kern_sig.c revision 331643
1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * (c) UNIX System Laboratories, Inc. 7 * All or some portions of this file are derived from material licensed 8 * to the University of California by American Telephone and Telegraph 9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 10 * the permission of UNIX System Laboratories, Inc. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 37 */ 38 39#include <sys/cdefs.h> 40__FBSDID("$FreeBSD: stable/11/sys/kern/kern_sig.c 331643 2018-03-27 18:52:27Z dim $"); 41 42#include "opt_compat.h" 43#include "opt_gzio.h" 44#include "opt_ktrace.h" 45 46#include <sys/param.h> 47#include <sys/ctype.h> 48#include <sys/systm.h> 49#include <sys/signalvar.h> 50#include <sys/vnode.h> 51#include <sys/acct.h> 52#include <sys/bus.h> 53#include <sys/capsicum.h> 54#include <sys/condvar.h> 55#include <sys/event.h> 56#include <sys/fcntl.h> 57#include <sys/imgact.h> 58#include <sys/kernel.h> 59#include <sys/ktr.h> 60#include <sys/ktrace.h> 61#include <sys/lock.h> 62#include <sys/malloc.h> 63#include <sys/mutex.h> 64#include <sys/refcount.h> 65#include <sys/namei.h> 66#include <sys/proc.h> 67#include <sys/procdesc.h> 68#include <sys/posix4.h> 69#include <sys/pioctl.h> 70#include <sys/racct.h> 71#include <sys/resourcevar.h> 72#include <sys/sdt.h> 73#include <sys/sbuf.h> 74#include <sys/sleepqueue.h> 75#include <sys/smp.h> 76#include <sys/stat.h> 77#include <sys/sx.h> 78#include <sys/syscallsubr.h> 79#include <sys/sysctl.h> 80#include <sys/sysent.h> 81#include <sys/syslog.h> 82#include <sys/sysproto.h> 83#include <sys/timers.h> 84#include <sys/unistd.h> 85#include <sys/wait.h> 86#include <vm/vm.h> 87#include <vm/vm_extern.h> 88#include <vm/uma.h> 89 90#include <sys/jail.h> 91 92#include <machine/cpu.h> 93 94#include <security/audit/audit.h> 95 96#define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 97 98SDT_PROVIDER_DECLARE(proc); 99SDT_PROBE_DEFINE3(proc, , , signal__send, 100 "struct thread *", "struct proc *", "int"); 101SDT_PROBE_DEFINE2(proc, , , signal__clear, 102 "int", "ksiginfo_t *"); 103SDT_PROBE_DEFINE3(proc, , , signal__discard, 104 "struct thread *", "struct proc *", "int"); 105 106static int coredump(struct thread *); 107static int killpg1(struct thread *td, int sig, int pgid, int all, 108 ksiginfo_t *ksi); 109static int issignal(struct thread *td); 110static int sigprop(int sig); 111static void tdsigwakeup(struct thread *, int, sig_t, int); 112static int sig_suspend_threads(struct thread *, struct proc *, int); 113static int filt_sigattach(struct knote *kn); 114static void filt_sigdetach(struct knote *kn); 115static int filt_signal(struct knote *kn, long hint); 116static struct thread *sigtd(struct proc *p, int sig, int prop); 117static void sigqueue_start(void); 118 119static uma_zone_t ksiginfo_zone = NULL; 120struct filterops sig_filtops = { 121 .f_isfd = 0, 122 .f_attach = filt_sigattach, 123 .f_detach = filt_sigdetach, 124 .f_event = filt_signal, 125}; 126 127static int kern_logsigexit = 1; 128SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 129 &kern_logsigexit, 0, 130 "Log processes quitting on abnormal signals to syslog(3)"); 131 132static int kern_forcesigexit = 1; 133SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 134 &kern_forcesigexit, 0, "Force trap signal to be handled"); 135 136static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 137 "POSIX real time signal"); 138 139static int max_pending_per_proc = 128; 140SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 141 &max_pending_per_proc, 0, "Max pending signals per proc"); 142 143static int preallocate_siginfo = 1024; 144SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 145 &preallocate_siginfo, 0, "Preallocated signal memory size"); 146 147static int signal_overflow = 0; 148SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 149 &signal_overflow, 0, "Number of signals overflew"); 150 151static int signal_alloc_fail = 0; 152SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 153 &signal_alloc_fail, 0, "signals failed to be allocated"); 154 155static int kern_lognosys = 0; 156SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 157 "Log invalid syscalls"); 158 159SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 160 161/* 162 * Policy -- Can ucred cr1 send SIGIO to process cr2? 163 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 164 * in the right situations. 165 */ 166#define CANSIGIO(cr1, cr2) \ 167 ((cr1)->cr_uid == 0 || \ 168 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 169 (cr1)->cr_uid == (cr2)->cr_ruid || \ 170 (cr1)->cr_ruid == (cr2)->cr_uid || \ 171 (cr1)->cr_uid == (cr2)->cr_uid) 172 173static int sugid_coredump; 174SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 175 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 176 177static int capmode_coredump; 178SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 179 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 180 181static int do_coredump = 1; 182SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 183 &do_coredump, 0, "Enable/Disable coredumps"); 184 185static int set_core_nodump_flag = 0; 186SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 187 0, "Enable setting the NODUMP flag on coredump files"); 188 189static int coredump_devctl = 0; 190SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 191 0, "Generate a devctl notification when processes coredump"); 192 193/* 194 * Signal properties and actions. 195 * The array below categorizes the signals and their default actions 196 * according to the following properties: 197 */ 198#define SA_KILL 0x01 /* terminates process by default */ 199#define SA_CORE 0x02 /* ditto and coredumps */ 200#define SA_STOP 0x04 /* suspend process */ 201#define SA_TTYSTOP 0x08 /* ditto, from tty */ 202#define SA_IGNORE 0x10 /* ignore by default */ 203#define SA_CONT 0x20 /* continue if suspended */ 204#define SA_CANTMASK 0x40 /* non-maskable, catchable */ 205 206static int sigproptbl[NSIG] = { 207 SA_KILL, /* SIGHUP */ 208 SA_KILL, /* SIGINT */ 209 SA_KILL|SA_CORE, /* SIGQUIT */ 210 SA_KILL|SA_CORE, /* SIGILL */ 211 SA_KILL|SA_CORE, /* SIGTRAP */ 212 SA_KILL|SA_CORE, /* SIGABRT */ 213 SA_KILL|SA_CORE, /* SIGEMT */ 214 SA_KILL|SA_CORE, /* SIGFPE */ 215 SA_KILL, /* SIGKILL */ 216 SA_KILL|SA_CORE, /* SIGBUS */ 217 SA_KILL|SA_CORE, /* SIGSEGV */ 218 SA_KILL|SA_CORE, /* SIGSYS */ 219 SA_KILL, /* SIGPIPE */ 220 SA_KILL, /* SIGALRM */ 221 SA_KILL, /* SIGTERM */ 222 SA_IGNORE, /* SIGURG */ 223 SA_STOP, /* SIGSTOP */ 224 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 225 SA_IGNORE|SA_CONT, /* SIGCONT */ 226 SA_IGNORE, /* SIGCHLD */ 227 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 228 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 229 SA_IGNORE, /* SIGIO */ 230 SA_KILL, /* SIGXCPU */ 231 SA_KILL, /* SIGXFSZ */ 232 SA_KILL, /* SIGVTALRM */ 233 SA_KILL, /* SIGPROF */ 234 SA_IGNORE, /* SIGWINCH */ 235 SA_IGNORE, /* SIGINFO */ 236 SA_KILL, /* SIGUSR1 */ 237 SA_KILL, /* SIGUSR2 */ 238}; 239 240static void reschedule_signals(struct proc *p, sigset_t block, int flags); 241 242static void 243sigqueue_start(void) 244{ 245 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 246 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 247 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 248 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 249 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 250 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 251} 252 253ksiginfo_t * 254ksiginfo_alloc(int wait) 255{ 256 int flags; 257 258 flags = M_ZERO; 259 if (! wait) 260 flags |= M_NOWAIT; 261 if (ksiginfo_zone != NULL) 262 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 263 return (NULL); 264} 265 266void 267ksiginfo_free(ksiginfo_t *ksi) 268{ 269 uma_zfree(ksiginfo_zone, ksi); 270} 271 272static __inline int 273ksiginfo_tryfree(ksiginfo_t *ksi) 274{ 275 if (!(ksi->ksi_flags & KSI_EXT)) { 276 uma_zfree(ksiginfo_zone, ksi); 277 return (1); 278 } 279 return (0); 280} 281 282void 283sigqueue_init(sigqueue_t *list, struct proc *p) 284{ 285 SIGEMPTYSET(list->sq_signals); 286 SIGEMPTYSET(list->sq_kill); 287 SIGEMPTYSET(list->sq_ptrace); 288 TAILQ_INIT(&list->sq_list); 289 list->sq_proc = p; 290 list->sq_flags = SQ_INIT; 291} 292 293/* 294 * Get a signal's ksiginfo. 295 * Return: 296 * 0 - signal not found 297 * others - signal number 298 */ 299static int 300sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 301{ 302 struct proc *p = sq->sq_proc; 303 struct ksiginfo *ksi, *next; 304 int count = 0; 305 306 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 307 308 if (!SIGISMEMBER(sq->sq_signals, signo)) 309 return (0); 310 311 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 312 count++; 313 SIGDELSET(sq->sq_ptrace, signo); 314 si->ksi_flags |= KSI_PTRACE; 315 } 316 if (SIGISMEMBER(sq->sq_kill, signo)) { 317 count++; 318 if (count == 1) 319 SIGDELSET(sq->sq_kill, signo); 320 } 321 322 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 323 if (ksi->ksi_signo == signo) { 324 if (count == 0) { 325 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 326 ksi->ksi_sigq = NULL; 327 ksiginfo_copy(ksi, si); 328 if (ksiginfo_tryfree(ksi) && p != NULL) 329 p->p_pendingcnt--; 330 } 331 if (++count > 1) 332 break; 333 } 334 } 335 336 if (count <= 1) 337 SIGDELSET(sq->sq_signals, signo); 338 si->ksi_signo = signo; 339 return (signo); 340} 341 342void 343sigqueue_take(ksiginfo_t *ksi) 344{ 345 struct ksiginfo *kp; 346 struct proc *p; 347 sigqueue_t *sq; 348 349 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 350 return; 351 352 p = sq->sq_proc; 353 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 354 ksi->ksi_sigq = NULL; 355 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 356 p->p_pendingcnt--; 357 358 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 359 kp = TAILQ_NEXT(kp, ksi_link)) { 360 if (kp->ksi_signo == ksi->ksi_signo) 361 break; 362 } 363 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 364 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 365 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 366} 367 368static int 369sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 370{ 371 struct proc *p = sq->sq_proc; 372 struct ksiginfo *ksi; 373 int ret = 0; 374 375 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 376 377 /* 378 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 379 * for these signals. 380 */ 381 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 382 SIGADDSET(sq->sq_kill, signo); 383 goto out_set_bit; 384 } 385 386 /* directly insert the ksi, don't copy it */ 387 if (si->ksi_flags & KSI_INS) { 388 if (si->ksi_flags & KSI_HEAD) 389 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 390 else 391 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 392 si->ksi_sigq = sq; 393 goto out_set_bit; 394 } 395 396 if (__predict_false(ksiginfo_zone == NULL)) { 397 SIGADDSET(sq->sq_kill, signo); 398 goto out_set_bit; 399 } 400 401 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 402 signal_overflow++; 403 ret = EAGAIN; 404 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 405 signal_alloc_fail++; 406 ret = EAGAIN; 407 } else { 408 if (p != NULL) 409 p->p_pendingcnt++; 410 ksiginfo_copy(si, ksi); 411 ksi->ksi_signo = signo; 412 if (si->ksi_flags & KSI_HEAD) 413 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 414 else 415 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 416 ksi->ksi_sigq = sq; 417 } 418 419 if (ret != 0) { 420 if ((si->ksi_flags & KSI_PTRACE) != 0) { 421 SIGADDSET(sq->sq_ptrace, signo); 422 ret = 0; 423 goto out_set_bit; 424 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 425 (si->ksi_flags & KSI_SIGQ) == 0) { 426 SIGADDSET(sq->sq_kill, signo); 427 ret = 0; 428 goto out_set_bit; 429 } 430 return (ret); 431 } 432 433out_set_bit: 434 SIGADDSET(sq->sq_signals, signo); 435 return (ret); 436} 437 438void 439sigqueue_flush(sigqueue_t *sq) 440{ 441 struct proc *p = sq->sq_proc; 442 ksiginfo_t *ksi; 443 444 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 445 446 if (p != NULL) 447 PROC_LOCK_ASSERT(p, MA_OWNED); 448 449 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 450 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 451 ksi->ksi_sigq = NULL; 452 if (ksiginfo_tryfree(ksi) && p != NULL) 453 p->p_pendingcnt--; 454 } 455 456 SIGEMPTYSET(sq->sq_signals); 457 SIGEMPTYSET(sq->sq_kill); 458 SIGEMPTYSET(sq->sq_ptrace); 459} 460 461static void 462sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 463{ 464 sigset_t tmp; 465 