ACPI: convert acpi_device_lock spinlock to mutex
Convert acpi_device_lock to a mutex to avoid
a potential race upon access to /proc/acpi/wakeup
Delete the lock entirely in wakeup.c
since it is not necessary (and can not sleep)
Found-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 20c23c0..e63f2fe 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -24,7 +24,7 @@
static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
-DEFINE_SPINLOCK(acpi_device_lock);
+DEFINE_MUTEX(acpi_device_lock);
LIST_HEAD(acpi_wakeup_device_list);
struct acpi_device_bus_id{
@@ -500,7 +500,7 @@
return -ENOMEM;
}
- spin_lock(&acpi_device_lock);
+ mutex_lock(&acpi_device_lock);
/*
* Find suitable bus_id and instance number in acpi_bus_id_list
* If failed, create one and link it into acpi_bus_id_list
@@ -528,7 +528,7 @@
list_add_tail(&device->g_list, &acpi_device_list);
if (device->wakeup.flags.valid)
list_add_tail(&device->wakeup_list, &acpi_wakeup_device_list);
- spin_unlock(&acpi_device_lock);
+ mutex_unlock(&acpi_device_lock);
if (device->parent)
device->dev.parent = &parent->dev;
@@ -549,20 +549,20 @@
device->removal_type = ACPI_BUS_REMOVAL_NORMAL;
return 0;
end:
- spin_lock(&acpi_device_lock);
+ mutex_lock(&acpi_device_lock);
if (device->parent) {
list_del(&device->node);
list_del(&device->g_list);
} else
list_del(&device->g_list);
list_del(&device->wakeup_list);
- spin_unlock(&acpi_device_lock);
+ mutex_unlock(&acpi_device_lock);
return result;
}
static void acpi_device_unregister(struct acpi_device *device, int type)
{
- spin_lock(&acpi_device_lock);
+ mutex_lock(&acpi_device_lock);
if (device->parent) {
list_del(&device->node);
list_del(&device->g_list);
@@ -570,7 +570,7 @@
list_del(&device->g_list);
list_del(&device->wakeup_list);
- spin_unlock(&acpi_device_lock);
+ mutex_unlock(&acpi_device_lock);
acpi_detach_data(device->handle, acpi_bus_data_handler);