exnames.c revision 281075 
1/******************************************************************************
2 *
3 * Module Name: exnames - interpreter/scanner name load/execute
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2015, 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 * FUNCTION:    AcpiExNameSegment
166 *
167 * PARAMETERS:  InAmlAddress    - Pointer to the name in the AML code
168 *              NameString      - Where to return the name. The name is appended
169 *                                to any existing string to form a namepath
170 *
171 * RETURN:      Status
172 *
173 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
174 *
175 ******************************************************************************/
176
177static ACPI_STATUS
178AcpiExNameSegment (
179    UINT8                   **InAmlAddress,
180    char                    *NameString)
181{
182    char                    *AmlAddress = (void *) *InAmlAddress;
183    ACPI_STATUS             Status = AE_OK;
184    UINT32                  Index;
185    char                    CharBuf[5];
186
187
188    ACPI_FUNCTION_TRACE (ExNameSegment);
189
190
191    /*
192     * If first character is a digit, then we know that we aren't looking at a
193     * valid name segment
194     */
195    CharBuf[0] = *AmlAddress;
196
197    if ('0' <= CharBuf[0] && CharBuf[0] <= '9')
198    {
199        ACPI_ERROR ((AE_INFO, "Invalid leading digit: %c", CharBuf[0]));
200        return_ACPI_STATUS (AE_CTRL_PENDING);
201    }
202
203    ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "Bytes from stream:\n"));
204
205    for (Index = 0;
206        (Index < ACPI_NAME_SIZE) && (AcpiUtValidAcpiChar (*AmlAddress, 0));
207        Index++)
208    {
209        CharBuf[Index] = *AmlAddress++;
210        ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "%c\n", CharBuf[Index]));
211    }
212
213
214    /* Valid name segment  */
215
216    if (Index == 4)
217    {
218        /* Found 4 valid characters */
219
220        CharBuf[4] = '\0';
221
222        if (NameString)
223        {
224            ACPI_STRCAT (NameString, CharBuf);
225            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
226                "Appended to - %s\n", NameString));
227        }
228        else
229        {
230            ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
231                "No Name string - %s\n", CharBuf));
232        }
233    }
234    else if (Index == 0)
235    {
236        /*
237         * First character was not a valid name character,
238         * so we are looking at something other than a name.
239         */
240        ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
241            "Leading character is not alpha: %02Xh (not a name)\n",
242            CharBuf[0]));
243        Status = AE_CTRL_PENDING;
244    }
245    else
246    {
247        /*
248         * Segment started with one or more valid characters, but fewer than
249         * the required 4
250         */
251        Status = AE_AML_BAD_NAME;
252        ACPI_ERROR ((AE_INFO,
253            "Bad character 0x%02x in name, at %p",
254            *AmlAddress, AmlAddress));
255    }
256
257    *InAmlAddress = ACPI_CAST_PTR (UINT8, AmlAddress);
258    return_ACPI_STATUS (Status);
259}
260
261
262/*******************************************************************************
263 *
264 * FUNCTION:    AcpiExGetNameString
265 *
266 * PARAMETERS:  DataType            - Object type to be associated with this
267 *                                    name
268 *              InAmlAddress        - Pointer to the namestring in the AML code
269 *              OutNameString       - Where the namestring is returned
270 *              OutNameLength       - Length of the returned string
271 *
272 * RETURN:      Status, namestring and length
273 *
274 * DESCRIPTION: Extract a full namepath from the AML byte stream,
275 *              including any prefixes.
276 *
277 ******************************************************************************/
278
279ACPI_STATUS
280AcpiExGetNameString (
281    ACPI_OBJECT_TYPE        DataType,
282    UINT8                   *InAmlAddress,
283    char                    **OutNameString,
284    UINT32                  *OutNameLength)
285{
286    ACPI_STATUS             Status = AE_OK;
287    UINT8                   *AmlAddress = InAmlAddress;
288    char                    *NameString = NULL;
289    UINT32                  NumSegments;
290    UINT32                  PrefixCount = 0;
291    BOOLEAN                 HasPrefix = FALSE;
292
293
294    ACPI_FUNCTION_TRACE_PTR (ExGetNameString, AmlAddress);
295
296
297    if (ACPI_TYPE_LOCAL_REGION_FIELD == DataType   ||
298        ACPI_TYPE_LOCAL_BANK_FIELD == DataType     ||
299        ACPI_TYPE_LOCAL_INDEX_FIELD == DataType)
300    {
301        /* Disallow prefixes for types associated with FieldUnit names */
302
303        NameString = AcpiExAllocateNameString (0, 1);
304        if (!NameString)
305        {
306            Status = AE_NO_MEMORY;
307        }
308        else
309        {
310            Status = AcpiExNameSegment (&AmlAddress, NameString);
311        }
312    }
313    else
314    {
315        /*
316         * DataType is not a field name.
