On 2019-05-16, Oleg Nesterov <oleg@redhat.com> wrote:
> On 05/16, Christian Brauner wrote:
> >
> > With the introduction of pidfds through CLONE_PIDFD it is possible to
> > created pidfds at process creation time.
> 
> Now I am wondering why do we need CLONE_PIDFD, you can just do
> 
> 	pid = fork();
> 	pidfd_open(pid);

While the race window would be exceptionally short, there is the
possibility that the child will die and their pid will be recycled
before you do pidfd_open(). CLONE_PIDFD removes the race completely.

-- 
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>