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>

5 files changed, 7 insertions, 9 deletions

diff --git a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
index 1880eb6c68f7..7b09e7ddf35e 100644
--- a/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
+++ b/drivers/scsi/cxgbi/cxgb3i/cxgb3i.c
@@ -354,7 +354,7 @@ static inline void make_tx_data_wr(struct cxgbi_sock *csk, struct sk_buff *skb,
 	struct l2t_entry *l2t = csk->l2t;
 
 	skb_reset_transport_header(skb);
-	req = (struct tx_data_wr *)__skb_push(skb, sizeof(*req));
+	req = __skb_push(skb, sizeof(*req));
 	req->wr_hi = htonl(V_WR_OP(FW_WROPCODE_OFLD_TX_DATA) |
 			(req_completion ? F_WR_COMPL : 0));
 	req->wr_lo = htonl(V_WR_TID(csk->tid));
diff --git a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
index 397094b8bad6..5485d68f286a 100644
--- a/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
+++ b/drivers/scsi/cxgbi/cxgb4i/cxgb4i.c
@@ -644,7 +644,7 @@ static inline void make_tx_data_wr(struct cxgbi_sock *csk, struct sk_buff *skb,
 	unsigned int wr_ulp_mode = 0, val;
 	bool imm = is_ofld_imm(skb);
 
-	req = (struct fw_ofld_tx_data_wr *)__skb_push(skb, sizeof(*req));
+	req = __skb_push(skb, sizeof(*req));
 
 	if (imm) {
 		req->op_to_immdlen = htonl(FW_WR_OP_V(FW_OFLD_TX_DATA_WR) |
diff --git a/drivers/scsi/fcoe/fcoe_ctlr.c b/drivers/scsi/fcoe/fcoe_ctlr.c
index e17bdb3adf9e..fff6f1851dc1 100644
--- a/drivers/scsi/fcoe/fcoe_ctlr.c
+++ b/drivers/scsi/fcoe/fcoe_ctlr.c
@@ -626,7 +626,7 @@ static int fcoe_ctlr_encaps(struct fcoe_ctlr *fip, struct fc_lport *lport,
 	fh = (struct fc_frame_header *)skb->data;
 	op = *(u8 *)(fh + 1);
 	dlen = sizeof(struct fip_encaps) + skb->len;	/* len before push */
-	cap = (struct fip_encaps_head *)skb_push(skb, sizeof(*cap));
+	cap = skb_push(skb, sizeof(*cap));
 	memset(cap, 0, sizeof(*cap));
 
 	if (lport->point_to_multipoint) {
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);
 	}
diff --git a/drivers/scsi/qedf/qedf_fip.c b/drivers/scsi/qedf/qedf_fip.c
index e10b91cc3c62..0d4bf70803ae 100644
--- a/drivers/scsi/qedf/qedf_fip.c
+++ b/drivers/scsi/qedf/qedf_fip.c
@@ -125,8 +125,7 @@ void qedf_fip_send(struct fcoe_ctlr *fip, struct sk_buff *skb)
 	sub = fiph->fip_subcode;
 
 	if (!qedf->vlan_hw_insert) {
-		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;