networking: introduce and use skb_put_data()

A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/s390/net/ctcm_fsms.c b/drivers/s390/net/ctcm_fsms.c
index 730d9619400e..e9847ce3860d 100644
--- a/drivers/s390/net/ctcm_fsms.c
+++ b/drivers/s390/net/ctcm_fsms.c
@@ -1279,7 +1279,7 @@ static void ctcmpc_chx_txdone(fsm_instance *fi, int event, void *arg)
 		       __func__, data_space);
 
 	while ((skb = skb_dequeue(&ch->collect_queue))) {
-		memcpy(skb_put(ch->trans_skb, skb->len), skb->data, skb->len);
+		skb_put_data(ch->trans_skb, skb->data, skb->len);
 		p_header = (struct pdu *)
 			(skb_tail_pointer(ch->trans_skb) - skb->len);
 		p_header->pdu_flag = 0x00;
@@ -1431,13 +1431,12 @@ static void ctcmpc_chx_rx(fsm_instance *fi, int event, void *arg)
 			break;
 		case MPCG_STATE_FLOWC:
 		case MPCG_STATE_READY:
-			memcpy(skb_put(new_skb, block_len),
-					       skb->data, block_len);
+			skb_put_data(new_skb, skb->data, block_len);
 			skb_queue_tail(&ch->io_queue, new_skb);
 			tasklet_schedule(&ch->ch_tasklet);
 			break;
 		default:
-			memcpy(skb_put(new_skb, len), skb->data, len);
+			skb_put_data(new_skb, skb->data, len);
 			skb_queue_tail(&ch->io_queue, new_skb);
 			tasklet_hi_schedule(&ch->ch_tasklet);
 			break;