To make room for Hall on the 40-man roster, Arizona designated right-handed pitcher Matt Stites for assignment.
Hall, 28, had a 3.46 ERA in 43 games last season with Triple-A Sacramento. He made his big league debut with the Giants on Sept. 3 against the Rockies. Hall allowed six earned runs in 8 1/3 innings over seven games.
Hall's best outing came against the Rockies on Oct. 2, when he struck out three over two scoreless innings.
Hall was the Giants' 19th-round pick in 2011 out of Southern University. He was added to the Giants' 40-man roster last fall and still has Minor League options.