Source : Free On-Line Dictionary of Computing

problem state
     
        {IBM} jargon for {user mode}, the opposite of "supervisor
        state".
     
        On IBM {System 360}, 370 and 390 {mainframe}s {privileged
        instruction}s may only be executed in "supervisor state".
        {Application program}s request the {operating system} to
        perform these operations by using the Supervisor Call (SVC)
        instruction.
     
        (1995-02-15)