[PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[Gerd Hoffmann]

BufferPages is UINTN, so we need "%Lu" when printing it.

Fixes: 4f441d024bee ("UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling")
Reported-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
index cf69161caa4b..08663b1b1ab4 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
@@ -880,7 +880,7 @@ PiCpuSmmEntry (
     BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize * (mMaxNumberOfCpus - 1));
     Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
     if (Buffer == NULL) {
-      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
+      DEBUG ((DEBUG_ERROR, "Failed to allocate %Lu pages.\n", BufferPages));
       CpuDeadLoop ();
       return EFI_OUT_OF_RESOURCES;
     }
-- 
2.39.2

Re: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[Ni, Ray]

Gerd,
"%d" tells "int" type value is in the stack.
This actually works in both 32bit and 64bit case assuming the BufferPages is less than MAX_UINT32.

But if using "%Lu", it tells that "uint_64" type value is in the stack.
This precisely describes the stack content in 64bit mode.
But it may print random value in the stack as high-32 bit in 32bit mode.

@Kinney, Michael D, any comments?

Thanks,
Ray


> -----Original Message-----
> From: Gerd Hoffmann <kraxel@redhat.com>
> Sent: Friday, March 24, 2023 9:42 PM
> To: devel@edk2.groups.io
> Cc: Dong, Eric <eric.dong@intel.com>; Gerd Hoffmann <kraxel@redhat.com>;
> Oliver Steffen <osteffen@redhat.com>; Kumar, Rahul R
> <rahul.r.kumar@intel.com>; Ni, Ray <ray.ni@intel.com>; Pawel Polawski
> <ppolawsk@redhat.com>; Laszlo Ersek <lersek@redhat.com>
> Subject: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string
> 
> BufferPages is UINTN, so we need "%Lu" when printing it.
> 
> Fixes: 4f441d024bee ("UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling")
> Reported-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> index cf69161caa4b..08663b1b1ab4 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> @@ -880,7 +880,7 @@ PiCpuSmmEntry (
>      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize *
> (mMaxNumberOfCpus - 1));
>      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
>      if (Buffer == NULL) {
> -      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
> +      DEBUG ((DEBUG_ERROR, "Failed to allocate %Lu pages.\n",
> BufferPages));
>        CpuDeadLoop ();
>        return EFI_OUT_OF_RESOURCES;
>      }
> --
> 2.39.2

Re: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[Michael D Kinney]

1) Keep %d and change BufferPages to type UINT32.
2) Change to %Ld and change BufferPages to type UINT64.

Mike

> -----Original Message-----
> From: Ni, Ray <ray.ni@intel.com>
> Sent: Friday, March 24, 2023 7:00 AM
> To: Gerd Hoffmann <kraxel@redhat.com>; devel@edk2.groups.io; Kinney, Michael D <michael.d.kinney@intel.com>
> Cc: Dong, Eric <eric.dong@intel.com>; Oliver Steffen <osteffen@redhat.com>; Kumar, Rahul R <rahul.r.kumar@intel.com>;
> Pawel Polawski <ppolawsk@redhat.com>; Laszlo Ersek <lersek@redhat.com>
> Subject: RE: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string
> 
> Gerd,
> "%d" tells "int" type value is in the stack.
> This actually works in both 32bit and 64bit case assuming the BufferPages is less than MAX_UINT32.
> 
> But if using "%Lu", it tells that "uint_64" type value is in the stack.
> This precisely describes the stack content in 64bit mode.
> But it may print random value in the stack as high-32 bit in 32bit mode.
> 
> @Kinney, Michael D, any comments?
> 
> Thanks,
> Ray
> 
> 
> > -----Original Message-----
> > From: Gerd Hoffmann <kraxel@redhat.com>
> > Sent: Friday, March 24, 2023 9:42 PM
> > To: devel@edk2.groups.io
> > Cc: Dong, Eric <eric.dong@intel.com>; Gerd Hoffmann <kraxel@redhat.com>;
> > Oliver Steffen <osteffen@redhat.com>; Kumar, Rahul R
> > <rahul.r.kumar@intel.com>; Ni, Ray <ray.ni@intel.com>; Pawel Polawski
> > <ppolawsk@redhat.com>; Laszlo Ersek <lersek@redhat.com>
> > Subject: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string
> >
> > BufferPages is UINTN, so we need "%Lu" when printing it.
> >
> > Fixes: 4f441d024bee ("UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling")
> > Reported-by: Laszlo Ersek <lersek@redhat.com>
> > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > ---
> >  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > index cf69161caa4b..08663b1b1ab4 100644
> > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > @@ -880,7 +880,7 @@ PiCpuSmmEntry (
> >      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize *
> > (mMaxNumberOfCpus - 1));
> >      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
> >      if (Buffer == NULL) {
> > -      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
> > +      DEBUG ((DEBUG_ERROR, "Failed to allocate %Lu pages.\n",
> > BufferPages));
> >        CpuDeadLoop ();
> >        return EFI_OUT_OF_RESOURCES;
> >      }
> > --
> > 2.39.2

