[PATCH] MdeModulePkg: Initialize local variable value before they are used

[PATCH] MdeModulePkg: Initialize local variable value before they are used

[gaoliming]

This change is to fix the compiler error on GCC49 release build.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
---
 MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c                 | 1 +
 .../Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c    | 1 +
 2 files changed, 2 insertions(+)

diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
index e99a812a44..0779f94f9e 100644
--- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
+++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
@@ -1122,6 +1122,7 @@ AhciDmaTransfer (
 
   Map   = NULL;
   PciIo = Instance->PciIo;
+  Status = EFI_SUCCESS;
 
   if (PciIo == NULL) {
     return EFI_INVALID_PARAMETER;
diff --git a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
index 0c9299c8b0..7822cbf4bb 100644
--- a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
+++ b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
@@ -117,6 +117,7 @@ CreateBasicVariablePolicy (
 
   // Now we've gotta determine the total size of the buffer required for
   // the VariablePolicy structure.
+  NameSize  = 0;
   TotalSize = sizeof( VARIABLE_POLICY_ENTRY );
   if (Name != NULL) {
     NameSize = StrnSizeS( Name, MAX_UINT16 );
-- 
2.27.0.windows.1

Re: [PATCH] MdeModulePkg: Initialize local variable value before they are used

[Wu, Hao A]

> -----Original Message-----
> From: Liming Gao <gaoliming@byosoft.com.cn>
> Sent: Tuesday, March 9, 2021 9:24 AM
> To: devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A <hao.a.wu@intel.com>
> Subject: [PATCH] MdeModulePkg: Initialize local variable value before they are
> used
> 
> This change is to fix the compiler error on GCC49 release build.


Thanks Liming. The patch looks good to me:
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>

I have one question that I think both the reports are false positives.
Do you think it will be better to add this information in the commit message?

Best Regards,
Hao Wu


> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
> ---
>  MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c                 | 1 +
>  .../Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c    | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> index e99a812a44..0779f94f9e 100644
> --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> @@ -1122,6 +1122,7 @@ AhciDmaTransfer (
> 
>    Map   = NULL;
>    PciIo = Instance->PciIo;
> +  Status = EFI_SUCCESS;
> 
>    if (PciIo == NULL) {
>      return EFI_INVALID_PARAMETER;
> diff --git
> a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> index 0c9299c8b0..7822cbf4bb 100644
> ---
> a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> +++
> b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> @@ -117,6 +117,7 @@ CreateBasicVariablePolicy (
> 
>    // Now we've gotta determine the total size of the buffer required for
>    // the VariablePolicy structure.
> +  NameSize  = 0;
>    TotalSize = sizeof( VARIABLE_POLICY_ENTRY );
>    if (Name != NULL) {
>      NameSize = StrnSizeS( Name, MAX_UINT16 );
> --
> 2.27.0.windows.1
> 

回复: [PATCH] MdeModulePkg: Initialize local variable value before they are used

[gaoliming]

Hao:
  Yes. I agree. I will add this information when I merge it. 

Thanks
Liming
> -----邮件原件-----
> 发件人: Wu, Hao A <hao.a.wu@intel.com>
> 发送时间: 2021年3月9日 10:10
> 收件人: Liming Gao <gaoliming@byosoft.com.cn>; devel@edk2.groups.io
> 抄送: Wang, Jian J <jian.j.wang@intel.com>
> 主题: RE: [PATCH] MdeModulePkg: Initialize local variable value before
they
> are used
> 
> > -----Original Message-----
> > From: Liming Gao <gaoliming@byosoft.com.cn>
> > Sent: Tuesday, March 9, 2021 9:24 AM
> > To: devel@edk2.groups.io
> > Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> <hao.a.wu@intel.com>
> > Subject: [PATCH] MdeModulePkg: Initialize local variable value before
they
> are
> > used
> >
> > This change is to fix the compiler error on GCC49 release build.
> 
> 
> Thanks Liming. The patch looks good to me:
> Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
> 
> I have one question that I think both the reports are false positives.
> Do you think it will be better to add this information in the commit
message?
> 
> Best Regards,
> Hao Wu
> 
> 
> >
> > Cc: Jian J Wang <jian.j.wang@intel.com>
> > Cc: Hao A Wu <hao.a.wu@intel.com>
> > Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
> > ---
> >  MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> | 1 +
> >  .../Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c    | 1 +
> >  2 files changed, 2 insertions(+)
> >
> > diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > index e99a812a44..0779f94f9e 100644
> > --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > @@ -1122,6 +1122,7 @@ AhciDmaTransfer (
> >
> >    Map   = NULL;
> >    PciIo = Instance->PciIo;
> > +  Status = EFI_SUCCESS;
> >
> >    if (PciIo == NULL) {
> >      return EFI_INVALID_PARAMETER;
> > diff --git
> >
> a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> >
> b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > index 0c9299c8b0..7822cbf4bb 100644
> > ---
> >
> a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > +++
> >
> b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > @@ -117,6 +117,7 @@ CreateBasicVariablePolicy (
> >
> >    // Now we've gotta determine the total size of the buffer required
for
> >    // the VariablePolicy structure.
> > +  NameSize  = 0;
> >    TotalSize = sizeof( VARIABLE_POLICY_ENTRY );
> >    if (Name != NULL) {
> >      NameSize = StrnSizeS( Name, MAX_UINT16 );
> > --
> > 2.27.0.windows.1
> >

