if (same_thread_group(p->real_parent, father))
return;
- /* We don't want people slaying init. */
+ /* We don't want people slaying init. */
p->exit_signal = SIGCHLD;
/* If it has exited notify the new parent about this child's death. */
exit_shm(tsk);
exit_files(tsk);
exit_fs(tsk);
+ if (group_dead)
+ disassociate_ctty(1);
exit_task_namespaces(tsk);
exit_task_work(tsk);
- check_stack_usage();
exit_thread();
/*
cgroup_exit(tsk);
- if (group_dead)
- disassociate_ctty(1);
-
module_put(task_thread_info(tsk)->exec_domain->module);
- proc_exit_connector(tsk);
-
/*
* FIXME: do that only when needed, using sched_exit tracepoint
*/
flush_ptrace_hw_breakpoint(tsk);
exit_notify(tsk, group_dead);
+ proc_exit_connector(tsk);
#ifdef CONFIG_NUMA
task_lock(tsk);
mpol_put(tsk->mempolicy);
validate_creds_for_do_exit(tsk);
+ check_stack_usage();
preempt_disable();
if (tsk->nr_dirtied)
__this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied);
return wait_noreap_copyout(wo, p, pid, uid, why, status);
}
+ traced = ptrace_reparented(p);
/*
- * Try to move the task's state to DEAD
- * only one thread is allowed to do this:
+ * Move the task's state to DEAD/TRACE, only one thread can do this.
*/
- state = xchg(&p->exit_state, EXIT_DEAD);
- if (state != EXIT_ZOMBIE) {
- BUG_ON(state != EXIT_DEAD);
+ state = traced && thread_group_leader(p) ? EXIT_TRACE : EXIT_DEAD;
+ if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE)
return 0;
- }
-
- traced = ptrace_reparented(p);
/*
* It can be ptraced but not reparented, check
* thread_group_leader() to filter out sub-threads.
/*
* Now we are sure this task is interesting, and no other
- * thread can reap it because we set its state to EXIT_DEAD.
+ * thread can reap it because we its state == DEAD/TRACE.
*/
read_unlock(&tasklist_lock);
if (!retval)
retval = pid;
- if (traced) {
+ if (state == EXIT_TRACE) {
write_lock_irq(&tasklist_lock);
/* We dropped tasklist, ptracer could die and untrace */
ptrace_unlink(p);
- /*
- * If this is not a sub-thread, notify the parent.
- * If parent wants a zombie, don't release it now.
- */
- if (thread_group_leader(p) &&
- !do_notify_parent(p, p->exit_signal)) {
- p->exit_state = EXIT_ZOMBIE;
- p = NULL;
- }
+
+ /* If parent wants a zombie, don't release it now */
+ state = EXIT_ZOMBIE;
+ if (do_notify_parent(p, p->exit_signal))
+ state = EXIT_DEAD;
+ p->exit_state = state;
write_unlock_irq(&tasklist_lock);
}
- if (p != NULL)
+ if (state == EXIT_DEAD)
release_task(p);
return retval;
static int wait_consider_task(struct wait_opts *wo, int ptrace,
struct task_struct *p)
{
- int ret = eligible_child(wo, p);
+ int ret;
+
+ if (unlikely(p->exit_state == EXIT_DEAD))
+ return 0;
+
+ ret = eligible_child(wo, p);
if (!ret)
return ret;
return 0;
}
- /* dead body doesn't have much to contribute */
- if (unlikely(p->exit_state == EXIT_DEAD)) {
+ if (unlikely(p->exit_state == EXIT_TRACE)) {
/*
- * But do not ignore this task until the tracer does
- * wait_task_zombie()->do_notify_parent().
+ * ptrace == 0 means we are the natural parent. In this case
+ * we should clear notask_error, debugger will notify us.
*/
- if (likely(!ptrace) && unlikely(ptrace_reparented(p)))
+ if (likely(!ptrace))
wo->notask_error = 0;
return 0;
}
- /* slay zombie? */
- if (p->exit_state == EXIT_ZOMBIE) {
+ if (likely(!ptrace) && unlikely(p->ptrace)) {
/*
- * A zombie ptracee is only visible to its ptracer.
- * Notification and reaping will be cascaded to the real
- * parent when the ptracer detaches.
+ * If it is traced by its real parent's group, just pretend
+ * the caller is ptrace_do_wait() and reap this child if it
+ * is zombie.
+ *
+ * This also hides group stop state from real parent; otherwise
+ * a single stop can be reported twice as group and ptrace stop.
+ * If a ptracer wants to distinguish these two events for its
+ * own children it should create a separate process which takes
+ * the role of real parent.
*/
- if (likely(!ptrace) && unlikely(p->ptrace)) {
- /* it will become visible, clear notask_error */
- wo->notask_error = 0;
- return 0;
- }
+ if (!ptrace_reparented(p))
+ ptrace = 1;
+ }
+ /* slay zombie? */
+ if (p->exit_state == EXIT_ZOMBIE) {
/* we don't reap group leaders with subthreads */
- if (!delay_group_leader(p))
- return wait_task_zombie(wo, p);
+ if (!delay_group_leader(p)) {
+ /*
+ * A zombie ptracee is only visible to its ptracer.
+ * Notification and reaping will be cascaded to the
+ * real parent when the ptracer detaches.
+ */
+ if (unlikely(ptrace) || likely(!p->ptrace))
+ return wait_task_zombie(wo, p);
+ }
/*
* Allow access to stopped/continued state via zombie by
if (likely(!ptrace) || (wo->wo_flags & (WCONTINUED | WEXITED)))
wo->notask_error = 0;
} else {
- /*
- * If @p is ptraced by a task in its real parent's group,
- * hide group stop/continued state when looking at @p as
- * the real parent; otherwise, a single stop can be
- * reported twice as group and ptrace stops.
- *
- * If a ptracer wants to distinguish the two events for its
- * own children, it should create a separate process which
- * takes the role of real parent.
- */
- if (likely(!ptrace) && p->ptrace && !ptrace_reparented(p))
- return 0;
-
/*
* @p is alive and it's gonna stop, continue or exit, so
* there always is something to wait for.
git.openpandora.org / pandora-kernel.git / blobdiff