kern_shutdown.c

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    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  * 3. All advertising materials mentioning features or use of this software
   19  *    must display the following acknowledgement:
   20  *      This product includes software developed by the University of
   21  *      California, Berkeley and its contributors.
   22  * 4. Neither the name of the University nor the names of its contributors
   23  *    may be used to endorse or promote products derived from this software
   24  *    without specific prior written permission.
   25  *
   26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   36  * SUCH DAMAGE.
   37  *
   38  *      @(#)kern_shutdown.c     8.3 (Berkeley) 1/21/94
   39  * $FreeBSD: releng/5.1/sys/kern/kern_shutdown.c 113633 2003-04-17 22:29:23Z jhb $
   40  */
   41 
   42 #include "opt_ddb.h"
   43 #include "opt_ddb_trace.h"
   44 #include "opt_ddb_unattended.h"
   45 #include "opt_hw_wdog.h"
   46 #include "opt_mac.h"
   47 #include "opt_panic.h"
   48 #include "opt_show_busybufs.h"
   49 
   50 #include <sys/param.h>
   51 #include <sys/systm.h>
   52 #include <sys/bio.h>
   53 #include <sys/buf.h>
   54 #include <sys/conf.h>
   55 #include <sys/cons.h>
   56 #include <sys/eventhandler.h>
   57 #include <sys/kernel.h>
   58 #include <sys/kthread.h>
   59 #include <sys/mac.h>
   60 #include <sys/malloc.h>
   61 #include <sys/mount.h>
   62 #include <sys/proc.h>
   63 #include <sys/reboot.h>
   64 #include <sys/resourcevar.h>
   65 #include <sys/smp.h>            /* smp_active */
   66 #include <sys/sysctl.h>
   67 #include <sys/sysproto.h>
   68 #include <sys/vnode.h>
   69 
   70 #include <machine/pcb.h>
   71 #include <machine/md_var.h>
   72 #include <machine/smp.h>
   73 
   74 #include <sys/signalvar.h>
   75 #ifdef DDB
   76 #include <ddb/ddb.h>
   77 #endif
   78 
   79 #ifndef PANIC_REBOOT_WAIT_TIME
   80 #define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
   81 #endif
   82 
   83 /*
   84  * Note that stdarg.h and the ANSI style va_start macro is used for both
   85  * ANSI and traditional C compilers.
   86  */
   87 #include <machine/stdarg.h>
   88 
   89 #ifdef DDB
   90 #ifdef DDB_UNATTENDED
   91 int debugger_on_panic = 0;
   92 #else
   93 int debugger_on_panic = 1;
   94 #endif
   95 SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
   96         &debugger_on_panic, 0, "Run debugger on kernel panic");
   97 
   98 #ifdef DDB_TRACE
   99 int trace_on_panic = 1;
  100 #else
  101 int trace_on_panic = 0;
  102 #endif
  103 SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
  104         &trace_on_panic, 0, "Print stack trace on kernel panic");
  105 #endif
  106 
  107 int sync_on_panic = 1;
  108 SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
  109         &sync_on_panic, 0, "Do a sync before rebooting from a panic");
  110 
  111 SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
  112 
  113 #ifdef  HW_WDOG
  114 /*
  115  * If there is a hardware watchdog, point this at the function needed to
  116  * hold it off.
  117  * It's needed when the kernel needs to do some lengthy operations.
  118  * e.g. in wd.c when dumping core.. It's most annoying to have
  119  * your precious core-dump only half written because the wdog kicked in.
  120  */
  121 watchdog_tickle_fn wdog_tickler = NULL;
  122 #endif  /* HW_WDOG */
  123 
  124 /*
  125  * Variable panicstr contains argument to first call to panic; used as flag
  126  * to indicate that the kernel has already called panic.
