1/*- 2 * Copyright (c) 1986, 1988, 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_shutdown.c 8.3 (Berkeley) 1/21/94 35 */ 36 37#include <sys/cdefs.h> 38__FBSDID("$FreeBSD: stable/11/sys/kern/kern_shutdown.c 352719 2019-09-25 19:51:58Z avg $"); 39 40#include "opt_ddb.h" 41#include "opt_kdb.h" 42#include "opt_panic.h" 43#include "opt_sched.h" 44#include "opt_watchdog.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/bio.h> 49#include <sys/buf.h> 50#include <sys/conf.h> 51#include <sys/cons.h> 52#include <sys/eventhandler.h> 53#include <sys/filedesc.h> 54#include <sys/jail.h> 55#include <sys/kdb.h> 56#include <sys/kernel.h> 57#include <sys/kerneldump.h> 58#include <sys/kthread.h> 59#include <sys/ktr.h> 60#include <sys/malloc.h> 61#include <sys/mount.h> 62#include <sys/priv.h> 63#include <sys/proc.h> 64#include <sys/reboot.h> 65#include <sys/resourcevar.h> 66#include <sys/rwlock.h> 67#include <sys/sched.h> 68#include <sys/smp.h> 69#include <sys/sysctl.h> 70#include <sys/sysproto.h> 71#include <sys/taskqueue.h> 72#include <sys/vnode.h> 73#include <sys/watchdog.h> 74 75#include <ddb/ddb.h> 76 77#include <machine/cpu.h> 78#include <machine/dump.h> 79#include <machine/pcb.h> 80#include <machine/smp.h> 81 82#include <security/mac/mac_framework.h> 83 84#include <vm/vm.h> 85#include <vm/vm_object.h> 86#include <vm/vm_page.h> 87#include <vm/vm_pager.h> 88#include <vm/swap_pager.h> 89 90#include <sys/signalvar.h> 91 92static MALLOC_DEFINE(M_DUMPER, "dumper", "dumper block buffer"); 93 94#ifndef PANIC_REBOOT_WAIT_TIME 95#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */ 96#endif 97static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME; 98SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RWTUN, 99 &panic_reboot_wait_time, 0, 100 "Seconds to wait before rebooting after a panic"); 101 102/* 103 * Note that stdarg.h and the ANSI style va_start macro is used for both 104 * ANSI and traditional C compilers. 105 */ 106#include <machine/stdarg.h> 107 108#ifdef KDB 109#ifdef KDB_UNATTENDED 110static int debugger_on_panic = 0; 111#else 112static int debugger_on_panic = 1; 113#endif 114SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, 115 CTLFLAG_RWTUN | CTLFLAG_SECURE, 116 &debugger_on_panic, 0, "Run debugger on kernel panic"); 117 118int debugger_on_trap = 0; 119SYSCTL_INT(_debug, OID_AUTO, debugger_on_trap, 120 CTLFLAG_RWTUN | CTLFLAG_SECURE, 121 &debugger_on_trap, 0, "Run debugger on kernel trap before panic"); 122 123#ifdef KDB_TRACE 124static int trace_on_panic = 1; 125#else 126static int trace_on_panic = 0; 127#endif 128SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, 129 CTLFLAG_RWTUN | CTLFLAG_SECURE, 130 &trace_on_panic, 0, "Print stack trace on kernel panic"); 131#endif /* KDB */ 132 133static int sync_on_panic = 0; 134SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RWTUN, 135 &sync_on_panic, 0, "Do a sync before rebooting from a panic"); 136 137static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, 138 "Shutdown environment"); 139 140#ifndef DIAGNOSTIC 141static int show_busybufs; 142#else 143static int show_busybufs = 1; 144#endif 145SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW, 146 &show_busybufs, 0, ""); 147 148int suspend_blocked = 0; 149SYSCTL_INT(_kern, OID_AUTO, suspend_blocked, CTLFLAG_RW, 150 &suspend_blocked, 0, "Block suspend due to a pending shutdown"); 151 152/* 153 * Variable panicstr contains argument to first call to panic; used as flag 154 * to indicate that the kernel has already called panic. 