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, 2 insertions, 2 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index a115c0b7a310..5da6f2e9f22e 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -681,7 +681,7 @@ static void push_pseudo_header(struct sk_buff *skb, const char *daddr)
 {
 	struct ipoib_pseudo_header *phdr;
 
-	phdr = (struct ipoib_pseudo_header *)skb_push(skb, sizeof(*phdr));
+	phdr = skb_push(skb, sizeof(*phdr));
 	memcpy(phdr->hwaddr, daddr, INFINIBAND_ALEN);
 }
 
@@ -1129,7 +1129,7 @@ static int ipoib_hard_header(struct sk_buff *skb,
 {
 	struct ipoib_header *header;
 
-	header = (struct ipoib_header *) skb_push(skb, sizeof *header);
+	header = skb_push(skb, sizeof *header);
 
 	header->proto = htons(type);
 	header->reserved = 0;