Choosing between the PADCHK and NOPADCHK operands

With the RDEFINE and RALTER commands for PROGRAM profiles, you can also specify PADCHK or NOPADCHK with the ADDMEM operand. Your choice affects how PADS operates, and which programs you must specify in the conditional access list for a data set when using PADS.

During PADS processing, RACF® looks at the program that issued the OPEN for a data set and at other programs executing in the user's program environment. For example, in a TSO environment, when a user runs a program, such as PROG1, other programs will most likely be running concurrently (including such programs as ISPF and various parts of TSO/E). When RACF makes its decision to allow access through PADS, you must have one program in the conditional access list. This can either be the program that issued the OPEN or a higher program in the execution hierarchy (as mentioned before). Additionally, if the user has any other non-LPA programs active, and you defined those programs with PADCHK, you must include them in the conditional access list as well.

RACF also checks the PADCHK/NOPADCHK status of a program when a user tries to run a new program. RACF checks if the user has any data sets already open using PADS. If so, and if you define the new program with PADCHK, RACF ensures that the program is included in the data set's conditional access list before allowing the user to run the program.

PADCHK is the default when you define a PROGRAM to RACF or when you create a new ADDMEM entry for an existing PROGRAM profile.

Guidelines:

If you are defining a program that you trust to operate in a safe manner and not attempt to violate security, specify NOPADCHK to help minimize the size of your conditional access lists and the work you need to do to administer them. Use NOPADCHK for the PROGRAM ** or PROGRAM * profiles and for any other cases where you trust a program to access only the data it should.
PADCHK might be most appropriate for user-written programs that are not completely trusted. This includes the case where you are willing to call them controlled and define them with PROGRAM profiles so they can use PADS, but you want them usable only with data sets you have specifically authorized them to. You do not trust them to function appropriately in an environment with other programs running that also make use of PADS.
For best results, do not mix PADCHK and NOPADCHK definitions in the same PROGRAM profile. When some members of a PROGRAM profile have been defined with PADCHK and some with NOPADCHK, RACF uses PADCHK for all members.