Re: [PATCH 5/5] drivers/iio/industrialio-event.c: eliminate possibledouble free

From: Jonathan Cameron
Date: Fri Nov 02 2012 - 05:39:04 EST


On 10/21/2012 11:52 AM, Julia Lawall wrote:
> From: Julia Lawall <Julia.Lawall@xxxxxxx>
>
> The function __iio_add_event_config_attrs is only called once, by the
> function iio_device_register_eventset. If the call fails,
> iio_device_register_eventset calls __iio_remove_event_config_attrs. There
> is thus no need for __iio_add_event_config_attrs to also call
> __iio_remove_event_config_attrs on failure.
>
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @r@
> identifier f,free,a;
> parameter list[n] ps;
> type T;
> expression e;
> @@
>
> f(ps,T a,...) {
> ... when any
> when != a = e
> if(...) { ... free(a); ... return ...; }
> ... when any
> }
>
> @@
> identifier r.f,r.free;
> expression x,a;
> expression list[r.n] xs;
> @@
>
> * x = f(xs,a,...);
> if (...) { ... free(a); ... return ...; }
> // </smpl>
>
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

Thanks - merged to fixes-togreg branch of iio.git

Jonathan
>
> ---
> __iio_remove_event_config_attrs kfrees the elements of a list, but doesn't
> actually remove them from the list. Perhaps for safety this should be
> cleaned up as well. Not tested.
>
> drivers/iio/industrialio-event.c | 7 +------
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
> index fa6543b..78570c7 100644
> --- a/drivers/iio/industrialio-event.c
> +++ b/drivers/iio/industrialio-event.c
> @@ -350,15 +350,10 @@ static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
> ret = iio_device_add_event_sysfs(indio_dev,
> &indio_dev->channels[j]);
> if (ret < 0)
> - goto error_clear_attrs;
> + return ret;
> attrcount += ret;
> }
> return attrcount;
> -
> -error_clear_attrs:
> - __iio_remove_event_config_attrs(indio_dev);
> -
> - return ret;
> }
>
> static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
>
> --
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