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 B5338C3F2D2 for ; Thu, 5 Mar 2020 17:16:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83B98217F4 for ; Thu, 5 Mar 2020 17:16:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428565; bh=+P8sB4H5yi+g9UNuOWK2JO1vju8lSiUvedGXcJ/u/nk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sDtV3/lhFFoBGfk5qC2ABgZ183Wgno3qgCxTD+lVTo/VUCwZOJcrVjok9LOZ7dIOn dMo0fY6Fp6GN/8cRUgXTBhnk7Azd8mARVp1cfixHCMigmLB0n9VNVN4QD/tQb5Nhed U3bmPDDpw+ULif3ej1r4TnObDbrIPw7adRfXqk7g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728360AbgCERQE (ORCPT ); Thu, 5 Mar 2020 12:16:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:42672 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728255AbgCERPt (ORCPT ); Thu, 5 Mar 2020 12:15:49 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 1743D20848; Thu, 5 Mar 2020 17:15:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583428548; bh=+P8sB4H5yi+g9UNuOWK2JO1vju8lSiUvedGXcJ/u/nk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H/9wTZ8vG+O8Yey7uCX/WltamwmOcrG1F7UJkvtSsgJ/nO2GuS2ah8P9tJpMVsNbu rzfZI9J1oJYQTm0/rzR2BlpWj3GbgwAB59Tzs/mUC7gf8uvJyyvGYI9rBTOZy1QaE8 xpBZOEin9QVvkJ2GNvC62BxvN/zWE4VFBx62PsaQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Gustavo A. R. Silva" , David Laight , Thor Thayer , Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 06/19] i2c: altera: Fix potential integer overflow Date: Thu, 5 Mar 2020 12:15:27 -0500 Message-Id: <20200305171540.30250-6-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200305171540.30250-1-sashal@kernel.org> References: <20200305171540.30250-1-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: "Gustavo A. R. Silva" [ Upstream commit 54498e8070e19e74498a72c7331348143e7e1f8c ] 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: Sasha Levin --- drivers/i2c/busses/i2c-altera.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c index f5e1941e65b5a..a1cdcfc74acf6 100644 --- 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_i2c_dev *idev) /* 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); -- 2.20.1