Re: [PATCH 3/3] pids: Make it possible to clone tasks with given pids

[Oleg Nesterov <oleg@redhat.com>]

My previous objection was wrong, I should try to find something else ;)

On 11/17, Pavel Emelyanov wrote:
>
> +static int set_pidmap(struct pid_namespace *pid_ns, int pid)
> +{
> +	int offset;
> +	struct pidmap *map;
> +
> +	/*
> +	 * When creating a new pid namespace we must make its init
> +	 * have pid == 1 in it.
> +	 */
> +	if (pid_ns->child_reaper == NULL)
> +		return 0;
> +
> +	/*
> +	 * Don't allow to create a task with a pid which has recently
> +	 * belonged to some other (dead already) task. Only init (of
> +	 * a freshly created namespace) and his clones can do this.
> +	 */
> +	if (pid_ns->last_pid != 1)
> +		return -EPERM;
> +
> +	map = &pid_ns->pidmap[pid/BITS_PER_PAGE];

probably we should check that map < PIDMAP_ENTRIES ?

Oleg.