linux/drivers/acpi/acpica/utcopy.c

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
 *
 * Module Name: utcopy - Internal to external object translation utilities
 *
 * Copyright (C) 2000 - 2021, Intel Corp.
 *
 *****************************************************************************/

#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"


#define _COMPONENT          ACPI_UTILITIES
ACPI_MODULE_NAME("utcopy")

/* Local prototypes */
static acpi_status
acpi_ut_copy_isimple_to_esimple(union acpi_operand_object *internal_object,
				union acpi_object *external_object,
				u8 *data_space, acpi_size *buffer_space_used);

static acpi_status
acpi_ut_copy_ielement_to_ielement(u8 object_type,
				  union acpi_operand_object *source_object,
				  union acpi_generic_state *state,
				  void *context);

static acpi_status
acpi_ut_copy_ipackage_to_epackage(union acpi_operand_object *internal_object,
				  u8 *buffer, acpi_size *space_used);

static acpi_status
acpi_ut_copy_esimple_to_isimple(union acpi_object *user_obj,
				union acpi_operand_object **return_obj);

static acpi_status
acpi_ut_copy_epackage_to_ipackage(union acpi_object *external_object,
				  union acpi_operand_object **internal_object);

static acpi_status
acpi_ut_copy_simple_object(union acpi_operand_object *source_desc,
			   union acpi_operand_object *dest_desc);

static acpi_status
acpi_ut_copy_ielement_to_eelement(u8 object_type,
				  union acpi_operand_object *source_object,
				  union acpi_generic_state *state,
				  void *context);

static acpi_status
acpi_ut_copy_ipackage_to_ipackage(union acpi_operand_object *source_obj,
				  union acpi_operand_object *dest_obj,
				  struct acpi_walk_state *walk_state);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_isimple_to_esimple
 *
 * PARAMETERS:  internal_object     - Source object to be copied
 *              external_object     - Where to return the copied object
 *              data_space          - Where object data is returned (such as
 *                                    buffer and string data)
 *              buffer_space_used   - Length of data_space that was used
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to copy a simple internal object to
 *              an external object.
 *
 *              The data_space buffer is assumed to have sufficient space for
 *              the object.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_isimple_to_esimple(union acpi_operand_object *internal_object,
				union acpi_object *external_object,
				u8 *data_space, acpi_size *buffer_space_used)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(ut_copy_isimple_to_esimple);

	*buffer_space_used = 0;

	/*
	 * Check for NULL object case (could be an uninitialized
	 * package element)
	 */
	if (!internal_object) {
		return_ACPI_STATUS(AE_OK);
	}

	/* Always clear the external object */

	memset(external_object, 0, sizeof(union acpi_object));

	/*
	 * In general, the external object will be the same type as
	 * the internal object
	 */
	external_object->type = internal_object->common.type;

	/* However, only a limited number of external types are supported */

	switch (internal_object->common.type) {
	case ACPI_TYPE_STRING:

		external_object->string.pointer = (char *)data_space;
		external_object->string.length = internal_object->string.length;
		*buffer_space_used = ACPI_ROUND_UP_TO_NATIVE_WORD((acpi_size)
								  internal_object->
								  string.
								  length + 1);

		memcpy((void *)data_space,
		       (void *)internal_object->string.pointer,
		       (acpi_size)internal_object->string.length + 1);
		break;

	case ACPI_TYPE_BUFFER:

		external_object->buffer.pointer = data_space;
		external_object->buffer.length = internal_object->buffer.length;
		*buffer_space_used =
		    ACPI_ROUND_UP_TO_NATIVE_WORD(internal_object->string.
						 length);

		memcpy((void *)data_space,
		       (void *)internal_object->buffer.pointer,
		       internal_object->buffer.length);
		break;

	case ACPI_TYPE_INTEGER:

		external_object->integer.value = internal_object->integer.value;
		break;

	case ACPI_TYPE_LOCAL_REFERENCE:

		/* This is an object reference. */

		switch (internal_object->reference.class) {
		case ACPI_REFCLASS_NAME:
			/*
			 * For namepath, return the object handle ("reference")
			 * We are referring to the namespace node
			 */
			external_object->reference.handle =
			    internal_object->reference.node;
			external_object->reference.actual_type =
			    acpi_ns_get_type(internal_object->reference.node);
			break;

		default:

			/* All other reference types are unsupported */

			return_ACPI_STATUS(AE_TYPE);
		}
		break;

	case ACPI_TYPE_PROCESSOR:

		external_object->processor.proc_id =
		    internal_object->processor.proc_id;
		external_object->processor.pblk_address =
		    internal_object->processor.address;
		external_object->processor.pblk_length =
		    internal_object->processor.length;
		break;

	case ACPI_TYPE_POWER:

		external_object->power_resource.system_level =
		    internal_object->power_resource.system_level;

		external_object->power_resource.resource_order =
		    internal_object->power_resource.resource_order;
		break;

	default:
		/*
		 * There is no corresponding external object type
		 */
		ACPI_ERROR((AE_INFO,
			    "Unsupported object type, cannot convert to external object: %s",
			    acpi_ut_get_type_name(internal_object->common.
						  type)));

		return_ACPI_STATUS(AE_SUPPORT);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_ielement_to_eelement
 *
 * PARAMETERS:  acpi_pkg_callback
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy one package element to another package element
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_ielement_to_eelement(u8 object_type,
				  union acpi_operand_object *source_object,
				  union acpi_generic_state *state,
				  void *context)
{
	acpi_status status = AE_OK;
	struct acpi_pkg_info *info = (struct acpi_pkg_info *)context;
	acpi_size object_space;
	u32 this_index;
	union acpi_object *target_object;

	ACPI_FUNCTION_ENTRY();

	this_index = state->pkg.index;
	target_object = (union acpi_object *)&((union acpi_object *)
					       (state->pkg.dest_object))->
	    package.elements[this_index];

	switch (object_type) {
	case ACPI_COPY_TYPE_SIMPLE:
		/*
		 * This is a simple or null object
		 */
		status = acpi_ut_copy_isimple_to_esimple(source_object,
							 target_object,
							 info->free_space,
							 &object_space);
		if (ACPI_FAILURE(status)) {
			return (status);
		}
		break;

	case ACPI_COPY_TYPE_PACKAGE:
		/*
		 * Build the package object
		 */
		target_object->type = ACPI_TYPE_PACKAGE;
		target_object->package.count = source_object->package.count;
		target_object->package.elements =
		    ACPI_CAST_PTR(union acpi_object, info->free_space);

		/*
		 * Pass the new package object back to the package walk routine
		 */
		state->pkg.this_target_obj = target_object;

		/*
		 * Save space for the array of objects (Package elements)
		 * update the buffer length counter
		 */
		object_space = ACPI_ROUND_UP_TO_NATIVE_WORD((acpi_size)
							    target_object->
							    package.count *
							    sizeof(union
								   acpi_object));
		break;

	default:

		return (AE_BAD_PARAMETER);
	}

	info->free_space += object_space;
	info->length += object_space;
	return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_ipackage_to_epackage
 *
 * PARAMETERS:  internal_object     - Pointer to the object we are returning
 *              buffer              - Where the object is returned
 *              space_used          - Where the object length is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to place a package object in a user
 *              buffer. A package object by definition contains other objects.
 *
 *              The buffer is assumed to have sufficient space for the object.
 *              The caller must have verified the buffer length needed using
 *              the acpi_ut_get_object_size function before calling this function.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_ipackage_to_epackage(union acpi_operand_object *internal_object,
				  u8 *buffer, acpi_size *space_used)
{
	union acpi_object *external_object;
	acpi_status status;
	struct acpi_pkg_info info;

	ACPI_FUNCTION_TRACE(ut_copy_ipackage_to_epackage);

	/*
	 * First package at head of the buffer
	 */
	external_object = ACPI_CAST_PTR(union acpi_object, buffer);

