From patchwork Fri Mar 6 17:40:41 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arend van Spriel X-Patchwork-Id: 5956901 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: X-Original-To: patchwork-linux-wireless@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 33420BF440 for ; Fri, 6 Mar 2015 17:41:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 67CD7202B8 for ; Fri, 6 Mar 2015 17:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CD4A20351 for ; Fri, 6 Mar 2015 17:41:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128AbbCFRkz (ORCPT ); Fri, 6 Mar 2015 12:40:55 -0500 Received: from mail-gw3-out.broadcom.com ([216.31.210.64]:24792 "EHLO mail-gw3-out.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754002AbbCFRkt (ORCPT ); Fri, 6 Mar 2015 12:40:49 -0500 X-IronPort-AV: E=Sophos;i="5.11,354,1422950400"; d="scan'208";a="58653936" Received: from irvexchcas07.broadcom.com (HELO IRVEXCHCAS07.corp.ad.broadcom.com) ([10.9.208.55]) by mail-gw3-out.broadcom.com with ESMTP; 06 Mar 2015 09:40:46 -0800 Received: from IRVEXCHSMTP2.corp.ad.broadcom.com (10.9.207.52) by IRVEXCHCAS07.corp.ad.broadcom.com (10.9.208.55) with Microsoft SMTP Server (TLS) id 14.3.174.1; Fri, 6 Mar 2015 09:40:46 -0800 Received: from mail-sj1-12.sj.broadcom.com (10.10.10.20) by IRVEXCHSMTP2.corp.ad.broadcom.com (10.9.207.52) with Microsoft SMTP Server id 14.3.174.1; Fri, 6 Mar 2015 09:40:46 -0800 Received: from lb-bun-235.bun.broadcom.com (lb-bun-235.bun.broadcom.com [10.176.8.235]) by mail-sj1-12.sj.broadcom.com (Postfix) with ESMTP id 8C5FA27A88; Fri, 6 Mar 2015 09:40:46 -0800 (PST) Received: from arend by lb-bun-235.bun.broadcom.com with local (Exim 4.82) (envelope-from ) id 1YTwEv-00059Q-Ns; Fri, 06 Mar 2015 18:40:45 +0100 From: Arend van Spriel To: Kalle Valo CC: linux-wireless , Hante Meuleman , Arend van Spriel Subject: [PATCH 4/5] brcmfmac: Fix race condition in msgbuf ioctl processing. Date: Fri, 6 Mar 2015 18:40:41 +0100 Message-ID: <1425663642-19725-5-git-send-email-arend@broadcom.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1425663642-19725-1-git-send-email-arend@broadcom.com> References: <1425663642-19725-1-git-send-email-arend@broadcom.com> MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Hante Meuleman Msgbuf is using a wait_event_timeout to wait for the response on an ioctl. The wakeup routine uses waitqueue_active to see if wait_event_timeout has been called. There is a chance that the response arrives before wait_event_timeout is called, this will result in situation that wait_event_timeout never gets woken again and assumed result will be a timeout. This patch removes that errornous situation by always setting the ctl_completed var before checking for queue active. Reviewed-by: Arend Van Spriel Reviewed-by: Pieter-Paul Giesberts Signed-off-by: Hante Meuleman Signed-off-by: Arend van Spriel --- drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c b/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c index 6262612..4ec9811 100644 --- a/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/msgbuf.c @@ -481,10 +481,9 @@ static int brcmf_msgbuf_ioctl_resp_wait(struct brcmf_msgbuf *msgbuf) static void brcmf_msgbuf_ioctl_resp_wake(struct brcmf_msgbuf *msgbuf) { - if (waitqueue_active(&msgbuf->ioctl_resp_wait)) { - msgbuf->ctl_completed = true; + msgbuf->ctl_completed = true; + if (waitqueue_active(&msgbuf->ioctl_resp_wait)) wake_up(&msgbuf->ioctl_resp_wait); - } }