FreeBSD-5.3/sys/kern/kern_shutdown.c
/*-
* Copyright (c) 1986, 1988, 1991, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kern_shutdown.c 8.3 (Berkeley) 1/21/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/kern_shutdown.c,v 1.163.2.2 2004/09/10 00:04:17 scottl Exp $");
#include "opt_kdb.h"
#include "opt_hw_wdog.h"
#include "opt_mac.h"
#include "opt_panic.h"
#include "opt_show_busybufs.h"
#include "opt_sched.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/eventhandler.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/resourcevar.h>
#include <sys/smp.h> /* smp_active */
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/vnode.h>
#include <machine/cpu.h>
#include <machine/pcb.h>
#include <machine/smp.h>
#include <sys/signalvar.h>
#ifndef PANIC_REBOOT_WAIT_TIME
#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
#endif
/*
* Note that stdarg.h and the ANSI style va_start macro is used for both
* ANSI and traditional C compilers.
*/
#include <machine/stdarg.h>
#ifdef KDB
#ifdef KDB_UNATTENDED
int debugger_on_panic = 0;
#else
int debugger_on_panic = 1;
#endif
SYSCTL_INT(_debug, OID_AUTO, debugger_on_panic, CTLFLAG_RW,
&debugger_on_panic, 0, "Run debugger on kernel panic");
#ifdef KDB_TRACE
int trace_on_panic = 1;
#else
int trace_on_panic = 0;
#endif
SYSCTL_INT(_debug, OID_AUTO, trace_on_panic, CTLFLAG_RW,
&trace_on_panic, 0, "Print stack trace on kernel panic");
#endif /* KDB */
int sync_on_panic = 0;
SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RW,
&sync_on_panic, 0, "Do a sync before rebooting from a panic");
SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0, "Shutdown environment");
#ifdef HW_WDOG
/*
* If there is a hardware watchdog, point this at the function needed to
* hold it off.
* It's needed when the kernel needs to do some lengthy operations.
* e.g. in wd.c when dumping core.. It's most annoying to have
* your precious core-dump only half written because the wdog kicked in.
*/
watchdog_tickle_fn wdog_tickler = NULL;
#endif /* HW_WDOG */
/*
* Variable panicstr contains argument to first call to panic; used as flag
* to indicate that the kernel has already called panic.
*/
const char *panicstr;
int dumping; /* system is dumping */
static struct dumperinfo dumper; /* our selected dumper */
/* Context information for dump-debuggers. */
static struct pcb dumppcb; /* Registers. */
static lwpid_t dumptid; /* Thread ID. */
static void boot(int) __dead2;
static void poweroff_wait(void *, int);
static void shutdown_halt(void *junk, int howto);
static void shutdown_panic(void *junk, int howto);
static void shutdown_reset(void *junk, int howto);
/* register various local shutdown events */
static void
shutdown_conf(void *unused)
{
EVENTHANDLER_REGISTER(shutdown_final, poweroff_wait, NULL,
SHUTDOWN_PRI_FIRST);
EVENTHANDLER_REGISTER(shutdown_final, shutdown_halt, NULL,
SHUTDOWN_PRI_LAST + 100);
EVENTHANDLER_REGISTER(shutdown_final, shutdown_panic, NULL,
SHUTDOWN_PRI_LAST + 100);
EVENTHANDLER_REGISTER(shutdown_final, shutdown_reset, NULL,
SHUTDOWN_PRI_LAST + 200);
}
SYSINIT(shutdown_conf, SI_SUB_INTRINSIC, SI_ORDER_ANY, shutdown_conf, NULL)
/*
* The system call that results in a reboot
