Date:   Sat, 11 Mar 2023 19:05:45 +0000
From:   Jonathan Cameron <jic23@kernel.org>
To:     James Clark <james.clark@arm.com>
Cc:     linux-kernel@vger.kernel.org, linux@roeck-us.net,
        michal.simek@amd.com, Jonathan Corbet <corbet@lwn.net>,
        Jean Delvare <jdelvare@suse.com>,
        Anand Ashok Dumbre <anand.ashok.dumbre@xilinx.com>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Michal Simek <michal.simek@xilinx.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jirislaby@kernel.org>, linux-doc@vger.kernel.org,
        linux-hwmon@vger.kernel.org, linux-iio@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-arm-msm@vger.kernel.org, linux-serial@vger.kernel.org
Subject: Re: [PATCH v2 3/4] iio: adc: Use devm_krealloc_array
Message-ID: <20230311190545.4ed8acf8@jic23-huawei>
In-Reply-To: <20230309150334.216760-4-james.clark@arm.com>
References: <20230309150334.216760-1-james.clark@arm.com>
        <20230309150334.216760-4-james.clark@arm.com>
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On Thu,  9 Mar 2023 15:03:32 +0000
James Clark <james.clark@arm.com> wrote:

> Now that it exists, use it instead of doing the multiplication and
> checking for overflow manually.
> 
> Signed-off-by: James Clark <james.clark@arm.com>

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/iio/adc/xilinx-ams.c       |  9 +++------
>  drivers/iio/adc/xilinx-xadc-core.c | 17 +++++++----------
>  2 files changed, 10 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/iio/adc/xilinx-ams.c b/drivers/iio/adc/xilinx-ams.c
> index 34cf336b3490..f0b71a1220e0 100644
> --- a/drivers/iio/adc/xilinx-ams.c
> +++ b/drivers/iio/adc/xilinx-ams.c
> @@ -1263,7 +1263,7 @@ static int ams_parse_firmware(struct iio_dev *indio_dev)
>  	struct device *dev = indio_dev->dev.parent;
>  	struct fwnode_handle *child = NULL;
>  	struct fwnode_handle *fwnode = dev_fwnode(dev);
> -	size_t ams_size, dev_size;
> +	size_t ams_size;
>  	int ret, ch_cnt = 0, i, rising_off, falling_off;
>  	unsigned int num_channels = 0;
>  
> @@ -1320,11 +1320,8 @@ static int ams_parse_firmware(struct iio_dev *indio_dev)
>  		}
>  	}
>  
> -	dev_size = array_size(sizeof(*dev_channels), num_channels);
> -	if (dev_size == SIZE_MAX)
> -		return -ENOMEM;
> -
> -	dev_channels = devm_krealloc(dev, ams_channels, dev_size, GFP_KERNEL);
> +	dev_channels = devm_krealloc_array(dev, ams_channels, num_channels,
> +					   sizeof(*dev_channels), GFP_KERNEL);
>  	if (!dev_channels)
>  		return -ENOMEM;
>  
> diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
> index 292f2892d223..dba73300f894 100644
> --- a/drivers/iio/adc/xilinx-xadc-core.c
> +++ b/drivers/iio/adc/xilinx-xadc-core.c
> @@ -613,20 +613,17 @@ static int xadc_update_scan_mode(struct iio_dev *indio_dev,
>  	const unsigned long *mask)
>  {
>  	struct xadc *xadc = iio_priv(indio_dev);
> -	size_t new_size, n;
> +	size_t n;
>  	void *data;
>  
>  	n = bitmap_weight(mask, indio_dev->masklength);
>  
> -	if (check_mul_overflow(n, sizeof(*xadc->data), &new_size))
> -		return -ENOMEM;
> -
> -	data = devm_krealloc(indio_dev->dev.parent, xadc->data,
> -			     new_size, GFP_KERNEL);
> +	data = devm_krealloc_array(indio_dev->dev.parent, xadc->data,
> +				   n, sizeof(*xadc->data), GFP_KERNEL);
>  	if (!data)
>  		return -ENOMEM;
>  
> -	memset(data, 0, new_size);
> +	memset(data, 0, n * sizeof(*xadc->data));
>  	xadc->data = data;
>  
>  	return 0;
> @@ -1281,9 +1278,9 @@ static int xadc_parse_dt(struct iio_dev *indio_dev, unsigned int *conf, int irq)
>  	}
>  
>  	indio_dev->num_channels = num_channels;
> -	indio_dev->channels = devm_krealloc(dev, channels,
> -					    sizeof(*channels) * num_channels,
> -					    GFP_KERNEL);
> +	indio_dev->channels = devm_krealloc_array(dev, channels,
> +						  num_channels, sizeof(*channels),
> +						  GFP_KERNEL);
>  	/* If we can't resize the channels array, just use the original */
>  	if (!indio_dev->channels)
>  		indio_dev->channels = channels;