diff options
Diffstat (limited to 'UefiCpuPkg/Library')
| -rw-r--r-- | UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c index 7c2bd25d22..6a39ac3830 100644 --- a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c +++ b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c @@ -294,7 +294,7 @@ IsAttributesAndMaskValidForNonPresentEntry ( Page table entries that map the linear address range are reset to 0 before set to the new attribute
when a new physical base address is set.
@param[in] Mask The mask used for attribute. The corresponding field in Attribute is ignored if that in Mask is 0.
- @param[out] IsModified TRUE means page table is modified. FALSE means page table is not modified.
+ @param[in, out] IsModified Change IsModified to True if page table is modified and input parameter Modify is TRUE.
@retval RETURN_INVALID_PARAMETER For non-present range, Mask->Bits.Present is 0 but some other attributes are provided.
@retval RETURN_INVALID_PARAMETER For non-present range, Mask->Bits.Present is 1, Attribute->Bits.Present is 1 but some other attributes are not provided.
@@ -314,7 +314,7 @@ PageTableLibMapInLevel ( IN UINT64 Offset,
IN IA32_MAP_ATTRIBUTE *Attribute,
IN IA32_MAP_ATTRIBUTE *Mask,
- OUT BOOLEAN *IsModified
+ IN OUT BOOLEAN *IsModified
)
{
RETURN_STATUS Status;
@@ -587,7 +587,10 @@ PageTableLibMapInLevel ( OriginalCurrentPagingEntry.Uint64 = CurrentPagingEntry->Uint64;
PageTableLibSetPle (Level, CurrentPagingEntry, Offset, Attribute, &CurrentMask);
- if (OriginalCurrentPagingEntry.Uint64 != CurrentPagingEntry->Uint64) {
+ if (Modify && (OriginalCurrentPagingEntry.Uint64 != CurrentPagingEntry->Uint64)) {
+ //
+ // The page table entry can be changed by this function only when Modify is true.
+ //
*IsModified = TRUE;
}
}
@@ -629,7 +632,10 @@ PageTableLibMapInLevel ( // Check if ParentPagingEntry entry is modified here is enough. Except the changes happen in leaf PagingEntry during
// the while loop, if there is any other change happens in page table, the ParentPagingEntry must has been modified.
//
- if (OriginalParentPagingEntry.Uint64 != ParentPagingEntry->Uint64) {
+ if (Modify && (OriginalParentPagingEntry.Uint64 != ParentPagingEntry->Uint64)) {
+ //
+ // The page table entry can be changed by this function only when Modify is true.
+ //
*IsModified = TRUE;
}
@@ -654,7 +660,9 @@ PageTableLibMapInLevel ( Page table entries that map the linear address range are reset to 0 before set to the new attribute
when a new physical base address is set.
@param[in] Mask The mask used for attribute. The corresponding field in Attribute is ignored if that in Mask is 0.
- @param[out] IsModified TRUE means page table is modified. FALSE means page table is not modified.
+ @param[out] IsModified TRUE means page table is modified by software or hardware. FALSE means page table is not modified by software.
+ If the output IsModified is FALSE, there is possibility that the page table is changed by hardware. It is ok
+ because page table can be changed by hardware anytime, and caller don't need to Flush TLB.
@retval RETURN_UNSUPPORTED PagingMode is not supported.
@retval RETURN_INVALID_PARAMETER PageTable, BufferSize, Attribute or Mask is NULL.
|