I look around about missing symbols and try do something like this:
https://github.com/blondak/xpenology-kernel-symbols
because i'm on HP N40L i'm waiting for pci-e serial card to debug this, but feel free to try it too, it exports missing symbols to be able compile ata drivers (now i have probably kernel panic) but after inserting xpenology.ko i'm able insert modules which uses syno_libata_index_get.