| 1 | /** @file |
| 2 | UEFI Heap Guard functions. |
| 3 | |
| 4 | Copyright (c) 2017, 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 "HeapGuard.h" |
| 16 | |
| 17 | // |
| 18 | // Global to avoid infinite reentrance of memory allocation when updating |
| 19 | // page table attributes, which may need allocating pages for new PDE/PTE. |
| 20 | // |
| 21 | GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN mOnGuarding = FALSE; |
| 22 | |
| 23 | // |
| 24 | // Pointer to table tracking the Guarded memory with bitmap, in which '1' |
| 25 | // is used to indicate memory guarded. '0' might be free memory or Guard |
| 26 | // page itself, depending on status of memory adjacent to it. |
| 27 | // |
| 28 | GLOBAL_REMOVE_IF_UNREFERENCED UINT64 mGuardedMemoryMap = 0; |
| 29 | |
| 30 | // |
| 31 | // Current depth level of map table pointed by mGuardedMemoryMap. |
| 32 | // mMapLevel must be initialized at least by 1. It will be automatically |
| 33 | // updated according to the address of memory just tracked. |
| 34 | // |
| 35 | GLOBAL_REMOVE_IF_UNREFERENCED UINTN mMapLevel = 1; |
| 36 | |
| 37 | // |
| 38 | // Shift and mask for each level of map table |
| 39 | // |
| 40 | GLOBAL_REMOVE_IF_UNREFERENCED UINTN mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH] |
| 41 | = GUARDED_HEAP_MAP_TABLE_DEPTH_SHIFTS; |
| 42 | GLOBAL_REMOVE_IF_UNREFERENCED UINTN mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH] |
| 43 | = GUARDED_HEAP_MAP_TABLE_DEPTH_MASKS; |
| 44 | |
| 45 | // |
| 46 | // SMM memory attribute protocol |
| 47 | // |
| 48 | EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL *mSmmMemoryAttribute = NULL; |
| 49 | |
| 50 | /** |
| 51 | Set corresponding bits in bitmap table to 1 according to the address. |
| 52 | |
| 53 | @param[in] Address Start address to set for. |
| 54 | @param[in] BitNumber Number of bits to set. |
| 55 | @param[in] BitMap Pointer to bitmap which covers the Address. |
| 56 | |
| 57 | @return VOID |
| 58 | **/ |
| 59 | STATIC |
| 60 | VOID |
| 61 | SetBits ( |
| 62 | IN EFI_PHYSICAL_ADDRESS Address, |
| 63 | IN UINTN BitNumber, |
| 64 | IN UINT64 *BitMap |
| 65 | ) |
| 66 | { |
| 67 | UINTN Lsbs; |
| 68 | UINTN Qwords; |
| 69 | UINTN Msbs; |
| 70 | UINTN StartBit; |
| 71 | UINTN EndBit; |
| 72 | |
| 73 | StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address); |
| 74 | EndBit = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS; |
| 75 | |
| 76 | if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) { |
| 77 | Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) % |
| 78 | GUARDED_HEAP_MAP_ENTRY_BITS; |
| 79 | Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS; |
| 80 | Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS; |
| 81 | } else { |
| 82 | Msbs = BitNumber; |
| 83 | Lsbs = 0; |
| 84 | Qwords = 0; |
| 85 | } |
| 86 | |
| 87 | if (Msbs > 0) { |
| 88 | *BitMap |= LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit); |
| 89 | BitMap += 1; |
| 90 | } |
| 91 | |
| 92 | if (Qwords > 0) { |
| 93 | SetMem64 ((VOID *)BitMap, Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES, |
| 94 | (UINT64)-1); |
| 95 | BitMap += Qwords; |
| 96 | } |
| 97 | |
| 98 | if (Lsbs > 0) { |
| 99 | *BitMap |= (LShiftU64 (1, Lsbs) - 1); |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | Set corresponding bits in bitmap table to 0 according to the address. |
| 105 | |
| 106 | @param[in] Address Start address to set for. |
| 107 | @param[in] BitNumber Number of bits to set. |
| 108 | @param[in] BitMap Pointer to bitmap which covers the Address. |
| 109 | |
| 110 | @return VOID. |
| 111 | **/ |
| 112 | STATIC |
| 113 | VOID |
| 114 | ClearBits ( |
| 115 | IN EFI_PHYSICAL_ADDRESS Address, |
| 116 | IN UINTN BitNumber, |
| 117 | IN UINT64 *BitMap |
| 118 | ) |
| 119 | { |
| 120 | UINTN Lsbs; |
| 121 | UINTN Qwords; |
| 122 | UINTN Msbs; |
| 123 | UINTN StartBit; |
| 124 | UINTN EndBit; |
| 125 | |
| 126 | StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address); |
| 127 | EndBit = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS; |
| 128 | |
| 129 | if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) { |
| 130 | Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) % |
| 131 | GUARDED_HEAP_MAP_ENTRY_BITS; |
| 132 | Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS; |
| 133 | Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS; |
| 134 | } else { |
| 135 | Msbs = BitNumber; |
| 136 | Lsbs = 0; |
| 137 | Qwords = 0; |
| 138 | } |
| 139 | |
| 140 | if (Msbs > 0) { |
| 141 | *BitMap &= ~LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit); |
| 142 | BitMap += 1; |
| 143 | } |
| 144 | |
| 145 | if (Qwords > 0) { |
| 146 | SetMem64 ((VOID *)BitMap, Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES, 0); |
| 147 | BitMap += Qwords; |
| 148 | } |
| 149 | |
| 150 | if (Lsbs > 0) { |
| 151 | *BitMap &= ~(LShiftU64 (1, Lsbs) - 1); |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | Get corresponding bits in bitmap table according to the address. |
| 157 | |
| 158 | The value of bit 0 corresponds to the status of memory at given Address. |
| 159 | No more than 64 bits can be retrieved in one call. |
| 160 | |
| 161 | @param[in] Address Start address to retrieve bits for. |
| 162 | @param[in] BitNumber Number of bits to get. |
| 163 | @param[in] BitMap Pointer to bitmap which covers the Address. |
| 164 | |
| 165 | @return An integer containing the bits information. |
| 166 | **/ |
| 167 | STATIC |
| 168 | UINT64 |
| 169 | GetBits ( |
| 170 | IN EFI_PHYSICAL_ADDRESS Address, |
| 171 | IN UINTN BitNumber, |
| 172 | IN UINT64 *BitMap |
| 173 | ) |
| 174 | { |
| 175 | UINTN StartBit; |
| 176 | UINTN EndBit; |
| 177 | UINTN Lsbs; |
| 178 | UINTN Msbs; |
| 179 | UINT64 Result; |
| 180 | |
| 181 | ASSERT (BitNumber <= GUARDED_HEAP_MAP_ENTRY_BITS); |
