1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 2 /****************************************************************************** 3 * 4 * Module Name: psparse - Parser top level AML parse routines 5 * 6 * Copyright (C) 2000 - 2020, Intel Corp. 7 * 8 *****************************************************************************/ 9 10 /* 11 * Parse the AML and build an operation tree as most interpreters, 12 * like Perl, do. Parsing is done by hand rather than with a YACC 13 * generated parser to tightly constrain stack and dynamic memory 14 * usage. At the same time, parsing is kept flexible and the code 15 * fairly compact by parsing based on a list of AML opcode 16 * templates in aml_op_info[] 17 */ 18 19 #include <acpi/acpi.h> 20 #include "accommon.h" 21 #include "acparser.h" 22 #include "acdispat.h" 23 #include "amlcode.h" 24 #include "acinterp.h" 25 #include "acnamesp.h" 26 27 #define _COMPONENT ACPI_PARSER 28 ACPI_MODULE_NAME("psparse") 29 30 /******************************************************************************* 31 * 32 * FUNCTION: acpi_ps_get_opcode_size 33 * 34 * PARAMETERS: opcode - An AML opcode 35 * 36 * RETURN: Size of the opcode, in bytes (1 or 2) 37 * 38 * DESCRIPTION: Get the size of the current opcode. 39 * 40 ******************************************************************************/ 41 u32 acpi_ps_get_opcode_size(u32 opcode) 42 { 43 44 /* Extended (2-byte) opcode if > 255 */ 45 46 if (opcode > 0x00FF) { 47 return (2); 48 } 49 50 /* Otherwise, just a single byte opcode */ 51 52 return (1); 53 } 54 55 /******************************************************************************* 56 * 57 * FUNCTION: acpi_ps_peek_opcode 58 * 59 * PARAMETERS: parser_state - A parser state object 60 * 61 * RETURN: Next AML opcode 62 * 63 * DESCRIPTION: Get next AML opcode (without incrementing AML pointer) 64 * 65 ******************************************************************************/ 66 67 u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state) 68 { 69 u8 *aml; 70 u16 opcode; 71 72 aml = parser_state->aml; 73 opcode = (u16) ACPI_GET8(aml); 74 75 if (opcode == AML_EXTENDED_PREFIX) { 76 77 /* Extended opcode, get the second opcode byte */ 78 79 aml++; 80 opcode = (u16) ((opcode << 8) | ACPI_GET8(aml)); 81 } 82 83 return (opcode); 84 } 85 86 /******************************************************************************* 87 * 88 * FUNCTION: acpi_ps_complete_this_op 89 * 90 * PARAMETERS: walk_state - Current State 91 * op - Op to complete 92 * 93 * RETURN: Status 94 * 95 * DESCRIPTION: Perform any cleanup at the completion of an Op. 96 * 97 ******************************************************************************/ 98 99 acpi_status 100 acpi_ps_complete_this_op(struct acpi_walk_state *walk_state, 101 union acpi_parse_object *op) 102 { 103 union acpi_parse_object *prev; 104 union acpi_parse_object *next; 105 const struct acpi_opcode_info *parent_info; 106 union acpi_parse_object *replacement_op = NULL; 107 acpi_status status = AE_OK; 108 109 ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op); 110 111 /* Check for null Op, can happen if AML code is corrupt */ 112 113 if (!op) { 114 return_ACPI_STATUS(AE_OK); /* OK for now */ 115 } 116 117 acpi_ex_stop_trace_opcode(op, walk_state); 118 119 /* Delete this op and the subtree below it if asked to */ 120 121 if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) != 122 ACPI_PARSE_DELETE_TREE) 123 || (walk_state->op_info->class == AML_CLASS_ARGUMENT)) { 124 return_ACPI_STATUS(AE_OK); 125 } 126 127 /* Make sure that we only delete this subtree */ 128 129 if (op->common.parent) { 130 prev = op->common.parent->common.value.arg; 131 if (!prev) { 132 133 /* Nothing more to do */ 134 135 goto cleanup; 136 } 137 138 /* 139 * Check if we need to replace the operator and its subtree 140 * with a return value op (placeholder op) 141 */ 142 parent_info = 143 acpi_ps_get_opcode_info(op->common.parent->common. 