Re: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[Michael D Kinney]

And from Laszlo's responses, 3 total options.

1) Keep %d and change BufferPages to type UINT32.
2) Change to %Ld and change BufferPages to type UINT64.
3) Change to %Ld and typecast BufferPages to UINT64 in DEBUG().

All 3 will work.  Best suggestion is (3) from Laszlo.

Mike

> -----Original Message-----
> From: Kinney, Michael D <michael.d.kinney@intel.com>
> Sent: Friday, March 24, 2023 8:27 AM
> To: Ni, Ray <ray.ni@intel.com>; Gerd Hoffmann <kraxel@redhat.com>; devel@edk2.groups.io
> Cc: Dong, Eric <eric.dong@intel.com>; Oliver Steffen <osteffen@redhat.com>; Kumar, Rahul R <rahul.r.kumar@intel.com>;
> Pawel Polawski <ppolawsk@redhat.com>; Laszlo Ersek <lersek@redhat.com>; Kinney, Michael D <michael.d.kinney@intel.com>
> Subject: RE: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string
> 
> 1) Keep %d and change BufferPages to type UINT32.
> 2) Change to %Ld and change BufferPages to type UINT64.> 
> Mike
> 
> > -----Original Message-----
> > From: Ni, Ray <ray.ni@intel.com>
> > Sent: Friday, March 24, 2023 7:00 AM
> > To: Gerd Hoffmann <kraxel@redhat.com>; devel@edk2.groups.io; Kinney, Michael D <michael.d.kinney@intel.com>
> > Cc: Dong, Eric <eric.dong@intel.com>; Oliver Steffen <osteffen@redhat.com>; Kumar, Rahul R <rahul.r.kumar@intel.com>;
> > Pawel Polawski <ppolawsk@redhat.com>; Laszlo Ersek <lersek@redhat.com>
> > Subject: RE: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string
> >
> > Gerd,
> > "%d" tells "int" type value is in the stack.
> > This actually works in both 32bit and 64bit case assuming the BufferPages is less than MAX_UINT32.
> >
> > But if using "%Lu", it tells that "uint_64" type value is in the stack.
> > This precisely describes the stack content in 64bit mode.
> > But it may print random value in the stack as high-32 bit in 32bit mode.
> >
> > @Kinney, Michael D, any comments?
> >
> > Thanks,
> > Ray
> >
> >
> > > -----Original Message-----
> > > From: Gerd Hoffmann <kraxel@redhat.com>
> > > Sent: Friday, March 24, 2023 9:42 PM
> > > To: devel@edk2.groups.io
> > > Cc: Dong, Eric <eric.dong@intel.com>; Gerd Hoffmann <kraxel@redhat.com>;
> > > Oliver Steffen <osteffen@redhat.com>; Kumar, Rahul R
> > > <rahul.r.kumar@intel.com>; Ni, Ray <ray.ni@intel.com>; Pawel Polawski
> > > <ppolawsk@redhat.com>; Laszlo Ersek <lersek@redhat.com>
> > > Subject: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string
> > >
> > > BufferPages is UINTN, so we need "%Lu" when printing it.
> > >
> > > Fixes: 4f441d024bee ("UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling")
> > > Reported-by: Laszlo Ersek <lersek@redhat.com>
> > > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > > ---
> > >  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > > index cf69161caa4b..08663b1b1ab4 100644
> > > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> > > @@ -880,7 +880,7 @@ PiCpuSmmEntry (
> > >      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize *
> > > (mMaxNumberOfCpus - 1));
> > >      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
> > >      if (Buffer == NULL) {
> > > -      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
> > > +      DEBUG ((DEBUG_ERROR, "Failed to allocate %Lu pages.\n",
> > > BufferPages));
> > >        CpuDeadLoop ();
> > >        return EFI_OUT_OF_RESOURCES;
> > >      }
> > > --
> > > 2.39.2

Re: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[Laszlo Ersek]

Hi Gerd,

On 3/24/23 14:41, Gerd Hoffmann wrote:
> BufferPages is UINTN, so we need "%Lu" when printing it.
>
> Fixes: 4f441d024bee ("UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling")
> Reported-by: Laszlo Ersek <lersek@redhat.com>
> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> ---
>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> index cf69161caa4b..08663b1b1ab4 100644
> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
> @@ -880,7 +880,7 @@ PiCpuSmmEntry (
>      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize * (mMaxNumberOfCpus - 1));
>      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
>      if (Buffer == NULL) {
> -      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
> +      DEBUG ((DEBUG_ERROR, "Failed to allocate %Lu pages.\n", BufferPages));
>        CpuDeadLoop ();
>        return EFI_OUT_OF_RESOURCES;
>      }

you missed part of my off-list comment; it was:

> "BufferPages" has type UINTN, it should not be printed with "%d" (%d
> is for INT32). The proper way to print a UINTN value with DEBUG is to
> cast the value to UINT64, and print that with %Lu (or %Lx).

Refer to "cast the value to UINT64".

UINTN is either UINT32 or UINT64. There is no format specifier that's
dedicated specifically to UINTN. You can't use fixed %u with UINTN
because that will be wrong on 64-bit platforms (%u takes UINT32 but
UINTN will be UINT64), and you can't use fixed %Lu with UINTN because
that will be wrong on 32-bit platforms (%Lu takes UINT64 but UINTN will
be UINT32). The proper way is to (1) cast the UINTN to UINT64 first
(which will be a no-op on 64-bit platforms, and it will widen UINT32 to
UINT64 on 32-bit platforms, without changing the value), and then (2)
print *that* (the now certainly UINT64 value) with %Lu.

  DEBUG ((
    DEBUG_ERROR,
    "Failed to allocate %Lu pages.\n",
    (UINT64)BufferPages
    ));

(

Here's an idea:

> diff --git a/MdePkg/Include/Library/PrintLib.h b/MdePkg/Include/Library/PrintLib.h
> index 8d523cac528d..bdacec9777f0 100644
> --- a/MdePkg/Include/Library/PrintLib.h
> +++ b/MdePkg/Include/Library/PrintLib.h
> @@ -197,6 +197,17 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
>  #define PREFIX_ZERO   0x20
>  #define RADIX_HEX     0x80
>
> +#if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_LOONGARCH64) || \
> +    defined (MDE_CPU_RISCV64) || defined (MDE_CPU_X64)
> +#define PRIuN "%Lu"
> +#define PRIxN "%Lx"
> +#elif defined (MDE_CPU_ARM) || defined (MDE_CPU_IA32)
> +#define PRIuN "%Lu"
> +#define PRIxN "%Lx"
> +#else
> +#error Unknown CPU architecture.
> +#endif
> +
>  /**
>    Produces a Null-terminated Unicode string in an output buffer based on
>    a Null-terminated Unicode format string and a VA_LIST argument list.

and then you could do

  DEBUG ((
    DEBUG_ERROR,
    "Failed to allocate " PRIuN " pages.\n",
    BufferPages
    ));

(Note the lack of a cast.)

