drivers/acpi/acpica/nsrepair.c

   1 /******************************************************************************
   2  *
   3  * Module Name: nsrepair - Repair for objects returned by predefined methods
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2009, 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 #include <acpi/acpi.h>
  45 #include "accommon.h"
  46 #include "acnamesp.h"
  47 #include "acpredef.h"
  48
  49 #define _COMPONENT          ACPI_NAMESPACE
  50 ACPI_MODULE_NAME("nsrepair")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ns_repair_object
  55  *
  56  * PARAMETERS:  Data                - Pointer to validation data structure
  57  *              expected_btypes     - Object types expected
  58  *              package_index       - Index of object within parent package (if
  59  *                                    applicable - ACPI_NOT_PACKAGE_ELEMENT
  60  *                                    otherwise)
  61  *              return_object_ptr   - Pointer to the object returned from the
  62  *                                    evaluation of a method or object
  63  *
  64  * RETURN:      Status. AE_OK if repair was successful.
  65  *
  66  * DESCRIPTION: Attempt to repair/convert a return object of a type that was
  67  *              not expected.
  68  *
  69  ******************************************************************************/
  70 acpi_status
  71 acpi_ns_repair_object(struct acpi_predefined_data *data,
  72                       u32 expected_btypes,
  73                       u32 package_index,
  74                       union acpi_operand_object **return_object_ptr)
  75 {
  76         union acpi_operand_object *return_object = *return_object_ptr;
  77         union acpi_operand_object *new_object;
  78         acpi_size length;
  79
  80         switch (return_object->common.type) {
  81         case ACPI_TYPE_BUFFER:
  82
  83                 /* Does the method/object legally return a string? */
  84
  85                 if (!(expected_btypes & ACPI_RTYPE_STRING)) {
  86                         return (AE_AML_OPERAND_TYPE);
  87                 }
  88
  89                 /*
  90                  * Have a Buffer, expected a String, convert. Use a to_string
  91                  * conversion, no transform performed on the buffer data. The best
  92                  * example of this is the _BIF method, where the string data from
  93                  * the battery is often (incorrectly) returned as buffer object(s).
  94                  */
  95                 length = 0;
  96                 while ((length < return_object->buffer.length) &&
  97                        (return_object->buffer.pointer[length])) {
  98                         length++;
  99                 }
 100
 101                 /* Allocate a new string object */
 102
 103                 new_object = acpi_ut_create_string_object(length);
 104                 if (!new_object) {
 105                         return (AE_NO_MEMORY);
 106                 }
 107
 108                 /*
 109                  * Copy the raw buffer data with no transform. String is already NULL
 110                  * terminated at Length+1.
 111                  */
 112                 ACPI_MEMCPY(new_object->string.pointer,
 113                             return_object->buffer.pointer, length);
 114
 115                 /*
 116                  * If the original object is a package element, we need to:
 117                  * 1. Set the reference count of the new object to match the
 118                  *    reference count of the old object.
 119                  * 2. Decrement the reference count of the original object.
 120                  */
 121                 if (package_index != ACPI_NOT_PACKAGE_ELEMENT) {
 122                         new_object->common.reference_count =
 123                             return_object->common.reference_count;
 124
 125                         if (return_object->common.reference_count > 1) {
 126                                 return_object->common.reference_count--;
 127                         }
 128
 129                         ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
 130                                               data->node_flags,
 131                                               "Converted Buffer to expected String at index %u",
 132                                               package_index));
 133                 } else {
 134                         ACPI_WARN_PREDEFINED((AE_INFO, data->pathname,
 135                                               data->node_flags,
 136                                               "Converted Buffer to expected String"));
 137                 }
 138
 139                 /* Delete old object, install the new return object */
 140
 141                 acpi_ut_remove_reference(return_object);
 142                 *return_object_ptr = new_object;
 143                 data->flags |= ACPI_OBJECT_REPAIRED;
 144                 return (AE_OK);
 145
 146         default:
 147                 break;
 148         }
 149
 150         return (AE_AML_OPERAND_TYPE);
 151 }