exnames.c revision 250838 
1/******************************************************************************
2 *
3 * Module Name: exnames - interpreter/scanner name load/execute
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2013, 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#define __EXNAMES_C__
45
46#include <contrib/dev/acpica/include/acpi.h>
47#include <contrib/dev/acpica/include/accommon.h>
48#include <contrib/dev/acpica/include/acinterp.h>
49#include <contrib/dev/acpica/include/amlcode.h>
50
51#define _COMPONENT          ACPI_EXECUTER
52        ACPI_MODULE_NAME    ("exnames")
53
54/* Local prototypes */
55
56static char *
57AcpiExAllocateNameString (
58    UINT32                  PrefixCount,
59    UINT32                  NumNameSegs);
60
61static ACPI_STATUS
62AcpiExNameSegment (
63    UINT8                   **InAmlAddress,
64    char                    *NameString);
65
66
67/*******************************************************************************
68 *
69 * FUNCTION:    AcpiExAllocateNameString
70 *
71 * PARAMETERS:  PrefixCount         - Count of parent levels. Special cases:
72 *                                    (-1)==root,  0==none
73 *              NumNameSegs         - count of 4-character name segments
74 *
75 * RETURN:      A pointer to the allocated string segment. This segment must
76 *              be deleted by the caller.
77 *
78 * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
79 *              string is long enough, and set up prefix if any.
80 *
81 ******************************************************************************/
82
83static char *
84AcpiExAllocateNameString (
85    UINT32                  PrefixCount,
86    UINT32                  NumNameSegs)
87{
88    char                    *TempPtr;
89    char                    *NameString;
90    UINT32                   SizeNeeded;
91
92    ACPI_FUNCTION_TRACE (ExAllocateNameString);
93
94
95    /*
96     * Allow room for all \ and ^ prefixes, all segments and a MultiNamePrefix.
97     * Also, one byte for the null terminator.
98     * This may actually be somewhat longer than needed.
99     */
100    if (PrefixCount == ACPI_UINT32_MAX)
101    {
102        /* Special case for root */
103
104        SizeNeeded = 1 + (ACPI_NAME_SIZE * NumNameSegs) + 2 + 1;
105    }
106    else
107    {
108        SizeNeeded = PrefixCount + (ACPI_NAME_SIZE * NumNameSegs) + 2 + 1;
109    }
110
111    /*
112     * Allocate a buffer for the name.
113     * This buffer must be deleted by the caller!
114     */
115    NameString = ACPI_ALLOCATE (SizeNeeded);
116    if (!NameString)
117    {
118        ACPI_ERROR ((AE_INFO,
119            "Could not allocate size %u", SizeNeeded));
120        return_PTR (NULL);
121    }
122
123    TempPtr = NameString;
124
125    /* Set up Root or Parent prefixes if needed */
126
127    if (PrefixCount == ACPI_UINT32_MAX)
128    {
129        *TempPtr++ = AML_ROOT_PREFIX;
130    }
131    else
132    {
133        while (PrefixCount--)
134        {
135            *TempPtr++ = AML_PARENT_PREFIX;
136        }
137    }
138
139
140    /* Set up Dual or Multi prefixes if needed */
141
142    if (NumNameSegs > 2)
143    {
144        /* Set up multi prefixes   */
145
146        *TempPtr++ = AML_MULTI_NAME_PREFIX_OP;
147        *TempPtr++ = (char) NumNameSegs;
148    }
149    else if (2 == NumNameSegs)
150    {
151        /* Set up dual prefixes */
152
153        *TempPtr++ = AML_DUAL_NAME_PREFIX;
154    }
155
156    /*
157     * Terminate string following prefixes. AcpiExNameSegment() will
158     * append the segment(s)
159     */
160    *TempPtr = 0;
161
162    return_PTR (NameString);
163}
164
165/*******************************************************************************
166 *
167 * FUNCTION:    AcpiExNameSegment
168 *
169 * PARAMETERS:  InAmlAddress    - Pointer to the name in the AML code
170 *              NameString      - Where to return the name. The name is appended
171 *                                to any existing string to form a namepath
172 *
173 * RETURN:      Status
174 *
175 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
176 *
177 ******************************************************************************/
178
179static ACPI_STATUS
180AcpiExNameSegment (
181    UINT8                   **InAmlAddress,
182    char                    *NameString)
183{
184    char                    *AmlAddress = (void *) *InAmlAddress;
185    ACPI_STATUS             Status = AE_OK;
186    UINT32                  Index;
187    char                    CharBuf[5];
188
189
190    ACPI_FUNCTION_TRACE (ExNameSegment);
191
192
193    /*
194     * If first character is a digit, then we know that we aren't looking at a
195     * valid name segment
196     */
197    CharBuf[0] = *AmlAddress;
198
199    if ('0' <= CharBuf[0] && CharBuf[0] <= '9')
200    {
201        ACPI_ERROR ((AE_INFO, "Invalid leading digit: %c", CharBuf[0]));
202        return_ACPI_STATUS (AE_CTRL_PENDING);
203    }
204
205    ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "Bytes from stream:\n"));
206
207    for (Index = 0;
208        (Index < ACPI_NAME_SIZE) && (AcpiUtValidAcpiChar (*AmlAddress, 0));
209        Index++)
210    {
211        CharBuf[Index] = *AmlAddress++;
212        ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", CharBuf[Index]));
213    }
214
215
216    /* Valid name segment  */
217
218    if (Index == 4)
219    {
220        /* Found 4 valid characters */
221
222        CharBuf[4] = '\0';
223
224        if (NameString)
225        {
226            ACPI_STRCAT (NameString, CharBuf);
227            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
228                "Appended to - %s\n", NameString));
229        }
230        else
231        {
232            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
233                "No Name string - %s\n", CharBuf));
234        }
235    }
236    else if (Index == 0)
237    {
238        /*
239         * First character was not a valid name character,
240         * so we are looking at something other than a name.
