kdump-tools 1:1.5.3-2 / usr / sbin / kdump-config

#!/bin/bash

# kdump-config
# Copyright (C) 2007-2009 Hewlett-Packard Development Company, L.P.
# Written by Terry Loftin <terry.loftin@hp.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

# kdump-config
# 	a shell script utility to manage:
#	* loading a kdump kernel
#	* unloading a kdump kernel
#	* saving a vmcore kdump kernel
#	* determining the status of kdump

PATH=/bin:/usr/bin:/sbin:/usr/sbin
NAME=${NAME:="kdump-config"}

. /lib/lsb/init-functions
. /lib/init/vars.sh

# Global Setup
KDUMP_DEFAULTS=/etc/default/kdump-tools
[ -r $KDUMP_DEFAULTS ] && . $KDUMP_DEFAULTS

KEXEC=/sbin/kexec
[ -e $KEXEC ] || exit 1;

KVER=`uname -r`
ARCH=`uname -m`

# Set up defaults
KDUMP_SYSCTL=${KDUMP_SYSCTL:="kernel.panic_on_oops=1"}
KDUMP_COREDIR=${KDUMP_COREDIR:=/var/crash}
KDUMP_CMDLINE_APPEND=${KDUMP_CMDLINE_APPEND:="irqpoll maxcpus=1 nousb systemd.unit=kdump-tools.service"}
[ -d $KDUMP_COREDIR ] || mkdir -p $KDUMP_COREDIR ;

IOMEM_ADDR=`grep -i "Crash kernel" /proc/iomem | sed "s/-..*//" | sed "s/^[ 0]*/0x/"`

# Constants
vmcore_file=/proc/vmcore
sys_kexec_crash=/sys/kernel/kexec_crash_loaded
kernel_link=$KDUMP_COREDIR/kernel_link
systemmap_link=$KDUMP_COREDIR/system.map_link
kconfig_link=$KDUMP_COREDIR/config_link
kexec_cmd_file=$KDUMP_COREDIR/kexec_cmd

# Utility Functions
#
function kdump_help()
{
cat <<EOHELP
Usage:
kdump-config {help|test|show|status|load|unload|savecore}"
  help     - print this page
  test     - Do a dry-run of the load command.  Show the kernels and
             parameters that will be used and echo the kexec command.
             The kexec command will not be executed.
  show     - Show kdump status, kexec command, and any current parameters.
  status   - evaluate /sys/kernel/kexec_crash_loaded and print a message
  load     - Locate the kdump kernel, debug kernel, and establish links for
             makedumpfile.  Then load the kdump kernel using kexec
  unload   - unload the kdump kernel using kexec
  savecore - use previously made links to save /proc/vmcore

EOHELP
}

function kdump_show()
{
	echo "USE_KDUMP:        $USE_KDUMP"
	echo "KDUMP_SYSCTL:     $KDUMP_SYSCTL"
	echo "KDUMP_COREDIR:    $KDUMP_COREDIR"
	echo "crashkernel addr: $IOMEM_ADDR"
	if [ -e $sys_kexec_crash -a `cat $sys_kexec_crash` -eq 1 ] ; then
		echo "current state:    ready to kdump";
	else
		echo "current state:    Not ready to kdump";
	fi
	echo
	echo "kernel link: "
	echo "  "`readlink -n -s $kernel_link`
	echo
	echo "kexec command:"
	echo -n "  "
	if [ -e $kexec_cmd_file ] ; then
		cat $kexec_cmd_file ;
	else
		echo "no kexec command recorded"
	fi
}

function kdump_test()
{
	echo "USE_KDUMP:         $USE_KDUMP"
	echo "KDUMP_SYSCTL:      $KDUMP_SYSCTL"
	echo "KDUMP_COREDIR:     $KDUMP_COREDIR"
	echo "crashkernel addr:  $IOMEM_ADDR"
	echo "kdump kernel addr: $KDUMP_ADDR"
	echo "kdump kernel:"
	echo "   $KDUMP_KERNEL"
	echo "kdump initrd: "
	echo "  $KDUMP_INITRD"
	echo "debug kernel: "
	echo "  $DEBUG_KERNEL"
	echo "kexec command to be used:"
	echo "  $KEXEC_CMD"
}

