kexec-tools/kdumpctl

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

KDUMP_KERNELVER=""
KDUMP_KERNEL=""
KDUMP_COMMANDLINE=""
KEXEC_ARGS=""
KDUMP_CONFIG_FILE="/etc/kdump.conf"
KDUMP_LOG_PATH="/var/log"
MKDUMPRD="/sbin/mkdumprd -f"
MKFADUMPRD="/sbin/mkfadumprd"
DRACUT_MODULES_FILE="/usr/lib/dracut/modules.txt"
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=""
KDUMP_INITRD=""
TARGET_INITRD=""
FADUMP_REGISTER_SYS_NODE="/sys/kernel/fadump_registered"
#kdump shall be the default dump mode
DEFAULT_DUMP_MODE="kdump"
image_time=0

standard_kexec_args="-d -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

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

#initiate the kdump logger
dlog_init
if [ $? -ne 0 ]; then
	echo "failed to initiate the kdump logger."
	exit 1
fi

single_instance_lock()
{
	local rc timeout=5

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

	flock -n 9
	rc=$?

	while [ $rc -ne 0 ]; do
		dinfo "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
		dinfo "Dump mode is fadump"
		DEFAULT_DUMP_MODE="fadump"
	fi
	ddebug "DEFAULT_DUMP_MODE=$DEFAULT_DUMP_MODE"
}

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

	mkdir -p $coredir
	ddebug "cp --sparse=always /proc/vmcore $coredir/vmcore-incomplete"
	cp --sparse=always /proc/vmcore $coredir/vmcore-incomplete
	if [ $? == 0 ]; then
		mv $coredir/vmcore-incomplete $coredir/vmcore
		dinfo "saved a vmcore to $coredir"
	else
		derror "failed to save a vmcore to $coredir"
	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
		ddebug "makedumpfile --dump-dmesg $coredir/vmcore $coredir/dmesg"
		makedumpfile --dump-dmesg $coredir/vmcore $coredir/dmesg >/dev/null 2>&1
		ddebug "dumpoops -d $coredir/dmesg"
		dumpoops -d $coredir/dmesg >/dev/null 2>&1
		if [ $? == 0 ]; then
			dinfo "kernel oops has been collected by abrt tool"
		fi
	fi
}

rebuild_fadump_initrd()
{
	if ! $MKFADUMPRD "$DEFAULT_INITRD_BAK" "$TARGET_INITRD" --kver "$KDUMP_KERNELVER"; then
		derror "mkfadumprd: failed to make fadump initrd"
		return 1
	fi

	return 0
}

check_earlykdump_is_enabled()
{
	grep -q -w "rd.earlykdump" /proc/cmdline
	return $?
}

rebuild_kdump_initrd()
{
	ddebug "rebuild kdump initrd: $MKDUMPRD $TARGET_INITRD $KDUMP_KERNELVER"
	$MKDUMPRD $TARGET_INITRD $KDUMP_KERNELVER
	if [ $? != 0 ]; then
		derror "mkdumprd: failed to make kdump initrd"
		return 1
	fi

	if check_earlykdump_is_enabled; then
		dwarn "Tips: If early kdump is enabled, also require rebuilding the system initramfs to make the changes take effect for early kdump."
	fi

	return 0
}

rebuild_initrd()
{
	if [[ ! -w $(dirname $TARGET_INITRD) ]];then
		derror "$(dirname $TARGET_INITRD) does not have write permission. Cannot rebuild $TARGET_INITRD"
		return 1
	fi

	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 $1; do
		if [ ! -e "$file" ]; then
			derror "Error: $file not found."
			return 1
		fi
	done
}

