#!/bin/bash

#

# Kdump common variables and functions

#

. /usr/lib/kdump/kdump-lib-initramfs.sh

FENCE_KDUMP_CONFIG_FILE="/etc/sysconfig/fence_kdump"

FENCE_KDUMP_SEND="/usr/libexec/fence_kdump_send"

FADUMP_ENABLED_SYS_NODE="/sys/kernel/fadump_enabled"

is_fadump_capable()

{

    # Check if firmware-assisted dump is enabled

    # if no, fallback to kdump check

    if [[ -f $FADUMP_ENABLED_SYS_NODE ]]; then

        rc=$(<$FADUMP_ENABLED_SYS_NODE)

        [[ $rc -eq 1 ]] && return 0

    fi

    return 1

}

is_squash_available() {

    for kmodule in squashfs overlay loop; do

        if [[ -z "$KDUMP_KERNELVER" ]]; then

            modprobe --dry-run $kmodule &>/dev/null || return 1

        else

            modprobe -S $KDUMP_KERNELVER --dry-run $kmodule &>/dev/null || return 1

        fi

    done

}

perror_exit() {

    derror "$@"

    exit 1

}

# Check if fence kdump is configured in Pacemaker cluster

is_pcs_fence_kdump()

{

    # no pcs or fence_kdump_send executables installed?

    type -P pcs > /dev/null || return 1

    [[ -x $FENCE_KDUMP_SEND ]] || return 1

    # fence kdump not configured?

    (pcs cluster cib | grep 'type="fence_kdump"') &> /dev/null || return 1

}

# Check if fence_kdump is configured using kdump options

is_generic_fence_kdump()

{

    [[ -x $FENCE_KDUMP_SEND ]] || return 1

    [[ $(kdump_get_conf_val fence_kdump_nodes) ]]

}

to_dev_name() {

    local dev="${1//\"/}"

    case "$dev" in

    UUID=*)

        blkid -U "${dev#UUID=}"

        ;;

    LABEL=*)

        blkid -L "${dev#LABEL=}"

        ;;

    *)

        echo "$dev"

    esac

}

is_user_configured_dump_target()

{

    [[ $(kdump_get_conf_val "ext[234]\|xfs\|btrfs\|minix\|raw\|nfs\|ssh") ]] || is_mount_in_dracut_args

}

get_user_configured_dump_disk()

{

    local _target

    _target=$(kdump_get_conf_val "ext[234]\|xfs\|btrfs\|minix\|raw")

    [[ -n "$_target" ]] && echo $_target && return

    _target=$(get_dracut_args_target "$(kdump_get_conf_val "dracut_args")")

    [[ -b "$_target" ]] && echo $_target

}

get_block_dump_target()

{

    local _target _path

    if is_ssh_dump_target || is_nfs_dump_target; then

        return

    fi

    _target=$(get_user_configured_dump_disk)

    [[ -n "$_target" ]] && to_dev_name $_target && return

    # Get block device name from local save path

    _path=$(get_save_path)

    _target=$(get_target_from_path $_path)

    [[ -b "$_target" ]] && to_dev_name $_target

}

is_dump_to_rootfs()

{

    [[ $(kdump_get_conf_val "failure_action|default") == dump_to_rootfs ]]

}

get_failure_action_target()

{

    local _target

    if is_dump_to_rootfs; then

        # Get rootfs device name

        _target=$(get_root_fs_device)

        [[ -b "$_target" ]] && to_dev_name $_target && return

        # Then, must be nfs root

        echo "nfs"

    fi

}

# Get kdump targets(including root in case of dump_to_rootfs).

get_kdump_targets()

{

    local _target _root

    local kdump_targets

    _target=$(get_block_dump_target)

    if [[ -n "$_target" ]]; then

        kdump_targets=$_target

    elif is_ssh_dump_target; then

        kdump_targets="ssh"

    else

        kdump_targets="nfs"

    fi

    # Add the root device if dump_to_rootfs is specified.

    _root=$(get_failure_action_target)

    if [[ -n "$_root" ]] && [[ "$kdump_targets" != "$_root" ]]; then

        kdump_targets="$kdump_targets $_root"

    fi

    echo "$kdump_targets"

