From patchwork Fri Feb 20 18:12:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabian Frederick X-Patchwork-Id: 442102 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 20287140161 for ; Sat, 21 Feb 2015 05:13:56 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932471AbbBTSNL (ORCPT ); Fri, 20 Feb 2015 13:13:11 -0500 Received: from mailrelay107.isp.belgacom.be ([195.238.20.134]:8656 "EHLO mailrelay107.isp.belgacom.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932186AbbBTSNJ (ORCPT ); Fri, 20 Feb 2015 13:13:09 -0500 X-Belgacom-Dynamic: yes X-Cloudmark-SP-Filtered: true X-Cloudmark-SP-Result: v=1.1 cv=pojTLeLEEG+IB9MeyQ9xnWKWJHiyH+4Hnj5iAYu/pCk= c=1 sm=2 a=JfrnYn6hAAAA:8 a=LuN3jVANQ06kIUEDBOgA:9 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2DuCwAReOdU/zwEtFtbgwaxSgUBdpdNAoEYRAEBAQEBAXyEEAEFJy8jEFE5HhmIMwHCKJJPAQEBByKGBIl5BxaEFQWZEYpsiEUig289MYJDAQEB Received: from 60.4-180-91.adsl-dyn.isp.belgacom.be (HELO localhost.localdomain) ([91.180.4.60]) by relay.skynet.be with ESMTP; 20 Feb 2015 19:13:10 +0100 From: Fabian Frederick To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Peter Zijlstra , Greg Kroah-Hartman , Fabian Frederick , "Jan \"Yenya\" Kasprzak" , netdev@vger.kernel.org Subject: [PATCH 6/7 linux-next] wan: cosa: replace current->state by set_current_state() Date: Fri, 20 Feb 2015 19:12:56 +0100 Message-Id: <1424455977-21903-6-git-send-email-fabf@skynet.be> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1424455977-21903-1-git-send-email-fabf@skynet.be> References: <1424455977-21903-1-git-send-email-fabf@skynet.be> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Use helper functions to access current->state. Direct assignments are prone to races and therefore buggy. current->state = TASK_RUNNING is replaced by __set_current_state() Thanks to Peter Zijlstra for the exact definition of the problem. Suggested-By: Peter Zijlstra Signed-off-by: Fabian Frederick Acked-By: Jan "Yenya" Kasprzak --- drivers/net/wan/cosa.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/wan/cosa.c b/drivers/net/wan/cosa.c index 83c39e2..88d121d 100644 --- a/drivers/net/wan/cosa.c +++ b/drivers/net/wan/cosa.c @@ -806,21 +806,21 @@ static ssize_t cosa_read(struct file *file, spin_lock_irqsave(&cosa->lock, flags); add_wait_queue(&chan->rxwaitq, &wait); while (!chan->rx_status) { - current->state = TASK_INTERRUPTIBLE; + set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irqrestore(&cosa->lock, flags); schedule(); spin_lock_irqsave(&cosa->lock, flags); if (signal_pending(current) && chan->rx_status == 0) { chan->rx_status = 1; remove_wait_queue(&chan->rxwaitq, &wait); - current->state = TASK_RUNNING; + __set_current_state(TASK_RUNNING); spin_unlock_irqrestore(&cosa->lock, flags); mutex_unlock(&chan->rlock); return -ERESTARTSYS; } } remove_wait_queue(&chan->rxwaitq, &wait); - current->state = TASK_RUNNING; + __set_current_state(TASK_RUNNING); kbuf = chan->rxdata; count = chan->rxsize; spin_unlock_irqrestore(&cosa->lock, flags); @@ -890,14 +890,14 @@ static ssize_t cosa_write(struct file *file, spin_lock_irqsave(&cosa->lock, flags); add_wait_queue(&chan->txwaitq, &wait); while (!chan->tx_status) { - current->state = TASK_INTERRUPTIBLE; + set_current_state(TASK_INTERRUPTIBLE); spin_unlock_irqrestore(&cosa->lock, flags); schedule(); spin_lock_irqsave(&cosa->lock, flags); if (signal_pending(current) && chan->tx_status == 0) { chan->tx_status = 1; remove_wait_queue(&chan->txwaitq, &wait); - current->state = TASK_RUNNING; + __set_current_state(TASK_RUNNING); chan->tx_status = 1; spin_unlock_irqrestore(&cosa->lock, flags); up(&chan->wsem); @@ -905,7 +905,7 @@ static ssize_t cosa_write(struct file *file, } } remove_wait_queue(&chan->txwaitq, &wait); - current->state = TASK_RUNNING; + __set_current_state(TASK_RUNNING); up(&chan->wsem); spin_unlock_irqrestore(&cosa->lock, flags); kfree(kbuf);