2 UEFI Heap Guard functions.
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
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.
15 #include "HeapGuard.h"
18 // Global to avoid infinite reentrance of memory allocation when updating
19 // page table attributes, which may need allocating pages for new PDE/PTE.
21 GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN mOnGuarding
= FALSE
;
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.
28 GLOBAL_REMOVE_IF_UNREFERENCED UINT64 mGuardedMemoryMap
= 0;
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.
35 GLOBAL_REMOVE_IF_UNREFERENCED UINTN mMapLevel
= 1;
38 // Shift and mask for each level of map table
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
;
46 // SMM memory attribute protocol
48 EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL
*mSmmMemoryAttribute
= NULL
;
51 Set corresponding bits in bitmap table to 1 according to the address.
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.
62 IN EFI_PHYSICAL_ADDRESS Address
,
73 StartBit
= (UINTN
)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address
);
74 EndBit
= (StartBit
+ BitNumber
- 1) % GUARDED_HEAP_MAP_ENTRY_BITS
;
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
;
88 *BitMap
|= LShiftU64 (LShiftU64 (1, Msbs
) - 1, StartBit
);
93 SetMem64 ((VOID
*)BitMap
, Qwords
* GUARDED_HEAP_MAP_ENTRY_BYTES
,
99 *BitMap
|= (LShiftU64 (1, Lsbs
) - 1);
104 Set corresponding bits in bitmap table to 0 according to the address.
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.
115 IN EFI_PHYSICAL_ADDRESS Address
,
126 StartBit
= (UINTN
)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address
);
127 EndBit
= (StartBit
+ BitNumber
- 1) % GUARDED_HEAP_MAP_ENTRY_BITS
;
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
;
141 *BitMap
&= ~LShiftU64 (LShiftU64 (1, Msbs
) - 1, StartBit
);
146 SetMem64 ((VOID
*)BitMap
, Qwords
* GUARDED_HEAP_MAP_ENTRY_BYTES
, 0);
151 *BitMap
&= ~(LShiftU64 (1, Lsbs
) - 1);
156 Get corresponding bits in bitmap table according to the address.
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.
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.
165 @return An integer containing the bits information.
170 IN EFI_PHYSICAL_ADDRESS Address
,
181 ASSERT (BitNumber
<= GUARDED_HEAP_MAP_ENTRY_BITS
);
183 StartBit
= (UINTN
)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address
);
184 EndBit
= (StartBit
+ BitNumber
- 1) % GUARDED_HEAP_MAP_ENTRY_BITS
;
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
;
194 Result
= RShiftU64 ((*BitMap
), StartBit
) & (LShiftU64 (1, Msbs
) - 1);
197 Result
|= LShiftU64 ((*BitMap
) & (LShiftU64 (1, Lsbs
) - 1), Msbs
);
204 Helper function to allocate pages without Guard for internal uses.
206 @param[in] Pages Page number.
208 @return Address of memory allocated.
216 EFI_PHYSICAL_ADDRESS Memory
;
218 Status
= SmmInternalAllocatePages (AllocateAnyPages
, EfiRuntimeServicesData
,
219 Pages
, &Memory
, FALSE
);
220 if (EFI_ERROR (Status
)) {
224 return (VOID
*)(UINTN
)Memory
;
228 Locate the pointer of bitmap from the guarded memory bitmap tables, which
229 covers the given Address.
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.
235 @return The bit number from given Address to the end of current map table.
238 FindGuardedMemoryMap (
239 IN EFI_PHYSICAL_ADDRESS Address
,
240 IN BOOLEAN AllocMapUnit
,
252 // Adjust current map table depth according to the address to access
254 while (mMapLevel
< GUARDED_HEAP_MAP_TABLE_DEPTH
258 mLevelShift
[GUARDED_HEAP_MAP_TABLE_DEPTH
- mMapLevel
- 1]
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);
267 SetMem ((VOID
*)(UINTN
)MapMemory
, Size
, 0);
269 *(UINT64
*)(UINTN
)MapMemory
= mGuardedMemoryMap
;
270 mGuardedMemoryMap
= MapMemory
;
277 GuardMap
= &mGuardedMemoryMap
;
278 for (Level
= GUARDED_HEAP_MAP_TABLE_DEPTH
- mMapLevel
;
279 Level
< GUARDED_HEAP_MAP_TABLE_DEPTH
;
282 if (*GuardMap
== 0) {
288 Size
= (mLevelMask
[Level
] + 1) * GUARDED_HEAP_MAP_ENTRY_BYTES
;
289 MapMemory
= (UINT64
)(UINTN
)PageAlloc (EFI_SIZE_TO_PAGES (Size
));
290 ASSERT (MapMemory
!= 0);
292 SetMem ((VOID
*)(UINTN
)MapMemory
, Size
, 0);
293 *GuardMap
= MapMemory
;
296 Index
= (UINTN
)RShiftU64 (Address
, mLevelShift
[Level
]);
297 Index
&= mLevelMask
[Level
];
298 GuardMap
= (UINT64
*)(UINTN
)((*GuardMap
) + Index
* sizeof (UINT64
));
302 BitsToUnitEnd
= GUARDED_HEAP_MAP_BITS
- GUARDED_HEAP_MAP_BIT_INDEX (Address
);
305 return BitsToUnitEnd
;
