */ 2435 sigqueue_delete(&td->td_sigqueue, sig); 2436 return; 2437 } 2438 2439 /* 2440 * Don't awaken a sleeping thread for SIGSTOP if the 2441 * STOP signal is deferred. 2442 */ 2443 if ((prop & SA_STOP) && (td->td_flags & TDF_SBDRY)) 2444 goto out; 2445 2446 /* 2447 * Give low priority threads a better chance to run. 2448 */ 2449 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2450 sched_prio(td, PUSER); 2451 2452 wakeup_swapper = sleepq_abort(td, intrval); 2453 } else { 2454 /* 2455 * Other states do nothing with the signal immediately, 2456 * other than kicking ourselves if we are running. 2457 * It will either never be noticed, or noticed very soon. 2458 */ 2459#ifdef SMP 2460 if (TD_IS_RUNNING(td) && td != curthread) 2461 forward_signal(td); 2462#endif 2463 } 2464out: 2465 PROC_SUNLOCK(p); 2466 thread_unlock(td); 2467 if (wakeup_swapper) 2468 kick_proc0(); 2469} 2470 2471static void 2472sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2473{ 2474 struct thread *td2; 2475 2476 PROC_LOCK_ASSERT(p, MA_OWNED); 2477 PROC_SLOCK_ASSERT(p, MA_OWNED); 2478 2479 FOREACH_THREAD_IN_PROC(p, td2) { 2480 thread_lock(td2); 2481 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2482 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2483 (td2->td_flags & TDF_SINTR)) { 2484 if (td2->td_flags & TDF_SBDRY) { 2485 /* 2486 * Once a thread is asleep with 2487 * TDF_SBDRY set, it should never 2488 * become suspended due to this check. 2489 */ 2490 KASSERT(!TD_IS_SUSPENDED(td2), 2491 ("thread with deferred stops suspended")); 2492 } else if (!TD_IS_SUSPENDED(td2)) { 2493 thread_suspend_one(td2); 2494 } 2495 } else if (!TD_IS_SUSPENDED(td2)) { 2496 if (sending || td != td2) 2497 td2->td_flags |= TDF_ASTPENDING; 2498#ifdef SMP 2499 if (TD_IS_RUNNING(td2) && td2 != td) 2500 forward_signal(td2); 2501#endif 2502 } 2503 thread_unlock(td2); 2504 } 2505} 2506 2507/* 2508 * Stop the process for an event deemed interesting to the debugger. If si is 2509 * non-NULL, this is a signal exchange; the new signal requested by the 2510 * debugger will be returned for handling. If si is NULL, this is some other 2511 * type of interesting event. The debugger may request a signal be delivered in 2512 * that case as well, however it will be deferred until it can be handled. 2513 */ 2514int 2515ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2516{ 2517 struct proc *p = td->td_proc; 2518 struct thread *td2; 2519 ksiginfo_t ksi; 2520 int prop; 2521 2522 PROC_LOCK_ASSERT(p, MA_OWNED); 2523 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2524 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2525 &p->p_mtx.lock_object, "Stopping for traced signal"); 2526 2527 td->td_xsig = sig; 2528 2529 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2530 td->td_dbgflags |= TDB_XSIG; 2531 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2532 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2533 PROC_SLOCK(p); 2534 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2535 if (P_KILLED(p)) { 2536 /* 2537 * Ensure that, if we've been PT_KILLed, the 2538 * exit status reflects that. Another thread 2539 * may also be in ptracestop(), having just 2540 * received the SIGKILL, but this thread was 2541 * unsuspended first. 2542 */ 2543 td->td_dbgflags &= ~TDB_XSIG; 2544 td->td_xsig = SIGKILL; 2545 p->p_ptevents = 0; 2546 break; 2547 } 2548 if (p->p_flag & P_SINGLE_EXIT && 2549 !(td->td_dbgflags & TDB_EXIT)) { 2550 /* 2551 * Ignore ptrace stops except for thread exit 2552 * events when the process exits. 2553 */ 2554 td->td_dbgflags &= ~TDB_XSIG; 2555 PROC_SUNLOCK(p); 2556 return (0); 2557 } 2558 2559 /* 2560 * Make wait(2) work. Ensure that right after the 2561 * attach, the thread which was decided to become the 2562 * leader of attach gets reported to the waiter. 2563 * Otherwise, just avoid overwriting another thread's 2564 * assignment to p_xthread. If another thread has 2565 * already set p_xthread, the current thread will get 2566 * a chance to report itself upon the next iteration. 