1
2 /******************************************************************************
3 *
4 * Module Name: exnames - interpreter/scanner name load/execute
5 *
6 *****************************************************************************/
7
8 /*
9 * Copyright (C) 2000 - 2011, Intel Corp.
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 "accommon.h"
47 #include "acinterp.h"
48 #include "amlcode.h"
49
50 #define _COMPONENT ACPI_EXECUTER
51 ACPI_MODULE_NAME("exnames")
52
53 /* Local prototypes */
54 static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs);
55
56 static acpi_status
57 acpi_ex_name_segment(u8 ** in_aml_address, char *name_string);
58
59 /*******************************************************************************
60 *
61 * FUNCTION: acpi_ex_allocate_name_string
62 *
63 * PARAMETERS: prefix_count - Count of parent levels. Special cases:
64 * (-1)==root, 0==none
65 * num_name_segs - count of 4-character name segments
66 *
67 * RETURN: A pointer to the allocated string segment. This segment must
68 * be deleted by the caller.
69 *
70 * DESCRIPTION: Allocate a buffer for a name string. Ensure allocated name
71 * string is long enough, and set up prefix if any.
72 *
73 ******************************************************************************/
74
acpi_ex_allocate_name_string(u32 prefix_count,u32 num_name_segs)75 static char *acpi_ex_allocate_name_string(u32 prefix_count, u32 num_name_segs)
76 {
77 char *temp_ptr;
78 char *name_string;
79 u32 size_needed;
80
81 ACPI_FUNCTION_TRACE(ex_allocate_name_string);
82
83 /*
84 * Allow room for all \ and ^ prefixes, all segments and a multi_name_prefix.
85 * Also, one byte for the null terminator.
86 * This may actually be somewhat longer than needed.
87 */
88 if (prefix_count == ACPI_UINT32_MAX) {
89
90 /* Special case for root */
91
92 size_needed = 1 + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
93 } else {
94 size_needed =
95 prefix_count + (ACPI_NAME_SIZE * num_name_segs) + 2 + 1;
96 }
97
98 /*
99 * Allocate a buffer for the name.
100 * This buffer must be deleted by the caller!
101 */
102 name_string = ACPI_ALLOCATE(size_needed);
103 if (!name_string) {
104 ACPI_ERROR((AE_INFO,
105 "Could not allocate size %u", size_needed));
106 return_PTR(NULL);
107 }
108
109 temp_ptr = name_string;
110
111 /* Set up Root or Parent prefixes if needed */
112
113 if (prefix_count == ACPI_UINT32_MAX) {
114 *temp_ptr++ = AML_ROOT_PREFIX;
115 } else {
116 while (prefix_count--) {
117 *temp_ptr++ = AML_PARENT_PREFIX;
118 }
119 }
120
121 /* Set up Dual or Multi prefixes if needed */
122
123 if (num_name_segs > 2) {
124
125 /* Set up multi prefixes */
126
127 *temp_ptr++ = AML_MULTI_NAME_PREFIX_OP;
128 *temp_ptr++ = (char)num_name_segs;
129 } else if (2 == num_name_segs) {
130
131 /* Set up dual prefixes */
132
133 *temp_ptr++ = AML_DUAL_NAME_PREFIX;
134 }
135
136 /*
137 * Terminate string following prefixes. acpi_ex_name_segment() will
138 * append the segment(s)
139 */
140 *temp_ptr = 0;
141
142 return_PTR(name_string);
143 }
144
145 /*******************************************************************************
146 *
147 * FUNCTION: acpi_ex_name_segment
148 *
149 * PARAMETERS: in_aml_address - Pointer to the name in the AML code
150 * name_string - Where to return the name. The name is appended
151 * to any existing string to form a namepath
152 *
153 * RETURN: Status
154 *
155 * DESCRIPTION: Extract an ACPI name (4 bytes) from the AML byte stream
156 *
157 ******************************************************************************/
158
acpi_ex_name_segment(u8 ** in_aml_address,char * name_string)159 static acpi_status acpi_ex_name_segment(u8 ** in_aml_address, char *name_string)
160 {
161 char *aml_address = (void *)*in_aml_address;
162 acpi_status status = AE_OK;
163 u32 index;
164 char char_buf[5];
165
166 ACPI_FUNCTION_TRACE(ex_name_segment);
167
168 /*
169 * If first character is a digit, then we know that we aren't looking at a
170 * valid name segment
171 */
172 char_buf[0] = *aml_address;
173
174 if ('0' <= char_buf[0] && char_buf[0] <= '9') {
175 ACPI_ERROR((AE_INFO, "Invalid leading digit: %c", char_buf[0]));
176 return_ACPI_STATUS(AE_CTRL_PENDING);
177 }
178
179 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "Bytes from stream:\n"));
180
181 for (index = 0; (index < ACPI_NAME_SIZE)
182 && (acpi_ut_valid_acpi_char(*aml_address, 0)); index++) {
183 char_buf[index] = *aml_address++;
184 ACPI_DEBUG_PRINT((ACPI_DB_LOAD, "%c\n", char_buf[index]));
185 }
186
187 /* Valid name segment */
188
189 if (index == 4) {
190
191 /* Found 4 valid characters */
192
193 char_buf[4] = '\0';
194
195 if (name_string) {
196 ACPI_STRCAT(name_string, char_buf);
197 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
198 "Appended to - %s\n", name_string));
199 } else {
200 ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
201 "No Name string - %s\n", char_buf));
202 }
203 } else if (index == 0) {
204 /*
205 * First character was not a valid name character,
206 * so we are looking at something other than a name.
207 */
208 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
209 "Leading character is not alpha: %02Xh (not a name)\n",
210 char_buf[0]));
211 status = AE_CTRL_PENDING;
212 } else {
213 /*
214 * Segment started with one or more valid characters, but fewer than
215 * the required 4
216 */
217 status = AE_AML_BAD_NAME;
218 ACPI_ERROR((AE_INFO,
219 "Bad character 0x%02x in name, at %p",
220 *aml_address, aml_address));
221 }
222
223 *in_aml_address = ACPI_CAST_PTR(u8, aml_address);
224 return_ACPI_STATUS(status);
225 }
226
227 /*******************************************************************************
228 *
229 * FUNCTION: acpi_ex_get_name_string
230 *
231 * PARAMETERS: data_type - Object type to be associated with this
232 * name
233 * in_aml_address - Pointer to the namestring in the AML code
234 * out_name_string - Where the namestring is returned
235 * out_name_length - Length of the returned string
236 *
237 * RETURN: Status, namestring and length
238 *
239 * DESCRIPTION: Extract a full namepath from the AML byte stream,
240 * including any prefixes.
241 *
242 ******************************************************************************/
243
244 acpi_status
acpi_ex_get_name_string(acpi_object_type data_type,u8 * in_aml_address,char ** out_name_string,u32 * out_name_length)245 acpi_ex_get_name_string(acpi_object_type data_type,
246 u8 * in_aml_address,
247 char **out_name_string, u32 * out_name_length)
248 {
249 acpi_status status = AE_OK;
250 u8 *aml_address = in_aml_address;
251 char *name_string = NULL;
252 u32 num_segments;
253 u32 prefix_count = 0;
254 u8 has_prefix = FALSE;
255
256 ACPI_FUNCTION_TRACE_PTR(ex_get_name_string, aml_address);
257
258 if (ACPI_TYPE_LOCAL_REGION_FIELD == data_type ||
259 ACPI_TYPE_LOCAL_BANK_FIELD == data_type ||
260 ACPI_TYPE_LOCAL_INDEX_FIELD == data_type) {
261
262 /* Disallow prefixes for types associated with field_unit names */
263
264 name_string = acpi_ex_allocate_name_string(0, 1);
265 if (!name_string) {
266 status = AE_NO_MEMORY;
267 } else {
268 status =
269 acpi_ex_name_segment(&aml_address, name_string);
270 }
271 } else {
272 /*
273 * data_type is not a field name.
