1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /******************************************************************************* 3 * 4 * Module Name: utstrtoul64 - String-to-integer conversion support for both 5 * 64-bit and 32-bit integers 6 * 7 ******************************************************************************/ 8 9 #include <acpi/acpi.h> 10 #include "accommon.h" 11 12 #define _COMPONENT ACPI_UTILITIES 13 ACPI_MODULE_NAME("utstrtoul64") 14 15 /******************************************************************************* 16 * 17 * This module contains the top-level string to 64/32-bit unsigned integer 18 * conversion functions: 19 * 20 * 1) A standard strtoul() function that supports 64-bit integers, base 21 * 8/10/16, with integer overflow support. This is used mainly by the 22 * iASL compiler, which implements tighter constraints on integer 23 * constants than the runtime (interpreter) integer-to-string conversions. 24 * 2) Runtime "Explicit conversion" as defined in the ACPI specification. 25 * 3) Runtime "Implicit conversion" as defined in the ACPI specification. 26 * 27 * Current users of this module: 28 * 29 * iASL - Preprocessor (constants and math expressions) 30 * iASL - Main parser, conversion of constants to integers 31 * iASL - Data Table Compiler parser (constants and math expressions) 32 * interpreter - Implicit and explicit conversions, GPE method names 33 * interpreter - Repair code for return values from predefined names 34 * debugger - Command line input string conversion 35 * acpi_dump - ACPI table physical addresses 36 * acpi_exec - Support for namespace overrides 37 * 38 * Notes concerning users of these interfaces: 39 * 40 * acpi_gbl_integer_byte_width is used to set the 32/64 bit limit for explicit 41 * and implicit conversions. This global must be set to the proper width. 42 * For the core ACPICA code, the width depends on the DSDT version. For the 43 * acpi_ut_strtoul64 interface, all conversions are 64 bits. This interface is 44 * used primarily for iASL, where the default width is 64 bits for all parsers, 45 * but error checking is performed later to flag cases where a 64-bit constant 46 * is wrongly defined in a 32-bit DSDT/SSDT. 47 * 48 * In ACPI, the only place where octal numbers are supported is within 49 * the ASL language itself. This is implemented via the main acpi_ut_strtoul64 50 * interface. According the ACPI specification, there is no ACPI runtime 51 * support (explicit/implicit) for octal string conversions. 52 * 53 ******************************************************************************/ 54 /******************************************************************************* 55 * 56 * FUNCTION: acpi_ut_strtoul64 57 * 58 * PARAMETERS: string - Null terminated input string, 59 * must be a valid pointer 60 * return_value - Where the converted integer is 61 * returned. Must be a valid pointer 62 * 63 * RETURN: Status and converted integer. Returns an exception on a 64 * 64-bit numeric overflow 65 * 66 * DESCRIPTION: Convert a string into an unsigned integer. Always performs a 67 * full 64-bit conversion, regardless of the current global 68 * integer width. Supports Decimal, Hex, and Octal strings. 69 * 70 * Current users of this function: 71 * 72 * iASL - Preprocessor (constants and math expressions) 73 * iASL - Main ASL parser, conversion of ASL constants to integers 74 * iASL - Data Table Compiler parser (constants and math expressions) 75 * interpreter - Repair code for return values from predefined names 76 * acpi_dump - ACPI table physical addresses 77 * acpi_exec - Support for namespace overrides 78 * 79 ******************************************************************************/ 80 acpi_status acpi_ut_strtoul64(char *string, u64 *return_value) 81 { 82 acpi_status status = AE_OK; 83 u8 original_bit_width; 84 u32 base = 10; /* Default is decimal */ 85 86 ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string); 87 88 *return_value = 0; 89 90 /* A NULL return string returns a value of zero */ 91 92 if (*string == 0) { 93 return_ACPI_STATUS(AE_OK); 94 } 95 96 if (!acpi_ut_remove_whitespace(&string)) { 97 return_ACPI_STATUS(AE_OK); 98 } 99 100 /* 101 * 1) Check for a hex constant. A "0x" prefix indicates base 16. 