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* [PATCH] staging/iio: Use correct argument for sizeof
@ 2013-01-21 21:14 Peter Huewe
  2013-01-22  6:43 ` Dan Carpenter
  2013-01-22 11:58 ` Jonathan Cameron
  0 siblings, 2 replies; 6+ messages in thread
From: Peter Huewe @ 2013-01-21 21:14 UTC (permalink / raw)
  To: Jonathan Cameron
  Cc: Greg Kroah-Hartman, linux-iio, devel, linux-kernel, Peter Huewe

found with coccicheck
sizeof when applied to a pointer typed expression gives the size of
the pointer

The semantic patch that makes this output is available
in scripts/coccinelle/misc/noderef.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
---
 drivers/staging/iio/iio_hwmon.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/iio/iio_hwmon.c b/drivers/staging/iio/iio_hwmon.c
index c7a5f97..97ad645 100644
--- a/drivers/staging/iio/iio_hwmon.c
+++ b/drivers/staging/iio/iio_hwmon.c
@@ -93,7 +93,7 @@ static int iio_hwmon_probe(struct platform_device *pdev)
 	while (st->channels[st->num_channels].indio_dev)
 		st->num_channels++;
 
-	st->attrs = kzalloc(sizeof(st->attrs) * (st->num_channels + 1),
+	st->attrs = kzalloc(sizeof(*st->attrs) * (st->num_channels + 1),
 			    GFP_KERNEL);
 	if (st->attrs == NULL) {
 		ret = -ENOMEM;
-- 
1.7.8.6


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] staging/iio: Use correct argument for sizeof
  2013-01-21 21:14 [PATCH] staging/iio: Use correct argument for sizeof Peter Huewe
@ 2013-01-22  6:43 ` Dan Carpenter
  2013-01-22  7:02   ` Dan Carpenter
  2013-01-22  8:02   ` Lars-Peter Clausen
  2013-01-22 11:58 ` Jonathan Cameron
  1 sibling, 2 replies; 6+ messages in thread
From: Dan Carpenter @ 2013-01-22  6:43 UTC (permalink / raw)
  To: Peter Huewe
  Cc: Jonathan Cameron, linux-iio, Greg Kroah-Hartman, devel, linux-kernel

On Mon, Jan 21, 2013 at 10:14:02PM +0100, Peter Huewe wrote:
> found with coccicheck
> sizeof when applied to a pointer typed expression gives the size of
> the pointer
> 

The original code is correct, in this case.  We're storing an array
of pointers and the last element in the array is a NULL.

> The semantic patch that makes this output is available
> in scripts/coccinelle/misc/noderef.cocci.
> 
> More information about semantic patching is available at
> http://coccinelle.lip6.fr/

Can you remove those two boiler plate lines?  We all have google.

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] staging/iio: Use correct argument for sizeof
  2013-01-22  6:43 ` Dan Carpenter
@ 2013-01-22  7:02   ` Dan Carpenter
  2013-01-22  8:02   ` Lars-Peter Clausen
  1 sibling, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2013-01-22  7:02 UTC (permalink / raw)
  To: Peter Huewe
  Cc: linux-iio, Greg Kroah-Hartman, devel, Jonathan Cameron, linux-kernel

These two lines are what I meant.  Not the other stuff before.

> > More information about semantic patching is available at
> > http://coccinelle.lip6.fr/

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] staging/iio: Use correct argument for sizeof
  2013-01-22  6:43 ` Dan Carpenter
  2013-01-22  7:02   ` Dan Carpenter
@ 2013-01-22  8:02   ` Lars-Peter Clausen
  2013-01-22  8:05     ` Dan Carpenter
  1 sibling, 1 reply; 6+ messages in thread
From: Lars-Peter Clausen @ 2013-01-22  8:02 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: Peter Huewe, Jonathan Cameron, linux-iio, Greg Kroah-Hartman,
	devel, linux-kernel

On 01/22/2013 07:43 AM, Dan Carpenter wrote:
> On Mon, Jan 21, 2013 at 10:14:02PM +0100, Peter Huewe wrote:
>> found with coccicheck
>> sizeof when applied to a pointer typed expression gives the size of
>> the pointer
>>
> 
> The original code is correct, in this case.  We're storing an array
> of pointers and the last element in the array is a NULL.
> 

The patch changed sizeof(st->attrs) to sizeof(*st->attrs). The type of
st->attrs is struct attribute **, so both sizeofs return the same value (the
size of an pointer) and the code happens to work, still the later is
semantically more correct.