| 182 | |
| 183 | StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address); |
| 184 | EndBit = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS; |
| 185 | |
| 186 | if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) { |
| 187 | Msbs = GUARDED_HEAP_MAP_ENTRY_BITS - StartBit; |
| 188 | Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS; |
| 189 | } else { |
| 190 | Msbs = BitNumber; |
| 191 | Lsbs = 0; |
| 192 | } |
| 193 | |
| 194 | Result = RShiftU64 ((*BitMap), StartBit) & (LShiftU64 (1, Msbs) - 1); |
| 195 | if (Lsbs > 0) { |
| 196 | BitMap += 1; |
| 197 | Result |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs); |
| 198 | } |
| 199 | |
| 200 | return Result; |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | Helper function to allocate pages without Guard for internal uses. |
| 205 | |
| 206 | @param[in] Pages Page number. |
| 207 | |
| 208 | @return Address of memory allocated. |
| 209 | **/ |
| 210 | VOID * |
| 211 | PageAlloc ( |
| 212 | IN UINTN Pages |
| 213 | ) |
| 214 | { |
| 215 | EFI_STATUS Status; |
| 216 | EFI_PHYSICAL_ADDRESS Memory; |
| 217 | |
| 218 | Status = SmmInternalAllocatePages (AllocateAnyPages, EfiRuntimeServicesData, |
| 219 | Pages, &Memory, FALSE); |
| 220 | if (EFI_ERROR (Status)) { |
| 221 | Memory = 0; |
| 222 | } |
| 223 | |
| 224 | return (VOID *)(UINTN)Memory; |
| 225 | } |
| 226 | |
| 227 | /** |
| 228 | Locate the pointer of bitmap from the guarded memory bitmap tables, which |
| 229 | covers the given Address. |
| 230 | |
| 231 | @param[in] Address Start address to search the bitmap for. |
| 232 | @param[in] AllocMapUnit Flag to indicate memory allocation for the table. |
| 233 | @param[out] BitMap Pointer to bitmap which covers the Address. |
| 234 | |
| 235 | @return The bit number from given Address to the end of current map table. |
| 236 | **/ |
| 237 | UINTN |
| 238 | FindGuardedMemoryMap ( |
| 239 | IN EFI_PHYSICAL_ADDRESS Address, |
| 240 | IN BOOLEAN AllocMapUnit, |
| 241 | OUT UINT64 **BitMap |
| 242 | ) |
| 243 | { |
| 244 | UINTN Level; |
| 245 | UINT64 *GuardMap; |
| 246 | UINT64 MapMemory; |
| 247 | UINTN Index; |
| 248 | UINTN Size; |
| 249 | UINTN BitsToUnitEnd; |
| 250 | |
| 251 | // |
| 252 | // Adjust current map table depth according to the address to access |
| 253 | // |
| 254 | while (mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH |
| 255 | && |
| 256 | RShiftU64 ( |
| 257 | Address, |
| 258 | mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1] |
| 259 | ) != 0) { |
| 260 | |
| 261 | if (mGuardedMemoryMap != 0) { |
| 262 | Size = (mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1] + 1) |
| 263 | * GUARDED_HEAP_MAP_ENTRY_BYTES; |
| 264 | MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size)); |
| 265 | ASSERT (MapMemory != 0); |
| 266 | |
| 267 | SetMem ((VOID *)(UINTN)MapMemory, Size, 0); |
| 268 | |
| 269 | *(UINT64 *)(UINTN)MapMemory = mGuardedMemoryMap; |
| 270 | mGuardedMemoryMap = MapMemory; |
| 271 | } |
| 272 | |
| 273 | mMapLevel++; |
| 274 | |
| 275 | } |
| 276 | |
| 277 | GuardMap = &mGuardedMemoryMap; |
| 278 | for (Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel; |
| 279 | Level < GUARDED_HEAP_MAP_TABLE_DEPTH; |
| 280 | ++Level) { |
| 281 | |
| 282 | if (*GuardMap == 0) { |
| 283 | if (!AllocMapUnit) { |
| 284 | GuardMap = NULL; |
| 285 | break; |
| 286 | } |
| 287 | |
| 288 | Size = (mLevelMask[Level] + 1) * GUARDED_HEAP_MAP_ENTRY_BYTES; |
| 289 | MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size)); |
| 290 | ASSERT (MapMemory != 0); |
| 291 | |
| 292 | SetMem ((VOID *)(UINTN)MapMemory, Size, 0); |
| 293 | *GuardMap = MapMemory; |
| 294 | } |
| 295 | |
| 296 | Index = (UINTN)RShiftU64 (Address, mLevelShift[Level]); |
| 297 | Index &= mLevelMask[Level]; |
| 298 | GuardMap = (UINT64 *)(UINTN)((*GuardMap) + Index * sizeof (UINT64)); |
| 299 | |
| 300 | } |
| 301 | |
| 302 | BitsToUnitEnd = GUARDED_HEAP_MAP_BITS - GUARDED_HEAP_MAP_BIT_INDEX (Address); |
| 303 | *BitMap = GuardMap; |
| 304 | |
| 305 | return BitsToUnitEnd; |
| 306 | } |
| 307 | |
| 308 | /** |
| 309 | Set corresponding bits in bitmap table to 1 according to given memory range. |
| 310 | |
| 311 | @param[in] Address Memory address to guard from. |
| 312 | @param[in] NumberOfPages Number of pages to guard. |
| 313 | |
| 314 | @return VOID |
| 315 | **/ |
| 316 | VOID |
| 317 | EFIAPI |
| 318 | SetGuardedMemoryBits ( |
| 319 | IN EFI_PHYSICAL_ADDRESS Address, |
| 320 | IN UINTN NumberOfPages |
| 321 | ) |
| 322 | { |
| 323 | UINT64 *BitMap; |
| 324 | UINTN Bits; |
| 325 | UINTN BitsToUnitEnd; |
| 326 | |
| 327 | while (NumberOfPages > 0) { |
| 328 | BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap); |
| 329 | ASSERT (BitMap != NULL); |
| 330 | |
| 331 | if (NumberOfPages > BitsToUnitEnd) { |
| 332 | // Cross map unit |
| 333 | Bits = BitsToUnitEnd; |
| 334 | } else { |
| 335 | Bits = NumberOfPages; |
| 336 | } |
| 337 | |
| 338 | SetBits (Address, Bits, BitMap); |
| 339 | |
| 340 | NumberOfPages -= Bits; |
| 341 | Address += EFI_PAGES_TO_SIZE (Bits); |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | /** |
| 346 | Clear corresponding bits in bitmap table according to given memory range. |
| 347 | |
| 348 | @param[in] Address Memory address to unset from. |
| 349 | @param[in] NumberOfPages Number of pages to unset guard. |
| 350 | |
| 351 | @return VOID |
| 352 | **/ |
| 353 | VOID |
| 354 | EFIAPI |
| 355 | ClearGuardedMemoryBits ( |
| 356 | IN EFI_PHYSICAL_ADDRESS Address, |
| 357 | IN UINTN NumberOfPages |
| 358 | ) |
| 359 | { |
| 360 | UINT64 *BitMap; |
| 361 | UINTN Bits; |
| 362 | UINTN BitsToUnitEnd; |
| 363 | |
| 364 | while (NumberOfPages > 0) { |
| 365 | BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap); |
| 366 | ASSERT (BitMap != NULL); |
| 367 | |
| 368 | if (NumberOfPages > BitsToUnitEnd) { |
