| Message ID | 20190930195358.27844-1-yzhai003@ucr.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: imx25-gcq: fix uninitialized variable usage | expand |
On Mon, 30 Sep 2019 12:53:54 -0700 Yizhuo <yzhai003@ucr.edu> 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@ucr.edu> 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); >
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) { + 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);
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@ucr.edu> --- drivers/iio/adc/fsl-imx25-gcq.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)