To reproduce the issue:
UINTN PageTable;
VOID *Buffer;
UINTN PageTableBufferSize;
IA32_MAP_ATTRIBUTE Attribute;
IA32_MAP_ATTRIBUTE Mask;
RETURN_STATUS Status;
Attribute.Uint64 = 0;
Mask.Uint64 = 0;
PageTableBufferSize = 0;
PageTable = 0;
Buffer = NULL;
Attribute.Bits.Present = 1;
Attribute.Bits.Nx = 1;
Mask.Bits.Present = 1;
Mask.Uint64 = MAX_UINT64;
//
// Create page table to cover [0, 10M)
//
Status = PageTableMap (
&PageTable, PagingMode, Buffer, &PageTableBufferSize,
0, (UINT64)SIZE_2MB * 5, &Attribute, &Mask
);
ASSERT (Status == RETURN_BUFFER_TOO_SMALL);
Buffer = AllocatePages (EFI_SIZE_TO_PAGES (PageTableBufferSize));
Status = PageTableMap (
&PageTable, PagingMode, Buffer, &PageTableBufferSize,
0, (UINT64)SIZE_2MB * 5, &Attribute, &Mask
);
ASSERT (Status == RETURN_SUCCESS);
//
// Change the mapping for [0, 4KB)
// No change actually. Just clear Nx bit in Mask.
//
Mask.Bits.Nx = 0;
PageTableBufferSize = 0;
Status = PageTableMap (
&PageTable, PagingMode, NULL, &PageTableBufferSize,
0, (UINT64)SIZE_4KB, &Attribute, &Mask
);
ASSERT (Status == RETURN_SUCCESS); // FAIL!!
The root cause is when comparing the existing mapping attributes
against the requested one, Mask is not used but it should be used.
Signed-off-by: Zhiguang Liu <zhiguang....@intel.com>
Reviewed-by: Ray Ni <ray...@intel.com>
Cc: Eric Dong <eric.d...@intel.com>
---
UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
index 17bca5e351..429b014b7b 100644
--- a/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
+++ b/UefiCpuPkg/Library/CpuPageTableLib/CpuPageTableMap.c
@@ -308,7 +308,7 @@ PageTableLibMapInLevel (
//
PleBAttribute.Uint64 = PageTableLibGetPleBMapAttribute
(&ParentPagingEntry->PleB, &NopAttribute);
if ((IA32_MAP_ATTRIBUTE_ATTRIBUTES (&PleBAttribute) &
IA32_MAP_ATTRIBUTE_ATTRIBUTES (Mask))
- == IA32_MAP_ATTRIBUTE_ATTRIBUTES (Attribute))
+ == (IA32_MAP_ATTRIBUTE_ATTRIBUTES (Attribute) &
IA32_MAP_ATTRIBUTE_ATTRIBUTES (Mask)))
{
//
// This function is called when the memory length is less than the
region length of the parent level.
--
2.35.1.windows.2
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