| 369 | // Cross map unit |
| 370 | Bits = BitsToUnitEnd; |
| 371 | } else { |
| 372 | Bits = NumberOfPages; |
| 373 | } |
| 374 | |
| 375 | ClearBits (Address, Bits, BitMap); |
| 376 | |
| 377 | NumberOfPages -= Bits; |
| 378 | Address += EFI_PAGES_TO_SIZE (Bits); |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | /** |
| 383 | Retrieve corresponding bits in bitmap table according to given memory range. |
| 384 | |
| 385 | @param[in] Address Memory address to retrieve from. |
| 386 | @param[in] NumberOfPages Number of pages to retrieve. |
| 387 | |
| 388 | @return An integer containing the guarded memory bitmap. |
| 389 | **/ |
| 390 | UINTN |
| 391 | GetGuardedMemoryBits ( |
| 392 | IN EFI_PHYSICAL_ADDRESS Address, |
| 393 | IN UINTN NumberOfPages |
| 394 | ) |
| 395 | { |
| 396 | UINT64 *BitMap; |
| 397 | UINTN Bits; |
| 398 | UINTN Result; |
| 399 | UINTN Shift; |
| 400 | UINTN BitsToUnitEnd; |
| 401 | |
| 402 | ASSERT (NumberOfPages <= GUARDED_HEAP_MAP_ENTRY_BITS); |
| 403 | |
| 404 | Result = 0; |
| 405 | Shift = 0; |
| 406 | while (NumberOfPages > 0) { |
| 407 | BitsToUnitEnd = FindGuardedMemoryMap (Address, FALSE, &BitMap); |
| 408 | |
| 409 | if (NumberOfPages > BitsToUnitEnd) { |
| 410 | // Cross map unit |
| 411 | Bits = BitsToUnitEnd; |
| 412 | } else { |
| 413 | Bits = NumberOfPages; |
| 414 | } |
| 415 | |
| 416 | if (BitMap != NULL) { |
| 417 | Result |= LShiftU64 (GetBits (Address, Bits, BitMap), Shift); |
| 418 | } |
| 419 | |
| 420 | Shift += Bits; |
| 421 | NumberOfPages -= Bits; |
| 422 | Address += EFI_PAGES_TO_SIZE (Bits); |
| 423 | } |
| 424 | |
| 425 | return Result; |
| 426 | } |
| 427 | |
| 428 | /** |
| 429 | Get bit value in bitmap table for the given address. |
| 430 | |
| 431 | @param[in] Address The address to retrieve for. |
| 432 | |
| 433 | @return 1 or 0. |
| 434 | **/ |
| 435 | UINTN |
| 436 | EFIAPI |
| 437 | GetGuardMapBit ( |
| 438 | IN EFI_PHYSICAL_ADDRESS Address |
| 439 | ) |
| 440 | { |
| 441 | UINT64 *GuardMap; |
| 442 | |
| 443 | FindGuardedMemoryMap (Address, FALSE, &GuardMap); |
| 444 | if (GuardMap != NULL) { |
| 445 | if (RShiftU64 (*GuardMap, |
| 446 | GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)) & 1) { |
| 447 | return 1; |
| 448 | } |
| 449 | } |
| 450 | |
| 451 | return 0; |
| 452 | } |
| 453 | |
| 454 | /** |
| 455 | Set the bit in bitmap table for the given address. |
| 456 | |
| 457 | @param[in] Address The address to set for. |
| 458 | |
| 459 | @return VOID. |
| 460 | **/ |
| 461 | VOID |
| 462 | EFIAPI |
| 463 | SetGuardMapBit ( |
| 464 | IN EFI_PHYSICAL_ADDRESS Address |
| 465 | ) |
| 466 | { |
| 467 | UINT64 *GuardMap; |
| 468 | UINT64 BitMask; |
| 469 | |
| 470 | FindGuardedMemoryMap (Address, TRUE, &GuardMap); |
| 471 | if (GuardMap != NULL) { |
| 472 | BitMask = LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)); |
| 473 | *GuardMap |= BitMask; |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | /** |
| 478 | Clear the bit in bitmap table for the given address. |
| 479 | |
| 480 | @param[in] Address The address to clear for. |
| 481 | |
| 482 | @return VOID. |
| 483 | **/ |
| 484 | VOID |
| 485 | EFIAPI |
| 486 | ClearGuardMapBit ( |
| 487 | IN EFI_PHYSICAL_ADDRESS Address |
| 488 | ) |
| 489 | { |
| 490 | UINT64 *GuardMap; |
| 491 | UINT64 BitMask; |
| 492 | |
| 493 | FindGuardedMemoryMap (Address, TRUE, &GuardMap); |
| 494 | if (GuardMap != NULL) { |
| 495 | BitMask = LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)); |
| 496 | *GuardMap &= ~BitMask; |
| 497 | } |
| 498 | } |
| 499 | |
| 500 | /** |
| 501 | Check to see if the page at the given address is a Guard page or not. |
| 502 | |
| 503 | @param[in] Address The address to check for. |
| 504 | |
| 505 | @return TRUE The page at Address is a Guard page. |
| 506 | @return FALSE The page at Address is not a Guard page. |
| 507 | **/ |
| 508 | BOOLEAN |
| 509 | EFIAPI |
| 510 | IsGuardPage ( |
| 511 | IN EFI_PHYSICAL_ADDRESS Address |
| 512 | ) |
| 513 | { |
| 514 | UINTN BitMap; |
| 515 | |
| 516 | // |
| 517 | // There must be at least one guarded page before and/or after given |
| 518 | // address if it's a Guard page. The bitmap pattern should be one of |
| 519 | // 001, 100 and 101 |
| 520 | // |
| 521 | BitMap = GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 3); |
| 522 | return ((BitMap == BIT0) || (BitMap == BIT2) || (BitMap == (BIT2 | BIT0))); |
| 523 | } |
| 524 | |
| 525 | /** |
| 526 | Check to see if the page at the given address is a head Guard page or not. |
| 527 | |
| 528 | @param[in] Address The address to check for. |
| 529 | |
| 530 | @return TRUE The page at Address is a head Guard page. |
| 531 | @return FALSE The page at Address is not a head Guard page. |
| 532 | **/ |
| 533 | BOOLEAN |
| 534 | EFIAPI |
| 535 | IsHeadGuard ( |
| 536 | IN EFI_PHYSICAL_ADDRESS Address |
| 537 | ) |
| 538 | { |
| 539 | return (GetGuardedMemoryBits (Address, 2) == BIT1); |
| 540 | } |
| 541 | |
| 542 | /** |
| 543 | Check to see if the page at the given address is a tail Guard page or not. |
| 544 | |
| 545 | @param[in] Address The address to check for. |
| 546 | |
| 547 | @return TRUE The page at Address is a tail Guard page. |
| 548 | @return FALSE The page at Address is not a tail Guard page. |
| 549 | **/ |
| 550 | BOOLEAN |
| 551 | EFIAPI |
| 552 | IsTailGuard ( |
| 553 | IN EFI_PHYSICAL_ADDRESS Address |
| 554 | ) |
| 555 | { |
| 556 | return (GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 2) == BIT0); |
| 557 | } |
| 558 | |
| 559 | /** |
| 560 | Check to see if the page at the given address is guarded or not. |
| 561 | |
| 562 | @param[in] Address The address to check for. |
| 563 | |
| 564 | @return TRUE The page at Address is guarded. |
| 565 | @return FALSE The page at Address is not guarded. |
| 566 | **/ |
| 567 | BOOLEAN |
