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Re: proxy memory objects
From: |
Thomas Bushnell, BSG |
Subject: |
Re: proxy memory objects |
Date: |
21 Nov 2002 11:37:00 -0800 |
User-agent: |
Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 |
Marcus Brinkmann <address@hidden> writes:
> On Wed, Nov 20, 2002 at 09:49:29PM -0800, Thomas Bushnell, BSG wrote:
> > I don't think this makes sense. What task?
>
> Yeah, I know that this was bogus, too. But we have to send it somewhere.
> Maybe it should be mach_host_self to specify the kernel which creates and
> holds the proxy memory object.
>
> > I think we should send it to the memory object, that's the only thing
> > that makes sense.
>
> I agree that this is ok, if you want that additional level of indirection.
I think this is right, because I think it's clearly what the *right
thing* will do. In fact, the kernel doesn't actually need to be
involved with proxy objects *at all*! Oh geez, now that I see this,
it's all so clear.
So the idea is to send a message to the memory object saying "give me
a restricted clone of yourself". Right now, we will implement this
with a hack: a special call to the kernel that returns a special fake
memory object which implements the restriction implicitly at vm_map
time.
And the correct implementation will be for the pager itself in a
separate library, or with the aid of a helper process, to provide the
restricted clone.
> > *THEN* the memory object should have a special hack call to the
> > kernel--to the memory object control port--that creates the actual
> > proxy object.
>
> This was the first thought I had when I realized that the memobj RPC
> doesn't go the kernel. But the memory object control port doesn't exist
> before the first mapping is established. It is for controlling a memory
> object that is actually used by the kernel. The memory objct we have
> created is probably not used until we gave out the proxy object.
> Or did I misunderstood that?
Yes, you're right about that. Since asking the kernel for the clone
is a hack anyhow, it doesn't much matter what interface we use to get
it.
- proxy memory objects, Marcus Brinkmann, 2002/11/19
- Re: proxy memory objects, Marcus Brinkmann, 2002/11/19
- Re: proxy memory objects, Thomas Bushnell, BSG, 2002/11/21
- Re: proxy memory objects, Marcus Brinkmann, 2002/11/21
- Re: proxy memory objects,
Thomas Bushnell, BSG <=
- Re: proxy memory objects, Marcus Brinkmann, 2002/11/21
- Re: proxy memory objects, Thomas Bushnell, BSG, 2002/11/21
- Re: proxy memory objects, Marcus Brinkmann, 2002/11/22
- Re: proxy memory objects, Thomas Bushnell, BSG, 2002/11/22
Re: proxy memory objects, Marcus Brinkmann, 2002/11/20