Re: [PATCH] Revert "net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends"

[Eric Dumazet]

On 06/17/2018 03:27 AM, Andreas Schwab wrote:

> 
> That doesn't change anything.

OK, thanks !

Oh this is silly, please try :

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c642304f178ce0a4e1358d59e45032a39f76fb3f..54dd9c18ecad817812898d6f335e1794a07dabbe 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1845,10 +1845,9 @@ EXPORT_SYMBOL(___pskb_trim);
 int pskb_trim_rcsum_slow(struct sk_buff *skb, unsigned int len)
 {
        if (skb->ip_summed == CHECKSUM_COMPLETE) {
-               int delta = skb->len - len;
+               __wsum csumdiff = skb_checksum(skb, len, skb->len - len, 0);
 
-               skb->csum = csum_sub(skb->csum,
-                                    skb_checksum(skb, len, delta, 0));
+               skb->csum = csum_block_sub(skb->csum, csumdiff, len);
        }
        return __pskb_trim(skb, len);
 }