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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 - 2006, 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 /* Special case for root */
89
90 size_needed = 1 + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
91 } else {
92 size_needed =
93 prefix_count + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
94 }
95
96 /*
97 * Allocate a buffer for the name.
98 * This buffer must be deleted by the caller!
99 */
100 name_string = ACPI_MEM_ALLOCATE(size_needed);
101 if (!name_string) {
102 ACPI_ERROR((AE_INFO,
103 "Could not allocate size %d", size_needed));
104 return_PTR(NULL);
105 }
106
107 temp_ptr = name_string;
108
109 /* Set up Root or Parent prefixes if needed */
110
111 if (prefix_count == ACPI_UINT32_MAX) {
112 *temp_ptr++ = AML_ROOT_PREFIX;
113 } else {
114 while (prefix_count--) {
115 *temp_ptr++ = AML_PARENT_PREFIX;
116 }
117 }
118
119 /* Set up Dual or Multi prefixes if needed */
120
121 if (num_name_segs > 2) {
122 /* Set up multi prefixes */
123
124 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
125 *temp_ptr++ = (char)num_name_segs;
126 } else if (2 == num_name_segs) {
127 /* Set up dual prefixes */
128
129 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
130 }
131
132 /*
133 * Terminate string following prefixes. acpi_ex_name_segment() will
134 * append the segment(s)
135 */
136 *temp_ptr = 0;
137
138 return_PTR(name_string);
139}
140
141/*******************************************************************************
142 *
143 * FUNCTION: acpi_ex_name_segment
144 *
145 * PARAMETERS: in_aml_address - Pointer to the name in the AML code
146 * name_string - Where to return the name. The name is appended
147 * to any existing string to form a namepath
148 *
149 * RETURN: Status
150 *
151 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
152 *
153 ******************************************************************************/
154
155static acpi_status acpi_ex_name_segment(u8 ** in_aml_address, char *name_string)
156{
157 char *aml_address = (void *)*in_aml_address;
158 acpi_status status = AE_OK;
159 u32 index;
160 char char_buf[5];
161
162 ACPI_FUNCTION_TRACE("ex_name_segment");
163
164 /*
165 * If first character is a digit, then we know that we aren't looking at a
166 * valid name segment
167 */
168 char_buf[0] = *aml_address;
169
170 if ('0' <= char_buf[0] && char_buf[0] <= '9') {
171 ACPI_ERROR((AE_INFO, "Invalid leading digit: %c", char_buf[0]));
172 return_ACPI_STATUS(AE_CTRL_PENDING);
173 }
174
175 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "Bytes from stream:\n"));
176
177 for (index = 0;
178 (index < ACPI_NAME_SIZE)
179 && (acpi_ut_valid_acpi_character(*aml_address)); index++) {
180 char_buf[index] = *aml_address++;
181 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "%c\n", char_buf[index]));
182 }
183
184 /* Valid name segment */
185
186 if (index == 4) {
187 /* Found 4 valid characters */
188
189 char_buf[4] = '\0';
190
191 if (name_string) {
192 ACPI_STRCAT(name_string, char_buf);
193 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
194 "Appended to - %s\n", name_string));
195 } else {
196 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
197 "No Name string - %s\n", char_buf));
198 }
199 } else if (index == 0) {
200 /*
201 * First character was not a valid name character,
202 * so we are looking at something other than a name.
203 */
204 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
205 "Leading character is not alpha: %02Xh (not a name)\n",
206 char_buf[0]));
207 status = AE_CTRL_PENDING;
208 } else {
209 /*
210 * Segment started with one or more valid characters, but fewer than
211 * the required 4
212 */
213 status = AE_AML_BAD_NAME;
214 ACPI_ERROR((AE_INFO,
215 "Bad character %02x in name, at %p",
216 *aml_address, aml_address));
217 }
218
219 *in_aml_address = ACPI_CAST_PTR(u8, aml_address);
220 return_ACPI_STATUS(status);
221}
222
223/*******************************************************************************
224 *
225 * FUNCTION: acpi_ex_get_name_string
226 *
227 * PARAMETERS: data_type - Object type to be associated with this
228 * name
229 * in_aml_address - Pointer to the namestring in the AML code
230 * out_name_string - Where the namestring is returned
231 * out_name_length - Length of the returned string
232 *
233 * RETURN: Status, namestring and length
234 *
235 * DESCRIPTION: Extract a full namepath from the AML byte stream,
236 * including any prefixes.
