Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Mon, 3 Oct 2022 11:43:20 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Matti Vaittinen <mazziesaccount@gmail.com>
Cc:     Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Michael Hennerich <Michael.Hennerich@analog.com>,
        Cosmin Tanislav <cosmin.tanislav@analog.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Eugen Hristev <eugen.hristev@microchip.com>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Claudiu Beznea <claudiu.beznea@microchip.com>,
        Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        Alexandru Ardelean <alexandru.ardelean@analog.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Miaoqian Lin <linmq006@gmail.com>,
        Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Paul Cercueil <paul@crapouillou.net>,
        Mihail Chindris <mihail.chindris@analog.com>,
        Gwendal Grignou <gwendal@chromium.org>,
        linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        chrome-platform@lists.linux.dev
Subject: Re: [RFT PATCH v3 10/10] iio: Don't silently expect attribute types
Message-ID: <YzqgqERDTLVkJH67@smile.fi.intel.com>
References: <cover.1664782676.git.mazziesaccount@gmail.com>
 <63f54787a684eb1232f1c5d275a09c786987fe4a.1664782676.git.mazziesaccount@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <63f54787a684eb1232f1c5d275a09c786987fe4a.1664782676.git.mazziesaccount@gmail.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Precedence: bulk

On Mon, Oct 03, 2022 at 11:13:53AM +0300, Matti Vaittinen wrote:
> The iio_triggered_buffer_setup_ext() and the
> devm_iio_kfifo_buffer_setup_ext() were changed by
> commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
> to silently expect that all attributes given in buffer_attrs array are
> device-attributes. This expectation was not forced by the API - and some
> drivers did register attributes created by IIO_CONST_ATTR().
> 
> When using IIO_CONST_ATTRs the added attribute "wrapping" does not copy
> the pointer to stored string constant and when the sysfs file is read the
> kernel will access to invalid location.
> 
> Change the function signatures to expect an array of iio_dev_attrs to
> avoid similar errors in the future.

...


Wouldn't be better to split this on per driver basis or is it impossible?

>  drivers/iio/accel/adxl367.c                          | 10 +++++-----
>  drivers/iio/accel/adxl372.c                          | 10 +++++-----
>  drivers/iio/accel/bmc150-accel-core.c                | 12 ++++++------
>  drivers/iio/adc/at91-sama5d2_adc.c                   | 12 ++++++------
>  drivers/iio/buffer/industrialio-buffer-dmaengine.c   |  4 ++--
>  drivers/iio/buffer/industrialio-triggered-buffer.c   |  4 ++--
>  drivers/iio/buffer/kfifo_buf.c                       |  2 +-
>  .../common/cros_ec_sensors/cros_ec_sensors_core.c    |  6 +++---
>  drivers/iio/common/hid-sensors/hid-sensor-trigger.c  |  8 ++++----
>  drivers/iio/industrialio-buffer.c                    | 11 +++++++----
>  include/linux/iio/buffer_impl.h                      |  2 +-
>  include/linux/iio/kfifo_buf.h                        |  3 ++-
>  include/linux/iio/triggered_buffer.h                 |  6 +++---

...

>  	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
>  	struct iio_dev_attr *p;

> +	const struct iio_dev_attr *id_attr;

I'm wondering if we may keep this upper, so "longer line goes first" rule would
be satisfied.

>  	struct attribute **attr;
>  	int ret, i, attrn, scan_el_attrcount, buffer_attrcount;
>  	const struct iio_chan_spec *channels;

...

> +		for (i = 0, id_attr = buffer->attrs[i];
> +		     (id_attr = buffer->attrs[i]); i++)

Not sure why we have additional parentheses...

> +			attr[ARRAY_SIZE(iio_buffer_attrs) + i] =
> +				(struct attribute *)&id_attr->dev_attr.attr;

...and explicit casting here. Isn't attr is already of a struct attribute?

-- 
With Best Regards,
Andy Shevchenko