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freebsd-skq/sys/kern/kern_shutdown.c
Matt Macy 11d4f748d7 remove unused variable
2018-05-19 03:55:42 +00:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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.
* 3. 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_ekcd.h"
#include "opt_kdb.h"
#include "opt_panic.h"
#include "opt_sched.h"
#include "opt_watchdog.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/compressor.h>
#include <sys/cons.h>
#include <sys/eventhandler.h>
#include <sys/filedesc.h>
#include <sys/jail.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/kerneldump.h>
#include <sys/kthread.h>
#include <sys/ktr.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/sysproto.h>
#include <sys/taskqueue.h>
#include <sys/vnode.h>
#include <sys/watchdog.h>
#include <crypto/rijndael/rijndael-api-fst.h>
#include <crypto/sha2/sha256.h>
#include <ddb/ddb.h>
#include <machine/cpu.h>
#include <machine/dump.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>
static MALLOC_DEFINE(M_DUMPER, "dumper", "dumper block buffer");
#ifndef PANIC_REBOOT_WAIT_TIME
#define PANIC_REBOOT_WAIT_TIME 15 /* default to 15 seconds */
#endif
static int panic_reboot_wait_time = PANIC_REBOOT_WAIT_TIME;
SYSCTL_INT(_kern, OID_AUTO, panic_reboot_wait_time, CTLFLAG_RWTUN,
&panic_reboot_wait_time, 0,
"Seconds to wait before rebooting after a panic");
/*
* 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_RWTUN | CTLFLAG_SECURE,
&debugger_on_panic, 0, "Run debugger on kernel panic");
#ifdef KDB_TRACE
static int trace_on_panic = 1;
static bool trace_all_panics = true;
#else
static int trace_on_panic = 0;
static bool trace_all_panics = false;
#endif
SYSCTL_INT(_debug, OID_AUTO, trace_on_panic,
CTLFLAG_RWTUN | CTLFLAG_SECURE,
&trace_on_panic, 0, "Print stack trace on kernel panic");
SYSCTL_BOOL(_debug, OID_AUTO, trace_all_panics, CTLFLAG_RWTUN,
&trace_all_panics, 0, "Print stack traces on secondary kernel panics");
#endif /* KDB */
static int sync_on_panic = 0;
SYSCTL_INT(_kern, OID_AUTO, sync_on_panic, CTLFLAG_RWTUN,
&sync_on_panic, 0, "Do a sync before rebooting from a panic");
static bool poweroff_on_panic = 0;
SYSCTL_BOOL(_kern, OID_AUTO, poweroff_on_panic, CTLFLAG_RWTUN,
&poweroff_on_panic, 0, "Do a power off instead of a reboot on a panic");
static bool powercycle_on_panic = 0;
SYSCTL_BOOL(_kern, OID_AUTO, powercycle_on_panic, CTLFLAG_RWTUN,
&powercycle_on_panic, 0, "Do a power cycle instead of a reboot on a panic");
static SYSCTL_NODE(_kern, OID_AUTO, shutdown, CTLFLAG_RW, 0,
"Shutdown environment");
#ifndef DIAGNOSTIC
static int show_busybufs;
#else
static int show_busybufs = 1;
#endif
SYSCTL_INT(_kern_shutdown, OID_AUTO, show_busybufs, CTLFLAG_RW,
&show_busybufs, 0, "");
int suspend_blocked = 0;
SYSCTL_INT(_kern, OID_AUTO, suspend_blocked, CTLFLAG_RW,
&suspend_blocked, 0, "Block suspend due to a pending shutdown");
#ifdef EKCD
FEATURE(ekcd, "Encrypted kernel crash dumps support");
MALLOC_DEFINE(M_EKCD, "ekcd", "Encrypted kernel crash dumps data");
struct kerneldumpcrypto {
uint8_t kdc_encryption;
uint8_t kdc_iv[KERNELDUMP_IV_MAX_SIZE];
keyInstance kdc_ki;
cipherInstance kdc_ci;
uint32_t kdc_dumpkeysize;
struct kerneldumpkey kdc_dumpkey[];
};
#endif
struct kerneldumpcomp {
uint8_t kdc_format;
struct compressor *kdc_stream;
uint8_t *kdc_buf;
size_t kdc_resid;
};
static struct kerneldumpcomp *kerneldumpcomp_create(struct dumperinfo *di,
uint8_t compression);
static void kerneldumpcomp_destroy(struct dumperinfo *di);
static int kerneldumpcomp_write_cb(void *base, size_t len, off_t off, void *arg);
static int kerneldump_gzlevel = 6;
SYSCTL_INT(_kern, OID_AUTO, kerneldump_gzlevel, CTLFLAG_RWTUN,
&kerneldump_gzlevel, 0,
"Kernel crash dump compression level");
/*
* 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. */
lwpid_t dumptid; /* Thread ID. */
static struct cdevsw reroot_cdevsw = {
.d_version = D_VERSION,
.d_name = "reroot",
};
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);
static int kern_reroot(void);
/* 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 only reason this exists is to create the /dev/reroot/ directory,
* used by reroot code in init(8) as a mountpoint for tmpfs.
