Re: [PATCH] RISC-V: define elf_backend_dtrel_excludes_plt

wangjue <[email protected]>

> From: juewang <[email protected]>
>
> The RISC-V port never defined elf_backend_dtrel_excludes_plt, unlike
> x86-64, AArch64, arm, ppc, mips and s390.  As a result DT_RELASZ counted
> .rela.dyn + .rela.plt instead of just .rela.dyn.
>
> With an empty .rela.dyn this makes DT_RELA alias DT_JMPREL (DT_RELA ==
> DT_JMPREL, DT_RELASZ == DT_PLTRELSZ).  glibc accepts the aliased range,
> but tools that read the two ranges independently, such as llvm-bolt, then
> process .rela.plt twice.
>
> Define the macro so DT_RELASZ excludes .rela.plt, matching every other
> target.  When .rela.dyn is empty DT_RELA is now zeroed and the aliasing
> is gone.


Sounds reasonable, please commit.

Thanks
Nelson


>         * elfnn-riscv.c (elf_backend_dtrel_excludes_plt): Define.
>
> Signed-off-by: wangjue.wangjue <[email protected]>
> ---
>  bfd/elfnn-riscv.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
> index 1c1c3ea36c5..1ca23e4964a 100644
> --- a/bfd/elfnn-riscv.c
> +++ b/bfd/elfnn-riscv.c
> @@ -5587,6 +5587,7 @@ elfNN_riscv_merge_gnu_properties (struct
> bfd_link_info *info, bfd *abfd,
>  #define elf_backend_got_header_size            (ARCH_SIZE / 8)
>  #define elf_backend_want_dynrelro              1
>  #define elf_backend_rela_normal                        1
> +#define elf_backend_dtrel_excludes_plt 1
>  #define elf_backend_default_execstack          0
>
>  #undef  elf_backend_obj_attrs_vendor
> --
> 2.34.1
>
>