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* [PATCH] iio: adc: meson-saradc: Variables could be uninitalized if regmap_read() fails
@ 2019-09-28  0:46 Yizhuo
  2019-09-28  6:47 ` Nicholas Mc Guire
  0 siblings, 1 reply; 5+ messages in thread
From: Yizhuo @ 2019-09-28  0:46 UTC (permalink / raw)
  Cc: csong, Lars-Peter Clausen, Neil Armstrong, Martin Blumenstingl,
	Kevin Hilman, Nicholas Mc Guire, zhiyunq, linux-kernel, Yizhuo,
	linux-iio, linux-arm-kernel, Peter Meerwald-Stadler,
	Hartmut Knaack, linux-amlogic, Thomas Gleixner, Jonathan Cameron

Several functions in this file are trying to use regmap_read() to
initialize the specific variable, however, if regmap_read() fails,
the variable could be uninitialized but used directly, which is
potentially unsafe. The return value of regmap_read() should be
checked and handled.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
 drivers/iio/adc/meson_saradc.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 7b28d045d271..c032a64108b4 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -323,6 +323,7 @@ static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	int regval, timeout = 10000;
+	int ret;
 
 	/*
 	 * NOTE: we need a small delay before reading the status, otherwise
@@ -331,7 +332,9 @@ static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
 	 */
 	do {
 		udelay(1);
-		regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+		ret = regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+		if (ret)
+			return ret;
 	} while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
 
 	if (timeout < 0)
@@ -358,7 +361,11 @@ static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
 		return -EINVAL;
 	}
 
-	regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
+	int ret = regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
+
+	if (ret)
+		return ret;
+
 	fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
 	if (fifo_chan != chan->address) {
 		dev_err(&indio_dev->dev,
@@ -491,6 +498,7 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	int val, timeout = 10000;
+	int ret;
 
 	mutex_lock(&indio_dev->mlock);
 
@@ -506,7 +514,10 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev)
 		 */
 		do {
 			udelay(1);
-			regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
+			ret = regmap_read(priv->regmap,
+					MESON_SAR_ADC_DELAY, &val);
+			if (ret)
+				return ret;
 		} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
 
 		if (timeout < 0) {
@@ -784,7 +795,10 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
 		 * BL30 to make sure BL30 gets the values it expects when
 		 * reading the temperature sensor.
 		 */
-		regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
+		ret = regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
+		if (ret)
+			return ret;
+
 		if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
 			return 0;
 	}
@@ -1014,7 +1028,11 @@ static irqreturn_t meson_sar_adc_irq(int irq, void *data)
 	unsigned int cnt, threshold;
 	u32 regval;
 
-	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+	int ret = regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+
+	if (ret)
+		return ret;
+
 	cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
 	threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
 
-- 
2.17.1


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^ permalink raw reply related	[flat|nested] 5+ messages in thread
* [PATCH] iio: adc: meson-saradc: Variables could be uninitalized if regmap_read() fails
@ 2019-09-29 16:48 Yizhuo
  2019-09-30 21:16 ` Martin Blumenstingl
  0 siblings, 1 reply; 5+ messages in thread
From: Yizhuo @ 2019-09-29 16:48 UTC (permalink / raw)
  Cc: csong, Lars-Peter Clausen, Neil Armstrong, Martin Blumenstingl,
	Kevin Hilman, Nicholas Mc Guire, zhiyunq, Greg Kroah-Hartman,
	linux-kernel, Yizhuo, linux-iio, linux-arm-kernel,
	Peter Meerwald-Stadler, Hartmut Knaack, linux-amlogic,
	Thomas Gleixner, Jonathan Cameron

Several functions in this file are trying to use regmap_read() to
initialize the specific variable, however, if regmap_read() fails,
the variable could be uninitialized but used directly, which is
potentially unsafe. The return value of regmap_read() should be
checked and handled.

