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

[Aleksandar Ristovski <aristovski at qnx dot com>]

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