  127  */
  128 const char *panicstr;
  129 
  130 int dumping;                            /* system is dumping */
  131 static struct dumperinfo dumper;        /* our selected dumper */
  132 static struct pcb dumppcb;              /* "You Are Here" sign for dump-debuggers */
  133 
  134 static void boot(int) __dead2;
  135 static void poweroff_wait(void *, int);
  136 static void shutdown_halt(void *junk, int howto);
  137 static void shutdown_panic(void *junk, int howto);
  138 static void shutdown_reset(void *junk, int howto);
  139 
  140 /* register various local shutdown events */
  141 static void
  142 shutdown_conf(void *unused)
  143 {
  144 
  145         EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
  146             SHUTDOWN_PRI_FIRST);
  147         EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
  148             SHUTDOWN_PRI_LAST + 100);
  149         EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
  150             SHUTDOWN_PRI_LAST + 100);
  151         EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
  152             SHUTDOWN_PRI_LAST + 200);
  153 }
  154 
  155 SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL)
  156 
  157 /*
  158  * The system call that results in a reboot
  159  *
  160  * MPSAFE
  161  */
  162 /* ARGSUSED */
  163 int
  164 reboot(struct thread *td, struct reboot_args *uap)
  165 {
  166         int error;
  167 
  168         error = 0;
  169 #ifdef MAC
  170         error = mac_check_system_reboot(td->td_ucred, uap->opt);
  171 #endif
  172         if (error == 0)
  173                 error = suser(td);
  174         if (error == 0) {
  175                 mtx_lock(&Giant);
  176                 boot(uap->opt);
  177                 mtx_unlock(&Giant);
  178         }
  179         return (error);
  180 }
  181 
  182 /*
  183  * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
  184  */
  185 static int shutdown_howto = 0;
  186 
  187 void
  188 shutdown_nice(int howto)
  189 {
  190 
  191         shutdown_howto = howto;
  192 
  193         /* Send a signal to init(8) and have it shutdown the world */
  194         if (initproc != NULL) {
  195                 PROC_LOCK(initproc);
  196                 psignal(initproc, SIGINT);
  197                 PROC_UNLOCK(initproc);
  198         } else {
  199                 /* No init(8) running, so simply reboot */
  200                 boot(RB_NOSYNC);
  201         }
  202         return;
  203 }
  204 static int      waittime = -1;
  205 
  206 static void
  207 print_uptime(void)
  208 {
  209         int f;
  210         struct timespec ts;
  211 
  212         getnanouptime(&ts);
  213         printf("Uptime: ");
  214         f = 0;
  215         if (ts.tv_sec >= 86400) {
  216                 printf("%ldd", (long)ts.tv_sec / 86400);
  217                 ts.tv_sec %= 86400;
  218                 f = 1;
  219         }
  220         if (f || ts.tv_sec >= 3600) {
  221                 printf("%ldh", (long)ts.tv_sec / 3600);
  222                 ts.tv_sec %= 3600;
  223                 f = 1;
  224         }
  225         if (f || ts.tv_sec >= 60) {
  226                 printf("%ldm", (long)ts.tv_sec / 60);
  227                 ts.tv_sec %= 60;
  228                 f = 1;
  229         }
  230         printf("%lds\n", (long)ts.tv_sec);
  231 }
  232 
  233 static void
  234 doadump(void)
  235 {
  236 
  237         savectx(&dumppcb);
  238         dumping++;
  239         dumpsys(&dumper);
  240 }
  241 
  242 /*
  243  *  Go through the rigmarole of shutting down..
  244  * this used to be in machdep.c but I'll be dammned if I could see
  245  * anything machine dependant in it.
  246  */
  247 static void
  248 boot(int howto)
  249 {
  250 
  251         /* collect extra flags that shutdown_nice might have set */
  252         howto |= shutdown_howto;
  253 
  254 #ifdef DDB
  255         /* We are out of the debugger now. */
  256         db_active = 0;
  257 #endif
  258 
  259 #ifdef SMP
  260         if (smp_active)
  261                 printf("boot() called on cpu#%d\n", PCPU_GET(cpuid));
  262 #endif
  263         /*
  264          * Do any callouts that should be done BEFORE syncing the filesystems.
