• Krzysztof Kozlowski's avatar
    power_supply: Use wrappers to avoid races when registering power supply · a9f6a19b
    Krzysztof Kozlowski authored
    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: default avatarKrzysztof Kozlowski <k.kozlowski@samsung.com>
    Signed-off-by: default avatarSebastian Reichel <sre@kernel.org>
    a9f6a19b
power_supply_leds.c 4.75 KB