GP is wondering whether the original poster is allowed to use code under the GPL license by his employer. This license requires derived code to be distributed under the same license, which companies may not want to do because trade secrets etc.
Google for "BSD linked list" and get 293000 results. Its an old data structure, much older than the GPL. Also its very popular. Google for "ruby linked list gem" and simply use a debugged library. Or any other language of your choice. Being a very popular data structure there likely exist implementations under most licenses for most languages. So it just struck me as weird that in 2013 someone would cut-n-paste reimplement one found in the kernel other than for obvious academic or educational interest or direct interface with the kernel (device driver author?)
