Jan 09 2009

drivers/isdn/hardware/mISDN: 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: Andrew Morton 
Signed-off-by: David S. Miller 

---
 drivers/isdn/hardware/mISDN/hfcmulti.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
 
diff --git a/drivers/isdn/hardware/mISDN/hfcmulti.c b/drivers/isdn/hardware/mISDN/hfcmulti.c
index 97f4708..595ba8e 100644
--- a/drivers/isdn/hardware/mISDN/hfcmulti.c
+++ b/drivers/isdn/hardware/mISDN/hfcmulti.c
@@ -3615,7 +3615,7 @@ hfcm_bctrl(struct mISDNchannel *ch, u_int cmd, void *arg)
 static void
 ph_state_change(struct dchannel *dch)
 {
-	struct hfc_multi *hc = dch->hw;
+	struct hfc_multi *hc;
 	int ch, i;
 
 	if (!dch) {
@@ -3623,6 +3623,7 @@ ph_state_change(struct dchannel *dch)
 		    __func__);
 		return;
 	}
+	hc = dch->hw;
 	ch = dch->slot;
 
 	if (hc->type == 1) {

qlambert