Re: Proper interface for finding the ELF auxilary vector

[Martin Husemann <martin%duskware.de@localhost>]

On Wed, Feb 15, 2012 at 12:07:08AM +0100, Joerg Sonnenberger wrote:
> Hi all,
> attached patch adds a new function _dlauxinfo() to obtain a pointer to
> the ELF auxilary vector.

This looks good (though I don't know if there are alternative solutions).

> The function returns void * to allow changing the vector.

        void *_dlauxinfo(void)

Do we want to consider backward compatibility issues here, or just mandate
that no newer libc may ever be installed without a newer ld.elf_so?
Is it possible for __init_libc to check for the presence of the symbol
before calling it without a serious startup slowdonw?

I wonder if we should pass in a version number (or size value) to identify
the requested version - we surely want old libc to work with newer ld.elf_so.
A simple

        void *_dlauxinfo(unsigned version)

would do.

Or we could restrict ourselfs to only upward compatible changes.

Martin