tyler.durden
/
audk
mirror of https://github.com/acidanthera/audk.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

UefiCpuPkg/CpuDxe: clear NX attr for page directory 

If PcdDxeNxMemoryProtectionPolicy is set to enable protection for memory
of EfiBootServicesCode, EfiConventionalMemory and EfiReservedMemoryType,
the BIOS will hang at a page fault exception randomly.

The root cause is that the memory allocation for driver images (actually
a memory type conversion from free memory, type of EfiConventionalMemory,
to code memory, type of EfiBootServicesCode/EfiRuntimeServicesCode)
will get memory with NX set, because the CpuDxe driver will keep the NX
attribute (with free memory) in page directory during page table splitting
and then override the NX attribute of all its entries.

This patch fixes this issue by not inheriting NX attribute when turning
a page entry into a page directory during page granularity split.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
This commit is contained in:
Jian J Wang 2018-01-15 10:00:39 +08:00 committed by Ruiyu Ni
parent fceafda518
commit fbe2c4b9be
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
UefiCpuPkg/CpuDxe/CpuPageTable.c
View File

@ -528,7 +528,7 @@ SplitPage (
for (Index = 0; Index < SIZE_4KB / sizeof(UINT64); Index++) {
NewPageEntry[Index] = (BaseAddress + SIZE_4KB * Index) | AddressEncMask | ((*PageEntry) & PAGE_PROGATE_BITS);
}
(*PageEntry) = (UINT64)(UINTN)NewPageEntry | AddressEncMask | ((*PageEntry) & PAGE_PROGATE_BITS);
(*PageEntry) = (UINT64)(UINTN)NewPageEntry | AddressEncMask | ((*PageEntry) & PAGE_ATTRIBUTE_BITS);
return RETURN_SUCCESS;
} else {
return RETURN_UNSUPPORTED;
@ -549,7 +549,7 @@ SplitPage (
for (Index = 0; Index < SIZE_4KB / sizeof(UINT64); Index++) {
NewPageEntry[Index] = (BaseAddress + SIZE_2MB * Index) | AddressEncMask | IA32_PG_PS | ((*PageEntry) & PAGE_PROGATE_BITS);
}
(*PageEntry) = (UINT64)(UINTN)NewPageEntry | AddressEncMask | ((*PageEntry) & PAGE_PROGATE_BITS);
(*PageEntry) = (UINT64)(UINTN)NewPageEntry | AddressEncMask | ((*PageEntry) & PAGE_ATTRIBUTE_BITS);
return RETURN_SUCCESS;
} else {
return RETURN_UNSUPPORTED;
@ -983,7 +983,7 @@ RefreshGcdMemoryAttributesFromPaging (
);
ASSERT_EFI_ERROR (Status);
DEBUG ((
DEBUG_INFO,
DEBUG_VERBOSE,
"Updated memory space attribute: [%lu] %016lx - %016lx (%016lx -> %016lx)\r\n",
(UINT64)Index, BaseAddress, BaseAddress + Length - 1,
MemorySpaceMap[Index].Attributes,