(By Matthew S. Dryer): "This map shows the position of possessive affixes on nouns... Note that the term possessive affix is used by different linguists for two very different sorts of affixes. This chapter uses the term for affixes like those in (1) which code the person, number, and/or gender of a possessor and which appear on a noun denoting the entity which is possessed. The term is occasionally used for what will be called here genitive affixes, case affixes which occur on nouns denoting possessors, to indicate that these nouns denote the possessor of something expressed by a separate noun..."
Dryer's chapter is about affixal person indexes (though he does not use that term), and he is careful to distinguish them from genitive affixes.