>> The semantic patch that makes this output is available
>> in scripts/coccinelle/misc/noderef.cocci.
>>
>> More information about semantic patching is available at
>> http://coccinelle.lip6.fr/
> 
> Can you remove those two boiler plate lines?  We all have google.

It would be nice to have a pointer to the specific cocci script used to
generate the patch though.

- Lars

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] staging/iio: Use correct argument for sizeof
  2013-01-22  8:02   ` Lars-Peter Clausen
@ 2013-01-22  8:05     ` Dan Carpenter
  0 siblings, 0 replies; 6+ messages in thread
From: Dan Carpenter @ 2013-01-22  8:05 UTC (permalink / raw)
  To: Lars-Peter Clausen
  Cc: devel, linux-iio, Greg Kroah-Hartman, linux-kernel, Jonathan Cameron

On Tue, Jan 22, 2013 at 09:02:05AM +0100, Lars-Peter Clausen wrote:
> On 01/22/2013 07:43 AM, Dan Carpenter wrote:
> > On Mon, Jan 21, 2013 at 10:14:02PM +0100, Peter Huewe wrote:
> >> found with coccicheck
> >> sizeof when applied to a pointer typed expression gives the size of
> >> the pointer
> >>
> > 
> > The original code is correct, in this case.  We're storing an array
> > of pointers and the last element in the array is a NULL.
> > 
> 
> The patch changed sizeof(st->attrs) to sizeof(*st->attrs). The type of
> st->attrs is struct attribute **, so both sizeofs return the same value (the
> size of an pointer) and the code happens to work, still the later is
> semantically more correct.
> 

Yeah.  You're right, my bad.  The patch is fine.

regards,
dan carpenter


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] staging/iio: Use correct argument for sizeof
  2013-01-21 21:14 [PATCH] staging/iio: Use correct argument for sizeof Peter Huewe
  2013-01-22  6:43 ` Dan Carpenter
@ 2013-01-22 11:58 ` Jonathan Cameron
  1 sibling, 0 replies; 6+ messages in thread
From: Jonathan Cameron @ 2013-01-22 11:58 UTC (permalink / raw)
  To: Peter Huewe
  Cc: Jonathan Cameron, Greg Kroah-Hartman, linux-iio, devel, linux-kernel

On 01/21/2013 09:14 PM, Peter Huewe wrote:
> found with coccicheck
> sizeof when applied to a pointer typed expression gives the size of
> the pointer
> 
> The semantic patch that makes this output is available
> in scripts/coccinelle/misc/noderef.cocci.
> 
> More information about semantic patching is available at
> http://coccinelle.lip6.fr/
> 
> Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Added to togreg branch of iio.git

Thanks,
> ---
>  drivers/staging/iio/iio_hwmon.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/staging/iio/iio_hwmon.c b/drivers/staging/iio/iio_hwmon.c
> index c7a5f97..97ad645 100644
> --- a/drivers/staging/iio/iio_hwmon.c
> +++ b/drivers/staging/iio/iio_hwmon.c
> @@ -93,7 +93,7 @@ static int iio_hwmon_probe(struct platform_device *pdev)
>  	while (st->channels[st->num_channels].indio_dev)
>  		st->num_channels++;
>  
> -	st->attrs = kzalloc(sizeof(st->attrs) * (st->num_channels + 1),
> +	st->attrs = kzalloc(sizeof(*st->attrs) * (st->num_channels + 1),
>  			    GFP_KERNEL);
>  	if (st->attrs == NULL) {
>  		ret = -ENOMEM;
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-01-22 11:58 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-01-21 21:14 [PATCH] staging/iio: Use correct argument for sizeof Peter Huewe
2013-01-22  6:43 ` Dan Carpenter
2013-01-22  7:02   ` Dan Carpenter
2013-01-22  8:02   ` Lars-Peter Clausen
2013-01-22  8:05     ` Dan Carpenter
2013-01-22 11:58 ` Jonathan Cameron

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