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1 : : // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 : : /******************************************************************************
3 : : *
4 : : * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
5 : : *
6 : : * Copyright (C) 2000 - 2020, Intel Corp.
7 : : *
8 : : *****************************************************************************/
9 : :
10 : : #include <acpi/acpi.h>
11 : : #include "accommon.h"
12 : : #include "acdispat.h"
13 : : #include "acinterp.h"
14 : : #include "acnamesp.h"
15 : : #include "acparser.h"
16 : : #include "amlcode.h"
17 : : #include "acdebug.h"
18 : :
19 : : #define _COMPONENT ACPI_DISPATCHER
20 : : ACPI_MODULE_NAME("dsmethod")
21 : :
22 : : /* Local prototypes */
23 : : static acpi_status
24 : : acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
25 : : union acpi_parse_object **out_op);
26 : :
27 : : static acpi_status
28 : : acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
29 : :
30 : : /*******************************************************************************
31 : : *
32 : : * FUNCTION: acpi_ds_auto_serialize_method
33 : : *
34 : : * PARAMETERS: node - Namespace Node of the method
35 : : * obj_desc - Method object attached to node
36 : : *
37 : : * RETURN: Status
38 : : *
39 : : * DESCRIPTION: Parse a control method AML to scan for control methods that
40 : : * need serialization due to the creation of named objects.
41 : : *
42 : : * NOTE: It is a bit of overkill to mark all such methods serialized, since
43 : : * there is only a problem if the method actually blocks during execution.
44 : : * A blocking operation is, for example, a Sleep() operation, or any access
45 : : * to an operation region. However, it is probably not possible to easily
46 : : * detect whether a method will block or not, so we simply mark all suspicious
47 : : * methods as serialized.
48 : : *
49 : : * NOTE2: This code is essentially a generic routine for parsing a single
50 : : * control method.
51 : : *
52 : : ******************************************************************************/
53 : :
54 : : acpi_status
55 : 884 : acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
56 : : union acpi_operand_object *obj_desc)
57 : : {
58 : 884 : acpi_status status;
59 : 884 : union acpi_parse_object *op = NULL;
60 : 884 : struct acpi_walk_state *walk_state;
61 : :
62 : 884 : ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
63 : :
64 : : ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
65 : : "Method auto-serialization parse [%4.4s] %p\n",
66 : 884 : acpi_ut_get_node_name(node), node));
67 : :
68 : : /* Create/Init a root op for the method parse tree */
69 : :
70 : 884 : op = acpi_ps_alloc_op(AML_METHOD_OP, obj_desc->method.aml_start);
71 [ + - ]: 884 : if (!op) {
72 : : return_ACPI_STATUS(AE_NO_MEMORY);
73 : : }
74 : :
75 : 884 : acpi_ps_set_name(op, node->name.integer);
76 : 884 : op->common.node = node;
77 : :
78 : : /* Create and initialize a new walk state */
79 : :
80 : 884 : walk_state =
81 : 884 : acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
82 [ - + ]: 884 : if (!walk_state) {
83 : 0 : acpi_ps_free_op(op);
84 : 0 : return_ACPI_STATUS(AE_NO_MEMORY);
85 : : }
86 : :
87 : 884 : status = acpi_ds_init_aml_walk(walk_state, op, node,
88 : : obj_desc->method.aml_start,
89 : : obj_desc->method.aml_length, NULL, 0);
90 [ - + ]: 884 : if (ACPI_FAILURE(status)) {
91 : 0 : acpi_ds_delete_walk_state(walk_state);
92 : 0 : acpi_ps_free_op(op);
93 : 0 : return_ACPI_STATUS(status);
94 : : }
95 : :
96 : 884 : walk_state->descending_callback = acpi_ds_detect_named_opcodes;
97 : :
98 : : /* Parse the method, scan for creation of named objects */
99 : :
100 : 884 : status = acpi_ps_parse_aml(walk_state);
101 : :
102 : 884 : acpi_ps_delete_parse_tree(op);
103 : 884 : return_ACPI_STATUS(status);
104 : : }
105 : :
106 : : /*******************************************************************************
107 : : *
108 : : * FUNCTION: acpi_ds_detect_named_opcodes
109 : : *
110 : : * PARAMETERS: walk_state - Current state of the parse tree walk
111 : : * out_op - Unused, required for parser interface
112 : : *
113 : : * RETURN: Status
114 : : *
115 : : * DESCRIPTION: Descending callback used during the loading of ACPI tables.
