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   UINTN             GuardPageAddress;
  95   UINTN             CpuIndex;
  96
  97   ASSERT (InterruptType == EXCEPT_IA32_PAGE_FAULT);
  98
  99   AcquireSpinLock (mPFLock);
 100
 101   PFAddress = AsmReadCr2 ();
 102
 103   //
 104   // If a page fault occurs in SMRAM range, it might be in a SMM stack guard page,
 105   // or SMM page protection violation.
 106   //
 107   if ((PFAddress >= mCpuHotPlugData.SmrrBase) &&
 108       (PFAddress < (mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize))) {
 109     CpuIndex = GetCpuIndex ();
 110     GuardPageAddress = (mSmmStackArrayBase + EFI_PAGE_SIZE + CpuIndex * mSmmStackSize);
 111     if ((FeaturePcdGet (PcdCpuSmmStackGuard)) &&
 112         (PFAddress >= GuardPageAddress) &&
 113         (PFAddress < (GuardPageAddress + EFI_PAGE_SIZE))) {
 114       DEBUG ((DEBUG_ERROR, "SMM stack overflow!\n"));
 115     } else {
 116       DEBUG ((DEBUG_ERROR, "SMM exception data - 0x%x(", SystemContext.SystemContextIa32->ExceptionData));
 117       DEBUG ((DEBUG_ERROR, "I:%x, R:%x, U:%x, W:%x, P:%x",
 118         (SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0,
 119         (SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_RSVD) != 0,
 120         (SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_US) != 0,
 121         (SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_WR) != 0,
 122         (SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_P) != 0
 123         ));
 124       DEBUG ((DEBUG_ERROR, ")\n"));
 125       if ((SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0) {
 126         DEBUG ((DEBUG_ERROR, "SMM exception at execution (0x%x)\n", PFAddress));
 127         DEBUG_CODE (
 128           DumpModuleInfoByIp (*(UINTN *)(UINTN)SystemContext.SystemContextIa32->Esp);
 129         );
 130       } else {
 131         DEBUG ((DEBUG_ERROR, "SMM exception at access (0x%x)\n", PFAddress));
 132         DEBUG_CODE (
 133           DumpModuleInfoByIp ((UINTN)SystemContext.SystemContextIa32->Eip);
 134         );
 135       }
 136     }
 137     CpuDeadLoop ();
 138   }
 139
 140   //
 141   // If a page fault occurs in SMM range
 142   //
 143   if ((PFAddress < mCpuHotPlugData.SmrrBase) ||
 144       (PFAddress >= mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize)) {
 145     if ((SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0) {
 146       DEBUG ((DEBUG_ERROR, "Code executed on IP(0x%x) out of SMM range after SMM is locked!\n", PFAddress));
 147       DEBUG_CODE (
 148         DumpModuleInfoByIp (*(UINTN *)(UINTN)SystemContext.SystemContextIa32->Esp);
 149       );
 150       CpuDeadLoop ();
 151     }
 152     if (IsSmmCommBufferForbiddenAddress (PFAddress)) {
 153       DEBUG ((DEBUG_ERROR, "Access SMM communication forbidden address (0x%x)!\n", PFAddress));
 154       DEBUG_CODE (
 155         DumpModuleInfoByIp ((UINTN)SystemContext.SystemContextIa32->Eip);
 156       );
 157       CpuDeadLoop ();
 158     }
 159   }
 160
 161   if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
 162     SmmProfilePFHandler (
 163       SystemContext.SystemContextIa32->Eip,
 164       SystemContext.SystemContextIa32->ExceptionData
 165       );
 166   } else {
 167     SmiDefaultPFHandler ();
 168   }
 169
 170   ReleaseSpinLock (mPFLock);
 171 }
 172
 173 /**
 174   This function sets memory attribute for page table.
 175 **/
 176 VOID
 177 SetPageTableAttributes (
 178   VOID
 179   )
 180 {
 181   UINTN                 Index2;
 182   UINTN                 Index3;
 183   UINT64                *L1PageTable;
 184   UINT64                *L2PageTable;
 185   UINT64                *L3PageTable;
 186   BOOLEAN               IsSplitted;
 187   BOOLEAN               PageTableSplitted;
 188
 189   DEBUG ((DEBUG_INFO, "SetPageTableAttributes\n"));
 190
 191   //
 192   // Disable write protection, because we need mark page table to be write protected.
 193   // We need *write* page table memory, to mark itself to be *read only*.
 194   //
 195   AsmWriteCr0 (AsmReadCr0() & ~CR0_WP);
 196
 197   do {
 198     DEBUG ((DEBUG_INFO, "Start...\n"));
 199     PageTableSplitted = FALSE;
 200
 201     L3PageTable = (UINT64 *)GetPageTableBase ();
 202
 203     SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L3PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 204     PageTableSplitted = (PageTableSplitted || IsSplitted);
 205
 206     for (Index3 = 0; Index3 < 4; Index3++) {
 207       L2PageTable = (UINT64 *)(UINTN)(L3PageTable[Index3] & PAGING_4K_ADDRESS_MASK_64);
 208       if (L2PageTable == NULL) {
 209         continue;
 210       }
 211
 212       SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L2PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 213       PageTableSplitted = (PageTableSplitted || IsSplitted);
 214
 215       for (Index2 = 0; Index2 < SIZE_4KB/sizeof(UINT64); Index2++) {
 216         if ((L2PageTable[Index2] & IA32_PG_PS) != 0) {
 217           // 2M
 218           continue;
 219         }
 220         L1PageTable = (UINT64 *)(UINTN)(L2PageTable[Index2] & PAGING_4K_ADDRESS_MASK_64);
 221         if (L1PageTable == NULL) {
 222           continue;
 223         }
 224         SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L1PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
 225         PageTableSplitted = (PageTableSplitted || IsSplitted);
 226       }
 227     }
 228   } while (PageTableSplitted);
 229
 230   //
 231   // Enable write protection, after page table updated.
 232   //
 233   AsmWriteCr0 (AsmReadCr0() | CR0_WP);
 234
 235   return ;
 236 }