Re: [PATCH v2 2/2] Extend struct r_debug to support multiple namespaces

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Aug 17, 2021 at 10:57 AM Daniel Walker <danielwa@cisco.com> wrote:
>
> On Mon, Aug 16, 2021 at 06:06:29PM -0700, H.J. Lu wrote:
> > Glibc does not provide an interface for debugger to access libraries
> > loaded in multiple namespaces via dlmopen.
> >
> > The current rtld-debugger interface is described in the file:
> >
> > elf/rtld-debugger-interface.txt
> >
> > under the "Standard debugger interface" heading.  This interface only
> > provides access to the first link-map (LM_ID_BASE).
> >
> > Based on the patch from Conan C Huang <conhuang@cisco.com>:
> >
> > https://sourceware.org/pipermail/libc-alpha/2020-June/115448.html
> >
> > 1. Bump r_version to 2.  This triggers the GDB bug:
> >
> > https://sourceware.org/bugzilla/show_bug.cgi?id=28236
> >
> > 2. Add struct r_debug_extended to extend struct r_debug into a linked-list,
> > where each element correlates to an unique namespace.
> > 3. Add a hidden symbol, _r_debug_extended, for struct r_debug_extended.
> > 4. Provide the compatibility symbol, _r_debug, with size of struct r_debug,
> > as an alise of _r_debug_extended, for programs which reference _r_debug.
>
>
> I've attached the GDB patch which was created at Cisco to support our version of
> this type of feature which is similar to what you've created. You might be able
> to make some small modifications to make it work for you.
>
> Daniel

I will give it a try.

Thanks.

-- 
H.J.