kexec-tools/kdumpctl

#!/bin/bash
KEXEC=/sbin/kexec

KDUMP_KERNELVER=""
KDUMP_COMMANDLINE=""
KEXEC_ARGS=""
KDUMP_CONFIG_FILE="/etc/kdump.conf"
MKDUMPRD="/sbin/mkdumprd -f"
SAVE_PATH=/var/crash
SSH_KEY_LOCATION="/root/.ssh/kdump_id_rsa"
INITRD_CHECKSUM_LOCATION="/boot/.fadump_initrd_checksum"
DUMP_TARGET=""
DEFAULT_INITRD=""
DEFAULT_INITRD_BAK=""
TARGET_INITRD=""
FADUMP_ENABLED_SYS_NODE="/sys/kernel/fadump_enabled"
FADUMP_REGISTER_SYS_NODE="/sys/kernel/fadump_registered"
#kdump shall be the default dump mode
DEFAULT_DUMP_MODE="kdump"
image_time=0

[[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut
. $dracutbasedir/dracut-functions.sh
. /lib/kdump/kdump-lib.sh

standard_kexec_args="-p"

# Some default values in case /etc/sysconfig/kdump doesn't include
KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug"

if [ -f /etc/sysconfig/kdump ]; then
	. /etc/sysconfig/kdump
fi

single_instance_lock()
{
	local rc timeout=5

	exec 9>/var/lock/kdump
	if [ $? -ne 0 ]; then
		echo "Create file lock failed"
		exit 1
	fi

	flock -n 9
	rc=$?

	while [ $rc -ne 0 ]; do
		echo "Another app is currently holding the kdump lock; waiting for it to exit..."
		flock -w $timeout 9
		rc=$?
	done
}

determine_dump_mode()
{
	# Check if firmware-assisted dump is enabled
	# if yes, set the dump mode as fadump
	if is_fadump_capable; then
		echo "Dump mode is fadump"
		DEFAULT_DUMP_MODE="fadump"
	fi
}

# remove_cmdline_param <kernel cmdline> <param1> [<param2>] ... [<paramN>]
# Remove a list of kernel parameters from a given kernel cmdline and print the result.
# For each "arg" in the removing params list, "arg" and "arg=xxx" will be removed if exists.
remove_cmdline_param()
{
	local cmdline=$1
	shift

	for arg in $@; do
		cmdline=`echo $cmdline | \
			 sed -e "s/\b$arg=[^ ]*//g" \
			     -e "s/^$arg\b//g" \
			     -e "s/[[:space:]]$arg\b//g" \
			     -e "s/\s\+/ /g"`
	done
	echo $cmdline
}

#
# This function returns the "initial apicid" of the
# boot cpu (cpu 0) if present.
#
get_bootcpu_initial_apicid()
{
    awk '							\
	BEGIN { CPU = "-1"; }					\
	$1=="processor" && $2==":"	{ CPU = $NF; }		\
	CPU=="0" && /initial apicid/	{ print $NF; }		\
	'							\
	/proc/cpuinfo
}

#
# This function appends argument "$2=$3" to string ($1) if not already present.
#
append_cmdline()
{
	local cmdline=$1
	local newstr=${cmdline/$2/""}

	# unchanged str implies argument wasn't there
	if [ "$cmdline" == "$newstr" ]; then
		cmdline="${cmdline} ${2}=${3}"
	fi

	echo $cmdline
}

# Check the number of cpus for kdump kernel to boot with.
# We met an issue on x86_64: kdump runs out of vectors with
# "nr_cpus=1" when requesting tons of irqs, so here we check
# "nr_cpus=1" and warn users if kdump probably can't work.
check_kdump_cpus()
{
	local nr_origin nr_min nr_max
	local arch=$(uname -m) cmdline=$KDUMP_COMMANDLINE_APPEND

	if [ $arch != "x86_64" ]; then
		return
	fi

	# We only care about the default "nr_cpus=1".
	echo $cmdline | grep -E -q "nr_cpus=1[[:space:]]*|nr_cpus=1$"
	if [ $? -ne 0 ]; then
		return
	fi

	nr_origin=1

	# Online cpus in first kernel.
	nr_max=$(grep -c '^processor' /proc/cpuinfo)

	# To calculate the estimated minimal cpus required.
	nr_min=$(ls -ld /proc/irq/*/ | wc -l)

	# Vectors for io device start from FIRST_EXTERNAL_VECTOR(32),
	# some high-numbered ones starting from FIRST_EXTERNAL_VECTOR
	# are reserved for system internal uses.
	#
	# We use a flexible variance and assume there are 32 reserved
	# from FIRST_EXTERNAL_VECTOR. Then the total vectors for device
	# interrupts percpu is: (256-32)-32=192.
	#
	# For "nr_cpus=1", irq and vector have the 1:1 mapping.
	nr_min=$(($nr_min + 192 - 1))
	nr_min=$(($nr_min / 192))
	if [ $nr_min -gt 1 ]; then
		# The system seems to have tons of interrupts. We need
		# some further calculation of the number of cpus(>1).
		# For "nr_cpus>1", irq and vector have the 1:M mapping,
		# multiple-cpu affinity can consume multiple vectors.
		# Luckily for x2apic which is commonly deployed on large
		# modern machines, default case of boot, device bringup
		# etc will use a single cpu to minimize vector pressure.
		#
		# For further safety, we add one more cpu and round it
		# up to an even number.
		nr_min=$(($nr_min + 1))
		nr_min=$(($nr_min + $nr_min % 2))
	fi

	if [ $nr_min -gt $nr_max ]; then
		nr_min=$nr_max
	fi

	if [ $nr_origin -ge $nr_min ]; then
		return
	fi

	echo -n "Warning: nr_cpus=1 may not be enough for kdump boot,"
	echo " try nr_cpus=$nr_min or larger instead"
}

