Re: [edk2-devel][Patch] StandaloneMmPkg/FvLib: Support large file with EFI_FFS_FILE_HEADER2.

["Ard Biesheuvel" <ardb@kernel.org>]

On Thu, 9 Dec 2021 at 07:51, Wei6 Xu <wei6.xu@intel.com> wrote:
>
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3769
>
> Current FvLib will hit parse issue when encountering LARGE file, then
> ignore latter ffs/section, thus causing required drivers not being
> dispatched. Therefore, need to add support for EFI_FFS_FILE_HEADER2
> and EFI_COMMON_SECTION_HEADER2 in FvLib to fix this issue.
>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Sami Mujawar <sami.mujawar@arm.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Supreeth Venkatesh <supreeth.venkatesh@arm.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Signed-off-by: Wei6 Xu <wei6.xu@intel.com>
> ---

Is this an issue in practice? How large does the FV that is being
dispatched into MM context have to be in order for this issue to
trigger?


>  StandaloneMmPkg/Library/FvLib/FvLib.c | 65 ++++++++++++++++++++++++-----------
>  1 file changed, 45 insertions(+), 20 deletions(-)
>
> diff --git a/StandaloneMmPkg/Library/FvLib/FvLib.c b/StandaloneMmPkg/Library/FvLib/FvLib.c
> index aa36a35eff..89504b9ee9 100644
> --- a/StandaloneMmPkg/Library/FvLib/FvLib.c
> +++ b/StandaloneMmPkg/Library/FvLib/FvLib.c
> @@ -1,8 +1,8 @@
>  /** @file
>
> -Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2015 - 2021, Intel Corporation. All rights reserved.<BR>
>  Copyright (c) 2016 - 2018, ARM Limited. All rights reserved.<BR>
>
>  SPDX-License-Identifier: BSD-2-Clause-Patent
>
>  **/
> @@ -61,22 +61,24 @@ CalculateHeaderChecksum (
>    )
>  {
>    UINT8  *ptr;
>    UINTN  Index;
>    UINT8  Sum;
> +  UINTN  Size;
>
> -  Sum = 0;
> -  ptr = (UINT8 *)FileHeader;
> +  Sum  = 0;
> +  ptr  = (UINT8 *)FileHeader;
> +  Size = IS_FFS_FILE2 (FileHeader) ? sizeof (EFI_FFS_FILE_HEADER2) : sizeof (EFI_FFS_FILE_HEADER);
>
> -  for (Index = 0; Index < sizeof (EFI_FFS_FILE_HEADER) - 3; Index += 4) {
> +  for (Index = 0; Index < Size - 3; Index += 4) {
>      Sum = (UINT8)(Sum + ptr[Index]);
>      Sum = (UINT8)(Sum + ptr[Index + 1]);
>      Sum = (UINT8)(Sum + ptr[Index + 2]);
>      Sum = (UINT8)(Sum + ptr[Index + 3]);
>    }
>
> -  for ( ; Index < sizeof (EFI_FFS_FILE_HEADER); Index++) {
> +  for ( ; Index < Size; Index++) {
>      Sum = (UINT8)(Sum + ptr[Index]);
>    }
>
>    //
>    // State field (since this indicates the different state of file).
> @@ -155,11 +157,12 @@ FfsFindNextFile (
>    } else {
>      //
>      // Length is 24 bits wide so mask upper 8 bits
>      // FileLength is adjusted to FileOccupiedSize as it is 8 byte aligned.
>      //
> -    FileLength       = FFS_FILE_SIZE (*FileHeader);
> +    FileLength = IS_FFS_FILE2 (*FileHeader) ?
> +                 FFS_FILE2_SIZE (*FileHeader) : FFS_FILE_SIZE (*FileHeader);
>      FileOccupiedSize = GET_OCCUPIED_SIZE (FileLength, 8);
>      FfsFileHeader    = (EFI_FFS_FILE_HEADER *)((UINT8 *)*FileHeader + FileOccupiedSize);
>    }
>
>    FileOffset = (UINT32)((UINT8 *)FfsFileHeader - (UINT8 *)FwVolHeader);
> @@ -170,18 +173,25 @@ FfsFindNextFile (
>      //
>      FileState = GetFileState (ErasePolarity, FfsFileHeader);
>
>      switch (FileState) {
>        case EFI_FILE_HEADER_INVALID:
> -        FileOffset   += sizeof (EFI_FFS_FILE_HEADER);
> -        FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + sizeof (EFI_FFS_FILE_HEADER));
> +        if (IS_FFS_FILE2 (FfsFileHeader)) {
> +          FileOffset   += sizeof (EFI_FFS_FILE_HEADER2);
> +          FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + sizeof (EFI_FFS_FILE_HEADER2));
> +        } else {
> +          FileOffset   += sizeof (EFI_FFS_FILE_HEADER);
> +          FfsFileHeader = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + sizeof (EFI_FFS_FILE_HEADER));
> +        }
> +
>          break;
>
>        case EFI_FILE_DATA_VALID:
>        case EFI_FILE_MARKED_FOR_UPDATE:
>          if (CalculateHeaderChecksum (FfsFileHeader) == 0) {
> -          FileLength       = FFS_FILE_SIZE (FfsFileHeader);
> +          FileLength = IS_FFS_FILE2 (FfsFileHeader) ?
