923af93de247d6788958e82701555ca63b9ba5e7
[mirror_edk2.git] / MdeModulePkg / Core / PiSmmCore / HeapGuard.c
1 /** @file
2 UEFI Heap Guard functions.
3
4 Copyright (c) 2017-2018, 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 (AllocMapUnit &&
255 mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH &&
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 UINT64 GuardBitmap;
780
781 if (NumberOfPages == 0) {
782 return;
783 }
784
785 //
786 // Head Guard must be one page before, if any.
787 //
788 // MSB-> 1 0 <-LSB
789 // -------------------
790 // Head Guard -> 0 1 -> Don't free Head Guard (shared Guard)
791 // Head Guard -> 0 0 -> Free Head Guard either (not shared Guard)
792 // 1 X -> Don't free first page (need a new Guard)
793 // (it'll be turned into a Guard page later)
794 // -------------------
795 // Start -> -1 -2
796 //
797 GuardPage = Memory - EFI_PAGES_TO_SIZE (1);
798 GuardBitmap = GetGuardedMemoryBits (Memory - EFI_PAGES_TO_SIZE (2), 2);
799 if ((GuardBitmap & BIT1) == 0) {
800 //
801 // Head Guard exists.
802 //
803 if ((GuardBitmap & BIT0) == 0) {
804 //
805 // If the head Guard is not a tail Guard of adjacent memory block,
806 // unset it.
807 //
808 UnsetGuardPage (GuardPage);
809 }
810 } else {
811 //
812 // Pages before memory to free are still in Guard. It's a partial free
813 // case. Turn first page of memory block to free into a new Guard.
814 //
815 SetGuardPage (Memory);
816 }
817
818 //
819 // Tail Guard must be the page after this memory block to free, if any.
820 //
821 // MSB-> 1 0 <-LSB
822 // --------------------
823 // 1 0 <- Tail Guard -> Don't free Tail Guard (shared Guard)
824 // 0 0 <- Tail Guard -> Free Tail Guard either (not shared Guard)
825 // X 1 -> Don't free last page (need a new Guard)
826 // (it'll be turned into a Guard page later)
827 // --------------------
828 // +1 +0 <- End
829 //
830 GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);
831 GuardBitmap = GetGuardedMemoryBits (GuardPage, 2);
832 if ((GuardBitmap & BIT0) == 0) {
833 //
834 // Tail Guard exists.
835 //
836 if ((GuardBitmap & BIT1) == 0) {
837 //
838 // If the tail Guard is not a head Guard of adjacent memory block,
839 // free it; otherwise, keep it.
840 //
841 UnsetGuardPage (GuardPage);
842 }
843 } else {
844 //
845 // Pages after memory to free are still in Guard. It's a partial free
846 // case. We need to keep one page to be a head Guard.
847 //
848 SetGuardPage (GuardPage - EFI_PAGES_TO_SIZE (1));
849 }
850
851 //
852 // No matter what, we just clear the mark of the Guarded memory.
853 //
854 ClearGuardedMemoryBits(Memory, NumberOfPages);
855 }
856
857 /**
858 Adjust address of free memory according to existing and/or required Guard.
859
860 This function will check if there're existing Guard pages of adjacent
861 memory blocks, and try to use it as the Guard page of the memory to be
862 allocated.
863
864 @param[in] Start Start address of free memory block.
865 @param[in] Size Size of free memory block.
866 @param[in] SizeRequested Size of memory to allocate.
867
868 @return The end address of memory block found.
869 @return 0 if no enough space for the required size of memory and its Guard.
870 **/
871 UINT64
872 AdjustMemoryS (
873 IN UINT64 Start,
874 IN UINT64 Size,
875 IN UINT64 SizeRequested
876 )
877 {
878 UINT64 Target;
879
880 //
881 // UEFI spec requires that allocated pool must be 8-byte aligned. If it's
882 // indicated to put the pool near the Tail Guard, we need extra bytes to
883 // make sure alignment of the returned pool address.