}

# Return the bind mount source path, return the path itself if it's not bind mounted

# Eg. if /path/to/src is bind mounted to /mnt/bind, then:

# /mnt/bind -> /path/to/src, /mnt/bind/dump -> /path/to/src/dump

#

# findmnt uses the option "-v, --nofsroot" to exclusive the [/dir]

# in the SOURCE column for bind-mounts, then if $_src equals to

# $_src_nofsroot, the mountpoint is not bind mounted directory.

#

# Below is just an example for mount info

# /dev/mapper/atomicos-root[/ostree/deploy/rhel-atomic-host/var], if the

# directory is bind mounted. The former part represents the device path, rest

# part is the bind mounted directory which quotes by bracket "[]".

get_bind_mount_source()

{

    local _mnt=$(df $1 | tail -1 | awk '{print $NF}')

    local _path=${1#$_mnt}

    local _src=$(get_mount_info SOURCE target $_mnt -f)

    local _opt=$(get_mount_info OPTIONS target $_mnt -f)

    local _fstype=$(get_mount_info FSTYPE target $_mnt -f)

    # bind mount in fstab

    if [[ -d "$_src" ]] && [[ "$_fstype" = none ]] && (echo "$_opt" | grep -q "\bbind\b"); then

        echo $_src$_path && return

    fi

    # direct mount

    local _src_nofsroot=$(get_mount_info SOURCE target $_mnt -v -f)

    if [[ $_src_nofsroot = $_src ]]; then

        echo $_mnt$_path && return

    fi

    local _fsroot=${_src#${_src_nofsroot}[}

    _fsroot=${_fsroot%]}

    _mnt=$(get_mount_info TARGET source $_src_nofsroot -f)

    # for btrfs, _fsroot will also contain the subvol value as well, strip it

    if [[ "$_fstype" = btrfs ]]; then

        local _subvol

        _subvol=${_opt#*subvol=}

        _subvol=${_subvol%,*}

        _fsroot=${_fsroot#$_subvol}

    fi

    echo $_mnt$_fsroot$_path

}

get_mntopt_from_target()

{

    get_mount_info OPTIONS source $1 -f

}

# Get the path where the target will be mounted in kdump kernel

# $1: kdump target device

get_kdump_mntpoint_from_target()

{

    local _mntpoint=$(get_mntpoint_from_target $1)

    # mount under /sysroot if dump to root disk or mount under

    # mount under /kdumproot if dump target is not mounted in first kernel

    # mount under /kdumproot/$_mntpoint in other cases in 2nd kernel.

    # systemd will be in charge to umount it.

    if [[ -z "$_mntpoint" ]];then

        _mntpoint="/kdumproot"

    else

        if [[ "$_mntpoint" = "/" ]];then

            _mntpoint="/sysroot"

        else

            _mntpoint="/kdumproot/$_mntpoint"

        fi

    fi

    # strip duplicated "/"

    echo $_mntpoint | tr -s "/"

}

kdump_get_persistent_dev() {

    local dev="${1//\"/}"

    case "$dev" in

    UUID=*)

        dev=$(blkid -U "${dev#UUID=}")

        ;;

    LABEL=*)

        dev=$(blkid -L "${dev#LABEL=}")

        ;;

    esac

    echo $(get_persistent_dev "$dev")

}

is_atomic()

{

    grep -q "ostree" /proc/cmdline

}

# get ip address or hostname from nfs/ssh config value

get_remote_host()

{

    local _config_val=$1

    # ipv6 address in kdump.conf is around with "[]",

    # factor out the ipv6 address

    _config_val=${_config_val#*@}

    _config_val=${_config_val%:/*}

    _config_val=${_config_val#[}

    _config_val=${_config_val%]}

    echo $_config_val

}

is_hostname()

{

    local _hostname=$(echo $1 | grep ":")

    if [[ -n "$_hostname" ]]; then

        return 1

    fi

    echo $1 | grep -q "[a-zA-Z]"

}

# Copied from "/etc/sysconfig/network-scripts/network-functions"

get_hwaddr()

{

    if [[ -f "/sys/class/net/${1}/address" ]]; then

        awk '{ print toupper($0) }' < /sys/class/net/${1}/address

    elif [[ -d "/sys/class/net/${1}" ]]; then

       LC_ALL= LANG= ip -o link show ${1} 2>/dev/null | \

            awk '{ print toupper(gensub(/.*link\/[^ ]* ([[:alnum:]:]*).*/,

                                        "\\1", 1)); }'

    fi

}

# Get value by a field using "nmcli -g"

# Usage: get_nmcli_value_by_field <field> <nmcli command>

#

# "nmcli --get-values" allows us to retrive value(s) by field, for example,

# nmcli --get-values <field> connection show /org/freedesktop/NetworkManager/ActiveConnection/1

# returns the following value for the corresponding field respectively,

#   Field                                  Value

#   IP4.DNS                                "10.19.42.41 | 10.11.5.19 | 10.5.30.160"

#   802-3-ethernet.s390-subchannels        ""

#   bond.options                           "mode=balance-rr"

get_nmcli_value_by_field()