2567 */ 2568 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2569 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2570 p->p_xthread == NULL)) { 2571 p->p_xstat = sig; 2572 p->p_xthread = td; 2573 td->td_dbgflags &= ~TDB_FSTP; 2574 p->p_flag2 &= ~P2_PTRACE_FSTP; 2575 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2576 sig_suspend_threads(td, p, 0); 2577 } 2578 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2579 td->td_dbgflags &= ~TDB_STOPATFORK; 2580 cv_broadcast(&p->p_dbgwait); 2581 } 2582stopme: 2583 thread_suspend_switch(td, p); 2584 if (p->p_xthread == td) 2585 p->p_xthread = NULL; 2586 if (!(p->p_flag & P_TRACED)) 2587 break; 2588 if (td->td_dbgflags & TDB_SUSPEND) { 2589 if (p->p_flag & P_SINGLE_EXIT) 2590 break; 2591 goto stopme; 2592 } 2593 } 2594 PROC_SUNLOCK(p); 2595 } 2596 2597 if (si != NULL && sig == td->td_xsig) { 2598 /* Parent wants us to take the original signal unchanged. */ 2599 si->ksi_flags |= KSI_HEAD; 2600 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2601 si->ksi_signo = 0; 2602 } else if (td->td_xsig != 0) { 2603 /* 2604 * If parent wants us to take a new signal, then it will leave 2605 * it in td->td_xsig; otherwise we just look for signals again. 2606 */ 2607 ksiginfo_init(&ksi); 2608 ksi.ksi_signo = td->td_xsig; 2609 ksi.ksi_flags |= KSI_PTRACE; 2610 prop = sigprop(td->td_xsig); 2611 td2 = sigtd(p, td->td_xsig, prop); 2612 tdsendsignal(p, td2, td->td_xsig, &ksi); 2613 if (td != td2) 2614 return (0); 2615 } 2616 2617 return (td->td_xsig); 2618} 2619 2620static void 2621reschedule_signals(struct proc *p, sigset_t block, int flags) 2622{ 2623 struct sigacts *ps; 2624 struct thread *td; 2625 int sig; 2626 2627 PROC_LOCK_ASSERT(p, MA_OWNED); 2628 ps = p->p_sigacts; 2629 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2630 MA_OWNED : MA_NOTOWNED); 2631 if (SIGISEMPTY(p->p_siglist)) 2632 return; 2633 SIGSETAND(block, p->p_siglist); 2634 while ((sig = sig_ffs(&block)) != 0) { 2635 SIGDELSET(block, sig); 2636 td = sigtd(p, sig, 0); 2637 signotify(td); 2638 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2639 mtx_lock(&ps->ps_mtx); 2640 if (p->p_flag & P_TRACED || SIGISMEMBER(ps->ps_sigcatch, sig)) 2641 tdsigwakeup(td, sig, SIG_CATCH, 2642 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2643 ERESTART)); 2644 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2645 mtx_unlock(&ps->ps_mtx); 2646 } 2647} 2648 2649void 2650tdsigcleanup(struct thread *td) 2651{ 2652 struct proc *p; 2653 sigset_t unblocked; 2654 2655 p = td->td_proc; 2656 PROC_LOCK_ASSERT(p, MA_OWNED); 2657 2658 sigqueue_flush(&td->td_sigqueue); 2659 if (p->p_numthreads == 1) 2660 return; 2661 2662 /* 2663 * Since we cannot handle signals, notify signal post code 2664 * about this by filling the sigmask. 2665 * 2666 * Also, if needed, wake up thread(s) that do not block the 2667 * same signals as the exiting thread, since the thread might 2668 * have been selected for delivery and woken up. 2669 */ 2670 SIGFILLSET(unblocked); 2671 SIGSETNAND(unblocked, td->td_sigmask); 2672 SIGFILLSET(td->td_sigmask); 2673 reschedule_signals(p, unblocked, 0); 2674 2675} 2676 2677/* 2678 * Defer the delivery of SIGSTOP for the current thread. Returns true 2679 * if stops were deferred and false if they were already deferred. 2680 */ 2681int 2682sigdeferstop(void) 2683{ 2684 struct thread *td; 2685 2686 td = curthread; 2687 if (td->td_flags & TDF_SBDRY) 2688 return (0); 2689 thread_lock(td); 2690 td->td_flags |= TDF_SBDRY; 2691 thread_unlock(td); 2692 return (1); 2693} 2694 2695/* 2696 * Permit the delivery of SIGSTOP for the current thread. This does 2697 * not immediately suspend if a stop was posted. Instead, the thread 2698 * will suspend either via ast() or a subsequent interruptible sleep. 2699 */ 2700int 2701sigallowstop(void) 2702{ 2703 struct thread *td; 2704 int prev; 2705 2706 td = curthread; 2707 thread_lock(td); 2708 prev = (td->td_flags & TDF_SBDRY) != 0; 2709 td->td_flags &= ~TDF_SBDRY; 2710 thread_unlock(td); 2711 return (prev); 2712} 2713 2714/* 2715 * If the current process has received a signal (should be caught or cause 2716 * termination, should interrupt current syscall), return the signal number. 