1 /****************************************************************************** 2 * 3 * Module Name: exstorob - AML object store support, store to object 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2017, Intel Corp. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer, 16 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include <acpi/acpi.h> 45 #include "accommon.h" 46 #include "acinterp.h" 47 48 #define _COMPONENT ACPI_EXECUTER 49 ACPI_MODULE_NAME("exstorob") 50 51 /******************************************************************************* 52 * 53 * FUNCTION: acpi_ex_store_buffer_to_buffer 54 * 55 * PARAMETERS: source_desc - Source object to copy 56 * target_desc - Destination object of the copy 57 * 58 * RETURN: Status 59 * 60 * DESCRIPTION: Copy a buffer object to another buffer object. 61 * 62 ******************************************************************************/ 63 acpi_status 64 acpi_ex_store_buffer_to_buffer(union acpi_operand_object *source_desc, 65 union acpi_operand_object *target_desc) 66 { 67 u32 length; 68 u8 *buffer; 69 70 ACPI_FUNCTION_TRACE_PTR(ex_store_buffer_to_buffer, source_desc); 71 72 /* If Source and Target are the same, just return */ 73 74 if (source_desc == target_desc) { 75 return_ACPI_STATUS(AE_OK); 76 } 77 78 /* We know that source_desc is a buffer by now */ 79 80 buffer = ACPI_CAST_PTR(u8, source_desc->buffer.pointer); 81 length = source_desc->buffer.length; 82 83 /* 84 * If target is a buffer of length zero or is a static buffer, 85 * allocate a new buffer of the proper length 86 */ 87 if ((target_desc->buffer.length == 0) || 88 (target_desc->common.flags & AOPOBJ_STATIC_POINTER)) { 89 target_desc->buffer.pointer = ACPI_ALLOCATE(length); 90 if (!target_desc->buffer.pointer) { 91 return_ACPI_STATUS(AE_NO_MEMORY); 92 } 93 94 target_desc->buffer.length = length; 95 } 96 97 /* Copy source buffer to target buffer */ 98 99 if (length <= target_desc->buffer.length) { 100 101 /* Clear existing buffer and copy in the new one */ 102 103 memset(target_desc->buffer.pointer, 0, 104 target_desc->buffer.length); 105 memcpy(target_desc->buffer.pointer, buffer, length); 106 107 #ifdef ACPI_OBSOLETE_BEHAVIOR 108 /* 109 * NOTE: ACPI versions up to 3.0 specified that the buffer must be 110 * truncated if the string is smaller than the buffer. However, "other" 111 * implementations of ACPI never did this and thus became the defacto 112 * standard. ACPI 3.0A changes this behavior such that the buffer 113 * is no longer truncated. 114 */ 115 116 /* 117 * OBSOLETE BEHAVIOR: 118 * If the original source was a string, we must truncate the buffer, 119 * according to the ACPI spec. Integer-to-Buffer and Buffer-to-Buffer 120 * copy must not truncate the original buffer. 121 */ 122 if (original_src_type == ACPI_TYPE_STRING) { 123 124 /* Set the new length of the target */ 125 126 target_desc->buffer.length = length; 127 } 128 #endif 129 } else { 130 /* Truncate the source, copy only what will fit */ 131 132 memcpy(target_desc->buffer.pointer, buffer, 133 target_desc->buffer.length); 134 135 ACPI_DEBUG_PRINT((ACPI_DB_INFO, 136 "Truncating source buffer from %X to %X\n", 137 length, target_desc->buffer.length)); 138 } 139 140 /* Copy flags */ 141 142 target_desc->buffer.flags = source_desc->buffer.flags; 143 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER; 144 return_ACPI_STATUS(AE_OK); 145 } 146 147 /******************************************************************************* 148 * 149 * FUNCTION: acpi_ex_store_string_to_string 150 * 151 * PARAMETERS: source_desc - Source object to copy 152 * target_desc - Destination object of the copy 153 * 154 * RETURN: Status 155 * 156 * DESCRIPTION: Copy a String object to another String object 157 * 158 ******************************************************************************/ 159 160 acpi_status 161 acpi_ex_store_string_to_string(union acpi_operand_object *source_desc, 162 union acpi_operand_object *target_desc) 163 { 164 u32 length; 165 u8 *buffer; 166 167 ACPI_FUNCTION_TRACE_PTR(ex_store_string_to_string, source_desc); 168 169 /* If Source and Target are the same, just return */ 170 171 if (source_desc == target_desc) { 172 return_ACPI_STATUS(AE_OK); 173 } 174 175 /* We know that source_desc is a string by now */ 176 177 buffer = ACPI_CAST_PTR(u8, source_desc->string.pointer); 178 length = source_desc->string.length; 179 180 /* 181 * Replace existing string value if it will fit and the string 182 * pointer is not a static pointer (part of an ACPI table) 183 */ 184 if ((length < target_desc->string.length) && 185 (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) { 186 /* 187 * String will fit in existing non-static buffer. 188 * Clear old string and copy in the new one 189 */ 190 memset(target_desc->string.pointer, 0, 191 (acpi_size)target_desc->string.length + 1); 192 memcpy(target_desc->string.pointer, buffer, length); 193 } else { 194 /* 195 * Free the current buffer, then allocate a new buffer 196 * large enough to hold the value 197 */ 198 if (target_desc->string.pointer && 199 (!(target_desc->common.flags & AOPOBJ_STATIC_POINTER))) { 200 201 /* Only free if not a pointer into the DSDT */ 202 203 ACPI_FREE(target_desc->string.pointer); 204 } 205 206 target_desc->string.pointer = 207 ACPI_ALLOCATE_ZEROED((acpi_size)length + 1); 208 209 if (!target_desc->string.pointer) { 210 return_ACPI_STATUS(AE_NO_MEMORY); 211 } 212 213 target_desc->common.flags &= ~AOPOBJ_STATIC_POINTER; 214 memcpy(target_desc->string.pointer, buffer, length); 215 } 216 217 /* Set the new target length */ 218 219 target_desc->string.length = length; 220 return_ACPI_STATUS(AE_OK); 221 } 222