309 Set corresponding bits in bitmap table to 1 according to given memory range.
311 @param[in] Address Memory address to guard from.
312 @param[in] NumberOfPages Number of pages to guard.
318 SetGuardedMemoryBits (
319 IN EFI_PHYSICAL_ADDRESS Address
,
320 IN UINTN NumberOfPages
327 while (NumberOfPages
> 0) {
328 BitsToUnitEnd
= FindGuardedMemoryMap (Address
, TRUE
, &BitMap
);
329 ASSERT (BitMap
!= NULL
);
331 if (NumberOfPages
> BitsToUnitEnd
) {
333 Bits
= BitsToUnitEnd
;
335 Bits
= NumberOfPages
;
338 SetBits (Address
, Bits
, BitMap
);
340 NumberOfPages
-= Bits
;
341 Address
+= EFI_PAGES_TO_SIZE (Bits
);
346 Clear corresponding bits in bitmap table according to given memory range.
348 @param[in] Address Memory address to unset from.
349 @param[in] NumberOfPages Number of pages to unset guard.
355 ClearGuardedMemoryBits (
356 IN EFI_PHYSICAL_ADDRESS Address
,
357 IN UINTN NumberOfPages
364 while (NumberOfPages
> 0) {
365 BitsToUnitEnd
= FindGuardedMemoryMap (Address
, TRUE
, &BitMap
);
366 ASSERT (BitMap
!= NULL
);
368 if (NumberOfPages
> BitsToUnitEnd
) {
370 Bits
= BitsToUnitEnd
;
372 Bits
= NumberOfPages
;
375 ClearBits (Address
, Bits
, BitMap
);
377 NumberOfPages
-= Bits
;
378 Address
+= EFI_PAGES_TO_SIZE (Bits
);
383 Retrieve corresponding bits in bitmap table according to given memory range.
385 @param[in] Address Memory address to retrieve from.
386 @param[in] NumberOfPages Number of pages to retrieve.
388 @return An integer containing the guarded memory bitmap.
391 GetGuardedMemoryBits (
392 IN EFI_PHYSICAL_ADDRESS Address
,
393 IN UINTN NumberOfPages
402 ASSERT (NumberOfPages
<= GUARDED_HEAP_MAP_ENTRY_BITS
);
406 while (NumberOfPages
> 0) {
407 BitsToUnitEnd
= FindGuardedMemoryMap (Address
, FALSE
, &BitMap
);
409 if (NumberOfPages
> BitsToUnitEnd
) {
411 Bits
= BitsToUnitEnd
;
413 Bits
= NumberOfPages
;
416 if (BitMap
!= NULL
) {
417 Result
|= LShiftU64 (GetBits (Address
, Bits
, BitMap
), Shift
);
421 NumberOfPages
-= Bits
;
422 Address
+= EFI_PAGES_TO_SIZE (Bits
);
429 Get bit value in bitmap table for the given address.
431 @param[in] Address The address to retrieve for.
438 IN EFI_PHYSICAL_ADDRESS Address
443 FindGuardedMemoryMap (Address
, FALSE
, &GuardMap
);
444 if (GuardMap
!= NULL
) {
445 if (RShiftU64 (*GuardMap
,
446 GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address
)) & 1) {
455 Set the bit in bitmap table for the given address.
457 @param[in] Address The address to set for.
