summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorEric W. Biederman <ebiederm@xmission.com>2006-12-21 21:28:40 -0700
committerChris Wright <chrisw@sous-sol.org>2007-02-05 08:31:40 -0800
commitb4e8b1a91dd54ad653036367a11ff8b7cf109534 (patch)
tree21868f8334f1befab719fea4261472bffe711f71
parentde18536d60a831433d75c7082a9a7f4724d1f96c (diff)
[PATCH] Fix reparenting to the same thread group. (take 2)
This patch fixes the case when we reparent to a different thread in the same thread group. This modifies the code so that we do not send signals and do not change the signal to send to SIGCHLD unless we have change the thread group of our parents. It also suppresses sending pdeath_sig in this cas as well since the result of geppid doesn't change. Thanks to Oleg for spotting my bug of only fixing this for non-ptraced tasks. This fixes the issues identified by Albert Cahalan in thread http://lkml.org/lkml/2006/12/21/22. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Mike Galbraith <efault@gmx.de> Cc: Albert Cahalan <acahalan@gmail.com> Cc: Andrew Morton <akpm@osdl.org> Cc: Roland McGrath <roland@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Coywolf Qi Hunt <qiyong@fc-cn.com> Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@osdl.org> [chrisw: fold in 241ceee0b442, Oleg's fix to restore user visible behaviour] Signed-off-by: Chris Wright <chrisw@sous-sol.org>
-rw-r--r--kernel/exit.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 06de6c4e8ca3..0e36258dd864 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -603,10 +603,6 @@ choose_new_parent(struct task_struct *p, struct task_struct *reaper)
static void
reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
{
- /* We don't want people slaying init. */
- if (p->exit_signal != -1)
- p->exit_signal = SIGCHLD;
-
if (p->pdeath_signal)
/* We already hold the tasklist_lock here. */
group_send_sig_info(p->pdeath_signal, SEND_SIG_NOINFO, p);
@@ -626,13 +622,7 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
p->parent = p->real_parent;
add_parent(p);
- /* If we'd notified the old parent about this child's death,
- * also notify the new parent.
- */
- if (p->exit_state == EXIT_ZOMBIE && p->exit_signal != -1 &&
- thread_group_empty(p))
- do_notify_parent(p, p->exit_signal);
- else if (p->state == TASK_TRACED) {
+ if (p->state == TASK_TRACED) {
/*
* If it was at a trace stop, turn it into
* a normal stop since it's no longer being
@@ -642,6 +632,23 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
}
}
+ /* If this is a threaded reparent there is no need to
+ * notify anyone anything has happened.
+ */
+ if (p->real_parent->group_leader == father->group_leader)
+ return;
+
+ /* We don't want people slaying init. */
+ if (p->exit_signal != -1)
+ p->exit_signal = SIGCHLD;
+
+ /* If we'd notified the old parent about this child's death,
+ * also notify the new parent.
+ */
+ if (!traced && p->exit_state == EXIT_ZOMBIE &&
+ p->exit_signal != -1 && thread_group_empty(p))
+ do_notify_parent(p, p->exit_signal);
+
/*
* process group orphan check
* Case ii: Our child is in a different pgrp