1/*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 4. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)kern_sig.c 8.7 (Berkeley) 4/18/94 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: stable/11/sys/kern/kern_sig.c 365864 2020-09-17 23:14:17Z brooks $"); 39 40#include "opt_compat.h" 41#include "opt_gzio.h" 42#include "opt_ktrace.h" 43 44#include <sys/param.h> 45#include <sys/ctype.h> 46#include <sys/systm.h> 47#include <sys/signalvar.h> 48#include <sys/vnode.h> 49#include <sys/acct.h> 50#include <sys/bus.h> 51#include <sys/capsicum.h> 52#include <sys/condvar.h> 53#include <sys/event.h> 54#include <sys/fcntl.h> 55#include <sys/imgact.h> 56#include <sys/kernel.h> 57#include <sys/ktr.h> 58#include <sys/ktrace.h> 59#include <sys/lock.h> 60#include <sys/malloc.h> 61#include <sys/mutex.h> 62#include <sys/refcount.h> 63#include <sys/namei.h> 64#include <sys/proc.h> 65#include <sys/procdesc.h> 66#include <sys/ptrace.h> 67#include <sys/posix4.h> 68#include <sys/pioctl.h> 69#include <sys/racct.h> 70#include <sys/resourcevar.h> 71#include <sys/sdt.h> 72#include <sys/sbuf.h> 73#include <sys/sleepqueue.h> 74#include <sys/smp.h> 75#include <sys/stat.h> 76#include <sys/sx.h> 77#include <sys/syscallsubr.h> 78#include <sys/sysctl.h> 79#include <sys/sysent.h> 80#include <sys/syslog.h> 81#include <sys/sysproto.h> 82#include <sys/timers.h> 83#include <sys/unistd.h> 84#include <sys/wait.h> 85#include <vm/vm.h> 86#include <vm/vm_extern.h> 87#include <vm/uma.h> 88 89#include <sys/jail.h> 90 91#include <machine/cpu.h> 92 93#include <security/audit/audit.h> 94 95#define ONSIG 32 /* NSIG for osig* syscalls. XXX. */ 96 97SDT_PROVIDER_DECLARE(proc); 98SDT_PROBE_DEFINE3(proc, , , signal__send, 99 "struct thread *", "struct proc *", "int"); 100SDT_PROBE_DEFINE2(proc, , , signal__clear, 101 "int", "ksiginfo_t *"); 102SDT_PROBE_DEFINE3(proc, , , signal__discard, 103 "struct thread *", "struct proc *", "int"); 104 105static int coredump(struct thread *); 106static int killpg1(struct thread *td, int sig, int pgid, int all, 107 ksiginfo_t *ksi); 108static int issignal(struct thread *td); 109static int sigprop(int sig); 110static void tdsigwakeup(struct thread *, int, sig_t, int); 111static int sig_suspend_threads(struct thread *, struct proc *, int); 112static int filt_sigattach(struct knote *kn); 113static void filt_sigdetach(struct knote *kn); 114static int filt_signal(struct knote *kn, long hint); 115static struct thread *sigtd(struct proc *p, int sig, int prop); 116static void sigqueue_start(void); 117 118static uma_zone_t ksiginfo_zone = NULL; 119struct filterops sig_filtops = { 120 .f_isfd = 0, 121 .f_attach = filt_sigattach, 122 .f_detach = filt_sigdetach, 123 .f_event = filt_signal, 124}; 125 126static int kern_logsigexit = 1; 127SYSCTL_INT(_kern, KERN_LOGSIGEXIT, logsigexit, CTLFLAG_RW, 128 &kern_logsigexit, 0, 129 "Log processes quitting on abnormal signals to syslog(3)"); 130 131static int kern_forcesigexit = 1; 132SYSCTL_INT(_kern, OID_AUTO, forcesigexit, CTLFLAG_RW, 133 &kern_forcesigexit, 0, "Force trap signal to be handled"); 134 135static SYSCTL_NODE(_kern, OID_AUTO, sigqueue, CTLFLAG_RW, 0, 136 "POSIX real time signal"); 137 138static int max_pending_per_proc = 128; 139SYSCTL_INT(_kern_sigqueue, OID_AUTO, max_pending_per_proc, CTLFLAG_RW, 140 &max_pending_per_proc, 0, "Max pending signals per proc"); 141 142static int preallocate_siginfo = 1024; 143SYSCTL_INT(_kern_sigqueue, OID_AUTO, preallocate, CTLFLAG_RDTUN, 144 &preallocate_siginfo, 0, "Preallocated signal memory size"); 145 146static int signal_overflow = 0; 147SYSCTL_INT(_kern_sigqueue, OID_AUTO, overflow, CTLFLAG_RD, 148 &signal_overflow, 0, "Number of signals overflew"); 149 150static int signal_alloc_fail = 0; 151SYSCTL_INT(_kern_sigqueue, OID_AUTO, alloc_fail, CTLFLAG_RD, 152 &signal_alloc_fail, 0, "signals failed to be allocated"); 153 154static int kern_lognosys = 0; 155SYSCTL_INT(_kern, OID_AUTO, lognosys, CTLFLAG_RWTUN, &kern_lognosys, 0, 156 "Log invalid syscalls"); 157 158SYSINIT(signal, SI_SUB_P1003_1B, SI_ORDER_FIRST+3, sigqueue_start, NULL); 159 160/* 161 * Policy -- Can ucred cr1 send SIGIO to process cr2? 162 * Should use cr_cansignal() once cr_cansignal() allows SIGIO and SIGURG 163 * in the right situations. 164 */ 165#define CANSIGIO(cr1, cr2) \ 166 ((cr1)->cr_uid == 0 || \ 167 (cr1)->cr_ruid == (cr2)->cr_ruid || \ 168 (cr1)->cr_uid == (cr2)->cr_ruid || \ 169 (cr1)->cr_ruid == (cr2)->cr_uid || \ 170 (cr1)->cr_uid == (cr2)->cr_uid) 171 172static int sugid_coredump; 173SYSCTL_INT(_kern, OID_AUTO, sugid_coredump, CTLFLAG_RWTUN, 174 &sugid_coredump, 0, "Allow setuid and setgid processes to dump core"); 175 176static int capmode_coredump; 177SYSCTL_INT(_kern, OID_AUTO, capmode_coredump, CTLFLAG_RWTUN, 178 &capmode_coredump, 0, "Allow processes in capability mode to dump core"); 179 180static int do_coredump = 1; 181SYSCTL_INT(_kern, OID_AUTO, coredump, CTLFLAG_RW, 182 &do_coredump, 0, "Enable/Disable coredumps"); 183 184static int set_core_nodump_flag = 0; 185SYSCTL_INT(_kern, OID_AUTO, nodump_coredump, CTLFLAG_RW, &set_core_nodump_flag, 186 0, "Enable setting the NODUMP flag on coredump files"); 187 188static int coredump_devctl = 0; 189SYSCTL_INT(_kern, OID_AUTO, coredump_devctl, CTLFLAG_RW, &coredump_devctl, 190 0, "Generate a devctl notification when processes coredump"); 191 192/* 193 * Signal properties and actions. 194 * The array below categorizes the signals and their default actions 195 * according to the following properties: 196 */ 197#define SA_KILL 0x01 /* terminates process by default */ 198#define SA_CORE 0x02 /* ditto and coredumps */ 199#define SA_STOP 0x04 /* suspend process */ 200#define SA_TTYSTOP 0x08 /* ditto, from tty */ 201#define SA_IGNORE 0x10 /* ignore by default */ 202#define SA_CONT 0x20 /* continue if suspended */ 203#define SA_CANTMASK 0x40 /* non-maskable, catchable */ 204 205static int sigproptbl[NSIG] = { 206 SA_KILL, /* SIGHUP */ 207 SA_KILL, /* SIGINT */ 208 SA_KILL|SA_CORE, /* SIGQUIT */ 209 SA_KILL|SA_CORE, /* SIGILL */ 210 SA_KILL|SA_CORE, /* SIGTRAP */ 211 SA_KILL|SA_CORE, /* SIGABRT */ 212 SA_KILL|SA_CORE, /* SIGEMT */ 213 SA_KILL|SA_CORE, /* SIGFPE */ 214 SA_KILL, /* SIGKILL */ 215 SA_KILL|SA_CORE, /* SIGBUS */ 216 SA_KILL|SA_CORE, /* SIGSEGV */ 217 SA_KILL|SA_CORE, /* SIGSYS */ 218 SA_KILL, /* SIGPIPE */ 219 SA_KILL, /* SIGALRM */ 220 SA_KILL, /* SIGTERM */ 221 SA_IGNORE, /* SIGURG */ 222 SA_STOP, /* SIGSTOP */ 223 SA_STOP|SA_TTYSTOP, /* SIGTSTP */ 224 SA_IGNORE|SA_CONT, /* SIGCONT */ 225 SA_IGNORE, /* SIGCHLD */ 226 SA_STOP|SA_TTYSTOP, /* SIGTTIN */ 227 SA_STOP|SA_TTYSTOP, /* SIGTTOU */ 228 SA_IGNORE, /* SIGIO */ 229 SA_KILL, /* SIGXCPU */ 230 SA_KILL, /* SIGXFSZ */ 231 SA_KILL, /* SIGVTALRM */ 232 SA_KILL, /* SIGPROF */ 233 SA_IGNORE, /* SIGWINCH */ 234 SA_IGNORE, /* SIGINFO */ 235 SA_KILL, /* SIGUSR1 */ 236 SA_KILL, /* SIGUSR2 */ 237}; 238 239static void reschedule_signals(struct proc *p, sigset_t block, int flags); 240 241static void 242sigqueue_start(void) 243{ 244 ksiginfo_zone = uma_zcreate("ksiginfo", sizeof(ksiginfo_t), 245 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); 246 uma_prealloc(ksiginfo_zone, preallocate_siginfo); 247 p31b_setcfg(CTL_P1003_1B_REALTIME_SIGNALS, _POSIX_REALTIME_SIGNALS); 248 p31b_setcfg(CTL_P1003_1B_RTSIG_MAX, SIGRTMAX - SIGRTMIN + 1); 249 p31b_setcfg(CTL_P1003_1B_SIGQUEUE_MAX, max_pending_per_proc); 250} 251 252ksiginfo_t * 253ksiginfo_alloc(int wait) 254{ 255 int flags; 256 257 flags = M_ZERO; 258 if (! wait) 259 flags |= M_NOWAIT; 260 if (ksiginfo_zone != NULL) 261 return ((ksiginfo_t *)uma_zalloc(ksiginfo_zone, flags)); 262 return (NULL); 263} 264 265void 266ksiginfo_free(ksiginfo_t *ksi) 267{ 268 uma_zfree(ksiginfo_zone, ksi); 269} 270 271static __inline int 272ksiginfo_tryfree(ksiginfo_t *ksi) 273{ 274 if (!(ksi->ksi_flags & KSI_EXT)) { 275 uma_zfree(ksiginfo_zone, ksi); 276 return (1); 277 } 278 return (0); 279} 280 281void 282sigqueue_init(sigqueue_t *list, struct proc *p) 283{ 284 SIGEMPTYSET(list->sq_signals); 285 SIGEMPTYSET(list->sq_kill); 286 SIGEMPTYSET(list->sq_ptrace); 287 TAILQ_INIT(&list->sq_list); 288 list->sq_proc = p; 289 list->sq_flags = SQ_INIT; 290} 291 292/* 293 * Get a signal's ksiginfo. 294 * Return: 295 * 0 - signal not found 296 * others - signal number 297 */ 298static int 299sigqueue_get(sigqueue_t *sq, int signo, ksiginfo_t *si) 300{ 301 struct proc *p = sq->sq_proc; 302 struct ksiginfo *ksi, *next; 303 int count = 0; 304 305 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 306 307 if (!SIGISMEMBER(sq->sq_signals, signo)) 308 return (0); 309 310 if (SIGISMEMBER(sq->sq_ptrace, signo)) { 311 count++; 312 SIGDELSET(sq->sq_ptrace, signo); 313 si->ksi_flags |= KSI_PTRACE; 314 } 315 if (SIGISMEMBER(sq->sq_kill, signo)) { 316 count++; 317 if (count == 1) 318 SIGDELSET(sq->sq_kill, signo); 319 } 320 321 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 322 if (ksi->ksi_signo == signo) { 323 if (count == 0) { 324 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 325 ksi->ksi_sigq = NULL; 326 ksiginfo_copy(ksi, si); 327 if (ksiginfo_tryfree(ksi) && p != NULL) 328 p->p_pendingcnt--; 329 } 330 if (++count > 1) 331 break; 332 } 333 } 334 335 if (count <= 1) 336 SIGDELSET(sq->sq_signals, signo); 337 si->ksi_signo = signo; 338 return (signo); 339} 340 341void 342sigqueue_take(ksiginfo_t *ksi) 343{ 344 struct ksiginfo *kp; 345 struct proc *p; 346 sigqueue_t *sq; 347 348 if (ksi == NULL || (sq = ksi->ksi_sigq) == NULL) 349 return; 350 351 p = sq->sq_proc; 352 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 353 ksi->ksi_sigq = NULL; 354 if (!(ksi->ksi_flags & KSI_EXT) && p != NULL) 355 p->p_pendingcnt--; 356 357 for (kp = TAILQ_FIRST(&sq->sq_list); kp != NULL; 358 kp = TAILQ_NEXT(kp, ksi_link)) { 359 if (kp->ksi_signo == ksi->ksi_signo) 360 break; 361 } 362 if (kp == NULL && !SIGISMEMBER(sq->sq_kill, ksi->ksi_signo) && 363 !SIGISMEMBER(sq->sq_ptrace, ksi->ksi_signo)) 364 SIGDELSET(sq->sq_signals, ksi->ksi_signo); 365} 366 367static int 368sigqueue_add(sigqueue_t *sq, int signo, ksiginfo_t *si) 369{ 370 struct proc *p = sq->sq_proc; 371 struct ksiginfo *ksi; 372 int ret = 0; 373 374 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 375 376 /* 377 * SIGKILL/SIGSTOP cannot be caught or masked, so take the fast path 378 * for these signals. 379 */ 380 if (signo == SIGKILL || signo == SIGSTOP || si == NULL) { 381 SIGADDSET(sq->sq_kill, signo); 382 goto out_set_bit; 383 } 384 385 /* directly insert the ksi, don't copy it */ 386 if (si->ksi_flags & KSI_INS) { 387 if (si->ksi_flags & KSI_HEAD) 388 TAILQ_INSERT_HEAD(&sq->sq_list, si, ksi_link); 389 else 390 TAILQ_INSERT_TAIL(&sq->sq_list, si, ksi_link); 391 si->ksi_sigq = sq; 392 goto out_set_bit; 393 } 394 395 if (__predict_false(ksiginfo_zone == NULL)) { 396 SIGADDSET(sq->sq_kill, signo); 397 goto out_set_bit; 398 } 399 400 if (p != NULL && p->p_pendingcnt >= max_pending_per_proc) { 401 signal_overflow++; 402 ret = EAGAIN; 403 } else if ((ksi = ksiginfo_alloc(0)) == NULL) { 404 signal_alloc_fail++; 405 ret = EAGAIN; 406 } else { 407 if (p != NULL) 408 p->p_pendingcnt++; 409 ksiginfo_copy(si, ksi); 410 ksi->ksi_signo = signo; 411 if (si->ksi_flags & KSI_HEAD) 412 TAILQ_INSERT_HEAD(&sq->sq_list, ksi, ksi_link); 413 else 414 TAILQ_INSERT_TAIL(&sq->sq_list, ksi, ksi_link); 415 ksi->ksi_sigq = sq; 416 } 417 418 if (ret != 0) { 419 if ((si->ksi_flags & KSI_PTRACE) != 0) { 420 SIGADDSET(sq->sq_ptrace, signo); 421 ret = 0; 422 goto out_set_bit; 423 } else if ((si->ksi_flags & KSI_TRAP) != 0 || 424 (si->ksi_flags & KSI_SIGQ) == 0) { 425 SIGADDSET(sq->sq_kill, signo); 426 ret = 0; 427 goto out_set_bit; 428 } 429 return (ret); 430 } 431 432out_set_bit: 433 SIGADDSET(sq->sq_signals, signo); 434 return (ret); 435} 436 437void 438sigqueue_flush(sigqueue_t *sq) 439{ 440 struct proc *p = sq->sq_proc; 441 ksiginfo_t *ksi; 442 443 KASSERT(sq->sq_flags & SQ_INIT, ("sigqueue not inited")); 444 445 if (p != NULL) 446 PROC_LOCK_ASSERT(p, MA_OWNED); 447 448 while ((ksi = TAILQ_FIRST(&sq->sq_list)) != NULL) { 449 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 450 ksi->ksi_sigq = NULL; 451 if (ksiginfo_tryfree(ksi) && p != NULL) 452 p->p_pendingcnt--; 453 } 454 455 SIGEMPTYSET(sq->sq_signals); 456 SIGEMPTYSET(sq->sq_kill); 457 SIGEMPTYSET(sq->sq_ptrace); 458} 459 460static void 461sigqueue_move_set(sigqueue_t *src, sigqueue_t *dst, const sigset_t *set) 462{ 463 sigset_t tmp; 464 struct proc *p1, *p2; 465 ksiginfo_t *ksi, *next; 466 467 KASSERT(src->sq_flags & SQ_INIT, ("src sigqueue not inited")); 468 KASSERT(dst->sq_flags & SQ_INIT, ("dst sigqueue not inited")); 469 p1 = src->sq_proc; 470 p2 = dst->sq_proc; 471 /* Move siginfo to target list */ 472 TAILQ_FOREACH_SAFE(ksi, &src->sq_list, ksi_link, next) { 473 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 474 TAILQ_REMOVE(&src->sq_list, ksi, ksi_link); 475 if (p1 != NULL) 476 p1->p_pendingcnt--; 477 TAILQ_INSERT_TAIL(&dst->sq_list, ksi, ksi_link); 478 ksi->ksi_sigq = dst; 479 if (p2 != NULL) 480 p2->p_pendingcnt++; 481 } 482 } 483 484 /* Move pending bits to target list */ 485 tmp = src->sq_kill; 486 SIGSETAND(tmp, *set); 