Re: [PATCH] io_uring/net: silence sparse warnings on address space

[Christoph Hellwig <hch@infradead.org>]

On Tue, Jun 20, 2023 at 04:55:05PM -0600, Jens Axboe wrote:
> Rather than assign the user pointer to msghdr->msg_control, assign it
> to msghdr->msg_control_user to make sparse happy. They are in a union
> so the end result is the same, but let's avoid new sparse warnings and
> squash this one.

Te patch looks good, but I think "silence sparse warning" is a horrible
way to write a commit message.  Yes, you're silencing sparse, but sparse
only complains because we have a type mismatch.

So the much better Subject would be something like: 

io_uring/net: use the correct msghdr union member in io_sendmsg_copy_hdr

Use msg_control_user to read the control message in io_sendmsg_copy_hdr
as we expect a user pointer, not the kernel pointer in msg_control.
The end result is the same, but this avoids a sparse addres space
warning.

With that:

Reviewed-by: Christoph Hellwig <hch@lst.de>

(and it's really time we ger the __user and __bitwise annotations
checked by hte actual compiler..)