155 */ 156const char *panicstr; 157 158int dumping; /* system is dumping */ 159int rebooting; /* system is rebooting */ 160static struct dumperinfo dumper; /* our selected dumper */ 161 162/* Context information for dump-debuggers. */ 163static struct pcb dumppcb; /* Registers. */ 164lwpid_t dumptid; /* Thread ID. */ 165 166static struct cdevsw reroot_cdevsw = { 167 .d_version = D_VERSION, 168 .d_name = "reroot", 169}; 170 171static void poweroff_wait(void *, int); 172static void shutdown_halt(void *junk, int howto); 173static void shutdown_panic(void *junk, int howto); 174static void shutdown_reset(void *junk, int howto); 175static int kern_reroot(void); 176 177/* register various local shutdown events */ 178static void 179shutdown_conf(void *unused) 180{ 181 182 EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL, 183 SHUTDOWN_PRI_FIRST); 184 EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL, 185 SHUTDOWN_PRI_LAST + 100); 186 EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL, 187 SHUTDOWN_PRI_LAST + 100); 188 EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL, 189 SHUTDOWN_PRI_LAST + 200); 190} 191 192SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL); 193 194/* 195 * The only reason this exists is to create the /dev/reroot/ directory, 196 * used by reroot code in init(8) as a mountpoint for tmpfs. 197 */ 198static void 199reroot_conf(void *unused) 200{ 201 int error; 202 struct cdev *cdev; 203 204 error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &cdev, 205 &reroot_cdevsw, NULL, UID_ROOT, GID_WHEEL, 0600, "reroot/reroot"); 206 if (error != 0) { 207 printf("%s: failed to create device node, error %d", 208 __func__, error); 209 } 210} 211 212SYSINIT(reroot_conf, SI_SUB_DEVFS, SI_ORDER_ANY, reroot_conf, NULL); 213 214/* 215 * The system call that results in a reboot. 216 */ 217/* ARGSUSED */ 218int 219sys_reboot(struct thread *td, struct reboot_args *uap) 220{ 221 int error; 222 223 error = 0; 224#ifdef MAC 225 error = mac_system_check_reboot(td->td_ucred, uap->opt); 226#endif 227 if (error == 0) 228 error = priv_check(td, PRIV_REBOOT); 229 if (error == 0) { 230 if (uap->opt & RB_REROOT) { 231 error = kern_reroot(); 232 } else { 233 mtx_lock(&Giant); 234 kern_reboot(uap->opt); 235 mtx_unlock(&Giant); 236 } 237 } 238 return (error); 239} 240 241static void 242shutdown_nice_task_fn(void *arg, int pending __unused) 243{ 244 int howto; 245 246 howto = (uintptr_t)arg; 247 /* Send a signal to init(8) and have it shutdown the world. */ 248 PROC_LOCK(initproc); 249 if (howto & RB_POWEROFF) 250 kern_psignal(initproc, SIGUSR2); 251 else if (howto & RB_HALT) 252 kern_psignal(initproc, SIGUSR1); 253 else 254 kern_psignal(initproc, SIGINT); 255 PROC_UNLOCK(initproc); 256} 257 258static struct task shutdown_nice_task = TASK_INITIALIZER(0, 259 &shutdown_nice_task_fn, NULL); 260 261/* 262 * Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC 263 */ 264void 265shutdown_nice(int howto) 266{ 267 268 if (initproc != NULL && !SCHEDULER_STOPPED()) { 269 shutdown_nice_task.ta_context = (void *)(uintptr_t)howto; 270 taskqueue_enqueue(taskqueue_fast, &shutdown_nice_task); 271 } else { 272 /* 273 * No init(8) running, or scheduler would not allow it 274 * to run, so simply reboot. 