Already exists from IBM: Prime PSA. Keith Moe Amdahl/BMC retired
On Wednesday, March 29, 2023, 04:24:25 PM PDT, Charles Mills <charl...@mcn.org> wrote: Did anyone suggest this before? On ***a test system only*** writing a special privileged program to fill all of the addresses from 0 to x'7F' except x'10'-x'13' with X'FF's. That might trigger errors and expose programs that were surviving the use of "normal" values from low addresses. And yes, you would have to account for prefixing. And please correct me if this makes no sense. I have not been real conversant with the exact usage of low memory since the early S/370 days. Charles -----Original Message----- From: IBM Mainframe Assembler List [mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] On Behalf Of syama prasad Sent: Wednesday, March 29, 2023 4:09 PM To: ASSEMBLER-LIST@LISTSERV.UGA.EDU Subject: Re: Blocking Low core access from Assembler programs Hi, Thanks for all the responses. It looks like there is no practical way to detect unintentional run-time access to page zero. Programs range fromĀ 50+ years old to quite recent. a recompile of everything with FLAG(PAGE0) and fixing obvious errors, followed by a test environment run of a few months under zOS 2.5 to catch any run-time errors seems to be the best way forward.