884 //
885 if ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) == 0) {
886 SizeRequested = ALIGN_VALUE(SizeRequested, 8);
887 }
888
889 Target = Start + Size - SizeRequested;
890 ASSERT (Target >= Start);
891 if (Target == 0) {
892 return 0;
893 }
894
895 if (!IsGuardPage (Start + Size)) {
896 // No Guard at tail to share. One more page is needed.
897 Target -= EFI_PAGES_TO_SIZE (1);
898 }
899
900 // Out of range?
901 if (Target < Start) {
902 return 0;
903 }
904
905 // At the edge?
906 if (Target == Start) {
907 if (!IsGuardPage (Target - EFI_PAGES_TO_SIZE (1))) {
908 // No enough space for a new head Guard if no Guard at head to share.
909 return 0;
910 }
911 }
912
913 // OK, we have enough pages for memory and its Guards. Return the End of the
914 // free space.
915 return Target + SizeRequested - 1;
916 }
917
918 /**
919 Adjust the start address and number of pages to free according to Guard.
920
921 The purpose of this function is to keep the shared Guard page with adjacent
922 memory block if it's still in guard, or free it if no more sharing. Another
923 is to reserve pages as Guard pages in partial page free situation.
924
925 @param[in,out] Memory Base address of memory to free.
926 @param[in,out] NumberOfPages Size of memory to free.
927
928 @return VOID.
929 **/
930 VOID
931 AdjustMemoryF (
932 IN OUT EFI_PHYSICAL_ADDRESS *Memory,
933 IN OUT UINTN *NumberOfPages
934 )
935 {
936 EFI_PHYSICAL_ADDRESS Start;
937 EFI_PHYSICAL_ADDRESS MemoryToTest;
938 UINTN PagesToFree;
939 UINT64 GuardBitmap;
940
941 if (Memory == NULL || NumberOfPages == NULL || *NumberOfPages == 0) {
942 return;
943 }
944
945 Start = *Memory;
946 PagesToFree = *NumberOfPages;
947
948 //
949 // Head Guard must be one page before, if any.
950 //
951 // MSB-> 1 0 <-LSB
952 // -------------------
953 // Head Guard -> 0 1 -> Don't free Head Guard (shared Guard)
954 // Head Guard -> 0 0 -> Free Head Guard either (not shared Guard)
955 // 1 X -> Don't free first page (need a new Guard)
956 // (it'll be turned into a Guard page later)
957 // -------------------
958 // Start -> -1 -2
959 //
960 MemoryToTest = Start - EFI_PAGES_TO_SIZE (2);
961 GuardBitmap = GetGuardedMemoryBits (MemoryToTest, 2);
962 if ((GuardBitmap & BIT1) == 0) {
963 //
964 // Head Guard exists.
965 //
966 if ((GuardBitmap & BIT0) == 0) {
967 //
968 // If the head Guard is not a tail Guard of adjacent memory block,
969 // free it; otherwise, keep it.
970 //
971 Start -= EFI_PAGES_TO_SIZE (1);
972 PagesToFree += 1;
973 }
974 } else {
975 //
976 // No Head Guard, and pages before memory to free are still in Guard. It's a
977 // partial free case. We need to keep one page to be a tail Guard.
978 //
979 Start += EFI_PAGES_TO_SIZE (1);
980 PagesToFree -= 1;
981 }
982
983 //
984 // Tail Guard must be the page after this memory block to free, if any.
985 //
986 // MSB-> 1 0 <-LSB
987 // --------------------
988 // 1 0 <- Tail Guard -> Don't free Tail Guard (shared Guard)
989 // 0 0 <- Tail Guard -> Free Tail Guard either (not shared Guard)
990 // X 1 -> Don't free last page (need a new Guard)
991 // (it'll be turned into a Guard page later)
992 // --------------------
993 // +1 +0 <- End
994 //
995 MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree);
996 GuardBitmap = GetGuardedMemoryBits (MemoryToTest, 2);
997 if ((GuardBitmap & BIT0) == 0) {
998 //
999 // Tail Guard exists.
