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=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 0A6BDC433F4 for ; Mon, 29 Mar 2021 22:27:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDBDF619E6 for ; Mon, 29 Mar 2021 22:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232720AbhC2W1B (ORCPT ); Mon, 29 Mar 2021 18:27:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:46968 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232259AbhC2WWx (ORCPT ); Mon, 29 Mar 2021 18:22:53 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3055F61996; Mon, 29 Mar 2021 22:22:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617056572; bh=vWRBsgeifkSEGdDN43XjQ99C3pOTI2n8xztY6JaE9is=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H7iP2TrKDQbh0LZjojiZvWU9uyxNcABR/k9TBZUi5BG669HEkNloppFAzRVgYqCvK 3QvqGsE1hANe3fq7rh70simzfZXwO2p/dExCwQ9vdIjU17Cyo0zu9Cwd7jQa2fT43o wtxiTBwmjDqSBrDlTajG55QJ+6ZfhaKlqhwzKvUNamDRJBNOt4zKg4GIuy6lD5YIuI HZkJpPJH0MZnjZvQSiZoW9CGIH3e0aRk2EvGG0t5yUsTy2HSacRUeX6ascPHuadv34 Pgs0hpCaMAZJBs7NWpVPwADbtAIpeTjEnBVlmwU3sGSbSjbN5N3qmmbDywN+0hohQp rH2qduxDZce4w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yangbo Lu , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.10 25/33] ptp_qoriq: fix overflow in ptp_qoriq_adjfine() u64 calcalation Date: Mon, 29 Mar 2021 18:22:13 -0400 Message-Id: <20210329222222.2382987-25-sashal@kernel.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210329222222.2382987-1-sashal@kernel.org> References: <20210329222222.2382987-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yangbo Lu [ Upstream commit f51d7bf1dbe5522c51c93fe8faa5f4abbdf339cd ] Current calculation for diff of TMR_ADD register value may have 64-bit overflow in this code line, when long type scaled_ppm is large. adj *= scaled_ppm; This patch is to resolve it by using mul_u64_u64_div_u64(). Signed-off-by: Yangbo Lu Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/ptp/ptp_qoriq.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/ptp/ptp_qoriq.c b/drivers/ptp/ptp_qoriq.c index beb5f74944cd..08f4cf0ad9e3 100644 --- a/drivers/ptp/ptp_qoriq.c +++ b/drivers/ptp/ptp_qoriq.c @@ -189,15 +189,16 @@ int ptp_qoriq_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) tmr_add = ptp_qoriq->tmr_add; adj = tmr_add; - /* calculate diff as adj*(scaled_ppm/65536)/1000000 - * and round() to the nearest integer + /* + * Calculate diff and round() to the nearest integer + * + * diff = adj * (ppb / 1000000000) + * = adj * scaled_ppm / 65536000000 */ - adj *= scaled_ppm; - diff = div_u64(adj, 8000000); - diff = (diff >> 13) + ((diff >> 12) & 1); + diff = mul_u64_u64_div_u64(adj, scaled_ppm, 32768000000); + diff = DIV64_U64_ROUND_UP(diff, 2); tmr_add = neg_adj ? tmr_add - diff : tmr_add + diff; - ptp_qoriq->write(®s->ctrl_regs->tmr_add, tmr_add); return 0; -- 2.30.1