Sift flour, salt and soda together into a bowl. Blend in brown sugar and oatmeal. Cut in shortening until particles are size of small peas. Press 1/2 of mixture into bottom of ungreased 9"x13" pan. Spread with cherry pie filling (I usually use 2 cans). Cover with remaining oatmeal mixture. Press down gently with a spoon or your fingers. Bake at 350F, 25-30 minutes. Serve warm with whipped topping or ice cream.