Combine soy sauce, sesame oil, grated ginger, and garlic in a large zip-top plastic bag.
Add pork tenderloin to bag; seal. Marinate in refrigerator 1 1/2 hours, turning occasionally. Preheat grill to medium-high heat.
Remove pork from marinade; discard marinade.
Sprinkle both sides of pork evenly with kosher salt.
Place pork on grill rack coated with cooking spray; grill 8 minutes. Turn pork over; grill 7 minutes or until a thermometer inserted into thickest portion of pork registers 14