Programming considerations

The exits must follow standard linkage conventions. They must save the registers on entry and restore the registers when they return. The exits must be reentrant and reusable.

The exits can use the I/O service routines through the assembler macro instructions STACK, PUTLINE, GETLINE, and PUTGET. These macro instructions require the addresses of the ECT and UPT, which the logon processor passes to the exit. For information about the I/O service routines, see .

The exits must do the following for each parameter that they return:

Move the data it wants to return to the logon processor into the appropriate parameter
Update the current length of the data in the parameter
Set the appropriate control switch bit on if a bit is required for the parameter

For more information about the parameters and the control switch bits, see Entry specifications.

For z/OSMF ISPF users, where a RACINIT has already been done by CEA before the exit is called, you may want to bypass your normal exit processing. The best way to determine that your exit is being called for a z/OSMF ISPF user is to examine the LWAWBSPF bit in the LWA control block pointed to by the ASXBLWA pointer. This bit will be set for z/OSMF ISPF users.

You use the control switch bit, Store Password in TSB, and the New Password and Group parameters for users who are defined to RACF®. A user is defined to RACF if:

The user ID information is stored in the UADS and the user is also defined to RACF, or
The user ID information is stored in the RACF data base

For more information about defining TSO/E users in the RACF data base instead of in the UADS, see Maintaining the UADS, RACF data base, and broadcast data set.