drivers/acpi/acpica/psparse.c

   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 - 2021, 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 (ACPI_CNTL_EXCEPTION(callback_status)) {
 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 }