487 SIGSETOR(dst->sq_kill, tmp); 488 SIGSETNAND(src->sq_kill, tmp); 489 490 tmp = src->sq_ptrace; 491 SIGSETAND(tmp, *set); 492 SIGSETOR(dst->sq_ptrace, tmp); 493 SIGSETNAND(src->sq_ptrace, tmp); 494 495 tmp = src->sq_signals; 496 SIGSETAND(tmp, *set); 497 SIGSETOR(dst->sq_signals, tmp); 498 SIGSETNAND(src->sq_signals, tmp); 499} 500 501#if 0 502static void 503sigqueue_move(sigqueue_t *src, sigqueue_t *dst, int signo) 504{ 505 sigset_t set; 506 507 SIGEMPTYSET(set); 508 SIGADDSET(set, signo); 509 sigqueue_move_set(src, dst, &set); 510} 511#endif 512 513static void 514sigqueue_delete_set(sigqueue_t *sq, const sigset_t *set) 515{ 516 struct proc *p = sq->sq_proc; 517 ksiginfo_t *ksi, *next; 518 519 KASSERT(sq->sq_flags & SQ_INIT, ("src sigqueue not inited")); 520 521 /* Remove siginfo queue */ 522 TAILQ_FOREACH_SAFE(ksi, &sq->sq_list, ksi_link, next) { 523 if (SIGISMEMBER(*set, ksi->ksi_signo)) { 524 TAILQ_REMOVE(&sq->sq_list, ksi, ksi_link); 525 ksi->ksi_sigq = NULL; 526 if (ksiginfo_tryfree(ksi) && p != NULL) 527 p->p_pendingcnt--; 528 } 529 } 530 SIGSETNAND(sq->sq_kill, *set); 531 SIGSETNAND(sq->sq_ptrace, *set); 532 SIGSETNAND(sq->sq_signals, *set); 533} 534 535void 536sigqueue_delete(sigqueue_t *sq, int signo) 537{ 538 sigset_t set; 539 540 SIGEMPTYSET(set); 541 SIGADDSET(set, signo); 542 sigqueue_delete_set(sq, &set); 543} 544 545/* Remove a set of signals for a process */ 546static void 547sigqueue_delete_set_proc(struct proc *p, const sigset_t *set) 548{ 549 sigqueue_t worklist; 550 struct thread *td0; 551 552 PROC_LOCK_ASSERT(p, MA_OWNED); 553 554 sigqueue_init(&worklist, NULL); 555 sigqueue_move_set(&p->p_sigqueue, &worklist, set); 556 557 FOREACH_THREAD_IN_PROC(p, td0) 558 sigqueue_move_set(&td0->td_sigqueue, &worklist, set); 559 560 sigqueue_flush(&worklist); 561} 562 563void 564sigqueue_delete_proc(struct proc *p, int signo) 565{ 566 sigset_t set; 567 568 SIGEMPTYSET(set); 569 SIGADDSET(set, signo); 570 sigqueue_delete_set_proc(p, &set); 571} 572 573static void 574sigqueue_delete_stopmask_proc(struct proc *p) 575{ 576 sigset_t set; 577 578 SIGEMPTYSET(set); 579 SIGADDSET(set, SIGSTOP); 580 SIGADDSET(set, SIGTSTP); 581 SIGADDSET(set, SIGTTIN); 582 SIGADDSET(set, SIGTTOU); 583 sigqueue_delete_set_proc(p, &set); 584} 585 586/* 587 * Determine signal that should be delivered to thread td, the current 588 * thread, 0 if none. If there is a pending stop signal with default 589 * action, the process stops in issignal(). 590 */ 591int 592cursig(struct thread *td) 593{ 594 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 595 mtx_assert(&td->td_proc->p_sigacts->ps_mtx, MA_OWNED); 596 THREAD_LOCK_ASSERT(td, MA_NOTOWNED); 597 return (SIGPENDING(td) ? issignal(td) : 0); 598} 599 600/* 601 * Arrange for ast() to handle unmasked pending signals on return to user 602 * mode. This must be called whenever a signal is added to td_sigqueue or 603 * unmasked in td_sigmask. 604 */ 605void 606signotify(struct thread *td) 607{ 608 struct proc *p; 609 610 p = td->td_proc; 611 612 PROC_LOCK_ASSERT(p, MA_OWNED); 613 614 if (SIGPENDING(td)) { 615 thread_lock(td); 616 td->td_flags |= TDF_NEEDSIGCHK | TDF_ASTPENDING; 617 thread_unlock(td); 618 } 619} 620 621/* 622 * Returns 1 (true) if altstack is configured for the thread, and the 623 * passed stack bottom address falls into the altstack range. Handles 624 * the 43 compat special case where the alt stack size is zero. 625 */ 626int 627sigonstack(size_t sp) 628{ 629 struct thread *td; 630 631 td = curthread; 632 if ((td->td_pflags & TDP_ALTSTACK) == 0) 633 return (0); 634#if defined(COMPAT_43) 635 if (td->td_sigstk.ss_size == 0) 636 return ((td->td_sigstk.ss_flags & SS_ONSTACK) != 0); 637#endif 638 return (sp >= (size_t)td->td_sigstk.ss_sp && 639 sp < td->td_sigstk.ss_size + (size_t)td->td_sigstk.ss_sp); 640} 641 642static __inline int 643sigprop(int sig) 644{ 645 646 if (sig > 0 && sig < NSIG) 647 return (sigproptbl[_SIG_IDX(sig)]); 648 return (0); 649} 650 651int 652sig_ffs(sigset_t *set) 653{ 654 int i; 655 656 for (i = 0; i < _SIG_WORDS; i++) 657 if (set->__bits[i]) 658 return (ffs(set->__bits[i]) + (i * 32)); 659 return (0); 660} 661 662static bool 663sigact_flag_test(const struct sigaction *act, int flag) 664{ 665 666 /* 667 * SA_SIGINFO is reset when signal disposition is set to 668 * ignore or default. Other flags are kept according to user 669 * settings. 670 */ 671 return ((act->sa_flags & flag) != 0 && (flag != SA_SIGINFO || 672 ((__sighandler_t *)act->sa_sigaction != SIG_IGN && 673 (__sighandler_t *)act->sa_sigaction != SIG_DFL))); 674} 675 676/* 677 * kern_sigaction 678 * sigaction 679 * freebsd4_sigaction 680 * osigaction 681 */ 682int 683kern_sigaction(struct thread *td, int sig, const struct sigaction *act, 684 struct sigaction *oact, int flags) 685{ 686 struct sigacts *ps; 687 struct proc *p = td->td_proc; 688 689 if (!_SIG_VALID(sig)) 690 return (EINVAL); 691 if (act != NULL && act->sa_handler != SIG_DFL && 692 act->sa_handler != SIG_IGN && (act->sa_flags & ~(SA_ONSTACK | 693 SA_RESTART | SA_RESETHAND | SA_NOCLDSTOP | SA_NODEFER | 694 SA_NOCLDWAIT | SA_SIGINFO)) != 0) 695 return (EINVAL); 696 697 PROC_LOCK(p); 698 ps = p->p_sigacts; 699 mtx_lock(&ps->ps_mtx); 700 if (oact) { 701 memset(oact, 0, sizeof(*oact)); 702 oact->sa_mask = ps->ps_catchmask[_SIG_IDX(sig)]; 703 if (SIGISMEMBER(ps->ps_sigonstack, sig)) 704 oact->sa_flags |= SA_ONSTACK; 705 if (!SIGISMEMBER(ps->ps_sigintr, sig)) 706 oact->sa_flags |= SA_RESTART; 707 if (SIGISMEMBER(ps->ps_sigreset, sig)) 708 oact->sa_flags |= SA_RESETHAND; 709 if (SIGISMEMBER(ps->ps_signodefer, sig)) 710 oact->sa_flags |= SA_NODEFER; 711 if (SIGISMEMBER(ps->ps_siginfo, sig)) { 712 oact->sa_flags |= SA_SIGINFO; 713 oact->sa_sigaction = 714 (__siginfohandler_t *)ps->ps_sigact[_SIG_IDX(sig)]; 715 } else 716 oact->sa_handler = ps->ps_sigact[_SIG_IDX(sig)]; 717 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDSTOP) 718 oact->sa_flags |= SA_NOCLDSTOP; 719 if (sig == SIGCHLD && ps->ps_flag & PS_NOCLDWAIT) 720 oact->sa_flags |= SA_NOCLDWAIT; 721 } 722 if (act) { 723 if ((sig == SIGKILL || sig == SIGSTOP) && 724 act->sa_handler != SIG_DFL) { 725 mtx_unlock(&ps->ps_mtx); 726 PROC_UNLOCK(p); 727 return (EINVAL); 728 } 729 730 /* 731 * Change setting atomically. 732 */ 733 734 ps->ps_catchmask[_SIG_IDX(sig)] = act->sa_mask; 735 SIG_CANTMASK(ps->ps_catchmask[_SIG_IDX(sig)]); 736 if (sigact_flag_test(act, SA_SIGINFO)) { 737 ps->ps_sigact[_SIG_IDX(sig)] = 738 (__sighandler_t *)act->sa_sigaction; 739 SIGADDSET(ps->ps_siginfo, sig); 740 } else { 741 ps->ps_sigact[_SIG_IDX(sig)] = act->sa_handler; 742 SIGDELSET(ps->ps_siginfo, sig); 743 } 744 if (!sigact_flag_test(act, SA_RESTART)) 745 SIGADDSET(ps->ps_sigintr, sig); 746 else 747 SIGDELSET(ps->ps_sigintr, sig); 748 if (sigact_flag_test(act, SA_ONSTACK)) 749 SIGADDSET(ps->ps_sigonstack, sig); 750 else 751 SIGDELSET(ps->ps_sigonstack, sig); 752 if (sigact_flag_test(act, SA_RESETHAND)) 753 SIGADDSET(ps->ps_sigreset, sig); 754 else 755 SIGDELSET(ps->ps_sigreset, sig); 756 if (sigact_flag_test(act, SA_NODEFER)) 757 SIGADDSET(ps->ps_signodefer, sig); 758 else 759 SIGDELSET(ps->ps_signodefer, sig); 760 if (sig == SIGCHLD) { 761 if (act->sa_flags & SA_NOCLDSTOP) 762 ps->ps_flag |= PS_NOCLDSTOP; 763 else 764 ps->ps_flag &= ~PS_NOCLDSTOP; 765 if (act->sa_flags & SA_NOCLDWAIT) { 766 /* 767 * Paranoia: since SA_NOCLDWAIT is implemented 768 * by reparenting the dying child to PID 1 (and 769 * trust it to reap the zombie), PID 1 itself 770 * is forbidden to set SA_NOCLDWAIT. 771 */ 772 if (p->p_pid == 1) 773 ps->ps_flag &= ~PS_NOCLDWAIT; 774 else 775 ps->ps_flag |= PS_NOCLDWAIT; 776 } else 777 ps->ps_flag &= ~PS_NOCLDWAIT; 778 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 779 ps->ps_flag |= PS_CLDSIGIGN; 780 else 781 ps->ps_flag &= ~PS_CLDSIGIGN; 782 } 783 /* 784 * Set bit in ps_sigignore for signals that are set to SIG_IGN, 785 * and for signals set to SIG_DFL where the default is to 786 * ignore. However, don't put SIGCONT in ps_sigignore, as we 787 * have to restart the process. 788 */ 789 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 790 (sigprop(sig) & SA_IGNORE && 791 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL)) { 792 /* never to be seen again */ 793 sigqueue_delete_proc(p, sig); 794 if (sig != SIGCONT) 795 /* easier in psignal */ 796 SIGADDSET(ps->ps_sigignore, sig); 797 SIGDELSET(ps->ps_sigcatch, sig); 798 } else { 799 SIGDELSET(ps->ps_sigignore, sig); 800 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL) 801 SIGDELSET(ps->ps_sigcatch, sig); 802 else 803 SIGADDSET(ps->ps_sigcatch, sig); 804 } 805#ifdef COMPAT_FREEBSD4 806 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 807 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 808 (flags & KSA_FREEBSD4) == 0) 809 SIGDELSET(ps->ps_freebsd4, sig); 810 else 811 SIGADDSET(ps->ps_freebsd4, sig); 812#endif 813#ifdef COMPAT_43 814 if (ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN || 815 ps->ps_sigact[_SIG_IDX(sig)] == SIG_DFL || 816 (flags & KSA_OSIGSET) == 0) 817 SIGDELSET(ps->ps_osigset, sig); 818 else 819 SIGADDSET(ps->ps_osigset, sig); 820#endif 821 } 822 mtx_unlock(&ps->ps_mtx); 823 PROC_UNLOCK(p); 824 return (0); 825} 826 827#ifndef _SYS_SYSPROTO_H_ 828struct sigaction_args { 829 int sig; 830 struct sigaction *act; 831 struct sigaction *oact; 832}; 833#endif 834int 835sys_sigaction(struct thread *td, struct sigaction_args *uap) 836{ 837 struct sigaction act, oact; 838 struct sigaction *actp, *oactp; 839 int error; 840 841 actp = (uap->act != NULL) ? &act : NULL; 842 oactp = (uap->oact != NULL) ? &oact : NULL; 843 if (actp) { 844 error = copyin(uap->act, actp, sizeof(act)); 845 if (error) 846 return (error); 847 } 848 error = kern_sigaction(td, uap->sig, actp, oactp, 0); 849 if (oactp && !error) 850 error = copyout(oactp, uap->oact, sizeof(oact)); 851 return (error); 852} 853 854#ifdef COMPAT_FREEBSD4 855#ifndef _SYS_SYSPROTO_H_ 856struct freebsd4_sigaction_args { 857 int sig; 858 struct sigaction *act; 859 struct sigaction *oact; 860}; 861#endif 862int 863freebsd4_sigaction(struct thread *td, struct freebsd4_sigaction_args *uap) 864{ 865 struct sigaction act, oact; 866 struct sigaction *actp, *oactp; 867 int error; 868 869 870 actp = (uap->act != NULL) ? &act : NULL; 871 oactp = (uap->oact != NULL) ? &oact : NULL; 872 if (actp) { 873 error = copyin(uap->act, actp, sizeof(act)); 874 if (error) 875 return (error); 876 } 877 error = kern_sigaction(td, uap->sig, actp, oactp, KSA_FREEBSD4); 878 if (oactp && !error) 879 error = copyout(oactp, uap->oact, sizeof(oact)); 880 return (error); 881} 882#endif /* COMAPT_FREEBSD4 */ 883 884#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 885#ifndef _SYS_SYSPROTO_H_ 886struct osigaction_args { 887 int signum; 888 struct osigaction *nsa; 889 struct osigaction *osa; 890}; 891#endif 892int 893osigaction(struct thread *td, struct osigaction_args *uap) 894{ 895 struct osigaction sa; 896 struct sigaction nsa, osa; 897 struct sigaction *nsap, *osap; 898 int error; 899 900 if (uap->signum <= 0 || uap->signum >= ONSIG) 901 return (EINVAL); 902 903 nsap = (uap->nsa != NULL) ? &nsa : NULL; 904 osap = (uap->osa != NULL) ? &osa : NULL; 905 906 if (nsap) { 907 error = copyin(uap->nsa, &sa, sizeof(sa)); 908 if (error) 909 return (error); 910 nsap->sa_handler = sa.sa_handler; 911 nsap->sa_flags = sa.sa_flags; 912 OSIG2SIG(sa.sa_mask, nsap->sa_mask); 913 } 914 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 915 if (osap && !error) { 916 sa.sa_handler = osap->sa_handler; 917 sa.sa_flags = osap->sa_flags; 918 SIG2OSIG(osap->sa_mask, sa.sa_mask); 919 error = copyout(&sa, uap->osa, sizeof(sa)); 920 } 921 return (error); 922} 923 924#if !defined(__i386__) 925/* Avoid replicating the same stub everywhere */ 926int 927osigreturn(struct thread *td, struct osigreturn_args *uap) 928{ 929 930 return (nosys(td, (struct nosys_args *)uap)); 931} 932#endif 933#endif /* COMPAT_43 */ 934 935/* 936 * Initialize signal state for process 0; 937 * set to ignore signals that are ignored by default. 938 */ 939void 940siginit(struct proc *p) 941{ 942 int i; 943 struct sigacts *ps; 944 945 PROC_LOCK(p); 946 ps = p->p_sigacts; 947 mtx_lock(&ps->ps_mtx); 948 for (i = 1; i <= NSIG; i++) { 949 if (sigprop(i) & SA_IGNORE && i != SIGCONT) { 950 SIGADDSET(ps->ps_sigignore, i); 951 } 952 } 953 mtx_unlock(&ps->ps_mtx); 954 PROC_UNLOCK(p); 955} 956 957/* 958 * Reset specified signal to the default disposition. 959 */ 960static void 961sigdflt(struct sigacts *ps, int sig) 962{ 963 964 mtx_assert(&ps->ps_mtx, MA_OWNED); 965 SIGDELSET(ps->ps_sigcatch, sig); 966 if ((sigprop(sig) & SA_IGNORE) != 0 && sig != SIGCONT) 967 SIGADDSET(ps->ps_sigignore, sig); 968 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 969 SIGDELSET(ps->ps_siginfo, sig); 970} 971 972/* 973 * Reset signals for an exec of the specified process. 974 */ 975void 976execsigs(struct proc *p) 977{ 978 sigset_t osigignore; 979 struct sigacts *ps; 980 int sig; 981 struct thread *td; 982 983 /* 984 * Reset caught signals. Held signals remain held 985 * through td_sigmask (unless they were caught, 986 * and are now ignored by default). 