*/
static void
reroot_conf(void *unused)
{
int error;
struct cdev *cdev;
error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &cdev,
&reroot_cdevsw, NULL, UID_ROOT, GID_WHEEL, 0600, "reroot/reroot");
if (error != 0) {
printf("%s: failed to create device node, error %d",
__func__, error);
}
}
SYSINIT(reroot_conf, SI_SUB_DEVFS, SI_ORDER_ANY, reroot_conf, NULL);
/*
* The system call that results in a reboot.
*/
/* ARGSUSED */
int
sys_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) {
if (uap->opt & RB_REROOT)
error = kern_reroot();
else
kern_reboot(uap->opt);
}
return (error);
}
static void
shutdown_nice_task_fn(void *arg, int pending __unused)
{
int howto;
howto = (uintptr_t)arg;
/* Send a signal to init(8) and have it shutdown the world. */
PROC_LOCK(initproc);
if (howto & RB_POWEROFF)
kern_psignal(initproc, SIGUSR2);
else if (howto & RB_POWERCYCLE)
kern_psignal(initproc, SIGWINCH);
else if (howto & RB_HALT)
kern_psignal(initproc, SIGUSR1);
else
kern_psignal(initproc, SIGINT);
PROC_UNLOCK(initproc);
}
static struct task shutdown_nice_task = TASK_INITIALIZER(0,
&shutdown_nice_task_fn, NULL);
/*
* Called by events that want to shut down.. e.g <CTL><ALT><DEL> on a PC
*/
void
shutdown_nice(int howto)
{
if (initproc != NULL && !SCHEDULER_STOPPED()) {
shutdown_nice_task.ta_context = (void *)(uintptr_t)howto;
taskqueue_enqueue(taskqueue_fast, &shutdown_nice_task);
} else {
/*
* No init(8) running, or scheduler would not allow it
* to run, so simply reboot.
*/
kern_reboot(howto | RB_NOSYNC);
}
}
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);
}
int
doadump(boolean_t textdump)
{
boolean_t coredump;
int error;
error = 0;
if (dumping)
return (EBUSY);
if (dumper.dumper == NULL)
return (ENXIO);
savectx(&dumppcb);
dumptid = curthread->td_tid;
dumping++;
coredump = TRUE;
#ifdef DDB
if (textdump && textdump_pending) {
coredump = FALSE;
textdump_dumpsys(&dumper);
}
#endif
if (coredump)
error = dumpsys(&dumper);
dumping--;
return (error);
}
/*
* Shutdown the system cleanly to prepare for reboot, halt, or power off.
*/
void
kern_reboot(int howto)
{
static int once = 0;
/*
* Normal paths here don't hold Giant, but we can wind up here
* unexpectedly with it held. Drop it now so we don't have to
* drop and pick it up elsewhere. The paths it is locking will
* never be returned to, and it is preferable to preclude
* deadlock than to lock against code that won't ever
* continue.
*/
while (mtx_owned(&Giant))
mtx_unlock(&Giant);
#if defined(SMP)
/*
* Bind us to the first CPU so that all shutdown code runs there. Some
* systems don't shutdown properly (i.e., ACPI power off) if we
* run on another processor.
*/
if (!SCHEDULER_STOPPED()) {
thread_lock(curthread);
sched_bind(curthread, CPU_FIRST());
thread_unlock(curthread);
KASSERT(PCPU_GET(cpuid) == CPU_FIRST(),
("boot: not running on cpu 0"));
}
#endif
/* We're in the process of rebooting. */
rebooting = 1;
/* 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 && once == 0) {
once = 1;
bufshutdown(show_busybufs);
}
print_uptime();
cngrab();
/*
* Ok, now do things that assume all filesystem activity has
* been completed.
*/
EVENTHANDLER_INVOKE(shutdown_post_sync, howto);
if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping)
doadump(TRUE);
/* Now that we're going to really halt the system... */
EVENTHANDLER_INVOKE(shutdown_final, howto);
for(;;) ; /* safety against shutdown_reset not working */
/* NOTREACHED */
}
/*
* The system call that results in changing the rootfs.
*/
static int
kern_reroot(void)
{
struct vnode *oldrootvnode, *vp;
struct mount *mp, *devmp;
int error;
if (curproc != initproc)
return (EPERM);
/*
* Mark the filesystem containing currently-running executable
* (the temporary copy of init(8)) busy.