1000 //
1001 if ((GuardBitmap & BIT1) == 0) {
1002 //
1003 // If the tail Guard is not a head Guard of adjacent memory block,
1004 // free it; otherwise, keep it.
1005 //
1006 PagesToFree += 1;
1007 }
1008 } else if (PagesToFree > 0) {
1009 //
1010 // No Tail Guard, and pages after memory to free are still in Guard. It's a
1011 // partial free case. We need to keep one page to be a head Guard.
1012 //
1013 PagesToFree -= 1;
1014 }
1015
1016 *Memory = Start;
1017 *NumberOfPages = PagesToFree;
1018 }
1019
1020 /**
1021 Adjust the base and number of pages to really allocate according to Guard.
1022
1023 @param[in,out] Memory Base address of free memory.
1024 @param[in,out] NumberOfPages Size of memory to allocate.
1025
1026 @return VOID.
1027 **/
1028 VOID
1029 AdjustMemoryA (
1030 IN OUT EFI_PHYSICAL_ADDRESS *Memory,
1031 IN OUT UINTN *NumberOfPages
1032 )
1033 {
1034 //
1035 // FindFreePages() has already taken the Guard into account. It's safe to
1036 // adjust the start address and/or number of pages here, to make sure that
1037 // the Guards are also "allocated".
1038 //
1039 if (!IsGuardPage (*Memory + EFI_PAGES_TO_SIZE (*NumberOfPages))) {
1040 // No tail Guard, add one.
1041 *NumberOfPages += 1;
1042 }
1043
1044 if (!IsGuardPage (*Memory - EFI_PAGE_SIZE)) {
1045 // No head Guard, add one.
1046 *Memory -= EFI_PAGE_SIZE;
1047 *NumberOfPages += 1;
1048 }
1049 }
1050
1051 /**
1052 Adjust the pool head position to make sure the Guard page is adjavent to
1053 pool tail or pool head.
1054
1055 @param[in] Memory Base address of memory allocated.
1056 @param[in] NoPages Number of pages actually allocated.
1057 @param[in] Size Size of memory requested.
1058 (plus pool head/tail overhead)
1059
1060 @return Address of pool head
1061 **/
1062 VOID *
1063 AdjustPoolHeadA (
1064 IN EFI_PHYSICAL_ADDRESS Memory,
1065 IN UINTN NoPages,
1066 IN UINTN Size
1067 )
1068 {
1069 if (Memory == 0 || (PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0) {
1070 //
1071 // Pool head is put near the head Guard
1072 //
1073 return (VOID *)(UINTN)Memory;
1074 }
1075
1076 //
1077 // Pool head is put near the tail Guard
1078 //
1079 Size = ALIGN_VALUE (Size, 8);
1080 return (VOID *)(UINTN)(Memory + EFI_PAGES_TO_SIZE (NoPages) - Size);
1081 }
1082
1083 /**
1084 Get the page base address according to pool head address.
1085
1086 @param[in] Memory Head address of pool to free.
1087
1088 @return Address of pool head.
1089 **/
1090 VOID *
1091 AdjustPoolHeadF (
1092 IN EFI_PHYSICAL_ADDRESS Memory
1093 )
1094 {
1095 if (Memory == 0 || (PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0) {
1096 //
1097 // Pool head is put near the head Guard
1098 //
1099 return (VOID *)(UINTN)Memory;
1100 }
1101
1102 //
1103 // Pool head is put near the tail Guard
1104 //
1105 return (VOID *)(UINTN)(Memory & ~EFI_PAGE_MASK);
1106 }
1107
1108 /**
1109 Helper function of memory allocation with Guard pages.
1110
1111 @param FreePageList The free page node.
