1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3 *
4 * Module Name: psloop - Main AML parse loop
5 *
6 * Copyright (C) 2000 - 2018, Intel Corp.
7 *
8 *****************************************************************************/
9
10 /*
11 * Parse the AML and build an operation tree as most interpreters, (such as
12 * Perl) do. Parsing is done by hand rather than with a YACC generated parser
13 * to tightly constrain stack and dynamic memory usage. Parsing is kept
14 * flexible and the code fairly compact by parsing based on a list of AML
15 * opcode templates in aml_op_info[].
16 */
17
18 #include <acpi/acpi.h>
19 #include "accommon.h"
20 #include "acinterp.h"
21 #include "acparser.h"
22 #include "acdispat.h"
23 #include "amlcode.h"
24 #include "acconvert.h"
25 #include "acnamesp.h"
26
27 #define _COMPONENT ACPI_PARSER
28 ACPI_MODULE_NAME("psloop")
29
30 /* Local prototypes */
31 static acpi_status
32 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
33 u8 * aml_op_start, union acpi_parse_object *op);
34
35 static void
36 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
37 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id);
38
39 /*******************************************************************************
40 *
41 * FUNCTION: acpi_ps_get_arguments
42 *
43 * PARAMETERS: walk_state - Current state
44 * aml_op_start - Op start in AML
45 * op - Current Op
46 *
47 * RETURN: Status
48 *
49 * DESCRIPTION: Get arguments for passed Op.
50 *
51 ******************************************************************************/
52
53 static acpi_status
acpi_ps_get_arguments(struct acpi_walk_state * walk_state,u8 * aml_op_start,union acpi_parse_object * op)54 acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
55 u8 * aml_op_start, union acpi_parse_object *op)
56 {
57 acpi_status status = AE_OK;
58 union acpi_parse_object *arg = NULL;
59 const struct acpi_opcode_info *op_info;
60
61 ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);
62
63 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
64 "Get arguments for opcode [%s]\n",
65 op->common.aml_op_name));
66
67 switch (op->common.aml_opcode) {
68 case AML_BYTE_OP: /* AML_BYTEDATA_ARG */
69 case AML_WORD_OP: /* AML_WORDDATA_ARG */
70 case AML_DWORD_OP: /* AML_DWORDATA_ARG */
71 case AML_QWORD_OP: /* AML_QWORDATA_ARG */
72 case AML_STRING_OP: /* AML_ASCIICHARLIST_ARG */
73
74 /* Fill in constant or string argument directly */
75
76 acpi_ps_get_next_simple_arg(&(walk_state->parser_state),
77 GET_CURRENT_ARG_TYPE(walk_state->
78 arg_types),
79 op);
80 break;
81
82 case AML_INT_NAMEPATH_OP: /* AML_NAMESTRING_ARG */
83
84 status = acpi_ps_get_next_namepath(walk_state,
85 &(walk_state->parser_state),
86 op,
87 ACPI_POSSIBLE_METHOD_CALL);
88 if (ACPI_FAILURE(status)) {
89 return_ACPI_STATUS(status);
90 }
91
92 walk_state->arg_types = 0;
93 break;
94
95 default:
96 /*
97 * Op is not a constant or string, append each argument to the Op
98 */
99 while (GET_CURRENT_ARG_TYPE(walk_state->arg_types) &&
100 !walk_state->arg_count) {
101 walk_state->aml = walk_state->parser_state.aml;
102
103 switch (op->common.aml_opcode) {
104 case AML_METHOD_OP:
105 case AML_BUFFER_OP:
106 case AML_PACKAGE_OP:
107 case AML_VARIABLE_PACKAGE_OP:
108 case AML_WHILE_OP:
109
110 break;
111
112 default:
113
114 ASL_CV_CAPTURE_COMMENTS(walk_state);
115 break;
116 }
117
118 status =
119 acpi_ps_get_next_arg(walk_state,
120 &(walk_state->parser_state),
121 GET_CURRENT_ARG_TYPE
122 (walk_state->arg_types), &arg);
123 if (ACPI_FAILURE(status)) {
124 return_ACPI_STATUS(status);
125 }
126
127 if (arg) {
128 acpi_ps_append_arg(op, arg);
129 }
130
131 INCREMENT_ARG_LIST(walk_state->arg_types);
132 }
133
134 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
135 "Final argument count: %8.8X pass %u\n",
136 walk_state->arg_count,
137 walk_state->pass_number));
138
139 /*
140 * This case handles the legacy option that groups all module-level
141 * code blocks together and defers execution until all of the tables
142 * are loaded. Execute all of these blocks at this time.