*
* MPSAFE
*/
/* ARGSUSED */
int
reboot(struct thread *td, struct reboot_args *uap)
{
int error;
error = 0;
#ifdef MAC
error = mac_check_system_reboot(td->td_ucred, uap->opt);
#endif
if (error == 0)
error = suser(td);
if (error == 0) {
mtx_lock(&Giant);
boot(uap->opt);
mtx_unlock(&Giant);
}
return (error);
}
/*
* Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
*/
static int shutdown_howto = 0;
void
shutdown_nice(int howto)
{
shutdown_howto = howto;
/* Send a signal to init(8) and have it shutdown the world */
if (initproc != NULL) {
PROC_LOCK(initproc);
psignal(initproc, SIGINT);
PROC_UNLOCK(initproc);
} else {
/* No init(8) running, so simply reboot */
boot(RB_NOSYNC);
}
return;
}
static int waittime = -1;
static void
print_uptime(void)
{
int f;
struct timespec ts;
getnanouptime(&ts);
printf("Uptime: ");
f = 0;
if (ts.tv_sec >= 86400) {
printf("%ldd", (long)ts.tv_sec / 86400);
ts.tv_sec %= 86400;
f = 1;
}
if (f || ts.tv_sec >= 3600) {
printf("%ldh", (long)ts.tv_sec / 3600);
ts.tv_sec %= 3600;
f = 1;
}
if (f || ts.tv_sec >= 60) {
printf("%ldm", (long)ts.tv_sec / 60);
ts.tv_sec %= 60;
f = 1;
}
printf("%lds\n", (long)ts.tv_sec);
}
static void
doadump(void)
{
/*
* Sometimes people have to call this from the kernel debugger.
* (if 'panic' can not dump)
* Give them a clue as to why they can't dump.
*/
if (dumper.dumper == NULL) {
printf("Cannot dump. No dump device defined.\n");
return;
}
savectx(&dumppcb);
dumptid = curthread->td_tid;
dumping++;
dumpsys(&dumper);
}
/*
* Go through the rigmarole of shutting down..
* this used to be in machdep.c but I'll be dammned if I could see
* anything machine dependant in it.
*/
static void
boot(int howto)
{
static int first_buf_printf = 1;
/* collect extra flags that shutdown_nice might have set */
howto |= shutdown_howto;
/* We are out of the debugger now. */
kdb_active = 0;
#ifdef SMP
if (smp_active)
printf("boot() called on cpu#%d\n", PCPU_GET(cpuid));
#endif
/*
* Do any callouts that should be done BEFORE syncing the filesystems.
*/
EVENTHANDLER_INVOKE(shutdown_pre_sync, howto);
/*
* Now sync filesystems
*/
if (!cold && (howto & RB_NOSYNC) == 0 && waittime < 0) {
register struct buf *bp;
int iter, nbusy, pbusy;
#ifndef PREEMPTION
int subiter;
#endif
waittime = 0;
sync(&thread0, NULL);
/*
* With soft updates, some buffers that are
* written will be remarked as dirty until other
* buffers are written.
*/
for (iter = pbusy = 0; iter < 20; iter++) {
nbusy = 0;
for (bp = &buf[nbuf]; --bp >= buf; ) {
if ((bp->b_flags & B_INVAL) == 0 &&
BUF_REFCNT(bp) > 0) {
nbusy++;
} else if ((bp->b_flags & (B_DELWRI | B_INVAL))
== B_DELWRI) {
/* bawrite(bp);*/
nbusy++;
}
}
if (nbusy == 0) {
if (first_buf_printf)
printf("No buffers busy after final sync");
break;
}
if (first_buf_printf) {
printf("Syncing disks, buffers remaining... ");
first_buf_printf = 0;
}
printf("%d ", nbusy);
if (nbusy < pbusy)
iter = 0;
pbusy = nbusy;
sync(&thread0, NULL);
#ifdef PREEMPTION
/*
* Drop Giant and spin for a while to allow
* interrupt threads to run.
*/
DROP_GIANT();
DELAY(50000 * iter);
PICKUP_GIANT();
#else
/*
* Drop Giant and context switch several times to
* allow interrupt threads to run.
