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 - 2019, 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.h"
46 #include "accommon.h"
47 
48 #define _COMPONENT          ACPI_UTILITIES
49         ACPI_MODULE_NAME    ("utstrtoul64")
50 
51 
52 /*******************************************************************************
53  *
54  * This module contains the top-level string to 64/32-bit unsigned integer
55  * conversion functions:
56  *
57  *  1) A standard strtoul() function that supports 64-bit integers, base
58  *     8/10/16, with integer overflow support. This is used mainly by the
59  *     iASL compiler, which implements tighter constraints on integer
60  *     constants than the runtime (interpreter) integer-to-string conversions.
61  *  2) Runtime "Explicit conversion" as defined in the ACPI specification.
62  *  3) Runtime "Implicit conversion" as defined in the ACPI specification.
63  *
64  * Current users of this module:
65  *
66  *  iASL        - Preprocessor (constants and math expressions)
67  *  iASL        - Main parser, conversion of constants to integers
68  *  iASL        - Data Table Compiler parser (constants and math expressions)
69  *  Interpreter - Implicit and explicit conversions, GPE method names
70  *  Interpreter - Repair code for return values from predefined names
71  *  Debugger    - Command line input string conversion
72  *  AcpiDump    - ACPI table physical addresses
73  *  AcpiExec    - Support for namespace overrides
74  *
75  * Notes concerning users of these interfaces:
76  *
77  * AcpiGbl_IntegerByteWidth is used to set the 32/64 bit limit for explicit
78  * and implicit conversions. This global must be set to the proper width.
79  * For the core ACPICA code, the width depends on the DSDT version. For the
80  * AcpiUtStrtoul64 interface, all conversions are 64 bits. This interface is
81  * used primarily for iASL, where the default width is 64 bits for all parsers,
82  * but error checking is performed later to flag cases where a 64-bit constant
83  * is wrongly defined in a 32-bit DSDT/SSDT.
84  *
85  * In ACPI, the only place where octal numbers are supported is within
86  * the ASL language itself. This is implemented via the main AcpiUtStrtoul64
87  * interface. According the ACPI specification, there is no ACPI runtime
88  * support (explicit/implicit) for octal string conversions.
89  *
90  ******************************************************************************/
91 
92 
93 /*******************************************************************************
94  *
95  * FUNCTION:    AcpiUtStrtoul64
96  *
97  * PARAMETERS:  String                  - Null terminated input string,
98  *                                        must be a valid pointer
99  *              ReturnValue             - Where the converted integer is
100  *                                        returned. Must be a valid pointer
101  *
102  * RETURN:      Status and converted integer. Returns an exception on a
103  *              64-bit numeric overflow
104  *
105  * DESCRIPTION: Convert a string into an unsigned integer. Always performs a
106  *              full 64-bit conversion, regardless of the current global
107  *              integer width. Supports Decimal, Hex, and Octal strings.
108  *
109  * Current users of this function:
110  *
111  *  iASL        - Preprocessor (constants and math expressions)
112  *  iASL        - Main ASL parser, conversion of ASL constants to integers
113  *  iASL        - Data Table Compiler parser (constants and math expressions)
114  *  Interpreter - Repair code for return values from predefined names
115  *  AcpiDump    - ACPI table physical addresses
116  *  AcpiExec    - Support for namespace overrides
117  *
118  ******************************************************************************/
119 
120 ACPI_STATUS
121 AcpiUtStrtoul64 (
122     char                    *String,
123     UINT64                  *ReturnValue)
124 {
125     ACPI_STATUS             Status = AE_OK;
126     UINT8                   OriginalBitWidth;
127     UINT32                  Base = 10;          /* Default is decimal */
128 
129 
130     ACPI_FUNCTION_TRACE_STR (UtStrtoul64, String);
131 
132 
133     *ReturnValue = 0;
134 
135     /* A NULL return string returns a value of zero */
136 
137     if (*String == 0)
138     {
139         return_ACPI_STATUS (AE_OK);
140     }
141 
142     if (!AcpiUtRemoveWhitespace (&String))
143     {
144         return_ACPI_STATUS (AE_OK);
145     }
146 
147     /*
148      * 1) Check for a hex constant. A "0x" prefix indicates base 16.
