kexec-tools: bump version and add support for crashdump kernel

split kexec-tools into two packages, kexec and kdump.
* kexec to simply execute a new kernel
* kdump is for loading and collecting debris of a crashed kernel with
  support for kdump forensics.

In order to properly support booting into a crashkernel, an init script
as well as UCI configuration has been added.
As modifying the kernel cmdline is required for this to work in x86
platforms use an uci-defaults script to modify /boot/grub/grub.cfg.

To test collecting crash information, use the 'c' sysrq-trigger, ie.
echo c > /proc/sysrq-trigger

This should result in the crash kernel being executed and (depending
on the configution) dmesg and/or vmcore getting saved.

To check if the crash kernel was loaded properly, use the 'status'
command of the kdump init script.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
This commit is contained in:
Daniel Golle 2017-03-21 15:58:13 -06:00
parent 8b486ec2b5
commit 5e4bb476c0
5 changed files with 265 additions and 24 deletions

View file

@ -1,12 +1,5 @@
menu "Configuration"
depends on PACKAGE_kexec-tools
config KEXEC_TOOLS_kdump
bool
prompt "kdump support"
default n
help
Include the kdump utility.
depends on PACKAGE_kexec
config KEXEC_ZLIB
bool

View file

@ -8,12 +8,12 @@
include $(TOPDIR)/rules.mk
PKG_NAME:=kexec-tools
PKG_VERSION:=2.0.14-rc1
PKG_VERSION:=2.0.14
PKG_RELEASE:=1
PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
PKG_SOURCE_URL:=@KERNEL/linux/utils/kernel/kexec
PKG_HASH:=3fc505ff8d8a2d24c68aac5e6b4783997d5a086966ff3de8b05a0ceb27e5e23b
PKG_HASH:=ffb2e7e99d9d08754c6bc1922aed3c000094f318665d82a72ecc76c4ff1c0dc6
PKG_FIXUP:=autoreconf
@ -21,22 +21,49 @@ PKG_CONFIG_DEPENDS := CONFIG_KEXEC_ZLIB CONFIG_KEXEC_LZMA
include $(INCLUDE_DIR)/package.mk
define Package/kexec-tools
define Package/kexec-tools/Default
SECTION:=utils
CATEGORY:=Utilities
DEPENDS:=@armeb||@arm||@i386||@x86_64||@powerpc64||@mipsel||@mips +KEXEC_ZLIB:zlib +KEXEC_LZMA:liblzma
TITLE:=Kernel boots kernel
URL:=http://kernel.org/pub/linux/kernel/people/horms/kexec-tools/
MAINTAINER:=Florian Fainelli <florian@openwrt.org>
MENU:=1
endef
define Package/kexec-tools
$(call Package/kexec-tools/Default)
TITLE:=kexec-tools transition meta package
DEPENDS:=+kexec
endef
define Package/kexec-tools/description
kexec is a set of systems call that allows you to load
kexec is a set of system calls that allows you to load
another kernel from the currently executing Linux kernel.
The kexec utility allows to load and boot another kernel.
endef
define Package/kexec-tools/config
define Package/kexec
$(call Package/kexec-tools/Default)
TITLE:=Kernel boots kernel
DEPENDS:=\
@armeb||@arm||@i386||@x86_64||@powerpc64||@mipsel||@mips \
+KEXEC_ZLIB:zlib +KEXEC_LZMA:liblzma @KERNEL_KEXEC
endef
define Package/kexec/description
The kexec utility allows to load and boot another kernel.
endef
define Package/kdump
$(call Package/kexec-tools/Default)
TITLE:=Kernel crash analysis
DEPENDS:=+kexec @i386||@x86_64||@arm @KERNEL_CRASH_DUMP
endef
define Package/kdump/description
The kdump package allows to automatically boot into a
special kernel for analyzing kernel crashes using kdump.
endef
define Package/kexec/config
source "$(SOURCE)/Config.in"
endef
@ -65,24 +92,45 @@ CONFIGURE_VARS += \
BUILD_CC="$(HOSTCC)" \
TARGET_CC="$(TARGET_CC)"
kexec-extra-sbin-$(CONFIG_KEXEC_TOOLS_kdump) += kdump
define Build/Compile
$(MAKE) -C $(PKG_BUILD_DIR) DESTDIR="$(PKG_INSTALL_DIR)" all install
endef
define Package/kexec-tools/install
:
endef
define Package/kexec/install
$(INSTALL_DIR) $(1)/usr/sbin
$(INSTALL_BIN) \
$(addprefix $(PKG_INSTALL_DIR)/usr/sbin/, \
$(kexec-extra-sbin-y)) \
$(kexec-extra-bin-y) \
$(PKG_INSTALL_DIR)/usr/sbin/kexec \
$(1)/usr/sbin
$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/kexec $(1)/usr/sbin
# make a link for compatability with other distros
$(INSTALL_DIR) $(1)/sbin
$(LN) ../usr/sbin/kexec $(1)/sbin/kexec
endef
define Package/kdump/install
$(INSTALL_DIR) $(1)/usr/sbin $(1)/etc/init.d $(1)/etc/config $(1)/etc/uci-defaults
$(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/kdump $(PKG_INSTALL_DIR)/usr/sbin/vmcore-dmesg $(1)/usr/sbin
$(INSTALL_BIN) ./files/kdump.init $(1)/etc/init.d/kdump
$(INSTALL_BIN) ./files/kdump.defaults $(1)/etc/uci-defaults/kdump
$(INSTALL_CONF) ./files/kdump.config $(1)/etc/config/kdump
endef
define Package/kdump/prerm
#!/bin/sh
case $$(uname -m) in
i?86|x86_64)
if grep -q " crashkernel=" /boot/grub/grub.cfg; then
mount /boot -o remount,rw
sed -i 's/ crashkernel=[^ ]*//' /boot/grub/grub.cfg
mount /boot -o remount,ro
fi
;;
esac
endef
$(eval $(call BuildPackage,kexec-tools))
$(eval $(call BuildPackage,kexec))
$(eval $(call BuildPackage,kdump))

