I have to say I find it hard to see an appreciable risk (especially for
some innocent code to accidentally issue the MODESET SVC), but of course no
risk is zero.

For the record I chose (off the cuff) to use NC on some low storage with
itself, because it would never actually attempt to alter that storage, but
only to store the same values back again.

So it might seem a bit of a cowboy move, but it's looks unlikely to cause
trouble in reality.

Roops

On Mon, 22 Apr 2024, 13:21 Peter Relson, <[email protected]> wrote:

> Bernd O wrote
> <snip>
> I'd suggest to be very careful with such codings;
> a co-worker some years ago did this and - by accident - the code ran
> privileged,
> which caused the whole LPAR to hang.
>
> Same goes for ST at address zero, which was suggested by another poster.
> </snip>
>
> I challenge both of those.
>
> The first will never happen unless something changed to key 0 (being
> privileged is relevant only to the extent that you could then change to key
> 0). And that doesn't happen without intent.
>
> The second will never happen outside of the OS itself in the absence of an
> APARable z/OS error (related to what we refer to as low-core protect).
>
> 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
>

----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN

Reply via email to