1112 @param NumberOfPages Number of pages to be allocated.
1113 @param MaxAddress Request to allocate memory below this address.
1114 @param MemoryType Type of memory requested.
1115
1116 @return Memory address of allocated pages.
1117 **/
1118 UINTN
1119 InternalAllocMaxAddressWithGuard (
1120 IN OUT LIST_ENTRY *FreePageList,
1121 IN UINTN NumberOfPages,
1122 IN UINTN MaxAddress,
1123 IN EFI_MEMORY_TYPE MemoryType
1124
1125 )
1126 {
1127 LIST_ENTRY *Node;
1128 FREE_PAGE_LIST *Pages;
1129 UINTN PagesToAlloc;
1130 UINTN HeadGuard;
1131 UINTN TailGuard;
1132 UINTN Address;
1133
1134 for (Node = FreePageList->BackLink; Node != FreePageList;
1135 Node = Node->BackLink) {
1136 Pages = BASE_CR (Node, FREE_PAGE_LIST, Link);
1137 if (Pages->NumberOfPages >= NumberOfPages &&
1138 (UINTN)Pages + EFI_PAGES_TO_SIZE (NumberOfPages) - 1 <= MaxAddress) {
1139
1140 //
1141 // We may need 1 or 2 more pages for Guard. Check it out.
1142 //
1143 PagesToAlloc = NumberOfPages;
1144 TailGuard = (UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages);
1145 if (!IsGuardPage (TailGuard)) {
1146 //
1147 // Add one if no Guard at the end of current free memory block.
1148 //
1149 PagesToAlloc += 1;
1150 TailGuard = 0;
1151 }
1152
1153 HeadGuard = (UINTN)Pages +
1154 EFI_PAGES_TO_SIZE (Pages->NumberOfPages - PagesToAlloc) -
1155 EFI_PAGE_SIZE;
1156 if (!IsGuardPage (HeadGuard)) {
1157 //
1158 // Add one if no Guard at the page before the address to allocate
1159 //
1160 PagesToAlloc += 1;
1161 HeadGuard = 0;
1162 }
1163
1164 if (Pages->NumberOfPages < PagesToAlloc) {
1165 // Not enough space to allocate memory with Guards? Try next block.
1166 continue;
1167 }
1168
1169 Address = InternalAllocPagesOnOneNode (Pages, PagesToAlloc, MaxAddress);
1170 ConvertSmmMemoryMapEntry(MemoryType, Address, PagesToAlloc, FALSE);
1171 CoreFreeMemoryMapStack();
1172 if (HeadGuard == 0) {
1173 // Don't pass the Guard page to user.
1174 Address += EFI_PAGE_SIZE;
1175 }
1176 SetGuardForMemory (Address, NumberOfPages);
1177 return Address;
1178 }
1179 }
1180
1181 return (UINTN)(-1);
1182 }
1183
1184 /**
1185 Helper function of memory free with Guard pages.
1186
1187 @param[in] Memory Base address of memory being freed.
1188 @param[in] NumberOfPages The number of pages to free.
1189 @param[in] AddRegion If this memory is new added region.
1190
1191 @retval EFI_NOT_FOUND Could not find the entry that covers the range.
1192 @retval EFI_INVALID_PARAMETER Address not aligned, Address is zero or NumberOfPages is zero.
1193 @return EFI_SUCCESS Pages successfully freed.
