Re: [edk2-devel] [PATCH 35/35] UefiPayloadPkg/BlSupportDxe: fix ReserveResourceInGcd() calls

["Guo Dong" <guo.dong@intel.com>]

This is not dead code. 
This actual bug didn't cause issues since BlSupportDxe just allocate resources reported from bootloaders. 
Anyway, this is a great enhancement from spec to capture such bugs.

Thanks,
Guo

> -----Original Message-----
> From: Philippe Mathieu-Daudé [mailto:philmd@redhat.com]
> Sent: Monday, September 23, 2019 8:08 AM
> To: devel@edk2.groups.io; lersek@redhat.com
> Cc: You, Benjamin <benjamin.you@intel.com>; Dong, Guo
> <guo.dong@intel.com>; Ma, Maurice <maurice.ma@intel.com>
> Subject: Re: [edk2-devel] [PATCH 35/35] UefiPayloadPkg/BlSupportDxe: fix
> ReserveResourceInGcd() calls
> 
> On 9/17/19 9:49 PM, Laszlo Ersek wrote:
> > The last parameter of ReserveResourceInGcd() is "ImageHandle",
> > forwarded in turn to gDS->AllocateMemorySpace() or gDS-
> >AllocateIoSpace() as "owner"
> > image handle.
> >
> > But BlDxeEntryPoint() passes "SystemTable" as "ImageHandle".
> >
> > Compilers have not flagged it because EFI_HANDLE (the type of
> > "ImageHandle") is unfortunately specified as (VOID*), and
> > (EFI_SYSTEM_TABLE*) converts to (VOID*) silently.
> >
> > Hand the entry point function's "ImageHandle" parameter to
> > ReserveResourceInGcd(). This fixes an actual bug.
> 
> Wow very buggy, so I assume this is mostly dead code, right?
> 
> > Cc: Benjamin You <benjamin.you@intel.com>
> > Cc: Guo Dong <guo.dong@intel.com>
> > Cc: Maurice Ma <maurice.ma@intel.com>
> > Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> > ---
> >
> > Notes:
> >     build-tested only
> >
> >  UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
> > b/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
> > index bcee4cd9bc41..28dfc8fc5545 100644
> > --- a/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
> > +++ b/UefiPayloadPkg/BlSupportDxe/BlSupportDxe.c
> > @@ -106,10 +106,10 @@ BlDxeEntryPoint (
> >    //
> >    // Report MMIO/IO Resources
> >    //
> > -  Status = ReserveResourceInGcd (TRUE,
> > EfiGcdMemoryTypeMemoryMappedIo, 0xFEC00000, SIZE_4KB, 0,
> SystemTable);
> > // IOAPIC
> > +  Status = ReserveResourceInGcd (TRUE,
> > + EfiGcdMemoryTypeMemoryMappedIo, 0xFEC00000, SIZE_4KB, 0,
> > + ImageHandle); // IOAPIC
> >    ASSERT_EFI_ERROR (Status);
> >
> > -  Status = ReserveResourceInGcd (TRUE,
> > EfiGcdMemoryTypeMemoryMappedIo, 0xFED00000, SIZE_1KB, 0,
> SystemTable);
> > // HPET
> > +  Status = ReserveResourceInGcd (TRUE,
> > + EfiGcdMemoryTypeMemoryMappedIo, 0xFED00000, SIZE_1KB, 0,
> > + ImageHandle); // HPET
> >    ASSERT_EFI_ERROR (Status);
> >
> >    //
> >
> 
> Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>