The exit receives control with these characteristics:

• Supervisor state
• Key 0
• APF-authorized
• TCB or SRB mode
• AR mode
• AMODE(31)
• RMODE(ANY)
• Cross memory mode

The exit can change the characteristics during its processing. However, the exit must return to its caller with the same characteristics as on entry.

The exit runs in the cross memory mode in the ICSF address space. The CKDS records are ALET-qualified. ICSF supplies the address and the ALET of a CKDS record as parameters to the CKDS retrieval exit.

For information about cross memory mode and AR mode, see z/OS MVS Programming: Extended Addressability Guide.