In general a Ger is called up as [name] Ben Avraham. However, what if the Ger converted as a child together with his parents? I would think it is the same but I recently saw someone who is in that situation who was called up Ben [his father's hebrew name]. Is there a source for either way?
The Gemara in Yevamos 101: mentions that Rav Shmuel the son of Yehuda reports about himself: ואנא גר אנא (“I am a convert”), yet he is named בר יהודה (son of Yehuda), Rashi explains, that this is since his natural father converted together with him.