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   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   This function check if the buffer is valid per processor architecture and not overlap with MMRAM.
  42
  43   @param Buffer  The buffer start address to be checked.
  44   @param Length  The buffer length to be checked.
  45
  46   @retval TRUE  This buffer is valid per processor architecture and not overlap with MMRAM.
  47   @retval FALSE This buffer is not valid per processor architecture or overlap with MMRAM.
  48 **/
  49 BOOLEAN
  50 EFIAPI
  51 MmIsBufferOutsideMmValid (
  52   IN EFI_PHYSICAL_ADDRESS  Buffer,
  53   IN UINT64                Length
  54   )
  55 {
  56   UINTN  Index;
  57
  58   //
  59   // Check override.
  60   // NOTE: (B:0->L:4G) is invalid for IA32, but (B:1->L:4G-1)/(B:4G-1->L:1) is valid.
  61   //
  62   if ((Length > mMmMemLibInternalMaximumSupportAddress) ||
  63       (Buffer > mMmMemLibInternalMaximumSupportAddress) ||
  64       ((Length != 0) && (Buffer > (mMmMemLibInternalMaximumSupportAddress - (Length - 1)))) ) {
  65     //
  66     // Overflow happen
  67     //
  68     DEBUG ((
  69       DEBUG_ERROR,
  70       "MmIsBufferOutsideMmValid: Overflow: Buffer (0x%lx) - Length (0x%lx), MaximumSupportAddress (0x%lx)\n",
  71       Buffer,
  72       Length,
  73       mMmMemLibInternalMaximumSupportAddress
  74       ));
  75     return FALSE;
  76   }
  77
  78   for (Index = 0; Index < mMmMemLibInternalMmramCount; Index ++) {
  79     if (((Buffer >= mMmMemLibInternalMmramRanges[Index].CpuStart) &&
  80          (Buffer < mMmMemLibInternalMmramRanges[Index].CpuStart + mMmMemLibInternalMmramRanges[Index].PhysicalSize)) ||
  81         ((mMmMemLibInternalMmramRanges[Index].CpuStart >= Buffer) &&
  82          (mMmMemLibInternalMmramRanges[Index].CpuStart < Buffer + Length))) {
  83       DEBUG ((
  84         DEBUG_ERROR,
  85         "MmIsBufferOutsideMmValid: Overlap: Buffer (0x%lx) - Length (0x%lx), ",
  86         Buffer,
  87         Length
  88         ));
  89       DEBUG ((
  90         DEBUG_ERROR,
  91         "CpuStart (0x%lx) - PhysicalSize (0x%lx)\n",
  92         mMmMemLibInternalMmramRanges[Index].CpuStart,
  93         mMmMemLibInternalMmramRanges[Index].PhysicalSize
  94         ));
  95       return FALSE;
  96     }
  97   }
  98
  99   return TRUE;
 100 }
 101
 102 /**
 103   Copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 104
 105   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 106   It checks if source buffer is valid per processor architecture and not overlap with MMRAM.
 107   If the check passes, it copies memory and returns EFI_SUCCESS.
 108   If the check fails, it return EFI_SECURITY_VIOLATION.
 109   The implementation must be reentrant.
 110
 111   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 112   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 113   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 114
 115   @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with MMRAM.
 116   @retval EFI_SUCCESS            Memory is copied.
 117
 118 **/
 119 EFI_STATUS
 120 EFIAPI
 121 MmCopyMemToMmram (
 122   OUT VOID       *DestinationBuffer,
 123   IN CONST VOID  *SourceBuffer,
 124   IN UINTN       Length
 125   )
 126 {
 127   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
 128     DEBUG ((DEBUG_ERROR, "MmCopyMemToMmram: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
 129     return EFI_SECURITY_VIOLATION;
 130   }
 131   CopyMem (DestinationBuffer, SourceBuffer, Length);
 132   return EFI_SUCCESS;
 133 }
 134
 135 /**
 136   Copies a source buffer (MMRAM) to a destination buffer (NON-MMRAM).
 137
 138   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 139   It checks if destination buffer is valid per processor architecture and not overlap with MMRAM.
 140   If the check passes, it copies memory and returns EFI_SUCCESS.
 141   If the check fails, it returns EFI_SECURITY_VIOLATION.
 142   The implementation must be reentrant.
 143
 144   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 145   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 146   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 147
 148   @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per processor architecture or overlap with MMRAM.
 149   @retval EFI_SUCCESS            Memory is copied.
