[PATCH] ld: Clear SEC_ALLOC for NOLOAD notes sections

[Jan Beulich]

On 14.03.2025 02:02, H.J. Lu wrote:
> On Thu, Mar 13, 2025 at 5:40 PM Alan Modra <amodra@gmail.com> wrote:
>>
>> On Thu, Mar 13, 2025 at 12:14:50PM -0700, H.J. Lu wrote:
>>> If a note section is marked as NOLOAD, clear the SEC_ALLOC so that it
>>> won't be treated as an SHF_ALLOC section, like a .bss section.
>>
>> Perhaps we should instead make NOLOAD consistent over all targets?
>> That might not be possible, at least I thought so at the time I wrote
>> that "Unfortunately.." comment, but it is nasty that NOLOAD behaves
>> differently for ELF.
> 
> Can we make the exception only for .bss sections, like
> 
>      if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour
>           && startswith (section->name, ".bss"))
>         flags &= ~SEC_HAS_CONTENTS;
>       else
>         flags &= ~SEC_ALLOC;

May I ask that we strive to avoid going from (just) section name for at
least ELF, wherever possible? Something BSS-like may have effectively any
section name; what matters is the NOBITS type. Same for note sections,
where all that matters (or should I say "should matter") is that they're
SHT_NOTE.

As to the original patch - I guess alongside whatever final change there
is going to be, the different behavior of NOLOAD then needs spelling out
in the doc. That would be at least one predictable place where people can
go look when being surprised by inconsistent behavior.

Jan