Signed-off-by: Yizhuo <yzhai003@ucr.edu>
---
 drivers/iio/adc/meson_saradc.c | 30 ++++++++++++++++++++++++------
 1 file changed, 24 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/adc/meson_saradc.c b/drivers/iio/adc/meson_saradc.c
index 7b28d045d271..4b6c2983ef39 100644
--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -323,6 +323,7 @@ static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	int regval, timeout = 10000;
+	int ret;
 
 	/*
 	 * NOTE: we need a small delay before reading the status, otherwise
@@ -331,7 +332,9 @@ static int meson_sar_adc_wait_busy_clear(struct iio_dev *indio_dev)
 	 */
 	do {
 		udelay(1);
-		regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+		ret = regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+		if (ret)
+			return ret;
 	} while (FIELD_GET(MESON_SAR_ADC_REG0_BUSY_MASK, regval) && timeout--);
 
 	if (timeout < 0)
@@ -346,6 +349,7 @@ static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	int regval, fifo_chan, fifo_val, count;
+	int ret;
 
 	if(!wait_for_completion_timeout(&priv->done,
 				msecs_to_jiffies(MESON_SAR_ADC_TIMEOUT)))
@@ -358,7 +362,10 @@ static int meson_sar_adc_read_raw_sample(struct iio_dev *indio_dev,
 		return -EINVAL;
 	}
 
-	regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
+	ret = regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &regval);
+	if (ret)
+		return ret;
+
 	fifo_chan = FIELD_GET(MESON_SAR_ADC_FIFO_RD_CHAN_ID_MASK, regval);
 	if (fifo_chan != chan->address) {
 		dev_err(&indio_dev->dev,
@@ -491,6 +498,7 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	int val, timeout = 10000;
+	int ret;
 
 	mutex_lock(&indio_dev->mlock);
 
@@ -506,7 +514,10 @@ static int meson_sar_adc_lock(struct iio_dev *indio_dev)
 		 */
 		do {
 			udelay(1);
-			regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
+			ret = regmap_read(priv->regmap,
+						MESON_SAR_ADC_DELAY, &val);
+			if (ret)
+				return ret;
 		} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
 
 		if (timeout < 0) {
@@ -771,7 +782,7 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
 {
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	int regval, i, ret;
-
+	int ret;
 	/*
 	 * make sure we start at CH7 input since the other muxes are only used
 	 * for internal calibration.
@@ -784,7 +795,10 @@ static int meson_sar_adc_init(struct iio_dev *indio_dev)
 		 * BL30 to make sure BL30 gets the values it expects when
 		 * reading the temperature sensor.
 		 */
-		regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
+		ret = regmap_read(priv->regmap, MESON_SAR_ADC_REG3, &regval);
+		if (ret)
+			return ret;
+
 		if (regval & MESON_SAR_ADC_REG3_BL30_INITIALIZED)
 			return 0;
 	}
@@ -1013,8 +1027,12 @@ static irqreturn_t meson_sar_adc_irq(int irq, void *data)
 	struct meson_sar_adc_priv *priv = iio_priv(indio_dev);
 	unsigned int cnt, threshold;
 	u32 regval;
+	int ret;
+
+	ret = regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
+	if (ret)
+		return ret;
 
-	regmap_read(priv->regmap, MESON_SAR_ADC_REG0, &regval);
 	cnt = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_COUNT_MASK, regval);
 	threshold = FIELD_GET(MESON_SAR_ADC_REG0_FIFO_CNT_IRQ_MASK, regval);
 
-- 
2.17.1


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linux-amlogic@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-amlogic

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2019-09-30 21:17 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-28  0:46 [PATCH] iio: adc: meson-saradc: Variables could be uninitalized if regmap_read() fails Yizhuo
2019-09-28  6:47 ` Nicholas Mc Guire
2019-09-29 16:54   ` Yizhuo Zhai
2019-09-29 16:48 Yizhuo
2019-09-30 21:16 ` Martin Blumenstingl

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