On 8/27/21 11:18 PM, Paul Boddie wrote:
On Friday, 27 August 2021 09:20:35 CEST Jakub Jermář wrote:
On 8/27/21 1:45 AM, Paul Boddie wrote:
Anyway, if anyone has any insight into why the attach operation behaviour
is different, I would very much appreciate it!
This behavior was introduced by the following commit in 2019:
https://github.com/kernkonzept/l4re-core/commit/81edd6119c45be6f1448a5535b13
78fbc9ce89b9
New dataspace and region map APIs
The new APIs allow 64bit offsets and size of dataspaces also on 32bit
architectures. And have a clean and type-safe dataspace flags and
region flags model including execute rights and the possibility of
execute-only pages and so on.
Change-Id: I77273a5bb93c9891bca4f848c9b17db332b1b72a
That might seem like a while ago, but I put off migrating to the GitHub
repositories for some time, partly due to issues I was having with my
increasingly ancient system (it wasn't reliably computing SHA1 digests and
thus Git was very unhappy), partly due to inertia and having a stable code
base to work with, although I'm obviously having to catch up now.
In general, you must specify the access rights of the attached region
explicitly now, otherwise the rights will be --- (empty) and it will not
be possible to access the region. Previously the default was RW access.
Is this to expose the rights more obviously to the client, make it "promise"
to only access pages in a certain way, and to save the region manager the
trouble of sending requests to the dataspace that will only end up being
refused?
This was more like we added support for non-executable data mappings and
while we were at it we also used that opportunity to fix the interface
systematically. For example, the flags now have each their own type.
Before they were all unsigned int's or something like that and so it was
easy to pass a constant of a wrong type around and not be yelled at by
the compiler.
Cheers,
Jakub
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