From: Julia Lawall <Julia.Lawall@lip6.fr>
Date: Tue, 14 Aug 2012 05:49:47 +0000 (+0000)
Subject: drivers/net/ethernet/ti/davinci_cpdma.c: Remove potential NULL dereference
X-Git-Tag: firefly_0821_release~3680^2~2176^2~44
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f37c54b6a6c56489221d42ff27305e4f8098e34b;p=firefly-linux-kernel-4.4.55.git

drivers/net/ethernet/ti/davinci_cpdma.c: Remove potential NULL dereference

If the NULL test is necessary, the initialization involving a dereference of
the tested value should be moved after the NULL test.

The sematic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
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;
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
index 3b5c4571b55e..d15c888e9df8 100644
--- a/drivers/net/ethernet/ti/davinci_cpdma.c
+++ b/drivers/net/ethernet/ti/davinci_cpdma.c
@@ -538,11 +538,12 @@ EXPORT_SYMBOL_GPL(cpdma_chan_create);
 
 int cpdma_chan_destroy(struct cpdma_chan *chan)
 {
-	struct cpdma_ctlr *ctlr = chan->ctlr;
+	struct cpdma_ctlr *ctlr;
 	unsigned long flags;
 
 	if (!chan)
 		return -EINVAL;
+	ctlr = chan->ctlr;
 
 	spin_lock_irqsave(&ctlr->lock, flags);
 	if (chan->state != CPDMA_STATE_IDLE)