Accidentally slow roasted pork at 125 F instead of 225 F. Do I have to throw it out or can I just raise the temperature and cook longer?

125 degrees is within the danger zone for bacterial growth, so if it’s been in there for more than two hours I would think it might be risky.

Check the internal temperature, should be between 145 and 160 degrees for medium to medium-rare; when taken out of the oven, let it rest at least 15 minutes, the temperature will go up. If below 145 turn up the oven anywhere from 225 to 350 to finish cooking. If not brown enough use the higher temperature. If close to 160 remove from the oven, turn the oven up to 450 when that is reached return meat to the oven but watch carefully so as not to burn the meat or let the internal temperature get too high; that would make it very dry.