116 : : * Currently used to detect methods that must be marked serialized
117 : : * in order to avoid problems with the creation of named objects.
118 : : *
119 : : ******************************************************************************/
120 : :
121 : : static acpi_status
122 : 7163 : acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
123 : : union acpi_parse_object **out_op)
124 : : {
125 : :
126 : 7163 : ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
127 : :
128 : : /* We are only interested in opcodes that create a new name */
129 : :
130 : 7163 : if (!
131 [ + + ]: 7163 : (walk_state->op_info->
132 : : flags & (AML_NAMED | AML_CREATE | AML_FIELD))) {
133 : : return (AE_OK);
134 : : }
135 : :
136 : : /*
137 : : * At this point, we know we have a Named object opcode.
138 : : * Mark the method as serialized. Later code will create a mutex for
139 : : * this method to enforce serialization.
140 : : *
141 : : * Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
142 : : * Sync Level mechanism for this method, even though it is now serialized.
143 : : * Otherwise, there can be conflicts with existing ASL code that actually
144 : : * uses sync levels.
145 : : */
146 : 52 : walk_state->method_desc->method.sync_level = 0;
147 : 52 : walk_state->method_desc->method.info_flags |=
148 : : (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
149 : :
150 : : ACPI_DEBUG_PRINT((ACPI_DB_INFO,
151 : : "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
152 : : walk_state->method_node->name.ascii,
153 : : walk_state->method_node, walk_state->op_info->name,
154 : 52 : walk_state->opcode));
155 : :
156 : : /* Abort the parse, no need to examine this method any further */
157 : :
158 : 52 : return (AE_CTRL_TERMINATE);
159 : : }
160 : :
161 : : /*******************************************************************************
162 : : *
163 : : * FUNCTION: acpi_ds_method_error
164 : : *
165 : : * PARAMETERS: status - Execution status
166 : : * walk_state - Current state
167 : : *
168 : : * RETURN: Status
169 : : *
170 : : * DESCRIPTION: Called on method error. Invoke the global exception handler if
171 : : * present, dump the method data if the debugger is configured
172 : : *
173 : : * Note: Allows the exception handler to change the status code
174 : : *
175 : : ******************************************************************************/
176 : :
177 : : acpi_status
178 : 15691 : acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
179 : : {
180 : 15691 : u32 aml_offset;
181 : 15691 : acpi_name name = 0;
182 : :
183 : 15691 : ACPI_FUNCTION_ENTRY();
184 : :
185 : : /* Ignore AE_OK and control exception codes */
186 : :
187 [ + - - + ]: 15691 : if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
188 : : return (status);
189 : : }
190 : :
191 : : /* Invoke the global exception handler */
192 : :
193 [ # # ]: 0 : if (acpi_gbl_exception_handler) {
194 : :
195 : : /* Exit the interpreter, allow handler to execute methods */
196 : :
197 : 0 : acpi_ex_exit_interpreter();
198 : :
199 : : /*
200 : : * Handler can map the exception code to anything it wants, including
201 : : * AE_OK, in which case the executing method will not be aborted.
202 : : */
203 : 0 : aml_offset = (u32)ACPI_PTR_DIFF(walk_state->aml,
204 : : walk_state->parser_state.