View file

@ -0,0 +1,7 @@
config kdump
option enabled '1'
option save_dmesg '1'
option save_vmcore '0'
# using an external partition to store vmcore is highly recommended!
# option path '/mnt/crashdump'

View file

@ -0,0 +1,11 @@
#!/bin/sh
case $(uname -m) in
i?86|x86_64)
if ! grep -q crashkernel /boot/grub/grub.cfg; then
mount /boot -o remount,rw
sed -i 's/linux.*/& crashkernel=32M@32M/' /boot/grub/grub.cfg
mount /boot -o remount,ro
fi
;;
esac

View file

@ -0,0 +1,182 @@
#!/bin/sh /etc/rc.common
START=41
STOP=98
EXTRA_COMMANDS="status"
EXTRA_HELP=" status Print crashkernel status"
verify_kdump() {
local cfg="$1"
local enabled
local path
local save_vmcore
local save_dmesg
config_get_bool enabled "$cfg" enabled 1
config_get_bool save_dmesg "$cfg" save_dmesg 1
config_get_bool save_vmcore "$cfg" save_vmcore 0
[ "$enabled" -gt 0 ] || return 2
[ "$save_dmesg" -gt 0 ] || [ "$save_vmcore" -gt 0 ] || return 2
config_get path "$cfg" path "/"
[ -d "$path" ] || mkdir -p "$path" 2>/dev/null || return 1
}
run_kdump() {
local cfg="$1"
local enabled
local path
local save_vmcore
local save_dmesg
config_get_bool enabled "$cfg" enabled 1
[ "$enabled" -gt 0 ] || return
config_get_bool save_dmesg "$cfg" save_dmesg 1
config_get_bool save_vmcore "$cfg" save_vmcore 0
config_get path "$cfg" path "/"
timestamp=$(date "+%Y%m%dT%H%M%S")
if [ "$save_vmcore" -eq 1 ]; then
# would like 'sparse' but busybox doesn't support it
dd if=/proc/vmcore of="$path/vmcore-$timestamp" conv=fsync bs=1M
fi
if [ "$save_dmesg" -eq 1 ]; then
vmcore-dmesg /proc/vmcore > "$path/dmesg-$timestamp"
fi
sync
reboot -f
}
find_kernel() {
. /lib/functions.sh
local kernel
kernel="$BOOT_IMAGE"
if [ -r "$kernel" ]; then
echo $kernel
return 0
fi
kernel="$(find_mtd_part kernel)"
if [ -r "$kernel" ]; then
echo $kernel
return 0
fi
for voldir in /sys/class/ubi/ubi*_*; do
[ ! -e "$voldir" ] && continue
if [ "$(cat "${voldir}/name")" = "kernel" ]; then
kernel="/dev/$(basename "$voldir")"
echo $kernel
return 0
fi
done
return 1
}
load_crashkernel() {
local append_cmdline
local kernel
kernel="$(find_kernel)"
[ $? -gt 0 ] && return 1
case "$(uname -m)" in
i?86|x86_64)
grep -q "crashkernel=" /proc/cmdline || return 1
append_cmdline="1 irqpoll reset_devices maxcpus=1"
;;
arm*)
append_cmdline="1 maxcpus=1 reset_devices"
;;
esac
kexec -p "$kernel" --reuse-cmdline --append="$append_cmdline"
return $?
}
start() {
local retval
if [ ! -e /sys/kernel/kexec_crash_loaded ]; then
return 1
fi
if [ -e /proc/vmcore ]; then
config_load kdump
config_foreach run_kdump kdump
else
config_load kdump
config_foreach verify_kdump kdump
retval=$?
[ $retval = 1 ] && return 1
[ $retval = 0 ] && load_crashkernel
return $?
fi
}
stop() {
[ "$(cat /sys/kernel/kexec_crash_loaded)" = "1" ] || return
if [ -e "$BOOT_IMAGE" ]; then
kexec -p -u "$BOOT_IMAGE"
fi
}
status() {
local retval kernel
if [ ! -e /sys/kernel/kexec_crash_loaded ]; then
echo "crashdump not supported by kernel"
return
fi
if [ $(cat /sys/kernel/kexec_crash_size) -eq 0 ]; then
echo "memory for crashdump kernel not reserved!"
echo "check crashkernel= kernel cmdline parameter"
echo "(a reboot is required after installing kdump)"
return
fi
kernel="$(find_kernel)"
if [ $? -gt 0 ]; then
echo "cannot find kernel image"
return
else
echo "using kernel image $kernel"
fi
echo -n "kdump configuration is "
config_load kdump
retval=$?
if [ $retval = 0 ]; then
if [ "$(config_foreach echo kdump)" ]; then
config_foreach verify_kdump kdump
retval=$?
else
retval=1
fi
fi
if [ $retval = 0 ]; then
echo "valid"
elif [ $retval = 2 ]; then
echo "disabled"
else
echo "BROKEN"
fi
echo -n "kexec crash kernel "
if [ "$(cat /sys/kernel/kexec_crash_loaded)" = "0" ]; then
echo -n "not "
fi
echo "loaded"
}