{

    LANG=C nmcli --get-values "$@"

}

# Get nmcli field value of an connection apath (a D-Bus active connection path)

# Usage: get_nmcli_field_by_apath <field> <apath>

get_nmcli_field_by_conpath()

{

    local _field=$1 _apath=$2

    get_nmcli_value_by_field "$_field" connection show "$_apath"

}

# Get nmcli connection apath (a D-Bus active connection path ) by ifname

#

# apath is used for nmcli connection operations, e.g.

#  $ nmcli connection show $apath

get_nmcli_connection_apath_by_ifname()

{

    local _ifname=$1

    get_nmcli_value_by_field "GENERAL.CON-PATH" device show "$_ifname"

}

get_ifcfg_by_device()

{

    grep -E -i -l "^[[:space:]]*DEVICE=\"*${1}\"*[[:space:]]*$" \

         /etc/sysconfig/network-scripts/ifcfg-* 2>/dev/null | head -1

}

get_ifcfg_by_hwaddr()

{

    grep -E -i -l "^[[:space:]]*HWADDR=\"*${1}\"*[[:space:]]*$" \

         /etc/sysconfig/network-scripts/ifcfg-* 2>/dev/null | head -1

}

get_ifcfg_by_uuid()

{

    grep -E -i -l "^[[:space:]]*UUID=\"*${1}\"*[[:space:]]*$" \

         /etc/sysconfig/network-scripts/ifcfg-* 2>/dev/null | head -1

}

get_ifcfg_by_name()

{

    grep -E -i -l "^[[:space:]]*NAME=\"*${1}\"*[[:space:]]*$" \

         /etc/sysconfig/network-scripts/ifcfg-* 2>/dev/null | head -1

}

is_nm_running()

{

    [[ "$(LANG=C nmcli -t --fields running general status 2>/dev/null)" = "running" ]]

}

is_nm_handling()

{

    LANG=C nmcli -t --fields device,state  dev status 2>/dev/null \

          | grep -q "^\(${1}:connected\)\|\(${1}:connecting.*\)$"

}

# $1: netdev name

get_ifcfg_nmcli()

{

    local nm_uuid nm_name

    local ifcfg_file

    # Get the active nmcli config name of $1

    if is_nm_running && is_nm_handling "${1}" ; then

        # The configuration "uuid" and "name" generated by nm is wrote to

        # the ifcfg file as "UUID=<nm_uuid>" and "NAME=<nm_name>".

        nm_uuid=$(LANG=C nmcli -t --fields uuid,device c show --active 2>/dev/null \

                  | grep "${1}" | head -1 | cut -d':' -f1)

        nm_name=$(LANG=C nmcli -t --fields name,device c show --active 2>/dev/null \

                  | grep "${1}" | head -1 | cut -d':' -f1)

        ifcfg_file=$(get_ifcfg_by_uuid "${nm_uuid}")

        [[ -z "${ifcfg_file}" ]] && ifcfg_file=$(get_ifcfg_by_name "${nm_name}")

    fi

    echo -n "${ifcfg_file}"

}

# $1: netdev name

get_ifcfg_legacy()

{

    local ifcfg_file

    ifcfg_file="/etc/sysconfig/network-scripts/ifcfg-${1}"

    [[ -f "${ifcfg_file}" ]] && echo -n "${ifcfg_file}" && return

    ifcfg_file=$(get_ifcfg_by_name "${1}")

    [[ -f "${ifcfg_file}" ]] && echo -n "${ifcfg_file}" && return

    local hwaddr=$(get_hwaddr "${1}")

    if [[ -n "$hwaddr" ]]; then

        ifcfg_file=$(get_ifcfg_by_hwaddr "${hwaddr}")

        [[ -f "${ifcfg_file}" ]] && echo -n "${ifcfg_file}" && return

    fi

    ifcfg_file=$(get_ifcfg_by_device "${1}")

    echo -n "${ifcfg_file}"

