hwmon: (f71882fg) Fix various sysfs callback function issues

While working on adding F8000 support I noticed that various of the
store sysfs functions (and a few of the show also) had issues.

This patch fixes the following issues in these functions:
* store: storing the result of strto[u]l in an int, resulting in a possible
  overflow before boundary checking
* store: use of f71882fg_update_device(), we don't want to read the whole
  device in store functions, just the registers we need
* store: use of cached register values instead of reading the needed regs
  in the store function, including cases where f71882fg_update_device() was
  not used, this could cause real isues
* show: shown value is a calculation of 2 or more cached register reads,
  without locking the data struct.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 73 insertions, 49 deletions

diff --git a/drivers/hwmon/f71882fg.c b/drivers/hwmon/f71882fg.c
index 2604c6d7ea58..345f465aa288 100644
--- a/drivers/hwmon/f71882fg.c
+++ b/drivers/hwmon/f71882fg.c
@@ -835,6 +835,7 @@ static ssize_t store_fan_full_speed(struct device *dev,
         val = fan_to_reg(val);
 
         mutex_lock(&data->update_lock);
+        data->pwm_enable = f71882fg_read8(data, F71882FG_REG_PWM_ENABLE);
         if (data->pwm_enable & (1 << (2 * nr)))
                 /* PWM mode */
                 count = -EINVAL;
@@ -865,9 +866,10 @@ static ssize_t store_fan_beep(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10);
+        unsigned long val = simple_strtoul(buf, NULL, 10);
 
         mutex_lock(&data->update_lock);
+        data->fan_beep = f71882fg_read8(data, F71882FG_REG_FAN_BEEP);
         if (val)
                 data->fan_beep |= 1 << nr;
         else
@@ -912,10 +914,8 @@ static ssize_t store_in_max(struct device *dev, struct device_attribute
         *devattr, const char *buf, size_t count)
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
-        int val = simple_strtoul(buf, NULL, 10) / 8;
-
-        if (val > 255)
-                val = 255;
+        long val = simple_strtol(buf, NULL, 10) / 8;
+        val = SENSORS_LIMIT(val, 0, 255);
 
         mutex_lock(&data->update_lock);
         f71882fg_write8(data, F71882FG_REG_IN1_HIGH, val);
@@ -942,9 +942,10 @@ static ssize_t store_in_beep(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10);
+        unsigned long val = simple_strtoul(buf, NULL, 10);
 
         mutex_lock(&data->update_lock);
+        data->in_beep = f71882fg_read8(data, F71882FG_REG_IN_BEEP);
         if (val)
                 data->in_beep |= 1 << nr;
         else
@@ -991,10 +992,8 @@ static ssize_t store_temp_max(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10) / 1000;
-
-        if (val > 255)
-                val = 255;
+        long val = simple_strtol(buf, NULL, 10) / 1000;
+        val = SENSORS_LIMIT(val, 0, 255);
 
         mutex_lock(&data->update_lock);
         f71882fg_write8(data, F71882FG_REG_TEMP_HIGH(nr), val);
@@ -1009,9 +1008,13 @@ static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = f71882fg_update_device(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
+        int temp_max_hyst;
 
-        return sprintf(buf, "%d\n",
-                (data->temp_high[nr] - data->temp_hyst[nr]) * 1000);
+        mutex_lock(&data->update_lock);
+        temp_max_hyst = (data->temp_high[nr] - data->temp_hyst[nr]) * 1000;
+        mutex_unlock(&data->update_lock);
+
+        return sprintf(buf, "%d\n", temp_max_hyst);
 }
 
 static ssize_t store_temp_max_hyst(struct device *dev, struct device_attribute
@@ -1019,37 +1022,38 @@ static ssize_t store_temp_max_hyst(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10) / 1000;
+        long val = simple_strtol(buf, NULL, 10) / 1000;
         ssize_t ret = count;
+        u8 reg;
 
         mutex_lock(&data->update_lock);
 
