xref: /freebsd/sys/contrib/dev/acpica/components/executer/exnames.c (revision fed1ca4b719c56c930f2259d80663cd34be812bb)
1 /******************************************************************************
2  *
3  * Module Name: exnames - interpreter/scanner name load/execute
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2016, 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 <contrib/dev/acpica/include/acpi.h>
45 #include <contrib/dev/acpica/include/accommon.h>
46 #include <contrib/dev/acpica/include/acinterp.h>
47 #include <contrib/dev/acpica/include/amlcode.h>
48 
49 #define _COMPONENT          ACPI_EXECUTER
50         ACPI_MODULE_NAME    ("exnames")
51 
52 /* Local prototypes */
53 
54 static char *
55 AcpiExAllocateNameString (
56     UINT32                  PrefixCount,
57     UINT32                  NumNameSegs);
58 
59 static ACPI_STATUS
60 AcpiExNameSegment (
61     UINT8                   **InAmlAddress,
62     char                    *NameString);
63 
64 
65 /*******************************************************************************
66  *
67  * FUNCTION:    AcpiExAllocateNameString
68  *
69  * PARAMETERS:  PrefixCount         - Count of parent levels. Special cases:
70  *                                    (-1)==root,  0==none
71  *              NumNameSegs         - count of 4-character name segments
72  *
73  * RETURN:      A pointer to the allocated string segment. This segment must
74  *              be deleted by the caller.
75  *
76  * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
77  *              string is long enough, and set up prefix if any.
78  *
79  ******************************************************************************/
80 
81 static char *
82 AcpiExAllocateNameString (
83     UINT32                  PrefixCount,
84     UINT32                  NumNameSegs)
85 {
86     char                    *TempPtr;
87     char                    *NameString;
88     UINT32                   SizeNeeded;
89 
90     ACPI_FUNCTION_TRACE (ExAllocateNameString);
91 
92 
93     /*
94      * Allow room for all \ and ^ prefixes, all segments and a MultiNamePrefix.
95      * Also, one byte for the null terminator.
96      * This may actually be somewhat longer than needed.
97      */
98     if (PrefixCount == ACPI_UINT32_MAX)
99     {
100         /* Special case for root */
101 
102         SizeNeeded = 1 + (ACPI_NAME_SIZE * NumNameSegs) + 2 + 1;
103     }
104     else
105     {
106         SizeNeeded = PrefixCount + (ACPI_NAME_SIZE * NumNameSegs) + 2 + 1;
107     }
108 
109     /*
110      * Allocate a buffer for the name.
111      * This buffer must be deleted by the caller!
112      */
113     NameString = ACPI_ALLOCATE (SizeNeeded);
114     if (!NameString)
115     {
116         ACPI_ERROR ((AE_INFO,
117             "Could not allocate size %u", SizeNeeded));
118         return_PTR (NULL);
119     }
120 
121     TempPtr = NameString;
122 
123     /* Set up Root or Parent prefixes if needed */
124 
125     if (PrefixCount == ACPI_UINT32_MAX)
126     {
127         *TempPtr++ = AML_ROOT_PREFIX;
128     }
129     else
130     {
131         while (PrefixCount--)
132         {
133             *TempPtr++ = AML_PARENT_PREFIX;
134         }
135     }
136 
137 
138     /* Set up Dual or Multi prefixes if needed */
139 
140     if (NumNameSegs > 2)
141     {
142         /* Set up multi prefixes   */
143 
144         *TempPtr++ = AML_MULTI_NAME_PREFIX_OP;
145         *TempPtr++ = (char) NumNameSegs;
146     }
147     else if (2 == NumNameSegs)
148     {
149         /* Set up dual prefixes */
150 
151         *TempPtr++ = AML_DUAL_NAME_PREFIX;
152     }
153 
154     /*
155      * Terminate string following prefixes. AcpiExNameSegment() will
156      * append the segment(s)
157      */
158     *TempPtr = 0;
159 
160     return_PTR (NameString);
161 }
162 
163 
164 /*******************************************************************************
165  *
166  * FUNCTION:    AcpiExNameSegment
167  *
168  * PARAMETERS:  InAmlAddress    - Pointer to the name in the AML code
169  *              NameString      - Where to return the name. The name is appended
170  *                                to any existing string to form a namepath
171  *
172  * RETURN:      Status
173  *
174  * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
175  *
176  ******************************************************************************/
177 
178 static ACPI_STATUS
179 AcpiExNameSegment (
180     UINT8                   **InAmlAddress,
