OK, it seems that you are not going to take these preparatory cleanups ;) I'll resend along with the s/next_thread/__next_thread/ change. I was going to do the last change later, but this recent discussion https://lore.kernel.org/all/20230824143112.GA31208@xxxxxxxxxx/ makes me think we should do this right now. On 08/21, Oleg Nesterov wrote: > > 1. find_pid_ns() + get_pid_task() under rcu_read_lock() guarantees that we > can safely iterate the task->thread_group list. Even if this task exits > right after get_pid_task() (or goto retry) and pid_alive() returns 0. > > Kill the unnecessary pid_alive() check. > > 2. next_thread() simply can't return NULL, kill the bogus "if (!next_task)" > check. > > Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx> > --- > kernel/bpf/task_iter.c | 7 ------- > 1 file changed, 7 deletions(-) > > diff --git a/kernel/bpf/task_iter.c b/kernel/bpf/task_iter.c > index c4ab9d6cdbe9..4d1125108014 100644 > --- a/kernel/bpf/task_iter.c > +++ b/kernel/bpf/task_iter.c > @@ -75,15 +75,8 @@ static struct task_struct *task_group_seq_get_next(struct bpf_iter_seq_task_comm > 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; > > saved_tid = *tid; > *tid = __task_pid_nr_ns(next_task, PIDTYPE_PID, common->ns); > -- > 2.25.1.362.g51ebf55 > >
