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/jail.h>
  54 #include <sys/kdb.h>
  55 #include <sys/kernel.h>
  56 #include <sys/kerneldump.h>
  57 #include <sys/kthread.h>
  58 #include <sys/malloc.h>
  59 #include <sys/mount.h>
  60 #include <sys/priv.h>
  61 #include <sys/proc.h>
  62 #include <sys/reboot.h>
  63 #include <sys/resourcevar.h>
  64 #include <sys/sched.h>
  65 #include <sys/smp.h>
  66 #include <sys/sysctl.h>
  67 #include <sys/sysproto.h>
  68 #include <sys/vnode.h>
  69 #include <sys/watchdog.h>
  70
  71 #include <ddb/ddb.h>
  72
  73 #include <machine/cpu.h>
  74 #include <machine/pcb.h>
  75 #include <machine/smp.h>
  76
  77 #include <security/mac/mac_framework.h>
  78
  79 #include <vm/vm.h>
  80 #include <vm/vm_object.h>
  81 #include <vm/vm_page.h>
  82 #include <vm/vm_pager.h>
  83 #include <vm/swap_pager.h>
  84
  85 #include <sys/signalvar.h>
  86
  87 #ifndef PANIC_REBOOT_WAIT_TIME
  88 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
  89 #endif
  90
  91 /*
  92  * Note that stdarg.h and the ANSI style va_start macro is used for both
  93  * ANSI and traditional C compilers.
  94  */
  95 #include <machine/stdarg.h>
  96
  97 #ifdef KDB
  98 #ifdef KDB_UNATTENDED
  99 int debugger_on_panic = 0;
 100 #else
 101 int debugger_on_panic = 1;
 102 #endif
 103 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW | CTLFLAG_TUN,
 104         &debugger_on_panic, 0, "Run debugger on kernel panic");
 105 TUNABLE_INT("debug.debugger_on_panic", &debugger_on_panic);
 106
 107 #ifdef KDB_TRACE
 108 static int trace_on_panic = 1;
 109 #else
 110 static int trace_on_panic = 0;
 111 #endif
 112 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW | CTLFLAG_TUN,
 113         &trace_on_panic, 0, "Print stack trace on kernel panic");
 114 TUNABLE_INT("debug.trace_on_panic", &trace_on_panic);
 115 #endif /* KDB */
 116
 117 static int sync_on_panic = 0;
 118 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW | CTLFLAG_TUN,
 119         &sync_on_panic, 0, "Do a sync before rebooting from a panic");
 120 TUNABLE_INT("kern.sync_on_panic", &sync_on_panic);
 121
 122 static int stop_scheduler_on_panic = 0;
 123 SYSCTL_INT(_kern, OID_AUTO, stop_scheduler_on_panic, CTLFLAG_RW | CTLFLAG_TUN,
 124     &stop_scheduler_on_panic, 0, "stop scheduler upon entering panic");
 125 TUNABLE_INT("kern.stop_scheduler_on_panic", &stop_scheduler_on_panic);
 126
 127 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
 128
 129 #ifndef DIAGNOSTIC
 130 static int show_busybufs;
 131 #else
 132 static int show_busybufs = 1;
 133 #endif
 134 SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
 135         &show_busybufs, 0, "");
 136
 137 /*
 138  * Variable panicstr contains argument to first call to panic; used as flag
 139  * to indicate that the kernel has already called panic.
 140  */
 141 const char *panicstr;
 142
 143 int dumping;                            /* system is dumping */
 144 int rebooting;                          /* system is rebooting */
 145 static struct dumperinfo dumper;        /* our selected dumper */
 146
 147 /* Context information for dump-debuggers. */
 148 static struct pcb dumppcb;              /* Registers. */
 149 lwpid_t dumptid;                        /* Thread ID. */
 150
 151 static void boot(int) __dead2;
 152 static void poweroff_wait(void *, int);
 153 static void shutdown_halt(void *junk, int howto);
 154 static void shutdown_panic(void *junk, int howto);
 155 static void shutdown_reset(void *junk, int howto);
 156
 157 /* register various local shutdown events */
 158 static void
 159 shutdown_conf(void *unused)
 160 {
 161
 162         EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
 163             SHUTDOWN_PRI_FIRST);
 164         EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
 165             SHUTDOWN_PRI_LAST + 100);
 166         EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
 167             SHUTDOWN_PRI_LAST + 100);
 168         EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
 169             SHUTDOWN_PRI_LAST + 200);
 170 }
 171
 172 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL);
 173
 174 /*
 175  * The system call that results in a reboot.