}

# $1: netdev name

# Return the ifcfg file whole name(including the path) of $1 if any.

get_ifcfg_filename() {

    local ifcfg_file

    ifcfg_file=$(get_ifcfg_nmcli "${1}")

    if [[ -z "${ifcfg_file}" ]]; then

        ifcfg_file=$(get_ifcfg_legacy "${1}")

    fi

    echo -n "${ifcfg_file}"

}

# returns 0 when omission of a module is desired in dracut_args

# returns 1 otherwise

is_dracut_mod_omitted() {

    local dracut_args dracut_mod=$1

    set -- $(kdump_get_conf_val dracut_args)

    while [ $# -gt 0 ]; do

        case $1 in

            -o|--omit)

                [[ " ${2//[^[:alnum:]]/ } " ==  *" $dracut_mod "* ]] && return 0

        esac

        shift

    done

    return 1

}

is_wdt_active() {

    local active

    [[ -d /sys/class/watchdog ]] || return 1

    for dir in /sys/class/watchdog/*; do

        [[ -f "$dir/state" ]] || continue

        active=$(< "$dir/state")

        [[ "$active" =  "active" ]] && return 0

    done

    return 1

}

# If "dracut_args" contains "--mount" information, use it

# directly without any check(users are expected to ensure

# its correctness).

is_mount_in_dracut_args()

{

    [[ " $(kdump_get_conf_val dracut_args)" =~ .*[[:space:]]--mount[=[:space:]].* ]]

}

check_crash_mem_reserved()

{

    local mem_reserved

    mem_reserved=$(

    if [[ $mem_reserved -eq 0 ]]; then

        derror "No memory reserved for crash kernel"

        return 1

    fi

    return 0

}

check_kdump_feasibility()

{

    if [[ ! -e /sys/kernel/kexec_crash_loaded ]]; then

        derror "Kdump is not supported on this kernel"

        return 1

    fi

    check_crash_mem_reserved

    return $?

}

check_current_kdump_status()

{

    if [[ ! -f /sys/kernel/kexec_crash_loaded ]];then

        derror "Perhaps CONFIG_CRASH_DUMP is not enabled in kernel"

        return 1

    fi

    rc=$(

    if [[ $rc == 1 ]]; then

        return 0

    else

        return 1

    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 "apicid" of the boot

# cpu (cpu 0) if present.

#

get_bootcpu_apicid()

{

    awk '                                                       \

        BEGIN { CPU = "-1"; }                                   \

        $1=="processor" && $2==":"      { CPU = $NF; }          \

        CPU=="0" && /^apicid/           { print $NF; }          \

        '                                                       \

        /proc/cpuinfo

}

#

# append_cmdline <kernel cmdline> <parameter name> <parameter value>

# 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

}

# 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")); }')"

}

# 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

    # On powerpc, os-secureboot-enforcing DT property indicates whether secureboot

    # is enforced. Return success, if it is found.

    if [[ -f /proc/device-tree/ibm,secureboot/os-secureboot-enforcing ]]; then

		return 0

    fi

    # Detect secure boot on x86 and arm64

    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

    # Detect secure boot on s390x

    if [[ -e "/sys/firmware/ipl/secure" && "$(

        return 0

    fi

    return 1

}

#

# prepare_kexec_args <kexec args>

# This function prepares kexec argument.

#

prepare_kexec_args()

{

    local kexec_args=$1

    local found_elf_args

    ARCH=$(uname -m)

    if [[ "$ARCH" == "i686" ]] || [[ "$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

                dwarn "Warning: elf32-core-headers overrides correct elf64 setting"

            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

    echo $kexec_args

}

#

# Detect initrd and kernel location, results are stored in global enviromental variables:

# KDUMP_BOOTDIR, KDUMP_KERNELVER, KDUMP_KERNEL, DEFAULT_INITRD, and KDUMP_INITRD

#

# Expectes KDUMP_BOOTDIR, KDUMP_IMG, KDUMP_IMG_EXT, KDUMP_KERNELVER to be loaded from config already

# and will prefer already set values so user can specify custom kernel/initramfs location

#

prepare_kdump_bootinfo()

{

    local boot_imglist boot_dirlist boot_initrdlist

    local machine_id

    if [[ -z "$KDUMP_KERNELVER" ]]; then

        KDUMP_KERNELVER="$(uname -r)"

    fi

    read -r machine_id < /etc/machine-id

    boot_dirlist=${KDUMP_BOOTDIR:-"/boot /boot/efi /efi /"}

    boot_imglist="$KDUMP_IMG-$KDUMP_KERNELVER$KDUMP_IMG_EXT $machine_id/$KDUMP_KERNELVER/$KDUMP_IMG"

