Messages in this thread | | | From | linmiaohe <> | Subject | Re: [PATCH] net: eliminate meaningless memcpy to data in pskb_carve_inside_nonlinear() | Date | Tue, 11 Aug 2020 12:10:49 +0000 |
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Eric Dumazet <eric.dumazet@gmail.com> wrote: > On 8/10/20 5:28 AM, Miaohe Lin wrote: >> The skb_shared_info part of the data is assigned in the following >> loop. It is meaningless to do a memcpy here. >> > >Reminder : net-next is CLOSED. >
Thanks for your remind. I would wait for it open.
>This is not correct. We still have to copy _something_ > >Something like : > >diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 2828f6d5ba898a5e50ccce45589bf1370e474b0f..1c0519426c7ba4b04377fc8054c4223c135879ab 100644 >--- a/net/core/skbuff.c >+++ b/net/core/skbuff.c >@@ -5953,8 +5953,8 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, > size = SKB_WITH_OVERHEAD(ksize(data)); > > memcpy((struct skb_shared_info *)(data + size), >- skb_shinfo(skb), offsetof(struct skb_shared_info, >- frags[skb_shinfo(skb)->nr_frags])); >+ skb_shinfo(skb), offsetof(struct skb_shared_info, >+ frags[0])); >+ > if (skb_orphan_frags(skb, gfp_mask)) { > kfree(data); > return -ENOMEM; >
This looks good. Will send a patch v2 soon. May I add a suggested-by tag of you ? Many thanks.
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