Constrained file descriptors

[Christian Helmuth]

Hello Johannes,

On Fri, Dec 29, 2017 at 07:37:39PM +0100, Johannes Kliemann wrote:
> before Christmas we chatted about enabling the MMIO session on Linux.
> You said that you know a possibility to create constrained file
> descriptors (in such a way that accesses through this descriptor can
> only access a part of the file). I've done a second search but I
> couldn't find any useful information regarding this topic.
> Do you have any further, more specific, information about how to achieve
> this goal?

I had a chat with Norman and we're not sure if he was referring to
memfd_create() [1] which, unfortunately, does not solve the issue as
it only handles anonymous memory. Maybe adding "android" to the
keywords on your internet search brings up more interesting hits?
Also, uio has solve this issue too, right?

[1] http://man7.org/linux/man-pages/man2/memfd_create.2.html
[2] https://www.kernel.org/doc/html/latest/driver-api/uio-howto.html

Greets
-- 
Christian Helmuth
Genode Labs

https://www.genode-labs.com/ · https://genode.org/
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