On Tue, 26 Apr 2011 07:59:27 -0400 Peter Relson <[email protected]> wrote:
:>>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)? :>I intentionally phrased the question the way I did, although no one :>answered it in that spirit. The answer, based solely on the posts :>so far, appears to be "no". SVC screening allows one to specify which SVCs will go to the coded routine instead of the standard SVC. :>There are a lot of other entertaining, interesting, probably useful, :>but nevertheless wholly unsupported, uses that have been found for :>SVC screening. Is it your statement that the only "supported" use of this routine is to fail the SVC call, not to do alternate processing? :>I do mean to provoke thought; I do not mean to cause alarm. As long as :>the SVC screening routine does everything right, so that the user :>gets what the user should get in all cases, I don't have overly much :>problem with this misuse. But very often that is not the case, including :>functional problems or even system integrity problems, related to :>examining the user parameters or due to making the SVC appear that it :>had not come from the user who actually issued it. :>Note that users who use SVCUPDTE to front-end SVCs often inject :>similar problems. Or supervisor state PC routines. Etc. Supervisor state routines callable by problem state have to validate everything. -- 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: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