987 */ 988 PROC_LOCK_ASSERT(p, MA_OWNED); 989 ps = p->p_sigacts; 990 mtx_lock(&ps->ps_mtx); 991 sig_drop_caught(p); 992 993 /* 994 * As CloudABI processes cannot modify signal handlers, fully 995 * reset all signals to their default behavior. Do ignore 996 * SIGPIPE, as it would otherwise be impossible to recover from 997 * writes to broken pipes and sockets. 998 */ 999 if (SV_PROC_ABI(p) == SV_ABI_CLOUDABI) { 1000 osigignore = ps->ps_sigignore; 1001 while (SIGNOTEMPTY(osigignore)) { 1002 sig = sig_ffs(&osigignore); 1003 SIGDELSET(osigignore, sig); 1004 if (sig != SIGPIPE) 1005 sigdflt(ps, sig); 1006 } 1007 SIGADDSET(ps->ps_sigignore, SIGPIPE); 1008 } 1009 1010 /* 1011 * Reset stack state to the user stack. 1012 * Clear set of signals caught on the signal stack. 1013 */ 1014 td = curthread; 1015 MPASS(td->td_proc == p); 1016 td->td_sigstk.ss_flags = SS_DISABLE; 1017 td->td_sigstk.ss_size = 0; 1018 td->td_sigstk.ss_sp = 0; 1019 td->td_pflags &= ~TDP_ALTSTACK; 1020 /* 1021 * Reset no zombies if child dies flag as Solaris does. 1022 */ 1023 ps->ps_flag &= ~(PS_NOCLDWAIT | PS_CLDSIGIGN); 1024 if (ps->ps_sigact[_SIG_IDX(SIGCHLD)] == SIG_IGN) 1025 ps->ps_sigact[_SIG_IDX(SIGCHLD)] = SIG_DFL; 1026 mtx_unlock(&ps->ps_mtx); 1027} 1028 1029/* 1030 * kern_sigprocmask() 1031 * 1032 * Manipulate signal mask. 1033 */ 1034int 1035kern_sigprocmask(struct thread *td, int how, sigset_t *set, sigset_t *oset, 1036 int flags) 1037{ 1038 sigset_t new_block, oset1; 1039 struct proc *p; 1040 int error; 1041 1042 p = td->td_proc; 1043 if ((flags & SIGPROCMASK_PROC_LOCKED) != 0) 1044 PROC_LOCK_ASSERT(p, MA_OWNED); 1045 else 1046 PROC_LOCK(p); 1047 mtx_assert(&p->p_sigacts->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 1048 ? MA_OWNED : MA_NOTOWNED); 1049 if (oset != NULL) 1050 *oset = td->td_sigmask; 1051 1052 error = 0; 1053 if (set != NULL) { 1054 switch (how) { 1055 case SIG_BLOCK: 1056 SIG_CANTMASK(*set); 1057 oset1 = td->td_sigmask; 1058 SIGSETOR(td->td_sigmask, *set); 1059 new_block = td->td_sigmask; 1060 SIGSETNAND(new_block, oset1); 1061 break; 1062 case SIG_UNBLOCK: 1063 SIGSETNAND(td->td_sigmask, *set); 1064 signotify(td); 1065 goto out; 1066 case SIG_SETMASK: 1067 SIG_CANTMASK(*set); 1068 oset1 = td->td_sigmask; 1069 if (flags & SIGPROCMASK_OLD) 1070 SIGSETLO(td->td_sigmask, *set); 1071 else 1072 td->td_sigmask = *set; 1073 new_block = td->td_sigmask; 1074 SIGSETNAND(new_block, oset1); 1075 signotify(td); 1076 break; 1077 default: 1078 error = EINVAL; 1079 goto out; 1080 } 1081 1082 /* 1083 * The new_block set contains signals that were not previously 1084 * blocked, but are blocked now. 1085 * 1086 * In case we block any signal that was not previously blocked 1087 * for td, and process has the signal pending, try to schedule 1088 * signal delivery to some thread that does not block the 1089 * signal, possibly waking it up. 1090 */ 1091 if (p->p_numthreads != 1) 1092 reschedule_signals(p, new_block, flags); 1093 } 1094 1095out: 1096 if (!(flags & SIGPROCMASK_PROC_LOCKED)) 1097 PROC_UNLOCK(p); 1098 return (error); 1099} 1100 1101#ifndef _SYS_SYSPROTO_H_ 1102struct sigprocmask_args { 1103 int how; 1104 const sigset_t *set; 1105 sigset_t *oset; 1106}; 1107#endif 1108int 1109sys_sigprocmask(struct thread *td, struct sigprocmask_args *uap) 1110{ 1111 sigset_t set, oset; 1112 sigset_t *setp, *osetp; 1113 int error; 1114 1115 setp = (uap->set != NULL) ? &set : NULL; 1116 osetp = (uap->oset != NULL) ? &oset : NULL; 1117 if (setp) { 1118 error = copyin(uap->set, setp, sizeof(set)); 1119 if (error) 1120 return (error); 1121 } 1122 error = kern_sigprocmask(td, uap->how, setp, osetp, 0); 1123 if (osetp && !error) { 1124 error = copyout(osetp, uap->oset, sizeof(oset)); 1125 } 1126 return (error); 1127} 1128 1129#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1130#ifndef _SYS_SYSPROTO_H_ 1131struct osigprocmask_args { 1132 int how; 1133 osigset_t mask; 1134}; 1135#endif 1136int 1137osigprocmask(struct thread *td, struct osigprocmask_args *uap) 1138{ 1139 sigset_t set, oset; 1140 int error; 1141 1142 OSIG2SIG(uap->mask, set); 1143 error = kern_sigprocmask(td, uap->how, &set, &oset, 1); 1144 SIG2OSIG(oset, td->td_retval[0]); 1145 return (error); 1146} 1147#endif /* COMPAT_43 */ 1148 1149int 1150sys_sigwait(struct thread *td, struct sigwait_args *uap) 1151{ 1152 ksiginfo_t ksi; 1153 sigset_t set; 1154 int error; 1155 1156 error = copyin(uap->set, &set, sizeof(set)); 1157 if (error) { 1158 td->td_retval[0] = error; 1159 return (0); 1160 } 1161 1162 error = kern_sigtimedwait(td, set, &ksi, NULL); 1163 if (error) { 1164 if (error == EINTR && td->td_proc->p_osrel < P_OSREL_SIGWAIT) 1165 error = ERESTART; 1166 if (error == ERESTART) 1167 return (error); 1168 td->td_retval[0] = error; 1169 return (0); 1170 } 1171 1172 error = copyout(&ksi.ksi_signo, uap->sig, sizeof(ksi.ksi_signo)); 1173 td->td_retval[0] = error; 1174 return (0); 1175} 1176 1177int 1178sys_sigtimedwait(struct thread *td, struct sigtimedwait_args *uap) 1179{ 1180 struct timespec ts; 1181 struct timespec *timeout; 1182 sigset_t set; 1183 ksiginfo_t ksi; 1184 int error; 1185 1186 if (uap->timeout) { 1187 error = copyin(uap->timeout, &ts, sizeof(ts)); 1188 if (error) 1189 return (error); 1190 1191 timeout = &ts; 1192 } else 1193 timeout = NULL; 1194 1195 error = copyin(uap->set, &set, sizeof(set)); 1196 if (error) 1197 return (error); 1198 1199 error = kern_sigtimedwait(td, set, &ksi, timeout); 1200 if (error) 1201 return (error); 1202 1203 if (uap->info) 1204 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1205 1206 if (error == 0) 1207 td->td_retval[0] = ksi.ksi_signo; 1208 return (error); 1209} 1210 1211int 1212sys_sigwaitinfo(struct thread *td, struct sigwaitinfo_args *uap) 1213{ 1214 ksiginfo_t ksi; 1215 sigset_t set; 1216 int error; 1217 1218 error = copyin(uap->set, &set, sizeof(set)); 1219 if (error) 1220 return (error); 1221 1222 error = kern_sigtimedwait(td, set, &ksi, NULL); 1223 if (error) 1224 return (error); 1225 1226 if (uap->info) 1227 error = copyout(&ksi.ksi_info, uap->info, sizeof(siginfo_t)); 1228 1229 if (error == 0) 1230 td->td_retval[0] = ksi.ksi_signo; 1231 return (error); 1232} 1233 1234static void 1235proc_td_siginfo_capture(struct thread *td, siginfo_t *si) 1236{ 1237 struct thread *thr; 1238 1239 FOREACH_THREAD_IN_PROC(td->td_proc, thr) { 1240 if (thr == td) 1241 thr->td_si = *si; 1242 else 1243 thr->td_si.si_signo = 0; 1244 } 1245} 1246 1247int 1248kern_sigtimedwait(struct thread *td, sigset_t waitset, ksiginfo_t *ksi, 1249 struct timespec *timeout) 1250{ 1251 struct sigacts *ps; 1252 sigset_t saved_mask, new_block; 1253 struct proc *p; 1254 int error, sig, timo, timevalid = 0; 1255 struct timespec rts, ets, ts; 1256 struct timeval tv; 1257 bool traced; 1258 1259 p = td->td_proc; 1260 error = 0; 1261 ets.tv_sec = 0; 1262 ets.tv_nsec = 0; 1263 traced = false; 1264 1265 if (timeout != NULL) { 1266 if (timeout->tv_nsec >= 0 && timeout->tv_nsec < 1000000000) { 1267 timevalid = 1; 1268 getnanouptime(&rts); 1269 ets = rts; 1270 timespecadd(&ets, timeout); 1271 } 1272 } 1273 ksiginfo_init(ksi); 1274 /* Some signals can not be waited for. */ 1275 SIG_CANTMASK(waitset); 1276 ps = p->p_sigacts; 1277 PROC_LOCK(p); 1278 saved_mask = td->td_sigmask; 1279 SIGSETNAND(td->td_sigmask, waitset); 1280 for (;;) { 1281 mtx_lock(&ps->ps_mtx); 1282 sig = cursig(td); 1283 mtx_unlock(&ps->ps_mtx); 1284 KASSERT(sig >= 0, ("sig %d", sig)); 1285 if (sig != 0 && SIGISMEMBER(waitset, sig)) { 1286 if (sigqueue_get(&td->td_sigqueue, sig, ksi) != 0 || 1287 sigqueue_get(&p->p_sigqueue, sig, ksi) != 0) { 1288 error = 0; 1289 break; 1290 } 1291 } 1292 1293 if (error != 0) 1294 break; 1295 1296 /* 1297 * POSIX says this must be checked after looking for pending 1298 * signals. 1299 */ 1300 if (timeout != NULL) { 1301 if (!timevalid) { 1302 error = EINVAL; 1303 break; 1304 } 1305 getnanouptime(&rts); 1306 if (timespeccmp(&rts, &ets, >=)) { 1307 error = EAGAIN; 1308 break; 1309 } 1310 ts = ets; 1311 timespecsub(&ts, &rts); 1312 TIMESPEC_TO_TIMEVAL(&tv, &ts); 1313 timo = tvtohz(&tv); 1314 } else { 1315 timo = 0; 1316 } 1317 1318 if (traced) { 1319 error = EINTR; 1320 break; 1321 } 1322 1323 error = msleep(ps, &p->p_mtx, PPAUSE|PCATCH, "sigwait", timo); 1324 1325 if (timeout != NULL) { 1326 if (error == ERESTART) { 1327 /* Timeout can not be restarted. */ 1328 error = EINTR; 1329 } else if (error == EAGAIN) { 1330 /* We will calculate timeout by ourself. */ 1331 error = 0; 1332 } 1333 } 1334 1335 /* 1336 * If PTRACE_SCE or PTRACE_SCX were set after 1337 * userspace entered the syscall, return spurious 1338 * EINTR after wait was done. Only do this as last 1339 * resort after rechecking for possible queued signals 1340 * and expired timeouts. 1341 */ 1342 if (error == 0 && (p->p_ptevents & PTRACE_SYSCALL) != 0) 1343 traced = true; 1344 } 1345 1346 new_block = saved_mask; 1347 SIGSETNAND(new_block, td->td_sigmask); 1348 td->td_sigmask = saved_mask; 1349 /* 1350 * Fewer signals can be delivered to us, reschedule signal 1351 * notification. 1352 */ 1353 if (p->p_numthreads != 1) 1354 reschedule_signals(p, new_block, 0); 1355 1356 if (error == 0) { 1357 SDT_PROBE2(proc, , , signal__clear, sig, ksi); 1358 1359 if (ksi->ksi_code == SI_TIMER) 1360 itimer_accept(p, ksi->ksi_timerid, ksi); 1361 1362#ifdef KTRACE 1363 if (KTRPOINT(td, KTR_PSIG)) { 1364 sig_t action; 1365 1366 mtx_lock(&ps->ps_mtx); 1367 action = ps->ps_sigact[_SIG_IDX(sig)]; 1368 mtx_unlock(&ps->ps_mtx); 1369 ktrpsig(sig, action, &td->td_sigmask, ksi->ksi_code); 1370 } 1371#endif 1372 if (sig == SIGKILL) { 1373 proc_td_siginfo_capture(td, &ksi->ksi_info); 1374 sigexit(td, sig); 1375 } 1376 } 1377 PROC_UNLOCK(p); 1378 return (error); 1379} 1380 1381#ifndef _SYS_SYSPROTO_H_ 1382struct sigpending_args { 1383 sigset_t *set; 1384}; 1385#endif 1386int 1387sys_sigpending(struct thread *td, struct sigpending_args *uap) 1388{ 1389 struct proc *p = td->td_proc; 1390 sigset_t pending; 1391 1392 PROC_LOCK(p); 1393 pending = p->p_sigqueue.sq_signals; 1394 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1395 PROC_UNLOCK(p); 1396 return (copyout(&pending, uap->set, sizeof(sigset_t))); 1397} 1398 1399#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1400#ifndef _SYS_SYSPROTO_H_ 1401struct osigpending_args { 1402 int dummy; 1403}; 1404#endif 1405int 1406osigpending(struct thread *td, struct osigpending_args *uap) 1407{ 1408 struct proc *p = td->td_proc; 1409 sigset_t pending; 1410 1411 PROC_LOCK(p); 1412 pending = p->p_sigqueue.sq_signals; 1413 SIGSETOR(pending, td->td_sigqueue.sq_signals); 1414 PROC_UNLOCK(p); 1415 SIG2OSIG(pending, td->td_retval[0]); 1416 return (0); 1417} 1418#endif /* COMPAT_43 */ 1419 1420#if defined(COMPAT_43) 1421/* 1422 * Generalized interface signal handler, 4.3-compatible. 1423 */ 1424#ifndef _SYS_SYSPROTO_H_ 1425struct osigvec_args { 1426 int signum; 1427 struct sigvec *nsv; 1428 struct sigvec *osv; 1429}; 1430#endif 1431/* ARGSUSED */ 1432int 1433osigvec(struct thread *td, struct osigvec_args *uap) 1434{ 1435 struct sigvec vec; 1436 struct sigaction nsa, osa; 1437 struct sigaction *nsap, *osap; 1438 int error; 1439 1440 if (uap->signum <= 0 || uap->signum >= ONSIG) 1441 return (EINVAL); 1442 nsap = (uap->nsv != NULL) ? &nsa : NULL; 1443 osap = (uap->osv != NULL) ? &osa : NULL; 1444 if (nsap) { 1445 error = copyin(uap->nsv, &vec, sizeof(vec)); 1446 if (error) 1447 return (error); 1448 nsap->sa_handler = vec.sv_handler; 1449 OSIG2SIG(vec.sv_mask, nsap->sa_mask); 1450 nsap->sa_flags = vec.sv_flags; 1451 nsap->sa_flags ^= SA_RESTART; /* opposite of SV_INTERRUPT */ 1452 } 1453 error = kern_sigaction(td, uap->signum, nsap, osap, KSA_OSIGSET); 1454 if (osap && !error) { 1455 vec.sv_handler = osap->sa_handler; 1456 SIG2OSIG(osap->sa_mask, vec.sv_mask); 1457 vec.sv_flags = osap->sa_flags; 1458 vec.sv_flags &= ~SA_NOCLDWAIT; 1459 vec.sv_flags ^= SA_RESTART; 1460 error = copyout(&vec, uap->osv, sizeof(vec)); 1461 } 1462 return (error); 1463} 1464 1465#ifndef _SYS_SYSPROTO_H_ 1466struct osigblock_args { 1467 int mask; 1468}; 1469#endif 1470int 1471osigblock(struct thread *td, struct osigblock_args *uap) 1472{ 1473 sigset_t set, oset; 1474 1475 OSIG2SIG(uap->mask, set); 1476 kern_sigprocmask(td, SIG_BLOCK, &set, &oset, 0); 1477 SIG2OSIG(oset, td->td_retval[0]); 1478 return (0); 1479} 1480 1481#ifndef _SYS_SYSPROTO_H_ 1482struct osigsetmask_args { 1483 int mask; 1484}; 1485#endif 1486int 1487osigsetmask(struct thread *td, struct osigsetmask_args *uap) 1488{ 1489 sigset_t set, oset; 1490 1491 OSIG2SIG(uap->mask, set); 1492 kern_sigprocmask(td, SIG_SETMASK, &set, &oset, 0); 1493 SIG2OSIG(oset, td->td_retval[0]); 1494 return (0); 1495} 1496#endif /* COMPAT_43 */ 1497 1498/* 1499 * Suspend calling thread until signal, providing mask to be set in the 1500 * meantime. 