diff options
| author | Li Zhong <floridsleeves@gmail.com> | 2022-09-23 17:17:51 -0700 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2022-09-25 14:22:11 -0700 |
| commit | 8887516f01066375d70162a978b3fd9d73695878 (patch) | |
| tree | 03d4397d8274b4a65e778f7ac0e52b4ccf83e7f1 /drivers/hwmon | |
| parent | f9c0cf8f26de367c58e48b02b1cdb9c377626e6f (diff) | |
| download | linux-8887516f01066375d70162a978b3fd9d73695878.tar.bz2 | |
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')
| -rw-r--r-- | drivers/hwmon/adm9240.c | 10 |
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), ®val); - 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]); |