From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15B35C7618F for ; Mon, 15 Jul 2019 14:30:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF70220868 for ; Mon, 15 Jul 2019 14:30:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563201058; bh=eQJs6jpX4HDyLOG8yKg/tO63IJGZS3h9Y5ylv26XbxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=h7gT2rByHOkPJYa9ZYFqvSXM49076Xzmb1hkd0IQJ/UYKdF4XeMqEklRQ69UwbfKX ucM++Cp7vAGY/qraVqssSb3xtYeTV6Dac+JZNwWjn3QkF/rr/eWqyhap3obpYtKb4t powes9rqS+4fxA6NEWLTPOeVb2dIAVDM/APrtZhA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391767AbfGOOa5 (ORCPT ); Mon, 15 Jul 2019 10:30:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:44170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732124AbfGOOaz (ORCPT ); Mon, 15 Jul 2019 10:30:55 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B0195206B8; Mon, 15 Jul 2019 14:30:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563201054; bh=eQJs6jpX4HDyLOG8yKg/tO63IJGZS3h9Y5ylv26XbxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pag1FwrTjLt5+Y3otpDznAoxfdzFqEyYnTl2aCcUKZrv2UIsGlS6Oy+DYdyWD/f0W kQKSZLJWePiJXIcsSmjFta8kSwngzgxSOLZ0epqaC9Oh0zBzkq4W52Er8ZXF0Oa4Bq pwELhyZpShlD55nyUIb8bToyKWVaWZ8EoMZILNWU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Robert Hancock , Russell King , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 038/105] net: sfp: add mutex to prevent concurrent state checks Date: Mon, 15 Jul 2019 10:27:32 -0400 Message-Id: <20190715142839.9896-38-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715142839.9896-1-sashal@kernel.org> References: <20190715142839.9896-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Robert Hancock [ Upstream commit 2158e856f56bb762ef90f3ec244d41a519826f75 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 2dcb25aa0452..9cef89fe410d 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -115,10 +115,11 @@ struct sfp { struct gpio_desc *gpio[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; @@ -738,6 +739,7 @@ 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; @@ -763,6 +765,7 @@ 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) @@ -793,6 +796,7 @@ 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); -- 2.20.1