get-grub-patches.sh

#!/bin/bash

versions="$(curl https://coreos.com/releases/releases.json 2>/dev/null | jq keys | jq .[] | tr -d '\"' |  tr '\n' ' ')"
mkdir -p ~/grub-info/

LINUX_MOD='usr/lib/grub/i386-pc/linux.module'
LINUX_DEBUG="/usr/lib/debug/${LINUX_MOD}.debug"

function download_release() {
	local major=$(cut -d. -f1 <<< $1)
	if [[ $major -lt 926 ]]; then
		return
	fi
	if [[ $major -gt 1722 ]]; then
		return
	fi
	if [[ -d grub-info/$1 ]]; then
		return
	fi
	echo "version $1"
	mkdir grub-info/$1
	pushd grub-info/$1

	gsutil -q cp "gs://builds.developer.core-os.net/sdk/amd64/$1/pkgs/sys-boot/grub-*tbz2" .
		
	for i in grub-*
	do
		mkdir $(basename -s .tbz2 $i)
		mv $i $(basename -s .tbz2 $i)
		pushd $(basename -s .tbz2 $i)
		qtbz2 -s $i
		tar xf ${i/.tbz2/.tar.bz2}
		popd
	done
	
	popd
}

for i in $versions
do
	download_release "$i"
done

for rel in grub-info/*
do
	for grubver in $rel/*
	do
		if [[ $(basename $grubver) == 'grub-*' ]]; then
			continue
		fi
		mod="$grubver/$LINUX_MOD"
		hashsum=$(sha512sum $grubver/usr/lib/grub/i386-pc/linux.mod | cut -d' ' -f1)
		if [[ -e $grubver/$LINUX_DEBUG ]]; then
			eu-unstrip $mod $grubver/$LINUX_DEBUG -o /tmp/abcde
			mod=/tmp/abcde
		fi
		offset="0x$(objdump -t $mod | grep linux_params | cut -d ' ' -f1)"
		
		if [[ -z $offset ]]; then
			echo $grubver failed
			continue
		fi
		textoffset="0x$(objdump -h -w linux.mod | grep .text | tr -s ' '|cut -d' ' -f7)"
		badval="$(($offset + (616*0x3fc) ))"

		goodval="$(($offset + 616 ))"
		# mangle it into a format usable bu printf
		goodval="\\x$(python -c "import re; print(('\\\x'.join(re.findall('..', format(${goodval}, '08x'))[::-1])))")"

		value="b8 $(python -c "import re; print((' '.join(re.findall('..', format(${badval}, '08x'))[::-1])))")"
		opcode="0x$(objdump -d $mod | grep "$value" | cut -d':' -f1 | tr -d ' ')"
		if [[ $opcode == "0x" ]]; then
			# some early CL versions has two binpkgs where only one has the bad code
			# skip versions that don't have bad code
			continue
		fi

		# +1 to account for the opcode byte
		fileoffset=$((${textoffset} + ${opcode} + 1))
		echo $hashsum $fileoffset $goodval
	done
done