The initialization and termination security exits run in task mode in the ICSF address space. The passed storage pointers specify an address in the ICSF address space and are not ALET-qualified. There are essentially no restrictions on the use of z/OS services for these exits.

ICSF calls the security service exit and the security keys exit in cross memory mode after a space switch PC. The security service exit runs in the ICSF address space, which is the primary address space. The security key exit runs in cross memory and AR mode.