1194 **/
1195 EFI_STATUS
1196 SmmInternalFreePagesExWithGuard (
1197 IN EFI_PHYSICAL_ADDRESS Memory,
1198 IN UINTN NumberOfPages,
1199 IN BOOLEAN AddRegion
1200 )
1201 {
1202 EFI_PHYSICAL_ADDRESS MemoryToFree;
1203 UINTN PagesToFree;
1204
1205 if (((Memory & EFI_PAGE_MASK) != 0) || (Memory == 0) || (NumberOfPages == 0)) {
1206 return EFI_INVALID_PARAMETER;
1207 }
1208
1209 MemoryToFree = Memory;
1210 PagesToFree = NumberOfPages;
1211
1212 AdjustMemoryF (&MemoryToFree, &PagesToFree);
1213 UnsetGuardForMemory (Memory, NumberOfPages);
1214 if (PagesToFree == 0) {
1215 return EFI_SUCCESS;
1216 }
1217
1218 return SmmInternalFreePagesEx (MemoryToFree, PagesToFree, AddRegion);
1219 }
1220
1221 /**
1222 Set all Guard pages which cannot be set during the non-SMM mode time.
1223 **/
1224 VOID
1225 SetAllGuardPages (
1226 VOID
1227 )
1228 {
1229 UINTN Entries[GUARDED_HEAP_MAP_TABLE_DEPTH];
1230 UINTN Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH];
1231 UINTN Indices[GUARDED_HEAP_MAP_TABLE_DEPTH];
1232 UINT64 Tables[GUARDED_HEAP_MAP_TABLE_DEPTH];
1233 UINT64 Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH];
1234 UINT64 TableEntry;
1235 UINT64 Address;
1236 UINT64 GuardPage;
1237 INTN Level;
1238 UINTN Index;
1239 BOOLEAN OnGuarding;
1240
1241 if (mGuardedMemoryMap == 0 ||
1242 mMapLevel == 0 ||
1243 mMapLevel > GUARDED_HEAP_MAP_TABLE_DEPTH) {
1244 return;
1245 }
1246
1247 CopyMem (Entries, mLevelMask, sizeof (Entries));
1248 CopyMem (Shifts, mLevelShift, sizeof (Shifts));
1249
1250 SetMem (Tables, sizeof(Tables), 0);
1251 SetMem (Addresses, sizeof(Addresses), 0);
1252 SetMem (Indices, sizeof(Indices), 0);
1253
1254 Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;
1255 Tables[Level] = mGuardedMemoryMap;
1256 Address = 0;
1257 OnGuarding = FALSE;
1258
1259 DEBUG_CODE (
1260 DumpGuardedMemoryBitmap ();
1261 );
1262
1263 while (TRUE) {
1264 if (Indices[Level] > Entries[Level]) {
1265 Tables[Level] = 0;
1266 Level -= 1;
1267 } else {
1268
1269 TableEntry = ((UINT64 *)(UINTN)(Tables[Level]))[Indices[Level]];
1270 Address = Addresses[Level];
1271
1272 if (TableEntry == 0) {
1273
1274 OnGuarding = FALSE;
1275
1276 } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {
1277
1278 Level += 1;
1279 Tables[Level] = TableEntry;
1280 Addresses[Level] = Address;
1281 Indices[Level] = 0;
1282
1283 continue;
1284
1285 } else {
1286
1287 Index = 0;
1288 while (Index < GUARDED_HEAP_MAP_ENTRY_BITS) {
1289 if ((TableEntry & 1) == 1) {
1290 if (OnGuarding) {
1291 GuardPage = 0;
1292 } else {
1293 GuardPage = Address - EFI_PAGE_SIZE;
1294 }
1295 OnGuarding = TRUE;
1296 } else {
1297 if (OnGuarding) {
1298 GuardPage = Address;
1299 } else {
1300 GuardPage = 0;
1301 }
1302 OnGuarding = FALSE;
1303 }
1304
1305 if (GuardPage != 0) {
1306 SetGuardPage (GuardPage);
1307 }
1308
1309 if (TableEntry == 0) {
1310 break;
1311 }
1312
1313 TableEntry = RShiftU64 (TableEntry, 1);
1314 Address += EFI_PAGE_SIZE;
1315 Index += 1;
1316 }
1317 }
1318 }
1319
1320 if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) {
1321 break;