2717 * Stop signals with default action are processed immediately, then cleared; 2718 * they aren't returned. This is checked after each entry to the system for 2719 * a syscall or trap (though this can usually be done without calling issignal 2720 * by checking the pending signal masks in cursig.) The normal call 2721 * sequence is 2722 * 2723 * while (sig = cursig(curthread)) 2724 * postsig(sig); 2725 */ 2726static int 2727issignal(struct thread *td) 2728{ 2729 struct proc *p; 2730 struct sigacts *ps; 2731 struct sigqueue *queue; 2732 sigset_t sigpending; 2733 int sig, prop; 2734 2735 p = td->td_proc; 2736 ps = p->p_sigacts; 2737 mtx_assert(&ps->ps_mtx, MA_OWNED); 2738 PROC_LOCK_ASSERT(p, MA_OWNED); 2739 for (;;) { 2740 int traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2741 2742 sigpending = td->td_sigqueue.sq_signals; 2743 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2744 SIGSETNAND(sigpending, td->td_sigmask); 2745 2746 if (p->p_flag & P_PPWAIT || td->td_flags & TDF_SBDRY) 2747 SIG_STOPSIGMASK(sigpending); 2748 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2749 return (0); 2750 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2751 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2752 SIGISMEMBER(sigpending, SIGSTOP)) { 2753 /* 2754 * If debugger just attached, always consume 2755 * SIGSTOP from ptrace(PT_ATTACH) first, to 2756 * execute the debugger attach ritual in 2757 * order. 2758 */ 2759 sig = SIGSTOP; 2760 td->td_dbgflags |= TDB_FSTP; 2761 } else { 2762 sig = sig_ffs(&sigpending); 2763 } 2764 2765 if (p->p_stops & S_SIG) { 2766 mtx_unlock(&ps->ps_mtx); 2767 stopevent(p, S_SIG, sig); 2768 mtx_lock(&ps->ps_mtx); 2769 } 2770 2771 /* 2772 * We should see pending but ignored signals 2773 * only if P_TRACED was on when they were posted. 2774 */ 2775 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2776 sigqueue_delete(&td->td_sigqueue, sig); 2777 sigqueue_delete(&p->p_sigqueue, sig); 2778 continue; 2779 } 2780 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2781 /* 2782 * If traced, always stop. 2783 * Remove old signal from queue before the stop. 2784 * XXX shrug off debugger, it causes siginfo to 2785 * be thrown away. 2786 */ 2787 queue = &td->td_sigqueue; 2788 td->td_dbgksi.ksi_signo = 0; 2789 if (sigqueue_get(queue, sig, &td->td_dbgksi) == 0) { 2790 queue = &p->p_sigqueue; 2791 sigqueue_get(queue, sig, &td->td_dbgksi); 2792 } 2793 2794 mtx_unlock(&ps->ps_mtx); 2795 sig = ptracestop(td, sig, &td->td_dbgksi); 2796 mtx_lock(&ps->ps_mtx); 2797 2798 /* 2799 * Keep looking if the debugger discarded the signal 2800 * or replaced it with a masked signal. 2801 * 2802 * If the traced bit got turned off, go back up 2803 * to the top to rescan signals. This ensures 2804 * that p_sig* and p_sigact are consistent. 2805 */ 2806 if (sig == 0 || (p->p_flag & P_TRACED) == 0) 2807 continue; 2808 } 2809 2810 prop = sigprop(sig); 2811 2812 /* 2813 * Decide whether the signal should be returned. 2814 * Return the signal's number, or fall through 2815 * to clear it from the pending mask. 2816 */ 2817 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2818 2819 case (intptr_t)SIG_DFL: 2820 /* 2821 * Don't take default actions on system processes. 2822 */ 2823 if (p->p_pid <= 1) { 2824#ifdef DIAGNOSTIC 2825 /* 2826 * Are you sure you want to ignore SIGSEGV 2827 * in init? XXX 2828 */ 2829 printf("Process (pid %lu) got signal %d\n", 2830 (u_long)p->p_pid, sig); 2831#endif 2832 break; /* == ignore */ 2833 } 2834 /* 2835 * If there is a pending stop signal to process with 2836 * default action, stop here, then clear the signal. 2837 * Traced or exiting processes should ignore stops. 2838 * Additionally, a member of an orphaned process group 2839 * should ignore tty stops. 