1501 */ 1502#ifndef _SYS_SYSPROTO_H_ 1503struct sigsuspend_args { 1504 const sigset_t *sigmask; 1505}; 1506#endif 1507/* ARGSUSED */ 1508int 1509sys_sigsuspend(struct thread *td, struct sigsuspend_args *uap) 1510{ 1511 sigset_t mask; 1512 int error; 1513 1514 error = copyin(uap->sigmask, &mask, sizeof(mask)); 1515 if (error) 1516 return (error); 1517 return (kern_sigsuspend(td, mask)); 1518} 1519 1520int 1521kern_sigsuspend(struct thread *td, sigset_t mask) 1522{ 1523 struct proc *p = td->td_proc; 1524 int has_sig, sig; 1525 1526 /* 1527 * When returning from sigsuspend, we want 1528 * the old mask to be restored after the 1529 * signal handler has finished. Thus, we 1530 * save it here and mark the sigacts structure 1531 * to indicate this. 1532 */ 1533 PROC_LOCK(p); 1534 kern_sigprocmask(td, SIG_SETMASK, &mask, &td->td_oldsigmask, 1535 SIGPROCMASK_PROC_LOCKED); 1536 td->td_pflags |= TDP_OLDMASK; 1537 1538 /* 1539 * Process signals now. Otherwise, we can get spurious wakeup 1540 * due to signal entered process queue, but delivered to other 1541 * thread. But sigsuspend should return only on signal 1542 * delivery. 1543 */ 1544 (p->p_sysent->sv_set_syscall_retval)(td, EINTR); 1545 for (has_sig = 0; !has_sig;) { 1546 while (msleep(&p->p_sigacts, &p->p_mtx, PPAUSE|PCATCH, "pause", 1547 0) == 0) 1548 /* void */; 1549 thread_suspend_check(0); 1550 mtx_lock(&p->p_sigacts->ps_mtx); 1551 while ((sig = cursig(td)) != 0) { 1552 KASSERT(sig >= 0, ("sig %d", sig)); 1553 has_sig += postsig(sig); 1554 } 1555 mtx_unlock(&p->p_sigacts->ps_mtx); 1556 1557 /* 1558 * If PTRACE_SCE or PTRACE_SCX were set after 1559 * userspace entered the syscall, return spurious 1560 * EINTR. 1561 */ 1562 if ((p->p_ptevents & PTRACE_SYSCALL) != 0) 1563 has_sig += 1; 1564 } 1565 PROC_UNLOCK(p); 1566 td->td_errno = EINTR; 1567 td->td_pflags |= TDP_NERRNO; 1568 return (EJUSTRETURN); 1569} 1570 1571#ifdef COMPAT_43 /* XXX - COMPAT_FBSD3 */ 1572/* 1573 * Compatibility sigsuspend call for old binaries. Note nonstandard calling 1574 * convention: libc stub passes mask, not pointer, to save a copyin. 1575 */ 1576#ifndef _SYS_SYSPROTO_H_ 1577struct osigsuspend_args { 1578 osigset_t mask; 1579}; 1580#endif 1581/* ARGSUSED */ 1582int 1583osigsuspend(struct thread *td, struct osigsuspend_args *uap) 1584{ 1585 sigset_t mask; 1586 1587 OSIG2SIG(uap->mask, mask); 1588 return (kern_sigsuspend(td, mask)); 1589} 1590#endif /* COMPAT_43 */ 1591 1592#if defined(COMPAT_43) 1593#ifndef _SYS_SYSPROTO_H_ 1594struct osigstack_args { 1595 struct sigstack *nss; 1596 struct sigstack *oss; 1597}; 1598#endif 1599/* ARGSUSED */ 1600int 1601osigstack(struct thread *td, struct osigstack_args *uap) 1602{ 1603 struct sigstack nss, oss; 1604 int error = 0; 1605 1606 if (uap->nss != NULL) { 1607 error = copyin(uap->nss, &nss, sizeof(nss)); 1608 if (error) 1609 return (error); 1610 } 1611 oss.ss_sp = td->td_sigstk.ss_sp; 1612 oss.ss_onstack = sigonstack(cpu_getstack(td)); 1613 if (uap->nss != NULL) { 1614 td->td_sigstk.ss_sp = nss.ss_sp; 1615 td->td_sigstk.ss_size = 0; 1616 td->td_sigstk.ss_flags |= nss.ss_onstack & SS_ONSTACK; 1617 td->td_pflags |= TDP_ALTSTACK; 1618 } 1619 if (uap->oss != NULL) 1620 error = copyout(&oss, uap->oss, sizeof(oss)); 1621 1622 return (error); 1623} 1624#endif /* COMPAT_43 */ 1625 1626#ifndef _SYS_SYSPROTO_H_ 1627struct sigaltstack_args { 1628 stack_t *ss; 1629 stack_t *oss; 1630}; 1631#endif 1632/* ARGSUSED */ 1633int 1634sys_sigaltstack(struct thread *td, struct sigaltstack_args *uap) 1635{ 1636 stack_t ss, oss; 1637 int error; 1638 1639 if (uap->ss != NULL) { 1640 error = copyin(uap->ss, &ss, sizeof(ss)); 1641 if (error) 1642 return (error); 1643 } 1644 error = kern_sigaltstack(td, (uap->ss != NULL) ? &ss : NULL, 1645 (uap->oss != NULL) ? &oss : NULL); 1646 if (error) 1647 return (error); 1648 if (uap->oss != NULL) 1649 error = copyout(&oss, uap->oss, sizeof(stack_t)); 1650 return (error); 1651} 1652 1653int 1654kern_sigaltstack(struct thread *td, stack_t *ss, stack_t *oss) 1655{ 1656 struct proc *p = td->td_proc; 1657 int oonstack; 1658 1659 oonstack = sigonstack(cpu_getstack(td)); 1660 1661 if (oss != NULL) { 1662 *oss = td->td_sigstk; 1663 oss->ss_flags = (td->td_pflags & TDP_ALTSTACK) 1664 ? ((oonstack) ? SS_ONSTACK : 0) : SS_DISABLE; 1665 } 1666 1667 if (ss != NULL) { 1668 if (oonstack) 1669 return (EPERM); 1670 if ((ss->ss_flags & ~SS_DISABLE) != 0) 1671 return (EINVAL); 1672 if (!(ss->ss_flags & SS_DISABLE)) { 1673 if (ss->ss_size < p->p_sysent->sv_minsigstksz) 1674 return (ENOMEM); 1675 1676 td->td_sigstk = *ss; 1677 td->td_pflags |= TDP_ALTSTACK; 1678 } else { 1679 td->td_pflags &= ~TDP_ALTSTACK; 1680 } 1681 } 1682 return (0); 1683} 1684 1685/* 1686 * Common code for kill process group/broadcast kill. 1687 * cp is calling process. 1688 */ 1689static int 1690killpg1(struct thread *td, int sig, int pgid, int all, ksiginfo_t *ksi) 1691{ 1692 struct proc *p; 1693 struct pgrp *pgrp; 1694 int err; 1695 int ret; 1696 1697 ret = ESRCH; 1698 if (all) { 1699 /* 1700 * broadcast 1701 */ 1702 sx_slock(&allproc_lock); 1703 FOREACH_PROC_IN_SYSTEM(p) { 1704 PROC_LOCK(p); 1705 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1706 p == td->td_proc || p->p_state == PRS_NEW) { 1707 PROC_UNLOCK(p); 1708 continue; 1709 } 1710 err = p_cansignal(td, p, sig); 1711 if (err == 0) { 1712 if (sig) 1713 pksignal(p, sig, ksi); 1714 ret = err; 1715 } 1716 else if (ret == ESRCH) 1717 ret = err; 1718 PROC_UNLOCK(p); 1719 } 1720 sx_sunlock(&allproc_lock); 1721 } else { 1722 sx_slock(&proctree_lock); 1723 if (pgid == 0) { 1724 /* 1725 * zero pgid means send to my process group. 1726 */ 1727 pgrp = td->td_proc->p_pgrp; 1728 PGRP_LOCK(pgrp); 1729 } else { 1730 pgrp = pgfind(pgid); 1731 if (pgrp == NULL) { 1732 sx_sunlock(&proctree_lock); 1733 return (ESRCH); 1734 } 1735 } 1736 sx_sunlock(&proctree_lock); 1737 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1738 PROC_LOCK(p); 1739 if (p->p_pid <= 1 || p->p_flag & P_SYSTEM || 1740 p->p_state == PRS_NEW) { 1741 PROC_UNLOCK(p); 1742 continue; 1743 } 1744 err = p_cansignal(td, p, sig); 1745 if (err == 0) { 1746 if (sig) 1747 pksignal(p, sig, ksi); 1748 ret = err; 1749 } 1750 else if (ret == ESRCH) 1751 ret = err; 1752 PROC_UNLOCK(p); 1753 } 1754 PGRP_UNLOCK(pgrp); 1755 } 1756 return (ret); 1757} 1758 1759#ifndef _SYS_SYSPROTO_H_ 1760struct kill_args { 1761 int pid; 1762 int signum; 1763}; 1764#endif 1765/* ARGSUSED */ 1766int 1767sys_kill(struct thread *td, struct kill_args *uap) 1768{ 1769 ksiginfo_t ksi; 1770 struct proc *p; 1771 int error; 1772 1773 /* 1774 * A process in capability mode can send signals only to himself. 1775 * The main rationale behind this is that abort(3) is implemented as 1776 * kill(getpid(), SIGABRT). 1777 */ 1778 if (IN_CAPABILITY_MODE(td) && uap->pid != td->td_proc->p_pid) 1779 return (ECAPMODE); 1780 1781 AUDIT_ARG_SIGNUM(uap->signum); 1782 AUDIT_ARG_PID(uap->pid); 1783 if ((u_int)uap->signum > _SIG_MAXSIG) 1784 return (EINVAL); 1785 1786 ksiginfo_init(&ksi); 1787 ksi.ksi_signo = uap->signum; 1788 ksi.ksi_code = SI_USER; 1789 ksi.ksi_pid = td->td_proc->p_pid; 1790 ksi.ksi_uid = td->td_ucred->cr_ruid; 1791 1792 if (uap->pid > 0) { 1793 /* kill single process */ 1794 if ((p = pfind(uap->pid)) == NULL) { 1795 if ((p = zpfind(uap->pid)) == NULL) 1796 return (ESRCH); 1797 } 1798 AUDIT_ARG_PROCESS(p); 1799 error = p_cansignal(td, p, uap->signum); 1800 if (error == 0 && uap->signum) 1801 pksignal(p, uap->signum, &ksi); 1802 PROC_UNLOCK(p); 1803 return (error); 1804 } 1805 switch (uap->pid) { 1806 case -1: /* broadcast signal */ 1807 return (killpg1(td, uap->signum, 0, 1, &ksi)); 1808 case 0: /* signal own process group */ 1809 return (killpg1(td, uap->signum, 0, 0, &ksi)); 1810 default: /* negative explicit process group */ 1811 return (killpg1(td, uap->signum, -uap->pid, 0, &ksi)); 1812 } 1813 /* NOTREACHED */ 1814} 1815 1816int 1817sys_pdkill(struct thread *td, struct pdkill_args *uap) 1818{ 1819 struct proc *p; 1820 cap_rights_t rights; 1821 int error; 1822 1823 AUDIT_ARG_SIGNUM(uap->signum); 1824 AUDIT_ARG_FD(uap->fd); 1825 if ((u_int)uap->signum > _SIG_MAXSIG) 1826 return (EINVAL); 1827 1828 error = procdesc_find(td, uap->fd, 1829 cap_rights_init(&rights, CAP_PDKILL), &p); 1830 if (error) 1831 return (error); 1832 AUDIT_ARG_PROCESS(p); 1833 error = p_cansignal(td, p, uap->signum); 1834 if (error == 0 && uap->signum) 1835 kern_psignal(p, uap->signum); 1836 PROC_UNLOCK(p); 1837 return (error); 1838} 1839 1840#if defined(COMPAT_43) 1841#ifndef _SYS_SYSPROTO_H_ 1842struct okillpg_args { 1843 int pgid; 1844 int signum; 1845}; 1846#endif 1847/* ARGSUSED */ 1848int 1849okillpg(struct thread *td, struct okillpg_args *uap) 1850{ 1851 ksiginfo_t ksi; 1852 1853 AUDIT_ARG_SIGNUM(uap->signum); 1854 AUDIT_ARG_PID(uap->pgid); 1855 if ((u_int)uap->signum > _SIG_MAXSIG) 1856 return (EINVAL); 1857 1858 ksiginfo_init(&ksi); 1859 ksi.ksi_signo = uap->signum; 1860 ksi.ksi_code = SI_USER; 1861 ksi.ksi_pid = td->td_proc->p_pid; 1862 ksi.ksi_uid = td->td_ucred->cr_ruid; 1863 return (killpg1(td, uap->signum, uap->pgid, 0, &ksi)); 1864} 1865#endif /* COMPAT_43 */ 1866 1867#ifndef _SYS_SYSPROTO_H_ 1868struct sigqueue_args { 1869 pid_t pid; 1870 int signum; 1871 /* union sigval */ void *value; 1872}; 1873#endif 1874int 1875sys_sigqueue(struct thread *td, struct sigqueue_args *uap) 1876{ 1877 union sigval sv; 1878 1879 sv.sival_ptr = uap->value; 1880 1881 return (kern_sigqueue(td, uap->pid, uap->signum, &sv)); 1882} 1883 1884int 1885kern_sigqueue(struct thread *td, pid_t pid, int signum, union sigval *value) 1886{ 1887 ksiginfo_t ksi; 1888 struct proc *p; 1889 int error; 1890 1891 if ((u_int)signum > _SIG_MAXSIG) 1892 return (EINVAL); 1893 1894 /* 1895 * Specification says sigqueue can only send signal to 1896 * single process. 1897 */ 1898 if (pid <= 0) 1899 return (EINVAL); 1900 1901 if ((p = pfind(pid)) == NULL) { 1902 if ((p = zpfind(pid)) == NULL) 1903 return (ESRCH); 1904 } 1905 error = p_cansignal(td, p, signum); 1906 if (error == 0 && signum != 0) { 1907 ksiginfo_init(&ksi); 1908 ksi.ksi_flags = KSI_SIGQ; 1909 ksi.ksi_signo = signum; 1910 ksi.ksi_code = SI_QUEUE; 1911 ksi.ksi_pid = td->td_proc->p_pid; 1912 ksi.ksi_uid = td->td_ucred->cr_ruid; 1913 ksi.ksi_value = *value; 1914 error = pksignal(p, ksi.ksi_signo, &ksi); 1915 } 1916 PROC_UNLOCK(p); 1917 return (error); 1918} 1919 1920/* 1921 * Send a signal to a process group. 1922 */ 1923void 1924gsignal(int pgid, int sig, ksiginfo_t *ksi) 1925{ 1926 struct pgrp *pgrp; 1927 1928 if (pgid != 0) { 1929 sx_slock(&proctree_lock); 1930 pgrp = pgfind(pgid); 1931 sx_sunlock(&proctree_lock); 1932 if (pgrp != NULL) { 1933 pgsignal(pgrp, sig, 0, ksi); 1934 PGRP_UNLOCK(pgrp); 1935 } 1936 } 1937} 1938 1939/* 1940 * Send a signal to a process group. If checktty is 1, 1941 * limit to members which have a controlling terminal. 1942 */ 1943void 1944pgsignal(struct pgrp *pgrp, int sig, int checkctty, ksiginfo_t *ksi) 1945{ 1946 struct proc *p; 1947 1948 if (pgrp) { 1949 PGRP_LOCK_ASSERT(pgrp, MA_OWNED); 1950 LIST_FOREACH(p, &pgrp->pg_members, p_pglist) { 1951 PROC_LOCK(p); 1952 if (p->p_state == PRS_NORMAL && 1953 (checkctty == 0 || p->p_flag & P_CONTROLT)) 1954 pksignal(p, sig, ksi); 1955 PROC_UNLOCK(p); 1956 } 1957 } 1958} 1959 1960 1961/* 1962 * Recalculate the signal mask and reset the signal disposition after 1963 * usermode frame for delivery is formed. Should be called after 1964 * mach-specific routine, because sysent->sv_sendsig() needs correct 1965 * ps_siginfo and signal mask. 1966 */ 1967static void 1968postsig_done(int sig, struct thread *td, struct sigacts *ps) 1969{ 1970 sigset_t mask; 1971 1972 mtx_assert(&ps->ps_mtx, MA_OWNED); 1973 td->td_ru.ru_nsignals++; 1974 mask = ps->ps_catchmask[_SIG_IDX(sig)]; 1975 if (!SIGISMEMBER(ps->ps_signodefer, sig)) 1976 SIGADDSET(mask, sig); 1977 kern_sigprocmask(td, SIG_BLOCK, &mask, NULL, 1978 SIGPROCMASK_PROC_LOCKED | SIGPROCMASK_PS_LOCKED); 1979 if (SIGISMEMBER(ps->ps_sigreset, sig)) 1980 sigdflt(ps, sig); 1981} 1982 1983 1984/* 1985 * Send a signal caused by a trap to the current thread. If it will be 1986 * caught immediately, deliver it with correct code. Otherwise, post it 1987 * normally. 1988 */ 1989void 1990trapsignal(struct thread *td, ksiginfo_t *ksi) 1991{ 1992 struct sigacts *ps; 1993 struct proc *p; 1994 int sig; 1995 int code; 1996 1997 p = td->td_proc; 1998 sig = ksi->ksi_signo; 1999 code = ksi->ksi_code; 2000 KASSERT(_SIG_VALID(sig), ("invalid signal")); 2001 2002 PROC_LOCK(p); 2003 ps = p->p_sigacts; 2004 mtx_lock(&ps->ps_mtx); 2005 if ((p->p_flag & P_TRACED) == 0 && SIGISMEMBER(ps->ps_sigcatch, sig) && 2006 !SIGISMEMBER(td->td_sigmask, sig)) { 2007#ifdef KTRACE 2008 if (KTRPOINT(curthread, KTR_PSIG)) 2009 ktrpsig(sig, ps->ps_sigact[_SIG_IDX(sig)], 2010 &td->td_sigmask, code); 2011#endif 2012 (*p->p_sysent->sv_sendsig)(ps->ps_sigact[_SIG_IDX(sig)], 2013 ksi, &td->td_sigmask); 2014 postsig_done(sig, td, ps); 2015 mtx_unlock(&ps->ps_mtx); 2016 } else { 2017 /* 2018 * Avoid a possible infinite loop if the thread 2019 * masking the signal or process is ignoring the 2020 * signal. 