| 568 | EFIAPI |
| 569 | IsMemoryGuarded ( |
| 570 | IN EFI_PHYSICAL_ADDRESS Address |
| 571 | ) |
| 572 | { |
| 573 | return (GetGuardMapBit (Address) == 1); |
| 574 | } |
| 575 | |
| 576 | /** |
| 577 | Set the page at the given address to be a Guard page. |
| 578 | |
| 579 | This is done by changing the page table attribute to be NOT PRSENT. |
| 580 | |
| 581 | @param[in] BaseAddress Page address to Guard at. |
| 582 | |
| 583 | @return VOID. |
| 584 | **/ |
| 585 | VOID |
| 586 | EFIAPI |
| 587 | SetGuardPage ( |
| 588 | IN EFI_PHYSICAL_ADDRESS BaseAddress |
| 589 | ) |
| 590 | { |
| 591 | if (mSmmMemoryAttribute != NULL) { |
| 592 | mOnGuarding = TRUE; |
| 593 | mSmmMemoryAttribute->SetMemoryAttributes ( |
| 594 | mSmmMemoryAttribute, |
| 595 | BaseAddress, |
| 596 | EFI_PAGE_SIZE, |
| 597 | EFI_MEMORY_RP |
| 598 | ); |
| 599 | mOnGuarding = FALSE; |
| 600 | } |
| 601 | } |
| 602 | |
| 603 | /** |
| 604 | Unset the Guard page at the given address to the normal memory. |
| 605 | |
| 606 | This is done by changing the page table attribute to be PRSENT. |
| 607 | |
| 608 | @param[in] BaseAddress Page address to Guard at. |
| 609 | |
| 610 | @return VOID. |
| 611 | **/ |
| 612 | VOID |
| 613 | EFIAPI |
| 614 | UnsetGuardPage ( |
| 615 | IN EFI_PHYSICAL_ADDRESS BaseAddress |
| 616 | ) |
| 617 | { |
| 618 | if (mSmmMemoryAttribute != NULL) { |
| 619 | mOnGuarding = TRUE; |
| 620 | mSmmMemoryAttribute->ClearMemoryAttributes ( |
| 621 | mSmmMemoryAttribute, |
| 622 | BaseAddress, |
| 623 | EFI_PAGE_SIZE, |
| 624 | EFI_MEMORY_RP |
| 625 | ); |
| 626 | mOnGuarding = FALSE; |
| 627 | } |
| 628 | } |
| 629 | |
| 630 | /** |
| 631 | Check to see if the memory at the given address should be guarded or not. |
| 632 | |
| 633 | @param[in] MemoryType Memory type to check. |
| 634 | @param[in] AllocateType Allocation type to check. |
| 635 | @param[in] PageOrPool Indicate a page allocation or pool allocation. |
| 636 | |
| 637 | |
| 638 | @return TRUE The given type of memory should be guarded. |
| 639 | @return FALSE The given type of memory should not be guarded. |
| 640 | **/ |
| 641 | BOOLEAN |
| 642 | IsMemoryTypeToGuard ( |
| 643 | IN EFI_MEMORY_TYPE MemoryType, |
| 644 | IN EFI_ALLOCATE_TYPE AllocateType, |
| 645 | IN UINT8 PageOrPool |
| 646 | ) |
| 647 | { |
| 648 | UINT64 TestBit; |
| 649 | UINT64 ConfigBit; |
| 650 | |
| 651 | if ((PcdGet8 (PcdHeapGuardPropertyMask) & PageOrPool) == 0 |
| 652 | || mOnGuarding |
| 653 | || AllocateType == AllocateAddress) { |
| 654 | return FALSE; |
| 655 | } |
| 656 | |
| 657 | ConfigBit = 0; |
| 658 | if ((PageOrPool & GUARD_HEAP_TYPE_POOL) != 0) { |
| 659 | ConfigBit |= PcdGet64 (PcdHeapGuardPoolType); |
| 660 | } |
| 661 | |
| 662 | if ((PageOrPool & GUARD_HEAP_TYPE_PAGE) != 0) { |
| 663 | ConfigBit |= PcdGet64 (PcdHeapGuardPageType); |
| 664 | } |
| 665 | |
| 666 | if (MemoryType == EfiRuntimeServicesData || |
| 667 | MemoryType == EfiRuntimeServicesCode) { |
| 668 | TestBit = LShiftU64 (1, MemoryType); |
| 669 | } else if (MemoryType == EfiMaxMemoryType) { |
| 670 | TestBit = (UINT64)-1; |
| 671 | } else { |
| 672 | TestBit = 0; |
| 673 | } |
| 674 | |
| 675 | return ((ConfigBit & TestBit) != 0); |
| 676 | } |
| 677 | |
| 678 | /** |
| 679 | Check to see if the pool at the given address should be guarded or not. |
| 680 | |
| 681 | @param[in] MemoryType Pool type to check. |
| 682 | |
| 683 | |
| 684 | @return TRUE The given type of pool should be guarded. |
| 685 | @return FALSE The given type of pool should not be guarded. |
| 686 | **/ |
| 687 | BOOLEAN |
| 688 | IsPoolTypeToGuard ( |
| 689 | IN EFI_MEMORY_TYPE MemoryType |
| 690 | ) |
| 691 | { |
| 692 | return IsMemoryTypeToGuard (MemoryType, AllocateAnyPages, |
| 693 | GUARD_HEAP_TYPE_POOL); |
| 694 | } |
| 695 | |
| 696 | /** |
| 697 | Check to see if the page at the given address should be guarded or not. |
| 698 | |
| 699 | @param[in] MemoryType Page type to check. |
| 700 | @param[in] AllocateType Allocation type to check. |
| 701 | |
| 702 | @return TRUE The given type of page should be guarded. |
| 703 | @return FALSE The given type of page should not be guarded. |
| 704 | **/ |
| 705 | BOOLEAN |
| 706 | IsPageTypeToGuard ( |
| 707 | IN EFI_MEMORY_TYPE MemoryType, |
| 708 | IN EFI_ALLOCATE_TYPE AllocateType |
| 709 | ) |
| 710 | { |
| 711 | return IsMemoryTypeToGuard (MemoryType, AllocateType, GUARD_HEAP_TYPE_PAGE); |
| 712 | } |
| 713 | |
| 714 | /** |
| 715 | Check to see if the heap guard is enabled for page and/or pool allocation. |
| 716 | |
| 717 | @return TRUE/FALSE. |
| 718 | **/ |
| 719 | BOOLEAN |
| 720 | IsHeapGuardEnabled ( |
| 721 | VOID |
| 722 | ) |
| 723 | { |
| 724 | return IsMemoryTypeToGuard (EfiMaxMemoryType, AllocateAnyPages, |
| 725 | GUARD_HEAP_TYPE_POOL|GUARD_HEAP_TYPE_PAGE); |
| 726 | } |
| 727 | |
| 728 | /** |
| 729 | Set head Guard and tail Guard for the given memory range. |
| 730 | |
| 731 | @param[in] Memory Base address of memory to set guard for. |
| 732 | @param[in] NumberOfPages Memory size in pages. |
| 733 | |
| 734 | @return VOID. |
| 735 | **/ |
| 736 | VOID |
| 737 | SetGuardForMemory ( |
| 738 | IN EFI_PHYSICAL_ADDRESS Memory, |
| 739 | IN UINTN NumberOfPages |
| 740 | ) |
| 741 | { |
| 742 | EFI_PHYSICAL_ADDRESS GuardPage; |
| 743 | |
| 744 | // |
| 745 | // Set tail Guard |
| 746 | // |
| 747 | GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages); |
| 748 | if (!IsGuardPage (GuardPage)) { |
| 749 | SetGuardPage (GuardPage); |
| 750 | } |
| 751 | |
| 752 | // Set head Guard |
| 753 | GuardPage = Memory - EFI_PAGES_TO_SIZE (1); |
| 754 | if (!IsGuardPage (GuardPage)) { |
| 755 | SetGuardPage (GuardPage); |
| 756 | } |
| 757 | |
| 758 | // |
| 759 | // Mark the memory range as Guarded |
| 760 | // |
| 761 | SetGuardedMemoryBits (Memory, NumberOfPages); |
| 762 | } |
