1 /******************************************************************************
2  *
3  * Module Name: psparse - Parser top level AML parse routines
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2012, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 /*
45  * Parse the AML and build an operation tree as most interpreters,
46  * like Perl, do.  Parsing is done by hand rather than with a YACC
47  * generated parser to tightly constrain stack and dynamic memory
48  * usage.  At the same time, parsing is kept flexible and the code
49  * fairly compact by parsing based on a list of AML opcode
50  * templates in aml_op_info[]
51  */
52 
53 #include <acpi/acpi.h>
54 #include "accommon.h"
55 #include "acparser.h"
56 #include "acdispat.h"
57 #include "amlcode.h"
58 #include "acinterp.h"
59 
60 #define _COMPONENT          ACPI_PARSER
61 ACPI_MODULE_NAME("psparse")
62 
63 /*******************************************************************************
64  *
65  * FUNCTION:    acpi_ps_get_opcode_size
66  *
67  * PARAMETERS:  Opcode          - An AML opcode
68  *
69  * RETURN:      Size of the opcode, in bytes (1 or 2)
70  *
71  * DESCRIPTION: Get the size of the current opcode.
72  *
73  ******************************************************************************/
acpi_ps_get_opcode_size(u32 opcode)74 u32 acpi_ps_get_opcode_size(u32 opcode)
75 {
76 
77 	/* Extended (2-byte) opcode if > 255 */
78 
79 	if (opcode > 0x00FF) {
80 		return (2);
81 	}
82 
83 	/* Otherwise, just a single byte opcode */
84 
85 	return (1);
86 }
87 
88 /*******************************************************************************
89  *
90  * FUNCTION:    acpi_ps_peek_opcode
91  *
92  * PARAMETERS:  parser_state        - A parser state object
93  *
94  * RETURN:      Next AML opcode
95  *
96  * DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
97  *
98  ******************************************************************************/
99 
acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)100 u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
101 {
102 	u8 *aml;
103 	u16 opcode;
104 
105 	aml = parser_state->aml;
106 	opcode = (u16) ACPI_GET8(aml);
107 
108 	if (opcode == AML_EXTENDED_OP_PREFIX) {
109 
110 		/* Extended opcode, get the second opcode byte */
111 
112 		aml++;
113 		opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
114 	}
115 
116 	return (opcode);
117 }
118 
119 /*******************************************************************************
120  *
121  * FUNCTION:    acpi_ps_complete_this_op
122  *
123  * PARAMETERS:  walk_state      - Current State
124  *              Op              - Op to complete
125  *
126  * RETURN:      Status
127  *
128  * DESCRIPTION: Perform any cleanup at the completion of an Op.
129  *
130  ******************************************************************************/
131 
132 acpi_status
acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,union acpi_parse_object * op)133 acpi_ps_complete_this_op(struct acpi_walk_state * walk_state,
134 			 union acpi_parse_object * op)
135 {
136 	union acpi_parse_object *prev;
137 	union acpi_parse_object *next;
138 	const struct acpi_opcode_info *parent_info;
139 	union acpi_parse_object *replacement_op = NULL;
140 	acpi_status status = AE_OK;
141 
142 	ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);
143 
144 	/* Check for null Op, can happen if AML code is corrupt */
145 
146 	if (!op) {
147 		return_ACPI_STATUS(AE_OK);	/* OK for now */
148 	}
149 
150 	/* Delete this op and the subtree below it if asked to */
151 
152 	if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
153 	     ACPI_PARSE_DELETE_TREE)
154 	    || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
155 		return_ACPI_STATUS(AE_OK);
156 	}
157 
158 	/* Make sure that we only delete this subtree */
159 
160 	if (op->common.parent) {
161 		prev = op->common.parent->common.value.arg;
162 		if (!prev) {
163 
164 			/* Nothing more to do */
165 
166 			goto cleanup;
167 		}
168 
169 		/*
170 		 * Check if we need to replace the operator and its subtree
171 		 * with a return value op (placeholder op)
172 		 */
173 		parent_info =
174 		    acpi_ps_get_opcode_info(op->common.parent->common.
