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>

1 files changed, 3 insertions, 4 deletions

diff --git a/drivers/scsi/fnic/fnic_fcs.c b/drivers/scsi/fnic/fnic_fcs.c
index e3b964b7235a..e72becaad8a5 100644
--- a/drivers/scsi/fnic/fnic_fcs.c
+++ b/drivers/scsi/fnic/fnic_fcs.c
@@ -1000,8 +1000,7 @@ void fnic_eth_send(struct fcoe_ctlr *fip, struct sk_buff *skb)
 
 	if (!fnic->vlan_hw_insert) {
 		eth_hdr = (struct ethhdr *)skb_mac_header(skb);
-		vlan_hdr = (struct vlan_ethhdr *)skb_push(skb,
-				sizeof(*vlan_hdr) - sizeof(*eth_hdr));
+		vlan_hdr = skb_push(skb, sizeof(*vlan_hdr) - sizeof(*eth_hdr));
 		memcpy(vlan_hdr, eth_hdr, 2 * ETH_ALEN);
 		vlan_hdr->h_vlan_proto = htons(ETH_P_8021Q);
 		vlan_hdr->h_vlan_encapsulated_proto = eth_hdr->h_proto;
@@ -1067,7 +1066,7 @@ static int fnic_send_frame(struct fnic *fnic, struct fc_frame *fp)
 
 	if (!fnic->vlan_hw_insert) {
 		eth_hdr_len = sizeof(*vlan_hdr) + sizeof(*fcoe_hdr);
-		vlan_hdr = (struct vlan_ethhdr *)skb_push(skb, eth_hdr_len);
+		vlan_hdr = skb_push(skb, eth_hdr_len);
 		eth_hdr = (struct ethhdr *)vlan_hdr;
 		vlan_hdr->h_vlan_proto = htons(ETH_P_8021Q);
 		vlan_hdr->h_vlan_encapsulated_proto = htons(ETH_P_FCOE);
@@ -1075,7 +1074,7 @@ static int fnic_send_frame(struct fnic *fnic, struct fc_frame *fp)
 		fcoe_hdr = (struct fcoe_hdr *)(vlan_hdr + 1);
 	} else {
 		eth_hdr_len = sizeof(*eth_hdr) + sizeof(*fcoe_hdr);
-		eth_hdr = (struct ethhdr *)skb_push(skb, eth_hdr_len);
+		eth_hdr = skb_push(skb, eth_hdr_len);
 		eth_hdr->h_proto = htons(ETH_P_FCOE);
 		fcoe_hdr = (struct fcoe_hdr *)(eth_hdr + 1);
 	}