 176  */
 177 /* ARGSUSED */
 178 int
 179 reboot(struct thread *td, struct reboot_args *uap)
 180 {
 181         int error;
 182
 183         error = 0;
 184 #ifdef MAC
 185         error = mac_system_check_reboot(td->td_ucred, uap->opt);
 186 #endif
 187         if (error == 0)
 188                 error = priv_check(td, PRIV_REBOOT);
 189         if (error == 0) {
 190                 mtx_lock(&Giant);
 191                 boot(uap->opt);
 192                 mtx_unlock(&Giant);
 193         }
 194         return (error);
 195 }
 196
 197 /*
 198  * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
 199  */
 200 static int shutdown_howto = 0;
 201
 202 void
 203 shutdown_nice(int howto)
 204 {
 205
 206         shutdown_howto = howto;
 207
 208         /* Send a signal to init(8) and have it shutdown the world */
 209         if (initproc != NULL) {
 210                 PROC_LOCK(initproc);
 211                 psignal(initproc, SIGINT);
 212                 PROC_UNLOCK(initproc);
 213         } else {
 214                 /* No init(8) running, so simply reboot */
 215                 boot(RB_NOSYNC);
 216         }
 217         return;
 218 }
 219 static int      waittime = -1;
 220
 221 static void
 222 print_uptime(void)
 223 {
 224         int f;
 225         struct timespec ts;
 226
 227         getnanouptime(&ts);
 228         printf("Uptime: ");
 229         f = 0;
 230         if (ts.tv_sec >= 86400) {
 231                 printf("%ldd", (long)ts.tv_sec / 86400);
 232                 ts.tv_sec %= 86400;
 233                 f = 1;
 234         }
 235         if (f || ts.tv_sec >= 3600) {
 236                 printf("%ldh", (long)ts.tv_sec / 3600);
 237                 ts.tv_sec %= 3600;
 238                 f = 1;
 239         }
 240         if (f || ts.tv_sec >= 60) {
 241                 printf("%ldm", (long)ts.tv_sec / 60);
 242                 ts.tv_sec %= 60;
 243                 f = 1;
 244         }
 245         printf("%lds\n", (long)ts.tv_sec);
 246 }
 247
 248 static void
 249 doadump(void)
 250 {
 251
 252         /*
 253          * Sometimes people have to call this from the kernel debugger.
 254          * (if 'panic' can not dump)
 255          * Give them a clue as to why they can't dump.
 256          */
 257         if (dumper.dumper == NULL) {
 258                 printf("Cannot dump. Device not defined or unavailable.\n");
 259                 return;
 260         }
 261
 262         savectx(&dumppcb);
 263         dumptid = curthread->td_tid;
 264         dumping++;
 265 #ifdef DDB
 266         if (textdump_pending)
 267                 textdump_dumpsys(&dumper);
 268         else
 269 #endif
 270                 dumpsys(&dumper);
 271         dumping--;
 272 }
 273
 274 static int
 275 isbufbusy(struct buf *bp)
 276 {
 277         if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
 278             BUF_ISLOCKED(bp)) ||
 279             ((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
 280                 return (1);
 281         return (0);
 282 }
 283
 284 /*
 285  * Shutdown the system cleanly to prepare for reboot, halt, or power off.
 286  */
 287 static void
 288 boot(int howto)
 289 {
 290         static int first_buf_printf = 1;
 291
 292 #if defined(SMP)
 293         /*
 294          * Bind us to CPU 0 so that all shutdown code runs there.  Some
 295          * systems don't shutdown properly (i.e., ACPI power off) if we
 296          * run on another processor.