2021 */ 2022 if (kern_forcesigexit && 2023 (SIGISMEMBER(td->td_sigmask, sig) || 2024 ps->ps_sigact[_SIG_IDX(sig)] == SIG_IGN)) { 2025 SIGDELSET(td->td_sigmask, sig); 2026 SIGDELSET(ps->ps_sigcatch, sig); 2027 SIGDELSET(ps->ps_sigignore, sig); 2028 ps->ps_sigact[_SIG_IDX(sig)] = SIG_DFL; 2029 } 2030 mtx_unlock(&ps->ps_mtx); 2031 p->p_code = code; /* XXX for core dump/debugger */ 2032 p->p_sig = sig; /* XXX to verify code */ 2033 tdsendsignal(p, td, sig, ksi); 2034 } 2035 PROC_UNLOCK(p); 2036} 2037 2038static struct thread * 2039sigtd(struct proc *p, int sig, int prop) 2040{ 2041 struct thread *td, *signal_td; 2042 2043 PROC_LOCK_ASSERT(p, MA_OWNED); 2044 2045 /* 2046 * Check if current thread can handle the signal without 2047 * switching context to another thread. 2048 */ 2049 if (curproc == p && !SIGISMEMBER(curthread->td_sigmask, sig)) 2050 return (curthread); 2051 signal_td = NULL; 2052 FOREACH_THREAD_IN_PROC(p, td) { 2053 if (!SIGISMEMBER(td->td_sigmask, sig)) { 2054 signal_td = td; 2055 break; 2056 } 2057 } 2058 if (signal_td == NULL) 2059 signal_td = FIRST_THREAD_IN_PROC(p); 2060 return (signal_td); 2061} 2062 2063/* 2064 * Send the signal to the process. If the signal has an action, the action 2065 * is usually performed by the target process rather than the caller; we add 2066 * the signal to the set of pending signals for the process. 2067 * 2068 * Exceptions: 2069 * o When a stop signal is sent to a sleeping process that takes the 2070 * default action, the process is stopped without awakening it. 2071 * o SIGCONT restarts stopped processes (or puts them back to sleep) 2072 * regardless of the signal action (eg, blocked or ignored). 2073 * 2074 * Other ignored signals are discarded immediately. 2075 * 2076 * NB: This function may be entered from the debugger via the "kill" DDB 2077 * command. There is little that can be done to mitigate the possibly messy 2078 * side effects of this unwise possibility. 2079 */ 2080void 2081kern_psignal(struct proc *p, int sig) 2082{ 2083 ksiginfo_t ksi; 2084 2085 ksiginfo_init(&ksi); 2086 ksi.ksi_signo = sig; 2087 ksi.ksi_code = SI_KERNEL; 2088 (void) tdsendsignal(p, NULL, sig, &ksi); 2089} 2090 2091int 2092pksignal(struct proc *p, int sig, ksiginfo_t *ksi) 2093{ 2094 2095 return (tdsendsignal(p, NULL, sig, ksi)); 2096} 2097 2098/* Utility function for finding a thread to send signal event to. */ 2099int 2100sigev_findtd(struct proc *p ,struct sigevent *sigev, struct thread **ttd) 2101{ 2102 struct thread *td; 2103 2104 if (sigev->sigev_notify == SIGEV_THREAD_ID) { 2105 td = tdfind(sigev->sigev_notify_thread_id, p->p_pid); 2106 if (td == NULL) 2107 return (ESRCH); 2108 *ttd = td; 2109 } else { 2110 *ttd = NULL; 2111 PROC_LOCK(p); 2112 } 2113 return (0); 2114} 2115 2116void 2117tdsignal(struct thread *td, int sig) 2118{ 2119 ksiginfo_t ksi; 2120 2121 ksiginfo_init(&ksi); 2122 ksi.ksi_signo = sig; 2123 ksi.ksi_code = SI_KERNEL; 2124 (void) tdsendsignal(td->td_proc, td, sig, &ksi); 2125} 2126 2127void 2128tdksignal(struct thread *td, int sig, ksiginfo_t *ksi) 2129{ 2130 2131 (void) tdsendsignal(td->td_proc, td, sig, ksi); 2132} 2133 2134int 2135tdsendsignal(struct proc *p, struct thread *td, int sig, ksiginfo_t *ksi) 2136{ 2137 sig_t action; 2138 sigqueue_t *sigqueue; 2139 int prop; 2140 struct sigacts *ps; 2141 int intrval; 2142 int ret = 0; 2143 int wakeup_swapper; 2144 2145 MPASS(td == NULL || p == td->td_proc); 2146 PROC_LOCK_ASSERT(p, MA_OWNED); 2147 2148 if (!_SIG_VALID(sig)) 2149 panic("%s(): invalid signal %d", __func__, sig); 2150 2151 KASSERT(ksi == NULL || !KSI_ONQ(ksi), ("%s: ksi on queue", __func__)); 2152 2153 /* 2154 * IEEE Std 1003.1-2001: return success when killing a zombie. 2155 */ 2156 if (p->p_state == PRS_ZOMBIE) { 2157 if (ksi && (ksi->ksi_flags & KSI_INS)) 2158 ksiginfo_tryfree(ksi); 2159 return (ret); 2160 } 2161 2162 ps = p->p_sigacts; 2163 KNOTE_LOCKED(p->p_klist, NOTE_SIGNAL | sig); 2164 prop = sigprop(sig); 2165 2166 if (td == NULL) { 2167 td = sigtd(p, sig, prop); 2168 sigqueue = &p->p_sigqueue; 2169 } else 2170 sigqueue = &td->td_sigqueue; 2171 2172 SDT_PROBE3(proc, , , signal__send, td, p, sig); 2173 2174 /* 2175 * If the signal is being ignored, 2176 * then we forget about it immediately. 2177 * (Note: we don't set SIGCONT in ps_sigignore, 2178 * and if it is set to SIG_IGN, 2179 * action will be SIG_DFL here.) 2180 */ 2181 mtx_lock(&ps->ps_mtx); 2182 if (SIGISMEMBER(ps->ps_sigignore, sig)) { 2183 SDT_PROBE3(proc, , , signal__discard, td, p, sig); 2184 2185 mtx_unlock(&ps->ps_mtx); 2186 if (ksi && (ksi->ksi_flags & KSI_INS)) 2187 ksiginfo_tryfree(ksi); 2188 return (ret); 2189 } 2190 if (SIGISMEMBER(td->td_sigmask, sig)) 2191 action = SIG_HOLD; 2192 else if (SIGISMEMBER(ps->ps_sigcatch, sig)) 2193 action = SIG_CATCH; 2194 else 2195 action = SIG_DFL; 2196 if (SIGISMEMBER(ps->ps_sigintr, sig)) 2197 intrval = EINTR; 2198 else 2199 intrval = ERESTART; 2200 mtx_unlock(&ps->ps_mtx); 2201 2202 if (prop & SA_CONT) 2203 sigqueue_delete_stopmask_proc(p); 2204 else if (prop & SA_STOP) { 2205 /* 2206 * If sending a tty stop signal to a member of an orphaned 2207 * process group, discard the signal here if the action 2208 * is default; don't stop the process below if sleeping, 2209 * and don't clear any pending SIGCONT. 2210 */ 2211 if ((prop & SA_TTYSTOP) && 2212 (p->p_pgrp->pg_jobc == 0) && 2213 (action == SIG_DFL)) { 2214 if (ksi && (ksi->ksi_flags & KSI_INS)) 2215 ksiginfo_tryfree(ksi); 2216 return (ret); 2217 } 2218 sigqueue_delete_proc(p, SIGCONT); 2219 if (p->p_flag & P_CONTINUED) { 2220 p->p_flag &= ~P_CONTINUED; 2221 PROC_LOCK(p->p_pptr); 2222 sigqueue_take(p->p_ksi); 2223 PROC_UNLOCK(p->p_pptr); 2224 } 2225 } 2226 2227 ret = sigqueue_add(sigqueue, sig, ksi); 2228 if (ret != 0) 2229 return (ret); 2230 signotify(td); 2231 /* 2232 * Defer further processing for signals which are held, 2233 * except that stopped processes must be continued by SIGCONT. 2234 */ 2235 if (action == SIG_HOLD && 2236 !((prop & SA_CONT) && (p->p_flag & P_STOPPED_SIG))) 2237 return (ret); 2238 2239 /* SIGKILL: Remove procfs STOPEVENTs. */ 2240 if (sig == SIGKILL) { 2241 /* from procfs_ioctl.c: PIOCBIC */ 2242 p->p_stops = 0; 2243 /* from procfs_ioctl.c: PIOCCONT */ 2244 p->p_step = 0; 2245 wakeup(&p->p_step); 2246 } 2247 /* 2248 * Some signals have a process-wide effect and a per-thread 2249 * component. Most processing occurs when the process next 2250 * tries to cross the user boundary, however there are some 2251 * times when processing needs to be done immediately, such as 2252 * waking up threads so that they can cross the user boundary. 2253 * We try to do the per-process part here. 2254 */ 2255 if (P_SHOULDSTOP(p)) { 2256 KASSERT(!(p->p_flag & P_WEXIT), 2257 ("signal to stopped but exiting process")); 2258 if (sig == SIGKILL) { 2259 /* 2260 * If traced process is already stopped, 2261 * then no further action is necessary. 2262 */ 2263 if (p->p_flag & P_TRACED) 2264 goto out; 2265 /* 2266 * SIGKILL sets process running. 2267 * It will die elsewhere. 2268 * All threads must be restarted. 2269 */ 2270 p->p_flag &= ~P_STOPPED_SIG; 2271 goto runfast; 2272 } 2273 2274 if (prop & SA_CONT) { 2275 /* 2276 * If traced process is already stopped, 2277 * then no further action is necessary. 2278 */ 2279 if (p->p_flag & P_TRACED) 2280 goto out; 2281 /* 2282 * If SIGCONT is default (or ignored), we continue the 2283 * process but don't leave the signal in sigqueue as 2284 * it has no further action. If SIGCONT is held, we 2285 * continue the process and leave the signal in 2286 * sigqueue. If the process catches SIGCONT, let it 2287 * handle the signal itself. If it isn't waiting on 2288 * an event, it goes back to run state. 2289 * Otherwise, process goes back to sleep state. 2290 */ 2291 p->p_flag &= ~P_STOPPED_SIG; 2292 PROC_SLOCK(p); 2293 if (p->p_numthreads == p->p_suspcount) { 2294 PROC_SUNLOCK(p); 2295 p->p_flag |= P_CONTINUED; 2296 p->p_xsig = SIGCONT; 2297 PROC_LOCK(p->p_pptr); 2298 childproc_continued(p); 2299 PROC_UNLOCK(p->p_pptr); 2300 PROC_SLOCK(p); 2301 } 2302 if (action == SIG_DFL) { 2303 thread_unsuspend(p); 2304 PROC_SUNLOCK(p); 2305 sigqueue_delete(sigqueue, sig); 2306 goto out; 2307 } 2308 if (action == SIG_CATCH) { 2309 /* 2310 * The process wants to catch it so it needs 2311 * to run at least one thread, but which one? 2312 */ 2313 PROC_SUNLOCK(p); 2314 goto runfast; 2315 } 2316 /* 2317 * The signal is not ignored or caught. 2318 */ 2319 thread_unsuspend(p); 2320 PROC_SUNLOCK(p); 2321 goto out; 2322 } 2323 2324 if (prop & SA_STOP) { 2325 /* 2326 * If traced process is already stopped, 2327 * then no further action is necessary. 2328 */ 2329 if (p->p_flag & P_TRACED) 2330 goto out; 2331 /* 2332 * Already stopped, don't need to stop again 2333 * (If we did the shell could get confused). 2334 * Just make sure the signal STOP bit set. 2335 */ 2336 p->p_flag |= P_STOPPED_SIG; 2337 sigqueue_delete(sigqueue, sig); 2338 goto out; 2339 } 2340 2341 /* 2342 * All other kinds of signals: 2343 * If a thread is sleeping interruptibly, simulate a 2344 * wakeup so that when it is continued it will be made 2345 * runnable and can look at the signal. However, don't make 2346 * the PROCESS runnable, leave it stopped. 2347 * It may run a bit until it hits a thread_suspend_check(). 2348 */ 2349 wakeup_swapper = 0; 2350 PROC_SLOCK(p); 2351 thread_lock(td); 2352 if (TD_ON_SLEEPQ(td) && (td->td_flags & TDF_SINTR)) 2353 wakeup_swapper = sleepq_abort(td, intrval); 2354 thread_unlock(td); 2355 PROC_SUNLOCK(p); 2356 if (wakeup_swapper) 2357 kick_proc0(); 2358 goto out; 2359 /* 2360 * Mutexes are short lived. Threads waiting on them will 2361 * hit thread_suspend_check() soon. 2362 */ 2363 } else if (p->p_state == PRS_NORMAL) { 2364 if (p->p_flag & P_TRACED || action == SIG_CATCH) { 2365 tdsigwakeup(td, sig, action, intrval); 2366 goto out; 2367 } 2368 2369 MPASS(action == SIG_DFL); 2370 2371 if (prop & SA_STOP) { 2372 if (p->p_flag & (P_PPWAIT|P_WEXIT)) 2373 goto out; 2374 p->p_flag |= P_STOPPED_SIG; 2375 p->p_xsig = sig; 2376 PROC_SLOCK(p); 2377 wakeup_swapper = sig_suspend_threads(td, p, 1); 2378 if (p->p_numthreads == p->p_suspcount) { 2379 /* 2380 * only thread sending signal to another 2381 * process can reach here, if thread is sending 2382 * signal to its process, because thread does 2383 * not suspend itself here, p_numthreads 2384 * should never be equal to p_suspcount. 2385 */ 2386 thread_stopped(p); 2387 PROC_SUNLOCK(p); 2388 sigqueue_delete_proc(p, p->p_xsig); 2389 } else 2390 PROC_SUNLOCK(p); 2391 if (wakeup_swapper) 2392 kick_proc0(); 2393 goto out; 2394 } 2395 } else { 2396 /* Not in "NORMAL" state. discard the signal. */ 2397 sigqueue_delete(sigqueue, sig); 2398 goto out; 2399 } 2400 2401 /* 2402 * The process is not stopped so we need to apply the signal to all the 2403 * running threads. 2404 */ 2405runfast: 2406 tdsigwakeup(td, sig, action, intrval); 2407 PROC_SLOCK(p); 2408 thread_unsuspend(p); 2409 PROC_SUNLOCK(p); 2410out: 2411 /* If we jump here, proc slock should not be owned. */ 2412 PROC_SLOCK_ASSERT(p, MA_NOTOWNED); 2413 return (ret); 2414} 2415 2416/* 2417 * The force of a signal has been directed against a single 2418 * thread. We need to see what we can do about knocking it 2419 * out of any sleep it may be in etc. 2420 */ 2421static void 2422tdsigwakeup(struct thread *td, int sig, sig_t action, int intrval) 2423{ 2424 struct proc *p = td->td_proc; 2425 int prop; 2426 int wakeup_swapper; 2427 2428 wakeup_swapper = 0; 2429 PROC_LOCK_ASSERT(p, MA_OWNED); 2430 prop = sigprop(sig); 2431 2432 PROC_SLOCK(p); 2433 thread_lock(td); 2434 /* 2435 * Bring the priority of a thread up if we want it to get 2436 * killed in this lifetime. Be careful to avoid bumping the 2437 * priority of the idle thread, since we still allow to signal 2438 * kernel processes. 2439 */ 2440 if (action == SIG_DFL && (prop & SA_KILL) != 0 && 2441 td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2442 sched_prio(td, PUSER); 2443 if (TD_ON_SLEEPQ(td)) { 2444 /* 2445 * If thread is sleeping uninterruptibly 2446 * we can't interrupt the sleep... the signal will 2447 * be noticed when the process returns through 2448 * trap() or syscall(). 2449 */ 2450 if ((td->td_flags & TDF_SINTR) == 0) 2451 goto out; 2452 /* 2453 * If SIGCONT is default (or ignored) and process is 2454 * asleep, we are finished; the process should not 2455 * be awakened. 2456 */ 2457 if ((prop & SA_CONT) && action == SIG_DFL) { 2458 thread_unlock(td); 2459 PROC_SUNLOCK(p); 2460 sigqueue_delete(&p->p_sigqueue, sig); 2461 /* 2462 * It may be on either list in this state. 2463 * Remove from both for now. 2464 */ 2465 sigqueue_delete(&td->td_sigqueue, sig); 2466 return; 2467 } 2468 2469 /* 2470 * Don't awaken a sleeping thread for SIGSTOP if the 2471 * STOP signal is deferred. 2472 */ 2473 if ((prop & SA_STOP) != 0 && (td->td_flags & (TDF_SBDRY | 2474 TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2475 goto out; 2476 2477 /* 2478 * Give low priority threads a better chance to run. 2479 */ 2480 if (td->td_priority > PUSER && !TD_IS_IDLETHREAD(td)) 2481 sched_prio(td, PUSER); 2482 2483 wakeup_swapper = sleepq_abort(td, intrval); 2484 } else { 2485 /* 2486 * Other states do nothing with the signal immediately, 2487 * other than kicking ourselves if we are running. 