274 * Examine first character of name for root or parent prefix operators
275 */
276 switch (*aml_address) {
277 case AML_ROOT_PREFIX:
278
279 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
280 "RootPrefix(\\) at %p\n",
281 aml_address));
282
283 /*
284 * Remember that we have a root_prefix --
285 * see comment in acpi_ex_allocate_name_string()
286 */
287 aml_address++;
288 prefix_count = ACPI_UINT32_MAX;
289 has_prefix = TRUE;
290 break;
291
292 case AML_PARENT_PREFIX:
293
294 /* Increment past possibly multiple parent prefixes */
295
296 do {
297 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
298 "ParentPrefix (^) at %p\n",
299 aml_address));
300
301 aml_address++;
302 prefix_count++;
303
304 } while (*aml_address == AML_PARENT_PREFIX);
305
306 has_prefix = TRUE;
307 break;
308
309 default:
310
311 /* Not a prefix character */
312
313 break;
314 }
315
316 /* Examine first character of name for name segment prefix operator */
317
318 switch (*aml_address) {
319 case AML_DUAL_NAME_PREFIX:
320
321 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
322 "DualNamePrefix at %p\n",
323 aml_address));
324
325 aml_address++;
326 name_string =
327 acpi_ex_allocate_name_string(prefix_count, 2);
328 if (!name_string) {
329 status = AE_NO_MEMORY;
330 break;
331 }
332
333 /* Indicate that we processed a prefix */
334
335 has_prefix = TRUE;
336
337 status =
338 acpi_ex_name_segment(&aml_address, name_string);
339 if (ACPI_SUCCESS(status)) {
340 status =
341 acpi_ex_name_segment(&aml_address,
342 name_string);
343 }
344 break;
345
346 case AML_MULTI_NAME_PREFIX_OP:
347
348 ACPI_DEBUG_PRINT((ACPI_DB_LOAD,
349 "MultiNamePrefix at %p\n",
350 aml_address));
351
352 /* Fetch count of segments remaining in name path */
353
354 aml_address++;
355 num_segments = *aml_address;
356
357 name_string =
358 acpi_ex_allocate_name_string(prefix_count,
359 num_segments);
360 if (!name_string) {
361 status = AE_NO_MEMORY;
362 break;
363 }
364
365 /* Indicate that we processed a prefix */
366
367 aml_address++;
368 has_prefix = TRUE;
369
370 while (num_segments &&
371 (status =
372 acpi_ex_name_segment(&aml_address,
373 name_string)) == AE_OK) {
374 num_segments--;
375 }
376
377 break;
378
379 case 0:
380
381 /* null_name valid as of 8-12-98 ASL/AML Grammar Update */
382
383 if (prefix_count == ACPI_UINT32_MAX) {
384 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
385 "NameSeg is \"\\\" followed by NULL\n"));
386 }
387
388 /* Consume the NULL byte */
389
390 aml_address++;
391 name_string =
392 acpi_ex_allocate_name_string(prefix_count, 0);
393 if (!name_string) {
394 status = AE_NO_MEMORY;
395 break;
396 }
397
398 break;
399
400 default:
401
402 /* Name segment string */
403
404 name_string =
405 acpi_ex_allocate_name_string(prefix_count, 1);
406 if (!name_string) {
407 status = AE_NO_MEMORY;
408 break;
409 }
410
411 status =
412 acpi_ex_name_segment(&aml_address, name_string);
413 break;
414 }
415 }
416
417 if (AE_CTRL_PENDING == status && has_prefix) {
418
419 /* Ran out of segments after processing a prefix */
420
421 ACPI_ERROR((AE_INFO, "Malformed Name at %p", name_string));
422 status = AE_AML_BAD_NAME;
423 }
424
425 if (ACPI_FAILURE(status)) {
426 if (name_string) {
427 ACPI_FREE(name_string);
428 }
429 return_ACPI_STATUS(status);
430 }
431
432 *out_name_string = name_string;
433 *out_name_length = (u32) (aml_address - in_aml_address);
434
435 return_ACPI_STATUS(status);
436 }
437