[PATCH 4/5] drivers/net/can: Correct NULL test

[PATCH 4/5] drivers/net/can: Correct NULL test

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

Test the just-allocated value for NULL rather than some other value.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,y;
statement S;
@@

x = \(kmalloc\|kcalloc\|kzalloc\)(...);
(
if ((x) == NULL) S
|
if (
-   y
+   x
       == NULL)
 S
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 drivers/net/can/mcp251x.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -u -p a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
--- a/drivers/net/can/mcp251x.c
+++ b/drivers/net/can/mcp251x.c
@@ -990,7 +990,7 @@ static int __devinit mcp251x_can_probe(s
 			goto error_tx_buf;
 		}
 		priv->spi_rx_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL);
-		if (!priv->spi_tx_buf) {
+		if (!priv->spi_rx_buf) {
 			ret = -ENOMEM;
 			goto error_rx_buf;
 		}

Re: [PATCH 4/5] drivers/net/can: Correct NULL test

[Oliver Hartkopp]

Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>

Thanks Julia!

I added Christian Pellegrin who is the author of this driver in CC.

An obvious copy/paste error :-)

Regards,
Oliver

Acked-by: Oliver Hartkopp <oliver@hartkopp.net>

> 
> Test the just-allocated value for NULL rather than some other value.
> 
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@
> expression x,y;
> statement S;
> @@
> 
> x = \(kmalloc\|kcalloc\|kzalloc\)(...);
> (
> if ((x) == NULL) S
> |
> if (
> -   y
> +   x
>        == NULL)
>  S
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
>  drivers/net/can/mcp251x.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff -u -p a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
> --- a/drivers/net/can/mcp251x.c
> +++ b/drivers/net/can/mcp251x.c
> @@ -990,7 +990,7 @@ static int __devinit mcp251x_can_probe(s
>  			goto error_tx_buf;
>  		}
>  		priv->spi_rx_buf = kmalloc(SPI_TRANSFER_BUF_LEN, GFP_KERNEL);
> -		if (!priv->spi_tx_buf) {
> +		if (!priv->spi_rx_buf) {
>  			ret = -ENOMEM;
>  			goto error_rx_buf;
>  		}
> --
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Re: [PATCH 4/5] drivers/net/can: Correct NULL test

[christian pellegrin]

On Mon, Dec 28, 2009 at 2:49 PM, Oliver Hartkopp <socketcan@hartkopp.net> wrote:
> Julia Lawall wrote:
>> From: Julia Lawall <julia@diku.dk>
>
> Thanks Julia!
>
> I added Christian Pellegrin who is the author of this driver in CC.
>
> An obvious copy/paste error :-)
>

yes, exactly that: copy & paste is among the sweetest evils out there.
I'll try the semantic checker myself next time. Thanks!



-- 
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."

Re: [PATCH 4/5] drivers/net/can: Correct NULL test

[David Miller]

From: Julia Lawall <julia@diku.dk>
Date: Sun, 27 Dec 2009 22:27:44 +0100 (CET)

> From: Julia Lawall <julia@diku.dk>
> 
> Test the just-allocated value for NULL rather than some other value.
 ...
> Signed-off-by: Julia Lawall <julia@diku.dk>

Applied.