275 */ 276 kern_reboot(howto | RB_NOSYNC); 277 } 278} 279 280static void 281print_uptime(void) 282{ 283 int f; 284 struct timespec ts; 285 286 getnanouptime(&ts); 287 printf("Uptime: "); 288 f = 0; 289 if (ts.tv_sec >= 86400) { 290 printf("%ldd", (long)ts.tv_sec / 86400); 291 ts.tv_sec %= 86400; 292 f = 1; 293 } 294 if (f || ts.tv_sec >= 3600) { 295 printf("%ldh", (long)ts.tv_sec / 3600); 296 ts.tv_sec %= 3600; 297 f = 1; 298 } 299 if (f || ts.tv_sec >= 60) { 300 printf("%ldm", (long)ts.tv_sec / 60); 301 ts.tv_sec %= 60; 302 f = 1; 303 } 304 printf("%lds\n", (long)ts.tv_sec); 305} 306 307int 308doadump(boolean_t textdump) 309{ 310 boolean_t coredump; 311 int error; 312 313 error = 0; 314 if (dumping) 315 return (EBUSY); 316 if (dumper.dumper == NULL) 317 return (ENXIO); 318 319 savectx(&dumppcb); 320 dumptid = curthread->td_tid; 321 dumping++; 322 323 coredump = TRUE; 324#ifdef DDB 325 if (textdump && textdump_pending) { 326 coredump = FALSE; 327 textdump_dumpsys(&dumper); 328 } 329#endif 330 if (coredump) 331 error = dumpsys(&dumper); 332 333 dumping--; 334 return (error); 335} 336 337/* 338 * Shutdown the system cleanly to prepare for reboot, halt, or power off. 339 */ 340void 341kern_reboot(int howto) 342{ 343 static int once = 0; 344 345#if defined(SMP) 346 /* 347 * Bind us to CPU 0 so that all shutdown code runs there. Some 348 * systems don't shutdown properly (i.e., ACPI power off) if we 349 * run on another processor. 350 */ 351 if (!SCHEDULER_STOPPED()) { 352 thread_lock(curthread); 353 sched_bind(curthread, 0); 354 thread_unlock(curthread); 355 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0")); 356 } 357#endif 358 /* We're in the process of rebooting. */ 359 rebooting = 1; 360 361 /* We are out of the debugger now. */ 362 kdb_active = 0; 363 364 /* 365 * Do any callouts that should be done BEFORE syncing the filesystems. 366 */ 367 EVENTHANDLER_INVOKE(shutdown_pre_sync, howto); 368 369 /* 370 * Now sync filesystems 371 */ 372 if (!cold && (howto & RB_NOSYNC) == 0 && once == 0) { 373 once = 1; 374 bufshutdown(show_busybufs); 375 } 376 377 print_uptime(); 378 379 cngrab(); 380 381 /* 382 * Ok, now do things that assume all filesystem activity has 383 * been completed. 384 */ 385 EVENTHANDLER_INVOKE(shutdown_post_sync, howto); 386 387 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping) 388 doadump(TRUE); 389 390 /* Now that we're going to really halt the system... */ 391 EVENTHANDLER_INVOKE(shutdown_final, howto); 392 393 for(;;) ; /* safety against shutdown_reset not working */ 394 /* NOTREACHED */ 395} 396 397/* 398 * The system call that results in changing the rootfs. 399 */ 400static int 401kern_reroot(void) 402{ 403 struct vnode *oldrootvnode, *vp; 404 struct mount *mp, *devmp; 405 int error; 406 407 if (curproc != initproc) 408 return (EPERM); 409 410 /* 411 * Mark the filesystem containing currently-running executable 412 * (the temporary copy of init(8)) busy. 413 */ 414 vp = curproc->p_textvp; 415 error = vn_lock(vp, LK_SHARED); 416 if (error != 0) 417 return (error); 418 mp = vp->v_mount; 419 error = vfs_busy(mp, MBF_NOWAIT); 420 if (error != 0) { 421 vfs_ref(mp); 422 VOP_UNLOCK(vp, 0); 423 error = vfs_busy(mp, 0); 424 vn_lock(vp, LK_SHARED | LK_RETRY); 425 vfs_rel(mp); 426 if (error != 0) { 427 VOP_UNLOCK(vp, 0); 428 return (ENOENT); 429 } 430 if (vp->v_iflag & VI_DOOMED) { 431 VOP_UNLOCK(vp, 0); 432 vfs_unbusy(mp); 433 return (ENOENT); 434 } 435 } 436 VOP_UNLOCK(vp, 0); 437 438 /* 439 * Remove the filesystem containing currently-running executable 440 * from the mount list, to prevent it from being unmounted 441 * by vfs_unmountall(), and to avoid confusing vfs_mountroot(). 442 * 443 * Also preserve /dev - forcibly unmounting it could cause driver 444 * reinitialization. 