Commit 4222f38c authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Rafael J. Wysocki
Browse files

ACPI / bus: Do not traverse through non-existed device table 



When __acpi_match_device() is called it would be possible to have
ACPI ID table a NULL pointer. To avoid potential dereference,
check for this before traverse.

While here, remove redundant 'else'.

Note, this patch implies a bit of refactoring acpi_of_match_device()
to return pointer to OF ID when matched followed by refactoring
__acpi_match_device() to return either ACPI or OF ID when matches.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7928b2cb

drivers/acpi/bus.c

+38 −25
Original line number Diff line number Diff line
@@ -660,13 +660,15 @@ struct acpi_device *acpi_companion_match(const struct device *dev) 
 * acpi_of_match_device - Match device object using the "compatible" property.

 * @adev: ACPI device object to match.

 * @of_match_table: List of device IDs to match against.

 * @of_id: OF ID if matched

 *

 * If @dev has an ACPI companion which has ACPI_DT_NAMESPACE_HID in its list of

 * identifiers and a _DSD object with the "compatible" property, use that

 * property to match against the given list of identifiers.

 */

static bool acpi_of_match_device(struct acpi_device *adev,

				 const struct of_device_id *of_match_table)

				 const struct of_device_id *of_match_table,

				 const struct of_device_id **of_id)

{

	const union acpi_object *of_compatible, *obj;

	int i, nval;
@@ -690,9 +692,12 @@ static bool acpi_of_match_device(struct acpi_device *adev, 
		const struct of_device_id *id;



		for (id = of_match_table; id->compatible[0]; id++)

			if (!strcasecmp(obj->string.pointer, id->compatible))

			if (!strcasecmp(obj->string.pointer, id->compatible)) {

				if (of_id)

					*of_id = id;

				return true;

			}

	}



	return false;

}
@@ -762,10 +767,11 @@ static bool __acpi_match_device_cls(const struct acpi_device_id *id, 
	return true;

}



static const struct acpi_device_id *__acpi_match_device(

	struct acpi_device *device,

	const struct acpi_device_id *ids,

	const struct of_device_id *of_ids)

static bool __acpi_match_device(struct acpi_device *device,

				const struct acpi_device_id *acpi_ids,

				const struct of_device_id *of_ids,

				const struct acpi_device_id **acpi_id,

				const struct of_device_id **of_id)

{

	const struct acpi_device_id *id;

	struct acpi_hardware_id *hwid;
@@ -775,30 +781,32 @@ static const struct acpi_device_id *__acpi_match_device( 
	 * driver for it.

	 */

	if (!device || !device->status.present)

		return NULL;

		return false;



	list_for_each_entry(hwid, &device->pnp.ids, list) {

		/* First, check the ACPI/PNP IDs provided by the caller. */

		for (id = ids; id->id[0] || id->cls; id++) {

		if (acpi_ids) {

			for (id = acpi_ids; id->id[0] || id->cls; id++) {

				if (id->id[0] && !strcmp((char *)id->id, hwid->id))

				return id;

			else if (id->cls && __acpi_match_device_cls(id, hwid))

				return id;

					goto out_acpi_match;

				if (id->cls && __acpi_match_device_cls(id, hwid))

					goto out_acpi_match;

			}

		}



		/*

		 * Next, check ACPI_DT_NAMESPACE_HID and try to match the

		 * "compatible" property if found.

		 *

		 * The id returned by the below is not valid, but the only

		 * caller passing non-NULL of_ids here is only interested in

		 * whether or not the return value is NULL.

		 */

		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id)

		    && acpi_of_match_device(device, of_ids))

			return id;

		if (!strcmp(ACPI_DT_NAMESPACE_HID, hwid->id))

			return acpi_of_match_device(device, of_ids, of_id);

	}

	return NULL;

	return false;



out_acpi_match:

	if (acpi_id)

		*acpi_id = id;

	return true;

}



/**
@@ -815,7 +823,10 @@ static const struct acpi_device_id *__acpi_match_device( 
const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,

					       const struct device *dev)

{

	return __acpi_match_device(acpi_companion_match(dev), ids, NULL);

	const struct acpi_device_id *id = NULL;



	__acpi_match_device(acpi_companion_match(dev), ids, NULL, &id, NULL);

	return id;

}

EXPORT_SYMBOL_GPL(acpi_match_device);
@@ -840,7 +851,7 @@ EXPORT_SYMBOL_GPL(acpi_get_match_data); 
int acpi_match_device_ids(struct acpi_device *device,

			  const struct acpi_device_id *ids)

{

	return __acpi_match_device(device, ids, NULL) ? 0 : -ENOENT;

	return __acpi_match_device(device, ids, NULL, NULL, NULL) ? 0 : -ENOENT;

}

EXPORT_SYMBOL(acpi_match_device_ids);
@@ -849,10 +860,12 @@ bool acpi_driver_match_device(struct device *dev, 
{

	if (!drv->acpi_match_table)

		return acpi_of_match_device(ACPI_COMPANION(dev),

					    drv->of_match_table);

					    drv->of_match_table,

					    NULL);



	return !!__acpi_match_device(acpi_companion_match(dev),

				     drv->acpi_match_table, drv->of_match_table);

	return __acpi_match_device(acpi_companion_match(dev),

				   drv->acpi_match_table, drv->of_match_table,

				   NULL, NULL);

}

EXPORT_SYMBOL_GPL(acpi_driver_match_device);

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