205 : : aml_start);
206 : :
207 [ # # ]: 0 : if (walk_state->method_node) {
208 : 0 : name = walk_state->method_node->name.integer;
209 [ # # ]: 0 : } else if (walk_state->deferred_node) {
210 : 0 : name = walk_state->deferred_node->name.integer;
211 : : }
212 : :
213 : 0 : status = acpi_gbl_exception_handler(status, name,
214 : 0 : walk_state->opcode,
215 : : aml_offset, NULL);
216 : 0 : acpi_ex_enter_interpreter();
217 : : }
218 : :
219 : 0 : acpi_ds_clear_implicit_return(walk_state);
220 : :
221 [ # # ]: 0 : if (ACPI_FAILURE(status)) {
222 : 0 : acpi_ds_dump_method_stack(status, walk_state, walk_state->op);
223 : :
224 : : /* Display method locals/args if debugger is present */
225 : :
226 : : #ifdef ACPI_DEBUGGER
227 : : acpi_db_dump_method_info(status, walk_state);
228 : : #endif
229 : : }
230 : :
231 : : return (status);
232 : : }
233 : :
234 : : /*******************************************************************************
235 : : *
236 : : * FUNCTION: acpi_ds_create_method_mutex
237 : : *
238 : : * PARAMETERS: obj_desc - The method object
239 : : *
240 : : * RETURN: Status
241 : : *
242 : : * DESCRIPTION: Create a mutex object for a serialized control method
243 : : *
244 : : ******************************************************************************/
245 : :
246 : : static acpi_status
247 : 65 : acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
248 : : {
249 : 65 : union acpi_operand_object *mutex_desc;
250 : 65 : acpi_status status;
251 : :
252 : 65 : ACPI_FUNCTION_TRACE(ds_create_method_mutex);
253 : :
254 : : /* Create the new mutex object */
255 : :
256 : 65 : mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
257 [ + - ]: 65 : if (!mutex_desc) {
258 : : return_ACPI_STATUS(AE_NO_MEMORY);
259 : : }
260 : :
261 : : /* Create the actual OS Mutex */
262 : :
263 : 65 : status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
264 [ - + ]: 65 : if (ACPI_FAILURE(status)) {
265 : 0 : acpi_ut_delete_object_desc(mutex_desc);
266 : 0 : return_ACPI_STATUS(status);
267 : : }
268 : :
269 : 65 : mutex_desc->mutex.sync_level = method_desc->method.sync_level;
270 : 65 : method_desc->method.mutex = mutex_desc;
271 : 65 : return_ACPI_STATUS(AE_OK);
272 : : }
273 : :
274 : : /*******************************************************************************
275 : : *
276 : : * FUNCTION: acpi_ds_begin_method_execution
277 : : *
278 : : * PARAMETERS: method_node - Node of the method
279 : : * obj_desc - The method object
280 : : * walk_state - current state, NULL if not yet executing
281 : : * a method.
282 : : *
283 : : * RETURN: Status
284 : : *
285 : : * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
286 : : * increments the thread count, and waits at the method semaphore
287 : : * for clearance to execute.
288 : : *
289 : : ******************************************************************************/
290 : :
291 : : acpi_status
292 : 1313 : acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
293 : : union acpi_operand_object *obj_desc,
294 : : struct acpi_walk_state *walk_state)
295 : : {
296 : 1313 : acpi_status status = AE_OK;
297 : :
298 : 1313 : ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
299 : :
300 [ + - ]: 1313 : if (!method_node) {
301 : : return_ACPI_STATUS(AE_NULL_ENTRY);
302 : : }
303 : :
304 : 1313 : acpi_ex_start_trace_method(method_node, obj_desc, walk_state);
305 : :
306 : : /* Prevent wraparound of thread count */
307 : :
308 [ - + ]: 1313 : if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
309 : 0 : ACPI_ERROR((AE_INFO,
310 : : "Method reached maximum reentrancy limit (255)"));
311 : 0 : return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
312 : : }
313 : :
314 : : /*
315 : : * If this method is serialized, we need to acquire the method mutex.
316 : : */
317 [ + + ]: 1313 : if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
318 : : /*
319 : : * Create a mutex for the method if it is defined to be Serialized
320 : : * and a mutex has not already been created. We defer the mutex creation
321 : : * until a method is actually executed, to minimize the object count
322 : : */
323 [ + + ]: 195 : if (!obj_desc->method.mutex) {
324 : 65 : status = acpi_ds_create_method_mutex(obj_desc);
325 [ + - ]: 65 : if (ACPI_FAILURE(status)) {
326 : : return_ACPI_STATUS(status);
327 : : }
328 : : }
329 : :
330 : : /*
331 : : * The current_sync_level (per-thread) must be less than or equal to
332 : : * the sync level of the method. This mechanism provides some
333 : : * deadlock prevention.
