[PATCH 1/7] drivers/net/irda/irtty-sir.c: Return -ENOMEM on memory allocation failure

From: Julia Lawall
Date: Fri Oct 15 2010 - 08:54:28 EST


From: Julia Lawall <julia@xxxxxxx>

In this code, 0 is returned on memory allocation failure, even though other
failures return -ENOMEM or other similar values.

The initial value of ret as 0 is never used, so drop the initialization.

A simplified version of the semantic match that finds the first problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression ret;
expression x,e1,e2,e3;
@@

ret = 0
... when != ret = e1
*x = \(kmalloc\|kcalloc\|kzalloc\)(...)
... when != ret = e2
if (x == NULL) { ... when != ret = e3
return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/net/irda/irtty-sir.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff -u -p a/drivers/net/irda/irtty-sir.c b/drivers/net/irda/irtty-sir.c
--- a/drivers/net/irda/irtty-sir.c
+++ b/drivers/net/irda/irtty-sir.c
@@ -426,7 +426,7 @@ static int irtty_open(struct tty_struct
{
struct sir_dev *dev;
struct sirtty_cb *priv;
- int ret = 0;
+ int ret;

/* Module stuff handled via irda_ldisc.owner - Jean II */

@@ -459,8 +459,10 @@ static int irtty_open(struct tty_struct

/* allocate private device info block */
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
- if (!priv)
+ if (!priv) {
+ ret = -ENOMEM;
goto out_put;
+ }

priv->magic = IRTTY_MAGIC;
priv->tty = tty;

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