Re: [staging/FmpDevicePkg-master][PATCH] FmpDevicePkg FmpDxe: Initialize DeviceLibLowestSupportedVersion

["Zeng, Star" <star.zeng@intel.com>]

Normally, FmpDeviceGetLowestSupportedVersion() should not touch input DeviceLibLowestSupportedVersion when returning an error.
If we think it is legal that DeviceLibLowestSupportedVersion could be updated in an error case by FmpDeviceGetLowestSupportedVersion(), then we could only add new line below before calling FmpDeviceGetLowestSupportedVersion().

DeviceLibLowestSupportedVersion = DEFAULT_LOWESTSUPPORTEDVERSION;


Thanks,
Star

-----Original Message-----
From: Kinney, Michael D 
Sent: Monday, July 30, 2018 1:36 PM
To: Zeng, Star <star.zeng@intel.com>; edk2-devel@lists.01.org; Kinney, Michael D <michael.d.kinney@intel.com>
Subject: RE: [staging/FmpDevicePkg-master][PATCH] FmpDevicePkg FmpDxe: Initialize DeviceLibLowestSupportedVersion

Star,

I do not think the logic is identical.

The function FmpDeviceGetLowestSupportedVersion() could modify the value of DeviceLibLowestSupportedVersion and return an error.

Mike

> -----Original Message-----
> From: Zeng, Star
> Sent: Sunday, July 29, 2018 7:51 PM
> To: edk2-devel@lists.01.org
> Cc: Kinney, Michael D <michael.d.kinney@intel.com>; Zeng, Star 
> <star.zeng@intel.com>
> Subject: [staging/FmpDevicePkg-master][PATCH]
> FmpDevicePkg FmpDxe: Initialize
> DeviceLibLowestSupportedVersion
> 
> Update the title to include "[staging/FmpDevicePkg- master]".
> 
> Thanks,
> Star
> -----Original Message-----
> From: Zeng, Star
> Sent: Monday, July 30, 2018 10:50 AM
> To: edk2-devel@lists.01.org
> Cc: Zeng, Star <star.zeng@intel.com>; Kinney, Michael D 
> <michael.d.kinney@intel.com>
> Subject: [PATCH] FmpDevicePkg FmpDxe: Initialize 
> DeviceLibLowestSupportedVersion
> 
> Some static tool reports
> "DeviceLibLowestSupportedVersion" is used, but is uninitialized. It is 
> false positive reporting based because DeviceLibLowestSupportedVersion 
> will have assigned value after
> FmpDeviceGetLowestSupportedVersion() returns SUCCESS.
> 
> This patch refines the code to initialize 
> DeviceLibLowestSupportedVersion to DEFAULT_LOWESTSUPPORTEDVERSION 
> before calling FmpDeviceGetLowestSupportedVersion().
> It can pass the static tool's check.
> 
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Star Zeng <star.zeng@intel.com>
> ---
>  FmpDevicePkg/FmpDxe/FmpDxe.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/FmpDevicePkg/FmpDxe/FmpDxe.c 
> b/FmpDevicePkg/FmpDxe/FmpDxe.c index
> b25a1511c70c..4868f80de2b9 100644
> --- a/FmpDevicePkg/FmpDxe/FmpDxe.c
> +++ b/FmpDevicePkg/FmpDxe/FmpDxe.c
> @@ -229,10 +229,8 @@ GetLowestSupportedVersion (
>    //
>    // Check the FmpDeviceLib
>    //
> -  Status = FmpDeviceGetLowestSupportedVersion
> (&DeviceLibLowestSupportedVersion);
> -  if (EFI_ERROR (Status)) {
> -    DeviceLibLowestSupportedVersion =
> DEFAULT_LOWESTSUPPORTEDVERSION;
> -  }
> +  DeviceLibLowestSupportedVersion =
> DEFAULT_LOWESTSUPPORTEDVERSION;
> + FmpDeviceGetLowestSupportedVersion
> (&DeviceLibLowestSupportedVersion);
> 
>    if (DeviceLibLowestSupportedVersion > ReturnLsv) {
>      ReturnLsv = DeviceLibLowestSupportedVersion;
> --
> 2.7.0.windows.1