         /* convert abs to relative and check */
+        data->temp_high[nr] = f71882fg_read8(data, F71882FG_REG_TEMP_HIGH(nr));
+        val = SENSORS_LIMIT(val, data->temp_high[nr] - 15,
+                            data->temp_high[nr]);
         val = data->temp_high[nr] - val;
-        if (val < 0 || val > 15) {
-                ret = -EINVAL;
-                goto store_temp_max_hyst_exit;
-        }
-
         data->temp_hyst[nr] = val;
 
         /* convert value to register contents */
         switch (nr) {
                 case 1:
-                        val = val << 4;
+                        reg = f71882fg_read8(data, F71882FG_REG_TEMP_HYST1);
+                        reg = (reg & 0x0f) | (val << 4);
                         break;
                 case 2:
-                        val = val | (data->temp_hyst[3] << 4);
+                        reg = f71882fg_read8(data, F71882FG_REG_TEMP_HYST23);
+                        reg = (reg & 0xf0) | val;
                         break;
                 case 3:
-                        val = data->temp_hyst[2] | (val << 4);
+                        reg = f71882fg_read8(data, F71882FG_REG_TEMP_HYST23);
+                        reg = (reg & 0x0f) | (val << 4);
                         break;
         }
 
         f71882fg_write8(data, (nr <= 1) ? F71882FG_REG_TEMP_HYST1 :
-                F71882FG_REG_TEMP_HYST23, val);
+                F71882FG_REG_TEMP_HYST23, reg);
 
-store_temp_max_hyst_exit:
         mutex_unlock(&data->update_lock);
         return ret;
 }
@@ -1068,10 +1072,8 @@ static ssize_t store_temp_crit(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10) / 1000;
-
-        if (val > 255)
-                val = 255;
+        long val = simple_strtol(buf, NULL, 10) / 1000;
+        val = SENSORS_LIMIT(val, 0, 255);
 
         mutex_lock(&data->update_lock);
         f71882fg_write8(data, F71882FG_REG_TEMP_OVT(nr), val);
@@ -1086,9 +1088,13 @@ static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = f71882fg_update_device(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
+        int temp_crit_hyst;
 
-        return sprintf(buf, "%d\n",
-                (data->temp_ovt[nr] - data->temp_hyst[nr]) * 1000);
+        mutex_lock(&data->update_lock);
+        temp_crit_hyst = (data->temp_ovt[nr] - data->temp_hyst[nr]) * 1000;
+        mutex_unlock(&data->update_lock);
+
+        return sprintf(buf, "%d\n", temp_crit_hyst);
 }
 
 static ssize_t show_temp_type(struct device *dev, struct device_attribute
@@ -1117,9 +1123,10 @@ static ssize_t store_temp_beep(struct device *dev, struct device_attribute
 {
         struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10);
+        unsigned long val = simple_strtoul(buf, NULL, 10);
 
         mutex_lock(&data->update_lock);
+        data->temp_beep = f71882fg_read8(data, F71882FG_REG_TEMP_BEEP);
         if (val)
                 data->temp_beep |= 1 << nr;
         else
@@ -1160,16 +1167,16 @@ static ssize_t show_pwm(struct device *dev,
 {
         struct f71882fg_data *data = f71882fg_update_device(dev);
         int val, nr = to_sensor_dev_attr_2(devattr)->index;
+        mutex_lock(&data->update_lock);
         if (data->pwm_enable & (1 << (2 * nr)))
                 /* PWM mode */
                 val = data->pwm[nr];
         else {
                 /* RPM mode */
-                mutex_lock(&data->update_lock);
                 val = 255 * fan_from_reg(data->fan_target[nr])
                         / fan_from_reg(data->fan_full_speed[nr]);
-                mutex_unlock(&data->update_lock);
         }
+        mutex_unlock(&data->update_lock);
         return sprintf(buf, "%d\n", val);
 }
 
