Commit 2c59a32d authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Guenter Roeck
Browse files

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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/11871063.O9o76ZdvQC@kreacher


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent b1986c8e

drivers/acpi/scan.c

+1 −0
Original line number Diff line number Diff line
@@ -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)

{

drivers/hwmon/acpi_power_meter.c

+5 −8
Original line number Diff line number Diff line
@@ -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;

		}

	}