[PATCH] simply fix first_tgid

 * In the case of a seek we start with &init_task and walk nr

 * threads past it.

 */

static struct task_struct *first_tgid(int tgid, int nr)

static struct task_struct *first_tgid(int tgid, unsigned int nr)

{

	struct task_struct *pos = NULL;

	struct task_struct *pos;

	rcu_read_lock();

	if (tgid && nr) {

		pos = find_task_by_pid(tgid);

		if (pos && !thread_group_leader(pos))

			pos = NULL;

		if (pos)

			nr = 0;

		if (pos && thread_group_leader(pos))

			goto found;

	}

	/* If nr exceeds the number of processes get out quickly */

	pos = NULL;

	if (nr && nr >= nr_processes())

		goto done;

	/* If we haven't found our starting place yet start with

	 * the init_task and walk nr tasks forward.

	 */

	if (!pos && (nr >= 0))

		pos = next_task(&init_task);

	for (; pos && pid_alive(pos); pos = next_task(pos)) {

		if (--nr > 0)

			continue;

		get_task_struct(pos);

	for (pos = next_task(&init_task); nr > 0; --nr) {

		pos = next_task(pos);

		if (pos == &init_task) {

			pos = NULL;

			goto done;

		}

	pos = NULL;

	}

found:

	get_task_struct(pos);

done:

	rcu_read_unlock();

	return pos;