From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764333AbXHXI6M (ORCPT ); Fri, 24 Aug 2007 04:58:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751739AbXHXI6B (ORCPT ); Fri, 24 Aug 2007 04:58:01 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:7572 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751352AbXHXI6A (ORCPT ); Fri, 24 Aug 2007 04:58:00 -0400 Message-ID: <46CE9B23.9000500@openvz.org> Date: Fri, 24 Aug 2007 12:47:31 +0400 From: Pavel Emelyanov User-Agent: Thunderbird 2.0.0.6 (X11/20070728) MIME-Version: 1.0 To: Andrew Morton CC: Linux Containers , Linux Kernel Mailing List , Oleg Nesterov , Sukadev Bhattiprolu , Alexey Dobriyan Subject: [PATCH] Fix the sys_setpgrp() to work between namespaces Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The check if (task_pgrp_nr(p) != pgid) is almost always true, because pgid is a "virtual" pid and it is most often much smaller than the "real" pgrp id of any task (because pids are generated sequentially most of the time). This leads to the task's pgrp is always reset, even if it is not needed. Signed-off-by: Pavel Emelyanov --- kernel/sys.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-) diff --git a/kernel/sys.c b/kernel/sys.c index c7c4fa4..c827186 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -918,6 +918,7 @@ asmlinkage long sys_setpgid(pid_t pid, p struct task_struct *p; struct task_struct *group_leader = current->group_leader; int err = -EINVAL; + struct pid_namespace *ns; if (!pid) pid = task_pid_vnr(group_leader); @@ -929,10 +930,12 @@ asmlinkage long sys_setpgid(pid_t pid, p /* From this point forward we keep holding onto the tasklist lock * so that our parent does not change from under us. -DaveM */ + ns = current->nsproxy->pid_ns; + write_lock_irq(&tasklist_lock); err = -ESRCH; - p = find_task_by_pid_ns(pid, current->nsproxy->pid_ns); + p = find_task_by_pid_ns(pid, ns); if (!p) goto out; @@ -958,10 +961,9 @@ asmlinkage long sys_setpgid(pid_t pid, p goto out; if (pgid != pid) { - struct task_struct *g = - find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, - current->nsproxy->pid_ns); + struct task_struct *g; + g = find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, ns); if (!g || task_session(g) != task_session(group_leader)) goto out; } @@ -970,7 +972,7 @@ asmlinkage long sys_setpgid(pid_t pid, p if (err) goto out; - if (task_pgrp_nr(p) != pgid) { + if (task_pgrp_nr_ns(p, ns) != pgid) { struct pid *pid; detach_pid(p, PIDTYPE_PGID);