Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933449Ab3DMP6B (ORCPT ); Sat, 13 Apr 2013 11:58:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44575 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932604Ab3DMP57 (ORCPT ); Sat, 13 Apr 2013 11:57:59 -0400 Date: Sat, 13 Apr 2013 17:55:21 +0200 From: Oleg Nesterov To: Andrey Vagin , "Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, Andrew Morton , Al Viro , David Howells Subject: [PATCH 1/1] move exit_task_namespaces() outside of exit_notify() Message-ID: <20130413155521.GB6533@redhat.com> References: <1365794853-23912-1-git-send-email-avagin@openvz.org> <20130413142246.GA864@redhat.com> <20130413155457.GA6533@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130413155457.GA6533@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1600 Lines: 44 exit_notify() does exit_task_namespaces() after forget_original_parent(). This was needed to ensure that ->nsproxy can't be cleared prematurely, an exiting child we are going to reparent can do do_notify_parent() and use the parent's (ours) pid_ns. However, after 32084504 "pidns: use task_active_pid_ns in do_notify_parent" ->nsproxy != NULL is no longer needed, we rely on task_active_pid_ns(). Move exit_task_namespaces() from exit_notify() to do_exit(), after exit_fs() and before exit_task_work(). This solves the problem reported by Andrey, free_ipc_ns()->shm_destroy() does fput() which needs task_work_add(). And this allows us do simplify exit_notify(), we can avoid unlock/lock(tasklist) and we can change ->exit_state instead of PF_EXITING in forget_original_parent(). Reported-by: Andrey Vagin Signed-off-by: Oleg Nesterov --- x/kernel/exit.c +++ x/kernel/exit.c @@ -649,7 +649,6 @@ static void exit_notify(struct task_stru * jobs, send them a SIGHUP and then a SIGCONT. (POSIX 3.2.2.2) */ forget_original_parent(tsk); - exit_task_namespaces(tsk); write_lock_irq(&tasklist_lock); if (group_dead) @@ -795,6 +794,7 @@ void do_exit(long code) exit_shm(tsk); exit_files(tsk); exit_fs(tsk); + exit_task_namespaces(tsk); exit_task_work(tsk); check_stack_usage(); exit_thread(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/