--- /dev/null
+/*-
+ * 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;
+#ifdef XEN
+ HYPERVISOR_crash();
+#else
+ boot(bootopt);
+#endif
+}
+
+/*
+ * 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
projects / xen.git / commitdiff