143 * Execute any module-level code that was detected during the table
144 * load phase.
145 *
146 * Note: this option is deprecated and will be eliminated in the
147 * future. Use of this option can cause problems with AML code that
148 * depends upon in-order immediate execution of module-level code.
149 */
150 if (acpi_gbl_group_module_level_code &&
151 (walk_state->pass_number <= ACPI_IMODE_LOAD_PASS2) &&
152 ((walk_state->parse_flags & ACPI_PARSE_DISASSEMBLE) == 0)) {
153 /*
154 * We want to skip If/Else/While constructs during Pass1 because we
155 * want to actually conditionally execute the code during Pass2.
156 *
157 * Except for disassembly, where we always want to walk the
158 * If/Else/While packages
159 */
160 switch (op->common.aml_opcode) {
161 case AML_IF_OP:
162 case AML_ELSE_OP:
163 case AML_WHILE_OP:
164 /*
165 * Currently supported module-level opcodes are:
166 * IF/ELSE/WHILE. These appear to be the most common,
167 * and easiest to support since they open an AML
168 * package.
169 */
170 if (walk_state->pass_number ==
171 ACPI_IMODE_LOAD_PASS1) {
172 acpi_ps_link_module_code(op->common.
173 parent,
174 aml_op_start,
175 (u32)
176 (walk_state->
177 parser_state.
178 pkg_end -
179 aml_op_start),
180 walk_state->
181 owner_id);
182 }
183
184 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
185 "Pass1: Skipping an If/Else/While body\n"));
186
187 /* Skip body of if/else/while in pass 1 */
188
189 walk_state->parser_state.aml =
190 walk_state->parser_state.pkg_end;
191 walk_state->arg_count = 0;
192 break;
193
194 default:
195 /*
196 * Check for an unsupported executable opcode at module
197 * level. We must be in PASS1, the parent must be a SCOPE,
198 * The opcode class must be EXECUTE, and the opcode must
199 * not be an argument to another opcode.
200 */
201 if ((walk_state->pass_number ==
202 ACPI_IMODE_LOAD_PASS1)
203 && (op->common.parent->common.aml_opcode ==
204 AML_SCOPE_OP)) {
205 op_info =
206 acpi_ps_get_opcode_info(op->common.
207 aml_opcode);
208 if ((op_info->class ==
209 AML_CLASS_EXECUTE) && (!arg)) {
210 ACPI_WARNING((AE_INFO,
211 "Unsupported module-level executable opcode "
212 "0x%.2X at table offset 0x%.4X",
213 op->common.
214 aml_opcode,
215 (u32)
216 (ACPI_PTR_DIFF
217 (aml_op_start,
218 walk_state->
219 parser_state.
220 aml_start) +
221 sizeof(struct
222 acpi_table_header))));
223 }
224 }
225 break;
226 }
227 }
228
229 /* Special processing for certain opcodes */
230
231 switch (op->common.aml_opcode) {
232 case AML_METHOD_OP:
233 /*
234 * Skip parsing of control method because we don't have enough
235 * info in the first pass to parse it correctly.
