ACPI: bus: allow _UID matching for integer zero

Commit b2b32a173881 ("ACPI: bus: update acpi_dev_hid_uid_match() to
support multiple types") added _UID matching support for both integer
and string types, which satisfies NULL @uid2 argument for string types
using inversion, but this logic prevents _UID comparision in case the
argument is integer 0, which may result in false positives.

Fix this using _Generic(), which will allow NULL @uid2 argument for
string types as well as _UID matching for all possible integer values.

Fixes: b2b32a173881 ("ACPI: bus: update acpi_dev_hid_uid_match() to support multiple types")
Signed-off-by: Raag Jadav <raag.jadav@intel.com>
[ rjw: Comment adjustment ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 5de954e2b18aaac5c0796466d256f6cd10e1130d..e7796f373d0dac4daa5c322a7ba82983b9a8ac81 100644 (file)
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -911,17 +911,19 @@ static inline bool acpi_int_uid_match(struct acpi_device *adev, u64 uid2)
  * acpi_dev_hid_uid_match - Match device by supplied HID and UID
  * @adev: ACPI device to match.
  * @hid2: Hardware ID of the device.
- * @uid2: Unique ID of the device, pass 0 or NULL to not check _UID.
+ * @uid2: Unique ID of the device, pass NULL to not check _UID.
  *
  * Matches HID and UID in @adev with given @hid2 and @uid2. Absence of @uid2
  * will be treated as a match. If user wants to validate @uid2, it should be
  * done before calling this function.
  *
- * Returns: %true if matches or @uid2 is 0 or NULL, %false otherwise.
+ * Returns: %true if matches or @uid2 is NULL, %false otherwise.
  */
 #define acpi_dev_hid_uid_match(adev, hid2, uid2)                       \
        (acpi_dev_hid_match(adev, hid2) &&                              \
-               (!(uid2) || acpi_dev_uid_match(adev, uid2)))
+               /* Distinguish integer 0 from NULL @uid2 */             \
+               (_Generic(uid2, ACPI_STR_TYPES(!(uid2)), default: 0) || \
+               acpi_dev_uid_match(adev, uid2)))
 
 void acpi_dev_clear_dependencies(struct acpi_device *supplier);
 bool acpi_dev_ready_for_enumeration(const struct acpi_device *device);