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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 7674AC18E7A for ; Tue, 10 Mar 2020 13:07:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3CBB424691 for ; Tue, 10 Mar 2020 13:07:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845646; bh=j/cTGtyx0i2W8prlaQJxrHhlNQJqNPuJz2rSwBTjyBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=I1/YIR+R8lnOi4GPQUUG86tFeWq9YjG19DQxXZ6P1PcIhq1M3//8gSZt479l1nl4c dow+SBtVdFcm/ZPILmMyI55xNG60zldzFsWP7ERCqRfqyHlRCy/M4zf/1g0JX2qyE8 7Qb4whxllW9NXFFGYHERfFVfbaKdKSIwNYVa51fo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730969AbgCJNHZ (ORCPT ); Tue, 10 Mar 2020 09:07:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:53110 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728988AbgCJNHW (ORCPT ); Tue, 10 Mar 2020 09:07:22 -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 A0A3220873; Tue, 10 Mar 2020 13:07:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583845641; bh=j/cTGtyx0i2W8prlaQJxrHhlNQJqNPuJz2rSwBTjyBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EsMTXbkUhqJNU3ubbqn60Nhf+WAlAZUHudrn3XVZMD1GnHm9qbSP7OfApenDE50eM Mgh2wuzIKLLtGglD7lzeLODzmP82C/VUnhJe+7epgRpHfP+r0Dc0U+3+hSt4/gEpJN /O+l/zDD+SI0de845HTDGbGhqq1tFf6pQLM2Mr0s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Laight , "Gustavo A. R. Silva" , Thor Thayer , Wolfram Sang Subject: [PATCH 4.14 046/126] i2c: altera: Fix potential integer overflow Date: Tue, 10 Mar 2020 13:41:07 +0100 Message-Id: <20200310124207.229610173@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200310124203.704193207@linuxfoundation.org> References: <20200310124203.704193207@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: Gustavo A. R. Silva commit 54498e8070e19e74498a72c7331348143e7e1f8c upstream. Factor out 100 from the equation and do 32-bit arithmetic (3 * clk_mhz / 10) instead of 64-bit. Notice that clk_mhz is MHz, so the multiplication will never wrap 32 bits and there is no need for div_u64(). Addresses-Coverity: 1458369 ("Unintentional integer overflow") Fixes: 0560ad576268 ("i2c: altera: Add Altera I2C Controller driver") Suggested-by: David Laight Signed-off-by: Gustavo A. R. Silva Reviewed-by: Thor Thayer Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-altera.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/i2c/busses/i2c-altera.c +++ b/drivers/i2c/busses/i2c-altera.c @@ -182,7 +182,7 @@ static void altr_i2c_init(struct altr_i2 /* SCL Low Time */ writel(t_low, idev->base + ALTR_I2C_SCL_LOW); /* SDA Hold Time, 300ns */ - writel(div_u64(300 * clk_mhz, 1000), idev->base + ALTR_I2C_SDA_HOLD); + writel(3 * clk_mhz / 10, idev->base + ALTR_I2C_SDA_HOLD); /* Mask all master interrupt bits */ altr_i2c_int_enable(idev, ALTR_I2C_ALL_IRQ, false);