On Wed, 22 Feb 2006, Jonas Maebe wrote:
On 22 feb 2006, at 11:26, Michael Van Canneyt wrote:
I don't think there are many host OS'es out there which e.g. only run
signed applications. The fact is that for some purposes, none of the
current OS'es "does its job correctly" in that sense. Just use the right
tool for the job, I personally don't understand all this hostility against
managed environments (except as a reaction against claims that they are
always much better than unmanaged environments, but overdoing it in the
other direction isn't going to get the discussion anywhere).
Well, the very idea of a program running in a managed environment which by
itself is also a managed environment seems like a waste of resources.
The environments have different management capabilities. The OS manages the
hardware and provides an interface between the hardware and the software.
These managed environments pure manage software. They don't have a
compatibility scourge to deal with, and therefore can break paradigms which
are widely in use but which are inherently insecure (such as pointers) or
which make programs unverifiable (self-modifying code, data-in-code and
code-in data, code flow which is impossible to determine etc).
This is all true, but none of these cannot be handled by the OS.
No-one said that an OS has to apply the same rules to user-space
programs and to device drivers. In fact, most don't...
Secondly, too many links in the chain makes it easier for the chain to
break...
I don't think a managed environment is easier to break than in case you try
to stuff all those things in an already existing environments.
It's not about breaking in.
But 2 cooperating programs break down easier than 1.
The advantage of running 'signed' applications also eludes me. Even so,
provided you really want that, you could easily integrate that in the OS,
without having a new managed environment...
Then you have to integrate it in every OS, bolting it on on structures which
were never designed for such things.
Now you must rewrite your engine on each OS. To do that, you must build some
kind of OS-asbtraction layer if you don't want to re-implement from scratch,
so, it's the same thing as far as I can see...
Anyway, it's not really worth the discussion. It exists, people use it...
Michael.
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/mailman/listinfo/fpc-pascal
