networking: make skb_push & __skb_push return void pointers

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

    @@
    expression SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - fn(SKB, LEN)[0]
    + *(u8 *)fn(SKB, LEN)

Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 7 insertions, 7 deletions

diff --git a/drivers/net/usb/gl620a.c b/drivers/net/usb/gl620a.c
index 29276e54bb8b..ba1ce1006c4f 100644
--- a/drivers/net/usb/gl620a.c
+++ b/drivers/net/usb/gl620a.c
@@ -174,7 +174,7 @@ genelink_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 	}
 
 	// attach the packet count to the header
-	packet_count = (__le32 *) skb_push(skb, (4 + 4*1));
+	packet_count = skb_push(skb, (4 + 4 * 1));
 	packet_len = packet_count + 1;
 
 	*packet_count = cpu_to_le32(1);
diff --git a/drivers/net/usb/int51x1.c b/drivers/net/usb/int51x1.c
index 5a43b77a6b9c..be63a829b8fe 100644
--- a/drivers/net/usb/int51x1.c
+++ b/drivers/net/usb/int51x1.c
@@ -106,7 +106,7 @@ static struct sk_buff *int51x1_tx_fixup(struct usbnet *dev,
 	pack_len += need_tail;
 	pack_len &= 0x07ff;
 
-	len = (__le16 *) __skb_push(skb, INT51X1_HEADER_SIZE);
+	len = __skb_push(skb, INT51X1_HEADER_SIZE);
 	*len = cpu_to_le16(pack_len);
 
 	if(need_tail)
diff --git a/drivers/net/usb/kaweth.c b/drivers/net/usb/kaweth.c
index 37fb621fde86..92e4fd29ae44 100644
--- a/drivers/net/usb/kaweth.c
+++ b/drivers/net/usb/kaweth.c
@@ -809,7 +809,7 @@ static netdev_tx_t kaweth_start_xmit(struct sk_buff *skb,
 		return NETDEV_TX_OK;
 	}
 
-	private_header = (__le16 *)__skb_push(skb, 2);
+	private_header = __skb_push(skb, 2);
 	*private_header = cpu_to_le16(skb->len-2);
 	kaweth->tx_skb = skb;
 
diff --git a/drivers/net/usb/lg-vl600.c b/drivers/net/usb/lg-vl600.c
index d633492bf9eb..dbabd7ca5268 100644
--- a/drivers/net/usb/lg-vl600.c
+++ b/drivers/net/usb/lg-vl600.c
@@ -304,7 +304,7 @@ encapsulate:
 	memset(&packet->dummy, 0, sizeof(packet->dummy));
 	packet->len = cpu_to_le32(orig_len);
 
-	frame = (struct vl600_frame_hdr *) skb_push(skb, sizeof(*frame));
+	frame = skb_push(skb, sizeof(*frame));
 	memset(frame, 0, sizeof(*frame));
 	frame->len = cpu_to_le32(full_len);
 	frame->serial = cpu_to_le32(serial++);
diff --git a/drivers/net/usb/net1080.c b/drivers/net/usb/net1080.c
index 861ff45f0b09..be53ff30b7b5 100644
--- a/drivers/net/usb/net1080.c
+++ b/drivers/net/usb/net1080.c
@@ -466,7 +466,7 @@ net1080_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 
 encapsulate:
 	/* header first */
-	header = (struct nc_header *) skb_push(skb, sizeof *header);
+	header = skb_push(skb, sizeof *header);
 	header->hdr_len = cpu_to_le16(sizeof (*header));
 	header->packet_len = cpu_to_le16(len);
 	header->packet_id = cpu_to_le16((u16)dev->xid++);
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index ffd229ec8352..5894e3c9468f 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -101,7 +101,7 @@ static netdev_tx_t qmimux_start_xmit(struct sk_buff *skb, struct net_device *dev
 	unsigned int len = skb->len;
 	struct qmimux_hdr *hdr;
 
-	hdr = (struct qmimux_hdr *)skb_push(skb, sizeof(struct qmimux_hdr));
+	hdr = skb_push(skb, sizeof(struct qmimux_hdr));
 	hdr->pad = 0;
 	hdr->mux_id = priv->mux_id;
 	hdr->pkt_len = cpu_to_be16(len);
diff --git a/drivers/net/usb/rndis_host.c b/drivers/net/usb/rndis_host.c
index e96e2e5673d7..a151f267aebb 100644
--- a/drivers/net/usb/rndis_host.c
+++ b/drivers/net/usb/rndis_host.c
@@ -578,7 +578,7 @@ rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
 	 * packets; Linux minimizes wasted bandwidth through tx queues.
 	 */
 fill:
-	hdr = (void *) __skb_push(skb, sizeof *hdr);
+	hdr = __skb_push(skb, sizeof *hdr);
 	memset(hdr, 0, sizeof *hdr);
 	hdr->msg_type = cpu_to_le32(RNDIS_MSG_PACKET);
 	hdr->msg_len = cpu_to_le32(skb->len);