2010-10-15 12:54:10

by Julia Lawall

Subject: [PATCH 3/7] drivers/net/wireless/p54/eeprom.c: Return -ENOMEM on memory allocation failure

From: Julia Lawall <[email protected]>

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

A simplified version of the semantic match that finds this 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 <[email protected]>

---
drivers/net/wireless/p54/eeprom.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff -u -p a/drivers/net/wireless/p54/eeprom.c b/drivers/net/wireless/p54/eeprom.c
--- a/drivers/net/wireless/p54/eeprom.c
+++ b/drivers/net/wireless/p54/eeprom.c
@@ -261,8 +261,10 @@ static int p54_generate_channel_lists(st
list->max_entries = max_channel_num;
list->channels = kzalloc(sizeof(struct p54_channel_entry) *
max_channel_num, GFP_KERNEL);
- if (!list->channels)
+ if (!list->channels) {
+ ret = -ENOMEM;
goto free;
+ }

for (i = 0; i < max_channel_num; i++) {
if (i < priv->iq_autocal_len) {

2010-10-16 00:28:11

by Christian Lamparter

Subject: Re: [PATCH 3/7] drivers/net/wireless/p54/eeprom.c: Return -ENOMEM on memory allocation failure

On Friday 15 October 2010 15:00:06 Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> In this code, 0 is returned on memory allocation failure, even though other
> failures return -ENOMEM or other similar values.
>
> A simplified version of the semantic match that finds this 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 <[email protected]>
Cc: <[email protected]>
Acked-by: Christian Lamparter <[email protected]>

> ---
> drivers/net/wireless/p54/eeprom.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff -u -p a/drivers/net/wireless/p54/eeprom.c b/drivers/net/wireless/p54/eeprom.c
> --- a/drivers/net/wireless/p54/eeprom.c
> +++ b/drivers/net/wireless/p54/eeprom.c
> @@ -261,8 +261,10 @@ static int p54_generate_channel_lists(st
> list->max_entries = max_channel_num;
> list->channels = kzalloc(sizeof(struct p54_channel_entry) *
> max_channel_num, GFP_KERNEL);
> - if (!list->channels)
> + if (!list->channels) {
> + ret = -ENOMEM;
> goto free;
> + }
>
> for (i = 0; i < max_channel_num; i++) {
> if (i < priv->iq_autocal_len) {
>
>