Re: aarch64-pe can't fill 16 bytes in section .text

[Zac Walker <zac.walker@linaro.org>]

Thanks Alan,

Do you think my SUB_SEGMENT_ALIGN patch is still needed. I didn't merge it yet because I wanted to do more testing with your fix.

Zac

---
  gas/config/tc-aarch64.h | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/gas/config/tc-aarch64.h b/gas/config/tc-aarch64.h
index 2d514ff610..0ea73021f2 100644
--- a/gas/config/tc-aarch64.h
+++ b/gas/config/tc-aarch64.h
@@ -191,7 +191,10 @@ struct aarch64_frag_type
        goto LABEL;								\
      }

+/* COFF sub section alignment calculated using the write.c implementation.  */
+#ifndef OBJ_COFF
  #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0
+#endif

  #define DWARF2_LINE_MIN_INSN_LENGTH 	4

-- 
2.25.1



On 11/15/22 22:53, Alan Modra wrote:
> I'm going to fix the underlying coff_frob_section problem too.
> Without commit b66e671854, this:
>   .p2align 4
>   nop
>   .p2align 3
>   nop
> results in an error when coff_frob_section attempts to pad out the
> section to a 16-byte boundary.  Due to miscalculating the pad pattern
> repeat count, write.c:write_contents attempts to shove 16 bytes of
> padding into the remaining 4 bytes of the .text section.
> 
> 	* config/obj-coff.c (coff_frob_section): Correct fill count.
> 	Don't pad after errors.
> 
> diff --git a/gas/config/obj-coff.c b/gas/config/obj-coff.c
> index 98c39e43907..9be697fb62e 100644
> --- a/gas/config/obj-coff.c
> +++ b/gas/config/obj-coff.c
> @@ -1725,7 +1725,8 @@ coff_frob_section (segT sec)
>     bfd_vma align_power = (bfd_vma) sec->alignment_power + OCTETS_PER_BYTE_POWER;
>     bfd_vma mask = ((bfd_vma) 1 << align_power) - 1;
>   
> -  if (size & mask)
> +  if (!do_not_pad_sections_to_alignment
> +      && (size & mask) != 0)
>       {
>         bfd_vma new_size;
>         fragS *last;
> @@ -1740,7 +1741,10 @@ coff_frob_section (segT sec)
>         while (fragp->fr_next != last)
>   	fragp = fragp->fr_next;
>         last->fr_address = size;
> -      fragp->fr_offset += new_size - size;
> +      if ((new_size - size) % fragp->fr_var == 0)
> +	fragp->fr_offset += (new_size - size) / fragp->fr_var;
> +      else
> +	abort ();
>       }
>   #endif
>   
>