From e38451cd9a87f86d9c699281252d381e10dcc98e Mon Sep 17 00:00:00 2001 From: Jian J Wang Date: Thu, 23 Nov 2017 09:48:33 +0800 Subject: [PATCH 1/1] MdeModulePkg/DxeCore: Filter out all paging capabilities Some OSs will treat EFI_MEMORY_DESCRIPTOR.Attribute as really set attributes and change memory paging attribute accordingly. But current EFI_MEMORY_DESCRIPTOR.Attribute is assigned by value from Capabilities in GCD memory map. This might cause boot problems. Clearing all paging related capabilities can workaround it. The code added in this patch is supposed to be removed once the usage of EFI_MEMORY_DESCRIPTOR.Attribute is clarified in UEFI spec and adopted by both EDK-II Core and all supported OSs. Laszlo did a thorough test on OVMF emulated platform. The details can be found at https://bugzilla.tianocore.org/show_bug.cgi?id=753#c10 Cc: Jiewen Yao Cc: Star Zeng Cc: Laszlo Ersek Cc: Ard Biesheuvel Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang Tested-by: Laszlo Ersek Reviewed-by: Star Zeng Reviewed-by: Laszlo Ersek --- MdeModulePkg/Core/Dxe/Mem/Page.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/MdeModulePkg/Core/Dxe/Mem/Page.c b/MdeModulePkg/Core/Dxe/Mem/Page.c index 2034b64cd7..962ae90d3d 100644 --- a/MdeModulePkg/Core/Dxe/Mem/Page.c +++ b/MdeModulePkg/Core/Dxe/Mem/Page.c @@ -1687,6 +1687,7 @@ CoreGetMemoryMap ( EFI_GCD_MAP_ENTRY MergeGcdMapEntry; EFI_MEMORY_TYPE Type; EFI_MEMORY_DESCRIPTOR *MemoryMapStart; + EFI_MEMORY_DESCRIPTOR *MemoryMapEnd; // // Make sure the parameters are valid @@ -1896,6 +1897,25 @@ CoreGetMemoryMap ( // BufferSize = ((UINT8 *)MemoryMap - (UINT8 *)MemoryMapStart); + // + // Note: Some OSs will treat EFI_MEMORY_DESCRIPTOR.Attribute as really + // set attributes and change memory paging attribute accordingly. + // But current EFI_MEMORY_DESCRIPTOR.Attribute is assigned by + // value from Capabilities in GCD memory map. This might cause + // boot problems. Clearing all paging related capabilities can + // workaround it. Following code is supposed to be removed once + // the usage of EFI_MEMORY_DESCRIPTOR.Attribute is clarified in + // UEFI spec and adopted by both EDK-II Core and all supported + // OSs. + // + MemoryMapEnd = MemoryMap; + MemoryMap = MemoryMapStart; + while (MemoryMap < MemoryMapEnd) { + MemoryMap->Attribute &= ~(UINT64)(EFI_MEMORY_RP | EFI_MEMORY_RO | + EFI_MEMORY_XP); + MemoryMap = NEXT_MEMORY_DESCRIPTOR (MemoryMap, Size); + } + Status = EFI_SUCCESS; Done: -- 2.39.2