I want to make hair particles point in an upward direction only, not in the direction according to emitter mesh.
Just wanted to show the final render, environment bit dull though.
It should work the same way in 2.7: You need to enable the Advanced option, then the Rotation option, and choose Orientation Axis > Global Z (or whatever orientation you want, you may need to rotate your particle object in Edit mode to align it with the axis you want):