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1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.02/******************************************************************************3 *4 * Module Name: exstorob - AML object store support, store to object5 *6 * Copyright (C) 2000 - 2023, Intel Corp.7 *8 *****************************************************************************/9 10#include <acpi/acpi.h>11#include "accommon.h"12#include "acinterp.h"13 14#define _COMPONENT ACPI_EXECUTER15ACPI_MODULE_NAME("exstorob")16 17/*******************************************************************************18 *19 * FUNCTION: acpi_ex_store_buffer_to_buffer20 *21 * PARAMETERS: source_desc - Source object to copy22 * target_desc - Destination object of the copy23 *24 * RETURN: Status25 *26 * DESCRIPTION: Copy a buffer object to another buffer object.27 *28 ******************************************************************************/29acpi_status30acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc,31 union acpi_operand_object *target_desc)32{33 u32 length;34 u8 *buffer;35 36 ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc);37 38 /* If Source and Target are the same, just return */39 40 if (source_desc == target_desc) {41 return_ACPI_STATUS(AE_OK);42 }43 44 /* We know that source_desc is a buffer by now */45 46 buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer);47 length = source_desc->buffer.length;48 49 /*50 * If target is a buffer of length zero or is a static buffer,51 * allocate a new buffer of the proper length52 */53 if ((target_desc->buffer.length == 0) ||54 (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) {55 target_desc->buffer.pointer = ACPI_ALLOCATE(length);56 if (!target_desc->buffer.pointer) {57 return_ACPI_STATUS(AE_NO_MEMORY);58 }59 60 target_desc->buffer.length = length;61 }62 63 /* Copy source buffer to target buffer */64 65 if (length <= target_desc->buffer.length) {66 67 /* Clear existing buffer and copy in the new one */68 69 memset(target_desc->buffer.pointer, 0,70 target_desc->buffer.length);71 memcpy(target_desc->buffer.pointer, buffer, length);72 73#ifdef ACPI_OBSOLETE_BEHAVIOR74 /*75 * NOTE: ACPI versions up to 3.0 specified that the buffer must be76 * truncated if the string is smaller than the buffer. However, "other"77 * implementations of ACPI never did this and thus became the defacto78 * standard. ACPI 3.0A changes this behavior such that the buffer79 * is no longer truncated.80 */81 82 /*83 * OBSOLETE BEHAVIOR:84 * If the original source was a string, we must truncate the buffer,85 * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer86 * copy must not truncate the original buffer.87 */88 if (original_src_type == ACPI_TYPE_STRING) {89 90 /* Set the new length of the target */91 92 target_desc->buffer.length = length;93 }94#endif95 } else {96 /* Truncate the source, copy only what will fit */97 98 memcpy(target_desc->buffer.pointer, buffer,99 target_desc->buffer.length);100 101 ACPI_DEBUG_PRINT((ACPI_DB_INFO,102 "Truncating source buffer from %X to %X\n",103 length, target_desc->buffer.length));104 }105 106 /* Copy flags */107 108 target_desc->buffer.flags = source_desc->buffer.flags;109 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;110 return_ACPI_STATUS(AE_OK);111}112 113/*******************************************************************************114 *115 * FUNCTION: acpi_ex_store_string_to_string116 *117 * PARAMETERS: source_desc - Source object to copy118 * target_desc - Destination object of the copy119 *120 * RETURN: Status121 *122 * DESCRIPTION: Copy a String object to another String object123 *124 ******************************************************************************/125 126acpi_status127acpi_ex_store_string_to_string(union acpi_operand_object *source_desc,128 union acpi_operand_object *target_desc)129{130 u32 length;131 u8 *buffer;132 133 ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc);134 135 /* If Source and Target are the same, just return */136 137 if (source_desc == target_desc) {138 return_ACPI_STATUS(AE_OK);139 }140 141 /* We know that source_desc is a string by now */142 143 buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer);144 length = source_desc->string.length;145 146 /*147 * Replace existing string value if it will fit and the string148 * pointer is not a static pointer (part of an ACPI table)149 */150 if ((length < target_desc->string.length) &&151 (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {152 /*153 * String will fit in existing non-static buffer.154 * Clear old string and copy in the new one155 */156 memset(target_desc->string.pointer, 0,157 (acpi_size)target_desc->string.length + 1);158 memcpy(target_desc->string.pointer, buffer, length);159 } else {160 /*161 * Free the current buffer, then allocate a new buffer162 * large enough to hold the value163 */164 if (target_desc->string.pointer &&165 (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) {166 167 /* Only free if not a pointer into the DSDT */168 169 ACPI_FREE(target_desc->string.pointer);170 }171 172 target_desc->string.pointer =173 ACPI_ALLOCATE_ZEROED((acpi_size)length + 1);174 175 if (!target_desc->string.pointer) {176 return_ACPI_STATUS(AE_NO_MEMORY);177 }178 179 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER;180 memcpy(target_desc->string.pointer, buffer, length);181 }182 183 /* Set the new target length */184 185 target_desc->string.length = length;186 return_ACPI_STATUS(AE_OK);187}188