# This function performs a series of edits on the command line.
# Store the final result in global $KDUMP_COMMANDLINE.
prepare_cmdline()
{
	local cmdline id

	if [ -z "$KDUMP_COMMANDLINE" ]; then
		cmdline=`cat /proc/cmdline`
	else
		cmdline=${KDUMP_COMMANDLINE}
	fi

	# These params should always be removed
	cmdline=`remove_cmdline_param "$cmdline" crashkernel panic_on_warn`
	# These params can be removed configurably
	cmdline=`remove_cmdline_param "$cmdline" ${KDUMP_COMMANDLINE_REMOVE}`

	# Always remove "root=X", as we now explicitly generate all kinds
	# of dump target mount information including root fs. But we can
	# not remove it in case of fadump or "default dump_to_rootfs".
	#
	# We do this before KDUMP_COMMANDLINE_APPEND, if one really cares
	# about it(e.g. for debug purpose), then can pass "root=X" using
	# KDUMP_COMMANDLINE_APPEND.
	if [ $DEFAULT_DUMP_MODE != "fadump" ] && ! is_dump_to_rootfs; then
		cmdline=`remove_cmdline_param "$cmdline" root`
	fi

	cmdline="${cmdline} ${KDUMP_COMMANDLINE_APPEND}"

	id=`get_bootcpu_initial_apicid`
	if [ ! -z ${id} ] ; then
		cmdline=`append_cmdline "${cmdline}" disable_cpu_apicid ${id}`
	fi

	KDUMP_COMMANDLINE=$cmdline

	check_kdump_cpus
}


save_core()
{
	coredir="/var/crash/`date +"%Y-%m-%d-%H:%M"`"

	mkdir -p $coredir
	cp --sparse=always /proc/vmcore $coredir/vmcore-incomplete
	if [ $? == 0 ]; then
		mv $coredir/vmcore-incomplete $coredir/vmcore
		echo "saved a vmcore to $coredir"
	else
		echo "failed to save a vmcore to $coredir" >&2
	fi

	# pass the dmesg to Abrt tool if exists, in order
	# to collect the kernel oops message.
	# https://fedorahosted.org/abrt/
	if [ -x /usr/bin/dumpoops ]; then
		makedumpfile --dump-dmesg $coredir/vmcore $coredir/dmesg >/dev/null 2>&1
		dumpoops -d $coredir/dmesg >/dev/null 2>&1
		if [ $? == 0 ]; then
			echo "kernel oops has been collected by abrt tool"
		fi
	fi
}

rebuild_fadump_initrd()
{
	local target_initrd_tmp

	# this file tells the initrd is fadump enabled
	touch /tmp/fadump.initramfs
	target_initrd_tmp="$TARGET_INITRD.tmp"
	$MKDUMPRD $target_initrd_tmp --rebuild $TARGET_INITRD --kver $kdump_kver \
		-i /tmp/fadump.initramfs /etc/fadump.initramfs
	if [ $? != 0 ]; then
		echo "mkdumprd: failed to rebuild initrd with fadump support" >&2
		rm -f /tmp/fadump.initramfs
		return 1
	fi
	rm -f /tmp/fadump.initramfs

	# updating fadump initrd
	mv $target_initrd_tmp $TARGET_INITRD
	sync

	return 0
}

rebuild_kdump_initrd()
{
	$MKDUMPRD $TARGET_INITRD $kdump_kver
	if [ $? != 0 ]; then
		echo "mkdumprd: failed to make kdump initrd" >&2
		return 1
	fi

	return 0
}

rebuild_initrd()
{
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		rebuild_fadump_initrd
	else
		rebuild_kdump_initrd
	fi

	return $?
}

#$1: the files to be checked with IFS=' '
check_exist()
{
	for file in $1; do
		if [ ! -f "$file" ]; then
			echo -n "Error: $file not found."; echo
			return 1
		fi
	done
}

