Messages in this thread |  | | Date | Sat, 29 Jun 1996 17:04:06 -0700 | From | "Leonard N. Zubkoff" <> | Subject | Re: Network performance |
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Date: Sat, 29 Jun 1996 16:18:02 -0600 (CST) From: Aaron Ucko <UCKO@vax1.rockhurst.edu>
>Domain/OS used shared global libraries to provide the user visible >functionality that was not part of the kernel itself. All the normal file >operations went through the global library, which either directed them >through the inherited default I/O Switch operations or to operations >provided in an installed type manager library.
Interesting...how was this made secure? The OS must have implemented shared libs in such a way that library code was privileged but user code wasn't... I don't even want to THINK about statically linked binaries! :-) Reminds me of Hurd, though.
Why does the library code need to be privileged? Read and write can be built out of memory mapping primitives without security problems so long as the kernel implements the proper access rights on the underlying mapped object. Naturally, installing a new type manager required the appropriate access rights itself. As for static linking, the global libraries were *never* statically linked into anything. It just wasn't possible or necessary.
Leonard
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