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

backup_default_initrd()
{
	ddebug "backup default initrd: $DEFAULT_INITRD"

	if [ ! -f "$DEFAULT_INITRD" ]; then
		return
	fi

	if [ ! -e $DEFAULT_INITRD_BAK ]; then
		dinfo "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
			dwarn "WARNING: failed to backup $DEFAULT_INITRD."
			rm -f $DEFAULT_INITRD_BAK
		fi
	fi
}

restore_default_initrd()
{
	ddebug "restore default initrd: $DEFAULT_INITRD"

	if [ ! -f "$DEFAULT_INITRD" ]; then
		return
	fi

	# 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
			dwarn "WARNING: checksum mismatch! Can't restore original initrd.."
		else
			rm -f $INITRD_CHECKSUM_LOCATION
			mv $DEFAULT_INITRD_BAK $DEFAULT_INITRD
			if [[ $? -eq 0 ]]; then
				derror "Restoring original initrd as fadump mode is disabled."
				sync
			fi
		fi
	fi
}

check_config()
{
	local -A _opt_rec
	while read -r config_opt config_val; do
		case "$config_opt" in
		dracut_args)
			if [[ $config_val == *--mount* ]]; then
				if [ $(echo $config_val | grep -o "\-\-mount" | wc -l) -ne 1 ]; then
					derror "Multiple mount targets specified in one \"dracut_args\"."
					return 1
				fi
				config_opt=_target
			fi
			;;
		raw)
			if [ -d "/proc/device-tree/ibm,opal/dump" ]; then
				dwarn "WARNING: Won't capture opalcore when 'raw' dump target is used."
			fi
			config_opt=_target
			;;
		ext[234]|minix|btrfs|xfs|nfs|ssh)
			config_opt=_target
			;;
		sshkey|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|failure_action|default|final_action|force_rebuild|force_no_rebuild|fence_kdump_args|fence_kdump_nodes)
			;;
		net|options|link_delay|disk_timeout|debug_mem_level|blacklist)
			derror "Deprecated kdump config option: $config_opt. Refer to kdump.conf manpage for alternatives."
			return 1
			;;
		'')
			continue
			;;
		*)
			derror "Invalid kdump config option $config_opt"
			return 1
			;;
		esac

		if [[ -z "$config_val" ]]; then
			derror "Invalid kdump config value for option '$config_opt'"
			return 1
		fi

		if [ -n "${_opt_rec[$config_opt]}" ]; then
			if [ $config_opt == _target ]; then
				derror "More than one dump targets specified"
			else
				derror "Duplicated kdump config value of option $config_opt"
			fi
			return 1
		fi
		_opt_rec[$config_opt]="$config_val"
	done <<< "$(read_strip_comments $KDUMP_CONFIG_FILE)"

	check_failure_action_config || return 1
	check_final_action_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
}

setup_initrd()
{
	prepare_kdump_bootinfo
	if [ $? -ne 0 ]; then
		derror "failed to prepare for kdump bootinfo."
		return 1
	fi

	DEFAULT_INITRD_BAK="$KDUMP_BOOTDIR/.$(basename $DEFAULT_INITRD).default"
	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		TARGET_INITRD="$DEFAULT_INITRD"

		# backup initrd for reference before replacing it
		# with fadump aware initrd
		backup_default_initrd
	else
		TARGET_INITRD="$KDUMP_INITRD"

		# 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
}

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 $KDUMP_CONFIG_FILE | cut -d\  -f2`
	HOOKS="/etc/kdump/post.d/ /etc/kdump/pre.d/"
	if [ -d /etc/kdump/post.d ]; then
		for file in /etc/kdump/post.d/*; do
			if [ -x "$file" ]; then
				POST_FILES="$POST_FILES $file"
			fi
		done
	fi
	if [ -d /etc/kdump/pre.d ]; then
		for file in /etc/kdump/pre.d/*; do
			if [ -x "$file" ]; then
				PRE_FILES="$PRE_FILES $file"
			fi
		done
	fi
	HOOKS="$HOOKS $POST_FILES $PRE_FILES"
	CORE_COLLECTOR=`grep ^core_collector $KDUMP_CONFIG_FILE | cut -d\  -f2`
	CORE_COLLECTOR=`type -P $CORE_COLLECTOR`
	# POST_FILES and PRE_FILES are already checked against executable, need not to check again.
	EXTRA_BINS="$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 $CORE_COLLECTOR"
	[[ -e /etc/fstab ]] && files="$files /etc/fstab"