1322 }
1323
1324 Indices[Level] += 1;
1325 Address = (Level == 0) ? 0 : Addresses[Level - 1];
1326 Addresses[Level] = Address | LShiftU64(Indices[Level], Shifts[Level]);
1327
1328 }
1329 }
1330
1331 /**
1332 Hook function used to set all Guard pages after entering SMM mode.
1333 **/
1334 VOID
1335 SmmEntryPointMemoryManagementHook (
1336 VOID
1337 )
1338 {
1339 EFI_STATUS Status;
1340
1341 if (mSmmMemoryAttribute == NULL) {
1342 Status = SmmLocateProtocol (
1343 &gEdkiiSmmMemoryAttributeProtocolGuid,
1344 NULL,
1345 (VOID **)&mSmmMemoryAttribute
1346 );
1347 if (!EFI_ERROR(Status)) {
1348 SetAllGuardPages ();
1349 }
1350 }
1351 }
1352
1353 /**
1354 Helper function to convert a UINT64 value in binary to a string.
1355
1356 @param[in] Value Value of a UINT64 integer.
1357 @param[out] BinString String buffer to contain the conversion result.
1358
1359 @return VOID.
1360 **/
1361 VOID
1362 Uint64ToBinString (
1363 IN UINT64 Value,
1364 OUT CHAR8 *BinString
1365 )
1366 {
1367 UINTN Index;
1368
1369 if (BinString == NULL) {
1370 return;
1371 }
1372
1373 for (Index = 64; Index > 0; --Index) {
1374 BinString[Index - 1] = '0' + (Value & 1);
1375 Value = RShiftU64 (Value, 1);
1376 }
1377 BinString[64] = '\0';
1378 }
1379
1380 /**
1381 Dump the guarded memory bit map.
1382 **/
1383 VOID
1384 EFIAPI
1385 DumpGuardedMemoryBitmap (
1386 VOID
1387 )
1388 {
1389 UINTN Entries[GUARDED_HEAP_MAP_TABLE_DEPTH];
1390 UINTN Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH];
1391 UINTN Indices[GUARDED_HEAP_MAP_TABLE_DEPTH];
1392 UINT64 Tables[GUARDED_HEAP_MAP_TABLE_DEPTH];
1393 UINT64 Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH];
1394 UINT64 TableEntry;
1395 UINT64 Address;
1396 INTN Level;
1397 UINTN RepeatZero;
1398 CHAR8 String[GUARDED_HEAP_MAP_ENTRY_BITS + 1];
1399 CHAR8 *Ruler1;
1400 CHAR8 *Ruler2;
1401
1402 if (mGuardedMemoryMap == 0 ||
1403 mMapLevel == 0 ||
1404 mMapLevel > GUARDED_HEAP_MAP_TABLE_DEPTH) {
1405 return;
1406 }
1407
1408 Ruler1 = " 3 2 1 0";
1409 Ruler2 = "FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210";
1410
1411 DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "============================="
1412 " Guarded Memory Bitmap "
1413 "==============================\r\n"));
1414 DEBUG ((HEAP_GUARD_DEBUG_LEVEL, " %a\r\n", Ruler1));
1415 DEBUG ((HEAP_GUARD_DEBUG_LEVEL, " %a\r\n", Ruler2));
1416
1417 CopyMem (Entries, mLevelMask, sizeof (Entries));
1418 CopyMem (Shifts, mLevelShift, sizeof (Shifts));
1419
1420 SetMem (Indices, sizeof(Indices), 0);
1421 SetMem (Tables, sizeof(Tables), 0);
1422 SetMem (Addresses, sizeof(Addresses), 0);
1423
1424 Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;
1425 Tables[Level] = mGuardedMemoryMap;
1426 Address = 0;
1427 RepeatZero = 0;
1428
1429 while (TRUE) {
1430 if (Indices[Level] > Entries[Level]) {
1431
1432 Tables[Level] = 0;
1433 Level -= 1;
1434 RepeatZero = 0;
1435
1436 DEBUG ((