2840 */ 2841 if (prop & SA_STOP) { 2842 if (p->p_flag & 2843 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2844 (p->p_pgrp->pg_jobc == 0 && 2845 prop & SA_TTYSTOP)) 2846 break; /* == ignore */ 2847 mtx_unlock(&ps->ps_mtx); 2848 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2849 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2850 sigqueue_delete(&td->td_sigqueue, sig); 2851 sigqueue_delete(&p->p_sigqueue, sig); 2852 p->p_flag |= P_STOPPED_SIG; 2853 p->p_xstat = sig; 2854 PROC_SLOCK(p); 2855 sig_suspend_threads(td, p, 0); 2856 thread_suspend_switch(td, p); 2857 PROC_SUNLOCK(p); 2858 mtx_lock(&ps->ps_mtx); 2859 goto next; 2860 } else if (prop & SA_IGNORE) { 2861 /* 2862 * Except for SIGCONT, shouldn't get here. 2863 * Default action is to ignore; drop it. 2864 */ 2865 break; /* == ignore */ 2866 } else 2867 return (sig); 2868 /*NOTREACHED*/ 2869 2870 case (intptr_t)SIG_IGN: 2871 /* 2872 * Masking above should prevent us ever trying 2873 * to take action on an ignored signal other 2874 * than SIGCONT, unless process is traced. 2875 */ 2876 if ((prop & SA_CONT) == 0 && 2877 (p->p_flag & P_TRACED) == 0) 2878 printf("issignal\n"); 2879 break; /* == ignore */ 2880 2881 default: 2882 /* 2883 * This signal has an action, let 2884 * postsig() process it. 2885 */ 2886 return (sig); 2887 } 2888 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2889 sigqueue_delete(&p->p_sigqueue, sig); 2890next:; 2891 } 2892 /* NOTREACHED */ 2893} 2894 2895void 2896thread_stopped(struct proc *p) 2897{ 2898 int n; 2899 2900 PROC_LOCK_ASSERT(p, MA_OWNED); 2901 PROC_SLOCK_ASSERT(p, MA_OWNED); 2902 n = p->p_suspcount; 2903 if (p == curproc) 2904 n++; 2905 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2906 PROC_SUNLOCK(p); 2907 p->p_flag &= ~P_WAITED; 2908 PROC_LOCK(p->p_pptr); 2909 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2910 CLD_TRAPPED : CLD_STOPPED); 2911 PROC_UNLOCK(p->p_pptr); 2912 PROC_SLOCK(p); 2913 } 2914} 2915 2916/* 2917 * Take the action for the specified signal 2918 * from the current set of pending signals. 2919 */ 2920int 2921postsig(sig) 2922 register int sig; 2923{ 2924 struct thread *td = curthread; 2925 register struct proc *p = td->td_proc; 2926 struct sigacts *ps; 2927 sig_t action; 2928 ksiginfo_t ksi; 2929 sigset_t returnmask; 2930 2931 KASSERT(sig != 0, ("postsig")); 2932 2933 PROC_LOCK_ASSERT(p, MA_OWNED); 2934 ps = p->p_sigacts; 2935 mtx_assert(&ps->ps_mtx, MA_OWNED); 2936 ksiginfo_init(&ksi); 2937 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 2938 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 2939 return (0); 2940 ksi.ksi_signo = sig; 2941 if (ksi.ksi_code == SI_TIMER) 2942 itimer_accept(p, ksi.ksi_timerid, &ksi); 2943 action = ps->ps_sigact[_SIG_IDX(sig)]; 2944#ifdef KTRACE 2945 if (KTRPOINT(td, KTR_PSIG)) 2946 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 2947 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 2948#endif 2949 if (p->p_stops & S_SIG) { 2950 mtx_unlock(&ps->ps_mtx); 2951 stopevent(p, S_SIG, sig); 2952 mtx_lock(&ps->ps_mtx); 2953 } 2954 2955 if (action == SIG_DFL) { 2956 /* 2957 * Default action, where the default is to kill 2958 * the process. (Other cases were ignored above.) 2959 */ 2960 mtx_unlock(&ps->ps_mtx); 2961 sigexit(td, sig); 2962 /* NOTREACHED */ 2963 } else { 2964 /* 2965 * If we get here, the signal must be caught. 2966 */ 2967 KASSERT(action != SIG_IGN && !SIGISMEMBER(td->td_sigmask, sig), 2968 ("postsig action")); 2969 /* 2970 * Set the new mask value and also defer further 2971 * occurrences of this signal. 2972 * 2973 * Special case: user has done a sigsuspend. Here the 2974 * current mask is not of interest, but rather the 2975 * mask from before the sigsuspend is what we want 2976 * restored after the signal processing is completed. 2977 */ 2978 if (td->td_pflags & TDP_OLDMASK) { 2979 returnmask = td->td_oldsigmask; 2980 td->td_pflags &= ~TDP_OLDMASK; 2981 } else 2982 returnmask = td->td_sigmask; 2983 2984 if (p->p_sig == sig) { 2985 p->p_code = 0; 2986 p->p_sig = 0; 2987 } 2988 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 2989 postsig_done(sig, td, ps); 2990 } 2991 return (1); 2992} 2993 2994/* 2995 * Kill the current process for stated reason. 