Commit 9bc86925 authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'bpf-task_group_seq_get_next-misc-cleanups' 

Oleg Nesterov says:

====================
bpf: task_group_seq_get_next: misc cleanups

Yonghong,

I am resending 1-5 of 6 as you suggested with your acks included.

The next (final) patch will change this code to use __next_thread when

	https://lore.kernel.org/all/20230824143142.GA31222@redhat.com/

is merged.

Oleg.
====================

Link: https://lore.kernel.org/r/20230905154612.GA24872@redhat.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents 35897c3c 780aa8df

kernel/bpf/task_iter.c

+10 −30
Original line number Diff line number Diff line
@@ -35,16 +35,13 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm 
						   u32 *tid,

						   bool skip_if_dup_files)

{

	struct task_struct *task, *next_task;

	struct task_struct *task;

	struct pid *pid;

	u32 saved_tid;

	u32 next_tid;



	if (!*tid) {

		/* The first time, the iterator calls this function. */

		pid = find_pid_ns(common->pid, common->ns);

		if (!pid)

			return NULL;



		task = get_pid_task(pid, PIDTYPE_TGID);

		if (!task)

			return NULL;
@@ -66,44 +63,27 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm 
		return task;

	}



	pid = find_pid_ns(common->pid_visiting, common->ns);

	if (!pid)

		return NULL;



	task = get_pid_task(pid, PIDTYPE_PID);

	task = find_task_by_pid_ns(common->pid_visiting, common->ns);

	if (!task)

		return NULL;



retry:

	if (!pid_alive(task)) {

		put_task_struct(task);

		return NULL;

	}



	next_task = next_thread(task);

	put_task_struct(task);

	if (!next_task)

		return NULL;

	task = next_thread(task);



	saved_tid = *tid;

	*tid = __task_pid_nr_ns(next_task, PIDTYPE_PID, common->ns);

	if (!*tid || *tid == common->pid) {

	next_tid = __task_pid_nr_ns(task, PIDTYPE_PID, common->ns);

	if (!next_tid || next_tid == common->pid) {

		/* Run out of tasks of a process.  The tasks of a

		 * thread_group are linked as circular linked list.

		 */

		*tid = saved_tid;

		return NULL;

	}



	get_task_struct(next_task);

	common->pid_visiting = *tid;



	if (skip_if_dup_files && task->files == task->group_leader->files) {

		task = next_task;

	if (skip_if_dup_files && task->files == task->group_leader->files)

		goto retry;

	}



	return next_task;

	*tid = common->pid_visiting = next_tid;

	get_task_struct(task);

	return task;

}



static struct task_struct *task_seq_get_next(struct bpf_iter_seq_task_common *common,