175 					    aml_opcode);
176 
177 		switch (parent_info->class) {
178 		case AML_CLASS_CONTROL:
179 			break;
180 
181 		case AML_CLASS_CREATE:
182 
183 			/*
184 			 * These opcodes contain term_arg operands. The current
185 			 * op must be replaced by a placeholder return op
186 			 */
187 			replacement_op =
188 			    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
189 			if (!replacement_op) {
190 				status = AE_NO_MEMORY;
191 			}
192 			break;
193 
194 		case AML_CLASS_NAMED_OBJECT:
195 
196 			/*
197 			 * These opcodes contain term_arg operands. The current
198 			 * op must be replaced by a placeholder return op
199 			 */
200 			if ((op->common.parent->common.aml_opcode ==
201 			     AML_REGION_OP)
202 			    || (op->common.parent->common.aml_opcode ==
203 				AML_DATA_REGION_OP)
204 			    || (op->common.parent->common.aml_opcode ==
205 				AML_BUFFER_OP)
206 			    || (op->common.parent->common.aml_opcode ==
207 				AML_PACKAGE_OP)
208 			    || (op->common.parent->common.aml_opcode ==
209 				AML_BANK_FIELD_OP)
210 			    || (op->common.parent->common.aml_opcode ==
211 				AML_VAR_PACKAGE_OP)) {
212 				replacement_op =
213 				    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
214 				if (!replacement_op) {
215 					status = AE_NO_MEMORY;
216 				}
217 			} else
218 			    if ((op->common.parent->common.aml_opcode ==
219 				 AML_NAME_OP)
220 				&& (walk_state->pass_number <=
221 				    ACPI_IMODE_LOAD_PASS2)) {
222 				if ((op->common.aml_opcode == AML_BUFFER_OP)
223 				    || (op->common.aml_opcode == AML_PACKAGE_OP)
224 				    || (op->common.aml_opcode ==
225 					AML_VAR_PACKAGE_OP)) {
226 					replacement_op =
227 					    acpi_ps_alloc_op(op->common.
228 							     aml_opcode);
229 					if (!replacement_op) {
230 						status = AE_NO_MEMORY;
231 					} else {
232 						replacement_op->named.data =
233 						    op->named.data;
234 						replacement_op->named.length =
235 						    op->named.length;
236 					}
237 				}
238 			}
239 			break;
240 
241 		default:
242 
243 			replacement_op =
244 			    acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP);
245 			if (!replacement_op) {
246 				status = AE_NO_MEMORY;
247 			}
248 		}
249 
250 		/* We must unlink this op from the parent tree */
251 
252 		if (prev == op) {
253 
254 			/* This op is the first in the list */
255 
256 			if (replacement_op) {
257 				replacement_op->common.parent =
258 				    op->common.parent;
259 				replacement_op->common.value.arg = NULL;
260 				replacement_op->common.node = op->common.node;
261 				op->common.parent->common.value.arg =
262 				    replacement_op;
263 				replacement_op->common.next = op->common.next;
264 			} else {
265 				op->common.parent->common.value.arg =
266 				    op->common.next;
267 			}
268 		}
269 
270 		/* Search the parent list */
271 
272 		else
273 			while (prev) {
274 
275 				/* Traverse all siblings in the parent's argument list */
276 
277 				next = prev->common.next;
278 				if (next == op) {
279 					if (replacement_op) {
280 						replacement_op->common.parent =
281 						    op->common.parent;
282 						replacement_op->common.value.
283 						    arg = NULL;
284 						replacement_op->common.node =
285 						    op->common.node;
286 						prev->common.next =
287 						    replacement_op;
288 						replacement_op->common.next =
289 						    op->common.next;
290 						next = NULL;
291 					} else {
292 						prev->common.next =
293 						    op->common.next;
294 						next = NULL;
295 					}
296 				}
297 				prev = next;
298 			}
299 	}
300 
301       cleanup:
302 
303 	/* Now we can actually delete the subtree rooted at Op */
304 
305 	acpi_ps_delete_parse_tree(op);
306 	return_ACPI_STATUS(status);
307 }
308 
309 /*******************************************************************************
310  *
311  * FUNCTION:    acpi_ps_next_parse_state
312  *
313  * PARAMETERS:  walk_state          - Current state
314  *              Op                  - Current parse op
315  *              callback_status     - Status from previous operation
316  *
317  * RETURN:      Status
318  *
319  * DESCRIPTION: Update the parser state based upon the return exception from
320  *              the parser callback.
