Pileus Git - ~andy/linux/blob - drivers/acpi/acpica/nspredef.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nspredef - Validation of ACPI predefined methods and objects
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, 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 #define ACPI_CREATE_PREDEFINED_TABLE
  45
  46 #include <acpi/acpi.h>
  47 #include "accommon.h"
  48 #include "acnamesp.h"
  49 #include "acpredef.h"
  50
  51 #define _COMPONENT          ACPI_NAMESPACE
  52 ACPI_MODULE_NAME("nspredef")
  53
  54 /*******************************************************************************
  55  *
  56  * This module validates predefined ACPI objects that appear in the namespace,
  57  * at the time they are evaluated (via acpi_evaluate_object). The purpose of this
  58  * validation is to detect problems with BIOS-exposed predefined ACPI objects
  59  * before the results are returned to the ACPI-related drivers.
  60  *
  61  * There are several areas that are validated:
  62  *
  63  *  1) The number of input arguments as defined by the method/object in the
  64  *      ASL is validated against the ACPI specification.
  65  *  2) The type of the return object (if any) is validated against the ACPI
  66  *      specification.
  67  *  3) For returned package objects, the count of package elements is
  68  *      validated, as well as the type of each package element. Nested
  69  *      packages are supported.
  70  *
  71  * For any problems found, a warning message is issued.
  72  *
  73  ******************************************************************************/
  74 /* Local prototypes */
  75 static acpi_status
  76 acpi_ns_check_reference(struct acpi_predefined_data *data,
  77                         union acpi_operand_object *return_object);
  78
  79 static void acpi_ns_get_expected_types(char *buffer, u32 expected_btypes);
  80
  81 /*
  82  * Names for the types that can be returned by the predefined objects.
  83  * Used for warning messages. Must be in the same order as the ACPI_RTYPEs
  84  */
  85 static const char *acpi_rtype_names[] = {
  86         "/Integer",
  87         "/String",
  88         "/Buffer",
  89         "/Package",
  90         "/Reference",
  91 };
  92
  93 /*******************************************************************************
  94  *
  95  * FUNCTION:    acpi_ns_check_predefined_names
  96  *
  97  * PARAMETERS:  node            - Namespace node for the method/object
  98  *              user_param_count - Number of parameters actually passed
  99  *              return_status   - Status from the object evaluation
 100  *              return_object_ptr - Pointer to the object returned from the
 101  *                                evaluation of a method or object
 102  *
 103  * RETURN:      Status
 104  *
 105  * DESCRIPTION: Check an ACPI name for a match in the predefined name list.
 106  *
 107  ******************************************************************************/
 108
 109 acpi_status
 110 acpi_ns_check_predefined_names(struct acpi_namespace_node *node,
 111                                u32 user_param_count,
 112                                acpi_status return_status,
 113                                union acpi_operand_object **return_object_ptr)
 114 {
 115         union acpi_operand_object *return_object = *return_object_ptr;
 116         acpi_status status = AE_OK;
 117         const union acpi_predefined_info *predefined;
 118         char *pathname;
 119         struct acpi_predefined_data *data;
 120
 121         /* Match the name for this method/object against the predefined list */
 122
 123         predefined = acpi_ns_check_for_predefined_name(node);
 124
 125         /* Get the full pathname to the object, for use in warning messages */
 126
 127         pathname = acpi_ns_get_external_pathname(node);
 128         if (!pathname) {
 129                 return (AE_OK); /* Could not get pathname, ignore */
 130         }
 131
 132         /*
 133          * Check that the parameter count for this method matches the ASL
 134          * definition. For predefined names, ensure that both the caller and
 135          * the method itself are in accordance with the ACPI specification.
 136          */
 137         acpi_ns_check_parameter_count(pathname, node, user_param_count,
 138                                       predefined);
 139
 140         /* If not a predefined name, we cannot validate the return object */
 141
 142         if (!predefined) {
 143                 goto cleanup;
 144         }
 145
 146         /*
 147          * If the method failed or did not actually return an object, we cannot
 148          * validate the return object
 149          */
 150         if ((return_status != AE_OK) && (return_status != AE_CTRL_RETURN_VALUE)) {
 151                 goto cleanup;
 152         }
 153
 154         /*
 155          * If there is no return value, check if we require a return value for
 156          * this predefined name. Either one return value is expected, or none,
 157          * for both methods and other objects.
