PIDFD_THREAD
BUILD_BUG_ON(PIDFD_STALE == PIDFD_THREAD);
pidfd_file->f_flags |= (flags & PIDFD_THREAD);
if (!(flags & PIDFD_THREAD) && !pid_has_task(pid, PIDTYPE_TGID))
int flags = (clone_flags & CLONE_THREAD) ? PIDFD_THREAD : 0;
if (flags & ~(PIDFD_NONBLOCK | PIDFD_THREAD))
if (fd_file(f)->f_flags & PIDFD_THREAD)
#ifndef PIDFD_THREAD
pidfd_leader_thread = sys_pidfd_open(pid_leader, PIDFD_THREAD);
pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);
pidfd_leader_thread = sys_pidfd_open(pid_leader, PIDFD_THREAD);
pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);
pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);
pidfd_leader_thread = sys_pidfd_open(pid_leader, PIDFD_THREAD);