*/
vp = curproc->p_textvp;
error = vn_lock(vp, LK_SHARED);
if (error != 0)
return (error);
mp = vp->v_mount;
error = vfs_busy(mp, MBF_NOWAIT);
if (error != 0) {
vfs_ref(mp);
VOP_UNLOCK(vp, 0);
error = vfs_busy(mp, 0);
vn_lock(vp, LK_SHARED | LK_RETRY);
vfs_rel(mp);
if (error != 0) {
VOP_UNLOCK(vp, 0);
return (ENOENT);
}
if (vp->v_iflag & VI_DOOMED) {
VOP_UNLOCK(vp, 0);
vfs_unbusy(mp);
return (ENOENT);
}
}
VOP_UNLOCK(vp, 0);
/*
* Remove the filesystem containing currently-running executable
* from the mount list, to prevent it from being unmounted
* by vfs_unmountall(), and to avoid confusing vfs_mountroot().
*
* Also preserve /dev - forcibly unmounting it could cause driver
* reinitialization.
*/
vfs_ref(rootdevmp);
devmp = rootdevmp;
rootdevmp = NULL;
mtx_lock(&mountlist_mtx);
TAILQ_REMOVE(&mountlist, mp, mnt_list);
TAILQ_REMOVE(&mountlist, devmp, mnt_list);
mtx_unlock(&mountlist_mtx);
oldrootvnode = rootvnode;
/*
* Unmount everything except for the two filesystems preserved above.
*/
vfs_unmountall();
/*
* Add /dev back; vfs_mountroot() will move it into its new place.
*/
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_HEAD(&mountlist, devmp, mnt_list);
mtx_unlock(&mountlist_mtx);
rootdevmp = devmp;
vfs_rel(rootdevmp);
/*
* Mount the new rootfs.
*/
vfs_mountroot();
/*
* Update all references to the old rootvnode.
*/
mountcheckdirs(oldrootvnode, rootvnode);
/*
* Add the temporary filesystem back and unbusy it.
*/
mtx_lock(&mountlist_mtx);
TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
mtx_unlock(&mountlist_mtx);
vfs_unbusy(mp);
return (0);
}
/*
* 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:
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 */
/*
* Acquiring smp_ipi_mtx here has a double effect:
* - it disables interrupts avoiding CPU0 preemption
* by fast handlers (thus deadlocking against other CPUs)
* - it avoids deadlocks against smp_rendezvous() or, more
* generally, threads busy-waiting, with this spinlock held,
* and waiting for responses by threads on other CPUs
* (ie. smp_tlb_shootdown()).
*
* For the !SMP case it just needs to handle the former problem.
*/
#ifdef SMP
mtx_lock_spin(&smp_ipi_mtx);
#else
spinlock_enter();
#endif
/* cpu_boot(howto); */ /* doesn't do anything at the moment */
cpu_reset();
/* NOTREACHED */ /* assuming reset worked */
}
#if defined(WITNESS) || defined(INVARIANT_SUPPORT)
static int kassert_warn_only = 0;
#ifdef KDB
static int kassert_do_kdb = 0;
#endif
#ifdef KTR
static int kassert_do_ktr = 0;
#endif
static int kassert_do_log = 1;
static int kassert_log_pps_limit = 4;
static int kassert_log_mute_at = 0;
static int kassert_log_panic_at = 0;
static int kassert_suppress_in_panic = 0;
static int kassert_warnings = 0;
SYSCTL_NODE(_debug, OID_AUTO, kassert, CTLFLAG_RW, NULL, "kassert options");
SYSCTL_INT(_debug_kassert, OID_AUTO, warn_only, CTLFLAG_RWTUN,
&kassert_warn_only, 0,
"KASSERT triggers a panic (1) or just a warning (0)");
#ifdef KDB
SYSCTL_INT(_debug_kassert, OID_AUTO, do_kdb, CTLFLAG_RWTUN,
&kassert_do_kdb, 0, "KASSERT will enter the debugger");
#endif
#ifdef KTR
SYSCTL_UINT(_debug_kassert, OID_AUTO, do_ktr, CTLFLAG_RWTUN,
&kassert_do_ktr, 0,
"KASSERT does a KTR, set this to the KTRMASK you want");
#endif
SYSCTL_INT(_debug_kassert, OID_AUTO, do_log, CTLFLAG_RWTUN,
&kassert_do_log, 0,
"If warn_only is enabled, log (1) or do not log (0) assertion violations");
SYSCTL_INT(_debug_kassert, OID_AUTO, warnings, CTLFLAG_RWTUN,
&kassert_warnings, 0, "number of KASSERTs that have been triggered");
SYSCTL_INT(_debug_kassert, OID_AUTO, log_panic_at, CTLFLAG_RWTUN,
&kassert_log_panic_at, 0, "max number of KASSERTS before we will panic");
SYSCTL_INT(_debug_kassert, OID_AUTO, log_pps_limit, CTLFLAG_RWTUN,
&kassert_log_pps_limit, 0, "limit number of log messages per second");
SYSCTL_INT(_debug_kassert, OID_AUTO, log_mute_at, CTLFLAG_RWTUN,
&kassert_log_mute_at, 0, "max number of KASSERTS to log");
SYSCTL_INT(_debug_kassert, OID_AUTO, suppress_in_panic, CTLFLAG_RWTUN,
&kassert_suppress_in_panic, 0,
"KASSERTs will be suppressed while handling a panic");
static int kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS);
SYSCTL_PROC(_debug_kassert, OID_AUTO, kassert,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, NULL, 0,
kassert_sysctl_kassert, "I", "set to trigger a test kassert");
static int
kassert_sysctl_kassert(SYSCTL_HANDLER_ARGS)
{
int error, i;
error = sysctl_wire_old_buffer(req, sizeof(int));
if (error == 0) {
i = 0;
error = sysctl_handle_int(oidp, &i, 0, req);
}
if (error != 0 || req->newptr == NULL)
return (error);
KASSERT(0, ("kassert_sysctl_kassert triggered kassert %d", i));
return (0);
}
/*
* Called by KASSERT, this decides if we will panic
* or if we will log via printf and/or ktr.
