xdp: convert to getsockopt_iter

Convert XDP socket's getsockopt implementation to use the new
getsockopt_iter callback with sockopt_t.

Key changes:
- Replace (char __user *optval, int __user *optlen) with sockopt_t *opt
- Use opt->optlen for buffer length (input) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260520-getsock_four-v3-3-b8c0b16b7780@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 5e5786cd9af55afe400479bd37515d548b06aa76..77f8de054a1be96acdb4791e4ae97f3af5164a46 100644 (file)
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -22,6 +22,7 @@
 #include <linux/net.h>
 #include <linux/netdevice.h>
 #include <linux/rculist.h>
+#include <linux/uio.h>
 #include <linux/vmalloc.h>
 
 #include <net/netdev_queues.h>
@@ -1729,7 +1730,7 @@ struct xdp_statistics_v1 {
 };
 
 static int xsk_getsockopt(struct socket *sock, int level, int optname,
-                         char __user *optval, int __user *optlen)
+                         sockopt_t *opt)
 {
        struct sock *sk = sock->sk;
        struct xdp_sock *xs = xdp_sk(sk);
@@ -1738,8 +1739,7 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
        if (level != SOL_XDP)
                return -ENOPROTOOPT;
 
-       if (get_user(len, optlen))
-               return -EFAULT;
+       len = opt->optlen;
        if (len < 0)
                return -EINVAL;
 
@@ -1773,10 +1773,10 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
                stats.tx_invalid_descs = xskq_nb_invalid_descs(xs->tx);
                mutex_unlock(&xs->mutex);
 
-               if (copy_to_user(optval, &stats, stats_size))
-                       return -EFAULT;
-               if (put_user(stats_size, optlen))
+               if (copy_to_iter(&stats, stats_size, &opt->iter_out) !=
+                   stats_size)
                        return -EFAULT;
+               opt->optlen = stats_size;
 
                return 0;
        }
@@ -1825,10 +1825,9 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
                        to_copy = &off_v1;
                }
 
-               if (copy_to_user(optval, to_copy, len))
-                       return -EFAULT;
-               if (put_user(len, optlen))
+               if (copy_to_iter(to_copy, len, &opt->iter_out) != len)
                        return -EFAULT;
+               opt->optlen = len;
 
                return 0;
        }
@@ -1845,10 +1844,9 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
                mutex_unlock(&xs->mutex);
 
                len = sizeof(opts);
-               if (copy_to_user(optval, &opts, len))
-                       return -EFAULT;
-               if (put_user(len, optlen))
+               if (copy_to_iter(&opts, len, &opt->iter_out) != len)
                        return -EFAULT;
+               opt->optlen = len;
 
                return 0;
        }
@@ -1949,7 +1947,7 @@ static const struct proto_ops xsk_proto_ops = {
        .listen         = sock_no_listen,
        .shutdown       = sock_no_shutdown,
        .setsockopt     = xsk_setsockopt,
-       .getsockopt     = xsk_getsockopt,
+       .getsockopt_iter = xsk_getsockopt,
        .sendmsg        = xsk_sendmsg,
        .recvmsg        = xsk_recvmsg,
        .mmap           = xsk_mmap,