[PATCH 6/8] kill task_detached()

[Oleg Nesterov <oleg@redhat.com>]

Upadate the last user of task_detached(), wait_task_zombie(), to
use thread_group_leader() and kill task_detached().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---

 include/linux/sched.h |    5 -----
 kernel/exit.c         |    5 ++---
 2 files changed, 2 insertions(+), 8 deletions(-)

--- ptrace/include/linux/sched.h~6_kill_task_detached	2011-06-22 22:47:12.000000000 +0200
+++ ptrace/include/linux/sched.h	2011-06-22 22:47:13.000000000 +0200
@@ -2319,11 +2319,6 @@ static inline int thread_group_empty(str
 #define delay_group_leader(p) \
 		(thread_group_leader(p) && !thread_group_empty(p))
 
-static inline int task_detached(struct task_struct *p)
-{
-	return p->exit_signal == -1;
-}
-
 /*
  * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring
  * subscriptions and synchronises with wait4().  Also used in procfs.  Also
--- ptrace/kernel/exit.c~6_kill_task_detached	2011-06-22 22:47:12.000000000 +0200
+++ ptrace/kernel/exit.c	2011-06-22 22:47:13.000000000 +0200
@@ -189,7 +189,6 @@ repeat:
 	zap_leader = 0;
 	leader = p->group_leader;
 	if (leader != p && thread_group_empty(leader) && leader->exit_state == EXIT_ZOMBIE) {
-		BUG_ON(task_detached(leader));
 		/*
 		 * If we were the last child thread and the leader has
 		 * exited already, and the leader's parent ignores SIGCHLD,
@@ -1228,9 +1227,9 @@ static int wait_task_zombie(struct wait_
 	traced = ptrace_reparented(p);
 	/*
 	 * It can be ptraced but not reparented, check
-	 * !task_detached() to filter out sub-threads.
+	 * thread_group_leader() to filter out sub-threads.
 	 */
-	if (likely(!traced) && likely(!task_detached(p))) {
+	if (likely(!traced) && thread_group_leader(p)) {
 		struct signal_struct *psig;
 		struct signal_struct *sig;
 		unsigned long maxrss;