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

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

[Michael Kubacki]

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;
-- 
2.28.0.windows.1

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

[Laszlo Ersek]

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

Re: [edk2-devel] [PATCH v2 1/1] SecurityPkg/Tcg2Smm: Initialize local Status variable

[Michael Kubacki]

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
> 
> 
> 
> 
> 

Re: [edk2-devel] [PATCH v2 1/1] SecurityPkg/Tcg2Smm: Initialize local Status variable

[Wang, Jian J]

Pushed @ 54211ab10fcd8532b49f4024ebdb601a8eb07e3e

Regards,
Jian

> -----Original Message-----
> From: Michael Kubacki <mikuback@linux.microsoft.com>
> Sent: Tuesday, April 13, 2021 1:54 AM
> To: devel@edk2.groups.io; lersek@redhat.com
> Cc: Yao, Jiewen <jiewen.yao@intel.com>; Wang, Jian J <jian.j.wang@intel.com>;
> Zhang, Qi1 <qi1.zhang@intel.com>; Kumar, Rahul1 <rahul1.kumar@intel.com>;
> Kun Qin <kuqin12@gmail.com>
> Subject: Re: [edk2-devel] [PATCH v2 1/1] SecurityPkg/Tcg2Smm: Initialize local
> Status variable
> 
> 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
> >
> >
> >
> > 
> >