InstallConfigurationTable.c

Go to the documentation of this file.

 
#include "PiSmmCore.h"
 
#define CONFIG_TABLE_SIZE_INCREASED  0x10
 
UINTN  mSmmSystemTableAllocateSize = 0;
 
EFI_STATUS
EFIAPI
SmmInstallConfigurationTable (
  IN  CONST EFI_SMM_SYSTEM_TABLE2  *SystemTable,
  IN  CONST EFI_GUID               *Guid,
  IN  VOID                         *Table,
  IN  UINTN                        TableSize
  )
{
  UINTN                    Index;
  EFI_CONFIGURATION_TABLE  *ConfigurationTable;
  EFI_CONFIGURATION_TABLE  *OldTable;
 
  //
  // If Guid is NULL, then this operation cannot be performed
  //
  if (Guid == NULL) {
    return EFI_INVALID_PARAMETER;
  }
 
  ConfigurationTable = gSmmCoreSmst.SmmConfigurationTable;
 
  //
  // Search all the table for an entry that matches Guid
  //
  for (Index = 0; Index < gSmmCoreSmst.NumberOfTableEntries; Index++) {
    if (CompareGuid (Guid, &(ConfigurationTable[Index].VendorGuid))) {
      break;
    }
  }
 
  if (Index < gSmmCoreSmst.NumberOfTableEntries) {
    //
    // A match was found, so this is either a modify or a delete operation
    //
    if (Table != NULL) {
      //
      // If Table is not NULL, then this is a modify operation.
      // Modify the table entry and return.
      //
      ConfigurationTable[Index].VendorTable = Table;
      return EFI_SUCCESS;
    }
 
    //
    // A match was found and Table is NULL, so this is a delete operation.
    //
    gSmmCoreSmst.NumberOfTableEntries--;
 
    //
    // Copy over deleted entry
    //
    CopyMem (
      &(ConfigurationTable[Index]),
      &(ConfigurationTable[Index + 1]),
      (gSmmCoreSmst.NumberOfTableEntries - Index) * sizeof (EFI_CONFIGURATION_TABLE)
      );
  } else {
    //
    // No matching GUIDs were found, so this is an add operation.
    //
    if (Table == NULL) {
      //
      // If Table is NULL on an add operation, then return an error.
      //
      return EFI_NOT_FOUND;
    }
 
    //
    // Assume that Index == gSmmCoreSmst.NumberOfTableEntries
    //
    if ((Index * sizeof (EFI_CONFIGURATION_TABLE)) >= mSmmSystemTableAllocateSize) {
      //
      // Allocate a table with one additional entry.
      //
      mSmmSystemTableAllocateSize += (CONFIG_TABLE_SIZE_INCREASED * sizeof (EFI_CONFIGURATION_TABLE));
      ConfigurationTable           = AllocatePool (mSmmSystemTableAllocateSize);
      if (ConfigurationTable == NULL) {
        //
        // If a new table could not be allocated, then return an error.
        //
        return EFI_OUT_OF_RESOURCES;
      }
 
      if (gSmmCoreSmst.SmmConfigurationTable != NULL) {
        //
        // Copy the old table to the new table.
        //
        CopyMem (
          ConfigurationTable,
          gSmmCoreSmst.SmmConfigurationTable,
          Index * sizeof (EFI_CONFIGURATION_TABLE)
          );
 
        //
        // Record the old table pointer.
        //
        OldTable = gSmmCoreSmst.SmmConfigurationTable;
 
        //
        // As the SmmInstallConfigurationTable() may be re-entered by FreePool() in
        // its calling stack, updating System table to the new table pointer must
        // be done before calling FreePool() to free the old table.
        // It can make sure the gSmmCoreSmst.SmmConfigurationTable point to the new
        // table and avoid the errors of use-after-free to the old table by the
        // reenter of SmmInstallConfigurationTable() in FreePool()'s calling stack.
        //
        gSmmCoreSmst.SmmConfigurationTable = ConfigurationTable;
 
        //
        // Free the old table after updating System Table to the new table pointer.
        //
        FreePool (OldTable);
      } else {
        //
        // Update System Table
        //
        gSmmCoreSmst.SmmConfigurationTable = ConfigurationTable;
      }
    }
 
    //
    // Fill in the new entry
    //
    CopyGuid ((VOID *)&ConfigurationTable[Index].VendorGuid, Guid);
    ConfigurationTable[Index].VendorTable = Table;
 
    //
    // This is an add operation, so increment the number of table entries
    //
    gSmmCoreSmst.NumberOfTableEntries++;
  }
 
  //
  // CRC-32 field is ignorable for SMM System Table and should be set to zero
  //
 
  return EFI_SUCCESS;
}