 158          *
 159          * Exit now if there is no return object. Warning if one was expected.
 160          */
 161         if (!return_object) {
 162                 if ((predefined->info.expected_btypes) &&
 163                     (!(predefined->info.expected_btypes & ACPI_RTYPE_NONE))) {
 164                         ACPI_WARN_PREDEFINED((AE_INFO, pathname,
 165                                               ACPI_WARN_ALWAYS,
 166                                               "Missing expected return value"));
 167
 168                         status = AE_AML_NO_RETURN_VALUE;
 169                 }
 170                 goto cleanup;
 171         }
 172
 173         /*
 174          * Return value validation and possible repair.
 175          *
 176          * 1) Don't perform return value validation/repair if this feature
 177          * has been disabled via a global option.
 178          *
 179          * 2) We have a return value, but if one wasn't expected, just exit,
 180          * this is not a problem. For example, if the "Implicit Return"
 181          * feature is enabled, methods will always return a value.
 182          *
 183          * 3) If the return value can be of any type, then we cannot perform
 184          * any validation, just exit.
 185          */
 186         if (acpi_gbl_disable_auto_repair ||
 187             (!predefined->info.expected_btypes) ||
 188             (predefined->info.expected_btypes == ACPI_RTYPE_ALL)) {
 189                 goto cleanup;
 190         }
 191
 192         /* Create the parameter data block for object validation */
 193
 194         data = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_predefined_data));
 195         if (!data) {
 196                 goto cleanup;
 197         }
 198         data->predefined = predefined;
 199         data->node = node;
 200         data->node_flags = node->flags;
 201         data->pathname = pathname;
 202
 203         /*
 204          * Check that the type of the main return object is what is expected
 205          * for this predefined name
 206          */
 207         status = acpi_ns_check_object_type(data, return_object_ptr,
 208                                            predefined->info.expected_btypes,
 209                                            ACPI_NOT_PACKAGE_ELEMENT);
 210         if (ACPI_FAILURE(status)) {
 211                 goto exit;
 212         }
 213
 214         /*
 215          * For returned Package objects, check the type of all sub-objects.
 216          * Note: Package may have been newly created by call above.
 217          */
 218         if ((*return_object_ptr)->common.type == ACPI_TYPE_PACKAGE) {
 219                 data->parent_package = *return_object_ptr;
 220                 status = acpi_ns_check_package(data, return_object_ptr);
 221                 if (ACPI_FAILURE(status)) {
 222                         goto exit;
 223                 }
 224         }
 225
 226         /*
 227          * The return object was OK, or it was successfully repaired above.
 228          * Now make some additional checks such as verifying that package
 229          * objects are sorted correctly (if required) or buffer objects have
 230          * the correct data width (bytes vs. dwords). These repairs are
 231          * performed on a per-name basis, i.e., the code is specific to
 232          * particular predefined names.
 233          */
 234         status = acpi_ns_complex_repairs(data, node, status, return_object_ptr);
 235
 236 exit:
 237         /*
 238          * If the object validation failed or if we successfully repaired one
 239          * or more objects, mark the parent node to suppress further warning
 240          * messages during the next evaluation of the same method/object.
 241          */
 242         if (ACPI_FAILURE(status) || (data->flags & ACPI_OBJECT_REPAIRED)) {
 243                 node->flags |= ANOBJ_EVALUATED;
 244         }
 245         ACPI_FREE(data);
 246
 247 cleanup:
 248         ACPI_FREE(pathname);
 249         return (status);
 250 }
 251
 252 /*******************************************************************************
 253  *
 254  * FUNCTION:    acpi_ns_check_parameter_count
 255  *
 256  * PARAMETERS:  pathname        - Full pathname to the node (for error msgs)
 257  *              node            - Namespace node for the method/object
 258  *              user_param_count - Number of args passed in by the caller
 259  *              predefined      - Pointer to entry in predefined name table
 260  *
 261  * RETURN:      None
 262  *
 263  * DESCRIPTION: Check that the declared (in ASL/AML) parameter count for a
 264  *              predefined name is what is expected (i.e., what is defined in
 265  *              the ACPI specification for this predefined name.)
