under linux, you can also create a file .exiv2 under your home directory, with a structure like:
[sony]
28=Tamron SP AF 90mm F2.8 Di Macro
…
i.e. a section per camera (body) brand, then for each lens a line with
<lensID>=<lensfun name>
This will make the exiv2 library use the name you specified for the given lens ID, overriding the default name.
See the exiv2 manpage for exact details