summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorOleg Nesterov <oleg@redhat.com>2011-06-23 19:06:50 +0200
committerOleg Nesterov <oleg@redhat.com>2011-06-27 20:30:08 +0200
commit45cdf5cc0703c537194588c63d53bad1f2539d36 (patch)
tree579573d2cbe054d767a9f6b575b88836586fb7ce
parent53c8f9f199b239668e6b1a907735ee323a0d1ccd (diff)
downloadop-kernel-dev-45cdf5cc0703c537194588c63d53bad1f2539d36.zip
op-kernel-dev-45cdf5cc0703c537194588c63d53bad1f2539d36.tar.gz
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>
-rw-r--r--include/linux/tracehook.h34
-rw-r--r--kernel/exit.c21
2 files changed, 13 insertions, 42 deletions
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h
index 7a1bd12..a71a292 100644
--- a/include/linux/tracehook.h
+++ b/include/linux/tracehook.h
@@ -152,40 +152,6 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info,
ptrace_notify(SIGTRAP);
}
-#define DEATH_REAP -1
-#define DEATH_DELAYED_GROUP_LEADER -2
-
-/**
- * tracehook_notify_death - task is dead, ready to notify parent
- * @task: @current task now exiting
- * @death_cookie: value to pass to tracehook_report_death()
- * @group_dead: nonzero if this was the last thread in the group to die
- *
- * A return value >= 0 means call do_notify_parent() with that signal
- * number. Negative return value can be %DEATH_REAP to self-reap right
- * now, or %DEATH_DELAYED_GROUP_LEADER to a zombie without notifying our
- * parent. Note that a return value of 0 means a do_notify_parent() call
- * that sends no signal, but still wakes up a parent blocked in wait*().
- *
- * Called with write_lock_irq(&tasklist_lock) held.
- */
-static inline int tracehook_notify_death(struct task_struct *task,
- void **death_cookie, int group_dead)
-{
- if (task_detached(task))
- return task->ptrace ? SIGCHLD : DEATH_REAP;
-
- /*
- * If something other than our normal parent is ptracing us, then
- * send it a SIGCHLD instead of honoring exit_signal. exit_signal
- * only has special meaning to our real parent.
- */
- if (thread_group_empty(task) && !ptrace_reparented(task))
- return task->exit_signal;
-
- return task->ptrace ? SIGCHLD : DEATH_DELAYED_GROUP_LEADER;
-}
-
#ifdef TIF_NOTIFY_RESUME
/**
* set_notify_resume - cause tracehook_notify_resume() to be called
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 forget_original_parent(struct task_struct *father)
*/
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 @@ static void exit_notify(struct task_struct *tsk, int group_dead)
* 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;
OpenPOWER on IntegriCloud