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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 7B1CEC433E2 for ; Mon, 20 Jul 2020 16:10:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FE85207DD for ; Mon, 20 Jul 2020 16:10:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261423; bh=SctYfMR3QP81Kg16x2UXd6MhWrHdYmtqjLLE50S52Qg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=owuGxKbpJ538iymhyWnRE0eR9djJ6G8F64f+pX5Sdj5xPP8D/tlQJv5OTNanxntYy NDkDFKMIhUROVMErhB9OPF5v8LOljZXqcVVTdMjHe+lWV9p9H2csZ/GhAoAckrzTtQ CsDvzGV1Dvy5Msf5XaoNSXQ8vLPcjXqpIE0JpbF0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733241AbgGTQKV (ORCPT ); Mon, 20 Jul 2020 12:10:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:48758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731840AbgGTQKS (ORCPT ); Mon, 20 Jul 2020 12:10:18 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F168322CBB; Mon, 20 Jul 2020 16:10:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595261417; bh=SctYfMR3QP81Kg16x2UXd6MhWrHdYmtqjLLE50S52Qg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eazYyY2TkPI8QVLzNoo+0T/TQ4LjNUEQk/8Wqh2NIKh30gHbvmsJy3sijGYrSrxmP FxpIW8C3qRj0Yq5OksbUsaO56k2Vfx2pQDuNquR7c9YTPan3Vg4/8HOk0T9qMAhNUQ 5sAHIkc+zeLIzfTGsXW9QsY1msUkxjNKayIetpgw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Syed Nayyar Waris , Jonathan Cameron , Sasha Levin Subject: [PATCH 5.7 078/244] counter: 104-quad-8: Add lock guards - differential encoder Date: Mon, 20 Jul 2020 17:35:49 +0200 Message-Id: <20200720152829.552887673@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152825.863040590@linuxfoundation.org> References: <20200720152825.863040590@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Syed Nayyar Waris [ Upstream commit 708d98932893cea609386cefdfd190f757f5a61c ] Add lock protection from race conditions to 104-quad-8 counter driver for differential encoder status code changes. Mutex lock calls used for protection. Signed-off-by: Syed Nayyar Waris Fixes: 954ab5cc5f3e ("counter: 104-quad-8: Support Differential Encoder Cable Status") Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/counter/104-quad-8.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index aa13708c2bc30..9364dc188f8ff 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -1274,18 +1274,26 @@ static ssize_t quad8_signal_cable_fault_read(struct counter_device *counter, struct counter_signal *signal, void *private, char *buf) { - const struct quad8_iio *const priv = counter->priv; + struct quad8_iio *const priv = counter->priv; const size_t channel_id = signal->id / 2; - const bool disabled = !(priv->cable_fault_enable & BIT(channel_id)); + bool disabled; unsigned int status; unsigned int fault; - if (disabled) + mutex_lock(&priv->lock); + + disabled = !(priv->cable_fault_enable & BIT(channel_id)); + + if (disabled) { + mutex_unlock(&priv->lock); return -EINVAL; + } /* Logic 0 = cable fault */ status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); + mutex_unlock(&priv->lock); + /* Mask respective channel and invert logic */ fault = !(status & BIT(channel_id)); @@ -1317,6 +1325,8 @@ static ssize_t quad8_signal_cable_fault_enable_write( if (ret) return ret; + mutex_lock(&priv->lock); + if (enable) priv->cable_fault_enable |= BIT(channel_id); else @@ -1327,6 +1337,8 @@ static ssize_t quad8_signal_cable_fault_enable_write( outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); + mutex_unlock(&priv->lock); + return len; } -- 2.25.1