334 : : *
335 : : * If the method was auto-serialized, we just ignore the sync level
336 : : * mechanism, because auto-serialization of methods can interfere
337 : : * with ASL code that actually uses sync levels.
338 : : *
339 : : * Top-level method invocation has no walk state at this point
340 : : */
341 [ + + ]: 195 : if (walk_state &&
342 [ + - ]: 143 : (!(obj_desc->method.
343 : : info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
344 : 143 : && (walk_state->thread->current_sync_level >
345 [ - + ]: 143 : obj_desc->method.mutex->mutex.sync_level)) {
346 : 0 : ACPI_ERROR((AE_INFO,
347 : : "Cannot acquire Mutex for method [%4.4s]"
348 : : ", current SyncLevel is too large (%u)",
349 : : acpi_ut_get_node_name(method_node),
350 : : walk_state->thread->current_sync_level));
351 : :
352 : 0 : return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
353 : : }
354 : :
355 : : /*
356 : : * Obtain the method mutex if necessary. Do not acquire mutex for a
357 : : * recursive call.
358 : : */
359 [ + + ]: 195 : if (!walk_state ||
360 [ - + ]: 143 : !obj_desc->method.mutex->mutex.thread_id ||
361 [ # # ]: 0 : (walk_state->thread->thread_id !=
362 : : obj_desc->method.mutex->mutex.thread_id)) {
363 : : /*
364 : : * Acquire the method mutex. This releases the interpreter if we
365 : : * block (and reacquires it before it returns)
366 : : */
367 : 195 : status =
368 : 195 : acpi_ex_system_wait_mutex(obj_desc->method.mutex->
369 : : mutex.os_mutex,
370 : : ACPI_WAIT_FOREVER);
371 [ + - ]: 195 : if (ACPI_FAILURE(status)) {
372 : : return_ACPI_STATUS(status);
373 : : }
374 : :
375 : : /* Update the mutex and walk info and save the original sync_level */
376 : :
377 [ + + ]: 195 : if (walk_state) {
378 : 143 : obj_desc->method.mutex->mutex.
379 : 143 : original_sync_level =
380 : 143 : walk_state->thread->current_sync_level;
381 : :
382 : 143 : obj_desc->method.mutex->mutex.thread_id =
383 : 143 : walk_state->thread->thread_id;
384 : :
385 : : /*
386 : : * Update the current sync_level only if this is not an auto-
387 : : * serialized method. In the auto case, we have to ignore
388 : : * the sync level for the method mutex (created for the
389 : : * auto-serialization) because we have no idea of what the
390 : : * sync level should be. Therefore, just ignore it.
391 : : */
392 [ + - ]: 143 : if (!(obj_desc->method.info_flags &
393 : : ACPI_METHOD_IGNORE_SYNC_LEVEL)) {
394 : 143 : walk_state->thread->current_sync_level =
395 : 143 : obj_desc->method.sync_level;
396 : : }
397 : : } else {
398 : 52 : obj_desc->method.mutex->mutex.
399 : 52 : original_sync_level =
400 : 52 : obj_desc->method.mutex->mutex.sync_level;
401 : :
402 : 52 : obj_desc->method.mutex->mutex.thread_id =
403 : : acpi_os_get_thread_id();
404 : : }
405 : : }
406 : :
407 : : /* Always increase acquisition depth */
408 : :
409 : 195 : obj_desc->method.mutex->mutex.acquisition_depth++;
410 : : }
411 : :
412 : : /*
413 : : * Allocate an Owner ID for this method, only if this is the first thread
414 : : * to begin concurrent execution. We only need one owner_id, even if the
415 : : * method is invoked recursively.