 266  *
 267  ******************************************************************************/
 268
 269 void
 270 acpi_ns_check_parameter_count(char *pathname,
 271                               struct acpi_namespace_node *node,
 272                               u32 user_param_count,
 273                               const union acpi_predefined_info *predefined)
 274 {
 275         u32 param_count;
 276         u32 required_params_current;
 277         u32 required_params_old;
 278
 279         /* Methods have 0-7 parameters. All other types have zero. */
 280
 281         param_count = 0;
 282         if (node->type == ACPI_TYPE_METHOD) {
 283                 param_count = node->object->method.param_count;
 284         }
 285
 286         if (!predefined) {
 287                 /*
 288                  * Check the parameter count for non-predefined methods/objects.
 289                  *
 290                  * Warning if too few or too many arguments have been passed by the
 291                  * caller. An incorrect number of arguments may not cause the method
 292                  * to fail. However, the method will fail if there are too few
 293                  * arguments and the method attempts to use one of the missing ones.
 294                  */
 295                 if (user_param_count < param_count) {
 296                         ACPI_WARN_PREDEFINED((AE_INFO, pathname,
 297                                               ACPI_WARN_ALWAYS,
 298                                               "Insufficient arguments - needs %u, found %u",
 299                                               param_count, user_param_count));
 300                 } else if (user_param_count > param_count) {
 301                         ACPI_WARN_PREDEFINED((AE_INFO, pathname,
 302                                               ACPI_WARN_ALWAYS,
 303                                               "Excess arguments - needs %u, found %u",
 304                                               param_count, user_param_count));
 305                 }
 306                 return;
 307         }
 308
 309         /*
 310          * Validate the user-supplied parameter count.
 311          * Allow two different legal argument counts (_SCP, etc.)
 312          */
 313         required_params_current = predefined->info.param_count & 0x0F;
 314         required_params_old = predefined->info.param_count >> 4;
 315
 316         if (user_param_count != ACPI_UINT32_MAX) {
 317                 if ((user_param_count != required_params_current) &&
 318                     (user_param_count != required_params_old)) {
 319                         ACPI_WARN_PREDEFINED((AE_INFO, pathname,
 320                                               ACPI_WARN_ALWAYS,
 321                                               "Parameter count mismatch - "
 322                                               "caller passed %u, ACPI requires %u",
 323                                               user_param_count,
 324                                               required_params_current));
 325                 }
 326         }
 327
 328         /*
 329          * Check that the ASL-defined parameter count is what is expected for
 330          * this predefined name (parameter count as defined by the ACPI
 331          * specification)
 332          */
 333         if ((param_count != required_params_current) &&
 334             (param_count != required_params_old)) {
 335                 ACPI_WARN_PREDEFINED((AE_INFO, pathname, node->flags,
 336                                       "Parameter count mismatch - ASL declared %u, ACPI requires %u",
 337                                       param_count, required_params_current));
 338         }
 339 }
 340
 341 /*******************************************************************************
 342  *
 343  * FUNCTION:    acpi_ns_check_for_predefined_name
 344  *
 345  * PARAMETERS:  node            - Namespace node for the method/object
 346  *
 347  * RETURN:      Pointer to entry in predefined table. NULL indicates not found.
 348  *
 349  * DESCRIPTION: Check an object name against the predefined object list.