*/
DROP_GIANT();
for (subiter = 0; subiter < 50 * iter; subiter++) {
mtx_lock_spin(&sched_lock);
mi_switch(SW_VOL, NULL);
mtx_unlock_spin(&sched_lock);
DELAY(1000);
}
PICKUP_GIANT();
#endif
}
printf("\n");
/*
* Count only busy local buffers to prevent forcing
* a fsck if we're just a client of a wedged NFS server
*/
nbusy = 0;
for (bp = &buf[nbuf]; --bp >= buf; ) {
if (((bp->b_flags&B_INVAL) == 0 && BUF_REFCNT(bp)) ||
((bp->b_flags & (B_DELWRI|B_INVAL)) == B_DELWRI)) {
if (bp->b_dev == NULL) {
TAILQ_REMOVE(&mountlist,
bp->b_vp->v_mount, mnt_list);
continue;
}
nbusy++;
#if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
printf(
"%d: dev:%s, flags:%0x, blkno:%ld, lblkno:%ld\n",
nbusy, devtoname(bp->b_dev),
bp->b_flags, (long)bp->b_blkno,
(long)bp->b_lblkno);
#endif
}
}
if (nbusy) {
/*
* Failed to sync all blocks. Indicate this and don't
* unmount filesystems (thus forcing an fsck on reboot).
*/
printf("Giving up on %d buffers\n", nbusy);
DELAY(5000000); /* 5 seconds */
} else {
if (!first_buf_printf)
printf("Final sync complete\n");
/*
* Unmount filesystems
*/
if (panicstr == 0)
vfs_unmountall();
}
DELAY(100000); /* wait for console output to finish */
}
print_uptime();
/*
* Ok, now do things that assume all filesystem activity has
* been completed.
*/
EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
splhigh();
if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
doadump();
/* Now that we're going to really halt the system... */
EVENTHANDLER_INVOKE(shutdown_final, howto);
for(;;) ; /* safety against shutdown_reset not working */
/* NOTREACHED */
}
/*
* If the shutdown was a clean halt, behave accordingly.
*/
static void
shutdown_halt(void *junk, int howto)
{
if (howto & RB_HALT) {
printf("\n");
printf("The operating system has halted.\n");
printf("Please press any key to reboot.\n\n");
switch (cngetc()) {
case -1: /* No console, just die */
cpu_halt();
/* NOTREACHED */
default:
howto &= ~RB_HALT;
break;
}
}
}
/*
* Check to see if the system paniced, pause and then reboot
* according to the specified delay.
*/
static void
shutdown_panic(void *junk, int howto)
{
int loop;
if (howto & RB_DUMP) {
if (PANIC_REBOOT_WAIT_TIME != 0) {
if (PANIC_REBOOT_WAIT_TIME != -1) {
printf("Automatic reboot in %d seconds - "
"press a key on the console to abort\n",
PANIC_REBOOT_WAIT_TIME);
for (loop = PANIC_REBOOT_WAIT_TIME * 10;
loop > 0; --loop) {
DELAY(1000 * 100); /* 1/10th second */
/* Did user type a key? */
if (cncheckc() != -1)
break;
}
if (!loop)
return;
}
} else { /* zero time specified - reboot NOW */
return;
}
printf("--> Press a key on the console to reboot,\n");
printf("--> or switch off the system now.\n");
cngetc();
}
}
/*
* Everything done, now reset
*/
static void
shutdown_reset(void *junk, int howto)
{
printf("Rebooting...\n");
DELAY(1000000); /* wait 1 sec for printf's to complete and be read */
/* cpu_boot(howto); */ /* doesn't do anything at the moment */
cpu_reset();
/* NOTREACHED */ /* assuming reset worked */
}
#ifdef SMP
static u_int panic_cpu = NOCPU;
#endif
/*
* Panic is called on unresolvable fatal errors. It prints "panic: mesg",
* and then reboots. If we are called twice, then we avoid trying to sync
* the disks as this often leads to recursive panics.
*
* MPSAFE
*/
void
panic(const char *fmt, ...)