struct proc *p1, *p2; 466 ksiginfo_t *ksi, *next; 467 468 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 469 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 470 p1 = src->sq_proc; 471 p2 = dst->sq_proc; 472 /* Move siginfo to target list */ 473 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 474 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 475 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 476 if (p1 != NULL) 477 p1->p_pendingcnt--; 478 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 479 ksi->ksi_sigq = dst; 480 if (p2 != NULL) 481 p2->p_pendingcnt++; 482 } 483 } 484 485 /* Move pending bits to target list */ 486 tmp = src->sq_kill; 487 SIGSETAND(tmp, *set); 488 SIGSETOR(dst->sq_kill, tmp); 489 SIGSETNAND(src->sq_kill, tmp); 490 491 tmp = src->sq_ptrace; 492 SIGSETAND(tmp, *set); 493 SIGSETOR(dst->sq_ptrace, tmp); 494 SIGSETNAND(src->sq_ptrace, tmp); 495 496 tmp = src->sq_signals; 497 SIGSETAND(tmp, *set); 498 SIGSETOR(dst->sq_signals, tmp); 499 SIGSETNAND(src->sq_signals, tmp); 500} 501 502#if 0 503static void 504sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 505{ 506 sigset_t set; 507 508 SIGEMPTYSET(set); 509 SIGADDSET(set, signo); 510 sigqueue_move_set(src, dst, &set); 511} 512#endif 513 514static void 515sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 516{ 517 struct proc *p = sq->sq_proc; 518 ksiginfo_t *ksi, *next; 519 520 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 521 522 /* Remove siginfo queue */ 523 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 524 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 525 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 526 ksi->ksi_sigq = NULL; 527 if (ksiginfo_tryfree(ksi) && p != NULL) 528 p->p_pendingcnt--; 529 } 530 } 531 SIGSETNAND(sq->sq_kill, *set); 532 SIGSETNAND(sq->sq_ptrace, *set); 533 SIGSETNAND(sq->sq_signals, *set); 534} 535 536void 537sigqueue_delete(sigqueue_t *sq, int signo) 538{ 539 sigset_t set; 540 541 SIGEMPTYSET(set); 542 SIGADDSET(set, signo); 543 sigqueue_delete_set(sq, &set); 544} 545 546/* Remove a set of signals for a process */ 547static void 548sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 549{ 550 sigqueue_t worklist; 551 struct thread *td0; 552 553 PROC_LOCK_ASSERT(p, MA_OWNED); 554 555 sigqueue_init(&worklist, NULL); 556 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 557 558 FOREACH_THREAD_IN_PROC(p, td0) 559 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 560 561 sigqueue_flush(&worklist); 562} 563 564void 565sigqueue_delete_proc(struct proc *p, int signo) 566{ 567 sigset_t set; 568 569 SIGEMPTYSET(set); 570 SIGADDSET(set, signo); 571 sigqueue_delete_set_proc(p, &set); 572} 573 574static void 575sigqueue_delete_stopmask_proc(struct proc *p) 576{ 577 sigset_t set; 578 579 SIGEMPTYSET(set); 580 SIGADDSET(set, SIGSTOP); 581 SIGADDSET(set, SIGTSTP); 582 SIGADDSET(set, SIGTTIN); 583 SIGADDSET(set, SIGTTOU); 584 sigqueue_delete_set_proc(p, &set); 585} 586 587/* 588 * Determine signal that should be delivered to thread td, the current 589 * thread, 0 if none. If there is a pending stop signal with default 590 * action, the process stops in issignal(). 591 */ 592int 593cursig(struct thread *td) 594{ 595 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 596 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 597 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 598 return (SIGPENDING(td) ? issignal(td) : 0); 599} 600 601/* 602 * Arrange for ast() to handle unmasked pending signals on return to user 603 * mode. This must be called whenever a signal is added to td_sigqueue or 604 * unmasked in td_sigmask. 605 */ 606void 607signotify(struct thread *td) 608{ 609 struct proc *p; 610 611 p = td->td_proc; 612 613 PROC_LOCK_ASSERT(p, MA_OWNED); 614 615 if (SIGPENDING(td)) { 616 thread_lock(td); 617 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 618 thread_unlock(td); 619 } 620} 621 622int 623sigonstack(size_t sp) 624{ 625 struct thread *td = curthread; 626 627 return ((td->td_pflags & TDP_ALTSTACK) ? 628#if defined(COMPAT_43) 629 ((td->td_sigstk.ss_size == 0) ? 630 (td->td_sigstk.ss_flags & SS_ONSTACK) : 631 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size)) 632#else 633 ((sp - (size_t)td->td_sigstk.ss_sp) < td->td_sigstk.ss_size) 634#endif 635 : 0); 636} 637 638static __inline int 639sigprop(int sig) 640{ 641 642 if (sig > 0 && sig < NSIG) 643 return (sigproptbl[_SIG_IDX(sig)]); 644 return (0); 645} 646 647int 648sig_ffs(sigset_t *set) 649{ 650 int i; 651 652 for (i = 0; i < _SIG_WORDS; i++) 653 if (set->__bits[i]) 654 return (ffs(set->__bits[i]) + (i * 32)); 655 return (0); 656} 657 658static bool 659sigact_flag_test(const struct sigaction *act, int flag) 660{ 661 662 /* 663 * SA_SIGINFO is reset when signal disposition is set to 664 * ignore or default. Other flags are kept according to user 665 * settings. 666 */ 667 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 668 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 669 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 670} 671 672/* 673 * kern_sigaction 674 * sigaction 675 * freebsd4_sigaction 676 * osigaction 677 */ 678int 679kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 680 struct sigaction *oact, int flags) 681{ 682 struct sigacts *ps; 683 struct proc *p = td->td_proc; 684 685 if (!_SIG_VALID(sig)) 686 return (EINVAL); 687 if (act != NULL && act->sa_handler != SIG_DFL && 688 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 689 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 690 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 691 return (EINVAL); 692 693 PROC_LOCK(p); 694 ps = p->p_sigacts; 695 mtx_lock(&ps->ps_mtx); 696 if (oact) { 697 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 698 oact->sa_flags = 0; 699 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 700 oact->sa_flags |= SA_ONSTACK; 701 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 702 oact->sa_flags |= SA_RESTART; 703 if (SIGISMEMBER(ps->ps_sigreset, sig)) 704 oact->sa_flags |= SA_RESETHAND; 705 if (SIGISMEMBER(ps->ps_signodefer, sig)) 706 oact->sa_flags |= SA_NODEFER; 707 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 708 oact->sa_flags |= SA_SIGINFO; 709 oact->sa_sigaction = 710 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 711 } else 712 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 713 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 714 oact->sa_flags |= SA_NOCLDSTOP; 715 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 716 oact->sa_flags |= SA_NOCLDWAIT; 717 } 718 if (act) { 719 if ((sig == SIGKILL || sig == SIGSTOP) && 720 act->sa_handler != SIG_DFL) { 721 mtx_unlock(&ps->ps_mtx); 722 PROC_UNLOCK(p); 723 return (EINVAL); 724 } 725 726 /* 727 * Change setting atomically. 728 */ 729 730 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 731 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 732 if (sigact_flag_test(act, SA_SIGINFO)) { 733 ps->ps_sigact[_SIG_IDX(sig)] = 734 (__sighandler_t *)act->sa_sigaction; 735 SIGADDSET(ps->ps_siginfo, sig); 736 } else { 737 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 738 SIGDELSET(ps->ps_siginfo, sig); 739 } 740 if (!sigact_flag_test(act, SA_RESTART)) 741 SIGADDSET(ps->ps_sigintr, sig); 742 else 743 SIGDELSET(ps->ps_sigintr, sig); 744 if (sigact_flag_test(act, SA_ONSTACK)) 745 SIGADDSET(ps->ps_sigonstack, sig); 746 else 747 SIGDELSET(ps->ps_sigonstack, sig); 748 if (sigact_flag_test(act, SA_RESETHAND)) 749 SIGADDSET(ps->ps_sigreset, sig); 750 else 751 SIGDELSET(ps->ps_sigreset, sig); 752 if (sigact_flag_test(act, SA_NODEFER)) 753 SIGADDSET(ps->ps_signodefer, sig); 754 else 755 SIGDELSET(ps->ps_signodefer, sig); 756 if (sig == SIGCHLD) { 757 if (act->sa_flags & SA_NOCLDSTOP) 758 ps->ps_flag |= PS_NOCLDSTOP; 759 else 760 ps->ps_flag &= ~PS_NOCLDSTOP; 761 if (act->sa_flags & SA_NOCLDWAIT) { 762 /* 763 * Paranoia: since SA_NOCLDWAIT is implemented 764 * by reparenting the dying child to PID 1 (and 765 * trust it to reap the zombie), PID 1 itself 766 * is forbidden to set SA_NOCLDWAIT. 767 */ 768 if (p->p_pid == 1) 769 ps->ps_flag &= ~PS_NOCLDWAIT; 770 else 771 ps->ps_flag |= PS_NOCLDWAIT; 772 } else 773 ps->ps_flag &= ~PS_NOCLDWAIT; 774 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 775 ps->ps_flag |= PS_CLDSIGIGN; 776 else 777 ps->ps_flag &= ~PS_CLDSIGIGN; 778 } 779 /* 780 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 781 * and for signals set to SIG_DFL where the default is to 782 * ignore. However, don't put SIGCONT in ps_sigignore, as we 783 * have to restart the process. 784 */ 785 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 786 (sigprop(sig) & SA_IGNORE && 787 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 788 /* never to be seen again */ 789 sigqueue_delete_proc(p, sig); 790 if (sig != SIGCONT) 791 /* easier in psignal */ 792 SIGADDSET(ps->ps_sigignore, sig); 793 SIGDELSET(ps->ps_sigcatch, sig); 794 } else { 795 SIGDELSET(ps->ps_sigignore, sig); 796 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 797 SIGDELSET(ps->ps_sigcatch, sig); 798 else 799 SIGADDSET(ps->ps_sigcatch, sig); 800 } 801#ifdef COMPAT_FREEBSD4 802 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 803 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 804 (flags & KSA_FREEBSD4) == 0) 805 SIGDELSET(ps->ps_freebsd4, sig); 806 else 807 SIGADDSET(ps->ps_freebsd4, sig); 808#endif 809#ifdef COMPAT_43 810 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 811 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 812 (flags & KSA_OSIGSET) == 0) 813 SIGDELSET(ps->ps_osigset, sig); 814 else 815 SIGADDSET(ps->ps_osigset, sig); 816#endif 817 } 818 mtx_unlock(&ps->ps_mtx); 819 PROC_UNLOCK(p); 820 return (0); 821} 822 823#ifndef _SYS_SYSPROTO_H_ 824struct sigaction_args { 825 int sig; 826 struct sigaction *act; 827 struct sigaction *oact; 828}; 829#endif 830int 831sys_sigaction(struct thread *td, struct sigaction_args *uap) 832{ 833 struct sigaction act, oact; 834 struct sigaction *actp, *oactp; 835 int error; 836 837 actp = (uap->act != NULL) ? &act : NULL; 838 oactp = (uap->oact != NULL) ? &oact : NULL; 839 if (actp) { 840 error = copyin(uap->act, actp, sizeof(act)); 841 if (error) 842 return (error); 843 } 844 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 845 if (oactp && !error) 846 error = copyout(oactp, uap->oact, sizeof(oact)); 847 return (error); 848} 849 850#ifdef COMPAT_FREEBSD4 851#ifndef _SYS_SYSPROTO_H_ 852struct freebsd4_sigaction_args { 853 int sig; 854 struct sigaction *act; 855 struct sigaction *oact; 856}; 857#endif 858int 859freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 860{ 861 struct sigaction act, oact; 862 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(struct thread *td, struct osigaction_args *uap) 890{ 891 struct osigaction sa; 892 struct sigaction nsa, osa; 893 struct sigaction *nsap, *osap; 894 int error; 895 896 if (uap->signum <= 0 || uap->signum >= ONSIG) 897 return (EINVAL); 898 899 nsap = (uap->nsa != NULL) ? &nsa : NULL; 900 osap = (uap->osa != NULL) ? &osa : NULL; 901 902 if (nsap) { 903 error = copyin(uap->nsa, &sa, sizeof(sa)); 904 if (error) 905 return (error); 906 nsap->sa_handler = sa.sa_handler; 907 nsap->sa_flags = sa.sa_flags; 908 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 909 } 910 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 911 if (osap && !error) { 912 sa.sa_handler = osap->sa_handler; 913 sa.sa_flags = osap->sa_flags; 914 SIG2OSIG(osap->sa_mask, sa.sa_mask); 915 error = copyout(&sa, uap->osa, sizeof(sa)); 916 } 917 return (error); 918} 919 920#if !defined(__i386__) 921/* Avoid replicating the same stub everywhere */ 922int 923osigreturn(struct thread *td, struct osigreturn_args *uap) 924{ 925 926 return (nosys(td, (struct nosys_args *)uap)); 927} 928#endif 929#endif /* COMPAT_43 */ 930 931/* 932 * Initialize signal state for process 0; 933 * set to ignore signals that are ignored by default. 934 */ 935void 936siginit(struct proc *p) 937{ 938 int i; 939 struct sigacts *ps; 940 941 PROC_LOCK(p); 942 ps = p->p_sigacts; 943 mtx_lock(&ps->ps_mtx); 944 for (i = 1; i <= NSIG; i++) { 945 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 946 SIGADDSET(ps->ps_sigignore, i); 947 } 948 } 949 mtx_unlock(&ps->ps_mtx); 950 PROC_UNLOCK(p); 951} 952 953/* 954 * Reset specified signal to the default disposition. 