[PATCH] iio: adc: at91_adc: Correct call to input_free_device

[PATCH] iio: adc: at91_adc: Correct call to input_free_device

[Himangi Saraogi]

This error handling code can be reached before st->ts_input is
initialized, so it is safer to always use the original name, input_dev.

A simplified version of the semantic match that finds this problem is:

// <smpl>
@r exists@
local idexpression struct input_dev * x;
expression ra,rr;
@@

* x = input_allocate_device(...)
...  when != x = rr
     when != input_free_device(x,...)
     when != if (...) { ... input_free_device(x,...) ...}
if(...) { ... when != x = ra
     when forall
*     when != input_free_device(x,...)
 \(return <+...x...+>; \| return...; \) }

// </smpl>

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
---
 drivers/iio/adc/at91_adc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 3b5bacd..73b2bb5 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -1114,7 +1114,7 @@ static int at91_ts_register(struct at91_adc_state *st,
 	return ret;
 
 err:
-	input_free_device(st->ts_input);
+	input_free_device(input);
 	return ret;
 }
 
-- 
1.9.1

Re: [PATCH] iio: adc: at91_adc: Correct call to input_free_device

[Jonathan Cameron]

On 13/06/14 18:11, Himangi Saraogi wrote:
> This error handling code can be reached before st->ts_input is
> initialized, so it is safer to always use the original name, input_dev.
>
> A simplified version of the semantic match that finds this problem is:
>
> // <smpl>
> @r exists@
> local idexpression struct input_dev * x;
> expression ra,rr;
> @@
>
> * x = input_allocate_device(...)
> ...  when != x = rr
>       when != input_free_device(x,...)
>       when != if (...) { ... input_free_device(x,...) ...}
> if(...) { ... when != x = ra
>       when forall
> *     when != input_free_device(x,...)
>   \(return <+...x...+>; \| return...; \) }
>
> // </smpl>
>
> Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
The error handling in this function has been completely rewritten so the
bug is no longer there and this no longer applies.

Thanks,

Jonathan
> ---
>   drivers/iio/adc/at91_adc.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index 3b5bacd..73b2bb5 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -1114,7 +1114,7 @@ static int at91_ts_register(struct at91_adc_state *st,
>   	return ret;
>
>   err:
> -	input_free_device(st->ts_input);
> +	input_free_device(input);
>   	return ret;
>   }
>
>

Re: [PATCH] iio: adc: at91_adc: Correct call to input_free_device

[Alexandre Belloni]

On 14/06/2014 at 16:41:20 +0100, Jonathan Cameron wrote :
> On 13/06/14 18:11, Himangi Saraogi wrote:
> >This error handling code can be reached before st->ts_input is
> >initialized, so it is safer to always use the original name, input_dev.
> >
> >A simplified version of the semantic match that finds this problem is:
> >
> >// <smpl>
> >@r exists@
> >local idexpression struct input_dev * x;
> >expression ra,rr;
> >@@
> >
> >* x = input_allocate_device(...)
> >...  when != x = rr
> >      when != input_free_device(x,...)
> >      when != if (...) { ... input_free_device(x,...) ...}
> >if(...) { ... when != x = ra
> >      when forall
> >*     when != input_free_device(x,...)
> >  \(return <+...x...+>; \| return...; \) }
> >
> >// </smpl>
> >
> >Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
> The error handling in this function has been completely rewritten so the
> bug is no longer there and this no longer applies.

Hum, actually, you are wrong and I introduced that bug in 3.16. The
change didn't come from your tree so it is not up to date.

So either you take it after 3.16-rc1 or we can ask Nicolas to get it
through the at91 tree.


Either way:

Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

Re: [PATCH] iio: adc: at91_adc: Correct call to input_free_device

[Jonathan Cameron]

On 14/06/14 22:17, Alexandre Belloni wrote:
> On 14/06/2014 at 16:41:20 +0100, Jonathan Cameron wrote :
>> On 13/06/14 18:11, Himangi Saraogi wrote:
>>> This error handling code can be reached before st->ts_input is
>>> initialized, so it is safer to always use the original name, input_dev.
>>>
>>> A simplified version of the semantic match that finds this problem is:
>>>
>>> // <smpl>
>>> @r exists@
>>> local idexpression struct input_dev * x;
>>> expression ra,rr;
>>> @@
>>>
>>> * x = input_allocate_device(...)
>>> ...  when != x = rr
>>>       when != input_free_device(x,...)
>>>       when != if (...) { ... input_free_device(x,...) ...}
>>> if(...) { ... when != x = ra
>>>       when forall
>>> *     when != input_free_device(x,...)
>>>   \(return <+...x...+>; \| return...; \) }
>>>
>>> // </smpl>
>>>
>>> Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
>> The error handling in this function has been completely rewritten so the
>> bug is no longer there and this no longer applies.
>
> Hum, actually, you are wrong and I introduced that bug in 3.16. The
> change didn't come from your tree so it is not up to date.
>
> So either you take it after 3.16-rc1 or we can ask Nicolas to get it
> through the at91 tree.
Ah, that would do it!
I'm lagging a bit (just sending a pull request for some fixes from pre 3.16
merge window opening).  Will pick this up later in the week.

oops.

J
>
>
> Either way:
>
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
>