416 : : */
417 [ + - ]: 1313 : if (!obj_desc->method.owner_id) {
418 : 1313 : status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
419 [ - + ]: 1313 : if (ACPI_FAILURE(status)) {
420 : 0 : goto cleanup;
421 : : }
422 : : }
423 : :
424 : : /*
425 : : * Increment the method parse tree thread count since it has been
426 : : * reentered one more time (even if it is the same thread)
427 : : */
428 : 1313 : obj_desc->method.thread_count++;
429 : 1313 : acpi_method_count++;
430 : 1313 : return_ACPI_STATUS(status);
431 : :
432 : : cleanup:
433 : : /* On error, must release the method mutex (if present) */
434 : :
435 [ # # ]: 0 : if (obj_desc->method.mutex) {
436 : 0 : acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
437 : : }
438 : : return_ACPI_STATUS(status);
439 : : }
440 : :
441 : : /*******************************************************************************
442 : : *
443 : : * FUNCTION: acpi_ds_call_control_method
444 : : *
445 : : * PARAMETERS: thread - Info for this thread
446 : : * this_walk_state - Current walk state
447 : : * op - Current Op to be walked
448 : : *
449 : : * RETURN: Status
450 : : *
451 : : * DESCRIPTION: Transfer execution to a called control method
452 : : *
453 : : ******************************************************************************/
454 : :
455 : : acpi_status
456 : 364 : acpi_ds_call_control_method(struct acpi_thread_state *thread,
457 : : struct acpi_walk_state *this_walk_state,
458 : : union acpi_parse_object *op)
459 : : {
460 : 364 : acpi_status status;
461 : 364 : struct acpi_namespace_node *method_node;
462 : 364 : struct acpi_walk_state *next_walk_state = NULL;
463 : 364 : union acpi_operand_object *obj_desc;
464 : 364 : struct acpi_evaluate_info *info;
465 : 364 : u32 i;
466 : :
467 : 364 : ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
468 : :
469 : : ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
470 : : "Calling method %p, currentstate=%p\n",
471 : 364 : this_walk_state->prev_op, this_walk_state));
472 : :
473 : : /*
474 : : * Get the namespace entry for the control method we are about to call
475 : : */
476 : 364 : method_node = this_walk_state->method_call_node;
477 [ + - ]: 364 : if (!method_node) {
478 : : return_ACPI_STATUS(AE_NULL_ENTRY);
479 : : }
480 : :
481 : 364 : obj_desc = acpi_ns_get_attached_object(method_node);
482 [ + - ]: 364 : if (!obj_desc) {
483 : : return_ACPI_STATUS(AE_NULL_OBJECT);
484 : : }
485 : :
486 : : /* Init for new method, possibly wait on method mutex */
487 : :
488 : 364 : status =
489 : 364 : acpi_ds_begin_method_execution(method_node, obj_desc,
490 : : this_walk_state);
491 [ + - ]: 364 : if (ACPI_FAILURE(status)) {
492 : : return_ACPI_STATUS(status);
493 : : }
494 : :
495 : : /* Begin method parse/execution. Create a new walk state */
496 : :
497 : 364 : next_walk_state =
498 : 364 : acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, obj_desc,
499 : : thread);
500 [ - + ]: 364 : if (!next_walk_state) {
501 : 0 : status = AE_NO_MEMORY;
502 : 0 : goto cleanup;
503 : : }
504 : :
505 : : /*
506 : : * The resolved arguments were put on the previous walk state's operand
507 : : * stack. Operands on the previous walk state stack always
508 : : * start at index 0. Also, null terminate the list of arguments
509 : : */
510 : 364 : this_walk_state->operands[this_walk_state->num_operands] = NULL;
511 : :
512 : : /*
513 : : * Allocate and initialize the evaluation information block
514 : : * TBD: this is somewhat inefficient, should change interface to
515 : : * ds_init_aml_walk. For now, keeps this struct off the CPU stack
516 : : */
517 : 364 : info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
518 [ - + ]: 364 : if (!info) {
519 : 0 : status = AE_NO_MEMORY;
520 : 0 : goto cleanup;
521 : : }
522 : :
523 : 364 : info->parameters = &this_walk_state->operands[0];
524 : :
525 : 364 : status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
526 : : obj_desc->method.aml_start,
527 : : obj_desc->method.aml_length, info,
528 : : ACPI_IMODE_EXECUTE);
529 : :
530 : 364 : ACPI_FREE(info);
531 [ - + ]: 364 : if (ACPI_FAILURE(status)) {
532 : 0 : goto cleanup;
533 : : }
534 : :
535 : 364 : next_walk_state->method_nesting_depth =
536 : 364 : this_walk_state->method_nesting_depth + 1;
537 : :
538 : : /*
