Re: [PATCH v2 1/1] SecurityPkg/Tcg2Smm: Initialize local Status variable

["Laszlo Ersek" <lersek@redhat.com>]

On 04/06/21 20:12, mikuback@linux.microsoft.com wrote:
> From: Michael Kubacki <michael.kubacki@microsoft.com>
> 
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3277
> 
> Initializes the Status variable in TcgMmReadyToLock().
> 
> Fixes a Clang build failure:
> Tcg2Smm.c - SecurityPkg\Tcg\Tcg2Smm\Tcg2Smm.c:254:7: error:
> variable 'Status' is used uninitialized whenever 'if'
> condition is false [-Werror,-Wsometimes-uninitialized]
> 
> Initializing this variable is required to address a practical
> scenario in which the return value of TcgMmReadyToLock() is
> undefined based on conditional evaluation in the function.
> 
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Qi Zhang <qi1.zhang@intel.com>
> Cc: Rahul Kumar <rahul1.kumar@intel.com>
> Cc: Kun Qin <kun.q@outlook.com>
> Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
> Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
> ---
> 
> Notes:
>     V2 change:
>     
>     Clarify in commit message that the issue reported by Clang is not
>     solely a false positive.
> 
>  SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
> index 589c08794bcf..f49eccb0bdf4 100644
> --- a/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
> +++ b/SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
> @@ -253,6 +253,8 @@ TcgMmReadyToLock (
>  {
>    EFI_STATUS Status;
>  
> +  Status = EFI_SUCCESS;
> +
>    if (mReadyToLockHandle != NULL) {
>      Status = gMmst->MmiHandlerUnRegister (mReadyToLockHandle);
>      mReadyToLockHandle = NULL;
> 

Awesome, thanks!

I've also managed to look at the code now.

Reviewed-by: Laszlo Ersek <lersek@redhat.com>

Thanks
Laszlo