2488 * It will either never be noticed, or noticed very soon. 2489 */ 2490#ifdef SMP 2491 if (TD_IS_RUNNING(td) && td != curthread) 2492 forward_signal(td); 2493#endif 2494 } 2495out: 2496 PROC_SUNLOCK(p); 2497 thread_unlock(td); 2498 if (wakeup_swapper) 2499 kick_proc0(); 2500} 2501 2502static int 2503sig_suspend_threads(struct thread *td, struct proc *p, int sending) 2504{ 2505 struct thread *td2; 2506 int wakeup_swapper; 2507 2508 PROC_LOCK_ASSERT(p, MA_OWNED); 2509 PROC_SLOCK_ASSERT(p, MA_OWNED); 2510 MPASS(sending || td == curthread); 2511 2512 wakeup_swapper = 0; 2513 FOREACH_THREAD_IN_PROC(p, td2) { 2514 thread_lock(td2); 2515 td2->td_flags |= TDF_ASTPENDING | TDF_NEEDSUSPCHK; 2516 if ((TD_IS_SLEEPING(td2) || TD_IS_SWAPPED(td2)) && 2517 (td2->td_flags & TDF_SINTR)) { 2518 if (td2->td_flags & TDF_SBDRY) { 2519 /* 2520 * Once a thread is asleep with 2521 * TDF_SBDRY and without TDF_SERESTART 2522 * or TDF_SEINTR set, it should never 2523 * become suspended due to this check. 2524 */ 2525 KASSERT(!TD_IS_SUSPENDED(td2), 2526 ("thread with deferred stops suspended")); 2527 if (TD_SBDRY_INTR(td2)) 2528 wakeup_swapper |= sleepq_abort(td2, 2529 TD_SBDRY_ERRNO(td2)); 2530 } else if (!TD_IS_SUSPENDED(td2)) { 2531 thread_suspend_one(td2); 2532 } 2533 } else if (!TD_IS_SUSPENDED(td2)) { 2534 if (sending || td != td2) 2535 td2->td_flags |= TDF_ASTPENDING; 2536#ifdef SMP 2537 if (TD_IS_RUNNING(td2) && td2 != td) 2538 forward_signal(td2); 2539#endif 2540 } 2541 thread_unlock(td2); 2542 } 2543 return (wakeup_swapper); 2544} 2545 2546/* 2547 * Stop the process for an event deemed interesting to the debugger. If si is 2548 * non-NULL, this is a signal exchange; the new signal requested by the 2549 * debugger will be returned for handling. If si is NULL, this is some other 2550 * type of interesting event. The debugger may request a signal be delivered in 2551 * that case as well, however it will be deferred until it can be handled. 2552 */ 2553int 2554ptracestop(struct thread *td, int sig, ksiginfo_t *si) 2555{ 2556 struct proc *p = td->td_proc; 2557 struct thread *td2; 2558 ksiginfo_t ksi; 2559 int prop; 2560 2561 PROC_LOCK_ASSERT(p, MA_OWNED); 2562 KASSERT(!(p->p_flag & P_WEXIT), ("Stopping exiting process")); 2563 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2564 &p->p_mtx.lock_object, "Stopping for traced signal"); 2565 2566 td->td_xsig = sig; 2567 2568 if (si == NULL || (si->ksi_flags & KSI_PTRACE) == 0) { 2569 td->td_dbgflags |= TDB_XSIG; 2570 CTR4(KTR_PTRACE, "ptracestop: tid %d (pid %d) flags %#x sig %d", 2571 td->td_tid, p->p_pid, td->td_dbgflags, sig); 2572 PROC_SLOCK(p); 2573 while ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_XSIG)) { 2574 if (P_KILLED(p)) { 2575 /* 2576 * Ensure that, if we've been PT_KILLed, the 2577 * exit status reflects that. Another thread 2578 * may also be in ptracestop(), having just 2579 * received the SIGKILL, but this thread was 2580 * unsuspended first. 2581 */ 2582 td->td_dbgflags &= ~TDB_XSIG; 2583 td->td_xsig = SIGKILL; 2584 p->p_ptevents = 0; 2585 break; 2586 } 2587 if (p->p_flag & P_SINGLE_EXIT && 2588 !(td->td_dbgflags & TDB_EXIT)) { 2589 /* 2590 * Ignore ptrace stops except for thread exit 2591 * events when the process exits. 2592 */ 2593 td->td_dbgflags &= ~TDB_XSIG; 2594 PROC_SUNLOCK(p); 2595 return (0); 2596 } 2597 2598 /* 2599 * Make wait(2) work. Ensure that right after the 2600 * attach, the thread which was decided to become the 2601 * leader of attach gets reported to the waiter. 2602 * Otherwise, just avoid overwriting another thread's 2603 * assignment to p_xthread. If another thread has 2604 * already set p_xthread, the current thread will get 2605 * a chance to report itself upon the next iteration. 2606 */ 2607 if ((td->td_dbgflags & TDB_FSTP) != 0 || 2608 ((p->p_flag2 & P2_PTRACE_FSTP) == 0 && 2609 p->p_xthread == NULL)) { 2610 p->p_xsig = sig; 2611 p->p_xthread = td; 2612 2613 /* 2614 * If we are on sleepqueue already, 2615 * let sleepqueue code decide if it 2616 * needs to go sleep after attach. 2617 */ 2618 if (td->td_wchan == NULL) 2619 td->td_dbgflags &= ~TDB_FSTP; 2620 2621 p->p_flag2 &= ~P2_PTRACE_FSTP; 2622 p->p_flag |= P_STOPPED_SIG | P_STOPPED_TRACE; 2623 sig_suspend_threads(td, p, 0); 2624 } 2625 if ((td->td_dbgflags & TDB_STOPATFORK) != 0) { 2626 td->td_dbgflags &= ~TDB_STOPATFORK; 2627 } 2628stopme: 2629 thread_suspend_switch(td, p); 2630 if (p->p_xthread == td) 2631 p->p_xthread = NULL; 2632 if (!(p->p_flag & P_TRACED)) 2633 break; 2634 if (td->td_dbgflags & TDB_SUSPEND) { 2635 if (p->p_flag & P_SINGLE_EXIT) 2636 break; 2637 goto stopme; 2638 } 2639 } 2640 PROC_SUNLOCK(p); 2641 } 2642 2643 if (si != NULL && sig == td->td_xsig) { 2644 /* Parent wants us to take the original signal unchanged. */ 2645 si->ksi_flags |= KSI_HEAD; 2646 if (sigqueue_add(&td->td_sigqueue, sig, si) != 0) 2647 si->ksi_signo = 0; 2648 } else if (td->td_xsig != 0) { 2649 /* 2650 * If parent wants us to take a new signal, then it will leave 2651 * it in td->td_xsig; otherwise we just look for signals again. 2652 */ 2653 ksiginfo_init(&ksi); 2654 ksi.ksi_signo = td->td_xsig; 2655 ksi.ksi_flags |= KSI_PTRACE; 2656 prop = sigprop(td->td_xsig); 2657 td2 = sigtd(p, td->td_xsig, prop); 2658 tdsendsignal(p, td2, td->td_xsig, &ksi); 2659 if (td != td2) 2660 return (0); 2661 } 2662 2663 return (td->td_xsig); 2664} 2665 2666static void 2667reschedule_signals(struct proc *p, sigset_t block, int flags) 2668{ 2669 struct sigacts *ps; 2670 struct thread *td; 2671 int sig; 2672 2673 PROC_LOCK_ASSERT(p, MA_OWNED); 2674 ps = p->p_sigacts; 2675 mtx_assert(&ps->ps_mtx, (flags & SIGPROCMASK_PS_LOCKED) != 0 ? 2676 MA_OWNED : MA_NOTOWNED); 2677 if (SIGISEMPTY(p->p_siglist)) 2678 return; 2679 SIGSETAND(block, p->p_siglist); 2680 while ((sig = sig_ffs(&block)) != 0) { 2681 SIGDELSET(block, sig); 2682 td = sigtd(p, sig, 0); 2683 signotify(td); 2684 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2685 mtx_lock(&ps->ps_mtx); 2686 if (p->p_flag & P_TRACED || 2687 (SIGISMEMBER(ps->ps_sigcatch, sig) && 2688 !SIGISMEMBER(td->td_sigmask, sig))) 2689 tdsigwakeup(td, sig, SIG_CATCH, 2690 (SIGISMEMBER(ps->ps_sigintr, sig) ? EINTR : 2691 ERESTART)); 2692 if (!(flags & SIGPROCMASK_PS_LOCKED)) 2693 mtx_unlock(&ps->ps_mtx); 2694 } 2695} 2696 2697void 2698tdsigcleanup(struct thread *td) 2699{ 2700 struct proc *p; 2701 sigset_t unblocked; 2702 2703 p = td->td_proc; 2704 PROC_LOCK_ASSERT(p, MA_OWNED); 2705 2706 sigqueue_flush(&td->td_sigqueue); 2707 if (p->p_numthreads == 1) 2708 return; 2709 2710 /* 2711 * Since we cannot handle signals, notify signal post code 2712 * about this by filling the sigmask. 2713 * 2714 * Also, if needed, wake up thread(s) that do not block the 2715 * same signals as the exiting thread, since the thread might 2716 * have been selected for delivery and woken up. 2717 */ 2718 SIGFILLSET(unblocked); 2719 SIGSETNAND(unblocked, td->td_sigmask); 2720 SIGFILLSET(td->td_sigmask); 2721 reschedule_signals(p, unblocked, 0); 2722 2723} 2724 2725static int 2726sigdeferstop_curr_flags(int cflags) 2727{ 2728 2729 MPASS((cflags & (TDF_SEINTR | TDF_SERESTART)) == 0 || 2730 (cflags & TDF_SBDRY) != 0); 2731 return (cflags & (TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)); 2732} 2733 2734/* 2735 * Defer the delivery of SIGSTOP for the current thread, according to 2736 * the requested mode. Returns previous flags, which must be restored 2737 * by sigallowstop(). 2738 * 2739 * TDF_SBDRY, TDF_SEINTR, and TDF_SERESTART flags are only set and 2740 * cleared by the current thread, which allow the lock-less read-only 2741 * accesses below. 2742 */ 2743int 2744sigdeferstop_impl(int mode) 2745{ 2746 struct thread *td; 2747 int cflags, nflags; 2748 2749 td = curthread; 2750 cflags = sigdeferstop_curr_flags(td->td_flags); 2751 switch (mode) { 2752 case SIGDEFERSTOP_NOP: 2753 nflags = cflags; 2754 break; 2755 case SIGDEFERSTOP_OFF: 2756 nflags = 0; 2757 break; 2758 case SIGDEFERSTOP_SILENT: 2759 nflags = (cflags | TDF_SBDRY) & ~(TDF_SEINTR | TDF_SERESTART); 2760 break; 2761 case SIGDEFERSTOP_EINTR: 2762 nflags = (cflags | TDF_SBDRY | TDF_SEINTR) & ~TDF_SERESTART; 2763 break; 2764 case SIGDEFERSTOP_ERESTART: 2765 nflags = (cflags | TDF_SBDRY | TDF_SERESTART) & ~TDF_SEINTR; 2766 break; 2767 default: 2768 panic("sigdeferstop: invalid mode %x", mode); 2769 break; 2770 } 2771 if (cflags == nflags) 2772 return (SIGDEFERSTOP_VAL_NCHG); 2773 thread_lock(td); 2774 td->td_flags = (td->td_flags & ~cflags) | nflags; 2775 thread_unlock(td); 2776 return (cflags); 2777} 2778 2779/* 2780 * Restores the STOP handling mode, typically permitting the delivery 2781 * of SIGSTOP for the current thread. This does not immediately 2782 * suspend if a stop was posted. Instead, the thread will suspend 2783 * either via ast() or a subsequent interruptible sleep. 2784 */ 2785void 2786sigallowstop_impl(int prev) 2787{ 2788 struct thread *td; 2789 int cflags; 2790 2791 KASSERT(prev != SIGDEFERSTOP_VAL_NCHG, ("failed sigallowstop")); 2792 KASSERT((prev & ~(TDF_SBDRY | TDF_SEINTR | TDF_SERESTART)) == 0, 2793 ("sigallowstop: incorrect previous mode %x", prev)); 2794 td = curthread; 2795 cflags = sigdeferstop_curr_flags(td->td_flags); 2796 if (cflags != prev) { 2797 thread_lock(td); 2798 td->td_flags = (td->td_flags & ~cflags) | prev; 2799 thread_unlock(td); 2800 } 2801} 2802 2803/* 2804 * If the current process has received a signal (should be caught or cause 2805 * termination, should interrupt current syscall), return the signal number. 2806 * Stop signals with default action are processed immediately, then cleared; 2807 * they aren't returned. This is checked after each entry to the system for 2808 * a syscall or trap (though this can usually be done without calling issignal 2809 * by checking the pending signal masks in cursig.) The normal call 2810 * sequence is 2811 * 2812 * while (sig = cursig(curthread)) 2813 * postsig(sig); 2814 */ 2815static int 2816issignal(struct thread *td) 2817{ 2818 struct proc *p; 2819 struct sigacts *ps; 2820 struct sigqueue *queue; 2821 sigset_t sigpending; 2822 int prop, sig, traced; 2823 ksiginfo_t ksi; 2824 2825 p = td->td_proc; 2826 ps = p->p_sigacts; 2827 mtx_assert(&ps->ps_mtx, MA_OWNED); 2828 PROC_LOCK_ASSERT(p, MA_OWNED); 2829 for (;;) { 2830 traced = (p->p_flag & P_TRACED) || (p->p_stops & S_SIG); 2831 2832 sigpending = td->td_sigqueue.sq_signals; 2833 SIGSETOR(sigpending, p->p_sigqueue.sq_signals); 2834 SIGSETNAND(sigpending, td->td_sigmask); 2835 2836 if ((p->p_flag & P_PPWAIT) != 0 || (td->td_flags & 2837 (TDF_SBDRY | TDF_SERESTART | TDF_SEINTR)) == TDF_SBDRY) 2838 SIG_STOPSIGMASK(sigpending); 2839 if (SIGISEMPTY(sigpending)) /* no signal to send */ 2840 return (0); 2841 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED && 2842 (p->p_flag2 & P2_PTRACE_FSTP) != 0 && 2843 SIGISMEMBER(sigpending, SIGSTOP)) { 2844 /* 2845 * If debugger just attached, always consume 2846 * SIGSTOP from ptrace(PT_ATTACH) first, to 2847 * execute the debugger attach ritual in 2848 * order. 2849 */ 2850 sig = SIGSTOP; 2851 td->td_dbgflags |= TDB_FSTP; 2852 } else { 2853 sig = sig_ffs(&sigpending); 2854 } 2855 2856 if (p->p_stops & S_SIG) { 2857 mtx_unlock(&ps->ps_mtx); 2858 stopevent(p, S_SIG, sig); 2859 mtx_lock(&ps->ps_mtx); 2860 } 2861 2862 /* 2863 * We should see pending but ignored signals 2864 * only if P_TRACED was on when they were posted. 2865 */ 2866 if (SIGISMEMBER(ps->ps_sigignore, sig) && (traced == 0)) { 2867 sigqueue_delete(&td->td_sigqueue, sig); 2868 sigqueue_delete(&p->p_sigqueue, sig); 2869 continue; 2870 } 2871 if ((p->p_flag & (P_TRACED | P_PPTRACE)) == P_TRACED) { 2872 /* 2873 * If traced, always stop. 2874 * Remove old signal from queue before the stop. 2875 * XXX shrug off debugger, it causes siginfo to 2876 * be thrown away. 2877 */ 2878 queue = &td->td_sigqueue; 2879 ksiginfo_init(&ksi); 2880 if (sigqueue_get(queue, sig, &ksi) == 0) { 2881 queue = &p->p_sigqueue; 2882 sigqueue_get(queue, sig, &ksi); 2883 } 2884 td->td_si = ksi.ksi_info; 2885 2886 mtx_unlock(&ps->ps_mtx); 2887 sig = ptracestop(td, sig, &ksi); 2888 mtx_lock(&ps->ps_mtx); 2889 2890 td->td_si.si_signo = 0; 2891 2892 /* 2893 * Keep looking if the debugger discarded or 2894 * replaced the signal. 2895 */ 2896 if (sig == 0) 2897 continue; 2898 2899 /* 2900 * If the signal became masked, re-queue it. 2901 */ 2902 if (SIGISMEMBER(td->td_sigmask, sig)) { 2903 ksi.ksi_flags |= KSI_HEAD; 2904 sigqueue_add(&p->p_sigqueue, sig, &ksi); 2905 continue; 2906 } 2907 2908 /* 2909 * If the traced bit got turned off, requeue 2910 * the signal and go back up to the top to 2911 * rescan signals. This ensures that p_sig* 2912 * and p_sigact are consistent. 2913 */ 2914 if ((p->p_flag & P_TRACED) == 0) { 2915 ksi.ksi_flags |= KSI_HEAD; 2916 sigqueue_add(queue, sig, &ksi); 2917 continue; 2918 } 2919 } 2920 2921 prop = sigprop(sig); 2922 2923 /* 2924 * Decide whether the signal should be returned. 2925 * Return the signal's number, or fall through 2926 * to clear it from the pending mask. 2927 */ 2928 switch ((intptr_t)p->p_sigacts->ps_sigact[_SIG_IDX(sig)]) { 2929 2930 case (intptr_t)SIG_DFL: 2931 /* 2932 * Don't take default actions on system processes. 