From: Jonathan Cameron <jic23@kernel.org>
To: Colin King <colin.king@canonical.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Jon Brenner <jbrenner@taosinc.com>,
linux-iio@vger.kernel.org, clang-built-linux@googlegroups.com,
kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] iio: tsl2583: Fix division by a zero lux_val
Date: Sat, 8 May 2021 17:12:58 +0100 [thread overview]
Message-ID: <20210508171258.2ef71a70@jic23-huawei> (raw)
In-Reply-To: <20210507183041.115864-1-colin.king@canonical.com>
On Fri, 7 May 2021 19:30:41 +0100
Colin King <colin.king@canonical.com> wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> The lux_val returned from tsl2583_get_lux can potentially be zero,
> so check for this to avoid a division by zero and an overflowed
> gain_trim_val.
>
> Fixes clang scan-build warning:
>
> drivers/iio/light/tsl2583.c:345:40: warning: Either the
> condition 'lux_val<0' is redundant or there is division
> by zero at line 345. [zerodivcond]
>
> Fixes: ac4f6eee8fe8 ("staging: iio: TAOS tsl258x: Device driver")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
Definitely looks like it could happen so applied to the fixes-togreg branch of
iio.git and marked for stable.
Thanks,
Jonathan
> ---
> drivers/iio/light/tsl2583.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/iio/light/tsl2583.c b/drivers/iio/light/tsl2583.c
> index 0f787bfc88fc..c9d8f07a6fcd 100644
> --- a/drivers/iio/light/tsl2583.c
> +++ b/drivers/iio/light/tsl2583.c
> @@ -341,6 +341,14 @@ static int tsl2583_als_calibrate(struct iio_dev *indio_dev)
> return lux_val;
> }
>
> + /* Avoid division by zero of lux_value later on */
> + if (lux_val == 0) {
> + dev_err(&chip->client->dev,
> + "%s: lux_val of 0 will produce out of range trim_value\n",
> + __func__);
> + return -ENODATA;
> + }
> +
> gain_trim_val = (unsigned int)(((chip->als_settings.als_cal_target)
> * chip->als_settings.als_gain_trim) / lux_val);
> if ((gain_trim_val < 250) || (gain_trim_val > 4000)) {
next prev parent reply other threads:[~2021-05-08 16:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-07 18:30 [PATCH] iio: tsl2583: Fix division by a zero lux_val Colin King
2021-05-08 16:12 ` Jonathan Cameron [this message]
2021-05-08 17:01 ` Joe Perches
2021-05-10 6:59 ` Dan Carpenter
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