From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752788AbeBFQrx (ORCPT ); Tue, 6 Feb 2018 11:47:53 -0500 Received: from gateway23.websitewelcome.com ([192.185.50.108]:27487 "EHLO gateway23.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752742AbeBFQrj (ORCPT ); Tue, 6 Feb 2018 11:47:39 -0500 Date: Tue, 6 Feb 2018 10:47:37 -0600 From: "Gustavo A. R. Silva" To: Ramesh Shanmugasundaram , Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH v3 3/8] i2c: max2175: use 64-bit arithmetic instead of 32-bit Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.175.4.238 X-Source-L: No X-Exim-ID: 1ej6PC-000lD9-G1 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.175.4.238]:46642 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 25 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add suffix LL to constant 2 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type s64 (64 bits, signed). The expression 2 * (clock_rate - abs_nco_freq) is currently being evaluated using 32-bit arithmetic. Addresses-Coverity-ID: 1446589 ("Unintentional integer overflow") Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - Update subject and changelog to better reflect the proposed code changes. - Add suffix LL to constant instead of casting a variable. Changes in v3: - Mention the specific Coverity report in the commit message. drivers/media/i2c/max2175.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/i2c/max2175.c b/drivers/media/i2c/max2175.c index 2f1966b..87cba15 100644 --- a/drivers/media/i2c/max2175.c +++ b/drivers/media/i2c/max2175.c @@ -643,7 +643,7 @@ static int max2175_set_nco_freq(struct max2175 *ctx, s32 nco_freq) if (abs_nco_freq < clock_rate / 2) { nco_val_desired = 2 * nco_freq; } else { - nco_val_desired = 2 * (clock_rate - abs_nco_freq); + nco_val_desired = 2LL * (clock_rate - abs_nco_freq); if (nco_freq < 0) nco_val_desired = -nco_val_desired; } -- 2.7.4