241         */
242        ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
243            "Leading character is not alpha: %02Xh (not a name)\n",
244            CharBuf[0]));
245        Status = AE_CTRL_PENDING;
246    }
247    else
248    {
249        /*
250         * Segment started with one or more valid characters, but fewer than
251         * the required 4
252         */
253        Status = AE_AML_BAD_NAME;
254        ACPI_ERROR ((AE_INFO,
255            "Bad character 0x%02x in name, at %p",
256            *AmlAddress, AmlAddress));
257    }
258
259    *InAmlAddress = ACPI_CAST_PTR (UINT8, AmlAddress);
260    return_ACPI_STATUS (Status);
261}
262
263
264/*******************************************************************************
265 *
266 * FUNCTION:    AcpiExGetNameString
267 *
268 * PARAMETERS:  DataType            - Object type to be associated with this
269 *                                    name
270 *              InAmlAddress        - Pointer to the namestring in the AML code
271 *              OutNameString       - Where the namestring is returned
272 *              OutNameLength       - Length of the returned string
273 *
274 * RETURN:      Status, namestring and length
275 *
276 * DESCRIPTION: Extract a full namepath from the AML byte stream,
277 *              including any prefixes.
278 *
279 ******************************************************************************/
280
281ACPI_STATUS
282AcpiExGetNameString (
283    ACPI_OBJECT_TYPE        DataType,
284    UINT8                   *InAmlAddress,
285    char                    **OutNameString,
286    UINT32                  *OutNameLength)
287{
288    ACPI_STATUS             Status = AE_OK;
289    UINT8                   *AmlAddress = InAmlAddress;
290    char                    *NameString = NULL;
291    UINT32                  NumSegments;
292    UINT32                  PrefixCount = 0;
293    BOOLEAN                 HasPrefix = FALSE;
294
295
296    ACPI_FUNCTION_TRACE_PTR (ExGetNameString, AmlAddress);
297
298
299    if (ACPI_TYPE_LOCAL_REGION_FIELD == DataType   ||
300        ACPI_TYPE_LOCAL_BANK_FIELD == DataType     ||
301        ACPI_TYPE_LOCAL_INDEX_FIELD == DataType)
302    {
303        /* Disallow prefixes for types associated with FieldUnit names */
304
305        NameString = AcpiExAllocateNameString (0, 1);
306        if (!NameString)
307        {
308            Status = AE_NO_MEMORY;
309        }
310        else
311        {
312            Status = AcpiExNameSegment (&AmlAddress, NameString);
313        }
314    }
315    else
316    {
317        /*
318         * DataType is not a field name.
319         * Examine first character of name for root or parent prefix operators
320         */
321        switch (*AmlAddress)
322        {
323        case AML_ROOT_PREFIX:
324
325            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "RootPrefix(\\) at %p\n",
326                AmlAddress));
327
328            /*
329             * Remember that we have a RootPrefix --
330             * see comment in AcpiExAllocateNameString()
331             */
332            AmlAddress++;
333            PrefixCount = ACPI_UINT32_MAX;
334            HasPrefix = TRUE;
335            break;
336
337        case AML_PARENT_PREFIX:
338
339            /* Increment past possibly multiple parent prefixes */
340
341            do
342            {
343                ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "ParentPrefix (^) at %p\n",
344                    AmlAddress));
345
346                AmlAddress++;
347                PrefixCount++;
348
349            } while (*AmlAddress == AML_PARENT_PREFIX);
350
351            HasPrefix = TRUE;
352            break;
353
354        default:
355
356            /* Not a prefix character */
357
358            break;
359        }
360
361        /* Examine first character of name for name segment prefix operator */
362
363        switch (*AmlAddress)
364        {
365        case AML_DUAL_NAME_PREFIX:
366
367            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "DualNamePrefix at %p\n",
368                AmlAddress));
369
370            AmlAddress++;
371            NameString = AcpiExAllocateNameString (PrefixCount, 2);
372            if (!NameString)
373            {
374                Status = AE_NO_MEMORY;
375                break;
376            }
377
378            /* Indicate that we processed a prefix */
379
380            HasPrefix = TRUE;
381
382            Status = AcpiExNameSegment (&AmlAddress, NameString);
383            if (ACPI_SUCCESS (Status))
384            {
385                Status = AcpiExNameSegment (&AmlAddress, NameString);
386            }
387            break;
388
389        case AML_MULTI_NAME_PREFIX_OP:
390
391            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "MultiNamePrefix at %p\n",
392                AmlAddress));
393
394            /* Fetch count of segments remaining in name path */
395
396            AmlAddress++;
397            NumSegments = *AmlAddress;
398
399            NameString = AcpiExAllocateNameString (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