	# Check for any updated extra module
	EXTRA_MODULES="$(grep ^extra_modules $KDUMP_CONFIG_FILE | sed 's/^extra_modules\s*//')"
	if [ -n "$EXTRA_MODULES" ]; then
		if [ -e /lib/modules/$KDUMP_KERNELVER/modules.dep ]; then
			files="$files /lib/modules/$KDUMP_KERNELVER/modules.dep"
		fi
		for _module in $EXTRA_MODULES; do
			_module_file="$(modinfo --set-version "$KDUMP_KERNELVER" --filename "$_module" 2>/dev/null)"
			if [[ $? -eq 0 ]]; then
				files="$files $_module_file"
				for _dep_modules in $(modinfo -F depends $_module | tr ',' ' '); do
				    files="$files $(modinfo --set-version "$KDUMP_KERNELVER" --filename $_dep_modules 2>/dev/null)"
				done
			else
				# If it's not a module nor builtin, give an error
				if ! ( modprobe --set-version "$KDUMP_KERNELVER" --dry-run "$_module" &>/dev/null ); then
					dwarn "Module $_module not found"
				fi
			fi
		done
	fi

	# HOOKS is mandatory and need to check the modification time
	files="$files $HOOKS"
	check_exist "$files" && check_executable "$EXTRA_BINS"
	[ $? -ne 0 ] && return 2

	for file in $files; do
		if [ -e "$file" ]; then
			time_stamp=`stat -c "%Y" $file`
			if [ "$time_stamp" -gt "$image_time" ]; then
				modified_files="$modified_files $file"
			fi
			if [ -L "$file" ]; then
				file=$(readlink -m $file)
				time_stamp=`stat -c "%Y" $file`
				if [ "$time_stamp" -gt "$image_time" ]; then
					modified_files="$modified_files $file"
				fi
			fi
		else
			dwarn "$file doesn't exist"
		fi
	done

	if [ -n "$modified_files" ]; then
		dinfo "Detected change(s) in the following file(s): $modified_files"
		return 1
	fi

	return 0
}

check_drivers_modified()
{
	local _target _new_drivers _old_drivers _module_name _module_filename

	# If it's dump target is on block device, detect the block driver
	_target=$(get_block_dump_target)
	if [[ -n "$_target" ]]; then
		_record_block_drivers() {
			local _drivers
			_drivers=$(udevadm info -a "/dev/block/$1" | sed -n 's/\s*DRIVERS=="\(\S\+\)"/\1/p')
			for _driver in $_drivers; do
				if ! [[ " $_new_drivers " == *" $_driver "* ]]; then
					_new_drivers="$_new_drivers $_driver"
				fi
			done

			ddebug "MAJ:MIN=$1 drivers='$_drivers'"
		}
		check_block_and_slaves_all _record_block_drivers "$(get_maj_min "$_target")"
	fi

	# Include watchdog drivers if watchdog module is not omitted
	is_dracut_mod_omitted watchdog || _new_drivers+=" $(get_watchdog_drvs)"

	[ -z "$_new_drivers" ] && return 0
	_old_drivers="$(lsinitrd $TARGET_INITRD -f /usr/lib/dracut/hostonly-kernel-modules.txt | tr '\n' ' ')"

	ddebug "Modules required for kdump: '$_new_drivers'"
	ddebug "Modules included in old initramfs: '$_old_drivers'"
	for _driver in $_new_drivers; do
		# Skip deprecated/invalid driver name or built-in module
		_module_name=$(modinfo --set-version "$KDUMP_KERNELVER" -F name $_driver 2>/dev/null)
		_module_filename=$(modinfo --set-version "$KDUMP_KERNELVER" -n $_driver 2>/dev/null)
		if [ $? -ne 0 ] || [ -z "$_module_name" ] || [[ "$_module_filename" = *"(builtin)"* ]]; then
			continue
		fi
		if ! [[ " $_old_drivers " == *" $_module_name "* ]]; then
			dinfo "Detected change in block device driver, new loaded module: $_module_name"
			return 1
		fi
	done
}

check_fs_modified()
{
	local _old_dev _old_mntpoint _old_fstype
	local _new_dev _new_mntpoint _new_fstype
	local _target _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=$(get_block_dump_target)
	_new_fstype=$(get_fs_type_from_target $_target)
	if [[ -z "$_target" ]] || [[ -z "$_new_fstype" ]];then
		derror "Dump target is invalid"
		return 2
	fi

	ddebug "_target=$_target _new_fstype=$_new_fstype"
	_new_dev=$(kdump_get_persistent_dev $_target)
	if [ -z "$_new_dev" ]; then
		perror "Get persistent device name failed"
		return 2
	fi

