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>

3 files changed, 6 insertions, 7 deletions

diff --git a/drivers/nfc/nfcmrvl/fw_dnld.c b/drivers/nfc/nfcmrvl/fw_dnld.c
index c38bdd6a5a82..7c710458568e 100644
--- a/drivers/nfc/nfcmrvl/fw_dnld.c
+++ b/drivers/nfc/nfcmrvl/fw_dnld.c
@@ -324,10 +324,9 @@ static int process_state_fw_dnld(struct nfcmrvl_private *priv,
 			out_skb = alloc_lc_skb(priv, priv->fw_dnld.chunk_len);
 			if (!out_skb)
 				return -ENOMEM;
-			memcpy(skb_put(out_skb, priv->fw_dnld.chunk_len),
-			       ((uint8_t *)priv->fw_dnld.fw->data) +
-			       priv->fw_dnld.offset,
-			       priv->fw_dnld.chunk_len);
+			skb_put_data(out_skb,
+				     ((uint8_t *)priv->fw_dnld.fw->data) + priv->fw_dnld.offset,
+				     priv->fw_dnld.chunk_len);
 			nci_send_frame(priv->ndev, out_skb);
 			priv->fw_dnld.substate = SUBSTATE_WAIT_DATA_CREDIT;
 		}
diff --git a/drivers/nfc/nfcmrvl/i2c.c b/drivers/nfc/nfcmrvl/i2c.c
index 78b7aa835c81..ffec103702f1 100644
--- a/drivers/nfc/nfcmrvl/i2c.c
+++ b/drivers/nfc/nfcmrvl/i2c.c
@@ -60,7 +60,7 @@ static int nfcmrvl_i2c_read(struct nfcmrvl_i2c_drv_data *drv_data,
 		return -ENOMEM;
 
 	/* Copy NCI header into the SKB */
-	memcpy(skb_put(*skb, NCI_CTRL_HDR_SIZE), &nci_hdr, NCI_CTRL_HDR_SIZE);
+	skb_put_data(*skb, &nci_hdr, NCI_CTRL_HDR_SIZE);
 
 	if (nci_hdr.plen) {
 		/* Read the NCI payload */
diff --git a/drivers/nfc/nfcmrvl/usb.c b/drivers/nfc/nfcmrvl/usb.c
index 585a0f20835b..699aa9d16575 100644
--- a/drivers/nfc/nfcmrvl/usb.c
+++ b/drivers/nfc/nfcmrvl/usb.c
@@ -83,8 +83,8 @@ static void nfcmrvl_bulk_complete(struct urb *urb)
 		if (!skb) {
 			nfc_err(&drv_data->udev->dev, "failed to alloc mem\n");
 		} else {
-			memcpy(skb_put(skb, urb->actual_length),
-			       urb->transfer_buffer, urb->actual_length);
+			skb_put_data(skb, urb->transfer_buffer,
+				     urb->actual_length);
 			if (nfcmrvl_nci_recv_frame(drv_data->priv, skb) < 0)
 				nfc_err(&drv_data->udev->dev,
 					"corrupted Rx packet\n");