Re: [RFC][PATCH v2 3/5] clone: Disallown CLONE_THREAD with a shared sighand_struct

From: Oleg Nesterov
Date: Wed Apr 05 2017 - 14:12:14 EST


On 04/05, Eric W. Biederman wrote:
>
> Oleg Nesterov <oleg@xxxxxxxxxx> writes:
>
> I agree that changing userspace semantics is something to be very
> careful with. But at least for purposes of discussion I think this is a
> good patch.

I agree that we need it with your approach,

but imo it would be much better to not depend on the subtle changes
like this. My 2/2 or your 1/5 are already bad enough.

> I can avoid this change but it requires moving sighand->siglock
> into signal_struct and introducing a new spinlock into sighand_struct
> to just guard the signal handlers.

Oh, this looks much, much worse to me.

Oleg.