Concurrent accesses through sysfs may lead to inconsistent state in the priv data. Introduce a mutex to avoid this.
Fixes: c6ed48ef5259 ("power: supply: add ChromeOS EC based charge control driver") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- drivers/power/supply/cros_charge-control.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c index 17c53591ce197d08d97c94d3d4359a282026dd7d..58ca6d9ed6132af63a36ea4c5bf212acf066936c 100644 --- a/drivers/power/supply/cros_charge-control.c +++ b/drivers/power/supply/cros_charge-control.c @@ -7,8 +7,10 @@ #include <acpi/battery.h> #include <linux/container_of.h> #include <linux/dmi.h> +#include <linux/lockdep.h> #include <linux/mod_devicetable.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/platform_data/cros_ec_commands.h> #include <linux/platform_data/cros_ec_proto.h> #include <linux/platform_device.h> @@ -49,6 +51,7 @@ struct cros_chctl_priv { struct attribute *attributes[_CROS_CHCTL_ATTR_COUNT]; struct attribute_group group;
+ struct mutex lock; /* protects fields below and cros_ec */ enum power_supply_charge_behaviour current_behaviour; u8 current_start_threshold, current_end_threshold; }; @@ -85,6 +88,8 @@ static int cros_chctl_configure_ec(struct cros_chctl_priv *priv) { struct ec_params_charge_control req = {};
+ lockdep_assert_held(&priv->lock); + req.cmd = EC_CHARGE_CONTROL_CMD_SET;
switch (priv->current_behaviour) { @@ -159,6 +164,7 @@ static ssize_t charge_control_start_threshold_show(struct device *dev, struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr, CROS_CHCTL_ATTR_START_THRESHOLD);
+ guard(mutex)(&priv->lock); return sysfs_emit(buf, "%u\n", (unsigned int)priv->current_start_threshold); }
@@ -169,6 +175,7 @@ static ssize_t charge_control_start_threshold_store(struct device *dev, struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr, CROS_CHCTL_ATTR_START_THRESHOLD);
+ guard(mutex)(&priv->lock); return cros_chctl_store_threshold(dev, priv, 0, buf, count); }
@@ -178,6 +185,7 @@ static ssize_t charge_control_end_threshold_show(struct device *dev, struct devi struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr, CROS_CHCTL_ATTR_END_THRESHOLD);
+ guard(mutex)(&priv->lock); return sysfs_emit(buf, "%u\n", (unsigned int)priv->current_end_threshold); }
@@ -187,6 +195,7 @@ static ssize_t charge_control_end_threshold_store(struct device *dev, struct dev struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr, CROS_CHCTL_ATTR_END_THRESHOLD);
+ guard(mutex)(&priv->lock); return cros_chctl_store_threshold(dev, priv, 1, buf, count); }
@@ -195,6 +204,7 @@ static ssize_t charge_behaviour_show(struct device *dev, struct device_attribute struct cros_chctl_priv *priv = cros_chctl_attr_to_priv(&attr->attr, CROS_CHCTL_ATTR_CHARGE_BEHAVIOUR);
+ guard(mutex)(&priv->lock); return power_supply_charge_behaviour_show(dev, EC_CHARGE_CONTROL_BEHAVIOURS, priv->current_behaviour, buf); } @@ -210,6 +220,7 @@ static ssize_t charge_behaviour_store(struct device *dev, struct device_attribut if (ret < 0) return ret;
+ guard(mutex)(&priv->lock); priv->current_behaviour = ret;
ret = cros_chctl_configure_ec(priv); @@ -290,6 +301,10 @@ static int cros_chctl_probe(struct platform_device *pdev) if (!priv) return -ENOMEM;
+ ret = devm_mutex_init(dev, &priv->lock); + if (ret) + return ret; + ret = cros_ec_get_cmd_versions(cros_ec, EC_CMD_CHARGE_CONTROL); if (ret < 0) return ret; @@ -327,7 +342,8 @@ static int cros_chctl_probe(struct platform_device *pdev) priv->current_end_threshold = 100;
/* Bring EC into well-known state */ - ret = cros_chctl_configure_ec(priv); + scoped_guard(mutex, &priv->lock) + ret = cros_chctl_configure_ec(priv); if (ret < 0) return ret;