On modern airliners we have audible stall warnings (ranging in complexity from a blaring horn to a voice saying "STALL. STALL. STALL."), stick shakers, stick pushers, and in some aircraft sophisticated flight envelope protection systems (control software that simply won't allow the pilot to stall the aircraft).
When everything is working as designed these systems either make it very difficult to stall an aircraft (you would have to ignore the audible warning, ignore the stick shaker, and either override or overpower the stick pusher), or impossible to do so (flight-envelope protection).
When things are not working as designed - e.g. if the pitot (airspeed) and angle-of-attack systems malfunction these protective systems can become ineffective, however in such a scenario any other automated protection system that we would seek to implement would have similar challenges to overcome (if the flight-envelope protection system can't determine that the aircraft is in a stall how would the hypothetical "stall recovery" system know that it should do its thing?)
The idea of airframe parachutes - even a "spin recovery drogue" - for airliners has its own problems and is a largely impractical solution. (I won't rehash the reasons here, but they are well covered in the linked question.)