From 0a967a044a777e8b9c739120927114ddc0094298 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 2 Apr 2009 16:58:15 -0700 Subject: [PATCH] reparent_thread: don't call kill_orphaned_pgrp() if task_detached() If task_detached(p) == T, then either a) p is not the main thread, we will find the group leader on the ->children list. or b) p is the group leader but its ->exit_state = EXIT_DEAD. This can only happen when the last sub-thread has died, but in that case that thread has already called kill_orphaned_pgrp() from exit_notify(). In both cases kill_orphaned_pgrp() looks bogus. Move the task_detached() check up and simplify the code, this is also right from the "common sense" pov: we should do nothing with the detached childs, except move them to the new parent's ->children list. Signed-off-by: Oleg Nesterov Cc: Roland McGrath Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/exit.c b/kernel/exit.c index 576eae233b53..405e6877168b 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -818,6 +818,8 @@ static void reparent_thread(struct task_struct *p, struct task_struct *father) list_move_tail(&p->sibling, &p->real_parent->children); + if (task_detached(p)) + return; /* If this is a threaded reparent there is no need to * notify anyone anything has happened. */ @@ -825,15 +827,13 @@ static void reparent_thread(struct task_struct *p, struct task_struct *father) return; /* We don't want people slaying init. */ - if (!task_detached(p)) - p->exit_signal = SIGCHLD; + p->exit_signal = SIGCHLD; /* If we'd notified the old parent about this child's death, * also notify the new parent. */ if (!ptrace_reparented(p) && - p->exit_state == EXIT_ZOMBIE && - !task_detached(p) && thread_group_empty(p)) + p->exit_state == EXIT_ZOMBIE && thread_group_empty(p)) do_notify_parent(p, p->exit_signal); kill_orphaned_pgrp(p, father); -- 2.30.2