Re: [RFC 0/2] __vdso_findsym

Rich Felker
2014-06-15T14:35:10Z

On Sun, Jun 15, 2014 at 04:25:37PM +0200, Mikael Pettersson wrote:
> Andy Lutomirski writes:
> > The idea is to add AT_VDSO_FINDSYM pointing at __vdso_findsym. This
> > implements __vdso_findsym.
> >
> > This would make it easier for runtimes that don't otherwise implement
> > ELF loaders to use the vdso.
> >
> > Thoughts?
>
> I'm opposed to this based on the principle that the kernel should NOT
> be a dumping ground for random code that user-space can and should
> implement for itself. As long as the vdso is correctly formatted ELF,
> then parsing it is easy, and the kernel should not care at all if or
> how user-space accesses it.

Arguably, it was a mistake for the kernel to expose a virtual ELF to
begin with, and it should just have exposed a "lookup function by
name" operation to begin with. Yes this can be done in userspace, but
I see it more as a matter of "fixing a broken API design".

Rich