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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2018-02-09 18:38:33 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2018-02-12 12:41:09 +0300
commit4222f38ca3b7ae30ace582077677cec8b88fac36 (patch)
tree505249ffae6f4b77276b96a3f020aa9f64e3ffb1 /drivers/acpi/bus.c
parent7928b2cbe55b2a410a0f5c1f154610059c57b1b2 (diff)
downloadlinux-4222f38ca3b7ae30ace582077677cec8b88fac36.tar.xz
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>
Diffstat (limited to 'drivers/acpi/bus.c')
-rw-r--r--drivers/acpi/bus.c63
1 files changed, 38 insertions, 25 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 676c9788e1c8..f1384e107eed 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -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);