  265          */
  266         EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
  267 
  268         /* 
  269          * Now sync filesystems
  270          */
  271         if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
  272                 register struct buf *bp;
  273                 int iter, nbusy, pbusy;
  274                 int subiter;
  275 
  276                 waittime = 0;
  277                 printf("\nsyncing disks, buffers remaining... ");
  278 
  279                 sync(&thread0, NULL);
  280 
  281                 /*
  282                  * With soft updates, some buffers that are
  283                  * written will be remarked as dirty until other
  284                  * buffers are written.
  285                  */
  286                 for (iter = pbusy = 0; iter < 20; iter++) {
  287                         nbusy = 0;
  288                         for (bp = &buf[nbuf]; --bp >= buf; ) {
  289                                 if ((bp->b_flags & B_INVAL) == 0 &&
  290                                     BUF_REFCNT(bp) > 0) {
  291                                         nbusy++;
  292                                 } else if ((bp->b_flags & (B_DELWRI | B_INVAL))
  293                                                 == B_DELWRI) {
  294                                         /* bawrite(bp);*/
  295                                         nbusy++;
  296                                 }
  297                         }
  298                         if (nbusy == 0)
  299                                 break;
  300                         printf("%d ", nbusy);
  301                         if (nbusy < pbusy)
  302                                 iter = 0;
  303                         pbusy = nbusy;
  304                         sync(&thread0, NULL);
  305                         if (curthread != NULL) {
  306                                 DROP_GIANT();
  307                                 for (subiter = 0; subiter < 50 * iter; subiter++) {
  308                                         mtx_lock_spin(&sched_lock);
  309                                         curthread->td_proc->p_stats->p_ru.ru_nvcsw++;
  310                                         mi_switch(); /* Allow interrupt threads to run */
  311                                         mtx_unlock_spin(&sched_lock);
  312                                         DELAY(1000);
  313                                 }
  314                                 PICKUP_GIANT();
  315                         } else
  316                         DELAY(50000 * iter);
  317                 }
  318                 printf("\n");
  319                 /*
  320                  * Count only busy local buffers to prevent forcing 
  321                  * a fsck if we're just a client of a wedged NFS server
  322                  */
  323                 nbusy = 0;
  324                 for (bp = &buf[nbuf]; --bp >= buf; ) {
  325                         if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
  326                             ((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
  327                                 if (bp->b_dev == NODEV) {
  328                                         TAILQ_REMOVE(&mountlist,
  329                                             bp->b_vp->v_mount, mnt_list);
  330                                         continue;
  331                                 }
  332                                 nbusy++;
  333 #if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
  334                                 printf(
  335                             "%d: dev:%s, flags:%0x, blkno:%ld, lblkno:%ld\n",
  336                                     nbusy, devtoname(bp->b_dev),
  337                                     bp->b_flags, (long)bp->b_blkno,
  338                                     (long)bp->b_lblkno);
  339 #endif
  340                         }
  341                 }
  342                 if (nbusy) {
  343                         /*
  344                          * Failed to sync all blocks. Indicate this and don't
  345                          * unmount filesystems (thus forcing an fsck on reboot).
  346                          */
  347                         printf("giving up on %d buffers\n", nbusy);
  348                         DELAY(5000000); /* 5 seconds */
  349                 } else {
  350                         printf("done\n");
  351                         /*
  352                          * Unmount filesystems
  353                          */
  354                         if (panicstr == 0)
  355                                 vfs_unmountall();
  356                 }
  357                 DELAY(100000);          /* wait for console output to finish */
  358         }
  359 
  360         print_uptime();
  361 
  362         /*
  363          * Ok, now do things that assume all filesystem activity has
  364          * been completed.
  365          */
  366         EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
  367         splhigh();
  368         if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP &&
  369             !cold && dumper.dumper != NULL && !dumping) 
  370                 doadump();
  371 
  372         /* Now that we're going to really halt the system... */
  373         EVENTHANDLER_INVOKE(shutdown_final, howto);
  374 
  375         for(;;) ;       /* safety against shutdown_reset not working */
  376         /* NOTREACHED */
  377 }
  378 
  379 /*
  380  * If the shutdown was a clean halt, behave accordingly.
