Re: [PATCH 2/2] procfs/tasks: add a simple per-task procfs hidepid= field

[Jann Horn]

On Thu, Nov 03, 2016 at 10:12:55AM -0600, Kees Cook wrote:
> On Thu, Nov 3, 2016 at 9:30 AM, Lafcadio Wluiki <wluikil@xxxxxxxxx> wrote:
> > (Third, rebased submission, since first two submissions yielded no replies.)
> >
> > This adds a new per-task hidepid= flag that is honored by procfs when
> > presenting /proc to the user, in addition to the existing hidepid= mount
> > option. So far, hidepid= was exclusively a per-pidns setting. Locking
> > down a set of processes so that they cannot see other user's processes
> > without affecting the rest of the system thus currently requires
> > creation of a private PID namespace, with all the complexity it brings,
> > including maintaining a stub init process as PID 1 and losing the
> > ability to see processes of the same user on the rest of the system.
[...]
> Since this adds a new prctl interface, it's best to Cc linux-arch
> (which I added now).

Please also CC linux-api for the next iteration, since this is a new
userspace-facing API.