IMAGE_SCN_LNK_NRELOC_OVFL

[Fangrui Song]

On 2021-07-30, Alan Modra via Binutils wrote:
>From microsoft docs: It is an error if IMAGE_SCN_LNK_NRELOC_OVFL is
>set and there are fewer than 0xffff relocations in the section.
>
>	* coffcode.h (coff_set_alignment_hook): Sanity check overflow
>	reloc count.
>
>diff --git a/bfd/coffcode.h b/bfd/coffcode.h
>index 9b8798c8631..d2076effb41 100644
>--- a/bfd/coffcode.h
>+++ b/bfd/coffcode.h
>@@ -1951,6 +1951,12 @@ coff_set_alignment_hook (bfd * abfd ATTRIBUTE_UNUSED,
>       coff_swap_reloc_in (abfd, &dst, &n);
>       if (bfd_seek (abfd, oldpos, 0) != 0)
> 	return;
>+      if (n.r_vaddr < 0xffff)

hdr->s_nreloc

>+	{
>+	  _bfd_error_handler (_("%pB: overflow reloc count too small"), abfd);
>+	  bfd_set_error (bfd_error_bad_value);
>+	  return;
>+	}
>       section->reloc_count = hdr->s_nreloc = n.r_vaddr - 1;
>       section->rel_filepos += relsz;
>     }
>
>-- 
>Alan Modra
>Australia Development Lab, IBM