Patchwork [2/4] drivers/net/hamradio/6pack.c: move a dereference below a NULL test

login
register
mail settings
Submitter Andrew Morton
Date Jan. 9, 2009, 8:23 p.m.
Message ID <200901092023.n09KN91a020170@imap1.linux-foundation.org>
Download mbox | patch
Permalink /patch/17584/
State Accepted
Delegated to: David Miller
Headers show

Comments

Andrew Morton - Jan. 9, 2009, 8:23 p.m.
From: 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/)

// <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@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/net/hamradio/6pack.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
David Miller - Jan. 10, 2009, 7:10 a.m.
Applied.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff -puN drivers/net/hamradio/6pack.c~drivers-net-hamradio-6packc-move-a-dereference-below-a-null-test drivers/net/hamradio/6pack.c
--- a/drivers/net/hamradio/6pack.c~drivers-net-hamradio-6packc-move-a-dereference-below-a-null-test
+++ a/drivers/net/hamradio/6pack.c
@@ -717,11 +717,12 @@  static int sixpack_ioctl(struct tty_stru
 	unsigned int cmd, unsigned long arg)
 {
 	struct sixpack *sp = sp_get(tty);
-	struct net_device *dev = sp->dev;
+	struct net_device *dev;
 	unsigned int tmp, err;
 
 	if (!sp)
 		return -ENXIO;
+	dev = sp->dev;
 
 	switch(cmd) {
 	case SIOCGIFNAME: