1 /******************************************************************************* 2 * 3 * Module Name: utstrtoul64 - String-to-integer conversion support for both 4 * 64-bit and 32-bit integers 5 * 6 ******************************************************************************/ 7 8 /* 9 * Copyright (C) 2000 - 2017, Intel Corp. 10 * All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions, and the following disclaimer, 17 * without modification. 18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 19 * substantially similar to the "NO WARRANTY" disclaimer below 20 * ("Disclaimer") and any redistribution must be conditioned upon 21 * including a substantially similar Disclaimer requirement for further 22 * binary redistribution. 23 * 3. Neither the names of the above-listed copyright holders nor the names 24 * of any contributors may be used to endorse or promote products derived 25 * from this software without specific prior written permission. 26 * 27 * Alternatively, this software may be distributed under the terms of the 28 * GNU General Public License ("GPL") version 2 as published by the Free 29 * Software Foundation. 30 * 31 * NO WARRANTY 32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 42 * POSSIBILITY OF SUCH DAMAGES. 43 */ 44 45 #include <acpi/acpi.h> 46 #include "accommon.h" 47 48 #define _COMPONENT ACPI_UTILITIES 49 ACPI_MODULE_NAME("utstrtoul64") 50 51 /******************************************************************************* 52 * 53 * This module contains the top-level string to 64/32-bit unsigned integer 54 * conversion functions: 55 * 56 * 1) A standard strtoul() function that supports 64-bit integers, base 57 * 8/10/16, with integer overflow support. This is used mainly by the 58 * iASL compiler, which implements tighter constraints on integer 59 * constants than the runtime (interpreter) integer-to-string conversions. 60 * 2) Runtime "Explicit conversion" as defined in the ACPI specification. 61 * 3) Runtime "Implicit conversion" as defined in the ACPI specification. 62 * 63 * Current users of this module: 64 * 65 * iASL - Preprocessor (constants and math expressions) 66 * iASL - Main parser, conversion of constants to integers 67 * iASL - Data Table Compiler parser (constants and math expressions) 68 * interpreter - Implicit and explicit conversions, GPE method names 69 * interpreter - Repair code for return values from predefined names 70 * debugger - Command line input string conversion 71 * acpi_dump - ACPI table physical addresses 72 * acpi_exec - Support for namespace overrides 73 * 74 * Notes concerning users of these interfaces: 75 * 76 * acpi_gbl_integer_byte_width is used to set the 32/64 bit limit for explicit 77 * and implicit conversions. This global must be set to the proper width. 78 * For the core ACPICA code, the width depends on the DSDT version. For the 79 * acpi_ut_strtoul64 interface, all conversions are 64 bits. This interface is 80 * used primarily for iASL, where the default width is 64 bits for all parsers, 81 * but error checking is performed later to flag cases where a 64-bit constant 82 * is wrongly defined in a 32-bit DSDT/SSDT. 83 * 84 * In ACPI, the only place where octal numbers are supported is within 85 * the ASL language itself. This is implemented via the main acpi_ut_strtoul64 86 * interface. According the ACPI specification, there is no ACPI runtime 87 * support (explicit/implicit) for octal string conversions. 88 * 89 ******************************************************************************/ 90 /******************************************************************************* 91 * 92 * FUNCTION: acpi_ut_strtoul64 93 * 94 * PARAMETERS: string - Null terminated input string, 95 * must be a valid pointer 96 * return_value - Where the converted integer is 97 * returned. Must be a valid pointer 98 * 99 * RETURN: Status and converted integer. Returns an exception on a 100 * 64-bit numeric overflow 101 * 102 * DESCRIPTION: Convert a string into an unsigned integer. Always performs a 103 * full 64-bit conversion, regardless of the current global 104 * integer width. Supports Decimal, Hex, and Octal strings. 