	_new_mntpoint="$(get_kdump_mntpoint_from_target $_target)"
	_dracut_args=$(lsinitrd $TARGET_INITRD -f usr/lib/dracut/build-parameter.txt)
	if [[ -z "$_dracut_args" ]];then
		dwarn "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

	dinfo "Detected change in File System"
	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_fs_modified
	ret=$?
	if [ $ret -ne 0 ]; then
		return $ret
	fi

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

	return 0
}

check_rebuild()
{
	local capture_capable_initrd="1"
	local _force_rebuild force_rebuild="0"
	local _force_no_rebuild force_no_rebuild="0"
	local ret system_modified="0"

	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
			derror "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
			derror "Error: force_rebuild value is invalid"
			return 1
		fi
	fi

	if [[ "$force_no_rebuild" == "1" && "$force_rebuild" == "1" ]]; then
		derror "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

	#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`

		#in case of fadump mode, check whether the default/target
		#initrd is already built with dump capture capability
		if [ "$DEFAULT_DUMP_MODE" == "fadump" ]; then
			capture_capable_initrd=$(lsinitrd -f $DRACUT_MODULES_FILE $TARGET_INITRD | grep -e ^kdumpbase$ -e ^zz-fadumpinit$ | wc -l)
		fi
	fi

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

	if [ $image_time -eq 0 ]; then
		dinfo "No kdump initial ramdisk found."
	elif [ "$capture_capable_initrd" == "0" ]; then
		dinfo "Rebuild $TARGET_INITRD with dump capture support"
	elif [ "$force_rebuild" != "0" ]; then
		dinfo "Force rebuild $TARGET_INITRD"
	elif [ "$system_modified" != "0" ]; then
		:
	else
		return 0
	fi

	dinfo "Rebuilding $TARGET_INITRD"
	rebuild_initrd
	return $?
}

# On ppc64le LPARs, the keys trusted by firmware do not end up in
# .builtin_trusted_keys. So instead, add the key to the .ima keyring
function load_kdump_kernel_key()
{
	# this is only called inside is_secure_boot_enforced,
	# no need to retest

        # this is only required if DT /ibm,secure-boot is a file.
        # if it is a dir, we are on OpenPower and don't need this.
        if ! [ -f /proc/device-tree/ibm,secure-boot ]; then
                return
        fi

        KDUMP_KEY_ID=$(cat /usr/share/doc/kernel-keys/$KDUMP_KERNELVER/kernel-signing-ppc.cer |
                        keyctl padd asymmetric kernelkey-$RANDOM %:.ima)
}

# remove a previously loaded key. There's no real security implication
# to leaving it around, we choose to do this because it makes it easier
# to be idempotent and so as to reduce the potential for confusion.
function remove_kdump_kernel_key()
{
	if [ -z "$KDUMP_KEY_ID" ]; then
		return
	fi

	keyctl unlink $KDUMP_KEY_ID %:.ima
}

# 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()
{
	local ret

	KEXEC_ARGS=$(prepare_kexec_args "${KEXEC_ARGS}")
	KDUMP_COMMANDLINE=$(prepare_cmdline "${KDUMP_COMMANDLINE}" "${KDUMP_COMMANDLINE_REMOVE}" "${KDUMP_COMMANDLINE_APPEND}")

	# 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
		dinfo "Secure Boot is enabled. Using kexec file based syscall."
		KEXEC_ARGS="$KEXEC_ARGS -s"
		load_kdump_kernel_key
	fi

	ddebug "$KEXEC $KEXEC_ARGS $standard_kexec_args --command-line=$KDUMP_COMMANDLINE --initrd=$TARGET_INITRD $KDUMP_KERNEL"