*/
void
kassert_panic(const char *fmt, ...)
{
static char buf[256];
va_list ap;
va_start(ap, fmt);
(void)vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
/*
* If we are suppressing secondary panics, log the warning but do not
* re-enter panic/kdb.
*/
if (panicstr != NULL && kassert_suppress_in_panic) {
if (kassert_do_log) {
printf("KASSERT failed: %s\n", buf);
#ifdef KDB
if (trace_all_panics && trace_on_panic)
kdb_backtrace();
#endif
}
return;
}
/*
* panic if we're not just warning, or if we've exceeded
* kassert_log_panic_at warnings.
*/
if (!kassert_warn_only ||
(kassert_log_panic_at > 0 &&
kassert_warnings >= kassert_log_panic_at)) {
va_start(ap, fmt);
vpanic(fmt, ap);
/* NORETURN */
}
#ifdef KTR
if (kassert_do_ktr)
CTR0(ktr_mask, buf);
#endif /* KTR */
/*
* log if we've not yet met the mute limit.
*/
if (kassert_do_log &&
(kassert_log_mute_at == 0 ||
kassert_warnings < kassert_log_mute_at)) {
static struct timeval lasterr;
static int curerr;
if (ppsratecheck(&lasterr, &curerr, kassert_log_pps_limit)) {
printf("KASSERT failed: %s\n", buf);
kdb_backtrace();
}
}
#ifdef KDB
if (kassert_do_kdb) {
kdb_enter(KDB_WHY_KASSERT, buf);
}
#endif
atomic_add_int(&kassert_warnings, 1);
}
#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, ...)
{
va_list ap;
va_start(ap, fmt);
vpanic(fmt, ap);
}
void
vpanic(const char *fmt, va_list ap)
{
#ifdef SMP
cpuset_t other_cpus;
#endif
struct thread *td = curthread;
int bootopt, newpanic;
static char buf[256];
spinlock_enter();
#ifdef SMP
/*
* stop_cpus_hard(other_cpus) should prevent multiple CPUs from
* concurrently entering panic. Only the winner will proceed
* further.
*/
if (panicstr == NULL && !kdb_active) {
other_cpus = all_cpus;
CPU_CLR(PCPU_GET(cpuid), &other_cpus);
stop_cpus_hard(other_cpus);
}
#endif
/*
* Ensure that the scheduler is stopped while panicking, even if panic
* has been entered from kdb.
*/
td->td_stopsched = 1;
bootopt = RB_AUTOBOOT;
newpanic = 0;
if (panicstr)
bootopt |= RB_NOSYNC;
else {
bootopt |= RB_DUMP;
panicstr = fmt;
newpanic = 1;
}
if (newpanic) {
(void)vsnprintf(buf, sizeof(buf), fmt, ap);
panicstr = buf;
cngrab();
printf("panic: %s\n", buf);
} else {
printf("panic: ");
vprintf(fmt, ap);
printf("\n");
}
#ifdef SMP
printf("cpuid = %d\n", PCPU_GET(cpuid));
#endif
printf("time = %jd\n", (intmax_t )time_second);
#ifdef KDB
if ((newpanic || trace_all_panics) && trace_on_panic)
kdb_backtrace();
if (debugger_on_panic)
kdb_enter(KDB_WHY_PANIC, "panic");
#endif
/*thread_lock(td); */
td->td_flags |= TDF_INPANIC;
/* thread_unlock(td); */
if (!sync_on_panic)
bootopt |= RB_NOSYNC;
if (poweroff_on_panic)
bootopt |= RB_POWEROFF;
if (powercycle_on_panic)
bootopt |= RB_POWERCYCLE;
kern_reboot(bootopt);
}
/*
* Support for poweroff delay.
*
* Please note that setting this delay too short might power off your machine
* before the write cache on your hard disk has been flushed, leading to
* soft-updates inconsistencies.
