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=-19.4 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,URIBL_BLOCKED,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 A84CEC3F2C2 for ; Thu, 9 Sep 2021 12:39:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9208F6113A for ; Thu, 9 Sep 2021 12:39:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354977AbhIIMkJ (ORCPT ); Thu, 9 Sep 2021 08:40:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:34526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351018AbhIIM2Q (ORCPT ); Thu, 9 Sep 2021 08:28:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8817561B20; Thu, 9 Sep 2021 11:52:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188335; bh=6dNN8OQPe/wsB34uoI/ICMKD2qSsK5yWqTj8ezysK4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pc3Qv4SGdOsz4zMrw/bcxpyZJC1eldDJPqtIK9m1gxgxP6u9/+u12h81kwWKJvBWm yVu5KWvc6ZDSCpK8h2aDs6nHAaNBBA43/wWHqpKPe8qFtRMXbWFY1zF4UXmMeqOMO0 y7D9BgzuCTm4wWP8DYtbvUvQVyh9Cvb6XgYBUh1WL4w9vV6R/yjhyoBKyf+YKgMh1q pjXFGHKRNnlw+lzP5heLncLXkqgP/DW1pQXvdfi6BmHwwWbPV+nbkKwz7e7Dnw4Pwx quAXRoJOKc0YAd5N/ztx+ygHQXSRIKhAuJbglk2oQnw2n8H5z7aCCNHu/jRf19TK34 n6Rh/Y7EE6eOA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Geert Uytterhoeven , Fabio Estevam , Laurent Pinchart , Sam Ravnborg , Sasha Levin , dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.10 044/176] drm/bridge: nwl-dsi: Avoid potential multiplication overflow on 32-bit Date: Thu, 9 Sep 2021 07:49:06 -0400 Message-Id: <20210909115118.146181-44-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909115118.146181-1-sashal@kernel.org> References: <20210909115118.146181-1-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: Geert Uytterhoeven [ Upstream commit 47956bc86ee4e8530cac386a04f62a6095f7afbe ] As nwl_dsi.lanes is u32, and NSEC_PER_SEC is 1000000000L, the second multiplication in dsi->lanes * 8 * NSEC_PER_SEC will overflow on a 32-bit platform. Fix this by making the constant unsigned long long, forcing 64-bit arithmetic. As iMX8 is arm64, this driver is currently used on 64-bit platforms only, where long is 64-bit, so this cannot happen. But the issue will start to happen when the driver is reused for a 32-bit SoC (e.g. i.MX7ULP), or when code is copied for a new driver. Signed-off-by: Geert Uytterhoeven Reviewed-by: Fabio Estevam Reviewed-by: Laurent Pinchart Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/ebb82941a86b4e35c4fcfb1ef5a5cfad7c1fceab.1626255956.git.geert+renesas@glider.be Signed-off-by: Sasha Levin --- drivers/gpu/drm/bridge/nwl-dsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c index c65ca860712d..6cac2e58cd15 100644 --- a/drivers/gpu/drm/bridge/nwl-dsi.c +++ b/drivers/gpu/drm/bridge/nwl-dsi.c @@ -196,7 +196,7 @@ static u32 ps2bc(struct nwl_dsi *dsi, unsigned long long ps) u32 bpp = mipi_dsi_pixel_format_to_bpp(dsi->format); return DIV64_U64_ROUND_UP(ps * dsi->mode.clock * bpp, - dsi->lanes * 8 * NSEC_PER_SEC); + dsi->lanes * 8ULL * NSEC_PER_SEC); } /* -- 2.30.2