Re: [PATCH] EmulatorPkg/WinHost: Add EFI_BUFFER_TOO_SMALL for return status.

["Ni, Ray" <ray.ni@intel.com>]

Guomin,
It's OK to do a partial read. There is no requirement for a single read
that returns all the file content back to caller.

Some comments to your commit message:
Besides, the commit message is too simple. It should indicate what was
wrong in the code and what's your expected behavior.

The Bugzilla comments are very detailed actually.

Thanks,
Ray

> -----Original Message-----
> From: Jiang, Guomin <guomin.jiang@intel.com>
> Sent: Friday, March 20, 2020 2:56 PM
> To: devel@edk2.groups.io
> Cc: Justen, Jordan L <jordan.l.justen@intel.com>; Andrew Fish
> <afish@apple.com>; Ni, Ray <ray.ni@intel.com>
> Subject: [PATCH] EmulatorPkg/WinHost: Add EFI_BUFFER_TOO_SMALL for
> return status.
> 
> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2605
> 
> I think it is necessary that check the buffer size before ReadFile, it
> will inform the caller that they should provide more buffer.
> 
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Andrew Fish <afish@apple.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Signed-off-by: Guomin Jiang <guomin.jiang@intel.com>
> ---
>  EmulatorPkg/Win/Host/WinFileSystem.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/EmulatorPkg/Win/Host/WinFileSystem.c
> b/EmulatorPkg/Win/Host/WinFileSystem.c
> index f6b06b1c92..6fb86db6b3 100644
> --- a/EmulatorPkg/Win/Host/WinFileSystem.c
> +++ b/EmulatorPkg/Win/Host/WinFileSystem.c
> @@ -1159,6 +1159,12 @@ WinNtFileRead (
>        }
> 
>      }
> 
> 
> 
> +    if (FileSize > *BufferSize) {
> 
> +      Status = EFI_BUFFER_TOO_SMALL;
> 
> +      *BufferSize = FileSize;
> 
> +      goto Done;
> 
> +    }
> 
> +
> 
>      Status = ReadFile (
> 
>        PrivateFile->LHandle,
> 
>        Buffer,
> 
> --
> 2.25.1.windows.1