Re: [RESEND RFC PATCH 0/5] Remote mapping

[Florian Weimer <fw@deneb.enyo.de>]

* Adalbert Lazăr:

>>> - the control plane accepts three ioctls
>>>
>>> PIDFD_MEM_MAP takes a struct like
>>>
>>>     struct pidfd_mem_map {
>>>          uint64_t address;
>>>          off_t offset;
>>>          off_t size;
>>>          int flags;
>>>          int padding[7];
>>>     }
>>>
>>> After this is done, the memory access fd can be mmap-ed at range
>>> [offset,
>>> offset+size), and it will read memory from range [address,
>>> address+size) of the target descriptor.
>>>
>>> PIDFD_MEM_UNMAP takes a struct like
>>>
>>>     struct pidfd_mem_unmap {
>>>          off_t offset;
>>>          off_t size;
>>>     }
>>>
>>> and unmaps the corresponding range of course.

off_t depends on preprocessor macros (_FILE_OFFSET_BITS), so these
types should be uint64_t, too.

I'm not sure what the advantage is of returning separate file
descriptors, and nit operating directly on the pidfd.