 350  *
 351  ******************************************************************************/
 352
 353 const union acpi_predefined_info *acpi_ns_check_for_predefined_name(struct
 354                                                                     acpi_namespace_node
 355                                                                     *node)
 356 {
 357         const union acpi_predefined_info *this_name;
 358
 359         /* Quick check for a predefined name, first character must be underscore */
 360
 361         if (node->name.ascii[0] != '_') {
 362                 return (NULL);
 363         }
 364
 365         /* Search info table for a predefined method/object name */
 366
 367         this_name = predefined_names;
 368         while (this_name->info.name[0]) {
 369                 if (ACPI_COMPARE_NAME(node->name.ascii, this_name->info.name)) {
 370                         return (this_name);
 371                 }
 372
 373                 /*
 374                  * Skip next entry in the table if this name returns a Package
 375                  * (next entry contains the package info)
 376                  */
 377                 if (this_name->info.expected_btypes & ACPI_RTYPE_PACKAGE) {
 378                         this_name++;
 379                 }
 380
 381                 this_name++;
 382         }
 383
 384         return (NULL);          /* Not found */
 385 }
 386
 387 /*******************************************************************************
 388  *
 389  * FUNCTION:    acpi_ns_check_object_type
 390  *
 391  * PARAMETERS:  data            - Pointer to validation data structure
 392  *              return_object_ptr - Pointer to the object returned from the
 393  *                                evaluation of a method or object
 394  *              expected_btypes - Bitmap of expected return type(s)
 395  *              package_index   - Index of object within parent package (if
 396  *                                applicable - ACPI_NOT_PACKAGE_ELEMENT
 397  *                                otherwise)
 398  *
 399  * RETURN:      Status
 400  *
 401  * DESCRIPTION: Check the type of the return object against the expected object
 402  *              type(s). Use of Btype allows multiple expected object types.
 403  *
 404  ******************************************************************************/
 405
 406 acpi_status
 407 acpi_ns_check_object_type(struct acpi_predefined_data *data,
 408                           union acpi_operand_object **return_object_ptr,
 409                           u32 expected_btypes, u32 package_index)
 410 {
 411         union acpi_operand_object *return_object = *return_object_ptr;
 412         acpi_status status = AE_OK;
 413         u32 return_btype;
 414         char type_buffer[48];   /* Room for 5 types */
 415
 416         /*
 417          * If we get a NULL return_object here, it is a NULL package element.
 418          * Since all extraneous NULL package elements were removed earlier by a
 419          * call to acpi_ns_remove_null_elements, this is an unexpected NULL element.
 420          * We will attempt to repair it.
 421          */
 422         if (!return_object) {
 423                 status = acpi_ns_repair_null_element(data, expected_btypes,
 424                                                      package_index,
 425                                                      return_object_ptr);
 426                 if (ACPI_SUCCESS(status)) {
 427                         return (AE_OK); /* Repair was successful */
 428                 }
 429                 goto type_error_exit;
 430         }
 431
 432         /* A Namespace node should not get here, but make sure */
 433
 434         if (ACPI_GET_DESCRIPTOR_TYPE(return_object) == ACPI_DESC_TYPE_NAMED) {
 435                 ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 436                                       "Invalid return type - Found a Namespace node [%4.4s] type %s",
 437                                       return_object->node.name.ascii,
 438                                       acpi_ut_get_type_name(return_object->node.
 439                                                             type)));
 440                 return (AE_AML_OPERAND_TYPE);
 441         }
 442
 443         /*
 444          * Convert the object type (ACPI_TYPE_xxx) to a bitmapped object type.
 445          * The bitmapped type allows multiple possible return types.