  381  */
  382 static void
  383 shutdown_halt(void *junk, int howto)
  384 {
  385 
  386         if (howto & RB_HALT) {
  387                 printf("\n");
  388                 printf("The operating system has halted.\n");
  389                 printf("Please press any key to reboot.\n\n");
  390                 switch (cngetc()) {
  391                 case -1:                /* No console, just die */
  392                         cpu_halt();
  393                         /* NOTREACHED */
  394                 default:
  395                         howto &= ~RB_HALT;
  396                         break;
  397                 }
  398         }
  399 }
  400 
  401 /*
  402  * Check to see if the system paniced, pause and then reboot
  403  * according to the specified delay.
  404  */
  405 static void
  406 shutdown_panic(void *junk, int howto)
  407 {
  408         int loop;
  409 
  410         if (howto & RB_DUMP) {
  411                 if (PANIC_REBOOT_WAIT_TIME != 0) {
  412                         if (PANIC_REBOOT_WAIT_TIME != -1) {
  413                                 printf("Automatic reboot in %d seconds - "
  414                                        "press a key on the console to abort\n",
  415                                         PANIC_REBOOT_WAIT_TIME);
  416                                 for (loop = PANIC_REBOOT_WAIT_TIME * 10;
  417                                      loop > 0; --loop) {
  418                                         DELAY(1000 * 100); /* 1/10th second */
  419                                         /* Did user type a key? */
  420                                         if (cncheckc() != -1)
  421                                                 break;
  422                                 }
  423                                 if (!loop)
  424                                         return;
  425                         }
  426                 } else { /* zero time specified - reboot NOW */
  427                         return;
  428                 }
  429                 printf("--> Press a key on the console to reboot,\n");
  430                 printf("--> or switch off the system now.\n");
  431                 cngetc();
  432         }
  433 }
  434 
  435 /*
  436  * Everything done, now reset
  437  */
  438 static void
  439 shutdown_reset(void *junk, int howto)
  440 {
  441 
  442         printf("Rebooting...\n");
  443         DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
  444         /* cpu_boot(howto); */ /* doesn't do anything at the moment */
  445         cpu_reset();
  446         /* NOTREACHED */ /* assuming reset worked */
  447 }
  448 
  449 /*
  450  * Print a backtrace if we can.
  451  */
  452 
  453 void
  454 backtrace(void)
  455 {
  456 
  457 #ifdef DDB
  458         printf("Stack backtrace:\n");
  459         db_print_backtrace();
  460 #else
  461         printf("Sorry, need DDB option to print backtrace");
  462 #endif
  463 }
  464 
  465 #ifdef SMP
  466 static u_int panic_cpu = NOCPU;
  467 #endif
  468 
  469 /*
  470  * Panic is called on unresolvable fatal errors.  It prints "panic: mesg",
  471  * and then reboots.  If we are called twice, then we avoid trying to sync
  472  * the disks as this often leads to recursive panics.
  473  *
  474  * MPSAFE
  475  */
  476 void
  477 panic(const char *fmt, ...)
  478 {
  479         struct thread *td = curthread;
  480         int bootopt, newpanic;
  481         va_list ap;
  482         static char buf[256];
  483 
  484 #ifdef SMP
  485         /*
  486          * We don't want multiple CPU's to panic at the same time, so we
  487          * use panic_cpu as a simple spinlock.  We have to keep checking
  488          * panic_cpu if we are spinning in case the panic on the first
  489          * CPU is canceled.
