From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753362AbaKGUOi (ORCPT ); Fri, 7 Nov 2014 15:14:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45847 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753202AbaKGUOh (ORCPT ); Fri, 7 Nov 2014 15:14:37 -0500 Date: Fri, 7 Nov 2014 21:14:46 +0100 From: Oleg Nesterov To: Andrew Morton Cc: Aaron Tomlin , Alexey Dobriyan , "Eric W. Biederman" , Sterling Alexander , linux-kernel@vger.kernel.org Subject: [PATCH 1/4] proc: task_state: read cred->group_info outside of task_lock() Message-ID: <20141107201446.GA22233@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141107201424.GA22209@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 task_state() reads cred->group_info under task_lock() because a long ago it was task_struct->group_info and it was actually protected by task->alloc_lock. Today this task_unlock() after rcu_read_unlock() just adds the confusion, move task_unlock() up. Signed-off-by: Oleg Nesterov --- fs/proc/array.c | 3 +-- 1 files changed, 1 insertions(+), 2 deletions(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index cd3653e..b5810c2 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -201,11 +201,10 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, "FDSize:\t%d\n" "Groups:\t", fdt ? fdt->max_fds : 0); + task_unlock(p); rcu_read_unlock(); group_info = cred->group_info; - task_unlock(p); - for (g = 0; g < group_info->ngroups; g++) seq_printf(m, "%d ", from_kgid_munged(user_ns, GROUP_AT(group_info, g))); -- 1.5.5.1