[PATCH] staging:iio: correct error check

[PATCH] staging:iio: correct error check

[Julia Lawall]

From: Julia Lawall <Julia.Lawall@lip6.fr>

iio_kfifo_allocate returns NULL in case of error.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression *x;
identifier f;
statement S1,S2;
@@

*x = f(...);
 if (x) { <+... when != if (...) S1 else S2
     -ENOMEM ...+> }
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/staging/iio/impedance-analyzer/ad5933.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
index 0a4298b..2b96665 100644
--- a/drivers/staging/iio/impedance-analyzer/ad5933.c
+++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
@@ -629,7 +629,7 @@ static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
 	struct iio_buffer *buffer;
 
 	buffer = iio_kfifo_allocate(indio_dev);
-	if (buffer)
+	if (!buffer)
 		return -ENOMEM;
 
 	iio_device_attach_buffer(indio_dev, buffer);

Re: [PATCH] staging:iio: correct error check

[Jonathan Cameron]

On 01/01/14 13:07, Julia Lawall wrote:
> From: Julia Lawall <Julia.Lawall@lip6.fr>
>
> iio_kfifo_allocate returns NULL in case of error.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression *x;
> identifier f;
> statement S1,S2;
> @@
>
> *x = f(...);
>   if (x) { <+... when != if (...) S1 else S2
>       -ENOMEM ...+> }
> // </smpl>
>
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Thanks. Certainly an 'interesting' bit of code :(

Applied to the fixes-togreg branch of iio.git. Giving timing in the 
current cycle and that it isn't a recent regression, this won't go
in now until after 3.13 is released.

I've marked it for stable as well

Jonathan
>
> ---
>   drivers/staging/iio/impedance-analyzer/ad5933.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c
> index 0a4298b..2b96665 100644
> --- a/drivers/staging/iio/impedance-analyzer/ad5933.c
> +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c
> @@ -629,7 +629,7 @@ static int ad5933_register_ring_funcs_and_init(struct iio_dev *indio_dev)
>   	struct iio_buffer *buffer;
>
>   	buffer = iio_kfifo_allocate(indio_dev);
> -	if (buffer)
> +	if (!buffer)
>   		return -ENOMEM;
>
>   	iio_device_attach_buffer(indio_dev, buffer);
>
> --
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