2996 */ 2997void 2998killproc(p, why) 2999 struct proc *p; 3000 char *why; 3001{ 3002 3003 PROC_LOCK_ASSERT(p, MA_OWNED); 3004 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3005 p->p_comm); 3006 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3007 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3008 p->p_flag |= P_WKILLED; 3009 kern_psignal(p, SIGKILL); 3010} 3011 3012/* 3013 * Force the current process to exit with the specified signal, dumping core 3014 * if appropriate. We bypass the normal tests for masked and caught signals, 3015 * allowing unrecoverable failures to terminate the process without changing 3016 * signal state. Mark the accounting record with the signal termination. 3017 * If dumping core, save the signal number for the debugger. Calls exit and 3018 * does not return. 3019 */ 3020void 3021sigexit(td, sig) 3022 struct thread *td; 3023 int sig; 3024{ 3025 struct proc *p = td->td_proc; 3026 3027 PROC_LOCK_ASSERT(p, MA_OWNED); 3028 p->p_acflag |= AXSIG; 3029 /* 3030 * We must be single-threading to generate a core dump. This 3031 * ensures that the registers in the core file are up-to-date. 3032 * Also, the ELF dump handler assumes that the thread list doesn't 3033 * change out from under it. 3034 * 3035 * XXX If another thread attempts to single-thread before us 3036 * (e.g. via fork()), we won't get a dump at all. 3037 */ 3038 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 3039 p->p_sig = sig; 3040 /* 3041 * Log signals which would cause core dumps 3042 * (Log as LOG_INFO to appease those who don't want 3043 * these messages.) 3044 * XXX : Todo, as well as euid, write out ruid too 3045 * Note that coredump() drops proc lock. 3046 */ 3047 if (coredump(td) == 0) 3048 sig |= WCOREFLAG; 3049 if (kern_logsigexit) 3050 log(LOG_INFO, 3051 "pid %d (%s), uid %d: exited on signal %d%s\n", 3052 p->p_pid, p->p_comm, 3053 td->td_ucred ? td->td_ucred->cr_uid : -1, 3054 sig &~ WCOREFLAG, 3055 sig & WCOREFLAG ? " (core dumped)" : ""); 3056 } else 3057 PROC_UNLOCK(p); 3058 exit1(td, W_EXITCODE(0, sig)); 3059 /* NOTREACHED */ 3060} 3061 3062/* 3063 * Send queued SIGCHLD to parent when child process's state 3064 * is changed. 3065 */ 3066static void 3067sigparent(struct proc *p, int reason, int status) 3068{ 3069 PROC_LOCK_ASSERT(p, MA_OWNED); 3070 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3071 3072 if (p->p_ksi != NULL) { 3073 p->p_ksi->ksi_signo = SIGCHLD; 3074 p->p_ksi->ksi_code = reason; 3075 p->p_ksi->ksi_status = status; 3076 p->p_ksi->ksi_pid = p->p_pid; 3077 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3078 if (KSI_ONQ(p->p_ksi)) 3079 return; 3080 } 3081 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3082} 3083 3084static void 3085childproc_jobstate(struct proc *p, int reason, int sig) 3086{ 3087 struct sigacts *ps; 3088 3089 PROC_LOCK_ASSERT(p, MA_OWNED); 3090 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3091 3092 /* 3093 * Wake up parent sleeping in kern_wait(), also send 3094 * SIGCHLD to parent, but SIGCHLD does not guarantee 3095 * that parent will awake, because parent may masked 3096 * the signal. 3097 */ 3098 p->p_pptr->p_flag |= P_STATCHILD; 3099 wakeup(p->p_pptr); 3100 3101 ps = p->p_pptr->p_sigacts; 3102 mtx_lock(&ps->ps_mtx); 3103 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3104 mtx_unlock(&ps->ps_mtx); 3105 sigparent(p, reason, sig); 3106 } else 3107 mtx_unlock(&ps->ps_mtx); 3108} 3109 3110void 3111childproc_stopped(struct proc *p, int reason) 3112{ 3113 /* p_xstat is a plain signal number, not a full wait() status here. */ 3114 childproc_jobstate(p, reason, p->p_xstat); 3115} 3116 3117void 3118childproc_continued(struct proc *p) 3119{ 3120 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3121} 3122 3123void 3124childproc_exited(struct proc *p) 3125{ 3126 int reason; 3127 int xstat = p->p_xstat; /* convert to int */ 3128 int status; 3129 3130 if (WCOREDUMP(xstat)) 3131 reason = CLD_DUMPED, status = WTERMSIG(xstat); 3132 else if (WIFSIGNALED(xstat)) 3133 reason = CLD_KILLED, status = WTERMSIG(xstat); 3134 else 3135 reason = CLD_EXITED, status = WEXITSTATUS(xstat); 3136 /* 3137 * XXX avoid calling wakeup(p->p_pptr), the work is 3138 * done in exit1(). 