236 *
237 * Save the length and address of the body
238 */
239 op->named.data = walk_state->parser_state.aml;
240 op->named.length = (u32)
241 (walk_state->parser_state.pkg_end -
242 walk_state->parser_state.aml);
243
244 /* Skip body of method */
245
246 walk_state->parser_state.aml =
247 walk_state->parser_state.pkg_end;
248 walk_state->arg_count = 0;
249 break;
250
251 case AML_BUFFER_OP:
252 case AML_PACKAGE_OP:
253 case AML_VARIABLE_PACKAGE_OP:
254
255 if ((op->common.parent) &&
256 (op->common.parent->common.aml_opcode ==
257 AML_NAME_OP)
258 && (walk_state->pass_number <=
259 ACPI_IMODE_LOAD_PASS2)) {
260 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
261 "Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
262 walk_state->pass_number,
263 aml_op_start));
264
265 /*
266 * Skip parsing of Buffers and Packages because we don't have
267 * enough info in the first pass to parse them correctly.
268 */
269 op->named.data = aml_op_start;
270 op->named.length = (u32)
271 (walk_state->parser_state.pkg_end -
272 aml_op_start);
273
274 /* Skip body */
275
276 walk_state->parser_state.aml =
277 walk_state->parser_state.pkg_end;
278 walk_state->arg_count = 0;
279 }
280 break;
281
282 case AML_WHILE_OP:
283
284 if (walk_state->control_state) {
285 walk_state->control_state->control.package_end =
286 walk_state->parser_state.pkg_end;
287 }
288 break;
289
290 default:
291
292 /* No action for all other opcodes */
293
294 break;
295 }
296
297 break;
298 }
299
300 return_ACPI_STATUS(AE_OK);
301 }
302
303 /*******************************************************************************
304 *
305 * FUNCTION: acpi_ps_link_module_code
306 *
307 * PARAMETERS: parent_op - Parent parser op
308 * aml_start - Pointer to the AML
309 * aml_length - Length of executable AML
310 * owner_id - owner_id of module level code
311 *
312 * RETURN: None.
313 *
314 * DESCRIPTION: Wrap the module-level code with a method object and link the
315 * object to the global list. Note, the mutex field of the method
316 * object is used to link multiple module-level code objects.
317 *
318 * NOTE: In this legacy option, each block of detected executable AML
319 * code that is outside of any control method is wrapped with a temporary
320 * control method object and placed on a global list below.
321 *
322 * This function executes the module-level code for all tables only after
323 * all of the tables have been loaded. It is a legacy option and is
324 * not compatible with other ACPI implementations. See acpi_ns_load_table.
325 *
326 * This function will be removed when the legacy option is removed.
327 *
328 ******************************************************************************/
329
330 static void
acpi_ps_link_module_code(union acpi_parse_object * parent_op,u8 * aml_start,u32 aml_length,acpi_owner_id owner_id)331 acpi_ps_link_module_code(union acpi_parse_object *parent_op,
332 u8 *aml_start, u32 aml_length, acpi_owner_id owner_id)
333 {
334 union acpi_operand_object *prev;
335 union acpi_operand_object *next;
336 union acpi_operand_object *method_obj;
337 struct acpi_namespace_node *parent_node;
338
339 ACPI_FUNCTION_TRACE(ps_link_module_code);
340
341 /* Get the tail of the list */
342
343 prev = next = acpi_gbl_module_code_list;
344 while (next) {
345 prev = next;
346 next = next->method.mutex;
347 }
348
349 /*
350 * Insert the module level code into the list. Merge it if it is
351 * adjacent to the previous element.
352 */
353 if (!prev ||
354 ((prev->method.aml_start + prev->method.aml_length) != aml_start)) {
355
356 /* Create, initialize, and link a new temporary method object */
357
358 method_obj = acpi_ut_create_internal_object(ACPI_TYPE_METHOD);
359 if (!method_obj) {
360 return_VOID;
361 }
362
363 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
364 "Create/Link new code block: %p\n",
365 method_obj));
366
367 if (parent_op->common.node) {
368 parent_node = parent_op->common.node;
369 } else {
370 parent_node = acpi_gbl_root_node;
371 }
372
373 method_obj->method.aml_start = aml_start;
374 method_obj->method.aml_length = aml_length;
375 method_obj->method.owner_id = owner_id;
376 method_obj->method.info_flags |= ACPI_METHOD_MODULE_LEVEL;
377
378 /*
379 * Save the parent node in next_object. This is cheating, but we
380 * don't want to expand the method object.
