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=-20.5 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=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 2B9E9C64E7C for ; Sun, 29 Nov 2020 20:10:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D327F20756 for ; Sun, 29 Nov 2020 20:10:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="HaBHq0rm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728189AbgK2UKN (ORCPT ); Sun, 29 Nov 2020 15:10:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:49054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727695AbgK2UKM (ORCPT ); Sun, 29 Nov 2020 15:10:12 -0500 Received: from threadripper.lan (HSI-KBW-46-223-126-90.hsi.kabel-badenwuerttemberg.de [46.223.126.90]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 685F320756; Sun, 29 Nov 2020 20:09:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1606680572; bh=rQ5NWEEEPU4g45U80zBfT28KT/fxWWNh4bB2Arjzahk=; h=From:To:Cc:Subject:Date:From; b=HaBHq0rmQ3UUakU8auzk6mvEnyoOY5gHkt7DdwdL+XdzKV4NuuddNb01IJWJSZQ7J RF7AkL64t8au1LQVxNjL5/nfsTs4eLh3WIfmKxRJZ66nNDHIxVPhiIDTA8E3g446/P TJjkOnrB9/JVN2YyxvcrYkxABSRqQaYcsRJbBcKY= From: Arnd Bergmann To: Anitha Chrisanthus , Edmund Dea , David Airlie , Daniel Vetter , Sam Ravnborg Cc: Arnd Bergmann , kernel test robot , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH] drm/kmb: fix array bounds warning Date: Sun, 29 Nov 2020 21:09:08 +0100 Message-Id: <20201129200927.1854104-1-arnd@kernel.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann gcc warns about an out-of-bounds access when the using nonzero values for 'plane_id' on kmb->plane_status: drivers/gpu/drm/kmb/kmb_plane.c: In function 'kmb_plane_atomic_disable': drivers/gpu/drm/kmb/kmb_plane.c:128:20: warning: array subscript 3 is above array bounds of 'struct layer_status[1]' [-Warray-bounds] 128 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE; | ~~~~~~~~~~~~~~~~~^~~~~~~~~~ drivers/gpu/drm/kmb/kmb_plane.c:125:20: warning: array subscript 2 is above array bounds of 'struct layer_status[1]' [-Warray-bounds] 125 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL1_ENABLE; | ~~~~~~~~~~~~~~~~~^~~~~~~~~~ drivers/gpu/drm/kmb/kmb_plane.c:122:20: warning: array subscript 1 is above array bounds of 'struct layer_status[1]' [-Warray-bounds] 122 | kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL2_ENABLE; Having the array truncated to one entry seems intentional, so add a range check before indexing it to make it clearer what is going on and shut up the warning. I received the warning from the kernel test robot after a private patch that turns on Warray-bounds unconditionally. Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display") Reported-by: kernel test robot Signed-off-by: Arnd Bergmann --- drivers/gpu/drm/kmb/kmb_plane.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/kmb/kmb_plane.c b/drivers/gpu/drm/kmb/kmb_plane.c index 8448d1edb553..be8eea3830c1 100644 --- a/drivers/gpu/drm/kmb/kmb_plane.c +++ b/drivers/gpu/drm/kmb/kmb_plane.c @@ -114,6 +114,9 @@ static void kmb_plane_atomic_disable(struct drm_plane *plane, kmb = to_kmb(plane->dev); + if (WARN_ON(plane_id >= KMB_MAX_PLANES)) + return; + switch (plane_id) { case LAYER_0: kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL1_ENABLE; -- 2.27.0