	# The '12' represents an intermediate temporary file descriptor
	# to store the standard error file descriptor '2', and later
	# restore the error file descriptor with the file descriptor '12'
	# and release it.
	exec 12>&2
	exec 2>> $KDUMP_LOG_PATH/kdump.log
	PS4='+ $(date "+%Y-%m-%d %H:%M:%S") ${BASH_SOURCE}@${LINENO}: '
	set -x

	$KEXEC $KEXEC_ARGS $standard_kexec_args \
		--command-line="$KDUMP_COMMANDLINE" \
		--initrd=$TARGET_INITRD $KDUMP_KERNEL

	ret=$?
	set +x
	exec 2>&12 12>&-

	remove_kdump_kernel_key

	if [ $ret == 0 ]; then
		dinfo "kexec: loaded kdump kernel"
		return 0
	else
		derror "kexec: failed to load kdump kernel"
		return 1
	fi
}

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

# ipv6 host address may takes a long time to be ready.
# Instead of checking against ipv6 address, we just check the network reachable
# by the return val of 'ssh'
check_and_wait_network_ready()
{
	local start_time=$(date +%s)
	local warn_once=1
	local cur
	local diff
	local retval
	local errmsg

	while true; do
		errmsg=$(ssh -i $SSH_KEY_LOCATION -o BatchMode=yes $DUMP_TARGET mkdir -p $SAVE_PATH 2>&1)
		retval=$?

		# ssh exits with the exit status of the remote command or with 255 if an error occurred
		if [ $retval -eq 0 ]; then
			return 0
		elif [ $retval -ne 255 ]; then
			derror "Could not create $DUMP_TARGET:$SAVE_PATH, you should check the privilege on server side"
			return 1
		fi

		# if server removes the authorized_keys or, no /root/.ssh/kdump_id_rsa
		ddebug "$errmsg"
		echo $errmsg | grep -q "Permission denied\|No such file or directory\|Host key verification failed" &> /dev/null
		if [ $? -eq 0 ]; then
			derror "Could not create $DUMP_TARGET:$SAVE_PATH, you probably need to run \"kdumpctl propagate\""
			return 1
		fi

		if [ $warn_once -eq 1 ]; then
			dwarn "Network dump target is not usable, waiting for it to be ready..."
			warn_once=0
		fi

		cur=$(date +%s)
		let "diff = $cur - $start_time"
		# 60s time out
		if [ $diff -gt 180 ]; then
			break;
		fi
		sleep 1
	done

	dinfo "Could not create $DUMP_TARGET:$SAVE_PATH, ipaddr is not ready yet. You should check network connection"
	return 1
}

check_ssh_target()
{
	check_and_wait_network_ready
	if [ $? -ne 0 ]; then
		return 1
	fi
	return 0
}

propagate_ssh_key()
{
	check_ssh_config
	if [ $? -ne 0 ]; then
		derror "No ssh config specified in $KDUMP_CONFIG_FILE.  Can't propagate"
		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
		dinfo "Using existing keys..."
	else
		dinfo "Generating new ssh keys... "
		/usr/bin/ssh-keygen -t rsa -f $KEYFILE -N "" 2>&1 > /dev/null
		dinfo "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 [ $RET == 0 ]; then
		dinfo "$KEYFILE has been added to ~$SSH_USER/.ssh/authorized_keys on $SSH_SERVER"
		return 0
	else
		derror "$errmsg, $KEYFILE failed in transfer to $SSH_SERVER"
		exit 1
	fi
}

show_reserved_mem()
{
    local mem=$(cat /sys/kernel/kexec_crash_size)
    local mem_mb=$(expr $mem / 1024 / 1024)

    dinfo "Reserved "$mem_mb"MB memory for crash kernel"
}

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_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" ] || {
		derror "raw partition $raw_target not found"
		return 1
	}
	check_fs=$(lsblk --nodeps -npo FSTYPE $raw_target)
	if [[ $(echo $check_fs | wc -w) -ne 0 ]]; then
		dwarn "Warning: Detected '$check_fs' signature on $raw_target, data loss is expected."
		return 0
	fi
	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" ] || {
		derror "failed to create $coredir"
		return 1
	}
	if makedumpfile -R $coredir/vmcore <$raw_target >/dev/null 2>&1; then
		# dump found
		dinfo "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
}

