The Memory Attributes Table is generated by fetching the EFI memory map and splitting entries which contain loaded images so DATA and CODE sections have separate descriptors. The splitting is done via a call to SplitTable() which marks image DATA sections with the EFI_MEMORY_XP attribute and CODE sections with the EFI_MEMORY_RO attribute when splitting. After this process, there may still be EfiRuntimeServicesCode regions which did not have their attributes set because they are not part of loaded images.
This patch updates the MAT EnforceMemoryMapAttribute logic to set the access attributes of runtime memory regions which are not part of loaded images (have not had their access attributes set). Cc: Liming Gao <gaolim...@byosoft.com.cn> Signed-off-by: Taylor Beebe <taylor.d.be...@gmail.com> --- MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c | 29 ++++++++++---------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c b/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c index e9343a2c4e..1d9f935db0 100644 --- a/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c +++ b/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c @@ -425,8 +425,8 @@ MergeMemoryMap ( } /** - Enforce memory map attributes. - This function will set EfiRuntimeServicesData/EfiMemoryMappedIO/EfiMemoryMappedIOPortSpace to be EFI_MEMORY_XP. + Walk the memory map and set EfiRuntimeServicesData/EfiMemoryMappedIO/EfiMemoryMappedIOPortSpace + to EFI_MEMORY_XP and EfiRuntimeServicesCode to EFI_MEMORY_RO. @param MemoryMap A pointer to the buffer in which firmware places the current memory map. @@ -447,18 +447,19 @@ EnforceMemoryMapAttribute ( MemoryMapEntry = MemoryMap; MemoryMapEnd = (EFI_MEMORY_DESCRIPTOR *)((UINT8 *)MemoryMap + MemoryMapSize); while ((UINTN)MemoryMapEntry < (UINTN)MemoryMapEnd) { - switch (MemoryMapEntry->Type) { - case EfiRuntimeServicesCode: - // do nothing - break; - case EfiRuntimeServicesData: - case EfiMemoryMappedIO: - case EfiMemoryMappedIOPortSpace: - MemoryMapEntry->Attribute |= EFI_MEMORY_XP; - break; - case EfiReservedMemoryType: - case EfiACPIMemoryNVS: - break; + if ((MemoryMapEntry->Attribute & EFI_MEMORY_ACCESS_MASK) == 0) { + switch (MemoryMapEntry->Type) { + case EfiRuntimeServicesCode: + MemoryMapEntry->Attribute |= EFI_MEMORY_RO; + break; + case EfiRuntimeServicesData: + case EfiMemoryMappedIO: + case EfiMemoryMappedIOPortSpace: + MemoryMapEntry->Attribute |= EFI_MEMORY_XP; + break; + default: + break; + } } MemoryMapEntry = NEXT_MEMORY_DESCRIPTOR (MemoryMapEntry, DescriptorSize); -- 2.40.1.vfs.0.0 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#117889): https://edk2.groups.io/g/devel/message/117889 Mute This Topic: https://groups.io/mt/105570114/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-