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authorLi Zhong <floridsleeves@gmail.com>2022-09-24 02:17:51 +0200
committerGuenter Roeck <linux@roeck-us.net>2022-09-25 23:22:11 +0200
commit8887516f01066375d70162a978b3fd9d73695878 (patch)
tree03d4397d8274b4a65e778f7ac0e52b4ccf83e7f1 /drivers/hwmon/adm9240.c
parenthwmon: (sht4x) do not overflow clamping operation on 32-bit platforms (diff)
downloadlinux-8887516f01066375d70162a978b3fd9d73695878.tar.xz
linux-8887516f01066375d70162a978b3fd9d73695878.zip
hwmon: (adm9240) fix data race in adm9240_fan_read
In adm9240_read() adm9240_fan_read() adm9240_write_fan_div(), it assumes that the caller of adm9240_write_fan_div() must hold data->update_lock. Otherwise, it may cause data races when data is updated by other threads. Signed-off-by: Li Zhong <floridsleeves@gmail.com> Link: https://lore.kernel.org/r/20220924001751.1726369-1-floridsleeves@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/adm9240.c')
-rw-r--r--drivers/hwmon/adm9240.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/hwmon/adm9240.c b/drivers/hwmon/adm9240.c
index 483cd757abd3..40e3558d3709 100644
--- a/drivers/hwmon/adm9240.c
+++ b/drivers/hwmon/adm9240.c
@@ -501,17 +501,23 @@ static int adm9240_fan_read(struct device *dev, u32 attr, int channel, long *val
switch (attr) {
case hwmon_fan_input:
+ mutex_lock(&data->update_lock);
err = regmap_read(data->regmap, ADM9240_REG_FAN(channel), &regval);
- if (err < 0)
+ if (err < 0) {
+ mutex_unlock(&data->update_lock);
return err;
+ }
if (regval == 255 && data->fan_div[channel] < 3) {
/* adjust fan clock divider on overflow */
err = adm9240_write_fan_div(data, channel,
++data->fan_div[channel]);
- if (err)
+ if (err) {
+ mutex_unlock(&data->update_lock);
return err;
+ }
}
*val = FAN_FROM_REG(regval, BIT(data->fan_div[channel]));
+ mutex_unlock(&data->update_lock);
break;
case hwmon_fan_div:
*val = BIT(data->fan_div[channel]);