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_user_configured_dump_target; then
		if is_mount_in_dracut_args; then
		    return;
		fi

		_target=$(local_fs_dump_target)
		if [[ -n "$_target" ]]; then
			_mnt=$(get_mntpoint_from_target $_target)
			if ! is_mounted "$_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_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
			derror "Option fence_kdump_nodes cannot contain $hostname"
			return 1
		fi
		# node can be ipaddr
		echo "$ipaddrs " | grep "$node " > /dev/null
		if [ $? -eq 0 ]; then
			derror "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
		derror "fadump: failed to register"
		return 1
	fi

	dinfo "fadump: registered successfully"
	return 0
}

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

	return $?
}

check_failure_action_config()
{
	local default_option
	local failure_action
	local option="failure_action"

	default_option=$(awk '$1 ~ /^default$/ {print $2;}' $KDUMP_CONFIG_FILE)
	failure_action=$(awk '$1 ~ /^failure_action$/ {print $2;}' $KDUMP_CONFIG_FILE)

	if [ -z "$failure_action" -a -z "$default_option" ]; then
		return 0
	elif [ -n "$failure_action" -a -n "$default_option" ]; then
		derror "Cannot specify 'failure_action' and 'default' option together"
		return 1
	fi

	if [ -n "$default_option" ]; then
		option="default"
		failure_action="$default_option"
	fi

	case "$failure_action" in
	  reboot|halt|poweroff|shell|dump_to_rootfs)
		return 0
	  ;;
	  *)
		dinfo $"Usage kdump.conf: $option {reboot|halt|poweroff|shell|dump_to_rootfs}"
		return 1
	esac
}

check_final_action_config()
{
	local final_action

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

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

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

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

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

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

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

	dinfo "Starting kdump: [OK]"
}

reload()
{
	check_current_status
	if [ $? -ne 0 ]; then
		dwarn "Kdump was not running: [WARNING]"
	fi

	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
		reload_fadump
		return $?
	else
		stop_kdump
	fi

	if [ $? -ne 0 ]; then
		derror "Stopping kdump: [FAILED]"
		return 1
	fi

	dinfo "Stopping kdump: [OK]"

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

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

	dinfo "Starting kdump: [OK]"
}

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

	dinfo "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
		derror "kexec: failed to unload kdump kernel"
		return 1
	fi

	dinfo "kexec: unloaded kdump kernel"
	return 0
}

reload_fadump()
{
	echo 1 > $FADUMP_REGISTER_SYS_NODE
	if [ $? == 0 ]; then
		dinfo "fadump: re-registered successfully"
		return 0
	else
		# FADump could fail on older kernel where re-register
		# support is not enabled. Try stop/start from userspace
		# to handle such scenario.
		stop_fadump
		if [ $? == 0 ]; then
			start_fadump
			return $?
		fi
	fi

	return 1
}

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

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

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

rebuild() {
	check_config
	if [ $? -ne 0 ]; then
		return 1
	fi

	if check_ssh_config; then
		if ! check_ssh_target; then
			return 1
		fi
	fi

	setup_initrd
	if [ $? -ne 0 ]; then
		return 1
	fi

	dinfo "Rebuilding $TARGET_INITRD"
	rebuild_initrd
	return $?
}

do_estimate() {
	local kdump_mods
	local -A large_mods
	local baseline
	local kernel_size mod_size initrd_size baseline_size runtime_size reserved_size estimated_size recommanded_size
	local size_mb=$(( 1024 * 1024 ))

	setup_initrd
	if [ ! -f "$TARGET_INITRD" ]; then
		derror "kdumpctl estimate: kdump initramfs is not built yet."
		exit 1
	fi

	kdump_mods="$(lsinitrd "$TARGET_INITRD" -f /usr/lib/dracut/hostonly-kernel-modules.txt | tr '\n' ' ')"
	baseline=$(kdump_get_arch_recommend_size)
	if [[ "${baseline: -1}" == "M" ]]; then
		baseline=${baseline%M}
	elif [[ "${baseline: -1}" == "G" ]]; then
		baseline=$(( ${baseline%G} * 1024 ))
	elif [[ "${baseline: -1}" == "T" ]]; then
		baseline=$(( ${baseline%Y} * 1048576 ))
	fi