181     char                    *NameString)
182 {
183     char                    *AmlAddress = (void *) *InAmlAddress;
184     ACPI_STATUS             Status = AE_OK;
185     UINT32                  Index;
186     char                    CharBuf[5];
187 
188 
189     ACPI_FUNCTION_TRACE (ExNameSegment);
190 
191 
192     /*
193      * If first character is a digit, then we know that we aren't looking
194      * at a valid name segment
195      */
196     CharBuf[0] = *AmlAddress;
197 
198     if ('0' <= CharBuf[0] && CharBuf[0] <= '9')
199     {
200         ACPI_ERROR ((AE_INFO, "Invalid leading digit: %c", CharBuf[0]));
201         return_ACPI_STATUS (AE_CTRL_PENDING);
202     }
203 
204     ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "Bytes from stream:\n"));
205 
206     for (Index = 0;
207         (Index < ACPI_NAME_SIZE) && (AcpiUtValidNameChar (*AmlAddress, 0));
208         Index++)
209     {
210         CharBuf[Index] = *AmlAddress++;
211         ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", CharBuf[Index]));
212     }
213 
214 
215     /* Valid name segment  */
216 
217     if (Index == 4)
218     {
219         /* Found 4 valid characters */
220 
221         CharBuf[4] = '\0';
222 
223         if (NameString)
224         {
225             strcat (NameString, CharBuf);
226             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
227                 "Appended to - %s\n", NameString));
228         }
229         else
230         {
231             ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
232                 "No Name string - %s\n", CharBuf));
233         }
234     }
235     else if (Index == 0)
236     {
237         /*
238          * First character was not a valid name character,
239          * so we are looking at something other than a name.
240          */
241         ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
242             "Leading character is not alpha: %02Xh (not a name)\n",
243             CharBuf[0]));
244         Status = AE_CTRL_PENDING;
245     }
246     else
247     {
248         /*
249          * Segment started with one or more valid characters, but fewer than
250          * the required 4
251          */
252         Status = AE_AML_BAD_NAME;
253         ACPI_ERROR ((AE_INFO,
254             "Bad character 0x%02x in name, at %p",
255             *AmlAddress, AmlAddress));
256     }
257 
258     *InAmlAddress = ACPI_CAST_PTR (UINT8, AmlAddress);
259     return_ACPI_STATUS (Status);
260 }
261 
262 
263 /*******************************************************************************
264  *
265  * FUNCTION:    AcpiExGetNameString
266  *
267  * PARAMETERS:  DataType            - Object type to be associated with this
268  *                                    name
269  *              InAmlAddress        - Pointer to the namestring in the AML code
270  *              OutNameString       - Where the namestring is returned
271  *              OutNameLength       - Length of the returned string
272  *
273  * RETURN:      Status, namestring and length
274  *
275  * DESCRIPTION: Extract a full namepath from the AML byte stream,
276  *              including any prefixes.
277  *
278  ******************************************************************************/
279 
280 ACPI_STATUS
281 AcpiExGetNameString (
282     ACPI_OBJECT_TYPE        DataType,
283     UINT8                   *InAmlAddress,
284     char                    **OutNameString,
285     UINT32                  *OutNameLength)
286 {
287     ACPI_STATUS             Status = AE_OK;
288     UINT8                   *AmlAddress = InAmlAddress;
289     char                    *NameString = NULL;
290     UINT32                  NumSegments;
291     UINT32                  PrefixCount = 0;
292     BOOLEAN                 HasPrefix = FALSE;
293 
294 
295     ACPI_FUNCTION_TRACE_PTR (ExGetNameString, AmlAddress);
296 
297 
298     if (ACPI_TYPE_LOCAL_REGION_FIELD == DataType   ||
299         ACPI_TYPE_LOCAL_BANK_FIELD == DataType     ||
300         ACPI_TYPE_LOCAL_INDEX_FIELD == DataType)
301     {
302         /* Disallow prefixes for types associated with FieldUnit names */
303 
304         NameString = AcpiExAllocateNameString (0, 1);
305         if (!NameString)
306         {
307             Status = AE_NO_MEMORY;
308         }
309         else
310         {
311             Status = AcpiExNameSegment (&AmlAddress, NameString);
312         }
313     }
314     else
315     {
316         /*
317          * DataType is not a field name.
