Dec 17 2008

drivers/net/hamradio: Move a dereference below a NULL test 

Author: Julia Lawall <julia@diku.dk>

In each case, if the NULL test is necessary, then the dereference should be
moved below the NULL test.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E
      when != i
  if (E == NULL) S
+ i = E->fld;
// 

Signed-off-by: Julia Lawall 
Signed-off-by: David S. Miller 

---
 drivers/net/hamradio/mkiss.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
 
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index 7570c73..bbdb311 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -846,12 +846,13 @@ static int mkiss_ioctl(struct tty_struct *tty, struct file *file,
 	unsigned int cmd, unsigned long arg)
 {
 	struct mkiss *ax = mkiss_get(tty);
-	struct net_device *dev = ax->dev;
+	struct net_device *dev;
 	unsigned int tmp, err;
 
 	/* First make sure we're connected. */
 	if (ax == NULL)
 		return -ENXIO;
+	dev = ax->dev;
 
 	switch (cmd) {
  	case SIOCGIFNAME:

qlambert