105 * 106 * Current users of this function: 107 * 108 * iASL - Preprocessor (constants and math expressions) 109 * iASL - Main ASL parser, conversion of ASL constants to integers 110 * iASL - Data Table Compiler parser (constants and math expressions) 111 * interpreter - Repair code for return values from predefined names 112 * acpi_dump - ACPI table physical addresses 113 * acpi_exec - Support for namespace overrides 114 * 115 ******************************************************************************/ 116 acpi_status acpi_ut_strtoul64(char *string, u64 *return_value) 117 { 118 acpi_status status = AE_OK; 119 u8 original_bit_width; 120 u32 base = 10; /* Default is decimal */ 121 122 ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string); 123 124 *return_value = 0; 125 126 /* A NULL return string returns a value of zero */ 127 128 if (*string == 0) { 129 return_ACPI_STATUS(AE_OK); 130 } 131 132 if (!acpi_ut_remove_whitespace(&string)) { 133 return_ACPI_STATUS(AE_OK); 134 } 135 136 /* 137 * 1) Check for a hex constant. A "0x" prefix indicates base 16. 138 */ 139 if (acpi_ut_detect_hex_prefix(&string)) { 140 base = 16; 141 } 142 143 /* 144 * 2) Check for an octal constant, defined to be a leading zero 145 * followed by sequence of octal digits (0-7) 146 */ 147 else if (acpi_ut_detect_octal_prefix(&string)) { 148 base = 8; 149 } 150 151 if (!acpi_ut_remove_leading_zeros(&string)) { 152 return_ACPI_STATUS(AE_OK); /* Return value 0 */ 153 } 154 155 /* 156 * Force a full 64-bit conversion. The caller (usually iASL) must 157 * check for a 32-bit overflow later as necessary (If current mode 158 * is 32-bit, meaning a 32-bit DSDT). 159 */ 160 original_bit_width = acpi_gbl_integer_bit_width; 161 acpi_gbl_integer_bit_width = 64; 162 163 /* 164 * Perform the base 8, 10, or 16 conversion. A 64-bit numeric overflow 165 * will return an exception (to allow iASL to flag the statement). 166 */ 167 switch (base) { 168 case 8: 169 status = acpi_ut_convert_octal_string(string, return_value); 170 break; 171 172 case 10: 173 status = acpi_ut_convert_decimal_string(string, return_value); 174 break; 175 176 case 16: 177 default: 178 status = acpi_ut_convert_hex_string(string, return_value); 179 break; 180 } 181 182 /* Only possible exception from above is a 64-bit overflow */ 183 184 acpi_gbl_integer_bit_width = original_bit_width; 185 return_ACPI_STATUS(status); 186 } 187 188 /******************************************************************************* 189 * 190 * FUNCTION: acpi_ut_implicit_strtoul64 191 * 192 * PARAMETERS: string - Null terminated input string, 193 * must be a valid pointer 194 * 195 * RETURN: Converted integer 196 * 197 * DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon 198 * an "implicit conversion" by the ACPI specification. Used by 199 * many ASL operators that require an integer operand, and support 200 * an automatic (implicit) conversion from a string operand 201 * to the final integer operand. The major restriction is that 202 * only hex strings are supported. 203 * 204 * ----------------------------------------------------------------------------- 205 * 206 * Base is always 16, either with or without the 0x prefix. Decimal and 207 * Octal strings are not supported, as per the ACPI specification. 208 * 209 * Examples (both are hex values): 210 * Add ("BA98", Arg0, Local0) 211 * Subtract ("0x12345678", Arg1, Local1) 212 * 213 * Conversion rules as extracted from the ACPI specification: 214 * 215 * The converted integer is initialized to the value zero. 216 * The ASCII string is always interpreted as a hexadecimal constant. 217 * 218 * 1) According to the ACPI specification, a "0x" prefix is not allowed. 219 * However, ACPICA allows this as an ACPI extension on general 220 * principle. (NO ERROR) 221 * 222 * 2) The conversion terminates when the size of an integer is reached 223 * (32 or 64 bits). There are no numeric overflow conditions. (NO ERROR) 224 * 225 * 3) The first non-hex character terminates the conversion and returns 226 * the current accumulated value of the converted integer (NO ERROR). 227 * 228 * 4) Conversion of a null (zero-length) string to an integer is 229 * technically not allowed. However, ACPICA allows this as an ACPI 230 * extension. The conversion returns the value 0. (NO ERROR) 231 * 232 * NOTE: There are no error conditions returned by this function. At 233 * the minimum, a value of zero is returned. 