3139 */ 3140 sigparent(p, reason, status); 3141} 3142 3143/* 3144 * We only have 1 character for the core count in the format 3145 * string, so the range will be 0-9 3146 */ 3147#define MAX_NUM_CORES 10 3148static int num_cores = 5; 3149 3150static int 3151sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3152{ 3153 int error; 3154 int new_val; 3155 3156 new_val = num_cores; 3157 error = sysctl_handle_int(oidp, &new_val, 0, req); 3158 if (error != 0 || req->newptr == NULL) 3159 return (error); 3160 if (new_val > MAX_NUM_CORES) 3161 new_val = MAX_NUM_CORES; 3162 if (new_val < 0) 3163 new_val = 0; 3164 num_cores = new_val; 3165 return (0); 3166} 3167SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3168 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3169 3170#if defined(COMPRESS_USER_CORES) 3171int compress_user_cores = 1; 3172SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RW, 3173 &compress_user_cores, 0, "Compression of user corefiles"); 3174 3175int compress_user_cores_gzlevel = -1; /* default level */ 3176SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RW, 3177 &compress_user_cores_gzlevel, -1, "Corefile gzip compression level"); 3178 3179#define GZ_SUFFIX ".gz" 3180#define GZ_SUFFIX_LEN 3 3181#endif 3182 3183static char corefilename[MAXPATHLEN] = {"%N.core"}; 3184TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3185SYSCTL_STRING(_kern, OID_AUTO, corefile, CTLFLAG_RW, corefilename, 3186 sizeof(corefilename), "Process corefile name format string"); 3187 3188/* 3189 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3190 * Expand the name described in corefilename, using name, uid, and pid 3191 * and open/create core file. 3192 * corefilename is a printf-like string, with three format specifiers: 3193 * %N name of process ("name") 3194 * %P process id (pid) 3195 * %U user id (uid) 3196 * For example, "%N.core" is the default; they can be disabled completely 3197 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3198 * This is controlled by the sysctl variable kern.corefile (see above). 3199 */ 3200static int 3201corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3202 int compress, struct vnode **vpp, char **namep) 3203{ 3204 struct nameidata nd; 3205 struct sbuf sb; 3206 const char *format; 3207 char *hostname, *name; 3208 int indexpos, i, error, cmode, flags, oflags; 3209 3210 hostname = NULL; 3211 format = corefilename; 3212 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3213 indexpos = -1; 3214 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3215 for (i = 0; format[i] != '\0'; i++) { 3216 switch (format[i]) { 3217 case '%': /* Format character */ 3218 i++; 3219 switch (format[i]) { 3220 case '%': 3221 sbuf_putc(&sb, '%'); 3222 break; 3223 case 'H': /* hostname */ 3224 if (hostname == NULL) { 3225 hostname = malloc(MAXHOSTNAMELEN, 3226 M_TEMP, M_WAITOK); 3227 } 3228 getcredhostname(td->td_ucred, hostname, 3229 MAXHOSTNAMELEN); 3230 sbuf_printf(&sb, "%s", hostname); 3231 break; 3232 case 'I': /* autoincrementing index */ 3233 sbuf_printf(&sb, "0"); 3234 indexpos = sbuf_len(&sb) - 1; 3235 break; 3236 case 'N': /* process name */ 3237 sbuf_printf(&sb, "%s", comm); 3238 break; 3239 case 'P': /* process id */ 3240 sbuf_printf(&sb, "%u", pid); 3241 break; 3242 case 'U': /* user id */ 3243 sbuf_printf(&sb, "%u", uid); 3244 break; 3245 default: 3246 log(LOG_ERR, 3247 "Unknown format character %c in " 3248 "corename `%s'\n", format[i], format); 3249 break; 3250 } 3251 break; 3252 default: 3253 sbuf_putc(&sb, format[i]); 3254 break; 3255 } 3256 } 3257 free(hostname, M_TEMP); 3258#ifdef COMPRESS_USER_CORES 3259 if (compress) 3260 sbuf_printf(&sb, GZ_SUFFIX); 3261#endif 3262 if (sbuf_error(&sb) != 0) { 3263 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3264 "long\n", (long)pid, comm, (u_long)uid); 3265 sbuf_delete(&sb); 3266 free(name, M_TEMP); 3267 return (ENOMEM); 3268 } 3269 sbuf_finish(&sb); 3270 sbuf_delete(&sb); 3271 3272 cmode = S_IRUSR | S_IWUSR; 3273 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3274 