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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-10-13 19:04:09 +0300
committerGuenter Roeck <linux@roeck-us.net>2021-10-17 08:41:25 +0300
commit2c59a32d12201b4aeaef5c0cc04698670e164dc3 (patch)
tree3a8c28b92063a792eda33a41df3df2c73ee21330 /drivers
parentb1986c8e31a3e5f119a52aab50234fc65cf01f30 (diff)
downloadlinux-2c59a32d12201b4aeaef5c0cc04698670e164dc3.tar.xz
hwmon: (acpi_power_meter) Use acpi_bus_get_acpi_device()
In read_domain_devices(), acpi_bus_get_device() is called to obtain the ACPI device object attached to the given ACPI handle and subsequently that object is passed to get_device() for reference counting, but there is a window between the acpi_bus_get_device() and get_device() calls in which the ACPI device object in question may go away. To address this issue, make read_domain_devices() use acpi_bus_get_acpi_device() to reference count and return the given ACPI device object in one go and export that function to modules. While at it, also make read_domain_devices() and remove_domain_devices() use acpi_dev_put() instead of calling put_device() directly on the ACPI device objects returned by acpi_bus_get_acpi_device(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/11871063.O9o76ZdvQC@kreacher Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/acpi/scan.c1
-rw-r--r--drivers/hwmon/acpi_power_meter.c13
2 files changed, 6 insertions, 8 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 5b54c80b9d32..f456ba7c1060 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -608,6 +608,7 @@ struct acpi_device *acpi_bus_get_acpi_device(acpi_handle handle)
{
return handle_to_device(handle, get_acpi_device);
}
+EXPORT_SYMBOL_GPL(acpi_bus_get_acpi_device);
static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id)
{
diff --git a/drivers/hwmon/acpi_power_meter.c b/drivers/hwmon/acpi_power_meter.c
index 014505b1faf7..c405a5869581 100644
--- a/drivers/hwmon/acpi_power_meter.c
+++ b/drivers/hwmon/acpi_power_meter.c
@@ -535,7 +535,7 @@ static void remove_domain_devices(struct acpi_power_meter_resource *resource)
sysfs_remove_link(resource->holders_dir,
kobject_name(&obj->dev.kobj));
- put_device(&obj->dev);
+ acpi_dev_put(obj);
}
kfree(resource->domain_devices);
@@ -597,18 +597,15 @@ static int read_domain_devices(struct acpi_power_meter_resource *resource)
continue;
/* Create a symlink to domain objects */
- resource->domain_devices[i] = NULL;
- if (acpi_bus_get_device(element->reference.handle,
- &resource->domain_devices[i]))
+ obj = acpi_bus_get_acpi_device(element->reference.handle);
+ resource->domain_devices[i] = obj;
+ if (!obj)
continue;
- obj = resource->domain_devices[i];
- get_device(&obj->dev);
-
res = sysfs_create_link(resource->holders_dir, &obj->dev.kobj,
kobject_name(&obj->dev.kobj));
if (res) {
- put_device(&obj->dev);
+ acpi_dev_put(obj);
resource->domain_devices[i] = NULL;
}
}