#$1: the files to be checked with IFS=' '
check_executable()
{
	for file in $1; do
		if [ ! -x "$file" ]; then
			echo -n "Error: $file is not executable."; echo
			return 1
		fi
	done
}

backup_default_initrd()
{
	if [ ! -f "$DEFAULT_INITRD" ]; then
		return
	fi

	if [ ! -e $DEFAULT_INITRD_BAK ]; then
		echo "Backing up $DEFAULT_INITRD before rebuild."
		# save checksum to verify before restoring
		sha1sum $DEFAULT_INITRD > $INITRD_CHECKSUM_LOCATION
		cp $DEFAULT_INITRD $DEFAULT_INITRD_BAK
		if [ $? -ne 0 ]; then
			echo "WARNING: failed to backup $DEFAULT_INITRD."
			rm -f $DEFAULT_INITRD_BAK
		fi
	fi
}

restore_default_initrd()
{
	# If a backup initrd exists, we must be switching back from
	# fadump to kdump. Restore the original default initrd.
	if [ -f $DEFAULT_INITRD_BAK ] && [ -f $INITRD_CHECKSUM_LOCATION ]; then
		# verify checksum before restoring
		backup_checksum=`sha1sum $DEFAULT_INITRD_BAK | awk '{ print $1 }'`
		default_checksum=`cat $INITRD_CHECKSUM_LOCATION | awk '{ print $1 }'`
		if [ "$default_checksum" != "$backup_checksum" ]; then
			echo "WARNING: checksum mismatch! Can't restore original initrd.."
		else
			rm -f $INITRD_CHECKSUM_LOCATION
			mv $DEFAULT_INITRD_BAK $DEFAULT_INITRD
			if [[ $? -eq 0 ]]; then
				echo -n "Restoring original initrd as fadump mode "
				echo "is disabled."
				sync
			fi
		fi
	fi
}

check_config()
{
	local nr

	nr=$(awk 'BEGIN{cnt=0} /^raw|^ssh[[:blank:]]|^nfs|^ext[234]|^xfs|^btrfs|^minix|^dracut_args .*\-\-mount/{cnt++} END{print cnt}' $KDUMP_CONFIG_FILE)
	[ $nr -gt 1 ] && {
		echo "More than one dump targets specified."
		return 1
	}

	nr=$(grep "^dracut_args .*\-\-mount" $KDUMP_CONFIG_FILE | grep -o "\-\-mount" | wc -l)
	[ $nr -gt 1 ] && {
		echo "Multiple mount targets specified in one \"dracut_args\"."
		return 1
	}

	while read config_opt config_val; do
		case "$config_opt" in
		\#* | "")
			;;
		raw|ext2|ext3|ext4|minix|btrfs|xfs|nfs|ssh|sshkey|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|default|force_rebuild|force_no_rebuild|dracut_args|fence_kdump_args|fence_kdump_nodes)
			# remove inline comments after the end of a directive.
			config_val=$(strip_comments $config_val)
			[ -z "$config_val" ] && {
				echo "Invalid kdump config value for option $config_opt."
				return 1;
			}
			;;
		net|options|link_delay|disk_timeout|debug_mem_level|blacklist)
			echo "Deprecated kdump config option: $config_opt. Refer to kdump.conf manpage for alternatives."
			return 1
			;;
		*)
			echo "Invalid kdump config option $config_opt"
			return 1;
			;;
		esac
	done < $KDUMP_CONFIG_FILE

	check_default_config || return 1

	check_fence_kdump_config || return 1

	return 0
}

# get_pcs_cluster_modified_files <image timestamp>
# return list of modified file for fence_kdump modified in Pacemaker cluster
get_pcs_cluster_modified_files()
{
	local time_stamp
	local modified_files

	is_generic_fence_kdump && return 1
	is_pcs_fence_kdump || return 1

	time_stamp=`pcs cluster cib | xmllint --xpath 'string(/cib/@cib-last-written)' - | \
		xargs -0 date +%s --date`

	if [ -n $time_stamp -a $time_stamp -gt $image_time ]; then
		modified_files="cluster-cib"
	fi

	if [ -f $FENCE_KDUMP_CONFIG_FILE ]; then
		time_stamp=`stat -c "%Y" $FENCE_KDUMP_CONFIG_FILE`
		if [ "$time_stamp" -gt "$image_time" ]; then
			modified_files="$modified_files $FENCE_KDUMP_CONFIG_FILE"
		fi
	fi

	echo $modified_files
}

check_boot_dir()
{
	#If user specify a boot dir for kdump kernel, let's use it. Otherwise
	#check whether it's a atomic host. If yes parse the subdirectory under
	#/boot; If not just find it under /boot.
	[ -n "$KDUMP_BOOTDIR" ] && return

	if ! is_atomic || [ "$(uname -m)" = "s390x" ]; then
		KDUMP_BOOTDIR="/boot"
	else
		eval $(cat /proc/cmdline| grep "BOOT_IMAGE" | cut -d' ' -f1)
		KDUMP_BOOTDIR="/boot"$(dirname $BOOT_IMAGE)
	fi
}

setup_initrd()
{
	DEFAULT_INITRD="${KDUMP_BOOTDIR}/initramfs-`uname -r`.img"
	DEFAULT_INITRD_BAK="${KDUMP_BOOTDIR}/.initramfs-`uname -r`.img.default"
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		TARGET_INITRD="$DEFAULT_INITRD"
		if [ ! -s "$TARGET_INITRD" ]; then
			echo "Error: No initrd found to rebuild!"
			return 1
		fi
	else
		TARGET_INITRD="${KDUMP_BOOTDIR}/initramfs-${kdump_kver}kdump.img"
	fi
}

check_files_modified()
{
	local modified_files=""