464 IN EFI_PHYSICAL_ADDRESS Address
470 FindGuardedMemoryMap (Address
, TRUE
, &GuardMap
);
471 if (GuardMap
!= NULL
) {
472 BitMask
= LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address
));
473 *GuardMap
|= BitMask
;
478 Clear the bit in bitmap table for the given address.
480 @param[in] Address The address to clear for.
487 IN EFI_PHYSICAL_ADDRESS Address
493 FindGuardedMemoryMap (Address
, TRUE
, &GuardMap
);
494 if (GuardMap
!= NULL
) {
495 BitMask
= LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address
));
496 *GuardMap
&= ~BitMask
;
501 Check to see if the page at the given address is a Guard page or not.
503 @param[in] Address The address to check for.
505 @return TRUE The page at Address is a Guard page.
506 @return FALSE The page at Address is not a Guard page.
511 IN EFI_PHYSICAL_ADDRESS Address
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
521 BitMap
= GetGuardedMemoryBits (Address
- EFI_PAGE_SIZE
, 3);
522 return ((BitMap
== BIT0
) || (BitMap
== BIT2
) || (BitMap
== (BIT2
| BIT0
)));
526 Check to see if the page at the given address is a head Guard page or not.
528 @param[in] Address The address to check for.
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.
536 IN EFI_PHYSICAL_ADDRESS Address
539 return (GetGuardedMemoryBits (Address
, 2) == BIT1
);
543 Check to see if the page at the given address is a tail Guard page or not.
545 @param[in] Address The address to check for.
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.
553 IN EFI_PHYSICAL_ADDRESS Address
556 return (GetGuardedMemoryBits (Address
- EFI_PAGE_SIZE
, 2) == BIT0
);
560 Check to see if the page at the given address is guarded or not.
562 @param[in] Address The address to check for.
564 @return TRUE The page at Address is guarded.
565 @return FALSE The page at Address is not guarded.
570 IN EFI_PHYSICAL_ADDRESS Address
573 return (GetGuardMapBit (Address
) == 1);
577 Set the page at the given address to be a Guard page.
579 This is done by changing the page table attribute to be NOT PRSENT.
581 @param[in] BaseAddress Page address to Guard at.
588 IN EFI_PHYSICAL_ADDRESS BaseAddress
591 if (mSmmMemoryAttribute
!= NULL
) {
593 mSmmMemoryAttribute
->SetMemoryAttributes (
604 Unset the Guard page at the given address to the normal memory.
606 This is done by changing the page table attribute to be PRSENT.
608 @param[in] BaseAddress Page address to Guard at.
615 IN EFI_PHYSICAL_ADDRESS BaseAddress
618 if (mSmmMemoryAttribute
!= NULL
) {
620 mSmmMemoryAttribute
->ClearMemoryAttributes (
631 Check to see if the memory at the given address should be guarded or not.
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.
638 @return TRUE The given type of memory should be guarded.
639 @return FALSE The given type of memory should not be guarded.
642 IsMemoryTypeToGuard (
643 IN EFI_MEMORY_TYPE MemoryType
,
644 IN EFI_ALLOCATE_TYPE AllocateType
,
651 if ((PcdGet8 (PcdHeapGuardPropertyMask
) & PageOrPool
) == 0
653 || AllocateType
== AllocateAddress
) {
658 if ((PageOrPool
& GUARD_HEAP_TYPE_POOL
) != 0) {
659 ConfigBit
|= PcdGet64 (PcdHeapGuardPoolType
);
662 if ((PageOrPool
& GUARD_HEAP_TYPE_PAGE
) != 0) {
663 ConfigBit
|= PcdGet64 (PcdHeapGuardPageType
);
666 if (MemoryType
== EfiRuntimeServicesData
||
667 MemoryType
== EfiRuntimeServicesCode
) {
668 TestBit
= LShiftU64 (1, MemoryType
);
669 } else if (MemoryType
== EfiMaxMemoryType
) {
670 TestBit
= (UINT64
)-1;
675 return ((ConfigBit
& TestBit
) != 0);
679 Check to see if the pool at the given address should be guarded or not.
681 @param[in] MemoryType Pool type to check.
684 @return TRUE The given type of pool should be guarded.
685 @return FALSE The given type of pool should not be guarded.
689 IN EFI_MEMORY_TYPE MemoryType
692 return IsMemoryTypeToGuard (MemoryType
, AllocateAnyPages
,
693 GUARD_HEAP_TYPE_POOL
);
697 Check to see if the page at the given address should be guarded or not.
699 @param[in] MemoryType Page type to check.
