Jul 17 2010

net: dccp: fix sign bug 

Author: Kulikov Vasiliy <segooon@gmail.com>

'gap' is unsigned, so this code is wrong:

    gap = -new_head;
    ...
    if (gap > 0) { ... }

Make 'gap' signed.

The semantic patch that finds this problem (many false-positive results):
(http://coccinelle.lip6.fr/)

// 
@ r1 @
identifier f;
@@
int f(...) { ... }

@@
identifier r1.f;
type T;
unsigned T x;
@@

*x = f(...)
 ...
*x > 0

Signed-off-by: Kulikov Vasiliy 
Signed-off-by: David S. Miller 

---
 net/dccp/ackvec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
 
diff --git a/net/dccp/ackvec.c b/net/dccp/ackvec.c
index 2abddee..92a6fcb 100644
--- a/net/dccp/ackvec.c
+++ b/net/dccp/ackvec.c
@@ -201,7 +201,7 @@ static inline int dccp_ackvec_set_buf_head_state(struct dccp_ackvec *av,
 						 const unsigned int packets,
 						 const unsigned char state)
 {
-	unsigned int gap;
+	long gap;
 	long new_head;
 
 	if (av->av_vec_len + packets > DCCP_MAX_ACKVEC_LEN)

qlambert