144 aml_opcode); 145 146 switch (parent_info->class) { 147 case AML_CLASS_CONTROL: 148 149 break; 150 151 case AML_CLASS_CREATE: 152 /* 153 * These opcodes contain term_arg operands. The current 154 * op must be replaced by a placeholder return op 155 */ 156 replacement_op = 157 acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP, 158 op->common.aml); 159 if (!replacement_op) { 160 status = AE_NO_MEMORY; 161 } 162 break; 163 164 case AML_CLASS_NAMED_OBJECT: 165 /* 166 * These opcodes contain term_arg operands. The current 167 * op must be replaced by a placeholder return op 168 */ 169 if ((op->common.parent->common.aml_opcode == 170 AML_REGION_OP) 171 || (op->common.parent->common.aml_opcode == 172 AML_DATA_REGION_OP) 173 || (op->common.parent->common.aml_opcode == 174 AML_BUFFER_OP) 175 || (op->common.parent->common.aml_opcode == 176 AML_PACKAGE_OP) 177 || (op->common.parent->common.aml_opcode == 178 AML_BANK_FIELD_OP) 179 || (op->common.parent->common.aml_opcode == 180 AML_VARIABLE_PACKAGE_OP)) { 181 replacement_op = 182 acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP, 183 op->common.aml); 184 if (!replacement_op) { 185 status = AE_NO_MEMORY; 186 } 187 } else 188 if ((op->common.parent->common.aml_opcode == 189 AML_NAME_OP) 190 && (walk_state->pass_number <= 191 ACPI_IMODE_LOAD_PASS2)) { 192 if ((op->common.aml_opcode == AML_BUFFER_OP) 193 || (op->common.aml_opcode == AML_PACKAGE_OP) 194 || (op->common.aml_opcode == 195 AML_VARIABLE_PACKAGE_OP)) { 196 replacement_op = 197 acpi_ps_alloc_op(op->common. 198 aml_opcode, 199 op->common.aml); 200 if (!replacement_op) { 201 status = AE_NO_MEMORY; 202 } else { 203 replacement_op->named.data = 204 op->named.data; 205 replacement_op->named.length = 206 op->named.length; 207 } 208 } 209 } 210 break; 211 212 default: 213 214 replacement_op = 215 acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP, 216 op->common.aml); 217 if (!replacement_op) { 218 status = AE_NO_MEMORY; 219 } 220 } 221 222 /* We must unlink this op from the parent tree */ 223 224 if (prev == op) { 225 226 /* This op is the first in the list */ 227 228 if (replacement_op) { 229 replacement_op->common.parent = 230 op->common.parent; 231 replacement_op->common.value.arg = NULL; 232 replacement_op->common.node = op->common.node; 233 op->common.parent->common.value.arg = 234 replacement_op; 235 replacement_op->common.next = op->common.next; 236 } else { 237 op->common.parent->common.value.arg = 238 op->common.next; 239 } 240 } 241 242 /* Search the parent list */ 243 244 else 245 while (prev) { 246 247 /* Traverse all siblings in the parent's argument list */ 248 249 next = prev->common.next; 250 if (next == op) { 251 if (replacement_op) { 252 replacement_op->common.parent = 253 op->common.parent; 254 replacement_op->common.value. 255 arg = NULL; 256 replacement_op->common.node = 257 op->common.node; 258 prev->common.next = 259 replacement_op; 260 replacement_op->common.next = 261 op->common.next; 262 next = NULL; 263 } else { 264 prev->common.next = 265 op->common.next; 266 next = NULL; 267 } 268 } 269 prev = next; 270 } 271 } 272 273 cleanup: 274 275 /* Now we can actually delete the subtree rooted at Op */ 276 277 acpi_ps_delete_parse_tree(op); 278 return_ACPI_STATUS(status); 279 } 280 281 /******************************************************************************* 282 * 283 * FUNCTION: acpi_ps_next_parse_state 284 * 285 * PARAMETERS: walk_state - Current state 286 * op - Current parse op 287 * callback_status - Status from previous operation 288 * 289 * RETURN: Status 290 * 291 * DESCRIPTION: Update the parser state based upon the return exception from 292 * the parser callback. 