How do I stop weeds coming up?

-10 years ago my gran had her front lawn removed and pebbles put down instead, but over the years countless weeds and even bushes have came up through the lining. How do I stop this or would I be easier to get rid of the pebbles and if so how would I get rid off it allthe landscapers should have put down cloth before the gravel went down. Since that hasn't been done, the weeds and grass will keep coming. You can hit them with Roundup to kill them, or have the stones taken up, the cloth put down, and stones replaced.
look for something called pre-emerger,, this kills the roots before they sprout
Gasoline..Well thats if you dont want anything comin up...