kexec-tools/kdumpctl
Xunlei Pang 071ea2a277 kdumpctl: bail out earlier in case of no reserved memory
Some cloud people complained that VM boot speed is slower than
Ubuntu and other distributions, after some debugging, we found
that one of the causes is kdump service starts too slow(7seconds
according to the test result on the test VM), actually there is
no "crashkernel=X" specified. Although kdump service is parallel,
it affects the speed more or less especially on VMs with few cpus,
which is unacceptable. It is even worse when kdump initramfs is
built out in case of no reserved memory at first boot.

Commit afa4a35d3 ("kdumpctrl: kdump feasibility should fail if no
crash memory") can actually solve this issue.

This patch is a supplement of above-mentioned commit, we bail out
start() even earlier in case of no reserved memory.

Also made some cosmatic changes for check_crash_mem_reserved().

1) Before this patch
$ time kdumpctl start
No memory reserved for crash kernel.
Starting kdump: [FAILED]

real    0m0.282s
user    0m0.184s
sys     0m0.146s

2) After this patch
$ time kdumpctl start
No memory reserved for crash kernel
Starting kdump: [FAILED]

real    0m0.010s
user    0m0.008s
sys     0m0.001s

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Pratyush Anand <panand@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>
2017-05-02 17:23:57 +08:00

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#! /bin/sh
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
. $dracutbasedir/dracut-functions.sh
. /lib/kdump/kdump-lib.sh
standard_kexec_args="-p"
# Some default values in case /etc/sysconfig/kdump doesn't include
KDUMP_COMMANDLINE_REMOVE="hugepages hugepagesz slub_debug"
if [ -f /etc/sysconfig/kdump ]; then
. /etc/sysconfig/kdump
fi
single_instance_lock()
{
local rc timeout=5
exec 9>/var/lock/kdump
flock -n 9
rc=$?
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"
}
is_dump_to_rootfs()
{
grep "^default[[:space:]]dump_to_rootfs" /etc/kdump.conf >/dev/null
}
# 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 [ ! -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)
[ $nr -gt 1 ] && {
echo "Multiple mount targets specified in one \"dracut_args\"."
return 1
}
while read config_opt config_val; do
# remove inline comments after the end of a directive.
config_val=$(strip_comments $config_val)
case "$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)
[ -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 $TARGET_INITRD | grep "^Arguments:" | head -1)
if [[ -z "$_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()
{
is_wdt_mod_omitted
[[ $? -eq 0 ]] && return 0
[[ -d /sys/class/watchdog/ ]] || return 0
for dir in /sys/class/watchdog/*; do
[[ -d "$dir" ]] || continue
[[ -f "$dir/state" ]] || continue
wdtdrv=$(< "$dir/device/modalias")
wdtdrv=$(modinfo $wdtdrv | grep filename | awk -F"kernel/" '{print $2}')
active=$(< "$dir/state")
# rebuild when:
# module for this watchdog is not found and watchdog is active
# module for this watchdog is found and watchdog is inactive
lsinitrd $TARGET_INITRD | grep $wdtdrv &> /dev/null
if [ $? -ne 0 ]; then
[[ "$active" = "active" ]] && return 1
else
[[ "$active" = "inactive" ]] && return 1
fi
done
# check if watchdog kernel module unloaded.
loaded_mods=$(lsinitrd $TARGET_INITRD -f etc/cmdline.d/00-watchdog.conf)
[[ -n $loaded_mods ]] && loaded_mods=$(echo $loaded_mods | awk -F"rd.driver.pre=" '{print $2}' | sed "s/,/ /g")
for mod in $loaded_mods ; do
lsmod | grep $mod &> /dev/null
[[ $? != 0 ]] && return 1
done
return 0
}
# 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
if is_mode_switched; then
echo -n "Dump mode changed from last boot."; echo
handle_mode_switch
elif [ $image_time -eq 0 ]; then
echo -n "No kdump initial ramdisk found."; echo
elif [ "$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 [ $? == 0 ]; then
echo "kexec: loaded kdump kernel"
return 0
else
echo "kexec: failed to load kdump kernel" >&2
return 1
fi
}
check_ssh_config()
{
while read config_opt config_val; do
# remove inline comments after the end of a directive.
config_val=$(strip_comments $config_val)
case "$config_opt" in
sshkey)
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 '$SSH_KEY_LOCATION'"
fi
;;
path)
SAVE_PATH=$config_val
;;
ssh)
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
}
is_mode_switched()
{
local _mod_included
if [ ! -f $DEFAULT_INITRD ]; then
return 1
fi
# find if default initrd has kdumpbase module included.
_mod_included=`lsinitrd -m $DEFAULT_INITRD | grep ^kdumpbase$ | wc -l`
if [ "$DEFAULT_DUMP_MODE" != "fadump" ]; then
# If kdumpbase module is included in default initrd,
# we must have just switched from fadump mode.
if [ "$_mod_included" -eq "1" ]; then
return 0
fi
elif [ "$_mod_included" -eq "0" ]; then
# If kdumpbase module is missing in default initrd,
# we must have just switched from kdump mode.
return 0
fi
return 1
}
handle_mode_switch()
{
if [ "$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 "$coredir"
fi
return 0
}
get_save_path()
{
local _save_path=$(grep "^path" /etc/kdump.conf|awk '{print $2}')
if [ -z "$_save_path" ]; then
_save_path="/var/crash"
fi
echo $_save_path
}
is_dump_target_configured()
{
local _target
_target=$(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 $?
}
check_fence_kdump_config()
{
local hostname=`hostname`
local nodes=$(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
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 $?