Re: [PATCH v3 1/1] pidfd: implement PIDFD_THREAD flag for pidfd_open()

[Christian Brauner]

> @@ -2050,6 +2051,8 @@ static void pidfd_show_fdinfo(struct seq_file *m, struct file *f)
>  
>  	seq_put_decimal_ll(m, "Pid:\t", nr);
>  
> +	/* TODO: report PIDFD_THREAD */

So I think we don't need to do anything here. Since PIDFD_THREAD sets
O_EXCL in file->f_flags and in contrast to do_dentry_open() it isn't
dropped. So userspace can already detect PIDFD_NONBLOCK as O_NONBLOCK
and PIDFD_THREAD as O_EXCL.