321  *
322  ******************************************************************************/
323 
324 acpi_status
acpi_ps_next_parse_state(struct acpi_walk_state * walk_state,union acpi_parse_object * op,acpi_status callback_status)325 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
326 			 union acpi_parse_object *op,
327 			 acpi_status callback_status)
328 {
329 	struct acpi_parse_state *parser_state = &walk_state->parser_state;
330 	acpi_status status = AE_CTRL_PENDING;
331 
332 	ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);
333 
334 	switch (callback_status) {
335 	case AE_CTRL_TERMINATE:
336 		/*
337 		 * A control method was terminated via a RETURN statement.
338 		 * The walk of this method is complete.
339 		 */
340 		parser_state->aml = parser_state->aml_end;
341 		status = AE_CTRL_TERMINATE;
342 		break;
343 
344 	case AE_CTRL_BREAK:
345 
346 		parser_state->aml = walk_state->aml_last_while;
347 		walk_state->control_state->common.value = FALSE;
348 		status = AE_CTRL_BREAK;
349 		break;
350 
351 	case AE_CTRL_CONTINUE:
352 
353 		parser_state->aml = walk_state->aml_last_while;
354 		status = AE_CTRL_CONTINUE;
355 		break;
356 
357 	case AE_CTRL_PENDING:
358 
359 		parser_state->aml = walk_state->aml_last_while;
360 		break;
361 
362 #if 0
363 	case AE_CTRL_SKIP:
364 
365 		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
366 		status = AE_OK;
367 		break;
368 #endif
369 
370 	case AE_CTRL_TRUE:
371 		/*
372 		 * Predicate of an IF was true, and we are at the matching ELSE.
373 		 * Just close out this package
374 		 */
375 		parser_state->aml = acpi_ps_get_next_package_end(parser_state);
376 		status = AE_CTRL_PENDING;
377 		break;
378 
379 	case AE_CTRL_FALSE:
380 		/*
381 		 * Either an IF/WHILE Predicate was false or we encountered a BREAK
382 		 * opcode.  In both cases, we do not execute the rest of the
383 		 * package;  We simply close out the parent (finishing the walk of
384 		 * this branch of the tree) and continue execution at the parent
385 		 * level.
386 		 */
387 		parser_state->aml = parser_state->scope->parse_scope.pkg_end;
388 
389 		/* In the case of a BREAK, just force a predicate (if any) to FALSE */
390 
391 		walk_state->control_state->common.value = FALSE;
392 		status = AE_CTRL_END;
393 		break;
394 
395 	case AE_CTRL_TRANSFER:
396 
397 		/* A method call (invocation) -- transfer control */
398 
399 		status = AE_CTRL_TRANSFER;
400 		walk_state->prev_op = op;
401 		walk_state->method_call_op = op;
402 		walk_state->method_call_node =
403 		    (op->common.value.arg)->common.node;
404 
405 		/* Will return value (if any) be used by the caller? */
406 
407 		walk_state->return_used =
408 		    acpi_ds_is_result_used(op, walk_state);
409 		break;
410 
411 	default:
412 
413 		status = callback_status;
414 		if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) {
415 			status = AE_OK;
416 		}
417 		break;
418 	}
419 
420 	return_ACPI_STATUS(status);
421 }
422 
423 /*******************************************************************************
424  *
425  * FUNCTION:    acpi_ps_parse_aml
426  *
427  * PARAMETERS:  walk_state      - Current state
428  *
429  *
430  * RETURN:      Status
431  *
432  * DESCRIPTION: Parse raw AML and return a tree of ops
433  *
434  ******************************************************************************/
435 
acpi_ps_parse_aml(struct acpi_walk_state * walk_state)436 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
437 {
438 	acpi_status status;
