On Mon, 25 Apr 2011 07:48:38 -0400 Peter Relson <rel...@us.ibm.com> wrote:
:>One point about SVCs vs PC's: unless you go fairly far out of your way, a :>PC routine will not confer additional key/state authorization to its :>invoker. An SVC routine easily can do that by manipulating control block :>fields. This conferrence leads directly to many of (or is itself) the :>system integrity issue(s) related to a "magic SVC". A supervisor state basic PC to branch to an address in an arbitrary register - or to branch back to the address loaded into R14. :>Ed Jaffe mentioned SVC screening :>Curious: Does anyone use SVC screening for its documented intended :>purpose: to define those SVCs that a particular task is allowed to issue :>(and conversely those that it is not allowed to issue)? The OperAider package that I wrote 20+ years ago did to allow full TSO emulation (including TGET/TPUT) without a terminal. -- Binyamin Dissen <bdis...@dissensoftware.com> 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 lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
