@futurebird As a Pakistani, I think "we don't know" would be honest answer a lot of time. Some things I would assume are present by default: ginger, garlic, turmeric, red chili powder and garam masala.
I actually have never looked up what goes in garam masala (and I very much doubt there is a canonical composition), since I always buy powdered one. What I remember seeing in it during my childhood: black pepper, cloves, black cardamom, cinnamon, cumin seeds, coriander seeds and (a bit more doubtful than the rest) fennel seeds.
So, I imagine it is hard to keep track of exact list of ingredients.