A dirty air filter will restrict how much air is reaching the engine and can cause the chainsaw to work harder than it should. Over time, it will overheat. Check the air filter and either clean or replace it.
If a significant amount of smoke is coming from the exhaust while the chainsaw is idling. You should try adjusting the idle speed as it may be idling too fast.
03 - Too much oil
It is possible you have added more oil than you should have into the fuel. Follow your manual to be sure you are mixing in the proper ratios.
04 - Chain and guide bar
If you notice smoke coming from the bar and chain area, check the guide bar oil reservoir to make sure you have enough oil. If you do not, fill it with oil to make sure the chain and bar are getting the lubrication they need. If it does already have oil, make sure you can see oil exiting the reservoir to lubricate the chain. Lastly, check the tension of the chain on the bar to make sure it is not too tight.