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 - 2021, Arm Limited. All rights reserved.<BR>
  11
  12   SPDX-License-Identifier: BSD-2-Clause-Patent
  13
  14 **/
  15
  16
  17 #include <PiMm.h>
  18
  19 #include <Library/BaseLib.h>
  20 #include <Library/BaseMemoryLib.h>
  21 #include <Library/DebugLib.h>
  22
  23 EFI_MMRAM_DESCRIPTOR *mMmMemLibInternalMmramRanges;
  24 UINTN                mMmMemLibInternalMmramCount;
  25
  26 //
  27 // Maximum support address used to check input buffer
  28 //
  29 EFI_PHYSICAL_ADDRESS  mMmMemLibInternalMaximumSupportAddress = 0;
  30
  31 /**
  32   Calculate and save the maximum support address.
  33
  34 **/
  35 VOID
  36 MmMemLibInternalCalculateMaximumSupportAddress (
  37   VOID
  38   );
  39
  40 /**
  41   Initialize cached Mmram Ranges from HOB.
  42
  43   @retval EFI_UNSUPPORTED   The routine is unable to extract MMRAM information.
  44   @retval EFI_SUCCESS       MmRanges are populated successfully.
  45
  46 **/
  47 EFI_STATUS
  48 MmMemLibInternalPopulateMmramRanges (
  49   VOID
  50   );
  51
  52 /**
  53   Deinitialize cached Mmram Ranges.
  54
  55 **/
  56 VOID
  57 MmMemLibInternalFreeMmramRanges (
  58   VOID
  59   );
  60
  61 /**
  62   This function check if the buffer is valid per processor architecture and not overlap with MMRAM.
  63
  64   @param Buffer  The buffer start address to be checked.
  65   @param Length  The buffer length to be checked.
  66
  67   @retval TRUE  This buffer is valid per processor architecture and not overlap with MMRAM.
  68   @retval FALSE This buffer is not valid per processor architecture or overlap with MMRAM.
  69 **/
  70 BOOLEAN
  71 EFIAPI
  72 MmIsBufferOutsideMmValid (
  73   IN EFI_PHYSICAL_ADDRESS  Buffer,
  74   IN UINT64                Length
  75   )
  76 {
  77   UINTN  Index;
  78
  79   //
  80   // Check override.
  81   // NOTE: (B:0->L:4G) is invalid for IA32, but (B:1->L:4G-1)/(B:4G-1->L:1) is valid.
  82   //
  83   if ((Length > mMmMemLibInternalMaximumSupportAddress) ||
  84       (Buffer > mMmMemLibInternalMaximumSupportAddress) ||
  85       ((Length != 0) && (Buffer > (mMmMemLibInternalMaximumSupportAddress - (Length - 1)))) ) {
  86     //
  87     // Overflow happen
  88     //
  89     DEBUG ((
  90       DEBUG_ERROR,
  91       "MmIsBufferOutsideMmValid: Overflow: Buffer (0x%lx) - Length (0x%lx), MaximumSupportAddress (0x%lx)\n",
  92       Buffer,
  93       Length,
  94       mMmMemLibInternalMaximumSupportAddress
  95       ));
  96     return FALSE;
  97   }
  98
  99   for (Index = 0; Index < mMmMemLibInternalMmramCount; Index ++) {
 100     if (((Buffer >= mMmMemLibInternalMmramRanges[Index].CpuStart) &&
 101          (Buffer < mMmMemLibInternalMmramRanges[Index].CpuStart + mMmMemLibInternalMmramRanges[Index].PhysicalSize)) ||
 102         ((mMmMemLibInternalMmramRanges[Index].CpuStart >= Buffer) &&
 103          (mMmMemLibInternalMmramRanges[Index].CpuStart < Buffer + Length))) {
 104       DEBUG ((
 105         DEBUG_ERROR,
 106         "MmIsBufferOutsideMmValid: Overlap: Buffer (0x%lx) - Length (0x%lx), ",
 107         Buffer,
 108         Length
 109         ));
 110       DEBUG ((
 111         DEBUG_ERROR,
 112         "CpuStart (0x%lx) - PhysicalSize (0x%lx)\n",
 113         mMmMemLibInternalMmramRanges[Index].CpuStart,
 114         mMmMemLibInternalMmramRanges[Index].PhysicalSize
 115         ));
 116       return FALSE;
 117     }
 118   }
 119
 120   return TRUE;
 121 }
 122
 123 /**
 124   Copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 125
 126   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 127   It checks if source buffer is valid per processor architecture and not overlap with MMRAM.
 128   If the check passes, it copies memory and returns EFI_SUCCESS.
 129   If the check fails, it return EFI_SECURITY_VIOLATION.
 130   The implementation must be reentrant.
 131
 132   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 133   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 134   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 135
 136   @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with MMRAM.
 137   @retval EFI_SUCCESS            Memory is copied.
 138
 139 **/
 140 EFI_STATUS
 141 EFIAPI
 142 MmCopyMemToMmram (
 143   OUT VOID       *DestinationBuffer,
 144   IN CONST VOID  *SourceBuffer,
 145   IN UINTN       Length
 146   )
 147 {
 148   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
 149     DEBUG ((DEBUG_ERROR, "MmCopyMemToMmram: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
 150     return EFI_SECURITY_VIOLATION;
 151   }
 152   CopyMem (DestinationBuffer, SourceBuffer, Length);
 153   return EFI_SUCCESS;
 154 }
 155
 156 /**
 157   Copies a source buffer (MMRAM) to a destination buffer (NON-MMRAM).
 158
 159   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 160   It checks if destination buffer is valid per processor architecture and not overlap with MMRAM.
