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 9183FC4332F for ; Thu, 9 Sep 2021 12:14:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E2686113E for ; Thu, 9 Sep 2021 12:14:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350723AbhIIMOM (ORCPT ); Thu, 9 Sep 2021 08:14:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:47412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348649AbhIIMHo (ORCPT ); Thu, 9 Sep 2021 08:07:44 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 20C9D6187C; Thu, 9 Sep 2021 11:47:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631188070; bh=6dNN8OQPe/wsB34uoI/ICMKD2qSsK5yWqTj8ezysK4A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dvhvezXZHeA/O2LVaHLLUQPiUT4NjajO8ngtrwd2VheHH+NXfi0N+b+DjXErO/KTc 6TpyHcd+PM6SMQKLCVU7SN5bjXgrBa0bDqv5BQ5cCTiUMPc/zqCTMhw4JYDmB5V+EK 0v2sKbwC0r2Zs+jcCRPA81Bu8buiRfYaBwjC4P29DgHexW/aQBARPU6mISiIVN8Lc8 Ew7hNTS6mS5rO2bYvtekh/PBTisWYpTwECy7BEiunS4DqQfCUmRO5OwrJcPZXmeBBR eYDj4JE7zAqdpAQ29N8V6wRMPuGpV33+b3yP+/9w6NltOKVBwraguWC8STYKsVqlhx 3NHCdFK/oBxqg== 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 5.13 057/219] drm/bridge: nwl-dsi: Avoid potential multiplication overflow on 32-bit Date: Thu, 9 Sep 2021 07:43:53 -0400 Message-Id: <20210909114635.143983-57-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210909114635.143983-1-sashal@kernel.org> References: <20210909114635.143983-1-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