102 */ 103 if (acpi_ut_detect_hex_prefix(&string)) { 104 base = 16; 105 } 106 107 /* 108 * 2) Check for an octal constant, defined to be a leading zero 109 * followed by sequence of octal digits (0-7) 110 */ 111 else if (acpi_ut_detect_octal_prefix(&string)) { 112 base = 8; 113 } 114 115 if (!acpi_ut_remove_leading_zeros(&string)) { 116 return_ACPI_STATUS(AE_OK); /* Return value 0 */ 117 } 118 119 /* 120 * Force a full 64-bit conversion. The caller (usually iASL) must 121 * check for a 32-bit overflow later as necessary (If current mode 122 * is 32-bit, meaning a 32-bit DSDT). 123 */ 124 original_bit_width = acpi_gbl_integer_bit_width; 125 acpi_gbl_integer_bit_width = 64; 126 127 /* 128 * Perform the base 8, 10, or 16 conversion. A 64-bit numeric overflow 129 * will return an exception (to allow iASL to flag the statement). 130 */ 131 switch (base) { 132 case 8: 133 status = acpi_ut_convert_octal_string(string, return_value); 134 break; 135 136 case 10: 137 status = acpi_ut_convert_decimal_string(string, return_value); 138 break; 139 140 case 16: 141 default: 142 status = acpi_ut_convert_hex_string(string, return_value); 143 break; 144 } 145 146 /* Only possible exception from above is a 64-bit overflow */ 147 148 acpi_gbl_integer_bit_width = original_bit_width; 149 return_ACPI_STATUS(status); 150 } 151 152 /******************************************************************************* 153 * 154 * FUNCTION: acpi_ut_implicit_strtoul64 155 * 156 * PARAMETERS: string - Null terminated input string, 157 * must be a valid pointer 158 * 159 * RETURN: Converted integer 160 * 161 * DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon 162 * an "implicit conversion" by the ACPI specification. Used by 163 * many ASL operators that require an integer operand, and support 164 * an automatic (implicit) conversion from a string operand 165 * to the final integer operand. The major restriction is that 166 * only hex strings are supported. 167 * 168 * ----------------------------------------------------------------------------- 169 * 170 * Base is always 16, either with or without the 0x prefix. Decimal and 171 * Octal strings are not supported, as per the ACPI specification. 172 * 173 * Examples (both are hex values): 174 * Add ("BA98", Arg0, Local0) 175 * Subtract ("0x12345678", Arg1, Local1) 176 * 177 * Conversion rules as extracted from the ACPI specification: 178 * 179 * The converted integer is initialized to the value zero. 180 * The ASCII string is always interpreted as a hexadecimal constant. 181 * 182 * 1) According to the ACPI specification, a "0x" prefix is not allowed. 183 * However, ACPICA allows this as an ACPI extension on general 184 * principle. (NO ERROR) 185 * 186 * 2) The conversion terminates when the size of an integer is reached 187 * (32 or 64 bits). There are no numeric overflow conditions. (NO ERROR) 188 * 189 * 3) The first non-hex character terminates the conversion and returns 190 * the current accumulated value of the converted integer (NO ERROR). 191 * 192 * 4) Conversion of a null (zero-length) string to an integer is 193 * technically not allowed. However, ACPICA allows this as an ACPI 194 * extension. The conversion returns the value 0. (NO ERROR) 195 * 196 * NOTE: There are no error conditions returned by this function. At 197 * the minimum, a value of zero is returned. 198 * 199 * Current users of this function: 200 * 201 * interpreter - All runtime implicit conversions, as per ACPI specification 202 * iASL - Data Table Compiler parser (constants and math expressions) 203 * 204 ******************************************************************************/ 205 206 u64 acpi_ut_implicit_strtoul64(char *string) 207 { 208 u64 converted_integer = 0; 209 210 ACPI_FUNCTION_TRACE_STR(ut_implicit_strtoul64, string); 211 212 if (!acpi_ut_remove_whitespace(&string)) { 213 return_VALUE(0); 214 } 215 216 /* 217 * Per the ACPI specification, only hexadecimal is supported for 218 * implicit conversions, and the "0x" prefix is "not allowed". 