Re: [PATCH v2 1/4] rust: iov: add iov_iter abstractions for ITER_SOURCE

[Andreas Hindborg <a.hindborg@kernel.org>]

"Alice Ryhl" <aliceryhl@google.com> writes:

> On Wed, Jul 09, 2025 at 07:05:01PM +0200, Andreas Hindborg wrote:
>> "Alice Ryhl" <aliceryhl@google.com> writes:
>>
>> > On Wed, Jul 09, 2025 at 01:56:37PM +0200, Andreas Hindborg wrote:
>> >> "Alice Ryhl" <aliceryhl@google.com> writes:
>> >>
>> >> > On Tue, Jul 08, 2025 at 04:45:14PM +0200, Andreas Hindborg wrote:
>> >> >> "Alice Ryhl" <aliceryhl@google.com> writes:
> The iov_iter type is like a giant enum with a bunch of different
> implementations. Some implementations just read from a simple kernel
> buffer that must, of course, be mapped. Some implementations traverse
> complex data structures and stitch the data together from multiple
> buffers. Other implementations map the data into memory on-demand inside
> the copy_from_iter call, without requiring it to be mapped at other
> times. And finally, some implementations perform IO by reading from
> userspace, in which case it's valid for the userspace pointer to be
> *literally any 64-bit integer*. If the address is dangling, that's
> caught inside the call to copy_from_iter and is not a safety issue.

At any rate, this is a very informative paragraph. It would be great if
you could have this information in the documentation for this type.


Best regards,
Andreas Hindborg