# check_kdump_support:  Other miscellaneous checks go here:
# 1: if USE_KDUMP is 0, don't set up kdump.
# 2: -e /sys/kernel/kexec_crash loaded indicates that this kernel
#    thinks it supports kdump
# 3: the current kernel should have booted with a crashkernel= command
#    line parameter.
#
# Returns: none. prints warnings or exit
function check_kdump_support()
{
	if [ -z "$USE_KDUMP" -o "$USE_KDUMP" == "0" ] ; then
		log_failure_msg "$KDUMP_DEFAULTS: USE_KDUMP is not set or zero"
		[ ! $DRY_RUN ] && exit 1;
	fi
	if [ ! -e $sys_kexec_crash ] ; then
		log_failure_msg "kdump is not supported by this kernel"
		[ ! $DRY_RUN ] && exit 1;
	fi
	CRASHKERNEL=`grep -i crashkernel= /proc/cmdline`;
	if [ -z "$CRASHKERNEL" ] ; then
		log_failure_msg "no crashkernel= parameter in the kernel cmdline"
		[ ! $DRY_RUN ] && exit 1;
	fi
}

# check_relocatable: check if the given kernel config is relocatable
# Arguments:
#   1: the config file to check
# Returns: 0 if the given kernel config indicates a relocatable kernel.
#          1 otherwise.
function check_relocatable()
{
	if [ $ARCH = "ia64" ]; then
		# Linux is always relocatable on ia64
		return 0
	elif grep -q 'CONFIG_RELOCATABLE=y' $1; then
		return 0
	else
		return 1
	fi
}

# We need to find debug kernel for makedumpfile file to use when 
# processing the vmcore file.  This will 
#   A) speed up the vmcore copy and 
#   B) make it much smaller (see A).
# When the kdump kernel boots, we have no idea what kernel just 
# dumped, so we should determine this info whenever a normal (non-kdump) 
# kernel boots.
#
# Use the following priorites in determining the debug kernel:
#	 1. An explicit Debug kernel in the defaults file overrides all
#	 2. Look for an installed debug kernel matching the current `uname -r`
# 	 3. Give up.  Note, that a debug kernel is optional.
#
# Returns: 0/1 (success/fail)
# Sets:    MAKEDUMP_CONFIG, DEBUG_KERNEL, DEBUG_CONFIG, DEBUG_MAP
function locate_debug_kernel()
{
	MAKEDUMP_CONFIG=$KDUMP_COREDIR/makedump-config-$KVER

	# 1: Is there an Explicit DEBUG_KERNEL in the defaults file?
	if [ -n "$DEBUG_KERNEL" ] ; then
		if [ ! -e "$DEBUG_KERNEL" ] ; then
			log_failure_msg "$KDUMP_DEFAULTS: DEBUG_KERNEL " \
				"does not exist: $DEBUG_KERNEL"
			logger -t $NAME "$KDUMP_DEFAULTS: DEBUG_KERNEL " \
				"does not exist: $DEBUG_KERNEL"
			return 1;
		fi

	# 2: Look for an installed debug kernel
	elif [ -e /usr/lib/debug/boot/vmlinux-$KVER ] ; then
		DEBUG_KERNEL=/usr/lib/debug/boot/vmlinux-$KVER
		DEBUG_CONFIG=/boot/config-$KVER
		DEBUG_MAP=/boot/System.map-$KVER
	elif [ -e /usr/lib/debug/vmlinux-$KVER ] ; then
		DEBUG_KERNEL=/usr/lib/debug/vmlinux-$KVER
		DEBUG_CONFIG=/usr/lib/debug/config-$KVER
		DEBUG_MAP=/usr/lib/debug/System.map-$KVER

