From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754638Ab2KGKCx (ORCPT ); Wed, 7 Nov 2012 05:02:53 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:20428 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751573Ab2KGKCu (ORCPT ); Wed, 7 Nov 2012 05:02:50 -0500 Subject: [PATCH 4/4] ipc: add more comments to message copying related code To: akpm@linux-foundation.org From: Stanislav Kinsbursky Cc: ebiederm@xmission.com, devel@openvz.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, jmorris@namei.org Date: Wed, 07 Nov 2012 13:05:10 +0300 Message-ID: <20121107100510.22846.706.stgit@localhost.localdomain> In-Reply-To: <20121107100317.22846.94715.stgit@localhost.localdomain> References: <20121107100317.22846.94715.stgit@localhost.localdomain> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Stanislav Kinsbursky --- ipc/msg.c | 8 ++++++++ 1 files changed, 8 insertions(+), 0 deletions(-) diff --git a/ipc/msg.c b/ipc/msg.c index 5e317fe..4a4725c 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -770,6 +770,10 @@ static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) } #ifdef CONFIG_CHECKPOINT_RESTORE +/* + * This function creates new kernel message structure, large enough to store + * bufsz message bytes. + */ static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz, int msgflg, long *msgtyp, unsigned long *copy_number) @@ -881,6 +885,10 @@ long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, msg = ERR_PTR(-E2BIG); goto out_unlock; } + /* + * If we are copying, then do not unlink message and do + * not update queue parameters. + */ if (msgflg & MSG_COPY) goto out_unlock; list_del(&msg->m_list);