diff options
| -rw-r--r-- | kernel/exit.c | 14 | ||||
| -rw-r--r-- | kernel/pid_namespace.c | 20 |
2 files changed, 33 insertions, 1 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index c0277d3f1aaa..a85efd2348bd 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -64,7 +64,6 @@ static void exit_mm(struct task_struct * tsk); static void __unhash_process(struct task_struct *p, bool group_dead) { nr_threads--; - detach_pid(p, PIDTYPE_PID); if (group_dead) { detach_pid(p, PIDTYPE_PGID); detach_pid(p, PIDTYPE_SID); @@ -72,7 +71,20 @@ static void __unhash_process(struct task_struct *p, bool group_dead) list_del_rcu(&p->tasks); list_del_init(&p->sibling); __this_cpu_dec(process_counts); + /* + * If we are the last child process in a pid namespace to be + * reaped, notify the reaper sleeping zap_pid_ns_processes(). + */ + if (IS_ENABLED(CONFIG_PID_NS)) { + struct task_struct *parent = p->real_parent; + + if ((task_active_pid_ns(p)->child_reaper == parent) && + list_empty(&parent->children) && + (parent->flags & PF_EXITING)) + wake_up_process(parent); + } } + detach_pid(p, PIDTYPE_PID); list_del_rcu(&p->thread_group); } diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 16b20e38c4a1..b3c7fd554250 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -184,11 +184,31 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) } read_unlock(&tasklist_lock); + /* Firstly reap the EXIT_ZOMBIE children we may have. */ do { clear_thread_flag(TIF_SIGPENDING); rc = sys_wait4(-1, NULL, __WALL, NULL); } while (rc != -ECHILD); + /* + * sys_wait4() above can't reap the TASK_DEAD children. + * Make sure they all go away, see __unhash_process(). + */ + for (;;) { + bool need_wait = false; + + read_lock(&tasklist_lock); + if (!list_empty(¤t->children)) { + __set_current_state(TASK_UNINTERRUPTIBLE); + need_wait = true; + } + read_unlock(&tasklist_lock); + + if (!need_wait) + break; + schedule(); + } + if (pid_ns->reboot) current->signal->group_exit_code = pid_ns->reboot; |