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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 06EF5C433C1 for ; Wed, 24 Mar 2021 12:19:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB4B7619CB for ; Wed, 24 Mar 2021 12:19:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232010AbhCXMSz (ORCPT ); Wed, 24 Mar 2021 08:18:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:34002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229716AbhCXMSi (ORCPT ); Wed, 24 Mar 2021 08:18:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BCDD361A05; Wed, 24 Mar 2021 12:18:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616588318; bh=NbapMJTLgnN/hTMuqni8rldYG3iXiZwynRdZVPVSR3g=; h=From:To:Cc:Subject:Date:From; b=gDP58QSwtXffFOGt/cM15NaJiFb9eUeJH6dcmR7F7nEnjkeJDCpSHwo+m2kfrg5XR bRWV03IrQhy6kV7czeIzP2wFQ03EL4GGIzo/wcnyQVA4sdMsC4T6duwBGIVKgfL8Wl t/lPPfviNpQGo0twQRrJwCKBC6PhHvNZ/Vl0vA1bTeWQo6FNvUypNqbFbJl9Tf3rWQ hqlw4dQiFpyEHKlR0meAzJNYZlcgZ+/2iitl6pPKGbYCOGYCxyWDOeHcJP9r+qggAV vK9CubHtwy6ORV+UigJlaj+A77+ZoePMDDXbyl3LoCPilo19lAZ2ed33xT+Z5dTofI jNe0YoloU30LQ== From: Arnd Bergmann To: Philipp Zabel , David Airlie , Daniel Vetter Cc: Arnd Bergmann , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , Marco Felsch , Laurent Pinchart , Joe Perches , Liu Ying , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] [v2] drm/imx: imx-ldb: fix out of bounds array access warning Date: Wed, 24 Mar 2021 13:17:59 +0100 Message-Id: <20210324121832.3714570-1-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann When CONFIG_OF is disabled, building with 'make W=1' produces warnings about out of bounds array access: drivers/gpu/drm/imx/imx-ldb.c: In function 'imx_ldb_set_clock.constprop': drivers/gpu/drm/imx/imx-ldb.c:186:8: error: array subscript -22 is below array bounds of 'struct clk *[4]' [-Werror=array-bounds] Add an error check before the index is used, which helps with the warning, as well as any possible other error condition that may be triggered at runtime. The warning could be fixed by adding a Kconfig depedency on CONFIG_OF, but Liu Ying points out that the driver may hit the out-of-bounds problem at runtime anyway. Signed-off-by: Arnd Bergmann --- v2: fix subject line expand patch description print mux number check upper bound as well --- drivers/gpu/drm/imx/imx-ldb.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c index dbfe39e2f7f6..40310327fa76 100644 --- a/drivers/gpu/drm/imx/imx-ldb.c +++ b/drivers/gpu/drm/imx/imx-ldb.c @@ -197,6 +197,12 @@ static void imx_ldb_encoder_enable(struct drm_encoder *encoder) int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN; int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder); + if (mux < 0 || mux >= ARRAY_SIZE(ldb->clk_sel)) { + dev_warn(ldb->dev, "%s: invalid mux %d\n", + __func__, ERR_PTR(mux)); + return; + } + drm_panel_prepare(imx_ldb_ch->panel); if (dual) { @@ -255,6 +261,12 @@ imx_ldb_encoder_atomic_mode_set(struct drm_encoder *encoder, int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder); u32 bus_format = imx_ldb_ch->bus_format; + if (mux < 0 || mux >= ARRAY_SIZE(ldb->clk_sel)) { + dev_warn(ldb->dev, "%s: invalid mux %d\n", + __func__, ERR_PTR(mux)); + return; + } + if (mode->clock > 170000) { dev_warn(ldb->dev, "%s: mode exceeds 170 MHz pixel clock\n", __func__); -- 2.29.2