@@ -1177,23 +1184,26 @@ static ssize_t store_pwm(struct device *dev,
                          struct device_attribute *devattr, const char *buf,
                          size_t count)
 {
-        /* struct f71882fg_data *data = dev_get_drvdata(dev); */
-        struct f71882fg_data *data = f71882fg_update_device(dev);
+        struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
         long val = simple_strtol(buf, NULL, 10);
         val = SENSORS_LIMIT(val, 0, 255);
 
         mutex_lock(&data->update_lock);
+        data->pwm_enable = f71882fg_read8(data, F71882FG_REG_PWM_ENABLE);
         if (data->pwm_enable & (1 << (2 * nr))) {
                 /* PWM mode */
                 f71882fg_write8(data, F71882FG_REG_PWM(nr), val);
                 data->pwm[nr] = val;
         } else {
                 /* RPM mode */
-                int target = val * fan_from_reg(data->fan_full_speed[nr]) / 255;
-                f71882fg_write16(data, F71882FG_REG_FAN_TARGET(nr),
-                                 fan_to_reg(target));
-                data->fan_target[nr] = fan_to_reg(target);
+                int target, full_speed;
+                full_speed = f71882fg_read16(data,
+                                             F71882FG_REG_FAN_FULL_SPEED(nr));
+                target = fan_to_reg(val * fan_from_reg(full_speed) / 255);
+                f71882fg_write16(data, F71882FG_REG_FAN_TARGET(nr), target);
+                data->fan_target[nr] = target;
+                data->fan_full_speed[nr] = full_speed;
         }
         mutex_unlock(&data->update_lock);
 
@@ -1225,6 +1235,7 @@ static ssize_t store_pwm_enable(struct device *dev, struct device_attribute
                 return -EINVAL;
 
         mutex_lock(&data->update_lock);
+        data->pwm_enable = f71882fg_read8(data, F71882FG_REG_PWM_ENABLE);
         switch (val) {
         case 1:
                 data->pwm_enable |= 2 << (2 * nr);
@@ -1258,6 +1269,7 @@ static ssize_t show_pwm_auto_point_pwm(struct device *dev,
         int pwm = to_sensor_dev_attr_2(devattr)->index;
         int point = to_sensor_dev_attr_2(devattr)->nr;
 
+        mutex_lock(&data->update_lock);
         if (data->pwm_enable & (1 << (2 * pwm))) {
                 /* PWM mode */
                 result = data->pwm_auto_point_pwm[pwm][point];
@@ -1265,6 +1277,7 @@ static ssize_t show_pwm_auto_point_pwm(struct device *dev,
                 /* RPM mode */
                 result = 32 * 255 / (32 + data->pwm_auto_point_pwm[pwm][point]);
         }
+        mutex_unlock(&data->update_lock);
 
         return sprintf(buf, "%d\n", result);
 }
@@ -1273,14 +1286,14 @@ static ssize_t store_pwm_auto_point_pwm(struct device *dev,
                                         struct device_attribute *devattr,
                                         const char *buf, size_t count)
 {
-        /* struct f71882fg_data *data = dev_get_drvdata(dev); */
-        struct f71882fg_data *data = f71882fg_update_device(dev);
+        struct f71882fg_data *data = dev_get_drvdata(dev);
         int pwm = to_sensor_dev_attr_2(devattr)->index;
         int point = to_sensor_dev_attr_2(devattr)->nr;
-        int val = simple_strtoul(buf, NULL, 10);
+        long val = simple_strtol(buf, NULL, 10);
         val = SENSORS_LIMIT(val, 0, 255);
 