149      */
150     if (AcpiUtDetectHexPrefix (&String))
151     {
152         Base = 16;
153     }
154 
155     /*
156      * 2) Check for an octal constant, defined to be a leading zero
157      * followed by sequence of octal digits (0-7)
158      */
159     else if (AcpiUtDetectOctalPrefix (&String))
160     {
161         Base = 8;
162     }
163 
164     if (!AcpiUtRemoveLeadingZeros (&String))
165     {
166         return_ACPI_STATUS (AE_OK);     /* Return value 0 */
167     }
168 
169     /*
170      * Force a full 64-bit conversion. The caller (usually iASL) must
171      * check for a 32-bit overflow later as necessary (If current mode
172      * is 32-bit, meaning a 32-bit DSDT).
173      */
174     OriginalBitWidth = AcpiGbl_IntegerBitWidth;
175     AcpiGbl_IntegerBitWidth = 64;
176 
177     /*
178      * Perform the base 8, 10, or 16 conversion. A 64-bit numeric overflow
179      * will return an exception (to allow iASL to flag the statement).
180      */
181     switch (Base)
182     {
183     case 8:
184         Status = AcpiUtConvertOctalString (String, ReturnValue);
185         break;
186 
187     case 10:
188         Status = AcpiUtConvertDecimalString (String, ReturnValue);
189         break;
190 
191     case 16:
192     default:
193         Status = AcpiUtConvertHexString (String, ReturnValue);
194         break;
195     }
196 
197     /* Only possible exception from above is a 64-bit overflow */
198 
199     AcpiGbl_IntegerBitWidth = OriginalBitWidth;
200     return_ACPI_STATUS (Status);
201 }
202 
203 
204 /*******************************************************************************
205  *
206  * FUNCTION:    AcpiUtImplicitStrtoul64
207  *
208  * PARAMETERS:  String                  - Null terminated input string,
209  *                                        must be a valid pointer
210  *
211  * RETURN:      Converted integer
212  *
213  * DESCRIPTION: Perform a 64-bit conversion with restrictions placed upon
214  *              an "implicit conversion" by the ACPI specification. Used by
215  *              many ASL operators that require an integer operand, and support
216  *              an automatic (implicit) conversion from a string operand
217  *              to the final integer operand. The major restriction is that
218  *              only hex strings are supported.
219  *
220  * -----------------------------------------------------------------------------
221  *
222  * Base is always 16, either with or without the 0x prefix. Decimal and
223  * Octal strings are not supported, as per the ACPI specification.
224  *
225  * Examples (both are hex values):
226  *      Add ("BA98", Arg0, Local0)
227  *      Subtract ("0x12345678", Arg1, Local1)
228  *
229  * Conversion rules as extracted from the ACPI specification:
230  *
231  *  The converted integer is initialized to the value zero.
232  *  The ASCII string is always interpreted as a hexadecimal constant.
233  *
234  *  1)  According to the ACPI specification, a "0x" prefix is not allowed.
235  *      However, ACPICA allows this as an ACPI extension on general
236  *      principle. (NO ERROR)
237  *
238  *  2)  The conversion terminates when the size of an integer is reached
239  *      (32 or 64 bits). There are no numeric overflow conditions. (NO ERROR)
240  *
241  *  3)  The first non-hex character terminates the conversion and returns
242  *      the current accumulated value of the converted integer (NO ERROR).
243  *
244  *  4)  Conversion of a null (zero-length) string to an integer is
245  *      technically not allowed. However, ACPICA allows this as an ACPI
246  *      extension. The conversion returns the value 0. (NO ERROR)
247  *
248  * NOTE: There are no error conditions returned by this function. At
249  * the minimum, a value of zero is returned.
250  *
251  * Current users of this function:
252  *
253  *  Interpreter - All runtime implicit conversions, as per ACPI specification
254  *  iASL        - Data Table Compiler parser (constants and math expressions)
255  *
256  ******************************************************************************/
257 
258 UINT64
259 AcpiUtImplicitStrtoul64 (
260     char                    *String)
261 {
262     UINT64                  ConvertedInteger = 0;
263 
264 
265     ACPI_FUNCTION_TRACE_STR (UtImplicitStrtoul64, String);
266 
267 
268     if (!AcpiUtRemoveWhitespace (&String))
269     {
270         return_VALUE (0);
271     }
272 
273     /*
274      * Per the ACPI specification, only hexadecimal is supported for
275      * implicit conversions, and the "0x" prefix is "not allowed".