| 763 | |
| 764 | /** |
| 765 | Unset head Guard and tail Guard for the given memory range. |
| 766 | |
| 767 | @param[in] Memory Base address of memory to unset guard for. |
| 768 | @param[in] NumberOfPages Memory size in pages. |
| 769 | |
| 770 | @return VOID. |
| 771 | **/ |
| 772 | VOID |
| 773 | UnsetGuardForMemory ( |
| 774 | IN EFI_PHYSICAL_ADDRESS Memory, |
| 775 | IN UINTN NumberOfPages |
| 776 | ) |
| 777 | { |
| 778 | EFI_PHYSICAL_ADDRESS GuardPage; |
| 779 | |
| 780 | if (NumberOfPages == 0) { |
| 781 | return; |
| 782 | } |
| 783 | |
| 784 | // |
| 785 | // Head Guard must be one page before, if any. |
| 786 | // |
| 787 | GuardPage = Memory - EFI_PAGES_TO_SIZE (1); |
| 788 | if (IsHeadGuard (GuardPage)) { |
| 789 | if (!IsMemoryGuarded (GuardPage - EFI_PAGES_TO_SIZE (1))) { |
| 790 | // |
| 791 | // If the head Guard is not a tail Guard of adjacent memory block, |
| 792 | // unset it. |
| 793 | // |
| 794 | UnsetGuardPage (GuardPage); |
| 795 | } |
| 796 | } else if (IsMemoryGuarded (GuardPage)) { |
| 797 | // |
| 798 | // Pages before memory to free are still in Guard. It's a partial free |
| 799 | // case. Turn first page of memory block to free into a new Guard. |
| 800 | // |
| 801 | SetGuardPage (Memory); |
| 802 | } |
| 803 | |
| 804 | // |
| 805 | // Tail Guard must be the page after this memory block to free, if any. |
| 806 | // |
| 807 | GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages); |
| 808 | if (IsTailGuard (GuardPage)) { |
| 809 | if (!IsMemoryGuarded (GuardPage + EFI_PAGES_TO_SIZE (1))) { |
| 810 | // |
| 811 | // If the tail Guard is not a head Guard of adjacent memory block, |
| 812 | // free it; otherwise, keep it. |
| 813 | // |
| 814 | UnsetGuardPage (GuardPage); |
| 815 | } |
| 816 | } else if (IsMemoryGuarded (GuardPage)) { |
| 817 | // |
| 818 | // Pages after memory to free are still in Guard. It's a partial free |
| 819 | // case. We need to keep one page to be a head Guard. |
| 820 | // |
| 821 | SetGuardPage (GuardPage - EFI_PAGES_TO_SIZE (1)); |
| 822 | } |
| 823 | |
| 824 | // |
| 825 | // No matter what, we just clear the mark of the Guarded memory. |
| 826 | // |
| 827 | ClearGuardedMemoryBits(Memory, NumberOfPages); |
| 828 | } |
| 829 | |
| 830 | /** |
| 831 | Adjust address of free memory according to existing and/or required Guard. |
| 832 | |
| 833 | This function will check if there're existing Guard pages of adjacent |
| 834 | memory blocks, and try to use it as the Guard page of the memory to be |
| 835 | allocated. |
| 836 | |
| 837 | @param[in] Start Start address of free memory block. |
| 838 | @param[in] Size Size of free memory block. |
| 839 | @param[in] SizeRequested Size of memory to allocate. |
| 840 | |
| 841 | @return The end address of memory block found. |
| 842 | @return 0 if no enough space for the required size of memory and its Guard. |
| 843 | **/ |
| 844 | UINT64 |
| 845 | AdjustMemoryS ( |
| 846 | IN UINT64 Start, |
| 847 | IN UINT64 Size, |
| 848 | IN UINT64 SizeRequested |
| 849 | ) |
| 850 | { |
| 851 | UINT64 Target; |
| 852 | |
| 853 | Target = Start + Size - SizeRequested; |
| 854 | |
| 855 | // |
| 856 | // At least one more page needed for Guard page. |
| 857 | // |
| 858 | if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) { |
| 859 | return 0; |
| 860 | } |
| 861 | |
| 862 | if (!IsGuardPage (Start + Size)) { |
| 863 | // No Guard at tail to share. One more page is needed. |
| 864 | Target -= EFI_PAGES_TO_SIZE (1); |
| 865 | } |
| 866 | |
| 867 | // Out of range? |
| 868 | if (Target < Start) { |
| 869 | return 0; |
| 870 | } |
| 871 | |
| 872 | // At the edge? |
| 873 | if (Target == Start) { |
| 874 | if (!IsGuardPage (Target - EFI_PAGES_TO_SIZE (1))) { |
| 875 | // No enough space for a new head Guard if no Guard at head to share. |
| 876 | return 0; |
| 877 | } |
| 878 | } |
| 879 | |
| 880 | // OK, we have enough pages for memory and its Guards. Return the End of the |
| 881 | // free space. |
| 882 | return Target + SizeRequested - 1; |
| 883 | } |
| 884 | |
| 885 | /** |
| 886 | Adjust the start address and number of pages to free according to Guard. |
| 887 | |
| 888 | The purpose of this function is to keep the shared Guard page with adjacent |
| 889 | memory block if it's still in guard, or free it if no more sharing. Another |
| 890 | is to reserve pages as Guard pages in partial page free situation. |
| 891 | |
| 892 | @param[in,out] Memory Base address of memory to free. |
| 893 | @param[in,out] NumberOfPages Size of memory to free. |
| 894 | |
| 895 | @return VOID. |
| 896 | **/ |
| 897 | VOID |
| 898 | AdjustMemoryF ( |
| 899 | IN OUT EFI_PHYSICAL_ADDRESS *Memory, |
| 900 | IN OUT UINTN *NumberOfPages |
| 901 | ) |
| 902 | { |
| 903 | EFI_PHYSICAL_ADDRESS Start; |
| 904 | EFI_PHYSICAL_ADDRESS MemoryToTest; |
| 905 | UINTN PagesToFree; |
| 906 | |
| 907 | if (Memory == NULL || NumberOfPages == NULL || *NumberOfPages == 0) { |
| 908 | return; |
| 909 | } |
| 910 | |
| 911 | Start = *Memory; |
| 912 | PagesToFree = *NumberOfPages; |
| 913 | |
| 914 | // |
| 915 | // Head Guard must be one page before, if any. |
| 916 | // |
| 917 | MemoryToTest = Start - EFI_PAGES_TO_SIZE (1); |
| 918 | if (IsHeadGuard (MemoryToTest)) { |
| 919 | if (!IsMemoryGuarded (MemoryToTest - EFI_PAGES_TO_SIZE (1))) { |
| 920 | // |
| 921 | // If the head Guard is not a tail Guard of adjacent memory block, |
| 922 | // free it; otherwise, keep it. |
| 923 | // |
| 924 | Start -= EFI_PAGES_TO_SIZE (1); |
| 925 | PagesToFree += 1; |
| 926 | } |
| 927 | } else if (IsMemoryGuarded (MemoryToTest)) { |
| 928 | // |
| 929 | // Pages before memory to free are still in Guard. It's a partial free |
| 930 | // case. We need to keep one page to be a tail Guard. |
| 931 | // |
| 932 | Start += EFI_PAGES_TO_SIZE (1); |
| 933 | PagesToFree -= 1; |