293 * 294 ******************************************************************************/ 295 296 acpi_status 297 acpi_ps_next_parse_state(struct acpi_walk_state *walk_state, 298 union acpi_parse_object *op, 299 acpi_status callback_status) 300 { 301 struct acpi_parse_state *parser_state = &walk_state->parser_state; 302 acpi_status status = AE_CTRL_PENDING; 303 304 ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op); 305 306 switch (callback_status) { 307 case AE_CTRL_TERMINATE: 308 /* 309 * A control method was terminated via a RETURN statement. 310 * The walk of this method is complete. 311 */ 312 parser_state->aml = parser_state->aml_end; 313 status = AE_CTRL_TERMINATE; 314 break; 315 316 case AE_CTRL_BREAK: 317 318 parser_state->aml = walk_state->aml_last_while; 319 walk_state->control_state->common.value = FALSE; 320 status = AE_CTRL_BREAK; 321 break; 322 323 case AE_CTRL_CONTINUE: 324 325 parser_state->aml = walk_state->aml_last_while; 326 status = AE_CTRL_CONTINUE; 327 break; 328 329 case AE_CTRL_PENDING: 330 331 parser_state->aml = walk_state->aml_last_while; 332 break; 333 334 #if 0 335 case AE_CTRL_SKIP: 336 337 parser_state->aml = parser_state->scope->parse_scope.pkg_end; 338 status = AE_OK; 339 break; 340 #endif 341 342 case AE_CTRL_TRUE: 343 /* 344 * Predicate of an IF was true, and we are at the matching ELSE. 345 * Just close out this package 346 */ 347 parser_state->aml = acpi_ps_get_next_package_end(parser_state); 348 status = AE_CTRL_PENDING; 349 break; 350 351 case AE_CTRL_FALSE: 352 /* 353 * Either an IF/WHILE Predicate was false or we encountered a BREAK 354 * opcode. In both cases, we do not execute the rest of the 355 * package; We simply close out the parent (finishing the walk of 356 * this branch of the tree) and continue execution at the parent 357 * level. 358 */ 359 parser_state->aml = parser_state->scope->parse_scope.pkg_end; 360 361 /* In the case of a BREAK, just force a predicate (if any) to FALSE */ 362 363 walk_state->control_state->common.value = FALSE; 364 status = AE_CTRL_END; 365 break; 366 367 case AE_CTRL_TRANSFER: 368 369 /* A method call (invocation) -- transfer control */ 370 371 status = AE_CTRL_TRANSFER; 372 walk_state->prev_op = op; 373 walk_state->method_call_op = op; 374 walk_state->method_call_node = 375 (op->common.value.arg)->common.node; 376 377 /* Will return value (if any) be used by the caller? */ 378 379 walk_state->return_used = 380 acpi_ds_is_result_used(op, walk_state); 381 break; 382 383 default: 384 385 status = callback_status; 386 if ((callback_status & AE_CODE_MASK) == AE_CODE_CONTROL) { 387 status = AE_OK; 388 } 389 break; 390 } 391 392 return_ACPI_STATUS(status); 393 } 394 395 /******************************************************************************* 396 * 397 * FUNCTION: acpi_ps_parse_aml 398 * 399 * PARAMETERS: walk_state - Current state 400 * 401 * 402 * RETURN: Status 403 * 404 * DESCRIPTION: Parse raw AML and return a tree of ops 405 * 406 ******************************************************************************/ 407 408 acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state) 409 { 410 acpi_status status; 411 struct acpi_thread_state *thread; 412 struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list; 413 struct acpi_walk_state *previous_walk_state; 414 415 ACPI_FUNCTION_TRACE(ps_parse_aml); 416 417 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 418 "Entered with WalkState=%p Aml=%p size=%X\n", 419 walk_state, walk_state->parser_state.aml, 420 