 297          */
 298         if (!SCHEDULER_STOPPED()) {
 299                 thread_lock(curthread);
 300                 sched_bind(curthread, 0);
 301                 thread_unlock(curthread);
 302                 KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
 303         }
 304 #endif
 305         /* We're in the process of rebooting. */
 306         rebooting = 1;
 307
 308         /* collect extra flags that shutdown_nice might have set */
 309         howto |= shutdown_howto;
 310
 311         /* We are out of the debugger now. */
 312         kdb_active = 0;
 313
 314         /*
 315          * Do any callouts that should be done BEFORE syncing the filesystems.
 316          */
 317         EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
 318
 319         /*
 320          * Now sync filesystems
 321          */
 322         if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
 323                 register struct buf *bp;
 324                 int iter, nbusy, pbusy;
 325 #ifndef PREEMPTION
 326                 int subiter;
 327 #endif
 328
 329                 waittime = 0;
 330
 331                 wdog_kern_pat(WD_LASTVAL);
 332                 sync(curthread, NULL);
 333
 334                 /*
 335                  * With soft updates, some buffers that are
 336                  * written will be remarked as dirty until other
 337                  * buffers are written.
 338                  */
 339                 for (iter = pbusy = 0; iter < 20; iter++) {
 340                         nbusy = 0;
 341                         for (bp = &buf[nbuf]; --bp >= buf; )
 342                                 if (isbufbusy(bp))
 343                                         nbusy++;
 344                         if (nbusy == 0) {
 345                                 if (first_buf_printf)
 346                                         printf("All buffers synced.");
 347                                 break;
 348                         }
 349                         if (first_buf_printf) {
 350                                 printf("Syncing disks, buffers remaining... ");
 351                                 first_buf_printf = 0;
 352                         }
 353                         printf("%d ", nbusy);
 354                         if (nbusy < pbusy)
 355                                 iter = 0;
 356                         pbusy = nbusy;
 357
 358                         wdog_kern_pat(WD_LASTVAL);
 359                         sync(curthread, NULL);
 360
 361 #ifdef PREEMPTION
 362                         /*
 363                          * Drop Giant and spin for a while to allow
 364                          * interrupt threads to run.
 365                          */
 366                         DROP_GIANT();
 367                         DELAY(50000 * iter);
 368                         PICKUP_GIANT();
 369 #else
 370                         /*
 371                          * Drop Giant and context switch several times to
 372                          * allow interrupt threads to run.
 373                          */
 374                         DROP_GIANT();
 375                         for (subiter = 0; subiter < 50 * iter; subiter++) {
 376                                 thread_lock(curthread);
 377                                 mi_switch(SW_VOL, NULL);
 378                                 thread_unlock(curthread);
 379                                 DELAY(1000);
 380                         }
 381                         PICKUP_GIANT();
 382 #endif
 383                 }
 384                 printf("\n");
 385                 /*
 386                  * Count only busy local buffers to prevent forcing
 387                  * a fsck if we're just a client of a wedged NFS server
 388                  */
 389                 nbusy = 0;
 390                 for (bp = &buf[nbuf]; --bp >= buf; ) {
 391                         if (isbufbusy(bp)) {
 392 #if 0
 393 /* XXX: This is bogus.  We should probably have a BO_REMOTE flag instead */
 394                                 if (bp->b_dev == NULL) {
 395                                         TAILQ_REMOVE(&mountlist,
 396                                             bp->b_vp->v_mount, mnt_list);
 397                                         continue;
 398                                 }
 399 #endif
 400                                 nbusy++;
 401                                 if (show_busybufs > 0) {
 402                                         printf(
 403             "%d: buf:%p, vnode:%p, flags:%0x, blkno:%jd, lblkno:%jd, buflock:",
 404                                             nbusy, bp, bp->b_vp, bp->b_flags,
 405                                             (intmax_t)bp->b_blkno,
 406                                             (intmax_t)bp->b_lblkno);
 407                                         BUF_LOCKPRINTINFO(bp);
 408                                         if (show_busybufs > 1)
 409                                                 vn_printf(bp->b_vp,
 410                                                     "vnode content: ");
 411                                 }
 412                         }
 413                 }
 414                 if (nbusy) {
 415                         /*
 416                          * Failed to sync all blocks. Indicate this and don't
 417                          * unmount filesystems (thus forcing an fsck on reboot).