{
struct thread *td = curthread;
int bootopt, newpanic;
va_list ap;
static char buf[256];
#ifdef SMP
/*
* We don't want multiple CPU's to panic at the same time, so we
* use panic_cpu as a simple spinlock. We have to keep checking
* panic_cpu if we are spinning in case the panic on the first
* CPU is canceled.
*/
if (panic_cpu != PCPU_GET(cpuid))
while (atomic_cmpset_int(&panic_cpu, NOCPU,
PCPU_GET(cpuid)) == 0)
while (panic_cpu != NOCPU)
; /* nothing */
#endif
bootopt = RB_AUTOBOOT | RB_DUMP;
newpanic = 0;
if (panicstr)
bootopt |= RB_NOSYNC;
else {
panicstr = fmt;
newpanic = 1;
}
va_start(ap, fmt);
if (newpanic) {
(void)vsnprintf(buf, sizeof(buf), fmt, ap);
panicstr = buf;
printf("panic: %s\n", buf);
} else {
printf("panic: ");
vprintf(fmt, ap);
printf("\n");
}
va_end(ap);
#ifdef SMP
printf("cpuid = %d\n", PCPU_GET(cpuid));
#endif
#ifdef KDB
if (newpanic && trace_on_panic)
kdb_backtrace();
if (debugger_on_panic)
kdb_enter("panic");
#ifdef RESTARTABLE_PANICS
/* See if the user aborted the panic, in which case we continue. */
if (panicstr == NULL) {
#ifdef SMP
atomic_store_rel_int(&panic_cpu, NOCPU);
#endif
return;
}
#endif
#endif
mtx_lock_spin(&sched_lock);
td->td_flags |= TDF_INPANIC;
mtx_unlock_spin(&sched_lock);
if (!sync_on_panic)
bootopt |= RB_NOSYNC;
boot(bootopt);
}
/*
* Support for poweroff delay.
*/
#ifndef POWEROFF_DELAY
# define POWEROFF_DELAY 5000
#endif
static int poweroff_delay = POWEROFF_DELAY;
SYSCTL_INT(_kern_shutdown, OID_AUTO, poweroff_delay, CTLFLAG_RW,
&poweroff_delay, 0, "");
static void
poweroff_wait(void *junk, int howto)
{
if (!(howto & RB_POWEROFF) || poweroff_delay <= 0)
return;
DELAY(poweroff_delay * 1000);
}
/*
* Some system processes (e.g. syncer) need to be stopped at appropriate
* points in their main loops prior to a system shutdown, so that they
* won't interfere with the shutdown process (e.g. by holding a disk buf
* to cause sync to fail). For each of these system processes, register
* shutdown_kproc() as a handler for one of shutdown events.
*/
static int kproc_shutdown_wait = 60;
SYSCTL_INT(_kern_shutdown, OID_AUTO, kproc_shutdown_wait, CTLFLAG_RW,
&kproc_shutdown_wait, 0, "");
void
kproc_shutdown(void *arg, int howto)
{
struct proc *p;
char procname[MAXCOMLEN + 1];
int error;
if (panicstr)
return;
p = (struct proc *)arg;
strlcpy(procname, p->p_comm, sizeof(procname));
printf("Waiting (max %d seconds) for system process `%s' to stop...",
kproc_shutdown_wait, procname);
error = kthread_suspend(p, kproc_shutdown_wait * hz);
if (error == EWOULDBLOCK)
printf("timed out\n");
else
printf("done\n");
}
/* Registration of dumpers */
int
set_dumper(struct dumperinfo *di)
{
if (di == NULL) {
bzero(&dumper, sizeof dumper);
return (0);
}
if (dumper.dumper != NULL)
return (EBUSY);
dumper = *di;
return (0);
}
#if defined(__powerpc__)
void
dumpsys(struct dumperinfo *di __unused)
{
printf("Kernel dumps not implemented on this architecture\n");
}
#endif