  490          */
  491         if (panic_cpu != PCPU_GET(cpuid))
  492                 while (atomic_cmpset_int(&panic_cpu, NOCPU,
  493                     PCPU_GET(cpuid)) == 0)
  494                         while (panic_cpu != NOCPU)
  495                                 ; /* nothing */
  496 #endif
  497 
  498         bootopt = RB_AUTOBOOT | RB_DUMP;
  499         newpanic = 0;
  500         if (panicstr)
  501                 bootopt |= RB_NOSYNC;
  502         else {
  503                 panicstr = fmt;
  504                 newpanic = 1;
  505         }
  506 
  507         va_start(ap, fmt);
  508         (void)vsnprintf(buf, sizeof(buf), fmt, ap);
  509         if (panicstr == fmt)
  510                 panicstr = buf;
  511         va_end(ap);
  512         printf("panic: %s\n", buf);
  513 #ifdef SMP
  514         /* two separate prints in case of an unmapped page and trap */
  515         printf("cpuid = %d; ", PCPU_GET(cpuid));
  516 #ifdef APIC_IO
  517         printf("lapic.id = %08x\n", lapic.id);
  518 #else
  519         printf("\n");
  520 #endif
  521 #endif
  522 
  523 #if defined(DDB)
  524         if (newpanic && trace_on_panic)
  525                 backtrace();
  526         if (debugger_on_panic)
  527                 Debugger ("panic");
  528 #ifdef RESTARTABLE_PANICS
  529         /* See if the user aborted the panic, in which case we continue. */
  530         if (panicstr == NULL) {
  531 #ifdef SMP
  532                 atomic_store_rel_int(&panic_cpu, NOCPU);
  533 #endif
  534                 return;
  535         }
  536 #endif
  537 #endif
  538         mtx_lock_spin(&sched_lock);
  539         td->td_flags |= TDF_INPANIC;
  540         mtx_unlock_spin(&sched_lock);
  541         if (!sync_on_panic)
  542                 bootopt |= RB_NOSYNC;
  543         boot(bootopt);
  544 }
  545 
  546 /*
  547  * Support for poweroff delay.
  548  */
  549 #ifndef POWEROFF_DELAY
  550 # define POWEROFF_DELAY 5000
  551 #endif
  552 static int poweroff_delay = POWEROFF_DELAY;
  553 
  554 SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
  555         &poweroff_delay, 0, "");
  556 
  557 static void
  558 poweroff_wait(void *junk, int howto)
  559 {
  560 
  561         if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
  562                 return;
  563         DELAY(poweroff_delay * 1000);
  564 }
  565 
  566 /*
  567  * Some system processes (e.g. syncer) need to be stopped at appropriate
  568  * points in their main loops prior to a system shutdown, so that they
  569  * won't interfere with the shutdown process (e.g. by holding a disk buf
  570  * to cause sync to fail).  For each of these system processes, register
  571  * shutdown_kproc() as a handler for one of shutdown events.
  572  */
  573 static int kproc_shutdown_wait = 60;
  574 SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
  575     &kproc_shutdown_wait, 0, "");
  576 
  577 void
  578 kproc_shutdown(void *arg, int howto)
  579 {
  580         struct proc *p;
  581         int error;
  582 
  583         if (panicstr)
  584                 return;
  585 
  586         p = (struct proc *)arg;
  587         printf("Waiting (max %d seconds) for system process `%s' to stop...",
  588             kproc_shutdown_wait, p->p_comm);
  589         error = kthread_suspend(p, kproc_shutdown_wait * hz);
  590 
  591         if (error == EWOULDBLOCK)
  592                 printf("timed out\n");
  593         else
  594                 printf("stopped\n");
  595 }
  596 
  597 /* Registration of dumpers */
  598 int
  599 set_dumper(struct dumperinfo *di)
  600 {
  601 
  602         if (di == NULL) {
  603                 bzero(&dumper, sizeof dumper);
  604                 return (0);
  605         }
  606         if (dumper.dumper != NULL)
  607                 return (EBUSY);
  608         dumper = *di;
  609         return (0);
  610 }
  611 
  612 #if defined(__powerpc__)
  613 void
  614 dumpsys(struct dumperinfo *di __unused)
  615 {
  616 
  617         printf("Kernel dumps not implemented on this architecture\n");
  618 }
  619 #endif
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FreeBSD/Linux Kernel Cross Reference sys/kern/kern_shutdown.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_shutdown.c
