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>
v19.07.3_mercusys_ac12_duma
Daniel Golle 7 years ago
parent 8b486ec2b5
commit 5e4bb476c0

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

@ -8,12 +8,12 @@
include $(TOPDIR)/rules.mk include $(TOPDIR)/rules.mk
PKG_NAME:=kexec-tools PKG_NAME:=kexec-tools
PKG_VERSION:=2.0.14-rc1 PKG_VERSION:=2.0.14
PKG_RELEASE:=1 PKG_RELEASE:=1
PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
PKG_SOURCE_URL:=@KERNEL/linux/utils/kernel/kexec PKG_SOURCE_URL:=@KERNEL/linux/utils/kernel/kexec
PKG_HASH:=3fc505ff8d8a2d24c68aac5e6b4783997d5a086966ff3de8b05a0ceb27e5e23b PKG_HASH:=ffb2e7e99d9d08754c6bc1922aed3c000094f318665d82a72ecc76c4ff1c0dc6
PKG_FIXUP:=autoreconf PKG_FIXUP:=autoreconf
@ -21,22 +21,49 @@ PKG_CONFIG_DEPENDS := CONFIG_KEXEC_ZLIB CONFIG_KEXEC_LZMA
include $(INCLUDE_DIR)/package.mk include $(INCLUDE_DIR)/package.mk
define Package/kexec-tools define Package/kexec-tools/Default
SECTION:=utils SECTION:=utils
CATEGORY:=Utilities 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/ URL:=http://kernel.org/pub/linux/kernel/people/horms/kexec-tools/
MAINTAINER:=Florian Fainelli <florian@openwrt.org> 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 endef
define Package/kexec-tools/description 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. another kernel from the currently executing Linux kernel.
The kexec utility allows to load and boot another kernel.
endef 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" source "$(SOURCE)/Config.in"
endef endef
@ -65,24 +92,45 @@ CONFIGURE_VARS += \
BUILD_CC="$(HOSTCC)" \ BUILD_CC="$(HOSTCC)" \
TARGET_CC="$(TARGET_CC)" TARGET_CC="$(TARGET_CC)"
kexec-extra-sbin-$(CONFIG_KEXEC_TOOLS_kdump) += kdump
define Build/Compile define Build/Compile
$(MAKE) -C $(PKG_BUILD_DIR) DESTDIR="$(PKG_INSTALL_DIR)" all install $(MAKE) -C $(PKG_BUILD_DIR) DESTDIR="$(PKG_INSTALL_DIR)" all install
endef endef
define Package/kexec-tools/install define Package/kexec-tools/install
:
endef
define Package/kexec/install
$(INSTALL_DIR) $(1)/usr/sbin $(INSTALL_DIR) $(1)/usr/sbin
$(INSTALL_BIN) \ $(INSTALL_BIN) $(PKG_INSTALL_DIR)/usr/sbin/kexec $(1)/usr/sbin
$(addprefix $(PKG_INSTALL_DIR)/usr/sbin/, \
$(kexec-extra-sbin-y)) \
$(kexec-extra-bin-y) \
$(PKG_INSTALL_DIR)/usr/sbin/kexec \
$(1)/usr/sbin
# make a link for compatability with other distros # make a link for compatability with other distros
$(INSTALL_DIR) $(1)/sbin $(INSTALL_DIR) $(1)/sbin
$(LN) ../usr/sbin/kexec $(1)/sbin/kexec $(LN) ../usr/sbin/kexec $(1)/sbin/kexec
endef 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-tools))
$(eval $(call BuildPackage,kexec))
$(eval $(call BuildPackage,kdump))

@ -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'

@ -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

@ -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"
}
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