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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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Andy Shevchenko 2018-02-09 17:38:33 +02:00 committed by Rafael J. Wysocki
parent 7928b2cbe5
commit 4222f38ca3
1 changed files with 38 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
drivers/acpi/bus.c
View File

@ -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;
@ -690,8 +692,11 @@ 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 (id->id[0] && !strcmp((char *) id->id, hwid->id))
return id;
else if (id->cls && __acpi_match_device_cls(id, hwid))
return id;
if (acpi_ids) {
for (id = acpi_ids; id->id[0] || id->cls; id++) {
if (id->id[0] && !strcmp((char *)id->id, hwid->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);