445 */ 446 447 vfs_ref(rootdevmp); 448 devmp = rootdevmp; 449 rootdevmp = NULL; 450 451 mtx_lock(&mountlist_mtx); 452 TAILQ_REMOVE(&mountlist, mp, mnt_list); 453 TAILQ_REMOVE(&mountlist, devmp, mnt_list); 454 mtx_unlock(&mountlist_mtx); 455 456 oldrootvnode = rootvnode; 457 458 /* 459 * Unmount everything except for the two filesystems preserved above. 460 */ 461 vfs_unmountall(); 462 463 /* 464 * Add /dev back; vfs_mountroot() will move it into its new place. 465 */ 466 mtx_lock(&mountlist_mtx); 467 TAILQ_INSERT_HEAD(&mountlist, devmp, mnt_list); 468 mtx_unlock(&mountlist_mtx); 469 rootdevmp = devmp; 470 vfs_rel(rootdevmp); 471 472 /* 473 * Mount the new rootfs. 474 */ 475 vfs_mountroot(); 476 477 /* 478 * Update all references to the old rootvnode. 479 */ 480 mountcheckdirs(oldrootvnode, rootvnode); 481 482 /* 483 * Add the temporary filesystem back and unbusy it. 484 */ 485 mtx_lock(&mountlist_mtx); 486 TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); 487 mtx_unlock(&mountlist_mtx); 488 vfs_unbusy(mp); 489 490 return (0); 491} 492 493/* 494 * If the shutdown was a clean halt, behave accordingly. 495 */ 496static void 497shutdown_halt(void *junk, int howto) 498{ 499 500 if (howto & RB_HALT) { 501 printf("\n"); 502 printf("The operating system has halted.\n"); 503 printf("Please press any key to reboot.\n\n"); 504 505 wdog_kern_pat(WD_TO_NEVER); 506 507 switch (cngetc()) { 508 case -1: /* No console, just die */ 509 cpu_halt(); 510 /* NOTREACHED */ 511 default: 512 howto &= ~RB_HALT; 513 break; 514 } 515 } 516} 517 518/* 519 * Check to see if the system paniced, pause and then reboot 520 * according to the specified delay. 521 */ 522static void 523shutdown_panic(void *junk, int howto) 524{ 525 int loop; 526 527 if (howto & RB_DUMP) { 528 if (panic_reboot_wait_time != 0) { 529 if (panic_reboot_wait_time != -1) { 530 printf("Automatic reboot in %d seconds - " 531 "press a key on the console to abort\n", 532 panic_reboot_wait_time); 533 for (loop = panic_reboot_wait_time * 10; 534 loop > 0; --loop) { 535 DELAY(1000 * 100); /* 1/10th second */ 536 /* Did user type a key? */ 537 if (cncheckc() != -1) 538 break; 539 } 540 if (!loop) 541 return; 542 } 543 } else { /* zero time specified - reboot NOW */ 544 return; 545 } 546 printf("--> Press a key on the console to reboot,\n"); 547 printf("--> or switch off the system now.\n"); 548 cngetc(); 549 } 550} 551 552/* 553 * Everything done, now reset 554 */ 555static void 556shutdown_reset(void *junk, int howto) 557{ 558 559 printf("Rebooting...\n"); 560 DELAY(1000000); /* wait 1 sec for printf's to complete and be read */ 561 562 /* 563 * Acquiring smp_ipi_mtx here has a double effect: 564 * - it disables interrupts avoiding CPU0 preemption 565 * by fast handlers (thus deadlocking against other CPUs) 566 * - it avoids deadlocks against smp_rendezvous() or, more 567 * generally, threads busy-waiting, with this spinlock held, 568 * and waiting for responses by threads on other CPUs 569 * (ie. smp_tlb_shootdown()). 570 * 571 * For the !SMP case it just needs to handle the former problem. 