Paul Gilmartin wrote:
On Sat, 10 Jun 2017 07:27:15 -0400, Peter Relson wrote:
REFRPROT extends this to programs that are not loaded from an
APF authorized library.
Actually, REFRPROT extends this to programs that are bound with the REFR
option regardless of module authorization or library authorization.
And it goes further because it page-protects, which would cause the
program to blow up even if were running key 0 if it attempted to store
into itself.
I remain mystified, Why was not the REFRPROT behavior the default
(or only) behavior ever since the inception of the REFR attribute?
o Is there a performance penalty for REFRPROT that developers
wanted to circumvent for problem programs? Contrariwise, it seems
that coding a test for the authorized status of the load library was
needless effort.
o Did the developers assume, very incorrectly IMO, that they were
extending a courtesy to application programmers by permitting
programs that modified themselves to be marked REFR?
z/OS was not created out of whole cloth in a single release, nor was the
hardware architecture on which it runs. In particular, page protection
was not there when REFR was first implemented. A quick search indicates
the latter was new in the 3090 announcement.
REFR was implemented quite some time before that.
--
John Eells
IBM Poughkeepsie
ee...@us.ibm.com
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
