[patch] solib-svr4.c - allow reading linkmap info from core without executable

[Aleksandar Ristovski]

Is this ok to commit?

Aleksandar Ristovski wrote:
> Pedro Alves wrote:
>>>    if (info->debug_base == 0 && svr4_have_link_map_offsets ())
>>>      {
>>> -      if (exec_bfd != NULL
>>> +      if ((exec_bfd != NULL
>>>           && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
>>> +         || (core_bfd != NULL
>>> +             && bfd_get_flavour (core_bfd) == bfd_target_elf_flavour))
>>>         info->debug_base = elf_locate_base ();
>>>      }
>>
>> Are there live debugging cases (archs?, PIE?) (e.g., "target remote" 
>> without specifying an executable) where letting elf_locate_base
>> try to read the debug base from the target's auxv (scan_dyntag_auxv)
>> will work?  It would mean that removing the exec_bfd checks instead
>> of adding core_bfd checks, would still improve your case, while
>> letting other cases benefit as well.
>>
> 
> Yes, in theory it should work as long as target_ops in question know how 
> to read auxv (that is, as long as to_xfer_partial(ops, 
> TARGET_OBJECT_AUXV,...) knows how to do it.)
> 
> I had internally made this change:
> 
>     {
> -     if (exec_bfd != NULL
> +      if ((exec_bfd != NULL
>           && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
> +          || exec_bfd == NULL)
>         debug_base = elf_locate_base ();
>     }
>   return (debug_base);
> 
> 
> But wanted to be more conservative for FSF, since I do not quite 
> understand under which circumstances could we end up in solib-svr4, and 
> not have "bfd_target_elf_flavour".
> 
> 
> Thanks,
> 


-- 
Aleksandar Ristovski
QNX Software Systems