381 */
382 method_obj->method.next_object =
383 ACPI_CAST_PTR(union acpi_operand_object, parent_node);
384
385 if (!prev) {
386 acpi_gbl_module_code_list = method_obj;
387 } else {
388 prev->method.mutex = method_obj;
389 }
390 } else {
391 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
392 "Appending to existing code block: %p\n",
393 prev));
394
395 prev->method.aml_length += aml_length;
396 }
397
398 return_VOID;
399 }
400
401 /*******************************************************************************
402 *
403 * FUNCTION: acpi_ps_parse_loop
404 *
405 * PARAMETERS: walk_state - Current state
406 *
407 * RETURN: Status
408 *
409 * DESCRIPTION: Parse AML (pointed to by the current parser state) and return
410 * a tree of ops.
411 *
412 ******************************************************************************/
413
acpi_ps_parse_loop(struct acpi_walk_state * walk_state)414 acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
415 {
416 acpi_status status = AE_OK;
417 union acpi_parse_object *op = NULL; /* current op */
418 struct acpi_parse_state *parser_state;
419 u8 *aml_op_start = NULL;
420 u8 opcode_length;
421
422 ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);
423
424 if (walk_state->descending_callback == NULL) {
425 return_ACPI_STATUS(AE_BAD_PARAMETER);
426 }
427
428 parser_state = &walk_state->parser_state;
429 walk_state->arg_types = 0;
430
431 #if (!defined (ACPI_NO_METHOD_EXECUTION) && !defined (ACPI_CONSTANT_EVAL_ONLY))
432
433 if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
434
435 /* We are restarting a preempted control method */
436
437 if (acpi_ps_has_completed_scope(parser_state)) {
438 /*
439 * We must check if a predicate to an IF or WHILE statement
440 * was just completed
441 */
442 if ((parser_state->scope->parse_scope.op) &&
443 ((parser_state->scope->parse_scope.op->common.
444 aml_opcode == AML_IF_OP)
445 || (parser_state->scope->parse_scope.op->common.
446 aml_opcode == AML_WHILE_OP))
447 && (walk_state->control_state)
448 && (walk_state->control_state->common.state ==
449 ACPI_CONTROL_PREDICATE_EXECUTING)) {
450 /*
451 * A predicate was just completed, get the value of the
452 * predicate and branch based on that value
453 */
454 walk_state->op = NULL;
455 status =
456 acpi_ds_get_predicate_value(walk_state,
457 ACPI_TO_POINTER
458 (TRUE));
459 if (ACPI_FAILURE(status)
460 && ((status & AE_CODE_MASK) !=
461 AE_CODE_CONTROL)) {
462 if (status == AE_AML_NO_RETURN_VALUE) {
463 ACPI_EXCEPTION((AE_INFO, status,
464 "Invoked method did not return a value"));
465 }
466
467 ACPI_EXCEPTION((AE_INFO, status,
468 "GetPredicate Failed"));
469 return_ACPI_STATUS(status);
470 }
471
472 status =
473 acpi_ps_next_parse_state(walk_state, op,
474 status);
475 }
476
477 acpi_ps_pop_scope(parser_state, &op,
478 &walk_state->arg_types,
479 &walk_state->arg_count);
480 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
481 "Popped scope, Op=%p\n", op));
482 } else if (walk_state->prev_op) {
483
484 /* We were in the middle of an op */
485
486 op = walk_state->prev_op;
487 walk_state->arg_types = walk_state->prev_arg_types;
488 }
489 }
490 #endif
491
492 /* Iterative parsing loop, while there is more AML to process: */
493
494 while ((parser_state->aml < parser_state->aml_end) || (op)) {
495 ASL_CV_CAPTURE_COMMENTS(walk_state);
496
497 aml_op_start = parser_state->aml;
498 if (!op) {
499 status =
500 acpi_ps_create_op(walk_state, aml_op_start, &op);
501 if (ACPI_FAILURE(status)) {
502 /*
503 * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
504 * executing it as a control method. However, if we encounter
505 * an error while loading the table, we need to keep trying to
506 * load the table rather than aborting the table load. Set the
507 * status to AE_OK to proceed with the table load.