Re: [edk2-devel] 回复: [PATCH] MdeModulePkg: Initialize local variable value before they are used

[Wu, Hao A]

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of gaoliming
> Sent: Thursday, March 11, 2021 9:10 AM
> To: Wu, Hao A <hao.a.wu@intel.com>; devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>
> Subject: [edk2-devel] 回复: [PATCH] MdeModulePkg: Initialize local variable
> value before they are used
> 
> Hao:
>   Yes. I agree. I will add this information when I merge it.


Hello Liming,

Thanks a lot.

Best Regards,
Hao Wu


> 
> Thanks
> Liming
> > -----邮件原件-----
> > 发件人: Wu, Hao A <hao.a.wu@intel.com>
> > 发送时间: 2021年3月9日 10:10
> > 收件人: Liming Gao <gaoliming@byosoft.com.cn>; devel@edk2.groups.io
> > 抄送: Wang, Jian J <jian.j.wang@intel.com>
> > 主题: RE: [PATCH] MdeModulePkg: Initialize local variable value before
> they
> > are used
> >
> > > -----Original Message-----
> > > From: Liming Gao <gaoliming@byosoft.com.cn>
> > > Sent: Tuesday, March 9, 2021 9:24 AM
> > > To: devel@edk2.groups.io
> > > Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> > <hao.a.wu@intel.com>
> > > Subject: [PATCH] MdeModulePkg: Initialize local variable value before
> they
> > are
> > > used
> > >
> > > This change is to fix the compiler error on GCC49 release build.
> >
> >
> > Thanks Liming. The patch looks good to me:
> > Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
> >
> > I have one question that I think both the reports are false positives.
> > Do you think it will be better to add this information in the commit
> message?
> >
> > Best Regards,
> > Hao Wu
> >
> >
> > >
> > > Cc: Jian J Wang <jian.j.wang@intel.com>
> > > Cc: Hao A Wu <hao.a.wu@intel.com>
> > > Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
> > > ---
> > >  MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > | 1 +
> > >  .../Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c    | 1 +
> > >  2 files changed, 2 insertions(+)
> > >
> > > diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > > b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > > index e99a812a44..0779f94f9e 100644
> > > --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > > +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > > @@ -1122,6 +1122,7 @@ AhciDmaTransfer (
> > >
> > >    Map   = NULL;
> > >    PciIo = Instance->PciIo;
> > > +  Status = EFI_SUCCESS;
> > >
> > >    if (PciIo == NULL) {
> > >      return EFI_INVALID_PARAMETER;
> > > diff --git
> > >
> > a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > >
> > b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > > index 0c9299c8b0..7822cbf4bb 100644
> > > ---
> > >
> > a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > > +++
> > >
> > b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > > @@ -117,6 +117,7 @@ CreateBasicVariablePolicy (
> > >
> > >    // Now we've gotta determine the total size of the buffer required
> for
> > >    // the VariablePolicy structure.
> > > +  NameSize  = 0;
> > >    TotalSize = sizeof( VARIABLE_POLICY_ENTRY );
> > >    if (Name != NULL) {
> > >      NameSize = StrnSizeS( Name, MAX_UINT16 );
> > > --
> > > 2.27.0.windows.1
> > >
> 
> 
> 
> 
> 
> 
> 

Re: [edk2-devel] [PATCH] MdeModulePkg: Initialize local variable value before they are used

[Laszlo Ersek]