	#also rebuild when Pacemaker cluster conf is changed and fence kdump is enabled.
	modified_files=$(get_pcs_cluster_modified_files)

	EXTRA_BINS=`grep ^kdump_post $KDUMP_CONFIG_FILE | cut -d\  -f2`
	CHECK_FILES=`grep ^kdump_pre $KDUMP_CONFIG_FILE | cut -d\  -f2`
	EXTRA_BINS="$EXTRA_BINS $CHECK_FILES"
	CHECK_FILES=`grep ^extra_bins $KDUMP_CONFIG_FILE | cut -d\  -f2-`
	EXTRA_BINS="$EXTRA_BINS $CHECK_FILES"
	files="$KDUMP_CONFIG_FILE $kdump_kernel $EXTRA_BINS"
	[[ -e /etc/fstab ]] && files="$files /etc/fstab"

	check_exist "$files" && check_executable "$EXTRA_BINS"
	[ $? -ne 0 ] && return 2

	for file in $files; do
		time_stamp=`stat -c "%Y" $file`
		if [ "$time_stamp" -gt "$image_time" ]; then
			modified_files="$modified_files $file"
		fi
	done
	if [ -n "$modified_files" ]; then
		echo "Detected change(s) in the following file(s):"
		echo -n "  "; echo "$modified_files" | sed 's/\s/\n  /g'
		return 1
	fi

	return 0
}

check_dump_fs_modified()
{
	local _old_dev _old_mntpoint _old_fstype
	local _new_dev _new_mntpoint _new_fstype
	local _target _path _dracut_args

	# No need to check in case of mount target specified via "dracut_args".
	if is_mount_in_dracut_args; then
		return 0
	fi

	# No need to check in case of raw target.
	# Currently we do not check also if ssh/nfs target is specified
	if is_ssh_dump_target || is_nfs_dump_target || is_raw_dump_target; then
		return 0
	fi

	_target=$(get_user_configured_dump_disk)

	if [[ -n "$_target" ]]; then
		_target=$(to_dev_name $_target)
		_new_fstype=$(blkid $_target | awk -F"TYPE=" '{print $2}' | cut -d '"' -f 2)
	else
		_path=$(get_save_path)
		_target=$(get_target_from_path $_path)
		_target=$(to_dev_name $_target)
		_new_fstype=$(get_fs_type_from_target $_target)
		if [[ -z "$_target" || -z "$_new_fstype" ]];then
			echo "Dump path $_path does not exist"
			return 2
		fi
	fi

	if [[ $(expr substr $_new_fstype 1 3) = "nfs" ]];then
		_new_dev=$_target
	else
		_new_dev=$(get_persistent_dev $_target)
		if [ -z "$_new_dev" ]; then
			echo "Get persistent device name failed"
			return 2
		fi
	fi

	if ! findmnt $_target >/dev/null; then
		echo "Dump target $_target is probably not mounted."
		return 2
	fi

	if [[ "$_target" = "$(get_root_fs_device)" ]]; then
		_new_mntpoint="/sysroot"
	else
		_new_mntpoint="/kdumproot/$(get_mntpoint_from_target $_target)"
	fi

	_dracut_args=$(lsinitrd $TARGET_INITRD -f usr/lib/dracut/build-parameter.txt)
	if [[ -z "$_dracut_args" ]];then
		echo "Warning: No dracut arguments found in initrd"
		return 0
	fi

	# if --mount argument present then match old and new target, mount
	# point and file system. If any of them mismatches then rebuild
	echo $_dracut_args | grep "\-\-mount" &> /dev/null
	if [[ $? -eq 0 ]];then
		set -- $(echo $_dracut_args | awk -F "--mount '" '{print $2}' | cut -d' ' -f1,2,3)
		_old_dev=$1
		_old_mntpoint=$2
		_old_fstype=$3
		[[ $_new_dev = $_old_dev && $_new_mntpoint = $_old_mntpoint && $_new_fstype = $_old_fstype ]] && return 0
	# otherwise rebuild if target device is not a root device
	else
		[[ "$_target" = "$(get_root_fs_device)" ]] && return 0
	fi

	echo "Detected change in File System"
	return 1
}

check_wdt_modified()
{
	local -A _drivers
	local _alldrivers _active _wdtdrv _wdtppath _dir
	local wd_old wd_new

	is_wdt_mod_omitted
	[[ $? -eq 0 ]] && return 0
	[[ -d /sys/class/watchdog/ ]] || return 0

	# Copied logic from dracut 04watchdog/module-setup.sh::installkernel()
	for _dir in /sys/class/watchdog/*; do
		[[ -d "$_dir" ]] || continue
		[[ -f "$_dir/state" ]] || continue
		_active=$(< "$_dir/state")
		[[ "$_active" =  "active" ]] || continue
		# device/modalias will return driver of this device
		_wdtdrv=$(< "$_dir/device/modalias")
		# There can be more than one module represented by same
		# modalias. Currently load all of them.
		# TODO: Need to find a way to avoid any unwanted module
		# represented by modalias
		_wdtdrv=$(modprobe --set-version "$kdump_kver" -R $_wdtdrv 2>/dev/null)
		if [[ $_wdtdrv ]]; then
			for i in $_wdtdrv; do
				_drivers[$i]=1
			done
		fi
		# however in some cases, we also need to check that if there is
		# a specific driver for the parent bus/device.  In such cases
		# we also need to enable driver for parent bus/device.
		_wdtppath=$(readlink -f "$_dir/device")
		while [[ -d "$_wdtppath" ]] && [[ "$_wdtppath" != "/sys" ]]; do
			_wdtppath=$(readlink -f "$_wdtppath/..")
			[[ -f "$_wdtppath/modalias" ]] || continue