	/*
	 * Free space begins right after the first package
	 */
	info.length = ACPI_ROUND_UP_TO_NATIVE_WORD(sizeof(union acpi_object));
	info.free_space = buffer +
	    ACPI_ROUND_UP_TO_NATIVE_WORD(sizeof(union acpi_object));
	info.object_space = 0;
	info.num_packages = 1;

	external_object->type = internal_object->common.type;
	external_object->package.count = internal_object->package.count;
	external_object->package.elements =
	    ACPI_CAST_PTR(union acpi_object, info.free_space);

	/*
	 * Leave room for an array of ACPI_OBJECTS in the buffer
	 * and move the free space past it
	 */
	info.length += (acpi_size)external_object->package.count *
	    ACPI_ROUND_UP_TO_NATIVE_WORD(sizeof(union acpi_object));
	info.free_space += external_object->package.count *
	    ACPI_ROUND_UP_TO_NATIVE_WORD(sizeof(union acpi_object));

	status = acpi_ut_walk_package_tree(internal_object, external_object,
					   acpi_ut_copy_ielement_to_eelement,
					   &info);

	*space_used = info.length;
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_iobject_to_eobject
 *
 * PARAMETERS:  internal_object     - The internal object to be converted
 *              ret_buffer          - Where the object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to build an API object to be returned
 *              to the caller.
 *
 ******************************************************************************/

acpi_status
acpi_ut_copy_iobject_to_eobject(union acpi_operand_object *internal_object,
				struct acpi_buffer *ret_buffer)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ut_copy_iobject_to_eobject);

	if (internal_object->common.type == ACPI_TYPE_PACKAGE) {
		/*
		 * Package object:  Copy all subobjects (including
		 * nested packages)
		 */
		status = acpi_ut_copy_ipackage_to_epackage(internal_object,
							   ret_buffer->pointer,
							   &ret_buffer->length);
	} else {
		/*
		 * Build a simple object (no nested objects)
		 */
		status = acpi_ut_copy_isimple_to_esimple(internal_object,
							 ACPI_CAST_PTR(union
								       acpi_object,
								       ret_buffer->
								       pointer),
							 ACPI_ADD_PTR(u8,
								      ret_buffer->
								      pointer,
								      ACPI_ROUND_UP_TO_NATIVE_WORD
								      (sizeof
								       (union
									acpi_object))),
							 &ret_buffer->length);
		/*
		 * build simple does not include the object size in the length
		 * so we add it in here
		 */
		ret_buffer->length += sizeof(union acpi_object);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_esimple_to_isimple
 *
 * PARAMETERS:  external_object     - The external object to be converted
 *              ret_internal_object - Where the internal object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function copies an external object to an internal one.
 *              NOTE: Pointers can be copied, we don't need to copy data.
 *              (The pointers have to be valid in our address space no matter
 *              what we do with them!)
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_esimple_to_isimple(union acpi_object *external_object,
				union acpi_operand_object **ret_internal_object)
{
	union acpi_operand_object *internal_object;

	ACPI_FUNCTION_TRACE(ut_copy_esimple_to_isimple);

	/*
	 * Simple types supported are: String, Buffer, Integer
	 */
	switch (external_object->type) {
	case ACPI_TYPE_STRING:
	case ACPI_TYPE_BUFFER:
	case ACPI_TYPE_INTEGER:
	case ACPI_TYPE_LOCAL_REFERENCE:

		internal_object = acpi_ut_create_internal_object((u8)
								 external_object->
								 type);
		if (!internal_object) {
			return_ACPI_STATUS(AE_NO_MEMORY);
		}
		break;

	case ACPI_TYPE_ANY:	/* This is the case for a NULL object */

		*ret_internal_object = NULL;
		return_ACPI_STATUS(AE_OK);

	default:

		/* All other types are not supported */

		ACPI_ERROR((AE_INFO,
			    "Unsupported object type, cannot convert to internal object: %s",
			    acpi_ut_get_type_name(external_object->type)));

		return_ACPI_STATUS(AE_SUPPORT);
	}

	/* Must COPY string and buffer contents */

	switch (external_object->type) {
	case ACPI_TYPE_STRING:

		internal_object->string.pointer =
		    ACPI_ALLOCATE_ZEROED((acpi_size)
					 external_object->string.length + 1);

		if (!internal_object->string.pointer) {
			goto error_exit;
		}

		memcpy(internal_object->string.pointer,
		       external_object->string.pointer,
		       external_object->string.length);

		internal_object->string.length = external_object->string.length;
		break;

	case ACPI_TYPE_BUFFER:

		internal_object->buffer.pointer =
		    ACPI_ALLOCATE_ZEROED(external_object->buffer.length);
		if (!internal_object->buffer.pointer) {
			goto error_exit;
		}

		memcpy(internal_object->buffer.pointer,
		       external_object->buffer.pointer,
		       external_object->buffer.length);

		internal_object->buffer.length = external_object->buffer.length;

		/* Mark buffer data valid */

		internal_object->buffer.flags |= AOPOBJ_DATA_VALID;
		break;

	case ACPI_TYPE_INTEGER:

		internal_object->integer.value = external_object->integer.value;
		break;

	case ACPI_TYPE_LOCAL_REFERENCE:

		/* An incoming reference is defined to be a namespace node */

		internal_object->reference.class = ACPI_REFCLASS_REFOF;
		internal_object->reference.object =
		    external_object->reference.handle;
		break;

	default:

		/* Other types can't get here */

		break;
	}

	*ret_internal_object = internal_object;
	return_ACPI_STATUS(AE_OK);

error_exit:
	acpi_ut_remove_reference(internal_object);
	return_ACPI_STATUS(AE_NO_MEMORY);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_epackage_to_ipackage
 *
 * PARAMETERS:  external_object     - The external object to be converted
 *              internal_object     - Where the internal object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy an external package object to an internal package.
 *              Handles nested packages.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_epackage_to_ipackage(union acpi_object *external_object,
				  union acpi_operand_object **internal_object)
{
	acpi_status status = AE_OK;
	union acpi_operand_object *package_object;
	union acpi_operand_object **package_elements;
	u32 i;

	ACPI_FUNCTION_TRACE(ut_copy_epackage_to_ipackage);

	/* Create the package object */

	package_object =
	    acpi_ut_create_package_object(external_object->package.count);
	if (!package_object) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	package_elements = package_object->package.elements;

	/*
	 * Recursive implementation. Probably ok, since nested external
	 * packages as parameters should be very rare.
	 */
	for (i = 0; i < external_object->package.count; i++) {
		status =
		    acpi_ut_copy_eobject_to_iobject(&external_object->package.
						    elements[i],
						    &package_elements[i]);
		if (ACPI_FAILURE(status)) {

			/* Truncate package and delete it */

			package_object->package.count = i;
			package_elements[i] = NULL;
			acpi_ut_remove_reference(package_object);
			return_ACPI_STATUS(status);
		}
	}

	/* Mark package data valid */

	package_object->package.flags |= AOPOBJ_DATA_VALID;

	*internal_object = package_object;
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_eobject_to_iobject
 *
 * PARAMETERS:  external_object     - The external object to be converted
 *              internal_object     - Where the internal object is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Converts an external object to an internal object.
 *
 ******************************************************************************/

acpi_status
acpi_ut_copy_eobject_to_iobject(union acpi_object *external_object,
				union acpi_operand_object **internal_object)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ut_copy_eobject_to_iobject);

	if (external_object->type == ACPI_TYPE_PACKAGE) {
		status =
		    acpi_ut_copy_epackage_to_ipackage(external_object,
						      internal_object);
	} else {
		/*
		 * Build a simple object (no nested objects)
		 */
		status = acpi_ut_copy_esimple_to_isimple(external_object,
							 internal_object);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_simple_object
 *
 * PARAMETERS:  source_desc         - The internal object to be copied
 *              dest_desc           - New target object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Simple copy of one internal object to another. Reference count
 *              of the destination object is preserved.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_simple_object(union acpi_operand_object *source_desc,
			   union acpi_operand_object *dest_desc)
{
	u16 reference_count;
	union acpi_operand_object *next_object;
	acpi_status status;
	acpi_size copy_size;

	/* Save fields from destination that we don't want to overwrite */

	reference_count = dest_desc->common.reference_count;
	next_object = dest_desc->common.next_object;