955 */ 956static void 957sigdflt(struct sigacts *ps, int sig) 958{ 959 960 mtx_assert(&ps->ps_mtx, MA_OWNED); 961 SIGDELSET(ps->ps_sigcatch, sig); 962 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 963 SIGADDSET(ps->ps_sigignore, sig); 964 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 965 SIGDELSET(ps->ps_siginfo, sig); 966} 967 968/* 969 * Reset signals for an exec of the specified process. 970 */ 971void 972execsigs(struct proc *p) 973{ 974 sigset_t osigignore; 975 struct sigacts *ps; 976 int sig; 977 struct thread *td; 978 979 /* 980 * Reset caught signals. Held signals remain held 981 * through td_sigmask (unless they were caught, 982 * and are now ignored by default). 983 */ 984 PROC_LOCK_ASSERT(p, MA_OWNED); 985 ps = p->p_sigacts; 986 mtx_lock(&ps->ps_mtx); 987 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 988 sig = sig_ffs(&ps->ps_sigcatch); 989 sigdflt(ps, sig); 990 if ((sigprop(sig) & SA_IGNORE) != 0) 991 sigqueue_delete_proc(p, sig); 992 } 993 994 /* 995 * As CloudABI processes cannot modify signal handlers, fully 996 * reset all signals to their default behavior. Do ignore 997 * SIGPIPE, as it would otherwise be impossible to recover from 998 * writes to broken pipes and sockets. 999 */ 1000 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1001 osigignore = ps->ps_sigignore; 1002 while (SIGNOTEMPTY(osigignore)) { 1003 sig = sig_ffs(&osigignore); 1004 SIGDELSET(osigignore, sig); 1005 if (sig != SIGPIPE) 1006 sigdflt(ps, sig); 1007 } 1008 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1009 } 1010 1011 /* 1012 * Reset stack state to the user stack. 1013 * Clear set of signals caught on the signal stack. 1014 */ 1015 td = curthread; 1016 MPASS(td->td_proc == p); 1017 td->td_sigstk.ss_flags = SS_DISABLE; 1018 td->td_sigstk.ss_size = 0; 1019 td->td_sigstk.ss_sp = 0; 1020 td->td_pflags &= ~TDP_ALTSTACK; 1021 /* 1022 * Reset no zombies if child dies flag as Solaris does. 1023 */ 1024 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1025 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1026 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1027 mtx_unlock(&ps->ps_mtx); 1028} 1029 1030/* 1031 * kern_sigprocmask() 1032 * 1033 * Manipulate signal mask. 1034 */ 1035int 1036kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1037 int flags) 1038{ 1039 sigset_t new_block, oset1; 1040 struct proc *p; 1041 int error; 1042 1043 p = td->td_proc; 1044 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1045 PROC_LOCK_ASSERT(p, MA_OWNED); 1046 else 1047 PROC_LOCK(p); 1048 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1049 ? MA_OWNED : MA_NOTOWNED); 1050 if (oset != NULL) 1051 *oset = td->td_sigmask; 1052 1053 error = 0; 1054 if (set != NULL) { 1055 switch (how) { 1056 case SIG_BLOCK: 1057 SIG_CANTMASK(*set); 1058 oset1 = td->td_sigmask; 1059 SIGSETOR(td->td_sigmask, *set); 1060 new_block = td->td_sigmask; 1061 SIGSETNAND(new_block, oset1); 1062 break; 1063 case SIG_UNBLOCK: 1064 SIGSETNAND(td->td_sigmask, *set); 1065 signotify(td); 1066 goto out; 1067 case SIG_SETMASK: 1068 SIG_CANTMASK(*set); 1069 oset1 = td->td_sigmask; 1070 if (flags & SIGPROCMASK_OLD) 1071 SIGSETLO(td->td_sigmask, *set); 1072 else 1073 td->td_sigmask = *set; 1074 new_block = td->td_sigmask; 1075 SIGSETNAND(new_block, oset1); 1076 signotify(td); 1077 break; 1078 default: 1079 error = EINVAL; 1080 goto out; 1081 } 1082 1083 /* 1084 * The new_block set contains signals that were not previously 1085 * blocked, but are blocked now. 1086 * 1087 * In case we block any signal that was not previously blocked 1088 * for td, and process has the signal pending, try to schedule 1089 * signal delivery to some thread that does not block the 1090 * signal, possibly waking it up. 1091 */ 1092 if (p->p_numthreads != 1) 1093 reschedule_signals(p, new_block, flags); 1094 } 1095 1096out: 1097 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1098 PROC_UNLOCK(p); 1099 return (error); 1100} 1101 1102#ifndef _SYS_SYSPROTO_H_ 1103struct sigprocmask_args { 1104 int how; 1105 const sigset_t *set; 1106 sigset_t *oset; 1107}; 1108#endif 1109int 1110sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1111{ 1112 sigset_t set, oset; 1113 sigset_t *setp, *osetp; 1114 int error; 1115 1116 setp = (uap->set != NULL) ? &set : NULL; 1117 osetp = (uap->oset != NULL) ? &oset : NULL; 1118 if (setp) { 1119 error = copyin(uap->set, setp, sizeof(set)); 1120 if (error) 1121 return (error); 1122 } 1123 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1124 if (osetp && !error) { 1125 error = copyout(osetp, uap->oset, sizeof(oset)); 1126 } 1127 return (error); 1128} 1129 1130#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1131#ifndef _SYS_SYSPROTO_H_ 1132struct osigprocmask_args { 1133 int how; 1134 osigset_t mask; 1135}; 1136#endif 1137int 1138osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1139{ 1140 sigset_t set, oset; 1141 int error; 1142 1143 OSIG2SIG(uap->mask, set); 1144 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1145 SIG2OSIG(oset, td->td_retval[0]); 1146 return (error); 1147} 1148#endif /* COMPAT_43 */ 1149 1150int 1151sys_sigwait(struct thread *td, struct sigwait_args *uap) 1152{ 1153 ksiginfo_t ksi; 1154 sigset_t set; 1155 int error; 1156 1157 error = copyin(uap->set, &set, sizeof(set)); 1158 if (error) { 1159 td->td_retval[0] = error; 1160 return (0); 1161 } 1162 1163 error = kern_sigtimedwait(td, set, &ksi, NULL); 1164 if (error) { 1165 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1166 error = ERESTART; 1167 if (error == ERESTART) 1168 return (error); 1169 td->td_retval[0] = error; 1170 return (0); 1171 } 1172 1173 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1174 td->td_retval[0] = error; 1175 return (0); 1176} 1177 1178int 1179sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1180{ 1181 struct timespec ts; 1182 struct timespec *timeout; 1183 sigset_t set; 1184 ksiginfo_t ksi; 1185 int error; 1186 1187 if (uap->timeout) { 1188 error = copyin(uap->timeout, &ts, sizeof(ts)); 1189 if (error) 1190 return (error); 1191 1192 timeout = &ts; 1193 } else 1194 timeout = NULL; 1195 1196 error = copyin(uap->set, &set, sizeof(set)); 1197 if (error) 1198 return (error); 1199 1200 error = kern_sigtimedwait(td, set, &ksi, timeout); 1201 if (error) 1202 return (error); 1203 1204 if (uap->info) 1205 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1206 1207 if (error == 0) 1208 td->td_retval[0] = ksi.ksi_signo; 1209 return (error); 1210} 1211 1212int 1213sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1214{ 1215 ksiginfo_t ksi; 1216 sigset_t set; 1217 int error; 1218 1219 error = copyin(uap->set, &set, sizeof(set)); 1220 if (error) 1221 return (error); 1222 1223 error = kern_sigtimedwait(td, set, &ksi, NULL); 1224 if (error) 1225 return (error); 1226 1227 if (uap->info) 1228 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1229 1230 if (error == 0) 1231 td->td_retval[0] = ksi.ksi_signo; 1232 return (error); 1233} 1234 1235static void 1236proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1237{ 1238 struct thread *thr; 1239 1240 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1241 if (thr == td) 1242 thr->td_si = *si; 1243 else 1244 thr->td_si.si_signo = 0; 1245 } 1246} 1247 1248int 1249kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1250 struct timespec *timeout) 1251{ 1252 struct sigacts *ps; 1253 sigset_t saved_mask, new_block; 1254 struct proc *p; 1255 int error, sig, timo, timevalid = 0; 1256 struct timespec rts, ets, ts; 1257 struct timeval tv; 1258 1259 p = td->td_proc; 1260 error = 0; 1261 ets.tv_sec = 0; 1262 ets.tv_nsec = 0; 1263 1264 if (timeout != NULL) { 1265 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1266 timevalid = 1; 1267 getnanouptime(&rts); 1268 ets = rts; 1269 timespecadd(&ets, timeout); 1270 } 1271 } 1272 ksiginfo_init(ksi); 1273 /* Some signals can not be waited for. */ 1274 SIG_CANTMASK(waitset); 1275 ps = p->p_sigacts; 1276 PROC_LOCK(p); 1277 saved_mask = td->td_sigmask; 1278 SIGSETNAND(td->td_sigmask, waitset); 1279 for (;;) { 1280 mtx_lock(&ps->ps_mtx); 1281 sig = cursig(td); 1282 mtx_unlock(&ps->ps_mtx); 1283 KASSERT(sig >= 0, ("sig %d", sig)); 1284 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1285 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1286 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1287 error = 0; 1288 break; 1289 } 1290 } 1291 1292 if (error != 0) 1293 break; 1294 1295 /* 1296 * POSIX says this must be checked after looking for pending 1297 * signals. 1298 */ 1299 if (timeout != NULL) { 1300 if (!timevalid) { 1301 error = EINVAL; 1302 break; 1303 } 1304 getnanouptime(&rts); 1305 if (timespeccmp(&rts, &ets, >=)) { 1306 error = EAGAIN; 1307 break; 1308 } 1309 ts = ets; 1310 timespecsub(&ts, &rts); 1311 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1312 timo = tvtohz(&tv); 1313 } else { 1314 timo = 0; 1315 } 1316 1317 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1318 1319 if (timeout != NULL) { 1320 if (error == ERESTART) { 1321 /* Timeout can not be restarted. */ 1322 error = EINTR; 1323 } else if (error == EAGAIN) { 1324 /* We will calculate timeout by ourself. */ 1325 error = 0; 1326 } 1327 } 1328 } 1329 1330 new_block = saved_mask; 1331 SIGSETNAND(new_block, td->td_sigmask); 1332 td->td_sigmask = saved_mask; 1333 /* 1334 * Fewer signals can be delivered to us, reschedule signal 1335 * notification. 1336 */ 1337 if (p->p_numthreads != 1) 1338 reschedule_signals(p, new_block, 0); 1339 1340 if (error == 0) { 1341 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1342 1343 if (ksi->ksi_code == SI_TIMER) 1344 itimer_accept(p, ksi->ksi_timerid, ksi); 1345 1346#ifdef KTRACE 1347 if (KTRPOINT(td, KTR_PSIG)) { 1348 sig_t action; 1349 1350 mtx_lock(&ps->ps_mtx); 1351 action = ps->ps_sigact[_SIG_IDX(sig)]; 1352 mtx_unlock(&ps->ps_mtx); 1353 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1354 } 1355#endif 1356 if (sig == SIGKILL) { 1357 proc_td_siginfo_capture(td, &ksi->ksi_info); 1358 sigexit(td, sig); 1359 } 1360 } 1361 PROC_UNLOCK(p); 1362 return (error); 1363} 1364 1365#ifndef _SYS_SYSPROTO_H_ 1366struct sigpending_args { 1367 sigset_t *set; 1368}; 1369#endif 1370int 1371sys_sigpending(struct thread *td, struct sigpending_args *uap) 1372{ 1373 struct proc *p = td->td_proc; 1374 sigset_t pending; 1375 1376 PROC_LOCK(p); 1377 pending = p->p_sigqueue.sq_signals; 1378 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1379 PROC_UNLOCK(p); 1380 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1381} 1382 1383#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1384#ifndef _SYS_SYSPROTO_H_ 1385struct osigpending_args { 1386 int dummy; 1387}; 1388#endif 1389int 1390osigpending(struct thread *td, struct osigpending_args *uap) 1391{ 1392 struct proc *p = td->td_proc; 1393 sigset_t pending; 1394 1395 PROC_LOCK(p); 1396 pending = p->p_sigqueue.sq_signals; 1397 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1398 PROC_UNLOCK(p); 1399 SIG2OSIG(pending, td->td_retval[0]); 1400 return (0); 1401} 1402#endif /* COMPAT_43 */ 1403 1404#if defined(COMPAT_43) 1405/* 1406 * Generalized interface signal handler, 4.3-compatible. 1407 */ 1408#ifndef _SYS_SYSPROTO_H_ 1409struct osigvec_args { 1410 int signum; 1411 struct sigvec *nsv; 1412 struct sigvec *osv; 1413}; 1414#endif 1415/* ARGSUSED */ 1416int 1417osigvec(struct thread *td, struct osigvec_args *uap) 1418{ 1419 struct sigvec vec; 1420 struct sigaction nsa, osa; 1421 struct sigaction *nsap, *osap; 1422 int error; 1423 1424 if (uap->signum <= 0 || uap->signum >= ONSIG) 1425 return (EINVAL); 1426 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1427 osap = (uap->osv != NULL) ? &osa : NULL; 1428 if (nsap) { 1429 error = copyin(uap->nsv, &vec, sizeof(vec)); 1430 if (error) 1431 return (error); 1432 nsap->sa_handler = vec.sv_handler; 1433 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1434 nsap->sa_flags = vec.sv_flags; 1435 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1436 } 1437 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1438 if (osap && !error) { 1439 vec.sv_handler = osap->sa_handler; 1440 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1441 vec.sv_flags = osap->sa_flags; 1442 vec.sv_flags &= ~SA_NOCLDWAIT; 1443 vec.sv_flags ^= SA_RESTART; 1444 error = copyout(&vec, uap->osv, sizeof(vec)); 1445 } 1446 return (error); 1447} 1448 1449#ifndef _SYS_SYSPROTO_H_ 1450struct osigblock_args { 1451 int mask; 1452}; 1453#endif 1454int 1455osigblock(struct thread *td, struct osigblock_args *uap) 1456{ 1457 sigset_t set, oset; 1458 1459 OSIG2SIG(uap->mask, set); 1460 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1461 SIG2OSIG(oset, td->td_retval[0]); 1462 return (0); 1463} 1464 1465#ifndef _SYS_SYSPROTO_H_ 1466struct osigsetmask_args { 1467 int mask; 1468}; 1469#endif 1470int 1471osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1472{ 1473 sigset_t set, oset; 1474 1475 OSIG2SIG(uap->mask, set); 1476 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1477 SIG2OSIG(oset, td->td_retval[0]); 1478 return (0); 1479} 1480#endif /* COMPAT_43 */ 1481 1482/* 1483 * Suspend calling thread until signal, providing mask to be set in the 1484 * meantime. 