572 */ 573#ifdef SMP 574 mtx_lock_spin(&smp_ipi_mtx); 575#else 576 spinlock_enter(); 577#endif 578 579 /* cpu_boot(howto); */ /* doesn't do anything at the moment */ 580 cpu_reset(); 581 /* NOTREACHED */ /* assuming reset worked */ 582} 583 584#if defined(WITNESS) || defined(INVARIANT_SUPPORT) 585static int kassert_warn_only = 0; 586#ifdef KDB 587static int kassert_do_kdb = 0; 588#endif 589#ifdef KTR 590static int kassert_do_ktr = 0; 591#endif 592static int kassert_do_log = 1; 593static int kassert_log_pps_limit = 4; 594static int kassert_log_mute_at = 0; 595static int kassert_log_panic_at = 0; 596static int kassert_warnings = 0; 597 598SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW, NULL, "kassert options"); 599 600SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, CTLFLAG_RWTUN, 601 &kassert_warn_only, 0, 602 "KASSERT triggers a panic (1) or just a warning (0)"); 603 604#ifdef KDB 605SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, CTLFLAG_RWTUN, 606 &kassert_do_kdb, 0, "KASSERT will enter the debugger"); 607#endif 608 609#ifdef KTR 610SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, CTLFLAG_RWTUN, 611 &kassert_do_ktr, 0, 612 "KASSERT does a KTR, set this to the KTRMASK you want"); 613#endif 614 615SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, CTLFLAG_RWTUN, 616 &kassert_do_log, 0, "KASSERT triggers a panic (1) or just a warning (0)"); 617 618SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RWTUN, 619 &kassert_warnings, 0, "number of KASSERTs that have been triggered"); 620 621SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, CTLFLAG_RWTUN, 622 &kassert_log_panic_at, 0, "max number of KASSERTS before we will panic"); 623 624SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, CTLFLAG_RWTUN, 625 &kassert_log_pps_limit, 0, "limit number of log messages per second"); 626 627SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, CTLFLAG_RWTUN, 628 &kassert_log_mute_at, 0, "max number of KASSERTS to log"); 629 630static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS); 631 632SYSCTL_PROC(_debug_kassert, OID_AUTO, kassert, 633 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, NULL, 0, 634 kassert_sysctl_kassert, "I", "set to trigger a test kassert"); 635 636static int 637kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS) 638{ 639 int error, i; 640 641 error = sysctl_wire_old_buffer(req, sizeof(int)); 642 if (error == 0) { 643 i = 0; 644 error = sysctl_handle_int(oidp, &i, 0, req); 645 } 646 if (error != 0 || req->newptr == NULL) 647 return (error); 648 KASSERT(0, ("kassert_sysctl_kassert triggered kassert %d", i)); 649 return (0); 650} 651 652/* 653 * Called by KASSERT, this decides if we will panic 654 * or if we will log via printf and/or ktr. 655 */ 656void 657kassert_panic(const char *fmt, ...) 658{ 659 static char buf[256]; 660 va_list ap; 661 662 va_start(ap, fmt); 663 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 664 va_end(ap); 665 666 /* 667 * panic if we're not just warning, or if we've exceeded 668 * kassert_log_panic_at warnings. 669 */ 670 if (!kassert_warn_only || 671 (kassert_log_panic_at > 0 && 672 kassert_warnings >= kassert_log_panic_at)) { 673 va_start(ap, fmt); 674 vpanic(fmt, ap); 675 /* NORETURN */ 676 } 677#ifdef KTR 678 if (kassert_do_ktr) 679 CTR0(ktr_mask, buf); 680#endif /* KTR */ 681 /* 682 * log if we've not yet met the mute limit. 683 */ 684 if (kassert_do_log && 685 (kassert_log_mute_at == 0 || 686 kassert_warnings < kassert_log_mute_at)) { 687 static struct timeval lasterr; 688 static int curerr; 689 690 if (ppsratecheck(&lasterr, &curerr, kassert_log_pps_limit)) { 691 printf("KASSERT failed: %s\n", buf); 692 kdb_backtrace(); 693 } 694 } 695#ifdef KDB 696 if (kassert_do_kdb) { 697 kdb_enter(KDB_WHY_KASSERT, buf); 698 } 699#endif 700 atomic_add_int(&kassert_warnings, 1); 701} 702#endif 703 704/* 705 * Panic is called on unresolvable fatal errors. It prints "panic: mesg", 706 * and then reboots. If we are called twice, then we avoid trying to sync 707 * the disks as this often leads to recursive panics. 