	/*
	 * Copy the entire source object over the destination object.
	 * Note: Source can be either an operand object or namespace node.
	 */
	copy_size = sizeof(union acpi_operand_object);
	if (ACPI_GET_DESCRIPTOR_TYPE(source_desc) == ACPI_DESC_TYPE_NAMED) {
		copy_size = sizeof(struct acpi_namespace_node);
	}

	memcpy(ACPI_CAST_PTR(char, dest_desc),
	       ACPI_CAST_PTR(char, source_desc), copy_size);

	/* Restore the saved fields */

	dest_desc->common.reference_count = reference_count;
	dest_desc->common.next_object = next_object;

	/* New object is not static, regardless of source */

	dest_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;

	/* Handle the objects with extra data */

	switch (dest_desc->common.type) {
	case ACPI_TYPE_BUFFER:
		/*
		 * Allocate and copy the actual buffer if and only if:
		 * 1) There is a valid buffer pointer
		 * 2) The buffer has a length > 0
		 */
		if ((source_desc->buffer.pointer) &&
		    (source_desc->buffer.length)) {
			dest_desc->buffer.pointer =
			    ACPI_ALLOCATE(source_desc->buffer.length);
			if (!dest_desc->buffer.pointer) {
				return (AE_NO_MEMORY);
			}

			/* Copy the actual buffer data */

			memcpy(dest_desc->buffer.pointer,
			       source_desc->buffer.pointer,
			       source_desc->buffer.length);
		}
		break;

	case ACPI_TYPE_STRING:
		/*
		 * Allocate and copy the actual string if and only if:
		 * 1) There is a valid string pointer
		 * (Pointer to a NULL string is allowed)
		 */
		if (source_desc->string.pointer) {
			dest_desc->string.pointer =
			    ACPI_ALLOCATE((acpi_size)source_desc->string.
					  length + 1);
			if (!dest_desc->string.pointer) {
				return (AE_NO_MEMORY);
			}

			/* Copy the actual string data */

			memcpy(dest_desc->string.pointer,
			       source_desc->string.pointer,
			       (acpi_size)source_desc->string.length + 1);
		}
		break;

	case ACPI_TYPE_LOCAL_REFERENCE:
		/*
		 * We copied the reference object, so we now must add a reference
		 * to the object pointed to by the reference
		 *
		 * DDBHandle reference (from Load/load_table) is a special reference,
		 * it does not have a Reference.Object, so does not need to
		 * increase the reference count
		 */
		if (source_desc->reference.class == ACPI_REFCLASS_TABLE) {
			break;
		}

		acpi_ut_add_reference(source_desc->reference.object);
		break;

	case ACPI_TYPE_REGION:
		/*
		 * We copied the Region Handler, so we now must add a reference
		 */
		if (dest_desc->region.handler) {
			acpi_ut_add_reference(dest_desc->region.handler);
		}
		break;

		/*
		 * For Mutex and Event objects, we cannot simply copy the underlying
		 * OS object. We must create a new one.
		 */
	case ACPI_TYPE_MUTEX:

		status = acpi_os_create_mutex(&dest_desc->mutex.os_mutex);
		if (ACPI_FAILURE(status)) {
			return (status);
		}
		break;

	case ACPI_TYPE_EVENT:

		status = acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0,
						  &dest_desc->event.
						  os_semaphore);
		if (ACPI_FAILURE(status)) {
			return (status);
		}
		break;

	default:

		/* Nothing to do for other simple objects */

		break;
	}

	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_ielement_to_ielement
 *
 * PARAMETERS:  acpi_pkg_callback
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy one package element to another package element
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_ielement_to_ielement(u8 object_type,
				  union acpi_operand_object *source_object,
				  union acpi_generic_state *state,
				  void *context)
{
	acpi_status status = AE_OK;
	u32 this_index;
	union acpi_operand_object **this_target_ptr;
	union acpi_operand_object *target_object;

	ACPI_FUNCTION_ENTRY();

	this_index = state->pkg.index;
	this_target_ptr = (union acpi_operand_object **)
	    &state->pkg.dest_object->package.elements[this_index];

	switch (object_type) {
	case ACPI_COPY_TYPE_SIMPLE:

