sys/kern/kern_shutdown.c

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