 418                          */
 419                         printf("Giving up on %d buffers\n", nbusy);
 420                         DELAY(5000000); /* 5 seconds */
 421                 } else {
 422                         if (!first_buf_printf)
 423                                 printf("Final sync complete\n");
 424                         /*
 425                          * Unmount filesystems
 426                          */
 427                         if (panicstr == 0)
 428                                 vfs_unmountall();
 429                 }
 430                 swapoff_all();
 431                 DELAY(100000);          /* wait for console output to finish */
 432         }
 433
 434         print_uptime();
 435
 436         /*
 437          * Ok, now do things that assume all filesystem activity has
 438          * been completed.
 439          */
 440         EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
 441
 442         if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
 443                 doadump();
 444
 445         /* Now that we're going to really halt the system... */
 446         EVENTHANDLER_INVOKE(shutdown_final, howto);
 447
 448         for(;;) ;       /* safety against shutdown_reset not working */
 449         /* NOTREACHED */
 450 }
 451
 452 /*
 453  * If the shutdown was a clean halt, behave accordingly.
 454  */
 455 static void
 456 shutdown_halt(void *junk, int howto)
 457 {
 458
 459         if (howto & RB_HALT) {
 460                 printf("\n");
 461                 printf("The operating system has halted.\n");
 462                 printf("Please press any key to reboot.\n\n");
 463                 switch (cngetc()) {
 464                 case -1:                /* No console, just die */
 465                         cpu_halt();
 466                         /* NOTREACHED */
 467                 default:
 468                         howto &= ~RB_HALT;
 469                         break;
 470                 }
 471         }
 472 }
 473
 474 /*
 475  * Check to see if the system paniced, pause and then reboot
 476  * according to the specified delay.
 477  */
 478 static void
 479 shutdown_panic(void *junk, int howto)
 480 {
 481         int loop;
 482
 483         if (howto & RB_DUMP) {
 484                 if (PANIC_REBOOT_WAIT_TIME != 0) {
 485                         if (PANIC_REBOOT_WAIT_TIME != -1) {
 486                                 printf("Automatic reboot in %d seconds - "
 487                                        "press a key on the console to abort\n",
 488                                         PANIC_REBOOT_WAIT_TIME);
 489                                 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
 490                                      loop > 0; --loop) {
 491                                         DELAY(1000 * 100); /* 1/10th second */
 492                                         /* Did user type a key? */
 493                                         if (cncheckc() != -1)
 494                                                 break;
 495                                 }
 496                                 if (!loop)
 497                                         return;
 498                         }
 499                 } else { /* zero time specified - reboot NOW */
 500                         return;
 501                 }
 502                 printf("--> Press a key on the console to reboot,\n");
 503                 printf("--> or switch off the system now.\n");
 504                 cngetc();
 505         }
 506 }
 507
 508 /*
 509  * Everything done, now reset
 510  */
 511 static void
 512 shutdown_reset(void *junk, int howto)
 513 {
 514
 515         printf("Rebooting...\n");
 516         DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
 517
 518         /*
 519          * Acquiring smp_ipi_mtx here has a double effect:
 520          * - it disables interrupts avoiding CPU0 preemption
 521          *   by fast handlers (thus deadlocking  against other CPUs)
 522          * - it avoids deadlocks against smp_rendezvous() or, more
 523          *   generally, threads busy-waiting, with this spinlock held,
 524          *   and waiting for responses by threads on other CPUs
 525          *   (ie. smp_tlb_shootdown()).
 526          *
 527          * For the !SMP case it just needs to handle the former problem.