539 : : * Delete the operands on the previous walkstate operand stack
540 : : * (they were copied to new objects)
541 : : */
542 [ + + ]: 728 : for (i = 0; i < obj_desc->method.param_count; i++) {
543 : 364 : acpi_ut_remove_reference(this_walk_state->operands[i]);
544 : 364 : this_walk_state->operands[i] = NULL;
545 : : }
546 : :
547 : : /* Clear the operand stack */
548 : :
549 : 364 : this_walk_state->num_operands = 0;
550 : :
551 : : ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
552 : : "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
553 : 364 : method_node->name.ascii, next_walk_state));
554 : :
555 : 728 : this_walk_state->method_pathname =
556 : 364 : acpi_ns_get_normalized_pathname(method_node, TRUE);
557 : 364 : this_walk_state->method_is_nested = TRUE;
558 : :
559 : : /* Optional object evaluation log */
560 : :
561 : : ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
562 : : "%-26s: %*s%s\n", " Nested method call",
563 : : next_walk_state->method_nesting_depth * 3, " ",
564 : 364 : &this_walk_state->method_pathname[1]));
565 : :
566 : : /* Invoke an internal method if necessary */
567 : :
568 [ - + ]: 364 : if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
569 : 0 : status =
570 : 0 : obj_desc->method.dispatch.implementation(next_walk_state);
571 [ # # ]: 0 : if (status == AE_OK) {
572 : 0 : status = AE_CTRL_TERMINATE;
573 : : }
574 : : }
575 : :
576 : : return_ACPI_STATUS(status);
577 : :
578 : 0 : cleanup:
579 : :
580 : : /* On error, we must terminate the method properly */
581 : :
582 : 0 : acpi_ds_terminate_control_method(obj_desc, next_walk_state);
583 : 0 : acpi_ds_delete_walk_state(next_walk_state);
584 : :
585 : 0 : return_ACPI_STATUS(status);
586 : : }
587 : :
588 : : /*******************************************************************************
589 : : *
590 : : * FUNCTION: acpi_ds_restart_control_method
591 : : *
592 : : * PARAMETERS: walk_state - State for preempted method (caller)
593 : : * return_desc - Return value from the called method
594 : : *
595 : : * RETURN: Status
596 : : *
597 : : * DESCRIPTION: Restart a method that was preempted by another (nested) method
598 : : * invocation. Handle the return value (if any) from the callee.
599 : : *
600 : : ******************************************************************************/
601 : :
602 : : acpi_status
603 : 364 : acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
604 : : union acpi_operand_object *return_desc)
605 : : {
606 : 364 : acpi_status status;
607 : 364 : int same_as_implicit_return;
608 : :
609 : 364 : ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
610 : :
611 : : ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
612 : : "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
613 : : acpi_ut_get_node_name(walk_state->method_node),
614 : 364 : walk_state->method_call_op, return_desc));
615 : :
616 : : ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
617 : : " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
618 : : walk_state->return_used,
619 : 364 : walk_state->results, walk_state));
620 : :
621 : : /* Did the called method return a value? */
622 : :
623 [ + - ]: 364 : if (return_desc) {
624 : :
625 : : /* Is the implicit return object the same as the return desc? */
626 : :
627 : 364 : same_as_implicit_return =
628 : 364 : (walk_state->implicit_return_obj == return_desc);
629 : :
630 : : /* Are we actually going to use the return value? */
631 : :
632 [ + - ]: 364 : if (walk_state->return_used) {
633 : :
634 : : /* Save the return value from the previous method */
635 : :
636 : 364 : status = acpi_ds_result_push(return_desc, walk_state);
637 [ - + ]: 364 : if (ACPI_FAILURE(status)) {
638 : 0 : acpi_ut_remove_reference(return_desc);
639 : 0 : return_ACPI_STATUS(status);
640 : : }
641 : :
642 : : /*
643 : : * Save as THIS method's return value in case it is returned
644 : : * immediately to yet another method
645 : : */
646 : 364 : walk_state->return_desc = return_desc;
647 : : }
648 : :
649 : : /*
650 : : * The following code is the optional support for the so-called
651 : : * "implicit return". Some AML code assumes that the last value of the
652 : : * method is "implicitly" returned to the caller, in the absence of an
653 : : * explicit return value.