508 */
509 if ((walk_state->
510 parse_flags & ACPI_PARSE_MODULE_LEVEL)
511 && status == AE_ALREADY_EXISTS) {
512 status = AE_OK;
513 }
514 if (status == AE_CTRL_PARSE_CONTINUE) {
515 continue;
516 }
517
518 if (status == AE_CTRL_PARSE_PENDING) {
519 status = AE_OK;
520 }
521
522 if (status == AE_CTRL_TERMINATE) {
523 return_ACPI_STATUS(status);
524 }
525
526 status =
527 acpi_ps_complete_op(walk_state, &op,
528 status);
529 if (ACPI_FAILURE(status)) {
530 return_ACPI_STATUS(status);
531 }
532 if (acpi_ns_opens_scope
533 (acpi_ps_get_opcode_info
534 (walk_state->opcode)->object_type)) {
535 /*
536 * If the scope/device op fails to parse, skip the body of
537 * the scope op because the parse failure indicates that
538 * the device may not exist.
539 */
540 ACPI_ERROR((AE_INFO,
541 "Skip parsing opcode %s",
542 acpi_ps_get_opcode_name
543 (walk_state->opcode)));
544
545 /*
546 * Determine the opcode length before skipping the opcode.
547 * An opcode can be 1 byte or 2 bytes in length.
548 */
549 opcode_length = 1;
550 if ((walk_state->opcode & 0xFF00) ==
551 AML_EXTENDED_OPCODE) {
552 opcode_length = 2;
553 }
554 walk_state->parser_state.aml =
555 walk_state->aml + opcode_length;
556
557 walk_state->parser_state.aml =
558 acpi_ps_get_next_package_end
559 (&walk_state->parser_state);
560 walk_state->aml =
561 walk_state->parser_state.aml;
562 }
563
564 continue;
565 }
566
567 acpi_ex_start_trace_opcode(op, walk_state);
568 }
569
570 /*
571 * Start arg_count at zero because we don't know if there are
572 * any args yet
573 */
574 walk_state->arg_count = 0;
575
576 switch (op->common.aml_opcode) {
577 case AML_BYTE_OP:
578 case AML_WORD_OP:
579 case AML_DWORD_OP:
580 case AML_QWORD_OP:
581
582 break;
583
584 default:
585
586 ASL_CV_CAPTURE_COMMENTS(walk_state);
587 break;
588 }
589
590 /* Are there any arguments that must be processed? */
591
592 if (walk_state->arg_types) {
593
594 /* Get arguments */
595
596 status =
597 acpi_ps_get_arguments(walk_state, aml_op_start, op);
598 if (ACPI_FAILURE(status)) {
599 status =
600 acpi_ps_complete_op(walk_state, &op,
601 status);
602 if (ACPI_FAILURE(status)) {
603 return_ACPI_STATUS(status);
604 }
605 if ((walk_state->control_state) &&
606 ((walk_state->control_state->control.
607 opcode == AML_IF_OP)
608 || (walk_state->control_state->control.
609 opcode == AML_WHILE_OP))) {
610 /*
611 * If the if/while op fails to parse, we will skip parsing
612 * the body of the op.
613 */
614 parser_state->aml =
615 walk_state->control_state->control.