walk_state->parser_state.aml_size)); 421 422 if (!walk_state->parser_state.aml) { 423 return_ACPI_STATUS(AE_BAD_ADDRESS); 424 } 425 426 /* Create and initialize a new thread state */ 427 428 thread = acpi_ut_create_thread_state(); 429 if (!thread) { 430 if (walk_state->method_desc) { 431 432 /* Executing a control method - additional cleanup */ 433 434 acpi_ds_terminate_control_method(walk_state-> 435 method_desc, 436 walk_state); 437 } 438 439 acpi_ds_delete_walk_state(walk_state); 440 return_ACPI_STATUS(AE_NO_MEMORY); 441 } 442 443 walk_state->thread = thread; 444 445 /* 446 * If executing a method, the starting sync_level is this method's 447 * sync_level 448 */ 449 if (walk_state->method_desc) { 450 walk_state->thread->current_sync_level = 451 walk_state->method_desc->method.sync_level; 452 } 453 454 acpi_ds_push_walk_state(walk_state, thread); 455 456 /* 457 * This global allows the AML debugger to get a handle to the currently 458 * executing control method. 459 */ 460 acpi_gbl_current_walk_list = thread; 461 462 /* 463 * Execute the walk loop as long as there is a valid Walk State. This 464 * handles nested control method invocations without recursion. 465 */ 466 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state)); 467 468 status = AE_OK; 469 while (walk_state) { 470 if (ACPI_SUCCESS(status)) { 471 /* 472 * The parse_loop executes AML until the method terminates 473 * or calls another method. 474 */ 475 status = acpi_ps_parse_loop(walk_state); 476 } 477 478 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 479 "Completed one call to walk loop, %s State=%p\n", 480 acpi_format_exception(status), walk_state)); 481 482 if (walk_state->method_pathname && walk_state->method_is_nested) { 483 484 /* Optional object evaluation log */ 485 486 ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION, 487 "%-26s: %*s%s\n", 488 " Exit nested method", 489 (walk_state-> 490 method_nesting_depth + 1) * 3, 491 " ", 492 &walk_state->method_pathname[1])); 493 494 ACPI_FREE(walk_state->method_pathname); 495 walk_state->method_is_nested = FALSE; 496 } 497 if (status == AE_CTRL_TRANSFER) { 498 /* 499 * A method call was detected. 500 * Transfer control to the called control method 501 */ 502 status = 503 acpi_ds_call_control_method(thread, walk_state, 504 NULL); 505 if (ACPI_FAILURE(status)) { 506 status = 507 acpi_ds_method_error(status, walk_state); 508 } 509 510 /* 511 * If the transfer to the new method method call worked, 512 * a new walk state was created -- get it 513 */ 514 walk_state = acpi_ds_get_current_walk_state(thread); 515 continue; 516 } else if (status == AE_CTRL_TERMINATE) { 517 status = AE_OK; 518 } else if ((status != AE_OK) && (walk_state->method_desc)) { 519 520 /* Either the method parse or actual execution failed */ 521 522 acpi_ex_exit_interpreter(); 523 if (status == AE_ABORT_METHOD) { 524 acpi_ns_print_node_pathname(walk_state-> 525 method_node, 526 "Aborting method"); 527 acpi_os_printf("\n"); 528 } else { 529 ACPI_ERROR_METHOD("Aborting method", 530 walk_state->method_node, NULL, 531 status); 532 } 533 acpi_ex_enter_interpreter(); 534 535 /* Check for possible multi-thread reentrancy problem */ 536 537 if ((status == AE_ALREADY_EXISTS) && 538 (!(walk_state->method_desc->method.info_flags & 539 ACPI_METHOD_SERIALIZED))) { 540 /* 541 * Method is not serialized and tried to create an object 542 * twice. The probable cause is that the method cannot 543 * handle reentrancy. Mark as "pending serialized" now, and 544 * then mark "serialized" when the last thread exits. 