Note: I do not cover MDE_CPU_EBC above, in "PrintLib.h". I don't know
how EBC (EFI Byte Code) deals with 32-bit vs. 64-bit. The UEFI 2.10 spec
says in "22.1.1 Processor Architecture Independence": "64-bit C source
code" and "The interpreter handles 32 vs. 64 bit issues". Unfortunately,
that doesn't seem to help: it does not help us decide the size of UINTN
at compile time.

More precisely: if you check "MdePkg/Include/Ebc/ProcessorBind.h", it
contains:

> ///
> /// Signed value of native width.  (4 bytes on supported 32-bit processor instructions,
> /// 8 bytes on supported 64-bit processor instructions)
> /// "long" type scales to the processor native size with EBC compiler
> ///
> typedef long INTN;
> ///
> /// The unsigned value of native width.  (4 bytes on supported 32-bit processor instructions;
> /// 8 bytes on supported 64-bit processor instructions)
> /// "long" type scales to the processor native size with the EBC compiler.
> ///
> typedef unsigned long UINTN;

In other words, the size of UINTN *is* chosen at compile time, but the
choice cannot be determined from MDE_CPU_EBC. And no other macro that
"MdePkg/Include/Ebc/ProcessorBind.h" defines seems to be suitable for
investigation with #if preprocessing directives.

Anyway: the explicit (UINT64) cast with the open-coded %Lu conversion
specifier will work fine on EBC as well, so I suggest sticking with
that.

)

Laszlo

Re: [PATCH 1/1] UefiCpuPkg/PiSmmCpuDxeSmm: fix format string

[Laszlo Ersek]

On 3/24/23 15:56, Laszlo Ersek wrote:
> Hi Gerd,
> 
> On 3/24/23 14:41, Gerd Hoffmann wrote:
>> BufferPages is UINTN, so we need "%Lu" when printing it.
>>
>> Fixes: 4f441d024bee ("UefiCpuPkg/PiSmmCpuDxeSmm: fix error handling")
>> Reported-by: Laszlo Ersek <lersek@redhat.com>
>> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>> ---
>>  UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
>> index cf69161caa4b..08663b1b1ab4 100644
>> --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
>> +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c
>> @@ -880,7 +880,7 @@ PiCpuSmmEntry (
>>      BufferPages = EFI_SIZE_TO_PAGES (SIZE_32KB + TileSize * (mMaxNumberOfCpus - 1));
>>      Buffer      = AllocateAlignedCodePages (BufferPages, SIZE_4KB);
>>      if (Buffer == NULL) {
>> -      DEBUG ((DEBUG_ERROR, "Failed to allocate %d pages.\n", BufferPages));
>> +      DEBUG ((DEBUG_ERROR, "Failed to allocate %Lu pages.\n", BufferPages));
>>        CpuDeadLoop ();
>>        return EFI_OUT_OF_RESOURCES;
>>      }
> 
> you missed part of my off-list comment; it was:
> 
>> "BufferPages" has type UINTN, it should not be printed with "%d" (%d
>> is for INT32). The proper way to print a UINTN value with DEBUG is to
>> cast the value to UINT64, and print that with %Lu (or %Lx).
> 
> Refer to "cast the value to UINT64".
> 
> UINTN is either UINT32 or UINT64. There is no format specifier that's
> dedicated specifically to UINTN. You can't use fixed %u with UINTN
> because that will be wrong on 64-bit platforms (%u takes UINT32 but
> UINTN will be UINT64), and you can't use fixed %Lu with UINTN because
> that will be wrong on 32-bit platforms (%Lu takes UINT64 but UINTN will
> be UINT32). The proper way is to (1) cast the UINTN to UINT64 first
> (which will be a no-op on 64-bit platforms, and it will widen UINT32 to
> UINT64 on 32-bit platforms, without changing the value), and then (2)
> print *that* (the now certainly UINT64 value) with %Lu.
> 
>   DEBUG ((
>     DEBUG_ERROR,
>     "Failed to allocate %Lu pages.\n",
>     (UINT64)BufferPages
>     ));
> 
> (
> 
> Here's an idea:
> 
>> diff --git a/MdePkg/Include/Library/PrintLib.h b/MdePkg/Include/Library/PrintLib.h
>> index 8d523cac528d..bdacec9777f0 100644
>> --- a/MdePkg/Include/Library/PrintLib.h
>> +++ b/MdePkg/Include/Library/PrintLib.h
>> @@ -197,6 +197,17 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
>>  #define PREFIX_ZERO   0x20
>>  #define RADIX_HEX     0x80
>>
>> +#if defined (MDE_CPU_AARCH64) || defined (MDE_CPU_LOONGARCH64) || \
>> +    defined (MDE_CPU_RISCV64) || defined (MDE_CPU_X64)
>> +#define PRIuN "%Lu"
>> +#define PRIxN "%Lx"
>> +#elif defined (MDE_CPU_ARM) || defined (MDE_CPU_IA32)
>> +#define PRIuN "%Lu"
>> +#define PRIxN "%Lx"