1485 */ 1486#ifndef _SYS_SYSPROTO_H_ 1487struct sigsuspend_args { 1488 const sigset_t *sigmask; 1489}; 1490#endif 1491/* ARGSUSED */ 1492int 1493sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1494{ 1495 sigset_t mask; 1496 int error; 1497 1498 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1499 if (error) 1500 return (error); 1501 return (kern_sigsuspend(td, mask)); 1502} 1503 1504int 1505kern_sigsuspend(struct thread *td, sigset_t mask) 1506{ 1507 struct proc *p = td->td_proc; 1508 int has_sig, sig; 1509 1510 /* 1511 * When returning from sigsuspend, we want 1512 * the old mask to be restored after the 1513 * signal handler has finished. Thus, we 1514 * save it here and mark the sigacts structure 1515 * to indicate this. 1516 */ 1517 PROC_LOCK(p); 1518 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1519 SIGPROCMASK_PROC_LOCKED); 1520 td->td_pflags |= TDP_OLDMASK; 1521 1522 /* 1523 * Process signals now. Otherwise, we can get spurious wakeup 1524 * due to signal entered process queue, but delivered to other 1525 * thread. But sigsuspend should return only on signal 1526 * delivery. 1527 */ 1528 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1529 for (has_sig = 0; !has_sig;) { 1530 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1531 0) == 0) 1532 /* void */; 1533 thread_suspend_check(0); 1534 mtx_lock(&p->p_sigacts->ps_mtx); 1535 while ((sig = cursig(td)) != 0) { 1536 KASSERT(sig >= 0, ("sig %d", sig)); 1537 has_sig += postsig(sig); 1538 } 1539 mtx_unlock(&p->p_sigacts->ps_mtx); 1540 } 1541 PROC_UNLOCK(p); 1542 td->td_errno = EINTR; 1543 td->td_pflags |= TDP_NERRNO; 1544 return (EJUSTRETURN); 1545} 1546 1547#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1548/* 1549 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1550 * convention: libc stub passes mask, not pointer, to save a copyin. 1551 */ 1552#ifndef _SYS_SYSPROTO_H_ 1553struct osigsuspend_args { 1554 osigset_t mask; 1555}; 1556#endif 1557/* ARGSUSED */ 1558int 1559osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1560{ 1561 sigset_t mask; 1562 1563 OSIG2SIG(uap->mask, mask); 1564 return (kern_sigsuspend(td, mask)); 1565} 1566#endif /* COMPAT_43 */ 1567 1568#if defined(COMPAT_43) 1569#ifndef _SYS_SYSPROTO_H_ 1570struct osigstack_args { 1571 struct sigstack *nss; 1572 struct sigstack *oss; 1573}; 1574#endif 1575/* ARGSUSED */ 1576int 1577osigstack(struct thread *td, struct osigstack_args *uap) 1578{ 1579 struct sigstack nss, oss; 1580 int error = 0; 1581 1582 if (uap->nss != NULL) { 1583 error = copyin(uap->nss, &nss, sizeof(nss)); 1584 if (error) 1585 return (error); 1586 } 1587 oss.ss_sp = td->td_sigstk.ss_sp; 1588 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1589 if (uap->nss != NULL) { 1590 td->td_sigstk.ss_sp = nss.ss_sp; 1591 td->td_sigstk.ss_size = 0; 1592 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1593 td->td_pflags |= TDP_ALTSTACK; 1594 } 1595 if (uap->oss != NULL) 1596 error = copyout(&oss, uap->oss, sizeof(oss)); 1597 1598 return (error); 1599} 1600#endif /* COMPAT_43 */ 1601 1602#ifndef _SYS_SYSPROTO_H_ 1603struct sigaltstack_args { 1604 stack_t *ss; 1605 stack_t *oss; 1606}; 1607#endif 1608/* ARGSUSED */ 1609int 1610sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1611{ 1612 stack_t ss, oss; 1613 int error; 1614 1615 if (uap->ss != NULL) { 1616 error = copyin(uap->ss, &ss, sizeof(ss)); 1617 if (error) 1618 return (error); 1619 } 1620 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1621 (uap->oss != NULL) ? &oss : NULL); 1622 if (error) 1623 return (error); 1624 if (uap->oss != NULL) 1625 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1626 return (error); 1627} 1628 1629int 1630kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1631{ 1632 struct proc *p = td->td_proc; 1633 int oonstack; 1634 1635 oonstack = sigonstack(cpu_getstack(td)); 1636 1637 if (oss != NULL) { 1638 *oss = td->td_sigstk; 1639 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1640 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1641 } 1642 1643 if (ss != NULL) { 1644 if (oonstack) 1645 return (EPERM); 1646 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1647 return (EINVAL); 1648 if (!(ss->ss_flags & SS_DISABLE)) { 1649 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1650 return (ENOMEM); 1651 1652 td->td_sigstk = *ss; 1653 td->td_pflags |= TDP_ALTSTACK; 1654 } else { 1655 td->td_pflags &= ~TDP_ALTSTACK; 1656 } 1657 } 1658 return (0); 1659} 1660 1661/* 1662 * Common code for kill process group/broadcast kill. 1663 * cp is calling process. 1664 */ 1665static int 1666killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1667{ 1668 struct proc *p; 1669 struct pgrp *pgrp; 1670 int err; 1671 int ret; 1672 1673 ret = ESRCH; 1674 if (all) { 1675 /* 1676 * broadcast 1677 */ 1678 sx_slock(&allproc_lock); 1679 FOREACH_PROC_IN_SYSTEM(p) { 1680 PROC_LOCK(p); 1681 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1682 p == td->td_proc || p->p_state == PRS_NEW) { 1683 PROC_UNLOCK(p); 1684 continue; 1685 } 1686 err = p_cansignal(td, p, sig); 1687 if (err == 0) { 1688 if (sig) 1689 pksignal(p, sig, ksi); 1690 ret = err; 1691 } 1692 else if (ret == ESRCH) 1693 ret = err; 1694 PROC_UNLOCK(p); 1695 } 1696 sx_sunlock(&allproc_lock); 1697 } else { 1698 sx_slock(&proctree_lock); 1699 if (pgid == 0) { 1700 /* 1701 * zero pgid means send to my process group. 1702 */ 1703 pgrp = td->td_proc->p_pgrp; 1704 PGRP_LOCK(pgrp); 1705 } else { 1706 pgrp = pgfind(pgid); 1707 if (pgrp == NULL) { 1708 sx_sunlock(&proctree_lock); 1709 return (ESRCH); 1710 } 1711 } 1712 sx_sunlock(&proctree_lock); 1713 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1714 PROC_LOCK(p); 1715 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1716 p->p_state == PRS_NEW) { 1717 PROC_UNLOCK(p); 1718 continue; 1719 } 1720 err = p_cansignal(td, p, sig); 1721 if (err == 0) { 1722 if (sig) 1723 pksignal(p, sig, ksi); 1724 ret = err; 1725 } 1726 else if (ret == ESRCH) 1727 ret = err; 1728 PROC_UNLOCK(p); 1729 } 1730 PGRP_UNLOCK(pgrp); 1731 } 1732 return (ret); 1733} 1734 1735#ifndef _SYS_SYSPROTO_H_ 1736struct kill_args { 1737 int pid; 1738 int signum; 1739}; 1740#endif 1741/* ARGSUSED */ 1742int 1743sys_kill(struct thread *td, struct kill_args *uap) 1744{ 1745 ksiginfo_t ksi; 1746 struct proc *p; 1747 int error; 1748 1749 /* 1750 * A process in capability mode can send signals only to himself. 1751 * The main rationale behind this is that abort(3) is implemented as 1752 * kill(getpid(), SIGABRT). 1753 */ 1754 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1755 return (ECAPMODE); 1756 1757 AUDIT_ARG_SIGNUM(uap->signum); 1758 AUDIT_ARG_PID(uap->pid); 1759 if ((u_int)uap->signum > _SIG_MAXSIG) 1760 return (EINVAL); 1761 1762 ksiginfo_init(&ksi); 1763 ksi.ksi_signo = uap->signum; 1764 ksi.ksi_code = SI_USER; 1765 ksi.ksi_pid = td->td_proc->p_pid; 1766 ksi.ksi_uid = td->td_ucred->cr_ruid; 1767 1768 if (uap->pid > 0) { 1769 /* kill single process */ 1770 if ((p = pfind(uap->pid)) == NULL) { 1771 if ((p = zpfind(uap->pid)) == NULL) 1772 return (ESRCH); 1773 } 1774 AUDIT_ARG_PROCESS(p); 1775 error = p_cansignal(td, p, uap->signum); 1776 if (error == 0 && uap->signum) 1777 pksignal(p, uap->signum, &ksi); 1778 PROC_UNLOCK(p); 1779 return (error); 1780 } 1781 switch (uap->pid) { 1782 case -1: /* broadcast signal */ 1783 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1784 case 0: /* signal own process group */ 1785 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1786 default: /* negative explicit process group */ 1787 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1788 } 1789 /* NOTREACHED */ 1790} 1791 1792int 1793sys_pdkill(struct thread *td, struct pdkill_args *uap) 1794{ 1795 struct proc *p; 1796 cap_rights_t rights; 1797 int error; 1798 1799 AUDIT_ARG_SIGNUM(uap->signum); 1800 AUDIT_ARG_FD(uap->fd); 1801 if ((u_int)uap->signum > _SIG_MAXSIG) 1802 return (EINVAL); 1803 1804 error = procdesc_find(td, uap->fd, 1805 cap_rights_init(&rights, CAP_PDKILL), &p); 1806 if (error) 1807 return (error); 1808 AUDIT_ARG_PROCESS(p); 1809 error = p_cansignal(td, p, uap->signum); 1810 if (error == 0 && uap->signum) 1811 kern_psignal(p, uap->signum); 1812 PROC_UNLOCK(p); 1813 return (error); 1814} 1815 1816#if defined(COMPAT_43) 1817#ifndef _SYS_SYSPROTO_H_ 1818struct okillpg_args { 1819 int pgid; 1820 int signum; 1821}; 1822#endif 1823/* ARGSUSED */ 1824int 1825okillpg(struct thread *td, struct okillpg_args *uap) 1826{ 1827 ksiginfo_t ksi; 1828 1829 AUDIT_ARG_SIGNUM(uap->signum); 1830 AUDIT_ARG_PID(uap->pgid); 1831 if ((u_int)uap->signum > _SIG_MAXSIG) 1832 return (EINVAL); 1833 1834 ksiginfo_init(&ksi); 1835 ksi.ksi_signo = uap->signum; 1836 ksi.ksi_code = SI_USER; 1837 ksi.ksi_pid = td->td_proc->p_pid; 1838 ksi.ksi_uid = td->td_ucred->cr_ruid; 1839 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1840} 1841#endif /* COMPAT_43 */ 1842 1843#ifndef _SYS_SYSPROTO_H_ 1844struct sigqueue_args { 1845 pid_t pid; 1846 int signum; 1847 /* union sigval */ void *value; 1848}; 1849#endif 1850int 1851sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1852{ 1853 union sigval sv; 1854 1855 sv.sival_ptr = uap->value; 1856 1857 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1858} 1859 1860int 1861kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1862{ 1863 ksiginfo_t ksi; 1864 struct proc *p; 1865 int error; 1866 1867 if ((u_int)signum > _SIG_MAXSIG) 1868 return (EINVAL); 1869 1870 /* 1871 * Specification says sigqueue can only send signal to 1872 * single process. 1873 */ 1874 if (pid <= 0) 1875 return (EINVAL); 1876 1877 if ((p = pfind(pid)) == NULL) { 1878 if ((p = zpfind(pid)) == NULL) 1879 return (ESRCH); 1880 } 1881 error = p_cansignal(td, p, signum); 1882 if (error == 0 && signum != 0) { 1883 ksiginfo_init(&ksi); 1884 ksi.ksi_flags = KSI_SIGQ; 1885 ksi.ksi_signo = signum; 1886 ksi.ksi_code = SI_QUEUE; 1887 ksi.ksi_pid = td->td_proc->p_pid; 1888 ksi.ksi_uid = td->td_ucred->cr_ruid; 1889 ksi.ksi_value = *value; 1890 error = pksignal(p, ksi.ksi_signo, &ksi); 1891 } 1892 PROC_UNLOCK(p); 1893 return (error); 1894} 1895 1896/* 1897 * Send a signal to a process group. 1898 */ 1899void 1900gsignal(int pgid, int sig, ksiginfo_t *ksi) 1901{ 1902 struct pgrp *pgrp; 1903 1904 if (pgid != 0) { 1905 sx_slock(&proctree_lock); 1906 pgrp = pgfind(pgid); 1907 sx_sunlock(&proctree_lock); 1908 if (pgrp != NULL) { 1909 pgsignal(pgrp, sig, 0, ksi); 1910 PGRP_UNLOCK(pgrp); 1911 } 1912 } 1913} 1914 1915/* 1916 * Send a signal to a process group. If checktty is 1, 1917 * limit to members which have a controlling terminal. 1918 */ 1919void 1920pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1921{ 1922 struct proc *p; 1923 1924 if (pgrp) { 1925 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1926 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1927 PROC_LOCK(p); 1928 if (p->p_state == PRS_NORMAL && 1929 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1930 pksignal(p, sig, ksi); 1931 PROC_UNLOCK(p); 1932 } 1933 } 1934} 1935 1936 1937/* 1938 * Recalculate the signal mask and reset the signal disposition after 1939 * usermode frame for delivery is formed. Should be called after 1940 * mach-specific routine, because sysent->sv_sendsig() needs correct 1941 * ps_siginfo and signal mask. 1942 */ 1943static void 1944postsig_done(int sig, struct thread *td, struct sigacts *ps) 1945{ 1946 sigset_t mask; 1947 1948 mtx_assert(&ps->ps_mtx, MA_OWNED); 1949 td->td_ru.ru_nsignals++; 1950 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1951 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1952 SIGADDSET(mask, sig); 1953 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1954 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1955 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1956 sigdflt(ps, sig); 1957} 1958 1959 1960/* 1961 * Send a signal caused by a trap to the current thread. If it will be 1962 * caught immediately, deliver it with correct code. Otherwise, post it 1963 * normally. 