Re: is there plan to support 'linker namespace' in glib?

[Florian Weimer <fweimer at redhat dot com>]

* zhuao:

> I notice that android bionic support 'linker namespace': https://source.android.com/devices/architecture/vndk/linker-namespace
> it provides additional isolation among software components.
> it may also benefit some usage: 
>  - isolation prebuilt binaries with different toolchain (versioned glibc)
>  - it may also give us opportunity to use android binary (HAL) with glibc, by isolating glib and bionic world in different namespace
>
>
> do you think the above approach is possible?
>  if yes, is it possible to add such feature to glibc?

There have been many discussions over the year.  The requirements are
quite diverse: some people want group support as in the Solaris linker.
Others want dlmopen with a shared malloc (and perhaps shared other
libraries; our implementation currently shares only the dynamic linker
and nothing else).  Again others want to load the same library multiple
times, disregarding its soname.  Then there is a desire to have some
sort of firewall between different linker namespaces, as a general
framework, so that you can load the same soname multiple times, and
still achieving consistent execution.

I think that anything that is fairly general and actually works is still
a major research effort, in addition to the work that would be needed to
implement it in the current dynamic linker.  While a lot of research has
been done on modules and how to compose them in the 80s, a lot of that
knowledge seems to have been lost or is simply not available to people
working on C/C++ implementations today.

Thanks,
Florian