			_wdtdrv=$(< "$_wdtppath/modalias")
			_wdtdrv=$(modprobe --set-version "$kdump_kver" -R $_wdtdrv 2>/dev/null)
			if [[ $_wdtdrv ]]; then
				for i in $_wdtdrv; do
					_drivers[$i]=1
				done
			fi
		done
	done

	# ensure that watchdog module is loaded as early as possible
	_alldrivers="${!_drivers[*]}"
	[[ $_alldrivers ]] && wd_new="rd.driver.pre=${_alldrivers// /,}"
	wd_old=$(lsinitrd $TARGET_INITRD -f etc/cmdline.d/00-watchdog.conf)

	[[ "$wd_old" = "$wd_new" ]] && return 0

	return 1
}

# returns 0 if system is not modified
# returns 1 if system is modified
# returns 2 if system modification is invalid
check_system_modified()
{
	local ret

	[[ -f $TARGET_INITRD ]] || return 1

	check_files_modified
	ret=$?
	if [ $ret -ne 0 ]; then
		return $ret
	fi

	check_dump_fs_modified
	ret=$?
	if [ $ret -ne 0 ]; then
		return $ret
	fi

	check_wdt_modified
	if [ $? -ne 0 ]; then
		echo "Detected change in watchdog state"
		return 1
	fi

	return 0
}

check_rebuild()
{
	local extra_modules
	local _force_rebuild force_rebuild="0"
	local _force_no_rebuild force_no_rebuild="0"
	local ret system_modified="0"

	check_boot_dir

	if [ -z "$KDUMP_KERNELVER" ]; then
		kdump_kver=`uname -r`
	else
		kdump_kver=$KDUMP_KERNELVER
	fi

	kdump_kernel="${KDUMP_BOOTDIR}/${KDUMP_IMG}-${kdump_kver}${KDUMP_IMG_EXT}"
	setup_initrd
	if [ $? -ne 0 ]; then
		return 1
	fi

	_force_no_rebuild=`grep ^force_no_rebuild $KDUMP_CONFIG_FILE 2>/dev/null`
	if [ $? -eq 0 ]; then
		force_no_rebuild=`echo $_force_no_rebuild | cut -d' '  -f2`
		if [ "$force_no_rebuild" != "0" ] && [ "$force_no_rebuild" != "1" ];then
			echo "Error: force_no_rebuild value is invalid"
			return 1
		fi
	fi

	_force_rebuild=`grep ^force_rebuild $KDUMP_CONFIG_FILE 2>/dev/null`
	if [ $? -eq 0 ]; then
		force_rebuild=`echo $_force_rebuild | cut -d' '  -f2`
		if [ "$force_rebuild" != "0" ] && [ "$force_rebuild" != "1" ];then
			echo "Error: force_rebuild value is invalid"
			return 1
		fi
	fi

	if [[ "$force_no_rebuild" == "1" && "$force_rebuild" == "1" ]]; then
		echo "Error: force_rebuild and force_no_rebuild are enabled simultaneously in kdump.conf"
		return 1
	fi

	# Will not rebuild kdump initrd
	if [ "$force_no_rebuild" == "1" ]; then
		return 0
	fi

	#will rebuild every time if extra_modules are specified
	extra_modules=`grep ^extra_modules $KDUMP_CONFIG_FILE`
	[ -n "$extra_modules" ] && force_rebuild="1"

	#check to see if dependent files has been modified
	#since last build of the image file
	if [ -f $TARGET_INITRD ]; then
		image_time=`stat -c "%Y" $TARGET_INITRD 2>/dev/null`
	fi

	check_system_modified
	ret=$?
	if [ $ret -eq 2 ]; then
		return 1
	elif [ $ret -eq 1 ];then
		system_modified="1"
	fi

	handle_mode_switch

	if [ $image_time -eq 0 ]; then
		echo  -n "No kdump initial ramdisk found."; echo
	elif [ "$force_rebuild" != "0" ]; then
		echo -n "Force rebuild $TARGET_INITRD"; echo
	elif [ "$system_modified" != "0" ]; then
		:
	else
		return 0
	fi

	if [[ ! -w "$KDUMP_BOOTDIR" ]];then
		echo "$KDUMP_BOOTDIR does not have write permission. Can not rebuild $TARGET_INITRD"
		return 1
	fi

	echo "Rebuilding $TARGET_INITRD"
	rebuild_initrd
	return $?
}

# This function check iomem and determines if we have more than
# 4GB of ram available. Returns 1 if we do, 0 if we dont
need_64bit_headers()
{
	return `tail -n 1 /proc/iomem | awk '{ split ($1, r, "-"); \
	print (strtonum("0x" r[2]) > strtonum("0xffffffff")); }'`
}

