Preheat oven to 250. Wash pork and rub with salt. Slice the bananas in to 8 long pieces. Place the banana strips on a large piece of heavy-duty aluminum foil and place the pork roast on top. Sprinkle roast (liberally) with liquid smoke and wrap the roast tightly. Place the wrapped roast in a covered glass roasting dish (or use a Dutch oven). Bake in oven for at least 7 hours. Remove from oven, unwrap roast, remove and discard cooked bananas and shred the 'kalua' pig. Serve with rice or stir fry with chopped cabbage.