2933 */ 2934 if (p->p_pid <= 1) { 2935#ifdef DIAGNOSTIC 2936 /* 2937 * Are you sure you want to ignore SIGSEGV 2938 * in init? XXX 2939 */ 2940 printf("Process (pid %lu) got signal %d\n", 2941 (u_long)p->p_pid, sig); 2942#endif 2943 break; /* == ignore */ 2944 } 2945 /* 2946 * If there is a pending stop signal to process with 2947 * default action, stop here, then clear the signal. 2948 * Traced or exiting processes should ignore stops. 2949 * Additionally, a member of an orphaned process group 2950 * should ignore tty stops. 2951 */ 2952 if (prop & SA_STOP) { 2953 if (p->p_flag & 2954 (P_TRACED | P_WEXIT | P_SINGLE_EXIT) || 2955 (p->p_pgrp->pg_jobc == 0 && 2956 prop & SA_TTYSTOP)) 2957 break; /* == ignore */ 2958 if (TD_SBDRY_INTR(td)) { 2959 KASSERT((td->td_flags & TDF_SBDRY) != 0, 2960 ("lost TDF_SBDRY")); 2961 return (-1); 2962 } 2963 mtx_unlock(&ps->ps_mtx); 2964 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, 2965 &p->p_mtx.lock_object, "Catching SIGSTOP"); 2966 sigqueue_delete(&td->td_sigqueue, sig); 2967 sigqueue_delete(&p->p_sigqueue, sig); 2968 p->p_flag |= P_STOPPED_SIG; 2969 p->p_xsig = sig; 2970 PROC_SLOCK(p); 2971 sig_suspend_threads(td, p, 0); 2972 thread_suspend_switch(td, p); 2973 PROC_SUNLOCK(p); 2974 mtx_lock(&ps->ps_mtx); 2975 goto next; 2976 } else if (prop & SA_IGNORE) { 2977 /* 2978 * Except for SIGCONT, shouldn't get here. 2979 * Default action is to ignore; drop it. 2980 */ 2981 break; /* == ignore */ 2982 } else 2983 return (sig); 2984 /*NOTREACHED*/ 2985 2986 case (intptr_t)SIG_IGN: 2987 /* 2988 * Masking above should prevent us ever trying 2989 * to take action on an ignored signal other 2990 * than SIGCONT, unless process is traced. 2991 */ 2992 if ((prop & SA_CONT) == 0 && 2993 (p->p_flag & P_TRACED) == 0) 2994 printf("issignal\n"); 2995 break; /* == ignore */ 2996 2997 default: 2998 /* 2999 * This signal has an action, let 3000 * postsig() process it. 3001 */ 3002 return (sig); 3003 } 3004 sigqueue_delete(&td->td_sigqueue, sig); /* take the signal! */ 3005 sigqueue_delete(&p->p_sigqueue, sig); 3006next:; 3007 } 3008 /* NOTREACHED */ 3009} 3010 3011void 3012thread_stopped(struct proc *p) 3013{ 3014 int n; 3015 3016 PROC_LOCK_ASSERT(p, MA_OWNED); 3017 PROC_SLOCK_ASSERT(p, MA_OWNED); 3018 n = p->p_suspcount; 3019 if (p == curproc) 3020 n++; 3021 if ((p->p_flag & P_STOPPED_SIG) && (n == p->p_numthreads)) { 3022 PROC_SUNLOCK(p); 3023 p->p_flag &= ~P_WAITED; 3024 PROC_LOCK(p->p_pptr); 3025 childproc_stopped(p, (p->p_flag & P_TRACED) ? 3026 CLD_TRAPPED : CLD_STOPPED); 3027 PROC_UNLOCK(p->p_pptr); 3028 PROC_SLOCK(p); 3029 } 3030} 3031 3032/* 3033 * Take the action for the specified signal 3034 * from the current set of pending signals. 3035 */ 3036int 3037postsig(int sig) 3038{ 3039 struct thread *td; 3040 struct proc *p; 3041 struct sigacts *ps; 3042 sig_t action; 3043 ksiginfo_t ksi; 3044 sigset_t returnmask; 3045 3046 KASSERT(sig != 0, ("postsig")); 3047 3048 td = curthread; 3049 p = td->td_proc; 3050 PROC_LOCK_ASSERT(p, MA_OWNED); 3051 ps = p->p_sigacts; 3052 mtx_assert(&ps->ps_mtx, MA_OWNED); 3053 ksiginfo_init(&ksi); 3054 if (sigqueue_get(&td->td_sigqueue, sig, &ksi) == 0 && 3055 sigqueue_get(&p->p_sigqueue, sig, &ksi) == 0) 3056 return (0); 3057 ksi.ksi_signo = sig; 3058 if (ksi.ksi_code == SI_TIMER) 3059 itimer_accept(p, ksi.ksi_timerid, &ksi); 3060 action = ps->ps_sigact[_SIG_IDX(sig)]; 3061#ifdef KTRACE 3062 if (KTRPOINT(td, KTR_PSIG)) 3063 ktrpsig(sig, action, td->td_pflags & TDP_OLDMASK ? 3064 &td->td_oldsigmask : &td->td_sigmask, ksi.ksi_code); 3065#endif 3066 if ((p->p_stops & S_SIG) != 0) { 3067 mtx_unlock(&ps->ps_mtx); 3068 stopevent(p, S_SIG, sig); 3069 mtx_lock(&ps->ps_mtx); 3070 } 3071 3072 if (action == SIG_DFL) { 3073 /* 3074 * Default action, where the default is to kill 3075 * the process. (Other cases were ignored above.) 3076 */ 3077 mtx_unlock(&ps->ps_mtx); 3078 proc_td_siginfo_capture(td, &ksi.ksi_info); 3079 sigexit(td, sig); 3080 /* NOTREACHED */ 3081 } else { 3082 /* 3083 * If we get here, the signal must be caught. 3084 */ 3085 KASSERT(action != SIG_IGN, ("postsig action %p", action)); 3086 KASSERT(!SIGISMEMBER(td->td_sigmask, sig), 3087 ("postsig action: blocked sig %d", sig)); 3088 3089 /* 3090 * Set the new mask value and also defer further 3091 * occurrences of this signal. 3092 * 3093 * Special case: user has done a sigsuspend. Here the 3094 * current mask is not of interest, but rather the 3095 * mask from before the sigsuspend is what we want 3096 * restored after the signal processing is completed. 3097 */ 3098 if (td->td_pflags & TDP_OLDMASK) { 3099 returnmask = td->td_oldsigmask; 3100 td->td_pflags &= ~TDP_OLDMASK; 3101 } else 3102 returnmask = td->td_sigmask; 3103 3104 if (p->p_sig == sig) { 3105 p->p_code = 0; 3106 p->p_sig = 0; 3107 } 3108 (*p->p_sysent->sv_sendsig)(action, &ksi, &returnmask); 3109 postsig_done(sig, td, ps); 3110 } 3111 return (1); 3112} 3113 3114void 3115proc_wkilled(struct proc *p) 3116{ 3117 3118 PROC_LOCK_ASSERT(p, MA_OWNED); 3119 if ((p->p_flag & P_WKILLED) == 0) { 3120 p->p_flag |= P_WKILLED; 3121 /* 3122 * Notify swapper that there is a process to swap in. 3123 * The notification is racy, at worst it would take 10 3124 * seconds for the swapper process to notice. 3125 */ 3126 if ((p->p_flag & (P_INMEM | P_SWAPPINGIN)) == 0) 3127 wakeup(&proc0); 3128 } 3129} 3130 3131/* 3132 * Kill the current process for stated reason. 3133 */ 3134void 3135killproc(struct proc *p, char *why) 3136{ 3137 3138 PROC_LOCK_ASSERT(p, MA_OWNED); 3139 CTR3(KTR_PROC, "killproc: proc %p (pid %d, %s)", p, p->p_pid, 3140 p->p_comm); 3141 log(LOG_ERR, "pid %d (%s), jid %d, uid %d, was killed: %s\n", 3142 p->p_pid, p->p_comm, p->p_ucred->cr_prison->pr_id, 3143 p->p_ucred ? p->p_ucred->cr_uid : -1, why); 3144 proc_wkilled(p); 3145 kern_psignal(p, SIGKILL); 3146} 3147 3148/* 3149 * Force the current process to exit with the specified signal, dumping core 3150 * if appropriate. We bypass the normal tests for masked and caught signals, 3151 * allowing unrecoverable failures to terminate the process without changing 3152 * signal state. Mark the accounting record with the signal termination. 3153 * If dumping core, save the signal number for the debugger. Calls exit and 3154 * does not return. 3155 */ 3156void 3157sigexit(struct thread *td, int sig) 3158{ 3159 struct proc *p = td->td_proc; 3160 3161 PROC_LOCK_ASSERT(p, MA_OWNED); 3162 p->p_acflag |= AXSIG; 3163 /* 3164 * We must be single-threading to generate a core dump. This 3165 * ensures that the registers in the core file are up-to-date. 3166 * Also, the ELF dump handler assumes that the thread list doesn't 3167 * change out from under it. 3168 * 3169 * XXX If another thread attempts to single-thread before us 3170 * (e.g. via fork()), we won't get a dump at all. 3171 */ 3172 if ((sigprop(sig) & SA_CORE) && thread_single(p, SINGLE_NO_EXIT) == 0) { 3173 p->p_sig = sig; 3174 /* 3175 * Log signals which would cause core dumps 3176 * (Log as LOG_INFO to appease those who don't want 3177 * these messages.) 3178 * XXX : Todo, as well as euid, write out ruid too 3179 * Note that coredump() drops proc lock. 3180 */ 3181 if (coredump(td) == 0) 3182 sig |= WCOREFLAG; 3183 if (kern_logsigexit) 3184 log(LOG_INFO, 3185 "pid %d (%s), jid %d, uid %d: exited on " 3186 "signal %d%s\n", p->p_pid, p->p_comm, 3187 p->p_ucred->cr_prison->pr_id, 3188 td->td_ucred ? td->td_ucred->cr_uid : -1, 3189 sig &~ WCOREFLAG, 3190 sig & WCOREFLAG ? " (core dumped)" : ""); 3191 } else 3192 PROC_UNLOCK(p); 3193 exit1(td, 0, sig); 3194 /* NOTREACHED */ 3195} 3196 3197/* 3198 * Send queued SIGCHLD to parent when child process's state 3199 * is changed. 3200 */ 3201static void 3202sigparent(struct proc *p, int reason, int status) 3203{ 3204 PROC_LOCK_ASSERT(p, MA_OWNED); 3205 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3206 3207 if (p->p_ksi != NULL) { 3208 p->p_ksi->ksi_signo = SIGCHLD; 3209 p->p_ksi->ksi_code = reason; 3210 p->p_ksi->ksi_status = status; 3211 p->p_ksi->ksi_pid = p->p_pid; 3212 p->p_ksi->ksi_uid = p->p_ucred->cr_ruid; 3213 if (KSI_ONQ(p->p_ksi)) 3214 return; 3215 } 3216 pksignal(p->p_pptr, SIGCHLD, p->p_ksi); 3217} 3218 3219static void 3220childproc_jobstate(struct proc *p, int reason, int sig) 3221{ 3222 struct sigacts *ps; 3223 3224 PROC_LOCK_ASSERT(p, MA_OWNED); 3225 PROC_LOCK_ASSERT(p->p_pptr, MA_OWNED); 3226 3227 /* 3228 * Wake up parent sleeping in kern_wait(), also send 3229 * SIGCHLD to parent, but SIGCHLD does not guarantee 3230 * that parent will awake, because parent may masked 3231 * the signal. 3232 */ 3233 p->p_pptr->p_flag |= P_STATCHILD; 3234 wakeup(p->p_pptr); 3235 3236 ps = p->p_pptr->p_sigacts; 3237 mtx_lock(&ps->ps_mtx); 3238 if ((ps->ps_flag & PS_NOCLDSTOP) == 0) { 3239 mtx_unlock(&ps->ps_mtx); 3240 sigparent(p, reason, sig); 3241 } else 3242 mtx_unlock(&ps->ps_mtx); 3243} 3244 3245void 3246childproc_stopped(struct proc *p, int reason) 3247{ 3248 3249 childproc_jobstate(p, reason, p->p_xsig); 3250} 3251 3252void 3253childproc_continued(struct proc *p) 3254{ 3255 childproc_jobstate(p, CLD_CONTINUED, SIGCONT); 3256} 3257 3258void 3259childproc_exited(struct proc *p) 3260{ 3261 int reason, status; 3262 3263 if (WCOREDUMP(p->p_xsig)) { 3264 reason = CLD_DUMPED; 3265 status = WTERMSIG(p->p_xsig); 3266 } else if (WIFSIGNALED(p->p_xsig)) { 3267 reason = CLD_KILLED; 3268 status = WTERMSIG(p->p_xsig); 3269 } else { 3270 reason = CLD_EXITED; 3271 status = p->p_xexit; 3272 } 3273 /* 3274 * XXX avoid calling wakeup(p->p_pptr), the work is 3275 * done in exit1(). 3276 */ 3277 sigparent(p, reason, status); 3278} 3279 3280/* 3281 * We only have 1 character for the core count in the format 3282 * string, so the range will be 0-9 3283 */ 3284#define MAX_NUM_CORES 10 3285static int num_cores = 5; 3286 3287static int 3288sysctl_debug_num_cores_check (SYSCTL_HANDLER_ARGS) 3289{ 3290 int error; 3291 int new_val; 3292 3293 new_val = num_cores; 3294 error = sysctl_handle_int(oidp, &new_val, 0, req); 3295 if (error != 0 || req->newptr == NULL) 3296 return (error); 3297 if (new_val > MAX_NUM_CORES) 3298 new_val = MAX_NUM_CORES; 3299 if (new_val < 0) 3300 new_val = 0; 3301 num_cores = new_val; 3302 return (0); 3303} 3304SYSCTL_PROC(_debug, OID_AUTO, ncores, CTLTYPE_INT|CTLFLAG_RW, 3305 0, sizeof(int), sysctl_debug_num_cores_check, "I", ""); 3306 3307#define GZ_SUFFIX ".gz" 3308 3309#ifdef GZIO 3310static int compress_user_cores = 1; 3311SYSCTL_INT(_kern, OID_AUTO, compress_user_cores, CTLFLAG_RWTUN, 3312 &compress_user_cores, 0, "Compression of user corefiles"); 3313 3314int compress_user_cores_gzlevel = 6; 3315SYSCTL_INT(_kern, OID_AUTO, compress_user_cores_gzlevel, CTLFLAG_RWTUN, 3316 &compress_user_cores_gzlevel, 0, "Corefile gzip compression level"); 3317#else 3318static int compress_user_cores = 0; 3319#endif 3320 3321/* 3322 * Protect the access to corefilename[] by allproc_lock. 3323 */ 3324#define corefilename_lock allproc_lock 3325 3326static char corefilename[MAXPATHLEN] = {"%N.core"}; 3327TUNABLE_STR("kern.corefile", corefilename, sizeof(corefilename)); 3328 3329static int 3330sysctl_kern_corefile(SYSCTL_HANDLER_ARGS) 3331{ 3332 int error; 3333 3334 sx_xlock(&corefilename_lock); 3335 error = sysctl_handle_string(oidp, corefilename, sizeof(corefilename), 3336 req); 3337 sx_xunlock(&corefilename_lock); 3338 3339 return (error); 3340} 3341SYSCTL_PROC(_kern, OID_AUTO, corefile, CTLTYPE_STRING | CTLFLAG_RW | 3342 CTLFLAG_MPSAFE, 0, 0, sysctl_kern_corefile, "A", 3343 "Process corefile name format string"); 3344 3345static void 3346vnode_close_locked(struct thread *td, struct vnode *vp) 3347{ 3348 3349 VOP_UNLOCK(vp, 0); 3350 vn_close(vp, FWRITE, td->td_ucred, td); 3351} 3352 3353/* 3354 * If the core format has a %I in it, then we need to check 3355 * for existing corefiles before defining a name. 3356 * To do this we iterate over 0..num_cores to find a 3357 * non-existing core file name to use. If all core files are 3358 * already used we choose the oldest one. 3359 */ 3360static int 3361corefile_open_last(struct thread *td, char *name, int indexpos, 3362 struct vnode **vpp) 3363{ 3364 struct vnode *oldvp, *nextvp, *vp; 3365 struct vattr vattr; 3366 struct nameidata nd; 3367 int error, i, flags, oflags, cmode; 3368 struct timespec lasttime; 3369 3370 nextvp = oldvp = NULL; 3371 cmode = S_IRUSR | S_IWUSR; 3372 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3373 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3374 3375 for (i = 0; i < num_cores; i++) { 3376 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3377 name[indexpos] = '0' + i; 3378 3379 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3380 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3381 NULL); 3382 if (error != 0) 3383 break; 3384 3385 vp = nd.ni_vp; 3386 NDFREE(&nd, NDF_ONLY_PNBUF); 3387 if ((flags & O_CREAT) == O_CREAT) { 3388 nextvp = vp; 3389 break; 3390 } 3391 3392 error = VOP_GETATTR(vp, &vattr, td->td_ucred); 3393 if (error != 0) { 3394 vnode_close_locked(td, vp); 3395 break; 3396 } 3397 3398 if (oldvp == NULL || 3399 lasttime.tv_sec > vattr.va_mtime.tv_sec || 3400 (lasttime.tv_sec == vattr.va_mtime.tv_sec && 3401 lasttime.tv_nsec >= vattr.va_mtime.tv_nsec)) { 3402 if (oldvp != NULL) 3403 vnode_close_locked(td, oldvp); 3404 oldvp = vp; 3405 lasttime = vattr.va_mtime; 3406 } else { 3407 vnode_close_locked(td, vp); 3408 } 3409 } 3410 3411 if (oldvp != NULL) { 3412 if (nextvp == NULL) { 3413 if ((td->td_proc->p_flag & P_SUGID) != 0) { 3414 error = EFAULT; 3415 vnode_close_locked(td, oldvp); 3416 } else { 3417 nextvp = oldvp; 3418 } 3419 } else { 3420 vnode_close_locked(td, oldvp); 3421 } 3422 } 3423 if (error != 0) { 3424 if (nextvp != NULL) 3425 vnode_close_locked(td, oldvp); 3426 } else { 3427 *vpp = nextvp; 3428 } 3429 3430 return (error); 3431} 3432 3433/* 3434 * corefile_open(comm, uid, pid, td, compress, vpp, namep) 3435 * Expand the name described in corefilename, using name, uid, and pid 3436 * and open/create core file. 3437 * corefilename is a printf-like string, with three format specifiers: 3438 * %N name of process ("name") 3439 * %P process id (pid) 3440 * %U user id (uid) 3441 * For example, "%N.core" is the default; they can be disabled completely 3442 * by using "/dev/null", or all core files can be stored in "/cores/%U/%N-%P". 