700 @param[in] AllocateType Allocation type to check.
702 @return TRUE The given type of page should be guarded.
703 @return FALSE The given type of page should not be guarded.
707 IN EFI_MEMORY_TYPE MemoryType
,
708 IN EFI_ALLOCATE_TYPE AllocateType
711 return IsMemoryTypeToGuard (MemoryType
, AllocateType
, GUARD_HEAP_TYPE_PAGE
);
715 Check to see if the heap guard is enabled for page and/or pool allocation.
724 return IsMemoryTypeToGuard (EfiMaxMemoryType
, AllocateAnyPages
,
725 GUARD_HEAP_TYPE_POOL
|GUARD_HEAP_TYPE_PAGE
);
729 Set head Guard and tail Guard for the given memory range.
731 @param[in] Memory Base address of memory to set guard for.
732 @param[in] NumberOfPages Memory size in pages.
738 IN EFI_PHYSICAL_ADDRESS Memory
,
739 IN UINTN NumberOfPages
742 EFI_PHYSICAL_ADDRESS GuardPage
;
747 GuardPage
= Memory
+ EFI_PAGES_TO_SIZE (NumberOfPages
);
748 if (!IsGuardPage (GuardPage
)) {
749 SetGuardPage (GuardPage
);
753 GuardPage
= Memory
- EFI_PAGES_TO_SIZE (1);
754 if (!IsGuardPage (GuardPage
)) {
755 SetGuardPage (GuardPage
);
759 // Mark the memory range as Guarded
761 SetGuardedMemoryBits (Memory
, NumberOfPages
);
765 Unset head Guard and tail Guard for the given memory range.
767 @param[in] Memory Base address of memory to unset guard for.
768 @param[in] NumberOfPages Memory size in pages.
773 UnsetGuardForMemory (
774 IN EFI_PHYSICAL_ADDRESS Memory
,
775 IN UINTN NumberOfPages
778 EFI_PHYSICAL_ADDRESS GuardPage
;
781 if (NumberOfPages
== 0) {
786 // Head Guard must be one page before, if any.
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 // -------------------
797 GuardPage
= Memory
- EFI_PAGES_TO_SIZE (1);
798 GuardBitmap
= GetGuardedMemoryBits (Memory
- EFI_PAGES_TO_SIZE (2), 2);
799 if ((GuardBitmap
& BIT1
) == 0) {
801 // Head Guard exists.
803 if ((GuardBitmap
& BIT0
) == 0) {
805 // If the head Guard is not a tail Guard of adjacent memory block,
808 UnsetGuardPage (GuardPage
);
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.
815 SetGuardPage (Memory
);
819 // Tail Guard must be the page after this memory block to free, if any.
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 // --------------------
830 GuardPage
= Memory
+ EFI_PAGES_TO_SIZE (NumberOfPages
);
831 GuardBitmap
= GetGuardedMemoryBits (GuardPage
, 2);
832 if ((GuardBitmap
& BIT0
) == 0) {
834 // Tail Guard exists.
836 if ((GuardBitmap
& BIT1
) == 0) {
838 // If the tail Guard is not a head Guard of adjacent memory block,
839 // free it; otherwise, keep it.
841 UnsetGuardPage (GuardPage
);
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.
848 SetGuardPage (GuardPage
- EFI_PAGES_TO_SIZE (1));
852 // No matter what, we just clear the mark of the Guarded memory.
854 ClearGuardedMemoryBits(Memory
, NumberOfPages
);
858 Adjust address of free memory according to existing and/or required Guard.
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
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.
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.
875 IN UINT64 SizeRequested
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.
885 if ((PcdGet8 (PcdHeapGuardPropertyMask
) & BIT7
) == 0) {
886 SizeRequested
= ALIGN_VALUE(SizeRequested
, 8);
889 Target
= Start
+ Size
- SizeRequested
;
891 if (!IsGuardPage (Start
+ Size
)) {
892 // No Guard at tail to share. One more page is needed.
893 Target
-= EFI_PAGES_TO_SIZE (1);
897 if (Target
< Start
) {
902 if (Target
== Start
) {
903 if (!IsGuardPage (Target
- EFI_PAGES_TO_SIZE (1))) {
904 // No enough space for a new head Guard if no Guard at head to share.