708 */ 709void 710panic(const char *fmt, ...) 711{ 712 va_list ap; 713 714 va_start(ap, fmt); 715 vpanic(fmt, ap); 716} 717 718void 719vpanic(const char *fmt, va_list ap) 720{ 721#ifdef SMP 722 cpuset_t other_cpus; 723#endif 724 struct thread *td = curthread; 725 int bootopt, newpanic; 726 static char buf[256]; 727 728 spinlock_enter(); 729 730#ifdef SMP 731 /* 732 * stop_cpus_hard(other_cpus) should prevent multiple CPUs from 733 * concurrently entering panic. Only the winner will proceed 734 * further. 735 */ 736 if (panicstr == NULL && !kdb_active) { 737 other_cpus = all_cpus; 738 CPU_CLR(PCPU_GET(cpuid), &other_cpus); 739 stop_cpus_hard(other_cpus); 740 } 741#endif 742 743 /* 744 * Ensure that the scheduler is stopped while panicking, even if panic 745 * has been entered from kdb. 746 */ 747 td->td_stopsched = 1; 748 749 bootopt = RB_AUTOBOOT; 750 newpanic = 0; 751 if (panicstr) 752 bootopt |= RB_NOSYNC; 753 else { 754 bootopt |= RB_DUMP; 755 panicstr = fmt; 756 newpanic = 1; 757 } 758 759 if (newpanic) { 760 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 761 panicstr = buf; 762 cngrab(); 763 printf("panic: %s\n", buf); 764 } else { 765 printf("panic: "); 766 vprintf(fmt, ap); 767 printf("\n"); 768 } 769#ifdef SMP 770 printf("cpuid = %d\n", PCPU_GET(cpuid)); 771#endif 772 773#ifdef KDB 774 if (newpanic && trace_on_panic) 775 kdb_backtrace(); 776 if (debugger_on_panic) 777 kdb_enter(KDB_WHY_PANIC, "panic"); 778#endif 779 /*thread_lock(td); */ 780 td->td_flags |= TDF_INPANIC; 781 /* thread_unlock(td); */ 782 if (!sync_on_panic) 783 bootopt |= RB_NOSYNC; 784 kern_reboot(bootopt); 785} 786 787/* 788 * Support for poweroff delay. 789 * 790 * Please note that setting this delay too short might power off your machine 791 * before the write cache on your hard disk has been flushed, leading to 792 * soft-updates inconsistencies. 793 */ 794#ifndef POWEROFF_DELAY 795# define POWEROFF_DELAY 5000 796#endif 797static int poweroff_delay = POWEROFF_DELAY; 798 799SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW, 800 &poweroff_delay, 0, "Delay before poweroff to write disk caches (msec)"); 801 802static void 803poweroff_wait(void *junk, int howto) 804{ 805 806 if (!(howto & RB_POWEROFF) || poweroff_delay <= 0) 807 return; 808 DELAY(poweroff_delay * 1000); 809} 810 811/* 812 * Some system processes (e.g. syncer) need to be stopped at appropriate 813 * points in their main loops prior to a system shutdown, so that they 814 * won't interfere with the shutdown process (e.g. by holding a disk buf 815 * to cause sync to fail). For each of these system processes, register 816 * shutdown_kproc() as a handler for one of shutdown events. 817 */ 818static int kproc_shutdown_wait = 60; 819SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW, 820 &kproc_shutdown_wait, 0, "Max wait time (sec) to stop for each process"); 821 822void 823kproc_shutdown(void *arg, int howto) 824{ 825 struct proc *p; 826 int error; 827 828 if (panicstr) 829 return; 830 831 p = (struct proc *)arg; 832 printf("Waiting (max %d seconds) for system process `%s' to stop... ", 833 kproc_shutdown_wait, p->p_comm); 834 error = kproc_suspend(p, kproc_shutdown_wait * hz); 835 836 if (error == EWOULDBLOCK) 837 printf("timed out\n"); 838 else 839 printf("done\n"); 840} 841 842void 843kthread_shutdown(void *arg, int howto) 844{ 845 struct thread *td; 846 int error; 847 848 if (panicstr) 849 return; 850 851 