[PATCH] x86: Don't remove empty x86 properties

[H.J. Lu]

On Wed, Dec 5, 2018 at 3:07 PM Cary Coutant <ccoutant@gmail.com> wrote:
>
> > > The way you've defined the values, ISA_1_USED uses the OR_AND rule,
> > > which implements the behavior you want for ISA_1_NEEDED. ISA_1_NEEDED
> > > uses the OR rule, which implements the behavior you want for
> > > ISA_1_USED. Likewise for FEATURE_2_USED and FEATURE_2_NEEDED.
> >
> > I committed a typo fix.  Now it reads
> >
> > GNU_PROPERTY_X86_FEATURE_2_NEEDED The x86 processor features in-
> > dicated by the corresponding bits are needed in program and they must be
> > supported by the hardware. Loader may refuse to load the program whose
> > GNU_PROPERTY_X86_FEATURE_2_NEEDED features aren’t supported by the
> > hardware.
> > GNU_PROPERTY_X86_ISA_1_NEEDED The x86 instruction sets indicated
> > by the corresponding bits are needed in program and they must be sup-
> > ported by the hardware.
> > Loader may refuse to load the program whose
> > GNU_PROPERTY_X86_ISA_1_NEEDED ISAs aren’t supported by the hardware.
>
> That doesn't fix a thing. Here's the fix you need:
>
>    Table 5.3: Program Property Types
>    Name                               Value
>    GNU_PROPERTY_X86_FEATURE_1_AND     GNU_PROPERTY_X86_UINT32_AND_LO + 0
> -   GNU_PROPERTY_X86_FEATURE_2_USED    GNU_PROPERTY_X86_UINT32_OR_AND_LO + 1
> +  GNU_PROPERTY_X86_FEATURE_2_USED    GNU_PROPERTY_X86_UINT32_OR_LO + 1
> -   GNU_PROPERTY_X86_FEATURE_2_NEEDED  GNU_PROPERTY_X86_UINT32_OR_LO + 1
> +  GNU_PROPERTY_X86_FEATURE_2_NEEDED  GNU_PROPERTY_X86_UINT32_OR_AND_LO + 1
> -   GNU_PROPERTY_X86_ISA_1_USED        GNU_PROPERTY_X86_UINT32_OR_AND_LO + 0
> +  GNU_PROPERTY_X86_ISA_1_USED        GNU_PROPERTY_X86_UINT32_OR_LO + 0
> -   GNU_PROPERTY_X86_ISA_1_NEEDED      GNU_PROPERTY_X86_UINT32_OR_LO + 0
> +  GNU_PROPERTY_X86_ISA_1_NEEDED      GNU_PROPERTY_X86_UINT32_OR_AND_LO + 0

That is not right.  It should be

1. USED follows OR_AND.
2.  NEEDED follows OR,

Can you point me where x86-64 psABI says otherwise?

> And this:
>
> --- a/bfd/elfxx-x86.c
> +++ b/bfd/elfxx-x86.c
> @@ -2408,7 +2408,7 @@ _bfd_x86_elf_merge_gnu_properties (struct
> bfd_link_info *info,
>    bfd_boolean updated = FALSE;
>    unsigned int pr_type = aprop != NULL ? aprop->pr_type : bprop->pr_type;
>
> -  if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
> +  if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
>        || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_AND_LO
>           && pr_type <= GNU_PROPERTY_X86_UINT32_OR_AND_HI))
>      {
> @@ -2426,7 +2426,7 @@ _bfd_x86_elf_merge_gnu_properties (struct
> bfd_link_info *info,
>         }
>        goto or_property;
>      }
> -  else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_NEEDED
> +  else if (pr_type == GNU_PROPERTY_X86_COMPAT_ISA_1_USED
>            || (pr_type >= GNU_PROPERTY_X86_UINT32_OR_LO
>                && pr_type <= GNU_PROPERTY_X86_UINT32_OR_HI))
>      {
>
> -cary



-- 
H.J.