[PATCH] pwm: devm: alloc correct pointer size

[PATCH] pwm: devm: alloc correct pointer size

[Wolfram Sang]

The allocated object should be the size of what the pointer is pointing
to and not the size of the pointer itself.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
 drivers/pwm/core.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 32221cb..0cf0f65 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -694,7 +694,7 @@ struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id)
 {
 	struct pwm_device **ptr, *pwm;
 
-	ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL);
+	ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
@@ -724,7 +724,7 @@ struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np,
 {
 	struct pwm_device **ptr, *pwm;
 
-	ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL);
+	ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL);
 	if (!ptr)
 		return ERR_PTR(-ENOMEM);
 
-- 
1.7.10.4

Re: [PATCH] pwm: devm: alloc correct pointer size

[Andy Shevchenko]

On Mon, Jun 3, 2013 at 11:27 PM, Wolfram Sang <wsa@the-dreams.de> wrote:
> The allocated object should be the size of what the pointer is pointing
> to and not the size of the pointer itself.

All devm_* functions in this module use **ptr as a parameter (except
allocation).
May be we first should understand why it so?
If it wrong approach, than probably you have to change **ptr -> *ptr.
But without answer on first question I don't know if it proper solution or not.

--
With Best Regards,
Andy Shevchenko

Re: [PATCH] pwm: devm: alloc correct pointer size

[Wolfram Sang]

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On Thu, Jun 06, 2013 at 10:43:41PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 3, 2013 at 11:27 PM, Wolfram Sang <wsa@the-dreams.de> wrote:
> > The allocated object should be the size of what the pointer is pointing
> > to and not the size of the pointer itself.
> 
> All devm_* functions in this module use **ptr as a parameter (except
> allocation).
> May be we first should understand why it so?

Huh? **ptr is already created on the stack, but assigned the alloced
memory. Later, the mem it points to is set to 'pwm' which is then added
to devres. So, the alloced memory must be able to contain '*ptr' (or
*pwm which would be more readable IMO, but other subsystems also stick
to *ptr), no?


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Re: [PATCH] pwm: devm: alloc correct pointer size

[Andy Shevchenko]

On Mon, Jun 10, 2013 at 3:04 AM, Wolfram Sang <wsa@the-dreams.de> wrote:
> On Thu, Jun 06, 2013 at 10:43:41PM +0300, Andy Shevchenko wrote:
>> On Mon, Jun 3, 2013 at 11:27 PM, Wolfram Sang <wsa@the-dreams.de> wrote:
>> > The allocated object should be the size of what the pointer is pointing
>> > to and not the size of the pointer itself.
>>
>> All devm_* functions in this module use **ptr as a parameter (except
>> allocation).
>> May be we first should understand why it so?
>
> Huh? **ptr is already created on the stack, but assigned the alloced
> memory. Later, the mem it points to is set to 'pwm' which is then added
> to devres. So, the alloced memory must be able to contain '*ptr' (or
> *pwm which would be more readable IMO, but other subsystems also stick
> to *ptr), no?

Yes, you right.
Take my Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

--
With Best Regards,
Andy Shevchenko

Re: [PATCH] pwm: devm: alloc correct pointer size

[Thierry Reding]

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On Mon, Jun 10, 2013 at 09:41:52AM +0300, Andy Shevchenko wrote:
> On Mon, Jun 10, 2013 at 3:04 AM, Wolfram Sang <wsa@the-dreams.de> wrote:
> > On Thu, Jun 06, 2013 at 10:43:41PM +0300, Andy Shevchenko wrote:
> >> On Mon, Jun 3, 2013 at 11:27 PM, Wolfram Sang <wsa@the-dreams.de> wrote:
> >> > The allocated object should be the size of what the pointer is pointing
> >> > to and not the size of the pointer itself.
> >>
> >> All devm_* functions in this module use **ptr as a parameter (except
> >> allocation).
> >> May be we first should understand why it so?
> >
> > Huh? **ptr is already created on the stack, but assigned the alloced
> > memory. Later, the mem it points to is set to 'pwm' which is then added
> > to devres. So, the alloced memory must be able to contain '*ptr' (or
> > *pwm which would be more readable IMO, but other subsystems also stick
> > to *ptr), no?
> 
> Yes, you right.
> Take my Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Applied, thanks.

Thierry

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