The fixup patch does NOT change the generated assembly code for the 3 functions in xen/common/lzo.c on both amd64/arm64: - amd64: between the first patch (*ubuntu2.1) and this fixup (*ubuntu2.2), and - arm64: between the original package (*ubuntu2) and this fixup (*ubuntu2.2). Details: $ wget https://launchpad.net/~mfo/+archive/ubuntu/lp1956166/+files/xen-hypervisor-4.11-amd64_4.11.3+24-g14b62ab3e5-1ubuntu2.1_amd64.deb $ wget https://launchpad.net/~mfo/+archive/ubuntu/lp1956166/+files/xen-hypervisor-4.11-amd64_4.11.3+24-g14b62ab3e5-1ubuntu2.2_amd64.deb $ https://launchpad.net/ubuntu/+archive/primary/+files/xen-hypervisor-4.11-arm64_4.11.3+24-g14b62ab3e5-1ubuntu2_arm64.deb $ wget https://launchpad.net/~mfo/+archive/ubuntu/lp1956166/+files/xen-hypervisor-4.11-arm64_4.11.3+24-g14b62ab3e5-1ubuntu2.2_arm64.deb $ ls -1 xen-hypervisor-4.11-amd64_4.11.3+24-g14b62ab3e5-1ubuntu2.1_amd64.deb xen-hypervisor-4.11-amd64_4.11.3+24-g14b62ab3e5-1ubuntu2.2_amd64.deb xen-hypervisor-4.11-arm64_4.11.3+24-g14b62ab3e5-1ubuntu2.2_arm64.deb xen-hypervisor-4.11-arm64_4.11.3+24-g14b62ab3e5-1ubuntu2_arm64.deb $ for ARCH in amd64 arm64; do for VERSION in 4.11.3+24-g14b62ab3e5-1ubuntu2{,.1,.2}; do DEB="xen-hypervisor-4.11-${ARCH}_${VERSION}_${ARCH}.deb" [ -f "$DEB" ] || continue DIR="xen-4.11-${ARCH}-${VERSION}" DIS="xen-4.11-${ARCH}-${VERSION}.disass" OBJDUMP='objdump' [ "$ARCH" != 'arm64' ] || OBJDUMP='aarch64-linux-gnu-objdump' dpkg-deb -x $DEB $DIR gunzip $DIR/usr/lib/debug/xen-syms-4.11.4-pre.gz $OBJDUMP -d $DIR/usr/lib/debug/xen-syms-4.11.4-pre > $DIS for FUNC in lzo1x_1_do_compress lzo1x_1_compress lzo1x_decompress_safe; do sed -n "/<${FUNC}>:/,/^\$/p" $DIS | cut -d: -f2- > $DIS.func-$FUNC done done done $ md5sum xen-4.11-amd64-*.func-* | sort 163d549302aad6dfd82f7669e2f2aa65 xen-4.11-amd64-4.11.3+24-g14b62ab3e5-1ubuntu2.1.disass.func-lzo1x_1_compress 163d549302aad6dfd82f7669e2f2aa65 xen-4.11-amd64-4.11.3+24-g14b62ab3e5-1ubuntu2.2.disass.func-lzo1x_1_compress de4dc27fc2584edc6a33183abe34cc24 xen-4.11-amd64-4.11.3+24-g14b62ab3e5-1ubuntu2.1.disass.func-lzo1x_1_do_compress de4dc27fc2584edc6a33183abe34cc24 xen-4.11-amd64-4.11.3+24-g14b62ab3e5-1ubuntu2.2.disass.func-lzo1x_1_do_compress e68052e9060777fd445056132b4de031 xen-4.11-amd64-4.11.3+24-g14b62ab3e5-1ubuntu2.1.disass.func-lzo1x_decompress_safe e68052e9060777fd445056132b4de031 xen-4.11-amd64-4.11.3+24-g14b62ab3e5-1ubuntu2.2.disass.func-lzo1x_decompress_safe $ md5sum xen-4.11-arm64-*.func-* | sort 4cd4f9d881190842449f23f8e2ac0dd1 xen-4.11-arm64-4.11.3+24-g14b62ab3e5-1ubuntu2.2.disass.func-lzo1x_decompress_safe 4cd4f9d881190842449f23f8e2ac0dd1 xen-4.11-arm64-4.11.3+24-g14b62ab3e5-1ubuntu2.disass.func-lzo1x_decompress_safe c100e134e2086017d15021b8ef38be7e xen-4.11-arm64-4.11.3+24-g14b62ab3e5-1ubuntu2.2.disass.func-lzo1x_1_do_compress c100e134e2086017d15021b8ef38be7e xen-4.11-arm64-4.11.3+24-g14b62ab3e5-1ubuntu2.disass.func-lzo1x_1_do_compress e3e70b078204d5171b4d45d1f8fc1845 xen-4.11-arm64-4.11.3+24-g14b62ab3e5-1ubuntu2.2.disass.func-lzo1x_1_compress e3e70b078204d5171b4d45d1f8fc1845 xen-4.11-arm64-4.11.3+24-g14b62ab3e5-1ubuntu2.disass.func-lzo1x_1_compress ~/git/git-ubuntu/xen$ grep -B3 ^{ xen/common/lzo.c | grep '^[^{ ]' lzo1x_1_do_compress(const unsigned char *in, size_t in_len, -- int lzo1x_1_compress(const unsigned char *in, size_t in_len, -- int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,