SRBs can do I/O. They can't do SVC instructions, however. You can start an I/O request without an SVC if you use the STARTIO macro, which requires your code's being authorized. You can know when the I/O is complete by testing an ECB's completion code byte but not doing a WAIT on it. It's more difficult to design an application that is heavily I/O bound using only SRBs, but it can be done. A STARTIO can also be used to get the next I/O started even if your code is disabled for I/O interrupts and holds locks. An SRB can run in all these modes. Bill Fairchild Franklin, TN
----- Original Message ----- From: "Itschak Mugzach" <[email protected]> To: [email protected] Sent: Monday, November 4, 2013 12:35:13 AM Subject: Re: Security exposure of zXXP was Re: zIIP simulation That's true. You can't infect files/load modulesqetc. ITschak On Mon, Nov 4, 2013 at 2:15 AM, Jon Perryman <[email protected]> wrote: > I think Itschak is saying that SRB's can't do I/O, therefore they can't > write files to embed a virus or read confidential data. I think he's under > the impression that SRB's can't get access to everything they desire. > > Jon Perryman. > > > > >________________________________ > > From: Ed Jaffe <[email protected]> > > > > > >On 11/3/2013 10:25 AM, Itschak Mugzach wrote: > >> SRB mode is also disabled for IO, so you can't infect other libraries / > files like a virus. > > > >Not sure what you're driving at here. It's true that zIIPs are disabled > for I/O interrupts, but so are most CPs unless you have a "boat load" of > I/O activity. How is that relevant? > > > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