 528          */
 529 #ifdef SMP
 530         mtx_lock_spin(&smp_ipi_mtx);
 531 #else
 532         spinlock_enter();
 533 #endif
 534
 535         /* cpu_boot(howto); */ /* doesn't do anything at the moment */
 536         cpu_reset();
 537         /* NOTREACHED */ /* assuming reset worked */
 538 }
 539
 540 /*
 541  * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
 542  * and then reboots.  If we are called twice, then we avoid trying to sync
 543  * the disks as this often leads to recursive panics.
 544  */
 545 void
 546 panic(const char *fmt, ...)
 547 {
 548 #ifdef SMP
 549         static volatile u_int panic_cpu = NOCPU;
 550 #endif
 551         struct thread *td = curthread;
 552         int bootopt, newpanic;
 553         va_list ap;
 554         static char buf[256];
 555
 556         if (stop_scheduler_on_panic)
 557                 spinlock_enter();
 558         else
 559                 critical_enter();
 560
 561 #ifdef SMP
 562         /*
 563          * We don't want multiple CPU's to panic at the same time, so we
 564          * use panic_cpu as a simple spinlock.  We have to keep checking
 565          * panic_cpu if we are spinning in case the panic on the first
 566          * CPU is canceled.
 567          */
 568         if (panic_cpu != PCPU_GET(cpuid))
 569                 while (atomic_cmpset_int(&panic_cpu, NOCPU,
 570                     PCPU_GET(cpuid)) == 0)
 571                         while (panic_cpu != NOCPU)
 572                                 ; /* nothing */
 573
 574         if (stop_scheduler_on_panic) {
 575                 if (panicstr == NULL && !kdb_active)
 576                         stop_cpus_hard(PCPU_GET(other_cpus));
 577
 578                 /*
 579                  * We set stop_scheduler here and not in the block above,
 580                  * because we want to ensure that if panic has been called and
 581                  * stop_scheduler_on_panic is true, then stop_scheduler will
 582                  * always be set.  Even if panic has been entered from kdb.
 583                  */
 584                 td->td_stopsched = 1;
 585         }
 586 #endif
 587
 588         bootopt = RB_AUTOBOOT | RB_DUMP;
 589         newpanic = 0;
 590         if (panicstr)
 591                 bootopt |= RB_NOSYNC;
 592         else {
 593                 panicstr = fmt;
 594                 newpanic = 1;
 595         }
 596
 597         va_start(ap, fmt);
 598         if (newpanic) {
 599                 (void)vsnprintf(buf, sizeof(buf), fmt, ap);
 600                 panicstr = buf;
 601                 printf("panic: %s\n", buf);
 602         } else {
 603                 printf("panic: ");
 604                 vprintf(fmt, ap);
 605                 printf("\n");
 606         }
 607         va_end(ap);
 608 #ifdef SMP
 609         printf("cpuid = %d\n", PCPU_GET(cpuid));
 610 #endif
 611
 612 #ifdef KDB
 613         if (newpanic && trace_on_panic)
 614                 kdb_backtrace();
 615         if (debugger_on_panic)
 616                 kdb_enter(KDB_WHY_PANIC, "panic");
 617 #ifdef RESTARTABLE_PANICS
 618         /* See if the user aborted the panic, in which case we continue. */
 619         if (panicstr == NULL) {
 620 #ifdef SMP
 621                 atomic_store_rel_int(&panic_cpu, NOCPU);
 622 #endif
 623                 return;
 624         }
 625 #endif
 626 #endif
 627         /*thread_lock(td); */
 628         td->td_flags |= TDF_INPANIC;
 629         /* thread_unlock(td); */
 630         if (!sync_on_panic)
 631                 bootopt |= RB_NOSYNC;
 632         if (!stop_scheduler_on_panic)
 633                 critical_exit();
 634         boot(bootopt);
 635 }
 636
 637 /*
 638  * Support for poweroff delay.