*/
#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, "Delay before poweroff to write disk caches (msec)");
static void
poweroff_wait(void *junk, int howto)
{
if ((howto & (RB_POWEROFF | RB_POWERCYCLE)) == 0 || 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, "Max wait time (sec) to stop for each process");
void
kproc_shutdown(void *arg, int howto)
{
struct proc *p;
int error;
if (panicstr)
return;
p = (struct proc *)arg;
printf("Waiting (max %d seconds) for system process `%s' to stop... ",
kproc_shutdown_wait, p->p_comm);
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;
int error;
if (panicstr)
return;
td = (struct thread *)arg;
printf("Waiting (max %d seconds) for system thread `%s' to stop... ",
kproc_shutdown_wait, td->td_name);
error = kthread_suspend(td, kproc_shutdown_wait * hz);
if (error == EWOULDBLOCK)
printf("timed out\n");
else
printf("done\n");
}
static char dumpdevname[sizeof(((struct cdev*)NULL)->si_name)];
SYSCTL_STRING(_kern_shutdown, OID_AUTO, dumpdevname, CTLFLAG_RD,
dumpdevname, 0, "Device for kernel dumps");
static int _dump_append(struct dumperinfo *di, void *virtual,
vm_offset_t physical, size_t length);
#ifdef EKCD
static struct kerneldumpcrypto *
kerneldumpcrypto_create(size_t blocksize, uint8_t encryption,
const uint8_t *key, uint32_t encryptedkeysize, const uint8_t *encryptedkey)
{
struct kerneldumpcrypto *kdc;
struct kerneldumpkey *kdk;
uint32_t dumpkeysize;
dumpkeysize = roundup2(sizeof(*kdk) + encryptedkeysize, blocksize);
kdc = malloc(sizeof(*kdc) + dumpkeysize, M_EKCD, M_WAITOK | M_ZERO);
arc4rand(kdc->kdc_iv, sizeof(kdc->kdc_iv), 0);
kdc->kdc_encryption = encryption;
switch (kdc->kdc_encryption) {
case KERNELDUMP_ENC_AES_256_CBC:
if (rijndael_makeKey(&kdc->kdc_ki, DIR_ENCRYPT, 256, key) <= 0)
goto failed;
break;
default:
goto failed;
}
kdc->kdc_dumpkeysize = dumpkeysize;
kdk = kdc->kdc_dumpkey;
kdk->kdk_encryption = kdc->kdc_encryption;
memcpy(kdk->kdk_iv, kdc->kdc_iv, sizeof(kdk->kdk_iv));
kdk->kdk_encryptedkeysize = htod32(encryptedkeysize);
memcpy(kdk->kdk_encryptedkey, encryptedkey, encryptedkeysize);
return (kdc);
failed:
explicit_bzero(kdc, sizeof(*kdc) + dumpkeysize);
free(kdc, M_EKCD);
return (NULL);
}
static int
kerneldumpcrypto_init(struct kerneldumpcrypto *kdc)
{
uint8_t hash[SHA256_DIGEST_LENGTH];
SHA256_CTX ctx;
struct kerneldumpkey *kdk;
int error;
error = 0;
if (kdc == NULL)
return (0);
/*
* When a user enters ddb it can write a crash dump multiple times.
* Each time it should be encrypted using a different IV.
*/
SHA256_Init(&ctx);
SHA256_Update(&ctx, kdc->kdc_iv, sizeof(kdc->kdc_iv));
SHA256_Final(hash, &ctx);
bcopy(hash, kdc->kdc_iv, sizeof(kdc->kdc_iv));
switch (kdc->kdc_encryption) {
case KERNELDUMP_ENC_AES_256_CBC:
if (rijndael_cipherInit(&kdc->kdc_ci, MODE_CBC,
kdc->kdc_iv) <= 0) {
error = EINVAL;
goto out;
}
break;
default:
error = EINVAL;
goto out;
}
kdk = kdc->kdc_dumpkey;
memcpy(kdk->kdk_iv, kdc->kdc_iv, sizeof(kdk->kdk_iv));
out:
explicit_bzero(hash, sizeof(hash));
return (error);
}
static uint32_t
kerneldumpcrypto_dumpkeysize(const struct kerneldumpcrypto *kdc)
{
if (kdc == NULL)
return (0);
return (kdc->kdc_dumpkeysize);
}
#endif /* EKCD */
static struct kerneldumpcomp *
kerneldumpcomp_create(struct dumperinfo *di, uint8_t compression)
{
struct kerneldumpcomp *kdcomp;
int format;
switch (compression) {
case KERNELDUMP_COMP_GZIP:
format = COMPRESS_GZIP;
break;
case KERNELDUMP_COMP_ZSTD:
format = COMPRESS_ZSTD;
break;
default:
return (NULL);
}
kdcomp = malloc(sizeof(*kdcomp), M_DUMPER, M_WAITOK | M_ZERO);
kdcomp->kdc_format = compression;
kdcomp->kdc_stream = compressor_init(kerneldumpcomp_write_cb,
format, di->maxiosize, kerneldump_gzlevel, di);
if (kdcomp->kdc_stream == NULL) {
free(kdcomp, M_DUMPER);
return (NULL);
}
kdcomp->kdc_buf = malloc(di->maxiosize, M_DUMPER, M_WAITOK | M_NODUMP);
return (kdcomp);
}
static void
kerneldumpcomp_destroy(struct dumperinfo *di)
{
struct kerneldumpcomp *kdcomp;
kdcomp = di->kdcomp;
if (kdcomp == NULL)
return;
compressor_fini(kdcomp->kdc_stream);
explicit_bzero(kdcomp->kdc_buf, di->maxiosize);
free(kdcomp->kdc_buf, M_DUMPER);
free(kdcomp, M_DUMPER);
}
/* Registration of dumpers */
int
