StandaloneMmPkg/Library/StandaloneMmMemLib/StandaloneMmMemLib.c

   1 /** @file
   2   Instance of MM memory check library.
   3
   4   MM memory check library library implementation. This library consumes MM_ACCESS_PROTOCOL
   5   to get MMRAM information. In order to use this library instance, the platform should produce
   6   all MMRAM range via MM_ACCESS_PROTOCOL, including the range for firmware (like MM Core
   7   and MM driver) and/or specific dedicated hardware.
   8
   9   Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
  10   Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.<BR>
  11
  12   This program and the accompanying materials
  13   are licensed and made available under the terms and conditions of the BSD License
  14   which accompanies this distribution.  The full text of the license may be found at
  15   http://opensource.org/licenses/bsd-license.php
  16
  17   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  18   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  19
  20 **/
  21
  22
  23 #include <PiMm.h>
  24
  25 #include <Library/BaseLib.h>
  26 #include <Library/BaseMemoryLib.h>
  27 #include <Library/DebugLib.h>
  28
  29 EFI_MMRAM_DESCRIPTOR *mMmMemLibInternalMmramRanges;
  30 UINTN                mMmMemLibInternalMmramCount;
  31
  32 //
  33 // Maximum support address used to check input buffer
  34 //
  35 EFI_PHYSICAL_ADDRESS  mMmMemLibInternalMaximumSupportAddress = 0;
  36
  37 /**
  38   Calculate and save the maximum support address.
  39
  40 **/
  41 VOID
  42 MmMemLibInternalCalculateMaximumSupportAddress (
  43   VOID
  44   );
  45
  46 /**
  47   This function check if the buffer is valid per processor architecture and not overlap with MMRAM.
  48
  49   @param Buffer  The buffer start address to be checked.
  50   @param Length  The buffer length to be checked.
  51
  52   @retval TRUE  This buffer is valid per processor architecture and not overlap with MMRAM.
  53   @retval FALSE This buffer is not valid per processor architecture or overlap with MMRAM.
  54 **/
  55 BOOLEAN
  56 EFIAPI
  57 MmIsBufferOutsideMmValid (
  58   IN EFI_PHYSICAL_ADDRESS  Buffer,
  59   IN UINT64                Length
  60   )
  61 {
  62   UINTN  Index;
  63
  64   //
  65   // Check override.
  66   // NOTE: (B:0->L:4G) is invalid for IA32, but (B:1->L:4G-1)/(B:4G-1->L:1) is valid.
  67   //
  68   if ((Length > mMmMemLibInternalMaximumSupportAddress) ||
  69       (Buffer > mMmMemLibInternalMaximumSupportAddress) ||
  70       ((Length != 0) && (Buffer > (mMmMemLibInternalMaximumSupportAddress - (Length - 1)))) ) {
  71     //
  72     // Overflow happen
  73     //
  74     DEBUG ((
  75       DEBUG_ERROR,
  76       "MmIsBufferOutsideMmValid: Overflow: Buffer (0x%lx) - Length (0x%lx), MaximumSupportAddress (0x%lx)\n",
  77       Buffer,
  78       Length,
  79       mMmMemLibInternalMaximumSupportAddress
  80       ));
  81     return FALSE;
  82   }
  83
  84   for (Index = 0; Index < mMmMemLibInternalMmramCount; Index ++) {
  85     if (((Buffer >= mMmMemLibInternalMmramRanges[Index].CpuStart) &&
  86          (Buffer < mMmMemLibInternalMmramRanges[Index].CpuStart + mMmMemLibInternalMmramRanges[Index].PhysicalSize)) ||
  87         ((mMmMemLibInternalMmramRanges[Index].CpuStart >= Buffer) &&
  88          (mMmMemLibInternalMmramRanges[Index].CpuStart < Buffer + Length))) {
  89       DEBUG ((
  90         DEBUG_ERROR,
  91         "MmIsBufferOutsideMmValid: Overlap: Buffer (0x%lx) - Length (0x%lx), ",
  92         Buffer,
  93         Length
  94         ));
  95       DEBUG ((
  96         DEBUG_ERROR,
  97         "CpuStart (0x%lx) - PhysicalSize (0x%lx)\n",
  98         mMmMemLibInternalMmramRanges[Index].CpuStart,
  99         mMmMemLibInternalMmramRanges[Index].PhysicalSize
 100         ));
 101       return FALSE;
 102     }
 103   }
 104
 105   return TRUE;
 106 }
 107
 108 /**
 109   Copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 110
 111   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 112   It checks if source buffer is valid per processor architecture and not overlap with MMRAM.
 113   If the check passes, it copies memory and returns EFI_SUCCESS.
 114   If the check fails, it return EFI_SECURITY_VIOLATION.
 115   The implementation must be reentrant.
 116
 117   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 118   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 119   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 120
 121   @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with MMRAM.
 122   @retval EFI_SUCCESS            Memory is copied.