439 	struct acpi_thread_state *thread;
440 	struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
441 	struct acpi_walk_state *previous_walk_state;
442 
443 	ACPI_FUNCTION_TRACE(ps_parse_aml);
444 
445 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
446 			  "Entered with WalkState=%p Aml=%p size=%X\n",
447 			  walk_state, walk_state->parser_state.aml,
448 			  walk_state->parser_state.aml_size));
449 
450 	if (!walk_state->parser_state.aml) {
451 		return_ACPI_STATUS(AE_NULL_OBJECT);
452 	}
453 
454 	/* Create and initialize a new thread state */
455 
456 	thread = acpi_ut_create_thread_state();
457 	if (!thread) {
458 		if (walk_state->method_desc) {
459 
460 			/* Executing a control method - additional cleanup */
461 
462 			acpi_ds_terminate_control_method(
463 				walk_state->method_desc, walk_state);
464 		}
465 
466 		acpi_ds_delete_walk_state(walk_state);
467 		return_ACPI_STATUS(AE_NO_MEMORY);
468 	}
469 
470 	walk_state->thread = thread;
471 
472 	/*
473 	 * If executing a method, the starting sync_level is this method's
474 	 * sync_level
475 	 */
476 	if (walk_state->method_desc) {
477 		walk_state->thread->current_sync_level =
478 		    walk_state->method_desc->method.sync_level;
479 	}
480 
481 	acpi_ds_push_walk_state(walk_state, thread);
482 
483 	/*
484 	 * This global allows the AML debugger to get a handle to the currently
485 	 * executing control method.
486 	 */
487 	acpi_gbl_current_walk_list = thread;
488 
489 	/*
490 	 * Execute the walk loop as long as there is a valid Walk State.  This
491 	 * handles nested control method invocations without recursion.
492 	 */
493 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));
494 
495 	status = AE_OK;
496 	while (walk_state) {
497 		if (ACPI_SUCCESS(status)) {
498 			/*
499 			 * The parse_loop executes AML until the method terminates
500 			 * or calls another method.
501 			 */
502 			status = acpi_ps_parse_loop(walk_state);
503 		}
504 
505 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
506 				  "Completed one call to walk loop, %s State=%p\n",
507 				  acpi_format_exception(status), walk_state));
508 
509 		if (status == AE_CTRL_TRANSFER) {
510 			/*
511 			 * A method call was detected.
512 			 * Transfer control to the called control method
513 			 */
514 			status =
515 			    acpi_ds_call_control_method(thread, walk_state,
516 							NULL);
517 			if (ACPI_FAILURE(status)) {
518 				status =
519 				    acpi_ds_method_error(status, walk_state);
520 			}
521 
522 			/*
523 			 * If the transfer to the new method method call worked, a new walk
524 			 * state was created -- get it
525 			 */
526 			walk_state = acpi_ds_get_current_walk_state(thread);
527 			continue;
528 		} else if (status == AE_CTRL_TERMINATE) {
529 			status = AE_OK;
530 		} else if ((status != AE_OK) && (walk_state->method_desc)) {
531 
532 			/* Either the method parse or actual execution failed */
533 
534 			ACPI_ERROR_METHOD("Method parse/execution failed",
535 					  walk_state->method_node, NULL,
536 					  status);
537 
538 			/* Check for possible multi-thread reentrancy problem */
539 
540 			if ((status == AE_ALREADY_EXISTS) &&
541 			    (!(walk_state->method_desc->method.
542 			       info_flags & ACPI_METHOD_SERIALIZED))) {
543 				/*
544 				 * Method is not serialized and tried to create an object
545 				 * twice. The probable cause is that the method cannot
546 				 * handle reentrancy. Mark as "pending serialized" now, and
547 				 * then mark "serialized" when the last thread exits.