 150
 151 **/
 152 EFI_STATUS
 153 EFIAPI
 154 MmCopyMemFromMmram (
 155   OUT VOID       *DestinationBuffer,
 156   IN CONST VOID  *SourceBuffer,
 157   IN UINTN       Length
 158   )
 159 {
 160   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
 161     DEBUG ((DEBUG_ERROR, "MmCopyMemFromMmram: Security Violation: Destination (0x%x), Length (0x%x)\n",
 162             DestinationBuffer, Length));
 163     return EFI_SECURITY_VIOLATION;
 164   }
 165   CopyMem (DestinationBuffer, SourceBuffer, Length);
 166   return EFI_SUCCESS;
 167 }
 168
 169 /**
 170   Copies a source buffer (NON-MMRAM) to a destination buffer (NON-MMRAM).
 171
 172   This function copies a source buffer (non-MMRAM) to a destination buffer (MMRAM).
 173   It checks if source buffer and destination buffer are valid per processor architecture and not overlap with MMRAM.
 174   If the check passes, it copies memory and returns EFI_SUCCESS.
 175   If the check fails, it returns EFI_SECURITY_VIOLATION.
 176   The implementation must be reentrant, and it must handle the case where source buffer overlaps destination buffer.
 177
 178   @param  DestinationBuffer   The pointer to the destination buffer of the memory copy.
 179   @param  SourceBuffer        The pointer to the source buffer of the memory copy.
 180   @param  Length              The number of bytes to copy from SourceBuffer to DestinationBuffer.
 181
 182   @retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per processor architecture or overlap with MMRAM.
 183   @retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with MMRAM.
 184   @retval EFI_SUCCESS            Memory is copied.
 185
 186 **/
 187 EFI_STATUS
 188 EFIAPI
 189 MmCopyMem (
 190   OUT VOID       *DestinationBuffer,
 191   IN CONST VOID  *SourceBuffer,
 192   IN UINTN       Length
 193   )
 194 {
 195   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
 196     DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Destination (0x%x), Length (0x%x)\n",
 197             DestinationBuffer, Length));
 198     return EFI_SECURITY_VIOLATION;
 199   }
 200   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
 201     DEBUG ((DEBUG_ERROR, "MmCopyMem: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
 202     return EFI_SECURITY_VIOLATION;
 203   }
 204   CopyMem (DestinationBuffer, SourceBuffer, Length);
 205   return EFI_SUCCESS;
 206 }
 207
 208 /**
 209   Fills a target buffer (NON-MMRAM) with a byte value.
 210
 211   This function fills a target buffer (non-MMRAM) with a byte value.
 212   It checks if target buffer is valid per processor architecture and not overlap with MMRAM.
 213   If the check passes, it fills memory and returns EFI_SUCCESS.
 214   If the check fails, it returns EFI_SECURITY_VIOLATION.
 215
 216   @param  Buffer    The memory to set.
 217   @param  Length    The number of bytes to set.
 218   @param  Value     The value with which to fill Length bytes of Buffer.
 219
 220   @retval EFI_SECURITY_VIOLATION The Buffer is invalid per processor architecture or overlap with MMRAM.
 221   @retval EFI_SUCCESS            Memory is set.
 222
 223 **/
 224 EFI_STATUS
 225 EFIAPI
 226 MmSetMem (
 227   OUT VOID  *Buffer,
 228   IN UINTN  Length,
 229   IN UINT8  Value
 230   )
 231 {
 232   if (!MmIsBufferOutsideMmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, Length)) {
 233     DEBUG ((DEBUG_ERROR, "MmSetMem: Security Violation: Source (0x%x), Length (0x%x)\n", Buffer, Length));
 234     return EFI_SECURITY_VIOLATION;
 235   }
 236   SetMem (Buffer, Length, Value);
 237   return EFI_SUCCESS;
 238 }
 239
 240 /**
 241   The constructor function initializes the Mm Mem library
 242
 243   @param  ImageHandle   The firmware allocated handle for the EFI image.
 244   @param  SystemTable   A pointer to the EFI System Table.
 245
 246   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
 247
 248 **/
 249 EFI_STATUS
 250 EFIAPI
 251 MemLibConstructor (
 252   IN EFI_HANDLE             ImageHandle,
 253   IN EFI_MM_SYSTEM_TABLE    *MmSystemTable
 254   )
 255 {
 256
 257   //
 258   // Calculate and save maximum support address
 259   //
 260   MmMemLibInternalCalculateMaximumSupportAddress ();
 261
 262   return EFI_SUCCESS;
 263 }