This is my version of rub for any kind of pork. I use it for pork shoulder or pork butt(which are the same just has 2 names).
3/4 cup of brown sugar
2 teaspoon of dried or garlic powder
3 tablespoons of salt
4 tablespoons paprika
If you want to add some spice to the rub you can use 1 tablespoon of you favorite dried peppers