909 // OK, we have enough pages for memory and its Guards. Return the End of the
911 return Target
+ SizeRequested
- 1;
915 Adjust the start address and number of pages to free according to Guard.
917 The purpose of this function is to keep the shared Guard page with adjacent
918 memory block if it's still in guard, or free it if no more sharing. Another
919 is to reserve pages as Guard pages in partial page free situation.
921 @param[in,out] Memory Base address of memory to free.
922 @param[in,out] NumberOfPages Size of memory to free.
928 IN OUT EFI_PHYSICAL_ADDRESS
*Memory
,
929 IN OUT UINTN
*NumberOfPages
932 EFI_PHYSICAL_ADDRESS Start
;
933 EFI_PHYSICAL_ADDRESS MemoryToTest
;
937 if (Memory
== NULL
|| NumberOfPages
== NULL
|| *NumberOfPages
== 0) {
942 PagesToFree
= *NumberOfPages
;
945 // Head Guard must be one page before, if any.
948 // -------------------
949 // Head Guard -> 0 1 -> Don't free Head Guard (shared Guard)
950 // Head Guard -> 0 0 -> Free Head Guard either (not shared Guard)
951 // 1 X -> Don't free first page (need a new Guard)
952 // (it'll be turned into a Guard page later)
953 // -------------------
956 MemoryToTest
= Start
- EFI_PAGES_TO_SIZE (2);
957 GuardBitmap
= GetGuardedMemoryBits (MemoryToTest
, 2);
958 if ((GuardBitmap
& BIT1
) == 0) {
960 // Head Guard exists.
962 if ((GuardBitmap
& BIT0
) == 0) {
964 // If the head Guard is not a tail Guard of adjacent memory block,
965 // free it; otherwise, keep it.
967 Start
-= EFI_PAGES_TO_SIZE (1);
972 // No Head Guard, and pages before memory to free are still in Guard. It's a
973 // partial free case. We need to keep one page to be a tail Guard.
975 Start
+= EFI_PAGES_TO_SIZE (1);
980 // Tail Guard must be the page after this memory block to free, if any.
983 // --------------------
984 // 1 0 <- Tail Guard -> Don't free Tail Guard (shared Guard)
985 // 0 0 <- Tail Guard -> Free Tail Guard either (not shared Guard)
986 // X 1 -> Don't free last page (need a new Guard)
987 // (it'll be turned into a Guard page later)
988 // --------------------
991 MemoryToTest
= Start
+ EFI_PAGES_TO_SIZE (PagesToFree
);
992 GuardBitmap
= GetGuardedMemoryBits (MemoryToTest
, 2);
993 if ((GuardBitmap
& BIT0
) == 0) {
995 // Tail Guard exists.
997 if ((GuardBitmap
& BIT1
) == 0) {
999 // If the tail Guard is not a head Guard of adjacent memory block,
1000 // free it; otherwise, keep it.
1004 } else if (PagesToFree
> 0) {
1006 // No Tail Guard, and pages after memory to free are still in Guard. It's a
1007 // partial free case. We need to keep one page to be a head Guard.
1013 *NumberOfPages
= PagesToFree
;
1017 Adjust the base and number of pages to really allocate according to Guard.
1019 @param[in,out] Memory Base address of free memory.
1020 @param[in,out] NumberOfPages Size of memory to allocate.
1026 IN OUT EFI_PHYSICAL_ADDRESS
*Memory
,
1027 IN OUT UINTN
*NumberOfPages
1031 // FindFreePages() has already taken the Guard into account. It's safe to
1032 // adjust the start address and/or number of pages here, to make sure that
1033 // the Guards are also "allocated".
1035 if (!IsGuardPage (*Memory
+ EFI_PAGES_TO_SIZE (*NumberOfPages
))) {
1036 // No tail Guard, add one.
1037 *NumberOfPages
+= 1;
1040 if (!IsGuardPage (*Memory
- EFI_PAGE_SIZE
)) {
1041 // No head Guard, add one.
1042 *Memory
-= EFI_PAGE_SIZE
;
1043 *NumberOfPages
+= 1;
1048 Adjust the pool head position to make sure the Guard page is adjavent to
1049 pool tail or pool head.
1051 @param[in] Memory Base address of memory allocated.
1052 @param[in] NoPages Number of pages actually allocated.
1053 @param[in] Size Size of memory requested.
