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   EFI_STATUS                        Status;
  31
  32   //
  33   // Initialize spin lock
  34   //
  35   InitializeSpinLock (mPFLock);
  36
  37   if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
  38     //
  39     // Set own Page Fault entry instead of the default one, because SMM Profile
  40     // feature depends on IRET instruction to do Single Step
  41     //
  42     PageFaultHandlerHookAddress = (UINTN)PageFaultIdtHandlerSmmProfile;
  43     IdtEntry  = (IA32_IDT_GATE_DESCRIPTOR *) gcSmiIdtr.Base;
  44     IdtEntry += EXCEPT_IA32_PAGE_FAULT;
  45     IdtEntry->Bits.OffsetLow      = (UINT16)PageFaultHandlerHookAddress;
  46     IdtEntry->Bits.Reserved_0     = 0;
  47     IdtEntry->Bits.GateType       = IA32_IDT_GATE_TYPE_INTERRUPT_32;
  48     IdtEntry->Bits.OffsetHigh     = (UINT16)(PageFaultHandlerHookAddress >> 16);
  49   } else {
  50     //
  51     // Register SMM Page Fault Handler
  52     //
  53     Status = SmmRegisterExceptionHandler (&mSmmCpuService, EXCEPT_IA32_PAGE_FAULT, SmiPFHandler);
  54     ASSERT_EFI_ERROR (Status);
  55   }
  56
  57   //
  58   // Additional SMM IDT initialization for SMM stack guard
  59   //
  60   if (FeaturePcdGet (PcdCpuSmmStackGuard)) {
  61     InitializeIDTSmmStackGuard ();
  62   }
  63   return Gen4GPageTable (TRUE);
  64 }
  65
  66 /**
  67   Page Fault handler for SMM use.
  68
  69 **/
  70 VOID
  71 SmiDefaultPFHandler (
  72   VOID
  73   )
  74 {
  75   CpuDeadLoop ();
  76 }
  77
  78 /**
  79   ThePage Fault handler wrapper for SMM use.
  80
  81   @param  InterruptType    Defines the type of interrupt or exception that
  82                            occurred on the processor.This parameter is processor architecture specific.
  83   @param  SystemContext    A pointer to the processor context when
  84                            the interrupt occurred on the processor.
  85 **/
  86 VOID
  87 EFIAPI
  88 SmiPFHandler (
  89     IN EFI_EXCEPTION_TYPE   InterruptType,
  90     IN EFI_SYSTEM_CONTEXT   SystemContext
  91   )
  92 {
  93   UINTN             PFAddress;
  94
  95   ASSERT (InterruptType == EXCEPT_IA32_PAGE_FAULT);
  96
  97   AcquireSpinLock (mPFLock);
  98
  99   PFAddress = AsmReadCr2 ();
 100
 101   if ((FeaturePcdGet (PcdCpuSmmStackGuard)) &&
 102       (PFAddress >= mCpuHotPlugData.SmrrBase) &&
 103       (PFAddress < (mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize))) {
 104     DEBUG ((DEBUG_ERROR, "SMM stack overflow!\n"));
 105     CpuDeadLoop ();
 106   }
 107
 108   //
 109   // If a page fault occurs in SMM range
 110   //
 111   if ((PFAddress < mCpuHotPlugData.SmrrBase) ||
 112       (PFAddress >= mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize)) {
 113     if ((SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0) {
 114       DEBUG ((DEBUG_ERROR, "Code executed on IP(0x%x) out of SMM range after SMM is locked!\n", PFAddress));
 115       DEBUG_CODE (
 116         DumpModuleInfoByIp (*(UINTN *)(UINTN)SystemContext.SystemContextIa32->Esp);
 117       );
 118       CpuDeadLoop ();
 119     }
 120   }
 121
 122   if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
 123     SmmProfilePFHandler (
 124       SystemContext.SystemContextIa32->Eip,
 125       SystemContext.SystemContextIa32->ExceptionData
 126       );
 127   } else {
 128     SmiDefaultPFHandler ();
 129   }
 130
 131   ReleaseSpinLock (mPFLock);
 132 }
 133
 134 /**
 135   This function sets memory attribute for page table.
 136 **/
 137 VOID
 138 SetPageTableAttributes (
 139   VOID
 140   )
 141 {
 142   UINTN                 Index2;
 143   UINTN                 Index3;
 144   UINT64                *L1PageTable;
 145   UINT64                *L2PageTable;
 146   UINT64                *L3PageTable;
 147   BOOLEAN               IsSplitted;
 148   BOOLEAN               PageTableSplitted;
 149
 150   DEBUG ((DEBUG_INFO, "SetPageTableAttributes\n"));
 151
 152   //
 153   // Disable write protection, because we need mark page table to be write protected.
 154   // We need *write* page table memory, to mark itself to be *read only*.
 155   //
 156   AsmWriteCr0 (AsmReadCr0() & ~CR0_WP);
 157
 158   do {
 159     DEBUG ((DEBUG_INFO, "Start...\n"));
 160     PageTableSplitted = FALSE;
 161
 162     L3PageTable = (UINT64 *)GetPageTableBase ();
 163
 164     SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L3PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 165     PageTableSplitted = (PageTableSplitted || IsSplitted);
 166
 167     for (Index3 = 0; Index3 < 4; Index3++) {
 168       L2PageTable = (UINT64 *)(UINTN)(L3PageTable[Index3] & PAGING_4K_ADDRESS_MASK_64);
 169       if (L2PageTable == NULL) {
 170         continue;
 171       }
 172
 173       SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L2PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 174       PageTableSplitted = (PageTableSplitted || IsSplitted);
 175
 176       for (Index2 = 0; Index2 < SIZE_4KB/sizeof(UINT64); Index2++) {
 177         if ((L2PageTable[Index2] & IA32_PG_PS) != 0) {
 178           // 2M
 179           continue;
 180         }
 181         L1PageTable = (UINT64 *)(UINTN)(L2PageTable[Index2] & PAGING_4K_ADDRESS_MASK_64);
 182         if (L1PageTable == NULL) {
 183           continue;
 184         }
 185         SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L1PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 186         PageTableSplitted = (PageTableSplitted || IsSplitted);
 187       }
 188     }
 189   } while (PageTableSplitted);
 190
 191   //
 192   // Enable write protection, after page table updated.
 193   //
 194   AsmWriteCr0 (AsmReadCr0() | CR0_WP);
 195
 196   return ;
 197 }