3443 * This is controlled by the sysctl variable kern.corefile (see above). 3444 */ 3445static int 3446corefile_open(const char *comm, uid_t uid, pid_t pid, struct thread *td, 3447 int compress, struct vnode **vpp, char **namep) 3448{ 3449 struct sbuf sb; 3450 struct nameidata nd; 3451 const char *format; 3452 char *hostname, *name; 3453 int cmode, error, flags, i, indexpos, oflags; 3454 3455 hostname = NULL; 3456 format = corefilename; 3457 name = malloc(MAXPATHLEN, M_TEMP, M_WAITOK | M_ZERO); 3458 indexpos = -1; 3459 (void)sbuf_new(&sb, name, MAXPATHLEN, SBUF_FIXEDLEN); 3460 sx_slock(&corefilename_lock); 3461 for (i = 0; format[i] != '\0'; i++) { 3462 switch (format[i]) { 3463 case '%': /* Format character */ 3464 i++; 3465 switch (format[i]) { 3466 case '%': 3467 sbuf_putc(&sb, '%'); 3468 break; 3469 case 'H': /* hostname */ 3470 if (hostname == NULL) { 3471 hostname = malloc(MAXHOSTNAMELEN, 3472 M_TEMP, M_WAITOK); 3473 } 3474 getcredhostname(td->td_ucred, hostname, 3475 MAXHOSTNAMELEN); 3476 sbuf_printf(&sb, "%s", hostname); 3477 break; 3478 case 'I': /* autoincrementing index */ 3479 sbuf_printf(&sb, "0"); 3480 indexpos = sbuf_len(&sb) - 1; 3481 break; 3482 case 'N': /* process name */ 3483 sbuf_printf(&sb, "%s", comm); 3484 break; 3485 case 'P': /* process id */ 3486 sbuf_printf(&sb, "%u", pid); 3487 break; 3488 case 'U': /* user id */ 3489 sbuf_printf(&sb, "%u", uid); 3490 break; 3491 default: 3492 log(LOG_ERR, 3493 "Unknown format character %c in " 3494 "corename `%s'\n", format[i], format); 3495 break; 3496 } 3497 break; 3498 default: 3499 sbuf_putc(&sb, format[i]); 3500 break; 3501 } 3502 } 3503 sx_sunlock(&corefilename_lock); 3504 free(hostname, M_TEMP); 3505 if (compress) 3506 sbuf_printf(&sb, GZ_SUFFIX); 3507 if (sbuf_error(&sb) != 0) { 3508 log(LOG_ERR, "pid %ld (%s), uid (%lu): corename is too " 3509 "long\n", (long)pid, comm, (u_long)uid); 3510 sbuf_delete(&sb); 3511 free(name, M_TEMP); 3512 return (ENOMEM); 3513 } 3514 sbuf_finish(&sb); 3515 sbuf_delete(&sb); 3516 3517 if (indexpos != -1) { 3518 error = corefile_open_last(td, name, indexpos, vpp); 3519 if (error != 0) { 3520 log(LOG_ERR, 3521 "pid %d (%s), uid (%u): Path `%s' failed " 3522 "on initial open test, error = %d\n", 3523 pid, comm, uid, name, error); 3524 } 3525 } else { 3526 cmode = S_IRUSR | S_IWUSR; 3527 oflags = VN_OPEN_NOAUDIT | VN_OPEN_NAMECACHE | 3528 (capmode_coredump ? VN_OPEN_NOCAPCHECK : 0); 3529 flags = O_CREAT | FWRITE | O_NOFOLLOW; 3530 if ((td->td_proc->p_flag & P_SUGID) != 0) 3531 flags |= O_EXCL; 3532 3533 NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, name, td); 3534 error = vn_open_cred(&nd, &flags, cmode, oflags, td->td_ucred, 3535 NULL); 3536 if (error == 0) { 3537 *vpp = nd.ni_vp; 3538 NDFREE(&nd, NDF_ONLY_PNBUF); 3539 } 3540 } 3541 3542 if (error != 0) { 3543#ifdef AUDIT 3544 audit_proc_coredump(td, name, error); 3545#endif 3546 free(name, M_TEMP); 3547 return (error); 3548 } 3549 *namep = name; 3550 return (0); 3551} 3552 3553static int 3554coredump_sanitise_path(const char *path) 3555{ 3556 size_t i; 3557 3558 /* 3559 * Only send a subset of ASCII to devd(8) because it 3560 * might pass these strings to sh -c. 3561 */ 3562 for (i = 0; path[i]; i++) 3563 if (!(isalpha(path[i]) || isdigit(path[i])) && 3564 path[i] != '/' && path[i] != '.' && 3565 path[i] != '-') 3566 return (0); 3567 3568 return (1); 3569} 3570 3571/* 3572 * Dump a process' core. The main routine does some 3573 * policy checking, and creates the name of the coredump; 3574 * then it passes on a vnode and a size limit to the process-specific 3575 * coredump routine if there is one; if there _is not_ one, it returns 3576 * ENOSYS; otherwise it returns the error from the process-specific routine. 3577 */ 3578 3579static int 3580coredump(struct thread *td) 3581{ 3582 struct proc *p = td->td_proc; 3583 struct ucred *cred = td->td_ucred; 3584 struct vnode *vp; 3585 struct flock lf; 3586 struct vattr vattr; 3587 int error, error1, locked; 3588 char *name; /* name of corefile */ 3589 void *rl_cookie; 3590 off_t limit; 3591 char *data = NULL; 3592 char *fullpath, *freepath = NULL; 3593 size_t len; 3594 static const char comm_name[] = "comm="; 3595 static const char core_name[] = "core="; 3596 3597 PROC_LOCK_ASSERT(p, MA_OWNED); 3598 MPASS((p->p_flag & P_HADTHREADS) == 0 || p->p_singlethread == td); 3599 _STOPEVENT(p, S_CORE, 0); 3600 3601 if (!do_coredump || (!sugid_coredump && (p->p_flag & P_SUGID) != 0) || 3602 (p->p_flag2 & P2_NOTRACE) != 0) { 3603 PROC_UNLOCK(p); 3604 return (EFAULT); 3605 } 3606 3607 /* 3608 * Note that the bulk of limit checking is done after 3609 * the corefile is created. The exception is if the limit 3610 * for corefiles is 0, in which case we don't bother 3611 * creating the corefile at all. This layout means that 3612 * a corefile is truncated instead of not being created, 3613 * if it is larger than the limit. 3614 */ 3615 limit = (off_t)lim_cur(td, RLIMIT_CORE); 3616 if (limit == 0 || racct_get_available(p, RACCT_CORE) == 0) { 3617 PROC_UNLOCK(p); 3618 return (EFBIG); 3619 } 3620 PROC_UNLOCK(p); 3621 3622 error = corefile_open(p->p_comm, cred->cr_uid, p->p_pid, td, 3623 compress_user_cores, &vp, &name); 3624 if (error != 0) 3625 return (error); 3626 3627 /* 3628 * Don't dump to non-regular files or files with links. 3629 * Do not dump into system files. Effective user must own the corefile. 3630 */ 3631 if (vp->v_type != VREG || VOP_GETATTR(vp, &vattr, cred) != 0 || 3632 vattr.va_nlink != 1 || (vp->v_vflag & VV_SYSTEM) != 0 || 3633 vattr.va_uid != cred->cr_uid) { 3634 VOP_UNLOCK(vp, 0); 3635 error = EFAULT; 3636 goto out; 3637 } 3638 3639 VOP_UNLOCK(vp, 0); 3640 3641 /* Postpone other writers, including core dumps of other processes. */ 3642 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX); 3643 3644 lf.l_whence = SEEK_SET; 3645 lf.l_start = 0; 3646 lf.l_len = 0; 3647 lf.l_type = F_WRLCK; 3648 locked = (VOP_ADVLOCK(vp, (caddr_t)p, F_SETLK, &lf, F_FLOCK) == 0); 3649 3650 VATTR_NULL(&vattr); 3651 vattr.va_size = 0; 3652 if (set_core_nodump_flag) 3653 vattr.va_flags = UF_NODUMP; 3654 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 3655 VOP_SETATTR(vp, &vattr, cred); 3656 VOP_UNLOCK(vp, 0); 3657 PROC_LOCK(p); 3658 p->p_acflag |= ACORE; 3659 PROC_UNLOCK(p); 3660 3661 if (p->p_sysent->sv_coredump != NULL) { 3662 error = p->p_sysent->sv_coredump(td, vp, limit, 3663 compress_user_cores ? IMGACT_CORE_COMPRESS : 0); 3664 } else { 3665 error = ENOSYS; 3666 } 3667 3668 if (locked) { 3669 lf.l_type = F_UNLCK; 3670 VOP_ADVLOCK(vp, (caddr_t)p, F_UNLCK, &lf, F_FLOCK); 3671 } 3672 vn_rangelock_unlock(vp, rl_cookie); 3673 3674 /* 3675 * Notify the userland helper that a process triggered a core dump. 3676 * This allows the helper to run an automated debugging session. 3677 */ 3678 if (error != 0 || coredump_devctl == 0) 3679 goto out; 3680 len = MAXPATHLEN * 2 + sizeof(comm_name) - 1 + 3681 sizeof(' ') + sizeof(core_name) - 1; 3682 data = malloc(len, M_TEMP, M_WAITOK); 3683 if (vn_fullpath_global(td, p->p_textvp, &fullpath, &freepath) != 0) 3684 goto out; 3685 if (!coredump_sanitise_path(fullpath)) 3686 goto out; 3687 snprintf(data, len, "%s%s ", comm_name, fullpath); 3688 free(freepath, M_TEMP); 3689 freepath = NULL; 3690 if (vn_fullpath_global(td, vp, &fullpath, &freepath) != 0) 3691 goto out; 3692 if (!coredump_sanitise_path(fullpath)) 3693 goto out; 3694 strlcat(data, core_name, len); 3695 strlcat(data, fullpath, len); 3696 devctl_notify("kernel", "signal", "coredump", data); 3697out: 3698 error1 = vn_close(vp, FWRITE, cred, td); 3699 if (error == 0) 3700 error = error1; 3701#ifdef AUDIT 3702 audit_proc_coredump(td, name, error); 3703#endif 3704 free(freepath, M_TEMP); 3705 free(data, M_TEMP); 3706 free(name, M_TEMP); 3707 return (error); 3708} 3709 3710/* 3711 * Nonexistent system call-- signal process (may want to handle it). Flag 3712 * error in case process won't see signal immediately (blocked or ignored). 3713 */ 3714#ifndef _SYS_SYSPROTO_H_ 3715struct nosys_args { 3716 int dummy; 3717}; 3718#endif 3719/* ARGSUSED */ 3720int 3721nosys(struct thread *td, struct nosys_args *args) 3722{ 3723 struct proc *p; 3724 3725 p = td->td_proc; 3726 3727 PROC_LOCK(p); 3728 tdsignal(td, SIGSYS); 3729 PROC_UNLOCK(p); 3730 if (kern_lognosys == 1 || kern_lognosys == 3) { 3731 uprintf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3732 td->td_sa.code); 3733 } 3734 if (kern_lognosys == 2 || kern_lognosys == 3 || 3735 (p->p_pid == 1 && (kern_lognosys & 3) == 0)) { 3736 printf("pid %d comm %s: nosys %d\n", p->p_pid, p->p_comm, 3737 td->td_sa.code); 3738 } 3739 return (ENOSYS); 3740} 3741 3742/* 3743 * Send a SIGIO or SIGURG signal to a process or process group using stored 3744 * credentials rather than those of the current process. 3745 */ 3746void 3747pgsigio(struct sigio **sigiop, int sig, int checkctty) 3748{ 3749 ksiginfo_t ksi; 3750 struct sigio *sigio; 3751 3752 ksiginfo_init(&ksi); 3753 ksi.ksi_signo = sig; 3754 ksi.ksi_code = SI_KERNEL; 3755 3756 SIGIO_LOCK(); 3757 sigio = *sigiop; 3758 if (sigio == NULL) { 3759 SIGIO_UNLOCK(); 3760 return; 3761 } 3762 if (sigio->sio_pgid > 0) { 3763 PROC_LOCK(sigio->sio_proc); 3764 if (CANSIGIO(sigio->sio_ucred, sigio->sio_proc->p_ucred)) 3765 kern_psignal(sigio->sio_proc, sig); 3766 PROC_UNLOCK(sigio->sio_proc); 3767 } else if (sigio->sio_pgid < 0) { 3768 struct proc *p; 3769 3770 PGRP_LOCK(sigio->sio_pgrp); 3771 LIST_FOREACH(p, &sigio->sio_pgrp->pg_members, p_pglist) { 3772 PROC_LOCK(p); 3773 if (p->p_state == PRS_NORMAL && 3774 CANSIGIO(sigio->sio_ucred, p->p_ucred) && 3775 (checkctty == 0 || (p->p_flag & P_CONTROLT))) 3776 kern_psignal(p, sig); 3777 PROC_UNLOCK(p); 3778 } 3779 PGRP_UNLOCK(sigio->sio_pgrp); 3780 } 3781 SIGIO_UNLOCK(); 3782} 3783 3784static int 3785filt_sigattach(struct knote *kn) 3786{ 3787 struct proc *p = curproc; 3788 3789 kn->kn_ptr.p_proc = p; 3790 kn->kn_flags |= EV_CLEAR; /* automatically set */ 3791 3792 knlist_add(p->p_klist, kn, 0); 3793 3794 return (0); 3795} 3796 3797static void 3798filt_sigdetach(struct knote *kn) 3799{ 3800 struct proc *p = kn->kn_ptr.p_proc; 3801 3802 knlist_remove(p->p_klist, kn, 0); 3803} 3804 3805/* 3806 * signal knotes are shared with proc knotes, so we apply a mask to 3807 * the hint in order to differentiate them from process hints. This 3808 * could be avoided by using a signal-specific knote list, but probably 3809 * isn't worth the trouble. 3810 */ 3811static int 3812filt_signal(struct knote *kn, long hint) 3813{ 3814 3815 if (hint & NOTE_SIGNAL) { 3816 hint &= ~NOTE_SIGNAL; 3817 3818 if (kn->kn_id == hint) 3819 kn->kn_data++; 3820 } 3821 return (kn->kn_data != 0); 3822} 3823 3824struct sigacts * 3825sigacts_alloc(void) 3826{ 3827 struct sigacts *ps; 3828 3829 ps = malloc(sizeof(struct sigacts), M_SUBPROC, M_WAITOK | M_ZERO); 3830 refcount_init(&ps->ps_refcnt, 1); 3831 mtx_init(&ps->ps_mtx, "sigacts", NULL, MTX_DEF); 3832 return (ps); 3833} 3834 3835void 3836sigacts_free(struct sigacts *ps) 3837{ 3838 3839 if (refcount_release(&ps->ps_refcnt) == 0) 3840 return; 3841 mtx_destroy(&ps->ps_mtx); 3842 free(ps, M_SUBPROC); 3843} 3844 3845struct sigacts * 3846sigacts_hold(struct sigacts *ps) 3847{ 3848 3849 refcount_acquire(&ps->ps_refcnt); 3850 return (ps); 3851} 3852 3853void 3854sigacts_copy(struct sigacts *dest, struct sigacts *src) 3855{ 3856 3857 KASSERT(dest->ps_refcnt == 1, ("sigacts_copy to shared dest")); 3858 mtx_lock(&src->ps_mtx); 3859 bcopy(src, dest, offsetof(struct sigacts, ps_refcnt)); 3860 mtx_unlock(&src->ps_mtx); 3861} 3862 3863int 3864sigacts_shared(struct sigacts *ps) 3865{ 3866 3867 return (ps->ps_refcnt > 1); 3868} 3869 3870void 3871sig_drop_caught(struct proc *p) 3872{ 3873 int sig; 3874 struct sigacts *ps; 3875 3876 ps = p->p_sigacts; 3877 PROC_LOCK_ASSERT(p, MA_OWNED); 3878 mtx_assert(&ps->ps_mtx, MA_OWNED); 3879 while (SIGNOTEMPTY(ps->ps_sigcatch)) { 3880 sig = sig_ffs(&ps->ps_sigcatch); 3881 sigdflt(ps, sig); 3882 if ((sigprop(sig) & SA_IGNORE) != 0) 3883 sigqueue_delete_proc(p, sig); 3884 } 3885} 3886