Re: Official Linux system wrapper library?

From: Florian Weimer
Date: Wed Nov 14 2018 - 06:41:01 EST


* Dave Martin:

> Fair points, though this is rather what I meant by "sane essentials".
> Because there are strict limits on what can be done in the vDSO, it may
> be more bloat-resistant and more conservatively maintained.
>
> This might provide a way to push some dumb compatibility kludge code
> that receives little ongoing maintenance outside the privilege wall,
> whereas it has to sit in the kernel proper today.
>
> In theory we could opt to advertise new syscalls only via vDSO entry
> points, and not maintain __NR_xxx values for them (which may or may
> not upset ptrace users.) Anyway, I digress...

Is the vDSO available across all architectures? (I don't think we use
it on all architectures in glibc.)

If not, a vDSO-based approach would merely lead to even more variance
between architectures, which can't be a good thing.

Thanks,
Florian