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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 : 0 : acpi_status acpi_ut_strtoul64(char *string, u64 *return_value)
81 : : {
82 : 0 : acpi_status status = AE_OK;
83 : 0 : u8 original_bit_width;
84 : 0 : u32 base = 10; /* Default is decimal */
85 : :
86 : 0 : ACPI_FUNCTION_TRACE_STR(ut_strtoul64, string);
87 : :
88 : 0 : *return_value = 0;
89 : :
90 : : /* A NULL return string returns a value of zero */
91 : :
92 [ # # ]: 0 : if (*string == 0) {
93 : : return_ACPI_STATUS(AE_OK);
94 : : }
95 : :
96 [ # # ]: 0 : 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 [ # # ]: 0 : 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 [ # # ]: 0 : else if (acpi_ut_detect_octal_prefix(&string)) {
112 : 0 : base = 8;
113 : : }
114 : :
115 [ # # ]: 0 : 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 : 0 : original_bit_width = acpi_gbl_integer_bit_width;
125 : 0 : 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 [ # # # ]: 0 : switch (base) {
132 : 0 : case 8:
133 : 0 : status = acpi_ut_convert_octal_string(string, return_value);
134 : 0 : break;
135 : :
136 : 0 : case 10:
137 : 0 : status = acpi_ut_convert_decimal_string(string, return_value);
138 : 0 : break;
139 : :
140 : 0 : case 16:
141 : : default:
142 : 0 : status = acpi_ut_convert_hex_string(string, return_value);
143 : 0 : break;
144 : : }
145 : :
146 : : /* Only possible exception from above is a 64-bit overflow */
147 : :
148 : 0 : acpi_gbl_integer_bit_width = original_bit_width;
149 : 0 : 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 : 0 : u64 acpi_ut_implicit_strtoul64(char *string)
207 : : {
208 : 0 : u64 converted_integer = 0;
209 : :
210 : 0 : ACPI_FUNCTION_TRACE_STR(ut_implicit_strtoul64, string);
211 : :
212 [ # # ]: 0 : 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 : 0 : acpi_ut_remove_hex_prefix(&string);
222 : :
223 [ # # ]: 0 : 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 : 0 : acpi_ut_convert_hex_string(string, &converted_integer);
233 : 0 : 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 : 0 : u64 acpi_ut_explicit_strtoul64(char *string)
288 : : {
289 : 0 : u64 converted_integer = 0;
290 : 0 : u32 base = 10; /* Default is decimal */
291 : :
292 : 0 : ACPI_FUNCTION_TRACE_STR(ut_explicit_strtoul64, string);
293 : :
294 [ # # ]: 0 : 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 [ # # ]: 0 : if (acpi_ut_detect_hex_prefix(&string)) {
303 : 0 : base = 16;
304 : : }
305 : :
306 [ # # ]: 0 : 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 [ # # ]: 0 : switch (base) {
316 : 0 : case 10:
317 : : default:
318 : 0 : acpi_ut_convert_decimal_string(string, &converted_integer);
319 : 0 : break;
320 : :
321 : 0 : case 16:
322 : 0 : acpi_ut_convert_hex_string(string, &converted_integer);
323 : 0 : break;
324 : : }
325 : :
326 : 0 : return_VALUE(converted_integer);
327 : : }
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