219 * However, allow a "0x" prefix as an ACPI extension. 220 */ 221 acpi_ut_remove_hex_prefix(&string); 222 223 if (!acpi_ut_remove_leading_zeros(&string)) { 224 return_VALUE(0); 225 } 226 227 /* 228 * Ignore overflow as per the ACPI specification. This is implemented by 229 * ignoring the return status from the conversion function called below. 230 * On overflow, the input string is simply truncated. 231 */ 232 acpi_ut_convert_hex_string(string, &converted_integer); 233 return_VALUE(converted_integer); 234 } 235 236 /******************************************************************************* 237 * 238 * FUNCTION: acpi_ut_explicit_strtoul64 239 * 240 * PARAMETERS: string - Null terminated input string, 241 * must be a valid pointer 242 * 243 * RETURN: Converted integer 244 * 245 * DESCRIPTION: Perform a 64-bit conversion with the restrictions placed upon 246 * an "explicit conversion" by the ACPI specification. The 247 * main restriction is that only hex and decimal are supported. 248 * 249 * ----------------------------------------------------------------------------- 250 * 251 * Base is either 10 (default) or 16 (with 0x prefix). Octal (base 8) strings 252 * are not supported, as per the ACPI specification. 253 * 254 * Examples: 255 * to_integer ("1000") Decimal 256 * to_integer ("0xABCD") Hex 257 * 258 * Conversion rules as extracted from the ACPI specification: 259 * 260 * 1) The input string is either a decimal or hexadecimal numeric string. 261 * A hex value must be prefixed by "0x" or it is interpreted as decimal. 262 * 263 * 2) The value must not exceed the maximum of an integer value 264 * (32 or 64 bits). The ACPI specification states the behavior is 265 * "unpredictable", so ACPICA matches the behavior of the implicit 266 * conversion case. There are no numeric overflow conditions. (NO ERROR) 267 * 268 * 3) Behavior on the first non-hex character is not defined by the ACPI 269 * specification (for the to_integer operator), so ACPICA matches the 270 * behavior of the implicit conversion case. It terminates the 271 * conversion and returns the current accumulated value of the converted 272 * integer. (NO ERROR) 273 * 274 * 4) Conversion of a null (zero-length) string to an integer is 275 * technically not allowed. However, ACPICA allows this as an ACPI 276 * extension. The conversion returns the value 0. (NO ERROR) 277 * 278 * NOTE: There are no error conditions returned by this function. At the 279 * minimum, a value of zero is returned. 280 * 281 * Current users of this function: 282 * 283 * interpreter - Runtime ASL to_integer operator, as per the ACPI specification 284 * 285 ******************************************************************************/ 286 287 u64 acpi_ut_explicit_strtoul64(char *string) 288 { 289 u64 converted_integer = 0; 290 u32 base = 10; /* Default is decimal */ 291 292 ACPI_FUNCTION_TRACE_STR(ut_explicit_strtoul64, string); 293 294 if (!acpi_ut_remove_whitespace(&string)) { 295 return_VALUE(0); 296 } 297 298 /* 299 * Only Hex and Decimal are supported, as per the ACPI specification. 300 * A "0x" prefix indicates hex; otherwise decimal is assumed. 301 */ 302 if (acpi_ut_detect_hex_prefix(&string)) { 303 base = 16; 304 } 305 306 if (!acpi_ut_remove_leading_zeros(&string)) { 307 return_VALUE(0); 308 } 309 310 /* 311 * Ignore overflow as per the ACPI specification. This is implemented by 312 * ignoring the return status from the conversion functions called below. 313 * On overflow, the input string is simply truncated. 314 */ 315 switch (base) { 316 case 10: 317 default: 318 acpi_ut_convert_decimal_string(string, &converted_integer); 319 break; 320 321 case 16: 322 acpi_ut_convert_hex_string(string, &converted_integer); 323 break; 324 } 325 326 return_VALUE(converted_integer); 327 } 328