net: switch sock_setbindtodevice to sockptr_t

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/core/sock.c

@@ -609,8 +609,7 @@ int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk)
 }
 EXPORT_SYMBOL(sock_bindtoindex);
 
-static int sock_setbindtodevice(struct sock *sk, char __user *optval,
-				int optlen)
+static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
 {
 	int ret = -ENOPROTOOPT;
 #ifdef CONFIG_NETDEVICES
@@ -632,7 +631,7 @@ static int sock_setbindtodevice(struct sock *sk, char __user *optval,
 	memset(devname, 0, sizeof(devname));
 
 	ret = -EFAULT;
-	if (copy_from_user(devname, optval, optlen))
+	if (copy_from_sockptr(devname, optval, optlen))
 		goto out;
 
 	index = 0;
@@ -840,7 +839,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
 	 */
 
 	if (optname == SO_BINDTODEVICE)
-		return sock_setbindtodevice(sk, optval, optlen);
+		return sock_setbindtodevice(sk, USER_SOCKPTR(optval), optlen);
 
 	if (optlen < sizeof(int))
 		return -EINVAL;