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3275 3276 /* 3277 * If the core format has a %I in it, then we need to check 3278 * for existing corefiles before returning a name. 3279 * To do this we iterate over 0..num_cores to find a 3280 * non-existing core file name to use. 3281 */ 3282 if (indexpos != -1) { 3283 for (i = 0; i < num_cores; i++) { 3284 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3285 name[indexpos] = '0' + i; 3286 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3287 error = vn_open_cred(&nd, &flags, cmode, oflags, 3288 td->td_ucred, NULL); 3289 if (error) { 3290 if (error == EEXIST) 3291 continue; 3292 log(LOG_ERR, 3293 "pid %d (%s), uid (%u): Path `%s' failed " 3294 "on initial open test, error = %d\n", 3295 pid, comm, uid, name, error); 3296 } 3297 goto out; 3298 } 3299 } 3300 3301 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3302 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3303 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3304out: 3305 if (error) { 3306#ifdef AUDIT 3307 audit_proc_coredump(td, name, error); 3308#endif 3309 free(name, M_TEMP); 3310 return (error); 3311 } 3312 NDFREE(&nd, NDF_ONLY_PNBUF); 3313 *vpp = nd.ni_vp; 3314 *namep = name; 3315 return (0); 3316} 3317 3318/* 3319 * Dump a process' core. The main routine does some 3320 * policy checking, and creates the name of the coredump; 3321 * then it passes on a vnode and a size limit to the process-specific 3322 * coredump routine if there is one; if there _is not_ one, it returns 3323 * ENOSYS; otherwise it returns the error from the process-specific routine. 3324 */ 3325 3326static int 3327coredump(struct thread *td) 3328{ 3329 struct proc *p = td->td_proc; 3330 struct ucred *cred = td->td_ucred; 3331 struct vnode *vp; 3332 struct flock lf; 3333 struct vattr vattr; 3334 int error, error1, locked; 3335 struct mount *mp; 3336 char *name; /* name of corefile */ 3337 off_t limit; 3338 int compress; 3339 3340#ifdef COMPRESS_USER_CORES 3341 compress = compress_user_cores; 3342#else 3343 compress = 0; 3344#endif 3345 PROC_LOCK_ASSERT(p, MA_OWNED); 3346 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3347 _STOPEVENT(p, S_CORE, 0); 3348 3349 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3350 (p->p_flag2 & P2_NOTRACE) != 0) { 3351 PROC_UNLOCK(p); 3352 return (EFAULT); 3353 } 3354 3355 /* 3356 * Note that the bulk of limit checking is done after 3357 * the corefile is created. The exception is if the limit 3358 * for corefiles is 0, in which case we don't bother 3359 * creating the corefile at all. This layout means that 3360 * a corefile is truncated instead of not being created, 3361 * if it is larger than the limit. 3362 */ 3363 limit = (off_t)lim_cur(p, RLIMIT_CORE); 3364 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3365 PROC_UNLOCK(p); 3366 return (EFBIG); 3367 } 3368 PROC_UNLOCK(p); 3369 3370restart: 3371 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, compress, 3372 &vp, &name); 3373 if (error != 0) 3374 return (error); 3375 3376 /* Don't dump to non-regular files or files with links. */ 3377 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3378 vattr.va_nlink != 1) { 3379 VOP_UNLOCK(vp, 0); 3380 error = EFAULT; 3381 goto close; 3382 } 3383 3384 VOP_UNLOCK(vp, 0); 3385 lf.l_whence = SEEK_SET; 3386 lf.l_start = 0; 3387 lf.l_len = 0; 3388 lf.l_type = F_WRLCK; 3389 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3390 3391 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) { 3392 lf.l_type = F_UNLCK; 3393 if (locked) 3394 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3395 if ((error = vn_close(vp, FWRITE, cred, td)) != 0) 3396 goto out; 3397 if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) 3398 goto out; 3399 free(name, M_TEMP); 3400 goto restart; 3401 } 3402 3403 VATTR_NULL(&vattr); 3404 vattr.va_size = 0; 3405 if (set_core_nodump_flag) 3406 vattr.va_flags = UF_NODUMP; 3407 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3408 VOP_SETATTR(vp, &vattr, cred); 3409 VOP_UNLOCK(vp, 0); 3410 vn_finished_write(mp); 3411 PROC_LOCK(p); 3412 p->p_acflag |= ACORE; 