freebsd-dev/sys/kern/kern_shutdown.c
Marcel Moolenaar 27457a80e2 PowerPC, meet kernel core dumps. The support is based
on a generic dumper that creates an ELF core file and
uses PMAP functions to scan and iterate over memory
chunks, as well as handle memory mappings used during
dumping.
the PMAP layer can choose to return physical memory
chunks or virtual memory chunks. For minidumps, the
chunks should be virtual.

The default MMU I/F implementation for the scan_md()
method returns NULL. Thus, when a PMAP implementation
does not implement the required methods, an empty
core file is created. Here, empty means having an ELF
header only.

Obtained from:	Juniper Networks
2009-04-04 02:12:37 +00:00

702 lines
17 KiB
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("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_kdb.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/kerneldump.h>
#include <sys/kthread.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/smp.h> /* smp_active */
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/vimage.h>
#include <ddb/ddb.h>
#include <machine/cpu.h>
#include <machine/pcb.h>
#include <machine/smp.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/swap_pager.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");
/*
* 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 */
int rebooting; /* system is rebooting */
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.
*/
/* ARGSUSED */
int
reboot(struct thread *td, struct reboot_args *uap)
{
int error;
error = 0;
#ifdef MAC
error = mac_system_check_reboot(td->td_ucred, uap->opt);
#endif
if (error == 0)
error = priv_check(td, PRIV_REBOOT);
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. Device not defined or unavailable.\n");
return;
}
savectx(&dumppcb);
dumptid = curthread->td_tid;
dumping++;
#ifdef DDB
if (textdump_pending)
textdump_dumpsys(&dumper);
else
#endif
dumpsys(&dumper);
dumping--;
}
static int
isbufbusy(struct buf *bp)
{
if (((bp->b_flags & (B_INVAL | B_PERSISTENT)) == 0 &&
BUF_ISLOCKED(bp)) ||
((bp->b_flags & (B_DELWRI | B_INVAL)) == B_DELWRI))
return (1);
return (0);
}
/*
* Shutdown the system cleanly to prepare for reboot, halt, or power off.
*/
static void
boot(int howto)
{
static int first_buf_printf = 1;
#if defined(SMP)
/*
* Bind us to CPU 0 so that all shutdown code runs there. Some
* systems don't shutdown properly (i.e., ACPI power off) if we
* run on another processor.
*/
thread_lock(curthread);
sched_bind(curthread, 0);
thread_unlock(curthread);
KASSERT(PCPU_GET(cpuid) == 0, ("boot: not running on cpu 0"));
#endif
/* We're in the process of rebooting. */
rebooting = 1;
/* collect extra flags that shutdown_nice might have set */
howto |= shutdown_howto;
/* We are out of the debugger now. */
kdb_active = 0;
/*
* 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(curthread, 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 (isbufbusy(bp))
nbusy++;
if (nbusy == 0) {
if (first_buf_printf)
printf("All buffers synced.");
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(curthread, 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++) {
thread_lock(curthread);
mi_switch(SW_VOL, NULL);
thread_unlock(curthread);
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 (isbufbusy(bp)) {
#if 0
/* XXX: This is bogus. We should probably have a BO_REMOTE flag instead */
if (bp->b_dev == NULL) {
TAILQ_REMOVE(&mountlist,
bp->b_vp->v_mount, mnt_list);
continue;
}
#endif
nbusy++;
#if defined(SHOW_BUSYBUFS) || defined(DIAGNOSTIC)
printf(
"%d: bufobj:%p, flags:%0x, blkno:%ld, lblkno:%ld\n",
nbusy, bp->b_bufobj,
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();
}
swapoff_all();
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);
/* XXX This doesn't disable interrupts any more. Reconsider? */
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.
*/
void
panic(const char *fmt, ...)
{
struct thread *td = curthread;
int bootopt, newpanic;
va_list ap;
static char buf[256];
critical_enter();
#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(KDB_WHY_PANIC, "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
/*thread_lock(td); */
td->td_flags |= TDF_INPANIC;
/* thread_unlock(td); */
if (!sync_on_panic)
bootopt |= RB_NOSYNC;
critical_exit();
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 = kproc_suspend(p, kproc_shutdown_wait * hz);
if (error == EWOULDBLOCK)
printf("timed out\n");
else
printf("done\n");
}
void
kthread_shutdown(void *arg, int howto)
{
struct thread *td;
char procname[MAXCOMLEN + 1];
int error;
if (panicstr)
return;
td = (struct thread *)arg;
strlcpy(procname, td->td_name, sizeof(procname));
printf("Waiting (max %d seconds) for system thread `%s' to stop...",
kproc_shutdown_wait, procname);
error = kthread_suspend(td, 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);
}
/* Call dumper with bounds checking. */
int
dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
off_t offset, size_t length)
{
if (length != 0 && (offset < di->mediaoffset ||
offset - di->mediaoffset + length > di->mediasize)) {
printf("Attempt to write outside dump device boundaries.\n");
return (ENXIO);
}
return (di->dumper(di->priv, virtual, physical, offset, length));
}
void
mkdumpheader(struct kerneldumpheader *kdh, char *magic, uint32_t archver,
uint64_t dumplen, uint32_t blksz)
{
bzero(kdh, sizeof(*kdh));
strncpy(kdh->magic, magic, sizeof(kdh->magic));
strncpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
kdh->version = htod32(KERNELDUMPVERSION);
kdh->architectureversion = htod32(archver);
kdh->dumplength = htod64(dumplen);
kdh->dumptime = htod64(time_second);
kdh->blocksize = htod32(blksz);
strncpy(kdh->hostname, G_hostname, sizeof(kdh->hostname));
strncpy(kdh->versionstring, version, sizeof(kdh->versionstring));
if (panicstr != NULL)
strncpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
kdh->parity = kerneldump_parity(kdh);
}