networking: add and use skb_put_u8()

Joe and Bjørn suggested that it'd be nicer to not have the
cast in the fairly common case of doing
	*(u8 *)skb_put(skb, 1) = c;

Add skb_put_u8() for this case, and use it across the code,
using the following spatch:

    @@
    expression SKB, C, S;
    typedef u8;
    identifier fn = {skb_put};
    fresh identifier fn2 = fn ## "_u8";
    @@
    - *(u8 *)fn(SKB, S) = C;
    + fn2(SKB, C);

Note that due to the "S", the spatch isn't perfect, it should
have checked that S is 1, but there's also places that use a
sizeof expression like sizeof(var) or sizeof(u8) etc. Turns
out that nobody ever did something like
	*(u8 *)skb_put(skb, 2) = c;

which would be wrong anyway since the second byte wouldn't be
initialized.

Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

8 files changed, 18 insertions, 18 deletions

diff --git a/net/nfc/digital_core.c b/net/nfc/digital_core.c
index fec47a7d0092..ebeace7a8278 100644
--- a/net/nfc/digital_core.c
+++ b/net/nfc/digital_core.c
@@ -74,8 +74,8 @@ void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init,
 	if (msb_first)
 		crc = __fswab16(crc);
 
-	*(u8 *)skb_put(skb, 1) = crc & 0xFF;
-	*(u8 *)skb_put(skb, 1) = (crc >> 8) & 0xFF;
+	skb_put_u8(skb, crc & 0xFF);
+	skb_put_u8(skb, (crc >> 8) & 0xFF);
 }
 
 int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func,
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index f948fc2099d2..74ccc2dd79d0 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -654,7 +654,7 @@ static int digital_in_send_rtox(struct nfc_digital_dev *ddev,
 	if (!skb)
 		return -ENOMEM;
 
-	*(u8 *)skb_put(skb, 1) = rtox;
+	skb_put_u8(skb, rtox);
 
 	skb_push(skb, sizeof(struct digital_dep_req_res));
 
diff --git a/net/nfc/digital_technology.c b/net/nfc/digital_technology.c
index 492204e440ec..3cc3448da524 100644
--- a/net/nfc/digital_technology.c
+++ b/net/nfc/digital_technology.c
@@ -266,8 +266,8 @@ static int digital_in_send_rats(struct nfc_digital_dev *ddev,
 	if (!skb)
 		return -ENOMEM;
 
-	*(u8 *)skb_put(skb, 1) = DIGITAL_RATS_BYTE1;
-	*(u8 *)skb_put(skb, 1) = DIGITAL_RATS_PARAM;
+	skb_put_u8(skb, DIGITAL_RATS_BYTE1);
+	skb_put_u8(skb, DIGITAL_RATS_PARAM);
 
 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_ats,
 				 target);
@@ -470,8 +470,8 @@ static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
 	else
 		sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;
 
-	*(u8 *)skb_put(skb, sizeof(u8)) = sel_cmd;
-	*(u8 *)skb_put(skb, sizeof(u8)) = DIGITAL_SDD_REQ_SEL_PAR;
+	skb_put_u8(skb, sel_cmd);
+	skb_put_u8(skb, DIGITAL_SDD_REQ_SEL_PAR);
 
 	return digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
 				   target);
@@ -541,7 +541,7 @@ int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
 	if (!skb)
 		return -ENOMEM;
 
-	*(u8 *)skb_put(skb, sizeof(u8)) = DIGITAL_CMD_SENS_REQ;
+	skb_put_u8(skb, DIGITAL_CMD_SENS_REQ);
 
 	rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
 	if (rc)
@@ -937,7 +937,7 @@ static int digital_tg_send_sel_res(struct nfc_digital_dev *ddev)
 	if (!skb)
 		return -ENOMEM;
 
