UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/PageTbl.c

   1 /** @file
   2 Page table manipulation functions for IA-32 processors
   3
   4 Copyright (c) 2009 - 2016, Intel Corporation. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "PiSmmCpuDxeSmm.h"
  16
  17 /**
  18   Create PageTable for SMM use.
  19
  20   @return     PageTable Address
  21
  22 **/
  23 UINT32
  24 SmmInitPageTable (
  25   VOID
  26   )
  27 {
  28   UINTN                             PageFaultHandlerHookAddress;
  29   IA32_IDT_GATE_DESCRIPTOR          *IdtEntry;
  30
  31   //
  32   // Initialize spin lock
  33   //
  34   InitializeSpinLock (mPFLock);
  35
  36   if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
  37     //
  38     // Set own Page Fault entry instead of the default one, because SMM Profile
  39     // feature depends on IRET instruction to do Single Step
  40     //
  41     PageFaultHandlerHookAddress = (UINTN)PageFaultIdtHandlerSmmProfile;
  42     IdtEntry  = (IA32_IDT_GATE_DESCRIPTOR *) gcSmiIdtr.Base;
  43     IdtEntry += EXCEPT_IA32_PAGE_FAULT;
  44     IdtEntry->Bits.OffsetLow      = (UINT16)PageFaultHandlerHookAddress;
  45     IdtEntry->Bits.Reserved_0     = 0;
  46     IdtEntry->Bits.GateType       = IA32_IDT_GATE_TYPE_INTERRUPT_32;
  47     IdtEntry->Bits.OffsetHigh     = (UINT16)(PageFaultHandlerHookAddress >> 16);
  48   } else {
  49     //
  50     // Register SMM Page Fault Handler
  51     //
  52     SmmRegisterExceptionHandler (&mSmmCpuService, EXCEPT_IA32_PAGE_FAULT, SmiPFHandler);
  53   }
  54
  55   //
  56   // Additional SMM IDT initialization for SMM stack guard
  57   //
  58   if (FeaturePcdGet (PcdCpuSmmStackGuard)) {
  59     InitializeIDTSmmStackGuard ();
  60   }
  61   return Gen4GPageTable (TRUE);
  62 }
  63
  64 /**
  65   Page Fault handler for SMM use.
  66
  67 **/
  68 VOID
  69 SmiDefaultPFHandler (
  70   VOID
  71   )
  72 {
  73   CpuDeadLoop ();
  74 }
  75
  76 /**
  77   ThePage Fault handler wrapper for SMM use.
  78
  79   @param  InterruptType    Defines the type of interrupt or exception that
  80                            occurred on the processor.This parameter is processor architecture specific.
  81   @param  SystemContext    A pointer to the processor context when
  82                            the interrupt occurred on the processor.
  83 **/
  84 VOID
  85 EFIAPI
  86 SmiPFHandler (
  87     IN EFI_EXCEPTION_TYPE   InterruptType,
  88     IN EFI_SYSTEM_CONTEXT   SystemContext
  89   )
  90 {
  91   UINTN             PFAddress;
  92
  93   ASSERT (InterruptType == EXCEPT_IA32_PAGE_FAULT);
  94
  95   AcquireSpinLock (mPFLock);
  96
  97   PFAddress = AsmReadCr2 ();
  98
  99   if ((FeaturePcdGet (PcdCpuSmmStackGuard)) &&
 100       (PFAddress >= mCpuHotPlugData.SmrrBase) &&
 101       (PFAddress < (mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize))) {
 102     DEBUG ((DEBUG_ERROR, "SMM stack overflow!\n"));
 103     CpuDeadLoop ();
 104   }
 105
 106   //
 107   // If a page fault occurs in SMM range
 108   //
 109   if ((PFAddress < mCpuHotPlugData.SmrrBase) ||
 110       (PFAddress >= mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize)) {
 111     if ((SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0) {
 112       DEBUG ((DEBUG_ERROR, "Code executed on IP(0x%x) out of SMM range after SMM is locked!\n", PFAddress));
 113       DEBUG_CODE (
 114         DumpModuleInfoByIp (*(UINTN *)(UINTN)SystemContext.SystemContextIa32->Esp);
 115       );
 116       CpuDeadLoop ();
 117     }
 118   }
 119
 120   if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
 121     SmmProfilePFHandler (
 122       SystemContext.SystemContextIa32->Eip,
 123       SystemContext.SystemContextIa32->ExceptionData
 124       );
 125   } else {
 126     SmiDefaultPFHandler ();
 127   }
 128
 129   ReleaseSpinLock (mPFLock);
 130 }
 131
 132 /**
 133   This function sets memory attribute for page table.
 134 **/
 135 VOID
 136 SetPageTableAttributes (
 137   VOID
 138   )
 139 {
 140   UINTN                 Index2;
 141   UINTN                 Index3;
 142   UINT64                *L1PageTable;
 143   UINT64                *L2PageTable;
 144   UINT64                *L3PageTable;
 145   BOOLEAN               IsSplitted;
 146   BOOLEAN               PageTableSplitted;
 147
 148   DEBUG ((DEBUG_INFO, "SetPageTableAttributes\n"));
 149
 150   //
 151   // Disable write protection, because we need mark page table to be write protected.
 152   // We need *write* page table memory, to mark itself to be *read only*.
 153   //
 154   AsmWriteCr0 (AsmReadCr0() & ~CR0_WP);
 155
 156   do {
 157     DEBUG ((DEBUG_INFO, "Start...\n"));
 158     PageTableSplitted = FALSE;
 159
 160     L3PageTable = (UINT64 *)GetPageTableBase ();
 161
 162     SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L3PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 163     PageTableSplitted = (PageTableSplitted || IsSplitted);
 164
 165     for (Index3 = 0; Index3 < 4; Index3++) {
 166       L2PageTable = (UINT64 *)(UINTN)(L3PageTable[Index3] & PAGING_4K_ADDRESS_MASK_64);
 167       if (L2PageTable == NULL) {
 168         continue;
 169       }
 170
 171       SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L2PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 172       PageTableSplitted = (PageTableSplitted || IsSplitted);
 173
 174       for (Index2 = 0; Index2 < SIZE_4KB/sizeof(UINT64); Index2++) {
 175         if ((L2PageTable[Index2] & IA32_PG_PS) != 0) {
 176           // 2M
 177           continue;
 178         }
 179         L1PageTable = (UINT64 *)(UINTN)(L2PageTable[Index2] & PAGING_4K_ADDRESS_MASK_64);
 180         if (L1PageTable == NULL) {
 181           continue;
 182         }
 183         SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L1PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 184         PageTableSplitted = (PageTableSplitted || IsSplitted);
 185       }
 186     }
 187   } while (PageTableSplitted);
 188
 189   //
 190   // Enable write protection, after page table updated.
 191   //
 192   AsmWriteCr0 (AsmReadCr0() | CR0_WP);
 193
 194   return ;
 195 }