548 				 */
549 				walk_state->method_desc->method.info_flags |=
550 				    ACPI_METHOD_SERIALIZED_PENDING;
551 			}
552 		}
553 
554 		/* We are done with this walk, move on to the parent if any */
555 
556 		walk_state = acpi_ds_pop_walk_state(thread);
557 
558 		/* Reset the current scope to the beginning of scope stack */
559 
560 		acpi_ds_scope_stack_clear(walk_state);
561 
562 		/*
563 		 * If we just returned from the execution of a control method or if we
564 		 * encountered an error during the method parse phase, there's lots of
565 		 * cleanup to do
566 		 */
567 		if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
568 		     ACPI_PARSE_EXECUTE) || (ACPI_FAILURE(status))) {
569 			acpi_ds_terminate_control_method(walk_state->
570 							 method_desc,
571 							 walk_state);
572 		}
573 
574 		/* Delete this walk state and all linked control states */
575 
576 		acpi_ps_cleanup_scope(&walk_state->parser_state);
577 		previous_walk_state = walk_state;
578 
579 		ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
580 				  "ReturnValue=%p, ImplicitValue=%p State=%p\n",
581 				  walk_state->return_desc,
582 				  walk_state->implicit_return_obj, walk_state));
583 
584 		/* Check if we have restarted a preempted walk */
585 
586 		walk_state = acpi_ds_get_current_walk_state(thread);
587 		if (walk_state) {
588 			if (ACPI_SUCCESS(status)) {
589 				/*
590 				 * There is another walk state, restart it.
591 				 * If the method return value is not used by the parent,
592 				 * The object is deleted
593 				 */
594 				if (!previous_walk_state->return_desc) {
595 					/*
596 					 * In slack mode execution, if there is no return value
597 					 * we should implicitly return zero (0) as a default value.
598 					 */
599 					if (acpi_gbl_enable_interpreter_slack &&
600 					    !previous_walk_state->
601 					    implicit_return_obj) {
602 						previous_walk_state->
603 						    implicit_return_obj =
604 						    acpi_ut_create_integer_object
605 						    ((u64) 0);
606 						if (!previous_walk_state->
607 						    implicit_return_obj) {
608 							return_ACPI_STATUS
609 							    (AE_NO_MEMORY);
610 						}
611 					}
612 
613 					/* Restart the calling control method */
614 
615 					status =
616 					    acpi_ds_restart_control_method
617 					    (walk_state,
618 					     previous_walk_state->
619 					     implicit_return_obj);
620 				} else {
621 					/*
622 					 * We have a valid return value, delete any implicit
623 					 * return value.
624 					 */
625 					acpi_ds_clear_implicit_return
626 					    (previous_walk_state);
627 
628 					status =
629 					    acpi_ds_restart_control_method
630 					    (walk_state,
631 					     previous_walk_state->return_desc);
632 				}
633 				if (ACPI_SUCCESS(status)) {
634 					walk_state->walk_type |=
635 					    ACPI_WALK_METHOD_RESTART;
636 				}
637 			} else {
638 				/* On error, delete any return object or implicit return */
639 
640 				acpi_ut_remove_reference(previous_walk_state->
641 							 return_desc);
642 				acpi_ds_clear_implicit_return
643 				    (previous_walk_state);
644 			}
645 		}
646 
647 		/*
648 		 * Just completed a 1st-level method, save the final internal return
649 		 * value (if any)
650 		 */
651 		else if (previous_walk_state->caller_return_desc) {
652 			if (previous_walk_state->implicit_return_obj) {
653 				*(previous_walk_state->caller_return_desc) =
654 				    previous_walk_state->implicit_return_obj;
655 			} else {
656 				/* NULL if no return value */
657 
658 				*(previous_walk_state->caller_return_desc) =
659 				    previous_walk_state->return_desc;
660 			}
661 		} else {
662 			if (previous_walk_state->return_desc) {
663 
664 				/* Caller doesn't want it, must delete it */
665 
666 				acpi_ut_remove_reference(previous_walk_state->
667 							 return_desc);
668 			}
669 			if (previous_walk_state->implicit_return_obj) {
670 
671 				/* Caller doesn't want it, must delete it */
672 
673 				acpi_ut_remove_reference(previous_walk_state->
674 							 implicit_return_obj);
675 			}
676 		}
677 
678 		acpi_ds_delete_walk_state(previous_walk_state);
679 	}
680 
681 	/* Normal exit */
682 
683 	acpi_ex_release_all_mutexes(thread);
684 	acpi_ut_delete_generic_state(ACPI_CAST_PTR
685 				     (union acpi_generic_state, thread));
686 	acpi_gbl_current_walk_list = prev_walk_list;
687 	return_ACPI_STATUS(status);
688 }
689