From patchwork Fri Jun 7 16:42:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Hancock X-Patchwork-Id: 1112081 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=sedsystems.ca Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45L7cW3kNWz9s7h for ; Sat, 8 Jun 2019 02:42:51 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731039AbfFGQmu (ORCPT ); Fri, 7 Jun 2019 12:42:50 -0400 Received: from sed198n136.SEDSystems.ca ([198.169.180.136]:5375 "EHLO sed198n136.sedsystems.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730958AbfFGQmt (ORCPT ); Fri, 7 Jun 2019 12:42:49 -0400 Received: from barney.sedsystems.ca (barney [198.169.180.121]) by sed198n136.sedsystems.ca with ESMTP id x57Gghij029774 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 7 Jun 2019 10:42:43 -0600 (CST) Received: from SED.RFC1918.192.168.sedsystems.ca (eng1n65.eng.sedsystems.ca [172.21.1.65]) by barney.sedsystems.ca (8.14.7/8.14.4) with ESMTP id x57GgeOm030818 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 7 Jun 2019 10:42:43 -0600 From: Robert Hancock To: netdev@vger.kernel.org Cc: linux@armlinux.org.uk, andrew@lunn.ch, f.fainelli@gmail.com, hkallweit1@gmail.com, Robert Hancock Subject: [PATCH net-next 2/2] net: sfp: add mutex to prevent concurrent state checks Date: Fri, 7 Jun 2019 10:42:36 -0600 Message-Id: <1559925756-29593-3-git-send-email-hancock@sedsystems.ca> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1559925756-29593-1-git-send-email-hancock@sedsystems.ca> References: <1559925756-29593-1-git-send-email-hancock@sedsystems.ca> X-Scanned-By: MIMEDefang 2.64 on 198.169.180.136 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org sfp_check_state can potentially be called by both a threaded IRQ handler and delayed work. If it is concurrently called, it could result in incorrect state management. Add a st_mutex to protect the state - this lock gets taken outside of code that checks and handle state changes, and the existing sm_mutex nests inside of it. Suggested-by: Russell King Signed-off-by: Robert Hancock --- drivers/net/phy/sfp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index 01af080..edd2de5 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -188,10 +188,11 @@ struct sfp { int gpio_irq[GPIO_MAX]; bool attached; + struct mutex st_mutex; /* Protects state */ unsigned int state; struct delayed_work poll; struct delayed_work timeout; - struct mutex sm_mutex; + struct mutex sm_mutex; /* Protects state machine */ unsigned char sm_mod_state; unsigned char sm_dev_state; unsigned short sm_state; @@ -1705,6 +1706,7 @@ static void sfp_check_state(struct sfp *sfp) { unsigned int state, i, changed; + mutex_lock(&sfp->st_mutex); state = sfp_get_state(sfp); changed = state ^ sfp->state; changed &= SFP_F_PRESENT | SFP_F_LOS | SFP_F_TX_FAULT; @@ -1730,6 +1732,7 @@ static void sfp_check_state(struct sfp *sfp) sfp_sm_event(sfp, state & SFP_F_LOS ? SFP_E_LOS_HIGH : SFP_E_LOS_LOW); rtnl_unlock(); + mutex_unlock(&sfp->st_mutex); } static irqreturn_t sfp_irq(int irq, void *data) @@ -1760,6 +1763,7 @@ static struct sfp *sfp_alloc(struct device *dev) sfp->dev = dev; mutex_init(&sfp->sm_mutex); + mutex_init(&sfp->st_mutex); INIT_DELAYED_WORK(&sfp->poll, sfp_poll); INIT_DELAYED_WORK(&sfp->timeout, sfp_timeout);