 161   If the check passes, it copies memory and returns EFI_SUCCESS.
 162   If the check fails, it returns EFI_SECURITY_VIOLATION.
 163   The implementation must be reentrant.
 164
 165   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 166   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 167   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 168
 169   @retval EFI_SECURITY_VIOLATION The DestinationBuffer is invalid per processor architecture or overlap with MMRAM.
 170   @retval EFI_SUCCESS            Memory is copied.
 171
 172 **/
 173 EFI_STATUS
 174 EFIAPI
 175 MmCopyMemFromMmram (
 176   OUT VOID       *DestinationBuffer,
 177   IN CONST VOID  *SourceBuffer,
 178   IN UINTN       Length
 179   )
 180 {
 181   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
 182     DEBUG ((DEBUG_ERROR, "MmCopyMemFromMmram: Security Violation: Destination (0x%x), Length (0x%x)\n",
 183             DestinationBuffer, Length));
 184     return EFI_SECURITY_VIOLATION;
 185   }
 186   CopyMem (DestinationBuffer, SourceBuffer, Length);
 187   return EFI_SUCCESS;
 188 }
 189
 190 /**
 191   Copies a source buffer (NON-MMRAM) to a destination buffer (NON-MMRAM).
 192
 193   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 194   It checks if source buffer and destination buffer are valid per processor architecture and not overlap with MMRAM.
 195   If the check passes, it copies memory and returns EFI_SUCCESS.
 196   If the check fails, it returns EFI_SECURITY_VIOLATION.
 197   The implementation must be reentrant, and it must handle the case where source buffer overlaps destination buffer.
 198
 199   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 200   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 201   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 202
 203   @retval EFI_SECURITY_VIOLATION The DestinationBuffer is invalid per processor architecture or overlap with MMRAM.
 204   @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with MMRAM.
 205   @retval EFI_SUCCESS            Memory is copied.
 206
 207 **/
 208 EFI_STATUS
 209 EFIAPI
 210 MmCopyMem (
 211   OUT VOID       *DestinationBuffer,
 212   IN CONST VOID  *SourceBuffer,
 213   IN UINTN       Length
 214   )
 215 {
 216   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
 217     DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Destination (0x%x), Length (0x%x)\n",
 218             DestinationBuffer, Length));
 219     return EFI_SECURITY_VIOLATION;
 220   }
 221   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
 222     DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
 223     return EFI_SECURITY_VIOLATION;
 224   }
 225   CopyMem (DestinationBuffer, SourceBuffer, Length);
 226   return EFI_SUCCESS;
 227 }
 228
 229 /**
 230   Fills a target buffer (NON-MMRAM) with a byte value.
 231
 232   This function fills a target buffer (non-MMRAM) with a byte value.
 233   It checks if target buffer is valid per processor architecture and not overlap with MMRAM.
 234   If the check passes, it fills memory and returns EFI_SUCCESS.
 235   If the check fails, it returns EFI_SECURITY_VIOLATION.
 236
 237   @param  Buffer    The memory to set.
 238   @param  Length    The number of bytes to set.
 239   @param  Value     The value with which to fill Length bytes of Buffer.
 240
 241   @retval EFI_SECURITY_VIOLATION The Buffer is invalid per processor architecture or overlap with MMRAM.
 242   @retval EFI_SUCCESS            Memory is set.
 243
 244 **/
 245 EFI_STATUS
 246 EFIAPI
 247 MmSetMem (
 248   OUT VOID  *Buffer,
 249   IN UINTN  Length,
 250   IN UINT8  Value
 251   )
 252 {
 253   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, Length)) {
 254     DEBUG ((DEBUG_ERROR, "MmSetMem: Security Violation: Source (0x%x), Length (0x%x)\n", Buffer, Length));
 255     return EFI_SECURITY_VIOLATION;
 256   }
 257   SetMem (Buffer, Length, Value);
 258   return EFI_SUCCESS;
 259 }
 260
 261 /**
 262   The constructor function initializes the Mm Mem library
 263
 264   @param  [in]  ImageHandle     The firmware allocated handle for the EFI image.
 265   @param  [in]  MmSystemTable   A pointer to the EFI System Table.
 266
 267   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
 268
 269 **/
 270 EFI_STATUS
 271 EFIAPI
 272 MemLibConstructor (
 273   IN EFI_HANDLE             ImageHandle,
 274   IN EFI_MM_SYSTEM_TABLE    *MmSystemTable
 275   )
 276 {
 277   EFI_STATUS Status;
 278
 279   //
 280   // Calculate and save maximum support address
 281   //
 282   MmMemLibInternalCalculateMaximumSupportAddress ();
 283
 284   //
 285   // Initialize cached Mmram Ranges from HOB.
 286   //
 287   Status = MmMemLibInternalPopulateMmramRanges ();
 288
 289   return Status;
 290 }
 291
 292 /**
 293   Destructor for Mm Mem library.
 294
 295   @param ImageHandle    The image handle of the process.
 296   @param MmSystemTable  The EFI System Table pointer.
 297
 298   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
 299
 300 **/
 301 EFI_STATUS
 302 EFIAPI
 303 MemLibDestructor (
 304   IN EFI_HANDLE             ImageHandle,
 305   IN EFI_MM_SYSTEM_TABLE    *MmSystemTable
 306   )
 307 {
 308
 309   //
 310   // Deinitialize cached Mmram Ranges.
 311   //
 312   MmMemLibInternalFreeMmramRanges ();
 313
 314   return EFI_SUCCESS;
 315 }