[PATCH] staging: iio: ad9832: allocate data before using

[PATCH] staging: iio: ad9832: allocate data before using

[Arnd Bergmann]

The regulator changes assigned data to an uninitialized pointer:

drivers/staging/iio/frequency/ad9832.c: In function 'ad9832_probe':
drivers/staging/iio/frequency/ad9832.c:214:11: error: 'st' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This moves the allocation of the 'st' structure before its first
use, as it should have been.

Fixes: 43a07e48af44 ("staging: iio: ad9832: clean-up regulator 'reg'")
Fixes: a98461d79ba5 ("staging: iio: ad9832: add DVDD regulator")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/staging/iio/frequency/ad9832.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index 639047fade30..a5b2f068168d 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -211,6 +211,13 @@ static int ad9832_probe(struct spi_device *spi)
 		return -ENODEV;
 	}
 
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, indio_dev);
+	st = iio_priv(indio_dev);
+
 	st->avdd = devm_regulator_get(&spi->dev, "avdd");
 	if (IS_ERR(st->avdd))
 		return PTR_ERR(st->avdd);
@@ -233,13 +240,6 @@ static int ad9832_probe(struct spi_device *spi)
 		goto error_disable_avdd;
 	}
 
-	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
-	if (!indio_dev) {
-		ret = -ENOMEM;
-		goto error_disable_dvdd;
-	}
-	spi_set_drvdata(spi, indio_dev);
-	st = iio_priv(indio_dev);
 	st->mclk = pdata->mclk;
 	st->spi = spi;
 
-- 
2.9.0

Re: [PATCH] staging: iio: ad9832: allocate data before using

[Jonathan Cameron]

On 08/11/16 14:00, Arnd Bergmann wrote:
> The regulator changes assigned data to an uninitialized pointer:
> 
> drivers/staging/iio/frequency/ad9832.c: In function 'ad9832_probe':
> drivers/staging/iio/frequency/ad9832.c:214:11: error: 'st' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 
> This moves the allocation of the 'st' structure before its first
> use, as it should have been.
> 
> Fixes: 43a07e48af44 ("staging: iio: ad9832: clean-up regulator 'reg'")
> Fixes: a98461d79ba5 ("staging: iio: ad9832: add DVDD regulator")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Thanks Arnd.

I think I've gotten too reliant on zero day and clearly am not checking my local
build warnings closely enough.  Time to go back to doing pre push out checks more
thoroughly.

Anyhow, applied to the togreg branch of iio.git.  Will probably be the weekend
at least before I send another pull request.

Thanks,

Jonathan
> ---
>  drivers/staging/iio/frequency/ad9832.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
> index 639047fade30..a5b2f068168d 100644
> --- a/drivers/staging/iio/frequency/ad9832.c
> +++ b/drivers/staging/iio/frequency/ad9832.c
> @@ -211,6 +211,13 @@ static int ad9832_probe(struct spi_device *spi)
>  		return -ENODEV;
>  	}
>  
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	spi_set_drvdata(spi, indio_dev);
> +	st = iio_priv(indio_dev);
> +
>  	st->avdd = devm_regulator_get(&spi->dev, "avdd");
>  	if (IS_ERR(st->avdd))
>  		return PTR_ERR(st->avdd);
> @@ -233,13 +240,6 @@ static int ad9832_probe(struct spi_device *spi)
>  		goto error_disable_avdd;
>  	}
>  
> -	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> -	if (!indio_dev) {
> -		ret = -ENOMEM;
> -		goto error_disable_dvdd;
> -	}
> -	spi_set_drvdata(spi, indio_dev);
> -	st = iio_priv(indio_dev);
>  	st->mclk = pdata->mclk;
>  	st->spi = spi;
>  
> 

Re: [PATCH] staging: iio: ad9832: allocate data before using

[Eva Rachel Retuya]

On Tue, Nov 08, 2016 at 03:00:49PM +0100, Arnd Bergmann wrote:
> The regulator changes assigned data to an uninitialized pointer:
> 
> drivers/staging/iio/frequency/ad9832.c: In function 'ad9832_probe':
> drivers/staging/iio/frequency/ad9832.c:214:11: error: 'st' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 
> This moves the allocation of the 'st' structure before its first
> use, as it should have been.
> 
> Fixes: 43a07e48af44 ("staging: iio: ad9832: clean-up regulator 'reg'")
> Fixes: a98461d79ba5 ("staging: iio: ad9832: add DVDD regulator")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thank you, I completely missed this. Will be more careful next time.

Eva

> ---
>  drivers/staging/iio/frequency/ad9832.c | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
> index 639047fade30..a5b2f068168d 100644
> --- a/drivers/staging/iio/frequency/ad9832.c
> +++ b/drivers/staging/iio/frequency/ad9832.c
> @@ -211,6 +211,13 @@ static int ad9832_probe(struct spi_device *spi)
>  		return -ENODEV;
>  	}
>  
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	spi_set_drvdata(spi, indio_dev);
> +	st = iio_priv(indio_dev);
> +
>  	st->avdd = devm_regulator_get(&spi->dev, "avdd");
>  	if (IS_ERR(st->avdd))
>  		return PTR_ERR(st->avdd);
> @@ -233,13 +240,6 @@ static int ad9832_probe(struct spi_device *spi)
>  		goto error_disable_avdd;
>  	}
>  
> -	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> -	if (!indio_dev) {
> -		ret = -ENOMEM;
> -		goto error_disable_dvdd;
> -	}
> -	spi_set_drvdata(spi, indio_dev);
> -	st = iio_priv(indio_dev);
>  	st->mclk = pdata->mclk;
>  	st->spi = spi;
>  
> -- 
> 2.9.0
>