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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E160C54EAA for ; Mon, 30 Jan 2023 14:21:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237607AbjA3OV6 (ORCPT ); Mon, 30 Jan 2023 09:21:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237513AbjA3OVg (ORCPT ); Mon, 30 Jan 2023 09:21:36 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FD7341B58 for ; Mon, 30 Jan 2023 06:20:30 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0DC9461163 for ; Mon, 30 Jan 2023 14:19:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D71AC433D2; Mon, 30 Jan 2023 14:19:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675088365; bh=1gryz0cv82+0ccF08W16vekhIdzYwFssQ/bTF71gZiY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V6EsxLNfU5JH8PUzMTD/zwCx1CZYhqQtM2QJLamAtzOfacx4L3sahuzNUTPjMM0RM LqM5vAizlSTa4A8Tc9F2y4XCkTal+Mh7hG2NuipeFf0LE8xlLD7x6CcvPgwrTh8lXI jrWDrAiNvGxxl77dn6+iIAfodHjeFrHQui6L4Q5M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lareine Khawaly , Hanna Hawa , Andy Shevchenko , Jarkko Nikula , Wolfram Sang , Sasha Levin Subject: [PATCH 5.15 169/204] i2c: designware: use casting of u64 in clock multiplication to avoid overflow Date: Mon, 30 Jan 2023 14:52:14 +0100 Message-Id: <20230130134324.008833552@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230130134316.327556078@linuxfoundation.org> References: <20230130134316.327556078@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lareine Khawaly [ Upstream commit c8c37bc514514999e62a17e95160ed9ebf75ca8d ] In functions i2c_dw_scl_lcnt() and i2c_dw_scl_hcnt() may have overflow by depending on the values of the given parameters including the ic_clk. For example in our use case where ic_clk is larger than one million, multiplication of ic_clk * 4700 will result in 32 bit overflow. Add cast of u64 to the calculation to avoid multiplication overflow, and use the corresponding define for divide. Fixes: 2373f6b9744d ("i2c-designware: split of i2c-designware.c into core and bus specific parts") Signed-off-by: Lareine Khawaly Signed-off-by: Hanna Hawa Reviewed-by: Andy Shevchenko Acked-by: Jarkko Nikula Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-designware-common.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index a1100e37626e..4af65f101dac 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -351,7 +351,8 @@ u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset) * * If your hardware is free from tHD;STA issue, try this one. */ - return DIV_ROUND_CLOSEST(ic_clk * tSYMBOL, MICRO) - 8 + offset; + return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * tSYMBOL, MICRO) - + 8 + offset; else /* * Conditional expression: @@ -367,7 +368,8 @@ u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset) * The reason why we need to take into account "tf" here, * is the same as described in i2c_dw_scl_lcnt(). */ - return DIV_ROUND_CLOSEST(ic_clk * (tSYMBOL + tf), MICRO) - 3 + offset; + return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tSYMBOL + tf), MICRO) - + 3 + offset; } u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) @@ -383,7 +385,8 @@ u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) * account the fall time of SCL signal (tf). Default tf value * should be 0.3 us, for safety. */ - return DIV_ROUND_CLOSEST(ic_clk * (tLOW + tf), MICRO) - 1 + offset; + return DIV_ROUND_CLOSEST_ULL((u64)ic_clk * (tLOW + tf), MICRO) - + 1 + offset; } int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev) -- 2.39.0