It might be manageable if you exempt, e.g., CVTPTR, and only take hits for problem state user key.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Assembler List [[email protected]] on behalf of Gary Weinhold [[email protected]] Sent: Monday, March 27, 2023 8:11 PM To: [email protected] Subject: Re: Blocking Low core access from Assembler programs It may be possible to devise a slip trap that would exempt the master TCB, but it might catch many perfectly legitimate problem state accesses, like to access the CVT to start a pointer chase to an IBM or ISV service or control block. Gary Weinhold Senior Application Architect DATAKINETICS | Data Performance & Optimization Phone:+1.613.523.5500 x216 Email: [email protected] Visit us online at http://secure-web.cisco.com/16UeFBxcku8cR2ADGIuRL7W-UfkjT63YA5KkP5GbNDqhOwvhmBeq8ncf4DOuM-ncWsDAXD53pj4lzc0sPxESl2M1ScDXTBZikbsmL8yr38BlK8yg81Yg_lP_dx1oEONNr5nPokr9Q0X4YqduXITArxdbFu0Qjk2jiYVasJed39Jgwht7jn_B3j4Y1mwVMCFLDFJGdUAd71_Eq8TPKbGRHLIQ7myBcN-Y-ko3kvjyEZCGUa6Nts5-mKwrksq215N58nJsPnk6H6j8LgqAbn9UQttTvEp-hJSU1zvv5xFxltgRdg_mPe_TbpY_zmirjun4k-KquUvqAVA-KCOGsiP5Dp5z2qXr_FeCCQmiBYSk9pC3UqNIwvg65H5K88Yh_vWkXVBnevEwCIwoMb11dMV74MamqgJx5Zvg_xPI3WSrtonw/http%3A%2F%2Fwww.DKL.com E-mail Notification: The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system. ________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of Seymour J Metz <[email protected]> Sent: March 27, 2023 19:37 To: [email protected] <[email protected]> Subject: Re: Blocking Low core access from Assembler programs z/OS has a lot of code that requires access to the PSA. Making it inaccessible would break applications. Of course, the machine has no core. ________________________________________ From: IBM Mainframe Assembler List <[email protected]> on behalf of syama prasad <[email protected]> Sent: Monday, March 27, 2023 6:47 PM To: [email protected] Subject: Blocking Low core access from Assembler programs Hi, Is it possible to force an Assembler program to hit an access error if it tries to load data from the low core (page starting from address zero)?Assembler *PROCESS FLAG(PAGE0) " helps to find cases like MVC TARGET,1But will it be possible to have a run time detection and possibly a dump if the program tries to do things likeLA R5,1MVC TARGET,0(R5)Basically, any way to restrict access of an application program to PSA- first control block? Regards,Syama
