MdeModulePkg/Core/Dxe/Misc/InstallConfigurationTable.c

   1 /** @file
   2   UEFI Miscellaneous boot Services InstallConfigurationTable service
   3
   4 Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include "DxeMain.h"
  10
  11 #define CONFIG_TABLE_SIZE_INCREASED 0x10
  12
  13 UINTN mSystemTableAllocateSize = 0;
  14
  15 /**
  16   Boot Service called to add, modify, or remove a system configuration table from
  17   the EFI System Table.
  18
  19   @param  Guid           Pointer to the GUID for the entry to add, update, or
  20                          remove
  21   @param  Table          Pointer to the configuration table for the entry to add,
  22                          update, or remove, may be NULL.
  23
  24   @return EFI_SUCCESS               Guid, Table pair added, updated, or removed.
  25   @return EFI_INVALID_PARAMETER     Input GUID is NULL.
  26   @return EFI_NOT_FOUND             Attempted to delete non-existant entry
  27   @return EFI_OUT_OF_RESOURCES      Not enough memory available
  28
  29 **/
  30 EFI_STATUS
  31 EFIAPI
  32 CoreInstallConfigurationTable (
  33   IN EFI_GUID *Guid,
  34   IN VOID     *Table
  35   )
  36 {
  37   UINTN                   Index;
  38   EFI_CONFIGURATION_TABLE *EfiConfigurationTable;
  39   EFI_CONFIGURATION_TABLE *OldTable;
  40
  41   //
  42   // If Guid is NULL, then this operation cannot be performed
  43   //
  44   if (Guid == NULL) {
  45     return EFI_INVALID_PARAMETER;
  46   }
  47
  48   EfiConfigurationTable = gDxeCoreST->ConfigurationTable;
  49
  50   //
  51   // Search all the table for an entry that matches Guid
  52   //
  53   for (Index = 0; Index < gDxeCoreST->NumberOfTableEntries; Index++) {
  54     if (CompareGuid (Guid, &(gDxeCoreST->ConfigurationTable[Index].VendorGuid))) {
  55       break;
  56     }
  57   }
  58
  59   if (Index < gDxeCoreST->NumberOfTableEntries) {
  60     //
  61     // A match was found, so this is either a modify or a delete operation
  62     //
  63     if (Table != NULL) {
  64       //
  65       // If Table is not NULL, then this is a modify operation.
  66       // Modify the table entry and return.
  67       //
  68       gDxeCoreST->ConfigurationTable[Index].VendorTable = Table;
  69
  70       //
  71       // Signal Configuration Table change
  72       //
  73       CoreNotifySignalList (Guid);
  74
  75       return EFI_SUCCESS;
  76     }
  77
  78     //
  79     // A match was found and Table is NULL, so this is a delete operation.
  80     //
  81     gDxeCoreST->NumberOfTableEntries--;
  82
  83     //
  84     // Copy over deleted entry
  85     //
  86     CopyMem (
  87       &(EfiConfigurationTable[Index]),
  88       &(gDxeCoreST->ConfigurationTable[Index + 1]),
  89       (gDxeCoreST->NumberOfTableEntries - Index) * sizeof (EFI_CONFIGURATION_TABLE)
  90       );
  91
  92   } else {
  93
  94     //
  95     // No matching GUIDs were found, so this is an add operation.
  96     //
  97
  98     if (Table == NULL) {
  99       //
 100       // If Table is NULL on an add operation, then return an error.
 101       //
 102       return EFI_NOT_FOUND;
 103     }
 104
 105     //
 106     // Assume that Index == gDxeCoreST->NumberOfTableEntries
 107     //
 108     if ((Index * sizeof (EFI_CONFIGURATION_TABLE)) >= mSystemTableAllocateSize) {
 109       //
 110       // Allocate a table with one additional entry.
 111       //
 112       mSystemTableAllocateSize += (CONFIG_TABLE_SIZE_INCREASED * sizeof (EFI_CONFIGURATION_TABLE));
 113       EfiConfigurationTable = AllocateRuntimePool (mSystemTableAllocateSize);
 114       if (EfiConfigurationTable == NULL) {
 115         //
 116         // If a new table could not be allocated, then return an error.
 117         //
 118         return EFI_OUT_OF_RESOURCES;
 119       }
 120
 121       if (gDxeCoreST->ConfigurationTable != NULL) {
 122         //
 123         // Copy the old table to the new table.
 124         //
 125         CopyMem (
 126           EfiConfigurationTable,
 127           gDxeCoreST->ConfigurationTable,
 128           Index * sizeof (EFI_CONFIGURATION_TABLE)
 129           );
 130
 131         //
 132         // Record the old table pointer.
 133         //
 134         OldTable = gDxeCoreST->ConfigurationTable;
 135
 136         //
 137         // As the CoreInstallConfigurationTable() may be re-entered by CoreFreePool()
 138         // in its calling stack, updating System table to the new table pointer must
 139         // be done before calling CoreFreePool() to free the old table.
 140         // It can make sure the gDxeCoreST->ConfigurationTable point to the new table
 141         // and avoid the errors of use-after-free to the old table by the reenter of
 142         // CoreInstallConfigurationTable() in CoreFreePool()'s calling stack.
 143         //
 144         gDxeCoreST->ConfigurationTable = EfiConfigurationTable;
 145
 146         //
 147         // Free the old table after updating System Table to the new table pointer.
 148         //
 149         CoreFreePool (OldTable);
 150       } else {
 151         //
 152         // Update System Table
 153         //
 154         gDxeCoreST->ConfigurationTable = EfiConfigurationTable;
 155       }
 156     }
 157
 158     //
 159     // Fill in the new entry
 160     //
 161     CopyGuid ((VOID *)&EfiConfigurationTable[Index].VendorGuid, Guid);
 162     EfiConfigurationTable[Index].VendorTable  = Table;
 163
 164     //
 165     // This is an add operation, so increment the number of table entries
 166     //
 167     gDxeCoreST->NumberOfTableEntries++;
 168   }
 169
 170   //
 171   // Fix up the CRC-32 in the EFI System Table
 172   //
 173   CalculateEfiHdrCrc (&gDxeCoreST->Hdr);
 174
 175   //
 176   // Signal Configuration Table change
 177   //
 178   CoreNotifySignalList (Guid);
 179
 180   return EFI_SUCCESS;
 181 }