| 934 | } |
| 935 | |
| 936 | // |
| 937 | // Tail Guard must be the page after this memory block to free, if any. |
| 938 | // |
| 939 | MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree); |
| 940 | if (IsTailGuard (MemoryToTest)) { |
| 941 | if (!IsMemoryGuarded (MemoryToTest + EFI_PAGES_TO_SIZE (1))) { |
| 942 | // |
| 943 | // If the tail Guard is not a head Guard of adjacent memory block, |
| 944 | // free it; otherwise, keep it. |
| 945 | // |
| 946 | PagesToFree += 1; |
| 947 | } |
| 948 | } else if (IsMemoryGuarded (MemoryToTest)) { |
| 949 | // |
| 950 | // Pages after memory to free are still in Guard. It's a partial free |
| 951 | // case. We need to keep one page to be a head Guard. |
| 952 | // |
| 953 | PagesToFree -= 1; |
| 954 | } |
| 955 | |
| 956 | *Memory = Start; |
| 957 | *NumberOfPages = PagesToFree; |
| 958 | } |
| 959 | |
| 960 | /** |
| 961 | Adjust the base and number of pages to really allocate according to Guard. |
| 962 | |
| 963 | @param[in,out] Memory Base address of free memory. |
| 964 | @param[in,out] NumberOfPages Size of memory to allocate. |
| 965 | |
| 966 | @return VOID. |
| 967 | **/ |
| 968 | VOID |
| 969 | AdjustMemoryA ( |
| 970 | IN OUT EFI_PHYSICAL_ADDRESS *Memory, |
| 971 | IN OUT UINTN *NumberOfPages |
| 972 | ) |
| 973 | { |
| 974 | // |
| 975 | // FindFreePages() has already taken the Guard into account. It's safe to |
| 976 | // adjust the start address and/or number of pages here, to make sure that |
| 977 | // the Guards are also "allocated". |
| 978 | // |
| 979 | if (!IsGuardPage (*Memory + EFI_PAGES_TO_SIZE (*NumberOfPages))) { |
| 980 | // No tail Guard, add one. |
| 981 | *NumberOfPages += 1; |
| 982 | } |
| 983 | |
| 984 | if (!IsGuardPage (*Memory - EFI_PAGE_SIZE)) { |
| 985 | // No head Guard, add one. |
| 986 | *Memory -= EFI_PAGE_SIZE; |
| 987 | *NumberOfPages += 1; |
| 988 | } |
| 989 | } |
| 990 | |
| 991 | /** |
| 992 | Adjust the pool head position to make sure the Guard page is adjavent to |
| 993 | pool tail or pool head. |
| 994 | |
| 995 | @param[in] Memory Base address of memory allocated. |
| 996 | @param[in] NoPages Number of pages actually allocated. |
| 997 | @param[in] Size Size of memory requested. |
| 998 | (plus pool head/tail overhead) |
| 999 | |
| 1000 | @return Address of pool head |
| 1001 | **/ |
| 1002 | VOID * |
| 1003 | AdjustPoolHeadA ( |
| 1004 | IN EFI_PHYSICAL_ADDRESS Memory, |
| 1005 | IN UINTN NoPages, |
| 1006 | IN UINTN Size |
| 1007 | ) |
| 1008 | { |
| 1009 | if ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0) { |
| 1010 | // |
| 1011 | // Pool head is put near the head Guard |
| 1012 | // |
| 1013 | return (VOID *)(UINTN)Memory; |
| 1014 | } |
| 1015 | |
| 1016 | // |
| 1017 | // Pool head is put near the tail Guard |
| 1018 | // |
| 1019 | return (VOID *)(UINTN)(Memory + EFI_PAGES_TO_SIZE (NoPages) - Size); |
| 1020 | } |
| 1021 | |
| 1022 | /** |
| 1023 | Get the page base address according to pool head address. |
| 1024 | |
| 1025 | @param[in] Memory Head address of pool to free. |
| 1026 | |
| 1027 | @return Address of pool head. |
| 1028 | **/ |
| 1029 | VOID * |
| 1030 | AdjustPoolHeadF ( |
| 1031 | IN EFI_PHYSICAL_ADDRESS Memory |
| 1032 | ) |
| 1033 | { |
| 1034 | if ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0) { |
| 1035 | // |
| 1036 | // Pool head is put near the head Guard |
| 1037 | // |
| 1038 | return (VOID *)(UINTN)Memory; |
| 1039 | } |
| 1040 | |
| 1041 | // |
| 1042 | // Pool head is put near the tail Guard |
| 1043 | // |
| 1044 | return (VOID *)(UINTN)(Memory & ~EFI_PAGE_MASK); |
| 1045 | } |
| 1046 | |
| 1047 | /** |
| 1048 | Helper function of memory allocation with Guard pages. |
| 1049 | |
| 1050 | @param FreePageList The free page node. |
| 1051 | @param NumberOfPages Number of pages to be allocated. |
| 1052 | @param MaxAddress Request to allocate memory below this address. |
| 1053 | @param MemoryType Type of memory requested. |
| 1054 | |
| 1055 | @return Memory address of allocated pages. |
| 1056 | **/ |
| 1057 | UINTN |
| 1058 | InternalAllocMaxAddressWithGuard ( |
| 1059 | IN OUT LIST_ENTRY *FreePageList, |
| 1060 | IN UINTN NumberOfPages, |
| 1061 | IN UINTN MaxAddress, |
| 1062 | IN EFI_MEMORY_TYPE MemoryType |
| 1063 | |
| 1064 | ) |
| 1065 | { |
| 1066 | LIST_ENTRY *Node; |
| 1067 | FREE_PAGE_LIST *Pages; |
| 1068 | UINTN PagesToAlloc; |
| 1069 | UINTN HeadGuard; |
| 1070 | UINTN TailGuard; |
| 1071 | UINTN Address; |
| 1072 | |
| 1073 | for (Node = FreePageList->BackLink; Node != FreePageList; |
| 1074 | Node = Node->BackLink) { |
| 1075 | Pages = BASE_CR (Node, FREE_PAGE_LIST, Link); |
| 1076 | if (Pages->NumberOfPages >= NumberOfPages && |
| 1077 | (UINTN)Pages + EFI_PAGES_TO_SIZE (NumberOfPages) - 1 <= MaxAddress) { |
| 1078 | |
| 1079 | // |
| 1080 | // We may need 1 or 2 more pages for Guard. Check it out. |
| 1081 | // |
| 1082 | PagesToAlloc = NumberOfPages; |
| 1083 | TailGuard = (UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages); |
| 1084 | if (!IsGuardPage (TailGuard)) { |
| 1085 | // |
| 1086 | // Add one if no Guard at the end of current free memory block. |
| 1087 | // |
| 1088 | PagesToAlloc += 1; |
| 1089 | TailGuard = 0; |
| 1090 | } |
| 1091 | |
| 1092 | HeadGuard = (UINTN)Pages + |
| 1093 | EFI_PAGES_TO_SIZE (Pages->NumberOfPages - PagesToAlloc) - |
| 1094 | EFI_PAGE_SIZE; |
| 1095 | if (!IsGuardPage (HeadGuard)) { |
| 1096 | // |
| 1097 | // Add one if no Guard at the page before the address to allocate |
| 1098 | // |
| 1099 | PagesToAlloc += 1; |
| 1100 | HeadGuard = 0; |
| 1101 | } |
| 1102 | |
| 1103 | if (Pages->NumberOfPages < PagesToAlloc) { |
| 1104 | // Not enough space to allocate memory with Guards? Try next block. |
| 1105 | continue; |
| 1106 | } |
| 1107 | |
| 1108 | Address = InternalAllocPagesOnOneNode (Pages, PagesToAlloc, MaxAddress); |
