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Linux kernel mirror (for testing)
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1
2/******************************************************************************
3 *
4 * Module Name: exnames - interpreter/scanner name load/execute
5 *
6 *****************************************************************************/
7
8/*
9 * Copyright (C) 2000 - 2007, R. Byron Moore
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/acpi.h>
46#include <acpi/acinterp.h>
47#include <acpi/amlcode.h>
48
49#define _COMPONENT ACPI_EXECUTER
50ACPI_MODULE_NAME("exnames")
51
52/* Local prototypes */
53static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs);
54
55static acpi_status
56acpi_ex_name_segment(u8 ** in_aml_address, char *name_string);
57
58/*******************************************************************************
59 *
60 * FUNCTION: acpi_ex_allocate_name_string
61 *
62 * PARAMETERS: prefix_count - Count of parent levels. Special cases:
63 * (-1)==root, 0==none
64 * num_name_segs - count of 4-character name segments
65 *
66 * RETURN: A pointer to the allocated string segment. This segment must
67 * be deleted by the caller.
68 *
69 * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
70 * string is long enough, and set up prefix if any.
71 *
72 ******************************************************************************/
73
74static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs)
75{
76 char *temp_ptr;
77 char *name_string;
78 u32 size_needed;
79
80 ACPI_FUNCTION_TRACE(ex_allocate_name_string);
81
82 /*
83 * Allow room for all \ and ^ prefixes, all segments and a multi_name_prefix.
84 * Also, one byte for the null terminator.
85 * This may actually be somewhat longer than needed.
86 */
87 if (prefix_count == ACPI_UINT32_MAX) {
88
89 /* Special case for root */
90
91 size_needed = 1 + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
92 } else {
93 size_needed =
94 prefix_count + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
95 }
96
97 /*
98 * Allocate a buffer for the name.
99 * This buffer must be deleted by the caller!
100 */
101 name_string = ACPI_ALLOCATE(size_needed);
102 if (!name_string) {
103 ACPI_ERROR((AE_INFO,
104 "Could not allocate size %d", size_needed));
105 return_PTR(NULL);
106 }
107
108 temp_ptr = name_string;
109
110 /* Set up Root or Parent prefixes if needed */
111
112 if (prefix_count == ACPI_UINT32_MAX) {
113 *temp_ptr++ = AML_ROOT_PREFIX;
114 } else {
115 while (prefix_count--) {
116 *temp_ptr++ = AML_PARENT_PREFIX;
117 }
118 }
119
120 /* Set up Dual or Multi prefixes if needed */
121
122 if (num_name_segs > 2) {
123
124 /* Set up multi prefixes */
125
126 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
127 *temp_ptr++ = (char)num_name_segs;
128 } else if (2 == num_name_segs) {
129
130 /* Set up dual prefixes */
131
132 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
133 }
134
135 /*
136 * Terminate string following prefixes. acpi_ex_name_segment() will
137 * append the segment(s)
138 */
139 *temp_ptr = 0;
140
141 return_PTR(name_string);
142}
143
144/*******************************************************************************
145 *
146 * FUNCTION: acpi_ex_name_segment
147 *
148 * PARAMETERS: in_aml_address - Pointer to the name in the AML code
149 * name_string - Where to return the name. The name is appended
150 * to any existing string to form a namepath
151 *
152 * RETURN: Status
153 *
154 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
155 *
156 ******************************************************************************/
157
158static acpi_status acpi_ex_name_segment(u8 ** in_aml_address, char *name_string)
159{
160 char *aml_address = (void *)*in_aml_address;
161 acpi_status status = AE_OK;
162 u32 index;
163 char char_buf[5];
164
165 ACPI_FUNCTION_TRACE(ex_name_segment);
166
167 /*
168 * If first character is a digit, then we know that we aren't looking at a
169 * valid name segment
170 */
171 char_buf[0] = *aml_address;
172
173 if ('0' <= char_buf[0] && char_buf[0] <= '9') {
174 ACPI_ERROR((AE_INFO, "Invalid leading digit: %c", char_buf[0]));
175 return_ACPI_STATUS(AE_CTRL_PENDING);
176 }
177
178 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "Bytes from stream:\n"));
179
180 for (index = 0; (index < ACPI_NAME_SIZE)
181 && (acpi_ut_valid_acpi_char(*aml_address, 0)); index++) {
182 char_buf[index] = *aml_address++;
183 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "%c\n", char_buf[index]));
184 }
185
186 /* Valid name segment */
187
188 if (index == 4) {
189
190 /* Found 4 valid characters */
191
192 char_buf[4] = '\0';
193
194 if (name_string) {
195 ACPI_STRCAT(name_string, char_buf);
196 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
197 "Appended to - %s\n", name_string));
198 } else {
199 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
200 "No Name string - %s\n", char_buf));
201 }
202 } else if (index == 0) {
203 /*
204 * First character was not a valid name character,
205 * so we are looking at something other than a name.
206 */
207 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
208 "Leading character is not alpha: %02Xh (not a name)\n",
209 char_buf[0]));
210 status = AE_CTRL_PENDING;
211 } else {
212 /*
213 * Segment started with one or more valid characters, but fewer than
214 * the required 4
215 */
216 status = AE_AML_BAD_NAME;
217 ACPI_ERROR((AE_INFO,
218 "Bad character %02x in name, at %p",
219 *aml_address, aml_address));
220 }
221
222 *in_aml_address = ACPI_CAST_PTR(u8, aml_address);
223 return_ACPI_STATUS(status);
224}
225
226/*******************************************************************************
227 *
228 * FUNCTION: acpi_ex_get_name_string
229 *
230 * PARAMETERS: data_type - Object type to be associated with this
231 * name
232 * in_aml_address - Pointer to the namestring in the AML code
233 * out_name_string - Where the namestring is returned
234 * out_name_length - Length of the returned string
235 *
236 * RETURN: Status, namestring and length
237 *
238 * DESCRIPTION: Extract a full namepath from the AML byte stream,
239 * including any prefixes.
