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, 15 insertions, 15 deletions

diff --git a/drivers/nfc/st21nfca/dep.c b/drivers/nfc/st21nfca/dep.c
index ada7b114b6c1..fd08be2917e6 100644
--- a/drivers/nfc/st21nfca/dep.c
+++ b/drivers/nfc/st21nfca/dep.c
@@ -315,10 +315,10 @@ int st21nfca_tm_send_dep_res(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 	int r;
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 
-	*skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
-	*skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_RES;
-	*skb_push(skb, 1) = ST21NFCA_NFCIP1_RES;
-	*skb_push(skb, 1) = skb->len;
+	*(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
+	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_RES;
+	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_RES;
+	*(u8 *)skb_push(skb, 1) = skb->len;
 
 	r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
 			ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
@@ -466,7 +466,7 @@ static void st21nfca_im_send_psl_req(struct nfc_hci_dev *hdev, u8 did, u8 bsi,
 	psl_req->brs = (0x30 & bsi << 4) | (bri & 0x03);
 	psl_req->fsl = lri;
 
-	*skb_push(skb, 1) = info->dep_info.to | 0x10;
+	*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
 
 	st21nfca_im_send_pdu(info, skb);
 }
@@ -568,7 +568,7 @@ int st21nfca_im_send_atr_req(struct nfc_hci_dev *hdev, u8 *gb, size_t gb_len)
 	}
 	atr_req->length = sizeof(struct st21nfca_atr_req) + hdev->gb_len;
 
-	*skb_push(skb, 1) = info->dep_info.to | 0x10; /* timeout */
+	*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10; /* timeout */
 
 	info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
 	info->async_cb_context = info;
@@ -629,10 +629,10 @@ static void st21nfca_im_recv_dep_res_cb(void *context, struct sk_buff *skb,
 		case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
 			pr_err("Received a SUPERVISOR PDU\n");
 			skb_pull(skb, size);
-			*skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
-			*skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
-			*skb_push(skb, 1) = skb->len;
-			*skb_push(skb, 1) = info->dep_info.to | 0x10;
+			*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
+			*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
+			*(u8 *)skb_push(skb, 1) = skb->len;
+			*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
 
 			st21nfca_im_send_pdu(info, skb);
 			break;
@@ -655,12 +655,12 @@ int st21nfca_im_send_dep_req(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 	info->async_cb_context = info;
 	info->async_cb = st21nfca_im_recv_dep_res_cb;
 
-	*skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
-	*skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
-	*skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
-	*skb_push(skb, 1) = skb->len;
+	*(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
+	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
+	*(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
+	*(u8 *)skb_push(skb, 1) = skb->len;
 
-	*skb_push(skb, 1) = info->dep_info.to | 0x10;
+	*(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;
 
 	return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
 				      ST21NFCA_WR_XCHG_DATA,