Exit environment

The user exit receives control in the following environment:

• Supervisor state, key zero.
• Running in the ASID of the process, except for the pre-process termination exit, which runs in the master address space if the address space of the process was terminated.

Register usage:

• On entry to the user exit, register 1 points to the Process Exit Data Block (PEDB).
• For the preprocess initiation exit, if the value returned in register 15 is > 4, the process initiation request is rejected. For all other exit points, the return code in register 15 is ignored.