set_dumper(struct dumperinfo *di, const char *devname, struct thread *td,
uint8_t compression, uint8_t encryption, const uint8_t *key,
uint32_t encryptedkeysize, const uint8_t *encryptedkey)
{
size_t wantcopy;
int error;
error = priv_check(td, PRIV_SETDUMPER);
if (error != 0)
return (error);
if (dumper.dumper != NULL)
return (EBUSY);
dumper = *di;
dumper.blockbuf = NULL;
dumper.kdcrypto = NULL;
dumper.kdcomp = NULL;
if (encryption != KERNELDUMP_ENC_NONE) {
#ifdef EKCD
dumper.kdcrypto = kerneldumpcrypto_create(di->blocksize,
encryption, key, encryptedkeysize, encryptedkey);
if (dumper.kdcrypto == NULL) {
error = EINVAL;
goto cleanup;
}
#else
error = EOPNOTSUPP;
goto cleanup;
#endif
}
wantcopy = strlcpy(dumpdevname, devname, sizeof(dumpdevname));
if (wantcopy >= sizeof(dumpdevname)) {
printf("set_dumper: device name truncated from '%s' -> '%s'\n",
devname, dumpdevname);
}
if (compression != KERNELDUMP_COMP_NONE) {
/*
* We currently can't support simultaneous encryption and
* compression.
*/
if (encryption != KERNELDUMP_ENC_NONE) {
error = EOPNOTSUPP;
goto cleanup;
}
dumper.kdcomp = kerneldumpcomp_create(&dumper, compression);
if (dumper.kdcomp == NULL) {
error = EINVAL;
goto cleanup;
}
}
dumper.blockbuf = malloc(di->blocksize, M_DUMPER, M_WAITOK | M_ZERO);
return (0);
cleanup:
(void)clear_dumper(td);
return (error);
}
int
clear_dumper(struct thread *td)
{
int error;
error = priv_check(td, PRIV_SETDUMPER);
if (error != 0)
return (error);
#ifdef NETDUMP
netdump_mbuf_drain();
#endif
#ifdef EKCD
if (dumper.kdcrypto != NULL) {
explicit_bzero(dumper.kdcrypto, sizeof(*dumper.kdcrypto) +
dumper.kdcrypto->kdc_dumpkeysize);
free(dumper.kdcrypto, M_EKCD);
}
#endif
kerneldumpcomp_destroy(&dumper);
if (dumper.blockbuf != NULL) {
explicit_bzero(dumper.blockbuf, dumper.blocksize);
free(dumper.blockbuf, M_DUMPER);
}
explicit_bzero(&dumper, sizeof(dumper));
dumpdevname[0] = '\0';
return (0);
}
static int
dump_check_bounds(struct dumperinfo *di, off_t offset, size_t length)
{
if (di->mediasize > 0 && length != 0 && (offset < di->mediaoffset ||
offset - di->mediaoffset + length > di->mediasize)) {
if (di->kdcomp != NULL && offset >= di->mediaoffset) {
printf(
"Compressed dump failed to fit in device boundaries.\n");
return (E2BIG);
}
printf("Attempt to write outside dump device boundaries.\n"
"offset(%jd), mediaoffset(%jd), length(%ju), mediasize(%jd).\n",
(intmax_t)offset, (intmax_t)di->mediaoffset,
(uintmax_t)length, (intmax_t)di->mediasize);
return (ENOSPC);
}
if (length % di->blocksize != 0) {
printf("Attempt to write partial block of length %ju.\n",
(uintmax_t)length);
return (EINVAL);
}
if (offset % di->blocksize != 0) {
printf("Attempt to write at unaligned offset %jd.\n",
(intmax_t)offset);
return (EINVAL);
}
return (0);
}
#ifdef EKCD
static int
dump_encrypt(struct kerneldumpcrypto *kdc, uint8_t *buf, size_t size)
{
switch (kdc->kdc_encryption) {
case KERNELDUMP_ENC_AES_256_CBC:
if (rijndael_blockEncrypt(&kdc->kdc_ci, &kdc->kdc_ki, buf,
8 * size, buf) <= 0) {
return (EIO);
}
if (rijndael_cipherInit(&kdc->kdc_ci, MODE_CBC,
buf + size - 16 /* IV size for AES-256-CBC */) <= 0) {
return (EIO);
}
break;
default:
return (EINVAL);
}
return (0);
}
/* Encrypt data and call dumper. */
static int
dump_encrypted_write(struct dumperinfo *di, void *virtual,
vm_offset_t physical, off_t offset, size_t length)
{
static uint8_t buf[KERNELDUMP_BUFFER_SIZE];
struct kerneldumpcrypto *kdc;
int error;
size_t nbytes;
kdc = di->kdcrypto;
while (length > 0) {
nbytes = MIN(length, sizeof(buf));
bcopy(virtual, buf, nbytes);
if (dump_encrypt(kdc, buf, nbytes) != 0)
return (EIO);
error = dump_write(di, buf, physical, offset, nbytes);
if (error != 0)
return (error);
offset += nbytes;
virtual = (void *)((uint8_t *)virtual + nbytes);
length -= nbytes;
}
return (0);
}
#endif /* EKCD */
static int
kerneldumpcomp_write_cb(void *base, size_t length, off_t offset, void *arg)
{
struct dumperinfo *di;
size_t resid, rlength;
int error;
di = arg;
if (length % di->blocksize != 0) {
/*
* This must be the final write after flushing the compression
* stream. Write as many full blocks as possible and stash the
* residual data in the dumper's block buffer. It will be
* padded and written in dump_finish().
