ACPI / Battery: Resolve the race condition in the sysfs_remove_battery()
Use battery->lock in sysfs_remove_battery() to make
checking, removing, and clearing bat.dev atomic.
This is necessary because sysfs_remove_battery() may
be invoked concurrently from different paths.
https://bugzilla.kernel.org/show_bug.cgi?id=35642
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 4ba339d..40bf01d 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -573,11 +573,16 @@
static void sysfs_remove_battery(struct acpi_battery *battery)
{
- if (!battery->bat.dev)
+ mutex_lock(&battery->lock);
+ if (!battery->bat.dev) {
+ mutex_unlock(&battery->lock);
return;
+ }
+
device_remove_file(battery->bat.dev, &alarm_attr);
power_supply_unregister(&battery->bat);
battery->bat.dev = NULL;
+ mutex_unlock(&battery->lock);
}
/*