Re: [PATCH v4 5/6] IntelFrameworkModulePkg/Csm: Add code to bypass NULL pointer detection

[Laszlo Ersek <lersek@redhat.com>]

This patch breaks the GCC5 build:

On 10/09/17 16:17, Jian J Wang wrote:

> diff --git a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
> index 3d9a8b9649..f42c13cd89 100644
> --- a/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
> +++ b/IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c
> @@ -57,7 +57,11 @@ LegacyBiosInt86 (
>    IN  EFI_IA32_REGISTER_SET         *Regs
>    )
>  {
> -  UINT32  *VectorBase;
> +  UINT16                Segment;
> +  UINT16                Offset;
> +  LEGACY_BIOS_INSTANCE  *Private;
> +
> +  Private = LEGACY_BIOS_INSTANCE_FROM_THIS (This);
>  
>    Regs->X.Flags.Reserved1 = 1;
>    Regs->X.Flags.Reserved2 = 0;
> @@ -72,12 +76,15 @@ LegacyBiosInt86 (
>    // The base address of legacy interrupt vector table is 0.
>    // We use this base address to get the legacy interrupt handler.
>    //
> -  VectorBase              = 0;
> +  DisableNullDetection ();
> +  Segment               = (UINT16)(((UINT32 *)0)[BiosInt] >> 16);
> +  Offset                = (UINT16)((UINT32 *)0)[BiosInt];
> +  EnableNullDetection ();
>    
>    return InternalLegacyBiosFarCall (
>             This,
> -           (UINT16) ((VectorBase)[BiosInt] >> 16),
> -           (UINT16) (VectorBase)[BiosInt],
> +           Segment,
> +           Offset,
>             Regs,
>             &Regs->X.Flags,
>             sizeof (Regs->X.Flags)

IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c: In function 'LegacyBiosInt86':
IntelFrameworkModulePkg/Csm/LegacyBiosDxe/Thunk.c:62:26: error: variable 'Private' set but not used [-Werror=unused-but-set-variable]
   LEGACY_BIOS_INSTANCE  *Private;
                          ^~~~~~~
cc1: all warnings being treated as errors

Can you please send a patch?

Thanks!
Laszlo