| Message ID | 20200810122856.5423-1-linmiaohe@huawei.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: eliminate meaningless memcpy to data in pskb_carve_inside_nonlinear() | expand |
Miaohe Lin <linmiaohe@huawei.com> wrote:
> The skb_shared_info part of the data is assigned in the following loop.
Where?
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. > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > net/core/skbuff.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > index 7e2e502ef519..5b983c9472f5 100644 > --- a/net/core/skbuff.c > +++ b/net/core/skbuff.c > @@ -5952,9 +5952,6 @@ 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])); > if (skb_orphan_frags(skb, gfp_mask)) { > kfree(data); > return -ENOMEM; > Reminder : net-next is CLOSED. 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;
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 7e2e502ef519..5b983c9472f5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -5952,9 +5952,6 @@ 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])); if (skb_orphan_frags(skb, gfp_mask)) { kfree(data); return -ENOMEM;
The skb_shared_info part of the data is assigned in the following loop. It is meaningless to do a memcpy here. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- net/core/skbuff.c | 3 --- 1 file changed, 3 deletions(-)