// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: exstorob - AML object store support, store to object
*
* Copyright (C) 2000 - 2025, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acinterp.h"
#define _COMPONENT ACPI_EXECUTER
ACPI_MODULE_NAME(
"exstorob")
/*******************************************************************************
*
* FUNCTION: acpi_ex_store_buffer_to_buffer
*
* PARAMETERS: source_desc - Source object to copy
* target_desc - Destination object of the copy
*
* RETURN: Status
*
* DESCRIPTION: Copy a buffer object to another buffer object.
*
******************************************************************************/
acpi_status
acpi_ex_store_buffer_to_buffer(
union acpi_operand_object *source_desc,
union acpi_operand_object *target_desc)
{
u32 length;
u8 *buffer;
ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);
/* If Source and Target are the same, just return */
if (source_desc == target_desc) {
return_ACPI_STATUS(AE_OK);
}
/* We know that source_desc is a buffer by now */
buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);
length = source_desc->buffer.length;
/*
* If target is a buffer of length zero or is a static buffer,
* allocate a new buffer of the proper length
*/
if ((target_desc->buffer.length == 0) ||
(target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {
target_desc->buffer.pointer = ACPI_ALLOCATE(length);
if (!target_desc->buffer.pointer) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
target_desc->buffer.length = length;
}
/* Copy source buffer to target buffer */
if (length <= target_desc->buffer.length) {
/* Clear existing buffer and copy in the new one */
memset(target_desc->buffer.pointer, 0,
target_desc->buffer.length);
memcpy(target_desc->buffer.pointer, buffer, length);
#ifdef ACPI_OBSOLETE_BEHAVIOR
/*
* NOTE: ACPI versions up to 3.0 specified that the buffer must be
* truncated if the string is smaller than the buffer. However, "other"
* implementations of ACPI never did this and thus became the defacto
* standard. ACPI 3.0A changes this behavior such that the buffer
* is no longer truncated.
*/
/*
* OBSOLETE BEHAVIOR:
* If the original source was a string, we must truncate the buffer,
* according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer
* copy must not truncate the original buffer.
*/
if (original_src_type == ACPI_TYPE_STRING) {
/* Set the new length of the target */
target_desc->buffer.length = length;
}
#endif
}
else {
/* Truncate the source, copy only what will fit */
memcpy(target_desc->buffer.pointer, buffer,
target_desc->buffer.length);
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Truncating source buffer from %X to %X\n",
length, target_desc->buffer.length));
}
/* Copy flags */
target_desc->buffer.flags = source_desc->buffer.flags;
target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ex_store_string_to_string
*
* PARAMETERS: source_desc - Source object to copy
* target_desc - Destination object of the copy
*
* RETURN: Status
*
* DESCRIPTION: Copy a String object to another String object
*
******************************************************************************/
acpi_status
acpi_ex_store_string_to_string(
union acpi_operand_object *source_desc,
union acpi_operand_object *target_desc)
{
u32 length;
u8 *buffer;
ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);
/* If Source and Target are the same, just return */
if (source_desc == target_desc) {
return_ACPI_STATUS(AE_OK);
}
/* We know that source_desc is a string by now */
buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);
length = source_desc->string.length;
/*
* Replace existing string value if it will fit and the string
* pointer is not a static pointer (part of an ACPI table)
*/
if ((length < target_desc->string.length) &&
(!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
/*
* String will fit in existing non-static buffer.
* Clear old string and copy in the new one
*/
memset(target_desc->string.pointer, 0,
(acpi_size)target_desc->string.length + 1);
memcpy(target_desc->string.pointer, buffer, length);
}
else {
/*
* Free the current buffer, then allocate a new buffer
* large enough to hold the value
*/
if (target_desc->string.pointer &&
(!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {
/* Only free if not a pointer into the DSDT */
ACPI_FREE(target_desc->string.pointer);
}
target_desc->string.pointer =
ACPI_ALLOCATE_ZEROED((acpi_size)length + 1);
if (!target_desc->string.pointer) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;
memcpy(target_desc->string.pointer, buffer, length);
}
/* Set the new target length */
target_desc->string.length = length;
return_ACPI_STATUS(AE_OK);
}
