Initial version of SteamOS kdump

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>

kdump_load.sh

@@ -0,0 +1,47 @@
+#!/bin/sh
+#
+#  SPDX-License-Identifier: LGPL-2.1+
+#
+#  Copyright (c) 2021 Valve.
+#
+#  Script that loads the panic kdump (from within a systemd service)
+#  or if the proper parameters are passed, either creates the minimal
+#  kdump initramfs for the running kernel or removes all the previously created.
+#  ones. Since it runs on boot time, avoid failing here to not risk a boot hang.
+#
+
+if [ ! -f "/etc/default/kdump" ]; then
+	exit 0
+fi
+
+. /etc/default/kdump
+
+# Fragile way for finding the proper mount point for DEVNODE:
+DEVN_MOUNTED=$(mount |grep "${MOUNT_DEVNODE}" | head -n1 | cut -f3 -d\ )
+KDUMP_FOLDER="${DEVN_MOUNTED}/${KDUMP_FOLDER}"
+
+if [ "$1" == "initrd" ]; then
+	mkdir -p "${KDUMP_FOLDER}"
+	rm -f "${KDUMP_FOLDER}/kdump-initrd-$(uname -r).img"
+
+	echo "Creating the kdump initramfs for kernel \"$(uname -r)\" ..."
+	dracut --no-early-microcode --host-only -q -m\
+	"bash systemd systemd-initrd systemd-sysusers modsign dbus-daemon kdump dbus udev-rules dracut-systemd base fs-lib shutdown"\
+	--kver $(uname -r) "${KDUMP_FOLDER}/kdump-initrd-$(uname -r).img"
+
+	exit 0
+fi
+
+if [ "$1" == "clear" ]; then
+	rm -f ${KDUMP_FOLDER}/kdump-initrd-*
+	exit 0
+fi
+
+# Stolen from Debian kdump
+KDUMP_CMDLINE=$(sed -re 's/(^| )(crashkernel|hugepages|hugepagesz)=[^ ]*//g;s/"/\\\\"/' /proc/cmdline)
+
+KDUMP_CMDLINE="${KDUMP_CMDLINE} panic=-1 oops=panic fsck.mode=force fsck.repair=yes nr_cpus=1 reset_devices"
+VMLINUX="$(grep -o 'BOOT_IMAGE=[^ ]*' /proc/cmdline)"
+
+kexec -s -p "${VMLINUX#*BOOT_IMAGE=}" --initrd "${KDUMP_FOLDER}/kdump-initrd-$(uname -r).img" --append="${KDUMP_CMDLINE}" || true
+exit 0