1054 (plus pool head/tail overhead)
1056 @return Address of pool head
1060 IN EFI_PHYSICAL_ADDRESS Memory
,
1065 if (Memory
== 0 || (PcdGet8 (PcdHeapGuardPropertyMask
) & BIT7
) != 0) {
1067 // Pool head is put near the head Guard
1069 return (VOID
*)(UINTN
)Memory
;
1073 // Pool head is put near the tail Guard
1075 Size
= ALIGN_VALUE (Size
, 8);
1076 return (VOID
*)(UINTN
)(Memory
+ EFI_PAGES_TO_SIZE (NoPages
) - Size
);
1080 Get the page base address according to pool head address.
1082 @param[in] Memory Head address of pool to free.
1084 @return Address of pool head.
1088 IN EFI_PHYSICAL_ADDRESS Memory
1091 if (Memory
== 0 || (PcdGet8 (PcdHeapGuardPropertyMask
) & BIT7
) != 0) {
1093 // Pool head is put near the head Guard
1095 return (VOID
*)(UINTN
)Memory
;
1099 // Pool head is put near the tail Guard
1101 return (VOID
*)(UINTN
)(Memory
& ~EFI_PAGE_MASK
);
1105 Helper function of memory allocation with Guard pages.
1107 @param FreePageList The free page node.
1108 @param NumberOfPages Number of pages to be allocated.
1109 @param MaxAddress Request to allocate memory below this address.
1110 @param MemoryType Type of memory requested.
1112 @return Memory address of allocated pages.
1115 InternalAllocMaxAddressWithGuard (
1116 IN OUT LIST_ENTRY
*FreePageList
,
1117 IN UINTN NumberOfPages
,
1118 IN UINTN MaxAddress
,
1119 IN EFI_MEMORY_TYPE MemoryType
1124 FREE_PAGE_LIST
*Pages
;
1130 for (Node
= FreePageList
->BackLink
; Node
!= FreePageList
;
1131 Node
= Node
->BackLink
) {
1132 Pages
= BASE_CR (Node
, FREE_PAGE_LIST
, Link
);
1133 if (Pages
->NumberOfPages
>= NumberOfPages
&&
1134 (UINTN
)Pages
+ EFI_PAGES_TO_SIZE (NumberOfPages
) - 1 <= MaxAddress
) {
1137 // We may need 1 or 2 more pages for Guard. Check it out.
1139 PagesToAlloc
= NumberOfPages
;
1140 TailGuard
= (UINTN
)Pages
+ EFI_PAGES_TO_SIZE (Pages
->NumberOfPages
);
1141 if (!IsGuardPage (TailGuard
)) {
1143 // Add one if no Guard at the end of current free memory block.
1149 HeadGuard
= (UINTN
)Pages
+
1150 EFI_PAGES_TO_SIZE (Pages
->NumberOfPages
- PagesToAlloc
) -
1152 if (!IsGuardPage (HeadGuard
)) {
1154 // Add one if no Guard at the page before the address to allocate
1160 if (Pages
->NumberOfPages
< PagesToAlloc
) {
1161 // Not enough space to allocate memory with Guards? Try next block.
1165 Address
= InternalAllocPagesOnOneNode (Pages
, PagesToAlloc
, MaxAddress
);
1166 ConvertSmmMemoryMapEntry(MemoryType
, Address
, PagesToAlloc
, FALSE
);
1167 CoreFreeMemoryMapStack();
1168 if (HeadGuard
== 0) {
1169 // Don't pass the Guard page to user.
1170 Address
+= EFI_PAGE_SIZE
;
1172 SetGuardForMemory (Address
, NumberOfPages
);
1181 Helper function of memory free with Guard pages.
1183 @param[in] Memory Base address of memory being freed.
1184 @param[in] NumberOfPages The number of pages to free.
1185 @param[in] AddRegion If this memory is new added region.
1187 @retval EFI_NOT_FOUND Could not find the entry that covers the range.
1188 @retval EFI_INVALID_PARAMETER Address not aligned, Address is zero or NumberOfPages is zero.
1189 @return EFI_SUCCESS Pages successfully freed.