318          * Examine first character of name for root or parent prefix operators
319          */
320         switch (*AmlAddress)
321         {
322         case AML_ROOT_PREFIX:
323 
324             ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "RootPrefix(\\) at %p\n",
325                 AmlAddress));
326 
327             /*
328              * Remember that we have a RootPrefix --
329              * see comment in AcpiExAllocateNameString()
330              */
331             AmlAddress++;
332             PrefixCount = ACPI_UINT32_MAX;
333             HasPrefix = TRUE;
334             break;
335 
336         case AML_PARENT_PREFIX:
337 
338             /* Increment past possibly multiple parent prefixes */
339 
340             do
341             {
342                 ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "ParentPrefix (^) at %p\n",
343                     AmlAddress));
344 
345                 AmlAddress++;
346                 PrefixCount++;
347 
348             } while (*AmlAddress == AML_PARENT_PREFIX);
349 
350             HasPrefix = TRUE;
351             break;
352 
353         default:
354 
355             /* Not a prefix character */
356 
357             break;
358         }
359 
360         /* Examine first character of name for name segment prefix operator */
361 
362         switch (*AmlAddress)
363         {
364         case AML_DUAL_NAME_PREFIX:
365 
366             ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "DualNamePrefix at %p\n",
367                 AmlAddress));
368 
369             AmlAddress++;
370             NameString = AcpiExAllocateNameString (PrefixCount, 2);
371             if (!NameString)
372             {
373                 Status = AE_NO_MEMORY;
374                 break;
375             }
376 
377             /* Indicate that we processed a prefix */
378 
379             HasPrefix = TRUE;
380 
381             Status = AcpiExNameSegment (&AmlAddress, NameString);
382             if (ACPI_SUCCESS (Status))
383             {
384                 Status = AcpiExNameSegment (&AmlAddress, NameString);
385             }
386             break;
387 
388         case AML_MULTI_NAME_PREFIX_OP:
389 
390             ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "MultiNamePrefix at %p\n",
391                 AmlAddress));
392 
393             /* Fetch count of segments remaining in name path */
394 
395             AmlAddress++;
396             NumSegments = *AmlAddress;
397 
398             NameString = AcpiExAllocateNameString (
399                 PrefixCount, NumSegments);
400             if (!NameString)
401             {
402                 Status = AE_NO_MEMORY;
403                 break;
404             }
405 
406             /* Indicate that we processed a prefix */
407 
408             AmlAddress++;
409             HasPrefix = TRUE;
410 
411             while (NumSegments &&
412                     (Status = AcpiExNameSegment (&AmlAddress, NameString)) ==
413                         AE_OK)
414             {
415                 NumSegments--;
416             }
417 
418             break;
419 
420         case 0:
421 
422             /* NullName valid as of 8-12-98 ASL/AML Grammar Update */
423 
424             if (PrefixCount == ACPI_UINT32_MAX)
425             {
426                 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
427                     "NameSeg is \"\\\" followed by NULL\n"));
428             }
429 
430             /* Consume the NULL byte */
431 
432             AmlAddress++;
433             NameString = AcpiExAllocateNameString (PrefixCount, 0);
434             if (!NameString)
435             {
436                 Status = AE_NO_MEMORY;
437                 break;
438             }
439 
440             break;
441 
442         default:
443 
444             /* Name segment string */
445 
446             NameString = AcpiExAllocateNameString (PrefixCount, 1);
447             if (!NameString)
448             {
449                 Status = AE_NO_MEMORY;
450                 break;
451             }
452 
453             Status = AcpiExNameSegment (&AmlAddress, NameString);
454             break;
455         }
456     }
457 
458     if (AE_CTRL_PENDING == Status && HasPrefix)
459     {
460         /* Ran out of segments after processing a prefix */
461 
462         ACPI_ERROR ((AE_INFO,
463             "Malformed Name at %p", NameString));
464         Status = AE_AML_BAD_NAME;
465     }
466 
467     if (ACPI_FAILURE (Status))
468     {
469         if (NameString)
470         {
471             ACPI_FREE (NameString);
472         }
473         return_ACPI_STATUS (Status);
474     }
475 
476     *OutNameString = NameString;
477     *OutNameLength = (UINT32) (AmlAddress - InAmlAddress);
478 
479     return_ACPI_STATUS (Status);
480 }
481