Re: [PATCH] x86/vdso: Error out if the vDSO isn't a valid DSO

From: Dmitry Safonov
Date: Tue Jul 19 2016 - 10:27:00 EST


2016-07-19 0:46 GMT+03:00 Andy Lutomirski <luto@xxxxxxxxxx>:
> Some distros has been playing with toolchain changes that can affect
> the type of ELF objects built. Occasionally, this goes wrong and
> the vDSO ends up not being a DSO at all. This causes the kernel to
> end up broken in a surprisingly subtle way -- glibc apparently
> silently ignores a vDSO that isn't a DSO, so everything works,
> albeit slowly, until users try a different libc implementation.
>
> Make the kernel build process a bit more robust: fail outright if
> the vDSO isn't ET_DYN or is missing its PT_DYNAMIC segment. I've
> never seen this in an unmodified kernel.
>
> See https://github.com/docker/docker/issues/23378

Heh, that's good, I've also saw the same kind of bug:
https://lists.openvz.org/pipermail/criu/2016-June/029153.html