1192 SmmInternalFreePagesExWithGuard (
1193 IN EFI_PHYSICAL_ADDRESS Memory
,
1194 IN UINTN NumberOfPages
,
1195 IN BOOLEAN AddRegion
1198 EFI_PHYSICAL_ADDRESS MemoryToFree
;
1201 if (((Memory
& EFI_PAGE_MASK
) != 0) || (Memory
== 0) || (NumberOfPages
== 0)) {
1202 return EFI_INVALID_PARAMETER
;
1205 MemoryToFree
= Memory
;
1206 PagesToFree
= NumberOfPages
;
1208 AdjustMemoryF (&MemoryToFree
, &PagesToFree
);
1209 UnsetGuardForMemory (Memory
, NumberOfPages
);
1210 if (PagesToFree
== 0) {
1214 return SmmInternalFreePagesEx (MemoryToFree
, PagesToFree
, AddRegion
);
1218 Set all Guard pages which cannot be set during the non-SMM mode time.
1225 UINTN Entries
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1226 UINTN Shifts
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1227 UINTN Indices
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1228 UINT64 Tables
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1229 UINT64 Addresses
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1237 if (mGuardedMemoryMap
== 0 ||
1239 mMapLevel
> GUARDED_HEAP_MAP_TABLE_DEPTH
) {
1243 CopyMem (Entries
, mLevelMask
, sizeof (Entries
));
1244 CopyMem (Shifts
, mLevelShift
, sizeof (Shifts
));
1246 SetMem (Tables
, sizeof(Tables
), 0);
1247 SetMem (Addresses
, sizeof(Addresses
), 0);
1248 SetMem (Indices
, sizeof(Indices
), 0);
1250 Level
= GUARDED_HEAP_MAP_TABLE_DEPTH
- mMapLevel
;
1251 Tables
[Level
] = mGuardedMemoryMap
;
1256 DumpGuardedMemoryBitmap ();
1260 if (Indices
[Level
] > Entries
[Level
]) {
1265 TableEntry
= ((UINT64
*)(UINTN
)(Tables
[Level
]))[Indices
[Level
]];
1266 Address
= Addresses
[Level
];
1268 if (TableEntry
== 0) {
1272 } else if (Level
< GUARDED_HEAP_MAP_TABLE_DEPTH
- 1) {
1275 Tables
[Level
] = TableEntry
;
1276 Addresses
[Level
] = Address
;
1284 while (Index
< GUARDED_HEAP_MAP_ENTRY_BITS
) {
1285 if ((TableEntry
& 1) == 1) {
1289 GuardPage
= Address
- EFI_PAGE_SIZE
;
1294 GuardPage
= Address
;
1301 if (GuardPage
!= 0) {
1302 SetGuardPage (GuardPage
);
1305 if (TableEntry
== 0) {
1309 TableEntry
= RShiftU64 (TableEntry
, 1);
1310 Address
+= EFI_PAGE_SIZE
;
1316 if (Level
< (GUARDED_HEAP_MAP_TABLE_DEPTH
- (INTN
)mMapLevel
)) {
1320 Indices
[Level
] += 1;
1321 Address
= (Level
== 0) ? 0 : Addresses
[Level
- 1];
1322 Addresses
[Level
] = Address
| LShiftU64(Indices
[Level
], Shifts
[Level
]);
1328 Hook function used to set all Guard pages after entering SMM mode.
1331 SmmEntryPointMemoryManagementHook (
1337 if (mSmmMemoryAttribute
== NULL
) {
1338 Status
= SmmLocateProtocol (
1339 &gEdkiiSmmMemoryAttributeProtocolGuid
,
1341 (VOID
**)&mSmmMemoryAttribute
1343 if (!EFI_ERROR(Status
)) {
1344 SetAllGuardPages ();
1350 Helper function to convert a UINT64 value in binary to a string.
1352 @param[in] Value Value of a UINT64 integer.
1353 @param[out] BinString String buffer to contain the conversion result.
1360 OUT CHAR8
*BinString
1365 if (BinString
== NULL
) {
1369 for (Index
= 64; Index
> 0; --Index
) {
1370 BinString
[Index
- 1] = '0' + (Value
& 1);
1371 Value
= RShiftU64 (Value
, 1);
1373 BinString
[64] = '\0';
