1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /****************************************************************************** 3 * 4 * Module Name: exstorob - AML object store support, store to object 5 * 6 * Copyright (C) 2000 - 2020, Intel Corp. 7 * 8 *****************************************************************************/ 9 10 #include <acpi/acpi.h> 11 #include "accommon.h" 12 #include "acinterp.h" 13 14 #define _COMPONENT ACPI_EXECUTER 15 ACPI_MODULE_NAME("exstorob") 16 17 /******************************************************************************* 18 * 19 * FUNCTION: acpi_ex_store_buffer_to_buffer 20 * 21 * PARAMETERS: source_desc - Source object to copy 22 * target_desc - Destination object of the copy 23 * 24 * RETURN: Status 25 * 26 * DESCRIPTION: Copy a buffer object to another buffer object. 27 * 28 ******************************************************************************/ 29 acpi_status 30 acpi_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 length 52 */ 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_BEHAVIOR 74 /* 75 * NOTE: ACPI versions up to 3.0 specified that the buffer must be 76 * truncated if the string is smaller than the buffer. However, "other" 77 * implementations of ACPI never did this and thus became the defacto 78 * standard. ACPI 3.0A changes this behavior such that the buffer 79 * 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-Buffer 86 * 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 #endif 95 } 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_string 116 * 117 * PARAMETERS: source_desc - Source object to copy 118 * target_desc - Destination object of the copy 119 * 120 * RETURN: Status 121 * 122 * DESCRIPTION: Copy a String object to another String object 123 * 124 ******************************************************************************/ 125 126 acpi_status 127 acpi_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 string 148 * 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 one 155 */ 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 buffer 162 * large enough to hold the value 163 */ 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