# Load the kdump kernel specified in /etc/sysconfig/kdump
# If none is specified, try to load a kdump kernel with the same version
# as the currently running kernel.
load_kdump()
{
	ARCH=`uname -m`
	if [ "$ARCH" == "i686" -o "$ARCH" == "i386" ]
	then

		need_64bit_headers
		if [ $? == 1 ]
		then
			FOUND_ELF_ARGS=`echo $KEXEC_ARGS | grep elf32-core-headers`
			if [ -n "$FOUND_ELF_ARGS" ]
			then
				echo -n "Warning: elf32-core-headers overrides correct elf64 setting"
				echo
			else	
				KEXEC_ARGS="$KEXEC_ARGS --elf64-core-headers"
			fi
		else
			FOUND_ELF_ARGS=`echo $KEXEC_ARGS | grep elf64-core-headers`
			if [ -z "$FOUND_ELF_ARGS" ]
			then
				KEXEC_ARGS="$KEXEC_ARGS --elf32-core-headers"
			fi
		fi
	fi

	prepare_cmdline

	# For secureboot enabled machines, use new kexec file based syscall.
	# Old syscall will always fail as it does not have capability to
	# to kernel signature verification.
	if is_secure_boot_enforced; then
		echo "Secure Boot is enabled. Using kexec file based syscall."
		KEXEC_ARGS="$KEXEC_ARGS -s"
	fi

	$KEXEC $KEXEC_ARGS $standard_kexec_args \
		--command-line="$KDUMP_COMMANDLINE" \
		--initrd=$TARGET_INITRD $kdump_kernel
	if [ $? == 0 ]; then
		echo "kexec: loaded kdump kernel"
		return 0
	else
		echo "kexec: failed to load kdump kernel" >&2
		return 1
	fi
}

check_ssh_config()
{
	while read config_opt config_val; do
		case "$config_opt" in
		sshkey)
			# remove inline comments after the end of a directive.
			config_val=$(strip_comments $config_val)
			if [ -f "$config_val" ]; then
				# canonicalize the path
				SSH_KEY_LOCATION=$(/usr/bin/readlink -m $config_val)
			else
				echo "WARNING: '$config_val' doesn't exist, using default value '$SSH_KEY_LOCATION'"
			fi
			;;
		path)
			config_val=$(strip_comments $config_val)
			SAVE_PATH=$config_val
			;;
		ssh)
			config_val=$(strip_comments $config_val)
			DUMP_TARGET=$config_val
			;;
		*)
			;;
		esac
	done < $KDUMP_CONFIG_FILE

	#make sure they've configured kdump.conf for ssh dumps
	local SSH_TARGET=`echo -n $DUMP_TARGET | sed -n '/.*@/p'`
	if [ -z "$SSH_TARGET" ]; then
		return 1
	fi
	return 0
}

check_ssh_target()
{
	local _ret
	ssh -q -i $SSH_KEY_LOCATION -o BatchMode=yes $DUMP_TARGET mkdir -p $SAVE_PATH
	_ret=$?
	if [ $_ret -ne 0 ]; then
		echo "Could not create $DUMP_TARGET:$SAVE_PATH, you probably need to run \"kdumpctl propagate\""  >&2
		return 1
	fi
	return 0
}

propagate_ssh_key()
{
	check_ssh_config
	if [ $? -ne 0 ]; then
		echo "No ssh config specified in $KDUMP_CONFIG_FILE.  Can't propagate" >&2
		exit 1
	fi

	local KEYFILE=$SSH_KEY_LOCATION
	local errmsg="Failed to propagate ssh key"

	#Check to see if we already created key, if not, create it.
	if [ -f $KEYFILE ]; then
		echo "Using existing keys..."
	else
		echo -n "Generating new ssh keys... "
		/usr/bin/ssh-keygen -t rsa -f $KEYFILE -N "" 2>&1 > /dev/null
		echo "done."
	fi

	#now find the target ssh user and server to contact.
	SSH_USER=`echo $DUMP_TARGET | cut -d\  -f2 | cut -d@ -f1`
	SSH_SERVER=`echo $DUMP_TARGET | sed -e's/\(.*@\)\(.*$\)/\2/'`

	#now send the found key to the found server
	ssh-copy-id -i $KEYFILE $SSH_USER@$SSH_SERVER
	RET=$?
	if [ $RET == 0 ]; then
		echo $KEYFILE has been added to ~$SSH_USER/.ssh/authorized_keys on $SSH_SERVER
		return 0
	else
		echo $errmsg, $KEYFILE failed in transfer to $SSH_SERVER  >&2
		exit 1
	fi
}

handle_mode_switch()
{
	if [ "$DEFAULT_DUMP_MODE" == "fadump" ]; then
		# backup initrd for reference before replacing it
		# with fadump aware initrd
		backup_default_initrd
	else
		# check if a backup of default initrd exists. If yes,
		# it signifies a switch from fadump mode. So, restore
		# the backed up default initrd.
		restore_default_initrd
	fi
}

