power_supply: Use wrappers to avoid races when registering power supply
Use wrappers over get_property() and set_property() internally in power
supply and for sysfs interface. The wrappers provide safe access if
power supply is not yet registered or t is being destroyed.
In case of syfs the theoretical race could happen between ending of
driver's probe and parallel sysfs access:
some_driver_probe() userspace
==================================== ===========================
drv->psy = power_supply_register()
device_add()
sysfs entries are created
atomic_inc(&psy->use_cnt);
store on sysfs attributes
drv->set_property()
dereference of drv->psy
drv->psy = returned psy;
For leds the race could happen between power supply being destroyed and
ongoing power_supply_changed_work().
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>
diff --git a/drivers/power/power_supply_leds.c b/drivers/power/power_supply_leds.c
index 2d41a43..2277ad9 100644
--- a/drivers/power/power_supply_leds.c
+++ b/drivers/power/power_supply_leds.c
@@ -25,7 +25,7 @@
unsigned long delay_on = 0;
unsigned long delay_off = 0;
- if (psy->desc->get_property(psy, POWER_SUPPLY_PROP_STATUS, &status))
+ if (power_supply_get_property(psy, POWER_SUPPLY_PROP_STATUS, &status))
return;
dev_dbg(&psy->dev, "%s %d\n", __func__, status.intval);
@@ -115,7 +115,7 @@
{
union power_supply_propval online;
- if (psy->desc->get_property(psy, POWER_SUPPLY_PROP_ONLINE, &online))
+ if (power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE, &online))
return;
dev_dbg(&psy->dev, "%s %d\n", __func__, online.intval);