From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 13 Sep 2001 13:09:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 13 Sep 2001 13:08:52 -0400 Received: from e31.co.us.ibm.com ([32.97.110.129]:20668 "EHLO e31.bld.us.ibm.com") by vger.kernel.org with ESMTP id ; Thu, 13 Sep 2001 13:08:44 -0400 Message-ID: <3BA111FD.499BBF1D@us.ibm.com> Date: Thu, 13 Sep 2001 10:07:25 -1000 From: Mingming cao Organization: Linux Technology Center X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.4.2-2 i686) X-Accept-Language: en MIME-Version: 1.0 To: torvalds@transmeta.com, alan@lxorguk.ukuu.org.uk CC: linux-kernel@vger.kernel.org, manfreds@colorfullife.com Subject: [PATCH]Fix bug in msgsnd Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello linus & Alan, This patch fixes a bug in msgsnd. If a message is sent via pipelined_send(), the q_lrpid field of the associated message queue (last pid receive) is not updated correctly. The existing code (apparently by mistake) updates the lspid field instead. The second problem is that, for the pipelinesend case, q_lstime(last msgsnd time) is set AFTER q_lrtime(last msgrcv time), yielding a negative time delta. This patch is against kernel 2.4.9 and has been tested. Please apply. Please CC your feedback to me also, thanks. -- Mingming Cao IBM Linux Technology Center diff -urN -X dontdiff linux/ipc/msg.c linux-tk/ipc/msg.c --- linux/ipc/msg.c Tue Sep 11 16:21:42 2001 +++ linux-tk/ipc/msg.c Tue Sep 11 16:21:31 2001 @@ -613,7 +613,7 @@ wake_up_process(msr->r_tsk); } else { msr->r_msg = msg; - msq->q_lspid = msr->r_tsk->pid; + msq->q_lrpid = msr->r_tsk->pid; msq->q_rtime = CURRENT_TIME; wake_up_process(msr->r_tsk); return 1; @@ -683,6 +683,9 @@ goto retry; } + msq->q_lspid = current->pid; + msq->q_stime = CURRENT_TIME; + if(!pipelined_send(msq,msg)) { /* noone is waiting for this message, enqueue it */ list_add_tail(&msg->m_list,&msq->q_messages); @@ -694,8 +697,6 @@ err = 0; msg = NULL; - msq->q_lspid = current->pid; - msq->q_stime = CURRENT_TIME; out_unlock_free: msg_unlock(msqid);