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From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Michal Hocko <mhocko@suse.cz>,
	Pavel Emelyanov <xemul@parallels.com>,
	Sergey Dyasly <dserrg@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 1/4] de_thread: use change_pid() rather than detach_pid/attach_pid
Date: Sun, 9 Jun 2013 19:00:23 +0200	[thread overview]
Message-ID: <20130609170023.GA5233@redhat.com> (raw)
In-Reply-To: <20130609170007.GA5215@redhat.com>

de_thread() can use change_pid() instead of detach + attach.
This looks better and this ensures that, say, next_thread()
can never see a task with ->pid == NULL.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 fs/exec.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 6430195..00eaba7 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -945,9 +945,8 @@ static int de_thread(struct task_struct *tsk)
 		 * Note: The old leader also uses this pid until release_task
 		 *       is called.  Odd but simple and correct.
 		 */
-		detach_pid(tsk, PIDTYPE_PID);
 		tsk->pid = leader->pid;
-		attach_pid(tsk, PIDTYPE_PID,  task_pid(leader));
+		change_pid(tsk, PIDTYPE_PID, task_pid(leader));
 		transfer_pid(leader, tsk, PIDTYPE_PGID);
 		transfer_pid(leader, tsk, PIDTYPE_SID);
 
-- 
1.5.5.1


  reply	other threads:[~2013-06-09 17:04 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-09 17:00 [PATCH v2 0/4] copy_process/attach_pid minor fix + cleanups Oleg Nesterov
2013-06-09 17:00 ` Oleg Nesterov [this message]
2013-06-10  4:07   ` [PATCH 1/4] de_thread: use change_pid() rather than detach_pid/attach_pid Eric W. Biederman
2013-06-09 17:00 ` [PATCH 2/4] copy_process: unify CLONE_THREAD-or-thread_group_leader code Oleg Nesterov
2013-06-09 17:00 ` [PATCH 3/4] copy_process: don't add the uninitialized child to thread/task/pid lists Oleg Nesterov
2013-06-09 17:00 ` [PATCH 4/4] copy_process: consolidate the lockless CLONE_THREAD checks Oleg Nesterov

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