Re: gnumach RPC: get info about the calling task

[Sergey Bugaev]

On Sun, Oct 17, 2021 at 6:41 PM Joan Lledó <jlledom@mailfence.com> wrote:
> Why the "size" parameter? I'd rather see a new wrapper for
> memory_object_create_proxy() which receives the same params but with the
> address instead of the original pager, which internally gets the pager
> from the address and calls memory_object_create_proxy().

Well, memory_object_create_proxy () also has a size parameter (named
len; also it has a wrong type, should be vm_size_array_t, not
vm_offset_array_t).

In the case of vm_task-backed proxy, it's important to limit how much
of your memory you want to expose through the proxy. You don't want to
expose *all* of your task's memory starting at an address; you want a
region, defined by an (address, size) pair.

> After all, the
> only reason why I need the pager is to send it to
> memory_object_create_proxy() at netfs_impl.c:617 [1]. So why not skip
> one step?

Yes, it'd be nicer if you don't have to create another proxy of the proxy.

Sergey