Re: [edk2-platforms][PATCH v3 10/11] Ext4Pkg: Fixes build on MSVC

["Pedro Falcato" <pedro.falcato@gmail.com>]

On Fri, Jan 27, 2023 at 9:29 AM Savva Mitrofanov <savvamtr@gmail.com> wrote:
>
> Accessing array using index of uint64 type makes MSVC compiler to
> include `__allmul` function in NOOPT which is not referenced in IA32.
> So we null-terminates string using ReadSize, which should be equal to
> SymlinkSizeTmp after correct reading. Also adds missing MultU64x32
> in Ext4Read.
>
> Cc: Marvin Häuser <mhaeuser@posteo.de>
> Cc: Pedro Falcato <pedro.falcato@gmail.com>
> Cc: Vitaly Cheptsov <vit9696@protonmail.com>
> Fixes: 7c46116b0e18 ("Ext4Pkg: Add ext2/3 support")
> Fixes: e81432fbacb7 ("Ext4Pkg: Add symbolic links support")
> Signed-off-by: Savva Mitrofanov <savvamtr@gmail.com>
> ---
>  Features/Ext4Pkg/Ext4Dxe/Inode.c   |  4 ++--
>  Features/Ext4Pkg/Ext4Dxe/Symlink.c | 12 ++++++------
>  2 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/Features/Ext4Pkg/Ext4Dxe/Inode.c b/Features/Ext4Pkg/Ext4Dxe/Inode.c
> index 90e3eb88f523..8db051d3c444 100644
> --- a/Features/Ext4Pkg/Ext4Dxe/Inode.c
> +++ b/Features/Ext4Pkg/Ext4Dxe/Inode.c
> @@ -152,7 +152,7 @@ Ext4Read (
>        } else {
>          // Uninitialized extents behave exactly the same as file holes, except they have
>          // blocks already allocated to them.
> -        HoleLen = (Ext4GetExtentLength (&Extent) * Partition->BlockSize) - HoleOff;
> +        HoleLen = MultU64x32 (Ext4GetExtentLength (&Extent), Partition->BlockSize) - HoleOff;
>        }
>
>        WasRead = HoleLen > RemainingRead ? RemainingRead : (UINTN)HoleLen;
> @@ -166,7 +166,7 @@ Ext4Read (
>                             Partition->BlockSize
>                             );
>        ExtentLengthBytes  = Extent.ee_len * Partition->BlockSize;
> -      ExtentLogicalBytes = (UINT64)Extent.ee_block * Partition->BlockSize;
> +      ExtentLogicalBytes = MultU64x32 ((UINT64)Extent.ee_block, Partition->BlockSize);
>        ExtentOffset       = CurrentSeek - ExtentLogicalBytes;
>        ExtentMayRead      = (UINTN)(ExtentLengthBytes - ExtentOffset);
>
> diff --git a/Features/Ext4Pkg/Ext4Dxe/Symlink.c b/Features/Ext4Pkg/Ext4Dxe/Symlink.c
> index 19b357ac6ba0..8b1511a38b55 100644
> --- a/Features/Ext4Pkg/Ext4Dxe/Symlink.c
> +++ b/Features/Ext4Pkg/Ext4Dxe/Symlink.c
> @@ -1,7 +1,7 @@
>  /** @file
>    Symbolic links routines
>
> -  Copyright (c) 2022 Savva Mitrofanov All rights reserved.
> +  Copyright (c) 2022-2023 Savva Mitrofanov All rights reserved.
>    SPDX-License-Identifier: BSD-2-Clause-Patent
>  **/
>
> @@ -155,11 +155,6 @@ Ext4ReadSlowSymlink (
>      return Status;
>    }
>
> -  //
> -  // Add null-terminator
> -  //
> -  SymlinkTmp[SymlinkSizeTmp] = '\0';
> -
>    if (SymlinkSizeTmp != ReadSize) {
>      DEBUG ((
>        DEBUG_FS,
> @@ -168,6 +163,11 @@ Ext4ReadSlowSymlink (
>      return EFI_VOLUME_CORRUPTED;
>    }
>
> +  //
> +  // Add null-terminator
> +  //
Sidenote: please don't use this comment style, I know it's prevalent
in EDK2 and EDK2 platforms but Ext4Pkg just does:
// Comment

Also, why are you bringing this null-termination down here?
> +  SymlinkTmp[ReadSize] = '\0';
> +
>    *AsciiSymlinkSize = SymlinkAllocateSize;
>    *AsciiSymlink     = SymlinkTmp;
>
> --
> 2.39.0
>


-- 
Pedro