1964 */ 1965void 1966trapsignal(struct thread *td, ksiginfo_t *ksi) 1967{ 1968 struct sigacts *ps; 1969 struct proc *p; 1970 int sig; 1971 int code; 1972 1973 p = td->td_proc; 1974 sig = ksi->ksi_signo; 1975 code = ksi->ksi_code; 1976 KASSERT(_SIG_VALID(sig), ("invalid signal")); 1977 1978 PROC_LOCK(p); 1979 ps = p->p_sigacts; 1980 mtx_lock(&ps->ps_mtx); 1981 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 1982 !SIGISMEMBER(td->td_sigmask, sig)) { 1983#ifdef KTRACE 1984 if (KTRPOINT(curthread, KTR_PSIG)) 1985 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 1986 &td->td_sigmask, code); 1987#endif 1988 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 1989 ksi, &td->td_sigmask); 1990 postsig_done(sig, td, ps); 1991 mtx_unlock(&ps->ps_mtx); 1992 } else { 1993 /* 1994 * Avoid a possible infinite loop if the thread 1995 * masking the signal or process is ignoring the 1996 * signal. 1997 */ 1998 if (kern_forcesigexit && 1999 (SIGISMEMBER(td->td_sigmask, sig) || 2000 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2001 SIGDELSET(td->td_sigmask, sig); 2002 SIGDELSET(ps->ps_sigcatch, sig); 2003 SIGDELSET(ps->ps_sigignore, sig); 2004 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2005 } 2006 mtx_unlock(&ps->ps_mtx); 2007 p->p_code = code; /* XXX for core dump/debugger */ 2008 p->p_sig = sig; /* XXX to verify code */ 2009 tdsendsignal(p, td, sig, ksi); 2010 } 2011 PROC_UNLOCK(p); 2012} 2013 2014static struct thread * 2015sigtd(struct proc *p, int sig, int prop) 2016{ 2017 struct thread *td, *signal_td; 2018 2019 PROC_LOCK_ASSERT(p, MA_OWNED); 2020 2021 /* 2022 * Check if current thread can handle the signal without 2023 * switching context to another thread. 2024 */ 2025 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2026 return (curthread); 2027 signal_td = NULL; 2028 FOREACH_THREAD_IN_PROC(p, td) { 2029 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2030 signal_td = td; 2031 break; 2032 } 2033 } 2034 if (signal_td == NULL) 2035 signal_td = FIRST_THREAD_IN_PROC(p); 2036 return (signal_td); 2037} 2038 2039/* 2040 * Send the signal to the process. If the signal has an action, the action 2041 * is usually performed by the target process rather than the caller; we add 2042 * the signal to the set of pending signals for the process. 2043 * 2044 * Exceptions: 2045 * o When a stop signal is sent to a sleeping process that takes the 2046 * default action, the process is stopped without awakening it. 2047 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2048 * regardless of the signal action (eg, blocked or ignored). 2049 * 2050 * Other ignored signals are discarded immediately. 2051 * 2052 * NB: This function may be entered from the debugger via the "kill" DDB 2053 * command. There is little that can be done to mitigate the possibly messy 2054 * side effects of this unwise possibility. 2055 */ 2056void 2057kern_psignal(struct proc *p, int sig) 2058{ 2059 ksiginfo_t ksi; 2060 2061 ksiginfo_init(&ksi); 2062 ksi.ksi_signo = sig; 2063 ksi.ksi_code = SI_KERNEL; 2064 (void) tdsendsignal(p, NULL, sig, &ksi); 2065} 2066 2067int 2068pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2069{ 2070 2071 return (tdsendsignal(p, NULL, sig, ksi)); 2072} 2073 2074/* Utility function for finding a thread to send signal event to. */ 2075int 2076sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2077{ 2078 struct thread *td; 2079 2080 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2081 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2082 if (td == NULL) 2083 return (ESRCH); 2084 *ttd = td; 2085 } else { 2086 *ttd = NULL; 2087 PROC_LOCK(p); 2088 } 2089 return (0); 2090} 2091 2092void 2093tdsignal(struct thread *td, int sig) 2094{ 2095 ksiginfo_t ksi; 2096 2097 ksiginfo_init(&ksi); 2098 ksi.ksi_signo = sig; 2099 ksi.ksi_code = SI_KERNEL; 2100 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2101} 2102 2103void 2104tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2105{ 2106 2107 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2108} 2109 2110int 2111tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2112{ 2113 sig_t action; 2114 sigqueue_t *sigqueue; 2115 int prop; 2116 struct sigacts *ps; 2117 int intrval; 2118 int ret = 0; 2119 int wakeup_swapper; 2120 2121 MPASS(td == NULL || p == td->td_proc); 2122 PROC_LOCK_ASSERT(p, MA_OWNED); 2123 2124 if (!_SIG_VALID(sig)) 2125 panic("%s(): invalid signal %d", __func__, sig); 2126 2127 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2128 2129 /* 2130 * IEEE Std 1003.1-2001: return success when killing a zombie. 2131 */ 2132 if (p->p_state == PRS_ZOMBIE) { 2133 if (ksi && (ksi->ksi_flags & KSI_INS)) 2134 ksiginfo_tryfree(ksi); 2135 return (ret); 2136 } 2137 2138 ps = p->p_sigacts; 2139 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2140 prop = sigprop(sig); 2141 2142 if (td == NULL) { 2143 td = sigtd(p, sig, prop); 2144 sigqueue = &p->p_sigqueue; 2145 } else 2146 sigqueue = &td->td_sigqueue; 2147 2148 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2149 2150 /* 2151 * If the signal is being ignored, 2152 * then we forget about it immediately. 2153 * (Note: we don't set SIGCONT in ps_sigignore, 2154 * and if it is set to SIG_IGN, 2155 * action will be SIG_DFL here.) 2156 */ 2157 mtx_lock(&ps->ps_mtx); 2158 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2159 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2160 2161 mtx_unlock(&ps->ps_mtx); 2162 if (ksi && (ksi->ksi_flags & KSI_INS)) 2163 ksiginfo_tryfree(ksi); 2164 return (ret); 2165 } 2166 if (SIGISMEMBER(td->td_sigmask, sig)) 2167 action = SIG_HOLD; 2168 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2169 action = SIG_CATCH; 2170 else 2171 action = SIG_DFL; 2172 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2173 intrval = EINTR; 2174 else 2175 intrval = ERESTART; 2176 mtx_unlock(&ps->ps_mtx); 2177 2178 if (prop & SA_CONT) 2179 sigqueue_delete_stopmask_proc(p); 2180 else if (prop & SA_STOP) { 2181 /* 2182 * If sending a tty stop signal to a member of an orphaned 2183 * process group, discard the signal here if the action 2184 * is default; don't stop the process below if sleeping, 2185 * and don't clear any pending SIGCONT. 2186 */ 2187 if ((prop & SA_TTYSTOP) && 2188 (p->p_pgrp->pg_jobc == 0) && 2189 (action == SIG_DFL)) { 2190 if (ksi && (ksi->ksi_flags & KSI_INS)) 2191 ksiginfo_tryfree(ksi); 2192 return (ret); 2193 } 2194 sigqueue_delete_proc(p, SIGCONT); 2195 if (p->p_flag & P_CONTINUED) { 2196 p->p_flag &= ~P_CONTINUED; 2197 PROC_LOCK(p->p_pptr); 2198 sigqueue_take(p->p_ksi); 2199 PROC_UNLOCK(p->p_pptr); 2200 } 2201 } 2202 2203 ret = sigqueue_add(sigqueue, sig, ksi); 2204 if (ret != 0) 2205 return (ret); 2206 signotify(td); 2207 /* 2208 * Defer further processing for signals which are held, 2209 * except that stopped processes must be continued by SIGCONT. 2210 */ 2211 if (action == SIG_HOLD && 2212 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2213 return (ret); 2214 2215 /* SIGKILL: Remove procfs STOPEVENTs. */ 2216 if (sig == SIGKILL) { 2217 /* from procfs_ioctl.c: PIOCBIC */ 2218 p->p_stops = 0; 2219 /* from procfs_ioctl.c: PIOCCONT */ 2220 p->p_step = 0; 2221 wakeup(&p->p_step); 2222 } 2223 /* 2224 * Some signals have a process-wide effect and a per-thread 2225 * component. Most processing occurs when the process next 2226 * tries to cross the user boundary, however there are some 2227 * times when processing needs to be done immediately, such as 2228 * waking up threads so that they can cross the user boundary. 2229 * We try to do the per-process part here. 2230 */ 2231 if (P_SHOULDSTOP(p)) { 2232 KASSERT(!(p->p_flag & P_WEXIT), 2233 ("signal to stopped but exiting process")); 2234 if (sig == SIGKILL) { 2235 /* 2236 * If traced process is already stopped, 2237 * then no further action is necessary. 2238 */ 2239 if (p->p_flag & P_TRACED) 2240 goto out; 2241 /* 2242 * SIGKILL sets process running. 2243 * It will die elsewhere. 2244 * All threads must be restarted. 2245 */ 2246 p->p_flag &= ~P_STOPPED_SIG; 2247 goto runfast; 2248 } 2249 2250 if (prop & SA_CONT) { 2251 /* 2252 * If traced process is already stopped, 2253 * then no further action is necessary. 2254 */ 2255 if (p->p_flag & P_TRACED) 2256 goto out; 2257 /* 2258 * If SIGCONT is default (or ignored), we continue the 2259 * process but don't leave the signal in sigqueue as 2260 * it has no further action. If SIGCONT is held, we 2261 * continue the process and leave the signal in 2262 * sigqueue. If the process catches SIGCONT, let it 2263 * handle the signal itself. If it isn't waiting on 2264 * an event, it goes back to run state. 2265 * Otherwise, process goes back to sleep state. 2266 */ 2267 p->p_flag &= ~P_STOPPED_SIG; 2268 PROC_SLOCK(p); 2269 if (p->p_numthreads == p->p_suspcount) { 2270 PROC_SUNLOCK(p); 2271 p->p_flag |= P_CONTINUED; 2272 p->p_xsig = SIGCONT; 2273 PROC_LOCK(p->p_pptr); 2274 childproc_continued(p); 2275 PROC_UNLOCK(p->p_pptr); 2276 PROC_SLOCK(p); 2277 } 2278 if (action == SIG_DFL) { 2279 thread_unsuspend(p); 2280 PROC_SUNLOCK(p); 2281 sigqueue_delete(sigqueue, sig); 2282 goto out; 2283 } 2284 if (action == SIG_CATCH) { 2285 /* 2286 * The process wants to catch it so it needs 2287 * to run at least one thread, but which one? 2288 */ 2289 PROC_SUNLOCK(p); 2290 goto runfast; 2291 } 2292 /* 2293 * The signal is not ignored or caught. 2294 */ 2295 thread_unsuspend(p); 2296 PROC_SUNLOCK(p); 2297 goto out; 2298 } 2299 2300 if (prop & SA_STOP) { 2301 /* 2302 * If traced process is already stopped, 2303 * then no further action is necessary. 2304 */ 2305 if (p->p_flag & P_TRACED) 2306 goto out; 2307 /* 2308 * Already stopped, don't need to stop again 2309 * (If we did the shell could get confused). 2310 * Just make sure the signal STOP bit set. 2311 */ 2312 p->p_flag |= P_STOPPED_SIG; 2313 sigqueue_delete(sigqueue, sig); 2314 goto out; 2315 } 2316 2317 /* 2318 * All other kinds of signals: 2319 * If a thread is sleeping interruptibly, simulate a 2320 * wakeup so that when it is continued it will be made 2321 * runnable and can look at the signal. However, don't make 2322 * the PROCESS runnable, leave it stopped. 2323 * It may run a bit until it hits a thread_suspend_check(). 2324 */ 2325 wakeup_swapper = 0; 2326 PROC_SLOCK(p); 2327 thread_lock(td); 2328 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2329 wakeup_swapper = sleepq_abort(td, intrval); 2330 thread_unlock(td); 2331 PROC_SUNLOCK(p); 2332 if (wakeup_swapper) 2333 kick_proc0(); 2334 goto out; 2335 /* 2336 * Mutexes are short lived. Threads waiting on them will 2337 * hit thread_suspend_check() soon. 2338 */ 2339 } else if (p->p_state == PRS_NORMAL) { 2340 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2341 tdsigwakeup(td, sig, action, intrval); 2342 goto out; 2343 } 2344 2345 MPASS(action == SIG_DFL); 2346 2347 if (prop & SA_STOP) { 2348 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2349 goto out; 2350 p->p_flag |= P_STOPPED_SIG; 2351 p->p_xsig = sig; 2352 PROC_SLOCK(p); 2353 wakeup_swapper = sig_suspend_threads(td, p, 1); 2354 if (p->p_numthreads == p->p_suspcount) { 2355 /* 2356 * only thread sending signal to another 2357 * process can reach here, if thread is sending 2358 * signal to its process, because thread does 2359 * not suspend itself here, p_numthreads 2360 * should never be equal to p_suspcount. 2361 */ 2362 thread_stopped(p); 2363 PROC_SUNLOCK(p); 2364 sigqueue_delete_proc(p, p->p_xsig); 2365 } else 2366 PROC_SUNLOCK(p); 2367 if (wakeup_swapper) 2368 kick_proc0(); 2369 goto out; 2370 } 2371 } else { 2372 /* Not in "NORMAL" state. discard the signal. */ 2373 sigqueue_delete(sigqueue, sig); 2374 goto out; 2375 } 2376 2377 /* 2378 * The process is not stopped so we need to apply the signal to all the 2379 * running threads. 2380 */ 2381runfast: 2382 tdsigwakeup(td, sig, action, intrval); 2383 PROC_SLOCK(p); 2384 thread_unsuspend(p); 2385 PROC_SUNLOCK(p); 2386out: 2387 /* If we jump here, proc slock should not be owned. */ 2388 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2389 return (ret); 2390} 2391 2392/* 2393 * The force of a signal has been directed against a single 2394 * thread. We need to see what we can do about knocking it 2395 * out of any sleep it may be in etc. 2396 */ 2397static void 2398tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2399{ 2400 struct proc *p = td->td_proc; 2401 int prop; 2402 int wakeup_swapper; 2403 2404 wakeup_swapper = 0; 2405 PROC_LOCK_ASSERT(p, MA_OWNED); 2406 prop = sigprop(sig); 2407 2408 PROC_SLOCK(p); 2409 thread_lock(td); 2410 /* 2411 * Bring the priority of a thread up if we want it to get 2412 * killed in this lifetime. Be careful to avoid bumping the 2413 * priority of the idle thread, since we still allow to signal 2414 * kernel processes. 