616 aml_predicate_start + 1;
617 parser_state->aml =
618 acpi_ps_get_next_package_end
619 (parser_state);
620 walk_state->aml = parser_state->aml;
621
622 ACPI_ERROR((AE_INFO,
623 "Skipping While/If block"));
624 if (*walk_state->aml == AML_ELSE_OP) {
625 ACPI_ERROR((AE_INFO,
626 "Skipping Else block"));
627 walk_state->parser_state.aml =
628 walk_state->aml + 1;
629 walk_state->parser_state.aml =
630 acpi_ps_get_next_package_end
631 (parser_state);
632 walk_state->aml =
633 parser_state->aml;
634 }
635 ACPI_FREE(acpi_ut_pop_generic_state
636 (&walk_state->control_state));
637 }
638 op = NULL;
639 continue;
640 }
641 }
642
643 /* Check for arguments that need to be processed */
644
645 ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
646 "Parseloop: argument count: %8.8X\n",
647 walk_state->arg_count));
648
649 if (walk_state->arg_count) {
650 /*
651 * There are arguments (complex ones), push Op and
652 * prepare for argument
653 */
654 status = acpi_ps_push_scope(parser_state, op,
655 walk_state->arg_types,
656 walk_state->arg_count);
657 if (ACPI_FAILURE(status)) {
658 status =
659 acpi_ps_complete_op(walk_state, &op,
660 status);
661 if (ACPI_FAILURE(status)) {
662 return_ACPI_STATUS(status);
663 }
664
665 continue;
666 }
667
668 op = NULL;
669 continue;
670 }
671
672 /*
673 * All arguments have been processed -- Op is complete,
674 * prepare for next
675 */
676 walk_state->op_info =
677 acpi_ps_get_opcode_info(op->common.aml_opcode);
678 if (walk_state->op_info->flags & AML_NAMED) {
679 if (op->common.aml_opcode == AML_REGION_OP ||
680 op->common.aml_opcode == AML_DATA_REGION_OP) {
681 /*
682 * Skip parsing of control method or opregion body,
683 * because we don't have enough info in the first pass
684 * to parse them correctly.
685 *
686 * Completed parsing an op_region declaration, we now
687 * know the length.
688 */
689 op->named.length =
690 (u32) (parser_state->aml - op->named.data);
691 }
692 }
693
694 if (walk_state->op_info->flags & AML_CREATE) {
695 /*
696 * Backup to beginning of create_XXXfield declaration (1 for
697 * Opcode)
698 *
699 * body_length is unknown until we parse the body
700 */
701 op->named.length =
702 (u32) (parser_state->aml - op->named.data);
703 }
704
705 if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
706 /*
707 * Backup to beginning of bank_field declaration
708 *
709 * body_length is unknown until we parse the body
710 */
711 op->named.length =
712 (u32) (parser_state->aml - op->named.data);
713 }
714
715 /* This op complete, notify the dispatcher */
716
717 if (walk_state->ascending_callback != NULL) {
718 walk_state->op = op;
719 walk_state->opcode = op->common.aml_opcode;
720
721 status = walk_state->ascending_callback(walk_state);
722 status =
723 acpi_ps_next_parse_state(walk_state, op, status);
724 if (status == AE_CTRL_PENDING) {
725 status = AE_OK;
726 } else
727 if ((walk_state->
728 parse_flags & ACPI_PARSE_MODULE_LEVEL)
729 && (ACPI_AML_EXCEPTION(status)
730 || status == AE_ALREADY_EXISTS
731 || status == AE_NOT_FOUND)) {
732 /*
733 * ACPI_PARSE_MODULE_LEVEL flag means that we
734 * are currently loading a table by executing
735 * it as a control method. However, if we
736 * encounter an error while loading the table,
737 * we need to keep trying to load the table
738 * rather than aborting the table load (setting
739 * the status to AE_OK continues the table
740 * load). If we get a failure at this point, it
741 * means that the dispatcher got an error while
742 * trying to execute the Op.
743 */
744 status = AE_OK;
745 }
746 }
747
748 status = acpi_ps_complete_op(walk_state, &op, status);
749 if (ACPI_FAILURE(status)) {
750 return_ACPI_STATUS(status);
751 }
752
753 } /* while parser_state->Aml */
754
755 status = acpi_ps_complete_final_op(walk_state, op, status);
756 return_ACPI_STATUS(status);
757 }
758