*/
rlength = rounddown(length, di->blocksize);
if (rlength != 0) {
error = _dump_append(di, base, 0, rlength);
if (error != 0)
return (error);
}
resid = length - rlength;
memmove(di->blockbuf, (uint8_t *)base + rlength, resid);
di->kdcomp->kdc_resid = resid;
return (EAGAIN);
}
return (_dump_append(di, base, 0, length));
}
/*
* Write kernel dump headers at the beginning and end of the dump extent.
* Write the kernel dump encryption key after the leading header if we were
* configured to do so.
*/
static int
dump_write_headers(struct dumperinfo *di, struct kerneldumpheader *kdh)
{
#ifdef EKCD
struct kerneldumpcrypto *kdc;
#endif
void *buf, *key;
size_t hdrsz;
uint64_t extent;
uint32_t keysize;
int error;
hdrsz = sizeof(*kdh);
if (hdrsz > di->blocksize)
return (ENOMEM);
#ifdef EKCD
kdc = di->kdcrypto;
key = kdc->kdc_dumpkey;
keysize = kerneldumpcrypto_dumpkeysize(kdc);
#else
key = NULL;
keysize = 0;
#endif
/*
* If the dump device has special handling for headers, let it take care
* of writing them out.
*/
if (di->dumper_hdr != NULL)
return (di->dumper_hdr(di, kdh, key, keysize));
if (hdrsz == di->blocksize)
buf = kdh;
else {
buf = di->blockbuf;
memset(buf, 0, di->blocksize);
memcpy(buf, kdh, hdrsz);
}
extent = dtoh64(kdh->dumpextent);
#ifdef EKCD
if (kdc != NULL) {
error = dump_write(di, kdc->kdc_dumpkey, 0,
di->mediaoffset + di->mediasize - di->blocksize - extent -
keysize, keysize);
if (error != 0)
return (error);
}
#endif
error = dump_write(di, buf, 0,
di->mediaoffset + di->mediasize - 2 * di->blocksize - extent -
keysize, di->blocksize);
if (error == 0)
error = dump_write(di, buf, 0, di->mediaoffset + di->mediasize -
di->blocksize, di->blocksize);
return (error);
}
/*
* Don't touch the first SIZEOF_METADATA bytes on the dump device. This is to
* protect us from metadata and metadata from us.
*/
#define SIZEOF_METADATA (64 * 1024)
/*
* Do some preliminary setup for a kernel dump: initialize state for encryption,
* if requested, and make sure that we have enough space on the dump device.
*
* We set things up so that the dump ends before the last sector of the dump
* device, at which the trailing header is written.
*
* +-----------+------+-----+----------------------------+------+
* | | lhdr | key | ... kernel dump ... | thdr |
* +-----------+------+-----+----------------------------+------+
* 1 blk opt <------- dump extent --------> 1 blk
*
* Dumps written using dump_append() start at the beginning of the extent.
* Uncompressed dumps will use the entire extent, but compressed dumps typically
* will not. The true length of the dump is recorded in the leading and trailing
* headers once the dump has been completed.
*
* The dump device may provide a callback, in which case it will initialize
* dumpoff and take care of laying out the headers.
*/
int
dump_start(struct dumperinfo *di, struct kerneldumpheader *kdh)
{
uint64_t dumpextent, span;
uint32_t keysize;
int error;
#ifdef EKCD
error = kerneldumpcrypto_init(di->kdcrypto);
if (error != 0)
return (error);
keysize = kerneldumpcrypto_dumpkeysize(di->kdcrypto);
#else
error = 0;
keysize = 0;
#endif
if (di->dumper_start != NULL) {
error = di->dumper_start(di);
} else {
dumpextent = dtoh64(kdh->dumpextent);
span = SIZEOF_METADATA + dumpextent + 2 * di->blocksize +
keysize;
if (di->mediasize < span) {
if (di->kdcomp == NULL)
return (E2BIG);
/*
* We don't yet know how much space the compressed dump
* will occupy, so try to use the whole swap partition
* (minus the first 64KB) in the hope that the
* compressed dump will fit. If that doesn't turn out to
* be enough, the bounds checking in dump_write()
* will catch us and cause the dump to fail.