545 */ 546 walk_state->method_desc->method.info_flags |= 547 ACPI_METHOD_SERIALIZED_PENDING; 548 } 549 } 550 551 /* We are done with this walk, move on to the parent if any */ 552 553 walk_state = acpi_ds_pop_walk_state(thread); 554 555 /* Reset the current scope to the beginning of scope stack */ 556 557 acpi_ds_scope_stack_clear(walk_state); 558 559 /* 560 * If we just returned from the execution of a control method or if we 561 * encountered an error during the method parse phase, there's lots of 562 * cleanup to do 563 */ 564 if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) == 565 ACPI_PARSE_EXECUTE && 566 !(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) || 567 (ACPI_FAILURE(status))) { 568 acpi_ds_terminate_control_method(walk_state-> 569 method_desc, 570 walk_state); 571 } 572 573 /* Delete this walk state and all linked control states */ 574 575 acpi_ps_cleanup_scope(&walk_state->parser_state); 576 previous_walk_state = walk_state; 577 578 ACPI_DEBUG_PRINT((ACPI_DB_PARSE, 579 "ReturnValue=%p, ImplicitValue=%p State=%p\n", 580 walk_state->return_desc, 581 walk_state->implicit_return_obj, walk_state)); 582 583 /* Check if we have restarted a preempted walk */ 584 585 walk_state = acpi_ds_get_current_walk_state(thread); 586 if (walk_state) { 587 if (ACPI_SUCCESS(status)) { 588 /* 589 * There is another walk state, restart it. 590 * If the method return value is not used by the parent, 591 * The object is deleted 592 */ 593 if (!previous_walk_state->return_desc) { 594 /* 595 * In slack mode execution, if there is no return value 596 * we should implicitly return zero (0) as a default value. 597 */ 598 if (acpi_gbl_enable_interpreter_slack && 599 !previous_walk_state-> 600 implicit_return_obj) { 601 previous_walk_state-> 602 implicit_return_obj = 603 acpi_ut_create_integer_object 604 ((u64) 0); 605 if (!previous_walk_state-> 606 implicit_return_obj) { 607 return_ACPI_STATUS 608 (AE_NO_MEMORY); 609 } 610 } 611 612 /* Restart the calling control method */ 613 614 status = 615 acpi_ds_restart_control_method 616 (walk_state, 617 previous_walk_state-> 618 implicit_return_obj); 619 } else { 620 /* 621 * We have a valid return value, delete any implicit 622 * return value. 623 */ 624 acpi_ds_clear_implicit_return 625 (previous_walk_state); 626 627 status = 628 acpi_ds_restart_control_method 629 (walk_state, 630 previous_walk_state->return_desc); 631 } 632 if (ACPI_SUCCESS(status)) { 633 walk_state->walk_type |= 634 ACPI_WALK_METHOD_RESTART; 635 } 636 } else { 637 /* On error, delete any return object or implicit return */ 638 639 acpi_ut_remove_reference(previous_walk_state-> 640 return_desc); 641 acpi_ds_clear_implicit_return 642 (previous_walk_state); 643 } 644 } 645 646 /* 647 * Just completed a 1st-level method, save the final internal return 648 * value (if any) 649 */ 650 else if (previous_walk_state->caller_return_desc) { 651 if (previous_walk_state->implicit_return_obj) { 652 *(previous_walk_state->caller_return_desc) = 653 previous_walk_state->implicit_return_obj; 654 } else { 655 /* NULL if no return value */ 656 657 *(previous_walk_state->caller_return_desc) = 658 previous_walk_state->return_desc; 659 } 660 } else { 661 if (previous_walk_state->return_desc) { 662 663 /* Caller doesn't want it, must delete it */ 664 665 acpi_ut_remove_reference(previous_walk_state-> 666 return_desc); 667 } 668 if (previous_walk_state->implicit_return_obj) { 669 670 /* Caller doesn't want it, must delete it */ 671 672 acpi_ut_remove_reference(previous_walk_state-> 673 implicit_return_obj); 674 } 675 } 676 677 acpi_ds_delete_walk_state(previous_walk_state); 678 } 679 680 /* Normal exit */ 681 682 acpi_ex_release_all_mutexes(thread); 683 acpi_ut_delete_generic_state(ACPI_CAST_PTR 684 (union acpi_generic_state, thread)); 685 acpi_gbl_current_walk_list = prev_walk_list; 686 return_ACPI_STATUS(status); 687 } 688