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

[Adhemerval Zanella Netto]

On 23/07/25 04:27, Florian Weimer wrote:
> * 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.

Fair enough.