Subject: Re: [PATCH net-next v3 0/4] net: move .getsockopt away from __user buffers (update 1)

From: Breno Leitao <[email-masked]>
Date: Fri, 5 Jun 2026 05:25:21 -0700

On Wed, Apr 08, 2026 at 03:30:28AM -0700, Breno Leitao wrote:
> Currently, the .getsockopt callback requires __user pointers:
> 
>   int (*getsockopt)(struct socket *sock, int level,
>                     int optname, char __user *optval, int __user *optlen);
> 
> This prevents kernel callers (io_uring, BPF) from using getsockopt on
> levels other than SOL_SOCKET, since they pass kernel pointers.
> 
> Following Linus' suggestion [0], this series introduces sockopt_t, a
> type-safe wrapper around iov_iter, and a getsockopt_iter callback that
> works with both user and kernel buffers. AF_PACKET and CAN raw are
> converted as initial users, with selftests covering the trickiest
> conversion patterns.

Quick update on this effort.

All proto_ops users have been converted to getsockopt_iter and submitted.

Most conversions are already in linux-next. Three remain:

1) rds: Under review
   https://lore.kernel.org/all/[email-masked]/

2) smc: Submitted today. This is only limited to UBUF right now
   https://lore.kernel.org/all/[email-masked]/

3) CAN drivers: Reviewed and acked, pending Marc's merge
   https://lore.kernel.org/all/[email-masked]/

Once these are merged, I'll rename getsockopt_iter to getsockopt and
remove the legacy path.

Next, I'll convert struct proto the same way to eliminate the remaining
userspace optlen/optval pointers.

After that, io_uring getsockopt operations will be unblocked.