td = (struct thread *)arg; 852 printf("Waiting (max %d seconds) for system thread `%s' to stop... ", 853 kproc_shutdown_wait, td->td_name); 854 error = kthread_suspend(td, kproc_shutdown_wait * hz); 855 856 if (error == EWOULDBLOCK) 857 printf("timed out\n"); 858 else 859 printf("done\n"); 860} 861 862static char dumpdevname[sizeof(((struct cdev*)NULL)->si_name)]; 863SYSCTL_STRING(_kern_shutdown, OID_AUTO, dumpdevname, CTLFLAG_RD, 864 dumpdevname, 0, "Device for kernel dumps"); 865 866/* Registration of dumpers */ 867int 868set_dumper(struct dumperinfo *di, const char *devname, struct thread *td) 869{ 870 size_t wantcopy; 871 int error; 872 873 error = priv_check(td, PRIV_SETDUMPER); 874 if (error != 0) 875 return (error); 876 877 if (di == NULL) { 878 if (dumper.blockbuf != NULL) 879 free(dumper.blockbuf, M_DUMPER); 880 bzero(&dumper, sizeof(dumper)); 881 dumpdevname[0] = '\0'; 882 return (0); 883 } 884 if (dumper.dumper != NULL) 885 return (EBUSY); 886 dumper = *di; 887 wantcopy = strlcpy(dumpdevname, devname, sizeof(dumpdevname)); 888 if (wantcopy >= sizeof(dumpdevname)) { 889 printf("set_dumper: device name truncated from '%s' -> '%s'\n", 890 devname, dumpdevname); 891 } 892 dumper.blockbuf = malloc(di->blocksize, M_DUMPER, M_WAITOK | M_ZERO); 893 return (0); 894} 895 896/* Call dumper with bounds checking. */ 897int 898dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical, 899 off_t offset, size_t length) 900{ 901 902 if (length != 0 && (offset < di->mediaoffset || 903 offset - di->mediaoffset + length > di->mediasize)) { 904 printf("Attempt to write outside dump device boundaries.\n" 905 "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n", 906 (intmax_t)offset, (intmax_t)di->mediaoffset, 907 (uintmax_t)length, (intmax_t)di->mediasize); 908 return (ENOSPC); 909 } 910 return (di->dumper(di->priv, virtual, physical, offset, length)); 911} 912 913/* Call dumper with bounds checking. */ 914int 915dump_write_pad(struct dumperinfo *di, void *virtual, vm_offset_t physical, 916 off_t offset, size_t length, size_t *size) 917{ 918 char *temp; 919 int ret; 920 921 if (length > di->blocksize) 922 return (ENOMEM); 923 924 *size = di->blocksize; 925 if (length == di->blocksize) 926 temp = virtual; 927 else { 928 temp = di->blockbuf; 929 memset(temp + length, 0, di->blocksize - length); 930 memcpy(temp, virtual, length); 931 } 932 ret = dump_write(di, temp, physical, offset, *size); 933 934 return (ret); 935} 936 937 938void 939mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver, 940 uint64_t dumplen, uint32_t blksz) 941{ 942 size_t dstsize; 943 944 bzero(kdh, sizeof(*kdh)); 945 strlcpy(kdh->magic, magic, sizeof(kdh->magic)); 946 strlcpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture)); 947 kdh->version = htod32(KERNELDUMPVERSION); 948 kdh->architectureversion = htod32(archver); 949 kdh->dumplength = htod64(dumplen); 950 kdh->dumptime = htod64(time_second); 951 kdh->blocksize = htod32(blksz); 952 strlcpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname)); 953 dstsize = sizeof(kdh->versionstring); 954 if (strlcpy(kdh->versionstring, version, dstsize) >= dstsize) 955 kdh->versionstring[dstsize - 2] = '\n'; 956 if (panicstr != NULL) 957 strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring)); 958 kdh->parity = kerneldump_parity(kdh); 959} 960 961#ifdef DDB 962DB_SHOW_COMMAND(panic, db_show_panic) 963{ 964 965 if (panicstr == NULL) 966 db_printf("panicstr not set\n"); 967 else 968 db_printf("panic: %s\n", panicstr); 969} 970#endif 971