1377 Dump the guarded memory bit map.
1381 DumpGuardedMemoryBitmap (
1385 UINTN Entries
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1386 UINTN Shifts
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1387 UINTN Indices
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1388 UINT64 Tables
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1389 UINT64 Addresses
[GUARDED_HEAP_MAP_TABLE_DEPTH
];
1394 CHAR8 String
[GUARDED_HEAP_MAP_ENTRY_BITS
+ 1];
1398 if (mGuardedMemoryMap
== 0 ||
1400 mMapLevel
> GUARDED_HEAP_MAP_TABLE_DEPTH
) {
1404 Ruler1
= " 3 2 1 0";
1405 Ruler2
= "FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210";
1407 DEBUG ((HEAP_GUARD_DEBUG_LEVEL
, "============================="
1408 " Guarded Memory Bitmap "
1409 "==============================\r\n"));
1410 DEBUG ((HEAP_GUARD_DEBUG_LEVEL
, " %a\r\n", Ruler1
));
1411 DEBUG ((HEAP_GUARD_DEBUG_LEVEL
, " %a\r\n", Ruler2
));
1413 CopyMem (Entries
, mLevelMask
, sizeof (Entries
));
1414 CopyMem (Shifts
, mLevelShift
, sizeof (Shifts
));
1416 SetMem (Indices
, sizeof(Indices
), 0);
1417 SetMem (Tables
, sizeof(Tables
), 0);
1418 SetMem (Addresses
, sizeof(Addresses
), 0);
1420 Level
= GUARDED_HEAP_MAP_TABLE_DEPTH
- mMapLevel
;
1421 Tables
[Level
] = mGuardedMemoryMap
;
1426 if (Indices
[Level
] > Entries
[Level
]) {
1433 HEAP_GUARD_DEBUG_LEVEL
,
1434 "========================================="
1435 "=========================================\r\n"
1440 TableEntry
= ((UINT64
*)(UINTN
)Tables
[Level
])[Indices
[Level
]];
1441 Address
= Addresses
[Level
];
1443 if (TableEntry
== 0) {
1445 if (Level
== GUARDED_HEAP_MAP_TABLE_DEPTH
- 1) {
1446 if (RepeatZero
== 0) {
1447 Uint64ToBinString(TableEntry
, String
);
1448 DEBUG ((HEAP_GUARD_DEBUG_LEVEL
, "%016lx: %a\r\n", Address
, String
));
1449 } else if (RepeatZero
== 1) {
1450 DEBUG ((HEAP_GUARD_DEBUG_LEVEL
, "... : ...\r\n"));
1455 } else if (Level
< GUARDED_HEAP_MAP_TABLE_DEPTH
- 1) {
1458 Tables
[Level
] = TableEntry
;
1459 Addresses
[Level
] = Address
;
1468 Uint64ToBinString(TableEntry
, String
);
1469 DEBUG ((HEAP_GUARD_DEBUG_LEVEL
, "%016lx: %a\r\n", Address
, String
));
1474 if (Level
< (GUARDED_HEAP_MAP_TABLE_DEPTH
- (INTN
)mMapLevel
)) {
1478 Indices
[Level
] += 1;
1479 Address
= (Level
== 0) ? 0 : Addresses
[Level
- 1];
1480 Addresses
[Level
] = Address
| LShiftU64(Indices
[Level
], Shifts
[Level
]);
1486 Debug function used to verify if the Guard page is well set or not.
1488 @param[in] BaseAddress Address of memory to check.
1489 @param[in] NumberOfPages Size of memory in pages.
1491 @return TRUE The head Guard and tail Guard are both well set.
1492 @return FALSE The head Guard and/or tail Guard are not well set.
1496 IN EFI_PHYSICAL_ADDRESS BaseAddress
,
1497 IN UINTN NumberOfPages
1502 EFI_PHYSICAL_ADDRESS Address
;
1504 if (mSmmMemoryAttribute
== NULL
) {
1509 Address
= BaseAddress
- EFI_PAGE_SIZE
;
1510 Status
= mSmmMemoryAttribute
->GetMemoryAttributes (
1511 mSmmMemoryAttribute
,
1516 if (EFI_ERROR (Status
) || (Attribute
& EFI_MEMORY_RP
) == 0) {
1517 DEBUG ((DEBUG_ERROR
, "Head Guard is not set at: %016lx (%016lX)!!!\r\n",
1518 Address
, Attribute
));
1519 DumpGuardedMemoryBitmap ();
1524 Address
= BaseAddress
+ EFI_PAGES_TO_SIZE (NumberOfPages
);
1525 Status
= mSmmMemoryAttribute
->GetMemoryAttributes (
1526 mSmmMemoryAttribute
,
1531 if (EFI_ERROR (Status
) || (Attribute
& EFI_MEMORY_RP
) == 0) {
1532 DEBUG ((DEBUG_ERROR
, "Tail Guard is not set at: %016lx (%016lX)!!!\r\n",
1533 Address
, Attribute
));
1534 DumpGuardedMemoryBitmap ();