[PATCH] staging:iio:max1363: Don't free uninitialized variable

[PATCH] staging:iio:max1363: Don't free uninitialized variable

[Lars-Peter Clausen]

It is possible that on one of the error paths we are going to try to free
'rxbuf', even though it has not been allocated yet, which cause the following
warning:
	drivers/staging/iio/adc/max1363_ring.c: In function 'max1363_trigger_handler':
		drivers/staging/iio/adc/max1363_ring.c:87:7: warning: 'rxbuf' may be used
		uninitialized in this function

Reported-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/staging/iio/adc/max1363_ring.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/iio/adc/max1363_ring.c b/drivers/staging/iio/adc/max1363_ring.c
index bf6b0c2..774ae1b 100644
--- a/drivers/staging/iio/adc/max1363_ring.c
+++ b/drivers/staging/iio/adc/max1363_ring.c
@@ -74,7 +74,7 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
 	else
 		b_sent = i2c_master_recv(st->client, rxbuf, numvals);
 	if (b_sent < 0)
-		goto done;
+		goto done_free;
 
 	time_ns = iio_get_time_ns();
 
@@ -82,9 +82,10 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
 		memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
 	iio_push_to_buffer(indio_dev->buffer, rxbuf, time_ns);
 
+done_free:
+	kfree(rxbuf);
 done:
 	iio_trigger_notify_done(indio_dev->trig);
-	kfree(rxbuf);
 
 	return IRQ_HANDLED;
 }
-- 
1.7.10.4

Re: [PATCH] staging:iio:max1363: Don't free uninitialized variable

[Jonathan Cameron]

On 07/11/2012 10:28 AM, Lars-Peter Clausen wrote:
> It is possible that on one of the error paths we are going to try to free
> 'rxbuf', even though it has not been allocated yet, which cause the following
> warning:
> 	drivers/staging/iio/adc/max1363_ring.c: In function 'max1363_trigger_handler':
> 		drivers/staging/iio/adc/max1363_ring.c:87:7: warning: 'rxbuf' may be used
> 		uninitialized in this function
> 
> Reported-by: Fengguang Wu <wfg@linux.intel.com>
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
merged to fixes-togreg and pull request sent.
> ---
>  drivers/staging/iio/adc/max1363_ring.c |    5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/iio/adc/max1363_ring.c b/drivers/staging/iio/adc/max1363_ring.c
> index bf6b0c2..774ae1b 100644
> --- a/drivers/staging/iio/adc/max1363_ring.c
> +++ b/drivers/staging/iio/adc/max1363_ring.c
> @@ -74,7 +74,7 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
>  	else
>  		b_sent = i2c_master_recv(st->client, rxbuf, numvals);
>  	if (b_sent < 0)
> -		goto done;
> +		goto done_free;
>  
>  	time_ns = iio_get_time_ns();
>  
> @@ -82,9 +82,10 @@ static irqreturn_t max1363_trigger_handler(int irq, void *p)
>  		memcpy(rxbuf + d_size - sizeof(s64), &time_ns, sizeof(time_ns));
>  	iio_push_to_buffer(indio_dev->buffer, rxbuf, time_ns);
>  
> +done_free:
> +	kfree(rxbuf);
>  done:
>  	iio_trigger_notify_done(indio_dev->trig);
> -	kfree(rxbuf);
>  
>  	return IRQ_HANDLED;
>  }
>