is_fadump_capable()
{
	# Check if firmware-assisted dump is enabled
	# if no, fallback to kdump check
	if [ -f $FADUMP_ENABLED_SYS_NODE ]; then
		rc=`cat $FADUMP_ENABLED_SYS_NODE`
		[ $rc -eq 1 ] && return 0
	fi
	return 1
}

check_current_fadump_status()
{
	# Check if firmware-assisted dump has been registered.
	rc=`cat $FADUMP_REGISTER_SYS_NODE`
	[ $rc -eq 1 ] && return 0
	return 1
}

check_current_kdump_status()
{
	if [ ! -f /sys/kernel/kexec_crash_loaded ];then
		echo "Perhaps CONFIG_CRASH_DUMP is not enabled in kernel"
		return 1
	fi

	rc=`cat /sys/kernel/kexec_crash_loaded`
	if [ $rc == 1 ]; then
		return 0
	else
		return 1
	fi
}

check_current_status()
{
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		check_current_fadump_status
	else
		check_current_kdump_status
	fi

	return $?
}

save_raw()
{
	local kdump_dir
	local raw_target

	raw_target=$(awk '$1 ~ /^raw$/ { print $2; }' $KDUMP_CONFIG_FILE)
	[ -z "$raw_target" ] && return 0
	[ -b "$raw_target" ] || {
		echo "raw partition $raw_target not found"
		return 1
	}
	kdump_dir=`grep ^path $KDUMP_CONFIG_FILE | cut -d' '  -f2-`
	if [ -z "${kdump_dir}" ]; then
		coredir="/var/crash/`date +"%Y-%m-%d-%H:%M"`"
	else
		coredir="${kdump_dir}/`date +"%Y-%m-%d-%H:%M"`"
	fi

	mkdir -p "$coredir"
	[ -d "$coredir" ] || {
		echo "failed to create $coredir"
		return 1
	}
	if makedumpfile -R $coredir/vmcore <$raw_target >/dev/null 2>&1; then
		# dump found
		echo "Dump saved to $coredir/vmcore"
		# wipe makedumpfile header
		dd if=/dev/zero of=$raw_target bs=1b count=1 2>/dev/null
	else
		rm -rf "$coredir"
	fi

	return 0
}

is_dump_target_configured()
{
	local _target

	_target=$(egrep "^ext[234]|^xfs|^btrfs|^minix|^raw|^ssh|^nfs" /etc/kdump.conf)

	[ -n "$_target" ]
}

local_fs_dump_target()
{
	local _target

	_target=$(egrep "^ext[234]|^xfs|^btrfs|^minix" /etc/kdump.conf)
	if [ $? -eq 0 ]; then
		echo $_target|awk '{print $2}'
	fi
}

path_to_be_relabeled()
{
	local _path _target _mnt="/" _rmnt

	if is_dump_target_configured; then
		_target=$(local_fs_dump_target)
		if [[ -n "$_target" ]]; then
			_mnt=$(findmnt -k -f -n -r -o TARGET $_target)
			if [ -z "$_mnt" ]; then
				return
			fi
		else
			return
		fi
	fi

	_path=$(get_save_path)
	# if $_path is masked by other mount, we will not relabel it.
	_rmnt=$(df $_mnt/$_path 2>/dev/null | tail -1 | awk '{ print $NF }')
	if [ "$_rmnt" == "$_mnt" ]; then
		echo $_mnt/$_path
	fi
}

selinux_relabel()
{
	local _path _i _attr

	_path=$(path_to_be_relabeled)
	if [ -z "$_path" ] || ! [ -d "$_path" ] ; then
		return
	fi

	for _i in $(find $_path); do
		_attr=$(getfattr -m "security.selinux" $_i 2>/dev/null)
		if [ -z "$_attr" ]; then
			restorecon $_i;
		fi
	done
}

# Check if secure boot is being enforced.
#
# Per Peter Jones, we need check efivar SecureBoot-$(the UUID) and
# SetupMode-$(the UUID), they are both 5 bytes binary data. The first four
# bytes are the attributes associated with the variable and can safely be
# ignored, the last bytes are one-byte true-or-false variables. If SecureBoot
# is 1 and SetupMode is 0, then secure boot is being enforced.
#
# Assume efivars is mounted at /sys/firmware/efi/efivars.
is_secure_boot_enforced()
{
	local secure_boot_file setup_mode_file
	local secure_boot_byte setup_mode_byte

	secure_boot_file=$(find /sys/firmware/efi/efivars -name SecureBoot-* 2>/dev/null)
	setup_mode_file=$(find /sys/firmware/efi/efivars -name SetupMode-* 2>/dev/null)

	if [ -f "$secure_boot_file" ] && [ -f "$setup_mode_file" ]; then
		secure_boot_byte=$(hexdump -v -e '/1 "%d\ "' $secure_boot_file|cut -d' ' -f 5)
		setup_mode_byte=$(hexdump -v -e '/1 "%d\ "' $setup_mode_file|cut -d' ' -f 5)

		if [ "$secure_boot_byte" = "1" ] && [ "$setup_mode_byte" = "0" ]; then
			return 0
		fi
	fi

