Reviewed-by: Eric Dong <[email protected]> > -----Original Message----- > From: Ni, Ray > Sent: Saturday, July 27, 2019 11:29 AM > To: [email protected] > Cc: Dong, Eric <[email protected]>; Yao, Jiewen <[email protected]>; > Wang, Jian J <[email protected]> > Subject: [PATCH 3/3] UefiCpuPkg/PiSmmCpu: Allow SMM access-out when > static paging is OFF > > Commit c60d36b4d1ee1f69b7cca897d3621dfa951895c2 > * UefiCpuPkg/SmmCpu: Block access-out only when static paging is used > > updated page fault handler to treat SMM access-out as allowed address > when static paging is not used. > > But that commit is not complete because the page table is still updated in > SetUefiMemMapAttributes() for non-SMRAM memory. When SMM code > accesses non-SMRAM memory, page fault is still generated. > > This patch skips to update page table for non-SMRAM memory and page > table itself. > > Signed-off-by: Ray Ni <[email protected]> > Cc: Eric Dong <[email protected]> > Cc: Jiewen Yao <[email protected]> > Cc: Jian J Wang <[email protected]> > --- > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 21 > +++++++++++++++------ > 1 file changed, 15 insertions(+), 6 deletions(-) > > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > index 69a04dfb23..d7d94c8b6d 100644 > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > @@ -1121,6 +1121,9 @@ FindSmramInfo ( > *SmrrBase = (UINT32)CurrentSmramRange->CpuStart; > *SmrrSize = (UINT32)CurrentSmramRange->PhysicalSize; > > + // > + // Extend *SmrrBase/*SmrrSize to include adjacent SMRAM ranges // > do { > Found = FALSE; > for (Index = 0; Index < mSmmCpuSmramRangeCount; Index++) { @@ - > 1432,14 +1435,20 @@ PerformRemainingTasks ( > SetMemMapAttributes (); > > // > - // For outside SMRAM, we only map SMM communication buffer or > MMIO. > + // Protect memory outside SMRAM when SMM Static Page Table is > enabled. > // > - SetUefiMemMapAttributes (); > + if (IsStaticPageTableEnabled ()) { > > - // > - // Set page table itself to be read-only > - // > - SetPageTableAttributes (); > + // > + // For outside SMRAM, we only map SMM communication buffer or > MMIO. > + // > + SetUefiMemMapAttributes (); > + > + // > + // Set page table itself to be read-only > + // > + SetPageTableAttributes (); > + } > > // > // Configure SMM Code Access Check feature if available. > -- > 2.21.0.windows.1
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