From: Jiewen Yao <[email protected]> Today's implementation blocks SMM read-out no matter static paging is enabled or not. But certain platform may need to read non-SMM content from SMM code. These platforms don't have a way to disable the read-out blocking.
The patch updates the policy to only block SMM read-out when static paging is enabled. So that the static paging can be disabled for those platforms that want SMM read-out. Setting PcdCpuSmmStaticPageTable to FALSE can disable the static paging. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jiewen Yao <[email protected]> Signed-off-by: Ruiyu Ni <[email protected]> Cc: Eric Dong <[email protected]> Cc: Jiewen Yao <[email protected]> Cc: Laszlo Ersek <[email protected]> --- UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c index 5bb7d57238..117502dafa 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c @@ -1,7 +1,7 @@ /** @file Page Fault (#PF) handler for X64 processors -Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR> +Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR> Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR> This program and the accompanying materials @@ -890,7 +890,7 @@ SmiPFHandler ( CpuDeadLoop (); } - if (IsSmmCommBufferForbiddenAddress (PFAddress)) { + if (mCpuSmmStaticPageTable && IsSmmCommBufferForbiddenAddress (PFAddress)) { DumpCpuContext (InterruptType, SystemContext); DEBUG ((DEBUG_ERROR, "Access SMM communication forbidden address (0x%lx)!\n", PFAddress)); DEBUG_CODE ( -- 2.16.1.windows.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
