Re: [edk2-platforms][PATCH V1 1/1] IntelSiliconPkg/IntelVTdDxe: Fix NULL pointer dereference

["Ni, Ray" <ray.ni@intel.com>]

sorry for the false alarm.

The issue I met before is not like this one. There is no unreachable code issue.

Reviewed-by: Ray Ni <ray.ni@intel.com>

Thanks,
Ray

> -----Original Message-----
> From: Ni, Ray
> Sent: Monday, August 26, 2019 4:52 PM
> To: Kubacki, Michael A <michael.a.kubacki@intel.com>; devel@edk2.groups.io
> Cc: Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>
> Subject: RE: [edk2-platforms][PATCH V1 1/1] IntelSiliconPkg/IntelVTdDxe: Fix NULL pointer dereference
> 
> Michael,
> 
> 
> > -----Original Message-----
> > From: Kubacki, Michael A
> > Sent: Friday, August 23, 2019 7:54 PM
> > To: devel@edk2.groups.io
> > Cc: Ni, Ray <ray.ni@intel.com>; Chaganty, Rangasai V <rangasai.v.chaganty@intel.com>
> > Subject: [edk2-platforms][PATCH V1 1/1] IntelSiliconPkg/IntelVTdDxe: Fix NULL pointer dereference
> >
> > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2116
> >
> > Cc: Ray Ni <ray.ni@intel.com>
> > Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com>
> > Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
> > ---
> >  Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c | 19 +++++++++++--------
> >  1 file changed, 11 insertions(+), 8 deletions(-)
> >
> > diff --git a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> > b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> > index 956ebb2d3d..9b6135ef94 100644
> > --- a/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> > +++ b/Silicon/Intel/IntelSiliconPkg/Feature/VTd/IntelVTdDxe/DmaProtection.c
> > @@ -158,10 +158,13 @@ ProcessRequestedAccessAttribute (
> >  }
> >
> >  /**
> > -  return the UEFI memory information.
> > +  Return UEFI memory map information.
> > +
> > +  @param[out] Below4GMemoryLimit  The below 4GiB memory limit address or 0 if insufficient resources exist to
> > +                                  determine the address.
> > +  @param[out] Above4GMemoryLimit  The above 4GiB memory limit address or 0 if insufficient resources exist to
> > +                                  determine the address.
> >
> > -  @param[out] Below4GMemoryLimit  The below 4GiB memory limit
> > -  @param[out] Above4GMemoryLimit  The above 4GiB memory limit
> >  **/
> >  VOID
> >  ReturnUefiMemoryMap (
> > @@ -206,7 +209,11 @@ ReturnUefiMemoryMap (
> >      // we process bogus entries and create bogus E820 entries.
> >      //
> >      EfiMemoryMap = (EFI_MEMORY_DESCRIPTOR *) AllocatePool (EfiMemoryMapSize);
> > -    ASSERT (EfiMemoryMap != NULL);
> > +    if (EfiMemoryMap == NULL) {
> > +      ASSERT (EfiMemoryMap != NULL);
> 
> Above line may trigger a unreachable code error from some static code scanner.
> How about move assertion to the line before if?
> 
> > +      return;
> > +    }
> > +
> >      Status = gBS->GetMemoryMap (
> >                      &EfiMemoryMapSize,
> >                      EfiMemoryMap,
> > @@ -218,7 +225,6 @@ ReturnUefiMemoryMap (
> >        FreePool (EfiMemoryMap);
> >      }
> >    } while (Status == EFI_BUFFER_TOO_SMALL);
> > -
> >    ASSERT_EFI_ERROR (Status);
> >
> >    //
> > @@ -242,9 +248,6 @@ ReturnUefiMemoryMap (
> >      NextEfiEntry  = NEXT_MEMORY_DESCRIPTOR (EfiEntry, EfiDescriptorSize);
> >    }
> >
> > -  //
> > -  //
> > -  //
> >    DEBUG ((DEBUG_INFO, "MemoryMap:\n"));
> >    EfiEntry        = EfiMemoryMap;
> >    EfiMemoryMapEnd = (EFI_MEMORY_DESCRIPTOR *) ((UINT8 *) EfiMemoryMap + EfiMemoryMapSize);
> > --
> > 2.16.2.windows.1