	# The default value when using crashkernel=auto
	baseline_size=$((baseline * size_mb))
	# Current reserved crashkernel size
	reserved_size=$(cat /sys/kernel/kexec_crash_size)
	# A pre-estimated value for userspace usage and kernel
	# runtime allocation, 64M should good for most cases
	runtime_size=$((64 * size_mb))
	# Kernel image size
	kernel_size=$(get_kernel_size "$KDUMP_KERNEL")
	# Kdump initramfs size
	initrd_size=$(du -b "$TARGET_INITRD" | awk '{print $1}')
	# Kernel modules static size after loaded
	mod_size=0
	while read -r _name _size _; do
		if [[ ! " $kdump_mods " == *" $_name "* ]]; then
			continue
		fi
		mod_size=$((mod_size + _size))

		# Mark module with static size larger than 2M as large module
		if [[ $((_size / size_mb)) -ge 1 ]]; then
			large_mods[$_name]=$_size
		fi
	done <<< "$(< /proc/modules)"

	# Extra memory usage required for LUKS2 decryption
	crypt_size=0
	for _dev in $(get_all_kdump_crypt_dev); do
		_crypt_info=$(cryptsetup luksDump "/dev/block/$_dev")
		[[ $(echo "$_crypt_info" | sed -n "s/^Version:\s*\(.*\)/\1/p" ) == "2" ]] || continue
		for _mem in $(echo "$_crypt_info" | sed -n "s/\sMemory:\s*\(.*\)/\1/p" | sort -n ); do
			crypt_size=$((crypt_size + _mem * 1024))
			break
		done
	done
	[[ $crypt_size -ne 0 ]] && echo -e "Encrypted kdump target requires extra memory, assuming using the keyslot with minimun memory requirement\n"

	estimated_size=$((kernel_size + mod_size + initrd_size + runtime_size + crypt_size))
	if [[ $baseline_size -gt $estimated_size ]]; then
		recommanded_size=$baseline_size
	else
		recommanded_size=$estimated_size
	fi

	echo "Reserved crashkernel:    $((reserved_size / size_mb))M"
	echo "Recommanded crashkernel: $((recommanded_size / size_mb))M"
	echo
	echo "Kernel image size:   $((kernel_size / size_mb))M"
	echo "Kernel modules size: $((mod_size / size_mb))M"
	echo "Initramfs size:      $((initrd_size / size_mb))M"
	echo "Runtime reservation: $((runtime_size / size_mb))M"
	[[ $crypt_size -ne 0 ]] && \
	echo "LUKS required size:  $((crypt_size / size_mb))M"
	echo -n "Large modules:"
	if [[ "${#large_mods[@]}" -eq 0 ]]; then
		echo " <none>"
	else
		echo ""
		for _mod in "${!large_mods[@]}"; do
			echo "    $_mod: ${large_mods[$_mod]}"
		done
	fi

	if [[ $reserved_size -le $recommanded_size ]]; then
		echo "WARNING: Current crashkernel size is lower than recommanded size $((recommanded_size / size_mb))M."
	fi
}

if [ ! -f "$KDUMP_CONFIG_FILE" ]; then
	derror "Error: No kdump config file found!"
	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)
			dinfo "Kdump is operational"
			EXIT_CODE=0
			;;
		  1)
			dinfo "Kdump is not operational"
			EXIT_CODE=3
			;;
		esac
		exit $EXIT_CODE
		;;
	  reload)
		reload
		;;
	  restart)
		stop
		start
		;;
	  rebuild)
		rebuild
		;;
	  condrestart)
		;;
	  propagate)
		propagate_ssh_key
		;;
	  showmem)
		show_reserved_mem
		;;
	  estimate)
		do_estimate
		;;
	  *)
		dinfo $"Usage: $0 {estimate|start|stop|status|restart|reload|rebuild|propagate|showmem}"
		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 $?