3413 PROC_UNLOCK(p); 3414 3415 if (p->p_sysent->sv_coredump != NULL) { 3416 error = p->p_sysent->sv_coredump(td, vp, limit, 3417 compress ? IMGACT_CORE_COMPRESS : 0); 3418 } else { 3419 error = ENOSYS; 3420 } 3421 3422 if (locked) { 3423 lf.l_type = F_UNLCK; 3424 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3425 } 3426close: 3427 error1 = vn_close(vp, FWRITE, cred, td); 3428 if (error == 0) 3429 error = error1; 3430out: 3431#ifdef AUDIT 3432 audit_proc_coredump(td, name, error); 3433#endif 3434 free(name, M_TEMP); 3435 return (error); 3436} 3437 3438/* 3439 * Nonexistent system call-- signal process (may want to handle it). Flag 3440 * error in case process won't see signal immediately (blocked or ignored). 3441 */ 3442#ifndef _SYS_SYSPROTO_H_ 3443struct nosys_args { 3444 int dummy; 3445}; 3446#endif 3447/* ARGSUSED */ 3448int 3449nosys(td, args) 3450 struct thread *td; 3451 struct nosys_args *args; 3452{ 3453 struct proc *p = td->td_proc; 3454 3455 PROC_LOCK(p); 3456 tdsignal(td, SIGSYS); 3457 PROC_UNLOCK(p); 3458 return (ENOSYS); 3459} 3460 3461/* 3462 * Send a SIGIO or SIGURG signal to a process or process group using stored 3463 * credentials rather than those of the current process. 3464 */ 3465void 3466pgsigio(sigiop, sig, checkctty) 3467 struct sigio **sigiop; 3468 int sig, checkctty; 3469{ 3470 ksiginfo_t ksi; 3471 struct sigio *sigio; 3472 3473 ksiginfo_init(&ksi); 3474 ksi.ksi_signo = sig; 3475 ksi.ksi_code = SI_KERNEL; 3476 3477 SIGIO_LOCK(); 3478 sigio = *sigiop; 3479 if (sigio == NULL) { 3480 SIGIO_UNLOCK(); 3481 return; 3482 } 3483 if (sigio->sio_pgid > 0) { 3484 PROC_LOCK(sigio->sio_proc); 3485 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3486 kern_psignal(sigio->sio_proc, sig); 3487 PROC_UNLOCK(sigio->sio_proc); 3488 } else if (sigio->sio_pgid < 0) { 3489 struct proc *p; 3490 3491 PGRP_LOCK(sigio->sio_pgrp); 3492 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3493 PROC_LOCK(p); 3494 if (p->p_state == PRS_NORMAL && 3495 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3496 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3497 kern_psignal(p, sig); 3498 PROC_UNLOCK(p); 3499 } 3500 PGRP_UNLOCK(sigio->sio_pgrp); 3501 } 3502 SIGIO_UNLOCK(); 3503} 3504 3505static int 3506filt_sigattach(struct knote *kn) 3507{ 3508 struct proc *p = curproc; 3509 3510 kn->kn_ptr.p_proc = p; 3511 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3512 3513 knlist_add(&p->p_klist, kn, 0); 3514 3515 return (0); 3516} 3517 3518static void 3519filt_sigdetach(struct knote *kn) 3520{ 3521 struct proc *p = kn->kn_ptr.p_proc; 3522 3523 knlist_remove(&p->p_klist, kn, 0); 3524} 3525 3526/* 3527 * signal knotes are shared with proc knotes, so we apply a mask to 3528 * the hint in order to differentiate them from process hints. This 3529 * could be avoided by using a signal-specific knote list, but probably 3530 * isn't worth the trouble. 3531 */ 3532static int 3533filt_signal(struct knote *kn, long hint) 3534{ 3535 3536 if (hint & NOTE_SIGNAL) { 3537 hint &= ~NOTE_SIGNAL; 3538 3539 if (kn->kn_id == hint) 3540 kn->kn_data++; 3541 } 3542 return (kn->kn_data != 0); 3543} 3544 3545struct sigacts * 3546sigacts_alloc(void) 3547{ 3548 struct sigacts *ps; 3549 3550 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3551 ps->ps_refcnt = 1; 3552 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3553 return (ps); 3554} 3555 3556void 3557sigacts_free(struct sigacts *ps) 3558{ 3559 3560 if (refcount_release(&ps->ps_refcnt) == 0) 3561 return; 3562 mtx_destroy(&ps->ps_mtx); 3563 free(ps, M_SUBPROC); 3564} 3565 3566struct sigacts * 3567sigacts_hold(struct sigacts *ps) 3568{ 3569 3570 refcount_acquire(&ps->ps_refcnt); 3571 return (ps); 3572} 3573 3574void 3575sigacts_copy(struct sigacts *dest, struct sigacts *src) 3576{ 3577 3578 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3579 mtx_lock(&src->ps_mtx); 3580 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3581 mtx_unlock(&src->ps_mtx); 3582} 3583 3584int 3585sigacts_shared(struct sigacts *ps) 3586{ 3587 3588 return (ps->ps_refcnt > 1); 3589} 3590