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>

8 files changed, 14 insertions, 14 deletions

diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index 82471af5553e..f948fc2099d2 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -185,7 +185,7 @@ static void digital_skb_push_dep_sod(struct nfc_digital_dev *ddev,
 	skb->data[0] = skb->len;
 
 	if (ddev->curr_rf_tech == NFC_DIGITAL_RF_TECH_106A)
-		*skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB;
+		*(u8 *)skb_push(skb, sizeof(u8)) = DIGITAL_NFC_DEP_NFCA_SOD_SB;
 }
 
 static int digital_skb_pull_dep_sod(struct nfc_digital_dev *ddev,
diff --git a/net/nfc/digital_technology.c b/net/nfc/digital_technology.c
index fae6d31b377c..492204e440ec 100644
--- a/net/nfc/digital_technology.c
+++ b/net/nfc/digital_technology.c
@@ -828,7 +828,7 @@ int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 	sensf_req->rc = 0;
 	sensf_req->tsn = 0;
 
-	*skb_push(skb, 1) = size + 1;
+	*(u8 *)skb_push(skb, 1) = size + 1;
 
 	if (!DIGITAL_DRV_CAPS_IN_CRC(ddev))
 		digital_skb_add_crc_f(skb);
@@ -1161,7 +1161,7 @@ static int digital_tg_send_sensf_res(struct nfc_digital_dev *ddev,
 		break;
 	}
 
-	*skb_push(skb, sizeof(u8)) = size + 1;
+	*(u8 *)skb_push(skb, sizeof(u8)) = size + 1;
 
 	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
 		digital_skb_add_crc_f(skb);
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c
index 3a0c94590411..7b2bdda1514c 100644
--- a/net/nfc/hci/core.c
+++ b/net/nfc/hci/core.c
@@ -727,7 +727,7 @@ static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
 				break;
 		}
 
-		*skb_push(skb, 1) = 0;	/* CTR, see spec:10.2.2.1 */
+		*(u8 *)skb_push(skb, 1) = 0;	/* CTR, see spec:10.2.2.1 */
 
 		hdev->async_cb_type = HCI_CB_TYPE_TRANSCEIVE;
 		hdev->async_cb = cb;
diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c
index 9ab4a05f086f..5bd4529279f5 100644
--- a/net/nfc/hci/llc_shdlc.c
+++ b/net/nfc/hci/llc_shdlc.c
@@ -160,7 +160,7 @@ static int llc_shdlc_send_s_frame(struct llc_shdlc *shdlc,
 	if (skb == NULL)
 		return -ENOMEM;
 
-	*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr;
+	*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr;
 
 	r = shdlc->xmit_to_drv(shdlc->hdev, skb);
 
@@ -178,7 +178,7 @@ static int llc_shdlc_send_u_frame(struct llc_shdlc *shdlc,
 
 	pr_debug("uframe_modifier=%d\n", uframe_modifier);
 
-	*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier;
+	*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier;
 
 	r = shdlc->xmit_to_drv(shdlc->hdev, skb);
 
@@ -551,8 +551,8 @@ static void llc_shdlc_handle_send_queue(struct llc_shdlc *shdlc)
 
 		skb = skb_dequeue(&shdlc->send_q);
 
-		*skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) |
-				    shdlc->nr;
+		*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) |
+					shdlc->nr;
 
 		pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns,
 			 shdlc->nr);
diff --git a/net/nfc/nci/data.c b/net/nfc/nci/data.c
index 2488d9241f1d..908f25e3773e 100644
--- a/net/nfc/nci/data.c
+++ b/net/nfc/nci/data.c
@@ -81,7 +81,7 @@ static inline void nci_push_data_hdr(struct nci_dev *ndev,
 	struct nci_data_hdr *hdr;
 	int plen = skb->len;
 
-	hdr = (struct nci_data_hdr *) skb_push(skb, NCI_DATA_HDR_SIZE);
+	hdr = skb_push(skb, NCI_DATA_HDR_SIZE);
 	hdr->conn_id = conn_id;
 	hdr->rfu = 0;
 	hdr->plen = plen;
diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index d1119bb35f24..3f93df58d9f1 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -170,7 +170,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
 		return -ENOMEM;
 
 	skb_reserve(skb, NCI_DATA_HDR_SIZE + 2);
-	*skb_push(skb, 1) = data_type;
+	*(u8 *)skb_push(skb, 1) = data_type;
 
 	do {
 		len = conn_info->max_pkt_payload_len;
@@ -184,7 +184,7 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
 			len = conn_info->max_pkt_payload_len - skb->len - 1;
 		}
 
-		*skb_push(skb, 1) = cb;
+		*(u8 *)skb_push(skb, 1) = cb;
 
 		if (len > 0)
 			skb_put_data(skb, data + i, len);
diff --git a/net/nfc/nci/spi.c b/net/nfc/nci/spi.c
index a502a334918a..3b4512731a2f 100644
--- a/net/nfc/nci/spi.c
+++ b/net/nfc/nci/spi.c
@@ -238,8 +238,8 @@ static struct sk_buff *__nci_spi_read(struct nci_spi *nspi)
 		goto receive_error;
 
 	if (nspi->acknowledge_mode == NCI_SPI_CRC_ENABLED) {
-		*skb_push(skb, 1) = resp_hdr[1];
-		*skb_push(skb, 1) = resp_hdr[0];
+		*(u8 *)skb_push(skb, 1) = resp_hdr[1];
+		*(u8 *)skb_push(skb, 1) = resp_hdr[0];
 	}
 
 	return skb;
diff --git a/net/nfc/rawsock.c b/net/nfc/rawsock.c
index e386e6c90b17..e2188deb08dc 100644
--- a/net/nfc/rawsock.c
+++ b/net/nfc/rawsock.c
@@ -142,7 +142,7 @@ error:
 
 static int rawsock_add_header(struct sk_buff *skb)
 {
-	*skb_push(skb, NFC_HEADER_SIZE) = 0;
+	*(u8 *)skb_push(skb, NFC_HEADER_SIZE) = 0;
 
 	return 0;
 }