net: add skb frag size accessors

To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.

Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c
index 5dcd5be03f31..ee5da9293ce0 100644
--- a/drivers/net/ethernet/realtek/8139cp.c
+++ b/drivers/net/ethernet/realtek/8139cp.c
@@ -777,12 +777,12 @@ static netdev_tx_t cp_start_xmit (struct sk_buff *skb,
                 entry = NEXT_TX(entry);
 
                 for (frag = 0; frag < skb_shinfo(skb)->nr_frags; frag++) {
-                        skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];
+                        const skb_frag_t *this_frag = &skb_shinfo(skb)->frags[frag];
                         u32 len;
                         u32 ctrl;
                         dma_addr_t mapping;
 
-                        len = this_frag->size;
+                        len = skb_frag_size(this_frag);
                         mapping = dma_map_single(&cp->pdev->dev,
                                                  skb_frag_address(this_frag),
                                                  len, PCI_DMA_TODEVICE);