    # Use BOOT_IMAGE as reference if possible, strip the GRUB root device prefix in (hd0,gpt1) format

    local boot_img="$(sed "s/^BOOT_IMAGE=\((\S*)\)\?\(\S*\) .*/\2/" /proc/cmdline)"

    if [[ -n "$boot_img" ]]; then

        boot_imglist="$boot_img $boot_imglist"

    fi

    for dir in $boot_dirlist; do

        for img in $boot_imglist; do

            if [[ -f "$dir/$img" ]]; then

                KDUMP_KERNEL=$(echo $dir/$img | tr -s '/')

                break 2

            fi

        done

    done

    if ! [[ -e "$KDUMP_KERNEL" ]]; then

        derror "Failed to detect kdump kernel location"

        return 1

    fi

    # Set KDUMP_BOOTDIR to where kernel image is stored

    KDUMP_BOOTDIR=$(dirname $KDUMP_KERNEL)

    # Default initrd should just stay aside of kernel image, try to find it in KDUMP_BOOTDIR

    boot_initrdlist="initramfs-$KDUMP_KERNELVER.img initrd"

    for initrd in $boot_initrdlist; do

        if [[ -f "$KDUMP_BOOTDIR/$initrd" ]]; then

            defaut_initrd_base="$initrd"

            DEFAULT_INITRD="$KDUMP_BOOTDIR/$defaut_initrd_base"

            break

        fi

    done

    # Create kdump initrd basename from default initrd basename

    # initramfs-5.7.9-200.fc32.x86_64.img => initramfs-5.7.9-200.fc32.x86_64kdump.img

    # initrd => initrdkdump

    if [[ -z "$defaut_initrd_base" ]]; then

        kdump_initrd_base=initramfs-${KDUMP_KERNELVER}kdump.img

    elif [[ $defaut_initrd_base == *.* ]]; then

        kdump_initrd_base=${defaut_initrd_base%.*}kdump.${DEFAULT_INITRD##*.}

    else

        kdump_initrd_base=${defaut_initrd_base}kdump

    fi

    # Place kdump initrd in $(/var/lib/kdump) if $(KDUMP_BOOTDIR) not writable

    if [[ ! -w "$KDUMP_BOOTDIR" ]];then

        var_target_initrd_dir="/var/lib/kdump"

        mkdir -p "$var_target_initrd_dir"

        KDUMP_INITRD="$var_target_initrd_dir/$kdump_initrd_base"

    else

        KDUMP_INITRD="$KDUMP_BOOTDIR/$kdump_initrd_base"

    fi

}

get_watchdog_drvs()

{

    local _wdtdrvs _drv _dir

    for _dir in /sys/class/watchdog/*; do

        # device/modalias will return driver of this device

        [[ -f "$_dir/device/modalias" ]] || continue

        _drv=$(< "$_dir/device/modalias")

        _drv=$(modprobe --set-version "$KDUMP_KERNELVER" -R $_drv 2>/dev/null)

        for i in $_drv; do

            if ! [[ " $_wdtdrvs " == *" $i "* ]]; then

                _wdtdrvs="$_wdtdrvs $i"

            fi

        done

    done

    echo $_wdtdrvs

}

#

# prepare_cmdline <commandline> <commandline remove> <commandline append>

# 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 "$1" ]]; then

        cmdline=$(

    else

        cmdline="$1"

    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" "$2")

    # Always remove "root=X", as we now explicitly generate all kinds

    # of dump target mount information including root fs.

    #

    # 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.

    cmdline=$(remove_cmdline_param "$cmdline" root)

    # With the help of "--hostonly-cmdline", we can avoid some interitage.

    cmdline=$(remove_cmdline_param "$cmdline" rd.lvm.lv rd.luks.uuid rd.dm.uuid rd.md.uuid fcoe)

