On Wed, May 29, 2019 at 03:24:15PM -0700, Andrei Vagin wrote:

On Wed, May 29, 2019 at 05:22:36PM +0200, Christian Brauner wrote:

quoted

This adds the clone3 system call.

As mentioned several times already (cf. [7], [8]) here's the promised
patchset for clone3().

We recently merged the CLONE_PIDFD patchset (cf. [1]). It took the last
free flag from clone().

Independent of the CLONE_PIDFD patchset a time namespace has been discussed
at Linux Plumber Conference last year and has been sent out and reviewed
(cf. [5]). It is expected that it will go upstream in the not too distant
future. However, it relies on the addition of the CLONE_NEWTIME flag to
clone(). The only other good candidate - CLONE_DETACHED - is currently not
recyclable as we have identified at least two large or widely used
codebases that currently pass this flag (cf. [2], [3], and [4]). Given that
CLONE_PIDFD grabbed the last clone() flag the time namespace is effectively
blocked. clone3() has the advantage that it will unblock this patchset
again.

Hi Christian,

Hi Andrei,

(Traveling until Monday, so sorry for delayed responses.)

Thank you for thinking about time namespaces. I looked at this patch
quickly and I would suggest to move a termination signal out of flags. I
think we can add a separate field (exit_signal) into clone_args. Does it
make sense? For me, exit_signal in flags always looked weird...

Yup, that does sound good to me.

I will look at this patch more detailed later this week. Thanks.

Excellent!

Christian