654 : : *
655 : : * Just save the last result of the method as the return value.
656 : : *
657 : : * NOTE: this is optional because the ASL language does not actually
658 : : * support this behavior.
659 : : */
660 [ # # ]: 0 : else if (!acpi_ds_do_implicit_return
661 : : (return_desc, walk_state, FALSE)
662 [ # # ]: 0 : || same_as_implicit_return) {
663 : : /*
664 : : * Delete the return value if it will not be used by the
665 : : * calling method or remove one reference if the explicit return
666 : : * is the same as the implicit return value.
667 : : */
668 : 0 : acpi_ut_remove_reference(return_desc);
669 : : }
670 : : }
671 : :
672 : : return_ACPI_STATUS(AE_OK);
673 : : }
674 : :
675 : : /*******************************************************************************
676 : : *
677 : : * FUNCTION: acpi_ds_terminate_control_method
678 : : *
679 : : * PARAMETERS: method_desc - Method object
680 : : * walk_state - State associated with the method
681 : : *
682 : : * RETURN: None
683 : : *
684 : : * DESCRIPTION: Terminate a control method. Delete everything that the method
685 : : * created, delete all locals and arguments, and delete the parse
686 : : * tree if requested.
687 : : *
688 : : * MUTEX: Interpreter is locked
689 : : *
690 : : ******************************************************************************/
691 : :
692 : : void
693 : 1365 : acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
694 : : struct acpi_walk_state *walk_state)
695 : : {
696 : :
697 : 1365 : ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
698 : :
699 : : /* method_desc is required, walk_state is optional */
700 : :
701 [ + + ]: 1365 : if (!method_desc) {
702 : : return_VOID;
703 : : }
704 : :
705 [ + - ]: 1313 : if (walk_state) {
706 : :
707 : : /* Delete all arguments and locals */
708 : :
709 : 1313 : acpi_ds_method_data_delete_all(walk_state);
710 : :
711 : : /*
712 : : * Delete any namespace objects created anywhere within the
713 : : * namespace by the execution of this method. Unless:
714 : : * 1) This method is a module-level executable code method, in which
715 : : * case we want make the objects permanent.
716 : : * 2) There are other threads executing the method, in which case we
717 : : * will wait until the last thread has completed.
718 : : */
719 [ + - ]: 1313 : if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
720 [ + - ]: 1313 : && (method_desc->method.thread_count == 1)) {
721 : :
722 : : /* Delete any direct children of (created by) this method */
723 : :
724 : 1313 : (void)acpi_ex_exit_interpreter();
725 : 1313 : acpi_ns_delete_namespace_subtree(walk_state->
726 : : method_node);
727 : 1313 : (void)acpi_ex_enter_interpreter();
728 : :
729 : : /*
730 : : * Delete any objects that were created by this method
731 : : * elsewhere in the namespace (if any were created).
732 : : * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
733 : : * deletion such that we don't have to perform an entire
734 : : * namespace walk for every control method execution.
735 : : */
736 [ - + ]: 1313 : if (method_desc->method.
737 : : info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
738 : 0 : (void)acpi_ex_exit_interpreter();
739 : 0 : acpi_ns_delete_namespace_by_owner(method_desc->
740 : 0 : method.