 123
 124 **/
 125 EFI_STATUS
 126 EFIAPI
 127 MmCopyMemToMmram (
 128   OUT VOID       *DestinationBuffer,
 129   IN CONST VOID  *SourceBuffer,
 130   IN UINTN       Length
 131   )
 132 {
 133   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
 134     DEBUG ((DEBUG_ERROR, "MmCopyMemToMmram: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
 135     return EFI_SECURITY_VIOLATION;
 136   }
 137   CopyMem (DestinationBuffer, SourceBuffer, Length);
 138   return EFI_SUCCESS;
 139 }
 140
 141 /**
 142   Copies a source buffer (MMRAM) to a destination buffer (NON-MMRAM).
 143
 144   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 145   It checks if destination buffer is valid per processor architecture and not overlap with MMRAM.
 146   If the check passes, it copies memory and returns EFI_SUCCESS.
 147   If the check fails, it returns EFI_SECURITY_VIOLATION.
 148   The implementation must be reentrant.
 149
 150   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 151   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 152   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 153
 154   @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per processor architecture or overlap with MMRAM.
 155   @retval EFI_SUCCESS            Memory is copied.
 156
 157 **/
 158 EFI_STATUS
 159 EFIAPI
 160 MmCopyMemFromMmram (
 161   OUT VOID       *DestinationBuffer,
 162   IN CONST VOID  *SourceBuffer,
 163   IN UINTN       Length
 164   )
 165 {
 166   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
 167     DEBUG ((DEBUG_ERROR, "MmCopyMemFromMmram: Security Violation: Destination (0x%x), Length (0x%x)\n",
 168             DestinationBuffer, Length));
 169     return EFI_SECURITY_VIOLATION;
 170   }
 171   CopyMem (DestinationBuffer, SourceBuffer, Length);
 172   return EFI_SUCCESS;
 173 }
 174
 175 /**
 176   Copies a source buffer (NON-MMRAM) to a destination buffer (NON-MMRAM).
 177
 178   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 179   It checks if source buffer and destination buffer are valid per processor architecture and not overlap with MMRAM.
 180   If the check passes, it copies memory and returns EFI_SUCCESS.
 181   If the check fails, it returns EFI_SECURITY_VIOLATION.
 182   The implementation must be reentrant, and it must handle the case where source buffer overlaps destination buffer.
 183
 184   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 185   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 186   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 187
 188   @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per processor architecture or overlap with MMRAM.
 189   @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with MMRAM.
 190   @retval EFI_SUCCESS            Memory is copied.
 191
 192 **/
 193 EFI_STATUS
 194 EFIAPI
 195 MmCopyMem (
 196   OUT VOID       *DestinationBuffer,
 197   IN CONST VOID  *SourceBuffer,
 198   IN UINTN       Length
 199   )
 200 {
 201   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
 202     DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Destination (0x%x), Length (0x%x)\n",
 203             DestinationBuffer, Length));
 204     return EFI_SECURITY_VIOLATION;
 205   }
 206   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
 207     DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
 208     return EFI_SECURITY_VIOLATION;
 209   }
 210   CopyMem (DestinationBuffer, SourceBuffer, Length);
 211   return EFI_SUCCESS;
 212 }
 213
 214 /**
 215   Fills a target buffer (NON-MMRAM) with a byte value.
 216
 217   This function fills a target buffer (non-MMRAM) with a byte value.
 218   It checks if target buffer is valid per processor architecture and not overlap with MMRAM.
 219   If the check passes, it fills memory and returns EFI_SUCCESS.
 220   If the check fails, it returns EFI_SECURITY_VIOLATION.
 221
 222   @param  Buffer    The memory to set.
 223   @param  Length    The number of bytes to set.
 224   @param  Value     The value with which to fill Length bytes of Buffer.
 225
 226   @retval EFI_SECURITY_VIOLATION The Buffer is invalid per processor architecture or overlap with MMRAM.
 227   @retval EFI_SUCCESS            Memory is set.
 228
 229 **/
 230 EFI_STATUS
 231 EFIAPI
 232 MmSetMem (
 233   OUT VOID  *Buffer,
 234   IN UINTN  Length,
 235   IN UINT8  Value
 236   )
 237 {
 238   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, Length)) {
 239     DEBUG ((DEBUG_ERROR, "MmSetMem: Security Violation: Source (0x%x), Length (0x%x)\n", Buffer, Length));
 240     return EFI_SECURITY_VIOLATION;
 241   }
 242   SetMem (Buffer, Length, Value);
 243   return EFI_SUCCESS;
 244 }
 245
 246 /**
 247   The constructor function initializes the Mm Mem library
 248
 249   @param  ImageHandle   The firmware allocated handle for the EFI image.
 250   @param  SystemTable   A pointer to the EFI System Table.
 251
 252   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
 253
 254 **/
 255 EFI_STATUS
 256 EFIAPI
 257 MemLibConstructor (
 258   IN EFI_HANDLE             ImageHandle,
 259   IN EFI_MM_SYSTEM_TABLE    *MmSystemTable
 260   )
 261 {
 262
 263   //
 264   // Calculate and save maximum support address
 265   //
 266   MmMemLibInternalCalculateMaximumSupportAddress ();
 267
 268   return EFI_SUCCESS;
 269 }