Re: [RFC PATCH 7/9] proc: add /proc//universe to show livepatch status

Josh Poimboeuf
2015-02-10T18:57:56Z

On Tue, Feb 10, 2015 at 07:47:12PM +0100, Jiri Slaby wrote:
> On 02/09/2015, 06:31 PM, Josh Poimboeuf wrote:
> > Expose the per-task klp_universe value so users can determine which
> > tasks are holding up completion of a patching operation.
> >
> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > ---
> > fs/proc/base.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/fs/proc/base.c b/fs/proc/base.c
> > index 3f3d7ae..b9fe6b5 100644
> > --- a/fs/proc/base.c
> > +++ b/fs/proc/base.c
> > @@ -2528,6 +2528,14 @@ static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
> > return err;
> > }
> >
> > +#ifdef CONFIG_LIVEPATCH
> > +static int proc_pid_klp_universe(struct seq_file *m, struct pid_namespace *ns,
> > + struct pid *pid, struct task_struct *task)
> > +{
> > + return seq_printf(m, "%d\n", task->klp_universe);
> > +}
> > +#endif /* CONFIG_LIVEPATCH */
> > +
> > /*
> > * Thread groups
> > */
> > @@ -2628,6 +2636,9 @@ static const struct pid_entry tgid_base_stuff[] = {
> > #ifdef CONFIG_CHECKPOINT_RESTORE
> > REG("timers", S_IRUGO, proc_timers_operations),
> > #endif
> > +#ifdef CONFIG_LIVEPATCH
> > + ONE("universe", S_IRUGO, proc_pid_klp_universe),
>
> I am not sure if this can be UGO or if it should be USR only instead.
> Leaving for discussion, but I incline to use USR to avoid *any* info
> leakage.

That's fine. I can't think of any reason why a non-root user would need
to know the task's universe.

--
Josh