Re: [edk2-devel] [PATCH 5/5] StandaloneMmPkg/StandaloneMmCoreEntryPoint: relocate StMM core on the fly

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

Acked-by: Jiewen Yao <Jiewen.yao@intel.com>

I hope ARM expert can review this to double confirm.

Thank you
Yao Jiewen

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Ard
> Biesheuvel
> Sent: Wednesday, June 10, 2020 4:18 PM
> To: devel@edk2.groups.io
> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com>; Yao,
> Jiewen <jiewen.yao@intel.com>; Sami Mujawar <sami.mujawar@arm.com>;
> Ilias Apalodimas <ilias.apalodimas@linaro.org>
> Subject: [edk2-devel] [PATCH 5/5]
> StandaloneMmPkg/StandaloneMmCoreEntryPoint: relocate StMM core on the
> fly
> 
> Apply PE/COFF fixups when starting up the standalone MM core, so that
> it can execute at any address regardless of the link time address.
> 
> Note that this requires the PE/COFF image to be emitted with its
> relocation section preserved. Special care is taken to ensure that
> TE images are dealt with correctly as well.
> 
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
> ---
>  StandaloneMmPkg/Include/Library/AArch64/StandaloneMmCoreEntryPoint.h
> |  2 ++
> 
> StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/SetPermissi
> ons.c             | 11 +++++++---
> 
> StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/Standalone
> MmCoreEntryPoint.c | 22 ++++++++++++++++++++
>  3 files changed, 32 insertions(+), 3 deletions(-)
> 
> diff --git
> a/StandaloneMmPkg/Include/Library/AArch64/StandaloneMmCoreEntryPoint.h
> b/StandaloneMmPkg/Include/Library/AArch64/StandaloneMmCoreEntryPoint.h
> index 494bcf3dc28f..a3420699e6f1 100644
> ---
> a/StandaloneMmPkg/Include/Library/AArch64/StandaloneMmCoreEntryPoint.h
> +++
> b/StandaloneMmPkg/Include/Library/AArch64/StandaloneMmCoreEntryPoint.h
> @@ -82,6 +82,7 @@ EFI_STATUS
>  EFIAPI
> 
>  UpdateMmFoundationPeCoffPermissions (
> 
>    IN  CONST PE_COFF_LOADER_IMAGE_CONTEXT      *ImageContext,
> 
> +  IN  EFI_PHYSICAL_ADDRESS                    ImageBase,
> 
>    IN  UINT32                                  SectionHeaderOffset,
> 
>    IN  CONST  UINT16                           NumberOfSections,
> 
>    IN  REGION_PERMISSION_UPDATE_FUNC           TextUpdater,
> 
> @@ -107,6 +108,7 @@ EFIAPI
>  GetStandaloneMmCorePeCoffSections (
> 
>    IN        VOID                            *TeData,
> 
>    IN  OUT   PE_COFF_LOADER_IMAGE_CONTEXT    *ImageContext,
> 
> +      OUT   EFI_PHYSICAL_ADDRESS            *ImageBase,
> 
>    IN  OUT   UINT32                          *SectionHeaderOffset,
> 
>    IN  OUT   UINT16                          *NumberOfSections
> 
>    );
> 
> diff --git
> a/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/SetPermis
> sions.c
> b/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/SetPermis
> sions.c
> index 00f49c9d0558..bf9650d54629 100644
> ---
> a/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/SetPermis
> sions.c
> +++
> b/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/SetPermis
> sions.c
> @@ -29,6 +29,7 @@ EFI_STATUS
>  EFIAPI
> 
>  UpdateMmFoundationPeCoffPermissions (
> 
>    IN  CONST PE_COFF_LOADER_IMAGE_CONTEXT      *ImageContext,
> 
> +  IN  EFI_PHYSICAL_ADDRESS                    ImageBase,
> 
>    IN  UINT32                                  SectionHeaderOffset,
> 
>    IN  CONST  UINT16                           NumberOfSections,
> 
>    IN  REGION_PERMISSION_UPDATE_FUNC           TextUpdater,
> 
> @@ -87,7 +88,7 @@ UpdateMmFoundationPeCoffPermissions (
>      // if it is a writeable section then mark it appropriately as well.
> 
>      //
> 
>      if ((SectionHeader.Characteristics & EFI_IMAGE_SCN_MEM_EXECUTE) == 0) {
> 
> -      Base = ImageContext->ImageAddress + SectionHeader.VirtualAddress;
> 
> +      Base = ImageBase + SectionHeader.VirtualAddress;
> 
> 
> 
>        TextUpdater (Base, SectionHeader.Misc.VirtualSize);
> 
> 
> 
> @@ -153,6 +154,7 @@ STATIC
>  EFI_STATUS
> 
>  GetPeCoffSectionInformation (
> 
>    IN  OUT   PE_COFF_LOADER_IMAGE_CONTEXT      *ImageContext,
> 
> +      OUT   EFI_PHYSICAL_ADDRESS              *ImageBase,
> 
>        OUT   UINT32                            *SectionHeaderOffset,
> 
>        OUT   UINT16                            *NumberOfSections
> 
>    )
> 
> @@ -212,6 +214,7 @@ GetPeCoffSectionInformation (