2415 */ 2416 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2417 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2418 sched_prio(td, PUSER); 2419 if (TD_ON_SLEEPQ(td)) { 2420 /* 2421 * If thread is sleeping uninterruptibly 2422 * we can't interrupt the sleep... the signal will 2423 * be noticed when the process returns through 2424 * trap() or syscall(). 2425 */ 2426 if ((td->td_flags & TDF_SINTR) == 0) 2427 goto out; 2428 /* 2429 * If SIGCONT is default (or ignored) and process is 2430 * asleep, we are finished; the process should not 2431 * be awakened. 2432 */ 2433 if ((prop & SA_CONT) && action == SIG_DFL) { 2434 thread_unlock(td); 2435 PROC_SUNLOCK(p); 2436 sigqueue_delete(&p->p_sigqueue, sig); 2437 /* 2438 * It may be on either list in this state. 2439 * Remove from both for now. 2440 */ 2441 sigqueue_delete(&td->td_sigqueue, sig); 2442 return; 2443 } 2444 2445 /* 2446 * Don't awaken a sleeping thread for SIGSTOP if the 2447 * STOP signal is deferred. 2448 */ 2449 if ((prop & SA_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2450 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2451 goto out; 2452 2453 /* 2454 * Give low priority threads a better chance to run. 2455 */ 2456 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2457 sched_prio(td, PUSER); 2458 2459 wakeup_swapper = sleepq_abort(td, intrval); 2460 } else { 2461 /* 2462 * Other states do nothing with the signal immediately, 2463 * other than kicking ourselves if we are running. 2464 * It will either never be noticed, or noticed very soon. 2465 */ 2466#ifdef SMP 2467 if (TD_IS_RUNNING(td) && td != curthread) 2468 forward_signal(td); 2469#endif 2470 } 2471out: 2472 PROC_SUNLOCK(p); 2473 thread_unlock(td); 2474 if (wakeup_swapper) 2475 kick_proc0(); 2476} 2477 2478static int 2479sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2480{ 2481 struct thread *td2; 2482 int wakeup_swapper; 2483 2484 PROC_LOCK_ASSERT(p, MA_OWNED); 2485 PROC_SLOCK_ASSERT(p, MA_OWNED); 2486 MPASS(sending || td == curthread); 2487 2488 wakeup_swapper = 0; 2489 FOREACH_THREAD_IN_PROC(p, td2) { 2490 thread_lock(td2); 2491 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2492 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2493 (td2->td_flags & TDF_SINTR)) { 2494 if (td2->td_flags & TDF_SBDRY) { 2495 /* 2496 * Once a thread is asleep with 2497 * TDF_SBDRY and without TDF_SERESTART 2498 * or TDF_SEINTR set, it should never 2499 * become suspended due to this check. 2500 */ 2501 KASSERT(!TD_IS_SUSPENDED(td2), 2502 ("thread with deferred stops suspended")); 2503 if (TD_SBDRY_INTR(td2)) 2504 wakeup_swapper |= sleepq_abort(td2, 2505 TD_SBDRY_ERRNO(td2)); 2506 } else if (!TD_IS_SUSPENDED(td2)) { 2507 thread_suspend_one(td2); 2508 } 2509 } else if (!TD_IS_SUSPENDED(td2)) { 2510 if (sending || td != td2) 2511 td2->td_flags |= TDF_ASTPENDING; 2512#ifdef SMP 2513 if (TD_IS_RUNNING(td2) && td2 != td) 2514 forward_signal(td2); 2515#endif 2516 } 2517 thread_unlock(td2); 2518 } 2519 return (wakeup_swapper); 2520} 2521 2522/* 2523 * Stop the process for an event deemed interesting to the debugger. If si is 2524 * non-NULL, this is a signal exchange; the new signal requested by the 2525 * debugger will be returned for handling. If si is NULL, this is some other 2526 * type of interesting event. The debugger may request a signal be delivered in 2527 * that case as well, however it will be deferred until it can be handled. 2528 */ 2529int 2530ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2531{ 2532 struct proc *p = td->td_proc; 2533 struct thread *td2; 2534 ksiginfo_t ksi; 2535 int prop; 2536 2537 PROC_LOCK_ASSERT(p, MA_OWNED); 2538 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2539 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2540 &p->p_mtx.lock_object, "Stopping for traced signal"); 2541 2542 td->td_xsig = sig; 2543 2544 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2545 td->td_dbgflags |= TDB_XSIG; 2546 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2547 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2548 PROC_SLOCK(p); 2549 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2550 if (P_KILLED(p)) { 2551 /* 2552 * Ensure that, if we've been PT_KILLed, the 2553 * exit status reflects that. Another thread 2554 * may also be in ptracestop(), having just 2555 * received the SIGKILL, but this thread was 2556 * unsuspended first. 2557 */ 2558 td->td_dbgflags &= ~TDB_XSIG; 2559 td->td_xsig = SIGKILL; 2560 p->p_ptevents = 0; 2561 break; 2562 } 2563 if (p->p_flag & P_SINGLE_EXIT && 2564 !(td->td_dbgflags & TDB_EXIT)) { 2565 /* 2566 * Ignore ptrace stops except for thread exit 2567 * events when the process exits. 2568 */ 2569 td->td_dbgflags &= ~TDB_XSIG; 2570 PROC_SUNLOCK(p); 2571 return (0); 2572 } 2573 2574 /* 2575 * Make wait(2) work. Ensure that right after the 2576 * attach, the thread which was decided to become the 2577 * leader of attach gets reported to the waiter. 2578 * Otherwise, just avoid overwriting another thread's 2579 * assignment to p_xthread. If another thread has 2580 * already set p_xthread, the current thread will get 2581 * a chance to report itself upon the next iteration. 2582 */ 2583 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2584 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2585 p->p_xthread == NULL)) { 2586 p->p_xsig = sig; 2587 p->p_xthread = td; 2588 td->td_dbgflags &= ~TDB_FSTP; 2589 p->p_flag2 &= ~P2_PTRACE_FSTP; 2590 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2591 sig_suspend_threads(td, p, 0); 2592 } 2593 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2594 td->td_dbgflags &= ~TDB_STOPATFORK; 2595 cv_broadcast(&p->p_dbgwait); 2596 } 2597stopme: 2598 thread_suspend_switch(td, p); 2599 if (p->p_xthread == td) 2600 p->p_xthread = NULL; 2601 if (!(p->p_flag & P_TRACED)) 2602 break; 2603 if (td->td_dbgflags & TDB_SUSPEND) { 2604 if (p->p_flag & P_SINGLE_EXIT) 2605 break; 2606 goto stopme; 2607 } 2608 } 2609 PROC_SUNLOCK(p); 2610 } 2611 2612 if (si != NULL && sig == td->td_xsig) { 2613 /* Parent wants us to take the original signal unchanged. */ 2614 si->ksi_flags |= KSI_HEAD; 2615 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2616 si->ksi_signo = 0; 2617 } else if (td->td_xsig != 0) { 2618 /* 2619 * If parent wants us to take a new signal, then it will leave 2620 * it in td->td_xsig; otherwise we just look for signals again. 2621 */ 2622 ksiginfo_init(&ksi); 2623 ksi.ksi_signo = td->td_xsig; 2624 ksi.ksi_flags |= KSI_PTRACE; 2625 prop = sigprop(td->td_xsig); 2626 td2 = sigtd(p, td->td_xsig, prop); 2627 tdsendsignal(p, td2, td->td_xsig, &ksi); 2628 if (td != td2) 2629 return (0); 2630 } 2631 2632 return (td->td_xsig); 2633} 2634 2635static void 2636reschedule_signals(struct proc *p, sigset_t block, int flags) 2637{ 2638 struct sigacts *ps; 2639 struct thread *td; 2640 int sig; 2641 2642 PROC_LOCK_ASSERT(p, MA_OWNED); 2643 ps = p->p_sigacts; 2644 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2645 MA_OWNED : MA_NOTOWNED); 2646 if (SIGISEMPTY(p->p_siglist)) 2647 return; 2648 SIGSETAND(block, p->p_siglist); 2649 while ((sig = sig_ffs(&block)) != 0) { 2650 SIGDELSET(block, sig); 2651 td = sigtd(p, sig, 0); 2652 signotify(td); 2653 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2654 mtx_lock(&ps->ps_mtx); 2655 if (p->p_flag & P_TRACED || 2656 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2657 !SIGISMEMBER(td->td_sigmask, sig))) 2658 tdsigwakeup(td, sig, SIG_CATCH, 2659 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2660 ERESTART)); 2661 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2662 mtx_unlock(&ps->ps_mtx); 2663 } 2664} 2665 2666void 2667tdsigcleanup(struct thread *td) 2668{ 2669 struct proc *p; 2670 sigset_t unblocked; 2671 2672 p = td->td_proc; 2673 PROC_LOCK_ASSERT(p, MA_OWNED); 2674 2675 sigqueue_flush(&td->td_sigqueue); 2676 if (p->p_numthreads == 1) 2677 return; 2678 2679 /* 2680 * Since we cannot handle signals, notify signal post code 2681 * about this by filling the sigmask. 2682 * 2683 * Also, if needed, wake up thread(s) that do not block the 2684 * same signals as the exiting thread, since the thread might 2685 * have been selected for delivery and woken up. 2686 */ 2687 SIGFILLSET(unblocked); 2688 SIGSETNAND(unblocked, td->td_sigmask); 2689 SIGFILLSET(td->td_sigmask); 2690 reschedule_signals(p, unblocked, 0); 2691 2692} 2693 2694static int 2695sigdeferstop_curr_flags(int cflags) 2696{ 2697 2698 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2699 (cflags & TDF_SBDRY) != 0); 2700 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2701} 2702 2703/* 2704 * Defer the delivery of SIGSTOP for the current thread, according to 2705 * the requested mode. Returns previous flags, which must be restored 2706 * by sigallowstop(). 2707 * 2708 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2709 * cleared by the current thread, which allow the lock-less read-only 2710 * accesses below. 2711 */ 2712int 2713sigdeferstop_impl(int mode) 2714{ 2715 struct thread *td; 2716 int cflags, nflags; 2717 2718 td = curthread; 2719 cflags = sigdeferstop_curr_flags(td->td_flags); 2720 switch (mode) { 2721 case SIGDEFERSTOP_NOP: 2722 nflags = cflags; 2723 break; 2724 case SIGDEFERSTOP_OFF: 2725 nflags = 0; 2726 break; 2727 case SIGDEFERSTOP_SILENT: 2728 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2729 break; 2730 case SIGDEFERSTOP_EINTR: 2731 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2732 break; 2733 case SIGDEFERSTOP_ERESTART: 2734 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2735 break; 2736 default: 2737 panic("sigdeferstop: invalid mode %x", mode); 2738 break; 2739 } 2740 if (cflags == nflags) 2741 return (SIGDEFERSTOP_VAL_NCHG); 2742 thread_lock(td); 2743 td->td_flags = (td->td_flags & ~cflags) | nflags; 2744 thread_unlock(td); 2745 return (cflags); 2746} 2747 2748/* 2749 * Restores the STOP handling mode, typically permitting the delivery 2750 * of SIGSTOP for the current thread. This does not immediately 2751 * suspend if a stop was posted. Instead, the thread will suspend 2752 * either via ast() or a subsequent interruptible sleep. 2753 */ 2754void 2755sigallowstop_impl(int prev) 2756{ 2757 struct thread *td; 2758 int cflags; 2759 2760 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2761 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2762 ("sigallowstop: incorrect previous mode %x", prev)); 2763 td = curthread; 2764 cflags = sigdeferstop_curr_flags(td->td_flags); 2765 if (cflags != prev) { 2766 thread_lock(td); 2767 td->td_flags = (td->td_flags & ~cflags) | prev; 2768 thread_unlock(td); 2769 } 2770} 2771 2772/* 2773 * If the current process has received a signal (should be caught or cause 2774 * termination, should interrupt current syscall), return the signal number. 2775 * Stop signals with default action are processed immediately, then cleared; 2776 * they aren't returned. This is checked after each entry to the system for 2777 * a syscall or trap (though this can usually be done without calling issignal 2778 * by checking the pending signal masks in cursig.) The normal call 2779 * sequence is 2780 * 2781 * while (sig = cursig(curthread)) 2782 * postsig(sig); 2783 */ 2784static int 2785issignal(struct thread *td) 2786{ 2787 struct proc *p; 2788 struct sigacts *ps; 2789 struct sigqueue *queue; 2790 sigset_t sigpending; 2791 int prop, sig, traced; 2792 ksiginfo_t ksi; 2793 2794 p = td->td_proc; 2795 ps = p->p_sigacts; 2796 mtx_assert(&ps->ps_mtx, MA_OWNED); 2797 PROC_LOCK_ASSERT(p, MA_OWNED); 2798 for (;;) { 2799 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2800 2801 sigpending = td->td_sigqueue.sq_signals; 2802 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2803 SIGSETNAND(sigpending, td->td_sigmask); 2804 2805 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2806 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2807 SIG_STOPSIGMASK(sigpending); 2808 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2809 return (0); 2810 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2811 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2812 SIGISMEMBER(sigpending, SIGSTOP)) { 2813 /* 2814 * If debugger just attached, always consume 2815 * SIGSTOP from ptrace(PT_ATTACH) first, to 2816 * execute the debugger attach ritual in 2817 * order. 2818 */ 2819 sig = SIGSTOP; 2820 td->td_dbgflags |= TDB_FSTP; 2821 } else { 2822 sig = sig_ffs(&sigpending); 2823 } 2824 2825 if (p->p_stops & S_SIG) { 2826 mtx_unlock(&ps->ps_mtx); 2827 stopevent(p, S_SIG, sig); 2828 mtx_lock(&ps->ps_mtx); 2829 } 2830 2831 /* 2832 * We should see pending but ignored signals 2833 * only if P_TRACED was on when they were posted. 