| 1109 | ConvertSmmMemoryMapEntry(MemoryType, Address, PagesToAlloc, FALSE); |
| 1110 | CoreFreeMemoryMapStack(); |
| 1111 | if (HeadGuard == 0) { |
| 1112 | // Don't pass the Guard page to user. |
| 1113 | Address += EFI_PAGE_SIZE; |
| 1114 | } |
| 1115 | SetGuardForMemory (Address, NumberOfPages); |
| 1116 | return Address; |
| 1117 | } |
| 1118 | } |
| 1119 | |
| 1120 | return (UINTN)(-1); |
| 1121 | } |
| 1122 | |
| 1123 | /** |
| 1124 | Helper function of memory free with Guard pages. |
| 1125 | |
| 1126 | @param[in] Memory Base address of memory being freed. |
| 1127 | @param[in] NumberOfPages The number of pages to free. |
| 1128 | @param[in] AddRegion If this memory is new added region. |
| 1129 | |
| 1130 | @retval EFI_NOT_FOUND Could not find the entry that covers the range. |
| 1131 | @retval EFI_INVALID_PARAMETER Address not aligned, Address is zero or NumberOfPages is zero. |
| 1132 | @return EFI_SUCCESS Pages successfully freed. |
| 1133 | **/ |
| 1134 | EFI_STATUS |
| 1135 | SmmInternalFreePagesExWithGuard ( |
| 1136 | IN EFI_PHYSICAL_ADDRESS Memory, |
| 1137 | IN UINTN NumberOfPages, |
| 1138 | IN BOOLEAN AddRegion |
| 1139 | ) |
| 1140 | { |
| 1141 | EFI_PHYSICAL_ADDRESS MemoryToFree; |
| 1142 | UINTN PagesToFree; |
| 1143 | |
| 1144 | MemoryToFree = Memory; |
| 1145 | PagesToFree = NumberOfPages; |
| 1146 | |
| 1147 | AdjustMemoryF (&MemoryToFree, &PagesToFree); |
| 1148 | UnsetGuardForMemory (Memory, NumberOfPages); |
| 1149 | |
| 1150 | return SmmInternalFreePagesEx (MemoryToFree, PagesToFree, AddRegion); |
| 1151 | } |
| 1152 | |
| 1153 | /** |
| 1154 | Set all Guard pages which cannot be set during the non-SMM mode time. |
| 1155 | **/ |
| 1156 | VOID |
| 1157 | SetAllGuardPages ( |
| 1158 | VOID |
| 1159 | ) |
| 1160 | { |
| 1161 | UINTN Entries[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1162 | UINTN Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1163 | UINTN Indices[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1164 | UINT64 Tables[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1165 | UINT64 Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1166 | UINT64 TableEntry; |
| 1167 | UINT64 Address; |
| 1168 | UINT64 GuardPage; |
| 1169 | INTN Level; |
| 1170 | UINTN Index; |
| 1171 | BOOLEAN OnGuarding; |
| 1172 | |
| 1173 | if (mGuardedMemoryMap == 0) { |
| 1174 | return; |
| 1175 | } |
| 1176 | |
| 1177 | CopyMem (Entries, mLevelMask, sizeof (Entries)); |
| 1178 | CopyMem (Shifts, mLevelShift, sizeof (Shifts)); |
| 1179 | |
| 1180 | SetMem (Tables, sizeof(Tables), 0); |
| 1181 | SetMem (Addresses, sizeof(Addresses), 0); |
| 1182 | SetMem (Indices, sizeof(Indices), 0); |
| 1183 | |
| 1184 | Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel; |
| 1185 | Tables[Level] = mGuardedMemoryMap; |
| 1186 | Address = 0; |
| 1187 | OnGuarding = FALSE; |
| 1188 | |
| 1189 | DEBUG_CODE ( |
| 1190 | DumpGuardedMemoryBitmap (); |
| 1191 | ); |
| 1192 | |
| 1193 | while (TRUE) { |
| 1194 | if (Indices[Level] > Entries[Level]) { |
| 1195 | Tables[Level] = 0; |
| 1196 | Level -= 1; |
| 1197 | } else { |
| 1198 | |
| 1199 | TableEntry = ((UINT64 *)(UINTN)(Tables[Level]))[Indices[Level]]; |
| 1200 | Address = Addresses[Level]; |
| 1201 | |
| 1202 | if (TableEntry == 0) { |
| 1203 | |
| 1204 | OnGuarding = FALSE; |
| 1205 | |
| 1206 | } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) { |
| 1207 | |
| 1208 | Level += 1; |
| 1209 | Tables[Level] = TableEntry; |
| 1210 | Addresses[Level] = Address; |
| 1211 | Indices[Level] = 0; |
| 1212 | |
| 1213 | continue; |
| 1214 | |
| 1215 | } else { |
| 1216 | |
| 1217 | Index = 0; |
| 1218 | while (Index < GUARDED_HEAP_MAP_ENTRY_BITS) { |
| 1219 | if ((TableEntry & 1) == 1) { |
| 1220 | if (OnGuarding) { |
| 1221 | GuardPage = 0; |
| 1222 | } else { |
| 1223 | GuardPage = Address - EFI_PAGE_SIZE; |
| 1224 | } |
| 1225 | OnGuarding = TRUE; |
| 1226 | } else { |
| 1227 | if (OnGuarding) { |
| 1228 | GuardPage = Address; |
| 1229 | } else { |
| 1230 | GuardPage = 0; |
| 1231 | } |
| 1232 | OnGuarding = FALSE; |
| 1233 | } |
| 1234 | |
| 1235 | if (GuardPage != 0) { |
| 1236 | SetGuardPage (GuardPage); |
| 1237 | } |
| 1238 | |
| 1239 | if (TableEntry == 0) { |
| 1240 | break; |
| 1241 | } |
| 1242 | |
| 1243 | TableEntry = RShiftU64 (TableEntry, 1); |
| 1244 | Address += EFI_PAGE_SIZE; |
| 1245 | Index += 1; |
| 1246 | } |
| 1247 | } |
| 1248 | } |
| 1249 | |
| 1250 | if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) { |
| 1251 | break; |
| 1252 | } |
| 1253 | |
| 1254 | Indices[Level] += 1; |
| 1255 | Address = (Level == 0) ? 0 : Addresses[Level - 1]; |
| 1256 | Addresses[Level] = Address | LShiftU64(Indices[Level], Shifts[Level]); |
| 1257 | |
| 1258 | } |
| 1259 | } |
| 1260 | |
| 1261 | /** |
| 1262 | Hook function used to set all Guard pages after entering SMM mode. |
| 1263 | **/ |
| 1264 | VOID |
| 1265 | SmmEntryPointMemoryManagementHook ( |
| 1266 | VOID |
| 1267 | ) |
| 1268 | { |
| 1269 | EFI_STATUS Status; |
| 1270 | |
| 1271 | if (mSmmMemoryAttribute == NULL) { |
| 1272 | Status = SmmLocateProtocol ( |
| 1273 | &gEdkiiSmmMemoryAttributeProtocolGuid, |
| 1274 | NULL, |
| 1275 | (VOID **)&mSmmMemoryAttribute |
| 1276 | ); |
| 1277 | if (!EFI_ERROR(Status)) { |
| 1278 | SetAllGuardPages (); |
| 1279 | } |
| 1280 | } |
| 1281 | } |
| 1282 | |
| 1283 | /** |
| 1284 | Helper function to convert a UINT64 value in binary to a string. |
| 1285 | |
| 1286 | @param[in] Value Value of a UINT64 integer. |
| 1287 | @param[out] BinString String buffer to contain the conversion result. |
| 1288 | |
| 1289 | @return VOID. |
| 1290 | **/ |
| 1291 | VOID |
| 1292 | Uint64ToBinString ( |
| 1293 | IN UINT64 Value, |
| 1294 | OUT CHAR8 *BinString |
| 1295 | ) |
| 1296 | { |
| 1297 | UINTN Index; |
| 1298 | |
