Re: [PATCH V2 2/3] ArmPkg/CpuDxe: Correct EFI_MEMORY_RO usage

["Yao, Jiewen" <jiewen.yao@intel.com>]

Hi Leif
Here is 2nd patch. I did a global replace for EFI_MEMORY_WP.

I have to send this patch because I updated DxeCore to use EFI_MEMORY_RO and EFI_MEMORY_XP for PE image protection.


Assuming the original EFI_MEMORY_WP can work, I think this EFI_MEMORY_RO update is no harm.
But if the original EFI_MEMORY_WP is not validated, this core update has risk.

(Such as X86 CPU, we need apply a patch to support EFI_MEMORY_RO.)

Is that possible that you help me do a quick validation to check if the DxeCore update breaks anything on ARM?


Thank you
Yao Jiewen



> -----Original Message-----
> From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Jiewen
> Yao
> Sent: Thursday, January 26, 2017 8:32 PM
> To: edk2-devel@lists.01.org
> Cc: Leif Lindholm <leif.lindholm@linaro.org>; Ard Biesheuvel
> <ard.biesheuvel@linaro.org>
> Subject: [edk2] [PATCH V2 2/3] ArmPkg/CpuDxe: Correct EFI_MEMORY_RO
> usage
>
> Current Arm CpuDxe driver uses EFI_MEMORY_WP for write protection,
> according to UEFI spec, we should use EFI_MEMORY_RO for write protection.
> The EFI_MEMORY_WP is the cache attribute instead of memory attribute.
>
> Cc: Leif Lindholm <leif.lindholm@linaro.org>
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Jiewen Yao <jiewen.yao@intel.com>
> ---
>  ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c              |  2 +-
>  ArmPkg/Drivers/CpuDxe/Arm/Mmu.c                  | 13 +++++--------
>  ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c             |  4 ++--
>  ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c |  2 +-
>  4 files changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
> b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
> index d8bb419..4703b33 100644
> --- a/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
> +++ b/ArmPkg/Drivers/CpuDxe/AArch64/Mmu.c
> @@ -224,7 +224,7 @@ EfiAttributeToArmAttribute (
>    ArmAttributes |= TT_AF;
>
>    // Determine protection attributes
> -  if (EfiAttributes & EFI_MEMORY_WP) {
> +  if (EfiAttributes & EFI_MEMORY_RO) {
>      ArmAttributes |= TT_AP_RO_RO;
>    }
>
> diff --git a/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c
> b/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c
> index 14fc22d..348b205 100644
> --- a/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c
> +++ b/ArmPkg/Drivers/CpuDxe/Arm/Mmu.c
> @@ -62,7 +62,7 @@ SectionToGcdAttributes (
>    // determine protection attributes
>    switch(SectionAttributes & TT_DESCRIPTOR_SECTION_AP_MASK) {
>      case TT_DESCRIPTOR_SECTION_AP_NO_NO: // no read, no write
> -      //*GcdAttributes |= EFI_MEMORY_WP | EFI_MEMORY_RP;
> +      //*GcdAttributes |= EFI_MEMORY_RO | EFI_MEMORY_RP;
>        break;
>
>      case TT_DESCRIPTOR_SECTION_AP_RW_NO:
> @@ -73,7 +73,7 @@ SectionToGcdAttributes (
>      // read only cases map to write-protect
>      case TT_DESCRIPTOR_SECTION_AP_RO_NO:
>      case TT_DESCRIPTOR_SECTION_AP_RO_RO:
> -      *GcdAttributes |= EFI_MEMORY_WP;
> +      *GcdAttributes |= EFI_MEMORY_RO;
>        break;
>
>      default:
> @@ -126,7 +126,7 @@ PageToGcdAttributes (
>    // determine protection attributes
>    switch(PageAttributes & TT_DESCRIPTOR_PAGE_AP_MASK) {
>      case TT_DESCRIPTOR_PAGE_AP_NO_NO: // no read, no write
> -      //*GcdAttributes |= EFI_MEMORY_WP | EFI_MEMORY_RP;
> +      //*GcdAttributes |= EFI_MEMORY_RO | EFI_MEMORY_RP;
>        break;
>
>      case TT_DESCRIPTOR_PAGE_AP_RW_NO:
> @@ -137,7 +137,7 @@ PageToGcdAttributes (
>      // read only cases map to write-protect
>      case TT_DESCRIPTOR_PAGE_AP_RO_NO:
>      case TT_DESCRIPTOR_PAGE_AP_RO_RO:
> -      *GcdAttributes |= EFI_MEMORY_WP;
> +      *GcdAttributes |= EFI_MEMORY_RO;
>        break;
>
>      default:
> @@ -730,9 +730,6 @@ EfiAttributeToArmAttribute (
>        ArmAttributes =
> TT_DESCRIPTOR_SECTION_CACHE_POLICY_WRITE_BACK_ALLOC; // TEX [2:0] =
> 001, C=1, B=1
>        break;
>
> -    case EFI_MEMORY_WP:
> -    case EFI_MEMORY_XP:
> -    case EFI_MEMORY_RP:
>      case EFI_MEMORY_UCE:
>      default:
>        // Cannot be implemented UEFI definition unclear for ARM
> @@ -743,7 +740,7 @@ EfiAttributeToArmAttribute (
>    }
>
>    // Determine protection attributes
> -  if (EfiAttributes & EFI_MEMORY_WP) {
> +  if (EfiAttributes & EFI_MEMORY_RO) {
>      ArmAttributes |= TT_DESCRIPTOR_SECTION_AP_RO_RO;
>    } else {
>      ArmAttributes |= TT_DESCRIPTOR_SECTION_AP_RW_RW;
> diff --git a/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
> b/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
> index 723604d..acdf1eb 100644
> --- a/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
> +++ b/ArmPkg/Drivers/CpuDxe/CpuMmuCommon.c
> @@ -236,7 +236,7 @@ CpuConvertPagesToUncachedVirtualAddress (
>    // be the PCI address. Code should always use the CPU address, and we will
> or in VirtualMask
>    // to that address.
>    //
> -  Status = SetMemoryAttributes (Address, Length, EFI_MEMORY_WP, 0);
> +  Status = SetMemoryAttributes (Address, Length, EFI_MEMORY_RO, 0);
>    if (!EFI_ERROR (Status)) {
>      Status = SetMemoryAttributes (Address | VirtualMask, Length,
> EFI_MEMORY_UC, VirtualMask);
>    }
> @@ -264,7 +264,7 @@ CpuReconvertPages (
>    //
>    // Unmap the aliased Address
>    //
> -  Status = SetMemoryAttributes (Address | VirtualMask, Length,
> EFI_MEMORY_WP, 0);
> +  Status = SetMemoryAttributes (Address | VirtualMask, Length,
> EFI_MEMORY_RO, 0);
>    if (!EFI_ERROR (Status)) {
>      //
>      // Restore atttributes
> diff --git a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> index 540069a..5bc80a6 100644
> --- a/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> +++ b/ArmPkg/Library/ArmMmuLib/AArch64/ArmMmuLibCore.c
> @@ -89,7 +89,7 @@ PageAttributeToGcdAttribute (
>    // Determine protection attributes
>    if (((PageAttributes & TT_AP_MASK) == TT_AP_NO_RO) || ((PageAttributes
> & TT_AP_MASK) == TT_AP_RO_RO)) {
>      // Read only cases map to write-protect
> -    GcdAttributes |= EFI_MEMORY_WP;
> +    GcdAttributes |= EFI_MEMORY_RO;
>    }
>
>    // Process eXecute Never attribute
> --
> 2.7.4.windows.1
>
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