net: Document the kernel_recvmsg() function

Signed-off-by: Martin Lucina <mato@kotelna.sk>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/socket.c

@@ -732,6 +732,21 @@ static int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
 	return ret;
 }
 
+/**
+ * kernel_recvmsg - Receive a message from a socket (kernel space)
+ * @sock:       The socket to receive the message from
+ * @msg:        Received message
+ * @vec:        Input s/g array for message data
+ * @num:        Size of input s/g array
+ * @size:       Number of bytes to read
+ * @flags:      Message flags (MSG_DONTWAIT, etc...)
+ *
+ * On return the msg structure contains the scatter/gather array passed in the
+ * vec argument. The array is modified so that it consists of the unfilled
+ * portion of the original array.
+ *
+ * The returned value is the total number of bytes received, or an error.
+ */
 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
 		   struct kvec *vec, size_t num, size_t size, int flags)
 {