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   } else {
  92     //
  93     // No matching GUIDs were found, so this is an add operation.
  94     //
  95
  96     if (Table == NULL) {
  97       //
  98       // If Table is NULL on an add operation, then return an error.
  99       //
 100       return EFI_NOT_FOUND;
 101     }
 102
 103     //
 104     // Assume that Index == gDxeCoreST->NumberOfTableEntries
 105     //
 106     if ((Index * sizeof (EFI_CONFIGURATION_TABLE)) >= mSystemTableAllocateSize) {
 107       //
 108       // Allocate a table with one additional entry.
 109       //
 110       mSystemTableAllocateSize += (CONFIG_TABLE_SIZE_INCREASED * sizeof (EFI_CONFIGURATION_TABLE));
 111       EfiConfigurationTable     = AllocateRuntimePool (mSystemTableAllocateSize);
 112       if (EfiConfigurationTable == NULL) {
 113         //
 114         // If a new table could not be allocated, then return an error.
 115         //
 116         return EFI_OUT_OF_RESOURCES;
 117       }
 118
 119       if (gDxeCoreST->ConfigurationTable != NULL) {
 120         //
 121         // Copy the old table to the new table.
 122         //
 123         CopyMem (
 124           EfiConfigurationTable,
 125           gDxeCoreST->ConfigurationTable,
 126           Index * sizeof (EFI_CONFIGURATION_TABLE)
 127           );
 128
 129         //
 130         // Record the old table pointer.
 131         //
 132         OldTable = gDxeCoreST->ConfigurationTable;
 133
 134         //
 135         // As the CoreInstallConfigurationTable() may be re-entered by CoreFreePool()
 136         // in its calling stack, updating System table to the new table pointer must
 137         // be done before calling CoreFreePool() to free the old table.
 138         // It can make sure the gDxeCoreST->ConfigurationTable point to the new table
 139         // and avoid the errors of use-after-free to the old table by the reenter of
 140         // CoreInstallConfigurationTable() in CoreFreePool()'s calling stack.
 141         //
 142         gDxeCoreST->ConfigurationTable = EfiConfigurationTable;
 143
 144         //
 145         // Free the old table after updating System Table to the new table pointer.
 146         //
 147         CoreFreePool (OldTable);
 148       } else {
 149         //
 150         // Update System Table
 151         //
 152         gDxeCoreST->ConfigurationTable = EfiConfigurationTable;
 153       }
 154     }
 155
 156     //
 157     // Fill in the new entry
 158     //
 159     CopyGuid ((VOID *)&EfiConfigurationTable[Index].VendorGuid, Guid);
 160     EfiConfigurationTable[Index].VendorTable = Table;
 161
 162     //
 163     // This is an add operation, so increment the number of table entries
 164     //
 165     gDxeCoreST->NumberOfTableEntries++;
 166   }
 167
 168   //
 169   // Fix up the CRC-32 in the EFI System Table
 170   //
 171   CalculateEfiHdrCrc (&gDxeCoreST->Hdr);
 172
 173   //
 174   // Signal Configuration Table change
 175   //
 176   CoreNotifySignalList (Guid);
 177
 178   return EFI_SUCCESS;
 179 }