Re: [PATCH] pidfd: add ioctl to retrieve pid info

[Luca Boccassi]

On Fri, 4 Oct 2024 at 20:30, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
>
> I wasn't CC'ed, so I didn't see the patch, but looking at Christian's
> reply ...
>
> On 10/04, Luca Boccassi wrote:
> > On Fri, 4 Oct 2024 at 10:29, Christian Brauner <brauner@xxxxxxxxxx> wrote:
> > >
> > > On Wed, Oct 02, 2024 at 03:24:33PM GMT, luca.boccassi@xxxxxxxxx wrote:
> > > > +             info.pid = pid_nr_ns(pid, task_active_pid_ns(task));
> > >
> > > I think this is wrong what this should return is the pid of the process
> > > as seen from the caller's pid namespace.
>
> Agreed,
>
> > Thanks for the review, I applied the rest of the comments in v2 (I
> > think at least), but for this one I can't tell, how should I do it?
>
> I guess Christian meant you should simply use
>
>                 info.pid = task_pid_vnr(task);
>
> task_pid_vnr(task) returns the task's pid in the caller's namespace.

Ah I see, I didn't realize there was a difference, sent v3 with the
suggested change just now, thanks.