ACPI fixes for 5.14-rc3

- Fix recently broken Kconfig dependency for the ACPI table
    override via built-in initrd (Robert Richter).
 
  - Fix ACPI device reference counting in the for_each_acpi_dev_match()
    helper macro to avoid use-after-free (Andy Shevchenko).
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Merge tag 'acpi-5.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI fixes from Rafael Wysocki:
 "These fix a recently broken Kconfig dependency and ACPI device
  reference counting in an iterator macro.

  Specifics:

   - Fix recently broken Kconfig dependency for the ACPI table override
     via built-in initrd (Robert Richter)

   - Fix ACPI device reference counting in the for_each_acpi_dev_match()
     helper macro to avoid use-after-free (Andy Shevchenko)"

* tag 'acpi-5.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI: utils: Fix reference counting in for_each_acpi_dev_match()
  ACPI: Kconfig: Fix table override from built-in initrd

drivers/acpi/Kconfig

@@ -370,7 +370,7 @@ config ACPI_TABLE_UPGRADE
 config ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD
 	bool "Override ACPI tables from built-in initrd"
 	depends on ACPI_TABLE_UPGRADE
-	depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION=""
+	depends on INITRAMFS_SOURCE!="" && INITRAMFS_COMPRESSION_NONE
 	help
 	  This option provides functionality to override arbitrary ACPI tables
 	  from built-in uncompressed initrd.

drivers/acpi/utils.c

@@ -860,11 +860,9 @@ EXPORT_SYMBOL(acpi_dev_present);
  * Return the next match of ACPI device if another matching device was present
  * at the moment of invocation, or NULL otherwise.
  *
- * FIXME: The function does not tolerate the sudden disappearance of @adev, e.g.
- * in the case of a hotplug event. That said, the caller should ensure that
- * this will never happen.
- *
  * The caller is responsible for invoking acpi_dev_put() on the returned device.
+ * On the other hand the function invokes  acpi_dev_put() on the given @adev
+ * assuming that its reference counter had been increased beforehand.
  *
  * See additional information in acpi_dev_present() as well.
  */
@@ -880,6 +878,7 @@ acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const cha
 	match.hrv = hrv;
 
 	dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
+	acpi_dev_put(adev);
 	return dev ? to_acpi_device(dev) : NULL;
 }
 EXPORT_SYMBOL(acpi_dev_get_next_match_dev);

drivers/firmware/efi/dev-path-parser.c

@@ -34,7 +34,6 @@ static long __init parse_acpi_path(const struct efi_dev_path *node,
 			break;
 		if (!adev->pnp.unique_id && node->acpi.uid == 0)
 			break;
-		acpi_dev_put(adev);
 	}
 	if (!adev)
 		return -ENODEV;

drivers/media/pci/intel/ipu3/cio2-bridge.c

@@ -173,10 +173,8 @@ static int cio2_bridge_connect_sensor(const struct cio2_sensor_config *cfg,
 	int ret;
 
 	for_each_acpi_dev_match(adev, cfg->hid, NULL, -1) {
-		if (!adev->status.enabled) {
-			acpi_dev_put(adev);
+		if (!adev->status.enabled)
 			continue;
-		}
 
 		if (bridge->n_sensors >= CIO2_NUM_PORTS) {
 			acpi_dev_put(adev);
@@ -185,7 +183,6 @@ static int cio2_bridge_connect_sensor(const struct cio2_sensor_config *cfg,
 		}
 
 		sensor = &bridge->sensors[bridge->n_sensors];
-		sensor->adev = adev;
 		strscpy(sensor->name, cfg->hid, sizeof(sensor->name));
 
 		ret = cio2_bridge_read_acpi_buffer(adev, "SSDB",
@@ -215,6 +212,7 @@ static int cio2_bridge_connect_sensor(const struct cio2_sensor_config *cfg,
 			goto err_free_swnodes;
 		}
 
+		sensor->adev = acpi_dev_get(adev);
 		adev->fwnode.secondary = fwnode;
 
 		dev_info(&cio2->dev, "Found supported sensor %s\n",

include/acpi/acpi_bus.h

@@ -707,11 +707,6 @@ acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv);
  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
  *
  * The caller is responsible for invoking acpi_dev_put() on the returned device.
- *
- * FIXME: Due to above requirement there is a window that may invalidate @adev
- * and next iteration will use a dangling pointer, e.g. in the case of a
- * hotplug event. That said, the caller should ensure that this will never
- * happen.
  */
 #define for_each_acpi_dev_match(adev, hid, uid, hrv)			\
 	for (adev = acpi_dev_get_first_match_dev(hid, uid, hrv);	\