I would argue that the principal of "least astonishment" would suggest that granting key0 would not imply the loss of current key. But I guess doc is doc.
On Wed, 14 Dec 2016 08:38:50 -0500 Peter Relson <[email protected]> wrote: :>>Yep, it is a bug. :> :>>The PSW key mask has key 0 and key9 after the combination. Not key 8. I :>would :>>not expect MODESET to alter the key mask. :> :>No it is not a bug. The "expectation" is incorrect. The updating of the :>PKM is fully documented and is what we wanted it to be. :> :>If you want to be switching keys, then why not simply be in supervisor :>state so that you can use SPKA without concern about the PKM? :> :>MODESET MODE=SUP (maybe with KEY=ZERO) :>... use SPKA as you will :>MODESET MODE=PROB (maybe with KEY=NZERO) :> :>I certainly have no objection to changing the documentation that currently :>has this: :> :>The MODE parameter specifies whether bit 15 of the PSW is to be set to one :>or zero. When PSW bit 15 is one, the processor is in the problem state. :>For problem state, ... :> :>to this: :> :>The MODE parameter specifies whether bit 15 of the PSW is to be set to one :>or zero. :> :>When PSW bit 15 is one, the processor is in the problem state. For problem :>state, ... :> :>This is the same wording, just not placing the "When" sentence in the same :>paragraph, since regardless of the MODE parameter, every PSW has a "bit :>15". :> :>FWIW: MODESET long pre-dated the change of SPKA to be semi-privileged. :>Thus it was written "knowing" that SPKA would be done while in supervisor :>state (hence the MODE=SUP...MODE=PROB pairing). The introduction of :>semi-privileged SPKA coupled with the use of key=9 led to the desire to :>continue allowing the switching between the "current key" and "key=9" :>while in problem state. Other key switching could/should be done in :>supervisor state or, since you used the MODESET SVC to "switch from" then :>using the MODESET SVC to switch back. Could additional functionality have :>been provided to allow you to ask for a different set of rules when :>building the PKM? Sure. But changing the rules will never happen for :>compatibility reasons. And implementing additional rules will not happen :>unless there is sufficient business justifiation to cover the cost (and I :>am skeptical that such justification exists). :> :>Peter Relson :>z/OS Core Technology Design :> :> :>---------------------------------------------------------------------- :>For IBM-MAIN subscribe / signoff / archive access instructions, :>send email to [email protected] with the message: INFO IBM-MAIN -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