Hi Liming,

On 03/09/21 02:24, gaoliming wrote:
> This change is to fix the compiler error on GCC49 release build.
> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
> ---
>  MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c                 | 1 +
>  .../Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c    | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> index e99a812a44..0779f94f9e 100644
> --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> @@ -1122,6 +1122,7 @@ AhciDmaTransfer (
>  
>    Map   = NULL;
>    PciIo = Instance->PciIo;
> +  Status = EFI_SUCCESS;
>  
>    if (PciIo == NULL) {
>      return EFI_INVALID_PARAMETER;
> diff --git a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> index 0c9299c8b0..7822cbf4bb 100644
> --- a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> +++ b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> @@ -117,6 +117,7 @@ CreateBasicVariablePolicy (
>  
>    // Now we've gotta determine the total size of the buffer required for
>    // the VariablePolicy structure.
> +  NameSize  = 0;
>    TotalSize = sizeof( VARIABLE_POLICY_ENTRY );
>    if (Name != NULL) {
>      NameSize = StrnSizeS( Name, MAX_UINT16 );
> 

(1) we have a bugzilla ticket related to this (or more precisely,
overlapping AtaAtapiPassThru):

https://bugzilla.tianocore.org/show_bug.cgi?id=3228

I think mentioning the BZ in the commit message might make sense.

(2) Recently we have used a special comment format for such assignments.
Namely:

  //
  // Set Status to suppress incorrect compiler/analyzer warnings
  //
  Status = EFI_SUCCESS;

Hao already requested that we should document that we only suppress
compiler false positives with these assignments -- they are not needed
functionally. However, I think saying so in the commit message *only* is
not sufficient. I think we should stick with the above code-comment
format (which we've used recently in several places).

Thanks!
Laszlo

回复: [edk2-devel] [PATCH] MdeModulePkg: Initialize local variable value before they are used

[gaoliming]

Laszlo:
  I agree your comments. I will update the patch to include the comments in code and commit message. 

Thanks
Liming
> -----邮件原件-----
> 发件人: Laszlo Ersek <lersek@redhat.com>
> 发送时间: 2021年3月12日 1:22
> 收件人: devel@edk2.groups.io; gaoliming@byosoft.com.cn
> 抄送: Jian J Wang <jian.j.wang@intel.com>; Hao A Wu
> <hao.a.wu@intel.com>; sergei@posteo.net
> 主题: Re: [edk2-devel] [PATCH] MdeModulePkg: Initialize local variable value
> before they are used
> 
> Hi Liming,
> 
> On 03/09/21 02:24, gaoliming wrote:
> > This change is to fix the compiler error on GCC49 release build.
> >
> > Cc: Jian J Wang <jian.j.wang@intel.com>
> > Cc: Hao A Wu <hao.a.wu@intel.com>
> > Signed-off-by: Liming Gao <gaoliming@byosoft.com.cn>
> > ---
> >  MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> | 1 +
> >  .../Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c    | 1 +
> >  2 files changed, 2 insertions(+)
> >
> > diff --git a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > index e99a812a44..0779f94f9e 100644
> > --- a/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > +++ b/MdeModulePkg/Bus/Ata/AtaAtapiPassThru/AhciMode.c
> > @@ -1122,6 +1122,7 @@ AhciDmaTransfer (
> >
> >    Map   = NULL;
> >    PciIo = Instance->PciIo;
> > +  Status = EFI_SUCCESS;
> >
> >    if (PciIo == NULL) {
> >      return EFI_INVALID_PARAMETER;
> > diff --git
> a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > index 0c9299c8b0..7822cbf4bb 100644
> > ---
> a/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > +++
> b/MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.c
> > @@ -117,6 +117,7 @@ CreateBasicVariablePolicy (
> >
> >    // Now we've gotta determine the total size of the buffer required for
> >    // the VariablePolicy structure.
> > +  NameSize  = 0;
> >    TotalSize = sizeof( VARIABLE_POLICY_ENTRY );
> >    if (Name != NULL) {
> >      NameSize = StrnSizeS( Name, MAX_UINT16 );
> >
> 
> (1) we have a bugzilla ticket related to this (or more precisely,
> overlapping AtaAtapiPassThru):
> 
> https://bugzilla.tianocore.org/show_bug.cgi?id=3228
> 
> I think mentioning the BZ in the commit message might make sense.
> 
> (2) Recently we have used a special comment format for such assignments.
> Namely:
> 
>   //
>   // Set Status to suppress incorrect compiler/analyzer warnings
>   //
>   Status = EFI_SUCCESS;
> 
> Hao already requested that we should document that we only suppress
> compiler false positives with these assignments -- they are not needed
> functionally. However, I think saying so in the commit message *only* is
> not sufficient. I think we should stick with the above code-comment
> format (which we've used recently in several places).
> 
> Thanks!
> Laszlo