Re: [edk2] [PATCH 5/5] UefiCpuPkg/PiSmmCpuDxeSmm: Disable page table protection

[Wang, Jian J]

You're right. "BIT3 | BIT2" should be enclosed by parentheses. Thanks for 
catching this issue.

> -Original Message-
> From: Dong, Eric
> Sent: Friday, October 13, 2017 9:24 AM
> To: Wang, Jian J ; edk2-devel@lists.01.org
> Cc: Yao, Jiewen ; Kinney, Michael D
> ; Wolman, Ayellet 
> Subject: RE: [PATCH 5/5] UefiCpuPkg/PiSmmCpuDxeSmm: Disable page table
> protection
> 
> Hi Jian,
> 
> > +  if (!mCpuSmmStaticPageTable || (PcdGet8 (PcdHeapGuardPropertyMask)
> > &
> > + BIT3 | BIT2) != 0) {
> 
> I think above code logic is not correct, the "&" will be handled before the 
> "|"
> which is not an expected order, right?
> 
> Thanks,
> Eric
> 
> > -Original Message-
> > From: Wang, Jian J
> > Sent: Wednesday, October 11, 2017 11:18 AM
> > To: edk2-devel@lists.01.org
> > Cc: Dong, Eric ; Yao, Jiewen ;
> > Kinney, Michael D ; Wolman, Ayellet
> > 
> > Subject: [PATCH 5/5] UefiCpuPkg/PiSmmCpuDxeSmm: Disable page table
> > protection
> >
> > Heap guard feature will update page attributes frequently. The page table
> > should not set to be read-only if heap guard feature is enabled for SMM
> > mode. Otherwise this feature cannot work.
> >
> > Cc: Eric Dong 
> > Cc: Jiewen Yao 
> > Cc: Michael Kinney 
> > Cc: Ayellet Wolman 
> > Suggested-by: Ayellet Wolman 
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Jian J Wang 
> > ---
> >  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf | 1 +
> >  UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c  | 2 +-
> >  2 files changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> > index 099792e6ce..644709650c 100644
> > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> > @@ -159,6 +159,7 @@
> >gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmStaticPageTable   ##
> > CONSUMES
> >gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiS3Enable   ##
> > CONSUMES
> >
> > gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrM
> > ask## CONSUMES
> > +  gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask
> > ## CONSUMES
> >
> >  [Depex]
> >gEfiMpServiceProtocolGuid
> > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> > b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> > index 3dde80f9ba..4debce3a0f 100644
> > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> > @@ -902,7 +902,7 @@ SetPageTableAttributes (
> >BOOLEAN   IsSplitted;
> >BOOLEAN   PageTableSplitted;
> >
> > -  if (!mCpuSmmStaticPageTable) {
> > +  if (!mCpuSmmStaticPageTable || (PcdGet8 (PcdHeapGuardPropertyMask)
> > &
> > + BIT3 | BIT2) != 0) {
> >  return ;
> >}
> >
> > --
> > 2.14.1.windows.1

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Re: [edk2] [PATCH 5/5] UefiCpuPkg/PiSmmCpuDxeSmm: Disable page table protection

[Dong, Eric]

Hi Jian,

> +  if (!mCpuSmmStaticPageTable || (PcdGet8 (PcdHeapGuardPropertyMask)
> &
> + BIT3 | BIT2) != 0) {

I think above code logic is not correct, the "&" will be handled before the "|" 
which is not an expected order, right?

Thanks,
Eric

> -Original Message-
> From: Wang, Jian J
> Sent: Wednesday, October 11, 2017 11:18 AM
> To: edk2-devel@lists.01.org
> Cc: Dong, Eric ; Yao, Jiewen ;
> Kinney, Michael D ; Wolman, Ayellet
> 
> Subject: [PATCH 5/5] UefiCpuPkg/PiSmmCpuDxeSmm: Disable page table
> protection
> 
> Heap guard feature will update page attributes frequently. The page table
> should not set to be read-only if heap guard feature is enabled for SMM
> mode. Otherwise this feature cannot work.
> 
> Cc: Eric Dong 
> Cc: Jiewen Yao 
> Cc: Michael Kinney 
> Cc: Ayellet Wolman 
> Suggested-by: Ayellet Wolman 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Jian J Wang 
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf | 1 +
>  UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c  | 2 +-
>  2 files changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> index 099792e6ce..644709650c 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf
> @@ -159,6 +159,7 @@
>gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmStaticPageTable   ##
> CONSUMES
>gEfiMdeModulePkgTokenSpaceGuid.PcdAcpiS3Enable   ##
> CONSUMES
> 
> gEfiMdeModulePkgTokenSpaceGuid.PcdPteMemoryEncryptionAddressOrM
> ask## CONSUMES
> +  gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask
> ## CONSUMES
> 
>  [Depex]
>gEfiMpServiceProtocolGuid
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> index 3dde80f9ba..4debce3a0f 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/X64/PageTbl.c
> @@ -902,7 +902,7 @@ SetPageTableAttributes (
>BOOLEAN   IsSplitted;
>BOOLEAN   PageTableSplitted;
> 
> -  if (!mCpuSmmStaticPageTable) {
> +  if (!mCpuSmmStaticPageTable || (PcdGet8 (PcdHeapGuardPropertyMask)
> &
> + BIT3 | BIT2) != 0) {
>  return ;
>}
> 
> --
> 2.14.1.windows.1

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