From patchwork Tue Mar 13 14:48:12 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: 10281569 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 EC83A602C2 for ; Wed, 14 Mar 2018 08:03:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 329F927FE4 for ; Wed, 14 Mar 2018 08:03:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 273F728749; Wed, 14 Mar 2018 08:03:04 +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 A2FDF27FE4 for ; Wed, 14 Mar 2018 08:03:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D236B6E688; Wed, 14 Mar 2018 08:02:12 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org X-Greylist: delayed 1385 seconds by postgrey-1.36 at gabe; Tue, 13 Mar 2018 15:11:21 UTC Received: from gateway31.websitewelcome.com (gateway31.websitewelcome.com [192.185.144.95]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6B2726E56F for ; Tue, 13 Mar 2018 15:11:21 +0000 (UTC) Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway31.websitewelcome.com (Postfix) with ESMTP id EE9EE814C for ; Tue, 13 Mar 2018 09:48:15 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id vlDreDuSBz11gvlDreqbDq; Tue, 13 Mar 2018 09:48:15 -0500 Received: from [189.175.117.58] (port=55832 helo=embeddedgus) by gator4166.hostgator.com with esmtpa (Exim 4.89_1) (envelope-from ) id 1evlDr-0016AN-Bw; Tue, 13 Mar 2018 09:48:15 -0500 Date: Tue, 13 Mar 2018 09:48:12 -0500 From: "Gustavo A. R. Silva" To: Ben Skeggs , David Airlie Subject: [PATCH] drm/nouveau/secboot: remove VLA usage Message-ID: <20180313144812.GA30043@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: 1evlDr-0016AN-Bw X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedgus) [189.175.117.58]:55832 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 7 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: nouveau@lists.freedesktop.org, 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 directly use macro NVKM_MSGQUEUE_CMDLINE_SIZE instead of local variable cmdline_size. Also, remove cmdline_size as it is not actually useful anymore. 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/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c b/drivers/gpu/drm/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c index 6f10b09..2da147b 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/secboot/ls_ucode_msgqueue.c @@ -80,12 +80,12 @@ acr_ls_msgqueue_post_run(struct nvkm_msgqueue *queue, struct nvkm_falcon *falcon, u32 addr_args) { struct nvkm_device *device = falcon->owner->device; - u32 cmdline_size = NVKM_MSGQUEUE_CMDLINE_SIZE; - u8 buf[cmdline_size]; + u8 buf[NVKM_MSGQUEUE_CMDLINE_SIZE]; - memset(buf, 0, cmdline_size); + memset(buf, 0, NVKM_MSGQUEUE_CMDLINE_SIZE); nvkm_msgqueue_write_cmdline(queue, buf); - nvkm_falcon_load_dmem(falcon, buf, addr_args, cmdline_size, 0); + nvkm_falcon_load_dmem(falcon, buf, addr_args, + NVKM_MSGQUEUE_CMDLINE_SIZE, 0); /* rearm the queue so it will wait for the init message */ nvkm_msgqueue_reinit(queue);