317         * Examine first character of name for root or parent prefix operators
318         */
319        switch (*AmlAddress)
320        {
321        case AML_ROOT_PREFIX:
322
323            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "RootPrefix(\\) at %p\n",
324                AmlAddress));
325
326            /*
327             * Remember that we have a RootPrefix --
328             * see comment in AcpiExAllocateNameString()
329             */
330            AmlAddress++;
331            PrefixCount = ACPI_UINT32_MAX;
332            HasPrefix = TRUE;
333            break;
334
335        case AML_PARENT_PREFIX:
336
337            /* Increment past possibly multiple parent prefixes */
338
339            do
340            {
341                ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "ParentPrefix (^) at %p\n",
342                    AmlAddress));
343
344                AmlAddress++;
345                PrefixCount++;
346
347            } while (*AmlAddress == AML_PARENT_PREFIX);
348
349            HasPrefix = TRUE;
350            break;
351
352        default:
353
354            /* Not a prefix character */
355
356            break;
357        }
358
359        /* Examine first character of name for name segment prefix operator */
360
361        switch (*AmlAddress)
362        {
363        case AML_DUAL_NAME_PREFIX:
364
365            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "DualNamePrefix at %p\n",
366                AmlAddress));
367
368            AmlAddress++;
369            NameString = AcpiExAllocateNameString (PrefixCount, 2);
370            if (!NameString)
371            {
372                Status = AE_NO_MEMORY;
373                break;
374            }
375
376            /* Indicate that we processed a prefix */
377
378            HasPrefix = TRUE;
379
380            Status = AcpiExNameSegment (&AmlAddress, NameString);
381            if (ACPI_SUCCESS (Status))
382            {
383                Status = AcpiExNameSegment (&AmlAddress, NameString);
384            }
385            break;
386
387        case AML_MULTI_NAME_PREFIX_OP:
388
389            ACPI_DEBUG_PRINT ((ACPI_DB_LOAD, "MultiNamePrefix at %p\n",
390                AmlAddress));
391
392            /* Fetch count of segments remaining in name path */
393
394            AmlAddress++;
395            NumSegments = *AmlAddress;
396
397            NameString = AcpiExAllocateNameString (PrefixCount, NumSegments);
398            if (!NameString)
399            {
400                Status = AE_NO_MEMORY;
401                break;
402            }
403
404            /* Indicate that we processed a prefix */
405
406            AmlAddress++;
407            HasPrefix = TRUE;
408
409            while (NumSegments &&
410                    (Status = AcpiExNameSegment (&AmlAddress, NameString)) ==
411                        AE_OK)
412            {
413                NumSegments--;
414            }
415
416            break;
417
418        case 0:
419
420            /* NullName valid as of 8-12-98 ASL/AML Grammar Update */
421
422            if (PrefixCount == ACPI_UINT32_MAX)
423            {
424                ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
425                    "NameSeg is \"\\\" followed by NULL\n"));
426            }
427
428            /* Consume the NULL byte */
429
430            AmlAddress++;
431            NameString = AcpiExAllocateNameString (PrefixCount, 0);
432            if (!NameString)
433            {
434                Status = AE_NO_MEMORY;
435                break;
436            }
437
438            break;
439
440        default:
441
442            /* Name segment string */
443
444            NameString = AcpiExAllocateNameString (PrefixCount, 1);
445            if (!NameString)
446            {
447                Status = AE_NO_MEMORY;
448                break;
449            }
450
451            Status = AcpiExNameSegment (&AmlAddress, NameString);
452            break;
453        }
454    }
455
456    if (AE_CTRL_PENDING == Status && HasPrefix)
457    {
458        /* Ran out of segments after processing a prefix */
459
460        ACPI_ERROR ((AE_INFO,
461            "Malformed Name at %p", NameString));
462        Status = AE_AML_BAD_NAME;
463    }
464
465    if (ACPI_FAILURE (Status))
466    {
467        if (NameString)
468        {
469            ACPI_FREE (NameString);
470        }
471        return_ACPI_STATUS (Status);
472    }
473
474    *OutNameString = NameString;
475    *OutNameLength = (UINT32) (AmlAddress - InAmlAddress);
476
477    return_ACPI_STATUS (Status);
478}
479