1 files changed, 102 insertions, 3 deletions
diff --git a/package/base-files/files/lib/upgrade/stage2 b/package/base-files/files/lib/upgrade/stage2
index 4e2aa3a23c..cc8047d988 100755
--- a/package/base-files/files/lib/upgrade/stage2
+++ b/package/base-files/files/lib/upgrade/stage2
@@ -24,6 +24,104 @@ export CONF_TAR=/tmp/sysupgrade.tgz
 include /lib/upgrade
 
 
+supivot() { # <new_root> <old_root>
+	/bin/mount | grep "on $1 type" 2>&- 1>&- || /bin/mount -o bind $1 $1
+	mkdir -p $1$2 $1/proc $1/sys $1/dev $1/tmp $1/overlay && \
+	/bin/mount -o noatime,move /proc $1/proc && \
+	pivot_root $1 $1$2 || {
+		/bin/umount -l $1 $1
+		return 1
+	}
+
+	/bin/mount -o noatime,move $2/sys /sys
+	/bin/mount -o noatime,move $2/dev /dev
+	/bin/mount -o noatime,move $2/tmp /tmp
+	/bin/mount -o noatime,move $2/overlay /overlay 2>&-
+	return 0
+}
+
+switch_to_ramfs() {
+	install_bin /bin/busybox /bin/ash /bin/sh /bin/mount /bin/umount	\
+		/sbin/pivot_root /sbin/reboot /bin/sync /bin/dd	/bin/grep       \
+		/bin/cp /bin/mv /bin/tar /usr/bin/md5sum "/usr/bin/[" /bin/dd	\
+		/bin/vi /bin/ls /bin/cat /usr/bin/awk /usr/bin/hexdump		\
+		/bin/sleep /bin/zcat /usr/bin/bzcat /usr/bin/printf /usr/bin/wc \
+		/bin/cut /usr/bin/printf /bin/sync /bin/mkdir /bin/rmdir	\
+		/bin/rm /usr/bin/basename /bin/kill /bin/chmod /usr/bin/find \
+		/bin/mknod
+
+	install_bin /sbin/mtd
+	install_bin /sbin/mount_root
+	install_bin /sbin/snapshot
+	install_bin /sbin/snapshot_tool
+	install_bin /usr/sbin/ubiupdatevol
+	install_bin /usr/sbin/ubiattach
+	install_bin /usr/sbin/ubiblock
+	install_bin /usr/sbin/ubiformat
+	install_bin /usr/sbin/ubidetach
+	install_bin /usr/sbin/ubirsvol
+	install_bin /usr/sbin/ubirmvol
+	install_bin /usr/sbin/ubimkvol
+	install_bin /usr/sbin/partx
+	install_bin /usr/sbin/losetup
+	install_bin /usr/sbin/mkfs.ext4
+	for file in $RAMFS_COPY_BIN; do
+		install_bin ${file//:/ }
+	done
+	install_file /etc/resolv.conf /lib/*.sh /lib/functions/*.sh /lib/upgrade/*.sh $RAMFS_COPY_DATA
+
+	[ -L "/lib64" ] && ln -s /lib $RAM_ROOT/lib64
+
+	supivot $RAM_ROOT /mnt || {
+		echo "Failed to switch over to ramfs. Please reboot."
+		exit 1
+	}
+
+	/bin/mount -o remount,ro /mnt
+	/bin/umount -l /mnt
+
+	grep /overlay /proc/mounts > /dev/null && {
+		/bin/mount -o noatime,remount,ro /overlay
+		/bin/umount -l /overlay
+	}
+}
+
+kill_remaining() { # [ <signal> [ <loop> ] ]
+	local sig="${1:-TERM}"
+	local loop="${2:-0}"
+	local run=true
+	local stat
+
+	echo -n "Sending $sig to remaining processes ... "
+
+	while $run; do
+		run=false
+		for stat in /proc/[0-9]*/stat; do
+			[ -f "$stat" ] || continue
+
+			local pid name state ppid rest
+			read pid name state ppid rest < $stat
+			name="${name#(}"; name="${name%)}"
+
+			# Skip PID1, ourself and our children
+			[ $pid -ne 1 -a $pid -ne $$ -a $ppid -ne $$ ] || continue
+
+			local cmdline
+			read cmdline < /proc/$pid/cmdline
+
+			# Skip kernel threads
+			[ -n "$cmdline" ] || continue
+
+			echo -n "$name "
+			kill -$sig $pid 2>/dev/null
+
+			[ $loop -eq 1 ] && run=true
+		done
+	done
+	echo ""
+}
+
+
 killall -9 telnetd
 killall -9 dropbear
 killall -9 ash
@@ -44,7 +142,8 @@ fi
 
 if [ -n "$(rootfs_type)" ]; then
 	echo "Switching to ramdisk..."
-	run_ramfs "$COMMAND"
-else
-	exec /bin/busybox ash -c "$COMMAND"
+	switch_to_ramfs
 fi
+
+# Exec new shell from ramfs
+exec /bin/busybox ash -c "$COMMAND"