	# FIXME: Look for a vmcoreinfo file

	# 3: give up :)
	else
		echo "Could not find an installed debug vmlinux image and"
		echo "DEBUG_KERNEL is not specified in $KDUMP_DEFAULTS"
		log_warning_msg "makedumpfile may be limited to -d 1"
		return 1;
	fi

	if [ $DRY_RUN ] ; then return 0; fi

	# Okay, now we know the name of the debug kernel and it exists...
	if [ -e "$DEBUG_KERNEL" ] ; then

		rm -f $kernel_link $systemmap_link $kconfig_link
		# Create Links to the stuff to preserve what we found.
		# The kdump kernel won't be able to determine this on its own.
		[ -e "$DEBUG_KERNEL" ] && ln -s $DEBUG_KERNEL $kernel_link
		[ -e "$DEBUG_MAP" ]    && ln -s $DEBUG_MAP    $systemmap_link
		[ -e "$DEBUG_CONFIG" ] && ln -s $DEBUG_CONFIG $kconfig_link

		return 0;
	fi

	# This can't actually be reached...
	log_failure_msg "Warning: no debug kernel found"
	return 1;
}

# Find the kexec/kdump kernel and possibly a corresponding initrd.
# A kdump kernel does not need to match the `uname -r` of the booted kernel.
#
# Use the following priorites in determining the kdump kernel:
#	 1. An explicit Kdump kernel in the defaults file overrides all
#    2. Use the current running kernel if it is relocatable.
#	 3. Give up.  Note, a kdump kernel is required.
#
# Returns: 0/1 (success/fail)
# Returns: none. prints warnings or exit
# Sets:    KDUMP_KERNEL, KDUMP_INITRD
function locate_kdump_kernel()
{
	# 1:  User may have specified the KDUMP_KERNEL and KDUMP_INITRD 
	#     explicitly.   Test for existance and either use it or fail.
	if [ -n "$KDUMP_KERNEL" ] ; then
		if [ ! -e "$KDUMP_KERNEL" ] ; then
			log_failure_msg "$KDUMP_DEFAULTS: KDUMP_KERNEL does not exist: $KDUMP_KERNEL"
			[ ! $DRY_RUN ] && exit 1;
		elif [ -n "$KDUMP_INITRD" -a ! -e "$KDUMP_INITRD" ] ; then
			log_failure_msg "$KDUMP_DEFAULTS: KDUMP_INITRD does not exist: $KDUMP_INITRD"
			[ ! $DRY_RUN ] && exit 1;
		fi
		return 0;
	fi

	# 2: The currently running kernel may be relocatable.  If so, then
	#    use the currently running kernel as the crash kernel.
	if check_relocatable /boot/config-$KVER; then
		KDUMP_KERNEL=/boot/vmlinuz-$KVER
		if [ -f /boot/initrd.img-$KVER ]; then
			KDUMP_INITRD=/boot/initrd.img-$KVER
		else
			KDUMP_INITRD=
		fi
		KDUMP_ADDR="relocatable"
		return 0;
	fi

	# If the kdump kernel is not relocatable, we need to make sure it was
	# built to start at the crashkernel= address.  IOMEM_ADDR is already
	# set...
	if [ -z "$KDUMP_CONFIG" ] ; then return 0 ; fi

	if check_relocatable $KDUMP_CONFIG; then
		KDUMP_ADDR="relocatable"
	else
		KDUMP_ADDR=`grep CONFIG_PHYSICAL_START $KDUMP_CONFIG | sed "s/CONFIG_PHYSICAL_START=//"`
		# compare the two
		if [ $KDUMP_ADDR != $IOMEM_ADDR ] ; then
			log_failure_msg "kdump kernel relocation address does not match crashkernel parameter"
	        [ ! $DRY_RUN ] && exit 1;
			return 1;
		fi
	fi

	return 0;
}


#
# Load the already determined kdump kernel and kdump initrd using kexec
# 	1: A KDUMP_CMDLINE in the defaults file overrides all.
#	2: Use /proc/cmdline
#			a. strip out the crashkernel= parameter.
#			b. strip out the abm= parameter.
#			c. append KDUMP_CMDLINE_APPEND from defaults file
# Sets:    KEXEC_CMD
# Returns: none. prints warnings or exit
function kdump_load()
{
	# assemble the kexec command used to load the kdump kernel
	KEXEC_CMD="$KEXEC -p"

