Re: [edk2-devel] [PATCH 1/1] MdeModulePkg/DxeIplPeim: Initialize pointer PageMapLevel5Entry

["Liming Gao" <liming.gao@intel.com>]

Shenglei:
  The change is good. I agree to add comments for this change purpose like BZ https://bugzilla.tianocore.org/show_bug.cgi?id=607

  With this change, Reviewed-by: Liming Gao <liming.gao@intel.com>.

Thanks
Liming
> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of Laszlo Ersek
> Sent: Thursday, August 15, 2019 1:12 AM
> To: devel@edk2.groups.io; Zhang, Shenglei <shenglei.zhang@intel.com>
> Cc: Bi, Dandan <dandan.bi@intel.com>; Gao, Liming <liming.gao@intel.com>; Wu, Hao A <hao.a.wu@intel.com>
> Subject: Re: [edk2-devel] [PATCH 1/1] MdeModulePkg/DxeIplPeim: Initialize pointer PageMapLevel5Entry
> 
> On 08/14/19 09:37, Zhang, Shenglei wrote:
> > Initialize PageMapLevel5Entry at the beginning of the function.
> >
> > This commit will fix a GCC 4.8.5 build failure introduced by commit
> > b3527dedc3951f061c5a73cb4fb2b0f95f47e08b.
> >
> > OvmfPkg build failure wtih gcc 4.8.5 still exists at latest edk2 version.
> > The commit 46f8a6891606746ca8b1e684ac379ce271306dc0 seems not to fix
> > the build failure completely.
> >
> > Cc: Dandan Bi <dandan.bi@intel.com>
> > Cc: Liming Gao <liming.gao@intel.com>
> > Cc: Hao A Wu <hao.a.wu@intel.com>
> > Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
> > ---
> >  MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
> > index 2389f3eb485b..aae80536ac3d 100644
> > --- a/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
> > +++ b/MdeModulePkg/Core/DxeIplPeim/X64/VirtualMemory.c
> > @@ -652,6 +652,8 @@ CreateIdentityMappingPageTables (
> >    UINT64                                        AddressEncMask;
> >    IA32_CR4                                      Cr4;
> >
> > +  PageMapLevel5Entry = NULL;
> > +
> >    //
> >    // Make sure AddressEncMask is contained to smallest supported address field
> >    //
> >
> 
> If you are convinced that we need this assignment *only* for suppressing
> an invalid compiler warning, then please add a comment about it:
> 
>   //
>   // set PageMapLevel5Entry to suppress incorrect compiler/analyzer
>   // warnings
>   //
> 
> Related documentation BZ:
> 
> https://bugzilla.tianocore.org/show_bug.cgi?id=607
> 
> ... Just a suggestion from my side; I defer to the MdeModulePkg maintainers.
> 
> Thanks
> Laszlo
> 
>