StandaloneMmPkg/Core/InstallConfigurationTable.c

   1 /** @file
   2   System Management System Table Services MmInstallConfigurationTable service
   3
   4   Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.<BR>
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include "StandaloneMmCore.h"
  11
  12 #define CONFIG_TABLE_SIZE_INCREASED 0x10
  13
  14 UINTN  mMmSystemTableAllocateSize = 0;
  15
  16 /**
  17   The MmInstallConfigurationTable() function is used to maintain the list
  18   of configuration tables that are stored in the System Management System
  19   Table.  The list is stored as an array of (GUID, Pointer) pairs.  The list
  20   must be allocated from pool memory with PoolType set to EfiRuntimeServicesData.
  21
  22   @param  SystemTable      A pointer to the SMM System Table (SMST).
  23   @param  Guid             A pointer to the GUID for the entry to add, update, or remove.
  24   @param  Table            A pointer to the buffer of the table to add.
  25   @param  TableSize        The size of the table to install.
  26
  27   @retval EFI_SUCCESS           The (Guid, Table) pair was added, updated, or removed.
  28   @retval EFI_INVALID_PARAMETER Guid is not valid.
  29   @retval EFI_NOT_FOUND         An attempt was made to delete a non-existent entry.
  30   @retval EFI_OUT_OF_RESOURCES  There is not enough memory available to complete the operation.
  31
  32 **/
  33 EFI_STATUS
  34 EFIAPI
  35 MmInstallConfigurationTable (
  36   IN  CONST EFI_MM_SYSTEM_TABLE    *SystemTable,
  37   IN  CONST EFI_GUID               *Guid,
  38   IN  VOID                         *Table,
  39   IN  UINTN                        TableSize
  40   )
  41 {
  42   UINTN                    Index;
  43   EFI_CONFIGURATION_TABLE  *ConfigurationTable;
  44   EFI_CONFIGURATION_TABLE  *OldTable;
  45
  46   //
  47   // If Guid is NULL, then this operation cannot be performed
  48   //
  49   if (Guid == NULL) {
  50     return EFI_INVALID_PARAMETER;
  51   }
  52
  53   ConfigurationTable = gMmCoreMmst.MmConfigurationTable;
  54
  55   //
  56   // Search all the table for an entry that matches Guid
  57   //
  58   for (Index = 0; Index < gMmCoreMmst.NumberOfTableEntries; Index++) {
  59     if (CompareGuid (Guid, &(ConfigurationTable[Index].VendorGuid))) {
  60       break;
  61     }
  62   }
  63
  64   if (Index < gMmCoreMmst.NumberOfTableEntries) {
  65     //
  66     // A match was found, so this is either a modify or a delete operation
  67     //
  68     if (Table != NULL) {
  69       //
  70       // If Table is not NULL, then this is a modify operation.
  71       // Modify the table entry and return.
  72       //
  73       ConfigurationTable[Index].VendorTable = Table;
  74       return EFI_SUCCESS;
  75     }
  76
  77     //
  78     // A match was found and Table is NULL, so this is a delete operation.
  79     //
  80     gMmCoreMmst.NumberOfTableEntries--;
  81
  82     //
  83     // Copy over deleted entry
  84     //
  85     CopyMem (
  86       &(ConfigurationTable[Index]),
  87       &(ConfigurationTable[Index + 1]),
  88       (gMmCoreMmst.NumberOfTableEntries - Index) * sizeof (EFI_CONFIGURATION_TABLE)
  89       );
  90
  91   } else {
  92     //
  93     // No matching GUIDs were found, so this is an add operation.
  94     //
  95     if (Table == NULL) {
  96       //
  97       // If Table is NULL on an add operation, then return an error.
  98       //
  99       return EFI_NOT_FOUND;
 100     }
 101
 102     //
 103     // Assume that Index == gMmCoreMmst.NumberOfTableEntries
 104     //
 105     if ((Index * sizeof (EFI_CONFIGURATION_TABLE)) >= mMmSystemTableAllocateSize) {
 106       //
 107       // Allocate a table with one additional entry.
 108       //
 109       mMmSystemTableAllocateSize += (CONFIG_TABLE_SIZE_INCREASED * sizeof (EFI_CONFIGURATION_TABLE));
 110       ConfigurationTable = AllocatePool (mMmSystemTableAllocateSize);
 111       if (ConfigurationTable == NULL) {
 112         //
 113         // If a new table could not be allocated, then return an error.
 114         //
 115         return EFI_OUT_OF_RESOURCES;
 116       }
 117
 118       if (gMmCoreMmst.MmConfigurationTable != NULL) {
 119         //
 120         // Copy the old table to the new table.
 121         //
 122         CopyMem (
 123           ConfigurationTable,
 124           gMmCoreMmst.MmConfigurationTable,
 125           Index * sizeof (EFI_CONFIGURATION_TABLE)
 126           );
 127
 128         //
 129         // Record the old table pointer.
 130         //
 131         OldTable = gMmCoreMmst.MmConfigurationTable;
 132
 133         //
 134         // As the MmInstallConfigurationTable() may be re-entered by FreePool() in
 135         // its calling stack, updating System table to the new table pointer must
 136         // be done before calling FreePool() to free the old table.
 137         // It can make sure the gMmCoreMmst.MmConfigurationTable point to the new
 138         // table and avoid the errors of use-after-free to the old table by the
 139         // reenter of MmInstallConfigurationTable() in FreePool()'s calling stack.
 140         //
 141         gMmCoreMmst.MmConfigurationTable = ConfigurationTable;
 142
 143         //
 144         // Free the old table after updating System Table to the new table pointer.
 145         //
 146         FreePool (OldTable);
 147       } else {
 148         //
 149         // Update System Table
 150         //
 151         gMmCoreMmst.MmConfigurationTable = ConfigurationTable;
 152       }
 153     }
 154
 155     //
 156     // Fill in the new entry
 157     //
 158     CopyGuid ((VOID *)&ConfigurationTable[Index].VendorGuid, Guid);
 159     ConfigurationTable[Index].VendorTable = Table;
 160
 161     //
 162     // This is an add operation, so increment the number of table entries
 163     //
 164     gMmCoreMmst.NumberOfTableEntries++;
 165   }
 166
 167   //
 168   // CRC-32 field is ignorable for SMM System Table and should be set to zero
 169   //
 170
 171   return EFI_SUCCESS;
 172 }