diff options
| -rw-r--r-- | MdeModulePkg/Core/Dxe/Mem/HeapGuard.c | 15 | ||||
| -rw-r--r-- | MdeModulePkg/Core/Dxe/Mem/Page.c | 40 | ||||
| -rw-r--r-- | MdeModulePkg/Core/Dxe/Mem/Pool.c | 10 |
3 files changed, 29 insertions, 36 deletions
diff --git a/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c b/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c index 0f03504..92753c7 100644 --- a/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c +++ b/MdeModulePkg/Core/Dxe/Mem/HeapGuard.c @@ -1127,11 +1127,26 @@ CoreConvertPagesWithGuard ( IN EFI_MEMORY_TYPE NewType
)
{
+ UINT64 OldStart;
+ UINTN OldPages;
+
if (NewType == EfiConventionalMemory) {
+ OldStart = Start;
+ OldPages = NumberOfPages;
+
AdjustMemoryF (&Start, &NumberOfPages);
if (NumberOfPages == 0) {
return EFI_SUCCESS;
}
+
+ //
+ // It's safe to unset Guard page inside memory lock because there should
+ // be no memory allocation occurred in updating memory page attribute at
+ // this point. And unsetting Guard page before free will prevent Guard
+ // page just freed back to pool from being allocated right away before
+ // marking it usable (from non-present to present).
+ //
+ UnsetGuardForMemory (OldStart, OldPages);
} else {
AdjustMemoryA (&Start, &NumberOfPages);
}
diff --git a/MdeModulePkg/Core/Dxe/Mem/Page.c b/MdeModulePkg/Core/Dxe/Mem/Page.c index db32d0f..8d5d03a 100644 --- a/MdeModulePkg/Core/Dxe/Mem/Page.c +++ b/MdeModulePkg/Core/Dxe/Mem/Page.c @@ -900,42 +900,17 @@ CoreConvertPagesEx ( //
CoreAddRange (MemType, Start, RangeEnd, Attribute);
if (ChangingType && (MemType == EfiConventionalMemory)) {
+ //
+ // Avoid calling DEBUG_CLEAR_MEMORY() for an address of 0 because this
+ // macro will ASSERT() if address is 0. Instead, CoreAddRange() guarantees
+ // that the page starting at address 0 is always filled with zeros.
+ //
if (Start == 0) {
- //
- // Avoid calling DEBUG_CLEAR_MEMORY() for an address of 0 because this
- // macro will ASSERT() if address is 0. Instead, CoreAddRange()
- // guarantees that the page starting at address 0 is always filled
- // with zeros.
- //
if (RangeEnd > EFI_PAGE_SIZE) {
DEBUG_CLEAR_MEMORY ((VOID *)(UINTN) EFI_PAGE_SIZE, (UINTN) (RangeEnd - EFI_PAGE_SIZE + 1));
}
} else {
- //
- // If Heap Guard is enabled, the page at the top and/or bottom of
- // this memory block to free might be inaccessible. Skipping them
- // to avoid page fault exception.
- //
- UINT64 StartToClear;
- UINT64 EndToClear;
-
- StartToClear = Start;
- EndToClear = RangeEnd + 1;
- if (PcdGet8 (PcdHeapGuardPropertyMask) & (BIT1|BIT0)) {
- if (IsGuardPage(StartToClear)) {
- StartToClear += EFI_PAGE_SIZE;
- }
- if (IsGuardPage (EndToClear - 1)) {
- EndToClear -= EFI_PAGE_SIZE;
- }
- }
-
- if (EndToClear > StartToClear) {
- DEBUG_CLEAR_MEMORY(
- (VOID *)(UINTN)StartToClear,
- (UINTN)(EndToClear - StartToClear)
- );
- }
+ DEBUG_CLEAR_MEMORY ((VOID *)(UINTN) Start, (UINTN) (RangeEnd - Start + 1));
}
}
@@ -1513,9 +1488,6 @@ CoreInternalFreePages ( Done:
CoreReleaseMemoryLock ();
- if (IsGuarded) {
- UnsetGuardForMemory(Memory, NumberOfPages);
- }
return Status;
}
diff --git a/MdeModulePkg/Core/Dxe/Mem/Pool.c b/MdeModulePkg/Core/Dxe/Mem/Pool.c index 7464d87..df9a1d2 100644 --- a/MdeModulePkg/Core/Dxe/Mem/Pool.c +++ b/MdeModulePkg/Core/Dxe/Mem/Pool.c @@ -643,10 +643,16 @@ CoreFreePoolPagesWithGuard ( AdjustMemoryF (&Memory, &NoPages);
if (NoPages > 0) {
+ //
+ // It's safe to unset Guard page inside memory lock because there should
+ // be no memory allocation occurred in updating memory page attribute at
+ // this point. And unsetting Guard page before free will prevent Guard
+ // page just freed back to pool from being allocated right away before
+ // marking it usable (from non-present to present).
+ //
+ UnsetGuardForMemory (MemoryGuarded, NoPagesGuarded);
CoreFreePoolPagesI (PoolType, Memory, NoPages);
}
-
- UnsetGuardForMemory (MemoryGuarded, NoPagesGuarded);
}
/**
|