276      * However, allow a "0x" prefix as an ACPI extension.
277      */
278     AcpiUtRemoveHexPrefix (&String);
279 
280     if (!AcpiUtRemoveLeadingZeros (&String))
281     {
282         return_VALUE (0);
283     }
284 
285     /*
286      * Ignore overflow as per the ACPI specification. This is implemented by
287      * ignoring the return status from the conversion function called below.
288      * On overflow, the input string is simply truncated.
289      */
290     AcpiUtConvertHexString (String, &ConvertedInteger);
291     return_VALUE (ConvertedInteger);
292 }
293 
294 
295 /*******************************************************************************
296  *
297  * FUNCTION:    AcpiUtExplicitStrtoul64
298  *
299  * PARAMETERS:  String                  - Null terminated input string,
300  *                                        must be a valid pointer
301  *
302  * RETURN:      Converted integer
303  *
304  * DESCRIPTION: Perform a 64-bit conversion with the restrictions placed upon
305  *              an "explicit conversion" by the ACPI specification. The
306  *              main restriction is that only hex and decimal are supported.
307  *
308  * -----------------------------------------------------------------------------
309  *
310  * Base is either 10 (default) or 16 (with 0x prefix). Octal (base 8) strings
311  * are not supported, as per the ACPI specification.
312  *
313  * Examples:
314  *      ToInteger ("1000")      Decimal
315  *      ToInteger ("0xABCD")    Hex
316  *
317  * Conversion rules as extracted from the ACPI specification:
318  *
319  *  1)  The input string is either a decimal or hexadecimal numeric string.
320  *      A hex value must be prefixed by "0x" or it is interpreted as decimal.
321  *
322  *  2)  The value must not exceed the maximum of an integer value
323  *      (32 or 64 bits). The ACPI specification states the behavior is
324  *      "unpredictable", so ACPICA matches the behavior of the implicit
325  *      conversion case. There are no numeric overflow conditions. (NO ERROR)
326  *
327  *  3)  Behavior on the first non-hex character is not defined by the ACPI
328  *      specification (for the ToInteger operator), so ACPICA matches the
329  *      behavior of the implicit conversion case. It terminates the
330  *      conversion and returns the current accumulated value of the converted
331  *      integer. (NO ERROR)
332  *
333  *  4)  Conversion of a null (zero-length) string to an integer is
334  *      technically not allowed. However, ACPICA allows this as an ACPI
335  *      extension. The conversion returns the value 0. (NO ERROR)
336  *
337  * NOTE: There are no error conditions returned by this function. At the
338  * minimum, a value of zero is returned.
339  *
340  * Current users of this function:
341  *
342  *  Interpreter - Runtime ASL ToInteger operator, as per the ACPI specification
343  *
344  ******************************************************************************/
345 
346 UINT64
347 AcpiUtExplicitStrtoul64 (
348     char                    *String)
349 {
350     UINT64                  ConvertedInteger = 0;
351     UINT32                  Base = 10;          /* Default is decimal */
352 
353 
354     ACPI_FUNCTION_TRACE_STR (UtExplicitStrtoul64, String);
355 
356 
357     if (!AcpiUtRemoveWhitespace (&String))
358     {
359         return_VALUE (0);
360     }
361 
362     /*
363      * Only Hex and Decimal are supported, as per the ACPI specification.
364      * A "0x" prefix indicates hex; otherwise decimal is assumed.
365      */
366     if (AcpiUtDetectHexPrefix (&String))
367     {
368         Base = 16;
369     }
370 
371     if (!AcpiUtRemoveLeadingZeros (&String))
372     {
373         return_VALUE (0);
374     }
375 
376     /*
377      * Ignore overflow as per the ACPI specification. This is implemented by
378      * ignoring the return status from the conversion functions called below.
379      * On overflow, the input string is simply truncated.
380      */
381     switch (Base)
382     {
383     case 10:
384     default:
385         AcpiUtConvertDecimalString (String, &ConvertedInteger);
386         break;
387 
388     case 16:
389         AcpiUtConvertHexString (String, &ConvertedInteger);
390         break;
391     }
392 
393     return_VALUE (ConvertedInteger);
394 }
395