aargh, how annoying. I'm in a rush, sorry. I over-edited this code and
forgot to remove the "L" from the latter two.

Laszlo

>> +#else
>> +#error Unknown CPU architecture.
>> +#endif
>> +
>>  /**
>>    Produces a Null-terminated Unicode string in an output buffer based on
>>    a Null-terminated Unicode format string and a VA_LIST argument list.
> 
> and then you could do
> 
>   DEBUG ((
>     DEBUG_ERROR,
>     "Failed to allocate " PRIuN " pages.\n",
>     BufferPages
>     ));
> 
> (Note the lack of a cast.)
> 
> Note: I do not cover MDE_CPU_EBC above, in "PrintLib.h". I don't know
> how EBC (EFI Byte Code) deals with 32-bit vs. 64-bit. The UEFI 2.10 spec
> says in "22.1.1 Processor Architecture Independence": "64-bit C source
> code" and "The interpreter handles 32 vs. 64 bit issues". Unfortunately,
> that doesn't seem to help: it does not help us decide the size of UINTN
> at compile time.
> 
> More precisely: if you check "MdePkg/Include/Ebc/ProcessorBind.h", it
> contains:
> 
>> ///
>> /// Signed value of native width.  (4 bytes on supported 32-bit processor instructions,
>> /// 8 bytes on supported 64-bit processor instructions)
>> /// "long" type scales to the processor native size with EBC compiler
>> ///
>> typedef long INTN;
>> ///
>> /// The unsigned value of native width.  (4 bytes on supported 32-bit processor instructions;
>> /// 8 bytes on supported 64-bit processor instructions)
>> /// "long" type scales to the processor native size with the EBC compiler.
>> ///
>> typedef unsigned long UINTN;
> 
> In other words, the size of UINTN *is* chosen at compile time, but the
> choice cannot be determined from MDE_CPU_EBC. And no other macro that
> "MdePkg/Include/Ebc/ProcessorBind.h" defines seems to be suitable for
> investigation with #if preprocessing directives.
> 
> Anyway: the explicit (UINT64) cast with the open-coded %Lu conversion
> specifier will work fine on EBC as well, so I suggest sticking with
> that.
> 
> )
> 
> Laszlo