[PATCH] ld: Handle special ELF readonly output sections

[H.J. Lu]

On Wed, Apr 22, 2026 at 4:04 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 31.03.2026 20:15, H.J. Lu wrote:
> > @@ -3309,7 +3308,25 @@ _bfd_elf_get_sec_type_attr (bfd *abfd, asection *sec)
> >    if (spec == NULL)
> >      return NULL;
> >
> > -  return _bfd_elf_get_special_section (sec->name, spec, sec->use_rela_p);
> > +  return _bfd_elf_get_special_section (name, spec, use_rela_p);
> > +}
> > +
> > +const struct bfd_elf_special_section *
> > +_bfd_elf_get_sec_type_attr (bfd *abfd, asection *sec)
> > +{
> > +  return elf_get_special_section (abfd, sec->name, sec->use_rela_p);
> > +}
> > +
> > +bool
> > +_bfd_elf_is_special_readonly_section (bfd *abfd, const char *name)
> > +{
> > +  elf_backend_data *bed;
> > +  const struct bfd_elf_special_section *spec;
> > +  bed = get_elf_backend_data (abfd);
> > +  spec = elf_get_special_section (abfd, name, bed->default_use_rela_p);
> > +  if (spec == NULL)
> > +    return false;
> > +  return (spec->attr & SHF_WRITE) == 0;
> >  }
>
> This once again being solely name-based, ...
>
> > --- /dev/null
> > +++ b/ld/testsuite/ld-elf/flags2.ld
> > @@ -0,0 +1 @@
> > +SECTIONS { .rodata : ALIGN(4) { __crc_hello = .; LONG(0x05d25769); } }
>
> ... what's wrong with using the READONLY keyword here instead? If people
> create a section solely(?) from a linker script, can't they be expected
> to set the section's properties correctly? While it's against conventions,
> someone wanting a writable .rodata section ought to be able to get one.
> Much like they can from e.g. an assembly source file.
>
> Related, but not for this patch: Seeing get_os_init_flag(), why is
> typed_readonly_section not also resulting in SEC_READONLY there?
>
> > --- /dev/null
> > +++ b/ld/testsuite/ld-elf/flags2.s
> > @@ -0,0 +1,6 @@
> > +     .text
> > +     .globl  start
> > +     .type   start, %function
> > +start:
> > +     .byte 0
> > +     .section .note.GNU-stack, "", %progbits
>
> I think new testcases better wouldn't use %progbits for .note.GNU-stack
> anymore.
>
> Jan

READONLY works.  I withdrew this patch.

-- 
H.J.