White smoke is generally for two reasons:-
1- If engine is properly tuned, then water vapors comes out of your exhaust in white color , this generally happens with cold engine or in very cold weather.
2- If engine is hot (you run your car for at least 10,15 mins) and then smoke comes out then it is oil that is burning.
if oil is mixing in your cylinders causing white smokes, it could be due to weak or faulty Head Gaskit or leak in your cylinders. In next oil change make sure that you measure the oil coming out of engine, not just try to eye-ball it (desi ustad will say oil pora nikla hy tension na lain) , you put that oil back in oil bottle and see how much oil is reduced. If more than half liter oil is missing , bro you need to do something with Engine. Either head gasket or cylinder leaked.
If that is not the case then you better put some high octane in your engine (Full Tank of High Octane) and run car with hard paddle for few days also reset your Car CPU after you fill your tank with High Octane (don't put single drop of regular petrol for this time only). After few days your CPU should be able to get some data and if there is problem with faulty injectors, it might go away.