    # Remove netroot, rd.iscsi.initiator and iscsi_initiator since

    # we get duplicate entries for the same in case iscsi code adds

    # it as well.

    cmdline=$(remove_cmdline_param "$cmdline" netroot rd.iscsi.initiator iscsi_initiator)

    cmdline="${cmdline} $3"

    id=$(get_bootcpu_apicid)

    if [[ -n ${id} ]] ; then

        cmdline=$(append_cmdline "$cmdline" disable_cpu_apicid "$id")

    fi

    # If any watchdog is used, set it's pretimeout to 0. pretimeout let

    # watchdog panic the kernel first, and reset the system after the

    # panic. If the system is already in kdump, panic is not helpful

    # and only increase the chance of watchdog failure.

    for i in $(get_watchdog_drvs); do

        cmdline+=" $i.pretimeout=0"

        if [[ $i == hpwdt ]]; then

            # hpwdt have a special parameter kdumptimeout, is's only suppose

            # to be set to non-zero in first kernel. In kdump, non-zero

            # value could prevent the watchdog from resetting the system.

            cmdline+=" $i.kdumptimeout=0"

        fi

    done

    # Remove trace_buf_size, trace_event

    cmdline=$(remove_cmdline_param "$cmdline" trace_buf_size trace_event)

    cmdline="${cmdline} trace_buf_size=1"

    echo ${cmdline}

}

#get system memory size in the unit of GB

get_system_size()

{

    result=$(grep "System RAM" /proc/iomem | awk -F ":" '{ print $1 }' | tr [:lower:] [:upper:] | paste -sd+)

    result="+$result"

    # replace '-' with '+0x' and '+' with '-0x'

    sum=$(echo "$result" | sed -e 's/-/K0x/g' -e 's/+/-0x/g' -e 's/K/+/g')

    size=$(printf "%d\n" $(($sum)))

    size=$((size / 1024 / 1024 / 1024))

    echo $size

}

get_recommend_size()

{

    local mem_size=$1

    local _ck_cmdline=$2

    local OLDIFS="$IFS"

    start=${_ck_cmdline: :1}

    if [[ $mem_size -lt $start ]]; then

        echo "0M"

        return

    fi

    IFS=','

    for i in $_ck_cmdline; do

        end=$(echo $i | awk -F "-" '{ print $2 }' | awk -F ":" '{ print $1 }')

        recommend=$(echo $i | awk -F "-" '{ print $2 }' | awk -F ":" '{ print $2 }')

        size=${end: : -1}

        unit=${end: -1}

        if [[ $unit == 'T' ]]; then

            size=$((size * 1024))

        fi

        if [[ $mem_size -lt $size ]]; then

            echo $recommend

            IFS="$OLDIFS"

            return

        fi

    done

    IFS="$OLDIFS"

}

# return recommended size based on current system RAM size

# $1: kernel version, if not set, will defaults to $(uname -r)

kdump_get_arch_recommend_size()

{

    local kernel=$1 arch

    if ! [[ -r "/proc/iomem" ]] ; then

        echo "Error, can not access /proc/iomem."

        return 1

    fi

    [[ -z "$kernel" ]] && kernel=$(uname -r)

    ck_cmdline=$(cat "/usr/lib/modules/$kernel/crashkernel.default" 2>/dev/null)

    if [[ -n "$ck_cmdline" ]]; then

        ck_cmdline=${ck_cmdline#crashkernel=}

    else

        arch=$(lscpu | grep Architecture | awk -F ":" '{ print $2 }' | tr '[:lower:]' '[:upper:]')

        if [[ "$arch" = "X86_64" ]] || [[ "$arch" = "S390X" ]]; then

            ck_cmdline="1G-4G:160M,4G-64G:192M,64G-1T:256M,1T-:512M"

        elif [[ "$arch" = "AARCH64" ]]; then

            ck_cmdline="2G-:448M"

        elif [[ "$arch" = "PPC64LE" ]]; then

            if is_fadump_capable; then

                ck_cmdline="4G-16G:768M,16G-64G:1G,64G-128G:2G,128G-1T:4G,1T-2T:6G,2T-4T:12G,4T-8T:20G,8T-16T:36G,16T-32T:64G,32T-64T:128G,64T-:180G"

            else

                ck_cmdline="2G-4G:384M,4G-16G:512M,16G-64G:1G,64G-128G:2G,128G-:4G"

            fi

        fi

    fi

    ck_cmdline=${ck_cmdline//-:/-102400T:}

    sys_mem=$(get_system_size)

    get_recommend_size "$sys_mem" "$ck_cmdline"

}

# Print all underlying crypt devices of a block device

# print nothing if device is not on top of a crypt device

# $1: the block device to be checked in maj:min format

get_luks_crypt_dev()

{

    [[ -b /dev/block/$1 ]] || return 1