237 *
238 ******************************************************************************/
239
240acpi_status
241acpi_ex_get_name_string(acpi_object_type data_type,
242 u8 * in_aml_address,
243 char **out_name_string, u32 * out_name_length)
244{
245 acpi_status status = AE_OK;
246 u8 *aml_address = in_aml_address;
247 char *name_string = NULL;
248 u32 num_segments;
249 u32 prefix_count = 0;
250 u8 has_prefix = FALSE;
251
252 ACPI_FUNCTION_TRACE_PTR("ex_get_name_string", aml_address);
253
254 if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type ||
255 ACPI_TYPE_LOCAL_BANK_FIELD == data_type ||
256 ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
257 /* Disallow prefixes for types associated with field_unit names */
258
259 name_string = acpi_ex_allocate_name_string(0, 1);
260 if (!name_string) {
261 status = AE_NO_MEMORY;
262 } else {
263 status =
264 acpi_ex_name_segment(&aml_address, name_string);
265 }
266 } else {
267 /*
268 * data_type is not a field name.
269 * Examine first character of name for root or parent prefix operators
270 */
271 switch (*aml_address) {
272 case AML_ROOT_PREFIX:
273
274 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
275 "root_prefix(\\) at %p\n",
276 aml_address));
277
278 /*
279 * Remember that we have a root_prefix --
280 * see comment in acpi_ex_allocate_name_string()
281 */
282 aml_address++;
283 prefix_count = ACPI_UINT32_MAX;
284 has_prefix = TRUE;
285 break;
286
287 case AML_PARENT_PREFIX:
288
289 /* Increment past possibly multiple parent prefixes */
290
291 do {
292 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
293 "parent_prefix (^) at %p\n",
294 aml_address));
295
296 aml_address++;
297 prefix_count++;
298
299 } while (*aml_address == AML_PARENT_PREFIX);
300
301 has_prefix = TRUE;
302 break;
303
304 default:
305
306 /* Not a prefix character */
307
308 break;
309 }
310
311 /* Examine first character of name for name segment prefix operator */
312
313 switch (*aml_address) {
314 case AML_DUAL_NAME_PREFIX:
315
316 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
317 "dual_name_prefix at %p\n",
318 aml_address));
319
320 aml_address++;
321 name_string =
322 acpi_ex_allocate_name_string(prefix_count, 2);
323 if (!name_string) {
324 status = AE_NO_MEMORY;
325 break;
326 }
327
328 /* Indicate that we processed a prefix */
329
330 has_prefix = TRUE;
331
332 status =
333 acpi_ex_name_segment(&aml_address, name_string);
334 if (ACPI_SUCCESS(status)) {
335 status =
336 acpi_ex_name_segment(&aml_address,
337 name_string);
338 }
339 break;
340
341 case AML_MULTI_NAME_PREFIX_OP:
342
343 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
344 "multi_name_prefix at %p\n",
345 aml_address));
346
347 /* Fetch count of segments remaining in name path */
348
349 aml_address++;
350 num_segments = *aml_address;
351
352 name_string =
353 acpi_ex_allocate_name_string(prefix_count,
354 num_segments);
355 if (!name_string) {
356 status = AE_NO_MEMORY;
357 break;
358 }
359
360 /* Indicate that we processed a prefix */
361
362 aml_address++;
363 has_prefix = TRUE;
364
365 while (num_segments &&
366 (status =
367 acpi_ex_name_segment(&aml_address,
368 name_string)) == AE_OK) {
369 num_segments--;
370 }
371
372 break;
373
374 case 0:
375
376 /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
377
378 if (prefix_count == ACPI_UINT32_MAX) {
379 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
380 "name_seg is \"\\\" followed by NULL\n"));
381 }
382
383 /* Consume the NULL byte */
384
385 aml_address++;
386 name_string =
387 acpi_ex_allocate_name_string(prefix_count, 0);
388 if (!name_string) {
389 status = AE_NO_MEMORY;
390 break;
391 }
392
393 break;
394
395 default:
396
397 /* Name segment string */
398
399 name_string =
400 acpi_ex_allocate_name_string(prefix_count, 1);
401 if (!name_string) {
402 status = AE_NO_MEMORY;
403 break;
404 }
405
406 status =
407 acpi_ex_name_segment(&aml_address, name_string);
408 break;
409 }
410 }
411
412 if (AE_CTRL_PENDING == status && has_prefix) {
413 /* Ran out of segments after processing a prefix */
414
415 ACPI_ERROR((AE_INFO, "Malformed Name at %p", name_string));
416 status = AE_AML_BAD_NAME;
417 }
418
419 if (ACPI_FAILURE(status)) {
420 if (name_string) {
421 ACPI_MEM_FREE(name_string);
422 }
423 return_ACPI_STATUS(status);
424 }
425
426 *out_name_string = name_string;
427 *out_name_length = (u32) (aml_address - in_aml_address);
428
429 return_ACPI_STATUS(status);
430}