[PATCH v2 1/2] Disable SFrame support by default

[Florian Weimer]

* Adhemerval Zanella:

> diff --git a/elf/dl-find_object.h b/elf/dl-find_object.h
> index 9aa2439eaa..6a50b4becf 100644
> --- a/elf/dl-find_object.h
> +++ b/elf/dl-find_object.h
> @@ -43,7 +43,9 @@ struct dl_find_object_internal
>  #if DLFO_STRUCT_HAS_EH_COUNT
>    int eh_count;
>  #endif
> +#if ENABLE_SFRAME
>    void *sframe;
> +#endif
>  };
>  
>  /* Create a copy of *SOURCE in *COPY using relaxed MO loads and
> @@ -68,8 +70,10 @@ _dl_find_object_internal_copy (const struct dl_find_object_internal *source,
>    atomic_store_relaxed (&copy->eh_count,
>                          atomic_load_relaxed (&source->eh_count));
>  #endif
> +#if ENABLE_SFRAME
>    atomic_store_relaxed (&copy->sframe,
>                          atomic_load_relaxed (&source->sframe));
> +#endif
>  }
>  
>  static inline void
> @@ -86,10 +90,12 @@ _dl_find_object_to_external (struct dl_find_object_internal *internal,
>  # if DLFO_STRUCT_HAS_EH_COUNT
>    external->dlfo_eh_count = internal->eh_count;
>  # endif
> +# if ENABLE_SFRAME
>    external->dlfo_sframe = internal->sframe;
>    if (internal->sframe != NULL)
>      external->dlfo_flags = DLFO_FLAG_SFRAME;
>    else
> +# endif
>      external->dlfo_flags = 0;
>  }
>  
> @@ -112,7 +118,9 @@ _dl_find_object_from_map (struct link_map *l,
>  
>    /* Initialize object's exception handling segment and SFrame segment
>       data.  */
> +#if ENABLE_SFRAME
>    atomic_store_relaxed (&result->sframe, NULL);
> +#endif
>    atomic_store_relaxed (&result->eh_frame, NULL);
>  #if DLFO_STRUCT_HAS_EH_COUNT
>    atomic_store_relaxed (&result->eh_count, 0);
> @@ -132,11 +140,13 @@ _dl_find_object_from_map (struct link_map *l,
>            read_seg |= 1;
>            break;
>  
> +#if ENABLE_SFRAME
>          case PT_GNU_SFRAME:
>            atomic_store_relaxed (&result->sframe,
>                                  (void *) (ph->p_vaddr + l->l_addr));
>            read_seg |= 2;
>            /* Fall through.  */
> +#endif
>          default:
>            break;
>          }

I think thos changes are not necessary.  We can support locating SFrame
data with _dl_find_object even if glibc itself does not contain any.

Thanks,
Florian