>      return Status;
> 
>    }
> 
> 
> 
> +  *ImageBase = ImageContext->ImageAddress;
> 
>    if (!ImageContext->IsTeImage) {
> 
>      ASSERT (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE);
> 
> 
> 
> @@ -232,7 +235,7 @@ GetPeCoffSectionInformation (
>    } else {
> 
>      *SectionHeaderOffset = (UINTN)(sizeof (EFI_TE_IMAGE_HEADER));
> 
>      *NumberOfSections = Hdr.Te->NumberOfSections;
> 
> -    ImageContext->ImageAddress -= (UINT32)Hdr.Te->StrippedSize - sizeof
> (EFI_TE_IMAGE_HEADER);
> 
> +    *ImageBase -= (UINT32)Hdr.Te->StrippedSize - sizeof
> (EFI_TE_IMAGE_HEADER);
> 
>    }
> 
>    return RETURN_SUCCESS;
> 
>  }
> 
> @@ -242,6 +245,7 @@ EFIAPI
>  GetStandaloneMmCorePeCoffSections (
> 
>    IN        VOID                            *TeData,
> 
>    IN  OUT   PE_COFF_LOADER_IMAGE_CONTEXT    *ImageContext,
> 
> +      OUT   EFI_PHYSICAL_ADDRESS            *ImageBase,
> 
>    IN  OUT   UINT32                          *SectionHeaderOffset,
> 
>    IN  OUT   UINT16                          *NumberOfSections
> 
>    )
> 
> @@ -255,7 +259,8 @@ GetStandaloneMmCorePeCoffSections (
> 
> 
>    DEBUG ((DEBUG_INFO, "Found Standalone MM PE data - 0x%x\n", TeData));
> 
> 
> 
> -  Status = GetPeCoffSectionInformation (ImageContext, SectionHeaderOffset,
> NumberOfSections);
> 
> +  Status = GetPeCoffSectionInformation (ImageContext, ImageBase,
> 
> +             SectionHeaderOffset, NumberOfSections);
> 
>    if (EFI_ERROR (Status)) {
> 
>      DEBUG ((DEBUG_ERROR, "Unable to locate Standalone MM Core PE-COFF
> Section information - %r\n", Status));
> 
>      return Status;
> 
> diff --git
> a/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/Standalon
> eMmCoreEntryPoint.c
> b/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/Standalon
> eMmCoreEntryPoint.c
> index 20723385113f..9cecfa667b90 100644
> ---
> a/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/Standalon
> eMmCoreEntryPoint.c
> +++
> b/StandaloneMmPkg/Library/StandaloneMmCoreEntryPoint/AArch64/Standalon
> eMmCoreEntryPoint.c
> @@ -225,6 +225,7 @@ _ModuleEntryPoint (
>    VOID                                    *HobStart;
> 
>    VOID                                    *TeData;
> 
>    UINTN                                   TeDataSize;
> 
> +  EFI_PHYSICAL_ADDRESS                    ImageBase;
> 
> 
> 
>    // Get Secure Partition Manager Version Information
> 
>    Status = GetSpmVersion ();
> 
> @@ -253,6 +254,7 @@ _ModuleEntryPoint (
>    Status = GetStandaloneMmCorePeCoffSections (
> 
>               TeData,
> 
>               &ImageContext,
> 
> +             &ImageBase,
> 
>               &SectionHeaderOffset,
> 
>               &NumberOfSections
> 
>               );
> 
> @@ -261,10 +263,21 @@ _ModuleEntryPoint (
>      goto finish;
> 
>    }
> 
> 
> 
> +  //
> 
> +  // ImageBase may deviate from ImageContext.ImageAddress if we are
> dealing
> 
> +  // with a TE image, in which case the latter points to the actual offset
> 
> +  // of the image, whereas ImageBase refers to the address where the image
> 
> +  // would start if the stripped PE headers were still in place. In either
> 
> +  // case, we need to fix up ImageBase so it refers to the actual current
> 
> +  // load address.
> 
> +  //
> 
> +  ImageBase += (UINTN)TeData - ImageContext.ImageAddress;
> 
> +
> 
>    // Update the memory access permissions of individual sections in the
> 
>    // Standalone MM core module
> 
>    Status = UpdateMmFoundationPeCoffPermissions (
> 
>               &ImageContext,
> 
> +             ImageBase,
> 
>               SectionHeaderOffset,
> 
>               NumberOfSections,
> 
>               ArmSetMemoryRegionNoExec,
> 
> @@ -276,6 +289,15 @@ _ModuleEntryPoint (
>      goto finish;
> 
>    }
> 
> 
> 
> +  if (ImageContext.ImageAddress != (UINTN)TeData) {
> 
> +    ImageContext.ImageAddress = (UINTN)TeData;
> 
> +    ArmSetMemoryRegionNoExec (ImageBase, SIZE_4KB);
> 
> +    ArmClearMemoryRegionReadOnly (ImageBase, SIZE_4KB);
> 
> +
> 
> +    Status = PeCoffLoaderRelocateImage (&ImageContext);
> 
> +    ASSERT_EFI_ERROR (Status);
> 
> +  }
> 
> +
> 
>    //
> 
>    // Create Hoblist based upon boot information passed by privileged software
> 
>    //
> 
> --
> 2.26.2
> 
> 
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