*/
dumpextent = di->mediasize - span + dumpextent;
kdh->dumpextent = htod64(dumpextent);
}
/*
* The offset at which to begin writing the dump.
*/
di->dumpoff = di->mediaoffset + di->mediasize - di->blocksize -
dumpextent;
}
di->origdumpoff = di->dumpoff;
return (error);
}
static int
_dump_append(struct dumperinfo *di, void *virtual, vm_offset_t physical,
size_t length)
{
int error;
#ifdef EKCD
if (di->kdcrypto != NULL)
error = dump_encrypted_write(di, virtual, physical, di->dumpoff,
length);
else
#endif
error = dump_write(di, virtual, physical, di->dumpoff, length);
if (error == 0)
di->dumpoff += length;
return (error);
}
/*
* Write to the dump device starting at dumpoff. When compression is enabled,
* writes to the device will be performed using a callback that gets invoked
* when the compression stream's output buffer is full.
*/
int
dump_append(struct dumperinfo *di, void *virtual, vm_offset_t physical,
size_t length)
{
void *buf;
if (di->kdcomp != NULL) {
/* Bounce through a buffer to avoid CRC errors. */
if (length > di->maxiosize)
return (EINVAL);
buf = di->kdcomp->kdc_buf;
memmove(buf, virtual, length);
return (compressor_write(di->kdcomp->kdc_stream, buf, length));
}
return (_dump_append(di, virtual, physical, length));
}
/*
* Write to the dump device at the specified offset.
*/
int
dump_write(struct dumperinfo *di, void *virtual, vm_offset_t physical,
off_t offset, size_t length)
{
int error;
error = dump_check_bounds(di, offset, length);
if (error != 0)
return (error);
return (di->dumper(di->priv, virtual, physical, offset, length));
}
/*
* Perform kernel dump finalization: flush the compression stream, if necessary,
* write the leading and trailing kernel dump headers now that we know the true
* length of the dump, and optionally write the encryption key following the
* leading header.
*/
int
dump_finish(struct dumperinfo *di, struct kerneldumpheader *kdh)
{
int error;
if (di->kdcomp != NULL) {
error = compressor_flush(di->kdcomp->kdc_stream);
if (error == EAGAIN) {
/* We have residual data in di->blockbuf. */
error = dump_write(di, di->blockbuf, 0, di->dumpoff,
di->blocksize);
di->dumpoff += di->kdcomp->kdc_resid;
di->kdcomp->kdc_resid = 0;
}
if (error != 0)
return (error);
/*
* We now know the size of the compressed dump, so update the
* header accordingly and recompute parity.
*/
kdh->dumplength = htod64(di->dumpoff - di->origdumpoff);
kdh->parity = 0;
kdh->parity = kerneldump_parity(kdh);
compressor_reset(di->kdcomp->kdc_stream);
}
error = dump_write_headers(di, kdh);
if (error != 0)
return (error);
(void)dump_write(di, NULL, 0, 0, 0);
return (0);
}
void
dump_init_header(const struct dumperinfo *di, struct kerneldumpheader *kdh,
char *magic, uint32_t archver, uint64_t dumplen)
{
size_t dstsize;
bzero(kdh, sizeof(*kdh));
strlcpy(kdh->magic, magic, sizeof(kdh->magic));
strlcpy(kdh->architecture, MACHINE_ARCH, sizeof(kdh->architecture));
kdh->version = htod32(KERNELDUMPVERSION);
kdh->architectureversion = htod32(archver);
kdh->dumplength = htod64(dumplen);
kdh->dumpextent = kdh->dumplength;
kdh->dumptime = htod64(time_second);
#ifdef EKCD
kdh->dumpkeysize = htod32(kerneldumpcrypto_dumpkeysize(di->kdcrypto));
#else
kdh->dumpkeysize = 0;
#endif
kdh->blocksize = htod32(di->blocksize);
strlcpy(kdh->hostname, prison0.pr_hostname, sizeof(kdh->hostname));
dstsize = sizeof(kdh->versionstring);
if (strlcpy(kdh->versionstring, version, dstsize) >= dstsize)
kdh->versionstring[dstsize - 2] = '\n';
if (panicstr != NULL)
strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
if (di->kdcomp != NULL)
kdh->compression = di->kdcomp->kdc_format;
kdh->parity = kerneldump_parity(kdh);
}
#ifdef DDB
DB_SHOW_COMMAND(panic, db_show_panic)
{
if (panicstr == NULL)
db_printf("panicstr not set\n");
else
db_printf("panic: %s\n", panicstr);
}
#endif
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