Breno Leitao wrote:

Add a helper that initializes a user-backed sockopt_t from the (optval,
optlen) __user pair passed to a getsockopt() callback.

It is used by transitional __user getsockopt wrappers while the
proto-layer getsockopt callbacks are converted to take a sockopt_t, and
is removed once the conversion is complete.

The goal is to help to convert leafs. Example:

 sock_common_getsockopt(... char __user *optval, int __user *optlen)
      → udp_getsockopt(sk, level, optname, optval__user, optlen__user)
               → udp_lib_getsockopt(sk, level, optname, &opt)   /* needs a sockopt_t */

Signed-off-by: Breno Leitao <leitao@debian.org>

Acked-by: Willem de Bruijn <willemb@google.com>