| 1299 | if (BinString == NULL) { |
| 1300 | return; |
| 1301 | } |
| 1302 | |
| 1303 | for (Index = 64; Index > 0; --Index) { |
| 1304 | BinString[Index - 1] = '0' + (Value & 1); |
| 1305 | Value = RShiftU64 (Value, 1); |
| 1306 | } |
| 1307 | BinString[64] = '\0'; |
| 1308 | } |
| 1309 | |
| 1310 | /** |
| 1311 | Dump the guarded memory bit map. |
| 1312 | **/ |
| 1313 | VOID |
| 1314 | EFIAPI |
| 1315 | DumpGuardedMemoryBitmap ( |
| 1316 | VOID |
| 1317 | ) |
| 1318 | { |
| 1319 | UINTN Entries[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1320 | UINTN Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1321 | UINTN Indices[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1322 | UINT64 Tables[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1323 | UINT64 Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH]; |
| 1324 | UINT64 TableEntry; |
| 1325 | UINT64 Address; |
| 1326 | INTN Level; |
| 1327 | UINTN RepeatZero; |
| 1328 | CHAR8 String[GUARDED_HEAP_MAP_ENTRY_BITS + 1]; |
| 1329 | CHAR8 *Ruler1; |
| 1330 | CHAR8 *Ruler2; |
| 1331 | |
| 1332 | if (mGuardedMemoryMap == 0) { |
| 1333 | return; |
| 1334 | } |
| 1335 | |
| 1336 | Ruler1 = " 3 2 1 0"; |
| 1337 | Ruler2 = "FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210"; |
| 1338 | |
| 1339 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "=============================" |
| 1340 | " Guarded Memory Bitmap " |
| 1341 | "==============================\r\n")); |
| 1342 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, " %a\r\n", Ruler1)); |
| 1343 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, " %a\r\n", Ruler2)); |
| 1344 | |
| 1345 | CopyMem (Entries, mLevelMask, sizeof (Entries)); |
| 1346 | CopyMem (Shifts, mLevelShift, sizeof (Shifts)); |
| 1347 | |
| 1348 | SetMem (Indices, sizeof(Indices), 0); |
| 1349 | SetMem (Tables, sizeof(Tables), 0); |
| 1350 | SetMem (Addresses, sizeof(Addresses), 0); |
| 1351 | |
| 1352 | Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel; |
| 1353 | Tables[Level] = mGuardedMemoryMap; |
| 1354 | Address = 0; |
| 1355 | RepeatZero = 0; |
| 1356 | |
| 1357 | while (TRUE) { |
| 1358 | if (Indices[Level] > Entries[Level]) { |
| 1359 | |
| 1360 | Tables[Level] = 0; |
| 1361 | Level -= 1; |
| 1362 | RepeatZero = 0; |
| 1363 | |
| 1364 | DEBUG (( |
| 1365 | HEAP_GUARD_DEBUG_LEVEL, |
| 1366 | "=========================================" |
| 1367 | "=========================================\r\n" |
| 1368 | )); |
| 1369 | |
| 1370 | } else { |
| 1371 | |
| 1372 | TableEntry = ((UINT64 *)(UINTN)Tables[Level])[Indices[Level]]; |
| 1373 | Address = Addresses[Level]; |
| 1374 | |
| 1375 | if (TableEntry == 0) { |
| 1376 | |
| 1377 | if (Level == GUARDED_HEAP_MAP_TABLE_DEPTH - 1) { |
| 1378 | if (RepeatZero == 0) { |
| 1379 | Uint64ToBinString(TableEntry, String); |
| 1380 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String)); |
| 1381 | } else if (RepeatZero == 1) { |
| 1382 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "... : ...\r\n")); |
| 1383 | } |
| 1384 | RepeatZero += 1; |
| 1385 | } |
| 1386 | |
| 1387 | } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) { |
| 1388 | |
| 1389 | Level += 1; |
| 1390 | Tables[Level] = TableEntry; |
| 1391 | Addresses[Level] = Address; |
| 1392 | Indices[Level] = 0; |
| 1393 | RepeatZero = 0; |
| 1394 | |
| 1395 | continue; |
| 1396 | |
| 1397 | } else { |
| 1398 | |
| 1399 | RepeatZero = 0; |
| 1400 | Uint64ToBinString(TableEntry, String); |
| 1401 | DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String)); |
| 1402 | |
| 1403 | } |
| 1404 | } |
| 1405 | |
| 1406 | if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) { |
| 1407 | break; |
| 1408 | } |
| 1409 | |
| 1410 | Indices[Level] += 1; |
| 1411 | Address = (Level == 0) ? 0 : Addresses[Level - 1]; |
| 1412 | Addresses[Level] = Address | LShiftU64(Indices[Level], Shifts[Level]); |
| 1413 | |
| 1414 | } |
| 1415 | } |
| 1416 | |
| 1417 | /** |
| 1418 | Debug function used to verify if the Guard page is well set or not. |
| 1419 | |
| 1420 | @param[in] BaseAddress Address of memory to check. |
| 1421 | @param[in] NumberOfPages Size of memory in pages. |
| 1422 | |
| 1423 | @return TRUE The head Guard and tail Guard are both well set. |
| 1424 | @return FALSE The head Guard and/or tail Guard are not well set. |
| 1425 | **/ |
| 1426 | BOOLEAN |
| 1427 | VerifyMemoryGuard ( |
| 1428 | IN EFI_PHYSICAL_ADDRESS BaseAddress, |
| 1429 | IN UINTN NumberOfPages |
| 1430 | ) |
| 1431 | { |
| 1432 | EFI_STATUS Status; |
| 1433 | UINT64 Attribute; |
| 1434 | EFI_PHYSICAL_ADDRESS Address; |
| 1435 | |
| 1436 | if (mSmmMemoryAttribute == NULL) { |
| 1437 | return TRUE; |
| 1438 | } |
| 1439 | |
| 1440 | Attribute = 0; |
| 1441 | Address = BaseAddress - EFI_PAGE_SIZE; |
| 1442 | Status = mSmmMemoryAttribute->GetMemoryAttributes ( |
| 1443 | mSmmMemoryAttribute, |
| 1444 | Address, |
| 1445 | EFI_PAGE_SIZE, |
| 1446 | &Attribute |
| 1447 | ); |
| 1448 | if (EFI_ERROR (Status) || (Attribute & EFI_MEMORY_RP) == 0) { |
| 1449 | DEBUG ((DEBUG_ERROR, "Head Guard is not set at: %016lx (%016lX)!!!\r\n", |
| 1450 | Address, Attribute)); |
| 1451 | DumpGuardedMemoryBitmap (); |
| 1452 | return FALSE; |
| 1453 | } |
| 1454 | |
| 1455 | Attribute = 0; |
| 1456 | Address = BaseAddress + EFI_PAGES_TO_SIZE (NumberOfPages); |
| 1457 | Status = mSmmMemoryAttribute->GetMemoryAttributes ( |
| 1458 | mSmmMemoryAttribute, |
| 1459 | Address, |
| 1460 | EFI_PAGE_SIZE, |
| 1461 | &Attribute |
| 1462 | ); |
| 1463 | if (EFI_ERROR (Status) || (Attribute & EFI_MEMORY_RP) == 0) { |
| 1464 | DEBUG ((DEBUG_ERROR, "Tail Guard is not set at: %016lx (%016lX)!!!\r\n", |
| 1465 | Address, Attribute)); |
| 1466 | DumpGuardedMemoryBitmap (); |
| 1467 | return FALSE; |
| 1468 | } |
| 1469 | |
| 1470 | return TRUE; |
| 1471 | } |
| 1472 | |