From de77b966ce8adcb4c58d50e2f087320d5479812a Mon Sep 17 00:00:00 2001
From: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Date: Sun, 18 Jun 2017 22:48:17 +0800
Subject: net: introduce __skb_put_[zero, data, u8]

follow Johannes Berg, semantic patch file as below,
@@
identifier p, p2;
expression len;
expression skb;
type t, t2;
@@
(
-p = __skb_put(skb, len);
+p = __skb_put_zero(skb, len);
|
-p = (t)__skb_put(skb, len);
+p = __skb_put_zero(skb, len);
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, len);
|
-memset(p, 0, len);
)

@@
identifier p;
expression len;
expression skb;
type t;
@@
(
-t p = __skb_put(skb, len);
+t p = __skb_put_zero(skb, len);
)
... when != p
(
-memset(p, 0, len);
)

@@
type t, t2;
identifier p, p2;
expression skb;
@@
t *p;
...
(
-p = __skb_put(skb, sizeof(t));
+p = __skb_put_zero(skb, sizeof(t));
|
-p = (t *)__skb_put(skb, sizeof(t));
+p = __skb_put_zero(skb, sizeof(t));
)
... when != p
(
p2 = (t2)p;
-memset(p2, 0, sizeof(*p));
|
-memset(p, 0, sizeof(*p));
)

@@
expression skb, len;
@@
-memset(__skb_put(skb, len), 0, len);
+__skb_put_zero(skb, len);

@@
expression skb, len, data;
@@
-memcpy(__skb_put(skb, len), data, len);
+__skb_put_data(skb, data, len);

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

Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/linux/skbuff.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'include/linux/skbuff.h')

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 852feacf4bbf..a17e235639ae 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1904,6 +1904,28 @@ static inline void *__skb_put(struct sk_buff *skb, unsigned int len)
 	return tmp;
 }
 
+static inline void *__skb_put_zero(struct sk_buff *skb, unsigned int len)
+{
+	void *tmp = __skb_put(skb, len);
+
+	memset(tmp, 0, len);
+	return tmp;
+}
+
+static inline void *__skb_put_data(struct sk_buff *skb, const void *data,
+				   unsigned int len)
+{
+	void *tmp = __skb_put(skb, len);
+
+	memcpy(tmp, data, len);
+	return tmp;
+}
+
+static inline void __skb_put_u8(struct sk_buff *skb, u8 val)
+{
+	*(u8 *)__skb_put(skb, 1) = val;
+}
+
 static inline void *skb_put_zero(struct sk_buff *skb, unsigned int len)
 {
 	void *tmp = skb_put(skb, len);
-- 
cgit