741 : : owner_id);
742 : 0 : (void)acpi_ex_enter_interpreter();
743 : 0 : method_desc->method.info_flags &=
744 : : ~ACPI_METHOD_MODIFIED_NAMESPACE;
745 : : }
746 : : }
747 : :
748 : : /*
749 : : * If method is serialized, release the mutex and restore the
750 : : * current sync level for this thread
751 : : */
752 [ + + ]: 1313 : if (method_desc->method.mutex) {
753 : :
754 : : /* Acquisition Depth handles recursive calls */
755 : :
756 : 195 : method_desc->method.mutex->mutex.acquisition_depth--;
757 [ + - ]: 195 : if (!method_desc->method.mutex->mutex.acquisition_depth) {
758 : 195 : walk_state->thread->current_sync_level =
759 : 195 : method_desc->method.mutex->mutex.
760 : : original_sync_level;
761 : :
762 : 195 : acpi_os_release_mutex(method_desc->method.
763 : : mutex->mutex.os_mutex);
764 : 195 : method_desc->method.mutex->mutex.thread_id = 0;
765 : : }
766 : : }
767 : : }
768 : :
769 : : /* Decrement the thread count on the method */
770 : :
771 [ + - ]: 1313 : if (method_desc->method.thread_count) {
772 : 1313 : method_desc->method.thread_count--;
773 : : } else {
774 : 0 : ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
775 : : }
776 : :
777 : : /* Are there any other threads currently executing this method? */
778 : :
779 [ + - ]: 1313 : if (method_desc->method.thread_count) {
780 : : /*
781 : : * Additional threads. Do not release the owner_id in this case,
782 : : * we immediately reuse it for the next thread executing this method
783 : : */
784 : : ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
785 : : "*** Completed execution of one thread, %u threads remaining\n",
786 : : method_desc->method.thread_count));
787 : : } else {
788 : : /* This is the only executing thread for this method */
789 : :
790 : : /*
791 : : * Support to dynamically change a method from not_serialized to
792 : : * Serialized if it appears that the method is incorrectly written and
793 : : * does not support multiple thread execution. The best example of this
794 : : * is if such a method creates namespace objects and blocks. A second
795 : : * thread will fail with an AE_ALREADY_EXISTS exception.
796 : : *
797 : : * This code is here because we must wait until the last thread exits
798 : : * before marking the method as serialized.
799 : : */
800 [ - + ]: 1313 : if (method_desc->method.
801 : : info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
802 [ # # ]: 0 : if (walk_state) {
803 : 0 : ACPI_INFO(("Marking method %4.4s as Serialized "
804 : : "because of AE_ALREADY_EXISTS error",
805 : : walk_state->method_node->name.
806 : : ascii));
807 : : }
808 : :
809 : : /*
810 : : * Method tried to create an object twice and was marked as
811 : : * "pending serialized". The probable cause is that the method
812 : : * cannot handle reentrancy.
813 : : *
814 : : * The method was created as not_serialized, but it tried to create
815 : : * a named object and then blocked, causing the second thread
816 : : * entrance to begin and then fail. Workaround this problem by
817 : : * marking the method permanently as Serialized when the last
818 : : * thread exits here.
819 : : */
820 : 0 : method_desc->method.info_flags &=
821 : : ~ACPI_METHOD_SERIALIZED_PENDING;
822 : :
823 : 0 : method_desc->method.info_flags |=
824 : : (ACPI_METHOD_SERIALIZED |
825 : : ACPI_METHOD_IGNORE_SYNC_LEVEL);
826 : 0 : method_desc->method.sync_level = 0;
827 : : }
828 : :
829 : : /* No more threads, we can free the owner_id */
830 : :
831 : 1313 : if (!
832 [ + - ]: 1313 : (method_desc->method.
833 : : info_flags & ACPI_METHOD_MODULE_LEVEL)) {
834 : 1313 : acpi_ut_release_owner_id(&method_desc->method.owner_id);
835 : : }
836 : : }
837 : :
838 : 1313 : acpi_ex_stop_trace_method((struct acpi_namespace_node *)method_desc->
839 : 1313 : method.node, method_desc, walk_state);
840 : :
841 : 1313 : return_VOID;
842 : : }
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