[PATCH v7] linux: Add support for getrandom vDSO

[Florian Weimer]

* Adhemerval Zanella Netto:

> I am not sure which memory ordering fork() guarantee, however nptl-stack.c
> uses atomic_write_barrier() for every write on the global list:

That works, but it's from the legacy atomics.  I think the new name is
atomic_thread_fence_seq_cst (mirroring C11 atomics).

Thanks,
Florian