> +                       FFS_FILE2_SIZE (FfsFileHeader) : FFS_FILE_SIZE (FfsFileHeader);
>            FileOccupiedSize = GET_OCCUPIED_SIZE (FileLength, 8);
>
>            if ((SearchType == FfsFileHeader->Type) || (SearchType == EFI_FV_FILETYPE_ALL)) {
>              *FileHeader = FfsFileHeader;
>
> @@ -195,11 +205,12 @@ FfsFindNextFile (
>          }
>
>          break;
>
>        case EFI_FILE_DELETED:
> -        FileLength       = FFS_FILE_SIZE (FfsFileHeader);
> +        FileLength = IS_FFS_FILE2 (FfsFileHeader) ?
> +                     FFS_FILE2_SIZE (FfsFileHeader) : FFS_FILE_SIZE (FfsFileHeader);
>          FileOccupiedSize = GET_OCCUPIED_SIZE (FileLength, 8);
>          FileOffset      += FileOccupiedSize;
>          FfsFileHeader    = (EFI_FFS_FILE_HEADER *)((UINT8 *)FfsFileHeader + FileOccupiedSize);
>          break;
>
> @@ -251,11 +262,11 @@ FindFfsSectionInSections (
>
>      CurrentAddress = EndOfSection;
>
>      Section = (EFI_COMMON_SECTION_HEADER *)(UINTN)CurrentAddress;
>
> -    Size = SECTION_SIZE (Section);
> +    Size = IS_SECTION2 (Section) ? SECTION2_SIZE (Section) : SECTION_SIZE (Section);
>      if (Size < sizeof (*Section)) {
>        return EFI_VOLUME_CORRUPTED;
>      }
>
>      EndOfSection = CurrentAddress + Size;
> @@ -304,13 +315,17 @@ FfsFindSection (
>    //
>    // Size is 24 bits wide so mask upper 8 bits.
>    //    Does not include FfsFileHeader header size
>    // FileSize is adjusted to FileOccupiedSize as it is 8 byte aligned.
>    //
> -  Section   = (EFI_COMMON_SECTION_HEADER *)(FfsFileHeader + 1);
> -  FileSize  = FFS_FILE_SIZE (FfsFileHeader);
> -  FileSize -= sizeof (EFI_FFS_FILE_HEADER);
> +  if (IS_FFS_FILE2 (FfsFileHeader)) {
> +    Section  = (EFI_COMMON_SECTION_HEADER *)((EFI_FFS_FILE_HEADER2 *)FfsFileHeader + 1);
> +    FileSize = FFS_FILE2_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER2);
> +  } else {
> +    Section  = (EFI_COMMON_SECTION_HEADER *)(FfsFileHeader + 1);
> +    FileSize = FFS_FILE_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER);
> +  }
>
>    Status = FindFfsSectionInSections (
>               Section,
>               FileSize,
>               SectionType,
> @@ -349,29 +364,39 @@ FfsFindSectionData (
>    //
>    // Size is 24 bits wide so mask upper 8 bits.
>    // Does not include FfsFileHeader header size
>    // FileSize is adjusted to FileOccupiedSize as it is 8 byte aligned.
>    //
> -  Section   = (EFI_COMMON_SECTION_HEADER *)(FfsFileHeader + 1);
> -  FileSize  = FFS_FILE_SIZE (FfsFileHeader);
> -  FileSize -= sizeof (EFI_FFS_FILE_HEADER);
> +  if (IS_FFS_FILE2 (FfsFileHeader)) {
> +    Section  = (EFI_COMMON_SECTION_HEADER *)((EFI_FFS_FILE_HEADER2 *)FfsFileHeader + 1);
> +    FileSize = FFS_FILE2_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER2);
> +  } else {
> +    Section  = (EFI_COMMON_SECTION_HEADER *)(FfsFileHeader + 1);
> +    FileSize = FFS_FILE_SIZE (FfsFileHeader) - sizeof (EFI_FFS_FILE_HEADER);
> +  }
>
>    *SectionData = NULL;
>    ParsedLength = 0;
>    while (ParsedLength < FileSize) {
>      if (Section->Type == SectionType) {
> -      *SectionData     = (VOID *)(Section + 1);
> -      *SectionDataSize = SECTION_SIZE (Section);
> +      if (IS_SECTION2 (Section)) {
> +        *SectionData     = (VOID *)((EFI_COMMON_SECTION_HEADER2 *)Section + 1);
> +        *SectionDataSize = SECTION2_SIZE (Section);
> +      } else {
> +        *SectionData     = (VOID *)(Section + 1);
> +        *SectionDataSize = SECTION_SIZE (Section);
> +      }
> +
>        return EFI_SUCCESS;
>      }
>
>      //
>      // Size is 24 bits wide so mask upper 8 bits.
>      // SectionLength is adjusted it is 4 byte aligned.
>      // Go to the next section
>      //
> -    SectionLength = SECTION_SIZE (Section);
> +    SectionLength = IS_SECTION2 (Section) ? SECTION2_SIZE (Section) : SECTION_SIZE (Section);
>      SectionLength = GET_OCCUPIED_SIZE (SectionLength, 4);
>
>      ParsedLength += SectionLength;
>      Section       = (EFI_COMMON_SECTION_HEADER *)((UINT8 *)Section + SectionLength);
>    }
> --
> 2.16.2.windows.1
>