2834 */ 2835 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2836 sigqueue_delete(&td->td_sigqueue, sig); 2837 sigqueue_delete(&p->p_sigqueue, sig); 2838 continue; 2839 } 2840 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2841 /* 2842 * If traced, always stop. 2843 * Remove old signal from queue before the stop. 2844 * XXX shrug off debugger, it causes siginfo to 2845 * be thrown away. 2846 */ 2847 queue = &td->td_sigqueue; 2848 ksiginfo_init(&ksi); 2849 if (sigqueue_get(queue, sig, &ksi) == 0) { 2850 queue = &p->p_sigqueue; 2851 sigqueue_get(queue, sig, &ksi); 2852 } 2853 td->td_si = ksi.ksi_info; 2854 2855 mtx_unlock(&ps->ps_mtx); 2856 sig = ptracestop(td, sig, &ksi); 2857 mtx_lock(&ps->ps_mtx); 2858 2859 /* 2860 * Keep looking if the debugger discarded or 2861 * replaced the signal. 2862 */ 2863 if (sig == 0) 2864 continue; 2865 2866 /* 2867 * If the signal became masked, re-queue it. 2868 */ 2869 if (SIGISMEMBER(td->td_sigmask, sig)) { 2870 ksi.ksi_flags |= KSI_HEAD; 2871 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2872 continue; 2873 } 2874 2875 /* 2876 * If the traced bit got turned off, requeue 2877 * the signal and go back up to the top to 2878 * rescan signals. This ensures that p_sig* 2879 * and p_sigact are consistent. 2880 */ 2881 if ((p->p_flag & P_TRACED) == 0) { 2882 ksi.ksi_flags |= KSI_HEAD; 2883 sigqueue_add(queue, sig, &ksi); 2884 continue; 2885 } 2886 } 2887 2888 prop = sigprop(sig); 2889 2890 /* 2891 * Decide whether the signal should be returned. 2892 * Return the signal's number, or fall through 2893 * to clear it from the pending mask. 2894 */ 2895 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2896 2897 case (intptr_t)SIG_DFL: 2898 /* 2899 * Don't take default actions on system processes. 2900 */ 2901 if (p->p_pid <= 1) { 2902#ifdef DIAGNOSTIC 2903 /* 2904 * Are you sure you want to ignore SIGSEGV 2905 * in init? XXX 2906 */ 2907 printf("Process (pid %lu) got signal %d\n", 2908 (u_long)p->p_pid, sig); 2909#endif 2910 break; /* == ignore */ 2911 } 2912 /* 2913 * If there is a pending stop signal to process with 2914 * default action, stop here, then clear the signal. 2915 * Traced or exiting processes should ignore stops. 2916 * Additionally, a member of an orphaned process group 2917 * should ignore tty stops. 2918 */ 2919 if (prop & SA_STOP) { 2920 if (p->p_flag & 2921 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2922 (p->p_pgrp->pg_jobc == 0 && 2923 prop & SA_TTYSTOP)) 2924 break; /* == ignore */ 2925 if (TD_SBDRY_INTR(td)) { 2926 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2927 ("lost TDF_SBDRY")); 2928 return (-1); 2929 } 2930 mtx_unlock(&ps->ps_mtx); 2931 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2932 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2933 sigqueue_delete(&td->td_sigqueue, sig); 2934 sigqueue_delete(&p->p_sigqueue, sig); 2935 p->p_flag |= P_STOPPED_SIG; 2936 p->p_xsig = sig; 2937 PROC_SLOCK(p); 2938 sig_suspend_threads(td, p, 0); 2939 thread_suspend_switch(td, p); 2940 PROC_SUNLOCK(p); 2941 mtx_lock(&ps->ps_mtx); 2942 goto next; 2943 } else if (prop & SA_IGNORE) { 2944 /* 2945 * Except for SIGCONT, shouldn't get here. 2946 * Default action is to ignore; drop it. 2947 */ 2948 break; /* == ignore */ 2949 } else 2950 return (sig); 2951 /*NOTREACHED*/ 2952 2953 case (intptr_t)SIG_IGN: 2954 /* 2955 * Masking above should prevent us ever trying 2956 * to take action on an ignored signal other 2957 * than SIGCONT, unless process is traced. 2958 */ 2959 if ((prop & SA_CONT) == 0 && 2960 (p->p_flag & P_TRACED) == 0) 2961 printf("issignal\n"); 2962 break; /* == ignore */ 2963 2964 default: 2965 /* 2966 * This signal has an action, let 2967 * postsig() process it. 2968 */ 2969 return (sig); 2970 } 2971 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 2972 sigqueue_delete(&p->p_sigqueue, sig); 2973next:; 2974 } 2975 /* NOTREACHED */ 2976} 2977 2978void 2979thread_stopped(struct proc *p) 2980{ 2981 int n; 2982 2983 PROC_LOCK_ASSERT(p, MA_OWNED); 2984 PROC_SLOCK_ASSERT(p, MA_OWNED); 2985 n = p->p_suspcount; 2986 if (p == curproc) 2987 n++; 2988 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 2989 PROC_SUNLOCK(p); 2990 p->p_flag &= ~P_WAITED; 2991 PROC_LOCK(p->p_pptr); 2992 childproc_stopped(p, (p->p_flag & P_TRACED) ? 2993 CLD_TRAPPED : CLD_STOPPED); 2994 PROC_UNLOCK(p->p_pptr); 2995 PROC_SLOCK(p); 2996 } 2997} 2998 2999/* 3000 * Take the action for the specified signal 3001 * from the current set of pending signals. 3002 */ 3003int 3004postsig(int sig) 3005{ 3006 struct thread *td; 3007 struct proc *p; 3008 struct sigacts *ps; 3009 sig_t action; 3010 ksiginfo_t ksi; 3011 sigset_t returnmask; 3012 3013 KASSERT(sig != 0, ("postsig")); 3014 3015 td = curthread; 3016 p = td->td_proc; 3017 PROC_LOCK_ASSERT(p, MA_OWNED); 3018 ps = p->p_sigacts; 3019 mtx_assert(&ps->ps_mtx, MA_OWNED); 3020 ksiginfo_init(&ksi); 3021 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3022 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3023 return (0); 3024 ksi.ksi_signo = sig; 3025 if (ksi.ksi_code == SI_TIMER) 3026 itimer_accept(p, ksi.ksi_timerid, &ksi); 3027 action = ps->ps_sigact[_SIG_IDX(sig)]; 3028#ifdef KTRACE 3029 if (KTRPOINT(td, KTR_PSIG)) 3030 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3031 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3032#endif 3033 if ((p->p_stops & S_SIG) != 0) { 3034 mtx_unlock(&ps->ps_mtx); 3035 stopevent(p, S_SIG, sig); 3036 mtx_lock(&ps->ps_mtx); 3037 } 3038 3039 if (action == SIG_DFL) { 3040 /* 3041 * Default action, where the default is to kill 3042 * the process. (Other cases were ignored above.) 3043 */ 3044 mtx_unlock(&ps->ps_mtx); 3045 proc_td_siginfo_capture(td, &ksi.ksi_info); 3046 sigexit(td, sig); 3047 /* NOTREACHED */ 3048 } else { 3049 /* 3050 * If we get here, the signal must be caught. 3051 */ 3052 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3053 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3054 ("postsig action: blocked sig %d", sig)); 3055 3056 /* 3057 * Set the new mask value and also defer further 3058 * occurrences of this signal. 3059 * 3060 * Special case: user has done a sigsuspend. Here the 3061 * current mask is not of interest, but rather the 3062 * mask from before the sigsuspend is what we want 3063 * restored after the signal processing is completed. 3064 */ 3065 if (td->td_pflags & TDP_OLDMASK) { 3066 returnmask = td->td_oldsigmask; 3067 td->td_pflags &= ~TDP_OLDMASK; 3068 } else 3069 returnmask = td->td_sigmask; 3070 3071 if (p->p_sig == sig) { 3072 p->p_code = 0; 3073 p->p_sig = 0; 3074 } 3075 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3076 postsig_done(sig, td, ps); 3077 } 3078 return (1); 3079} 3080 3081/* 3082 * Kill the current process for stated reason. 3083 */ 3084void 3085killproc(struct proc *p, char *why) 3086{ 3087 3088 PROC_LOCK_ASSERT(p, MA_OWNED); 3089 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3090 p->p_comm); 3091 log(LOG_ERR, "pid %d (%s), uid %d, was killed: %s\n", p->p_pid, 3092 p->p_comm, p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3093 p->p_flag |= P_WKILLED; 3094 kern_psignal(p, SIGKILL); 3095} 3096 3097/* 3098 * Force the current process to exit with the specified signal, dumping core 3099 * if appropriate. We bypass the normal tests for masked and caught signals, 3100 * allowing unrecoverable failures to terminate the process without changing 3101 * signal state. Mark the accounting record with the signal termination. 3102 * If dumping core, save the signal number for the debugger. Calls exit and 3103 * does not return. 3104 */ 3105void 3106sigexit(struct thread *td, int sig) 3107{ 3108 struct proc *p = td->td_proc; 3109 3110 PROC_LOCK_ASSERT(p, MA_OWNED); 3111 p->p_acflag |= AXSIG; 3112 /* 3113 * We must be single-threading to generate a core dump. This 3114 * ensures that the registers in the core file are up-to-date. 3115 * Also, the ELF dump handler assumes that the thread list doesn't 3116 * change out from under it. 3117 * 3118 * XXX If another thread attempts to single-thread before us 3119 * (e.g. via fork()), we won't get a dump at all. 3120 */ 3121 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 3122 p->p_sig = sig; 3123 /* 3124 * Log signals which would cause core dumps 3125 * (Log as LOG_INFO to appease those who don't want 3126 * these messages.) 3127 * XXX : Todo, as well as euid, write out ruid too 3128 * Note that coredump() drops proc lock. 3129 */ 3130 if (coredump(td) == 0) 3131 sig |= WCOREFLAG; 3132 if (kern_logsigexit) 3133 log(LOG_INFO, 3134 "pid %d (%s), uid %d: exited on signal %d%s\n", 3135 p->p_pid, p->p_comm, 3136 td->td_ucred ? td->td_ucred->cr_uid : -1, 3137 sig &~ WCOREFLAG, 3138 sig & WCOREFLAG ? " (core dumped)" : ""); 3139 } else 3140 PROC_UNLOCK(p); 3141 exit1(td, 0, sig); 3142 /* NOTREACHED */ 3143} 3144 3145/* 3146 * Send queued SIGCHLD to parent when child process's state 3147 * is changed. 3148 */ 3149static void 3150sigparent(struct proc *p, int reason, int status) 3151{ 3152 PROC_LOCK_ASSERT(p, MA_OWNED); 3153 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3154 3155 if (p->p_ksi != NULL) { 3156 p->p_ksi->ksi_signo = SIGCHLD; 3157 p->p_ksi->ksi_code = reason; 3158 p->p_ksi->ksi_status = status; 3159 p->p_ksi->ksi_pid = p->p_pid; 3160 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3161 if (KSI_ONQ(p->p_ksi)) 3162 return; 3163 } 3164 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3165} 3166 3167static void 3168childproc_jobstate(struct proc *p, int reason, int sig) 3169{ 3170 struct sigacts *ps; 3171 3172 PROC_LOCK_ASSERT(p, MA_OWNED); 3173 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3174 3175 /* 3176 * Wake up parent sleeping in kern_wait(), also send 3177 * SIGCHLD to parent, but SIGCHLD does not guarantee 3178 * that parent will awake, because parent may masked 3179 * the signal. 3180 */ 3181 p->p_pptr->p_flag |= P_STATCHILD; 3182 wakeup(p->p_pptr); 3183 3184 ps = p->p_pptr->p_sigacts; 3185 mtx_lock(&ps->ps_mtx); 3186 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3187 mtx_unlock(&ps->ps_mtx); 3188 sigparent(p, reason, sig); 3189 } else 3190 mtx_unlock(&ps->ps_mtx); 3191} 3192 3193void 3194childproc_stopped(struct proc *p, int reason) 3195{ 3196 3197 childproc_jobstate(p, reason, p->p_xsig); 3198} 3199 3200void 3201childproc_continued(struct proc *p) 3202{ 3203 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3204} 3205 3206void 3207childproc_exited(struct proc *p) 3208{ 3209 int reason, status; 3210 3211 if (WCOREDUMP(p->p_xsig)) { 3212 reason = CLD_DUMPED; 3213 status = WTERMSIG(p->p_xsig); 3214 } else if (WIFSIGNALED(p->p_xsig)) { 3215 reason = CLD_KILLED; 3216 status = WTERMSIG(p->p_xsig); 3217 } else { 3218 reason = CLD_EXITED; 3219 status = p->p_xexit; 3220 } 3221 /* 3222 * XXX avoid calling wakeup(p->p_pptr), the work is 3223 * done in exit1(). 3224 */ 3225 sigparent(p, reason, status); 3226} 3227 3228/* 3229 * We only have 1 character for the core count in the format 3230 * string, so the range will be 0-9 3231 */ 3232#define MAX_NUM_CORES 10 3233static int num_cores = 5; 3234 3235static int 3236sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3237{ 3238 int error; 3239 int new_val; 3240 3241 new_val = num_cores; 3242 error = sysctl_handle_int(oidp, &new_val, 0, req); 3243 if (error != 0 || req->newptr == NULL) 3244 return (error); 3245 if (new_val > MAX_NUM_CORES) 3246 new_val = MAX_NUM_CORES; 3247 if (new_val < 0) 3248 new_val = 0; 3249 num_cores = new_val; 3250 return (0); 3251} 3252SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3253 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3254 3255#define GZ_SUFFIX ".gz" 3256 3257#ifdef GZIO 3258static int compress_user_cores = 1; 3259SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN, 3260 &compress_user_cores, 0, "Compression of user corefiles"); 3261 3262int compress_user_cores_gzlevel = 6; 3263SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN, 3264 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level"); 3265#else 3266static int compress_user_cores = 0; 3267#endif 3268 3269/* 3270 * Protect the access to corefilename[] by allproc_lock. 3271 */ 3272#define corefilename_lock allproc_lock 3273 3274static char corefilename[MAXPATHLEN] = {"%N.core"}; 3275TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3276 3277static int 3278sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3279{ 3280 int error; 3281 3282 sx_xlock(&corefilename_lock); 3283 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3284 req); 3285 sx_xunlock(&corefilename_lock); 3286 3287 return (error); 3288} 3289SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3290 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3291 "Process corefile name format string"); 3292 3293/* 3294 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3295 * Expand the name described in corefilename, using name, uid, and pid 3296 * and open/create core file. 3297 * corefilename is a printf-like string, with three format specifiers: 3298 * %N name of process ("name") 3299 * %P process id (pid) 3300 * %U user id (uid) 3301 * For example, "%N.core" is the default; they can be disabled completely 3302 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3303 * This is controlled by the sysctl variable kern.corefile (see above). 