234 * 235 * Current users of this function: 236 * 237 * interpreter - All runtime implicit conversions, as per ACPI specification 238 * iASL - Data Table Compiler parser (constants and math expressions) 239 * 240 ******************************************************************************/ 241 242 u64 acpi_ut_implicit_strtoul64(char *string) 243 { 244 u64 converted_integer = 0; 245 246 ACPI_FUNCTION_TRACE_STR(ut_implicit_strtoul64, string); 247 248 if (!acpi_ut_remove_whitespace(&string)) { 249 return_VALUE(0); 250 } 251 252 /* 253 * Per the ACPI specification, only hexadecimal is supported for 254 * implicit conversions, and the "0x" prefix is "not allowed". 255 * However, allow a "0x" prefix as an ACPI extension. 256 */ 257 acpi_ut_detect_hex_prefix(&string); 258 259 if (!acpi_ut_remove_leading_zeros(&string)) { 260 return_VALUE(0); 261 } 262 263 /* 264 * Ignore overflow as per the ACPI specification. This is implemented by 265 * ignoring the return status from the conversion function called below. 266 * On overflow, the input string is simply truncated. 267 */ 268 acpi_ut_convert_hex_string(string, &converted_integer); 269 return_VALUE(converted_integer); 270 } 271 272 /******************************************************************************* 273 * 274 * FUNCTION: acpi_ut_explicit_strtoul64 275 * 276 * PARAMETERS: string - Null terminated input string, 277 * must be a valid pointer 278 * 279 * RETURN: Converted integer 280 * 281 * DESCRIPTION: Perform a 64-bit conversion with the restrictions placed upon 282 * an "explicit conversion" by the ACPI specification. The 283 * main restriction is that only hex and decimal are supported. 284 * 285 * ----------------------------------------------------------------------------- 286 * 287 * Base is either 10 (default) or 16 (with 0x prefix). Octal (base 8) strings 288 * are not supported, as per the ACPI specification. 289 * 290 * Examples: 291 * to_integer ("1000") Decimal 292 * to_integer ("0xABCD") Hex 293 * 294 * Conversion rules as extracted from the ACPI specification: 295 * 296 * 1) The input string is either a decimal or hexadecimal numeric string. 297 * A hex value must be prefixed by "0x" or it is interpreted as decimal. 298 * 299 * 2) The value must not exceed the maximum of an integer value 300 * (32 or 64 bits). The ACPI specification states the behavior is 301 * "unpredictable", so ACPICA matches the behavior of the implicit 302 * conversion case. There are no numeric overflow conditions. (NO ERROR) 303 * 304 * 3) Behavior on the first non-hex character is not defined by the ACPI 305 * specification (for the to_integer operator), so ACPICA matches the 306 * behavior of the implicit conversion case. It terminates the 307 * conversion and returns the current accumulated value of the converted 308 * integer. (NO ERROR) 309 * 310 * 4) Conversion of a null (zero-length) string to an integer is 311 * technically not allowed. However, ACPICA allows this as an ACPI 312 * extension. The conversion returns the value 0. (NO ERROR) 313 * 314 * NOTE: There are no error conditions returned by this function. At the 315 * minimum, a value of zero is returned. 316 * 317 * Current users of this function: 318 * 319 * interpreter - Runtime ASL to_integer operator, as per the ACPI specification 320 * 321 ******************************************************************************/ 322 323 u64 acpi_ut_explicit_strtoul64(char *string) 324 { 325 u64 converted_integer = 0; 326 u32 base = 10; /* Default is decimal */ 327 328 ACPI_FUNCTION_TRACE_STR(ut_explicit_strtoul64, string); 329 330 if (!acpi_ut_remove_whitespace(&string)) { 331 return_VALUE(0); 332 } 333 334 /* 335 * Only Hex and Decimal are supported, as per the ACPI specification. 336 * A "0x" prefix indicates hex; otherwise decimal is assumed. 337 */ 338 if (acpi_ut_detect_hex_prefix(&string)) { 339 base = 16; 340 } 341 342 if (!acpi_ut_remove_leading_zeros(&string)) { 343 return_VALUE(0); 344 } 345 346 /* 347 * Ignore overflow as per the ACPI specification. This is implemented by 348 * ignoring the return status from the conversion functions called below. 349 * On overflow, the input string is simply truncated. 350 */ 351 switch (base) { 352 case 10: 353 default: 354 acpi_ut_convert_decimal_string(string, &converted_integer); 355 break; 356 357 case 16: 358 acpi_ut_convert_hex_string(string, &converted_integer); 359 break; 360 } 361 362 return_VALUE(converted_integer); 363 } 364