240 *
241 ******************************************************************************/
242
243acpi_status
244acpi_ex_get_name_string(acpi_object_type data_type,
245 u8 * in_aml_address,
246 char **out_name_string, u32 * out_name_length)
247{
248 acpi_status status = AE_OK;
249 u8 *aml_address = in_aml_address;
250 char *name_string = NULL;
251 u32 num_segments;
252 u32 prefix_count = 0;
253 u8 has_prefix = FALSE;
254
255 ACPI_FUNCTION_TRACE_PTR(ex_get_name_string, aml_address);
256
257 if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type ||
258 ACPI_TYPE_LOCAL_BANK_FIELD == data_type ||
259 ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
260
261 /* Disallow prefixes for types associated with field_unit names */
262
263 name_string = acpi_ex_allocate_name_string(0, 1);
264 if (!name_string) {
265 status = AE_NO_MEMORY;
266 } else {
267 status =
268 acpi_ex_name_segment(&aml_address, name_string);
269 }
270 } else {
271 /*
272 * data_type is not a field name.
273 * Examine first character of name for root or parent prefix operators
274 */
275 switch (*aml_address) {
276 case AML_ROOT_PREFIX:
277
278 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
279 "RootPrefix(\\) at %p\n",
280 aml_address));
281
282 /*
283 * Remember that we have a root_prefix --
284 * see comment in acpi_ex_allocate_name_string()
285 */
286 aml_address++;
287 prefix_count = ACPI_UINT32_MAX;
288 has_prefix = TRUE;
289 break;
290
291 case AML_PARENT_PREFIX:
292
293 /* Increment past possibly multiple parent prefixes */
294
295 do {
296 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
297 "ParentPrefix (^) at %p\n",
298 aml_address));
299
300 aml_address++;
301 prefix_count++;
302
303 } while (*aml_address == AML_PARENT_PREFIX);
304
305 has_prefix = TRUE;
306 break;
307
308 default:
309
310 /* Not a prefix character */
311
312 break;
313 }
314
315 /* Examine first character of name for name segment prefix operator */
316
317 switch (*aml_address) {
318 case AML_DUAL_NAME_PREFIX:
319
320 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
321 "DualNamePrefix at %p\n",
322 aml_address));
323
324 aml_address++;
325 name_string =
326 acpi_ex_allocate_name_string(prefix_count, 2);
327 if (!name_string) {
328 status = AE_NO_MEMORY;
329 break;
330 }
331
332 /* Indicate that we processed a prefix */
333
334 has_prefix = TRUE;
335
336 status =
337 acpi_ex_name_segment(&aml_address, name_string);
338 if (ACPI_SUCCESS(status)) {
339 status =
340 acpi_ex_name_segment(&aml_address,
341 name_string);
342 }
343 break;
344
345 case AML_MULTI_NAME_PREFIX_OP:
346
347 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
348 "MultiNamePrefix at %p\n",
349 aml_address));
350
351 /* Fetch count of segments remaining in name path */
352
353 aml_address++;
354 num_segments = *aml_address;
355
356 name_string =
357 acpi_ex_allocate_name_string(prefix_count,
358 num_segments);
359 if (!name_string) {
360 status = AE_NO_MEMORY;
361 break;
362 }
363
364 /* Indicate that we processed a prefix */
365
366 aml_address++;
367 has_prefix = TRUE;
368
369 while (num_segments &&
370 (status =
371 acpi_ex_name_segment(&aml_address,
372 name_string)) == AE_OK) {
373 num_segments--;
374 }
375
376 break;
377
378 case 0:
379
380 /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
381
382 if (prefix_count == ACPI_UINT32_MAX) {
383 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
384 "NameSeg is \"\\\" followed by NULL\n"));
385 }
386
387 /* Consume the NULL byte */
388
389 aml_address++;
390 name_string =
391 acpi_ex_allocate_name_string(prefix_count, 0);
392 if (!name_string) {
393 status = AE_NO_MEMORY;
394 break;
395 }
396
397 break;
398
399 default:
400
401 /* Name segment string */
402
403 name_string =
404 acpi_ex_allocate_name_string(prefix_count, 1);
405 if (!name_string) {
406 status = AE_NO_MEMORY;
407 break;
408 }
409
410 status =
411 acpi_ex_name_segment(&aml_address, name_string);
412 break;
413 }
414 }
415
416 if (AE_CTRL_PENDING == status && has_prefix) {
417
418 /* Ran out of segments after processing a prefix */
419
420 ACPI_ERROR((AE_INFO, "Malformed Name at %p", name_string));
421 status = AE_AML_BAD_NAME;
422 }
423
424 if (ACPI_FAILURE(status)) {
425 if (name_string) {
426 ACPI_FREE(name_string);
427 }
428 return_ACPI_STATUS(status);
429 }
430
431 *out_name_string = name_string;
432 *out_name_length = (u32) (aml_address - in_aml_address);
433
434 return_ACPI_STATUS(status);
435}