From patchwork Tue Mar 13 14:31:51 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 10281563 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2988760211 for ; Wed, 14 Mar 2018 08:01:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1BE56286B4 for ; Wed, 14 Mar 2018 08:01:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1046228749; Wed, 14 Mar 2018 08:01:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 670F5286B4 for ; Wed, 14 Mar 2018 08:01:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 397C16E51F; Wed, 14 Mar 2018 08:01:48 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org X-Greylist: delayed 1282 seconds by postgrey-1.36 at gabe; Tue, 13 Mar 2018 14:53:17 UTC Received: from gateway22.websitewelcome.com (gateway22.websitewelcome.com [192.185.47.179]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2DFB86E55A for ; Tue, 13 Mar 2018 14:53:17 +0000 (UTC) Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway22.websitewelcome.com (Postfix) with ESMTP id B905658CAA for ; Tue, 13 Mar 2018 09:31:53 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id vky1e54P4E0sxvky1e4Okv; Tue, 13 Mar 2018 09:31:53 -0500 Received: from [189.175.117.58] (port=55664 helo=embeddedgus) by gator4166.hostgator.com with esmtpa (Exim 4.89_1) (envelope-from ) id 1evky1-000mkS-0B; Tue, 13 Mar 2018 09:31:53 -0500 Date: Tue, 13 Mar 2018 09:31:51 -0500 From: "Gustavo A. R. Silva" To: Eric Anholt , David Airlie Subject: [PATCH] drm/vc4_validate: Remove VLA usage Message-ID: <20180313143151.GA27486@embeddedgus> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - lists.freedesktop.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.175.117.58 X-Source-L: No X-Exim-ID: 1evky1-000mkS-0B X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.175.117.58]:55664 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 3 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-Mailman-Approved-At: Wed, 14 Mar 2018 08:01:47 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP In preparation to enabling -Wvla, remove VLA. In this particular case use macro ARRAY_SIZE so the length of array _bo_ can be computed at preprocessing time. The use of stack Variable Length Arrays needs to be avoided, as they can be a vector for stack exhaustion, which can be both a runtime bug or a security flaw. Also, in general, as code evolves it is easy to lose track of how big a VLA can get. Thus, we can end up having runtime failures that are hard to debug. Also, fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Gustavo A. R. Silva --- drivers/gpu/drm/vc4/vc4_validate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_validate.c b/drivers/gpu/drm/vc4/vc4_validate.c index 2db485a..eec76af 100644 --- a/drivers/gpu/drm/vc4/vc4_validate.c +++ b/drivers/gpu/drm/vc4/vc4_validate.c @@ -753,7 +753,7 @@ validate_gl_shader_rec(struct drm_device *dev, 28, /* cs */ }; uint32_t shader_reloc_count = ARRAY_SIZE(shader_reloc_offsets); - struct drm_gem_cma_object *bo[shader_reloc_count + 8]; + struct drm_gem_cma_object *bo[ARRAY_SIZE(shader_reloc_offsets) + 8]; uint32_t nr_attributes, nr_relocs, packet_size; int i;