drv: validate user input

the offset user input is validated; in fa_dac_offset_get() there is a paranoid check; if the offset is still out of range, then there is something big and wrong somewhere. Signed-off-by: Federico Vaga <federico.vaga@cern.ch>

drv: validate user input
the offset user input is validated; in fa_dac_offset_get() there is a paranoid check; if the offset is still out of range, then there is something big and wrong somewhere. Signed-off-by: Federico Vaga <federico.vaga@cern.ch>
3a4fa1c7 · Federico Vaga · b0a46eac · 3a4fa1c7 · 3a4fa1c7 · 3a4fa1c7
Commit 3a4fa1c7 authored Aug 06, 2020 by Federico Vaga
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Showing with 23 additions and 12 deletions

fa-calibration.c kernel/fa-calibration.c +6 -8

fa-zio-drv.c kernel/fa-zio-drv.c +14 -4

fmc-adc-100m14b4cha.h kernel/fmc-adc-100m14b4cha.h +3 -0

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--- a/kernel/fa-calibration.c
+++ b/kernel/fa-calibration.c
@@ -183,20 +183,18 @@ static int64_t fa_dac_offset_raw_calibrate(int32_t raw_offset,
 	return hwval;
 }

-#define DAC_SAT_LOW -5000000
-#define DAC_SAT_UP 5000000
 static int fa_dac_offset_get(struct fa_dev *fa, unsigned int chan)
 {
 	int32_t off_uv = fa->user_offset[chan] + fa->zero_offset[chan];

-	if (off_uv < DAC_SAT_LOW) {
-		dev_warn(&fa->pdev->dev, "DAC lower saturation %d\n",
-			 DAC_SAT_LOW);
+	if (WARN(off_uv < DAC_SAT_LOW,
+		 "DAC lower saturation %d < %d\n",
+		 off_uv, DAC_SAT_LOW)) {
 		off_uv = DAC_SAT_LOW;
 	}
-	if (off_uv > DAC_SAT_UP) {
-		dev_warn(&fa->pdev->dev, "DAC upper saturation %d\n",
-			 DAC_SAT_UP);
+	if (WARN(off_uv > DAC_SAT_UP,
+		 "DAC upper saturation %d > %d\n",
+		 off_uv, DAC_SAT_UP)) {
 		off_uv = DAC_SAT_UP;
 	}


--- a/kernel/fa-zio-drv.c
+++ b/kernel/fa-zio-drv.c
@@ -160,6 +160,12 @@ int zfad_convert_user_range(uint32_t user_val)
 	return zfad_convert_hw_range(user_val);
 }

+static bool fa_is_dac_offset_valid(int32_t user, int32_t zero)
+{
+	int32_t offset = user + zero;
+
+	return (offset >= DAC_SAT_LOW && offset <= DAC_SAT_UP);
+}
 /*
 * zfad_conf_set
 *
@@ -202,13 +208,15 @@ static int zfad_conf_set(struct device *dev, struct zio_attribute *zattr,
 		/*fallthrough*/
 	case ZFA_SW_CH4_OFFSET_ZERO:
 		i--;
-
 		chan = to_zio_cset(dev)->chan + i;
+		if (!fa_is_dac_offset_valid(fa->user_offset[chan->index],
+					    usr_val))
+			return -EINVAL;
 		spin_lock(&fa->zdev->cset->lock);
 		fa->zero_offset[i] = usr_val;
 		spin_unlock(&fa->zdev->cset->lock);
 		fa_calib_dac_config(fa, ~0);
-		return err;
+		return 0;
 	case ZFA_CHx_SAT:
 		/* TODO when TLV */
 		break;
@@ -235,8 +243,10 @@ static int zfad_conf_set(struct device *dev, struct zio_attribute *zattr,
 		/*fallthrough*/
 	case ZFA_CH4_OFFSET:
 		i--;
-
-		chan = to_zio_cset(dev)->chan + i;
+                chan = to_zio_cset(dev)->chan + i;
+                if (!fa_is_dac_offset_valid(usr_val,
+					    fa->zero_offset[chan->index]))
+			return -EINVAL;
 		spin_lock(&fa->zdev->cset->lock);
 		fa->user_offset[chan->index] = usr_val;
 		spin_unlock(&fa->zdev->cset->lock);

--- a/kernel/fmc-adc-100m14b4cha.h
+++ b/kernel/fmc-adc-100m14b4cha.h
@@ -175,6 +175,9 @@ struct fa_calib {
 #define ADC_SPI_OFF 0x1800
 #define ADC_UTC_OFF 0x1900

+#define DAC_SAT_LOW -5000000
+#define DAC_SAT_UP 5000000
+
 extern int fa_enable_test_data_adc;

 #define ADC_DMA 0