-	*(u8 *)skb_put(skb, 1) = DIGITAL_SEL_RES_NFC_DEP;
+	skb_put_u8(skb, DIGITAL_SEL_RES_NFC_DEP);
 
 	if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
 		digital_skb_add_crc_a(skb);
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c
index 7b2bdda1514c..b740fef0acc5 100644
--- a/net/nfc/hci/core.c
+++ b/net/nfc/hci/core.c
@@ -874,7 +874,7 @@ static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 			return;
 		}
 
-		*(u8 *)skb_put(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN) = pipe;
+		skb_put_u8(hcp_skb, pipe);
 
 		skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
 			msg_len = frag_skb->len - NFC_HCI_HCP_PACKET_HEADER_LEN;
diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c
index 5bd4529279f5..17e59a009ce6 100644
--- a/net/nfc/hci/llc_shdlc.c
+++ b/net/nfc/hci/llc_shdlc.c
@@ -382,8 +382,8 @@ static int llc_shdlc_connect_initiate(struct llc_shdlc *shdlc)
 	if (skb == NULL)
 		return -ENOMEM;
 
-	*(u8 *)skb_put(skb, 1) = SHDLC_MAX_WINDOW;
-	*(u8 *)skb_put(skb, 1) = SHDLC_SREJ_SUPPORT ? 1 : 0;
+	skb_put_u8(skb, SHDLC_MAX_WINDOW);
+	skb_put_u8(skb, SHDLC_SREJ_SUPPORT ? 1 : 0);
 
 	return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET);
 }
diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index 3f93df58d9f1..ddfc52ac1f9b 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -472,7 +472,7 @@ void nci_hci_data_received_cb(void *context,
 			return;
 		}
 
-		*(u8 *)skb_put(hcp_skb, NCI_HCI_HCP_PACKET_HEADER_LEN) = pipe;
+		skb_put_u8(hcp_skb, pipe);
 
 		skb_queue_walk(&ndev->hci_dev->rx_hcp_frags, frag_skb) {
 			msg_len = frag_skb->len - NCI_HCI_HCP_PACKET_HEADER_LEN;
diff --git a/net/nfc/nci/spi.c b/net/nfc/nci/spi.c
index 3b4512731a2f..452f4c16b7a9 100644
--- a/net/nfc/nci/spi.c
+++ b/net/nfc/nci/spi.c
@@ -86,8 +86,8 @@ int nci_spi_send(struct nci_spi *nspi,
 		u16 crc;
 
 		crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
-		*(u8 *)skb_put(skb, 1) = crc >> 8;
-		*(u8 *)skb_put(skb, 1) = crc & 0xFF;
+		skb_put_u8(skb, crc >> 8);
+		skb_put_u8(skb, crc & 0xFF);
 	}
 
 	if (write_handshake_completion)	{
@@ -172,8 +172,8 @@ static int send_acknowledge(struct nci_spi *nspi, u8 acknowledge)
 	hdr[3] = 0;
 
 	crc = crc_ccitt(CRC_INIT, skb->data, skb->len);
-	*(u8 *)skb_put(skb, 1) = crc >> 8;
-	*(u8 *)skb_put(skb, 1) = crc & 0xFF;
+	skb_put_u8(skb, crc >> 8);
+	skb_put_u8(skb, crc & 0xFF);
 
 	ret = __nci_spi_send(nspi, skb, 0);
 
diff --git a/net/nfc/nci/uart.c b/net/nfc/nci/uart.c
index 442f8eadfc76..8d104c1db628 100644
--- a/net/nfc/nci/uart.c
+++ b/net/nfc/nci/uart.c
@@ -355,7 +355,7 @@ static int nci_uart_default_recv_buf(struct nci_uart *nu, const u8 *data,
 
 		/* Eat byte after byte till full packet header is received */
 		if (nu->rx_skb->len < NCI_CTRL_HDR_SIZE) {
-			*(u8 *)skb_put(nu->rx_skb, 1) = *data++;
+			skb_put_u8(nu->rx_skb, *data++);
 			--count;
 			continue;
 		}