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>

3 files changed, 9 insertions, 9 deletions

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 1301a8786d8d..cdb5c1a7481e 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -332,7 +332,7 @@ void hci_send_to_monitor(struct hci_dev *hdev, struct sk_buff *skb)
                 return;
 
         /* Put header before the data */
-        hdr = (void *)skb_push(skb_copy, HCI_MON_HDR_SIZE);
+        hdr = skb_push(skb_copy, HCI_MON_HDR_SIZE);
         hdr->opcode = opcode;
         hdr->index = cpu_to_le16(hdev->id);
         hdr->len = cpu_to_le16(skb->len);
@@ -383,7 +383,7 @@ void hci_send_monitor_ctrl_event(struct hci_dev *hdev, u16 event,
 
                 skb->tstamp = tstamp;
 
-                hdr = (void *)skb_push(skb, HCI_MON_HDR_SIZE);
+                hdr = skb_push(skb, HCI_MON_HDR_SIZE);
                 hdr->opcode = cpu_to_le16(HCI_MON_CTRL_EVENT);
                 hdr->index = index;
                 hdr->len = cpu_to_le16(skb->len - HCI_MON_HDR_SIZE);
@@ -467,7 +467,7 @@ static struct sk_buff *create_monitor_event(struct hci_dev *hdev, int event)
 
         __net_timestamp(skb);
 
-        hdr = (void *)skb_push(skb, HCI_MON_HDR_SIZE);
+        hdr = skb_push(skb, HCI_MON_HDR_SIZE);
         hdr->opcode = opcode;
         hdr->index = cpu_to_le16(hdev->id);
         hdr->len = cpu_to_le16(skb->len - HCI_MON_HDR_SIZE);
@@ -522,7 +522,7 @@ static struct sk_buff *create_monitor_ctrl_open(struct sock *sk)
 
         __net_timestamp(skb);
 
-        hdr = (void *)skb_push(skb, HCI_MON_HDR_SIZE);
+        hdr = skb_push(skb, HCI_MON_HDR_SIZE);
         hdr->opcode = cpu_to_le16(HCI_MON_CTRL_OPEN);
         if (hci_pi(sk)->hdev)
                 hdr->index = cpu_to_le16(hci_pi(sk)->hdev->id);
@@ -560,7 +560,7 @@ static struct sk_buff *create_monitor_ctrl_close(struct sock *sk)
 
         __net_timestamp(skb);
 
-        hdr = (void *)skb_push(skb, HCI_MON_HDR_SIZE);
+        hdr = skb_push(skb, HCI_MON_HDR_SIZE);
         hdr->opcode = cpu_to_le16(HCI_MON_CTRL_CLOSE);
         if (hci_pi(sk)->hdev)
                 hdr->index = cpu_to_le16(hci_pi(sk)->hdev->id);
@@ -590,7 +590,7 @@ static struct sk_buff *create_monitor_ctrl_command(struct sock *sk, u16 index,
 
         __net_timestamp(skb);
 
-        hdr = (void *)skb_push(skb, HCI_MON_HDR_SIZE);
+        hdr = skb_push(skb, HCI_MON_HDR_SIZE);
         hdr->opcode = cpu_to_le16(HCI_MON_CTRL_COMMAND);
         hdr->index = cpu_to_le16(index);
         hdr->len = cpu_to_le16(skb->len - HCI_MON_HDR_SIZE);
diff --git a/net/bluetooth/mgmt_util.c b/net/bluetooth/mgmt_util.c
index d057113e0d4b..0d0a6d77b9e8 100644
--- a/net/bluetooth/mgmt_util.c
+++ b/net/bluetooth/mgmt_util.c
@@ -48,7 +48,7 @@ static struct sk_buff *create_monitor_ctrl_event(__le16 index, u32 cookie,
 
         __net_timestamp(skb);
 
-        hdr = (void *)skb_push(skb, HCI_MON_HDR_SIZE);
+        hdr = skb_push(skb, HCI_MON_HDR_SIZE);
         hdr->opcode = cpu_to_le16(HCI_MON_CTRL_EVENT);
         hdr->index = index;
         hdr->len = cpu_to_le16(skb->len - HCI_MON_HDR_SIZE);
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index 1a9b906c5a35..4a0b41d75c84 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -1149,10 +1149,10 @@ static void rfcomm_make_uih(struct sk_buff *skb, u8 addr)
         u8 *crc;
 
         if (len > 127) {
-                hdr = (void *) skb_push(skb, 4);
+                hdr = skb_push(skb, 4);
                 put_unaligned(cpu_to_le16(__len16(len)), (__le16 *) &hdr->len);
         } else {
-                hdr = (void *) skb_push(skb, 3);
+                hdr = skb_push(skb, 3);
                 hdr->len = __len8(len);
         }
         hdr->addr = addr;