exnames.c revision 306536 
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
54static char *
55AcpiExAllocateNameString (
56    UINT32                  PrefixCount,
57    UINT32                  NumNameSegs);
58
59static ACPI_STATUS
60AcpiExNameSegment (
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
81static char *
82AcpiExAllocateNameString (
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
178static ACPI_STATUS
179AcpiExNameSegment (
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
280ACPI_STATUS
281AcpiExGetNameString (
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