kill tracehook_notify_death()
Kill tracehook_notify_death(), reimplement the logic in its caller,
exit_notify().
Also, change the exec_id's check to use thread_group_leader() instead
of task_detached(), this is more clear. This logic only applies to
the exiting leader, a sub-thread must never change its exit_signal.
Note: when the traced group leader exits the exit_signal-or-SIGCHLD
logic looks really strange:
- we notify the tracer even if !thread_group_empty() but
do_wait(WEXITED) can't work until all threads exit
- if the tracer is real_parent, it is not clear why can't
we use ->exit_signal event if !thread_group_empty()
-v2: do not try to fix the 2nd oddity to avoid the subtle behavior
change mixed with reorganization, suggested by Tejun.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index 34d135f..bb08e93 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -819,9 +819,7 @@
*/
static void exit_notify(struct task_struct *tsk, int group_dead)
{
- int signal;
bool autoreap;
- void *cookie;
/*
* This does two things:
@@ -852,16 +850,23 @@
* we have changed execution domain as these two values started
* the same after a fork.
*/
- if (tsk->exit_signal != SIGCHLD && !task_detached(tsk) &&
+ if (thread_group_leader(tsk) && tsk->exit_signal != SIGCHLD &&
(tsk->parent_exec_id != tsk->real_parent->self_exec_id ||
tsk->self_exec_id != tsk->parent_exec_id))
tsk->exit_signal = SIGCHLD;
- signal = tracehook_notify_death(tsk, &cookie, group_dead);
- if (signal >= 0)
- autoreap = do_notify_parent(tsk, signal);
- else
- autoreap = (signal == DEATH_REAP);
+ if (unlikely(tsk->ptrace)) {
+ int sig = thread_group_leader(tsk) &&
+ thread_group_empty(tsk) &&
+ !ptrace_reparented(tsk) ?
+ tsk->exit_signal : SIGCHLD;
+ autoreap = do_notify_parent(tsk, sig);
+ } else if (thread_group_leader(tsk)) {
+ autoreap = thread_group_empty(tsk) &&
+ do_notify_parent(tsk, tsk->exit_signal);
+ } else {
+ autoreap = true;
+ }
tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE;