On Thu, 03 Oct 2024 19:34:09 +0200
Matteo Martelli <matteomartelli3@xxxxxxxxx> wrote:
> While available integration times are being printed to sysfs by iio core
> (iio_read_channel_info_avail), the sampling frequency might be changed.
> This could cause the buffer shared with iio core to be corrupted. To
> prevent it, make a copy of the integration times buffer and free it in
> the read_avail_release_resource callback.
>
> Signed-off-by: Matteo Martelli <matteomartelli3@xxxxxxxxx>
> ---
> drivers/iio/light/as73211.c | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/light/as73211.c b/drivers/iio/light/as73211.c
> index be0068081ebbbb37fdfb252b67a77b302ff725f6..520c898e0ff9c530b4fdd45589559f9014d7992c 100644
> --- a/drivers/iio/light/as73211.c
> +++ b/drivers/iio/light/as73211.c
> @@ -493,17 +493,33 @@ static int as73211_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec co
> *type = IIO_VAL_INT;
> return IIO_AVAIL_LIST;
>
> - case IIO_CHAN_INFO_INT_TIME:
> + case IIO_CHAN_INFO_INT_TIME: {
> *length = ARRAY_SIZE(data->int_time_avail);
> - *vals = data->int_time_avail;
> *type = IIO_VAL_INT_PLUS_MICRO;
> - return IIO_AVAIL_LIST;
>
> + guard(mutex)(&data->mutex);
> +
> + *vals = kmemdup_array(data->int_time_avail, *length,
> + sizeof(int), GFP_KERNEL);
> + if (!*vals)
> + return -ENOMEM;
> +
> + return IIO_AVAIL_LIST;
> + }
> default:
> return -EINVAL;
> }
> }
>
> +static void as73211_read_avail_release_res(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + const int *vals, long mask)
> +{
> + if (mask == IIO_CHAN_INFO_INT_TIME)
> + kfree(vals);
> +}
> +
Trivial but one blank line is enough. If there is no other feedback on the
series I can tidy this up whilst applying.
> +
> static int _as73211_write_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan __always_unused,
> int val, int val2, long mask)
> @@ -699,6 +715,7 @@ static irqreturn_t as73211_trigger_handler(int irq __always_unused, void *p)
> static const struct iio_info as73211_info = {
> .read_raw = as73211_read_raw,
> .read_avail = as73211_read_avail,
> + .read_avail_release_resource = as73211_read_avail_release_res,
> .write_raw = as73211_write_raw,
> };
>
>