         mutex_lock(&data->update_lock);
+        data->pwm_enable = f71882fg_read8(data, F71882FG_REG_PWM_ENABLE);
         if (data->pwm_enable & (1 << (2 * pwm))) {
                 /* PWM mode */
         } else {
@@ -1331,16 +1344,25 @@ static ssize_t store_pwm_auto_point_temp_hyst(struct device *dev,
                                               struct device_attribute *devattr,
                                               const char *buf, size_t count)
 {
-        struct f71882fg_data *data = f71882fg_update_device(dev);
+        struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
         int point = to_sensor_dev_attr_2(devattr)->nr;
         long val = simple_strtol(buf, NULL, 10) / 1000;
 
         mutex_lock(&data->update_lock);
+        data->pwm_auto_point_temp[nr][point] =
+                f71882fg_read8(data, F71882FG_REG_POINT_TEMP(nr, point));
         val = SENSORS_LIMIT(val, data->pwm_auto_point_temp[nr][point] - 15,
                                 data->pwm_auto_point_temp[nr][point]);
         val = data->pwm_auto_point_temp[nr][point] - val;
 
+        if (nr == 0 || nr == 1) {
+                data->pwm_auto_point_hyst[0] =
+                        f71882fg_read8(data, F71882FG_REG_FAN_HYST0);
+        } else {
+                data->pwm_auto_point_hyst[1] =
+                        f71882fg_read8(data, F71882FG_REG_FAN_HYST1);
+        }
         switch (nr) {
         case 0:
                 val = (data->pwm_auto_point_hyst[0] & 0xf0) | val;
@@ -1383,11 +1405,13 @@ static ssize_t store_pwm_interpolate(struct device *dev,
                                      struct device_attribute *devattr,
                                      const char *buf, size_t count)
 {
-        /* struct f71882fg_data *data = dev_get_drvdata(dev); */
-        struct f71882fg_data *data = f71882fg_update_device(dev);
+        struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
-        int val = simple_strtoul(buf, NULL, 10);
+        unsigned long val = simple_strtoul(buf, NULL, 10);
+
         mutex_lock(&data->update_lock);
+        data->pwm_auto_point_mapping[nr] =
+                f71882fg_read8(data, F71882FG_REG_POINT_MAPPING(nr));
         if (val)
                 val = data->pwm_auto_point_mapping[nr] | (1 << 4);
         else
@@ -1416,8 +1440,7 @@ static ssize_t store_pwm_auto_point_channel(struct device *dev,
                                             struct device_attribute *devattr,
                                             const char *buf, size_t count)
 {
-        /* struct f71882fg_data *data = dev_get_drvdata(dev); */
-        struct f71882fg_data *data = f71882fg_update_device(dev);
+        struct f71882fg_data *data = dev_get_drvdata(dev);
         int nr = to_sensor_dev_attr_2(devattr)->index;
         long val = simple_strtol(buf, NULL, 10);
         switch (val) {
@@ -1434,6 +1457,8 @@ static ssize_t store_pwm_auto_point_channel(struct device *dev,
                 return -EINVAL;
         }
         mutex_lock(&data->update_lock);
+        data->pwm_auto_point_mapping[nr] =
+                f71882fg_read8(data, F71882FG_REG_POINT_MAPPING(nr));
         val = (data->pwm_auto_point_mapping[nr] & 0xfc) | val;
         f71882fg_write8(data, F71882FG_REG_POINT_MAPPING(nr), val);
         data->pwm_auto_point_mapping[nr] = val;
@@ -1459,8 +1484,7 @@ static ssize_t store_pwm_auto_point_temp(struct device *dev,
                                          struct device_attribute *devattr,
                                          const char *buf, size_t count)
 {
-        /* struct f71882fg_data *data = dev_get_drvdata(dev); */
-        struct f71882fg_data *data = f71882fg_update_device(dev);
+        struct f71882fg_data *data = dev_get_drvdata(dev);
         int pwm = to_sensor_dev_attr_2(devattr)->index;
         int point = to_sensor_dev_attr_2(devattr)->nr;
         long val = simple_strtol(buf, NULL, 10) / 1000;