exit_notify() does exit_task_namespaces() after
forget_original_parent(). This was needed to ensure that ->nsproxy
can't be cleared prematurely, an exiting child we are going to
reparent can do do_notify_parent() and use the parent's (ours) pid_ns.
However, after 32084504 "pidns: use task_active_pid_ns in
do_notify_parent" ->nsproxy != NULL is no longer needed, we rely
on task_active_pid_ns().
Move exit_task_namespaces() from exit_notify() to do_exit(), after
exit_fs() and before exit_task_work().
This solves the problem reported by Andrey, free_ipc_ns()->shm_destroy()
does fput() which needs task_work_add(). And this allows us do simplify
exit_notify(), we can avoid unlock/lock(tasklist) and we can change
->exit_state instead of PF_EXITING in forget_original_parent().
Reported-by: Andrey Vagin <ava...@openvz.org>
Signed-off-by: Oleg Nesterov <o...@redhat.com>
--- x/kernel/exit.c
+++ x/kernel/exit.c
@@ -649,7 +649,6 @@ static void exit_notify(struct task_stru
* jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2)
*/
forget_original_parent(tsk);
- exit_task_namespaces(tsk);
write_lock_irq(&tasklist_lock);
if (group_dead)
@@ -795,6 +794,7 @@ void do_exit(long code)
exit_shm(tsk);
exit_files(tsk);
exit_fs(tsk);
+ exit_task_namespaces(tsk);
exit_task_work(tsk);
check_stack_usage();
exit_thread();
--
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