Re: Dynamic Linker: Exposing static symbols at runtime

[Florian Weimer <fweimer@redhat.com>]

* Harley Paterson via Libc-alpha:

> I'm doing some research on dynamic software updating recently. I've
> found it would be very helpful to expose static symbols to running
> program, much like `dlopen`, `dlsym`, and friends expose dynamic
> symbols to running programs via the `dlfcn.h` header.
>
> Is anyone able to provide insight into what work is required to get
> the `ld-linux.so` to read the static symbol stable, and expose symbols
> to processes via an API?

In general, the static symbol table is not mapped into memory because it
is not located in an allocated section.  So the dynamic loader cannot
provide this data any more easily than a separate library could: it
would have to load it from disk as a first step, too.  This suggests to
me that glibc integration is not really needed.

Thanks,
Florian
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