1437 HEAP_GUARD_DEBUG_LEVEL,
1438 "========================================="
1439 "=========================================\r\n"
1440 ));
1441
1442 } else {
1443
1444 TableEntry = ((UINT64 *)(UINTN)Tables[Level])[Indices[Level]];
1445 Address = Addresses[Level];
1446
1447 if (TableEntry == 0) {
1448
1449 if (Level == GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {
1450 if (RepeatZero == 0) {
1451 Uint64ToBinString(TableEntry, String);
1452 DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String));
1453 } else if (RepeatZero == 1) {
1454 DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "... : ...\r\n"));
1455 }
1456 RepeatZero += 1;
1457 }
1458
1459 } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {
1460
1461 Level += 1;
1462 Tables[Level] = TableEntry;
1463 Addresses[Level] = Address;
1464 Indices[Level] = 0;
1465 RepeatZero = 0;
1466
1467 continue;
1468
1469 } else {
1470
1471 RepeatZero = 0;
1472 Uint64ToBinString(TableEntry, String);
1473 DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String));
1474
1475 }
1476 }
1477
1478 if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) {
1479 break;
1480 }
1481
1482 Indices[Level] += 1;
1483 Address = (Level == 0) ? 0 : Addresses[Level - 1];
1484 Addresses[Level] = Address | LShiftU64(Indices[Level], Shifts[Level]);
1485
1486 }
1487 }
1488
1489 /**
1490 Debug function used to verify if the Guard page is well set or not.
1491
1492 @param[in] BaseAddress Address of memory to check.
1493 @param[in] NumberOfPages Size of memory in pages.
1494
1495 @return TRUE The head Guard and tail Guard are both well set.
1496 @return FALSE The head Guard and/or tail Guard are not well set.
1497 **/
1498 BOOLEAN
1499 VerifyMemoryGuard (
1500 IN EFI_PHYSICAL_ADDRESS BaseAddress,
1501 IN UINTN NumberOfPages
1502 )
1503 {
1504 EFI_STATUS Status;
1505 UINT64 Attribute;
1506 EFI_PHYSICAL_ADDRESS Address;
1507
1508 if (mSmmMemoryAttribute == NULL) {
1509 return TRUE;
1510 }
1511
1512 Attribute = 0;
1513 Address = BaseAddress - EFI_PAGE_SIZE;
1514 Status = mSmmMemoryAttribute->GetMemoryAttributes (
1515 mSmmMemoryAttribute,
1516 Address,
1517 EFI_PAGE_SIZE,
1518 &Attribute
1519 );
1520 if (EFI_ERROR (Status) || (Attribute & EFI_MEMORY_RP) == 0) {
1521 DEBUG ((DEBUG_ERROR, "Head Guard is not set at: %016lx (%016lX)!!!\r\n",
1522 Address, Attribute));
1523 DumpGuardedMemoryBitmap ();
1524 return FALSE;
1525 }
1526
1527 Attribute = 0;
1528 Address = BaseAddress + EFI_PAGES_TO_SIZE (NumberOfPages);
1529 Status = mSmmMemoryAttribute->GetMemoryAttributes (
1530 mSmmMemoryAttribute,
1531 Address,
1532 EFI_PAGE_SIZE,
1533 &Attribute
1534 );
1535 if (EFI_ERROR (Status) || (Attribute & EFI_MEMORY_RP) == 0) {
1536 DEBUG ((DEBUG_ERROR, "Tail Guard is not set at: %016lx (%016lX)!!!\r\n",
1537 Address, Attribute));
1538 DumpGuardedMemoryBitmap ();
1539 return FALSE;
1540 }
1541
1542 return TRUE;
1543 }
1544