		/* A null source object indicates a (legal) null package element */

		if (source_object) {
			/*
			 * This is a simple object, just copy it
			 */
			target_object =
			    acpi_ut_create_internal_object(source_object->
							   common.type);
			if (!target_object) {
				return (AE_NO_MEMORY);
			}

			status =
			    acpi_ut_copy_simple_object(source_object,
						       target_object);
			if (ACPI_FAILURE(status)) {
				goto error_exit;
			}

			*this_target_ptr = target_object;
		} else {
			/* Pass through a null element */

			*this_target_ptr = NULL;
		}
		break;

	case ACPI_COPY_TYPE_PACKAGE:
		/*
		 * This object is a package - go down another nesting level
		 * Create and build the package object
		 */
		target_object =
		    acpi_ut_create_package_object(source_object->package.count);
		if (!target_object) {
			return (AE_NO_MEMORY);
		}

		target_object->common.flags = source_object->common.flags;

		/* Pass the new package object back to the package walk routine */

		state->pkg.this_target_obj = target_object;

		/* Store the object pointer in the parent package object */

		*this_target_ptr = target_object;
		break;

	default:

		return (AE_BAD_PARAMETER);
	}

	return (status);

error_exit:
	acpi_ut_remove_reference(target_object);
	return (status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_ipackage_to_ipackage
 *
 * PARAMETERS:  source_obj      - Pointer to the source package object
 *              dest_obj        - Where the internal object is returned
 *              walk_state      - Current Walk state descriptor
 *
 * RETURN:      Status
 *
 * DESCRIPTION: This function is called to copy an internal package object
 *              into another internal package object.
 *
 ******************************************************************************/

static acpi_status
acpi_ut_copy_ipackage_to_ipackage(union acpi_operand_object *source_obj,
				  union acpi_operand_object *dest_obj,
				  struct acpi_walk_state *walk_state)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(ut_copy_ipackage_to_ipackage);

	dest_obj->common.type = source_obj->common.type;
	dest_obj->common.flags = source_obj->common.flags;
	dest_obj->package.count = source_obj->package.count;

	/*
	 * Create the object array and walk the source package tree
	 */
	dest_obj->package.elements = ACPI_ALLOCATE_ZEROED(((acpi_size)
							   source_obj->package.
							   count +
							   1) * sizeof(void *));
	if (!dest_obj->package.elements) {
		ACPI_ERROR((AE_INFO, "Package allocation failure"));
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/*
	 * Copy the package element-by-element by walking the package "tree".
	 * This handles nested packages of arbitrary depth.
	 */
	status = acpi_ut_walk_package_tree(source_obj, dest_obj,
					   acpi_ut_copy_ielement_to_ielement,
					   walk_state);
	if (ACPI_FAILURE(status)) {

		/* On failure, delete the destination package object */

		acpi_ut_remove_reference(dest_obj);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_copy_iobject_to_iobject
 *
 * PARAMETERS:  source_desc         - The internal object to be copied
 *              dest_desc           - Where the copied object is returned
 *              walk_state          - Current walk state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Copy an internal object to a new internal object
 *
 ******************************************************************************/

acpi_status
acpi_ut_copy_iobject_to_iobject(union acpi_operand_object *source_desc,
				union acpi_operand_object **dest_desc,
				struct acpi_walk_state *walk_state)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(ut_copy_iobject_to_iobject);

	/* Create the top level object */

	*dest_desc = acpi_ut_create_internal_object(source_desc->common.type);
	if (!*dest_desc) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/* Copy the object and possible subobjects */

	if (source_desc->common.type == ACPI_TYPE_PACKAGE) {
		status =
		    acpi_ut_copy_ipackage_to_ipackage(source_desc, *dest_desc,
						      walk_state);
	} else {
		status = acpi_ut_copy_simple_object(source_desc, *dest_desc);
	}

	/* Delete the allocated object if copy failed */

	if (ACPI_FAILURE(status)) {
		acpi_ut_remove_reference(*dest_desc);
	}

	return_ACPI_STATUS(status);
}