On Mon, 30 Sep 2019 12:53:54 -0700
Yizhuo <yzhai003@xxxxxxx> wrote:
> In function mx25_gcq_irq(), local variable "stats" could
> be uninitialized if function regmap_read() returns -EINVAL.
> However, this value is used in if statement, which is
> potentially unsafe. The same case applied to the variable
> "data" in function mx25_gcq_get_raw_value() in the same file.
>
> Signed-off-by: Yizhuo <yzhai003@xxxxxxx>
Following similar logic to the other patch I just reviewed
for the stm32-timer-trigger, lets chase if this can happen.
In this case a clock is not provided during the regmap iomem register
and as such, the call can't actually fail.
So this one is more of a tidy up and hardening against future
problems if the code changes, than an actual fix.
Worth having, but perhaps remove the word fix from the description
unless you can find a path I've missed in which this might actually
happen as the code currently is.
One minor comment inline,
Thanks,
Jonathan
> ---
> drivers/iio/adc/fsl-imx25-gcq.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
> index fa71489195c6..3b1e12b7c1ac 100644
> --- a/drivers/iio/adc/fsl-imx25-gcq.c
> +++ b/drivers/iio/adc/fsl-imx25-gcq.c
> @@ -73,8 +73,12 @@ static irqreturn_t mx25_gcq_irq(int irq, void *data)
> {
> struct mx25_gcq_priv *priv = data;
> u32 stats;
> + int ret;
>
> - regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
> + ret = regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
> + if (ret) {
No brackets around a single line block like this.
> + return ret;
> + }
>
> if (stats & MX25_ADCQ_SR_EOQ) {
> regmap_update_bits(priv->regs, MX25_ADCQ_MR,
> @@ -100,6 +104,7 @@ static int mx25_gcq_get_raw_value(struct device *dev,
> {
> long timeout;
> u32 data;
> + int ret;
>
> /* Setup the configuration we want to use */
> regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
> @@ -121,7 +126,11 @@ static int mx25_gcq_get_raw_value(struct device *dev,
> return -ETIMEDOUT;
> }
>
> - regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
> + ret = regmap_read(priv->regs, MX25_ADCQ_FIFO, &data);
> + if (ret) {
> + dev_err(dev, "Failed to read MX25_ADCQ_FIFO.\n");
> + return ret;
> + }
>
> *val = MX25_ADCQ_FIFO_DATA(data);
>