	# Different kernel types allow/require different options:
	# The only special case here is that x86, x86_64 elf style
	# binaries require the --args-linux argument.
	if [ $ARCH != "ia64" ] ; then
		ELF_TST=`file $KDUMP_KERNEL | grep ELF`
		if [ -n "$ELF_TST" ] ; then
			KEXEC_CMD="$KEXEC_CMD --args-linux"
		fi
	fi
		
	# KDUMP_KEXEC_ARGS, if non-empty, comes from the defaults file.
	if [ -n "$KDUMP_KEXEC_ARGS" ] ; then
		KEXEC_CMD="$KEXEC_CMD $KDUMP_KEXEC_ARGS"
	fi

	# Assemble the --commmand-line:
	if [ -z "$KDUMP_CMDLINE" ] ; then
		KDUMP_CMDLINE=`cat /proc/cmdline | \
		sed -r -e 's/(^| )crashkernel=[^ ]*//g' \
		       -e 's/(^| )abm=[^ ]*//g'`
	fi
	KDUMP_CMDLINE="$KDUMP_CMDLINE $KDUMP_CMDLINE_APPEND"
	KEXEC_CMD="$KEXEC_CMD --command-line=\"$KDUMP_CMDLINE\""

	# Assemble the --initrd:
	if [ -e "$KDUMP_INITRD" ] ; then
		KEXEC_CMD="$KEXEC_CMD --initrd=$KDUMP_INITRD"
	fi

	# Finally, add the kernel:
	KEXEC_CMD="$KEXEC_CMD $KDUMP_KERNEL"

	if [ $DRY_RUN ] ; then return 0; fi

	eval $KEXEC_CMD

	if [ $? == 0 ]; then
		log_success_msg "loaded kdump kernel"
		logger -t $NAME "$KEXEC_CMD"
		logger -t $NAME "loaded kdump kernel"
		echo "$KEXEC_CMD" >$kexec_cmd_file
	else
		log_failure_msg "failed to load kdump kernel"
		logger -t $NAME "failed to load kdump kernel"
		[ ! $DRY_RUN ] && exit 1;
	fi

	# Last step: make sure panic_on_oops is enabled
	if [ -x /sbin/sysctl -a "$KDUMP_SYSCTL" != " " ] ; then
		sysctl -w $KDUMP_SYSCTL >/dev/null
	fi
}

# Returns: none. prints warnings or exit
function kdump_unload()
{
	$KEXEC -p -u
	if [ $? == 0 ]; then
		log_success_msg "unloaded kdump kernel"
		logger -t $NAME "unloaded kdump kernel"
	else
		log_failure_msg "failed to unload kdump kernel"
		logger -t $NAME "failed to unload kdump kernel"
		[ ! $DRY_RUN ] && exit 1;
	fi
}

# Saving the vmcore:
#	Our priorities are:
#	  1. If the makedumpfile config link is valid, use that
#	  2. else if the vmlinux link is valid, use that
#	  3. else fallback to using:  makedumpfile -d 1 -c
#	  4. else use cp
#
# TODO: implement different transport options other than
# store to local disk
#
# Returns: 0/1 (success/fail)
# Sets: KDUMP_STAMPDIR, KDUMP_COREFILE
function kdump_save_core()
{
	KDUMP_STAMPDIR="$KDUMP_COREDIR/"`date +"%Y%m%d%H%M"`
	KDUMP_CORETEMP="$KDUMP_STAMPDIR/dump-incomplete"
	KDUMP_COREFILE="$KDUMP_STAMPDIR/dump."`date +"%Y%m%d%H%M"`
	KDUMP_DMESGFILE="$KDUMP_STAMPDIR/dmesg."`date +"%Y%m%d%H%M"`

	mkdir -p $KDUMP_STAMPDIR

	DEBUG_KERNEL=`readlink -n -s $kernel_link`
	if [ -e "$DEBUG_KERNEL" ] ; then
		MAKEDUMP_ARGS=${MAKEDUMP_ARGS:="-c -d 31"}
		MAKEDUMP_ARGS="$MAKEDUMP_ARGS -x $DEBUG_KERNEL"
	else
		MAKEDUMP_ARGS=${MAKEDUMP_ARGS:="-c -d 1"}
	fi

