Merge tag 'csky-for-linus-5.6-rc3' of git://github.com/c-sky/csky-linux

[linux-2.6-microblaze.git] / drivers / net / wireguard / send.c

diff --git a/drivers/net/wireguard/send.c b/drivers/net/wireguard/send.c
index c132605..7348c10 100644 (file)
--- a/drivers/net/wireguard/send.c
+++ b/drivers/net/wireguard/send.c
@@ -143,16 +143,22 @@ static void keep_key_fresh(struct wg_peer *peer)
 
 static unsigned int calculate_skb_padding(struct sk_buff *skb)
 {
+       unsigned int padded_size, last_unit = skb->len;
+
+       if (unlikely(!PACKET_CB(skb)->mtu))
+               return ALIGN(last_unit, MESSAGE_PADDING_MULTIPLE) - last_unit;
+
        /* We do this modulo business with the MTU, just in case the networking
         * layer gives us a packet that's bigger than the MTU. In that case, we
         * wouldn't want the final subtraction to overflow in the case of the
-        * padded_size being clamped.
+        * padded_size being clamped. Fortunately, that's very rarely the case,
+        * so we optimize for that not happening.
         */
-       unsigned int last_unit = skb->len % PACKET_CB(skb)->mtu;
-       unsigned int padded_size = ALIGN(last_unit, MESSAGE_PADDING_MULTIPLE);
+       if (unlikely(last_unit > PACKET_CB(skb)->mtu))
+               last_unit %= PACKET_CB(skb)->mtu;
 
-       if (padded_size > PACKET_CB(skb)->mtu)
-               padded_size = PACKET_CB(skb)->mtu;
+       padded_size = min(PACKET_CB(skb)->mtu,
+                         ALIGN(last_unit, MESSAGE_PADDING_MULTIPLE));
        return padded_size - last_unit;
 }