Hi, On Mon, Aug 29, 2016 at 11:15:48AM +0200, Richard Braun wrote:
> OK, this comes from the fact that io_map directly provides memory > objects indeed... Do we actually want to pass them around ? How > come calls like memory_object_init (specifically meant to be used > between the kernel and the pager) can be made from any client ? [...] > If we consider Unix as a reference, then the map call uses a file > descriptor. It's equivalent to a memory object because the translation > is done privately in the kernel, but we could also change the > mapping interface to provide some proxy object to the client, > which could be thought of as an unprivileged memory object. [...] > The changes involved here are heavy, which is one reason we'd want > to avoid them. Note that we already have proxy memory objects is gnumach. (At least the Debian variant -- don't know whether this ever went upstream.) It currently only implements restrictions on write access (with Marcus' original patch), and for offset/size (with my additions); but I suspect it should be easy to also add restrictions on the management RPCs? Note though that I never fully understood how the memory object management protocol works and is used -- so no idea how that would affect the Hurd as a whole... -antrik-
