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Subject: Re: [edk2-devel] [PATCH v2 1/1] SecurityPkg/Tcg2Smm: Initialize local Status variable
To: devel@edk2.groups.io, lersek@redhat.com
Cc: Jiewen Yao <jiewen.yao@intel.com>, Jian J Wang <jian.j.wang@intel.com>,
 Qi Zhang <qi1.zhang@intel.com>, Rahul Kumar <rahul1.kumar@intel.com>,
 Kun Qin <kuqin12@gmail.com>
References: <20210406181207.8731-1-mikuback@linux.microsoft.com>
 <2e577197-2381-4849-f4db-4e2f992cae66@redhat.com>
From: "Michael Kubacki" <mikuback@linux.microsoft.com>
Message-ID: <8aa2a8ff-06b9-6efe-46cd-7e987adc2b90@linux.microsoft.com>
Date: Mon, 12 Apr 2021 10:54:22 -0700
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Hi Laszlo and SecurityPkg maintainers,

This is a relatively straightforward patch. Please let me know if 
anything else is needed for you to submit it.

Thanks,
Michael

On 4/7/2021 9:06 AM, Laszlo Ersek wrote:
> 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
> 
> 
> 
> 
>