Re: [PATCH v10 1/2] /proc/PID/status: show all sets of pid according to ns

From: Andrew Morton
Date: Mon Feb 23 2015 - 16:00:18 EST


On Fri, 6 Feb 2015 18:45:49 +0800 Chen Hanxiao <chenhanxiao@xxxxxxxxxxxxxx> wrote:

> If some issues occurred inside a container guest, host user
> could not know which process is in trouble just by guest pid:
> the users of container guest only knew the pid inside containers.
> This will bring obstacle for trouble shooting.
>
> This patch adds four fields: NStgid, NSpid, NSpgid and NSsid:
> a) In init_pid_ns, nothing changed;
>
> b) In one pidns, will tell the pid inside containers:
> NStgid: 21776 5 1
> NSpid: 21776 5 1
> NSpgid: 21776 5 1
> NSsid: 21729 1 0
> ** Process id is 21776 in level 0, 5 in level 1, 1 in level 2.
>
> c) If pidns is nested, it depends on which pidns are you in.
> NStgid: 5 1
> NSpid: 5 1
> NSpgid: 5 1
> NSsid: 1 0
> ** Views from level 1
>
> ...
>
> --- a/fs/proc/array.c
> +++ b/fs/proc/array.c
> @@ -208,6 +208,22 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
> from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
> put_cred(cred);
>
> + seq_puts(m, "\nNStgid:");
> + for (g = ns->level; g <= pid->level; g++)
> + seq_printf(m, "\t%d",
> + task_tgid_nr_ns(p, pid->numbers[g].ns));
> + seq_puts(m, "\nNSpid:");
> + for (g = ns->level; g <= pid->level; g++)
> + seq_printf(m, "\t%d",
> + task_pid_nr_ns(p, pid->numbers[g].ns));
> + seq_puts(m, "\nNSpgid:");
> + for (g = ns->level; g <= pid->level; g++)
> + seq_printf(m, "\t%d",
> + task_pgrp_nr_ns(p, pid->numbers[g].ns));
> + seq_puts(m, "\nNSsid:");
> + for (g = ns->level; g <= pid->level; g++)
> + seq_printf(m, "\t%d",
> + task_session_nr_ns(p, pid->numbers[g].ns));
> seq_putc(m, '\n');
> }

Is there any point in including this code if CONFIG_USER_NS=n?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/