 639  */
 640 #ifndef POWEROFF_DELAY
 641 # define POWEROFF_DELAY 5000
 642 #endif
 643 static int poweroff_delay = POWEROFF_DELAY;
 644
 645 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
 646         &poweroff_delay, 0, "");
 647
 648 static void
 649 poweroff_wait(void *junk, int howto)
 650 {
 651
 652         if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
 653                 return;
 654         DELAY(poweroff_delay * 1000);
 655 }
 656
 657 /*
 658  * Some system processes (e.g. syncer) need to be stopped at appropriate
 659  * points in their main loops prior to a system shutdown, so that they
 660  * won't interfere with the shutdown process (e.g. by holding a disk buf
 661  * to cause sync to fail).  For each of these system processes, register
 662  * shutdown_kproc() as a handler for one of shutdown events.
 663  */
 664 static int kproc_shutdown_wait = 60;
 665 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
 666     &kproc_shutdown_wait, 0, "");
 667
 668 void
 669 kproc_shutdown(void *arg, int howto)
 670 {
 671         struct proc *p;
 672         char procname[MAXCOMLEN + 1];
 673         int error;
 674
 675         if (panicstr)
 676                 return;
 677
 678         p = (struct proc *)arg;
 679         strlcpy(procname, p->p_comm, sizeof(procname));
 680         printf("Waiting (max %d seconds) for system process `%s' to stop...",
 681             kproc_shutdown_wait, procname);
 682         error = kproc_suspend(p, kproc_shutdown_wait * hz);
 683
 684         if (error == EWOULDBLOCK)
 685                 printf("timed out\n");
 686         else
 687                 printf("done\n");
 688 }
 689
 690 void
 691 kthread_shutdown(void *arg, int howto)
 692 {
 693         struct thread *td;
 694         char procname[MAXCOMLEN + 1];
 695         int error;
 696
 697         if (panicstr)
 698                 return;
 699
 700         td = (struct thread *)arg;
 701         strlcpy(procname, td->td_name, sizeof(procname));
 702         printf("Waiting (max %d seconds) for system thread `%s' to stop...",
 703             kproc_shutdown_wait, procname);
 704         error = kthread_suspend(td, kproc_shutdown_wait * hz);
 705
 706         if (error == EWOULDBLOCK)
 707                 printf("timed out\n");
 708         else
 709                 printf("done\n");
 710 }
 711
 712 /* Registration of dumpers */
 713 int
 714 set_dumper(struct dumperinfo *di)
 715 {
 716
 717         if (di == NULL) {
 718                 bzero(&dumper, sizeof dumper);
 719                 return (0);
 720         }
 721         if (dumper.dumper != NULL)
 722                 return (EBUSY);
 723         dumper = *di;
 724         return (0);
 725 }
 726
 727 /* Call dumper with bounds checking. */
 728 int
 729 dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
 730     off_t offset, size_t length)
 731 {
 732
 733         if (length != 0 && (offset < di->mediaoffset ||
 734             offset - di->mediaoffset + length > di->mediasize)) {
 735                 printf("Attempt to write outside dump device boundaries.\n"
 736             "offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n",
 737                     (intmax_t)offset, (intmax_t)di->mediaoffset,
 738                     (uintmax_t)length, (intmax_t)di->mediasize);
 739                 return (ENOSPC);
 740         }
 741         return (di->dumper(di->priv, virtual, physical, offset, length));
 742 }
 743
 744 void
 745 mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
 746     uint64_t dumplen, uint32_t blksz)
 747 {
 748
 749         bzero(kdh, sizeof(*kdh));
 750         strncpy(kdh->magic, magic, sizeof(kdh->magic));
 751         strncpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
 752         kdh->version = htod32(KERNELDUMPVERSION);
 753         kdh->architectureversion = htod32(archver);
 754         kdh->dumplength = htod64(dumplen);
 755         kdh->dumptime = htod64(time_second);
 756         kdh->blocksize = htod32(blksz);
 757         strncpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
 758         strncpy(kdh->versionstring, version, sizeof(kdh->versionstring));
 759         if (panicstr != NULL)
 760                 strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
 761         kdh->parity = kerneldump_parity(kdh);
 762 }