 446          *
 447          * Note, the cases below must handle all of the possible types returned
 448          * from all of the predefined names (including elements of returned
 449          * packages)
 450          */
 451         switch (return_object->common.type) {
 452         case ACPI_TYPE_INTEGER:
 453                 return_btype = ACPI_RTYPE_INTEGER;
 454                 break;
 455
 456         case ACPI_TYPE_BUFFER:
 457                 return_btype = ACPI_RTYPE_BUFFER;
 458                 break;
 459
 460         case ACPI_TYPE_STRING:
 461                 return_btype = ACPI_RTYPE_STRING;
 462                 break;
 463
 464         case ACPI_TYPE_PACKAGE:
 465                 return_btype = ACPI_RTYPE_PACKAGE;
 466                 break;
 467
 468         case ACPI_TYPE_LOCAL_REFERENCE:
 469                 return_btype = ACPI_RTYPE_REFERENCE;
 470                 break;
 471
 472         default:
 473                 /* Not one of the supported objects, must be incorrect */
 474
 475                 goto type_error_exit;
 476         }
 477
 478         /* Is the object one of the expected types? */
 479
 480         if (return_btype & expected_btypes) {
 481
 482                 /* For reference objects, check that the reference type is correct */
 483
 484                 if (return_object->common.type == ACPI_TYPE_LOCAL_REFERENCE) {
 485                         status = acpi_ns_check_reference(data, return_object);
 486                 }
 487
 488                 return (status);
 489         }
 490
 491         /* Type mismatch -- attempt repair of the returned object */
 492
 493         status = acpi_ns_repair_object(data, expected_btypes,
 494                                        package_index, return_object_ptr);
 495         if (ACPI_SUCCESS(status)) {
 496                 return (AE_OK); /* Repair was successful */
 497         }
 498
 499       type_error_exit:
 500
 501         /* Create a string with all expected types for this predefined object */
 502
 503         acpi_ns_get_expected_types(type_buffer, expected_btypes);
 504
 505         if (package_index == ACPI_NOT_PACKAGE_ELEMENT) {
 506                 ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 507                                       "Return type mismatch - found %s, expected %s",
 508                                       acpi_ut_get_object_type_name
 509                                       (return_object), type_buffer));
 510         } else {
 511                 ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 512                                       "Return Package type mismatch at index %u - "
 513                                       "found %s, expected %s", package_index,
 514                                       acpi_ut_get_object_type_name
 515                                       (return_object), type_buffer));
 516         }
 517
 518         return (AE_AML_OPERAND_TYPE);
 519 }
 520
 521 /*******************************************************************************
 522  *
 523  * FUNCTION:    acpi_ns_check_reference
 524  *
 525  * PARAMETERS:  data            - Pointer to validation data structure
 526  *              return_object   - Object returned from the evaluation of a
 527  *                                method or object
 528  *
 529  * RETURN:      Status
 530  *
 531  * DESCRIPTION: Check a returned reference object for the correct reference
 532  *              type. The only reference type that can be returned from a
 533  *              predefined method is a named reference. All others are invalid.
 534  *
 535  ******************************************************************************/
 536
 537 static acpi_status
 538 acpi_ns_check_reference(struct acpi_predefined_data *data,
 539                         union acpi_operand_object *return_object)
 540 {
 541
 542         /*
 543          * Check the reference object for the correct reference type (opcode).
 544          * The only type of reference that can be converted to an union acpi_object is
 545          * a reference to a named object (reference class: NAME)
 546          */
 547         if (return_object->reference.class == ACPI_REFCLASS_NAME) {
 548                 return (AE_OK);
 549         }
 550
 551         ACPI_WARN_PREDEFINED((AE_INFO, data->pathname, data->node_flags,
 552                               "Return type mismatch - unexpected reference object type [%s] %2.2X",
 553                               acpi_ut_get_reference_name(return_object),
 554                               return_object->reference.class));
 555
 556         return (AE_AML_OPERAND_TYPE);
 557 }
 558
 559 /*******************************************************************************
 560  *
 561  * FUNCTION:    acpi_ns_get_expected_types
 562  *
 563  * PARAMETERS:  buffer          - Pointer to where the string is returned
 564  *              expected_btypes - Bitmap of expected return type(s)
 565  *
 566  * RETURN:      Buffer is populated with type names.
 567  *
 568  * DESCRIPTION: Translate the expected types bitmap into a string of ascii
 569  *              names of expected types, for use in warning messages.
 570  *
 571  ******************************************************************************/
 572
 573 static void acpi_ns_get_expected_types(char *buffer, u32 expected_btypes)
 574 {
 575         u32 this_rtype;
 576         u32 i;
 577         u32 j;
 578
 579         j = 1;
 580         buffer[0] = 0;
 581         this_rtype = ACPI_RTYPE_INTEGER;
 582
 583         for (i = 0; i < ACPI_NUM_RTYPES; i++) {
 584
 585                 /* If one of the expected types, concatenate the name of this type */
 586
 587                 if (expected_btypes & this_rtype) {
 588                         ACPI_STRCAT(buffer, &acpi_rtype_names[i][j]);
 589                         j = 0;  /* Use name separator from now on */
 590                 }
 591                 this_rtype <<= 1;       /* Next Rtype */
 592         }
 593 }