BPX4MPR (mprotect) example

The following code changes the protection of a memory mapped area. For the callable service, see mprotect (BPX1MPR, BPX4MPR) — Set protection of memory mapping. AMODE 31 callers use BPX1MPR (mprotect) example.

                                              
         CALL  BPX4MPR,              set protection of a mapped area   +
               (MAP_ADDRESS,         Input: address of mapped area     +
               MAP_LENGTH,           Input: area length                +
               =A(PROT_READ),        Input: Protection options         +
               RETVAL,               Return value: 0 or -1             +
               RETCODE,              Return code                       +
               RSNCODE),             Reason code                       +
               MF=(E,PLIST)          ----------------------------------