	return 1
}

check_crash_mem_reserved()
{
	local mem_reserved

	mem_reserved=$(cat /sys/kernel/kexec_crash_size)
	if [ $mem_reserved -eq 0 ]; then
		echo "No memory reserved for crash kernel"
		return 1
	fi

	return 0
}

check_kdump_feasibility()
{
	if [ ! -e /sys/kernel/kexec_crash_loaded ]; then
		echo "Kdump is not supported on this kernel"
		return 1
	fi
	check_crash_mem_reserved
	return $?
}

check_fence_kdump_config()
{
	local hostname=`hostname`
	local ipaddrs=`hostname -I`
	local nodes=$(get_option_value "fence_kdump_nodes")

	for node in $nodes; do
		if [ "$node" = "$hostname" ]; then
			echo "Option fence_kdump_nodes cannot contain $hostname"
			return 1
		fi
		# node can be ipaddr
		echo $ipaddrs | grep $node > /dev/null
		if [ $? -eq 0 ]; then
			echo "Option fence_kdump_nodes cannot contain $node"
			return 1
		fi
	done

	return 0
}

check_dump_feasibility()
{
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		return 0
	fi

	check_kdump_feasibility
	return $?
}

start_fadump()
{
	echo 1 > $FADUMP_REGISTER_SYS_NODE
	if ! check_current_fadump_status; then
		echo "fadump: failed to register"
		return 1
	fi

	echo "fadump: registered successfully"
	return 0
}

start_dump()
{
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		start_fadump
	else
		load_kdump
	fi

	return $?
}

check_default_config()
{
	local default_option

	default_option=$(awk '$1 ~ /^default$/ {print $2;}' $KDUMP_CONFIG_FILE)
	if [ -z "$default_option" ]; then
		return 0
	else
		case "$default_option" in
		  reboot|halt|poweroff|shell|dump_to_rootfs)
			return 0
		  ;;
		  *)
			echo $"Usage kdump.conf: default {reboot|halt|poweroff|shell|dump_to_rootfs}"
			return 1
		esac
	fi
}

start()
{
	check_dump_feasibility
	if [ $? -ne 0 ]; then
		echo "Starting kdump: [FAILED]"
		return 1
	fi

	check_config
	if [ $? -ne 0 ]; then
		echo "Starting kdump: [FAILED]"
		return 1
	fi

	if sestatus 2>/dev/null | grep -q "SELinux status.*enabled"; then
		selinux_relabel
	fi

	save_raw
	if [ $? -ne 0 ]; then
		echo "Starting kdump: [FAILED]"
		return 1
	fi

	check_current_status
	if [ $? == 0 ]; then
		echo "Kdump already running: [WARNING]"
		return 0
	fi

	if check_ssh_config; then
		if ! check_ssh_target; then
			echo "Starting kdump: [FAILED]"
			return 1
		fi
	fi

	check_rebuild
	if [ $? != 0 ]; then
		echo "Starting kdump: [FAILED]"
		return 1
	fi

	start_dump
	if [ $? != 0 ]; then
		echo "Starting kdump: [FAILED]"
		return 1
	fi

	echo "Starting kdump: [OK]"
}

stop_fadump()
{
	echo 0 > $FADUMP_REGISTER_SYS_NODE
	if check_current_fadump_status; then
		echo "fadump: failed to unregister"
		return 1
	fi

	echo "fadump: unregistered successfully"
	return 0
}

stop_kdump()
{
	if is_secure_boot_enforced; then
		$KEXEC -s -p -u
	else
		$KEXEC -p -u
	fi

	if [ $? != 0 ]; then
		echo "kexec: failed to unload kdump kernel"
		return 1
	fi

	echo "kexec: unloaded kdump kernel"
	return 0
}

stop()
{
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		stop_fadump
	else
		stop_kdump
	fi

	if [ $? != 0 ]; then
		echo "Stopping kdump: [FAILED]"
		return 1
	fi

	echo "Stopping kdump: [OK]"
	return 0
}

if [ ! -f "$KDUMP_CONFIG_FILE" ]; then
	echo "Error: No kdump config file found!"  >&2
	exit 1
fi

main ()
{
	# Determine if the dump mode is kdump or fadump
	determine_dump_mode

	case "$1" in
	  start)
		if [ -s /proc/vmcore ]; then
			save_core
			reboot
		else
			start
		fi
		;;
	  stop)
		stop
		;;
	  status)
		EXIT_CODE=0
		check_current_status
		case "$?" in
		  0)
			echo "Kdump is operational"
			EXIT_CODE=0
			;;
		  1)
			echo "Kdump is not operational"
			EXIT_CODE=3
			;;
		esac
		exit $EXIT_CODE
		;;
	  restart)
		stop
		start
		;;
	  condrestart)
		;;
	  propagate)
		propagate_ssh_key
		;;
	  *)
		echo $"Usage: $0 {start|stop|status|restart|propagate}"
		exit 1
	esac
}

# Other kdumpctl instances will block in queue, until this one exits
single_instance_lock

# To avoid fd 9 leaking, we invoke a subshell, close fd 9 and call main.
# So that fd isn't leaking when main is invoking a subshell.
(exec 9<&-; main $1)

exit $?