On Sun, 11 Jun 2017 15:40:49 -0500, Paul Gilmartin <[email protected]> wrote:

>In the Program Management UG and Ref, I see:
>RENT
>    ... A reenterable module is ordinarily expected not to modify
>    its own code. In some cases, MVS protects the reentrant module's
>    virtual storage so that it cannot be modified except by a
>    program running in key 0. These cases include programs which
>    the system treats as having been loaded from an authorized
>    library, ...
>
>Is that right?  It seems to be describing REFR, not RENT.  And
>the "treats as" waffling?  Is that referring to LPA, regardless of
>load module attributes?  And "include" hints at other cases, not
>mentioned.

It's descibing RENT, because for programs linked as RENT MVS places the load 
module into key 0 storage if the program was loaded from a library treated as 
APF-authorized. Such programs can modify themselves if running in key 0.

If they were REFR, and REFRPROT were in effect, they would be in key 0 storage 
and page-protected, and could not modify themselves.

(In general, I think that programs that are REFR should also be RENT, but I 
don't know if the binder enforces that.)

LPA is certainly one case where the "treated as authorized" applies for 
libraries. I don't recall if there are others, but Peter or Jim will probably 
know :)

-- 
Walt

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