	# Move previously linked kernel particulars into dump directory.
	[ -e $kernel_link ] && mv $kernel_link $KDUMP_STAMPDIR
	[ -e $kconfig_link ] && mv $kconfig_link $KDUMP_STAMPDIR
	[ -e $systemmap_link ] && mv $systemmap_link $KDUMP_STAMPDIR

	log_action_msg "running makedumpfile $MAKEDUMP_ARGS $vmcore_file $KDUMP_CORETEMP"
	makedumpfile $MAKEDUMP_ARGS $vmcore_file $KDUMP_CORETEMP
	if [ $? -ne 0 ] ; then
		log_failure_msg "$NAME: makedumpfile failed, falling back to 'cp'"
		logger -t $NAME "makedumpfile failed, falling back to 'cp'"
		KDUMP_CORETEMP="$KDUMP_STAMPDIR/vmcore-incomplete"
		KDUMP_COREFILE="$KDUMP_STAMPDIR/vmcore."`date +"%Y%m%d%H%M"`
		cp $vmcore_file $KDUMP_CORETEMP
	fi

	# did we succeed?
	if [ $? == 0 ]; then
		mv $KDUMP_CORETEMP $KDUMP_COREFILE
		log_success_msg "$NAME: saved vmcore in $KDUMP_STAMPDIR"
		logger -t $NAME "saved vmcore in $KDUMP_STAMPDIR"
		sync
	else
		log_failure_msg "$NAME: failed to save vmcore in $KDUMP_STAMPDIR"
		logger -t $NAME "failed to save vmcore in $KDUMP_STAMPDIR"
	fi

	log_action_msg "running makedumpfile --dump-dmesg $vmcore_file $KDUMP_DMESGFILE"
	makedumpfile --dump-dmesg $vmcore_file $KDUMP_DMESGFILE
	ERROR=$?
	if [ $ERROR -ne 0 ] ; then
		log_failure_msg "$NAME: makedumpfile --dump-dmesg failed. dmesg content will be unavailable"
		logger -t $NAME "makedumpfile --dump-dmesg failed. dmesg content will be unavailable"
	fi

	# did we succeed?
	if [ $ERROR == 0 ]; then
		log_success_msg "$NAME: saved dmesg content in $KDUMP_STAMPDIR"
		logger -t $NAME "saved dmesg content in $KDUMP_STAMPDIR"
		sync
		return 0;
	else
		log_failure_msg "$NAME: failed to save dmesg content in $KDUMP_STAMPDIR"
		logger -t $NAME "failed to save dmesg content in $KDUMP_STAMPDIR"
		return 1;
	fi
}



case "$1" in
  test)
	DRY_RUN="true"
	check_kdump_support;
	locate_debug_kernel;
	locate_kdump_kernel;
	kdump_load;
	kdump_test
	;;
  show)
	DRY_RUN="true"
	check_kdump_support;
	kdump_show
	;;
  load)
	check_kdump_support;
	locate_debug_kernel;
	locate_kdump_kernel;
	kdump_load;
	;;
  unload)
	kdump_unload;
	;;
  status)
	check_kdump_support;
	if [ `cat $sys_kexec_crash` -eq 1 ] ; then
		echo "current state   : ready to kdump";
	else
		echo "current state   : Not ready to kdump";
	fi
	exit 0;
	;;
  savecore)
	kdump_save_core
	exit $?
	;;
  help|-h*|--h*)
	kdump_help
	;;
  *)
	echo "Usage: $0 {help|test|show|status|load|unload|savecore}"
	exit 1
	;;
esac

exit 0