3304 */ 3305static int 3306corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3307 int compress, struct vnode **vpp, char **namep) 3308{ 3309 struct nameidata nd; 3310 struct sbuf sb; 3311 const char *format; 3312 char *hostname, *name; 3313 int indexpos, i, error, cmode, flags, oflags; 3314 3315 hostname = NULL; 3316 format = corefilename; 3317 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3318 indexpos = -1; 3319 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3320 sx_slock(&corefilename_lock); 3321 for (i = 0; format[i] != '\0'; i++) { 3322 switch (format[i]) { 3323 case '%': /* Format character */ 3324 i++; 3325 switch (format[i]) { 3326 case '%': 3327 sbuf_putc(&sb, '%'); 3328 break; 3329 case 'H': /* hostname */ 3330 if (hostname == NULL) { 3331 hostname = malloc(MAXHOSTNAMELEN, 3332 M_TEMP, M_WAITOK); 3333 } 3334 getcredhostname(td->td_ucred, hostname, 3335 MAXHOSTNAMELEN); 3336 sbuf_printf(&sb, "%s", hostname); 3337 break; 3338 case 'I': /* autoincrementing index */ 3339 sbuf_printf(&sb, "0"); 3340 indexpos = sbuf_len(&sb) - 1; 3341 break; 3342 case 'N': /* process name */ 3343 sbuf_printf(&sb, "%s", comm); 3344 break; 3345 case 'P': /* process id */ 3346 sbuf_printf(&sb, "%u", pid); 3347 break; 3348 case 'U': /* user id */ 3349 sbuf_printf(&sb, "%u", uid); 3350 break; 3351 default: 3352 log(LOG_ERR, 3353 "Unknown format character %c in " 3354 "corename `%s'\n", format[i], format); 3355 break; 3356 } 3357 break; 3358 default: 3359 sbuf_putc(&sb, format[i]); 3360 break; 3361 } 3362 } 3363 sx_sunlock(&corefilename_lock); 3364 free(hostname, M_TEMP); 3365 if (compress) 3366 sbuf_printf(&sb, GZ_SUFFIX); 3367 if (sbuf_error(&sb) != 0) { 3368 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3369 "long\n", (long)pid, comm, (u_long)uid); 3370 sbuf_delete(&sb); 3371 free(name, M_TEMP); 3372 return (ENOMEM); 3373 } 3374 sbuf_finish(&sb); 3375 sbuf_delete(&sb); 3376 3377 cmode = S_IRUSR | S_IWUSR; 3378 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3379 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3380 3381 /* 3382 * If the core format has a %I in it, then we need to check 3383 * for existing corefiles before returning a name. 3384 * To do this we iterate over 0..num_cores to find a 3385 * non-existing core file name to use. 3386 */ 3387 if (indexpos != -1) { 3388 for (i = 0; i < num_cores; i++) { 3389 flags = O_CREAT | O_EXCL | FWRITE | O_NOFOLLOW; 3390 name[indexpos] = '0' + i; 3391 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3392 error = vn_open_cred(&nd, &flags, cmode, oflags, 3393 td->td_ucred, NULL); 3394 if (error) { 3395 if (error == EEXIST) 3396 continue; 3397 log(LOG_ERR, 3398 "pid %d (%s), uid (%u): Path `%s' failed " 3399 "on initial open test, error = %d\n", 3400 pid, comm, uid, name, error); 3401 } 3402 goto out; 3403 } 3404 } 3405 3406 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3407 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3408 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, NULL); 3409out: 3410 if (error) { 3411#ifdef AUDIT 3412 audit_proc_coredump(td, name, error); 3413#endif 3414 free(name, M_TEMP); 3415 return (error); 3416 } 3417 NDFREE(&nd, NDF_ONLY_PNBUF); 3418 *vpp = nd.ni_vp; 3419 *namep = name; 3420 return (0); 3421} 3422 3423static int 3424coredump_sanitise_path(const char *path) 3425{ 3426 size_t i; 3427 3428 /* 3429 * Only send a subset of ASCII to devd(8) because it 3430 * might pass these strings to sh -c. 3431 */ 3432 for (i = 0; path[i]; i++) 3433 if (!(isalpha(path[i]) || isdigit(path[i])) && 3434 path[i] != '/' && path[i] != '.' && 3435 path[i] != '-') 3436 return (0); 3437 3438 return (1); 3439} 3440 3441/* 3442 * Dump a process' core. The main routine does some 3443 * policy checking, and creates the name of the coredump; 3444 * then it passes on a vnode and a size limit to the process-specific 3445 * coredump routine if there is one; if there _is not_ one, it returns 3446 * ENOSYS; otherwise it returns the error from the process-specific routine. 3447 */ 3448 3449static int 3450coredump(struct thread *td) 3451{ 3452 struct proc *p = td->td_proc; 3453 struct ucred *cred = td->td_ucred; 3454 struct vnode *vp; 3455 struct flock lf; 3456 struct vattr vattr; 3457 int error, error1, locked; 3458 char *name; /* name of corefile */ 3459 void *rl_cookie; 3460 off_t limit; 3461 char *data = NULL; 3462 char *fullpath, *freepath = NULL; 3463 size_t len; 3464 static const char comm_name[] = "comm="; 3465 static const char core_name[] = "core="; 3466 3467 PROC_LOCK_ASSERT(p, MA_OWNED); 3468 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3469 _STOPEVENT(p, S_CORE, 0); 3470 3471 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3472 (p->p_flag2 & P2_NOTRACE) != 0) { 3473 PROC_UNLOCK(p); 3474 return (EFAULT); 3475 } 3476 3477 /* 3478 * Note that the bulk of limit checking is done after 3479 * the corefile is created. The exception is if the limit 3480 * for corefiles is 0, in which case we don't bother 3481 * creating the corefile at all. This layout means that 3482 * a corefile is truncated instead of not being created, 3483 * if it is larger than the limit. 3484 */ 3485 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3486 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3487 PROC_UNLOCK(p); 3488 return (EFBIG); 3489 } 3490 PROC_UNLOCK(p); 3491 3492 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3493 compress_user_cores, &vp, &name); 3494 if (error != 0) 3495 return (error); 3496 3497 /* 3498 * Don't dump to non-regular files or files with links. 3499 * Do not dump into system files. 3500 */ 3501 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3502 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0) { 3503 VOP_UNLOCK(vp, 0); 3504 error = EFAULT; 3505 goto out; 3506 } 3507 3508 VOP_UNLOCK(vp, 0); 3509 3510 /* Postpone other writers, including core dumps of other processes. */ 3511 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3512 3513 lf.l_whence = SEEK_SET; 3514 lf.l_start = 0; 3515 lf.l_len = 0; 3516 lf.l_type = F_WRLCK; 3517 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3518 3519 VATTR_NULL(&vattr); 3520 vattr.va_size = 0; 3521 if (set_core_nodump_flag) 3522 vattr.va_flags = UF_NODUMP; 3523 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3524 VOP_SETATTR(vp, &vattr, cred); 3525 VOP_UNLOCK(vp, 0); 3526 PROC_LOCK(p); 3527 p->p_acflag |= ACORE; 3528 PROC_UNLOCK(p); 3529 3530 if (p->p_sysent->sv_coredump != NULL) { 3531 error = p->p_sysent->sv_coredump(td, vp, limit, 3532 compress_user_cores ? IMGACT_CORE_COMPRESS : 0); 3533 } else { 3534 error = ENOSYS; 3535 } 3536 3537 if (locked) { 3538 lf.l_type = F_UNLCK; 3539 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3540 } 3541 vn_rangelock_unlock(vp, rl_cookie); 3542 3543 /* 3544 * Notify the userland helper that a process triggered a core dump. 3545 * This allows the helper to run an automated debugging session. 3546 */ 3547 if (error != 0 || coredump_devctl == 0) 3548 goto out; 3549 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3550 sizeof(' ') + sizeof(core_name) - 1; 3551 data = malloc(len, M_TEMP, M_WAITOK); 3552 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3553 goto out; 3554 if (!coredump_sanitise_path(fullpath)) 3555 goto out; 3556 snprintf(data, len, "%s%s ", comm_name, fullpath); 3557 free(freepath, M_TEMP); 3558 freepath = NULL; 3559 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3560 goto out; 3561 if (!coredump_sanitise_path(fullpath)) 3562 goto out; 3563 strlcat(data, core_name, len); 3564 strlcat(data, fullpath, len); 3565 devctl_notify("kernel", "signal", "coredump", data); 3566out: 3567 error1 = vn_close(vp, FWRITE, cred, td); 3568 if (error == 0) 3569 error = error1; 3570#ifdef AUDIT 3571 audit_proc_coredump(td, name, error); 3572#endif 3573 free(freepath, M_TEMP); 3574 free(data, M_TEMP); 3575 free(name, M_TEMP); 3576 return (error); 3577} 3578 3579/* 3580 * Nonexistent system call-- signal process (may want to handle it). Flag 3581 * error in case process won't see signal immediately (blocked or ignored). 3582 */ 3583#ifndef _SYS_SYSPROTO_H_ 3584struct nosys_args { 3585 int dummy; 3586}; 3587#endif 3588/* ARGSUSED */ 3589int 3590nosys(struct thread *td, struct nosys_args *args) 3591{ 3592 struct proc *p; 3593 3594 p = td->td_proc; 3595 3596 PROC_LOCK(p); 3597 tdsignal(td, SIGSYS); 3598 PROC_UNLOCK(p); 3599 if (kern_lognosys == 1 || kern_lognosys == 3) { 3600 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3601 td->td_sa.code); 3602 } 3603 if (kern_lognosys == 2 || kern_lognosys == 3) { 3604 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3605 td->td_sa.code); 3606 } 3607 return (ENOSYS); 3608} 3609 3610/* 3611 * Send a SIGIO or SIGURG signal to a process or process group using stored 3612 * credentials rather than those of the current process. 3613 */ 3614void 3615pgsigio(struct sigio **sigiop, int sig, int checkctty) 3616{ 3617 ksiginfo_t ksi; 3618 struct sigio *sigio; 3619 3620 ksiginfo_init(&ksi); 3621 ksi.ksi_signo = sig; 3622 ksi.ksi_code = SI_KERNEL; 3623 3624 SIGIO_LOCK(); 3625 sigio = *sigiop; 3626 if (sigio == NULL) { 3627 SIGIO_UNLOCK(); 3628 return; 3629 } 3630 if (sigio->sio_pgid > 0) { 3631 PROC_LOCK(sigio->sio_proc); 3632 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3633 kern_psignal(sigio->sio_proc, sig); 3634 PROC_UNLOCK(sigio->sio_proc); 3635 } else if (sigio->sio_pgid < 0) { 3636 struct proc *p; 3637 3638 PGRP_LOCK(sigio->sio_pgrp); 3639 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3640 PROC_LOCK(p); 3641 if (p->p_state == PRS_NORMAL && 3642 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3643 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3644 kern_psignal(p, sig); 3645 PROC_UNLOCK(p); 3646 } 3647 PGRP_UNLOCK(sigio->sio_pgrp); 3648 } 3649 SIGIO_UNLOCK(); 3650} 3651 3652static int 3653filt_sigattach(struct knote *kn) 3654{ 3655 struct proc *p = curproc; 3656 3657 kn->kn_ptr.p_proc = p; 3658 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3659 3660 knlist_add(p->p_klist, kn, 0); 3661 3662 return (0); 3663} 3664 3665static void 3666filt_sigdetach(struct knote *kn) 3667{ 3668 struct proc *p = kn->kn_ptr.p_proc; 3669 3670 knlist_remove(p->p_klist, kn, 0); 3671} 3672 3673/* 3674 * signal knotes are shared with proc knotes, so we apply a mask to 3675 * the hint in order to differentiate them from process hints. This 3676 * could be avoided by using a signal-specific knote list, but probably 3677 * isn't worth the trouble. 3678 */ 3679static int 3680filt_signal(struct knote *kn, long hint) 3681{ 3682 3683 if (hint & NOTE_SIGNAL) { 3684 hint &= ~NOTE_SIGNAL; 3685 3686 if (kn->kn_id == hint) 3687 kn->kn_data++; 3688 } 3689 return (kn->kn_data != 0); 3690} 3691 3692struct sigacts * 3693sigacts_alloc(void) 3694{ 3695 struct sigacts *ps; 3696 3697 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3698 refcount_init(&ps->ps_refcnt, 1); 3699 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3700 return (ps); 3701} 3702 3703void 3704sigacts_free(struct sigacts *ps) 3705{ 3706 3707 if (refcount_release(&ps->ps_refcnt) == 0) 3708 return; 3709 mtx_destroy(&ps->ps_mtx); 3710 free(ps, M_SUBPROC); 3711} 3712 3713struct sigacts * 3714sigacts_hold(struct sigacts *ps) 3715{ 3716 3717 refcount_acquire(&ps->ps_refcnt); 3718 return (ps); 3719} 3720 3721void 3722sigacts_copy(struct sigacts *dest, struct sigacts *src) 3723{ 3724 3725 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3726 mtx_lock(&src->ps_mtx); 3727 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3728 mtx_unlock(&src->ps_mtx); 3729} 3730 3731int 3732sigacts_shared(struct sigacts *ps) 3733{ 3734 3735 return (ps->ps_refcnt > 1); 3736} 3737