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 25AF5C433E0 for ; Wed, 24 Mar 2021 16:48:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E80E0619E3 for ; Wed, 24 Mar 2021 16:48:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236624AbhCXQsL (ORCPT ); Wed, 24 Mar 2021 12:48:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:43124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237003AbhCXQr4 (ORCPT ); Wed, 24 Mar 2021 12:47:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 05AC361A06; Wed, 24 Mar 2021 16:47:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1616604475; bh=p+1TIRUmePIQc6WtQPg9mzBzgEJQ9OP7+R0w8iP3j40=; h=From:To:Cc:Subject:Date:From; b=QkfJpyXzcvwWQuYP12k3YP8sS65dUJpTatoatVEjc43JkFpqNlUPVsjzAWuKoY5I1 UxhZ0t3EY/Rbro2FE9s1zYHRnW2j85Sosjb7WwGb1Y4aVor5j1JFsaMEHE8WC/PCxX vBW+zFJd++kSDgxH9mTh4ye9GM4THg70dyEfo5M9GOc6Gd87o9aKYwuS6GnQAY1iIn DP6X5xi4D+OBiWLQqIl2IrgMn/7I08Rqw7kVDZc+lg+wgvVTuHDtX8Xdy6+DdBWbzp tqM2UL+3JcpY0uU8VW5gbLn62vAqS61OF7kSTn1CLGc3KeyrFQCFLQDVVLKU7HvgOF DC+FNlt5ne5og== 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 , Sam Ravnborg , Liu Ying , Joe Perches , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] [v3] drm/imx: imx-ldb: fix out of bounds array access warning Date: Wed, 24 Mar 2021 17:47:41 +0100 Message-Id: <20210324164750.3833773-1-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 --- v3: fix build regression from v2 v2: fix subject line expand patch description print mux number check upper bound as well --- drivers/gpu/drm/imx/imx-ldb.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/imx/imx-ldb.c b/drivers/gpu/drm/imx/imx-ldb.c index dbfe39e2f7f6..565482e2b816 100644 --- a/drivers/gpu/drm/imx/imx-ldb.c +++ b/drivers/gpu/drm/imx/imx-ldb.c @@ -197,6 +197,11 @@ 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__, mux); + return; + } + drm_panel_prepare(imx_ldb_ch->panel); if (dual) { @@ -255,6 +260,11 @@ 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__, mux); + return; + } + if (mode->clock > 170000) { dev_warn(ldb->dev, "%s: mode exceeds 170 MHz pixel clock\n", __func__); -- 2.29.2